Screen contact means for a cathode ray tube

• US 4,344,015 A
• Filed: 08/18/1980
• Issued: 08/10/1982
• Est. Priority Date: 08/18/1980
• Status: Expired due to Term

• Current Assignee: Burle Technologies, Inc.
• Original Assignee: RCA Corporation
• Inventors: Marschka, Frank D.
• Primary Examiner(s): Demeo, Palmer C.
• Application Number:
  US06/179,154
• Time in Patent Office: 722 Days
• Field of Search: 313/479, 313/477 HC, 313/466, 313/477 R, 313/461
• US Class Current: 313/466
• CPC Class Codes: H01J 29/28 with protective, conductive or reflective layers
• CPC Class Codes: H01J 29/92 Means forming part of the tube for the purpose of providing electrical connection to it

Abstract

A cathode ray tube comprises an envelope having a funnel portion with an electrical terminal extending through a wall surface thereof. A faceplate is sealed to the funnel portion and a screen contact assembly provides electrical contact between the electrical terminal and an aluminum coating on an inside surface of the faceplate. The screen contact assembly includes a conductive strip attached at one end to the electrical terminal. At the other end of the strip and attached thereto is a relatively flexible first contact member which is in pressured electrical contact with the aluminum layer on the faceplate. Disposed between the flexible first contact member and the aluminum layer on the faceplate is an oxidized, silver plated NICHROME foil member of high electrical conductivity. Transverse support and lateral stability is provided by a relatively flexible second contact member attached to and forming a part of the screen contact assembly.

Claims

1. A cathode ray tube including an envelope comprising a funnel portion and a faceplate sealed together with a frit seal,

an electron gun within a neck portion of said funnel,

an electrical terminal extending through said funnel adjacent to said seal,

a conductive coating on the interior surface of said funnel,

a phosphor screen layer on a first portion only of said faceplate,

an aluminum conductive layer on said phosphor screen layer and on at least a portion of the remaining area of said faceplate not covered by said phosphor screen, that portion of said aluminum layer on said remaining faceplate portion constituting a contact area for said phosphor screen,

a screen contact assembly comprising:

(a) a relatively stiff conductive strip member attached at a proximal end thereof to said terminal with a distal end thereof being disposed adjacent to said contact area of said aluminum layer,

(b) a first relatively flexible contact member attached at a proximal end thereof to said distal end of said strip member, and

(c) a second relatively flexible contact member comprising an elongated element disposed orthogonally to and attached at its midpoint to said strip member, said second contact member having two distal ends which are in spring pressure contact with said conductive coating on said funnel; and

a foil member attached to said screen contact assembly and pressed against said contact area of said aluminum layer by spring pressure of said first flexible contact member.

2. The tube as in claim 1 wherein said first contact member includes a pair of embossed, upturned and inwardly directed contact surfaces formed in a bifurcated distal end of said first member.

3. The tube as in claim 1 wherein said second contact member includes a pair of embossed, upturned and inwardly directed contact surfaces formed in a pair of bifurcated distal ends.

4. The tube as in claim 1 wherein the foil member comprises NICHROME having an oxidized silver plated layer thereon.

5. A cathode ray tube comprising an envelope having an electron gun sealed to one end of a funnel portion, said funnel portion having a seal land at the opposite end thereof;

an electrical terminal extending through said funnel portion adjacent to said seal land and spaced therefrom;

a conductive coating disposed on an interior surface of said funnel portion, said coating extending from said electron gun to said seal land;

a faceplate sealed to said funnel portion by a frit seal;

a phosphor screen layer disposed on a first portion only of an interior surface of said faceplate;

a layer of aluminum disposed on said phosphor screen layer and on at least a portion of the remaining area of said faceplate not covered by said phosphor screen, that portion of said aluminum layer on said remaining faceplate portion constituting a contact area for said phosphor screen;

a screen contact assembly bridging said frit seal, said screen contact assembly extending from said electrical terminal to said layer of aluminum deposited on said contact area, said screen contact assembly comprising a relatively stiff longitudinal conductive strip member attached at a proximal end thereof to said electrical terminal, a relatively flexible first contact member attached to a proximal end thereof to a distal end of said strip member, said first contact member having a bifurcated distal end forming a pair of embossed, upturned contact surfaces to effect spring pressured electrical connection with said layer of aluminum on said contact areas of said faceplate, said screen contact assembly further including an elongated, relatively flexible second contact member disposed orthogonally to and fixedly attached at the midpoint thereof to said strip member to provide lateral stability to said strip member, said second contact member having two distal ends which are in spring pressure electrical contact with said conductive coating on said interior surface of said funnel assembly; and

a NICHROME foil member having an oxidized silver layer thereon, said foil member being disposed between said layer of aluminum and said pair of contact surfaces formed in the bifurcated distal end of said first contact member to improve the electrical connection therebetween, said foil member being attached to said screen contact assembly.