JP2853450B2 - Bar code reader - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bar code reader for reading a bar code recorded on an article, and more particularly to a bar code reader for identifying a reading direction of a bar code and outputting identification information.

[0002]

2. Description of the Related Art With the introduction of a POS system in recent years, the identification information of a product is printed as a bar code on the product, mainly in the distribution industry, thereby streamlining transactions. Various types of such barcodes have been put into practical use depending on the application in which the barcode is used. For example, a binary level code 39 (Code 3 of 9) using two types of width differences and an interleaved 25 (Interleaved 2) are used. of 5), a JAN code using a multi-level defined by JIS is a typical example.

[0003] Reading of information from a barcode recorded on a product is performed by a barcode reader.
At this time, the reading direction of the barcode is not limited to one direction. That is, barcodes are not only from one direction,
In some cases, reading may be performed from the opposite direction. Therefore, in such a case, a start bit and an end bit are provided at the end of the bar code so that the reading direction of the bar code can be confirmed (for example, in the case of interleaved 25), or the left end, right end, and center of the bar code. There is also a bar code that is provided with a guard bar and defines an arrangement configuration of a thick bar and a thin bar so that bar code information can be read regardless of the scanning direction of a bar code reader (for example, in the case of a JAN code).

[0004]

Therefore, in a conventional bar code reader, a bar code such as an interleaved 25 having a start bit / end bit can read bar code information only from one direction. The reading operation was complicated. Further, in the case of a JAN code having guard bars at the left end, the right end, and the center of the bar code, the configuration of the bar code is complicated.

An object of the present invention is to enable bar code data to be read from any direction without performing a complicated bar code reading process and without using a bar code having a complicated structure. It is an object of the present invention to provide a bar code reader capable of outputting data in a bar code reading direction.

[0006]

The means of the present invention are as follows. The bar code data reading means 1 (see the principle explanatory diagram of FIG. 1, the same applies hereinafter) detects reflected light of light applied to the bar code and counts the width of the black and white bars, thereby obtaining the bar code information. read.

[0007] The forward / reverse character table 2
A forward-direction character table that stores characters corresponding to barcode data when a barcode is read from a forward direction (one direction), and a character corresponding to barcode data that is read from a reverse direction (a direction opposite to the above-described forward direction). Is stored in the backward character table.

The decoding control means 3 searches the forward / reverse character table 2 based on the bar code information read by the bar code data reading means 1 and converts it into corresponding character data. At the same time, the barcode reading direction is determined based on which table stores the barcode information.

The reading direction storage means 4 stores the reading direction of the bar code determined by the decoding processing control means 3. The output unit 5 outputs the character data converted into characters by the decode processing unit 2 and data indicating that the reading direction of the barcode is in the opposite direction.

[0010]

The operation of the means of the present invention is as follows. The decoding processing control means 3 searches the forward / reverse character table 2 based on the data read from the barcode data reading means 1, and converts the barcode data into corresponding characters. At this time, the reading direction of the barcode is determined based on whether the barcode data is stored in the forward direction character table or the backward direction character table, and the direction is written in the reading direction storage unit 4. The character data converted into characters by the decoding processing control means 3 is output from the output means 5 to the outside. At this time, the reading direction storage means 4 stores data whose reading direction is reverse. If so, data indicating the reverse direction is also output. Thus, data indicating the reverse direction can be output together with the character data.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to FIGS. FIG. 2 is a system block diagram showing the overall configuration of the barcode reader of the present embodiment.
In the figure, a laser beam oscillated from a light projecting unit 6 which is a laser light source is applied to, for example, a bar code 7 printed on a product. The laser beam applied to the bar code 7 is
The light is reflected by the black and white bars constituting the barcode 7 and enters the photoelectric conversion unit 8. The photoelectric conversion unit 8 includes a phototransistor or the like, and converts reflected light from the bar code 7 into an analog electric signal. This analog signal is converted to a binary conversion unit 9.
The analog signal is converted into a digital signal by the binarization conversion unit 9. The data converted into a digital signal by the binarization conversion unit 9 is output to the counter 10 and the counter 10
The white / black width of each bar constituting the barcode is counted. The width data of the black bar / white bar counted in this way is output to the memory 11 and sequentially stored in the memory 11.

The processor section 12 includes a decoding processing circuit 1
3, a character table 14, a flag storage unit 15, and an output buffer 16. Decoding processing circuit 1
A circuit 3 converts barcode data into character data according to a program stored in a ROM (not shown). The character table 14 includes a forward character table 14a and a backward character table 14b.
4b stores, for example, the data shown in FIG. Note that the code system (code type) of the bar code stored in FIG.
Book ("5" bits), 4 spaces ("4" bits)
It consists of. However, each character table 1 in FIG.
Since the data stored in 4a and 14b is composed of 8 bits for both the bar area and the space area, the lower 5 bits are the actual data of the bar in the bar area, and the lower 4 bits are the actual data of the space in the space area. The data "0" is written in other areas. Also,
Data “1” shown in FIG. 4 corresponds to a thick bar code bar, and data “0” corresponds to a thin bar. This correspondence is the same for both the bar area and the space area.

On the other hand, the flag storage unit 15 shown in FIG. 2 comprises a code system storage unit 15a, a digit number storage unit 15b, an error flag storage unit 15c, a forward flag storage unit 15d, and a backward flag storage unit 15e. I have. The code system storage unit 15a is an area for storing the type of code. For example, data indicating the code 39 described above or J
Data indicating an AN code, interleaved 25, and the like are stored. The digit number storage unit 15b stores the number of digits of a character included in one barcode. Further, the error flag storage unit 15c is an area for setting a flag when data read by the photoelectric conversion unit 8 is not barcode data. The forward direction flag storage unit 15d is an area in which a flag is set when the barcode reader is performing a reading process on the barcode in the forward direction. This is an area where a flag is set when reading is performed in the reverse direction.

The output buffer 16 is a circuit that outputs decoded data output from the decoding processing circuit 13 and reverse information indicating that the bar code is being read in the reverse direction.

The operation of reading a bar code in the bar code reading apparatus having the above-described configuration will be described with reference to a flowchart shown in FIG. First, the decoding processing circuit 13 executes a start detection process (step (hereinafter referred to as ST) 1). In this process, as described above, the laser beam emitted from the light projecting unit 6 is reflected by the bar code 7 and the bar code data stored in the memory 11 via the photoelectric conversion unit 8, the binarization conversion unit 9, and the counter 10 is converted. The decoding is performed by the decoding processing circuit 13. That is, when the barcode is read, data obtained by counting the width of the black bar and the width of the white bar by the counter 10 when the barcode is read is sequentially written and stored.
Therefore, even if the decode processing circuit 13 searches the memory 11 at regular intervals, the bar code data is not stored in the memory 11.
(ST2 is N (No)), an error flag is set in the error flag storage unit 15c (S2).
T3). On the other hand, if a barcode is stored in the memory 11 by the above processing, it is determined that there is bar data (ST2).
Is Y (yes)), and the processing (ST4) and the subsequent steps are executed.

That is, first, the decode processing circuit 13 reads one digit (one character) of data from the memory 11 (ST4). Next, the decode processing circuit 13 searches the forward and backward character tables 14a and 14b (ST5), and determines whether one of the tables 14a and 14b stores the same data as the one digit data. (ST6). Here, the same data as the one-digit data read from the memory 11 is stored in one of the tables 14a,
14b does not exist (ST6 is N).
Return to 1). However, if the same data exists in the forward direction character table 9a or the backward direction character table 9b (Y in ST6), the analyzing process of the one digit data is executed (ST7). In this analysis processing, the data read to the decoding processing circuit 13 is converted into the bar code 7 described above.
This is an analysis of whether or not this is the first digit. By this judgment, 1
If it is determined that the data is the digit data (Y in ST7), the forward or reverse reading direction is determined based on which table the data exists in (S7).
T8). For example, in the example shown in FIG.
Is stored in the forward direction bar storage unit as data “00010”.
100 ”is stored, and the data“ 00 ”is stored in the space storage unit.
000100 "is stored, data" 00000010 "is stored in the bar storage unit in the reverse direction, and data" 00000010 "is stored in the space storage unit. When the lower 5 digits are "10100" and the space corresponding portion (lower 4 digits) is "0100", since the data is the same as the data of the numeral "5" stored in the forward character table 14a, the "forward" Is read. Therefore, in this case, the forward direction flag storage unit 15d
Is set to (ST8 → ST9). On the other hand, the bar corresponding portion (five digits) of the data read from the memory 11 is “00101”, and the space corresponding portion (four digits) is “0”.
If it is "010", it is the same as the data of the numeral "5" stored in the backward character table 9b, so that it is determined that the reading is "backward". Therefore, in this case, a flag is set in the backward flag storage unit 15e (ST8 → ST10).

Thereafter, a character determination process is executed (ST11). For example, in the above example, the number “5” is determined by this processing. Thereafter, it is determined from the data of the number of digits stored in the number-of-digits storage section 15b whether the number of digits of the barcode has been reached (ST12). For example, if the number of digits of the characters included in the bar code 7 is six, the determination (ST12) is N because the character of the first digit “5” has only been determined at this point. . Therefore, in this case, the next one digit data stored in the memory 11 is read out to the decode processing circuit 13 (ST4), and the character table 14 is searched in the same manner as described above (ST4).
5). Then, since the character at this time is not the first character (N in ST7), a determination (ST13) is executed to determine whether the previously set forward direction or reverse direction matches the currently read direction. I do. Specifically, the flag stored in either the forward flag storage unit 15d or the backward flag storage unit 15e is read, and it is determined whether the read direction of the previous character matches the read direction of the current character. . If the two directions do not match (N in ST13), the process returns to ST1. on the other hand,
If the two directions match (Y in ST13), a character is determined from the read data in the same manner as described above (ST13).
11) The number of digits is confirmed (ST12), and if the number of digits does not reach the predetermined number of digits, the above processing is repeated (S12).
T12 → ST4 → ST5 →... ST12).

The process is continued as described above, and when the process of determining a character having a predetermined number of digits (for example, the above-described 6 digits) is completed (Y in ST12), a process of outputting a character having a predetermined number of digits is executed. I do. This processing is executed according to the flowchart shown in FIG. 5, and first sets character data in the output buffer 16 (step (hereinafter, referred to as S in FIG. 5)).
1) It is determined whether or not the above-described backward flag is set (S2). Here, if the reverse direction flag is not set (S2: N), the above-mentioned predetermined digit character data set in the output buffer 16 is supplied to the outside (S4). On the other hand, if the reverse direction flag is set (S2 is Y),
The reverse information is set in the output buffer 16 together with the above-mentioned character set in the output buffer 16 (S
3) Output to the outside (S4).

By performing the above-described processing, the bar code can be read in either the forward direction or the reverse direction, and when reading in the reverse direction, data indicating the reverse direction can also be output. Thus, barcode reading processing can be performed extremely efficiently.

In the above embodiment, the case where data based on the code 39 is stored in the forward direction character table 14a and the backward direction character table 14b has been described. It is configured as follows. That is, since the JAN code is composed of fixed 7-digit data per character,
The lower 7 bits of both the odd parity and the even parity are the actual data of the bar code.
The opposite data may be stored in the character table 14b in the opposite direction to the data a.

FIG. 7A is also the same. FIG. 7A shows the case of an interleaved 25 bar code system, in which the actual data is stored in the lower 5 bits per character in both the forward and reverse directions. It is. FIG. 3B shows an example of the case of a coder bar bar code system, and since it has a 7-bit configuration, the actual data is the lower 7 bits in both the forward and reverse directions.

[0022]

According to the present invention, in the bar code reading process, when data is read in the forward direction for each data reading process, only the read result is output,
When reading data in the reverse direction,
The information indicating the reverse direction can be output.

Therefore, for example, even if the direction of the label on which the barcode is printed is affixed in reverse, it is possible to know whether the direction of the barcode is forward or reverse, and to sort according to the direction of the label. Work can be performed efficiently.

Further, the configuration of the barcode itself can be simplified, and the printing process of the barcode becomes easy.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating the principle of the present invention.

FIG. 2 is a system block diagram of a barcode reader according to one embodiment.

FIG. 3 is a diagram showing an example of data of a code 39 stored in a forward character table and a backward character table.

FIG. 4 is a flowchart illustrating a decoding processing operation of the barcode reading device according to the embodiment;

FIG. 5 is a flowchart illustrating an operation of outputting a decoding result of the barcode reader according to the embodiment;

FIG. 6 is a diagram showing an example of JAN code data stored in a forward character table and a backward character table.

FIG. 7 is a diagram showing an example of data of a code 25 and a coder bar stored in a forward character table and a backward character table.

[Explanation of symbols]

 1 bar code data reading means 2 forward / reverse character table 3 decoding processing control means 4 reading direction storage means 5 output means

Claims (1)

(57) [Claims] 1. A bar code reading means for storing both character data corresponding to bar code read data in the forward direction and character data corresponding to bar code read data in the reverse direction. Searching the forward / reverse character table based on a reverse direction character table and the bar code data read by the reading unit;
The barcode data is converted into corresponding character data, and the barcode reading direction is determined based on whether the table in which the barcode data is stored is a forward character table or a reverse character table. Decoding processing control means; reading direction storage means for storing whether the reading direction of the barcode determined by the decoding processing control means is forward or reverse; and character data converted by the decoding processing control means; Output means for outputting the backward direction data stored in the reading direction storage means.