Low light adaptive imaging device
AssigneeEmpire Technology Development LLC
InventorsTakahiro Yamada, Sumio Terakawa
Life of this patent
Estimating the term…
Abstract
Techniques described herein generally relate to digital imaging systems, methods and devices. In some example embodiments, a low light adaptive photoelectric imaging device may include a photoelectric transducer configured to receive and convert incident light into an electric charge that varies in response to an intensity of the received incident light. Some example imaging devices may also include circuitry coupled to the photoelectric transducer and configured to electrically float a potential at one or more terminals of the photoelectric transducer effective to cause the photoelectric transducer to amplify the electric charge according to a gain function that non-linearly varies relative to the intensity of the received incident light.
Claims20
A low light adaptive photoelectric imager comprising:
- a phototransistor including an intrinsic gate, an extrinsic gate, and a drain,
- wherein the phototransistor is configured to receive incident light at least at the extrinsic gate and to convert the received incident light into an electric charge that varies responsive to an intensity of the received incident light,
- wherein the extrinsic gate and the drain are extrinsically doped such that a depletion capacitance between the intrinsic gate and the drain differs from a depletion capacitance between the intrinsic gate and the extrinsic gate effective to form an electric potential barrier in the phototransistor,
- the electric potential barrier effective to cause a gain of the phototransistor to non-linearly vary responsive to the intensity of the received incident light.
A method to manufacture a low light adaptive photoelectric imager, the method comprising:
- forming an extrinsic well in a semiconductor substrate;
- forming an intrinsic region in the extrinsic well;
- forming a source by doping a first portion of the intrinsic region as a first polarity type of semiconductor material;
- forming a drain by doping a second portion of the intrinsic region as the first polarity type of semiconductor material;
- forming a light-sensitive gate by doping a third portion of the intrinsic region as a second polarity type of semiconductor material, at least a portion of the light-sensitive gate being located between the source and the drain;
- wherein the drain and light-sensitive gate are doped to facilitate formation of a depletion capacitance between the intrinsic region and the drain that differs from a depletion capacitance between the intrinsic region and the light-sensitive gate such that an electric potential barrier is formed during operation of the imager,
- the electric potential barrier being effective to cause a gain of the photoelectric imager to non-linearly vary responsive to an incident light intensity.
An apparatus, comprising:
- a phototransistor that includes an intrinsic gate, an extrinsic gate, a source, and a drain, and configured to receive incident light and convert the incident light into an electric charge that varies responsive to an intensity of the incident light based on a non-linear gain of the phototransistor,
- wherein a depletion capacitance between the intrinsic gate of the phototransistor and the drain of the phototransistor differs from a depletion capacitance between the intrinsic gate and the extrinsic gate of the phototransistor, and wherein an electric potential barrier between the source and the drain is formed due to a difference between the depletion capacitance between the intrinsic gate and the drain and the depletion capacitance between the intrinsic gate and the extrinsic gate.
Dependencies are inferred from the claim text.