US 12,323,718 B2Granted

Image sensor, method of operating the image sensor, and image processing device

AssigneeSamsung Electronics Co., Ltd.

InventorEunsub Shim

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Abstract

An image sensor includes a pixel array, an analog-to-digital conversion circuit, and an image signal processor. A pixel of the pixel array generates a first analog signal based on a quantity of charge accumulated during a first exposure time and generate a second analog signal based on a quantity of charge accumulated during a shorter second exposure time. The analog-to-digital conversion circuit may generate a first digital signal based on the first analog signal and a first ramp signal and may generate a second digital signal based on the second analog signal and a second ramp signal. The image signal processor may generate image data based on the first and second digital signals. The first ramp signal may be different from the second ramp signal in terms of at least one of a ramping time or a ramping start voltage level.

Claims20

Dependent claims

An image sensor, comprising:

a pixel array including a plurality of pixels;
an analog-to-digital conversion circuit configured to receive an analog signal from the plurality of pixels and transmit a digital signal;
and
an image signal processor configured to receive the digital signal and generate image data,
wherein at least one pixel of the plurality of pixels is configured to
generate a first analog signal based on a first quantity of charge accumulated at the at least one pixel during a first exposure time, and
generate a second analog signal based on a second quantity of charge accumulated at the at least one pixel during a second exposure time that is shorter than the first exposure time,
wherein the analog-to-digital conversion circuit is further configured to
generate a first digital signal based on the first analog signal and a first ramp signal, and
generate a second digital signal based on the second analog signal and a second ramp signal,
wherein the image signal processor is further configured to generate the image data based on the first digital signal and the second digital signal, and
wherein the first ramp signal is different from the second ramp signal such that at least one of a ramping time of the first ramp signal or a ramping start voltage level of the first ramp signal is different from a corresponding one of a ramping time of the second ramp signal or a ramping start voltage level of the second ramp signal.

9 more elements

A method of operating an image sensor, the method comprising:

accumulating a first photocharge packet in a photoelectric conversion device, in response to incident light during a first exposure time;
transmitting the first photocharge packet accumulated in the photoelectric conversion device to a floating diffusion node, in response to a first transmission control signal;
generating a first analog signal based on the first photocharge packet, which is accumulated in the floating diffusion node, and converting the first analog signal into a first digital signal;
resetting the floating diffusion node, in response to a reset control signal;
accumulating a second photocharge packet in the photoelectric conversion device, in response to incident light during a second exposure time that is shorter than the first exposure time;
transmitting the second photocharge packet accumulated in the photoelectric conversion device to the floating diffusion node, in response to a second transmission control signal;
and
generating a second analog signal based on the second photocharge packet, which is accumulated in the floating diffusion node, and converting the second analog signal into a second digital signal,
wherein the converting the first analog signal into the first digital signal includes performing analog-to-digital conversion on a linear signal of the first analog signal and a log signal of the first analog signal, and the converting the second analog signal into the second digital signal includes performing analog-to-digital conversion on only a linear signal of the second analog signal.

6 more elements

Dependencies are inferred from the claim text.

Facts

Application: 18/456,853Filed 28 Aug 2023
Priority: KR 10-2022-012975411 Oct 2022
Published: US 2024/0121526 A111 Apr 2024
Granted: 3 Jun 2025
Term ends: Not estimatedThe source records don’t support an estimate.

Classification16 codes

H04N 25/67
Noise processing, e.g. detecting, correcting, reducing or removing noise: applied to fixed-pattern noise, e.g. non-uniformity of response
H03M 1/0697
Using redundancy: in time, e.g. using additional comparison cycles
H03M 1/1235
Analogue/digital converters: non-linear conversion not otherwise provided for in subgroups of H03M1/12
H03M 1/56
With intermediate conversion to time interval: input signal compared with linear ramp