Divisional Pixel Signal Processing for Autofocus Accuracy

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Solution Overview

Problem

Current image processing devices for image sensors with multiple photoelectric conversion elements per pixel face challenges in efficiently processing and utilizing the phase difference information from divisional pixel signals, which affects autofocus accuracy and image quality.

Innovation Solution

An image processing device with a Bayer layout of color filters, microlenses, and photoelectric conversion elements that generates Bayer-type divisional image data from divisional pixel signals, allowing for advanced image processing and phase difference detection, including low-light shading correction and phase difference autofocus.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If multiple photoelectric conversion elements are provided per pixel to detect phase difference information, then autofocus accuracy is improved, but device complexity increases

Engineering Contradiction:
Improvephase difference detection accuracyVSAvoidphotoelectric conversion element arrangement
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The pixel is divided into multiple photoelectric conversion elements (first, second, third, and fourth photoelectric conversion elements) arranged in a specific pattern. Each element captures light from different directions, enabling phase difference detection through segmentation of the pixel structure.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Different photoelectric conversion elements are positioned to receive light from specific directions (e.g., first and second elements for one direction, third and fourth for another direction). This local specialization allows efficient phase difference measurement while maintaining manageable complexity.

Inventive Principle:
Principle #3Local quality

2Manufacturing precision

If multiple divisional pixel signals are processed to generate Bayer-type divisional image data, then image quality is improved, but processing complexity increases

Engineering Contradiction:
Improveimage qualityVSAvoidimage processing circuit complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The image processing separates divisional pixel signals into different Bayer-type divisional image data groups based on their directional characteristics. This segmentation allows independent processing of each group, simplifying the overall processing complexity while maintaining high image quality.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The processing circuit performs selective processing on divisional pixel signals, focusing computational resources on generating specific Bayer-type divisional image data that is most critical for image quality, rather than processing all signals equally.

Inventive Principle:
Principle #16Partial or excessive action

3Illumination intensity

If advanced image processing is performed on divisional image data, then low-light performance is improved, but processing time increases

Engineering Contradiction:
Improvelow-light performanceVSAvoidprocessing time
Core Design Contradiction:
Illumination intensityVSLoss of time

Solution Approach 1:

The image processing circuit performs preliminary processing on divisional pixel signals to generate Bayer-type divisional image data in advance, organizing the data structure optimally before final image generation. This preliminary organization reduces processing time during low-light conditions when speed is critical.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The processing adapts parameters based on lighting conditions, adjusting the processing intensity and methods for divisional image data. In low-light conditions, optimized parameter settings enable effective processing with reduced time loss.

Inventive Principle:
Principle #35Parameter changes

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

Enhances autofocus accuracy and image quality by effectively processing divisional pixel signals, improving phase difference detection and low-light performance while maintaining high frame rates.

Implementation Method 1

photoelectric conversion elements of m×n which generate divisional pixel signals of m×n respectively

Methodology Applied
Scientific EffectPhotoelectric effect: Photoelectric Effect

Data Source

PatentUS11064143B2Image processing device and image pickup apparatus for processing divisional pixal signals to generate divisional image data
Publication Date: 2021.07.13 OLYMPUS CORPORATION(JP)
  • US11064143B2 patent drawing
  • US11064143B2 patent drawing
  • US11064143B2 patent drawing

AI summary

An image processing device includes an image data generation circuit configured to generate n pieces of Bayer-type divisional image data configured by divisional pixel signals having the same divisional arrangement from divisional pixel signals of m×n generated by photoelectric conversion elements at n parts into which each of m pixels is divided, and an image processing circuit configured to perform image processing on the n pieces of Bayer-type divisional image data.