Phase Difference Detection Pixel Arrangement for Oblique Edge Focus Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Phase difference AF methods in solid-state image-capture elements often falsely detect phase differences when an edge of a subject extends obliquely, leading to reduced precision in focus control.
Innovation Solution
A solid-state image-capture element with pairs of phase difference detection pixels arranged in intersecting directions, where the positional relation of the pixels is reversed, allowing for accurate phase difference detection irrespective of edge direction, using a configuration that includes multiple pairs to enhance precision.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If phase difference AF method uses pixels with optical openings arranged in specific directions to detect focus position, then focus detection speed and precision are improved, but false detection occurs when subject edges extend obliquely
Solution Approach 1:
The pixel array is segmented into multiple pairs of phase difference detection pixels, where each pair detects phase difference in a specific direction. By dividing the detection function across multiple specialized pixel pairs, the system can accurately detect phase differences in various directions without false detection
Solution Approach 2:
Pairs of phase difference detection pixels are arranged asymmetrically with respect to the optical axis, with each pair having a specific positional relationship that enables detection in particular directions. This asymmetric arrangement allows the system to handle oblique edges by using multiple pairs with different orientations
2Measurement precision
If multiple pairs of phase difference detection pixels are arranged in different directions, then detection precision for various edge orientations is improved, but device complexity increases
Solution Approach 1:
Multiple pairs of phase difference detection pixels serve universal detection purposes by covering different directional requirements. Each pair can be used to detect phase differences in its specific direction, and collectively they provide comprehensive phase difference detection capability for various edge orientations
Solution Approach 2:
The pixel pairs are arranged in the row direction (horizontal dimension) with specific positional relationships, adding a spatial dimension to the detection capability. This dimensional arrangement enables the system to detect phase differences in multiple directions without requiring vertical stacking of pixels
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
Maintains phase difference detection precision and prevents false detection of phase differences, even when edges are inclined, thereby improving focus control accuracy.
Implementation Method 1
a first phase difference detection pixel 51L that receives one of a pair of light beams passing through iris areas of different positions of an imaging lens 1 and a second phase difference detection pixel 51R that receives the other of the pair of light beams
Data Source
AI summary
A solid-state image capture element includes a pixel, which receives light of one of a pair of light beams which pass through iris regions of different locations on a photographic lens, and a pixel which receives light of the other, in a pair of said pixels. The pair of pixels are positioned shifted from one another in a direction which intersects the x-axis which is the phase difference direction. The pair includes a plurality of first pairs and second pairs which respectively have mutually inverse location relations with respect to the pixels and the pixels therein. The first pair and the second pair are alternately positioned in either the phase difference detection direction or the direction which is orthogonal thereto.