JPS6215677A - Bar code reader - Google Patents

Abstract

PURPOSE:To detect quickly and accurately the start position of a bar code by supposing the start while margin and deciding the left, center and right reference bars respectively. CONSTITUTION:A white bar 3, for example, having the larger width than the prescribed value is supposed as the left start margin. Then the sum of the width of the white and black bars 3, 5 and black bar 6 following the white bar 3 is obtained. While the total bar width equivalent to the following one character is obtained. Then the bars 4-6 are decided as the left reference bars when the ratio between both total sums is less than the prescribed value. Then the right and center reference bars are decided in the same way. When it is decided that the above-mentioned deciding processes are correct, the bar 3 is decided as the left margin. Then the decoding process is started at the position of the bar 3. Thus it is possible to detect quickly and accurately the start position of a bar code.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention uses an image sensor or the like to electrically scan a code,
umbering), EAN (Europe A
rtic, [eNumbering).

UPC(UniversajJ Product C
This invention relates to a barcode reading device that reads each type of barcode.

BACKGROUND ART FIG. 2 is a diagram showing the structure of JAN, EAN, UPC, and standard type barcodes. In the same figure, 2-1°2-2.
2-3 is the left, center, and right reference bars; 2-4° and 2-5 are the left bright start margin and the right bright start margin. Hereinafter, the light bar will be referred to as a white bar, and the dark bar will be referred to as a black bar. The left and right reference bars 2-1 and 2-3 each consist of three bars of equal width: a black bar, a white bar, and a black bar. The center reference bar 2-2 is composed of a black bar, a white bar, a black bar, and a white bar with equal bar widths. Each reference bar width of 0 or more is left, center, and right when composing one barcode. Each reference bar has the same width. below,
This reference bar width is referred to as one module of the barcode. 2-a to 2-l indicate the numerical value (character) represented by the barcode. One character is composed of two white bars and two black bars, and the total width of the white bars and black bars constituting each character is seven times the reference bar, or seven modules.

The conventional barcode reading method is shown in Figure 2.
- For the barcode IC, by detecting the white per-start margin 2-4 or 2-5 and detecting the left or right reference bar 2-1 or 2-3 following the white per-start margin, the bar code start position can be determined. I was judging.

Problems to be Solved by the Invention However, in the start position detection method, since the start position is fixed, if an incorrect white margin is detected, the following character is decoded, and if decoding cannot be performed, the detection opening margin is set to bar. It was detected that the code start white margin was not present.

Therefore, the conventional example described above has a problem in that it takes time to detect the barcode start position because decoding processing is performed when detecting the barcode start position. The present invention aims to solve the above-mentioned problems by quickly and accurately detecting the start position of a barcode.

Means for Solving the Problems In order to solve the above-mentioned problems, the present invention electrically scans a barcode, and sequentially stores the barcode white bar width data and black bar width data in an apparatus for each scan. an input means for importing into a memory, a means for sequentially detecting white bars of a predetermined width or more from the data in the memory, and each bar detected by the detection means is sequentially assumed to be a start position margin of the barcode, detecting a barcode left (barcode start part) reference bar corresponding to the white margin position, and determining a ratio between bar width data for one character following the detection reference bar and bar width data of the detection reference bar; means for determining the detection reference bar as a left (barcode start part) reference bar when the ratio is within a predetermined range; and means for detecting the barcode center reference bar corresponding to the white margin position; Means for determining a ratio between bar width data for one character following the bar and bar width data of the detection reference bar, and determining the detection reference bar as the center reference bar if the ratio is within a predetermined range; detecting a barcode light (barcode end portion) reference bar corresponding to the white margin position, and determining a ratio between bar width data for one character immediately before the detection reference bar and bar width data of the detection reference bar; means for determining that the detection reference bar is the barcode right (barcode end portion) reference bar when the ratio is within a predetermined range; (Barcode start part) A barcode reader comprising a decoding processing means that determines the white margin position, converts the detected barcode start margin position x D to the barcode data in the memory, and converts the barcode into numerical data. It is a device.

Operation With the above-described configuration, the present invention assumes a start white margin for each barcode of JAN, EAN, and UPC types, performs determination processing for the left reference bar, center reference bar, and right reference bar, and performs each determination processing. If is correct, determine the start position of the barcode. With the above determination process, the start position of the barcode is detected without decoding the barcode, so that the start position of the barcode can be detected quickly and accurately.

Embodiment FIG. 1 is a block diagram showing the configuration of a barcode reading device in an embodiment of the present invention. In FIG. 1, 1 is a light projector, 2 is an image sensor, 3 is an amplifier circuit, 4 is a waveform shaping circuit, 5 is a memory, 6 is a microprocessor, and 7 is a timing generation circuit. A barcode is shown in FIG. 4A, the output of the amplifier circuit 3 when this barcode is observed is shown in FIG. 4S, and the output of the waveform shaping circuit is shown in FIG. 4C.

As shown in FIG. 4C, binarized data corresponding to the white bar width data and the black bar width data are sequentially input to the memory 6 in the order of the white bar and the black bar.

FIG. 6 shows an example of the white bar and black bar manual data in the memory 6 when JAN, EAN, and UPC standard type barcodes are observed. In the figure, white and black indicate bar colors, and numbers at the bottom indicate sequentially input data numbers.

In the barcode reading device of the present invention, for a white bar wider than a predetermined bar width, for example, the white bar 3 is assumed to be the left start margin for the white bar 3, and the following black par 4. For white bar 6 and black bar 6, find the sum of three bars i X = 4 + s -4-6, and (ζ
Here, 3 is data number 3. The bar width of the black bar indicates the number of data modules. ) Find the total sum of the bar width data for the following one character, Y=7-)-8-1-9+10. If the ratio of X and Y, Y/X, falls within a predetermined concave circle, for example 1.5 (x < 3.0, then the black par 4, white bar 6, black bar 6 is determined to be the left reference bar (left reference bar determination processing).

Similarly, for white bar 3, X = 53-1-54 + 55°Y
;56+57+58+59 and l, , Y/X (D ratio t-
If this ratio is within the predetermined range, the black bar 44
．． White bar 46. The black bar 46 is determined to be a light reference bar (phyto reference bar determination process). Furthermore, white/<-3
For, Z=32+33+34+35, Y:36+3
7+38+39 is calculated, and if Y/Z is within a predetermined range, for example 1, O("(2,5), then the white bar 27. Black bar 28° White bar 29. Black bar 30. White Determine bar 31 as the center reference bar (center reference bar determination process) (If each of the above determination results is correct, the white par 3 is determined to be the left start margin, and barcode data 9 to 69 in memory are set as the standard Decode the type barcode and decode the barcode.Also, if the incorrect white bar is assumed to be the start white margin, for example, if white bar 1 is assumed to be the left white margin, the left reference bar total is =2+3+4, and the sum of the first character bar width data is Y=5-)-8-)-7
−) −8. In the M5 diagram, Y/X = 7
If module/10 module=0.7, the result of the left reference bar determination process will be incorrect. Therefore, each determination process is performed on the subsequent starting white margin candidate point, white par 3, and the correct starting position is detected.

FIG. 6 shows an example of input data of white bars and black bars in the memory 6 when JAN, EAN, and abbreviated type barcodes are observed. As shown in FIG. 3, the shortened type barcode data has 4 fewer characters than the standard type. However, since the left, center, and right reference bars have exactly the same format as the standard type barcode, the same determination process as the standard type barcode shown in FIG. 5 can be performed. In Figure 6,
Detection white bar, for example, left reference bar judgment processing for white par 3, X = 4 + 5 + 6, Y near + 8 + 9 + 10
, Y/X. Similarly, write base bar determination processing C: X=44+45+46, Y=40+41+4
2+43, Y/X, center reference bar determination process, Z=24+25+26+27, Y=28+29+3
0+31, Y/Z. Perform each of the above judgment processes,
If each determination result is correct, a shortened barcode decoding process is performed on the barcode data 7 to 43 to decode the barcode.

FIG. 7 shows a barcode reading process flow of the present barcode reading device.

The process shown in FIG. 7 is an example in which the barcode data in the memory is scanned from the barcode loading direction (forward direction) and the barcode start position is detected.

That is, this is an example in which the white margins of the barcode data in the memory shown in FIGS. 5 and 6 are detected in order from the data number ○ direction. In the flow shown in FIG. 7, is the data point larger than the data point shown in process A in FIG. 7? '', and the process of the same drawing is ``Light reference bar judgment process for white bar P'',
Figure 7: By changing each force process to ``Standard type barcode left reference bar determination processing for white bar example'' and ``Reduction type barcode left reference bar determination processing for white bar P'', bar It is possible to scan code data from the opposite direction and detect the position of the barcode from the opposite direction. That is, it is possible to detect the position of the light white margin (s-s, e-s) shown in FIGS. 5 and 6. After right white margin detection, left white margin (5-4, e-4)
can be detected from the write 1 white margin position, so the start position of the barcode can also be detected.

Effects of the Invention As described above, the barcode reading device of the present invention detects the barcode start white margin position and determines whether the barcode is a standard type or a shortened type for the barcode data in the memory. Since the code decoding process is performed, barcode data can be read quickly and accurately, which is an excellent effect.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing the configuration of a barcode reading device according to an embodiment of the present invention, and FIG. 2 shows JAN and EAN. Fig. 3 is a barcode configuration diagram showing the configuration of a standard type barcode for UPC, Fig. 3 is a configuration diagram showing the configuration of a shortened type barcode for JAN and EAN, and Fig. 4 shows the output waveforms of each part of an embodiment of the present invention. Figure 5 is a diagram showing an example of the data captured in the memory when observing a standard type barcode in an embodiment of the present invention, and Figure M6 is a diagram of the shortened type barcode in an embodiment of the present invention. Figure 7 shows an example of data captured in memory when observed.
The figure is a flowchart showing the processing method by the device.01...Light emitter, 2...Image sensor, 3...Amplification circuit, 4... Waveform shaping circuit, 5--memory, 6--microprocessor, 7--timing generation circuit. Name of agent: Patent attorney Toshio Nakao and 1 other person No. 1
Figure 2 Figure 3 Figure 4 (a-) (b) (S

Claims (1)

[Claims] an input means for electrically scanning a barcode and sequentially importing the barcode bright bar width data and dark bar width data into an internal memory for each scan; means for sequentially detecting bars, and each bright bar detected by the detecting means is sequentially assumed to be a start position bright margin of the barcode, and a left reference bar of the barcode corresponding to the bright margin position is detected; , calculate the ratio between the bar width data for one character following the detection reference bar and the bar width data of the detection reference bar, and if the ratio is within a predetermined range, set the detection reference bar as the left reference bar. a means for determining, detecting a barcode center reference bar corresponding to the bright area margin position, and determining a ratio between bar width data for one character following the detection reference bar and bar width data of the detection reference bar; , means for determining the detection reference bar as the center reference bar when the ratio is within a predetermined range; and means for detecting the right reference bar of the barcode corresponding to the bright area margin position, and detecting the reference bar on the right side of the barcode corresponding to the bright area margin position; means for determining a ratio between bar width data for one character and bar width data of the detection reference bar, and determining the detection reference bar as the right reference bar of the barcode when the ratio is within a predetermined range; If each of the above judgment results is correct, the detected bright margin position is determined to be the left bright margin position of the barcode, and the barcode data is determined from the detected barcode bright margin position with respect to the barcode data in the memory. A barcode reading device consisting of a decoding processing means that converts data into numerical data.