JP2002074448A - Identifying device for paper sheet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an identifying device for paper sheets, having improved identification accuracy by increasing the level of input to an identification calculating part in a block, where light is transmitted through a paper sheets equal to or more than two times. SOLUTION: An amplification factor control part 34 is provided additionally for controlling the amplification factor of an amplifying part 30, for amplifying the detected voltage of a light-receiving element E1 and outputting it to an A/D-converting part 31; when a paper money 1 is switched from a first block S1 to a second block S2, the amplification factor control part 34 increases the amplification factor of the amplifying part 30; when the paper money 1 is switched from the second block S2 to a third block S3, the amplification factor control part 34 performs controls so as to return the amplification factor of the amplifying part 30 to initial state, and the level of input to an identification calculating part 32 during the second block S2 can be raised.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a paper sheet discriminating apparatus for discriminating the authenticity of paper sheets such as banknotes and securities, and more particularly, to a sheet discriminating apparatus provided with a transmitted light amount detection type optical sensor. It is about.

[0002]

2. Description of the Related Art A bill discriminating apparatus, which is an example of a paper sheet discriminating apparatus, is generally provided in a vending machine, a bill changing machine, and the like which can use bills. Such a bill discriminating device detects an optical density pattern along the carrying direction of the printing while carrying the inserted bill along an inverted U-shaped bill conveying path (refer to a symbol T in FIG. 1 and the like). An optical sensor is provided. The authenticity of the bill is determined by comparing the density pattern with the reference pattern.

A conventional light sensor for detecting the amount of transmitted light has a pair of light-emitting elements and a light-receiving element opposed to each other with a banknote transport path interposed therebetween. The density pattern was detected (1 line per sensor). Therefore, in order to detect a plurality of lines of a bill and increase the identification accuracy, it is necessary to arrange a plurality of light emitting / receiving elements, and in this case, there is a problem that an installation space for the optical sensor is increased.

As a technique for improving this point, the present applicant discloses in Japanese Patent Application Laid-Open No. Hei 8-180237 that a plurality of lines such as bills can be detected by a set of light emitting / receiving elements (one sensor 2 (plural) lines). Detection) An optical sensor has been proposed, and the basic form of the optical sensor will be described below with reference to FIGS.
This will be described with reference to FIG.

[0005] FIG. 1 is an explanatory longitudinal sectional view of a bill discriminating apparatus 10.
FIG. 2 is a partial sectional view taken along the line AA of FIG. The bill identifying apparatus 10 includes an optical sensor 20 having two pairs of a light emitting element E1 (, E2) and a light receiving element R1 (, R2). Each of the light emitting elements E1 and E2 is in the first half T of the bill transport path T.
1, that is, the light receiving elements R1 and R2 are disposed so as to correspond to the middle of the portion for transporting the bill 1 upward.
, That is, in the middle of the portion for transporting the bill 1 downward. Accordingly, the light emitting elements E1 and E2 of each set and the light receiving elements R1 and R2 are shifted in the transport direction X in the bill transport path T.

As shown in FIG. 2, the light-emitting elements E1 and E2 and the light-receiving elements R1 and R2 of each set are also displaced from each other in a direction orthogonal to the transport direction X (hereinafter, referred to as "orthogonal direction"). The light emitting elements E1, E2 and the light receiving elements R1, R2 are optically connected by optical fibers F1, F2, respectively. As described above, the light guide paths P1 and P2 between the light emitting elements E1 and E2 and the light receiving elements R1 and R2 substantially formed by the optical fibers F1 and F2 intersect with the bill transport path T at two places, respectively. The crossing points are the light emitting / receiving elements R1, R2, E
1, E2.

FIG. 3 is an explanatory view showing a process of detecting the density pattern of the banknote 1 by a pair of light emitting / receiving elements E1 and R1, and the banknote transport path T is shown horizontally expanded for convenience. In addition, in FIG. 1 to FIG.
1, the light guide path P1 between R1 is the first half T1 of the bill transport path T
Is a second intersection where the light guide path P1 intersects the second half T2 of the bill transport path T.

The tip 1a of the bill 1 inserted from the bill insertion slot 11 (see FIG. 1) and guided to the bill transport path T passes through the first intersection C1 and does not reach the second intersection C2. In one section S1, the banknote 1 moves the light guide path P1 to the first
Cross only once at intersection C1. Therefore, the light receiving element R1 detects the amount of transmitted light that has transmitted the bill 1 only once. The interval in the transport direction X between the first and second intersections C1 and C2 is set to be smaller than the length of the banknote 1 in the longitudinal direction (transport direction X). The light receiving element R1 detects the amount of transmitted light as a voltage value, and the detected voltage is amplified by an amplification unit, and is further amplified by an A / D conversion unit.
After the / D conversion, it is input to the discrimination calculation unit.

Next, the leading end 1a of the bill 1 is moved to the second intersection C2.
, And in the second section S2 in which the rear end 1b of the bill 1 has not reached the first intersection C1, the bill 1 travels the light guide path P1 twice at the first and second intersections C1, C2. Cross.
Therefore, the light receiving element R1 detects the amount of transmitted light that has transmitted the bill 1 twice. Next, the rear end 1b of the banknote 1 is at the first intersection C
1 and has not reached the second intersection C2.
In the section S3, the banknote 1 crosses the light guide path P1 once at the second intersection C2. Therefore, the light receiving element R1 detects the amount of transmitted light that has transmitted the bill once. In addition, the rear end 1b of the bill 1
Passes through the second intersection C2, the detection voltage of the light receiving element R1 becomes the saturation level, and the acquisition of the identification data by the identification calculation unit ends.

In FIGS. 3 and 4, reference numeral L1 denotes a first line of the banknote 1 scanned by the first intersection C1 during the above-described process, and L2 denotes a second line scanned by the second intersection C2. is there. As described above, in the optical sensor 20, two lines of the first and second lines L1 and L2 of the bill 1 can be detected by the pair of light emitting / receiving elements E1 and R1. Therefore, four runs can be detected in combination with the other sets of light emitting / receiving elements E2 and R2. As shown in FIG. 4, the first line L1 is divided into a first section L11 in the front (transport direction X) of the first section S1 and a second section L12 in the rear of the second section S2. You. Also, the second line portion L2
Is a second section L22 in front of the second section S2, which is scanned simultaneously with the second section L12 of the first line portion L1, and a third section L23 in back of the third section S3.
It is divided into and.

[0011]

FIG. 14 is a diagram showing the first to fifth embodiments.
It is a graph which shows the change of the detection voltage of light receiving element E1 in the 3rd section S1, S2, and S3. As shown in this graph, the detected voltage of the second section S2 is lower than that of the first and third sections S1 and S2, and the change is small. This is because, as described above, in the second section S2, the light emitting element R
This is because the light from No. 1 is double transmitted through the banknote 1 and is absorbed and attenuated.

For this reason, the detection signal input to the discrimination calculation unit during the second section S2 has a problem that the amount of change is small and characteristics for discrimination hardly appear.

The present invention has been made in view of this problem, and an object thereof is to increase the input level to a discrimination calculation unit in a section where light passes through a paper sheet twice or more to improve discrimination accuracy. It is an object of the present invention to provide a paper sheet identification device capable of performing such operations.

[0014]

According to a first aspect of the present invention, there is provided a light emitting element for emitting light to a sheet conveyed along a sheet conveying path, and a light emitting element for emitting light from the light emitting element. And a light receiving element for detecting the amount of transmitted light transmitted through the paper sheet, and optically communicating between the light emitting element and the light receiving element,
A light guide path that intersects the paper transport path at two or more locations, and an identification operation unit that determines the authenticity of the bill based on a detection signal from the light receiving element, and a paper transport path of the light guide path. At least two intersections are arranged to be shifted in the transport direction of the paper sheet, and the light receiving element emits light in a section where the paper sheet crosses two or more intersections of the light guide path. In a bill validator that detects the amount of transmitted light that has passed through a paper sheet two or more times,
An input level raising means for raising the input level of the detection signal to the discrimination calculation unit in the section where two or more intersections cross is provided.

According to the present invention, the input level of the detection signal of the amount of transmitted light input from the light receiving element to the discriminating operation section in the two or more intersecting sections where the light from the light emitting element passes through the paper sheet at least twice. Is raised by the input level raising means, so that the amount of change in the identification data in the two or more intersection crossing sections can be enlarged, and the characteristics for identification can be made remarkable.

[0016] Specific examples of paper sheets include banknotes, securities, gift certificates and the like.

According to a second aspect of the present invention, a light emitting element for emitting light to a sheet conveyed along a sheet conveying path, and a light receiving element for detecting the amount of light emitted from the light emitting element and transmitted through the sheet. The optical communication path between the element, the light emitting element and the light receiving element, and the light guide path intersecting the paper sheet transport path at two points, and identification for judging the authenticity of the bill based on the detection signal from the light receiving element. The light guide path includes a calculation unit, and each intersection of the light guide path and the paper sheet transport path is disposed so as to be shifted in the paper sheet transport direction. Detects the amount of transmitted light that has transmitted through the paper sheet once at one crossing section that crosses the part, and transmitted light twice through the paper sheet at the two crossing section that crosses two intersections In a bill validator that detects the amount of transmitted light, a detection signal to a discrimination calculation unit in a section crossing two intersections It is characterized by providing an input level pulling means pulling the input level.

According to the present invention, the input level of the detection signal of the amount of transmitted light input from the light receiving element to the discriminating operation section is set in the crossing section where the light from the light emitting element passes through the paper sheet twice. By raising the level to the same level as the crossing section at one intersection by the input level raising means, the amount of change in the identification data in the crossing section at the two intersections can be expanded, and the feature for identification can be made remarkable.

According to a third aspect of the present invention, in the first or second aspect of the present invention, the input level raising means switches a signal amplification factor of an amplification section provided between the light receiving element and the identification calculation section. It is characterized by having. According to the present invention, it is possible to increase the input level to the discrimination calculation unit by increasing the signal amplification factor of the amplification unit in the section where two (or more) intersections cross.

According to a fourth aspect of the present invention, in the first or second aspect of the present invention, the input level raising means includes an A / D converter of an A / D converter provided between the light receiving element and the identification operation unit.
/ D conversion rate is switched. According to the present invention, by amplifying the conversion value of the A / D converter in the two (or more) crossing sections, the input level to the discrimination calculation unit can be raised.

According to a fifth aspect of the present invention, in the first or second aspect of the present invention, the input level raising means switches a light emission amount of the light emitting element. According to the present invention, it is possible to increase the input level to the discrimination calculation unit by increasing the light emission amount of the light emitting element in the crossing section of two (or more) intersections.

[0022]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of a bill discriminating apparatus according to a first embodiment of the present invention; FIG. Will be described based on FIGS. 1 to 5. 1 is a vertical cross-sectional explanatory view of the bill validator, FIG. 2 is a partial cross-sectional explanatory view taken along the line AA of FIG. 1, FIG. 3 is a diagram illustrating a density pattern detection process of the banknote, and FIG. Explanation diagram, FIG.
FIG. 2 is a block diagram schematically showing a control system of the bill validator.

Referring to FIG. 1, a bill discriminating apparatus 10 includes a bill insertion slot 11 and a bill transport mechanism 12 for transporting a bill 1 inserted from the bill insertion slot 11 along a reverse U-shaped bill transport path T. And an optical sensor 20 for detecting the density pattern from the transmitted light amount of light emitted to the banknote 1 being transported to the banknote transport path T.
And a bill storage unit 13 for storing the bills 1 which are determined to be authentic by the later-described identification calculation unit 32 (see FIG. 5 and the like) and used for use. Note that the bill transport mechanism 12
Consists of a belt 12a (see FIG. 2), a roller 12b, a motor 12C (see FIG. 5) and the like.

The configuration and arrangement of the optical sensor 20 are as described in the background art. That is, the optical sensor 20 includes a pair of light emitting elements E1 (, E2) and light receiving elements R1 (, R2).
(See FIG. 2), and each light emitting element E1, E2 is provided in the middle of the first half T1 of the bill transport path T, and each light receiving element R1, R2
Are arranged correspondingly in the middle of the second half T2 of the bill transport path T. Accordingly, the light emitting elements E1 and E2 of each set and the light receiving elements R1 and R2 are shifted in the transport direction X in the bill transport path T. The light emitting elements R1 and R2 of each set and the light receiving elements E1 and E2 are also displaced in the orthogonal direction (see FIG. 2). Further, the light guiding paths P1 and P2 substantially formed by the optical fibers F1 and F2 between the light emitting elements E1 and E2 and the light receiving elements R1 and R2 intersect the bill conveying path T at two places, respectively. A first intersection where the guide path P1 intersects the first half T1 of the bill transport path T is indicated by a symbol C1, and a second intersection that intersects the second half T2 is indicated by a symbol C2. The light emitting elements E1 and E2 are LEDs
For example, a PD or the like can be used as the light receiving elements R1 and R2. In addition, the light guide paths P1 and P2 can be formed by an optical lens, a prism, or the like in addition to the optical fiber.

In the optical sensor 20 described above, the first line L1 and the second line L1 of the banknote 1 are generated by the pair of light emitting / receiving elements R1 and E1 as described in the background section.
2 (see FIGS. 3 and 4), the density pattern can be detected along two lines.

That is, referring to FIG. 3, the leading end 1a of the bill 1 inserted from the bill insertion slot 11 and guided to the bill transport path T.
In the first section (one crossing section crossing section) S1 through which the banknote 1 passes through the first crossing section C1 and does not reach the second crossing section C2, the banknote 1 passes through the light guide path P1 at the first crossing section C1. The light receiving element R1 detects the amount of transmitted light that has passed through the banknote 1 only once (first section detection step). In this step, the line L1 of the bill 1 is scanned by scanning the first intersection C1.
Is detected in the first section L11 (see FIG. 4).

Next, the leading end 1a of the bill 1 is moved to the second intersection C2.
, And the rear end 1b of the bill 1 does not reach the first intersection C1 (second (or more) intersection crossing section)
In S2, the bill 1 moves the light guide path P1 through the first and second light guide paths.
It crosses twice at the intersections C1 and C2, and the light receiving element R1 is banknote 1.
Is detected twice (a second section detection step). In this step, by scanning the first and second intersections C1 and C2, the second section L1 in the line L1 of the banknote 1
2 (see FIG. 4) and the second section L22 in the line L2
Is detected.

Next, the rear end 1b of the bill 1 is moved to the first intersection C1.
, And in the third section (one crossing section crossing section) S3 which has not reached the second crossing section C2, the banknote 1 crosses the light guide path P1 once at the second crossing section C2, and the light receiving element R
1 detects the amount of transmitted light that has transmitted the bill once (third section detection step). In this step, by scanning the second intersection C2, the third section L23 (see FIG.
) Is detected. As described above, the optical sensor 20
The two sets of first and second lines L1 and L2 of the banknote 1 can be detected by a set of light emitting / receiving elements R1 and E1,
Four lines can be detected in combination with the other sets of light emitting / receiving elements E2 and R2.

In each of the above steps, the light receiving element R1
Detects the amount of transmitted light as a voltage value, and the detected voltage is amplified by an amplifier 30 as shown in FIG.
After being A / D-converted by the conversion unit 31, it is input to the identification calculation unit 32. The identification calculation unit 32 determines the authenticity of the bill 1 by comparing the input identification data with reference data stored in a reference data storage unit (not shown),
An authenticity judgment signal or an improper judgment signal is output to the control unit 33. When receiving the authenticity determination signal, the control unit 33 performs a predetermined bill use operation such as a merchandise selling operation, and when receiving the improper determination signal, reversely rotates the motor 12c of the bill transport mechanism 12 to perform the bill 1 operation. Is returned from the bill insertion slot 11.

The detection voltage of the light receiving element R2 in the second section S2 is equal to the detection voltage of the first and third sections S1 and S3 because the light is absorbed and attenuated by the double transmission of the bill 1. It is reduced in comparison (see FIG. 14). Therefore, during the second section detecting step, the input level to the discrimination calculation unit 32 is low, and it is difficult for features for discrimination to appear. The following first to third embodiments solve this point.

FIGS. 6 to 8 relate to a first embodiment of a bill validating apparatus. FIG. 6 is an explanatory view of the main structure of the first embodiment.
FIG. 7 is a flowchart schematically showing a density pattern detection process according to the first embodiment, and FIG. 8 is a first to third sections S1,
9 is a graph showing changes in the output signal of the amplification unit 30 in S2 and S3. In this embodiment, the same parts as those of the above-described banknote recognition device 10 are denoted by the same reference numerals, and description thereof is omitted (the same applies to the second and third embodiments). In the present embodiment, the control unit 33a serves as a means for raising the input level to the identification calculation unit 32 during the second section S2.
The amplification factor adjustment unit 34 that adjusts the signal amplification factor of the amplification unit 30 based on the instruction is provided. Hereinafter, the density pattern detection process according to the present embodiment will be described with reference to the flowchart in FIG.

First, the first section S1 of the bill 1 guided to the bill transport path T from the bill insertion slot 11 is detected in the same manner as described above (# 1). Next, the bill 1 is moved to the first section S
1 and enters the second section S2, since the transmission of light to the banknote 1 becomes once or twice, the detection voltage of the light receiving element R2 rapidly decreases, and accordingly, the output of the amplifier 30 also increases. It drops sharply. When the output value of the amplifying unit 20 thus reduced falls below the predetermined reference value 1 (see FIG. 8) (# 2), the control unit 33a determines that the banknote 1 has been switched from the first section to the second section S2. Then, an amplification factor up signal is output to the amplification factor adjusting section 34 (# 3). Thereby, the amplification factor adjusting unit 34 raises the signal amplification factor of the amplification unit 30 by a predetermined ratio,
The output level of the amplification unit 30 is set to the same level as that of the first section S1 (see FIG. 8). Thus, the detection of the second section S2 is performed in a state where the amplification factor of the amplification unit 30 is increased (♯
4). Therefore, the input level to the discrimination calculation unit 32 during the second section S2 is equivalent to that of the first section S1. As the reference value 1, a voltage value that cannot be reached in the first section S1 and is always reached (below) in the second section S2 is selected.

Next, when the bill 1 enters the third section S3 from the second section S2, since the transmission of light to the bill 1 returns from twice to once, the detection voltage of the light receiving element R1 sharply increases. As a result, the output of the amplification unit 30 whose amplification factor has been raised sharply increases (see FIG. 8). When the output value of the amplifier 30 exceeds a predetermined reference value 2 (値
5), the controller 33a determines that the bill 1 is in the second section to the third section S
3, and outputs a gain down signal to the gain adjuster 34 (# 6). Thus, the amplification factor of the amplification unit 30 is returned to the initial state, and the third section S3 is detected in the same manner as described above (# 7). In addition, reference value 2
In the state where the amplification factor is increased, the second
A voltage value that cannot be reached in the section S2 and is always reached (exceeded) in the third section S3 is selected.

In the above steps, the output signal of the amplifier 30 changes as shown in the graph of FIG. Therefore, the amount of change in the second section S2 is as large as in the first and third sections S1 and S3, and the features for identification in the second section S2 are also clear. In the above process, the switching from the first section S1 to the second section S2 and the switching from the second section S2 to the third section S3 are determined from the change in the voltage value. In addition, for example, the rotary encoder of the motor 12C (see FIG. (Not shown), the conveying distance of the bill 1 is calculated by counting the pulses, and the judgment can be made based on this. Note that the section switching detection by this control unit is substantially the same in the second and third embodiments described later.

FIGS. 9 to 11 relate to a second embodiment of the bill validator. FIG. 9 is an explanatory view of the main structure of the second embodiment, and FIGS. 10 and 11 show A / D conversion in the second embodiment. It is explanatory drawing of a method. In the present embodiment, the second section S2
A conversion value adjusting unit 35 for adjusting the A / D conversion rate of the A / D conversion unit 31 based on a command from the control unit 33b is provided as means for raising the input level to the discrimination calculation unit 32. That is, when the banknote 1 is switched from the first section S1 to the second section S2, the control section 33b outputs a conversion value up signal to the conversion value adjustment section 35. As a result, the conversion value adjustment unit 35 sets the A / D conversion unit 31
Amplify the D-converted value twice.

Referring to FIG. 10, reference numerals v1 to v10 represent
In the A / D converter 31 in the second section S2, the A / D conversion when the A / D conversion is performed in the same manner as in the first and third sections S1 and S3.
This is a D-converted value. In this case, the sampling interval of the converted value from the input signal (hereinafter referred to as “normal sampling interval I”) is 2 seconds, during which the bill 1 moves 2 mm on the bill transport path T. In the present embodiment, as shown in FIG. 11, the number of times of sampling in the second section S2 is increased to eight times per normal sampling interval I, and the eight sampling values vd are averaged for each normal sampling interval I. By doubling the value, the A / D converted values V1 to V10 are obtained, and the identification data thus amplified is output to the identification operation unit 32.
Is output to At this time, the conversion value adjusting unit 35 accumulates each sampling value vd for each normal sampling interval I while counting the number of samplings, and calculates the accumulated value as 1 / (1/8) of the number of samplings (8) per the normal sampling interval I. By dividing by 2-4, the above A
The / D conversion values V1 to V12 are sequentially calculated. In addition, in the above example, an easy-to-understand numerical value is given, but the number of times of sampling, the amplification factor, and the like can be set as desired.

Subsequently, the bill 1 is moved from the second section S2 to the third section S2.
When switching to the section S3, the control unit 33b outputs a converted value down signal to the converted value adjusting unit 35, whereby the A
The output level from the / D converter 31 is returned to the same state as in the first section S1.

FIG. 12 is an explanatory view of a main structure of a bill discriminating apparatus according to a third embodiment. In the present embodiment, a light emission amount adjustment unit 36 that adjusts the light emission amount of the light emitting element E1 based on a command from the control unit 33c is provided as a means for raising the input level to the identification calculation unit 32 during the second section S2. . still,
Reference numeral 37 denotes a light-emitting power supply unit serving as a power supply for the light-emitting element E1. The light emission amount adjusting section 36 operates as follows. That is, when the banknote 1 is switched from the first section S1 to the second section S2, the control section 33c outputs a light emission amount up signal to the light emission amount adjustment section 36. As a result, the light emission amount adjustment unit 36 raises the light emission amount of the light emitting element E1 via the light emission power supply unit 37, and sets the transmitted light amount of the banknote 1 to the same level as the first section S1. Therefore, the input level to the discrimination calculation unit 32 during the second section S2 is raised. When the bill 1 is switched from the second section S2 to the third section S3, the control section 33c outputs a light emission amount down signal to the light emission amount adjustment section 36, whereby the output level of the light emitting element E1 becomes the first section S1. Is returned to the same state as.

In each of the above embodiments, a basic example has been given in which the number of times of light transmission to the banknote 1 changes from once to twice to once through the first to third sections S1, S2, and S3. However, the present invention is not limited to this. For example, FIG.
In the optical sensor shown in the cross-sectional partial explanatory diagram (the same cross-sectional portion as in FIG. 2), the number of times light is transmitted through the bill 1 changes from twice to four times to twice. That is, this optical sensor has a set of a light emitting element E3 and a light receiving element R3.
Both 3 and R3 are arranged in the middle of the first half T1 of the banknote transport path T without being shifted in the transport direction X and shifted only in the orthogonal direction. The light guide path P3 between the light emitting element E and the light receiving element R3 is composed of three optical fibers F3 and F3.
4 and F5, the first half T1 of the bill transport path T intersects at two intersections C3, C4, and the second half T2 of the bill transport path T intersects at two intersections C5, C6. Have been. The intersections C5 and C6 are in the transport direction X
At the same position.

In this optical sensor, the bill 1 entering the bill transport path T first crosses the intersections C3 and C4, where light passes through the bill 1 twice. Banknote 1 then crosses C3,
In addition to C4, it also crosses the intersections C5 and C6, where light passes through the bill 1 four times. Banknote 1 then crosses C3, C4
And crosses only the intersections C5 and C6, where the light passes through the bill 1 twice. In such a case, the input level to the discrimination calculation unit 32 in the section where light is transmitted four times is raised to the same level as the section where light is transmitted twice by the control of any of the above-described first to third embodiments. To do.

[0041]

As described above in detail, according to the first aspect of the present invention, the detection signal of the transmitted light amount transmitted through the paper sheet twice or more in the crossing section of the two or more intersections is input to the identification calculation unit. By raising the level by the input level raising means, it is possible to increase the amount of change of the identification data in the two or more intersection crossing sections, make the feature for identification remarkable, and improve the identification accuracy.

According to the second aspect of the present invention, the input level of the detection signal of the transmitted light amount transmitted through the paper sheet twice in the crossing section of the two intersections to the discrimination calculation unit is increased by one by the input level raising means. By raising the level to the same level as the section crossing section, the amount of change in the identification data in the two-crossing section crossing section can be expanded, the characteristics for identification can be remarkable, and the identification accuracy can be improved.

According to the third aspect of the present invention, the output level to the discriminating operation unit can be increased by increasing the signal amplification factor of the amplifying unit in the two (or more) crossing sections.

According to the fourth aspect of the present invention, by changing the A / D conversion rate of the A / D conversion section in the two (or more) crossing sections, the input level to the discrimination calculation section can be raised. .

According to the fifth aspect of the present invention, it is possible to increase the input level to the discrimination calculation unit by increasing the light emission amount of the light emitting element in the section (two or more) crossing the intersection.

[Brief description of the drawings]

FIG. 1 is an explanatory longitudinal sectional view of a bill validator;

FIG. 2 is a partial sectional view taken along the line AA of FIG. 1;

FIG. 3 is an explanatory diagram of a banknote density pattern detection process.

FIG. 4 is an explanatory diagram showing a density pattern detection line of a banknote;

FIG. 5 is a block diagram schematically showing a control system of the bill validator.

FIG. 6 is an explanatory diagram of a main configuration of the first embodiment.

FIG. 7 is a flowchart schematically showing a density pattern detection step according to the first embodiment;

FIG. 8 is a graph showing a change in an output signal of the amplification unit.

FIG. 9 is an explanatory diagram of a main configuration of a second embodiment.

FIG. 10 is an explanatory diagram of an A / D conversion method according to a second embodiment.

FIG. 11 is an explanatory diagram of an A / D conversion method according to the second embodiment.

FIG. 12 is an explanatory diagram of a main configuration of a third embodiment.

FIG. 13 is a sectional partial explanatory view similar to FIG. 2, showing another embodiment of the optical sensor;

FIG. 14 is a graph showing a change in detection voltage in a conventional light receiving element.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... banknote, 10 ... banknote identification device, 12 ... banknote conveyance mechanism,
20 ... optical sensor, 30 ... amplifying unit, 31 ... A / D conversion unit,
32: identification operation unit, 33, 33a, 33b, 33c: control unit, 34: amplification factor adjustment unit, 35: conversion value adjustment unit, 36
... Light emission amount adjustment unit T ... Bill transport path, E1, E2, E3 ... Light emitting element, R1,
R2, R3: light receiving element, P1, P2, P3: light guide path,
C1: first intersection, C2: second intersection, S1: first section, S2: second section, S3: third section

Claims (5)

[Claims] 1. A light emitting element that emits light to a sheet conveyed along a sheet conveying path, a light receiving element that detects the amount of light emitted from the light emitting element and transmitted through the sheet, and a light emitting element.
Optical communication between the light receiving elements, and a light guide path that intersects the paper transport path at two or more locations, and an identification calculation unit that determines the authenticity of the bill based on the detection signal from the light receiving element At least two intersections between the light guide path and the sheet transport path,
The light receiving element is arranged so as to be shifted in the transport direction of the paper sheet, and light is transmitted through the paper sheet at least twice in a section where the paper sheet crosses two or more intersections of the light guide path. A bill discriminating apparatus for detecting the amount of transmitted light, characterized by further comprising an input level increasing means for increasing an input level of a detection signal to an identification calculating section in a section where two or more intersecting portions cross. 2. A light emitting element which emits light to a sheet conveyed along a sheet conveying path, a light receiving element which detects the amount of light emitted from the light emitting element and transmitted through the sheet, and a light emitting element.
Optically communicating between the light receiving elements, and a light guide path that intersects the paper sheet transport path at two locations, and an identification operation unit that determines the authenticity of the bill based on a detection signal from the light receiving element, Each intersection of the light guide path and the paper sheet transport path is disposed so as to be shifted in the paper sheet transport direction, and the light receiving element is provided at one intersection where the paper sheet crosses one intersection of the light guide path. A banknote that detects the amount of transmitted light that has passed through a sheet once in a crossing section and detects the amount of transmitted light that has passed through a sheet twice in a two-crossing section that crosses two intersections. An identification device, comprising: an input level increasing means for increasing an input level of a detection signal to an identification operation section in a section where two intersections are crossed. 3. The paper sheet according to claim 1, wherein the input level raising unit switches a signal amplification factor of an amplification unit provided between the light receiving element and the identification calculation unit. Identification device. 4. An A / D converter of an A / D converter provided between a light receiving element and an identification operation unit, wherein the input level raising means is provided.
3. The paper sheet identification device according to claim 1, wherein the D conversion ratio is switched. 5. The paper sheet identification device according to claim 1, wherein said input level raising means switches a light emission amount of a light emitting element.