公开(公告)号：US20230421922A1

公开(公告)日：2023-12-28

申请号：US17849403

申请日：2022-06-24

Applicant: OMNIVISION TECHNOLOGIES, INC.

Inventor： Zhe Gao ,  Chengcheng Xu ,  Dennis Tunglin Lee ,  Tiejun Dai

IPC: H04N5/378 ,  H04N5/355 ,  H01L27/146

CPC classification number: H04N5/378 ,  H04N5/3559 ,  H01L27/14643 ,  H01L27/14612

Abstract: Pixel designs with reduced LOFIC reset and settling times are disclosed herein. In one embodiment, a pixel cell includes a photosensor configured to photogenerate image charge in response to incident light, a floating diffusion to receive the image charge from the photosensor, a transfer transistor coupled between the floating diffusion and the photosensor to transfer the image charge to the floating diffusion, and a first reset transistor coupled between the floating diffusion and the voltage supply. The pixel cell further includes a capacitor having two ends, and a second reset transistor. A first end of the capacitor is coupled to the floating diffusion. The second reset transistor is coupled between a second end of the capacitor and the voltage supply.

公开(公告)号：US11729529B1

公开(公告)日：2023-08-15

申请号：US17825797

申请日：2022-05-26

Applicant: OMNIVISION TECHNOLOGIES, INC.

Inventor： Zhe Gao ,  Hiroaki Ebihara ,  Ling Fu ,  Tiejun Dai

IPC: H04N25/75 ,  H04N25/53 ,  H04N25/62 ,  H04N25/65 ,  H04N25/771 ,  H04N25/532

CPC classification number: H04N25/75 ,  H04N25/53 ,  H04N25/62 ,  H04N25/65 ,  H04N25/771

Abstract: A global shutter readout circuit includes a reset transistor coupled between a reset voltage and a bitline. A pixel enable transistor is coupled between the reset transistor and a source follower transistor. First and second terminals of the pixel enable transistor are coupled together in response to a pixel enable signal coupled to a third terminal of the pixel enable transistor. A first storage transistor coupled to the second terminal of the pixel enable transistor and the gate of the source follower transistor. A first storage capacitor is coupled to the first storage transistor. A second storage transistor coupled to the second terminal of the pixel enable transistor and the gate of the source follower transistor. A second storage capacitor is coupled to the second storage transistor. A row select transistor is coupled to the source follower transistor to generate an output signal from the global shutter readout circuit.

公开(公告)号：US20220239858A1

公开(公告)日：2022-07-28

申请号：US17156290

申请日：2021-01-22

Applicant: OMNIVISION TECHNOLOGIES, INC.

Inventor： Tiejun Dai ,  Shoushun Chen ,  Zhe Gao

IPC: H04N5/3745 ,  H04N5/378 ,  H04N5/355 ,  H01L27/146

Abstract: An event driven pixel includes a photodiode configured to photogenerate charge in response to incident light received from an external scene. A photocurrent to voltage converter is coupled to the photodiode to convert photocurrent generated by the photodiode to a voltage. A filter amplifier is coupled to the photocurrent to voltage converter to generate a filtered and amplified signal in response to the voltage received from the photocurrent to voltage converter. A threshold comparison stage is coupled to the filter amplifier to compare the filtered and amplified signal received from the filter amplifier with thresholds to asynchronously detect events in the external scene in response to the incident light. A digital time stamp generator is coupled to asynchronously generate a digital time stamp in response to the events asynchronously detected in the external scene by the threshold comparison stage.

公开(公告)号：US20220199671A1

公开(公告)日：2022-06-23

申请号：US17125619

申请日：2020-12-17

Applicant: OMNIVISION TECHNOLOGIES, INC.

Inventor： Zhe Gao ,  Ling Fu ,  Qing Qin ,  Tiejun Dai

IPC: H01L27/146 ,  H04N5/351 ,  H04N5/3745

Abstract: An event driven sensor includes an arrangement of photodiodes including an inner portion laterally surrounded by an outer portion. An outer pixel cell circuit is coupled to generate an outer pixel value in response to photocurrent generated by the outer portion. The outer pixel value is a binned signal representative of an average value of brightness of incident light on the arrangement of photodiodes. An inner pixel cell circuit is coupled to the inner portion to generate an inner pixel value in response to photocurrent generated by from the inner portion. An event driven circuit is coupled to the outer pixel cell circuit and the inner pixel cell circuit. The event driven circuit is coupled to generate an output signal responsive to an inner brightness indicated by the inner pixel value relative to an outer brightness indicated by the outer pixel value.

公开(公告)号：US11206392B1

公开(公告)日：2021-12-21

申请号：US16931194

申请日：2020-07-16

Applicant: OMNIVISION TECHNOLOGIES, INC.

Inventor： Liang Zuo ,  Min Qu ,  Xuelian Liu ,  Rui Wang ,  Zhe Gao ,  Zhiyong Zhan

IPC: H04N17/00 ,  H04N5/3745 ,  H04N5/378

Abstract: An image sensor includes a pixel array with active rows of pixel cells, a black level calibration row with black image data generation circuits coupled to generate black image data signals representative of an absence of the incident light, and a dummy row with black level clamping circuits coupled to receive a black sun reference voltage to clamp bitlines of the pixel array, and a black level calibration circuit coupled to receive the black sun reference voltage to generate a black sun calibration voltage. A black sun feedback circuit is coupled to generate the black sun reference voltage in response to the black sun calibration voltage and a black level sample reference, and a black level sampling circuit is coupled to the bitlines to sample the black image data signals to generate the black level sample reference received by the black sun feedback circuit.

公开(公告)号：US20210344867A1

公开(公告)日：2021-11-04

申请号：US16862337

申请日：2020-04-29

Applicant: OMNIVISION TECHNOLOGIES, INC.

Inventor： Zhe Gao ,  Tiejun Dai

IPC: H04N5/3745 ,  H04N5/378

Abstract: An image sensor includes a source follower coupled to a photodiode to generate an image signal responsive to photogenerated charge. The image signal is received by image readout circuitry through a row select transistor. A reset transistor resets the photogenerated charge. A first node of mode select circuit is coupled to the reset transistor, a second node is coupled to a pixel supply voltage, and a third node is coupled to an event driven circuit. The mode select circuit couples the first node to the second node during an imaging mode to supply the pixel supply voltage to the reset transistor. The mode select circuit is further configured to couple the first node to the third node during an event driven mode to couple a photocurrent of the photodiode to drive the event driven circuit through the reset transistor to detect changes in the photocurrent.

公开(公告)号：US20210021769A1

公开(公告)日：2021-01-21

申请号：US16516067

申请日：2019-07-18

Applicant: OmniVision Technologies, Inc.

Inventor： Zhe Gao ,  Ling Fu ,  Yu-Shen Yang ,  Tiejun Dai

IPC: H04N5/345 ,  G11C27/02 ,  H04N5/378 ,  H04N5/369

Abstract: A switch driver circuit includes a first transistor coupled between a voltage supply and a first output node. A second transistor is coupled between the first output node and a first discharge node. A first slope control circuit is coupled to the first discharge node to discharge the first discharge node at a first slope. A third transistor is coupled between the voltage supply and a second output node. A fourth transistor is coupled between the second output node and a second discharge node. A second slope control circuit coupled to the second discharge node to discharge the second discharge node at a second slope. The first and second slopes are mismatched.