JPS6282481A - Reading method for bar code data - Google Patents

Abstract

PURPOSE:To prevent erroneous read of a bar code by reading the number of bars and intervals of bars of the bar code and deciding whether intervals are within an allowable range of data set in accordance with the bar code or not. CONSTITUTION:A beam sensor 16 is run on the bar code marked on a work at a certain speed. A CPU 22 counts the number of bars of the bar code by a pulse signal, which is inputted when the beam sensor 16 passes on the bar code, and operates the passage time of each bar of the bar code to obtain intervals of bars of the bar code. If intervals of the bar code are within the allowable range of data set in accordance with the bar code, the number of bars of the read bar code is judged to be a correct value. The number of bars of the bar code or a product number corresponding to this number is displayed on a liquid crystal display device 32 through an interface 30 for LCD.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for reading barcode data, and more particularly, the present invention relates to a method for reading barcode data, and more specifically, a method for displaying product-related data by the number of barcodes, and arranging the barcodes at intervals corresponding to the number of barcodes. , optically read the number of barcodes and their spacing, and determine whether or not the barcode has been accurately read based on the correspondence between the number and spacing, thereby preventing misreading of the Harcode T-data. Barcode data reading method number for determining product type, shape, etc.

In recent years, many products have appeared in which data such as product price, product number, date of manufacture, etc. are marked on the product using barcodes. In this case, the barcode is usually a combination of thick black lines and thin black lines depending on the data, arranged and labeled at predetermined intervals. Therefore, barcode data is read by detecting the difference in reflectance of each barcode using an optical sensor.

On the other hand, such a method of identifying products using barcodes is extremely useful, for example, when assembling various parts in an engine. In other words, the main components of an engine include a cylinder block in which the piston is housed, a crankshaft built into the journal bearing of the cylinder block, and a connecting rod that connects the piston and crankshaft. Silk inlay, 7. , Il, ¥ko=, I? Then the hair ring is fitted. In this case, it is unavoidable that the cylinder block, crankshaft, and cleaning process will have an error of several l1m in accuracy during each machining process. In order to achieve this, it is necessary to select the optimal size hair ring for each part (A) and tie it together.

However, each worker had to perform each task of assembling these parts one by one, which required many people's time, and moreover, caused errors in assembly. There is a possibility that

Therefore, for each member fσ, 1. The optimum bearing is selected by marking the barcode on the barcode and optically reading the harness. If configured in this way, workers will not make mistakes in assembling the product X and 11, and the engine's N and 11 will be accurately and efficiently set.
l! This makes it possible to carry out additional work.

However, when a bar code is marked on such a member by printing, etc., the marked part may sometimes become unclear due to oil stains, etc., and there is a risk that accurate reading of the bar code may become impossible. .

Therefore, barcodes are engraved on the parts that make up the product, and changes in the amount of reflected light due to the markings are optically read. A method is being considered. However, depending on the precision of the engraving, the barcode may be misaligned (4), or it may be crushed (4).On the other hand, it is not easy to distinguish whether the barcode is stamped as a thick line or as a thin line, resulting in reading errors. Therefore, when barcodes are engraved, reading errors due to oil stains, etc. can be prevented, but the reading accuracy largely depends on the precision with which the barcode is engraved, so It was almost impossible to code data based on differences in quality.

The present invention has been made in order to overcome the above-mentioned disadvantages, and the present invention displays product-related data using the number of barcodes and the spacing between the barcodes corresponding to the number of barcodes, and the correspondence between the number of barcodes and the spacing. A method for reading barcode data δ that prevents misreading of barcode data by determining whether or not the barcode has been read accurately based on the relationship, and makes it possible to read 1L barcode data accurately. Capturing and supplying is considered to be ``one purpose''.

In order to achieve the above object, the present invention provides a bar code data reading method for reading data marked with a bar code, in which the bar code is arranged at predetermined intervals according to the number of bar codes. set, measure the time required from the start of reading the barcode data to read the first barcode and/or the time required to read the adjacent barcode, and calculate the time required for the bar: J-1j. It is characterized in that it is determined whether or not the number of lines has been read accurately by comparing it with a reference time set in advance according to the number of lines.

Next, preferred embodiments of the barcode data reading method according to the present invention will be described in detail with reference to the accompanying drawings.

In FIGS. 1a to 1d, reference numerals 10a to 10d indicate barcode data, and this barcode data]Oa
10d to 10d are marked by one or more barcodes 12 engraved at specific positions on the workpiece surrounded by imaginary lines A to 10d. That is, as shown in FIG. 2, this barcode 12 is a V-shaped groove carved on the surface of the workpiece 14, and four types of barcode data 10a to 10d are configured depending on the number of grooves. be done.

Further, the barcodes 12 constituting the barcode data 10a to 10d are arranged from line A toward line B at predetermined intervals P, , P2, and P according to the number of barcodes I2.

Here, in the barcode data lOa, barcode 12 is 1.
Since it is a book, the interval P2 is O.

The barcode data 10a to 10d constructed in this manner are read by a beam sensor 16 shown in FIG. In this case, the beam sensor 16 includes, for example, a light-emitting element such as a light-emitting diode, a light-receiving element such as a phototransistor, and an optical fiber (not shown) that optically connects the optical path thereof. On the other hand, the vehicle travels at a constant speed in the direction of arrow X while maintaining an inclination angle of 456. When the beam emitted from the light emitting element is reflected by the V-shaped barcode 12 engraved on the workpiece 14 and received by the light receiving element via an optical fiber (not shown), the beam sensor 16 is transmitted to the control circuit described later. A high level pulse signal is output, and when no light is received by the light receiving element, the pulse signal becomes a low level state. FIG. 2 shows the relationship between the position of the beam sensor 16 and the pulse signal in this case.

Next, the barcode data 10 configured as follows
The method of reading a to 10d will be explained based on the control circuit shown in FIG. 3 and the flowchart shown in FIG. 4.

First, the beam sensor 16 reads barcode data 10 marked on the workpiece 14 by a Cartesian coordinate robot (not shown).
Move to the position of line A from a to 10d. When the beam sensor 16 reaches line A, a high-level synchronization signal S is output from the orthogonal coordinate robot to the CPU 22 of the microcomputer 20 constituting the control circuit.
(STPI).

Upon receiving this synchronization signal S, the CPtJ22 starts counting time using an internal timer (not shown) (SrF2).

Thereafter, the CPU 22 performs control calculation operations according to a program stored in the ROM 23 in advance.

At the same time as the synchronization signal S is output, the beam sensor 6 travels at a constant speed from the line A to the line B from Oa to 10d, and when it reaches the barcode 12, as shown in FIG. , outputs a high-level pulse signal to the sensor amplifier 24. The sensor amplifier 24 amplifies the pulse signal from the beam sensor 6 and outputs the pulse signal to the CPU 22 via the sensor interface (SrF2).

On the other hand, in the CPU 22, the beam sensor 6 detects the barcode 1.
The number of barcodes 12 is counted according to the pulse signal input when passing over the barcode 2, and the passing time of each barcode 12 is calculated (SrF2.5TP5). The operations in steps 4 and 5 above are repeated until the beam sensor 16 reaches the line B of the barcode data IOa to 10d and the synchronization signal S becomes low level (SrF6). Here, the number of barcodes 112 is added by 1 according to the rise of the pulse signal input when the beam sensor 6 passes through the barcode 2.
stored in a predetermined register. In addition, as shown in Fig. 5, the barcode passage time includes the time from the rise of the synchronizing signal S to the rise of the first pulse signal, the time from the rise to the fall of each pulse signal, and the time from the rise of the last pulse signal. The time tl to t from the falling edge of the synchronizing signal S to the falling edge of the synchronizing signal S.

is calculated from the time count value of the internal timer and stored in a predetermined register. Here, FIG. 5 shows the beam sensor 16
A time chart is shown when barcode data IOd is read.

In this way, when the synchronization signal S becomes low level, C
The PU22 ends the time counting operation (SrF2).

Next, the CPLJ 22 selects a predetermined pulse width of 10 m5 ec (Fig. (see a), those below 1.0 m5ec are removed as noise as shown in Figure 6 (S TP 8). In this case, the number of barcodes counted in step 4 is subtracted by the number of pulse signals removed at step knob 8. In addition, pulse No. 13 (see Fig. 7a) with a pulse width of 10 seconds or more is removed as shown in Fig. 7, assuming that the barcode 12 is damaged due to crushing etc. (Sr.
F2). In this case as well, the number of barcodes is subtracted by the number of pulse signals removed in step 9.

After the above operations are completed, the barcode passing time is 1. to t, is the transit time T+ of the center of each pulse signal shown in FIG.
, Tzo, T21%TZ2) respectively converted to T3 (S
TPlo). In this case, for example, T1 can be determined as T, = t, −+−−−−−−. Above, T 20, 'I'' 21, T2
□ and T3 are similarly calculated. These times are stored in respective predetermined registers.

In this case, bar 21-FiffiiM time t1 to L94:l.

By converting into the time between the centers of the pulse signals, detection errors due to the engraving accuracy of the barcode 12 engraved on the workpiece 14 are averaged out, and 2) stable data can be obtained.

Next, a determination algorithm previously stored in RAM2)+ is selected according to the number of barcodes counted in step 4 (S'FP]1).

However, this judgment algorithm is based on the time TI from when the same amount signal S is output until the beam sensor 6 outputs the pulse signal, and the time TI from when the beam sensor 16 outputs the pulse signal to the next bar 2.
- Time required to read code 12 T2°, T21.
Each allowable error of 1゛2゜ (hereinafter referred to as ゛2) is set for the bar=1-1j data 10a to 10d, an example of which is shown in FIG.

In FIG. 8, the allowable time range of the time T from the output of the high-level same-quantity signal S to the detection of the first barcode 12 is shown by a white bar-shaped area. After detecting the next barcode 1
The allowable time range of the time T2 until detection of T2 is indicated by a bar-shaped region with diagonal lines. Each of the barcodes 12 by the beam sensor 16 according to this determination algorithm;
It is determined whether the m-appropriate time T and T2 are within a predetermined tolerance range (SrF12). For example, barcode 1
In the case of 4 pieces of 2, the allowable range of T is 15 from Figure 8.
It is between n+sec and 37m5ec, and the allowable range of T2 is between 49IIlsec and 104m5ec. Therefore, if both of these conditions are met at the same time, it is determined that the barcode 12 has been read accurately (5TPI3), and the number of barcodes 12 or Display the product number etc. according to the number. Also, T
, and the value of T2 is within the allowable range of the determination algorithm)
If so, it is determined that there has been an error in reading bar:1-F12 (5TP14), and a warning is displayed on the liquid crystal display 32.

On the other hand, if the barcode data] Oa to 1fld are constantly read, the data is displayed on the liquid crystal display 32 and the robot interface 3
4 through &11 (=J robot 36 is operated,
Assemble the products according to the barcode data]Oa to]Od. Zunawara, for example, Roposo l□ for assembly
A workpiece, for example, a hair ring, according to the bar data 10a to 10d is gripped by the bar 36 and assembled into a predetermined location such as a cylinder block.

According to the present invention, data regarding the product is indicated by the number of barcodes, and the barcodes are arranged at intervals corresponding to the number of barcodes, and the number and spacing of the barcodes are read. It is determined whether the interval is within an allowable range of data set in advance according to the barcode. Therefore, if the interval is within the allowable range, it can be determined that the number of barcodes read is the correct value, and if the interval is outside the allowable range, the barcode data may have missing members, etc. It can be determined that there is a failure and the barcode is not being read accurately.

As a result, it is possible to prevent misreading of barcodes marked on products and always obtain highly accurate reading results.

Although the present invention has been described with reference to preferred embodiments, the present invention is not limited to these embodiments, and various improvements and changes in design can be made without departing from the gist of the present invention. Of course.

[Brief explanation of drawings]

Figures 1a to d are explanatory diagrams of the structure of barcode data used in the barcode data reading method according to the present invention, respectively, and Figure 2 is a barcode and its detection sensor used in the barcode data reading method according to the present invention. 3 is a block diagram of a control circuit used in the barcode data reading method according to the present invention, FIG. 4 is a flowchart showing the barcode data reading method according to the present invention, and FIG. 5 is a block diagram of the control circuit used in the barcode data reading method according to the present invention. FIGS. 6a and 6b are time charts showing the relationship between the synchronization signal and the pulse signal from the beam sensor in the barcode data reading method according to the present invention, and FIGS. FIGS. 7a and 7b are time charts showing pulse signals after correction, and FIGS. FIG. 8 is an explanatory diagram showing a determination algorithm in the barcode data reading method according to the present invention. 10a~]Od...Barcode data 12...Barcode 14...Work 16...Beam sensor 20...Microcomputer]7

Claims (4)

[Claims] (1) In a barcode data reading method that reads data marked with barcodes, the barcodes are arranged at predetermined intervals depending on the number of barcodes, and from the start of reading barcode data until the first barcode is read. By measuring the time required to read the barcode and/or the time required to read an adjacent barcode, and comparing the required time with a reference time set in advance according to the number of barcodes, it is possible to accurately read the number of barcodes. A barcode data reading method characterized by determining whether or not a barcode data is read. (2) In the method according to claim 1, a synchronization signal is generated at the start of reading barcode data,
A barcode data reading method comprising measuring the time from generation of the synchronization signal to reading the first barcode. (3) In the method according to claim 1, a barcode is obtained by running an optical sensor at a constant speed, detecting a barcode based on a change in the amount of reflected light from the barcode data, and measuring the required time. How to read data. (4) In the method according to claim 1, the reference time has a predetermined tolerance range, and the barcode is determined to be good or bad depending on whether the required time is within the tolerance range. How to read data.