JPH04222079A - Bar code reader - Google Patents

Abstract

PURPOSE:To read out a bar code even when an intersecting angle between the bar code and a scanning line is large. CONSTITUTION:This bar code reader includes a digital signal analyzing part 4 provided with an angle counter 4a and a scanning frequency counter 4b and a decoding part 5, and at the time of reading out a bar code in a large intersecting angle state between the bar code and a scanning line, a pulse width data string is two-dimensionally addressed based upon the outputs of both the counters 4a, 4b and stored in the analyzing part 4 and the stored pulse width data string is reconstituted to a complete pulse width data string from the start character up to the stop character and decoded by the decoding part 5 based upon the count values of the counters 4a, 4b.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a barcode reading device, and more particularly to a barcode reading device that uses a split reading method in reading barcodes.

0002

2. Description of the Related Art A barcode reading device reads a barcode label on an article by irradiating a laser beam onto the barcode label and receiving the reflected light. Here, in the conventional barcode reading device, as shown in FIG.
5, the reflected light 16 is received by the light receiving section 11, and the analog signal output from the light receiving section 11 is sent to the A/D converting section 12.
By converting it into a digital signal and measuring the pulse width of the digital signal, the digital signal analysis section 13 extracts the pulse width data string only when scanning the surface of the barcode, and upon receiving the result, the decoding section 14 decodes it. conduct.

Generally, barcode reading devices read barcodes by scanning the barcode label as shown by scanning line 20 in FIG. In other words, note that the entire range surrounded by the start character 22 indicating the start of the barcode and the stop character 23 indicating the end is a barcode, and the start character 22
Only the electrical signals obtained from the scanning line 20 scanned at one time from to the stop character 23 were decoded. Therefore, the scanning line 21 having an intersecting angle of 24 with respect to the bar code cannot be read because it does not include a start character and a stop character at the same time.

0004

[Problems to be Solved by the Invention] In the barcode reading device according to the prior art described above, since reading can only be performed with a scanning line that passes through the start character and stop character at once, the intersection angle 24 between the barcode label and the scanning line is If it becomes too large, it becomes impossible to pass through the start character and stop character at once, making it impossible to read the barcode label, which has the disadvantage that the intersection angle between the barcode label and the scanning line cannot be made large.

SUMMARY OF THE INVENTION An object of the present invention is to provide a barcode reading device that can read a barcode even if the angle of intersection between the barcode and the scanning line becomes large.

[0006]

[Means for Solving the Problems] In order to achieve the above object, a barcode reading device according to the present invention includes a scanning section that outputs a scanning beam that scans a barcode label on an article;
A light receiving section that receives reflected light from a barcode label and converts it into an electrical signal, an A/D conversion section that converts an analog signal from the light receiving section into a digital signal, a digital signal analysis section that analyzes the digital signal, and a digital signal analysis section that analyzes the digital signal. The digital signal analysis section includes a decoding section that receives the pulse width data string outputted by the signal analysis section and decodes the barcode, and the digital signal analysis section has a counter that indicates the scanning angle of the scanning beam and a counter that indicates the number of times the scanning beam is scanned. It has a function of performing two-dimensional addressing and storing a pulse width data string obtained by scanning a barcode label based on the outputs of both counters.

Further, the decoding section regenerates the pulse width data string outputted from the digital signal analysis section into complete pulse width data by using the angle counter value and the scanning counter value, and decodes the pulse width data. .

Further, the angle counter is cleared immediately before the scanning beam is irradiated to the outside from the bar code reading device, and is counted up every time a certain period of time elapses, and the scanning times counter is cleared by the angle counter. It is counted up at the timing when is cleared.

[0009]

[Operation] When a barcode label is scanned at a crossing angle, the pulse width data string is two-dimensionally assigned and output, thereby regenerating it into a complete pulse width data string from the start character to the stop character. Perform deciphering.

0010

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a diagram showing an embodiment of the present invention. In the figure, the barcode reading device of the present invention includes a scanning section 1 that outputs a scanning beam that scans a barcode label on an article;
A light receiving section 2 that receives reflected light from a barcode label and converts it into an electrical signal, an A/D converting section 3 that converts an analog signal from the light receiving section into a digital signal, and a digital signal analysis section 4 that analyzes the digital signal. and a decoder 5 that receives the pulse width data string outputted from the digital signal analyzer 4 and decodes the barcode, and the digital signal analyzer 5 includes a counter 4a that indicates the scanning angle of the scanning beam, and A counter 4b indicating the number of scans is provided.

As shown in FIG. 2, the angle counter 4a is
The scanning beam 7 is cleared immediately before it is irradiated to the outside through the scanning window 6 of the barcode reader, and is counted up every time a certain period of time elapses. Further, the scanning counter 4b is a free running counter that is counted up at the timing when the angle counter is cleared. The angle counter 4a has 5 bits, and the scanning counter 4b has 3 bits. In other words, the angle counter 4a is
As shown in FIG. 2, the light is irradiated to the outside through the scanning window 6, and as the scanning angle 8 increases, it increases as 0, 1, 2, 3, . . . . If it is a 5-bit counter, it will count up to 31, but the moment it is incremented by 1 from 31 and reaches 0, the scanning beam will enter the inside of the device again. The scanning counter 4b is a free running counter,
If it is 3 bits, it will be incremented by 1 each time the scanning beam exits the device from the scanning window, so 0, 1, 2, ..., 6, 7, 0
, 1, 2, etc.

[0012] Now, let us consider a case where a moving barcode label is scanned by the scanning unit 1. If the scanning line is fixed and the barcode label moves at a constant speed, it will be scanned as shown in FIG. Among scanning lines 30 to 44, scanning line 3
4 to scanning line 41, since the barcode label is scanned, the digital signal analysis unit 4 collects pulse width data corresponding to the white/black bars of the barcode label while scanning the barcode label. Remember columns. At this time,
When the digital signal analysis section 4 stores the pulse width data string, it also stores the angle counter value 50 and the scan times counter value 60 at the same time. As a result, a two-dimensional address is assigned to the pulse width data string obtained by scanning the barcode label using the angle counter and the scanning counter.

Next, the decoding unit 5 converts the pulse width data string obtained by scanning the scanning line 34 to the scanning line 41 into a start character 70 to a stop character by using the angle counter value and the scanning counter value. The data is regenerated into complete pulse width data up to 71 and decoded. This is called split reading. When scanning the surface on which the barcode label is attached, generally the scanning counter 50 in FIG. 5 is 1 to 4, and the angle counter 60 is 10 to 15.
Because there are characters such as "Underwriting Office Receipt" and other pictures existing in the position of , it may be mistaken for scanning the barcode, so to remove them, angle counter 4a
is used. That is, the angle counter values of the pulse width data obtained by scanning the barcode label shown in FIG. 5 are from 19 to 26, and the angle counter values of the "underwriting station copy" are from 10 to 15. Since it can be determined that they are spatially separate, there is no possibility of erroneously composing the two. Therefore, by using the angle counter 4a, it is possible to extract only the pulse width data obtained when actually scanning the barcode. Furthermore, since the decoding unit 5 can determine the two-dimensional position of the pulse width data string broken into small pieces by the scanning counter 4b and the angle counter 4a, it is possible to regenerate complete pulse width data from the start character to the stop character. , it becomes possible to decipher. That is, as shown in FIG. 5, the barcode label can be read even when the intersection angle between the barcode label and the scanning line is large and the scanning line does not pass through the start character and stop character at the same time.

[0014]

[Effects of the Invention] As explained above, according to the present invention, the intersection angle between the scanning line and the barcode label is increased, and there is no longer a scanning line that passes from the start character to the stop character at once, resulting in discrete scanning. However, pulse width data corresponding to white/black bars can be obtained only when scanning a barcode label. As a result, complete pulse width data including a start character and a stop character can be regenerated and decoded from the booth break data, making it possible to realize a high-performance barcode reading device.

[Brief explanation of the drawing]

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

FIG. 2 is a diagram showing the operation of an angle counter.

FIG. 3 is a block diagram showing a barcode reading device according to the prior art.

FIG. 4 is a diagram showing a scan sequence of a barcode label.

FIG. 5 is a diagram showing a scan sequence of a barcode label.

[Explanation of symbols]

1 Scanning section 2 Light receiving part 3 A/D conversion section 4 Digital signal analysis section 4a　Angle counter 4b Scanning counter 5 Decoding part

Claims (3)

[Claims] 1. A scanning unit that outputs a scanning beam that scans a barcode label on an article, a light receiving unit that receives reflected light from the barcode label and converts it into an electrical signal, and a digital signal that converts the analog signal from the light receiving unit into a digital signal. It has an A/D conversion section that converts the digital signal into a signal, a digital signal analysis section that analyzes the digital signal, and a decoding section that receives the pulse width data string output from the digital signal analysis section and decodes the barcode. The signal analysis unit includes a counter that indicates the scanning angle of the scanning beam and a counter that indicates the scanning number of the scanning beam, and based on the outputs of both counters, it calculates a pulse width data string obtained by scanning the barcode label. A barcode reading device having a function of performing and storing two-dimensional addressing. 2. The decoding unit regenerates the pulse width data string output by the digital signal analysis unit into complete pulse width data by using an angle counter value and a scanning counter value, and decodes the pulse width data. Claim 1 characterized in that
The barcode reading device described in . 3. The angle counter is cleared immediately before the scanning beam is externally irradiated from the barcode reading device, and is counted up every time a certain period of time elapses, and the scanning times counter is an angle counter. 2. The barcode reading device according to claim 1, wherein the barcode reading device is incremented at the timing when the barcode reading device is cleared.