JPS63168679A - Projection type display device using electrode plate - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a projection display device using an electrode plate having through electrodes.

(Prior Art) A device that obtains a projected image by partially reflecting or transmitting a bundle of light rays emitted with a constant intensity from a light source depending on an input signal is called a light valve.

Such light pulp is used in projection display devices.

An electro-optic crystal plate (for example, a LiN b O3 single crystal plate) is placed at a position corresponding to the fluorescent surface inside the vacuum chamber of the cathode ray tube, and the changes caused in the electro-optic crystal plate by the electron source are placed outside. A projection type display device is known that uses a polarized plate to perform reading and projection using light.

(Problems to be Solved by the Invention) In the projection display device described above, the writing section using an electron beam must be provided in a vacuum.

Therefore, the dielectric to be written (in the above example LiNbO3
crystal) will be placed in a vacuum.

Many dielectric materials, adhesives, etc. themselves generate gas.

Further, among the dielectric materials, adhesives, etc., many of them are difficult to vent out gas in advance.

This severely limits the selection of materials that can be used in vacuum.

Even if oil or the like, which releases relatively little gas, is installed as a dielectric in a vacuum, the desired degree of vacuum cannot be maintained unless the vacuum is constantly evacuated during operation.

An object of the present invention is to provide a projection display device using an electrode plate that does not reduce the degree of vacuum inside a vacuum container used in the projection display device.

(Means for solving the problem) In order to achieve the above object, an electron source, a dielectric material that undergoes an optical change corresponding to the density distribution of electrons emitted from the electron source, and an optical In a projection display device that uses an electrode plate that reads out changes in color using light,
An electrode plate having a large number of through electrodes arranged in the thickness direction of the insulating plate is placed in a container so that one side is irradiated with electrons emitted from the electron source and the other side faces the dielectric. It is arranged and configured to maintain airtightness.

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

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

An airtight container 4 for light pulp of a projection display device is provided with an electron gun 1 for writing.

Electrons from the electron gun 1 are scanned over one surface of the conductive plate 10 by a deflection coil 2 and a focusing coil 3.

FIG. 2 is a sectional view showing a first embodiment of a conductive plate which is a main component of the projection display device.

This conductive plate 10A has a large number of through electrodes arranged on an insulator 11, and forms part of the vacuum wall of the container.

A dielectric material 5 such as an electro-optic crystal is disposed in close contact with one surface of the conductive plate 10A. A transparent electrode 6 is provided on the other surface of the dielectric 5.

Note that a transparent protection plate 7 is provided on the surface of the transparent electrode 6.

Each through electrode 12 of the conductive plate 10A and the through type 8 of the dielectric
The portion corresponding to i12 and the transparent electrode portion can be considered to form a special capacitor.

Due to the charge held by the through electrode 12, the through electrode 12
The electric field in the portion of the dielectric between the end face of the transparent electrode 6 and the through electrode 6 corresponding to the through electrode 12 changes. This electric field changes the optical properties (eg, refractive index) of the dielectric.

Dielectric material 5 given by the charge held by through electrode 12
The distribution of changes in the optical characteristics within is read out by the readout light incident through the half mirror 8 and projected onto a screen (not shown).

Next, a method for manufacturing the conductive plate 10A will be explained with reference to FIG.

First, a thin tungsten wire 50 with a diameter of several tens of micrometers is coated around the tungsten wire 50 with a glass having good adhesion (for example, Pyrex glass) to produce a glass-covered tungsten wire 54 (a glass fiber having a tungsten wire as a core).

As shown in FIG. 3, a glass melting heater 53 is arranged around a funnel-shaped container 51 to produce molten glass 52, a thin tungsten wire 50 is suspended from the center, and the tungsten wire 50 is coaxially inserted with the molten glass 52 into a nozzle. Pull it out through.

These glass fibers with tungsten wire as a core material are bundled geometrically and regularly, and are then pressed together using a covering glass to form a single rod shape without leaving any spaces.

A conductive plate as shown in FIG. 2 is obtained by cutting the fixed rod-shaped tungsten thin wire bundle at right angles to the longitudinal direction of the fiber (slicing it into plate shapes).

Incidentally, in the embodiment described above, an example is shown in which the tungsten wire 50 is used as the material of the through electrode 12.

Kovar wire is used instead of the tungsten thin wire 50.

The same thing can be done using other thin conductor wires such as molybdenum wires.

The conductive plate 10A can also be manufactured by a manufacturing method completely different from the method described above.

A microchannel plate is known as a device that multiplies electrons.

This microchannel plate has a large number of glass fibers tied together to form a large number of channel portions, and these channels are provided with a secondary electron multiplication function.

Hot molten indium (In) is forced to flow into the channel portion of the channel plate under pressure.

Alternatively, it may be immersed in a melt of indium (In) and gradually pulled up.

As a result, the channel portion is filled with solidified indium (In), and a through electrode is formed.

The wafer-shaped conductive plate obtained by the above two methods is polished on both sides to be flat and at a constant temperature, and is incorporated into a light valve to form a part of the vacuum partition of the light valve.

As a result, the dielectric 5 is not directly exposed to vacuum, so that it becomes possible to use dielectrics made of thick materials that emit gas, adhesives, and liquid materials that could not be used in the past. - Also, even if the material is thermally weak, external cooling means such as water cooling can also be used.

In addition, as is also seen in L i N b 03 crystals, when exposed to strong read light or when there is a sudden temperature change, optical damage or cranking occurs.

If the present invention is adopted in such a case, the crystal can be easily replaced with a new normal crystal because it is isolated from the vacuum part.

As mentioned above, the switching operation by the electron gun,
The conductive plate of this invention can be used in a light valve that can write on a dielectric material by changing the amount of charge of an electron beam, and then read and display the written detailed information from an external reference source such as a laser beam. This means that the range of material selection can be greatly expanded.

In the light valve as described above, each through electrode 12 of the conductive plate 10A is independent, so there is no electrical continuity between the electrodes.

Although such a structure is convenient for storing charge in each through electrode, it is not necessarily convenient for erasing the charge for rewriting.

FIG. 4 is a sectional view showing a second embodiment (with a light guide engraving and erasing function) of a conductive plate which is a main component of the projection display device.

The structure is the same as that described above in that a large number of through electrodes 12 are provided on the insulating substrate 11 of the conductive plate 10B.

It can be manufactured using the same manufacturing process as in the embodiment described above.

A short-circuiting photoconductor 13 is formed on the inner surface of the vacuum container 4 using a sintered body of cadmium sulfide (CdS).

The photoconductor 13 for shorting and the transparent electrode 6 are then connected by a photodiode 17.

When the shorting photoconductor 13 and the photodiode 17 are simultaneously irradiated with erasing light, the surfaces of the through electrodes 12 inside the vacuum container 4 are connected with a low resistance value.

The photoconductor 13 for shorting and the transparent electrode 6 are brought to approximately the same potential by the operation of the photodiode 17, and the charges are erased.

During the next writing, the cadmium sulfide is kept in the dark, the resistance is increased, writing is performed, and an erasing light irradiation cycle is selected. By repeating the above operations, moving images or video screens can be displayed continuously.

FIG. 5 is a diagram showing a third embodiment of a conductive plate (with a bonding type erasing function) which is a main component of the projection display device, in which FIG. 5A is a plan view and FIG. A cross-sectional view is shown.

On the vacuum vessel side surface of the insulating substrate 11 of the conductive plate, an N-type layer:
J14.18 and a P-type layer 16 are provided.

The conductive rgJ15 is in ohmic contact with the N-type layer 14, and connects the through electrode 12 of the conductive plate and the N-type layer 14.

As a result, between adjacent through electrodes 12, an NPN structure (
Through electrode 12-N type layer 14-P type 1'1t16-N type layer 14-through electrode 12).

A dielectric material 5. is provided on the other surface of the insulating substrate 11 of the conductive plate. transparent electrode 6
is placed.

When the junction of the NPN structure is irradiated, each electrode is connected with extremely low resistance.

The erasing time of this method is short, and compared to conventional methods such as LiNbO
The process is completed far more quickly than in the case of the erasure method in which the electron beam 3 is used, which uses a charge neutralization method by emitting secondary electrons. This is due to the short circuit discharge method.

Note that the photoconductor or junction provided for erasing may be covered with a suitable material so as not to be hit by the electron beam, or a method may be used in which the electron beam is scanned intermittently.

(Effects of the Invention) As described in detail above, the projection display device according to the present invention includes: an electron source; a dielectric material that undergoes an optical change corresponding to the density distribution of electrons emitted from the electron source;
In a projection display device using an electrode plate that reads optical changes in the dielectric with light, one side of the electrode plate has a plurality of through electrodes arranged in the thickness direction of the insulating plate, and one side of the electrode plate is connected to the electron source. The container is irradiated with electrons emitted from the container, and the container is arranged so as to keep the container airtight so that the other surface faces the dielectric material.

As a result of the above, even though the writing method uses an electron beam, it can be used without any restrictions even if the material to be written is unsuitable for installation in a vacuum, and an unprecedented projection display device such as moving images and images using video signals can be obtained. It will be done.

Note that with the current technology, electrode openings can be made up to about 50 μm.

Appropriate values for these intervals are selected depending on the withstand voltage, resolution, and effective area depending on the dielectric material used, but it is desirable to have a large area.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing an embodiment of a projection display device according to the present invention. FIG. 2 is a sectional view showing a first embodiment of a conductive plate which is a main component of the projection display device. FIG. 3 is a schematic diagram for explaining a method of manufacturing a glass-coated tungsten wire, which is the basic material of the conductive plate. FIG. 4 is a sectional view showing a second embodiment of a conductive plate (with an erasing function) which is a main component of the projection display device. FIG. 5 is a diagram showing a third embodiment of a conductive plate (with a bonding type erasing function) which is a main component of the projection display device, in which FIG. 5A is a plan view and FIG. FIG. 1... Electron gun 2... Deflection coil 3... Focusing coil 4... Airtight container of projection display device 5... Dielectric material 6... Transparent electrode 7... Transparent protection plate 8. ... Half mirror 10 (IOA, IOB, l0C) ... Conductive plate 11 ...
- Insulating substrate 12 of the conductive plate...Through electrode 13 of the conductive plate...Photoconductor 14 for shorting...N type layer 15...Conductive layer (ohmic contact with 14) 16...
P-type layer 17... short-circuiting photodiode 18... N-type layer 50... tungsten thin wire 51... funnel-shaped container 52... molten glass 53... glass melting heater

Claims (1)

[Claims] In a projection display device using an electron source, a dielectric material that undergoes an optical change corresponding to the density distribution of electrons emitted from the electron source, and an electrode plate that reads out the optical change of the dielectric material with light, An electrode plate having a large number of through electrodes arranged in the thickness direction of the insulating plate is placed in a container so that one side is irradiated with electrons emitted from the electron source and the other side faces the dielectric. A projection display device using electrode plates, characterized in that the electrode plates are arranged and configured to maintain airtightness.