Imaging Pixel Light Path Structure for Stray-Light Crosstalk
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Solution Overview
Problem
Conventional imaging devices suffer from crosstalk due to stray light entering the imaging device, which is not effectively blocked by existing light-blocking structures, leading to reduced image quality.
Innovation Solution
The implementation of a light path portion with a transparent film, light-blocking walls, and a light-blocking film arranged near the end of the light-blocking walls, which includes openings for incident light transmission, along with an on-chip lens to collect and direct light into the photoelectric converters, effectively blocking stray light and reducing crosstalk.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If a light-collecting structure long in height with on-chip lens at high position is adopted, then light collection capability is improved, but crosstalk in surrounding pixels increases
Solution Approach 1:
The light-blocking walls and light-blocking film are positioned to preemptively block stray light before it can reach the photoelectric converters through the long light-collecting structure. By placing these blocking elements at strategic positions within the extended light path, the structure prevents harmful light from entering while still allowing desired light to reach the sensors.
2Illumination intensity
If pupil correction is performed by shifting on-chip lens and color filter, then sensitivity to obliquely incident light is improved, but light from different pixels enters adjacent photoelectric converters
Solution Approach 1:
The light-blocking structure is designed with local variations: light-blocking walls and film openings are positioned and sized differently for pixels at different locations (central vs. surrounding pixels). This local customization allows optimal blocking performance for each pixel's specific angular requirements while maintaining pupil correction benefits, preventing light from adjacent pixels from entering wrong converters.
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 configuration significantly reduces crosstalk caused by stray light, thereby enhancing image quality and sensitivity of the imaging device.
Implementation Method 1
a plurality of photoelectric converters each formed on a semiconductor substrate and each performing photoelectric conversion according to incident light
Implementation Method 2
an on-chip lens that is arranged for each of the plurality of photoelectric converters, and collects the incident light into the photoelectric converter through the light path portion
Implementation Method 3
a light-blocking wall for each of the plurality of photoelectric converters, the light-blocking wall partitioning the transparent film in a direction perpendicular to the semiconductor substrate, and blocking light
Data Source
AI summary
A plurality of photoelectric converters is formed on a semiconductor substrate and performs photoelectric conversion according to incident light. A light path portion includes a transparent film through which the incident light is transmitted, a light-blocking wall for each of the plurality of photoelectric converters, the light-blocking wall partitioning the transparent film in a direction perpendicular to the semiconductor substrate, and blocking light, and a light-blocking film at an end of the light-blocking wall, the end being opposite to an end of the light-blocking wall that is closer to the semiconductor substrate, the light-blocking film having a film shape parallel to the semiconductor substrate, and including, for each of the plurality of photoelectric converters, an opening through which the incident light is transmitted. An on-chip lens is arranged for each of the plurality of photoelectric converters, and collects the incident light into the photoelectric converter through the light path portion.