| 摘要 |
PURPOSE:To eliminate the need for an adhesive agent and the influence on a recording material and to simplify the stage so as to reduce the cost of the medium by engaging a substrate and a back material via a spacer, then applying heat to an annular heat shrinkable material provided to the outer peripheral part to shrink and fix the material. CONSTITUTION:After a recording layer 2 is provided on the transparent substrate 1, the back material 3 is engaged therewith via the spacer 4. The annular heat shrinkable material 5 is provided on the outer peripheral part of the base material 1 and the back material 3 and the heat is applied thereto to shrink the material. A resin essentially consisting of polytetrafluoroethylene is used for the shrinkable material 5. The substrate 1 and the back material 3 are joined by the shrinkage provided with the inside diameter larger than the diameter of the substrate 1. The spacer 4 and the back material 3 are pushed uniformly in the central direction and the outer peripheries are made flush with each other at the time of the shrinkage and, therefore, the need for positioning is eliminated and the need for pressing in the thickness direction is eliminated as well. The need for the adhesive agent is eliminated in this way and the erosion is prevented, by which the stage is simplified and the cost is reduced. |
