Image Sensor Row Column Selection Circuit for Faster Live View and Autofocus
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional imaging apparatuses experience prolonged image updating times in live view display and increased Auto Focus (AF) intervals when switching between modes, leading to decreased display performance and longer AF response times, especially when capturing moving subjects.
Innovation Solution
An image sensor with a row and column selection circuit that alternates between skip-read-out and whole-pixels-read-out modes, allowing for efficient selection and output of pixel signals from imaging and focus detection pixels, ensuring faster image updating and accurate focus detection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If the imaging apparatus switches between skip mode and whole-pixels-read-out mode alternately for live view display and focus detection, then both functions can be performed, but the period of time for updating images in live view display is prolonged and AF intervals become longer
Solution Approach 1:
The image sensor is segmented into two distinct regions: a first region containing imaging pixels for live view display and a second region containing focus detection pixels for autofocus. This spatial segmentation allows both functions to operate simultaneously on different portions of the sensor, eliminating the need to alternate between modes and thus reducing image updating time while maintaining dual functionality.
2Adaptability or versatility
If the imaging apparatus switches between skip mode and whole-pixels-read-out mode alternately, then both live view and focus detection are enabled, but AF response time increases
Solution Approach 1:
The image sensor is segmented into two distinct regions: a first region containing imaging pixels for live view display and a second region containing focus detection pixels for autofocus. This spatial segmentation allows both functions to operate simultaneously on different portions of the sensor, eliminating the need to alternate between modes and thus reducing image updating time while maintaining dual functionality.
Solution Approach 2:
Focus detection pixels are pre-positioned in the second region of the sensor, allowing focus detection to occur continuously or at higher priority intervals without waiting for the completion of live view readout operations. This preliminary preparation of focus detection capability enables faster AF response when needed.
3Measurement precision
If all lines are read out for still-image imaging to obtain high resolution, then image quality is improved, but the time required for image capturing increases
Solution Approach 1:
The image sensor is segmented into two distinct regions: a first region containing imaging pixels for live view display and a second region containing focus detection pixels for autofocus. This spatial segmentation allows both functions to operate simultaneously on different portions of the sensor, eliminating the need to alternate between modes and thus reducing image updating time while maintaining dual functionality.
Solution Approach 2:
For live view display, only a portion of the imaging pixels in the first region are read out at any given time rather than all pixels, enabling faster updating rates. When still-image capture is required, the full resolution capability is activated by reading out all pixels in the first region, thus providing high resolution when needed without sacrificing live view performance.
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 approach enhances the speed of live view display and focus detection, reducing AF intervals and improving response times while maintaining high-quality image display.
Implementation Method 1
a plurality of imaging pixels disposed two-dimensionally in rows and columns for receiving light from a subject via an optical system to capture an image
Implementation Method 2
a plurality of first focus detection pixels each receiving one of a pair of light fluxes for focus detection via the optical system and a plurality of second focus detection pixels each receiving the other of the pair of light fluxes for focus detection
Data Source
AI summary
An image sensor includes: a plurality of imaging pixels disposed two-dimensionally in rows and columns to capture an image; a plurality of first focus detection pixels for focus detection and a plurality of second focus detection pixels for focus detection being disposed in a row in place of the imaging pixels; a row selection circuit that selects in turn a row; a column selection circuit that selects in turn a column; and an output circuit that outputs pixel signals from the pixels selected by the column selection circuit, out of the pixels in the rows selected by the row selection circuit, wherein the column selection circuit selects a column according to whether or not the row selected by the row selection circuit includes the first and the second focus detection pixels.