JP4883332B2 - Projection display device - Google Patents

Description

  The present invention relates to a projection display apparatus such as a liquid crystal projector.

  This type of projection display apparatus includes distance detection means for detecting the distance between the person in the image projected by the projection means and the projection display apparatus, and the distance detection means allows the person to display the projection image display. Only when it detects that it is in the vicinity of the device, there is one that adjusts the amount of light projected so as not to dazzle people. This distance detection means is constituted by a light receiving element (light sensor), and estimates the distance between the person and the projection display apparatus based on the amount of light reflected from the person received by the light receiving element (see, for example, Patent Document 1).

JP-A-6-347748

  However, in the image projected by the projection means, even when a person is away from the projection display apparatus, it is dazzling when the person looks at the projection display apparatus. In the configuration in which the amount of projection light is adjusted only when in the vicinity of the video display device, there is a problem that a person feels uncomfortable with the projection light.

  In addition, the distance between the projection display apparatus and the screen differs depending on the room layout in which the projection display apparatus is used, and the distance between the projection display apparatus and the screen has become extremely short due to room circumstances. In some cases, the amount of received light detected by the light receiving element may increase even when there is no person in the image projected by the projection means. As a result, even if there is no person in the image projected by the projection means, if there is a person in the vicinity of the projection display apparatus, the sensor erroneously detects and the projected light quantity is adjusted, and the image is viewed. There has been a problem that people feel uncomfortable due to unexpected changes in the amount of projected light.

  Accordingly, the present invention has been made to solve such a problem, and does not cause discomfort to those who are in the projected image, and does not cause discomfort to those who are viewing the image. It is an object to provide an apparatus.

  Means for solving the above problems include a projection unit that projects an image of light emitted from a light source via a display device, an enlargement / reduction function that enlarges or reduces the projected image, and a projection from the projection unit. In a projection display apparatus comprising: a human detection unit that detects a person located in a projected image; and a control unit that changes a projected video state when the human detection unit detects the presence of a person. The human detection means is covered with a cylindrical body movable in the front-rear direction of the projection unit, and the human detection means detects by moving the cylindrical body according to a change in the projection range of the image by the enlargement / reduction function. The range to be adjusted is configured to be adjustable.

  According to the configuration of the first aspect of the present invention, the range in which the human detection sensor 42 detects a person can be adjusted in accordance with the change in the projection range of the image.

1 is an external perspective view of a liquid crystal projector according to a first embodiment of the present invention. It is the block diagram which showed the optical system of the liquid crystal projector. It is a top view which shows the use condition of the liquid crystal projector. It is the block diagram which showed the signal processing system of the liquid crystal projector. It is a front view of the screen of the liquid crystal projector. It is the block diagram which showed the signal processing system of another form of the liquid crystal projector. It is a front view of the state which displayed the timer on the screen of the liquid crystal projector. It is the block diagram which showed the optical system of the liquid crystal projector of 2nd Embodiment of this invention. It is a top view which shows the use condition of the liquid crystal projector. It is a block diagram of the human detection sensor of the liquid crystal projector, and shows a state where the cylinder is moved forward. It is a block diagram of the human detection sensor of the liquid crystal projector, and shows a state where the cylinder is moved backward.

(First embodiment)
The projection display apparatus according to the first embodiment of the present invention will be described in detail below with reference to FIGS.

  As shown in FIGS. 1 and 2, the projection display apparatus according to the first embodiment shows a three-plate liquid crystal projector 30 as an example. In the main body case 41 of the liquid crystal projector 30, an optical system 42 from the light source 1 described later to the projection lens 16 is disposed.

  FIG. 2 shows an optical system 42 disposed in the main body case 41. The light emitting unit in the light source 1 is composed of an ultra-high pressure mercury lamp, a metal halide lamp, a xenon lamp or the like, and the irradiation light is emitted as parallel light by the parabolic reflector 2 and guided to the integrator lens 4.

  The integrator lens 4 is composed of a pair of lens groups (fly eye lenses) 4a and 4b, and each lens portion guides light emitted from the light source 1 to the entire surfaces of liquid crystal light valves 31, 32, and 33 described later. Thus, the partial luminance unevenness existing in the light source 1 is averaged, and the light amount difference between the center of the screen and the peripheral portion is reduced. The light passing through the integrator lens 4 is guided to the first dichroic mirror 7 after passing through the polarization conversion device 5 and the condenser lens 6.

  The first dichroic mirror 7 transmits light in the red wavelength band and reflects light in the cyan (green + blue) wavelength band. The light in the red wavelength band that has passed through the first dichroic mirror 7 is reflected by the reflection mirror 8 to change the optical path. The red light reflected by the reflection mirror 8 is light-modulated by passing through a lens 9 and a transmissive liquid crystal light valve 31 for red light. The light in the cyan wavelength band reflected by the first dichroic mirror 7 is guided to the second dichroic mirror 10.

  The second dichroic mirror 10 transmits light in the blue wavelength band and reflects light in the green wavelength band. The light in the green wavelength band reflected by the second dichroic mirror 10 is guided to the transmissive liquid crystal light valve 32 for green light through the lens 11 and is modulated by being transmitted therethrough. The light in the blue wavelength band that has passed through the second dichroic mirror 10 is guided to the blue-light transmissive liquid crystal light valve 33 through the total reflection mirror 12, total reflection mirror 13, and lens 14, and is transmitted therethrough. It is optically modulated.

  Each of the liquid crystal light valves 31, 32, 33 includes a panel portion 31b, in which liquid crystal is sealed between an incident-side polarizing plate 31a, 32a, 33a and a pair of glass substrates (with pixel electrodes and alignment films formed). 32b and 33b and output side polarizing plates 31c, 32c and 33c.

  The modulated light (each color video light) modulated by passing through the liquid crystal light valves 31, 32, 33 is synthesized by the cross dichroic prism 15 to become color video light. The color image light is enlarged and projected by the projection lens 16 and displayed on the screen 40 (see FIG. 3).

  As shown in FIG. 1, a person detection sensor 43 as a person detection means for detecting the presence of a person is disposed on the front surface of a main body case 41 of the liquid crystal projector 30. The human detection sensor 43 is composed of a pyroelectric infrared sensor and incorporates a timer circuit. Further, the range in which the human detection sensor 43 detects a person is set to substantially match the range of the image projected from the projection lens 16 as shown in FIG.

  The control of the first embodiment of the present invention will be described in detail based on the block diagram of signal processing shown in FIG.

  In FIG. 4, analog video signals from video, personal computers, etc. are input to the input terminals, and these video signals are converted from analog to digital video signals by the ADC circuit 44. This digitized video signal is sent to the video signal processing circuit 45. The video signal processing circuit 45 has a function of superimposing an OSD (On Screen Display) stored in the flash memory in accordance with an instruction from the microcomputer 46, which is a CPU, and converting the color of the video signal. The video signal supplied from the video processing signal circuit 45 is converted from digital to analog by the DAC circuit 47. The video signal supplied by the DAC circuit 47 displays the image on the liquid crystal panel drive 48 (liquid crystal panels 31, 32, 33). The image is projected by the light source 1 to be a projected image and projected onto the screen 40 via the projection lens 16.

When the human detection sensor 43 detects that a person is present, the human detection sensor 43 outputs an HI level to the I / O port of the microcomputer 46 for a predetermined time. Further, when the human detection sensor 43 detects that there is no person, it outputs an LO level to the I / O port of the microcomputer 46.

  As shown in FIG. 5, when a person 51 is present in the projected image of the liquid crystal projector 30, the person detection sensor 43 detects the presence of the person 51, and the microcomputer 46 as the control unit uses the video signal processing circuit 45 to output a video signal Is superimposed on black. As a result, since the image of the projection light is black, it is possible to reduce glare to the person 51 in the projection image.

  Further, when the human detection sensor 43 detects a person in the projected image, the microcomputer 46 may reduce the illuminance of the image. Even with this configuration, it is possible to reduce glare to a person in the projected image. As a method of reducing the illuminance of the image, a method of reducing the illuminance of the light source 1 by reducing the voltage applied to the light source 1, and reducing the illuminance from the light source 1 by operating a diaphragm mechanism (not shown) provided in the optical system 42. A method for reducing the illuminance from the light source 1 by operating the shutter mechanism 6 provided between the optical system 42 and the screen 40 as shown in FIG.

  When the human detection sensor 43 detects a person in the projected image and changes the projected image state, the microcomputer 46 measures the time, and the time is displayed on the screen 40 as shown in FIG. The timer display 49 is displayed and the timer display 49 is turned off after a predetermined time when the timer measurement ends to restore the video state to the original state. With this configuration, it is possible to easily check the time until the video state returns to the original state. In the first embodiment of the present invention, the timer display 49 is set to 30 seconds (countdown from 30 to 0). In addition, since the video is restored to the original state after a predetermined time has elapsed since the video state was changed, the person who was watching the video can view the video in the optimum state again.

  In the first embodiment of the present invention, the human detection sensor is an infrared sensor. However, the present invention is not limited to this configuration. For example, a configuration may be adopted in which the presence of a person is detected by detecting a difference in reflection pattern depending on the presence or absence of the person using an ultrasonic sensor. In addition, any sensor that can detect a person may be used.

  Further, in the first embodiment of the present invention, when the human detection sensor 43 detects the presence of a person, the illuminance of the video is reduced. However, a preset OSD may be displayed on the screen 40.

  In the first embodiment of the present invention, the shutter mechanism 6 is provided between the optical system 42 and the screen 40 to reduce the illuminance from the light source 1. However, the shutter mechanism 6 is disposed in the optical system 42. It may be configured.

  In the first embodiment of the present invention, a liquid crystal projector using a liquid crystal display panel is shown. However, the present invention can also be applied to a projection type video display device having another video light generation system. In addition to the front projection type, the present invention can be applied to a rear projection type image display device. The present invention can also be applied to a projector of a DLP (Digital Light Processing) (registered trademark of Texas Instruments (TI)) system.

(Second Embodiment)
8 to 11 show a second embodiment of the present invention. The same components as those in the first embodiment are denoted by the same reference numerals and description thereof is omitted.

  Although the projection lens 16 is fixed in the first embodiment, the projection lens 16 of the second embodiment includes a lens driving motor 22 that moves the projection lens 16 in the front-rear direction in order to enlarge or reduce the projected image. It has a configuration with. As shown in FIGS. 10 and 11, the human detection sensor 43 is covered with a cylindrical body 50, and the cylindrical body 50 is movable in the front-rear direction by a driving means (not shown).

  As shown in FIG. 9, the range of the image projected on the screen 40 changes as the projection lens 16 moves back and forth. Accordingly, if the range in which the human detection sensor 42 detects the presence of a person is constant, for example, when the projection image range is widened by driving the lens driving motor 22, even if there is a person in the widened projection image. The presence of the person cannot be detected by the person detection sensor 42, and the person may feel uncomfortable due to the projection light.

  On the other hand, in the second embodiment of the present invention, the human detection sensor 42 is configured to be able to adjust the range in which a person is detected. As shown in FIGS. The range in which the human detection sensor 42 detects a person is adjusted.

  In FIG. 9, when the lens driving motor 22 is driven to widen the projected image range from A to B, the range in which the human detection sensor 42 detects a person by moving the cylinder 50 rearward is projected from A ′. The range is expanded to B ′ substantially equal to the range B. At this time, the movement amount of the cylindrical body 50 is adjusted according to the number of rotations of the lens driving motor 22, that is, the movement amount of the projection lens 16 by the lens driving motor 22. As a result, the range in which the human detection sensor 42 detects a person can be adjusted according to the change in the projection range of the video, and the person in the projection video range can be reliably detected.

  In the second embodiment, the range in which the human detection sensor 42 detects a person can be adjusted by moving the cylinder 50 covering the human detection sensor 42 back and forth. However, the human detection sensor 42 is moved back and forth. By doing so, the range in which the human detection sensor 42 detects a person may be adjustable.

1 Light source 31 Liquid crystal light valve (display device)
32 Liquid crystal light valve (display device)
33 Liquid crystal light valve (display device)
43 Person detection sensor (person detection means)
46 Microcomputer (control means)

Claims (1)

A projection unit for projecting an image of light emitted from a light source via a display device;
An enlargement / reduction function for enlarging or reducing the projected image;
Human detection means for detecting a person located in the image projected from the projection unit;
Control means for changing the projected image state when the person detecting means detects the presence of a person;
In a projection display apparatus comprising:
The human detection means is covered with a cylindrical body movable in the front-rear direction of the projection unit, and the human detection means detects by moving the cylindrical body according to a change in the projection range of the image by the enlargement / reduction function. A projection display apparatus characterized in that the range can be adjusted .

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