JPS6233630B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a bar code symbol reading device, and more particularly to a bar code symbol reading device using a hand scanner.

Conventionally, this type of barcode/symbol reading device uses a stationary scanner to read barcodes/symbols, but due to its nature, it is very expensive, has a large external size, is inconvenient to carry, and is difficult to operate. It has the disadvantage of poor performance, making it unsuitable for devices that are required to be inexpensive and compact, such as handy types. SUMMARY OF THE INVENTION An object of the present invention is to provide a barcode reading device that is inexpensive, has a small external shape, and is easy to carry by using a hand scanner.

Another object of the present invention is to scan successive black bars, white bars or white bars from a manually scanned hand scanner.
The combination of black bars is taken as one unit, and the width of one unit of bar scanned immediately before the bar is compared with the width of one unit of bar scanned next to find out how many modules the next scanned bar consists of. It is an object of the present invention to provide a barcode reading device that can minimize the influence of scanning speed fluctuations and the influence of barcode printing accuracy by analyzing whether the barcode printing accuracy is correct or not.

The present invention has a light emitter and a light-receiving element, and by applying it to a printed matter and scanning it by hand, changes in the amount of reflected light obtained from differences in the reflectance of light on the printed matter are converted into electrical signals that change over time. Using a hand scanner, barcode symbols encoded by a combination of a white bar and a black bar consisting of a plurality of modules are scanned as successive black bars, white bars or white bars, and a black bar is taken as one unit and immediately next to the bar. It consists of an analysis device that compares the width of one bar scanned previously with the width of one bar scanned next, and analyzes how many modules the bar scanned next consists of. , an inexpensive and lightweight barcode reading device. The barcode symbol used here is the JAN barcode symbol.
The JAN barcode symbol is a barcode symbol coded by a combination of a white bar and a black bar, which is made up of a single module and is established by JISB9550. Next, embodiments of the present invention will be described with reference to the drawings.

Referring to FIG. 1, in the first embodiment of the present invention, when a hand scanner consisting of a light emitter 2 and a light receiving element 3 is applied to a printed matter 11 on which a barcode symbol 10 is printed and scanned, the light emitted from the light emitter 12 becomes white. Due to the difference in the reflectance between the bar and the black bar, reflected light that changes over time corresponding to the width of each white bar and black bar is obtained.
By receiving the reflected light with a photoelectric element 13 and photoelectrically converting it to obtain an electric signal 15, a hand scanner 14 and an analysis of the photoelectrically converted electric signal 15,
It consists of an analyzer 16 for obtaining decimal numbers. Analysis device 1
6 may be a combination of logic elements or a microcomputer (using a program) as shown in FIG. 2. Here, the analysis method that is a feature of the present invention will be explained.

Before that, we will explain the JAN barcode symbol established by JISB9550. A module is a basic unit for configuring a white bar, a black bar, and a margin, and one character is composed of 7 modules.

The binary symbol representation of modules is such that one module in the white bar is "0" and one module in the black bar is "1". The standard version of the JAN barcode symbol is explained with reference to Figure 3. The standard version of the JAN barcode symbol consists of a left margin consisting of an 11 module white bar and a 3
A left guard bar consisting of modules, a data character on the left consisting of 6 characters, a center bar consisting of 5 modules of "01010", a data character on the right consisting of 5 characters, and a data character consisting of 7 modules. A light guard bar consisting of 3 modules of modular check character "101",
It consists of a total of 113 modules with a light margin consisting of 7 modules of white bars. Further, referring to FIG. 4, the decimal number "0" in the data character on the left corresponds to a 3-module white bar, a 2-module black bar, a 1-module white bar, and a 1-module black bar, that is, " It is composed of 7 modules of 0001101". Similarly, the decimal number "1" in the left data character becomes 7 modules of "0011001", and the decimal number "2" becomes 7 modules of "0010011". The data below the decimal number "3" in the data character is also defined in a similar manner. When reading this module combination of white bars and black bars with the hand scanner 4, the read value of the width of each bar fluctuates due to variations in printing accuracy, the influence of scanning speed fluctuations, etc., leading to a reduction in the reading rate. Therefore, in order to increase the reading rate, it is necessary to read the width value of each bar as accurately as possible.

In addition, the printing tolerance for the JAN barcode symbol is when the white bar and black bar each consist of 1 module (however, in the case of 1 character, 7 modules). Do you want to close it?
This will be explained in accordance with JISB9550 with reference to FIG.

In FIG. 5, a (bar width tolerance) is determined to be ±0.10 mm with respect to the basic module dimension of 0.33 mm, so there is an error of approximately ±33% from ±0.10÷0.33.

In the case of b (edge to edge tolerance), it is determined to be ±0.04mm for the basic module dimension of 0.33mm, so there is an error of approximately ±6% based on ±0.04÷0.33÷2.

In the case of c (character width tolerance), it is determined to be ±0.09mm for the basic module dimension of 0.33mm, so there is an error of approximately ±4% due to ±0.09÷0.33÷7.

In the present invention, a method is used to decode the JAN barcode symbol from the width values of the printed white bar and black bar, so it is desirable to have a small printing tolerance, but it is not possible to print by hand. - Considering the scanning speed fluctuations caused by scanning the scanner 4, reading the bar width in the shortest possible range is less susceptible to scanning speed fluctuations.

Therefore, in the present invention, when reading the width of a bar, the width of the bar is read from b (edge to edge) in FIG. This allows analysis to be performed with the least influence of tolerance, improving the reading rate. Furthermore, regarding the problem of the scanning speed fluctuation mentioned above, if all data characters are analyzed using the left guard bar as a reference, the reading rate will decrease due to the influence of the scanning speed fluctuation. The reading rate is improved by a method that minimizes the influence of scanning speed fluctuations by analyzing the bar width values determined based on the width values of the white bar and the black bar. Next, a method for analyzing the JAN barcode symbol shown in FIG. 4 using the microcomputer shown in FIG. 2 will be described with reference to flowcharts shown in FIGS. 6 to 8.

In FIG. 4, each bar A to P has a module number M _A to M _P , and each bar A to P has a module number M A to M P.
Let T _A to T _P be the time required for scanning, respectively. First, the electric signal 15 scanned by the hand scanner 14 is sent to the CPU via the operational amplifier 21 and analog differentiation circuit 22 in the analyzer 16.
23. CPU23 is ROM for instruction execution
The timer 24 measures the time until the next input signal, that is, the analog differential waveform is input, and sends the result to the analysis RAM 26.

Regarding the detection of the left guard bar, as shown in the flowchart in Figure 6, the left margin is more than twice as wide as the left guard bar, so the width of the previously scanned bar is equal to the width of the bar scanned subsequently.
If it is greater than twice the sum of the widths of the book's bars, it is determined that the previously scanned bar is the left margin, and the next three bars are left guard bars. That is, the condition T _A >(T _B +T _C +T _D )×2 is established. Therefore, it turns out that A is a left guard, and B, C, and D are left guard bars.

Next, the data characters are decoded based on the width values of the white bar and black bar scanned just before, and the values of the basic module dimensions are determined from there, M _B , M _C , Since M _D is composed of one module each due to the left guard bar, the value a of the basic module can be found from (T _B +T _C +T _D )÷(M _B + _MC + M _D ). Before decoding the data character, it is analyzed how many modules each white bar and black bar are composed of.

First, as shown in Figure 7, we analyze how many modules M _E is composed of. T _C + T _D
The value of +T _E is the value of the basic module (T _B +T _C +T
_D ) ÷ (M _B + _MC + M _D ), and from the quotient b, (M
_C + M _D ) is subtracted to obtain the value C of M _E. If the remainder d
If , the basic module value (T _B + T _C + T _D ) ÷
(M _B + M _C + M _D ), if the remainder d is 1/2 or more of the basic module, add 1 to the value of M _E to 1/2
If it is less than that, M _E is left unchanged.

Next, the method to find the value of M _F is (T _D + T _E + T _F )
Find ÷(M _D +M _E +M _F ) as the basic module.

(T _D + T _E + T _F ) ÷ {(T _C + T _D + T _E ) ÷ (M _C +
M _D +M _E )}−(M _D +M _E ), the value of M _F can be found.
If the remainder f is obtained, the basic module (T _C +T _D +T
_E ) ÷ (M _C + M _D + M _E ) If the remainder f is 1/2, add 1 to the value of M _F , and if it is less than 1/2, M _F
is the same value. In this way, the data characters up to the center bar are decoded, and from the center bar, as shown in FIG. 8, the data characters on the right side are obtained in the same manner as for the left guard bar.

Decoding from the right guard bar toward the left guide bar can also be performed in a similar manner.

By configuring a hand scanner and an analysis device as explained above, the present invention miniaturizes the barcode reading device for JAN barcode symbols.
This has the effect of providing a device that is lighter in weight, lower in price, and has a higher reading rate.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing one embodiment of the present invention;
Figure 2 is a diagram showing the inside of the analysis device, Figure 3 is a diagram showing the module configuration of the standard version of the JAN barcode symbol used in one embodiment of the present invention, and Figure 4 is an example of the JAN barcode symbol. Figures 5a and 5b are diagrams showing the printing tolerance of each barcode dimension of the JAN barcode symbol, Figure 6 is a flowchart showing left margin and left guard bar decoding, Figures 7 and 5 FIG. 8 is a flowchart showing the termination of data characters. 11... Barcode symbol, 12... Light emitter, 13... Light receiving element, 14... Hand scanner,
15...Electric signal subjected to photoelectric conversion, 16...Analysis device.

Claims (1)

[Scope of Claims] 1. A barcode reading device that reads a barcode symbol encoded with a combination of various white bars and black bars composed of one or more basic modules, comprising: a light emitting body that irradiates light to the bar code symbol; and a light receiver that converts changes in the amount of reflected light obtained from the difference in the reflectance of the white bar and the black bar to the light during scanning of the bar code symbol into electrical signals that change over time. A hand with an element
a scanner; a measuring means for measuring the width of each bar in units of time based on the electric signal obtained from the hand scanner; The measurement times of the measuring means for the th and (i-3)th bars are Ti and T(i-3), respectively.
1), T(i-2) and T(i-3), and the (i-1)th, (i-2)th and (i-th)
-3)-th bar's basic module numbers M(i-1), M(i-2) and M(i-
3), the basic module number Mi of the i-th bar is (T(i-2)+T(i-1)+
Ti))・(M(i-3))+M(i-2)+M(i-
1))/(T(i-3)+T(i-2)+T(i-
1)) - (M(i-2) + M(i-1)),
A bar code reading device comprising: a determining means for determining the type of the i-th bar based on the calculation result.