Image Sensor Light Shielding Region for Noise Offset Compensation

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Image sensors face challenges in accurately measuring light quantity due to variations in noise or offset values caused by temperature distributions on the light receiving surface, especially when the measurement pixel is distant from the optical black region.

Innovation Solution

The image sensor is sectioned into a measurement region and a light shielding region, with the light shielding region used to calculate and subtract noise or offset components, allowing for accurate light quantity measurement irrespective of pixel position. The light shielding regions are strategically placed based on temperature gradients in one, two, or three dimensions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Area of stationary object

If the measurement pixel is positioned far from the optical black region to increase measurement area, then the measurement region can be expanded, but the noise or offset variation increases due to temperature distribution, degrading measurement precision

Engineering Contradiction:

Improvemeasurement region areaVSAvoidlight quantity measurement accuracy

Core Design Contradiction:

Area of stationary objectVSMeasurement precision

Solution Approach 1:

The patent divides the effective pixel region into multiple measurement regions and introduces separate light shielding regions positioned adjacent to each measurement region. This segmentation allows each measurement region to have its own nearby reference pixels for noise/offset correction, enabling accurate measurement across the entire sensor area without requiring all measurement pixels to be close to a single optical black region.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent introduces light shielding regions as intermediary structures between the measurement regions and the optical black region. These light shielding regions contain reference pixels that are positioned close to measurement pixels, serving as local mediators for noise and offset correction. This intermediary structure enables accurate correction without requiring direct adjacency to the main optical black region.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Measurement precision

If the measurement pixel is positioned close to the optical black region to reduce noise or offset variation, then measurement precision is improved, but the available measurement area is reduced

Engineering Contradiction:

Improvelight quantity measurement accuracyVSAvoidmeasurement region area

Core Design Contradiction:

Measurement precisionVSArea of stationary object

Solution Approach 1:

The patent segments the sensor into multiple measurement regions, each with its own adjacent light shielding region containing reference pixels. This segmentation allows the sensor to achieve high measurement precision in multiple distributed locations simultaneously, effectively increasing the total measurement area while maintaining accuracy in each region.

Inventive Principle:

Principle #1Segmentation

3Device complexity

If a single optical black region is used for noise or offset correction across the entire sensor, then the device structure is simplified, but measurement precision degrades in regions distant from the optical black region due to temperature gradients

Engineering Contradiction:

Improvesensor structure complexityVSAvoidlight quantity measurement accuracy

Core Design Contradiction:

Device complexityVSMeasurement precision

Solution Approach 1:

The patent divides the correction function into multiple segments by creating separate light shielding regions adjacent to different measurement regions. Each light shielding region provides local reference pixels for correction, maintaining temperature similarity with nearby measurement pixels. This segmented approach improves measurement precision across the entire sensor while adding only moderate structural complexity.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent applies local quality by providing different correction references for different regions of the sensor. Each measurement region has its own adjacent light shielding region with reference pixels that match the local temperature conditions. This localised approach ensures that correction is appropriate for each region's specific thermal environment, improving overall measurement precision.

Inventive Principle:

Principle #3Local quality

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 solution enables precise measurement of light quantity with desirable accuracy across the entire light receiving surface, even with temperature distributions, by effectively compensating for noise and offset variations.

Implementation Method 1

an optical black region formed of a pixel group which is shielded from light... a light shielding region which is used for a calculation of a value of one of an offset component and a noise component and is shielded from light

Methodology Applied

Scientific EffectLight shielding: Absorption (EM radiation)

Data Source

PatentUS9111825B2Image sensor, light quantity measurement method, and microscope system

Publication Date: 2015.08.18 SONY GROUP CORP

AI summary

An image sensor includes an effective pixel region formed of a pixel group which is irradiated with light, and an optical black region formed of a pixel group which is shielded from light. In the image sensor, when the image sensor is used for a light quantity measurement, the effective pixel region is sectioned into a measurement region used for the light quantity measurement and a light shielding region which is used for a calculation of a value of one of an offset component and a noise component and is shielded from light.