JP2874985B2 - Lenticular multi-directional stereoscopic video device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a method of arranging a lenticular lens plate in close proximity to an image display surface and arranging the same plural pixels for each lens element. Lenticular type multi-directional stereoscopic video device that allows the stereoscopic image to be viewed from multiple directions by separately projecting the image of the left and right eyes,
Even when a dark portion exists between pixels on the image display surface, such as when a liquid crystal display is used, the configuration is appropriately arranged so that a dark portion does not occur in a stereoscopic image in the viewing area.

(Summary of the Invention) According to the present invention, a lenticular lens plate is disposed close to and opposed to an image display surface, and the same plural pixels are arranged for each lens element to separately project images in plural directions to the right and left eyes. In a lenticular type multi-directional stereoscopic video device that enables a stereoscopic image to be viewed from each direction, when a dark portion exists between pixels on the image display surface, the focal length of the lenticular lens plate falls within the range. By arranging the image display surface and diffusing the transmitted light of the lenticular lens plate, the transmitted light of the images in each direction does not overlap each other, and the lens system is designed so as to compensate for the dark area between pixels. While maintaining the basic structure of the Cura lens plate as before, the dark space is not generated in the stereoscopic viewing area to increase the degree of freedom of the viewing area, and in the area where almost good viewing is possible. This is to prevent the black band of the screen division from occurring in the stereoscopic video.

(Prior Art) In general, as shown in FIG. 1 (a), a lenticular type multi-directional stereoscopic image display includes a lenticular lens plate 1 in which a large number of cylindrical lenses are closely arranged in parallel to each other. 2 is disposed close to and opposed to the image display surface 2 so that stereoscopic images can be viewed by viewing the pixels on the display surface 2 with an appropriate distance on the lens surface side.

Thus, in the configuration example of the stereoscopic video apparatus shown in FIG. 1A, as shown in a partially enlarged manner in FIG. 1B, each cylindrical lens element 11 of the lenticular plate 1 is provided. , About four identical pixels L1 to L4 on the display surface 2, for example.
Are arranged in a direction perpendicular to the lens cylinder axis, corresponding to four directions. Therefore, 4 on the image display surface 2
Light from the display pixels L1, L2, L3, L4 in the directions is transmitted through the corresponding lens elements 11 on the lenticular plate 1 and emitted to the corresponding optical paths 51, 52, 53, 54, respectively. As a result, when the pupils of the left and right eyes of the observer are located in any of the optical paths 51 to 54, for example, the ellipse 55 shown in FIG.
Or the viewer's head is placed at the position indicated by 56, and the pupils of the left and right eyes are located in the optical paths 51, 52 or 52, 54, respectively, corresponding to the two pixels L1, L2 or L2, L4 respectively The two pixels L1, L2 or L
Since the L2 and L4 images are projected separately from each other,
The four-directional pixels L1 to L4 corresponding to 11 can be stereoscopically viewed.

In addition, in FIG. 1A, the cylindrical lens element 11 of the four-direction pixels L1 to L4 shown in FIG.
To obtain the most appropriate viewing state in which two adjacent pixels, for example, L1 and L2 can be stereoscopically viewed at an appropriate viewing distance, the viewer's head is elliptical.
The area 57 where the left eye pupil should be located when placed near 55
Is indicated by a left-downward oblique line shading, and an area 58 in which the pupil of the right eye should be located is indicated by a right-downward oblique line shadow. In addition, in order to obtain a viewing state in which every other two pixels, for example, L2 and L4, among the four direction pixels L1 to L4 can be stereoscopically viewed, the viewer's head is formed into an elliptical shape.
The areas where the pupils of the left and right eyes should be located when placed near 56 are indicated by the same diagonal shading as described above.

Further, if the relationship between the lens element pitch and the lens thickness in the lenticular plate 1 and the pixel pitch on the display surface 2 is appropriate, the display transmitted through the other lens element 12 separated from the lens element 11 in the lenticular plate 1 Face 2
The emission light path of light from the other pixels such as L12 and L22 above, and the emission light path of light from the pixels L1 and L2 transmitted through the lens element 11,
In the state where the left and right eyes pupils are located in the thick line ranges 59 and 60 when the two pixels coincide with each other in the range indicated by the thick lines 59 and 60 in the figure, each two pixels transmitted through the lens elements 11 and 12 are separated into the left and right eyes respectively. The images are projected and both can be stereoscopically viewed, and if this state extends over the entire surface of the display surface 2, the image on the display surface 2 can be stereoscopically viewed.

With respect to the lenticular plate based on the above-described operation principle in the lenticular type multidirectional stereoscopic image device having the above-described configuration, complex pixels arranged for each lens element are arranged in each radiation direction to each radiation angle of a light beam. Conventionally, in order to perform the separation conversion, the image display surface 2 is conventionally arranged and arranged so as to coincide with the rear focal plane of each cylindrical lens in the lenticular plate 1. Such a configuration and arrangement is not conventionally used when the display image is a photographed image or the image display is a cathode ray tube display and the display image on the display surface 2 is a continuous image display. There was no problem.

However, when a pixel display in which rectangular pixels are closely arranged in a grid, such as a liquid crystal display in which an agent is generally filled in a rectangular frame, is used as the image display 2, the mutual connection of each pixel on the display surface 2 is made. A non-light-emitting dark portion always exists between them. As a result, as shown in FIG.
A dark area is generated between the light paths from L1 to L4, and as shown in FIG. 1A, the light paths from the four-direction pixels L1 to L4
Dark areas B1 to B4 are formed between 51 to 54, and if the viewer's eyes enter the dark areas, stereoscopic vision becomes impossible. Therefore, the diagonally shaded areas 57 and 58 described above, in which the pupils of both eyes should be located in order to enable stereoscopic vision, are limited to extremely narrow areas as shown in the figure due to the existence of such dark areas. become.

In order to eliminate such a limitation of the stereoscopically viewable region, basically, the dark region is located between the emission light paths from the pixels in each direction, regardless of the presence of the non-light-emitting dark region on the display surface 2.
It must be prevented from occurring.

Furthermore, the lens pitch of the lenticular plate 1 is displayed at a quasi-optimal viewing distance that is farther away than the optimal viewing distance at which proper stereoscopic viewing is possible as shown in FIG. Since the pixel pitch of the surface 2 slightly shifts with an increase in the viewing direction angle, a black band-like dark portion due to the presence of the inter-pixel dark portion on the display surface 2 appears on the viewing screen.
The number of pixel directions for each lens element −1, 4-1 = 3 in the illustrated example
The viewing screen is divided in the horizontal direction into the area of, and the stereoscopic images in the adjacent viewing directions are simultaneously viewed.

In order to solve such an inconvenient problem in stereoscopic vision, the following method has conventionally been adopted.

That is, in principle, the lenticular plate used in this kind of multidirectional stereoscopic image device, as generally used for a transmission type lenticular projection screen,
On the display surface 2 side of the lenticular lens plate 1 shown in FIG. 1 (a), another lenticular plate having a cylindrical lens surface facing the display surface 2 is superimposed, and the mating surface is used as an image forming surface. There was a solution to the problem using a double lenticular plate.

In such a conventional problem solving method, as shown in FIG. 2, a lenticular lens plate 1 having a cylindrical lens surface directed to a radiation side is configured in exactly the same manner as in FIG. The lens pitch is made equal to the pixel pitch on the display surface 2, and an enlarged image is formed so that the width of the pixel image formed on the mating surface of both lenticular plates is exactly equal to the pixel pitch on the display surface 2. if,
As shown in FIGS. 1 (a) and 1 (b), the dark areas B1 to B4 interposed in the emission light paths of the pixels L1 to L4 are eliminated.

(Problems to be Solved by the Invention) However, in the multidirectional three-dimensional image apparatus having the single lenticular lens plate 1 shown in FIG. However, a dark area where the display surface cannot be viewed even when the image is located is generated, and a stereoscopically viewable area is limited. In a multidirectional stereoscopic video device configured by a double lenticular plate, the pixel pitch of the display surface is An extra lenticular lens plate having an exactly equal lens pitch must be provided so that each pixel and each lens element are accurately opposed to each other. Therefore, not only is it extremely difficult to manufacture and assemble, but also In some cases, the rate has decreased, and in some cases, a virtual image due to side emission has occurred.

Therefore, each of the conventional lenticular type multi-directional stereoscopic image devices has a difficult problem to be solved.

(Means for Solving the Problems) It is an object of the present invention to solve the above-mentioned conventional problems and to use only a single lenticular lens plate, appropriately configure and properly arrange the lens plate itself. Accordingly, a lenticular type multi-directional stereoscopic video apparatus that eliminates the occurrence of a dark area based on the presence of inter-pixel dark areas on the image display surface in the stereoscopic image viewing area and increases the degree of freedom of the stereoscopic viewable area configuration is provided. To provide.

That is, the lenticular type multi-directional stereoscopic video device of the present invention is a stereoscopic video device in which a lenticular lens plate is arranged to face an image display surface so that stereoscopic video can be viewed from multiple directions. In the case where a dark portion is interposed between the pixels, the image display surface is arranged within the focal length of the lenticular lens plate and light transmitted through the lenticular lens plate is diffused to the viewing area. The pixel and the lenticular are matched so that a dark portion does not occur.

(Operation) Therefore, in the lenticular type multi-directional stereoscopic image apparatus of the present invention, a single lenticular lens plate is used instead of using a double lenticular plate which is difficult to manufacture and adjust as in the related art. With a simple configuration, just by appropriately arranging the image display surface so as to oppose it, even when a non-light emitting dark portion is interposed between the pixels on the display surface, a dark portion region where the display image cannot be viewed is displayed in the stereoscopic image viewing region. Thus, the degree of freedom of the stereoscopically viewable region can be significantly increased as compared with the related art, without causing the occurrence of a black band that divides an image on the viewing screen.

(Example) Hereinafter, the present invention will be described in detail with reference to the drawings with reference to examples.

Thus, the basic operation principle of the lenticular type multi-directional stereoscopic video apparatus of the present invention is as shown in FIG.
The direction pixel L2 side boundary line indicated by the solid line of the light ray transmitted through the lens element 11 from the upper direction pixel L1, and the direction indicated by the dotted line of the light ray path of the light ray transmitted from the direction pixel L2 through the lens element 11 Conventionally, when the pixel L1 side boundary line passes through the illustrated end portion of the lens element 11, the respective light rays are parallel to the solid line direction and the dotted line direction passing through the node of the lens element 11, respectively. For this reason, in contrast to the conventional dark area shown with diagonal shading, which occurs near the appropriate viewing distance, in the present invention, the pixel display surface 2 is provided with the lens element 11.
, The pixels L1, L
Each of the light rays from the direction pixel L1 is slightly diffused and emitted, and the direction pixel L2 side boundary line of the emission light path from the direction pixel L1 is expanded to L1N shown by a dashed line, and the direction pixel L1 side boundary line of the emission light path from the direction pixel L2. Is extended to L2N indicated by a two-dot chain line, and at least in the vicinity of a suitable viewing distance, a dark area that has conventionally occurred is eliminated.

Although the operating principle of the dark area elimination according to the present invention deviates from the operating principle of lenticular type stereoscopic image viewing, in practice, each pixel on the display surface has a finite width. The radiation path from each pixel is originally
Since the radiation direction has a permissible range corresponding to the pixel width, even if the radiation optical path is diffused into a region corresponding to the permissible range, the conditions for viewing a stereoscopic image should not be impaired.

Further, since the resolution of the lenticular type stereoscopic image device is determined by the lens pitch of the lenticular lens plate, the stereoscopic image device of the present invention in which light rays from pixels in each direction are diffused and emitted as described above. There is no degradation of resolution in the three-dimensional image.

As can be seen from the above description, the configuration and arrangement of the lenticular type multi-directional stereoscopic image apparatus of the present invention is as shown in FIG.
This is almost the same as the principle configuration and arrangement of this type of device schematically shown in (b), except that the relative distance between the lenticular lens plate 1 and the image display surface 2 is slightly different to the extent that it cannot be shown. . Although each lens element of the lenticular lens plate 1 has been described above as a cylindrical lens,
As long as the aberration is small, there is no change in the above-described operation principle of the three-dimensional image apparatus of the present invention even if the lens is an elliptic cylindrical lens.

Here, the aspect of the stereoscopic image viewing operation in the lenticular multi-directional stereoscopic image device of the present invention based on the above-described operation principle will be described. In the lens use condition in which the ray angle is wide as in the stereoscopic image device of the present invention. Of the various optical design methods, aberrations increase when a lens design using paraxial rays is used.Therefore, the ray tracing method using computer graphics can be used to effectively operate the multidirectional stereoscopic image apparatus of the present invention. Since it can be clarified, the operation of the apparatus of the present invention by the ray tracing method will be described below.

First, in a lenticular type multi-directional video apparatus having a configuration schematically shown in FIGS. 1A and 1B, an image display surface 2 is arranged on a focal plane of a lenticular lens plate 1 as in the related art. In the case of using a lenticular lens plate in which the curvature of the cylindrical lens and thus the focal length and the thickness of the lens are designed, the light rays transmitted through the lens elements 11 and 12 from the pixels in each direction of the display surface 2 are used. FIG. 4 (a) shows the result of tracing each optical path, and FIG. 4 (b) shows the result of tracing the optical path of light rays corresponding to one lens element. A dark area as described with reference to FIG. 1A is generated between the respective optical paths in the conventional device.

In the lenticular type multidirectional stereoscopic video apparatus in such an operation state, when the thickness of the lenticular lens plate 1 is not changed, the focal length is increased, and when the focal length is not changed, the thickness is shortened. When the image display surface 2 is positioned within the focal length of the lenticular lens plate 1, light rays from each pixel of the image display surface 2
After being transmitted through each lens element of the lenticular lens plate 1, the light is diffused and radiated, and as shown in FIG. 5 (a), the transmission of one lens element on the image display surface 2 from the four-direction pixels L1 to L4. At least in the vicinity of the suitable viewing distance, the diffusion paths of the light rays are not closely overlapped with each other, and furthermore, a condition that does not cause a dark area between them can be obtained by the ray tracing method. FIG. 5B is an enlarged view of the vicinity of the lens element in such a state shown in FIG.

The matching between the pixel pitch and the distance between the pupils and the matching between the pixel pitch and the lens pitch necessary for realizing such a diffuse radiation state in the multidirectional stereoscopic image apparatus of the present invention are separately calculated as follows.

That is, the thickness of the lenticular lens plate 1 is xt,
The refractive index n _i of the lenticular lens plate 1, the pixel pitch e _p of the image display panel 2, the number in the direction between the pupil m, the number of direction pixel of each lens Motogoto in the image display panel 2 n _e, air F = xt / n _i , pupil distance a
When, the preferred viewing distance _{x p = a · (xt /} n i) / (e p · m) lenticular pitch _{l p = n e · e p} · x p / (x p + xt / n i).

Incidentally, the focal length of the lenticular lens plate 1 in the lenticular type multi-directional stereoscopic video apparatus is made shorter than the conventional state shown in FIG.
Even when the image display surface 2 is positioned outside the focal length of the lenticular lens plate 1, light rays from pixels in each direction of the display surface 2 are transmitted through the lenticular lens plate 1,
The light is once converged at a short distance and then diffusely radiated. However, since the order of the radiation directions of the light rays from the pixels in each direction is reversed, the diffuse irradiation in such a state cannot be adopted.

After all, the lenticular and
If the lens plate 1 and the image display surface 2 are configured and arranged, a multi-directional stereoscopic image can be viewed in a state where no dark area is interposed between the emission light paths from the pixels. A black band that splits the screen in the horizontal direction, which has been generated based on the shift between the lens pitch and the pixel pitch, to a stereoscopic image of a quasi-optimal viewing distance that could have been viewed almost satisfactorily from a distance, It disappears in the above-described configuration and disappears.

Note that, for example, when a multidirectional image is projected on a transmission screen by a liquid crystal image display or the like, a lenticular lens plate is superimposed on the rear surface of the screen, and a stereoscopic image is viewed in multiple directions on the rear side. When the above-described configuration according to the present invention is applied by regarding the back surface of the die screen as an image display surface, a continuous stereoscopic image in which a dark portion region based on the intervening non-light emitting region between pixels in a liquid crystal image display or the like is similarly eliminated. Images can be viewed.

(Effects of the Invention) As is clear from the above description, according to the present invention, a lenticular lens plate is superimposed on the display surface of an image display such as a liquid crystal image display where a non-light emitting region is interposed between pixels. When viewing a stereoscopic image from multiple directions, in such a conventional stereoscopic video device, a dark area where the image is not visible to the viewer's eyes occurs in the stereoscopic image viewing area, or a black band that separates the screen The remarkable effect of improving the degree of freedom in viewing a continuous stereoscopic image is obtained by eliminating any of the above, and a double lenticular plate is used to eliminate such dark areas as in the past. The remarkable operation and effect can be easily realized by only slightly changing the configuration of the single lenticular lens plate without the use of the lens.

[Brief description of the drawings]

1 (a) and 1 (b) are diagrams showing the operation principle of a conventional lenticular type multidirectional stereoscopic image apparatus and its one lens element, respectively, and FIG. 2 is a diagram showing a double lenticular type multidirectional stereoscopic image apparatus. FIG. 3 is a diagram showing the principle of operation of the lenticular multi-directional stereoscopic video apparatus of the present invention; FIGS. 4 (a) and (b) are conventional stereoscopic video apparatuses and one lens element thereof; 5 (a) and 5 (b) are diagrams respectively showing an example of a diffused radiation path of one lens element in the stereoscopic image apparatus of the present invention and an example in which a part thereof is enlarged. . 1 Lenticular lens plate 11, 12 Lens element 2, Image display 51-54 Radiation light path 55, 56 Head position 57, 58 Stereoscopic image viewing area 59 60 stereoscopic image viewing position L1 to L4 direction pixel, B1 to B4 dark area L12, L22 emission light paths of other lens elements L1N, L2N diffuse light path

Claims (1)

(57) [Claims] 1. A stereoscopic video apparatus in which a lenticular lens plate is arranged opposite to an image display surface so that stereoscopic images can be viewed from multiple directions, wherein a dark portion is interposed between pixels on the image display surface. In such a case, the image display surface is disposed within the focal length of the lenticular lens plate, and the transmitted light of the lenticular lens plate is diffused so that the pixel and the lenticule are prevented from forming a dark portion in the viewing area. A lenticular multi-directional stereoscopic video apparatus characterized by matching the curas.