JPH0669715U - Rotation position detection device for disk rotation drive device - Google Patents

Abstract

(57) [Abstract] [PROBLEMS] To provide a rotational position detecting device for a floppy disk capable of stably and accurately and reliably detecting the rotational position and sector control position by a photo interrupter. A positioning locking portion 13 is provided on a rotor frame 6 which is a main body of rotation of a disk rotation driving device, and a metal plate 15 is engaged with the locking portion and is directly attached to the rotor frame. Slits 17 for passing light rays are provided at predetermined intervals near the outer peripheral edge of the metal plate at equal intervals radially with respect to the rotary drive shaft 1 for sector control signals. , Two slits 18 are provided within the slit width of the slit 17 for the position detection signal, and the position detection signal and the sector control signal are detected by one optical detector 16.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a rotational position detecting device for a disc rotation driving device used to drive a so-called floppy disc.

[0002]

[Prior art]

 As storage media for computers and the like, floppy disks with large storage capacity, high compatibility, small size, and easy to handle have been put into practical use and are widely used. Recently, disk devices with storage capacities of 10 MB and 20 MB have begun to be commercially available. . In addition, those 20 Mbyte disk devices must be compatible with 1 Mbyte and 2 Mbyte.

In this floppy disk, a disk-shaped disk hub made of a metal plate is provided at the center of the disk, and a center hole and a drive pin engagement are respectively provided at the center of the disk hub and a position eccentric from the center. A coupling hole is provided to engage the center rotation shaft of the spindle hub of the disk rotation drive device with the center hole, and the drive pin standing upright at a position eccentric from the center engages with the drive pin engagement hole. The chucking structure is such that the rotation of the spindle hub is transmitted to the disc hub to drive the disc to rotate.

A conventional rotation position detecting device for a disk rotation driving device will be described below. FIG. 4A is a half top view of a conventional disk rotation drive device, and FIG. 4B is a half cross sectional view. In FIG. 4, 21 is a rotary drive shaft, 22 is a deep groove ball bearing, 23 is a spindle hub into which the rotary shaft 21 is press fitted, 24 is a bearing housing, 25 is a stator core, 26 is a rotor frame crimped to the spindle hub 23, Reference numeral 27 is a drive magnet, 28 is a frequency generating magnet (hereinafter abbreviated as FG magnet), 29 is a printed circuit board, 30 is a metal plate, and 31 is an optical detector.

The structure of a conventional rotational position detecting device for a disk rotation driving device will be described below with reference to the drawings.

A disk rotation drive device that drives a floppy disk or the like that needs to detect a position signal has a circular metal plate 30 mounted on the surface opposite to the FG magnetized surface of the FG magnet 28 mounted on the rotor frame 26. As a result, the metal plate 30 rotates integrally with the rotor frame 26. A slit 32 for passing a light beam is provided at a predetermined position near the outer peripheral edge of the metal plate 30, and a light emitting element that emits a light beam fixed at a certain distance from the metal plate 30 and a light receiving device that receives the light beam. An optical detector 31 with integrated elements is provided on the printed board 29, and the position of the index is detected by blocking and passing the light beam by the slit 32.

As a rotation position detecting device of the rotation driving device of the disk configured as described above, the metal plate is adhered to the FG magnet or integrally formed with the FG magnet.

[0008]

[Problems to be solved by the device]

 However, in the above-mentioned conventional configuration, when a single FG magnet is fixed to the rotor frame by adhesion, the FG magnetized surface is used as a reference for adhesion, so the opposite surface of the FG magnetized surface is a surface that is not aligned with the rotation axis due to mounting errors. The runout is bad, and therefore the runout of the metal plate attached to that surface is also bad. Also, when a resin magnet is integrally molded on the rotor frame to form an FG magnet, the gate is on the surface opposite to the FG magnetized surface. Since a mouth is provided, an error is likely to occur due to sink marks, etc. Therefore, the surface runout of the above surface with respect to the rotation axis is bad, and even if a metal plate is attached to that surface, the surface runout of the metal plate is bad. However, there is a problem that an error is likely to occur.

[0009] Furthermore, the FG magnet, which is made of resin, is inferior in weather resistance to the rotor frame made of metal even in a heat cycle or a change with time, and thus an error is likely to occur in the position of the metal plate or a surface wobble is likely to occur. There was a flaw.

The present invention solves the above problems, and an object of the present invention is to improve the positional accuracy of a metal plate and the index positional accuracy of a floppy disk.

[0011]

[Means for Solving the Problems]

 In order to achieve this object, the rotation position detecting device of the disk rotation driving device of the present invention is provided with a locking part by coining or the like on a part of the rotor frame, which is the main body of rotation of the disk rotation driving device. The structure is such that a metal plate provided with a slit for detecting the index is engaged with and directly attached to the rotor frame.

[0012]

[Action]

 With this configuration, the positioning accuracy of the metal plate is improved, and the surface runout of the metal plate is reduced because it is not affected by the change over time, and the index detection accuracy is improved.

[0013]

【Example】

 Hereinafter, a method of mounting a metal plate on a rotor frame according to an embodiment of the present invention will be described with reference to the drawings.

FIG. 1A is a half top view of a disk rotation drive device including a rotation position detecting device according to an embodiment of the present invention, and FIG. 1B is a half cross-sectional view. 1, 1 is a rotary drive shaft, 2 is a deep groove ball bearing, 3 is a spindle hub, 4 is a bearing housing, 5 is a stator core, 6 is a rotor frame, 7 is a drive magnet, 8 is an FG magnet, and 9 is a printed circuit board. 10 is a metal plate, 11 is an optical detector, 12 is a slit provided in the metal plate 10, and 13 is a locking portion for positioning with the metal plate 10 provided in the rotor frame.

The disk rotation drive device rotates about a rotation drive shaft 1, and the rotation drive shaft 1 is supported by a ball bearing 2 and rotates smoothly. The ball bearing 2 is mounted inside the bearing housing 4, and the bearing housing 4 is fastened and fixed to the printed circuit board 9. A rotor frame 6, which is the main body of rotation of the disk rotation drive device, is attached by fastening and fixing the spindle hub 3, and the rotation drive shaft 1 is press-fitted to the spindle hub 3.

A drive magnet 7 is fixed to the inside of the outer peripheral surface of the rotor frame 6, a current is passed through a coil wound around the stator core 5 to generate a revolving magnetic field, and a torque is generated between the drive magnet 7 and the drive magnet 7. It is generated and the rotor frame 6 is rotated. A magnetic pole for frequency power generation is magnetized on a surface 14 of the FG magnet 8 formed integrally with the outer peripheral portion of the rotor frame 6 on the printed board 9 side, and a magnetic field generating coil composed of a group of power generating line elements is formed on the surface 14 of the printed board 9. Is provided and the generated voltage by the frequency generating magnetic pole is supplied to the drive circuit of the disk rotation drive device to control the disk rotation drive device at a constant rotation speed.

Positioning holes are provided in the top surfaces of the metal plate 10 and the rotor frame 6, and a pin is passed through the holes to fix the metal plate and the rotor frame. Alternatively, the top surface of the rotor frame is subjected to coining to provide the positioning locking portion 13, and the positioning locking portion is engaged with the positioning engaging hole provided in the metal plate to attach the positioning locking portion 13 to the top surface of the rotor frame 6. Attach the metal plate 10.

A slit 12 is provided near the outer periphery of the metal plate 10, and the metal plate 10 is passed between the photo interrupters, which are optical detectors 11. When the rotor frame rotates, the metal plate also rotates, and the slit 12 near the outer peripheral edge of the metal plate detects the slit position by blocking and passing the light beam of the optical detector, thereby detecting the rotational position of the disk rotation drive device. do.

Hereinafter, another embodiment of the present invention will be described with reference to the drawings. FIG. 2A is a half top view of a disk rotation driving device including a rotation position detecting device according to another embodiment, and FIG. 2B is a half sectional view. In FIG. 2, 1 is a rotary drive shaft, 2 is a deep groove ball bearing, 3 is a spindle hub, 4 is a bearing housing, 5 is a stator core, 6 is a rotor frame, 7 is a drive magnet, 8 is an FG magnet, and 9 is a printed circuit board. The above is the same configuration as in FIG.

Further, 15 is a metal plate, 16 is an optical detector, 17 is a slit for radial control signals provided on the metal plate 10 at equal intervals, and 18 is a slit for position detection.

A high-capacity disk rotation drive device employs a sector servo system for writing and reading information signals on the disk in synchronization with each sector of the disk. In addition, because it is backward compatible, it is necessary to generate a pulse once per rotation and detect the position that indicates the start and end of the track (called index detection).

3 (a) and 3 (b) are examples of another metal plate of the present invention. FIG. 3A shows only a part of the slits on the entire circumference. FIG. 3B is an enlarged view of the slit portion. Another position detecting device of the present invention will be described with reference to FIG.

In a disk rotation drive device that drives a floppy disk or the like that requires a function of detecting a sector signal and a position signal, a circular metal plate 15 that rotates integrally with the rotor frame 6 is directly engaged, and the metal A slit is provided at a predetermined position near the outer peripheral edge of the plate 15 for the purpose of passing and blocking the light beam, and a light emitting element that emits the light beam fixed at a certain distance from the metal plate 15 and a light receiving element that receives the light beam are provided. A single integrated optical detector 16 is provided on the printed circuit board 9, and slits 17 are radially formed with respect to the rotary drive shaft at regular intervals except for one position at a predetermined position near the outer peripheral edge of the metal plate 15. The sector control signal of the disk rotation drive device is obtained by the light beam passing through these slits 17, and the sector control signal slit is provided at one of the slits. The position detection signal is obtained by providing two slits 18 within the slit width of the unit.

In the example of FIG. 3, the sector slit width angle α is (360/112) degrees, the two index slit width angles β and γ are the same, (360/336) degrees, The width angle of the metal between the index slits is also (360/336) degrees. Therefore, the width angle δ including the two index slits is (360/112) degrees, which is equal to the sector slit width angle α.

[0025]

[Effect of device]

 As described above, according to the present invention, the metal plate is positioned by coining or inserting the pin into the rotor frame, which is the main body of rotation of the disk rotation drive device, and the metal plate is directly attached to the rotor frame. As a result, the centering of the metal plate and the accuracy of the rotational position are improved, the surface runout of the metal plate is small, and a highly reliable disk rotation drive device with little change over time can be provided.

A rotation position detection device for a disk rotation drive device that detects a position detection signal and a sector control signal by a single optical detector by blocking and passing light rays by a plurality of slits near the outer peripheral edge of a metal plate can be provided. .

[Brief description of drawings]

FIG. 1A is a half top view of a disk rotation drive device according to an embodiment of the present invention. FIG. 1B is a half sectional view of FIG.

FIG. 2A is a half top view of a disk rotation driving device according to another embodiment of the present invention. FIG. 2B is a half sectional view of FIG.

FIG. 3A is a diagram showing an example of a metal plate of a disk rotation drive device according to another embodiment of the present invention. FIG. 3B is an enlarged view of FIG. 3A.

FIG. 4A is a half top view of a conventional disk rotation drive device, and FIG. 4B is a half sectional view of FIG.

[Explanation of symbols]

 1 Drive shaft 2 Ball bearing 3 Spindle hub 4 Bearing housing 5 Stator core 6 Rotor frame 7 Drive magnet 8 Frequency generating magnet 9 Printed circuit board 10, 15 Metal plate 11, 16 Optical detector 12, 17, 18 Slit 13 Locking part

Claims (2)

[Scope of utility model registration request] 1. A disc rotation drive device is provided with a locking portion on a part of a rotor frame, a circular metal plate rotating integrally is directly engaged, and a slit is formed at a predetermined position near an outer peripheral end of the metal plate. Is provided with an optical detector that is integrated with a light emitting element that emits a light beam and a light receiving element that receives the light beam, which is fixed at a certain distance from the metal plate, Position detection device of a disk rotation drive device that detects the position of the index by shutting off and passing through. 2. A locking portion is provided on a part of a rotor frame of a disk rotation driving device, and a circular metal plate that rotates integrally is directly engaged with the disk. The sector control signal slits of the rotary drive device are provided at equal intervals radially with respect to the rotary drive shaft except one location, and one of the slits is two slits within the slit width of the sector control signal slit. Is provided with a slit for position detection signal, and one optical detector is integrated with a light emitting element for emitting the light beam and a light receiving element for receiving the light beam, which are fixed at a fixed distance from the metal plate. A disk rotation drive device that detects a position detection signal and a sector control signal by the optical detector by blocking and passing the light beam by a plurality of slits near the outer peripheral edge of the metal plate. Rotational position detector.