Optical Sensor Opaque Layer for Ambient Light Foreground Distinction
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Solution Overview
Problem
Conventional imaging devices struggle to effectively distinguish foreground from background under strong ambient light conditions, such as sunlight, due to the weak brightness of system light sources compared to ambient light.
Innovation Solution
The implementation of an imaging device that utilizes phase detection and operates in different modes based on ambient light intensity, featuring a pixel matrix with unblocked pixels and pixels covered by an opaque layer, allowing for effective foreground-background separation even in strong light conditions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a system light source is used to illuminate the object for foreground-background distinction, then the image sensor can capture bright and dark images for differential calculation, but the background interference cannot be effectively cancelled under strong ambient light conditions
Solution Approach 1:
The pixel matrix is divided into multiple types of pixels with different functions: unblocked pixels for normal imaging, first pixels and second pixels with opaque layers for phase detection. This segmentation allows the system to simultaneously capture both intensity information and phase information, enabling effective foreground-background distinction even under strong ambient light conditions where conventional differential imaging fails.
Solution Approach 2:
An opaque layer is introduced as an intermediary element that selectively blocks light for specific pixels (first and second pixels) while allowing light to reach unblocked pixels. This intermediary structure enables the system to detect phase differences by comparing signals from pixels with and without the opaque layer, providing a mechanism to distinguish foreground objects from background regardless of ambient light intensity.
2Reliability
If the system light source brightness is increased to overcome ambient light, then foreground detection may improve, but the device complexity and power consumption increase
Solution Approach 1:
Instead of uniformly increasing the brightness of the entire system light source, the patent applies local quality modification by introducing opaque layers only in specific regions (first and second pixels) of the pixel matrix. This localized approach allows phase detection functionality to be added without requiring a complete redesign of the lighting system, thereby limiting the increase in device complexity while improving reliability under various lighting conditions.
Data Source
AI summary
An optical sensor including a pixel matrix and an opaque layer is provided. The pixel matrix includes a plurality of unblocked pixels, a first pixel and a second pixel, which is arranged at a side of the first pixel in a row direction of the pixel matrix. The opaque layer covers upon a first region, which is a part of the first pixel, and upon a second region, which is a part of the second pixel, but does not cover upon the unblocked pixels, wherein the first region and the second region are symmetrically arranged in the row direction, and uncovered regions of the first pixel and the second pixel are arranged to be larger at a pixel edge than at a pixel center in a column direction of the pixel matrix.