JP7750591B1 - Banknote validator - Google Patents

Abstract

A bill validator capable of accurately detecting wet bills while reducing costs and reject rates is provided.
[Solution] A banknote identification device 1 comprising an insertion slot 2 into which banknotes 101 are inserted, a transport path through which the banknotes 101 are transported, an identification sensor 5 for identifying the banknotes 101, and a control unit 9, wherein the identification sensor 5 has an optical sensor 51 that sequentially detects the amount of light transmitted through the banknotes 101 being transported in the transport path 3, and when the maximum amount of light transmitted through the banknote 101 detected by the optical sensor 51 becomes equal to or greater than a predetermined judgment threshold, the control unit 9 determines that the banknote 101 is a wet banknote and returns the banknote 101 from the insertion slot 2.
[Selected Figure] Figure 6

Description

The present invention relates to a banknote validator.

A banknote validator is a device that identifies banknotes, and is often connected to or installed in vending machines, currency exchange machines, settlement machines, ticket vending machines, POS registers, service equipment, etc.

A banknote validator typically comprises a banknote insertion slot, a banknote transport path, a recognition sensor, and a banknote storage unit. The banknote validator transports banknotes inserted into the banknote insertion slot along the banknote transport path, stores banknotes determined to be genuine based on the output of the recognition sensor in the banknote storage unit, and returns banknotes determined to be counterfeit from the banknote insertion slot.

When wet banknotes are inserted into such a banknote validator, the wet banknotes can become stuck in the banknote transport passage, increasing the likelihood that the banknote validator will become inoperable. This is because wet banknotes tend to stick to the walls of the banknote transport passage. Wet banknotes also have reduced strength and elasticity, making them more susceptible to tearing and wrinkling. This also makes wet banknotes more likely to become stuck in the banknote transport passage. For this reason, a mechanism has been devised to detect wet banknotes and return any detected wet banknotes.

For example, Patent Document 1 describes a banknote identification device that includes a detection means for detecting the impedance of a banknote being transported along a banknote transport path, and returns the banknote when the impedance detected by the detection means is equal to or less than a predetermined value.

Patent document 2 also describes a bill validator that detects wet bills using an entrance sensor that detects the insertion of bills.

Patent No. 4622694 JP 2016-4389 A

The technology in Patent Document 1 requires the provision of special detection means for detecting the impedance of banknotes, which increases the number of parts, resulting in problems such as increased costs and higher defect rates.

The technology in Patent Document 2 uses an entrance sensor to detect wet banknotes, and entrance sensors typically use phototransistors. While phototransistors can quickly detect the presence or absence of light, they have difficulty detecting weak light, making it difficult to detect the difference between normal banknotes and wet banknotes. To detect this difference, it is appropriate to use a photodiode and an amplifier circuit that amplifies the output of the photodiode as the entrance sensor. In fact, Patent Document 2 describes using a photodiode and an amplifier circuit as the entrance sensor. However, a banknote validator configured in this way requires an amplifier circuit, switching circuit, etc., which increases the number of parts, resulting in problems such as increased costs and higher defect rates.

In view of the above, an object of the present invention is to provide a banknote validator that reduces costs and reject rates. Another object of the present invention is to provide a banknote validator that can accurately detect wet banknotes.

To solve the above problem, the banknote recognition device of the present invention is a banknote recognition device comprising an insertion slot into which banknotes are inserted, a transport path through which the banknotes are transported, an identification sensor that identifies the banknotes, and a control unit. The identification sensor has an optical sensor that sequentially detects the amount of light transmitted through the banknotes being transported in the transport path, and the control unit determines that the banknote is a wet banknote when the maximum amount of light transmitted through the banknote detected by the optical sensor exceeds a predetermined judgment threshold, and returns the banknote from the insertion slot.

The banknote validator may be capable of accepting two or more types of banknotes, and the control unit may, when the optical sensor detects the amount of light transmitted through the banknote up to a position a predetermined distance from the leading edge of the banknote, tentatively determine the type of the banknote based on the data on the amount of light transmitted through the banknote detected up to that point, and update the value of the predetermined determination threshold value depending on the result of that determination.

The banknote recognition device may be configured such that a judgment reference value for determining whether a banknote is wet is set for each banknote type, the judgment reference value for the banknote type with the largest judgment reference value is set as the predetermined judgment threshold, and if the judgment reference value for the banknote type determined in the provisional judgment of the banknote type is smaller than the predetermined judgment threshold, the value of the predetermined judgment threshold is changed to the judgment reference value for the banknote type determined in the provisional judgment of the banknote type.

The predetermined distance may be set so that the rear end of the banknote protrudes from the insertion slot when the optical sensor detects the amount of light transmitted through the banknote up to a position at the predetermined distance from the leading end of the banknote.

The banknote validator of the present invention makes it possible to reduce costs and reject rates. Furthermore, the banknote validator of the present invention makes it possible to accurately detect wet banknotes.

1 is a vertical cross-sectional view showing the configuration of a banknote validator 1 of the present embodiment. FIG. 2 is a vertical cross-sectional view showing the configuration of the vicinity of the identification sensor 5 of the banknote identification device 1 of the present embodiment. FIG. 2 is a block diagram showing the configuration of a control unit 9 of the banknote recognition device 1 of the present embodiment. 10 is a diagram showing an example of the amount of light transmitted through a banknote 101 detected by an optical sensor 51 of the identification sensor 5. FIG. This is a vertical cross-sectional view showing the position of the banknote 101 in the banknote identification device 1 at the time when the optical sensor 51 of the identification sensor 5 detects the amount of light transmitted through the banknote 101 up to a position a predetermined distance D from the leading edge 101a of the banknote 101. FIG. 2 is a flowchart showing an example of a process flow relating to the detection of a wet banknote by the banknote recognition device 1 of the present embodiment.

One embodiment of the present invention (hereinafter referred to as "this embodiment") will be described below with reference to the drawings.

The banknote validation device 1 of this embodiment is characterized by its control over the detection of wet banknotes.

First, we will explain the basic configuration of the banknote validator 1.

Figure 1 is a vertical cross-sectional view showing the configuration of the banknote validator 1 of this embodiment.

The banknote identification device 1 includes an insertion slot 2, a transport path 3, a transport means 4, an identification sensor 5, a banknote storage unit 6, an entrance sensor 81, and a control unit 9.

The insertion slot 2 is the opening through which the banknote 101 is inserted.

The transport path 3 is a path along which banknotes 101 inserted into the insertion slot 2 are transported. The transport path 3 is connected to the insertion slot 2.

The conveying means 4 is a means for conveying banknotes 101 along the conveying path 3. The conveying means 4 has a conveying belt 41, a driving pulley 42, a driven pulley 43, a pressure roller 44, and a motor 45. In the example shown in FIG. 1, the conveying means 4 has two driven pulleys 43. The conveying means 4 also has four pressure rollers 44.

Motor 45 is a stepping motor whose rotation direction, rotation angle, and rotation speed can be controlled. The rotation direction of motor 45 is controlled by a rotation direction signal input to motor 45. Specifically, a high-level signal is input to rotate motor 45 in the forward direction, and a low-level signal is input to rotate motor 45 in the reverse direction. The rotation angle of motor 45 is controlled by the number of pulses in a pulse signal input to motor 45. Specifically, the rotation angle of motor 45 is proportional to the number of pulses in the pulse signal. The rotation speed of the motor is controlled by the pulse speed (pulse frequency) of the pulse signal input to motor 45. Specifically, the rotation speed of motor 45 is proportional to the pulse speed of the pulse signal.

The drive pulley 42 rotates due to the driving force transmitted from the motor 45. The conveyor belt 41 is wound around the drive pulley 42 and the driven pulley 43. The conveyor belt 41 moves in response to the rotation of the drive pulley 42. The movement direction of the conveyor belt 41 is controlled by a rotation direction signal input to the motor 45. The movement distance of the conveyor belt 41 is controlled by the number of pulses in a pulse signal input to the motor 45. The speed of the conveyor belt 41 is controlled by the pulse speed of the pulse signal input to the motor 45.

The pressure roller 44 is positioned opposite the drive pulley 42 or driven pulley 43 with the conveyor belt 41 in between. The banknotes 101 are held between the conveyor belt 41 and the pressure roller 44 and conveyed. The banknotes 101 held between the conveyor belt 41 and the pressure roller 44 move in accordance with the movement of the conveyor belt 41. In other words, the conveyance direction of the banknotes 101 is controlled by a rotation direction signal input to the motor 45. The conveyance distance of the banknotes 101 is controlled by the number of pulses in the pulse signal input to the motor 45. The conveyance speed of the banknotes 101 is controlled by the pulse speed of the pulse signal input to the motor 45.

In this embodiment, the motor 45 is a stepping motor whose rotation direction, rotation angle, and rotation speed are controlled by a rotation direction signal, the number of pulses in a pulse signal, and the pulse speed of the pulse signal, respectively. However, the motor 45 of the present invention is not limited to this. The motor 45 of the present invention may be any motor that can at least control the movement direction, movement distance, and movement speed of the conveyor belt 41. For example, a DC motor may be used as the motor 45. In this case, the movement direction of the conveyor belt 41 is controlled by the direction of the current input to the DC motor. Furthermore, the movement distance and movement speed of the conveyor belt 41 are controlled by feedback control using a measuring device such as a tachometer.

The identification sensor 5 is a sensor for identifying the banknote 101. More specifically, the identification sensor 5 is a sensor for identifying the type and authenticity of the banknote 101. The identification sensor 5 is arranged on the inner wall surface of the transport path 3.

Figure 2 is a vertical cross-sectional view showing the configuration around the identification sensor 5 of the banknote identification device 1 of this embodiment.

The identification sensor 5 includes an optical sensor 51 and a magnetic sensor 52.

The optical sensor 51 detects the amount of light transmitted through the banknote being transported in the transport path 3. The optical sensor 51 has a light-emitting element 51a and a light-receiving element 51b. The light-emitting element 51a and the light-receiving element 51b are arranged opposite each other across the transport path 3. The optical sensor 51 sequentially detects the amount of light transmitted through the area between the light-emitting element 51a and the light-receiving element 51b on the banknote being transported.

The magnetic sensor 52 detects the magnetic information of the banknote. The magnetic sensor 52 has a magnetic head 52a and a pressure roller 52b. The magnetic head 52a and the pressure roller 52b are arranged opposite each other across the transport path 3. The magnetic sensor 52 sequentially detects the magnetic information of the area of the transported banknote that is close to the magnetic head 52a.

The banknote validator 1 identifies the type and authenticity of the banknote 101 based on the amount of light transmitted through the banknote detected by the optical sensor 51 and the magnetic information of the banknote detected by the magnetic sensor 52.

The banknote storage unit 6 is a section that stores banknotes 101. The banknote storage unit 6 has a stack plate 61 and a biasing member 62 that constantly biases the stack plate 61 toward the transport path 3. The biasing member 62 is, for example, a compression spring. The banknote validation device 1 also has a banknote pressing plate 65 that is positioned opposite the stack plate 61 of the banknote storage unit 6 across the transport path 3. The banknote validation device 1 moves the banknote pressing plate 65 toward the inside of the banknote storage unit 6 and presses the banknotes 101 in the transport path 3 onto the stack plate 61, thereby stacking and storing the banknotes 101 on the stack plate 61.

The entrance sensor 81 is a sensor for detecting the presence of banknotes 101 in the area near the insertion slot 2 in the transport path 3. For example, the entrance sensor 81 can detect the insertion of banknotes 101 into the insertion slot 2 and the ejection of banknotes 101 from the insertion slot 2. The entrance sensor 81 is configured, for example, by an optical sensor having a light-emitting element and a light-receiving element.

The control unit 9 controls the overall operation of the banknote validation device 1. In this specification, the controls and processes described as being performed by the banknote validation device 1 can be said to be performed by the control unit 9 of the banknote validation device 1.

Figure 3 is a block diagram showing the configuration of the control unit 9 of the banknote validation device 1 of this embodiment.

The control unit 9 has a processor 91 and a memory unit 92. The processor 91 controls the operation of the banknote validation device 1 in accordance with a program recorded in the memory unit 92. The processor 91 is configured, for example, by a CPU (Central Processing Unit). The memory unit 92 stores programs and calculation parameters used by the processor 91. The memory unit 92 is configured, for example, by a RAM (Random Access Memory), a ROM (Read Only Memory), etc.

The control unit 9 controls the transport direction, travel distance, and travel speed of the banknotes 101, for example, by inputting a rotation direction signal and a pulse signal to the motor 45. The control unit 9 also determines the type and authenticity of the banknote based on the output of the optical sensor 51 and magnetic sensor 52 of the recognition sensor 5. The control unit 9 also detects wet banknotes based on the output of the optical sensor 51 of the recognition sensor 5, and controls the return operation of the wet banknotes. The control unit 9 also receives the output of the entrance sensor 81 and controls the transport operation of the banknotes.

Next, we will explain the control involved in detecting wet banknotes in the banknote validation device 1 of this embodiment.

As a premise, the banknote validation device 1 of this embodiment is capable of accepting two or more types of banknotes. For example, the banknote validation device 1 of this embodiment may be configured to accept two types of banknotes, F,000 yen notes (thousand yen notes issued in 2024) and E,000 yen notes (thousand yen notes issued in 2004); three types of banknotes, F,000 yen notes, E,000 yen notes, and 2,000 yen notes; five types of banknotes, F,000 yen notes, E,000 yen notes, 2,000 yen notes, F,5,000 yen notes (5,000 yen notes issued in 2024), and E,5,000 yen notes (5,000 yen notes issued in 2004); or seven types of banknotes, F,000 yen notes, E,000 yen notes, 2,000 yen notes, F,5,000 yen notes, E,5,000 yen notes, F,10,000 yen notes (10,000 yen notes issued in 2024), and E,10,000 yen notes (10,000 yen notes issued in 2004).

The banknote validator 1 of this embodiment is characterized in that the validator sensor 5, which is a sensor for identifying the type and authenticity of banknotes 101, is also used to detect wet banknotes. Specifically, the banknote validator 1 of this embodiment detects wet banknotes based on the amount of light transmitted through the banknote detected by the optical sensor 51 of the validator sensor 5.

Figure 4 shows an example of the amount of light transmitted through a banknote detected by the optical sensor 51 of the identification sensor 5.

After the leading edge of a banknote 101 being transported in the transport path 3 reaches the optical sensor 51, the banknote validation device 1 acquires the output value of the optical sensor 51 at predetermined intervals. The output value of this optical sensor 51 corresponds to the amount of light transmitted through the banknote 101. In this way, the banknote validation device 1 detects the amount of light transmitted through the banknote 101 at multiple read addresses N along a sensor read line L set on the surface of the banknote 101.

The sensor read line L is a line that indicates the area on the banknote 101 where the amount of transmitted light is detected by the optical sensor 51. The position of the sensor read line L on the banknote 101 can be set as desired by adjusting the positional relationship between the light-emitting element 51a and light-receiving element 51b of the optical sensor 51 and the transport path 3. Multiple sensor read lines L may also be set using multiple optical sensors 51.

The read address N is an address that has a one-to-one correspondence with a position on the banknote 101. In the banknote identification device 1 of this embodiment, the read address N takes an integer value, and 1 is added each time the device proceeds to the next read address. Here, the first read address N is set to _N0 , and the final read address N is set to _Nmax . In other words, the read address N is set as an integer value within the range from _N0 to _Nmax . Furthermore, in this specification, the section between two read addresses N is referred to as the read address section.

The banknote validation device 1 of this embodiment uses a stepping motor as the driving means for the transport mechanism of the banknotes 101, and controls the transport speed of the banknotes 101 by pulse signals input to the stepping motor. In the banknote validation device 1 of this embodiment, the optical sensor 51 detects the amount of light transmitted through the banknote at the timing of the input of this pulse signal. In other words, each read address N of the banknote validation device 1 of this embodiment corresponds one-to-one to each pulse signal input to the driving means of the transport mechanism.

The banknote validation device 1 of the present invention is not limited to one that uses a stepping motor as the driving means for the transport mechanism of the banknotes 101. For example, the banknote validation device 1 of the present invention may use a DC motor as the driving means for the transport mechanism of the banknotes 101. In this case, the transport of the banknotes 101 is controlled by feedback control using an encoder sensor that generates a pulse signal corresponding to the amount of rotation of the DC motor. In this case, each read address N of the banknote validation device 1 can be made to correspond one-to-one with each pulse signal emitted by the encoder sensor.

As shown in Figure 4, the amount of light transmitted through a wet banknote is greater than the amount of light transmitted through a dry banknote. This property allows the banknote validator 1 to detect a wet banknote based on the amount of light transmitted through the banknote detected by the optical sensor 51.

After a banknote 101 inserted through the insertion slot 2 and transported within the transport path 3 reaches the optical sensor 51 of the recognition sensor 5, the banknote recognition device 1 uses the optical sensor 51 to sequentially detect the amount of light transmitted through the banknote 101 being transported within the transport path 3. The banknote recognition device 1 then updates the maximum amount of light transmitted through the banknote 101 each time it detects the amount of light transmitted through the banknote 101 being transported.

When the maximum value of the amount of light transmitted through the banknote 101 sequentially detected by the optical sensor 51 exceeds a predetermined determination threshold, the banknote validation device 1 determines that the banknote 101 being transported is a wet banknote. If the banknote validation device 1 determines that the banknote 101 being transported is a wet banknote, it immediately performs a process to return the banknote 101. This process of returning the banknote 101 involves moving the conveyor belt 41 in the reverse direction to transport the banknote 101 to the insertion slot 2 and ejecting it from the insertion slot 2.

The amount of light transmitted through a wet banknote varies depending on the type of banknote. Therefore, the judgment threshold for detecting wet banknotes is set according to the type of banknote that the banknote validation device 1 can accept. Specifically, a judgment reference value for detecting wet banknotes is set for each type of banknote. The predetermined judgment threshold is then the judgment reference value of the wettest banknote that the banknote validation device 1 can accept, with the greatest amount of transmitted light. In other words, for a specific banknote validation device 1, the judgment reference value of the wettest banknote that the banknote validation device 1 can accept, with the greatest amount of transmitted light, is set as the predetermined judgment threshold. For example, for a banknote validation device 1 that accepts two types of banknotes, F 1000 yen notes and E 1000 yen notes, the judgment reference value of the F 1000 yen note, which has a relatively large amount of transmitted light, is set as the predetermined judgment threshold.

Furthermore, the banknote recognition device 1 of this embodiment is characterized by making a provisional determination of the type of banknote 101 while the banknote 101 is being transported, and changing the determination threshold for determining whether the banknote is wet depending on the result of this provisional determination.

Specifically, when the optical sensor 51 has detected the amount of light transmitted through the banknote 101 up to a position a predetermined distance D from the leading edge 101a of the banknote 101, the banknote recognition device 1 makes a provisional determination of the denomination of the banknote 101 based on the data of the amount of light transmitted through the banknote 101 detected up to that point. In other words, when the optical sensor 51 has detected the amount of light transmitted through the banknote 101 up to a predetermined read address _Na , the banknote recognition device 1 makes a provisional determination of the denomination of the banknote 101 based on the data of the amount of light transmitted through the banknote 101 in a read address section _Ia from the first read address _N0 to the predetermined read address _Na .

The banknote validation device 1 then updates the value of the aforementioned predetermined judgment threshold depending on the result of the provisional judgment of the type of banknote 101. Specifically, if the judged type of banknote has a judgment reference value smaller than the aforementioned predetermined judgment threshold, the banknote validation device 1 changes the predetermined judgment threshold to the judgment reference value of the judged type of banknote. For example, in a banknote validation device 1 that accepts two types of banknotes, F 1000 yen notes and E 1000 yen notes, if the judged type of banknote is an E 1000 yen note, which has a relatively small amount of transmitted light, the predetermined judgment threshold is changed to the judgment reference value of the E 1000 yen note.

In this way, by updating the judgment threshold value for detecting wet banknotes while the banknotes 101 are being transported, wet banknotes can be detected with high accuracy even in a banknote recognition device 1 that accepts two or more types of banknotes 101.

Here, we will explain an example of the process for provisionally determining the type of banknote 101 mentioned above.

The banknote validator 1 uses reference transmitted light intensity data prepared for each banknote type and orientation to provisionally determine the type of banknote 101. There are four orientations for banknotes: front, back, and longitudinal direction. The reference transmitted light intensity data is a combination of the read address N and transmitted light intensity, created based on measurement data from a large number of banknotes.

The banknote identification device 1 can determine the type of banknote 101 by comparing the reference transmitted light intensity data prepared for each type and orientation of banknote with the transmitted light intensity data of the banknote 101 in the read address section _Ia from the first read address _N0 to a predetermined read address N _a .

Note that in the provisional determination of the type of banknote 101 described above, it is not necessary to identify the type of banknote 101. In the provisional determination of the type of banknote 101 described above, it is sufficient to at least be able to distinguish between wet banknotes with a relatively high amount of transmitted light and wet banknotes with a relatively low amount of transmitted light.

Figure 5 is a vertical cross-sectional view showing the position of the banknote 101 within the banknote validation device 1 at the time when the optical sensor 51 of the validation sensor 5 detects the amount of light transmitted through the banknote 101 up to a position a predetermined distance D from the leading edge 101a of the banknote 101.

It is preferable to make a provisional determination of the type of the banknote 101 as soon as possible in order to detect a wet banknote as soon as possible. From this perspective, it is preferable that the aforementioned predetermined distance D is 40% or less of the longitudinal length of the banknote 101. In other words, it is preferable that the aforementioned predetermined read address _Na is set so that the distance from the leading edge 101a of the banknote 101 to the position on the banknote 101 corresponding to that read _address Na is 40% or less of the longitudinal length of the banknote 101.

Furthermore, in order to ensure a certain level of accuracy in determining the type of banknote 101, it is necessary to obtain data on the amount of light transmitted through the banknote 101 over a certain distance. From this perspective, it is preferable that the aforementioned predetermined distance D be 10% or more of the longitudinal length of the banknote 101. In other words, it is preferable that the aforementioned predetermined read address Na be set so that the distance from the leading edge 101a of the banknote 101 to the position on the banknote 101 corresponding to that read address Na is 10% or more of the longitudinal length of the banknote 101.

Furthermore, the aforementioned predetermined distance D is preferably set so that the rear end 101b of the banknote 101 protrudes from the insertion slot 2 when the optical sensor 51 detects the amount of light transmitted through the banknote 101 up to a position at the predetermined distance _D from the front end 101a of the banknote 101. In other words, the predetermined read address Na is preferably set so that the rear end of the banknote 101 protrudes from the insertion slot 2 when the optical sensor 51 detects the amount of light transmitted through the banknote 101 at the predetermined read address _Na . This makes it possible to manually remove the banknote 101 from the banknote recognition device 1 even when a banknote jam occurs.

Figure 6 is a flow diagram showing an example of the processing flow for detecting wet banknotes by the banknote recognition device 1.

When the optical sensor 51 of the identification sensor 5 detects the passage of a banknote 101, the banknote identification device 1 starts processing related to identifying the type and authenticity of the banknote 101, as well as processing related to detecting wet banknotes.

When the banknote validator 1 starts the process of detecting a wet banknote, it sets the reading address N of the optical sensor 51 to the first reading address _N0 (S1).

Next, the banknote validation device 1 performs a process to update the maximum amount of light transmitted through the banknote 101 (S2). Specifically, the banknote validation device 1 reads the amount of light transmitted through the banknote 101 at read address N and updates the maximum amount of light transmitted through the banknote 101.

Next, the banknote validator 1 performs a process of comparing the maximum amount of light transmitted through the banknote 101 with a predetermined judgment threshold (S3).

Here, if the maximum amount of light transmitted through the banknote 101 is equal to or greater than a predetermined judgment threshold (i.e., if the banknote 101 is judged to be a wet banknote), the banknote 101 is returned (S12).

If the maximum value of the amount of light transmitted through the banknote 101 is not equal to or greater than the predetermined determination threshold, the banknote recognition device 1 determines whether the read address N is less than a predetermined read address _Na (S4).

Here, if the read address N is less than the predetermined read address _Na , the banknote identification device 1 advances the read address N by one (S5), and then returns to the process of updating the maximum amount of transmitted light of the banknote 101 (S2), and repeats the same process.

On the other hand, if the read address N is not less than the predetermined read address _Na (i.e., if the read address N reaches the predetermined read address _Na ), the banknote recognition device 1 performs a process of provisionally determining the type of the banknote 101 (S6).

The banknote recognition device 1 then updates the predetermined judgment threshold based on the result of the judgment (S7). Specifically, if the determined banknote type has a judgment reference value that is smaller than the aforementioned predetermined judgment threshold, the banknote recognition device 1 changes the predetermined judgment threshold to the judgment reference value for that determined banknote type.

Next, the banknote recognition device 1 performs a process of comparing the maximum amount of light transmitted through the banknote 101 with the updated judgment threshold (S8). Note that the maximum amount of light transmitted through the banknote 101 compared with the updated judgment threshold here is not the maximum amount of light transmitted through the banknote 101 after the judgment threshold update process (S7), but the maximum amount of light transmitted through the banknote 101 since the start of the process related to detecting wet banknotes.

Here, if the maximum amount of light transmitted through the banknote 101 is equal to or greater than the updated determination threshold (i.e., if the banknote 101 is determined to be a wet banknote), the banknote is returned (S12).

On the other hand, if the maximum value of the amount of light transmitted through the banknote 101 is not equal to or greater than the updated determination threshold, the banknote recognition device 1 determines whether the read address N is less than the final read address _Nmax (S9).

Here, if the read address N is less than the final read address _Nmax , the banknote recognition device 1 advances the read address N by one (S10) and updates the maximum amount of light transmitted through the banknote 101 (S11), and then returns to the process of comparing the maximum amount of light transmitted through the banknote 101 with the updated judgment threshold (S8), and repeats the same process.

On the other hand, if the read address N is not less than the final read address _Nmax (that is, if the read address N reaches the final read address _Nmax ), the banknote validation device 1 ends the wet banknote detection process.

To summarize the above, the banknote recognition device 1 of this embodiment comprises an insertion slot 2 into which a banknote 101 is inserted, a transport path 3 along which the banknote 101 is transported, a recognition sensor 5 that recognizes the banknote 101, and a control unit 9. The recognition sensor 5 has an optical sensor 51 that sequentially detects the amount of light transmitted through the banknote 101 being transported in the transport path 3. When the maximum amount of light transmitted through the banknote 101 detected by the optical sensor 51 exceeds a predetermined judgment threshold, the control unit 9 determines that the banknote 101 is a wet banknote and returns the banknote 101 from the insertion slot 2.

Since this type of banknote validation device 1 uses the optical sensor 51 of the validation sensor 5, there is no need to install additional components, which helps to reduce costs and the reject rate. Furthermore, since this type of banknote validation device 1 uses the optical sensor 51 of the validation sensor 5, which has high detection accuracy, it has high accuracy in detecting wet banknotes. Furthermore, since this type of banknote validation device 1 immediately performs the return process for the banknote 101 after determining that the banknote 101 is a wet banknote, it can effectively prevent wet banknotes from clogging the transport path 3.

Furthermore, the banknote recognition device 1 of this embodiment can accept two or more types of banknotes 101, and when the optical sensor 51 detects the amount of light transmitted through the banknote 101 up to a position a predetermined distance D from the leading edge 101a of the banknote 101, the control unit 9 makes a provisional determination of the type of banknote 101 based on the data on the amount of light transmitted through the banknote 101 detected up to that point, and updates the value of the predetermined determination threshold according to the result of that determination.

This type of banknote validation device 1 can accurately detect wet banknotes even when it accepts two or more types of banknotes 101.

Although one embodiment of the present invention has been described above, the banknote validation device of the present invention is not limited to the above-described embodiment. The banknote validation device of the present invention can be embodied in a variety of other forms, and various omissions, substitutions, modifications, and additions can be made without departing from the spirit of the invention.

The present invention can also be configured as follows.
[Item 1]
A banknote recognition device comprising: an insertion slot into which banknotes are inserted; a conveyance path through which the banknotes are conveyed; a recognition sensor that recognizes the banknotes; and a control unit,
The identification sensor has an optical sensor that sequentially detects the amount of light transmitted through the banknotes being transported in the transport path,
When the maximum value of the amount of light transmitted through the banknote detected by the optical sensor is equal to or greater than a predetermined determination threshold, the control unit determines that the banknote is a wet banknote and returns the banknote from the insertion slot.
[Item 2]
Item 1: A bill validator according to item 1,
capable of accepting two or more denominations of said banknotes;
When the optical sensor detects the amount of light transmitted through the banknote up to a position a predetermined distance from the leading edge of the banknote, the control unit provisionally determines the type of the banknote based on the data on the amount of light transmitted through the banknote that has been detected up to that point, and updates the value of the predetermined determination threshold value according to the result of the determination.
[Item 3]
Item 2: A bill validator according to the present invention,
A reference value for determining whether a banknote is wet is set for each type of banknote,
the determination reference value of the banknote type with the largest determination reference value is set as the predetermined determination threshold value;
a banknote recognition device that, when the determination reference value for the banknote type determined in the provisional determination of the banknote type is smaller than the predetermined determination threshold, changes the value of the predetermined determination threshold to the determination reference value for the banknote type determined in the provisional determination of the banknote type.
[Item 4]
The banknote validator according to item 2 or 3,
The predetermined distance is set so that the rear end of the banknote is protruding from the insertion slot when the optical sensor detects the amount of light transmitted through the banknote up to the predetermined distance from the front end of the banknote.

REFERENCE SIGNS LIST 1 Banknote validator 2 Insertion slot 3 Conveying passage 4 Conveying means 41 Conveying belt 42 Driving pulley 43 Driven pulley 44 Pressing roller 45 Motor 5 Identification sensor 51 Optical sensor 51a Light-emitting element 51b Light-receiving element 52 Magnetic sensor 52a Magnetic head 52b Pressing roller 6 Banknote storage section 61 Stack plate 62 Urging member 65 Banknote pressing plate 9 Control section 91 Processor 92 Memory section 81 Entrance sensor 101 Banknote

Claims (3)

A banknote recognition device comprising: an insertion slot into which banknotes are inserted; a conveyance path through which the banknotes are conveyed; a recognition sensor that recognizes the banknotes; and a control unit,
capable of accepting two or more denominations of said banknotes;
The identification sensor has an optical sensor that sequentially detects the amount of light transmitted through the banknotes being transported in the transport path,
the control unit determines that the banknote is wet when the maximum value of the amount of light transmitted through the banknote detected by the optical sensor is equal to or greater than a predetermined determination threshold, and returns the banknote from the insertion slot ;
When the optical sensor detects the amount of light transmitted through the banknote up to a position at a predetermined distance from the leading edge of the banknote, the control unit provisionally determines the type of the banknote based on data on the amount of light transmitted through the banknote that has been detected up to that point, and updates the value of the predetermined determination threshold value according to the result of the determination.
Banknote validator. 2. The banknote validator according to claim 1 ,
A reference value for determining whether a banknote is wet is set for each type of banknote,
the determination reference value of the banknote type with the largest determination reference value is set as the predetermined determination threshold value;
a banknote recognition device that, when the determination reference value for the banknote type determined in the provisional determination of the banknote type is smaller than the predetermined determination threshold, changes the value of the predetermined determination threshold to the determination reference value for the banknote type determined in the provisional determination of the banknote type. 2. The banknote validator according to claim 1 ,
The predetermined distance is set so that the rear end of the banknote is protruding from the insertion slot when the optical sensor detects the amount of light transmitted through the banknote up to the predetermined distance from the front end of the banknote.