JPH11316796A - Decoding method for bar code - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce unnecessary decoding processes and to improve the processing speed by making it possible to speedily select from which code system a decoding process is performed when a bar code is read in for the 2nd time by saving a table relating to the progress and priority of a decoding process having been done for the 1st time. SOLUTION: To decode different kind of bar codes (JAN, EAN, CODE39, NW7, UPC, etc.), of different code systems, the order of decoding a signal obtained from a detecting means as a bar code is weighted on the basis of error information at the time of a 1st read of different kind of bar codes and when a 2nd read (error retrial and reread of a bar code) is made, it is decided which code system a decoding process is performed from the bar code of.

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 (bar code reader) which is used for a plurality of types of bar codes.
When reading a code, a plurality of types of bar codes (JAN, EAN, CODE39, NW) having different code systems are read.
7, UPC, etc.), the order in which the signals obtained by the detection means are decoded as barcodes is the same as when the plurality of types of barcodes are read for the first time. Weighting is performed based on the error information, and the second reading (barco-
(In the case of error retry or re-reading), it is necessary to determine which bar code of the bar code should be used for the decoding process, and to speed up the bar code reading. This is the method.

[0002]

2. Description of the Related Art Conventionally, as a type of bar code, a binary level code and a multi-level code are known. The binary level code includes a bar (thin / thick) and a space (thin / thick), and has a two-level width value. This kind of code includes CODABAR (NW-
7) 2of5, CODE93, CODE128 and the like are known. The multi-level code is a bar composed of four types of thicknesses 2, 3, and 4 times the basic width value.
Represents-. This type of code includes JAN / E
AN, UPC, CODE93, CODE128 and the like. As a method of decoding a plurality of types of bar codes, a signal obtained by a bar code reading device (bar code reader) is scanned in accordance with a bar code standard. -Toco-
Code, end code, bar code character unit, or
A threshold is calculated for each bar constituting the bar code, for the entire space, or for each section having a certain characteristic. Based on the threshold, binarization and quaternary conversion are performed to obtain a match. The code to be used is determined, and the decoding method is determined. In addition, there are a plurality of types of code systems, and when decoding an arbitrary bar code, the number of the code systems to be decoded is sequentially reduced.
Had to be performed.

[0003]

However, in the above-mentioned conventional method, in order to decode an arbitrary bar code among a plurality of code systems, decoding processing is sequentially performed for each code system. Since the coding process is performed, the order of the decoding process is slow.
Since the code is not transferred to the next barcode of the code system until the previous code system decode process fails, useless processing must be performed. It takes time to get the result. For this reason, there is a problem that the time until the result is obtained varies depending on which code system of the bar code is read first.

[0004]

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and is directed to a decoding method for decoding bar codes of a plurality of code systems consecutively. Therefore, a text for determining the order in which the decoding process is performed for each code system.
A table is provided for storing the stage at which the error occurred when an error occurred during the first decoding process of the bar code. The progress status of the decoding process is stored, and the bar code of the plurality of code systems is stored.
When the code is to be decoded for the second time, the priority order of the bar codes to be decoded is determined based on the progress of the decode processing stored at the time of the first decode processing. Barcode decoding method that determines

[0005]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Based on error information and processing progress generated in a bar code decoding process, which code system has a different code system, It is determined whether the decoding process is to be performed with priority over the bar code.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The details of the present invention will be described below with reference to the accompanying drawings. The present embodiment is particularly applied to a portable terminal device, and NW-7, C
An example in which a plurality of code systems are read for ODE39 and JAN will be described. First, a description will be given based on FIG. As shown in the drawing, the portable terminal device 1 executes the processing according to the present invention and processing such as an application program in accordance with a program stored in the ROM 3 or the RAM 4 by the CPU 2. Reference numeral 5 denotes a display device for displaying character information or graphic information supplied from the CPU 2. Reference numeral 6 denotes a key input unit serving as input means, which comprises numerical keys and various function keys (not shown). Reference numeral 7 denotes a communication unit used for exchanging data between the host computer 8 and the CPU 2. Reference numeral 9 denotes a calendar clock, which is backed up by a lithium battery (not shown) and generates date information.

Reference numeral 10 denotes a bar code reading portion. The reading portion includes a CCD, a pen type scanner, and a laser.
Although it is possible to employ a method utilizing the
It is assumed that the reading portion of the CD is used. Reference 1
Reference numeral 1 denotes a printer unit which prints out calculated data and various collected data in accordance with a command from the CPU 2. Reference numeral 12 denotes a buzzer unit that emits various warning sounds to a user (not shown) of the portable terminal device 1.

FIG. 2 shows a state in which a bar code (not shown) is read by a CCD (not shown) provided in the bar code reading section 10. As shown in the figure, the CCD signal data is converted into digital data and
It is assumed that a white portion of a code (not shown) is output at a HIGH level, and a black portion of a bar code (not shown) is output at a LOW level. The digitally converted signal is subjected to sampling processing from a LOW level to a HIGH level to a HIGH level.
Interval t1-tn for switching from H level to LOW level
Is measured and stored in the RAM 4. The values obtained here are bar and space width value data of a bar code (not shown).

FIG. 3 shows a flow of the entire processing of this embodiment. After the bar code reading is started using a bar code reader (not shown) having a plurality of code systems (S1), the above-described bar code reader is read. A signal (S2) input through a CCD (not shown) provided in the reading portion of the Dar is detected, and this signal is sampled as a digital signal (S3). In order to extract converted bar code data to be actually converted from the obtained data, detection of the leading margin of the bar code (S
4) and the end margin is detected (S5), and the decoding process is performed on the data between the two detected data (S5).
6) Output the decryption result (S7).

[0010]

[Table 1]

[0011] As shown in the above-mentioned step of the progress of the decoding process in Table 1, the progress of the decoding process of each code system is determined for each step in accordance with the standards of the respective code systems.
Set to EP6. Processes that do not exist in the standard need not be set. A step storing table for storing up to which step the decoding process has proceeded for each code system is prepared in the RAM 4, and values of 1 to 6 are stored for each progress of each step. Furthermore, in order to be aware of whether or not the data has been decoded, the decoded table (see Tables 2 and 3)
Is prepared in the RAM 4, 1 is stored if the processing is completed, 0 is stored if the processing is not completed, and 0 is stored in the initial state. When the portable terminal device 1 has just been started or when a plurality of code systems have completed processing in the same step, it is not possible to determine which code system should be given priority in performing the decoding process. A priority table is created and priorities are set in advance. In the initial state at the time of startup, all values of the table for step storage are cleared to 1 and all values of the decoded table are cleared to 0. When the bar code is read again while the portable terminal device 1 is operating, only the decoded table is cleared to 0.

[0012]

[Table 2]

[0013]

[Table 3]

Next, a description will be given of the code system sequence selection during the decoding process with reference to FIG. Decoding process is a start
(A1). First, to determine which code system should be used for decoding processing (A2), refer to the step storage table of each code system and (A3, A4). A code system having a large value and having a decoded table of 0 is selected (A5), and the decoding process is started (A6). For example, in the case of each of the table values shown in Table 3, the step value is "6", which is the maximum, and the decoded table is used.
A JAN code having a value of "0" is selected by a command from the CPU 2, and the decoding process is started.

At this time, if there is a code system having the same step value, reference is made to a preset priority table (see Table 3), and a code having a large value of the priority table is referred to. To determine the order of processing. When the decoding process is completed, the value up to the advanced step is stored in the step storing table (A7), and "1" is stored in the decoded table (A8). The process is repeated until all the values of the decoded table become 1 or the decoding process succeeds.
If all decoding is not successful (A10), the result is returned as a decoding error.

If the decoding process is successful (A9), a reference is made to the step storage table of the code system that has not been subjected to the decoding process (A11), and if the previous decoding process is successful. If so, the step value is decremented by one (A12), the priority is lowered, the result is returned, and the decoding process ends (A1).
3). When the bar code reading process is executed again,
It is possible to quickly select a code system having a high possibility of performing the decoding process quickly from the step storage table and the priority table. Although the present embodiment has been described using a case where there are three code systems (NW7, CODE39, JAN code), the number of types of codes is not limited. Further, although the number of steps indicating the processing progress is described as six steps in the progress step table of the decoding processing (see Table 1), the present invention can cope with an increase or decrease in the number of steps.

[0017]

Since the present invention has the above-described configuration, by storing a table relating to the progress and priority of the first decoding process, it is possible to perform the second burst processing.
When reading a code, it is possible to quickly select from which code system the decoding process is to be performed, and it is possible to reduce unnecessary decoding process and improve the processing speed.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a configuration of a mobile terminal device.

FIG. 2 Measurement diagram of CCD signal

Fig. 3 Flow of overall processing

FIG. 4 is a code system sequence selection diagram during a decoding process.

[Explanation of symbols]

 Reference Signs List 1 portable terminal device 2 CPU 3 ROM 4 RAM 5 display device 6 key input unit 7 communication unit 8 host computer 9 calendar, clock 10 bar code reading unit 11 printer unit 12 buzzer unit

Claims (1)

[Claims] 1. A decoding method for continuously decoding bar codes of a plurality of code systems, wherein a decoding process is performed for each code system in an order. A table is provided for the determination, and when an error occurs during the first decoding process of the bar code, an error occurs at any stage.
The progress status of the decoding process is stored in a table for storing whether or not an error has occurred, and the bar code of the plurality of code systems is stored.
When the decoding process is performed for the second time, the priority order of the barcodes for performing the decoding process is determined based on the progress status of the decoding process stored at the time of the first decoding process. A bar code decoding method characterized in that: