Solid-State Imaging Pixel Reset Timing Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional solid-state imaging devices experience motion blur when capturing video with significant luminance changes due to parasitic capacitance between pixels, causing the image of the previous frame to appear in the current frame.
Innovation Solution
A method for driving a solid-state imaging device where the reset operation on pixels in one row is ended before starting or during the reset operation on adjacent rows, or by staggering the reset and readout operations to minimize signal coupling between rows, thereby preventing motion blur.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If reset operation is performed on all rows simultaneously, then reset efficiency is improved, but motion blur occurs due to parasitic capacitance coupling between adjacent rows
Solution Approach 1:
The reset operation is segmented into sequential row-by-row operations rather than simultaneous execution. The control circuit resets pixels in the first row, then sequentially proceeds to the second row, and so on through the n-th row. This segmentation prevents parasitic capacitance coupling between adjacent rows from causing motion blur, while still achieving complete reset coverage across all pixel rows.
2Reliability
If reset operation time is extended to cover all rows, then complete reset is achieved, but image capture time increases
Solution Approach 1:
The sequential reset operation is integrated into the image capture timing sequence. While pixel signals are being read out from earlier rows, the reset operation has already progressed to subsequent rows. This preliminary action ensures that by the time a row's signal readout completes, that row has already been reset and is ready for the next frame, maintaining reset completeness without extending the overall image capture time.
3Reliability
If sequential row-by-row reset is implemented, then motion blur is eliminated, but reset operation complexity increases
Solution Approach 1:
The sequential reset operation maintains continuous useful action by overlapping the reset timing with the signal readout timing. While pixel signals from the first row are being read out, the reset operation simultaneously proceeds to the second row, and so on. This continuity ensures that the sequential operation does not create idle time or gaps, and the control circuit manages the sequencing without requiring additional complex control mechanisms beyond the existing readout control structure.
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 approach allows for high-quality image capture without motion blur, even under conditions of significant luminance change, by eliminating output fluctuations caused by reset operation coupling between rows.
Implementation Method 1
Each of a complementary metal oxide semiconductor (CMOS) area image sensor and a metal oxide semiconductor (MOS) area image sensor (hereinafter, both referred to as the CMOS solid-state imaging device) and a charge coupled device (CCD) area image sensor (hereinafter, referred to as the CCD solid-state imaging device) generates an image signal by converting an input optical image into an electrical signal.
Data Source
AI summary
Provided is a method for driving a solid-state imaging device. The solid-state imaging device including pixels arranged in a two-dimensional array of m columns in a horizontal scanning direction and n rows in a vertical scanning direction (n is an integer no less than 2 and m is a natural number). The method including ending a reset operation on pixels in an i-th row among the pixels when (i) a reset operation on pixels in an (i+1)-th row among the pixels is in progress or (ii) time elapsed from when the reset operation on the pixels in the (i+1)-th row is ended is less than one-frame capturing time, where i is an integer no less than 1 and no greater than (n−1).