Abstract Television picture "wash-out" is eliminated by means of a signal processing circuit that adapts and enhances the video gray scale of television pictures to compensate for adverse lighting conditions in the viewed area. The circuit approach comprehends processing the video signal in terms of picture area. Each step on the gray scale from black to white is assigned a percentage of the total picture. The circuit comprises a plurality of comparators each working at a different threshold level. Each comparator is followed by an integrator and a feedback circuit that adapts that comparator sense level to the incoming signal. The video signal is processed in a way that always produces certain assigned ratios of black, white, and/or shades of gray.
Inventors
👤 Edwin B. Sirrine
Bibliographic Details
Application Number—
JurisdictionUS
Data Sourcegoogle_patents
Last Synchronized2026-10-26 12:36
CPC Classifications
H; H04; H04N; H04N23/00; H04N23/70; H04N23/76
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
155 words
An adaptive gray scale control circuit for television video signals comprising a multiplicity of signal processors, each signal processor including a comparator having first and second inputs and an output, an amplifier having an input and an output, a capacitor connected between the input and output of said amplifier, and resistance means, the output of said comparator being connected to the input of said amplifier through said resistance means and the output of said amplifier being connected to said second comparator input, means for simultaneously applying a video signal to the first comparator input of each signal processor, means for providing a discrete DC bias to the amplifier input of each signal processor, an output summing amplifier having an input and an output, and a circuit connecting the comparator output of each signal processor to the input of said output summing amplifier, said circuit including means for weighting the value of each comparator output signal.
Claim 2
Dependent Claim
155 words
An adaptive gray scale control circuit for television video signals comprising a multiplicity of signal processors, each signal processor including a comparator having first and second inputs and an output, an amplifier having an input and an output, a capacitor connected between the input and output of said amplifier, and resistance means, the output of said comparator being connected to the input of said amplifier through said resistance means and the output of said amplifier being connected to said second comparator input, means for simultaneously applying a video signal to the first comparator input of each signal processor, means for providing a discrete DC bias to the amplifier input of each signal processor, an output summing amplifier having an input and an output, and a circuit connecting the comparator output of each signal processor to the input of said output summing amplifier, said circuit including means for weighting the value of each comparator output signal.