JPH0363783B2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a pattern reading device for paper sheets,
For example, a pattern used in automatic teller machines, etc., which reads patterns such as letters and patterns printed on the surface of paper sheets during the transportation process, and is used for processing operations such as determining authenticity. Regarding a reading device.

In automatic teller machines and the like, a paper roll is inserted into an insertion slot so that its longitudinal direction is horizontal.
The inserted paper is taken into the device, and in the process, the pattern of a specific track on the paper is read, and authenticity can be determined based on whether the pattern matches a pre-stored pattern. It is done.

FIG. 1 is an illustrative diagram for explaining the principle of a conventional pattern reading device. In the figure, paper sheets 1
is transported in the X direction by the transport belt 2. During this conveyance process, the patterns on the symmetrical tracks 1a and 1b of the paper sheet 1 are detected by the photoelectric sensors A and B.
read by. The purpose of reading the symmetrical patterns of tracks 1a and 1b in this way is to improve the accuracy of authenticity determination and to reduce the number of model patterns stored in the memory in advance. That is, when conveying the paper sheet 1, it may be conveyed with its end 1A facing forward, or may be conveyed with its edge 1B facing forward;
It is sometimes carried upside down with 1A or 1B facing forward. Therefore, if the model patterns of the symmetrical tracks 1a and 1b are stored in advance, the paper sheet 1 can be processed no matter which direction it is conveyed by simply changing the order in which the model patterns are read.

However, when the paper sheet 1 is displaced in the path width direction Y perpendicular to the conveyance direction
1b is shifted from the position of sensors A and B. Therefore, sensors A and B read the patterns of other tracks, causing malfunctions in determining authenticity. In order to prevent such malfunctions, a method may be considered in which all track patterns included in the displacement width of the paper sheet 1 are stored in advance in a memory. However, in this method, when a read pattern is compared, if there is a correspondence with any one of a plurality of patterns, it is determined to be true, so the determination accuracy decreases.

Furthermore, if the displacement range of the paper sheet 1 is predicted to be large, it is necessary to store a large number of track patterns in the memory, which undesirably increases the memory capacity.

SUMMARY OF THE INVENTION Therefore, the main object of the present invention is to provide a paper sheet pattern reading device that can reliably read a predetermined symmetrical track pattern even if the paper sheet is displaced and conveyed. That's true.

To summarize the invention, a first
and a second image sensor is arranged so that the first image sensor reads one end of the paper sheet and a pattern of one of the two target tracks,
A second image sensor reads the pattern on the other end of the sheet and the other track. and,
The first and second image sensors are sequentially scanned toward the center of the paper sheet, and after some sensor elements included in the first image sensor detect one end of the paper sheet, one of the two tracks is scanned. The image sensor reading output corresponding to one track is sampled according to the elapse of time until the sensor corresponding to the second track is scanned, and some sensor elements included in the second image sensor scan the paper sheet. It is configured to sample the readout output of the image sensor corresponding to the other track depending on the time elapsed from detecting the other end to scanning the sensor corresponding to the other track. be.

The present invention will be described in more detail below along with embodiments shown in the drawings.

FIG. 2 and FIGS. 3A to 3C are diagrams for explaining the principle of an embodiment of the present invention.
First, referring to FIG. 2, image sensors 3 and 4 forming first and second sensor arrays are arranged in a direction intersecting the direction in which conveyor belt 2 extends. An example of such an image sensor is
CCD type line sensors etc. are used. In such image sensors 3 and 4, for example, a light source (not shown) such as a lamp is placed below the paper sheet 1, and the pattern of the paper sheet 1 is projected by the light from this light source. This is detected.
The image sensor 3 is configured to read the pattern of the end of the sheet 1 in the direction intersecting the conveying direction X and the track 1a, and the image sensor 4 is configured to read the pattern of the other end of the sheet 1 and the track 1b. is configured to read the pattern of

As shown in FIG. 3A, when the paper sheet 1 is conveyed to the correct position by the conveyor belt 2, the sensor 3a included in the image sensor 3 detects one end of the paper sheet 1, and the sensor 3b detects one end of the paper sheet 1. Read the pattern of track 1a. Further, the sensor 4a included in the image sensor 4 detects the other end of the paper sheet 1, and the sensor 4a included in the image sensor 4 detects the other end of the sheet 1.
b reads the pattern of track 1b. Further, as shown in FIG. 3A, when the paper sheet 1 is displaced in the Y1 direction, the sensor 3c detects one end of the paper sheet 1, and the sensor 3d reads the pattern of the track 1a. Further, the sensor 4c of the image sensor 4 detects the other end of the paper sheet 1, and the sensor 4d detects the other end of the paper sheet 1.
Read pattern b. Furthermore, when the paper sheet 1 is displaced in the Y2 direction as shown in Fig. 3C,
The sensor 3e detects one end of the paper sheet 1, and the sensor 3e detects one end of the paper sheet 1.
f reads the pattern of track 1a. Further, the sensor 4e detects the other end of the paper sheet 1, and the sensor 4f
reads the pattern on track 1b. In this way, even if the paper sheet 1 is displaced in a direction crossing the conveyance direction
By reading the patterns with sensors corresponding to the respective patterns, it is possible to ensure that tracks 1a and 1b
It becomes possible to read the pattern of

FIG. 4 is a schematic block diagram of one embodiment of the present invention, FIG. 5 is a concrete block diagram of the change detection circuits 10a and 10b included in FIG. 4, and FIG. 6 is a delay circuit as well. 11a and 11b, and FIG. 7 is a specific block diagram of the sample and hold circuits 8a and 8b.

Next, the configuration of an embodiment of the present invention will be described with reference to FIGS. 4 to 7. The oscillator 5 generates a clock signal a, and constitutes a clock signal generating means. The clock signal a output from this oscillator 5 is applied to the image sensors 3 and 4.
and the sensors included in each are sequentially scanned. Furthermore, the clock signal a is applied to the counter 6, change detection circuits 10a and 10b, and delay circuits 11a and 11b. A reading command signal is given to the counter 6. And counter 6
When the read command signal is given, the clock signal a
A start signal b synchronized with is output and applied to the image sensors 3 and 4. A read signal from the image sensor 3 is amplified by an amplifier 7a, and is applied to a sample and hold circuit 8a, as well as to a comparison input terminal of a comparator 9a. A reference signal V is applied to a reference input terminal of the comparator 9a. Then, the comparator 9a compares the read signal and the reference signal V, and if the level of the read signal is equal to or higher than the reference signal V, provides an output signal to the change detection circuit 10a.

The change detection circuit 10a includes D-type flips 101 and 102 and an EXOR gate 103 as shown in FIG.
, an inverter 104, and an AND gate 105. As shown in FIG. 3A, this change detection circuit 10a detects a change based on the read signal of the image sensor 3.
It detects one end of the paper sheet 1, and constitutes a first end detection means. This change detection circuit 10
The detection signal h of a is given to the delay circuit 11a.

The delay circuit 11a includes an inverter 111 and a preset counter 112, as shown in FIG. This delay circuit 11a delays the detection signal of the change detection circuit 10a by a predetermined time. That is, as shown in FIG. 3A, for example, the delay circuit 11a detects one end of the paper sheet 1 after the sensor 3a included in the image sensor 3 detects the sensor 3b.
The scanning time until the pattern on track 1a is read is counted. The delayed output signal i of this delay circuit 11a is given to a sample hold circuit 8a and an AD converter 12a. Sample hold circuit 8
a samples the read output of the image sensor 3 when a delayed output signal, ie, a sample pulse i is applied.

The sample hold circuit 8a includes an analog switch 81, a capacitor 82, and an operational amplifier 83, as shown in FIG. Sample hold circuit 8a
The read signal of the track 1a sampled at 1 is applied to an A/D converter 12a. The A/D converter 12a is activated by the sample pulse i and converts the read signal into a digital value and stores it in the memory 13.

Note that the read signal of the image sensor 4 is also sent to the sample hold circuit 8 via the amplifier 7b.
given to b. Also, this read signal is transmitted to the comparator 9.
b is also applied and compared with the reference signal V, and the other end of the paper sheet 1 is detected by the change detection circuit 10b. The detection signal is then delayed by the delay circuit 11b, and the delayed output is given to the sample and hold circuit 8b and the AD converter 12b. The output signal of the sample hold circuit 8b is sent to the A-D converter 12b.
It is converted into a digital value and stored in the memory 13.

FIGS. 8 and 9 are waveform diagrams of each part of FIGS. 4 to 7.

Next, the specific operation of one embodiment of the present invention will be described with reference to FIGS. 2 to 9. In addition, in the following explanation, in order to simplify the explanation,
Only the image sensor 3 side will be explained. When the read command signal is applied to the counter 6, the counter 6 generates a start signal b in synchronization with the clock signal a. This start signal b and clock signal a
When this is applied to the image sensor 3, the image sensor 3 starts reading sequentially toward the conveyor belt 2 side.

When the paper sheet 1 is conveyed in the X direction by the conveyor belt 2 and passes the position where the image sensor 3 is arranged, the sensor 3a detects the edge of the paper sheet 1 in the example shown in FIG. 3A. . Then, as shown in FIG. 8, the level of the read output of the image sensor 3 becomes relatively high. The output signal of this image sensor 3 is amplified by an amplifier 7a, and compared with a reference signal by a comparator 9a. When the next sensor is scanned after the sensor 3a is scanned, the output level of the image sensor 3 becomes lower than the reference signal. The output signal d of the comparator 9a is input to a D-type flip-flop 101 included in the change detection circuit 10a. Then, the D-type flip-flop 101 stores the output of the comparator 9a based on the clock signal a. The output signal e of this D-type flip-flop 101 is stored in the D-type flip-flop 102 by the next clock signal a. And EXOR
Gate 103 takes the exclusive OR of output signal e of D-type flip-flop 101 and output signal f of D-type flip-flop 102, and outputs a sample gate signal g. This sample gate signal g is
By the AND gate 105, the inverter 104
The sample pulse signal h is output from the AND gate 105 in synchronization with the clock signal a applied via the AND gate 105. This sample pulse signal h is delayed by a predetermined time by a delay circuit 11a. The delayed signal i is then given to the sample and hold circuit 8a and the AD converter 12a. The sample hold circuit 8a samples the read output of the image sensor 3 based on the sample pulse i. That is, the analog switch 81 is controlled by the sample pulse i, and the analog value of the read signal input during the sampling period, that is, the read signal c of the pattern of the track 1a, is given to the capacitor 82, and the analog hold signal is output via the operational amplifier 83. j is output. The level of this analog hold signal j is held until the next sample pulse signal i is applied to the analog switch 81. Therefore, the analog hold signal j has a stepwise waveform as shown in FIG.

Therefore, this analog hold signal j has extracted only the pattern data of the track 1a to be read based on the sample pulse signal i, and this analog hold signal After being converted into a digital signal by the converter 12a, the memory 13
is memorized.

On the other hand, in the image sensor 4, the sensor 4a detects the other end of the paper sheet 1, and the read signal of the pattern of the track 1b detected by the sensor 4b is stored as a digital signal in the memory 1.
3 is stored. Then, the pattern data of each of the tracks 1a and 1b is compared with previously stored data to determine whether the pattern is genuine or false.

In addition, as shown in FIG. 3B, the paper sheet 1 is
Even when the paper sheet 1 is displaced in the Y1 direction or in the Y2 direction as shown in Figure 3C, the read signal of the scanned sensor is sampled after a predetermined period of time has passed after detecting the edge of the paper sheet 1. Therefore, I always select specific tracks 1a and 1b.
patterns can be read.

FIGS. 10A and 10B are diagrams for explaining the principle of another embodiment of the present invention. first,
Referring to FIG. 10A, four image sensors 20 to 23 are arranged in a direction intersecting the conveying direction of paper sheet 1. As shown in FIG. The image sensor 20 is a first end detection sensor array and is arranged at a position where one end of the paper sheet 1 passes.
is a first track detection sensor array, which is arranged at a position where the track 1c passes. Further, the image sensor 22 is a second end detection sensor array, and is arranged at a position where the other end of the paper sheet 1 passes,
The image sensor 23 is a second track detection sensor array and is arranged at a position through which the other track 1b passes. Each of the image sensors 20 to 23 is scanned toward the center of the sheet 1 in synchronization with the clock signal. When the sensor 20a included in the image sensor 20 detects one end of the paper sheet 1, a reading signal is output from the sensor 21a of the image sensor 21 scanned in correspondence with the sensor 20a. Further, when the sensor 22a included in the image sensor 22 detects the other end of the paper sheet 1, the sensor 23a of the image sensor 23 is scanned corresponding to this sensor 22a.
Outputs the read signal from. In this way, paper sheets 1
10B and 1 by outputting read signals from the sensors 21a and 23a that are scanned in correspondence with the sensors 20a and 22a that have detected the ends of the
As shown in Figure 0C, even if the paper sheet 1 is displaced in the Y1 direction or the Y2 direction, the patterns of the tracks 1c and 1d can be read without fail.

FIG. 11 is a schematic block diagram of another embodiment of the invention. This FIG. 11 is the same as FIG. 4 except for the following points. That is, image sensor 2
0 to 23, start signal b from counter 6
is given. The read signal from the image sensor 20 is then given to the comparator 9a via the amplifier 7a. Further, the read signal of the image sensor 21 is given to the sample hold 8a via the amplifier 24a. Further, the read signal of the image sensor 22 is given to the comparator 9b via the amplifier 7b. A read signal from the image sensor 23 is applied to a sample and hold circuit 8b via an amplifier 24b.

FIGS. 12 and 13 are waveform diagrams of each part in FIG. 11.

Next, the operation of another embodiment of the present invention will be described with reference to FIGS. 10A to 13. In addition, to simplify the explanation, image sensor 2
Only the 0 and 21 sides will be explained. The image sensors 20 and 21 receive a clock signal a and a start signal b.
are scanned synchronously. Then, as shown in Figure 10A,
When the sensor 20a included in the image sensor 20 detects one end of the paper sheet 1, the detection signal is given to the comparator 9a via the amplifier 7a and compared with the reference signal v. The change detection circuit 10a is a comparator 9
Based on the output signal of a, a level change caused by detecting one end of the paper sheet 1 is detected, and a sample pulse i is provided to the sample hold circuit 8a.

When the sensor 20a included in the image sensor 20 detects one end of the paper sheet 1, a read signal from the sensor 21a of the image sensor 21 being scanned corresponding to the sensor 20a is sent to the sample hold circuit 8a via the amplifier 24a. Since it is given
The sample and hold circuit 8a samples the read signal. The analog hold signal j sampled by the sample hold circuit 8a is converted into a digital signal by the A/D converter 12a activated by the sample pulse i and stored in the memory 13.

Regarding the image sensors 22 and 23, when the sensor 22a detects the other end of the paper sheet 1 in the same manner as described above, the read signal of the sensor 23a scanned corresponding to this sensor 22a is sent to the sample hold circuit. 8b, and the analog hold signal j is sent to the A-D converter 12.
b converts it into a digital signal and stores it in memory 1.
3 is stored.

Therefore, as shown in FIGS. 10B and 10C, even if the paper sheet 1 is displaced and conveyed, when the image sensors 20 and 22 detect the edge of the paper sheet 1, the edge By reading the outputs of the sensors included in the image sensors 21 and 23 that are being scanned in accordance with the sensor that detected the pattern, it is possible to read the pattern of the specific track 1c or 1d without fail.

As described above, according to the present invention, a pair of image sensors are arranged in a direction intersecting the conveyance direction of paper sheets, and the scanning means scans the paper sheets, and some of the sensor elements of each image sensor The read signal of the image sensor corresponding to one predetermined track is sampled according to the elapsed time from when the sensor element is detected to when the sensor element corresponding to each of the two tracks is scanned. Even if the paper sheet is transported after being displaced in a direction intersecting the transport direction, a specific track pattern can always be read. Therefore, when determining authenticity, it is not necessary to store model patterns of a plurality of tracks in memory in advance, and the memory capacity can be reduced. Furthermore, since the pattern compared with the model pattern stored in the memory is always a specific pattern, the discrimination accuracy can be improved.

[Brief explanation of drawings]

FIG. 1 is an illustrative diagram of a conventional pattern reading device. FIG. 2, FIG. 3A, FIG. 3B, and FIG. 3C are diagrams for explaining the principle of an embodiment of the present invention. FIG. 4 is a schematic block diagram of one embodiment of the present invention. FIG. 5 is a concrete block diagram of the change detection circuit shown in FIG. 4. FIG. 6 is a concrete block diagram of the same delay circuit. FIG. 7 is a concrete block diagram of the sample and hold circuit. FIGS. 8 and 9 are waveform diagrams of each part of FIGS. 4 to 7. Figure 10A, 10
FIG. B and FIG. 10C are diagrams for explaining the principle of another embodiment of the present invention. FIG. 11 is a schematic block diagram of another embodiment of the invention. 1st
2 and 13 are waveform diagrams of each part in FIG. 11. In the figure, 1 is paper sheets, 2 is a conveyor belt,
3, 4, 20-23 are image sensors, 5 is an oscillator, 8a, 8b are sample and hold circuits, 9a,
9b is a comparator, 11a and 11b are delay circuits, 12
12a and 12b are A-D converters, and 13 is a memory.

Claims (1)

[Scope of Claims] 1. A pattern reading device that includes a conveyance means for conveying paper sheets and reads patterns of two predetermined tracks symmetrically located from both ends parallel to the conveyance direction of the paper sheets. A plurality of sensor elements are arranged in a line in a direction intersecting the conveying direction of the paper sheet, at least a part of which detects one end of the paper sheet, and one of the two predetermined tracks a first image sensor that reads a pattern of the paper sheets, a plurality of sensor elements are arranged in a line in a direction intersecting the conveying direction of the paper sheets, at least a part of which detects the other end of the paper sheets; a second image sensor that reads the other pattern of two predetermined tracks; a scanning device that sequentially scans the first and second image sensors toward the center of the sheet; included in the first image sensor; When the time elapses from when some of the sensor elements detected one end of the paper sheet until the scanning means scans the sensor element corresponding to one of the two tracks, the predetermined two tracks are scanned. a first sampling command means for instructing sampling of the read output of an image sensor corresponding to one of the image sensors; after some sensor elements included in the second image sensor detect the other end of the paper sheet; second sampling command means for commanding sampling of the read output of the image sensor corresponding to the two predetermined tracks when the time elapses until the scanning means scans the sensor element corresponding to the other of the two tracks; , a first sampling means for sampling the read output of a corresponding sensor element of the first image sensor in response to a sampling command given from the first sampling command means, and the second sampling command. A pattern reading device for paper sheets, comprising a second sampling means for sampling a read output of a corresponding sensor element of the second image sensor in response to a sampling command given from the means. 2. The first and second image sensors are each configured to output a reading signal of the pattern by being supplied with a pulse signal, and the scanning means generates a clock signal to read the pattern. 2. The paper sheet pattern reading device according to claim 1, further comprising clock signal generating means for applying to the first and second image sensors. 3. The first sampling command means includes first edge detection means that derives a detection signal in response to detection of one end of the paper sheet by any sensor element of the first image sensor; a first delay means for delaying the output of the first edge detection means by the predetermined time; a second edge detection means for deriving a detection signal in response to detecting the other edge of the leaf; and a second delay means for delaying the output of the second edge detection means by the predetermined time. , a paper sheet pattern reading device according to claim 2. 4. The first delay means counts a number of clock signals corresponding to the predetermined time in response to the output of the first edge detection means being applied.
the second delay means includes a second counting means for counting a number of clock signals corresponding to the predetermined time in response to the output of the second edge detection means being applied. A paper sheet pattern reading device according to claim 3, comprising means. 5. The first image sensor includes: a first end detection sensor array arranged at a position through which one end of the paper sheet passes; and a first end detection sensor array arranged at a position through which one of the two trucks passes. a track detection sensor array, the second image sensor includes: a second edge detection sensor array arranged at a position through which the other end of the paper sheet passes; and a second edge detection sensor array through which the other end of the two tracks passes. a second track detection sensor array arranged at a position, and the scanning means includes the first end detection sensor array, the first track detection sensor array, and the second end detection sensor array. 3. The paper sheet pattern reading device according to claim 2, wherein said second track detection sensor array scans each of said paper sheets in a synchronized manner toward the center of said paper sheets. 4. The first sampling command means scans in synchronization with the scanning of the sensor in response to any sensor of the first end detection sensor array detecting one end of the paper sheet. the second sampling command means commands sampling of the readout output of the sensor of the first track detection sensor array;
When one of the sensors in the end detection sensor row detects the other end of the paper sheet, one of the sensors in the second track detection sensor row is scanned in synchronization with the scanning of the sensor. Claim 5, wherein sampling of read output is commanded.
The paper sheet pattern reading device described in Section 1.