Compact image capture device
AssigneeEastman Kodak Company
InventorMark Marshall Meyers
Life of this patent
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Abstract
The image capture device incorporates an array of photodetectors, utilizing an integral current mirror formed at each photodetector location to increase photodetector current output. A correlated double sampling circuit is also formed at each photodetector location to sum the current generated by the current mirror over each exposure period, so as to produce a voltage proportional to the radiation intensity incident at each photodetector location. The correlated double sampling circuit is used to reduce noise in the photodetected signal and to eliminate the effect of dark current. Combining the image capture device with a unique lenslet array forms an extremely compact optical array camera. An embodiment with a mechanical shutter is also disclosed.
Claims15
A photosensor array of pixels each of the pixels comprising:
- a current generating photodetector having a photodiode that is operatively coupled in combination with an associated multiplying current mirror located within the pixel and comprised of one input transistor and at least two output transistors where the generated photocurrent from each photodetector is multiplied by an integer equal to the number of output transistors in the associated multiplying current mirror and to provide the multiplied current as an output signal;
- and
- wherein the output signal is selectively switched through a plurality of amplifiers having positive gain during periods where the photosensor is receiving incident light and negative gain during periods where the photosensor is not receiving incident light.
A photosensor array of pixels within each of the pixels comprising:
- a current generating photodetector having a photodiode that is operatively coupled in combination with an associated multiplying current mirror located within the pixel and comprised of one input transistor and at least one output transistor having an emitter area which is equal to an integer multiple of the input transistor emitter area where the generated photocurrent from each photodetector is multiplied by an integer equal to the ratio of the output divided by the input transistor emitter area so as to provide an integer multiplied current as an output signal;
- and
- wherein the output signal is selectively switched through a plurality of amplifiers having positive gain during periods where the photosensor is receiving incident light and negative gain during periods where the photosensor is not receiving incident light.
A photosensor array of pixels each of the pixels comprising:
- a current generating photodetector having a photodiode that is operatively coupled in combination with an associated multiplying current mirror located within the pixel and comprised of one input transistor and at least one output transistor where the emitter base voltage on the input transistor is biased to produce an integer multiple of the input current at the output transistor's emitter;
- and
- wherein the output signal is selectively switched through a plurality of amplifiers having positive gain during periods where the photosensor is receiving incident light and negative gain during periods where the photosensor is not receiving incident light.
Dependencies are inferred from the claim text.