Pixel Structure for HDR Imaging and Phase Difference Detection

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Solution Overview

Problem

Existing solid-state imaging devices face challenges in simultaneously achieving high dynamic range image generation and phase difference detection due to the trade-off between lens curvature for phase difference characteristics and HDR image quality, and the sensitivity of lens structures to shape variations, making it difficult to produce in large quantities.

Innovation Solution

A solid-state imaging device with a pixel structure that includes two photodiodes per pixel, shared pixel transistors, and on-chip lenses, allowing for simultaneous acquisition of high dynamic range images and phase difference signals by adjusting exposure times and using inter-pixel light-shielding films to optimize image capture.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If the curvature of the on-chip lens is increased to increase the refractive power, then phase difference detection capability is improved, but HDR image generation capability deteriorates

Engineering Contradiction:
Improvephase difference detection capabilityVSAvoidHDR image generation capability
Core Design Contradiction:
Measurement precisionVSManufacturing precision

Solution Approach 1:

The on-chip lens is divided into multiple regions with different curvatures: a first region with a first curvature optimized for phase difference detection and a second region with a second curvature optimized for HDR image generation. This segmentation allows each region to independently optimize its function without compromising the other.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Different regions of the on-chip lens are assigned different local optical properties (curvatures) to perform different functions. The first region has higher curvature for phase difference detection while the second region has lower curvature for HDR imaging, allowing each local area to have the quality needed for its specific purpose.

Inventive Principle:
Principle #3Local quality

2Manufacturing precision

If the curvature of the on-chip lens is reduced to reduce the refractive power, then HDR image generation capability is improved, but phase difference detection capability deteriorates

Engineering Contradiction:
ImproveHDR image generation capabilityVSAvoidphase difference detection capability
Core Design Contradiction:
Manufacturing precisionVSMeasurement precision

Solution Approach 1:

The on-chip lens is divided into multiple regions with different curvatures: a first region with a first curvature optimized for phase difference detection and a second region with a second curvature optimized for HDR image generation. This segmentation allows each region to independently optimize its function without compromising the other.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Different regions of the on-chip lens are assigned different local optical properties (curvatures) to perform different functions. The first region has higher curvature for phase difference detection while the second region has lower curvature for HDR imaging, allowing each local area to have the quality needed for its specific purpose.

Inventive Principle:
Principle #3Local quality

3Manufacturing precision

If a lens structure with variable curvature is used to achieve both phase difference and HDR characteristics, then imaging performance is improved, but manufacturing complexity and sensitivity to shape variation increase

Engineering Contradiction:
Improveimaging performanceVSAvoidproduction feasibility
Core Design Contradiction:
Manufacturing precisionVSEase of manufacture

Solution Approach 1:

Instead of using a complex continuously variable curvature lens, the patent segments the lens into discrete regions with fixed curvatures. This simplifies manufacturing by allowing each region to be formed using standard photolithography and reflow processes, reducing sensitivity to shape variations while maintaining dual functionality.

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

Enables the simultaneous acquisition of high dynamic range images and phase difference signals, improving image quality and autofocus capabilities while maintaining production feasibility.

Implementation Method 1

a light receiving element that generates electric charge by performing photoelectric conversion

Methodology Applied
Scientific EffectPhotoelectric conversion: Photoelectric Effect

Data Source

PatentEP4080880B1Solid-state imaging device and electronic apparatus
Publication Date: 2024.08.14 SONY SEMICON SOLUTIONS CORP
  • EP4080880B1 patent drawingFigure 1
  • EP4080880B1 patent drawingFigure 2
  • EP4080880B1 patent drawingFigure 3

AI summary

The present technology relates to a solid-state imaging device and an electronic apparatus that enable simultaneous acquisition of a signal for generating a high dynamic range image and a signal for detecting a phase difference. The solid-state imaging device includes a plurality of pixel sets each including color filters of the same color, for a plurality of colors, each pixel set including a plurality of pixels. Each pixel includes a plurality of photodiodes PD. The present technology can be applied, for example, to a solid-state imaging device that generates a high dynamic range image and detects a phase difference, and the like.