JPH0423349B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a disk-shaped recording/reproducing device that uses a disk-shaped recording medium such as a magnetic disk.

A magnetic disk device is an example of a disk-type recording/reproducing device. In magnetic disk drives, it is necessary to move the magnetic head in the radial direction of the disk. Therefore, it has been proposed to use a rotary stepping motor, convert the rotational force of this motor into linear motion using a steel belt, etc., and move the head carriage linearly in the radial direction of the disk. . In addition, a magnetic head is attached directly to the moving element of a linear pulse motor or a voice coil motor, and the head is moved in the radial direction of the disk.

However, the conventional apparatus described above has a problem in that it is expensive because it is necessary to include a motor for moving the head in addition to a motor for rotating the disk. In addition, since the motor itself for moving the head needs to move intermittently, there is also the problem that an expensive motor must be used.

An object of the present invention is to enable the head to be moved intermittently by a continuously rotating motor, and thus to allow a single motor to rotate the disk and move the head. The object of the present invention is to provide a disk-type recording/reproducing device.

The invention will now be described with reference to illustrated embodiments.

First, an example of a magnetic disk applicable to the apparatus of the present invention will be explained with reference to FIGS. 1 to 3. The magnetic disk shown in FIGS. 1-3 is in the form of a cassette. That is, the magnetic disk cassette 1 is mainly composed of a flat box-shaped hard case 2 and a flexible disk 3 rotatably housed within the hard case. A disk hub 4 is integrally provided at the center of the disk 3. The disk hub 4 is provided with conical protrusions 5 on the upper and lower surfaces of its center, and an annular protrusion 6 is formed around these protrusions 5, and the inner side of the protrusion 6 is provided with the following. spindle hub 10
An engagement protrusion 7 having a triangular cross section is provided for engaging with the protrusion 5 to rotationally drive the disk hub 4. The disk hub 4 having these protrusions 5, 6, etc. is exposed through a window hole formed in the case 2. An opening 8 is provided at one side edge of the case 2 on the upper and lower surfaces so that a magnetic disk can enter and come into contact with the recording surface of the disk 3. At the edge of the case 2 where the opening 8 is formed, a stepped portion is formed that is slightly lower than the upper and lower surfaces of the case 2.
A shutter plate 9 is attached to this step so as to sandwich the case 2 from above and below, and to be slidable along the step. Window holes 10 are formed in the shutter plate 9 so that the magnetic heads can enter and come into contact with the recording surface of the disk 3 so that they overlap one another. A pair of folding pieces 12 and 13 are formed on the shutter plate 9, and a pair of guide pieces 14 and 14 are also formed by folding down. The guide pieces 14, 14 are formed in guide grooves 18, 18 formed along one side edge of the case 2.
It is fitted into the shutter plate 9 to guide the sliding movement of the shutter plate 9. Cutting edges 15 and 16 are formed in the opening 8 of the case 2 so as to be continuous with the opening, and when the shutter plate 9 moves to the left in FIG. It is designed so that it does not come into contact with the edge of the opening 8. The case 2 also includes, at the sliding part of the shutter plate 9,
A mounting groove 17 for mounting the J-shaped bent portion 11a of the spring 11, and notches 19, 20 into which pins (described later) for sliding the shutter plate 9 in parallel with the guide grooves 18, 18 should slide. is formed. The bent portion 11a of the spring 11 is fitted into the mounting groove 17 and then welded by heating the periphery of the mounting groove 17. The shutter plate 9 is attached to the case 2 while pushing open the upper and lower overlapping parts vertically. In that case, the guide pieces 14 of the shutter plate 9 are connected to the guide grooves 18, 18 of the case 2 from the notches 27, 27.
Infiltrate 14. At this time, the left end of the shutter plate 9 in FIG. 2 is in contact with the upper and lower surfaces of the case 2, which is one step higher than the step on which the shutter plate 9 is mounted. Then, insert the shutter plate 9 into the guide grooves 18, 18.
When the shutter plate 9 is moved in the direction, the guide pieces 14, 14 of the shutter plate 9 fit into the guide grooves 18, 18, and
The left end 9a of the shutter plate 9 in FIG. 2 falls into the stepped part of the case 2, and the shutter plate 9, which had been pushed open, returns to its original state, and the guide pieces 14, 14 and the guide grooves 18, 18 engage with each other. This condition is maintained and the shutter plate 9 is prevented from falling off. When the shutter plate 9 is attached to the case 2 as described above, the L-shaped bent portion 11b at the other end of the spring 11 is latched onto the fold-down piece 12 of the shutter plate 9, and the shutter plate 9 is attached to the spring 11. Due to the elasticity of the shutter plate 9, the window hole 10 of the shutter plate 9 and the opening 8 of the case 2 are biased so as to slide in a direction that is different from each other and blocks the opening 8. The shutter plate 9 resists the biasing force of the spring 11.
When the spring 11 is slid, the spring 11 engages with the folding piece 13 of the shutter plate 9, and the bent portion 11 of the spring 11
b is designed to prevent it from coming off the fold-down piece 12. The shutter plate 9 is formed with a cutout engagement portion 30 that is to be engaged with a pin 89 of an opening/closing member 81, which will be described later.

There are square recesses 2 in the corners of the hard case 2.
1 and 22, and circular holes 23 and 23 into which pins for positioning the cassette 1 are inserted are provided within the range of these recesses. The case 2 is also provided with recesses 24 and 25 on the end surface on the side where the shutter plate 9 is attached for detecting incorrect insertion of the cassette 1. The case 2 is provided with write-preventing holes 26, 26 at the edge opposite to the mounting portion of the shutter plate 9. These holes 26,
There are recesses 28, 28 on the side of the case 2 where the 26 is formed.
are provided in the recesses 28, 28, the holes 26,
writing prevention operation piece 29 for opening and closing 26;
29 is built-in.

Next, a cassette loading device for loading the magnetic disk cassette 1 constructed as described above will be explained. 4 to 7, the cassette loading device mainly consists of a chassis 42, a cassette holder 40 and an upper case 41 rotatably supported by the chassis 42, and a pressing member 66 provided on the cassette holder 40. Become. Chassis 42 has
It is equipped with a support part 44 having a pin 43 that serves as a pivot for the upper case 41, a support part 46 that has a pin 45 that serves as a pivot for the holder 44, and pins 47 and 48 for positioning the cassette 1. Chassis 4
A spindle hub 105 protrudes from the top surface of 2. As shown in FIG.
1 has a top plate 52 and side plates 50 and 51 formed by bending both side edges of the top plate. Side plate 5
At the base end of 0, 51, there is an engaging portion 5 that engages with the pin 43.
3 is formed, and the engaging portion is rotatably supported by a pin 43. The upper case 41 is urged to rotate counterclockwise in FIG. 4, that is, in a direction away from the chassis 42, by a spring 55 applied between the case and the locking portion 54 of the chassis 42. As shown, the engaging portion 56 formed on the side plate 50 comes into contact with the protrusion 57 of the chassis 42, thereby delimiting the rotational limit due to the biasing force and maintaining the rotational mode. It is becoming more and more common. As shown in FIG. 5, the upper surface plate 52 of the upper case 41 has a bent portion 58 for vertically moving the upper pad at a position near the base end.
and a pressing part 59 for pressing the disk hub.
Lifting parts 60, 60 for lifting the holder 40 are formed at a position near the free end, and a notched stepped part 61 is formed in the side plate 51.

As shown in FIG. 6, the holder 40 is
The cassette 1 is formed to be able to receive the cassette 1 by left and right upper plates 65, 65, side plates 62, 63 following these upper plates, and a lower plate 93 that connects these side plates together. Pin holes 64, 64 into which the pins 45, 45 as support shafts are inserted are formed at the base ends of the side plates 62, 63. An appropriate number of protrusions 67 are formed on the top plate 65, and these protrusions 67
The holes 68 of the presser member 66 are fitted and caulked, and the presser member 66 is then fixed to the top plate 65. The holding member 66 has a pair of bent portions 69, 69 extending from the front end toward the rear end.
A hub presser piece 71 is formed between the bent portions 69 and 69 and has a recessed portion 70 whose free end protrudes downward. Hub holding piece 71
The base of the connecting piece 72 connects the bent portions 69, 6 on both sides.
9, and when the bent portions 69, 69 bend, the hub presser 71 also bends. Arm-shaped side pieces 73 and 77 are integrally formed on the left and right sides of the holding member 66, and the tip 74 of the left side piece 73 in FIG. A bent portion 75 is formed.
The bent piece 75 is located in a notch 76 formed in the side plate 62 of the holder 40. Further, the tip end 78 of the right side piece 77 is also slightly bent downward. However, the side piece 77 is slightly shorter than the other side piece 73, and the side piece 77 has an outwardly protruding piece 7.
9 is formed. At the bases of the side pieces 73, 77, spring locking pieces 80, 80 are formed that face inward from each other. The holding part 66 also has a side piece 7.
3, 77, the shutter plate 9
Holding parts 82, 82 that hold opening/closing members 81, 81 for opening and closing are integrally formed. Holding part 8
2, 82 are the base parts 83, 8 of the opening/closing members 81, 81.
3, cam parts 85, 85 to serve as guides when rotating the opening/closing members 81, 81, and steps for regulating the rotational position of the opening/closing members 81, 81. shaped regulating portions 86, 86
have. The opening/closing members 81 , 81 have pins 87 , 87 that serve as rotation axes, and a projecting piece 8 that is located below the holding portion 82 and serves as a guide for the rotation of the opening/closing member 81 .
8, 88, and pins 89, 89 for engaging the recess 30 of the shutter plate 9 and sliding the shutter plate 9.
have. The opening/closing members 81 , 81 are provided with their pins 87 , 87 inserted into the holes 91 of the holder 40 so as to be rotatable around the pins 87 , 87 . Due to the elasticity of the springs 90, 90 applied between them, the opening/closing member 81 on the left side in FIG.
The opening/closing member 81 on the right side is rotated counterclockwise and the side surface of each opening/closing member 81, 81 is pressed against the pressing member 6.
By coming into contact with the regulating portions 86, 86 of No. 6, rotation by the above-mentioned urging force is restricted. A pressing portion 84 of a pressing member 66 fixed to the holder 40 by a protrusion 67 is located above the base portions 83, 83 of the opening/closing members 81, 81 to prevent the opening/closing members 81, 81 from coming off. The opening/closing members 81, 81 are connected to the holding parts 82, 8 of the pressing member 66.
The opening/closing members 81, 81 are reliably held since the projecting pieces 88, 88 are located below the holding parts 82, 82. A cassette insertion opening 92 is formed at the free end of the holder 40, and a bottom plate 93 of the holder 40
A notch 94 into which the spindle hub 105 and head carriage fit is provided in the center of the head. In the back left side of the holder 40 in FIG.
A protrusion 95 is provided to prevent incorrect insertion of the cassette. A bent portion 96 is provided at the rear end of the holder 40, with which the rear end surface of the cassette 1 comes into contact to regulate the position of the cassette 1.

Next, the operation of the above-mentioned cassette loading device is shown in FIG.
This will be explained with reference to FIGS. 7 to 9. 7th
In the figure, the disk cassette 1 is attached to the shutter plate 9.
When inserted from the insertion opening 92 with the side facing toward the back, the pin 89 of the opening/closing member 81 on the left side in the figure enters the notch engaging portion 30 of the shutter plate 9, and the Since the pin 89 is pushed by the wall surface of the (see Figure 1), the left opening/closing member 81 rotates counterclockwise. This opening/closing member 8
1, the pin 89 moves to the left while drawing an arc, so the shutter plate 9 is also moved to the left, and the window hole 10 of the shutter plate 9 and the opening 8 of the case 2 are matches. That is, the shutter is opened. At this time, the pin 89 of the opening/closing member 81 on the right side is pushed by the wall surface of the notch 20 of the case 2 (see FIG. Since the shutter plate 9 is not provided with the notch engaging portion,
The above movement of the shutter plate 9 is not affected in any way.
In this way, while moving the shutter plate 9 and opening the shutter, the cassette 1 is still pushed in.
The recess 24 of the case 2 fits into the protrusion 95 of the holder 40, and the end surface of the case 2 comes into contact with the bent part 96 of the holder 40, reaching the insertion limit of the cassette 1. In addition, when the cassette 1 is inserted, the tip 74 of the side piece 73 of the holding member 66 is pushed up by the case 2, but when the cassette 1 is inserted to the limit position, the tip 74 enters the recess 21 of the case 2. Then, the cassette 1 is restrained in the inserted state.

The cassette 1 is loaded in this manner, and information signals are recorded and reproduced on the disk 3 by rotating the upper case 41 from the state shown in FIG. 4 to the state shown in FIG. . A pair of engagement pieces 97, 97 are provided at the front end of the holding member 66.
are provided, and when the engaging pieces 97, 97 are hooked on the bent protrusions 60, 60 of the upper case 41, the upper case 41 is rotated above the chassis 42 as shown in FIG. Holder 40 when
is also rotated above the chassis 42. but,
When the upper case 41 is pushed down and rotated, the holder 40 also rotates downward. Thus upper case 4
1 is placed over a lower case (not shown) and closed, the state is maintained by the action of a locking mechanism (not shown).

FIG. 8 shows a state in which the upper case 41 has been pushed down to reach the recording/reproducing position, but the holder 4
Since the pivot positions of the upper case 41 and the upper case 41 are different,
Before reaching the state shown in FIG. 8, the bent portion 69 of the pressing member 66 is
69 is pushed and deflected downward, and the holder 40 is urged downward. Since the hub holding piece 71 is connected to the base of the bent parts 69, 69 by the connecting piece 72, when the bent parts 69, 69 bend downward, the hub holding piece 71 also bends downward.
At the recording/reproducing position as shown in Fig. 8, the hub holding piece 7
The protrusion 5 of the disk hub 4 is pushed by the downwardly protruding recess 70 at the tip of the disk hub 4, and the disk hub 4 is securely attached to the spindle hub 105. When the holder 40 is pushed down by the upper case 41, the holding member 6 is pressed down before the holder 40 reaches the rotation limit position.
When the bent portion 75 of No. 6 comes into contact with the chassis 42 and the holder 40 is further pushed down, the tip portion 74 of the side piece 73 of the holding member 66 is lifted. As a result, the tip 74 escapes from the recess 21 of the case 2, the cassette 1 is no longer restrained from the holder 40, and the cassette 1 is moved to the positioning pin 4 on the chassis.
7 and 48, it is positioned at the normal position.
Note that the pin 47 is inserted into the recess 2 of the case 2 of the cassette 1.
1, and the tip of the pin 47 is in contact with the bottom of case 2.
The pin 48 enters the circular hole 23 of the cassette 1, and comes into contact with the lower surface of the case 2 to regulate the front-rear and up-down positions of the cassette 1. Since the length of one side piece 77 of the holding member 66 is slightly shorter than the length of the other side piece 73, when the position of the cassette 1 is regulated as described above, the position of the cassette 1 is regulated as shown in FIG. However, the tip end 78 of the side piece 77 has not yet come into engagement with the end surface of the recess 21 of the case 2. Also, by pushing down the upper case 41, the bent portion 58 is lowered,
Accordingly, the upper carriage holding the upper magnetic head descends to assume the recording/reproducing position. In FIG. 9, reference numeral 100 is a DC rotary motor, which is attached to the chassis to rotate the disk 3 and move the magnetic head. 101 is a pulley of the motor.

To eject the loaded cassette 1, the lock mechanism (not shown) is released and the upper case 41 and cassette holder 40 are rotated by the elasticity of the spring 55 as shown in FIG. conduct. When the upper case 41 rotates counterclockwise due to the elasticity of the spring 55, the engaging piece 97 of the pressing member 66 fixed to the holder 40 engages the upper case 4.
1, the tip of the pin 47 slips out of the positioning hole of the cassette 1, and the cassette 1 is pushed outward based on the elasticity of the springs 90, 90 of the opening/closing members 81, 81. try However, the side piece 7 of the holding member 66
The tip end 78 of the cassette 1 hits the inner wall of the recess 21 of the cassette 1 and temporarily restrains the cassette 1. When the upper case 41 further rotates, the cutout step 61 provided in the upper case 41 pushes up the protruding piece 79 of the holding member 61, disengaging the tip 78 from the recess 21 of the cassette 1, and springs the cassette 1. It is pushed outward by the rotation biasing force of the opening/closing member 81 based on the elasticity of the opening/closing member 90. As the opening/closing member 81 returns to rotation, the shutter plate 9 also returns to its original position, closing the shutter.

Next, the rotational drive mechanism of the disk 3 and the movement mechanism of the magnetic head will be explained. In FIG. 10, a shaft support 108 is fitted and fixed on the lower surface side of the chassis 42, and the shaft portion of the spindle hub 105 is rotatably supported by the inner periphery of the bearing 108. A boss of a small-diameter gear 104 is fitted and fixed to the shaft portion of the spindle hub 105 that protrudes from the lower end of the bearing 108.
3 are fitted and fixed. The outer periphery of the rotating body 103 is a pulley portion, and the belt 102 is hung on this pulley portion. The belt 102 is also looped around the pulley 101 of the motor 100, and as long as the motor 100 is driven to rotate, the rotating body 10
3, gear 104, and spindle hub 105 are configured to be rotationally driven as one unit. A hole 106 is formed in the center of the spindle hub 105 for receiving the lower protrusion 5 provided in the center of the disk hub 4.
A protrusion 107 for engaging with the engagement protrusion 7 of the disk hub 4 to rotationally drive the disk 3 is formed on the disk. The rotating body 103 and the small diameter gear 104 constitute a continuous rotating body.

A cam body 109 for moving the head carriage is rotatably fitted on the outer periphery of the bearing 108. As shown in FIGS. 11 and 21, a cam groove 110 is formed on the upper surface of the cam body 109 for moving the head carriage. The cam groove 110 is formed in 17 stages by dividing the cam body 109 into two half-circumferentially, and the distance from the center of each half changes stepwise.
A mesial portion of the cam groove 110 formed on one half circumference and a distal portion of the cam groove 110 formed on the other half circumference are connected to each other by a connecting groove 111. FIG. 12 shows how the cam groove 110 and the connecting groove 111 change in distance from the center. On the other hand, on the outer periphery of the lower surface of the cam body 109, locking recesses 112 are formed as engaging portions corresponding to each step position of the cam groove 110 and having the same number as the number of steps.
Further, an annular projection 114 is formed at an intermediate portion between the center and the outer periphery of the cam body 109, and a downward protruding pin 113 is formed in a part of the annular projection 114. As shown in FIGS. 10 and 14 (B-B plan view in FIG. 10), a gear 115 as a connecting rotor is rotatably fitted into the pin 113, and the outer periphery of the annular protrusion 114 is rotated. An annular gear 116 as a driven rotating body is rotatably fitted in the portion. The gear 115 meshes with both the inward gear 119 formed on the inner periphery of the annular gear 116 and the small diameter gear 104 . As shown in FIG. 13, ratchet-like engaging gears 118 are formed on the outer periphery of the annular gear 116, corresponding to each stage of the cam groove 110. As shown in FIGS. 15, 20 and 21, the cam body 109
An engagement groove 134 corresponding to the engagement recess 112 is formed at a position on the outer periphery and below the engagement recess 112 . Cam body 1
09 is the direction of arrow L, the rear end of the engagement groove 134 is aligned with the inclined surface 1 with respect to this rotation direction.
34a and the lower surface 133 of the engagement groove 134 forming part.
connected to. Cam groove 110 of cam body 109
It is also possible for this to be a raised cam edge.

In FIGS. 14 and 15, the cam body 109
A bell crank-shaped control lever 120 is rotatably provided on the side of the shaft 123 about a shaft 123. A permanent magnet 124 is fixed to the edge of one arm of the lever 120, and the iron core 1 of the magnet 124 and the electromagnet 125
26, the lever 120 is urged to rotate counterclockwise in FIG.
A hook-shaped end 121 of one arm of the cam body 109 enters and engages with the locking recess 112 of the cam body 109. In contrast, the other hooked arm end 122 of the lever 120
is opposed to the engagement gear 118 on the outer periphery of the annular gear 116, but is normally spaced apart from the engagement gear 118. Hooked arm end 121 of lever 120
The formed arm has elasticity in the vertical direction,
When the arm end portion 121 is engaged with the locking recess 112 of the cam body 109, the arm is forcibly bent, and the lower surface 133 of the engaging groove 134 formed in the shape of an eave is formed. They come into contact.

FIG. 15 shows the configuration of the electromagnet 125. The electromagnet 125 includes a case body 127, a coil 132,
A coil 132 is fitted into the space between the coil attachment protrusion 128 at the center of the case body 127 and a cylindrical part surrounding it, and is connected to the center hole 130 of the coil attachment protrusion 128. A horseshoe-shaped iron core 126 is fitted and fixed into a hole 131 provided on the side. Hook-shaped attachment parts 129 are formed on both sides of the case body 127, and the electromagnet 125 is attached to the chassis by the attachment parts 129, and the iron core 126 faces the permanent magnet 124.

Next, the operation of the cam body 109 will be explained with reference to FIG. Together with the rotating body 103 (see FIG. 10), the small diameter gear 104 is driven to rotate in the direction of arrow H, and the gear 115 is driven to rotate in the direction of arrow I. Here, since one arm end 121 of the control lever 120 normally enters and engages with the locking recess 112 of the cam body 109, rotation of the cam body 109 is prevented, and the other arm end 121 of the control lever 120 Since the arm end 122 is separated from the engagement gear 118 of the annular gear 116 and the annular gear 116 is free, the gear 1
15 rotates the annular gear 116 in the direction of arrow J via the inward gear 119. That is,
Normally, the annular gear 116 only rotates continuously, the cam body 109 does not rotate, and the position of the head carriage does not change.

To change the position of the head carriage, the coil 132 of the electromagnet 125 is energized so that the iron core 126 repels the permanent magnet 124. As a result, the control lever 120 rotates clockwise in FIG.
is removed from the locking recess 112 of the lever 120, and the other arm end 122 of the lever 120 is attached to the engagement gear 1 of the annular gear 116.
18, the cam body 109 becomes rotatable, while the annular gear 116 is prevented from rotating. Therefore, as the gear 115 is rotationally driven in the direction of the arrow I, the downward protruding pin 113 of the cam body 109 is moved in the direction of the arrow K, and the cam body 109 is rotationally driven in the direction of the arrow L. When the cam body 109 rotates, the position of a guide pin 159 (described later) fitted in the cam groove 110 changes to the position of the cam body 1.
09 in the radial direction, and the head carriage also moves accordingly.

Here, assume that the coil 132 of the electromagnet 125 is momentarily energized. After the control lever 120 rotates clockwise in FIG. 14, it immediately attempts to return to its original position. However, lever 120
The arm on which the hooked end 121 is formed bends downward in FIG. When the lever 120 rotates, the hooked arm end 121 is caught in the engagement groove 134 provided on the outer periphery of the cam body 109, and the lever 120 is prevented from returning. When the lever 120 is prevented from returning, the annular gear 116 continues to be locked by the other arm end 122 of the lever 120, and the cam body 109 attempts to rotate in the direction of arrow L. This cam body 109
As shown in FIG. 20, the arm end 121 of the lever 120 is pushed down onto the inclined surface 134a of the engagement groove 134, and when it reaches the same level as the lower surface 133, it is removed from the engagement groove 134. It enters the locking recess 112 and the rotation of the cam body 109 is prevented again. In this way, the electromagnet 125
When is momentarily excited, the cam body 109 is intermittently rotated by one tooth, and the head carriage is moved by one track.

The components including the control lever 120, permanent magnet 124, electromagnet 125, etc. constitute head movement control means.

In FIGS. 16 to 19, the head carriage supporting the magnetic head is the upper carriage 1.
50 and a lower carriage 151 as main bodies.
A magnetic head 154 is attached to the head attachment portion 152 of the lower carriage 151 via a gimbal plate 153.
is supported so as to be swingable within a predetermined range. Partially cylindrical pin receiving parts 155, 156 are formed on one side of the lower carriage 151, and when the carriage is attached to the chassis, the pin receiving parts are attached to the support pins 160, 160 fixed to the chassis. The carriage 151 is supported by the contacts 155 and 156 coming into contact with each other from above. The other side edge of the carriage 151 is also connected to the pin 16.
1. A cut-and-raised portion 157 is formed on the carriage 151.
The entire carriage is urged downward and in the radial direction of the disk by the elasticity of a spring 162 applied between the cut and raised portion 157 and the chassis.
The carriage 151 has a flat portion 158 against which a pin (not shown) fixed to the chassis is lightly pressed from above to prevent the entire carriage from floating up. A guide pin 159 is provided at the distal end of the carriage 151, and this pin 159 engages with the cam groove 110 to move the head carriage 151. The upper carriage 150 is attached to the carriage 151.
A cut and raised portion 163 for attachment is formed, and a screw hole 164 is formed in this cut and raised portion 163. A screw hole 169 passing through a hole 166 of a leaf spring 165 and a hole 168 of a push-down spring 167 for pushing down the carriage 150 is screwed into this screw hole 164, so that the push-down spring 1
67 and a leaf spring 165 are fixed to the cut and raised portion 163 of the carriage 151. Also, leaf spring 1
The bent piece 170 of 65 is in contact with the end surface 171 of the cut-and-raised portion 163, and the push-down spring 167
The bent piece 172 presses the bent piece 170, and the pair of locking pieces 173 formed by bending the push-down spring 167 presses the engaging portion 175 of the slot 174 of the leaf spring 165, so that the leaf spring 1
65 is securely attached to the cut and raised portion 163.

Two pins 177 are fixed to the base 176 of the upper carriage 150, and the carriage 150 is attached to the leaf spring 165 by inserting these pins 177 into holes 178 of the leaf spring 165 and tightening them. A bending piece 179 is provided at the intermediate portion of the carriage 150, and this bending piece 179 is adapted to engage with the bending part 58 of the upper case 41 mentioned above, so that the upper case 41 cannot be raised. and the bending part 179 is lifted by the bending part 58,
Carriage 150 is adapted to be brought to a raised position. A pad attachment portion 180 is formed at the free end of the carriage 150. As shown in FIG. 18, the pad attachment portion 180 has a shallow recess 181 formed on the lower surface side, and a gimbal plate 182 is fixed to this recess 181. A window hole is formed in the pad attachment portion 180, and a center plate portion 183 is formed so as to straddle the center of this window hole. A recess 184 is formed in the center of the center plate 183, and a lower end 185 of the recess 184 is connected to the pad 186 via the gimbal plate 182.
It is designed to hold down the center of the Padded 1
89 is made of the same material as the magnetic head 154, for example. The pad 186 is capable of gimbaling using the lower end of the recess 184 as a fulcrum. For double-sided recording method, pad 1
A magnetic head is attached in place of 86. The tip end 187 of the push-down spring 167 presses down the recess 184 of the pad attachment part 180 from above, urging the carriage 150 toward the carriage 151.

As shown in FIG. 7, when the cassette 1 is not inserted into the holder 40 to a predetermined position, the pin 8, which is one end of the opening/closing members 81, 81,
The mounting portions 9 and 89 are attached to the carriage 15 by the rotation biasing force of the opening and closing members 81 and 81 caused by the springs 90 and 90.
0, and as shown in FIG. 9,
When the cassette 1 is inserted into the holder 40 to a predetermined position, the opening/closing members 81, 81 are rotated against the urging force, so that one end thereof is separated from a position where it can come into contact with the carriage 150. I'm starting to do that. Therefore, if the cassette 1 is not inserted into the holder 40, the holder 40
Even if you move the camera to the recording/playback position, the carriage 15
0 is blocked by one end of the opening/closing members 81, 81, and the pad 186 (or magnetic head) cannot come into contact with the disk 3. With the cassette 1 inserted into the holder 40 to a predetermined position, the holder 40 is not recorded. The pad 186 (or magnetic head) can come into contact with the disk 3 only after it is moved to the playback position. With this configuration, even if the disk cassette is moved to the recording/reproducing position without being inserted into the holder, the magnetic head and pad (or magnetic head) will not come into contact with each other.
Furthermore, the magnetic heads will not be attracted to each other, and there will be no fear of damaging the head support mechanism or the like in an attempt to forcibly separate the magnetic heads that have been attracted to each other.

In FIGS. 14 and 16, the cam body 109
A head position detection lever 135 is attached to the side of the shaft 14.
It is rotatably supported around 3. A pin 139 is fixed to the free end of the detection lever 135, and a switch contact piece 140 is pressed against the pin 139, and the spring force of the switch contact piece 140 causes the lever 135 to have its hook-shaped free end 137. Cam body 1
It is urged to rotate in the direction of contacting the locking recess 112 of No. 09. The free end 137 of the lever 135 is
The guide pin 159 of the head carriage is in the cam groove 1.
10, when the magnetic head 154 is in sliding contact with the first track on the outermost circumference of the disk 3, it engages with the locking recess 112a corresponding to the first track. . This locking recess 112a is a recess 136 for detecting return to original position.
are formed continuously. The above-mentioned locking recess 11
2a is formed to the same depth as the other locking recesses 112, but the original position return detection recess 136 is formed deeper than the recess 112. When the free end 137 of the detection lever 135 is engaged with the locking recess 112, 112a, the switch contact pieces 140 are connected to the switch contact pieces 14 on both sides thereof.
1,142, and when the free end 137 of the lever 135 is depressed into the detection recess 136, the contact piece 140 contacts the contact piece 142 and the cam body 10
9 is in the original position, and the free end 137 of the lever 135 locks the protrusion 13 between the locking recesses 112.
8, the contact piece 140 comes into contact with the contact piece 141.

In FIG. 16, the guide pin 159 is located at the outermost position of the cam groove 110, and the head position detection lever 135
shows a state in which the locking recess 112a is located at the position corresponding to the first track next to the home position return detection recess 136. From this state, the cam body 109 is intermittently driven as described above, and its locking recess 11
It is assumed that the protrusion 138 between the two parts can be rotated one tooth at a time. Each time the cam body 109 rotates, the guide pin 159 shifts one step to the mesial cam edge of the cam edge of the cam groove 110, and the sliding position of the magnetic head 154 with respect to the track of the disk 3 shifts to the inner periphery. You will be shifted one step at a time to the side track. Also, each time the cam body 109 rotates by one tooth of the protrusion 138, the switch contact pieces 140, 14
When the magnetic head 154 makes contact, a signal is emitted, and by counting this signal, it is possible to detect which track the magnetic head 154 is in sliding contact with. Further, when the free end 137 of the detection lever 135 is engaged with the recess 136 for detecting return to original position, the switch contact pieces 140, 142
contacts and the signal emitted by this causes
It can be detected that the cam body 109 is at the reference position, that is, that the guide pin 159 is engaged with the connecting groove 111 that connects the two cam grooves 110. In this way, the magnetic head 154
Since the sliding contact position of contact piece 14 is always detected,
The magnetic head 154 can be brought into sliding contact with a desired track by counting the signals caused by the contact between the contact piece 141 and the contact piece 141, and by detecting the signal caused by the contact between the contact piece 140 and the contact piece 142.

In the illustrated example, the magnetic disk cassette 1
is a single-sided type cassette, and recesses 24 and 25 are provided at the top and bottom of the cassette 1 to prevent incorrect insertion, and the cassette can be used by turning it upside down with respect to the magnetic head 154 provided at the bottom. In addition, it is possible to prevent incorrect insertion even when the device is turned upside down.
However, if the recess 25 on one side of the cassette 1 is eliminated so that the cassette 1 can only be inserted with one side facing, and the pad 186 is replaced with a magnetic head, the cassette 1 and disk device can be converted into a double-sided type. It can be used as
Further, the number of steps in the cam grooves 110 of the cam body 109 can be increased or decreased as appropriate, and one rotation of the cam body moves the magnetic head from the track position on the outermost circumference of the disk to the track position on the innermost circumference. You can also do it like this. Furthermore, since the gist of the present invention is a mechanism for moving the head in the radial direction of the disk using the rotational motion of a continuous rotating body, the type of cassette and the configuration of the cassette loading mechanism are limited to those shown in the drawings. It is not a set of rules and can be changed arbitrarily. Further, the design of the magnetic head moving mechanism may be freely changed without departing from the technical matters set forth in the claims.

According to the present invention, the present invention includes a continuous rotating body, a connecting rotating body rotationally driven by the continuous rotating body, and a driven rotating body rotationally driven by the connecting rotating body, and The head movement control means includes a cam body having a cam portion for moving the head whose diameter changes over time, and a head movement control means that can engage with the cam body, and this head movement control means controls the movement of the cam body when the head is not moved. The rotation is regulated and the driven rotating body is kept rotating, and when the head is moved, the rotation regulation of the cam body is released and the rotation of the driven rotating body is regulated, so that the continuous rotation of the continuous rotating body is controlled. It is possible to convert rotational force into intermittent linear movement of the head, and there is no need to use an expensive motor that moves intermittently as a motor for moving the head.
The head can also be moved using the rotational force of the motor that rotates the disk.

[Brief explanation of drawings]

FIG. 1 is a plan view showing an example of a magnetic disk cassette that can be used in the present invention, FIG. 2 is an exploded perspective view of the same cassette, FIG. 3 is a partially sectional side view of the same cassette, and FIG. 4 is a magnetic disk cassette according to the present invention. Fig. 5 is a plan view showing the upper cover in the above embodiment, Fig. 6 is an exploded perspective view showing the cassette holder part in the above embodiment, and Fig. 7 is a side view showing the above embodiment. 8 is a side view showing different operating modes of the above embodiment according to FIG. 4, FIG. 9 is a plan view showing different operating modes of the above embodiment according to FIG. 7, and FIG. 11 is a plan view of the cam body, FIG. 12 is a developed view of the cam edge of the cam body, and FIG. FIG. 13 is a plan view showing the annular gear in the above embodiment, FIG. 14 is a partially sectional plan view showing the rotation converting means in the above embodiment, and FIG. 16 is a plan view of the magnetic head moving mechanism in the above embodiment, FIG. 17 is an exploded perspective view of the magnetic head support mechanism in the above embodiment, and FIG. 18 is an exploded perspective view of the control mechanism in the above embodiment. 17 is a sectional view taken along line A-A, FIG. 19 is a plan view of the magnetic head support mechanism portion, and FIG.
The figure is an enlarged side view of a part of the cam body, and FIG. 21 is a longitudinal sectional view of the same cam body. 103...Rotating body as a continuous rotating body, 104...
Gear as a continuous rotating body, 109...Cam body, 11
0... Cam groove as a cam part, 112... Locking recess as an engaging part, 115... Gear as a connecting rotating body, 116... Annular gear as a driven rotating body, 12
0... Control lever forming part of the head movement control means, 124... Permanent magnet forming part of the head movement control means, 125... Electromagnet forming part of the head movement control means.

Claims (1)

[Claims] 1. A continuous rotating body, a connecting rotating body 115 that is rotationally driven by this continuous rotating body, and a driven rotating body 116 that is rotationally driven by this connecting rotating body.
and a cam body which rotatably holds the coupling rotary body and has a cam part for moving the head whose diameter changes in stages and the same number of engaging parts 112 as the number of stages, and an engagement of this cam body. The head movement control means is provided with a head movement control means that can engage with the coupling part, and the head movement control means regulates the rotation of the cam body when the head is not moved, and also keeps the driven rotary body rotating and controls the movement of the head. A disk-shaped recording/reproducing device configured to sometimes release the restriction on the rotation of the cam body and restrict the rotation of the driven rotating body.