Electric lamp and discharge devices: systems – Cathode ray tube circuits – Cathode-ray deflections circuits
Patent
1990-04-30
1992-02-18
Blum, Theodore M.
Electric lamp and discharge devices: systems
Cathode ray tube circuits
Cathode-ray deflections circuits
315381, 358220, H01J 2952
Patent
active
050897543
ABSTRACT:
A circuit for protecting a cathode ray tube screen from damage by an electron beam includes a semiconductor switch device having an input coupled to a signal related to a deflection signal for the electron beam. The switch device is coupled to a voltage supply and the circuit further includes a charge storage device coupled to the switch device and further coupled to a control grid of the cathode ray tube. The charge storage device is charged through the switch device by the voltage supply when the deflection signal is present at a control input of the switch device. The switch device decouples the supply voltage from the charge storage device when the deflection signal is not present and places a negative blanking voltage developed on the charge storage device across the control grid when the deflection signal is not present to cut-off beam current in the cathode ray tube.
REFERENCES:
patent: 3810024 (1974-05-01), Meacham
patent: 3963961 (1976-06-01), Ray et al.
patent: 4056758 (1977-11-01), Schaas
patent: 4198661 (1980-04-01), Gatten et al.
patent: 4297619 (1981-10-01), Kiteley
patent: 4340910 (1982-07-01), Valdes
patent: 4390817 (1983-06-01), Johnson
patent: 4404500 (1983-09-01), Stow
patent: 4488181 (1984-12-01), Haferl
patent: 4521720 (1985-06-01), Griffey
patent: 4642532 (1987-02-01), Hoover
patent: 4660093 (1987-04-01), Craig
patent: 4677351 (1987-06-01), Brust et al.
patent: 4763046 (1988-08-01), Sheikholeslami et al.
Pp. 1 and 2 of Schematic Diagram entitled, Rear Projection CRT Board, dated Mar. 25, 1988 and Jan. 12, 1989.
U.S. Pat. Appl. RCA 86,030 entitled, A Self Biasing Protection Arrangement for a Cathode Ray Tube, in the name of John Barrett George.
U.S. Pat. Appl. RCA 86,033 entitled A Deflection Loss Protection Arrangement for a CRT, in the names of Leroy Samuel Wignot and Lawrence Edward Smith.
Schematic Diagram for PV-140/Digital (G) Zenith Rear Proj. Color Digital TV Receiver, Reprinted in Profax, May 1990.
U.S. Pat. Appl. RCA 86,041 entitled, Projection TV Deflection Loss Protection Circuit, in the names of Marvin Neil Norman, Lawrence Edward Smith & Peter Ronald Knight.
U.S. Pat. Appl. RCA 85,651 entitled Video Display Apparatus with Kinescope Spot Burn Protection Circuit, in the names of Thomas David Gurley and Leroy Samuel Wignot.
Blum Theodore M.
Henig Sammy S.
Laks Joseph J.
Thomson Consumer Electronics Inc.
Tripoli Joseph S.
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