Abstract: An imaging device includes groupings of photodiodes having four photodiodes. A transfer transistor is between each photodiode and a floating diffusion. Each floating diffusion is coupled to up to two photodiodes per grouping at a time through transfer transistors. A buffer transistor is coupled to each floating diffusion. The buffer transistors may be in a first or second grouping of buffer transistors. A first bit line is coupled to up to two buffer transistors of the first grouping and a second bit line is coupled to up to two buffer transistors of the second grouping of buffer transistors at a time. A color filter array including a plurality of groupings of color filters is disposed over respective photodiodes of the photodiode array, wherein each grouping of color filters includes four color filters having a same color, wherein each grouping of color filters overlaps two groupings of photodiodes.

Abstract: An imaging device includes a first pixel circuit having a first plurality of photodiodes that includes a phase detection autofocus photodiode with image sensing photodiodes. A first buffer transistor having a first threshold voltage is coupled to the first plurality of photodiodes to generate a first output signal. A second pixel circuit is included having a second plurality of photodiodes that are all image sensing photodiodes. A second buffer transistor having a second threshold voltage is coupled to the second plurality of photodiodes to generate a second output signal. The first threshold voltage is less than the second threshold voltage. A driver is coupled to receive a combination of the first and second output signals to generate a total output signal. An influence of the first output signal dominates the second output signal in the total output signal because the first threshold voltage is less than the second threshold voltage.

Abstract: An imaging device includes groupings of photodiodes having four photodiodes. A transfer transistor is between each photodiode and a floating diffusion. Each floating diffusion is coupled to up to two photodiodes per grouping at a time through transfer transistors. A buffer transistor is coupled to each floating diffusion. The buffer transistors may be in a first or second grouping of buffer transistors. A first bit line is coupled to up to two buffer transistors of the first grouping and a second bit line is coupled to up to two buffer transistors of the second grouping of buffer transistors at a time. A color filter array including a plurality of groupings of color filters is disposed over respective photodiodes of the photodiode array, wherein each grouping of color filters includes four color filters having a same color, wherein each grouping of color filters overlaps two groupings of photodiodes.

Abstract: An image sensor pixel array comprises a plurality of image pixel units to gather image information and a plurality of phase detection auto-focus (PDAF) pixel units to gather phase information. Each of the PDAF pixel units includes two of first image sensor pixels covered by two micro-lenses, respectively. Each of the image pixel units includes four of second image sensor pixels adjacent to each other, wherein each of the second image sensor pixels is covered by an individual micro-lens. A coating layer is disposed on the micro-lenses and forms a flattened surface across the whole image sensor pixel array. A PDAF micro-lens is formed on the coating layer to cover the first image sensor pixels.

Abstract: An imaging device includes groupings of photodiodes having four photodiodes. A transfer transistor is between each photodiode and a floating diffusion. Each floating diffusion is coupled to up to two photodiodes per grouping at a time through transfer transistors. A buffer transistor is coupled to each floating diffusion. The buffer transistors may be in a first or second grouping of buffer transistors. A first bit line is coupled to up to two buffer transistors of the first grouping and a second bit line is coupled to up to two buffer transistors of the second grouping of buffer transistors at a time. A color filter array including a plurality of groupings of color filters is disposed over respective photodiodes of the photodiode array, wherein each grouping of color filters includes four color filters having a same color, wherein each grouping of color filters overlaps two groupings of photodiodes.

Abstract: An imaging device includes groupings of photodiodes having four photodiodes. A transfer transistor is between each photodiode and a floating diffusion. Each floating diffusion is coupled to up to two photodiodes per grouping at a time through transfer transistors. A buffer transistor is coupled to each floating diffusion. The buffer transistors may be in a first or second grouping of buffer transistors. A first bit line is coupled to up to two buffer transistors of the first grouping and a second bit line is coupled to up to two buffer transistors of the second grouping of buffer transistors at a time. A color filter array including a plurality of groupings of color filters is disposed over respective photodiodes of the photodiode array, wherein each grouping of color filters includes four color filters having a same color, wherein each grouping of color filters overlaps two groupings of photodiodes.

Abstract: An imaging device includes a first pixel circuit having a first plurality of photodiodes that includes a phase detection autofocus photodiode with image sensing photodiodes. A first buffer transistor having a first threshold voltage is coupled to the first plurality of photodiodes to generate a first output signal. A second pixel circuit is included having a second plurality of photodiodes that are all image sensing photodiodes. A second buffer transistor having a second threshold voltage is coupled to the second plurality of photodiodes to generate a second output signal. The first threshold voltage is less than the second threshold voltage. A driver is coupled to receive a combination of the first and second output signals to generate a total output signal. An influence of the first output signal dominates the second output signal in the total output signal because the first threshold voltage is less than the second threshold voltage.

Abstract: An image sensor pixel array comprises a plurality of image pixel units to gather image information and a plurality of phase detection auto-focus (PDAF) pixel units to gather phase information. Each of the PDAF pixel units includes two of first image sensor pixels covered by two micro-lenses, respectively. Each of the image pixel units includes four of second image sensor pixels adjacent to each other, wherein each of the second image sensor pixels is covered by an individual micro-lens. A coating layer is disposed on the micro-lenses and forms a flattened surface across the whole image sensor pixel array. A PDAF micro-lens is formed on the coating layer to cover the first image sensor pixels.

Abstract: An image sensor includes a plurality of photodiodes disposed in a semiconductor material and a plurality of transfer transistors. Individual transfer transistors in the plurality of transfer transistors are coupled to individual photodiodes in the plurality of photodiodes. A floating diffusion is also coupled to the plurality of transfer transistors to receive image charge from the plurality of photodiodes. The floating diffusion is coupled to receive a preset voltage, and the preset voltage is substantially equal a dark condition steady-state read voltage.

Abstract: An image sensor includes a plurality of photodiodes disposed in a semiconductor material and a plurality of transfer transistors. Individual transfer transistors in the plurality of transfer transistors are coupled to individual photodiodes in the plurality of photodiodes. A floating diffusion is also coupled to the plurality of transfer transistors to receive image charge from the plurality of photodiodes. The floating diffusion is coupled to receive a preset voltage, and the preset voltage is substantially equal a dark condition steady-state read voltage.

Abstract: A reset level in a pixel cell is boosted by switching ON a reset transistor of the pixel cell to charge the floating diffusion to a first reset level during a reset operation. A select transistor is switched from OFF to ON during the floating diffusion reset operation to discharge an output terminal of an amplifier transistor. The reset transistor is switched OFF after the output terminal of the amplifier transistor has been discharged in response to the switching ON of the select transistor. The output terminal of the amplifier transistor charges to a static level after being discharged. The floating diffusion coupled to the input terminal of the amplifier transistor follows the output terminal of the amplifier transistor across an amplifier capacitance coupled between the input terminal and the output terminal of the amplifier transistor to boost the reset level of the floating diffusion.

Abstract: A reduced random telegraph signal (RTS)-noise CMOS image sensor includes a pixel and a correlated double sampling (CDS) circuit electrically connected to the pixel. The CDS circuit is characterized by a CDS period that includes a reference sample period and an image data sample period. The image sensor also includes a bitline, a bitline connection switch between the pixel and a readout circuit connected to the pixel, and a bitline switch controller. The bitline transmits a transfer gate signal as a bitline signal having a non-zero value during a first time period entirely between the reference sample period and the image data sample period. The bitline switch controller is electrically connected to and configured to control the bitline connection switch such that the bitline connection switch is closed during the entire CDS period except for a single continuous open period that includes the first time period.

Abstract: A reset level in a pixel cell is boosted by switching ON a reset transistor of the pixel cell to charge the floating diffusion to a first reset level during a reset operation. A select transistor is switched from OFF to ON during the floating diffusion reset operation to discharge an output terminal of an amplifier transistor. The reset transistor is switched OFF after the output terminal of the amplifier transistor has been discharged in response to the switching ON of the select transistor. The output terminal of the amplifier transistor charges to a static level after being discharged. The floating diffusion coupled to the input terminal of the amplifier transistor follows the output terminal of the amplifier transistor across an amplifier capacitance coupled between the input terminal and the output terminal of the amplifier transistor to boost the reset level of the floating diffusion.

Abstract: A backside illuminated image sensor includes a semiconductor layer having a back-side surface and a front-side surface. The semiconductor layer includes a pixel array region including a plurality of photodiodes configured to receive image light through the back-side surface of the semiconductor layer. The semiconductor layer also includes a peripheral circuit region including peripheral circuit elements for operating the plurality of photodiodes that borders the pixel array region. The peripheral circuit elements emit photons. The peripheral circuit region also includes a doped semiconductor region positioned to absorb the photons emitted by the peripheral circuit elements to prevent the plurality of photodiodes from receiving the photons.

Abstract: A backside illuminated image sensor includes a semiconductor layer having a back-side surface and a front-side surface. The semiconductor layer includes a pixel array region including a plurality of photodiodes configured to receive image light through the back-side surface of the semiconductor layer. The semiconductor layer also includes a peripheral circuit region including peripheral circuit elements for operating the plurality of photodiodes that borders the pixel array region. The peripheral circuit elements emit photons. The peripheral circuit region also includes a doped semiconductor region positioned to absorb the photons emitted by the peripheral circuit elements to prevent the plurality of photodiodes from receiving the photons.

Abstract: An improved active pixel sensor soft reset circuit for reducing image lag while maintaining low reset kTC noise. The circuit pulls down the sensor potential to a sufficiently low level before the soft reset function is completed. The level to which the sensor potential is pulled is set between 0 and the critical potential at which the reset transistor will be on when the soft reset function begins. The timing of the pull down function is such that the sensor is stabilized at the low potential before the soft reset function completes. In one embodiment, the sensor potential is pulled down using a pull-down circuit, which may consist of a CMOS type inverter. In another embodiment, the sensor potential is pulled down by the bit line. Two ways in which the bit line may be pulled down are natural discharge, or by increasing the bias on the loading transistor. Two ways in which the bias on the loading transistor may be increased are a biasing circuit, or by using a pull-down transistor.

Abstract: A method of reading out a pixel signal from a pixel is disclosed. The method comprises first capturing a first black reference signal from the pixel prior to the pixel starting an integration period. Next, after completion of the integration period, a pixel signal is captured. Next, a second black reference signal is captured following completion of the integration period. Finally, the first black reference signal, second black reference signal, and pixel signal is output.

Abstract: An improved active pixel sensor soft reset circuit for reducing image lag while maintaining low reset kTC noise. The circuit pulls down the sensor potential to a sufficiently low level before the soft reset function is completed. The level to which the sensor potential is pulled is set between 0 and the critical potential at which the reset transistor will be on when the soft reset function begins. The timing of the pull down function is such that the sensor is stabilized at the low potential before the soft reset function completes. In one embodiment, the sensor potential is pulled down using a pull-down circuit, which may consist of a CMOS type inverter. In another embodiment, the sensor potential is pulled down by the bit line. Two ways in which the bit line may be pulled down are natural discharge, or by increasing the bias on the loading transistor. Two ways in which the bias on the loading transistor may be increased are a biasing circuit, or by using a pull-down transistor.

Abstract: An improved active pixel sensor soft reset circuit for reducing image lag while maintaining low reset kTC noise. The circuit pulls down the sensor potential to a sufficiently low level before the soft reset function is completed. The level to which the sensor potential is pulled is set between 0 and the critical potential at which the reset transistor will be on when the soft reset function begins. The timing of the pull down function is such that the sensor is stabilized at the low potential before the soft reset function completes. In one embodiment, the sensor potential is pulled down using a pull-down circuit, which may consist of a CMOS type inverter. In another embodiment, the sensor potential is pulled down by the bit line. Two ways in which the bit line may be pulled down are natural discharge, or by increasing the bias on the loading transistor. Two ways in which the bias on the loading transistor may be increased are a biasing circuit, or by using a pull-down transistor.

Abstract: A method of reading out a pixel signal from a pixel is disclosed. The method comprises first capturing a first black reference signal from the pixel prior to the pixel starting an integration period. Next, after completion of the integration period, a pixel signal is captured. Next, a second black reference signal is captured following completion of the integration period. Finally, the first black reference signal, second black reference signal, and pixel signal is output.