Image Sensor Crosstalk Layout for Phase Difference Focus Detection
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Solution Overview
Problem
Existing image sensors face challenges in maintaining focus detection accuracy due to differences in readout timing between the main scanning and sub-scanning directions, which affects the performance of phase difference focus detection.
Innovation Solution
The image sensor is designed with a matrix arrangement of microlenses and photoelectric conversion portions, where the electric charge crosstalk rate between photoelectric conversion portions in the main scanning direction is higher than in the sub-scanning direction, and a readout unit implemented by processors or circuitry to sequentially read out signals.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If pixels in each row are read out at the same timing in sequential row-by-row basis, then readout efficiency is improved, but the difference in readout timing of different rows becomes greater the further apart the rows are, affecting focus detection accuracy
Solution Approach 1:
The patent applies parameter changes by adjusting the electric charge crosstalk rate parameter based on the readout timing characteristics of different directions. Since sequential row-by-row readout inherently creates larger timing differences for rows further apart, the patent compensates by setting a lower electric charge crosstalk rate for photoelectric conversion portions in the sub-scanning direction. This parameter adjustment balances the focus detection accuracy across both directions despite the efficiency-optimized sequential readout pattern.
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 configuration brings the focus detection performance in the main scanning and sub-scanning directions closer to each other, improving the accuracy of phase difference focus detection by optimizing the electric charge crosstalk rates and readout timing differences.
Implementation Method 1
a plurality of photoelectric conversion portions, provided for each microlens of at least some of the plurality of microlenses, perform photoelectric conversion on light that has entered the photoelectric conversion portions via the respective microlens
Data Source
AI summary
A plurality of microlenses arranged in a matrix in first and second directions orthogonal to each other; a plurality of photoelectric conversion portions, provided for each microlens of at least some of the plurality of microlenses, that perform photoelectric conversion on light that has entered the photoelectric conversion portions via the respective microlens; and a readout unit that sequentially reads out signals from the plurality of photoelectric conversion units with the first direction being a main scanning direction and the second direction being a sub-scanning direction are provided. The plurality of photoelectric conversion portions are arranged in at least one of the first and second directions, and an electric charge crosstalk rate between a plurality of photoelectric conversion portions arranged in the first direction is higher than an electric charge crosstalk rate between a plurality of photoelectric conversion portions arranged in the second direction.