JPS5932860B2 - Target for two constant potential storage tubes - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a target for a two-potential storage tube, and more particularly to a storage target having a plurality of insulated storage dielectric islands on the inner surface of an insulating support plate.

U.S. Pat. No. 3,293,474 has a face plate, the inner surface of which is coated with a mesh-like collector electrode, and within the mesh (openings) are independent island-like fluorescent storage dielectrics. A storage target for a cathode ray tube is disclosed.

This dielectric can height is in contact with the mesh electrode, and this structure creates a halo around the dielectric height, providing background light.

This results in the disadvantage that the contrast is insufficient, especially under dark lighting.

Even if the material of this dielectric height is not in contact with the mesh electrode, the aforementioned halo still occurs around each dielectric height because the dielectric height is not completely insulated from the mesh electrode.

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide an improved Turkerato structure for a two-potential storage tube that allows charge images to be stored with excellent contrast.

Another object of the present invention is to provide an improved two-potential storage tube target that has low target capacitance and high maximum write speed and is capable of storing charge images.

Yet another object of the present invention is to use a phosphor as a storage dielectric to store the charge image formed thereon and form a visible light image corresponding to this charge image, with excellent brightness, high contrast, An object of the present invention is to provide an improved direct view storage target with high resolution and virtually no background light.

An additional object of the present invention is to provide an improved storage tube in which the construction of the storage target is simple, robust, and reliable, so that large storage tubes can be manufactured without reducing the resolution of the image stored in the target. It is to provide.

Still another object of the present invention is to provide a mesh electrode in the form of a conductive film on an insulating support plate, and to extend the mesh electrode over a part of the mesh so that the insulating non-storage phosphor directly contacts the support member. An object of the present invention is to provide an improved storage tube in which a storage phosphor containing multiple spaced storage regions is disposed within an insulated opening in the mesh, thereby reducing the size of the opening.

Another object of the present invention is to provide mesh electrodes and islands of storage phosphor within mesh openings on an insulating coating on a conductive layer to enable selective erasure of storage information displayed on storage targets. An object of the present invention is to provide an improved target for a two-potential storage tube.

Other objects and advantages of the present invention will become apparent from the detailed description of the preferred embodiments illustrated in the accompanying drawings.

The gist of the invention is to provide a charge image storage device, particularly a charge image storage device for storing a charge image on a target for a controllable desired period of time and producing a visible light image;
Alternatively, the present invention relates to a storage target for a cathode ray tube from which an electrical signal corresponding to such a charge image is obtained.

This storage target includes a mesh electrode coated on one side of an insulator support plate, and an insulator layer (an insulating non-storage fluorophore).
covers the periphery of the mesh electrode opening and a portion of the opening to make the opening smaller, but exposes a portion between the openings of the mesh electrode to serve as the collector electrode region, and separates the dielectric (storage phosphor) into each Multiple islands of dielectric material are placed within an insulated mesh and isolated from the mesh electrodes to provide approximately zero background light and color write-through or color contrast of displayed information.

Since it is a direct view type, this dielectric region is made of phosphor and is isolated from each other, the charge image formed there is accumulated as a bistable charge image for a desired time, and a light image corresponding to the charge image is emitted. do.

In this case, the support plate is made of a transparent material. This specification also discloses the photographic fabrication of a storage target with mesh electrodes as described above to obtain a fine mesh pattern to increase the resolution of the charge image.

In order to selectively erase the stored information, a storage target may be formed on the inner surface of the support plate with a thin transparent conductive layer and a thin transparent insulating coating interposed therebetween.

A conductive mesh electrode is deposited on this transparent insulating film, and the inside of this mesh opening and the periphery of the opening is covered with an insulating film (insulating non-storage phosphor), and this insulating film is also in contact with the transparent insulating film. Therefore, this reduces the size of the mesh openings and leaves an exposed portion of the mesh electrode between the mesh openings, which serves as a collector electrode (secondary electron collecting electrode).

To selectively erase some of the information accumulated on this storage target, the irradiation electron gun is shut off, the conductive layer is pulsed from a positive low voltage to a high voltage, and the selected areas from which the accumulated information is to be erased are exposed to electrons. Shock with a beam.

The conductive layer is then returned to the initial low voltage and the irradiation electron gun is activated to maintain the stored information that will not be erased.

Storage targets made in accordance with the present invention are particularly useful when used in direct view bipotential storage tubes forming part of cathode ray tube oscilloscopes in which transient electrical input signal waveforms are stored for further study.

However, such storage tubes can also be used as conventional storage tubes such as radar, sonar or computers.

The storage target of the present invention has an increased maximum writing speed compared to conventional storage targets due to a higher secondary electron emission ratio of the insulator covering a portion of the conductive mesh surrounding the dielectric phosphor height. It has many advantages.

When the target is scanned with the writing beam, the insulator is immediately brought to a resting potential equal to the voltage applied to the conductive mesh.

Since the insulator surrounds and is in close proximity to the dielectric phosphor height, the phosphor is at the same resting potential due to capacitive coupling.

Another reason is that the capacitance of the storage target is low and the writing speed of the target is high, so that a charge image of high frequency information can be stored.

The use of a mesh electrode, rather than a continuous electrode, under the storage dielectric of the storage target is responsible for this capacitance reduction.

Furthermore, the direct view storage target according to the present invention produces an optical image with low background light and good contrast.

Although the photographic method for producing storage targets described herein is simple and inexpensive, it is disclosed in U.S. Pat.
Resolution comparable to conventional storage tubes using wire mesh electrodes for storage targets as disclosed in the Harris patent is obtained.

The storage target structure of the present invention is simple, robust, and reliable because the mesh electrode, insulator, and storage dielectric are all provided on a common support plate of insulator.

Therefore, due to the planar structure of the storage target of the present invention,
The difference from conventional targets using wire mesh is that a large storage tube can be easily realized without the problem of increasing the thickness of the mesh electrode element.

Another advantage of the present invention is that each storage dielectric region of the target is approximately uniform so that when the readout beam scans the target, the electrical readout signal has less noise and shading due to electric field bending.

The high resolution stored information results in an excellent hard copy of the stored information.

The insulator that covers the mesh electrode to insulate the dielectric material from the mesh electrode is made of a phosphor with non-storage characteristics, and this insulator is used to display non-storage information, and the storage information is displayed by islands of fluorescent dielectric material. Thus, a so-called write-through operation mode can be achieved.

The color of the emission from the insulating phosphor is different from that of the fluorescent dielectric islands, allowing accumulated and non-accumulated information to be observed simultaneously with excellent contrast.

This insulator also has a storage property, and by making the emitted light color different from the dielectric layer, the written and accumulated information is a composite color of the double-band luminescent material, and the background is the color of the insulator and the non-information. Good contrast for observation.

In addition to the effects described above, the storage target of the present invention provides a substantially uniform electric field distribution across the back surface of the target, whether or not a charge image is stored thereon.

This is because the conductive elements forming the mesh electrodes are exposed between the storage dielectric regions of this target.

Since all elements of the mesh electrode are at the same potential, potential changes in the dielectric region have very little effect on the total potential distribution on the back surface of the target.

The potential distribution then becomes substantially uniform.

Conventional targets having electrodes beneath a continuous layer of storage dielectric material produce a non-uniform electric field distribution on the back surface of the target due to the different charges stored in adjacent regions of the dielectric layer.

This non-uniform potential distribution affects the transmission of the slow irradiation beam to the storage target to retain the charge image formed on the storage target by the writing beam, and acts similar to an "area grid". This causes distortion in the charge image.

The present invention will be explained in more detail below based on preferred embodiments.

FIG. 1 shows a direct-view two-potential storage tube 10 having a storage target according to the present invention.

The storage tube includes a single electron gun including a cathode 14, a control grid 16, a focusing anode structure 18, and a pair of horizontal deflection plates 20.
It may also have a vertical deflection plate 22.

This single electron gun can be adapted to produce either a write or read beam 23, the selection of which is determined by three interlocked switches 24, 26 and 28 controlling the grid 16, the horizontal deflection plate 20 and the vertical deflection plate 22, respectively. Connect to W using the method described below.
This is done by switching between RITE and READ positions.

However, it will be appreciated that two independent electron guns can be used to generate the write and read beams, respectively.

The writing beam is deflected onto the storage target by an input signal applied to the vertical deflection plate to direct it to the storage target 12.
Shape the charge image on top.

to be accomplished.

The readout electron beam scans the charge image stored on the storage target 12, for example in the shape of a conventional television rask, thereby obtaining an electrical readout signal.

One or more irradiation electron guns 30 are provided in the bulb of the storage tube 10, and the surface of the storage target 12 is approximately uniformly bombarded with a low-velocity irradiation electron beam, and a write electron beam is formed on the storage target. The charge image is maintained or retained even after the writing electron beam ceases to impact it.

The storage target according to the present invention is shown in FIG. 6. First, to facilitate understanding of this storage target, the second
The accumulation targets shown in FIGS. 5 to 5 will be explained.

2 and 3, a mesh electrode 32 connected to a DC target power supply via a load resistor 34, an insulating layer 37 covering the mesh electrode and part of the opening except for an exposed area 39 of the mesh electrode, and It includes a storage dielectric 36 in an array of spaced apart islands or dots of rectangular, circular or other desired shape disposed within an insulated opening, the islands of storage dielectric being isolated from the mesh electrode 32.

The exposed region 39 of the mesh electrode 32 forms a collector electrode region.

When the target voltage applied to the mesh electrode 32 is within one stable target voltage range, that is, when the islands of the dielectric material 36 of the storage target can accumulate a charge image for a desired time, the writing beam of high-speed electrons is activated by secondary electron radiation. A charge image is formed on the dielectric material 36.

This charge image has a more positive potential than other regions due to the attraction of low-velocity irradiation electrons collected by the exposed region 39 of the mesh electrode 32.

The potential of the "written" charge image is above the critical voltage corresponding to the first crossover voltage on the secondary electron emission characteristic curve of the dielectric, and the "unwritten" background area of the dielectric is below this critical voltage.

The irradiation electrons impacting the storage target bring the potential of the dielectric 36 in the "written" areas to a high voltage steady state corresponding to the potential of the mesh electrode, and the potential of the "unwritten" background areas to the irradiation gun. Drive to a low voltage steady state corresponding to the voltage applied to the cathode of 30.

This biconstant accumulation operation has already been described in U.S. Pat. No. 3,293,473.
It is explained in the issue.

Load resistor 34 is connected to +5 via variable bias resistor 38.
The variable bias resistor 38 is connected to a DC power source of 0.00 volts to adjust the target voltage applied to the mesh electrode 32.

To erase the charge image accumulated on the target 12, the resistance of the variable resistor 38 is decreased so that the voltage applied to the mesh electrode exceeds the "fade positive" voltage of the dielectric 36 so that the irradiating electron beam is makes the potential of the dielectric layer uniformly written to a positive potential.

Next, the resistance value of the variable resistor 38 is increased to reach a "retention threshold" at which the storage target can no longer accumulate charge images.
Do not lower the voltage.

The voltage applied to the mesh electrode is then increased above the "retention threshold" voltage of the dielectric 36 below which the storage target cannot store a charge image.

The voltage applied to the mesh electrode is then increased above the threshold voltage so that the target voltage is within a "stable range" so that the dielectric layer can accumulate charge images and the target can receive other charge images.

During the write operation of the storage tube of FIG.
A slightly negative voltage of -3,025 volts is applied relative to 0 volts.

The horizontal deflection plate 20 is connected to the horizontal sweep generator 4 by a switch 26.
0, and the vertical deflection plate 22 is connected via a switch 28 to a vertical amplifier 42, which may be a conventional one used in common oscilloscopes.

An input signal having a waveform desired to be stored in the storage target 12 is applied to the input terminal 44 of the vertical amplifier 42 .

The dielectric 36 of the storage target 12 may be of the Pl type, rare earth activated rare earth oxides or oxysulfides, as well as conventional phosphors such as pH, P2O.

The phosphor may be a photoconductive phosphor such as P22 or P31, the dielectric producing a light image corresponding to the charge image accumulated on the storage target if the storage tube is of the direct view type.

In this case, an electrical readout circuit is not required since the input signal waveform can be observed directly from the faceplate of the storage tube, but the technology disclosed in U.S. Pat. In some cases it may be preferable.

The storage dielectric is in the form of a plurality of separate islands, or dots, and is insulated from the target electrode by an insulator 37, which prevents the image of charge accumulated on the dielectric from bleeding into the storage dielectric. Conductive phosphors may also be used.

The insulator 37 may be a non-fluorescent insulator such as aluminum oxide, thorium oxide, or silica, but it may also be a rare earth-activated fabric oxide or oxide whose surface is treated with an oxide of a color different from that of the dielectric 36. Non-storage fluorescers such as sulfides may also be used.
It is also possible to display non-accumulated information of a different color from the accumulated information so that image information can be easily compared.

This operation is called write-through.

The insulator 37 may also be a storage fluorophore, such as a rare earth activated rare earth oxide or oxysulfide, with a different emission color than the dielectric 36, so that the information stored on the dielectric 36 is transferred to the dielectric 36.
The insulator 37 may be displayed in a composite color of the insulator 37, and the insulator 37 may produce a background color of the insulator 37 on both sides of the stored information to create a color contrast between the stored information and the background.

The insulator 37 may be, for example, a europium-activated yttrium oxide or oxysulfide with a red luminescent color.

The storage dielectric may be, for example, a Pl or terbium-activated yttrium oxide or oxysulfide with a green emission color.

Furthermore, P31°P22. Conductive phosphor such as pH dielectric material 3
6 to store information.

A collimating electrode 45, which is a conductive coating layer, may be provided on the inner surface of the funnel-shaped portion of the tube near the storage target 12.

A DC voltage of +50 volts is applied to this collimating electrode to focus the irradiated electrons onto the storage target, and the positive potential Turkerato region attracts a portion of the irradiated electrons from the nearby negative potential region.Accumulated information is generated by the above-mentioned planar grid effect. Eliminate distortion.

However, if the dielectric layer 36 is not a fluorescent material but a secondary electron emissive material such as aluminum oxide or magnesium oxide, the storage tube is provided with a readout circuit to read the charge image accumulated on the storage target. It must be possible to obtain an electrical readout signal that

To do this, switch 24 applies a voltage of -3,050 volts DC to control grid 16 to reduce the density of the electron beam flowing from cathode 14 to the target and prevent the readout beam from accumulating a charge image on the target. do.

Furthermore, the horizontal deflection plate 20 and the vertical deflection plate 22 are each connected to a switch 2.
6.28 to the scanning signal generator 46.

This scanning signal generator applies sawtooth waves of different frequencies to both deflection plates to deflect the read beam into a television scanning line.

The scan line may cover all or part of the storage target 12 to magnify a portion of the image stored there.

This image enlargement is achieved by adjusting the scanning signal generator and using the vertical deflection plate 2.
This can be done automatically by ensuring that the vertical scan signal applied to 2 is within two voltage limits corresponding to the ends of the waveform that is desired to be expanded.

The electrical readout signal presented at the mesh electrode 32 is applied via a coupling capacitor 48, a low impedance preamplifier 50, and a high gain amplifier 52 to the Z-axis input of a remotely located television monitor tube 54 or other recording device. be done.

The horizontal and vertical deflection plates of the monitor tube 54 are connected to the scanning signal generator 4.
6 to display the entire waveform image accumulated on the accumulation target 12 of the accumulation tube or a portion thereof on the monitor tube 54.

Even when the storage dielectric layer 36 of the target 12 is a phosphor, it is preferable to use a monitor tube and electrical readout circuitry so that a magnified image of the stored information or a portion thereof can be remotely observed or displayed. You can obtain a hard copy of the stored image.

These techniques are described in U.S. Patent No. 3,679,824.
Disclosed in the issue.

As shown in FIGS. 2 and 3, the storage tube target 12
uses a mesh electrode 32 which is a coated layer of a conductive material provided on one surface of a transparent support plate 56 of an insulating material, which may be a glass face plate portion of a CRT tube.

The bulb may include a ceramic funnel 58 sealed to the faceplate 56 by a glass frit 60.

The mesh electrode 32 may be formed of an opaque conductor such as aluminum, nichrome, or silver, or a transparent conductor such as tin oxide.

A part of the mesh electrode 32 is drawn out of the bulb via the sealing part 60 and forms a conductive wire part 61 with the mesh electrode inside the bulb.

The storage target dielectric 36 comprises a plurality of spaced storage regions of phosphor or other dielectric material, each storage region being applied through an insulator 37 within an opening of the mesh electrode 32 on the inner surface of the faceplate 56. Ru.

Each storage region is separated from one another by an insulating element of the mesh electrode, with the collector electrode region 39 exposed from the insulator 37.

The storage dielectric region is in direct contact with the faceplate 56 in lateral relationship with the insulated mesh electrode element to provide a barrier between the continuous conductive layer on the faceplate and the writing beam as part of a conventional target. It is not something that has been set up.

As a result, the capacitance formed by such a dielectric region and which has to be charged by the writing beam impinging on the storage target is radically reduced.

The dielectric region may be rectangular, the circular formation may be any other desired shape;
All have approximately the same thickness and a low capacitance that is approximately uniform over the entire surface of the storage target.

Further, the outer edges of the back surfaces of these regions are rounded without being rounded, and the uniform capacitance can be obtained because of the large electric field generated at the acute corners.

The storage target of the present invention can easily be made into a large flat or curved surface.

Depending on the material used, the insulator 37 determines its mode of operation.

If it is a non-fluorescent material, the background light is almost zero.

If a non-storage phosphor is used as insulator 37, color write-through can be achieved.

If insulator 37 is a storage phosphor, excellent contrast can be obtained.

The storage target shown in FIGS. 2 and 3 is a preferred construction when using a non-fluorescent material as the insulator 37 to increase the fluorescent area and obtain high write brightness and low background light.

The targets of FIGS. 2 and 3 can also be used for color write-through operation.

The dielectric layer 36 occupies about 70% of the total target area, the insulator 37 accounts for about 20%, and the collector electrode 39 accounts for about 10%.
occupies

Although the storage target structure of FIGS. 4 and 5 is preferred when using a color contrast mode of operation, this structure can also be used in a color write-through mode of operation.

The target in FIGS. 4 and 5 is the mesh electrode 32a.
is made of a transparent conductor such as tin oxide, and a large number of dots 41 of an opaque conductor such as an alloy of nickel and chromium are fixed to the conductive region of the mesh electrode 32a to form an exposed collector electrode region 41 as shown in FIG. It is the same as FIGS. 2 and 3 except for the following points.

Insulator 37a extends into the mesh of mesh electrode 32a against the surface of faceplate 56a to reduce the mesh and insulate the islands of phosphor storage dielectric 36a.

Insulator 37a completely covers the conductive portion of mesh electrode 32a except for exposed collector electrode region 39.

This insulator 37a is a storage or non-storage fluorescent dielectric of a color different from that of the dielectric of island 36a for color contrast or color write-through modes of operation.

The dielectric island 36a is about 50% of the total target area, the insulator 37a is about 40%, and the collector electrode 41 is about 10% of the total target area.
Husbands account for %.

The transparent conductor 32a also occupies 40% of the total target area, and its transparency is reduced to about 14 by the pattern of opaque collector electrode points 41 affixed to its surface.

A scale that allows a plurality of scratch lines is provided on the inner surface of the face plate 56 at the bottom of the storage target 12, and the dielectric layer 3
When 6 is a phosphor, it is used as an internal scale to perform test measurements of the light image formed on the storage target.

The inner scale may be illuminated by entering light from the end surface of the face plate 56.

Furthermore, the scale may be a glass frit printed linearly on the inner surface of the face plate.

A scale may be provided on the face plate 56a.

The storage target structure shown in FIGS. 2 and 3 is manufactured by the following steps.

■ Apply an opaque conductive material such as chrome, nickel, or an alloy of nickel and chromium to one side of the faceplate.

(2) A layer of photosensitive material (photoresist) is provided on this conductor layer.

■ Light is applied to this photoresist through a mask patterned into a conductive mesh.

(2) Develop the exposed image and etch the conductor underneath.

(A typical corrosive agent is a solution of cerium ammonium sulfate and nitric acid.

) ■ Remove the photoresist in unexposed areas (generally by cleaning with acetone or similar solution).

By the above steps (1) to (2), an opaque conductive mesh is formed on the glass face plate.

■ A second layer of photoresist is applied over the conductive mesh and glass faceplate.

■ Place another mask near the photoresist and expose the photoresist from a light source to create a "dot" pattern of polymerized photoresist that forms the collector region.

■A conductive mesh is used as a cathode in an electrolyte (generally isopropyl alcohol and aluminum nitrate).

This electrolyte contains small positively charged particles of insulators (generally aluminum oxide, thorium dioxide, or silicon dioxide).
float.

When a voltage is applied to the mesh, these insulating particles travel toward and adhere to the entire surface of the conductive mesh that is not protected by the previously provided photoresist spots forming the collector region.

This insulator has a thickness of 1 μm or more and covers the exposed ends of the mesh openings.

■Fix the phosphor using a conventionally well-known photographic fixing technique.

One method is to deposit a single layer of a slurry of 100 g phosphor, 100 g polyvinyl alcohol, 10100 O water, LO ml isopropanol, and 20 g ammonium dichromate.

Since this slurry is photosensitive, it polymerizes upon exposure to light.

The phosphor pattern is created by exposure through a conductive mesh that acts as a photomask.

[Phase] The phosphor in the unexposed area is developed by washing with water.

Bake the 0 faceplate to remove the organic binder from the phosphor and remove the photoresist from the collector area.

Next, a method of manufacturing the color contrast storage target shown in FIGS. 4 and 5 will be described.

■A transparent conductive material such as tin oxide is provided on one side of the glass face plate.

(2) Coating an opaque conductor such as nickel and chromium alloy on this transparent conductive film.

■A photoresist layer is provided on this nickel-chromium film.

(2) Expose the photoresist through a mask having a mesh-shaped pattern.

■ Developing the exposed image of the photoresist and etching the underlying opaque conductor and transparent conductive layer (typical etchants are cerium ammonium sulfide in nitric acid, followed by hydrochloric acid and zinc powder).

■Remove the unexposed areas of the photoresist (using acetone or similar solvent).

(2) Next, the photoresist layer is exposed to light through a mask provided in its vicinity and developed to form a dot pattern of photoresist that acts as a collector region.

■ The storage phosphors of this target are formed into an island pattern of phosphors surrounded by an opaque conductive mesh using standard photographic fixing techniques.

(2) Areas of the opaque conductor not protected by the photoresist are removed by etching in a solution that etches only this material and does not etch the transparent conductor.

(A typical etchant is cerium ammonium sulfide in nitric acid.

This step results in a pattern of opaque conductive dots protected by photoresist and fixed onto a transparent conductive mesh.

) [Phase] A transparent conductive mesh is used as a cathode in an electrolyte (usually of isopropyl alcohol and ammonium nitrate) in which fine, positively charged particles of a dielectric phosphor are suspended.

A typical fluorophore is europium-activated yttrium oxysulfide.

(If the target is to be a color write-through target, the phosphor is pretreated so that it does not emit light at a normal storage voltage, but instead emits light at a higher voltage.

) When a voltage is applied to the mesh, the phosphor particles move toward the mesh electrode and attach to all areas of the transparent conductive mesh not protected by photoresist.

Of course, the phosphor particles will not adhere to the previously provided phosphor islands since they are electrically insulated from the mesh.

The faceplate is then baked to remove the organic binder and photoresist from the phosphor and collector regions.

FIG. 6 shows an embodiment of a target for a two-potential storage tube according to the present invention.

The face plate 56b, which is a transparent insulating support plate, has a thin transparent conductor layer 62 deposited on its inner surface by vapor deposition or the like.
has.

This layer 62 may be tin oxide or indium tin oxide with a thickness of about 0.2 microns.

A transparent insulating film 64 is coated on this transparent conductive layer 62 by about 1 inch.
Form to a thickness of μ.

The transparent insulating coating 64 is silicon oxide, silicon dioxide, or aluminum oxide, and is preferably vacuum deposited on the conductive layer 62.

The conductor layer 62 and the insulator layer 64 have a laminated structure.

A mesh electrode 32b, an insulating non-storage phosphor 37b and an island of storage phosphor 36b are provided on the insulator layer 64 as described in connection with the storage targets of FIGS. 2, 3 and 4 and 5. The storage target structure is completed using the same method as above.

The mesh electrode 32b is connected to the load resistor 34 via a lead wire portion 61b, and the conductor layer 62 is connected to a pulse generating circuit 66 which allows a conventional design via a lead wire portion 68.

The pulse generating circuit 66 supplies a rectangular erasing pulse 70 to the target electrode 62 when erasing the accumulated information being displayed.

Selective erasure of information stored in the storage target of FIG. 6 is accomplished using techniques disclosed in US Pat. No. 4,139,800.

That is, first, the irradiation electron gun 30 is shut off, and the target electrode (
The transparent conductor layer 62 is pulsed at +400 cm, which is coupled to the surface of the phosphor layer 36b by capacitive coupling, and is added to the potential of the collector electrode (mesh electrode) 32b.

The write electron beam 23 is then directed at a selected area of the storage target to be erased for a predetermined period of time, such that the phosphor layer in this area is changed to the potential of the collector electrode 32b by secondary electron emission.

When the potential of the target electrode 62 is returned to O2, the surface potential of the phosphor layer is brought to a potential below the voltage level at which accumulation occurs due to capacitive coupling.

Then, the irradiation electron gun is turned on, the written information is returned to its storage state, and the potential of the unwritten area and the erased area is set to a high voltage below the voltage level at which storage occurs.

To completely erase the storage targets, an erase pulse is applied to the collector electrode 32b to put all the targets into a written state, and the writing electron beam 23 returns them to a state ready for writing stored information.

If desired, an erase pulse can be applied to the target electrode 62 at the same time as the erase pulse is applied to the collector electrode 32b to speed up the erase operation.

In all of the methods for manufacturing the storage target described above, the photosensitive layer is exposed to light in the form of a lamellar pattern, and the mesh electrode 32.
a, 32b.

This provides the mesh electrode with a plurality of substantially uniform small apertures and a large number of small mesh elements, resulting in a large number of small phosphor regions 36.36a and 36b within the isolated apertures of the mesh electrode. It will be done.

This fine storage target enables charge image storage and visible light image formation with extremely high resolution, which could never be achieved with conventional storage targets formed from multiple wire meshes.

As described above, according to the present invention, the insulating non-storage phosphor is provided at the periphery of the opening of the mesh electrode to insulate the storage phosphor from the mesh electrode. Even if an electric field is generated around the electrode and the irradiated electrons collide with the non-storage phosphor, the non-storage phosphor has low luminous efficiency against slow electrons, so a halo around the periphery of the storage phosphor as in the past Does not occur.

In addition, when displaying a non-storage image, the storage and non-storage phosphors emit light together with the writing beam, improving the brightness.Furthermore, if a non-storage phosphor with a different emission color from the storage phosphor is used, the non-storage image can be displayed. can be displayed in the composite color of both wall light bodies, and color light-through can be performed.

Furthermore, since a transparent conductor layer is provided which is insulated from the storage phosphor etc. by a transparent insulating coating, the erasing operation can be performed quickly by supplying an erasing pulse to the transparent conductor layer and the mesh electrode. can.

It should be noted that although the above description has been made only regarding the preferred embodiments of the present invention, it will be obvious to those skilled in the art that various changes and modifications can be made without departing from the gist of the present invention.

Therefore, it goes without saying that the technical scope of the present invention includes these modifications.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an embodiment of a storage tube having a two-potential storage tube target according to the present invention and related circuits, and FIGS. 2 to 5 are diagrams for explaining the structure of the storage target according to the present invention. FIG. 2 is a partially enlarged view of the two-potential storage tube target along line 2-2 in FIG. 1, and FIG. 3 is an enlarged rear view of the storage target along line 3-3 in FIG. ,
4 and 5 are views corresponding to FIGS. 2 and 3 of storage tube targets according to other examples, and FIG. 6 is a partially enlarged view of a preferred embodiment of a two-potential storage tube target according to the present invention. FIG. In the figure, 32b is a mesh electrode, 36b is a storage phosphor, 3
7b is an insulating non-storage phosphor, 56b is a transparent insulating support plate, 62 is a transparent conductor layer, and 64 is a transparent insulating film.

Claims (1)

[Claims] 1. A transparent insulating support plate, a transparent conductor layer provided on one surface of the support plate, a transparent insulating film provided on the conductor layer, and a plurality of openings provided on the insulating film. a transparent conductive mesh electrode having a transparent conductive mesh electrode, an insulating non-storage phosphor provided at the periphery of the opening of the mesh electrode, and an insulating non-storage phosphor provided within the opening of the mesh electrode. A target for a two-potential storage tube, comprising a storage phosphor insulated from the mesh electrode.