JPS62277674A - Position detecting mechanism for head carriage - Google Patents

Abstract

PURPOSE:To detect the recording initiation with high accuracy by using a 1st disk which can be controlled in the circumferential direction of a feed gear, a 2nd disk which revolves at a speed different from the feed gear and can be controlled in the circumferential direction of a rotor, and a detector which detects the coincidence between the through-holes of both disks. CONSTITUTION:The revolving speeds and directions of disks 15 and 16 are decided by an output shaft 8' of a stepping motor 8 via a train of planetary gears. Then the number of these planetary gears and the number of teeth of gears are set so that no coincidence is obtained between through-holes 151 and 161 of both disks as long as the shift value of a head carriage is kept within a range less than the recording area of a magnetic disk. Therefore, the coincidence between both through-holes is obtained only at the recording initiation of the 1st track within the recording area of the magnetic disk. Thus the recording initiation point of the 1st track can always be decided when a detector 17 detects the coincidence between both holes 151 and 161 of disks 15 and 16. In such a way, the recording initiation point of the 1st truck can be easily detected with high accuracy.

Description

[Detailed description of the invention] 3. Detailed description of the invention.

[Industrial application field]

The present invention relates to a position detection mechanism capable of highly accurately detecting the recording start end of a head carriage mounted with a magnetic head for recording or reproducing information on a rotating magnetic disk.

[Cost of invention]

Electronic still cameras are a recent video recording device that has attracted attention. This is a magnetic recording system based on the concept of an optical camera, and it has been decided to standardize the magnetic disk used as the recording medium, and full-scale practical use is expected.

The standard for such magnetic disks is the disk radius.

The recording position from the disc center to the first trunk, the pitch of each track, etc. are measured, and in particular, the distance from the disc center to the recording position of the first track is 20 m.
”-0,014m, the pinch between the tracks is 0.1mm
Therefore, extremely high precision is required for position detection and feeding.

Conventionally, Japanese Patent Laid-Open No. 60-50773 discloses a feeding device for moving a head carriage in the radial direction of a magnetic disk. This uses the high reduction ratio of a planetary gear train to enable the head carriage to be moved in small steps, but since this is a reproduction-only machine, the detection of the start of the first track is highly accurate. It's not necessary and it's a very rough setup. That is, in the case of playback, the head is moved from the center to the outer side of 20 cranes, scans in the center direction from there, detects the recorded signal, and determines the position where the output is the highest as the first track. This is because if you do so, you will be able to achieve your goal. Moreover, in the above-mentioned conventional system, all the members that move in conjunction with the movement of the head carriage move in small increments, so it is very difficult to detect the recording position of the first track as precisely as 2011±0.014 +n. Of course, this is not impossible, but since it involves detecting minute displacements or angles, it requires a highly accurate and complex position detection device.

[Purpose of the invention]

In view of the above-mentioned points, it is an object of the present invention to provide a head carriage position detection mechanism that has a simple structure and can detect the recording start edge with high precision and easily.

[Structure of the invention]

To achieve the above object, the present invention includes a first disk that is circumferentially adjustable and attached to a feed gear of a head carriage equipped with a magnetic head for recording or reproducing information on a rotating magnetic disk; On the other hand, a second disk is attached to a rotating body that can be rotated at different speeds so as to be adjustable in the circumferential direction.

a detector for detecting the coincidence point of the through holes provided at one location on each disk; In addition, if the coincidence point of these through holes is once aligned with the recording start edge of the magnetic disk, the recording start edge can be easily detected thereafter.

〔Example〕

The present invention will be described below based on embodiments shown in the accompanying drawings.

Figure 1 shows a device such as an electronic still camera.
In the figure, reference numeral 1 denotes a main body of the apparatus, and the main body 1 has a rotating shaft 2 of a disk drive motor (not shown) to which a central core 43 of a magnetic disk 42 housed in a flat container 41 is coupled as shown in the fourth figure. is provided. This magnetic disk 42
The recording surface thereof is exposed by opening a shutter 45 through an opening 44 provided in the flat container 41.

Reference numeral 3 denotes a magnetic head 3a that performs recording or reproduction on the recording surface of the magnetic disk 42 exposed through the aperture 44 of the flat container 41.
The head carriage 3 is equipped with
can slide along a guide bar 4 fixed to the main body 1 of the device.

5 is a feed gear meshed with a sector gear 7 provided integrally with a step gear 6 meshed with the rank portion 3' of the head carriage 3; the feed gear 5 is a motor gear fixed to the output shaft 8' of the stepping motor 8; (Sun gear) 9 is rotated via a planetary gear reduction mechanism. That is, when the motor gear 9 fixed to the output shaft 8' of the stepping motor 8 rotates as shown in the second figure, the internal gear 12 is rotated in the opposite direction to the motor gear 9 via the pinion 11 pivotally supported on the gear base plate 10. The rotation of is transmitted. The rotation of this internal gear 12 is transmitted to a planetary gear 14 pivotally supported by the feed gear 5 via an internal gear 13 having an integral structure. The planet gear 14 also meshes with the motor gear 9. Therefore.

A series of motor gear 9 - small gear 11 - internal gear 12 and a series of motor gear 9 - planetary gear 14 - internal gear 13 are created.1 Since the transmission ratio of the gear train is different in the two systems, the difference is As a result, the planetary gear 14 revolves around the motor gear 9, so that the feed gear 5 rotates slowly. Due to this rotation of the feed gear 5, the head carriage 3 is moved to the magnetic head 3a via the sector gear 71 and the stage gear 6° rank 3'.
move with

Reference numeral 15 denotes a first disk that is fixed to the feed gear 5 so as to be adjustable in the circumferential direction with a screw 15a, and 16 refers to the internal gear (rotating body that rotates at a different speed than the feed gear 5) 12 (13). This is a second disk that is fixed with screws 16a so as to be adjustable in the circumferential direction. Therefore, the first disk 15 rotates extremely slowly together with the feed gear 5, and the second disk 16 rotates faster and in the opposite direction. A through hole (slit or punched hole) 151.161 is provided at one location of each of these disks 15.16.

Reference numeral 17 denotes a detector that detects the coincident point of the through hole 151 of the first disk 15 and the through hole 161 of the second disk 16. It is equipped with an element and a light receiving element.

In the above embodiment, the head carriage 3 is moved to set the magnetic head 3a mounted thereon on the first track of the magnetic disk 42, and at that position, the first disk 15 and the second disk 16 are respectively fixed. screw 15a,
16a, rotate both disks in the circumferential direction, align the through holes 151 and 161 with the detection position of the detector 17, and retighten the screws.・Output shaft 8' of knobing motor 8
is determined via a planetary gear train, and furthermore, this planetary gear train and its number of teeth are determined by the amount of movement of the head carriage in the recording area of the magnetic disk (the pitch between tracks is 0.1 m).
+i, 50 tracks) If it is set so that the holes 151 and 161 of both disks do not coincide in the range below, at least in the i3 area of the magnetic disk, the point where the holes coincide will be the recording start end of the first track. Only. Therefore, whenever the detector 17 detects a matching point between the through holes 151 and 161 of the first disk 15 and the second disk 16, that position can always be determined as the recording start end of the first track.

When the magnetic head 3a is first set on the first track of the magnetic disk 42, its position is specified as 20±0.014 tm from the center of the disk, and extremely high precision is required. If the center of the magnetic disk is accurately determined using an optical microscope or the like, an accurate position of 20 m±0.014 mm from the center can be easily determined.

In the above embodiment, a planetary gear mechanism is used as the speed reduction device, but if there is another suitable device, it is free to use it.

〔Effect of the invention〕

As explained above, the present invention includes a first disk that is circumferentially adjustable and attached to a feed gear of a head carriage equipped with a magnetic head for recording or reproducing information on a rotating magnetic disk; The invention is characterized by being equipped with a second disk that is adjustable in the circumferential direction on a rotating body that can rotate at different speeds, and a detector that detects the coincident point of the through holes provided at one location on each disk. Therefore, first set the magnetic head on the first track of the magnetic disk, and at that position, align the through holes of the first disk and the second disk with the detection position of the detector, and If the rotational speed and rotational direction are set so that the through holes in both disks will not fail when the amount of movement of the head carriage is less than the recording area of the magnetic disk, the matching point of the through holes will be at the position detected by the detector. This method has an excellent effect in that the recording start end of the first trunk can be detected easily and with high precision.

[Brief explanation of the drawing]

FIG. 1 is a plan view showing the structure of an embodiment of this gear;
FIG. 2 is a sectional view of the main part, FIG. 3 is a perspective view thereof, and FIG. 4 is a plan view of the external appearance of the magnetic disk. 1.-Device main body 3-Head carriage 3a-
Magnetic head 5-Feed gear 9-・Motor gear (sun gear) 11・-Small gear 14-Planetary gear 12.13・
・-Internal gear (rotating body) 15--First disk 16--Second disk 151,
161-Through hole 17-Detector Fig. 1 Fig. 2 Fig. 3 Fig. 4

Claims (2)

[Claims] (1) A first disk that is circumferentially adjustable and attached to a feed gear of a head carriage equipped with a magnetic head for recording or reproducing a rotating magnetic disk, and that can rotate at a different speed with respect to the feed gear. A head carriage position detection mechanism comprising: a second disc mounted on a rotating body so as to be adjustable in the circumferential direction; and a detector for detecting a coincident point of a through hole provided at one location on each disc. . (2) The head carriage position detection mechanism according to claim 1, wherein the first disk and the second disk are connected to a drive source by a speed reduction mechanism using a planetary gear mechanism.