Pixel circuit for high dynamic range image sensor

    公开(公告)号:US12185000B2

    公开(公告)日:2024-12-31

    申请号:US17810966

    申请日:2022-07-06

    Abstract: A pixel circuit includes a first photodiode and a second photodiode. The first and second photodiodes photogenerate charge in response to incident light. A first transfer transistor is coupled to the first photodiode. A first floating diffusion is coupled to the first transfer transistor. A second transfer transistor is coupled to the second photodiode. A second floating diffusion is coupled to the second transfer transistor. A dual floating diffusion transistor is coupled between the first and second floating diffusions. An overflow transistor is coupled to the second photodiode. A capacitor is coupled between a voltage source and the overflow transistor. A capacitor readout transistor is coupled between the capacitor and the second floating diffusion. An anti-blooming transistor coupled between the first photodiode and a power line.

    IMAGING SYSTEM WITH SELECTIVE READOUT FOR VISIBLE-INFRARED IMAGE CAPTURE

    公开(公告)号:US20240113146A1

    公开(公告)日:2024-04-04

    申请号:US17957440

    申请日:2022-09-30

    Inventor: Keiji Mabuchi

    Abstract: An imaging system including a sensor wafer and a logic wafer. The sensor wafer includes a plurality of pixels arranged in rows and columns, the plurality of pixels arranged in rows and columns and including at least a first pixel and a second pixel positioned in a first row included in the rows. The sensor wafer includes a first transfer control line associated with the first row, the first transfer control line coupled to both a first transfer gate of the first pixel and a second transfer gate of the second pixel. The logic wafer includes a first storage capacitor associated with the first pixel and a second storage capacitor associated with the second pixel, a first storage control line coupled to a first storage gate associated with the first pixel and a second storage control line coupled to a second storage gate associated with the second pixel.

    High dynamic range split pixel CMOS image sensor with low color crosstalk

    公开(公告)号:US11527569B2

    公开(公告)日:2022-12-13

    申请号:US16877077

    申请日:2020-05-18

    Abstract: A pixel cell includes a plurality of subpixels to generate image charge in response to incident light. The subpixels include an inner subpixel laterally surrounded by outer subpixels. A first plurality of transfer gates disposed proximate to the inner subpixel and a first grouping of outer subpixels. A first floating diffusion is coupled to receive the image charge from the first grouping of outer subpixels through a first plurality of transfer gates. A second plurality of transfer gates disposed proximate to the inner subpixel and the second grouping of outer subpixels. A second floating diffusion disposed in the semiconductor material and coupled to receive the image charge from each one of the second grouping of outer subpixels through the second plurality of transfer gates. The image charge in the inner subpixel is received by the first, second, or both floating diffusions through respective transfer gates.

    Dark current calibration method and associated pixel circuitry

    公开(公告)号:US11350049B2

    公开(公告)日:2022-05-31

    申请号:US17087415

    申请日:2020-11-02

    Inventor: Keiji Mabuchi

    Abstract: Image sensors capable of dark current calibration and associated circuits are disclosed herein. The method for calibrating dark current includes acquiring at least one dark current frame of a first plurality of pixels of a pixel array of the image sensor. The dark current frame contains readings of individual dark currents for the corresponding pixels obtained during an exposure period when a transistor is turned on disabling the photodiode. The method also includes acquiring at least one normal frame of a second plurality of pixels of the pixel array of the image sensor. The normal frame contains readings of individual signals for the corresponding pixels obtained during the exposure period when the transistor is turned OFF. The method includes subtracting the at least one dark current frame from the at least one normal frame.

    DARK CURRENT CALIBRATION METHOD AND ASSOCIATED PIXEL CIRCUITRY

    公开(公告)号:US20220141406A1

    公开(公告)日:2022-05-05

    申请号:US17087415

    申请日:2020-11-02

    Inventor: Keiji Mabuchi

    Abstract: Image sensors capable of dark current calibration and associated circuits are disclosed herein. The method for calibrating dark current includes acquiring at least one dark current frame of a first plurality of pixels of a pixel array of the image sensor. The dark current frame contains readings of individual dark currents for the corresponding pixels obtained during an exposure period when a transistor is turned on disabling the photodiode. The method also includes acquiring at least one normal frame of a second plurality of pixels of the pixel array of the image sensor. The normal frame contains readings of individual signals for the corresponding pixels obtained during the exposure period when the transistor is turned OFF. The method includes subtracting the at least one dark current frame from the at least one normal frame.

    High dynamic range CMOS image sensor design

    公开(公告)号:US11212457B2

    公开(公告)日:2021-12-28

    申请号:US16886473

    申请日:2020-05-28

    Abstract: A pixel cell includes a first subpixel and a plurality of second subpixels. Each subpixel includes a photodiode to photogenerate image charge in response to incident light. Image charge is transferred from the first subpixel to a floating diffusion through a first transfer transistor. Image charge is transferred from the plurality of second subpixels to the floating diffusion through a plurality of second transfer transistors. An attenuation layer is disposed over the first subpixel. The first subpixel receives the incident light through the attenuation layer. The plurality of second subpixels receive the incident light without passing through the attenuation layer. A dual floating diffusion (DFD) transistor is coupled to the floating diffusion. A capacitor is coupled to the DFD transistor.

    WIDE DYNAMIC RANGE IMAGE SENSOR WITH GLOBAL SHUTTER

    公开(公告)号:US20210203865A1

    公开(公告)日:2021-07-01

    申请号:US17204786

    申请日:2021-03-17

    Abstract: An image sensor includes a photodiode disposed in a semiconductor material to generate image charge in response to incident light, and a first transfer gate is coupled to the photodiode to extract image charge from the photodiode in response to a first transfer signal. A first storage gate is coupled to the first transfer gate to receive the image charge from the first transfer gate, and a first output gate is coupled to the first storage gate to receive the image charge from the first storage gate. A first capacitor is coupled to the first output gate to store the image charge.

    MULTI-GATE LATERAL OVERFLOW INTEGRATION CAPACITOR SENSOR

    公开(公告)号:US20210183926A1

    公开(公告)日:2021-06-17

    申请号:US16717768

    申请日:2019-12-17

    Abstract: A pixel circuit includes a photodiode, a floating diffusion, and a conduction gate channel of a multi-gate transfer block disposed in a semiconductor material layer. The multi-gate transfer block is coupled to the photodiode, the floating diffusion, and an overflow capacitor. The multi-gate transfer block also includes first, second, and third gates that are disposed proximate to the single conduction gate channel region. The conduction gate channel is a single region shared among the first, second, and third gates. Overflow image charge generated in the photodiode leaks from the photodiode into the conduction gate channel to the overflow capacitor in response to the first gate, which is coupled between the photodiode and the conduction gate channel, receiving a first gate OFF signal and the second gate, which is coupled between the conduction gate channel and the overflow capacitor, receiving a second gate ON signal.

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