Image reader using two frames each driven by a different motor for adjustment of focus
US5221974A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 18, 1990 |
| Grant date | Jun 22, 1993 |
| Priority date | — |
| Expiry date | Sep 18, 2010 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N2201/0434
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
An image reading device including a contact glass on which an original sheet is set, an exposure lamp for irradiating a face of the original sheet on the contact glass to scan it, a photosensitive element provided below the contact glass, a first mirror for reflecting the light reflected by the original sheet in parallel with an original scanning direction, a second mirror for reflecting the light from the first mirror, a third mirror for reflecting the light from the second mirror, a lens for imaging the light from the third mirror on the photosensitive element, a first moving frame mounting the exposure lamp and first mirror and movable in the original scanning direction, a second moving frame mounting the second and third mirrors and movable following the first moving frame, first and second motors for shifting the first and second moving frames, respectively, and a controller for controlling a driving velocity of the second motor to keep the optical length from the face of the original sheet to be exposed to the light to the lens unchanged.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.