JPS647491Y2 - - Google Patents

Description

[Detailed explanation of the idea] Technical field of invention This invention relates to a magnetic recording/reproducing device.

Technical background of the invention and its problems Conventionally, in a magnetic recording/reproducing device called a microfloppy disk drive or the like, a disk-shaped magnetic medium is rotated, and a head arm holding a magnetic head is moved in the radial direction of the magnetic medium. Data is written or read by moving along the line. This type of device has traditionally detected disk load, but
As a means of detection, a micro switch or the like is used for detection, and it must be connected to the PC board side with a lead wire, resulting in high cost.
Further, a dedicated detection means is provided for detecting whether the cover is opened or closed, which increases the cost.

Purpose of the invention This invention was developed in view of the above points, and is a magnetic recording/reproducing device that can easily and inexpensively detect the disk load without the need for lead wires, and can also detect the opening and closing of the cover. The purpose is to obtain.

Summary of the invention This invention eliminates the need for lead wires by mounting the contact spring that detects the disk load directly on the PC board and protruding from the base, making it reliable and easy to manufacture. ,On this occasion,
In relation to the contact for detecting door opening/closing, one contact spring can also detect opening/closing of the door, and the structure can be made inexpensive.

Embodiment of the invention An embodiment of the invention will be described based on the drawings. First, reference numeral 1 denotes a metal base formed in a box shape with an opening at the rear end. Support pieces 2 are cut and raised on both sides of the rear end, and a cover 3 is attached with pins 4 so as to be openable and closable. has been done. On the other hand, a through hole 6 for the spindle 5 is formed in the center of the base 1 on the front end side. A media holder 8 having a pinion 7 integrally formed thereon is fitted into the upper part of the spindle 5 while being fixed by a knock pin 9. A pin 10 is provided at the top of the media holder 8 and is biased upward and can move forward and backward. Therefore, when the hole 13 of the magnetic medium 12 housed in the jacket 11 fits into this pin 10 and the spindle 5 rotates, the magnetic medium 12 in the jacket 11 rotates.

Next, gears 14, 15,
16, 17, 18, 19, and 20 are rotatably held and covered by a gear cover 21. Note that there is also a small diameter gear (not shown) on the lower surface of the gear 16. These gears constitute a reduction gear mechanism, and a gear 14 is connected to the pinion 7 of the spindle 6.
gear 16 meshes with the small diameter gear 15,
Gear 17 meshes with the gear on the lower surface of gear 16,
A gear 19 is set to mesh with the gear 18. Therefore, the gear 20 rotates at a reduced speed based on the rotation of the spindle 5 (pinion 7).
Furthermore, a head arm 22 is rotatably held on the upper surface of the base 1 by a support shaft 24 while being biased in the return direction by a return spring 23. Here,
As shown in FIG. 3, the head arm 22 includes an arm portion 22a holding a magnetic head 25 and a gear cover 2.
The arm part 22a is made of metal, and the gear part 22b is made of resin (the pinion 7 , gears 14 to 20, etc. are also made of resin molding), and both are fixed together. It is desirable that the entire head arm 22 is made of metal, but if it is made of metal, the gear 26 portion must be cut, resulting in poor productivity. However, in this embodiment, the gear 26 is formed by resin molding as the gear portion 22b.
The gear 26 portion can be easily molded and has good durability. On the other hand, if the entire body is molded with resin, the amount of displacement due to heat is larger than that of metal, and the magnetic head 25
The position of the arm 22a will be displaced, but this portion is made of metal as the arm portion 22a, and the deterioration of the amount of displacement due to heat is compensated for. Further, since this part is made of metal, it is possible to reliably swage or screw the head load arm, which will be described later, into place. And this head arm 2
A head load arm 27 is attached on the top of the magnetic head 25 for holding a pad facing the magnetic head 25 on the lower surface of the tip. This head load arm 27 is made of phosphor bronze or the like and has elasticity, is bent into a predetermined shape, and is set to press the surface of the magnetic media 12 against the magnetic head 25 with a pad pressure of about 20 g. . Here, the gear 2
0 is formed with a non-interference portion (not shown) that does not mesh with the fan-shaped gear 26. Therefore, as the gear 20 rotates, the head arm 22 moves in an arc shape in the radial direction with respect to the magnetic media 12, and when the non-interfering part of the gear 20 faces the gear 26, the head arm 22 becomes free and is moved in the opposite direction by the return spring 23. It returns quickly. 28 is a stopper that restricts the movement of the head arm 22. These reduction gear mechanisms, head arm 2
2. A head drive mechanism 29 is composed of a head load arm 27 and the like.

Next, as a support means for the spindle 5 to the base 1, there is a spindle 5 in the center of a housing 31 fixed to the base 1 by screws 30.
There is an opening through which the bearings 32 and 33 are supported, and support parts 31a and 31b for the bearings 32 and 33 are formed at the upper and lower ends of the opening. Therefore, the supporting parts 31a, 31b
Bearings 32 and 33 are fitted into the housing 1, and the bearing 32 on the base 1 side projects upwardly from the housing 31 and fits into the through hole 6 of the base 1, as shown in FIG. That is, when installing, the bearing 32 is used as a reference, and the bearing 32 is installed in the through hole 6 of the base 1 and fixed with the screw 30. Therefore, by controlling the dimensions of the flatness of the base 1, the hole diameter of the through hole 6, and the perpendicularity to the spindle 5, the spindle 5 for rotating the magnetic media 12 can be adjusted.
The perpendicularity and position of the magnetic medium 12 relative to the base 1 are ensured, and the dimensions of the position of the magnetic medium 12 relative to the magnetic head 25 on the base 1 are precise. The position of the magnetic head 25 is determined by the arm part 2 of the head arm 22.
2a. According to the conventional method, the bearing 32 is also completely embedded in the housing 31, and in order to accurately position the spindle 5 relative to the magnetic head 25, a convex part is provided in the housing and a concave part in the base. There are many unstable factors such as having to determine the position during assembly and also managing the dimensions of the convex part of the housing and the spindle, resulting in poor compatibility due to the spindle 5 being misaligned. This is an improvement over. Incompatibility is a phenomenon in which a magnetic medium written with one magnetic recording/reproducing device cannot be read accurately when used with another magnetic recording/reproducing device, and the position of the writing track and reading track is incorrect. different, the azimuth of the magnetic head is different,
The cause is that the magnetic head surface and the magnetic media surface are different. However, according to this embodiment, the positioning of the spindle 5 is accurate, and it is possible to reliably maintain the position of the magnetic medium 12 with respect to the magnetic head 25. It is possible to eliminate compatibility defects caused by positions that cannot be read by other magnetic recording/reproducing devices.

A motor 34 for rotationally driving the spindle 5 is provided. This motor 34 is a normal commutator motor, and is not coaxial with the spindle 5, but is inserted into the base 1 using a through hole 35 formed on the front end side of the base 1.
It is attached by 6. That is, it is disposed in a position where the head drive mechanism 29 is not located, and a portion of it protrudes above the top surface of the base 1, but the top surface portion of the base 1 serving as this protrusion is a dead space, and a portion of the motor 34 is There is no problem in making it stick out. By effectively utilizing such dead space, a part of the motor 34 is arranged to protrude above the base 1, so that the motor 34 occupies the lower surface of the base 1.
The thickness of the commutator motor becomes thinner, and even if a normal thick commutator motor is used, the device can be made thinner and smaller. The motor 34 and the spindle 5 are connected by a belt 37, and a driving pulley 38 and a driven pulley 39 are fixed to each. By driving the belt 37, the wow and flutter inherent in the motor 34 is attenuated, and the spindle 5 rotates stably.

Furthermore, a speed detection mechanism 40 is provided between the driven pulley 39 on the spindle 5 and the housing 31. This speed detection mechanism 40 is composed of a yoke 41, a multipolar magnet 42, an FG (Frequency Generator) plate 43, and a yoke 44. Multipolar magnet 42
As shown in FIG. 10, the magnets are equally divided into 36 poles, and are adhesively fixed to the driven pulley 39 together with the yoke 41. Further, as shown upside down in FIG. 10, the FG plate 43 is formed with a patterned conductor portion 45, and the angle in the radial direction of this patterned conductor portion 45 is the same as the angle of polarization of the NS of the multipolar magnet 42. Further, it is fixed to the housing 31 with a yoke 44 by a screw 30 so as to face the multipolar magnet 42 . Incidentally, during assembly, the housing 31, yoke 44, FG plate 43, spindle 5, bearings 32, 33, and driven pulley 39 form one unit. Now the motor 34 is rotating and the belt 3
When the multipolar magnet 42 rotates together with the driven pulley 39 via the magnet 7, the rotation of the spindle 5 is detected by the fixed FG plate 43. For example, when the magnetic flux flows as shown in the figure through the yokes 41 and 44 in the positional relationship shown in FIG. 11, a current flows in the pattern conductor portion 45 of the FG plate 43 in the direction of the arrow. And multipolar magnet 4
As the spindle 2 rotates and moves, the direction of the magnetic velocity becomes opposite, so that both ends of the patterned conductor portion 45 detect an alternating current voltage with a frequency proportional to the number of rotations of the spindle 5. The frequency detected by this FG board 43 is fed back to the motor control circuit 46, and when the rotation speed is high, a low voltage is applied to the motor 34, and when the rotation speed is low, a high voltage is applied to keep the rotation speed of the spindle 5 constant. to hold. This is an improvement over the conventional belt drive system in which speed detection was performed on the motor side, similar to the direct drive system. In other words, the factors that make spindle rotation unstable include mechanical rotational defects in the motor itself (bearing defects), transmission system (belt slippage), spindle rotational defects, etc.
Detection on the motor side cannot detect rotational fluctuations of the spindle, which may cause errors when writing or reading data. However, according to this embodiment, since the rotational speed of the spindle 5 that rotates the magnetic media 12 is directly detected, all unstable factors in rotation are checked, and they are not included in the feedback system. As a result, stable spindle rotation and therefore rotation of the magnetic medium 12 can be obtained. Therefore, accurate writing and reading becomes possible. Further, although the speed detection mechanism 40 includes a magnetic part, since it is disposed below the base 1, there is no negative magnetic effect on the magnetic medium 12 above the base 1.

Next, a PC board 48 is attached to the lower surface of the base 1 with a spacer 47 between them.
This PC board 48 has a predetermined cutout formed therein for escaping the motor 34, housing 31, etc., and the circuit components are mainly attached facing downward. this
In addition to the motor control circuit 46, the PC board 48 includes
Magnetic head 25 write circuit, read amplifier
A/D circuits, etc. are built in, and switches, sensors, etc. are also installed. For example, reference numeral 49 denotes a substantially V-shaped contact spring made of a conductive material and having spring properties attached to the tip side of the PC board 48, and its fixed end is electrically connected to the pattern part of the PC board 48. The free tip contacts and separates from the disk load detection contact 50 on the PC board 48 or the cover opening/closing detection contact 65. The bent portion of the contact spring 49 projects onto the base 1 through the square hole 51 of the base 1, as shown in FIG. 7a.
When the cover 3 is open, as shown in FIG.
When the cover 3 is closed without the magnetic media 12, as shown in FIG.
When pressed by the contact point 65, only the contact point 65 is contacted to detect opening/closing of the cover. On the other hand, when the cover 3 is closed with the magnetic medium 12 set, it is further pushed by the jacket 11 and contacts only the contact 50, as shown in FIG. FIG. 8 shows its circuit diagram. That is, the cover opening/closing signal and the DL signal are normally at H level, but when the contact spring 49 comes into contact with the contact 65, the cover opening/closing signal goes to L level and the CPU is notified that the cover 3 is closed without the magnetic media 12.
etc. will be notified. Then, the contact spring 49 is connected to the contact 50
When the magnetic media 12 comes in contact with the magnetic media 12, the DL signal goes to L level and notifies the CPU etc. that the magnetic media 12 has been set. In this manner, according to this embodiment, the contact spring 49 is directly attached and connected to the PC board 48, eliminating the need for lead wires, resulting in high reliability and good manufacturability. Moreover, two signals, the cover opening/closing signal and the DL signal, can be obtained with one contact spring 49, and the cost can be reduced by simplifying the structure.

Further, a reflection type photo sensor 53 is connected and fixed on the PC board 48 at a position slightly behind the contact spring 49 and supported by a column 52. This reflective photo sensor 53 is a combination of an LED and a photo transistor.
Easy to wire to the board 48 and easy to assemble. The reflective photo sensor 53 faces the write protection hole 54 formed in the jacket 11, and
It protrudes above the base 1 through. Therefore,
Now, when the magnetic media 12 (jacket 11) with a write protector 56 attached to the hole 54 is set as shown in FIG. 11, the light from the LED of the reflective photo sensor 53 is reflected by the write protector 56. It is detected by a phototransistor and write-protected, that is, writing is prohibited. On the other hand, in the case of the magnetic media 12 to which the write protect 56 is not attached,
The light from the LED passes through the hole 54 as shown by the dashed line and is not reflected (the inner surface of the cover 3 is black), resulting in a write enabled state. According to the conventional write protection detection mechanism, the light emitting part and the light receiving part are separated, which makes installation difficult and troublesome, but the reflection type photo sensor 53 method of this embodiment is simple.

On the other hand, the cover 3 has a magnetic medium 12 (jacket 11) inserted into it in an open state relative to the base 1, and guide ribs 5 are provided on the inner surfaces of both sides of the cover 3.
7 is formed, and a pressing spring 58 for pressing the jacket 11 against this guide rib 57 is attached. On the other hand, holding portions 59 formed higher than the guide ribs 57 are fixed to both sides of the front end of the base 1 . This holding portion 59 holds the magnetic media 1.
2 (in the height direction), and the jacket 11 set inside the open cover 3.
is pressed against the guide rib 57, as shown in FIG. The guide rib 57 is moved away from the guide rib 57, and reliable positioning is performed. Further, a lift arm 60 is fixed to the inner surface of the cover 3. This lift arm 60 is arranged to hold the head load arm 27, and does not interfere with the head load arm 27 when the cover 3 is closed, but lifts the head load arm 27 when the cover 3 is opened. be. This is because it is necessary to insert and set the magnetic medium 12 between the pads of the magnetic head 25 and head load arm 27.

By the way, when the cover 3 is opened, it must be maintained in an open state, and when it is closed, it must be maintained in a closed state. In this regard, the conventional system uses many parts such as links and related parts to regulate the opening and closing of the cover. However, in this embodiment, this stopper spring 61
It is managed in one part. This stopper spring 61 has a bent piece 61a on the fixed end side and is press-fitted and fixed into a recess 62 at the center of the rear end of the cover 3. The stopper spring 61 is curved and has a tip 61b.
indicates a click movement between the base 1 and the rear end of the base 1. As a result, when the cover 3 is in the open state as shown in FIG. will be maintained. At this time, the opening angle of the cover 3 is such that the stopper part 3a of the cover 3 is
By coming into contact with a surface, it can be easily managed and maintained without using any special member. On the other hand, when the cover 3 is closed, the tip 61 of the stopper spring 61
As shown in FIG. 7c, point b crosses over the rear end of the base 1 by a click motion and is positioned on the upper surface thereof, and a force in the closing direction acts on the cover 3, so that the cover 3 is maintained in a closed state. In this way, the cover 3 is easily maintained in the open or closed state, and there is no problem in opening and closing the cover 3.
In this case, the stopper spring 61 is curved and has a degree of play for the spring hook, so no special adjustment is required.

Effects of the invention As mentioned above, this invention has the contact spring that detects the disk load directly mounted on the PC board and protrudes above the base, eliminating the need for lead wires and making it reliable and easy to manufacture. can,
At this time, in relation to the contact for detecting door opening/closing, one contact spring can also detect opening/closing of the door, and the device can be made inexpensive.

[Brief explanation of the drawing]

The drawing shows one embodiment of this invention.
The figure is a perspective view with the cover removed, Figure 2 is a plan view thereof, Figure 3 is an exploded perspective view centered on the upper base member, Figure 4 is an exploded perspective view centered on the lower base member, and Figure 5 is an exploded perspective view centered on the base lower member. The figure is an exploded perspective view of the cover and magnetic media, and Figure 6 is a partially cutaway side view.
7a to 7c are longitudinal side views or partially cutaway side views with the cover open, and FIG. 8 is a circuit diagram;
FIG. 9 is an explanatory plan view, FIG. 10 is an explanatory view showing its operation, and FIG. 11 is a longitudinal rear view. DESCRIPTION OF SYMBOLS 1... Base, 3... Cover, 5... Spindle, 12... Magnetic media, 25... Magnetic head, 29... Head drive mechanism, 48... PC board,
49...Contact spring, 50...Contact for detecting disk load, 65...Contact for detecting cover opening/closing.

Claims (1)

[Scope of utility model registration request] A PC board is provided below the base on which a head drive mechanism, etc. for moving the magnetic head along the radial direction of the magnetic medium is provided, and a contact for detecting disk load and a contact for detecting cover opening/closing are placed close to each other on this PC board. , which is mounted on the PC board and protrudes above the base and is pushed down when the cover is closed and contacts only the cover opening/closing detection contact, while being pushed down by the magnetic media when the cover is closed when the magnetic media is inserted and set. A magnetic recording/reproducing device characterized in that a contact spring made of a springy conductive material is provided which contacts only the disk load detection contact.