摘要 |
<p>An omnidirectional scanning apparatus which generates a multiple cross scanning pattern is described. The scanning apparatus comprises a flat ring-shaped hologram. The hologram disk is rotated about its axis as a small area is illuminated by a collimated light source, such as a laser, to produce a series of reconstructed beams which scan segments of a circle. Optical means is provided to intercept the reconstructed beams and reflect them to a scanning window where the segments produce a multiple cross scanning pattern. In a specific embodiment the holograms recorded are reconstructed as segments of concentric circles and the optical means comprises a stationary mirror for each direction of scan across the scanning window.</p> |