JP2015184616A - projector - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a projector that can suppress unevenness in color and illuminance even when only some of a plurality of light sources are turned on.SOLUTION: A projector 100 of the present invention includes: a plurality of light sources 10a, 10b, 10c, and 10d; a light modulation device that modulates rays of light emitted from the plurality of light sources on the basis of input information; a projection optical system 70 that projects rays of light modulated by the light modulation device; a light guide optical system 20 that has a plurality of rays of light emitted from the plurality of light sources made incident on different areas, respectively, and guides each of the plurality of rays of incident light to the light modulation device; a lighting detection unit 41 that detects the lighting state of the plurality of light sources; and a control unit 45 that performs gamma correction of the input information by using correction information based on viewing angle characteristics of the light modulation device according to the lighting state of the plurality of light sources detected by the lighting detection unit.

Description

  The present invention relates to a projector.

For example, Patent Document 1 below discloses a projector including two light source lamps for the purpose of displaying a bright image and extending the life of the light source. In this patent document, the light source lamps are turned on and used one by one, so that the period until the replacement of the light source lamps is doubled, and if necessary, two light source lamps are turned on and used. It is described that a luminance image can be easily realized.

JP 2001-359025 A

In a projector provided with a plurality of light sources, there may be a case where only a part of the remaining light sources is turned on due to a lifetime or failure of some of the light sources. Alternatively, it may be possible to intentionally turn on only some of the light sources in order to extend the life of the light sources as described above. In such a case, there is a problem that not only the overall brightness of the image is lowered, but also color unevenness and brightness unevenness occur.

One aspect of the present invention is made to solve the above-described problem, and can suppress color unevenness and brightness unevenness even when only a part of a plurality of light sources is turned on. One of the purposes is to provide a projector.

To achieve the above object, a projector according to an aspect of the present invention includes a plurality of light sources, a light modulation device that modulates light emitted from the plurality of light sources based on input information, and the light modulation device. A projection optical system that projects the light modulated by the light guide optical, and a plurality of light emitted from the plurality of light sources are incident on different areas, and each of the incident light is guided to the light modulation device Correction information based on the viewing angle characteristics of the light modulation device according to the lighting state of the light source, the lighting detection unit for detecting the lighting state of the plurality of light sources, and the lighting state of the plurality of light sources detected by the lighting detection unit And a control unit for performing gamma correction of the input information.

The inventors of the present invention have conceived the reason why color unevenness and brightness unevenness occur in the state where only some of the light sources are turned on as follows, and have arrived at the configuration of the present invention.
That is, in a projector provided with a plurality of light sources, a plurality of lights emitted from a plurality of light sources arranged at different positions are guided to the light modulation device by the light guide optical system and superimposed. Therefore, if the position where the light source is arranged is different, the incident angle of the light incident on the light modulation device is also different. In general, the light modulator generally has asymmetric viewing angle characteristics. Therefore, the gamma characteristics of the light modulation device differ depending on the lighting state of the plurality of light sources, and there arises a problem that color unevenness and illuminance unevenness occur.

On the other hand, in the projector according to one aspect of the present invention, the control unit uses correction information based on the viewing angle characteristics of the light modulation device according to the lighting state of the plurality of light sources detected by the lighting detection unit. Perform gamma correction on input information. Thereby, even if only a part of the plurality of light sources is turned on, a projector in which color unevenness and illuminance unevenness are suppressed can be realized.

In the projector according to one aspect of the present invention, the plurality of light sources emits light incident on the light modulation device from an azimuth angle direction corresponding to a clear vision direction of the viewing angle characteristics;
A second light source that emits light incident on the light modulation device from an azimuth angle direction corresponding to a reverse clear vision direction of the viewing angle characteristics, and the correction information is when the first light source is turned on The first correction information and second correction information when the second light source is turned on may be included.
According to this configuration, the correction information regarding the light source that has a large influence on the viewing angle characteristics, that is, the correction information when the first light source corresponding to the clear viewing direction of the viewing angle characteristics is turned on, and the viewing angle characteristics. By using the correction information including the correction information when the second light source corresponding to the reverse clear vision direction is turned on, it is possible to effectively perform the gamma correction.

In the projector according to one aspect of the present invention, the control unit may be one of the first correction information and the second correction information when one of the first light source and the second light source is in a lighting state. One may be used to perform gamma correction of the input information.
According to this configuration, when any one of the first light source and the second light source is in a lighting state,
Since any one of the first correction information and the second correction information is used to perform gamma correction of the input information, appropriate gamma correction can be performed.

In the projector according to one aspect of the present invention, the first correction information and the second correction information include correction information when only the first light source is turned on, and when only the second light source is turned on. And correction information based on at least one of the correction information.
According to this configuration, the amount of correction information acquired can be reduced, and the load on the control unit can be reduced.

It is a schematic block diagram which shows the projector of one Embodiment of this invention. (A), (b) It is a figure for demonstrating the structure and effect | action of a light guide optical system. It is a figure which shows the viewing angle characteristic of a liquid crystal panel. It is a figure which shows the VT characteristic when the 1st light source is lighting. It is a figure which shows the VT characteristic when the 2nd light source is lighting. It is a figure which shows the VT characteristic when the 3rd light source is lighted. It is a figure which shows the VT characteristic when the 4th light source is lighted. It is a figure which shows the VT characteristic when the 3rd light source and the 4th light source are lighted. It is a figure which shows the VT characteristic when the 1st light source and the 2nd light source are lighting. It is a flowchart of the gamma correction which a control part performs.

Hereinafter, an embodiment of the present invention will be described with reference to FIGS.
In the present embodiment, an example of a projector that includes four light sources and uses a liquid crystal light valve as a light modulation device, that is, a so-called four-lamp type liquid crystal projector is given.
FIG. 1 is a schematic configuration diagram illustrating a projector according to the present embodiment.
In the following drawings, in order to make each component easy to see, the scale of the size may be varied depending on the component.

As shown in FIG. 1, the projector 100 according to the present embodiment includes R (red), G (green), and B (
This is a three-plate type liquid crystal projector provided with a transmissive liquid crystal light valve for each different color (blue). The projector 100 includes four light sources 10a, 10b, 10c, and 10d, a light guide optical system 20, an integrator optical system 30, a lighting detection unit 41, a storage unit 42, and a control unit 45.
A color separation optical system 50, liquid crystal light valves 61, 62 and 63, a cross dichroic prism 64, and a projection optical system 70. In the present embodiment, the light sources 10a to 10a.
d, the light guide optical system 20, and the integrator optical system 30 constitute the illumination device 10.
The liquid crystal light valves 61, 62, and 63 of the present embodiment correspond to the light modulation device in the claims.

Each of the light sources 10a, 10b, 10c, and 10d includes a lamp such as an ultra-high pressure mercury lamp, a metal halide lamp, or a xenon lamp, and a reflector that reflects the light of the lamp. A light source control unit 110 that drives and controls these light sources is connected to the light sources 10a, 10b, 10c, and 10d.

The light guide optical system 20 includes four mirrors 21a, 21b, 21c, and 21d. The light guide optical system 20 causes the light emitted from the light sources 10a, 10b, 10c, and 10d to enter different positions of the first integrator lens 31 described later, and guides these lights to the liquid crystal light valves 61, 62, and 63. .

The integrator optical system 30 is an optical system for uniformly illuminating the liquid crystal light valves 61, 62, 63 with each light from the light sources 10a, 10b, 10c, 10d. The integrator optical system 30 includes a first integrator lens 31, a second integrator lens 32, a polarization conversion element 33, and a superimposing lens 34 that are arranged in this order from the light guide optical system 20 side.

FIG. 2A is a view of the light sources 10a, 10b, 10c, and 10d and the light guide optical system 20 as viewed from the first integrator lens 31 side (in the −Y direction). FIG. 2B is an explanatory diagram of the operation of the light guide optical system 20, and is a view of the first integrator lens 31 viewed from the second integrator lens 32 side (in the −Y direction).

As shown in FIGS. 1 and 2A, the light source 10a and the light source 10b are disposed so as to face each other in the light emission direction (X-axis direction in the drawing). A mirror 21a is disposed in front of the light source 10a, and a mirror 21b is disposed in front of the light source 10b. Mirror 21a
And the mirror 21b respectively transmit the light from the light sources 10a and 10b to the first integrator lens 31.
It is arranged at an angle of 45 ° with respect to the light emission direction (X-axis direction) so as to be bent in the direction of.

The light source 10c and the light source 10d are disposed to face each other in the light emission direction.
A mirror 21c is disposed in front of the light source 10c, and a mirror 21d is disposed in front of the light source 10d. The mirror 21c and the mirror 21d are arranged at an angle of 45 ° with respect to the light emission direction (X-axis direction) so as to bend the light of the light sources 10c and 10d in the direction of the first integrator lens 31, respectively. .

In the present embodiment, the light sources 10a to 10d are arranged vertically (in the Z-axis direction) as shown in FIG.
Are arranged in two stages. On the upper side (+ Z side), the light sources 10c and 10d and the mirror 2
1c and 21d are arranged. Light sources 10a and 10b and mirrors 21a and 21b are arranged on the lower side (−Z side). In the case of the present embodiment, as shown in FIG. 1, the lower light sources 10a and 10b and the mirrors 21a and 21b are closer to the first integrator lens 31 than the upper light sources 10c and 10d and the mirrors 21c and 21d. Is provided.

In the light guide optical system 20 having the above configuration, as shown in FIG.
The light beams 11a, 11b, 11c and 11d emitted from the mirrors 21a and 21d respectively correspond to the corresponding mirrors 21a.
, 21b, 21c, and 21d and bent toward the side where the first integrator lens 31 is disposed. Light beams 11a to 11d bent by mirrors 21a to 21d
Are incident on different partial areas of the first integrator lens 31, respectively. Specifically, the light beams 11a to 11d are respectively incident on four partial regions 31a to 31d obtained by dividing the first integrator lens 31 into two equal parts in the vertical and horizontal directions (Z-axis direction and X-axis direction). In the present embodiment, these four light beams 11 a to 11 d are converted into the first integrator lens 3.
Irradiate the entire area of 1.

In the case of the present embodiment, the first integrator lens 31 shown in FIG. 2B is configured by fly-eye lenses in which small lenses (lens elements) are arranged in 6 rows and 6 columns in the row direction and the column direction. Yes. Each of the partial areas 31a to 31d includes a small lens group having 3 rows and 3 columns. In the present embodiment, the first integrator lens 31 is illustrated and described as a small lens group of 6 rows and 6 columns, but in reality, more small lenses than 6 rows and 6 columns are arranged. The size of the first integrator lens 31, that is, the number of small lenses arranged, is determined by the light sources 10a to 10a.
It is determined according to the size of the light beams 11a to 11d emitted from 10d.

The light emitted from each lens element of the first integrator lens 31 passes through the second integrator lens 32 and the superimposing lens 34 and passes through the liquid crystal light valves 61 to 6.
3 is superimposed.
Note that only the second integrator lens 32 may function as a superimposing lens. In this case, the superimposing lens 34 may not be provided.

The polarization conversion element 33 is provided between the second integrator lens 32 and the superimposing lens 34. The polarization conversion element 33 is composed of, for example, a polarization beam splitter array (PBS array). The polarization conversion element 33 aligns the polarization direction of the light emitted from the second integrator lens 32 and emits it as a single linearly polarized light. The polarization conversion element 33 has a structure in which substantially rod-like prism elements each having a polarization separation film, a reflection film, and a retardation plate are periodically arranged in the width direction (X-axis direction).

The color separation optical system 50 includes a first dichroic mirror 51 and a second dichroic mirror 5.
2, a reflection mirror 53, and a relay optical system 54. The relay optical system 54 includes a relay lens 55, a reflection mirror 56, a relay lens 57, and a reflection mirror 58. The color separation optical system 50 converts the illumination light emitted from the integrator optical system 30 into red (
The light beams are separated into three color lights of R), green (G), and blue (B), and each color light is guided to the liquid crystal light valves 61, 62, 63 on the downstream side of the optical path.

The first dichroic mirror 51 has a characteristic of transmitting R light and reflecting G light and B light among the three colors R, G, and B. The second dichroic mirror 52 has a characteristic of reflecting the G light and transmitting the B light out of the G light and B light reflected by the first dichroic mirror 51.

The R light transmitted through the first dichroic mirror 51 is incident on the liquid crystal light valve 61 through the reflection mirror 53. The G light reflected by the first dichroic mirror 51 and further reflected by the second dichroic mirror 52 enters the liquid crystal light valve 62. The B light that has passed through the second dichroic mirror 52 enters the liquid crystal light valve 63 through the relay lens 55, the reflection mirror 56, the relay lens 57, and the reflection mirror 58.

The liquid crystal light valves 61, 62, and 63 modulate the spatial intensity distribution of incident illumination light based on an image signal that is input information. The polarization states of the three colors of light incident on the liquid crystal panels of the liquid crystal light valves 61, 62, and 63 are adjusted in units of pixels. Liquid crystal light valve 61
, 62, and 63, modulated light of each color corresponding to each, that is, image light is formed.
Each of the liquid crystal light valves 61, 62, and 63 includes a liquid crystal panel and a pair of polarizing plates that sandwich the liquid crystal panel. The mode of the liquid crystal layer in the liquid crystal panel is vertical alignment (Vertical
Alignment, VA) mode, Twisted Nematic (TN) mode, transverse electric field mode, and the like may be used, and the VA mode is used in the present embodiment, although not particularly limited. A field lens may be provided on the light incident side of the liquid crystal panel.

The cross dichroic prism 64 combines the image lights of the respective colors emitted from the liquid crystal light valves 61, 62, 63 and emits them to the projection optical system 70. The cross dichroic prism 64 is configured by bonding four right-angle prisms. A first dielectric multilayer film and a second dielectric multilayer film intersecting in an X shape are formed at the interface where the right-angle prisms are bonded together. The cross dichroic prism 64 outputs the R light from the liquid crystal light valve 61 to the first.
Reflected by the dielectric multilayer film and emitted toward the projection optical system 70, B from the liquid crystal light valve 63
Light is reflected by the second dielectric multilayer film and emitted toward the projection optical system 70. The cross dichroic prism 64 allows the G light from the liquid crystal light valve 62 to pass therethrough and travel straight. In this way, the R light, the G light, and the B light are combined by the cross dichroic prism 64 to form combined light that is image light based on a color image.

The projection optical system 70 enlarges the image light by the combined light formed through the cross dichroic prism 64 at a desired magnification and projects a color image on a screen (not shown).

The lighting detection unit 41 includes four light sources 10a, 10b, 10c, detected by the light source control unit 110.
From the detection result of the lamp voltage (interelectrode voltage) of 10d, the four light sources 10a, 10b, 10c
, 10d, that is, which light source is currently turned on and which light source is turned off. Regarding the detection of lighting / extinguishing, the lighting detection unit 41 may determine whether or not the light source is driven due to the end of life or failure, or drive information related to the light source such as light quantity, luminance, voltage, and current. You may judge by whether it exceeds the predetermined threshold value.

The storage unit 42 stores correction information related to the VT characteristic based on the viewing angle characteristics of the liquid crystal light valves 61, 62, and 63, which will be described later. The control unit 45 uses the correction information based on the viewing angle characteristics of the liquid crystal light valves 61, 62, 63 according to the lighting states of the four light sources 10a, 10b, 10c, 10d detected by the lighting detection unit 41. Perform gamma correction on the image signal (input information).

FIG. 3 is a diagram showing the viewing angle characteristics of the contrast of the liquid crystal panel of the present embodiment.
When, for example, a VA mode liquid crystal panel is used as the liquid crystal panel of this embodiment, a pretilt is given to the liquid crystal molecules in order to regulate the tilt direction of the liquid crystal molecules when an electric field is applied. Due to the pretilt of liquid crystal molecules, the VA mode liquid crystal panel has asymmetric viewing angle characteristics as shown in FIG. The curve in FIG. 3 is an iso-contrast curve. The contrast curve closer to the center has higher contrast, and the contrast curve closer to the periphery has lower contrast. In this example, the region where the contrast is maximum is shifted from the center, that is, the polar angle (incident angle) of 0 °, in the direction of the azimuth angle of 45 °. In other words, the region with high contrast is wide in the direction of azimuth angle 45 °, and conversely, the region with high contrast is narrow in the direction of azimuth angle 225 °. Therefore, the clear vision direction is 45 ° and the reverse clear vision direction is 225 °.

Here, as shown in FIG. 2B, the light beams 11 a to 11 d incident on different partial regions of the first integrator lens 31 are converted into the second integrator lens 32 and the superimposing lens 3.
4 is condensed and superimposed on the same region of the liquid crystal light valves 61, 62, 63. Therefore, the liquid crystal light valves 61, 62, 6 are provided by the light sources 10a, 10b, 10c, 10d.
3 is different in the incident angle (azimuth angle) of light. In the case of the projector 100, since the observer does not directly visually recognize the liquid crystal panel, the viewing angle characteristic of the liquid crystal panel is not the contrast characteristic of the liquid crystal panel according to the viewing direction but the liquid crystal panel according to the incident direction of light. It can be considered that the contrast characteristic.

As shown in FIG. 3, among the four light sources 10a, 10b, 10c, and 10d, a light source that mainly emits light incident on the liquid crystal panel from the azimuth angle direction corresponding to the clear viewing direction (azimuth angle 45 °). A light source that mainly emits light incident on the liquid crystal panel from an azimuth angle direction corresponding to the reverse clear vision direction (azimuth angle 225 °) is referred to as a second light source. A light source that mainly emits light incident on the liquid crystal panel from an azimuth direction corresponding to an azimuth angle of 135 ° is referred to as a third light source, and an azimuth angle 315
A light source that mainly emits light incident on the liquid crystal panel from the azimuth direction corresponding to ° is referred to as a fourth light source. The correspondence relationship between the first to fourth light sources and the light sources 10a to 10d is as follows.
Depending on the nature, number, arrangement, etc. of the optical components that guide each light from 10d to the respective liquid crystal light valves 61, 62, 63.

4 to 9 are diagrams showing the results of simulation performed by the present inventors, and the applied voltage of the liquid crystal panel based on the viewing angle characteristics of the liquid crystal panel according to the lighting state of each light source.
It is a figure which shows a light quantity characteristic (VT characteristic). Here, the light quantity indicates the leakage light quantity when the liquid crystal panel is driven in black display. 4 to 9, the light amount value is appropriately normalized so that the change in the leakage light amount with respect to the voltage in each lighting state can be easily compared, and the actual light amount value increases or decreases according to the lighting state of the light source. .

FIG. 4 shows VT characteristics when only one light of the first light source is lit. FIG. 5 shows the VT characteristic when only one of the second light sources is on. FIG. 6 shows the VT characteristic when only one of the third light sources is lit. FIG. 7 shows the VT characteristics when only one of the fourth light sources is on. FIG. 8 shows VT characteristics when two lights of the third light source and the fourth light source are turned on. FIG. 9 shows VT characteristics when two lights of the first light source and the second light source are turned on.
4 to 9, VT characteristics when only some of the light sources are turned on, and VT characteristics when four lights are turned on as all of the four light sources as a comparative example. Are shown together. In addition, since the VT characteristic is different for each liquid crystal panel corresponding to each color of R, G, and B, the VT characteristic is shown for each color of R, G, and B.

As can be seen from FIG. 4, the first light is emitted from the azimuth direction corresponding to the clear vision direction.
When only the light source is turned on, the VT curve shifts in the direction in which the amount of light decreases (below the graph) with respect to the case of four lamps in which all four light sources are turned on. On the other hand, as can be seen from FIG. 5, when only the second light source that emits light incident from the azimuth angle direction corresponding to the reverse clear vision direction is lit, all four light sources are lit. The VT curve shifts in the direction in which the amount of light increases (upward in the graph).

6 to 9, only the third light source is lit, only the fourth light source is lit, two lights of the first light source and the second light source are lit. In the case where either one of the light source and the fourth light source is lit, the VT curve is not shifted as compared to the case where the four lights are all lit. For example, as shown in FIG. 6 and FIG.
When only one light source is lit, an average value of the VT characteristic of the first light source corresponding to the clear vision direction and the VT characteristic of the second light source corresponding to the reverse clear vision direction is taken. Therefore, it is considered that the VT curve does not shift. Further, as shown in FIG. 9, two of the first light source and the second light source.
When the lamp is lit, the increase in the amount of light when only the first light source is lit up and the decrease in the amount of light when only the second light source is lit up, and the VT curve shifts It is thought not to.

From the above, in the present embodiment, two correction information is acquired: a VT curve when only the first light source is lit, and a VT curve when only the second light source is lit. Then, the control unit 45 can perform gamma correction according to all lighting state patterns from these correction information. The VT curve as the correction information is stored in the storage unit 42 in the form of a lookup table, for example. The control unit 45 reads correction information related to the VT curve from the storage unit 42, and calculates the VT characteristic in an arbitrary light source lighting state as necessary. Thereby, the control unit 45 can perform the optimum gamma correction according to the lighting state of the light source.
In the present embodiment, correction information when the first light source is turned on is first correction information, and correction information when the second light source is turned on is second correction information. Furthermore, the first correction information and the second correction information are each based on at least one of correction information when only the first light source is lit and correction information when only the second light source is lit. .

FIG. 10 is a flowchart showing a control procedure in the control unit 45.
First, the control unit 45 includes the four light sources 10a, 10b, and 10c detected by the lighting detection unit 41.
, 10d, that is, which light source is currently turned on and which light source is turned off (step S1).
Next, the control unit 45 receives the detection result of the lighting detection unit 41 and determines whether there is a light source that is currently turned off (step S2).

When there is a light source that is turned off (step S2: YES), the control unit 45 determines whether one of the first light source and the second light source is turned on (step S3).

When one of the first light source and the second light source is lit (step S3: YES)
The control unit 45 uses one of the corresponding correction information among the first correction information when the first light source is turned on and the second correction information when only the second light source is turned on. Then, gamma correction of the image signal is performed (step S4).

For example, when only one of the four light sources is turned on, that is, when one of the first light source and the second light source is turned on, the control unit 45 correct | amends input information using the correction information in case only the 1st light source is lighting as 1st correction information. In the lighting state in which two of the four light sources, the second light source and the third light source, are turned on, that is, one of the first light source and the second light source is turned on. In this case, the control unit 45 calculates the correction information as the second correction information based on the correction information when only the first light source is turned on and the correction information when only the second light source is turned on, The gamma correction of the image signal (input information) is performed using the calculated second correction information.

On the other hand, when there is no light source that is turned off in step S2 (step S2: NO), the control unit 45 uses the correction information at the time of normal lighting, that is, four lamps in which all four light sources are turned on. Then, gamma correction of the image signal (input information) is performed (step S5).
At this time, correction information (look-up table) at the time of lighting of four lamps calculated in advance and stored in the storage unit 42 may be acquired and corrected using this. Alternatively, the correction information when only the first light source stored in advance in the storage unit 42 is turned on and the correction information when only the second light source is turned on are acquired and calculated based on these. The gamma correction of the image signal (input information) may be performed using the correction information.

In step S3, either the first light source or the second light source is not lit, that is, both the first light source and the second light source are lit, or both are not lit. If present (step S3: NO), the control unit 45 performs gamma correction of the image signal using the correction information at the time of normal lighting (step S5).

For example, among the four light sources, in the lighting state in which three lights of the first light source, the second light source, and the fourth light source are lit, that is, both the first light source and the second light source are lit. If
The control unit 45 corrects the input information using the correction information when all four lights are lit. Alternatively, the control unit 45 uses the correction information calculated based on the correction information when only the first light source is lit and the correction information when only the second light source is lit, as an image signal (input information). ) Gamma correction.
Thereafter, the above procedure is repeated.
The detection of the lighting state of the light source in step S1 may be performed at regular intervals, for example.

In the projector 100 of the present embodiment, the control unit 45 determines the viewing angles of the liquid crystal light valves 61, 62, and 63 according to the lighting states of the four light sources 10a, 10b, 10c, and 10d detected by the lighting detection unit 41. Gamma correction of an image signal is performed using correction information based on characteristics. Accordingly, it is possible to reduce color unevenness and illuminance unevenness that have conventionally occurred when only some of the four light sources 10a, 10b, 10c, and 10d are turned on.

In particular, in this embodiment, if two VT curves when only the first light source is lit and VT curves when only the second light source is lit are acquired as correction information, From the correction information, gamma correction corresponding to all lighting state patterns can be performed. Therefore,
In addition to reducing the time and effort required to acquire data before the projector 100 is shipped,
The amount of data stored in the projector 100 and the calculation amount of the VT characteristic can be reduced.

The technical scope of the present invention is not limited to the above embodiment, and various modifications can be made without departing from the spirit of the present invention.
For example, in the above-described embodiment, an example of a projector including four light sources has been described. However, the number of light sources is not limited to four and can be changed as appropriate. Moreover, although the example of the viewing angle characteristic of VA mode was given as a viewing angle characteristic of a liquid crystal panel, the liquid crystal panel of other modes, such as TN mode and a horizontal electric field mode, may be used, for example. Since the viewing angle characteristic changes depending on the mode, information on the VT characteristic when the light source corresponding to the clear vision direction, the reverse clear vision direction, or the like is turned on according to the viewing angle characteristic may be acquired.

In the above-described embodiment, an example in which the present invention is applied to a transmissive projector has been described. However, the present invention can also be applied to a reflective projector. Here, the “transmission type” means that a liquid crystal light valve including a liquid crystal panel or the like is a type that transmits light. “Reflective type” means that the liquid crystal light valve reflects light. The light modulation device is not limited to a liquid crystal panel or the like, and may be a light modulation device using a micromirror, for example.

Further, in the above-described embodiment, only the example of the projector 100 using the three liquid crystal panels (liquid crystal light valves 61 to 63) has been described. However, the present invention is a projector using only one liquid crystal panel, four or more projectors. The present invention can also be applied to projectors using other liquid crystal panels.
In addition, the number, arrangement, materials, and the like of each component of the projector can be appropriately changed without being limited to the above embodiment.

10a, 10b, 10c, 10d ... light source, 20 ... light guide optical system, 41 ... lighting detection unit, 45
Control unit 61, 62, 63 Liquid crystal light valve (light modulation device) 70 Projection optical system

Claims (4)

Multiple light sources;
A light modulation device that modulates light emitted from the plurality of light sources based on input information;
A projection optical system that projects the light modulated by the light modulation device;
A plurality of light beams emitted from the plurality of light sources are incident on different regions, and each of the incident light beams is guided to the light modulation device;
A lighting detection unit for detecting lighting states of the plurality of light sources;
A control unit that performs gamma correction of the input information using correction information based on viewing angle characteristics of the light modulation device according to the lighting state of the plurality of light sources detected by the lighting detection unit;
A projector comprising: The plurality of light sources include a first light source that emits light incident on the light modulation device from an azimuth angle direction corresponding to a clear viewing direction of the viewing angle characteristic, and an orientation corresponding to a reverse clear viewing direction of the viewing angle characteristic. A second light source that emits light incident on the light modulation device from an angular direction,
The correction information includes first correction information when the first light source is turned on and second correction information when the second light source is turned on. The projector described. The controller is configured to perform gamma correction of the input information using either the first correction information or the second correction information when either the first light source or the second light source is in a lighting state. The projector according to claim 2, wherein: The first correction information and the second correction information are at least one of correction information when only the first light source is lit and correction information when only the second light source is lit. 4. The projector according to claim 2, wherein the correction information is based on the correction information.

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