| 摘要 |
PROBLEM TO BE SOLVED: To provide a hologram substrate in which irradiating laser light can be efficiently used for projecting a reproduced image, to provide a method for manufacturing a hologram substrate by which the hologram substrate can be manufactured with high efficiency, and to provide an image projector. SOLUTION: The hologram substrate 1 is composed of a first layer 11 disposed in the incident side of a laser beam and a second layer 12 disposed in the exit side of the laser beam, wherein the substrate has a hologram pattern 111 on the face of the first layer 11 where the laser beam exits and a large number of minute concaves and convexes 112, 121 on the face of the first layer 11 where the laser beam enters and on the face of the second layer 12 where the laser beam exits. The average pitch of adjoining convexes, the width of the concaves and convexes, and the height difference of the concaves and convexes in the concaves and convexes 112, 121 are 30 to 50% of the wavelength of the laser beam. The average absolute difference between the refractive index of the first layer 11 and the refractive index of the second layer 12 is 0.05 to 0.5. COPYRIGHT: (C)2008,JPO&INPIT
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