JP2007139865A - Three-dimensional image display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a three-dimensional image display device which is capable of obtaining a three-dimensional image of high quality by suppressing moire due to interference between grid patterns of a black matrixes or the like of a rear-side liquid crystal display LCD panel and a front-side LCD panel which are put one over the other. <P>SOLUTION: A display controller DSC computes and distributes display data R, G, and B to be given to a front-side LCD panel PNL1 and a rear-side LCD panel PNL2 respectively, on the basis of display data R, G, and B inputted from an external signal source SOC and depth information Z. Definition of display data to the rear-side LCD panel PNL2 of high definition is converted by a definition conversion circuit CC2 (scaler). The definition conversion circuit CC2 converts a display signal to the rear-side LCD panel PNL2 from VGA to XGA. Thus moire due to interference between grid patterns of black matrixes or the like of two LCD panels to obtain a three-dimensional image of high quality. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a display device, and more particularly to a three-dimensional image display device that displays a stereoscopically visible image by superimposing images displayed on two liquid crystal display panels arranged in front and rear.

  Patent Document 1 can be cited as a technique for displaying a three-dimensional stereoscopic image on a display screen without using special glasses or the like. In Patent Literature 1, a two-dimensional image is generated by projecting a display target object from a viewing direction of the observer on a plurality of display surfaces at different depth positions as viewed from the observer. The generated two-dimensional image is displayed on each of a plurality of display surfaces at different depth positions as viewed from the observer, and the brightness of the displayed two-dimensional image is independently changed for each display surface, and the third order An original stereoscopic image is generated.

  And in patent document 1, in this three-dimensional display method, the transparency of the two-dimensional image displayed on each display surface is changed independently for each display surface, and the two-dimensional displayed on each display surface. It describes that the brightness of an image is changed independently.

Various liquid crystal display devices that perform three-dimensional image display using a liquid crystal display panel have been proposed. For example, two liquid crystal display panels are separated from each other at a predetermined interval and overlapped, and the image data supplied to the front liquid crystal display panel and the rear liquid crystal display panel has a difference in parallax or movement. In Japanese Patent Application Laid-Open No. H11-228707, a technique for realizing three-dimensional image display is disclosed. In Patent Document 2, the movement of background data displayed on the rear liquid crystal display panel is smaller than the foreground data displayed on the front liquid crystal display panel, so that a three-dimensional image is displayed. It should be noted that the arrangement of the front liquid crystal display panel and the rear liquid crystal display panel or the difference between the movements of the background data and the foreground data or both are depth information for observation as a three-dimensional display.
Japanese Patent Laid-Open No. 2001-54144 Japanese Patent No. 3335998

  Currently, the liquid crystal display panel which has become mainstream is a color liquid crystal display panel having three color filters. In this color liquid crystal display panel, the contrast between the colors constituting the color filter is improved by partitioning with a lattice-shaped light shielding film (black matrix). Here, such a color liquid crystal display panel is simply referred to as a liquid crystal display panel.

  Since the black matrix is a pattern formed by a light-shielding grid and has periodicity, when two liquid crystal display panels are overlapped on the front and back and an image is displayed on both, the black matrix between the grid patterns of each other black matrix Moire occurs due to interference.

  Such moire is generally defined as an optical interference fringe generated when the arrangement of two black matrix lattice patterns is approximate. When the lattice patterns of the black matrixes of the two liquid crystal display panels are overlapped in parallel with each other, the moire caused by the interference between the two lattice patterns becomes a lattice shape having a density and pitch different from those of the original lattice. In addition, when the lattices are overlapped with an angle, the moire appears as a curve with shades that are drawn indefinitely in multiple layers. Since the liquid crystal display panel also has an electrode lattice pattern in which drain lines and gate lines intersect at right angles, the electrode lattice pattern of two superimposed liquid crystal display panels is provided. Similar moiré is generated by interference between the lattice pattern of one electrode or the other and the other black matrix pattern.

  Patent Documents 1 and 2 do not consider such moiré countermeasures for the two stacked liquid crystal display panels.

  An object of the present invention is to suppress moire due to interference between lattice patterns such as black matrixes and electrodes included in the superimposed front and rear liquid crystal display panels and to obtain a high-quality three-dimensional image. The object is to provide a three-dimensional image display device.

  The display device of the present invention converts two liquid crystal display panels superimposed at a predetermined interval in front and back, and display data input from the outside into display signals to be displayed on the display units of the two liquid crystal display devices, respectively. A two-dimensional image displayed on the display unit of the front liquid crystal display panel of the two liquid crystal display panels and a two-dimensional image displayed on the display unit of the rear liquid crystal display panel Is a three-dimensional image display device that generates a three-dimensional image by superimposing and.

  The present invention is characterized in that the definition of the image displayed on the display unit of the front liquid crystal display panel is different from the definition of the image displayed on the display unit of the rear liquid crystal display panel. .

  Further, the present invention is characterized in that a pixel pitch of the front side liquid crystal display panel is different from a pixel pitch of the rear side liquid crystal display panel. The pixel pitch is also referred to as a black matrix that partitions adjacent pixels, or the pitch between the scanning line electrode and the data line electrode. The pixel pitch in the present invention means the same as the pitch of the black matrix lattice pattern or the pitch of the scanning line electrode and the data line electrode panel.

  Further, the invention is characterized in that a pixel pitch of the front liquid crystal display panel is smaller than a pixel pitch of the rear liquid crystal display panel.

  Further, the invention is characterized in that the pixel pitch of the front liquid crystal display panel is larger than the pixel pitch of the rear liquid crystal display panel.

  Further, the present invention is characterized in that the display control device has a definition conversion circuit and supplies the display unit of the front liquid crystal display panel and the display unit of the rear liquid crystal display panel as display signals having different definition. And

  Further, the present invention is characterized in that the definition of the display signal supplied to the front liquid crystal display panel is higher than the definition of the display signal supplied to the rear liquid crystal display panel.

  Further, the present invention is characterized in that the definition of the display signal supplied to the front liquid crystal display panel is lower than the definition of the display signal supplied to the rear liquid crystal display panel.

Further, according to the present invention, the display data input from the outside is composed of each gradation signal of red, green, and blue and depth information,
In the display control device, display signals of three colors of red, green, and blue for displaying on the display unit of the front liquid crystal display panel from the gradation signals and depth information of the three colors, and the rear liquid crystal display panel A two-screen display signal generation circuit that develops red, green, and blue three-color display signals for display on the display unit;
A definition conversion circuit that converts the resolution of display signals of three colors red, green, and blue for display on the display unit of the rear liquid crystal display panel;
A display unit of the front liquid crystal display panel and a timing controller for generating display timing of the display unit of the rear liquid crystal display panel are provided.

  Further, the present invention is characterized in that the definition of the front liquid crystal display panel is the same as the definition of the display data input from the outside.

  Further, the present invention is characterized in that the definition of the rear liquid crystal display panel is the same as the definition of display data input from the outside.

  According to the present invention, the black matrix lattice pattern (hereinafter also referred to as a black matrix pattern) of each liquid crystal display panel, or electrodes can be obtained by differentiating the definition of images displayed on the liquid crystal display panels arranged on the front and back sides. Generation of interference fringes (moire) between patterns is suppressed.

  In addition, according to the present invention, by using two liquid crystal display panels having different resolutions in front and back, for example, when a display device of an in-vehicle navigation system is used, the rear liquid crystal display panel has a small pixel pitch (fine ) Display detailed map information on the display unit, and use a front liquid crystal display panel with a larger (rougher) pixel pitch than the rear panel, and display the menu screen, current position information, etc. It can be used to display information with a relatively coarse pixel pitch. Needless to say, the definition of the front liquid crystal display panel and the rear liquid crystal display panel can be reversed.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings of the examples. In an embodiment of the present invention, an image display device capable of showing a stereoscopic display to an observer with a structure in which two liquid crystal display panels are stacked will be described. Here, the front liquid crystal display panel is a 9-type VGA (horizontal 640 pixels × vertical 480 pixels, hereinafter referred to as 640 × 480 pixels), and the rear-side liquid crystal display panel PNL2 is a 9-type XGA (1024 × 768 pixels). As will be described, the definition of the signal may be read in reverse for the liquid crystal display panels of the front and rear that are reversed.

  FIG. 1 is a diagram for explaining a configuration of a first embodiment of a three-dimensional image display apparatus according to the present invention using two liquid crystal panels. In FIG. 1, the three-dimensional image display device includes a front side liquid crystal display panel PNL1 and a rear side liquid crystal display panel PNL2 that are stacked at a predetermined interval. The front liquid crystal display panel PNL1 has a display unit ARF, and the rear liquid crystal display panel PNL2 has a display unit ARR.

  A display controller DSC is connected to the front liquid crystal display panel PNL1 and the rear liquid crystal display panel PNL2, and the two liquid crystal display panels and the display controller DSC constitute a display module MDL.

  Display data input from the external signal source SOC is composed of gradation signals R, G, B of three colors of red, green, and blue and depth information Z. This display data is input to the display controller DSC of the display module MDL via the interface circuit IF. In the display module MDL, display signals of three colors of red, green, and blue for display on the display portion ARF of the front liquid crystal display panel PNL1 from the three color gradation signals R, G, B and the depth information Z and the rear Displayed on the two-screen display signal generation circuit CC1 developed in two systems of red, green, and blue three-color display signals for display on the display section of the side liquid crystal display panel, and the display section ARR of the rear liquid crystal display panel PNL2. Definition conversion circuit CC2 that converts the resolution of the display signals of three colors red, green, and blue, and a TFT that converts the R, G, and B signals into signals (TFT signals) that drive the pixel circuits of the liquid crystal display panel The signal conversion circuit CC3, the display unit ARF of the front liquid crystal display panel PNL1, and the timing controller TCON that generates the display timing of the display unit ARR of the rear liquid crystal display panel PNL2.

  In the first embodiment, the display signals (gradation signals) R, G, B and the depth information Z input from the external signal source SOC are typically 6 bits each, and the display controller DSC inputs R. , G, B, and Z are used to calculate and distribute display signals R, G, B applied to the front liquid crystal display panel PNL1 and the rear liquid crystal display panel PNL2, respectively. In addition, the display data on the rear liquid crystal display panel PNL2 having a high definition is converted by the definition conversion circuit CC2 (scaler). The definition conversion is performed by, for example, a bilinear method.

  The display data input from the external signal source SOC is VGA, which is the same as that of the front liquid crystal display panel PNL1. Therefore, the definition conversion circuit CC2 converts the display signal to the rear liquid crystal display panel PNL2 from VGA to XGA.

FIG. 2 is a diagram for explaining the relationship between the pixel pitch of the liquid crystal display panel and the moire wavelength. Moire (interference fringes) is conspicuous when the ratio of the pixel pitch of two liquid crystal display panels is close to 1. Generally, when the pixel pitch of the front liquid crystal display panel PNL1 is P1, the pixel pitch of the rear liquid crystal display panel PNL2 is P2, and the moire wavelength is P,
1 / P =? 1 / P1-1 / P0?
There is a relationship.

  The horizontal axis in FIG. 2 is P1 / P0, and the vertical axis is P / P0. That is, the ratio of the pixel pitch of the two liquid crystal display panels PNL1 and PNL2 is taken on the horizontal axis, and the ratio of the moire wavelength and the pixel pitch of the rear liquid crystal display panel PNL2 is taken on the vertical axis to show the relationship between the two ratios. .

  In general, the pixel pitch of the liquid crystal display panel is 1 mm or less, for example, 0.33 mm for a VGA definition (460 × 640 pixels). If the vertical axis (P / P0) is about 5 or less, the moire pitch is as small as about 1.65 mm, and the moire is not a concern.

  When the definition of the rear liquid crystal display panel PNL2 is QVGA (240 × 320 pixels) and the definition of the front liquid crystal display panel PNL1 is VGA (460 × 640 pixels), P1 / P0 is 1/2 and P / P0 Becomes 1 and moire is not noticeable.

  When the definition of the rear liquid crystal display panel PNL2 is VGA (460 × 640 pixels) and the definition of the front liquid crystal display panel PNL1 is QVGA (240 × 320 pixels), P1 / P0 is 2/1 and P / P0 Becomes 2, and the moire is inconspicuous.

  If the definition of the rear liquid crystal display panel PNL2 is VGA (460 × 640 pixels) and the definition of the front liquid crystal display panel PNL1 is XGA (768 × 1024 pixels), P1 / P0 is 1.6 and P / P0 Becomes 2.7, and moire is inconspicuous.

  FIG. 3 is an exploded perspective view illustrating a configuration example of a three-dimensional image display device in which two liquid crystal display panels are superimposed in front and rear in the vertical direction when viewed from the observation side to perform stereoscopic image display. In this three-dimensional image display device, the front side liquid crystal display panel PNL1 and the rear side liquid crystal display panel PNL2 are overlapped at a predetermined interval via a spacer SPC. A polarizing film POL1 is attached to the surface of the front liquid crystal display panel PNL1, and a polarizing film POL2 is attached to the back surface of the rear liquid crystal display panel PNL2.

  An illuminating device (backlight) BL is installed on the rear surface of the rear liquid crystal display panel PNL2, and the lower frame FLM2 and the upper frame FLM1 constitute a casing that wraps and integrates the display device. Further, in this three-dimensional image display device, one or a plurality of cold cathode fluorescent lamps are used for the illumination device, that is, the backlight BL, and an inverter INV for supplying a drive current thereto is provided. In addition, as such a backlight, there exist other things using a light emitting diode.

  In the above-described embodiment, the liquid crystal display panel is used as a display device. However, the present invention is not limited to this, and one display image is superimposed on the other display image. The present invention can be similarly applied to those having a structure having regularity in their display areas.

It is a figure explaining the structure of Example 1 of the three-dimensional image display apparatus of this invention using two liquid crystal panels. It is a figure explaining the relationship between the pixel pitch of a liquid crystal display panel, and a moire wavelength. It is a development perspective view explaining the example of composition of the three-dimensional image display device which piled up two liquid crystal display panels in the front-and-rear direction, and performed stereoscopic image display seeing from the observation side.

Explanation of symbols

PNL1: front liquid crystal display panel, PNL2: rear liquid crystal display panel, DSC: display control device, MDL: display module, SOC: external signal source, IF: interface circuit, CC1 ... two-screen display signal generation circuit, CC2 ... definition conversion circuit, TCON ... timing controller.

Claims (10)

Two liquid crystal display panels superposed on each other at a predetermined interval, and a display control device for converting display data input from the outside into display signals to be displayed on the display units of the two liquid crystal display devices and supplying the display signals The two-dimensional image displayed on the display unit of the front liquid crystal display panel of the two liquid crystal display panels and the two-dimensional image displayed on the display unit of the rear liquid crystal display panel are superimposed to form a three-dimensional image. A three-dimensional image display device for generating an image,
3. A three-dimensional image display device, wherein the definition of an image displayed on the display unit of the front liquid crystal display panel is different from the definition of an image displayed on the display unit of the rear liquid crystal display panel. The three-dimensional image display device according to claim 1,
A three-dimensional image display device, wherein a pixel pitch of the front liquid crystal display panel and a pixel pitch of the rear liquid crystal display panel are different. The three-dimensional image display device according to claim 2,
A three-dimensional image display device, wherein a pixel pitch of a pixel pitch of the front liquid crystal display panel is smaller than a pixel pitch of the rear liquid crystal display panel. The three-dimensional image display device according to claim 2,
A three-dimensional image display device, wherein a pixel pitch of a pixel pitch of the front liquid crystal display panel is larger than a pixel pitch of the rear liquid crystal display panel. The three-dimensional image display device according to claim 1,
A three-dimensional image display characterized by having a definition conversion circuit in the display control device and supplying the display unit of the front liquid crystal display panel and the display unit of the rear liquid crystal display panel as display signals having different definition. apparatus. The three-dimensional image display device according to claim 5,
A three-dimensional image display device, wherein a definition of a display signal supplied to the front liquid crystal display panel is higher than a definition of a display signal supplied to the rear liquid crystal display panel. The three-dimensional image display device according to claim 5,
A three-dimensional image display device, wherein a definition of a display signal supplied to the front liquid crystal display panel is lower than a definition of a display signal supplied to the rear liquid crystal display panel. The three-dimensional image display device according to claim 1,
The display data input from the outside is composed of each gradation signal of red, green, and blue and depth information,
In the display control device, display signals of three colors of red, green, and blue for displaying on the display unit of the front liquid crystal display panel from the gradation signals and depth information of the three colors, and the rear liquid crystal display panel A two-screen display signal generation circuit that develops red, green, and blue three-color display signals for display on the display unit;
A definition conversion circuit that converts the resolution of display signals of three colors red, green, and blue for display on the display unit of the rear liquid crystal display panel;
A three-dimensional image display device comprising: a display unit of the front liquid crystal display panel; and a timing controller that generates display timing of the display unit of the rear liquid crystal display panel. The three-dimensional image display device according to claim 8,
3. The three-dimensional image display device according to claim 1, wherein a resolution of the front liquid crystal display panel is the same as a resolution of display data input from the outside. 3. A three-dimensional image display device, wherein the definition of the rear liquid crystal display panel is the same as the definition of display data input from the outside.

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