An image sensor includes a pixel array including a plurality of pixels each including a photosensitive element, and a readout circuit, wherein the pixels are arranged in at least two columns, within each column at least some of the pixels of the column are connected with a common column bus, respectively, for each column the readout circuit includes a first analog-to-digital converter (ADC) and a second ADC, for each column the first ADC is connected with the column bus, and for each column the second ADC is connectable with at least one of the column bus and a reference potential or the second ADC is connected with one optically shielded pixel of the pixel array.

An image sensor includes a pixel array including a plurality of pixels each including a photosensitive element, and a readout circuit, wherein the pixels are arranged in at least two columns, within each column at least some of the pixels of the column are connected with a common column bus, respectively, for each column the readout circuit includes a first analog-to-digital converter (ADC) and a second ADC, for each column the first ADC is connected with the column bus, and for each column the second ADC is connectable with at least one of the column bus and a reference potential or the second ADC is connected with one optically shielded pixel of the pixel array.

An image sensing device including a pixel array including a plurality of pixels and an analog-to-digital converter (ADC) configured to convert an analog signal into a digital signal is provided. The ADC includes a first circuit configured to receive the analog signal from a selected pixel among the plurality of pixels and generate a first output signal and a second circuit including a select transistor configured to apply a voltage to a floating node electrically connected to the select transistor based on the first output signal. The second circuit further includes a capacitor connected in parallel between a gate and a drain of the select transistor and an output circuit connected to the floating node and configured to output the digital signal based on the applied voltage to the floating node.

An analogue to digital converter for converting the analogue output of a dual conversion gain pixel of an image sensor. The dual conversion gain pixel is operable to sequentially output a reset pixel value and a signal pixel value sequentially with both a first gain and a second gain different to the first gain. An image sensor comprising the analogue to digital converter, a system comprising the image sensor and a method are also described herein.

Correlated double sampling column-level readout of an image sensor pixel (e.g., a CMOS image sensor) may be provided by a charge transfer amplifier that is configured and operated to itself provide for both correlated-double-sampling and amplification of floating diffusion potentials read out from the pixel onto a column bus after reset of the floating diffusion (i) but before transferring photocharge to the floating diffusion (the reset potential) and (ii) after transferring photocharge to the floating diffusion (the transfer potential). A common capacitor of the charge transfer amplifier may sample both the reset potential and the transfer potential such that a change in potential (and corresponding charge change) on the capacitor represents the difference between the transfer potential and reset potential, and the magnitude of this change is amplified by the charge change being transferred between the common capacitor and a second capacitor selectively coupled to the common capacitor.

Correlated double sampling column-level readout of an image sensor pixel (e.g., a CMOS image sensor) may be provided by a charge transfer amplifier that is configured and operated to itself provide for both correlated-double-sampling and amplification of floating diffusion potentials read out from the pixel onto a column bus after reset of the floating diffusion (i) but before transferring photocharge to the floating diffusion (the reset potential) and (ii) after transferring photocharge to the floating diffusion (the transfer potential). A common capacitor of the charge transfer amplifier may sample both the reset potential and the transfer potential such that a change in potential (and corresponding charge change) on the capacitor represents the difference between the transfer potential and reset potential, and the magnitude of this change is amplified by the charge change being transferred between the common capacitor and a second capacitor selectively coupled to the common capacitor.

Techniques provided herein are directed toward a simplified correlated double sampling (CDS) circuit that reduces the amount of components and potential noise sources utilized to two switches and a capacitor. Such CDS circuits can be used in conjunction with downstream programmable gain amp (PGA) circuitry to provide double sampling along with variable gain and/or other features. Embodiments may further utilize one or more analog muxes to reduce parasitic capacitance and increase accuracy.

An image sensor including contiguous color filters is disclosed. The image sensor includes a grid disposed between color filters, a first reflective layer disposed over an upper portion of the grid and patterned to include first reflective structures at borders between adjacent sensor pixels to reflect light, and a second reflective layer disposed over and spaced from the first reflective layer and patterned to include second reflective structures at borders between adjacent sensor pixels to reflect light, and each second reflective structure formed in an angular shape to direct reflected light incident to borders between adjacent sensor pixels into adjacent sensor pixels.

A comparing circuit may include a first amplifier and a second amplifier. The first amplifier performs a correlated double sampling operation in response to a pixel signal and a ramp signal, and the second amplifier amplifies an output signal of the first amplifier. The second amplifier includes a current stabilization circuit that supplies current to the second amplifier during the correlated double sampling operation irrespective of the output signal of the first amplifier.

An image sensor pixel may include a photodiode, a charge storage region, a floating diffusion node, and a capacitor. A first transistor may be coupled between the photodiode and the charge storage region. A second transistor may be coupled between the charge storage region and the capacitor. The photodiode may generate image signals corresponding to incident light. Multiple image signals may be summed at the charge storage region. The second transistor may determine a portion of the image signal that may be sent to the capacitor for storage. The portion of the image signal that is sent to the capacitor may be a low gain signal. A remaining portion of the image signal may be a high gain signal. The image sensor pixel may also include readout circuitry that is configured to readout low and high gain signals stored at the floating diffusion node in a double-sampling readout operation.