JP2005190612A - Head actuator and tape drive incorporating same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce the overall weight of a head assembly so that a high response property is not deteriorated, even when a fine adjustment means by a VCM is provided to make a dual stage position adjustment. <P>SOLUTION: The head assembly 80 in which a magnetic head 81 is integrated with a carriage arm 83 thereof is formed. A mechanism for holding the magnetic head 81, as well as the VCM 84 by a permanent magnet and a coil, is mounted at the opposite end of the magnetic head 81 of the head assembly 80. The movement in the position of the magnetic head 81 by the driving of the VCM 84 is made into a rotational movement by the rotational axis of a rotational shaft 74, in which the distance from the magnetic head 81 to the fulcrum of the rotational axis is made large. Thus, the movement of the magnetic head 81 causing the inclination of the head with respect to the direction perpendicular to a tape recording surface, namely the positional variation by the angle, is made small. Accordingly, the magnetic head 81 is linearly moved in a fine range, and the high-speed response property can be secured by constituting the overall weight of the carriage arm 83 at the minimum. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention is used in a high capacity tape drive, and in a configuration in which the position of the magnetic head is finely adjusted by a voice coil motor, the structure of the head assembly on which the voice coil motor is mounted is simplified, weight is reduced, and high-speed response is ensured. In addition, the present invention relates to a head actuator that can employ a magnetic sensor as a position sensor that drives a voice coil motor, and a tape drive equipped with the head actuator.

  A conventional head actuator is disclosed, for example, in Patent Document 1 below.

  First, a tape drive 10 including an associated magnetic tape head actuator assembly 20 will be described with reference to FIG. FIG. 1 is a plan view showing the tape drive with the top cover removed.

  The 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 take-up reel 11 permanently attached to the base of the housing 12, and the take-up reel 11 receives a magnetic tape (not shown) that flows at a relatively high speed. The size is fixed. The second spindle motor 14 is adapted to receive a removable tape cartridge. The removable tape cartridge is inserted into the drive 10 manually or automatically along a predetermined insertion direction through a slot 16 formed in the housing 12 of the drive 10.

  When the tape cartridge is inserted along the slot 16, the cartridge is engaged with the second spindle motor 14. Before rotating the first and second spindle motors 13 and 14, the tape cartridge is connected to a permanently mounted take-up reel 11 by a mechanical buckling mechanism (not shown). Many rollers (guide rollers) 15 positioned between the tape cartridge and the take-up reel 11 of the permanent spool allow the magnetic tape to move between the tape cartridge and the take-up reel 11 permanently attached at a relatively high speed. Guide it when moving back and forth.

  In addition, the housing 12 shall be comprised with the sheet-metal press chassis which consists of an iron-type magnetic body.

  The tape drive 10 further includes a magnetic tape head actuator assembly 20 which is disposed on a magnetic tape path (not shown) defined by the plurality of rollers 15 and a take-up spool 11 and a tape cartridge. Is positioned between. In 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 head actuator assembly 20 while flowing over a defined magnetic tape path.

  Next, an outline of the head actuator assembly 20 will be described with reference to FIG. FIG. 2 is an exploded perspective view showing the overall components by disassembling the head actuator assembly 20 into a tape head assembly 30 and a head feed mechanism 40.

  The head actuator assembly 20 is disposed on the base of the housing 12 with a tape head assembly 30 that moves on the magnetic tape surface in close proximity to the magnetic tape. On the base of the housing 12, a guide bar 17 for moving the magnetic tape head assembly 30 up and down in the vertical direction with respect to the base of the housing 12 is further provided.

  As illustrated, the head actuator assembly 20 includes a tape head assembly 30 and a head feed mechanism 40. Here, the vertical direction to the base plane of the housing 12 in FIG. 1, that is, the extending direction of the guide bar 17 is the vertical direction.

  The tape head assembly 30 includes a magnetic head 31 that extends in the vertical direction, a head holder 32 that holds the magnetic head 31 on one surface (hereinafter, front surface), and a magnetic head 31 and an external circuit (not shown). And a pair of flexible printed circuits (hereinafter abbreviated as FPCs) 33 extending to the other surface (hereinafter referred to as the back surface) side. The tape head assembly 30 is assembled and fixed to the head lift body 42 by screwing screws 34 into the head lift body 42 of the head feed mechanism 40.

  As a result, the lead screw 41 of the head feed mechanism 40 having the rotation center axis in the vertical direction is disposed on the back side of the head holder 32, and the head lift body 42 that penetrates the lead screw 41 is rotated by the lead screw 41 to cause the tape head assembly. 30 will be moved up and down.

  Here, an outline of the structure of the head feed mechanism 40 will be described.

  The main part of the head feed mechanism 40 includes a threaded lead screw 41 having a rotation center axis extending in the vertical direction, a head lift body 42 that moves up and down along the rotation center axis according to the rotation of the lead screw 41, and a head The backlash preventing mechanism 43 that prevents backlash of the actuator assembly 20 is configured.

  The lead screw 41 has a lead screw gear 44 that rotates the lead screw 41 around the rotation center axis by other driving means on the lower end side thereof.

  The head lift body 42 moves the tape head assembly 30 up and down while holding the tape head assembly 30. The head lift body 42 has a backlash prevention mechanism 43 disposed inside the hollow opening of the semi-cylindrical portion 423.

  The lead screw gear 44 rotates the lead screw 41 that is directly coupled with a coaxial rotation center axis, for example, by driving a step motor. The rotation of the lead screw 41 around the rotation center axis moves the head lift body 42 in a linear direction in the direction in which the rotation center axis extends in cooperation with the backlash prevention mechanism 43.

  As described above, the head lift body 42 is integrally formed by a resin mold. That is, the head lift body 42 is obtained by integrally forming a bottom surface portion 421, a ceiling portion 422, a semi-cylindrical portion 423, and a bearing portion 45 with a resin mold.

  The head actuator having such a structure is practically sufficient for a tape having a conventional capacity.

  However, in a high capacity tape, the track density increases and the distance between tracks running in the length direction of the tape is becoming extremely narrow. Therefore, the magnetic head cannot be positioned sufficiently if the head lift body described above is linearly moved in the direction perpendicular to the track direction of the magnetic tape by the rotation of the lead screw directly connected to the lead screw gear driven by the step motor. It is necessary to ensure finer position adjustment.

  On the other hand, recently, for such fine adjustment, there is a voice coil motor (hereinafter abbreviated as VCM) widely used for an HDD (hard disk drive) or an actuator of a micromachining machine, and the head actuator has already been used. Applied. However, there is no patent document of this type applied to a magnetic tape head actuator. The VCM is an electrodynamic type vibration device, which is a developmental application of the principle of a speaker that vibrates cone paper at a high frequency. In other words, using a permanent magnet and a coil, when the coil is placed in the magnetic field of a permanent magnet and a current is passed through the coil, the principle that Fleming's left hand law generates a force perpendicular to the magnetic field and current is linearly driven Therefore, there is a need for a mechanism that linearly moves in a direction perpendicular to the track direction of the magnetic tape.

  Such a structure requires a linear motion for fine adjustment by the VCM in the same direction as the head feed mechanism. Therefore, since the VCM uses its own driving force, the VCM is mounted on the head assembly having the magnetic head to be moved, and the magnetic head position detection position for detecting the magnetic head position for fine adjustment and driving the VCM. It is desirable to mount the sensor member on the magnetic head side. This is because the VCM requires a driving force that loads the weight of the head assembly in a direction that coincides with the direction of movement of the head feed mechanism. Therefore, the VCM is more powerful due to the complexity of the structure and the increased driving force. Inevitable.

  As a solution to this problem, there is a structure in which the head feed mechanism and the head assembly are coupled by a rotating shaft having a track direction of the magnetic tape, and the magnetic head at the tip of the head assembly is rotated by the driving force of the VCM. However, this rotational movement causes the tip of the magnetic head to move relative to the direction of movement of the magnetic head and tilt in the direction perpendicular to the tape recording surface, that is, in the direction of the arrow indicated by the AA line in the head actuator assembly 20 of FIG. Therefore, a mechanism for making the rotational motion linear is necessary, and the complexity of the structure and the increase in the number of parts are inevitable.

  When the rotary shaft is used in this way, a permanent magnet and a coil, which are driving members of the VCM, are arranged at the force point at the other end of the head assembly including the rotary shaft as a fulcrum and having a magnetic head to be moved at one end. When the head feed mechanism is moved, the rotation axis position should be the center of gravity of the head assembly and the weight balance between the magnetic head side and the VCM side is necessary to avoid the head assembly from rotating about the rotation axis. It is.

Japanese Patent Laid-Open No. 2003-203318 (FIGS. 1, 2, and 6)

  A problem to be solved is a high-capacity tape drive or a head actuator used therefor, which is provided with fine adjustment means by a VCM (voice coil motor) to provide two-stage position adjustment, and head feed constituting the head actuator. When considering the connection structure between the mechanism and the head assembly and the high-speed response of the VCM, the position of the rotating shaft serving as a fulcrum is reduced to the center of gravity between the magnetic head and the VCM driving member in order to reduce the driving force. Although the weight on the head side and the weight on the VCM side are balanced, it is necessary to reduce the total weight of the head assembly in order to obtain high-speed response.

  The present invention is a high-capacity tape drive or a head actuator used therefor, and it is possible to suppress an increase in the driving force of the VCM and provide high-speed response even if a two-stage position adjustment is provided by means of fine adjustment means by the VCM. In order to achieve the purpose of securing, a position sensor member having, for example, a position sensor magnet (85) and a position sensor (86) for driving a VCM (84) for finely adjusting the position of the magnetic head is provided on the VCM (84) side. The main feature is to do. With this configuration, the weight on the magnetic head side with respect to the rotation axis (75) at the center of gravity can be limited to only the magnetic head (81) as a component, so that the additional weight on the VCM side for weight balance can be reduced. .

  Furthermore, in order to achieve the objective of reducing the assembly man-hours without using extra parts, the magnetic material deployed at one end of the integrated head assembly (80) in a limited size. By increasing the distance from the head (81) to the fulcrum of the rotating shaft (75), the magnetic head (81) is moved by driving the VCM (84) provided at the other end, that is, perpendicular to the tape recording surface. The change in tilt of the magnetic head in the direction can be reduced, and the magnetic head can be moved linearly in parallel with the tape surface.

  That is, as the head assembly (80), the magnetic head (81) and the VCM (84) are attached to the carriage (83) and integrally formed, and the magnetic head (81) is linearly moved in a minute range by a rotating mechanism having a long stroke. Move up. With such a simplified structure, the number of parts and the number of assembly steps can be reduced. Further, in the head assembly (80), a member of the VCM (84) other than the magnetic head (80) and a position sensor member for fine adjustment (85, 85) are arranged at the end opposite to the side where the magnetic head (81) is provided. 86) is installed to balance the weight at the rotational axis position.

  That is, the present invention is used in a high-capacity tape drive and is applied to a head actuator including a head feed mechanism (70) and a head assembly (80). The head feed mechanism (70) positions the magnetic head (81) by moving it roughly in a direction perpendicular to the tape running direction, for example, by a step motor. The head assembly (80) is composed of a permanent magnet and a coil that finely position a head holder (82) for mounting the magnetic head (81) on one end of the carriage arm (83) in the direction perpendicular to the track of the tape on the other end. Each has a configured VCM (84) and position sensor members (85, 86). Normally, since the track runs in the length direction of the tape, the moving direction of the magnetic head (81) coincides with the driving direction of the head feeding mechanism (70) and the VCM (84).

  Specifically, in the head actuator assembly according to the present invention, the head feed mechanism (70) and the head assembly (80) are coupled by forming a fulcrum on a line perpendicular to the moving direction of the head feed mechanism (70). When the assembly (80) rotates using the straight line formed by the fulcrum by driving the VCM (84) as the rotation axis (74), the fulcrum position and configuration in which the magnetic head (81) moves only within a limited range of linear movement. Further, a weight member other than the magnetic head (81) attached, for example, a position sensor (86) for detecting the position by the position sensor magnet (85) is provided on the VCM (84) side as a position sensor member, It is characterized by balancing.

  In such a head actuator, the rotation shaft (74) by the fulcrum can be positioned in the vicinity of the VCM (84) by the permanent magnet and coil provided at the opposite end to the magnetic head (81). Further, position sensor members (85, 86) are further provided at the end portions where the VCM (84) is present. Accordingly, in the integrated head assembly (80), only the magnetic head (81) is attached on both sides of the rotary shaft (74), that is, on the side of the magnetic head having a long distance from the fulcrum, and the remaining members have a short distance. Since it is placed at the end of the VCM drive side and balanced, the overall weight of the head assembly (80) can be minimized.

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

  The head actuator forms a head assembly in which a magnetic head and its carriage are integrated. In this head assembly, a VCM composed of a permanent magnet and a coil is provided at the opposite end of the magnetic head, and the magnetic head is driven by the VCM. The position movement is a rotational movement by the rotation axis. However, in the present invention, the head actuator is provided with a fine adjustment position sensor member that can be separated from the magnetic head at the tip of the VCM drive member mounting side, and the position of the rotation shaft serving as a fulcrum is determined between the magnetic head and the VCM drive member. The weight on the magnetic head side and the weight on the VCM side are balanced as the center of gravity position in the middle. For this reason, the fine adjustment position sensor member is also weighted on the VCM side with respect to the weight on the magnetic head side determined by the magnetic head, so that the weight of the fine adjustment position sensor member conventionally weighted on the magnetic head side. Not only is reduced, but also there is an effect that the weight of the entire head assembly can be reduced by eliminating the need for extra load weighting on the VCM side.

  Further, since the distance from the magnetic head to the fulcrum of the rotating shaft is increased, the movement of the magnetic head, that is, the position change due to the angle, which becomes the inclination of the head in the direction perpendicular to the tape recording surface can be reduced. Therefore, the magnetic head of the head assembly connected to the head feeding mechanism at the fulcrum of the rotating shaft has an advantage that it can move substantially on a straight line within a minimum range.

  Also, a weight member such as a VCM member excluding the magnetic head and a fine adjustment position sensor member is provided at the other end of the carriage on the short stroke side of the head assembly. Therefore, it is only necessary to balance the weight of the head assembly with respect to the rotating shaft with the fixed weight on the long stroke magnetic head side, and there is an advantage that the increase in the total weight of the head assembly can be minimized.

  Therefore, the number of parts and the number of assembling steps can be reduced, and an increase in driving force of the VCM can be suppressed and high-speed response can be ensured.

  In addition, when a position sensor magnet is used as the position sensor member, the weight of the magnet is added to the VCM side, so there is no additional weight addition, and the position of this magnet is further away from the magnetic head, so the magnetism of the magnet is reduced. The adverse effect on the head is avoided, and the effect is expected to be further increased.

  A head assembly in which a magnetic head and its carriage are integrated is formed for the purpose of reducing the number of parts and assembly man-hours and ensuring high-speed response, and this head assembly is formed at the end opposite to the magnetic head. A permanent magnet and coil VCM and a fine adjustment position sensor member including a sensor magnet and a position sensor for driving the VCM are mounted, and the position movement of the magnetic head by the drive of the VCM is a rotational movement by the rotation shaft, and Realized by increasing the distance from the magnetic head to the fulcrum of the rotating shaft.

  The large distance from the magnetic head to the fulcrum of the rotary shaft reduces the tilt of the magnetic head in the direction perpendicular to the tape recording surface due to the movement of the magnetic head around the rotary shaft, that is, the position change due to the angle. Therefore, linear movement can be realized when the track interval of the magnetic tape is a minute distance. Also, by mounting the weight member of the position sensor, such as the sensor magnet, on the side opposite to the magnetic head, the weight on the magnetic head side is minimized from the rotating shaft that is the fulcrum, and the weight on the opposite side is balanced. The weight of the head assembly can be set to the lightest. Therefore, the position adjustment can be speeded up.

  An embodiment of the present invention will be described with reference to FIGS.

  3 is a perspective explanatory view showing an embodiment of a head actuator assembly according to the present invention, FIG. 4 is a plan explanatory view of FIG. 3, FIG. 5 is a front explanatory view of FIG. 3, and FIG. FIG. The drawings are illustrations, and the components of the portions not directly related to the present invention are not shown, and the shapes, relative dimensions, etc. are for reference.

  The head feed mechanism 70 shown in the figure has a function similar to that of the prior art due to the configuration of the lead screw 71, the head lift body 72, and the lead screw gear 73, and a carriage arm 83 that holds the magnetic head 81 is replaced with a rotary shaft having a bearing. The position of the magnetic head 81 is roughly adjusted by the rotation of the lead screw gear 73 which is fixed by 74 and driven by a step motor (not shown).

  As shown in the figure, the head assembly 80 is composed of a magnetic head 81, a head holder 82 that holds the magnetic head 81, and a carriage arm 83 that fixes the head to one end, and further includes a head feed composed of permanent magnets and coils. A VCM (voice coil motor) 84 for fine adjustment is provided at the other end of the carriage arm 83 on the side opposite to the magnetic head 81. The head assembly 80 finely moves the carriage arm 83 in the direction perpendicular to the magnetic tape track, that is, the axial direction of the lead screw 71, which is the width direction of the tape, by the current flowing through the coil constituting the VCM 84, thereby moving the position of the magnetic head 81. Make fine adjustments. Since the moving range by driving the VCM 84 is extremely narrow corresponding to the track width, a linear shape may be formed.

  In this case, in order to linearly move the magnetic head 81 in the tape width direction, the inclination of the tip portion of the head holder 82 that holds the magnetic head 81, that is, with respect to the tape recording surface as indicated by the broken line in FIG. In other words, it is sufficient that the head is not inclined in the vertical direction and the rotational range is a minimal range that is a linear motion. For this reason, it is necessary to make the distance between the magnetic head 81 and the rotation shaft 74 as a rotation stroke as long as possible. The illustrated rotating shaft 74 is located close to the coil constituting the VCM 84 at the end opposite to the magnetic head 81.

  With this structure, in order not to impair the high-speed response, the driving force of the VCM 84 may be reduced, so that the rotary shaft 74 is positioned at the center of gravity of the head assembly 80. That is, the rotating shaft 74 balances the weight of the side having the magnetic head 81 at the tip and the other end having the permanent magnet and coil VCM 84. Further, in the head assembly 80, since the weight of the carriage arm 83 on the side having the magnetic head 81 and the head holder 82 is determined, the weight on the opposite side is adjusted to the minimum weight so that the driving force of the VCM 84 can be reduced. It can be set.

  Due to such a configuration, the lead screw 71 of the head feed mechanism 70 is located in the middle between the magnetic head 81 and the rotary shaft 74 in FIG.

  The connection between the head feed mechanism 70 and the head assembly 80 is shown in a penetrating state as the rotation shaft 74, but the head lift body 72 is replaced with the rotation shaft 74 on the rotation axis of the rotation shaft 74. An uneven portion with the surface as a fulcrum can also be formed. That is, in the head actuator according to the present invention, the head feed mechanism and the head assembly are coupled by forming a fulcrum on a line perpendicular to the moving direction of the head feed mechanism, and the straight line formed by the fulcrum is the rotation axis. When rotating by driving the coil motor, the magnetic head has a fulcrum position and configuration that moves only within a limited range in which the magnetic head moves substantially linearly.

  The fine movement of the magnetic head is desired to be on a straight line perpendicular to the track of the tape. However, since the track of the tape is usually formed in parallel with a high density in the length direction, the movement of the magnetic head is the width of the tape. It may be perpendicular to the direction.

  Since such a configuration is adopted, the magnetic head of the head assembly connected to the head feed mechanism at the fulcrum of the rotary shaft can move on a substantially straight line within a small range, and thus the number of parts and assembly man-hours can be reduced. is there. Furthermore, since the carriage arm having a magnetic head at one end concentrates the necessary components other than holding the magnetic head at the other end, the rotating shaft can obtain a weight balance with the minimum weight, and thus high speed response. There is an effect that can be secured.

  The present invention is a carriage arm that finely adjusts the position of the head by VCM driving, and integrates from the magnetic head part to be positioned at one end to the VCM at the other end, and has a fulcrum that can rotate around the VCM at the other end. In addition, the other end is provided with necessary components other than the magnetic head holding mechanism to balance the weight. Therefore, the present invention can be applied when the object to be positioned by the VCM requires linear fine movement and its high speed response.

It is explanatory drawing which shows an example of the plane of the tape drive containing a magnetic tape head actuator assembly. FIG. 10 is an exploded perspective view showing an example of the overall components by disassembling a conventional head actuator assembly into a tape head assembly and a head feed mechanism. It is explanatory drawing which shows one Embodiment in the assembly perspective at the time of using VCM for a head feed mechanism with the head actuator assembly of this invention. (Example 1) It is explanatory drawing which shows the plane of FIG. It is explanatory drawing which shows the front of FIG. It is explanatory drawing which shows the side surface of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 70 Head feed mechanism 71 Lead screw 72 Head lift body 73 Lead screw gear 74 Rotating shaft 80 Head assembly 81 Magnetic head 82 Head holder 83 Carriage arm 84 VCM (voice coil motor)
85 Magnet for sensor 86 Position sensor

Claims (5)

  Used in high-capacity tape drives, the magnetic head (81) has a head feed mechanism (70) that moves linearly in the width direction of the tape for positioning, the magnetic head at one end, and a permanent magnet and coil at the other end. And a head assembly (80) each having a voice coil motor (84) for fine positioning in a direction across the tape track, wherein the head assembly has an integrated structure, and the head The feeding mechanism and the head assembly are connected by forming a fulcrum on a line orthogonal to the direction crossing the track of the tape, and the voice coil motor using the straight line formed by the fulcrum as the rotation axis (74). When moving by driving, the magnetic head moves only within a limited range of linear movement. A rotating shaft formed by the dots is provided at a position spaced apart from the magnetic head by a predetermined distance, and a position sensor member (85, 86) of the magnetic head for driving the voice coil motor is opposite to the magnetic head. A head actuator comprising a tip portion.   2. The head actuator according to claim 1, wherein a rotation shaft formed by the fulcrum is located in the vicinity of the permanent magnet and the coil provided at the other end.   2. The head actuator according to claim 1, wherein the rotation shaft formed by the fulcrum is positioned so as to balance the weights of both sides sandwiching the rotation shaft in the integrated head assembly. Actuator.   2. The head actuator according to claim 1, wherein the position sensor member includes a sensor magnet (85) for informing the position and a position sensor (86) for detecting the position from the magnet. Actuator. A tape drive on which the head actuator according to claim 1 is mounted.

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