OPTICAL COORDINATE INPUT DEVICE

摘要

PURPOSE:To prevent the crosstalk between optical guiding paths by inserting a light emitting matter having a small common wavelength between the wavelengths of a light emitting area and a light absorbing area. CONSTITUTION:A light guiding path 2 is formed by providing the clad layers on both sides of a core layre, and optical guiding paths 2a and 2b containing photodetecting means 8a and 8b are set in parallel to both ends of the path 2. Thus an optical guiding path type coordinate input device. Here fluorescent matters 14a and 14b are used in place of the conventional diffusing matters as the light emitting matters having small wavelength common to the wavelengths of both a light emitting area and a light absorbing area. Thus the light emitted from a light pen 10 is made incident into the path 2a to actuate the matter 14a and detected by the means 8a after passing through the path 2a. The fluorescent light of the matter 14a is not absorbed by the matter 14b and therefore the matter 14b never emits the light.