Optical recording element having a plurality of thin film filtering layers and optical recording element having an electrically conductive layer
US5214636A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 16, 1989 |
| Grant date | May 25, 1993 |
| Priority date | — |
| Expiry date | Oct 16, 2009 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B7/254
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
An optical recording element according to the present invention comprising: (i) a transparent substrate through which light passes; (ii) a transparent low-resistance layer having a specific resistance so as to prevent the adhesion of dust to the surface of the element caused by a static charge, the layer being formed on the surface, on which a light beam is incident, of the transparent substrate; and (iii) an optical thin film composed of at least one layer, formed on the other surface of the transparent substrate so as to transmit light beams used for recording, erasing and playback, and reflect lights which have wavelengths different from the wavelength of the above light beams and are within a specified visible region of the spectrum. With this arrangement, lights within a specified visible region of the spectrum are reflected so that the element appears to be colored according to the wavelengths of the reflected lights. Also, a problem often found in a conventional optical recording element having a transparent substrate of a resin material that the surface of the element is hardened by a light beam, can be solved. Even if a static charge is generated on the surface of such an …
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.