摘要:
In an optical bar-code reader, an optical scanner (11) optically scans a bar code (1) to obtain optical power of light reflected from white bars and black bars of the bar code (1), a differentiation unit (22) calculates a differential of the optical power to obtain a differential waveform, a dividing unit (23) divides the differential waveform into a positive waveform and a negative waveform, a bar-code correcting unit (24, 25) calculates correct widths of black bars in the bar code from the positive waveform and the negative waveform to create corrected bar-code data, and a converter (28) converts the corrected bar-code data into character data that is an array of numerals and letters.
摘要:
Demodulated data B containing the whole of a right block and a part of a left block is obtained after demodulated data A containing a start guard bar (SGB) and based on a division reading process has been at first obtained. When demodulated data C containing an end guard bar (EGB) and numerical data of three characters is thereafter obtained, the demodulated data C is aligned with modulus 10-OK data obtained by synthesizing the demodulated data A with the demodulated data B on the basis of the end guard bar (EGB), and compares the tenth through twelfth characters (of the numerical data) of both of the data with each other. As a result of this comparison, if the tenth through twelfth characters (of the numerical data) of both of the data are coincident with each other, an identical character counter is incremented.
摘要:
The present invention introduce a bar code reader capable of inferring data coded into one character failing in demodulation when one character can not be demodulated. The CPU demodulates the data obtained by reading bar code for each data character. Concerning the data character failing in demodulation, bar width data for four bars before demodulation is stored in the temporary saving buffer. When 11 data characters are successful in demodulation, the CPU calculates back the modulus 10 check based on the demodulated data corresponding to 11 data characters, and infers a value of the demodulated data corresponding to the data character failing in demodulation. The CPU, when the data character failing in demodulation is contained in the left data block, infers an ODD/EVEN configuration of the demodulated data corresponding to the data character failing in demodulation based on five pieces of demodulated data corresponding to data characters successful in demodulation in the left data block.
摘要:
A bar code reading method deals, as valid data, with demodulated data obtained by synthesizing demodulated data obtained by reading a first data block A of an upper stage of a bar code (having two column codes structured by arranging WPC codes up and down in two columns) with demodulated data obtained by reading a second data block B of the upper stage, and demodulated data obtained by synthesizing demodulated data obtained by reading a first data block C of a lower stage of the bar code with demodulated data obtained by reading a second data block D of the lower stage, only if both of the demodulated data obtained by reading the first data block A of the upper stage and the demodulated data obtained by reading the first data block C of the lower stage, contain a portion corresponding to data characters of the second data block (B, D), and further only if these sets of demodulated data are different from each other.
摘要:
A semiconductor laser driving circuit has a semiconductor laser (1) for emitting a laser beam according to a drive power. A photodetector (1b) is provided for effecting photo-electric conversion of the laser beam to output a corresponding electric signal. A monitoring circuit (101) is connected for monitoring the electric signal to output a monitor signal indicative of variation in intensity of the laser beam. A controlling signal (102) is connected for comparing the monitor signal with a given reference signal to output a control signal according to difference therebetween. A powering circuit (103) is operative according to the control signal to apply to the semiconductor laser a drive power effective to eliminate the difference. An abnormality detecting circuit is provided for comparing the monitor signal with a given limit signal which is set defferent from the reference signal to detect any abnormality and output a corresponding signal.
摘要:
A scan beam formed by the optical scanning unit is divided by the first scan beam dividing unit and the second scan beam dividing unit. The first scan beam dividing unit and the second scan beam dividing unit are disposed in such a manner that the scan beams divided by the first scan beam dividing unit traverse a rotation axis of the optical scanning unit before reaching the second scan beam dividing unit.
摘要:
A method of reading a bar code (7) based on bar-code data obtained by scanning said bar code (7) with light (L2), comprises the steps of: a) obtaining bar-code data; b) obtaining a number as to how many bar data are provided in at least one of a preceding portion and a following portion of said bar-code data; and c) accepting said bar-code data as valid data when said number is smaller than a predetermined number.