Image Sensor PCB Wiring Layout for Power Supply Noise Reduction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Image capturing devices experience noise in their signals due to magnetic fields generated by electric current flowing through power supply wiring, particularly in compact designs where the image capturing device is physically close to the power supply wiring, leading to reduced signal quality and S/N ratio.
Innovation Solution
The image capturing device unit is designed with power supply wiring arranged on a different surface from the image capturing device, with specific routing patterns that avoid parallel alignment with pixel or signal processing sections, and divided into multiple power supply wiring portions to minimize current variation and magnetic interference.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If the image capturing device is directly mounted on a printed circuit board to reduce size and thickness, then the device size and thickness are reduced, but the image capturing device becomes physically close to power supply wiring and is susceptible to magnetic fields generated by electric current, causing noise in image signals
Solution Approach 1:
The patent applies dimensionality change by routing power supply wiring on the back surface of the printed circuit board, perpendicular to the image capturing device mounting surface. This spatial reconfiguration in the third dimension (Z-axis) separates the power supply wiring from the sensitive image capturing device, reducing magnetic field interference while maintaining compact form factor. The wiring extends from the front surface through to the back surface of the board, creating physical distance between noise sources and signal components.
Solution Approach 2:
The patent segments the power supply wiring into multiple portions: first power supply wiring on the front surface, second power supply wiring on the back surface, and connection wiring connecting them through the board. This segmentation allows the power supply path to be distributed across different spatial zones, reducing concentrated current density and magnetic field strength at any single location near the image capturing device.
2Area of stationary object
If signal processing sections are laminated with pixel portions to reduce area, then the device area is reduced, but noise is generated in captured images due to magnetic field influence from power supply wiring of the signal processing sections
Solution Approach 1:
The patent extracts the power supply wiring for signal processing sections from the front surface where it would be close to pixel portions, and relocates it to the back surface of the printed circuit board. This extraction removes the harmful magnetic field source from proximity to sensitive areas, allowing compact lamination of signal processing sections with pixel portions while maintaining image quality.
3Measurement precision
If the number of pixels and readout speed are increased to improve image quality, then image quality is improved, but current variation per period of horizontal synchronization signal becomes larger, reducing S/N ratio due to magnetic field from current variation
Solution Approach 1:
The patent routes power supply wiring for high-speed readout circuits on the back surface of the printed circuit board, perpendicular to the front surface where pixel signals are read out. This dimensional separation reduces magnetic field coupling between power supply current variations and signal lines, maintaining high S/N ratio even when operating at increased readout speeds with higher current variation.
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 effectively reduces noise in image signals and current variation, maintaining high signal quality even in compact designs by minimizing the impact of magnetic fields on the image capturing device.
Implementation Method 1
noise generated in image signals due to a magnetic field generated by electric current flowing through a power supply wiring
Implementation Method 2
magnetic field generated by electric current flowing through power supply wiring arranged in the vicinity of the image capturing device
Data Source
AI summary
An image capturing device unit capable of reducing noise generated in image signals due to power supply. A pixel portion of an image capturing device has pixels arranged in a matrix in first and second directions perpendicular to each other. Output lines are arranged in parallel to the second direction, for reading out pixel signals in the second direction for each of groups of pixels arranged in the first direction. A power supply wiring is arranged on a substrate surface different from a surface on which the image capturing device is mounted and supplies power to the device, and includes a draw-out wiring portion arranged to be routed along the second direction in a pixel portion area which overlaps the pixel portion when the device is projected onto the substrate in a third direction perpendicular to the first and the second directions.