JPH10150676A - Image display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To accurately detect the position of an eye even in small-scale constitution by using displayed control image for a right eye and control image for a left eye and supplying directions respectively toward the right eye and left eye of an observer to first and second images. SOLUTION: The image 130 of a face is expressed by the set of dots provided with the value of '1' for instance and the set of the dots is expressed as a dot line along plural scanning lines. On the respective scanning lines, a point at the center position of the dot set provided with the value of '1' is detected and the set of the positions of the center points constitutes a straight line or a curve 131. Then, the image 130 is divided with the straight line or the curve 131 as a boundary and a backlight control image 140R for the right eye and the backlight control image 140L for the left eye are obtained. The backlight control image 140R for the right eye is displayed at a display device for the right eye, the backlight control image 140L for the left eye is displayed at the display device for the left eye and the respective display devices are set so as to make picture elements provided with the value of '1' emit light.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a three-dimensional image display apparatus of the type in which a backlight for illuminating an image display means has directivity to select left and right images.

[0002]

2. Description of the Related Art In recent years, the probability of a technique for displaying a stereoscopic image in various fields has been required. For example, in the medical field, in which the technology for observing the cross section of an examination site using MRI, CT, or the like has been advanced, it is desired to establish a technique for stereoscopically observing the examination site for the purpose of improving diagnostic accuracy. I have. Also, in the field of arts and crafts, it is desired to establish a technique for displaying a three-dimensional stereoscopic image from a two-dimensional image depicting arts and crafts.

Up to now, image information drawn on a plane has been
As means for three-dimensionally viewing the image, a holographic image reproduction technique, a lenticular method, a time-division eyeglass method, and the like are known. However, there is a problem that a great deal of labor is required to create a hologram, a device for reproducing a hologram three-dimensional image is complicated, and the cost is high. Further, in the lenticular method, the range of the position of the observer in which stereoscopic vision is possible is narrow, and there is a problem that the image is deteriorated when the observer moves.
Further, the time-division glasses method has a problem that glasses are indispensable at the time of observation.

[0004] A stereoscopic image display device that solves such a problem, that is, a stereoscopic image display device that is a simple device but has a wide stereoscopic viewable range or does not require glasses, is a liquid crystal display device. 2. Description of the Related Art There is known a system in which a right and left image is selected by displaying the image on a display and providing the backlight for the liquid crystal display with directivity. See, for example, JP-A-7-140418 by the applicant of the present application.

This device has a configuration as shown in the example of FIG. In the example of FIG. 1, a monochrome liquid crystal display device 103 is provided as a light source that emits a backlight, and for convenience, a display device (a light transmission type display device such as a liquid crystal display device or a film) that displays a stereoscopic image is provided. Illustration is omitted.
In FIG. 1, an illuminating device 101 having an LED that emits light having a known wavelength (for example, infrared light) is disposed, for example, on the right side of the observer 100, and only the right half of the face of the observer 100 is viewed from the side. Try to illuminate. Then, observer 10
The face 0 is brightly lit only on the right half. This face image is photographed by the CCD camera 102. The obtained image data of the face is binarized, and then inverted upside down and displayed on the display screen of the liquid crystal display device 103. Camera 1
Numeral 02 is arranged to photograph the front of the face of the observer 100. Therefore, in the face image of the observer displayed on the display device 103, the right part of the observer's face is in the left area 104 of the display screen, the left part of the observer's face is in the right area 107 of the display screen, The lower part of the observer's face is displayed in the upper area of the display screen, and the upper part of the observer's face is displayed in the lower area of the display screen.

[0006] A convex lens 106 is arranged on the front surface of the monochrome display device 103. This convex lens 106
Is a face image displayed on the display device 103, and a display device screen 103 reflected on the observer's eyes via the convex lens 106.
It is adjusted so that the upper face image is substantially overlapped geometrically.
That is, the position of the optical axis and the position of the focal point of the convex lens 106 are adjusted. When the convex lens 106 is adjusted in this manner, the face image displayed on the display device screen 103 functions as illumination with a large lens diameter for the right eye of the observer. And
A light transmission type image display device (not shown in FIG. 1) such as a liquid crystal display is arranged on the front surface of the convex lens 106, and when an image for the right eye is displayed on the display device,
Light from the region where the image of the right half of the observer is displayed on the screen of the display device 103 functions as a backlight of the display device. Further, since the light from the above-mentioned region is given directivity by the convex lens 106, it does not reach the left eye of the observer, that is, does not function as a backlight for the left eye of the observer.

On the other hand, the left half of the observer's face is
01, the area of the screen of the display device 103 on which the left half image is displayed does not emit light, and thus this area functions as a backlight for the observer's left eye. I will not do it. Although FIG. 1 shows a system configuration for displaying the image for the right eye only on the right eye of the observer, in order to display the image for the left eye only on the left eye of the observer, a left half of the observer face is separately provided. It is sufficient to provide an illuminating device for illuminating, a camera for selectively photographing the left half thereof, and a monochrome liquid crystal display device for displaying an image of the left half thereof. FIG. 2 shows a configuration example for that purpose.

In FIG. 2, the left-eye lighting device 101L emits light having a wavelength different from the light emitted by the right-eye lighting device 101R. Further, the right-eye camera 102R is sensitive only to the wavelength of light of the right-eye illumination device 101R, and
2L is made to be sensitive only to the wavelength of light of the left eye illumination device 101L. Further, the half mirror 110 is used as a monochrome liquid crystal display device 103L as a backlight light source for the left eye.
Are arranged so as not to interfere with the liquid crystal display device 103R as the backlight light source for the right eye. Right eye liquid crystal display device 103R, left eye liquid crystal display device 103L, convex lens 106R, convex lens 106L, half mirror 110
The backlight from the right-eye liquid crystal display device 103R is focused so that the backlight from the right-eye liquid crystal display device 103R is condensed by the convex lens 106R, passes through the half mirror 110, and reaches the observer's right eye. The light is condensed by the convex lens 106L, is reflected by the half mirror 110, and is arranged so as to reach the left eye of the observer.

In this case, the left-eye backlight is turned left and right when reflected by the half mirror, so that the left-eye backlight image is displayed on the left-eye display device 10.
When displaying in 3L, it is necessary to display as a left-right inverted image by image processing or the like. Thus,
In the system of FIG. 2, the backlight for the left eye is incident only on the left eye, and the backlight for the right eye is incident only on the right eye, so that the observer's right eye is a transmission type display (not shown) installed near the convex lens 103R. The left eye sees only the target image for the left eye displayed on the transmission type display device (not shown) installed near the convex lens 103L. Here, since the two backlights displayed on the display devices 103R and 103L are images of the face of the observer, if the position of the observer moves, the images of those backlights are also displayed on the screen of the display device. As it moves, the system of FIG. 2 allows for a wide range of stereoscopic viewing.

[0010]

As described above, in the above-described conventional example, since the illumination of the observer is performed from the side, the illumination (101R, 101R) having different wavelengths on the left and right sides of the observer.
01L) is required independently of the main body of the stereoscopic image display device. In addition, for the CCD camera that shoots the observer,
One pair (1) having a filter function of selectively passing only one of the different wavelengths of the left and right illuminations respectively.
02R, 102L).

For this purpose, the conventional system shown in FIG.
Although it enables stereoscopic viewing in a wide range, the configuration of the device must be large. For the purpose of simplifying the device configuration of FIG. 2, only a single illumination device is arranged in front of the observer, and a stereoscopic image display system in which imaging for obtaining an image of the backlight is also performed by a single camera, This has been proposed by the applicants of the present application as Japanese Patent Application Laid-Open No. Hei 7-159723.

In this proposed system, the single camera takes an image of an observer with only one half illuminated,
The obtained observer image is inverted in the vertical direction and displayed on the display device as shown in FIG. In FIG.
Numeral 0 denotes a portion which is brightly illuminated by illumination and is used as a right-eye backlight. The left-eye backlight uses an image (for example, FIG. 4) generated by inverting the observer image of FIG. 3 from negative to positive.

However, in the above-mentioned proposed technique, since the illumination light is not emitted toward the front of the observer, there is a problem that the shape of the observer image is destroyed depending on the face position or posture of the observer. . That is, the observer image in FIG. 3 is obtained under the condition that the illumination light is properly applied to the half surface of the observer. Therefore, when the observer is positioned before or after the proper position, the positional relationship between the light irradiation direction and the observer is broken, and the shape of the observer image is broken because the illumination light is not properly applied. It will be. 3 or 4, a right half face image 120 used as a right eye backlight light source and a left half face image 12 used as a left eye backlight light source are shown.
For the boundary with 1, an ambiguous boundary portion between a portion where the observer's face is irradiated with the illumination light and a shadow portion is used.

In addition to these, individual differences between observers, such as the size of the face, the shape of the ears, and the shape of the hair of the observer, and the change in the size of the image due to the change in the observation position in the front-back direction of the observer,
This greatly affects the position and size of the boundary, causing a problem.

[0015]

SUMMARY OF THE INVENTION The present invention has been made in view of such a situation, and an image which can accurately detect a face position of an observer, particularly an eye position, even in a small-scale configuration. The image display device of the present invention for this purpose, which proposes a display device, detects an area on the face of the observer as a position of both eyes in a pseudo manner, and a first different from the eyes of the observer. An image display device for observing the image of the observer and a second image, respectively, based on a means for imaging the face of the observer, and image data of the face of the observer obtained by the imaging means. Detecting means for detecting a substantially center position in the horizontal direction, generating means for generating a right-eye control image and a left-eye control image based on the detected substantially center position of the face image, and the right-eye control image; Display control image for left eye Directivity giving the directivity toward the right and left eyes of the observer to the first image and the second image, respectively, using the display means and the displayed right-eye control image and left-eye control image. Means.

The detecting means can estimate the center position of the face from one face image even if the number of the imaging means is one. According to a preferred aspect of the present invention, the first image and the second image are each a stereoscopic image captured with a predetermined parallax. According to a preferred aspect of the present invention, the face center position is estimated from the binarized image data of the face image.

According to a preferred aspect of the present invention, the center position is detected by scanning the image data of the face image in the horizontal direction. According to a preferred aspect of the present invention, the position of the contour of the face in the image data is identified by detecting the position where the value of the image data of the face image greatly changes. According to a preferred aspect of the present invention, a center position between two points in the horizontal direction on the detected contour of the face is identified as a substantially center position of the face.

According to a preferred aspect of the present invention, the detecting means includes means for scanning the face image in a vertical direction, and detects a center position in a horizontal direction at a plurality of points in a vertical direction. I do. According to a preferred aspect of the present invention, the directivity providing means has a convex lens or a Fresnel lens.

According to a preferred aspect of the present invention, the convex lens or the Fresnel lens is configured in an array. According to a preferred aspect of the present invention, the display unit emits light at a position where dots of the control image are output, so that the light of the control image functions as a backlight.

According to a preferred aspect of the present invention, the first
A display device for displaying the image of the second and the second image,
The display means is arranged in front of the display device and is a monochrome liquid crystal display device that transmits light, so that the control image displayed on the display means functions as a parallax barrier. According to a preferred aspect of the present invention,
The display means has a set of liquid crystal display devices arranged at right angles to each other, and the directivity providing means has a half mirror arranged in front of the set of liquid crystal display devices. I do. By having the half mirror, the first image and the second image are combined and appear to the observer's eyes.

A display device according to a preferred embodiment of the present invention includes:
A display device capable of displaying the first image and the second image in a time-division manner, wherein the display unit of the display device includes the first image and the second image on the display device; The control image for the right eye and the control image for the left eye can be displayed in a time-division manner in synchronization with the switching timing. Thereby, the number of display means can be reduced to one.

A display device according to a preferred embodiment of the present invention includes:
A display device in which a first area for displaying the first image and a second area for displaying the second image are further arranged substantially uniformly on one display surface; When displaying the control image for the right eye and the control image for the left eye with first and second polarizations different from each other, the display device may be configured such that the first region reflects the first polarization. The second region is substantially transmitted as write light and substantially blocks the second polarized light, and the second region substantially transmits the second polarized light as backlight light and substantially transmits the first polarized light. It is characterized by being configured to shut off.

According to a preferred aspect of the present invention, the imaging means has only one camera. According to a preferred aspect of the present invention, the imaging means has one or more lighting devices. According to a preferred aspect of the present invention, the imaging means is arranged substantially at the center in front of the observer. Observer images can be obtained more symmetrically.

[0024]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a three-dimensional image display device according to a preferred embodiment to which the present invention is applied will be described. <Principle of Control Image Generation> FIGS. 5 and 6 show an image for generating a right-eye backlight (hereinafter referred to as a “right-eye backlight control image”) applied to the preferred embodiment of the present invention. ) And an image for generating a left-eye backlight (hereinafter, “left-eye backlight control image”) will be described based on the principle of being generated from one face image.

In FIGS. 5 and 6, for convenience of explanation,
The face image is drawn without being turned upside down. In FIG. 5, 130 is an image of the face of the observer obtained from one camera. It is assumed that the face image 130 is represented by a set of dots having a value of “1”, for example. These dot sets correspond to a plurality of scanning lines (132-1 to 132-1).
32-n). In each scanning line, a point located at the center of a dot set having a value of “1” is detected, and the set (131-1, 131-2 to 131-n) of the positions of these center points is represented by a straight line or a curve. 131. In other words, extracting this straight line or curve 131 means recognizing a straight line or curve passing through the center position of the face image.

Thus, as shown in FIG. 6, the image 130 can be divided by a straight line or a curve 131 to obtain a right-eye backlight control image 140R and a left-eye backlight control image 140L. Then, the right-eye backlight control image 140R is displayed on the right-eye display device as shown in FIG. 7, and the left-eye backlight control image 14L is displayed on the left-eye display device as shown in FIG. If the pixel is set to emit light with the dot data having a value of “1”, the image of FIG. 7 functions as a right-eye backlight, and the image of FIG. 8 functions as a left-eye backlight.

The technique described with reference to FIG. 5 uses one camera (or at least one camera) and at least one camera.
This is effective in that a set of backlight control images can be obtained very easily from one lighting device (or one lighting device). FIG. 9 illustrates the generation of a backlight control image in the case where the contour of the obtained observer's face image is asymmetric.

FIG. 9 shows an image 150 of the face when the shape of the face of the observer is different between the left and right depending on the hairstyle or the like.
Applying the method described in connection with FIG. 5 to this image,
The center line 151 in FIG. 9 is obtained. In the example of FIG.
The center line 151 has a large bend unlike the center line 131 (FIG. 5) because there is a deformation between the left and right. As described above, when the face image is imbalanced between the left and right, the positions of the left and right pupils are shifted left or right from the center position of the image. The face image obtained by applying the method of FIG.
1 (actually a curve) to generate two backlight control images, the effect of deformation is reduced by half, and one backlight for the right eye or left eye enters the pupil of the other eye. The possibility of occurrence of crosstalk of light is reduced.

FIG. 10 illustrates the principle of detecting the center point of an image. That is, in FIG. 10, it is assumed that the face images (172 to 174) of three observers are obtained in the image 170 obtained from the camera. When the image 170 is scanned along a certain scanning line 171, a signal of a graph like 18 is obtained. HSYNC shown in the graph 180 is a horizontal synchronization signal of the scanning line. The position of an arbitrary dot is represented by the elapsed time t from the time of occurrence of HSYNC until the dot is detected. In the example of FIG. 10, the right end dot of the viewer A is found at time t _1. Accordingly, the center position of the face image of the observer A are generated duration of the dots on the scan line 171 When t _2, a t ₁ + t _2/2. The central position of the face image of the observer C is the time of occurrence of dots on the scan line 171 for observer C and t _3, the generation duration of the dots and t _4, and t ₃ + t _4/2 Become.

When an actual face is photographed, the illuminance differs depending on the position of the face, so that a discontinuous area may be generated in the face image. In preparation for such a case, it is desirable to use a known labeling method in order to easily recognize that a plurality of discontinuous dot areas are one face. Further, the method of generating a backlight graphic according to the present invention can be applied to a so-called parallax barrier method in displaying a stereoscopic image. Therefore, in this specification, a control image used for the backlight method is called a “backlight control image”, and a control image used for the parallax barrier method is called a “transmitted light control image”.

<Stereoscopic Image Display System> First Embodiment Hereinafter, a system in which a backlight control image generated according to the principle described with reference to FIGS. 5 to 10 is applied to stereoscopic image display will be described. FIG. 11 shows a configuration of a stereoscopic image display system having a half mirror to which the principle of the present invention described with reference to FIGS.

This system includes a color camera 200R for obtaining a parallax image for right-eye observation, a color camera 200L for obtaining a parallax image for left-eye observation, a right-eye image and a left-eye image taken by these cameras. Color liquid crystal display panels 204R and 204L for displaying images, respectively;
A lighting device 201R for providing illumination to the observer's face,
201L and a monochrome CCD camera 20 for obtaining an image of the observer's face illuminated by these illumination devices.
2, an image processing device 211 for generating a right-eye backlight control image and a left-eye backlight control image based on the observer's face image captured by the camera 202;
And monochrome display devices 203R and 203L that respectively display the right-eye backlight control image and the left-eye backlight control image generated by the display device 11, and are arranged closer to the observer than the monochrome liquid crystal display devices 203R and 203L. Two convex lenses 205R and 205L for selectively distributing the backlight from the devices 203R and 203L to the left and right eyes of the observer, and a color liquid crystal panel 204R.
And a half mirror 210 for displaying two parallax images for observation (for the right eye and for the left eye) displayed at 204L.

The illuminating devices 201R and 201L illuminate the observer with infrared rays so that the observer does not feel dazzling when illuminating the observer's face from the front. The camera 202 is the lighting device 2
01R and 201L have sensitivity to the infrared rays emitted.
Note that only one lighting device may be provided at the center. Each of the convex lenses 205R and 205L and the monochrome liquid crystal display 2
The distance between each of the surfaces 03R and 203L is set to a value at which an observer image can be focused on the surface of the monochrome liquid crystal display (203R, 203L) by the convex lens (205R, 205L) or a value close to the value. Is set to

The right-eye backlight control image on the monochrome liquid crystal display 203R functions as a large-diameter backlight for only the right eye of the observer due to the convex lens 205R, and the backlight control image for the left eye is the left-eye backlight control image. Only functions as a backlight with a large lens diameter. Thereby, the observer can see the color display panel (204R,
204L) can be stereoscopically viewed. In order to make the backlight control image function as a backlight, it is necessary to adjust the size and position of the face image on the liquid crystal surface of the monochrome liquid crystal display (205R, 205L) in advance.

FIG. 12 shows the configuration of the image processing device 211 for generating the right-eye and left-eye backlight control images.
The image processing 211 includes a binarization circuit 250 for binarizing a luminance component in a video signal from the camera 202,
02 based on the synchronization signal SYNC from the H.02.
A synchronization signal generation circuit 254 for generating a SYNC, a leading edge detection circuit 251 for detecting a leading edge (that is, a pixel having a value of “1” appearing first after “0”) in the image signal, And a trailing edge detecting circuit 253 for detecting a trailing edge (i.e., a pixel having a value of "0" that first appears after detecting a dot of "1"). A middle point detection circuit 252 for finding the middle point of the dot set having a value of “1” (ie, the center position of the face of the observer), and a backlight control image for the right eye and a left eye And a video signal synthesizing circuit 255 for generating a backlight control image.

The threshold used for the binarization processing of the observer image by the binarization circuit has hysteresis so that noise such as mosquito noise does not appear on the boundary between the observer and the background. be able to. Further, the noise may be reduced by lowering the spatial frequency of the captured image by setting the adjustment of the camera that captures the observer to the defocus limit.

The leading edge detection circuit 251 and the trailing edge detection circuit 253 can be configured using various elements. For example, as shown in FIG. 13, it can be configured using a counter, a latch, and the like. That is, the leading edge detection circuit 251 and the trailing edge detection circuit 253 of FIG.
4 and a circuit 261 for generating a clock capable of dividing the video signal of one line so as to secure a sufficient resolution.
And a circuit 260 for detecting a trailing edge of the horizontal synchronization signal HSYNC. HSY by circuit 260
When NC is detected, the counter 264 is reset,
Thereafter, the output of the detection circuit 260 goes high, so that the counter 264 can count the number of clocks from the clock generator 261. That is, the output of the counter 264 counts the number of clocks after detecting HSYNC. The circuit 262 detects a predetermined number or more consecutive “1” s in the image signal. Similarly, the circuit 263 detects the first consecutive “0” of a predetermined number or more in the image signal. When the detection circuit 262 detects the first “1”, the latch 265 stores the output of the counter 264. Also,
Latch 266 stores the contents of counter 264 in response to detection circuit 263 detecting the first “0” after “1”.

That is, the latch 265 is for t ₁ or t ₃ in FIG. 10, and the latch 266 is for t ₁ + t ₂ or t ₃ + t in FIG.
Remember ₄ These mean the time required to detect a leading edge from HSYNC (horizontal synchronization signal) (leading edge detection time) and the time required to detect a trailing edge from HSYNC (trailing edge detection time).

The midpoint detection circuit 252 in FIG. 12 uses a clock generation circuit equivalent to the clock used in the two detection circuits (251, 253) and sets each leading edge of the binarized luminance signal as a reset timing. A counter for counting the number of clocks from the clock generation circuit,
It is constituted by digital means such as a plurality of storage elements (for example, latches) for storing the counting result of the counter each time in synchronization with the trailing edge paired with each of the leading edges. Here, the middle point between each leading edge and the trailing edge that is paired with the leading edge drops the least significant bit of binary data stored as the counting result of the counter (or shifts all bits to lower bits). Do) can be easily obtained.

The video signal synthesizing circuit 255 generates the backlight control graphic described with reference to FIG. 6 or FIG. 10 based on the stored values stored by the three detection circuits (251 to 253). The leading edge detection time and the trailing edge detection time are obtained by comparing the stored values of the two detection times and the count result of the counter that counts the clock starting from HSYNC 1 H after the storage time with the input for comparison. As the output of the digital comparator.
Also, the time at the midpoint of both detection times, that is, the midpoint detection time is
The stored value of the middle point and the count result of the counter whose reset timing is the leading edge detection time reproduced as the output of the comparator are obtained as an output of a digital comparator which is an input for comparison.

From the leading edge detection time and the midpoint detection time thus obtained, a binarized signal is generated, which is a new leading edge and a trailing edge, respectively, and is synthesized with the synchronization signal. In this way, a backlight control image for fabric can be obtained. Similarly, based on the obtained midpoint detection time and trailing edge detection time, a binarized signal having these as a leading edge and a trailing edge is generated, and the binarized signal is combined with a synchronization signal. By doing so, a left-eye backlight control image is obtained.

FIG. 14 shows two optical paths reaching the eyes of the observer in the system of the first embodiment. FIG.
Shows a process in which the parallax image for right-eye observation displayed on the color liquid crystal display panel 204R is transmitted by the half mirror 210 to the right eye while being illuminated by the backlight control graphic displayed on the monochrome liquid crystal display device 203R. Also, FIG. 16 shows that the parallax image for left eye observation displayed on the color liquid crystal display panel 204L is inverted by the mirror 210 while being illuminated by the backlight control graphic displayed on the monochrome liquid crystal display device 203L, and reaches the left eye of the observer. FIG.

The backlight control graphic needs to be inverted in both the monochrome liquid crystal display devices 203R and 203L in order to ensure the followability of the observer in the vertical movement. Also, as shown in FIGS. 14 and 16, the parallax image for left-eye observation displayed on the color liquid crystal display panel 204L is inverted by the mirror 210, so that the parallax image for left-eye observation must be inverted in the depth direction in advance. There is. Note that the parallax image for the right eye observation only passes through the mirror 210, and thus does not need to be turned upside down. These processes may be performed by image processing, but may be simply set so that the liquid crystal panel is turned upside down, upside down, or the like.

The monochrome liquid crystal display device 203R (20
3L), an output side polarizing plate, and a color liquid crystal panel 204R.
The (204L) incident-side polarizing plate must always have the same polarization axis. <Modification of First Embodiment> A modification of the first embodiment will be described below.

The image processing device 211 can also be constituted by an analog circuit. For example, the latch (2
65, 266) is a capacitor that stores time as a terminal-to-terminal potential, a counter (264) is a constant current circuit that charges and discharges the capacitor with a constant current, and a digital comparator uses a potential before charging the capacitor as a threshold. It can be replaced with a working analog comparator circuit.

In order to measure and store the leading edge detection time and the trailing edge detection time, charging of the capacitor is started from HSYNC, and is ended at the leading edge and the trailing edge of the binarized signal.
The potential between the terminals of the capacitor at this time is proportional to the charging time, that is, both detection times. Further, reading of the storage amount is performed by discharging the charge charged at the time of storage from the HSYNC after 1H, and a desired time is obtained as an output of a comparator having the potential between the capacitor terminals and the potential before charging as a comparison input. Can be. In the midpoint detection circuit, charging of the capacitor starts at the leading edge of the binarized luminance signal and ends at the trailing edge that is paired with the leading edge. Here, at the middle point between the desired two edges, the charge charged during storage is discharged from the leading edge detection time obtained as the analog comparator output, and the potential between the capacitor terminals and the pre-charge potential are used as comparison inputs. A desired time can be obtained as the output of the comparator. However, the discharge current value at that time is set to be twice that during charging. Alternatively, charge the discharge current value by halving the waste between terminals by connecting in parallel a capacitor of the same capacity that does not accumulate charge on the capacitor after charging, and then disconnecting the connected capacitor again and starting discharge. It can be the same as time. Also, from the beginning, two capacitors of the same capacity are used in series, and after charging, the midpoint potential is stored in another capacitor via a buffer, and this is stored in a different capacitor instead of the pre-charge potential. , The discharge current value can be made the same as during charging.

The image processing device 211 can have another configuration even when a configuration using a digital circuit is used. For example, the midpoint detection circuit 252 is configured by an adder and a shift circuit (not shown). After adding the leading edge detection time stored in the latch 265 and the trailing edge detection time stored in the latch 266, the half value of the addition result is calculated. , The detection time of the midpoint between the two edges with HSYNC as the reset timing may be obtained.
The half value can be obtained by 1-bit shift of the addition result represented by the binary data in the same manner as the above procedure. This configuration can also be applied to a configuration using an analog circuit.

Further, the three detection circuits (2
51 to 253) have storage elements for two lines, and when one is in a writing state, the other is in a reading state, and processing is performed for each line by alternately switching its capability. In this processing method, the display of each line is shifted downward by one line. However, by using the 1H delay synchronization signal generation circuit 254, the synchronization signal portions VSYNC and HSYNC are also sent by 1H. The display position at the time of displaying on the drawing can be the same. Of course, the display position may be corrected by performing the processing for one frame at a time.

As a further modification, all processing in the image processing device 211 can be performed by software. If the position of the observer is within a certain range, stereoscopic viewing using the above device is possible, so that a plurality of observers can simultaneously recognize the same stereoscopic image. First
A modification of the embodiment will be further proposed.

For example, the above-described convex lens 205 is the same as that shown in FIG.
By using the convex lens array 251 as shown in FIG. 7, it is possible to shorten the focal length and reduce the size. In FIG. 17, a plurality of convex lens units 252 are arranged at equal intervals in the left, right, up, and down directions. Also, the convex lens 205
The lens unit 252 may use a Fresnel lens.

However, when a convex lens or a Fresnel lens is arrayed, the monochrome liquid crystal display device 203R,
The optical image displayed on 203L must be formed for each unit corresponding to the lens unit 252f forming the array, as shown in FIG. In the example of FIG.
A Fresnel lens is used as a unit of the lens array. As shown in FIG. 18, the display screen of the monochrome display device 203 has a plurality of areas (203-1, 203-2, 203-203).
3,...), And the reduced backlight control graphic is displayed in each area. In this case, the number and shape of the lens units 252f are arbitrary.

In the embodiment, it is preferable to photograph the face of the observer from the front. For this purpose, a half mirror (not shown) is provided in front of the observer, and light from the face is reflected by this mirror. Then, the reflected light is captured by a camera with the optical axis directed upward. In this way, the observer's face can be captured from the front. Light from the display device passes through the mirror.

Further, the illuminating light source is not limited to an infrared light source, but may be a visible light or an ultraviolet light as long as it has a wavelength range in which the camera has sensitivity. Furthermore, when performing predetermined image processing, by using a system that can obtain those images instead of the camera,
It is also possible to use microwaves or ultrasonic waves as a medium.

In this embodiment, a black-and-white liquid crystal display is used as a backlight light source.
For example, a plasma display, a liquid crystal projector, a neon tube display, a solid state light emitting device, a thin CRT, an array CRT, or the like can be used. Further, it is of course possible to use various light sources other than the display as the light source for the backlight.

<Stereoscopic Image Display System> Second Embodiment In the first embodiment, the right-eye parallax image and the left-eye parallax image reflected on each of the two color liquid crystal display panels (204R, 204L) are half mirrored. The images are synthesized at 210 and coexist in the same visual field. That is, the display system of the first embodiment includes a set of monochrome liquid crystal display devices for displaying a set of backlight control images for the left and right eyes,
A set of color liquid crystal panels for displaying a set of parallax images for observation for the left and right eyes is required.

The stereoscopic image display system according to the second embodiment comprises:
One set of backlight control images is displayed on one monochrome liquid crystal display device, and both the parallax image for the right eye and the parallax image for the left eye are displayed on one color liquid crystal panel, thereby reducing the configuration of the entire system. It is characterized by. FIG.
Shows the configuration of the stereoscopic image display system according to the second embodiment. In the figure, the system includes a monochrome liquid crystal display device 300 from which a polarizing filter on a surface is removed, and a convex lens array (320-1, 320-2,...
20-n), a special color liquid crystal panel 370 (liquid crystal / electrode layer 340, and a filter 360a sandwiching this layer 340) for displaying a parallax image for observation.
360b), a camera 202 for photographing the observer's face, an image processing device 400 for generating n sets of backlight control images, and one set of observation parallax images for the left and right eyes. A color image output device 550 and a control device 506 for dividing and displaying one set of parallax images for observation from the image output device 550 on each display area of the color liquid crystal panel 370 are provided. Here, the color liquid crystal panel 370
Represents a plurality of strip-shaped display areas (340R-1, 340L-1, 340R) in which the display screen is divided into 2 m pieces for each display line.
., 340R-m, 340L-m) (see FIG. 22 for the configuration of this layer 340) and the liquid crystal / electrode layer 340 in accordance with each pixel. 2m band-shaped areas (360
R-1, 360L-1, 360R-2, 360L-2,... 360
R-m, 360L-m)
60b. The liquid crystal / electrode layer 340 is obtained by removing in advance two polarizing plates attached to both front and back surfaces of a general color liquid crystal panel.

FIG. 20 shows the configuration of a monochrome liquid crystal display device 300 for displaying a backlight control image. This monochrome liquid crystal display device 300 has n cell image areas (300-1, 300) equal in number to the lens array 320.
-2,... 300-n). Image processing device 4
00, in each cell image area, as shown in FIG.
A backlight control image composed of two partial images is displayed. In FIG. 20, one partial image is an area 301R corresponding to the right half of the face, and the other partial image is an area 301L corresponding to a part other than the right half of the face. As described above, since the polarizing filter is removed from the surface of the liquid crystal display device 300, the light from the region 301R and the region 30R are not reflected.
It will have a different polarization than the light from 1L. That is, when the image processing device 400 outputs the control image divided by the number of cells to the liquid crystal display device 300, the right-eye backlight control image 301R is displayed in each cell image region.
And a left-eye backlight control image 301L are displayed,
Different polarizations are emitted from the respective control images.

FIG. 21 shows the structure of a lens system 320 for giving directivity to the light of the backlight control image. One lens covers one cell display area of the monochrome liquid crystal display device 300. FIG. 21 schematically shows a lens as a circle, but it is desirable that the four corners of the lens should not be opened as shown in FIGS. FIG. 24 shows a part of a general color liquid crystal panel 370 ', which is presented for comparison with the color liquid crystal panel 370 of the second embodiment. In FIG. 24, an arbitrary two-pixel area is shown as a representative. That is, the general liquid crystal panel 37
0 'is sandwiched between two polarizing plates on both sides as shown in FIG. Here, X on the backlight light incident side
The polarizing plate transmits X-polarized light, but substantially blocks Y-polarized light whose polarization axis is orthogonal to the X-polarized light. The Y-polarizing plate on the backlight emission side transmits Y-polarized light and blocks X-polarized light. In FIG. 24, color filters and the like are omitted for convenience of explanation.

A part of the liquid crystal / electrode layer 340 'shown in FIG.
As shown in FIG. 4, it is assumed that the area is divided into two areas by chance. As is well known, the upper region is a region that transmits polarized light as it is, and is referred to as a black region for convenience,
The lower region is a region where the polarized light is rotated by 90 degrees, and is called a white region for convenience. It is well known that the operation of these regions can be reversed depending on the definition of the applied voltage.

Accordingly, when ordinary unpolarized light enters the X-polarizing plate as backlight, only X-polarized light enters the liquid crystal / electrode layer 340 '. The X-polarized light is emitted as X-polarized light without changing the polarization axis even when passing through the black region.
Emitted as polarized light. Therefore, when the X-polarized light and the Y-polarized light pass through the Y-polarizing plate, only the Y-polarized light passes, so that only the white region (the lower region in FIG. 24) appears in the eyes of the observer. Actually, this effect is exerted in accordance with the applied voltage for each pixel, thereby expressing the shading of the image.

When the liquid crystal panel shown in FIG. 24 is a color liquid crystal panel, only a color filter is added to add color to transmitted light, and the principle of transmitted light control of the color liquid crystal panel is also illustrated. 24. On the other hand, the operation principle of the color liquid crystal panel 370 of the second embodiment will be described with reference to FIG. 22, FIG. 23, and FIG.

As shown in FIG. 22, 2 m display lines are set on the color liquid crystal panel 370 for displaying the parallax image for observation. Further, as described above, the liquid crystal / electrode layer 340 has a 2m band-like display area (340R-1, 340L-1, 340R-2, 3R) as shown in FIG.
. 340R-m, 340L-m) and the display areas (340R-1, 340R-2,.
m) displays a parallax image for right eye observation in the display area (340L-
, 340L-m), the parallax images for left eye observation are displayed separately from each other.

On both surfaces of the liquid crystal / electrode layer 340 of the second embodiment, polarizing filters 360a and 360b are provided instead of the polarizing plates provided in a normal liquid crystal panel. FIG. 23 shows the configuration of each of the polarizing filters 360a and 360b. As shown in FIG. 23, the filters 360a,
360b has the same size as the display surface of ', and has a plurality of strip-shaped polarizing filter pieces 360R and 360L arranged alternately. The polarization filter pieces 360R and 360L have polarization axes different from each other. Then, every other one of the plurality of filter pieces (360R-1, 360R-2,... 360R-m) has a polarization axis in one direction (for convenience, the X direction).
The other plurality of filter pieces (360L-1, 36
0L-2,... 360L-m) all have a polarization axis in a direction orthogonal to the X direction (Y direction for convenience). The length of one filter piece in the vertical direction is equal to the width of space division of the display area on the display surface of the liquid crystal / electrode layer 340. That is, the width of one display area of the liquid crystal panel 370 is equal to the width of one filter piece of the polarizing filter. Filters 360a and 3
Numeral 60b is set so that the polarization axes of the same pixels are orthogonal to each other.

The image processing device 400 generates a right-eye backlight control image according to the same principle as the image processing device 211 of the first embodiment. Image processing device 40 of second embodiment
0 is different from the image processing apparatus 211 of the first embodiment.
The point is that only the right-eye backlight control image is generated.
FIG. 25 shows an example in which an arbitrary right-eye pixel is connected to panel pieces 340RB and 340 in order to explain the operation of the color liquid crystal panel 370.
RW, and any left-eye pixel is a panel piece 340LB, 3
This is schematically shown as 40 LW.

The region 360 _{bR in} FIG. 25 (or the region 360R-k in FIG. 23) allows only the X-polarized light to pass through the backlight incident surface, and the region 360 _bL (or the region 360L-k in FIG. 23) in FIG. Pass only polarized light. In FIG.
It is assumed that a parallax image in which black and white are displayed vertically is displayed on each of panel pieces 340R and 340L. Then, the area 340R for displaying the parallax image for the right eye
B is a black area where the polarization axis does not rotate, and the area 340RW is a white area where the polarization axis is rotated. On the other hand, an area 340L where a parallax image for the left eye is displayed.
B is a black area, and the area 340LW is a white area. Therefore, the parallax image area 340 for the right eye
X-polarized light from RB, Y-polarized light from region 340RW,
On the other hand, the area 340LB for the left eye is Y from the black area.
Polarized light is also emitted from the region 340LW, and X-polarized light is incident on the filter 360a. Therefore, the light emitted from the filter 360a is Y from the region _360aR.
As for the polarized light, the X-polarized light is emitted only from the white region from the region 360 _aL . That is, for the observer, X
A right-eye parallax image illuminated only by polarized backlight light and a left-eye parallax image illuminated only by Y-polarized backlight light arrive. At this time, the lens system 320
By providing the X-polarized light with directivity toward only the right eye and the Y-polarized light with directivity toward only the left eye, the left and right eyes of the observer can separate the left and right parallax images. It will be reflected as a so-called stereoscopic image. In order to provide directivity to the penalty light for changing the amount, the size and display position of the backlight control image displayed on the monochrome liquid crystal display device 300 are adjusted in advance as described in the section of the related art. It is necessary to keep.

The control device 506 controls the display of a set of parallax images for observation on the color liquid crystal panel 370 alternately for each pixel line. <Modification of Second Embodiment> The image display device of the present invention is not limited to the above-described embodiment, and various other aspects can be changed.

For example, the filters 360a and 360b attached to the front and back of the liquid crystal / electrode layer 340 are set to have orthogonal polarization axes in the same pixel.
This is because the driving mode of the liquid crystal is considered as a normally white mode in which the attenuation of transmitted light is small in the absence of an electric field. Must have the same polarization axis.

Further, for example, if a configuration in which the display area of the parallax image for the right eye is driven in the normally white mode and the display area of the parallax image for the left eye is driven in the normally black mode is employed, the polarization on the output side can be improved. The plate can be a polarizing plate having a polarization axis in one direction. still,
The liquid crystal panel 370 is configured such that the portions driven in the normally white mode have the polarization axes of the front and back polarizing plates orthogonal to each other, and the portions driven in the normally black mode have the same polarization axis.

Further, in the above embodiment, the liquid crystal panel from which the exit-side polarizing plate is removed is used as the backlight light source capable of outputting two polarized lights orthogonal to each other. It is also possible to adopt a configuration in which the above polarizing plates are alternately attached to each line. In this case, the driving mode of the liquid crystal panel must be a normally white mode when the polarization axes of the front and back polarizing plates are orthogonal, and a normally black mode when the polarizer and the analyzer have the same polarization axis. Further, when a polarizing plate is attached such that two types of polarizing plates orthogonal to the emission surface are attached for each line, a self-luminous device such as a plasma display, a CRT, or a solid-state imaging device array can be used. is there. When such a configuration is adopted, a backlight control image for the right eye and a backlight control image for the left eye must be displayed in accordance with two types of polarizing plates orthogonal to the emission side.

In the space division method of the second embodiment, instead of the above-described color liquid crystal panel 370, a polarizing filter in which a pair of strip-shaped polarizing filter pieces whose polarization axes are orthogonal to each other are alternately arranged, A polarizing film may be used in which a right-eye image is recorded at a position corresponding to the first polarizing filter piece, and a photographic film on which a left-eye image is recorded at a position corresponding to the second polarizing filter piece. It is possible.

The two types of polarizing filters having orthogonal polarization axes to be attached to the color liquid crystal panel do not always need to be attached to each horizontal line. It is possible to take various forms such as a checkered pattern. The space division method has been described above. Alternatively, the right-eye observation parallax image signal and the left-eye observation parallax image signal may be performed in a time-division manner, for example, alternately for each frame. A color liquid crystal panel 370 that displays a parallax image for right eye observation and a parallax image for left eye observation
When the output to the LCD is performed in a time-division manner, the backlight from the monochrome liquid crystal display device 300 does not need to use two polarized lights, and a non-polarized matrix light source other than the liquid crystal can be used. is there. Therefore, in this case, a general color liquid crystal panel may be used.
The light image of the right half face is displayed on the monochrome liquid crystal display device 300 in synchronization with the output of the parallax image for the right eye observation on the color liquid crystal panel, and the output of the suggestion image for the left eye observation on the color liquid crystal panel 370. Thus, a light image of the left half face is projected on the monochrome liquid crystal display device 300.

In this case, the monochrome liquid crystal display 3
The outgoing side polarizing plate of 00 and the incoming side polarizing plate of the color liquid crystal panel 370 must have the same polarization axis. <Stereoscopic Image Display System> Third Embodiment A system according to a third embodiment described below performs left and right separation by an optical filter that switches the phase of incident light.

FIGS. 26 and 27 schematically show the configuration of the display system of the third embodiment. In particular, FIG. 26 shows a case where the system is viewed from above, and FIG. 27 shows a case where the system is viewed from the side. In these figures, reference numeral 500 denotes a flat light source using a cathode tube, and a monochrome liquid crystal display device 501 is provided in front of the flat light source.
Is placed. In the liquid crystal display device 501, a polarizing plate (not shown) is provided on the incident side surface, that is, the surface on the cathode tube 500 side, of the two surfaces.
That is, no polarizing plate is provided on the surface on the side opposite to the cathode tube 500. Therefore, light transmitted through the liquid crystal display device 501 has two polarization states whose polarization directions differ by 90 degrees depending on the voltage application state. It becomes light. On the display surface of the liquid crystal display device 501, a half-side image obtained from the face image of the observer captured by the monochrome camera 505, that is, a backlight control image is displayed. The backlight control image is generated by the control image generation circuit 530, and the generation principle is exactly the same as in the first and second embodiments.

In front of the liquid crystal display device 501, Fresnellen
Is placed. This Fresnel lens 502
It may be the same as the Fresnel lens of the first embodiment. Fresnel
In front of the lens 502, a 90 degree phase difference is generated in the transmitted light.
The retardation film 503 to be formed is further
Color liquid crystal panel 504 is placed. Retardation film
Reference numeral 503 has a function of switching the phase of transmitted light by 90 degrees.
You. The color liquid crystal panel 504 includes an image signal synthesizing circuit 5.
11 and the parallax image for right eye observation multiplexed by area division
The parallax image for eye observation is displayed. That is, after FIG.
As described above, each scanning line of the liquid crystal / electrode layer 504a is
And the left-eye scanning line 504a _LNow, the parallax image for left eye observation
Displayed, right eye scanning line 504a_RThen parallax for right eye observation
The image is displayed.

FIG. 29 shows a detailed structure of the color liquid crystal panel 504 and the retardation film 503. As shown in FIG. 29, the retardation film 503 is a color liquid crystal panel 5
Over 04 on the backlight side flat polarizing plate affixed to the face of 504d, strip 90 degree phase difference plate having substantially the same width W to the width of one display line (503 _1, 503 _2, ... 5
03 _n ) are attached at equal intervals parallel to the display lines and at an interval D substantially equal to the width of the display lines.

FIGS. 30 to 32 show a 90 ° phase difference plate 503.
The principle of will be described. The retardation plate 503 used in the present embodiment is a λ / 2 wavelength plate, which is different from the wavelength plate in that the difference in speed due to the polarization state of light traveling in the anisotropic crystal, that is, the difference in refractive index is utilized. Element. The optical axis of the λ / 2 wavelength plate is set in the Z direction, and linearly polarized light R _I oscillating in the XZ plane at 45 degrees from the X axis from the Y axis direction (the direction perpendicular to the paper surface in FIGS. 30 to 32). When 30) enter vertically, the linearly polarized light R _I proceeds divided into component vibrating component vibrating in the Z direction in the crystal (the extraordinary light) in the X-axis direction (ordinary ray), their amplitudes become equal. However, since the refractive index of the crystals differs between extraordinary light and ordinary light, the refractive index of the former n _e, the refractive index When n _O against the latter, if n _e> n _O, the extraordinary light in comparison with ordinary light In this case, the speed in the crystal becomes slower, and a phase delay (phase difference) occurs at the emission end from the wave plate. Both optical phase difference [delta] of after the crystal transmittance is expressed by δ = (2πd / λ) ( n e -n o). Here, d represents the thickness of the wave plate, and λ represents the wavelength of the transmitted light.

Then, if the thickness d of the wave plate is adjusted according to the wavelength λ of the transmitted light in the crystal so that the phase difference δ becomes λ / 2 (= π), the extraordinary light at the exit end is reduced. Λ from ordinary light
/ 2 will be delayed. Therefore, the polarization planes of the ordinary light and the extraordinary light of the outgoing light are λ / 4 (= π / π) as compared with those of the incident light.
2) Since the phase is delayed, if a λ / 2 wavelength plate is used, it is possible to provide a 90 ° phase difference between the polarization planes of the incident light and the output light.

Unlike the second embodiment, the color liquid crystal panel 504 of the third embodiment is a normal color liquid crystal display. As is well known, the electrode / liquid crystal layer 504a has a liquid crystal material sandwiched between a pixel electrode layer and a common electrode layer with an alignment film interposed therebetween, and a protective glass plate is provided outside each of the two electrode layers. Is provided. The interval between the pixel electrodes is equal to the width D of one scanning line.

The retardation film 503 and the color liquid crystal panel 504 are connected to the retardation film 50 as shown in FIG.
3 and the pixel arrangement of the electrode / liquid crystal layer 504a are overlapped. FIG. 33 shows that the left-eye polarized light and the right-eye polarized light emitted from the liquid crystal display device 501 in the third embodiment are:
The process of entering light into the right-eye scanning line and the left-eye scanning line of the color liquid crystal panel 504, respectively, will be described.

Since the liquid crystal display device 501 is provided with a polarizing plate only on the side of the flat light source 500 using a cathode ray tube, FIG.
As shown in (1), in a pixel electrode (not shown) of the liquid crystal display device 501, light passing through a region of liquid crystal molecules to which a voltage is applied and light passing through a region of liquid crystal molecules to which a voltage is not applied are: Have different polarization states (states in which the polarization azimuths are orthogonal to each other).
When the backlight control image processed by the control image generation circuit 530 is displayed at 1, the region 501L (FIG. 26) corresponding to the left eye position of the observer is polarized light for the left eye backlight,
The region 501R other than the region 501L emits polarized light for the right-eye backlight.

This state is shown in FIG. 33 as a case where “left-polarized light” and “right-eye polarized light” are emitted from the liquid crystal display device 501 in different phase states but in a superimposed state. . In particular, in FIG.
"Backlight emitted light" is indicated by the arrow
Horizontal hatching is used for the left eye and vertical hatching for the right eye.

Hereinafter, the left-eye polarization at the time of emission from the liquid crystal display device 501 will be referred to as “X” polarization for convenience of description, and the polarization direction of the right-eye polarization at the time of emission from the liquid crystal display device 501 will be referred to as “X” polarization. Y "polarized light. Liquid crystal display device 501
Of the superimposed light of X-polarized light and Y-polarized light emitted from
As shown in FIG. 33, the light passes through each band element (503 ₁ ,..., 503 _n ) composed of the 90-degree phase difference plate 503 and is incident on the polarizing plate 504d (shown in FIG. 33). The light enters the polarizing plate 504d without passing through the retardation plate (shown in FIG. 33). Here, of the superimposed polarized light that has passed through the elements (503 ₁ ,..., 503 _n ) of the 90-degree phase difference plate, the X-polarized light, which is the left-eye polarized light, is rotated by 90 degrees in phase and becomes Y-polarized light, The Y-polarized light, which is the polarized light, becomes the X-polarized light.

That is, in the polarizing plate 504d, the region 504d _{R of the} polarizing plate 504d corresponding to the display line for the right eye of the color liquid crystal panel 504 transmits only the polarized light in the X-polarized state. And only the right-eye polarized light of the X-polarized right-eye polarized light is transmitted. On the other hand, the region 504 d _{L of the} polarizing plate 504 d corresponding to the left-eye display line of the color liquid crystal panel 504 is only the left-eye polarized light in the X-polarized state among the X-polarized left-eye polarized light and the Y-polarized right-eye polarized light. Through.

Thus, from the region 504d _{R of} the polarizing plate 504d corresponding to the display line for the right eye, only the polarization for the right eye is reached, and the polarization for the right eye reaches the liquid crystal molecules of the color liquid crystal panel corresponding to the display line for the right eye. Further, a region 503b of the polarizing plate 503b corresponding to the display line for the left eye.
_{From L,} only the left-eye polarized light reaches the liquid crystal molecules of the color liquid crystal panel corresponding to the left-eye display line.

FIG. 26, FIG. 29, FIG. 28, FIG.
Referring to FIG. 3, the right-eye polarized light (X-polarized light) given directivity so as to reach only the right eye of the observer is input only to the display line region 504a _R for the right-eye stereoscopic image.
As a result, it enters the observer's right eye. The left-eye polarized light (X-polarized light) provided with directivity so as to reach only the left eye of the observer is a display line area 504a for a left-eye stereoscopic image.
Input only to _L , resulting in the left eye of the observer.

Thus, good stereoscopic vision can be realized also in the third embodiment. In particular, if the positions of the band regions of the 90-degree retardation plate 503 and the positions of the display lines of the color liquid crystal panel 504a are accurately matched, a three-dimensional object with less crosstalk can be realized. <Stereoscopic Image Display System> Fourth Embodiment The systems of the first to third embodiments use a backlight, but the transmitted light control image of the present invention is a so-called “parallax barrier method”. Can be applied to the display of stereoscopic images.

FIG. 34 shows the configuration of the stereoscopic image display system according to the fourth embodiment. In the figure, 600R is a color CRT for displaying a parallax image for right eye observation, 600L is a color CRT for displaying a parallax image for left eye observation, 601R is a light transmissive monochrome liquid crystal panel for displaying a transmitted light control image for right eye, 601L. Is a light transmission type monochrome liquid crystal panel for displaying a transmission light control image for the left eye. When the transmitted light control image is displayed on the monochrome liquid crystal panels 601R and 601L,
The pixel portion of the liquid crystal panel 601 corresponding to “1” of the transmitted light control image has a property of transmitting light.

As in the first embodiment, the lens 204
Since the monochrome liquid crystal panel 601 gives directivity to the observation parallax image, the right-eye observation parallax image from the CRT 600R transmits through the right-eye transmission light control image 610R and enters only the right eye of the observer. On the other hand, the parallax image for left eye observation from the CRT 600L is the transmitted light control image for left eye 610.
L, and enters only the left eye of the observer.

Thus, the fourth embodiment can also realize good stereoscopic vision. Note that a time division method or a division method for each pixel using polarized light as in the third embodiment is also possible.

[0090]

As described above, according to the image display device of the present invention, the face position of the observer,
In particular, the position of the eyes can be accurately detected. Especially,
It is not affected by changes in the shape of the face of the observer, hairstyle, and the like.

[Brief description of the drawings]

FIG. 1 is a diagram showing a configuration of a conventional stereoscopic image display system.

FIG. 2 is a diagram showing a configuration of the stereoscopic image display system shown in FIG.

FIG. 3 is a view for explaining a method of generating a backlight control image according to a conventional example.

FIG. 4 is a view for explaining a method of generating a backlight control image according to a conventional example.

FIG. 5 is a view for explaining the principle of generating a control image used in each embodiment of the present invention.

FIG. 6 is a view for explaining a generation principle of a control image used in each embodiment of the present invention.

FIG. 7 is a view for explaining the principle of generation of a control image used in each embodiment of the present invention.

FIG. 8 is a view for explaining the principle of generation of a control image used in each embodiment of the present invention.

FIG. 9 is a view for explaining the principle of generation of a control image used in each embodiment of the present invention.

FIG. 10 is a timing chart illustrating the principle of detecting edges of a face image.

FIG. 11 is a diagram showing a configuration of a stereoscopic image display system according to a first embodiment in which the control image generation principle of the present invention is applied to a backlight system.

FIG. 12 is a diagram illustrating a configuration of the image processing apparatus according to the first embodiment.

FIG. 13 is a diagram illustrating a configuration of an edge detection circuit according to the first embodiment.

FIG. 14 is a diagram showing an optical path in the first embodiment.

FIG. 15 is a diagram showing an optical path in the first embodiment.

FIG. 16 is a diagram showing an optical path in the first embodiment.

FIG. 17 is a diagram showing a configuration of a modification of the convex lens.

FIG. 18 is a diagram showing a configuration of a modified example of the convex lens.

FIG. 19 is a diagram showing a configuration of a display device according to a second embodiment of the present invention.

FIG. 20 is a diagram illustrating a configuration of a display device 300 for displaying a backlight according to the second embodiment.

FIG. 21 is a diagram illustrating a configuration of a lens system 320 for imparting directivity according to a second embodiment.

FIG. 22 is a diagram illustrating a configuration of a liquid crystal / electrode layer 340 that displays a parallax image for observation according to the second embodiment.

FIG. 23 is a liquid crystal shutter (filter) according to the second embodiment.
FIG. 3 illustrates a configuration of a 360.

FIG. 24 is a diagram showing a configuration of a conventional liquid crystal panel 370 ′ for comparison with the configuration of the liquid crystal panel 3700 of the second embodiment.

FIG. 25 is a view for explaining the operation of the liquid crystal panel 370 of the second embodiment.

FIG. 26 is a diagram illustrating the configuration of the observation parallax image display device according to the third embodiment, which is described from above.

FIG. 27 is a view for explaining the configuration of the observation parallax image display device of the third embodiment from the side.

FIG. 28 is a diagram illustrating a positional relationship between each element position of a 90-degree phase difference plate and a scanning line of a color liquid crystal panel 504 in the third embodiment.

FIG. 29 is a diagram illustrating a positional relationship between a retardation film 503 and a color liquid crystal panel 504 according to the third embodiment.

FIG. 30 is a view for explaining the polarization state of incident light for explaining the operation principle of the λ / 2 wavelength plate used in the third embodiment.

FIG. 31 is a view for explaining the polarization state of emitted light for explaining the operation principle of the λ / 2 wavelength plate used in the third embodiment.

FIG. 32 is a view for explaining the operation principle of the λ / 2 wavelength plate used in the third embodiment and explaining the phase difference between the polarization planes of incident light and output light.

FIG. 33 is a diagram illustrating a process in which left-eye polarized light (or right-eye polarized light) from a backlight is incident on a left-eye scanning line (or right-eye scanning line) of the color liquid crystal panel 504 in the third embodiment.

FIG. 34 is a view for explaining the configuration of the fourth embodiment.

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Eiji Arita 1500 Inoguchi, Nakai-machi, Ashigarakami-gun, Kanagawa Prefecture Inside Terumo Corporation (72) Inventor Tomohiko Hattori 3-1-28 Daiko, Higashi-ku, Nagoya-shi, Aichi 10C U-House Taiko 10C

Claims (17)

[Claims] 1. An image display device for detecting an area on the face of an observer as a position near both eyes in a pseudo manner, and observing a first image and a second image different from both eyes of the observer. A means for imaging the face of the observer; a detecting means for detecting a substantially central position of the face image in a horizontal direction based on image data of the face of the observer obtained by the imaging means; Generating means for generating a right-eye control image and a left-eye control image based on the approximate center position of the face image; display means for displaying the right-eye control image and the left-eye control image; and Using the right-eye control image and the left-eye control image, provide directivity to the light representing the first image and the light representing the second image to provide directivity toward the right and left eyes of the observer, respectively. Means. That the image display device. 2. The image display device according to claim 1, wherein the first image and the second image are stereoscopic images captured with a predetermined parallax. 3. The image display device according to claim 1, wherein said detecting means includes means for binarizing image data of said face image. 4. The image display device according to claim 1, wherein said detecting means includes means for scanning image data of said face image in a horizontal direction. 5. The detecting means detects a position at which a value of image data of the face image greatly changes,
5. The image display device according to claim 1, wherein a position of a contour of the face in the image data is identified. 6. The image display apparatus according to claim 5, wherein said detecting means identifies a center position between two points in the horizontal direction on the detected contour of the face as a substantially center position of the face. . 7. The apparatus according to claim 1, wherein said detecting means includes means for scanning said face image in a vertical direction, and detects a plurality of points in a vertical direction at a central position in a horizontal direction. 7. The image display device according to any one of claims 6 and 7. 8. The image display device according to claim 1, wherein said directivity providing means has a convex lens or a Fresnel lens. 9. The image display device according to claim 8, wherein the convex lens or the Fresnel lens is configured in an array. 10. The display device according to claim 1, wherein the display unit emits light at a position where a dot of the control image is output, so that the light of the control image functions as a backlight. The image display device as described in the above. 11. A display device for displaying the first image and the second image, wherein the display means is arranged in front of the display device,
The control image displayed on the display means functions as a parallax barrier by being a light transmissive monochrome liquid crystal display device.
0. The image display device according to any one of 0. 12. The display means has a set of liquid crystal display devices arranged at right angles to each other, and the directivity providing means includes a half mirror arranged in front of the set of liquid crystal display devices. The image display device according to any one of claims 1 to 11, comprising: 13. A display device capable of displaying the first image and the second image in a time-division manner, wherein the display unit is configured to display the first image and the second image on the display device. In synchronization with the switching timing with
12. The image display device according to claim 1, wherein the right-eye control image and the left-eye control image can be displayed in a time-division manner. 14. A display device further comprising a display device in which a first area for displaying the first image and a second area for displaying the second image are substantially uniformly arranged on one display surface, The display means displays the right-eye control image and the left-eye control image with different first polarized light and second polarized light, and in the display device, the first region has the first polarized light. The second region substantially transmits as the backlight light and substantially blocks the second polarized light, and the second region substantially transmits the second polarized light as the backlight light and substantially transmits the first polarized light. The image display device according to any one of claims 1 to 10, wherein the image display device is configured to block the image. 15. The image display device according to claim 1, wherein said imaging means has only one camera. 16. The image display device according to claim 1, wherein said imaging means has one or a plurality of illumination devices. 17. The image display device according to claim 1, wherein said imaging means is arranged substantially at the center in front of an observer.