Horizontal position detecting device
US4558949A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 17, 1982 |
| Grant date | Dec 17, 1985 |
| Priority date | — |
| Expiry date | Sep 17, 2002 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03F9/7034
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
Disclosed is a horizontal position detecting device for maintaining the surface of a body to be inspected vertically to the optical axis of a main objective lens. The device includes an illumination optical system and a condenser lens system. The illumination optical system supplies parallel light rays to the surface of the body from the direction oblique to the optical axis of the objective lens. The condenser lens system condenses the light rays supplied by the illumination optical system and reflected by the surface of the body. The optical axes of the illumination optical system and the condenser lens system are arranged substantially symmetrically with respect to the axis of the objective lens.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.