Patent ID: 9176365
Filing Date: 2015-11-03
Classification: F21V,G02B,G03B,G03H

Abstract:
1. An illumination device comprising: an optical element including a hologram recording medium including a first zone and a second zone; an irradiation device configured to irradiate the optical element with a coherent light beam such that the coherent light beam is allowed to scan the first zone and the second zone of the hologram recording medium, and such that the coherent light beams incident on respective positions in the first zone of the hologram recording medium are diffracted by the hologram recording medium to illuminate zones which overlap each other in at least a portion thereof with the coherent light beams, and the coherent light beams incident on respective positions in the second zone of the hologram recording medium are diffracted by the hologram recording medium to illuminate zones which overlap each other in at least the portion with the coherent light beams; and a polarization control unit provided on an optical path of the coherent light beams, the polarization control unit being configured to control polarization of the coherent light beams such that a coherent light beam incident on the first zone of the hologram recording medium to travel toward a designated illumination zone has a first polarization component and such that a coherent light beam incident on the second zone of the hologram recording medium to travel toward a designated illumination zone has a second polarization component different from the first polarization component.