EP0444670A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Planar type cold cathode with sharp tip ends and manufacturing method therefor
Assignee: Panasonic Holdings Corp
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Filing: 1991-02-28
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Granted: —
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Expires: 2011-02-28
Abstract
Abstract A planar type cold cathode (1) for generating electron field emission which comprises a planar cold cathode having triangular convex portions (4) and an anode (5) confronting the triangular convex portions wherein each convex portion has a sharp tip end having a radius of curvature of 0.1 µm or less. Also, a manufacturing method therefor is disclosed. In this method, sharp tip ends of the cold cathode are formed by using a normal etching technique.
Inventors
- 👤 Hiroyuki Kado
- 👤 Masanori Watanabe
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-29 18:42
CPC Classifications
H; H01; H01J; H01J3/00; H01J3/02; H01J3/021; H01J3/022; H01J1/00; H01J1/02; H01J1/30; H01J1/304; H01J1/3042; H01J21/00; H01J21/02; H01J21/06; H01J21/10; H01J21/105
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
105 words
A planar type cold cathode for generating electron field emission which includes a planar cold cathode and an anode being formed on an insulation substrate so as to confront each other, said cold cathode having substantially triangular convex portions projected forward said anode, being characterized in that at least one of two tip ends of said each convex portion defined by the principal planes of said cold cathode, respectively, has a radius of curvature of 0.1 µm or less, and that said one tip end of said each convex portion is formed so as to protrude toward said anode than the other tip end thereof.
Claim 2
Dependent Claim
110 words
A manufacturing method for a cold cathode comprising the following steps; a step of forming a resist film on said film of a conductive material, said resist film being comprised of two portions separated from each other and having shapes similar to those of a cold cathode having substantially triangular convex portions and an anode to be formed, respectively; a step of etching said film of a conductive material, by using the isotropic etching technique, the side etching depth thereof becomes at least more than the radius of curvature of the tip end of each triangular convex portion of said resist film; and a step of removing said resist film.
Claim 3
Dependent Claim
49 words
The manufacturing method as claimed in claim 2, in which each triangular convex portion of said cold cathode having formed have two sharp tip ends defined by the principal planes thereof, at least one of two sharp tip ends having a radius of curvature of 0.1 µm or less.
Claim 4
Dependent Claim
29 words
The manufacturing method as claimed in claim 3, in which one of said two sharp tip ends is formed so as to protrude toward said anode than the other.
Claim 5
Dependent Claim
54 words
The manufacturing method as claimed in claim 2, further comprises a step of removing portions of said insulation substrate locating under peripheries of respective triangular convex portions of said cold cathode by using the isotropic etching technique so as to make each tip end thereof overhang from the etched portion of said insulation substrate.
References Cited (Backward Citations)
No citation records indexed.
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