Electric lamp and discharge devices – With luminescent solid or liquid material – Vacuum-type tube
Reexamination Certificate
2000-11-28
2003-03-18
Patel, Vip (Department: 2879)
Electric lamp and discharge devices
With luminescent solid or liquid material
Vacuum-type tube
C313S292000
Reexamination Certificate
active
06534911
ABSTRACT:
TECHNICAL FIELD
The present invention relates to an electron beam device, and an image forming apparatus, such as a display device which is an application of the electron beam device.
BACKGROUND ART
Up to now, as the electron-emitting devices, there have been known a hot cathode element and a cold cathode element. As the cold cathode element of those elements, there have been known, for example, a surface conduction type electron-emitting device, a field emission element (hereinafter referred as “FE type”), a metal/insulating layer/metal type emission element (hereinafter referred to as “MIM type”), etc.
As the surface conduction type electron-emitting devices, there have been known, for example, an example disclosed in Radio Eng. Electron Phys., 10, 1290 (1965) by M. I. Elinson, or other examples which will be described later.
The surface conduction type emission element utilizes a phenomenon in which electron emission occurs by allowing a current to flow into a small-area thin film formed on a substrate in parallel to a film surface. As the surface conduction type emission element, there have been reported a surface conduction type emission element using an SnO
2
thin film by such as the above-mentioned Elinson, a surface conduction type emission element using an Au thin film [G. Dittmer: “Thin Solid Films”, 9,317 (1972)], a surface conduction type emission element using an In
2
O
3
/SnO
2
thin film [M. Hartwell an C. G. Fonstad: “IEEE Trans. ED Conf.”, 519(1975)], a surface conduction type electron-emitting device using a carbon thin film [“Vapor Vacuum,” Vol. 26, No. 1, p 22 (1983), by Hisashi Araki, et al.], etc.
As a typical example of those surface conduction type emission elements, a plan view of the above-mentioned element structure by M. Hartwell and others is shown in FIG.
29
. In
FIG. 29
, reference numeral
3001
denotes a substrate, and reference numeral
3004
denotes an electrically conductive film that is made of a metal oxide formed through sputtering. The electrically conductive film
3004
is formed in an H-shaped plane as shown. An electrifying process called “electrification forming” which will be described later is conducted on the electrically conductive thin film
3004
to form an electron emission portion
3005
. In
FIG. 29
, an interval L is set to 0.5 to 1 [mm], and W is set to 0.1 [mm]. For convenience of showing in the figure, the electron emission portion
3005
is shaped in a rectangle in the center of the electrically conductive thin film
3004
. However, this shape is schematic and does not faithfully express the position and the configuration of the actual electron emission portion.
In the above-mentioned surface conduction type emission elements including the element proposed by M. Hartwell, et al., the electron emission portion
3005
is generally formed on the electrically conductive film
3004
through the electrifying process which is called “electrification forming” before the electron emission is conducted. In other words, the electrification forming is directed to a process in which a constant d.c. voltage or a d.c. voltage that steps up at a very slow rate for example about 1 V/min is applied to both ends of the electrically conducive film
3004
so that the electrically conductive film
3004
is electrified, to thereby locally destroy, deform or affect the electrically conductive film
3004
, thus forming the electron emission portion
3005
which is in an electrically high resistant state. A crack occurs in a part of the electrically conductive film
3004
which has been locally destroyed, deformed or affected. In the case where an appropriate voltage is applied to the electrically conductive thin film
3004
after the above electrification forming, electrons are emitted from a portion close to the crack.
Examples of the FE type have been known from “Field Emission” of Advance in Electron Physics, 8, 89 (1956) by W. P. Dyke and W. W. Dolan, “Physical Properties of Thin-Film Field Emission Cathodes with Molybdenum cones” of J. Appl. Phys., 47,5248 (1976), by C. A. Spindt, etc.
As a typical example of the element structure of the FE element,
FIG. 30
shows a cross-sectional view of the elements made by the above-mentioned C. A. Spindt, et al. In this figure, reference numeral
3010
denotes a substrate,
3011
is an emitter wiring made of an electrically conductive material,
3012
is an emitter cone,
3013
is an insulating layer, and
3014
is a gate electrode. The element of this type is so designed as to apply an appropriate voltage between the emitter cone
3012
and the gate electrode
3014
to produce electric field emission from a tip portion of the emitter cone
3012
.
Also, as another element structure of the FE type, there is an example in which an emitter and a gate electrode are disposed on a substrate substantially in parallel with the substrate plane without using a laminate structure shown in FIG.
30
.
Also, as an example of the MIM type, there has been known, for example, “Operation of Tunnel-Emission Devices,” J. Appl. Phys., 32,646 (1961) by C. A. Mead, etc. A typical example of the element structure of the MIM type is shown in FIG.
31
.
FIG. 31
is a cross-sectional view, and in the figure, reference numeral
3020
denotes a substrate,
3021
is a lower electrode made of metal,
3022
is a thin insulating layer about 100 [Å] in thickness, and
3023
is an upper electrode made of metal about 80 to 300 [Å] in thickness. In the MIM type, an appropriate voltage is applied between the upper electrode
3023
and the lower electrode
3021
, to thereby produce electron emission from the surface of the upper electrode
3023
.
The above-mentioned cold cathode element does not require a heater for heating because it can obtain electron emission at a low temperature as compared with the hot cathode element. Accordingly, the cold cathode element is simpler in structure than the hot cathode element and can prepare a fine element. Also, in the cold cathode element, even if a large number of elements are disposed on the substrate with a high density, a problem such as heat melting of the substrate is difficult to occur. Further, the cold cathode element is advantageous in that a response speed is high which is different from the heat cathode element which is low in the response speed because it operates due to heating by the heater.
For the above-mentioned reasons, a study for applying the cold cathode elements has been extensively conducted.
For example, the surface conduction type emission element has the advantage that a large number of elements can be formed on a large area since it is particularly simple in structure and also easy to manufacture among the cold cathode elements. For that reason, a method in which a large number of elements are arranged and driven has been studied for example, as disclosed in JP-A-64-31332 by the present applicant.
Also, as the application of the surface conduction type emission element, for example, an image display device, an image forming apparatus such as an image recording device, a charge beam source, and so on have been studied. In particular, as the application to the image display device, there has been studied an image display device using the combination of the surface conduction type emission element with a phosphor that emits light by irradiation of an electron beam as disclosed in for example U.S. Pat. No. 5,066,883 by the present applicant, JP-A-2-257551, and JP-A-4-28137. In the image display device using the combination of the surface conduction type electron-emitting device with the phosphor, the characteristic superior to the conventional other image display devices is expected. For example, even as compared with the liquid crystal display device which has been spread in recent years, the above image display device is excellent in that no back light is required because it is of the self light emitting type and the angle of visibility is broad.
Also, a method in which a large number of
LandOfFree
Electron beam device does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Electron beam device, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Electron beam device will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3001998