Dual format dual resolution scanner with off-axis beams
US5861977A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Feb 26, 1997 |
| Grant date | Jan 19, 1999 |
| Priority date | — |
| Expiry date | Feb 26, 2017 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N1/1135
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A laser scanner (10) has a light source (12), which produces a light beam (32) which is incident on a polygon tower (14) comprised of a first polygon (30) having a first diameter and first number of facets, and a second polygon (20) having a second diameter and second number of facets. The polygon tower (14) rotates about an axis common to both the first (30) and second (20) polygon and the first polygon. The point at which the light beam is incident on the polygon tower is shifted in a direction approximately parallel to the axis of the polygon tower so that the incident light is directed at either the first polygon or the second polygon. In one embodiment a reflected light beam from one of the polygons is off center from an optical axis of a scan lens (16). Moving the point at which the light beam is incident on the polygon tower (14) from the first polygon (30) to the second polygon (20), changes the format size, and resolution without moving or refocusing the scan lens, and without moving the polygon tower (14) or the imaging medium.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.