JPH0375887A - Bar code reading method - Google Patents

Abstract

PURPOSE:To improve reading ratio by storing a block which is read, and searching the blocks to constitute one bar code by combining the read blocks when a bar code is read from an article on which plural bar codes are printed. CONSTITUTION:Laser light sent from a laser light source 1 is reflected by a polygon mirror 3 revolved by the revolution of a motor 2 so as to scan in a random direction, and irradiates the bar code 4 printed on the article as scanning it from all angles. In the case where the bar code 4 is read from the article on which plural bar codes 4 are recorded, even if the two read blocks falls into bar code constitution failure, these blocks are not rejected but stored, and since it is investigated whether they succeed in bar code constitution together with the block read next or not, the combination of the blocks to constitute one bar code 4 is searched more quickly than in the past. Thus, the reading ration of the bar code 4 is improved.

Description

[Detailed Description of the Invention] [Summary] A barcode reading method that increases the reading rate when reading a plurality of barcodes in a hardcode reader that reads barcodes recorded on articles. A barcode reading device that projects a light beam scanned in a random direction onto an article recorded with a plurality of barcodes consisting of a plurality of blocks, and reads the plurality of barcodes using the reflected light. In this process, each time a block is detected from the barcode read by scanning the light beam, that block is stored, and after a plurality of blocks are stored, the stored blocks are interconnected. At the same time, a combination of blocks constituting one barcode is searched, and each time a combination of blocks constituting one barcode is detected, other blocks other than that block are mutually combined, The configuration is such that a search is made for combinations of blocks that constitute other barcodes.

[Industrial Field of Application] The present invention relates to a barcode reading device for reading barcodes recorded on articles, and particularly to a barcode reading method that increases the reading rate when reading a plurality of barcodes.

In recent years, in the distribution industry, etc., POS (Point of 5)
The use of barcodes, such as the Ales) system, has become popular. The barcode mainly used in the distribution industry is 8. This is the JAN code specified by JIS.

Incidentally, conventional JAN codes have been defined as 8-digit and 13-digit codes, but it has become necessary to apply them to a wider range of products, from food to clothing, records, and the like. For this reason, it has become impossible to handle this with a 13-digit barcode, so JIS has newly added multiple 13-digit codes to one product (mainly two, henceforth referred to as two-tier codes). ) trying to specify a printing method.

Therefore, it is necessary to have a barcode reading device that reads a two-stage code, and it is necessary that the reading rate when reading this two-stage code does not decrease.

[Conventional technology]

The barcode reading device used in the POS system is
Generally, what is called a stationary barcode scanner is used. This stationary barcode scanner sends out a laser beam scanned in random directions from a scanning window, and irradiates the barcode printed on the product that the operator passes through the scanning window. Then, the reflected light of the laser beam that has focused on this barcode enters the device again through the scanning window, is read by the light receiving element, is demodulated, and the code contents are decoded.

FIG. 4 is a diagram illustrating an example of the prior art.

As shown in FIG. 4(a), a conventional 13-digit bar code has delimiting symbols such as guard bars at both ends and a center bar at the center, and data is recorded between these symbols. One frame is formed between the left guard bar and the center bar, and one block is formed between the right center bar and the guard bar.

This is because the laser light emitted from the scanning window of a stationary barcode scanner randomly scans in all directions so that it can read barcodes printed on products no matter what direction they are lined up. is being sent to. Therefore, for example, from a laser beam scanning in the direction shown by the arrow ■,
This is because the barcode is often scanned at an angle with respect to the barcode, such as with a laser beam scanned in the direction of (1) or (2), and this is to provide a margin for this inclination angle.

That is, as shown in ■, it is more likely that one block of data can be read by scanning ■ and ■ than when a barcode can be read in - times of scanning, and by combining one block read respectively, one block of data can be read in one block. The structure of the barcode is carefully designed so that one barcode can be read completely.

Furthermore, consideration has been given to the structure of the scanner 1' so that reading can be completed in the same way even when scanning is performed in the opposite direction to the arrows (1) to (2). In other words, depending on the order of thick bars and thin C,
The configuration is such that it is possible to determine whether a block is on the left or the right, regardless of the scanning direction.

The one-stage code is as shown in FIG. 4(b), and the barcode shown in FIG. 4(a) is printed in two rows. In this case, scanning indicated by the arrows ■ and ■ completes the reading of each barcode, but the probability of such a situation being low is small; block A is read with the arrow ■, and block B is read with the arrow ■.
There is a high probability that the situation will be such that the block D is read with the arrow ■, and the block C is read with the arrow ■.

By the way, when a stationary barcode scanner reads two blocks, it performs a modulus check by combining the left block and right block to determine whether the blocks constitute one barcode.

If the read blocks are block A and block 13, the reading is successful because the modulus changes are matched, but if the two blocks read are, for example, block C to bronch, then , are both blocks on the left and cannot be combined.If block A and block D are combined, the modulus change cannot be matched and reading will be unsuccessful in both cases.

[Problem to be solved by the invention]

When a conventional stationary barcode scanner fails to read two blocks, it discards the two blocks as a defective barcode configuration.

Therefore, the time it takes from when two newly read blocks are determined to constitute one barcode to when it is determined that two subsequently read blocks constitute another barcode is Naturally, since it becomes longer, there is a problem that the barcode reading rate decreases.

In view of these problems, the present invention stores the read blocks and performs a modulus change on combinations of multiple blocks to find the combinations that constitute one barcode. The aim is to increase the reading rate of

[Means to solve the problem]

The present invention provides a barcode reading device that projects a light beam scanned in random directions onto an article on which a plurality of barcodes composed of a plurality of blocks are recorded, and reads the plurality of barcodes using the reflected light. In the process, each time a block is detected from the barcode read by the scanning of the light beam, the block is stored, and after a plurality of blocks are stored, the stored blocks are combined with each other. Then, the combinations of blocks constituting one barcode are searched, and each time a combination of blocks constituting one barcode is detected, other blocks other than that block are combined with each other. , to search for combinations of blocks that make up other barcodes.

[Effect]

By configuring as described above, when reading a barcode from an item on which multiple barcodes are recorded, even if the two read blocks have defective barcode configurations, this block will be stored without being discarded. , it is possible to search for a combination of blocks constituting one barcode faster than before, in order to check whether the next read block and barcode configuration are successful.

Therefore, the barcode reading rate can be improved.

〔Example〕

FIG. 1 is a block diagram of a circuit showing an embodiment of the present invention.
FIG. 2 is a diagram explaining the operation of FIG. 1.

A laser beam emitted from a laser light source 1 is reflected by a polygon mirror 3 rotated by the rotation of a motor 2 so as to scan in random directions, and scans a barcode 4 printed on an article from all angles. irradiate while

The laser beam that shines on this barcode 4 is the barcode 4.
The light is reflected from the mirror 5 and sent to the light receiving element 6 via the mirror 5. The light receiving element 6 converts the laser beam reflected from the barcode 4 into an analog electrical signal and sends it to the amplifier circuit 7.

The analog signal amplified by the amplifier circuit 7 is converted into a binarized digital signal by the A/D conversion circuit 8 and sent to the bar width counter 9. Bar width counter 9↓J Counts, for example, the width of a black bar and the width of a white bar from the pulse width of the digital signal and sends them to the demodulation circuit 10.

The demodulation circuit 10 repeats the data according to the combination of the width of the black bar and the width of the white bar, and sends the data to the processor 11.

The processor 11 operates by reading the 0 program stored in the ROM 1.2, and starts the timer 14 when notified of the start of barcode reading from a circuit (not shown). When the demodulation circuit 1o detects a guard bar and a center bar from the demodulated data, it is determined that -. blocks have been read and is stored in the RAM]3.

That is, barcodes read by laser beam scanning as indicated by the arrows [phase] shown in FIG. 2 are determined not to form a block and are discarded because the guard bar is not read.

In addition, since the center bar and guard bar of block D have been read in the barcode read with the arrow ■, block D is stored as the right block.

Similarly, the barcode read with the arrow @ is block C
Since the guard bar and center bar of block C have been read, block C is stored as the left block.

When the two blocks are stored in the RAM 13, the processor 11 performs a modulus check by aligning the blocks with thread 0, if these two blocks are the left and right blocks, respectively, to form -. barcodes. investigate.

In this example, since block C and block D constitute one barcode, the modulus check can be compared. Therefore, the processor 11 combines blocks C and D, determines that one barcode has been read, and sends it to the host device via the interface circuit 15. When the data of a specific numerical value is recorded at the beginning of the bar code L- made up of blocks C and D, the bribe processor 11 recognizes that it is a two-stage code.

Therefore, the processor 11 continues the barcode reading operation in order to detect other barcodes. That is,
Similarly to the above, the barcode read with the arrow ■ has the center bar and guard bar of block B read, so
Block B is stored as the right block.

Since the combination of blocks C and D constitutes one barcode, processor l does not determine that two blocks have been stored even if block 13 is newly stored.

Next, since the guard bar and center bar of block B are read in the barcode read at arrow 0, block B is stored as the right block.

Now that two blocks have been stored, the processor 11 attempts to perform a modulus check by combining the two blocks B, but since it is only the right block, it does not determine that it constitutes another barcode, and uses the next one. Wait for the block to be memorized.

In the arrow [phase], block A is connected to the center bar and guard bar.
has been read, so it is stored as the left block.

Here, the processor 11 combines block B and block A and performs a modulus check, and if a match is made, it is determined that another barcode has been read, and the barcode is sent to the host device via the interface circuit 15.

When the timer 14 measures and notifies the predetermined time, the processor 11 stops the reading operation even if two barcodes cannot be read because the time for reading the barcode for one product has elapsed. .

FIG. 3 is a flowchart 1 to explaining the operation of FIG. 1.

As described above, when the processor 11 is notified of the start of barcode reading, in step [phase], the processor 11 performs one scan of the laser beam.
The bar code read signal is received, and it is checked in step @ whether it is one block.

If it is not one block, the read signal is discarded in step (2) and the process returns to step [phase]. One mouth
If it is a link, use the step button to memorize this link.

Then, in step [phase], it is checked whether multiple blocks have been stored, and if multiple blocks have not been stored, the process returns to step (2). If multiple blocks have been stored, the blocks are combined with each other in step (2), and the steps described above are performed. Find out how to compose one barcode.

] 3 4 Then, in step @, it is checked whether one barcode has been detected. If one barcode is not detected, the process moves to step [phase]. If one barcode is detected, the corresponding barcode is detected in step 0. Other blocks other than the block are introduced to each other to search for combinations of blocks that constitute other barcodes.

Then, if no combination of blocks constituting another barcode is detected in step [phase], step [phase] is detected.
When a combination of blocks constituting another barcode is detected, it is checked in step ■ whether or not it has ended. If not, it moves to step O, and if it is, the bar code is End the code reading operation.

[Effects of the Invention] As explained above, the present invention stores the read blocks when reading a barcode from an article on which a plurality of barcodes are printed, and combines them to form one barcode. Since the constituent blocks are searched, the reading rate can be increased.

[Brief explanation of drawings]

FIG. 1 is a block diagram of a circuit showing an embodiment of the present invention, FIG. 2 is a diagram explaining the operation of FIG. 1, and FIG. The figure is a diagram illustrating an example of a conventional technique. In the figure, 1 is a laser light source, 2 is a motor, 3 is a polygon mirror, 4 is a barcode, 5 is a ξ roller,
6 is a light receiving element, 7 is an amplifier circuit, 8 is A
/D conversion circuit, 9 is a bar width counter, 10 is a demodulation circuit,
11 is a processor, 12 is a ROM, 13 is a RAM,
14 is a timer, and 15 is an interface circuit. Figure 26 to explain the operation of Figure 1.

Claims (1)

[Scope of Claims] A barcode in which a light beam scanned in a random direction is projected onto an article on which a plurality of barcodes composed of a plurality of blocks are recorded, and the plurality of barcodes are read by the reflected light. In the processing of the reading device, each time a block is detected from the barcode read by the scanning of the light beam, the block is stored, and after a plurality of blocks are stored, the stored blocks are mutually When a combination of blocks forming one barcode is detected, other blocks other than that block are combined with each other. A barcode reading method characterized in that a combination of blocks constituting another barcode is searched.