Solid-State Image Sensor Pixel Layout for Corner ID Encoding
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Solution Overview
Problem
Solid-state imaging devices face challenges in downsizing due to increased chip area requirements, particularly in applications like endoscopes, where the non-image area at the periphery of the image circle increases the overall chip size, and the phenomenon of vignetting reduces light intensity at the peripheral portions, necessitating area-efficient solutions for individual identification.
Innovation Solution
A quadrilateral pixel array with first pixels for capturing images and second pixels for individual identification, placed near the corners of the array, which include circuit or optical elements distinct from the first pixels, allowing for unique identification without increasing the chip area by utilizing different signal processing and optical configurations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a non-image area is placed at the outer periphery of the image area to enable individual identification, then individual identification capability is improved, but chip area increases
Solution Approach 1:
The patent applies local quality by creating distinct pixel types (first pixels for image capture and second pixels for individual identification) with different circuit elements and optical characteristics at specific locations within the pixel array. This allows the chip to maintain compact size while incorporating identification functionality in a localized manner without requiring a separate non-image area at the periphery.
Solution Approach 2:
The patent implements multi-functionality by enabling pixels to serve dual purposes: some pixels can function as both image capture elements and individual identification elements depending on their circuit configuration. The second pixels with unique circuit elements provide identification capability while being integrated within the same chip area as the first pixels, eliminating the need for separate dedicated identification areas.
2Measurement precision
If the pixel array is designed to maximize image capture area within the circular image circle, then image quality is improved, but device complexity increases due to vignetting correction requirements
Solution Approach 1:
The patent extracts the individual identification function from the image capture function by using separate second pixels with distinct circuit elements. These second pixels are positioned to receive light through the lens and provide identification information independently from the first pixels that capture the image. This separation allows the image capture area to be optimized for quality while the identification function handles vignetting correction requirements separately.
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 individual identification of the solid-state imaging device without expanding the chip area, suitable for downsizing applications, and effectively addresses vignetting by using distinct signal processing and optical elements in second pixels.
Implementation Method 1
each of the pixels accumulates an electric charge resulting from photoelectric conversion
Data Source
AI summary
A solid-state imaging device includes a pixel array that is quadrilateral and includes pixels arranged in rows and columns, where each of the pixels accumulates an electric charge resulting from photoelectric conversion. The pixel array includes: a first area including first pixels for obtaining a captured image; and a second area including a second pixel for individually identifying the solid-state imaging device. The second area is provided in the vicinity of at least one corner among four corners of the pixel array, where the vicinity is a range of a predetermined number of pixels away from the at least one corner. The second pixel includes circuit elements or optical elements different from circuit elements or optical elements in each of the first pixels.