JPH0142843Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a magnetic disk drive device for recording or reproducing signals using a micropropy disk or a similar magnetic disk cartridge.

Conventional technology Rigid case with a diameter of 86 mm (approximately 3.5 inches)
Magnetic disk cartridges (microfloppy disks) containing magnetic disks are already known. Furthermore, a disk drive device that uses this cartridge to record or reproduce signals has already been proposed. (For example, Japanese Patent Application No. 58-225569 [Japanese Unexamined Patent Publication No. 117464-1989]).

The above-described magnetic disk cartridge 1 is constructed by housing a magnetic disk 2 having a diameter of 86 mm in a rigid synthetic resin case 3, as shown in FIGS. 3A and 3B and FIG. 4. Head insertion openings 6 are provided on both the front surface 4 and back surface 5 of the case 3.
7, and these openings 6, 7 are closed by a sliding shutter 8 when not in use.
The shutter 8 is formed in a U-shape so as to extend from the front surface 4 to the back surface 5, and is engaged with a groove 71 provided on the back surface 5 with an engaging piece 72, as shown in FIG. slide along. A torsion spring 70 is housed in the case 3 in order to bias the shutter 8 in the right direction (closing direction) as shown in FIG.
Pressing 3. The shutter 8 is moved by its biasing spring 7.
A first recess 9 is provided in one side 3a of the case 3 in order to make it easier to push the case 3 to the left in FIGS. A second recess 9a is provided corresponding to the second recess 9a. Therefore, the edge 8a of the shutter 8 protrudes from one side 3a of the case 3 to some extent. The magnetic disk 2 consists of a magnetic sheet portion 2a and a metal hub 2b attached to the center thereof. Hub 2b exposed from opening 10 on back surface 5 of case 3
is provided with a spindle insertion hole 2c and a positioning and driving pin insertion hole 2d.

The conventional shutter 8 opening mechanism includes a rotating plate disposed in a holder for inserting the cartridge 1, a single pin provided at the tip of the rotating plate, and biasing the rotating plate in the cartridge ejecting direction. By providing a spring and inserting the cartridge 1, the pin is pressed and the rotating plate is rotated, and the pin presses the edge 8a of the shutter 8 to the left in accordance with the displacement of the pin. It is configured to open.

Problems to be Solved by the Invention Even with the conventional shutter opening mechanism as described above, the shutter 8 can be opened normally in many cases. However, if there are burrs (small protrusions) that occur when molding the synthetic resin case 3 in the second recess 9a of the one side surface 3a of the case 3, the shutter 8
normal opening operation becomes impossible. That is, when the shutter release pin presses the edge 8a of the shutter 8 and reaches the recess 9a, the shutter 8 is almost completely opened, but almost in synchronization with the opening of the shutter, the cartridge 1 and the holder move toward the disk rotating body. When descending in the direction, the release pin may ride on the burr. Since the case 3 is formed by butting the upper half and the lower half, a burr is generated approximately in the middle of one side 3a, and the tip of the pin is closer to the burr than the surface of the case 3, so it rides on the burr. there is a possibility. At this time, the pin follows the holder and descends, but since the pin is placed at the tip of the flexible rotating plate, there is a delay in the displacement of the pin due to the flexibility, and the pin ends up on the burr. Sometimes. If the rotary plate has perfect rigidity and the pin is configured to be displaced simultaneously with the holder, the phenomenon of the pin riding on the burr will not occur. However, such a configuration is disadvantageous in terms of cost.
Even if the pin rides on a small protrusion such as a burr, the shutter 8 is normally maintained open. However, the tip of the pin causes a phenomenon in which the case 3 is pushed down, and the frictional force between the liner inside the case 3 and the disk 2 inside increases, making it difficult for the disk 2 to rotate smoothly inside the case 3. becomes impossible. SUMMARY OF THE INVENTION An object of the present invention is to provide a magnetic disk drive device that can prevent the shutter release mechanism from operating erroneously.

Means for Solving the Problems The present invention for achieving the above object will be described with reference to the reference numerals in the drawings showing the embodiments for ease of understanding.A magnetic disk 2 is housed in a case 3, The case 3 is provided with a head insertion opening for bringing the magnetic head into contact with the disk 2, and an opening 10 for exposing the central hub 2b of the disk, and selectively covers the head insertion opening. A shutter 8 is provided, and the shutter 8 is engaged with the case 3 so as to linearly slide along one side of the case 3, and extends in a U-shape from the front surface to the back surface of the case 3. This is an apparatus for recording or reproducing information signals using a magnetic disk cartridge 1 which is formed with a shutter biasing spring 70 for always biasing the shutter in the closing direction, and a hub of the disk 2. 2b; a magnetic head that contacts the disk 2 through the head insertion opening to record or reproduce a signal; It is formed to receive the cartridge 1 inserted from a direction perpendicular to the axial direction of the body 17, and the disk 2 is connected to the rotating body 1.
The disc 2 is configured to move in the axial direction of the rotary body 17 in order to guide the disc 2 from a disengaged position where the disc 2 is kept in a disengaged state with the rotary body 7 to an engagement position where the disc 2 is engaged with the rotary body 17. Cartridge holder 1
8, a shutter opening rotary plate 43 is provided, and this rotary plate 43 is rotatably attached to the cartridge holder 18, and the rotary plate 43 is rotatably mounted on the cartridge holder 18 in the direction of ejecting the cartridge 1. A rotating plate biasing spring 46 is provided to apply a biasing force to the rotating plate 43, and when the cartridge 1 is inserted into the cartridge holder 18, the rotating plate 43
is pressed by one side 3a of the case 3 so as to be rotated against the spring 46, and the edge 8a of the shutter 8 extending in the insertion direction of the cartridge 1 is rotated against the shutter biasing spring 70. A first protrusion 47 is provided near the tip of the rotary plate 43 and is pressed against one side 3a of the case 3 a little before the insertion of the cartridge 1 into the cartridge holder 18 is completed. The second protrusion 74 that is in contact with the one side surface 3a and is pressed by the one side surface 3a and determines the rotational position of the rotary plate 43 so as to separate the first protrusion 47 from the one side surface 3a
The present invention relates to a magnetic disk drive device characterized in that the second protrusion 74 is located between the spindle 45 of the rotating plate 43 and the first protrusion 47.

Effect Since the second protrusion 74 is provided, the first protrusion 47
is displaced away from one side 3a of the case 3 of the cartridge 1 near the final insertion position of the cartridge 1. Therefore, even if there is an unnecessary protrusion such as a burr near the first protrusion 47, there is almost no possibility that the first protrusion 47 will ride on it. As a result, unnecessary pressing of the cartridge 1 by the first protrusion 47 does not occur, and the disk 2 can be rotated smoothly.

Embodiment Next, a magnetic disk drive device according to an embodiment of the present invention will be described with reference to FIGS. 1 to 16. However, since the disk cartridge 1 used in this disk drive device has already been explained, its explanation will be omitted.

5 to 8 show the magnetic disk drive device with no disk inserted, FIGS. 9 to 12 show the disk inserted, and FIG. 13 schematically shows the head support displacement control mechanism of FIG. 5. 14 schematically shows a pair of magnetic heads in contact with a magnetic disk, FIG. 15 schematically shows the locking mechanism shown in FIG. 5, and FIG. 16 shows the holder shown in FIG. 5. The displacement prevention mechanism is shown. As shown in FIGS. 6 and 14, this disk drive device has one (lower) magnetic head 11 and the other (upper) magnetic head 12 disposed opposite thereto. The head 11 is brought into contact with one side of the disk 2 for recording or reproduction, and the other magnetic head 12 is brought into contact with the other side of the disk 2 for recording or reproduction. One magnetic head 11 is fixedly mounted on a lower carriage 13, and the other magnetic head 12 is mounted on a head support 14. The head support 14 is
It is attached to the carriage 13 by a leaf spring 15, and receives a biasing force in the direction of bringing the magnetic head 12 into contact with the disk 2. head carriage 13
The head moving mechanism 80 of FIG. 14 is composed of a stepping motor and a rotational motion-linear motion conversion mechanism.
is sent in the radial direction of the disk 2 by.

The disk rotation mechanism consists of a disk rotation motor 16 shown in FIG. 6 and a disk rotation body 17 coupled to the motor 16. The rotating body 17 engages with the hub 2b of the disk 2 and rotates while supporting the disk 2, and includes a spindle 17a, a magnet 17b for attracting the hub 2b, and a drive pin 1.
7c. The spindle 17a is shown in FIG. 3B.
is inserted into the hole 2c provided in the hub 2b shown in
The drive pin 17c is inserted into the positioning hole 2d.

Holding the disk cartridge 1, which is inserted from bottom to top in FIG. 5 and from right to left in FIG.
A cartridge holder 18 is provided to guide the cartridge from a non-engaging position (non-rotating position) to an engaging position (rotating position). As is most obvious from FIG. 6, this cartridge holder 18 holds a base 19 on the rear surface 5 side of the cartridge 1, a pair of side surfaces 20 and 21 vertically rising from the base 19, and a front surface 4 of the cartridge 1. The base 19 and the pair of side surfaces 20, 21 are formed by bending a single metal plate into a U-shape. Guide pins 24 and 25 are implanted in the pair of side surfaces 20 and 21, and are inserted into guide holes 26a of a support plate 26 shown in FIG. Since the guide hole 26a extends in the vertical direction in FIG. 8, that is, in the axial direction of the rotating body 17 in FIG.
guide you in this direction.

A cartridge holder moving mechanism for moving the holder 18 in the axial direction of the rotating body 17 is constituted by the slide body 27. Like the holder 18, this slide body 27 is made by bending a metal plate into a U-shaped cross section.
The holder 18 is made up of a central bottom part 28 parallel to the central bottom part 28, and a pair of side parts 29, 30 vertically rising from the central bottom part 28 and arranged parallel to the side parts 20, 21 of the holder 18. A long hole 31 extending in the direction in which the disk cartridge 1 is inserted is provided in the bottom surface 28 of the slide body 27, and a guide pin 3 embedded in the fixed base plate 32 is provided.
3 has been inserted. The slide body 27 is guided by this guide pin 33 and slides in the insertion direction of the cartridge 1. In order to engage the slide body 27 and the holder 18 so that they have a certain relationship,
As shown in FIG. 7, an inclined groove 34 is provided in the side surface 29 of the slide body 27, and
A pin 24 protruding from the slanted groove 34 engages with the slanted groove 34 . Therefore, when the slide body 27 slides to the right in FIG. 7, the pin 24 is pressed downward by the edge of the inclined groove 34, and the holder 18 is moved together with the pin 24 from the position shown in FIG. 7 to the position shown in FIG. Move to position. The springs 35 and 36 shown in FIG.
It deviates downward in the figure. That is, the springs 35 and 36 apply a force to the slide body 27 in the direction of moving the holder 18 to the disk engagement position (rotation position).

A locking mechanism for locking the slide body 27 against the springs 35 and 36 so that the holder 18 is kept in the non-engaging position (non-rotating position) is shown in FIGS.
It consists of a locking lever 37 shown in FIG. 5 and a locking pin 38 protruding from the slide body 27. The locking lever 37 has a recess 39 into which the pin 38 engages, and further has a pressed portion 40 that is pressed by the cartridge 1. Moreover, this lever 37
It is rotatably supported by a shaft 41 implanted in FIG. 2, and is biased counterclockwise in FIGS. 5 and 15 by a torsion spring 42 shown in FIG. When the cartridge 1 is inserted, the pressed portion 40 is pressed, and the lever 37 is moved to the fifth position against the biasing force of the spring 42.
When rotated clockwise in the figure and Figure 15, pin 3
8 and the recess 39 are released, and the slide body 2
7 is released from the locking by the locking lever 37.

In addition to the locking lever 37, this device has a holder displacement prevention mechanism that serves as another locking mechanism. This holder displacement prevention mechanism is shown in FIGS. 5 and 6.
16, a rotary plate 43 has a function of opening the shutter 8 of the cartridge 1 and also has a holder displacement prevention mechanism, and a fixed base plate 3.
2 and a pin 44 protruding from the pin 44. The rotating plate 43 is rotatably supported by a shaft 45 implanted in the holder 18, and is biased counterclockwise by a spring 46 shown in FIG. The rotating plate 43 has a shaft 4
A notch 48 is provided at a position corresponding to the circumference of the shaft 45 with the radius being the distance from the pin 44 to the pin 44 . Since the pin 44 is set to a length such that it almost touches the lower surface of the rotating plate 43 in the non-use state shown in FIGS. 5 and 6, unless the pin 44 enters the notch 48, the rotating plate 43 and the holder 18 is maintained in the position shown in FIGS. 5 and 6.
In addition to the first pin 47 as a first protrusion that has been conventionally provided on the rotating plate 43 made of metal, there is a second protrusion that is newly provided according to the present invention. Two pins 74 are provided. As is clear from FIGS. 1 and 2, the first pin 47 is first pressed against the case 3, and almost simultaneously presses the edge 8a of the shutter 8 to the left in FIG. 2, thereby preventing the cartridge 1 from being inserted. As the shutter advances further, the shutter 8 is almost completely opened by the first pin 47, and then the second pin 47 opens the shutter 8 almost completely.
pin 74 contacts case 1, and case 1 contacts the second pin 74.
1, the rotating plate 43 further rotates clockwise in FIG. 1, and the first pin 47 is moved slightly away from the side surface 3a of the case 3.
Note that the insertion position of the cartridge 1 is the holder 18.
The rotation plate 43 is determined by a stopper 75 provided in the
The rotational position of is also determined accordingly.

The head moving mechanism for bringing the upper head 12 into contact with the disk 2 in conjunction with the slide body 27 includes the head support displacement control mechanism 49 shown in FIGS. 5 and 13 and the head support 14 and spring described above. It consists of 15. The head support 14 is a spring 1
5 biases the head 12 toward the disk 2, but when not in use it is kept in a spaced position against a spring 15 as shown in FIG. To obtain this spaced position, the head support 14 is provided with an arm 50 which is pushed up when not in use.

As is clear from FIGS. 5 and 6 and FIG. 13 schematically showing the head support displacement control mechanism 49, the head support displacement control mechanism 49 includes a first lever 51, which can be called a slide body engagement lever, and a head displacement lever. The first lever 51 and the second lever 52 are engaged to form a cam mechanism. More specifically, the engagement piece 53 is rotatably supported by a shaft 54 implanted in the slide body 27.
3 engages with the first lever 51 while being biased counterclockwise by a spring 55. first lever 5
1 is rotatably supported by a shaft 56 and has an engagement surface 57 that engages with the second lever 52 . The second lever 52 is rotatably supported by a shaft 58 extending in a direction perpendicular to the shaft 56 of the first lever 51. It consists of an engaging part 59 and a second engaging part 60 that protrudes in the same direction as the shaft 58 so as to engage with the arm 50 of the head support 14, and the spring 6
1 is biased clockwise in FIG. The second lever 52 tries to rotate clockwise by the spring 61, but since the first engaging portion 59 is engaged with the first lever 51, the first lever 52
1 limits the rotation angle. On the other hand, since the first lever 51 is engaged with the slide body 27, its rotation angle is limited depending on the position of the slide body 27. As shown in FIG. 5, when the slide body 27 is locked by the locking lever 37 and positioned upward due to the disk not being inserted,
The first lever 51 is rotated clockwise in FIG.
The head support 1 is rotated counterclockwise in the figure.
The arm 50 of 4 is lifted and the head support 1
4 is rotated to the separated position shown in FIG. 6, and the upper head 12 is separated from the lower head 11. On the other hand, when the locking by the locking lever 37 is released and the slide body 27 is displaced downward as shown in FIG.
1 restriction is lifted. As a result, the second lever 52 can be rotated clockwise in FIG. 13 by the spring 61, and the second engaging portion 60 can be rotated to a lower position in FIG. Head support 1
4 is released, and the head support 14 is moved to the 10th position.
It moves to the contact position shown in the figure and FIG. 14 by the force of the spring 15.

As shown in FIG. 5, this device has a braking mechanism 62. This braking mechanism 62 is for buffering operation, and is constructed by providing a rack 63 on the slide body 27, meshing a pinion 64 with the rack 63, and coupling an oil damper 65 to the pinion 64.

Next, the operation of this device will be explained. The cartridge 1 is inserted into the holder 18 in a direction perpendicular to the axial direction of the rotating body 17, that is, to the left in FIG. As shown in FIG. 6, the holder 18 is provided with holding plates 22 and 23, so the cartridge 1 moves forward while being restricted between the holder base 19 and the holding plates 22 and 23. The tip of the case 3 of the cartridge 1 is the rotary plate 4 for opening the shutter.
3, the pin 47 engages with the first pin 47 of the recess 9.
Get into it. When the cartridge 1 continues to be inserted, the rotating plate 43 rotates against the spring 46, and the first
The shutter 8 is pushed leftward by the pin 47, that is, the first protrusion, and the shutter 8 is opened as shown in FIG. Note that since the second pin 74, that is, the second protrusion is provided, the cartridge 1 can be held in place by a stopper 75 provided on the holder 18 shown in FIG.
When inserted close to , the second pin 74 is pressed by the case 3, and the rotating plate 43 further rotates clockwise. As a result, the first pin 47 located at the entrance of the second recess 9a is displaced upward in FIG. 1 and is slightly separated from the case 3. Then, when the cartridge 1 is inserted to a position where it reaches the stopper 75, the final position of the rotating plate 43 is determined. In the final position of the rotary plate 43, the first pin 47 is of course set to engage the edge 8a of the shutter 8. When the shutter 8 is opened, the openings 8b and 8c of the shutter 8 and the opening 6 of the case 3,
7 matches, and disk 2 is exposed. Rotating plate 4
3 rotates as described above, the position of the notch 48 provided here also changes, and as shown in FIG.
4 matches the position of the notch 48, the rotation plate 43 and the holder 18 are released from being blocked, and can be displaced downward.

On the other hand, when the cartridge 1 is inserted, the pressed portion 40 provided on the locking lever 37 is pressed by the cartridge 1, and the locking lever 37 rotates clockwise in FIG. The engagement with the slide body 27 is released, and the slide body 27 can move freely. For this reason, the slide body 27 has springs 35 and 36
It slides downward as shown in Fig. 5 by the force of , and reaches the position shown in Fig. 9. At this time, since the brake mechanism 62 is added to the slide body 27, the slide body 27 moves slowly. When the slide body 27 moves to the right in FIG. 7, the pin 24 of the holder 18 is pressed downward by the inclined groove 34, and the pin 24 is pushed into the guide hole 2 shown in FIG.
6a and is displaced downward, and the holder 18 is also displaced downward. When the holder 18 is displaced downward as shown in FIG. 11, the disk 2 engages with the rotating body 17 and becomes rotatable.

When the holder 18 moves, the cartridge 1 held therein also moves. Moreover, the rotating plate 43 supported by the holder 18 also moves at the same time. At this time, due to the bending of the rotating plate 43, the first pin 47
Even if there is some delay in the downward displacement of the first pin 47, the first pin 47 will not ride on the burr of the second recess 9a. That is, if the second pin 74 were not present, the first pin 47 would also be in the second recess 9a since the rotating plate 43 is biased counterclockwise in FIG.
If there is a delay in the downward movement of the first pin 47, the first pin 47 may ride on a burr or the like and press the case 3 downward with the first pin 47. However, in this embodiment, the second pin 74 is provided at a position close to the shaft 45 and not easily affected by deflection, and at a position not affected by burrs in the second recess 9a. Since the position is determined by the second pin 74, the first pin 47 will not be displaced in the direction of contacting the side surface of the case 3 or its burr, and will not ride on the burr. Therefore, even if there is a burr on the case 3, the pin 47,
74 presses the case 3 downward from above and does not prevent the rotation of the disk 2.

When the slide body 27 moves downward in FIG. 5, the first lever 51 rotates counterclockwise in FIG. 13, and the second lever 52 rotates clockwise.
The position restriction of the head support 14 is released, and the upper head 12 comes into contact with the disk 2. At this time, the head support 14 rotates slowly following the slide body 27 which is braked by the braking mechanism 62 and moves slowly. Note that this timing adjustment is performed by adjusting the engagement relationship between the first lever 51 and the second lever 52.

After loading the cartridge 1 and performing predetermined recording or reproduction, when taking out the cartridge 1, press the eject operation part 27a of the slide body 27 protruding as shown in FIG. Move it upward in Figure 9. As a result, the pin 24 is pushed up by the inclined groove 34 shown in FIG. 11, and the holder 18 is also moved to the position shown in FIG. 7, so that it can be taken out. When the slide body 27 moves upward in FIG. 9 as described above, the locking pin 38 enters the recess 39 as shown in FIG.
The lock is established. Further, since the first lever 51 is rotated clockwise in FIG. 13 by the slide body 27, the head support 14 is pushed up as shown in FIG. 6, and the head 12 is placed in the separated position.

Although the embodiments of the present invention have been described above, the present invention is not limited thereto and can be further modified. For example, the mechanism for moving the holder 18 downward and the mechanism for moving the head 12 may be constructed as disclosed in the specification and drawings of Japanese Patent Application No. 59-46045. Further, it is also applicable to a case where the cartridge 1 and the drive device are of a single-sided recording/reproducing type. In addition, in this case, the heads 11,1
Make one of the two pads.

Effects of the invention As is clear from the above, in addition to the first protrusion for opening the shutter, a second protrusion for determining the final rotational position of the rotary plate is provided, so that the first protrusion It is possible to prevent phenomena such as riding on the burrs of the case.

[Brief explanation of the drawing]

FIG. 1 is a plan view showing a disk cartridge and a shutter release mechanism according to an embodiment of the present invention in a state in which the shutter has been opened, and FIG. Figure 3A
3B is a plan view of the cartridge, FIG. 3B is a bottom view of the cartridge, FIG. 4 is a rear view of the cartridge, FIG. 5 is a plan view showing a magnetic disk drive device according to an embodiment of the present invention, and FIG. 5 is a partially omitted front view of the device, FIG. 7 is a side view partially cut away along the - line in FIG. 5, FIG. 8 is a side view taken along the - line in FIG. 5, and FIG. The figure is a plan view of the device shown in FIG. 5 with a cartridge attached, FIG. 10 is a partially omitted front view of the device shown in FIG. 9, and FIG.
Figure 12 is a side view taken along line XI-XI in Figure 9. Figure 12 is a side view taken along line XII-XII in Figure 9.
3 is a perspective view schematically showing the head support displacement control mechanism of the device in FIG. 1, FIG. 14 is a schematic side view of the head portion of the device in FIG. 1, and FIG. 15 is a schematic side view of the device in FIG. FIG. 16 is a perspective view showing the locking mechanism, and FIG. 16 is a perspective view showing the shutter opening and holder displacement prevention mechanism of FIG. 1. DESCRIPTION OF SYMBOLS 1... Magnetic disk cartridge, 2... Magnetic disk, 3... Case, 11, 12... Magnetic head, 14... Head support, 15... Leaf spring,
16... Motor, 17... Rotating body, 18... Cartridge holder, 43... Rotating plate, 46... Spring, 47... First pin, 74... Second pin.

Claims (1)

[Claims for Utility Model Registration] A magnetic disk 2 is housed in a case 3, and the case 3 has a head insertion opening for bringing the magnetic head into contact with the disk 2, and a central hub 2b of the disk is exposed. A shutter 8 is provided to selectively cover the head insertion opening, and the shutter 8 is engaged with the case 3 so as to slide linearly along one side of the case 3. is formed in a U-shape so as to extend from the front surface to the back surface of the case 3;
This is a device for recording or reproducing information signals using a magnetic disk cartridge 1, which is provided with a shutter biasing spring 70 for always biasing the shutter in the closing direction. a disk rotation mechanism that rotates the disk 2 by having a rotating body 17 mating therewith; a magnetic head that contacts the disk 2 through the head insertion opening to record or reproduce a signal; The disc 2 is moved from the disengaged position to the rotary body 17, which is formed to receive the cartridge 1 inserted from a direction perpendicular to the axial direction, and keeps the disc 2 in a disengaged state from the rotary body 17. a magnetic disk drive device comprising: a cartridge holder 18 configured to move in the axial direction of the rotating body 17 in order to guide the cartridge holder 18 to an engagement position where it engages with the rotating body 17; A rotating plate biasing spring 4 is provided with a plate 43, which is rotatably attached to the cartridge holder 18, and which applies a biasing force to the rotating plate 43 in the direction of ejecting the cartridge 1.
6 is provided, and when the cartridge 1 is inserted into the cartridge holder 18, the rotation plate 43 is pressed by one side 3a of the case 3 so as to rotate against the spring 46, and A first protrusion 47 that presses the edge 8a of the shutter 8 extending in the insertion direction of the cartridge 1 against the shutter biasing spring 70 is provided near the tip of the rotary plate 43, and the cartridge holder 18, the cartridge 1 contacts one side 3a of the case 3, is pressed by the one side 3a, and moves the first protrusion 47 away from the one side 3a. A second protrusion 74 that determines the rotational position of the rotation plate 43 is provided on the rotation plate 43, and this second protrusion 74 is connected to the support shaft 45 of the rotation plate 43 and the first protrusion 47. A magnetic disk drive device characterized by being located between.