Spatial filtering of laser ghosts
US6853652B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jun 27, 2001 |
| Grant date | Feb 8, 2005 |
| Priority date | — |
| Expiry date | Jul 21, 2022 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B5/584
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
An optical servo writer system including a laser subsystem to generate a multiplicity of light beams, a lens positioned to receive and focus the light beams and a spatial filter positioned in the system so as to allow a subset of the light beams to pass through the filter. The multiplicity of light beams includes the subset that contains the desired beams, or the servo beams, and also the undesired beams, called the ghost beams. The system further includes a digital linear tape positioned adjacent the spatial filter with the spatial filter allowing the subset of light beams to hit the digital linear tape and produce servo marks. The spatial filter includes openings positioned to allow the subset of light beams to pass through the filter. The openings may be staggered relative to the digital linear tape to prevent debris generated by the marking process from clogging the openings.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.