JPH0772445A - 3D display device - Google Patents

Abstract

(57) [Abstract] [Purpose] To provide a three-dimensional display device that remarkably expands a stereoscopic observation region and reproduces a high-quality stereoscopic image with high resolution. [Configuration] A liquid crystal panel (1) that simultaneously displays a plurality of different parallax images, and an optical characteristic variable lens that is mounted on the liquid crystal panel (1) and is composed of an array of cylindrical lenses and that can change the optical characteristics of the cylindrical lenses. (2), a head detection unit (3) for detecting the spatial position of the observer's head, and a head connected to the head detection unit (3) and detected by the head detection unit (3) An optical characteristic variable lens control section (4) for controlling the optical characteristic variable lens (2) so that a stereoscopic image is reproduced at the optimum position of the head based on the position information of the section.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a three-dimensional display device capable of reproducing a stereoscopic image without requiring special glasses.

[0002]

2. Description of the Related Art Conventionally, there is a three-dimensional display device using a lenticular lens as a three-dimensional display device in which a stereoscopic image can be viewed without special glasses. A three-dimensional display device using this lenticular lens is a liquid crystal display device because it is easy to align the lenticular lens corresponding to each pixel of the display screen and the distance between the display screen and the lenticular lens can be narrowed. Adapted to flat panel displays such as.

FIG. 12 shows a conventional three-dimensional display device using a lenticular lens. This three-dimensional display device is a type in which a lenticular lens is directly attached to the display surface of a liquid crystal panel. It is a twin-lens system in which two different parallax images are simultaneously displayed on the liquid crystal panel. A part of the parallax image corresponding to the left eye (hereinafter, the image for the left eye) is displayed on the display pixel Di1 of the liquid crystal panel 1, and a part of the parallax image corresponding to the right eye (hereinafter, the image for the right eye) is displayed on the display pixel Di2. There is.
A cylindrical lens Li is placed corresponding to the pair of display pixels Di1 and Di2. Display pixels Di1, D
The light transmitted through i2 is displayed in the display space P and the display space Q in the observation area by the action of the cylindrical lens Li.
Is separated into The same thing happens with i from 1 to n, the left-eye images are collected in the display space P, and the right-eye images are collected in the display space Q.
A stereoscopic image can be observed by bringing the left eye and the right eye into the display space P and the display space Q, respectively.

As described above, in the lenticular-type three-dimensional display device, the space in which the stereoscopic image can be observed is limited, and exists in everywhere.

On the other hand, a multi-lens system for reproducing a large number of different parallax images may be adopted for the purpose of expanding a space in which a stereoscopic image can be observed. However, in that case, a large number (three or more) of different parallax images must be simultaneously displayed on the liquid crystal panel 1, and the number of display pixels of the liquid crystal panel 1 is limited.
The resolution of one parallax image is greatly reduced.

Therefore, in order to observe a high-resolution stereoscopic image in a wider space, the position of the observer's head is detected while reproducing the stereoscopic image of the twin-lens type, and the stereoscopically reproduced image is located at that position. There is a conventional head-tracking three-dimensional display that matches.

The position of the observer is, for example, constantly photographed by a video camera, and the contour of the face or the position of the eyes is detected from the image signal. So that the stereoscopic reproduction image is displayed at that position,
Control.

FIG. 13 shows a diagram for explaining the basic principle of a head tracking three-dimensional display. The principle of placing a lenticular lens 100 on the front surface of the liquid crystal panel 1 and reproducing a stereoscopic image is the same as the principle described in FIG.

The difference from FIG. 12 is the lenticular lens 1.
00 is connected to the lens moving device 101, and the relative position of the lenticular lens 100 with respect to the liquid crystal panel 1 can be changed. When the relative position of the lenticular lens 100 with respect to the liquid crystal panel 1 changes, the direction of emission from the cylindrical lens changes due to the action of each cylindrical lens forming the lenticular lens.
The positions P ', Q'in the display space can be controlled.

The lens moving device 101 is a device for accurately controlling the position of the lenticular lens 100. Therefore,
It consists of a precise mechanical system.

By moving the lenticular lens, the position where the stereoscopic image is reproduced is controlled so as to match the detected position of the head.

[0012]

As described above, in the conventional twin-lens type three-dimensional display device, the space where the stereoscopic image can be observed is extremely limited based on the principle of the lenticular system.

In the conventional multi-lens type three-dimensional display device, the viewing space for stereoscopic images is widened by the number of eyes, but the resolution of one parallax image deteriorates, and only low-quality stereoscopic images can be reproduced.

Further, in the conventional head-tracking type three-dimensional display device, the relative positions of the liquid crystal panel and the lenticular lens must be controlled very accurately. Therefore, since a precise mechanical system is used, the device becomes large, and a relatively large lenticular lens is moved, so that there is a problem that the position control of the display space is not responsive. Further, since the lenticular lens is moved only in the plane parallel to the display panel, the head-tracked range is limited to the plane parallel to the display panel.

Furthermore, the conventional head-tracking type three-dimensional display is of a twin-lens type, and the stereoscopic image observed does not change even if the head is moved, and a natural stereoscopic image is not reproduced.

In view of the above-mentioned problems in the conventional three-dimensional display device, an object of the present invention is to realize a head-tracking type three-dimensional display device which does not include a mechanical system, and to remarkably expand the stereoscopic observation area, An object of the present invention is to provide a three-dimensional display device that reproduces a high-quality stereoscopic image with resolution.

Another object of the present invention is to provide a three-dimensional display device capable of naturally observing a three-dimensional image by reproducing a three-dimensional image of the contents at the position of the head in addition to the above-mentioned characteristics. .

[0018]

SUMMARY OF THE INVENTION An object of the present invention is to display a plurality of different parallax images at the same time, and an array of cylindrical lenses mounted on the display means and to determine the optical characteristics of the cylindrical lenses. A variable optical means, a detecting means for detecting the spatial position of the observer's head, and a three-dimensional position at the optimum position of the head based on the position information of the head connected to the detecting means and detected by the detecting means. And a control means for controlling the optical means so that the image is reproduced.

Another object of the present invention is an optical means which is composed of an array of cylindrical lenses which is mounted on the display means and which displays a plurality of different parallax images at the same time and which can change the optical characteristics of the cylindrical lenses. When,
Detection means for detecting the spatial position of the observer's head, so that a stereoscopic image is reproduced at the optimum position of the head based on the position information of the head connected to the detection means and detected by the detection means Control means for controlling the optical means, a plurality of stereoscopic signal sources for performing multi-view display, based on positional information of the head detected by the detection means connected to the plurality of stereoscopic signal sources and the detection means It is also achieved by a three-dimensional display device including selection means for selecting a stereoscopic signal to be displayed on the display means.

The optical means of the three-dimensional display device of the present invention may be composed of liquid crystal.

Further, the three-dimensional display device of the present invention may include a projection lens and a diffusion layer between the display means and the optical means.

[0022]

In the three-dimensional display device according to the first aspect of the invention, a plurality of different parallax images are simultaneously displayed on the display means every other display pixel row, and the optical means is mounted on the upper surface thereof. The optical means is composed of an array of cylindrical lenses whose optical characteristics are electrically controlled. The plurality of parallax images displayed on the display means by the action of the optical means are separated and projected onto a certain observation area. The observer can observe stereoscopic vision by seeing different parallax images with different eyes at the same time. The detection means detects the spatial position of the observer's head. The control means receives the position information of the head from the detection means, and controls the optical characteristics of the optical means so that the stereoscopic image is reproduced at the optimum position based on the information.

In the three-dimensional display device of the second invention,
A plurality of different parallax images are simultaneously displayed on the display means every other display pixel column. A plurality of stereoscopic signal sources for multi-view display are prepared, and the stereoscopic signal to be displayed on the display means is selected by the selection means. Optical means is mounted on the upper surface of the display means. The optical means is composed of an array of cylindrical lenses whose optical characteristics are electrically controlled. The plurality of parallax images displayed on the display means are separated by the action of the optical means,
It is projected on a certain observation area. An observer can observe a stereoscopic image by viewing different parallax images with different eyes at the same time. The detection means detects the spatial position of the observer's head. The control means is
The positional information of the head is received from the detecting means, and the optical characteristic of the optical means is controlled so that the stereoscopic image is reproduced at the optimum position based on the information. Further, the selection means receives the position information of the head from the detection means, selects a stereoscopic signal matching the position and displays it on the display means.

In the third invention, since the optical means is composed of liquid crystal, there is a large change in the refractive index, and the optical characteristics of the lens can be changed at a low voltage.

In the fourth invention, the projection lens and the diffusion layer are provided between the display means and the optical means to realize a projection type three-dimensional display and enable a large screen display.

[0026]

Embodiments of the three-dimensional display device of the present invention will be described below with reference to the drawings.

FIG. 1 is a sectional view showing the structure of the first embodiment of the three-dimensional display device of the present invention.

The three-dimensional display device of this embodiment is of a twin-lens type and is of a type in which a variable optical characteristic lens is attached to a flat display panel, and is configured to electrically control the reproduction space of a stereoscopic image. Has been done.

The three-dimensional display device of FIG. 1 has a liquid crystal panel 1 as a display means, an optical characteristic variable lens 2 as an optical means arranged in close contact with the liquid crystal panel 1, a head detecting section 3 as a detecting means, It is configured by an optical characteristic variable lens control unit 4 which is a control unit connected to the optical characteristic variable lens 2 and the head detecting unit 3.

The liquid crystal panel 1 has two different parallax images.
It is displayed every other pixel. Display pixel D of liquid crystal panel 1
A part of the parallax image corresponding to the left eye of i1 (hereinafter, the image for the left eye) corresponds to the parallax image corresponding to the right eye of the display pixel Di2 (hereinafter,
A part of the image for the right eye is displayed (hereinafter i is i = 1)
~ N).

The same display is made on each scanning line, and a part of the same parallax image is connected in the vertical direction of the display panel. When a color liquid crystal panel is used as the liquid crystal panel 1, one unit of color (for example, red, green, blue) must be arranged in the vertical direction. Otherwise, the image forming positions of the pixels of each color are separated by the action of the lens, and the reproduced image causes color shift.

The liquid crystal panel 1 can be replaced with another flat panel display. For example, an electroluminescence (EL) panel or a plasma display can be used.

The variable optical characteristic lens 2 is a lens having the same function as a lenticular lens, and its lens characteristic can be electrically controlled. Here, the variable optical characteristic lens 2 is composed of an array of cylindrical lenses Li.

FIG. 1 shows a cross section of the cylindrical lens Li, and the longitudinal direction of the lens and the direction perpendicular to the paper surface coincide with each other. In addition, the longitudinal direction of the lens is aligned with the pixel row in which the same parallax image is displayed on the liquid crystal panel 1. Details of the variable optical characteristic lens 2 will be described later.

Display pixels Di1 and Di2 in the liquid crystal panel 1
The cylindrical lens Li in the variable optical characteristic lens 2 corresponds to the pair, and they are arranged in close contact with each other.
The light transmitted through the display pixels Di1 and Di2 is separated and projected into the display space P and the display space Q of the observation area by the action of the cylindrical lens Li. This is i
The same thing occurs in all the display pixels from to n, and the display space P in which the image for the left eye is projected and the display space Q in which the image for the right eye is projected are formed. An observer can observe a stereoscopic image by bringing the left eye and the right eye into the display space P and the display space Q, respectively. The positions of the display space P and the display space Q can be controlled by changing the relative positional relationship between the display images Di1 and Di2 and the cylindrical lens Li.

The head detecting section 3 is arranged around the liquid crystal panel 1 and detects the spatial position of the observer's head and outputs the positional information of the head. Here, the head detecting unit 3 is of the following type.

First, the first method is a method using an infrared light emitting / receiving element as the head detecting section 3. In the first method, the position of the observer's pupil is detected by receiving the infrared light emitted from the infrared light emitting element and reflected by the observer's pupil by the infrared light receiving element.

The second method is a method in which the face of an observer is always captured by a video camera and the image of the face is subjected to image processing to recognize the pupil and detect the spatial position of the observer's pupil. In the second method, the head detecting unit 3 is composed of a video camera, an image processing / recognizing device, and a position detecting device.

The third method is to attach a magnetic field generator to the observer's head and detect the magnetic field generated from the magnetic field generator around the head using a plurality of magnetic field detectors provided on the panel side. By doing so, there is a method of detecting the spatial position of the head. That is, in the third method, the head detecting unit 3 is configured by a magnetic field generator, a plurality of magnetic field detectors, a device that processes signals from the magnetic field detectors, and the like. A magnetic field detector may be attached to the observer's head and a magnetic field generator may be provided on the panel side.

The position information of the head detected by the head detector 3 is sent to the variable optical characteristic lens controller 4.

The variable optical characteristic lens control unit 4 controls the size and distribution of the refractive index of each cylindrical lens in the variable optical characteristic lens 2 based on the head position information obtained by the head detecting unit 3. . Thereby, the direction of the light emitted from each cylindrical lens is changed, and the position of the space in which stereoscopic vision is reproduced is controlled.

FIG. 2 shows an example of the structure of the variable optical characteristic lens, and particularly shows a partial cross section of the variable optical characteristic lens using liquid crystal.

In the variable optical characteristic lens of FIG. 2, an electrode array 11 in which strip electrodes 11a, 11b, 11c, ... Are arranged on a glass substrate 13 is formed. Electrode array 11
Is a transparent electrode such as an ITO (indium tin oxide) film. In FIG. 2, the strip electrodes 11a, 11b,
11c, ... Represents a cross section, and is elongated in a direction perpendicular to the paper surface. The electrode 12 is formed on the other glass substrate 14. The electrode 12 is a uniform electrode on the entire surface of the glass substrate 14. The electrode 12 is also a transparent electrode.

The strip electrodes 11a, 11b, 11c, ... And the electrode 12 are each connected to a liquid crystal drive circuit (not shown).

A sealed liquid crystal 10 is provided between the electrode array 11 and the electrode 12. The liquid crystal molecules 10 'are initially aligned in a uniform state parallel or perpendicular to the glass substrate.

The refractive index of the liquid crystal molecules 10 'differs between the direction of the molecular axis and the direction orthogonal to the molecular axis. for that reason,
The liquid crystal molecules 10 'exhibit optical anisotropy. Glass substrate 1
The tilt angle of the liquid crystal molecules 10 'with respect to 3 and 14 changes depending on the voltage applied between the electrode array 11 and the electrode 12, and the refractive index exhibited by the aggregate of the liquid crystal molecules 10' changes accordingly. That is, the refractive index distribution of the variable optical characteristic lens can be controlled by controlling the voltage applied to the liquid crystal.

An example of the pattern of the voltage applied to the liquid crystal molecules 10 'will be shown. Now, assuming that the initial state is a homogeneous orientation (parallel to the glass substrate), the electrodes 11d and 11f, the electrodes 11c and 11g, and the electrode 1 are centered around the electrode 11e.
When the voltage applied in the order of 1b and 11h is decreased, the distribution of the refractive index of the aggregate of liquid crystal molecules 10 'changes as shown in FIG.

The width of the change in the refractive index of the aggregate of the liquid crystal molecules 10 'is defined between the maximum refractive index and the minimum refractive index of the liquid crystal molecules 10'.

As described above, if the pattern of the voltage applied to the electrode array 11 is changed, the distribution shape of the refractive index of the aggregate of the liquid crystal molecules 10 ', the entire level of the refractive index, and the pitch of the refractive index distribution which is periodically repeated. Can be controlled.

The optical characteristics of one cylindrical lens are defined by three items: the curvature of the lens cylindrical surface, the thickness of the lens, and the pitch of the lens. In the variable optical characteristic lens shown in FIG. 2, the curvature of the lens spherical surface has a distribution shape of the refractive index,
The lens thickness corresponds to the overall level of the refractive index, and the lens pitch corresponds to the pitch of the refractive index distribution.

Next, the relationship between the optical characteristics of the cylindrical lens and the stereoscopic playback position will be described with reference to FIGS.

FIG. 4 shows variables that determine the optical characteristics of the cylindrical lens. Central pixel Di1, D of the liquid crystal panel
There is a cylindrical lens Li corresponding to i2.
Shows the cross section. Cylindrical lens L
i has a cylindrical surface, its center of curvature is the origin, the longitudinal direction of the cylindrical surface is the y-axis, orthogonal to the y-axis, the direction in which the cylindrical lenses are arranged is the x-axis, and the x-axis is orthogonal to the y-axis. , And the axis extending in the observation direction is the z axis.

The curvature of the cylindrical surface of the cylindrical lens is R, the thickness is t, the pitch is Pl, and the refractive index of the lens medium is n.
And Further, the width (x-axis direction) of the display pixels Di1 and Di2 is Pd, and the shift (x-axis direction) PH between the midpoint of the display pixels Di1 and Di2 and the central axis (z-axis) of the cylindrical lens Li is set. The display pixel in the x-axis direction of the liquid crystal panel is D
And

A plane in the observation area which is parallel to the xy plane and is separated by a distance z _{0 is} defined as an aa 'plane, and the projected images P and Q projected on the aa' plane have a width in the x-axis direction. Is di and the distance between the midpoint A of the projected images P and Q and the z axis is x ₀ . The width di of the projected image is the average human eye (pupil) interval (about 65 m).
m) or more is preferable, but if the value is larger than necessary, the light is dispersed and the projected image becomes dark.

By controlling the point A so that the midpoints of the left and right eyes of the observer are aligned with each other, the observer can perform stereoscopic vision even if the head is moved within a certain range. The spatial position (x ₀ , z ₀ ) of the point A can be controlled by adjusting the variables t, R, P1, and PH that define the optical characteristics of the lens. Where P
d, D, n, and di have preset fixed values.

FIG. 5 shows the relationship between the images projected from one display pixel on the aa 'plane. It becomes a simple analogy,
Formula (1) is satisfied.

Pd / di = (t−R) / z ₀ (1) On the other hand, it is appropriate that the lenticular lens is focused on the liquid crystal display surface. The condition is satisfied by the equation (2).

1 / t = (n-1) /n.R ... (2) The thickness t of the lens and the radius of curvature R of the cylindrical surface can be obtained from the equations (1) and (2).

T = (n · z ₀ · Pd) / di (3) R = {(n−1) · z ₀ · Pd} / di (4) where t and R are head position detection Distance detected from the part z
It is calculated based on ₀ .

FIG. 6 shows two display pixels (because of the twin-lens type).
2 shows the relationship between the width 2Pd and the lens pitch P1. The setting of the lens pitch P1 is intended to concentrate the light transmitted through each display pixel in the reproduction space P or the reproduction space Q.

P1 / 2Pd = (z ₀ −R) / (z ₀ + t−R) (5) Here, P1 is obtained from the equations (1) and (3) to (5) as follows. To be

P1 = 2Pd · {di− (n−1) · Pd} / (di + Pd) (6) FIG. 7 shows the shift amount PH of the relative position between the display pixel and the lenticular lens and the position x _{0 of the} projected image. Shows the relationship. This is intended to control the spatial position of the center point A of the projected pattern.

PH / x ₀ = (t−R) / z ₀ (7) From equations (1) and (7), PH is represented by equation (8).

PH = (x ₀ · Pd) / di (8) Thus, the radius R of the cylindrical surface of the lens, the thickness t of the lens, the pitch P1 of the lens, and the display pixel at the center point of the liquid crystal panel. By controlling the relative displacement PH of the lens, the spatial position of the projection pattern (point A) can be controlled. Further, variables R, t, P1 and PH are set in advance and the width Pd of the display pixel of a known liquid crystal panel, the width di of the projected images P and Q projected on the aa ′ plane at a distance z ₀ , the lens It is calculated from the refractive index n of the medium and the head position (x ₀ , z ₀ ) obtained by the observer's head position detection unit.

In the variable optical characteristic lens shown in FIG. 2, the radius R of the cylindrical surface of the lens having the above variable corresponds to the shape of the refractive index distribution and is controlled by the shape of the voltage pattern applied to the electrode array 11. The lens thickness t corresponds to the overall level of the refractive index distribution and is controlled by the overall level of the voltage pattern applied to the electrode array 11. The lens pitch P1 corresponds to the pitch of the refractive index distribution that changes periodically, and is controlled by the pitch of the voltage pattern applied to the electrode array 11. Relative displacement P between the display pixel and the lens at the center point of the liquid crystal panel P
H corresponds to the phase of the refractive index distribution that changes periodically, and can be controlled by shifting the voltage pattern applied to the electrode array 11.

In this embodiment, all the optical characteristics of the lens can be electrically performed, and no mechanical portion is required.

FIG. 8 shows a structural cross section of another structural example of the variable optical characteristic lens.

In the variable optical characteristic lens of FIG. 8, the transparent whole surface electrode 23 is formed on the glass substrate 24. Full surface electrode 2
3 is composed of a transparent film such as ITO (indium tin oxide). The transparent object 20 having high flexibility is laminated on the entire surface electrode 23. When the transparent object 20 exhibits fluidity, the transparent film 21 is formed on the transparent object 20 so that the transparent object 20 does not flow out. The transparent film 21 is thin and flexible. For the transparent object 20, for example, silicone rubber or oil is used. A large number of strip-shaped electrodes 22 are formed side by side between the transparent object 20 and the transparent film 21. The strip electrode 22 has a cross section shown in FIG. 8, and extends in a direction perpendicular to the paper surface. It is composed of a strip electrode 22 and a transparent film such as ITO (indium tin oxide). A drive circuit (not shown) is connected to each of the strip electrodes 22. Further, the whole surface electrode 23 is also connected to the drive circuit.

The initial state of the surface of the transparent object 20 is a plane. A voltage is partially applied to the strip-shaped electrode 22 so that the entire surface electrode 2
The surface of the transparent object 20 or the transparent film 21 is made uneven by an electrostatic force acting between the transparent object 20 and the transparent object 21. A voltage having a polarity opposite to that of the voltage applied to the entire surface electrode 23 is applied to the strip electrodes 22b spaced at regular intervals. Then, a voltage having the same polarity as the voltage applied to the entire surface electrode 23 is applied to the strip-shaped electrode 22a at the intermediate position of the above-mentioned constant interval. An electrostatic attractive force acts between the strip electrode 22b and the entire surface electrode 23, and the distance between the strip electrode 22b and the entire surface electrode 23 is shortened. On the contrary, the strip electrode 22a
Electrostatic repulsion acts between the whole surface electrode 23 and the strip electrode 2
The distance between 2a and the entire surface electrode 23 is increased. The flexible transparent object 20 is deformed under the influence thereof. In this way, the cylindrical surface is periodically formed to form the cylindrical lens.

The unevenness of the cylindrical surface required as a lens is about 1 mm. In order to deform at a low voltage, it is effective to increase the electric field generated between the strip electrode 22 and the entire surface electrode 23. In the initial state (flat), the interval between the strip electrode 22 and the entire surface electrode 23 is 1.5 mm. It is preferable to adjust the degree.
There is a total lens thickness needed, which is adjusted by the thickness of the glass substrate 24.

The strip electrodes 22 to which a voltage is applied are not limited to 22a and 22b, and a series of strip electrodes 22 may be used.
The voltage may be applied according to the voltage pattern in.

The shape (curvature radius, thickness) of the cylindrical surface is controlled by the shape of the voltage pattern applied to the strip electrode 22. The cycle of the cylindrical surface is controlled by the cycle of the voltage pattern applied to the strip electrode 22. The position where the cylindrical surface is formed is controlled by shifting the voltage pattern applied to the strip electrode 22. In this way, the shape and position of the cylindrical surface formed on the surface of the transparent object 20 or the transparent film 21 can be controlled by the voltage pattern applied to the strip electrode 22.

As described above, the embodiment is configured to control the reproduction position of stereoscopic vision in accordance with the position of the observer so that stereoscopic vision can be observed in a wide range. However, since only two different parallax images are displayed on the liquid crystal panel, the stereoscopic image observed does not change even if the observer moves. That is, in this embodiment, the observation area of the twin-lens type three-dimensional display device is enlarged.

Normally, when the head of the observer moves, the observed stereoscopic image naturally changes. That is, a multi-view type having a plurality of stereoscopic images is desirable for a three-dimensional display. Next, an embodiment corresponding to the multiview system will be described.

FIG. 9 shows the configuration of another embodiment of the three-dimensional display device of the present invention.

The three-dimensional display device shown in FIG. 9 is a direct-view type three-dimensional display device in which a lenticular lens is placed on the front surface of a liquid crystal panel, and particularly shows a case of four-eye display.

The three-dimensional display device of FIG. 9 has a liquid crystal panel 1 which is a display means, an optical characteristic variable lens 2 which is an optical means arranged in close contact with the front surface of the liquid crystal panel 1, and a head detecting section which is a detecting means. 3, a head detecting unit 3, an optical characteristic variable lens control unit 4, which is a control unit connected to the variable optical characteristic lens 2, a stereoscopic signal synthesizing unit 42 connected to the liquid crystal panel 1, and a stereoscopic signal synthesizing unit 42. The stereoscopic signal selection unit 43, which is a selection unit, and the stereoscopic signal sources 33 to 36 connected to the stereoscopic signal selection unit 43.

In the three-dimensional display device of FIG. 9, the variable optical characteristic lens 2 is attached to the front surface of the liquid crystal panel 1. In an actual device, a display illumination light source is placed on the back surface of the liquid crystal panel 1, but it is omitted in FIG.

Although the liquid crystal panel is used as the image display panel in the embodiment shown in FIG. 9, a flat panel display such as an electroluminescence (EL) panel, a plasma display, and a light emitting diode (LED) array can be used. At that time, the display illumination light source is not required.

A color liquid crystal panel is usually used as the liquid crystal panel 1. At that time, the arrangement of the color filters of the liquid crystal panel is the same as the longitudinal direction (vertical direction) of the lenticular lens so that the color images are not separated by the action of the lens.

The variable optical characteristic lens 2 is an array of cylindrical lenses. The variable optical characteristic lens 2 of FIG.
2 shows a cross section of an array of cylindrical lenses elongated in the direction perpendicular to the plane of the drawing.

In the embodiment of FIG. 9, four different parallax images can be displayed, but two different parallax images can be displayed at the same time. Therefore, the variable optical-characteristic lens 2 used in this embodiment is the same as that used in a two-lens type three-dimensional display device. That is, the cylindrical lens Li in the variable optical characteristic lens 2 is placed corresponding to the pair of display pixels Di1 and Di2 (hereinafter, i = 1 to n is represented). The light transmitted through the pixels Di1 and Di2 is separated into the space P and the space Q of the observation region by the function of the cylindrical lens Li. Pixel D
When the left-eye parallax image is displayed in i1 and the right-eye parallax image is displayed in the pixel Di2, a stereoscopic image can be observed by bringing the left eye and the right eye into the space P and the space Q, respectively.

In FIG. 9, the shape of each cylindrical lens Li is the same, but the pitch of the pair of pixels Di1 and Di2 and the pitch of the cylindrical lens Li are different. The pitch of the cylindrical lens is set to be slightly smaller.
Therefore, in the periphery of the liquid crystal panel, the center of the pair of pixels and the center of the corresponding cylindrical lens deviate, and the amount of deviation increases toward the periphery. Due to this shift, the incident angle of the transmitted light from each pixel to the cylindrical lens is different between the center and the periphery of the liquid crystal panel 1, so that the transmitted light from the peripheral pixels of the liquid crystal panel 1 becomes the specific space P of the observation region. Can be collected in space Q.

As means for obtaining the parallax image displayed on the liquid crystal panel 1, four video cameras as shown in FIG.
There is an imaging system in which the central axis of the object is arranged at a constant interval toward the target object. As a result, four different images are obtained, but the image obtained by the camera 44 is referred to as image 1 and is used as the stereoscopic signal source 33 in FIG. Similarly, the image 2 obtained by the camera 45 corresponds to the stereoscopic signal source 34, the image 3 obtained by the camera 46 corresponds to the stereoscopic signal source 35, and the image 4 obtained by the camera 47 corresponds to the stereoscopic signal source 36. By observing the image of the left camera with the left eye and the image of the right camera with the right eye of two adjacent images, stereoscopic vision becomes possible. In the case of the four-lens type as in this embodiment, three-dimensional images in three different directions can be observed. Here, the three different stereoscopic images are (image 1 and image 2), (image 2 and image 3), and (image 3
And the image 4) is a stereoscopic image observed. In addition,
There is also a method of using computer graphics as a means for generating four different images. Further, the stereoscopic signal source may be one that moves in real time or one that is recorded in a storage system such as an optical disk.

The head detecting unit 3 is a device for detecting the spatial position of the observer's head, especially the midpoint of both eyes. There are several methods of head detection. As a first method, a method of detecting the head position of the observer by providing an infrared light emitting element in the head detecting unit, irradiating the near infrared ray to the head of the observer, and measuring the reflection intensity thereof. is there.

As a second method, a video camera or a charge-coupled device (CCD) camera always captures an observer,
There is a method of recognizing the pupil by image processing and detecting its spatial position. In this case, the head detection unit includes a video camera, an image processing / recognition device, and a position detection device.

A third method is to attach a magnetic field generator to the observer's head and use a plurality of magnetic field detectors to detect the spatial position of the magnetic field generator. In this case, the head detecting unit includes a magnetic field generator, a plurality of magnetic field detectors, a processing device for signals from the magnetic field detectors, and the like. In this method, a magnetic field detector may be attached to the observer's head and a magnetic field generator may be placed on the panel side.

Other methods include a mechanical method, a method using ultrasonic waves, and a method using inertial force.

Next, a method of following the head of the observer to control the reproduction position of the stereoscopic image and changing the reproduced stereoscopic image will be described.

In the case of photographing and displaying with a photographing system as shown in FIG. 10, the observation area is divided into two planes perpendicular to the liquid crystal panel 1 in advance and divided into three spaces S, T and U. Spaces S, T, and U are determined by the arrangement of cameras. The spaces S and T pass through the principal point of the lens of the camera 45 and are divided by a plane perpendicular to the liquid crystal panel, and the spaces T and U pass through the principal point of the camera 46 and are divided by a plane perpendicular to the liquid crystal panel. It

The position information of the midpoint of both eyes detected by the head detecting section 3 is sent to the optical characteristic variable lens control section 4. The optical characteristic variable lens control unit 4 controls the optical characteristic of the optical characteristic variable lens 2 to display the display pixel Di of the liquid crystal panel 1.
1 or the positions of the projected image P and the projected image Q of the image displayed on the display pixel Di2 are controlled. The projection positions of the projected image P and the projected image Q are controlled so that the point A at the boundary can be aligned with the midpoint of both eyes of the observer.

The operation of the variable optical characteristic lens 2 is the same as that of the above-mentioned embodiment.

Four stereoscopic signal sources 33 to 36 obtained by, for example, the above-described image pickup system as shown in FIG. 10 are connected to the stereoscopic signal selecting unit 43, and four stereoscopic signal sources are determined by the positional information of the head. One of the two is assigned to the signal for the left eye, and another one is assigned to the signal for the right eye. The stereoscopic signal synthesizing unit 42 distributes the two signals selected by the stereoscopic signal selecting unit 43 into an even field and an odd field, respectively, and displays the left-eye parallax image and the right-eye parallax image as display pixels Di1 on the liquid crystal panel 1. It is displayed on the pixel Di2.

For example, the midpoint of both eyes of the observer is now the space T.
If the boundary point A is also inside the space T (point A in FIG. 9), the image 2 is displayed on the display pixel Di1 of the liquid crystal panel 1.
, And the image 3 is displayed on the display pixel Di2. When the observer moves his / her head and the boundary point A following it moves into the space U (point A ′ in FIG. 9), the display pixel Di of the liquid crystal panel 1 is displayed.
The image 3 is displayed in 1 and the image 4 is displayed in the display pixel Di 2, and the images are exchanged.

That is, the images displayed on the liquid crystal panel 1 are switched depending on in which space the boundary point A following the position of the observer exists. Table 1 shows the relationship between the position of the boundary point A and the image to be displayed.

[0096]

[Table 1]

The position information of the head detected by the head detecting unit 3 is also sent to the stereoscopic signal selecting unit 43. Based on the position information, the stereoscopic signal selection unit 43 selects a combination of stereoscopic signal sources shown in Table 1 and sends the stereoscopic signal to the stereoscopic signal synthesis unit 42.

The size of the space T depends on the distance between the cameras of the image pickup system. In general, the distance between the cameras should match the average distance between the human eyes. Further, in order to obtain a smoother image change, the distance between the cameras may be set to half the average distance between both eyes or less. However, in that case, unless the number of cameras is increased, the stereoscopic image changes and the observable area becomes narrow.

By doing so, even if the observer moves his or her head, the stereoscopic image is reproduced at an optimum position in accordance with the position of the observer's head, and the position of the observer's head is adjusted. At the same time, the reproduced three-dimensional image changes, and a very natural three-dimensional image can be observed.

The present invention can also be applied to a projection type three-dimensional display device. FIG. 11 is a structural cross-sectional view of the projection type three-dimensional display device showing the embodiment.

In the projection type three-dimensional display device of FIG. 11, the light emitted from the light source 51 is collected by the condenser lens 53 and is incident on the liquid crystal panel 1. Light is liquid crystal panel 1
The light that has been modulated by and is transmitted by the projection lens 52 is imaged on the diffusion layer 50b in the variable optical characteristic screen 50 by the projection lens 52. That is, the image displayed on the liquid crystal panel 1 is enlarged and the diffusion layer 50
projected on b.

The variable optical characteristic screen is composed of a variable lenticular lens array 50a whose optical characteristics are electrically controlled and a diffusion layer 50b. The variable lenticular lens array 50a has the structure shown in FIG. 2 or 8. The optical characteristic of the variable lenticular lens array 50a is controlled by the variable optical characteristic screen controller 54.

Compared with the direct-view type, the projection type has only the projection lens 52 and the diffusion layer 50b between the variable lenticular lens array 50a and the liquid crystal panel 1, and there is no essential difference.

The control method of the reproduction position of the stereoscopic image and the switching method of the display image described above are applied in exactly the same manner. The head detecting unit 3, the stereoscopic signal synthesizing unit 42, the stereoscopic signal selecting unit 43, and the stereoscopic signal sources 33 to 36 have the same functions and operate in the same manner.

[0105]

According to the three-dimensional display device of the first invention,
Display means for simultaneously displaying a plurality of different parallax images, optical means mounted on the display means, comprising an array of cylindrical lenses, and capable of varying the optical characteristics of the cylindrical lenses, and the spatial position of the observer's head And a control means connected to the detection means and controlling the optical means so that the stereoscopic image is reproduced at the optimum position of the head based on the position information of the head detected by the detection means. Since the detection means detects the spatial position of the observer's head and always controls the reproduction position of the stereoscopic image to the optimum position, the optimum projected image can be presented to the observer. Then, as a means for controlling the reproduction position of the stereoscopic image,
Since a lens whose electrical characteristics can be electrically controlled is used, a precise mechanical system is not required, the response is excellent, and the three-dimensional display device can be downsized. Furthermore, since the position of the controllable three-dimensional image reproduction space can be controlled in the observation distance direction, the space that can follow the head of the observer becomes a three-dimensional space, and the degree of freedom of head movement increases.

Further, the three-dimensional display device of the second invention comprises a display means for simultaneously displaying a plurality of different parallax images,
It is connected to the display means, an optical means composed of an array of cylindrical lenses and capable of varying the optical characteristics of the cylindrical lenses, a detecting means for detecting the spatial position of the observer's head, and a detecting means. Control means for controlling the optical means so that a stereoscopic image is reproduced at the optimum position of the head based on the position information of the head detected by the detection means, and a plurality of stereoscopic signal sources for performing multi-view display And a selection unit that is connected to a plurality of three-dimensional signal sources and a detection unit and that selects a three-dimensional signal to be displayed on the display unit based on position information of the head detected by the detection unit.
The spatial position of the observer's head is detected by the detection means,
In response to this, the stereoscopic image display space formed by the twin-lens type lenticular lens is moved, and the reproduced image is selected by the selection means to which a plurality of stereoscopic signal sources for performing multi-eye display are connected, and the viewer's Present a stereoscopic image according to the position. As a result, in addition to the effect of the first invention, it is possible to present a three-dimensional image that smoothly and continuously changes according to the position of the observer's head, and observe the three-dimensional image very naturally. can do. Further, by using the rear projection type projector, in addition to the above effects, it is possible to achieve a large screen.

[Brief description of drawings]

FIG. 1 is a sectional view showing a basic configuration of an embodiment of a three-dimensional display device of the present invention.

FIG. 2 is an enlarged cross-sectional view of a structure of a variable optical characteristic lens used in the three-dimensional display device of FIG.

FIG. 3 is an explanatory diagram of a refractive index distribution of the variable optical-characteristic lens shown in FIG.

FIG. 4 is an explanatory diagram of each variable representing the optical characteristic of the cylindrical lens used in the three-dimensional display device of FIG.

5 is an explanatory diagram showing a relationship between display pixels and a projected image in the three-dimensional display device of FIG.

6 is an explanatory diagram showing a relationship between a display pixel pitch and a lenticular lens pitch in the three-dimensional display device of FIG.

7 is an explanatory diagram illustrating a relationship between a displacement amount of a relative position between a display pixel and a lenticular lens and a position of a projected image in the three-dimensional display device of FIG.

8 is an enlarged cross-sectional view of a structure of another embodiment of the variable optical characteristic lens used in the three-dimensional display device of FIG.

FIG. 9 is a sectional view showing a basic structure of a second embodiment of the three-dimensional display device of the present invention.

10 is a schematic explanatory diagram showing an example of a photographing system used in the three-dimensional display device of FIG.

FIG. 11 is a cross-sectional view showing the basic structure of a projection type three-dimensional display device.

FIG. 12 is a cross-sectional view showing a structure of a conventional three-dimensional display device.

FIG. 13 is a cross-sectional view showing a structure of a conventional head tracking three-dimensional display device.

[Explanation of symbols]

 1 Liquid Crystal Panel 2 Optical Characteristic Variable Lens 3 Head Detection Section 4 Optical Characteristic Variable Lens Control Section 33, 34, 35, 36 Stereoscopic Signal Source 42 Stereoscopic Signal Synthesizing Section 43 Stereoscopic Signal Selecting Section

Claims (4)

[Claims] 1. A display means for simultaneously displaying a plurality of different parallax images, an optical means mounted on the display means, comprising an array of cylindrical lenses, and capable of varying the optical characteristics of the cylindrical lenses, and an observer. Detecting means for detecting the spatial position of the head, and a stereoscopic image is reproduced at the optimum position of the head based on the position information of the head connected to the detecting means. And a control means for controlling the optical means. 2. A display means for displaying a plurality of different parallax images at the same time, an optical means mounted on the display means, comprising an array of cylindrical lenses, and capable of varying the optical characteristics of the cylindrical lenses, and an observer. Detecting means for detecting the spatial position of the head of the head, and a stereoscopic image is reproduced at the optimum position of the head based on the position information of the head which is connected to the detecting means and is detected by the detecting means. As described above, the control means for controlling the optical recording means, the plurality of stereoscopic signal sources for performing multi-view display, the plurality of stereoscopic signal sources and the detection means connected to the detection means and detected by the detection means A three-dimensional display device comprising: a selection unit that selects a stereoscopic signal to be displayed on the display unit based on position information of the head. 3. The three-dimensional display device according to claim 1, wherein the optical unit is made of liquid crystal. 4. A projection lens and a diffusion layer are provided between the display means and the optical means.
Alternatively, the three-dimensional display device according to claim 2.