Information reading system by laser beam

Abstract

Abstract PURPOSE: To subtract two output signals and perform two-dimensional edge emphasis processing of the information having been read by increasing the beam diameter of one of two laser beams of different wavelengths and superposing both to form a spot. CONSTITUTION: The magnifications of the beam expander BE1 and BE2 are so set that the spot diameter emitted from a laser 10 becomes smaller than the spot diameter emitted from a laser 11. The both beams are synthesized in a half mirror 12 to form a scanning spot P on the original G. The reflected light from the original is detected with photo detectors 15, 16 and both signals are subtracted by a subtractor 21, whereby the edge-emphasized signal S 2 is obtained. This yields such an information reading system which is so arranged as to have two-dimensional edge emphasis processing done by subtracting the output signals of the two photo detectors read with the two laser beams of different wavelengths. COPYRIGHT: (C)1980,JPO&Japio

Inventors

• 👤 Hiroyoshi Funato

Bibliographic Details