Image Sensor Depth-Defined Photodetectors for Visible Infrared Switching
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Solution Overview
Problem
Conventional imaging systems that capture both visible and infrared light images often require mechanical filters, which are expensive and prone to failure, to prevent interference between visible and infrared light data.
Innovation Solution
An image sensor with a semiconductor substrate containing visible light photodetectors and combination light photodetectors, where the combination light photodetectors have a greater depth than visible light photodetectors, allowing for automatic switching between visible and infrared light operating modes without moving parts, using a channel controller to filter data based on threshold comparisons.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If mechanical filters are used to prevent interference between visible and infrared light data, then the imaging system can capture clear images in both visible and infrared modes, but the device becomes expensive and prone to failure
Solution Approach 1:
The patent replaces mechanical filter systems with an integrated semiconductor substrate that uses electronic control to switch between visible and infrared light detection modes. The image sensor contains both visible light photodetectors and combination light photodetectors with different depths, allowing electronic mode switching without moving mechanical parts, thereby eliminating the reliability issues and complexity associated with mechanical filters
Solution Approach 2:
The image sensor is designed with dual functionality to detect both visible light and infrared light using the same physical substrate. The combination light photodetectors can respond to both visible and infrared wavelengths, while the visible light photodetectors respond only to visible light, enabling a single device to perform multiple imaging functions without requiring separate sensors or mechanical filter changes
2Adaptability or versatility
If mechanical filters are used to block infrared or visible light, then the imaging system can operate in pure visible or pure infrared mode, but the system requires moving parts which are expensive and failure prone
Solution Approach 1:
The patent eliminates mechanical filter systems by using an integrated semiconductor substrate with electronically controlled photodetector arrays. The system switches between visible and infrared modes by electronically controlling which photodetector types are active, replacing mechanical moving parts with solid-state electronic control, thereby improving reliability while maintaining adaptability to different lighting conditions
3Measurement precision
If the image sensor uses photodetectors of the same depth, then the structure is simpler, but it cannot effectively distinguish between visible and infrared light signals
Solution Approach 1:
The patent applies local quality by creating photodetectors with different depths within the same semiconductor substrate. The visible light photodetectors have a first depth optimized for visible light detection, while the combination light photodetectors have a greater second depth that allows them to detect both visible and infrared light. This localized structural differentiation enables precise spectral discrimination without requiring entirely separate sensor systems
Solution Approach 2:
The patent introduces depth as an additional dimensional parameter to differentiate photodetector functionality. By varying the depth of photodetectors within the semiconductor substrate, the system creates distinct detection zones that respond differently to visible and infrared wavelengths, adding a spatial dimension to spectral discrimination capability
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
Enables efficient and reliable capture of both visible and infrared light images without mechanical filters, reducing costs and failure risks, and allowing for automatic mode switching based on illumination conditions.
Implementation Method 1
Each of the plurality of combination light photodetectors has a respective depth in the height direction that is greater than the respective depth of each of the plurality of visible light photodetectors
Data Source
AI summary
An image sensor for capturing both visible light images and infrared light images includes a semiconductor substrate having length, width, and height, a plurality of visible light photodetectors disposed in the semiconductor substrate, and a plurality of combination light photodetectors disposed in the semiconductor substrate. Each of the plurality of visible light photodetectors has a respective depth in the height direction, and each of the plurality of combination light photodetectors has a respective depth in the height direction that is greater than the respective depth of each of the plurality of visible light photodetectors.