JPH087794A - Image forming device - Google Patents

Abstract

(57) [Summary] [Purpose] Has a sufficiently strong support structure against atmospheric pressure,
It is an object of the present invention to provide an image forming apparatus which prevents image deterioration such as uneven brightness, uneven color, and crosstalk, and has high exhaust efficiency. An electron emitting device 35, an image forming member 39 for forming an image by irradiation of an electron beam emitted from the electron emitting device, and a supporting member 4 for supporting the envelope are provided in the envelope.
In the image forming apparatus having
However, the image forming apparatus is characterized in that it has conductivity and is provided with a hole 44.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus such as a display device using an electron-emitting device, and particularly, in the device,
The present invention relates to an image forming apparatus in which a supporting member called a spacer is arranged.

[0002]

2. Description of the Related Art Conventionally, two types of electron emitters, a thermoelectron 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 type electron emitting device, and the like.

An example of the above-mentioned FE type is W.P.Dyk
e & W.W. Dolan, "Field emissi"
on ”, Advance in Electron P
hysics, 8, 89 (1956) or C.
A. Spindt, "PHYSIACL Proper
ties of thin-film field e
Mission cathodes with mol
ybdenum cones ”, J. Appl. Phy
S., 47, 5248 (1976) and the like.

An example of the above MIM type is CA Me.
ad, "The tunnel-emission a
mplifer, J. Appl. Phys., 32,
646 (1961) and the like are known.

As examples of the surface conduction electron-emitting device, MI Elinson and Radio Eng.
Electron Pys., 10, (1965) and the like.

The surface conduction electron-emitting device utilizes a phenomenon in which electron emission occurs when a current is passed through a thin film of a small area formed on a substrate in parallel with the film surface. As the surface conduction electron-emitting device, one using a SnO ₂ thin film according to the above-mentioned E. Elinson, one using an Au thin film [G. Dittme
r: "Thin Solid Films", 9, 31
7 (1972)], by In ₂ O ₃ / SnO ₂ thin films [M. Hartwell and C. G. Fons].
tad: "IEEE Trans. ED Conf.
, 519 (1975)], by carbon thin film [Hiraki Araki et al .: Vacuum, Vol. 26, No. 1, p. 22 (19)
83)] etc. have been reported.

As a typical device structure of these surface conduction electron-emitting devices, the above-mentioned M. Hartwell (M.Ha
FIG. 11 shows the device configuration of (rtwell).

In FIG. 11, reference numeral 111 is a substrate, and 114 is a conductive film, which is composed of a metal oxide thin film or the like formed by sputtering in an H-shaped pattern, and is subjected to an electric current treatment called an electric current forming, which will be described later. Ejection unit 115
Is formed. The element electrode distance L in FIG. 11 is 0.5.
.About.1.0 mm and W'is set to 0.1 mm. Further, since the position and shape of the electron emitting portion 115 are unknown, it is shown as a schematic diagram.

Conventionally, in these surface conduction electron-emitting devices, as described above, the electron-emitting portion 115 is generally formed on the conductive film 114 by an energization process called energization forming before the electron emission. Met.

That is, the energization forming means that a direct current voltage or a very slow rising voltage, for example, about 1 V / min is applied to both ends of the conductive film 114 to energize the conductive film 114 to locally break, deform, or deform the conductive film. The purpose is to form the electron emitting portion 115 that has been altered to have an electrically high resistance state. Note that, for example, the electron emitting portion 115 has a conductive film 114.
Has a crack generated in a part of it, and electrons are emitted from the vicinity of the crack. In the surface conduction electron-emitting device that has been subjected to the energization forming treatment, a voltage is applied to the conductive film 114 and a current is passed through the device, so that the electron-emitting portion 1 is formed.
The electron is emitted from 15.

Among the electron-emitting devices described above, in particular,
The surface conduction electron-emitting device has an advantage that a large number of the devices can be formed in an array over a large area because of its simple structure and easy manufacture. Therefore, various applications that can make use of such advantages are being studied. Examples thereof include a charged beam source and a self-luminous display device.

As an example in which a large number of surface-conduction type electron-emitting devices are formed in an array, the surface-conduction type electron-emitting devices are arranged in parallel and both ends of each of the devices are connected by wiring (also called common wiring). An electron source in which a large number of rows are arranged (for example, Japanese Patent Laid-Open No. 64-31332,
JP-A-1-283749, JP-A-1-25755
No. 2, etc.).

As an example of the self-luminous display device, a display device in which a large number of surface conduction electron-emitting devices are arranged and an electron source is combined with a phosphor that emits visible light by the electrons emitted from the electron source. The image forming apparatus is as follows (US Pat. No. 5,066,883).

In particular, in image forming apparatuses such as display devices, in recent years, flat panel display devices using liquid crystal have become widespread in place of CRTs. Flat panel display devices using this liquid crystal are self-luminous. Therefore, there is a problem that a backlight must be provided, and it has been desired to develop a self-luminous display device using the electron-emitting device as in the above-mentioned example.

[0015]

However, the above-mentioned display device has the following problems.

9 and 10 show an example of a display device in which a supporting member is arranged inside the envelope. Here, 101 is a rear plate, 111 is an outer frame, and 109 is a face plate, which form an envelope and hold the inside of the envelope in vacuum.

Further, 103a and 103b are electrodes, 10
Reference numeral 4 denotes an electron emitting portion, which allows the electron emitting device 10
5 is formed.

Further, 102a (scan electrodes), 102b
(Information signal electrode) is a wiring electrode, and each electrode 10
3a and 103b.

Further, 106 is a glass substrate, 107 is a transparent electrode, 108 is a phosphor (image forming member), and a face plate 109 is formed by these.

Further, 112 is a bright spot of the phosphor, and 11
Reference numeral 0 is a support member for mainly supporting the atmospheric pressure applied to the rear plate 101 and the face plate 109 from the inside of the envelope.

The display device as described above has the scanning electrodes 102a and the information signal electrodes 10 arranged in the XY matrix.
By applying a predetermined signal voltage to 2b, an electron beam corresponding to an information signal is made to collide with the phosphor 108, which is an image forming member, to form an image.

Here, in the image forming apparatus as described above, when the supporting member 110 is formed of an insulating member in particular, an unexpected electron beam or ion collides with the supporting member 110 when the apparatus is driven. By doing so, the surface of the supporting member is charged, and (1) the orbit of the electron beam is bent by the charging of the supporting member, and the irradiation amount of the electron beam to the desired phosphor in the pixel is changed to Unevenness and color unevenness occur. Further, when the charge amount is large, the electron beam does not collide with a desired fluorescent substance, which causes unexpected irradiation of the fluorescent substance adjacent thereto and causes crosstalk. (2) Since the charge amount of the supporting member changes with time, the trajectory of the electron beam changes with time, which causes fluctuation in luminance with time. (3) A discharge is generated from the charged support member, the electron-emitting device is damaged by this discharge, and the electrical insulation of the support member is deteriorated.

On the other hand, as a method for preventing the charging of the supporting member as described above, the supporting member is provided with conductivity, and further,
There is a method of setting the surface of the supporting member to a specific potential (for example, Japanese Patent Laid-Open No. 4-212435).

However, when the support member is a plate-shaped member as shown in FIG. 9 and has a high support strength but a shape that hinders vacuum exhaust in the envelope, the time required for exhaust is long. The exhaust efficiency is poor. Further, there is a problem that the display image is deteriorated if the exhaust is insufficient.

As described above, the present invention has a sufficiently strong support structure against atmospheric pressure, prevents image deterioration such as brightness unevenness, color unevenness, and crosstalk, and has high exhaust efficiency. An object is to provide an image forming apparatus.

[0026]

According to the present invention to achieve the above object, an electron-emitting device and an image forming member for forming an image by irradiation of an electron beam emitted from the electron-emitting device are provided in an envelope. An image forming apparatus having a supporting member for supporting the envelope is characterized in that the supporting member has conductivity and is provided with a hole.

Further, in the present invention, preferably, in order to regulate the potential of the supporting member, there is provided a potential regulating means for applying a predetermined voltage to the supporting member.

Further, in the present invention, preferably, in order to apply a predetermined voltage to the support member, an external power source for applying a specific potential is connected to the support member, or the support member is an element electrode. It is arranged to be electrically connected to.

Further, in the present invention, preferably, the hole provided in the support member has an elliptical shape having its major axis in the supporting direction of the envelope.

By adopting the above-mentioned constitution of the present invention, not only can it have a sufficiently strong support structure against atmospheric pressure and can prevent image deterioration such as brightness unevenness, color unevenness, and crosstalk, and also exhaust gas. It is possible to provide an image forming apparatus with high efficiency and exhaustion.

Further, the electron-emitting device particularly preferably used in the above-mentioned present invention basically has a structure as described below, and includes a flat surface conduction electron-emitting device and a vertical surface conduction electron-emitting device. The emission elements are roughly classified into two.

As described above, among the electron-emitting devices, the surface conduction electron-emitting device, in particular, has a simple structure and is easy to manufacture. It has an advantage that elements can be formed in an array, and an image forming apparatus such as a display device is a mode in which such advantages can be fully utilized.

First, the planar surface conduction electron-emitting device will be described.

FIGS. 1A and 1B are a schematic plan view and a cross-sectional view showing the basic structure of a planar surface conduction electron-emitting device, respectively. In FIG. 1, 1 is a substrate, 2 and 3 are device electrodes, 4 is a conductive film, and 5 is an electron emitting portion.

Examples of the substrate 1 include quartz glass, glass with a reduced content of impurities such as Na, soda-lime glass, a soda glass substrate laminated with SiO ₂ formed on the soda-lime glass by a sputtering method, and ceramics such as alumina. Can be mentioned.

The material of the opposing device electrodes 2 and 3 is as follows.
Common conductor materials are used, such as Ni, Cr, A
Metals or alloys such as u, Mo, W, Pt, Ti, Al, Cu, Pd, and Pd, Ag, Au, RuO ₂ , Pd.
- metal or metal oxide such as Ag, printed conducting materials made of glass or the like is appropriately selected from a semiconductor conductive material such as a transparent conductor and polysilicon or the like In ₂ O ₃ -SnO ₂ or the like.

The element electrode spacing L, the element electrode length W, the shape of the conductive film 4 and the like are appropriately designed according to the application form of the electron-emitting device, but the element electrode spacing L is preferably
It is from several hundred angstroms to several hundreds of micrometers, and more preferably from several micrometers to several tens of micrometers depending on the voltage applied between the device electrodes and the electric field strength capable of emitting electrons.

The order of laminating the conductive film 4 and the device electrodes 2 and 3 is not limited to the mode shown in FIG. 1, and the conductive film 4 and the opposing device electrodes 2 and 3 are laminated on the substrate 1 in this order. It may be configured.

The conductive film 4 is particularly preferably a fine particle film composed of fine particles in order to obtain good electron emission characteristics. The thickness of the conductive film 4 depends on the step coverage of the device electrodes 2 and 3, the device electrode 2, It is appropriately set depending on the resistance value between the three and the energization forming conditions described above, and is preferably several angstroms to several thousand angstroms, particularly preferably 10 angstroms to 500 angstroms, and the resistance value is 10 ³ to 10 ⁷ ohm /
It is the sheet resistance value of □.

The material forming the conductive film 4 is P
d, Ru, Ag, Au, Ti, In, Cu, Cr, F
e, Zn, Sn, Ta, W, Pb and other metals, PdO, S
oxides such as nO ₂ , In ₂ O ₃ , PbO and Sb ₂ O ₃ ;
HfB ₂ , ZrB ₂ , LaB ₆ , CeB ₆ , YB ₄ , G
Borides such as dB ₄ , TiC, ZrC, HfC, TaC,
Examples thereof include carbides such as SiC and WC, nitrides such as TiN, ZrN and HfN, semiconductors such as Si and Ge, and carbon.

The fine particle film described here is a film in which a plurality of fine particles are aggregated, and its fine structure is not only a state in which the fine particles are dispersed and arranged but also a state in which the fine particles are adjacent to each other or overlap each other ( The particle size of the fine particles is from several angstroms to several thousand angstroms, preferably 10 angstroms to 200 angstroms.

The electron-emitting portion 5 is, for example, a high-resistance crack formed in a part of the conductive film 4, and depends on the film thickness, film quality, material of the conductive film 4 and the manufacturing method such as the above-mentioned energization forming. Formed. Further, it may have conductive fine particles having a particle size of several hundred angstroms to several hundred angstroms. The conductive fine particles contain some or all of the elements of the material forming the conductive film 4. Further, the electron emitting portion 5 and the conductive film 4 in the vicinity thereof may contain carbon and a carbon compound.

Next, the vertical surface conduction electron-emitting device will be described.

FIG. 2 is a schematic cross-sectional view showing the basic structure of the vertical surface conduction electron-emitting device, and the members with the same reference numerals as those in FIG. 1 are the same as those in FIG.

The substrate 1, the device electrodes 2 and 3, the conductive film 4,
The electron emitting portion 5 is made of the same material as that of the above-mentioned flat surface conduction electron-emitting device, but the step forming portion 21 is formed by a vacuum vapor deposition method, a printing method, a sputtering method or the like. It is made of an insulating material such as SiO _2, and the film thickness of the step forming portion 21 corresponds to the device electrode interval L of the flat surface conduction electron-emitting device described above, and is several hundred angstroms to several tens of micrometers. However, the thickness is appropriately set depending on the manufacturing method of the step forming portion, the voltage applied between the device electrodes and the electric field strength capable of emitting electrons, but is preferably several hundred angstroms to several micrometers.

Since the conductive film 4 is formed after the device electrodes 2 and 3 and the step forming portion 21 are formed, it is laminated on the device electrodes 2 and 3. Although the electron emitting portion 5 is shown as a straight line in the step forming portion 21 in FIG. 2, its shape and position are not limited to this, depending on the manufacturing conditions and the energization forming conditions described above. is not.

The surface conduction electron-emitting device as described above is
1) When a device voltage (threshold voltage) of a certain value or more is applied, the emission current rapidly increases, while at the threshold voltage or less, the emission current is hardly detected. That is, it is a non-linear element having a clear threshold voltage with respect to the emission current. 2) Since the emission current depends on the device voltage monotonically, the emission current can be controlled by the device voltage. 3) The amount of charge trapped in the anode electrode (member irradiated with the electron beam) depends on the time for which the device voltage is applied, so the amount of charge trapped in the anode electrode is controlled by the time for which the device voltage is applied. it can.
Since it has characteristic properties such as, the electron emission characteristics can be easily controlled even in an electron source and an image forming apparatus in which a plurality of electron emission elements are arranged according to an input signal, and it can be applied to various fields. .

The operation of driving the surface conduction electron-emitting device is preferably carried out in an atmosphere of a high degree of vacuum, for example, a degree of vacuum of 10 ⁻⁶ torr or more.

[0049]

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

(Embodiment 1) FIGS. 3 and 4 show an image forming apparatus according to a first embodiment of the present invention. 3 is a schematic perspective view of the image forming apparatus, and FIG. 4 is a sectional view taken along the line AA 'of FIG.

In the figure, 31 is a rear plate, 41 is an outer frame,
Reference numeral 39 denotes a face plate, which forms an envelope.

Further, 34 is an electron emitting portion, 33a and 33.
b is an electrode for applying a voltage to the electron emitting portion,
These form the electron-emitting device 35. The electron-emitting device in this embodiment is the above-mentioned plane type surface conduction electron-emitting device.

Further, 32a and 32b are wiring electrodes, in particular, 32a is used as a scanning electrode and 32b is used as an information signal electrode, which are electrically connected to the electrodes 33a and 33b, respectively. Although not shown, these wiring electrodes 32a and 32b are provided with an interlayer insulating member which electrically insulates between the wiring electrodes at their intersections. Further, in the present invention, the electrodes 33a and 33
b, the wiring electrodes 32a and 32b are collectively referred to as device electrodes.

Further, 36 is a glass substrate, 38 is a phosphor (image forming member), 37 is a transparent electrode for applying a voltage to the phosphor, and these forms the face plate 39.

Reference numeral 40 denotes a support member for supporting the atmospheric pressure applied to the envelope, which is an insulating member 4 such as glass.
A conductive film 40b made of metal or the like is formed on the surface of 0a. Further, 43 is a power supply for applying a predetermined potential to the conductive support member 40.

As shown in the figure, the electron-emitting device 35 and the phosphor 38 which is an image forming member are arranged on opposing base bodies (rear plate 31 and glass substrate 36) in the envelope, Further, the conductive support member 40 is arranged between the rear plate 31 and the face plate 39 so as to support the atmospheric pressure applied to the rear plate 31 and the face plate 39. However, as shown in FIG. 4, the conductive support member 40 is arranged on the rear plate 31 between the electron-emitting devices 35 on the rear plate side, and on the face plate side, the phosphor 38 and the transparent material. It is arranged in a state of being electrically non-contact with the electrode 37, and the potential of the conductive support member 40 is regulated by the potential applied from the power source 43.

Further, the conductive support member 40 is provided with a plurality of holes 44. This hole is for improving the exhaust efficiency when the inside of the envelope is evacuated, and the time required for exhaust is significantly shorter than that in the case without the hole. Further, the shape of the hole is circular in the present embodiment, but the shape is not limited to this, and may be another shape such as a quadrangle or a hexagon, and the shape and size, the position to be provided, the number of holes, etc.
It is appropriately set within a range in which a sufficient atmospheric pressure resistance supporting function is obtained.

The above-mentioned conductive support member is prepared by, for example, etching a plate-like photosensitive glass to remove unnecessary portions (holes), or plate-like blue plate glass by RIE (reaction). Ion etching) and RIBE
Is it made by partially covering a conductive film such as a metal by vacuum deposition etc. on an insulating member with holes formed by methods such as removing unnecessary parts by (reactive ion beam etching)? Alternatively, the plate-shaped metal is formed by removing unnecessary portions (hole portions) by press working, electric discharge machining, cutting, etc., and then covering the necessary portions with an insulating member.

According to the image forming apparatus of this embodiment described above,
It is possible to prevent uneven brightness and changes in brightness over time, and it is possible to form an extremely stable luminescent image. Moreover, it is possible to prevent electric discharge that would cause fatal damage to the electron-emitting device during driving of the device, and it is possible to display an image with a long life.

(Embodiment 2) FIGS. 5 and 6 show an image forming apparatus according to a second embodiment of the present invention. 5 is a schematic perspective view of the image forming apparatus, and FIG. 6 is a sectional view taken along the line AA 'of FIG.

In the present embodiment, the conductive support member 40 is arranged on the wiring electrode 32a and electrically connected to the wiring electrode 32a, and the surface thereof has the same potential as the wiring electrode 32a. The same as in Example 1. Incidentally, FIG.
In the figure, 45 is an interlayer insulating member for electrically insulating both wiring electrodes 32a and 32b.

Also in this example, the same effects as in Example 1 were confirmed, unevenness in luminance and changes in luminance over time could be prevented, and an extremely stable luminescent image could be formed. Moreover, it is possible to prevent electric discharge that would cause fatal damage to the electron-emitting device during driving of the device, and it is possible to display an image with a long life. Further, the time required for the exhaust of the air inside the envelope is much shorter than that for the case where a conductive support member having no hole 44 is used.

(Embodiment 3) FIGS. 7 and 8 show an image forming apparatus according to a third embodiment of the present invention. 7 is a schematic perspective view of the image forming apparatus, and FIG. 8 shows the conductive supporting member 40.
It is a top view seen from the arrow direction.

In the present embodiment, the shape of the hole 54 provided in the conductive support member 40 is a vertically long ellipse, that is, an ellipse having its long axis in the supporting direction (the direction perpendicular to the rear plate 31 and the face plate 39). The same as Example 1 except for the above.

In this example, the same effects as in Example 1 were confirmed, uneven brightness and change in brightness over time could be prevented, and an extremely stable luminescent image could be formed. Moreover, it is possible to prevent electric discharge that would cause fatal damage to the electron-emitting device during driving of the device, and it is possible to display an image with a long life. Further, the time required for the exhaust of the air inside the envelope is much shorter than that for the case where a conductive support member having no hole 54 is used. Furthermore, in this embodiment,
As compared with the case where the hole 54 is a perfect circle, the strength in the supporting direction is improved.

In this embodiment, the voltage applying means by the power source 43 is used as the means for defining the potential of the conductive support member 40. However, as described in the second embodiment,
Alternatively, it may be electrically connected to the element electrode (wiring electrode 32a) so that the conductive support member and the element electrode have the same potential.

[0067]

According to the present invention described above, it has a sufficiently strong support structure against atmospheric pressure, and can prevent image deterioration such as brightness unevenness, color unevenness, and crosstalk, as well as exhaust gas. It is possible to provide an image forming apparatus with high efficiency and exhaustion.

[Brief description of drawings]

FIG. 1 is a schematic plan view (a) and sectional view (b) showing the basic structure of a surface conduction electron-emitting device that is preferably used in the present invention.

FIG. 2 is a schematic cross-sectional view showing another embodiment of a surface conduction electron-emitting device that is preferably used in the present invention.

FIG. 3 is a perspective view showing the image forming apparatus according to the first embodiment of the present invention.

FIG. 4 is a cross-sectional view taken along the line A-A ′ of the image forming apparatus in FIG.

FIG. 5 is a perspective view showing an image forming apparatus according to a second embodiment of the present invention.

6 is a cross-sectional view taken along the line A-A 'of the image forming apparatus in FIG.

FIG. 7 is a perspective view showing an image forming apparatus according to a third embodiment of the present invention.

8 is a plan view of the support member as seen from the direction of the arrow in FIG.

FIG. 9 is a perspective view showing an example of an image forming apparatus in which a supporting member is provided inside the apparatus.

10 is a cross-sectional view taken along the line A-A ′ of the image forming apparatus in FIG.

FIG. 11 is a schematic plan view of a conventional surface conduction electron-emitting device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1,111 Substrate 2,3 Element electrode 4,114 Conductive film 5,34,104,113 Electron emission part 21 Step formation member 31,101 Rear plate 32a, 32b, 102a, 102b Wiring electrode 33a, 33b, 103a, 103b Electrodes 35,105 Electron emitting devices 36,106 Glass substrates 37,107 Transparent electrodes 38,108 Phosphors 39,109 Face plates 40,110 Supporting members 40a Insulating members 40b Conductive films 41,111 Outer frames 42,112 Bright spots 43 External power supply 44, 54 holes

Claims (7)

[Claims] 1. An envelope has an electron-emitting device, an image forming member that forms an image by irradiation of an electron beam emitted from the electron-emitting device, and a support member that supports the envelope. In the image forming apparatus, the supporting member has conductivity and is provided with a hole. 2. The image forming apparatus according to claim 1, further comprising potential defining means for defining a potential of the supporting member. 3. The image forming apparatus according to claim 2, wherein the potential regulating unit is a voltage applying unit that applies a voltage to the supporting member. 4. The image forming apparatus according to claim 3, wherein the voltage applying unit is an external power source. 5. The image forming apparatus according to claim 3, wherein the voltage applying unit is an element electrode. 6. The image forming apparatus according to claim 1, wherein the hole has an elliptical shape having a major axis in a supporting direction of the envelope. 7. The image forming apparatus according to claim 1, wherein the electron-emitting device is a surface conduction electron-emitting device.