A rear projection screen of the present invention includes lens sheets or optical sheets having an optical function of condensing or diffusing light. The lens sheets or optical sheets have, as a whole, two or more diffusing layers (diffusing parts) separately provided in the light-transmitting direction. It is preferable that one of the two or more diffusing layers be provided on the light-entering-side surface of the outermost lens sheet or optical sheet on the light source side and that another one of the diffusing layers be provided on the light-emerging-side surface of the outermost lens sheet or optical sheet on the observation side. Any two of the two or more diffusing layers are such that the light-source-side diffusing layer has a diffusing power lower than that of the observation-side diffusing layer. Further, it is preferable that the types (refractive indexes or average particle diameters) of diffusers to be respectively incorporated into any two of the two or more diffusing layers be different from each other.

 
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> Optical recording/reproducing apparatus for optical disks with various disk substrate thicknesses

~ 00424