JPS58161078A - Recognizing device of bar code character - Google Patents

Abstract

PURPOSE:To reduce the read error, by detecting the width of a bar of the width between bars by the output of an image sensor. CONSTITUTION:Bars 15 and 17 constituting a bar code character or a part 16 between bars is focused onto a one-dimensional image sensor 5, and the number of elements indicating the same polarity continuously is taken into a computer in the order of the arrangement of elements 180-18-15. This 16-bit information is processed by the computer to recognize the bar code character. Consequently, the read error is reduced independently of the change of the character scanning speed.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a barcode character recognition device for reading barcode characters.

Conventional barcode character recognition devices analyze the waveform scanning a character for time and amplitude to determine the presence or absence of bars or strokes and measure the spacing between strokes. Such systems were relatively complex or slow to operate and required relatively complex circuitry. Furthermore, if the scanning speed of the characters changed significantly while scanning the characters, it was impossible to read them.

SUMMARY OF THE INVENTION An object of the present invention is to provide a code character recognition device that has a simple circuit configuration and does not depend on the character scanning speed.

That is, the present invention causes a -dimensional image sensor to image the bars or between bars that constitute a barcode character,
This is a barcode character recognition device that recognizes barcode characters by detecting the width of these elements by the number of elements that successively exhibit the same polarity and sequentially detecting them as the characters are scanned.

The present invention will be described in detail below along with examples.

FIG. 1 shows an embodiment of the optical system of the apparatus according to the invention. The bar 1 and the image 2 of the bar 1 are thickened for convenience. A bar 1 on a medium 3 on which a bar code is printed forms an image 2 of the bar 1 on a one-dimensional image sensor 6 via a lens 4. At this time, it must be possible for the image 2 of the bar 1 to be entirely mapped inside the one-dimensional image sensor 6. The same applies to the image between bars 1. Therefore, when reading a TAN code with standard module dimensions using a one-dimensional image sensor with 16 elements spaced at 60μ intervals, the maximum bar width or maximum inter-bar width is 1
．． 4-weak, so the distance between the lens 4, the code medium 3, and the distance between the lens 4 and the image sensor 6 are set so as to form an image with a width of approximately % or less of the width. There is a need to.

If the width of the image 2 of the bar 1 is too small relative to the width of the bar 1, the number of elements assigned to the sensor 6 that detects the minimum bar width will decrease, resulting in a decrease in the accuracy of barcode character reading.
The scale of the image is optimal. In addition, in the figure, 6
-1 to 6-4 are auxiliary lines for drawing the image, and 7 is the focal point of the lens 4.

FIG. 2 shows an embodiment of a circuit for importing barcode character information into a system including a microcomputer. In the figure, Do"'-D15 indicates the data bus of the microcomputer, IOW indicates a write signal to the flip-flop 8 which is an output device as seen from the microcomputer, and 5YNC indicates one round sweep of each element of the one-dimensional image sensor. CLK indicates the pulse that sends out the output of the sensor, DATA indicates the amplified and shaped output of each element that makes up the sensor,
xon is a read signal of the 3-state buffer 12, which is an input device from the perspective of the microcomputer. First of all.

When set to 1 and output to flip-flop 8, signal line 1
3 becomes 1, and then the signal line 14, which is the output of the flip-flop 9, becomes 1 due to the 5YNC signal, the 3-state buffer 1o opens, and CLK becomes the serial input 1.
DATA to 6-pit parallel output register 11
Send out. Next, when Do is set to 0 and the flip-flop 8 is set, the signal l513 becomes O, and then the signal line 14 is set to 0 by the 5YNC signal, and the 3-state buffer 1o
is closed, and the new ATA input to the register 11 is stopped. As mentioned above, the input to the register 11 is stopped at 5
Since it is synchronized with YNC, the information in the register 11 is stored in the order in which the sensor elements are arranged. Details of the above timing are shown in FIG.

Next, when the three-state buffer 12, which is an input device, is read, information on each element of the sensor is taken in in the order in which the elements are arranged.

This 16-bit information is processed by a microcomputer. The above cycle is repeated to recognize barcode characters.

Next, processing within the microcomputer will be explained.

FIG. 4 shows each element 18 of the one-dimensional image sensor of the embodiment.
-O to f8-j5, bar images 15 and 17, and an image 16 between the bars.

FIG. 5 shows the output of each element over time when it is incorporated into a microcomputer, with O marks corresponding to the bars and X marks corresponding to the spaces between the bars. When it comes to an intermediate position like elements 18-13 in Fig. 4, it is not clear whether it is 1 or 0, but
In the state in which the microphone combination was introduced overnight, it is in one of the states, and as a result, the number of elements indicating each bar or between each bar at each time is not constant.

How to process the data shown in FIG. 6 will be explained below using an example. First, in T1, Bit Otori 16
is detecting the ○ mark, that is, the bar, so the beep [6 to 1
Count and store the number of bits that indicate the distance between bars up to 2.

At this time, consecutive bits 2 to 6 marked with O can also be counted, but since they can be counted after T7, they are not counted here. Similarly, bit melon 15 is T2 marked with ○.
゜T, etc. are also counted, and bit cups 6 to 12 in T.
Calculate and store the average between the bars up to. Pip 1 in T7
Since 415 is an x mark, the number of bits indicating the bar from bits 4 to 7 is counted, and the same process is sequentially performed thereafter. The above processing starts when a 0 mark appears in bit 415 and ends when all bits become x marks. The above flowchart is shown in FIG.

When this series of processing is completed, the widths of all bars of the barcode character other than the width of the first bar and the width between all bars are obtained as the average value of the number of elements representing each width. Barcode characters can be expressed in binary numbers based on the average value of the number of elements representing heat doper, and barcode characters can be recognized.

The present invention detects the bar width or the width between bars using the output of an image sensor that usually finishes one sweep after several tens of μ east, so it does not depend on changes in character scanning speed and requires almost no data processing. can be done within a microcomputer,
Therefore, if you use a microconbeater that does not require complicated circuits and has a high processing speed, there will be more opportunities to detect the width of a single bar or the width between bars, reducing misreading, which will have a large effect. It is something.

[Brief explanation of drawings]

Fig. 1 is a layout diagram of an optical system for implementing a barcode character recognition device according to the present invention, Fig. 2 is a block diagram of a circuit for importing barcode character information into the system, and Fig. 3 is a timing diagram. Chart, Figure 4 is a diagram showing images of the sensor and Nokuichi code characters in the embodiment of the present invention, Figure 6
The figure also shows data values for each time, and FIG. 6 is a flowchart for importing barcode/character information into the system in an actual example of the present invention. 1...bar, 2,1 5. 1 7...
・・・ ノ (- image, 3... Media on which the barcode is printed, 4... Lens, 6... -
Dimensional image sensor, j, 9...-free lag flop, 10, 12...3 stereo (sofa, 1
1... Serial input 16-bit output register, 13, 14... Signal line, 16... Image between bars, 18-0 to 1f3-
15...Elements constituting a -dimensional image sensor. Name of agent: Patent attorney Toshio Nakao and 1 other person $1
481 1I5!1 Biz)-N. 19867-June Patent Office Commissioner 1 Indication of the case 1986 Patent Application No. 44334 2 Name of the invention Barcode character recognition device Representative Toshihiko Yamashita 6 Details of the invention in the specification subject to amendment Explanation column 3, page 4, line 18 of the statement of contents of the amendment, change “to 8” to “IO to 8”
When the W signal is output, it will be corrected to ''°.

Claims (1)

[Claims] A one-dimensional image sensor and the image of the widest bar that makes up the entire barcode character or the image between the widest bars are
an optical system that forms an image inside a line segment connecting each element constituting the dimensional image sensor; a detection circuit that detects the number of the elements showing the same polarity corresponding to the image; Barcode character recognition comprising means for sequentially reading the data of the detection circuit and detecting the number of the elements corresponding to the images of all the bars constituting the barcode character and the images between all the bars and reading the information of the barcode character. Device.