Patent ID: 7701499
Filing Date: 2010-04-20
Classification: H04N

Abstract:
1. A method of expanding a dynamic range of an electronic imaging device, said method comprising: a. providing a sensor chip comprised of a one or two-dimensional array of pixels and a centrally located sensor-chip logic area, wherein a global exposure time interval of a frame begins with reset signals and ends with sample signals; b. providing a comparator and reset trigger circuit located at or near a site of each of said pixels, wherein said comparator triggers a reset mechanism when a voltage in a charged pixel reaches a reference voltage; whereby, during said global exposure time interval, each individual pixel can be self-reset several times, depending on an intensity of a radiation incident upon it, and, at an end of said global exposure time interval, each pixel contains only a residual value of voltage that remains from a last self-reset to the end of said global integration time interval; and c. providing an algorithm implemented on post acquisition data, wherein said algorithm comprises steps of: i. using a time and/or space continuity assumption and an adjacent pixel inference rule to determine a number of individual resets for each of said pixels; and ii. using said determined number of individual resets for each of said pixels, said residual value for each of said pixels, and a basic formula to determine a true image value for each of said pixels; wherein, a true image is comprised of an array of said true image values for each of said pixels and a combination of said reset mechanism for each pixel in conjunction with the use of said algorithm allows a determination of said true image without the necessity of providing electronic components for counting and remembering the number of times that each of said pixels was reset.