JP2000050314A - Stereoscopic display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a practical stereoscopic display device that displays a simple three-dimensional image with a simple structure without using an eyeglass or the like. SOLUTION: The display device is provided with a flat LED array 13, a 1st liquid crystal reflection plate 11 consisting of a polarization plate, a reflection polarization plate and a liquid crystal display element provided between the polarization plate and the reflection polarization plate, a fixed reflection plate 16, many 2nd liquid crystal reflection plates 15 laminated between the fixed reflection plate 11 and the 1st liquid crystal reflection plate 11 and consisting of liquid crystal display elements and reflection polarization plates, and a beam splitter 12 placed between the 1st liquid crystal reflection plate and the planer LED array. The flat LED array emits a light to each cut face image formed by segmenting sequentially a three-dimensional displayed object from its end, and the 1st liquid crystal reflecting plate, the many 2nd liquid crystal reflection plates and the fixed reflection plate that reflect the emitted light are sequentially selected synchronously with the respective cut-face images.

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, and more particularly to a three-dimensional display device for displaying a three-dimensional image by superposing and stacking a plurality of two-dimensional images displayed on a two-dimensional display panel.

[0002]

2. Description of the Related Art As a conventional stereoscopic display device, for example, a device using liquid crystal shutter glasses shown in FIG. 6 is known. In the apparatus shown in FIG. 6, first, the three-dimensional object 5 is viewed from different directions.
In order to obtain a so-called parallax image of the image 1, a three-dimensional object 51 is provided by two cameras 52 and 53 installed at a predetermined interval.
Is imaged. Next, the video signal converter 54 synthesizes the two-dimensional images such that the two-dimensional images captured by the cameras 52 and 53 are alternately arranged for each field. The video signal conversion device 54 displays the synthesized two-dimensional image on the two-dimensional display device 55, and when displaying the two-dimensional image captured by the camera 52, the liquid crystal shutter glasses 56.
Among them, the liquid crystal shutter on the left side of the observer 57 is set to the transmitting state, and the right side is set to the non-transmitting state. On the other hand, when the two-dimensional image captured by the camera 53 is displayed on the two-dimensional display device 55 by the video signal conversion device 54, the liquid crystal shutter on the right side of the observer 57 in the liquid crystal shutter glasses 56 is set in a transmissive state, and The liquid crystal shutter in the non-transmission state. By repeating the above-described operation, the observer 57 feels as if they are simultaneously viewing the parallax image with both eyes due to the afterimage effect of the eyes, so that stereoscopic viewing with binocular parallax can be performed.

As another three-dimensional display device using no glasses or the like, for example, a three-dimensional display device using a well-known lenticular lens plate shown in FIG. 7 is known. In this apparatus, first, a parallax image of a three-dimensional object 51 is formed by cameras 52,
An image is taken at 3. Next, from the two two-dimensional images captured by the cameras 52 and 53, the video signal conversion unit 54 synthesizes a two-dimensional image in which pixels in the horizontal direction are alternately arranged for each pixel. The video signal converter 54 causes the two-dimensional display device 55 to display the synthesized two-dimensional image. At this time, by placing the lenticular lens plate 58 in close contact with the display surface side of the two-dimensional display device 55, the lenticular lens plate 5
8 has directivity, and depending on the position of the observer 57, the camera 52
In addition, only the pixels of the two-dimensional image swept by the camera 53 are recognized. Therefore, on both days of the observer 7, the parallax images captured at the predetermined intervals are respectively visible, and a stereoscopic image corresponding to the binocular parallax is formed.

[0004]

However, a conventional stereoscopic display device using liquid crystal shutter glasses always has
You have to wear liquid crystal shutter glasses, which is unnatural. On the other hand, in a stereoscopic display device using a lenticular lens, the range in which a parallax image can be observed with both eyes is limited to a narrow range, and thus the observer 57 cannot freely select a position with respect to the two-dimensional display device 55. Further, in a stereoscopic display device using liquid crystal shutter glasses and a stereoscopic display device using a lenticular lens, the eye of the observer 57 is often in focus on the surface of the display device, and changes due to the displayed image. Since there is no contradiction between the displayed image recognized by the observer 7 and the focus position of the eye,
May cause eye strain. In addition, since the two-dimensional image displayed on the display device is fixed at the viewpoint position determined by the positions of the cameras 52 and 53, dynamic parallax cannot be expressed. For example, when the observer 57 moves, Since the image displayed on the display device seems to move together, there is a problem that the observer feels strange.

It is an object of the present invention to satisfy the physiological factors of stereoscopic vision such as binocular parallax, focus adjustment and dynamic parallax without using glasses or the like, and to display an electrically rewritable image. It is an object of the present invention to provide a three-dimensional display device capable of performing the following.

[0006]

A three-dimensional display device according to the present invention is a three-dimensional display device for displaying a three-dimensional object as a three-dimensional image, comprising a flat LED array for emitting light for displaying images. A first liquid crystal reflector comprising a polarizer, a reflective polarizer, a liquid crystal element provided between the polarizer and the reflective polarizer, a fixed reflector, the fixed reflector and the first liquid crystal reflector. A large number of second liquid crystal reflectors each including a liquid crystal element and a reflective polarizer provided in a laminated manner between the first liquid crystal reflector and the flat LED array;
A beam splitter that transmits light emitted from the ED array and reflects light reflected from the first liquid crystal reflector, the second liquid crystal reflector, and the fixed reflector;
The first array that emits each cut plane image obtained by sequentially cutting the three-dimensional display object from the end in the D array as a two-dimensional image, and reflects the emitted light in synchronization with each of the emitted two-dimensional images. The liquid crystal reflection plate, the plurality of second liquid crystal reflection plates, and the fixed reflection plate are sequentially switched.

(Operation) Each cut plane image obtained by sequentially cutting the three-dimensional display object from the end is emitted as a two-dimensional image from the flat LED array, transmitted through the beam splitter, and illuminates the liquid crystal reflector. At this time, the emitted light becomes polarized light by the polarizing plate provided on the first liquid crystal reflecting plate. Further, the reflection polarizing plate provided on the liquid crystal reflection plate is configured to reflect light having the same vibration plane as the reflection axis of the reflection polarization plate and transmit light having a vibration plane orthogonal to the reflection axis. . The liquid crystal reflection plate is configured to switch between a transmission state and a reflection state according to a value of a voltage applied. Therefore, a predetermined voltage is applied to a liquid crystal element provided on the liquid crystal reflector for reflecting the two-dimensional image, thereby bringing the reflector into a reflection state. Since no voltage is applied to the liquid crystal elements of the other liquid crystal reflection plates, the liquid crystal reflection plates are in a transmission state. As a result, the light reflected from the liquid crystal reflector in the reflected state enters the beam splitter again, and the observer sees a two-dimensional image that is reflected and displayed brightly. In addition, in synchronization with the two-dimensional image sequentially emitted from the flat LED array, the two-dimensional image is reflected and displayed while sequentially switching the liquid crystal reflector to be reflected. Therefore, the observer observes a two-dimensional image reflected and displayed one after another from the stacked liquid crystal reflectors. As a result, due to the afterimage phenomenon of the observer,
The cut plane images are collectively observed as a three-dimensional image (three-dimensional image).

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. FIG. 1 is a block diagram illustrating a schematic configuration of a stereoscopic display device, FIG. 2 is a schematic cross-sectional view illustrating a main part of a first liquid crystal reflector and a plurality of stacked second liquid crystal reflectors, and FIG. It is a schematic perspective view which shows the state which laminated | stacked many 1 liquid crystal reflection plates and many 2nd liquid crystal reflection plates.

The three-dimensional display device according to the present embodiment has a flat LED array 13 for emitting light for displaying an image.
And transmitting the light emitted from the planar LED array 13,
Beam splitter 12 that reflects light in the opposite direction
And a first liquid crystal reflection plate 11 which can select a reflection state or a transmission state of light transmitted through the beam splitter 12, a large number of stacked liquid crystal reflection plates 15, and a fixed reflection plate 16.

In addition, as shown in FIG.
The liquid crystal reflection plate 11 is composed of a polarizing plate 10, a liquid crystal element 19, and a reflection polarizing plate 18. The second liquid crystal reflection plate 15 includes a liquid crystal element 19 and a reflection polarizing plate 18. This first liquid crystal reflection plate 11, a large number of second
The liquid crystal reflection plate 15 and the fixed reflection plate 16 are two-dimensional images (reference numerals D1, D2,... In the figure) of the cut plane images obtained by sequentially cutting the object to be displayed as shown in FIG.
..) And the second liquid crystal reflector 1
Reference numeral 5 denotes a structure in which a large number of layers 5 are stacked between the first liquid crystal reflection plate 11 and the fixed reflection plate 16. Further, each reflected two-dimensional image is converted into the beam splitter 12.
To the observer 17 by re-entering and reflecting
Each two-dimensional image is observed.

As shown in FIG. 2A, a spacer 14 made of a transparent adhesive is provided between the first liquid crystal reflector 11, a large number of second liquid crystal reflectors 15, and the fixed reflector 16.
Are in close contact at equal intervals. This spacer 1
Reference numeral 4 denotes a refractive index (optical glass (BK-7) of glass, which is a material of the transparent substrates 1 and 2 of the liquid crystal element 19;
1.519). This is because, for example, when air enters the interface between the liquid crystal element 19 and the adjacent liquid crystal element 19, reflection occurs at about 4% at one interface, and becomes a value that cannot be ignored when the number of liquid crystal elements 19 increases. This is to prevent

The polarizing plate 10 constituting the first liquid crystal reflection plate 11 and the transparent substrate 1 constituting the liquid crystal element 19
Are bonded using an acrylic pressure-sensitive adhesive (not shown). Further, the reflective polarizing plate 18 forming the first liquid crystal reflecting plate 11 and the transparent substrate 2 forming the liquid crystal element 19 are also bonded using an acrylic adhesive (not shown).

As shown in FIG. 2 (b), the liquid crystal element 19 has a pair of transparent substrates 1 and 2 made of glass and a 90 ° twist orientation sandwiched between the pair of transparent substrates 1 and 2. The TN liquid crystal element includes a nematic liquid crystal layer 5 and sealing materials 6 a and 6 b for sealing the nematic liquid crystal layer 5. Transparent electrodes 3 and 4 that intersect each other are formed on opposing surfaces of the pair of transparent substrates.

A liquid crystal element 19 comprising the TN liquid crystal element
In the normal state (when no AC voltage is applied), linearly polarized light incident from the polarizing plate 10 is emitted by rotating the vibrating surface by 90 ° due to the light guide effect. In the selected state (when an AC voltage is applied), linearly polarized light having the same vibration plane as when the light enters is emitted. Thus, the liquid crystal element 1
Numeral 9 indicates that the polarization axis of the transmitted light can be switched between 0 ° and 90 °.

The transmission axis of the polarizing plate 10 is arranged in the same direction as the upper liquid crystal molecule alignment direction of the liquid crystal element 19 composed of a TN liquid crystal element. Place in the same direction. The reflective polarizer 18 has a property of providing a high transmittance for one polarized light and a high reflectance for another polarized light perpendicular to the polarized light. Therefore, when the liquid crystal element 19 is in a normal state (when no AC voltage is applied), the first liquid crystal reflection plate 11 and the second liquid crystal reflection plate 15 formed in a layered state are in a transmission state. On the other hand, when the liquid crystal element 19 is in the selected state (when an AC voltage is applied), the first liquid crystal reflection plate 11 and the second liquid crystal reflection plate 15 are in the reflection state. The reflection polarizing plate 1
The details of No. 8 are disclosed in JP-A-9-507308.

Next, the operation of the stereoscopic display device according to the present embodiment will be described. As shown in FIG. 1, light from a flat LED array 13 capable of displaying a light-emitting two-dimensional image passes through a beam splitter 12 and enters a first liquid crystal reflection plate 11. At this time, when the first liquid crystal reflection plate 11 and the second liquid crystal reflection plate 15 in a layered state are in a normal state (when no AC voltage is applied), the light of the flat LED array 13 is transmitted and the selected state is obtained. At the time of applying the AC voltage, the light is reflected by the liquid crystal reflection plate, enters the beam splitter 12 again, is reflected, and the light of the flat LED array 13 reaches the observer 17. As a result, the observer 17 moves the flat LED array 13
You will see each cut plane image (two-dimensional image) of the display object emitted from. When both the first liquid crystal reflection plate 11 and the second liquid crystal reflection plate 15 in a layered state are in the transmission state, the light is reflected by the fixed plate 16. Further, the two-dimensional image displayed by changing the color of the flat LED array 13 can be displayed in green or blue in addition to red. In addition, if a flat LED 13 having a plurality of colors is used, multi-color display can be performed.

Next, a method for displaying a three-dimensional image using the three-dimensional display device according to the present invention will be described. First, FIG.
Is a computer (not shown).
Alternatively, from the information of the display object stored in the external memory (not shown), each cut plane image cut in order from the edge of the display object is calculated, and the information of each of the cut plane images is calculated.
And emits a two-dimensional image of each cut plane image, and outputs the emitted two-dimensional image to a predetermined liquid crystal reflector (first liquid crystal reflector 11, second liquid crystal reflector 15) or fixed reflector. The two-dimensional image reflected and displayed by the liquid crystal reflection plate or the fixed reflection plate 16 is incident on the beam splitter 12 again, is reflected there, and reaches the observer 17. I do. At this time, a liquid crystal reflecting plate or a fixed reflecting plate that reflects in synchronization with a two-dimensional image (an image similar to D1, D2...) Of each cut plane image emitted from the flat LED array 13 is sequentially turned into a reflecting state. The two-dimensional images (displayed as D1, D2,...) Are switched and displayed. The optical path length from the light emitting flat LED 13 to the observer 17 differs depending on the selected liquid crystal reflection plate or fixed reflection plate. As a result, the observer 17 can see the three-dimensional image 23 due to the afterimage phenomenon.

In this embodiment, a single color static three-dimensional image is displayed.
Is composed of red, blue and green LEDs for color display,
By switching and illuminating each color in synchronization with the reflection display on each liquid crystal reflection plate, color display of a three-dimensional image is also possible.

In this embodiment, the liquid crystal element is T
Although an N liquid crystal element has been described as an example, similar effects can be obtained by using an STN liquid crystal element, a ferroelectric liquid crystal element, or an antiferroelectric liquid crystal element.

[0020]

As described above, the three-dimensional display device according to the present invention employs a liquid crystal reflector using a reflection type polarizing plate, thereby providing a three-dimensional display device having a small wavelength dispersion of reflection characteristics and a simple structure. Can be realized. Further, full-color display can be easily realized, and three-dimensional display of the time of a clock and three-dimensional display of a display screen of a small game machine can be realized with a simple configuration.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a schematic configuration of a stereoscopic display device according to an embodiment of the present invention.

FIG. 2 is a schematic cross-sectional view showing a main part of a plurality of laminated liquid crystal reflection plates in the embodiment of the present invention.

FIG. 3 is a schematic perspective view showing a state in which a plurality of liquid crystal reflectors according to the embodiment of the present invention are stacked.

FIG. 4 is a block diagram showing a schematic configuration of a stereoscopic display device using conventional liquid crystal shutter glasses.

FIG. 5 is a block diagram showing a schematic configuration of a stereoscopic display device using a conventional lenticular lens plate.

[Explanation of symbols]

 Reference Signs List 10 polarizing plate 11 first liquid crystal reflector 12 beam splitter 13 flat LED array 14 spacer 15 second liquid crystal reflector 16 fixed reflector 17 observer 18 reflective polarizer 19 liquid crystal element

Claims (1)

[Claims] 1. A three-dimensional display device for displaying a three-dimensional display object on a three-dimensional image, comprising: a planar LED array for emitting light for displaying an image; a polarizing plate; a reflective polarizing plate; A first liquid crystal reflector comprising a liquid crystal element provided between the reflective polarizer, a fixed reflector, and a liquid crystal device provided by being laminated between the fixed reflector and the first liquid crystal reflector; A plurality of second liquid crystal reflectors each including a reflective polarizer; and a first liquid crystal reflector provided between the first liquid crystal reflector and the flat LED array to transmit light emitted from the flat LED array. A plate splitter that reflects light reflected from the plate, the second liquid crystal reflector, and the fixed reflector, and each of the cut plane images obtained by sequentially cutting the three-dimensional display object from the end with the flat LED array. Fire as a two-dimensional image, each of the two fired A three-dimensional display device configured to sequentially switch between the first liquid crystal reflector, the plurality of second liquid crystal reflectors, and the fixed reflectors that reflect the emitted light in synchronization with a three-dimensional image. .