Camera Module Actuator Position Detection via Oscillating Signal Frequency
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Solution Overview
Problem
Existing camera module actuators rely on hall sensors to detect magnet position, which can be costly and occupy space, limiting precision and efficiency.
Innovation Solution
A camera module actuator that uses a magnet, coil, driver, and position estimating processor to detect magnet position through frequency variations of an oscillating signal, eliminating the need for a hall sensor by converting inductance changes into frequency, allowing precise position estimation without additional hardware.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a hall sensor is used to detect magnet position, then position detection capability is provided, but manufacturing cost increases and device space is occupied
Solution Approach 1:
The patent replaces the mechanical/electronic hall sensor system with an oscillating circuit system that uses electromagnetic principles. The inductor in the oscillating circuit detects changes in magnetic field strength caused by magnet movement, converting these changes into frequency variations of the oscillating signal, thereby eliminating the need for a separate hall sensor while maintaining position detection capability
Solution Approach 2:
The oscillating circuit performs multiple functions: it generates an oscillating signal for driving the coil and simultaneously serves as a sensing element for detecting magnet position through inductance changes. This multi-functionality eliminates the need for separate dedicated position sensing hardware, reducing device complexity
2Measurement precision
If a hall sensor is used to detect magnet position, then position detection capability is provided, but manufacturing cost increases
Solution Approach 1:
The patent merges the position sensing function into the existing oscillating circuit by utilizing the inductor's sensitivity to magnetic field changes. The same circuit that generates oscillations also detects position through frequency variations, eliminating the need for separate hall sensor components and reducing manufacturing costs
Solution Approach 2:
The oscillating circuit serves itself by using its own inductor to detect position changes. The inductor's inductance changes automatically reflect magnet position, and these changes are directly converted into frequency variations that the circuit itself can measure, eliminating the need for external sensing components
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 solution enables precise magnet position detection within the camera module, reducing manufacturing costs and improving space efficiency by eliminating the need for a hall sensor while maintaining accurate autofocusing capabilities.
Implementation Method 1
a position estimating processor configured to estimate a position of the magnet from an oscillating signal, wherein a frequency of the oscillating signal varies according to a movement of the magnet
Implementation Method 2
an inductor configured to determine the frequency of the oscillating signal; The inductor may be located within a range of a magnetic field of the magnet
Implementation Method 3
a coil disposed to face the magnet; a driver configured to move the magnet by applying a driving signal to the coil
Data Source
AI summary
A camera module actuator includes, a magnet, a coil, a driver, and a position estimating processor. The coil is disposed to face the magnet. The driver is configured to move the magnet by applying a driving signal to the coil. The position estimating processor is configured to estimate a position of the magnet from an oscillating signal. A frequency of the oscillating signal varies according to a movement of the magnet.