| 摘要 |
1349731 Digital data stores ENERGY CONVERSION DEVICES Inc 30 April 1971 [8 June 1970] 12472/71 Heading G4C [Also in Division C7] A store comprises an amorphous film in which bubbles are formed by a modulated beam of electromagnetic energy. The stored data is erasable by heating the film to cause the bubbles to collapse. The beam may be a laser beam, for example. In one embodiment, Fig. 1 (not shown), the beam is directed to successive areas of the film to record each bit. The beam is pulsed, the width and power of each pulse being selected according to the action, Write, Erase, or Read, required. In the Write and Erase modes the laser frequency is such that the beam is substantially absorbed in the film. In the Write mode the power is sufficient to cause local internal vaporization of the film to represent a bit of one state, the resulting bubbles being frozen in as the beam leaves their locality. In the Read mode the laser frequency is such that the beam is not absorbed by the film. A detector senses the radiation passing through the film, the detector output decreasing when the beam passes through an area of bubbles. In the Erase mode the beam energy is sufficient to soften the film but insufficient to cause bubble formation. The store may be Read simultaneously with Writein. The bit read out may be compared with the bit just read in to check for error. In a second embodiment, Fig. 6 (not shown), the detector senses radiation reflected from the film. In a third embodiment, Fig. 6 (not shown), a broad beam of radiation passes through a negative, carrying information to be recorded, and on to the film. In this case the store is erased by an associated heating element. It is stated that analog data may be stored instead of digital data. |
