Information reproducing apparatus with plural beam readout
US4085423A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 28, 1976 |
| Grant date | Apr 18, 1978 |
| Priority date | — |
| Expiry date | May 28, 1996 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B7/12
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
Information reproducing apparatus for producing information on an optical information recording medium includes a first light source which gives forth a beam of light of a wavelength .lambda..sub.1 and a second light source which gives forth a beam of light of a wavelength .lambda..sub.2 different from the wavelength .lambda..sub.1. An optical element selectively reflects the light of the wavelength .lambda..sub.1 and selectively transmits the light of the wavelength .lambda..sub.2. The first and second light sources, the optical element and the recording medium are positionally arranged so that the light beams from the first and second light sources may be projected on a predetermined position of the recording medium and a substantially identical position to the predetermined position through the optical element, respectively, and the arrangement of these elements is also such that the respective projected light beams may fall on the optical element after being reflected by the recording medium. First and second photodetectors detect light reflected from the optical element and light transmitted light through the same in accordance with the wavelength of the light beams falling on…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.