JPS5935273A - Bar code reader - Google Patents

Abstract

PURPOSE:To read bar code information stably even when the pitch of a bar code and a scanning speed vary, by generating sampling pulses from standard bars and detecting the bar code. CONSTITUTION:When the bar code is printed, two standard bars 23 displaying the print pitch of the bars are printed on both ends 20 and 22 of the bar code 21. The printed bar code including four standard bars 23 is scanned by detector 30 and binary-coded; and signals corresponding to pitches 24 and 26 of a starting bar pulse 20 and an ending bar pulse and widths 25 and 27 sent to a pulse generator 34 to generate sampling pulses from their mean values. The binary- coded signal of the bar code 21 except the standard bar 23 is ANDed by an AND circuit 35 with the sampling pulses and its output is held in a shift register circuit 36 and decoded by a decoder 37, so that the bar code is read out as information.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a barcode reading device suitable for handling a large amount of information.

One method of highly automating logistics transportation systems is the barcode method, in which barcodes are printed or affixed to items, the barcodes are decoded by an automatic reader, and a series of operations from loading to unloading of items is automated.

As a conventional method of this kind, as shown in Fig. 1, a barcode (U) with a start bar (to) added is scanned in a detector (not shown), and a sampling signal calculated in advance from the scanning speed is generated. There has been a device that detects barcode information by sampling the barcode signal using -.

On the other hand, as shown in Figure 82, when printing barcode 01), two standard bars that display bar printing pitch 03) are added as start bars (to), There was a device that generated a sampling signal from a standard bar (14+, C141) of a book and detected a barcode signal.

Conventional barcode reading devices read barcodes in the manner described above, so in order to detect barcodes with a large number of bars that correspond to a large amount of information, it is necessary to set the sampling period and generate the sampling signal. This must be done with high precision, and it is also necessary to print the barcode (11) with high precision, which has the disadvantage of complicating detection and printing and making the device expensive.

This invention was made in order to eliminate the drawbacks of the conventional ones as described above, and when printing a barcode, two standard bars that indicate the printing pitch of the bars are printed on both ends of the barcode, and the barcode is printed inside the detector. By generating sampling pulses from the two sets of standard bars and detecting barcode information, the scanning speed and bar printing pitch can change, and the number of bars can increase as the amount of information increases. Even though
It is an object of the present invention to provide a barcode reading device that can stably and accurately read barcode information.

An embodiment of the present invention will be described below with reference to the drawings.

FIG. 6 shows an example of printing a barcode according to the present invention. In the same figure, - (a) is the start bar, Akira 1)
(2) is the standard bar that constitutes the end bar, (2) is the pitch of the start bar,
C) is the printing width of (on the start bar) - (goods) is the pitch of (on the end bar), 2) is the printing width of (on the end bar), (goods)
is the sampling pulse, and ) is the scanning direction.

FIG. 4 is a block diagram showing an example of a bar food reading device according to the present invention. In the figure, ■ is the detector that detects the bar, @0 is the binarization circuit that binarizes the detection signal from the detector, and ■ is the position of the start bar (company) and the printing width (
c) Detection circuit, - is the end bar? 4 position and print width (
c) Detection circuit, - is the detection circuit, (c) is the pulse generation circuit that generates the sampling pulse signal from the detection signal of each position and width of the start bar) and end bar operation, - is the detector - is an AND circuit that takes control of the barcode signal and sampling pulse signal from (), - is a shift register circuit that holds the signal of the AND circuit (c) with the sampling pulse signal (c), and (b) is a shift register circuit that holds the signal of the AND circuit (c) with the sampling pulse signal (c). barcode signal duder, and these AND circuits)
, a shift register circuit 0 and a decoder (b) constitute a code detection means.

Next, the operation of the above configuration will be explained.

The four standard bars printed with barcodes containing the bar code are scanned by a detector and binarized by a binarization circuit 00. The start bar of the binarized barcode is input to the detection circuit (b), and the detection circuit (b) counts the time from the rise to the fall of each bar signal and from the rise to the rise. The pitch (c) and width (c) of the bar are measured. Similarly, the bar code's end bar pitch () and width (c) are measured by a detection circuit. Each signal corresponding to the pitch (C), H and width (C) of the start bar (sha) and end bar (sha) is sent to the pulse generation circuit -, and the pulse generation circuit ■ is calculated from the average value of each signal. generates a sampling pulse).

Binarized signals of barcode Q0 other than standard bar (c) are:
Take the product of (to the sampling pulse) with an AND circuit,
The result is held in the shift register circuit (g). The barcode symbol is read out as information by decoding the contents of the shift register circuit by the decoder e't).

In this way, the pitch (C), H and width (C) of the barcode (C) are automatically detected, and the average value of each is used to generate a sampling pulse, increasing the scanning speed. In addition, even when the number of bar foods Q0 increases as the amount of information increases, accurate reading operations can be performed stably.

In addition, in the above example, an example was shown in which the sampling pulse () was obtained from the average values of the pitch (value) and (c) of the start bar (product) and end bar (2), but in this pulse)
Each pitch (c), (on the start bar ■ and end bar)
c) and the total number of barcodes.

Further, in the above embodiment, each circuit function is shown for the sake of explanation, but the same effect can be achieved even if the processing is performed by a microcomputer program.

Furthermore, although the above embodiments have been described using an example in which a bar code is printed, the same effect can be obtained not only by the printing method but also by, for example, an engraving method.

As described above, according to the present invention, two standard bars indicating the pitch and width of each bar of the barcode are added at the beginning and end of the barcode that displays the code depending on the presence or absence of bars,
Since the bar code is detected by generating sampling pulses from this standard bar, stable bar code information can be obtained even if the bar code pitch or scanning speed changes.

[Brief explanation of drawings]

Figures 1 and 2 are explanatory diagrams of conventional barcodes;
FIG. 4 is an explanatory diagram of a barcode according to the present invention, and FIG. 4 is a configuration diagram showing an example of a barcode reading device according to the present invention. (Company)...Start bar, G! ])...Barcode, ni)...End bar, (c)...Standard bar-@
4, ni)...pitch, (c), ni)...width, (c)...sampling pulse, ni)...scanning direction, ■
...scanning signal output means, 00...binarization circuit)
, ■...Detection means, -...Pulse generation circuit, ■...
・Sign detection means. In addition, in the figures, the same reference numerals indicate the same or corresponding parts. Agent Makoto Kuzuno (1 other person) Figure 1 Figure 2 Figure 3 Figure 1 So Figure 4 Procedural amendment (I) Commissioner of the Japan Patent Office 16 Indication of the case Japanese Patent Application No. 145911/1982 2, Title of the invention Relationship between barcode reader 3 and the case of the person making the amendment Patent Applicant (1) & The "Detailed Description of the Invention" and "Brief Description of Drawings" columns of the specification to be amended. 6. Contents of amendment (1), the description is amended as follows. (2)

Claims (1)

[Claims] (1) Two pieces of information displaying code information based on the presence or absence of bars arranged at predetermined intervals along the scanning direction, and displaying the spacing between the bars at both ends of the scanning direction. means for scanning a barcode with standard bars added thereto to output a scanning signal; means for binarizing the scanning signal; and means for detecting standard bars at both ends from the binarized signal of the barcode. ,
means for measuring the bar pitch and bar width from the detected standard bars; and means for generating a sampling pulse signal corresponding to the bar code from the measured bar pitch and bar width. A barcode reading device comprising means for detecting a barcode symbol using the binary signal of the barcode and the sampling pulse. (2) Claim 1 wherein the sampling pulse is determined by averaging the pitch and width of the standard bars at both ends.
The barcode reading device described in Section 1. (8) Claim 1 in which the sampling pulse is determined from the pitch between the standard bars at both ends and the total number of bars.
The barcode reading device described in Section 1.