| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To read at high speed a ternary bar code for recording a large amount of information. <P>SOLUTION: A method for reading a bar code including an array of first bars and spaces different in reflectance to reading light executes the steps of detecting reflected light from a reading light scan of a bar code to generate a detection signal, generating an envelope detection signal of the detection signal with a time constantτof not more than T/60, where T is the time required to scan the single bar code, attenuating the envelope detection signal at a predetermined rate to generate a reference signal, and generating a first bar signal corresponding to the first bars from an average signal resulting from the subtraction of the reference signal from the detection signal. The method may further execute the steps of generating a differential signal of the average signal, generating a delayed mixed signal corresponding to first and second bars, and generating a second bar signal corresponding to the second bars from the first bar and delayed mixed signals. <P>COPYRIGHT: (C)2010,JPO&INPIT</p> |
