Asymmetrical Lead Electrodes for Gyro Sensor Signal Stability
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In small cantilevered oscillation type gyro sensors, the close proximity of wiring for driving and detecting Coriolis force leads to leak currents between lead electrodes, causing signal imbalance and increased Power Supply Rejection Ratio (PSRR), which deviates detection signals from specifications.
Innovation Solution
The design includes asymmetrical lead electrodes with equal areas to minimize leak current differences between detection electrodes, allowing for improved positioning flexibility and reduced PSRR, enabling more efficient manufacturing and signal stability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If the wiring for driving and detecting Coriolis force are disposed closely in small cantilevered oscillation type gyro sensors, then the device size is reduced, but leak currents occur between lead electrodes causing signal imbalance and increased PSRR
Solution Approach 1:
The patent applies asymmetry by making the first and second lead electrodes have different shapes while maintaining equal areas. Specifically, the first lead electrode has a first shape and the second lead electrode has a second shape that is different from the first shape, but both have substantially the same area. This asymmetric design with equal areas minimizes leak current differences between the detection lead electrodes while allowing compact wiring arrangement, thus resolving the contradiction between device size reduction and signal accuracy maintenance.
2Ease of manufacture
If symmetrical lead electrodes are used, then manufacturing is simpler, but positioning flexibility is reduced and PSRR increases due to leak current imbalances
Solution Approach 1:
The patent uses asymmetric lead electrode shapes that can be easily manufactured using standard photolithography techniques. The asymmetric design provides positioning flexibility by allowing the lead electrodes to be optimally positioned relative to the drive electrode and detection electrodes, while the equal area constraint maintains manufacturing simplicity. This resolves the contradiction between manufacturing ease and positioning flexibility.
Solution Approach 2:
The patent changes the geometric parameters of the lead electrodes by specifying that they have different shapes but equal areas. This parameter change (from symmetric to asymmetric with equal area constraint) allows optimization of positioning flexibility and PSRR while maintaining ease of manufacture through standard fabrication processes.
3Ease of operation
If the areas of first and second lead electrodes are different, then positioning is easier, but leak current differences increase causing detection signal imbalance
Solution Approach 1:
The patent applies asymmetry in shape while maintaining equality in area for the lead electrodes. The first lead electrode has a first shape and the second lead electrode has a second shape, and these shapes can be positioned flexibly to optimize ease of operation. However, the constraint that both areas be substantially equal ensures that leak current differences are minimized, maintaining signal balance. This resolves the contradiction between positioning ease and signal balance.
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 design effectively reduces leak current differences and PSRR, ensuring detection signal accuracy and stability, while allowing for increased production efficiency and flexibility in manufacturing multiple piezoelectric devices from a single substrate.
Implementation Method 1
The piezoelectric member oscillates the arm portion by piezoelectric operation of the piezoelectric member
Implementation Method 2
The first detection electrode and the second detection electrode detect a Coriolis force which occurs in the arm portion which oscillates
Data Source
AI summary
A piezoelectric device is disclosed. A substrate has an arm portion. A piezoelectric member is disposed on the substrate. A drive electrode oscillates the arm portion by a piezoelectric operation of the piezoelectric member. First and second detection electrodes detect a Coriolis force from the oscillating arm portion. A first lead electrode having a first area is disposed on the substrate and connected to the first detection electrode and connects the first detection electrode to the outside. A second lead electrode has a second area substantially the same as the first area. The second lead electrode is disposed on the substrate asymmetrical to the first lead electrode with respect to an axis in a longitudinal direction of the arm portion and connected to the second detection electrode. The second lead electrode connects the second detection electrode to the outside. A third lead electrode connects the drive electrode to the outside.