JPH0619919B2 - Magnetic head feeder - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic head feeding device, and more particularly to a magnetic head feeding device for performing magnetic recording or magnetic reproduction on a cassette type magnetic disk.

[Background of the Invention]

Recently, a combination of an image pickup device such as a solid-state image pickup device and an image pickup tube and a recording device using a magnetic disk which is inexpensive and has a relatively large storage capacity as a recording medium has been used as a disc that rotates a still electronically photographed subject. An electronic still camera system has been developed in which recording and image reproduction are performed by a separate television system or printer.

In an image recording or reproducing system using such a magnetic disk, a disk having a diameter of about 50 mm is used, and in this magnetic disk, a recording pattern from 1 track to 52 tracks from the outer circumference side to the inner circumference side. Is formed. The magnetic head feed is about 100 μm, which is much smaller than the feed pitch of a normal floppy disk, and therefore the magnetic head must be moved with extremely high accuracy. And the start position of the magnetic head (moving start position)
The home position is set to a predetermined position on the outer peripheral side from one track or a position of one track, and acts as a reference position when recording or reproducing by sending the magnetic head in the radial direction of the magnetic disk, and the end position of the magnetic head. The end position, which is the (movement end position), is formed at a predetermined position on the inner circumference side from the 52 track, and acts so that the magnetic head does not move beyond the predetermined recording range of the magnetic disk. Therefore, in the magnetic disk device in the electronic camera system, it is necessary to detect the home position and the end position and stop the feeding of the magnetic head at the home position or the end position.

Further, the home position acts as a reference position for forming each track when the magnetic head is fed at a constant value to record on the disk, so that the position is detected with high accuracy and the magnetic head is stopped with high accuracy. Need to let.

[Object of the Invention]

The present invention has been made in view of such circumstances, and proposes a magnetic head feeding device that detects a home position and an end position of a magnetic head and stops the magnetic head at the home position or the end position. Has an aim.

[Outline of Invention]

In order to achieve the above object, the present invention is provided with a motor, a head carriage provided with a magnetic head and moved by being guided by a guide member, and a drive gear attached to a rotation shaft of the motor. And a transmission means for converting the driving force of the carriage into a linear movement of the carriage and transmitting the movement, and the magnetic head moves in a radial direction with respect to the magnetic sheet housed in the magnetic sheet pack to record or In a magnetic head feeding device for reproduction, a first control gear meshed with the drive gear and rotated by the motor, and having first through holes communicating between both end surfaces, and the first control gear. A second through hole that is arranged coaxially with the control gear, is meshed with the drive gear, is differentially rotated with respect to the first control gear, and has a second through hole that connects both end faces to each other.
Control gear, and a detection section including a light emitting element and a light receiving element provided with the first and second control gears sandwiched therebetween, and the detection section includes the first through hole and the second through hole. It is characterized in that the position of the carriage is detected by detecting the coincidence with the through hole.

〔Example〕

Hereinafter, preferred embodiments of a magnetic head feeding device according to the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 is a plan view showing this embodiment. As shown in FIG. 1, a main body 10 of a cassette type magnetic disk recording apparatus such as an electronic camera or a reproducing apparatus is formed in a rectangular shape. A disc pack 12 is placed on the main body 10 as shown by an imaginary line in FIG. 1, and a disc 20 is stored in the disc pack 12 by a rotary shaft 16 of a disc driving motor 14.
Is rotatably engaged and placed.

First, the structure of the disc pack 12 will be described. The disc pack 12 is rotatably mounted in the pack body 18 and inside thereof as shown in FIGS. 2 (A) and 2 (B). 1 and 2 (A).
It is mounted on the main body 10 of the magnetic disk device with its surface facing upward so that the end face indicated by arrow A is common.

The magnetic disk 20 is composed of a disk-shaped magnetic recording material 22 having a recording layer formed on the back surface thereof, and a center core 26 having a hole 24 at the center for engaging the rotating shaft 16 of the disk drive motor 14. The pack body 18 is a magnetic disk 20.
Openings 28, 30 for exposing the center core 26 of the
Also, it has openings 31 and 32 for exposing the recording surface and the non-recording surface of the magnetic disk 20, so that the magnetic head can be projected from the opening 32 to the recording surface to perform recording or reproduction. There is. The member indicated by the chain double-dashed line 33 is a shutter, and the pack body 18 is inserted into the reproducing device.
When taken out, the shutter 33 slides to open the holes 31 and 3.
Open and close 2.

A head carriage 36 is slidably arranged on the apparatus body 10 as shown in FIG. That is, the head carriage 36 serves as the magnetic disk 20 in the disk pack 12.
1 is provided with a magnetic head 38 for performing magnetic recording or reproduction, and is slidable in the left-right direction in FIG. 1 along guide bars 40 and 42 fixed to the apparatus main body 10. The rotational force of the stepping motor 43 is transmitted to the head carriage 36 via the gear train 37, and the head carriage 36 is slightly fed. That is, the output shaft 44 of the stepping motor 43 is provided with the gear 46, and the gear 46 meshes with the gear 50 provided on the intermediate shaft 48. The intermediate shaft 48 is provided with a screw gear 52.
The pin 5 protruding laterally from the head carriage 36
4 is in mesh. In this way, the rotational force of the stepping motor 43 is transmitted to the head carriage 36.

Next, a device for detecting the home position and end position of the magnetic head 38 will be described.

The gear 46 of the output shaft 44 is meshed with gears 56 and 58 arranged coaxially with the shaft 60. The number of teeth of the gear 56 is Z ₅₆ =
25, and the gear 58 is formed with the number of teeth Z ₅₈ = 26. The gears 56 and 58 having different numbers of teeth are common to the gear 46.
The gears are displaced between the gears 56 and 58 and the gear 46 in order to mesh with the gear. Further, through holes 56A and 58A are formed in the gears 56 and 58 as shown in FIG.
Detection units 62 are provided on both sides of 6, 58. The detection unit 62 includes a light emitting element 62A and a light receiving element 62B, and sends a signal to the stepping motor 43 when the through holes 56A and 58A of the gears 56 and 58 coincide with each other to control the movement of the stepping motor 43.

The operation of the embodiment according to the present invention configured as described above is as follows.

First, the rotational force of the stepping motor 43 is the gear train 3
It is decelerated via 7. The stepping motor 43 rotates 18 ° in one step. The gear train 37 drives the stepping motor 12 steps, and when the gear train 37 reduces the speed, the head carriage 36 can be moved by 100 microns. In this way, the magnetic head 38 is provided for each track (100 microns) with respect to the magnetic disk 20 in the disk pack 12.
Can be moved and recorded or played back.

The positional relationship between the through holes 56A and 58A of the gears 56 and 58 is as shown in FIG. In the table shown in FIG.
When the through holes 56A and 58A are aligned when the number of feed steps of the stepping motor 43 is 0, the gear 56 (the number of teeth Z ₅₆ = 25) makes one rotation in 25 steps, and the gear 58 (the number of teeth Z
₅₈ = 26) rotates 25/26 times. Thereafter, the stepping motor 43 is driven to rotate 650 steps, and the gear 56 (Z
_{When 56} = 25) rotates 26 times, the gear 58 (Z ₅₆ =
26) rotates 25 times, and the positions of the through holes 56A and 58A coincide with each other. Therefore, when the home position is set when the number of feed steps of the stepping motor 43 is 0, and when the end position is set when the number of feed steps is 650, the detection unit 62 detects the position where the through holes 56A and 58A coincide. As a result, the head carriage 36 can be stopped and the magnetic head 38 can be positioned at the home position or the end position.

〔The invention's effect〕

As described above, according to the magnetic head feeding device of the present invention, the pair of control gears that are coaxially arranged and meshed with the drive gear of the motor are formed with through holes, and the through holes are located at the same position. Is detected by the detection unit and the home position or the end position is determined from the coincident position, so that the home position or the end position can be set accurately.

[Brief description of drawings]

FIG. 1 is a plan view showing the overall structure of this embodiment, and FIGS. 2 (A) and 2 (B) are front and rear views showing a magnetic disk pack used in the above embodiment of the present invention. Three
FIG. 4 is a sectional view of the main part of this embodiment, and FIG. 4 is a diagram showing the relationship between a pair of position detecting gears used in this embodiment. 10: Main body of magnetic disk recording or reproducing device, 2
0 ... magnetic disk, 36 ... head carriage, 38
...... Magnetic head, 56,58 ...... Gear, 56A, 58A
...... Through hole, 60 ...... Axis, 62 ...... Detection part.

Claims (1)

[Claims] 1. A motor, a head carriage provided with a magnetic head and moved by being guided by a guide member, and a drive gear mounted on a rotation shaft of the motor, and the drive force of the motor is supplied to the carriage. A transmission means for converting the movement into a linear motion and transmitting the movement, and the magnetic head moves in the radial direction with respect to the magnetic sheet housed in the magnetic sheet pack to perform recording or reproduction on the magnetic sheet. In the feeding device, a first control gear meshed with the drive gear and rotated by the motor and having a first through hole communicating between both end surfaces, and a first control gear coaxially arranged with the first control gear. At the same time, it meshes with the drive gear and differentially rotates with respect to the first control gear,
A second control gear in which a second through hole is formed to connect both end faces to each other; and a detection unit formed of a light emitting element and a light receiving element sandwiching the first and second control gears, A magnetic head feeding device, characterized in that the position of the carriage is detected by detecting that the first through hole and the second through hole are coincident with each other by the detection unit.