JPS61166524A - Liquid crystal display device - Google Patents

Abstract

PURPOSE:To express display images stereoscopically by laminating polarizing plates, where positions of polarizers are shifted from one another on a plane, in the front of a liquid crystal display element and varying distances from the surface of the liquid crystal display element to individual polarizers. CONSTITUTION:When a voltage is impressed to a liquid crystal layer, corresponding picture elements look black on the surface. Concretely, an image is displayed in the deepest position of a display surface by the polarizer of a polarizing plate 1 out of laminated polarizing plates, and the image is displayed in the front part by polarizers of polarizing plates N.M. Since upper and lower picture elements are different in height in this manner, each picture element has depth information when the image is seen on the plane. Since the density of the coloring matter of a polarizing plate 9 is made highest and the density is reduced successively toward the deepest part, picture elements look deeper gradually and the contrast of the image is reduced gradually toward the depest part when ima- ges are formed continuously from the polarizing plate 9 to the polarizing plate 1; and thus, the displayed image looks more stereoscopic feeling.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a liquid crystal display device that displays images three-dimensionally on a liquid crystal display.

[Prior Art] Several attempts have been made to display images three-dimensionally. Such items include glasses that use bolograms, glasses with different colors for the left and right sides, or P
There are methods that utilize the parallax between both eyes, such as temporal modulation using glasses made of shutters such as LZT.

[Problems to be Solved by the Invention] As described above, although there are several techniques for displaying images three-dimensionally, the former requires time and effort to record signal waves, and the latter requires time and effort in the image display device. There were drawbacks such as the need for matching glasses.

The present invention was made in order to solve the above-mentioned conventional difficulties, and by laminating a polarizing plate with the polarizer shifted in the plane behind the display element, it is easy to use other tools. The purpose of the present invention is to provide a liquid crystal display device that displays a three-dimensional image using the display device itself without using it.

[Means for solving the problem] In a typical matrix display panel, a liquid crystal material is sealed between a pixel electrode and a scanning electrode, and a voltage is applied between the upper and lower electrodes to change the alignment state of the liquid crystal layer. This is used to display images. In such a device, a large number of pixel electrodes serving as a basic unit are assembled to form a screen, and each pixel electrode is a single pixel.

In the present invention, a single pixel matrix is obtained by dividing this collection of single pixels vertically and horizontally into NXM, and each single pixel of this single pixel matrix is assigned a number from 1-N-M.
The polarizing plate placed behind the liquid crystal display element (viewing side) is also NX.
Each polarizing plate is divided into M even parts, and one polarizer corresponding to the pixels of the single pixel matrix lNM is formed on each polarizing plate.

Assign numbers la-N-Ma to each polarizer that becomes a pixel. That is, the polarizer 1a of the polarizing plate 1 corresponds to 1 of the NXM single pixel matrix, and the polarizer 2 of the polarizing plate 2 corresponds to 2 of the NXM single pixel matrix.

Similarly, the polarizer N-Ma of the polarizing plate N-M is made to correspond to N-M of the N×M single pixel matrix, so that the positions of the polarizers do not overlap in the plane for a total of N-M polarizing plates. At the same time, the concentration of the dye in each polarizer was adjusted to 1a-N.
-Ha is gradually increased so that the concentration of the polarizing plate 1 at the innermost part is low and the concentration of the polarizing plate 9 at the frontmost part is high.

[Function] When a voltage is applied to the liquid crystal layer, the corresponding pixel appears black on the surface. Specifically, among the laminated polarizing plates, the image is displayed on the innermost surface of the display surface by the polarizer of polarizing plate 1, and the image is displayed at the forefront of the polarizer of polarizing plates NM. Due to such a difference in height between the upper and lower edges, each pixel has depth information when viewed two-dimensionally.

Furthermore, as mentioned above, by increasing the dye concentration of the polarizing plate 9,
Since the density is set so that it gradually decreases as it approaches the innermost part, for example, when an image is continuously formed from polarizing plate 9 to 1, if the pixels gradually become visible to the innermost part, At the same time, the contrast of the image gradually decreases, and the displayed image becomes more stereoscopic.

[Embodiment] FIG. 2 shows a liquid crystal optical modulation section configured in a matrix. Examples of driving methods for each modulation section include TFT (thin film transistor) driving, simple matrix driving, and multiple matrix driving. These driving methods include TN (twisted nematic) liquid crystal, ferroelectric liquid crystal, and US Pat.
Chiral smectic C described in Publication No. 367924
phase, H phase, etc. are used.

FIG. 3 shows one of the 3×3 single pixel matrices separated by dashed lines in FIG. 2.

Each single pixel is assigned a number.

FIG. 4 shows the positions of the polarizers in each polarizing plate placed behind the liquid crystal display element. As is clear from the above description, the polarizer 1a is provided in the polarizing plate l laminated at the innermost part, corresponding to the single pixel number l of the single pixel matrix shown in FIG. 2 is Fig. 3 2
Polarized light 2a is provided correspondingly. Similarly, all polarizing plates up to the polarizing plate 9 disposed at the forefront are provided with polarizers corresponding to single pixel numbers. In addition, the black background part in FIG. 4 shows a polarizer, and the white background part shows the transparent part in which the polarizer is not provided.

FIG. 1 is a sectional view showing an embodiment of the liquid crystal display device of the present invention. In the figure, 1 to 9 are the polarizing plates described above, which are made by applying a mask to a stretched polymer such as polyvinyl alcohol and coating it with a dye, and are sequentially laminated behind the liquid crystal display element as shown in the figure. It was formed by
In this example, the concentration of the dye in polarizing plates 1 to 9 was made to gradually decrease from 9 to 1,
The polarizing plate 9 is formed to have a high concentration, and the polarizing plate 1 has a low concentration. In FIG. 1, 11 is ITO (I
Transparent scanning electrodes such as ndium-Tin-Oxide.

12 is a pixel electrode made of the same material such as ITO, and as mentioned above, the liquid crystal layer 13 sandwiched between these electrodes is made of TPT.
drive or other conventional matrix drive methods.

10 is a transparent substrate made of glass or the like, and 14 is a polarizing plate provided on the front surface of the element, the entire surface of which is a polarizer.

Next, the operation will be described in the case where twisted nematic liquid crystal, which is generally well known as a liquid crystal material, is used.

In FIG. 1, the → mark A indicates the transmission axis direction of each polarizer in the polarizing plates 1 to 9, and the O■ mark B indicates the back side polarizing plate 14.
The direction of the transmission axis is shown. That is, the transmission axes of the upper and lower polarizers are perpendicular to each other in a plane. In this way, when a voltage exceeding the threshold of the liquid crystal is not applied between the electrodes of the display element with the polarizers facing each other at right angles, the incident light is linearly polarized by each polarizer to the polarizers 1 to 9, and the liquid crystal layer to go into. Here, the incident light is rotated by approximately 90° along the twist of the liquid crystal molecules due to the nematic liquid crystal having positive dielectric anisotropy. Therefore, the incident light passes through the polarizing plate and then the liquid crystal layer 13 and the polarizing plate 14, so that it appears white. On the other hand, when a voltage equal to or higher than the threshold of the liquid crystal is applied between the electrodes, the liquid crystal molecules are aligned substantially perpendicular to the direction of the electric field. Therefore, the optical rotation of the light is lost, and the incident light that has passed through the polarizing plates 1 to 9 cannot be seen through the polarizing plate 14.
Polarizing plates 1 to 9 appear black. That is, by controlling the voltage between the pixel electrode and the scanning electrode corresponding to an arbitrary single pixel, a bright and dark display is performed.

When a voltage is applied to the liquid crystal layer corresponding to, for example, a single pixel 1 through the basic operation explained above, the polarizer 1a (single pixel 1) of the polarizing plate 1 appears black on the surface, and the innermost side of the display surface The image is displayed. Similarly, when a voltage is applied to the liquid crystal layer corresponding to a single pixel 9, the polarizer 9a (single pixel 9) of the polarizing plate 9 becomes black, and an image is displayed at the forefront. In this way, since each pixel is displayed at a different distance from the element surface, the displayed image has depth information. moreover,
In order to enhance the effect, we changed the dye concentration of each polarizing plate,
It emphasizes the strength and weakness of contrast. Therefore, if an image is displayed on the entire display surface, which is a collection of single pixel matrices, the displayed image can be viewed three-dimensionally.

Next, a case in which the liquid crystal display device shown in FIG. 1 is actually driven will be described.

FIG. 5 is an overall configuration diagram showing the drive circuit in this embodiment. In the figure, 101 is a microcomputer that performs overall control and input signal processing. 102 is a RAM (Random Access Memo) that can store image information for one screen.
ry; for example, static RAM in 2). 103 is R
A shift register serially sends the data in AM to the liquid crystal driver 105. 104 is a group of counters that count the operation clock generated by the clock generator 107, and the data load signal R of the shift register 103 is
AM column address 4-bit signal ・Signal that informs the CPU (microcomputer 101) of the column address count amplifier ・H8YNC (horizontal synchronization signal) of the liquid crystal driver 105
, VSYNC (vertical synchronization signal), etc. 10
5 is a driver for a liquid crystal graphic display, and by applying a serial data signal, HSYNCVSYNC, and a clock, it is possible to display, for example, 320×40 bits. ROW 106 stores the program of the microcomputer 101 and display image data.
(Read 0nly Mes+ory), 107
is shift register 103. This is a clock generator that operates the counter group 104 and the liquid crystal driver 105.

First, the microcomputer 101 transfers image information of a certain screen stored in the ROM 10B to the RAM 102.

Of course, at this time direct memory access (DM
A) A controller may be used. This image information has a pixel configuration as shown in FIG.

The image information transferred to the RAM 102 is transferred to the microcomputer 10.
The data is sent to the shift register 103 as 8 bits of data indicated by 7 bits of the row address by 1 and 4 bits of the column address by the counter 104. The 4-bit column address is incremented by 1 every 8 clocks, and 8-bit data is sent to the shift register 103 every time the 4-bit data is counted up (that is, every time 16 bytes are transferred). This causes the microcomputer 101 to set the row address to 1.
Increment and transfer the next data.

On the other hand, the data transferred to the liquid crystal driver 105 is
-The signal is read and latched by the HSYNG signal input, and sent to the display signal electrode, and the -th row is displayed. The image information on the second line of the opening method is serially sent into the register and similarly latched with the next HSYNC signal. Since the row control signal is also scanned in synchronization with this, the second row is displayed. When the display of the last row is completed by repeating this, the row control signal starts scanning again from the first row by the VSYNCi signal.

HSYNG: Signal - VSYNC signal is the counter group 10
For example, in a display element of 320 x 40 dots, the H5YNG signal is output by counting up the clock signal by 2.
The counter group 104 is configured so that the C signal is output every 40 counts of the HSYNG signal.

In this way, the image information stored in the RAM 102 can be driven and displayed in a time-division manner by the liquid crystal display element.

The RAM 102 can store information for one screen of the liquid crystal display element, so when displaying a still image, once the data is transferred to the RAM 102, the display can be continued using the above method. . Furthermore, in the case of making a moving image, if the microcomputer 101 transfers continuous image information from the ROM 10B to the RAM 102, the displayed image can be moved accordingly. In this case, the contents of the RAM 102 can be changed entirely, or only a range related to movement can be changed. Image information with height information can be easily created on a personal computer from a plan view of a three-dimensional object and its height information. It is also possible to add height information in the drawing process of computer graphics, which has recently developed. When displaying an actual object, the camera's autofocus distance measuring mechanism (for example, using reflected infrared light) and COD (C:hage Co., Ltd.)
Image information and distance information can be obtained by scanning an object by combining a photodetector such as an upgraded device (charge-coupled device), and the microcomputer 10
1, it can be sequentially converted into a pixel configuration including the height information shown in FIG. 1 and sent to the RAM 102, so that it can be displayed in the same way.

Figure 6 shows image information stored in the ROM log.
,・□ Shows the flowchart of the microcomputer when there is.

The circuit configuration shown in FIG. 5 is similar to a conventional graphic liquid crystal display circuit, and the conventional software and software of the microcomputer can be applied as is.

5TEP 1 - 5TEP 5 initializes image data to RAM and starts displaying. The actual display process is 5TEP 6 to 5TEP 10, but it only controls the 7 bits of the row address, and the microcomputer's The burden is small. At 5TEP6, if the CUP signal detects the count up of 4 bits of the column address, the row address is incremented by 1, and at 3TEP8, the vertical synchronization signal (V
SYNG) is detected, the line address is reset to the first address of the image data, and the display is started again from the first line. Then, the RAM output is stopped by an external termination signal, etc., and the display is terminated.

In the above embodiments, the substrate 10 or the electrode 11.1
A liquid crystal alignment film made of polyimide or the like may be provided inside the polarizer 2, and a transparent material such as glass may be placed between each of the polarizing plates 1 to 9.

Also, chiral smectic C phase, H phase, I phase, J phase,
When using ferroelectric liquid crystals such as K-phase, G-phase, and F-phase, the substrate alignment treatment (rubbing) direction is in the direction of the transmission axis of one of the polarizers (for example, the polarizing plate 14). It is better to make the single pixel matrix parallel to the other.Also, the divisions of the single pixel matrix are 3x3, but these nine divisions are, for example, 2X2.3X4
．． Any one such as 4X4 may be used.Furthermore, by making the angle of the display surface changeable, crosstalk can be prevented.

Although a transmission type display element has been described above, by arranging a reflection plate on the back side of the polarizing plate 1, it can also be a reflection type display element.

In the embodiments described above, the information on the frontmost side and the information on the farthest side are each displayed by one single pixel, but the depth information is displayed by, for example, single pixels 1 and 2 or single pixels 8 and 9.
By representing each with two single pixels, 1
The displayed image can be made denser across the entire display surface,
The image becomes easier to see.

[Effects of the Invention] In the present invention, polarizing plates with polarizers shifted in planar position are laminated on the front surface of a liquid crystal display element, and the distances from the surface of the liquid crystal display element to each polarizer are varied. , to obtain the sense of depth of the displayed image due to the difference in height between each pixel, and to adjust the dye concentration of the polarizing plate to the frontmost (viewing side)
By setting it so that it gradually decreases from the depth to the innermost part, the strength and weakness of the contrast of the image is further emphasized. Therefore, a display image can be expressed three-dimensionally with a simple device configuration, and information display can be made more realistic.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view showing an embodiment of the liquid crystal display device of the present invention, FIG. 2 is a diagram showing a liquid crystal optical modulation section configured in a matrix, FIG. 3 is a diagram showing a single pixel matrix in this embodiment, and FIG. 5 is an explanatory diagram showing the position of the polarizer of each polarizing plate in this embodiment. FIG. 5 is an explanatory diagram showing the overall configuration of the drive circuit in this embodiment. FIG. 6 is an explanatory diagram showing a flowchart in this embodiment. be. 1 to 9, 14: polarizing plate, la to 9a: polarizer, IO=substrate, 11: scanning electrode, 12: pixel (signal) electrode, 13: liquid crystal layer.

Claims (1)

[Claims] In a matrix type display panel using a liquid crystal display element constituted by a pair of transparent electrode substrates sandwiching a liquid crystal, the liquid crystal element corresponds to each pixel of the display panel and has a different distance from the liquid crystal element surface. A liquid crystal display device characterized by having a polarizing plate provided with a polarizer having a dye concentration that differs depending on the distance from the surface.