Patent ID: 9454014
Filing Date: 2016-09-27
CPC Classification: G02B,G02F,G03B,G03H,H04N

Claim Text:
1. An illumination device comprising: an optical device including a hologram recording medium capable of reproducing an image of a reference member on an illumination zone, the optical device varying an incidence angle of the coherent light beam at each position on the illumination zone with time; and an irradiation unit configured to irradiate a coherent light beam to the optical device so that the coherent light beam scans the hologram recording medium, wherein the irradiation unit comprises: a light source configured to emit a coherent light beam, the light source comprising a plurality of light sources configured to emit a plurality of coherent light beams having an identical wavelength range; and a scanning device comprising a reflection device which reflects the plurality of coherent light beams emitted from the plurality of light sources while changing a reflection direction of each of the plurality of coherent light beams within a predetermined range to scan a recording area of the hologram recording medium, wherein the hologram recording medium comprises the recording area to be scanned with each of a plurality of coherent light beams reflected by the scanning device, and the recording area comprises an interference fringe that diffracts an incident coherent light beam, each of the plurality of coherent light beams scans a corresponding partial area in the recording area, and the plurality of coherent light beams diffracted by the interference fringe of each partial area in the recording area is superimposed on at least one portion of the illumination zone to reproduce the image of the reference member.