초록 ▼

A bar-code reader having a photoelectric conversion unit for converting reflected light from a bar code into an electric signal and a changing point detecting unit for detecting, from the electric signal generated by the photoelectric conversion unit, a changing point at which a white stripe is chan

A bar-code reader having a photoelectric conversion unit for converting reflected light from a bar code into an electric signal and a changing point detecting unit for detecting, from the electric signal generated by the photoelectric conversion unit, a changing point at which a white stripe is changed to a black stripe in the bar code wherein the bar code is read based on a plurality of changing points detected by the changing point detecting unit. The bar-code reader includes a determination unit for determining, based on measurement of a distance between changing points, whether a changing point is detected as a true changing point at which a white stripe or a black stripe is changed to a black stripe or a white stripe in a bar code or as a false changing point; and a correcting unit for correcting the changing point detected as the false changing point to the true detecting point based on the changing point determined as the true changing point.

대표청구항 ▼

[ What is claimed is:] [4.] A bar-code reader comprising:photoelectric conversion means for converting reflected light from a bar code into an electric signal;a differentiating means for differentiating said electric signal so as to generate a differential waveform signal;changing point detecting me

[ What is claimed is:] [4.] A bar-code reader comprising:photoelectric conversion means for converting reflected light from a bar code into an electric signal;a differentiating means for differentiating said electric signal so as to generate a differential waveform signal;changing point detecting means for detecting, from the differential waveform signal, a changing point at which a white stripe is changed to a black stripe in the bar code or a black stripe is changed to a white stripe in the bar code; anddetermination means for determining whether the detected changing point is a true changing point or a false changing point,wherein said determination means comprises:gate signal generating means for generating a gate signal indicating that a white stripe or black stripe is changed to a black stripe or white stripe in the bar code when the electric signal exceeds a predetermined threshold;pulse signal generating means for generating a pulse signal indicating changing points at which a white or black stripe is changed to a black or white stripe in the bar code;pulse signal count means for counting the pulse signal; andinteger determination means for, when the gate signal indicates that a white or black stripe is changed to a black or white stripe, determining a changing point corresponding to a center of the pulse signal as the true changing point when a number of detected changing points is odd and determining a changing point detected first as the true changing point when a number of detected changing points is even.