Abstract
In this study, we proposed a method for surface profiling aspheric lens molds using a precisiondisplacement sensor with a spatial scanning mechanism. The precision displacement sensor is based on theconfocal principle using a broadband light source, providing a 10 nm resolution over a 0.3 mm measurablerange. The precision of the sensor, depending on surface slope, was evaluated via Allan deviation analysis.
We then developed an automatic surface profiling system by measuring the cross-sectional profile of a lensmold. The precision of the sensor at the flat surface was 10 nm at 10 ms averaging time, while 200 msaveraging time was needed for identical precision at the steepest slope at 25 deg. When we compared themeasurement result of the lens mold to a commercial surface profiler, we found that the accuracy of thedeveloped system was less than 90 nm (in terms of 3 sigmas of error) between the two results.
We then developed an automatic surface profiling system by measuring the cross-sectional profile of a lensmold. The precision of the sensor at the flat surface was 10 nm at 10 ms averaging time, while 200 msaveraging time was needed for identical precision at the steepest slope at 25 deg. When we compared themeasurement result of the lens mold to a commercial surface profiler, we found that the accuracy of thedeveloped system was less than 90 nm (in terms of 3 sigmas of error) between the two results.
| Translated title of the contribution | Precision Surface Profiling of Lens Molds using a Non-contact Displacement Sensor |
|---|---|
| Original language | Korean |
| Pages (from-to) | 69-74 |
| Number of pages | 6 |
| Journal | 한국기계가공학회지 |
| Volume | 19 |
| Issue number | 2 |
| DOIs | |
| State | Published - 2020 |