Image reading device, image reading method, and light source for the same
US6919974B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Nov 22, 1999 |
| Grant date | Jul 19, 2005 |
| Priority date | — |
| Expiry date | Nov 22, 2019 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N1/193
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
The image reading device of the present invention reads images by using a visible light and an invisible light that are generated by a single light source. The fluorescent lamp is provided with a pair of internal electrodes and a pair of external electrodes. It generates a visible light with a higher intensity than an infrared light when switching a feeder circuit on to generate a discharge between the external electrodes. On the other hand, it generates an infrared light with a higher intensity than a visible light when switching another feeder circuit on to generate a discharge between the internal electrodes. Therefore, the fluorescent lamp has a reading mode using the visible light, and a reading mode using the infrared light. And, a lamp controller selectively switches the emission mode of the fluorescent lamp.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.