Apparatus for determining the position of a surface
US3994589A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 30, 1975 |
| Grant date | Nov 30, 1976 |
| Priority date | — |
| Expiry date | Apr 30, 1995 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01B11/026
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
This invention is directed to an electro-optical apparatus for determining the position of an opaque surface without contact with the surface. It includes a light beam system which projects a well defined beam having a rectangular cross-section, obliquely onto the surface such that any movement of the surface in the perpendicular direction will result in a displacement of the illuminated area on the surface, and a detector which converts this displacement into a proportional light intensity. The detector has a field stop with an aperture of specific shape onto which the illuminated area is imaged such that only a portion of the image will pass through the aperture depending on the displacement of the illuminated area. A photosensitive device is used to measure the light intensity passing through the aperture. Embodiments of apparatus for normalizing the output for greater precision are described as well as a system for measuring the thickness of an object by determining the position of two opposite surfaces of the object.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.