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:
Sep. 25, 1984
Filed:
Aug. 12, 1982
Thomas C Mackereth, Cambridge, GB;
U.S. Philips Corp., New York, NY (US);
Abstract
A video signal clamping circuit comprises a summing circuit (R1, R2, R9, 2) an analogue to digital converter (3), a programmable read only memory (6), a latch (7), a digital to analogue converter (9) and an integrator (11). The PROM (6) is addressed by the ADC(3) and produces a 4 bit output code which is dependent on the amplitude of the video signal. This is stored on the latch (7) and passed to the DAC(9) during a timing pulse applied to terminal (8) which occurs during the line blanking period. The DAC(9) produces an output which is stored on the capacitor (C1) in the integrator (11). The integrator (11) output is summed with the input video signal to clamp the video signal level to the reference voltage so that a clamped digital video signal is available from the output (5).