JP2012208426A - Electro-optical device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electro-optical device that suppresses a reduction in reliability thereof while enhancing a response speed of a liquid crystal when displaying a 3D image in the electro-optical device capable of switching a display between a 2D image and the 3D image.SOLUTION: An electro-optical device comprises: a liquid crystal panel 12 for displaying an image corresponding to a planar image and an image corresponding to a stereoscopic image in a switchable manner; and controller 29 for controlling temperature of the liquid crystal panel 12 such that a temperature of the liquid crystal panel 12 when displaying the image corresponding to the stereoscopic image is greater than that of the liquid crystal panel 12 when displaying the image corresponding to the planar image.

Description

  The present invention relates to an electro-optical device using a liquid crystal panel.

  Conventionally, an electro-optical device includes a liquid crystal projector (projection type electro-optical device) that displays an image projected and enlarged on a screen while modulating illumination light by a liquid crystal light valve, and illumination light from the back side of a liquid crystal panel. There is a liquid crystal monitor (direct-view type electro-optical device) that displays an image by irradiating light.

  Recently, an electro-optical device using a 2D / 3D-compatible liquid crystal capable of displaying a three-dimensional stereoscopic image (3D image) in addition to a two-dimensional planar image (2D image) has been developed. For example, in a liquid crystal projector capable of displaying 3D video, a right eye image and a left eye image corresponding to the 3D video are alternately displayed in a time-sharing manner for each frame, while the user is synchronized with switching between the right eye image and the left eye image Then, it is possible to view 3D video by wearing shutter glasses that alternately open and close the right eye and the left eye, and selectively viewing the right eye image with the right eye and the left eye image with the left eye. (For example, refer to Patent Documents 1 and 2.)

  By the way, in an electro-optical device that displays such 3D video, it is necessary to switch between a right eye image and a left eye image displayed on a liquid crystal panel at high speed. In particular, when the video signal is written in a line-sequential method, a writing delay occurs between the first line and the last line of the pixel matrix. So-called crosstalk occurs.

  In order to increase the response speed of the liquid crystal, it is conceivable to improve the liquid crystal material (for example, to reduce the viscosity), to reduce the cell gap of the liquid crystal panel, or to increase the temperature of the liquid crystal panel. However, regarding the improvement of the liquid crystal material, it is difficult to dramatically improve the material itself. On the other hand, when the cell gap is reduced, brightness cannot be obtained. On the other hand, when the temperature of the liquid crystal panel is raised, the reliability (life) is reduced.

JP 2008-306335 A JP 2009-232249 A

  The present invention has been proposed in view of such a conventional situation, and in an electro-optical device using a liquid crystal capable of switching between display of 2D video and 3D video, the liquid crystal in the case of displaying 3D video is displayed. An object of the present invention is to provide an electro-optical device that improves the response speed and suppresses a decrease in reliability.

  In order to achieve the above object, an electro-optical device according to the present invention displays a liquid crystal panel that can switch between an image corresponding to a planar video and an image corresponding to a stereoscopic video, and an image corresponding to the stereoscopic video. And a control unit that controls the temperature of the liquid crystal panel to be higher than when an image corresponding to a planar image is displayed.

  As described above, in this electro-optical device, when displaying an image corresponding to a stereoscopic image, by setting the temperature of the liquid crystal panel to be higher than when displaying an image corresponding to a planar image, The response speed of the liquid crystal can be increased, and an image corresponding to 3D video can be switched and displayed at high speed. Further, in this electro-optical device, since the temperature of the liquid crystal panel is set to be high only when displaying an image corresponding to the stereoscopic image, this liquid crystal panel is compared with the case where the temperature of the liquid crystal panel is always set to be high. It is possible to suppress a decrease in reliability.

  In addition, when the electro-optical device includes a cooling mechanism for cooling the liquid crystal panel, the control unit controls the driving of the cooling mechanism to display an image corresponding to the stereoscopic image according to the planar image. It is possible to control the temperature of the liquid crystal panel to be higher than when displaying an image.

  In addition, when the electro-optical device includes a heating mechanism for heating the liquid crystal panel, the control unit controls the driving of the heating mechanism to display an image corresponding to the stereoscopic image according to the planar image. It is possible to control the temperature of the liquid crystal panel to be higher than when displaying an image.

  The electro-optical device may include a temperature sensor that measures the temperature of the liquid crystal panel, and the control unit may control the temperature of the liquid crystal panel based on a result measured by the temperature sensor. In this case, the temperature of the liquid crystal panel can be controlled with high accuracy.

  Further, the electro-optical device opens the right eye side in a section in which the right eye image is displayed in synchronization with a liquid crystal panel that alternately displays a right eye image and a left eye image corresponding to a stereoscopic image in a time division manner. In addition, in the section in which the left eye side is blocked and the left eye image is displayed, the stereoscopic image is provided to the user wearing the glasses by providing glasses that block the right eye side and open the left eye side. Can be visually recognized.

  The electro-optical device can be applied to a projection-type electro-optical device that projects an image using the liquid crystal panel as a light valve.

  The electro-optical device can be applied to a direct-view electro-optical device that directly views the liquid crystal panel as an image display surface.

1 is a perspective view showing a liquid crystal projector according to an embodiment of the present invention. It is a figure which shows the structure of the projector main body with which the liquid-crystal projector shown in FIG. It is a figure which shows the circuit structure of the liquid crystal projector shown in FIG. 2 is a timing chart illustrating an opening / closing operation of shutter glasses included in the liquid crystal projector illustrated in FIG. 1. It is sectional drawing which shows the structure which provided the heater in the liquid crystal panel.

Hereinafter, an embodiment of the present invention will be described with reference to FIGS.
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.

  A liquid crystal projector according to an embodiment of the present invention is an example of a 2D / 3D-compatible electro-optical device that can display a three-dimensional stereoscopic image (3D image) in addition to a two-dimensional planar image (2D image). .

FIG. 1 is a perspective view showing a liquid crystal projector according to an embodiment of the present invention.
As shown in FIG. 1, the liquid crystal projector includes a projector main body 1 capable of switching between display of 2D video and 3D video, and shutter glasses 2 used by a user when displaying 3D video. The image enlarged and projected from 1 is displayed on the screen S.

FIG. 2 is a diagram showing a configuration of the projector main body 1 included in the liquid crystal projector shown in FIG.
The projector body 1 is a configuration example of a so-called three-plate type liquid crystal projector including three sets of liquid crystal light valves (liquid crystal panels) for red light modulation, green light modulation, and blue light modulation.

  Specifically, as shown in FIG. 2, the projector body 1 includes a light source 3, dichroic mirrors 4, 5, reflection mirrors 6, 7, 8, an incident lens 9, a relay lens 10, and an exit lens 11. And liquid crystal light valves 12R, 12G, and 12B, a cross dichroic prism 13, and a projection lens 14.

  In addition, an integrator optical system for making the illuminance distribution of the light emitted from the light source 3 uniform, and the polarization state of the light emitted from the light source 3 as the polarization used in the liquid crystal light valves 12R, 12G, and 12B. You may provide the polarization conversion optical system etc. which align.

  The light source 3 includes a discharge lamp 16 such as an extra-high pressure mercury lamp or a metal halide lamp, and a reflector 17 that reflects light from the discharge lamp 16. The dichroic mirror 4 has a function of transmitting the red light LR included in the white light from the light source 3 and reflecting the blue light LB and the green light LG. The dichroic mirror 5 has a function of transmitting the blue light LB and reflecting the green light LG. Therefore, the red light transmitted through the dichroic mirror 4 is reflected by the reflection mirror 6 and is incident on the red light liquid crystal light valve 12R. The green light LG reflected by the dichroic mirror 4 is reflected by the dichroic mirror 5 and enters the green light liquid crystal light valve 12G.

  Further, the blue light reflected by the dichroic mirror 4 passes through the dichroic mirror 5. For blue light, a light guide optical system 18 including a relay lens system including an incident lens 9, a relay lens 10, and an exit lens 11 is provided in order to prevent light loss due to a long optical path. Blue light is incident on the blue light liquid crystal light valve 12B via the light guide optical system 18.

  The three color lights modulated by the liquid crystal light valves 12R, 12G, and 12B are incident on the cross dichroic prism 13. The cross dichroic prism 13 is formed by bonding four right-angle prisms. A dielectric multilayer film reflecting red light and a dielectric multilayer film reflecting blue light are formed in an X shape at the interface. Yes. These dielectric multilayer films combine the three color lights to form light representing a color image. The synthesized light is projected onto a screen 19 (screen S shown in FIG. 1) by a projection lens 14 which is a projection optical system, and an image is enlarged and displayed.

  The liquid crystal projector according to the present embodiment displays 2D video and 3D video in a switchable manner. When displaying 2D video, an image corresponding to the 2D video is displayed on the screen 19. On the other hand, when displaying a 3D video, a right-eye image and a left-eye image corresponding to the 3D video are displayed on the screen 19 while being alternately switched in a time division manner for each frame. At this time, the user can visually recognize the stereoscopic image by wearing the shutter glasses 2 that open and close the right eye and the left eye alternately in synchronization with the switching between the right eye image and the left eye image. It has become.

FIG. 3 is a diagram showing a circuit configuration of the liquid crystal projector shown in FIG.
As shown in FIG. 3, the liquid crystal projector of the present embodiment includes a circuit unit 25 including an image information determination unit 21, a DC power supply unit 22, a discharge lamp lighting unit 23, an image processing unit 24, and the like inside the projector main body 1. Is roughly provided.

  The image information determination unit 21 includes an image signal conversion unit 28 and a CPU 29 (Central Processing Unit). The image information determination unit 21 determines whether the image information to be projected is stereoscopic image information for switching between a right eye image and a left eye image at a predetermined switching timing and outputting them alternately. is there.

  When an image signal (luminance-color difference signal, analog signal, etc.) SG1 is input from the outside, the image signal conversion unit 28 converts the image signal SG1 into a digital RGB signal having a predetermined word length and converts the image signals SG2R, SG2G. , SG2B is generated. At this time, the image signal conversion unit 28 receives the right-eye image and the left-eye image as the image signal SG1 when stereoscopic image information in which the right-eye image and the left-eye image are alternately switched at a predetermined timing is input. The synchronization signal SG3 is supplied to the CPU 29 on the basis of the switching timing.

  Based on the synchronization signal SG3, the CPU 29 determines whether the image information to be projected is stereoscopic image information that is output by alternately switching between the right eye image and the left eye image. A determination result SG4 as to whether or not the image information is stereoscopic image information is output to the image processing unit 24.

  Further, the CPU 29 controls the operation from the start of lighting of the liquid crystal projector 1 to the extinction thereof. Specifically, the CPU 29 outputs a lighting command and a lighting command to the discharge lamp lighting unit 23 via the communication signal SG5. Further, the CPU 29 receives lighting information of the discharge lamp 16 from the discharge lamp lighting unit 23 via the communication signal SG6. Further, based on the synchronization signal SG3, the CPU 29 outputs a control signal SG7 for controlling the shutter glasses 2 in synchronization with the image signal SG1 to the shutter glasses 2 via wired or wireless communication means.

  The image processing unit 24 performs image processing including gamma correction on the three image signals SG2R, SG2G, and SG2B. After the image processing, the image processing unit 24 generates drive signals SG8R, SG8G, and SG8B for driving the liquid crystal light valves 12R, 12G, and 12B, respectively. 12G and 12B are supplied. The liquid crystal light valves 12R, 12G, and 12B modulate the luminance of the color light incident on the liquid crystal light valves 12R, 12G, and 12B based on the drive signals SG8R, SG8G, and SG8B.

  The DC power supply unit 22 converts an AC voltage supplied from an external AC power supply 30 into a constant DC voltage, and an image signal conversion unit on the secondary side of a transformer (not shown, but included in the DC power supply unit 22). 28, a DC voltage is supplied to the image processing unit 24, the CPU 29, and the discharge lamp lighting unit 23 on the primary side of the transformer.

  The discharge lamp lighting unit 23 generates a high voltage between the pair of electrodes of the discharge lamp 16 when the liquid crystal projector 1 is started up, and causes a dielectric breakdown to form a discharge path. Thereafter, the discharge lamp 16 maintains a discharge. Drive current I1 is supplied.

  As shown in FIG. 3, the shutter glasses 2 include a right eye shutter 32R and a left eye shutter 32L. The opening and closing of the right eye shutter 32R and the left eye shutter 32L are controlled based on the control signal SG7. Note that the right-eye shutter 32R and the left-eye shutter 32L can be configured by, for example, liquid crystal shutters.

FIG. 4 is a timing chart showing the opening / closing operation of the shutter glasses 2.
As shown in FIG. 4, the shutter glasses 2 display the right eye image R in synchronization with the stereoscopic image information output by alternately switching the right eye image R and the left eye image L in a time-division manner for each frame. In the section where the right eye shutter 32R is opened and the left eye shutter 32L is shut off, and in the section where the left eye image L is displayed, the right eye shutter 32R is shut off and the left eye shutter 32L is opened.

  In the timing chart shown in FIG. 4, video signals (drive signals SG8R, SG8G,...) Corresponding to the right eye image R and the right eye image L are time-divided (1/240 seconds) every frame (1/60 seconds). SG8B) is output to the liquid crystal light valves 12R, 12G, and 12B twice each. After the video signal corresponding to the first right eye image R is output, the right eye shutter 32R is opened, and the right eye shutter 32R is shut off before the video signal corresponding to the first left eye image L is output. In this way, the timing for opening and closing the right eye shutter 32R is controlled. The timing for opening and closing the left eye shutter 32L is also controlled at the same timing.

  By the way, when the video signal writing described above is a line-sequential method, a writing delay occurs between the first line and the last line of the pixel matrix. So-called crosstalk occurs in which the left-eye image is mixed.

  The response speed of the liquid crystal necessary for preventing the occurrence of crosstalk depends on the response of the shutter glasses 2 and the setting of the opening / closing time. That is, when displaying 3D video, by setting the response speed of the liquid crystal to 2 ms or less, sufficient brightness can be obtained while suppressing the occurrence of crosstalk.

  On the other hand, when displaying 2D video, it is not necessary to switch images at high speed within one frame, so that the response speed of the liquid crystal can be made slower than when displaying 3D video. In the present embodiment, the response speed of the liquid crystal when displaying 2D video is about 3 ms.

  Therefore, in the present invention, the temperature of the liquid crystal light valves 12R, 12G, and 12B (hereinafter collectively referred to as the liquid crystal panel 12) is set higher when displaying 3D video than when displaying 2D video. Then, control was performed so that the response speed of the liquid crystal was 2 ms or less.

  In this case, when the 3D video is displayed, the right eye image and the left eye image can be switched and displayed at high speed. In addition, since the temperature of the liquid crystal panel 12 is set to be high only when displaying 3D video, the decrease in the reliability of the liquid crystal panel 12 is suppressed as compared with the case where the temperature of the liquid crystal panel 12 is always set to be high. Is possible.

  As a method for controlling the temperature of the liquid crystal panel 12, for example, as shown in FIG. 3, the CPU 29 controls the cooling fan (cooling mechanism) 40 provided inside the projector body 1, so that the temperature of the liquid crystal panel 12 is controlled. Can be controlled.

  Specifically, the CPU 29 controls the cooling fan 40 when the liquid crystal panel 12 displays 3D video based on the determination result SG4 on whether or not the above-described image information is stereoscopic image information. A signal SG9 is generated and output to the cooling fan 40. This control signal SG9 sets the drive voltage of the cooling fan 40 to be lower than when displaying 2D video, and controls the air flow of the cooling fan 40 to be lower. Thereby, the temperature of the liquid crystal panel 12 can be set high. On the other hand, when the liquid crystal panel 12 displays 2D video, the control signal SG9 sets the driving voltage of the cooling fan 40 higher than when displaying 3D video, and controls the air blowing of the cooling fan 40 to be higher. Thereby, the temperature of the liquid crystal panel 12 can be set low.

  For example, as summarized in Table 1, the driving voltage of the cooling fan 40 when displaying 2D video is set to high (Hi), so the temperature of the liquid crystal panel 12 is about 45 ° C., and the liquid crystal in this case The response speed was about 3 ms. On the other hand, since the driving voltage of the cooling fan 40 when displaying 3D video is set to a low level, the temperature of the liquid crystal panel 12 is about 55 ° C., and the response speed of the liquid crystal in this case is about 2 ms. It became.

  As a method for controlling the temperature of the liquid crystal panel 12, for example, as shown in FIG. 5, a heater (heating mechanism) 41 for heating the liquid crystal panel 12 is provided, and the CPU 29 controls the heater 41. The temperature of the liquid crystal panel 12 can also be controlled.

  Specifically, as shown in FIG. 5, the liquid crystal panel 12 has a structure in which a liquid crystal layer 44 is sandwiched between an element substrate 42 and a counter substrate 43, and a heater 41 and cooling fins 45 are provided on the element substrate 42 side. The outer peripheral portion is held by the frame 47 with the dust-proof glass 46 attached to the counter substrate 43 side.

  The CPU 29 generates a control signal SG9 for controlling the heater 41 when the liquid crystal panel 12 displays a 3D video, based on the determination result SG4 whether or not the above-described image information is stereoscopic image information. To the heater 41. As a result, the heater 41 heats the liquid crystal panel 12 so that the temperature of the liquid crystal panel 12 can be set higher.

  As described above, in the liquid crystal projector, when the 3D image is displayed, the temperature of the liquid crystal panel 12 can be set higher to increase the response speed of the liquid crystal. Can be switched at high speed. Further, in the above liquid crystal projector, the temperature of the liquid crystal panel 12 is set high only when displaying a 3D image, so that the reliability of the liquid crystal panel 12 is higher than when the temperature of the liquid crystal panel 12 is always set high. Can be suppressed.

  The liquid crystal projector may be provided with a temperature sensor (not shown) that measures the temperature of the liquid crystal panel 12. In this case, the CPU 29 can accurately control the temperature of the liquid crystal panel 12 based on the result measured by the temperature sensor.

In addition, this invention is not necessarily limited to the thing of the said embodiment, A various change can be added in the range which does not deviate from the meaning of this invention.
For example, in the above liquid crystal projector, the time division method using the shutter glasses 2 has been described as an example of the 3D video display method. However, other than that, for example, the polarization method using the polarizing glasses and the wavelength division using the spectroscopic glasses. A method etc. can be used.

  In the above-described embodiment, a liquid crystal projector has been described as an example of a projection type electro-optical device that projects an image using a liquid crystal panel as a light valve. However, direct viewing for viewing and observing the liquid crystal panel as an image display surface is described. The present invention may be applied to a type of electro-optical device. In addition, the specific configuration of the liquid crystal panel of the electro-optical device and its circuit unit is not limited to the above embodiment, and can be changed as appropriate.

  DESCRIPTION OF SYMBOLS 1 ... Projector body 2 ... Shutter glasses 12 (12R, 12G, 12B) ... Liquid crystal light valve (liquid crystal panel) 29 ... CPU (control part) 40 ... Cooling fan (cooling mechanism) 41 ... Heater (heating mechanism)

Claims (7)

A liquid crystal panel for switching between an image corresponding to a flat image and an image corresponding to a stereoscopic image;
An electro-optical device comprising: a control unit that controls the temperature of the liquid crystal panel to be higher when displaying an image corresponding to the stereoscopic video than when displaying an image corresponding to the planar video. A cooling mechanism for cooling the liquid crystal panel;
The control unit controls the driving of the cooling mechanism so that the temperature of the liquid crystal panel is higher when displaying the image corresponding to the stereoscopic image than when displaying the image corresponding to the planar image. The electro-optical device according to claim 1, wherein the electro-optical device is controlled to be A heating mechanism for heating the liquid crystal panel;
The controller controls the driving of the heating mechanism so that the temperature of the liquid crystal panel is higher when displaying the image corresponding to the stereoscopic image than when displaying the image corresponding to the planar image. The electro-optical device according to claim 1, wherein the electro-optical device is controlled to be   The right eye side is opened and the left eye side is opened in a section in which the right eye image is displayed in synchronization with the liquid crystal panel that alternately displays the right eye image and the left eye image corresponding to the stereoscopic video in time division. An electro-optical device comprising: glasses that block and block the right eye side and open the left eye side in a section in which the left eye image is displayed. A temperature sensor for measuring the temperature of the liquid crystal panel;
The electro-optical device, wherein the control unit controls the temperature of the liquid crystal panel based on a result measured by the temperature sensor.   The electro-optical device according to claim 1, wherein an image is projected using the liquid crystal panel as a light valve.   The electro-optical device according to claim 1, wherein the liquid crystal panel is directly viewed as an image display surface.

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