GAIN CONTROL CIRCUIT AND METHOD OF CONTROLLING GAIN
First Claim
1. A gain control circuit comprising:
- an automatic gain controller (AGC) configured to control amplitude of an analog image signal that includes a luminance signal, a color signal and a sync signal;
an analog-to-digital converter (ADC) configured to convert the amplitude-controlled analog image signal to a digital image signal;
a saturation field detecting block configured to determine on a per field basis whether the digital image signal is saturated;
a sync detector configured to detect the sync signal in the digital image signal; and
a gain control block configured to provide a gain control signal to the AGC based on an output signal of the saturation field detecting block and an output signal of the sync detector.
1 Assignment
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Accused Products
Abstract
A gain control circuit includes an automatic gain controller (AGC), an analog-to-digital converter (ADC), a saturation field detecting block, a sync detector and a gain control block. The AGC controls amplitude of an analog image signal including a luminance signal, a color signal and a sync signal. The ADC converts the amplitude-controlled analog image signal to a digital image signal. The saturation field detecting block determines on a per field basis whether the digital image signal is saturated. The sync detector is configured to detect the sync signal in the digital image signal. The gain control block provides a gain control signal to the AGC based on an output signal of the saturation field detecting block and an output signal of the sync detector. Therefore, the gain control circuit may prevent saturation of the analog image signal by controlling gain of the analog image signal.
6 Citations
24 Claims
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1. A gain control circuit comprising:
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an automatic gain controller (AGC) configured to control amplitude of an analog image signal that includes a luminance signal, a color signal and a sync signal; an analog-to-digital converter (ADC) configured to convert the amplitude-controlled analog image signal to a digital image signal; a saturation field detecting block configured to determine on a per field basis whether the digital image signal is saturated; a sync detector configured to detect the sync signal in the digital image signal; and a gain control block configured to provide a gain control signal to the AGC based on an output signal of the saturation field detecting block and an output signal of the sync detector. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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11. A method of controlling gain comprising:
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controlling amplitude of an analog image signal that includes a luminance signal, a color signal, and a sync signal; converting the amplitude-controlled analog image signal to a digital image signal; determining on a per field basis whether the digital image signal is saturated; detecting the sync signal in the digital image signal; and providing a gain control signal that controls the amplitude of the analog image signal based on the detected sync signal and the saturated field that is determined. - View Dependent Claims (12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24)
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Specification