JP2023009775A - projector - Google Patents

Abstract

A projector capable of suppressing an increase in size of a swinging optical plate of an optical shift device is provided.
A projector 1 includes a first light modulation element (liquid crystal panel 10G) that modulates a first color light (G light) and a second light modulation element (liquid crystal panel 10R) that modulates a second color light (R light). and a third light modulation element (liquid crystal panel 10B) that modulates the third color light (B light). It also includes an optical synthesizing element 80 that synthesizes the modulated light to form image light, and a projection optical system 85 that projects the image light. In addition, a first optical shift device 100 (shift device 100G) and a second optical shift device 100 (shift device 100G) are arranged between each light modulation element and the optical synthesizing element 80 to shift the optical path of the light modulated by each light modulation element. A shift device 100 (shift device 100R) and a third optical shift device 100 (shift device 100B) are provided.
[Selection drawing] Fig. 1

Description

The present invention relates to projectors.

Conventionally, in projectors using liquid crystal panels that modulate red (R) light, green (G) light, and blue (B) light respectively, the modulated light from each liquid crystal panel is synthesized by an optical synthesizing element such as a dichroic prism to create an image. After forming the light, it is projected through a projection optical system. In the projector of Patent Document 1, an optical shift device is arranged between the optical synthesizing element and the projection optical system, and by swinging the optical shift device, the optical path of the image light is shifted to increase the pseudo resolution. is disclosed.

JP 2016-90751 A

However, in the projector disclosed in Patent Document 1 equipped with an optical shift device, the optical path of the image light obtained by synthesizing the modulated light from the R, G, and B liquid crystal panels is shifted. The distance to the optical shift device increases and the beam spreads. Further, when the distance between the member holding the liquid crystal panel and the member holding the optical shift device increases, the number of intervening parts increases, resulting in a large accumulated tolerance during assembly. Therefore, in order to pick up the spread image light and compensate for the cumulative tolerance, it became necessary to increase the size of the oscillating optical plate of the optical shift device, which affected the miniaturization of the optical shift device.

The projector modulates with a first light modulation element that modulates a first color light, a second light modulation element that modulates a second color light, a third light modulation element that modulates a third color light, and the first light modulation element. an optical synthesizing element for synthesizing the light modulated by the second light modulating element, the light modulated by the third light modulating element, and the light modulated by the third light modulating element to form image light; and the image from the optical synthesizing element a projection optical system for projecting light; a first optical shift device disposed between the first light modulation element and the optical synthesizing element for shifting an optical path of the light modulated by the first light modulation element; a second optical shift device disposed between the second optical modulation element and the optical synthesizing element for shifting an optical path of the light modulated by the second optical modulation element; the third optical modulation element and the optical and a third optical shift device disposed between the combining element and the third optical shift device for shifting the optical path of the light modulated by the third light modulation element.

The projector includes a first light modulation element that modulates green light, a second light modulation element that modulates red light, a third light modulation element that modulates blue light, and light modulated by the first light modulation element. an optical synthesizing element for synthesizing the light modulated by the second light modulating element and the light modulated by the third light modulating element to form image light; and projecting the image light from the optical synthesizing element. and an optical shift device disposed between the first light modulation element and the optical synthesizing element for shifting the optical path of the light modulated by the first light modulation element.

2 is a diagram showing a schematic configuration of an optical system of the projector according to the first embodiment; FIG. FIG. 4 is a diagram simply showing the components around the shift device of the optical system; FIG. 2 is a perspective view showing the configuration of an optical shift device; FIG. 4 is an explanatory diagram showing shift of the image projection position due to the optical path shift of the optical shift device; FIG. 4 is a diagram showing projection pixels displayed on a projection surface by one pixel; FIG. 2 is a block diagram showing a schematic configuration of a control system of the projector; FIG. 5 is an explanatory diagram showing the relationship between the optical path shift operation of the optical shift device and the write operation to the pixel by the drive circuit; FIG. 5 is a diagram showing a schematic configuration of an optical system of a projector according to a second embodiment; FIG. 3 is a simplified view of a component corresponding to FIG. 2 in a conventional optical system;

1. First Embodiment A projector 1 according to this embodiment will be described.
FIG. 1 is a diagram showing a schematic configuration of an optical system 2 of a projector 1 according to this embodiment.
In FIG. 1, a coordinate system having an X-axis, a Y-axis, and a Z-axis is set as three mutually orthogonal axes. The emission direction of combined image light for projection onto the projection surface SC is the +Y direction. A horizontal direction including the Y-axis and perpendicular to the Y-axis is defined as a +X direction. The +Z direction is the upward direction. The opposite directions of the respective axes are the -X direction, the -Y direction, and the -Z direction.

As shown in FIG. 1, the optical system 2 of the projector 1 of this embodiment includes an illumination optical system 90, a color separation optical system 70, three liquid crystal panels 10, three optical shift devices 100, three incident side polarizing plates 65, It has three exit-side polarizing plates 60 , an optical synthesizing element 80 , and a projection optical system 85 .

The illumination optical system 90 homogenizes the illuminance of the light emitted from the light source in a plane orthogonal to the illumination optical axis, and superimposes it on the surface of the liquid crystal panel 10 as a light modulation element. The illumination optical system 90 uses a discharge-type light source lamp 91 as a light source in this embodiment, and irradiates light. The illumination optical system 90 is not limited to the configuration using the discharge-type light source lamp 91 as the light source, and a laser light source, an LED (Light Emitting Diode) light source, or the like can be used. In this embodiment, the illumination optical system 90 shows only a light source, and other configurations are omitted.

The color separation optical system 70 separates the illumination light emitted from the illumination optical system 90 into three color lights of red light, green light, and blue light, and guides the light to the corresponding three liquid crystal panels 10 . Hereinafter, red will be referred to as "R", green as "G", and blue as "B". The color separation optical system 70 has three reflecting mirrors 71, 72, 73 and two dichroic mirrors 75, 76. As shown in FIG. Of the illumination light emitted from the illumination optical system 90, the dichroic mirror 75 transmits light in the R light wavelength range and reflects light in the G light and B light wavelength ranges. The dichroic mirror 76 transmits the light in the wavelength range of the B light among the light in the wavelength range of the G light and the B light reflected by the dichroic mirror 75 and reflects the light in the wavelength range of the G light.

Each color light (R light, G light, B light) separated by the color separation optical system 70 is guided to the liquid crystal panel 10 corresponding to each color light. The liquid crystal panel 10 operates as a light modulation element that modulates each color light. The three liquid crystal panels 10 are transmissive liquid crystal panels, and are composed of a liquid crystal panel 10R for R light, a liquid crystal panel 10G for G light, and a liquid crystal panel 10B for B light.

In this embodiment, the liquid crystal panel 10G for G light corresponds to the first light modulation element and the first liquid crystal panel. Also, the liquid crystal panel 10R for R light corresponds to the second light modulation element and the second liquid crystal panel. Also, the liquid crystal panel 10B for B light corresponds to the third light modulation element and the third liquid crystal panel. Also, the G light corresponds to the first color light, the R light corresponds to the second color light, and the B light corresponds to the third color light.

An incident side polarizing plate 65 is provided on the incident side of the liquid crystal panel 10 . Further, the exit side of the liquid crystal panel 10 is provided with an optical shift device 100, an exit side polarizing plate 60, and an optical synthesizing element 80 in this order. In other words, the exit-side polarizing plate 60 is arranged between the optical shift device 100 and the optical synthesizing element 80 on the exit side of the liquid crystal panel 10 . The incident-side polarizing plate 65 and the exit-side polarizing plate 60 improve contrast and brightness by adjusting the direction along the polarization axis of light to an optimum angle for each liquid crystal panel 10 .

In this embodiment, an optical shift device 100 is arranged between the liquid crystal panel 10 and the exit-side polarizing plate 60 . In other words, the optical shift device 100 is arranged between the liquid crystal panel 10 and the optical combining element 80 . The optical shift device 100 shifts the optical path of each color light modulated by the liquid crystal panel 10 .

Hereinafter, the details of the arrangement of the liquid crystal panel 10, the entrance-side polarizer 65, the optical shift device 100, and the exit-side polarizer 60 will be described for each color of light.
The incident side of the liquid crystal panel 10R for R light is provided with an incident side polarizing plate 65R for R light, and the exit side is provided with an exit side polarizing plate 60R for R light. A shift device 100R for R light is provided between the liquid crystal panel 10R for R light and the exit-side polarizing plate 60R for R light. Further, the incident side of the liquid crystal panel 10G for G light is provided with an incident side polarizing plate 65G for G light, and the emitting side is provided with an exit side polarizing plate 60G for G light. A G-light shift device 100G is provided between the G-light liquid crystal panel 10G and the G-light emission side polarizing plate 60G. Further, the incident side of the liquid crystal panel 10B for B light is provided with an incident side polarizing plate 65B for B light, and the exit side is provided with an exit side polarizing plate 60B for B light. A shift device 100B for B light is provided between the liquid crystal panel 10B for B light and the exit-side polarizing plate 60B for B light.

In this embodiment, the shift device 100G for G light corresponds to the first optical shift device. Also, the emission-side polarizing plate 60G for G light corresponds to the first polarizing plate. A shift device 100R for R light corresponds to the second optical shift device. Also, the exit-side polarizing plate 60R for R light corresponds to the second polarizing plate. The shift device 100B for B light corresponds to the third optical shift device. Also, the exit-side polarizing plate 60B for B light corresponds to the third polarizing plate.

As described above, the liquid crystal panels 10R, 10G, and 10B are referred to as the "liquid crystal panel 10" when not distinguished from each other. Similarly, when the shift devices 100R, 100G, and 100B are not distinguished from each other, they are referred to as "optical shift device 100." Moreover, when the exit-side polarizing plates 60R, 60G, and 60B are not distinguished, they are referred to as "exit-side polarizing plates 60". When the incident side polarizing plates 65R, 65G, and 65B are not distinguished, they are referred to as "incident side polarizing plates 65".

The optical synthesizing element 80 is configured using a cross dichroic prism 81 in this embodiment. The cross dichroic prism 81 is formed by bonding four right-angle prisms, and a dielectric multilayer film reflecting R light and a dielectric multilayer film reflecting B light are formed in a cross shape on the inner surface thereof. G light is transmitted through both dielectric multilayer films.
The projection optical system 85 includes various lenses such as a zoom lens (not shown).

In the optical system 2 of the projector 1, operations after the color separation optical system 70 will be described.
The R light, G light, and B light separated by the color separation optical system 70 enter incident-side polarizers 65R, 65G, and 65B, respectively, and then enter liquid crystal panels 10R, 10G, and 10B. The liquid crystal panels 10R, 10G, and 10B modulate the incident R light, G light, and B light according to image information to form and emit modulated light.

The modulated lights of R light, G light, and B light emitted from the liquid crystal panels 10R, 10G, and 10B enter shift devices 100R, 100G, and 100B, respectively. The shift devices 100R, 100G, and 100B transmit the modulated light to the exit-side polarizing plates 60R, 60G, and 60R, 60G, while shifting the optical paths of the incident R, G, and B light beams in a time division manner. Inject to 60B.

The modulated lights of R light, G light, and B light emitted from the exit-side polarizing plates 60 R, 60 G, and 60 B enter the optical synthesizing element 80 . The optical synthesizing element 80 synthesizes the modulated light of the R light, the G light, and the B light incident from three directions, forms image light, and emits it toward the projection optical system 85 . The projection optical system 85 enlarges and projects the image light incident from the optical synthesizing element 80 onto the projection surface SC or the like.
In this manner, the projector 1 of the present embodiment performs projection with a pseudo resolution increased by the optical system 2 including the optical shift device 100 for each liquid crystal panel 10, in other words, for each color light.

FIG. 2 is a diagram simply showing the components around the optical shift device 100 of the optical system 2 of this embodiment. FIG. 9 is a simplified representation of the constituent parts corresponding to FIG. 2 in the conventional optical system 2A. In FIGS. 2 and 9, the degree of spread of light emitted from the liquid crystal panels 10R, 10G, and 10B is schematically illustrated by chain double-dashed lines. 2 and 9 also illustrate the optical plates 110 and 160 that swing to shift the optical path in the optical shift devices 100 and 150. FIG.

As shown in FIG. 2, the optical shift device 100 of this embodiment is composed of the three shift devices 100R, 100G, and 100B, the three liquid crystal panels 10R, 10G, and 10B, and the optical synthesis element 80, as described above. are placed between each. For this configuration, one conventional optical shift device 150 is arranged between the optical synthesizing element 80 and the projection optical system 85, as shown in FIG.

Conventionally, as shown in FIG. 9, an optical shift device 150 shifts the optical path of the image light after combining the modulated lights from the three liquid crystal panels 10R, 10G, and 10B by the optical combining element 80. there is However, in this embodiment, as shown in FIG. 2, the modulated light from the three liquid crystal panels 10R, 10G, and 10B is shifted by the three shift devices 100R, 100G, and 100B arranged in front of the optical synthesizing element 80. Each shifts the optical path.

Therefore, the distance between the liquid crystal panel 10 and the optical shift device 150 of the conventional optical system 2A is longer than the distance between the liquid crystal panel 10 and the optical shift device 100 of the optical system 2 of this embodiment. With this configuration, the spread of light emitted from the liquid crystal panel 10 until it reaches the optical plate 160 of the conventional optical shift device 150 is It spreads greatly compared to the spread of light at .

Further, in the conventional optical system 2A, as the distance between the member holding the liquid crystal panel 10 and the member holding the optical shift device 150 increases, the number of intervening parts increases and the cumulative tolerance during assembly also increases. . Due to these factors, conventionally, the shape of the swinging optical plate 160 of the optical shifting device 150 is changed to the shape of the swinging optical plate 110 of the optical shifting device 100 in order to pick up the spread image light and compensate for the accumulated tolerance. I had to make it bigger.

In this embodiment, by shortening the distance between the liquid crystal panel 10 and the optical shift device 100 compared to the conventional art, it is possible to suppress the spread of light (modulated light) and also suppress the cumulative tolerance. Therefore, the shape of the swinging optical plate 110 of the optical shift device 100 can be made smaller than the shape of the conventional optical plate 160 .

FIG. 3 is a perspective view showing the configuration of the optical shift device 100 of this embodiment. The configuration of the optical shift device 100 will be described with reference to FIG.
Since the shift devices 100R, 100G, and 100B constituting the optical shift device 100 are configured in the same manner, the shift device 100G will be described below.

The shift device 100G includes a movable portion 111 having a rectangular optical plate 110, an outer frame 115 swingably supporting the movable portion 111, a fixed portion 112 swingably supporting the outer frame 115, and a movable portion. and an actuator 113 for swinging the actuator 111 around the first swing axis J1 and the second swing axis J2 via the outer frame 115 . The shift device 100G has a first swing axis J1 aligned with the X axis and a second swing axis J2 aligned with the Z axis. The shift device 100G uses a glass plate in this embodiment as the optical plate 110 that transmits the modulated light emitted from the liquid crystal panel 10G. It should be noted that the optical plate 110 may be made of any material other than the glass plate, as long as the material has optical transparency and refracts the modulated light.

The movable portion 111 includes an optical plate 110 and a rectangular inner frame 114 that holds the optical plate 110 . The inner frame 114 is connected to the outer frame 115 via a first shaft portion 114a and a second shaft portion 114b arranged on the first swing axis J1. The outer frame 115 is a rectangular frame member surrounding the inner frame 114 . The fixed part 112 is a plate-shaped frame, and has an opening 112a in which the optical plate 110, the inner frame 114, the outer frame 115, and the actuator 113 are arranged. The outer frame 115 is connected to the fixed portion 112 via a third shaft portion 115c and a fourth shaft portion 115d arranged on the second swing axis J2. Thereby, the movable part 111 is supported via the outer frame 115 so as to be able to swing about the first swing axis J1 and the second swing axis J2.

The actuator 113 includes a first actuator 116 that swings the movable portion 111 around the first swing axis J1, and a second actuator 117 that swings the movable portion 111 and the outer frame 115 around the second swing axis J2. . The first actuator 116 is a magnetic drive mechanism comprising a magnet 116a and a coil 116b facing each other along the Z-axis. The first actuator 116 is arranged in the center portion of the movable portion 111 along the X-axis in the +Z direction. Specifically, the magnet 116 a of the first actuator 116 is fixed to the inner frame 114 and the coil 116 b is fixed to the fixing portion 112 .

The second actuator 117 comprises a first magnetic drive mechanism 117A and a second magnetic drive mechanism 117B. As shown in FIG. 3, the first magnetic drive mechanism 117A is arranged in the +X direction of the first actuator 116, and the second magnetic drive mechanism 117B is arranged in the -X direction of the first actuator . The outer frame 115 includes a first projecting portion 115a and a second projecting portion 115b projecting in the +Y direction. The first magnetic drive mechanism 117A and the second magnetic drive mechanism 117B apply driving force around the second swing axis J2 to the outer frame 115 and the movable portion 111 via the first protrusion 115a and the second protrusion 115b. .

The first magnetic drive mechanism 117A and the second magnetic drive mechanism 117B each include a magnet 117a and a coil 117b facing each other along the X-axis. The magnet 117a of the first magnetic drive mechanism 117A and the magnet 117a of the second magnetic drive mechanism 117B are fixed to the first projecting portion 115a and the second projecting portion 115b, respectively. The coil 117b of the first magnetic driving mechanism 117A is fixed to the +X direction edge of the opening 112a, and the coil 117b of the second magnetic driving mechanism 117B is fixed to the −X direction edge of the opening 112a.

The three optical plates 110 constituting the optical shift device 100 as described above are arranged between each liquid crystal panel 10 and the optical synthesizing element 80 . The projector 1 of the present embodiment shifts the optical path of the modulated light using the optical plate 110, that is, performs so-called image shift, thereby projecting image light having a resolution higher than that of the liquid crystal panel 10 onto the projection surface SC. For example, if the liquid crystal panel 10 is full high definition, a 4K image can be displayed.

4A and 4B are explanatory diagrams showing the shift of the image projection position due to the optical path shift of the optical shift device 100. FIG. FIG. 5 is a diagram showing projection pixels Pa, Pb, Pc, and Pd displayed on the projection surface SC by one pixel Px. FIG. 6 is a block diagram showing a schematic configuration of the control system of the projector 1. As shown in FIG.

4 and 5 show the positional relationship in which one pixel Px corresponding to the pixel 40 shown in FIG. 6 is projected onto the projection surface SC. The X-axis and Z-axis are shown as being installed in a direction perpendicular to the . Also, the dashed line shown on the projection surface SC in FIG. 5 is provided to indicate the size of the projected pixel when emitted by the pixel when realizing 4K resolution without using the optical shift device 100. Yes, but not actually displayed.
3 to 6, the principle of high resolution by shifting the optical path of the optical shift device 100 will be briefly described.

The optical shift device 100 allows the modulated light modulated by the liquid crystal panel 10 to enter. The optical shift device 100 shifts the optical path or optical axis of the modulated light using refraction by displacing the posture of the plate-like optical plate 110 (glass plate) with the actuator 113 . In this embodiment, the operation of shifting the optical path of modulated light is referred to as "optical path shift".

The optical shift device 100 oscillates the optical plate 110 around a first oscillation axis J1 that intersects the optical path and around a second oscillation axis J2 that intersects the optical path and intersects the first oscillation axis J1. . When the optical plate 110 swings around the second swing axis J2, the optical path of the light incident on the optical plate 110 shifts along the X-axis. When the optical plate 110 swings around the first swing axis J1, the optical path of the light incident on the optical plate 110 shifts along the Z-axis intersecting the X-axis. As a result, the pixels Px projected (displayed) on the projection surface SC are displayed in a state of being shifted to the X-axis and the Z-axis intersecting the X-axis. Note that the pixel Px corresponds to the pixel 40[i,j] shown in FIG.

By combining the X-axis optical path shift and the Z-axis optical path shift, the projector 1 increases the apparent number of pixels and increases the resolution of the image projected onto the projection surface SC. For example, as shown in FIG. 4, the pixel Px is sequentially moved by half a pixel along the X axis and the Z axis, that is, to a position shifted by half of the pixel Px.

As a result, in the present embodiment, the image projection position on the projection surface SC can be shifted from the image projection position P1 to the image projection position P2 by half a pixel in the X-axis (+X direction). Further, it is possible to shift the image projection position P2 to the image projection position P3 shifted by half a pixel along the Z axis (-Z direction). Further, it is possible to shift the image projection position P3 to the image projection position P4 shifted by half a pixel along the X axis (-X direction).

In this embodiment, the drive circuit 20 writes the display contents corresponding to the projection pixels Pa, Pb, Pc, and Pd at the image projection positions P1, P2, P3, and P4 to the pixels Px of the liquid crystal panels 10, respectively. In this embodiment, after that, the optical shift device 100 shifts the optical path for each color light, and the image from the pixel Px is projected onto the image projection positions P1, P2, P3, and P4 at fixed time intervals. As a result, a total of four projection pixels Pa, Pb, Pc, and Pd, two pixels in the X direction and two pixels in the Z direction, are displayed.

Specifically, the driving circuit 20 writes to the pixel Px (the pixel 40[i, j]), and the optical shift device 100 shifts the optical path of the light emitted from the pixel 40[i, j], so that the projection surface SC Above are the projected pixel Pa corresponding to the image projection position P1, the projected pixel Pb corresponding to the image projected position P2, the projected pixel Pc corresponding to the image projected position P3, and the projected pixel Pd corresponding to the image projected position P4. and is displayed.

As shown in FIG. 6, the control system of the projector 1 includes three liquid crystal panels 10R, 10G, and 10B that constitute the liquid crystal panel 10 (light modulation element), a control unit 50, a storage unit 53, and an optical shift device drive. a portion 55; three shift devices 100R, 100G and 100B forming the optical shift device 100; and three temperature sensors 56R, 56G and 56B forming the temperature sensor .

Note that the temperature sensor 56G corresponds to the first temperature sensor. Temperature sensor 56R corresponds to a second temperature sensor. Temperature sensor 56B corresponds to a third temperature sensor. A temperature sensor 56G detects the temperature of the liquid crystal panel 10G as the first liquid crystal panel. Also, the temperature sensor 56R detects the temperature of the liquid crystal panel 10R as the second liquid crystal panel. Also, the temperature sensor 56B detects the temperature of the liquid crystal panel 10B as the third liquid crystal panel.

The liquid crystal panel 10 includes a display section 30 in which a plurality of pixels 40 are arranged, and a drive circuit 20 that drives each pixel 40 . In the display section 30 of the liquid crystal panel 10, M scanning lines 32 extending in the V direction and N data lines 34 extending in the VI direction crossing the V direction are formed. Here, M and N are integers of 2 or more. A plurality of pixels 40 are provided in the display section 30 so as to correspond to intersections between the scanning lines 32 and the data lines 34 . Therefore, the pixels 40 are arranged in M rows×N columns.

In the following description, in order to distinguish and describe a specific pixel 40, the pixel 40 corresponding to the intersection of the i-th scanning line 32 and the j-th data line 34 is expressed as [i,j]. . Here, i is an integer satisfying 1≤i≤M, and j is an integer satisfying 1≤j≤N.

The pixel 40[i,j] includes, as an equivalent circuit, a liquid crystal element CL, a selection switch (not shown), and a storage capacitor (not shown). The liquid crystal element CL has a structure in which liquid crystal is sandwiched between a pixel electrode and a common electrode (both are not shown).

The drive circuit 20 includes a scanning line drive circuit 22 and a data line drive circuit 24, and writes a voltage corresponding to a data signal to each pixel 40. FIG. Specifically, the scanning line driving circuit 22 of the driving circuit 20 generates the scanning signals Y[1], Y[2], Y[3], . , M-th scanning lines 32 in order. The data line driving circuit 24 supplies data signals VD[1] to VD[N] to the data lines 34 of the first to Nth columns in synchronization with the selection of the scanning lines 32 by the scanning line driving circuit 22. .

The pixels 40 arranged in M rows and N columns of the liquid crystal panel 10 have the same electrical configuration. Therefore, taking the pixel 40[i,j] in row i and column j as an example, the pixel 40[i,j] is such that the scanning signal Y[i] is at the active level (H level) in this embodiment. The voltage of the data signal VD[j] at that time is written, and the transmittance corresponding to the voltage is obtained.

The control unit 50 includes an image processing unit 51 and a timing signal generation unit 52, and controls the liquid crystal panel based on a synchronizing signal and a video signal Vin supplied in synchronization with the synchronizing signal from a higher-level circuit (not shown). It controls writing by the drive circuit 20 in 10R, 10G, and 10B, and the supply of the data signal VD in synchronization with the writing. Further, the control section 50 controls the optical path shift of the shift devices 100R, 100G, and 100B via the optical shift device driving section 55 in response to writing.

The timing signal generator 52 generates control signals CLT and CLD based on the synchronization signal, supplies the generated control signal CLT to the drive circuit 20 and the image processor 51, and uses the generated control signal CLD to drive the optical shift device. 55.

In this embodiment, one frame period F is divided into four field periods. Then, the timing signal generator 52 controls the drive circuit 20 so that a voltage corresponding to the data signal VD is written to each of the pixels 40 of M rows and N columns in each field period. Further, in this embodiment, the timing signal generator 52 corresponds to each liquid crystal panel 10 (10R, 10G, 10B) in consideration of the voltage applied to the liquid crystal and the response time due to the temperature of each liquid crystal panel 10. The shift devices 100 R, 100 G, and 100 B are generated with different drive start timings for optical path shift, and the control signal CLD is supplied to the optical shift device driving section 55 .

Here, one frame period F is the period required for displaying one frame of image defined by the video signal Vin on the liquid crystal panel 10 . In this embodiment, the frame frequency is 60 Hz. Thus, the frame period is approximately 16.7 ms, the field period frequency is 240 Hz, and the field period period is approximately 4.1 ms. Further, the projector 1 displays an image for one frame on the projection surface SC by displaying an image on the liquid crystal panel 10 in each of the four field periods. The projector 1 of the present embodiment displays 4K resolution, ie, 3840 columns in the horizontal direction×2160 rows in the vertical direction, on the projection surface SC using a simulated resolution.

In addition, the timing signal generator 52 causes the image processor 51 to process the video signal Vin according to the control signal CLT, and generates the data signal VD corresponding to the projection pixel at the position to be shifted in each field period. is supplied in accordance with the writing of Although FIG. 6 is simplified, in reality, the data signal of the R light component of the video signal Vin subjected to signal processing is supplied to the liquid crystal panel 10R. Similarly, of the video signal Vin, the data signal of the G light component that has undergone signal processing is supplied to the liquid crystal panel 10G. Similarly, the data signal of the B light component of the video signal Vin subjected to signal processing is supplied to the liquid crystal panel 10B.

Here, the characteristics of liquid crystal panels including the liquid crystal panel 10 will be briefly described.
In the liquid crystal panel 10, the response characteristics of the liquid crystal depend on temperature, and the response is low at low temperatures and high at high temperatures.

In the liquid crystal panel 10, in the relationship between the applied voltage and the transmittance, the voltage (Vpeak) at which the transmittance becomes maximum decreases for the R light, the G light, and the B light, as the wavelength of the color light becomes shorter. The voltage at which the transmittance is maximized is the lowest for the B light, followed by the G light, and then the R light. The degree of misalignment that occurs at the black-and-white boundary (the boundary between the regions where the transmittance is maximum and minimum) increases with the length of the wavelength of the colored light. The order is G light and finally B light. The responsiveness of the liquid crystal (liquid crystal panel 10) is proportional to the magnitude of the voltage (Vpeak) at which the transmittance is maximized. order of light.

From such a physical background of liquid crystal, in the present embodiment, a table of applied voltages optimized for each of the liquid crystal panels 10R, 10G, and 10B is stored in the storage unit 53 (FIG. 6), which will be described later. More specifically, it has a table recording the applied voltage (maximum applied voltage) optimized for the characteristics of each of the liquid crystal panels 10R, 10G, and 10B and the temperature. The table also records data corresponding to the maximum applied voltage and temperature for each display mode such as so-called cinema mode, sports mode, game mode, and the like.

In the projector 1 of this embodiment, optical shift devices 100 (shift devices 100R, 100G, 100B) are arranged between the liquid crystal panels 10 (10R, 10G, 10B) and the optical synthesizing element 80, respectively. The control unit 50 controls the application timing of the applied voltage and the driving start timing of the shift that shifts the optical path between each liquid crystal panel 10 and each corresponding optical shift device 100 . Specifically, since the response characteristics (response time) of the liquid crystal until reaching a predetermined transmittance differ depending on the temperature of the liquid crystal panel 10 (liquid crystal), the controller 50 controls the timing of applying the applied voltage and the temperature of the liquid crystal. and the driving start timing of the shift for shifting the optical path.

The storage unit 53 stores, as a table, first data recording the relationship between the maximum applied voltage and the temperature of the liquid crystal panel 10G as the first liquid crystal panel. The storage unit 53 also stores second data as a table that records the relationship between the maximum applied voltage and the temperature of the liquid crystal panel 10R as the second liquid crystal panel. The storage unit 53 also stores third data as a table that records the relationship between the maximum applied voltage and the temperature of the liquid crystal panel 10B as the third liquid crystal panel. The temperature data of each liquid crystal panel 10 includes, for example, the response time data of the liquid crystal as the response characteristics of the liquid crystal depending on the temperature of each liquid crystal panel 10 .

In this embodiment, the temperature of each liquid crystal panel 10 ( 10 R, 10 G, 10 B) is detected by each temperature sensor 56 ( 56 R, 56 G, 56 B) and the detected value is output to the control section 50 . In the present embodiment, the timing signal generator 52 generates the control signal CLT, and also receives the first data, second data, and third data of the table stored in the storage unit 53 and input from each temperature sensor 56. Based on the temperature information of each liquid crystal panel 10, a control signal CLD for each shift device 100R, 100G, 100B in each field period is generated.

The image processing unit 51 processes the video signal Vin according to the control signal CLT. Specifically, the image processing unit 51 supplies the data signal VD corresponding to the projection pixel at the position to be shifted in each field period in accordance with the writing of the driving circuit 20 . The optical shift device driver 55 shifts the optical paths of the shift devices 100R, 100G, and 100B at respective timings according to the control signal CLD.

FIG. 7 is a diagram showing the relationship between the optical path shift operation of the optical shift device 100 and the write operation to the pixel 40 by the drive circuit 20. As shown in FIG.
The relationship between the optical path shift operation of the optical shift device 100 (shift devices 100R, 100G, 100B) and the write operation to the pixels 40[i, j] of the liquid crystal panel 10 (liquid crystal panels 10R, 10G, 10B) will be described. .

The one-frame period F is the period required for the liquid crystal panel 10 to display an image for one frame defined by the video signal Vin, as described above. In this embodiment, one frame period F is divided into four field periods Ta, Tb, Tc, and Td.

FIG. 7 shows the operation of the optical shift device 100 and the operation of the driving circuit 20 during part of the frame period F[k−1], frame period F[k], and part of the frame period F[k+1]. . k is an integer of 2 or more. A frame period F[1] is a frame period when the projector 1 starts driving.

As shown in FIG. 7, the scanning line drive circuit 22 sequentially selects the scanning lines 32 from the 1st row to the M-th row, and the image processing unit 51 scans the selected scanning line 32 for one row. data signal VD to the data line driving circuit 24 . The data line driving circuit 24 supplies the supplied data signal VD for one row to the data lines 34 of the corresponding columns.

The start time of the frame period is the time when the scanning line 32 of the first row is selected for writing a positive signal corresponding to the gradation of the projection pixel Pa to the image projection position P1. The start time of the field period Ta is the same as the start time of the frame period F. The start time of the field period Tb is the time when the scanning line 32 of the first row is selected for writing a positive signal corresponding to the gradation of the projection pixel Pb to the image projection position P2. The start time of the field period Tc is the time when the scanning line 32 of the first row is selected for writing a positive signal corresponding to the gradation of the projection pixel Pc to the image projection position P3. The start time of the field period Td is the time when the scanning line 32 of the first row is selected for writing a positive signal corresponding to the gradation of the projection pixel Pd to the image projection position P4.

The positive signal is, for example, a signal of +5V or the like, and in the pixel 40 of the liquid crystal panel 10, it is a signal in which a pixel electrode (not shown) has a higher potential than a common electrode. Further, as will be described later, the negative signal is, for example, a signal of -5V or the like, and is a signal in which the potential of the pixel electrode is lower than that of the common electrode.

In FIG. 7, the scanning line to be selected means that the number of rows of the scanning line 32 from the 1st row to the Mth row is plotted on the vertical axis, and the passage of time is plotted on the horizontal axis, and the scanning signal Y[1] FIG. 10 is a diagram showing the temporal transition of scanning lines selected by ˜Y[M]; If the scanning line selection period is indicated by a black line for each scanning line, the scanning lines 32 are sequentially and exclusively selected one row at a time. Move to line. For this reason, a collection of black lines indicating selected scanning lines is indicated by continuous points sloping to the right as time passes. In FIG. 7, the selected scanning line is indicated by a solid line sloping downward to the right for the sake of simple representation.

Also, the time required for the optical shift device 100 to shift the emission region A from the image projection position P1 to the image projection position P2, and the time required for the emission region A to shift from the image projection position P2 to the image projection position P3. , the time required for the emission area A to shift from the image projection position P3 to the image projection position P4 is the same as the time required for the emission area A to shift from the image projection position P4 to the image projection position P1. and In this embodiment, the time required for the optical shift device 100 to shift the optical path is assumed to be 2 ms, for example. In addition, the emission area A is an emission area on the projection surface SC by the emitted light from the pixel 40[i, j].

In this embodiment, the driving of the optical shift device 100 for optical path shift is started after about 1/2 of the time has elapsed from the start of each of the field periods Ta, Tb, Tc, and Td. More specifically, as shown in FIG. 7, the shift devices 100R, 100G, and 100B have different drive start times for optical path shift. This is because the response characteristics of the liquid crystal, which are different for each color light of the liquid crystal panel 10, are taken into consideration. Specifically, when a signal (applied voltage) is written, the liquid crystal panel 10 does not reach a predetermined transmittance at that instant, and it takes time to reach a predetermined transmittance corresponding to the applied voltage. The optical path shift drive start times of the shift devices 100R, 100G, and 100B are staggered in accordance with the time at which a predetermined transmittance is obtained.

Here, in the above description, as a characteristic of the liquid crystal panel 10, the responsiveness of the liquid crystal is proportional to the magnitude of the voltage (Vpeak) at which the transmittance is maximized. It has been explained that the G light is followed by the B light. However, when using the projector 1, it is necessary to balance colors in various display modes. By adjusting the color balance, the applied voltage (maximum applied voltage) corresponding to the colored light is set. The driving start time of the optical path shift is also changed corresponding to the set maximum applied voltage.

As an example, the optical path shift driving start times of the shift devices 100R, 100G, and 100B shown in FIG. , drive start time (driving start timing) when color balance is achieved.

Specifically, as described above, the R light has a low voltage (Vpeak) that maximizes the transmittance, so the maximum applied voltage is set to about 5V, for example. The G light has a slightly lower transmittance than the R light. For example, the maximum applied voltage is set to about 3 V to match the transmittance of about 70%. Also, the B light is used with a transmittance of, for example, around 100%, and the maximum applied voltage is set to about 3.5V.

Thus, in each display mode, the maximum applied voltage for each color light is determined by balancing the colors. When forming an image, the maximum applied voltage is used as a reference, and a voltage corresponding to the gradation of each color light is applied within a range that does not exceed the maximum applied voltage.

As described above, the response speed of the liquid crystal increases as the applied voltage increases. Therefore, in the present embodiment, as shown in FIG. The speed is in the order of R light (5V) first, B light (3.5V), and finally G light (3V). In other words, the speed of the driving start time of the optical path shift is in the order of the shift device 100R first, then the shift device 100B, and finally the shift device 100G.

In this embodiment, as shown in FIG. 7, the shift device 100R for R light starts driving the optical path shift after about 1/2 of the time has elapsed from the start time in each of the field periods Ta, Tb, Tc, and Td. . Then, the shift device 100B for B light starts driving the optical path shift later than the driving start time of the optical path shift of the shift device 100R for R light. After the shift device 100B for B light starts driving the shift device 100B for optical path shift, the shift device 100G for G light starts driving the shift device 100G for optical path. In this way, by shifting the driving start time of the optical shift device 100 according to the maximum applied voltage and the response characteristic of the liquid crystal of each color light, the pixels 40[i,j] of each color light having a predetermined transmittance. The optical path of the light emitted from is shifted.

If the optical path is shifted by the shift device 100G before the transmittance reaches the predetermined transmittance, the orientation of the liquid crystal panel 10 is likely to be defective, and the resolution varies among the liquid crystal panels 10, resulting in a decrease in contrast. It becomes a factor of deterioration of image quality, such as

As shown in FIG. 6 , the timing signal generator 52 controls the optical path shift of the optical shift device 100 via the optical shift device driver 55 . Specifically, as shown in FIG. 7, the emission area A is at the image projection position P4 until the time when the field period Ta starts and the shift devices 100R, 100G, and 100B start driving the optical path shift operations. It is fixed, and each shifts from the image projection position P4 to the image projection position P1 along the +Z direction by about 2 ms.

As shown in FIG. 7, during the period when the i-th scanning line 32 is first selected in the field period Ta of the frame period F[k], the driving circuit 20 controls the pixels of the liquid crystal panels 10R, 10G, and 10B. 40[i, j] is written with a positive signal corresponding to the gradation of the projection pixel Pa for the image projection position P1. The character string "VP1+" in the voltage holding state of the pixel 40[i,j] shown in FIG. Indicates the voltage of a positive signal.

Within the field period Ta of the frame period F[k], during the period when the i-th scanning line 32 is next selected, the driving circuit 20 causes the pixels 40[i, j] of the liquid crystal panels 10R, 10G, and 10B to , a negative signal corresponding to the gradation of the projection pixel Pa is written to the image projection position P1. The character string "VP1-" in the voltage holding state of the pixel 40[i,j] shown in FIG. indicates the voltage of the negative signal.

In addition, the emission area A is fixed at the image projection position P1 from the start of the field period Tb to the time when the shift devices 100R, 100G, and 100B start driving the optical path shift operations, and is fixed at the image projection position P1 until about 2 ms elapses. , from the image projection position P1 to the image projection position P2 along the +X direction.

As shown in FIG. 7, during the period in which the i-th scanning line 32 is first selected in the field period Tb of the frame period F[k], the drive circuit 20 controls the pixels of the liquid crystal panels 10R, 10G, and 10B. 40[i, j] is written with a positive signal corresponding to the gradation of the projection pixel Pb for the image projection position P2. The character string "VP2+" indicates the voltage of the positive signal corresponding to the gradation of the projection pixel Pb with respect to the image projection position P2 held by the pixel 40[i,j].

As shown in FIG. 7, within the field period Tb of the frame period F[k], during the period when the i-th scanning line 32 is next selected, the drive circuit 20 controls the pixels of the liquid crystal panels 10R, 10G, and 10B. 40[i, j] is written with a negative signal corresponding to the gradation of the projection pixel Pb for the image projection position P2. The character string "VP2-" indicates the voltage of the negative signal corresponding to the gradation of the projection pixel Pb with respect to the image projection position P2 held by the pixel 40[i,j].

In addition, the emission area A is fixed at the image projection position P2 from the start of the field period Tc to the time when the shift devices 100R, 100G, and 100B start the optical path shift operations, and by about 2 ms, - each shift from image projection position P2 to image projection position P3 along the Z direction;

As shown in FIG. 7, during the period in which the i-th scanning line 32 is first selected in the field period Tc of the frame period F[k], the drive circuit 20 controls the pixels of the liquid crystal panels 10R, 10G, and 10B. 40[i, j] is written with a positive signal corresponding to the gradation of the projection pixel Pc for the image projection position P3. The character string "VP3+" indicates the voltage of the positive signal corresponding to the gradation of the projection pixel Pc with respect to the image projection position P3 held by the pixel 40[i,j].

As shown in FIG. 7, within the field period Tc of the frame period F[k], during the period when the i-th scanning line 32 is next selected, the drive circuit 20 controls the pixels of the liquid crystal panels 10R, 10G, and 10B. 40[i, j] is written with a negative signal corresponding to the gradation of the projection pixel Pc for the image projection position P3. The character string "VP3-" indicates the voltage of the negative signal corresponding to the gradation of the projection pixel Pc with respect to the image projection position P3 held by the pixel 40[i,j].

In addition, the emission region A is fixed at the image projection position P3 from the start of the field period Td until the time when the shift devices 100R, 100G, and 100B start the optical path shift operations. Each shift from the image projection position P3 to the image projection position P4 along the -X direction.

As shown in FIG. 7, during the period in which the i-th scanning line 32 is first selected in the field period Td of the frame period F[k], the driving circuit 20 controls the pixels of the liquid crystal panels 10R, 10G, and 10B. 40[i, j] is written with a positive signal corresponding to the gradation of the projection pixel Pd for the image projection position P4. The character string "VP4+" indicates the voltage of the positive signal corresponding to the gradation of the projection pixel Pd with respect to the image projection position P4 held by the pixel 40[i,j].

As shown in FIG. 7, within the field period Td of the frame period F[k], during the period when the i-th scanning line 32 is next selected, the drive circuit 20 controls the pixels of the liquid crystal panels 10R, 10G, and 10B. 40[i, j] is written with a negative signal corresponding to the gradation of the projection pixel Pd for the image projection position P4. Note that the character string "VP4-" indicates the voltage of the negative signal corresponding to the gradation of the projection pixel Pd with respect to the image projection position P4 held by the pixel 40[i,j].

As shown in FIG. 7, in the four field periods, the drive circuit 20 writes a positive signal to the pixels 40 in the period when the scanning line 32 is selected first, and then writes the positive signal in the period when the scanning line 32 is selected. Now, write a negative signal to the pixel 40 . Thus, the drive circuit 20 balances the polarities within one frame period F by reversing the polarities within one field period. By writing positive and negative signals to the pixels 40 of the liquid crystal panel 10, so-called burn-in of the liquid crystal panel 10 is suppressed.

As shown by the projection surface SC in FIG. 7, the range of the projection pixels Pa at the image projection position P1 does not match the range of the emission area A at the image projection position P1. More specifically, the range of the projection area A, which is the image projection position P1, includes the entire range of the projection pixels Pa at the image projection position P1, the entire range of the projection pixels Pb at the image projection position P2, and the projection pixel Pb at the image projection position P3. It includes the full range of pixels Pc and the full range of projected pixels Pd at image projection position P4.

As described above, since the range of the projection pixels Pa, Pb, Pc, and Pd at the position of the display target does not match the range of the image projection positions P1, P2, P3, and P4, which is the emission area A, on the projection surface SC, The displayed image is distorted. However, since this distortion is such a fine difference that the human eye cannot visually recognize the difference due to this distortion on the projection surface SC, there is no problem in displaying the image.

Since the shape of the image displayed on the projection surface SC is distorted as described above, this shape does not necessarily match the shape of the image indicated by the video signal Vin. However, the image displayed on the projection surface SC contains all the information that the video signal Vin has, and no information is lost.

According to this embodiment, the following effects can be obtained.

The projector 1 of this embodiment includes a first light modulation element (liquid crystal panel 10G) that modulates a first color light (G light) and a second light modulation element (liquid crystal panel 10R) that modulates a second color light (R light). and a third light modulation element (liquid crystal panel 10B) that modulates the third color light (B light). The projector 1 also includes an optical synthesizing element 80 (cross dichroic prism 81 ) and a projection optical system 85 for projecting the image light from the optical synthesizing element 80 . The projector 1 also includes a first optical shift device 100 (shift device 100G) arranged between the liquid crystal panel 10G and the optical synthesizing element 80 to shift the optical path of the G light modulated by the liquid crystal panel 10G. The projector 1 also includes a second optical shift device 100 (shift device 100R) arranged between the liquid crystal panel 10R and the optical synthesizing element 80 to shift the optical path of the R light modulated by the liquid crystal panel 10R. The projector 1 also includes a third optical shift device 100 (shift device 100B) arranged between the liquid crystal panel 10B and the optical synthesizing element 80 to shift the optical path of the B light modulated by the liquid crystal panel 10B.
With this configuration, the distance between each liquid crystal panel 10 (liquid crystal panels 10R, 10G, 10B) and each optical shift device 100 (shift device 100R, 100G, 100B) is shorter than in the conventional configuration. Spreading of image light from the panels 10R, 10G, 10B to the shift devices 100R, 100G, 100B can be suppressed. Also, the cumulative tolerance due to assembly is reduced. Therefore, it is not necessary to increase the size of the oscillating optical plate 110 of the optical shift device 100, and the increase in size of the optical shift device 100 can be suppressed compared to the conventional optical shift device 150. FIG. Further, by suppressing an increase in the size of the optical shift device 100 and reducing the size of the optical plate 110, it is possible to improve the followability such as the response speed of the oscillation of the optical plate 110. FIG.

In the projector 1 of this embodiment, the first light modulation element is the first liquid crystal panel (liquid crystal panel 10G), the second light modulation element is the second liquid crystal panel (liquid crystal panel 10R), and the third light modulation element is The element is the third liquid crystal panel (liquid crystal panel 10B).
With this configuration, spread of image light to the optical shift device 100 can be suppressed in the light modulation element using the liquid crystal panel 10 .

In the projector 1 of the present embodiment, the first polarizing plate (exit side A polarizing plate 60G) is provided. In addition, the projector 1 includes a second polarizing plate (emission-side polarizing plate 60R). The projector 1 also includes a third polarizing plate (emission-side polarizing plate 60B).
With this configuration, light whose optical path has been changed by the optical shift device 100 is incident on the first polarizing plate, the second polarizing plate, and the third polarizing plate. Temperature rise of the polarizing plate and the third polarizing plate can be suppressed.

In the projector 1 of the present embodiment, the storage unit 53 stores the first data recording the relationship between the maximum applied voltage and the temperature of the first liquid crystal panel (liquid crystal panel 10G) and the maximum voltage of the second liquid crystal panel (liquid crystal panel 10R). Second data recording the relationship between applied voltage and temperature, and third data recording the relationship between maximum applied voltage and temperature of the third liquid crystal panel (liquid crystal panel 10B) are stored. The control unit 50 controls the timing to start driving the first optical shift device (shift device 100G) based on the first data stored in the storage unit 53, and controls the timing to start driving the first optical shift device (shift device 100G) based on the second data stored in the storage unit 53. to control the timing to start driving the second optical shift device (shift device 100R), and based on the third data stored in the storage unit 53, the timing to start driving the third optical shift device (shift device 100B). to control.
With this configuration, the response characteristics (response time) due to temperature with respect to the maximum applied voltage are taken into consideration based on the data on the maximum applied voltage and temperature of each liquid crystal panel 10 (liquid crystal panels 10R, 10G, and 10B), and each optical shift device 100 The drive start timing of (shift devices 100R, 100G, 100B) can be controlled respectively. Therefore, it is possible to prevent the timing deviation between the image display and the shift operation, and to suppress the deterioration of the image quality.

The projector 1 of this embodiment includes a first temperature sensor (temperature sensor 56G) that detects the temperature of the first liquid crystal panel (liquid crystal panel 10G) and a second temperature sensor that detects the temperature of the second liquid crystal panel (liquid crystal panel 10R). A sensor (temperature sensor 56R) and a third temperature sensor (temperature sensor 56B) that detects the temperature of the third liquid crystal panel (liquid crystal panel 10B) are provided. Further, the control unit 50 controls the first optical shift device 100 (shift device 100G), the second optical shift device 100 (shift device 100R), and the third optical shift device 100 (shift device 100B).
With this configuration, the optical shift devices 100 (shift devices 100R, 100G, 100B) start driving in response to changes in the response characteristics to the applied voltage caused by temperature changes in the liquid crystal panels 10 (liquid crystal panels 10R, 10G, 10B). By controlling the timing, it is possible to prevent a timing lag between the image display and the shift operation, thereby suppressing the deterioration of the image quality.

2. Second Embodiment A projector 1A according to this embodiment will be described.
FIG. 8 is a diagram showing a schematic configuration of the optical system 2A of the projector 1A according to this embodiment.

As shown in FIG. 8, the optical system 2A of this embodiment differs from the optical system 2 of the first embodiment in that the optical shift device 100 is used only for the shift device 100G for G light. It is that you are. In other words, in the optical system 2A of this embodiment, the optical shift device 100 is not used for R light and B light. Other configurations are similar to those of the first embodiment, and similar configurations are denoted by similar reference numerals.

Here, in the projector 1A, for example, when the intensity of the R light, the G light, and the B light are balanced such as the white balance of the projected image, the contribution rate of the resolution differs for each color light, and among them, the contribution of the G light. high rate. Therefore, the shift device 100G shifts the optical path of the liquid crystal panel 10G for G light, thereby improving the pseudo-resolution.

According to this embodiment, the following effects can be obtained.

The projector 1A of this embodiment includes a first light modulation element (liquid crystal panel 10G) that modulates G light, a second light modulation element (liquid crystal panel 10R) that modulates R light, and a third light that modulates B light. and a modulation element (liquid crystal panel 10B). The projector 1A also includes an optical synthesizing element 80 that synthesizes the light modulated by the liquid crystal panel 10G, the light modulated by the liquid crystal panel 10R, and the light modulated by the liquid crystal panel 10B to form image light; and a projection optical system 85 for projecting image light. The projector 1A includes an optical shift device 100 (shift device 100G) arranged between the liquid crystal panel 10G and the optical synthesizing element 80 to shift the optical path of the light modulated by the liquid crystal panel 10G.
According to this configuration, by improving the pseudo resolution with the shift device 100G for the liquid crystal panel 10G for G light whose contribution to resolution is higher than that for R light and B light, for example, The image quality can be improved even when the alignment defect of the liquid crystal panel 10R is large. Further, since the distance between the liquid crystal panel 10G and the shift device 100G is short, the accumulated tolerance due to assembly is small, and the spread of image light from the liquid crystal panel 10G to the shift device 100G can be suppressed. Therefore, it is not necessary to increase the size of the oscillating optical plate 110 of the shift device 100G, and it is possible to suppress the increase in size of the shift device 100G.

3. Modification 1
In the first embodiment, the optical shift device 100 that rocks the movable portion 111 around two rocking axes (the first rocking axis J1 and the second rocking axis J2) has been described. However, the present invention is not limited to this, and the present invention can also be applied to an optical shift device that rocks around one rocking axis.

4. Modification 2
In the first and second embodiments, the liquid crystal panel 10 was exemplified as an example of the light modulation element. However, the present invention is not limited to this, and can also be applied to a projector using a DLP (registered trademark) (Digital Light Processing) optical system. In this case, a DMD (registered trademark) (Digital Micromirror Device) may be used as the light modulation element. A DMD is a reflection-type light modulation element that, for example, is made up of several million aluminum mirrors with high reflectivity, and projects various images by controlling the tilt of these mirrors and the light source. be. However, since the DMD has a structure that reflects incident light, it is necessary to secure a wide angle at which this light is absorbed, and the optical plate must be larger than the light transmitted by the optical shift device. cannot be changed.

DESCRIPTION OF SYMBOLS 1... Projector 10... Liquid crystal panel 10G... First light modulation element, liquid crystal panel for G light as first liquid crystal panel 10R... Second light modulation element, liquid crystal panel for R light as second liquid crystal panel , 10B... third light modulation element, liquid crystal panel for B light as third liquid crystal panel, 50... control section, 53... storage section, 56... temperature sensor, 56G... temperature for G light as first temperature sensor Sensors 56R: temperature sensor for R light as second temperature sensor 56B: temperature sensor for B light as third temperature sensor 60G: emission-side polarizing plate for G light as first polarizing plate 60R Emission-side polarizing plate for R light as second polarizing plate 60B Ejecting-side polarizing plate for B light as third polarizing plate 80 Optical synthesizing element 85 Projection optical system 100 Optical shift device , 100G... a shift device for G light as a first optical shift device, 100R... a shift device for R light as a second optical shift device, 100B... a shift device for B light as a third optical shift device, G ... green, R ... red, B ... blue.

Claims (6)

a first light modulation element that modulates the first color light;
a second light modulation element that modulates the second color light;
a third light modulation element that modulates the third color light;
an optical synthesizing element for synthesizing the light modulated by the first light modulating element, the light modulated by the second light modulating element, and the light modulated by the third light modulating element to form image light;
a projection optical system that projects the image light from the optical synthesizing element;
a first optical shift device disposed between the first light modulation element and the optical synthesizing element for shifting an optical path of the light modulated by the first light modulation element;
a second optical shift device disposed between the second light modulation element and the optical synthesizing element for shifting an optical path of the light modulated by the second light modulation element;
and a third optical shift device disposed between the third light modulation element and the optical synthesizing element for shifting an optical path of the light modulated by the third light modulation element. The projector according to claim 1,
the first light modulation element is a first liquid crystal panel,
the second light modulation element is a second liquid crystal panel,
The projector, wherein the third light modulation element is a third liquid crystal panel. The projector according to claim 2,
a first polarizing plate disposed between the first optical shift device and the optical synthesizing element on the exit side of the first liquid crystal panel;
a second polarizing plate disposed between the second optical shift device and the optical synthesizing element on the exit side of the second liquid crystal panel;
and a third polarizing plate disposed between the third optical shift device and the optical synthesizing element on the exit side of the third liquid crystal panel. The projector according to Claim 2 or Claim 3,
first data recording the relationship between the maximum applied voltage and the temperature of the first liquid crystal panel;
second data recording the relationship between the maximum applied voltage and the temperature of the second liquid crystal panel;
a storage unit storing third data recording the relationship between the maximum applied voltage and the temperature of the third liquid crystal panel;
controlling the timing of driving the first optical shift device based on the first data stored in the storage unit;
controlling the timing of driving the second optical shift device based on the second data stored in the storage unit;
and a control section that controls timing for driving the third optical shift device based on the third data stored in the storage section. The projector according to claim 4,
a first temperature sensor that detects the temperature of the first liquid crystal panel;
a second temperature sensor that detects the temperature of the second liquid crystal panel;
a third temperature sensor that detects the temperature of the third liquid crystal panel;
The controller controls the first optical shift device based on the values of the first temperature sensor, the second temperature sensor, and the third temperature sensor, and the first data, the second data, and the third data. , the timing of driving the second optical shift device and the third optical shift device. a first light modulation element that modulates green light;
a second light modulating element that modulates red light;
a third light modulation element that modulates blue light;
an optical synthesizing element for synthesizing the light modulated by the first light modulating element, the light modulated by the second light modulating element, and the light modulated by the third light modulating element to form image light;
a projection optical system that projects the image light from the optical synthesizing element;
and an optical shift device disposed between the first light modulation element and the optical synthesizing element for shifting an optical path of the light modulated by the first light modulation element.

Images