JP3018922B2 - Movable head device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a movable head device of a rotary magnetic recording / reproducing apparatus for recording / reproducing a signal obliquely on a magnetic tape.

[0002]

2. Description of the Related Art In recent years, a movable head device of a rotary magnetic recording / reproducing apparatus reproduces a track on which a large number of signals such as a wideband digital signal and a high-definition television signal are recorded at high density with high precision. There must be. A specific problem required of the apparatus for realizing this is to distribute a large amount of signals to a plurality of heads, record at a narrow track pitch, and reproduce the track with high accuracy in all modes. . In particular, the movable head device includes: 1. large amplitude; 2. high resonance; 3. High accuracy of multiple heads; It is required to reduce the total cost (responding to 1-3 leads to an increase in cost).

A conventional movable head device is disclosed in, for example, Japanese Patent Application Laid-Open No. 5-120658, Japanese Utility Model Laid-Open No. 63-153316, and Japanese Utility Model Laid-Open No. 60-47119.

[0004] A conventional movable head device will be described below. FIG. 11 is a plan view of a rotary magnetic recording / reproducing apparatus incorporating the conventional movable head device. In the figure, a magnetic tape 1 runs around a fixed drum (not shown) having a spiral guide and a rotating drum 2. A base 4 having recording head chips 3 a, 3 b, 3 c, and 3 d adhered and fixed to the tip of the rotary drum 2 is attached with mounting screws 5. Further, one unit having the same configuration is further provided at the 180 ° facing position. Where 1
The reason why four head chips are incorporated in the base is to divide a large amount of signals and record them simultaneously. Further, a bimorph 6 in which two piezoelectric plates are bonded is provided on the rotating drum 2.
a is fixed by screws together with bonding in a state sandwiched between the fixing members 7a and 8a, and the bimorph plate 6a
The head base 9a as shown in FIG.
(Ceramic) is adhered and fixed, and the head base 9a has reproducing head chips 10a, 10b, 10c,
10d is adhesively fixed, and the recording head chip 3a,
The signals recorded in 3b, 3c and 3d are reproduced. Further, as shown in FIG. 14, the head chips 10a, 10b, 10c, 1
0d is provided with windings 11a, 11b, 11c and 11d, and the respective lead wires are gathered on the side surface of the bimorph 6a and fixed with an adhesive along the center of the plate thickness of the bimorph 6a. . This is because even if the bimorph 6a is curved, it does not expand and contract at the center of the plate thickness, and there is no problem such as disconnection (described in Japanese Utility Model Application Laid-Open No. 63-153316). Also, the lead wires from the head chips 10a, 10b, 10c, and 10d to the end faces of the bimorph 6a are molded and fixed with the adhesive 12 (the lead wire mold is described in Japanese Utility Model Application Publication No. No. 47119). The type of this adhesive uses the most common two-liquid mixed type epoxy adhesive with emphasis on handling and cost reduction, and is about 60 ° C. (this degree in relation to the Curie temperature of the piezoelectric material). (Set) at a high temperature for a short time to cure. The four heads are provided with a relative height so that tracks of a predetermined pitch are simultaneously recorded and reproduced on the tape 1 for both recording and reproduction, and are attached to the head base 9a with high precision. Further, one unit having the same configuration is further provided at the 180 ° facing position.

The operation of the conventional movable head device configured as described above will be described below.

First, when the rotary drum 2 is rotated in the direction of arrow A in FIG. 11 and the magnetic tape 1 is run in the direction of arrow to supply recording signals to the recording head chips 3a, 3b, 3c and 3d, the magnetic tape 1 Track 13 in FIG.
a, 13b, 13c, and 13d are simultaneously recorded. Next, when a recording signal is supplied to the recording head chips 63a, 63b, 63c, 63d, tracks (not shown) are continuously recorded on the magnetic tape 1. Thereafter, this operation is repeatedly and continuously recorded. Next, the reproducing operation will be described. First, since the speed of the magnetic tape 1 during normal reproduction is the same as during recording, the reproducing head chips 10a, 10b, 1
0c and 10d are tracks 13a, 13b and 13 in FIG.
Trace c and 13d accurately and reproduce the signal. Next, in the special reproduction, for example, in the case of still reproduction, since the magnetic tape 1 is stopped, the reproducing head chips 10a, 1
The trajectories 0b, 10c, and 10d are indicated by the dashed line 14 in FIG.
(14 corresponds to the reproduction head chip 10d), and a reproduction signal of the entire track cannot be obtained. Therefore, in order to trace accurately even in this still playback mode,
By gradually applying a voltage to the bimorph 6a to bend the bimorph 6a, the reproducing head chips 10a, 10b, 10c, 1
0d is displaced in the height direction and moves in the direction of arrow B in FIG. 12. If this operation is variably performed from the starting point C to the ending point D of the track 13d, the track 13d can be accurately traced and a signal can be reproduced.

[0007]

However, in the above-mentioned conventional structure, the lead wire mold 12 is made of an adhesive having a large expansion coefficient (60.times.10.sup.- ⁶ / .degree. C.), and the head base 9a is formed.
Is made of a ceramic (7 × 10 ⁻⁶ / ° C.) having a small expansion coefficient, there is a problem that the relative height accuracy of the head is deteriorated with respect to a temperature change. The contents will be described in more detail. FIG. 14 is an enlarged perspective view of the head portion, and shows the applied state of the mold 12 portion. As shown in FIG. 15, after the lead wire treatment, the mold 12 is applied and is cured by heating at about 60 ° C. for a short time (about 30 minutes) in order to cure it in a short time. Thereafter, when the temperature is returned to room temperature (20 ° C.), all the members thermally shrink, and the mold 12 made of the adhesive having a large expansion coefficient shrinks about 10 times compared to the head base 9a made of ceramic. The epoxy adhesive used here has a relatively high hardness (8 in the Shore-D range).
0), a large acting force is generated at the time of contraction, and the head base 9a is deformed in the direction of arrow E. At the same time, the head chip 10d is pulled in the direction of arrow F, and as a result, the tip of the head chip 10d is displaced in the direction of arrow G to cause a change in height. The amount varies depending on the application amount and application position of the mold, and there is a large variation in each head position in reality. Therefore, a relative head height difference of several μm occurs between the respective heads after cooling. Cage. If the environment of use further decreases, the difference increases. Then, there is a problem that the head reproduction output decreases due to the relative height difference. Here, there is a type that cures in a short time at room temperature with a two-component mixed type adhesive, but this is not practical because it starts to cure during the work. As a solution to this problem, there is a method of increasing the strength by increasing the thickness of the head base 9a. However, the weight of the tip of the bimorph plate 6a increases, the resonance frequency of the unit decreases, and the response characteristic of the head decreases. And the reproduction output deteriorates.

SUMMARY OF THE INVENTION The present invention solves the above-mentioned conventional problems, and secures a high resonance frequency of a movable head unit equipped with multiple heads, and also has a movable head having a high relative head height with respect to a temperature change. The purpose is to provide the device.

[0009]

In order to achieve this object, a movable head device according to the present invention is made of a material that transmits ultraviolet light, and has a Young's modulus of 5 having a head chip having a winding on one of its upper surfaces. × 10 ³ kg / mm ² or more, density 2.
5 or less, a plurality of sub-head bases having a plate thickness of a minimum 0.19 mm to which an amount necessary for height correction of adjacent heads is added, and a head chip attaching surface on the lower surface of the sub-head bases in plan view. A main head base whose non-overlapping surface is fixed with an ultraviolet curing adhesive, and a shore D range 37 or less for fixing a lead wire drawn from a winding along the sub head base and the main head base. And a electromechanical transducer for displacing the main head base in the head height direction.

[0010]

According to the present invention, a Young's modulus of 5.times.1
0 ³ kg / mm ² or more, density 2.5 or less, minimum thickness 0.1
A thin sub-head base configured to have a dimension of 9 mm plus the amount necessary for height correction of adjacent heads acts to increase the resonance frequency of the movable head unit, and furthermore, has a size of 37 or less in the Shore-D range. The mold agent having hardness acts to reduce deformation of the sub-head base when the temperature changes, and to reduce a difference in relative height of the head due to a difference in application of the mold agent.

[0011]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a plan view and a side view of a movable head device according to an embodiment of the present invention. In the figure, one of the bimorphs 17, 18 in which two piezoelectric plates 15a, 15b and 16a, 16b are bonded together is fixed to the fixing members 19, 20, 21 by being sandwiched between the screws 22 with adhesion, On the free ends of the bimorphs 17 and 18, connecting members 25 having thin bent portions 23 and 24 are fixed by adhesion at the extended positions of the bimorphs 17 and 18, respectively.
The material of the connecting member 25 is lightweight and the bent portions 23, 24
Use a carbon fiber composite material with less fatigue against repeated bending. Specifically, a block of a composite material in which a bundle of carbon fibers having a long dimension in the longitudinal direction having a diameter of about 7 μm is cured with an epoxy resin is manufactured and processed into the shape shown in the drawing. Further, a mounting portion 28 for fixing a main head base 26 (made of an aluminum alloy because it is lightweight and easy to tap) using a single screw 27 is provided at the end of the connecting member 25. The sub head bases 33, 34, 35, and 36 to which the reproduction head chips 29, 30, 31, and 32 are adhesively fixed are fixed to one side of the main head base 26. On the lower surface on both sides of the main head base 26, one ends of flexible relay boards 41 and 42 for relaying the head windings 37, 38, 39 and 40 are adhered and fixed, and the wire is soldered. Connected. The other ends of the relay boards 41 and 42 are fixed to the fixing member 21 with screws 43 and 44. Further, the head windings 37, 38, 39, 4
The lead portion 45 from 0 to the relay position is fixed with a molding adhesive 46 as shown in FIG.

The procedure for assembling the movable head device having the above configuration is as follows. First, the bimorphs 17 and 18 are fixed to the fixing members 19, 20, and 21.
5 are bonded and assembled as an actuator unit. The head is assembled as a head base unit 51 as shown in FIG.

First, the assembly of the head base unit 51 will be described in detail. First, head chip 29,
30, 31, 32 and sub head bases 33, 34, 3
The heights of the heads at that time are as shown in FIG. 2, and the height required for tracing a predetermined track on the tape based on the gap lower end H of the head chip 29 as shown in FIG. It is necessary to set positions I, J and K. As a method, a head chip having two kinds of gap azimuths and a sub head base having two kinds of plate thicknesses are used, and a relative height difference is secured by a combination thereof. That is, the head chips 29 and 31 and 30 and 32 are the same head chip, and the sub head bases 33 and 34 and 35 and 36 are of the same thickness, and are combined with each other to have a predetermined height difference. Are set for the gap heights L and M of the head chip and the thickness difference N of the sub head base.

However, the combination described above alone cannot achieve a high relative head height, and the relative height accuracy ± 1 required for a broadcasting digital VTR having a track pitch of about 20 μm.
In order to satisfy μm or less, the following high-precision means is required. First, as shown in FIG. 3, after the head chip 29 and the sub head base 33 are bonded,
Is wrapped to finish it in a predetermined R shape. Next, the upper surface of the sub head base 33 is sucked by the suction nozzle 47 connected to the vacuum suction device, and is moved to the upper surface of the main head base 26 attached to the surface plate 48 as shown in FIG. At this time, the relay boards 41 and 42 are bonded to both sides of the lower surface of the main head base 26 in advance. Then, the suction nozzle 47 is slowly lowered, and stopped at a position where the lower surface of the sub head base 33 is in contact with the upper surface of the main head base 26, and the tip height of the head chip 29 is measured by the optical microscope 48. . Next, the suction nozzle 47 is raised, and a predetermined amount (adhesive is dispersed over the entire surface of the bonding surface, at a position where the sub head base 33 of the main head base 26 is bonded).
UV-curable adhesive 49 (see FIG. 5). Then, the suction nozzle 47 is slowly lowered again, and the position (sub head base) is lowered.
(The position where the lower surface of the head 33 is in contact with the upper surface of the main head base 26) and stopped at a position raised by about 10 μm, and while observing the tip of the head chip 29 with an optical microscope, the gap azimuth and the gap position with respect to the vertex of the front surface R Adjust the amount of protrusion. When the adjustment and confirmation of all items are completed, the adhesive is cured in a short time by irradiating ultraviolet rays 50 from the hollow portion of the suction nozzle 47, and the suction is stopped.
Remove. Next, an ultraviolet curing adhesive 49 is applied to the position of the sub head base 34, and the sub head base 34 on which the bonding of the head chip 30 and the front lapping have been completed is completed.
Is sucked by the suction nozzle 47 and slowly lowered to a predetermined position. Then, the head chip 29 is stopped at a position raised by a predetermined amount from the final set height, and the gap azimuth, the gap position with respect to the front surface R vertex, the protrusion amount, and the like are adjusted as described above. When the adjustment and confirmation of all the items are completed, the adhesive is hardened in a short time by irradiating ultraviolet rays 50 from the hollow portion of the suction nozzle 47, and the suction is stopped.
Remove. At this time, the head position is lowered by a small amount due to the curing shrinkage of the adhesive, but there is no problem if the curing shrinkage amount is experimentally obtained in advance and corrected. Remaining head chip 3
The head base unit 51 shown in FIG.

Next, the configuration of the sub-head bases 33, 34, 35, 36 for realizing high resonance of the unit will be described. First, regarding the necessity of a sub head base, it is difficult to secure a relative height accuracy of 1 μm with a single head chip, and it is necessary to correct as described above when assembling. Among the correction means, the method of controlling with an adhesive layer at the time of bonding is the most effective, and among the adhesives, the ultraviolet curing type is the most excellent in workability, work time and apparatus scale. However, the head chip is made of a material or structure that does not transmit ultraviolet rays, and cannot be directly bonded to the head base. Therefore, it must be bonded through a component that transmits ultraviolet light, such as glass. Although the above-mentioned sub-head base is provided for that purpose, the weight of the head part is increased and the resonance frequency of the unit is lowered. Therefore, the parts must be lightest. In order to achieve the object, the present embodiment is configured as follows. First, as a material, glass is a material having a high transmittance of ultraviolet rays, a high rigidity and a light weight, and is most suitable for a lightweight condition, having a Young's modulus of 5 × 10 ³ kg / mm ² , a density of 2.5, a hardness of 500 kg / mm ² , Glass having an expansion coefficient of 120 × 10 ⁻⁷ / ° C. is used. Next, regarding dimensions, first, the area will be described. In this embodiment, the sub-head bases 33, 34, 35 and 36 made of glass are suction-held by a suction nozzle 47, and the above-mentioned various adjustments are made in a state where an uncured adhesive layer is interposed between the main head base 26 and the main head base 26. Must be implemented. Therefore, a suction force enough to withstand the resistance force due to the viscosity of the adhesive is required, and the force is determined by the capacity of the vacuum device and the suction area. Explaining from the suction device, recently, it is common to use a vacuum device that generates vacuum suction using compressed air, which is superior in performance, function, and cost, all compared to vacuum pumps, and commercially available devices Maximum vacuum of 70
It is about cmHg. The minimum outer dimensions of the suction nozzle required to obtain the above-described suction force using a vacuum device of this degree are 2 mm × 1.2 mm (the wall thickness is at least 0.1 mm) shown in FIG.
2 mm). Here, the balance of both dimensions is determined by the overall balance of the sub head base and the head chip.
The size is set to 2 mm x 1.5 mm for ease of manufacture, and the length of the sub head base is set to 1 mm to secure the bonding strength.
And the outer diameter is set to 2 mm × 2.7 mm. The distance between the suction nozzle 47 and the head chip 29 is determined by setting the adhesive of the head chip 29 to the sub head base 33.
0.5m so that it is safe to flow out as shown in Fig. 5
m. Next, regarding the thickness of the sub-head base, when the sub-head base having the above dimensions is subjected to double-sided lapping or various types of handling, the thickness at which a high yield can be secured without being damaged is from the results of the trial production to a minimum of 0%. .19m
m. Therefore, the sub head bases 33 and 34 shown in FIG.
Is set to 0.19 mm and the sub head base 3
5 and 36 are 0.19 mm to which the correction value N of the head height is added.
+ Nmm. As described above, the head section of this embodiment reduces the weight of the sub head base to the utmost and increases the resonance frequency of the unit. In addition, the adhesive must be surely cured by ultraviolet rays irradiated from the inside of the suction nozzle 47, and the position of the adhesive layer must be limited to the outer periphery of the nozzle (about the nozzle plate thickness is cured by diffused ultraviolet rays). No. Therefore, the distance from the tip of the head chip 29 of the present embodiment to the front of the main head base 26 is 2 as shown in FIG.
mm.

The windings 37, 38, 39, 40 are applied to the head chips 29, 30, 31, 32 of the head base unit 51 assembled as described above, and further, lead wires are provided as shown in FIG. It is soldered to the relay board 41 along the sub head base 33 and the main head base 26.
Here, it is required that the lead wire lead-out length be shortest in order to improve head characteristics and reduce noise.
Is the best route. Thereafter, as shown in FIG. 8, the lead portion is fixed and protected by a molding agent (adhesive) 46. Next, the mold agent used here will be described in detail.

For example, when the molding shown in FIG. 8 is performed by using the adhesive described in the conventional example and the temperature is changed, the sub-head base 33 is affected by the molding agent having a large thermal expansion and contraction, and the subhead base 33 is moved by the arrow L or The head is deformed in the M direction, and the height of the head tip changes. Here, the first method for reducing the change in head height is to increase the strength of the sub head base 33,
The second method is to use a molding agent having a small expansion coefficient. A third method is to use a low-hardness molding agent. Among them, the first method is already limited in material and dimensions as described above. For the second method, it is basically impossible to obtain an adhesive having an expansion coefficient close to that of glass within a general adhesive having an extremely large expansion coefficient. With the third method, a low-hardness adhesive can be easily obtained, and there is no particular problem in reducing the hardness for the purpose of molding. Therefore, the third method is practical. FIG. 9 is data obtained by experimentally obtaining a change in head height when a temperature change of 60 ° C. was given using two types of molding agents having different hardnesses (Shore-D range) after curing. Yes,
The horizontal axis indicates the hardness of the mold agent after curing, and the vertical axis indicates the amount of change in the head height. The reason why the temperature change range is set to 60 ° C. is as follows.
The operating environment is 0 ° C to 40 ° C, and the total temperature change range is 0 ° C to 60 ° C by estimating the temperature rise inside the device to 20 ° C.
According to the prediction. From the data shown in FIG. 9, it was found that the mold agent hardness capable of ensuring a head height change of 1 μm or less was 37 or less. Here, if the absolute amount of the height change at a temperature change of 60 ° C. is set to 1 μm or less, the relative height change caused by uneven application of the molding agent at the four head positions can surely be 1 μm or less. Therefore, in this embodiment, a two-part mixed type mold agent having a hardness of 37 or less in the Shore-D range after curing is used,
Cured for a short time at a high temperature of ℃. The head base unit 51 completed in this way is incorporated into the connecting member 25 of the actuator unit already assembled. The method will be described with reference to FIG.

First, an adhesive of a solvent dispersing type using a weak solvent such as alcohol is applied to the surface 52 of the connecting member 25 which is in contact with the back surface of the main head base 26, and the main head base 26 is adhered. Fix with screws 53. Here, the necessity of bonding will be described. When the screw 53 is tightened, the main head base 26 is deformed into a V-shape around the screw position, and a relative height difference occurs in the head height. To prevent this deformation, the rigidity of the main head base 26 (aluminum alloy) must be increased or the tightening torque of the screws must be reduced. For the former, there is an increase in thickness and the use of highly elastic materials.However, an increase in thickness increases the weight and lowers the resonance frequency. There is a problem that processing is difficult, and there is no material other than aluminum alloys including cost. Therefore, this embodiment corresponds to the latter, and prevents deformation with a low tightening torque of 50 g-cm. However, with this fastening force, there is no problem even if an initial centrifugal force of about 1500 G acting on normal rotation is given,
Incomplete, including long-term reliability. Therefore, it is firmly fixed together with bonding to secure stability. Further, only the connecting member 25 and the rear surface of the main head base 26 are bonded and fixed, and the lower surface of the main head base 26 and the mounting portion 2 are fixed.
8 is not bonded because the difference in expansion and contraction caused by the difference in the expansion coefficient of the member between the mounting portion 28 and the main head base 26 when a temperature difference occurs due to a change in the use environment of the device. This is designed so that the head base 26 is not deformed and the relative height of the head does not change. Here, the same deformation occurs between the back surface of the main head base 26 and the connecting member 25, but there is no problem because the deformation is in a direction different from the head height direction by 90 degrees. Another purpose of the structure in which the lower surface of the main head base 26 and the mounting portion 28 are not bonded is that when the head base is replaced with a new head base, foreign matter such as a residual hardening adhesive is laid in the main head base 26 so that the main head base 26 is not bonded. It is also possible to prevent the head height from changing due to inclination or deformation of the head.

After the head base unit 51 is assembled as described above, the other of the relay boards 41 and 42 is screwed to the fixing member 21 with screws 43 and 44 as shown in FIG. 1 to complete the movable head unit.

The operation of the movable head device according to the embodiment of the present invention configured as described above will be described below.

For normal reproduction of a signal continuously recorded on a magnetic tape (not shown), the bimorph 17, 1
A rotating drum (not shown) is rotated without applying a voltage to 8, and the reproducing heads 29, 30, 31, and 32 reproduce signals. Next, at the time of special reproduction, for example, in the case of still reproduction, the magnetic tape (not shown) is stopped, so that the reproduction heads 29, 30, 31, 32 do not reproduce the signal of the entire track as in the conventional example. Therefore, in order to accurately trace even in the still playback mode, the bimorph 17,
18 to apply a voltage to the bimorph 17, as shown in FIG.
The bending of the reproducing heads 29, 30, 3
1, 32 are displaced in the track width direction to accurately trace a track (not shown) and reproduce a signal. Further, since the resonance frequency of the head base unit 51 is increased by reducing the weight of the head base unit 51, the head quickly returns during the period from the end of the first head scan to the start of the second scan, and a stable state without vibration. Can start the second scan. In addition, the bent portion 23 provided on the connecting member 25,
24 operates so that the reproducing heads 29, 30, 31, and 32 are displaced in parallel, and good head touch is obtained. In addition, even if the operating environment of the apparatus changes and a temperature difference occurs, the deformation of the sub head base is drastically reduced by the low hardness molding agent, so that the maximum output of all heads can be obtained. When replacing the head base unit 51 with a new head due to breakage or life of the reproducing heads 29, 30, 31, 32, it is necessary to remove the screw 53 and allow alcohol to permeate the bonding portion. Can be easily dissolved and removed. At this time, even if the alcohol adheres to the connecting member 25, the resin does not deteriorate for a short time.

As described above, according to the present embodiment, a plurality of sub-head bases have a Young's modulus of 5 × 10 ³ Kg / mm ² or more, a density of 2.5 or less, and a plate thickness of at least 0.19 mm. The unit is made of glass with dimensions that add the amount required for height correction, ensuring a high resonance frequency of the unit,
Further, the distance from the end of the bonded portion of the sub head base to the main head base to the tip of the head chip is set to 2 mm or less, and the mode of the lead wire drawn from the winding is reduced.
The hardness of the head is 37 μm or less in the Shore-D range, so that the relative height difference of the head due to temperature change is 1 μm.
The following high precision can be achieved.

[0024]

As described above, the present invention has a Young's modulus of at least 5 × 10 ³ Kg / mm ² , which is made of a material that transmits ultraviolet light and has a head chip provided with a winding on one upper surface.
A plurality of sub-head bases having a density of 2.5 or less and a plate thickness of a minimum of 0.19 mm to which an amount necessary for height correction of adjacent heads is added, and a head chip mounting surface on the lower surface of the sub-head base A main head base having a surface which does not overlap with the plane fixed with an ultraviolet curable adhesive, and a shore for fixing a lead wire drawn from the winding along the sub head base and the main head base. With a configuration having a mold member having a D range hardness of 37 or less and an electro-mechanical transducer for displacing the main head base in the head height direction, a movable head device having a high resonance frequency can be obtained. The relative height of a plurality of mounted heads can be increased in accuracy. Therefore, the head can respond at a high speed in the special reproduction mode, and a good output can be obtained over the entire track. Thereby, a high-quality special reproduction image can be secured. Furthermore, a stable relative head height can be ensured even when used in a wide temperature environment, and high image quality can be stably ensured for a long time in a wide environment. Therefore, the practical effect is great.

[Brief description of the drawings]

FIG. 1 is a plan view and a side view of a movable head device according to an embodiment of the present invention.

FIG. 2 is a layout diagram of head height according to an embodiment of the present invention.

FIG. 3 is a dimensional diagram of a head portion according to an embodiment of the present invention.

FIG. 4 is a perspective view illustrating a head mounting method according to an embodiment of the present invention.

FIG. 5 is a side view illustrating a head mounting method according to an embodiment of the present invention.

FIG. 6 is an explanatory view of assembling a head portion according to the embodiment of the present invention.

FIG. 7 is an explanatory diagram of a method for processing a lead wire of a winding according to an embodiment of the present invention.

FIG. 8 is a side view of a lead wire mold part of a winding according to an embodiment of the present invention.

FIG. 9 is a diagram showing the relationship between the mold agent hardness and the change in head height when the temperature changes according to the embodiment of the present invention.

FIG. 10 is a cross-sectional view of the embodiment of the present invention during bimorph operation.

FIG. 11 is a plan view of a rotary magnetic recording / reproducing apparatus incorporating a conventional movable head device.

FIG. 12 is a layout diagram of tracks recorded by a rotary magnetic recording / reproducing apparatus incorporating a conventional movable head device.

FIG. 13 is a perspective view of a conventional movable head device.

FIG. 14 is an enlarged perspective view of a head portion of a conventional movable head device.

FIG. 15 is an enlarged cross-sectional view of a head portion after a lead wire processing.

[Explanation of symbols]

 17, 18 bimorph 19, 20, 21 fixing member 25 connecting member 23, 24 bent portion 26 main head base 27 screw 29 to 32 reproducing head chip 33 to 36 sub head base 41, 42 relay board 45 lead wire 46 Mold agent

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-5-334636 (JP, A) JP-A-6-60353 (JP, A) JP-A-6-168431 (JP, A) JP-A-5-168431 120658 (JP, A) JP-A-7-210841 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) G11B 5/52-5/53 G11B 5/56

Claims (1)

(57) [Claims] 1. A plurality of sub-head bases, each of which is made of a material that transmits ultraviolet light and has a head chip provided with a winding on one of its upper surfaces, and a planar surface that is attached to the lower surface of the sub-head base with the head chip bonding surface. Main head base with non-overlapping surfaces fixed with UV-curable adhesive,
A mold member for fixing a lead wire drawn from the winding along the sub head base and the main head base; and an electric member for displacing the main head base in a head height direction. A mechanical conversion element is provided, and the plurality of sub-head bases are required to correct the height of adjacent heads from a Young's modulus of 5 × 10 ³ Kg / mm ² or more, a density of 2.5 or less, and a plate thickness of at least 0.19 mm. And the distance from the end of the bonding portion of the sub head base to the main head base to the end of the head chip is 2
mm, wherein the hardness of the mold member is 37 or less in a Shore-D range.