Semiconductor Components Industries, LLC

Pawan Gilhotra

Nirav Dharia

Richard Scott Johnson

An image sensor pixel may include a photodiode, a floating diffusion, and a transfer gate. Column readout circuitry coupled to the image sensor pixel via a column line. The column readout circuitry may include sample and hold circuitry, comparison circuitry, residual measurement and summation circuitry, counter circuitry, analog-to-digital conversion circuitry, and digital summation circuitry. Column readout circuitry is configured to perform readout operations on a pixel image signal generated for a single frame in one or more portions, thereby extending the dynamic range of the imaging system without modifying pixel structure to generate high-dynamic range images within the single frame.

Apparatus and methods for generating high dynamic range images

An image sensor may include an array of dual conversion gain image pixels arranged in rows and columns. The image pixels arranged along the same column may be coupled to a column line. The column line may be coupled to anti-eclipse control circuitry. In one suitable arrangement, the anti-eclipse control circuitry may include a comparator that compares the output signal on the column line to an anti-eclipse bias voltage. If, during a reset sampling period, the output signal on the column line is less than the anti-eclipse bias voltage, a current source may be used to charge the bottom plate of a dual conversion gate capacitor in the selected image pixel to help restore the voltage of the floating diffusion node in the selected pixel.

Image sensors with dual conversion gain pixels and anti-eclipse circuitry

An imaging device may have an array of image sensor pixels and image readout circuitry coupled to the array of image sensor pixels. Predictive pre-charge circuitry may be coupled to the array of image sensor pixels and the image readout circuitry. The predictive pre-charge circuitry and the image readout circuitry may perform correlated double sampling operations during charge readout, comparing the charge generated by the array of image pixels to a known reset value. The predictive pre-charge circuitry may pre-charge output lines from the array of image pixels, thereby reducing the time needed for the circuitry to read out the charge after being reset. The output lines may be pre-charged prior to reading out the charge of a row of image sensor pixels based on a voltage associated with the charge generated by at least one previous row of image sensor pixels of the array of image sensor pixels.

Image sensors with predictive pre-charging circuitry

An image sensor may include an array of image pixels arranged in rows and columns. Image pixels arranged along the same column may be coupled to a column line. The column line may be coupled to anti-eclipse control circuitry. In one suitable arrangement, the anti-eclipse control circuitry may include a comparator that compares the output signal on the column line to an anti-eclipse bias voltage. If, during a reset sampling period, the output signal on the column line is less than the anti-eclipse bias voltage, a transistor may be asserted that couples the floating diffusion region in the pixel to a power supply terminal. Using this arrangement, at least a minimum pixel level may be output when the eclipse condition is met and noise from the reset sample will correlated to noise in the incident light sample.

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Newark, CA, United States of America

Pawan Gilhotra