Solid-State Imaging Device Charge Readout via Potential Gradient
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Solution Overview
Problem
The existing solid-state imaging devices face challenges in quickly reading out charges generated in photosensitive regions due to long migration distances and complex image processing requirements, which complicates the detection of incident light intensity across varying ranges.
Innovation Solution
A solid-state imaging device with a potential gradient forming region that directs charge migration towards short sides, eliminating the need for additional signal processing and enabling faster charge readout, and utilizing first and second charge output portions to manage charge transfer during different exposure periods, thereby enhancing dynamic range detection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If charge is read out from the short side of the photosensitive region, then the readout structure is simplified, but the migration distance becomes long and readout speed decreases
Solution Approach 1:
The patent changes the charge migration direction from the long side direction to the short side direction by forming a potential gradient along the short side direction. This dimensional change in the potential gradient formation allows charge to migrate along the short side direction, significantly shortening the migration distance and improving readout speed while maintaining the simplified readout structure
2Adaptability or versatility
If amplifier regions are arranged adjacent to both short sides for signal output, then signal output capability is improved, but image processing becomes complicated
Solution Approach 1:
The patent extracts the charge migration path from the complex two-sided readout configuration and directs all charge migration toward a single short side through the potential gradient. This extraction of the migration path simplifies the system by eliminating the need for complex signal processing to combine outputs from both sides, while still maintaining versatile signal output capability through the single simplified path
3Measurement precision
If photosensitive region has large area for high sensitivity, then detection sensitivity is improved, but charge migration distance increases and readout speed decreases
Solution Approach 1:
The patent applies local quality by creating a non-uniform potential distribution through the potential gradient along the short side direction. This local variation in potential strength guides charge migration efficiently toward the readout electrode, allowing the photosensitive region to maintain a large area for high sensitivity while ensuring rapid charge collection through the localized strong potential gradient field
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
The device achieves quick charge readout without complicating image processing and effectively detects incident light intensity across a wide range, improving the dynamic range of signal detection.
Implementation Method 1
a potential gradient forming region configured to form a potential gradient increasing along a first direction directed from one short side to the other short side in the photosensitive region
Implementation Method 2
a photosensitive region configured to generate a charge according to incidence of light
Data Source
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AI summary
A solid-state imaging device 1 is provided with a plurality of photoelectric converting portions 3 and first and second shift registers 9, 13. Each photoelectric converting portion 3 has a photosensitive region 15 which generates a charge according to incidence of light and which has a planar shape of a nearly rectangular shape composed of two long sides and two short sides, and a potential gradient forming region 17 which forms a potential gradient increasing along a predetermined direction parallel to the long sides forming the planar shape of the photosensitive region 15, in the photosensitive region, 15. The plurality of photoelectric converting portions 3 are juxtaposed along a direction intersecting with the predetermined direction. The first and second shift registers 9, 13 acquire charges transferred from the respective photoelectric converting portions 3 and transfer them in the direction intersecting with the predetermined direction to output them. This achieves the solid-state imaging device capable of quickly reading out the charge generated in the photosensitive region, without complicating image processing.