JPS5858870B2 - Gazouhiyoujisouchi - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an image display device, and particularly to an image display device that can display images on a large screen in real time.

As an image display device that displays a large screen in real time that has been proposed so far, the number of modulated and deflected scans W ~ 10
Laser television projects a few watts of laser light directly onto a screen and looks at the reflected light from the screen.Schlieren optical systems irradiate an oil film with a modulated, deflected and scanned electron beam and observe the deformation of the oil film that occurs in response to the signal. There is an ``Idophor,'' which projects images onto a screen, and a large CRT television.

However, each of these has drawbacks and cannot be easily used.

In other words, in laser televisions, the laser output is several watts to 10
Several watts are required, and in order to obtain this much visible light laser output, an input of 30 to 70 kW is required, and furthermore,
Since the laser light is coherent light, the light reflected from the screen is not completely diffused light, resulting in disadvantages such as flickering of the image and making it difficult to see.

In addition, with IDOFOL, which projects the deformation of an oil film using a schlieren optical system to obtain a large image, it is necessary to maintain the oil film, cathode, polarizing plate, etc. in a high vacuum in a vacuum device, and oil films in particular generate various organic gases. However, it has the disadvantage that the oil film itself decomposes and the emitted gas destroys the cathode, greatly reducing the electron emission ability and shortening the lifespan.

In addition, since it is technically impossible to make large cathode ray tubes themselves, the screen size of large cathode ray tube televisions is naturally limited to 1 d or less, and it is difficult to obtain larger images. It is.

An object of the present invention is to provide a new large-sized image display device that eliminates the drawbacks of various conventional image display devices.

According to this invention, there is provided a photosensitive plate made of a substance that generates an excited state when irradiated with light, and a laser light source for irradiating the photosensitive plate with light that is modulated and deflected in response to an external signal to create an excited state in the substance. , a visible light source for uniformly irradiating the photosensitive plate without creating an excited state, and a schlieren for enlarging the image.

An image display device including an optical system is obtained.

Next, the principle of this invention will be explained.

The central point of this invention is to generate an excited state of a photochemical by irradiating it with light, such as ultraviolet light, having sufficient energy to generate an excited state of the photochemical.

When photochemical substances in an excited state stop being irradiated with ultraviolet light, they lose their energy and return to their original ground state.

Generally, when a photochemical substance is in an excited state, its refractive index is different from the refractive index when it is in the ground state.

That is, a photosensitive plate filled with a photochemical substance such as a cell is irradiated with ultraviolet light to cause a local change in the refractive index, and another visible light is uniformly irradiated on the photosensitive plate in this area. Local refractive index changes are imaged using a schlieren optical system and projected to obtain a large screen image.

First, the excited state of a substance due to light will be explained.

Various photochemical substances have a ground state with the lowest energy and many erect states with higher energy, as shown in Figure 1.

At room temperature, photochemicals are normally in a stable ground state;
It shows the polarization specific to that state, or in other words, the refractive index.

When a photochemical substance in this ground state is irradiated with light having sufficient energy to generate an excited state, the photochemical substance absorbs the light and becomes excited.

The refractive index of the material in this erect state is different from the refractive index in the ground state.

Now, as shown in Figure 1, the ground state of the photochemical substance is A,
If the wJ state is A, then when light with energy hν□ is irradiated, the substance absorbs the light and becomes A.

That is, the following equation holds. Next A+hν →A・・・・・・・・・・・・・ (1) ■ The change in (1) due to light irradiation is usually very fast, 10”
It is about sec.

If you continue to irradiate the light, rice will The proportion of A states increases.

On the other hand, the A7 state returns to the A state by phosphorescence, fluorescence, or a non-radiative process.

That is, the following formula holds true. rice A → (2) This speed varies depending on the photochemical.

If you choose a substance with an appropriate relaxation time, then A
The rice state will have a reasonable lifespan.

When selecting a photochemical substance that absorbs energy in the photochemical process and then loses it to reversibly return to its original state, it is important to select a photochemical substance that has high absorbance at the wavelength of the irradiated light and has an appropriate extinction time for the excited state. It is necessary to select a substance that has a long length and is large enough to dissociate from an excited state through a photochemical change or cause a chemical reaction.

Such photochemicals can be found in many organic or inorganic materials.

For example, if these photochemical substances have good uniformity, they can be used as a photosensitive plate, or they can be dissolved in a solvent and then solidified with a binder on glass, or they can be placed in a cell and made into a solution. can be used as a photosensitive plate.

Next, the present invention will be explained with reference to the drawings. FIG. 2 is a diagram schematically showing the configuration of an embodiment of the present invention.

1 is a photosensitive plate made of a photochemical substance that generates an excited state when irradiated with ultraviolet light or the like.

UV laser (e.g. He-Cd+laser', 325
The ultraviolet laser light emitted by person 0) 2 is modulated by modulator 3,
After being deflected horizontally by the first deflector 4 and vertically by the second deflector 5, it passes through a lens 6, is reflected by a reflecting mirror 7, and is focused onto the photosensitive plate 1.

The substance inside the photosensitive plate 1 absorbs the modulated ultraviolet laser light,
The substance becomes erect at the position 8 that is hit by the laser beam, and the parts that are not hit by the laser beam remain in their original state.

In this way, the substance within the photosensitive plate 1 spatially successively enters an excited state and returns to the ground state by the modulated and deflected ultraviolet laser light, thereby producing a spatial refractive index difference.

9 is a light source such as a Xe arc lamp, and a lens 10
is a condenser lens.

A lattice-shaped light shielding plate 11 is placed in front of the lens 10, and only the light that passes through it advances.

The lens 12 is a lens for forming an image of the lattice-shaped light-shielding plate 11 onto the second lattice-shaped light-shielding plate 13 .

Photosensitive plate 1] When the ultraviolet laser beam is not irradiated, the light from the light source 9 is blocked by the light shielding plate 13, so that the screen 15 is dark.

When the photosensitive plate 1 is irradiated with ultraviolet light to create an excited state and the refractive index of that part changes, the light from the light source 9 is refracted at that part and passes through the second lattice-shaped light-shielding plate 13.

This light beam forms and projects the refractive index difference produced on the photosensitive plate 1, ie, the image, onto the screen by the lens 14.

That is, the local difference in refractive index on the photosensitive plate 1 is projected onto the screen 15 as a bright and dark image.

The ultraviolet laser 2 used in the present invention may be a small one with an output of about a few TrLW, and the light source 9 may be a Xe arc lamp or the like, which is economical as it requires less electrical input.

Further, the photosensitive plate does not need to be in a vacuum, and can be easily manufactured by filling cells with a photochemical substance or by fixing it to glass or the like.

Furthermore, the photochemical substance used may be solid, liquid, or gas.

The image has excellent features such as being able to be enlarged arbitrarily using an optical system.

The above embodiment is just an example, and it goes without saying that various changes may be made to the schlieren optical system, the method of irradiation with ultraviolet laser light, etc.

[Brief explanation of drawings]

Figure 1 is a diagram to explain light absorption by photochemical substances.
FIG. 2 is a schematic diagram of an embodiment of the present invention. (In this figure, 1 is a photosensitive plate, 2 is an ultraviolet laser, 3 is an optical modulator, 4 is a horizontal deflector, 5 is a vertical deflector, 6 is a lens that focuses light on the photosensitive plate, 7 is a reflecting mirror that reflects ultraviolet laser light and transmits visible light; 9 is a visible light source; 1
Reference numeral 1.13 is a grid-like light shielding plate, 10 is a condenser lens, and 12 and 14 are lenses forming a Schlieren optical system.

Claims (1)

[Claims] 1. A photosensitive plate made of a photochemical substance that causes a change in refractive index when irradiated with light, a laser light source with a wavelength that is absorbed by the chemical substance, means for modulating the laser light emitted by the laser light source according to signal intensity, and the photosensitive plate. a deflection unit that scans and irradiates a modulated laser beam onto the photosensitive plate; a visible light source that uniformly irradiates the photosensitive plate; and a Schlieren optical system that forms and projects the visible light that has passed through the photosensitive plate; An image display device that forms an image using a change in refractive index that occurs when the photochemical substance absorbs the laser light and changes from a ground state to an excited state.