JPS6124746B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a data input device in an information processing system, and in particular, to a data input device for an information processing system.
The present invention relates to a device for reading code information composed of unit information patterns that are printed or attached to symbols at the same time.

In conventional barcode reading devices, if there is a defect in the black printed part of the code information, it is considered to be a white part, and if there is dirt or dust on the white part, it is considered to be a black part. However, there was a drawback that the resulting code could be replaced with another code, resulting in an error.

SUMMARY OF THE INVENTION An object of the present invention is to provide a bar code reading device which eliminates the above-mentioned drawbacks of the conventional bar code reading device and which reads bar code information using highly accurate code information.

According to the present invention, there is provided a device for reading a barcode pattern constituted by a plurality of combinations of unit information patterns formed by pairs of minute portions having mutually different tones printed or printed on a recording medium, comprising: means for verifying the location of a unit information pattern using a scanning signal obtained as a result of scanning the barcode pattern; and means for independently determining the area occupied by a specific color tone of a pair of minute portions of the unit information pattern having different color tones. Comparing the counting means and the counting results with each other,
A barcode reading device is obtained, characterized in that it includes means for storing results.

Next, embodiments of the present invention will be described in detail with reference to the drawings.

FIG. 1 shows Kanji characters and code information on a recording medium for explaining the present invention. The recording medium 1 has kanji characters 2 printed or printed thereon, and code information 3 printed or printed below the kanji characters 2. This code information 3 is composed of each unit information pattern.

FIG. 2 shows an example of a unit information pattern that constitutes code information. In FIG. 2, the unit information pattern consists of four information elements, where the unit information pattern a represents 0,0, and b represents 1,0.
A data pit can be defined such that c represents 0, 1, and d represents 1, 1.
These unit information patterns a to d are examples of two levels, an upper level and a lower level, but in this case, the information elements on the left and right sides are necessarily inverted from white to black or black to white, and both the upper level and the lower level have left or It has the characteristic that the information element on the right is either a white part or a black part. In this embodiment, a case where the unit information pattern is two stages, an upper stage and a lower stage, will be described, but the same effect can be obtained even if the unit information pattern is one stage or two or more stages.

Figures 3a and 3b show specific examples of barcode information used in the present invention, and the recording medium 1' shown in Figure 3a has code information 3' printed below the printed kanji. However, this code information 3' has a relatively thick line under the unit information pattern to clarify the scope of the code information. Further, the recording medium 1'' shown in FIG. 3B has a relatively thick line in the center of the code information 3'' to clarify the area of the code information and the upper and lower positions of the unit information pattern.

Note that additional information bits such as parity bits or correction bits can be added to the code information to increase the accuracy of the information.

FIG. 4 shows a mechanism for reading unit information patterns (unit patterns) on a recording medium. In FIG. 4, code information 3'' is printed below the printed kanji 2 on the medium. Since the code information 3'' is constructed based on the unit pattern shown in FIG.
The upper and lower stages of the unit pattern are each independently scanned from right to left as shown by arrow A by the two photoelectric conversion elements 401 and 402.

In this embodiment, two photoelectric conversion elements are used as scanning means, but a semiconductor integrated scanner or the like may be used as other scanning means.

FIG. 5 shows a read waveform, and the signal waveform obtained by the photoelectric conversion elements 401 and 402 in FIG. 4 is amplified and shaped via an amplification and shaping circuit (not shown), and the result is shown in FIG. In this example, the black part of the pattern is "1" and the white part is "0". In addition, a shown in FIG. 5 indicates the areas A ₁ to _{A 8} of the unit information pattern, and b indicates the center position t ₁ to _{t 8} of the unit information pattern. d′ shown in FIG. 5 is the photoelectric element 40.
2, especially the noise N ₁ in the shaped waveform,
The case where N ₂ is included is shown.

Next, an embodiment of the present invention will be described with reference to FIGS. 6 and 7.

Input signals are input to terminals 600, 600'. In this case, the input signal is amplified as a result of scanning the pattern, and is digitized using an arbitrary threshold value to enable the following logical processing.
They are shown in Figures c and d.

In the following description, the two photoelectric elements 40 shown in FIG.
1,402, the signal obtained from one element 401 will be explained.
It is obvious that the signal obtained from 02 can be processed in exactly the same way, so the explanation will be omitted.

The signal FIG. 5c inputted to the terminal 600 is ANDed with the output of the inverter 610 by the AND gate 601. In the initial state, as will be described later, the output of the inverter 610 is "1", so when the black portion of the character pattern is detected, the output of the AND gate 601 becomes "1". Element 602 is a monostable one-shot circuit and produces an output at the rising edge of the input waveform.

The signal input to this terminal 600 and the element 6
The output signals of 02 are shown as waveforms 600 and 602 in FIG. Hereinafter, the output waveforms of each element in FIG. 7 will correspond to the numbers shown in FIG. 6. The output of the one-shot circuit 602 passes through an OR gate circuit 603 to a monostable one-shot circuit 604.
is input. The one shot 604 is output at the falling edge of the input signal, and the pattern signal 604 is output during output.
When 0 changes from “1” to “0” or from “0” to “1”, monostable one shot 613 or 6
15 is activated, and its output is ORed by OR gate 616. That is, the one shot circuit 617 outputs only when the pattern signal 600 changes while the one shot 604 is being output, and when the one shot 604 is not outputting, the one shot 617 does not output even if the pattern signal 600 changes. This shows that even if there is a waveform change due to noise such as N ₁ and N ₂ as shown in waveform d in FIG. 5, there is a function to ignore this.

On the other hand, since the pattern signal 600 changes from "0" to "1" for the first time at the beginning of each pattern scan, the one shot 602 outputs a flip-flop consisting of gates 609 and 610, and as a result, the AND gate 601 is activated. The one shot 602 is closed and remains in that state until the end of the scan of the same pattern, and the one shot 602 therefore only outputs once at the beginning of the scan of each pattern. (corresponds to waveform 602 in Figure 7) Gate 60
When the flip-flop consisting of 9,610 is set, the next thing to be reset is the counter 60.
One shot 6 for only one character pattern by 7
Count the number of outputs of 04 and use NAND gate 608
This is when the gate changes from "1" to "0".
That is, the output of the gate 609 of the flip-flop becomes "1" during scanning of the pattern for one character, as shown in the waveform 609 of FIG. Note that when the output of the same flip-flop becomes "1", one shot 62
The oscillation circuit consisting of 1,622 operates, and the 7th
A continuous waveform shown as waveform 622 in the figure is obtained. The output of this one shot 622 is supplied as a clock pulse to the counters 643 and 645 during the black scanning period, that is, the "1" portion of the pattern signal 600. Counters 643 and 645 are set to one shot 617 by AND gates 641 and 642, respectively.
It operates separately when there is output and when there is no output. That is, if the pattern signal 600 is "1" in the section where the waveform 617 is "1" in FIG.
5 counts the number of clocks. The outputs of these counters 643 and 645 are output from the magnitude comparison circuit 64.
6 is used to compare the binary numbers, and if the value according to the bit configuration of the output of the counter 643 is larger than the value according to the bit configuration of the output of the counter 645, the input terminal J of the shift register 647 becomes "1". , K becomes "0" and is small, the input terminal J of the shift register 647 becomes "0", K becomes "1", and the output of the one shot 626, which is output at the falling edge of the output of the one shot 617, is used as a shift clock to operate the shift register. The contents of "1" and "0" are stored in and shifted. Considering these operations in a unit pattern such as a in FIG. 8, the black part in the left half of the pattern counts the output clock of the one shot 622 by the counter 645, and the black part in the right half counts the output clock of the one shot 622. In this case, when dirt or dust adhering to the paper surface is scanned as black, the counter 643 counts the clocks only in this partial section. Therefore, at the end of scanning the same pattern, the contents are compared in size and stored in the shift register 647. In this case, it is clearly detected that the black part on the left half is larger than the black part on the right half.
A similar operation is performed for each pattern unit of the pattern for one character, and the results are sequentially transferred to the shift register 6.
47 at the timing of output of one shot 626.

The reading method of this device is characterized by the above-mentioned operational functions resulting in pattern constituent units (for example, Fig. 2 a to
When reading b), the black part was missing when the same pattern was printed on the paper, and the white part was dirty.
This means that it can be read correctly unless it has the same degree of blackness as the black part due to dust or the like.

The data stored in the shift register 647 is 1
At the end of pattern processing of the character section, that is, as a result of the flip-flop consisting of gates 609 and 610 being reset, one shot 618
The gates 648, 6
49...650, 651, 652 output signals 661, 662...667, 668, 669. The circuit 681 is shown to be exactly the same circuit as the circuit portion except the encoder 680 in FIG.
This terminal amplifies the signal from 02 and inputs the digitized signal. Output signals 661', 66
2'...667', 668', 669' are output signals 6
61, 662...667, 668, 669, and are obtained by processing the input signal c input to the terminal 600' in the same manner as the input signal d input to the terminal 600.

The circuit 680 is an encoder circuit and the signal 6
61 and 661', 662 and 662'...667 and 6
67', 668 and 668', 669 and 669' form pairs, and output signals 671, 672, 673...678 are generated according to the data definition shown in FIG. , 679. Outputs 671, 672, . . . , 679 of this encoding circuit 680 are used in a data processing device to which this device is connected.

Note that the one shot 624 outputs the pattern input signal 60 with an output time that is slightly shorter than scanning the smallest white part between the patterns.
Output when 0 becomes "0".

One shot 625 is this one shot 624
If the input signal 600 of the pattern becomes "1" again while the one shot 624 is being output,
Both oneshots 24 and 625 are reset and produce no output.

That is, the one shot 625 generates an output when a white portion between characters is detected, and does not generate an output while the pattern is being scanned. The output of this one shot 625 is output to counters 607, 643, 64.
5 and for resetting the flip-flop constituted by gates 609 and 610. Note that the counters 643 and 645 are also reset at the output timing of the one shot 627 which is output at the falling edge of the output of the one shot 626.

As described above, in the present invention, the areas of the left and right black parts are counted for each unit information pattern of code information, and each time the scanning of the same unit pattern is completed, the contents of the corresponding counts on the left and right sides are compared in size and set to "1". It is designed to be able to determine "0" and can be extremely accurate. Furthermore, the present invention can read data well even on a sheet that has a large number of dotted stains, such as a sheet that has been copied using a copying machine from a data print sheet. It can also be read without any problem.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing an example of a printing pattern for explaining the present invention, FIG. 2 is a diagram showing types of unit information patterns that are constituent units of a code information pattern, and FIGS. FIG. 4 is a diagram showing a schematic mechanism for scanning a code information pattern, FIG. 5 is a diagram showing a signal waveform obtained as a result of scanning, and FIG.
7 is a diagram showing an embodiment of the present invention, FIG. 7 is a diagram showing waveforms at each part in FIG. 6, and FIG. 8 is a diagram showing an example in which the printed pattern has dirt. 1, 1', 1''... Recording medium, 2, 2', 2''...
Printed characters, 3, 3', 3''... code information pattern, 401, 402... photoelectric conversion element, 60
0,600'...Terminal, 601,612,61
4,619,641,642...and gate,
602,604,613,615,617...One shot circuit, 603,611...OR gate, 605,606,608-611...NAND gate, 607,643,645...Counter,
646... Comparison circuit, 647... Shift register, 680... Encoder.

Claims (1)

[Claims] 1. A recording medium on which code information is recorded, the minimum unit of which is a unit information pattern formed by combining at least one pair of information elements of the same width with different color tones corresponding to a binary signal, and a recording medium obtained by scanning the recording medium. means for detecting the unit information pattern from a scanning signal generated by the detection means; means for generating a dividing signal activated by the detection signal from the detecting means to divide the information element into each information element; two counting means each independently counting the scan interval occupied by the color tone corresponding to one of the binary signals in the two information elements; and a comparison means for comparing the magnitudes of the counting results of the two counting means. and one of the two information elements included in the unit information pattern is recognized as one of the binary signals, and the other of the information elements is recognized as the other of the binary signals, according to the comparison result of the comparison means. A barcode reading device characterized by: