| 摘要 |
An apparatus for "fast erase" of thermochromic information displays is provided. A piezoelectric substrate (10) has a thin film (18) of vanadium dioxide deposited on the surface thereof. The film undergoes marked increases in reflectance at any region thereof experiencing thermal heating in excess of its predetermined transition temperature. An ultrasonic surface acoustic wave transducer (11) is provided which includes a pair of electrodes (12, 14) spaced apart in substantially parallel relation on the surface of the substrate (10) such that application of an RF signal across the electrodes (12, 14) causes deformation of the substrate to generate surface acoustic waves on the surface thereof and in the film to counteract built-in strains in the film to erase images written into the film. A solid state information display using pressure sensitive material is also disclosed. A thin film of samarium sulphide (30) is deposited on the surface of a piezoelectric substrate (10) such as lithium niobate. The film undergoes marked increases in reflectance at any region thereof subjected to a pressure in excess of a predetermined threshold pressure. Three surface acoustic wave transducers (34, 36, 38) are provided on the substrate (10) positioned relative to the film such that eastwardly, westwardly and northwardly traveling surface waves are produced in the film. A video signal generator (40) is provided for each of the transducers with delay units (42) for launching pulses at preselected times in the film such that a point of pressure in excess of the threshold pressure can be selectively created to increase the reflectance of the film at that point.
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