JP3980587B2 - Projection type display device - Google Patents

Description

  The invention disclosed in the present specification relates to a configuration capable of displaying an image that is specifically visible only to an observer on a screen. For example, the present invention relates to a configuration that can be used when transmitting image information only to a specific person in a public facility or the like.

  A display device represented by a liquid crystal display device is known. In such a display device, it is common for a plurality of observers to view the displayed display at the same time.

  However, when displaying an image for business use in a public facility or displaying an image for education, there are cases where it is desired to selectively transmit specific information only to a specific observer. For such purposes, conventional display devices cannot be used.

  An object of the invention disclosed in this specification is to provide a configuration in which a plurality of displays can be simultaneously performed on the same screen and viewed individually by a plurality of different observers.

One of the inventions disclosed in this specification is:
A liquid crystal panel in which a plurality of active matrix regions and peripheral circuits for commonly controlling horizontal scanning control and / or vertical scanning control of the plurality of active matrix regions are formed on the same substrate;
Means for providing a first polarization state to at least one of the images formed in the plurality of active matrix regions;
Means for providing a second polarization state to an image other than the image provided with the first polarization state;
Means for projecting an image formed in each active matrix region of the liquid crystal panel on a projection surface,
Have
At least one of the images formed in the plurality of active matrix regions is entirely white.

Other aspects of the invention are:
A liquid crystal panel in which a plurality of active matrix regions and peripheral circuits for commonly controlling horizontal scanning control and / or vertical scanning control of the plurality of active matrix regions are formed on the same substrate;
Means for providing a first polarization state to at least one of the images formed in the plurality of active matrix regions;
Means for providing a second polarization state to an image other than the image provided with the first polarization state;
Means for projecting an image formed in each active matrix region of the liquid crystal panel on a projection surface,
Have
At least one of the images formed in the plurality of active matrix regions is displayed in white corresponding to a region to be concealed in another image.

  The invention disclosed in this specification is characterized in that, in the above structure, the first polarization state and the second polarization state are circularly polarized light having different turning directions. The first polarization state and the second polarization state are linearly polarized light whose polarization directions are different by 90 °.

  By utilizing the invention disclosed in this specification, a display device that can give predetermined image information only to a specific person can be realized. This display device is very useful as a display device that can be viewed by an unspecified number of people because a white display screen is displayed, especially for those who do not need to provide predetermined image information. Can be.

  Further, in the display device having the significance as described above, by forming an image using an integrated liquid crystal panel, the entire display device can be made compact and the productivity thereof can be increased. Can do. Moreover, the reliability can be made high.

[Example 1]
FIG. 1 shows an outline of an integrated liquid crystal panel used in this embodiment. The configuration shown in FIG. 1 includes active matrix regions 101, 102, 103, and 104 on the same glass substrate, a horizontal scanning control circuit 105 that performs horizontal scanning control of the plurality of active matrix regions in common, and an active matrix region 101. Vertical scanning control circuit 106 that performs vertical scanning control of the active matrix region 102, vertical scanning control circuit 107 that performs vertical scanning control of the active matrix region 102, vertical scanning control circuit 108 that performs vertical scanning control of the active matrix region 103, and vertical of the active matrix region 104 A vertical scanning control circuit 109 that performs scanning control is provided.

  These active matrix regions and horizontal and vertical scanning control circuits are integrated on a single glass substrate (or quartz substrate) using thin film transistors. As the thin film transistor, it is preferable to use a thin film transistor formed using a crystalline silicon film.

  The integrated formation of the active matrix region and its drive circuit (peripheral circuit) on the same substrate as described above is compared to the conventional method in which the peripheral circuit is constituted by an IC and placed on the substrate by TAB wiring or the like. Thus, there is a significance that the labor and cost of the production can be greatly reduced. In addition, there is a significance that the entire configuration can be made compact. In particular, as shown in FIG. 1, a configuration in which some peripheral circuits are arranged in common with respect to a plurality of active matrix regions is very useful in terms of promoting the above significance.

  In each of the active matrix regions 101 to 104, different images can be formed independently. The operation of each active matrix is simultaneously controlled by a common horizontal scanning control operation clock (referred to as CLKH) and a common vertical scanning control operation clock (referred to as CLKV).

  In the integrated liquid crystal panel shown in FIG. 1, RGB color images are formed in the active matrix regions 101 to 103. Then, white display is performed on the entire surface of the active matrix area 104.

  Then, as will be described later, the RGB color image and the W white image are projected on one screen.

  FIG. 2 shows an outline of a projection type display device 200 using the integrated liquid crystal panel shown in FIG. In FIG. 2, white light from the light source 201 is reflected by mirrors 202 and 203 and enters the active matrix region 104 of the integrated liquid crystal panel shown in FIG. 1 as W (white) light.

  The active matrix region 104 is not necessary when the entire white display is performed. However, when a part of the image formed by the active matrix regions 101 to 103 is hidden, the active matrix region 104 selectively displays white. It is necessary to form.

  On the other hand, the white light emitted from the light source 212 is reflected by the mirror 213, further the light having the B (blue) wavelength region is dispersed by the dichroic mirror 206, and further the G (green) wavelength region is separated by the dichroic mirror 205. The dichroic mirror 204 splits the light having the R (red) wavelength region.

  Each light is incident on the integrated liquid crystal panel 207 shown in FIG. 1, where it undergoes predetermined optical modulation. The liquid crystal panel is supplied with necessary signals from the control circuit 211. Each image formed by optical modulation by the liquid crystal panel 207 is given a predetermined polarization state by the optical system 208.

  The optical system 208 is provided with polarization imparting means for imparting clockwise circularly polarized light to the RGB image. The means for imparting circularly polarized light includes a polarizing plate and a quarter-wave plate, or a polarizing plate, a π cell, and a quarter-wave plate.

  On the other hand, for the W image, polarization imparting means for imparting counterclockwise circularly polarized light is disposed inside the optical system 208.

  The RGBW image is projected on the screen 210 so as to overlap with the projection lens built in the optical system 208.

  FIG. 3 shows an operation timing chart when an image is displayed on the projection type display device shown in FIG. As shown in FIG. 3, the RGB images formed by the active matrix regions 101 to 103 shown in FIG. 1 are given clockwise circularly polarized light in the optical system 208 and projected onto the screen 210 as an image A. .

  On the other hand, the entire white image formed in the active matrix region 104 is provided with the counterclockwise circularly polarized light by the optical system 208 and is projected onto the screen 210 so as to overlap the previous RGB image.

  When this screen is viewed normally, the entire screen is masked by a white display and the screen only appears white. However, when the screen 210 is viewed through an optical filter that selectively transmits right-handed circularly polarized light, the entire white image of left-handed circularly polarized light is almost blocked, and only the A image is selectively visible. .

  For example, when the screen 210 is viewed using special glasses equipped with an optical filter that selectively transmits clockwise circularly polarized light, the color image A can be viewed.

  In other words, for an unspecified number of people who can normally see the screen, the color image A is shown only to those wearing spectacles equipped with a specific optical filter by simply showing a white display on the entire screen. Can do.

  Here, a configuration is shown in which the entire image A is concealed with a white image. However, the white image may be selective so as to conceal part of the image A. Alternatively, a concealment screen having the highest concealment effect obtained in a case may be used instead of white.

  Such a configuration can be used, for example, in an airfield, a train station, a shopping center, or the like, when displaying on a screen that can be viewed by an unspecified number of people only for those concerned. . In this case, a person concerned may look at the screen 210 with special glasses that transmit a specific polarization state.

  For reference, the operation method of the liquid crystal panel shown in FIG. 1 will be briefly described below. Here, in order to simplify the description, the operation in the active matrix region 101 will be described. Note that the same operation is performed at the same timing in other active matrix regions.

In FIG. 1, reference numerals 110 to 112 denote flip-flop circuits. The flip-flop circuit is a circuit that can take two stable states. For example, it is assumed that the input (point of X ₀ ) of the flip-flop circuit 111 is in the H state (high at logic level) and the output (point of X ₁ ) is in the state of L (low at logic level). Here, when the rising edge of CLKH (the operation clock of the horizontal scanning control circuit) is input, the output changes to the H level. That is, the point X ₁ is at the H level. This state is maintained as long as the next rising edge of CLKH is not input.

  For example, assume that the input of the flip-flop circuit 111 is in the L state and the output is in the H state. Here, when the rising edge of CLKH is input, the output changes to the L level.

  Further, it is assumed that the input of the flip-flop circuit 111 is in the L state and the output is in the L state. When the rising edge of CLKH is input here, the output is maintained at the L level.

  First, the rising edge of CLKV (operation clock of the vertical scanning control circuit) is input to the flip-flop circuit 112 of the vertical scanning control circuit 106. Here, HSTA (horizontal scanning timing enable signal) is punched out by CLKV.

That is, when the HSTA signal at the H level is applied to the input of the flip-flop circuit 112, the rising edge of CLKV is input to the flip-flop circuit 112, so that the output of the flip-flop circuit 112 becomes H level. As a result, the signal level of the Y ₀ row becomes the H state.

When the signal level of the Y ₀ row is in the H state, all the thin film transistors of the pixels indicated by the addresses (0,0), (1,0),... (M, 0) are turned on.

In this state, the rising edge of CLKH (operation clock of the horizontal scanning control circuit) is input to the flip-flop circuit 110, and CLKH (horizontal scanning timing enable signal) is punched out. As a result, the signal level at X ₀ becomes H.

  At the stage when the above CLKH is input, all the inputs of the flip-flop circuits after 111 are at the L level, and in this state, the outputs of the flip-flop circuits after 111 are all at the L level.

  Then, the image sampling signal line 116 becomes H level. As a result, the image data of the B image is captured by the sampling hold circuit 114. A signal corresponding to predetermined image data flows through the image signal line 117. That is, a predetermined image signal is applied to the source of the thin film transistor of each pixel indicated by the addresses (0,0), (0,1),... (0, n).

  In this state, the thin film transistors of the respective pixels indicated by the addresses (0, 0), (1,0),... (M, 0) are all turned on. Therefore, image information is written only to the pixel at address (0,0).

Next, the output of the flip-flop circuit 110 changes to the L level by the next rising edge of CLKH. Further, the output of the flip-flop circuit 111 changes to the H level. Thus, the point X ₁ becomes the H level. All points indicated by X _m other than X ₁ in this state is L level.

  As a result, predetermined image data is taken in by the sampling and holding circuit 115, and information is written to address (1,0).

  In this way, the writing of information up to the address (m, 0) is sequentially performed according to the clock signal of CLKH.

When the writing of information to the Y ₀ row is completed, the output of the flip-flop circuit 112 becomes L level and the output of the flip-flop circuit 113 becomes H level by the next rising pulse of CLKV.

Thus, writing of information to Y ₁ line is carried out. In this manner, information is sequentially written to each pixel, and one frame display is finished when the writing of information to the address (m, n) is finished. This frame is repeated, for example, 30 times per second. In this way, an image is displayed.

[Example 2]
The present embodiment is characterized in that the configuration shown in FIG. 4 is adopted as the integrated liquid crystal panel in the configuration shown in the first embodiment. The configuration shown in FIG. 4 is a further extension of the configuration shown in FIG. 1, and can form two color images of RGB, and can also form two white images for concealment. .

  In the configuration shown in FIG. 4, horizontal scanning of the active matrix regions 401, 402, 403, and 404 is commonly controlled by the horizontal scanning control circuit 409. The horizontal scanning control circuit 410 controls the horizontal scanning of the active matrix regions 405, 406, 407, and 408 in common.

  Further, the vertical scanning control circuit 411 controls the vertical scanning of the active matrix regions 401 and 405 in common. The vertical scanning control circuit 412 controls the vertical scanning of the active matrix regions 402 and 406 in common. Further, the vertical scanning control circuit 413 controls the vertical scanning of the active matrix regions 403 and 407 in common. Further, the vertical scanning control circuit 414 controls the vertical scanning of the active matrix regions 404 and 408 in common.

  Such a configuration can be used to form a screen with higher luminance or a stereoscopic screen. In addition, since the horizontal and / or vertical scanning control circuit is shared by a plurality of active matrix regions, it is possible to obtain significance such as downsizing, improvement in productivity, and improvement in reliability.

Example 3
This embodiment is an example in which the same monochrome image is formed in the active matrix regions 101 to 103 in the configuration shown in the first embodiment. In such a configuration, although it is a monochrome image, since three identical images are superimposed, an image with extremely high luminance can be obtained. In this embodiment, in order to obtain a high luminance, it is necessary to use a half mirror without using the dichroic mirrors 204 to 206 in the apparatus configuration shown in FIG. Further, a light source may be arranged corresponding to each active matrix region of the liquid crystal panel 207.

Example 4
The present embodiment is an example in which a simple polarizing plate is used as a means for imparting a specific polarization state in the configuration shown in the first embodiment. In this case, linearly polarized light having a specific polarization direction and linearly polarized light having a polarization direction different from that by 90 ° may be selected. Such a configuration can simplify the configuration of the means for providing a specific polarization state and the optical filter that selectively transmits the specific polarization state.

The figure which shows the outline | summary of the integrated liquid crystal panel. FIG. 2 is a diagram showing an outline of a projection display device using the liquid crystal panel shown in FIG. 1. The figure which shows the operation | movement timing chart at the time of displaying an image. The figure which shows the outline | summary of the integrated liquid crystal panel.

Explanation of symbols

101, 102, 103, 104 Active matrix region 105 Horizontal scanning control circuit 106, 107, 108, 109 Vertical scanning control circuit 110, 111, 112 Flip-flop circuit 200 Device housing 201 Light source 202, 203 Mirror 204, 205, 206 Dichroic mirror 207 Integrated liquid crystal panel 208 Optical system 209 Mirror 210 Screen 211 Control circuit 212 Light source 213 Mirror

Claims (8)

Means for providing a first polarization state for at least one of the plurality of images;
Means for providing a second polarization state to an image other than the image provided with the first polarization state;
Means for projecting the first image provided with the first polarization state and the second image provided with the second polarization state on a projection surface in an overlapping manner;
Have
The first image is a monochrome image or a color image;
The projection-type display device, wherein the second image is a white display that hides the entire surface of the first image.   The projection display device according to claim 1, wherein the first polarization state and the second polarization state are circularly polarized light having different turning directions.   2. The projection type display device according to claim 1, wherein the first polarization state and the second polarization state are linearly polarized light whose turning directions are different from each other by 90 degrees.   3. The means for providing the first and second polarization states according to claim 1 or 2, comprising a polarizing plate and a quarter wavelength plate, or a polarizing plate, a π cell, and a quarter wavelength plate. A projection-type display device.   5. The substrate according to claim 1, wherein a plurality of active matrix regions that form the plurality of images and a peripheral circuit that performs horizontal scanning control and vertical scanning control of the plurality of active matrix regions are formed on the same substrate. A projection-type display device formed on the top.   6. The peripheral circuit according to claim 5, wherein the peripheral circuit controls at least one of horizontal scanning control and vertical scanning control of the plurality of active matrix regions in common to the plurality of active matrix regions. A projection-type display device characterized.   7. The method according to claim 1, wherein only the first image is viewed by viewing the projection plane through an optical filter that selectively transmits the first polarization state. A projection-type display device. 8. The method according to claim 1, wherein the first image and the second image are projected on one of the projection surfaces, and the other of the projection surfaces is shown to an observer. A projection-type display device.

Images