Electric lamp and discharge devices: systems – Plural power supplies – Plural cathode and/or anode load device
Reexamination Certificate
2000-07-28
2003-11-18
Philogene, Haissa (Department: 2821)
Electric lamp and discharge devices: systems
Plural power supplies
Plural cathode and/or anode load device
C315S169400, C313S309000, C313S336000
Reexamination Certificate
active
06650061
ABSTRACT:
FIELD OF THE INVENTION
The present invention relates to an electron source, and more particularly concerns an electron-source array which is applied to displays, fluorescent display tubes, lamps, electron guns, etc., and which can be driven based on the X-Y matrix, and a manufacturing method thereof as well as a driving method for such an electron-source array.
BACKGROUND OF THE INVENTION
In recent years, it has been expected that field emission displays (FED) can be applied to self-emission type flat panel displays, and studies and developments have been extensively made on electron emitting type electron sources. With respect to the electron source used for FEDs, a pyramid-type metal electron source, disclosed by C. A. Spindt et al. as shown in
FIG. 35
(U.S. Pat. No. 3,665,241), has been well known.
As illustrated in
FIG. 35
, the electron source has a construction in which: a cathode electrode
113
, a gate insulation layer
114
and a gate electrode
115
are successively stacked on a substrate
112
and a conic shape metal emitter (electron source)
116
electrically connected to the cathode electrode
113
is placed into a through hole
114
a
reaching the cathode electrode
13
, formed in the gate insulation layer
114
.
In the above-mentioned electron source, however, although the conic shape metal emitter
116
, which is an electron source, is made of a high-melting-point metal material, there have been serious problems relating to the tip-diameter control, uniformity control and reliability of the electron source (metal emitter
116
).
Moreover, in 1991, a carbon nanotube was discovered by Iijima, et al. (Nature, 354, 56, 1991). This carbon nanotube has an arrangement in which a graphite layer, rolled into a cylinder shape, is allowed to have a nest shape, and its tip diameter is approximately 10 nm; thus, since this is superior in oxidation resistant property and ion-impact resistant property, this is considered to form a material having superior properties for use as the electron source.
In fact, in 1995, research groups of R. E. Smalley et al. (Science, 269, 1550, 1995) and W. A. de Heer et al. (Science, 270, 1179, 1995) reported electric field discharging experiments from carbon nanotubes. In the electric field discharging experiments of this type, a carbon nanotube is placed on a metal electrode as a cast film and a metal plate mesh is used as a lead-out electrode so that electrons are collected onto an anode that is an opposing electrode.
With respect to an electron source using such a carbon nanotube, for example, Japanese Laid-Open Patent Application No. 162383/1999 (Tokukaihei 11-162383 (published on Jun. 18, 1999)) (hereinafter, referred to as reference
1
) has disclosed a technique in which a carbon nanotube in the form of paste is formed on a substrate by a printing method so as to manufacture a plane display.
As illustrated in
FIG. 36
, in the electron source disclosed in reference
1
, a cathode electrode
113
is formed on a substrate
112
as a metal electrode, an insulation layer
121
having contact holes
120
is formed on the cathode electrode
113
, ribs
122
are formed on the insulation layer
121
in the form of lines in a manner so as to avoid the contact holes
120
, a gate insulation layer
114
is formed on the ribs
112
, and a carbon nanotube film
123
is formed so as to cover areas having the contact holes
120
of the insulation layer
121
as a paste film, with an anode electrode
124
being located so as to oppose the gate insulation layer
114
with a space in between.
Moreover, Japanese Laid-Open Patent Application No. 12124/1998 (Tokukaihei 10-12124 (published on Jan. 16, 1998)) (hereinafter, referred to as reference
2
) discloses an electron source in which, as illustrated in
FIG. 37
, an alumina layer
118
is placed on a substrate
112
made of glass with an aluminum layer
117
interpolated in between, and in which pores reaching the aluminum layer
117
are formed in the alumina layer
118
. Carbon nanotubes
119
, which have grown as metal catalyst starting points, are placed in the respective pores formed in the alumina layer
118
so that the carbon nanotubes
119
to which power is supplied through the aluminum layer
117
are allowed to function as electron sources.
Therefore, conventionally, with respect to the electron source, it has been known that the time-wise stability of the current intensity is improved by allowing the carbon nanotubes to selectively grow in the pores in the metal and regularly arranging the carbon nanotubes.
However, in the conventional electron source using carbon nanotubes as shown in reference
1
, as illustrated in
FIG. 36
, only a paste film is two-dimensionally formed on the cathode electrode
113
that is a metal electrode;
consequently, it is impossible to control a number of electron-emitting points located on the surface of the paste film. For this reason, it is difficult to ensure uniformity between respective pixels that constitute a display.
Moreover, the carbon nanotube film
123
, formed on the cathode electrode
113
that is a metal electrode, is a plane paste film, with the result that it becomes difficult to control the electron emitting points, and electron discharge takes place randomly on the paste film that forms the discharging section, with the result that it becomes very difficult to assemble this film into a device.
Moreover, as illustrated in
FIG. 37
, in reference
2
, the division of the electron source is achieved by allowing the carbon nanotubes to selectively grow in the pores in the metal; however, in order to separate the electron source, the anodic oxidation film and metal forming a pre-oxide have to be removed up to the supporting substrate, resulting in a difficulty in carrying out X-Y matrix driving required for a display.
Moreover, since the temperature of this process also reaches 1000° C., this process cannot be applied if there is metal remaining as an unoxidized portion, in particular, if there is low-melting-point metal, such as aluminum, remaining as such.
SUMMARY OF THE INVENTION
The objective of the present invention is to provide an electron-source array which enables X-Y matrix driving that is indispensable for achieving a display and also has a construction that is suitable for practical use in terms of processes, and a manufacturing method for such an electron-source array.
In order to achieve the above-mentioned objective, the electron-source array of the present invention, which is provided with cathode electrodes placed on an insulation substrate in the form of lines and gate electrodes that are placed face to face with the cathode electrodes with the insulation film being interpolated in between, is characterized in that the cathode electrodes and the gate electrodes are arranged so as to orthogonally intersect each other with a pore being formed at an intersecting portion between each cathode electrode and each gate electrode in a manner so as to penetrate the insulation film, and in that the pore is filled with a conductive material or a semiconductive material with the material being electrically connected to the corresponding cathode electrode, and is formed in a manner so as to separate from the gate electrodes with a space in between.
Thus, since the gate electrode is placed in a manner so as to orthogonally intersect the cathode electrode, it is possible to provide a construction that enables the X-Y matrix driving that is indispensable for achieving a display.
Moreover, in order to achieve the above-mentioned objective, the electron-source array of the present invention, which is provided with cathode electrodes placed on an insulation substrate in the form of lines, and gate electrodes that are placed face to face therewith with the insulation film being interpolated in between, may be arranged so that the gate electrodes are placed in a manner so as to surround each of electron emitting areas that are developed planarly on the cathode electrodes, and so that electron emitting sections, which form a plurality of separated
Ohki Hiroshi
Urayama Masao
Alemu Ephrem
Conlin, Esq. David C.
Edwards & Angell LLP
Philogene Haissa
Roos, Esq. Richard J.
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