Image Sensor Micro Lens Array Autofocus Optimization

Solution Overview

Problem

Image sensors with phase detection autofocus (PDAF) often have lower autofocus performance at the peripheral regions due to inadequate separation of incident light angles, which affects image quality and focusing speed.

Innovation Solution

The image sensor employs a micro lens array with micro lenses of different sizes in various regions, allowing for improved separation of incident light angles and enhanced autofocus performance across the entire image area, including the peripheral regions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a micro lens array with uniform lens sizes is used in the image sensor, then the manufacturing process is simple and consistent, but the autofocus performance in peripheral regions is poor due to inadequate light angle separation

Engineering Contradiction:

Improveautofocus performanceVSAvoidmicro lens array structure

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent applies local quality by configuring micro lenses with different sizes at different locations within the pixel array. Specifically, micro lenses in peripheral regions have different sizes compared to those in central regions, allowing each region to be optimized for its specific optical requirements. This enables improved light angle separation and autofocus performance in peripheral areas without compromising the overall system.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The patent segments the pixel array into multiple regions (e.g., first region, second region, third region) with different micro lens size configurations. This segmentation allows independent optimization of each region's micro lenses to handle different incident light angles, thereby improving overall autofocus performance across the entire image sensor while maintaining manageable manufacturing complexity through systematic regional differentiation.

Inventive Principle:

Principle #1Segmentation

2Reliability

If larger micro lenses are used in peripheral regions to enhance light angle separation, then autofocus performance improves, but manufacturing precision requirements increase

Engineering Contradiction:

Improveautofocus performanceVSAvoidmicro lens size consistency

Core Design Contradiction:

ReliabilityVSManufacturing precision

Solution Approach 1:

The patent implements local quality by assigning different micro lens sizes to different spatial regions within the pixel array. Peripheral regions utilize micro lenses with sizes optimized for capturing and separating oblique incident light angles, while central regions use different sizes appropriate for their optical characteristics. This regional differentiation improves autofocus performance across the entire sensor while allowing manufacturing processes to target specific size ranges for each region, thereby managing precision requirements more effectively.

Inventive Principle:

Principle #3Local quality

3Measurement precision

If micro lenses of different sizes are implemented across the pixel array, then light angle separation is improved for better autofocus, but the device structure becomes more complex

Engineering Contradiction:

Improvelight angle separationVSAvoidmicro lens array configuration

Core Design Contradiction:

Measurement precisionVSDevice complexity

Solution Approach 1:

The patent applies local quality by configuring micro lenses with different sizes at different locations within the pixel array. Specifically, micro lenses in peripheral regions have different sizes compared to those in central regions, allowing each region to be optimized for its specific optical requirements. This enables improved light angle separation and autofocus performance in peripheral areas without compromising the overall system.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The patent segments the pixel array into multiple regions (e.g., first region, second region, third region) with different micro lens size configurations. This segmentation allows independent optimization of each region's micro lenses to handle different incident light angles, thereby improving overall autofocus performance across the entire image sensor while maintaining manageable manufacturing complexity through systematic regional differentiation.

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 solution enhances autofocus accuracy and speed by more effectively separating light angles at the peripheral regions, leading to improved image sharpness and faster focusing capabilities.

Implementation Method 1

a module lens configured to receive a first light incident at a first angle that is refracted from an external object and a second light incident at a second angle that is refracted from the object

Methodology Applied

Scientific EffectRefraction: Refraction

Data Source

PatentUS11563883B2Image sensor and electronic device including image sensor

Publication Date: 2023.01.24 SAMSUNG ELECTRONICS CO LTD

AI summary

Provided is an image sensor including a pixel array including a plurality of pixels, and a micro lens array including a first micro lens of a first size provided in a first area of the pixel array and a second micro lens of a second size provided in a second area of the pixel array, the second size being different from the first size.