Solid-State Imaging Device Dummy A/D Conversion for Linear Noise Reduction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Radiation imaging systems face issues with linear noise at the boundary lines of integrated images due to discontinuous pixel values from parallel readout of imaging pixel regions, where the arrangement direction crosses the moving direction, causing repeated integration and emphasizing noise.
Innovation Solution
A solid-state imaging device with a moving mechanism and an image generation unit, featuring L imaging pixel regions, row and column selection units, and A/D converters, where a control system instructs dummy A/D conversions after converting one row and before converting the next, to stabilize A/D converter output characteristics and reduce noise.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If pixel data from multiple imaging pixel regions are read out in parallel to increase readout speed, then productivity is improved, but linear noise appears at boundary lines due to discontinuous pixel values
Solution Approach 1:
The patent applies preliminary action by performing dummy A/D conversions before actual A/D conversions to stabilize the output characteristics of the A/D converter. Specifically, the control unit causes the A/D converter to perform a predetermined number of dummy conversions on input signals from the imaging pixel regions before conducting actual conversions on subsequent rows. This preliminary stabilization action prevents discontinuous pixel values at boundary lines, thereby eliminating linear noise in the integrated image while maintaining parallel readout speed.
2Speed
If the light receiving part is divided into multiple imaging pixel regions arranged in the longitudinal direction, then readout speed is improved through parallel reading, but pixel value discontinuity occurs at boundary lines
Solution Approach 1:
The patent applies preliminary action by performing dummy A/D conversions before actual A/D conversions to stabilize the output characteristics of the A/D converter. Specifically, the control unit causes the A/D converter to perform a predetermined number of dummy conversions on input signals from the imaging pixel regions before conducting actual conversions on subsequent rows. This preliminary stabilization action prevents discontinuous pixel values at boundary lines, thereby eliminating linear noise in the integrated image while maintaining parallel readout speed.
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 solution effectively reduces linear noise in integrated images by stabilizing A/D converter output characteristics and minimizing discontinuities at boundary lines, improving image quality by integrating frame images shifted according to the moving speed of the device.
Implementation Method 1
L pieces of A/D converter respectively provided corresponding to the L pieces of imaging pixel region... convert the analog signal transmitted via the output wiring into a digital signal constituting a frame image
Implementation Method 2
captures a radiation image of a subject irradiated with radiation from a radiation source
Data Source
Figure 1
Figure 2
Figure 3
AI summary
The present embodiment relates to a radiation imaging system and the like provided with a solid-state imaging device having a structure enabling reduction of linear noise appearing in an integrated image. The solid-state imaging device comprises: L pieces of imaging pixel region arranged along a direction crossing a moving direction of a relative position of the solid-state imaging device; and L pieces of A/D converter provided corresponding to the L pieces of imaging pixel region. Each imaging pixel region includes pixels arranged two-dimensionally to form an M-row by N-column matrix. Any one of the L pieces of A/D converter executes a dummy A/D conversion once or more times after an A/D conversion of an electric signal from a pixel of an m-th row, before an A/D conversion of an electric signal from a pixel of an (m + 1)-th row.