Gyro Sensor Bias Voltage Adjustment for Sensitivity and Noise
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Solution Overview
Problem
Existing gyro sensors face challenges in adjusting sensitivity without compromising the signal-to-noise (S/N) ratio, as increasing sensitivity leads to amplified noise.
Innovation Solution
The gyro sensor design includes a substrate, oscillation members, fixed and movable driving electrodes, fixed and movable detection electrodes, and a bias voltage application unit that adjusts the bias voltage based on stored information, allowing for sensitivity adjustment while minimizing the impact on the S/N ratio.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the gain of the sensitivity adjustment circuit is increased to achieve higher output sensitivity, then the sensitivity is improved, but noise is amplified causing deterioration of the S/N ratio
Solution Approach 1:
The patent changes the bias voltage parameter applied to the detection electrode to adjust output sensitivity. By varying the bias voltage (e.g., from 5V to 15V as shown in the embodiment), the sensitivity is adjusted without requiring signal amplification, thereby avoiding noise amplification and maintaining a high S/N ratio.
2Measurement precision
If sensitivity adjustment is performed by amplifying the output signal, then the output sensitivity is improved, but the S/N ratio deteriorates due to amplified noise
Solution Approach 1:
The patent applies preliminary action by adjusting the bias voltage before signal detection and processing. By pre-adjusting the operating point through bias voltage control, the sensitivity is optimized at the source rather than through post-detection amplification, preventing noise amplification and maintaining signal quality throughout the measurement process.
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 enables the gyro sensor to adjust sensitivity effectively without significantly decreasing the S/N ratio, resulting in a highly reliable electronic device and mobile apparatus operation.
Implementation Method 1
a fixed driving electrode that is fixed to the substrate and oscillates the oscillation member; a movable driving electrode that extends from the oscillation member and oscillates the oscillation member
Implementation Method 2
a fixed detection electrode that is fixed to the substrate and detects a signal that varies according to oscillation of the oscillation member; a movable detection electrode that extends from the oscillation member and detects a signal that varies according to oscillation of the oscillation member
Implementation Method 3
a bias voltage application unit that applies a bias voltage to the oscillation member; The bias voltage application unit sets a value of the bias voltage based on information stored in the storage unit
Data Source
AI summary
A gyro sensor includes a substrate, an oscillation member, fixed driving electrodes and a movable driving electrode that oscillate the oscillation member, fixed detection electrodes and a movable detection electrode that detect a signal that varies in accordance with oscillation by Coriolis' force of the oscillation member, a bias voltage application unit that applies a bias voltage to the oscillation member, and a storage unit, and the bias voltage application unit sets a value of the bias voltage based on information stored in the storage unit.