Rotary beam chopper with continuously variable duty cycle
US4499362A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jun 29, 1983 |
| Grant date | Feb 12, 1985 |
| Priority date | — |
| Expiry date | Jun 29, 2003 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB23K26/0676
- WIPO fieldMachine tools
- WIPO sectorMechanical engineering
Abstract
Apparatus for converting a continuous incident laser beam into a pulsed laser beam, with a duty cycle of pulsation that is substantially continuously variable between a minimum value and a maximium value, is disclosed. The apparatus uses a rotatable disc of nontransmissive material which has a plurality of apertures and adjacent nontransmissive portions disposed in an annular zone. The ratio of the width of each aperture to the width of the adjacent nontransmissive portion substantially continuously varies radially from a minimum ratio to a maximum ratio. As the disc is rotated, the beam is alternately transmitted and blocked, so that a pulsed output beam emerges. The duty cycle of the beam can be adjusted by radially varying the point of incidence of the incident beam within the annular zone so that it impinges on the zone at a radius at which the ratio of widths is at a desired value. Such apparatus can be used in a system for perforating a web of sheet material with a pulsed laser beam.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.