JPH0760295B2 - 3D image display method - Google Patents

Description

TECHNICAL FIELD The present invention relates to an image display method for stereoscopically displaying an image in a display device using various optical modulation elements.

[Prior Art] There have been several attempts to display images three-dimensionally. As such, using holograms, glasses of different colors on the left and right, or PL
There has been one that utilizes parallax between both eyes, such as temporally modulating with glasses made of shutters such as ZT.

[Problems to be Solved by the Invention] As described above, although there are several methods of displaying an image three-dimensionally, it takes time to record a signal wave in the former case, and in the image display device for the latter case. There were difficulties such as the need for synchronized glasses.

It is an object of the present invention to provide a novel stereoscopic image display method that solves the above-mentioned drawbacks of the prior art.

That is, an object of the present invention is to provide an image display method capable of easily displaying a stereoscopic image by the display device itself without using any other tool.

[Means for Solving Problems] The present invention is a stereoscopic image display method on a display screen in which pixels, which are display units, are arranged in a matrix, and the pixels are further arranged in a matrix. It is divided into single pixels, and each of the single pixels is pre-grouped into a plurality of modulation units having different heights and areas, and according to the height information of the signal transmitted for each pixel. , A stereoscopic image display method for displaying an arbitrary stereoscopic image by selectively turning on the modulation unit.

To further explain the present invention, in the present invention, a pixel of a display unit is divided into M single pixels to form a single pixel matrix, and a total of N single pixels are displayed according to N heights to be displayed. The modulation units are grouped (M> N).
By this grouping, the number of single pixels included in each modulation unit changes according to the display height, and the area of each modulation unit becomes different.

In addition, in the present invention, the polarizer corresponding to each single pixel is arranged according to the height assigned to each of the modulation units. Specifically, by stacking N sheets of polarizing plates each having a polarizer at the position of a corresponding modulation unit in order so as to have the above-mentioned predetermined height, the distance (height) from each liquid crystal element surface of each polarizer is increased. ) Is changed for each modulation unit to make the heights of the respective modulation units different from each other.

[Operation] Whether the display state of the pixel looks "dense" depending on which modulation unit in one pixel is turned on because the area of each modulation unit (the number of single pixels included in each modulation unit) is different It is selected whether it looks "coarse". And "dense"
Since the display of pixels that appear to be visible and the display of pixels that appear to be “coarse” provide a sense of depth, this allows a stereoscopic effect to be obtained.

Moreover, since the heights of the polarizers are different, a step can be provided between the display positions of the modulation units. Since this step also gives a sense of depth, a three-dimensional effect can be obtained also by this.

[Embodiment] First, the configuration and operation of the image display device in this embodiment will be described.

FIG. 2 shows a liquid crystal optical modulator having a matrix structure. Examples of driving methods for each modulator include TFT (thin film transistor) driving, simple matrix driving, and multiple matrix driving. These driving methods include TN (twisted nematic) liquid crystal and ferroelectric liquid crystal (US Pat. No. 436792).
Chiral smectic C phase or H described in Japanese Patent No. 4
Phase) etc. are used.

FIG. 3 shows a 4 × 4 single pixel matrix sectioned by an alternate long and short dash line in FIG. 2, and each single pixel is numbered from 1 to 5.

FIG. 4 shows the position of the polarizer in each polarizing plate arranged behind the liquid crystal photon modulation section. The polarizing plate 1 laminated on the foremost part is provided with five polarizers at positions corresponding to 1 in the 4 × 4 single pixel matrix shown in FIG.
The polarizing plate 2 is provided with four polarizers at positions corresponding to 2 in FIG. Similarly, all the polarizing plates up to the polarizing plate 5 arranged in the innermost part are provided with polarizers at positions corresponding to single pixel numbers. In addition, in FIG. 4, a black background part shows a polarizer, and a white background part shows a transparent part without a polarizer.

FIG. 1 is a sectional view of the liquid crystal display device according to this embodiment. In the figure, reference numerals 1 to 5 denote the above-mentioned polarizing plates, which show a state in which the polarizing plates 1 to 5 arranged at the forefront are sequentially laminated on the back surface of the liquid crystal display element. The polarizing plate used in this example can be produced by coating a dye on a stretched polymer such as polyvinyl alcohol with a mask.

In the figure, 11 is a transparent scanning electrode such as ITO (Indium-Tin-Oxide), 12 is a pixel electrode also made of ITO, and the liquid crystal layer 13 sandwiched between these electrodes is used for TFT driving or other It is conventionally modulated by the matrix driving method. 10 is a transparent substrate such as glass, 14 is a polarizing plate whose entire surface is provided on the front surface of the element and the transmission axes of the polarizing plates 1 to 5 are parallel to each other, and are orthogonal to the transmission axis of the polarizing plate 14. It should be placed.

Next, referring to FIG. 1, a basic operation will be described in the case where a twisted nematic liquid crystal, which is well known as a liquid crystal material, is used.

In FIG. 1, mark A indicates the transmission axis direction of each polarizer in the polarizing plates 1 to 5, Shows the transmission axis direction of the front side polarizing plate 14. That is, the transmission axis directions of the front and rear polarizers are in a state of being orthogonal to each other in a plane. When a voltage exceeding the threshold of the liquid crystal is not applied between the electrodes of the display element in which the polarizers are orthogonally opposed to each other in this way, the incident light L is linearly polarized by the polarizers of the polarizing plates 1 to 5 and the liquid crystal. Enter the layer. Here, the incident light L is illuminated by the nematic liquid crystal having a positive dielectric anisotropy by about 90 ° along the twist of the liquid crystal molecules. Therefore, the incident light L passes through the polarizing plate 14 and appears white on the surface. On the other hand, when a voltage equal to or higher than the threshold value of liquid crystal is applied between the electrodes, the liquid crystal molecules are aligned substantially perpendicular to the electric field direction. Therefore, the light dimming property is lost, and the incident light L cannot be seen from the polarizing plate 14 side, so that the polarizing plates 1 to 5 appear black. That is, bright / dark display is performed by controlling the voltage between the pixel electrode and the scan electrode corresponding to an arbitrary single pixel.

More specifically, for example, when a voltage is applied to the liquid crystal layer corresponding to the pixel 1 (that is, the polarizing plate 1) in FIG. 3, the five polarizers provided on the polarizing plate 1 look black, and An image is displayed at the forefront of. Similarly, when a voltage is applied to the liquid crystal layer corresponding to the pixel 5, the two polarizers provided on the polarizing plate 5 appear black and an image is displayed at the innermost portion. In this way, the raised image is recognized as a stereoscopic effect due to the area ratio of the polarizers in the upper and lower polarization plates and the perspective due to the step.

In the above embodiment, the arrangement of the polarizers formed on each polarizing plate is arranged on the 4 × 4 single pixel matrix as shown in FIG. 3 to represent the depth information, but this arrangement pattern is further changed. By this, the object to be displayed is
Furthermore, depth information can be given.

According to the above, the number of polarizers formed on the polarizing plate 1 is 4 ×
5 pieces are formed in a matrix of 4 single pixels, and 4 pieces are formed in the polarizing plate 2 ...
For example, by increasing the area ratio of the polarizer formed at the forefront and increasing the foreground image, such as three for the polarizing plate 2 and three for the polarizing plate 2, more depth information can be provided.

Further, although the polarizers at the same height are arranged adjacent to each other, it is also possible to disperse the arrays all over.

Although the single pixel matrix of the liquid crystal is 4 × 4, this may be 3 × 3, 5 × 5 or any other type.

On the other hand, a liquid crystal alignment film of polyimide or the like may be provided inside the substrate 10 or the electrodes 11 and 12 of the above embodiment. If necessary, a transparent material such as glass may be provided between the polarizing plates 1 to 5. Also, chiral smectic C
It is preferable that the substrate orientation treatment (rubbing) direction when using a ferroelectric liquid crystal of a phase or H phase is parallel to the transmission axis direction of the polarizing plate 14, for example.

Furthermore, although a transmissive TN liquid crystal cell has been described in the above-mentioned embodiment, a reflective type in which a reflection plate is arranged further behind the polarizers 1 to 5 may be used.

In the above, the height information display pixel is provided by giving different heights to the polarizer behind the liquid crystal cell in the matrix configuration.
For example, instead of the liquid crystal cell, a solid-state optical modulation element such as PLZT in which a modulation part is configured in a matrix may be used, and more simply, an ECD (electrochromic element), an LED, an ELD (electroluminescence) may be directly used. A three-dimensional image display can also be performed by arranging a color-developing element such as a light emitting element) and a light-emitting element in the same manner as the above-mentioned polarizer.

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

FIG. 5 is an overall configuration diagram showing a 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) that can store image information for one screen.
m Access Memory; eg 2K static RAM). 103 is RA
A shift register that sends the data in M to the LCD driver 105 serially. 104 is a counter group that counts the operation clocks generated by the clock generator 107. The data load signal of the shift register 103 and the column address 4 of the RAM
Bit signal / column address count amplifier known to CPU (microcomputer 101) signal / LCD driver 105 HSYNC
(Horizontal sync signal), VSYNC (vertical sync signal), etc. are generated. Reference numeral 105 denotes a driver for a liquid crystal graphic display, which can display, for example, 320 × 40 bits by giving a serial data signal, HSYNC VSYNC, and a clock. A ROM 106 stores programs and display image data of the microcomputer 101. 107 is the shift register 10
3, a clock generator for operating the counter group 104 and the liquid crystal driver 105.

First, the microcomputer 101 is stored in a ROM (Read Only Memory) 106. The image information of a screen is transferred to the RAM 102.
Of course, at this time, direct memory access (DM
A) A controller may be used. This image information is
The pixel configuration is as shown in FIG.

The image information transferred to the RAM 102 is a shift register as 8 bits of data indicated by a row address of 7 bits by the microcomputer 101 and a column address of 4 bits by the counter 104.
Sent to 103. The 4-bit column address is incremented by 1 every 8 clocks, and 8-bit data is sent to the shift register 103 each time the 4-bit counts up (that is, 16 bytes are transferred). To the CPU, which causes the microcomputer 101 to increment the row address by 1.
Transfer the next data.

On the other hand, the data transferred to the liquid crystal driver 105 is stored for one row, latched by the input of the HSYNC signal, sent to the signal electrode for display, and the first row is displayed. Meanwhile, next 2
The image information of the line is serially sent to the register, and the next
It is also latched by the 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 line is repeated by repeating this, the VSYNC signal causes the line control signal to scan again from the first line.

The HSYNC signal and VSYNC signal are output by counting up the clock signal by the couter group 104. For example 320
In the display element of × 40 dots, the counter group 104 is configured such that the HSYNC signal is output every 320 bits and the VSYNC signal is output every 40 counts of the HSYNC 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 phase display element.

Since the RAM 102 can store information for one screen of the liquid crystal display element, RAM 1 is once displayed when displaying a still image.
If data is transferred to 02, the display can be continued in the above method. If you want to make a movie,
If the 101 transfers the continuous image information from the ROM 106 to the RAM 102 one after another, the display image can be moved accordingly. In this case, the contents of the RAM 102 can be changed entirely or only the range related to the movement can be changed. It is easy to create image information having height information from a plane projection view of a three-dimensional object and its height information on a personal computer. It is also possible to add height information in the computer graphics drawing process that has recently been developed. When displaying an actual object, the camera's auto-focus distance measuring mechanism (for example, infrared reflected light is used) and CCD (Charge Coupled Device;
Image information and distance information can be obtained by interlocking light receiving elements such as charge-coupled elements) and scanning an object, and the microcomputer 101 sequentially replaces the pixel configuration with the height information shown in FIG. Then, it can be sent to the RAM 102 and displayed in the same manner.

FIG. 6 shows a flowchart of the microcomputer when image information is stored in the ROM. The circuit configuration of FIG. 5 is the same as that of the conventional graphic liquid crystal display circuit, and the software of the microcomputer can be applied as it is. STEP1 ~ STEP5 is the image data
Initialize RAM and start display. The actual display process is STEP6 to STEP10, but the burden on the microcomputer is small because only the control of the 7-bit line address is performed.
In STEP6, if the CUP signal is detected for counting up the column address 4 bits, the row address is incremented by 1. If STEP8 detects the vertical synchronization signal (VSYNC), the row address is reset to the top address of the image data. Display from the first line again. Then, the RAM output is stopped by an external end signal or the like to end the display.

[Advantages of the Invention] The present invention is to obtain depth information generated by a step between upper and lower modulation units when seen in a plan view. By emphasizing different heights, the visual stereoscopic effect is further enhanced. Therefore, unlike various conventional stereoscopic display devices, it is not necessary to use a complicated mechanical device or a tool other than the device, and the stereoscopic image can be more realistically represented by the display device itself.

[Brief description of drawings]

FIG. 1 is a sectional view of a liquid crystal display device according to this embodiment, and FIG.
FIG. 3 is a diagram showing a liquid crystal optical modulator having a matrix structure,
The figure shows a single pixel matrix in the present embodiment,
FIG. 5 is an explanatory view showing the position of the polarizer of each polarizing plate in this embodiment, FIG. 5 is an explanatory view showing a drive circuit in this embodiment, and FIG. 6 is an explanatory view showing a flow chart of a microcomputer. 1 to 5, 14: polarizing plate, 10: substrate, 11: scanning electrode, 12: pixel electrode, 13: liquid crystal layer.

 ─────────────────────────────────────────────────── ─── Continued Front Page (72) Inventor Yoichi Kubota 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (72) Inventor Hiroshi Tanioka 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Incorporated (72) Inventor Shuzo Kaneko 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (72) Inventor Kazutoshi Shimada 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. ( 72) Inventor Yukio Nagase 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (56) References JP 54-4155 (JP, A) SAI 59-123882 (JP, U) Actual Opened 54-118090 (JP, U) Actually opened 54-86982 (JP, U)

Claims (1)

[Claims] 1. A stereoscopic image display method on a display screen in which pixels which are display units are arranged in a matrix, wherein the pixels are further divided into single pixels arranged in a matrix, and Each of the single pixels is pre-grouped into a plurality of modulation units having different heights and areas, and the modulation units are selectively turned on according to the height information of the signal transmitted for each pixel. A three-dimensional image display method characterized by displaying an arbitrary three-dimensional image by performing.