JPS6229837B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for preventing misreading, and in particular, for example, in a reading device that reads a barcode displaying a product code by scanning it, it is possible to prevent two or more barcodes from appearing on a product by mistake. If displayed, all barcode signals that are input within a certain period of time (for example, while the product is passing through the scanner) are demodulated into characters, and by comparing all of the demodulated characters, it is possible to identify discrepancies. It relates to a misreading prevention method that rejects any misreading.

2. Description of the Related Art In department stores, superstores, and the like, the sales status of a product is automatically managed every time a product is sold in order to facilitate the management of sales amounts, inventory amounts, and the like. One way to automatically manage the sales status of a product is to display the product code as a barcode consisting of an array of black bars and white bars as shown in Figure 1, and to display the product code every time the product is sold. The barcode affixed to the product is scanned and read using a scanner.

By the way, the barcode label displaying the above barcode is affixed to the product corresponding to the barcode, but since this label is affixed manually, sometimes it is attached outside of the regular barcode label. Barcode labels for other products may be affixed by mistake. When scanning such a barcode label with a scanner, when the first barcode scanned is read as originally displayed, the product corresponding to that barcode is treated as sold. As a result, there is no problem when the barcode on a genuine label is read, but if a barcode label for a different product is mistakenly attached together with the genuine label, and this incorrectly attached label is read first. will be misread, resulting in incorrect processing regarding the sale of the product. Note that the above barcode labels may not be affixed at the same position, so the scanner operates so that it can scan from all directions, and also scans the start code, center code, end code, etc. as shown in Figure 1. Sandwiched 2
Two blocks of barcodes are provided to increase the probability that the scan line will completely scan each block of barcodes. The product code is composed of the code a ₁ +a ₂ which is a combination of these two blocks a ₁ and a ₂ .

Therefore, as described above, the present invention solves the problem that conventionally, when a barcode of another product is mistakenly affixed to a product in addition to the regular barcode, there is a risk that the erroneously affixed barcode will be read. In order to improve this, a misreading prevention method is provided in which all barcodes input within a certain period of time are compared and checked to prevent misreading. For this purpose, the misreading prevention method of the present invention is provided in a reading device that scans a display body having character or code information to read the character or code information, and includes an information detection means for detecting the character or code information, and an information detection means for detecting the character or code information. comprising a holding means for sequentially holding detected character or code information, and a comparison means for comparing each corresponding character or code information held in the holding means,
The information detecting means detects all character or code information within a certain period of time, this information is held in the holding means, and the held information is sequentially compared by the comparing circuit to find even one piece of information that does not match. This feature is characterized in that it is treated as an erroneous reading and refused to be read.

Next, an embodiment of the present invention will be described based on FIG. 2 while referring to FIG. 1 showing bar codes such as JIS, UPC, and EAN.

FIG. 2 is a diagram showing the configuration of this embodiment.

In the figure, 1 is a count circuit, 2 is a start signal detection circuit, 3 is a character demodulation circuit, 4 is an end signal detection circuit, 5 is a buffer, 6 is a control section, 7 is a left/right determination circuit, 8 is a code holding section, 9 is the first comparison circuit, 10 is the second comparison circuit, 11 is the AND circuit, 1
2 is an OR circuit.

The counting circuit 1 consists of a first counting circuit 1-0 and a second counting circuit 1-1, and calculates the width value of the black bar and the width of the white bar of the signal obtained by scanning a bar code as shown in FIG. Each width value is counted using clock pulses. That is, when a barcode label is read and scanned by a scanner, "1" is output as a barcode signal for black bars, and "0" is output for white bars. The length of each of these "1" and "0" signals corresponds to the width of the black bar and white bar, respectively, so the lengths of these "1" and "0" signals are determined as described above. Count. These count values are transmitted to a start signal detection circuit 2, a character demodulation circuit 3, and an end signal detection circuit 4.

The start signal detection circuit 2 detects a start signal which is a read signal of a start code S _t indicating the start of the barcode shown in FIG. It detects a start signal based on the numerical value transmitted from 1-1 and outputs a start detection signal. Note that the start code S _t is composed of, for example, a combination of two black bars and one white bar with a predetermined width. In addition,
The start signal detection circuit 2 detects not only the start signal but also the center signal which is the center code reading signal.

The character demodulation circuit 3 demodulates the barcode signal into characters such as numbers or signals, and is configured to demodulate the barcode signal into characters such as numbers or signals. Based on the length value of ``, the corresponding character is demodulated. It also outputs an Even/ODD signal depending on the ratio of the number of black modules. For this purpose, left and right block determination, which will be described later, is used.

The end signal detection circuit 4 detects an end signal which is a reading signal of an end code E _o indicating the end of the barcode shown in FIG. 1, and is connected to the first count circuit 1-0 and the second count circuit 1
It detects an end signal based on the numerical value transmitted from -1 and outputs an end detection signal.
Note that the end signal detection circuit 4 detects not only the end signal but also the center signal which is the center code reading signal. Note that the code systems of the start code S _t and the end code E _o are the same. However, it can be divided into start and end depending on whether there is a long white margin on the left or right side of the sign.

The buffer 5 temporarily holds the character demodulated by the character demodulation circuit 3, and is made of, for example, a RAM.

The control unit 6 operates the character demodulation circuit 3 when the start signal is transmitted, and
Control the buffer 5 to temporarily hold the demodulated value in the buffer 5, and check whether the barcode data is written to the left or to the right of the center of the barcode. It controls the circuit shown in FIG. 2 as a whole, such as controlling the left and right determining circuit 7 for identifying the left and right sides.

The left/right determining circuit 7 determines whether the character transmitted from the buffer 5 is a character in either the _a1 block on the left side of the center code shown in FIG. 1 or the _a2 block on the right side. , the right block and left block can be distinguished from the character structure of the Even/ODD described above.

The code holding section 8 has a plurality of code holding buffers #1a ₁ , #1a ₂ , #2a ₁ , #2a ₂ , and stores the data held in the buffer 5 in advance according to the judgment of the left/right determining circuit 7. The code is stored in one of the predetermined code holding buffers #1a ₁ , #1a ₂ , #2a ₁ , and #2a ₂ .

The first comparison circuit 9 compares the characters stored in the code holding buffers #1a ₁ and #2a ₁ , and outputs the characters to the AND circuit 11 when they match, and outputs the characters to the OR circuit 12 when they do not match. This is what is output.

Similar to the first comparison circuit 9, the second comparison circuit 10 compares the characters stored in the code holding buffers #1a ₂ and #2a ₂ , and when they match, an AND circuit 11 is sent, and when they do not match, an OR circuit 12 is sent. This is what is output to.

Next, the operation of this embodiment shown in FIG. 2 will be explained.

A barcode signal, which is a barcode reading signal shown in FIG.
The length of "1" is counted by the count circuit 1-0,
The length of "0" is counted by the second counting circuit 1-1. When the start signal detection circuit 2 identifies that the input barcode signal is a start signal based on these count values, it generates a start detection signal. This start detection signal is transmitted to the control section 6, and from there a control signal is transmitted to the character demodulation circuit 3. As a result, the character demodulation circuit 3 receives the count circuit 1 transmitted from the start signal.
Based on the length value of "1" and the length value of "0" counted in , demodulation is performed to the corresponding character. The plurality of demodulated characters are temporarily held in the buffer 5. When the center code shown in FIG. 1 is detected by the end signal detection circuit 4, an end detection signal is output. In this case, the center code functions as an end code. At this time, an end signal confirmation signal is transmitted from the control unit 6 to the end signal detection circuit 4 after character demodulation of a predetermined number of digits (here, 4 digits or 6 digits), and then when the center code is detected, an end signal is detected. An end detection signal is transmitted from the circuit 4 to the control section 6. As a result, the control section 6 generates a control signal, and uses this control signal to transmit the demodulated character held in the buffer 5 to the left/right determining circuit 7. The left/right determining circuit 7 identifies whether the transmitted character belongs to the _a1 block or the _a2 block shown in FIG. 1 based on the Even/ODD configuration of the character. If this character is identified as a character of the _a1 block, for example, this character is transferred to the code buffer # _1a1 of the code holding section 8.
is stored in On the other hand, when an end detection signal is generated based on the center code, the start signal detection circuit 2 detects the barcode signal of this center code as the start signal of the _{next a2} block. Then, in the same manner as the processing of the barcode signal of the _a1 block, the barcode signal of the _a2 block is demodulated into a corresponding character by the character demodulation circuit 3, and this is held in the buffer 5. This held character is transmitted to the left/right determining circuit 7 after the control section 6 confirms the end detection signal based on the end code E _o shown in FIG. Here, this character is identified as belonging to the _a2 block and stored in code buffer # _1a2 . In this way, the demodulated character of the barcode written on the barcode label shown in FIG. If so, the barcode signal is demodulated in the same way as above, and the demodulated character is identified as the character in the _a1 block on the left or the character in the _a2 block on the right from the center code of the label, and the code is determined respectively. Cord buffer #2a ₁ , #2a ₂ of holding part 8
is stored in In this way, the demodulated characters of the barcode data of the two labels are held in the code holding section 8. Then, under the control of the control section 6, the characters of the code buffers #1a1 and # _2a1 are compared in the first comparison circuit 9. As a result, the first comparison circuit 9 transmits "1" to the AND circuit 11 if these characters match, and transmits "1" to the OR circuit 12 if they do not match. Similarly, the characters of code buffers #1a ₂ and #2a ₂ are compared in the second comparison circuit 10, and if they match, "1" is transmitted to the AND circuit 11, and if they do not match, "1" is transmitted to the OR circuit 12. be done. And OR circuit 1
2, when "1" is transmitted from at least one circuit of the first comparison circuit 9 or the second comparison circuit 10, that is, when the characters of any of the comparison circuits do not match, "1" is transmitted to the control section 6. is transmitted to. The control unit 6 refuses to read the corresponding barcode. This case corresponds to a case where two different barcode labels are attached to one product. On the other hand, the first comparison circuit 9
When "1" is transmitted from the second comparison circuit 10, that is, when the characters match in both comparison circuits, reading becomes possible, and the character is transmitted from the code holding section 8 to an output section (not shown). If this signal is "1" within a certain period of time, it is assumed that the data has been correctly interpreted and the data latched in #1a ₁ and #1a ₂ is output to the output section. As mentioned above, if a product has barcode labels from other products affixed to it in addition to the regular barcode label, these barcode labels will be scanned and refused to be read. When all the barcode labels affixed to one product are scanned by a fixed scanner, all characters demodulated from the barcode signals of each block input within a certain period of time are compared, and even one character does not match. In this case, reading refusal processing is performed.

As explained above, according to the present invention, all characters demodulated from barcode signals input within a certain period of time are compared, so that when the characters do not match, it can be treated as an erroneous reading. Moreover, this can be distinguished for each reading unit article. Therefore, even if a barcode label of another product is mistakenly attached to a product in addition to the regular barcode label, it is possible to avoid the risk of misreading this label and mishandling the product management.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing an example of a barcode label, and FIG. 2 is a diagram showing the configuration of an embodiment of the present invention. In the figure, 1 is a count circuit, 1-0 is a first count circuit, 1-1 is a second count circuit, 2 is a start signal detection circuit, 3 is a character demodulation circuit, 4 is an end signal detection circuit, 5 is a buffer, 6 is a control section, 7 is a left/right determination circuit, 8 is a code holding section, 9 is a first comparison circuit, 10 is a second comparison circuit, 11 is an AND circuit, and 12 is an OR circuit.

Claims (1)

[Claims] 1. In a reading device that scans a display body having character or code information to read character or code information,
Information detection means for detecting the character or code information, holding means for sequentially holding the character or code information detected by this information detection means, and comparison for comparing each corresponding character or code information held in this holding means. means for detecting all character or code information within a certain period of time by the information detecting means, retaining this information in the retaining means, and sequentially comparing the retained information by the comparing circuit to detect discrepant information. A misreading prevention method characterized in that if there is even one, it is treated as a misreading and the reading is refused.