Low-noise, high dynamic-range image sensor
AssigneeRambus Inc.
InventorsMichael Guidash, Thomas Vogelsang, Jay Endsley, James E. Harris, Craig M. Smith, John Ladd, Michael T. Ching
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Abstract
An integrated-circuit image sensor generates, as constituent reference voltages of a first voltage ramp, a first sequence of linearly related reference voltages followed by a second sequence of exponentially related reference voltages. The integrated-circuit image sensor compares the constituent reference voltages of the first voltage ramp with a first signal level representative of photocharge integrated within a pixel of the image sensor to identify a first reference voltage of the constituent reference voltages that is exceeded by the first signal level.
Claims24
A method of operation within an integrated circuit image sensor, the method comprising:
- generating, as constituent reference voltages of a first voltage ramp, a first sequence of linearly related reference voltages followed by a second sequence of exponentially related reference voltages;
- and
- comparing the constituent reference voltages of the first voltage ramp with a first signal level representative of photocharge integrated within a pixel to identify a first reference voltage of the constituent reference voltages that is exceeded by the first signal level.
An integrated-circuit image sensor comprising:
- a pixel to integrate photocharge during an image frame interval;
- a control voltage generator to generate, as constituent reference voltages of a first voltage ramp, a first sequence of linearly related reference voltages followed by a second sequence of exponentially related reference voltages;
- and
- readout circuitry to compare the constituent reference voltages of the first voltage ramp with a first signal level representative of the photocharge integrated within the pixel to identify a first reference voltage of the constituent reference voltages that is exceeded by the first signal level.
An integrated-circuit image sensor comprising:
- a pixel to integrate photocharge during an image frame interval;
- means for generating, as constituent reference voltages of a first voltage ramp, a first sequence of linearly related reference voltages followed by a second sequence of exponentially related reference voltages;
- and
- means for comparing the constituent reference voltages of the first voltage ramp with a first signal level representative of the photocharge integrated within the pixel to identify a first reference voltage of the constituent reference voltages that is exceeded by the first signal level.
Dependencies are inferred from the claim text.