JPS6035707B2 - information reading device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an information reading device for reading product information etc. constituted by barcode marks.

In recent years, in the distribution industry such as department stores that handle a large variety of products, in order to efficiently manage product sales, for example, P
Devices such as OS (Point of Sales) terminals have been developed and put into practical use. The above-mentioned POS terminal employs a method in which a bar code indicating the type of product is printed on a label and pasted on the product, and the product code is read by a barcode reading device at the point of sale.

However, in the conventional barcode storage device, Fig. 1a
As shown in FIG. 2, when a label 2 on which a barcode is printed is attached to a product 3, a shadow 4 of the label is generated, and this shadow 4 may be mistakenly read as a regular barcode.
Furthermore, if the material of the hubel 2 is thin as shown in Figure 1b, there is a risk that, for example, a black bar-shaped pattern 5 drawn on the product may be mistakenly read as a regular barcode, as described above. there were. This invention has been made in view of the above points, and enables reliable information reading by distinguishing unnecessary noise caused by shadows, etc. in front of legitimate information in product information composed of barcodes, etc., making it extremely easy to read. The purpose of this invention is to provide an information reading device with excellent performance.

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

In FIG. 2, 1 is a bar code, 12 is a hand scanner that incorporates a light emitter, a light receiver, and a photoelectric conversion element.The read signal from this hand scanner 12 is amplified by an amplifier 13, and then a capacitor C, a resistor R, The signal is supplied to a differentiating circuit 14 made up of a capacitor C2 and a resistor R2 via an inverter 15. The differentiated output of the differentiating circuit 14 is supplied to the first input terminals of an OR circuit 17 and an AND circuit 18, respectively. The differential output of the differential circuit 16 is supplied to the set terminal S of the flip-flop 19, and is supplied to the second input terminal of the OR circuit 17, as well as to the clock terminal CP of the shift register 20 that stores the width of the barcode 1. be done.

The differentiating circuit 14 is for differentiating the rising edge of the read signal from the hand scanner 12, and the differentiating circuit 16 is for differentiating the falling edge of the read signal. Further, the decoder 23 does not output an output when the count number of the counter 22 is less than a predetermined value, and outputs an output when the count number exceeds a predetermined value. The set output terminal Q of the flip-flop 19 is connected to one input terminal of the AND circuit 21. Clock pulses are continuously supplied to the other input terminal of this AND circuit 21, and its output terminal outputs the width of the black signal (barcode signal) and the width of the adjacent black signal (
It is connected to a clock input terminal CP of a counter 22 that counts the width of the white area between the barcode signals and converts it into time. The output terminal of this counter 22 is connected to the data input terminal Din of the register 20 described above, and is also connected to the decoder 23.
The signal is supplied to one input terminal of the band circuit 24 via the ground circuit 24. The output terminal of the AND circuit 24 is connected to the reset terminal R of the counter 25, the flip-flop 19, and the register 20, and is also connected to the clock terminal CP of the counter 26 that counts the number of noise signals. 17 third input terminal.

Therefore, the output terminal of the counter 25 is connected to the decoder 27.
, are connected to the other input terminal of the AND circuit 18 via the inverter 28, and are also connected to the other input terminal of the AND circuit 24. And the above AND circuit 18
The output terminal of the counter 25 is supplied to the clock terminal CP of the counter 25. Further, the output terminal of the counter 26 is connected to the decoder 2.
9 to the set terminal S of the flip-flop 30. The reset terminal R of the flip-flop 30 is supplied with an initial reset signal (not shown) generated by the control section when the power is turned on (when the switch is turned on), and its set output Q indicates the number of occurrences of the noise signal as the set value. In this case, it is output as an error signal. Further, the output terminal DCut of the register 20 is connected to a code identification circuit (not shown). Thus, the decoder 27 receives the signal E when the count value of the counter 25, that is, the number of black information of the barcode exceeds a predetermined value (for example, 2).
This outputs the following.

Further, the decoder 29 generates an output when the count value of the counter 26, that is, the number of generated noise signals exceeds a preset number, and sets the flip-flop 30 to output an error signal. This is because a hand scanner is scanned while being held in a person's hand, so its movement speed is not constant. For this reason, for example, if the moving speed of the hand scanner is extremely slow, the value of the black portion of the barcode converted into time becomes extremely large, making identification impossible. Therefore, when the moving speed of the hand scanner is extremely slow, the time-converted value of the black part of the barcode becomes large, and many reset signals G are formed, which is used to cancel the argument operation. It is something. In other words, this prevents recognition of fraud even when the moving speed of the hand scanner is extremely slow. In addition, Figures 3a and 3b show enlarged portions of the barcodes shown in Figures 1a and 1b, respectively, and show the operation signals when this barcode is read. ，
In b, change the thick barcode mark of code 1 to 101
,102,...and a thin barcode mark 201,2
02,..., the width of the thick barcode mark is 1, the width of the thin barcode mark is 12, and the interval between each barcode mark is lo. And the leftmost green part of the thick barcode marks 101, 102, . . . is 101a,
102a,..., and the rightmost green is 101b, 102
b,... and a thin barcode mark 20
1, 202, ..., the leftmost green in the illustration is 201a, 202b
,..., and the right edge is 201b, 202b,
..... Further, in FIG. 3a, 4 is the shadow of the label 2, that is, a noise signal, as described above, and the width of this noise signal 4 is 14, and the right edge 4b and the first barcode mark (thick barcode mark 101) The distance from the edge green 101a is 13 (however, l3>lo). Further, in FIG. 3, numeral 5 is a bar-shaped pattern 5 drawn on the article as described above and visible through the label 2, that is, a noise signal, and the width of this noise signal 5 is assumed to be 15. Further, the output signal of the amplifier 13, that is, the read signal, is the signal A, the output of the differentiating circuit 14 is the signal B, the output of the differentiating circuit 16 is the signal C, the output of the decoder 27 is the signal D, the output of the inverter 28 is the signal E, and the output of the decoder 23 is the signal C. The output is shown by signal F, and the output of the AND circuit 24 is shown by signal G. Next, the operation of the present invention configured as described above will be explained.

The case where the bar code shown in FIG. 3a is taken will be explained. In this case, as described above, the interval 13 between the edge 4b of the noise 4 and the edge 101a of the thick barcode mark 101 is larger than the interval o between the respective barcodes. First, when the tip of the hand scanner 12 reaches the edge 4a of the noise, the read signal is amplified by the amplifier 13, and then differentiated by the differentiating circuit 14 to form the rising edge set signal B. Flip-flop 19 is set by signal B. The set output of the flip-flop 19 is ANDed with a clock signal that is continuously supplied by an AND circuit 21 and is supplied to a clock terminal of a counter 22. Therefore, the counter 22 starts counting as soon as the flip-flop 19 is set. Also, the rising IJ set signal B which is the output of the differentiating circuit 14
is input to the force counter 25, and the counter 25 counts the number of black signals. And this count value (for example 2)
When the signal D is reached, the decoder 27 outputs the signal D, and the inverter 28 outputs the signal E, which is input to the AND circuit 24.
Therefore, the signal output from the decoder 23 becomes valid only when the number of black parts of the read bar code is within a predetermined value, and is input to the flip-flop 19, counter 25, and register 20. The reset condition for the counter 22 is 1. A rising IJ set signal B formed in the differentiating circuit 14 at the left end green in the illustration of any of the black signals (1, 4, 5 in FIG. 1) is activated by the OR circuit 17. When supplied to the reset terminal R via the OR circuit 17, the falling IJ set signal C formed by the differentiating circuit 16 at the green right end of the black signal in the figure is supplied to the reset terminal R via the OR circuit 17 as described above. 3. When the count value of the counter 25 is less than a predetermined value (for example, 2) and the count value of the counter 22 reaches the predetermined value.

Therefore, the hand scanner 12 detects the end green 4a of the noise signal 4.
The counter 22, which starts counting when the noise signal 4 is reached, is set by the differentiating circuit 16 when the hand scanner 12 reaches the right end green 4b of the noise signal 4. The output signal C of the differentiating circuit 16 is also supplied to the clock terminal CP of the register 20, and when the falling edge set signal C, which is the output of the differentiating circuit 16, is input to this clock terminal CP, that is, the hand scanner 12 is activated. When the right edge 4b of the noise signal 4 is reached, the value of the counter 22, that is, the value obtained by converting the width 14 of the noise signal into time, is stored in the register 20.

The counter 22 is reset by the set signal C of the falling edge of the right edge 4b of the noise signal 4, but since the flip-flop 19 remains set, it starts counting again. The hand scanner 12 detects the green 1 at the edge of the regular barcode mark 101 for the next set of counters 22.
01a, but in this case, the length 13 between the noise signal 4 and the barcode mark 101 is longer than the length lo between the barcode marks, so the count of the counter 22 that counts the length 13 When the output becomes larger than the preset value 23 of the decoder, the decoder 23 outputs a signal F, and this signal F is supplied to the AND circuit 24. Therefore, if the value of the decoder 27 does not reach a predetermined value (for example, 2), a reset signal G is generated in the AND circuit 24. The reset signal G is then supplied to the reset terminal R of the resistor 20, and the time-converted value of the previously stored noise signal 4 is reset and is not output from the output terminal Dout.
Further, the reset signal G output from the AND circuit 24 is supplied to the reset terminal of the flip-flop 19 and also to the clock terminal CP of the counter 26. As a result, the counter 22 stops operating, and the counter 26 counts the number of noise signals 4. When the count value of the counter 26 also reaches a predetermined value, an output is generated in the decoder 29, which sets the flip-flop 30 and generates an error signal. When the tip of the hand scanner 12 advances further and reaches the left edge green 101a of the barcode mark 101, the flip-flop 19 is set by the rising set signal B as described above, and the counter 22 starts counting. When the right end green 101b is reached, the falling IJ set signal C is sent to the register 20 and counter 2.
2, the counter 22 is reset, and the time-converted value of the paralysis in the code mark 101 is stored in the register 20.
One item is memorized. Then, when the hand scanner 12 advances further and reaches the edge 201a of the bit mark 201,
At this time, since the interval o between the code mark 101 and the code mark 201 is within a predetermined value, the decoder 23 does not generate an output. hand scanner 12
When it reaches the right end green 201b of the code mark 201, the time conversion value of Nakazono 2 of the code mark 201 is stored in the register 201.

The transfer register 20 is a shift register, and the time conversion value of 12 is stored next to the time conversion value of 1. Similarly, regular barcode marks 102, 202, 103,
The time-converted values of width 203, . , is determined as a value of "1" or "0". Also, when there is a noise signal as shown in FIG. 3b, the flip-flop 19 is set at the edge 5a of the noise signal 5 and the counter 22 starts counting, as in the previous embodiment.
When the width 15 of this noise signal 5 is larger than a predetermined value set in the decoder 23, an output is generated in the AND circuit 24, which resets the flip-flop 19, the force counter 22, the register 20, and the force counter 25, and outputs the noise signal. ignore. Note that the number of noise signals can be ignored as long as it is within the value set by the counter 26, and in this way, even if an unnecessary noise signal exists before a normal code, it is ensured that the normal code signal Only the riddles can be taken.

In this embodiment, the counter 25 counts the number of black information, and for example, when the first black part of the barcode is read,
When this reaches the left end of the next barcode without being reset, the glue set signal from the decoder 23 is invalidated.

Therefore, in this embodiment, only the noise signal at the leading end of the barcode is removed, but the noise signal at the middle part of the barcode is not removed. However, in general, the movement speed of a barcode operated by a person varies greatly depending on individual differences, but when one person performs a single operation, the operation speed at the front, middle, and rear ends of the barcode changes not much. There is no. Therefore, as long as the speed at which the front end can be read, normal reading is possible even at the middle and rear ends. Further, if noise is present in the middle part and rear end part of the barcode, although this is not explained in this embodiment, it is also possible to use it as an error signal in the same manner as in the subordinate part. As described above, according to this explanation, it is possible to reliably eliminate the influence of unnecessary noise signals that exist before a regular barcode, and it is possible to provide an information reading device with extremely excellent operability.

[Brief explanation of drawings]

Figures 1a and b are diagrams showing an example of barcode information in which noise signals were present, Figure 2 is a circuit diagram showing an embodiment of the present invention, and Figures 3a and b are diagrams showing an example of barcode information in which noise signals were present. FIG. 6 is a partially enlarged view of each of the figures. 1...Barcode, 12...Hand scanner, 14,1
6... Differential circuit, 19, 30... Flip-flop, 20... Register, 22, 25, 26...
...Power counter, 23, 27, 29...Decoder. Figure 1 Figure 2 Figure 3

Claims (1)

[Claims] 1 A reading means for scanning and reading barcode information composed of a plurality of barcode marks, a means for generating a clock signal, and a black signal portion and a white signal portion by counting the clock signal based on the output of the reading means. a counting means for counting the number of clock signals in the signal portion; a storage means for storing the counting output in the black signal portion among the counting outputs of the counting means; and a counting output of the counting means in the black signal portion or the black signal portion. 2. An information reading device comprising: means for resetting said storage means when the counting output of said counting means in a white signal portion following a white signal exceeds a predetermined value.