JP4830038B1 - Magnetic detector - Google Patents

Abstract

An object of the present invention is to provide a magnetic detection device capable of discriminating between application of a magnetic field from a detection object and application of a magnetic field from a non-detection object and accurately detecting application of the magnetic field from the non-detection object.
A magnetic detection device according to the present invention includes a sensor unit that outputs an output signal in accordance with an applied magnetic field, and a calculation unit that calculates an output signal of the sensor unit. The amount of change in the azimuth angle θ between the magnetic vectors of each output signal calculated from the output signal is compared with a preset threshold value to identify whether a magnetic field is applied from a non-detection target.
[Selection] Figure 2

Description

  The present invention relates to a magnetic detection device, for example, a magnetic detection device used for detection of fraud using a magnet for a ball game machine.

  In recent years, illegal actions using magnets have become a problem in ball game machines. This dishonest act is to attract a game ball that rolls and falls in the game area by bringing a magnet close to the glass in front of the ball game machine, and the attracted game ball enters the entrance of the center object device in the center of the game area. This is done by guiding. In order to prevent such an illegal act, a ball game machine including a magnetic detection device that detects a magnetic field applied to a game area through a glass has been proposed (for example, see Patent Document 1). In such a ball game machine, a magnetic detection sensor is disposed near the entrance of the center accessory device, and a magnetic field applied to the vicinity of the entrance is detected by the magnetic detection sensor. When the magnet attracting the game ball moves to the vicinity of the entrance, the magnetic field applied by the magnet is detected by the magnetic detection device, so that an illegal act using the magnet can be detected.

JP 2010-29391 A

  By the way, in a ball game machine, a solenoid is used to drive a plurality of rotating bodies that guide the game ball that has entered the entrance to the start winning opening, and various effect devices of the center accessory device. . This solenoid has a coil inside, and drives various rendering devices by a magnetic field generated by energizing the coil. In the conventional ball game machine, since the solenoid is installed near the entrance of the center accessory device, the magnetic field generated by the operation of the solenoid is detected as the magnetic field applied by the magnet used for fraud. There was a problem. For this reason, in conventional ball game machines, it is difficult to distinguish between the application of a magnetic field from a magnet as a detection target and the application of a magnetic field from a solenoid as a detection target. It was difficult to accurately detect only.

  The present invention has been made in view of such points, and can distinguish between the application of a magnetic field from a detection object and the application of a magnetic field from a non-detection object, and accurately apply a magnetic field from a non-detection object. An object of the present invention is to provide a magnetic detection device capable of detection.

  The magnetic detection device of the present invention includes a magnetic sensor that outputs an output signal according to an applied magnetic field, and an arithmetic unit that calculates the output signal of the magnetic sensor, and each of the values calculated from the output signal of the magnetic sensor A feature is characterized in that whether or not a magnetic field is applied from a non-detection object is identified by comparing the amount of change in the azimuth angle θ between magnetic vectors of the output signal with a preset threshold value.

  According to this configuration, when the application of the magnetic field from the non-detection target is detected, the amount of change in the azimuth angle θ between the magnetic vectors calculated from each output signal of the magnetic sensor increases. Therefore, by comparing the amount of change in the azimuth angle θ between the magnetic vectors of each output signal calculated from the output signal of the magnetic sensor with a preset threshold, it is possible to apply a magnetic field from a non-detection target. Whether or not can be identified.

In the magnetic detection device of the present invention, the calculation unit calculates the azimuth angle θ between the magnetic vectors of each output signal from the output signal of the magnetic sensor according to the following relational expression (1). It is preferable to identify whether or not a magnetic field is applied from a non-detection object by comparing the amount of change in the azimuth angle θ between magnetic vectors with a preset threshold value. According to this configuration, since the calculation accuracy of the azimuth angle θ is improved, it is possible to accurately identify whether or not the magnetic field is applied from the non-detecting body.

  In the magnetic detection device of the present invention, the calculation unit calculates an azimuth angle θ between magnetic vectors of each output signal from the output signal of the magnetic sensor with a predetermined time constant, and the magnetic vector of each output signal at each time point. It is preferable to identify whether or not the object is a non-detection object by an arithmetic process using the amount of change in the azimuth angle θ between them and the amount of change in magnetic field strength at each time point or in a predetermined period before and after each time point. According to this configuration, since the azimuth angle θ between the magnetic vectors of each output signal is calculated from the output signal of the magnetic sensor with a predetermined time constant, it is possible to accurately identify whether the object is a non-detection target. . Also, whether or not the object is a non-detection object is calculated by an arithmetic process using the amount of change in the azimuth angle θ between the magnetic vectors of each output signal and the amount of change in the magnetic field strength at each time point or in a predetermined period before and after each time point. Therefore, the influence of noise can be reduced.

  In the magnetic detection apparatus of the present invention, it is preferable that the calculation unit uses a maximum value of the change amount of the magnetic field strength in the predetermined period in the calculation process. With this configuration, the detection accuracy of the detection target object is improved.

  In the magnetic detection apparatus of the present invention, it is preferable that the calculation unit uses an average value of the change amount of the magnetic field intensity in the predetermined period in the calculation process. With this configuration, the detection accuracy of the detection target object is improved.

  In the magnetic detection device according to the aspect of the invention, it is preferable that the calculation unit uses a statistical value including a median value or a variance value of the change amount of the magnetic field strength in the predetermined period in the calculation process. With this configuration, the detection accuracy of the detection target object is improved.

  In the magnetic detection device of the present invention, the arithmetic unit, in the arithmetic processing, includes a change amount of the azimuth angle θ between the magnetic vectors of each output signal at each time point and a magnetic field in each time point or a predetermined period before and after each time point. It is preferable to multiply the intensity change amount. With this configuration, the detection accuracy of the detection target object can be improved.

  In the magnetic detection apparatus of the present invention, it is preferable that the magnetic sensor is composed of a GMR element. With this configuration, the detection range of the magnetic detection device can be expanded.

  A gaming machine according to the present invention includes a housing and the magnetic detection device provided in the housing.

  According to this configuration, it is possible to distinguish between the application of the magnetic field from the detection target from the front side of the housing and the application of the magnetic field from the non-detection target from the inside of the housing. For this reason, it is possible to accurately detect the application of the magnetic field from the non-detection target.

  According to the present invention, it is possible to distinguish between the application of a magnetic field from a detection object and the application of a magnetic field from a non-detection object, and to provide a magnetic detection device capable of accurately detecting the application of a magnetic field from a non-detection object. Can do.

It is a perspective view of a bullet ball game machine provided with a magnetic detection device according to an embodiment of the present invention. It is a functional block diagram of the magnetic detection apparatus which concerns on embodiment of this invention. (A), (b) is a conceptual diagram of the detection principle in the magnetic detection apparatus based on this Embodiment. (A), (b) is a conceptual diagram of the arithmetic processing in the magnetic detection apparatus based on this Embodiment. It is a figure which shows an example of the control flow of the calculating part of the magnetic detection apparatus which concerns on this Embodiment. It is a figure which shows an example of the calculation result at the time of detecting the fraud with a magnet in the magnetic detection apparatus which concerns on this Embodiment. It is a figure which shows an example of the calculation result at the time of detecting the action | operation of a solenoid in the magnetic detection apparatus which concerns on this Embodiment. It is a figure which shows an example of the calculation result at the time of detecting both the illegal act by a magnet and the action | operation of a solenoid in the magnetic detection apparatus which concerns on this Embodiment. It is a figure which shows the calculation result at the time of detecting the action | operation of a plunger type solenoid in the magnetic detection apparatus which concerns on this Embodiment. It is a figure which shows the calculation result at the time of operating a solenoid continuously in the magnetic detection apparatus which concerns on this Embodiment.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the following embodiment, an example in which the magnetic detection device according to the embodiment of the present invention is applied to a ball game machine will be described. However, the magnetic detection device according to this embodiment is other than a ball game machine. It is also applicable to.

  FIG. 1 is a perspective view of a ball game machine 1 provided with a magnetic detection device according to the present embodiment. This bullet ball game machine 1 includes a housing 11 provided with a circular concave portion on the front surface, a glass plate 12 provided so as to cover the concave portion of the housing 11, and a magnetic detection device disposed in the housing 11. 13. A circular game board is fixed to the bottom of the concave portion of the housing 11 when viewed from the front, and a game area serving as a moving range of the game ball is formed between the game board and the glass plate 12. A center accessory device having a entrance is provided in the center of the game board, and various effect devices are provided in the vicinity of the entrance. The magnetic detection device 13 is arranged in the vicinity of the entrance of the game area in the center, and its detection range is so as to detect the magnetic field M1 (see FIG. 3) of the magnet 14 applied to the game area via the glass plate 12. Is set. In addition, a solenoid 15 for driving various effect devices is arranged in the center of the game board in the housing 11.

  FIG. 2 is a functional block diagram of the magnetic detection device 13 according to the present embodiment. As shown in FIG. 2, the magnetic detection device 13 includes a sensor unit 16 that detects the magnetic field M <b> 1 applied from the magnet 14, and a calculation unit 17 that performs calculation processing on the output signal of the sensor unit 16. The sensor unit 16 includes a magnetic sensor that detects magnetic fields M1 and M2 (see FIG. 3) applied from the magnet 14 and the solenoid 15, and outputs signals according to the magnetic fields M1 and M2 applied from the magnet 14 and the solenoid 15. Is output. The sensor unit 16 includes a processing unit for applying a voltage and a magnetic field to the sensor unit 16 and a processing unit for converting an analog signal from the sensor unit 16 into a digital signal. The magnetic sensor of the sensor unit 16 is not particularly limited as long as it can detect the magnetic fields M1 and M2 applied from the magnet 14 and the solenoid 15. For example, magnetoresistive elements such as GMR (Giant Magneto Resistive effect), AMR (Anisotropic Magneto Resistance), TMR (Tunnel Magneto Resistance) elements, Hall elements, Hall ICs, magnetic diodes, magnetic transistors, and the like can be used. Among these, it is preferable to use a GMR element. By using the GMR element, the detection range of the magnet 14 by the magnetic detection device 13 can be expanded. As the magnetic sensor of the sensor unit 16, a multilayer GMR element may be used. In this case, with respect to the magnet 14 that applies the magnetic field M1 perpendicularly to the game area from the outer surface of the glass plate 12, the easy axis direction formed in the manufacturing process of the multilayer GMR element is directed to the detection direction. The detection range can be further expanded.

  The calculation unit 17 is electrically connected to the sensor unit 16 and calculates the output signal output from the sensor unit 16. In the calculation unit 17, the change amount of the magnetic field strength and the change amount of the azimuth angle θ between the magnetic vectors of each output signal are calculated from the output signals continuously output from the sensor unit 16. In the magnetic detection device 13 according to the present embodiment, the change amount of the azimuth angle θ between the magnetic vectors of each output signal is calculated, and the calculated change amount of the azimuth angle θ is compared with a predetermined threshold value. The magnetic field applied to the magnetic detection device 13 is identified as the magnetic field M1 from the magnet 14 as the detection target or the magnetic field M2 from the solenoid 15 as the non-detection target.

  Next, the detection principle of the magnetic detection device 13 according to the present embodiment will be described with reference to FIG. 3A and 3B are conceptual diagrams of a detection principle in the magnetic detection device according to the present embodiment. 3A and 3B, for convenience of explanation, the housing 11 is omitted, and the positional relationship between the magnetic detection device 13, the magnet 14, and the solenoid 15 is schematically shown. As shown in FIGS. 3 (a) and 3 (b), in the ball game machine 1, a solenoid 15 is disposed in the vicinity of the magnetic detection device 13 inside the housing 11 via the glass plate 12.

  As shown in FIG. 3A, when detecting an illegal act by the magnet 14, the magnetic detection device 13 approaches the glass plate 12 from the outside of the housing 11 through the glass plate 12 when viewed from the inside of the housing 11. The magnet 14 to be detected is detected (see arrow D1). For this reason, in the magnetic detection apparatus 13, the magnetic field M1 applied from the magnet 14 from the perpendicular | vertical direction (refer arrow D2) with respect to the glass plate 12 is detected. In this case, the output signal output from the sensor unit 16 increases as the magnet 14 approaches the glass plate 12.

  On the other hand, when a center accessory device (not shown) of the ball game machine 1 is driven, a solenoid 15 disposed in the vicinity of the magnetic detection device 13 is activated. In this case, as shown in FIG. 3B, the coil inside the solenoid 15 is energized with the operation of the solenoid 15, and a magnetic field M2 is formed around the solenoid 15. For this reason, the magnetic detection device 13 detects the magnetic field M2 applied from the solenoid 15 in a direction substantially parallel to the main surface of the glass plate 12 (see arrow D3). In this case, the output signal output from the sensor unit 16 according to the magnetic field M2 from the solenoid 15 becomes substantially constant according to the magnetic field M2 formed by the solenoid 15.

  That is, in the magnetic detection device 13 according to the present embodiment, the magnetic field application direction by the magnetic field M1 from the magnet 14 and the magnetic field application direction by the magnetic field M2 from the solenoid 15 are substantially orthogonal directions. As described above, when the magnetic field M1 is applied by an illegal act by the magnet 14 and the solenoid 15 is operated to change to the state where the magnetic field M2 is applied, the azimuth angle θ between the magnetic vectors of each output signal is changed. Changes significantly. For this reason, by comparing the amount of change in the azimuth angle θ between the magnetic vectors of each output signal with a predetermined threshold value set in advance, the application of the magnetic field M1 due to fraud by the magnet 14 and the driving of the solenoid 15 are performed. It is possible to discriminate the application of the magnetic field M2 associated with.

  Further, the magnitude of the output signal due to the magnetic field M1 from the magnet 14 varies greatly because the distance between the magnet 14 and the magnetic detection device 13 changes, but the magnitude of the output signal due to the magnetic field M2 from the solenoid 15 varies. Since the distance between the solenoid 15 and the magnetic detection device 13 is constant, it is substantially constant. For this reason, by using the magnetic field strength change amount of each output signal in addition to the azimuth angle θ, it is possible to accurately identify the application of the magnetic field M2 from the solenoid 15.

  Next, with reference to FIGS. 4A and 4B, the concept of arithmetic processing of the magnetic detection device according to the present embodiment will be described. FIGS. 4A and 4B are conceptual diagrams of arithmetic processing in the magnetic detection device according to the present embodiment. In FIG. 4A, the vertical axis indicates the magnetic field strength, the horizontal axis indicates time, and the change in the magnetic field strength of the output signal output from the sensor unit 16 in a predetermined time range is shown. FIG. 4B shows a concept of a three-dimensional vector in which output signals at predetermined time points A and B in FIG. 4A are expanded in the X axis direction, the Y axis direction, and the Z axis direction.

  As shown in FIG. 4A, in the magnetic detection device 13 according to the present embodiment, when the magnet is approached toward a predetermined position of the glass plate 12, the magnet 14 approaches the glass plate 12. As the value increases, the output signal increases (see point A and point B in FIG. 4A). Here, as shown in FIG. 4B, when the output signal is developed into magnetic vectors in the three-axis directions for the points A and B in the process of bringing the magnet 14 closer to the glass plate 12, at point A, (Ax, Ay, Az), and at point B, (Bx, By, Bz). In addition, a predetermined azimuth angle θ is generated between the magnetic vector in the triaxial direction at the point A and the magnetic vector in the triaxial direction at the point B. Thus, by calculating the azimuth angle θ between the magnetic vector in the triaxial direction at the point A and the magnetic vector in the triaxial direction at the point B, the change in the magnetic field application direction can be obtained. It is possible to distinguish between the application of the magnetic field M1 from the magnetic field M1 and the application of the magnetic field M2 from the solenoid 15.

In the calculation process of the calculation unit 17, the calculation accuracy of the azimuth angle θ can be improved by calculating the azimuth angle θ between the magnetic vectors in the three-axis directions of each output signal by the following relational expression (1). For this reason, the application of the magnetic field M1 from the magnet 14 and the application of the magnetic field M2 from the solenoid 15 can be accurately distinguished. Further, by multiplying the calculated change amount of the azimuth angle θ and the change amount of the magnetic field strength to determine whether or not the magnetic field M2 is applied from the solenoid 15, for example, application of a weak magnetic field from the inside of the housing 11 is performed. Therefore, it is possible to accurately identify the operation of the solenoid 15 as a non-detection target.

Next, with reference to FIG. 5, the control flow of the calculating part 17 of the magnetic detection apparatus based on this Embodiment is demonstrated in detail. FIG. 5 is a diagram illustrating an example of a control flow of the calculation unit 17 of the magnetic detection device according to the present embodiment. As shown in FIG. 5, after the measurement is started, first, the output signal of the sensor unit 16 is detected with a predetermined time constant, the magnetic vector in the three-axis direction of the output signal at each time point is calculated, and the calculated magnetic vector is used. From the relational expression (1), the azimuth angle θ between the magnetic vectors in the three-axis directions of each output signal is calculated (step ST1). Next, an azimuth angle θn having the maximum azimuth angle θ is selected from azimuth angles θ continuously calculated within a predetermined time range, and azimuths before and after the azimuth angle θn including the azimuth angle θn are selected. The angles (θn−1, θn, θn + 1) are calculated, and the change amount of the azimuth angle θ is calculated (step ST2). Next, the magnetic field strength change amount at each time point of the calculated azimuth angles (θn−1, θn, θn + 1) is calculated by the following relational expression (2), and the calculated magnetic field strength change amount and the change amount of the azimuth angle θ are calculated. Multiplication is performed to calculate a multiplication value (step ST3).
MAX (θn−1, θn, θn + 1) × DATA (n) (2)

  Next, it is determined whether or not the multiplication value calculated by the relational expression (2) is 1000 or more. If the multiplication value is 1000 or more, it is determined that the magnetic field is applied from the solenoid 15 as a non-detection target. If the multiplication value is less than 1000, it is determined that the magnetic field is applied from the magnet 14 as the detection target (step ST4). After the above calculation process is completed, the calculation starts again from step ST1.

  The determination of the magnet 14 or the solenoid 15 in step ST4 can be changed at any time as long as the application of the magnetic field M1 from the magnet 14 and the application of the magnetic field M2 from the solenoid 15 can be identified. For example, the change amount of the azimuth angle θ between the magnetic vectors of the detected output signal may be determined by providing a predetermined threshold, and the change amount of the azimuth angle θ and a predetermined time constant are combined and compared, In this time constant range, the value of the azimuth angle θ may be determined by providing a constant threshold value, or may be determined by combining the change amount of the azimuth angle θ and the magnetic field strength change amount. In particular, since a predetermined time constant is provided between the time constant and the azimuth angle θ, and the amount of change in the azimuth angle θ within a predetermined time range is obtained, the amount of change in the azimuth angle θ can be accurately detected. The detection accuracy of 15 can be improved.

  Hereinafter, the calculation result of the output signal in the calculation unit 17 of the magnetic detection device 13 according to this embodiment will be described with reference to FIGS. 6 to 9, the change in the magnetic field intensity detected by the magnetic detection device 13 is indicated by a one-dot chain line, and the change in the azimuth angle θ calculated by the relational expression (1) is indicated by a solid line. 6 to 9, a predetermined threshold L1 is set for the magnetic field strength, and changes in the magnetic field strength below the threshold L1 are determined as noise.

  FIG. 6 is a diagram illustrating an example of a calculation result when an illegal act by the magnet 14 is detected. FIG. 6 shows changes in the magnetic field strength and the azimuth angle θ when the magnet 14 is brought into contact with a predetermined position of the main surface of the glass plate 12 of the casing 11 three times. As shown in FIG. 6, when the magnet 14 is detected in the magnetic detection device 13, the magnetic field strength increases as the magnet 14 approaches, and the magnetic field strength becomes maximum when the magnet 14 is in contact with the glass plate 12. In this case, since the magnet 14 approaches the main surface of the glass plate 12 from the outside of the glass plate 12 when viewed from the inside of the housing 11, the magnet 14 is viewed from the magnetic detection device 13 between the output signals detected continuously. The change in angle between the magnetic detection device 13 and the magnet 14 is reduced. Therefore, the azimuth angle θ calculated by the relational expression (1) is a minute value.

  FIG. 7 is a diagram illustrating an example of a calculation result when the operation of the solenoid 15 is detected. FIG. 7 shows changes in the magnetic field strength and the azimuth angle θ when only the solenoid 15 is operated twice without bringing the magnet 14 closer. As shown in FIG. 7, in the magnetic detection device 13, when detecting the operation of the solenoid 15, the magnetic field strength increases substantially vertically with the operation of the solenoid 15. In this case, in the magnetic detection device 13, before the solenoid 15 is actuated, a magnetic field fluctuation (noise, etc.) outside the glass plate 12 as viewed from inside the housing 11 is mainly detected, and after the solenoid 15 is actuated, A magnetic field M2 of the solenoid 15 from the housing 11 is detected. Thus, since the magnetic vector of the output signal of the magnetic detection device 13 changes greatly with the operation of the solenoid 15, the azimuth angle θ and the magnetic field strength of the continuously detected output signal suddenly increase with the operation of the solenoid 15. To increase. Therefore, as shown in FIG. 7, the magnetic field strength and the azimuth angle θ increase vertically with the operation of the solenoid 15.

  Further, during operation of the solenoid 15, since the constant magnetic field M2 is applied from a certain direction, the magnetic field strength becomes constant, and the azimuth angle θ of the output signal continuously detected becomes a minute value. Furthermore, when the operation of the solenoid 15 is finished, the energization of the coil of the solenoid 15 is finished, so that the magnetic field strength is greatly reduced. At this time, since the magnetic vector of the output signal detected by the magnetic detection device 13 changes from the direction with respect to the solenoid 15 inside the housing 11 to the outside of the glass plate 12, even when the operation of the solenoid 15 ends. The azimuth angle θ is greatly reduced. In FIG. 7, it can be seen that the same magnetic field strength and azimuth angle θ waveforms can be obtained even when the solenoid 15 is actuated twice.

  FIG. 8 is a diagram illustrating an example of a calculation result when both an illegal act by the magnet 14 and an operation of the solenoid 15 are detected. FIG. 8 shows changes in the magnetic field strength and the azimuth angle θ when the solenoid 15 is driven for a moment without the magnet 14 and then the magnet 14 is brought into contact with the glass plate 12. As shown in FIG. 8, when the magnet 14 is not approaching and the solenoid 15 is stopped, both the magnetic field strength and the azimuth angle θ are small values. Further, when the solenoid 15 is driven for a moment, the azimuth angle θ greatly increases and decreases, and the magnetic field strength and the azimuth angle θ again become small values. Furthermore, when the magnet 14 is brought close to the glass plate 12, the magnetic field strength increases as the magnet 14 approaches. On the other hand, since the direction of application of the magnetic field by the magnet 14 is the direction of the glass plate 12 when viewed from the inside of the housing 11, the azimuth angle θ of the magnetic vector of the output signal becomes small and remains a minute value. As described above, in the magnetic detection device 13 according to the present embodiment, the change in the magnetic field strength and the change in the azimuth angle θ are clearly different when the magnet 14 approaches and when the solenoid 15 operates. It is possible to discriminate between an illegal act and approach by the magnet 14 and an application of the magnetic field M2 by the operation of the solenoid 15.

  FIG. 9 is a diagram illustrating a calculation result when the operation of the plunger-type solenoid 15 is detected. In FIG. 9, changes in the magnetic field strength and the azimuth angle θ when the plunger type solenoid 15 is driven and the position of the plunger of the solenoid 15 is changed while the solenoid 15 is driven are shown in FIG. 9. Show. As shown in FIG. 9, in this case, both the magnetic field strength and the azimuth angle θ greatly increase with the operation of the solenoid 15. When the position of the plunger changes, the magnetic field strength of the solenoid 15 increases. However, since the position of the solenoid 15 itself does not change, the azimuth angle θ has a minute value. Thus, in this example, it can be seen that even when the magnetic field strength of the solenoid 15 itself changes, the azimuth angle θ does not increase when the position of the solenoid 15 does not change. Therefore, it can be seen that the azimuth angle θ is accurately detected even when different magnetic field strengths or the magnetic field strength of the solenoid 15 itself is changed stepwise.

  In the above-described calculation process, the example in which the magnetic field strength change amount and the change amount of the azimuth angle θ are calculated using the three azimuth angles (θn−1, θn, θn + 1) has been described. The number of θ can be changed in a timely manner as long as the magnetic field M1 applied from the magnet 14 and the magnetic field M2 applied from the solenoid 15 can be discriminated. Referring to FIG. 10, the calculation result when the number of azimuth angles θ used for the calculation process is changed when the solenoid 15 is continuously operated will be described. FIGS. 10A and 10B are diagrams showing the calculation results of the change amount of the magnetic field strength and the azimuth angle θ when the solenoid 15 is operated 19 times continuously. In FIG. 10, the change in the magnetic field intensity detected by the magnetic detection device 13 is indicated by a one-dot chain line, and the transition of the change amount of the azimuth angle θ calculated by the relational expression (1) is indicated by a solid line. In the example shown in FIG. 10, a threshold value L2 is set for the change amount of the azimuth angle θ, and a change amount of the azimuth angle θ equal to or less than the threshold value L2 is detected as noise.

  In FIG. 10A, the magnetic field strength change amount and the change amount of the azimuth angle θ are calculated from the three output signals of the azimuth angles (θn−1, θn, θn + 1) according to the relational expression (2). FIG. 10 (b) shows the calculation result, and in the example shown in FIG. 10 (a), the magnetic field strength is obtained by five output signals of azimuth angles (θn−2, θn−1, θn, θn + 1, θn + 2). The calculation results when the change amount and the change amount of the azimuth angle θ are calculated are shown. As shown in FIGS. 10A and 10B, five azimuth angles (θn−2, θn−) are obtained when the arithmetic processing is performed using three azimuth angles (θn−1, θn, θn + 1). 1, θn, θn + 1, θn + 2), the amount of change in the azimuth angle θ increases and the calculation accuracy improves. As described above, it is understood that the measurement accuracy of the detection target object is improved by performing arithmetic processing using the five azimuth angles (θn−2, θn−1, θn, θn + 1, θn + 2).

  As described above, in the magnetic detection device 13 according to the present embodiment, when a magnetic field due to a non-detection target applied from a direction different from the detection target is detected, it is calculated from the output signal of the magnetic sensor. The amount of change in azimuth θ increases. Therefore, by calculating the amount of change in the azimuth angle θ calculated from the output signal of the magnetic sensor, and comparing the calculated amount of change in the azimuth angle θ with a preset threshold value, Can be identified.

  In particular, in the ball game machine 1 provided with the magnetic detection device 13 according to the above-described embodiment, for example, when the solenoid 15 is activated, a large current flows through the coil inside the solenoid 15. Since a large magnetic field fluctuation occurs, the inside of the housing 11 is the detection target direction. On the other hand, when detecting an illegal act by the magnet 14, the outside of the glass plate 12 is the detection target direction when viewed from the inside of the housing 11. Therefore, when the solenoid 15 is activated under the circumstance where the illegal action by the magnet 14 is performed, the amount of change in the magnetic field strength of the output signal and the amount of change in the azimuth angle θ both change greatly, so only the operation of the solenoid 15 is performed. Can be accurately identified. For this reason, in the ball and ball game machine 1 provided with the magnetic detection device 13 according to the above embodiment, when an illegal act by the magnet 14 is detected, an alarm is sounded to warn and the solenoid 15 is activated. Can be configured not to sound an alarm.

  In addition, this invention is not limited to the said embodiment, It can change and implement variously. In the above-described embodiment, the size, shape, and the like illustrated in the accompanying drawings are not limited to this, and can be appropriately changed within a range in which the effect of the present invention is exhibited. In addition, various modifications can be made without departing from the scope of the object of the present invention.

  For example, in the above-described embodiment, an example has been described in which a predetermined threshold value is set for the amount of change in magnetic field strength and the operation of the solenoid 15 as a non-detection target is identified. The present invention is not limited to this, and other signal changes can be combined and identified.

  In the ball game machine 1 according to the above-described embodiment, the azimuth angle θ changes abruptly as the solenoid 15 operates. For this reason, the change amount of the azimuth angle θ is calculated in a predetermined time range, and when the change amount of the azimuth angle θ exceeds the threshold value within the predetermined time range, it is identified as the solenoid 15 May be discriminated as the application of a magnetic field by the magnet 14.

  Further, when a plurality of solenoids 15 are arranged inside the ball game machine 1 and the distances between the solenoids 15 and the magnetic detection device 13 are different, a threshold is provided for the amount of change in the azimuth angle θ described above. By providing a threshold value for the magnetic field intensity change amount, it is also possible to identify which solenoid 15 is driven according to the detected magnetic field intensity change amount. In this case, the product of the magnetic field strength change amount and the change amount of the azimuth angle θ may be compared with a predetermined threshold value for identification.

  Further, in the magnetic detection device 13 according to the above-described embodiment, the example in which the output signal from the sensor unit 16 is calculated as a magnetic vector in the triaxial direction has been described. However, the calculation of the output signal from the sensor unit 16 is performed by a magnet. If the application of the magnetic field M1 from 14 and the application of the magnetic field M2 from the solenoid 15 can be discriminated, it is not always necessary to perform arithmetic processing in the three-axis directions. For example, the output signal of the sensor unit 16 may be calculated for any one of the XY plane, the YZ plane, and the XZ plane, and calculated based on the amount of change in the azimuth angle θ in any plane.

  Furthermore, in the magnetic detection device 13 according to the above-described embodiment, a target to be detected is obtained by an arithmetic process using the change amount of the azimuth angle θ of the magnetic vector in the three-axis direction of each output signal and the change amount of the magnetic field strength. Although an example of identifying whether or not an object is described has been described, the arithmetic processing can be changed in a timely manner. For example, the amount of change in the magnetic field strength used in the calculation processing is determined in consideration of the phase difference between the change in the azimuth angle θ and the change in the magnetic field strength, and the magnetic field strength in a predetermined period before and after each time point when the azimuth angle θ is calculated A change amount may be used. In this case, as the magnetic field strength change amount used for the arithmetic processing, the maximum value within a predetermined period before and after each time point may be used, or an average value may be used. Further, a statistical value including the median value or variance value of the magnetic field strength change amount calculated continuously for a predetermined period before and after each time point may be used. By performing arithmetic processing as described above, the detection accuracy of the detection target object can be improved.

  As described above, the present invention can distinguish between the application of a magnetic field from a detection object and the application of a magnetic field from a non-detection object, and can accurately detect the application of a magnetic field from a non-detection object. In particular, the present invention is useful for a magnetic detection device used for detecting fraud using a magnet for a ball game machine.

DESCRIPTION OF SYMBOLS 1 Ball game machine 11 Housing 12 Glass plate 13 Magnetic detection apparatus 14 Magnet 15 Solenoid 16 Sensor part 17 Calculation part

Claims (9)

  A magnetic sensor that outputs an output signal in accordance with an applied magnetic field, and an arithmetic unit that calculates the output signal of the magnetic sensor, and directions between magnetic vectors of the output signals calculated from the output signal of the magnetic sensor A magnetic detection device, wherein a change amount of the angle θ is compared with a preset threshold value to identify whether or not a magnetic field is applied from a non-detection target. The calculation unit calculates an azimuth angle θ between magnetic vectors of each output signal from the output signal of the magnetic sensor according to the following relational expression (1), and changes in the calculated azimuth angle θ between magnetic vectors of each output signal: The magnetic detection device according to claim 1, wherein the amount is compared with a preset threshold value to identify whether or not a magnetic field is applied from a non-detection target.

  The calculation unit calculates the azimuth angle θ between the magnetic vectors of each output signal from the output signal of the magnetic sensor with a predetermined time constant, and the amount of change in the azimuth angle θ between the magnetic vectors of each output signal at each time point 3. The magnetic detection according to claim 1, wherein whether or not the object is a non-detection object is identified by an arithmetic process using each of the time points or a change amount of the magnetic field strength in a predetermined period before and after each time point. apparatus.   The magnetic detection apparatus according to claim 3, wherein the calculation unit uses a maximum value of the change amount of the magnetic field strength in the predetermined period in the calculation process.   The magnetic detection apparatus according to claim 3, wherein the calculation unit uses an average value of the change amount of the magnetic field intensity in the predetermined period in the calculation process.   The magnetic detection apparatus according to claim 3, wherein the arithmetic unit uses a statistical value including a median value or a variance value of the magnetic field intensity change amount in the predetermined period in the arithmetic processing.   In the calculation process, the calculation unit multiplies the amount of change in the azimuth angle θ between the magnetic vectors of each output signal at each time point by the amount of change in magnetic field strength in a predetermined period before or after each time point. The magnetic detection device according to claim 3.   The magnetic detection apparatus according to claim 1, wherein the magnetic sensor includes a GMR element.   A gaming machine comprising: a housing; and the magnetic detection device according to claim 1 provided on the housing.

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