Eyeglass Lens Processing Apparatus with Tilting Tracing Stylus

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Solution Overview

Problem

Existing eyeglass lens processing apparatuses face challenges with complex configurations and increased costs due to large size of lens shape measuring mechanisms, which can lead to dust infiltration and reduced measurement accuracy, and wobbling of processing tools during chamfering and grooving, affecting processing accuracy.

Innovation Solution

A simplified eyeglass lens processing apparatus with a tracing stylus that tilts in multiple directions to maintain contact with the lens refractive surface, using a combination of rotating and tilting mechanisms to reduce the size of the measuring unit and prevent tool wobbling, while maintaining accurate shape measurement and processing.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If the tracing stylus is configured to move in the axial direction of the lens chuck shaft with a large movable range to follow the refractive surface shape, then the measurement capability is improved, but the size of the lens shape measuring mechanism is increased and cost increases

Engineering Contradiction:
Improvemeasurement capabilityVSAvoidsize of measuring mechanism
Core Design Contradiction:
Measurement precisionVSVolume of moving object

Solution Approach 1:

The tracing stylus is configured to tilt in the radial direction of the lens chuck shaft instead of moving in the axial direction. This dimensional change from axial movement to radial tilting allows the stylus to follow the refractive surface shape while maintaining a compact mechanism size, resolving the contradiction between measurement capability and mechanism size.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Measurement precision

If the tracing stylus is configured to move in the axial direction with a large movable range, then the refractive surface shape can be followed, but the configuration becomes complex due to required driving mechanisms

Engineering Contradiction:
Improvemeasurement capabilityVSAvoidconfiguration complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The stylus tilting mechanism in the radial direction replaces the complex axial movement mechanism. By changing the dimension of movement from axial to radial tilting, the patent simplifies the overall configuration while maintaining the ability to track the refractive surface shape accurately.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

3Measurement precision

If a linear motion mechanism with guide rail and rack is used for axial movement of the tracing stylus, then the measurement function is achieved, but dust infiltration into the mechanism occurs causing problems in smooth movement

Engineering Contradiction:
Improvemeasurement functionVSAvoiddust infiltration
Core Design Contradiction:
Measurement precisionVSObject-affected harmful factors

Solution Approach 1:

The patent replaces the linear motion mechanism (guide rail and rack) with a tilting mechanism in the radial direction. This dimensional change eliminates the need for extensive linear motion components that are prone to dust infiltration, thereby ensuring smooth and reliable stylus movement.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

4Productivity

If the processing tool is moved by the processing tool retracting mechanism between processing position and retracting position, then the processing function is achieved, but wobbling of the processing tool occurs degrading processing accuracy

Engineering Contradiction:
Improveprocessing functionVSAvoidprocessing accuracy
Core Design Contradiction:
ProductivityVSManufacturing precision

Solution Approach 1:

Instead of moving the processing tool axially between processing and retracting positions, the patent inverts the approach by maintaining the tool in a fixed position and moving the lens workpiece. This eliminates the wobbling associated with tool retraction mechanisms while preserving the processing function.

Inventive Principle:
Principle #13The other way round (Inversion)

Solution Approach 2:

The patent employs dynamic movement of the lens workpiece on the chuck shaft to bring different portions of the lens into the processing position, rather than dynamically retracting the processing tool. This dynamic approach to workpiece positioning eliminates tool wobbling while maintaining processing capability.

Inventive Principle:
Principle #15Dynamics

Data Source

PatentEP2636485B1Eyeglass lens processing apparatus
Publication Date: 2017.09.20 NIDEK CO LTD
  • EP2636485B1 patent drawingFigure 1
  • EP2636485B1 patent drawingFigure 2
  • EP2636485B1 patent drawingFigure 3

AI summary

An eyeglass lens processing apparatus includes: lens rotating means for rotating a lens chuck shaft; chuck shaft moving means for moving the lens chuck shaft; a processing tool that processes a lens; axis-to-axis distance changing means for changing a distance between the lens chuck shaft and the processing tool; lens shape measuring means including a tracing stylus holding unit that holds a tracing stylus contacting the lens to be movable in the axial direction of the lens chuck shaft and detecting means for detecting a movement position in a direction of the lens chuck shaft of the tracing stylus; lens moving means for relatively moving the lens in a direction in which a distance between the lens chuck shaft and the tracing stylus is changed; and controlling means for controlling the lens rotating means and the lens moving means based on a target lens shape, and controlling the chuck shaft moving means so that the movement position in the direction of the lens chuck shaft of the tracing stylus is in a predetermined range during measurement of a shape of the lens.