1. Field of the Invention
The present invention relates to a device for separating a coating film from the surface of a substrate held in close contact therewith and to a method of separating such a coating film by using the device.
2. Description of the Related Art
The surface of a resin substrate of acrylic resin, polycarbonate or the like and that of a glass substrate are subject to flaws and adhesion of dust. In view of this, coating films are loosely adhered to these surfaces by means of an adhesive or the like. In particular, in the case of a substrate for an optical recording medium, such as an optical card or an optical disc, any flaws on the surface of the substrate and adhesion of dust thereto will lead to defects in the optical recording medium to be obtained therefrom. Accordingly, where the fabrication of such substrates and the process of making optical recording mediums from then are not conducted continuously, the above-mentioned adhesion of coating films to the substrate surfaces is an effective means for improving the yield of the optical recording mediums.
However, in the above method of separating coating films, a double-coated adhesive tape is employed to separate the coating films from the substrate surfaces. Thus, as the operation of separating coating films is continued, the adhesive strength of the double-coated adhesive tape gradually degenerates, with the result that it becomes difficult to raise the coating film from the substrate surface in a stable manner. To raise the coating films in a stable manner, it is necessary to periodically replace the double-coated adhesive tape with a new one, resulting in the need to use a large number of such adhesive tapes.
Further, as the conventional separating operation described above is performed manually, the efficiency of such an operation is rather poor. Moreover, with this conventional method, the substrate from which the coating film has been removed is subject to flaws and adhesion of dust.
Another problem with the manual separation is that the speed at which the coating film is separated differs from substrate to substrate. Such a difference in the separation speed may cause the substrates to be electrically charged, with the charging amount varying greatly from substrate to substrate. Further, some of the adhesive of the coating film may remain at various portions on the substrate surface. Thus, with the conventional, manual separation method, it is difficult to keep the condition of the surfaces of the substrates uniform after the separation of the coating films therefrom.