The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Nov. 26, 1985
Filed:
Dec. 05, 1983
Gulab Sharma, Salt Lake City, UT (US);
Beehive International, Salt Lake City, UT (US);
Abstract
A cathode ray tube focusing circuit includes a first operational amplifier for receiving a sawtooth wave signal from the vertical deflection circuit of a cathode ray tube video circuit and for producing a parabolic output signal from the sawtooth wave signal. Also included is a second operational amplifier for receiving both the parabolic signal produced by the first operational amplifier and a parabolic wave signal produced by the S-correction capacitor of the horizontal deflection circuit of the cathode ray tube video circuit. The second operational amplifier inverts the parabolic wave signal received from the first operational amplifier and adds this inverted signal to the parabolic wave signal received from the horizontal deflection circuit to produce a parabolic signal envelope. This parabolic signal envelope is inverted, amplified and supplied to the focus electrode of the cathode ray tube to modulate the focus electrode's static voltage.