Optical Lens Surface Measurement Using Extended Light Source
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Solution Overview
Problem
Existing methods for measuring optical lens surfaces, particularly aspherical lenses, require complex imaging optics and are inefficient in simultaneously measuring multiple lens surfaces, leading to challenges in detecting deviations from the desired aspheric shape due to manufacturing errors.
Innovation Solution
A method using an extended light source with a vignetting field stop to generate blurred light spots on a spatially resolving detector, allowing simultaneous measurement of at least two lens surfaces without complex optics, by determining the angle between each lens surface and the optical axis through intensity distribution analysis.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If complex imaging optics are used to measure lens surfaces, then measurement precision is improved, but device complexity increases
Solution Approach 1:
The patent extracts and removes the complex imaging optics from the measurement system. Instead of using complex optics to form images of lens surfaces, the invention uses a simplified setup with an extended light source, aperture stop, and direct detection of light spots on the detector, eliminating the need for complex imaging while maintaining measurement capability
Solution Approach 2:
The patent creates a simplified optical copy of the measurement process. By using an extended light source that mimics the aperture stop's geometry and positioning it to create blurred light spots corresponding to different lens surface positions, the system achieves measurement functionality without replicating complex imaging optics
2Measurement precision
If individual lens surfaces are measured sequentially, then measurement precision is maintained, but productivity decreases
Solution Approach 1:
The patent merges multiple measurement functions into a single optical setup. By positioning the extended light source and aperture stop such that light spots from multiple lens surfaces (including both sides of a lens) are simultaneously projected onto the detector, the system measures multiple surfaces in parallel during a single rotation, eliminating sequential measurement steps
Solution Approach 2:
The patent creates a universal measurement system that can measure different lens surfaces with different curvatures (spherical and aspherical) using the same optical configuration. The extended light source and aperture stop arrangement universally handles various lens types and surface geometries without requiring separate measurement procedures
3Measurement precision
If separate imaging optics are used for each lens surface, then measurement precision is improved, but device complexity increases
Solution Approach 1:
The patent implements a universal optical system where a single imaging path handles multiple lens surfaces. The detector captures light spots from different surfaces through a unified optical arrangement, making the system multi-functional without requiring separate imaging optics for each surface
Solution Approach 2:
The patent removes the need for separate imaging optics by extracting the measurement function into a direct detection approach. The aperture stop and extended light source create distinctive light spot patterns that can be directly analyzed without additional imaging elements
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
Enables precise and rapid measurement of multiple lens surfaces, including aspherical lenses, with improved detection of decentering and lateral offsets, reducing the need for complex optical arrangements and enabling single rotation measurements of 180° for aspheres.
Implementation Method 1
an optical measuring beam is generated using an extended light source, collimated via an optical arrangement, directed onto a first lens surface of an optical lens arrangement to be measured, and detected by at least one spatially resolving optical detector after reflection from the first lens surface to be measured
Data Source
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AI summary
In a method for measuring optical lens surfaces, a measuring beam is generated using an extended light source, collimated via an optical arrangement, and detected by an optical detector after reflection from a lens surface to be measured. An aperture limiting the measuring beam, acting as a vignette field stop, is placed between the light source and the optical detector. The field stop is imaged by the measuring beam, albeit blurred, as the first light spot on the optical detector after reflection from a first lens surface. Simultaneously, the optical detector also detects at least one second light spot, which is obtained by reflection of the measuring beam from a second lens surface in the optical lens arrangement. From the intensity distribution of the two light spots, the angle of each lens surface to the optical axis of the measuring beam can be determined simultaneously for both lens surfaces.This provides a method for measuring lens surfaces of optical lens systems that does not require complex optical setups and enables rapid measurement of the lens surfaces.