Dual Camera Module Time-Division Control for Signal Interference
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Solution Overview
Problem
Dual camera modules with voice coil motor actuators in mobile devices experience signal interference between adjacent cameras, leading to errors in auto-focus positioning due to shared magnetic forces, which affects the accuracy and speed of auto-focus functions.
Innovation Solution
A dual camera module control method that identifies and manages the sensor types of each camera, controlling their operation times differently if they share the same sensor type to minimize interference, and includes an optical image stabilization compensator and a damper to reduce natural frequency and enhance auto-focus precision.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a hall sensor is used in each camera module for auto-focus sensing, then auto-focus function is enabled, but signal interference occurs between adjacent camera modules due to shared magnetic forces
Solution Approach 1:
The controller alternately drives the first and second camera modules at different time zones. When the first camera module is driven, the second camera module is not driven, and vice versa. This periodic operation prevents simultaneous operation of both camera modules, thereby eliminating signal interference between them while maintaining auto-focus functionality in each module.
2Productivity
If both camera modules operate simultaneously, then productivity is improved, but measurement precision of lens movement position deteriorates due to signal interference
Solution Approach 1:
The controller implements time-division operation where the first camera module operates during a first time zone and the second camera module operates during a second time zone. This periodic action ensures that only one camera module is active at any given time, preventing signal interference and ensuring accurate measurement of lens movement position, while maintaining overall productivity through continuous alternating operation.
3Volume of moving object
If camera modules are miniaturized for mobile devices, then device portability is improved, but auto-focus performance deteriorates due to space constraints on actuator characteristics
Solution Approach 1:
The dual camera module system is segmented into independently controllable units with distinct operation time zones. By dividing the operation into separate time zones for each camera module, the system maintains reliable auto-focus performance in each miniaturized module without requiring larger actuators, as the alternating operation prevents signal interference that would otherwise degrade performance in compact configurations.
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 effectively cancels signal interference between cameras, ensuring accurate and fast auto-focus performance by coordinating the operation of cameras based on their sensor types and using stabilization and damping mechanisms to improve focus accuracy and speed.
Implementation Method 1
the camera module based on the voice coil motor actuator configures a magnetic circuit by arranging a permanent magnet in a fixed module of the camera module and attaching a coil to a lens module, which will be driven, whereby the lens module is driven by Lorentz's force that flows in the coil
Implementation Method 2
the voice coil motor type camera module may calculate an optimal auto-focus value of the lens module by extracting a difference of magnetic flux values according to displacement of the lens module using a hall sensor
Implementation Method 3
a damper is arranged between a spring and a lens module to reduce natural frequency of the spring, whereby an error in auto-focus may be avoided and auto-focus time may be reduced
Data Source
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AI summary
A dual camera module that includes a voice coil motor actuator and a method for controlling the same are disclosed. The dual camera module comprises a first camera including a first lens module; a second camera including a second lens module, arranged to adjoin the first camera; and a controller for controlling the first camera and the second camera, wherein the controller identifies whether the first camera includes a first sensing module for sensing movement of the first lens module if a camera execution command is received, identifies whether the second camera includes a second sensing module for sensing movement of the second lens module if the first camera includes the first sensing module, identifies whether the first sensing module of the first camera and the second sensing module of the second camera have the same type as each other if the second camera includes the second sensing module, and controls the first camera and the second camera at different time zones if the first sensing module and the second sensing module have the same types as each other.