Patent ID: 6924912

Claim:
A holographic screen for displaying images by diffracting and dispersing an image beam projecting by an image projector, comprising: a main hologram for diffracting and dispersing an incident image beam from one of an upward angle and a downward angle; and a directional dispersion hologram, disposed on an image projector side of the main hologram, for dispersing and transmitting part of the image beam within a predetermined angle range centered on a direction of incidence thereof, and directly transmitting another part of the image beam; wherein the directional dispersion hologram, after a photosensitive material and a diffuser have been superposed, is produced by radiating a reference beam from the diffuser side at a predetermined angle to a normal thereof, transmitting and diffusing it through the diffuser to make a diffused beam, and exposing the photosensitive material to the diffused beam.