JPH09259216A - Bar code reader - Google Patents

Abstract

PROBLEM TO BE SOLVED: To distinguish whether the same bar code label is repeatedly read or the different bar code label is read. SOLUTION: An article detection part 6 sends article detection signals 105 to a decoding part 7. An article address generation part 5 counts article clocks after the rise of the article detection signals 105, generates an article address 104 and sends it to the decoding part 7. The article address 104 indicates a position on an article 14 and the decoding part 7 decodes a bar code. Further, from the position on the article address 104 where the bar code is detected, the sticking position of the bar code label on the article 14 is recognized.

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 articles conveyed by a belt conveyor.

[0002]

2. Description of the Related Art In recent years, most distribution products have a bar code label on which a bar code such as a product name or a delivery address is attached for management purposes, which is attached to the surface of an exterior (corrugated cardboard) and conveyed by, for example, a belt conveyor. Then, the barcode read by the barcode reader is read to perform, for example, confirmation of the product or distribution control for each delivery destination of the product.

The reading of a bar code is carried out from a semiconductor light emitting device such as a laser diode or a light emitting diode.
A bar attached with infrared light or visible light laser light or light equivalent thereto (hereinafter referred to as a laser beam) at a sweep (scanning) speed sufficiently higher than the conveyance speed of the article, for example, by a rotating polygon mirror or the like. The code is swept (scanned) and the reflected light from the bar code is detected to read the bar code.

It is difficult to accurately control the position where the bar code label is attached to the article. Therefore, the sweeping (scanning) of the laser beam for reading the barcode is in a fairly wide range. For example, as shown in FIG. 2, when an article 14 is conveyed on a belt conveyor in the direction of arrow A, the plurality of laser scanning beams 11 and 12 are arranged, for example, in a crossed manner as shown. Note that the laser scanning beam may be arranged in various manners such as arranging two or more laser scanning beams in parallel, in addition to the illustrated method.

In the case of the positional relationship between the bar code 13 and the laser scanning beams 11 and 12 as shown in FIG.
Although the bar code 13 can be read only by the laser scanning beam 12, the bar code 13 is read by the laser scanning beam 1 when the article 14 is transported and the positional relationship shown in FIG.
1 and 12 will be read. Further, since the sweeping (scanning) speed of the laser beam is sufficiently higher than the conveying speed of the article 14, the same bar code 13 may be read by the laser scanning beam 11 or 12 multiple times.

[0006] For example, in the case of bar code reading of a product in a supermarket, it is necessary to confirm that the bar code label is attached to the product and manually carried to the bar code reading device to read the bar code. It is also easy, and even if the barcode cannot be read well, it can be easily read again.

Therefore, as described in JP-A-4-297969, when the same bar code (having a code content) is continuously read, the same bar code label is repeatedly read. As a result, so-called double reading can be prevented by discarding the second (same) read data onward.

[0008]

When an article is conveyed by a belt conveyor, it is disclosed in Japanese Patent Laid-Open No. 4-29796.
Unlike the case described in the publication No. 9, there is a possibility that articles having the same code content will be continuously sent, and whether the same bar code label has been read twice. It may not be possible to distinguish whether different barcode labels were read.

An object of the present invention is to provide a bar code reading apparatus capable of distinguishing whether the same bar code label is read twice or different bar code labels are read.

[0010]

According to the present invention, there is provided a bar code reading apparatus for a bar code label attached to an article at the time of article conveyance by a belt conveyor, including bar code reading means for reading a bar code and conveyance on a belt conveyor. An article detecting means for detecting the article to be detected at one point, and an article determining means for determining that one article has been conveyed in a period from the start of detecting the article by the article detecting means to the interruption of the detection of the article. An article counting means for counting the number of conveyed articles determined by the article determining means, and a position of the barcode read by the barcode reading means on the one article determined by the article determining means On the one article judged by the article judging means by the article addressing means and the article addressing means,
When a plurality of barcodes are read by the barcode reading means, it is distinguished whether the same barcode is read redundantly or different barcodes are present, and the barcode is duplicated or duplicated. It is characterized by including a barcode number determining means for counting the number of barcodes that have passed, excluding the number of barcodes that have been read.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The operation of the present invention is as follows.
By detecting the sticking position (article address) of the bar code label on the article using the article detection signal, whether the same bar code (label) has been read twice or more, or different barcodes can be read. Code (label)
Distinguish whether was read.

An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram showing the construction of an embodiment of a bar code reading apparatus according to the present invention, and FIG. 2 is a view for explaining the positional relationship between an article to be conveyed and a laser scanning beam. In addition, the duplicated description of FIG. 2 is omitted.

The scanning unit 1 shown in FIG. 1 generates laser (scanning) beams 11 and 12 (see FIG. 2), sweeps a bar code (label) 13, and outputs a counter reset signal 106 corresponding to the sweep start timing. It is sent to the digital signal analysis unit 4. The laser beam reflected from the barcode label is detected by the light receiving section 2, shaped into a pulse signal by the A / D conversion section 3, and sent to the digital signal analysis section 4.

The digital signal analysis unit 4 generates a clock signal for reading a bar code based on the counter reset signal 106, counts this clock signal from the generation timing of the counter reset signal 106, and generates a bar code detection address 103. Bar width data of barcode 1
01 and the space width data 102 are sent to the decoding unit 7.

The article detection unit 6 is, for example, the belt conveyor 1
A laser beam 6-3 generation part 6-1 and a light receiving part 6-2 are provided on both sides of 5, and the product 14 is shielded from the detection parts. Therefore, conversely, by shading the article 1
4 is detected to be conveyed, and it is determined that one article 14 is continuously conveyed until the light shielding is released. The article detection signal 105 corresponding to this light-shielding period is sent to the decoding unit 7.

The article address generation unit 5 uses the article detection signal 1
The product clock is counted from the rising edge of 05 (the moment when the tip of the product 14 reaches the detection point of the product detection unit 6) to generate the product address 104, which is sent to the decoding unit 7. The article clock is supplied from a programmable timer set by switch 7-4 such that its period is inversely proportional to the transport speed of article 14. Therefore, the item address 104 indicates a position on the item 14.

The decoding unit 7 is a CPU (computer element) 7
-1 and RAM (random access memory) 7-3, bar width data 101, space width data 10
2. Decode (read) the barcode based on the barcode detection address 103. Further, the laser scanning beam 11
The address difference on the article address 104 between the attachment positions of the and 12 and the detection point of the article detection unit 6 is stored in advance in the ROM.
Since it is stored in the (read only memory) 7-2, it is possible to recognize the sticking position of the bar code label on the article 14 from the position on the article address 104 where the bar code 13 is detected.

Therefore, when a plurality of bar code labels are detected in the range determined to be one article 14 by the article detection signal 105, the same bar code label is duplicated twice or more (double). It is possible to distinguish whether it was read by the user or there were two or more barcode labels.

When the articles 14 are conveyed very close to each other, the article detection section 6 cannot distinguish and detect them, and may detect them as one article 14. In this case, when two or more bar code labels having different contents (type, number of digits, data contents, etc.) are confirmed, it is determined that there are as many articles 14 as the confirmed bar code labels.

However, the exact same contents (type, number of digits,
If two or more barcode labels (for data contents etc.) are confirmed within the range determined to be one article 14, it is tentatively recognized that there are as many articles 14 as the number of barcode labels. Above (switch 7-4 in advance
If the barcode labels having the same content (which can be set in step 1) are confirmed within the range determined as one article 14, an abnormality (for example, two or more barcode labels are put on one article 14 etc.) ) And output the transport control error data.

A method for detecting the position of the bar code on the article 14 will be described with reference to FIG. In FIG. 4, when two articles 14 happen to come into contact and are conveyed, the article detection signal 105
Stands up when the first article 14 reaches the detection point (laser beam) 6-3, and the second article 14 is detected at the detection point 6-3.
It falls when it passes -3. At the same time, the article address 104 starts when the article detection signal 105 rises, and stops when the article detection signal 105 falls.

The laser scanning beams 11 and 12 read the bar code 13, respectively. Since the bar code 13 is read sufficiently faster than the transportation of the article 14 as described above, the article address 104 shown in FIG. The length of the read detection bar code is sufficiently shorter than the length of the bar code 13 on the reference diagram (of the axis).

From the fall of the detection bar code, the article 1
4. A bar code gate signal having a width corresponding to the length of the bar code 13 above (the bar codes read during this period are all judged to be the same bar code 13).
When c is generated, the second and subsequent detection barcodes within this period are all gated out (rejected), and a gated barcode d is generated.

The second article 1 conveyed in contact with two pieces
It can be seen that the detection bar code read from the bar code 13 on No. 4 is read at a position clearly different on the article address 104 from the bar code 13 on the first article 14.

The output process of the bar code reader is shown in flow chart form in FIG. In FIG. 3, when the reading is executed while recording the barcode detection position and the detection time (step 20), first the read data (from the article 14) is output to the output buffer, and the read data count (conveyed article is carried out). It is stored together with # 1 (corresponding to the number of 14) (step 21).

Next, it is judged whether or not there is another read (bar code) data on the same article 14 as this (step 22). If there is no read data (bar code) data, the read data and the read data count (the number of articles 14 conveyed are counted). Check the (corresponding) number and output the data from the output buffer (step 2
6) Yes.

If there is other read data on the same article 14 (step 22), the type of read data, the number of digits,
Determine if the data (contents) are the same (Step 2
3) If the same, further detection position (article address 104
Above), it is judged whether the detection times are the same (step 24),
If they are the same, the same bar code (label) 13 is rejected as being read twice, and the process returns to step 22.

If the type, the number of digits, the data (content), etc. of the read data are different (step 23) or the detection position, the detection time, etc. are different (step 24), the read data is stored in the output buffer and read. The data count (corresponding to 14 conveyed articles) is incremented (step 25) and proceeds to step 26, while returning to step 22 to process the read data on the next article 14.

[0030]

As described above, according to the present invention, when a plurality of bar codes having the same content are read from a range determined as one article, the same bar code label is read in duplicate. It is possible to distinguish whether the barcode data is read or a different barcode label is read, and it is possible to prevent the trouble that the number of read data of the barcode does not match the number of articles.

[Brief description of drawings]

FIG. 1 is a block diagram of an embodiment of the present invention.

FIG. 2 is a diagram illustrating a barcode reading method.

FIG. 3 is a flowchart illustrating the operation of the embodiment of the present invention.

FIG. 4 is a diagram illustrating an address on an article.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Scanning part 2 and 6-2 Light receiving part 3 A / D conversion part 4 Digital signal analysis part 5 Product address generation part 6 Product detection part 6-1 Generation part 6-3 Laser beam 7 Decoding part 7-1 CPU 7-2 ROM 7-3 RAM 7-4 Switch 13 Bar code 14 Article 15 Belt conveyor 101 Bar width data 102 Space width data 103 Bar code detection address 104 Article address 105 Article detection signal 106 Counter reset signal

Claims (4)

[Claims] 1. A bar code reading device for a bar code label affixed to an article when the article is conveyed by a belt conveyor, wherein bar code reading means for reading the bar code and one point of the article conveyed on the belt conveyor. An article detecting means for detecting the article, an article determining means for determining that one article has been conveyed during a period from when the article detecting means starts detecting the article to when the detection of the article is interrupted, and the article determining means Article counting means for counting the number of conveyed articles determined by, and article addressing means for specifying the position of the barcode read by the barcode reading means on the one article determined by the article determining means. , A plurality of articles by the barcode reading means on the one article determined by the article determining means by the article addressing means. If one bar code is read, distinguish between whether the same bar code was read redundantly or different bar codes exist, and the number of double or more duplicated bar codes that were read. And a bar code number determining means for counting the number of bar codes that have passed. 2. The article detecting means comprises a laser beam emitting section and a laser beam receiving section arranged on both sides of the belt conveyor, and detects the presence of the article by shielding the laser beam by the article. The bar code reader according to claim 1, which is characterized in that 3. An article transportation number certifying means for certifying that the article has been transported by the number of barcodes determined by the barcode number determining means regardless of the number of articles counted by the article counting means. The bar code reader according to claim 1 or 2, which is characterized in that. 4. A means for outputting conveyance control error data when a plurality of barcodes are read by the barcode reading means on the one article determined by the article determining means. The bar code reading device according to claim 1, 2 or 3, wherein.