JP2006012223A - Magnetic head actuator assembly - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a magnetic head actuator assembly which can be easily assembled and improved in assembling property.
A back yoke (63B) of a voice coil motor is fixed to a head lift body (52A) by a leaf spring member (66). The head lift body (52A) has a pair of upper projections (523) and one lower projection for hooking the leaf spring member on its upper and lower surfaces. The leaf spring member (66) has an upper surface portion (661), a lower surface portion (662), and a connecting portion (663). The upper surface portion (661) has a pair of upper protrusions (661a) having upper holes (661b) into which the pair of upper protrusions are inserted. The lower surface portion (662) has a lower protrusion (662a) having a lower hole (662b) into which the lower protrusion is inserted. The connecting portion (663) has a spring tongue piece (663a) that applies pressure to the back surface of the back yoke.
[Selection] Figure 9

Description

  The present invention relates to a magnetic tape drive such as a linear tape storage system represented by DLT (Digital Linear Tape) and LTO (Linear Tape Open), and more particularly to a magnetic head actuator assembly that moves a magnetic head in a vertical direction by a voice coil motor. .

  This type of magnetic tape drive has been developed as a “backup” system for hard disks in computer systems, and various linear storage systems have been proposed. For example, a digital linear tape drive that functions as a DLT is disclosed in, for example, Patent Document 1.

  A digital linear tape drive (hereinafter also simply referred to as “drive device”, “tape drive”, or “drive”) receives a tape cartridge (hereinafter also simply referred to as “cartridge”) having a single reel (supply reel). It has a built-in take-up reel. When the tape cartridge is mounted on the drive device, the magnetic tape is pulled out of the tape cartridge and taken up by a take-up reel via a head guide assembly (HGA). The head guide assembly is for guiding a magnetic tape (hereinafter also simply referred to as “tape”) drawn from the tape cartridge to the magnetic head. The magnetic head exchanges information between the magnetic tape and the magnetic head. The head guide assembly is generally composed of an aluminum plate having a boomerang shape and six large guide rollers each using a bearing.

  The head guide assembly is also called a tape guide assembly, which is disclosed in, for example, Patent Document 2. An example of the guide roller is disclosed in Patent Document 3.

  In general, a magnetic tape drive includes a substantially rectangular parallelepiped housing having a common base, as described in, for example, Japanese Patent Application Laid-Open No. H10-228707. The base has two spindle motors (reel motors). The first spindle motor has a spool (take-up reel) permanently attached to the base, and the spool is sized to receive a magnetic tape flowing at a relatively high speed. The second spindle motor (reel motor) is adapted to receive a removable tape cartridge. The removable tape cartridge is manually or automatically inserted into the drive through a slot formed in the drive housing. When the tape cartridge is inserted into the slot, the cartridge is engaged with a second spindle motor (reel motor). Before rotating the first and second spindle motors (reel motors), the tape cartridge is connected to a permanently mounted spool (take-up reel) by a mechanical buckling mechanism. Many rollers (guide rollers) positioned between the tape cartridge and the permanent spool guide the magnetic tape as it moves back and forth at a relatively high speed between the tape cartridge and the permanently mounted spool. To do.

  In the digital linear tape drive having such a configuration, an apparatus is required for the take-up reel to pull the tape from the supply reel. Such a pulling device is disclosed in Patent Document 5, for example. According to this publication, a take-up reel is connected to a take-up leader means (first tape leader), and a supply tape leader means (second tape leader) is fixed to a tape on the supply reel. The first tape leader has a mushroom-like tab at one end thereof. The second tape leader has a locking hole. The tab is engaged with the locking hole.

  Furthermore, a mechanism for joining the first tape leader to the second tape leader is also required. Such a joining mechanism is disclosed in Patent Document 6, for example.

  Further, in Patent Document 7, the end of the leader tape (second tape leader) is locked to the tape end hooking portion of the tape cartridge without requiring an ear piece protruding to the side of the leader tape. The structure of the locking portion of the leader tape that can be used is disclosed.

  Patent Document 8 discloses a lock system for preventing a take-up reel of a tape drive from rotating when a tape cartridge is not inserted into the drive.

  The magnetic tape drive further includes a magnetic head actuator assembly, which is positioned between the take-up spool and the tape cartridge on a tape path defined by a plurality of rollers. In operation, the magnetic tape flows back and forth between the take-up spool and the tape cartridge and closely approaches the magnetic head actuator assembly while flowing over a defined tape path. An example of such a magnetic head actuator assembly is disclosed in Patent Document 4 above.

  On the other hand, an example of a tape cartridge mounted on a digital linear tape drive is disclosed in Patent Document 9.

  Patent Document 10 discloses a “tape drive” in which a tape leader is pushed from a tape cartridge to a take-up reel without using a buckling mechanism or a winding leader.

  The magnetic head actuator assembly includes a tape head assembly (hereinafter also simply referred to as “head assembly”) and a head feed mechanism. The head assembly includes a pair of flexible printed circuits (a head) that extends in the vertical direction, a head holder that holds the magnetic head, and a magnetic head that is electrically connected to an external circuit. FPC). The head holder is also called a carriage.

  On the other hand, the head feed mechanism is for moving the head assembly up and down while holding the head assembly. As disclosed in Patent Document 4, the conventional head feed mechanism includes a threaded lead screw (threaded shaft) and mechanically moves the head assembly up and down by rotating the lead screw. (Linear motion). In other words, a “mechanical linear actuator” is employed as a conventional head feed mechanism.

  In such a mechanical linear actuator, the position control of the head assembly is generally performed by open loop control. In the DLT, the storage capacity is increased. In “DLT1” which is the first generation DLT, the normal storage capacity is 40 GB, and the storage capacity when compressed is 80 GB. In addition, in “DLT2” that is the second generation DLT, the normal storage capacity is 80 Gbytes, and the compressed storage capacity is 160 Gbytes. In addition, in “DLT3” which is the third generation DLT, the normal storage capacity is about 150 Gbytes, and the compressed storage capacity is about 300 Gbytes. With a DLT having such a storage capacity, a mechanical linear actuator can sufficiently cope.

  However, “DLT4”, which is the next generation (fourth generation) DLT, has a normal storage capacity of 300 Gbytes, a compressed storage capacity of 600 Gbytes, and a large capacity (high storage density). For this reason, when the above-described mechanical linear actuator is used as a linear actuator for DLT having a large storage density, it is difficult to accurately control the head assembly to a desired position.

  On the other hand, in order to solve such problems in the mechanical linear actuator, an “electromagnetic linear actuator” that moves the head assembly up and down (linearly) electromagnetically is adopted as the head feed mechanism to control the position of the head assembly. Has been proposed for performing closed loop (feedback) control (see, for example, Patent Document 11). Since the electromagnetic linear actuator employs a feedback control method as a control method, the head assembly can always be accurately controlled to a desired position even if the magnetic tape fluctuates up and down during traveling. .

  Such an electromagnetic linear actuator generally includes a fixed portion, a movable portion that holds a head assembly (an object to be lifted) up and down along the vertical direction with respect to the fixed portion, and a movable portion of the movable portion. It has a guide for restraining (regulating) movement other than the (lifting / lowering) direction, and a base for attaching this guide.

  Here, the electromagnetic linear actuator can be divided into two types. The first type is a “movable magnet type” electromagnetic linear actuator, which includes a magnet in the movable part and a coil in the fixed part. The second type is a “movable coil type” electromagnetic linear actuator, which includes a magnet and a yoke in a fixed portion and a coil in a movable portion.

  As described above, the electromagnetic linear actuator is suitable as a DLT actuator having a large storage capacity. However, as described above, the control method (control system) is completely different between the mechanical linear actuator and the electromagnetic linear actuator. For this reason, when using this electromagnetic linear actuator as a DLT linear actuator of a lower model (namely, the first generation or the second generation), the control system for the mechanical linear actuator that has been incorporated up to that point is used at all. Therefore, a new control system suitable for the electromagnetic linear actuator must be incorporated. That is, it is necessary to change the design of the lower-level model DLT.

  In order to solve such problems, as a fourth generation (upper model) DLT linear actuator (head feed mechanism) compatible with lower model DLTs, not only mechanical linear actuators, but also electromagnetic A “composite linear actuator” that can also operate as a linear actuator is considered. That is, the composite linear actuator is a combination of a mechanical linear actuator and an electromagnetic linear actuator. In such a composite type linear actuator, a mechanical linear actuator is used for rough position control (open loop control) of the head assembly, and an electromagnetic linear actuator is used for precise position control (closed loop control). It can be carried out.

  More specifically, the composite linear actuator is a mechanical linear actuator including a lead screw having a rotation center shaft extending in the axial direction and a main movable portion that linearly moves in the axial direction by the rotation of the lead screw. Including. The main movable portion operates as an electromagnetic linear actuator including a sub-fixed portion and a sub-movable portion that linearly moves in the axial direction with respect to the sub-fixed portion by electromagnetic force. The electromagnetic linear actuator is constituted by a voice coil motor (VCM). Therefore, the sub-fixed part is called a VCM fixed part, and the sub-movable part is called a VCM movable part. The sub fixed portion has a yoke and a magnet, and the sub movable portion includes an air-core coil. The air-core coil is fixed to a head holder (attachment portion) that holds the magnetic head. Such composite linear actuators are disclosed in, for example, Patent Documents 12 to 15.

  The super DLT which is a kind of magnetic tape drive employs the electromagnetic linear actuator or the composite linear actuator as a linear actuator. In super DLT, the position of the magnetic tape is detected using an optical pickup.

  More specifically, the optical pickup is disposed to face the magnetic head with a magnetic tape interposed therebetween. The magnetic tape has a magnetic recording surface on the front surface side and a reflective surface on the back surface side. While the magnetic tape is running, the magnetic recording surface of the magnetic tape is in sliding contact with the magnetic head. On the other hand, a dot pattern for position detection is formed on the reflecting surface of the magnetic tape along the tape running direction. Each dot is made of a non-reflective material. The optical pickup detects the position of the magnetic tape by detecting the dot pattern formed on the reflecting surface of the magnetic tape. The optical pickup detects the position of the magnetic tape using a three-beam method well known in the art.

  In the LTO, a servo track is recorded in advance on the magnetic recording surface side of the magnetic tape in parallel with the data track, and the magnetic head reads the servo track so that the position of the magnetic head is changed to the magnetic tape. Control to the correct position on.

  In the composite linear actuator described above, the mechanical linear actuator may be referred to as a head feed mechanism, and the electromagnetic linear actuator may be referred to as a voice coil motor. That is, the head feed mechanism is for performing coarse adjustment of the position of the magnetic head by moving the head assembly up and down, and the voice coil motor is for performing fine adjustment of the position of the magnetic head.

  A magnetic tape drive 10 that is a DLT to which the present invention is applied will be described with reference to FIG. FIG. 1 is a perspective view of a magnetic tape drive 10 that is a DLT, with the top cover removed. Therefore, unlike the super DLT, the magnetic tape drive 10 shown in FIG. 1 does not have an optical pickup attached to the magnetic head actuator assembly. However, the DLT will be described because it is useful for understanding the present invention. .

  The magnetic tape drive 10 is for receiving a tape cartridge (not shown), and incorporates a take-up reel 11 therein. The take-up reel 11 is also called a spool. The tape drive 10 includes a substantially rectangular parallelepiped housing (chassis) 12 having a common base. The base has two spindle motors (reel motors) 13 and 14. The first spindle motor 13 has a spool (winding reel) 11 permanently attached to the base of the housing 12, and the spool 11 receives a magnetic tape (not shown) that flows at a relatively high speed. The size is determined. The second spindle motor (reel motor) 14 is adapted to receive a removable tape cartridge. The removable tape cartridge is inserted into the tape drive 10 manually or automatically through the slot 16 formed in the housing 12 of the tape drive 10 along the insertion direction indicated by the arrow A.

  When the tape cartridge is inserted into the slot 16, the tape cartridge engages with the second spindle motor (reel motor) 14. Before the first and second spindle motors (reel motors) 13 and 14 are rotated, the tape cartridge is permanently attached to the spool (take-up reel) 11 by a mechanical buckling mechanism (not shown). Connected. Many rollers (guide rollers) 15 positioned between the tape cartridge and the permanent spool 11 are used when the magnetic tape moves back and forth at a relatively high speed between the tape cartridge and the spool 11 permanently attached. Guide it.

  The housing 12 is constituted by a sheet metal press chassis or an aluminum die cast chassis made of an iron-based magnetic material.

  The magnetic tape drive 10 further includes a magnetic head actuator assembly 20, which is disposed on a tape path (not shown) defined by the plurality of rollers 15 between the take-up reel 11 and the tape cartridge. Positioned between. During operation, the magnetic tape flows back and forth between the take-up spool 11 and the tape cartridge and is in close proximity to the magnetic head actuator assembly 20 while flowing on the defined tape path.

  FIG. 2 shows a magnetic head actuator assembly 20A for super DLT. The main difference from the DLT magnetic head actuator assembly 20 shown in FIG. 1 is that in the super DLT magnetic head actuator assembly 20A, the optical pickup 30 is attached to the DLT magnetic head actuator assembly 20 via the arm 40. It is being done.

  The magnetic head actuator assembly 20 includes a magnetic head 21 that extends in the vertical direction, and a head holder (carriage) 22 that holds the magnetic head 21 so as to be movable in the vertical direction. The head holder 22 is moved in the vertical direction by a head feed mechanism described later.

  The arm 40 is attached to the lower end side of the head holder (carriage) 22 using screws or the like. As shown in FIG. 2, the arm 40 is substantially L-shaped, and the optical pickup 30 is attached to the top thereof.

  As shown in FIG. 2, the magnetic head 21 and the optical pickup 30 are disposed to face each other with a space between them. That is, the optical pickup 30 is disposed to face the magnetic head 21 with the magnetic tape 42 interposed therebetween. The magnetic tape 42 has a magnetic recording surface 42a and a reflection surface (irradiation surface) 42b opposite to the magnetic recording surface 42a. While the magnetic tape 42 is running, the magnetic recording surface 42 a of the magnetic tape 42 is in sliding contact with the magnetic head 21. On the other hand, a dot pattern for position detection is formed on the reflecting surface 42b of the magnetic tape 42 along the tape running direction. Each dot is made of a non-reflective material. The optical pickup 30 detects the position of the magnetic tape 42 by detecting the dot pattern formed on the reflection surface 42 b of the magnetic tape 42. The optical pickup 30 detects the position of the magnetic tape using a three-beam method well known in this technical field.

  The optical pickup 30 includes a hologram unit 31, a diaphragm 33, a lens 35, and a lens holder 37. The lens holder 37 is hollow and holds the lens 35 therein. The hologram unit 31 is attached to one end of the lens holder 37. The diaphragm 33 is disposed between the hologram unit 31 and the lens 35.

  The hologram unit 31 includes a chip 311, a hologram 313, and a diffraction grating 315.

  Hereinafter, a conventional magnetic head actuator assembly 20 will be described with reference to FIGS. Since the illustrated magnetic head actuator assembly 20 is for DLT, the optical pickup 30 may be attached via the arm 40 as shown in FIG. The illustrated magnetic head actuator assembly 20 is a composite linear actuator. However, the illustrated composite linear actuator is different from those disclosed in Patent Documents 12 to 15, and the magnetic head 21 is linearly moved in the width direction of the magnetic tape 42 using a bearing (bearing) as described later. It is moved.

  FIG. 3 is an exploded perspective view of the magnetic head actuator assembly (composite linear actuator) 20. FIG. 4 is a perspective view showing the appearance of the magnetic head actuator assembly 20 as seen from the front side. FIG. 5 is a perspective view showing the appearance of the magnetic head actuator assembly 20 as seen from the back side. FIG. 6 is a plan view of the magnetic head actuator assembly 20. FIG. 7 is a front view of the magnetic head actuator assembly 20. 8 is a sectional view taken along line VIII-VIII in FIG. 3 to 8, the flexible printed circuit (FPC) is omitted. Further, as shown in FIG. 3, coordinate axes orthogonal to each other are represented by an X axis, a Y axis, and a Z axis. Here, the X-axis direction is the left-right direction, the Y-axis direction is the front-rear direction, and the Z-axis direction is the up-down direction.

  The magnetic head actuator assembly 20 includes a magnetic head 21 that extends in the vertical direction, and a head holder (carriage) 22 that holds the magnetic head 21 so as to be movable in the vertical direction. The magnetic head 21, the carriage 22, and the flexible printed circuit constitute a head assembly. The head holder 22 is moved in the vertical direction by a head feed mechanism described below.

  The carriage 22 includes a carriage main body 221, a head mounting portion 222 provided on the front surface of the carriage main body 221 for mounting the magnetic head 21, and a pair of carriage shafts 223 extending from the carriage main body 221 in the left-right direction. The carriage body 221 is formed with a through hole 221a through which the linear bearing shaft 224 penetrates in the vertical direction. Therefore, the head assembly and the head feed mechanism described below are assembled through the linear bearing shaft 224.

  The head feed mechanism includes a threaded lead screw 51 having a rotation center axis extending in the vertical direction as a rotation member, and a head lift body that moves up and down along the rotation center axis as the lead screw 51 rotates as a linear movement member. 52 and a backlash prevention mechanism 53 for preventing backlash of the magnetic head actuator assembly 20.

  The lead screw 51 has a lead screw gear 54 that rotates the lead screw 51 around the rotation center axis by other driving means (for example, a stepping motor) on the lower end side thereof.

  The head lift body 52 has a substantially rectangular parallelepiped shape, and a semi-cylindrical opening (not shown) is formed on the back side. The head lift body 52 moves the head assembly up and down while holding the head assembly up and down. That is, the head lift body 52 supports the magnetic head 21 so as to be movable up and down. A backlash prevention mechanism 53 is disposed inside the semi-cylindrical opening of the head lift body 52.

  The backlash prevention mechanism 53 includes a preload bush 531 having a thread groove that engages with the lead screw 51 and a preload spring 532 when the backlash prevention mechanism 53 is disposed inside the semi-cylindrical opening of the head lift body 52.

  The lead screw 51 engages with a thread groove of a bearing 55 provided in the head lift body 52. The rotation of the lead screw 51 around the rotation center axis moves the head lift body 52 in the vertical direction, which is the direction in which the rotation center axis extends, in cooperation with the backlash prevention mechanism 53. A substantially U-shaped guide portion 57 is attached to the lower surface of the head lift body 52. The guide portion 57 is fitted into a guide bar (not shown) and attached so as to be slidable in the vertical direction, and prevents the head lift body 52 from rotating.

  The head lift body 52 has a center shaft 521 extending in the left-right direction from both side surfaces on the front side. The head lift body 52 has a pair of protrusions 522 extending forward from the upper surface and the lower surface, and the pair of protrusions 522 are through holes into which both ends of the linear bearing shaft 244 are inserted. 522a is formed.

  The head lift body 52 is attached with a magnetic circuit (magnet or yoke) that constitutes a sub-fixing portion of an electromagnetic linear actuator (voice coil motor).

  More specifically, the magnetic circuit includes a magnet 61 that is magnetized in the plate thickness direction and in opposite directions at the upper and lower portions, a center yoke 62 attached to the back surface of the head lift body 52, and a back yoke 63. The back yoke 63 has a main surface that is disposed in parallel and spaced apart from the center yoke 62, and an upper end portion 631 and a lower end portion 632 are bent substantially at right angles to the main surface by pressing. That is, the back yoke 63 has a U-shaped cross section. The upper end 631 and the lower end 632 of the back yoke 63 are in contact with the upper end and the lower end of the center yoke 62, respectively. The magnet 61 is attached in contact with the main surface (inner surface) of the back yoke 63.

  The center yoke 62 has an upper notch 62a and a lower notch 62b at the upper end and the lower end, respectively. Further, the upper end portion 631 of the back yoke 63 has an upper end convex portion 631 a that fits into the upper notch portion 62 a of the center yoke 62, and the lower end portion 632 of the back yoke 62 fits into the lower notch portion 62 b of the center yoke 62. It has a lower end convex part 632a. The upper end convex portion 631a of the back yoke 63 projects forward longer than the lower end convex portion 632a, and a hole 631b through which the screw 64 passes is formed at the tip end side. By screwing a screw 64 into the upper surface on the back side of the head lift body 52 through the hole 631a, the back yoke 63 of the magnetic circuit is fixedly attached to the head lift body 52.

  Next, the sub movable part of the electromagnetic linear actuator (voice coil motor) will be described.

  The sub movable portion includes a coil 71 disposed between the magnet 61 of the magnetic circuit and the center yoke 62, a coil holder 72 for holding the coil 71, and a pair of arms provided on both side surfaces of the head lift body 52. 73.

  More specifically, the coil holder 72 has a substantially rectangular shape that is long in the left-right direction. Cutouts 72 a are formed at the left and right ends of the coil holder 72. In addition, two screw holes 72b are formed on the left and right ends of the coil holder 72 in the vertical direction with a notch 72a therebetween.

  On the other hand, the pair of arms 73 has a rectangular parallelepiped shape that is substantially long in the front-rear direction. On the back surface of the pair of arms 73, a protrusion 73 a that fits into the notch 72 a of the coil holder 72 is formed. In addition, both ends of the coil holder 72 are fixed to the back surfaces of the pair of arms 72 with four screws 74 through four screw holes 72b.

  Further, a through hole 73 b through which the center shaft 521 of the head lift body 52 passes is formed in front of the center of the pair of arms 73. In other words, the pair of arms 73 is attached to the center shaft 521 of the head lift body 52 via the pair of bearings 75, the spring 76, and the retaining member 77 so as to be rotatable around the center shaft 521.

  Further, a through hole 73 c through which the carriage shaft 223 of the carriage 22 passes is formed at the front end portions of the pair of arms 73. That is, the pair of arms 73 supports the carriage 22 so as to be rotatable around the carriage shaft 223 via the pair of bearings 78.

  As described above, the movement of the carriage 22 is restricted by the linear bearing shaft 224 so as to be movable only in the vertical direction. Accordingly, when the pair of arms 73 rotate around the center shaft 521 of the head lift body 52, the carriage (head holder) 22 moves up and down along the linear bearing shaft 224.

  Anyway, the voice coil motor is for moving the magnetic head 21 up and down.

JP-A-9-198639 Japanese National Patent Publication No. 9-500753 JP 2000-100025 A JP 2000-501547 A Japanese Patent Publication No. 3-7595 Japanese Patent Publication No. 6-39027 JP 2000-100116 A Japanese Patent Laid-Open No. 11-86381 JP 2000-149491 A Japanese Patent Laid-Open No. 11-316991 JP 2002-198219 A JP 2004-87654 A JP 2004-87050 A JP 2004-86967 A JP 2004-86973 A

  As described above, in the conventional magnetic head actuator assembly (composite linear actuator) 20, the magnetic circuit (back yoke) of the voice coil motor is fixed to the head lift body 52 by screwing with the screws 64. ing.

  However, when the fixing method by screwing is adopted, there are problems as described below. First, when the screw 64 is a magnetic screw, there is a problem that it is difficult to assemble the screw 64 because the screw 64 is attracted to the magnet 61 constituting the magnetic circuit. Second, when a non-magnetic screw is used as the screw 64, the non-magnetic screw is generally expensive. Third, since the cost is increased if the main components (head lift body 52, etc.) of the magnetic head actuator assembly are made of metal, the main components are made by screwing when the main components are made of resin. The part may be distorted and the movement may be adversely affected.

  On the other hand, in order to eliminate such a problem, a method of fixing the magnetic circuit (back yoke) to the head lift body 52 not by screwing but by bonding may be considered. However, the fixing method by bonding has a problem that reassembly is not possible.

  Therefore, an object of the present invention is to provide a magnetic head actuator assembly that can easily assemble a magnetic circuit (back yoke) to a head lift body.

  It is another object of the present invention to provide a magnetic head actuator assembly that does not cause distortion problems during assembly.

  Still another object of the present invention is to provide a magnetic head actuator assembly that can be easily reassembled.

  Other objects of the invention will become apparent as the description proceeds.

  According to the present invention, a magnetic head (21), a head lift body (52A) that supports the magnetic head so as to be movable up and down, and a voice coil motor (61, 62, 63A, 71) and a leaf spring member (66) for fixing the yoke (63B) of the voice coil motor to the head lift body (52A). A head actuator assembly is obtained.

  In the magnetic head actuator assembly, the voice coil motor includes a magnetic circuit (61, 62, 63A) and a coil (71). The magnetic circuit includes, for example, a center yoke (62) attached to the head lift body (52A), a back yoke (63A) having a U-shaped cross section attached to both ends of the center yoke, and an inner surface of the back yoke. And a magnet (61) attached in contact with the magnet. The coil is disposed between the center yoke and the magnet. In this case, the leaf spring member (66) has a U-shaped cross section so as to cover the back surface of the back yoke.

  The head lift body (52A) preferably has a pair of upper projections (523) and one lower projection for hooking the leaf spring member on the upper and lower surfaces thereof. In this case, the leaf spring member (66) includes an upper surface portion (661) covering the upper end portion (631) of the back yoke, a lower surface portion (662) covering the lower end portion (632) of the back yoke, A connecting portion (663) for connecting the upper surface portion and the lower surface portion so as to cover the back surface of the yoke. The upper surface portion (661) includes a pair of upper protrusions (661a) having upper holes (661b) into which the pair of upper protrusions are inserted, and the lower surface portion (662) includes the lower protrusions. And a lower protrusion (662a) having a lower hole (662b) into which the connecting portion (663) is inserted, and the connecting portion (663) is bent forward at the center thereof to apply pressure to the back surface of the back yoke. It may have a tongue piece (663a).

  The magnetic head actuator assembly further includes a pair of flexible printed circuits (23) for electrically connecting the magnetic head (21) and an external circuit. In this case, it is preferable that the leaf spring member further includes a pair of ears (664) extending from the connecting portion in the left-right direction and used for stably assembling the pair of flexible printed circuits. The pair of ears (664) has an extension part (664a) extending upward, and the extension part has its upper end bent forward to mount the flexible printed circuit. (664b) and a bending portion for positioning (664c) that is bent backward at the inner edge to position the flexible printed circuit.

  The reference numerals in the parentheses are given for ease of understanding, and are merely examples, and of course are not limited thereto.

  In the present invention, as a method of pressing the yoke of the magnetic circuit against the head lift body, the plate spring member is used to hook and fix the head to the head lift body, so that the assemblability can be improved. At the same time, the conventional distortion problem can be solved and reassembly can be easily performed. Further, by adding the ear portion and the positioning bending portion to the leaf spring member, the flexible printed circuit electrically connected to the magnetic head can be stably assembled without increasing the number of components.

  A magnetic head actuator assembly 20B according to an embodiment of the present invention will be described with reference to FIGS. Since the illustrated magnetic head actuator assembly 20B is for DLT, the optical pickup 30 can be attached via the arm 40 as shown in FIG. The illustrated magnetic head actuator assembly 20 is a composite linear actuator, and the magnetic head 21 is linearly moved in the width direction of the magnetic tape 42 using a bearing.

  FIG. 9 is an exploded perspective view of the magnetic head actuator assembly (composite linear actuator) 20B. FIG. 10 is a perspective view showing the appearance of the magnetic head actuator assembly 20A as seen from the front side. FIG. 11 is a perspective view showing the appearance of the magnetic head actuator assembly 20B as seen from the back side.

  The illustrated magnetic head actuator assembly 20B uses a leaf spring member 66 instead of the screw 64 as a fixing member for a magnetic circuit (yoke), and the head lift body and the back yoke are slightly different from the conventional ones as will be described later. Except for the changes, the conventional magnetic head actuator assembly shown in FIGS. 3 to 8 has the same configuration. Accordingly, reference numerals 52A and 63A are assigned to the head lift body and the back yoke, respectively. Also, components having the same functions as those of the conventional constituent elements are denoted by the same reference numerals, and description thereof is omitted for the sake of simplicity.

  Unlike the conventional back yoke 63, the back yoke 63A has an upper end protruding portion 631a protruding forward by the same length as the lower end protruding portion 632a, and no hole 631b is formed on the tip side thereof.

  The head lift body 52A has a pair of upper projections 523 for hooking a leaf spring member 66 described later on both corners on the back side of the upper surface. Further, although not shown, the head lift body 52A has one lower protrusion for hooking the leaf spring member 66 also in the vicinity of the base where the guide portion 57 on the back side of the lower surface extends.

  The leaf spring member 66 is for fixing the back yoke 63A of the magnetic circuit to the head lift body 52A. Specifically, the leaf spring member 66 has a U-shaped cross section so as to cover the back yoke 63A from the back side. The plate spring member 66 includes an upper surface portion 661 covering the upper end portion 631 of the back yoke 63A, a lower surface portion 662 covering the lower end portion 632 of the back yoke 63A, and an upper surface portion 661 and a lower surface portion 662 so as to cover the back surface of the back yoke 63A. And a pair of ears 664 extending from the connection part 663 in the left-right direction and used for stably assembling a flexible printed circuit (FPC) to be described later. The illustrated leaf spring member 66 is made of metal.

  The upper surface portion 661 has a pair of upper protrusions 661a extending forward from the left and right front ends and having an upper hole 661b into which the upper protrusion 523 of the head lift body 52A is inserted. On the other hand, the lower surface portion 662 has a lower protrusion 662a that extends forward from the front right corner and has a lower hole 662b into which the lower protrusion of the head lift body 52A is inserted. The connecting portion 663 has a spring tongue piece 663a that is bent forward at the center thereof and applies pressure to the back surface of the back yoke 63A.

  On the other hand, the pair of ear portions 664 has an extending portion 664a extending upward. The extended portion 664a has an upper end bent forward and an FPC mounting portion 664b for mounting an FPC, which will be described later, and an FPC positioning bent portion, which is bent backward at the inner edge to position the FPC, which will be described later. 664c.

  According to such a configuration of the leaf spring member 66, when the back yoke 63A constituting the magnetic circuit is fixed to the head lift body 52A, the upper hole 661b and the lower hole 662b are respectively connected to the upper protrusion 523 and the upper protrusion 523 of the head lift body 52A. By hooking on the lower projection, the back yoke 63A can be easily fixed to the head lift body 52A. As a result, the assembly can be easily performed, and the problems of distortion and reassembly, which are problems in the conventional fixing method, can be solved.

  A magnetic head actuator assembly (composite linear actuator) 20B having (added to) a flexible printed circuit (FPC) will be described with reference to FIGS.

  FIG. 12 is a perspective view showing the appearance of the magnetic head actuator assembly 20B having the FPC as seen from the front side. FIG. 13 is a perspective view showing the appearance of the magnetic head actuator assembly 20B as seen from the back side. 14A is a plan view of the magnetic head actuator assembly 20B, and FIG. 14B is a partially enlarged view showing a portion B of FIG. 14A in an enlarged manner. FIG. 15 is a front view of the magnetic head actuator assembly 20B. FIG. 16 is a right side view of the magnetic head actuator assembly 20B. 17A is a rear view of the magnetic head actuator assembly 20B, and FIG. 17B is a partially enlarged view showing a portion C of FIG. 17A in an enlarged manner.

  The pair of flexible printed circuits (FPC) 23 are for electrically connecting the magnetic head 21 and an external circuit (not shown). The pair of flexible printed circuits 23 and the magnetic head 21 are electrically connected by well-known wire bonding.

  The pair of flexible printed circuits 23 is pulled out from the magnetic head 21 to the rear of the magnetic head actuator assembly 20B through the head lift body 52A and then mounted on the FPC mounting portion 664b of the ear portion 664 of the leaf spring member 66. Is done. Further, by providing the FPC mounting portion 664b, the edge of the leaf spring member 66 does not directly contact the FPC 23, so that the FPC 23 can be prevented from being damaged. Thereafter, as shown in FIGS. 14B and 17B, the pair of flexible printed circuits 23 is positioned by the FPC positioning bending portion 664c of the ear portion 664 of the leaf spring member 66.

  Thus, by adding the ear | edge part 664 and the bending part 664c for FPC positioning to the leaf | plate spring member 66, a pair of flexible printed circuit 23 can be assembled stably, without increasing a number of parts.

  Although the present invention has been described with reference to preferred embodiments, it is obvious that various modifications can be made by those skilled in the art without departing from the spirit of the present invention. For example, in the embodiment described above, a metal member is used as the leaf spring member 66, but a resin member may be used. In the above-described embodiment, only the example in which the composite linear actuator is employed as the magnetic head actuator assembly has been described. However, it is obvious that the present invention can be applied to the electromagnetic linear actuator as well.

1 is a perspective view showing a magnetic tape drive including a magnetic head actuator assembly for DLT to which the present invention is applied, with a top cover removed. FIG. It is a partial cross section front view which shows the structure of the magnetic head actuator assembly for super DLT. It is a disassembled perspective view of the conventional magnetic head actuator assembly (composite type linear actuator). FIG. 4 is a perspective view showing the appearance of the magnetic head actuator assembly shown in FIG. 3 as viewed from the front side. FIG. 4 is a perspective view showing an appearance of the magnetic head actuator assembly shown in FIG. 3 as viewed from the back side. FIG. 4 is a plan view of the magnetic head actuator assembly shown in FIG. 3. FIG. 4 is a front view of the magnetic head actuator assembly shown in FIG. 3. It is VIII-VIII sectional drawing in FIG. 1 is an exploded perspective view of a magnetic head actuator assembly (composite linear actuator) according to an embodiment of the present invention. FIG. 10 is a perspective view showing the appearance of the magnetic head actuator assembly shown in FIG. 9 as viewed from the front side. FIG. 10 is a perspective view showing the appearance of the magnetic head actuator assembly shown in FIG. 9 as viewed from the back side. It is a perspective view which shows the external appearance of the magnetic head actuator assembly provided with FPC in the state seen from the front side. FIG. 13 is a perspective view showing an appearance of the magnetic head actuator assembly shown in FIG. 12 as viewed from the back side. (A) is a plan view of the magnetic head actuator assembly shown in FIG. 12, and (B) is a partially enlarged view showing a portion B in (A). FIG. 13 is a front view of the magnetic head actuator assembly shown in FIG. 12. FIG. 13 is a right side view of the magnetic head actuator assembly shown in FIG. 12. (A) is a rear view of the magnetic head actuator assembly shown in FIG. 12, and (B) is a partially enlarged view showing a portion C of (A) in an enlarged manner.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Magnetic tape drive 20B Magnetic head actuator assembly 21 Magnetic head 22 Head holder (carriage)
23 Flexible Printed Circuit (FPC)
52A head lift body 523 upper projection 61 magnet 62 center yoke 63A back yoke 631 upper end 632 lower end 66 leaf spring member 661 upper surface 661a upper protrusion 661b upper hole 662 lower surface 662a lower protrusion 662b lower hole 663 connecting part 663a Spring tongue piece 664 Ear portion 664a Extension portion 664b FPC mounting portion 664c FPC positioning bending portion 71 Coil

Claims (5)

  A magnetic head actuator assembly comprising: a magnetic head; a head lift body that supports the magnetic head so as to move up and down; and a voice coil motor for moving the magnetic head up and down. A magnetic head actuator assembly comprising a leaf spring member for fixing to a lift body.   The voice coil motor includes a magnetic circuit and a coil, and the magnetic circuit includes a center yoke attached to the head lift body, a U-shaped back yoke having both ends attached to both ends of the center yoke, A magnet mounted in contact with the inner surface of the back yoke, the coil is disposed between the center yoke and the magnet, and the leaf spring member covers the back surface of the back yoke. The magnetic head actuator assembly according to claim 1, wherein the magnetic head actuator assembly has a letter shape. The head lift body has a pair of upper projections and one lower projection for hooking the leaf spring member on the upper and lower surfaces thereof,
The leaf spring member includes an upper surface portion covering the upper end portion of the back yoke, a lower surface portion covering the lower end portion of the back yoke, and a space between the upper surface portion and the lower surface portion so as to cover the back surface of the back yoke. A connecting portion to be connected,
The upper surface portion has a pair of upper protrusions having upper holes into which the pair of upper protrusions are inserted, and the lower surface portion has lower protrusions having lower holes into which the lower protrusions are inserted. The magnetic head actuator assembly according to claim 2, wherein the connecting portion includes a spring tongue piece that is bent forward at a central portion thereof to apply pressure to the back surface of the back yoke. The magnetic head actuator assembly further includes a pair of flexible printed circuits for electrically connecting the magnetic head and an external circuit,
The said leaf | plate spring member is further provided with a pair of ear | edge part extended in the left-right direction from the said connection part, and being used in order to assemble the said pair of flexible printed circuits stably, The Claim 3 characterized by the above-mentioned. A magnetic head actuator assembly as described. The pair of ear portions has an extending portion extending upward, and the extending portion has an upper end bent forward and a mounting portion on which the flexible printed circuit is mounted and an inner edge to the rear. 5. The magnetic head actuator assembly according to claim 4, further comprising a bending portion for positioning for bending and positioning the flexible printed circuit.

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