This recent Canon US reissue patent is of interest in that it pertains to SED type subject matter but includes the possibility that a carbon layer on the cathode is not an absolute necessity (though it is mentioned as a possibility) and can consist solely of SnO2 (tin oxide):
United States Patent RE40,062
Yoshioka , et al. February 12, 2008
Display device with electron-emitting device with electron-emitting region insulated from electrodes
Abstract
A display device includes an electron-emitting device which is a laminate of an insulating layer and a pair of opposing electrodes formed on a planar substrate. A portion of the insulating layer is between the electrodes and contains fine particles of an electron emitting substance, that portion acting as an electron emitting region. Electrons are emitted from the electron emission region by applying a voltage to the electrodes, thereby stimulating a phosphorous to emit light.
Inventors: Yoshioka; Seishiro (Hiratsuka, JP), Nomura; Ichiro (Atsugi, JP), Suzuki; Hidetoshi (Yokohama, JP), Takeda; Toshihiko (Yokohama, JP), Kaneko; Tetsuya (Yokohama, JP), Banno; Yoshikazu (Machida, JP), Yokono; Kojiro (Yokohama, JP)
Assignee: Canon Kabushiki Kaisha (Tokyo, JP)
Appl. No.: 09/587,249
Filed: June 2, 2000
Related U.S. Patent Documents
Application Number - Filing Date - Patent Number - Issue Date
08396066 Feb., 1995
08191065 Feb., 1994
07705720 May., 1991
07218203 Jul., 1988 5066883
Reissue of: 08479000 Jun., 1995 05759080 Jun., 1998
Foreign Application Priority Data
Jul 15, 1987 [JP] 62-174837
Oct 02, 1987 [JP] 62-250448
Oct 09, 1987 [JP] 62-255063
Oct 09, 1987 [JP] 62-255068
Apr 27, 1988 [JP] 63-102485
Apr 27, 1988 [JP] 63-102486
Apr 27, 1988 [JP] 63-102487
Apr 27, 1988 [JP] 63-102488
Jun 21, 1988 [JP] 63-154516 [A very early date!!]
http://tinyurl.com/38p9b3
Canon is up to something - I'm not sure what. This requires some analysis to see if their SED development can be based on this patent and bypass our IP.
These clams get my attention as noted by --[]-- my comments in the brackets:
.Iadd.6. A method of fabricating an electron-emitting device which comprises a pair of electrodes and a layer disposed between the electrodes, the method comprising the steps of: disposing the pair of electrodes in first and second regions on a substrate, respectively; and providing the layer between the regions, the layer comprising a metal and a semiconductor, and being in contact with the electrodes so that current flows from one of the electrodes to another one of the electrodes through the layer by a voltage applied between the electrodes, wherein the metal is Pd..Iaddend.[No carbon required - no fine particles required]
.Iadd.7. The method of claim 6, wherein the semiconductor is selected from the group consisting of carbon and SnO.sub.2..Iaddend.[Carbon OR SnO.sub.2]
.Iadd.8. A method of fabricating an electron-emitting device, comprising the steps of: disposing a pair of electrodes in first and second regions on a substrate, respectively; and providing a layer between the regions, the layer comprising carbon and a metal, and being in contact with the electrodes so that current flows from one of the electrodes to another one of the electrodes through the layer by a voltage applied between the electrodes, wherein the metal is Pd..Iaddend.[No carbon required - no fine particles required]
.Iadd.9. A method of fabricating an electron-emitting device, comprising the steps of: disposing a pair of electrodes in first and second regions on a substrate, respectively; and providing a layer between the regions, the layer comprising carbon and a metal, and being in contact with the electrodes so that current flows from one of the electrodes to another one of the electrodes through the layer by a voltage applied between the electrodes, wherein the layer comprises primarily carbon..Iaddend.[Carbon is required]
.Iadd.10. A method of fabricating an electron-emitting device, comprising the steps of: disposing a pair of electrodes in first and second regions on a substrate, respectively; and providing a layer between the regions, the layer being in contact with the electrodes so that current flows from one of the electrodes to another one of the electrodes through the layer by a voltage applied between the electrodes, the layer comprising an insulating material and at least some conductive particles which protrude from a surface of the layer, wherein the conductive particles comprise Pd..Iaddend.[No carbon required - conductive particles are required]
.Iadd.11. The method of claim 10, wherein the insulating material is SiO.sub.2..Iaddend.[No carbon required]
Don't know if this is the way to avoid carbon. Carbon is certainly contemplated! But NOT a requirement!! Is carbon the BEST? Unknown - but likely so. Does NPI's IP cover a non-carbon variation anyway? I think so!
BTW - what is added in the reissue appears between '.Iadd.' and '.Iaddend.'
The original US patent 5,759,080 is here:
Link
These are the claims:
1. A method of preparing an electron-emitting device, comprising the steps of:
forming electrodes opposed to each other on a substrate;
forming between the electrodes and in contact therewith an insulating layer in which fine particles are completely enclosed; and
etching the insulating layer so as to partially expose the fine particles.
2. A method of preparing an electron-emitting device comprising the steps of:
forming electrodes opposed to each other on a substrate;
forming between the electrodes and in contact therewith a semiconductor layer in which fine particles are completely enclosed; and
etching the semiconductor layer so as to partially expose the fine particles.
3. A method of preparing an electron-emitting device, comprising the steps of:
(i) forming a semiconductor layer on a substrate;
(ii) forming electrodes on said semiconductor layer; and
(iii) dispersing fine particles between said electrodes.
4. The method of claim 3, wherein said semiconductor layer comprises a layer comprising an amorphous silicon semiconductor, a crystallized silicon semiconductor, or a compound semiconductor.
5. The method of claim 3, wherein said semiconductor layer has a film thickness of from 50 angstroms to 10 .mu.m.
All original claims require the presence of 'fine particles'. The Reissue claims 6-48 do NOT so require these 'fine particles' in every claim!!
Claims 1-5 inclusive are original while claims 6-48 are added in the reissue patent.
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