WO2012105720A1

WO2012105720A1 - Three-dimensional image display device

Info

Publication number: WO2012105720A1
Application number: PCT/JP2012/052801
Authority: WO
Inventors: 掛谷　英紀
Original assignee: 国立大学法人筑波大学
Priority date: 2011-02-02
Filing date: 2012-02-01
Publication date: 2012-08-09
Also published as: JP2012159776A

Abstract

The present invention achieves a color three-dimensional image display device that is anaglyphic and that is a display device having a normal refresh rate. With respect to either a right-eye image or a left-eye image, a time division multiplexing image display means displays on one display screen via time division multiplexing a plurality of color three-dimensional images containing an image that is at least one of R, G, and B, and that is to be displayed. The right-eye and left-eye image are images having different colors, are displayed simultaneously, and via time division multiplexing, the left-eye and right-eye image are alternatingly displayed. Also, there is a time division multiplexing image separation means for the right eye and for the left eye, and each is a color filter that has cyclically changing transmitted wavelength characteristics. The transmitted wavelength characteristics change synchronously with the image display device, and of the transmitted wavelength characteristics of the color filter for the right eye or the left eye, the transmittance of the color of the image displayed correspondingly for the right eye or the left eye is higher than the transmittance of other colors.

Description

Stereoscopic image display device

The present invention relates to a stereoscopic image display device capable of suppressing the occurrence of flicker when a three-dimensional image is displayed on an image display device with a low refresh rate compared to the case where a conventional display method is used.

The history of stereoscopic image display devices is long, and various devices have been invented since the end of the 19th century. Among them, a stereoscopic image display device using a display device such as a cathode ray tube, a liquid crystal display panel, a plasma display panel, or a digital micromirror device (DMD: Digital Micromirror Device) is used as a device capable of displaying a color stereoscopic image. The video projector type stereoscopic image display device used is well known.
In order to display a stereoscopic image using these display devices, images for the right eye and the left eye are displayed to the observer. In this case, time-division display is often performed in order to display the pixels of the display device with high resolution without dividing the pixels of the right eye and left eye into two. In this case, in order to separate the time-division displayed image for the right eye and the left eye, shutters synchronized with the above time division are provided for the right eye and the left eye. In addition, the time-division display includes a frame sequential method in which left and right switching is performed for each frame and a field sequential method in which each field is switched, but the shutter switching frequency in the latter field sequential method is higher than that of the former. It will be higher except in special cases. For this reason, a shutter system that uses a right-eye shutter and a left-eye shutter in a time sequential display of a frame sequential system is often used. This shutter is realized by, for example, electrically controlling the polarization characteristics of the liquid crystal. (1) When the observer wears a liquid crystal shutter that opens and closes to the left and right, and (2) the observer. In some cases, a polarizing filter is used, that is, polarizing glasses that transmit circularly polarized light in the opposite directions on the left and right sides are applied, and the circularly polarized state of the light emitted from the display surface is switched on the display device side.
Here, in the case of (1) above, when a frame rate of 60 Hz (60 images per second) is realized, the plasma display is suitable for liquid crystal shutter glasses by switching the left and right images at twice 120 Hz. Image. This is because the plasma display uses an impulse display method, and all pixels simultaneously discharge plasma for a short time and then turn off. On the other hand, in a liquid crystal display, it is necessary to make it 240 times of 240 Hz. This is because the liquid crystal display rewrites the image for the left or right eye after the drawing of the image for the right or left eye is finished, and thus needs to hide the image being rewritten.
Also, in the case of (2), as in the case of (1), when realizing a frame rate of 60 Hz (60 images per second), the plasma display switches the left and right images at 120 Hz, which is doubled. However, in a liquid crystal display, it is necessary to make the frequency 240 times that of 240 Hz.
Anaglyph is known as a substantially monochromatic stereoscopic image display method. In this method, images of colors complementary to each other are presented to the observer, and the respective images are presented to the right eye and the left eye via filters that transmit either one of the complementary colors or the other. In addition, Dolby 3D is known as an anaglyph capable of displaying a color stereoscopic image. This presents a three-dimensional image using the first set of three primary colors of red, green, and blue and the second set of three primary colors slightly shifted in wavelength from each set for the right eye and the left eye, respectively. Therefore, a stereoscopic image is displayed by wavelength multiplexing.
In Patent Document 1, the first set and the second set of light sources of the three primary colors are configured as LED sets, and the LEDs are alternately arranged in the same display panel shape, and one of the first set and the second set is arranged. A method of displaying a full-color stereoscopic image by alternately activating two sets of LEDs and another set of LEDs is disclosed. The method of selecting the LED set is, for example, a first set of red LED sets, a blue LED set, a second set of green LED sets, or the like.
FIG. 4 shows a structural example of a liquid crystal display. This comprises a polarizing filter 1, a glass substrate 2, a transparent electrode 3, an alignment film 4, a liquid crystal 5, a spacer 6, a color filter 7, and a backlight.
FIG. 5 shows an example of transmission spectral characteristics of a resist used for a color filter of a color LCD panel. From this figure, it can be seen that although there is a slight overlap in the transmission characteristics, it can be spectrally separated by the color resist. It is desirable that the overlap of the transmission characteristics is as small as possible.
FIG. 6 shows a spectrum example of a light emitting diode (LED) light source used in a liquid crystal display. FIG. 7 shows a spectrum example of a white LED element using a blue LED, a green phosphor, and a red phosphor. As will be described later, the spectrum of the light source used in the present invention has various backlights, that is, in the case of the edge light type backlight method and the direct type backlight method, red (R), green (G), It is desirable that the boundary between blue (B) is clear. It is desirable to be clear in this way when a plasma display or a colored organic EL display is applied to the present invention.

US Patent Application Publication No. 2009/0085912

The present invention is a display device having a set of display primary colors (for example, three primary colors or four primary colors), that is, a normal color display device, and a normal refresh without using a particularly high refresh rate for stereoscopic images. A rate display device realizes an anaglyph type color stereoscopic image display device.

The stereoscopic image display device of the present invention is a stereoscopic image display device based on time-division multiplex anaglyph, which is a time-division multiplex image display means, a time-division multiplex image separation means, a first control device that controls the stereoscopic image display device, A second control device for controlling the time-division multiplexed image display means; and a synchronization means for synchronizing the first control device and the second control device. Further, the time-division multiplex image display means displays, on one display screen, a plurality of color stereoscopic images including at least one image of red, green and blue to be displayed for one of the right-eye image and the left-eye image. The right-eye image and the left-eye image are displayed simultaneously so that they are complementary colors, and the left-eye image and the right-eye image are alternately displayed by time-division multiplexing. To do. The time-division multiplex image separation means includes a right-eye and a left-eye, each of which is a color filter whose transmission wavelength characteristic changes periodically, and is a feature of the stereoscopic image display device. The transmission wavelength changes in synchronization with time-division multiplexing, and the transmission wavelength of the color filter for the right eye or the left eye is different from that of the color of the image displayed for the right eye or the left eye, respectively. It is characterized by being higher than the transmittance.
The stereoscopic image display device can be easily realized by using a liquid crystal panel for color image display on the display surface.
Further, the backlight of the color image display liquid crystal panel can easily separate red, green and blue by using a set of light emitting diodes or diode lasers emitting the red, green and blue light as light sources. In this case, as a matter of course, the time-division multiplex image display means selectively transmits red, green and blue light from the light source.
The time-division multiplex image display means is provided with each material that selectively transmits the red, green, and blue light in a mosaic pattern, such as a liquid crystal panel that excludes a backlight from a color liquid crystal display. In addition, each intensity modulation element that modulates the intensity of each light transmitted through each of the substances arranged in the mosaic pattern with each liquid crystal shutter is provided.
The time-division multiplexing display on the display screen has a configuration that can reduce flicker at a low refresh rate most, and the first image that displays the green image of the right-eye image, the red image, and the blue image of the left-eye image. Time division multiplexing is performed in which the period and the second period in which the red image, the blue image, and the green image of the left eye image are displayed are alternately arranged.
In synchronization with the first period, the green light transmittance of the green image of the right-eye or left-eye color filter is greater than the red light transmittance of the red image and the blue light transmittance of the blue image of the left-eye image. The green light transmittance of the green image of the right-eye or left-eye color filter is higher or lower than the second period, respectively, and the red light or blue image of the red image of the left-eye image is synchronized with the second period. Lower or higher than the blue light transmittance, respectively.
Each time slot in the time division is further time divided (hereinafter referred to as second time division), and the color filter is divided into a plurality of regions that change according to each time slot in the second time division, and the time division multiplexed image display is performed. The means is configured to be divided into a plurality of areas that perform respective displays that pass through each of the plurality of areas, and the plurality of areas change according to each time slot in the second time division,
The viewing angle can be increased by sequentially switching the divided area of the color filter and the divided area of the time-division multiplexed image display means according to each time slot in the second time division.

According to the present invention, for example, a time-division color anaglyph stereoscopic image displayed on a normal color liquid crystal display device is viewed through the time-division color filter glasses which is one of the features of the present invention, so that flicker can be achieved even at a normal refresh rate. Appreciate color 3D images without feeling.

FIG. 1 shows a block diagram of a stereoscopic image display apparatus of the present invention.
FIG. 2 shows an operation timing diagram of the example of FIG.
FIG. 3 is an operation timing chart in the case where the transmission characteristics of the liquid crystal panel 11 and the color filter 13 are synchronized, and is an example of a time chart slightly different from FIG.
FIG. 4 is a diagram showing the structure of the liquid crystal display 10. This is a structure that can also be used for the color filter 13.
FIG. 5 shows an example of the transmission spectrum of the color filter of the liquid crystal display 10.
FIG. 6 is a schematic diagram showing an emission spectrum of a backlight using LEDs as light sources for all three primary colors.
FIG. 7 is a schematic diagram showing an emission spectrum of a backlight of a white LED light source using a blue LED, a green phosphor, and a red phosphor.
FIG. 8 is a diagram illustrating that when there is an overlapping portion of the transmission characteristics at the RGB ends of the color filter 13, a ghost image due to light transmitted through the portion may be seen. In order to avoid this, it is desirable to use a color filter in which the overlap between BG and GR is negligible in the spectral characteristics of transmittance.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the following description, devices having the same function or similar functions are denoted by the same reference numerals unless there is a special reason.

FIG. 1 is a block diagram of a stereoscopic image display apparatus as an example of the present invention. FIG. 2 shows an example of the operation timing. The stereoscopic image display apparatus of the present invention is a stereoscopic image display apparatus based on time-division multiplex anaglyph, which is time-division multiplex image display means (liquid crystal display 10), time-division multiplex image separation means (color filter glasses 12), and the stereoscopic image. A first control device 16 for controlling the display device, a second control device 15 for controlling the time-division multiplexed image display means, and a synchronizing means (synchronizing circuit 18) for synchronizing the first control device and the second control device It comprises. The synchronization circuit 18 may be wired or wireless. The liquid crystal display 10 modulates light including red (R), green (G), and blue (B) of the three primary colors of light from the backlight 17 with an image displayed in color on the liquid crystal display panel 11, and the observer 14 Is observed through the left and right color filters 13. The image displayed on the liquid crystal display panel 13 is the output of the first control device 16, and the liquid crystal display panel 13 constituting the color filter glasses 12 is controlled by the second control device 16.
The backlight used here is, for example, a well-known cold cathode fluorescent tube. In addition, a light source having a spectrum shown in the schematic diagram of FIG. 6 may be used in which the three primary colors are LEDs or laser diodes. Further, the light source having a spectrum shown in the schematic diagram of FIG. 7 may be a white LED light source using a blue LED, a green phosphor, and a red phosphor.
The liquid crystal display 10 has, for example, the structure shown in FIG. The transmission spectrum of the color filter can be used even when there is a slight overlap between the red and green or green and blue spectra as shown in FIG. 5, but this overlap is preferably as small as possible. In addition, if there is no overlap between the red, green and blue emission spectra of the backlight, the spectrum of the product of the emission spectrum and the transmission spectrum can be easily separated, so the overlap between the red, green and blue transmission spectra of the color filter is ignored. It becomes a possible problem.
The color filter glasses 12 are glasses having a structure similar to that of the liquid crystal display of FIG. 4 and are prepared for the right eye and the left eye. In this case, the transmission characteristics of the color filter 13 allow viewing of a color stereoscopic image even when the transmission characteristics of the color filter of the liquid crystal display 10 are similar to those described above. However, the transmission characteristics at the RGB edges of the color filter 13 overlap. When there is a part, a ghost image by light transmitted through the part may be seen. In order to avoid this, as shown in FIG. 8, it is desirable to use a color filter that is small enough that the overlap between BG and GR is negligible in the spectral characteristics of transmittance. When such a color filter is not used, a dielectric multilayer film filter is provided on the glass substrate of the color filter glasses 12 so as to block light transmission between the BG and the G-R overlapping portions. You may make it do.
As shown in FIG. 2, the image displayed on the liquid crystal display 10 and the transmission characteristics of the color filter 13 are synchronized as follows. This synchronization is achieved between the first control device 16 and the second control device 15 via the synchronization circuit 18.
(1) In t1 section,
On the right side of the LCD panel 11, green is transmitted, red and blue are blocked,
On the left, green is blocked, red and blue are transmitted,
On the right side of the color filter 13, green is transmitted, red and blue are blocked,
On the left, green is blocked, red and blue are transmitted,
(2) In t2 section,
On the right side of the LCD panel 11, green is cut off, red and blue are transmitted,
On the left, green is transmitted, red and blue are blocked,
On the right side of the color filter 13, the green is blocked, the red and blue are transmitted,
On the left, green is transmitted, red and blue are blocked,
And repeat these intervals.

The image displayed on the liquid crystal display 10 and the transmission characteristics of the color filter 13 may be synchronized as shown in FIG.
(1) In t1 section,
On the right side of the LCD panel 11, green and blue are transmitted and red is blocked.
On the left, green and blue are blocked, red is transmitted,
On the right side of the color filter 13, green and blue are transmitted, red is blocked,
On the left, green and blue are blocked, red is transmitted,
(2) In t2 section,
On the right side of the LCD panel 11, green and blue are blocked, red is transmitted,
On the left, green and blue are transmitted, red is blocked,
On the right side of the color filter 13, green and blue are blocked, red is transmitted,
On the left, green and blue are transmitted, red is blocked,
And repeat these intervals.
Although the present invention has been described with reference to specific illustrative embodiments, various changes and modifications may be made to the above-described embodiments without departing from the technical scope of the present invention as defined in the claims. What can be done is obvious to those skilled in the field to which the present invention belongs.

The above description is for the three primary colors, but in the case of the four primary colors, the following may be used. Here, yellow (Y) is used in addition to the above RGB.
For example, in the case of the first embodiment, a light source containing yellow (Y) is used, and the color filter and the color filter 13 of the liquid crystal display panel 11 are yellow (Y) in addition to RGB. Moreover, what is necessary is just to synchronize with the green thing as the timing of permeation | transmission and interruption | blocking, for example.

DESCRIPTION OF SYMBOLS 1 Polarizing filter 2 Glass substrate 3 Transparent electrode 4 Alignment film 5 Liquid crystal 6 Spacer 7 Color filter 10 Liquid crystal display 11 Liquid crystal display panel 12 Color filter glasses 13 Color filter 14 Observer 15 Second controller 16 First controller 17 Backlight 18 Synchronous circuit

Claims

A stereoscopic image display device using time-division multiplexed anaglyph, which controls time-division multiplexed image display means, time-division multiplexed image separation means, a first control device for controlling the stereoscopic image display device, and the time-division multiplexed image display means. A second control device, and synchronization means for synchronizing between the first control device and the second control device,
The time-division multiplex image display means displays a plurality of color stereoscopic images including at least one image of red, green and blue to be displayed on one display screen for either one of the right-eye image and the left-eye image. It is displayed with division multiplexing.
The image for the right eye and the image for the left eye are displayed at the same time so as to be different color images,
The left-eye image and the right-eye image are alternately displayed in time division multiplexing,
The time-division multiplexed image separation means includes a right-eye type and a left-eye type, each of which is a color filter whose transmission wavelength changes periodically, and is a time-division multiplexing of the stereoscopic image display device. The transmission wavelength of the color filter for the right eye or the left eye changes in synchronization with the transmission wavelength of the color of the image displayed for the right eye or the left eye, respectively. A stereoscopic image display device characterized by being higher than that.
The stereoscopic image display device according to claim 1, wherein the stereoscopic image display device uses a liquid crystal panel for color image display as a display surface.
The backlight of the liquid crystal panel for color image display uses a light emitting diode or a diode laser that emits each of the red, green, and blue light as a light source,
3. The stereoscopic image display device according to claim 1, wherein the time-division multiplex image display means selectively transmits each of red, green, and blue light from the light source. .
The time-division multiplex image display means is provided with each material that selectively transmits the red, green, and blue light in a mosaic shape, and each light that transmits each material arranged in the mosaic shape. 4. The stereoscopic image display device according to claim 1, comprising each intensity modulation element that modulates the intensity with each liquid crystal shutter. 5.
The time division multiplex display on the above display screen is
A first period for displaying a green image for the right eye image, a red image and a blue image for the left eye image,
A second period of displaying a red image and a blue image of the right-eye image and a green image of the left-eye image;
The three-dimensional image display device according to any one of claims 1 to 4, wherein are arranged alternately.
In synchronization with the first period,
The transmittance of green light of the green image of the color filter for the right eye is higher than the transmittance of red light of the red image of the left eye image and blue light of the blue image,
In synchronization with the second period,
The transmittance of green light of the green image of the color filter for the right eye is lower than the transmittance of red light of the red image of the left eye image or blue light of the blue image,
The stereoscopic image display device according to claim 5, wherein
In synchronization with the first period,
The transmittance of green light of the green image of the color filter for the left eye is lower than the transmittance of red light of the red image of the left eye image and blue light of the blue image,
In synchronization with the second period,
The transmittance of the green light of the green image of the color filter for the left eye is higher than the transmittance of the red light of the red image of the left eye image or the blue light of the blue image,
The stereoscopic image display device according to claim 5, wherein