JPH073669B2 - Barcode reading method and device - Google Patents

Description

[Detailed Description of the Invention] [Technical Field] The present invention relates to a barcode reading method and apparatus.

[Background technology]

There are two types of labels that display barcodes: 8-digit labels and 13-digit labels. 8-digit labels consist of two blocks, left and right, with each block consisting of 4 digits. 13-digit labels consist of two blocks, left and right, with each block consisting of 6 digits. The left block has 7 digits, including the 2-digit flag indicating the figure.

However, when reading a 13-digit label, depending on the way the beam is swung, a 6-digit block may be read as a 4-digit block. As will be described in detail later, conventional technology has had the problem of misreading a 13-digit label as an 8-digit label.

DISCLOSURE OF THE INVENTION

The present invention has been made in consideration of the above-mentioned conventional problems, and has as its object to provide a barcode reading method and apparatus that reduces the rate of misreading.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a diagram showing an 8-digit label, FIG. 2 is a diagram showing a 13-digit label, FIG. 3 is a diagram showing data in the buffer memory, FIG. 4 is a block diagram showing the principle of one aspect of the present invention, FIG. 5 is a block diagram showing one embodiment of the present invention, FIG. 6 is a diagram showing the structure of data output from the demodulation unit 16, FIG. 7 is a diagram showing the structure of data stored in the buffer memory, FIG. 8 is a diagram showing the structure of data stored in the 6-digit memory and the 4-digit memory, FIG. 9 is a flowchart explaining the operation of the central processing unit shown in FIG. 6, FIG. 10 is a block diagram showing another embodiment of the present invention, and FIG. 11 is a flowchart explaining the operation of the central processing unit shown in FIG. 10.

BEST MODE FOR CARRYING OUT THE INVENTION

To better understand the present invention, a conventional bar code reading method and the problems therein will be explained with reference to FIGS. 1-3.

There are two types of labels that display bar codes: an 8-digit label 1 as shown in FIG. 1, and a 13-digit label 2 as shown in FIG.

As shown in Figure 1, the 8-digit label 1 has a left guard bar (LGB) 3, a center bar (CB) 4, and a right guard bar (RGB) 5, and is composed of two blocks 6 and 7. The two blocks 6 and 7 each have a standard value consisting of four digits of data.

On the other hand, as shown in Figure 2, the 13-digit label 2 has a left guard bar 3, a center bar 4, and a right guard bar 5, and is composed of two blocks 8 and 9, each of which has a standard value consisting of 6 digits of data.

The 8-digit label 1 and the 13-digit label 2 are read as follows.

That is, after the barcode is converted into a digital signal by the barcode reader, the demodulated data is stored in a buffer memory. Because the scanning speed of the light beam is high, the barcode can be read by tracing it from right to left or left to right only once.
Barcodes on barcode labels are often scanned multiple times to read them. Therefore, as shown in Figure 3, the buffer memory 10 stores multiple pairs of data, with left and right blocks of data paired together for each read operation. In Figure 3, n scans are performed in one read operation on a 13-digit label 2, resulting in n pairs of data being stored in the buffer memory 10. The circled numbers in the figure indicate the number of digits actually read. For example, in the first scan, only four digits of the supposedly six-digit data were read in the left block, while six digits were correctly read in the right block. The barcode data in each of the left and right blocks in the buffer memory 10 is assigned a flag indicating the number of digits of the data read (see Figure 7).
(See the figure.) The number of digits of the demodulated data held in the buffer memory 10 is determined by the CPU recognizing the number of digits indicated by this flag, and the data is stored separately in a 4-digit memory section and a 6-digit memory section.

If the data output from the demodulator contains data with a number of digits other than 4 or 6, a read error will occur.
The data in the right block is also removed by the CPU.
The data in the digit memory section or the 6-digit memory section is checked for modulus and parity, and data that passes this check is extracted as correct data. After that, among the data that passes the modulus and parity check, data that has the same number of digits on the left and right (i.e., data in the left block and right block) is extracted to the CPU.
The pair of data is sent via the interface to a host device (for example, a data processing device having a processor for processing and managing bar code data).

However, in such a conventional bar code reading method, when reading a 13-digit label, depending on the way the beam is swung, 6-digit data in both the left and right blocks of a pair of data may be read as 4-digit data and stored in the 4-digit memory section (in the case of the second reading and n-th reading in Figure 3). As a result, it is difficult to read a 13-digit label into 8-digit data.
There was a problem with it being misread as a digit label.

In consideration of the above problems, the present invention aims to reduce the rate of misreading in barcode reading by discarding all data stored in the buffer memory as an error when reading a 13-digit label if a 4-digit label is present in the buffer memory.

FIG. 4 is a block diagram illustrating a bar code reading system according to one aspect of the present invention.

In FIG. 4, reference numeral 11 denotes a bar block data generating means for generating a plurality of bar block data by one bar code reading operation, 21N1, 21N2, ... 21N1 denote bar block data memory sections for storing bar code data of left and right blocks constituting the bar code of a bar code label according to the number of digits N1, N2, ... N1, 22 denotes a digit number detecting means, and 23 denotes at least one bar block data storage area 21Ni (i=1, 2...
l) is a data presence/absence detection means for detecting whether data exists or not.

In FIG. 4, a bar block data generating means 11 generates a plurality of bar block data in one reading operation of a bar code whose number of digits is one of a plurality of predetermined standard values.

The digit number detection means 22 detects the number of digits Ni (i
= 1, 2, ..., l) and stores the bar block data in the bar block data memory section 21Ni corresponding to the number of digits.

After all of the bar block data obtained in one reading operation are stored in one of the bar block data memory units, the data presence/absence detection means 23 determines whether data exists in the multiple bar block data memory units. Only when data exists in only one bar block data memory unit and not in the others, is the data read successfully determined and notified to the host device. If data exists in multiple bar block data memory units, the contents of the bar block data memory unit are cleared as a read error. Instead of the bar block data memory unit 21Ni, a means for storing the number of bar block data for each number of digits may be provided. In this case, if bar block data with different numbers of digits are stored in the bar block data number storage means, the contents of the bar block data number storage means are cleared as a read error.

Therefore, if the label displaying the barcode is, for example, either a 13-digit label or an 8-digit label, in the example of FIG. 4, areas 21N1 and 21N2 for storing 4-digit data and 6-digit data are provided as the barcode block data storage area 21Ni,
During a barcode reading operation, if at least one of the left or right blocks is correctly read as 6-digit barcode data, this 6-digit barcode data is stored only in storage area 21N2 and not in storage area 21N1. Therefore, if data presence/absence detection means 23 detects that no data exists in storage area 21N1, it is determined that the barcode to be read is 13 digits long, preventing it from being misread as an 8-digit barcode and reducing the misreading rate accordingly.

FIG. 5 shows an embodiment of the present invention corresponding to the embodiment shown in FIG.

In Figure 5, 11 is a barcode reader and 12 is a light-emitting unit provided within the barcode reader 11. The light-emitting unit 12 outputs laser light, which is shaped into a predetermined beam pattern by a polygon motor (not shown) and is reflected off the barcode. Note that barcodes are assumed to have only 8 or 13 digits. 13 is a light-receiving unit that receives the focused reflected light and converts the barcode into an electrical signal.

An A/D converter 14 differentiates the output of the light receiving unit 13 and converts it into a digital signal. A bar width counter 15 performs quantization and counts the width of the black and white bars of the bar code represented by a digital signal and outputs the count value.

A demodulator 16 demodulates the digital signal output from the bar width counter 15 into a digital signal representing a decimal number. A bar width configuration checker 17 checks the bar width configuration at the same time as demodulation, and stores only 8-digit and 13-digit data in a buffer memory 18. Therefore, the buffer memory 18 holds only the 8-digit and 13-digit data that have been demodulated and whose bar width configuration has been checked.

Light emitting unit 13, A/D converter 14, bar width counter 15, demodulation unit 1
6 and the bar width configuration check unit 17 constitute the bar code data generating means shown in FIG.

Reference numeral 19 denotes a central processing unit (CPU), and memory 20 stores programs necessary for CPU operation as well as a program 20b for performing modulus checks, and is also provided with a 4-digit memory section 21 and a 6-digit memory section 211 as barcode data storage areas. Memory 20 also stores a data presence/absence detection program 20a according to the present invention. The number of digits added to the data read from buffer memory 18 is determined by CPU 19 for each left or right block, and the data is stored in the 4-digit memory section 211 according to the number of digits.
The data stored in the 4-digit memory section 21 or the 6-digit memory section 211 is stored in the 4-digit memory section 21 or the 6-digit memory section 211. The CPU 19 performs a modulus check on the data stored in the 4-digit memory section 21 or the 6-digit memory section 211 using a modulus check program 20b stored in the memory 20, and extracts only data that pass this check. 23 is a 4-digit comparison section, which compares the data stored in the 4-digit memory section 21 or the 6-digit memory section 211 with the data stored in the register 24, which has four digits of data "0" stored in advance.
The data read from the digit memory section 21 is compared with the data stored in the register 25 that has passed the modulus check, and if all the digits match, that is, if the 4-digit memory section
If the data in 21 is all "0", it outputs "1", and if even one digit is different, it outputs "0". 26 is a 6-digit comparison unit, and is a register in which 6 digits of data "0" are stored in advance.
The comparator 23 compares the data in the register 27 with the data in the register 28 that stores the data read from the 6-digit memory unit 211 and that has passed the modulus check, and outputs "1" if all digits match, and outputs "0" if even one digit differs.
The CPU 19 detects the presence or absence of 4-digit data and 6-digit data by using the registers 24 and 25, the comparator 26, and the registers 27 and 28 in accordance with the data presence/absence detection program 20a. Only when 4-digit data is not present, the CPU 19 sends 6-digit data to the host device. In this way, the correct 6-digit data pair is finally detected.
The paired data is sent via an interface to a host device (for example, a data processing device having a processor that processes and manages bar code data).

When reading a barcode with four digits in one block,
Since the digit data cannot be read, there is no need to detect whether or not there is six-digit data.

Next, the operation will be described in more detail.

In one reading operation, the barcode is scanned n times,
The reflected light of the beam that strikes the bar code is converted into an electrical signal by the light receiving unit 13, and then converted into a digital signal by the A/D conversion unit 14. After the bar width of this digital signal is counted by the bar width counter 15, it is demodulated into a digital signal representing a decimal number by the demodulation unit 16, and the bar width configuration is checked by the bar width configuration check unit 17, and only data with one block consisting of four or six digits is stored in the buffer memory 18. The format of the data stored in the buffer memory 18 is the same as that shown in Figure 3.

When reading an 8-digit label, one block is made up of 4-digit data, so regardless of how the beam is swung, it will never be read as 6-digit data, and so all 4-digit data from the bar code data stored in buffer memory 18 that passes the modulus check is stored in 4-digit memory section 21. When performing the modulus check, CPU 19 uses a modulus program for 8 digits.

Therefore, since there is no data in the 6-digit memory section 211, the comparator 26 outputs a signal "1".
Since no data is input from the 6-digit memory section 211 to the register 28, the initial value "0" for 6 digits is input to the register 28, and since the comparison result matches the "0" previously stored in the register 27, the comparator 26 outputs a signal "1" which means that no 6-digit data exists. This signal "1" indicates that the bar code being read is 8 digits long.

On the other hand, when reading a 13-digit label, depending on how the beam is swung, it may happen that the 6-digit data in one block is read as 4-digit data and stored in the 4-digit memory section 21, and a single reading operation may result in a mixture of 6-digit data and 4-digit data being stored in the buffer memory 18, as shown in Figure 3, for example.

In this embodiment, when reading a 13-digit label, it is detected whether data exists in the 4-digit memory section 21, and if so, all data in the buffer memory 18 is cleared as an error.
Since six-digit data exists in the read data from the th...nth times, the CPU 19 stores this six-digit data in the six-digit memory section 211. Using the data presence/absence detection program 20a, the CPU 19 reads the four-digit data from the four-digit memory section 21, stores it in the register 25, and compares it with the value of the register 24 in correspondence with the digits by the comparator 23. The register 24 is previously set to all "0".
Since the four-digit data stored in the register 25 contains a value other than "0", the comparison result is not a match and the comparator 23 outputs a signal "0".
can detect that four-digit data exists in the four-digit memory section 21.

As a result, it is determined that the reading of the bar code on the 13-digit label is an error, and the contents of the buffer memory 18, the 4-digit memory section 21 and the 6-digit memory section 211 are cleared.

In summary, when performing a modulus check, the CPU 19 uses an 8-digit modulus program for the data in the 4-digit memory section 21, and a 13-digit modulus program for the data in the 6-digit memory section 211 (both of these programs are stored in the memory 20 as modulus check programs). Of the data that passed the modulus check, the CPU 19 checks the 4-digit data.
However, as described above, since it is detected that data is stored in the 4-digit memory section 21, it is determined that the reading operation of the 13-digit bar code was an error, and the data in the buffer memory 18, the 6-digit memory section 211 and the 4-digit memory section 21 is cleared by the CPU 19.

In this way, data that may be mistaken for an 8-digit label is excluded, preventing a barcode of a 13-digit label from being mistakenly read as a barcode of an 8-digit label.

FIG. 6 shows in detail the format of one block of data stored in the buffer memory 18.
The 6-digit block data is stored in buffer memory 18.
The data (referred to as data A) is stored in , and a flag indicating the number of digits is placed at the beginning of the data (referred to as data A). As shown as data B, each digit in data A is composed of a parity flag that identifies even or odd parity, a left/right flag that identifies left block data or right block data, and a data value that is a digital representation of the data value of that block (one of 1 to 9). In the case of four-digit data, data A has a digit number flag of 4, and data from is stored. A single read operation obtains multiple pieces of data in the format of data A shown in Figure 7, each of which is assigned a 4-digit or 6-digit digit number flag and stored in buffer memory 18.

FIG. 7 shows data A stored in the buffer memory 18 by one read operation. As shown in the figure,
For each of the n scans, a flag indicating the number of digits and the corresponding half block data are stored in association with each other.

8 is a diagram showing the contents of the left and right blocks of the 6-digit memory 211 and the left and right blocks of the 4-digit memory 21. As shown in the figure, each memory stores an even/odd parity flag, a flag indicating the left/right block, and barcode data.

9 is a flow chart for explaining the operation of the CPU 19 shown in FIG. 5. In the figure, in step 101, the demodulator 1
All data obtained in one reading operation is read from the bar width check unit 17, and in step 102, it is determined whether one block contains four or six digit data.
Data other than the four-digit and six-digit data is discarded in step 103. Then, in step 104, only data with one block of four or six digits is stored in the buffer memory 18.
In this way, a total of n blocks of data are stored on the left and right sides in the buffer memory 18. Next, in step 105, data is read out for each block from the buffer memory 18, and in step 106, it is determined by the digit flag whether the data is four or six digits. If it is four digits, in step 107, it is determined by the left and right flag whether it is a right block or a left block. If it is a right block, in step 108, this data is stored in the right block area (referred to as R-4 data memory) of the four-digit memory section 21, and if it is a left block, in step 109, it is stored in the four-digit memory section 21.
This data is stored in the left block area (referred to as L-4 data memory) of the data buffer 18. Next, a modulus check is performed in step 110, and a parity check is performed in step 111. If the check results in step 112 are NG, it is determined that a read error has occurred, and the contents of the buffer memory 18, R-4 data memory, and L-4 data memory are cleared in step 115, and the read operation is performed again.

If the check is OK in step 112, it is determined whether the data block just read is the last block in memory 18, and if not, steps 105 to 113 are repeated.
When the processing of steps 105 to 113 for the last block is completed, step 114 determines whether there is data in the 6-digit memory section 211. When reading 4-digit data, it is normally impossible to read 6-digit data, so the process proceeds to step 116 and notifies the host device of the data in the left and right blocks of the 4-digit memory section 21. When reading an 8-digit label, step 114 may be omitted.

When it is determined in step 106 that the data is six digits, steps 117 to 126 are executed. That is, in step 117, it is determined whether the data is in the left or right block. If it is in the left block, the left block area (L-6 data memory) of the six digit memory section 211 is filled with data.
If it is a right block, it is stored in the right block area (R-6 data memory) of the 6-digit memory section 211. Then, a modulus check and a parity check are performed in step 120.
In step 121, it is checked whether the check is OK or not, and if the check is NG, the buffer memory 18 and 6
Clear the contents of the digit memory section. If the check is OK,
The process proceeds to step 123 and steps 105 to 123 are repeated until the end of the data block in the buffer memory 18 is reached. When the end of the block is reached, the R-4 data memory or the L-
It is checked whether data exists in the 4-digit data memory. If 4-digit data exists, it means that 4-digit data is mistakenly present in data A when 6-digit data is read, so in step 125,
Clear all 6-digit memory 211 and 4-digit memory 21,
The read operation is performed again. In step 124, the R-4 data is read.
R-6 data only if L-4 data is not present,
The 6-digit data pair in the L-6 data is notified to the host device.

In the above-mentioned embodiment, the 4-digit memory section 21 and the 6-digit memory section 21
1 is provided separately, but 4-digit data is stored in one memory section.
Six-digit data may be stored. In this case, four-digit data,
The address of the storage area where the six-digit data is stored is determined in advance. Then, based on the address of the storage area where the six-digit data is stored, the CPU 19 reads the data from that storage area, stores it in the register 25, and performs the above-mentioned comparison.

In the above-described embodiment, a 4-digit memory section (or a 4-digit data storage area), a 6-digit memory section (or a 6-digit data storage area)
However, the present invention is not limited to this, and it may be possible to determine whether the bar code reading operation is correct by detecting the number of 4-digit data and 6-digit data.

This embodiment is shown in FIG.

In Fig. 10, the same parts as those in the embodiment of Fig. 5 are given the same reference numerals. The difference from Fig. 5 is the memory
The program stored in 201 is a digit presence/absence detection program instead of the data presence/absence detection program 20 in FIG.
30, and instead of the registers 24, 25, 27, 28 and the comparators 23, 26 shown in FIG. 5 for determining whether or not there is four-digit data itself and whether or not there is six-digit data itself, registers 31, 32, 34, 35 and comparators 29, 33 are provided for determining the number of four-digit data and the number of six-digit data.

The operation of the embodiment shown in FIG. 10 will be explained with reference to the flow chart of FIG.

In Fig. 11, steps 201 to 206 are the same as steps 101 to 106 in Fig. 10. In step 206, depending on whether the number is four digits or six digits, step 207 or step 208 is performed.
The number of data items is counted in step 208.
14, or steps 219 to 225, step 10 of FIG.
Execute steps 7 to 113 or steps 117 to 123, and if the read data block is four digits, proceed to step 215
Then, it is determined whether the value of the 6-digit data counter 35 is 0. If it is not 0, the data read by this read operation is deemed to be an error, and the buffer memory etc. is cleared, and only if it is 0, the read data is notified to the host device. Similarly, if the data read is 6 digits, it is determined in step 226 whether the value of the 4-digit data counter 31 is 0, and only if it is 0, the read data is notified to the host device.

The present invention is not limited to 8-digit or 13-digit barcodes, but may be applicable to barcodes of any suitable number of digits, and the number of blocks constituting the barcode is not limited to two as in the above-described embodiment.

[Industrial Applicability]

As described above, according to the present invention, the number of digits in the read bar code data is detected and the bar code data is processed based on this result, thereby reducing the rate of misreading of the bar code data.

Claims (38)

[Claims] [Claim 1] A method for reading a barcode having one of a plurality of predetermined standard values by a single reading operation of the barcode, the method comprising the steps of generating a plurality of barcode block data for the barcode (101-105), detecting the number of digits of each of the plurality of barcode block data (102, 106), and storing the barcode block data in a storage area corresponding to the number of digits of the detected barcode block data (108, 109).
9, 118, 119), a step of detecting whether or not bar-block data is stored in two different storage areas (114, 124), and a step of determining that the bar-code reading operation was an error if bar-block data is stored in two different storage areas (115, 125). 2. The barcode reading method according to claim 1, wherein in the step of generating a plurality of bar block data (101-105), a plurality of left bar block data and a plurality of right bar block data are generated. [Claim 3] The barcode reading method described in claim 2, characterized in that the step (108, 109, 118, 119) of storing the bar block data in the storage area includes a step of storing the detected bar block data in a left bar block data storage area and a right bar block data storage area of corresponding number of digits depending on the number of digits of the detected bar block data and whether the generated bar block data is left bar block data or right bar block data. [Claim 4] A barcode reading method as described in claim 1, characterized in that the step (102, 106) of detecting the number of digits includes a step (102, 103) of discarding bar block data having a number of digits that does not match any of the predetermined multiple standard values. [Claim 5] A barcode reading method as described in claim 1, characterized in that the step (101-105) of generating a plurality of bar block data includes a step (104) of storing the generated plurality of bar block data in a buffer memory. [Claim 6] A barcode reading method as described in claim 1, characterized in that after the step (108, 109, 118, 119) of storing the barblock data in the storage area, a modulus 10 check and a parity check (110, 111, 120, 121) are performed on the stored barblock data. 7. The plurality of bar block data are read out one by one from the buffer memory and the number of digits is detected (10
6) The bar code reading method according to claim 5, wherein: [Claim 8] A barcode reading method as described in claim 7, characterized in that after the step (108, 109, 118, 119) of storing the detected barblock data in a storage area corresponding to the number of digits of the barblock data, a step (113) of determining whether all barblock data in the buffer memory have been read out is performed, and if not, the step (106) of detecting the number of digits of each of the plurality of barblock data and the step (108, 109, 118, 119) of storing the barblock data in a storage area corresponding to the number of digits of the detected barblock data are repeated, and if the result is yes, the step (114, 124) of detecting whether barblock data has been stored in two different storage areas is performed, and if barblock data has been stored in two different storage areas, a step (115, 125) of determining that the barcode reading operation was an error is performed. 9. The bar code reading method according to claim 5, further comprising the step of clearing the contents of said buffer memory when bar block data is stored in two different storage areas. [Claim 10] A barcode reading method as described in claim 5, characterized in that it includes a step (116, 126) of determining that the barcode reading operation is correct and notifying the read data to a higher-level device if no barcode block data is stored in the two different storage areas. [Claim 11] A barcode reading method comprising the steps of: generating a plurality of bar block data for a barcode having a number of digits that is one of a plurality of predetermined standard values by a single reading operation of the barcode (201-205); detecting the number of digits of each of the plurality of bar block data (202, 206); counting the number of bar block data for each number of digits of the detected bar block data (207); detecting whether or not the number of bar block data having two different numbers of digits has been counted (215, 226); and determining that the reading operation of the barcode was an error if the number of bar block data having two different numbers of digits has been counted. 12. The barcode reading method according to claim 11, wherein the step of generating a plurality of bar block data (201-205) generates a plurality of left bar block data and a plurality of right bar block data. [Claim 13] The barcode reading method described in claim 12, characterized in that the step (207) of counting the number of bar block data includes steps (209, 210, 220, 221) of storing the bar block data in a left bar block data number storage area and a right bar block data number storage area of corresponding digit numbers depending on the number of digits of the detected bar block data and whether the generated bar block data is left bar block data or right bar block data. 14. A step of detecting the number of digits (202, 206).
12. The barcode reading method according to claim 11, further comprising a step (203) of discarding bar block data having a number of digits that does not match any of the plurality of predetermined standard values. 15. The step of generating a plurality of bar block data (201-205) includes a step of storing the generated plurality of bar block data in a buffer memory (204).
12. The barcode reading method according to claim 11, further comprising: 16. The method according to claim 1, wherein, after the step (207) of counting the number of bar block data, a modulus 10 check and a parity check (211, 212, 222, 223) are performed on the stored bar block data.
3. A barcode reading method according to claim 3. 17. The bar code reading method according to claim 15, wherein the plurality of bar block data are read out one by one from the buffer memory and the number of digits is detected (205). 18. The method according to claim 18, further comprising the steps of: counting the number of bar block data; determining whether or not all bar block data in the buffer memory have been read; and if not, detecting the number of digits of each of the plurality of bar block data.
6) and the step of counting the number of bar block data corresponding to the number of digits of the detected bar block data, and if yes, detecting whether two different bar block data numbers have been counted (215,
226) and if two different bar block data numbers are counted, determining that the bar code reading operation was an error (216, 227). 19. A bar code reading method according to claim 15, further comprising the step of clearing the contents of said buffer memory when two different bar block data numbers have been counted. [Claim 20] A barcode reading method as described in claim 15, characterized in that it includes a step (217, 228) of determining that the barcode reading operation is correct and notifying the read data to a higher-level device if the number of data of two different bar blocks has not been counted. [Claim 21] A barcode reading device comprising: bar block data generating means (11) for generating a plurality of bar block data for a barcode by a single reading operation of the barcode whose number of digits is one of a plurality of predetermined standard values; digit number detecting means (22) for detecting the number of digits of each of the plurality of bar block data obtained by the bar block data generating means; a plurality of bar block data storage means (21Ni) provided corresponding to the plurality of specified values, respectively; and data presence/absence detecting means (23) for detecting whether bar block data exists in at least two different ones of the plurality of bar block data storage means, wherein each of the bar block data output from the bar block data generating means (13) is stored in the bar block data storage means corresponding to the number of digits obtained in the output of the digit number detecting means (22); and when the data presence/absence detecting means (23) determines that bar block data exists in at least two different ones of the plurality of bar block data storage means, the barcode reading operation is determined to be an error. 22. The bar block data storage means (21Ni)
22. The barcode reading device according to claim 21, further comprising: registers (25, 28) for storing the barcode data in accordance with the number of digits of the detected barcode data; registers (24, 27) for storing all 0s in advance in the same number of digits; and comparison means (23, 26) for each number of digits, and the data presence/absence detection means (23) detects the presence or absence of data by comparing the contents of the registers for each number of digits. 23. The barcode reading device according to claim 21, wherein the digit number detection means (22) includes means for discarding bar block data having a digit number that does not match any of the predetermined standard values. 24. The bar code reader according to claim 21, wherein said plurality of bar block data generating means includes a buffer memory (18) for storing the generated plurality of bar block data. 25. A means for performing a modulus check and a parity check on the stored bar block data after storing the bar block data in the storage area.
22. The barcode reading device according to claim 21, further comprising: b). 26. The bar code reader according to claim 24, wherein said digit number detection means reads out said plurality of bar block data one by one from said buffer memory (18) and detects the number of digits thereof. [Claim 27] The barcode reading device described in Claim 26, characterized in that the data presence/absence detection means includes means for determining whether all bar block data in the buffer memory (18) has been read out, and if not, means for detecting the number of digits of each of the multiple bar block data and repeatedly storing the bar block data in a storage area corresponding to the number of digits of the detected bar block data, and if the result is yes, means for detecting whether bar block data has been stored in two different storage areas, and means for determining that the barcode reading operation was an error if bar block data has been stored in two different storage areas. 28. The bar code reading method according to claim 24, further comprising means for clearing the contents of said buffer memory when bar block data is stored in two different storage areas. 29. The method according to claim 24, further comprising means for determining that the bar code reading operation is correct and notifying the host device of the read data when no bar code block data is stored in the two different storage areas.
A barcode reading device according to claim 1. [Claim 30] A barcode reading device comprising: bar block data generating means (11) for generating a plurality of bar block data for a barcode in a single reading operation of the barcode, the number of digits of which is one of a plurality of predetermined standard values; digit number detecting means (22) for detecting the number of digits of each of the plurality of bar block data obtained by the bar block data generating means; a plurality of bar block data number counter means provided corresponding to each of the plurality of specified values; and digit number presence/absence detecting means (23) for detecting whether or not the number of bar block data exists in at least two different ones of the plurality of bar block data number counting means; each number of bar block data output from the bar block data generating means (11) is stored in bar block data number storage means counted by the digit number presence/absence detecting means (30); and when it is determined by the digit number presence/absence detecting means (30) that the number of bar block data has been counted in at least two of the plurality of bar block data having different numbers of digits, it is determined that the reading operation of the barcode is an error. The bar block data number counting means includes a register for storing the number of bar block data according to the number of digits of the detected bar block data, a register for storing all 0s in advance, and a comparison means, each corresponding to the number of digits.
31. The bar code reader according to claim 30, wherein the content of the register is compared for each number of digits to detect whether or not there is a different number of digits. [Claim 32] A barcode reading device as described in Claim 30, characterized in that the digit number presence/absence detection means (30) includes means for discarding bar block data having a number of digits that does not match any of the predetermined multiple standard values. 33. The bar code reader according to claim 30, wherein said plurality of bar block data generating means includes a buffer memory (18) for storing the generated plurality of bar block data. 34. The bar code reader according to claim 30, further comprising means (20b) for performing a modulus check and a parity check on the bar block data output from said bar block data generating means (13). 35. The bar code reader according to claim 33, wherein said digit number detection means reads out said plurality of bar block data one by one from said buffer memory (18) and detects the number of digits thereof. [Claim 36] The barcode reading device described in claim 35, characterized in that the digit presence/absence detection means (30) has means for determining whether all bar block data in the buffer memory (18) have been read out, and if not, means for detecting the number of digits of each of the multiple bar block data and repeatedly counting the number of bar block data corresponding to the number of digits of the detected bar block data, and if the result is yes, means for detecting whether two different numbers of bar block data have been counted, and means for determining that the barcode reading operation was an error if two different numbers of bar block data have been counted. 37. The bar code reading method according to claim 33, further comprising a means for clearing the contents of said buffer memory (18) when two different bar block data numbers have been counted. [Claim 38] A barcode reading device as described in claim 33, characterized in that it includes means for determining that the barcode reading operation is correct and notifying a host device of the read data if the number of data of two different bar blocks has not been counted.