Multi-Die Digital Pixel Image Sensor for Noise-Resistant Signal Transfer

Solution Overview

Problem

Conventional image sensors using analog pixels face issues with noise and coupling during signal transmission, leading to reduced image quality, especially when processing high-resolution images.

Innovation Solution

The implementation of a digital pixel structure within an image sensor device, comprising a photo detector, comparator, and memory circuit, with a pixel driver and digital logic circuit distributed across multiple semiconductor dies to process and transmit digital signals, reducing noise and coupling.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If analog pixels are used to output analog signals, then the image sensor can process light signals, but the analog signals are vulnerable to noise and coupling during transmission

Engineering Contradiction:

Improvesignal transmission reliabilityVSAvoidnoise and coupling

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The image sensor is divided into multiple semiconductor dies, with each die containing specific pixel arrays and associated circuits. This segmentation allows analog-to-digital conversion to occur at the pixel level within each die, converting signals to digital format before transmission, thereby eliminating noise and coupling issues during signal transmission between dies.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

An analog-to-digital converter is introduced as an intermediary component within each pixel array die, converting analog pixel signals to digital signals before they are transmitted to other dies. This intermediary conversion process eliminates the vulnerability of analog signals to noise and coupling during transmission.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Device complexity

If all components are integrated into a single semiconductor die, then the device structure is simplified, but the processing of high-resolution image signals becomes problematic due to noise

Engineering Contradiction:

Improvedevice structureVSAvoidhigh-resolution signal processing

Core Design Contradiction:

Device complexityVSReliability

Solution Approach 1:

The image sensor is divided into multiple semiconductor dies, with each die containing specific pixel arrays and associated circuits. This segmentation allows analog-to-digital conversion to occur at the pixel level within each die, converting signals to digital format before transmission, thereby eliminating noise and coupling issues during signal transmission between dies.

Inventive Principle:

Principle #1Segmentation

3Device complexity

If analog signals are transmitted between pixels and processing circuits, then the device can function with fewer components, but the analog signals are vulnerable to noise and coupling

Engineering Contradiction:

Improvenumber of componentsVSAvoidnoise and coupling

Core Design Contradiction:

Device complexityVSObject-affected harmful factors

Solution Approach 1:

An analog-to-digital converter is introduced as an intermediary component within each pixel array die, converting analog pixel signals to digital signals before they are transmitted to other dies. This intermediary conversion process eliminates the vulnerability of analog signals to noise and coupling during transmission.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent replaces the mechanical/electrical transmission of analog signals with digital signal transmission. By converting analog signals to digital signals at the pixel level, the system substitutes the vulnerable analog transmission mechanism with a robust digital transmission mechanism that is immune to noise and coupling.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

4Reliability

If digital signal processing is performed at the pixel level, then noise and coupling are minimized, but the device structure becomes more complex with multiple semiconductor dies

Engineering Contradiction:

Improvesignal qualityVSAvoidmulti-die structure

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The image sensor is divided into multiple semiconductor dies, with each die containing specific pixel arrays and associated circuits. This segmentation allows analog-to-digital conversion to occur at the pixel level within each die, converting signals to digital format before transmission, thereby eliminating noise and coupling issues during signal transmission between dies.

Inventive Principle:

Principle #1Segmentation

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

This approach enhances image sensor performance by directly generating digital signals at the pixel level, minimizing noise and enabling faster image processing, thereby improving image quality and reliability.

Implementation Method 1

An image sensor may convert a light signal into an electrical signal

Methodology Applied

Scientific EffectPhotoelectric effect: Photoelectric Effect

Data Source

PatentUS12176362B2Image sensor device

Publication Date: 2024.12.24 SAMSUNG ELECTRONICS CO LTD

AI summary

An image sensor device includes a digital pixel that includes a photo detector, a comparator, and a memory circuit, a pixel driver that controls the digital pixel, and a digital logic circuit that performs a digital signal processing operation on a digital signal output from the digital pixel. The photo detector and a first portion of the comparator are formed in a first semiconductor die, a second portion of the comparator, the memory circuit, and the pixel driver are formed in a second semiconductor die under the first semiconductor die, and the digital logic circuit is formed in a third semiconductor die under the second semiconductor die.