JP2004164708A - Rotary head device, and recording and reproducing device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a rotary head device, and a recording and reproducing device for reducing variations in a mutual inductance of a rotary transformer and also to prevent the complexity of a gap adjusting process and a device structure and the adverse effect such as cost increase caused therewith. <P>SOLUTION: In a recording and reproducing device 1, a magnetic head and its reproducing circuit are mounted on a rotating drum 5 to connect the reproducing circuit to a rotary coil of a rotary transformer 10 and influences on a mutual inductance of the rotary transformer 10 from an inductance component of the magnetic head is perfectly cut. Alternatively, the magnetic head is composed by using an resistive effect element or a huge magneto-resistive effect element almost having no inductance component, and the magnetic head is connected to the rotary coil of the rotary transformer 10. Thereby, the gap can be adjusted while accurately measuring only the mutual inductance of the rotary transformer 10, and it is not necessary to disconnect electrical connection of the rotary coil with the magnetic head and the reproducing circuit. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a technique for reducing variations in mutual inductance of a rotary transformer arranged in a drum in a rotary head device and a recording / reproducing device using the same.
[0002]
[Prior art]
2. Description of the Related Art In a recording / reproducing apparatus that records desired information on a tape-shaped recording medium (such as a magnetic tape) or reproduces the recorded information as an electric signal, a rotary head device including a magnetic head and a rotary transformer (a so-called rotary drum device) And a rotary drum, a fixed drum, a rotary transformer, a magnetic head, and the like.
[0003]
For example, in a rotary head device a shown in FIG. 9 (only the main part thereof is shown), a rotary side portion (rotor core and coil) br of a rotary transformer is attached to a rotary drum c, and its winding coil is a flexible cable. Are connected to the magnetic head. The fixed side portion (stator core and coil) bs of the rotary transformer is attached to a fixed drum d, and a reproduction signal is transmitted to a circuit unit outside the drum via a flexible cable or the like.
[0004]
The rotating shaft e is fixed to the rotating drum c by press-fitting, and the bearing f for the rotating shaft e is provided on the fixed drum d side. It is necessary to adjust a gap (gap) between the rotating side portion br and the fixed side portion bs so that an appropriate mutual inductance value can be obtained.
[0005]
The method of assembling the rotary head device a will be briefly described as follows using the upper drum rotary type as an example.
[0006]
(1) Assemble each part of the lower drum and the upper drum.
(2) Press the rotary shaft of the upper drum into the bearing of the lower drum. At this time, the insertion amount is adjusted so that the mutual inductance between the rotating side portion and the fixed side portion of the rotary transformer becomes an appropriate value.
(3) After the gap adjustment in (2), fix the rotating shaft (for example, when the bearing and the rotating shaft are fitted with a gap, pressurize the plate with a leaf spring or the like and fix the shaft with a ring. .).
[0007]
When assembling the upper and lower drums, if it is possible to directly measure only the mutual inductance of the rotary transformer, the rotating shaft of the upper drum is gradually pressed into the bearing of the lower drum while observing the measured values. This is simple because press-fitting may be stopped when the required mutual inductance value is obtained.
[0008]
However, in the above (1), since the rotating side portion of the rotary transformer is connected to the magnetic head (inductive head) in the upper drum, a value including the inductance component of the head is measured. The mutual inductance of the rotary transformer cannot be measured accurately.
[0009]
Then, in order to avoid such inconvenience, the following forms are known.
[0010]
(A) Form in which the insertion amount in (2) is determined so that the gap in the rotary transformer becomes a predetermined value.
(B) A mode in which a member (flange) including a rotating shaft and a bearing is interposed between the rotating drum and the fixed drum.
[0011]
First, in (A), the relationship between the mutual inductance of the rotary transformer and the gap is measured in advance to determine a gap value at which an appropriate mutual inductance is obtained. The upper drum should be pressed into the lower drum so that the desired value can be obtained.
[0012]
In this embodiment, it is assumed that the rotor coil of the rotary transformer and the magnetic head are electrically connected, and the gap is adjusted without disconnecting the two. However, the mutual inductance of the rotary transformer is further improved in accuracy. Various methods are known as a method (for example, see Patent Document 1).
[0013]
For example, the inductance (secondary inductance) of the rotary part of the rotary transformer is measured first, and the target total inductance is determined based on the result. Then, the actual measured value of the total inductance at the time of press-fit adjustment is obtained, and immediately before this becomes the target total inductance, the amount of press-fit movement is corrected to determine the target total inductance as the final target, and the measured value becomes the final target value. Pressing is terminated when it reaches.
[0014]
In the above (B), by using the flange, it is possible to measure only the mutual inductance of the rotary transformer in a state where the rotary side portion of the rotary transformer and the magnetic head attached to the rotary drum are not electrically connected. It is.
[0015]
For example, as shown in the rotary head device g of FIG. 10, the fixed side portion bs of the rotary transformer is mounted on a fixed drum d, and the rotary side portion br of the rotary transformer is mounted and fixed to a flange h. .
[0016]
A direct bearing is fixed to a bearing portion i provided on the flange h, and a rotary side portion br of the rotary transformer is fixed to the flange h. Then, the rotor coil j of the rotary transformer is soldered to the head contact k.
[0017]
A head unit 1 including a magnetic head is attached to a rotating drum c, and its terminal is connected by being elastically pressed against the head contact k, and a reproduction signal from the head unit l is rotated by a rotary transformer. It is transmitted from the side part br to the fixed part bs.
[0018]
In addition, other components of the rotary head device g include a motor unit m, a ring n for balance adjustment, a cover o, and the like.
[0019]
The method of assembling the rotary head device g will be briefly described below.
[0020]
(1) Assemble the flange h.
(2) The shaft p of the direct bearing of the flange h is pressed into the hole q formed in the fixed drum d to unite the flange h with the fixed drum d. At this time, while measuring the mutual inductance of the rotary transformer, the insertion amount of the shaft p is controlled so that the measured value becomes an appropriate value.
(3) The rotary drum c to which the head portion l is attached is fixed to the flange h.
(4) Finally, the motor unit m, the ring n for balance adjustment, the cover o, etc. are attached to the drum to complete the device.
[0021]
The shaft p passes through the hole of the motor unit m, and the shaft end is supported by the cover o.
[0022]
In the present embodiment, since the rotary side portion br of the rotary transformer is mounted on the rotary drum c via the flange h, when the flange h is mounted on the fixed drum d, the rotor coil of the rotary transformer and the magnetic head are electrically connected. Not connected to That is, if the gap of the rotary transformer is adjusted in this state, the mutual inductance of the rotary transformer can be accurately measured without being affected by the inductance of the head. Therefore, when an appropriate mutual inductance is obtained, the press-fitting of the shaft p into the hole q may be terminated.
[0023]
[Patent Document 1]
JP-A-2000-322702 (paragraph numbers 0012 to 0016, FIGS. 2 and 3)
[0024]
[Problems to be solved by the invention]
However, the conventional method has problems in accuracy of the mutual inductance of the rotary transformer and cost.
[0025]
For example, in the above embodiment (A), it is difficult to increase the accuracy of the mutual inductance by simply adjusting the gap to have a constant value in the case where there is a variation in the dimensions of component manufacturing or assembly. That is, the accuracy is lower than in the embodiment (B) in which the work is performed while directly measuring the mutual inductance of the rotary transformer. Alternatively, there is a problem in that the number of adjustment steps necessary for improving the accuracy of the mutual inductance is increased, and that a long working time is required.
[0026]
In the embodiment (B), the variation in the mutual inductance of the rotary transformer can be reduced, and a high-quality drum device can be manufactured. However, there is a problem in that the configuration is complicated and the cost is increased. For example, the number of flanges h is increased, and this part is provided with a direct bearing or a rotary side part br of a rotary transformer, and is a part that is connected to the rotary drum c, so that its shape is generally complicated. Since the accuracy of the flange h has a great influence on the rotational accuracy of the drum, high accuracy is required for its manufacture. As a result, the flange h becomes expensive, which causes an increase in apparatus cost.
[0027]
Therefore, the present invention provides a rotary head device and a recording / reproducing device using the same, in which variations in the mutual inductance of the rotary transformer are reduced, and therefore, the gap adjustment process and the device configuration are complicated, and the cost is increased. It is an object to avoid adverse effects.
[0028]
[Means for Solving the Problems]
In order to solve the above-described problems, the present invention provides a configuration in which a magnetic head and a reproducing circuit of the magnetic head are mounted on a rotating drum, and the reproducing circuit is connected to a rotor coil of a rotary transformer, or A magnetic head using a resistance effect element or a giant magnetoresistance effect element is mounted on a rotating drum, and the magnetic head is connected to a rotor coil of a rotary transformer.
[0029]
Therefore, according to the present invention, a reproduction circuit (amplifier, etc.) is provided between the magnetic head and the rotor coil of the rotary transformer to cut off the influence of the inductance component of the magnetic head, or to reduce the influence of the inductance component of the magnetic head. By connecting a resistance effect element or the like to the rotor coil of the rotary transformer, it is possible to adjust the gap of the rotary transformer while accurately measuring only the mutual inductance of the rotary transformer. In addition, since it is not necessary to disconnect the electrical connection between the magnetic head or the reproducing circuit and the rotor coil of the rotary transformer, the above-mentioned flange is not required.
[0030]
BEST MODE FOR CARRYING OUT THE INVENTION
FIG. 1 schematically shows a configuration example of a recording / reproducing apparatus using a rotary head device according to the present invention.
[0031]
The recording / reproducing apparatus 1 includes a rotary head device 3 for recording information on a tape-shaped recording medium (hereinafter simply referred to as “tape”) 2 or reproducing information recorded on the tape. Note that the “recording / reproducing device” includes, for example, a device dedicated to reproduction, a device for recording and reproducing, and the like.
[0032]
The tape 2 pulled out from the tape cassette 4 runs along a predetermined tape path while a part of the tape 2 is wound around a drum constituting the rotary head device 3.
[0033]
The rotary head device 3 is configured using a rotary drum 5 and a fixed drum 6, and magnetic recording and information reproduction on the tape 2 are performed using a magnetic head 3 a attached to the rotary drum 5.
[0034]
As schematically shown in an enlarged cross-sectional structure in the great circle of FIG. 1, the rotary head device 3 includes a fixed drum 6 having a rotary shaft 8 supported by a bearing portion 7 and a rotary drum 8 attached to the rotary shaft 8. (So-called flangeless structure), which is suitable for reducing the size (thinness), weight, and cost of the apparatus.
[0035]
A rotary transformer 10 is used to transmit a signal between a circuit unit inside the rotary head device 3 and a signal processing unit 9 provided outside thereof, and a fixed side portion (stator core and coil) 10s Is attached to the fixed drum 6, and a rotating side portion (rotor core and coil) 10 r is attached to the rotating drum 5. A slight gap “G” (shown exaggerated in the figure) is formed between the rotating side portion 10 r and the fixed side portion 10 s of the rotary transformer 10. Further, a head section including the magnetic head 3a and a circuit board 12 (provided with a power supply circuit and an amplifier circuit for a reproduction signal) supported by the support member 11 are arranged close to the rotating side portion 10r. .
[0036]
A tape running means 13 including a capstan, a pinch roller, a tape guide post, and the like is provided, and although not shown, various driving mechanisms constituting a reel rotation control means, a drum rotation control means, and the like. Needless to say, a mechanism and a servo control circuit are provided (or it may be considered as a tape running means including these mechanisms).
[0037]
FIG. 2 shows a configuration example of a rotary head device according to the present invention.
[0038]
The rotary head device 3 includes a fixed drum 6 having a rotating shaft and a bearing thereof, and a rotating drum 5 attached to the rotating shaft, and is of an upper drum rotating type (the rotating shaft direction is defined as a vertical direction). If so, the upper drum is a rotating drum.).
[0039]
Leads (not shown) for guiding the tape are processed with high precision on the fixed drum 6, and a shaft (rotating shaft) 8 and a bearing 14 thereof are provided at the center of the fixed drum 6. I have. That is, the bearings (direct bearings) 15, 15 integrated with the shaft 8 are assembled by shrink fitting and housed in the bearing portion 14, as shown partially cut away on the left side of the shaft 8.
[0040]
In the fixed drum 6, a concave portion 16 for forming a space for accommodating circuit components and the like is formed between the bearing portion 14 and the rotating drum 5.
[0041]
In order to transmit a signal to and from a head, a rotary transformer 10 of a flat facing type is used, and a fixed side portion (stator) 10 s of the rotary transformer is arranged in a concave portion 16. The stator is mounted on the bottom surface of the recess 16 by floating bonding in order to accurately set the height.
[0042]
The core (rotor core) that constitutes the rotation-side portion 10r of the rotary transformer 10 includes a plurality of support members 11, 11, 11 (one of which is shown in FIG. (Shown in cross section)) and fixed by adhesion. In this example, a cylindrical boss formed of a conductive material such as a metal is used as the support member 11. A rotor core is adhered to a flange 11a formed at one end of the boss, and the boss is attached to the rotating drum 5 by a fastening member 17 such as a screw.
[0043]
A circuit board 12 is fixed to the lower end of the support member 11 on the side opposite to the side where the rotor core is fixed (upper side in FIG. 2). For example, the support member 11 is in a state of being passed through an insertion hole formed in the circuit board 12, and the circuit board 12 is adhered to the support member 11.
[0044]
The circuit board 12 has a circuit for signal reproduction or signal recording and a power supply circuit, and electronic components 18, 18,... Constituting these circuits are mounted. For example, as described later, circuit components for driving a reproducing head and amplifying a reproducing signal, and components of a power supply circuit including a rectifying and smoothing circuit are mounted on a substrate. The power supply to the circuit unit is transmitted by a winding coil of the rotary transformer 10. For connection between each circuit unit and the coil (on the rotor side), a wire drawn from the coil is used. This is performed by soldering to a substrate. In addition, a ground portion electrically connected to the rotating drum is formed on the circuit board 12 for shielding noise, and the ground portion is electrically connected to the support member 11 using the connection member 19. Connected.
[0045]
The lower surface portion 20 of the rotary drum 5 forms a housing space for the rotary transformer 10, the circuit board 12, the support member 11 and the like together with the concave portion 16 of the fixed drum 6, and includes a reproducing head, a recording head, a head base and the like. .. (Only one is shown in FIG. 2) are attached to the lower surface 20 by screws. Further, head contacts 22, 22,... (Only one is shown in FIG. 2) are attached to the mounting surface (upper surface) of the circuit board 12 facing each head portion 21. The circuit board 12 and the magnetic head are electrically connected in a state where the contact of the head portion 21 is in contact with the magnetic head. Note that a simple and highly reliable connection can be made by using a spring-type head contact that can be automatically mounted.
[0046]
In addition, a balance weight 23 is attached to the lower surface 20 of the rotating drum 5.
[0047]
A rotation balance adjusting ring 24 is attached to the upper surface of the rotating drum 5, and steel balls 25 are inserted therein.
[0048]
A motor unit 26 for driving the rotary drum 5 is provided at the bottom of the fixed drum 6. The motor unit 26 includes a support plate 27 attached to the shaft 8, a magnet 28 and a back yoke 29 attached to the support plate 27, and a coil unit disposed between the magnet 28 and the back yoke 29. The coil unit 30 is attached to the fixed drum 6.
[0049]
In the rotary head device 3 shown in this example, since the member (flange) constituting the housing of the bearing portion 14 is not used, the shaft 8 of the fixed drum 6 is pressed into the shaft hole 5a formed in the rotary drum 5. The two drums are integrated. Since the flange is not used, the number of parts and man-hours can be reduced, which is advantageous in cost.
[0050]
FIGS. 3 and 4 are equivalent circuit diagrams respectively showing the following two aspects of the electrical connection between the rotary transformer 10 and the magnetic head 3a (reproducing head).
[0051]
(I) A form in which a reproducing circuit is arranged between a magnetic head and a rotor coil of a rotary transformer (see FIG. 3)
(II) An embodiment in which a magnetic head is directly connected to a rotor coil of a rotary transformer (see FIG. 4).
[0052]
First, in the embodiment (I), the magnetic head 31 and its reproducing circuit (reproducing amplifier, buffer, etc.) 32 are mounted on a rotating drum, and the output terminal of the reproducing circuit 32 is connected to the rotor coil rc of the rotary transformer 10. . For example, a detection signal from the magnetic head 31 is supplied to a reproduction amplifier and amplified, and the amplified output is transmitted to the fixed drum side via the rotor coil rc and the stator coil sc and sent to a reproduction signal processing unit (not shown). The information reproducing magnetic head 31 used in the present embodiment includes an inductive head and a head using a magnetoresistive effect (Magneto Resistive effect) element (hereinafter, referred to as “MR head”). When an MR head of a substrate shield type or the like is used, the circuit board 12 is provided with a power supply circuit for supplying a sense current to the head, an amplifier circuit for amplifying a reproduction signal from the MR head, and the like.
[0053]
In the embodiment (II), a magnetic head 33 using a magnetoresistive element is mounted on a rotating drum, and the magnetic head is connected to a rotor coil rc of the rotary transformer 10. Therefore, a detection signal from the magnetic head 33 is transmitted to the fixed drum via the rotor coil rc and the stator coil sc, and is sent to a reproduction signal processing unit (not shown). The magnetic head 33 used in the present embodiment has no or little inductance in electrical connection with the rotor coil, for example, a head using a GMR (giant magnetoresistance) element, An MR head is exemplified.
[0054]
In any case, the winding of the rotor coil rc is soldered to a predetermined contact on the circuit board 12 and is electrically connected to the head unit 21 via the head contact 22.
[0055]
FIG. 5 is a plan view showing an example of the circuit board 12 on which electronic components are mounted, and FIG. 6 is a view of the rotary drum 5 with the rotary transformer and the circuit board removed from the lower surface 20 side. In this example, two MR heads for reproduction and two recording heads are mounted.
[0056]
The circuit board 12 has a ring shape when viewed from a central axis orthogonal to the paper surface of FIG. 5, and the shaft 8 and the bearing portion 14 are inserted into the central circular hole 12a.
[0057]
Four head contacts 22a, 22a and 22b, 22b are arranged on the substrate. Two of them 22a, 22a are provided for connection to the reproducing heads 21a, 21a, and are symmetrically positioned with respect to the center axis of the center circular hole 12a in the left-right direction of FIG. The head contacts 22b, 22b are provided for connection with the recording heads 21b, 21b. The head contacts 22b, 22b are arranged around the central axis of the central circular hole 12a at a predetermined angular interval from the head contacts 22a, 22a. Are located in As shown in FIG. 6, the two recording heads have a close positional relationship. This is to reduce the difference in head height due to rotational blur by bringing the two close to each other.
[0058]
In this example, three bosses 11A, 11B, and 11C are used as the support member 11, and the bosses 11A and 11B are located between the head contacts 22a and 22b, respectively. The boss 11C is located on the opposite side (downward in the figure) to the head contacts 22b, 22b with the center axis of the center circular hole 12a interposed therebetween, and the connection member 19 is elastically contacted with the side surface of the boss 11C. Attached to the board.
[0059]
The boss 11C is located near the outer peripheral edge of the drum, and the ground part 34 and the mounting components 18, 18,... Constituting the rectifying circuit block are arranged in the vicinity of the boss 11C. In other words, the connection region with the ground portion 34 is located at the lower left of the boss 11C, and each component of the rectifier circuit block is mounted on the left side of the boss 11C. 34 is preferably located as close as possible.
[0060]
.. Are mounted above the rectifier circuit block and to the right of the boss 11C.
[0061]
Next, a procedure for assembling the rotary head device 3 will be described with reference to FIG. FIG. 7 shows a state before the respective parts of the rotary drum 5 and the fixed drum 6 constituting the rotary head device 3 shown in FIG. 2 are connected, and the press-fitting means 35 of the rotary drum 5 and the rotary transformer 10 The measurement means 36 (connected to the stator coil) relating to the mutual inductance is simply shown.
[0062]
The assembling method may be performed according to the following procedure.
[0063]
(1) Assemble each part of fixed drum and rotating drum
(2) The shaft 8 is pressed into the shaft hole 5a of the rotary drum 5. At this time, the mutual inductance between the rotating-side portion 10r and the fixed-side portion 10s of the rotary transformer 10 is measured by the measuring means 36, and the measurement result is adjusted to an appropriate value.
(3) Press-fitting is terminated when the mutual inductance measurement result falls within the target value or the allowable range.
[0064]
In the above (1), the lower drum (fixed drum 6) is completed by mounting and assembling the direct bearing constituting the bearing portion 14, the motor portion 26, the fixed side portion 10s of the rotary transformer 10, and the like. On the other hand, as for the rotary drum 5, the upper drum portion is completed by mounting and assembling the rotary side portion 10r of the rotary transformer 10, the circuit board 12, the head portion 21, and the like.
[0065]
After the press-fitting step (2), the gap of the rotary transformer 10 is determined in (3), and this gap value differs for each drum device. That is, instead of adjusting the gap value to be constant, it is possible to accurately measure the gap while directly measuring the mutual inductance so that the actual measured value becomes the target value, thereby completing the drum device.
[0066]
Also in this example, as in the conventional case, it is necessary to adjust the gap so that the mutual inductance of the rotary transformer becomes an appropriate value in the press-fitting operation. In a device equipped with only an inductive head, when the head and the rotor coil of the rotary transformer are electrically connected, it is difficult to determine the gap of the rotary transformer while measuring the mutual inductance of the rotary transformer. (Because the inductance of the inductive head cannot be ignored as described above.)
[0067]
However, in the present invention, the mutual inductance of the rotary transformer can be accurately measured even when the magnetic head and the rotor coil are electrically connected by adopting the above configuration (I) or (II). The gap can be adjusted while performing the adjustment. For example, in an apparatus configuration in which a reproducing MR head is mounted in addition to a recording inductive head, the gap between the rotating side portion and the fixed side portion of the rotary transformer is determined while observing the mutual inductance of the rotary transformer to which the MR head is connected. Can be determined. That is, the shaft 8 of the fixed drum 6 is pressed into the shaft hole 5a of the rotating drum 5 while measuring the mutual inductance of the channel to which the MR head is connected. Since the MR head has almost no inductance, the measured mutual inductance (measured value) is equivalent to the mutual inductance of the rotary transformer. Thus, in the assembling process, an optimum mutual inductance of the rotary transformer can be obtained, and the gap can be easily adjusted. For example, in comparison with the method disclosed in Patent Document 1, the step of measuring the secondary side inductance of the rotary transformer, the step of determining the target total inductance, and the step of fine-tuning the final target total inductance are: Not required. In particular, in the measurement of the secondary inductance, since it is difficult to stabilize the measured value, there is a great benefit due to the elimination of this measurement step. Further, the target total inductance is simple because a constant value may be set from the beginning, and it is simple. Fine adjustment is not required, so that complicated measuring equipment is not required.
[0068]
Furthermore, since it is not necessary to use a flange which has been a complicated and very expensive cutting part, the apparatus can be manufactured at low cost.
[0069]
FIG. 8 shows a circuit configuration example 37 of a main part in the recording / reproducing apparatus 1.
[0070]
The fixed-side circuit of the rotary transformer 10 includes a power transmission unit 38, a reproduction signal processing unit 39, and a recording signal processing unit 40. Each circuit unit is connected to a stator coil (sc1 to 5) of the rotary transformer 10, respectively. Have been.
[0071]
The power transmission unit 38 includes a drive circuit for transmitting a sine wave or a rectangular wave AC output to a power supply unit in the rotating drum, and is connected to the stator coil sc1 of the rotary transformer 10. That is, the AC output of the power transmission unit 38 is transmitted from the stator coil sc1 to the secondary coil rc1 and supplied to the rectifier circuit block 41.
[0072]
The circuit section 12b indicates a circuit formed on the circuit board 12.
[0073]
The rectifier circuit block 41 that constitutes a power supply unit (power supply circuit) converts AC power input from the rotor coil rc1 to DC power, and has a rectifying and smoothing action (in the figure, the symbols of diodes and capacitors are used). It is shown simply.) Then, the DC output of the rectifier circuit block 41 is supplied to a stabilized power supply circuit 42 (indicated by “REG” in the figure).
[0074]
A voltage regulator circuit is used as the stabilizing power supply circuit 42. The voltage regulator circuit suppresses fluctuations of the DC power supply voltage from the rectifier circuit block 41 to generate a constant power supply voltage, and the reproduction amplifiers 43 and 44 (FIG. ”). The stabilized power supply circuit 42 constitutes a reproduction amplifier block 45 together with the reproduction amplifiers 43 and 44, and these circuits and the rectifier circuit block 41 are arranged on the circuit board 12.
[0075]
The reproduction amplifiers 43 and 44 are provided separately for the reproduction heads 46 and 47, respectively. As the reproducing head, an inductive head, an MR head, a GMR head, or the like can be used. In this example, an MR head is used. These reproduction amplifiers have a role of generating a bias magnetic field by supplying a sense current necessary for driving the MR head to the head, and amplifying a signal read from the magnetic tape by the MR head. The amplified signal is sent to a buffer-up in the reproduction signal processing unit 39 via the rotary transformer 10. The output terminal of the reproduction amplifier 43 is connected to the rotor coil rc2 of the rotary transformer 10, and the output terminal of the reproduction amplifier 44 is connected to the rotor coil rc3 of the rotary transformer 10.
[0076]
When the reproduction head side is viewed from the rotor coils rc2 and rc3, the reproduction channel when power is not supplied is almost open (the output terminals of the reproduction amplifiers 43 and 44 are close to the open state), and each reproduction amplifier is closed. The presence of a head (MR head in this example) connected to the input side hardly affects the measurement of the mutual inductance of the rotary transformer 10.
[0077]
Regarding the recording signal processing, the output signal of the buffer amplifier constituting the recording signal processing unit 40 is transmitted to the rotary drum via the rotary transformer 10 and supplied to the recording heads 48 and 49. That is, the output terminals of the recording signal processing unit 40 are connected to the stator coils sc4 and sc5 of the rotary transformer 10, respectively, and the rotor coils rc4 and rc5 of the rotary transformer 10 are connected to the magnetic heads 48 and 49, respectively. An inductive head is used for each recording head, and a recording signal is written on a magnetic tape.
[0078]
In a rotary head device for magnetic recording, it is very important to properly obtain a gap between a rotary side portion and a fixed side portion of a rotary transformer in order to obtain a good electric signal. According to the configuration described above, for example, the following various advantages can be obtained.
[0079]
・ When determining the gap of the rotary transformer, even if the head and rotor coil are electrically connected, adjust the gap while measuring the mutual inductance of the rotary transformer directly to obtain an appropriate mutual inductance. (For example, the mutual inductance may be measured on a channel to which an MR head or a reproduction amplifier is connected).
[0080]
-By realizing the optimization of the gap in the rotary transformer, good signal reproduction or recording becomes possible. As a result, a high-quality signal can be obtained and transmitted to an external device.
[0081]
It is not necessary to separate the head and rotary transformer in order to measure mutual inductance during assembly. That is, there is no need for a flange that connects the rotary shaft, the rotary drum, and the rotary side portion of the rotary transformer. As a result, the number of parts and the number of assembly steps can be reduced, and the thickness and cost of the rotary head device can be reduced.
[0082]
【The invention's effect】
As is apparent from the above description, according to the first and third aspects of the present invention, when measuring the mutual inductance of the rotary transformer, the influence of the magnetic head on the mutual inductance is prevented. be able to. As a result, it is possible to adjust the gap of the rotary transformer with high accuracy while reducing the variation in the measurement, and to improve the performance of the rotary head device. In addition, there is no adverse effect such as a complicated gap adjusting process, a complicated device configuration, and an increase in cost.
[0083]
According to the second and fourth aspects of the present invention, the magnetic head and the rotor coil of the rotary transformer are electrically connected by using a magnetoresistive element or a giant magnetoresistive element having a very small inductance. However, the influence on the mutual inductance measurement of the rotary transformer can be eliminated, and the configuration is simple.
[0084]
According to the third and fourth aspects of the present invention, it is effective for high performance and high reliability when applied to a recording / reproducing apparatus.
[Brief description of the drawings]
FIG. 1 is a schematic diagram showing a configuration example of a recording / reproducing apparatus according to the present invention.
FIG. 2 is a diagram showing a configuration example of a rotary head device according to the present invention.
FIG. 3 is an equivalent circuit diagram showing an example of an electrical connection between a rotary transformer and a magnetic head together with FIG. 4, and FIG. 3 shows an example of a configuration in which a reproducing circuit is mounted on a rotating drum.
FIG. 4 is a diagram illustrating a configuration example when a magnetoresistive element is used.
FIG. 5 is a plan view showing an example of a component arrangement on a circuit board.
FIG. 6 is a diagram illustrating an example of the arrangement of a head unit in a rotating drum.
FIG. 7 is a diagram for explaining assembly of the rotary head device.
FIG. 8 is a circuit block diagram illustrating an electrical connection relationship of a main part of the circuit.
FIG. 9 is an explanatory diagram of a conventional example.
FIG. 10 is an explanatory view of a conventional example having a flange structure.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Recording / reproducing apparatus, 2 ... Tape recording medium, 3 ... Rotary head apparatus, 3a ... Magnetic head, 5 ... Rotating drum, 6 ... Fixed drum, 8 ... Rotating shaft, 10 ... Rotary transformer, 13 ... Tape running means Reference numeral 31, a magnetic head, 32, a reproducing circuit, 33, a magnetic head, rc, a rotor coil

Claims (4)

A rotary drum attached to the rotary shaft, and a fixed drum having a bearing portion for the rotary shaft, and a magnetic head provided on the rotary drum performs signal recording or reproduction on the tape-shaped recording medium, and transmits and receives signals via a rotary transformer. A rotary head device configured to perform signal transmission by
A rotary head device, wherein the magnetic head and a reproducing circuit of the magnetic head are mounted on the rotating drum, and the reproducing circuit is connected to a rotor coil of the rotary transformer. A rotary drum attached to the rotary shaft, and a fixed drum having a bearing portion for the rotary shaft, and a magnetic head provided on the rotary drum performs signal recording or reproduction on the tape-shaped recording medium, and transmits and receives signals via a rotary transformer. A rotary head device configured to perform signal transmission by
A rotary head device, wherein the magnetic head using a magnetoresistive element or a giant magnetoresistive element is mounted on the rotary drum, and the magnetic head is connected to a rotor coil of the rotary transformer. A fixed drum having a bearing portion for the rotating shaft, a rotating drum attached to the rotating shaft, and tape running means for the tape-shaped recording medium are provided. In a recording and reproducing apparatus configured to perform signal transmission via a rotary transformer when performing such signal recording or reproduction,
A recording / reproducing apparatus, wherein the magnetic head and a reproducing circuit of the magnetic head are mounted on the rotating drum, and the reproducing circuit is connected to a rotor coil of the rotary transformer. A fixed drum having a bearing portion for the rotating shaft, a rotating drum attached to the rotating shaft, and tape running means for the tape-shaped recording medium are provided. In a recording and reproducing apparatus configured to perform signal transmission via a rotary transformer when performing such signal recording or reproduction,
A recording / reproducing apparatus, wherein the magnetic head using a magnetoresistive element or a giant magnetoresistive element is mounted on the rotating drum, and the magnetic head is connected to a rotor coil of the rotary transformer.

Images