Computer graphics processing and selective visual display system – Plural physical display element control system – Display elements arranged in matrix
Reexamination Certificate
1997-02-20
2003-09-16
Saras, Steven (Department: 2675)
Computer graphics processing and selective visual display system
Plural physical display element control system
Display elements arranged in matrix
C345S075200, C313S310000
Reexamination Certificate
active
06621475
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an electron generating apparatus constituted by arranging a plurality of surface-conduction emission devices on a substrate, a method of adjusting the characteristics of the electron generating apparatus, a method of manufacturing the electron generating apparatus, and an image forming apparatus using the electron generating apparatus.
2. Related Background Art
Conventionally, two types of devices, namely thermionic and cold cathode devices, are known as electron-emitting devices. Examples of cold cathode devices are surface-conduction emission devices, field emission type emission devices (to be referred to as FE type devices hereinafter), and metal/insulator/metal type emission devices (to be referred to as MIM type devices hereinafter).
Known examples of the FE type devices are described in W. P. Dyke and W. W. Dolan, “Field Emission”, Advance in Electron Physics, 8,89 (1956) and C. A. Spindt, “Physical properties of thin-film field emission cathodes with molybdenum cones”, J. Appl. Phys., 47,5248 (1976).
A known example of the MIM type devices is described in C. A. Mead, “Operation of Tunnel-emission Devices”, J. Appl. Phys., 32,646 (1961).
A known example of the surface-conduction emission devices is described in, e.g., M. I. Elinson, Radio. Eng. Electron Phys., 10 (1965) and other examples to be described later.
The surface-conduction emission device utilizes the phenomenon that electron emission is caused in a small-area thin film, formed on a substrate, by passing a current parallel to the film surface. The surface-conduction emission device includes devices using an Au thin film (G. Dittmer, “Thin Solid Films”, 9,317 (1972)), an In
2
O
3
/SnO
2
thin film (M. Hartwell and C. G. Fonstad, “IEEE Trans. ED Conf.”, 519 (1975)), and a carbon thin film (Hisashi Araki, et al., “Vacuum”, Vol. 26, No. 1, p. 22 (1983)), and the like, in addition to an SnO
2
thin film according to Elinson mentioned above.
FIG. 27
is a plan view of the surface-conduction emitting device according to M. Hartwell et al. as a typical example of the structures of these surface-conduction emission devices. Referring to
FIG. 27
, reference numeral
3001
denotes a substrate; and
3004
, a conductive thin film made of a metal oxide formed by sputtering. This conductive thin film
3004
has an H-shaped pattern, as shown in FIG.
27
. An electron-emitting portion
3005
is formed by performing an electrification process (referred to as an energization forming process to be described later) with respect to the conductive thin film
3004
. Referring to
FIG. 27
, a spacing L is set to 0.5 to 1 [mm], and a width W is set to 0.1 [mm]. The electron-emitting portion
3005
is shown in a rectangular shape at the center of the conductive thin film
3004
for the sake of illustrative convenience, however, this does not exactly show the actual position and shape of the electron-emitting portion.
In the above surface-conduction emission device by M. Hartwell et al., typically the electron-emitting portion
3005
is formed by performing the electrification process called the energization forming process for the conductive thin film
3004
before electron emission. According to the energization forming process, electrification is performed by applying a constant DC voltage which increases at a very slow rate of, e.g., 1 V/min, to both ends of the conductive thin film
3004
, so as to partially destroy or deform the conductive thin film
3004
or change the properties of the conductive thin film
3004
, thereby forming the electron-emitting portion
3005
with an electrically high resistance. Note that the destroyed or deformed part of the conductive thin film
3004
or part where the properties are changed has a fissure. Upon application of an appropriate voltage to the conductive thin film
3004
after the energization forming process, electron emission is performed near the fissure.
The above surface-conduction emission devices are advantageous because, of cold cathode devices, they have a simple structure and can be easily manufactured. For this reason, many devices can be formed on a wide area. As disclosed in Japanese Patent Laid-Open No. 64-31332 filed by the present applicant, a method of arranging and driving a lot of devices has been studied.
Regarding applications of surface-conduction emission devices to, e.g., image forming apparatuses such as an image display apparatus and an image recording apparatus, charged beam sources and the like have been studied.
As an application to image display apparatuses, in particular, as disclosed in U.S. Pat. No. 5,066,883 and Japanese Patent Laid-Open Nos. 2-257551 and 4-28137 filed by the present applicant, an image display apparatus using the combination of a surface-conduction emission device and a phosphor which emits light upon irradiation of an electron beam has been studied. This type of image display apparatus is expected to have more excellent characteristics than other conventional image display apparatuses. For example, in comparison with recent popular liquid crystal display apparatuses, the above display apparatus is superior in that is does not require a backlight since it is of a light emissive type and that it has a wide view angle.
The present inventors have examined cold cathode devices according to various materials, manufacturing methods, and structures, in addition to the above conventional devices. The present inventors have also studied a multi-electron-beam source in which a lot of cold cathode devices are arranged, and an image display apparatus to which this multi-electron-beam source is applied.
The present inventors have also examined a multi-electron-beam source according to an electric wiring method shown in FIG.
28
. More specifically, this multi-electron-beam source is constituted by two-dimensionally arranging a large number of cold cathode devices and wiring these devices in a matrix, as shown in FIG.
28
.
Referring to
FIG. 28
, reference numeral
4001
denotes a cold cathode device;
4002
, a row wiring layer; and
4003
, a column wiring layer. The row wiring layers
4002
and the column wiring layers
4003
actually have limited electrical resistances which are represented as wiring resistances
4004
and
4005
in FIG.
28
. The wiring shown in
FIG. 28
is referred to as simple matrix wiring. For the illustrative convenience, the multi-electron-beam source constituted by a 6×6 matrix is shown in FIG.
28
. However, the scale of the matrix is not limited to this arrangement, as a matter of course. In a multi-electron-beam source for an image display apparatus, a number of devices sufficient to perform desired image display are arranged and wired.
In the multi-electron-beam source in which the surface-conduction emission devices are wired in a simple matrix, appropriate electrical signals are supplied to the row wiring layers
4002
and the column wiring layers
4003
to output desired electron beams. When the surface-conduction emission devices of an arbitrary row of the matrix are to be driven, a selection voltage Vs is applied to the row wiring layer
4002
of the selected row. Simultaneously, a non-selection voltage Vns is applied to the row wiring layers
4002
of unselected rows. In synchronism with this operation, a driving voltage Ve for outputting electron beams is applied to the column wiring layers
4003
. According to this method, a voltage (Ve−Vs) is applied to the surface-conduction emission devices of the selected row, and a voltage (Ve−Vns) is applied to the surface-conduction emission devices of the unselected rows, assuming that a voltage drop caused by the wiring resistances
4004
and
4005
is negligible. When the voltages Ve, Vs, and Vns are set to appropriate levels, electron beams with a desired intensity are output from only the surface-conduction emission devices of the selected row. When different driving voltages Ve are applied to the respective column wiring layers
4003
, electr
Suzuki Hidetoshi
Yamaguchi Eiji
Awad Amr
Canon Kabushiki Kaisha
Fitzpatrick ,Cella, Harper & Scinto
Saras Steven
LandOfFree
Electron generating apparatus, image forming apparatus,... 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 generating apparatus, image forming apparatus,..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Electron generating apparatus, image forming apparatus,... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3093280