Video circuitry for controlling signal gain and reference black level
AssigneeNational Semiconductor Corporation
InventorPeyman Hojabri
Life of this patent
Estimating the term…
Abstract
A multi-channel video signal processing circuit with a bias control and respective video channel gain controls. The bias signal, which corresponds to a nominal video signal brightness level, is shared among the video channels which, in accordance with respective video gain control signals, process incoming component video signals to provide corresponding outgoing component video signals such that each one of the outgoing component video signals has a nominal outgoing video signal brightness level related to the bias signal and a corresponding one of the gain control signals.
Claims20
An apparatus including a multi-channel video signal processing circuit with a bias control and respective video channel gain controls, comprising:
- bias control circuitry responsive to a bias control signal by providing a bias signal corresponding to a nominal video signal brightness level;
- and
- video signal amplification circuitry coupled to said bias control circuitry and responsive to said bias signal, a plurality of gain control signals and a plurality of incoming component video signals by providing a corresponding plurality of outgoing component video signals;
- wherein
- ratios of corresponding ones of said pluralities of outgoing and incoming component video signals have respective values related to corresponding ones of said plurality of gain control signals, and
- each one of said plurality of outgoing component video signals has a nominal outgoing video signal brightness level related to said bias signal and a corresponding one of said plurality of gain control signals.
An apparatus including a multi-channel video signal processing circuit with a bias control and respective video channel gain controls, comprising:
- bias controller means for receiving a bias control signal and in response thereto generating a bias signal corresponding to a nominal video signal brightness level;
- and
- video signal amplifier means for receiving said bias signal, a plurality of gain control signals and a plurality of incoming component video signals and in response thereto generating a corresponding plurality of outgoing component video signals;
- wherein
- ratios of corresponding ones of said pluralities of outgoing and incoming component video signals have respective values related to corresponding ones of said plurality of gain control signals, and
- each one of said plurality of outgoing component video signals has a nominal outgoing video signal brightness level related to said bias signal and a corresponding one of said plurality of gain control signals.
A method for processing a plurality of video signals with a bias control and respective video channel gain controls, comprising:
- receiving a bias control signal and in response thereto generating a bias signal corresponding to a nominal video signal brightness level;
- and
- receiving said bias signal, a plurality of gain control signals and a plurality of incoming component video signals and in response thereto generating a corresponding plurality of outgoing component video signals;
- wherein
- ratios of corresponding ones of said pluralities of outgoing and incoming component video signals have respective values related to corresponding ones of said plurality of gain control signals, and
- each one of said plurality of outgoing component video signals has a nominal outgoing video signal brightness level related to said bias signal and a corresponding one of said plurality of gain control signals.
Dependencies are inferred from the claim text.