| 摘要 |
PURPOSE:To attain multi-gradation read by irradiating each illuminous element different in illumination amount to a respectively different adjacent spot, receiving the reflected light by plural light receiving elements, and discriminating the size of its output in comparing with a single reference value. CONSTITUTION:When signals are inputted respectively in drive circuits C1-C16 of a read head 19, illuminous elements L1-L16 illuminate and irradiate each adjacent spot D1-D16 on the form through fibers T1-T16. Further, the end of the light receiving fibers R1-R16 confronted with the form receives the reflected ray of spot D1-D16, and the photodetecting elements P1-P16 are connected with other end to input in amplifier A1-A16 by receiving the reflected light and changing it into a signal in proportion to the amount of light. Further, compared with a single reference Vth by comparators K1-K16, an H level SG signal is outputted to a CPU31 when it is bigger than Vth, and an L level SG signal is outputted to the CPU31 when it is smaller than Vth. In case of H level, the amount of light of spot D is reflected more than the fixed amount, and the reflected light is neutral color nearly white, but it means the neutral color nearly black when L level.
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