JPS6025067A - Axial oscillation preventing mechanism for head carrier of recording and reproducing device - Google Patents

Abstract

PURPOSE:To energize a head carrier in the removal direction of a back crush to a screw shaft for driving the head carrier, i.e. axially, and improve the straight drive performance of a head by extending an offset spring spirally around part of the head carrier. CONSTITUTION:One terminal of the offset spring 34 as a tension coil spring is hooked with a spring peg pin 33 implanted in the magnetic head carrier 20, and the other terminal of this pring 34 is hooked with a spring peg part 4a provided to a main frame chassis 4. This spring 34 when extended between the spring peg pin 33 and spring peg 4a is would helically around the external wall of the cylinder part 20b of the magnetic head carrier 20, so a spring energizing force is applied to the cylinder part 20b and an angular moment around a guide shaft 26 is applied. Consequently, a radial deviating force for the magnetic head carrier 30 is generated ina radial direction to the guide shaft 26 to prevent the magnetic head carrier 20 from oscillating axially.

Description

Detailed Description of the Invention: Technical Field The present invention relates to a mechanism for preventing axial vibration of a head carrier of a recording/reproducing device, and particularly to a head carrier capable of feeding the head one track at a time for a disc-shaped recording medium. The present invention relates to a shaft vibration prevention mechanism.

A conventional magnetic sheet recorder rotates a magnetic disk and records information such as video signals or data using a magnetic head, or detects the recorded information using a magnetic head and displays it on a display device, or uses a printer, etc. It is used as a magnetic recording and reproducing device for recording.

In this type of magnetic recording/reproducing device, the recording density has increased as a result of improvements in the materials and mechanisms of the magnetic recording medium and magnetic head, and it is now possible to record and reproduce magnetic recording with a track width of several μm or less. As a result, the linear movement accuracy of the magnetic head is required to be on the order of micrometers.

In such a magnetic head that requires high straight-line accuracy, it is necessary to prevent the occurrence of axial runout of the magnetic head carrier on which the magnetic head is loaded as much as possible. The axial vibration prevention mechanisms of magnetic head carriers that have been proposed so far are as follows:
The disadvantage was that the configuration was complicated.

OBJECTS OF THE INVENTION The present invention eliminates the drawbacks of the prior art as described above, and has a simple structure that prevents the axial runout of the head carrier and improves the straight-line accuracy of the head carrier. The purpose is to provide a prevention mechanism.

Structure of the Invention The present invention provides a recording/reproducing apparatus that performs recording/reproduction on a disk-shaped recording medium by moving a recording or reproducing head in the radial direction along a guide axis. By winding the offset spring of the head carrier in a helical shape around the part, a moment force is generated in the backlash removal direction and around the guide shaft, and the head carrier is pressed in the radial direction with respect to the guide shaft. The present invention is characterized by a mechanism for preventing shaft runout of a head carrier in a recording/reproducing device, which generates a force to absorb radial play between the head carrier bearing portion and the guide shaft.

In the description of the embodiment of the axial vibration prevention mechanism of the head carrier of the present invention, a magnetic recording/reproducing device is described, but it is not limited to a magnetic type, and may be applied to an optical type or a capacitive type recording/reproducing device. The present invention is also applicable.

The disk-shaped recording medium includes magnetic, optical, and capacitance types.

Description of Examples (Figures 1 to 9) In the following, the present invention will be explained in detail.

FIG. 1(a) shows a plan view of the cassette, and FIG. 1(tb'+) shows its sectional view. In Figure 1 (at), 1 is a magnetic disk, 2 is a cassette formed into a flat box-shaped body made of resin, etc., and the magnetic disk 1 is inside this cassette 2.
is stored. A hub 3 is fixed to the center of the magnetic disk 1, and a spindle 8 coaxially attached to the shaft of a disk motor 7 shown in FIG. 4, which will be described later, is inserted into a center hole 3a provided in the hub 3. . Therefore, the magnetic disk 1 and the hub 3 are rotated as one unit by the rotational drive of the disk motor 7.

A counter 40 is rotatably supported by a part of the housing of the cassette 2 and is locked by a click mechanism (not shown), which indicates how many recording tracks remain that can be recorded on the recording tracks of the magnetic disk 1. This indicates the number of recorded tracks. 4
0a is a hole into which a slider 45 shown in FIGS. 7 and 8, which will be described later, is inserted to drive the counter 40 in steps;
This is a key groove into which a key 45b shown in Figure I-7, which will be described later, is inserted into the '0bid counter hole 40a, and also functions as a pointer to indicate the number of recorded tracks on the magnetic disk 1. For example, assuming that the maximum number of recordable tracks on the magnetic disk 1 is 50, the counter 40 has a click mechanism (not shown) having 50 or more click positions within a range of 360 degrees or less, and the first If the track is the outermost track and the 50th track is the innermost track, the amount of movement to the position of each recording track of the magnetic head carrier 20 holding the magnetic head 6 shown in FIG. In response to this, the counter 40 is given step drive and the number of recorded tracks can be read from the counter 40.

In FIG. 1(b), the cassette 2 includes a magnetic head 6.
Openings 2a, 2b are provided on the opposing faces of and on the opposite curve, these openings 2B.

It covers the magnetic disk 1 except for 2b. The cassette 2 containing the magnetic disk 1 is mounted by a support mechanism (not shown) so that the magnetic surface of the magnetic disk 1 and the magnetic head 6 face each other through the opening 2a. The magnetic disk 1 is rotated at an integral multiple of the field frequency of a standard TV signal by a disk motor 7 shown in FIG.
A still image is recorded by sequentially forming a signal as an annular track for an integral number of fields. In an embodiment of the invention, the standard I@TV signal 1d, for example,
NTSC system, therefore field frequency is 60H2
The number of rotations of the magnetic disk is 360 (1 rpm), and one field is recorded on one track.

FIG. 2 shows a plan view of the magnetic disk drive (σ) seen from the direction opposite to the loading direction of the cassette 2, where 4 is a main body chassis, 5 is a stepping motor that drives the magnetic head 6, is indicated by a two-dot chain line.

FIG. 3(a) shows a perspective view of the magnetic disk device shown in FIG. 2, viewed from the back side. In the figure, 4 is a main body saw, 5 is a stepping motor, and 7 is a disc motor. Reference numeral 20 denotes a magnetic head carrier that supports the electro-mechanical transducer 11 to which the magnetic head 6 shown in FIG. A guide shaft 26 is fitted into the portion 20b and is supported slidably in the axial direction. Both ends of the guide shaft 26 are pressed and fixed to a shaft fixing portion 28 integrally molded with the main body chassis 4 by shaft fixing plate springs 27 .

Reference numeral 25 denotes a clamper shown in detail in FIG. 5, which will be described later, which fixes and holds the retaining pin 23 that engages with the screw shaft 29 with respect to the magnetic head carrier 2o.

Then, the rotation of the screw shaft 29 is applied to the magnetic head carrier 2o via the locking pin 23, and one end of the biasing spring, which is a magnetic rod, is attached to the spring hook pin 33, and the other end is attached to the spring hook pin 33 as shown in FIG. 6, which will be described later. It is stretched around the spring hanging part 4a shown, is helically wound around the cylindrical part 20b of the magnetic gear rear 2°, and a spring biasing force shown by arrow C is applied. A rectangular plate spring 35 is fixed to the end of the arm 2oc of the magnetic head carrier 20 with a screw 36. This leaf spring 3
Both ends of the guide shaft 38 that come into contact with the shaft fixing leaf spring 3
7, the shaft fixing part 3 integrally molded with the main body chassis 4
It is suppressed and fixed by 7'. The leaf spring 35 rotates the magnetic gear rear 20 in the clockwise direction or counterclockwise around the kite shaft 26 by adjusting the adjustment lever 39 shown in FIG. 6, which will be described later. Adjustments can be made such that the magnetic head (not shown) supported by the magnetic head 20c is displaced in the direction of protrusion or retraction with respect to the magnetic disk. 32 is a flexible shaft joint, and the screw shaft 29 is a bearing 3.
The bearing 31 is fixed to the main body chassis 4 by the fixing leaf spring 3.

58 is a drive gap stun, screw 1IilII2
9 is fixed to one end with a set screw 59.

6 (i is a wire, one end'(f li+A It
The force cambus stan 58 is attached to the other end as shown in FIG.
, y:4<i! shown in Figure 8. jlJ')-Reel 4: (Fixed in the grooves 4:3a, respectively, and wound only the required amount. Drive reel 4; another τi4);
A spring hook 61 is installed in B43b with tongue 1, and this spring hook 61
A counter spring 62 is mounted between the drive reel 43 and a spring hook 63 implanted in the main body chassis 4 via the m fall 43 b of the drive reel 43 . This counter buy, 62, is
The purpose of this device is to apply rotational force to the driving reel 43 in the direction opposite to the rotational direction of the wire 60.The stepping motor 50 rotates step by step through the flexible shaft joint 32 and the screw r.
The drive cap stan 58 is rotated via d29, the wire 6o is wound in, the FtE dynamic reel 43 is fed, and the counter 4o is given incremental rotation. The rotation of the screw shaft 29 is applied to the engagement pin 23 that meshes with the screw shaft 29, and the rotation of the screw shaft 29 is applied to the engagement pin 23 that meshes with the screw shaft 29, and the axial direction feed is given to the magnetic head carrier 20 step by step.
The total radial feed can be given. 51 is a solenoid fixed to the main body 7 year 74, 52 is integrally attached to the lever 5:3 with its iron core, and one end of the lever 53 is rotatably connected to a bell crank 55 by a shaft 54. There is. The shaft 56 is the center of rotation of the bell crank 55. The protrusion 55a of the bell crank 55 is connected to the arm 47a of the clutch lever 47 shown in FIG. 8, which will be described later.
A bottle 49 is provided at one end of the lever 47. When the solenoid 51 is energized and the iron core 52 is sucked, the lever 53 is sucked in the direction of the arrow, and the bell crank 55 is rotated clockwise 1c around the entire center of the shaft 56.
Pushing down the tip 47a of the clutch lever 47 (f
(As shown in FIG. 3(a), the bin 49 is moved upward relative to the main body 4, the drive reel 43 is moved upward, and the counter 40 is moved upward as shown in FIGS. 7 and 8, which will be described later). When fully engaged, the counter 40 does not allow the stepping motor 50 to rotate in steps 4 and half.In addition, in this state, [clutch lever 4'7 -i'ifa 47a causes iiJ movement))2 The piece 0 and the fixed bridge )) 50'' come into contact.

In the figure (a) explained above, the stepping motor! When coaxially arranging J and Scri" ll1II 29 (・Tips) (Explained in Section 8, Akira (7)
It is also possible to rotate the main body chassis 4 in the direction perpendicular to the screw shaft 29 as shown in Figure 3 (bl).
↑≦BVC, the stepping motor 5 is fixed so as to be perpendicular to the Moru axis 29.1.
Ru.

301 is a 1ljJ rotating shaft of a stepping motor, a worm gear 302 is attached to the tip thereof, and it engages with a worm wheel 303 attached to one end of the screw ill+29. 31ff Use the same fixing leaf spring as shown in Fig. 3(a) to attach the bearing (4) of the screw shaft 29.
↓Figure 3 (al 30) is 1 to main body/yarn 4?・] Set. According to this configuration, a rotational torque in the direction of the arrow is applied to the screw φ29 via the wire 6o and the drive campstuff 58 (2) by the return spring 62 to the drive reel 43 in FIG. 3(a). , the backlash between the worm gear 3+J2 and the worm wheel 303 can be eliminated, and the magnetic head 6 can be moved with high accuracy.

Figure 4 shows a 1111 cross section 1r11 of the Izoku disk device shown in Figure 2 viewed from cross section A-A. be. A disk motor 7 is inserted into the center hole 3a of the magnetic disk 1 (which is integrally provided at the center of the magnetic disk 1).
The spindle 8 fixed to one of the lungs is inserted. ...A ring-shaped suction plate 9 made of a soft magnetic material such as iron (11) is attached to the bottom of the holder 3, and is firmly attached to the groove of the suction plate 9 and the spindle 8. Due to the attractive force of the link magnet 102, the height reference surface 3b of the hub 3 is brought into contact with the reference surface 8B (f) of the spindle 80.
] - The spindle 3 and the spindle 8 are driven by the disk motor 7 and rotated as one body. The magnetic head 6 is attached to one end of the magnetic head 2 as shown in FIG. 5, which will be described later.]
This is a bimorph support FF15 material that supports a mechanical mechanical replacement rope 1 (hereinafter simply referred to as biself) at its fixed end, which is made up of a pair of rectangular plate-shaped H double bodies. The bimorph support member 12 is provided with two holes 12e and 12f.
ing. Reference numeral 14 denotes an approximately L-shaped mounting member to which the bimorph support part 12 is attached;
4 includes a positioning conical pin 15 and an adjustment turning screw (screw 16).
is provided. 1. The conical bottle 15 is the mounting member 14.
The adjusting conical screw 16 is movable forward and backward so that the biting of the screw can be adjusted by screw connection. Since the positioning holes 12e and 12f of the bimorph support member 12 engage with the slope of the conical end of each of the positioning conical screws 15 and 1ilJd, the conical screws 15 can be set as the pivot point by adjusting the conical screws 16. , the position of the recording head 6 can be adjusted in a direction perpendicular to the recording track.

In addition to the positioning circle φ'W pin 15 and adjustment conical screw 16 provided in the L-shaped mounting member 14 described above, two positioning holes 1.4a are provided. The conical slopes of two conical positioning pins 21 are engaged with the positioning holes 14a. 24 is a pressure spring; 23
The mounting member 14 can be pivotally supported on the magnetic head carrier 20 by the setscrew and the 74 setting screw 22, so that the mounting member 14 can be adjusted in position. FIG.
Regarding the bimorph head carrier 20, the bimorph support member 12 shown in FIG. 5(1)) and the bimorph support member 12 shown in FIG. 5(c) VC
Showing 1. This will be explained with reference to a side sectional view of the magnetic head 6f, which is fixed at the free end of the bimorph 11. This is used as a last resort to correct the track deviation of the head 6 during reproduction of a magnetic disk. As shown in FIG. 5(b), the bimorph 11 has a U-shaped hole on the side opposite to the side supporting the head 6.
a is truncated by t'i*. 12 is bimorph support fj
1S 44, as shown in FIG. 5(C), a part of the bimorph support member 12 has a width that is much wider than that of the bimorph 11. A bottom portion 12a is provided. 1ili1 of one of the parts that sandwich this 211 part 12a
One side has a screw hole 1.2b, and the other side has a screw hole 12b.
The hole 12c, which is much larger than the diameter of (llt'I), has the same IQ
The CS is marked on II. tR of the bimorph support member 12 so that the center of the U-shaped notch 11a of the bimorph 11 almost coincides with the centers of the screw holes 12b and the holes 12c.
12a, as shown in FIG.
3, by deforming the protrusion 12d of the bimorph support member 2 toward the screw hole 12b,
One end of the bimorph 11 is supported by Cla/Zo. The mounting member 14 to which the bimorph support member 12 is mounted is formed in an L-shape, and the two positions (I-marking holes 12e, 1.2f shown in FIG. 4) provided on the bimorph support member 12 are Positioning conical pin 15 and adjusting conical screw 1
6 is arranged, the positioning conical pin 15 is fixed to the mounting member J4, the adjusting conical screw 16 is screwed together, and the M adjustment circle θ)11. The screw 1G can be moved forward or backward by adjusting the screw. The bimorph support member 12 is attached to the bimorph support member 12 by attaching the mounting screws 17 and 18 as shown in FIG. is attached to the attachment member 14. At this time, the mounting screw 17 is biased i-1 by the pressing spring 19 to push the unimorph support portion 12 toward the rear member 14 . Therefore, the azimuth adjustment screw 18
If you also refer to 14r, 4 j*, l, you can see that the positioning circle (1) pin J5 and 1ii71 adjustment circle (1
1 Screw 16, its tip>'f6f circle (j mouth'rl
In order to engage the positioning holes 12e and 12fvc of the support member 12, the fifth
1 Azimuth adjustment screw 1 is biased by turning VC in the direction of arrow A shown in [1a] and screwed to the mounting part 14.
The MlIIIl is stopped 1114 by the collar portion of No.8.

Therefore, azimuth i! :4”1 screw l 8 <r m
By making one turn, arrow A shown in Figure 21 5 (a)
The deflection of the direction, that is, the azimuth + i'il Q, the fine adjustment of the direction ゛1;
Rotate the adjusting screw 16 by +1.
From 2, 1r! Using the f-determining conical pin 15 as a pivot point, the magnetic head 6 can be tilted 1lij, 411k in the direction of the arrow, that is, in the direction orthogonal to the recording track of the magnetic head 6 tray.

Furthermore, as shown in FIG.
a are provided, and corresponding to these positioning holes 14a,
The mounting member 14 is cut 8 (Y).
1F bottle 21 is planted, positioning hole 1 of mounting part @14
4a [m stroke circle (ml bottle 210 circular conical surface engages,
As shown in FIG. 6, which will be described later, I:t?
Place it on the head carrier 20. And as mentioned above/
This azimuth adjustment and the same 41 (i K, depending on the force of the pressing spring 24, the interrogation part 14 is determined by the 11th position and the Tagawa bin 21
As shown in FIG. 6, the pivot point is taken as the pivot point, and the rotation is prevented by the flange of the screw 22. Therefore, 1□:4'1□1! - Adjustment in the direction of arrow A in Figure 6 by rotating the screw 22, 1-1)
The position of the magnetic head 6 can be adjusted in the direction of the recording track using the pin 21 as a pivot point.

The above (adjustment of the d air head is summarized as A and CI') 1iJl$ 7'/22 (7) Q'
t fiLN Adjustment, mounting member 14rL IDI
Ii Neu/Thick circle,] 1 Bin 21 is the pivot point 7
．． 11μ head 6, 21L lj4 disk 1 track direction)...st, 17! IJli",,
(2) As shown in Fig. 454 and Fig. 6 1/C, Ij2 + of the adjustment member 14 is fitted into the mounting member 14;
``Due to the 4th adjustment, the inquiry tg1+ 4/114 VC:,
ii'keit tai lid iD meen yli hi"
Considering the optical pivot point 15 and 17 in the direction perpendicular to the magnetic track 1, it is possible to give an angle of 11°4.

(20; 155 As shown in Figure (a), the magnetic head 6
Bimorph support member 1 that supports bimorph 11 together with
C) Adjustment of azimuth adjustment screw 18 provided in 2 C)
- From frl- positioning conical pin 15 and adjustment t, G circle ζ
C) Positioning holes 12e and 12f provided in the bimorph support portion 12 that the screw 16 engages with are used as pivot points. 1! It is possible to make fine adjustments in the direction of the arrow shown in FIG. 5(a), that is, in the azimuth direction.

In order to perform each of the above-mentioned adjustments well, the circular button, pin 15 and adjustment screw 16 must be aligned vertically to the magnetic head 6 in FIG. The mounting screw 17 and the tensioning screw 18 are aligned on a horizontal line in FIG. [7
Similarly, the two circular buttons and pins 21 are perpendicular to the above-mentioned perpendicular line, and the mounting members 140, conical bottle 15 and Hl,
Although it is best to position it on a line perpendicular to the plane on which the .31 tension screw 16 is disposed, it is of course not limited to this.

Next, the configuration and operation of the magnetic head carrier 20 will be described. As shown in FIG. The sintered bearings 22 are press-fitted from both ends of the cylindrical portion 20b in the same axial direction. A protrusion 20d is provided at two positions on the side surface of the cylindrical part 20b, and a third
As explained in Figure (a), a groove 20e that is slightly wider than the engagement pin 23 that engages with the screw shaft 29 is formed in each protrusion 20d according to the advance angle of the screw shaft 29.
The sintered bearing 22 is inclined at a predetermined angle with respect to the axis of the sintered bearing 22 of 2 uA.

25 is a clamper, the shape of which is approximately U-shaped;
Two transition parts 25a are provided, and two protrusions 25b are formed to face each other on the U-shaped inner wall part. A tapped hole 25d is provided approximately at the center of the arm portion 25c of the clamper 25, which is connected to the U-shaped dog portion. Clamper engagement holes 20f are provided at vertically symmetrical positions in the cylindrical portion 20b.

The bending inner width of the U-shaped portion of the clamper 25 is set to be approximately equal to the outer diameter of the cylindrical portion 20b, and the U-shaped portion of the clamper 25 is slightly expanded against the elasticity of the clamper 25.
The two protrusions 25b provided on the inner wall of the U-shaped portion are pushed in until they are inserted into the clamper coupling hole 20f provided on the lower surface of the cylindrical portion 20b. When the protrusion 25b is inserted into the clamper engagement hole 20f, it returns to its original shape due to the elastic force of the clamper 25, and the clamper 25 rotates freely around the clamper engagement hole 20f due to the limp movement of the magnetic head carrier 20. Supported by

Next, by attaching the engagement pin 23 to the groove 20e and inserting the clamp screw 25f into the tap hole 25d of the clamper 25 and tightening it, the tip of the clamp screw 25f presses against the side surface of the cylindrical portion 20b. Due to the generated reaction force, the clamper 25 is rotated counterclockwise around the clamper engagement hole 20f, so that the engagement pin 23 is rotated at the sloped portion of the chest 25a of the clamper 25, as shown in more detail in FIG. By pressing against the surface perpendicular to the groove portion 20e, the engagement pin 23 is fixedly supported with respect to the cylindrical portion 20bK.

In this case, by pressing the retaining pin 23, the reaction force received by the fishing portion 25a is received in the direction of the plate surface of the clamper 25, so the stiffness is higher than that of the clamper 25 in the direction of the plate surface. The deformation is small and due to elastic deformation in the thickness direction of the arm portion 25c of the clamper 25, the engagement pin 231'? : It is possible to generate a pressing force and hold the retaining pin 23. The reaction force of the clamper 25's pressure on the engagement pin 23 is received in the surface direction of the plate material, resulting in high rigidity and little deformation, and the clamping pressure is received by elastic deformation in the bending direction in the gap. In addition to the advantage that it is easy to perform pressure treatment, the guide @
There is an advantage that the engagement points between the engagement pin 23 and the two screw shafts can be set near the point 26.

FIG. 6 is a side sectional view of the magnetic disk device of FIG. In FIG. 6, 1 is a magnetic disk, 2 is a cassette, 4 is a main body chassis, and 6 is a magnetic head. One end of a biasing spring 34, which is a tension coil spring, is attached to a spring hook 33 installed in the magnetic head carrier 20, and the other end of this spring 34 is attached to the main body chassis 4. It is latched onto the spring hook 4a. When this spring 34 is stretched between the spring hook pin 33 and the spring hook 4a, the magnetic head carrier 200 cylindrical portion 20
Because it is wrapped helically around the cylindrical outer wall of b,
As shown in the figure, a spring biasing force shown in the direction of arrow O is applied to the cylindrical part 20b, and a rotational moment about the guide shaft 26 is applied in the direction shown by arrow O in FIG. This generates a radial bias force on the magnetic head carrier 2o with respect to the guide shaft 26 at the abdomen of the spring 34, thereby providing an effect of preventing the magnetic head carrier 20 from collapsing. Note that although there is a radial gap of approximately several μm between the guide shafts 26 and 38, this gap can be absorbed by the biasing force described above.

A rectangular plate spring 35 is fixed to the arm portion 20c of the magnetic head carrier 20 with a screw 36. The leaf spring 35 has 37 protrusions made of a high-friction material. This protrusion 37 is in contact with a guide shaft 38 fixed to the main body chassis 4 with a rotational moment, in the same way that the guide shaft 26 is given a rotational moment in the direction of arrow C. The biasing force of the magnetic head carrier 1)a 20 in the direction shown by the arrow C generated by the biasing force 34 is
It is possible to eliminate the knock lash at the engagement portion between the retaining pin 23 and the screw shaft 29 shown in FIGS.

In short, the magnetic head carrier 20 is a guide.

11] The sliding direction can be determined at once by 26,
Further, the rotation of the guide shaft 26 around the guide shaft 26 is restricted by the guide shaft 38.

A screw hole into which the adjustment screw 39 is inserted is provided in the attachment part of the plate spring 35 ffff attached to the arm part 20c of the magnetic head carrier 20, and the adjustment screw 39 is inserted in the direction in which the adjustment screw 39 moves against the elastic force of the plate spring 35. When the adjustment screw 39 is tightened, the leaf spring 35 is deformed downward relative to the magnetic head carrier 20.

The magnetic head carrier 20 rotates clockwise about the guide shaft 26 in response to a reaction force due to its deformation. As a result, the magnetic head 6 moves in the direction of the magnetic disk 1, that is, in the protruding direction. When the adjustment screw 39 is loosened, the magnetic head 6 moves rearward with respect to the magnetic disk 1, that is, in the retracting direction.

That is, by adjusting the adjustment screw 39, the position of the magnetic head 6 can be adjusted in the direction of protrusion or retraction with respect to the magnetic disk 1. In this case, the guide shaft 26. However, the actual magnetic head protrusion adjustment amount is around 20 μm, and the arm 2 of the magnetic head carrier 20 is subject to rotational torque.
Since the distance a, which is the length of 0c, is around 2 Q mH, the angle of inclination is less than a few minutes, which is virtually no problem.

7 and 8 are the O-0 cross section of the magnetic disk device shown in FIG. 2, the side sectional view of the counter seen from D, and 1jj1
A first view is shown.

In FIG. 7, 41 is a shaft implanted and fixed to a counter shaft 42 integrally attached to the main body chassis 4,
A driving reel 43 is rotatably supported around the shaft 41, and a locking ring 44 attached to the Itab 41 prevents the shaft 41 from sliding in the thrust direction. A slider 45 is rotated by the rotation of the drive reel 43, and is supported slidably in the thrust direction of 1141 by the vertical movement of a bin 49 shown in FIG. 8, which will be described later. The slider 45 is provided with a protrusion 45c that protrudes in the direction of the 1st movement reel 43'7j, and is fitted into a retaining hole (not shown) provided in the i% shield creel 43 so as to be slidable in the thrust direction. Ha drive +1
tl+ 'J- Rotates together with the rotation of the wheel 43.

The slider 45 has a bin 49 shown in FIG.
The key 45b is inserted into and fitted into the keyway 401 of the counter 40 shown in FIG. 1(a). A cap 46 is press-fitted into @141 as a stopper for the slider 45 in the thrust direction.

In FIG. 8, a clutch lever 47 is rotatably supported on a lever shaft 48 fixed to the main body chassis 4 shown in FIG.

Note that the clutch lever 47 (/ζ is provided with a spring 48', and a rotational moment shown in the arrow direction A is applied to the clutch lever 47. A pin 49 is installed at the other end of the clutch lever 47. , this pin 49 fits into the groove 45a of the slider 45.The clutch lever 47 has an arm Ffl 47 on the side opposite to the side where the pin 49 is installed.
It is equipped with a. To explain with reference to FIG. 3(a), 51 is a solenoid, 52 is an iron core of the solenoid 51,
53 is a lever that connects the iron core 52 and the bell crank 55. A shaft 54 rotatably supports the lever 53 on a bell crank 55. 56 is 111I, which fixes the center of rotation of the bell crank 55 relatively to the main body chassis 4. The clutch lever 47 rotates clockwise around the shaft 48, and! 17+: When the counterclockwise G is rotated 11b in the 1,000 direction, the arm portion 47ai! (From the slider 451d, the key groove of the counter 40', ('+ l)
3 is removed from (, (1 person or I+i).

Raw: (1 sol) (a) As seen in the VC, the protrusion 5521 of the bell crank 55 is the hl of the clutch lever 47.
Wf+ 47a has 1 concubine and h・su, friend 2 noid 51
When is excited, the iron core 52 is attracted in the direction of the arrow, and the lever 53 also moves in the same direction to 4t, thereby rotating the libercrank 55'ti BSM (direction. From the rotation Vζ of the bellcrank 55 , the bell crank protrusion 55a presses the clutch lever 47, and the Clara chin bar 47 shown in FIG. VC1, Al, move the slider 45 in the direction of counter 40K:("+L retreat i((). In this state,
Since the key 45b is detached from the keyway 40b of the collar 40 even after turning D'' four times, the rotation of the slider 45 is not transmitted to the counter 40 and the counter 40 is transferred to the magnetic disk 1. This can hold an indication of the number of recorded tracks.C, section 50 and fixed section 50.
' are in contact with each other to form an electrically conductive track, thereby providing a write inhibit mode to a circuit device of a magnetic recording/reproducing apparatus (not shown). Note that 57 is made of an insulating material, and the sections 50 and 5
If the 0 solenoid 51 connecting 0' is in a non-energized state, the clutch lever 47 is spring biased in the direction of the arrow in FIG. 8 due to the elastic force of the spring 48'. When the phases of the keyway 40b of the counter 40 on the cassette 2 side and the key 45b of the slider 45 match, the slider 45 is raised and the key 45b is inserted into the keyway 40b. As a result, the section 50 and the fixed section 50' are separated, and the electrical conduction 4 is cut off.

Therefore, when you remove a cassette containing a partially recorded magnetic disk and then load the cassette to continue recording, the counter 40 provided on the cassette retains the value of the maximum number of recorded tracks. Therefore, the value of the maximum number of recorded recording tracks described above is calculated by dividing the value of the maximum number of recorded recording tracks into the section 50 and the fixed IJJ section 50' generated by inserting the key 45b into the keyway 40b.
It can be detected from the opening of a switch consisting of

Therefore, since continuation of recording can be started from the trunk immediately following the largest recorded track, overwriting of recorded tracks is prevented.

During playback, it is common for all recorded trunks to be randomly accessed in one sequence, so in such a case, the keys 45b of the slider 45 and the keys +
When the key 45b is inserted into the key 40b at the time when the phase matches with the 71140b, the rotation of the slider 45 is applied to the counter 40, and the magnetic recording that was performed before reproduction is performed. There is a risk that the counter 40, which indicates the maximum number of recorded tracks on the magnetic disk 1, will be incremented, and the value of the maximum number of recorded tracks recorded on the magnetic disk 1 will become unknown.

Therefore, during reproduction, by energizing the solenoid 51 and retracting the key 45b of the slider 45 from the keyway 40b of the counter 4°, the rotation of the slider 45 will not be applied to the counter 4o. Therefore, the counter 4o can hold the value of the maximum number of tracks recorded on the magnetic disk 1.

Next, the driving of the counter 40 and the adjustment of the track designated position of the magnetic head and the counter 4o on the recording track will be explained with reference to FIGS. 3 and 8.

In FIG. 3(a), the drive cap stan 58 is fixed to one end of the screw shaft 29 with a set screw 59,
It is configured to rotate together with the screw shaft 29.

The end of the wire 60 wound around the cap stan 58 is fixed to the groove 43a of the reel 43 shown in FIG. 8, and is wound by the required amount. Other groove portion 43b of drive reel 43
A spring [61 is installed in the spring hook 61, and a counter spring 62 is mounted on the spring hook 61 so as to be wound around the groove 43b of the slider 43, and the other end of the counter spring 62 is installed in the main body chassis 4. The hook is stopped on the spring hook 63.

Therefore, the driving reel 43 is biased clockwise by the counter spring 62, and the wire 60 is stretched against this biasing force.

Here, if the respective diameters of the driving cap stun 58 and the driving reel 43 are appropriately selected, the rotation angle of the tipping motor 5, that is, the rotation angle of the magnetic head 6 corresponds to a predetermined angle of the counter click mechanism (not shown). The counter 40 can be driven in one-to-one correspondence with the truck feed.

Further, the position of the magnetic head 6 of the first recording track on the magnetic disk 1 and the instruction position of the counter 40 indicating the first recording track are adjusted by the rotation of the stepping motor 5. Position the magnetic head 6 on the 1st recording track, then loosen the set screw 59 in this state and rotate the drive cap stand 58 with respect to the screw shaft 29 to rotate the drive reel 43 to 1.
The phase of the counter can be adjusted by adjusting the key 45b of the slider 45 so that the counter 40 accurately indicates the value of the first recording track. When the head 6 is reset, it is fed one step at a time until it is reset to a predetermined reference position, for example, a position shifted outward by one track pitch from the first recording track of the magnetic disk 1, and then the head is reset to the reference position. In the normal recording or reproducing operation described later, a control system configured to transfer one track pitch in four steps and a circuit for activating or inactivating the counter 40 are shown.

In the figure, 101 is a recording switch, 102 is a playback switch, and 103 is a mode setting circuit. In response to each operation of the switches 101 and 102, the mode setting circuit 103 sets only the output RC to a high level in the recording mode and only the output RP in the playback mode, and these outputs are used for controlling the recording operation. The AND gate 104 and the AND gate 109 for controlling the reproduction operation are connected to the comparison circuit 114, which will be described later.
−A=B is given along with the enable signal that occurs when the J output goes high, and is further connected to the AND gate 104.
The contact piece 50 and the contact piece 50' shown in FIG.
When is open, a high level signal is applied to control the recording signal processing circuit 130 and the reproduction signal processing circuit 131, respectively. Note that r is resistance.

A track designation switch 105 is used to designate a desired track, and is configured by, for example, a numeric keypad. 106 is a register that stores data n related to the track address designated by the track designation switch 105; 107 is a register that stores data n regarding the designated track address stored in the register 106, the setting mode (recording or playback) of the device, and the recording prohibited state in the recording mode. It is a display device that is used only for display purposes. For this purpose, in addition to the output of the register 106, this display device 107 is provided with the output of an inverter 122 that inverts the outputs Re and RP of the mode setting circuit 103 and the output of the AND gate 104. 107 is preferably a small display such as a liquid crystal, electrochromic or light emitting diode. 108 is a data conversion table, such as a ROM, which outputs 4n in this example as head position setting data. Here 4n is designated switch 10
5 (converted to digital data using a binary code, for example), one track pitch corresponds to a head movement of 4 steps by the head movement stepping motor 5 (Fig. 3). This is numerical recording head position setting data.

113 is an up/down counter (hereinafter abbreviated as U/D counter) that detects the position of movement of the magnetic head 6 by the stepping motor 5; 0.114 is a comparison circuit that compares the output of the data conversion table 108 (referred to as A) and the output of the U/D counter 113 (referred to as B), and it compares "A>B","A-
115 is a pulse generator, and the stepping motor 5 is driven based on the output pulse for stepping.Hereinafter, the stepping motor 5 is driven based on the stepping pulse 1. The following description assumes that one step is sent per pulse. Reference numeral 116 denotes a control circuit that controls the operation of the motor 5- based on the outputs of the comparison circuit 114 and the pulse generator 115. For example, during the output of the comparison circuit 114, The motor 5 rotates forward in response to a high level of "A>B", the motor 5 rotates in the reverse direction in response to a high level of "A<B", and the drive circuit rotates in response to a high level of "A=B". The control circuit 116 has a function of stopping the motor 5 by cutting off the supply of pulses to the motor 117.The control circuit 116 outputs a rotation direction designation signal that designates forward or reverse rotation of the motor 5, and a pulse for H-rotation drive. For example, when this signal is at a high level, the rotation direction designation signal indicates forward rotation,
Commands reverse rotation when the level is low. 117 is the control circuit 11
A motor drive circuit 118 rotates the motor 5 by a specified amount in a specified direction based on the output of the comparator circuit 114 and a reset circuit 127 to be described later.
The output is connected to the reversing input of the control circuit 116.

Here, it is assumed that the magnetic head 6 moves in the direction in which the track address increases when the motor 5 is rotated in the normal direction, and in the direction in which it decreases when the motor 5 rotates in the reverse direction.

The rotation direction designation signal and pulse output from the control circuit 116 are given to the U/D counter 113 as a count mode setting signal and a count pulse, respectively. In this case, the U/D counter 113 is set to the high level of the above-mentioned rotation direction designation signal, that is, the forward rotation command is set to the rear run count mode, and the low level of the above rotation direction designation signal, that is, the reverse rotation command is set to the backward run count mode. Ru.

Reference numeral 119 denotes a 7-lip flop of the "A<B" output of the comparator circuit 114, and 12o an OR game which receives the Q output of this flip-flop 119, the output RC of the mode setting circuit 1o3', and the output of the reset circuit 127). 12
1 in response to the output of the OR gate 120, the third (a), s
This is a solenoid drive circuit that excites the solenoid 51 shown in the figure.

133 is a recording start (trigger) switch; 134 is an AND gate that receives the output of the recording start switch 133 and the output of the AND gate 134; the output is sent to the recording signal processing circuit 1;
30 as a control signal.

124 is a power supply; 125 is a power switch, which is turned on when the A1 power switch 125 is turned on; a pulse generator 115; a control circuit 116; a drive circuit 117;
0, flip-flop 119, solenoid drive circuit 12
1. Reference position detection device 12 for the stepping motor 5 and the magnetic head 6 (generally a transducer)
6 and a reset circuit 127 are connected to the power supply 124.

Note that the disk motor (7 in FIG. 3(a) and 4.6) can also be connected to the power source 124 together with this. When the magnetic head 6 is sent toward the reference position and the reference position is detected, the reference position detection device 126 generates a reference position detection completion signal, which is sent to the reset circuit 127 . The reset circuit 127 is connected to a magnetic disk (1 in FIG.
A reset signal for moving the magnetic head 6 to the reference position outside the first track of ) is continued to be supplied to the control circuit 116 via the ORG 118 until the reference position is detected. In response to this reset signal, the control circuit 116 outputs a rotation direction designation signal and pulses for rotating the motor 5 in the reverse direction until the reset signal is released.

When the magnetic head 6 is reset to the reference position and the reset signal of the reset circuit 127 is released, the output of the inverter 127' becomes high level, which closes the switch circuit 128, and the switch 125 is turned on to turn on the power. 124. At the same time, the power-up clear circuit 129 operates, and a power-up clear pulse (PUC) is applied to the mode setting circuit 104, register 106, U/D counter 113, etc., and these circuits are cleared or reset.

130 is a recording signal processing circuit for supplying a video signal to the magnetic head 6 and recording it on the magnetic disk 1; 131 is a reproduction signal processing circuit for reproducing the signal picked up by the magnetic head 6; As described above, they are controlled by respective AND gates 121 and 122. Reference numeral 132 indicates a display device for displaying the reproduced signal, but the reproduced signal can also be connected to an output device such as a printer.

When the power switch 125 is turned on, the pulse generator 119,
Solenoid drive circuit 11#, reference position detection device 126,
The reset circuit 127, the stepping motor 5, and if necessary the disk motor 7 are connected to the power supply 124, and the reset circuit 127 applies the reset signal to the OR gate 118 until the magnetic head 6 reaches the reference position.
is supplied to the control circuit 116 via.

Accordingly, the control circuit 116 sets the rotation direction designation signal to a low level and instructs the drive circuit 117 to rotate the motor 5 in reverse, and at the same time outputs a pulse from the pulse generator 115 for stepping the motor. As a result, the drive circuit 117
Reverse 1. When the magnetic head 6 is not at the reference position,
It is moved until it reaches the reference position. Oh, the other day,
The reset signal from the reset circuit 127 causes the output of the OR gate 120 to go high, so the solenoid drive circuit 121 operates and excites the solenoid 51. Therefore, the slider 45 moves its key 45b from the counter 4° on the cassette 2 side. He would end up idling in a state where he was forced to leave.

Then, when the magnetic head 6 reaches the reference position, the reference position detection device 126 detects this and its output drops to a low level, so the reset circuit 127 stops supplying the reset signal to the control circuit 116, and the motor 5 will also stop at that position. Additionally, since the output of the Geo Age 120 becomes low level, the solenoid drive circuit 121 de-energizes the solenoid 51, and the slider 45 is biased by the clutch lever 47 in the direction of engaging the slide counter 40. The state will be as follows. However, in this state, slider 4
5 is out of phase with the keyway 40b of the counter 40, so the engagement between the two has not yet taken place. When the reset signal from the reset circuit 127 becomes low level, the output of the inverter 127' becomes high level, the switch circuit 128 is activated, and the power switch 1 is activated.
All circuits other than those connected to power supply 124 when power supply 25 is turned on are connected to power supply 124. At the same time, the power-up clear circuits 12 and 9 operate, and the output power-up clear pulse is sent to the mode setting circuit 104,
The signal is supplied to the register 106, U, /D counter 113, etc., and these circuits are cleared or reset, so that track address zero is displayed on the display device 107.

In this state, record switch 101 or playback switch 10
2 and designates a desired track address with the track designation switch 105, the track address data n is stored in the register 106, and the display device 107 displays the mode of the device and the designated track address. Then, data 4n is output from the data conversion table 108 and applied to input A of the comparison circuit 114. On the other hand, the output of the U/D counter 113 is given to the input B of the comparison circuit 114, but since the output of the U/D counter 113 is zero at this time, the "A>B" output of the comparison circuit 114 is Becomes a high level. In response to this, the motor control circuit 116 sets the rotational direction designation signal to a high level, instructs the motor 5 to rotate forward, and outputs a pulse from the pulse generator 115 for stepping the motor. As a result, the drive circuit 117 causes the motor 5 to rotate in the forward direction, and the magnetic head 6 is moved from the reference position toward the designated track number n. On the other hand, at this time, due to the motor stop rotation command from the control circuit 116! The DU/D counter 113 operates in an up-count mode, and the magnetic head 6
The motor step pulses corresponding to the step feed are counted. When the magnetic head 6 reaches the track position of address n, at this point the count output of the U/D counter 113 becomes 4n.
=B'' becomes a high level. The multi-control circuit 116 then stops outputting pulses for motor stepping, so the motor 5 stops and the magnetic head 6 stops at the track position of address n.

Here, the operation during reproduction and the operation during recording will be explained.

(1) Operation during playback When playback mode is specified by operating the playback switch 102, the output RP of the mode setting circuit 103 is maintained at a high level, so the output of the OR gate 120 is maintained at a high level. Accordingly, the solenoid drive circuit 121 is maintained in a detached state from the counter 40 of the solenoid 2 during the regeneration operation.
The counter 40 will not be incremented at all.

In the above-described operation, when the head 6 reaches the small rack position specified by the track designation switch 105 and the "A=B" output of the comparison circuit 114 becomes high level, the head 6 is stopped at that position. At this time, the output of the AND gate 109 becomes high level, and the reproduced signal processing circuit 131 is operated to display the reproduced image on the display device 132.

Incidentally, in order to move the magnetic head 6 to the track position n' after the reproduction at the track position n is completed, the track designation switch 105 is used to designate the n' address. At this time, depending on the magnitude of n and n', the "A>B" output or A<B" output of the comparison circuit 114 becomes high level, and as a result, the rotational direction of the motor 5 and the counting mode of the U/D counter 113 are determined. Basically, the magnetic head 6 moves from the track position n to the track position n' in the same manner as the movement from the reference position described above to the track position n; Also, the transmission is performed in units of 4 steps.

Then, when the head 6 reaches the track position n' and the head 6 is stopped at that position by the high level of the "A=B" output of the comparison circuit 114, at this point the output of the AND gate 109 goes high again. Therefore, the reproduced image is displayed in the same manner as described above.

(2) Operation during recording When the recording mode is set by operating the recording switch 101, the output RC of the mode setting circuit 103 is maintained at a high level.

Here, the track address n specified by the track designation switch 105 as described above at this time is n < N with respect to the track address N indicated by the counter 40 of the cassette 20 loaded in the device at this time. In this case, when the head 6 reaches the track number n and stops as described above, the key 45b of the slider 45 is pressed.
Since the contact piece 50 and the contact piece 50' are not yet engaged with the keyway 40b of the counter 40, the contact piece 50 and the contact piece 50' are in a contact state, and therefore,
Since the output of the AND gate 104 becomes low level, recording of the signal is prohibited. At this time, the output of the inverter 123 becomes high level, so that the display device 107 displays that the recording is prohibited.On the other hand, if n≧N, the head 6 is When the track position of the address N is reached in the process of being moved toward the track position of the address, the key 45b of the slider 45 and the keyway 40b of the counter 40 match in phase, so that they are engaged. progress will be made. Further, when the two engage, the contact piece 50 and the contact piece 50' open, and after that, when the head 6 reaches the specified n address track position and the A=B'' output of the comparator circuit 114 becomes high level. , the output of AND gate 104 becomes high level.

As a result, the output of the inverter 123 becomes low level, so that the display prohibiting recording disappears from the display device 107. Then, when the recording start switch 133 is operated with the head 6 stopped at the track position n, the output of the AND gate 134 becomes high level. and gate 13
4 becomes a high level, the recording signal processing circuit 130
is activated, and the video signal is recorded for one field or one frame via the magnetic head 6 on the track at the designated address n of the rotating magnetic disk l. Note that the video signal source at this time may be the output of the video camera built into this device or a separate video camera, or the signal being broadcast.Next, the recording of the track at address n is finished and the other Address n'
When performing recording on a track of 2, if the address n' specified at this time is n'>n, the head 6 is advanced to the track position of address n', and the counter 4 is
0 is also incremented to address n', making it possible to record on the track at address n', but conversely, n' (in the case of n, the quotient of the A<B'' output of the comparison circuit 114 Depending on the level, the flip-flop 119 is set and its Q output becomes high level, so the output of the OR gate 120 becomes high level, which turns on the υ contact piece 50.
Since the contact piece 50' comes into contact with the contact piece 50', recording on the track n' is prohibited by the AND gate 104, and the slider 45 is allowed to idle while the head 6 is moved to the track position n'. become.

Incidentally, if you change the designated track address from n' to A in this write-inhibited state, n# will be n compared to the above n.
If '> n (>n'), the head 6 is moved to the trunk position at address n#, and at this time, the A>B'' output of the comparator circuit 114 becomes high level (n'
>n'), the flip-flop 119 is reset and its Q output goes low, which causes the output of the OR gate 120 to go low, causing the solenoid drive circuit 121 to cut off the excitation of the solenoid 51. Therefore, as described above, when the head 6 reaches the track position n in the process of being moved toward the track position n#, the slider 45 and the counter 40 engage with each other and the counter 40 is advanced to f, and since the contact piece 50 and the contact piece 50' are opened, recording becomes possible. On the other hand, when n' is n,>n'>n', the flip-flop 119 is reset by the high level of the "A>B" output of the comparison circuit 114, and its Q output becomes low level. As a result, the output of the geoagate 120 becomes a low level, and the excitation of the solenoid 51 by the solenoid drive circuit 121 is cut off. slider 45 because the phase is not matched.
is in a detached state from the counter 40, and therefore the contact piece 5
Since the contact piece 50' is in contact with the contact piece 50', the recording line is prohibited. Therefore, in the recording mode, recording is possible only when a track with an address larger than the address of the track on which recording was previously performed is specified.

DETAILED DESCRIPTION OF THE INVENTION According to the present invention, by winding a part of the head carrier in a helical manner and tensioning the biasing spring, the direction of backlash removal with respect to the screw shaft for driving the head carrier can be adjusted. That is, it urges the head carrier in the axial direction and generates rotational force around the guide shaft.
Furthermore, it is possible to generate a biasing force in the radial direction with respect to the guide shaft, and the straightness of the head is improved.

[Brief explanation of the drawing]

18+ to 9 are diagrams for explaining the present invention in detail, FIG. 18+ is a plan view of the cassette, FIG. 18+ is a side sectional view of the cassette, and FIG. 2 is a cassette Fig. 3 111 is a perspective view of the magnetic disk drive shown in Fig. 2 seen from the back side, and Fig. 3 1b+ shows the stepping motor connected to the screw shaft. FIG. 4 is a side sectional view of the magnetic disk drive shown in FIG. 2 taken from section A-A. FIG. 18+ is a perspective view of the magnetic head carrier. 5.1b+ is a plan view of a bimorph equipped with a magnetic head and its support member, FIG. 5.1b+ is a side sectional view of the bimorph shown in FIG. 5.1b+, and FIG. y, m,,-11) Back showing the circuit that activates or deactivates the counter. In the figure, 20 is a magnetic head carrier, 34 is a biasing spring, 33 is a pin for a spring hook, 4a is a spring hook, 26 is a guide shaft, 35 is a leaf spring, 38 is a guide shaft, 37 is a protrusion, 3
9 indicates an adjustment screw.

Claims (1)

[Claims] (1) In a recording and reproducing apparatus that performs recording and reproducing by moving a recording or reproducing head in the radial direction along a guide axis with respect to a disc-shaped recording medium, a part of the head carrier on which the head is mounted has a helical shape. By winding the biasing spring of the head carrier around the head carrier, a moment force is generated in the backlash removal direction and around the guide shaft, and a force that presses the head carrier in the radial direction against the guide shaft is generated. . A head carrier axial vibration prevention mechanism in a recording/reproducing apparatus, characterized in that it absorbs radial play between the head carrier bearing portion and the guide shaft.