Signal Processing Device for Camera Shake Correction
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Solution Overview
Problem
Existing camera shake correction systems face challenges in accurately calculating blurring due to offset errors in gyro sensor signals, leading to inaccurate correction and generation of low-frequency blurring residues when using high-pass filter processing.
Innovation Solution
A signal processing device that selectively outputs either high-pass or non-high-pass filtered signals based on exposure time and elapsed time for calculation, switching between them to minimize offset effects and blurring residues, using threshold values set according to cut-off frequency and offset of the blurring detection sensor.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If high-pass filter processing is applied to gyro sensor signals to reduce offset effects, then offset errors are reduced, but low-frequency blurring residues are generated and measurement precision deteriorates
Solution Approach 1:
The patent dynamically switches between high-pass filter processing and non-high-pass filter processing based on exposure time duration. For short exposure times, high-pass filtering is applied to reduce offset errors. For long exposure times, non-high-pass filtering is used to avoid low-frequency blurring residues. This dynamic adaptation resolves the contradiction by selecting the appropriate processing mode for each specific condition.
Solution Approach 2:
The patent changes the filtering parameter (high-pass vs non-high-pass) based on the exposure time parameter. By setting threshold values for exposure time, the system adjusts the signal processing approach to optimize blurring calculation accuracy while minimizing harmful residues under different operating conditions.
2Object-generated harmful factors
If non-high-pass filter processing is used to avoid low-frequency blurring residues, then blurring residues are reduced, but offset errors increase and measurement precision deteriorates
Solution Approach 1:
The system dynamically selects the filtering approach based on exposure time characteristics. For long exposure times where low-frequency residues are less problematic, non-high-pass filtering is used to maintain signal accuracy. For short exposure times where offset errors dominate, high-pass filtering is applied. This dynamic selection resolves the contradiction adaptively.
Solution Approach 2:
The filtering parameter is changed according to the exposure time parameter. By comparing the actual exposure time against predetermined thresholds, the system switches between filtering modes to optimize the balance between reducing offset errors and avoiding low-frequency residues.
3Measurement precision
If high-pass filter processing is used for all exposure times, then offset errors are reduced, but calculation complexity increases and processing time increases
Solution Approach 1:
The patent segments the exposure time range into different intervals based on threshold values. Each segment is assigned a specific filtering strategy (high-pass for short exposures, non-high-pass for long exposures). This segmentation avoids applying complex high-pass filtering unnecessarily to all cases, thereby reducing overall calculation time while maintaining accuracy where needed.
Solution Approach 2:
Instead of applying high-pass filtering universally (excessive action), the patent applies it only partially - specifically to short exposure times where offset errors are the dominant problem. For long exposure times, simpler non-high-pass filtering suffices, reducing unnecessary computational overhead.
Data Source
AI summary
Provided are a signal processing device, a signal processing method, a signal processing program, an imaging apparatus, and a lens apparatus capable of accurately calculating an amount of blurring on the basis of a signal which is output from a blurring detection sensor. The signal processing device processes a signal which is output from a blurring detection sensor in progress of exposure of an imaging element. The signal processing device includes a processor. The processor is configured to perform processing of generating a second signal obtained by performing high-pass filter processing on a first signal which is output from the blurring detection sensor; and processing of calculating an amount of blurring on the basis of the first signal or the second signal.