Increasing dynamic range using multisampling
First Claim
Patent Images
1. A method for operating an image sensor, said method comprising:
- exposing each of a plurality of pixels in said image sensor for a respective first exposure time;
measuring a respective response of each of said plurality of pixels to said respective first exposure time; and
exposing each of said plurality of pixels for a respective second exposure time that depends for each pixel on said respective measured response of each of said plurality of pixels, wherein, for a group of pixels including a first pixel and second pixel read using a common row read signal, the respective second exposure times for the first pixel and the second pixel start at different times and end at a common time, and wherein the exposing comprises, for a sub-plurality of pixels sharing a common row reset signal;
asserting the common row reset signal a plurality of times during an exposure period; and
for each of the pixels in the sub-plurality, preventing the common row reset signal from causing a reset at any of the plurality of times that occur closer to the end of the exposure period than the respective second exposure time.
1 Assignment
0 Petitions
Accused Products
Abstract
Methods and systems for increasing the effective dynamic range of an image sensor are disclosed. Each pixel in the sensor is exposed for a respective first exposure time. Each pixel'"'"'s response to the respective first exposure is measured and compared to threshold values. Based on the pixel'"'"'s response to the respective first exposure time, an optimal exposure is calculated for each pixel. The optimal exposure time is applied to each pixel by utilizing row-enabled and column-enabled signals at each pixel within the sensor.
31 Citations
25 Claims
-
1. A method for operating an image sensor, said method comprising:
-
exposing each of a plurality of pixels in said image sensor for a respective first exposure time; measuring a respective response of each of said plurality of pixels to said respective first exposure time; and exposing each of said plurality of pixels for a respective second exposure time that depends for each pixel on said respective measured response of each of said plurality of pixels, wherein, for a group of pixels including a first pixel and second pixel read using a common row read signal, the respective second exposure times for the first pixel and the second pixel start at different times and end at a common time, and wherein the exposing comprises, for a sub-plurality of pixels sharing a common row reset signal; asserting the common row reset signal a plurality of times during an exposure period; and for each of the pixels in the sub-plurality, preventing the common row reset signal from causing a reset at any of the plurality of times that occur closer to the end of the exposure period than the respective second exposure time. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
-
-
11. An image sensor, said sensor comprising:
-
logic to expose each of a plurality of pixels in said image sensor for a respective first exposure time; logic to measure a respective response of each of said plurality of pixels to said respective first exposure time; and logic to expose each of said plurality of pixels for a respective second exposure time that depends for each pixel on said respective measured response of each of said plurality of pixels, wherein, for a group of pixels including a first pixel and second pixel read using a common row read signal, the respective second exposure times for the first pixel and the second pixel start at different times and end at a common time, and wherein the logic to expose comprises logic that, for a sub-plurality of pixels sharing a common row reset signal; asserts the common row reset signal a plurality of times during an exposure period; and for each of the pixels in the sub-plurality, prevent the common row reset signal from causing a reset at any of the plurality of times that occur closer to the end of the exposure period than the respective second exposure time. - View Dependent Claims (12, 13, 14, 15, 16, 17, 18, 19, 20, 25)
-
-
21. A high dynamic range image sensor comprising:
-
a pixel array comprising a plurality of pixels, each pixel in said array comprising logic for receiving a plurality of row-enabled signals effective to reset said pixel and a plurality of column-enabled signals effective to mask at least one of said plurality of row-enabled signals; and exposure logic coupled to said pixel array, said exposure logic configured to; expose each of said plurality of pixels in said pixel array for a respective first exposure time; measure a response of each of said plurality of pixels to said first respective exposure time; and expose each of said plurality of pixels for a second respective exposure time that depends for each pixel on said respective measured response of each of said plurality of pixels, wherein for a first pixel and a second pixel in the pixel array that are read using a common row read signal, the respective second exposure times for the first pixel and the second pixel start at different times and end at a common time, wherein said exposure logic, for a sub-plurality of pixels sharing a common row reset signal, is further configured to; assert the common row reset signal a plurality of times during an exposure period; and for each of the pixels in the sub-plurality, prevent the common row reset signal from causing a reset at any of the plurality of times that occur closer to an end of the exposure period than the respective second exposure time. - View Dependent Claims (22, 23, 24)
-
Specification