Laser marking on photosensitive material and photosensitive material including the marking

摘要

By irradiating a laser beam onto an X-ray film that includes a support layer having disposed thereon an emulsion layer, the emulsion layer is melted, numerous minute air bubbles are generated in the emulsion layer, and the emulsion layer becomes convex, whereby a visible dot pattern is formed. The irradiation time and wavelength of the laser beam are selected so that separation is not generated between the support layer and the emulsion layer. By defocusing and irradiating the laser beam, the X-ray film may substantially uniformly receives energy of the laser beam. Moreover, an undersurface layer may also be formed, and the laser beam may be irradiated onto the undersurface layer to form a dot pattern on the undersurface layer. A device and a method for forming a marking pattern representing identification information on a rolled photosensitive material and cutting the photosensitive material into sheets are disclosed.