| 摘要 |
PURPOSE: To provide a wavelength shift type large-aperture, short-focus hologram condenser lens with excellent characteristics. CONSTITUTION: The hologram condenser lens consists of plural mini-holograms 11-16 and a hologram is formed out of parallel reference lights 311-316 and diverged body lights 321-326. The incidence angleθr of the reference lights 311-316 or the incidence angleθo of the body lights 321-326 is varied by areas 21-26 of a hologram dry plate 2 corresponding to the mini-holograms 11-16 so that diffracted lights corresponding to the same irradiation lights travel to the same focuses. The sizes of the mini-holograms 11-16 are determined so that the divergence angleΔθo of the body lights 321-326 becomes smaller.
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