Sub-Pixel Image Sensor Layout for Accurate Distance Detection

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Current image sensing devices face challenges in efficiently discriminating detection signals between adjacent sub-pixels, leading to signal interference and reduced electron transfer efficiency, which affects their ability to accurately measure distance to target objects.

Innovation Solution

The image sensing device incorporates a structure with isolation portions surrounding unit pixels and a voltage applying region at the center, featuring doped regions with different depths and doping densities, and demodulation control signals with phase differences to improve electron detection and reduce signal interference between sub-pixels.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Area of moving object

If sub-pixels are disposed close to each other to increase pixel density, then the area coverage and resolution are improved, but signal interference between adjacent sub-pixels increases and detection precision deteriorates

Engineering Contradiction:

Improvepixel densityVSAvoidsignal discrimination accuracy

Core Design Contradiction:

Area of moving objectVSMeasurement precision

Solution Approach 1:

The patent divides the pixel structure into multiple sub-pixels (first, second, third, and fourth sub-pixels) within each pixel unit, with isolation portions strategically placed between them. This segmentation allows close proximity for high density while maintaining signal discrimination through the isolation structure.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent applies different doping densities to different isolation portions (first isolation portion with first doping density, second isolation portion with second doping density). This local quality variation optimizes signal isolation at specific locations where interference is most critical, improving detection precision without reducing pixel density.

Inventive Principle:

Principle #3Local quality

2Measurement precision

If isolation portions are added between sub-pixels to reduce signal interference, then detection precision is improved, but device complexity and manufacturing difficulty increase

Engineering Contradiction:

Improvesignal discrimination accuracyVSAvoidisolation structure complexity

Core Design Contradiction:

Measurement precisionVSDevice complexity

Solution Approach 1:

The patent optimizes the doping density parameter of the isolation portions to achieve effective signal isolation. By carefully selecting and controlling the doping density values, the patent reduces signal interference between sub-pixels while avoiding the need for overly complex isolation structures.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The isolation portions serve multiple functions simultaneously: they electrically isolate adjacent sub-pixels to prevent signal interference, and their doping structure also influences charge carrier distribution and collection efficiency. This multi-functionality reduces the need for additional separate isolation components.

Inventive Principle:

Principle #6Universality (Multi-functionality)

3Measurement precision

If demodulation control signals with phase differences are applied to control electron movement, then distance measurement accuracy is improved, but energy consumption and operational complexity increase

Engineering Contradiction:

Improvedistance measurement accuracyVSAvoidpower consumption

Core Design Contradiction:

Measurement precisionVSUse of energy by moving object

Solution Approach 1:

The patent employs periodic demodulation control signals with specific phase differences applied to the sub-pixels. This periodic modulation enables accurate distance measurement through phase comparison while allowing the system to enter low-power states between modulation cycles, optimizing energy efficiency.

Inventive Principle:

Principle #19Periodic action

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 configuration enhances electron detection efficiency and reduces signal interference, enabling more accurate distance measurement to target objects by optimizing signal processing and electron transfer within the device.

Implementation Method 1

a control region formed to generate a current within a substrate in which the sub-pixels are disposed

Methodology Applied

Scientific EffectElectrical Conduction: Conduction (electrical)

Implementation Method 2

a detection region formed to capture electrons moving by the current

Methodology Applied

Scientific EffectElectron Detection:

Implementation Method 3

converting light into electrical signals using a photosensitive semiconductor material which reacts to light

Methodology Applied

Scientific EffectPhotoelectric Effect: Photoelectric Effect

Data Source

PatentUS12113085B2Image sensing device

Publication Date: 2024.10.08 SK HYNIX INC

AI summary

An image sensing device includes a plurality of unit pixels, each of which includes a plurality of sub-pixels. Each of the unit pixels is structured to respond to incident light to produce photocharges indicative of detected incident light and includes sub-pixels. Each sub-pixel includes a control region configured to generate, within a substrate in which the sub-pixels are disposed, a current that carries the photocharges, a detection region spaced from the control region and configured to capture the photocharges carried by the current, a plurality of first isolation portions disposed between two adjacent sub-pixels, a second isolation portion disposed to surround the sub-pixels, and a voltage applying region disposed at a center portion of the unit pixel and configured to receive a first voltage.