Spectacle Lens Positioning Using Permanent Markings and Retroreflection
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Solution Overview
Problem
Existing methods for determining the position and orientation of spectacle lenses on holders, particularly with progressive lenses, face challenges due to the absence of standard-defined reference points and the complexity of applying non-permanent markings, leading to potential centering and orientation errors that affect the optical performance and usability of glasses.
Innovation Solution
A method that uses iterative calculations based on apparent positions of permanent markings and additional marking-independent information, such as holding characteristics and reflex positions, to accurately determine the position and orientation of spectacle lenses, allowing for precise alignment and application of stamps even when lenses are tilted or twisted.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If lensmeter is used to determine reference points on progressive lenses, then measurement process is simplified, but measurement precision deteriorates because progressive lenses lack standard-defined reference points
Solution Approach 1:
The patent uses permanent markings (engravings) on the lens as reference copies that define the coordinate system. These markings serve as immutable reference points that can be detected by imaging devices, replacing the need for lensmeter measurements while providing higher precision for progressive lenses.
Solution Approach 2:
The patent introduces permanent markings as an intermediary element between the lens and the measurement system. These markings act as a mediator that provides detectable reference points without requiring direct optical measurement through the lens, thus solving the reference point problem for progressive lenses.
2Productivity
If stamp is applied without accurate position and orientation determination, then application speed increases, but manufacturing precision deteriorates due to centering and orientation errors
Solution Approach 1:
The patent performs preliminary determination of lens position and orientation using imaging devices and permanent markings before the stamp application process. This pre-measurement step ensures accurate alignment information is available, allowing precise stamp application without compromising speed.
Solution Approach 2:
The system uses imaging devices to capture the position of permanent markings and provides feedback about lens position and orientation. This feedback loop enables real-time adjustment and precise positioning of the stamp application, ensuring manufacturing precision while maintaining productivity.
3Measurement precision
If iterative calculation method is used to determine lens position and orientation, then measurement precision improves, but loss of time increases due to multiple calculation steps
Solution Approach 1:
The patent performs preliminary capture of permanent marking positions using imaging devices before iterative calculations. This pre-capture step provides initial data that reduces the number of iterative steps needed, thereby minimizing calculation time while maintaining high measurement precision.
Solution Approach 2:
The system uses digital images of permanent markings as copies of the reference coordinate system. These image copies can be processed efficiently through iterative algorithms, providing both high precision and relatively fast processing compared to traditional measurement methods.
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
This approach enhances the accuracy and speed of determining the lens position and orientation, enabling precise alignment and reducing errors in the application of stamps, thus improving the optical performance and user experience of spectacle lenses.
Implementation Method 1
a retroreflector (37), with which the light beam can be reflected back into itself
Implementation Method 2
a suction holder (36), on which the spectacle lens (35) can be held
Data Source
Figure 1A
Figure 1B
Figure 1C
AI summary
Methods and devices for determining the position and/or orientation of a spectacle lens (35) bearing permanent markings on a holder (36), in particular a suction holder, are provided. For this purpose, for example, the apparent position of permanent markings on the spectacle lens is detected by means of a detection device (31, 33). In addition, the spectacle lens (35) is illuminated eccentrically to an optical axis (310) of the detection device by means of further light sources (34A to 34C). The resulting reflections are also detected. Based on the detected reflections and the apparent position of the permanent markings, the position and/or orientation is determined.