Method, apparatus, and system providing an imager with pixels having extended dynamic range
AssigneeMicron Technology, Inc.
InventorNikolai E. Bock
Life of this patent
Estimating the term…
Abstract
The dynamic range of a pixel is increased by using selective photosensor resets during a frame time of image capture at a timing depending on the light intensity that the pixel will be exposed to during the frame time. Pixels that will be exposed to high light intensity are reset later in the frame than pixels that will be exposed to lower light intensity.
Claims45
A method of operating an imager, the method comprising the acts of:
- determining a value of a light intensity that a pixel will be exposed to during a frame time;
- resetting charge accumulated in a photosensor of the pixel during the frame time at a timing determined in response to the determined light intensity;
- transferring the charge on the photosensor at the end of the frame time to a storage region;
- and
- generating a pixel image signal in response to the charge transferred to the storage region.
A method of operating an imager, the method comprising the acts of:
- acquiring information regarding the intensity of light that a pixel will be exposed to during a subsequent image capture period;
- correlating the information with one range of light intensity values within a plurality of ranges of light intensity values;
- and
- using the range of light intensity values to set a timing to reset a charge accumulated in a photosensor of the pixel during the image capture period.
20-25. (canceled)
An imager, comprising:
- a pixel for providing an image output signal, said pixel comprising:
- a photosensor for accumulating charge;
- a storage region for storing charge transferred from the photosensor;
- a transfer transistor for transferring charge from the photosensor to the storage region;
- an anti-blooming transistor connected to the photosensor;
- and
- a photosensor reset transistor connected between a selectively enabled control line and a gate of said anti-blooming transistor for transmitting a first control signal to the gate of the anti-blooming transistor to reset the charge accumulated on the photosensor in accordance with said first control signal and a second control signal applied to a gate of said photosensor reset transistor.
An imager comprising:
- a pixel for providing an image output signal, said pixel comprising:
- a photosensor for accumulating charge;
- a storage region for storing charge transferred from the photosensor;
- a transfer transistor for transferring charge from the photosensor to the storage region;
- and
- a photosensor reset circuit for selectively resetting charge on said photosensor during an image capture period at a time related to a light level received by said photosensor.
35-40. (canceled)
A method of storing values assigned to pixels in a pixel array to memory, comprising the act of:
- storing the location and value assigned to a zone comprised of a plurality of contiguous pixels that are each assigned the same value.
A method of operating an imager, the method comprising the acts of:
- accumulating charge in a first pixel in a pixel array for a first time period during a frame time accumulating charge in a second pixel in the pixel array for a second time period during the frame time,
- wherein the first time period is longer than the second time period, and
- wherein the length of the first and second time periods are determined in response to the brightness to which the two pixels will be exposed during the frame time.
A method of operating an imager, the method comprising the acts of:
- establishing a frame time during which a pixel may capture data, and
- only capturing data for a portion of the frame time in response to the illumination to which the pixel is exposed during the frame period.
Dependencies are inferred from the claim text.