JP5185145B2 - Stereoscopic image display apparatus and stereoscopic image display method - Google Patents

Description

  The present invention relates to a stereoscopic image display device that can partially display a planar image.

  Various methods are known for stereoscopic image display devices capable of displaying a three-dimensional moving image, so-called three-dimensional displays. In recent years, observers have been controlling light beams from display panels that have fixed pixel positions, such as direct-view or projection-type liquid crystal display devices and plasma display devices, especially for flat panel types, which do not require special glasses. A stereoscopic image display method that generates parallax is known.

  The parallax generating means (also called parallax barrier or parallax barrier) controls the light beam so that different images can be seen depending on the angle even at the same position on the light beam control element. For example, when only left and right parallax (horizontal parallax) is given, a slit or a lenticular sheet (cylindrical lens array) is used. When giving vertical parallax (vertical parallax), a pinhole array or a lens array is used. Furthermore, systems using a parallax barrier are also classified into binocular, multi-view, super multi-view (multi-view super multi-view conditions), and integral photography (hereinafter also referred to as IP). In multi-view or one-dimensional IP (IP with only horizontal parallax), the viewing zone, resolution, and pop-out amount are trade-offs, and it is difficult to achieve sufficient levels for all three characteristics. In view of this, a time-division stereoscopic display method has been proposed in which a plurality of images are displayed on a display by switching over time, and a liquid crystal shutter is opened and closed in synchronization with the display to control each image so that it enters the corresponding eye. (For example, Patent Document 1). In the time-division stereoscopic display method, the number of light rays can be increased in the time direction, and the stereoscopic display performance can be improved.

  When character display is performed, it is necessary to partially perform high-resolution stereoscopic display or planar image display. A technique for partially switching between planar display and stereoscopic display within a screen using a liquid crystal lens has been proposed (for example, Patent Document 2). In this method, there is a problem that a luminance difference occurs between the flat display and the stereoscopic display. In addition, the number of rays cannot be increased in the time direction, and all of the three-dimensional display performance (resolution, viewing area, pop-out amount) cannot be improved.

Japanese Patent No. 3268586 WO 03/015424 A2

  In the above-described prior art, a stereoscopic display device capable of partially displaying in a plane cannot improve all the stereoscopic display performance (resolution, viewing area, pop-out amount).

An object of the present invention is to provide a technique for improving all of the stereoscopic display performance (resolution, viewing area, pop-out amount) even in a stereoscopic display device capable of partially displaying a flat surface.

In order to solve the above problems, the present invention has a first image display unit and a plurality of lenses provided on the front surface of the first image display unit, and controls light rays from the first image display unit. A liquid crystal panel that includes a parallax generating unit and a display surface provided in front of the parallax generating unit and having pixels arranged in a matrix and modulates the transmittance of light incident from the first image display unit. A second image display unit, a determination unit for determining whether each pixel is in a stereoscopic image display mode or a planar image display mode from the input signal, and a determination mode in which the determination unit performs a stereoscopic image display The element image corresponding to the input signal is displayed on the first image display unit at the pixel position of the selected pixel, and the first image is displayed at the pixel position of the pixel determined as the display mode in which the determination unit performs planar image display. Generates parallax light with a predetermined brightness A narrow and long shutter that allows light to be blocked is displayed at the pixel position of the first control unit that is emitted toward the pixel and the pixel position of the pixel that is determined as the display mode in which the determination unit performs stereoscopic image display. A plurality of shutter images arranged at positions corresponding to the upper element image are displayed on the liquid crystal panel, and the pixel position of the pixel determined as the display mode in which the determination unit performs planar image display corresponds to the input signal. A stereoscopic image display device comprising: a second control unit that displays a planar image on the liquid crystal panel; and a synchronization unit that synchronizes display timing and display position of the shutter image and the element image. I will provide a.

ADVANTAGE OF THE INVENTION According to this invention, even if it is a 3D display apparatus of the time division | segmentation 3D display system with high 3D display performance, a plane image and a 3D image can be selectively displayed for every area | region in a screen.

FIG. 2 is a horizontal sectional view showing an outline of the structure of the stereoscopic image display apparatus according to the first embodiment. The functional block diagram of the three-dimensional image display apparatus of 1st Embodiment. The figure which shows the concept of a time division | segmentation solid display. The figure which shows the example of the image displayed on a 1st display part and a 2nd display part. Diagram showing an example of the data structure of an 8-bit input signal for one pixel Diagram conceptually showing how to adjust the backlight brightness at the flat display position The figure which shows operation | movement of the three-dimensional image display apparatus of 1st Embodiment. The figure which illustrated the relationship between the arrangement | sequence of the pixel of a color filter, and the inclination of the lens for parallax generation. The figure which illustrated the relationship between the arrangement | sequence of the pixel of a color filter, and the inclination of the lens for parallax generation. The horizontal sectional view which shows the outline of the structure of the three-dimensional image display apparatus of 2nd Embodiment. The figure which shows the outline of the structure of the three-dimensional image display apparatus of 3rd Embodiment.

Hereinafter, a stereoscopic image display device according to an embodiment of the present invention will be described in detail with reference to the drawings. Here, the same reference numerals are assigned to the same components, and the duplicate description is omitted.
[First embodiment]
FIG. 1 is a horizontal sectional view showing the structure of the display unit of the stereoscopic image display apparatus according to the present embodiment.

  In FIG. 1, the upper side is the observer side, that is, the light emission side by the backlight 100. The stereoscopic image display apparatus according to the present embodiment includes a first display unit 200, a parallax generating lens 300, and a second display unit 400 in this order.

  The first display unit 200 is a planar light source, and includes a backlight 100 that emits light to the observer side, and a liquid crystal panel 500.

  The liquid crystal panel 500 includes a polarizing plate 201 having a polarization direction that transmits light that vibrates in a predetermined direction, and a glass plate 202 that is a light-transmitting insulator. A transparent electrode 203 having a plurality of wiring patterns, a liquid crystal layer 204 having initial alignment of liquid crystal molecules aligned in one direction, a transparent electrode 205 having a plurality of wiring patterns, and R (red), G (green), B ( A color filter 206 in which sub-pixels of blue) are arranged on the image display surface in an array, a glass plate 207 that is a light-transmitting insulator, and a polarizing plate 201 that transmits light that vibrates in a predetermined direction. A polarizing plate 208 having polarization directions orthogonal to each other is provided in this order.

  In the liquid crystal layer 204 held between the transparent electrode 203 and the transparent electrode 205, liquid crystal molecules are aligned so that the major axis direction is a constant direction in the initial alignment without the influence of an electric field. Each liquid crystal molecule in the liquid crystal layer 204 changes its orientation according to the voltage applied to each wiring pattern of the transparent electrode 230 and the transparent electrode 205, and adjusts the luminance of light in an arbitrary polarization state that passes through the liquid crystal layer 204. To do.

  The parallax generating lens 300 is an optical element for generating parallax in the left and right eyes of the observer. In the present embodiment, an example in which a lenticular sheet is used as the parallax generating lens 400 is illustrated, but a fly-eye lens may be used. In addition, the lens convex portion of the parallax generating lens 300 may face either the first display unit 200 side or the second display unit 400 side.

  The second display portion 400 includes a polarizing plate 401 having the same polarization direction as the polarizing plate 208, a glass plate 402 that is a light-transmitting insulator, and a plurality of glass plates 402 that are disposed to face the emission surface of the backlight 100. A transparent electrode 403 having a wiring pattern, a liquid crystal layer 404 having initial alignment of liquid crystal molecules aligned in one direction, a transparent electrode 405 having a plurality of wiring patterns, and R (red), G (green), and B (blue) The color filter 406 in which the sub-pixels are arranged on the image display surface in an array, the glass plate 407 that is a light-transmitting insulator, the light that vibrates in a predetermined direction, and the polarizing plate 401 face each other. And a polarizing plate 408 having a polarization direction to be provided in this order.

  The first display unit 200 is not limited to the liquid crystal panel described above, and may be a self-luminous display device such as a display device such as an organic EL panel, a plasma display device, or a field emission display device. It should be noted that such a self-luminous display device does not require the backlight 100.

  Note that as the polarizing plates 201, 208, 401, and 408, linear polarizing plates, circular polarizing plates, elliptical polarizing plates, or the like can be used. The backlight 100 may be a general fluorescent tube or LED backlight, a light guide plate and a diffusion plate.

  FIG. 2 is a diagram illustrating an example of images displayed on the first display unit 200 and the second display unit 400 of the present embodiment.

  FIG. 2A is a diagram illustrating an example of an image displayed on the first display unit 200. The first display unit 200 displays, on the first display unit 200, element images according to the input element image array for pixels in a display mode that displays a stereoscopic image (also referred to as a 3D image). Here, the element image array is an image for one frame obtained by integrating a plurality of element images, each of which is a left-eye image or a right-eye image, which is a source of a stereoscopic image. It is assumed that the element image includes a number of viewpoint images corresponding to the number of viewpoints obtained by photographing an object to be stereoscopically displayed from a plurality of viewpoints. When these element images are observed through the parallax generation lens 300, the viewpoint images at the same viewpoint position included in each element image can be selectively viewed due to the binocular parallax generated by the parallax generation lens 300. Become. Thereby, as viewed from the observer, the group of element images is recognized as a stereoscopic image formed at a predetermined position.

  For a pixel in a display mode that displays a planar image (also referred to as a 2D image), the pixel position is used as a backlight region, and light having a predetermined luminance is emitted toward the second display unit 400. A method for adjusting the luminance of the backlight area will be described later.

  FIG. 2B is a diagram illustrating an example of an image displayed on the second display unit 400. The second display unit 400 is controlled to display a shutter image at the pixel position of the pixel in the display mode for performing stereoscopic display. Here, the shutter image has a structure in which a plurality of shutter elements that shield a plurality of lights are arranged so as to extend in a substantially vertical direction. Each shutter element is arranged corresponding to an area equal to the area of one lens viewed from the front of the parallax generating lens 300. A long and narrow area corresponding to one lens may be divided into a plurality of short parts to form a plurality of shutter elements arranged vertically. Further, as a modified example, the shutter element may be disposed so as to be opposed obliquely at an angle relative to the lens of the parallax generating lens 300 later. Therefore, the fact that each shutter element extends along the substantially vertical direction is not limited to the case where the extending direction coincides with the vertical direction, but also includes the case where an angle is formed with respect to the vertical direction (column direction). . When each shutter element extends at an angle with respect to the vertical direction, the shutter elements that extend obliquely are arranged in the horizontal direction (row direction). In FIG. 2B, the portions schematically shown in white and black as shutter images represent the transmission and light shielding states in a certain field, respectively. In this example, one frame is divided into two fields, and the shutter is opened and closed so that ½ lenses (even number or odd number) of the total number of lenses per field are in a transmission state.

  The second display unit 400 is controlled to display an image having a pixel value according to the input planar image at the pixel position of the pixel in the display mode for performing planar display. A planar image can be displayed by transmitting light from the backlight region of the first display unit 200.

  FIG. 3 is a diagram illustrating the concept of time-division stereoscopic display. An element image corresponding to one frame of a stereoscopic display image is composed of n fields having a time division number n. FIG. 3 shows an example where n = 2. In this case, the shutter that blocks the light from the first display unit 200 in the second display unit 400 is opened and closed for each adjacent lens width of the parallax generating lens 300. By switching the opening / closing of the shutter and the field of the element image at a speed of 120 Hz or more, the number of parallaxes can be effectively expressed twice as compared with the case of displaying at 60 Hz.

  FIG. 4 is a functional block diagram illustrating the stereoscopic image display apparatus according to the present embodiment. The stereoscopic image display apparatus according to the present embodiment includes a determination unit 11, a first control unit 12, a second control unit 13, a storage unit 14, and a synchronization control unit 15.

  The determination unit 11 determines from the input signal whether each pixel is in a display mode of stereoscopic image display or planar image display. The display mode is performed based on the input signal, and the data structure of the input signal will be described later with reference to FIG.

  The first control unit 12 controls the image displayed on the first image display unit 200. Specifically, the direction of the liquid crystal is controlled by controlling the voltage applied to the transparent electrodes 203 and 205 of the first display unit 200. Accordingly, an image can be displayed by controlling the polarization state of light passing through each pixel of the color filter 206. The first control unit 12 controls an image to be displayed according to the display mode of each pixel determined by the determination unit 11. Specifically, as described above, the element image is displayed at the pixel position of the pixel determined to be the display mode for performing the stereoscopic image display, and the pixel position of the pixel determined to be the display mode for the planar image display is set to the predetermined position. An image is displayed that forms a backlight region that emits light of luminance toward the parallax generation lens 300. The first control unit 12 stores the input element image array in the storage unit 15 and divides the stored element image array into n time-division element images (n is an integer of 2 or more). These element images are switched at predetermined time intervals and displayed on the display surface of the first display unit 200.

  The storage unit 14 stores the element image array.

  Similar to the first control unit 12, the second control unit 13 controls the voltage applied to the transparent electrodes 403 and 405 of the second display unit 200 to thereby display an image to be displayed on the second image display unit 400. Control. Specifically, as described above, the shutter image is displayed at the pixel position of the pixel determined as the display mode for performing the stereoscopic image display. A shutter opening / closing signal synchronized with the vertical scanning signals of the first and second fields of the element image is generated, and a vertical driving signal and a horizontal driving signal corresponding to the shutter opening / closing signal are generated. The input image is displayed at the pixel position of the pixel determined as the display mode for performing the planar image display.

  The synchronization control unit 15 synchronizes the switching timing of the element image displayed on the first display unit 200 and the shutter image displayed on the second display unit 400 at predetermined time intervals in the first field. A signal and a vertical scanning signal for the second field are generated and sent to the first controller 12 and the second controller 13.

  FIG. 5 is a diagram illustrating an example of a data structure of an 8-bit input signal for each sub-pixel of one pixel according to the present embodiment. Among the input signals, the upper 6 bits, that is, the upper 7 to 2 bits indicate the pixel values of the sub-pixels of the element image and the planar image that are color images. For example, in the case of a color image signal in the RGB format, an 8-bit signal is assigned to each RGB sub-pixel. The middle 1 bit indicates the gradation of the shutter image or the backlight area. When it is 0, black is displayed and when it is 1, white is displayed. The lower 1 bit is used for determining the display mode of each pixel. When it is 0, it is the element image display mode, and when it is 1, it is the plane image display mode.

  FIG. 6 is a diagram conceptually showing a method for adjusting the backlight luminance at the flat display position. When a stereoscopic image is displayed with the same brightness value of the backlight 100 and when a planar image is displayed, the brightness is higher when the planar image is displayed. Therefore, if the brightness of the backlight area is not adjusted when a planar image and a stereoscopic image are displayed simultaneously, the brightness difference is perceived unnaturally. Therefore, in the present embodiment, in order to reduce the luminance of the entire backlight region, black dots are replaced with the backlight region portion of the first image display unit 200 according to the middle 1-bit gradation shown in FIG. To display. Thereby, the transmittance of light transmitted through the backlight region is set to less than 100%. Accordingly, the brightness can be adjusted so that the brightness of the planar image and the stereoscopic image is the same at the position of the observer.

  FIG. 7 is a diagram illustrating an operation of the stereoscopic image display apparatus according to the present embodiment.

  First, as shown in FIG. 5, the color image signal from the lower 1 bit to the upper 2 to 7 bits specifies the bit part of the image signal used in the element image, the backlight image, the shutter image, and the planar image, and all the image signals Is input in a state of being combined into one sheet (S101). The element image and the planar image show an example in which the upper 6 bits of the 8-bit BMP image signal are set, the middle 1 bit is used for the shutter image and the backlight luminance adjustment dot image, and the position determination signal is set to the lower 1 bit.

  First, the determination unit 11 determines a display mode from the input signal (S102).

  When the display mode is the stereoscopic display mode (S102, Yes), the synchronization control unit 15 acquires the address of the corresponding pixel (S103). In the case of a signal in which pixel information is sent in the raster order of the frame, it is determined by what number the pixel has been sent in the frame. When the address is found, the synchronization control unit 15 sends the pixel address to the first control unit 12 and the second control unit. The first control unit 12 designates the upper 6 bits of the input signal (S104). Further, the synchronization control unit 15 designates the middle 1 bit of the input signal and inputs it to the second control unit 13 (S107). The first control unit 12 displays the upper 6-bit element image on the first display unit 200 (S105). In addition, the second control unit 13 causes the second display unit 400 to display a middle 1-bit shutter image (S108). In these display operations S108 and S105, the shutter image and the element image are displayed simultaneously in accordance with the synchronization signal sent from the synchronization control unit 15.

  When the display mode is the flat display mode (S102, No), the synchronization control unit 15 acquires the address of the corresponding pixel (S109). In the case of a signal in which pixel information is sent in the raster order of the frame, it is determined by what number the pixel has been sent in the frame. When the address is found, the synchronization control unit 15 sends the pixel address to the first control unit 12 and the second control unit. Also, the synchronization control unit 15 designates the upper 6 bits of the input signal and inputs it to the second control unit 13 (S113). Further, the synchronization control unit 15 designates the middle 1 bit of the input signal and inputs it to the first control unit 13 (S110). The second control unit 13 displays the upper 6-bit plane image on the second display unit 400 (S114). In addition, the first control unit 12 causes the second display unit 200 to display an image of the lower 1-bit backlight area (S111). In these display operations S111 and S114, the planar image and the image of the backlight area are simultaneously displayed according to the synchronization signal sent from the synchronization control unit 15.

  8 and 9 are diagrams illustrating the relationship between the pixel arrangement of the color filter 206 of the first display unit 200 and the inclination of each lens of the parallax generating lens 300. FIG. Since the lens installed on the pixel enlarges and displays the sub-pixels of the color filter 206, it is necessary to emit light from the RGB sub-pixels in the same direction as one set. For example, the lens ridge line direction is inclined with respect to the arrangement direction of the R color filters.

  FIG. 8 shows a case in which an oblique lens having a ridge line direction inclined with respect to a stripe arrangement in which RGB pixels are arranged in the same color and vertically is used.

  FIG. 9 shows a case where a mosaic arrangement in which RGB pixels are arranged at an inclination of arctan (1/3) and a vertical lens having no inclination with respect to the column direction of the pixels are used. With these arrangements, even if the RGB color filter section is separated by directivity by the lens, RGB light is emitted in the same direction, and a white image can be reproduced.

[Second Embodiment]
FIG. 10 is a horizontal sectional view schematically showing the structure of the stereoscopic image display apparatus according to this embodiment.

  The first display unit 210 and the second display unit 410 are different from the stereoscopic image display device of FIG. 1 in that each has a polarizing plate 211 and a polarizing plate 411. The polarizing plate 211 and the polarizing plate 411 have polarization directions opposite to each other.

  The polarizing plate 211 is provided so as to face the exit surface of the backlight 100. Transparent electrodes 203 and 205, a liquid crystal layer 204, and a color filter 206 sandwiched between glass plates 202 and 207 are formed above the polarizing plate 211.

  The parallax generating lens 300 is placed in close contact with the back surface of the glass plate 207 of the first display unit 210. A glass plate 402 is placed in close contact with the upper part of the parallax generating lens 300.

  Transparent electrodes 403 and 405, a liquid crystal layer 404, and a color filter 406 sandwiched between glass plates 402 and 407 are configured. The polarizing plate 411 is provided in close contact with the glass plate 407.

  According to the stereoscopic image display apparatus of the present embodiment, the number of light shielding plates that are transmitted before the light emitted from the backlight 100 reaches the observer is smaller than that of the stereoscopic display apparatus of FIG. The brightness of the image to be improved can be improved. Further, since two polarizing plates can be omitted as compared with the stereoscopic image display device of the first embodiment, a thinned structure and a high luminance display can be realized.

[Third Embodiment]
FIG. 11 is a diagram showing an outline of the stereoscopic display device of the present embodiment.

This embodiment is different from the stereoscopic display device of the first embodiment in that the backlight 100 has a plurality of minute LEDs. Each LED can adjust the brightness of the emitted light. In the stereoscopic display device shown in FIG. 9, black dots are displayed in the backlight area in order to eliminate the luminance difference between the planar image and the stereoscopic image displayed at the same time. However, in the present embodiment, positions corresponding to the backlight area are displayed. The brightness of the light emitted from the LED is reduced.

DESCRIPTION OF SYMBOLS 200,210 ... 1st display part 100 ... Backlight 500, 510 ... Liquid crystal panel 201 ... Polarizing plate 202 ... Glass plate 203 ... Transparent electrode 204 ... Liquid crystal layer 205 ... Transparent electrode 206 ... Color filter 207 ... Glass plate 208 ... Polarizing plate 211 ... Polarizing plate 300 ... Parallax generating lenses 400, 410 ... Second display unit 401 ... -Polarizing plate 402 ... Glass plate 403 ... Transparent electrode 404 ... Liquid crystal layer 405 ... Transparent electrode 406 ... Color filter 407 ... Glass plate 408 ... Polarizing plate 411 ... Polarized light Plate 11 ... Determination unit 12 ... First control unit 13 ... Second control unit 14 ... Storage unit 15 ... Synchronization control unit

Claims (5)

A first image display unit;
A parallax generating unit that has a plurality of lenses provided on the front surface of the first image display unit and controls light rays from the first image display unit;
Second image display having a liquid crystal panel provided on the front surface of the parallax generator, having a display surface in which pixels are arranged in a matrix, and modulating the transmittance of light incident from the first image display unit And
A determination unit that determines whether each pixel is in a stereoscopic image display mode or a planar image display mode from an input signal;
A display mode in which an element image corresponding to the input signal is displayed on a first image display unit at a pixel position determined as a display mode in which the determination unit performs stereoscopic image display, and the determination unit performs planar image display. A first control unit that causes the first image display unit to emit light having a predetermined luminance toward the parallax generation unit at the pixel position of the pixel determined as:
At the pixel position of the pixel determined as the display mode in which the determination unit performs stereoscopic image display, the shutter image is displayed on the liquid crystal panel, and at the pixel position of the pixel determined as the display mode in which the determination unit performs planar image display A second control unit for causing the liquid crystal panel to display a planar image corresponding to the input signal;
Display timing and display of the shutter image formed by arranging a plurality of narrow and long shutters that can block light displayed on the liquid crystal panel and the element image displayed on the first image display unit A synchronization unit for synchronizing positions;
A stereoscopic image display device comprising: The first image display unit includes:
A backlight that emits light;
A liquid crystal panel for modulating the transmittance of light from the backlight;
Have
2. The stereoscopic image according to claim 1, wherein the first control unit reduces light transmittance of the liquid crystal panel at a pixel position of a pixel that is determined to be a display mode in which the determination unit performs planar image display. Display device.   The said 1st control part makes the light transmittance of the said liquid crystal panel be a light-shielding state by a predetermined | prescribed ratio in the pixel position of the pixel which the said determination part determined as the display mode which performs a planar image display. Item 3. The stereoscopic image display device according to Item 1. The backlight has a plurality of light sources each capable of controlling the brightness of light,
The first control unit is configured to display the intensity of light emitted from the light source at a position corresponding to the pixel position of the pixel determined as the display mode in which the determination unit performs planar image display and the display mode in which the stereoscopic image display is performed. The stereoscopic image display apparatus according to claim 2, wherein the intensity of light emitted from the light source is made smaller at the pixel position of the determined pixel. The input signal includes a determination signal that specifies whether each pixel of the image signal is a stereoscopic image display or a planar image display, an image signal that is displayed in a display mode indicated by the determination signal, and the stereoscopic image display . shutter image when a display mode in which any of the preceding claims, characterized in that and a signal designating a gradation display mode in the case when backlight image to be the planar image display A stereoscopic image display device according to claim 1.