JP6168174B2 - projector - Google Patents

Description

  The present invention relates to a projector and an electronic apparatus having a projector function, and in particular, a projector including a light detection unit that detects a laser beam irradiated from a laser light generation unit and reflected by an object to be detected, and an electronic apparatus having a projector function. About.

  2. Description of the Related Art Conventionally, there has been known a projector including a light detection unit that detects laser light emitted from a laser light generation unit and reflected by a detection target (see, for example, Patent Document 1).

  In Patent Document 1, a laser light source (laser light generation unit) that emits laser light based on an input image signal and a laser light emitted from the laser light source are scanned to form an image in an arbitrary projection region. A projector including a scanning unit (projecting unit) for projecting and a light receiving sensor (light detecting unit) for detecting laser light emitted from a laser light source and reflected by an external obstacle (detection target) is disclosed. Yes.

JP 2009-123006 A

  However, in the conventional projector as described in Patent Document 1, the external obstacle is detected by detecting the reflected light from the external obstacle (detection target) by the light receiving sensor, so that the reflection from the external obstacle is detected. It is considered that there is a problem that an external obstacle may not be detected when an image of black or a color similar to black is difficult to detect light.

  The present invention has been made to solve the above-described problems, and one object of the present invention is when the color of a projected image is a color in which it is difficult to detect reflected light from a detection object. Another object is to provide a projector capable of reliably detecting a detection target and an electronic device having a projector function.

Means for Solving the Problems and Effects of the Invention

A projector according to a first aspect of the present invention includes a laser light generation unit that emits laser light based on an image signal, a projection unit that projects laser light, and light detection that detects laser light reflected from a detection target. and parts, based on the voltage corresponding to the color information included in the image signal, voltage rather smaller than a predetermined threshold and, if a predetermined time continues to projection state is not changed, the light reflection than the predetermined threshold And a control unit that performs control to emit laser light having a large corresponding voltage.

In the projector according to the first aspect of the present invention, by providing the control unit described above, even when an image of a color that cannot be expected to be detected by the light detection unit is projected, the laser beam having a reflected light voltage larger than a predetermined threshold value. Is projected onto the projection area, the reflected light from the detection object can be detected by the light detection unit. Thereby, even when the color of the projected image is a color in which it is difficult to detect the reflected light from the detection object, the detection object can be reliably detected. In addition, since the laser beam generator can be used as a laser beam generator having a large reflected light voltage, there is no need to provide a dedicated generator such as an infrared generator. As a result, the configuration of the projector can be simplified. Further, even when the reflected light voltage acquired in advance based on the color information of the input image signal is smaller than the predetermined threshold, the reflected light of the laser light having a reflected light voltage larger than the predetermined threshold is used. The detection object can be reliably detected by the light detection unit. In addition, the reflected light from the laser light generator is reflected only when the reflected light voltage acquired in advance based on the color information of the image signal is smaller than a predetermined threshold and cannot be detected by the light detector for a predetermined time. Since laser light having a high light voltage is irradiated, it is possible to suppress the occurrence of noise or the like due to laser light having a high reflected light voltage in an image based on an input image signal as much as possible.

In the projector according to the first aspect, preferably, the control unit is a laser having a large voltage corresponding to the reflected light based on the voltage corresponding to the color information included in the image signal when the voltage is equal to or higher than a predetermined threshold. Based on the detection result of the reflected light of the laser beam corresponding to the image signal, control for specifying the position of the detection target is performed without projecting light. According to this configuration, when the reflected light voltage is equal to or higher than a predetermined threshold and detection by the light detection unit can be expected, it corresponds to an image signal input without using a laser beam having a high reflected light voltage. Since the position of the detection target is specified using the laser light, it is possible to suppress the occurrence of noise or the like due to the laser light having a large reflected light voltage in the image based on the input image signal as much as possible.

In the projector according to the first aspect, preferably, the laser light generating portion, and the red laser light generator for emitting red laser light, green laser light generator for emitting green laser light, blue laser light together and a blue laser light generator for emitting the control unit generates a high laser beam reflectivity of the detection object of the red laser light generator, a green laser light generator and the blue laser light generator from at least one laser light generator is configured to perform control for emitting a laser beam voltage larger corresponding to the reflected light. If comprised in this way, since the laser beam with a high reflected light voltage can be comprised with the laser beam with a high reflectance of a detection target object, the reflected light by a detection target object is detected accurately by a light detection part. be able to.

In the projector according to the first aspect, preferably, the laser light generating portion, and the red laser light generator for emitting red laser light, green laser light generator for emitting green laser light, blue laser light together and a blue laser light generator for emitting the light detection unit includes a detection sensitivity different characteristics on the wavelength of the detection laser beam, the control unit, the red laser light generator, a green laser light generator, and from at least one laser light generator detection sensitivity by the light detecting portion of the blue laser light generator generates a laser beam of good wavelength, to perform control for emitting a laser beam voltage larger corresponding to the reflected light It is configured. With this configuration, a laser beam having a high reflected light voltage can be configured by a laser beam having a wavelength with a good detection sensitivity by the light detection unit. Therefore, the light detection unit reflects the reflected light from the detection target. Can be detected with high accuracy.

In the configuration in which the laser beam having a high reflectance of the detection target or the laser beam having a good detection sensitivity by the photodetector is emitted as a laser beam having a large voltage corresponding to the reflected light, the light detection unit preferably has a red color. A laser that includes a light detection unit whose detection sensitivity of laser light is better than that of green and blue laser light, and the control unit is a laser having a large voltage corresponding to reflected light composed of red laser light from the red laser light generation unit and we are configured to perform control of emitting light. With this configuration, the red laser light generating unit emits the red laser light having the highest reflectance from the detection target and the highest detection sensitivity as the laser light having a large reflected light voltage. The reflected light of the red laser beam can be detected with high accuracy by the light detection unit.

In the projector according to the first aspect, it is preferable that the control unit responds to the reflected light when the voltage is smaller than a predetermined threshold based on the voltage corresponding to the color information included in the image signal in the normal mode. performs control for emitting voltage is large laser beam, in the case of energy conservation Rugimodo the image based on the image signal is not projected, if the energy saving mode is continued for a predetermined time, the laser voltage larger corresponding to the reflected light and it is configured to perform control of emitting light. If comprised in this way, even if it is a case of the energy saving mode in which the image based on the input image signal is not projected, it is a detection target object using the laser beam with the large voltage of the reflected light irradiated from a laser beam generation part. Can be reliably detected. Further, based on the detection result, processing such as switching from the energy saving mode to the normal mode (returning to the normal mode) can be performed.

In this case, preferably, the control unit, in the case of projecting a laser beam corresponding to the image signal in the normal mode, projecting shadows laser beam voltage corresponding to the reflected light is large in addition to the laser light corresponding to the image signal as well as, in the case of energy-saving mode is made only the laser beam voltage larger corresponding to the reflected light to perform control of projected shadows. With this configuration, in the normal mode, it is possible to reliably detect a detection target by projecting a laser beam having a large reflected light voltage while projecting an image based on an input image signal. In addition, in the case of the energy saving mode, it is possible to detect the detection target object by projecting only the laser light having a large reflected light voltage.

In the configuration in which the laser beam having a large voltage corresponding to the reflected light is projected when the energy saving mode is continued for a predetermined time, the control unit preferably responds to the reflected light by the light detection unit in the energy saving mode. When reflected light of laser light having a high voltage is detected, control is performed to return from the energy saving mode to the normal mode. With this configuration, in the energy saving mode, the user can easily return the projector from the normal mode to the energy saving mode simply by placing the detection target in the projection area.

It is the schematic diagram which showed the use condition of the projector by 1st Embodiment of this invention. 1 is a block diagram showing a configuration of a projector according to a first embodiment of the present invention. It is the figure which showed the detection sensitivity characteristic of the photon detection part of the projector by 1st Embodiment of this invention. It is a figure for demonstrating the calculation method of the detection detection voltage of the projector by 1st Embodiment of this invention. It is the figure which showed the state which projects a detection guide light on the projection area | region of the projector by 1st Embodiment of this invention. It is a flowchart for demonstrating the position detection process in the normal mode of the projector by 1st Embodiment of this invention. It is a flowchart for demonstrating the position detection process in the normal mode of the projector by 1st Embodiment of this invention. It is a flowchart for demonstrating the system return process in the energy saving mode of the projector by 2nd Embodiment of this invention.

  DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments embodying the present invention will be described below with reference to the drawings.

(First embodiment)
With reference to FIG. 1 and FIG. 2, the structure of the projector 100 by 1st Embodiment of this invention is demonstrated. The projector 100 is an example of the “electronic device having a projector function” in the present invention.

  A projector 100 according to the first embodiment of the present invention is configured to be used on a table 1 as shown in FIG. The projector 100 is configured such that a presentation (display) image 2a is projected onto a projection area such as the screen 2. Further, the projector 100 is configured to project an image 1a similar to the presentation image 2a onto the upper surface of a projection area such as the table 1. The size of the image 1a projected on the table 1 is projected to be smaller than the size of the image 2a projected on the screen 2. The table 1 and the screen 2 are examples of the “projection area” in the present invention.

  A silicon photodiode 10a for detecting laser light reflected by the user's finger or touch pen is provided on the side surface of the projector 100 on which the image 1a is projected. The silicon photodiode 10a has a function of detecting a laser beam by converting the received laser beam into an electric current. Further, as shown in FIG. 3, the silicon photodiode 10a has a detection sensitivity characteristic that the detection sensitivity varies depending on the wavelength (color) of the received light. Specifically, the silicon photodiode 10a has a characteristic that the detection sensitivity is high in the order of red (650 nm), green (520 nm), and blue (440 nm), and the detection sensitivity gradually increases as the color approaches blue from red. ing. The silicon photodiode 10a is an example of the “photodetector” in the present invention.

  Further, as shown in FIG. 1, a laser projection port 10b to which red, green and blue visible laser beams are irradiated is provided above the silicon photodiode 10a of the projector 100.

  As shown in FIG. 2, the projector 100 includes an operation panel 20, a control processing block 30, a data processing block 40, a digital signal processor (DSP) 50, a laser light source 60, a video RAM 71, and a beam splitter 80. Two magnifying lenses 90 and 91 are included. The laser light source 60 is an example of the “laser light generator” in the present invention.

  The control processing block 30 includes a control unit 31 that controls the entire projector 100, a video I / F 32 that is an interface (I / F) for receiving an external video signal, a RAM 33, and an external I / F 34. .

  The data processing block 40 includes a data / gradation converter 41, a bit data converter 42, a timing controller 43, and a data controller 44.

  The digital signal processor 50 includes a mirror servo block 51 and a converter 52.

  The laser light source 60 includes a red laser control circuit 61, a green laser control circuit 62, and a blue laser control circuit 63. The red laser control circuit 61, the green laser control circuit 62, and the blue laser control circuit 63 are respectively provided with a red LD (laser diode) 61a that emits red laser light (visible laser light), and green. A green LD 62a that emits laser light (visible laser light) and a blue LD 63a that emits blue laser light (visible laser light) are connected. The laser light source 60 is configured to emit laser light based on an external video signal input to the projector 100 described later or data stored in the portable memory 92. The red LD 61a is an example of the “red laser beam generator” in the present invention. The green LD 62a is an example of the “green laser light generator” in the present invention. The blue LD 63a is an example of the “blue laser light generator” in the present invention.

  The laser light source 60 includes three collimating lenses 64, three polarizing beam splitters 65a, 65b and 65c, a photodetector 66, and a lens 67. Further, a MEMS mirror 68a for scanning the laser light in the horizontal direction and the vertical direction, and an actuator 70 for driving the MEMS mirror 68a in the horizontal direction and the vertical direction are provided. The MEMS mirror 68a is an example of the “projection unit” in the present invention.

  Further, the laser beams emitted by the red LD 61a, the green LD 62a, and the blue LD 63a are configured to be incident on the common MEMS mirror 68a. The red, green, and blue laser beams emitted from the red LD 61a, the green LD 62a, and the blue LD 63a are scanned on the MEMS mirror 68a, whereby the images 1a and 2a are projected on the table 1 and the screen 2, respectively. The MEMS mirror 68a is configured to project an image on an arbitrary projection region by scanning the laser light emitted from the laser light source 60.

  As shown in FIG. 2, the operation panel 20 is provided on the surface or side surface of the housing of the projector 100. Operation panel 20 includes, for example, a display device (not shown) for displaying operation details, a switch for receiving an operation input to projector 100, and the like. The operation panel 20 is configured to transmit a signal corresponding to the operation content to the control unit 31 of the control processing block 30 when receiving an operation from the user.

  An external video signal given from the outside of the projector 100 is input to the Video I / F 32. Further, the external I / F 34 is configured to be able to be mounted with a portable memory 92 such as an SD card or a USB memory. A PC or the like can be connected to the external I / F 34 via a cable or the like, and the external I / F 34 functions as an output unit that can transmit position information of the touch pen held by the user to the PC. It is configured. The control unit 31 is configured to read data from the portable memory 92 and store the read data in the Video RAM 71.

  The control unit 31 is configured to control display of video based on image data temporarily stored in the Video RAM 71 by communicating with the timing controller 43 of the data processing block 40.

  In the data processing block 40, the timing controller 43 is configured to read data held in the video RAM 71 via the data controller 44 based on a signal output from the control unit 31. The data controller 44 is configured to transmit the read data to the bit data converter 42. The bit data converter 42 is configured to transmit data to the data / gradation converter 41 based on a signal from the timing controller 43. The bit data converter 42 has a function of converting image data given from the outside into data suitable for a format that can be projected by laser light.

  The data / gradation converter 41 converts the data output from the bit data converter 42 into gradations of three colors of red (R: Red), green (G: Green), and blue (B: Blue), The converted gradation data is transmitted to the red laser control circuit 61, the green laser control circuit 62, and the blue laser control circuit 63, respectively.

  The red laser control circuit 61 is configured to control the red LD 61a to have a laser output value corresponding to the gradation based on the gradation data from the data / gradation converter 41. The green laser control circuit 62 is configured to control the green LD 62a to have a laser output value corresponding to the gradation based on the gradation data from the data / gradation converter 41. The blue laser control circuit 63 is configured to control the blue LD 63a to have a laser output value corresponding to the gradation based on the gradation data from the data / gradation converter 41.

  The silicon photodiode 10a provided on the side surface of the projector 100 on which the image 1a is projected is configured to detect the laser light emitted from the laser light source 60 and reflected by the detection target. A signal received by the silicon photodiode 10 a is input to the control unit 31 via the converter 52.

  Here, in the first embodiment, the control unit 31 acquires the detection expected voltage of the silicon photodiode 10a based on the gradation of the input image signal, and the acquired detection expected voltage is a predetermined value of the silicon photodiode 10a. When it is smaller than the threshold, the detection guide light for detection of the silicon photodiode 10a that is different from the laser light corresponding to the input image signal is emitted from the red LD 61a and projected onto an arbitrary projection area. ing. That is, the control unit 31 is configured to project the red detection guide light onto an arbitrary projection area when the detection of the laser light corresponding to the input image signal by the silicon photodiode 10a cannot be expected. The expected detection voltage is an example of the “reflected light voltage” in the present invention. The detection guide light is an example of the “laser light whose reflected light voltage is larger than a predetermined threshold value” in the present invention.

  In addition, the control unit 31 reads gradation information from an external video signal input via the Video I / F 32 or an image signal input from the portable memory 92 connected via the external I / F 34, and The laser output values of the red LD 61a, the green LD 62a, and the blue LD 63a are acquired as the result of the tone analysis. In addition, the control unit 31 reads information on gradation from an external video signal input via the video I / F 32 or an image signal input from the portable memory 92 connected via the external I / F 34. It is configured to recognize that a new image has been input. In addition, the control unit 31 calculates a laser output value for each of the red LD 61a, the green LD 62a, and the blue LD 63a. For example, as shown in FIG. 4, when white is projected, all of red, green, and blue are output in 256 gradations, which are the maximum gradations, and the red LD 61a, green LD 62a, and blue LD 63a at that time are output. The laser output values are 235 (mW), 200 (mW) and 80 (mW), respectively. As described above, the output value of the maximum gradation differs depending on red, green, and blue. When the color to be projected is other than white, the laser output values of the red LD 61a, the green LD 62a, and the blue LD 63a are changed according to the change rate of the gradation of each color of red, green, and blue with respect to white. Note that gradation is an example of “color information” in the present invention.

  Further, the reflectance of the detection object is different for each of the red, green, and blue laser beams. Further, the transmittance of the optical system is the transmittance of the laser light to the collimating lens 64, the polarization beam splitters 65a, 65b, 65c, the lens 67, the beam splitter 80, and the magnifying lenses 90, 91, and each of red, green, and blue The laser beams are different from each other.

  Before the image is input to the projector 100, the control unit 31 has a different reflectance for each of the red laser light, the green laser light, and the blue laser light on the detection target, and the red laser light, the green laser light, and the blue laser light. It is configured to perform measurement (offset calculation) with the transmittance of a different optical system for each laser beam. In addition, the control unit 31 calculates an expected detection voltage using each of red, green, and blue sensitivity coefficients obtained based on the detection sensitivity characteristics of the silicon photodiode 10a shown in FIG. In the first embodiment, the red, green, and blue sensitivity coefficients of the silicon photodiode 10a are 0.00045 (mA / mW), 0.00027 (mA / mW), and 0.00018 (mA / mW), respectively. Yes, red is the most sensitive. The control unit 31 is configured to read information on detection sensitivity characteristics of the silicon photodiode 10 a from the RAM 33.

  As shown in FIG. 4, the control unit 31 includes a laser output value as a result of gradation analysis, a reflectance of a detection target, and a red (R), green (G), and blue (B), The output current is calculated by multiplying the transmittance of the optical system and the sensitivity coefficient, and the output current of each color is added to calculate the total output current. Thereafter, the control unit 31 multiplies the total output current by the electrical analog I / V gain (40000 times) to calculate the detection expected voltage. In the normal mode, when the expected detection voltage calculated by the above procedure is smaller than a predetermined threshold value of the silicon photodiode 10a, the control unit 31 separates the silicon photo from the laser beam corresponding to the input image signal. Detection guide light for detection of the diode 10a is emitted from the red LD 61a and projected onto an arbitrary projection area. Specifically, the control unit 31 sends the detection guide light from the red LD 61a when the expected detection voltage is lower than the threshold value of the silicon photodiode 10a and the projection state does not change continuously for a predetermined time (for example, 1 minute). It is configured to control to irradiate and project onto an arbitrary projection area. In the first embodiment, the detection expected voltage of 0.74025 (V) when the gradations of R (red), G (green), and B (blue) are 80, 0, and 0, respectively, is a silicon photodiode. It is set as a predetermined threshold of 10a.

  Further, the control unit 31 has a detection sensitivity by the silicon photodiode 10a among the red LD 61a, the green LD 62a, and the blue LD 63a that is better than that of the green and blue, and among the red LD 61a, the green LD 62a, and the blue LD 63a The detection guide light is emitted from a red LD 61a that emits red laser light having a reflectance higher than that of green and blue. That is, the control unit 31 performs control to irradiate detection guide light including red laser light from the red LD 61a. In the first embodiment, the R (red) gradation of the detection guide light composed of the red laser light emitted from the red LD 61a is set to 120. That is, the expected detection voltage of the detection guide light is larger than the threshold value of the silicon photodiode 10a (the expected detection voltage when the R (red) gradation is set to 80). In addition, in the normal mode, the control unit 31 adds the laser light corresponding to the input image signal when the expected detection voltage based on the gradation of the input image signal is smaller than the threshold value of the silicon photodiode 10a. And control to project the detection guide light. The control unit 31 is configured to specify the position of the detection target based on the scanning position by the MEMS mirror 68a when the reflected light of the detection guide light by the detection target is detected by the silicon photodiode 10a. Yes. In addition, when the expected detection voltage based on the gradation of the input image signal is larger than a predetermined threshold value of the silicon photodiode 10a, the control unit 31 outputs the input image signal without projecting the detection guide light. Only the laser beam corresponding to is projected onto an arbitrary projection region, and the reflected light from the detection target of the laser beam corresponding to the input image signal is detected at the scanning position by the MEMS mirror 68a when detected by the silicon photodiode 10a. Based on this, the position of the detection target is specified.

  In the first embodiment, when the input image signal is a black image signal, the laser beam corresponding to the image signal input from any of the red LD 61a, the green LD 62a, and the blue LD 63a is not irradiated. In this case, the control unit 31 performs control to project only the detection guide light. Further, when the input image signal is an image signal of a color conforming to black such as gray, laser light corresponding to the color conforming to black is emitted from at least one of the red LD 61a, the green LD 62a, and the blue LD 63a. However, since the expected detection voltage in this case is smaller than the threshold value of the silicon photodiode 10a, the control unit 31 performs control to irradiate the detection guide light. In other words, in the present embodiment, when the reflected light from the detection target (finger or touch pen) is not obtained, or when the color is black or a color similar to black in which sufficient reflected light is difficult to obtain, the detection guide light is It is configured to be irradiated.

  The RAM 33 stores information for generating detection guide light. Based on the information stored in the RAM 33, the control unit 31 performs control so that the detection guide light is projected onto one horizontal line per frame. The control unit 31 performs control so as to change the position of the guide light for each frame. For example, as shown in FIG. 5, in the case of an 800 × 600 (pixel) projection region, the detection guide light is shifted by 10 lines (at intervals of 10 lines) from the top to the bottom among 600 horizontal lines. Project. In this way, the control unit 31 performs control for roughly searching the detection target from the top to the bottom of the entire projection area (rough search). In the first embodiment, the frame is switched every 1/60 (seconds).

  Next, with reference to FIG. 6 and FIG. 7, the position detection process in the normal mode by the control unit 31 of the projector 100 according to the first embodiment will be described.

  First, when the projector 100 is turned on, the position detection process in the normal mode is started.

  In step S1, it is determined whether or not a new image has been input to the projector 100 via the Video I / F 32 or the external I / F 34. This determination is repeated until a new image is input to the projector 100. If a new image is input to the projector 100, the process proceeds to step S2. Next, in step S2, information related to gradation is read from the image signal of the input image, and the gradation of the image signal is analyzed based on the read information.

  Next, in step S3, it is determined whether the image is a black image based on the analysis result of the gradation. If all the gradations of red, green, and blue are 0 gradations, the control unit 31 determines that the image is a black image and proceeds to step S15.

  Next, in step S4, an expected detection voltage is calculated based on the acquired laser output value, the reflectance of each color, the transmittance of the optical system of each color, and the sensitivity coefficient of each color. In step S5, the control unit 31 compares the detection expected voltage calculated from the input image signal with a predetermined threshold (0.74025 (V)) of the silicon photodiode 10a. If the detection expected voltage is greater than the predetermined threshold, it is determined that the silicon photodiode 10a can detect the laser beam corresponding to the input image signal, and the process proceeds to step S12. If the detection expected voltage is smaller than the predetermined threshold value, it is determined that the laser light corresponding to the input image signal cannot be detected by the silicon photodiode 10a, and the process proceeds to step S6.

  In step S6, it is determined whether or not the projection state in the projection area has changed for a predetermined time. If it is determined that the projection state in the projection area has not changed for a predetermined time, the process proceeds to step S7. On the other hand, when the projection state changes within a predetermined time, such as when a new image is input, the process returns to step S1.

  In step S7, the control unit 31 reads information for generating the detection guide light from the RAM 33 and generates the detection guide light. Specifically, the control unit 31 incorporates detection guide light information as image information to be projected.

  In step S <b> 8, the control unit 31 transmits the image information to be projected, to which the detection guide light is added, to the laser light source 60 via the data transmission block 40. Thereby, the detection guide light is projected onto one horizontal line in addition to the image based on the image signal input to the projection area. That is, one red horizontal line is projected on the image based on the input image signal.

  Next, in step S9, the control unit 31 changes the position of the detection guide light by 10 lines from the upper side to the lower side of the projection area for each frame. In step S10, it is determined whether or not the reflected light from the detection target object of the detection guide light is detected. This determination is repeated until the reflected light is detected. When the reflected light is detected, in step S11, the position of the detection target object in the projection region based on the timing at which the silicon photodiode 10a detects the reflected light from the detection target object and the scanning position by the MEMS mirror 68a at that time. Coordinates are specified.

  If it is determined in step S5 that the expected detection voltage is greater than the predetermined threshold value, an image corresponding to the input image signal is projected in step S12. In step S13, it is determined whether or not the reflected light from the detection target of the laser beam corresponding to the input image signal has been detected. This determination is repeated until the reflected light is detected. When the reflected light is detected, in step S14, the position of the detection target object in the projection region based on the timing at which the silicon photodiode 10a detects the reflected light from the detection target object and the scanning position by the MEMS mirror 68a at that time. Coordinates are specified.

  If it is determined in step S3 that the image is a black screen, it is determined in step S15 whether or not the projection state in the projection area has changed for a predetermined time. If it is determined that the projection state in the projection area has not changed for a predetermined time, the process proceeds to step S16. When the projection state changes within a predetermined time, such as when a new image is input, the process returns to step S1.

  In step S <b> 16, the control unit 31 reads information for generating detection guide light from the RAM 33 and generates detection guide light. In step S <b> 17, the control unit 31 performs control so that only the detection guide light is projected onto the projection area. In other words, only one red horizontal line is projected onto the black image in the projection area.

  Next, in step S18, the control unit 31 changes the position of the detection guide light by 10 lines from the upper side to the lower side of the projection area for each frame. In step S19, it is determined whether or not the reflected light from the detection target object of the detection guide light is detected. This determination is repeated until the reflected light is detected. When the reflected light is detected, in step S20, based on the timing at which the silicon photodiode 10a detects the reflected light from the detection target and the scanning position by the MEMS mirror 68a at that time, the position of the detection target in the projection region Coordinates are specified.

  In the first embodiment, as described above, when it is determined that the detection by the silicon photodiode 10a of the laser light corresponding to the input image signal cannot be expected based on the gradation of the input image signal, By projecting a control unit 31 that performs control to irradiate a laser light source 60 with a detection guide light that is different from the laser light corresponding to the image signal to be projected onto the projection area, an image having a color similar to black or black is projected. Even when the reflected light from the detection object is not obtained or difficult to obtain, the detection guide light separate from the laser beam corresponding to the input image signal is projected. Reflected light can be detected. Thereby, even when the color of the projected image is a color in which it is difficult to detect the reflected light from the detection object, the detection object can be reliably detected. Further, since the laser light source 60 that emits laser light based on the image signal for forming the projection image can be used as the detection guide light generation unit, the generation unit dedicated to the detection guide light, such as an infrared generation unit There is no need to provide. As a result, the configuration of the projector 100 can be simplified.

  In the first embodiment, as described above, the detection expected voltage is acquired based on the gradation of the image signal, and when the acquired detection expected voltage is smaller than a predetermined threshold, the detection guide light is emitted from the red LD 61a. By configuring the control unit 31 to control the projection onto the projection area, the detection guide light emitted from the red LD 61a even when the expected detection voltage based on the gradation of the image signal is smaller than a predetermined threshold value It is possible to reliably detect the detection object using the reflected light.

  In the first embodiment, as described above, when the expected detection voltage is smaller than the predetermined threshold and the projection state does not change for a predetermined time, control is performed to irradiate the detection guide light from the red LD 61a. By configuring the control unit 31, the detection guide light is emitted from the red LD 61a only when the detection expected voltage is lower than a predetermined threshold value and detection by the silicon photodiode 10a cannot be expected for a predetermined time. Therefore, it is possible to suppress the occurrence of noise or the like due to the detection guide light in the image based on the input image signal as much as possible.

  In the first embodiment, as described above, when the detection expected voltage is equal to or higher than a predetermined threshold, the reflected light from the detection target of the laser light corresponding to the input image signal is not projected without projecting the detection guide light. By configuring the control unit 31 to perform control for specifying the position of the detection target based on the detection result of the above, the detection guide light is not used when the detection expected value is equal to or greater than a predetermined threshold. Since the position of the detection target is specified using the laser beam corresponding to the input image signal, it is possible to suppress the occurrence of noise caused by the detection guide light in the image based on the input image signal as much as possible. it can.

  In the first embodiment, as described above, the position of the detection target is specified based on the scanning position of the detection guide light by the projection unit when the reflected light of the detection guide light by the detection target is detected. By configuring the control unit 31, it is easy to detect the reflected light of the laser light corresponding to the image signal based on the reflected light of the detection guide light by the detection target and the scanning position of the detected guide light. In addition, the position of the detection object can be specified.

  In the first embodiment, as described above, when the image signal is black or an image signal having a color similar to black, control for projecting the detection guide light different from the laser light corresponding to the image signal onto the projection region is performed. By configuring the control unit 31 to perform the detection, the detection guide light is used even when the reflected light from the detection target is not obtained or is difficult to obtain, even when a black or similar color image is projected onto the projection region. Thus, the detection object can be reliably detected.

  In the first embodiment, as described above, the laser light source 60 including the red LD 61a that emits red laser light, the green LD 62a that emits green laser light, and the blue LD 63a that emits blue laser light is provided. At the same time, the control unit 31 is configured to perform control to irradiate the detection guide light from the red LD 61a that generates red laser light having a high reflectance of the detection target among the red LD 61a, the green LD 62a, and the blue LD 63a. Therefore, the detection guide light can be configured by the red laser light having a high reflectance of the detection target, and the reflected light of the detection guide light from the detection target can be accurately detected by the silicon photodiode 10a. .

  In the first embodiment, as described above, the silicon photodiode 10a has a detection sensitivity of red laser light better than that of green and blue laser light, and the red LD 61a emits red detection guide light. By configuring the control unit 31 to perform the control, the red laser light having the highest reflectance from the detection target and the highest detection sensitivity is irradiated as the detection guide light, and thus the silicon photodiode 10a. Thus, the reflected light of the detection guide light composed of red laser light can be detected with high accuracy.

  In the first embodiment, as described above, the control unit 31 performs control to change the position of the detection guide light within an arbitrary projection area for each image display frame based on the analysis result of the gradation of the image signal. Since the position of the detection guide light is changed in the projection region for each image display frame, the detection target can be reliably detected regardless of the position of the detection target in the projection region.

(Second Embodiment)
The projector 100 (see FIG. 1) according to the second embodiment of the present invention will be described below with reference to FIG.

  In the second embodiment, unlike the first embodiment described above, the control unit 31 projects the detection guide light for detection in the energy saving mode in which the projector 100 stands by with reduced power consumption. explain.

  When the energy saving mode is continued for a predetermined time (for example, 1 minute), the control unit 31 performs control to irradiate the detection guide light from the red LD 61a and project it onto an arbitrary projection area when the energy saving mode is continued for a predetermined time (for example, 1 minute). Configured to do. In the energy saving mode, since an image based on the input image signal is not projected on the projection area, the control unit 31 performs control to project only the detection guide light. Further, in the energy saving mode, the control unit 31 performs control for returning the projector 100 from the energy saving mode to the normal mode when the reflected light of the detection guide light from the detection target is detected by the silicon photodiode 10a. It is configured.

  Next, with reference to FIG. 8, a description will be given of the system recovery process in the energy saving mode by the control unit 31 of the projector 100 according to the second embodiment.

  In step S21, it is determined whether the energy saving mode is set. When the control unit 31 determines that the projector 100 is not in the energy saving mode, the control unit 31 executes position detection processing in the normal mode (see FIGS. 6 and 7).

  In step S22, it is determined whether or not the energy saving mode is continued for a predetermined time. The determinations in step S21 and step S22 are repeated until the predetermined time has elapsed. When the energy saving mode is continued for a predetermined time, in step S23, the control unit 31 reads information for generating the detection guide light from the RAM 33 and generates the detection guide light. In step S24, the control unit 31 performs control so that only the detection guide light is projected onto the projection area. That is, only one red horizontal line is projected onto the projection area.

  Next, in step S25, the control unit 31 changes the position of the detection guide light by 10 lines from the upper side to the lower side of the projection area for each frame. In step S26, it is determined whether or not the reflected light from the detection object of the detection guide light has been detected. This determination is repeated until the reflected light is detected. When the reflected light is detected, in step S27, the control unit 31 returns the projector 100 from the energy saving mode to the normal mode.

  In addition, the other structure of 2nd Embodiment is the same as that of the said 1st Embodiment.

  In the second embodiment, as described above, in the normal mode, when it is determined that the detection of the laser beam corresponding to the image signal cannot be expected based on the gradation of the image signal, the detection guide light is projected onto the projection area. In the case of the energy saving mode, the control unit 31 is configured to control the projection of the detection guide light onto the projection area when the energy saving mode is continued for a predetermined time. Even in the energy saving mode in which an image based on the image signal to be projected is not projected, the detection target object can be reliably detected using the detection guide light.

  In the second embodiment, as described above, when the laser light corresponding to the image signal is projected in the normal mode, the detection guide light is projected in addition to the laser light corresponding to the image signal, and the energy-saving mode is also projected. In this case, by configuring the control unit 31 to perform control to project only the detection guide light, in the normal mode, the detection guide light is projected in a state in which an image based on the image signal is projected. In the energy saving mode, only the detection guide light can be projected to detect the detection object.

  In the second embodiment, as described above, when the reflected light from the detection target light of the detection guide light is detected by the silicon photodiode 10a in the energy saving mode, the control unit 31 is normally set in the energy saving mode. It is configured to perform control to return to the mode. With this configuration, in the energy saving mode, the user can easily return the projector 100 from the normal mode to the energy saving mode simply by placing the detection target in the projection area.

  The remaining effects of the second embodiment are similar to those of the aforementioned first embodiment.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is shown not by the above description of the embodiments but by the scope of claims for patent, and further includes all modifications within the meaning and scope equivalent to the scope of claims for patent.

  In the first and second embodiments, the example in which the color information of the present invention is gradation is shown, but the present invention is not limited to this. In the present invention, color information other than gradation may be used.

  In the first and second embodiments, the example in which the detection guide light is projected based on the detection expected voltage as the detection expected value calculated from the analysis result of the color information has been shown, but the present invention is not limited to this. In the present invention, when it is determined that the detection of the reflected light by the detection target of the laser beam corresponding to the input image signal cannot be expected based on the color information (gradation) without using the detection expected value, Detection guide light may be projected.

  In the said 1st and 2nd embodiment, although the silicon photodiode as a photon detection part showed the example which has a threshold value (0.74025 (V)), this invention is not limited to this. In the present invention, a threshold value other than 0.74025 (V) may be used.

  In the said 1st and 2nd embodiment, although the silicon photodiode was shown as an example of a photon detection part, this invention is not limited to this. In the present invention, a light detection unit other than a silicon photodiode may be used.

  In the first and second embodiments, the example in which the red laser light is emitted from the red LD (red laser light generation unit) as the detection guide light has been shown, but the present invention is not limited to this. In the present invention, laser light of a color other than red may be irradiated as detection guide light. For example, green laser light having the next highest reflectance after red and silicon photodiode having high detection sensitivity may be used as detection guide light, or a mixed color of red and green may be used as detection guide light. Good. Further, the detection guide light may be emitted from the blue laser light generation unit, or the detection guide light is combined by combining two or more of the red laser light generation unit, the green laser light generation unit, and the blue laser light generation unit. It may be irradiated.

  In the said 1st and 2nd embodiment, although the example which projects on one horizontal line toward the downward direction from the upper direction of the flame | frame was shown, this invention is not limited to this. In the present invention, the detection guide light may be projected onto a vertical line from the left side to the right side (or from the right side to the left side) of the frame, or the detection guide light may be projected onto an oblique line. Further, the detection guide light may be projected by combining horizontal lines, vertical lines, and diagonal lines.

  In the first and second embodiments, the example in which one frame is projected onto one horizontal line has been shown, but the present invention is not limited to this. In the present invention, a plurality of detection guide lights may be projected per frame.

  In the first and second embodiments, the example in which the detection guide light is projected for each continuous frame is shown, but the present invention is not limited to this. In the present invention, the detection guide light may be projected, for example, every other frame (every two frames) or every arbitrary frame. If comprised in this way, it can suppress as much as possible that the noise resulting from a detection guide light generate | occur | produces by projecting a detection guide light for every several frames instead of every frame. As a result, it is possible to suppress the occurrence of screen flicker as much as possible.

  In the first and second embodiments, the example in which the detection guide light is projected onto one horizontal line is shown, but the present invention is not limited to this. In the present invention, for example, the detection guide light may be projected onto a predetermined area and the area may be moved for each frame.

  In the first and second embodiments, the example in which the detection guide light is projected when there is no change in the projection state for one minute as the predetermined time is shown, but the present invention is not limited to this. In the present invention, the detection guide light may be projected when there is no change in the time projection state for less than one minute or longer than one minute.

  In the first and second embodiments, an example in which one frame of the projection area has a resolution of 800 × 600 (pixels) is shown, but the present invention is not limited to this. In the present invention, a resolution other than 800 × 600 (pixels) may be used.

  In the first and second embodiments, for convenience of explanation, the processing operation of the control unit is described in an event-driven manner at the start, and the processing operations after the start are described using a flowchart described in a flow-driven manner. The present invention is not limited to this. The processing operation of the control unit may be performed by a complete event drive type, may be performed by a complete flow drive type, or may be performed in parallel processing.

  In the first and second embodiments, the example in which the present invention is applied to a projector (projector dedicated machine) has been described. However, the present invention is not limited to this. The present invention may be applied to an electronic device having a projector function other than a projector (a projector dedicated machine). For example, the present invention may be applied to a mobile device (such as a mobile information terminal and a mobile phone) having a projector function.

10a Silicon photodiode (light detector)
31 control unit 60 laser light source (laser light generation unit)
61a Red LD (Red laser beam generator)
62a Green LD (Green laser beam generator)
63a Blue LD (Blue laser beam generator)
68a MEMS mirror (projection unit)
100 Projector (electronic equipment having a projector function)

Claims (8)

A laser beam generator for emitting a laser beam based on an image signal;
A projection unit for projecting the laser beam;
A light detection unit for detecting the laser light reflected from the detection object;
Based on the voltage corresponding to the color information included in the image signal, the voltage is rather smaller than a predetermined threshold and, if a predetermined time continues to the projection state does not change, the reflected light than the predetermined threshold value A projector comprising: a control unit that performs control to emit laser light having a large corresponding voltage. Based on the voltage corresponding to the color information included in the image signal, the control unit, when the voltage is equal to or higher than the predetermined threshold, without projecting laser light having a large voltage corresponding to the reflected light, The projector according to claim 1, wherein the projector is configured to perform control for specifying a position of a detection target based on a detection result of reflected light of a laser beam corresponding to the image signal. The laser beam generator includes a red laser beam generator that emits red laser beam, a green laser beam generator that emits green laser beam, and a blue laser beam generator that emits blue laser beam. With
The control unit includes at least one laser beam generator that generates a laser beam having a high reflectance of the detection object among the red laser beam generator, the green laser beam generator, and the blue laser beam generator. the voltage corresponding to the reflected light is configured to perform control of emitting a large laser beam projector according to claim 1 or 2. The laser beam generator includes a red laser beam generator that emits red laser beam, a green laser beam generator that emits green laser beam, and a blue laser beam generator that emits blue laser beam. With
The light detection unit has a characteristic in which the detection sensitivity differs depending on the wavelength of the laser light to be detected,
The control unit generates at least one laser beam having a wavelength with good detection sensitivity by the light detection unit among the red laser beam generation unit, the green laser beam generation unit, and the blue laser beam generation unit. from the generation unit, the is configured to perform control for emitting a large laser beam voltage corresponding to the reflected light, the projector according to any one of claims 1-3. The light detection unit includes a light detection unit in which the detection sensitivity of red laser light is better than the detection sensitivity of green and blue laser light,
Wherein the control unit is configured and the red laser light generator is configured to perform a control which emits a red laser beam voltage greater that the corresponding reflected light composed of laser beams, according to claim 3 or 4 projector. In the normal mode, the control unit emits a laser beam having a large voltage corresponding to the reflected light when the voltage is smaller than the predetermined threshold based on a voltage corresponding to color information included in the image signal. In the energy saving mode in which an image based on the image signal is not projected, a laser beam having a large voltage corresponding to the reflected light is emitted when the energy saving mode is continued for a predetermined time. It is configured to perform the control, the projector according to any one of claims 1-5. When projecting laser light corresponding to the image signal in the normal mode, the control unit projects laser light having a large voltage corresponding to the reflected light in addition to the laser light corresponding to the image signal. The projector according to claim 6 , wherein in the energy saving mode, control is performed to project only laser light having a large voltage corresponding to the reflected light. In the energy saving mode, the control unit returns from the energy saving mode to the normal mode when the light detection unit detects reflected light of laser light having a large voltage corresponding to the reflected light. It is configured to perform control, projector according to claim 6 or 7.

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