JPH0765106A - Bar code reader - Google Patents

Abstract

PURPOSE:To analyze only data which are effective as a bar code and to improve the processing efficiency by prescribing the maximum number of data which can be written in a storage means. CONSTITUTION:A measured edge number counted by a width measuring counter 110 is inputted to the CPU 141 of a read analyzing process part 140. The CPU 141 does not write bar code data in a file storage part 30 when the inputted measured edge number is less than the lowest edge number. Consequently, the data which are scanned this time and stored in the data storage part 120 are made ineffective. Further, the CPU 141 calculates the number of write bytes from the inputted measured edge number and compares this calculated write byte number with a prescribed byte number (bank capacity) per storage area (bank). Then when the write byte number exceeds the bank capacity, data exceeding the prescribed byte number are not stored in a bank of the file storage part 130 from the data storage part 120.

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, and more particularly to a bar code reader for scanning a bar code, temporarily storing bar code data in synchronization with the scanning, and sequentially analyzing the data. .

[0002]

2. Description of the Related Art As is well known, a bar code is represented by a band of a group of bar lines having a constant height, which is coded by combining line widths and intervals. It is decided and printed on food, miscellaneous goods, and other products.
FIG. 6 shows an example of the scanning state of the bar code, FIG. 7 shows a configuration example of a conventional bar code reading device, and FIG. 8 shows an operation example of the bar code reading device.

As shown in FIG. 6, a bar code printed on a recording material such as a label and a scanning beam of a bar code sensor (optical sensor, not shown) of a bar code reader are moved relative to each other, and When the reflected light of the scanning beam is received by the light receiving element, a pulsed bar code signal (binarized bar code data) corresponding to the line width and the interval of the bar code is output from the circuit (not shown) of the light receiving element. To be done.

The binarized bar code data obtained by scanning the bar code is sent to the width measuring counter 10 shown in FIG. 7, where bar width information is generated. This bar width information is sent to the data storage unit 20 having two RAMs 21 and 22. The data storage unit 20 is a CPU in the reading analysis processing unit 40.
(Central processing unit) 41 synchronizes with the two RAMs 21 and 2 in synchronization with the scan synchronization signal generated for each barcode scan.
2 is alternately switched, and bar code data, which is bar width information, is stored alternately. At the same time, the CPU 41 controls the reading of the barcode data from the other RAM (for example, 22), which is not the RAM (for example, 21) storing the barcode data, and writing in the file storage unit 30. The file storage unit 30 is composed of a plurality of storage areas, that is, a plurality of banks.

The CPU 41 performs a process as shown in FIG. In scan interrupt processing that occurs at a cycle determined by the scan synchronization signal (scan synchronization signal), the CPU
Reference numeral 41 switches the RAMs 21 and 22 of the data storage unit 20 (step S21) to determine which RA is currently not storing data
Data is read from M and written in any designated bank in the file storage unit 30 (step S24 ',
S25, S28). After this data transfer, specify the next transfer destination bank (steps S30, S31, S32),
Return to the reading analysis main processing.

In the reading analysis process, the CPU 41 fetches the bar code data from the bank (steps S3 and S).
4 ', S5), the data analysis proceeds according to the bar code signal rule (step S9), and the bank is switched every time the analysis is completed (steps S10, S11, S13, S).
14, S15). For further details of the above-mentioned processing operation, for example, Japanese Patent Application Laid-Open No. 3-20818 previously proposed by the present applicant.
No. 8. The step numbers in FIG. 8 are
Corresponding parts are designated by the same step numbers for easy comparison and reference with the flowchart of FIG. 2 according to the present invention described later.

[0007]

However, the conventional bar code reader as described above has the following problems to be solved.

(1) Not only the binary data of the bar code itself, but also the direct light or reflected light of sunlight or light of the projector of the photoelectric switch, or characters printed before or after bar code printing or a label, Depending on the design, a large amount of pseudo-binarized data often occurs. In this case, since the number of data is large, when the data in the RAMs 21 and 22 are written in the file storage unit 30, the data is stored up to the next storage area (bank) or a storage (memory) area used for another purpose. May invade and destroy the contents.

(2) In the scan operation shown in FIG.
There is no bar code in the scan with, but the binary data of the scan is written in the storage area (bank), and the data is transferred to the reading analysis processing unit (CPU) 40.
It is analyzed. Therefore, since the data other than the barcode data is analyzed, it takes a lot of processing time as a whole.

(3) It is general that the reading analysis processing time and the scan cycle cannot be synchronized, and the analysis processing time is longer than the scan cycle. In such a case, the writing of barcode data to the storage area (bank) precedes the reading analysis processing, so new data is also written to the area (bank) where analysis has not finished yet. It may destroy unanalyzed data.

(4) In this type of bar code reader, a polygon mirror is generally attached to the shaft of a motor that rotates at a constant speed, and a laser beam is applied to the mirror surface to scan the bar code surface. However, there was a case where the motor rotation abnormality occurred and the abnormality could not be detected even if the scan speed decreased.

(5) The storage area (bank) has the maximum number of readable digits (eg 32 digits) and the number of bytes (storage capacity)
Is set. However, if the number of digits of the bar code that is actually read is small, the bar code data to be written is small, so there will be space in the storage area (bank), and it will be wasteful that the storage capacity cannot be used effectively. is there.

(6) When the bar code is scanned and read as shown in FIG. 6, of the six storage areas (banks)
The binarized data scanned in FIG. 6 is defective data, and the data of the remaining four scans to is the barcode scanned data. However, if the reading result output from the bar code reading device causes a reading error, it is impossible to distinguish whether the error occurred by analyzing the defective data or the error occurred due to a problem in the analysis process itself. There was a problem.

In view of the above points, an object of the present invention is to enable a period of reading analysis processing and a scan interrupt processing,
Another object of the present invention is to provide a bar code reading device which improves the processing efficiency by analyzing only valid data as a bar code in the reading analysis process.

[0015]

In order to achieve the above object, the present invention uses a bar code data group which is sequentially read from a bar code and binarized in synchronization with a scan synchronization signal to perform a reading analysis process. In a bar code reading apparatus for analyzing the contents of the bar code by means, a storage means having a plurality of storage areas each capable of storing a plurality of synchronized bar code data groups, and a plurality of storage areas are sequentially provided in each storage area. The storage control means for writing the read bar code data group in a fixed order, and the bar code data group stored in the storage area of the storage means each time the analysis processing of the reading analysis processing means ends. A storage unit that sequentially transfers data to the reading analysis processing unit, and the storage control unit can write the maximum number of data in a plurality of storage areas of the storage unit. Defined and, when the bar code data group by the number of data exceeding the number of said maximum data is formed, for the excess data is characterized by performing a control for limiting not to store in the storage area.

Further, preferably, in one form of the present invention, when the type and the number of digits of the read barcode to be read are set, the storage control means corresponds to the type and the number of digits of the barcode. When the number of pulses is calculated, and the number of pulses of the read and binarized barcode data group is smaller than the calculated number of pulses, writing of the barcode data group into the storage means is prohibited. It can be characterized by performing control.

In a preferred embodiment of the present invention, the status of whether or not the data transfer to the reading / analysis processing means is completed in order to read and analyze the bar code data group from the storage means. Storage state storage means for storing a flag indicating a flag corresponding to each storage area, wherein the storage control means refers to the flag and has not completed transfer of data for analysis. Can be controlled to prohibit writing of a new bar code data group.

Further, according to another aspect of the present invention, the storage control means stores the bar code data group and the current scan cycle time of the scan synchronization signal in the storage area of the storage means. Then, when the scan cycle time is out of the specified range, an alarm can be issued.

Further, as another aspect of the present invention, preferably, the storage control means indicates the number of recording areas of the storage means and the maximum number of data that can be stored in one storage area as a bar to be read. It can be characterized in that the number of digits of the code is switched in advance corresponding to the setting.

Further, according to another aspect of the present invention, each time the transfer means transfers the bar code data group stored in the storage area, the transfer means outputs the order number of the transferred storage area to the outside. Can be characterized.

[0021]

In the present invention, the following operations are performed by the above-mentioned structure, and a remarkable operation is obtained.

(1) The number of bytes of data to be written in the storage area (bank) is calculated in synchronization with the scan synchronization signal, and the calculated number of bytes is the maximum number of bytes defined in advance per storage area (bank). When exceeding the number, the excess data is truncated without being written. Therefore, wasteful processing due to analysis of noise data that is not bar code data is eliminated, and processing time is shortened.

(2) Depending on the type and number of digits of the barcode to be read, which is set in advance, as shown in the following items,
Calculate the number of edges (total number of falling and rising edges) of the digitized barcode data. If the actual number of measured edges is less than the calculated number of edges, the barcode data scanned accurately Since it does not exist, the corresponding data is not written in the storage area (bank). Therefore, the processing time is shortened.

Number of ITF edges = 10 × number of digits / 2 +
8 (start / stop code) Coder bar edge number = 8 × digit number CODE39 edge number = 10 × digit number JAN standard (13 digit) edge number = 60, JAN shortened (8 digit) edge number = 44 ( 3) A bank status flag indicating the status of a storage area (bank) that can be used in common in the read analysis processing and the scan interrupt processing is provided, and whether the flag is unsolved or the analysis completed is stored for each bank. Whether or not new data can be written is determined by referring to. Therefore, it is possible to prevent new data from entering the unanalyzed bank and destroying the contents.

(4) The data of the counted scan cycle (time) is written to the storage area (bank) together with the bar code data for each scan interrupt processing which is generated in synchronization with the scan synchronization signal. If the scan cycle is out of the variation allowable range, an alarm is issued because the rotation abnormality of the scan motor has occurred. In this way, an abnormal scan speed can be easily detected.

(5) When reading a bar code, the number of digits is set in advance. If the number of digits set is small at this time, the storage area (bank) is divided and used. As a result, there is no useless space in the storage area, and the storage capacity can be effectively used.

(6) Each time data is transferred from the storage area (bank) of the file storage section to the reading analysis processing section (CPU), the number of the storage area (bank) selected at that time is output to the outside. Therefore, for example, when the reading of the barcode reading result causes a reading error, the cause of the error can be determined based on the bank number.

As described above, according to the present invention, since invalid data and noise data (error data) are excluded before analysis, the read analysis process and the scan interrupt process can be synchronized, and a bar code is used in the read analysis process. Since only valid data is analyzed, there are advantages such as improved processing efficiency.

[0029]

Embodiments of the present invention will now be described in detail with reference to the drawings.

FIG. 1 shows the circuit configuration of a bar code reader according to one embodiment of the present invention, and FIG. 2 shows the operation of this embodiment. 1, the width measurement counter 110, the data storage unit 120, and the file storage unit 130 respectively correspond to the width measurement counter 10, the data storage unit 20, and the file storage unit 30 of FIG. The CPU 141 of the reading analysis processing unit 140 executes scan interrupt and reading analysis according to the processing procedure shown in FIG.

The width measuring counter 110 counts both the rising edge and the falling edge of the binarized bar code data as shown in FIG. 3, and the counted measurement edge number is stored in the CPU 141 of the reading analysis processing section 140. Get caught. The CPU 141 limits the number of bytes to be written from the data storage unit 120 to the file storage unit 130 by limiting the number of write bytes in the scan interrupt processing routine of FIG. That is, the CPU 141 first calculates the number of written bytes based on the number of measured edges taken in (step S25), and the calculated number of written bytes and 1
A predetermined maximum number of bytes (referred to as bank capacity) per one storage area (bank) is compared (step S26). If the number of written bytes exceeds the bank capacity, to prevent the excess from being written,
A limit process is performed to set the number of written bytes to the maximum number of bytes in the bank (step S27). The CPU 141 writes the bar code data in the bank in step S28 described later.
After executing the processes of to S32, the process returns to the main reading analysis process.

In the reading analysis process, first, the minimum required number of edges is calculated in advance according to the type and the number of digits of the barcode to be read (step S1). In the scan interrupt processing routine, the calculated minimum number of edges and CPU
The number of edges captured in 141 is compared (step S
23) If the number of measured edges fetched is less than the minimum number of edges (the minimum required number of edges), the current data is not the accurately scanned barcode data, so writing the barcode data to the bank. Immediately, the main reading / analysis process is returned so that the data stored in the data storage unit 120 is invalidated.

Further, the read analysis processing section 140 has a flag (bank state) in its internal register for grasping the state of the storage area (bank) commonly used in the read analysis and scan interrupt processing as shown in FIG. Flag). In FIG. 4, the flag area numbers 0 to 7 are bank numbers 1.
If the bank status flag is set (= 1) corresponding to ~ 6, it indicates that the bank has not been analyzed (that is, data exists in the bank), and clear (=
0) indicates that the bank has finished parsing (ie,
There is no data in the bank).

The CPU 141 of the reading analysis processing section 140
In the reading analysis process of FIG. 2, after all the bank status flags are cleared to 0 (step S4), the process waits until the bank status flag is set. That is, if the bank status flags are all 0, there is no data for analysis in all banks, and therefore, step S2 of the scan interrupt process.
It waits until data is written in the bank at step 8 (step S5). If the bank status flag is set, the analysis bank number is output (steps S6 to S6).
8) The bar code data of the bank corresponding to the analysis bank number is analyzed (step S9). This analysis is completed (steps S10 and S11), and the bit corresponding to the analyzed bank is cleared before switching the analysis bank number.
The analysis is completed (step S12). Then, in order to switch the analysis bank number (the number of the bank to be analyzed), the number is incremented by 1 (step S1.
3) As a result, when the analysis bank number exceeds the maximum number of 6 (step S14), the number is returned to 1 (step S15), and the process returns to step S5. If the analysis bank number does not exceed 6, the process immediately returns from step S14 to step S5.

On the other hand, in connection with this, in the scan interrupt processing, after the RAM switching processing (step S21), first referring to the bank status flag, if all are in the 1 state (step S22), all the banks are Since there is data already in the bank and it is unsolved, the data is not written to the bank, and the process directly returns to the main reading analysis process. When the bank status flags are not all 1, that is, when there is an empty bank, the bar code data is written to the bank of the write bank number corresponding to one of the empty banks through the processing of steps S23 to S27 described above. After (Step S2
8) Then, the bit of the bank status flag of the corresponding bank that has written the data is set to 1 to bring it into an unanalyzed state (step S29). Then, the write bank number (number of the data write target bank) is incremented by 1 for switching the write target bank (step S3).
0), if the write bank number does not exceed the maximum bank number 6, the process returns to the main reading analysis process, and if the write bank number exceeds the maximum bank number 6, (step S3
1) After returning the write bank number to 1 (step S3
2) Return to the main reading analysis process.

In the scan interrupt process, the CPU 141 stores the cycle data of the scan synchronization signal in the bank of the file storage unit 130 (step S24). Then, in the reading analysis process, the scan cycle data is taken out from the bank before analyzing the bar code data (step S7), and the value of the taken out cycle and a predetermined predetermined cycle fluctuation allowable range (for example, ± 10 from the reference value). If it is outside the permissible range of fluctuation (step S8), it is determined that an abnormality has occurred in the rotation of the motor to be scanned, and an alarm means is output to the outside to notify the user. The alarm means may be, for example, a buzzer or a beep, a flashing lamp, an alarm message on a display, or a combination thereof.

Further, the CPU 141 determines the number of banks according to the set value of the number of digits in the reading analysis process (step S2). For example, the maximum number of read digits of a barcode is 3
If the number of digits is 2 and the digit number setting value is 16 digits, as shown in FIG. 5, each of the banks 131 to 136 is divided into two, and the number of banks is substantially doubled. As a result, the empty area of the bank is eliminated and data can be effectively accumulated.

Further, in step S6 of the reading analysis processing, the CPU 141 outputs the bank number to be analyzed (the number of the bank currently selected for analysis) to the outside (for example, a display) to notify the user.

[0039]

As described above, according to the present invention,
Since the effectiveness of the captured data in reading the barcode is improved, the processing speed can be improved.

[Brief description of drawings]

FIG. 1 is a block diagram showing a circuit configuration of a bar code reader according to an embodiment of the present invention.

FIG. 2 is a flowchart showing an operation procedure of a reading analysis processing unit according to an embodiment of the present invention.

FIG. 3 is a waveform diagram showing the edges of the binarized bar code data for which the width measurement counter of FIG. 1 counts the number of edges.

FIG. 4 is a schematic diagram showing a relationship between a bank status flag and a flag storage area in the case of 6 banks used in an embodiment of the present invention.

FIG. 5 is a block diagram for explaining bank division and bank number switching according to an embodiment of the present invention.

FIG. 6 is a schematic diagram showing a moving direction of a bar code and a scanning line direction of laser scanning light.

FIG. 7 is a block diagram showing a circuit configuration example of a conventional barcode reading device.

FIG. 8 is a flowchart showing an operation procedure of a reading analysis processing unit of a conventional device.

[Explanation of symbols]

 10,110 Width measurement counter 20,120 Data recording unit 21,22,121,122 RAM 23,123 Inversion circuit (inverter) 30,130 File storage unit 131-136 Bank 40,140 Read analysis processing unit 41,141 CPU

Claims (6)

[Claims] 1. A bar code reader for analyzing the contents of the bar code by a reading analysis processing means using a binarized bar code data group which is sequentially read from a bar code in synchronization with a scan synchronization signal. A storage unit having a plurality of storage areas each capable of storing a plurality of synchronized barcode data groups, and sequentially writing the sequentially read barcode data groups in each of the plurality of storage areas. Storage control means, and transfer means for sequentially transferring to the reading analysis processing means a bar code data group stored in the storage area of the storage means each time the analysis processing of the reading analysis processing means is completed, The storage control unit defines the maximum number of data that can be written in a plurality of storage areas of the storage unit, and the data number exceeds the maximum number of data. Over when the code data group is formed, a bar code reader for the excess data is characterized by performing a control for limiting not to store in the storage area. 2. The storage control means, when the type and the number of digits of the read barcode to be read are set, calculates the number of pulses corresponding to the type and the number of digits of the barcode, and the calculated number of pulses. 7. When the number of pulses of the read and binarized bar code data group is smaller than that of the read bar code, a control for prohibiting writing of the bar code data group in the storage means is performed. 1. The bar code reader according to item 1. 3. A flag indicating the status of whether or not the data transfer to the reading / analysis processing means is completed in order to read and analyze the bar code data group from the storage means, corresponding to each of the storage areas. Further, the storage control means refers to the flag to write a new bar code data group to a storage area in which transfer of data for analysis has not been completed. The bar code reader according to claim 1 or 2, wherein the bar code reader performs a prohibition control. 4. The storage control means stores the bar code data group and the current scan cycle time of the scan synchronization signal in the storage area of the storage means, and the scan cycle time is out of a specified range. The bar code reader according to any one of claims 1 to 3, wherein an alarm is generated in the case of. 5. The storage control means sets the number of recording areas of the storage means and the maximum number of data that can be stored in one storage area when the number of digits of a bar code to be read is set. The bar code reader according to any one of claims 1 to 4, wherein the bar code reader is switched correspondingly in advance. 6. The transfer means outputs the rank number of the transferred storage area to the outside every time the bar code data group stored in the storage area is transferred. The barcode reader according to any one of 1.