Optical reader

Abstract

Abstract PURPOSE: To make it possible to consider all parts, judged to be colored by human eyes, to be in dropout color, by a two or three-system photoelectric converting element that has high sensitivity in the wavelength range of blue, green or red. CONSTITUTION: Spectral reflection factors of white, black, reddish color, and bluish color papers are shown by curves 1, 2, 3 and 4 respectively. When the spectral sensitivity of an optical system is in a wavelength range of red (6,000W7,000Å), photoelectric converting element 5 scans character 50 in black on a sheet, and consequently character frame 51 in blue which should be dropout color changes to black level 53, so that output (a) can be obtained. Next, a photoelectric converting element with high sensitivity in a wavelength range of blue (4,000W5,000Å) in parallel to the above-mentioned scanning scans the character, and consequently the part of character frame 51 has a reflection factor close to that of white and changes to white level 54, thereby obtaining output (b). For the purpose, outputs (a) and (b) are both checked; a decision on black when outputs (a) and (b) are both black or white when white is made to obtain output (c). COPYRIGHT: (C)1981,JPO&Japio

Inventors

• 👤 Taketo Toyoda
• 👤 Hidetoshi Ueda

Bibliographic Details