Microphone Chip Grating Group for Noise Reduction
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Solution Overview
Problem
Existing microphone chips in optical microphones face challenges due to the complexity of manufacturing processes, increased mechanical and circuit noise, and compromised sound pickup performance, primarily because of the need for a driving structure and control circuit to adjust the distance between the reflector and the grating.
Innovation Solution
The microphone chip design eliminates the need for a driving structure and control circuit by using a grating group with varying distances between the gratings and the reflector, allowing for adjustments without these components. This simplified structure reduces manufacturing complexity and noise, enhancing sound pickup performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a driving structure and driving control circuit are disposed in the microphone chip to adjust the distance between the reflector and the grating, then the sound pickup performance can be improved, but the manufacturing process complexity and noise increase
Solution Approach 1:
The patent extracts and removes the driving structure and driving control circuit from the microphone chip. Instead of actively adjusting the distance between the reflector and grating using these components, the design uses a fixed grating group with pre-configured different distances, thereby simplifying the manufacturing process while maintaining sound pickup performance through passive optical path difference generation
Solution Approach 2:
The grating group is pre-configured with multiple gratings at different distances from the reflector during the manufacturing process. This preliminary arrangement of varying distances eliminates the need for post-manufacturing adjustment mechanisms, reducing manufacturing complexity while ensuring the optical path difference is already optimized for sound pickup functionality
2Adaptability or versatility
If a driving structure and driving control circuit are disposed in the microphone chip, then the distance between the reflector and grating can be adjusted, but mechanical noise and circuit noise increase
Solution Approach 1:
The patent removes the driving structure and driving control circuit that would generate mechanical noise and circuit noise. The distance adjustment capability is replaced by a fixed grating group configuration where different distances are pre-established, eliminating the source of harmful noise while maintaining the functional capability of creating optical path differences for sound detection
Solution Approach 2:
The grating group is designed to be self-configured with different distances from the reflector during manufacturing, eliminating the need for active control circuits and driving structures. The system uses its own structural configuration to provide the necessary distance variations without requiring external control mechanisms that would generate noise
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 simplifies the manufacturing process, reduces mechanical and circuit noise, and improves sound pickup performance by stabilizing the microphone chip in a linear working area, thereby enhancing detection sensitivity and signal-to-noise ratio.
Implementation Method 1
One part of light emitted by the optical emitter is reflected on a lower surface of the grating; and one part of the light emitted by the optical emitter is transmitted to the reflector after passing through slits of the grating, and is reflected on an upper surface of the grating again by the reflector
Implementation Method 2
the light having an optical path difference is diffracted by the grating and a phase of the light is interfered
Implementation Method 3
the light having an optical path difference is diffracted by the grating and a phase of the light is interfered
Implementation Method 4
After receiving diffracted light of the grating, the optical detector converts an optical signal into an electrical signal
Implementation Method 5
When sound pressure acts on the diaphragm, the diaphragm is deformed, and the reflector under the diaphragm is driven to move downward
Data Source
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AI summary
This application discloses a microphone chip, a microphone, and a terminal device. The microphone chip, the microphone, and the terminal device may be used in a mobile phone, a voice recorder, and another device that needs to perform sound collection. The microphone chip includes: a substrate and a diaphragm that are disposed oppositely; a reflector located on a side that is of the diaphragm and that is close to the substrate; a grating group located between the substrate and the diaphragm; and an optical emitter and an optical detector that are located between the substrate and the grating group, where the grating group includes a plurality of gratings, and distances between at least two gratings in the plurality of gratings and the reflector are different. This application reduces difficulty and complexity of a manufacturing process, and reduces mechanical noise and circuit noise.