JP2001202607A - Device and method for detecting service life of magnetic head - Google Patents

Abstract

PROBLEM TO BE SOLVED: To detect the service life of a magnetic head by highly accurately detecting the wearing state of a head part without complicating the production process of the magnetic head. SOLUTION: Concerning a service life detector 1 for a magnetic head 6, with which a magnetic gap G is formed from confronted core parts 3a and 4a having prescribed gap depth and at least one of recording and reproducing of signals is performed while sliding in contact with a magnetic medium at a pair of core parts 3a and 4a at least located while facing each other with this magnetic gap G inbetween, the wear in core parts 3a, 4a of the magnetic head 6 is detected, a pair of magnetic cores 3 and 4 having the core parts 3a and 4a are provided with a primary coil 7 for inputting the reference signal of a prescribed level and a secondary coil 8 for detecting magnetic flux generated by inputting the reference signal to the primary coil 7, the gap of the core part 4a in the magnetic core 4 wound with the secondary coil 8 is formed shallower than the gap of the core part 3a in the magnetic core 3 wound with the primary coil 7, and it is detected from the level of a detecting signal detected by the secondary coil 8 that the quantity of head wearing in the core parts 3a and 4a becomes a prescribed level.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic head for performing at least one of recording and reproducing signals on a magnetic medium. More specifically, the present invention relates to an apparatus and method for detecting the life of a magnetic head for detecting the wear amount of a head portion of the magnetic head.

[0002]

2. Description of the Related Art There is a magnetic head which performs at least one of recording and reproducing of magnetic data on a magnetic stripe of a magnetic card such as a cash card or a credit card. This magnetic head includes a head portion in which a pair of magnetic cores having the same gap depth face each other with a magnetic gap therebetween. The head unit performs at least one of recording and reproduction of magnetic data while sliding on the magnetic card. Here, since the head portion comes into sliding contact with the magnetic card, the head portion will be worn by use for a long time. This wear may cause a defect in recording or reproduction of magnetic data.

In order to prevent such a defect from occurring, various wear detecting devices have been developed to detect the wear of the head portion.

[0004] For example, as shown in FIG.
A magnetic head 105 has been developed in which a spacer 101 is laminated on the side of the magnetic head 105 and a single electric path 103 is formed by the spacer 101 so as to pass through the side of the head 102 (see JP-A-9-7135). . This spacer 10
The side portion of the head section 102 is a life detecting section 104. The width h of the life detecting unit 104 in the wear direction is set to be smaller than the effective gap depth d, which is the operable limit of the magnetic gap.

According to the magnetic head 105, the life detecting unit 104 is worn before the head unit 102 reaches the effective gap depth d. Then, the electric path 103 of the spacer 101 is cut off due to wear of the life detecting unit 104, and this is detected by the life detecting circuit 106. As a result, it is detected that the magnetic head 105 has reached its wear limit, that is, the life of the magnetic head 105, so that the magnetic head 105 can be replaced before a failure occurs in recording or reproducing magnetic data.

A reference signal is input to a recording coil wound around a recording core, and a magnetic flux output from the reproducing coil wound around the reproducing core is detected. A life detecting device for judging the amount of wear from the magnitude of the detected signal has been developed (JP-A-11-8611).
244).

Further, there has been proposed a wear detecting device for estimating the wear amount of the head portion by accumulating the time or the number of times the magnetic card slides on the head portion.

[0008]

However, in the magnetic head 105 having the life detecting section 104 described above, the length h of the life detecting section 104 in the wear direction is determined by the effective gap depth d.
Must be smaller than that of the magnetic head 10.
In the case where the gap depth d is different for each 5, the width h of the life detecting unit 104 in the wear direction must be changed in accordance with the different effective gap depth d. Further, it is difficult to form a pattern of the life detecting unit 104 at a portion where the core halves abut. For these reasons, the manufacturing process of the magnetic head 105 is complicated, and it is difficult to reduce the manufacturing cost.

Further, in the life detecting device which determines the wear amount based on the detection signal from the reproducing coil, the gap depth between the pair of magnetic cores facing each other is set to be equal. As described above, the variation of the output voltage corresponding to the actual wear amount with respect to the constant detection voltage is large and the accuracy is not good. In other words, at the time of manufacturing each magnetic core, the gap depth of the recording core and the reproducing core is equal, but if the height of the recording core and the reproducing core is slightly different at the time of abutting, the head surface may be reduced. Is flattened by polishing, so that when the magnetic head is completed, the gap depth is different between the recording core and the reproducing core. Thereby, when the detection signal taken out from the reproducing coil has a certain value, the actual wear amount with respect to this value may vary greatly.
The accuracy is not good.

Furthermore, in a wear detecting device that accumulates the time and the number of times of sliding contact between the magnetic card and the head, the wear condition changes depending on the environment in which the head is used.

Therefore, the present invention provides a magnetic head life detecting device capable of detecting the life of the magnetic head by detecting the wear state of the head portion with high accuracy without complicating the manufacturing process of the magnetic head. It is intended to provide such a method.

[0012]

Means for Solving the Problems In order to achieve the above object, the inventors of the present invention have conducted intensive studies, and as a result, the secondary coil has been formed with respect to the gap depth of the core portion in the magnetic core wound with the primary coil. When the gap depth of the core portion in the wound magnetic core is formed short, the detection signal generated in the secondary coil by inputting the reference signal to the primary coil is shown in FIG. It was found that the dispersion was very small as shown in FIG.

[0013] Claim 1 was invented based on such knowledge.
According to the invention described above, a magnetic gap is formed by opposing core portions having a predetermined gap depth, and at least a pair of core portions opposed to each other with the magnetic gap interposed therebetween are in sliding contact with a magnetic medium to record and reproduce signals. In a magnetic head life detecting device for detecting wear in a core portion of a magnetic head that performs at least one of the following, a primary coil in which a reference signal of a predetermined magnitude is input to a pair of magnetic cores having a core portion; A secondary coil for detecting a magnetic flux generated when a signal is input to the primary coil, and a magnetic coil having the secondary coil wound with respect to the gap depth of the core portion of the magnetic core wound with the primary coil. The gap depth of the core portion of the core is made shorter, and the amount of head wear in the core portion becomes a predetermined value depending on the magnitude of the detection signal detected by the secondary coil. And to detect the.

According to a fifth aspect of the present invention, a magnetic gap is formed by opposed core portions having a predetermined gap depth, and at least a pair of core portions opposed to each other with the magnetic gap interposed therebetween and a magnetic medium. A method for detecting the life of a magnetic head that detects abrasion in a core portion of a magnetic head that performs sliding contact and performs at least one of signal recording and reproduction,
A magnetic core in which a primary coil and a secondary coil are respectively provided on a pair of magnetic cores having a core portion, and a secondary coil is wound with respect to a gap depth of the core portion in the magnetic core around which the primary coil is wound. The gap depth of the core portion is shortened, and a reference signal having a predetermined magnitude is input to the primary coil, while the secondary coil detects a magnetic flux generated when the reference signal is input to the primary coil, and detects a secondary magnetic flux. The magnitude of the detection signal detected by the coil is used to detect that the head wear amount in the core has reached a predetermined magnitude.

Therefore, when detecting the amount of wear of the head of the core portion, a reference signal for detecting the amount of wear is input to the primary coil. Thereby, a magnetic flux is generated in the magnetic core around which the primary coil is wound. This magnetic flux generates a current in the magnetic core around which the secondary coil is wound and in the secondary coil. Here, since the current value has a correlation with the area of the primary core and the secondary core facing each other, the current can be detected as a detection signal to determine the head wear amount of the core portion. That is, as shown in FIG. 8A, the detection signal from the secondary coil decreases as the wear amount of the core increases.
Therefore, a threshold value of the detection signal is set in advance, and when the detection signal becomes smaller than the critical value, it is detected that the head wear amount has reached a predetermined value.

Since the gap depth of the core portion of the magnetic core wound with the secondary coil is shorter than the gap depth of the core portion of the magnetic core wound with the primary coil, each core is formed. The gap depth of the core portion of the magnetic core wound with the secondary coil is larger than the gap depth of the core portion of the magnetic core wound with the primary coil with respect to the gap depth of the core portion of the magnetic core wound with the primary coil. Thus, the variation in the actual head wear amount with respect to the predetermined value of the detection signal can be reduced. Therefore, the variation of the actual head wear amount with respect to the magnitude of the detection signal detected by the secondary coil is shown in FIG.
, The detection accuracy of the head wear amount can be improved.

According to a second aspect of the present invention, in the magnetic head life detecting device of the first aspect, a step is formed in a core portion of the magnetic core around which the secondary coil is wound, and the primary coil is wound. It is formed to be shorter than the gap depth of the core portion in the rotated magnetic core. Therefore,
A state where the gap depth of the core portion of the magnetic core wound with the secondary coil is shorter than the gap depth of the core portion of the magnetic core wound with the primary coil can be easily realized.

Further, the invention according to claim 3 is the same as the claim 1.
Or the life detecting device for a magnetic head according to 2, wherein the pair of magnetic cores are a recording core having a wide core width, a reproducing core and a spacer facing the recording core and having a core width narrower than the recording core, and The secondary coil is a recording coil wound around a recording core, and the secondary coil is a reproduction coil wound around a reproduction core.

Therefore, it is possible to detect the amount of wear of the core portion of the magnetic head in which the pair of magnetic cores are the recording core and the reproducing core. Further, since the recording coil and the reproduction coil are provided in advance on the magnetic head to be inspected, existing coils can be used as they are for detecting the amount of wear. In addition, since a so-called wide write / narrow read magnetic head is used, the head is less affected by uneven wear, and the head wear detection accuracy can be improved.

Further, the invention according to claim 4 is the same as the invention according to claim 3.
In the device for detecting the life of a magnetic head as described above, the recording coil can be switched and connected to a recording circuit for recording magnetic data on a magnetic medium by a pair of magnetic cores,
The reproducing coil can be switched and connected to a reproducing circuit for reproducing magnetic data of a magnetic medium by a pair of magnetic cores. Therefore, each coil wound around each core can be used by switching between reading and writing of magnetic data of the magnetic medium and detection of head wear.

[0021]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The configuration of the present invention will be described below in detail based on an example of an embodiment shown in the drawings. 1 to 3 show an embodiment of the life detecting device 1 for the magnetic head 6 according to the present invention. In the present embodiment, the life detecting device 1 is a CD
(Cash dispenser) The case where it is incorporated in a magnetic head 6 such as a machine is described.

In the device 1 for detecting the life of the magnetic head 6, a magnetic gap G is formed by opposing core portions 3a and 4a having a predetermined gap depth, and at least a pair of opposing opposing members are arranged with the magnetic gap G interposed therebetween. The sliding surface formed by the core portions 3a and 4a is in sliding contact with a magnetic medium such as a magnetic card, and detects wear on the core portions 3a and 4a of the magnetic head 6 that performs at least one of signal recording and reproduction. . In the life detecting device 1, a primary coil 7 to which a reference signal of a predetermined magnitude is input to one of the pair of magnetic cores 3 and 4 having the core portions 3a and 4a.
And a secondary coil 8 for detecting a magnetic flux generated when a reference signal is input to the primary coil 7 to the other magnetic core 4. The gap depth D of the core 3a in the magnetic core 3 around which the primary coil 7 is wound.
The gap depth D2 of the core portion 4a of the magnetic core 4 around which the secondary coil 8 is wound is smaller than that of the secondary coil 1.
Furthermore, the magnitude of the detection signal detected by the secondary coil 8 detects that the head wear amount in the core portions 3a and 4a has reached a predetermined magnitude. For this reason, the gap depth D2 of the core portion 4a on the secondary coil 8 side is formed smaller than the gap depth D1 of the core portion 3a on the primary coil 7 side. Variations in the actual head wear amount with respect to the signal magnitude can be reduced to improve the detection accuracy.

As the head for the magnetic card reader, the magnetic head 6 has a recording core 3 having a substantially U-shaped cross section and a primary coil 7 wound thereon, and a recording core 3 having a substantially U-shaped cross section. A so-called wide write / narrow read magnetic head having a reproducing core 4 having a smaller core width and wound with a secondary coil 8 is used. In this case, 1
A recording coil can be used as the secondary coil 7 and a reproducing coil can be used as it is as the secondary coil 8. For this reason,
It is less likely to be affected by uneven wear, and the detection accuracy of head wear can be improved.

The reproducing core 4 is located within the core width of the recording core 3. The reproducing core 4 abuts the recording core 3 with a gap spacer 2 forming a magnetic gap G interposed therebetween so as to form a loop-shaped magnetic path with the recording core 3. On both sides of the reproducing core 4 in the core width direction, the side cores 11, 1 are sandwiched by the laminated spacers 10, 10.
1 is arranged. The side cores 11 are abutted on both side ends of the recording core 3 with the gap spacer 2 interposed therebetween.

Here, the magnetic cores 3 and 4 are formed by laminating a core formed in a predetermined shape using a magnetic material such as permalloy, sendust, ferrite, or a plurality of thin plate-shaped metal magnetic materials. A core or the like having a core width of? A non-magnetic material is used for each of the spacers 2, 10, and 10.

A step is formed on the magnetic gap G side of the core 4a of the reproducing core 4. This allows
The gap depth D2 of the core 4a of the reproducing core 4 can be smaller than the gap depth D1 of the core 3a of the recording core 3.

In this embodiment, the primary coil 7 uses a recording coil for recording normal data, and the secondary coil 8 uses a reproduction coil for reproducing normal data. ing. The recording coil can be switched and connected to a recording circuit (not shown) for recording magnetic data on a magnetic medium by the pair of magnetic cores 3 and 4. Further, the reproducing coil can be switched and connected to a reproducing circuit for reproducing magnetic data of a magnetic medium by the pair of magnetic cores 3 and 4.

Input means 12 for inputting a reference signal is connected to the primary coil 7 as shown in FIG. The input means 12 includes a bridge circuit 13 connected to the primary coil 7 and an AC 12 connected to the bridge circuit 13.
It includes a constant voltage power supply 14 of volts, a first resistor 16 provided between the bridge circuit 13 and the ground 15, and a resistance switching circuit 17 provided in parallel with the first resistor 16.
Further, the resistance switching circuit 17 includes a second resistor 18 and a transistor 19 provided in parallel with the first resistor 16, a switch 20 connected to the base B of the transistor 19,
A switching power supply 21 connected to the switch 20 is provided. Then, the current from the constant voltage power supply 14 reaches the ground 15 via the bridge circuit 13 and the first resistor 16.

Here, when the switch 20 is turned on, the conduction between the collector C and the emitter E of the transistor 20 is conducted, so that the resistance value between the bridge circuit 13 and the ground 15 is the first resistor 16 and the first resistor 16. The combined value of the two resistors 18 is smaller than the resistance value of the first resistor 16. On the other hand, when the switch 20 is turned off, the connection between the collector C and the emitter E of the transistor 20 is disconnected, so that the resistance between the bridge circuit 13 and the ground 15 is the resistance of only the first resistor 16. Becomes Thus, when the switch 20 is on, the resistance value is small and the voltage applied to the bridge circuit 13 is large, so that the current input to the primary coil 7 increases. On the other hand, when the switch 20 is off, the resistance value is large and the voltage applied to the bridge circuit 13 is small.
The current input to the primary coil 7 decreases.

The secondary coil 8 is provided with wear detecting means 9 for detecting that the amount of head wear in the core portions 3a, 4a has reached a predetermined level based on the magnitude of the detection signal detected by the secondary coil 8. It is connected. This wear detecting means 9
Is an amplifier 22 for amplifying an output signal from the secondary coil 8
A peak hold 23 for detecting a peak value of an amplified signal from the amplifier 22, a voltmeter 24 for measuring an output from the peak hold 23, and a head wear amount having a predetermined magnitude based on a measurement result of the voltmeter 24. And determination means 25 for determining whether or not the condition has been reached. The judging means 25 compares the measured voltage from the voltmeter 24 with a predetermined critical voltage L, and judges that the head wear amount has reached a predetermined magnitude when the measured voltage is lower than the critical voltage L. It outputs the result. Specifically, for example, the central processing unit and the RO
It is composed of a computer having storage means such as M and RAM and input / output means such as I / O ports, or a sequence circuit.

In the wear detecting means 9, the current generated in the secondary coil 8 by the magnetic flux flowing through the reproducing core 4 is amplified by the amplifier 22. Then, the peak value of the amplified signal is detected by the peak hold 23. The detected value is measured by the voltmeter 24. The measurement result of the voltmeter 24 is input to the judgment means 25 and compared with a preset critical voltage L.

Here, as shown in FIG. 8A, the detected voltage from the secondary coil 8 decreases as the head wear increases and the gap depth D2 of the core portion 4a decreases. This is because if the head wear amount is large, a loop-shaped magnetic path is less likely to be generated, and the magnetic flux is reduced. Therefore, the maximum amount of head wear within a range in which the magnetic head 6 can operate is set as a predetermined value, and the detection voltage at that time is set as the critical voltage L. Thus, if the measured voltage from the voltmeter 24 is higher than the critical voltage L, it can be determined that the head wear amount is smaller than the predetermined value. On the other hand, the measured voltage from the voltmeter 24 is the critical voltage L
If smaller, it can be determined that the head wear amount is larger than a predetermined amount. Further, in this case, an alarm means (not shown) such as lighting of a lamp is operated in order to notify the outside that the magnetic head 6 needs to be replaced. It is needless to say that the critical voltage L varies depending on the setting of the usable range of the magnetic head 6, the magnitude of the reference signal, and the like.

A resistor 26 is interposed between the bridge circuit 13 and the primary coil 7 and between the secondary coil 8 and the amplifier 22, respectively. Therefore, the reference signal from the bridge circuit 13 can be sufficiently reduced before being input to the amplifier 22, so that even if the output of the bridge circuit 13 is larger than the rating of the amplifier 22,
2, the detection signal can be amplified.

When magnetic data is recorded on a magnetic card by the magnetic head 6 equipped with the above-described life detecting device 1, the switch 20 is turned on and a current flows through the second resistor 18, so that a large current flows through the bridge circuit 13. Apply voltage. As a result, a large current can flow from the bridge circuit 13 to the primary coil 7, so that a large number of magnetic fluxes can be generated in the recording core 3 and recording can be performed on the magnetic card slidably in contact with the head unit 5. When the magnetic data of the magnetic card is reproduced by the magnetic head 6, the magnetic card is brought into sliding contact with the reproducing core 4 to generate a magnetic flux. Then, the current generated in the secondary coil 8 is amplified by the amplifier 22. The amplified signal is transmitted to a reproduction circuit (not shown) to perform reproduction.

On the other hand, when the life detecting device 1 is operated to check the life of the head, the magnetic card is removed from the magnetic head 6. Then, the switch 20 is turned off and a small voltage is applied to the bridge circuit 13 so that no current flows through the second resistor 18. This allows a small current of an AC constant voltage to flow from the bridge circuit 13 to the primary coil 7, so that a small number of magnetic fluxes can be generated in the recording core 3. This magnetic flux flows to the reproducing core 4 and
A current is generated in the next coil 8. This current is supplied to the amplifier 22
And the peak value is maintained in the peak hold 23.

The peak value is measured by the voltmeter 24 to obtain a detection signal, and the judgment means 25 compares the signal with the critical voltage L. Thereby, it is possible to detect whether or not the wear of the head portion 5 is larger than a predetermined size. Here, the primary coil 7
The secondary coil 8 is larger than the gap depth D1 of the side core portion 3a.
Since the gap depth D2 of the side core portion 4a is smaller,
Variations in the actual head wear amount with respect to the magnitude of the detection signal can be reduced to improve the detection accuracy.

If the wear of the head portion 5 is larger than a predetermined size, an alarm is activated to warn the outside that the head needs to be replaced.

According to the life detecting device 1 of the present embodiment, it is not necessary to add a new component to the magnetic head 6 itself.
Since only a slight processing of forming the step and the addition of the wear detecting means 9 and the like are required, an increase in cost can be minimized.

According to the life detecting device 1 of this embodiment, 1
Since the reference signal input to the secondary coil 7 is a constant AC voltage, the output signal from the secondary coil 8 can be stabilized. For this reason, the accuracy of the wear measurement can be improved, and the determination that the head has reached the end of its life can be made with high accuracy.

Further, according to the life detecting device 1 of the present embodiment, the voltage applied to the bridge circuit 13 is
, The number of magnetic fluxes generated in the recording core 3 can be switched between a large number and a small number. Thereby, when recording is performed on a magnetic card, a large number of magnetic fluxes can be generated to perform recording with a large magnetic force. On the other hand, when the wear of the head section 5 is detected, a small amount of magnetic flux is generated to generate a small current in the secondary coil 8 via the reproducing core 4. Here, since the amplifier 22 is for amplifying a small current detected from the magnetic card, the amplifier 22 is saturated and cannot be amplified when a large current used for recording is input. Since the current for detecting wear generated in the secondary coil 8 is reduced,
Amplification can also be performed using 2. Therefore, since one amplifier 22 can be used for both reproducing magnetic data and detecting wear, an increase in the number of parts can be suppressed.

The above embodiment is an example of a preferred embodiment of the present invention, but the present invention is not limited thereto, and various modifications can be made without departing from the gist of the present invention. For example, in the present embodiment, the core part 4 of the reproducing core 4
By forming a step on the side of the magnetic gap G, the gap depth D2 of the core 4a of the reproducing core 4 is smaller than the gap depth D1 of the core 3a of the recording core 3. The present invention is not limited to this. For example, as shown in FIG. 4, a corner of the core portion 4a of the reproducing core 4 on the magnetic gap G side is chamfered, or as shown in FIG.
The head surface may be polished in a state where the lower surface of the core portion 4a of the reproducing core 4 is abutted so as to be higher than the lower surface of the core portion 3a. In any case, the gap depth D2 of the core portion 4a of the reproducing core 4 can be smaller than the gap depth D1 of the core portion 3a of the recording core 3, so that the detection accuracy of the head wear amount is improved. be able to.

In this embodiment, one amplifier 22 is used for reproducing magnetic data and for detecting wear by connecting the resistance switching circuit 17 to the bridge circuit 13 and switching the magnitude of the voltage output from the bridge circuit 13. However, the present invention is not limited to this. The output voltage is kept constant at a large value without connecting the resistance switching circuit 17 to the bridge circuit 13, and the magnetic data reproducing amplifier and the wear detecting amplifier are separately provided. May be provided. In this case, since the output voltage from the bridge circuit 13 is always large, recording on the magnetic card becomes possible, and the current generated in the secondary coil 8 when abrasion is detected increases. Therefore, by using an amplifier having a rating higher than that of the reproducing amplifier 22 as the abrasion detecting amplifier 22, a large current for abrasion detection can be amplified to detect abrasion.

In this embodiment, the reference signal input to the primary coil 7 is an AC constant voltage. However, the present invention is not limited to this. In addition to a signal for recording magnetic data, a detection signal from the secondary coil 8 may be used. May be another reference signal, for example, an AC constant current, a DC constant voltage, or a DC constant current. When the AC constant current is used, the constant current circuit becomes more complicated than the constant voltage circuit, but the stability of the input current is increased irrespective of the decrease in the gap depth of the head portion 5, so that the detection of wear can be performed with high accuracy. be able to.

Further, in the present embodiment, the life detecting device 1 is combined with the write / read head having the recording core 3 and the reproducing core 4, so that the primary coil 7 and the secondary coil 8 are formed as separate coils. However, the present invention is not limited to this, and the life detecting device 1 can be incorporated in a magnetic head 6 having only one coil 27, such as a recording-only head or a reproduction-only head shown in FIG. In this case, a lead wire 28 is connected in the middle of one coil 27. Then, the primary coil 7 and the secondary coil 8 can be divided with the lead wire 28 as a boundary. In this embodiment, when the primary coil 7 is energized, the end 27 of the coil 27 on the primary coil 7 side is used.
a and the end 28a of the lead wire 28. Also,
When power is supplied to the secondary coil 8, power is supplied between the end 27 b of the coil 27 on the secondary coil 8 side and the end 28 a of the lead wire 28. According to this embodiment, the wear of the magnetic head 6 can be detected with high accuracy.

In the embodiment shown in FIG. 6, the lead wire 28 is used when the life detecting device 1 is incorporated in the magnetic head 6 having only one coil 27 like a recording-only head or a reproduction-only head. , But not limited to this
A separate coil 8 may be newly wound as shown in FIG. Then, for example, the original coil 27 is replaced with the primary coil 7.
By setting the new coil as the secondary coil 8 or vice versa, the wear of the head 5 can be detected. Further, a recording circuit for detecting the life may be separately provided.

Further, in each of the embodiments described above, the life detecting device 1 is incorporated in the magnetic head 6 of the CD machine. However, the present invention is not limited to this, and a single measuring device 29 can be used. For example, as shown in FIG. 1, it is assumed that the measuring device 29 includes the input unit 12 and the wear detecting unit 9. And
For example, the life detecting device 1 is connected to the connector of the magnetic head 6 at the time of maintenance and inspection such as a regular cleaning of a CD machine installed in a bank. At this time, the bridge circuit 13 of the input means 12 is connected to the primary coil 7 of the magnetic head 6 and the amplifier 22 of the wear detecting means 9 is connected to the secondary coil 8.

After connecting these, the input means 1
2 is operated to transmit a reference signal to the magnetic head 6. Further, the output signal from the magnetic head 6 is detected by the wear detecting means 9 to determine the wear. According to this embodiment, head wear can be detected without replacing the magnetic head 6 even for the magnetic head 6 having no head wear detection function. It is possible to prevent the occurrence of read / write failure of the magnetic card due to wear of the head during use of a CD machine or the like in advance.

[0048]

(Embodiment) A magnetic head 6 in which the gap depth D2 of the core portion 4a of the reproducing core 4 is smaller than the gap depth D1 of the core portion 3a of the recording core 3 shown in FIGS.
In the above, the coil of the recording core 3 was a primary coil 7 and the coil of the reproducing core 4 was a secondary coil 8. The gap depth D2 of the core portion 4a of the reproducing core 4 was set to 0.4 mm. A DC constant current (fixed at 30 mA) and a DC constant voltage (fixed at 4 V) are used as reference signals for the primary coil 7.
And gave.

Then, the output voltage from the secondary coil 8 was measured while changing the head wear amount stepwise within the range of 0 to 0.4 mm. FIG. 8A shows the result as a relationship between the gap depth D2 of the core portion 4a of the reproducing core 4 and the output voltage from the secondary coil 8. As shown in the figure, the variation in the correspondence between the gap depth D2 and the output voltage is small,
Actual gap depth D when a predetermined critical voltage L is reached
The possible range of 2 became narrow. Therefore, the accuracy of the determination of the head wear amount was high.

(Comparative Example) The gap depth D2 of the core of the reproducing core is larger than the gap depth D1 of the core of the recording core.
In the magnetic head having a larger size, the coil of the recording core was a primary coil and the coil of the reproducing core was a secondary coil. Further, the gap depth D2 of the core portion of the reproducing core was set to 0.5 mm. A DC constant current (fixed at 30 mA) and a DC constant voltage (fixed at 4 V) were supplied to the primary coil as reference signals.

Then, the output voltage from the secondary coil was measured while changing the head wear amount stepwise within the range of 0 to 0.5 mm. FIG. 8 shows the relationship between the gap depth D2 of the core portion of the reproducing core and the output voltage from the secondary coil.
It is shown in (B). As shown in the figure, the correspondence between the gap depth D2 and the output voltage varies greatly, and the range of the actual gap depth D2 when the predetermined critical voltage L is reached is widened. Therefore, the accuracy of the determination of the head wear amount was low.

Therefore, it has been found that the accuracy of life detection can be improved by using the magnetic head 6 of this embodiment as compared with the case of using the conventional magnetic head.

[0053]

As is apparent from the above description, according to the magnetic head life detecting device of the first aspect and the magnetic head life detecting method of the fifth aspect, the magnetic core having the primary coil wound thereon. Since the gap depth of the core portion of the magnetic core around which the secondary coil is wound is shorter than the gap depth of the core portion, the variation of the actual head wear amount with respect to the predetermined value of the detection signal is reduced. be able to. For this reason, the detection accuracy of the head wear amount can be improved. In addition, since there is no need to change or add new components and only to add a small amount of additional processing and a detection circuit, it is possible to minimize an increase in cost.

According to the apparatus for detecting the life of a magnetic head according to claim 2, the core of the magnetic core wound with the secondary coil corresponds to the gap depth of the core portion of the magnetic core wound with the primary coil. A state in which the gap depth of the portion is shortened can be easily realized.

Further, according to the magnetic head life detecting device of the third aspect, since the secondary coil is a reproducing coil wound around the reproducing core, a pair of magnetic cores are used for recording. It is possible to detect head wear of the magnetic head, which is the core and the reproducing core. Further, since the recording coil and the reproduction coil are provided in advance on the magnetic head to be inspected, existing coils can be used as they are for detecting the amount of wear. For this reason, the life detecting device can be simplified.

In addition, since a wide write / narrow read magnetic head can be used, the head is less affected by uneven wear and the head wear detection accuracy can be improved.

According to the magnetic head life detecting device of the present invention, each coil wound around each core is used by switching between reading and writing of magnetic data of the magnetic medium and detection of the wear amount of the head. be able to. For this reason, even if the magnitude of the signal for wear detection and the magnitude of the signal for recording / reproduction are completely different, and even if the magnitudes of the current and voltage to be processed are completely different, each coil can be used in common. The wear can be detected with high accuracy without damaging the wear.

[0058]

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating an embodiment of a magnetic head life detecting device according to the present invention.

FIGS. 2A and 2B show an embodiment of a magnetic head used in a life detecting device, wherein FIG. 2A is a perspective view and FIG. 2B is a plan view.

FIG. 3 is a front view showing a main part of each magnetic core.

FIG. 4 is a front view showing another embodiment of the magnetic core.

FIG. 5 is a front view showing another embodiment of the magnetic core.

FIG. 6 is a front view showing another embodiment of the magnetic head.

FIG. 7 is a front view showing another embodiment of the magnetic head.

FIG. 8 is a graph showing a relationship between a gap depth D2 of a core portion of a reproducing core and an output voltage from a secondary coil;
(A) In the case of the present invention in which the gap depth D2 is smaller than the gap depth D1 of the core portion of the recording core, (B) shows the gap depth D2 of the core portion of the recording core.
This is a larger case than before.

9A and 9B show a conventional life detecting device, wherein FIG. 9A is a perspective view of a magnetic head provided with the life detecting device, and FIG. 9B is a side view thereof.

[Explanation of symbols]

REFERENCE SIGNS LIST 1 magnetic head life detecting device 3 recording core (magnetic core wound with primary coil) 3a core portion in magnetic core wound with primary coil 4 reproduction core (magnetic core wound with secondary coil) 4a Core part in magnetic core wound with secondary coil 6 Magnetic head 7 Recording coil (primary coil) 8 Reproduction coil (secondary coil) D1 Gap depth of core part in magnetic core wound with primary coil D D2 Gap depth of core in magnetic core wound with secondary coil G Magnetic gap

Claims (5)

[Claims] 1. A magnetic gap is formed by opposed core portions having a predetermined gap depth, and at least a pair of the core portions opposed to each other with the magnetic gap interposed therebetween are in sliding contact with a magnetic medium to record and record signals. In a magnetic head life detecting device for detecting wear in the core portion of a magnetic head performing at least one of reproductions, a primary coil in which a reference signal of a predetermined magnitude is input to a pair of magnetic cores having the core portion And a secondary coil for detecting a magnetic flux generated when the reference signal is input to the primary coil, wherein the gap depth of the core portion in the magnetic core around which the primary coil is wound is determined with respect to the gap depth. The above-mentioned gap depth of the core portion in the magnetic core wound with the secondary coil is formed to be short, and the magnitude of the detection signal detected by the secondary coil causes the core portion to have a smaller thickness. A life detecting device for a magnetic head, wherein the head wear amount in the magnetic head is detected to be a predetermined amount. 2. A step portion is formed in a core portion of the magnetic core around which the secondary coil is wound, and the core portion of the magnetic core around which the primary coil is wound is formed to be shorter than the gap depth. 2. The apparatus for detecting the life of a magnetic head according to claim 1, wherein: 3. The pair of magnetic cores are a recording core having a wide core width, a reproducing core and a spacer facing the recording core and having a core width narrower than the recording core, and the primary coil is provided with: 3. The recording coil wound around a recording core, and the secondary coil is a reproduction coil wound around the reproduction core.
A device for detecting the life of a magnetic head according to the above. 4. The recording coil is switchably connectable to a recording circuit for recording magnetic data on the magnetic medium by the pair of magnetic cores, and the reproducing coil is connected to the recording circuit by the pair of magnetic cores. 4. The apparatus according to claim 3, wherein the apparatus is switchable and connectable to a reproducing circuit for reproducing magnetic data of a magnetic medium. 5. A magnetic gap is formed by opposed core portions having a predetermined gap depth, and at least a pair of the core portions opposed to each other with the magnetic gap interposed therebetween are in sliding contact with a magnetic medium to record and record signals. In a magnetic head life detecting method for detecting wear in the core portion of a magnetic head that performs at least one of reproduction, a primary coil and a secondary coil are provided on a pair of magnetic cores having the core portion, respectively. The gap depth of the core portion in the magnetic core wound with the secondary coil is formed to be shorter than the gap depth of the core portion in the magnetic core wound with the secondary coil, and the primary coil has a predetermined size. While the reference signal is input, the secondary coil detects the magnetic flux generated when the reference signal is input to the primary coil, and the magnetic flux is detected by the secondary coil. A method for detecting the life of a magnetic head, comprising detecting, based on the magnitude of a detection signal, that the head wear amount in the core portion has reached a predetermined magnitude.