| abstract |
A duplicating photosensitive material film is placed into close contact with a thin flexible ND glass or an ND glass coated with a cushioning layer through an optical contacting liquid containing a surface active agent. A spacer is interposed between a hologram original plate and the duplication photosensitive material, and the space defined by the spacer is filled with an optical contacting liquid, the spacer thereby regulating the thickness of the optical contacting liquid layer. In addition, a cushioning layer is provided on the inner side of an AR coated ND glass or on the upper side of the photosensitive material film, and another cushioning layer is provided on the side of an original plate protecting glass of the hologram original plate which is closer to the optical contacting liquid or on the lower side of the photosensitive material film. With this arrangement, even if dust enters, it can be effectively held inside the cushioning layers. Thus, it is possible to prevent undesirable flow of the optical contacting liquid and lifting of the film due to dust and hence possible to perform duplication effectively without any hindrance. |