Image Sensor Pixel Block Asymmetry for Signal Uniformity
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Solution Overview
Problem
Existing image sensors with shared pixel structures face differences in image signals due to varying distances of unit pixels from the driving circuit, leading to interference and parasitic capacitance, which affects image quality.
Innovation Solution
The image sensor employs a matrix structure with pixel blocks having symmetrical or inverted planar shapes and color filter arrays with consistent patterns to minimize differences in image signals by merging signals from adjacent pixel blocks, ensuring uniform output.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If unit pixels are arranged with different distances from the driving circuit, then the pixel block can accommodate more unit pixels, but image signal differences and fixed pattern noise increase
Solution Approach 1:
The patent applies asymmetry by inverting the planar shape of adjacent pixel blocks. Specifically, when a first pixel block has a certain planar shape, an adjacent second pixel block has an inverted planar shape. This asymmetric arrangement between adjacent blocks ensures that unit pixels at corresponding positions maintain consistent distances to their respective driving circuits, thereby reducing fixed pattern noise while still allowing high-density pixel arrangement.
2Area of stationary object
If pixel blocks have different planar shapes, then space utilization is improved, but signal interference and parasitic capacitance increase
Solution Approach 1:
The patent uses asymmetry between adjacent pixel blocks through shape inversion. The first pixel block and second pixel block have inverted planar shapes, which optimizes space utilization while maintaining consistent electrical characteristics. This asymmetric design prevents signal interference and parasitic capacitance by ensuring that corresponding unit pixels in adjacent blocks have equivalent geometric relationships with their driving circuits.
3Adaptability or versatility
If unit pixels are positioned at different distances from the driving circuit, then layout flexibility is improved, but image quality deteriorates due to fixed pattern noise
Solution Approach 1:
The patent implements asymmetry at the pixel block level rather than within individual blocks. Each pixel block internally maintains a regular, symmetric arrangement of unit pixels around a central floating diffusion region. However, adjacent pixel blocks have inverted planar shapes, providing layout flexibility at the macro level while preserving image quality at the micro level through consistent unit pixel-to-driving-circuit distances.
Solution Approach 2:
The patent segments the pixel array into multiple pixel blocks with inverted planar shapes. Each pixel block is an independent unit containing unit pixels and a driving circuit. This segmentation allows the overall array to achieve flexible space utilization through shape inversion between blocks, while each individual block maintains regular internal structure for consistent electrical characteristics and high image quality.
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 approach prevents differences in image signals from unit pixels, enhancing image quality and resolution by reducing fixed pattern noise and maintaining consistent color filter patterns across pixel blocks.
Implementation Method 1
a photoelectric conversion element PD which converts light into an electrical signal
Data Source
AI summary
An image sensor may include a pixel array that includes a plurality of pixel blocks arranged in an M×N (where M and N are natural numbers) matrix structure, wherein, among the plurality of pixel blocks, when compared to any one pixel block as a first pixel block, any one pixel block as a second pixel block adjacent to the first pixel block in an M direction or an N direction has a planar shape that is obtained by inverting a planar shape of the first pixel block in the M direction. Each of the plurality of pixel blocks may include a light reception unit including a plurality of unit pixels which generate photocharges in response to incident light and are arranged in an m×n matrix structure to have a shared pixel structure; and a driving circuit suitable for outputting an image signal corresponding to the photocharges.