Patent ID: 7129007

Claim:
A hologram producing apparatus comprising: a supply unit for a recording medium for hologram, and an exposure unit for irradiating object light and reference light onto a recording medium for hologram supplied from the supply unit to record hologram, wherein the recording medium for hologram comprises a hologram recording layer on which hologram is recorded, and a base and a protective layer between which the hologram recording layer is put, and the recording medium for hologram is formed in rectangular shape, the base and the protective layer comprise material through which light is transmitted and in which an axial direction of that double refraction is perpendicular or nearly perpendicular to the longer side of the rectangular shape and the thickness of the protective layer, the object light and the reference light that the exposure unit irradiates are linearly polarized light polarized in a direction equal or nearly equal to the axial direction of double refraction or in a direction perpendicular or nearly perpendicular to the axial direction of double refraction.