Camera filters and a method of making the same
US4311364A · kind A · utility
6Cited by
1References
10Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Apr 29, 1980 |
| Grant date | Jan 19, 1982 |
| Priority date | — |
| Expiry date | Apr 29, 2000 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03B11/00
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A filter for a camera comprises a filter plate, and a split frame formed from a thermoplastic synthetic resin and holding the filter plate therein. The frame is composed of an internally threaded front portion and an externally threaded rear portion adapted for attachment to the lens holding tube of the camera. The front and rear portions are integrally secured to each other by thermal fusion, with an adhesive, by threaded connection, and combinations thereof. Also disclosed is a method of making such a filter. The thermal fusion of the frame portions is advantageously effected by application of ultrasonic waves.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.