JPH0127182Y2 - - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a magnetic recording and reproducing device using a disc-shaped magnetic medium.

Such magnetic recording and reproducing devices are often used in information terminal equipment such as floppy disk devices, and can also be found on the market as audio disk devices. These devices have become highly accurate and high-density recording devices, but there has also been a demand for simple devices that can be used for memorization in a short period of time. As devices that meet such demands, the devices described in Japanese Patent Laid-Open No. 57-158067 and Japanese Patent Laid-Open No. 57-158068 are relatively close to each other. These devices use the same drive source to move the head and rotate the disk, and in order to enable the head to return, a non-interfering part is provided in the gear to cut off power transmission when the head returns. , a return spring is provided.

Since these devices cannot be returned to positions other than the non-interfering portion of the gear, they always require full-range operation.

The purpose of this invention is to be able to return the head from any position, and to return the head by any desired amount.
Moreover, it is an object of the present invention to provide a magnetic recording/reproducing device with a simple structure and without track deviation.

This invention will be explained below with reference to the accompanying drawings.

FIG. 1 is a schematic plan view showing a power transmission system in an embodiment of the invention, and FIG. 2 is a schematic cross-sectional view taken along the line A--A. The head arm 2 that holds the head 1 and the sector gear 3 are integrally formed,
It is supported swingably around an arm support shaft 4. The sector gear 3 meshes with a second pinion 6 that is formed coaxially and integrally with the entire shaft 5. An elastic ring claw 7 formed with a groove so that the tip claw portion 71 can be elastically deformed inward is also fixed to the entire shaft 5, and a second gear 8 is rotatably fitted therein. There is. A plurality of ratchet teeth 9 are formed in the center of one surface of the second gear 8 and protrude inwardly.
is becoming more and more disengaged. In second gear 8,
A third pinion 12 coaxially formed integrally with a drive shaft 11 that drives a magnetic medium disk 10 meshes with it. A third gear 13 is also fixed to the drive shaft 11, which meshes with a fourth pinion 15 coaxial with the fourth gear 14, and the fourth gear 14 meshes with a worm gear 16. Worm gear 16
A friction plate 19 housed in a cup 18 is fixed to the worm shaft 17 .

As is clear from FIGS. 2 and 3, the support shaft 4 of the head arm 2 is rotatably fitted into a boss hole 22 of a boss 21 rising from a base plate 20. As shown in FIGS. A portion 231 of the upper plate 23 where the sector gear 3 and the second pinion 6 that mesh therewith are located is recessed, and the portion where the head arm 2 moves is cut out. A side wall 24 is integrally formed around the top plate 23 so as to cover the bottom plate 20. Between the base plate 20 and the upper base plate 23, a Zenmai 26, a Zenmai shaft 5, an elastic ring pawl 7, a second gear 8, and a third gear are housed in a barrel 25 integrally formed on the base plate 20. A speed increasing gear train consisting of a pinion 12, a speed regulating mechanism consisting of a third gear 13, a fourth pinion 15, a fourth gear 14, a worm gear 16, a cup 18, a friction plate 19, and this invention constitute a voice toy. If so, batteries, electric circuits, speakers, etc. are accommodated. A pedestal 27 for supporting the magnetic disc 10 in addition to the above-mentioned head arm 2 is fixed to the entire mounting shaft 11 from above the upper base plate 23. A detent pin 28 is fixedly planted on the pedestal 27, and the hole for the full axis and the hole for the detent pin provided at the center of the magnetic disk 10 are connected to the axis 1, respectively.
1 and the pin 28, the magnetic disk 10 is set on the pedestal 27. A hole 29 is provided in the center of the head arm shaft 4 in the axial direction, and a pad holder 30 is press-fitted into the hole 29. The part holder 30 has an insertion hole 3.
1 and an engaging protrusion 32 are provided, into which a pad spring 33 is inserted. A pad 34 is bonded to the back side of the tip of the pad spring 33, and presses the magnetic disc 10 against the head 1 and moves following the head 1.

Next, the operation of this device will be explained. As shown in FIG. 1, the counterclockwise side of the claw tip 71 of the elastic ring claw 7 fixed to the full swing shaft 5 and the side of the ratchet tooth 9 that engages with this part are Both sides are formed diagonally, and the opposite sides are formed toward the center, so when winding up the Zenmai 26, that is, the Zenmai axis 5.
When rotates counterclockwise, the elastic ring pawl 7
Since the elastic pawl 71 slides on the ratchet teeth 9, no power is transmitted to the second gear 8, and only the second pinion 6 rotates, causing the head arm 2 to rotate clockwise through the sector gear 3. Zenbu 2
The winding of the head arm 6 is carried out by a pulley or a knob (not shown) fixed to the full-length shaft 5, and the head arm 2 is moved from the position shown in FIG. I'm learning not to go inward. When the head arm 2 reaches a predetermined inner position and unwinds the full length 26 by its own force, the full length shaft 5 rotates clockwise, the elastic pawl 71 engages with the ratchet teeth 9, and the second gear is engaged. 8 rotate in the same direction, and the magnetic disc drive shaft 11, the pedestal 27, and the magnetic disc 10 are rotated counterclockwise via the third pinion 12. At the same time, the sector gear 3 and head arm 2 rotate counterclockwise via the second pinion 6, and the gap portion of the magnetic head 1 forms a spiral track trace on the surface of the magnetic disk 10.

Therefore, by sending a recording signal to the magnetic head 1 or taking out a reproduction signal from the magnetic head 1, recording on the magnetic disk 10 or reproduction from it becomes possible. The rotational speeds of these wheel trains and head arms are controlled to be constant through a third gear 13, a fourth pinion 15, a fourth gear 14, a worm gear 16, and brakes 18 and 19. The friction plate 19 is a rubber ring provided with arms, and the arms extend outward due to centrifugal force and press against the inner wall of the cup 18, thereby controlling the speed.

By the way, in order to enable reproduction in such a device, the gap portion of the head must necessarily pass over the tract trace formed on the magnetic disk during recording. If the full length shaft 5 and the second gear 8 are directly connected, this is possible no matter how the full length 26 is unwound. However, in this case, the magnetic disc 10 must be rotated at a considerable speed when winding the entire winder 26 manually, causing the head 1 and the magnetic disc 10 to be worn out quickly. Therefore, in this invention, when winding up Zenmai 26, the disc 10
A ratchet mechanism is provided on all winding shafts 5 to prevent the winding from rotating, but while this allows the head 1 to return from any position on the track trace, the disc 10 does not rotate synchronously with this, so the amount of winding is limited. In some cases, the head 1 may not be correctly positioned on the tract trace at the end of winding. For this reason, in this invention, the number of meshing parts of the ratchet teeth 9, that is, the number of teeth R, and the speed increasing ratio up to the pedestal 27 are adjusted so that the head 1 always aligns with the tract trace no matter how much it is hoisted. The relationship with N is determined so that N/R=integer, so N=integer. This condition will be explained below with reference to FIG.

In Fig. 4, N ₁ is the number of teeth of sector gear 3,
n ₂ is the number of teeth on the second pinion 6, R is the number of teeth on the ratchet teeth, N ₂ is the number of teeth on the second gear 8, n ₃ is the number of teeth on the third pinion 12, and T is the spiral track on the disk 10. Traces and H indicate the locus of the gap position of head 1, respectively. Now, assuming that the head gap position is at point _H6 on the _T6 trace,
When the entire gear is wound up and the second pinion 6 is rotated by one ratchet tooth 9, or 1/R, the number of revolutions of the sector gear 3 becomes 2/N ₁ × 1/R, and the head _gear Moving on to _H5 . and,
In order for the full length to unwind from this _H5 position, the ratchet tooth 9 to rotate by one tooth, or 1/R, and the head gap to return to the original _H6 position, the disk 10 must rotate once. . Therefore, here 1/R×N ₂ =1×n ₃ or 1/R×N ₂ /n ₃ =
Conditional expression 1 is satisfied. This N ₂ /n ₃ is nothing but the speed increasing ratio N described above.

The above conditional expression is for the case where the head gap position shifts to the next trace for every 1/R rotation of the ratchet tooth 9. Although this is the most preferable case, it does not matter what the total winding amount is. However, in order to satisfy the condition that the head gap position is always located on the trace, it is not necessarily limited to this case. That is, there is no problem even if the head gap position jumps from the current position to the third or fourth trace for each 1/R rotation of the ratchet tooth 9. Therefore, the above conditional expression is 1/R×
N ₂ /n ₃ = integer, therefore N is changed to integer.

In addition, in the case of n ₂ = R, 1/1 of the ratchet tooth 9
For each R rotation, sector gear 3 is R/N ₁ × 1/R
=1/N Since it rotates by _one rotation, that is, by one tooth of the sector gear 3, the trace pitch on the disk 1 corresponds to one tooth of the sector gear 3, which is convenient in terms of design.

In this invention, the head arm 2 is
The structure can be modified to adopt a linear tracking system as shown in Japanese Patent No. 57-158067. In addition, as a drive source, a motor capable of forward and reverse rotation can be used in addition to Zenmai, but Zenmai has the advantage of not generating electrical noise and being able to operate only by the amount of winding. be.

As described above, according to the magnetic recording and reproducing device of this invention, the ratchet mechanism that allows rotation in only one direction is provided in the magnetic disk drive system, so that the conventional non-interfering part or head can be used to return the head. There is no need for a return spring, the structure is simple, and the tract trace can be freely operated not only in the entire area but also in the middle or halfway. Furthermore, even if the magnetic disc rotates, the relationship between the ratchet teeth and the speed increasing ratio is properly determined, so no track deviation occurs, and the engagement of the ratchet teeth and the track trace of the head perfectly match. The device according to this invention can also be used as a reproduction-only machine.

[Brief explanation of the drawing]

FIG. 1 is a schematic plan view of a power transmission system in an embodiment of the magnetic recording/reproducing device according to this invention, and FIG.
The figure is a schematic cross-sectional view of the magnetic recording/reproducing device according to this invention taken along the line A-A in FIG. 1, FIG. It is an explanatory diagram of operation in one embodiment of the invention. 1...Magnetic head, 2...Head arm, 3...
...Sector gear, 4...Arm support shaft, 5...Full axis, 6...2nd pinion, 7...Elastic ring pawl,
8...Second gear, 9...Ratchet tooth, 10...
Magnetic disc, 11...Disc drive shaft, 12...Third pinion, 13...Third gear, 14...Fourth gear,
15...4th pinion, 16...worm gear,
18, 19...Brake part, 26...Full dance.

Claims (1)

[Scope of utility model registration request] A device in which a magnetic head slides in spiral contact with a magnetic medium disc to record and reproduce signals, the device comprising a pedestal for supporting the disc, a holding member for holding the head, and driving the pedestal and the holding member. a drive source capable of reciprocating rotation, and a speed-increasing gear train and a ratchet mechanism provided between the pedestal and the drive source, the ratchet mechanism having a plurality of meshing parts equally spaced in the same direction. and a magnetic recording/reproducing device in which a speed increase ratio with respect to the pedestal is an integral multiple of the number of engaging parts of the ratchet.