JP2002110027A - Spacer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a picture image forming device using a surface conductive type electronic discharge element. SOLUTION: A plate type spacer to specify an interval between a rear plate on which the electronic emission element is arranged and a face plate on which a picture image forming member is arranged has a support member on its end part so as to be independent.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electron-emitting device, and more particularly to a spacer for use in an image forming apparatus such as an image display device or a recording device using a surface conduction electron-emitting device.

[0002]

2. Description of the Related Art Conventionally, two types of electron emitting devices, a thermionic electron source and a cold cathode electron source, are known. The cold cathode electron source includes a field emission type (hereinafter abbreviated as FE type), a metal / insulating layer / metal type (hereinafter abbreviated as MIM type), a surface conduction electron-emitting device (hereinafter abbreviated as SCE type), and the like. is there.

[0003] As an example of the FE type, W. P. Dyke
& W. W. Dolan, "Field emissi
on ", Advance in Electron P
physics, 8, 89 (1956) and C.I. A. Spi
ndt, “Physicalproperties o
f thin-film field emissio
n cathodes with mollybdenu
m cones ", J. Appl. Phys., 47,
5248 (1976) and the like are known.

As an example of the MIM type, C.I. A. M
ead, "The tunnel-emission
amplifier ", J. Appl. Phys., 3
2,646 (1961) and the like are known.

Further, as an example of the SCE type, M. I. E
Linson, RadioEng. Electron
Phys. , 10, 1290 (1965).

The SCE type electron-emitting device utilizes a phenomenon in which an electron is emitted by passing a current through a small-area thin film formed on a substrate in parallel with the film surface.

As the surface conduction type electron-emitting device, one using an SnO ₂ thin film by Erinson et al., Au
By a thin film [G. Dittmer: "Thin S
Solid Films ", 9, 317 (1972)],
In ₂ O ₃ / SnO ₂ by thin film [M. Hartwe
ll and C.I. G. FIG. Fonstad: “IEEEET
rans. ED Conf. ", 519, (197
5)], using a carbon thin film [Hisashi Araki et al .: Vacuum,
26, No. 1, p. 22 (1983)].

As a typical device configuration of these surface conduction electron-emitting devices, the above-mentioned M.S. FIG. 14 shows a device configuration of the Hartwell. In the figure, reference numeral 11 denotes an insulating substrate.
Reference numeral 13 denotes a thin film for forming an electron-emitting portion, which is formed of an H-shaped metal oxide thin film or the like formed by sputtering. The electron-emitting portion 12 is formed by an energization process called forming, which will be described later.

Conventionally, in these surface conduction electron-emitting devices, the electron-emitting portion forming thin film 1 is formed before electron emission.
In general, the electron-emitting portion 12 was previously formed by applying an electric current called forming in advance. That is, forming refers to an electron emission in which a voltage is applied to both ends of the thin film 13 for forming an electron emission portion, the thin film for forming an electron emission portion is locally broken, deformed or deteriorated, and is in a state of high electrical resistance. That is, the part 12 is formed. Incidentally, in the electron emitting portion 12, a crack may be generated in a part of the thin film 13 for forming the electron emitting portion, and the electron emission may be performed near the crack.
Hereinafter, the electron-emitting-portion-forming thin film 13 including the electron-emitting portion formed by the forming is referred to as a thin film including the electron-emitting portion.

In the surface-conduction type electron-emitting device subjected to the forming treatment, a voltage is applied to the thin film 13 including the above-mentioned electron-emitting portion, and a current is caused to flow through the surface of the device to cause the electron-emitting portion 12 to emit electrons. is there.

FIG. 15 is a cross-sectional view showing an apparatus for evaluating the radiation characteristics of electrons emitted from the above-mentioned electron-emitting portion, wherein 11 is an insulating substrate, 14 and 15 are device electrodes, and 13 is a thin film including an electron-emitting portion. , 12 indicate an electron emitting portion, 16 indicates a glass substrate, 17 indicates an anode electrode made of a transparent conductive film, 18 indicates a fluorescent film that emits visible light by irradiating electrons, 19 indicates a power supply for applying a voltage to the electron emitting element, Reference numeral 20 denotes a high-voltage power supply for applying a voltage to the anode 17. A power supply 19 is connected to the device electrodes 14 and 15, and an anode 17 connected to a power supply 20 is disposed above the electron-emitting device. The glass substrate 16 having the anode electrode 17 and the fluorescent film 18 and the electron-emitting device are installed in a vacuum device.

In the above evaluation device, the device electrodes 14,
When a voltage of several hundred volts to several thousand volts is applied to the anode electrode 17 by applying a voltage between the electron emitting portions 12 and 15, the emitted electrons are emitted from the electron emitting portion 12 to the surface of the insulating substrate 11. With respect to the normal (dashed line in the figure)
The positive electrode side of the voltage applied to the element (the element electrode 1 in FIG. 15)
5) (the trajectory indicated by the dotted line with an arrow in the figure), and the center of the light emitting portion on the fluorescent film 18 is shifted from the normal line.

The above-mentioned radiation characteristics are considered to be due to the potential distribution in a plane parallel to the insulating substrate 11 being asymmetric with respect to the electron-emitting portion. (However, the FE or MIM type shows this characteristic depending on the configuration).

A multi-element and panel structure in which a plurality of such surface conduction electron-emitting elements are arranged is described in, for example, US Pat. No. 5,066,883 by the present applicant.

The electron-emitting device as described above has a 10 ^-6 T
Since the device is operated in a vacuum of about orr or more, when forming an image forming apparatus using the electron-emitting device, an atmospheric pressure resistant structure is required. In particular, in the case of a flat-type image forming apparatus that supports atmospheric pressure resistance using a large-area rear plate (corresponding to the insulating substrate 11 in FIG. 15) and a face plate (corresponding to the glass substrate 16 in FIG. 15), Becomes extremely thick, and the feasibility is poor in terms of weight, cost, and the like. In order to avoid this, the image forming apparatus can be reduced in weight by arranging a spacer for atmospheric pressure resistance as a support between the rear plate and the face plate to have an atmospheric pressure resistant structure.

[0016]

Since the above-mentioned atmospheric pressure-resistant spacer is configured to withstand a pressure perpendicular to each plate surface, it usually has a shape including a surface element connecting the respective plates. Therefore, when the image forming apparatus is configured using the surface conduction electron-emitting device having the above-described electron emission characteristics, there are the following problems.

(1) The emitted electron beam is deflected to the element electrode side of the positive electrode, collides with the anti-atmospheric pressure spacer arranged on the element electrode side of the positive electrode, and the amount of electrons reaching the phosphor film is reduced. And the luminous efficiency decreases.

(2) Charge-up of the anti-atmospheric pressure spacer caused by electron beam collision causes a change in the electron trajectory due to a change in the potential distribution, and also causes a destruction of the element due to a creeping discharge due to a decrease in the creeping breakdown voltage. .

(3) If the electron-emitting devices are sparsely arranged in the plate to avoid the above problems, a high-definition image forming apparatus cannot be realized.

Due to the above-mentioned problems, the surface conduction electron-emitting device has the advantages of a simple device structure and an easy arrangement of a plurality of devices. It had not been actively applied.

The present invention has been made in view of the above problems, and an object of the present invention is to provide an image forming apparatus using an electron-emitting device without obstructing a trajectory of electrons emitted from the electron-emitting device. Another object of the present invention is to provide a panel structure capable of obtaining a high-brightness, high-definition image, and in particular, to provide a shape of an atmospheric pressure resistant spacer suitable for this purpose.

[0022]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention is directed to a plate-like plate for defining a distance between a rear plate on which an electron-emitting device is provided and a face plate on which an image forming member is provided. It is a spacer, so that it can be independent
The spacer has a support member at an end.

According to the present invention, it is preferable that "the length in the longitudinal direction is longer than the image forming range, and the supporting members are arranged at both ends in the longitudinal direction", and "the image forming range is disposed on the rear plate. This is the range where the electron-emitting devices are located. ''
And that both sides are sandwiched between the pair of support members.

According to the spacer of the present invention, since the support member is provided at the end so that the plate-like spacer can stand on its own, the plate-like spacer can be prevented from falling down. In addition, since the length in the longitudinal direction is longer than the image forming range and the support members are disposed at both ends in the longitudinal direction, the electron-emitting device is not crushed.

[0025]

The present invention will be described in detail below with reference to examples.

<Reference Example 1> FIGS. 1 and 2 are diagrams showing a schematic configuration of an image forming apparatus according to this reference example. FIG. 1 is a sectional view taken along a plane perpendicular to each plate surface. FIG. It is AA sectional drawing.

In these figures, 1 is a face plate, 2 is a rear plate, 3 is a surface conduction electron-emitting device,
4 is a spacer, 5 is a hole which is an electron beam passing portion provided in the spacer 4, 8 is an envelope, and 10 is a phosphor target which is an image forming member.

In the present device, the surface conduction electron-emitting device 3 comprises a pair of opposing device electrodes 1 as shown in FIG.
4 and 15 and a thin film 13 including an electron emitting portion 12, and is disposed on the surface of the rear plate 2. The electron beam emitted from the electron-emitting portion is caused by the acceleration voltage applied between the rear plate 2 and the face plate 1 and the voltage applied between the device electrodes according to the trajectory indicated by the arrow in FIG. The phosphor reaches the upper phosphor target 10.

The inside of the apparatus is maintained in a vacuum state, which is the operating environment of the surface conduction electron-emitting device, and a plurality of spacers 4 for supporting the plates 1 and 3 are arranged.
As can be seen from FIG. 1, the spacer 4 is located at a position where the electron beam trajectory is obstructed. However, by providing the electron beam passage portion 5 in the spacer 4, the electron beam can reach the phosphor target without being obstructed on the way. It is configured. For this reason, an image display device with low power consumption and high light emission luminance without loss of electron beams and no breakdown due to charge-up of the spacer is realized.

In this embodiment, the electron beam passage portion is a circular hole, but a triangular or square hole may be used as long as the electron beam path is not hindered.

In addition, such a spacer is formed by:
a) A method in which unnecessary portions are removed by etching a plate-shaped photosensitive glass. b) A method of forming a plate-shaped blue plate glass or the like by removing unnecessary portions by RIE (reactive ion etching) or RIBE (reactive ion beam etching).

C) Press-forming or electric-discharge machining of a plate-like metal,
A method in which unnecessary parts are removed by cutting or the like, and an insulating film is finally applied.

D) A method of processing metal using a die processed so as not to provide a portion that blocks the electron beam orbit. Etc. can be used.

Since the electron beam emitted from the electron emitting portion gradually diverges as it approaches the phosphor screen, if the distance between the electron emitting portion and the spacer is small, the electron beam passing portion 5 has a small hole near the rear plate. It is only necessary to provide the spacer, and the sectional area of the spacer can be increased, so that the supporting withstand voltage of the spacer can be increased.

<Reference Example 2> FIGS. 3 and 4 are views showing the features of the image forming apparatus of this reference example. FIG. 3 shows a state where spacers are installed on each plate. FIG. The positional relationship with the element is shown.

In this embodiment, the electron beam passing portion 5 has a structure in which a portion of the spacer in contact with the rear plate is cut off, and as shown in FIG.
2 are arranged. For this reason, it is sufficient to provide a portion for passing electrons having a small spread immediately after exiting the electron-emitting portion 12, so that the supporting withstand voltage of the spacer can be further increased as compared with the first embodiment.

<Embodiment 3> FIGS. 5 and 6 are views showing the schematic arrangement of an image forming apparatus according to this embodiment. FIG. 5 is a sectional view taken along a plane perpendicular to each plate surface, and FIG. It is AA sectional drawing.

The difference from Reference Examples 1 and 2 is that a part of the upper part of the spacer 4 which is in contact with the face plate 1 is cut off to form an electron beam passing part 5. The electron beam trajectory (the trajectory indicated by the arrow in FIG. 5) and the spacer 4 of this reference example
In the positional relationship described above, since the spacer comes to the position where the electron beam collides with the phosphor target 10, a notch having a width equal to or larger than the pixel is provided, and the electron beam collides with the phosphor screen to form a pixel. It does not hinder.

<Embodiment 4> FIGS. 7 and 8 are views showing the schematic arrangement of an image forming apparatus according to this embodiment. FIG. 7 is a sectional view taken along a plane perpendicular to each plate surface. It is AA sectional drawing.

The difference from the first to third embodiments is that two orbits of the electron beam passing through the spacer 4 are present in the vertical direction, and an electron beam passage portion 5a formed of a square hole and a notch This is the point that the electron beam passing portion 5b made of

According to the present embodiment, the removed portion of the spacer member serving as the electron beam passage portion may have a configuration in which a plurality of positions shown in Reference Examples 1 to 3 are combined according to the positional relationship with the electron beam orbit. It is possible.

That is, when one spacer hinders the electron beam trajectories corresponding to the electron emission portions of a plurality of electron emission elements adjacent to the front, rear, left and right, one electron beam passage portion corresponding to each electron beam trajectory is provided. A plurality of spacers can be provided above, below, right and left of the spacer. Further, a configuration in which a single large electron beam passage portion passes through a plurality of electron beam orbits is also possible.

<Embodiment 1> In each of the above embodiments, a plate-shaped spacer is used. Before describing this embodiment, the effectiveness of using this plate-shaped spacer will be described. In the schematic configuration diagram of the image forming apparatus described above, the distance between the electron-emitting devices is relatively wide, but they are arranged very close to each other in order to obtain a high-brightness and high-definition image.

FIG. 9 is a diagram showing an example of an arrangement of electron-emitting devices in which it is particularly effective to use a plate-like spacer.
The electron-emitting devices 3 are arranged such that adjacent devices are shifted from each other by half a device. The dashed arrows in the figure indicate the trajectory direction of the electron beam emitted from the hatched element in the figure,
The same applies to the trajectory direction of the electron beam emitted from other elements.

Considering the direction in which the spacers can be arranged with respect to the electron-emitting devices arranged as shown in FIG. 9, when the spacers are arranged parallel to the electron beam orbit (X direction), Such an arrangement is inappropriate because the spacer is located on the track. On the other hand, in the direction orthogonal to this (Y direction), the ground plane of the spacer can be located between the elements (as an example, the position of the thick line in the figure), but interrupts the electron beam trajectory as indicated by the broken arrow. Would. Therefore, in Reference Examples 1 to 4, by removing a part of the plate-shaped spacer and providing the electron beam passage portion, the electron beam trajectory is not blocked even when the electron-emitting devices are arranged as described above. .

This embodiment is an example in which the above-mentioned plate-like spacer is fixed by a support member. When the above-mentioned plate-like spacer cannot stand on its own, for example, as shown in FIG. 10, both ends of the plate-like spacer 4 may be sandwiched from both sides by spacer support members 9 to fix the support member 9 to a rear plate or the like. it can. In this case, since the installation surface of the spacer supporting member 9 is wider than the gap between the elements, the image forming range (the element forming range of the rear plate) is limited, and the spacer supporting member 9 is provided outside the area.
By disposing them, it is possible to prevent the plate-shaped spacer from falling down without crushing the element.

The spacer supporting member 9 and the plate spacer 4 can be fixed with frit glass or the like. Further, in FIG. 10, the electron beam passing portion 5
As described above, the electron beam passage portions are provided at appropriate positions and in an appropriate number according to the positions of the electron-emitting devices and the phosphor targets.

<Embodiment 5> In this embodiment, an image forming apparatus is constructed by using a cross-shaped spacer instead of a plate-shaped spacer. FIG. 11 shows the shape and arrangement of the spacers in the present reference example. FIG. 11A is a plan view showing the positional relationship between the spacers and the electron-emitting portions of a large number of electron sources, and FIGS. 11B and 11C. () Is a side view of one spacer. Note that FIG. 11C also shows the electron emitting portion and the electron beam orbit.

As shown in FIG. 11 (b), the spacer of this embodiment has a part of the cross shape removed, and the dimension h in the figure is set to a certain height or less determined by the electron beam orbit.
As shown in (c), the electron beam orbit is formed so as not to be disturbed.

A method of forming a spacer in this embodiment will be described with reference to FIG. 12 (a) and 12 (b) are prepared, and three sheets of glass (may be metal or ceramic) are prepared. As shown in FIG. Are cut off with a grinder or the like to form an electron beam passage portion, and are bonded to each other with frit glass as shown in FIG. In addition, it is possible to process into a desired shape only by shaving a lump such as glass.

As described above, the spacer of the present embodiment has a cross-shaped installation surface with the rear plate and the face plate, and thus has a structure capable of standing on its own. Generally, it is preferable that the spacer used for supporting the atmospheric pressure of a good large-area high-density image display device has a self-standing structure. The reason is as follows. When a plate-like spacer which is difficult to stand on its own is used, it is necessary to provide a spacer support member as shown in FIG. 10 on the ground plane, and this spacer support member is located outside the image display area. Be placed. For this reason, in the large-area image display device, the individual spacers become long, and it is difficult to maintain the shape tolerance.

As described above, by using the spacer of this embodiment, it is possible to realize a particularly large-area image display device without hindering the trajectory of the electron beam.

Reference Example 6 FIG. 13 shows the shape and arrangement of the spacers in this reference example. FIG. 13A is a plan view showing a positional relationship between one spacer and four electron-emitting portions, and FIG. 3B is a perspective view of the spacer.

Since the spacer of this embodiment corresponds to the two-dimensional spread in the electron beam flight direction, the members shown in FIG. The processing as shown in (c) is applied to two places.

Also in this embodiment, since the spacer 4 is self-supporting, a large-area image display device can be realized as in the case of the fifth embodiment.

In the above embodiment, an example in which the image forming apparatus of the present invention is applied to an image display apparatus has been described. However, the present invention is not limited to this range, and a light emitting unit for image forming of an optical printer and the like can be used. Application to a recording device is also possible.

[0057]

As described above, according to the present invention,
By having a support member at the end so that it can stand on its own, it is possible to prevent the plate-shaped spacer from falling down, the length in the longitudinal direction is longer than the image forming range, and the support members are arranged at both ends in the longitudinal direction. Accordingly, a high-brightness, high-definition image forming apparatus can be realized without crushing the electron-emitting device.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view illustrating a schematic configuration of an image forming apparatus according to a first embodiment.

FIG. 2 is a cross-sectional view taken along the line AA of FIG.

FIG. 3 is a diagram illustrating an installation state of a plate and a spacer in the image forming apparatus shown in Reference Example 2.

FIG. 4 is a diagram showing a positional relationship between a spacer and an electron-emitting device in the image forming apparatus shown in Reference Example 2.

FIG. 5 is a cross-sectional view illustrating a schematic configuration of an image forming apparatus according to a third embodiment.

FIG. 6 is a cross-sectional view taken along the plane AA of FIG.

FIG. 7 is a sectional view illustrating a schematic configuration of an image forming apparatus according to a fourth embodiment.

8 is a cross-sectional view taken along the plane AA in FIG.

FIG. 9 is a diagram showing an example of an arrangement of electron-emitting devices and an installation position of a spacer.

FIG. 10 is a diagram for explaining a spacer supporting method described in the first embodiment.

FIG. 11 is a diagram showing the shape and arrangement of spacers in the image forming apparatus shown in Reference Example 5.

FIG. 12 is a diagram for explaining a method of forming a spacer in Reference Example 5.

FIG. 13 is a view showing the shape and arrangement of spacers in the image forming apparatus shown in Reference Example 6.

FIG. 14 is an example of a configuration diagram of a surface conduction electron-emitting device.

FIG. 15 is a configuration diagram of a device for evaluating characteristics of a surface conduction electron-emitting device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Face plate 2 Rear plate 3 Electron emission element 4 Spacer 5 Electron beam passage part 8 Enclosure 9 Spacer support member 10 Phosphor target 11 Insulating substrate 12 Electron emission part 13 Thin film 14 Element electrode (negative electrode) 15 Element electrode (positive electrode) ) 16 glass substrate 17 anode electrode 18 fluorescent film 19 power supply 20 high voltage power supply

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Tomokazu Ando 3-30-2 Shimomaruko, Ota-ku, Tokyo Inside Canon Inc. (72) Inventor Masahiro Tagawa 3-30-2 Shimomaruko, Ota-ku, Tokyo Within Non Co., Ltd. (72) Inventor Naoto Nakamura 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (72) Inventor Hideaki Mitsutake 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (72) Inventor Yoshiyuki Nagata 3-30-2 Shimomaruko, Ota-ku, Tokyo F-term in Canon Inc. (reference) 5C032 AA01 CC10 5C036 EE05 EE19 EF01 EF06 EF09 EG02 EH01

Claims (4)

[Claims] 1. A plate-like spacer for defining an interval between a rear plate on which an electron-emitting device is arranged and a face plate on which an image forming member is arranged, and which is capable of standing independently.
A spacer having a support member at an end. 2. The spacer according to claim 1, wherein the length in the longitudinal direction is longer than the image forming range, and the support members are arranged at both ends in the longitudinal direction. 3. The spacer according to claim 2, wherein the image forming range is a range in which the electron-emitting devices arranged on the rear plate are arranged. 4. The spacer according to claim 1, wherein both side surfaces are sandwiched by a pair of said support members.