JPH02299136A - Image forming device - Google Patents

Abstract

PURPOSE:To obtain stable luminescence with no deterioration of the luminescence effect by providing atmospheric pressure-resistant spacers along the orbit of electrons emitted from surface conductive type electron emitting elements. CONSTITUTION:A thin film 3 made of an electron emitting material having a neck section is formed on a quartz substrate 4. Electrodes 1 and 2 having electric connection to electron emission sections 5 to be provided on the film 3 are formed. The electron emission sections 5 are formed between the electrode 1 and the electrode 2. A phosphor target 7 is arranged on spacers 11. When such spacers 11 are provided, the surface breakdown voltage is increased, the arriving current quantity to the target 7 has no loss, and luminescence with high efficiency and high brightness is obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to an image forming apparatus using surface conduction electron-emitting devices.

[Prior Art] Conventionally, as an element that can emit electrons with a simple structure, for example, "Radio Engineering Electron Physics"
ron, Phys, ) J 1965, Volume 10, 12
A cold cathode element named No. 90-1296 is known.

This utilizes the phenomenon that electron emission occurs when a current is passed through a small-area thin film formed on a substrate parallel to the film surface, and is generally called a surface conduction type emission device.

Examples of this surface conduction type emission device include those using the SnO□(sb) thin film developed by Ellingson et al.
“ThinSolid Films”
Films) J, 1972, Vol. 9, p. 317, using Au thin films announced by G. Dittmer,
EE Trans.

ED Conf, N 1975 edition, p. 519, Hartwell (M) and Fonstad (C)
, G., Fonstad) and a carbon thin film published by Hisashi Araki et al. in ``Vacuum J, Volume 26, No. 1, Page 22, 1983.

The typical device configuration of these surface conduction type emitters is shown in the first section.
As shown in the figure. In FIG. 1, 1 and 2 are electrodes for obtaining electrical connection, 3 is a thin film formed of an electron-emitting material, is a substrate, and 5 is an electron-emitting part.

Conventionally, in these surface conduction type emitting devices, an electron emitting portion is formed in advance by an electrical heating process called forming before electron emission. That is, by applying a voltage between the electrodes 1 and 2, electricity is applied to the thin film 3, and the Joule heat generated thereby locally destroys, deforms, or alters the thin film 3, resulting in a high electrical resistance. The electron emitting function is obtained by forming the electron emitting portion 5 in the state.

Furthermore, a substrate coated with a phosphor is used on the element so that the radiation characteristics of the electron emission of the element, that is, the area in which the emitted electrons spread can be visually measured.
1 is a phosphor substrate, and 7 is a light emitting part that emits light by emitted electrons.

The radiation characteristics of electron emission of the above element are several mm from the above element.
A phosphor substrate 6 is placed in a space separated by a certain distance, a voltage of several hundred volts to several thousand volts is applied, and a driving voltage is applied between the electrode 1 and the electrode 2 to cause electron emission. is placed on the phosphor substrate 6 as shown in FIG. Fly.

The above-mentioned radiation characteristic is an inherent characteristic of a surface conduction type electron-emitting device including the above-mentioned device, in which the potential is not symmetrical within the same plane.

[Problems to be Solved by the Invention] As described above, in a surface conduction electron-emitting device in which the potentials are not symmetrical within the same plane, the electron beam emitted from the electron-emitting part is connected to the positive electrode of the potential applied to the device. Fly off to the side. Further, since the element is operated in a vacuum of about I x 10-'torr or higher, when forming an image forming apparatus using the element, it is necessary to construct an atmospheric pressure resistant spacer. Conventionally, the atmospheric pressure spacer was formed perpendicularly to the element, resulting in the following drawbacks.

(1) The emitted electron beam collides with the atmospheric pressure resistant spacer on the positive electrode side, reducing the amount of current reaching the phosphor target and reducing luminous efficiency.

(2) Creeping voltage is lowered due to charge-up on the atmospheric pressure resistant spacer, causing creeping discharge and destruction of the element.

(3) If the elements are arranged in a configuration that prevents a decrease in luminous efficiency and creeping discharge, it is not possible to construct an image forming apparatus in which multiple elements are arranged at high density.

Due to the above-mentioned problems, conventional surface conduction electron-emitting devices have a simple device structure and are easy to arrange two or more devices in a line. However, it has not yet been actively applied in industry.

[Means and Effects for Solving the Problems] The object of the present invention is to provide an image forming apparatus that solves the above-mentioned conventional drawbacks.

The means taken in the present invention to achieve the above object are:
This is to provide an atmospheric pressure resistant spacer which is laminated in a tapered, curved or patterned manner along the trajectory of the electron beam emitted from the surface conduction type electron-emitting device. This secures the trajectory of the electron beam, increases the creepage pressure due to the longer creepage distance, reduces luminous efficiency due to collision of the electron beam with the atmospheric pressure resistant spacer, and also reduces charge-up of the atmospheric pressure resistant spacer. Creeping discharge due to a drop in creeping withstand voltage is eliminated. Furthermore, due to the increase in creepage breakdown voltage, the acceleration voltage can be increased, and a light emitting section with higher efficiency and brightness can be obtained.

[Examples] Example 1 The present invention will be described in detail below using examples shown in the drawings.

FIG. 1 and FIG. 2 are explanatory diagrams showing one embodiment of the present invention. In FIG. 1, 4 is an insulating substrate;
is a thin film formed of an electron-emitting material, 1 and υ2 are electrodes for obtaining electrical connection, 5 is an electron-emitting part formed in the thin film 3, and 7 is arranged above the space of the electron-emitting element. A phosphor target, 8 is a light emitting part that emits light on the phosphor target 7, 9 is a drive power source for driving the element, 10 is a
This is an accelerating power source for causing the electron beam irradiated from the electron emitting section 5 to reach the phosphor target 7.

In FIG. 1, a quartz substrate is used as an insulating substrate 4, and a thin film 3 having a thickness of 1000 is formed on the cleaned quartz substrate 4 using InzOs as an electron emitting material. Other electron emitting materials include metal oxides such as SnO□ and pbo;
Metals such as Au and Ag, carbon, and various other semiconductors can be used. Next, by photolithography technology, the electron emission part 5 is formed L=1.
A thin film 3 of electron-emitting material is formed with a neck of 0 mm and V/ = 0.3 mm.

Next, Ni is used for the electrode 1.2 for electrical connection with the electron emitting portion 5 formed in the thin film 3, and a film thickness of 1500 mm is formed by mask evaporation. As the conductive material for the electrode 1.2, other ordinary metal materials such as Pu, Au, Cu, and A1 can be used.

By applying a voltage of about 30V between the electrodes 1 and 2, the thin film 3 is energized, and the Joule heat generated thereby causes the thin film 3 to be locally destroyed, deformed, or altered, resulting in an electrically high An electron emitting section 5 in a resistive state is formed.

Next, a transparent electrode ITO (In
sOx:5nOz=95:5) was formed by vapor deposition, and a phosphor target 7 formed by applying a phosphor that emits light by electrons was placed.

As described above (the radiation characteristics of the electron beam emitted from the configured element are measured using the phosphor target 7. First, the phosphor target 7 is connected to the IKV
Apply accelerating voltage. Next, a drive voltage of 18 V is applied to the electrodes 1 and 2 of the element by the drive power supply 9 so that the electrode 2 has a positive potential.

As shown in FIG.
get.

The light emitting part 8 emitted by the above element has a length X in the parallel direction to the electron emitting part 5 of about 4.0 mm, a length Y in the perpendicular direction of about 2.0 mm, and a normal line of the electron emitting part 5. , electrode 2
side, that is, the amount of deviation ΔY toward the positive electrode side with respect to the applied voltage
showed a characteristic of about 2.0 mm.

FIG. 2 shows a cross-sectional view of an image forming apparatus constructed by an element having the above radiation characteristics and an atmospheric pressure resistant spacer.

In FIG. 2, a quartz substrate is used as the insulating substrate 4, the above-mentioned element is placed on the substrate 4, and the distance between the electron emitting parts 5 is 6.0 m+.
The electrodes 1.2 were bound, formed into a multi-layered structure, and placed, and an atmospheric pressure resistant spacer 11 made of photosensitive glass was formed on the electrode 1.2 into a four-tiered structure. In this embodiment, the first stage width=2.
0mm, height = 0°5mm, 2nd step width = 1.6mm height = 0.5mm, 3rd step width = 1.2mm, height = 1.0+
nm, fourth stage width = L, Omm, and height = 2.0 mm.

Further, the atmospheric pressure resistant spacer 11 may be made of an insulating material such as glass formed by a printing method. Next, the phosphor target 7 is placed on the atmospheric pressure resistant spacer 11.

As described above (apply acceleration voltage IKV to the phosphor target 7 of the constructed image forming apparatus, drive voltage 1 to electrode 1.2).
When 8 V was applied, it was possible to obtain a light-emitting section in which the light-emitting state of the phosphor target 7 did not change, that is, the light-emitting efficiency did not decrease.

Furthermore, since the atmospheric pressure resistant spacer 11 is formed in a stepped shape, the creepage distance, that is, the creepage withstand voltage is high. (I was able to form an image.

Furthermore, according to this embodiment, since the atmospheric pressure resistant spacer 11 is formed symmetrically, no matter which side of the electrode 1.2 has a positive potential, it will not affect the atmospheric pressure resistant spacer 11 in any way. The image forming apparatus is not configured.

Example 2 A second embodiment of the present invention is shown in FIGS. 3 and 4.

In FIG. 3, a quartz substrate is used as the insulating substrate 4,
On the cleaned quartz substrate 4, using Ni as the electrode 1.2,
A film with a thickness of 1000 mm was formed by EB evaporation, and the electron emission part 5 was formed by photolithography technology, W = 0.3.
An electrode portion having a shape of 0.005 mm is formed between the electrodes 1.2.Next, a SnO□1 dispersion (Snow : IL solvent MEK/cyclohexane = 382 1000 cc, butyral: 1 g) was applied by a spin code method, and heat treated at 250 ° C.
Form.

Next, a phosphor target 7 similar to that in Example 1 is placed and configured in a space of H" 5 mm of the above element, and the radiation characteristics of the electron beam emitted from the element are measured using the phosphor target 7. First, an accelerating voltage of IKV is applied to the phosphor target 7 by the accelerating power source 10. Next, a driving voltage of 14 V is applied to the electrodes 1.2 of the element by the driving power source 9 so that the electrodes 2 are at a positive potential. The element to which a driving voltage is applied irradiates an electron beam onto the phosphor target 7 to obtain a light emitting section 8 as shown in FIG.

The light emitting part 8 emitted by the above element has a length X in a direction parallel to the electron emitting part 5 of approximately 2.0 mm, and a length Y in a perpendicular direction.
is approximately 1.5 mm, and the amount of deviation △Y toward the electrode 2 side with respect to the normal line of the electron emitting part 5, that is, toward the positive electrode side with respect to the applied voltage is approximately 1.
．． It showed the characteristics of 0 mm.

FIG. 4 shows a cross-sectional view of an image forming apparatus constructed of an element having the above radiation characteristics and an atmospheric pressure resistant spacer.

In FIG. 4, a quartz substrate is used as the insulating substrate 4, the above-mentioned elements are formed and arranged in a multi-layered manner on the substrate 4 with an interval of 3.0 mm between the electron emitting parts 5, and a photosensitive glass is placed on the electrode 1.2. An atmospheric pressure resistant spacer 11 consisting of a width=1. 0 mm, height = 5.0 mm, angle θ = 78°, it may be formed into a tapered shape by photolithography and curved along the trajectory of the emitted electron beam. ) The phosphor target 7 is placed on the atmospheric pressure resistant spacer 11.

An accelerating voltage IKV is applied to the phosphor target 7 of the image forming apparatus configured as described above, and a driving voltage 14 is applied to the electrode 1.2.
When V was applied, it was possible to obtain a light emitting section in which the light emitting state of the phosphor target 7 did not change, that is, the light emitting efficiency did not decrease. Furthermore, the atmospheric pressure resistant spacer 11 is no longer irradiated with the electron beam.
A device was obtained in which there was no charge-up in the atmospheric pressure resistant spacer 11 and no creeping discharge occurred.

Furthermore, when a similar structure is constructed using a conventional rectangular atmospheric pressure resistant spacer, the distance between the electron emission parts 5 must be 4 mm or more, but according to this embodiment, the distance between the electron emission parts 5 is 3 mm or more. This makes it possible to wire multiple electron-emitting devices at a higher density than in the past.

[Effects of the Invention] As explained above, according to the present invention, an atmospheric pressure resistant spacer for an image forming apparatus using surface conduction electron-emitting devices can be
By stacking the layers in a tapered, curved or flat pattern along the flight trajectory of the emitted electron beam, the trajectory of the electron beam is secured, and the spacer coastline distance is increased.In other words, the creepage pressure resistance is increased, thereby making the spacer resistant to atmospheric pressure. Because the electron beam is irradiated with

(1) There is no loss in the amount of current reaching the phosphor target,
Stable light emission without deterioration of luminous efficiency can be obtained.

(2) There is no creeping discharge caused by a drop in creeping voltage due to charge-up of the atmospheric pressure resistant spacer, and an image forming apparatus without element destruction can be obtained.

(3) Since the acceleration voltage can be increased by increasing the creepage breakdown voltage, a light emitting section with higher efficiency and brightness can be obtained.

[Brief explanation of drawings]

FIG. 1 is a perspective view illustrating a first embodiment of the present invention, FIG. 2 is a sectional view of the first embodiment of the present invention, and FIG. 3 is a perspective view illustrating a second embodiment of the present invention. FIG. 4 is a sectional view of the second embodiment of the present invention, and FIG. 5 is an explanatory diagram of a conventional example. 1.2: Electrode 3: Thin film 4: Substrate 5: Electron emitting section 6: Fine particles 7: Phosphor target 8: Light emitting section 9: Drive power source 1O: Acceleration power source 11: Atmospheric pressure resistant spacer

Claims (1)

[Claims] (1) An image forming apparatus using a surface conduction electron-emitting device, characterized in that an atmospheric pressure resistant spacer is provided along the trajectory of electrons emitted from the device.