Lens Surface Profile Measurement Without Reference Balls
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing methods for measuring front and back surfaces of lenses, such as those manufactured using metal molds, often result in optical axis misalignment due to precision and displacement issues, and require high-precision reference balls, leading to high costs and measurement errors.
Innovation Solution
A method that measures front and back surfaces of a target object by moving a probe relative to the object, reversing the object's posture to align with the probe, and comparing contour data to determine measurement positions, allowing for accurate profiling without reference balls, using a vibratory probe for constant pressure contact and minimizing external influences.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If high-precision reference balls are used to measure front and back surfaces, then measurement precision is improved, but device complexity and cost increase
Solution Approach 1:
The patent removes the reference balls from the measurement system entirely. Instead of using reference balls to establish measurement positions, the invention directly measures the contour of the lens itself and uses the measured data to determine both surface profiles and optical axis alignment, thereby eliminating the need for complex reference ball preparation and positioning systems
Solution Approach 2:
The lens being measured serves its own purpose by providing the reference information needed for measurement. The contour data of the lens itself is used to determine the measurement positions and calculate the profiles of both front and back surfaces, making the measured object the reference standard rather than requiring external reference balls
2Measurement precision
If reference balls are used to establish measurement positions, then measurement precision is improved, but preparation cost increases
Solution Approach 1:
The invention extracts and eliminates the reference balls from the measurement process. By directly measuring the lens contour and using the obtained data to determine measurement positions, the system removes the need for expensive high-precision reference balls and their associated preparation procedures
Solution Approach 2:
The patent replaces expensive, high-precision reference balls with a simple, reusable measurement method that uses the lens itself as the reference. This eliminates the need for costly reference ball preparation while maintaining measurement accuracy through direct contour measurement and data processing
3Ease of operation
If only exposed portions of reference balls are measured, then measurement process is simplified, but measurement precision deteriorates
Solution Approach 1:
The patent performs preliminary contour measurement of the entire lens before proceeding to surface profile measurement. This preliminary action establishes the complete geometric reference frame and measurement positions, ensuring that subsequent surface measurements are accurate and properly positioned, thereby avoiding the precision losses associated with measuring only exposed portions
Data Source
AI summary
A method of measuring a front surface profile and a back surface profile of a target object includes: mounting the target object in such a posture that a first measuring surface (front surface) is measurable by a probe; first measuring a contour of the target object; measuring the first measuring surface of the target object; reversing the target object; second measuring the contour of the target object with the reversed posture of the target object being maintained; obtaining a measurement position of a second measuring surface by comparison of contour data obtained through the first and second measuring of the contour, the measurement position of the second measuring surface corresponding to a measurement position of the first measuring surface at which the measuring of the first measuring surface is conducted; and measuring a profile of the second measuring surface along the obtained measurement position of the second measuring surface.