JPS629569Y2 - - Google Patents

Description

[Detailed Description of the Invention] This invention relates to an improvement of a head access device applicable to a recording and reproducing device using a disk-shaped recording medium, and aims to provide a device that allows easy alignment of the head to a reference track. The first magnetic recording and reproducing device using a magnetic sheet, which is a disk-shaped recording medium, is
As shown in the figure, a motor 1 rotates a magnetic sheet 2 at high speed above a fixed table 3, while a head access device 4 moves a head 5 to the magnetic sheet 2.
In one known device, the head is accessed in the radial direction of the magnetic sheet, so that a unit video signal consisting of one field or one frame can be recorded on each of the concentric tracks of the magnetic sheet and can be repeatedly played back. Here, the head access is performed by converting the rotation of the stepping motor 6 into the linear motion of the access shaft 7 equipped with the head 5, but in order to access the entire area of multiple tracks with the required accuracy, it is necessary to accurately regulate the position of the head 5 at the middle position (N/2 track) of the accessible N tracks. For this reason, in the prior art, the mounting position of head access device 4 attached to fixed table 3 is configured to be finely adjusted in the direction of arrow 8, and after the head position is adjusted, a screw 9 is tightened to fix it. Alternatively, as shown in FIG. 2, a head base 10 to which head 5 is fixed is made adjustable relative to access shaft 7 using a screw 11, and after adjustment, a screw 12 is tightened to fix it. However, in either case, some deviation of the head position (on the order of several tens of microns) cannot be avoided by re-tightening screw 9 or 12 after fine adjustment, and when making adjustments, it is necessary to understand the characteristics such as the direction and amount of change in the head gap position due to the tightening of each screw, and this adjustment work is very difficult and takes a long time.

The present invention aims to provide a head access device that can alleviate the difficulty of this adjustment work and accurately regulate the head position.

FIG. 3 shows one embodiment of the device of the present invention. Reference numeral 13 denotes an access shaft, and a head is attached to the tip of the shaft via a head base in the same manner as shown in FIG. 1, so that the head can be accessed in the radial direction of the magnetic sheet.
14 is a housing having side walls 15, 15 and 16, 16 and a bottom plate 17, and the access shaft 13 is a bearing 1 provided on the side walls 15, 15 of this housing 14.
8,18. This housing 14 is adapted to be attached to the lower surface of the fixed table 3 using screw holes 19 provided in side walls 15, 15. 20 is a stepping motor, and this motor is configured to be attached to the bottom plate 17 of the housing 14 via a table 21. A rotating shaft 22 of the motor 20 projects inside the housing 14, and a rotating body 23 is fitted therein. This rotational movement of the rotating body 23 is controlled by the access shaft 13.
In order to convert the linear motion of
Blocks 25, 2 installed at two locations in the axial direction of 3
I am trying to install it on 6. 27 is a spring for preventing backlash.

The table 21 includes a protrusion 28 having a circumferential surface whose center coincides with the axis of the motor, grooves 29, 30, and 31 formed on an arc whose center coincides with the axis, and a through hole extending in the radial direction. It is equipped with 32. On the other hand, the bottom plate 17 constituting the housing 14 has a through hole 33 inscribed in the protrusion 28, and a screw hole 3 that is screwed into the screws 34, 35, and 36 that are loosely fitted in the respective grooves.
7, 38, 39, and a hole 42 for supporting an operating shaft 41 for controlling a cam 40 circumscribing the inner surface of the through hole 32.

In such a device of the present invention, to define the head position, slightly loosen the screws 34, 35, and 36, and
The table 21 may be rotated about the axis of the motor 20 with respect to the bottom plate 17 by controlling the operating shaft 41. This rotation allows the stator of the stepping motor 20 to be displaced with respect to the bottom plate 17, the rotor and rotating body 23 to be rotationally displaced in response to the rotation, and the access shaft 13 to be moved minutely. After this adjustment, screw 3 to fix the table 21 to the bottom plate 17.
4, 35, and 36 are fastened, but the stress at the time of fastening does not act to cause displacement of the access shaft 13, and sufficient consideration is not required when fastening unlike the conventional example.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram of a conventional magnetic recording/reproducing apparatus, and FIG. 2 is a partially cutaway side view of a head base thereof. FIG. 3 is a partially cutaway perspective view of the device of the present invention, and FIG. 4 is a plan view of the same device. 13...Access axis, 14...Housing, 2
0... Stepping motor, 24... Belt (conversion means), 17... Bottom plate of housing, 22...
Motor rotation axis, 21...Table, 29,3
0, 31... groove, 34, 35, 36... screw,
32...Through hole, 41...Operation shaft (rotation center axis),
40...Cam (cam for table rotation adjustment).

Claims (1)

[Claims for Utility Model Registration] In order to access the head in the radial direction of a disk-shaped recording medium, there is provided an access shaft for fixing the head at one end, and a housing having a bearing for slidably supporting the access shaft. , a stepping motor having a rotating shaft protruding within the housing; a converting means for converting the rotational movement of the stepping motor into a linear movement of the access shaft; a table that is rotatable about the axis of the rotating shaft with respect to the bottom plate; a groove provided on the table and formed on an arc whose center coincides with the axis; a groove passing through the groove; A head access device comprising: a screw for fixing the table to the bottom plate; a through hole provided in the table and extending in the direction of the axis; A head access device comprising: a circular table rotation adjustment cam with an eccentric central axis.