US 12,720,237 B2Granted

Dynamic pixel-wise multi-gain readout for high dynamic range imaging

AssigneeGigajot Technology, Inc.

InventorJiaju Ma

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Abstract

Systems and methods are disclosed to enable fast readout from an image sensor to support pixel-wise conversion gain selection for high dynamic range imaging. In embodiments, an image sensor integrated circuit performs the pixel-wise gain selection with its readout circuitry, so that the image sensor outputs pixels with only the selected gain option. In this manner, the image sensor is able to achieve faster frame rates and lower power consumption. Depending on the embodiment, the conversion gain may be selected by the readout logic, an image signal processor, or an auto-exposure engine. The gain selection may be made based on a previous image captured by the camera or other pixels in the same image. The image signal processor may interpolate a high-gain and a low-gain portion of the image to obtain full resolution images in the two gain options, and merge the two to obtain the final image.

Claims20

Dependent claims

An image sensor integrated circuit, comprising:

a plurality of photodiodes that implement pixels in a pixel array, configured to capture a frame;
and
readout logic for a group of pixels configured to:
receive a gain selection signal indicating respective conversion gains for reading pixel values of the frame from individual ones of the pixels, including a high conversion gain (HCG) and a low conversion gain (LCG);
read at least one first pixel value of the frame from one or more pixels in the group of pixels with the HCG as indicated by the gain selection signal;
read, after the read of the at least one first pixel value, pixel values of the frame from remaining pixels in the group of pixels with LCG as indicated by the gain selection signal in response to determining that the at least one first pixel value satisfies a threshold;
read, after the read of the at least one first pixel value, pixel values of the frame from the remaining pixels in the group of pixels with HCG as indicated by the gain selection signal in response to determining that the at least one first pixel value fails to satisfy the threshold;
and
output the pixel values of the frame via an output interface of the image sensor integrated circuit.

6 more elements

A camera, comprising:

one or more lenses configured to receive light;
an image sensor comprising:
a plurality of photodiodes that implement pixels in a pixel array, configured to capture a frame according to the light;
a regional gain control circuit asserting a gain selection signal indicating respective conversion gains for reading pixel values of the frame from individual ones of the pixels in a local region of the pixel array, including a high conversion gain (HCG) and a low conversion gain (LCG);
readout logic for a group of pixels configured to:
receive the gain selection signal from the regional gain control circuit indicating the respective conversion gains for reading the pixel values of the frame from the individual ones of the pixels in the group of pixels;
wherein the regional gain control circuit is configured to:
read at least one first pixel value of the frame from one or more pixels in the local region of the pixel array with the HCG as indicated by the asserted gain selection signal;
assert, after the read of the at least one first pixel value, LCG for the gain selection signal for readout of pixel values of the frame from remaining pixels in the local region of the pixel array in response to determining that the at least one first pixel value satisfies a threshold;
assert, after the read of the at least one first pixel value, HCG for the gain selection signal for readout of pixel values of the frame from the remaining pixels in the local region of the pixel array in response to determining that the at least one first pixel value fails to satisfy the threshold;
and
output the pixel values of the frame via an output interface of the image sensor.

9 more elements

A camera, comprising:

one or more lenses configured to receive light;
an image sensor comprising:
a plurality of photodiodes that implement pixels in a pixel array, configured to capture a frame according to the light;
a regional gain control circuit asserting a gain selection signal indicating respective conversion gains for reading pixel values of the frame from individual ones of the pixels in a local region of the pixel array, including a high conversion gain (HCG) and a low conversion gain (LCG);
readout logic for a group of pixels configured to:
receive the gain selection signal from the regional gain control circuit indicating the respective conversion gains for reading the pixel values of the frame from the individual ones of the pixels in the group of pixels;
wherein the regional gain control circuit is configured to:
read at least one first pixel value of the frame from one or more pixels in the local region of the pixel array with the HCG as indicated by the asserted gain selection signal;
assert, after the read of the at least one first pixel value, LCG or HCG for the gain selection signal for readout of individual pixel values of the frame from remaining pixels in the group of pixels according to a pixel gain configuration pattern, the pixel gain configuration pattern being determined based on the at least one first pixel value;
and
output the pixel values of the frame via an output interface of the image sensor.

8 more elements

Dependencies are inferred from the claim text.

Facts

Application: 19/012,742Filed 7 Jan 2025 · continuation
Priority: 11 Oct 2021
Published: US 2025/0150736 A18 May 2025
Granted: 25 Aug 2026
Term ends: Not estimatedThe source records don’t support an estimate.

Classification7 codes

H04N 25/78
Addressed sensors, e.g. MOS or CMOS sensors: readout circuits for addressed sensors, e.g. output amplifiers or A/D converters
H04N 23/76
Circuitry for compensating brightness variation in the scene: by influencing the image signals
H04N 25/11
For transforming different wavelengths into image signals: arrangement of colour filter arrays [CFA]; Filter mosaics
H04N 25/51
Control of the SSIS exposure: control of the gain

Family

Application63/254,219Us provisional application · filed 11 Oct 2021
Application18/045,639Parent of this continuation · filed 11 Oct 2022
US 2025/0150736 A1Pre-grant publication · published 8 May 2025
US 12,225,315 B2Parent of this continuation
US 2023/0112586 A1Published application
US 12,720,237 B2This patent

From the US filing history. Foreign family members aren’t listed.