CMOS APS with stacked avalanche multiplication layer and low voltage readout electronics
AssigneeMicron Technology, Inc.
InventorsIsao Takayanagi, Junichi Nakamura
Life of this patent
Estimating the term…
Abstract
An image sensor includes a pixel having a protection circuit connected to a charge multiplying photoconversion layer. The protection circuit prevents the pixel circuit from breaking down when the voltage in the pixel circuit reaches the operating voltage applied to the charge multiplying photoconversion layer in response to the image sensor being exposed to a strong light. The protection circuit causes additional voltage entering the pixel circuit from the charge multiplying photoconversion layer over a predetermined threshold voltage level to be dissipated from the storage node and any downstream components.
Claims17
1-28. (canceled)
An image sensor comprising:
- a charge multiplying photoconversion layer;
- and
- an image sensor pixel array having a plurality of pixels, wherein each pixel comprises:
- an output circuit connected to the charge multiplying photoconversion layer,
- wherein the charge multiplying photoconversion layer includes an upper plate for receiving a light signal, and a lower plate through which a charge multiplied signal current is fed to the output circuit, and wherein the output circuit fixes the voltage level of the bottom plate at a voltage Vref, and
- a protection circuit electrically connected to the bottom plate of the charge multiplying photoconversion layer and an input to the output circuit.
40-43. (canceled)
A method for obtaining an image signal, comprising:
- detecting a light signal in an image sensor;
- photoconverting the light signal into an electrical signal in a photoconversion layer in the image sensor;
- amplifying the electrical signal in the photoconversion layer;
- fixing the voltage level at the output of the photoconversion layer to a predetermined value;
- and
- converting the amplified signal output from the photoconversion layer into a logarithmic signal.
A method for obtaining an image signal, comprising:
- detecting a light signal in an image sensor;
- photoconverting the light signal into an electrical signal in a photoconversion layer in the image sensor;
- amplifying the electrical signal in the photoconversion layer;
- fixing the voltage level at the output of the photoconversion layer to a predetermined value;
- and
- converting the amplified signal outputted from the photoconversion layer into a logarithmic signal when the intensity of the detected light signal reaches a predetermined threshold level.
An image processing apparatus comprising:
- an image sensor for detecting an image and outputting image signals corresponding to the detected image;
- and
- an image processor for processing the image signals outputted from the image sensor,
- wherein the image sensor comprises:
- a charge multiplying photoconversion layer;
- and
- a pixel array having a plurality of pixels, wherein each pixel includes
- a charge storage element electrically connected to the charge multiplying photoconversion layer, and
- a protection circuit electrically connected to the charge storage element for limiting a voltage which accumulates at the charge storage element.
A processing system, comprising:
- a processor for receiving and processing image data;
- and
- an image data generator for supplying image data to the processor, the image data generator comprising
- an image sensor for obtaining an image and outputting an image signal,
- an image processor for processing the image signal, and
- a controller for controlling the image sensor and the image processor,
- wherein the image sensor comprises:
- a charge multiplying photoconversion layer;
- and
- a pixel array having a plurality of pixels, wherein each pixel includes
- a charge storage element electrically connected to the charge multiplying photoconversion layer, and
- a protection circuit electrically connected to the charge storage element for limiting a voltage which accumulates at the charge storage element.
Dependencies are inferred from the claim text.