Servo tracking system utilizing phase-sensitive detection of reflectance variations
US5767941A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Apr 23, 1996 |
| Grant date | Jun 16, 1998 |
| Priority date | — |
| Expiry date | Apr 23, 2016 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01S17/86
- WIPO fieldMedical technology
- WIPO sectorInstruments
Abstract
Apparatus and methods for tracking a feature on a target surface and continually providing analog corrections to tracking mirrors in real time by utilizing a low-power incoherent tracking beam to detect the movements of a reference feature on the target and confocal reflectometry to monitor the reflection from the tracking beam's current position are described. The apparatus includes a dithering device for dithering the tracking beam in a first and a second direction with an oscillatory motion, a tracking device for controlling the position of a therapeutic beam relative to a target and for controlling the position of the tracking beam relative to a reference feature, a reflectometer for providing an output signal with a phase corresponding to a phase of the reflected tracking beam, and a signal processor for comparing the phase of the reflectometer output signal to the phases of the oscillatory motion and for controlling the tracking device so that the therapeutic beam to tracks relative to the reference feature.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.