Patent ID: 6952295

Claim:
A hologram screen for displaying an image by diffracting and scattering image light projected from an image projection apparatus, comprising: an upward/downward light scattering device placed on an image projection apparatus side of a hologram device in the hologram screen, and oriented so as to scatter light incident from at least one upward/downward specific angle range spreading obliquely upward or obliquely downward; and a leftward/rightward light scattering device placed between the hologram device and the upward/downward light scattering device or on the image projection apparatus side of the upward/downward light scattering device, and oriented so as to scatter light incident from a leftward/rightward specific angle range spreading obliquely leftward and obliquely rightward, wherein the upward/downward specific angle range contains an incidence angle at which the image light is incident on the hologram screen; and wherein when the leftward/rightward specific angle range is from γ 1 to γ 2 leftward and from δ 1 to δ 2 rightward relative to a normal to the hologram screen, γ 1 , γ 2 , δ 1 , and δ 2 satisfy 20°≦γ 1 ≦25°, 65°≦γ 2 ≦70° 20°≦δ 1 ≦25°, 65°≦δ 2 ≦70°.