Image Sensor Parallel Readout for Focus and Capture Signals
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing image sensors with two photodiodes per pixel face challenges in simultaneous acquisition of focus detection and captured image signals, leading to increased readout time due to sequential signal processing, which is inefficient compared to sensors with a single photodiode per pixel.
Innovation Solution
An image sensor design that enables parallel readout of image capture and focus detection signals by incorporating first and second photoelectric conversion portions, with dedicated output portions for each, allowing simultaneous output of signals from these portions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If sequential readout of focus detection signal and captured image signal is used, then signal acquisition is simplified, but readout time significantly increases
Solution Approach 1:
The pixel array is divided into first pixel units with first photodiodes for focus detection and second pixel units with second photodiodes for captured image signals. This segmentation allows independent parallel readout paths, enabling simultaneous acquisition of both signal types without sequential processing delays
Solution Approach 2:
The patent introduces a spatial dimension by dividing pixels into different types (first and second pixel units) rather than using a single uniform pixel type. This dimensional differentiation enables parallel signal processing channels, transforming a time-sequential operation into a spatially-parallel operation
2Adaptability or versatility
If two photodiodes are provided per pixel for focus detection and image capture, then functional versatility is improved, but readout speed decreases due to sequential processing
Solution Approach 1:
The pixel array is segmented into first pixel units dedicated to focus detection and second pixel units dedicated to captured image signals. This segmentation enables independent parallel readout paths, allowing simultaneous acquisition of both signal types without sequential processing delays
Solution Approach 2:
The image sensor achieves multi-functionality by incorporating both first photodiodes for focus detection and second photodiodes for captured image signals within the same sensor structure. The controller manages both functions simultaneously through parallel readout, making the sensor universal for both autofocus and imaging operations
3Productivity
If combined signal readout is performed after first photodiode signal readout, then reset level signal usage is optimized, but simultaneous signal acquisition is prevented
Solution Approach 1:
The pixel array is divided into first pixel units with first photodiodes and second pixel units with second photodiodes. This segmentation creates independent readout paths that can operate simultaneously, allowing the sensor to acquire both focus detection signals and captured image signals at the same time without sequential processing
Solution Approach 2:
The sensor performs preliminary action by preparing separate readout paths for first and second photodiodes in advance. The controller is configured to simultaneously read out signals from both types of photodiodes, enabling concurrent signal acquisition without waiting for sequential processing to complete
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 design significantly reduces readout time, enabling high-speed acquisition of both focus detection and captured image signals, thus improving the frame rate for image capturing applications.
Implementation Method 1
each pixel unit having first and second photoelectric conversion portions
Data Source
AI summary
An image sensor, comprising a pixel region in which a plurality of pixel units are arranged, each pixel unit having first and second photoelectric conversion portions, a first output portion that outputs, outside of the image sensor, a first signal based on a signal from the first photoelectric conversion portion of the pixel units, and a second output portion that outputs a second signal based on a signal from the first photoelectric conversion portion and a signal from the second photoelectric conversion portion of the pixel units, wherein output of the first signal from the first output portion and output of the second signal from the second output portion are performed in parallel.