Method of making a viewing screen structure for a cathode-ray tube

• US 4,729,907 A
• Filed: 02/24/1987
• Issued: 03/08/1988
• Est. Priority Date: 02/24/1987
• Status: Expired due to Term

• Current Assignee: RCA Corporation (General Electric Company)
• Original Assignee: RCA Corporation (General Electric Company)
• Inventors: Lambert, Richard A., Deal, Samuel B.
• Primary Examiner(s): Bell, Janyce A.
• Application Number:
  US07/017,726
• Time in Patent Office: 378 Days
• Field of Search: 427/64, 427/236, 427/314, 427/407.2, 427/424, 427/427, 427/421, 427/68
• US Class Current: 427/64
• CPC Class Codes: H01J 29/28 with protective, conductive or reflective layers

Abstract

An aluminized viewing screen structure for a cathode-ray tube includes a faceplate panel having a barrier coating and a heat absorptive overcoating comprising a plurality of layers overlying the aluminum metal layer. The barrier coating and the overcoating are applied to the panel which is preheated to accelerate drying of the barrier coating and the overcoating. The novel process includes (a) tilting the preheated panel to a 60°±10° angle relative to a horizontal plane, (b) loading the tilted panel onto a carrier, (c) and advancing the carrier by means of a conveyor in a first direction, through a spray assembly. A plurality of spray guns are mounted on a reciprocating device which moves up and down, that is, in a second and a third direction which is different from the direction of motion of the conveyor. The spray guns are directed substantially perpendicular to the faceplate panel. One of the spray guns is activated and deactivated to deposit a barrier coating of a volatilizable film-forming material on the aluminum metal layer. The remaining guns are sequentially activated and deactivated to deposit on the barrier-coated metal layer a heat absorptive overcoating comprising a plurality of layer. The conveyor can be reversed after the carrier and panel exit the spraying assembly and the carrier and panel can be transported through the spray assembly in a fourth direction which is opposite to the first direction. During the reverse transit of the carrier and the panel through the spray assembly, the spray guns are once again activated and deactivated to provide additional plural layers of the heat absorptive overcoating.

Claims

1. In a method of making a viewing screen structure for a cathode-ray tube having a faceplate panel, a viewing screen on a portion thereof and a metal layer on said viewing screen, the steps subsequent to producing said metal layer comprising

(A) preheating said panel in a preheat oven,

(B) conveying said heated panel to a tilt station by means of a transport device.

(C) tilting said panel to a 60°

±

10°

angle relative to a horizontal plane.

(D) loading said tilted panel onto a carrier.

(E) advancing said carrier and said guns being perpendicular to said panel by means of said transport device in a first direction through a spray assembly including a spray booth and a plurality of spray guns mounted on a reciprocating device which is parallel to said carrier, said reciprocating device moving said spray guns in a second and a third direction, said second and third direction being different from said first direction,

(F) activating and deactivating one of said spray guns to deposit on said metal layer a barrier coating of a volatilizable film-forming material.

(G) and sequentially activating and deactivating the remaining spray guns to deposit on the barrier-coated metal layer multiple coatings of a heat absorptive overcoating.

2. The method as described in claim 1 including the additional steps, after step (G) of

(i) reversing said transport device to move said carrier through said spray assembly in a fourth direction opposite to said first direction,

(ii) sequentially activating and deactivating said remaining spray guns to deposit, on said heat absorptive overcoating an additional plurality of coatings of heat absorptive material,

(iii) exiting said spray assembly,

(iv) and then, unloading said panel from said carrier.

3. In a method of making a viewing screen structure for a cathode-ray tube having a faceplate panel, a viewing screen on a portion thereof and a metal layer on said viewing screen, the steps subsequent to producing said metal layer comprising

(a) preheating said panel in a preheat oven,

(b) conveying said heated panel to a tilt station by means of a transport device.

(c) tilting said panel to a 60°

±

10°

angle relative to a horizontal plane,

(d) loading said tilted panel onto a carrier,

(e) advancing said carrier by means of said transport device in a first direction through a spray assembly including a spray booth and a plurality of spray guns mounted on a reciprocating device which is parallel to said carrier, said guns being substantially perpendicular to said panel, said reciprocating device moving said spray guns in a second direction different from said first direction.

(f) activating and deactivating one of said spray guns to deposit on said metal layer a barrier coating of a volatilizable film forming material,

(g) and sequentially activating and deactivating the remaining spray guns to deposit on the barrier-coated metal layer multiple coatings of a heat absorptive overcoating comprising a plurality of layers

(h) exiting said spray assembly with said carrier and reversing said transport device to move said carrier in a third direction, opposite said first direction through said spray booth,

(i) sequentially activating and deactivating said remaining spray guns to deposit, on said heat absorptive overcoating an additional plurality of coatings of heat absorptive material,

(j) exiting said spray assembly,

(k) and then, unloading said panel from said carrier.

4. A method of making a viewing screen structure for a cathode-ray tube having a faceplate panel, a viewing screen on a portion thereof and a metal layer on said viewing screen, the steps subsequent to producing said metal layer comprising

(A) loading said panel onto a spray shield.

(B) placing said spray shield and said panel onto a transport device moving in a horizontal plane.

(C) conveying said spray shield with said panel thereon into a preheated oven.

(D) transporting said heated spray shield and said panel to a tilt station.

(E) tilting said heated spray shield and said panel to a 60°

±

10°

angle relative to said horizontal plane.

(F) loading said tilted spray shield and said panel onto a carrier.

(G) advancing said carrier in a first direction into a spray assembly including a spray booth and a plurality of spray guns mounted on a reciprocating device which is parallel to said carrier, said reciprocating device moving said spray guns in a second direction and an opposed third direction, said second and third directions being different from said first direction, said spray guns being substantially perpendicular to said panel.

(H) activating and deactivating one of said spray guns to deposit on said metal layer a barrier coating of a volatilizable film-forming material.

(I) and sequentially activating and deactivating the remaining spray guns to deposit on a barrier-coated metal layer multiple coatings of a heat absorptive overcoating.

5. The method as described in claim 4, including the additional steps, after step (I) of

(i) reversing said transport device to move said carrier through said spray assembly in a fourth direction, said fourth direction being opposite said first direction.

(ii) sequentially activating and deactivating said remaining spray guns which deposit on said heat absorptive overcoating an additional plurality of coatings of heat absorptive material,

(iii) exiting said spray assembly,

(iv) and then, unloading said spray shield and said panel from said carrier.