JPH0238983B2 - - Google Patents

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention relates to a method for determining the type of barcode in a barcode reader, and more specifically, a method for determining the type of barcode based on the start bit and end bit of the barcode. Regarding.

(Prior art and its problems) Currently, there are multiple types of barcodes, and a dedicated barcode reader is required for each type of barcode reader. You have to sort it to the reader that corresponds to the type, and just looking at the barcode doesn't work.
It was difficult to sort them out because it was difficult to distinguish between their types.

However, each type of barcode has its own characteristic start bit and end bit, and some also have a center bit, so the type of barcode can be determined by selecting the start bit, end bit, or center bit. I can do it.

The table shows the characteristics of the start bit, end bit, and center bit in terms of the pattern of each bit of the input signal.

Accordingly, the present invention enables the central processing unit of a barcode reader to determine the type of barcode, and enables one barcode reader to read barcodes of multiple types of code systems. The purpose is to improve the efficiency of judgment work.

(Means for Solving the Problems) In order to solve the above problems, the present invention converts a barcode pattern into a predetermined electrical input signal and inputs it, and also stores and holds the input signal,
The start bit pattern and end bit pattern of each barcode type are stored in a barcode pattern memory connected to a central processing unit that reads the input signal, and the central processing unit reads the input signal's start pattern or start pattern and end bit pattern. The barcode type is determined by comparing the signal pattern at a predetermined position with the start bit pattern and end bit pattern of the barcode pattern memory, and the stored input signal is deciphered based on the determined result. shall be.

Either a start bit or an end bit may be used in the start pattern depending on the reading direction of the bar code.

Further, the determination of the start and end of the input signal is performed by checking a predetermined amount of no-signal portion before the start and after the end.

(Example) Examples of the present invention will be described below based on the drawings.

In the figure, a is the optical input signal section of the barcode reader.
b is an electric signal converter, c is a waveform shaping circuit, d is a digital analyzer, e is a central processing unit, and f is various barcode pattern memories.

The optical input signal section a is the reading section of the barcode reader, and uses a fixed scanner, pin reader, or handheld wondry reader to detect the width and spacing of the barcode bars as the amount of light reflected, and outputs an electrical signal. The converter b converts it into an electrical signal.

The waveform shaping circuit c shapes the waveform of the electrical signal and inputs it to the digital analysis circuit d.

The digital analysis circuit d compares the waveform-shaped electric signal with a predetermined clock pulse and performs comparison correction, that is, in order to check how many clocks constitute one module (the minimum unit of brightness and darkness). Converts to a digital signal corresponding to the pulse.

The central processing unit e stores the digital signal,
Even if one module of the signal is the same code, the signal width of one module differs depending on the reading speed of the optical input signal part a or the magnification ratio of the barcode, so the average number of clocks for one module to read this is The signal is converted into a ratio-corrected ratio signal by . Then, this ratio signal is stored, and the code type is determined using the code determination method described later, and the entire stored ratio signal is deciphered according to the determined code type, and the bar code is The information contained in the data, that is, information such as numbers, characters, symbols, etc., is output as output data.

The various code pattern memory f stores the patterns of the start bit, end bit, and center bit of the ratio signal in the various bar codes mentioned above, such as JAN code, NW-7 code, Mitsubishi code, etc., and also stores numbers, numbers, and numbers according to the type of bar code.
It stores the number of bits constituting information such as characters and symbols and their interpretation patterns.

For JAN codes, the starting position of the center bit pattern (the 32nd bit for 8-digit JAN codes, the 46th bit for 13-digit JAN codes) is also stored.

The central processing unit e stores the pattern of the ratio signal of the barcode, and stores the start bit pattern of the signal, or the start bit pattern and the signal pattern at a predetermined position in the various barcode pattern memories. start bit,
The type of barcode is determined by comparing each pattern of end bits or center bits.

The method of determining each barcode type will be explained below.

First, in the case of the JAN code, the start bit and end bit patterns are both represented by "1.0.1" as shown in the table above (represented by thin black → 1, thin white → 0; the same applies hereinafter). however,
In the JAN code, the first bit of the data that comes immediately after the start bit and the last bit of the data that comes just before the end bit are always ``0'', so when reading the JAN code, it is possible to determine whether the direction is the start bit or the end bit. Even if you read from , it will always start with "1.0.1.0."

In this way, regardless of whether you read the barcode from the start bit or the end bit, the only ones that start with "1.0.1.0" are the JAN code and code 2/7 as shown in the table above, so the start bit By reading the bit or end bit, it is possible to distinguish between the JAN code and code 2/7 and other codes. Furthermore, since all codes other than the JAN code and code 2/7 have different start bit and end bit patterns, these codes can be distinguished by reading the start bit and end bit.

In other words, if the first data sequence of the ratio signal of the read barcode is (1) "1.0.1.0", the start bit or end bit of the JAN code, or part of the start bit or part of the end bit of code 2/7. .

Therefore, JAN code or code 2/7.

(2) In case of "1.0.1.1.1.0.0.0" NW-7's start bit.

Therefore, NW-7.

(3) In case of "1.0.0.0.1.0.0.0" End bit of NW-7.

Therefore, NW-7.

(4) For "1.0.0.1" Mitsubishi code start bit or end bit.

Hence the Mitsubishi code.

(5) In case of "1.0.0.0.1.0.1.1.1" Code 39 start bit.

Therefore, code 39.

(6) In case of "1.0.1.1.1.0.1.1.1" Code 39 end bit.

Therefore, code 39.

(7) For "1.1.1" Start bit or end bit of code 2/5.

Therefore, code 2/5.

By reading the start bit and end bit,
JAN code and code 2/7 and NW-7, Mitsubishi,
It becomes possible to judge each code of code 39 and code 2/5.

To explain the discrimination between JAN code and code 2/7, the data pattern when code 2/7 is read from the start bit side is "1.0.1.0.1.1.1.0.1.1.1 ”. Here, JAN
If you remove the start bit or end bit of the code, ``1.0.1'', it becomes ``0.1.1.1.0.1.1.1''. If this code were a JAN code, one digit of the JAN code consists of 7 bits, so "0.1.1.1.0.1.1""1...." (the first data pattern ) (next data pattern), but in the case of JAN codes, the data to the left of the center bit (start bit side) always starts from "0", so the above As seen in (the following data pattern), the data does not start with "1", and the data "0.1.1.1.0.1.1" does not occur immediately before the end bit of the JAN code. Similarly, when code 2/7 is read from the end bit side, it is "1.0.1.0.1.0.0.0.1.1.1", so remove the JAN code start bit or end bit "1.0.1" from here. and "0.1.0.0.0.1.1""1...." (first data pattern) (next data pattern), but in the case of JAN code, as seen in (next data pattern) Data never starts with ``1'', and data with ``0.1.0.0.0.1.1'' never occurs immediately before the end bit.

Therefore, regardless of whether the barcode is read from the start bit or end bit,
Since there is no such data pattern in the JAN code, a barcode with such a data pattern can be determined to be code 2/7, and if it does not correspond to that, it can be determined to be a JAN code. be able to.

Additionally, in the case of JAN codes, as mentioned above, data to the left of the center bit (start bit side) always starts with "0", and data to the right of the center bit (end bit side) always ends with "0". Therefore, regardless of whether the JAN code is read from the start bit or the end bit, the data at the 11th bit is always "0". On the other hand, in the case of code 2/7, the data of the 11th bit is always "1" regardless of whether it is read from the start bit or the end bit. Therefore, if the data sequence of the optical head of the ratio signal of the read barcode is "1.0.1.0", it can be determined by simply checking the data of the 11th bit. That is, the 11th
If the bit-th data is “0”, the JAN code,
If the data of the 11th crack is "1", it can be determined that the code is 2/7.

Also, since JAN codes always have a center bit (for 8-digit JAN, the 4 bits starting from the 32nd bit; for 13-digit JAN, the 4 bits starting from the 46th bit), determine the JAN code according to the above method. In this case, a judgment error can be detected by confirming the existence of this center bit.
In other words, in the case of an 8-digit JAN code, the center bit starts from the 32nd bit, so the number of start bits (3 bits), the number of bits for one digit (7 bits), and the number of digits (4 digits) are 3. bit + 7 bit x
Confirm that the center bit pattern follows 4 digits = 31 bits.

FIG. 2 shows the ratio signal 1 when reading the JAN code by the brightness and darkness of each bit. In the figure, 2 indicates a start bit, 3 a start bit, 4 an end bit, and 5 a data bit.

Furthermore, for codes other than JAN codes, the start bit and end bit have different patterns when read from each side, so after determining the type of barcode according to the method described above, the start bit or end bit is Check to see if it is.

For codes other than JAN codes, the type of barcode is determined by comparing the start bit and end bit patterns of the ratio signal with various barcode pattern memories, and then the end bits make up the digits of the barcode. Check whether the data starts at a position that is an integer multiple of the number of bits to be processed plus the number of start bits.

When reading a barcode with a barcode reader, if the barcode is read diagonally across the barcode, the start bit or end bit of the barcode may not be read. In this case, since the start pattern of the ratio signal is not a start bit or an end bit, it is normally impossible to determine, but the start pattern of the ratio signal read by chance may match the start bit or end bit of a certain code. For this reason, after determining the type of single-player chord as described above, it is further confirmed whether or not this determination was correct based on the determined result, and finally the type of chord is determined.

After the code determination, the central processing unit e reads the entire ratio signal according to the reading pattern of the corresponding barcode stored in the barcode pattern memory f, and reads the digits included in the barcode. , characters, symbols, etc. as output data. In this case, the reading is performed sequentially from the start bit side regardless of the direction in which the barcode is read.

Note that if the type of barcode cannot be finally determined and the barcode that has been read cannot be read, that fact is output.

(Effects of the Invention) Since the present invention is configured as described above, it is possible to easily, accurately and efficiently perform the type determination of barcodes of a plurality of code systems using one barcode reader.

[Brief explanation of drawings]

Figure 1 is a block diagram of a barcode reader that embodies the barcode type determination method of the present invention;
The figure is an explanatory diagram showing the ratio signal pattern when reading the JAN code by the brightness and darkness of each bit.
It is. In the figure, e...Central processing unit, f...Various bar code pattern memories, 1...Ratio signal, 2...
...Start bit, 3...Center bit, 4...
...end bit.

Claims (1)

[Claims] 1 The barcode pattern is converted into a predetermined electrical input signal and inputted, and the input signal is memorized and retained, and each barcode type is stored in a barcode pattern memory connected to a central processing unit that reads the input signal. A start bit pattern and an end bit pattern are stored, and the central processing unit compares the start pattern of the input signal, or the start pattern and the signal pattern at a predetermined position, with the start bit pattern and end bit pattern of the barcode pattern memory. A method for determining the type of barcode in a barcode reader, comprising: determining the type of the barcode using a barcode; and reading the stored input signal based on the determined result.