JPS58101371A - Pattern reader for paper sheet - Google Patents

Abstract

PURPOSE:To read two track patterns symmetrical to a center axis being a specific distance from both ends of paper sheets by using a single sensor train. CONSTITUTION:When a paper sheet 6 is carried on a carrying path and the front edge of the paper reaches near light sources 11, 12, a reading command is given from a paper detection means (not shown) to a counter 22. Then, the counter 22 generates a start signal (b) in synchronizing with a clock signal (a), a light source drive circuit 30 illuminates one of the light sources 11, 12 by receiving the start signal and an image sensor 18 starts scanning according to the clock signal (a). When the light source 11 is illuminated, the light from the light source 11 transmits through the paper 6 partly, the other light is reflected on mirrors 13 and 15, collected at a lens 17 and the image is formed on the image sensor 18.

Description

[Detailed description of the invention] The present invention relates to a pattern reading device for paper sheets.

For example, in the process of transporting paper sheets such as banknotes used in automatic teller machines, processing operations such as authenticity determination by reading patterns such as letters and designs printed on the surface of the paper sheets (pattern reading) Regarding equipment.

BACKGROUND ART Conventionally, for example, in an automatic teller machine, a pattern of a banknote is read by one or two sensors fixed on a conveyance path while the banknote is conveyed in the direction of its short side. For this reason, if the banknotes were conveyed in a direction intersecting the conveyance path, an unusual track pattern would be read, resulting in malfunctions in authenticity determination.

Therefore, the present inventors have proposed that even if paper sheets are conveyed unevenly,
As shown in Figure 1, a paper sheet pattern reading device that can reliably read a track pattern that is symmetrical to a predetermined central axis of a paper sheet uses a plurality of sensor units connected in series. Two sensor rows 1 arranged in
．． 2 are disposed on both sides of a conveyance path 5 consisting of conveyor belts 3 and 4, intersecting the conveyance direction First, the edges 7°8 of the paper sheet 6 are detected, and then the signals of the sensor units 1b and 2b located a predetermined distance away from the sensor units 1m and 2m that detected this edge are sampled. In November 1980, he devised a pattern reading device that is characterized by reading the pattern of tracks 9 and 10 located at a predetermined distance from both ends 7 and 8 of Class 6.
The patent application was filed on May 5th for a patent application for a paper sheet pattern reading device.

However, the device of this prior application requires two sensor rows such as image sensors, and if you try to perform the same operation with only one sensor row as shown in FIG. When scanning upwards (in the Y direction), the upper track lO is not known until the upper edge 8 of the paper sheet 6 is detected. must be memorized, so such a method is virtually impossible.

An object of the present invention is to solve the above-mentioned problems with the conventional type, and to read the pattern of two axially symmetrical tracks at a fixed distance from both ends of the paper sheet using a single sensor array. The object of the present invention is to provide a reading device.

In order to achieve the above object, the present invention includes a conveyance means for conveying paper sheets, and a predetermined pattern of two tracks at symmetrical positions from both ends parallel to the conveyance direction of the paper sheets. A pattern reading device for reading with a single sensor array, which is arranged in a direction intersecting the conveying direction of the paper sheets and includes at least one end of the paper sheets and one of the two tracks. Two light sources that are turned on alternately to illuminate the range independently, and a plurality of mirrors that collect transmitted light or reflected light from the paper sheet obtained by turning on these light sources alternately on the sensor row. The plurality of mirrors are oriented in the same direction with respect to the central axis of the light source on the sensor row, and the sensor row is scanned in synchronization with the alternate lighting of the light source, so that the paper is isometrically illuminated. The feature is that it is possible to scan the leaf alternately and sequentially from both ends to the center.

The present invention will be explained in detail below with reference to the drawings. Note that parts common to or corresponding to those in the prior art are represented by the same reference numerals.

FIG. 3 is a configuration diagram showing the main parts of a pattern reading device for paper sheets according to an embodiment of the present invention, and a is a plan view.

b is a side view. In the figure, light sources 11 and 12 are arranged below each end 7 and 8 of the paper sheet 6 being conveyed on a conveyance path (not shown) consisting of a conveyance belt, and are located at the left and right sides of the conveyance path, respectively. are irradiated independently. Further, these light sources 11 and 12 are turned on alternately. Mirrors 13 and 14 are respectively placed directly above the light sources 11 and 12, and are
parallel to the axis (conveying path center axis) and the xy plane (conveying plane)
The power is distributed at an angle of about 45' towards the center. The mirrors 15 and 16 are arranged in a V-shape between the mirrors 11 and 12, parallel to the two axes (axes perpendicular to the conveyance plane), and inclined by about 4 cf from the X axis. Lens 17 is V
Roughly in front of the letter-shaped mirror 15.16 in the X direction, the image sensor 18 is arranged at a position opposite to the mirror 15.16 with respect to the lens 17. Therefore, the image in the Y direction on the paper sheet 6 by the light source 11 is converted into two directions by the mirror 13, and the image on the paper sheet 6 is converted into two directions by the mirror 13. The lens 17 projects images onto the image sensor 18 in two directions. Similarly.

The image in the −Y direction on the paper sheet 6 produced by the light source 12 is reflected by the mirror 14
Since the image sensor 1 is converted into two directions by
8 as images in two directions. That is, by scanning the image sensor 18 in the z direction, the image of the paper sheet 6 by the light source 11 is scanned from left to right (Y direction), and the image by the light source 12 is scanned from right to left (-Y direction). , in either case, scanning is performed from the outside to the inside.

FIG. 4 shows an example of an electrical circuit for use in the apparatus of FIG. In the figure, 21 is an oscillator that generates a clock signal a, 22 is a counter that generates a start signal based on a reading command signal that is issued when, for example, a paper sheet 6 is conveyed to a predetermined position, and 23 is an increaser. 24 is a comparator that compares the reference level V with the output of the amplifier 23, that is, the read signal C, 25 is a change detection circuit, 26 is a delay circuit, 27 is a sample and hold circuit, and 28 is an A-D converter. , 29 is a memory, 30 is a light source driving circuit, 11 and 12 are the same light sources as shown in FIG. 3, and 18 is an image sensor.

The image sensor 18 accumulates charge according to the amount of incident light in each sensor unit, and outputs in chronological order the analog level taken in during the previous scan 4 which is proportional to the amount of accumulated charge in synchronization with a clock signal.

The change detection circuit 25 receives the read signal C of the image sensor 18.
It detects the edges of paper sheets based on
D-type flip-flop 251.25 as shown in FIG.
2, EXOR gate 253, inverter 254, AND
gate 255. In this change detection circuit 25, the output signal d of the comparator 24 is transferred to the D-type flip-flop 25.
1, the D-type flip-flop 251 stores the output of the comparator 24 based on the clock signal a.

The output signal e of this DW flip-flop 251 is stored in the D-type flip-flop 252 by the next clock signal a. Then, the EXOR gate 253 takes the exclusive OR of the output signal e of the D-type 7 flip-flop 251 and the output signal f of the D-type flip-flop 252, and outputs the sample gate signal g. This sample gate signal g is synchronized with the clock signal a given via the inverter 254 by an AND gate 255, and
A change detection signal is output from the gate 255. The detection signal of this change detection circuit 25 is given to a delay circuit 26.

The delay circuit 26 delays the detection signal of the change detection circuit 25 by a predetermined time! , includes an inverter 261 and a preset counter 262, as shown in FIG. In this delay circuit 26, when an edge 7.8 of the paper sheet 6 is detected in one of the sensor units included in the image sensor 18, a predetermined track 9.10 located a predetermined distance away from this sensor unit is detected. The time until the other sensor unit that is detecting the sensor is scanned is measured. The delayed output signal i of this delay circuit 26 is given to a sample hold circuit 27 and an A-D converter 28.

The sample and hold circuit 27 samples the read output of the image sensor 18 when a delayed output signal, that is, a sample pulse i is applied, and as shown in FIG. include.

In this sample hold circuit 27, the analog switch 271 is controlled by the sample pulse i, and the analog value of the read signal C input manually during the sampling period, that is, the read signal C of the pattern of a predetermined track 9 or 10, is applied to the capacitor 272. Analog hold signal j is output via operational amplifier 273. The level of this analog hold signal j is held until the next sample pulse signal i is applied to the analog switch 2711. The read signals of tracks 9 and 10 sampled by the sample and hold circuit 27 are sent to an A-D converter 28.
given to. The A/D converter 28 is activated by the sample pulse i and converts the read signal into a digital value and stores it in the memory 29.

On the light source side, the dynamic circuit 30 is connected to the inverter 3 as shown in FIG.
01 and JK flip 70 tube 302 and driver amplifier 3
03 and 304, and each time a start signal is given from the counter 22, the light source drive signal is inverted to 1, and the light sources 11 and 12 are turned on alternately.

Next, the operation of the apparatus shown in FIG. 3 will be explained with reference to FIGS. 3 to 1θ.

The paper sheet 6 is transported along a transport path (not shown), and when the leading edge of the paper sheet reaches the vicinity of the light source 11.12, a reading command is given to the counter 22 from a paper sheet detection means (not shown).

Then, the counter 22 generates a start signal S in synchronization with the clock signal a.

Upon receiving this start signal, the light source drive circuit 30 starts driving the light source 1.
1. At the same time when one of the 12 lights up, the image sensor 18
starts scanning from the bottom to the top (in two directions) in FIG. 3 in accordance with the clock signal a.

Assuming that the light source 11 is lit now, the light source 11
A part of the light passes through the paper sheet 6, and the other part is directly reflected by the mirrors 13 and 15, condensed by the lens 17, and formed into an image on the image sensor 18.

Therefore, by scanning the image sensor 18 from the bottom to the top (two directions) in the third diagram, the light source 11 and the paper sheet 6 are scanned from the left to the right (Y direction) in the third diagram. Similarly, when the light source 12 is turned on, the light from the light source 12 is reflected by the mirrors 14 and 16, and then condensed by the lens 17 to form an image on the image sensor 18. If the image sensor 18 is scanned in two directions, The light noodles 12 and paper sheets 6 are scanned from right to left (-Y direction) in FIG. That is, although the image sensor 18 always scans in two directions, the paper sheet 6 etc. is scanned from the outside to the inside.

In the image sensor 18 , first, the part where the light from the light source 11 or 12 is directly incident is scanned, so the read signal C from the image sensor 18 is higher than the reference level of the comparator 24 , and therefore the read signal C of the comparator 24 is The output d is at the ``H'' level, but next, when the light passes through the edge 7 or 8 of the paper sheet 6 and scans the part where the light is blocked by the paper sheet 6, the read signal - returns to the reference level. (2), and the comparator output d becomes L'' level. Based on this change in the comparator output d, the change detection circuit 25 outputs a change detection signal.

This change detection signal is delayed by a predetermined time by a delay circuit 26, and this delayed output signal i is given to a scramble hold circuit 27 and an A/D converter 28. The sample hold circuit 27 samples the read output C of the image sensor 18 when the sample pulse i is output, and outputs an analog hold signal j.

Therefore, for this analog hold signal j.

Based on the sample pulse signal i, only 10 pattern data to be read are extracted, and this analog hold signal j is converted into a digital signal by the A-D converter 28 activated by the sample pulse signal i. After being converted into a signal, it is stored in the memory 29.

Repeat the above operation until the paper sheet 6 passes, and then
When light source 12 is lit, the right track in Figure 3 is read and stored, and when light source 12 is lit, the left track is read and stored, etc. It is possible to read the pattern of two specific tracks symmetrical about the central axis in the conveying direction of the paper sheet.

[Brief explanation of the drawing]

1 and 2 are diagrams for explaining the principle of a conventional pattern reading device, and FIGS. 3a and 3b show the configuration of essential parts of a pattern reading device according to an embodiment of the present invention. FIG. 4 is a plan view, b is a side view, and FIG. 4 is an electric circuit diagram used in the device of FIG. 3. Figures 5 to 8 are specific block diagrams of the change detection circuit, delay circuit, sample and hold circuit, and light source drive circuit shown in Figure 4, respectively, and Figures 9 and 10 are waveforms of each part in Figures 4 to 8. It is a diagram. 6...Paper leaf, 11.12...Light source, 13
゜14.15.16...Mirror, 17...Lens, 18.1. Image sensor, 30... light source drive circuit. Figure 1 Figure 2 (b> Figure 4 2 @ Figure 5 62 Figure 7 ■ Figure 8

Claims (1)

[Scope of Claims] t includes a conveyance means for conveying paper sheets, and a pattern of two predetermined tracks at symmetrical positions from both ends parallel to the conveyance direction of the paper sheets is formed by a single sensor array. A pattern reading device for reading. two light sources that are arranged in a direction intersecting the conveying direction of the paper sheet and that alternately light up to independently illuminate a range including at least one end of the paper sheet and one of the two excitation tracks; a plurality of mirrors that condense transmitted light or reflected light from the paper sheets obtained by alternately lighting light sources onto the sensor array, and the plurality of mirrors are oriented in the direction relative to the central axis of the light source. By aligning the sensor array in the same direction and scanning the sensor array in synchronization with the alternate lighting of the front light source, it is possible to alternately and sequentially scan the sheet from both ends toward the center in an isometric manner. A paper sheet pattern reading device characterized by the following features: 2. The plurality of mirrors. a pair of first mirrors that face each of the light sources with the paper sheet interposed therebetween, are arranged substantially parallel to the transport direction and inclined at about 4 degrees with respect to the transport surface; a pair of second mirrors disposed between the first mirrors, perpendicular to the conveying surface and inclined by about 4 degrees with respect to the light incident from the light source through the first mirror; A paper sheet pattern reading device according to claim 1, comprising: