Method for inspecting transparent polymer substrate used in forming transparent area in banknote, involves determining polymer substrate to be defective if transmittance of UV light through region of polymer substrate exceeds preset value

摘要

The method involves irradiating the UV light from a light source (10) to a transparent polymer substrate (100). A sensor (20) is provided for receiving the light transmitted through the polymer substrate. The degree of transmittance of the UV light in the defined region of the polymer substrate is determined and the polymer substrate is determined to be defective if the transmittance of UV light through defined region of polymer substrate exceeds predetermined value. An independent claim is included for device for inspecting transparent polymer substrate.