Methods and apparatus for truncating an image formed with coherent radiation
US7253376B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jan 21, 2005 |
| Grant date | Aug 7, 2007 |
| Priority date | — |
| Expiry date | Jun 11, 2025 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB23K2101/40
- WIPO fieldMachine tools
- WIPO sectorMechanical engineering
Abstract
Methods and apparatus for truncating an image formed with coherent radiation. The optical relay system is adapted to form a line image at the image plane. The image is truncated by a variable aperture at or near the aperture plane conjugate to the image plane, to block progressively increasing portions of an incident coherent radiation beam used to form the line image. An apodizing pupil filter having a maximum transmission or reflection in the center and a transmission or reflection profile that varies with direction corresponding to long direction of the line image is provided in the pupil plane. The apodization is designed to prevent hot-spots from forming in the truncated image and ensures a relatively smooth, flat intensity profile. Thus, one end or another of a coherent line image scanned over a substrate can be truncated during scanning without substantially changing the image intensity extending into the product area.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.