JP2012242457A - Projection type display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a projection type display device capable of simply adjusting a state of video light emitted to a surface to be projected.SOLUTION: A projector 1 includes: a light source lamp 201; liquid crystal panels 211, 213, 216 for modulating light from the light source lamp 201 and generating video light; a projection lens unit 30 for projecting the video light generated by the liquid crystal panels 211, 213, 216 on a surface to be projected; an illuminance sensor 401 which is arranged at a peripheral position of an emission port of the projection lens unit 30 and detects the video light emitted from the projection lens unit 30; and a CPU 501 and a panel drive circuit 507 for adjusting brightness of the video light on the basis of the detection result of the illuminance sensor 401.

Description

  The present invention relates to a projection display device that modulates light from a light source and projects the light onto a projection surface.

  A projection display device (hereinafter referred to as “projector”) modulates light from a light source with a light modulation element, and projects the modulated light (hereinafter referred to as “video light”) onto a projection surface such as a screen.

  In such a projector, a usage pattern in which one image is projected onto a large screen using a plurality of projectors may be employed (see FIG. 6). In this case, the entire image to be projected is divided into the number of projectors. Each projector projects an image of a corresponding divided area. The above usage pattern is hereinafter referred to as “multi-screen projection”.

  The performance of component parts such as a light source and a light modulation element varies between projectors, so that the state of video light output from each projector, for example, luminance and chromaticity varies. For this reason, when multi-screen projection is performed, it is necessary to adjust the state of the image light for each projector so as to suppress variation in the state of the image light among the projectors.

  Therefore, a configuration may be adopted in which the image light output from each projector is detected by an optical sensor and the state of the image light is adjusted based on the detection result. For example, the optical sensor can be arranged at a boundary position between two divided regions on the screen (see Patent Document 1).

WO99 / 53693 Publication (Republication Publication)

  In the case where the optical sensor is arranged on the screen as in the above configuration, the work of installing the plurality of projectors and further arranging the optical sensor on the screen and connecting the optical sensor and the projector is performed. Necessary. For this reason, adjustment work when performing multi-screen projection tends to be complicated.

  SUMMARY An advantage of some aspects of the invention is that it provides a projection display device that can easily adjust the state of image light emitted to a projection surface.

  The projection display device of the present invention includes a light source, a light modulation unit that modulates light from the light source to generate image light, and a projection that projects the image light generated by the light modulation unit onto a projection surface. And a light detection unit that is disposed at a peripheral position of the exit of the projection unit and detects the image light emitted from the projection unit, and the state of the image light based on a detection result of the light detection unit An adjustment unit for adjustment.

  According to the projection display apparatus of the present invention, it is not necessary to arrange a light detection unit on the projection surface in order to detect the state of the image light emitted to the projection surface, for example, the luminance or chromaticity. Become. Therefore, adjustment work can be easily performed when adjusting the state of the image light, such as using a projection display device for multi-screen projection.

  In the projection display device according to the aspect of the invention, the light detection unit is disposed at a position that does not enter the optical path of the image light emitted from the projection unit, and detects the light leaking from the optical path, thereby detecting the image light. May be configured to be indirectly detected.

  With such a configuration, it is possible to prevent a part of the image light emitted from the projection unit from being blocked by the light detection unit. Therefore, it is possible to prevent the image quality from being deteriorated due to the image light being blocked.

  In the projection display device according to the aspect of the invention, the light detection unit may be disposed such that a light receiving surface thereof faces a direction of an optical path of the image light.

  With such a configuration, the light leaking from the optical path of the image light can be received efficiently, so that good detection can be performed by the light detection unit.

  The projection display device according to the present invention may be configured to include an opaque holder that is disposed around the emission port and accommodates the light detection unit. In this case, the holder has an opening that covers the periphery of the light detection unit and opens the light receiving surface of the light detection unit to the outside, and the opening is disposed so as to face the optical path of the image light. .

  With such a configuration, since the light detection unit is accommodated in the opaque holder, stray light unnecessary for light detection can be prevented from entering the light detection unit. Therefore, the detection accuracy of image light can be increased.

  In the projection display device of the present invention, the light detection unit may be an illuminance sensor. In this case, the adjustment unit adjusts the luminance of the image light emitted from the projection unit based on the illuminance detected by the illuminance sensor.

  With such a configuration, the adjustment work can be performed satisfactorily when adjusting the luminance of the image light.

  As described above, according to the present invention, it is possible to provide a projection display device that can satisfactorily adjust the state of image light emitted to a projection surface.

  The effects and significance of the present invention will become more apparent from the following description of embodiments. However, the following embodiment is merely an example when the present invention is implemented, and the present invention is not limited to what is described in the following embodiment.

It is a figure which shows the structure of the projector which concerns on embodiment. It is a figure which shows the structure of the optical engine which concerns on embodiment. It is a figure which shows the structure of the projection lens unit and sensor unit which concern on embodiment. It is a figure which shows the structure of the circuit system of the projector which concerns on embodiment. It is a flowchart which shows the operation | movement of the brightness adjustment process for adjusting the brightness | luminance of the projection light (video light) output from the projector which concerns on embodiment. It is a figure which shows the state in which multi-screen projection is performed using a some projector. It is a figure for demonstrating the projector which concerns on the example of a change.

  Hereinafter, a projector according to an embodiment will be described with reference to the drawings.

  FIG. 1 is a diagram showing a configuration of the projector 1. Referring to FIG. 1, projector 1 includes a horizontally-long substantially rectangular parallelepiped cabinet 10 that is a casing. In the cabinet 10, a projection window 101 is formed on the left side of the front surface, and exhaust ports 102 and 103 for exhausting air from inside the cabinet 10 are formed on the right side and the right side surface of the front surface, respectively. An operation unit 104 is provided on the upper surface of the cabinet 10. The operation unit 104 is provided with a plurality of operation keys.

  An optical engine 20 and a projection lens unit 30 are arranged inside the cabinet 10. The optical engine 20 generates image light modulated based on the image signal. A projection lens unit 30 is attached to the optical engine 20, and a front end portion of the projection lens unit 30 is exposed forward from the projection window 101. The projection lens unit 30 enlarges and projects the image light generated by the optical engine 20 onto a screen surface arranged in front of the projector 1. A sensor unit 40 is disposed near the exit of the projection lens unit 30. The configuration of the sensor unit 40 will be described in detail later.

  FIG. 2 is a diagram showing a configuration of the optical engine 20.

  The light source lamp 201 includes a light emitter that emits white light and a reflector that reflects light emitted from the light emitter. As the light emitter, for example, a mercury lamp, an ultrahigh pressure mercury lamp, or a metal halide lamp is used.

  White light emitted from the light source lamp 201 passes through the fly eye integrator 202, the PBS array 203, and the condenser lens 204. The fly eye integrator 202 is composed of a pair of lenses 202a and 202b, and each lens 202a and 202b is composed of a large number of small lenses arranged in a grid pattern. The light incident on the fly eye integrator 202 is divided by these small lenses. Each of the divided lights is superimposed on a liquid crystal panel (described later) by a condenser lens 204. Thereby, the light quantity distribution of the light irradiated to the liquid crystal panel is made uniform. Each light split by the fly eye integrator 202 is aligned in one direction by the PBS array 203.

  The light that has passed through the condenser lens 204 enters the dichroic mirror 205. Of the incident light, the dichroic mirror 205 transmits red wavelength band light (hereinafter referred to as “R light”) and green wavelength band (hereinafter referred to as “G light”), and a blue wavelength band (hereinafter referred to as “B light”). Light).

  The R light and G light transmitted through the dichroic mirror 205 enter the dichroic mirror 206. The dichroic mirror 206 transmits R light and reflects G light.

  The R light transmitted through the dichroic mirror 206 is guided to the condenser lens 210 by the relay lens 207 and the reflection mirrors 208 and 209, passes through the condenser lens 210, and is irradiated on the liquid crystal panel 211. The liquid crystal panel 211 is driven according to the video signal for red and modulates the R light according to the driving state. An incident side polarizing plate (not shown) is disposed on the incident side of the liquid crystal panel 211, and the R light is irradiated to the liquid crystal panel 211 through the incident side polarizing plate. Further, an output side polarizing plate (not shown) is arranged on the output side of the liquid crystal panel 211, and the R light emitted from the liquid crystal panel 211 enters the output side polarizing plate.

The G light reflected by the dichroic mirror 206 passes through the condenser lens 212 and is irradiated on the liquid crystal panel 213. The liquid crystal panel 213 is driven according to the green video signal, and modulates the G light according to the driving state. An incident side polarizing plate (not shown) is arranged on the incident side of the liquid crystal panel 213, and G light is irradiated to the liquid crystal panel 213 through the incident side polarizing plate. Further, an output side polarizing plate (not shown) is disposed on the output side of the liquid crystal panel 213, and the G light emitted from the liquid crystal panel 213 enters the output side polarizing plate.

  The B light reflected by the dichroic mirror 205 is guided to the condenser lens 215 by the reflecting mirror 214, passes through the condenser lens 215, and is irradiated on the liquid crystal panel 216. The liquid crystal panel 216 is driven according to the blue video signal, and modulates the B light according to the driving state. An incident side polarizing plate (not shown) is disposed on the incident side of the liquid crystal panel 216, and the liquid crystal panel 216 is irradiated with B light through the incident side polarizing plate. Further, an output side polarizing plate (not shown) is disposed on the output side of the liquid crystal panel 216, and the B light emitted from the liquid crystal panel 216 enters the output side polarizing plate.

  The R light, G light, and B light modulated by the liquid crystal panels 211, 213, and 216 and emitted from the output side polarizing plate enter the dichroic prism 217. The dichroic prism 217 reflects R light and B light out of R light, G light, and B light and transmits G light, thereby color-combining the B light, G light, and R light. Thus, the color-combined video light is emitted from the dichroic prism 217 toward the projection lens unit 30.

  In addition to the transmissive liquid crystal panels 211, 213, and 216, a reflective liquid crystal panel or a MEMS device can be used as the light modulation element that constitutes the optical engine 20. Further, the optical engine 20 may be configured by a single plate type optical system using one light modulation element and a color wheel, for example, instead of the three plate type optical system including the three light modulation elements as described above. it can.

  FIG. 3 is a diagram illustrating the configuration of the projection lens unit 30 and the sensor unit 40, and is a longitudinal sectional view of the periphery of the projection lens unit 30 in the projector 1.

  The projection lens unit 30 includes a plurality of lenses including a front lens 302 in a housing 301. The image light incident on the projection lens unit 30 is emitted from the front lens 302 toward the screen as projection light.

  The sensor unit 40 includes an illuminance sensor 401 and a holder 402 for holding the illuminance sensor 401 at a position around the exit of the projection lens unit 30.

  The illuminance sensor 401 is held by the holder 402, and is disposed in the vicinity of the optical path of the projection light emitted from the projection lens unit 30 and not on the optical path. The illuminance sensor 401 indirectly detects the light amount of the projection light by detecting the light amount of leakage light emitted toward the surroundings from the optical path of the projection light. The illuminance sensor 401 outputs a current signal corresponding to the amount of received light, that is, the illuminance of the irradiated light. The higher the brightness of the projection light, the greater the amount of leakage light, so the amount of light received by the illuminance sensor 401 increases.

  The illuminance sensor 401 is accommodated in the holder 402 so that its light receiving surface 401a faces in a direction P substantially perpendicular to the optical axis L of the projection lens unit 30, that is, in the direction of the optical path of the projection light. Has been.

An opening 402 a is formed in the holder 402. The opening 402a faces the direction of the optical path of the projection light, and leakage light is taken into the illuminance sensor 401 through the opening 402a. The holder 402 is made of an opaque material and blocks light from other than the opening 402a, that is, stray light unnecessary for detection by the illuminance sensor 401. Therefore, the detection accuracy of leakage light by the illuminance sensor 401 is improved.

  The holder 402 is fixed to the front end portion of the cabinet 10 by, for example, screws (not shown). The holder 402 may be fixed with an adhesive.

  The leakage light becomes weaker as it travels outward from the optical path of the projection light. Therefore, in order to detect leaked light with high sensitivity, it is desirable that the illuminance sensor 401 be as close to the optical path as possible within a range that does not enter the optical path of the projection light.

  FIG. 4 is a diagram illustrating a configuration of a circuit system of the projector 1.

  The projector 1 includes a control circuit unit 50 in order to control the liquid crystal panels 211, 213, and 216, the light source lamp 201, and the like. The control circuit unit 50 includes a CPU 501, a memory 502, a key input circuit 503, an input switching circuit 504, an A / D converter 505, a signal processing circuit 506, a panel drive circuit 507, and a lamp drive circuit 508.

  The key input circuit 503 outputs an input signal corresponding to the key operation of the operation unit 104 to the CPU 501.

  The input switching circuit 504 switches input terminals to be connected from among a plurality of input terminals. A video signal, for example, an RGB signal is input from an input terminal connected by the input switching circuit 504. When the input RGB signal is analog, it is converted into a digital RGB signal by the A / D converter 505 and input to the signal processing circuit 506. If the RGB signal is a digital signal, it is input to the signal processing circuit 506 without going through the A / D converter 505.

  The signal processing circuit 506 includes a scan conversion circuit 509 and a correction circuit 510.

  The scan conversion circuit 509 performs scaling processing on the input video signal using the frame memory 511. As a result, the input video signal is converted into a video signal having a screen size that matches the screen size of the liquid crystal panels 211, 213, and 216.

  The correction circuit 510 performs various corrections such as white balance correction and gamma correction on the input video signal.

  When the video signal is a signal other than an RGB signal, the signal processing circuit 506 converts the signal into an RGB signal. The RGB signal output from the signal processing circuit 506 is input to the panel drive circuit 507.

  The panel drive circuit 507 drives the liquid crystal panels 211, 213, and 216 according to the input RGB signals. That is, the panel drive circuit 507 converts the RGB signals into drive voltage signals to be applied to the pixel electrodes of the corresponding liquid crystal panels 211, 213, and 216. Further, the panel drive circuit 507 generates a common voltage signal to be applied to the common electrodes (counter electrodes) of the liquid crystal panels 211, 213, and 216. The panel drive circuit 507 outputs these drive voltage signal and common voltage signal to the respective liquid crystal panels 211, 213, and 216. By changing the orientation of the liquid crystal according to the potential difference between the pixel electrode and the common electrode, the amount of light transmitted through the liquid crystal panels 211, 213, and 216 changes.

  The lamp driving circuit 508 drives the light source lamp 201 in accordance with a control signal from the CPU 501.

  The memory 502 includes RAM and ROM. The memory 502 stores a control program for giving a control function to the CPU 501.

  The CPU 501 controls the signal processing circuit 506 and the panel drive circuit 507 according to the control program stored in the memory 502. Further, the CPU 501 controls the light source lamp 201 by outputting a control signal to the lamp driving circuit 508 according to the control program.

  FIG. 5 is a flowchart showing the operation of the brightness adjustment process for adjusting the brightness of the projection light (image light) output from the projector 1.

  In the projector 1, the performance of each component such as the light source lamp 201 and the liquid crystal panels 211, 213, and 216 varies somewhat for each product. For this reason, even when the same image is projected, the brightness of the projection light, that is, the brightness of the projected image may vary.

  For example, as shown in FIG. 6, when multi-screen projection is performed in which a plurality of projectors 1 are used to project one image on a large screen, image quality may be deteriorated due to a difference in brightness between the projectors 1. . Therefore, it is necessary to adjust the brightness of the projection light for each projector 1 so as not to cause such a deterioration in image quality.

  For example, when a predetermined operation is performed on the operation unit 104 by the user, the brightness adjustment process is executed.

  Referring to FIG. 5, the CPU 501 causes the signal processing circuit 506 to generate a video signal of a test pattern image in which the entire image is white, and causes the generated test pattern image to be projected on the screen (S1).

  Next, the CPU 501 acquires the illuminance detected by the illuminance sensor 401 when the test pattern image is projected (S2). Then, the CPU 501 determines whether or not the acquired illuminance is a predetermined illuminance set in advance (S3). Adjust (S4).

  For example, if the acquired illuminance is lower than the specified illuminance, the CPU 501 decreases the common voltage signal output from the panel drive circuit 507, increases the potential difference between the pixel electrode and the common electrode, and each liquid crystal panel 211, The amount of transmitted light 213 and 216 is increased. This increases the brightness of the projection light. On the other hand, if the acquired illuminance is higher than the specified illuminance, the CPU 501 increases the common voltage signal output from the panel drive circuit 507 to reduce the potential difference between the pixel electrode and the common electrode, and thereby each liquid crystal panel 211, The amount of transmitted light 213 and 216 is reduced. Thereby, the brightness | luminance of projection light is reduced.

  Thus, the CPU 501 repeats the processing from step S2 to step S4. When the acquired illuminance becomes the specified illuminance (S3: YES), the CPU 501 stops projecting the test pattern image (S5) and ends the process.

  As described above, according to the present embodiment, when multi-screen projection is performed, the user can adjust the brightness in each projector 1, so that the brightness difference generated between the projectors 1 can be reduced. .

  In addition, since it is not necessary to arrange the illuminance sensor 401 on the screen in order to detect the brightness of the projection light, the adjustment work can be easily performed.

  Furthermore, according to the present embodiment, the illuminance sensor 401 is arranged at a position that does not enter the optical path of the projection light, and indirectly detects the light quantity of the projection light by detecting the light quantity of light leaking from the optical path. It is set as such. Thereby, it is possible to prevent a part of the projection light from being blocked by the illuminance sensor 401. Therefore, it is possible to prevent the image quality from being deteriorated due to the projection light being blocked.

  Further, the illuminance sensor 401 is arranged such that the light receiving surface 401a faces the direction of the optical path of the projection light. For this reason, the leakage light emitted toward the periphery from the optical path of the projection light tends to hit the light receiving surface 401a. Therefore, leakage light can be efficiently received by the light receiving surface 401a, and good detection can be performed by the illuminance sensor 401.

  As described above, the present embodiment has been described. However, the present invention is not limited to the above embodiment, and various modifications can be made to the embodiment of the present invention in addition to the above embodiment. It is.

  For example, in the above-described embodiment, the sensor unit 40 is disposed around the exit of the projection lens unit 30 and above the projection lens unit 30. However, the sensor unit 40 may be arranged anywhere such as the lower part, the right part, and the left part of the projection lens unit 30 as long as it is in the vicinity of the exit of the projection lens unit 30.

  In the above embodiment, the illuminance sensor 401 is disposed in the holder 402 at a position close to the opening 402a. However, as shown in FIG. 7A, the illuminance sensor 401 may be arranged in a position away from the opening 402 a in the holder 402. As a result, stray light is less likely to enter the illuminance sensor 401.

  Further, in the above embodiment, the illuminance sensor 401 is arranged so that the direction P of the light receiving surface 401 a is substantially perpendicular to the optical axis L of the projection lens unit 30. However, as shown in FIG. 7B, the illuminance sensor 401 may be tilted in the holder 402 so that the light receiving surface 401 a is not substantially perpendicular to the optical axis L and slightly faces the projection lens unit 30 side.

  Furthermore, in the above embodiment, the sensor unit 40 (holder 402) is fixed to the cabinet 10. However, the sensor unit 40 may be fixed to the projection lens unit 30 (housing 301).

  In the above embodiment, the luminance of the projection light is adjusted by changing the common voltage signal output from the panel drive circuit 507. However, the present invention is not limited to this. For example, the brightness of the projection light may be adjusted by changing the drive voltage signal output from the panel drive circuit 507. In this case, if the acquired illuminance is lower than the specified illuminance, the CPU 501 uniformly increases the drive voltage signal, increases the potential difference between the pixel electrode and the common electrode, and transmits through each of the liquid crystal panels 211, 213, and 216. Increase the amount of light. On the other hand, if the acquired illuminance is higher than the specified illuminance, the CPU 501 uniformly reduces the drive voltage signal and reduces the potential difference between the pixel electrode and the common electrode, thereby transmitting the transmitted light amount of each liquid crystal panel 211, 213, 216. Reduce.

Further, the brightness of the projection light may be adjusted by adjusting the output of the light source lamp 201. In this case, if the acquired illuminance is higher than the specified illuminance, the output of the light source lamp 201 is reduced. If the acquired illuminance is lower than the specified illuminance, the output of the light source lamp 201 is increased.
Further, the brightness of the projection light may be adjusted by adjusting at least one of the common voltage signal and the drive voltage signal and the output of the light source lamp 201.

  Further, in the present embodiment, the brightness of the projection light is adjusted based on the illuminance detected by the illuminance sensor 401. However, in place of the illuminance sensor 401 or in addition to the illuminance sensor 401, a chromaticity sensor is disposed in the vicinity of the exit of the projection lens unit 30, and the chromaticity is replaced with or in addition to the luminance of the projection light. May be adjusted. In this case, test signal images such as red, blue, and green are projected on the screen, and the magnitudes of the RGB signals from the CPU 501 so that the chromaticity detected by the chromaticity sensor becomes a predetermined chromaticity. Is adjusted by the panel driving circuit 507.

  Furthermore, although the light source lamp 201 is used in the above-described embodiment, not only the lamp light source but also a solid light source such as an LED light source or a laser light source may be used.

  In addition, the embodiment of the present invention can be variously modified as appropriate within the scope of the technical idea shown in the claims.

20 Optical engine 201 Light source lamp (light source)
211, 213, 216 Liquid crystal panel (light modulator)
30 Projection lens unit (projection unit)
40 Sensor unit 401 Illuminance sensor (light detection unit)
401a Light-receiving surface 402 Holder 402a Opening (opening)
50 control circuit unit 501 CPU (adjustment unit)
507 Panel drive circuit (adjustment unit)

Claims (5)

A light source;
A light modulator that modulates light from the light source to generate image light;
A projection unit that projects the image light generated by the light modulation unit onto a projection surface;
A light detection unit that is disposed at a peripheral position of an emission port of the projection unit and detects the image light emitted from the projection unit;
An adjustment unit that adjusts the state of the image light based on a detection result of the light detection unit;
A projection-type display device comprising: The projection display device according to claim 1,
The light detection unit is disposed at a position not to be in the optical path of the image light emitted from the projection unit, and indirectly detects the image light by detecting light leaking from the optical path.
A projection display device characterized by that. The projection display device according to claim 2,
The light detection unit is arranged such that a light receiving surface thereof faces a direction of an optical path of the image light.
A projection display device characterized by that. The projection display device according to any one of claims 1 to 3,
An opaque holder that is disposed around the exit and accommodates the light detection unit;
The holder has an opening that covers the periphery of the light detection unit and opens a light receiving surface of the light detection unit to the outside, and the opening is disposed so as to face the optical path of the image light.
A projection display device characterized by that. The projection display device according to any one of claims 1 to 4,
The light detection unit is an illuminance sensor,
The adjustment unit adjusts the luminance of the image light emitted from the projection unit based on the illuminance detected by the illuminance sensor.
A projection display device characterized by that.

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