MARK READER

摘要

PROBLEM TO BE SOLVED: To improve the detection precision of a mark overlapped with an address and printing by detecting the edge of the mark from picture information through the use of different comparison values for plural times and comparing detected edge information so as to remove noise. SOLUTION: The projection part 4 of a picture input part 2 projects light which can emit a phosphor included in transparent ink printed on paper sheets and which includes a specified wavelength. Light emission from the phosphor and that from the paper sheets are made incident on a light-receiving part 5. It converts light into electric signals and an amplification part 6 amplifies the signals. The edge detection part 7 of the mark detection part 3 detects the edge of the mark from an output signal from a picture input part 2. Then, the edge of the mark is detected from picture information of a part where the phosphor is printed by using the different comparison values for more than twice. A noise removal part 8 removes noise which is estimated to be that from a shape and output by comparing detected edge information. A code conversion part 9 converts codes based on edge information of the detected mark.