Image Sensor Pixel Addition Circuit for Phase Difference AF
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Solution Overview
Problem
Existing image sensors face compatibility issues between pixel addition for reduced pixel output and phase difference AF, leading to complex circuitry and increased power consumption for phase difference data generation.
Innovation Solution
An image sensor with paired first and second pixel sections and a pixel signal generation circuit that alternates pixel addition signals between frames to enable phase difference detection while maintaining image data generation with a simple structure, reducing power consumption.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If pixel addition is performed to reduce the number of output pixels for through image display and movie shooting, then power consumption and image processing load are reduced, but phase difference AF becomes impossible
Solution Approach 1:
The photodiodes are segmented into first and second pixel sections, allowing the image sensor to perform pixel addition on one set while preserving the other set for phase difference AF detection. This segmentation enables the system to reduce power consumption through pixel addition while maintaining autofocus capability.
Solution Approach 2:
The patent implements periodic switching between different pixel section usage patterns. In odd frames, first pixel sections are used for image data while second pixel sections capture phase difference information. In even frames, the roles are reversed. This periodic action allows both functions to operate at different times without requiring simultaneous complex circuitry.
2Adaptability or versatility
If the image sensor generates both phase difference data and two sets of image data simultaneously, then both AF and through image display functions are available, but circuit structure becomes complicated and power consumption increases
Solution Approach 1:
The patent employs periodic switching between different pixel section configurations across consecutive frames. Odd frames use first pixel sections for image data and second pixel sections for phase difference data, while even frames reverse this assignment. This temporal multiplexing allows dual functionality without requiring complex simultaneous processing circuits.
Solution Approach 2:
The system dynamically switches the functional assignment of pixel sections between frames. The pixel signal generation circuit alternates which pixel sections contribute to image data and which contribute to phase difference data, creating a flexible, adaptive system that achieves dual functionality through temporal variation rather than static complex circuitry.
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
The solution allows for efficient phase difference AF and improved speed of image/movie display/storage without increasing power consumption, by alternating pixel addition signals and using paired pixel sections for phase difference detection.
Implementation Method 1
paired first pixel sections and second pixel sections that are arranged in correspondence with the respective micro-lenses
Data Source
AI summary
An image sensor, comprising pixels that have paired first pixel sections and second pixel sections, and a pixel signal generation circuit that repeatedly outputs an pixel signal, wherein the pixel signal generation circuit in a first frame among image frames, adds pixel signals of the first pixel sections corresponding to a first column to generate a first pixel addition signal, adds pixel signals of the second pixel sections corresponding to a second column to generate a second pixel addition signal, and respectively outputs the first and second pixel addition signals, and in a second frame that is continuous to the first frame, adds outputs of the second pixel section corresponding to the first column to generate a third pixel addition signal, adds outputs of the first pixel section corresponding to the second column to generate a fourth pixel addition signal, and respectively outputs the third and fourth pixel addition signals.