| 摘要 |
PROBLEM TO BE SOLVED: To manufacture a light guide plate provided with an area having a relatively high scattering power and an area having a relatively low scattering power in a simple process by using the sandwich molding method and manufacturing the light guide plate of light scattering light guide type. SOLUTION: The injection of a material B for a skin layer only is carried out to fill the whole of a cavity. The injection of the material B is carried out in the final stage, by which the necessary process is started in the state of leaving the material B for the skin layer only on a nozzle end section of a molding machine. The formation of an unnecessary high scattering power area, therefore, is avoided in the initial stage of the following process by the arrangement. Unlike the two-color molding, the insert molding or the like, a material A for a core layer and the material B for the skin layer are injected. As the flows of both materials in the molten state are brought into contact with each other for a certain period of time, the material A is mixed with the material B on a boundary section. Thus neither the boundary of a core layer and the skin layer gets excessively definite and sharp nor a discontinuous layer of refractive index is formed. |
