WO2015146618A1 - Laser light intensity adjustment device - Google Patents
Laser light intensity adjustment device Download PDFInfo
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- WO2015146618A1 WO2015146618A1 PCT/JP2015/057417 JP2015057417W WO2015146618A1 WO 2015146618 A1 WO2015146618 A1 WO 2015146618A1 JP 2015057417 W JP2015057417 W JP 2015057417W WO 2015146618 A1 WO2015146618 A1 WO 2015146618A1
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- light
- unit
- light intensity
- laser
- liquid crystal
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- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B27/00—Optical systems or apparatus not provided for by any of the groups G02B1/00 - G02B26/00, G02B30/00
- G02B27/01—Head-up displays
- G02B27/0101—Head-up displays characterised by optical features
-
- G—PHYSICS
- G02—OPTICS
- G02F—OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
- G02F1/00—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
- G02F1/01—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour
- G02F1/13—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour based on liquid crystals, e.g. single liquid crystal display cells
-
- G—PHYSICS
- G02—OPTICS
- G02F—OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
- G02F1/00—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
- G02F1/01—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour
- G02F1/13—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour based on liquid crystals, e.g. single liquid crystal display cells
- G02F1/133—Constructional arrangements; Operation of liquid crystal cells; Circuit arrangements
-
- G—PHYSICS
- G02—OPTICS
- G02F—OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
- G02F1/00—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
- G02F1/01—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour
- G02F1/13—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour based on liquid crystals, e.g. single liquid crystal display cells
- G02F1/133—Constructional arrangements; Operation of liquid crystal cells; Circuit arrangements
- G02F1/13306—Circuit arrangements or driving methods for the control of single liquid crystal cells
- G02F1/13318—Circuits comprising a photodetector
-
- G—PHYSICS
- G02—OPTICS
- G02F—OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
- G02F1/00—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
- G02F1/01—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour
- G02F1/13—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour based on liquid crystals, e.g. single liquid crystal display cells
- G02F1/133—Constructional arrangements; Operation of liquid crystal cells; Circuit arrangements
- G02F1/1333—Constructional arrangements; Manufacturing methods
- G02F1/1335—Structural association of cells with optical devices, e.g. polarisers or reflectors
- G02F1/1336—Illuminating devices
- G02F1/133621—Illuminating devices providing coloured light
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- G—PHYSICS
- G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
- G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
- G09G3/00—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes
- G09G3/001—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes using specific devices not provided for in groups G09G3/02 - G09G3/36, e.g. using an intermediate record carrier such as a film slide; Projection systems; Display of non-alphanumerical information, solely or in combination with alphanumerical information, e.g. digital display on projected diapositive as background
- G09G3/002—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes using specific devices not provided for in groups G09G3/02 - G09G3/36, e.g. using an intermediate record carrier such as a film slide; Projection systems; Display of non-alphanumerical information, solely or in combination with alphanumerical information, e.g. digital display on projected diapositive as background to project the image of a two-dimensional display, such as an array of light emitting or modulating elements or a CRT
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- G—PHYSICS
- G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
- G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
- G09G3/00—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes
- G09G3/20—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters
- G09G3/34—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters by control of light from an independent source
- G09G3/36—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters by control of light from an independent source using liquid crystals
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
- H04N9/00—Details of colour television systems
- H04N9/12—Picture reproducers
- H04N9/31—Projection devices for colour picture display, e.g. using electronic spatial light modulators [ESLM]
- H04N9/3129—Projection devices for colour picture display, e.g. using electronic spatial light modulators [ESLM] scanning a light beam on the display screen
-
- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B27/00—Optical systems or apparatus not provided for by any of the groups G02B1/00 - G02B26/00, G02B30/00
- G02B27/01—Head-up displays
- G02B27/0101—Head-up displays characterised by optical features
- G02B2027/0112—Head-up displays characterised by optical features comprising device for genereting colour display
-
- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B27/00—Optical systems or apparatus not provided for by any of the groups G02B1/00 - G02B26/00, G02B30/00
- G02B27/01—Head-up displays
- G02B27/0101—Head-up displays characterised by optical features
- G02B2027/0118—Head-up displays characterised by optical features comprising devices for improving the contrast of the display / brillance control visibility
-
- G—PHYSICS
- G02—OPTICS
- G02F—OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
- G02F2203/00—Function characteristic
- G02F2203/34—Colour display without the use of colour mosaic filters
-
- G—PHYSICS
- G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
- G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
- G09G2320/00—Control of display operating conditions
- G09G2320/04—Maintaining the quality of display appearance
- G09G2320/041—Temperature compensation
-
- G—PHYSICS
- G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
- G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
- G09G2380/00—Specific applications
- G09G2380/10—Automotive applications
Definitions
- the present invention relates to a laser beam intensity adjusting device.
- a laser light intensity adjusting device that drives a laser light source is disclosed in Patent Document 1.
- the apparatus disclosed in Patent Document 1 has a configuration in which a liquid crystal cell and a polarizing plate are arranged between a laser light source and a scanning unit that scans the laser light to generate a display image.
- This apparatus adjusts the transmittance of the laser light transmitted through the liquid crystal cell and the polarizing plate by driving and controlling the liquid crystal cell. This makes it possible to generate a display image with low-intensity light, which is difficult only by controlling the light source.
- the transmittance of the liquid crystal cell is temperature dependent. For this reason, the configuration of the apparatus disclosed in Patent Document 1 has a problem in that a deviation occurs between the target laser light intensity and the actual intensity.
- this type of laser light intensity adjusting device is incorporated into an in-vehicle display device, for example, this problem becomes significant because the range of the atmospheric temperature becomes wide.
- the present invention has been made in view of the above circumstances, and an object thereof is to provide a laser light intensity adjusting device capable of stably adjusting a low-intensity laser beam even in a wide temperature range.
- a laser beam intensity adjusting device is A light source that emits laser light; A scanning unit that scans laser light emitted from the light source to generate a display image; A transmitted light adjusting unit that is located on an optical path from the light source to the scanning unit and transmits laser light emitted from the light source with a predetermined transmittance, and includes a liquid crystal cell and a polarizing plate.
- a temperature detector for detecting the temperature of the liquid crystal cell
- a control unit for driving the liquid crystal cell to control the transmittance of the transmitted light adjusting unit
- the control unit controls the transmittance of the transmitted light adjustment unit by correcting the variation of the transmittance due to the temperature change of the liquid crystal cell based on the temperature detected by the temperature detection unit, and reaches the scanning unit Adjust the light intensity of the laser light, It is characterized by that.
- the laser light intensity adjusting device according to the present embodiment is provided in the display device 1 shown in FIGS.
- the display device 1 is arranged on a dashboard of the vehicle 2 and is configured as a head-up display device that emits light representing a predetermined display image M (hereinafter, display light K) toward the windshield 3.
- the display device 1 causes the user 4 who is a driver of the vehicle 2 to visually recognize the display image M as a virtual image V by the display light K reflected by the windshield 3.
- the display image M is an image for notifying information about the vehicle 2 (hereinafter, vehicle information), for example.
- the display device 1 includes a synthetic laser light generation unit 10, a transmitted light adjustment unit 20, a temperature detection unit 30, a scanning unit 40, a transmission screen 50, a light intensity detection unit 60, A reflection unit 70, a housing 80, and an external light intensity detection unit 90 are provided.
- the synthetic laser beam generator 10 generates a synthetic laser beam C and emits it toward the scanning unit 40.
- the synthetic laser light generation unit 10 includes a laser light emission unit 11, a condensing unit 12, and a multiplexing unit 13.
- the laser beam emitting unit 11 includes a laser diode (LD) 11r that emits red laser beam R, an LD 11g that emits green laser beam G, and an LD 11b that emits blue laser beam B.
- LD laser diode
- Each of the LDs 11r, 11g, and 11b emits light at a predetermined light intensity and timing by a driving current supplied from an LD driving unit 100 described later.
- the condensing unit 12 condenses the laser beams R, G, and B emitted from the LD 11 to form convergent light.
- the condensing unit 12 includes condensing lenses 12r, 12g, and 12b corresponding to the LDs 11r, 11g, and 11b, respectively.
- the condenser lens 12r is located on the optical path of the laser light R emitted from the LD 11r. The same applies to the correspondence between the condenser lenses 12g and 12b and the LDs 11g and 11b.
- the multiplexing unit 13 combines the laser beams R, G, and B emitted from the LD 11 and reached via the light collecting unit 12 to generate a combined laser beam C.
- the multiplexing unit 13 includes a reflecting unit 13r made of a plane mirror or the like, a multiplexing unit 13g and a multiplexing unit 13b each made of a dichroic mirror that reflects light of a specific wavelength but transmits light of other wavelengths, It is composed of
- the reflection unit 13r reflects the incident laser light R toward the multiplexing unit 13g.
- the multiplexing unit 13g transmits the laser beam R from the reflection unit 13r as it is, and reflects the incident laser beam G toward the multiplexing unit 13b.
- the laser beam obtained by combining the laser beams R and G is emitted from the combining unit 13g toward the combining unit 13b.
- the multiplexing unit 13 b transmits the laser beam from the multiplexing unit 13 g as it is and reflects the incident laser beam B toward the scanning unit 40. In this way, the combined laser beam C obtained by combining the laser beams R, G, and B is emitted from the combining unit 13 b toward the scanning unit 40.
- the transmitted light adjusting unit 20 is located between the condensing unit 12 and the multiplexing unit 13 and transmits each laser beam R, G, B emitted from the LD 11 with a predetermined transmittance.
- the transmitted light adjusting unit 20 includes a liquid crystal cell 21 and a polarizing plate 22.
- the liquid crystal cell 21 has a pair of transparent substrates and a liquid crystal layer sealed between the substrates.
- Transparent electrodes are formed of ITO (Indium ⁇ Tin Oxide) or the like on the liquid crystal layer side of each transparent substrate of the liquid crystal cell 21.
- the liquid crystal cell 21 includes a red liquid crystal cell 21r into which the laser light R is incident, a green liquid crystal cell 21g into which the laser G is incident, and a blue color into which the laser light B is incident.
- Liquid crystal cell 21b A driving voltage is independently applied to the liquid crystal cells 21r, 21g, and 21b via the liquid crystal driving unit 200 under the control of the control unit 300 described later.
- the liquid crystal cells 21r, 21g, and 21b may be configured by providing a transparent electrode capable of applying a driving voltage for each cell on a pair of transparent substrates shared by the cells, or separate liquid crystal cells. It may be configured as.
- the liquid crystal cell 21 according to the present embodiment is a VA (Vertical Alignment) type.
- the polarizing plate 22 is disposed on the optical path of the laser beams R, G, and B transmitted through the liquid crystal cell 21.
- the polarizing plate 22 includes a wire grid polarizing plate, an iodine-based or pigment-based polarizing plate, a glass polarizer, and the like.
- the polarizing plate 22 may be an absorption type or a reflection type. As shown in FIGS. 4 (a) and 4 (b), the polarizing plate 22 has a transmission axis 22a, and transmits light having a polarization angle parallel to the transmission axis 22a out of the incident light, and other polarization angles. Does not transmit light.
- Each of the LDs 11r, 11g, and 11b is disposed so that the polarization angle of the emitted light is orthogonal to the transmission axis 22a of the polarizing plate 22.
- the direction of the transmission axis 22a of the polarizing plate 22 is determined in consideration of the polarization dependency of the reflectance of the windshield 3.
- FIG. 4A is a diagram illustrating a case where the laser beams R, G, and B do not pass through the transmitted light adjustment unit 20, and FIG. 4B illustrates that the laser beams R, G, and B are transmitted light adjustment unit 20.
- FIG. 4A a driving voltage is independently applied to each of the liquid crystal cells 21r, 21g, and 21b.
- the liquid crystal cells 21r, 21g, and 21b are common. It is assumed that an off voltage and an on voltage are applied.
- the off voltage is set to a value lower than the threshold voltage at which the liquid crystal molecules of the liquid crystal cell 21 start to fall. Therefore, the liquid crystal molecules remain vertically aligned even when an off voltage is applied to the liquid crystal cell 21. In this case, even if the laser beams R, G, and B are transmitted through the liquid crystal cell 21, the polarization angle hardly changes. Therefore, the light does not pass through the polarizing plate 22 having the transmission axis 22a perpendicular to the polarization angles of the laser beams R, G, and B (see FIG. 4A).
- the polarization angle of the laser light can be controlled by controlling the magnitude of the voltage applied to the liquid crystal cell 21. It can be arbitrarily controlled in the range of 0 ° to 90 °, and the transmittance of the laser beams R, G, and B can be controlled. That is, by controlling the voltage applied to each of the liquid crystal cells 21r, 21g, and 21b, the transmittance of the laser beams R, G, and B that pass through each cell can be controlled.
- the laser beams R, G, and B are adjusted in transmittance by the transmitted light adjusting unit 20 and transmitted through the polarizing plate 22 and then emitted from the synthetic laser beam generating unit 10. Therefore, the polarization angles of the laser beams R, G, and B included in the synthetic laser beam C coincide with each other.
- the synthetic laser beam C emitted from the synthetic laser beam generator 10 travels to the scanning unit 40.
- the temperature detection unit 30 includes a thermistor that detects the temperature of the liquid crystal cell 21, and supplies temperature data indicating the detection temperature to the control unit 300 described later.
- the temperature detection unit 30 is provided on the substrate of the liquid crystal cell 21.
- the temperature detection unit 30 is not limited to the one directly disposed on the liquid crystal cell 21 and may be located at a position where the temperature of the liquid crystal cell 21 can be indirectly detected.
- the liquid crystal cell 21 may be provided on a separate substrate.
- the temperature detector 30 may be a device that detects temperature by infrared radiation, a semiconductor temperature sensor, or the like.
- the temperature detection part 30 may be provided in the liquid crystal cells 21r, 21g, and 21b corresponding to each color of the laser light, and may detect the temperature for each of the liquid crystal cells 21r, 21g, and 21b.
- the scanning unit 40 is composed of a MEMS (Micro Electro Mechanical System) scanner (MEMS mirror), scans the synthetic laser light C, and generates a display image M on the transmission screen 50. Further, the scanning unit 40 has a function of detecting a shake position for each piezo element that moves each mirror included in the scanning unit 40, and outputs scanning position detection data indicating the detected position to the scanning driving unit 400.
- MEMS Micro Electro Mechanical System
- the transmission screen 50 displays the display image M on the front side by receiving the synthesized laser beam C from the scanning unit 40 on the back side and transmitting and diffusing it.
- the transmission screen 50 includes a holographic diffuser, a microlens array, a diffusion plate, and the like.
- FIG. 5 shows an example of the display image M when the transmission screen 50 is viewed from the scanning unit 40 side.
- the display image M is generated by the scanning unit 40 performing vertical scanning while horizontally scanning the synthetic laser light C on the transmission screen 50 as indicated by broken lines in FIG.
- the display image M drawn by the scanning unit 40 is set to be smaller than the actual scanable range 50a.
- scanning is performed by shaking the reflection surface of the mirror included in the scanning unit 40 by resonance, so that the mirror operation speed is slowed down or stopped near the reciprocation switching point of scanning. For this reason, if the region where the display image M is generated is set to the entire scannable range 50a, the display image M is distorted or the resolution is lowered. For this reason, the area (display area 50b) where the display image M is generated is set to an area that is smaller than the scannable range 50a and does not include the vicinity of the scan switching point.
- the light intensity detector 60 detects and detects the light intensity A (the light intensity Ar of the laser light R, the light intensity Ag of the laser light G, and the light intensity Ab of the laser light B) of each of the laser lights R, G, and B.
- Light intensity data indicating the light intensity A is supplied to the control unit 300 described later.
- the light intensity detection unit 60 includes, for example, a color sensor having RGB color optical filters and a three-channel photodiode.
- the light intensity detector 60 is provided on the back surface of the transmissive screen 50 as shown in FIG. Further, as shown in FIG. 5, the light intensity detector 60 is provided at an appropriate position within the scannable range 50a and outside the display area 50b. As a result, the light intensities of the laser beams R, G, and B can be detected without affecting the scanning of the display image M.
- the reflection unit 70 is an optical system provided between the transmission screen 50 and the windshield 3 so that the display image M displayed on the front surface of the transmission screen 50 is connected as a virtual image V at a desired position and size. It is.
- the reflection unit 70 according to this embodiment includes a plane mirror 71 and a magnifying mirror 72.
- the plane mirror 71 reflects the display light K representing the display image M displayed on the transmission screen 50 toward the magnifying mirror 72.
- the magnifying mirror 72 is formed of a concave mirror or the like, and reflects the display light K toward the windshield 3 by reflecting the display light K from the flat mirror 71 on the concave surface. As a result, the size of the virtual image V to be connected becomes a size obtained by enlarging the display image M.
- the housing 80 accommodates the above-described parts (synthetic laser light generation part 10 to reflection part 70), and is formed of a light-shielding member.
- the housing 80 is formed with an opening through which the display light K reflected by the magnifying mirror 72 passes.
- a translucent part 81 is provided in the opening.
- the translucent part 81 is made of a translucent resin such as acrylic and transmits the display light K from the magnifying mirror 72.
- the translucent part 81 is formed in a curved shape so that external light is not reflected in the direction of the user 4.
- the external light intensity detection unit 90 is composed of a light sensor, for example, and detects external light intensity (for example, illuminance).
- the outside light intensity detection unit 90 outputs outside light intensity data indicating the detected outside light intensity to the control unit 300 described later.
- FIG. 2 the example in which the external light intensity detection unit 90 is disposed on the inner surface of the translucent unit 81 is shown, but the installation location is arbitrary as long as the necessary external light intensity can be detected. .
- the display device 1 includes an LD driving unit 100, a liquid crystal driving unit 200, a control unit 300, and a scanning driving unit 400, as shown in FIG. These are mounted on, for example, a printed circuit board (not shown) disposed in the housing 80. These may be provided outside the housing 80.
- the LD driving unit 100 includes a driver IC (IntegratedIntegrCircuit) or the like, and each of the LDs 11r, 11g, and 11b is controlled by the control unit 300 using a PAM (Pulse Amplitude Modulation) method and a PWM (Pulse Width Modulation) method. Drive with.
- the LD driving unit 100 supplies a driving current to each of the LDs 11r to 11b according to the current control data supplied from the control unit 300.
- the liquid crystal driving unit 200 includes a driver IC or the like, and drives each of the red liquid crystal cell 21r, the green liquid crystal cell 21g, and the blue liquid crystal cell 21b under the control of the control unit 300.
- the liquid crystal driving unit 200 acquires the PWM value (data indicating the duty ratio) for each color output from the CPU 310, applies a voltage corresponding to the acquired PWM value to the liquid crystal cells 21r, 21g, and 21b for each color, and drives it. To do.
- the scanning drive unit 400 includes a driver IC and the like, and drives the scanning unit 40 under the control of the control unit 300.
- the scanning drive unit 400 drives the scanning unit 40, acquires the scanning position detection data output from the scanning unit 40, calculates feedback data based on the acquired scanning position detection data, and outputs the feedback data to the control unit 300. . Based on this feedback data, the control unit 300 can specify the current scanning position of the scanning unit 40.
- the control unit 300 includes a microcontroller, an FPGA (Field Programmable Gate Array), an ASIC (Application Specific Integrated Circuit), and the like, and includes a CPU 310 and a storage unit 320.
- FPGA Field Programmable Gate Array
- ASIC Application Specific Integrated Circuit
- the storage unit 320 includes a ROM (Read Only Memory), a RAM (Random Access Memory), a flash memory, and the like, and stores programs and various data necessary for the operation of the display device 1.
- the storage unit 320 stores operation program data for each process (transmitted light white balance adjustment process and white balance adjustment process) described later, and data for the liquid crystal drive table TA1 (FIG. 8) and correction table TA2 (FIG. 9). Etc. are stored in advance.
- the storage unit 320 temporarily stores various data such as the calculation result of the CPU 310.
- the CPU 310 controls each unit by reading a program from the storage unit 320 and executing the program.
- Image data for displaying the display image M from an ECU (Electronic Control Unit) 5 of the vehicle 2 is supplied to the CPU 310 by LVDS (Low Voltage Differential Signal) communication or the like. Note that at least a part of the image data may be stored in the storage unit 320 in advance.
- the CPU 310 controls the laser light emitting unit 11 through the LD driving unit 100 and also controls the scanning unit 40 through the scanning driving unit 400, thereby displaying the display image M requested by the image data. It is generated on the transmission screen 50.
- the display light K representing the display image M is emitted toward the windshield 3, and the user 4 can visually recognize the display image M as the virtual image V.
- the CPU 310 specifies the current scanning position of the synthetic laser light C on the transmission screen 50 based on the feedback data supplied from the scanning driving unit 400. Then, the laser beam emitting unit 11 is driven via the LD driving unit 100 at the timing when the scanning position overlaps the position of the light intensity detecting unit 60. At this time, the CPU 310 acquires the light intensity (Ar, Ag, Ab) for each color of the laser beams R, G, B detected by the light intensity detector 60.
- the display device 1 is activated, for example, in response to the activation switch of the vehicle 2 being turned on (ignition (IGN) or accessory position (ACC) is turned on), and performs various operations.
- the display device 1 can perform a general operation such as displaying the display image M in the display area 50b of the transmissive screen 50. The operation unique to the present embodiment will be described below.
- the display device 1 performs white balance adjustment of the display image M twice as a specific operation.
- the white balance adjusted by the transmitted light adjusting unit 20 out of the two white balance adjustments is referred to as “transmitted light white balance”.
- transmitted light white balance the transmitted light white balance adjustment process for adjusting the transmitted light white balance will be described with reference to FIGS.
- the CPU 310 starts the transmitted light white balance adjustment process shown in FIG. 7, and first acquires the external light intensity indicated by the external light intensity data supplied from the external light intensity detector 90 (step). A1).
- the CPU 310 performs a PWM value (duty ratio) for driving the liquid crystal cell 21 based on the acquired external light intensity P and the liquid crystal driving table TA1 (see FIG. 8) stored in the storage unit 320 in advance. Is calculated) (step A2).
- the liquid crystal drive table TA1 is data in which the external light intensity P is associated with the PWM values Dr, Dg, Db for driving the liquid crystal cells 21r, 21g, 21b. .
- P0 represents the minimum value of the external light intensity P
- Pk (k is a positive integer) represents the maximum value of the external light intensity P.
- j is an integer of 0 or more and k ⁇ 1 or less (0 ⁇ j ⁇ k ⁇ 1), and Pj + 1 is larger than Pj (Pj + 1> Pj).
- the index of each PWM value Dr, Dg, Db corresponds to the index of the external light intensity P.
- the red liquid crystal cell 21r will be described.
- the CPU 310 refers to the liquid crystal driving table TA1, and Dr_j and Dr_j + 1. And get. Then, the CPU 310 calculates the PWM value Dr for driving the red liquid crystal cell 21r by the linear interpolation method using the equation (1) shown below (Equation 1). Similarly, the CPU 310 calculates a PWM value Dg for driving the green liquid crystal cell 21g according to equation (2) shown in the following (Equation 1). Further, the CPU 310 calculates the PWM value Db for driving the blue liquid crystal cell 21b by the following equation (3) shown in (Equation 1).
- the PWM values Dr, Dg, Db of the liquid crystal cells at the same external light intensity P are the light intensities of the laser lights R, G, B after the light transmitted through the transmitted light adjusting unit 20.
- the ideal color mixture ratio is a light intensity ratio of the laser light R, the laser light G, and the laser light B that has an arbitrary xy chromaticity for becoming white.
- the laser beams R, G, and B that have passed through the transmitted light adjusting unit 20 have their white balance adjusted.
- the CPU 310 acquires the detected temperature indicated by the temperature data supplied from the temperature detection unit 30 (step A3).
- the CPU 310 considers the transmittance variation of the liquid crystal cell 21 due to the temperature change based on the acquired detected temperature T and the correction table TA2 (see FIG. 9) stored in the storage unit 320 in advance. , 11g and 11b are calculated (step A4).
- the correction table TA2 is data in which the external light intensity P and the correction coefficients Cr, Cg, and Cb corresponding to the liquid crystal cells 21r, 21g, and 21b are associated with each other.
- T0 represents the minimum value (for example, ⁇ 40 ° C.) of the temperature range assumed in consideration of the use environment of the display device 1
- Tn (n is a positive integer) is the maximum value of the temperature range ( For example, + 85 ° C.).
- M is an integer of 0 or more and n-1 or less (0 ⁇ m ⁇ n ⁇ 1)
- Pm + 1 is larger than Pm (Pm + 1> Pm).
- Pm + 1 and Pm are set to appropriate intervals such as a 5 ° C. interval and a 10 ° C. interval.
- the index of each correction coefficient Cr, Cg, Cb corresponds to the index of the detected temperature T.
- the red liquid crystal cell 21r will be described.
- the CPU 310 refers to the correction table TA2 and determines Cr_m and Cr_m + 1. get. Then, the CPU 310 calculates a correction coefficient Cr for driving the LD 11r by a linear interpolation method in consideration of the transmittance variation of the red liquid crystal cell 21r due to a temperature change, according to the equation (4) shown below (Equation 2). .
- the CPU 310 calculates the correction coefficient Cg for driving the LD 11g in consideration of the transmittance variation of the green liquid crystal cell 21g due to the temperature change, by the equation (5) shown in the following (Equation 2). In addition, the CPU 310 calculates a correction coefficient Cg for driving the LD 11g in consideration of the transmittance variation of the green liquid crystal cell 21g due to a temperature change, according to Equation (6) shown in the following (Equation 2).
- the CPU 310 calculates a correction PWM value based on the correction coefficients Cr, Cg, and Cb calculated in step A4 (step A5). Specifically, the PWM value calculated in step A2 is multiplied by the correction coefficient to calculate Cr ⁇ Dr, Cg ⁇ Dg, and Cb ⁇ Db as the corrected PWM values corresponding to each of the liquid crystal cells 21r, 21g, and 21b. To do.
- the CPU 310 outputs the calculated PWM value to the liquid crystal driving unit 200 (step A6). Specifically, the CPU 310 outputs the corrected PWM value Cr ⁇ Dr to the liquid crystal driving unit 200 to drive the liquid crystal cell 21r. Further, the CPU 310 drives the liquid crystal cell 21g by outputting the corrected PWM value Cg ⁇ Dg to the liquid crystal driving unit 200. Further, the CPU 310 drives the liquid crystal cell 21 b by outputting the corrected PWM value Cb ⁇ Db to the liquid crystal driving unit 200.
- FIG. 10 shows a graph of the relationship between the detected temperature T and the correction coefficients Cr, Cg, Cb in the correction table T2 of FIG.
- the value on the vertical axis at the point plotted with ⁇ is the correction coefficient Cr
- the value on the vertical axis at the point plotted with ⁇ is the correction coefficient Cg
- the value on the vertical axis at the point plotted with ⁇ is the correction coefficient.
- Cb is the correction coefficient.
- white balance adjustment with high accuracy is possible by providing a correction coefficient for each liquid crystal cell in consideration of transmittance variation due to temperature changes of the liquid crystal cells 21r, 21g, and 21b. .
- the laser beams R, G, and B whose white balance has been adjusted are emitted from the transmitted light adjusting unit 20.
- the CPU 310 repeatedly executes the transmitted light white balance adjustment processing including the above processing until the power of the display device 1 is turned off, for example.
- the white balance adjustment process will be described with reference to FIGS. As described above, the white balance is adjusted with higher accuracy by adjusting the white balance in the laser beams R, G, and B after passing through the transmitted light adjusting unit 20.
- the CPU 310 starts white balance shown in FIG. 11, and first acquires the light intensity indicated by the light intensity data supplied from the light intensity detector 60 (step B1). Specifically, the CPU 310 specifies the current scanning position of the combined laser light C on the transmission screen 50 based on the feedback data supplied from the scanning driving unit 400. Then, the laser beam emitting unit 11 is driven via the LD driving unit 100 at the timing when the scanning position overlaps the position of the light intensity detecting unit 60. At this time, the CPU 310 acquires the light intensity (Ar, Ag, Ab) for each color of the laser beams R, G, B detected by the light intensity detector 60.
- the ideal color mixture ratio is a light intensity ratio of the laser light R, the laser light G, and the laser light B that has an arbitrary xy chromaticity for becoming white.
- FIG. 12 shows a graph showing the relationship between the drive current of each of the LDs 11r, 11g, and 11b and the light intensity.
- the graph indicated by reference numeral 6r corresponds to the LD 11r
- the graph indicated by reference numeral 6g corresponds to the LD 11g
- the graph indicated by reference numeral 6b corresponds to the LD 11b.
- the figure shows an example in which the ideal light intensities Lr, Lg, and Lb that are the ideal color mixture ratio and the light intensities Ar, Ag, and Ab acquired from the light intensity detector 60 are shifted.
- the CPU 310 calculates Lr / Ar (Lr / Ar ⁇ 1 in the example of FIG. 12) as a correction coefficient by dividing the ideal light intensity by the acquired light intensity.
- the CPU 310 calculates Lg / Ag (Lg / Ag> 1 in the example of FIG. 12) as a correction coefficient by dividing the ideal light intensity by the acquired light intensity.
- the CPU 310 calculates, for example, Lb / Ab (Lb / Ab> 1 in the example of FIG. 12) as a correction coefficient.
- the CPU 310 drives the LDs 11r, 11g, and 11b by reflecting the calculated correction coefficient (step B3).
- the CPU 310 multiplies the current value by a correction coefficient, and in the case of PWM control, multiplies the PWM value (duty ratio) by the correction coefficient to obtain current control data to be supplied to the LD control unit 100. to correct.
- the corrected current control data is output to the LD driving unit 100 to drive the LDs 11r, 11g, and 11b.
- the drive current supplied to the LD 11r by the current control data before correction is Ir
- the drive current supplied to the LD 11r by the current control data corrected in step B3 is (Lr / Ar) ⁇ Ir.
- the LD 11r can emit light with the ideal light intensity Lr when a correction coefficient is added to the drive current.
- the LDs 11g and 11b can emit light with ideal light intensities Lg and Lb.
- each of the LDs 11r, 11g, and 11b is adjusted, and each LD is caused to emit light with the ideal light intensities Lr, Lg, and Lb. be able to. Thereby, the white balance of the display image M is adjusted with high accuracy.
- the current control data is preferably corrected at the maximum output (maximum gradation) of each of the LDs 11r, 11g, and 11b.
- the light intensity A acquired by the light intensity detector 60 can be increased, and the ratio of noise to the actual light intensity A can be minimized (that is, the S / N ratio (Signal-Noise ratio)). Can be increased and improved). Therefore, it is possible to adjust the white balance with high accuracy as the light intensity is detected with high accuracy.
- each of the LDs 11r, 11g, and 11b corresponds to the maximum gradation of each of the LDs 11r, 11g, and 11b, in this way, not only white display at the maximum gradation but also any arbitrary value below the maximum gradation. High-accuracy white balance can be reflected in white display in gradation (that is, gray scale).
- step B3 the calculated correction coefficient is reflected in the drive current to each of the LDs 11r, 11g, and 11b.
- the correction coefficient is reflected in the image data supplied from the ECU 5 (or stored in the storage unit 320 in advance). May be.
- the image data is composed of, for example, 8-bit data for each color of R, G, and B in one pixel.
- the current light intensity ratio is obtained.
- the ideal color mixture ratio may be corrected.
- the white balance may be adjusted by directly correcting the image data without correcting the drive currents of the LDs 11r, 11g, and 11b.
- the CPU 310 repeatedly executes the white balance adjustment process including the above processes until, for example, the display device 1 is turned off.
- the CPU 310 executes the flow of the transmitted light white balance adjustment process and the white balance adjustment process described above at intervals of several hundred msec. As a result, light control that does not give the user 4 a sense of incongruity and highly accurate color control can be performed.
- the transmitted light white balance adjustment is performed by the transmitted light adjusting unit 20, and the white balance adjustment is also performed for the laser beams R, G, and B after passing through the transmitted light adjusting unit 20.
- the display device 201 according to the first modification that performs white balance adjustment in the laser beams R, G, and B before entering the transmitted light adjusting unit 20 and the display device 301 according to the second modification will be described in order. To do. In the following, in order to facilitate understanding of the description, differences from the above embodiment will be mainly described.
- the light intensity detection unit 60 is not provided on the back surface of the transmission screen 50a. Instead, as shown in FIG. 13B, the display device 201 is disposed between the LD 11r and the condensing lens 12r, and a red light intensity detector 260r that detects the light intensity of the laser light R. , Disposed between the LD 11g and the condensing lens 12g, disposed between the LD 11b and the condensing lens 12b, and the green light intensity detecting portion 260g for detecting the light intensity of the laser light G. And a blue light intensity detector 260b for detecting the light intensity of the light source.
- Each light intensity detector 260r, 260g, 260b for each color includes a photodiode or the like.
- the red light intensity detector 260r outputs the light intensity Ar of the laser light R to the CPU 310.
- the green light intensity detection unit 260 g outputs the light intensity Ag of the laser light G to the CPU 310.
- the blue light intensity detection unit 260 b outputs the light intensity Ab of the laser light R to the CPU 310.
- the red light intensity detector 260r may be disposed between the condenser lens 12r and the liquid crystal cell 21. The same applies to the green and blue light intensity detectors 260g and 260b.
- the CPU 310 performs the white balance shown in FIG. 11 based on the light intensities Ar, Ag, and Ab acquired from the light intensity detectors 260r, 260g, and 260b for each color. Execute the adjustment process. That is, the embodiment and the modification 1 are different in that the laser beam to be sensed is light after being transmitted through the transmitted light adjusting unit 20 or light before being transmitted. Then, the laser beams R, G, and B adjusted by the white balance adjustment process shown in FIG. 11 enter the transmitted light adjustment unit 20, and the CPU 310 adjusts the transmitted light white balance adjustment shown in FIG. Execute the process. As in the first modification, white balance adjustment may be performed in advance for the laser beams R, G, and B before entering the transmitted light adjusting unit 20.
- Modification 2 As shown in FIG. 14A, in the display device 301 according to the modified example 2, the light intensity detection unit 60 is provided on the back surface of the transmissive screen 50a as in the above-described embodiment. Furthermore, as in Modification 1, as shown in FIG. 14B, the display device 301 includes light intensity detection units 260r, 260g, and 260b for each color.
- the CPU 310 first shows the light intensity Ar, Ag, Ab obtained from the light intensity detection units 260r, 260g, 260b for each color as shown in FIG. Execute white balance adjustment processing. Then, the laser beams R, G, and B adjusted by the white balance adjustment process shown in FIG. 11 enter the transmitted light adjustment unit 20, and the CPU 310 adjusts the transmitted light white balance adjustment shown in FIG. Execute the process. Further, the CPU 310 executes the white balance adjustment process shown in FIG. 11 by the light after passing through the transmitted light adjusting unit 20 as in the above embodiment. That is, in Modification 2, the transmitted light adjusting unit 20 adjusts the transmitted light white balance, and the transmitted light adjusting unit 20 also adjusts the white balance in the laser light before and after transmission. In this way, white balance adjustment may be performed three times.
- the transmitted light adjusting unit 20 may be disposed between the laser beam emitting unit 11 and the light collecting unit 12. Further, the transmitted light adjusting unit 20 does not need to control the transmittance for each color of the laser beams R, G, and B. In this case, the position after the multiplexing unit 13, that is, the light of the combined laser beam C. It may be arranged on the road.
- a similar polarizing plate may be further provided on the laser light emitting unit 11 side.
- the added polarizing plate is arranged in a relationship between the polarizing plate 22 and crossed Nicols.
- the liquid crystal cell 21 is not limited to the VA type, and may be a TN (Twisted Nematic) type, an STN (Super Twisted Nematic) type, an IPS (In Plane Switching) type, or the like.
- TN Transmission Nematic
- STN Super Twisted Nematic
- IPS In Plane Switching
- the light intensity detected by the light intensity detection unit 60 may be a physical quantity that changes according to the current supplied to the laser light emitting unit 11, and may be luminance, illuminance, luminous intensity, or the like.
- the external light intensity detected by the external light intensity detector 90 is not limited to illuminance, and may be brightness, luminous intensity, or the like.
- the CPU 310 may acquire the PWM value corresponding to the external light intensity closer to the acquired external light intensity P with reference to the liquid crystal driving table TA1.
- the CPU 310 may acquire the correction coefficient corresponding to the detected temperature closer to the acquired detected temperature T with reference to the correction table TA2.
- the example in which the CPU 310 calculates the correction coefficient by dividing the ideal light intensity by the acquired light intensity in the white balance adjustment process shown in FIG. 11 is not limited to this. If the LDs 11r, 11g, and 11b can emit light with the ideal light intensity, the correction coefficient calculation method is arbitrary.
- the CPU 310 may acquire the light intensities Ar, Ag, Ab of the laser beams R, G, B from the light intensity detector 60 at the same time, or may acquire them in time division for each color.
- the timing of acquisition is arbitrary. The same applies to the acquisition timing of the light intensities Ar, Ag, and Ab from the color light intensity detectors 260r, 260g, and 260b according to the first and second modifications.
- gradations may be arranged to express gradations with the four primary colors, or gradations may be expressed with one or two LDs.
- the example in which the display light K is reflected by the reflecting unit 70 including two mirrors and reaches the windshield 3 is not limited thereto.
- the reflection unit 70 may be composed of one or three or more mirrors.
- the display light K from the transmissive screen 50 may be emitted toward the windshield 3 or the combiner dedicated to the apparatus without passing through such a reflection portion.
- an example of a vehicle on which the display device 1 (hereinafter, the same applies to the display devices 201 and 301 according to modifications) is mounted as a vehicle, but is not limited thereto.
- the display device 1 can also be installed on other vehicles (ships, aircraft, etc.). Furthermore, it is not restricted to what is installed in a vehicle.
- the display device 1 is configured integrally with the dashboard of the vehicle.
- the display device 1 is, for example, a stationary type (retrofitted type) installed on the dashboard of the vehicle. May be.
- the display device 1 is configured as a head-up display (HUD) device
- HUD head-up display
- the present invention is not limited to this.
- Other display devices for example, car navigation devices
- the HUD device allows the display image to be visually recognized overlaid on the background (landscape), it is particularly necessary to adjust the display brightness, and since it is often mounted on the vehicle, the temperature change is particularly severe.
- the HUD device is suitable as the display device that executes each process as described above.
- the laser light intensity adjusting device includes a light source (LD 11r, 11g, 11b) that emits laser light, a scanning unit 40 that scans the laser light emitted from the light source to generate a display image M, and a light source to the scanning unit 40.
- a transmitted light adjusting unit 20 that is positioned on the optical path and transmits laser light emitted from a light source with a predetermined transmittance.
- the transmitted light adjusting unit 20 includes a liquid crystal cell 21 and a polarizing plate 22.
- a temperature detection unit 30 that detects the temperature and a control unit 300 that drives the liquid crystal cell 21 to control the transmittance of the transmitted light adjustment unit 20 are provided.
- the control unit 300 Based on the temperature detected by the temperature detection unit 30, the control unit 300 corrects the variation in the transmittance due to the temperature change of the liquid crystal cell 21 to control the transmittance of the transmitted light adjustment unit 20 and reaches the scanning unit 40. Adjust the light intensity of the laser beam. Since it did in this way, while controlling the transmittance
- the laser light intensity adjusting device further includes a storage unit 320 that stores correction data associated with the temperature of the liquid crystal cell 21 (an example of correction coefficients Cr, Cg, and Cb in the correction table TA2). Controls the transmittance of the transmitted light adjusting unit 20 by correcting the variation of the transmittance due to the temperature change of the liquid crystal cell 21 based on the temperature detected by the temperature detecting unit 30 and the correction data. In this case, if the correction data is provided for each color of the laser beams R, G, and B, the laser beam can be adjusted in consideration of the temperature dependency of the transmittance of each color liquid crystal cell 21r, 21g, 21b. good.
- the transmittance is controlled for each color of the laser light by the control unit 300, and the control unit 300 adjusts the light intensity for each color of the laser light reaching the scanning unit 40,
- the white balance of the display image M is adjusted.
- the display image M can be displayed with a low luminance under a wide temperature range, and can be displayed with an appropriate white balance.
- a transmitted light intensity detecting unit (an example of the light intensity detecting unit 60) that detects the light intensity of the laser light transmitted through the transmitted light adjusting unit 20 is further provided.
- the control part 300 adjusts the electric current supplied to the light source (LD11r, 11g, 11b) via the LD drive part 100 based on the light intensity which the (i) transmitted light intensity detection part detected, Further, the white balance of the display image M is adjusted, or (ii) the white balance of the display image is further adjusted by correcting the image data based on the light intensity detected by the transmitted light intensity detector.
- the light intensity detecting unit that detects the light intensity of the laser light before passing through the transmitted light adjusting unit 20 (an example of the light intensity detecting units 260r, 260g, and 260b for each color).
- the control part 300 adjusts the electric current supplied to a light source based on the light intensity which the light intensity detection part detected (i) display image M also in the laser beam before permeate
- the white balance of the display image M is also adjusted by adjusting the white balance of (ii) or (ii) correcting the image data based on the light intensity detected by the light intensity detector.
- the second modification further includes a transmitted light intensity detecting unit (an example of the light intensity detecting unit 60) that detects the light intensity of the laser light transmitted through the transmitted light adjusting unit 20, and the control unit 300 includes The adjusted white balance is corrected based on the light intensity detected by the light intensity detector.
- a transmitted light intensity detecting unit an example of the light intensity detecting unit 60
- the control unit 300 includes The adjusted white balance is corrected based on the light intensity detected by the light intensity detector.
- the present invention is applicable to a display device (laser scanning image generating device) that generates an image by scanning a laser beam, and is particularly mounted on a moving body such as a vehicle and has a wide luminance in a wide operating temperature range. It is also applicable as a vehicle display device (vehicle laser scanning image generation device) in a head-up display that requires image generation.
- a display device laser scanning image generating device
- vehicle laser scanning image generation device in a head-up display that requires image generation.
- SYMBOLS 1 Display apparatus 10 Synthetic laser beam production
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Abstract
In order to stably adjust low-intensity laser light, even in a wide temperature range, a laser light intensity adjustment device is provided that comprises: light sources (LD11r, 11g, 11b) that emit laser light; a scanning unit (40) that scans laser light generated by the light sources and generates a display image; a transmitted light adjustment unit having a liquid crystal cell (21) and a polarizing plate and which transmits laser light generated by the light sources, at a prescribed transmittance rate; a temperature detection unit (30) that detects the temperature of the liquid crystal cell (21); and a control unit (300) that drives the liquid crystal cell (21) and controls the transmittance rate of the transmitted light adjustment unit. The control unit (300) corrects the amount of fluctuation in the transmittance rate caused by temperature changes in the liquid crystal cell (21), controls the transmittance rate of the transmitted light adjustment unit, and adjusts the intensity of the laser light that reaches the scanning unit (40), on the basis of the temperature detected by the temperature detection unit (30).
Description
本発明は、レーザー光強度調整装置に関する。
The present invention relates to a laser beam intensity adjusting device.
レーザー光源(レーザーダイオード)を駆動するレーザー光強度調整装置として、特許文献1に開示されたものがある。特許文献1に開示された装置は、レーザー光源と、レーザー光を走査して表示画像を生成する走査部との間に、液晶セルと偏光板を配置した構成のものである。この装置は、液晶セルと偏光板を透過するレーザー光の透過率を、液晶セルを駆動制御して調整する。これにより、光源の制御だけでは困難である低強度の光で表示画像を生成することが可能である。
A laser light intensity adjusting device that drives a laser light source (laser diode) is disclosed in Patent Document 1. The apparatus disclosed in Patent Document 1 has a configuration in which a liquid crystal cell and a polarizing plate are arranged between a laser light source and a scanning unit that scans the laser light to generate a display image. This apparatus adjusts the transmittance of the laser light transmitted through the liquid crystal cell and the polarizing plate by driving and controlling the liquid crystal cell. This makes it possible to generate a display image with low-intensity light, which is difficult only by controlling the light source.
液晶セルの透過率には温度依存性がある。そのため、特許文献1に開示された装置の構成では、目標となるレーザー光の強度と実際の強度との間にずれが生じてしまうという問題がある。この種のレーザー光強度調整装置を、例えば車載の表示装置に組み込んだ場合、雰囲気温度の範囲が広範になるため、この問題は顕著になる。
The transmittance of the liquid crystal cell is temperature dependent. For this reason, the configuration of the apparatus disclosed in Patent Document 1 has a problem in that a deviation occurs between the target laser light intensity and the actual intensity. When this type of laser light intensity adjusting device is incorporated into an in-vehicle display device, for example, this problem becomes significant because the range of the atmospheric temperature becomes wide.
本発明は、上記実情に鑑みてなされたものであり、広い温度範囲においても、低強度のレーザー光を安定して調整することができるレーザー光強度調整装置を提供することを目的とする。
The present invention has been made in view of the above circumstances, and an object thereof is to provide a laser light intensity adjusting device capable of stably adjusting a low-intensity laser beam even in a wide temperature range.
上記目的を達成するため、本発明に係るレーザー光強度調整装置は、
レーザー光を発する光源と、
前記光源が発したレーザー光を走査して表示画像を生成する走査部と、
前記光源から前記走査部へと至る光路上に位置し、前記光源が発したレーザー光を所定の透過率で透過させる透過光調整部であって、液晶セルと偏光板とを有する透過光調整部と、
前記液晶セルの温度を検出する温度検出部と、
前記液晶セルを駆動して前記透過光調整部の透過率を制御する制御部と、を備え、
前記制御部は、前記温度検出部が検出した温度に基づいて、前記液晶セルの温度変化による透過率の変動分を補正して前記透過光調整部の透過率を制御し、前記走査部に到達するレーザー光の光強度を調整する、
ことを特徴とする。 In order to achieve the above object, a laser beam intensity adjusting device according to the present invention is
A light source that emits laser light;
A scanning unit that scans laser light emitted from the light source to generate a display image;
A transmitted light adjusting unit that is located on an optical path from the light source to the scanning unit and transmits laser light emitted from the light source with a predetermined transmittance, and includes a liquid crystal cell and a polarizing plate. When,
A temperature detector for detecting the temperature of the liquid crystal cell;
A control unit for driving the liquid crystal cell to control the transmittance of the transmitted light adjusting unit,
The control unit controls the transmittance of the transmitted light adjustment unit by correcting the variation of the transmittance due to the temperature change of the liquid crystal cell based on the temperature detected by the temperature detection unit, and reaches the scanning unit Adjust the light intensity of the laser light,
It is characterized by that.
レーザー光を発する光源と、
前記光源が発したレーザー光を走査して表示画像を生成する走査部と、
前記光源から前記走査部へと至る光路上に位置し、前記光源が発したレーザー光を所定の透過率で透過させる透過光調整部であって、液晶セルと偏光板とを有する透過光調整部と、
前記液晶セルの温度を検出する温度検出部と、
前記液晶セルを駆動して前記透過光調整部の透過率を制御する制御部と、を備え、
前記制御部は、前記温度検出部が検出した温度に基づいて、前記液晶セルの温度変化による透過率の変動分を補正して前記透過光調整部の透過率を制御し、前記走査部に到達するレーザー光の光強度を調整する、
ことを特徴とする。 In order to achieve the above object, a laser beam intensity adjusting device according to the present invention is
A light source that emits laser light;
A scanning unit that scans laser light emitted from the light source to generate a display image;
A transmitted light adjusting unit that is located on an optical path from the light source to the scanning unit and transmits laser light emitted from the light source with a predetermined transmittance, and includes a liquid crystal cell and a polarizing plate. When,
A temperature detector for detecting the temperature of the liquid crystal cell;
A control unit for driving the liquid crystal cell to control the transmittance of the transmitted light adjusting unit,
The control unit controls the transmittance of the transmitted light adjustment unit by correcting the variation of the transmittance due to the temperature change of the liquid crystal cell based on the temperature detected by the temperature detection unit, and reaches the scanning unit Adjust the light intensity of the laser light,
It is characterized by that.
本発明によれば、広い温度範囲においても、低強度のレーザー光を安定して調整することができる。
According to the present invention, it is possible to stably adjust a low-intensity laser beam even in a wide temperature range.
本発明の一実施形態について図面を参照して説明する。
An embodiment of the present invention will be described with reference to the drawings.
本実施形態に係るレーザー光強度調整装置は、図1、図2に示す表示装置1が備えるものである。
The laser light intensity adjusting device according to the present embodiment is provided in the display device 1 shown in FIGS.
表示装置1は、車両2のダッシュボードに配設され、所定の表示画像Mを表す光(以下、表示光K)をウインドシールド3に向けて出射するヘッドアップディスプレイ装置として構成されている。この表示装置1は、ウインドシールド3で反射した表示光Kにより、例えば車両2の運転者であるユーザ4に、表示画像Mを虚像Vとして視認させる。表示画像Mは、例えば、車両2に関する情報(以下、車両情報)を報知するための画像である。
The display device 1 is arranged on a dashboard of the vehicle 2 and is configured as a head-up display device that emits light representing a predetermined display image M (hereinafter, display light K) toward the windshield 3. The display device 1 causes the user 4 who is a driver of the vehicle 2 to visually recognize the display image M as a virtual image V by the display light K reflected by the windshield 3. The display image M is an image for notifying information about the vehicle 2 (hereinafter, vehicle information), for example.
表示装置1は、図2に示すように、合成レーザー光生成部10と、透過光調整部20と、温度検出部30と、走査部40と、透過スクリーン50と、光強度検出部60と、反射部70と、筐体80と、外光強度検出部90と、を備える。
As shown in FIG. 2, the display device 1 includes a synthetic laser light generation unit 10, a transmitted light adjustment unit 20, a temperature detection unit 30, a scanning unit 40, a transmission screen 50, a light intensity detection unit 60, A reflection unit 70, a housing 80, and an external light intensity detection unit 90 are provided.
合成レーザー光生成部10は、合成レーザー光Cを生成し、走査部40に向け出射する。合成レーザー光生成部10は、図3に示すように、レーザー光出射部11と、集光部12と、合波ユニット13と、を有する。
The synthetic laser beam generator 10 generates a synthetic laser beam C and emits it toward the scanning unit 40. As shown in FIG. 3, the synthetic laser light generation unit 10 includes a laser light emission unit 11, a condensing unit 12, and a multiplexing unit 13.
レーザー光出射部11は、赤色のレーザー光Rを出射するレーザーダイオード(LD)11rと、緑色のレーザー光Gを出射するLD11gと、青色のレーザー光Bを出射するLD11bと、を有する。LD11r,11g,11bは、後述するLD駆動部100から供給される駆動電流により、各々が所定の光強度及びタイミングで発光する。
The laser beam emitting unit 11 includes a laser diode (LD) 11r that emits red laser beam R, an LD 11g that emits green laser beam G, and an LD 11b that emits blue laser beam B. Each of the LDs 11r, 11g, and 11b emits light at a predetermined light intensity and timing by a driving current supplied from an LD driving unit 100 described later.
集光部12は、LD11が出射した各レーザー光R,G,Bを集光して収束光とする。集光部12は、LD11r,11g,11bの各々に対応する集光レンズ12r,12g,12bを備える。集光レンズ12rは、LD11rが発するレーザー光Rの光路上に位置する。集光レンズ12g,12bとLD11g,11bとの対応関係についても同様である。
The condensing unit 12 condenses the laser beams R, G, and B emitted from the LD 11 to form convergent light. The condensing unit 12 includes condensing lenses 12r, 12g, and 12b corresponding to the LDs 11r, 11g, and 11b, respectively. The condenser lens 12r is located on the optical path of the laser light R emitted from the LD 11r. The same applies to the correspondence between the condenser lenses 12g and 12b and the LDs 11g and 11b.
合波ユニット13は、LD11から出射され、集光部12を介して到達した各レーザー光R,G,Bを合波して、合成レーザー光Cを生成する。合波ユニット13は、平面鏡等からなる反射部13rと、それぞれが特定の波長の光を反射するがその他の波長の光は透過するダイクロイックミラー等からなる合波部13g及び合波部13bと、から構成されている。
反射部13rは、入射したレーザー光Rを、合波部13gに向けて反射させる。
合波部13gは、反射部13rからのレーザー光Rをそのまま透過させると共に、入射したレーザー光Gを合波部13bに向けて反射させる。これにより、合波部13gからは、レーザー光RとGとが合波されたレーザー光が合波部13bに向け出射される。
合波部13bは、合波部13gからのレーザー光をそのまま透過させると共に、入射したレーザー光Bを走査部40に向けて反射させる。このようにして、合波部13bから、各レーザー光R,G,Bが合波された合成レーザー光Cが走査部40に向け出射される。 The multiplexing unit 13 combines the laser beams R, G, and B emitted from theLD 11 and reached via the light collecting unit 12 to generate a combined laser beam C. The multiplexing unit 13 includes a reflecting unit 13r made of a plane mirror or the like, a multiplexing unit 13g and a multiplexing unit 13b each made of a dichroic mirror that reflects light of a specific wavelength but transmits light of other wavelengths, It is composed of
Thereflection unit 13r reflects the incident laser light R toward the multiplexing unit 13g.
Themultiplexing unit 13g transmits the laser beam R from the reflection unit 13r as it is, and reflects the incident laser beam G toward the multiplexing unit 13b. Thereby, the laser beam obtained by combining the laser beams R and G is emitted from the combining unit 13g toward the combining unit 13b.
Themultiplexing unit 13 b transmits the laser beam from the multiplexing unit 13 g as it is and reflects the incident laser beam B toward the scanning unit 40. In this way, the combined laser beam C obtained by combining the laser beams R, G, and B is emitted from the combining unit 13 b toward the scanning unit 40.
反射部13rは、入射したレーザー光Rを、合波部13gに向けて反射させる。
合波部13gは、反射部13rからのレーザー光Rをそのまま透過させると共に、入射したレーザー光Gを合波部13bに向けて反射させる。これにより、合波部13gからは、レーザー光RとGとが合波されたレーザー光が合波部13bに向け出射される。
合波部13bは、合波部13gからのレーザー光をそのまま透過させると共に、入射したレーザー光Bを走査部40に向けて反射させる。このようにして、合波部13bから、各レーザー光R,G,Bが合波された合成レーザー光Cが走査部40に向け出射される。 The multiplexing unit 13 combines the laser beams R, G, and B emitted from the
The
The
The
透過光調整部20は、集光部12と合波ユニット13の間に位置し、LD11が発した各レーザー光R,G,Bを所定の透過率で透過させる。透過光調整部20は、液晶セル21と、偏光板22と、を有する。
The transmitted light adjusting unit 20 is located between the condensing unit 12 and the multiplexing unit 13 and transmits each laser beam R, G, B emitted from the LD 11 with a predetermined transmittance. The transmitted light adjusting unit 20 includes a liquid crystal cell 21 and a polarizing plate 22.
液晶セル21は、一対の透明基板と、基板間に封入された液晶層とを有する。液晶セル21の各透明基板の液晶層側には、ITO(Indium Tin Oxide)等から透明電極が形成されている。液晶セル21は、図4(a)(b)に示すように、レーザー光Rが入射する赤色用液晶セル21rと、レーザーGが入射する緑色用液晶セル21gと、レーザー光Bが入射する青色用液晶セル21bと、を有する。液晶セル21r,21g,21bは、後述する制御部300の制御の下で液晶駆動部200を介して、各々独立して駆動電圧が印加される。液晶セル21r,21g,21bは、各セルに共用の一対の透明基板に、セル毎に駆動電圧を印加可能な透明電極が設けられることで構成されていてもよいし、各々別体の液晶セルとして構成されていてもよい。本実施形態に係る液晶セル21は、VA(Vertical Alignment)型である。
The liquid crystal cell 21 has a pair of transparent substrates and a liquid crystal layer sealed between the substrates. Transparent electrodes are formed of ITO (Indium 基板 Tin Oxide) or the like on the liquid crystal layer side of each transparent substrate of the liquid crystal cell 21. As shown in FIGS. 4A and 4B, the liquid crystal cell 21 includes a red liquid crystal cell 21r into which the laser light R is incident, a green liquid crystal cell 21g into which the laser G is incident, and a blue color into which the laser light B is incident. Liquid crystal cell 21b. A driving voltage is independently applied to the liquid crystal cells 21r, 21g, and 21b via the liquid crystal driving unit 200 under the control of the control unit 300 described later. The liquid crystal cells 21r, 21g, and 21b may be configured by providing a transparent electrode capable of applying a driving voltage for each cell on a pair of transparent substrates shared by the cells, or separate liquid crystal cells. It may be configured as. The liquid crystal cell 21 according to the present embodiment is a VA (Vertical Alignment) type.
偏光板22は、液晶セル21を透過したレーザー光R,G,Bの光路上に配置されている。偏光板22は、ワイヤグリッド偏光板、ヨウ素系や色素系の偏光板、ガラス偏光子などから構成されている。なお、偏光板22は、吸収型であっても、反射型であってもよい。図4(a)(b)に示すように、偏光板22は透過軸22aを有し、入射した光のうち、透過軸22aと平行な偏光角度の光を透過させ、それ以外の偏光角度の光を透過させない。
なお、各LD11r,11g,11bは、出射する光の偏光角度が偏光板22の透過軸22aと直交するように配置されている。また、偏光板22の透過軸22aの向きは、ウインドシールド3の反射率の偏光依存性を考慮して決定される。 Thepolarizing plate 22 is disposed on the optical path of the laser beams R, G, and B transmitted through the liquid crystal cell 21. The polarizing plate 22 includes a wire grid polarizing plate, an iodine-based or pigment-based polarizing plate, a glass polarizer, and the like. The polarizing plate 22 may be an absorption type or a reflection type. As shown in FIGS. 4 (a) and 4 (b), the polarizing plate 22 has a transmission axis 22a, and transmits light having a polarization angle parallel to the transmission axis 22a out of the incident light, and other polarization angles. Does not transmit light.
Each of the LDs 11r, 11g, and 11b is disposed so that the polarization angle of the emitted light is orthogonal to the transmission axis 22a of the polarizing plate 22. The direction of the transmission axis 22a of the polarizing plate 22 is determined in consideration of the polarization dependency of the reflectance of the windshield 3.
なお、各LD11r,11g,11bは、出射する光の偏光角度が偏光板22の透過軸22aと直交するように配置されている。また、偏光板22の透過軸22aの向きは、ウインドシールド3の反射率の偏光依存性を考慮して決定される。 The
Each of the
ここで、図4(a)(b)を用いて、透過光調整部20におけるレーザー光R,G,Bの偏光について説明する。図4(a)は、レーザー光R,G,Bが透過光調整部20を透過しない場合を示す図であり、図4(b)は、レーザー光R,G,Bが透過光調整部20を透過する場合を示す図である。
前述のように、液晶セル21r,21g,21bの各々には独立して駆動電圧が印加されるが、ここでは、説明の理解を容易にするため、各液晶セル21r,21g,21bに共通のオフ電圧・オン電圧が印加されるものとする。 Here, the polarization of the laser beams R, G, and B in the transmittedlight adjustment unit 20 will be described with reference to FIGS. FIG. 4A is a diagram illustrating a case where the laser beams R, G, and B do not pass through the transmitted light adjustment unit 20, and FIG. 4B illustrates that the laser beams R, G, and B are transmitted light adjustment unit 20. FIG.
As described above, a driving voltage is independently applied to each of the liquid crystal cells 21r, 21g, and 21b. Here, in order to facilitate understanding of the description, the liquid crystal cells 21r, 21g, and 21b are common. It is assumed that an off voltage and an on voltage are applied.
前述のように、液晶セル21r,21g,21bの各々には独立して駆動電圧が印加されるが、ここでは、説明の理解を容易にするため、各液晶セル21r,21g,21bに共通のオフ電圧・オン電圧が印加されるものとする。 Here, the polarization of the laser beams R, G, and B in the transmitted
As described above, a driving voltage is independently applied to each of the
(レーザー光不透過時)
表示装置1では、液晶セル21の液晶分子が倒れ始める閾電圧よりも低い値にオフ電圧が設定されている。そのため、液晶セル21にオフ電圧を印加しても液晶分子は垂直配向したままである。この場合、レーザー光R,G,Bは、液晶セル21を透過しても偏光角度がほとんど変化しない。そのため、レーザー光R,G,Bの偏光角度と直交する透過軸22aを有する偏光板22を透過しない(図4(a)参照)。 (When laser light is not transmitted)
In thedisplay device 1, the off voltage is set to a value lower than the threshold voltage at which the liquid crystal molecules of the liquid crystal cell 21 start to fall. Therefore, the liquid crystal molecules remain vertically aligned even when an off voltage is applied to the liquid crystal cell 21. In this case, even if the laser beams R, G, and B are transmitted through the liquid crystal cell 21, the polarization angle hardly changes. Therefore, the light does not pass through the polarizing plate 22 having the transmission axis 22a perpendicular to the polarization angles of the laser beams R, G, and B (see FIG. 4A).
表示装置1では、液晶セル21の液晶分子が倒れ始める閾電圧よりも低い値にオフ電圧が設定されている。そのため、液晶セル21にオフ電圧を印加しても液晶分子は垂直配向したままである。この場合、レーザー光R,G,Bは、液晶セル21を透過しても偏光角度がほとんど変化しない。そのため、レーザー光R,G,Bの偏光角度と直交する透過軸22aを有する偏光板22を透過しない(図4(a)参照)。 (When laser light is not transmitted)
In the
(レーザー光透過時)
一方、液晶セル21に閾電圧よりも高く設定されたオン電圧を印加すると、液晶セル21の液晶分子は透明基板と平行になるように挙動する。これにより、液晶セル21を透過するレーザー光R,G,Bに複屈折が起き、偏光板22を透過したレーザー光R,G,Bは、偏光板22を透過軸22aに沿った偏光角度の光として透過する(図4(b)参照)。 (When transmitting laser light)
On the other hand, when an ON voltage set higher than the threshold voltage is applied to theliquid crystal cell 21, the liquid crystal molecules in the liquid crystal cell 21 behave in parallel with the transparent substrate. Thereby, birefringence occurs in the laser beams R, G, and B transmitted through the liquid crystal cell 21, and the laser beams R, G, and B transmitted through the polarizing plate 22 have a polarization angle along the transmission axis 22a. It transmits as light (see FIG. 4B).
一方、液晶セル21に閾電圧よりも高く設定されたオン電圧を印加すると、液晶セル21の液晶分子は透明基板と平行になるように挙動する。これにより、液晶セル21を透過するレーザー光R,G,Bに複屈折が起き、偏光板22を透過したレーザー光R,G,Bは、偏光板22を透過軸22aに沿った偏光角度の光として透過する(図4(b)参照)。 (When transmitting laser light)
On the other hand, when an ON voltage set higher than the threshold voltage is applied to the
以上の説明は、レーザー光が不透過、又はほとんどが透過する例を示したが、実際にはこの限りではない。液晶セル21への印加電圧と透過率とは、比例関係にあるため(概ね線形の関係にみなせるため)、液晶セル21への印加電圧の大きさを制御することで、レーザー光の偏光角度を0°~90°の範囲で任意に制御でき、レーザー光R,G,Bの透過率を制御することができる。つまり、液晶セル21r,21g,21bの各々に印加する電圧を制御することで、各セルを透過するレーザー光R,G,Bの透過率を制御することができる。
Although the above explanation has shown an example in which laser light is not transmitted or mostly transmitted, this is not the case. Since the voltage applied to the liquid crystal cell 21 and the transmittance are in a proportional relationship (since it can be regarded as a substantially linear relationship), the polarization angle of the laser light can be controlled by controlling the magnitude of the voltage applied to the liquid crystal cell 21. It can be arbitrarily controlled in the range of 0 ° to 90 °, and the transmittance of the laser beams R, G, and B can be controlled. That is, by controlling the voltage applied to each of the liquid crystal cells 21r, 21g, and 21b, the transmittance of the laser beams R, G, and B that pass through each cell can be controlled.
このように、各レーザー光R,G,Bは、透過光調整部20で透過率が調整されると共に、偏光板22を透過した後に、合成レーザー光生成部10から出射される。したがって、合成レーザー光Cが含むレーザー光R,G,Bの偏光角度は一致している。合成レーザー光生成部10が出射した合成レーザー光Cは、走査部40に向かう。
As described above, the laser beams R, G, and B are adjusted in transmittance by the transmitted light adjusting unit 20 and transmitted through the polarizing plate 22 and then emitted from the synthetic laser beam generating unit 10. Therefore, the polarization angles of the laser beams R, G, and B included in the synthetic laser beam C coincide with each other. The synthetic laser beam C emitted from the synthetic laser beam generator 10 travels to the scanning unit 40.
温度検出部30は、液晶セル21の温度を検出するサーミスタから構成され、検出温度を示す温度データを後述する制御部300に供給する。温度検出部30は、液晶セル21の基板に設けられている。なお、温度検出部30は、液晶セル21に直接配置されるものに限られず、間接的に液晶セル21の温度を検出可能な位置にあってもよい。例えば、液晶セル21とは別体の基板に設けられても良い。また、温度検出部30は、赤外線輻射により温度を検出するものや、半導体式温度センサなどであってもよい。また、温度検出部30は、レーザー光の各色に対応する液晶セル21r,21g,21bに設けられ、液晶セル21r,21g,21b毎の温度を検出してもよい。
The temperature detection unit 30 includes a thermistor that detects the temperature of the liquid crystal cell 21, and supplies temperature data indicating the detection temperature to the control unit 300 described later. The temperature detection unit 30 is provided on the substrate of the liquid crystal cell 21. The temperature detection unit 30 is not limited to the one directly disposed on the liquid crystal cell 21 and may be located at a position where the temperature of the liquid crystal cell 21 can be indirectly detected. For example, the liquid crystal cell 21 may be provided on a separate substrate. The temperature detector 30 may be a device that detects temperature by infrared radiation, a semiconductor temperature sensor, or the like. Moreover, the temperature detection part 30 may be provided in the liquid crystal cells 21r, 21g, and 21b corresponding to each color of the laser light, and may detect the temperature for each of the liquid crystal cells 21r, 21g, and 21b.
走査部40は、MEMS(Micro Electro Mechanical System)スキャナ(MEMSミラー)からなり、合成レーザー光Cを走査して、透過スクリーン50に表示画像Mを生成する。また、走査部40は、自身が有する各ミラーを動かすピエゾ素子の時間ごとの振れ位置を検出する機能を有し、検出した位置を示す走査位置検出データを走査駆動部400に出力する。
The scanning unit 40 is composed of a MEMS (Micro Electro Mechanical System) scanner (MEMS mirror), scans the synthetic laser light C, and generates a display image M on the transmission screen 50. Further, the scanning unit 40 has a function of detecting a shake position for each piezo element that moves each mirror included in the scanning unit 40, and outputs scanning position detection data indicating the detected position to the scanning driving unit 400.
透過スクリーン50は、走査部40からの合成レーザー光Cを背面で受光し、透過拡散させることで、前面側に表示画像Mを表示する。透過スクリーン50は、ホログラフィックディフューザ、マイクロレンズアレイ、拡散板などから構成される。
The transmission screen 50 displays the display image M on the front side by receiving the synthesized laser beam C from the scanning unit 40 on the back side and transmitting and diffusing it. The transmission screen 50 includes a holographic diffuser, a microlens array, a diffusion plate, and the like.
図5に透過スクリーン50を走査部40側から見た場合における表示画像Mの一例を示す。表示画像Mは、同図に破線で示すように、走査部40が透過スクリーン50上に合成レーザー光Cを水平走査しながら垂直走査することで、生成される。走査部40によって描画される表示画像Mは、実際の走査可能範囲50aよりも小さく設定されている。特に、水平方向では、走査部40が有するミラーの反射面を共振によって振ることで走査するため、走査の往復の切り替わりポイント付近では、ミラーの動作速度が遅くなったり、停止したりする。このため、表示画像Mが生成される領域を、走査可能範囲50a全域に設定すると、表示画像Mに歪みが生じたり、解像度の低下が生じたりする。このような理由から、表示画像Mが生成される領域(表示エリア50b)は、走査可能範囲50aよりも小さく、走査の切り替わりポイント付近を含まない領域に設定されている。
FIG. 5 shows an example of the display image M when the transmission screen 50 is viewed from the scanning unit 40 side. The display image M is generated by the scanning unit 40 performing vertical scanning while horizontally scanning the synthetic laser light C on the transmission screen 50 as indicated by broken lines in FIG. The display image M drawn by the scanning unit 40 is set to be smaller than the actual scanable range 50a. In particular, in the horizontal direction, scanning is performed by shaking the reflection surface of the mirror included in the scanning unit 40 by resonance, so that the mirror operation speed is slowed down or stopped near the reciprocation switching point of scanning. For this reason, if the region where the display image M is generated is set to the entire scannable range 50a, the display image M is distorted or the resolution is lowered. For this reason, the area (display area 50b) where the display image M is generated is set to an area that is smaller than the scannable range 50a and does not include the vicinity of the scan switching point.
光強度検出部60は、レーザー光R,G,B各々の光強度A(レーザー光Rの光強度Ar、レーザー光Gの光強度Ag、レーザー光Bの光強度Ab)を検出し、検出した光強度Aを示す光強度データを後述する制御部300に供給する。光強度検出部60は、例えば、RGB各色の光学フィルタと3チャネルのフォトダイオードとを有するカラーセンサから構成されている。
光強度検出部60は、図2に示すように、透過スクリーン50の背面に設けられている。また、光強度検出部60は、図5に示すように、走査可能範囲50a内であって、表示エリア50bより外側の適宜の位置に設けられている。これにより、表示画像Mの走査に影響を及ぼすことなく、レーザー光R,G,Bの光強度が検出可能となっている。 Thelight intensity detector 60 detects and detects the light intensity A (the light intensity Ar of the laser light R, the light intensity Ag of the laser light G, and the light intensity Ab of the laser light B) of each of the laser lights R, G, and B. Light intensity data indicating the light intensity A is supplied to the control unit 300 described later. The light intensity detection unit 60 includes, for example, a color sensor having RGB color optical filters and a three-channel photodiode.
Thelight intensity detector 60 is provided on the back surface of the transmissive screen 50 as shown in FIG. Further, as shown in FIG. 5, the light intensity detector 60 is provided at an appropriate position within the scannable range 50a and outside the display area 50b. As a result, the light intensities of the laser beams R, G, and B can be detected without affecting the scanning of the display image M.
光強度検出部60は、図2に示すように、透過スクリーン50の背面に設けられている。また、光強度検出部60は、図5に示すように、走査可能範囲50a内であって、表示エリア50bより外側の適宜の位置に設けられている。これにより、表示画像Mの走査に影響を及ぼすことなく、レーザー光R,G,Bの光強度が検出可能となっている。 The
The
反射部70は、透過スクリーン50の前面に表示された表示画像Mが、所望の位置・大きさで、虚像Vとして結ばれるように、透過スクリーン50とウインドシールド3との間に設けられる光学系である。本実施形態に係る反射部70は、平面ミラー71と、拡大ミラー72とから構成されている。
The reflection unit 70 is an optical system provided between the transmission screen 50 and the windshield 3 so that the display image M displayed on the front surface of the transmission screen 50 is connected as a virtual image V at a desired position and size. It is. The reflection unit 70 according to this embodiment includes a plane mirror 71 and a magnifying mirror 72.
平面ミラー71は、透過スクリーン50に表示された表示画像Mを表す表示光Kを、拡大ミラー72に向けて反射させる。
The plane mirror 71 reflects the display light K representing the display image M displayed on the transmission screen 50 toward the magnifying mirror 72.
拡大ミラー72は、凹面鏡等からなり、平面ミラー71からの表示光Kを、凹面で反射させることで、表示光Kをウインドシールド3の方向に向けて反射させる。これにより、結ばれる虚像Vの大きさは、表示画像Mが拡大された大きさになる。
The magnifying mirror 72 is formed of a concave mirror or the like, and reflects the display light K toward the windshield 3 by reflecting the display light K from the flat mirror 71 on the concave surface. As a result, the size of the virtual image V to be connected becomes a size obtained by enlarging the display image M.
筐体80は、上記各部(合成レーザー光生成部10~反射部70)を収納するものであり、遮光性の部材により形成される。筐体80には、拡大ミラー72で反射した表示光Kを通過させる開口部が形成されている。この開口部に透光部81が設けられている。
The housing 80 accommodates the above-described parts (synthetic laser light generation part 10 to reflection part 70), and is formed of a light-shielding member. The housing 80 is formed with an opening through which the display light K reflected by the magnifying mirror 72 passes. A translucent part 81 is provided in the opening.
透光部81は、アクリル等の透光性樹脂からなり、拡大ミラー72からの表示光Kを透過させる。透光部81は、外光がユーザ4の方向へ反射しないように湾曲形状に形成されている。
The translucent part 81 is made of a translucent resin such as acrylic and transmits the display light K from the magnifying mirror 72. The translucent part 81 is formed in a curved shape so that external light is not reflected in the direction of the user 4.
外光強度検出部90は、例えばライトセンサからなり、外光強度(例えば、照度)を検出する。外光強度検出部90は、検出した外光強度を示す外光強度データを後述する制御部300に出力する。図2の例では、外光強度検出部90が、透光部81の内面に配設された例を示したが、必要な外光強度が検出できる位置であれば、設置場所は任意である。
The external light intensity detection unit 90 is composed of a light sensor, for example, and detects external light intensity (for example, illuminance). The outside light intensity detection unit 90 outputs outside light intensity data indicating the detected outside light intensity to the control unit 300 described later. In the example of FIG. 2, the example in which the external light intensity detection unit 90 is disposed on the inner surface of the translucent unit 81 is shown, but the installation location is arbitrary as long as the necessary external light intensity can be detected. .
次に、表示装置1の電気的構成について説明する。
Next, the electrical configuration of the display device 1 will be described.
表示装置1は、上記構成の他、図6に示すように、LD駆動部100と、液晶駆動部200と、制御部300と、走査駆動部400と、を備える。これらは、例えば、筐体80内に配設されたプリント回路板(図示せず)に実装されている。なお、これらを筐体80外部に設けてもよい。
In addition to the above configuration, the display device 1 includes an LD driving unit 100, a liquid crystal driving unit 200, a control unit 300, and a scanning driving unit 400, as shown in FIG. These are mounted on, for example, a printed circuit board (not shown) disposed in the housing 80. These may be provided outside the housing 80.
LD駆動部100は、ドライバIC(Integrated Circuit)等からなり、制御部300の制御の下で、LD11r、11g,11bの各々を、PAM(Pulse Amplitude Modulation)方式、及びPWM(Pulse Width Modulation)方式で駆動する。LD駆動部100は、制御部300から供給される電流制御データに応じて駆動電流をLD11r~11b各々に供給する。
The LD driving unit 100 includes a driver IC (IntegratedIntegrCircuit) or the like, and each of the LDs 11r, 11g, and 11b is controlled by the control unit 300 using a PAM (Pulse Amplitude Modulation) method and a PWM (Pulse Width Modulation) method. Drive with. The LD driving unit 100 supplies a driving current to each of the LDs 11r to 11b according to the current control data supplied from the control unit 300.
液晶駆動部200は、ドライバIC等からなり、制御部300の制御の下で、赤色用液晶セル21r、緑色用液晶セル21g、青色用液晶セル21bの各々を駆動する。液晶駆動部200は、CPU310から出力される各色用のPWM値(デューティ比を示すデータ)を取得し、取得したPWM値に応じた電圧を各色用液晶セル21r,21g,21bに印加し、駆動する。
The liquid crystal driving unit 200 includes a driver IC or the like, and drives each of the red liquid crystal cell 21r, the green liquid crystal cell 21g, and the blue liquid crystal cell 21b under the control of the control unit 300. The liquid crystal driving unit 200 acquires the PWM value (data indicating the duty ratio) for each color output from the CPU 310, applies a voltage corresponding to the acquired PWM value to the liquid crystal cells 21r, 21g, and 21b for each color, and drives it. To do.
走査駆動部400は、ドライバIC等からなり、制御部300の制御の下で、走査部40を駆動する。走査駆動部400は、走査部40を駆動させた後、走査部40が出力した走査位置検出データを取得し、取得した走査位置検出データに基づいてフィードバックデータを算出し、制御部300へ出力する。このフィードバックデータに基づいて、制御部300は、走査部40の現在の走査位置を特定可能となっている。
The scanning drive unit 400 includes a driver IC and the like, and drives the scanning unit 40 under the control of the control unit 300. The scanning drive unit 400 drives the scanning unit 40, acquires the scanning position detection data output from the scanning unit 40, calculates feedback data based on the acquired scanning position detection data, and outputs the feedback data to the control unit 300. . Based on this feedback data, the control unit 300 can specify the current scanning position of the scanning unit 40.
制御部300は、マイクロコントローラ、FPGA(Field Programmable Gate Array)、ASIC(Application Specific Integrated Circuit)等からなり、CPU310と、記憶部320と、を備える。
The control unit 300 includes a microcontroller, an FPGA (Field Programmable Gate Array), an ASIC (Application Specific Integrated Circuit), and the like, and includes a CPU 310 and a storage unit 320.
記憶部320は、ROM(Read Only Memory)、RAM(Random Access Memory)、フラッシュメモリ等からなり、表示装置1の動作に必要なプログラムや、各種データを記憶する。記憶部320には、後述する各処理(透過光ホワイトバランス調整処理、ホワイトバランス調整処理)の動作プログラムのデータや、液晶駆動用テーブルTA1(図8)、補正用テーブルTA2(図9)のデータなどが予め記憶されている。また、記憶部320は、CPU310の演算結果などの各種データを一時的に記憶する。
The storage unit 320 includes a ROM (Read Only Memory), a RAM (Random Access Memory), a flash memory, and the like, and stores programs and various data necessary for the operation of the display device 1. The storage unit 320 stores operation program data for each process (transmitted light white balance adjustment process and white balance adjustment process) described later, and data for the liquid crystal drive table TA1 (FIG. 8) and correction table TA2 (FIG. 9). Etc. are stored in advance. The storage unit 320 temporarily stores various data such as the calculation result of the CPU 310.
CPU310は、記憶部320からプログラムを読み出し、実行することで各部を制御する。CPU310には、車両2のECU(Electronic Control Unit)5から表示画像Mを表示するための画像データがLVDS(Low Voltage Differential Signal)通信等によって供給される。なお、画像データの少なくとも一部は、記憶部320に予め記憶されていてもよい。CPU310は、この画像データに従い、LD駆動部100を介してレーザー光出射部11を制御すると共に、走査駆動部400を介して走査部40を制御することにより、画像データが要求する表示画像Mを透過スクリーン50上に生成する。これにより、表示画像Mを表す表示光Kがウインドシールド3に向けて出射され、ユーザ4は、表示画像Mを虚像Vとして視認することができる。
また、CPU310は、走査駆動部400から供給されるフィードバックデータに基づいて、透過スクリーン50上における現在の合成レーザー光Cの走査位置を特定する。そして、走査位置が光強度検出部60の位置が重なったタイミングで、LD駆動部100を介してレーザー光出射部11を駆動する。このときに光強度検出部60が検出したレーザー光R,G,Bの色毎の光強度(Ar,Ag,Ab)をCPU310は取得する。 TheCPU 310 controls each unit by reading a program from the storage unit 320 and executing the program. Image data for displaying the display image M from an ECU (Electronic Control Unit) 5 of the vehicle 2 is supplied to the CPU 310 by LVDS (Low Voltage Differential Signal) communication or the like. Note that at least a part of the image data may be stored in the storage unit 320 in advance. In accordance with the image data, the CPU 310 controls the laser light emitting unit 11 through the LD driving unit 100 and also controls the scanning unit 40 through the scanning driving unit 400, thereby displaying the display image M requested by the image data. It is generated on the transmission screen 50. Thereby, the display light K representing the display image M is emitted toward the windshield 3, and the user 4 can visually recognize the display image M as the virtual image V.
Further, theCPU 310 specifies the current scanning position of the synthetic laser light C on the transmission screen 50 based on the feedback data supplied from the scanning driving unit 400. Then, the laser beam emitting unit 11 is driven via the LD driving unit 100 at the timing when the scanning position overlaps the position of the light intensity detecting unit 60. At this time, the CPU 310 acquires the light intensity (Ar, Ag, Ab) for each color of the laser beams R, G, B detected by the light intensity detector 60.
また、CPU310は、走査駆動部400から供給されるフィードバックデータに基づいて、透過スクリーン50上における現在の合成レーザー光Cの走査位置を特定する。そして、走査位置が光強度検出部60の位置が重なったタイミングで、LD駆動部100を介してレーザー光出射部11を駆動する。このときに光強度検出部60が検出したレーザー光R,G,Bの色毎の光強度(Ar,Ag,Ab)をCPU310は取得する。 The
Further, the
ここからは、上記構成を有する表示装置1の動作を説明する。表示装置1は、例えば車両2の起動スイッチがオン(イグニッション(IGN)もしくはアクセサリーポジション(ACC)がオン)されたことに応じて起動し、種々の動作を行う。表示装置1は、透過スクリーン50の表示エリア50bに表示画像Mを表示するといった一般的な動作を行うことが可能であるが、本実施形態に特有の動作を以下に説明する。
From here, the operation of the display device 1 having the above configuration will be described. The display device 1 is activated, for example, in response to the activation switch of the vehicle 2 being turned on (ignition (IGN) or accessory position (ACC) is turned on), and performs various operations. The display device 1 can perform a general operation such as displaying the display image M in the display area 50b of the transmissive screen 50. The operation unique to the present embodiment will be described below.
本実施形態に係る表示装置1は、特有の動作として、表示画像Mのホワイトバランスの調整を二回実行する。以下では、説明の理解を容易にするため、二回のホワイトバランスの調整のうち、透過光調整部20で調整されるホワイトバランスを「透過光ホワイトバランス」と呼ぶことにする。
まず、図7~図10を参照して、透過光ホワイトバランスを調整する透過光ホワイトバランス調整処理を説明する。 Thedisplay device 1 according to the present embodiment performs white balance adjustment of the display image M twice as a specific operation. Hereinafter, in order to facilitate understanding of the description, the white balance adjusted by the transmitted light adjusting unit 20 out of the two white balance adjustments is referred to as “transmitted light white balance”.
First, the transmitted light white balance adjustment process for adjusting the transmitted light white balance will be described with reference to FIGS.
まず、図7~図10を参照して、透過光ホワイトバランスを調整する透過光ホワイトバランス調整処理を説明する。 The
First, the transmitted light white balance adjustment process for adjusting the transmitted light white balance will be described with reference to FIGS.
(透過光ホワイトバランス調整処理)
表示装置1が起動すると、CPU310は、図7に示す透過光ホワイトバランス調整処理を開始し、まず、外光強度検出部90から供給される外光強度データが示す外光強度を取得する(ステップA1)。 (Transmission light white balance adjustment processing)
When thedisplay device 1 is activated, the CPU 310 starts the transmitted light white balance adjustment process shown in FIG. 7, and first acquires the external light intensity indicated by the external light intensity data supplied from the external light intensity detector 90 (step). A1).
表示装置1が起動すると、CPU310は、図7に示す透過光ホワイトバランス調整処理を開始し、まず、外光強度検出部90から供給される外光強度データが示す外光強度を取得する(ステップA1)。 (Transmission light white balance adjustment processing)
When the
続いて、CPU310は、取得した外光強度Pと、予め記憶部320に格納された液晶駆動用テーブルTA1(図8参照)とに基づいて、液晶セル21を駆動するためのPWM値(デューティ比を示す値)を算出する(ステップA2)。
Subsequently, the CPU 310 performs a PWM value (duty ratio) for driving the liquid crystal cell 21 based on the acquired external light intensity P and the liquid crystal driving table TA1 (see FIG. 8) stored in the storage unit 320 in advance. Is calculated) (step A2).
液晶駆動用テーブルTA1は、図8に示すように、外光強度Pと、液晶セル21r,21g,21bの各々を駆動するためのPWM値Dr,Dg,Dbとが対応付けられたデータである。同図において、P0は外光強度Pの最小値を表し、Pk(kは正の整数)は外光強度Pの最大値を表す。また、jは、0以上k-1以下(0≦j≦k-1)の整数であり、Pj+1はPjよりも大きい(Pj+1>Pj)。また、各PWM値Dr,Dg,Dbのインデックスは外光強度Pのインデックスに対応する。
As shown in FIG. 8, the liquid crystal drive table TA1 is data in which the external light intensity P is associated with the PWM values Dr, Dg, Db for driving the liquid crystal cells 21r, 21g, 21b. . In the figure, P0 represents the minimum value of the external light intensity P, and Pk (k is a positive integer) represents the maximum value of the external light intensity P. Further, j is an integer of 0 or more and k−1 or less (0 ≦ j ≦ k−1), and Pj + 1 is larger than Pj (Pj + 1> Pj). Further, the index of each PWM value Dr, Dg, Db corresponds to the index of the external light intensity P.
ここで、赤色用液晶セル21rについて説明すると、外光強度PがPj以上Pj+1以下(Pj≦P≦Pj+1)の値であった場合、CPU310は、液晶駆動用テーブルTA1を参照し、Dr_jとDr_j+1とを取得する。そして、CPU310は、下記(数1)に示す(1)式によって、赤色用液晶セル21rを駆動するためのPWM値Drを線形補間法により算出する。
同様に、CPU310は、下記(数1)に示す(2)式によって、緑色用液晶セル21gを駆動するためのPWM値Dgを算出する。また、CPU310は、下記(数1)に示す(3)式によって、青色用液晶セル21bを駆動するためのPWM値Dbを算出する。 Here, the redliquid crystal cell 21r will be described. When the external light intensity P is a value not less than Pj and not more than Pj + 1 (Pj ≦ P ≦ Pj + 1), the CPU 310 refers to the liquid crystal driving table TA1, and Dr_j and Dr_j + 1. And get. Then, the CPU 310 calculates the PWM value Dr for driving the red liquid crystal cell 21r by the linear interpolation method using the equation (1) shown below (Equation 1).
Similarly, theCPU 310 calculates a PWM value Dg for driving the green liquid crystal cell 21g according to equation (2) shown in the following (Equation 1). Further, the CPU 310 calculates the PWM value Db for driving the blue liquid crystal cell 21b by the following equation (3) shown in (Equation 1).
同様に、CPU310は、下記(数1)に示す(2)式によって、緑色用液晶セル21gを駆動するためのPWM値Dgを算出する。また、CPU310は、下記(数1)に示す(3)式によって、青色用液晶セル21bを駆動するためのPWM値Dbを算出する。 Here, the red
Similarly, the
なお、液晶駆動用テーブルTA1において、同一の外光強度Pにおける各液晶セルのPWM値Dr,Dg,Dbは、透過光調整部20を透過光後の各レーザー光R,G,Bの光強度の比が、理想混色比となるように設定されている。理想混色比とは、白色になるための任意のxy色度となるレーザー光Rとレーザー光Gとレーザー光Bとの光強度比である。これにより、透過光調整部20を透過した後のレーザー光R,G,Bは、ホワイトバランスが調整されたものとなる。
In the liquid crystal driving table TA1, the PWM values Dr, Dg, Db of the liquid crystal cells at the same external light intensity P are the light intensities of the laser lights R, G, B after the light transmitted through the transmitted light adjusting unit 20. Is set to be an ideal color mixture ratio. The ideal color mixture ratio is a light intensity ratio of the laser light R, the laser light G, and the laser light B that has an arbitrary xy chromaticity for becoming white. As a result, the laser beams R, G, and B that have passed through the transmitted light adjusting unit 20 have their white balance adjusted.
続いて、CPU310は、温度検出部30から供給される温度データが示す検出温度を取得する(ステップA3)。
Subsequently, the CPU 310 acquires the detected temperature indicated by the temperature data supplied from the temperature detection unit 30 (step A3).
続いて、CPU310は、取得した検出温度Tと、予め記憶部320に格納された補正用テーブルTA2(図9参照)とに基づいて、温度変化による液晶セル21の透過率変動を考慮してLD11r,11g,11bを駆動するための補正係数を算出する(ステップA4)。
Subsequently, the CPU 310 considers the transmittance variation of the liquid crystal cell 21 due to the temperature change based on the acquired detected temperature T and the correction table TA2 (see FIG. 9) stored in the storage unit 320 in advance. , 11g and 11b are calculated (step A4).
補正用テーブルTA2は、図9に示すように、外光強度Pと、液晶セル21r,21g,21bの各々に対応する補正係数Cr,Cg,Cbと、が対応付けられたデータである。同図において、T0は、表示装置1の使用環境を考慮して想定される温度範囲の最小値(例えば、-40℃)を表し、Tn(nは正の整数)は温度範囲の最大値(例えば、+85℃)を表す。また、mは、0以上n-1以下(0≦m≦n-1)の整数であり、Pm+1はPmよりも大きい(Pm+1>Pm)。また、Pm+1とPmとは、5℃間隔、10℃間隔などの適宜の間隔に設定されている。各補正係数Cr,Cg,Cbのインデックスは検出温度Tのインデックスに対応する。
As shown in FIG. 9, the correction table TA2 is data in which the external light intensity P and the correction coefficients Cr, Cg, and Cb corresponding to the liquid crystal cells 21r, 21g, and 21b are associated with each other. In the figure, T0 represents the minimum value (for example, −40 ° C.) of the temperature range assumed in consideration of the use environment of the display device 1, and Tn (n is a positive integer) is the maximum value of the temperature range ( For example, + 85 ° C.). M is an integer of 0 or more and n-1 or less (0 ≦ m ≦ n−1), and Pm + 1 is larger than Pm (Pm + 1> Pm). Further, Pm + 1 and Pm are set to appropriate intervals such as a 5 ° C. interval and a 10 ° C. interval. The index of each correction coefficient Cr, Cg, Cb corresponds to the index of the detected temperature T.
ここで、赤色用液晶セル21rについて説明すると、検出温度TがTm以上Tm+1以下(Pm≦P≦Pm+1)の値であった場合、CPU310は、補正用テーブルTA2を参照し、Cr_mとCr_m+1とを取得する。そして、CPU310は、下記(数2)に示す(4)式によって、温度変化による赤色用液晶セル21rの透過率変動を考慮してLD11rを駆動するための補正係数Crを線形補間法により算出する。
同様に、CPU310は、下記(数2)に示す(5)式によって、温度変化による緑色用液晶セル21gの透過率変動を考慮してLD11gを駆動するための補正係数Cgを算出する。また、CPU310は、下記(数2)に示す(6)式によって、温度変化による緑色用液晶セル21gの透過率変動を考慮してLD11gを駆動するための補正係数Cgを算出する。 Here, the redliquid crystal cell 21r will be described. When the detected temperature T is a value not less than Tm and not more than Tm + 1 (Pm ≦ P ≦ Pm + 1), the CPU 310 refers to the correction table TA2 and determines Cr_m and Cr_m + 1. get. Then, the CPU 310 calculates a correction coefficient Cr for driving the LD 11r by a linear interpolation method in consideration of the transmittance variation of the red liquid crystal cell 21r due to a temperature change, according to the equation (4) shown below (Equation 2). .
Similarly, theCPU 310 calculates the correction coefficient Cg for driving the LD 11g in consideration of the transmittance variation of the green liquid crystal cell 21g due to the temperature change, by the equation (5) shown in the following (Equation 2). In addition, the CPU 310 calculates a correction coefficient Cg for driving the LD 11g in consideration of the transmittance variation of the green liquid crystal cell 21g due to a temperature change, according to Equation (6) shown in the following (Equation 2).
同様に、CPU310は、下記(数2)に示す(5)式によって、温度変化による緑色用液晶セル21gの透過率変動を考慮してLD11gを駆動するための補正係数Cgを算出する。また、CPU310は、下記(数2)に示す(6)式によって、温度変化による緑色用液晶セル21gの透過率変動を考慮してLD11gを駆動するための補正係数Cgを算出する。 Here, the red
Similarly, the
続いて、CPU310は、ステップA4で算出した補正係数Cr,Cg,Cbを基に、補正PWM値を算出する(ステップA5)。具体的には、補正係数をステップA2で算出したPWM値に乗算して、液晶セル21r,21g,21bの各々に対応する補正PWM値として、Cr・Dr,Cg・Dg,Cb・Dbを算出する。
Subsequently, the CPU 310 calculates a correction PWM value based on the correction coefficients Cr, Cg, and Cb calculated in step A4 (step A5). Specifically, the PWM value calculated in step A2 is multiplied by the correction coefficient to calculate Cr · Dr, Cg · Dg, and Cb · Db as the corrected PWM values corresponding to each of the liquid crystal cells 21r, 21g, and 21b. To do.
続いて、CPU310は、液晶駆動部200に算出した補正PWM値を出力する(ステップA6)。具体的には、CPU310は、液晶駆動部200に補正PWM値Cr・Drを出力することで液晶セル21rを駆動する。また、CPU310は、液晶駆動部200に補正PWM値Cg・Dgを出力することで液晶セル21gを駆動する。また、CPU310は、液晶駆動部200に補正PWM値Cb・Dbを出力することで液晶セル21bを駆動する。
Subsequently, the CPU 310 outputs the calculated PWM value to the liquid crystal driving unit 200 (step A6). Specifically, the CPU 310 outputs the corrected PWM value Cr · Dr to the liquid crystal driving unit 200 to drive the liquid crystal cell 21r. Further, the CPU 310 drives the liquid crystal cell 21g by outputting the corrected PWM value Cg · Dg to the liquid crystal driving unit 200. Further, the CPU 310 drives the liquid crystal cell 21 b by outputting the corrected PWM value Cb · Db to the liquid crystal driving unit 200.
ここで、図10に、図9の補正用テーブルT2における検出温度Tと補正係数Cr,Cg,Cbとの関係をグラフ化したものを示す。図10中、○でプロットされた点における縦軸の値が補正係数Cr、□でプロットされた点における縦軸の値が補正係数Cg、△でプロットされた点における縦軸の値が補正係数Cbである。図10を参照すると、同じ検出温度Tにおける補正係数Cr,Cr,Cbが異なることがわかる。本実施形態では、このように液晶セル21r,21g,21bの温度変化による透過率変動を考慮した補正係数を、液晶セル毎に設けたことで、高精度なホワイトバランス調整が可能となっている。これにより、ホワイトバランスが調整されたレーザー光R,G,Bが透過光調整部20から出射されることになる。
Here, FIG. 10 shows a graph of the relationship between the detected temperature T and the correction coefficients Cr, Cg, Cb in the correction table T2 of FIG. In FIG. 10, the value on the vertical axis at the point plotted with ◯ is the correction coefficient Cr, the value on the vertical axis at the point plotted with □ is the correction coefficient Cg, and the value on the vertical axis at the point plotted with Δ is the correction coefficient. Cb. Referring to FIG. 10, it can be seen that the correction coefficients Cr, Cr, and Cb at the same detected temperature T are different. In this embodiment, white balance adjustment with high accuracy is possible by providing a correction coefficient for each liquid crystal cell in consideration of transmittance variation due to temperature changes of the liquid crystal cells 21r, 21g, and 21b. . As a result, the laser beams R, G, and B whose white balance has been adjusted are emitted from the transmitted light adjusting unit 20.
CPU310は、以上の処理からなる透過光ホワイトバランス調整処理を、例えば表示装置1の電源がオフされるまで、繰り返し実行する。
The CPU 310 repeatedly executes the transmitted light white balance adjustment processing including the above processing until the power of the display device 1 is turned off, for example.
次に、透過光調整部20を透過して透過光ホワイトバランスが調整されたレーザー光R,G,Bの光強度を光強度検出部60で検出し、さらに表示画像Mのホワイトバランスを調整するホワイトバランス調整処理を、図11、図12を参照して説明する。このように透過光調整部20を透過した後のレーザー光R,G,Bにおいてもホワイトバランスを調整することによって、より高精度でホワイトバランスが調整される。
Next, the light intensity of the laser beams R, G, and B that have been transmitted through the transmitted light adjusting unit 20 and whose transmitted light white balance has been adjusted is detected by the light intensity detecting unit 60, and the white balance of the display image M is adjusted. The white balance adjustment process will be described with reference to FIGS. As described above, the white balance is adjusted with higher accuracy by adjusting the white balance in the laser beams R, G, and B after passing through the transmitted light adjusting unit 20.
(ホワイトバランス調整処理)
表示装置1が起動すると、CPU310は、図11に示すホワイトバランスを開始し、まず、光強度検出部60から供給される光強度データが示す光強度を取得する(ステップB1)。
具体的には、CPU310は、走査駆動部400から供給されるフィードバックデータに基づいて、透過スクリーン50上における現在の合成レーザー光Cの走査位置を特定する。そして、走査位置が光強度検出部60の位置が重なったタイミングで、LD駆動部100を介してレーザー光出射部11を駆動する。このときに光強度検出部60が検出したレーザー光R,G,Bの色毎の光強度(Ar,Ag,Ab)をCPU310は取得する。 (White balance adjustment processing)
When thedisplay device 1 is activated, the CPU 310 starts white balance shown in FIG. 11, and first acquires the light intensity indicated by the light intensity data supplied from the light intensity detector 60 (step B1).
Specifically, theCPU 310 specifies the current scanning position of the combined laser light C on the transmission screen 50 based on the feedback data supplied from the scanning driving unit 400. Then, the laser beam emitting unit 11 is driven via the LD driving unit 100 at the timing when the scanning position overlaps the position of the light intensity detecting unit 60. At this time, the CPU 310 acquires the light intensity (Ar, Ag, Ab) for each color of the laser beams R, G, B detected by the light intensity detector 60.
表示装置1が起動すると、CPU310は、図11に示すホワイトバランスを開始し、まず、光強度検出部60から供給される光強度データが示す光強度を取得する(ステップB1)。
具体的には、CPU310は、走査駆動部400から供給されるフィードバックデータに基づいて、透過スクリーン50上における現在の合成レーザー光Cの走査位置を特定する。そして、走査位置が光強度検出部60の位置が重なったタイミングで、LD駆動部100を介してレーザー光出射部11を駆動する。このときに光強度検出部60が検出したレーザー光R,G,Bの色毎の光強度(Ar,Ag,Ab)をCPU310は取得する。 (White balance adjustment processing)
When the
Specifically, the
続いて、CPU310は、取得した光強度と、予め記憶部320にデータとして記憶された理想混色比とに基づいて、両者間のズレを考慮した補正係数を算出する(ステップB2)。理想混色比とは、白色になるための任意のxy色度となるレーザー光Rとレーザー光Gとレーザー光Bとの光強度比である。ここで、各レーザー光R,G,Bの光強度をLr,Lg,Lbとすれば、例えば、理想混色比は、Lr:Lg:Lb=3.0:2.5:1である。
Subsequently, based on the acquired light intensity and the ideal color mixture ratio previously stored as data in the storage unit 320, the CPU 310 calculates a correction coefficient that takes into account the deviation between the two (step B2). The ideal color mixture ratio is a light intensity ratio of the laser light R, the laser light G, and the laser light B that has an arbitrary xy chromaticity for becoming white. Here, assuming that the light intensities of the laser beams R, G, and B are Lr, Lg, and Lb, for example, the ideal color mixture ratio is Lr: Lg: Lb = 3.0: 2.5: 1.
ここで、図12に、各LD11r,11g,11bの駆動電流と光強度との関係を示すグラフを示す。同図において、符号6rで示すグラフがLD11rに対応し、符号6gで示すグラフがLD11gに対応し、符号6bで示すグラフがLD11bに対応する。また、同図で、理想混色比となる理想光強度Lr,Lg,Lbと、光強度検出部60から取得した光強度Ar,Ag,Abとがズレた例を示す。
Here, FIG. 12 shows a graph showing the relationship between the drive current of each of the LDs 11r, 11g, and 11b and the light intensity. In the figure, the graph indicated by reference numeral 6r corresponds to the LD 11r, the graph indicated by reference numeral 6g corresponds to the LD 11g, and the graph indicated by reference numeral 6b corresponds to the LD 11b. In addition, the figure shows an example in which the ideal light intensities Lr, Lg, and Lb that are the ideal color mixture ratio and the light intensities Ar, Ag, and Ab acquired from the light intensity detector 60 are shifted.
図12で、取得した光強度Arに着目すると、理想混色比になる光強度Lrよりも現在の光強度Arが大きくなってしまっていることがわかる。この場合は、CPU310は、例えば、理想光強度を取得した光強度で除することにより、補正係数としてLr/Ar(図12の例ではLr/Ar<1)を算出する。
また、取得した光強度Agに着目すると、理想混色比になる光強度Lgよりも現在の光強度Arが小さくなってしまっていることがわかる。この場合は、CPU310は、例えば、理想光強度を取得した光強度で除することにより、補正係数としてLg/Ag(図12の例ではLg/Ag>1)を算出する。また、同様に、取得した光強度Abに着目すると、CPU310は、例えば、補正係数としてLb/Ab(図12の例ではLb/Ab>1)を算出する。 In FIG. 12, when attention is paid to the acquired light intensity Ar, it can be seen that the current light intensity Ar is larger than the light intensity Lr at which the ideal color mixture ratio is obtained. In this case, for example, theCPU 310 calculates Lr / Ar (Lr / Ar <1 in the example of FIG. 12) as a correction coefficient by dividing the ideal light intensity by the acquired light intensity.
Further, when attention is paid to the acquired light intensity Ag, it can be seen that the current light intensity Ar is smaller than the light intensity Lg at which the ideal color mixture ratio is obtained. In this case, for example, theCPU 310 calculates Lg / Ag (Lg / Ag> 1 in the example of FIG. 12) as a correction coefficient by dividing the ideal light intensity by the acquired light intensity. Similarly, when focusing on the acquired light intensity Ab, the CPU 310 calculates, for example, Lb / Ab (Lb / Ab> 1 in the example of FIG. 12) as a correction coefficient.
また、取得した光強度Agに着目すると、理想混色比になる光強度Lgよりも現在の光強度Arが小さくなってしまっていることがわかる。この場合は、CPU310は、例えば、理想光強度を取得した光強度で除することにより、補正係数としてLg/Ag(図12の例ではLg/Ag>1)を算出する。また、同様に、取得した光強度Abに着目すると、CPU310は、例えば、補正係数としてLb/Ab(図12の例ではLb/Ab>1)を算出する。 In FIG. 12, when attention is paid to the acquired light intensity Ar, it can be seen that the current light intensity Ar is larger than the light intensity Lr at which the ideal color mixture ratio is obtained. In this case, for example, the
Further, when attention is paid to the acquired light intensity Ag, it can be seen that the current light intensity Ar is smaller than the light intensity Lg at which the ideal color mixture ratio is obtained. In this case, for example, the
続いて、CPU310は、算出した補正係数を反映してLD11r,11g,11bを駆動する(ステップB3)。例えば、CPU310は、PAM制御の場合は電流値に補正係数を乗算し、PWM制御の場合はPWM値(デューティ比)に補正係数を乗算することにより、LD制御部100に供給する電流制御データを補正する。そして、補正した電流制御データをLD駆動部100に出力して、LD11r,11g,11bを駆動する。
Subsequently, the CPU 310 drives the LDs 11r, 11g, and 11b by reflecting the calculated correction coefficient (step B3). For example, in the case of PAM control, the CPU 310 multiplies the current value by a correction coefficient, and in the case of PWM control, multiplies the PWM value (duty ratio) by the correction coefficient to obtain current control data to be supplied to the LD control unit 100. to correct. Then, the corrected current control data is output to the LD driving unit 100 to drive the LDs 11r, 11g, and 11b.
ここで、図12を例にし、補正前の電流制御データによりLD11rに供給される駆動電流をIrとすれば、ステップB3で補正された電流制御データによりLD11rに供給される駆動電流は、(Lr/Ar)・Irとなる。同図からわかるように、LDの駆動電流と光強度との関係は線形性を有しているため、駆動電流に補正係数を加味すると、理想光強度LrでLD11rを発光させることができる。同様に、LD11g,11bについても理想光強度Lg,Lbで発光させることができる。
このように、LD制御部100に供給する電流制御データを補正することにより、LD11r,11g,11bの各々への駆動電流を調整して、各LDを理想光強度Lr,Lg,Lbで発光させることができる。これにより、表示画像Mのホワイトバランスが高精度で調整される。 Here, taking FIG. 12 as an example, if the drive current supplied to theLD 11r by the current control data before correction is Ir, the drive current supplied to the LD 11r by the current control data corrected in step B3 is (Lr / Ar) · Ir. As can be seen from the figure, since the relationship between the LD drive current and the light intensity is linear, the LD 11r can emit light with the ideal light intensity Lr when a correction coefficient is added to the drive current. Similarly, the LDs 11g and 11b can emit light with ideal light intensities Lg and Lb.
Thus, by correcting the current control data supplied to theLD control unit 100, the drive current to each of the LDs 11r, 11g, and 11b is adjusted, and each LD is caused to emit light with the ideal light intensities Lr, Lg, and Lb. be able to. Thereby, the white balance of the display image M is adjusted with high accuracy.
このように、LD制御部100に供給する電流制御データを補正することにより、LD11r,11g,11bの各々への駆動電流を調整して、各LDを理想光強度Lr,Lg,Lbで発光させることができる。これにより、表示画像Mのホワイトバランスが高精度で調整される。 Here, taking FIG. 12 as an example, if the drive current supplied to the
Thus, by correcting the current control data supplied to the
なお、電流制御データの補正は、各LD11r,11g,11bの最大出力(最大階調)においてなされることが好ましい。このようにすれば、光強度検出部60が取得する光強度Aが大きくなり、実際の光強度Aに対するノイズの比を最小にすることができる(つまり、S/N比(Signal-Noise ratio)を大きくして良好にすることができる)。そのため、高精度な光強度検出に伴って高精度なホワイトバランス調整が可能となる。また、各LD11r,11g,11bの最大出力は各LD11r,11g,11bの最大階調に相当するため、このようにすれば、最大階調における白表示のみならず、最大階調以下の任意の階調(即ちグレースケール)における白表示に対しても高精度なホワイトバランスを反映することができる。
It should be noted that the current control data is preferably corrected at the maximum output (maximum gradation) of each of the LDs 11r, 11g, and 11b. In this way, the light intensity A acquired by the light intensity detector 60 can be increased, and the ratio of noise to the actual light intensity A can be minimized (that is, the S / N ratio (Signal-Noise ratio)). Can be increased and improved). Therefore, it is possible to adjust the white balance with high accuracy as the light intensity is detected with high accuracy. In addition, since the maximum output of each of the LDs 11r, 11g, and 11b corresponds to the maximum gradation of each of the LDs 11r, 11g, and 11b, in this way, not only white display at the maximum gradation but also any arbitrary value below the maximum gradation. High-accuracy white balance can be reflected in white display in gradation (that is, gray scale).
また、ステップB3では、算出した補正係数を各LD11r,11g,11bへの駆動電流に反映したが、ECU5から供給される(または予め記憶部320に記憶されている)画像データに補正係数を反映してもよい。画像データは、1ピクセルにおいてR,G,B各色につき例えば8bitのデータで構成されるが、この8bitのデータに対して、ステップB2で算出した補正係数を乗算するなどにより、現在の光強度比と理想混色比とのずれを補正するようにしてもよい。このように、LD11r,11g,11bの駆動電流を補正せずに、画像データを直接補正することで、ホワイトバランスを調整してもよい。
In step B3, the calculated correction coefficient is reflected in the drive current to each of the LDs 11r, 11g, and 11b. However, the correction coefficient is reflected in the image data supplied from the ECU 5 (or stored in the storage unit 320 in advance). May be. The image data is composed of, for example, 8-bit data for each color of R, G, and B in one pixel. By multiplying the 8-bit data by the correction coefficient calculated in step B2, the current light intensity ratio is obtained. And the ideal color mixture ratio may be corrected. As described above, the white balance may be adjusted by directly correcting the image data without correcting the drive currents of the LDs 11r, 11g, and 11b.
CPU310は、以上の処理からなるホワイトバランス調整処理を、例えば表示装置1の電源がオフされるまで、繰り返し実行する。なお、CPU310は、以上に説明した透過光ホワイトバランス調整処理、及びホワイトバランス調整処理のフローを数百msec間隔で実行する。これにより、ユーザ4に違和感を与えない調光制御と高精度な調色制御が可能となる。
The CPU 310 repeatedly executes the white balance adjustment process including the above processes until, for example, the display device 1 is turned off. The CPU 310 executes the flow of the transmitted light white balance adjustment process and the white balance adjustment process described above at intervals of several hundred msec. As a result, light control that does not give the user 4 a sense of incongruity and highly accurate color control can be performed.
以上の実施形態では、透過光調整部20により透過光ホワイトバランス調整を行い、透過光調整部20を透過後のレーザー光R,G,Bにおいてもホワイトバランス調整を行う例を示した。
以下では、透過光調整部20に入射する前のレーザー光R,G,Bにおいてホワイトバランスの調整を行う変形例1に係る表示装置201と、変形例2に係る表示装置301とを、順に説明する。なお、以下では、説明の理解を容易にするため、以上の実施形態と異なる点を主に説明する。 In the above embodiment, the transmitted light white balance adjustment is performed by the transmittedlight adjusting unit 20, and the white balance adjustment is also performed for the laser beams R, G, and B after passing through the transmitted light adjusting unit 20.
Hereinafter, thedisplay device 201 according to the first modification that performs white balance adjustment in the laser beams R, G, and B before entering the transmitted light adjusting unit 20 and the display device 301 according to the second modification will be described in order. To do. In the following, in order to facilitate understanding of the description, differences from the above embodiment will be mainly described.
以下では、透過光調整部20に入射する前のレーザー光R,G,Bにおいてホワイトバランスの調整を行う変形例1に係る表示装置201と、変形例2に係る表示装置301とを、順に説明する。なお、以下では、説明の理解を容易にするため、以上の実施形態と異なる点を主に説明する。 In the above embodiment, the transmitted light white balance adjustment is performed by the transmitted
Hereinafter, the
(変形例1)
図13(a)に示すように、変形例1に係る表示装置201においては、透過スクリーン50aの背面に光強度検出部60が設けられていない。
その代わりに、図13(b)に示すように、表示装置201は、LD11rと集光レンズ12rとの間に配設され、レーザー光Rの光強度を検出する赤色用光強度検出部260rと、LD11gと集光レンズ12gとの間に配設され、レーザー光Gの光強度を検出する緑色用光強度検出部260gと、LD11bと集光レンズ12bとの間に配設され、レーザー光Bの光強度を検出する青色用光強度検出部260bと、を備える。 (Modification 1)
As shown in FIG. 13A, in thedisplay device 201 according to the first modification, the light intensity detection unit 60 is not provided on the back surface of the transmission screen 50a.
Instead, as shown in FIG. 13B, thedisplay device 201 is disposed between the LD 11r and the condensing lens 12r, and a red light intensity detector 260r that detects the light intensity of the laser light R. , Disposed between the LD 11g and the condensing lens 12g, disposed between the LD 11b and the condensing lens 12b, and the green light intensity detecting portion 260g for detecting the light intensity of the laser light G. And a blue light intensity detector 260b for detecting the light intensity of the light source.
図13(a)に示すように、変形例1に係る表示装置201においては、透過スクリーン50aの背面に光強度検出部60が設けられていない。
その代わりに、図13(b)に示すように、表示装置201は、LD11rと集光レンズ12rとの間に配設され、レーザー光Rの光強度を検出する赤色用光強度検出部260rと、LD11gと集光レンズ12gとの間に配設され、レーザー光Gの光強度を検出する緑色用光強度検出部260gと、LD11bと集光レンズ12bとの間に配設され、レーザー光Bの光強度を検出する青色用光強度検出部260bと、を備える。 (Modification 1)
As shown in FIG. 13A, in the
Instead, as shown in FIG. 13B, the
各色用光強度検出部260r,260g,260bは、各々、フォトダイオードなどからなる。赤色用光強度検出部260rは、レーザー光Rの光強度ArをCPU310に出力する。緑色用光強度検出部260gは、レーザー光Gの光強度AgをCPU310に出力する。青色用光強度検出部260bは、レーザー光Rの光強度AbをCPU310に出力する。なお、赤色用光強度検出部260rは、集光レンズ12rと液晶セル21との間に配設されていてもよい。緑色用、青色用光強度検出部260g,260bについても同様である。
Each light intensity detector 260r, 260g, 260b for each color includes a photodiode or the like. The red light intensity detector 260r outputs the light intensity Ar of the laser light R to the CPU 310. The green light intensity detection unit 260 g outputs the light intensity Ag of the laser light G to the CPU 310. The blue light intensity detection unit 260 b outputs the light intensity Ab of the laser light R to the CPU 310. The red light intensity detector 260r may be disposed between the condenser lens 12r and the liquid crystal cell 21. The same applies to the green and blue light intensity detectors 260g and 260b.
このように構成される変形例1に係る表示装置201では、CPU310は、各色用光強度検出部260r,260g,260bから取得した光強度Ar,Ag,Abを基に、図11に示すホワイトバランス調整処理を実行する。つまり、上記実施形態と変形例1とでは、センシングするレーザー光が透過光調整部20を透過後の光か、透過前の光かという点で異なっている。
そして、図11に示すホワイトバランス調整処理で調整されたレーザー光R,G,Bが透過光調整部20に入射し、この入射光に対して、CPU310は、図7に示す透過光ホワイトバランス調整処理を実行する。この変形例1のように、透過光調整部20に入射する前のレーザー光R,G,Bに対して、予めホワイトバランス調整を行っても良い。 In thedisplay device 201 according to the modified example 1 configured as described above, the CPU 310 performs the white balance shown in FIG. 11 based on the light intensities Ar, Ag, and Ab acquired from the light intensity detectors 260r, 260g, and 260b for each color. Execute the adjustment process. That is, the embodiment and the modification 1 are different in that the laser beam to be sensed is light after being transmitted through the transmitted light adjusting unit 20 or light before being transmitted.
Then, the laser beams R, G, and B adjusted by the white balance adjustment process shown in FIG. 11 enter the transmittedlight adjustment unit 20, and the CPU 310 adjusts the transmitted light white balance adjustment shown in FIG. Execute the process. As in the first modification, white balance adjustment may be performed in advance for the laser beams R, G, and B before entering the transmitted light adjusting unit 20.
そして、図11に示すホワイトバランス調整処理で調整されたレーザー光R,G,Bが透過光調整部20に入射し、この入射光に対して、CPU310は、図7に示す透過光ホワイトバランス調整処理を実行する。この変形例1のように、透過光調整部20に入射する前のレーザー光R,G,Bに対して、予めホワイトバランス調整を行っても良い。 In the
Then, the laser beams R, G, and B adjusted by the white balance adjustment process shown in FIG. 11 enter the transmitted
(変形例2)
図14(a)に示すように、変形例2に係る表示装置301においては、上述の実施形態と同様に、透過スクリーン50aの背面に光強度検出部60が設けられている。
さらに、変形例1と同様に、図14(b)に示すように、表示装置301は、各色用光強度検出部260r,260g,260bを備える。 (Modification 2)
As shown in FIG. 14A, in thedisplay device 301 according to the modified example 2, the light intensity detection unit 60 is provided on the back surface of the transmissive screen 50a as in the above-described embodiment.
Furthermore, as inModification 1, as shown in FIG. 14B, the display device 301 includes light intensity detection units 260r, 260g, and 260b for each color.
図14(a)に示すように、変形例2に係る表示装置301においては、上述の実施形態と同様に、透過スクリーン50aの背面に光強度検出部60が設けられている。
さらに、変形例1と同様に、図14(b)に示すように、表示装置301は、各色用光強度検出部260r,260g,260bを備える。 (Modification 2)
As shown in FIG. 14A, in the
Furthermore, as in
このように構成される変形例2に係る表示装置301では、CPU310は、まず、各色用光強度検出部260r,260g,260bから取得した光強度Ar,Ag,Abを基に、図11に示すホワイトバランス調整処理を実行する。そして、図11に示すホワイトバランス調整処理で調整されたレーザー光R,G,Bが透過光調整部20に入射し、この入射光に対して、CPU310は、図7に示す透過光ホワイトバランス調整処理を実行する。さらに、CPU310は、透過光調整部20を透過した後の光により、上記実施形態と同様に、図11に示すホワイトバランス調整処理を実行する。つまり、変形例2では、透過光調整部20で透過光ホワイトバランスを調整すると共に、透過光調整部20を透過の前後のレーザー光においてもホワイトバランスを調整する。このように、ホワイトバランスの調整を3回行うようにしてもよい。
In the display device 301 according to the modified example 2 configured as described above, the CPU 310 first shows the light intensity Ar, Ag, Ab obtained from the light intensity detection units 260r, 260g, 260b for each color as shown in FIG. Execute white balance adjustment processing. Then, the laser beams R, G, and B adjusted by the white balance adjustment process shown in FIG. 11 enter the transmitted light adjustment unit 20, and the CPU 310 adjusts the transmitted light white balance adjustment shown in FIG. Execute the process. Further, the CPU 310 executes the white balance adjustment process shown in FIG. 11 by the light after passing through the transmitted light adjusting unit 20 as in the above embodiment. That is, in Modification 2, the transmitted light adjusting unit 20 adjusts the transmitted light white balance, and the transmitted light adjusting unit 20 also adjusts the white balance in the laser light before and after transmission. In this way, white balance adjustment may be performed three times.
なお、本発明は、以上の実施形態及び変形例によって限定されるものではない。本発明の要旨を変更しない範囲で、適宜、変更(構成要素の削除も含む)を加えることが可能である。
In addition, this invention is not limited by the above embodiment and modification. Changes (including deletion of components) can be made as appropriate without departing from the scope of the present invention.
例えば、透過光調整部20は、レーザー光出射部11と集光部12との間に配置されてもよい。また、透過光調整部20は、レーザー光R,G,Bの色毎に透過率を制御しなくともよく、この場合、合波ユニット13よりも後の位置、つまり、合成レーザー光Cの光路上に配置されてもよい。
For example, the transmitted light adjusting unit 20 may be disposed between the laser beam emitting unit 11 and the light collecting unit 12. Further, the transmitted light adjusting unit 20 does not need to control the transmittance for each color of the laser beams R, G, and B. In this case, the position after the multiplexing unit 13, that is, the light of the combined laser beam C. It may be arranged on the road.
また、偏光板22に加えて、同様の偏光板をレーザー光出射部11側にさらに設けてもよい。この場合、上述と同様の電圧制御(オフ電圧印加時に不透過、オン電圧印加時に透過)では、追加した偏光板は、偏光板22とクロスニコルの関係で配置される。
Further, in addition to the polarizing plate 22, a similar polarizing plate may be further provided on the laser light emitting unit 11 side. In this case, with the same voltage control as described above (non-transmission when the off voltage is applied, and transmission when the on-voltage is applied), the added polarizing plate is arranged in a relationship between the polarizing plate 22 and crossed Nicols.
また、液晶セル21はVA型に限られず、TN(Twisted Nematic)型、STN(Super Twisted Nematic)型、IPS(In Plane Switching)型などであってもよい。
The liquid crystal cell 21 is not limited to the VA type, and may be a TN (Twisted Nematic) type, an STN (Super Twisted Nematic) type, an IPS (In Plane Switching) type, or the like.
また、光強度検出部60が検出する光強度は、レーザー光出射部11に供給される電流に応じて変化する物理量であればよく、輝度、照度、光度などであればよい。同様に、外光強度検出部90が検出する外光強度も照度に限られず、輝度、光度などであってもよい。
Further, the light intensity detected by the light intensity detection unit 60 may be a physical quantity that changes according to the current supplied to the laser light emitting unit 11, and may be luminance, illuminance, luminous intensity, or the like. Similarly, the external light intensity detected by the external light intensity detector 90 is not limited to illuminance, and may be brightness, luminous intensity, or the like.
以上では、図7に示す透過光ホワイトバランス処理において、線形補間法により、PWM値Dr,Dg,Dbや補正係数Cr,Cg,Cbを算出した例を示したが、これに限られない。例えば、CPU310は、液晶駆動用テーブルTA1を参照して、取得した外光強度Pにより近い値の外光強度に対応するPWM値を取得してもよい。同様に、CPU310は、補正用テーブルTA2を参照して、取得した検出温度Tにより近い値の検出温度に対応する補正係数を取得してもよい。
In the above, the example in which the PWM values Dr, Dg, Db and the correction coefficients Cr, Cg, Cb are calculated by the linear interpolation method in the transmitted light white balance process shown in FIG. 7 is shown, but the present invention is not limited to this. For example, the CPU 310 may acquire the PWM value corresponding to the external light intensity closer to the acquired external light intensity P with reference to the liquid crystal driving table TA1. Similarly, the CPU 310 may acquire the correction coefficient corresponding to the detected temperature closer to the acquired detected temperature T with reference to the correction table TA2.
また、以上では、図11に示すホワイトバランス調整処理において、CPU310が理想光強度を取得した光強度で除することで補正係数を算出する例を示したが、これに限られない。理想光強度で各LD11r,11g,11bを発光させることができるならば、補正係数の算出方法は任意である。
In the above, the example in which the CPU 310 calculates the correction coefficient by dividing the ideal light intensity by the acquired light intensity in the white balance adjustment process shown in FIG. 11 is not limited to this. If the LDs 11r, 11g, and 11b can emit light with the ideal light intensity, the correction coefficient calculation method is arbitrary.
また、CPU310は、光強度検出部60から各レーザー光R,G,Bの光強度Ar,Ag,Abを同時に取得してもよいし、色毎に時分割で取得してもよい。取得のタイミングは任意である。これは、変形例1及び2に係る各色用光強度検出部260r,260g,260bからの光強度Ar,Ag,Abの取得タイミングについても同様である。
Further, the CPU 310 may acquire the light intensities Ar, Ag, Ab of the laser beams R, G, B from the light intensity detector 60 at the same time, or may acquire them in time division for each color. The timing of acquisition is arbitrary. The same applies to the acquisition timing of the light intensities Ar, Ag, and Ab from the color light intensity detectors 260r, 260g, and 260b according to the first and second modifications.
以上の説明では、3つのLDが配設された例を示したが、これに限られない。4つのLDを配設して4原色で階調を表現してもよいし、1又は2つのLDで階調を表現してもよい。
In the above description, an example in which three LDs are arranged is shown, but the present invention is not limited to this. Four gradations may be arranged to express gradations with the four primary colors, or gradations may be expressed with one or two LDs.
以上の説明では、表示光Kを、2枚の鏡からなる反射部70で反射させ、ウインドシールド3に到達させる例を示したが、これに限られない。反射部70は、1又は3枚以上の鏡から構成されてもよい。また、透過スクリーン50からの表示光Kを、このような反射部を介さずに、ウインドシールド3、もしくは装置専用のコンバイナに向けて出射させるようにしてもよい。
In the above description, the example in which the display light K is reflected by the reflecting unit 70 including two mirrors and reaches the windshield 3 is not limited thereto. The reflection unit 70 may be composed of one or three or more mirrors. Further, the display light K from the transmissive screen 50 may be emitted toward the windshield 3 or the combiner dedicated to the apparatus without passing through such a reflection portion.
以上の説明では、表示装置1(以下、変形例に係る表示装置201,301についても同様)が搭載される乗り物の例を車両としたが、これに限られない。表示装置1を、その他の乗り物(船舶、航空機等)に設置することもできる。さらには、乗り物に設置するものには限られない。
In the above description, an example of a vehicle on which the display device 1 (hereinafter, the same applies to the display devices 201 and 301 according to modifications) is mounted as a vehicle, but is not limited thereto. The display device 1 can also be installed on other vehicles (ships, aircraft, etc.). Furthermore, it is not restricted to what is installed in a vehicle.
以上では、表示装置1が車両のダッシュボードと一体的に構成される例を示したが、表示装置1は、例えば、車両のダッシュボード上に設置される据え置き型(後付け型)のものであってもよい。
In the above, the example in which the display device 1 is configured integrally with the dashboard of the vehicle has been described. However, the display device 1 is, for example, a stationary type (retrofitted type) installed on the dashboard of the vehicle. May be.
以上では、表示装置1がヘッドアップディスプレイ(HUD)装置として構成された例を説明したが、これに限られない。その他の表示装置(例えばカーナビゲーション装置)であってもよい。但し、HUD装置は、背景(風景)と重ねて表示画像を視認させるため、特に、表示輝度の調整が必要であること、車両に搭載される場合が多いため、特に、温度変化が激しいこと等を踏まえると、上記のように各処理を実行する表示装置としては、HUD装置が好適である。
Although the example in which the display device 1 is configured as a head-up display (HUD) device has been described above, the present invention is not limited to this. Other display devices (for example, car navigation devices) may be used. However, since the HUD device allows the display image to be visually recognized overlaid on the background (landscape), it is particularly necessary to adjust the display brightness, and since it is often mounted on the vehicle, the temperature change is particularly severe. In view of the above, the HUD device is suitable as the display device that executes each process as described above.
以上に説明した表示装置1の一部により、レーザー光強度調整装置が構成される。
レーザー光強度調整装置は、レーザー光を発する光源(LD11r,11g,11b)と、光源が発したレーザー光を走査して表示画像Mを生成する走査部40と、光源から走査部40へと至る光路上に位置し、光源が発したレーザー光を所定の透過率で透過させる透過光調整部20であって、液晶セル21と偏光板22とを有する透過光調整部20と、液晶セル21の温度を検出する温度検出部30と、液晶セル21を駆動して透過光調整部20の透過率を制御する制御部300と、を備える。制御部300は、温度検出部30が検出した温度に基づいて、液晶セル21の温度変化による透過率の変動分を補正して透過光調整部20の透過率を制御し、走査部40に到達するレーザー光の光強度を調整する。
このようにしたから、透過光調整部20の透過率を制御して低強度のレーザー光を扱えると共に、液晶セル21の透過率の温度依存性を考慮してレーザー光を調整できる。つまり、以上に説明したレーザー光強度調整装置によれば、広い温度範囲においても、低強度のレーザー光を安定して調整することができる。 A part of thedisplay device 1 described above constitutes a laser light intensity adjusting device.
The laser light intensity adjusting device includes a light source ( LD 11r, 11g, 11b) that emits laser light, a scanning unit 40 that scans the laser light emitted from the light source to generate a display image M, and a light source to the scanning unit 40. A transmitted light adjusting unit 20 that is positioned on the optical path and transmits laser light emitted from a light source with a predetermined transmittance. The transmitted light adjusting unit 20 includes a liquid crystal cell 21 and a polarizing plate 22. A temperature detection unit 30 that detects the temperature and a control unit 300 that drives the liquid crystal cell 21 to control the transmittance of the transmitted light adjustment unit 20 are provided. Based on the temperature detected by the temperature detection unit 30, the control unit 300 corrects the variation in the transmittance due to the temperature change of the liquid crystal cell 21 to control the transmittance of the transmitted light adjustment unit 20 and reaches the scanning unit 40. Adjust the light intensity of the laser beam.
Since it did in this way, while controlling the transmittance | permeability of the transmittedlight adjustment part 20 and handling a low intensity | strength laser beam, a laser beam can be adjusted in consideration of the temperature dependence of the transmittance | permeability of the liquid crystal cell 21. FIG. That is, according to the laser light intensity adjusting device described above, low-intensity laser light can be stably adjusted even in a wide temperature range.
レーザー光強度調整装置は、レーザー光を発する光源(LD11r,11g,11b)と、光源が発したレーザー光を走査して表示画像Mを生成する走査部40と、光源から走査部40へと至る光路上に位置し、光源が発したレーザー光を所定の透過率で透過させる透過光調整部20であって、液晶セル21と偏光板22とを有する透過光調整部20と、液晶セル21の温度を検出する温度検出部30と、液晶セル21を駆動して透過光調整部20の透過率を制御する制御部300と、を備える。制御部300は、温度検出部30が検出した温度に基づいて、液晶セル21の温度変化による透過率の変動分を補正して透過光調整部20の透過率を制御し、走査部40に到達するレーザー光の光強度を調整する。
このようにしたから、透過光調整部20の透過率を制御して低強度のレーザー光を扱えると共に、液晶セル21の透過率の温度依存性を考慮してレーザー光を調整できる。つまり、以上に説明したレーザー光強度調整装置によれば、広い温度範囲においても、低強度のレーザー光を安定して調整することができる。 A part of the
The laser light intensity adjusting device includes a light source (
Since it did in this way, while controlling the transmittance | permeability of the transmitted
また、レーザー光強度調整装置は、液晶セル21の温度と対応付けられた補正データ(補正用テーブルTA2における補正係数Cr,Cg,Cbの一例)を記憶する記憶部320をさらに備え、制御部300は、温度検出部30が検出した温度と補正データとに基づいて、液晶セル21の温度変化による透過率の変動分を補正して透過光調整部20の透過率を制御する。
この場合において、補正データをレーザー光R,G,Bの色毎に設ければ、各色用液晶セル21r,21g,21bの透過率の温度依存性を考慮してレーザー光を調整できるため、より良い。 The laser light intensity adjusting device further includes astorage unit 320 that stores correction data associated with the temperature of the liquid crystal cell 21 (an example of correction coefficients Cr, Cg, and Cb in the correction table TA2). Controls the transmittance of the transmitted light adjusting unit 20 by correcting the variation of the transmittance due to the temperature change of the liquid crystal cell 21 based on the temperature detected by the temperature detecting unit 30 and the correction data.
In this case, if the correction data is provided for each color of the laser beams R, G, and B, the laser beam can be adjusted in consideration of the temperature dependency of the transmittance of each color liquid crystal cell 21r, 21g, 21b. good.
この場合において、補正データをレーザー光R,G,Bの色毎に設ければ、各色用液晶セル21r,21g,21bの透過率の温度依存性を考慮してレーザー光を調整できるため、より良い。 The laser light intensity adjusting device further includes a
In this case, if the correction data is provided for each color of the laser beams R, G, and B, the laser beam can be adjusted in consideration of the temperature dependency of the transmittance of each color
また、透過光調整部20は、制御部300によってレーザー光の色毎に透過率が制御され、制御部300は、走査部40に到達するレーザー光の色毎の光強度を調整することで、表示画像Mのホワイトバランスを調整する。
このようにしたから、広い温度範囲下で、表示画像Mの低輝度表示が可能であり、且つ、適切なホワイトバランスでの表示が可能である。 Further, in the transmittedlight adjusting unit 20, the transmittance is controlled for each color of the laser light by the control unit 300, and the control unit 300 adjusts the light intensity for each color of the laser light reaching the scanning unit 40, The white balance of the display image M is adjusted.
Thus, the display image M can be displayed with a low luminance under a wide temperature range, and can be displayed with an appropriate white balance.
このようにしたから、広い温度範囲下で、表示画像Mの低輝度表示が可能であり、且つ、適切なホワイトバランスでの表示が可能である。 Further, in the transmitted
Thus, the display image M can be displayed with a low luminance under a wide temperature range, and can be displayed with an appropriate white balance.
また、特に、上記実施形態及び変形例2においては、透過光調整部20を透過したレーザー光の光強度を検出する透過光強度検出部(光強度検出部60の一例)をさらに備える。そして、制御部300は、(i)透過光強度検出部が検出した光強度に基づいて、LD駆動部100を介して、光源(LD11r,11g,11b)に供給する電流を調整することで、さらに表示画像Mのホワイトバランスを調整する、または、(ii)透過光強度検出部が検出した光強度に基づいて画像データを補正することで、さらに前記表示画像のホワイトバランスを調整する。
In particular, in the above-described embodiment and Modification 2, a transmitted light intensity detecting unit (an example of the light intensity detecting unit 60) that detects the light intensity of the laser light transmitted through the transmitted light adjusting unit 20 is further provided. And the control part 300 adjusts the electric current supplied to the light source (LD11r, 11g, 11b) via the LD drive part 100 based on the light intensity which the (i) transmitted light intensity detection part detected, Further, the white balance of the display image M is adjusted, or (ii) the white balance of the display image is further adjusted by correcting the image data based on the light intensity detected by the transmitted light intensity detector.
また、特に、上記変形例1及び2においては、透過光調整部20を透過する前のレーザー光の光強度を検出する光強度検出部(各色用光強度検出部260r,260g,260bの一例)をさらに備える。そして、制御部300は、(i)光強度検出部が検出した光強度に基づいて光源に供給する電流を調整することで、透過光調整部20を透過する前のレーザー光においても表示画像Mのホワイトバランスを調整する、または、(ii)光強度検出部が検出した光強度に基づいて画像データを補正することでも、表示画像Mのホワイトバランスを調整する。
この場合において、変形例2においては、透過光調整部20を透過したレーザー光の光強度を検出する透過光強度検出部(光強度検出部60の一例)をさらに備え、制御部300は、透過光強度検出部が検出した光強度に基づいて、調整されたホワイトバランスを補正する。 In particular, in the first and second modified examples, the light intensity detecting unit that detects the light intensity of the laser light before passing through the transmitted light adjusting unit 20 (an example of the light intensity detecting units 260r, 260g, and 260b for each color). Is further provided. And the control part 300 adjusts the electric current supplied to a light source based on the light intensity which the light intensity detection part detected (i) display image M also in the laser beam before permeate | transmitting the transmitted light adjustment part 20. The white balance of the display image M is also adjusted by adjusting the white balance of (ii) or (ii) correcting the image data based on the light intensity detected by the light intensity detector.
In this case, the second modification further includes a transmitted light intensity detecting unit (an example of the light intensity detecting unit 60) that detects the light intensity of the laser light transmitted through the transmittedlight adjusting unit 20, and the control unit 300 includes The adjusted white balance is corrected based on the light intensity detected by the light intensity detector.
この場合において、変形例2においては、透過光調整部20を透過したレーザー光の光強度を検出する透過光強度検出部(光強度検出部60の一例)をさらに備え、制御部300は、透過光強度検出部が検出した光強度に基づいて、調整されたホワイトバランスを補正する。 In particular, in the first and second modified examples, the light intensity detecting unit that detects the light intensity of the laser light before passing through the transmitted light adjusting unit 20 (an example of the light
In this case, the second modification further includes a transmitted light intensity detecting unit (an example of the light intensity detecting unit 60) that detects the light intensity of the laser light transmitted through the transmitted
以上の説明では、本発明の理解を容易にするために、重要でない公知の技術的事項の説明を適宜省略した。
In the above description, in order to facilitate the understanding of the present invention, explanations of known unimportant technical matters are appropriately omitted.
本発明は、レーザー光を走査することで画像を生成する表示装置(レーザー走査型画像生成装置)などに適用可能であり、特に、車両などの移動体に搭載され、広い使用温度範囲で広い輝度の画像生成が要求されるヘッドアップディスプレイにおける車両用表示装置(車両用レーザー走査型画像生成装置)としても適用可能である。
INDUSTRIAL APPLICABILITY The present invention is applicable to a display device (laser scanning image generating device) that generates an image by scanning a laser beam, and is particularly mounted on a moving body such as a vehicle and has a wide luminance in a wide operating temperature range. It is also applicable as a vehicle display device (vehicle laser scanning image generation device) in a head-up display that requires image generation.
1 表示装置
10 合成レーザー光生成部
11 レーザー光出射部
11r,11g,11b レーザーダイオード(LD)
20 透過光調整部
21 液晶セル
21r 赤色用液晶セル
21g 緑色用液晶セル
21b 青色用液晶セル
22 偏光板
30 温度検出部
40 走査部
50 透過スクリーン
60 光強度検出部
70 反射部
90 外光強度検出部
100 LD駆動部
200 液晶駆動部
300 制御部
310 CPU
320 記憶部
400 走査駆動部
M 表示画像
K 表示光
TA1 液晶駆動用テーブル
TA2 補正用テーブル DESCRIPTION OFSYMBOLS 1 Display apparatus 10 Synthetic laser beam production | generation part 11 Laser beam emission part 11r, 11g, 11b Laser diode (LD)
DESCRIPTION OFSYMBOLS 20 Transmitted light adjustment part 21 Liquid crystal cell 21r Red liquid crystal cell 21g Green liquid crystal cell 21b Blue liquid crystal cell 22 Polarizing plate 30 Temperature detection part 40 Scanning part 50 Transmission screen 60 Light intensity detection part 70 Reflection part 90 Outside light intensity detection part 100 LD driving unit 200 Liquid crystal driving unit 300 Control unit 310 CPU
320Storage unit 400 Scanning drive unit M Display image K Display light TA1 Liquid crystal drive table TA2 Correction table
10 合成レーザー光生成部
11 レーザー光出射部
11r,11g,11b レーザーダイオード(LD)
20 透過光調整部
21 液晶セル
21r 赤色用液晶セル
21g 緑色用液晶セル
21b 青色用液晶セル
22 偏光板
30 温度検出部
40 走査部
50 透過スクリーン
60 光強度検出部
70 反射部
90 外光強度検出部
100 LD駆動部
200 液晶駆動部
300 制御部
310 CPU
320 記憶部
400 走査駆動部
M 表示画像
K 表示光
TA1 液晶駆動用テーブル
TA2 補正用テーブル DESCRIPTION OF
DESCRIPTION OF
320
Claims (10)
- レーザー光を発する光源と、
前記光源が発したレーザー光を走査して表示画像を生成する走査部と、
前記光源から前記走査部へと至る光路上に位置し、前記光源が発したレーザー光を所定の透過率で透過させる透過光調整部であって、液晶セルと偏光板とを有する透過光調整部と、
前記液晶セルの温度を検出する温度検出部と、
前記液晶セルを駆動して前記透過光調整部の透過率を制御する制御部と、を備え、
前記制御部は、前記温度検出部が検出した温度に基づいて、前記液晶セルの温度変化による透過率の変動分を補正して前記透過光調整部の透過率を制御し、前記走査部に到達するレーザー光の光強度を調整する、
ことを特徴とするレーザー光強度調整装置。 A light source that emits laser light;
A scanning unit that scans laser light emitted from the light source to generate a display image;
A transmitted light adjusting unit that is located on an optical path from the light source to the scanning unit and transmits laser light emitted from the light source with a predetermined transmittance, and includes a liquid crystal cell and a polarizing plate. When,
A temperature detector for detecting the temperature of the liquid crystal cell;
A control unit for driving the liquid crystal cell to control the transmittance of the transmitted light adjusting unit,
The control unit controls the transmittance of the transmitted light adjustment unit by correcting the variation of the transmittance due to the temperature change of the liquid crystal cell based on the temperature detected by the temperature detection unit, and reaches the scanning unit Adjust the light intensity of the laser light,
A laser light intensity adjusting device characterized by that. - 前記液晶セルの温度と対応付けられた補正データを記憶する記憶部をさらに備え、
前記制御部は、前記温度検出部が検出した温度と前記補正データとに基づいて、前記液晶セルの温度変化による透過率の変動分を補正して前記透過光調整部の透過率を制御する、
ことを特徴とする請求項1に記載のレーザー光強度調整装置。 A storage unit for storing correction data associated with the temperature of the liquid crystal cell;
The control unit controls the transmittance of the transmitted light adjustment unit by correcting a variation in transmittance due to a temperature change of the liquid crystal cell based on the temperature detected by the temperature detection unit and the correction data.
The laser beam intensity adjusting device according to claim 1. - 前記光源は、複数あり、各々異なる色のレーザー光を発し、
前記透過光調整部は、前記制御部によってレーザー光の色毎に透過率が制御され、
前記制御部は、前記走査部に到達するレーザー光の色毎の光強度を調整することで、前記表示画像のホワイトバランスを調整する、
ことを特徴とする請求項1又は2に記載のレーザー光強度調整装置。 There are a plurality of the light sources, each emitting laser light of a different color,
In the transmitted light adjusting unit, the transmittance is controlled for each color of laser light by the control unit,
The control unit adjusts the white balance of the display image by adjusting the light intensity for each color of the laser light reaching the scanning unit,
The laser beam intensity adjusting device according to claim 1 or 2, characterized in that - 前記透過光調整部を透過したレーザー光の光強度を検出する透過光強度検出部をさらに備え、
前記制御部は、前記透過光強度検出部が検出した光強度に基づいて前記光源に供給する電流を調整することで、さらに前記表示画像のホワイトバランスを調整する、
ことを特徴とする請求項3に記載のレーザー光強度調整装置。 Further comprising a transmitted light intensity detection unit for detecting the light intensity of the laser light transmitted through the transmitted light adjustment unit,
The controller further adjusts the white balance of the display image by adjusting a current supplied to the light source based on the light intensity detected by the transmitted light intensity detector.
The laser beam intensity adjusting device according to claim 3. - 前記透過光調整部を透過したレーザー光の光強度を検出する透過光強度検出部をさらに備え、
前記制御部は、前記透過光強度検出部が検出した光強度に基づいて画像データを補正することで、さらに前記表示画像のホワイトバランスを調整する、
ことを特徴とする請求項3に記載のレーザー光強度調整装置。 Further comprising a transmitted light intensity detection unit for detecting the light intensity of the laser light transmitted through the transmitted light adjustment unit,
The controller further adjusts the white balance of the display image by correcting the image data based on the light intensity detected by the transmitted light intensity detector.
The laser beam intensity adjusting device according to claim 3. - 前記透過光調整部を透過する前のレーザー光の光強度を検出する光強度検出部をさらに備え、
前記制御部は、前記光強度検出部が検出した光強度に基づいて前記光源に供給する電流を調整することで、前記透過光調整部を透過する前のレーザー光においても前記表示画像のホワイトバランスを調整する、
ことを特徴とする請求項3に記載のレーザー光強度調整装置。 A light intensity detection unit for detecting the light intensity of the laser light before passing through the transmitted light adjustment unit;
The control unit adjusts a current supplied to the light source based on the light intensity detected by the light intensity detection unit, so that the white balance of the display image is also obtained in the laser light before passing through the transmitted light adjustment unit. Adjust the
The laser beam intensity adjusting device according to claim 3. - 前記透過光調整部を透過する前のレーザー光の光強度を検出する光強度検出部をさらに備え、
前記制御部は、前記光強度検出部が検出した光強度に基づいて画像データを補正することでも、前記表示画像のホワイトバランスを調整する、
ことを特徴とする請求項3に記載のレーザー光強度調整装置。 A light intensity detection unit for detecting the light intensity of the laser light before passing through the transmitted light adjustment unit;
The control unit also adjusts the white balance of the display image by correcting image data based on the light intensity detected by the light intensity detection unit.
The laser beam intensity adjusting device according to claim 3. - 前記透過光調整部を透過したレーザー光の光強度を検出する透過光強度検出部をさらに備え、
前記制御部は、前記透過光強度検出部が検出した光強度に基づいて、調整されたホワイトバランスを補正する、
ことを特徴とする請求項6又は7に記載のレーザー光強度調整装置。 Further comprising a transmitted light intensity detection unit for detecting the light intensity of the laser light transmitted through the transmitted light adjustment unit,
The control unit corrects the adjusted white balance based on the light intensity detected by the transmitted light intensity detection unit.
The laser light intensity adjusting device according to claim 6 or 7, wherein - 前記制御部は、前記光強度検出部が検出したレーザー光の光強度をレーザー光の色毎に時分割で取得する、
ことを特徴とする請求項6乃至8のいずれか1項に記載のレーザー光強度調整装置。 The control unit acquires the light intensity of the laser light detected by the light intensity detection unit in a time-sharing manner for each color of the laser light.
The laser beam intensity adjusting device according to any one of claims 6 to 8. - 前記制御部は、前記透過光強度検出部が検出したレーザー光の光強度をレーザー光の色毎に時分割で取得する、
ことを特徴とする請求項4、5、又は8に記載のレーザー光強度調整装置。 The control unit acquires the light intensity of the laser light detected by the transmitted light intensity detection unit in a time-sharing manner for each color of the laser light.
The laser beam intensity adjusting device according to claim 4, 5, or 8.
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Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN115220226A (en) * | 2021-04-15 | 2022-10-21 | 通用汽车环球科技运作有限责任公司 | Head-up display image blur compensation |
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Publication number | Priority date | Publication date | Assignee | Title |
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JP6848354B2 (en) * | 2016-11-04 | 2021-03-24 | 船井電機株式会社 | Light projection device |
JP7528794B2 (en) | 2021-01-12 | 2024-08-06 | 日本精機株式会社 | Head-up display |
JP7494814B2 (en) | 2021-07-19 | 2024-06-04 | 株式会社デンソー | Display device |
Citations (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2008225438A (en) * | 2007-02-13 | 2008-09-25 | Nippon Seiki Co Ltd | Display device for vehicle |
JP2009037211A (en) * | 2007-08-03 | 2009-02-19 | Ctx Opto Electronics Corp | Display device |
JP2012022023A (en) * | 2010-07-12 | 2012-02-02 | Nippon Seiki Co Ltd | Field sequential image display device |
JP2012047926A (en) * | 2010-08-26 | 2012-03-08 | Funai Electric Co Ltd | Laser projector |
JP2013015738A (en) * | 2011-07-06 | 2013-01-24 | Nippon Seiki Co Ltd | Head-up display device |
JP2013250539A (en) * | 2012-06-04 | 2013-12-12 | Seiko Epson Corp | Image display device and head mounted display |
-
2014
- 2014-03-24 JP JP2014060097A patent/JP2015184435A/en active Pending
-
2015
- 2015-03-13 WO PCT/JP2015/057417 patent/WO2015146618A1/en active Application Filing
Patent Citations (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2008225438A (en) * | 2007-02-13 | 2008-09-25 | Nippon Seiki Co Ltd | Display device for vehicle |
JP2009037211A (en) * | 2007-08-03 | 2009-02-19 | Ctx Opto Electronics Corp | Display device |
JP2012022023A (en) * | 2010-07-12 | 2012-02-02 | Nippon Seiki Co Ltd | Field sequential image display device |
JP2012047926A (en) * | 2010-08-26 | 2012-03-08 | Funai Electric Co Ltd | Laser projector |
JP2013015738A (en) * | 2011-07-06 | 2013-01-24 | Nippon Seiki Co Ltd | Head-up display device |
JP2013250539A (en) * | 2012-06-04 | 2013-12-12 | Seiko Epson Corp | Image display device and head mounted display |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN115220226A (en) * | 2021-04-15 | 2022-10-21 | 通用汽车环球科技运作有限责任公司 | Head-up display image blur compensation |
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