Camera Module Position Sensing With Shared Amplifier Noise Control
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Solution Overview
Problem
Existing camera modules face challenges in accurately adjusting the position of the lens barrel due to ambient noise and high-frequency noise properties, which are not adequately addressed by conventional position sensors and signal processing methods.
Innovation Solution
A camera module design that incorporates a plurality of position sensors interconnected with an amplifier and an analog-to-digital converter, allowing for differential signal input and minimizing noise interference, thereby enhancing position detection range and accuracy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If separate amplifiers are used for each sensor unit in a multi-channel position sensor system, then signal amplification quality is improved, but device complexity and manufacturing cost increase
Solution Approach 1:
The patent merges multiple separate amplifier circuits into a single shared amplifier that serves all sensor units. The amplifier is configured to sequentially connect to different sensor units through a multiplexer, providing signal amplification for all channels using one amplifier component, thereby reducing device complexity and cost while maintaining amplification quality.
Solution Approach 2:
The single amplifier is designed to perform multiple functions by serving different sensor units at different time intervals. Through the control unit's switching mechanism, the same amplifier amplifies signals from various sensor units sequentially, making the amplifier a universal component that handles multiple sensing tasks.
2Measurement precision
If multiple separate ADCs are used for each sensor unit, then conversion precision is improved, but device complexity and power consumption increase
Solution Approach 1:
The patent combines multiple separate ADC circuits into a single shared ADC that converts analog signals from all sensor units. The ADC is controlled to process signals sequentially from different sensor units through a multiplexer, achieving precise analog-to-digital conversion for all channels using one ADC component, thereby reducing device complexity and power consumption.
3Device complexity
If a shared amplifier and ADC are used for multiple sensor units, then device complexity is reduced, but signal processing time increases due to sequential processing
Solution Approach 1:
The control unit implements periodic sequential switching to allocate the shared amplifier and ADC to different sensor units in a systematic cycle. Each sensor unit receives dedicated processing time in a repeating sequence, ensuring that all channels are serviced regularly while maintaining efficient use of the shared resources.
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 design achieves wider detection range and improved noise resistance, optimizing position detection in various environments by minimizing offset noise and reducing the number of connections to the printed circuit board, thus ensuring accurate lens positioning.
Implementation Method 1
a position sensor unit for detecting the position of the lens assembly
Data Source
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Figure 3b
AI summary
A camera module, according to one embodiment, comprises: a lens assembly; a lens driving unit for moving the lens assembly in the direction of the optical axis; a position sensor unit for detecting the position of the lens assembly; and a control unit for, on the basis of the position of the lens assembly detected by the position sensor unit, outputting, to the lens driving unit, a drive signal for moving the lens assembly to a target position, wherein the position sensor unit comprises a plurality of sensor units which have at least one output terminal connected with each other, an amplifier which is commonly connected with the plurality of sensor units, and an analog-digital converter which is connected to the amplifier.