| 摘要 |
<p>1,245,783. Uses of photochromism. RCA CORPORATION. 5 Dec., 1968 [7 Dec., 1967], No. 57756/68. Heading C4S. A display device comprises a photochromic screen 16, means 15 for selectively concentrating or focusing light at discrete regions within the screen volume to produce in these regions a power intensity to change the light absorbtion characteristic of the regions and means for directing on to the screen light of an intensity which produces no change to provide a three dimensional display. A light beam 12 from a laser 11 is passed through a light intensity modulator 13 and light deflector 14 which produces a two dimensional raster. The beam is then focused by a lens 15 on a transparent p.c. target 16 to provide a 10 micron diameter sphere of light of an intensity which turns the target opaque by double photon absorbtion. The target is moved to form the 3 dimensional pattern which may comprise a series of two dimensional patterns. Data is read by scanning the target with an unfocused beam or flooding the target with light from the laser 11 or another source. The pattern is erased by flooding or scanning the target. The p.c. material may be organic, CaF 2 La or SrTiO 3 : Fe, Mo, the source 11 includes ruby, A, Kr, Xe or Nd doped YAG lasers. The beam may be deflected by mechanical, electromechanical, electroacoustic or electro-optical means. Alternatively the laser or target may be moved.</p> |
