Abstract:
An image sensor includes a pixel array and a plurality of control circuits. The pixel array includes a plurality of sub-arrays arranged in a plurality of rows and columns, each of the plurality of sub-arrays including a plurality of pixels. The plurality of control circuits are coupled to the pixel array, and configured to control exposure of the plurality of sub-arrays. At least a first of the plurality of control circuits is configured to control exposure of a first of the plurality of sub-arrays according to a first set of exposure times. At least a second of the plurality of control circuits is configured to control exposure of a second of the plurality of sub-arrays according to a second set of exposure times. The first set of exposure times is different from the second set of exposure times.
Abstract:
At least one example embodiment discloses a method of generating an image using a global shutter image sensor. The method includes accumulating a first plurality of charges during a first exposure time from a first plurality of pixels, accumulating a second plurality of charges during a plurality of second exposure times from a second plurality of pixels, the plurality of second exposure times occurring during the first exposure time and being shorter than the first exposure time and generating the image based on the first plurality of charges and the second plurality of charges.
Abstract:
Methods of calibrating a linear-logarithmic image sensor pixel include performing a reset of the pixel in advance of establishing a leakage current between a photodiode and a floating diffusion region of the pixel. A first voltage of the floating diffusion region is then read through a source follower and selection transistor, after the leakage is terminated. A step is then performed to transfer charge between the photodiode and the floating diffusion region of the pixel so that a voltage of a cathode of the photodiode is increased. Thereafter, a second voltage of the floating diffusion region is read. The first and second read voltages are then used to perform a calibration operation. These steps may be repeated to establish another leakage current of different duration/magnitude and yield third and fourth read voltages, which support further calibration.
Abstract:
An image sensor includes a line driver, which further includes a transfer pulse generating circuit. The transfer pulse generating circuit is configured to determine an integration status of a first group of pixels, and to selectively apply the anti-blooming shutter to the first group of pixels based on the determined integration status of the first group of pixels.
Abstract:
Methods of calibrating a linear-logarithmic image sensor pixel include performing a reset of the pixel in advance of establishing a leakage current between a photodiode and a floating diffusion region of the pixel. A first voltage of the floating diffusion region is then read through a source follower and selection transistor, after the leakage is terminated. A step is then performed to transfer charge between the photodiode and the floating diffusion region of the pixel so that a voltage of a cathode of the photodiode is increased. Thereafter, a second voltage of the floating diffusion region is read. The first and second read voltages are then used to perform a calibration operation. These steps may be repeated to establish another leakage current of different duration/magnitude and yield third and fourth read voltages, which support further calibration.
Abstract:
Methods of performing two point calibration of a linear-logarithmic image sensor pixel include measuring voltages of a floating diffusion region of the pixel after establishing a plurality of unequal sub-threshold currents through a transfer transistor of the pixel. These sub-threshold currents operate to sequentially increase a voltage of the floating diffusion region to respective voltage levels that enable knee-point (KNPT) voltage and logarithmic sensitivity (LOGS) determination. The methods also include depleting a photodiode within the pixel by driving a cathode of the photodiode with a pull-up current in advance of establishing the sub-threshold currents. The method is photocurrent-independent.
Abstract:
Methods of performing two point calibration of a linear-logarithmic image sensor pixel include measuring voltages of a floating diffusion region of the pixel after establishing a plurality of unequal sub-threshold currents through a transfer transistor of the pixel. These sub-threshold currents operate to sequentially increase a voltage of the floating diffusion region to respective voltage levels that enable knee-point (KNPT) voltage and logarithmic sensitivity (LOGS) determination. The methods also include depleting a photodiode within the pixel by driving a cathode of the photodiode with a pull-up current in advance of establishing the sub-threshold currents. The method is photocurrent-independent.