Position Output Unit Pulse Scaling for Lens Apparatus
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Lens apparatuses with long movable ranges or high-resolution position detectors exceed the maximum pulse count value of virtual systems, preventing accurate determination of movable optical member positions without time-consuming calibration.
Innovation Solution
A position output unit that generates a second pulse train signal based on the first pulse train signal from a position detector, ensuring the total pulse number over the movable range is within the virtual system's maximum pulse count value, allowing accurate position determination without extensive calibration.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the movable range of the movable optical member is increased or the resolution of the position detector is improved, then the position detection precision is improved, but the total pulse number exceeds the maximum pulse count value of the virtual system
Solution Approach 1:
The patent divides the pulse train signal into multiple segments by inserting pulse trains with different pulse numbers corresponding to different movable ranges. The position detector outputs a first pulse train signal, and a pulse generator generates second pulse train signals with segmented pulse counts that are converted to position information within the virtual system's maximum pulse count value, thereby resolving the contradiction between high position detection precision and excessive total pulse number.
2Measurement precision
If the total pulse number exceeds the maximum pulse count value, then the position detection range and resolution are improved, but the virtual system cannot determine the position correctly without calibration
Solution Approach 1:
The patent performs preliminary normalization of the pulse train signal by the lens apparatus before transmission to the virtual system. The pulse generator pre-processes the first pulse train signal from the position detector to generate second pulse train signals with normalized pulse counts, eliminating the need for calibration operations in the virtual system and enabling direct position determination without time loss.
3Measurement precision
If the position detector has high resolution, then the position information accuracy is improved, but the pulse count exceeds the virtual system's maximum pulse count value
Solution Approach 1:
The patent changes the parameter of pulse number by generating multiple second pulse train signals with different pulse numbers corresponding to different movable ranges of the movable optical member. The pulse generator selects and outputs the appropriate pulse train signal based on the actual movable range, ensuring that the pulse count remains within the virtual system's maximum pulse count value while maintaining high position information accuracy from the high-resolution position detector.
Data Source
AI summary
A position output unit according to the invention includes a pulse generator that generates a second pulse train signal on a basis of a first pulse train signal output from a position detector that generates the first pulse train signal including a number of pulses representing the displacement amount of a movable member. The pulse generator generates the second pulse train signal in such a way that a second total pulse number defined as a total number of pulses in the second pulse train signal corresponding to a displacement amount of the movable member over an entirety of the movable range is smaller than or equal to a first total pulse number defined as a total number of pulses in the first pulse train signal corresponding to the entirety of the movable range of the movable member.