JPS63300281A - Charge storage plate using photoconductive 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 charge storage device using a conductive plate used in a projection display device or the like.

(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 bulb.

Such light valves are used in projection display devices.

An electro-optic crystal plate (for example, treated as a LiNbO3 single crystal) is placed at a position corresponding to the fluorescent surface in the vacuum container of the cathode ray tube,
The changes caused in the electro-optic crystal plate by the electron source are
2. Description of the Related Art Projection display devices are known that read and project light using a polarizing plate placed outside.

(Problems to be Solved by the Invention) It is better for the electro-optic crystal plate used in the above-mentioned projection display device to be thin in order to improve the spatial resolution.

When applied to a projection type ice spray device, it is preferable that accumulated charges can be erased in a short time because real-time operation is performed using a video signal.

Currently, in order to erase the written information (accumulated charge), secondary electron emission from the storage surface (L i N b O3 crystal surface) is caused by the electron flow from the electron gun, resulting in M product. A method is used to neutralize the electric charge.

In order to shorten this erasing time, it is necessary to increase the electron flow for causing secondary electron emission.

In order to shorten this erasing time, it is necessary to increase the number of electrons emitted from the electron gun within a unit time, which poses a problem in terms of the performance of the electron gun.

Furthermore, if an attempt is made to reduce the thickness of the crystal in order to improve the spatial resolution, the electrical capacity of the storage surface will increase, and the erase charge will also increase.

The main objective of the present invention is to provide a charge storage plate using a conductive plate whose crystal thickness can be reduced to improve spatial resolution.

Still another object of the present invention is to provide a conductive plate having an erasing function that allows the crystal to be thinned and erased in a short time.

(Means for Solving the Problems) In order to achieve the above object, a charge storage plate using a conductive plate according to the present invention has a large number of through electrodes arranged in the insulating plate in the thickness direction of the insulating plate. a conductive plate whose entire surface is irradiated with electrons emitted from an electron source and accumulates a charge for each N current-carrying rod; and a conductive plate arranged on one surface of the conductive plate and facing each electrode of the conductive plate, and a conductive plate whose entire surface is irradiated with electrons emitted from an electron source and which accumulates charge for each N current-carrying rod; It consists of a dielectric plate that undergoes an optical change corresponding to the amount of electrons accumulated in the dielectric plate, and a transparent electrode disposed on the other surface of the dielectric plate.

Further, in order to achieve still another object of the present invention, there is provided a charge storage plate using a conductive plate according to the present invention, in which a large number of through electrodes are arranged in the thickness direction of the insulating plate, and one side is away from the electron source. A conductive plate that is irradiated with the emitted electrons and accumulates charge in each through electrode, and a portion of the conductive plate that is arranged on one side of the conductive plate and faces each electrode, the amount of electrons accumulated in each electrode. a dielectric plate that undergoes an optical change corresponding to;
a transparent electrode disposed on the other surface of the dielectric plate; an erasing surface disposed on one surface of the insulating plate where the resistance between the plurality of conductive electrodes is rapidly reduced by light irradiation; and a charge on the erasing surface. It consists of a discharging means for discharging.

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

FIG. 1 is a sectional view showing an embodiment of a charge storage plate using a conductive plate according to the present invention.

FIG. 2 is a diagram showing an embodiment of a projection display device using a charge storage plate using this conductive plate.

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

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

As shown in FIG. 1, this conductive plate 10A has a large number of through electrodes arranged on an insulator 11, and forms a 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 5.

It can be considered that each through electrode 12 of the conductive plate 10A, a portion of the dielectric material corresponding to the amount of the snowy road electrode, and a portion of the transparent electrode each form a capacitor.

The electric charge held by the through electrode 12 changes the electric field in the portion of the dielectric between the end surface of the through electrode 12 and the transparent electrode 6 corresponding to the amount of the through electrode.

This electric field changes the optical properties (for example, 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, and a thin tungsten wire 50 is suspended from the center so that the thin tungsten wire 50 is coaxially attached to the molten glass 52. Pull it out through the nozzle.

The glass fibers, each of which has a thin tungsten wire as a core material, are bundled in a geometrically regular manner, and are then pressed together using a covering glass to form a single rod-like 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).

Note that in the above embodiment, an example was shown in which the tungsten thin wire 50 was 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 is made by bundling a large number of glass fibers 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 play 1 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 method examples is polished flat and smooth on both sides 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
It becomes possible to use dielectrics, adhesives, and liquid materials that emit large amounts of gas, which were previously unusable.

Furthermore, even if the material is thermally unstable, external cooling means such as water cooling can also be used.

In addition, as seen in LiNbO3 crystals, etc., when exposed to strong readout light or when there is a sudden temperature change, the optical fishing rod may be damaged or cracks may occur.

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 the present invention can be used in a light valve that can perform writing on a dielectric material by changing the amount of charge of an electron beam, and read out and display detailed information written by an external reference light such as a laser beam, and the insulating effect This means that the range of material selection for written substances 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.

Such a structure is convenient for storing charge in each through electrode. It is not always convenient to erase the charge for rewriting. FIG. 4 shows the second part of the conductive plate which is the main component of the projection display device.
FIG. 2 is a cross-sectional view showing an embodiment of the present invention (with a light guide engraving and erasing function).

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 serving as a connecting means, and the electric charges are erased.

During the next writing, the cadmium sulfide photoconductor 13 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 degree erasing function) which is a main component of the projection display device, and FIG. 5A is a plan view and FIG. A cross-sectional view is shown.

An N-type layer 1 is formed on the vacuum container side surface of the insulating substrate 11 of the conductive plate.
4.18 and a P-type layer 16 are provided.

The conductive layer 15 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 layer 16 - N type layer 14 -
This becomes a 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 much more quickly than a method that uses a charge neutralization method using secondary electron emission, such as the erasure method using No. 3. 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 explained in detail above, the charge storage plate using the conductive plate according to the present invention is unique! A large number of through electrodes are arranged in the thickness direction of the insulating plate in the slope, and one surface is irradiated with electrons emitted from the electron source, and a conductive plate that accumulates charge for each current-carrying rod is used to prevent the spread of charge. are doing.

An optical change corresponding to the amount of electrons accumulated in each electrode can be generated in a portion of a dielectric plate disposed on one surface of the conductive plate facing each electrode of the conductive plate.

Furthermore, the charge storage plate using the conductive plate according to the present invention is provided with an erasing surface which is arranged on one surface of the insulating plate and where the resistance between the plurality of conductive electrodes is rapidly reduced by light irradiation. The discharging means for discharging charges is provided to have an erasing function of rapidly erasing accumulated charges by irradiation with light.

Therefore, by using the charge storage plate using the conductive plate according to the present invention in a projection display device, the resolution of the written charge image can be improved, and by providing it with an erasing function that quickly erases it by irradiation with light, it can be used. It is possible to improve the degree of

[Brief explanation of drawings]

FIG. 1 is a sectional view showing an embodiment of a charge storage unit using a conductive plate according to the present invention. FIG. 2 is a diagram showing an example of a projection display device using a titanium storage plate using this 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 junction type erasing function) which is a main component of the T-type display device, in which FIG. 5A is a plan view and FIG. 1 is a cross-sectional view. 1... Electron gun 2... Deflection coil 3... Focusing coil 4... Airtight container 5 of projection display device... Dielectric material 6... Transparent electrode 7...・Transparent protection plate 8... Half mirror 10 (IOA, IOB, 10C)... Conductive plate 11...
・Conductive, sloped insulating substrate 12... Conductive plate common electrode 13... Photoconductor 14 for short circuit... N-type layer 15... Conductive layer (ohmic contact with 14) 16...
P-type layer 17...photodiode 18 for shorting...N-type layer 50...tungsten thin wire 51...funnel-shaped container 52...molten glass 53...glass melting heater

Claims (4)

[Claims] (1) A conductive plate in which a large number of through electrodes are arranged in the thickness direction of the insulating plate, one surface of which is irradiated with electrons emitted from an electron source, and which accumulates charge in each through electrode; a dielectric plate disposed on one surface of the plate and facing each electrode of the conductive plate, which undergoes an optical change corresponding to the amount of electrons accumulated in each electrode; A charge storage plate using a conductive plate made of transparent electrodes. (2) a conductive plate in which a large number of through electrodes are arranged in the thickness direction of the insulating plate, one surface of which is irradiated with electrons emitted from an electron source, and which accumulates charge in each through electrode; a dielectric plate disposed on one surface of the plate and facing each electrode of the conductive plate, which undergoes an optical change corresponding to the amount of electrons accumulated in each electrode; an erasing function consisting of a transparent electrode, an erasing surface disposed on one surface of the insulating plate and on which the resistance between the many through electrodes is rapidly reduced by light irradiation, and a discharging means for discharging the charges on the erasing surface. A charge storage plate using a conductive plate. (3) The conductive plate according to claim 2, wherein the erasing surface is a photoconductive material or a photodiode. (4) A charge storage plate using a conductive plate according to claim 2, wherein the discharge means is a connection means that becomes a low resistance body in connection with a sudden decrease in resistance of the erasing surface.