Image Sensor Stacked Pixel Arrays with Varying Spacing
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Solution Overview
Problem
Existing image sensing devices face challenges in ensuring a sufficient amount of light reaches photoelectric conversion elements, particularly in edge regions due to uniform pixel spacing, leading to unbalanced light detection.
Innovation Solution
A three-dimensional stacked structure with a lower pixel array and an upper pixel array, where the upper pixel array receives incident light and a portion passes through to the lower pixel array, and the lower pixel array's unit pixels are arranged with varying spacing to accommodate the Chief Ray Angle, ensuring sufficient light reaches photoelectric conversion elements.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If uniform pixel spacing is used in the lower pixel array, then manufacturing is simplified, but light detection becomes unbalanced in edge regions
Solution Approach 1:
The patent applies local quality by varying the pixel spacing in the lower pixel array based on position. Specifically, pixels in edge regions are spaced differently from pixels in center regions, allowing each region to be optimized for its specific light reception characteristics. This non-uniform spacing compensates for the reduced light intensity at edges, achieving balanced light detection across the entire sensor array.
2Device complexity
If a single pixel array is used, then device complexity is reduced, but light detection efficiency decreases
Solution Approach 1:
The patent transitions from a two-dimensional single pixel array to a three-dimensional stacked pixel array structure. The lower pixel array is positioned beneath the upper pixel array, allowing light to reach both arrays simultaneously. This vertical stacking enables the system to detect light with higher efficiency while maintaining a compact form factor, effectively adding a spatial dimension to the detection system.
3Ease of manufacture
If the lower pixel array is positioned directly below the upper pixel array with uniform spacing, then alignment is simplified, but sufficient light cannot reach photoelectric conversion elements in edge regions
Solution Approach 1:
The patent implements local quality by adjusting the spacing of pixels in the lower pixel array according to their position. Edge region pixels are spaced to receive adequate oblique light, while center region pixels maintain standard spacing. This position-dependent spacing optimization ensures that sufficient light reaches photoelectric conversion elements across all regions of the lower pixel array, resolving the illumination imbalance problem.
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 allows for balanced light detection across the image sensing device, preventing unbalanced light distribution and enhancing the operational efficiency of photoelectric conversion elements, particularly in edge regions.
Implementation Method 1
The first pixel array includes a plurality of first unit pixels consecutively arranged to generate a first pixel signal through a photoelectric conversion of incident light. The second pixel array is disposed below the first pixel array, and includes a plurality of second unit pixels consecutively arranged to generate a second pixel signal through a photoelectric conversion of the incident light.
Data Source
AI summary
An image sensing device includes a first pixel array and a second pixel array. The first pixel array includes a plurality of first unit pixels consecutively arranged to generate a first pixel signal through a photoelectric conversion of incident light. The second pixel array is disposed below the first pixel array, and includes a plurality of second unit pixels consecutively arranged to generate a second pixel signal through a photoelectric conversion of the incident light. The first unit pixels are arranged to have a uniform spacing between adjacent first unit pixels in the first pixel array. The second unit pixels are arranged so that spacing between adjacent second unit pixels are not the same in the second pixel array.