Solid-State Imaging Pixel Accumulators for Motion Blur Suppression
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Solution Overview
Problem
Conventional solid-state imaging devices experience motion blur when obtaining distance images of moving subjects, leading to decreased frame rates and significant distance measuring errors due to background light and dark current components.
Innovation Solution
A solid-state imaging device with a pixel structure that includes multiple charge accumulators and read gates, employing a signal interchange method to suppress motion blur by evenly distributing differences in read characteristics and background light, dark current, and parasitic sensitivity components across multiple frames without using additional frames.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional solid-state imaging devices obtain distance images of moving subjects, then distance measurement is achieved, but motion blur occurs and frame rate decreases
Solution Approach 1:
The pixel is divided into multiple charge accumulators (first charge accumulator and second charge accumulator) that independently accumulate signal charges at different timing. This segmentation allows parallel processing of multiple distance measurements within a single frame period, enabling motion blur suppression while maintaining high frame rate by calculating multiple distance values and selecting the most appropriate one based on object motion characteristics.
2Measurement precision
If conventional solid-state imaging devices use multiple frames to suppress motion blur, then measurement accuracy improves, but frame rate decreases due to additional frame requirements
Solution Approach 1:
Signal charges are accumulated at periodic intervals corresponding to different phases of the light source emission cycle. The first charge accumulator accumulates charges during periods when the light source is not emitting, while the second charge accumulator accumulates charges during light emission periods. This periodic accumulation within a single frame enables motion blur suppression without requiring additional frames, thereby maintaining high frame rate.
3Length of stationary object
If conventional solid-state imaging devices accumulate signal charges at different timing, then distance measurement range is extended, but differences in read characteristics and background light components cause measurement errors
Solution Approach 1:
The system calculates multiple distance values from signal charges accumulated at different timing and uses feedback mechanisms to select the most appropriate distance value. By comparing distance values obtained from different charge accumulators and considering the temporal characteristics of object motion, the system feedback-selects the most accurate measurement, thereby suppressing errors caused by read characteristic differences and background light components while maintaining extended measurement range.
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 effectively suppresses motion blur and reduces distance measuring errors by canceling out differences in read characteristics and background light components, achieving high accuracy and maintaining frame rate.
Implementation Method 1
a photoelectric converter that converts received light into a signal charge
Data Source
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Figure 3A
AI summary
A solid-state imaging device (100) includes: pixels (20) arranged in a matrix on a semiconductor substrate. Each of the pixels (20) includes: a photoelectric converter (1) that converts received light into a signal charge; at least one read gate (6) that reads the signal charge from the photoelectric converter (1); charge accumulators (2) that each accumulate the signal charge read by the at least one read gate (6); and a charge holder (10) that receives, from one of the charge accumulators (2), transfer of the signal charge accumulated in the charge accumulator (2), holds the signal charge, and transfers, to one of the charge accumulators (2), the signal charge held, each of the charge accumulators (2) includes a part of a transfer channel (4) and a part of a transfer electrode (5) overlapping with the part of the transfer channel in a planar view of the semiconductor substrate, and the transfer channel (4) per one pixel comprises transfer channels.