| 摘要 |
PURPOSE:To reduce the size and cost of a recording and reproducing device by projecting the laser light corresponding to a signal to a thin film essentially consisting of opaque low oxide of nickel thereby recording information. CONSTITUTION:The laser light corresponding to the signal is projected to the thin film essentially consisting of the opaque low oxide of nickel to form the image. The low oxide of nickel refers to a material expressed by NixOy (0<y/x<1) and is an n-type semiconductor which is usually dark brown. The transmittance of visible light of the low oxide film of nickel is larger as the value y/x approaches 1. The film having a large degree of black color in the region where x/y is relatively approximate 0 is oxidized by the heat energy of the laser light corresponding to the signal to the state in which y/x is 1 or nearly 1, by which said film is made transparent. Writing of the signal by the laser light is executed by converting the thin opaque low oxide film of nickel to transparent nickel oxide by thermal oxidation. For example, a semiconductor laser 1 of GaAlAs, etc., having 780nm is used. The reading is executed by projecting lower output light using the same laser. |
