CMOS Image Sensor Pixel Block Segmentation for Phase Detection
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In solid-state image pickup elements using the area ADC system, the timing differences between exposure and reading for pixels can lead to inefficiencies in phase difference detection AF, as the arrangement of pixels for phase difference detection is not adequately considered.
Innovation Solution
A solid-state image pickup element with a pixel array partitioned into blocks, including both normal pixels and phase difference detection pixels, where the AD conversion and reading control are coordinated to ensure accurate and efficient phase difference detection by arranging phase difference detection pixels in corresponding positions across blocks, allowing for flexible AD conversion orders and shared AD conversion resources.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the area ADC system is adopted to reduce timing differences between exposure and reading, then the reading speed is improved, but the phase difference detection accuracy deteriorates because the arrangement of pixels for phase difference detection is not considered
Solution Approach 1:
The pixel array is divided into multiple pixel blocks, with each block containing pixels for phase difference detection at corresponding positions. The ADC conversion is performed in units of these pixel blocks, allowing simultaneous conversion of corresponding pixels across different blocks while maintaining timing synchronization for phase difference detection.
Solution Approach 2:
Within each pixel block, pixels for phase difference detection are arranged at specific corresponding positions to enable directional phase difference detection. The local arrangement within blocks ensures that pixels used for phase difference detection have synchronized timing, while other pixels can be processed independently.
2Device complexity
If pixels are processed sequentially by column ADC system, then the device complexity is reduced, but the reading time increases causing timing shifts between different rows
Solution Approach 1:
The pixel array is segmented into multiple pixel blocks that can be processed in parallel. Each pixel block is handled by a shared ADC through time-multiplexed conversion, allowing multiple blocks to be processed simultaneously while using fewer ADC resources, thus reducing overall device complexity while improving reading speed.
Solution Approach 2:
The ADC converts pixel signals from different pixel blocks in a periodic sequence, allocating specific time slots to each block. This periodic conversion approach allows efficient utilization of shared ADC resources while maintaining synchronized timing for pixels used in phase difference detection.
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 enables precise and efficient phase difference detection in arbitrary directions, enhancing the accuracy and speed of auto focus operations.
Implementation Method 1
a photoelectric conversion portion (PD) 75 that converts the incident light into electric charges
Data Source
AI summary
The present disclosure relates to a solid-state image pickup element and an electronic apparatus each of which enables a phase difference in an arbitrary direction to be properly detected.A solid-state image pickup element as a first aspect of the present disclosure includes a pixel array, and a plurality of AD conversion portions. The pixel array is partitioned into a plurality of pixel blocks each including a normal pixel and a pixel for phase difference detection. The plurality of AD conversion portions correspond to the respective plurality of pixel blocks, and AD-convert pixel signals based on a plurality of pixels included in the corresponding pixel block. In this case, the pixel for phase difference detection included in one pixel block of the plurality of pixel blocks, and the pixel for phase difference detection included in the other pixel block of the plurality of pixel blocks are arranged in positions corresponding to each other. The present disclosure, for example, can be applied to a CMOS image sensor.