Optical position sensor with corner-cube and servo-feedback for scanning microscopes
US5196713A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | May 13, 1992 |
| Grant date | Mar 23, 1993 |
| Priority date | — |
| Expiry date | May 13, 2012 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S977/872
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A scanning probe microscope includes a probe support carrying a scanning probe, a piezoelectric transducer having a free end connected to a stage on which the sample is supported, probe sensing circuitry connected to sense a signal indicating interaction between the tip of the probe and a point of the sample surface and producing in response thereto a Z control voltage so as to optimize the interaction and produce a Z coordinate representing the height of a presently scanned point of the sample surface. Optical sensing circuitry includes a light source connected in fixed relation to the sample stage, a position sensitive photodetector, and optics focusing lens for focusing a portion of the light onto a position sensitive detector to cause it to produce X and Y position signals. The light source includes a retroreflector attached to the piezoelectric transducer receiving a beam from a stationary laser and focused by a stationary lens onto the position sensitive detector. Feedback servo circuits are responsive to the X and Y position signals to apply X and Y control voltages to the piezoelectric transducer.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.