JPH09197343A - 3D image display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the resolution that LCD itself has from decreasing by varying the distance between an image display plane which is transferred by a 2nd optical means and a 1st optical means. SOLUTION: A lenticular sheet 2 as the 1st optical means has a plane as its one surface and convex cylindrical lenses arrayed periodically on the other surface in the right and left direction, and the convex surface is directed to the LCD 10, thereby stereoscopically reproducing image information displayed on the LCD 10. An actuator 5 moves the lenticular sheet 2, and a control circuit 6 controls the operation of a control circuit 5 with an external input switching means. Further, a fiber face plate 3 as a 2nd optical means is provided on the side where the substrate glass 12 of a liquid crystal layer 11 is not provided and consists of an optical element with a periodic structure. And, the distance between the image display plane which is transferred by the 2nd optical means and the 1st optical means is varied.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and apparatus for stereoscopic image display without glasses using a lenticular lens or the like, and more particularly to a stereoscopic image display apparatus capable of switching between two-dimensional image display and three-dimensional image display. .

[0002]

2. Description of the Related Art Conventionally, as a method of displaying a stereoscopic image, a stereoscopic image display method using a lenticular lens sheet (hereinafter referred to as "lenticular method") has been widely known.

For the lenticular system, 1970
Since then, it has been actively researched, and the results are, for example, Oplu.
sE magazine, November 1993, pages 100-104.

FIG. 5 is a diagram showing a stereoscopic image display example by a conventional lenticular stereoscopic image display device.

As shown in FIG. 5, this conventional example has a structure in which an LCD 510 for displaying image information and a cylindrical lens having a flat surface on one side and a convex shape on the other surface are periodically arranged in the left-right direction. When the side is in close contact with the LCD 510, L
The CD 510 is mainly composed of a lenticular sheet 502 that three-dimensionally reproduces the image information displayed on the CD 510. The LCD 510 includes a liquid crystal layer 511 that displays image information by liquid crystal and two liquid crystal layers 511 sandwiching the liquid crystal layer 511. Substrate glass 512, a backlight light source 514 that emits light to the liquid crystal layer 511 to output image information in the liquid crystal layer 511, and two substrate glasses 512 on the side not in contact with each liquid crystal layer 511. It is provided with a backlight light source 514 and a polarizing plate 513 that polarizes light that has passed through the liquid crystal layer 511.

The stereoscopic image display operation in the stereoscopic image display device configured as described above will be described below.

First, two parallax images A and B taken from different left and right viewpoints are divided into stripes and extracted, which are alternately arranged to form a composite stripe image.

Next, the composite stripe image is displayed on the LCD 510.
Will be displayed.

Next, the luminous fluxes from the pixel A group and the pixel B group which form the stripe image displayed on the LCD 510 are incident on the lenticular sheet 502 by the light emitted from the backlight light source 514.

After that, in the lenticular sheet 502, due to the refraction of the convex surface, the light fluxes from the pixel A group and the pixel B group respectively correspond to the left and right eyes LE and R of the observer.
It is incident on E.

By the series of operations described above, the observer observes the original parallax image with each eye, and the stereoscopic vision is realized.

[0012]

However, in the conventional stereoscopic image display device as described above, one of a pair of adjacent pixels is guided to the right eye and the other to the left eye to display a three-dimensional image. When displaying a two-dimensional image, the display contents of pairs of adjacent pixels must be the same, so the resolution at the time of displaying the two-dimensional image is lower than the resolution of the LCD itself. There is a point.

For example, in the stereoscopic image display device shown in FIG. 5, pixels B1 and A2 in the composite stripe image,
Since the display contents of B3 and A4 must be the same, the resolution in the left-right direction is reduced to 1/2 of the resolution of the LCD itself.

The present invention has been made in view of the problems of the above-described conventional technique. Even when a two-dimensional image is displayed, the resolution is lowered with respect to the resolution of the LCD itself. An object is to provide a stereoscopic image display device with a small number.

[0015]

In order to achieve the above object, the present invention provides an image display means for displaying image information and a three-dimensional display by refracting an image displayed on the image display means. In the stereoscopic image display device having one optical unit and capable of switching between two-dimensional image display and three-dimensional image display, the three-dimensional image display device is provided between the image display unit and the first optical unit, Second optical means for transferring the image information displayed on the display means, an image display surface transferred by the second optical means, and the first optical means.
And a control means for changing the distance from the optical means.

Further, the control means changes the distance between the image display surface transferred by the second optical means and the first optical means by moving the first optical means. And

Further, when performing a three-dimensional image display, the control means sets the distance between the image display surface transferred by the second optical means and the main plane of the first optical means to the first plane. It is characterized in that it is made substantially equal to the focal length of the optical means.

Further, when the two-dimensional image display is performed, the control means makes the image display surface transferred by the second optical means substantially coincide with the main plane of the first optical means. And

Further, the second optical means is an optical element having a periodic structure.

(Operation) In the present invention configured as described above, when the control means performs the three-dimensional image display, the image display surface transferred by the second optical means and the first optical means are transferred. The first optical means is moved so that the distance from the main plane is approximately equal to the focal length of the first optical means,
When performing the three-dimensional image display, the first optical unit moves so that the image display surface transferred by the second optical unit and the main plane of the first optical unit are substantially aligned with each other.

When the distance between the image display surface transferred by the second optical means and the main plane of the first optical means becomes substantially equal to the focal length of the first optical means, the image is displayed on the image display means, The image transferred by the second optical means is refracted in the first optical means to display a three-dimensional image,
When the image display surface transferred by the second optical means and the main plane of the first optical means are substantially coincident with each other, the refracting power of the first optical means becomes almost 0, and a two-dimensional image is displayed.

[0022]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings.

(First Embodiment) FIG. 1 is a diagram showing a first embodiment of a stereoscopic image display apparatus according to the present invention.
(A) is a figure which shows a three-dimensional image display, (b) is a figure which shows a two-dimensional image display.

As shown in FIG. 1, the present embodiment has a structure in which an LCD 10 for displaying image information and a cylindrical lens having a flat surface on one side and a convex surface on the other side are periodically arranged in the left-right direction. The lenticular sheet 2 which is the first optical means for stereoscopically reproducing the image information displayed on the LCD 10 with the surface facing the LCD 10, the actuator 5 for moving the lenticular sheet 2, and the switching signal input from the outside. Is mainly composed of a control circuit 6 for controlling the operation of the actuator 5 by
Is provided on a side of the liquid crystal layer 11 where the substrate glass 12 is not provided, a liquid crystal layer 11 which is an image display unit for displaying image information by liquid crystal, a substrate glass 12 provided on one surface of the liquid crystal layer 11, Fiber face plate 3 which is the second optical means including an optical element having a periodic structure
A backlight light source 14 which emits light to the liquid crystal layer 11 to output image information in the liquid crystal layer 11, and the substrate glass 1
2 and the fiber face plate 3 are provided on the sides that are not in contact with the liquid crystal layer 11 and that polarize the light that has passed through the backlight light source 14 and the liquid crystal layer 11.
It is composed of At present, the thickness of the substrate glass 12 of the LCD 10 having a screen size of 10 inches is 1.
Since 1 mm is mainly used, even if the substrate glass 12 is replaced by the fiber face plate 3 as in the LCD 10 of this embodiment, the polarized light can be maintained, and a display image similar to that of a normal LCD can be obtained.

FIG. 2 is a diagram for explaining the relationship between the shape and the arrangement of the lenticular sheet 2 shown in FIG.

The radii of curvature of the individual lens surfaces R1 and R2 constituting the lenticular sheet 2 are r1 and r2, respectively.
If the refractive index of the material of the lenticular sheet 2 is n,
The refractive power φ1 due to the lens surface R1 and the refractive power φ2 due to the lens surface R2 are as follows: φ1 = (n−1) / r1 (Equation 1) φ2 = (1-n) / r2 (Equation 2) expressed.

If the surface distance between the lens surface R1 and the lens surface R2 is d, the refracting power Φ of the lenticular lens 2 will be described.
Is represented by Φ = φ1 + φ2-e · φ1 · φ2 ... (Formula 3).

Here, e is the air equivalent distance of d, and e
= D / n.

Further, the distances Δ and Δ ′ from the vertices of the lens surfaces R1 and R2 to the respective principal planes H and H ′ are expressed by the following equations, respectively.

Δ = R1H = e · φ2 / Φ (Equation 4) Δ ′ = R2H ′ = − e · φ2 / Φ (Equation 5) At this time, the pixel pitch is P and the observation distance is L , Where the eye-to-eye distance of the observer is e, and the pitch p of the lenticular lens 2 is p = 2 · P · L / (e + L) (Equation 6), a pixel displaying an image from a specific viewpoint It is configured so that all the light of the group is guided to the corresponding viewpoint position of the observer.

At this time, if the distance t from the image display position to the principal plane H of the lenticular sheet 2 is set to be the focal length F (= 1 / Φ) of the lenticular sheet, the divergent light flux from the pixels is observed as substantially parallel light. To the left and right eyes of the person.

Further, if the image display position and the main plane H of the lenticular sheet 2 are made to substantially coincide with each other, the refracting power of the lenticular sheet 2 will be made substantially ineffective.

FIG. 3 is an enlarged view of a main part of the fiber face plate 3 shown in FIG.

As shown in FIG. 3, the fiber face plate 3 is formed by densely bundling the fibers 30 including the core portion 31 and the clad portion 32, and an image is displayed on one end surface of the fiber face plate 3. Then, the display light of the image is transmitted through the fiber 30, and the same image is formed on the other end face with the resolution of the diameter of the fiber 30.

The image display operation by the stereoscopic image display device shown in FIG. 1 will be described below.

The image displayed on the liquid crystal layer 11 of the LCD 10 is illuminated by the light emitted from the backlight light source 14 onto the fiber face plate 3 which is an image transmitter, and passes through the inside of the fiber face plate 3 to form the fiber face plate 3. It is displayed on the end surface of the plate 3 opposite to the liquid crystal layer 11.

That is, it can be considered that the image display surface is not the surface of the liquid crystal layer 11 which was originally the image display surface, but the end surface of the fiber face plate 3 opposite to the liquid crystal layer 11.

Here, since the lenticular sheet 2 in this embodiment is arranged with the LCD 10 side as a convex surface and the opposite side as a flat surface, r2 in the above (formula 2) is used.
= ∞, which results in φ2 = 0,
Further, according to (Equation 1), Φ = φ1.

Substituting this into (Equation 4), Δ = 0.

That is, the principal plane H of the lenticular sheet 2
The position of corresponds to the vertex of the convex surface.

Thus, as shown in FIG. 1A, the distance t from the end face of the fiber face plate 3 which is the image display surface to the main plane H of the lenticular sheet 2 is
When the distance is equal to the focal length of the lenticular sheet 2, stereoscopic viewing similar to that of a conventional lenticular stereoscopic image display device can be performed.

Further, as shown in FIG. 1B, when the convex surface of the lenticular sheet 2 is brought into close contact with the polarizing plate 13 on the front surface of the fiber face plate 3 on which an image is displayed, the thickness of the polarizing plate 13 is reduced. Since it is quite thin, the refractive power of the lenticular sheet 2 can be made almost zero.
Therefore, with such an arrangement, both the light from the pixel L portion and the light from the pixel R portion displayed on the LCD 10 are guided to both eyes R and L of the observer, and both eyes are displayed on the image display surface. It is possible to see all the pixels above. Therefore,
Unlike the conventional stereoscopic image display device, it is not necessary to display the same image on a pair of adjacent R pixel and L pixel, and LC
It is possible to display an image with little deterioration with respect to the resolution of D10.

(Second Embodiment) FIG. 4 is a diagram showing a second embodiment of the stereoscopic image display device of the present invention.
(A) is a figure which shows a three-dimensional image display, (b) is a figure which shows a two-dimensional image display.

As shown in FIG. 4, the present embodiment has a structure in which an LCD 110 which is an image display means for displaying image information and a cylindrical lens whose one surface is flat and the other surface is convex are periodically arranged in the left-right direction. The lenticular sheet 10 which is an optical unit having a plane facing the LCD 110 and stereoscopically reproducing the image information displayed on the LCD 110.
2, and between the lenticular sheet 102 and the LCD 110, the R pixel group and the L pixel group that form the stripe image displayed on the LCD 110 are imaged in an erect equal size for each pixel, and the R ′ pixel group and Gradient Index Type Lens Array 1 Forming Imaging Surface 104 Consisting of L ′ Pixel Group
33, an actuator 105 for moving the lenticular sheet 102, and a control circuit 10 for controlling the operation of the actuator 105 by a switching signal input from the outside.
The LCD 110 includes a liquid crystal layer 111 for displaying display image information by a liquid crystal, and a liquid crystal layer 1.
Two substrate glasses 112 sandwiching 11 are provided, a backlight light source 114 that emits light to the liquid crystal layer 111 to output image information in the liquid crystal layer 111, and liquid crystals of the two substrate glasses 112. The backlight light source 114 and the liquid crystal layer 111 which are provided on the side not in contact with the layer 111
And a polarizing plate 113 that polarizes the light that has passed through.

The image display operation by the stereoscopic image display device shown in FIG. 4 will be described below.

The R pixel group and the L pixel group forming the stripe image displayed on the liquid crystal layer 111 of the LCD 110 are each a gradient index lens array 133 for each pixel.
Thus, an erecting equal-magnification image is formed, and an image forming surface 104 including the R ′ pixel group and the L ′ pixel group is formed.

Here, when displaying a three-dimensional image,
As shown in FIG. 4A, if the distance t from the image plane 104 to the principal plane H of the lenticular sheet 102 is equal to the focal length of the lenticular sheet 102,
Due to the refracting power of the lenticular sheet 102, light rays from the R ′ pixel group on the image plane 104 are reflected by the right eye R of the observer.
The light rays from the L ′ pixel group are guided to the left eye LE of the observer.

Further, as shown in FIG. 4B, if the distance from the principal plane H of the lenticular sheet 102 to the image plane 104 on which an image is displayed is almost 0, the refractive power of the lenticular sheet 102 is reduced. It can be almost zero. Therefore, with such an arrangement, the LCD 110
Both the light from the pixel L portion and the light from the pixel R portion displayed on are guided to both eyes RE and LE of the observer, and both eyes can see all the pixels on the image display surface. Is. Therefore, it is possible to display an image with a resolution similar to that of a normal two-dimensional image display device.

Further, according to this embodiment, since it is not necessary to use the special LCD panel as shown in the first embodiment, the cost for the LCD panel manufacturing process can be reduced.

[0050]

As described above, according to the present invention, the second optical means for transferring the image information displayed on the image display means, the image display surface transferred by the second optical means and the first optical means. When three-dimensional image display is performed by providing control means for changing the distance from the means, the first image is displayed on the image display means and transferred by the second optical means so that the image is refracted by the first optical means. The first optical means moves to a position where the distance between the image display surface transferred by the second optical means and the principal plane of the first optical means becomes substantially equal to the focal length of the first optical means, and the two-dimensional image is moved. When displaying, the image display surface transferred by the second optical means and the main plane of the first optical means are substantially aligned with each other so that the refracting power of the first optical means becomes substantially zero. The structure in which the optical unit 1 moves Due to the two-dimensional image display and the three
Switching to three-dimensional image display is possible, and even in the case of performing two-dimensional image display, it is possible to obtain an image in which the resolution is not much lower than the resolution of the LCD itself.

[Brief description of drawings]

FIG. 1 is a diagram showing a first embodiment of a stereoscopic image display device of the present invention, in which (a) is a diagram showing a three-dimensional image display,
(B) is a diagram showing a two-dimensional image display.

FIG. 2 is a diagram for explaining the relationship between the shape and arrangement of the lenticular sheet shown in FIG.

FIG. 3 is an enlarged view of a main part of the fiber face plate shown in FIG.

FIG. 4 is a diagram showing a second embodiment of the stereoscopic image display device of the present invention, (a) showing a three-dimensional image display,
(B) is a diagram showing a two-dimensional image display.

FIG. 5 is a diagram showing a stereoscopic image display example by a conventional lenticular stereoscopic image display device.

[Explanation of symbols]

 1,101 Stereoscopic image display device 2,102 Lenticular sheet 3 Fiber face plate 5,105 Actuator 6,106 Control circuit 10,110 LCD 11,111 Liquid crystal layer 12,112 Substrate glass 13,113 Polarizing plate 14,114 Backlight light source 30 fiber 31 core part 32 clad part 104 imaging surface 133 gradient index lens array

Claims (5)

[Claims] 1. An image display means for displaying image information, and a first optical means for displaying a three-dimensional image by refracting an image displayed on the image display means. In a stereoscopic image display device capable of switching between three-dimensional image display, a second optical device that is provided between the image display device and the first optical device and transfers image information displayed on the image display device. A three-dimensional image display device comprising: means and a control means for changing a distance between the image display surface transferred by the second optical means and the first optical means. 2. The three-dimensional image display device according to claim 1, wherein the control unit moves the first optical unit to transfer the image display surface transferred by the second optical unit and the first optical unit. A stereoscopic image display device, characterized in that the distance from the optical means is changed. 3. The stereoscopic image display device according to claim 1, wherein the control unit and the image display surface transferred by the second optical unit when performing a three-dimensional image display. First
The stereoscopic image display device is characterized in that the distance from the main plane of the optical means is substantially equal to the focal length of the first optical means. 4. The three-dimensional image display device according to claim 3, wherein the control unit and the first image display surface transferred by the second optical unit when performing two-dimensional image display.
A stereoscopic image display device, characterized in that the main plane of the optical means is substantially coincident with the main plane. 5. The stereoscopic image display device according to claim 1, wherein the second optical unit is an optical element having a periodic structure.