Abstract: A CMOS image sensor includes an image pixel array, a dark pixel array, data bit liens, reference bit lines, a driver, comparators, and analog-to-digital converter (“ADC”) circuits. The image pixel array generates analog image signals in response to incident light. The dark pixel array generates analog black reference signals for analog black level calibration of the analog image signals. In one embodiment, the data bit lines each coupled to a different column of image pixels of the image pixel array and the reference bit lines each coupled to a different column of black reference pixels within the dark pixel array. The driver is coupled to the reference bit lines to drive an analog black reference signal. The comparators each couple to one of the data bit lines and each coupled to an output of the driver and offset the analog image signals with the analog black reference signals in an analog domain. The ADC circuits each coupled to an output of a comparator.

Abstract: A backside illuminated imaging sensor with a seal ring support includes an epitaxial layer having an imaging array formed in a front side of the epitaxial layer. A metal stack is coupled to the front side of the epitaxial layer, wherein the metal stack includes a seal ring formed in an edge region of the imaging sensor. An opening is included that extends from the back side of the epitaxial layer to a metal pad of the seal ring to expose the metal pad. The seal ring support is disposed on the metal pad and within the opening to structurally support the seal ring.

Abstract: A color image sensor includes a pixel array including a CFA overlaying an array of photo-sensors for acquiring a color image. The CFA includes first color filter elements of a first color overlaying a first group of the photo-sensors, second color filter elements of a second color overlaying a second group of the photo-sensors, and a plurality of filter stacks overlaying a third group of the photo-sensors. The first group generates first color signals of a first color channel and the second group generates second color signals of a second color channel. Each of the filter stacks includes a first stacked filter of the first color and a second stacked filter of the second color. A sensitivity of the filter stacks equals a product of sensitivities of the first and the second stacked filters and the filter stacks generate a third color channel.

Abstract: A color image sensor includes a pixel array including CFA overlaying an array of photo-sensors for acquiring color image data. The CFA includes first color filter elements of a first color overlaying a first group of the photo-sensors and second color filter elements of a second color overlaying a second group of the photo-sensors. The first group of photo-sensors generate first color signals of a first color channel and the second group of photo-sensors generate second color signals of a second color channel. The color image sensor further includes a color signal combiner circuit (“CSCC”) coupled to receive the first and second color signals output from the pixel array. The CSCC includes a combiner coupled to combine the first and second colors signals to generate third color signals of a third color channel. An output port is coupled to the CSCC to output the color image data.

Abstract: An imaging system capable of black level calibration includes an imaging pixel array, at least one black reference pixel, and peripheral circuitry. The imaging pixel array includes a plurality of active pixels each coupled to capture image data. The black reference pixel is coupled to generate a black reference signal for calibrating the image data. Light transmitting layers are disposed on a first side of a pixel array die including the imaging system and cover at least the imaging pixel array and the black reference pixel. A light shielding layer is disposed on the first side of the pixel array die and covers a portion of the light transmitting layers and the black reference pixel without covering the imaging pixel array.

Abstract: An image sensor includes a photosensitive region disposed within a semiconductor layer and a stress adjusting layer. The photosensitive region is sensitive to light incident through a first side of the image sensor to collect an image charge. The stress adjusting layer is disposed over the first side of the semiconductor layer to establish a stress characteristic that encourages photo-generated charge carriers to migrate towards the photosensitive region.