JPS6337494A - Transmission/reflection sensor - Google Patents

Abstract

(57) [Abstract] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Summary] To enable a sensor for reading paper sheets such as banknotes to obtain the transmitted component and reflected component of light irradiated to the paper sheet that passes through the medium from the entire surface of the medium.

Nine light-emitting elements and light-receiving elements are arranged at four points on the X-shaped optical axis,
The transmitted and reflected components are separated by synchronous control.

[Industrial application field]

The present invention is a transmission/reflection sensor, particularly a sensor for reading filter paper sheets used in, for example, bill validators and their development systems, which can eliminate the effects of vertical movement of the paper sheets being read with a simple configuration. The present invention relates to a transmissive reflection sensor.

Automatic deposit machines, automatic ticket vending machines, etc. require identification of banknotes inserted. This type of banknote validator uses various standard patterns of banknotes collected in advance.

By comparing the patterns read from the inserted banknotes, the type and authenticity of the two banknotes are determined. Optical sensors are generally used to create the reference pattern and read banknotes for identification, but it is desirable to use a sensor that can obtain uniform pattern data that is as unaffected by the condition of the banknotes as possible. .

[Conventional technology]

FIG. 8 shows an example of a bill validator.

In the figure, 50 is a banknote to be discriminated, 51 is a banknote reading unit equipped with an optical sensor, 52 is a reference pattern database in which standard reference patterns collected in advance are stored, 5
3 represents a discrimination unit that discriminates the type and authenticity of banknotes.

When the banknote 50 is read by the banknote reading unit 51.

Both the transmitted component and the reflected component of the light irradiated onto the banknote 50 are acquired as pattern data. Then, the discrimination section 53 discriminates one banknote by comparing the pattern data with a reference pattern.

In the conventional sensor used for the two banknote reading section 51.

One for detecting the transmitted component and one for detecting the two reflected components are provided separately, and a plurality of sensors are individually arranged.

[Problem that the invention seeks to solve]

Conventional sensors have a problem in that the number of parts is large and each sensor is individually arranged, making wiring and control complicated. Further, there was a problem in that if the paper sheets moved up and down during passage, variations in the transmitted components etc. occurred.

SUMMARY OF THE INVENTION The present invention aims to solve the above-mentioned problems and provides a transmissive/reflective sensor that has a small number of parts and is capable of acquiring transmitted and reflected components through simple control.

[Means for solving problems]

FIG. 1 shows an example of the basic configuration of the present invention.

In FIG. 1, 10-1. ...10-i, ... are optical sensor units, '11-1.11-2 are LED drivers, 12-1.12-2 are current-voltage converters, 13-
1 to 13-4 are amplifiers, 20 is a sensor block, 2
1 is a glass plate, 22 is a printed board, LEDI, LED2
is a light emitting diode, PDl and PO2 are photodiodes + SI, and 51 is a switch.

Each optical sensor unit 10-i is constituted by two transmissive-reflective sensors according to the present invention, each having an LED L LED2.
, PDl, and PO2.

These light-emitting elements and light-receiving elements are arranged in an array on, for example, the print 22.

FIG. 1(B) is a sectional view of a sensor block in one optical sensor unit 10-i.

Each LEDI, LED2. The PDI and PD2 are respectively arranged at four points on the X-shaped optical axis as shown.

The paper sheet to be inspected passes between two glass plates 21, and the light emitted by the LEDI is reflected.

The transmitted light is detected by PO2. In addition, the reflected light of the light emitted by LED2 is
It is detected by PO2, and the transmitted light at this time is PDI
detected by.

That is, when the LED driver 11-1 shown in FIG. 1(A) drives the LEDI, the PDI and PO2 generate currents corresponding to the reflected light and transmitted light. Current voltage converter 12-1.12-2.

Each converts that current into voltage. LED driver 1
The same applies to 1-2. However, the signals T, , T2 for operating the LED drivers 11-1, 11-2 are sent in a two-time division manner.

Switches 51 to S4 are connected to signals T3. By controlling opening and closing by T, voltages VB1 to V14, etc. amplified by amplifiers 13-1 to 13-4 are obtained. These voltages correspond to the strength of the passing light and reflected light on the front side and back side of the paper sheet being inspected.

[Effect]

In each optical sensor unit, LEDI, LED2 .
PDI and PO2 are placed at four points on the X-shaped optical axis.
Since LEDI and LED2 are driven in a time-divisional manner, the reflected light and transmitted light from the front side to be inspected and the reflected light and transmitted light from the back side can be obtained separately. become.

For example, if a plurality of optical sensor units are arranged in an array on the printed circuit board 22 as shown in FIG. 1, the signals T1 to T4 for synchronous control will be as follows.

Since it can be commonly supplied to each optical sensor unit via the printed board 22, processing related to wiring and control is simplified, and data can be acquired from the entire surface of the medium.

〔Example〕

FIG. 2 is a timing chart of one embodiment of the present invention.

FIG. 3 is a mechanical diagram of a paper sheet discrimination section using the present invention.

Fig. 4 is an explanatory diagram of the sensor array of the discrimination section shown in Fig. 3, Fig. 5 is an example of a sample grid of paper sheets to be inspected, Fig. 6 is an explanatory diagram of sample timing, and Fig. 7 is an illustration of the present invention. 3 shows a configuration example of a control unit according to an embodiment.

As shown in FIG. 2, the signal T1 driving the LEDI is
Signal T2 that repeats 0FF10N and drives LED2
In contrast, repeats 0N10FF. switch 5
1 and 51 is turned ON after a predetermined sensor output rise compensation time t with respect to the signal T1.

The same applies to signal T4 as well as signal T2.

As a result, when the signals Tz and 'ra are ON.

The intensity of the reflected light from LED2 to PD2 is obtained as the output ■1□, and the intensity of the reflected light from LED2 to PD2 is obtained as the output V i 3.
The intensity of the transmitted light to I is obtained. Moreover, the signal T + ,
As output Vil when T3 is ON.

The intensity of transmitted light from LEDI to PD2 can be obtained.

Assuming the output V=4, the intensity of the reflected light from the LEDI to the PDI is obtained.

FIG. 3 shows the mechanism of the discriminating section of a sheet discriminating machine in which two transmissive-reflective sensor arrays according to the present invention are used. In FIG. 3, 30 is a roller for conveying paper sheets, 31 is a conveyance path guide plate, 32 is a transmission/reflection sensor, 33 is a paper sheet intrusion detection sensor, and 34 is a passage detection sensor.

The intrusion detection sensor 33 is R+ shown in FIG. 3(B).

The 1st passage detection sensor 34 is placed at the R2 position.

It is placed at position R3,R. The optical sensor units 10-1 to 10-n are arranged in an array at right angles to the traveling direction of the two sheets. Figure 4 is.

The transmissive-reflective sensors arranged in an array are shown.

What is the data area corresponding to the paper sheet to be inspected?

As shown in FIG. 5, it is divided into nxm areas.

The area lined up on the horizontal axis of each grid corresponds to the position of each optical sensor unit 10-i. The data in the area lined up on the vertical axis is obtained corresponding to the transport timings from 1 to m.

FIG. 6 shows sample timing for one optical sensor unit. The deviation of the intrusion detection signal due to R,, R, indicates the amount of skew when one sheet is inserted diagonally. Data is acquired by the transmission/reflection sensor 32 shown in FIG. 3 using m timing clocks, and the data is used for identification.

The hardware configuration of a control section in a paper sheet validator according to an embodiment of the present invention is as shown in FIG. 7, for example. In FIG. 7, 40 is an analog multiplexer, 41 is an A/D inverter, and 42 is a central processing unit (C
PU), 43 is memory, 44 is external interface, 4
5 represents a control unit lotus line, and 46 represents an input port.

The CPU 42 controls the entry and passage of paper sheets through the input port 46.
Detected via. 1, each input to the analog multiplexer 40, is the output of the j-th amplifier 13-j in the i-th optical sensor unit 10-i shown in FIG. The CPU 42 inputs them as digital values via the A/D converter 41.

Thereby, the output voltages Vk2 to V*4 (k=l to n: Unisoto number) in each sample grid shown in FIG. 5 can be obtained. The value of each sample grid is expressed as follows.

PnbcCa: Unisotho number (1-n).

b = timing number (1 to m).

C: Sensor output number (1 to 4)] For example, the values of the diagonally shaded sample grids shown in FIG. 5 are P4□1 to P4□4. The intensity of transmitted light from the front side to the back side P. , and the intensity of transmitted light from the back side to the front side P.

3 should be equal to 1 in normal cases, but when the paper sheet moves up and down between the conveyance path guide plates, the value changes depending on the effect. Therefore, the CPU 42 calculates the average value of the two passing components in a linear manner.

PabI=(Pabl+Pabz)/2 In the subsequent discrimination, the transmitted component is the new P which is the average value.
Use only abl. Due to this.

The effects of vertical movement of paper sheets, etc. can be removed.

〔Effect of the invention〕

As explained above, according to the present invention, it is possible to realize a sensor that can acquire transmitted and reflected components with a small number of parts overall (and with simple control), and which can be read by the vertical movement of filter paper sheets. Since the effects of the above can be easily removed, it becomes possible to obtain effective data in the creation and identification of reference patterns.

[Brief explanation of drawings]

Fig. 1 is an example of the basic configuration of the present invention, Fig. 2 is a timing chart of an embodiment of the present invention, Fig. 3 is a mechanical diagram of a paper sheet discrimination section using the present invention, and Fig. 4 is similar to Fig. 3. Fig. 5 is an example of a sample grid of paper sheets to be inspected; Fig. 6 is an explanatory diagram of sample timing;
The figure shows an example of the configuration of a control section according to an embodiment of the present invention, and FIG. 8 shows an example of a bill validator. In the figure, 10-1. ...10-1+ ... is an optical sensor unit 11-1.11-2 is an LED driver. 12-1, 12-2 are current-voltage converters, 13-1 to 13-4 are amplifiers, and 20 is a sensor block. 21 is a glass plate, 22 is a printed board, and LEDI. LED2 is a light emitting diode, PDI and PD2 are photodiodes, and S1 to S4 are switches. Patent Applicant: Fujitsu Limited Patent Attorney, Yoshiyoshi Ogasawara No. 1!21 ヱヱ・f しょう だ f 1 り す 4 # ii 时 4 蓼蓼Included? = The Seven Shigoshi Rikisen is working hard! 4mi〉7′ Brown 5 mouths

Claims (1)

[Claims] A sensor for detecting transmitted light and reflected light of light irradiated onto passing paper sheets, comprising a first and a second light emitting element and a first light emitting element at four points on an X-shaped optical axis.
and a second light-receiving element, the first and second light-receiving elements blink alternately under synchronous control.
A transmission/reflection sensor comprising means (5_1 to 5_4) for receiving the light emitted by the light emitting element by the first and second light receiving elements and separating the transmitted component and the reflected component.