JPH0480264B2 - - Google Patents

Description

TECHNICAL FIELD The present invention relates to a linear drive device having an engagement pin that connects a screw shaft rotated by a motor or the like and a driven member for power transmission.

Prior Art For example, in a recording and reproducing apparatus that records or reproduces video signals or data on a disc-shaped recording medium housed in a cassette, recording or reproducing data is performed in a direction perpendicular to a recording track provided annularly on the disc-shaped recording medium. Recording or reproduction is performed by moving the reproduction head. Here, the feeding of the recording or playback head is as follows:
The stepwise rotation of a stepping motor or the like is applied to the screw shaft, and the stepwise circuit is converted into the amount of axial movement of the head carrier through an engagement pin that transmits power and connects the screw shaft and the head carrier that supports the head. Given. Conventionally, an engaging pin is fixed to a head carrier by cutting threads at both ends of the engaging pin and tightening the engaging pin with a nut. However, if the nut is not tightened sufficiently, looseness will occur, and the progressive rotation of the stepping motor will not be accurately transmitted to the recording head carrier, and there are disadvantages in that it takes time and effort to assemble the screw to tighten it.

Purpose of the Invention The present invention solves the drawbacks of the prior art, and provides a power transmission connection for a driven member in a drive device that converts the rotation of a motor etc. into an axial movement amount and moves the driven member in a straight line. To provide a linear drive device capable of simply clamping an engaging pin for use without using a nut or the like, and yet with very high precision and reliability.

Structure of the Invention A linear drive device according to the present invention has an engagement pin fixed to a part of a driven member, rotates a screw shaft that engages with the engagement pin, and moves the driven member in a straight line at two locations. an engaging pin holding member having a hook portion that engages with each end of the engaging pin and attached to the driven member, the driven member having the engaging pin fixed thereto; the engagement pin holding member has a reference surface that is opposite to the plate-like portion, the hook portion is provided on each of the plate-like portions; The engagement pin is attached to the driven member so as to be rotatable around a rotation axis connecting the plate-shaped portions, and the engagement pin is driven by a pressing force generated on the engagement pin holding member by a biasing force in one rotational direction. The hook portion is configured to be fixed to a reference surface of the driven member.

In the description of the embodiment of the linear drive device of the present invention, the case of a magnetic disk recording/reproducing device is described, but the invention is not limited to this, and disk recording/reproducing devices of optical type, capacitive type, etc. Of course, the present invention can be applied to any drive device that converts rotational driving force into linear driving force to move a driven member in a straight line.

Description of Examples (Figures 1 to 9) In the following, embodiments of the invention will be described.

FIG. 1a shows a plan view of the cassette, and FIG. 1b shows a sectional view thereof. In FIG. 1a, 1 is a magnetic disk, and 2 is a flat box-shaped cassette made of resin or the like, and the magnetic disk 1 is housed in the cassette 2. In FIG. magnetic disk 1
A hub 3 is fixed to the center of the hub 3, 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 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 tracks currently on or recorded. 40a 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, and 40b is a hole in which the slider 45 shown in FIGS.
This is a keyway into which a key 45b shown in FIG. 7, which will be described later, is inserted, and also functions as a pointer to indicate the number of recorded tracks on the magnetic disk 1. For example, if 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 points within a range of 360 degrees or less, and the first Outermost track, 50th
If the th track is the innermost track, the 5th track will be described later.
Step drive is applied to the counter 40 in one-to-one correspondence with the amount of movement of the magnetic head carrier 20 holding the magnetic head 6 shown in the figure to each recording track position, and the number of recorded tracks is read from the counter 40. I can do it. In Figure 1b, cassette 2
Openings 2a and 2b are provided on the opposing surface of the magnetic head 6 and the opposite surface thereof, and the magnetic disk 1 is covered except for these openings 2a and 2b. The cassette 2 containing the magnetic disk 1 is
The magnetic surface of the magnetic disk 1 and the magnetic head 6 are mounted by a support mechanism (not shown) so as to face each other through the opening 2a. The magnetic disk 1 has a fourth magnetic disk, which will be described later.
The disc motor 7 shown in the figure rotates at an integral multiple of the field frequency of the standard TV signal, and it rotates concentrically.
A still image is recorded by sequentially forming a TV signal as a circular track by an integer multiple of the field. In an embodiment of the invention, a standard TV
For example, the signal is in the NTSC format, so the field frequency is 60Hz, and the rotation speed of the magnetic disk 1 is
Set the speed to 3600 rpm and record one field per track.

FIG. 2 shows a plan view of the magnetic disk device viewed from the direction opposite to the loading direction of the cassette 2.
5 is a stepping motor for driving the magnetic head 6, and the cassette 2 is indicated by a two-dot chain line.

FIG. 3a shows a perspective view of the magnetic disk device shown in FIG. 2, seen from the back side. In the figure, 4 is a main body chassis, 5 is a stepping motor, and 7 is a disk motor. 20 is a magnetic head carrier that supports the electro-mechanical conversion element 11 to which the magnetic head 6 shown in FIG. 5, which will be described later, is attached;
The cylindrical portion 20b and the arm portion 20c form a substantially L-shape, and a guide shaft 26 is fitted into the cylindrical portion 20b and is supported slidably in the axial direction. Both ends of the guide shaft 26 are connected to shaft fixing portions 2 integrally molded with the main body chassis 4 by shaft fixing plate springs 27.
8 and is pressed and fixed. Reference numeral 25 denotes a clamper shown in detail in FIG. 5, which will be described later, which fixes and holds an engaging pin 23 that engages with a screw shaft 29 with respect to the magnetic head carrier 20. Then, the rotation of the screw shaft 29 is applied to the magnetic head carrier 20 via the engagement pin 23, and the magnetic head carrier 20 is moved in the axial direction along the guide shaft 26. Reference numeral 34 denotes a biasing spring which is a tension coil spring, one end of which is tensioned on a spring hook pin 33, the other end is stretched on a spring hook 4a shown in FIG. It is wound into a shape, and a spring biasing force shown by arrow c is applied.
A rectangular plate spring 35 is fixed to the end of the arm 20c of the magnetic head carrier 20 with a screw 36. Guide shaft 3 that comes into contact with this leaf spring 35
Both ends of the shaft fixing member 8 are pressed and fixed by a shaft fixing portion 37' integrally molded with the main body chassis 4 by a shaft fixing plate spring 37. The leaf spring 35 rotates the magnetic head carrier 20 clockwise or counterclockwise about the guide shaft 26 by adjusting an adjustment screw 39 shown in FIG. 6, which will be described later.
A magnetic head (not shown) supported by 0c can be adjusted so as to be displaced in the direction of protrusion or retraction with respect to the magnetic disk. Reference numeral 32 designates a flexible shaft joint, in which the screw shaft 29 is rotatably supported by a bearing 30, and the bearing 30 is fixed to the main body chassis 4 by a fixing plate spring 31. 58 is a drive cap stan, which has a set screw 5 at one end of the screw shaft 29.
It is fixed by 9. 60 is a wire, one end of which is connected to the drive capstan 58, and the other end is connected to the groove 4 of the drive reel 43 shown in FIGS. 7 and 8, which will be described later.
3a, and each is wound by the required amount. Another groove portion 43 of the drive reel 43
A spring catch 61 is installed in b, and a counter spring 62 is mounted between this spring catch 61 and a spring catch 63 installed in the main body chassis 4 via the groove 43b of the drive reel 43. This counter spring 62
is for applying a rotational force to the drive reel 43 in a direction opposite to the rotational direction of the wire 60. The stepwise rotation of the stepping motor 5 rotates the drive capstan 58 via the flexible shaft joint 32 and the screw shaft 29, winds up the wire 60, feeds the drive reel 43,
gives progressive rotation to . The rotation of the screw shaft 29 is
It is provided to the engaging pin 23 that meshes with the magnetic head carrier 20 to feed the magnetic head carrier 20 in the axial direction in a stepwise manner, and to feed the magnetic disk 1 in the radial direction to the magnetic head 6 provided on the arm portion 20c. can. 51 is a solenoid fixed to the main body chassis 4, 52 is integrally attached to a lever 53 with its iron core, and one end of the lever 53 is rotatably connected to a bell crank 55 by a shaft 54. The shaft 56 is the center of rotation of the bell crank 55. The protrusion 55a of the bell crank 55 is
It is in contact with an arm portion 47a of a clutch lever 47 shown in FIG. 8, which will be described later, and a pin 49 is provided at one end of this lever 47. When the solenoid 51 is excited and the iron core 52 is attracted, the lever 53 is attracted in the direction of the arrow, and the bell crank 55 is moved toward the shaft 56.
By rotating clockwise around the center and pushing down the tip 47a of the crunch lever 47, the third
In figure a, the pin 49 is moved upward relative to the main body chassis 4, the drive reel 43 is moved upward,
As shown in FIGS. 7 and 8, which will be described later, the counter 40
, so that the counter 40 does not transmit the stepwise rotation of the stepping motor 5 . In this state, the movable contact piece 50 and the fixed contact piece 50' come into contact with each other by one end 47a of the clutch lever 47.

In FIG. 3a explained above, the case where the stepping motor 5 and the screw shaft 29 are arranged coaxially has been explained, but as shown in FIG. 3b, the stepping motor 5 is You can also place . In FIG. 3b, a stepping motor 5 is fixed to a wall formed by cutting and raising the main body chassis 4 so as to be perpendicular to the screw shaft 29. As shown in FIG. Reference numeral 301 denotes a rotating shaft of a stepping motor, and a worm gear 302 is attached to the tip thereof, which engages with a worm wheel 303 attached to one end of the screw shaft 29. Numeral 31 is the same fixing leaf spring as shown in FIG. 3a, and fixes the bearing of the screw shaft 29 (30 in FIG. 3a) to the main body chassis 4. According to this configuration, the screw shaft 29 is given a rotational torque in the direction of the arrow by the return spring 62 for the drive reel 43 in FIG. Backlash with the foil 303 can be eliminated, and the magnetic head 6 can be fed with high precision.

FIG. 4 shows a side sectional view of the magnetic disk device shown in FIG. 2, taken along section A-A. In FIG. 4, 1 is a magnetic disk and 2 is a cassette. A spindle 8 fixed to the shaft of a disk motor 7 is fitted into a center hole 3a of a hub 3 provided integrally at the center of the magnetic disk 1.
A ring-shaped adsorption plate 9 made of a soft magnetic material such as iron is attached to the lower part of the hub 3, and the attraction between this adsorption plate 9 and a ring-shaped magnet 10 fixed to the groove of the spindle 8 causes , the height reference surface 3b of the hub 3 is brought into contact with the reference surface 8a of the spindle 8. The hub 3 and spindle 8 are driven by a disk motor 7 and rotated together. Reference numeral 12 supports at its fixed end an electro-mechanical transducer element 11 (hereinafter simply referred to as bimorph) consisting of a pair of rectangular plate-shaped piezoelectric bodies shown in FIG. 5, which will be described later, with a magnetic head 6 attached to its free end. This bimorph support member 12 has two positioning holes 12e and 12f.
is provided. 14 is a bimorph support member 1
It is an almost L-shaped mounting member to which 2 is attached,
This mounting member 14 is provided with a positioning conical pin 15 and an adjusting conical screw 16. The positioning conical pin 15 is fixed to the mounting member 14, and the adjusting conical screw 16 can be moved 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 conical positioning pin 15 and the conical adjusting screw 16, the conical pin 15 can be moved to the pivot point by adjusting the conical screw 16. The position of the recording head 6 can be adjusted in a direction perpendicular to the recording track.

Two positioning holes 14a are provided on a surface of the L-shaped mounting member 14 that is different from the surface on which the positioning conical pin 16 and the adjusting conical screw 16 are provided. The conical slopes of two conical positioning pins 21 are engaged with the positioning hole 14a. 24
23 is a pressing spring, and 23 is a set screw. By using this and the adjustment screw 22, the mounting member 14 can be pivotally supported on the magnetic head carrier 20 so that its position can be adjusted.

FIG. 5a is a perspective view showing the magnetic head carrier in detail. FIG. 5b shows the magnetic head carrier 20 supporting the magnetic head 6 in the same figure.
The bimorph support member 12 shown in FIG.
The description will be given with reference to the side sectional view shown in FIG.

The magnetic head 6 is fixed to the free end of the bimorph 11. This bimorph 11 is used as a means for correcting the track deviation of the head 6 during reproduction of a recorded magnetic disk by deformation due to its piezoelectric effect. As shown in FIG. 5b, the bimorph 11 is provided with a U-shaped notch 11a on the side opposite to the side supporting the magnetic head 6. Reference numeral 12 denotes a bimorph support member, and as shown in FIG. A screw hole 12b is provided on one side of the part sandwiching this groove 12a.
A hole 12c slightly larger in diameter than the screw hole 12 is coaxially provided on the other side. The bimorph 11 is inserted into the groove 12a of the bimorph support member 12 so that the center of the U-shaped notch 11a substantially coincides with the centers of the screw holes 12b and 12c, and the screw 13 is inserted as shown in FIG. 5a. By fastening, the protrusion 1 of the bimorph support member 12
By deforming 2d to the screw hole 12b side,
One end of the bimorph 11 is supported by a clamp. Attachment member 14 to which bimorph support member 12 is attached
is formed into a substantially L-shape, and two positioning holes 12e and 12e provided in the bimorph support member 12 are formed.
12f, as shown in FIG. 4, a conical positioning pin 15 and a conical adjustment screw 16 are arranged, the positioning conical pin 15 is fixed to the mounting member 14, and the conical adjustment screw 16 is screwed together, and the conical adjustment screw 16 screw 1
6 can be moved forward and backward by adjusting screws.
The bimorph support member 12 is attached to the mounting member 14 by the mounting screws 17 and 18 as shown in FIG. 5a through the screw insertion holes 12g and 12h provided in the bimorph support member 12 shown in FIG. 5b. . At this time, the mounting screw 17 is
, the bimorph support member 12 is attached to the mounting member 14.
Apply spring bias in the direction of . Then, when the azimuth adjustment screw 18 is rotated, the positioning conical pin 15 and the adjustment conical screw 16 are rotated.
Since the inclined surfaces of the conical ends of each of the two sides engage with the positioning holes 12e and 12f of the bimorph support member 12, the conical portions at the two locations are used as pivot points, and the fifth
Azimuth adjustment screw 1 is biased to rotate in the direction of arrow A shown in Figure a and screwed to mounting member 14.
Its rotation is prevented by the collar section 8. Therefore,
By rotating the azimuth adjustment screw 18,
It is possible to finely adjust the deflection in the direction of arrow A shown in FIG. 5a, that is, the azimuth adjustment direction.

Furthermore, by rotating the adjusting conical screw 16 shown in FIG. 4, the tilting of the magnetic head 6 can be adjusted in the direction of arrow A using the positioning conical pin 15 as a pivot point, that is, in the direction orthogonal to the recording track. I can do it.

Furthermore, as shown in FIG. 4, two positioning holes 14a are provided on the side of the L-shaped mounting member 14 that is different from the side on which the positioning conical pin 15 and the adjusting conical screw 16 are disposed. Positioning hole 14a
Correspondingly, two positioning conical pins 21 are implanted in the head mounting member 20a of the magnetic head carrier 20 provided with the mounting member 14.
The conical slope of the conical positioning pin 21 is engaged with the positioning hole 14a, and the magnetic head carrier 20 is attached to the magnetic head carrier 20 by a set screw 23 via an adjustment screw 22 and a pressing spring 24, as shown in FIG. 6, which will be described later. Then, similarly to the azimuth adjustment described above, the mounting member 14 is
The positioning conical pin 21 is used as a pivot point, and as shown in FIG. Therefore, by adjusting the rotation of the adjusting screw 22, the magnetic head 6 can be adjusted in the direction of the arrow A in FIG. 6, that is, the magnetic head 6 can be tilted in the recording track direction using the conical positioning pin 21 as a pivot point.

To summarize the adjustment of the magnetic head described above, by fine adjustment of the adjustment screw 22, the mounting member 14
The positioning conical pin 21 is used as a pivot point, and the tilt adjustment of the magnetic disk 1 in the track direction can be given to the magnetic head 6 (6th position).
figure).

As shown in FIGS. 4 and 6, the mounting member 14
The positioning conical pin 15 provided on the mounting member 14 by fine adjustment of the adjustment screw 16 fitted in the
is used as a pivot point, and tilt adjustment can be applied in a direction perpendicular to the magnetic track 1.

As shown in FIG. 5a, by finely adjusting the azimuth adjustment screw 18 provided on the bimorph support member 12 that supports the bimorph 11 together with the magnetic head 6, the bimorph is brought into contact with the positioning conical pin 15 and the adjusting conical screw 16. By using the positioning holes 12e and 12f provided in the support member 12 as pivot points, fine adjustment can be made in the direction of arrow A shown in FIG. 5a, that is, in the azimuth direction.

In order to perform each of the above-mentioned adjustments well, as can be understood from FIG.
5 and adjustment screw 16 are on a perpendicular line passing through the magnetic head 6 in FIG. , and the two conical pins 21 are also perpendicular to the above-mentioned vertical line, and also on the surface of the mounting member 14 on which the conical pin 15 and the adjusting screw 16 are disposed. It is best to arrange them so that they are on orthogonal lines, but of course the invention is not limited to this.

Next, the structure and operation of the magnetic head carrier 20 will be described. As shown in FIG. ,
Sintered bearings 22 are coaxially press-fitted from both ends of the cylindrical portion 20b. Projections 20d are provided at two locations on the side surface of the cylindrical portion 20b, and as explained in FIG. , corresponding to the advance angle of the screw shaft 29 and inclined at a predetermined angle with respect to the axes of the two sintered bearings 22.

Reference numeral 25 denotes a clamper, which is approximately U-shaped, has two hooks 25a, and has two protrusions 25b facing each other on the U-shaped inner wall. A tap hole 25d is provided approximately at the center of the arm portion 25c that is connected to the U-shaped portion of the clamper 25. 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 to form a U-shaped portion. The two protrusions 25b provided on the inner wall of the cylindrical portion 20b are pushed in until they are inserted into the clamper engagement holes 20f provided on the upper and lower surfaces of the cylindrical portion 20b. The protrusion 25b is the clamper coupling hole 20
When inserted into the clamper 25, it returns to its original shape due to the elastic force of the clamper 25.
5 is rotatably supported by the magnetic head carrier 20 around the clamper engagement hole 20f.

Next, attach the engagement pin 23 to the groove 20e, and insert the clamp screw 25f into the tap hole 25d of the clamper 25.
By inserting and tightening the clamp screw 2,
The clamper 25 is rotated counterclockwise around the clamper engagement hole 20f by the reaction force generated when the tip of the clamper 5f presses against the side surface of the cylindrical portion 20b, so that the clamper 25 is rotated at the inclined surface of the hook portion 25a of the clamper 25. As shown in more detail in FIG. 3, the engaging pin 23 is fixedly supported on the cylindrical portion 20b by pressing the engaging pin 23 against a surface perpendicular to the groove portion 20e.

In this case, the reaction force that is applied to the hook portion 25a by pressing the engagement pin 23 is received in the direction of the plate surface of the clamper 25. Therefore, the clamper 25 exhibits high rigidity in the direction of the plate surface. The deformation is small, and the elastic deformation in the thickness direction of the arm portion 25c of the clamper 25 generates a pressing force against the engagement pin 23, thereby making it possible to hold the engagement pin 23. The reaction force at the pressing part of the clamper 25 against 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 of the member in the bending direction, so pressure can be managed. In addition to the advantage of being easy to use, there is an advantage that the engagement point between the engagement pin 23 and the screw shaft 29 can be set near the guide shaft 26 by increasing the thickness of the magnetic head carrier in the thickness direction of the device by the thickness of the plate. be.

FIG. 6 shows the magnetic disk device shown in FIG.
It is a side sectional view seen from a cross section. In Figure 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 latched to a spring hook pin 33 implanted in the magnetic head carrier 20, and the other end of this spring 34 is hooked to a spring hook portion provided on the main body chassis 4. It is latched to 4a. This spring 34 is connected to the spring hook pin 33 and the spring hook 4.
When the magnetic head carrier 20 is stretched over the magnetic head carrier 20, it is wound helically around the cylindrical outer wall of the cylindrical portion 20b, so that a spring biasing force shown in the direction of the arrow c is applied to the cylindrical portion 20b as shown in FIG. At the same time, a rotational moment about the guide shaft 26 is applied in the direction shown by arrow C in FIG. This generates a radial bias force on the magnetic head carrier 20 with respect to the guide shaft 26 at the abdomen of the spring 34, thereby giving the magnetic head carrier 20 the effect of preventing shaft vibration. In addition, guide shaft 2
There is a radial distance of about several micrometers between 6 and 38, but this distance 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. A protrusion 37 made of a high friction material is implanted in the leaf spring 35. This protrusion 37 is connected to the guide shaft 3 fixed to the main body chassis 4 in the same way that the guide shaft 26 is given a rotational moment in the direction of arrow C.
8 and is in contact with it with a rotational moment.
The biasing force of the magnetic head carrier 20 in the direction shown by the arrow C generated by the biasing spring 34 can eliminate the backlash at the engagement portion between the engagement pin 23 and the screw shaft 29 shown in FIGS. 3 and 5. can.

In short, the sliding direction of the magnetic head carrier 20 is uniquely determined by the guide shaft 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 mounting portion of the leaf spring 35 provided on the arm portion 20c of the magnetic head carrier 20, and the adjustment screw 39 is inserted in the advancing direction of the adjustment screw 39 against the elastic force of the leaf spring 35. When tightened, the leaf spring 35 deforms downward relative to the magnetic head carrier 20. The magnetic head carrier 20 receives a reaction force due to its deformation, and the guide shaft 2
Rotate clockwise around 6. 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, adjustment screw 3
9, the magnetic head 6 can be moved to the magnetic disk 1.
The position can be adjusted in the protruding or retracting direction. In this case, the guide shaft 26 also receives rotational torque, but the actual magnetic head protrusion adjustment amount is around 20 μm, and the distance a, which is the length of the arm 20c of the magnetic head carrier 20, is 20 mm.
Since it is both front and back, the angle of inclination is less than a few minutes, which is virtually no problem.

7 and 8 are a side sectional view and a side view of the counter as seen from the line CC and D of the magnetic disk device shown in FIG. 2, respectively.

In FIG. 7, 41 is a shaft implanted and fixed to a counter shaft 42 that is integrally attached to the main body chassis 4, and 43 is a drive reel rotatably supported around the shaft 41. A locking ring 44 attached to the shaft 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 slidably supported in the thrust direction of the shaft 41 by vertical movement of a pin 49 shown in FIG. 8, which will be described later. The slider 45 has a drive reel 43
A protrusion 45c protruding in the direction is provided, and is fitted into an engagement hole (not shown) provided in the drive reel 43 so as to be slidable in the thrust direction, and the slider 45
rotates together with the rotation of the drive reel 43. The slider 45 includes a groove 45a into which a pin 49 shown in FIG. 8, which will be described later, is fitted, and a key 45b which is inserted and fitted into a keyway 40b of the counter 40 shown in FIG. 1a. A cap 46 is press-fitted onto the shaft 41 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. In addition,
The clutch lever 47 is provided with a spring 48',
A rotation moment shown in the arrow direction A is applied to the clutch lever 47. A pin 49 is implanted at the other end of the clutch lever 47, and this pin 49 fits into the groove 45a of the slider 45. The clutch lever 47 includes an arm portion 47a on the side opposite to the side where the pin 49 is installed. Referring also to FIG. 3a, 51 is a solenoid; 52 is a solenoid;
is the iron core of the solenoid 51, and 53 is a lever that connects the iron core 52 and the pel crank 55. A shaft 54 rotatably supports the lever 53 on a bell crank 55. 56 is a shaft that fixes the center of rotation of the bell crank 55 relative to the main body chassis 4. When the clutch lever 47 is rotated clockwise or counterclockwise about the shaft 48, the arm portion 47a moves the slider 45 against the counter 40.
The key 45b is inserted into or removed from the keyway 40b. As seen in FIG. 3a, the protrusion 55a of the bell crank 55 is in contact with the arm 47a of the clutch lever 47, and when the solenoid 51 is energized, the iron core 52 is attracted in the direction of the arrow, and the lever 55 is in contact with the arm 47a of the clutch lever 47.
3 also move in the same direction, thereby causing the bell crank 55 to rotate clockwise. bell crank 55
8, the bell crank protrusion 55a pushes the arm 47a of the clutch lever 47, and the clutch lever 47 shown in FIG.
Move in the evacuation direction. In this state, even if the slider 45 rotates, the key 45b is removed from the keyway 40b of the counter 40, so the rotation of the slider 45 is not transmitted to the counter 40, and therefore the counter 40 is not connected to the magnetic disk 1. An indication of the number of tracks recorded so far can be retained. Then, the piece 50 and the fixed piece 50' come into contact and form an electrically conductive state, thereby putting the circuit device of the magnetic recording/reproducing apparatus (not shown) in a write inhibit mode. Note that 57 is made of an insulating material,
Sections 50 and 50' are joined.

When the solenoid 51 is de-energized, the elastic force of the spring 48' causes the clutch lever 4 to
7 is spring-biased in the direction of the arrow in FIG.
When the phase of the key 45b of the slider 45 matches, the slider 45 is raised and the key 45b of the slider 45 is raised.
is inserted into the keyway 40b. As a result, the section 50 and the fixed section 50' are separated, and electrical continuity is broken.

Therefore, when a cassette containing a partially recorded magnetic disk is removed and the cassette is then loaded to continue recording, the counter 40 provided in the cassette will calculate the value of the maximum number of tracks recorded. Since it is still held, the value of the maximum number of recorded recording tracks mentioned above is changed to the value of the maximum number of recorded tracks when the switch consisting of the section 50 and the fixed section 50', which is generated when the key 45b is inserted into the keyway 40b, is opened. It can be detected from Therefore, since it is possible to continue recording from the track immediately following the largest recorded track, overwriting on the recorded track is prevented.

During playback, all recorded tracks are generally accessed randomly, so in such a case, when the phases of the key 45b of the slider 45 and the keyway 40b of the counter 40 match, the key 45b becomes the key. If the slider 45 is inserted into the groove 40b, the rotation of the slider 45 will be controlled by the counter 40.
The counter 40, which was indicating the maximum number of recorded tracks on the magnetic disk 1 on which magnetic recording was performed before playback, was incremented, and the maximum number of recorded tracks on the magnetic disk 1 was incremented. There is a risk that the value of 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 40, the rotation of the slider 45 is not applied to the counter 40. Therefore, the counter 40 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 magnetic head on the recording track and the track designated position of the counter 40 will be explained with reference to FIGS. 3 and 8.

In FIG. 3a, the drive cap stan 58
is fixed to one end of the screw shaft 29 by a set screw 59, and is configured to rotate together with the screw shaft 29. The end of the wire 60 wound around the capstan 58 is connected to the reel 4 shown in FIG.
It is fixed in the groove 43a of No. 3 and wound by the required amount. A spring hook 61 is planted in the other groove 43b of the drive reel 43, and a counter spring 62 is mounted on this spring hook 61 so as to be wound around the groove 43b of the slider 43. The end is latched onto a spring hook 63 planted in the main body chassis 4. Therefore, the drive 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 drive capstan 58 and the drive reel 43 are appropriately selected, the diameters of the drive capstan 58 and the drive reel 43 will correspond to a predetermined angle of the counter click mechanism (not shown).
In other words, the counter 40 can be driven in one-to-one correspondence with the rotation angle of the stepping motor 5, that is, the track feed of the magnetic head 6.

Also, the position of the magnetic head 6 of the first recording track on the magnetic disk 1 and the counter 40
Adjustment with the indicated position indicating the first recording track is performed by rotating the stepping motor 5.
The magnetic head 6 is positioned on the first recording track, and then, in this state, the set screw 59 is loosened and the drive capstan 58 is rotated relative to the screw shaft 29, thereby rotating the drive reel 43 and pressing the key on the slider 45. 45b is exactly the first
The phase of the counter can be adjusted by adjusting the value of the th recording track to be indicated by the counter 40.

FIG. 9 shows that when the magnetic 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. In the normal recording or reproducing operation after being reset to the reference position, a control system configured to advance 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
103 is a playback switch, and 103 is a mode setting circuit. The mode setting circuit 103 includes switches 101,
In response to each operation of 102, output in recording mode.
Only RC is set to a high level, and only output RP is set to a high level in playback mode, and these outputs are sent to an AND gate 104 for recording operation control and an AND gate 109 for playback operation control, respectively, and to "A" of a comparison circuit 114, which will be described later. =B'' is applied together with an enable signal that is generated when the output becomes a high level, and the AND gate 104 is further provided with the contact piece 50 shown in FIG.
When the contact piece 50' 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.

Reference numeral 105 denotes a track designation switch for designating a desired track, and is constituted by, for example, a numeric keypad. 106 is a register for storing data n regarding the specified track address by the track designation switch 105, and 107 is for storing data n regarding the specified track address stored in the register 106, as well as the setting mode (recording or playback) of the device and the recording prohibited state in the recording mode. It is a display device for displaying images. For this purpose, in addition to the output of the register 106, the display device 107 is provided with the output of an inverter 122 that inverts the outputs RC and RP of the mode setting circuit 103 and the output of the AND gate 104. The display device 107 is preferably a small display made of liquid crystal, electrochromic, light emitting diode, or the like. 108 is a data conversion table made of, for example, ROM, and in this example, it is used as head position setting data.
Outputs 4n. Here 4n is the designated switch 10
Data n (for example,
(converted to digital data using binary code), the stepping motor 5 for moving the head
This is the recording head position setting data with a numerical value corresponding to the head movement of 4 steps per track pitch according to (FIG. 3).

113 is an up-down counter (hereinafter abbreviated as U/D counter) for detecting the position of movement of the magnetic head 6 by the stepping motor 5;
4 is 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)
This is a comparison circuit that compares the outputs A and B, and outputs three types of signals, "A>B", "A=B", and "A<B", depending on the magnitude of the outputs A and B. Reference numeral 115 denotes a pulse generator, and the stepping motor 5 is driven based on a stepping pulse outputted from the pulse generator. The following description will be made on the assumption that one stepping pulse is sent by one step. 116 is 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, the comparison circuit 11
4, the motor 5 rotates forward in response to the high level of "A>B", and the motor 5 rotates in the reverse direction in response to the high level of "A<B", resulting in the high level of "A=B". It has a function of stopping the motor 5 by cutting off the supply of pulses to the drive circuit 117 in response. The control circuit 116 outputs a rotation direction designation signal that designates forward or reverse rotation of the motor 5 and pulses for rotational drive. For example, when this rotation direction designation signal is at a high level, forward rotation is performed, and when this is at a low level, it is determined that the rotation direction designation signal is command to reverse. 117 is a motor drive circuit that rotates the motor 5 by a specified amount in a specified direction based on the output of the control circuit 116; 118 is a comparison circuit 114;
This is an OR gate which receives as inputs the "A<B" output of 1 and the output of a reset circuit 127, which will be described later, and its output is connected to the reverse 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 rotates 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 counter pulse, respectively. In this case, the U/D counter 113 enters the up-count mode in response to the high level of the rotation direction designation signal, that is, a forward rotation command, and the down-count mode in response to a low level, that is, a reverse rotation command.
mode is set.

Reference numeral 119 indicates a rising synchronization type RS flip-flop which is set by the high level of the "A<B" output of the comparison circuit 114 and reset by the high level of the "A>B" output, and 120 indicates the Q output of this flip-flop 117 and the mode. Output of setting circuit 103
An OR gate 121 which receives RC and the output of the reset circuit 127 is a solenoid drive circuit which excites the solenoid 51 shown in FIGS. 3a and 8 in response to the output of the OR gate 120. 133 is a recording start (trigger) switch, and 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 of which is given to the recording signal processing circuit 130 as a control signal.

124 is a power supply, 125 is a power switch,
By turning on the power switch 125, the pulse generator 115, control circuit 116, drive circuit 117, OR gates 118 and 120, and flip-flop 11 are turned on.
9, a solenoid drive circuit 121, a reference position detection device 126 and a reset circuit 127 for the stepping motor 5 and the magnetic head 6 (generally a transducer) are connected to a power source 124.
In addition, the disk motor (7 in Figures 3a, 4, and 6)
It is also possible to connect to the power supply 124 together with this. The reference position detection device 126 is the magnetic head 6
is sent toward the reference position, and when the reference position is detected, a reference position detection completion signal is generated, which is sent to the reset circuit 127. Reset circuit 12
7 supplies a reset signal for moving the magnetic head 6 to a reference position outside the first track of the magnetic disk (1 in FIG. 1) to the control circuit 116 via an OR gate 118 until the reference position is detected. Continue to supply. In response to this reset signal, the control circuit 116 controls the motor 5 until it is released.
Outputs a rotation direction designation signal and pulses to reverse the rotation direction.

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 turns on the power supply 124 by turning on the switch 125. Connected. At the same time, the power up clear circuit 129 operates, and the mode setting circuit 104 and register 106 operate.
A power up clear pulse (PUC) is applied to the U/D counter 113 and the like to clear or reset these circuits.

130 is a recording signal processing circuit for supplying the 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 corresponding AND gates 121 and 122, respectively. 13
2 shows 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 115, control circuit 116, drive circuit 117, OR gates 118 and 120, and flip-flop 1
19, the solenoid drive circuit 121, the 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 is
The reset signal is supplied to the control circuit 116 via the OR gate 118 until the magnetic head 6 reaches the reference position. As a result, 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 the reverse direction, and outputs a motor stepping pulse from the pulse generator 115. As a result, the drive circuit 117 rotates the motor 5 in the reverse direction, and if the magnetic head 6 is not at the reference position, it is moved until it reaches the reference position.
During this time, 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, so that the slider 45 is activated so that its key 45b is not in the cassette. It will spin idly in a state where it is detached from the counter 40 on the second side. 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 also stops at that position. Further, as a result of this, the output of the OR gate 120 becomes a low level, so the solenoid drive circuit 121 cuts off the excitation of the solenoid 51, and the slider 45 is therefore biased in the direction of engagement with the counter 40 by the clutch lever 47. . However, in this state, the key 45b of the slider 45 is not in phase with the keyway 40b of the counter 40, and therefore, the two have not yet engaged.

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 all circuits other than those connected to the power supply 124 when the power switch 125 is turned on are powered on. 124. Along with this, the power up clear circuit 12
9 operates, and its output, the power up clear pulse, is sent to the mode setting circuit 104, register 1.
04, is supplied to the U/D counter 113, etc., and these circuits are cleared or reset, so that the track address zero is displayed on the display device 107.

In this state, when you press the record switch 101 or playback switch 102 and specify a desired track address using the track designation switch 105,
The track address data n is stored in the register 106, and the display device 107 displays the track address specifying the mode of the device. 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, comparison circuit 1
The output of the U/D counter 113 is given to the input B of 14;
Since the output of the comparator circuit 114 is zero, “A>” of the comparator circuit 114
B" output becomes high level. As a result, the control circuit 116 sets the rotation direction designation signal to a high level and instructs the motor 5 to rotate forward, and the pulse generator 11
Outputs motor stepping pulses from 5. As a result, the drive circuit 117 causes the motor 5 to rotate in the normal direction, and the magnetic head 6 is moved from the reference position toward the designated track at address n. On the other hand, at this time, the U/D counter 113 operates in an up-count mode in response to a motor normal rotation command from the control circuit 116, and counts pulses for motor advancement corresponding to step feeding of the magnetic head 6. When the magnetic head 6 reaches the track position of address n, at this point the U/D
The count output of the counter 113 becomes 4n, and therefore "A=B" among the outputs of the comparison circuit 114 becomes high level. As a result, the control circuit 116 stops outputting the motor stepping pulse, 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 the playback mode is specified by operating the playback switch 102, the output of the mode setting circuit 103
Since RP is maintained at a high level, the output of OR gate 120 is maintained at a high level, which causes solenoid drive circuit 121 to maintain solenoid 51 in an energized state during the regeneration operation. Therefore, during the reproduction operation, the slider 45 is maintained in a detached state from the counter 40 of the cassette 2, and the counter 40 is not incremented at all.

When the head 6 reaches the track position designated by the track designation switch 105 through the above-described operation and the "A=B" output of the comparator 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, whereby the reproduction signal processing circuit 131 is activated and the reproduced image is displayed on the display device 132.

Incidentally, in order to move the magnetic head 6 to the track position n' after the playback at the track position n is completed, the track designation switch 10 is pressed.
5 specifies address n'. At this time, depending on the magnitude of n and n', the "A>B" output or "A<B" output of the comparator circuit 114 becomes high level, and as a result, the rotation direction of the motor 5 and the U/D counter 11
3 counting modes are determined, but basically,
The magnetic head 6 moves from the n-th track position to the n' track position in the same manner as the movement from the reference position to the n-th track position described above, and in this case as well, the magnetic head 6 moves in units of 4 steps. will be carried out.

Then, when the head 6 reaches the track position of address n' and the head 6 is stopped at that position by the high level of the "A=B" output of the comparator 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 of the mode setting circuit 103
RC 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 2 loaded in the apparatus at this time. In some cases, when the head 6 reaches the track number n and stops as described above, the key 4 of the slider 45 is pressed.
5b is not yet engaged with the keyway 40b of the counter 40, the contact piece 50 and the contact piece 50' are in contact with each other. Therefore, the output of the AND gate 104 becomes a low level, and the signal is not recorded. It will be banned. At this time, the output of the inverter 123 becomes high level, so that
The display device 107 now displays that the recording is prohibited.

On the other hand, when n≧N, the head 6 is n
When it reaches the track position of address N in the process of being moved toward the track position of the address, the key 45b of the slider 45 and the keyway 4 of the counter 40
By matching the phase with 0b, both engage,
From then on, the counter 40 starts incrementing. Further, when the two engage, the contact piece 50 and the contact piece 50' open, and then the head 6 reaches the specified n address track position and the "A=B" output of the comparator circuit 114 becomes high level. Then, the output of the 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 of address n, the AND gate 1 is activated.
The output of 34 becomes high level. and gate 1
34 becomes a high level, the recording signal processing circuit 130 is activated, and the video signal is sent to the specified address n of the rotating magnetic disk 1 via the magnetic head 6.
One field or one frame is recorded on this track. Note that the video signal source at this time may be the output of a video camera built into the present device, a separate video camera, or a signal being broadcast.

Next, when you finish recording the track at address n and start recording on the track at another address n', if the address n' specified at this time is n'>n, head 6 is It is advanced to the track position of address n′,
Further, the counter 40 is also incremented to address n', making it possible to record on the track at address n'. Conversely, if n'<n, the comparator circuit 11
The flip-flop 119 is set by the high level of the "A<B" output of 4, and its Q output becomes a high level, so the output of the OR gate 120 becomes a high level, and this causes the solenoid drive circuit 12
1 excites the solenoid 51 to separate the slider 45 from the counter 40. As a result, the contact piece 50
AND gate 1 is in contact with contact piece 50'.
04 prohibits recording on the track at address n', and the slider 45 idles while the head 6 is moved to the track position at address n'. By the way, if you change the specified track address from n' to n'' in this recording prohibited state,
If n″ is n″>n (>n′) for the above n, then
The head 6 is moved to the track position of address n'', and at this time, the comparator circuit 114 indicates "A>B".
Since the output goes to a high level (because n''>n'), flip-flop 119 is reset and its Q
The output is at a low level, which causes OR gate 1
20 becomes a low level, so that the solenoid drive circuit 121 cuts off the excitation of the solenoid 51. Therefore, in the process of moving the head 6 toward the track position n'' in the same manner as described above, when the head 6 reaches the track position n, the slider 45 engages with the counter 40, and the counter 40
n'', and the contact piece 50 and the contact piece 5
0' is opened, making recording possible. On the other hand, when the above n'' is n n''>n', the comparator circuit 11
The flip-flop 119 is reset by the high level of the "A>B" output of No. 4, and its Q output becomes a low level, so that the output of the OR gate 120 becomes a low level and the excitation of the solenoid 51 by the solenoid drive circuit 121 is cut off. However, in this state, the key 45b of the slider 45 and the keyway 40b of the counter 40 are not in phase, so the slider 45 is in a detached state from the counter 40, and therefore is not in contact with the contact piece 50. Recording will be inhibited due to the contact of the pieces 50'. Therefore, in the recording mode, recording is possible only when a track with an address larger than the address of the track previously recorded is specified.

Effects of the Invention As explained above, according to the present invention, the hook portions for pressing the engagement pin and fixing it to the driven member are provided on the opposing plate-like portions formed on the engagement pin holding member,
An engagement pin holding member is attached to the driven member so as to be rotatable around a rotation axis connecting the opposing plate-shaped parts, and the engagement pin is generated in the engagement pin holding member by a biasing force in one rotational direction. Since the hook portion is fixed to the reference surface of the driven member by the pressing force, the engagement pin can be fixed to the driven member with a single touch, which improves work efficiency during assembly. can be improved,
Furthermore, although the configuration is simple, the engagement pin can be clamped accurately and reliably.

[Brief explanation of the drawing]

1a to 9 are diagrams for explaining an embodiment of the present invention, in which FIG. 1a is a plan view of the cassette, FIG. 1b is a side sectional view of the cassette, and FIG. 2 is a cassette. FIG. 3a is a plan view of the magnetic disk device seen from the opposite direction to the loading direction; FIG. 3a is a perspective view of the magnetic disk device shown in FIG. A plan view when installed in the direction perpendicular to the axis, Figure 4 is the second
FIG. 5a is a perspective view of a magnetic head carrier, FIG. 5b is a plan view of a bimorph equipped with a magnetic head and its support member, and FIG. Figure 5c is Figure 5b
6 is a side sectional view of the magnetic disk device shown in FIG. 2 taken along section B-B, and FIG. 7 is a side sectional view of the magnetic disk device shown in FIG. A side sectional view of the counter seen from C,
FIG. 8 shows the magnetic disk device shown in FIG.
FIG. 9, a side cross-sectional view, shows a circuit for activating or deactivating the counter by a control circuit that provides feed to the recording head. In the figure, 5...stepping motor, 29...screw shaft, 20...recording head carrier, 20d
...Protrusion, 20e...groove, 20f...clamper engagement hole, 23...engaging pin, 25...clamper,
25b...Protrusion, 25a...Hook part, 25c...Arm part, 25d...Tap hole, 25f...Clamp bis.

Claims (1)

[Scope of Claims] 1. A drive device in which an engaging pin is fixed to a part of a driven member, and a screw shaft that engages with the engaging pin is rotated to move the driven member in a straight line, wherein the engaging pin is fixed at two locations. an engagement pin holding member having a hook portion that engages with each end of the pin and attached to the driven member, the driven member having a reference surface to which the engagement pin is fixed; The engagement pin holding member has opposing plate-like parts, the hook parts are provided on each of the plate-like parts, and the engagement pin holding member has opposing plate-like parts. The engagement pin is attached to the driven member so as to be rotatable around a rotation axis, and the engagement pin is moved by the hook portion by a pressing force generated on the engagement pin holding member by a biasing force in one rotational direction. A linear drive device, characterized in that it is fixed to a reference surface of the driven member.