JPH0241697Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a device that automatically determines the type of barcode printed on the packaging of a product.

[Conventional technology]

There are various types of barcodes that express characters etc. using a combination of spaces (white bars) and bars (black bars). 2 spaces and 2 bars with 4 different widths
Using this book, arrange these in black and white order, totaling 7
This is one character as a module (7 units wide),
The JAN code, which expresses one product type with 13 characters, is a widely used barcode, but in addition to this multivalued (more than 2 width types) level barcode, there are also two types of widths, long and short. There is also a binary level barcode that expresses one character by combining the required number of spaces and bars, and indicates the product type using multiple characters.
There are also various types of binary level barcodes, such as those using four black bars, those using five black bars, and those using three black bars.

A barcode expressed by a plurality of characters consisting of a combination of spaces and bars has a start code and a stop code attached before and after it, and these indicate the start and end of the code. FIG. 3 shows the data format of the barcode, and the data section consisting of the first to nth characters is preceded and followed by
A start code ST and stop code SP are attached. The format of the start code and stop code (combination of spaces and bars) also differs for each barcode. Barcodes are read photoelectrically with a reader (pen), as is well known.

FIG. 5 is a block diagram of a barcode reading system in which a barcode pen PEN (generally a barcode reader) is connected to a handheld terminal device TE, and its main functions are shown in FIG. The pen PEN amplifies the photoelectric conversion output of the barcode, shapes it into a rectangular wave, and delivers it to the terminal device TE. The terminal device TE detects the edges (rising and falling) of the rectangular wave input from the pen PEN, starts a counter at the edges, counts the time width of each space and bar, and stores the timer value in memory (Figure 5). RAM). Then, a demodulation operation is performed based on this timer value to decode each character of the barcode, and decoded code data (a group of characters represented by a character code) is output. This part is performed by software processing on the CPU.

By the way, as mentioned above, there are various types of binary level barcodes depending on the number of bars included in one character, such as NW-7 code, each standard code, 3 out of 9 code, Industrial 2 of 5 code, etc.
Therefore, the terminal TE to which the barcode reader is connected
In this case, it is not possible to demodulate a barcode unless the type of barcode is specified.

[Problem that the invention attempts to solve]

For this reason, conventionally the operator used a manual switch (key) to instruct (switch) the barcode type.
However, this method requires the operator to judge the type of barcode each time it is read, which is extremely inconvenient. The type is usually not displayed on the barcode, and it is difficult to determine the type just by looking at the barcode. Since the start code ST added before the first character of the barcode differs depending on the type of barcode, it may be possible to read this with a barcode reader and automatically discriminate it with the terminal TE. However, with this method, there are problems such as dust attached to the start code, which prevents proper analysis, or conversely, when a different barcode type is accidentally analyzed, resulting in a dead end in subsequent processing. The present invention attempts to improve these points.

[Means for solving problems]

The present invention is an automatic barcode type discrimination device in which a character is represented by a combination of bars and spaces, and a start code and a stop code, which are also a combination of bars and spaces, are arranged before and after the plurality of arrays of such characters. means to demodulate the start code of the barcode read this time and the photoelectric conversion output of the first character using the analysis program used last time, and if the start code cannot be demodulated or the first character cannot be demodulated by the demodulation means, the type means for changing to an analysis program for another different barcode, and means for demodulating the second character and subsequent characters of the barcode with the analysis program when an analysis program capable of demodulating the start code and the first character is determined. , and means for storing the type of the analysis program for next use when demodulation of the barcode up to the stop code is successful.

[Effect]

The type of the analysis program used to read the previous barcode and the type of barcode successfully decoded last time are stored in a register, and in order to analyze the barcode read this time, the stored type of analysis program is first used. When used, it is extremely effective as barcodes of the same type are generally read consecutively in many cases.

This experimental analysis (demodulation) target includes not only the start code but also the first character following it. If these can be demodulated, the second character, third character, etc. are demodulated in order, and finally the barcode type in the register is updated (in this case, it does not change). On the other hand, if the demodulation up to the th character fails, the type of analysis program is changed and the attempt is made again. As a result, if the new analysis program succeeds in decoding up to the first character, the program continues to demodulate the second character and subsequent characters. When demodulation is completed to the end, the barcode type in the register is saved for next time use. This will be explained in detail below with reference to illustrated embodiments.

〔Example〕

FIG. 1 is a block diagram showing an embodiment of the present invention, in which 1 is a memory for storing timer values T ₀₁ , T ₀₂ , etc. indicating the width of each space and bar, 2 is a pointer control circuit thereof, and 3 is a Demodulation circuit 4 is a discrimination code register. This judgment code register 4 stores the type of analysis program used last time and the type of barcode, and the analysis program of this type is preferentially used for demodulating the barcode read this time. In the drawing, barcode type analysis programs are shown as barcode 1 demodulation circuit 31, barcode 2 demodulation circuit 32, etc., but these are actually processing program routines of the CPU stored in the RAM shown in FIG. . Among these demodulation circuits 31, 32, ..., the demodulated output of the one specified by the register 4 is judged by the judgment circuit 33, and the
(Good), the code data is 34
written to. On the other hand, if NG (no), the contents of register 4 are updated to the next code type.
The next code type to be set in register 4 may be a simple incrementing method, such as if the first is the barcode 1 demodulator, then the barcode 2 demodulator, and in this case, the order of arrangement of the demodulators is determined by the order in which the demodulators are arranged. It is best to sort them in order of barcode type.

Whether or not the barcode demodulation circuit designated by the discrimination code register 4 is suitable for the barcode to be demodulated is determined by demodulating the start code and the first character. If these can be demodulated, the analysis program is compatible; if they cannot be demodulated, the demodulation procedure is corrected, and if it still cannot be demodulated, the analysis program is not compatible, and the value of the discrimination code register 4 is changed. Demodulation then proceeds to the second, third, ... character, but if there is an error after the third character, the process moves to error processing, and if the final character is demodulated, the stop code is also demodulated. (For details, if you can also detect the following spaces)
The demodulation of the barcode is completed. FIG. 2 is a flowchart showing these processes. When the start code or the first character cannot be demodulated, the timer value is shifted, but this is synchronization, so to speak, by shifting the pointer of the timer value storage memory ₁ in _FIG . Read out these as the start code timer value group, shift them by one and read out T ₀₂ to _{T 10} .
These are used as a start code timer value group. In this example, if demodulation is still not possible after shifting four times, the analysis program determines that it is non-conforming, increments the value in register 4, restores the timer value, and attempts to demodulate from the beginning again. If the barcode cannot be demodulated no matter which analysis program is switched to, the barcode to be read is not compatible with this device, and an error is assumed. To store the barcode type in register 4 for the next recovery, the condition is that the stop code following the last character and the white margin after it are detected, and the barcode to be read is determined to be a regular barcode. do. The start code also serves as a synchronization bit indicating the start point of the following character code, so if demodulation is not possible even after all types of start codes are switched as shown in FIG. 2, it is best to treat it as an error. However, in this case, if there is dust on the start code, demodulation will not be possible and an error will occur.In this case, it is better to read and process the start code again using a barcode reader.

[Effect of idea]

As described above, according to the present invention, the operator does not need to judge the type of barcode and can automatically select an analysis program that is suitable for the object to be read, and the analysis program used last time is given priority for next reading. Since barcodes of the same type are often read successively, the processing time is advantageously shortened. Furthermore, since the barcode type determination target is not limited to the start code but also includes the character part, there are no analysis errors or program selection errors due to dust attached to the start code, improving the reliability of the device as a whole. The processing speed can be improved.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an embodiment of the present invention.
Fig. 2 is a flowchart, Fig. 3 is an explanatory diagram showing the code format of the binary level barcode, Fig. 4 is a schematic explanatory diagram of the demodulation method, and Fig. 5 is a block diagram of the barcode reading system. . In the figure, PEN is a barcode pen, TE is a handheld terminal device, 1 is a timer value storage memory, 3 is a demodulation circuit, 4 is a discrimination code register, 31, 3
2, . . . are bar code demodulation circuits for different code types, and 33 is a determination circuit.

Claims (1)

[Claims for Utility Model Registration] Pre-recovery adjustment of the start code and the reading output of the first character of the barcode read this time in an automatic type discrimination device for barcodes expressed by one of multiple types of encoding methods. means for demodulating with the analysis means used at the time; means for changing to an analysis means for another barcode of a different type if the demodulation means cannot demodulate the start code or the first character; When an analysis program capable of demodulating the first character is determined, a method for demodulating the second character and subsequent characters of the barcode using that analysis program, and when the demodulation of the barcode up to the stop code is successful, the type of the analysis program is determined. and means for storing the information for next use.