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US 7,443,435 B2Granted
Column amplifier with automatic gain selection for CMOS image sensors
AssigneeAltaSens, Inc.
InventorMarkus Loose
Life of this patent
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AssigneeAltaSens, Inc.
InventorMarkus Loose
Estimating the term…
A column amplifier architecture having automatic gain selection for CMOS image sensors, which reduces the effect of analog noise, while maintaining a system's dynamic range. A comparator compares an amplified column buffer output signal to a reference voltage. The output of the comparator controls the gain of the amplifier based on the result of the comparison. Initially, a high column buffer gain is selected. For small signals, the output of the column buffer stays below the reference voltage and the output signal stays within the system's dynamic range. For larger signals, the column buffer output will exceed the reference voltage (and also the system's dynamic range) and therefore the comparator output switches states, which selects the low-gain setting. Multiple gain levels may be implemented, if desired.
In a CMOS image sensor having a plurality of pixels, a column buffer having automatic gain control, the column buffer comprising:
A CMOS image sensor having a plurality of pixels arranged in rows and columns, the image sensor comprising:
A digital video camera comprising:
Dependencies are inferred from the claim text.