Vibration Prevention Control Circuit Phase Delay All-Pass Filter
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Solution Overview
Problem
Existing vibration prevention control circuits in imaging devices face challenges in accurately comparing angular velocity signals from gyro sensors to position signals from hall elements due to phase shifts, leading to incomplete vibration correction and potential lens position deviations.
Innovation Solution
A vibration prevention control circuit that includes an analog-to-digital converter, a phase delay circuit using an all-pass filter to correct the phase shift in angular velocity signals, and digital processing to generate precise control signals for lens movement, ensuring accurate alignment of the lens with the imaging element.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If phase shift correction is not applied to angular velocity signals, then the circuit structure remains simple, but vibration correction accuracy deteriorates due to phase mismatch between angular velocity signals and position signals
Solution Approach 1:
An all-pass filter is introduced as an intermediary component to correct the phase shift in angular velocity signals. The all-pass filter acts as a mediator that adjusts the phase of the angular velocity signal without altering its amplitude, enabling accurate comparison with position signals from hall elements. This resolves the phase mismatch problem while maintaining a relatively simple circuit structure.
Solution Approach 2:
The phase of the angular velocity signal is adjusted by changing the frequency response characteristics through the all-pass filter. By modifying the phase parameter of the signal across different frequencies, the system achieves accurate synchronization between angular velocity and position signals, thereby improving vibration correction accuracy without adding complex circuitry.
2Measurement precision
If analog processing is used for vibration correction, then the circuit structure is simple, but signal processing precision deteriorates due to phase shifts and noise
Solution Approach 1:
The system replaces purely analog signal processing with a hybrid approach that incorporates digital signal processing. Angular velocity signals are converted to digital domain where phase correction and noise filtering can be performed with higher precision using digital algorithms, while position signals from hall elements remain analog. This substitution enables more accurate signal processing while keeping the overall system architecture relatively simple.
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 solution effectively reduces the influence of hand vibrations on image quality by accurately compensating for phase shifts in angular velocity signals, ensuring stable image capture and minimizing lens position deviations within its movable range.
Implementation Method 1
a phase delay circuit which delays a phase of the output signal of the vibration detection element without changing an intensity in a predetermined frequency band
Implementation Method 2
at least one analog-to-digital converter circuit which converts an output signal of a vibration detection element which detects vibration of the imaging device and an output signal of a position detection element which detects a position of the optical component, into digital signals
Implementation Method 3
A gyro sensor may be employed as the vibration detection element 106. The vibration detection element 106 generates an angular velocity signal corresponding to the vibration applied to the imaging device
Implementation Method 4
A hall element may be used as the position detection element 102. The hall element produces an inductive current corresponding to an absolute position of the lens and outputs a voltage signal
Implementation Method 5
A voice coil motor may be used as the lens driving element 104. The vibration prevention control circuit 100 controls a position of a movable coil of the voice coil motor, that is, a position of the lens with respect to an optical axis
Data Source
AI summary
A vibration prevention control circuit is provided, comprising at least one analog-to-digital converter circuit that converts an output signal of a vibration detection element which detects vibration of an imaging device, and an output signal of a position detection element which detects a position of an optical component, into digital signals, and a logic circuit that generates a control signal which drives the optical component, based on the output signal of the vibration detection element which is digitized by the analog-to-digital converter circuit and the output signal of the position detection element which is digitized by the analog-to-digital converter circuit, wherein a phase delay circuit (all-pass filter) is provided that delays a phase of the output signal of the vibration detection element without changing an intensity in a predetermined frequency band and outputs the processed signal.