Camera Actuator Position Detection Without Hall Sensors
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Solution Overview
Problem
Existing camera module actuators rely on hall sensors to detect magnet position, which increases manufacturing costs and reduces space efficiency.
Innovation Solution
An actuator that uses a magnet, driving coil, and a position detector generating oscillation signals to detect the magnet's position without a hall sensor, allowing for precise position detection using count values and digital signal corrections based on temperature changes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a hall sensor is used to detect magnet position, then position detection can be achieved, but manufacturing cost increases and space efficiency decreases
Solution Approach 1:
The patent extracts the position detection function from the hall sensor and implements it using the existing magnet and coil components. The oscillation signal generation capability is obtained by removing unnecessary parts and utilizing the inherent electromagnetic interaction between the magnet and coil, thereby eliminating the need for separate hall sensors and reducing device complexity.
Solution Approach 2:
The magnet and coil components serve dual purposes: they generate driving force for lens barrel movement and simultaneously generate oscillation signals for position detection. This multi-functionality eliminates the need for dedicated hall sensors, reducing both manufacturing cost and space requirements while maintaining precise position detection capability.
2Measurement precision
If hall sensors are used for position detection, then position information can be obtained, but the actuator occupies more space and costs more to manufacture
Solution Approach 1:
The patent merges the position detection function with the existing electromagnetic driving components. The oscillation signal generated by the magnet-coil interaction serves both as a driving mechanism and a position detection signal, consolidating multiple functions into a single integrated system that reduces the overall actuator footprint.
Solution Approach 2:
The magnet and coil system serves itself by generating oscillation signals that provide position detection information without requiring external hall sensors. The same electromagnetic interaction that produces mechanical motion also produces detectable oscillation signals, allowing the system to self-diagnose its position state.
3Ease of manufacture
If traditional position detection methods are used, then manufacturing cost increases, but the patent eliminates hall sensors to reduce cost
Solution Approach 1:
The patent replaces expensive hall sensors with a cost-effective oscillation signal generation method using existing magnet and coil components. By utilizing the inherent electromagnetic properties of these components, the system achieves position detection without requiring additional expensive sensing elements, thereby reducing manufacturing cost.
Solution Approach 2:
The patent changes the detection parameter from magnetic field strength (requiring hall sensors) to oscillation frequency and amplitude (detectable through existing coil circuits). This parameter transformation allows position detection using the existing electromagnetic driving components, eliminating the need for expensive hall sensors while maintaining detection accuracy.
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 reduces manufacturing costs and improves space efficiency by eliminating the need for hall sensors while maintaining precise position detection, even in varying environmental conditions.
Implementation Method 1
an inductor configured to generate the oscillation signal and determine the frequency of the oscillation signal. The inductor may be disposed in a range of a magnetic field of the magnet.
Implementation Method 2
a driving coil disposed at a proximity of the magnet; a driver configured to apply a driving signal to the driving coil to move the lens barrel along an optical axis
Data Source
AI summary
An actuator includes a magnet, a driving coil, a driver, and a position detector. The magnet is disposed on one surface of a lens barrel. The driving coil is disposed at a proximity of the magnet. The driver is configured to apply a driving signal to the driving coil to move the lens barrel along an optical axis. The position detector is configured to generate an oscillation signal of which a frequency is changed based on movement of the magnet and configured to compare oscillation signals generated in a first position and a second position of the lens barrel to detect a present position of the lens barrel.