Enhancing Autofocus in Solid-State Imaging Devices
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Summary
Problems
Solid-state imaging devices face challenges in improving autofocusing (AF) speed and accuracy due to limitations in phase difference detection pixels, where increasing the number of phase difference detection pixels can reduce sensitivity and AF accuracy, and providing a charge storage unit decreases the area of photoelectric conversion units, affecting AF performance.
Innovation solutions
The implementation of a solid-state imaging device with a pixel array unit that includes imaging pixels and phase difference detection pixels, where each phase difference detection pixel has multiple photoelectric conversion units sharing a floating diffusion and amplification transistor with adjacent imaging pixels, allowing simultaneous exposure and reading without a charge storage unit, thereby enhancing AF speed and accuracy.
TRIZ Analysis
Specific contradictions:
General conflict description:
Principle concept:
If two photoelectric conversion units share one amplification transistor, then device complexity is reduced, but it becomes impossible to expose and read from the two photoelectric conversion units simultaneously, reducing AF tracking capabilities
Why choose this principle:
The pixel array is divided into multiple pixel units, where each pixel unit contains photoelectric conversion units and associated readout circuitry. This segmentation allows different pixel units to operate independently and simultaneously, enabling parallel exposure and reading of multiple photoelectric conversion units while maintaining manageable device complexity
Principle concept:
If two photoelectric conversion units share one amplification transistor, then device complexity is reduced, but it becomes impossible to expose and read from the two photoelectric conversion units simultaneously, reducing AF tracking capabilities
Why choose this principle:
The amplification transistor serves multiple functions by being shared among multiple photoelectric conversion units within the same pixel unit. This multi-functionality reduces the total number of amplification transistors required in the device while still enabling simultaneous operation through the segmented pixel unit architecture
Application Domain
Data Source
AI summary:
The implementation of a solid-state imaging device with a pixel array unit that includes imaging pixels and phase difference detection pixels, where each phase difference detection pixel has multiple photoelectric conversion units sharing a floating diffusion and amplification transistor with adjacent imaging pixels, allowing simultaneous exposure and reading without a charge storage unit, thereby enhancing AF speed and accuracy.
Abstract
A solid-state imaging device includes a pixel array unit in which a plurality of imaging pixels configured to generate an image, and a plurality of phase difference detection pixels configured to perform phase difference detection are arranged, each of the plurality of phase difference detection pixels including a plurality of photoelectric conversion units, a plurality of floating diffusions configured to convert charges stored in the plurality of photoelectric conversion units into voltage, and a plurality of amplification transistors configured to amplify the converted voltage in the plurality of floating diffusions.