Surface flatness measuring apparatus
US6275032A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 21, 1998 |
| Grant date | Aug 14, 2001 |
| Priority date | — |
| Expiry date | Dec 21, 2018 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B33/10
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A flatness measuring apparatus is adapted to measure the flatness of the surface of a plate-shaped object such as a disk in a non-contact fashion. A disk is removably held by a measuring table, with the projection of the measuring table engagedly received in a central through hole of the disk. A plurality of eddy current undulation sensors are arranged in a sensor head that is arranged so as to be able to linearly move back and forth along the measuring table. Said eddy current undulation sensors generate an eddy current in said disk and detect any undulation on the surface of said disk. A flatness map is produced for the surface of the disk based on a signal representing the position of the sensor head and on signals from the eddy current undulation sensors, and then is output to a display and/or a printer.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.