Automatic focusing apparatus in optical drawing machine
US4512642A · kind A · utility
10Cited by
6References
3Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Sep 15, 1982 |
| Grant date | Apr 23, 1985 |
| Priority date | — |
| Expiry date | Sep 15, 2002 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03F7/704
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
Automatic focusing apparatus in an optical drawing machine, comprising a drawing optical means having a dichroic mirror which transmits light for drawing and reflects light for detecting the focus to apply the focus detecting light to which a photosensitive material is insensitive onto the latter, an imaging lens means, and a focus detecting device for detecting whether the surfaces of the photosensitive material are located in the depth of focus of the drawing optical means.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.