JPS6031679A - Bar code reader - Google Patents

Abstract

PURPOSE:To improve reading operability by monitoring a time difference between a forward and a backward direction scans, comparing the read data respectively obtained, and selecting correct data, thereby preventing misread data as well as misleading recognition. CONSTITUTION:A signal processor 6 in an interface part 4 controls a bar code scanner 2; a generation circuit 7 for forward/backward direction scan signals generates forward direction scan signals and backward direction scan signals to the bar code during forward/backward direction scans respectively. An input/ output signal control part 1, on the basis of output of the signal processor 6 as well as of output of the generation circuit 7 for forward/backward direction scan signal, monitors time difference between forward and backward direction scans, and also makes a selective recognition of the read data obtained by respective scans.

Description

[Detailed description of the invention] Industrial application field The present invention is applicable to the distribution field using POS terminals, etc.
The present invention relates to a barcode reading device used in the office processing field, etc., which uses barcodes as a means of inputting data into a computer.

Structure of a conventional example and its problems FIG. 1 shows a conventional bar code reading device. The configuration of this conventional example will be explained below with reference to FIG. 1.

In FIG. 1, 1 is an input/output signal control unit configured with a microcomputer, 2 is a pen-shaped scanner, 3 is a display unit, 4 is an interface unit, and 5 is a transmitter that transmits data read by the scanner 2 to an external device. Department.

Figure 2 shows an example of a barcode, which consists of parts A, 11, B, and C. This barcode consists of two states: a narrow bar or space, and a wide bar or space, and is scanned in the left and right direction with an optical sensor or the like to obtain a time-series signal. The parts A and C have an asymmetrical pattern in the left and right direction, and the mouth part is A.

It has a different pattern from the part C.

Figure 3 is an example of barcode encoding, in which a narrow bar or space is encoded as an "o" and a wide bar or space is encoded as a '1'. This is an example in which parts A and C shown in FIG.

Next, the operation of the above conventional example will be explained. In FIG. 1, when a barcode is scanned by a pen-shaped scanner 2, the data is transferred to the input/output signal control unit 1 through signal processing in the interface unit 4, where the barcode reading result is recognized. The result of the control processing is sent from the input/output signal control section 1 to the interface section 4.
The data is then displayed on the display unit 3 and then transmitted to an external device via the transmitter 5. In the input/output signal control section,
In addition to the above processing, a double reading check of the recognized results is performed. In other words, to determine whether the ζ-code data read by the scanner 2 is the same as the previous scan L&, the recognition result is compared with the previous data recorded in the storage section in the input/output signal control section. If the results are different, it is determined that the data to be input and processed has been correctly scanned, and if the results match, it is determined that the same barcode has been scanned.

In addition, barcodes can be recognized in either the forward scanning direction or backward scanning direction, and various methods have been considered regarding operability, but each method has the following drawbacks. Ta.

■ When operating a pen-type scanner, beginners in particular are unable to scan the barcode label side correctly, and often end up removing the label side and operating it. Furthermore, it was not possible to read the data with a single scan, and a back-and-forth scan operation was often required. When these various operations are performed, devices that do not incorporate double reading inspection logic will read barcode data each time a scanning operation is performed, resulting in the same barcode being read as though multiple pieces of data were being read. 〇■ As a countermeasure for the above, when the same data is input continuously, the signal control section judges that it is treated as - pieces of data, etc. If the reading results were different during forward scanning and backward scanning, they were judged as separate data, and the result was the same as reading multiple pieces of data despite the same barcode. .

Purpose of the Invention The present invention eliminates the drawbacks of the conventional example described above, and aims to improve barcode reading operability by eliminating erroneously read data due to operational errors and input of abnormal data due to erroneous recognition. This is the purpose.

Structure of the Invention In order to achieve the above object, the present invention monitors the time difference between the forward scan and the backward scan, compares and collates the read data obtained from each, and selects the correct data. This has the effect of eliminating erroneously read data and preventing erroneous recognition.

DESCRIPTION OF EMBODIMENTS The configuration of an embodiment of the present invention will be described below along with the -M plane.

In FIG. 4, 1 is a human output signal control unit configured with a microcomputer, 2 is a pen-shaped scanner, 3 is a display unit, 4 is an interface unit, and 6 is a unit that sends read data read by the scanner 2 to an external device. This is the transmitter. In the interface unit 4, numeral 6 is a signal processing unit that passes the scanner signal to the input/output signal control unit 1, and 7 is a circuit unit that generates a forward scan signal and a backward scan signal of the bar code.

FIG. 5 shows the forward scan signal of the bar code t.
/) is an example of a circuit that generates a backward scan signal. In the figure, reference numeral 8 denotes an input terminal into which a barcode reading signal output from the pen-shaped scanner 2 of FIG. 4 is input.

Reference numeral 9 denotes an encoding circuit that performs time-series encoding of the barcode reading signal input to the input terminal 8 as shown in FIG. 1
0 is a shift register that converts the time series data output from the encoding circuit 9 into serial and parallel data. Reference numeral 11 denotes a timing generation circuit that supplies a synchronization timing signal to the encoding circuit 9, shift register 1o, and comparison circuits 12 and 13. Reference numeral 14 denotes a forward storage circuit that stores encoding patterns for forward scans, and 15 denotes a backward storage circuit that stores encoding patterns for backward scans. The comparison circuits 12 and 13 compare the output of the shift register 10 with the outputs of the forward storage circuit 14 and the backward storage circuit 15, respectively, and if a match is detected, the output terminals 12 and 13 output the forward scan signal output terminals 16 and 13, respectively.
It is output to the backward scan signal output terminal 17. The memory circuit 14 stores the coded button shown in FIG. 3, and the memory circuit 15 stores the coded button in the opposite direction to the coded button in the memory circuit 14. A directional scan signal can be obtained.

Next, the operation of the input/output signal control section 1 in monitoring the time difference during forward and backward scan operations will be described with reference to the flowchart in FIG. 6.

■ Wait for the scan operation of "bar j -F" in the read data waiting block.

(2) When read data is generated, the corresponding signal is detected and taken in by the program, and at the same time, a signal representing the state of the device (hereinafter referred to as status) is similarly detected by the program. By designing the signal to include a status indicating the scan direction, the scan direction determination block b branches the processing into forward scan and backward scan.
In the case of forward scan, in the first (previous) scan direction determination block C, it is determined whether or not the scan direction is alternate with the previous scan direction. Similarly, in the case of backward skiing and yang,
In the previous scan direction determination block d, it is determined whether the direction is alternating with the previous scan direction.0 Here, the previous scan direction has an initial value of O'' and is stored in a storage area that is updated every time read data is generated. The previous scan direction is determined by the program by reading the status from the storage area where the previous scan direction is recorded and comparing it with the current status.

■ If it is determined that the previous scan direction and the current scan direction are the same direction, that is, if the previous status and current status are compared as described above and it is determined that the scan directions are the same, The read data is processed as valid in the read data normal processing block C. In other words, the fact that the scanning direction was the same last time and this time means that at least the scanner was not operated back and forth.

Of course, it is quite possible to rescan the same barcode in the same direction, and in order to prevent multiple readings in this case, conventional methods have been used to compare and match the previous and current scanned data. In such cases, measures are taken to invalidate the second data.

■ If it is determined that the previous scan direction and the current scan direction are alternate as a result of the status comparison, the time difference monitoring block f checks the elapsed time from the previous scan operation to the current scan operation. For time monitoring, the program uses an interval timer, and by detecting the elapsed time of the timer, the program can know the elapsed time of the barcode scanning operation.

For example, if the program reads the interval timer value during the -th scan operation and the value is y seconds, then the program reads the interval timer value during the second scan operation and the value is M. ’ seconds, the 1st and 2nd
The time difference (1) of the second scan operation is t = M'-M
(sea) is given by.

On the other hand, if the predetermined time for the scan operation time difference set in advance is T' (sea), and the elapsed time t (seC) of the two operations is t)T, then the scan direction is alternated by checking the status. However, it is determined that there is a time difference between the previous scan operation and the current scan operation based on the elapsed time t (sea), and it is determined that the operator did not unconsciously scan the same barcode back and forth.

Of course, in this case as well, it is possible to scan the same barcode alternately with a sufficient time difference, but the countermeasure against this is the same as the conventional method described above. On the other hand, 2
If the second operation elapsed time is t (T), the scan direction is alternated with the status verification, and the operator judges that there is almost no elapsed time difference between the previous scan operation and the current scan operation 1. It is determined that the same barcode was scanned back and forth unconsciously.

elapsed time t(sea) smaller than the specified time T seconds
For operational reasons, there is not enough time to replace the barcode with another barcode and perform a second scanning operation.
It is assumed that the same barcode has been scanned back and forth.

(2) If it is determined in the block f that the time is shorter than the specified time, the read data abnormality processing block q performs abnormality processing on the read data. The abnormality processing is processing such as erasing the second read data, or passing the data to the processing device with an abnormality status attached.

(2) In scan direction setting block h, a status is set in the storage area that stores the previous scan direction in preparation for the next barcode reading using the current scan direction.

Effects of the Invention The present invention has the above configuration, and the following effects can be obtained according to the present invention.

■ Equipped with a forward scan signal and a backward scan signal, as well as logic to monitor the time difference during round-trip scanning, so even if you unknowingly perform a round-trip scan operation on the same barcode, - pieces of data will not be mistakenly duplicated. ■ When scanning the same barcode back and forth, even if a temporary VC misread occurs during the forward and backward scans and the read data is different, the second data can be canceled, By reading only the first data, multiple inputs due to misreading can be prevented.

[Brief explanation of the drawing]

Figure 1 is a block diagram of a conventional barcode reader, Figure 2 is a block diagram of a conventional barcode reading device.
3 is a diagram showing an example of barcode encoding, FIG. 4 is a block diagram of a barcode reading device according to an embodiment of the present invention, and FIG. 5 is a diagram showing an example of barcode encoding. FIG. 6 is a circuit diagram showing an example of a forward and backward scan signal generation circuit of the reading device shown in FIG. 4...Interface section, 6...Signal processing section, 7...Barcode forward/backward scan signal generation circuit section, 8...Input terminal , 9...
...Encoding circuit, 1゜...Shift register, 11...--Timing generation circuit, 12.13.
... Comparison circuit, 14 ... Forward scan signal storage circuit, 15 ... Backward scan signal storage circuit, 16 ... Forward scan signal output terminal, 17...Reverse scan signal output terminal. Name of agent: Patent attorney Toshio Nakao and 1 other person 1st
Figure 2 Figure 3 Figure 5

Claims (1)

[Claims] a barcode scanner; a reading control unit that controls the barcode scanner; a circuit unit that generates a forward scan signal and a backward scan signal when scanning the barcode in the forward direction and backward direction, respectively; A barcode reading device comprising: an input/output signal control unit that monitors a time difference between a scan and the backward scan, and selectively recognizes read data obtained by each scan.