Electric lamp and discharge devices: systems – Cathode ray tube circuits – Pulse storing
Patent
1996-05-22
1998-04-21
Pascal, Robert
Electric lamp and discharge devices: systems
Cathode ray tube circuits
Pulse storing
315 85, 313479, 361150, 361152, H04N 929
Patent
active
057421285
ABSTRACT:
Apparatus for mitigating the adverse effects of magnetic interference on the operation of a CRT is provided. More specifically, magnetic sensors are placed in a gap formed between a front bezel and a rear enclosure comprising a magnetic shield enclosing all but the viewing surface of a CRT. The gap serves to concentrate the on-axis magnetic field and the resultant signal from the sensors is amplified to drive current through a compensation coil located inside the front bezel and in front of the viewing surface of the CRT. The current generates a compensation field that mitigates the incoming on-axis magnetic field. The ambient magnetic field is also sensed by a three axis magnetic sensing assemblage located outside the magnetic shield. The output of the sensing arrangement is operated on to produce a trigger to start a degauss cycle. A resonant degauss circuit, including a degauss coil also disposed around the inside of the front bezel and in front of the viewing surface of the CRT, is driven by a balanced bridge rail switch which repeatedly reverses the polarity of the voltage across the resonant circuit. This produces a high voltage squarewave that serves to drive current through the degauss coil. This generates a degauss field which degausses the CRT.
REFERENCES:
patent: 4000432 (1976-12-01), Coon et al.
patent: 4380716 (1983-04-01), Romeo et al.
patent: 4384313 (1983-05-01), Steingroever et al.
patent: 4560900 (1985-12-01), Ikegaki et al.
patent: 4636911 (1987-01-01), Truskalo
patent: 4783715 (1988-11-01), Liepe
patent: 4963789 (1990-10-01), Buhler
patent: 4996461 (1991-02-01), Bentley
patent: 5017832 (1991-05-01), Takita
patent: 5066891 (1991-11-01), Harrold et al.
patent: 5216326 (1993-06-01), Lundgren
patent: 5243262 (1993-09-01), Moen
patent: 5260626 (1993-11-01), Takase et al.
patent: 5367221 (1994-11-01), Santy et al.
patent: 5379117 (1995-01-01), Yang
patent: 5404084 (1995-04-01), Onodera et al.
patent: 5499156 (1996-03-01), Bentley
Bearce Winfield Scott
Druchunas John
Haywood Christopher N.
Kinkead Arnold
Orwin Associates, Inc.
Pascal Robert
Trainor James J.
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