JPH0544884Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Application Field) This invention relates to a multi-channel head having a modular structure in which AC-excited magnetic heads and/or optical sensors are arranged in a line.

(Prior Art) Magnetic heads are used to read data recorded on magnetic cards, magnetic tapes, etc., and to read magnetic ink printed on banknotes, etc. There are two types of magnetic heads that have been conventionally used: AC excitation type and DC excitation type, as described below.

That is, FIG. 9 shows an AC excitation type magnetic head 10.
0, and the twin E-shaped magnetic core 1
The primary coil 1 is attached to the central connecting arm 102 of 01.
03 is wound around the primary coil 103, and an AC power source 104 is connected to the primary coil 103. Further, a secondary coil 105 is wound around the upper side of the magnetic core 101, and a cancel coil 106 is wound around the lower side of the magnetic core 101, so that a detected object 110 such as a banknote passes above the magnetic core 101. It's getting old. In such a configuration, the primary coil 103 is excited by the AC power supply 104, and when the detected object 110 containing a magnetic material passes over the head surface above the magnetic core 101, the primary coil 103 is excited depending on the amount and pattern of the magnetic material. A signal is output from the secondary coil 105. in this case,
In order to remove noise components and bias components based on fluctuations in the AC power supply 104, changes in the temperature characteristics of the magnetic core 101, etc., the difference with the output of the cancel coil 106 is taken, and the difference signal is used as a magnetic signal. ing.

In such an AC excitation type magnetic head, the secondary coil 105 and the cancel coil 106 are wound around one magnetic core 101, so the structure becomes large and it is difficult to detect the entire object 110 at the same time. In such a case, a plurality of magnetic heads 100 must be arranged at predetermined intervals and detected as shown in FIG. Therefore, the detection area becomes discrete, making it impossible to perform highly accurate detection, which poses a problem in the identification of banknotes and the like, which requires this detection.

Further, FIG. 11 shows a DC excitation type magnetic head 120.
1 of the U-shaped magnetic core 121.
An excitation coil 122 is wound around the arm.
A constant DC current is supplied to the excitation coil 122, and when the detected object 110 passes over the detection head surface, the DC current is cut off by the capacitor 123. A differential signal is obtained as a detection signal V.

In such a DC-excited magnetic head 120,
Since the detection signal V is obtained as a change in the magnetic material over time, it cannot be detected in a stationary state and has the drawback that the detection signal level varies depending on the relative speed. This DC excitation type magnetic head 12
0 is small, so some devices are arranged in a line to simultaneously detect a wide area, but they have the fatal drawbacks mentioned above and are not suitable for detecting the amount of magnetism or magnetic patterns of banknotes, etc. Ta.

(Problem to be solved by the invention) There is a magnetic head proposed in Japanese Patent Application No. 61-310277 that solves these drawbacks, but it cannot be flexibly adapted in terms of the number and arrangement of sensors, and it is not suitable as a product. The yield was poor, and there were problems in terms of cost and delivery time, and it also required a lot of effort to suppress the uneven head of each channel. Furthermore, there has been a desire for a sensor that can simultaneously measure optical patterns.

Unexamined Japanese Patent Publication 1983-11 as a unitized sensor
There is a method shown in No. 121493, but it has the disadvantage that the position is adjusted manually, which is complicated. Furthermore, there is no mention of a magnetic sensor that detects magnetic quantities or magnetic patterns, and there is no disclosure of a technique for performing alternating current excitation.

This invention was made in view of the above-mentioned circumstances, and the purpose of this invention is to simultaneously measure magnetic quantity, magnetic pattern, and The object of the present invention is to provide a modular, integrated multi-channel head that can accurately detect optical patterns and the like.

Structure of the invention; (Means for solving the problem) This invention relates to the structure of a multi-channel type head. A detection head, a canceller head wound with a primary coil for cancelling, a secondary coil for cancelling, and a casing, and the plurality of detection heads are mounted so that the detection surface is exposed, and the canceller head is inserted into the main body. A head structure embedded in the head structure is provided, the detection surfaces of each of the detection heads are aligned, and the plurality of detection heads and the cancel head are modularized and integrated via the head structure. It will be achieved. Further, by providing an optical sensor (including an optical fiber) in the detection section of the head structure, an optical pattern can also be detected.

(Function) With this device, multiple detection heads and one canceller head can be attached to the head structure and integrated into a module, and the number and position of the detection heads can also be adjusted according to the application. . Therefore, flexibility in the number of sensors is high, and the yield as a product is also improved. Further, by disposing a photodetector or an optical fiber in addition to the magnetic sensor on the detection surface, it is possible to detect an optical pattern in addition to the magnetic amount and magnetic pattern.

(Embodiment) FIG. 1 shows the external configuration of a multi-channel magnetic head 10 showing an embodiment of this invention. Magnetic heads 11 to 14, the structures of which are shown in A and B, are arranged in a line and provided as modules. Further, a cancel head 20 whose structure is shown in FIGS. 4A and 4B is buried inside the head structure 1. That is, the head structure 1 includes cavities 1A to 1D for fitting and mounting the magnetic heads 11 to 14, as shown in FIG.
Magnetic heads 11-14 are fitted into A-1D from the bottom or top, and as shown in FIG. 1, fixing holes 2A-2D are provided on the side surfaces for projecting onto the detection surface and fixing with screws or the like. Furthermore, a cavity 3 in which a cancel head 20 is buried is provided at the side end of the head structure 1. The head structure 1 is made of resin such as Bakelite or metal, and modularization may be carried out by filling the cavities 1A to 1D and 3 with an adhesive or the like.

Magnetic heads 11 to 14 and cancel head 20
The external configuration of the magnetic heads 11 to 14 is the same.
Since both have the same internal configuration, the magnetic head 11 will be explained here with reference to FIGS. 3A and 3B. The magnetic head 11 has a U-shaped magnetic core 111,
The primary coil 11 is attached to both arm parts of the magnetic core 111.
The head structure is such that the detection surface 114 of the magnetic head 11 becomes the detection head surface of the multi-channel magnetic head 10 shown in FIG. It is attached to the body 1.

Further, as shown in FIGS. 4A and 4B, the cancel head 20 also has a primary cancel coil 22 and a secondary cancel coil 23 wound around both arm portions of a U-shaped magnetic core 21, respectively. is covered with a case, and is embedded in the head structure 1 at a position where the detection surface 24 of the cancel head 20 is not affected by the passage of objects to be detected such as banknotes. In addition, cancel head 20-2
It is desirable that the output of the secondary coil 23 is smaller than each output of the magnetic heads 11 to 14, so when driven by the same power source, the output of the secondary coil 23 of the cancel head 20 is the output of the secondary coil of each magnetic head. coils 22 and 2 so that the coils 22 and 2 are smaller than
The number of turns of 3 has been adjusted. The bottom surface of the head structure 1 has a shape as shown in FIG. 5, and is provided with screw holes 4 and 5 for attachment to, for example, a banknote identification device. The positions and numbers of these screw holes are arbitrary.

As mentioned above, the four magnetic heads 11 to 14 and one cancel head 20 are arranged in a line and mounted on the head structure 1 to form a module and to be integrated.

Multi-channel magnetic head 1 as described above
0 is driven by a circuit as shown in FIG.
Magnetic signals M1 to M4 corresponding to the magnetic material of the object to be detected on the detection head surface are obtained in multiple channels. That is, the sine wave SW of a predetermined frequency output from the sine wave oscillator 6 is transmitted to the constant current boosters 30 to 3.
4, and the constant current boosters 30 to 34 are input to the cancel head 20 and one of the magnetic heads 11 to 14.
The next coil is energized. The output of the secondary coil 23 of the cancel head 20 is input to the differential amplifiers 41-44 via the buffer amplifier 7, and the detection signals S1-S4 of the secondary coils of the magnetic heads 11-14 are input to the differential amplifiers 41-44, respectively.
has been entered. The difference signals between the detection signals S1 to S4 obtained by the differential amplifiers 41 to 44 and the cancel signal CS are input to full wave rectifier circuits 51 to 54, respectively, and the full wave rectified signals are respectively input to band pass filters 61 to 64. input and further amplifier 7
1 to 74, magnetic signals M1 to M4 are output.

In such a configuration, the operation is shown in FIG.
The operation of the magnetic heads 11 to 14 will be described below with reference to the waveform diagrams of FIGS.

A constant current of a predetermined frequency is supplied from a constant current booster 31 to the primary coil 112 of the magnetic head 11, and a constant current of a predetermined frequency is supplied to the primary coil 112 of the magnetic head 11. Then, a detection signal S1 as shown in FIG. 7A is outputted from the secondary coil 113 of the magnetic head 11 and inputted to the differential amplifier 41. Further, the secondary coil 23 of the cancel head 20 outputs a signal corresponding to a noise component unrelated to the magnetic material of the object to be detected, and passes through the buffer amplifier 7 to the signal shown in FIG. 7B.
The signal is input to the differential amplifier 41 as a cancel signal CS as shown in FIG. The difference signal S1A as shown in FIG. 7C obtained by the differential amplifier 41 is full-wave rectified in the full-wave rectifier circuit 51 as shown in FIG. 7D and E. This full-wave rectified signal further passes through a bandpass filter 61, where only the envelope is extracted.
The amplifier 71 outputs a magnetic signal M1 corresponding to the magnetic material as shown in FIG.

In the above example, the magnetic material changes with time t, that is, the object to be detected moves relative to the multi-channel magnetic head 10, but even when the object is stationary, the object to be detected changes. The magnetic properties of a body can be obtained as a magnetic signal. In this case, one cancel head 20 is used for each of the magnetic heads 11 to 14 to remove noise components based on fluctuations in the oscillator 6, changes in temperature characteristics, etc. from the detection signal component, so magnetic detection can be performed with high detection accuracy. I can get a signal.

Magnetic signals M1 to M4 obtained as described above
is processed by the device shown in FIG. 8, for example, and outputs a denomination signal KS that determines the denomination, authenticity, etc. of the banknote. That is, the magnetic signals M1 to M4 are A/D converted by A/D converters 81 to 84 and input to the characteristic signal forming circuit 90 to form the characteristic signal CS of the detected banknote. A reference signal RS for each denomination is stored in advance in the reference signal storage means 92,
The comparison means 91 compares this reference signal RS with the obtained characteristic signal CS to obtain the denomination signal KS.
I am getting .

(Modification) In the above-described embodiment, a multi-channel magnetic head is constructed by arranging four magnetic heads, but the number of magnetic heads is arbitrary. Furthermore, in the above description, one cancel head is provided at the end of the head structure in the same direction as the detection head, but the placement position and direction are arbitrary, and the cancel signal can be generated depending on the magnetic material of the detected object. It would be better if you learned not to change. Further, in the above description, each of the primary coils of the magnetic head and the cancel head is excited by a sine wave, but the excitation does not necessarily have to be a sine wave (for example, a triangular wave).

Furthermore, in the above-mentioned embodiment, the magnetic amount and magnetic pattern are detected by the magnetic head, but an optical sensor (photodiode or optical fiber) may be disposed in the head structure, or as shown in Japanese Utility Model Application No. 61-125763. The head structure may include a head for detecting magnetic and optical signals. In the above-mentioned embodiment, an example in which the present invention is applied to a banknote identification device has been described, but the present invention is not limited to this, and it goes without saying that various applications can be made as long as the present invention is a device that detects magnetic signals.

Effects of the invention: As described above, according to the multi-channel type head of this invention, a plurality of AC excitation type heads are arranged in a line and made into a module, and a canceler head for noise removal is also integrated. The magnetic characteristics of the object to be detected can be detected as a whole without depending on the stationary state or the relative speed between the magnetic material and the magnetic head, and is not affected by noise or the like. In addition, by making the cancel head for noise removal common and making it into one module, the overall structure becomes very simple, and the detection head can be made into a module by preparing various cavities in the head structure. Therefore, detection heads can be easily combined and created according to the purpose of the head.

[Brief explanation of the drawing]

Fig. 1 is an external perspective view showing an embodiment of this invention, Fig. 2 is a diagram showing its assembly, and Figs. 3A, B and 4A, B respectively show the magnetic head and A structural diagram showing an example of a cancel head. Figure 5 is a bottom view of the head structure. Figure 6 is a bottom view of the head structure.
The figure is a block diagram showing a configuration example of a device for processing a detection signal according to this invention, FIGS. 7A to 7F are waveform diagrams showing an example of its operation, and FIG. 8 is a block diagram showing an example of a magnetic signal processing circuit. FIG. 9 is a diagram showing an example of the structure of a conventional AC excitation type magnetic head, FIG. 10 is a diagram showing an example of its use, and FIG. 11 is a diagram showing an example of the structure of a conventional DC excitation type magnetic head. DESCRIPTION OF SYMBOLS 1...Head structure, 10...Multi-channel type head, 11-14...Magnetic head, 20...
... Cancel head, 30-34... Constant current booster, 41-44... Differential amplifier, 51-54...
...Full wave rectifier circuit, 61-64...Band pass filter, 71-74...Amplifier.

Claims (1)

[Claims for Utility Model Registration] 1. A plurality of detection heads wound with a primary coil and a secondary coil and housed in a casing, and a canceller wound with a primary coil for cancelling and a secondary coil for cancelling in a casing. The head structure includes a head, and a head structure in which the plurality of detection heads are mounted so that the detection surfaces thereof are exposed, and the cancel head is embedded in the main body, and the detection surfaces of the detection heads are aligned, and the detection surfaces of the detection heads are aligned. A multi-channel head, characterized in that a plurality of detection heads and the cancel head are modularized and integrated via the head structure. 2. The multi-channel head according to claim 1, further comprising an optical sensor embedded in the detection section of the head structure.