JPH08172648A - Three-dimensional display device - Google Patents

Abstract

PURPOSE: To display a 3-dimensional video image without limiting a position of eyes of a viewer and processing huge information quantity even in the case of displaying a moving image while preventing a feeling of incongruity or fatigue of the viewer. CONSTITUTION: A beam radiation device 6 emits an image forming beam L onto a screen 3 formed by laminating plural unit screens 2 whose state is changed into a light transparent state or a light diffusion state. The unit screens 2 diffusing the image forming beam are sequentially selected.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a display device capable of displaying a three-dimensional image.

[0002]

2. Description of the Related Art Most conventional display devices using a CRT (cathode ray tube) or a liquid crystal panel display a two-dimensional image.

As a display device for displaying a three-dimensional image, by giving different two-dimensional images including parallax information to the left eye and the right eye of an observer, it is illusion that they are three-dimensional images. There is something. For example, it is formed by a left-eye polarizing plate corresponding to one image display light and a right-eye polarizing plate corresponding to the other image display light by superimposing and displaying images of two types of polarizations whose polarization directions are orthogonal to each other. Some observers wear eyeglasses. In addition, the observer wears spectacles equipped with a left-eye shutter and a right-eye shutter that alternately display different images including parallax information in time, and alternately open and close in synchronization with a change in the display. There is something to do. A two-dimensional display that emits image display light so that the right eye of an observer is in focus, and a two-dimensional display that emits image display light so that the left eye is in focus, such as a so-called head-mounted display device. There is one equipped on a helmet or the like. Further, two kinds of images are superimposed and displayed on a screen equipped with a lenticular lens or a slit plate, and each image display light progresses so that one image is visually recognized by the right eye and the other image is visually recognized by the left eye. Those that regulate the direction have also been proposed.

As a display device for displaying a three-dimensional image, there is a display device for recognizing a three-dimensional image by forming a light wave equivalent to the presence of an actual three-dimensional object by a holographic technique.

[0005]

The problem that the observer needs to wear a special device such as glasses or a helmet in order to make an illusion that a two-dimensional image is a three-dimensional image has a problem in that they are troublesome to wear. is there. In addition, 3D
The one that regulates the traveling directions of the two types of image display light in order to give the illusion that it is a three-dimensional image has a problem that the position of the observer's eyes is limited. Furthermore, using such an illusion causes discomfort and fatigue.

In the case of recognizing a three-dimensional image by the holographic technique, it is necessary to record interference fringes on the photosensitive material by the light from the actual object and the reference light, so that only a still image can be formed. Although it is possible to display a moving image by forming a hologram by obtaining the interference fringe shape by a computer, the interval of the interference fringes is so small that it corresponds to the wavelength of visible light, and therefore a huge amount of information is processed. It is difficult to put it into practical use at present.

It is an object of the present invention to provide a three-dimensional display device which can solve the above problems.

[0008]

A three-dimensional display device of the present invention includes a screen formed by stacking a plurality of unit screens capable of changing a state of transmitting light and a state of diffusing light, and each unit. A three-dimensional image is provided by providing a means for switching the screen between a light transmitting state and a diffusing state and a light beam irradiation device for irradiating the screen with the image forming light beam, and sequentially switching the unit screens for diffusing the image forming light beam. It is characterized by being able to display. As the light beam irradiation device, for example, a laser device is used as a light source, and a light beam having a strong directivity emitted from the laser device is deflected by a deflecting device to irradiate an image forming light beam for forming an optical image on a screen. Or an image projection device such as a liquid crystal projector is used to irradiate the screen with the image display light projected from the image projection device as an image forming light beam, and diffuse the focus of the image display light into the image forming light beam. It is possible to use a unit screen which is changed according to the switching of the unit screens to form an optical image on each unit screen.

[0009]

According to the three-dimensional display device of the present invention, the image forming light beam applied to the screen is diffused in the unit screen which is in the light diffusing state. An image formed on a unit screen can be constructed. When the unit screens for diffusing the image forming light beam are sequentially switched, the unit screens are moved in a direction orthogonal to the image display surface, so that a three-dimensional image can be formed in the screen by the afterimage effect. That is, a three-dimensional image can be formed by utilizing the afterimage effect, and different image information can be given to the left and right eyes of the observer. Therefore, a dedicated device for making an illusion that the two-dimensional image is a three-dimensional image is provided. There is no need for the observer to wear it, it is possible to prevent the observer from feeling uncomfortable and tired as in the past, and the position of the observer's eyes is not limited,
It is not necessary to process an enormous amount of information even when displaying a moving image, and it can be easily put into practical use by the current electronic technology and widely spread.

[0010]

Embodiments of the present invention will be described below with reference to the drawings.

The three-dimensional display device 1 shown in FIG.
A screen 3 configured by stacking a plurality of unit screens 2 is provided. As shown in FIG. 2, each unit screen 2 has a liquid crystal layer 2a and a pair of transparent electrodes 2b and 2c sandwiching the liquid crystal layer 2a, and changes in the arrangement direction of liquid crystal molecules constituting the liquid crystal layer 2a. Thus, the state can be changed between a state of transmitting light and a state of diffusing light. Each unit screen 2 is connected via a switch 5 to a power source 4 for applying a voltage to both transparent electrodes 2b and 2c.
In the normal state when no voltage is applied between 2c, the liquid crystal layer 2a is in a glass-like shape and diffuses light.
When a voltage is applied between b and 2c, the liquid crystal layer 2a switches to a transparent and light-transmitting state. That is, by switching the switch 5, it is possible to set any unit screen 2 to the light diffusion state and set the other unit screens 2 to the light transmission state at any time.

An irradiation device 6 for irradiating the screen 3 with an image forming light beam is provided. The irradiation device 6 is
A laser device 7 for emitting a light beam and a deflecting device 8 for the light beam are provided. The deflecting device 8 includes two mirrors 8a, 8b and driving devices 8c, 8 for the respective mirrors 8a, 8b.
d and. The light beam emitted from the laser device 7 is reflected by each of the mirrors 8a and 8b, and then irradiates the screen 3 from the back side as an image forming light beam. At the irradiation position, the mirrors 8a and 8b are driven by the driving device 8
An arbitrary position can be set by displacing by c and 8d. The light beam applied to the screen 3 is
The light is diffused on the unit screen 2 in the diffused state, and a person observing from the outside of the screen 3 appears to shine the point at the diffusion position.

The switches 5, the laser device 7, and the driving devices 8c and 8d are connected to the control device 9. The control device 9 controls ON / OFF of each switch 5 according to the three-dimensional image displayed on the screen 3, controls the laser device 7 to emit a light beam, and controls each drive device 8c, 8d to control each. The mirrors 8a and 8b are driven.

According to the above three-dimensional display device 1,
The image forming light beam L shown by the imaginary line in FIG. 1 applied to the screen 3 from the irradiation device 6 is diffused in the unit screen 2 in the light diffusing state, and thus the unit screen 2 in the light diffusing state. The image formed on the can be constructed. Unit screen 2 for diffusing the image forming light beam
When the switch 9 is turned on and off by the control device 9 to sequentially switch, the unit screen 2 is moved in a direction orthogonal to the image display surface, so that a three-dimensional image is displayed on the screen 3 due to the afterimage effect. Can be formed. Further, the irradiation position of the image forming light beam can be changed to an arbitrary position by controlling the driving devices 8c and 8d by the control device 9 to drive the mirrors 8a and 8b. Desired 3 as shown by the phantom line in
The three-dimensional image 10 can be displayed. Further, in the above embodiment, each unit screen 2 is normally in a state where the switch 5 is turned off to diffuse the light, so that the light beam does not directly enter the eyes of the observer, which is preferable for safety.

The present invention is not limited to the above embodiment. For example, the intensity of a light beam can be adjusted to adjust the density of an image, and further, three kinds of image forming light beams corresponding to the three primary colors of light can be irradiated on the screen.
An irradiation device having three laser devices having mutually different oscillation wavelengths may be used, which makes it possible to display a full-color three-dimensional image. As the laser device, a semiconductor laser is preferable in that the light intensity can be easily adjusted, and when a laser with a fixed output that does not require the light intensity adjustment is used, not only the semiconductor laser but any type of laser light source can be used. it can. Even when a fixed output laser is used, the light intensity can be adjusted by disposing a variable transmittance element in the optical path. As the variable transmittance element, for example, an element in which a plurality of filters having different transmittances are attached to a rotating plate or the like and which can be selectively arranged in the optical path can be used. When light sources corresponding to the three primary colors of light are used for displaying a color image, the light from each light source may be diffused by different unit screens.

Further, in the light beam deflecting device 8,
Not limited to the mirrors 8a and 8b, all optical deflection elements such as holographic optical elements and acousto-optical elements can be used.

The light beam emitted from the laser device may be a polarized laser or a non-polarized laser, and a polarizing plate may be arranged in the optical path to the screen 3 to form a polarized laser. Polarizing plates oriented orthogonally may be arranged on the surface of the screen 3. As a result, even when all the unit screens 2 are in a light transmitting state due to a failure or the like, the light beam does not directly enter the eyes of the observer, which is preferable for safety.

The irradiation device of the above embodiment uses a laser device as a light source, and an optical image is formed on a screen by deflecting a light beam having a strong directivity emitted from the laser device by a deflecting device. However, the light source is not limited to the laser device, and light from an arbitrary light source may be condensed by an optical system so as to form an optical image on each unit screen. Further, an image projection device such as a liquid crystal projector is used as the irradiation device, the image display light projected from the image projection device is irradiated onto the screen as an image forming light beam, and the focus of the image display light is diffused by the image forming light beam. It is also possible to form an optical image on each unit screen by changing it according to the switching of the unit screens.

[0019]

BEST MODE FOR CARRYING OUT THE INVENTION In the three-dimensional display device of the present invention, the light irradiating device corresponds to three primary colors of light.
It is preferable to have a light source capable of irradiating various types of image forming light beams, and to adjust the intensity of each of the irradiated image forming light beams. As a result, a full-color three-dimensional image can be displayed.

Further, in the three-dimensional display device of the present invention, the image forming light beam is polarized and irradiated from the back side of the screen, and the surface side of the screen is polarized in a direction orthogonal to the polarization direction of the image forming light beam. Preferably the plates are arranged. This can prevent the image forming light beam from directly entering the eyes of the observer.

[Brief description of drawings]

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

FIG. 2 is a configuration diagram of a unit screen according to an embodiment of the present invention.

FIG. 3 is a diagram showing an image display example of a display device according to an embodiment of the present invention.

[Explanation of symbols]

 2 unit screen 3 screen 5 switch 6 irradiation device L image forming light beam

Claims (1)

[Claims] 1. A screen configured by stacking a plurality of unit screens capable of changing a state of transmitting light and a state of diffusing light, and a unit for switching each unit screen between a light transmitting state and a light transmitting state. And a light beam irradiation device that irradiates the screen with a light beam for image formation, and a three-dimensional image can be displayed by sequentially switching unit screens that diffuse the light beam for image formation.
Dimensional display device.