Image Sensor Dual Scanning Phase Difference Lines
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Solution Overview
Problem
Existing image processing systems in imaging apparatuses face challenges in shortening the time from the start of imaging to the end of the image process or phase difference detection process, as they often need to read unnecessary pixels, delaying the start of image or phase difference detection.
Innovation Solution
The system employs a dual scanning mechanism where phase difference lines and normal lines are scanned separately, with pixel values from normal pixels output in one period and phase difference pixels in another, using a row scanning section and column scanning section to manage and output these values efficiently, including concurrent driving and holding of pixel values and adding fixed values when necessary.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of time
If all pixels are read out to ensure complete image data, then image quality is maintained, but processing time increases
Solution Approach 1:
The pixel array is divided into two distinct groups: phase difference pixels for focus detection and normal pixels for image capture. The readout process is segmented into two separate operations - first reading normal pixels to enable image processing, then reading phase difference pixels for focus detection. This segmentation allows independent optimization of each readout path and eliminates the bottleneck of reading all pixels sequentially.
2Measurement precision
If phase difference pixels are read out for focus detection, then focusing accuracy is improved, but image processing is delayed
Solution Approach 1:
The normal pixels are read out and processed before the phase difference pixels are read out. This preliminary action allows the image processing to start earlier and complete before focus detection begins, ensuring that image processing is not delayed by the subsequent phase difference pixel readout. The focus detection can then proceed independently using the pre-read phase difference pixels.
3Productivity
If normal pixels are read out for image processing, then image output is improved, but phase difference detection is delayed
Solution Approach 1:
The readout process is divided into two independent phases: first phase reads out normal pixels for image processing, second phase reads out phase difference pixels for focus detection. This segmentation allows both processes to proceed independently without blocking each other, eliminating the delay that would occur if all pixels were read sequentially.
4Loss of time
If all lines are scanned for complete pixel data, then data completeness is ensured, but scanning time increases
Solution Approach 1:
The patent extracts and processes normal pixels separately from phase difference pixels. By taking out the normal pixels for dedicated image processing, the system can complete image output faster without needing to wait for the complete scanning of all lines including phase difference lines. The phase difference pixels are processed independently afterward.
Data Source
AI summary
There is provided an image sensor, including a plurality of phase difference lines in which a plurality of pixels including phase difference pixels for detecting a phase difference are arranged, a plurality of normal lines in which a plurality of normal pixels not including the phase difference pixels are arranged, a row scanning section which selects each of the plurality of phase difference lines and each of the plurality of normal lines within a first period, and selects each of the plurality of phase difference lines within a second period different from the first period, and a column scanning section which outputs pixel values of the plurality of normal pixels in each of the lines selected within the first period, and outputs pixel values of the phase difference pixels in each of the lines selected within the second period.