Solid-State Image Sensor Charge Accumulation for Distance Measurement
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Solution Overview
Problem
Existing imaging devices face challenges in accumulating sufficient signal charges when multiple types of periods or conditions are used for measurements, leading to reduced accuracy in calculating object distances or internal information.
Innovation Solution
The proposed imaging device includes a light source, a solid-state image sensor with multiple photoelectric converters and charge accumulators, and a controller that performs multiple exposure sequences within one frame period, assigning charge accumulators exclusively to each sequence and accumulating signal charges from multiple photoelectric converters in at least one sequence.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If multiple types of periods or conditions are used for measurements, then measurement versatility is improved, but signal charge accumulation becomes insufficient
Solution Approach 1:
The image sensor is divided into multiple independent charge accumulators, each dedicated to accumulating signal charges for a specific type period or measurement condition. This segmentation allows simultaneous accumulation of sufficient signal charges across multiple measurement types without interference, resolving the contradiction between measurement versatility and signal charge accumulation.
2Adaptability or versatility
If multiple types of periods or conditions are used for measurements, then measurement versatility is improved, but measurement precision is reduced
Solution Approach 1:
By providing dedicated charge accumulators for each measurement type, the system ensures that signal charges for each specific measurement are accumulated independently without being diluted or contaminated by other measurement types. This maintains high measurement precision while supporting multiple measurement conditions.
3Device complexity
If charge accumulators are shared among multiple exposure sequences, then device complexity is reduced, but signal charge accumulation becomes insufficient
Solution Approach 1:
The system implements a segmented architecture where charge accumulators are dedicated to specific exposure sequences or measurement types. While this increases the total number of accumulators compared to a shared approach, it ensures sufficient signal charge accumulation for each measurement type without requiring complex switching mechanisms or charge transfer operations.
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 the imaging device to accumulate sufficient signal charges even with four or more types of periods or conditions, enabling accurate calculation of object distances and internal information.
Implementation Method 1
signal charges that are each the signal charge, and a plurality of charge accumulators that accumulate the signal charges
Data Source
AI summary
An imaging device includes: a solid-state image sensor that is exposed to reflection light from an object and accumulates signal charges; and a control arithmetic device that controls irradiation by an infrared light source and exposure of the solid-state image sensor. The solid-state image sensor includes: photoelectric converters that convert the reflection light from the object into the signal charges; and charge accumulators that accumulate the signal charges. The imaging device performs, within one frame period, m types of exposure sequences (m is an integer greater than or equal to four) for controlling the irradiation and the exposure; assigns the charge accumulators exclusively to the m types of exposure sequences; accumulates, into the charge accumulators, the signal charges obtained from n (n is an integer greater than or equal to three) of the photoelectric converters in at least one type of exposure sequence among the m types of exposure sequences.