Conditional-reset, multi-bit read-out image sensor
AssigneeRambus Inc.
InventorsThomas Vogelsang, MIchael Guidash, Song Xue, James E. Harris
Life of this patent
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Abstract
An image sensor architecture with multi-bit sampling is implemented within an image sensor system. A pixel signal produced in response to light incident upon a photosensitive element is converted to a multiple-bit digital value representative of the pixel signal. If the pixel signal exceeds a sampling threshold, the photosensitive element is reset. During an image capture period, digital values associated with pixel signals that exceed a sampling threshold are accumulated into image data.
Claims21
1-23. (canceled)
An integrated-circuit image sensor comprising:
- a photosensitive element to accumulate charge in response to incident light;
- and
- a read-out circuit to:
- determine whether the charge accumulated within the photosensitive element exceeds a first threshold;
- convert an analog readout signal representative of the charge accumulated into a multi-bit digital value having a numeric value according to a magnitude of the analog readout signal if the charge accumulated is determined to exceed the first threshold;
- reset the photosensitive element to a nominal discharged state in preparation for further charge accumulation if the charge accumulated is determined to exceed the first threshold;
- and
- refrain from resetting the photosensitive element to the nominal discharged state if the charge accumulated is determined not to exceed the first threshold.
A method of operation within an integrated-circuit image sensor, the method comprising:
- accumulating charge within a photosensitive element in response to incident light;
- and
- determining whether the charge accumulated within the photosensitive element exceeds a first threshold;
- converting an analog readout signal representative of the charge accumulated into a multi-bit digital value having a numeric value in proportion to a magnitude of the analog readout signal if the charge accumulated is determined to exceed the first threshold;
- resetting the photosensitive element to a nominal discharged state in preparation for further charge accumulation if the charge accumulated is determined to exceed the first threshold;
- and
- refraining from resetting the photosensitive element to the nominal discharged state if the charge accumulated is determined not to exceed the first threshold.
An integrated-circuit image sensor comprising:
- a photosensitive element to accumulate charge in response to incident light;
- and
- means for:
- determining whether the charge accumulated within the photosensitive element exceeds a first threshold;
- converting an analog readout signal representative of the charge accumulated into a multi-bit digital value having a numeric value in proportion to a magnitude of the analog readout signal if the charge accumulated is determined to exceed the first threshold;
- resetting the photosensitive element to a nominal discharged state in preparation for further charge accumulation if the charge accumulated is determined to exceed the first threshold;
- and
- refraining from resetting the photosensitive element to the nominal discharged state if the charge accumulated is determined not to exceed the first threshold.
Dependencies are inferred from the claim text.