JPS5810213Y2 - Recording/playback device - Google Patents

Description

[Detailed explanation of the idea] This idea is.

(4) A rotating head disk with a head on its outer periphery, (
B) A guide drum disposed coaxially in close proximity to the rotating head disk (C) A fibre, which has an arcuate guide surface portion whose diameter approximates the diameter of the guide drum, in order to wind the recording medium around the guide drum. Email guide.

Regarding recording and reproducing apparatuses each equipped with the following, it is particularly suitable for application to a time-lapse VTR.

For example, in a time-lapse VTR, a female guide bends a wide magnetic tape in an arc shape in the width direction of the head disk and guide drum, and moves the magnetic tape in the axial direction of the head drum. At the same time, a magnetic head placed on the outer periphery of the head disk is scanned in the width direction of the magnetic tape.

The intended recording and playback is performed.

Since the above-mentioned magnetic head scans over an angle of 1800 degrees of the head disk, the magnetic tape is corrected by the female guide at least at an angle of 180 degrees with respect to the head disk. It has to be pushed.

This invention was made in view of these points, and there are
In the above recording/reproducing device, a groove is provided on the outer periphery of the guide drum so as to extend in the circumferential direction of the guide drum, and the arcuate guide surface portion extends over an angular range exceeding 180° of the guide drum. When the arc-shaped guide surface portion of the female guide reciprocates in the radial direction of the rotary head disk,
The present invention relates to a recording/reproducing device characterized in that the groove is configured to act as a relief for the arc-shaped guide surface portion of the female guide.

Therefore, according to the present invention, the female guide for correctly facing the recording medium over a small (180° angle) of the outer peripheral surface of the rotating head disk can be easily attached and detached by moving the head disk in the radial direction. You will be able to do this.

An embodiment in which the present invention is applied to a time-lapse VTR will be described below with reference to the drawings.

First, the outline of this VTR will be explained with reference to FIG. 1. Reels are rotatably housed in a cartridge 1 in the shape of a rectangular parallelepiped.

A magnetic tape 2 having a width of approximately 100+o++ is wound around this reel.

The magnetic tape 2 is also pulled out through a slit opening 3 formed in the cartridge 1, passes through a guide 4, and is brought into contact with a magnetic head 6 disposed on the outer periphery of a rotary head disk 5, along the axis of the head disk 5. Drive in the direction.

A pair of fixed guide drums 7.8 are arranged at both axial ends of the rotary head disk 5 in close proximity to the disk 5.

Therefore, the head disk 5 is rotatably arranged in the gap between the pair of fixed guide drums 7,80.

Then, when the pair of female guides 9 and 10, which are supported so as to be able to rise and fall, descend from above, the magnetic tape 2 is bent into an arc shape in its width direction, causing the head disk 5 and the fixed guide drum 7. It will be wrapped around the outer peripheral surface of 8.

When the head disk 5 rotates, the magnetic head 6 vertically scans the surface of the magnetic tape 2 in the width direction.
An AM modulated signal is recorded on the magnetic tape 2, or a signal recorded on the magnetic tape 2 is read and reproduced by the magnetic head 6.

Since this VTR performs solid recording without guard bands, the recording density of the signal on the magnetic tape 2 is high, long-time recording is possible, and no noise is generated during playback. ing.

The magnetic tape 2 runs in the axial direction of the head disk 5 while facing the magnetic head 6, passes through a guide 11, and is wound up by a take-up reel 12.

Next, the head assembly consisting of the rotating head disk 5, the magnetic head 6 fixed guide drum 7.8, and the female guide 9.10 will be explained with reference to FIGS. 2 to 4. It is integrally connected to one end of the sleeve 13.

The sleeve 13 constitutes a pair of bearings 15 and 160 casings that rotatably support a rotating shaft 14 passing through the center of the sleeve 13.

This sleeve 13 is fixed to the chassis 18 via a support 1γ (see FIG. 1).

A pulley 19 is fixed to the left end of the rotating shaft 14 in FIGS. 2 and 3. As shown in FIGS.

A belt 2 is placed between this pulley 19 and a pulley 21 of a motor 20 (see FIG. 1) supported on the chassis 18.
2 has been handed over.

The configuration is such that the rotation of the motor 20 is thereby transmitted to the rotating shaft 14.

Further, a rotor 23 of a frequency generator for speed detection is fixed to the rotating shaft 14.

A large number of teeth are formed on the outer peripheral surface of the rotor 23.

It faces the internal teeth of the stator yoke 24 of the frequency generator attached to the left end of the sleeve 13 in FIG.

Therefore, when the rotor 23 rotates together with the rotating shaft 14, the teeth of the rotor 23 alternately oppose the teeth and valleys of the stator yoke, thereby changing the magnetic resistance between the rotor 23 and the stator yoke 24.

When this is converted into a voltage by a coil, an alternating current voltage is obtained, which is used to detect the rotational speed and servo control the motor 20.

The rotor 23 is sandwiched between a flange 26 of a sleeve 25 fitted on the rotating shaft 14 and a flange 28 of a sleeve 27 fitted on the sleeve 25, and a nut screwed onto the left end of the rotating shaft 14. It is crimped and held by 29.

Further, the head disk 5 is fixed to the rotating shaft 14, and is configured to rotate together with the rotating shaft 14.

That is, the head disk 5 is fixed to a support disk 30, and a hollow boss 31 connected to the center of the support disk 30 has both ends connected to the rotation shaft 14.
It is attached to the rotating shaft 14 by being sandwiched between a flange 32 and a nut 33 formed on the rotary shaft 14 .

The magnetic heads 6 are attached to the outer periphery of the head disk 5 at predetermined intervals.

Further, a flywheel 34 having a relatively large mass is fixed to the right end of the rotating shaft 14 in FIGS. 2 and 3, so that the head disk 50 rotates smoothly.

A fixed guide drum 8 disposed on the right side of the head disk 5 is supported by the chassis 18 via a support 35 (see FIG. 1).

Relatively shallow circumferential grooves 36 and 37 are formed along the circumferential direction on the outer peripheral surfaces of the pair of fixed guide lower rams 7.8, respectively.

Since the diameters of these guide drums 7.8 are approximately the same as the diameter of the head disk 5,
The diameter of the head disk 5 is larger than the diameter of the circumferential grooves 36 and 37.

Further, the guide drum 7.8 is formed with a recess 38.39 extending in the axial direction on its negative side.
B.

The tip of a stopper guide 40 is received within 39 .

This stopper guide 40 is supported by the support body 35 described above.

A U-shaped bracket 41 is fixed to the support 17 that supports the sleeve 13.

A pair of blocks 42 and 43 are integrally connected to the right side of the bracket 41 in FIG. 4, and a bolt 44 is screwed to the left side so as to be adjustable.

A lock nut 45 is screwed into this bolt 44, and is configured to prevent the pole 1440 from rotating in the adjusted state.

The pair of female guides 9 and 10 are coupled to each other via a spacer 46 interposed between them.

These female guides 9 and 10 are formed with guide surface portions 47 that are substantially curved in a circular arc.

As shown in FIG. 5, this guide surface portion 47 is a circular arc portion that is formed thicker than 180°, that is, a section between points P and Q in FIG.
The tangent line drawn from the point to the above circular arc, that is, P
It is constituted by the section between the point and the R point and the section between the Q point and the 8th point.

And the angle of the section between point P and point Q, which forms a circular arc, is 1
The angle is larger than 80°, for example 202°, and an overlap angle of 11° is provided on each side for the required wrap angle of 180°.

The diameter of the guide surface 47 in the section between point P and point Q is the diameter of the head disk 5 and the guide drum 7.8.
The diameter of the outer peripheral surface of the guide drum 7. is equal to g, and the guide drum 7.
Guide drum 7.8 at the circumferential groove 36° 3T part of 8
It is constructed slightly larger than the diameter of the

Also, the section between point P and point R extending in the tangential direction and Q
The sections between the points and the eight points are configured to have an angle of, for example, 3 degrees each.

The distance between point R and point 8 is the distance between the guide drum 7.
8, the pair of female guides 9 and 10 move from above toward the radial center of the head disk 50, and the fixed guide drum 7.8 The female guide 9° and 100 guide surfaces 47 are located in the circumferential grooves 36 and 37 of the female guides 9 and 100, respectively.

Further, the distance between the R point at one end of the tangent line and the 0 point and the distance between the 8 point at the other end and the 0 point are each configured to be slightly narrower than the radius of the head disk 5.

Therefore, the magnetic head 6 attached to the rotating head disk 5 is effectively prevented from hitting the widthwise end of the magnetic tape 2.

Note that a pin 48 is attached to the female guides 9 and 10 to pass through them.

Next, the operation of winding the magnetic tape 2 around the head assembly constructed as described above will be explained.The female guide 9.degree. 10 is slowly lowered by a lifting means (not shown in FIG. 1).

A magnetic tape 2 is already stretched over the guide drum 7.8 and the head disk 5 in the axial direction thereof.

Therefore, the female guide 9, 100 guide surface portion 47 lowers the magnetic tape 2 while gradually bending it in an arc shape in the width direction.

The distance between point R and point 8 at both lower ends of the pressing surfaces of female guides 9 and 10 is configured to be slightly narrower than the diameter of circumferential groove 36°37 of guide drum 7.8. , the female guides 9, 10 are mounted on the pair of guide drums 7.8 with their guide surfaces 47 facing within the circumferential grooves 36, 37.

Both ends of the pin 48 attached to the female guides 9 and 10 are formed in a bracket 41.
The lower end of an L-shaped spacer 46 received in the blocks 42, 43 and further interposed between the female guides 9, 10 comes into contact with the upper end of a bolt 44 which has been adjusted in advance.

As a result, the female guides 9, 10 are correctly positioned so that the center of the curved guiding surface portion 47 coincides with the center of the head disk 5 and the guide drum 7.8.

In this way, the magnetic tape 2 is bent in an arc shape in the width direction along the outer peripheral surface of the pair of guide drums 7.8 and the head disk 5 disposed between these guide drums 7.8. It will be wrapped around.

Moreover, the diameter of the arc-shaped guide surface portion 470 of the female guides 9, 10 is approximately equal to the diameter of the guide drum 7.8 and the head disk 5, and furthermore, the diameter of the guide surface portion 470 of the female guide 9, 10 is approximately equal to the diameter of the guide drum 7.8 and the head disk 5.
Since the diameter of the circumferential groove 36.37 of the magnetic tape 2 is larger than the diameter of the circumferential groove 36.37 of FIG. As a result, the magnetic tape 2 and the magnetic head 6 come into contact with the outer circumferential surface of the head disk 5 with appropriate pressure.

The magnetic tape 2 is bent and wound around the kite drive =-7, 8 and the head disk 5 as described above.
On the other hand, recording or reproduction is performed while the head disk 5 rotates in the counter-time attraction direction in FIGS. 4 and 5, and the magnetic hendroid comes into sliding contact with the magnetic tape 2.

When the head disk 5 rotates, the magnetic tape 2 comes into frictional contact with the magnetic head 6 and the outer circumferential surface of the head disk 5, so that it is subjected to a force that tends to move the magnetic tape 2 in the direction of rotation of the magnetic tape 50.

However, the left end in the width direction of the magnetic tape 2 in FIG.

Since the tip of the stopper guide 40 is received in the recesses 38 and 39 of the guide drum 7.8, the magnetic tape 2 does not move in the width direction. Recording and reproduction will be performed in a state where the position is correctly regulated.

Further, tangent portions are formed at both lower ends of the guide surface portion 470 of the female guides 9 and 100, and in particular, the lower ends of these tangent portions (point R and point 8)
Since the distances between points 8 and 8 are both closer than the radius of the head disk 50, the right end in the width direction of the magnetic tape 2 in FIG. The magnetic tape 2 is located on the outside, and as the head disk 5 rotates, the magnetic tape 2 is rubbed by the magnetic head 6 to prevent the magnetic tape 2 from vibrating in the width direction.

Although the present invention has been described above with reference to embodiments, the present invention is not limited to the above-mentioned embodiments, and various modifications can be made based on the technical idea of the present invention.

For example, the above embodiment is an application of the present invention to a time-lapse VTR, but the present invention is applicable to various recording and reproducing devices in which the recording medium is wound around a head disk and a guide drum using a female guide. It is possible.

Also, what is the shape of the groove formed on the guide drum 7.8?

As described above, the drums 7.8 are not limited to those extending all the way around the outer peripheral surface, but for example, as shown in FIG. , 50.

As detailed above, in the present invention, a groove extending in the circumferential direction of the guide drum is provided on the outer periphery of the guide drum so that when the female guide reciprocates in the radial direction of the rotating head disk, Since the groove is configured so that it can act as a relief for the guide surface portion of the female guide, even if the arcuate guide surface portion is opposed to the guide drum l- in the range exceeding the central angle of 180° of the guide drum, the fife will not be affected. It is possible to bring the opposing surfaces very close to each other without any hindrance to the reciprocating movement of the mail guide.

Therefore, the wrap angle of the recording medium exceeds 1806, and the head usage efficiency during recording and reproduction is significantly improved compared to the conventional method.

[Brief explanation of the drawing]

The drawings show an embodiment in which the present invention is applied to a time-lapse VTR. Fig. 1 is a perspective view of the main parts of this VTR; Fig. 2 is a plan view of the head assembly of this VTR;
Figure 3 is a sectional view taken along the line ■ to ■ in Figure 2, and Figure 4 is the
Fig. 5 is an enlarged front view of the female guide, Fig. 6 is a sectional view taken from x to x in Fig. 4, and Fig. 7 is a main part showing a modification of this embodiment. FIG. In addition, in the symbols used in the drawings, 2...
... Magnetic tape, 5 ... Rotating head disk, 6 ... Magnetic head, 7 ... Fixed guide drum, 8 ... Fixed guide drum, 9...
... Female guide, 10... Female guide, 36... Circumferential groove, 37... Circumferential groove, 47... Guide surface section, be.

Claims (1)

[Claims for Utility Model Registration] (4) A rotating head disk with a head on its outer periphery. (B) A guide drum disposed coaxially in close proximity to the rotating head disk. (C) A guide drum having an arcuate guide surface portion whose diameter is approximate to the diameter of the guide drum in order to wrap the recording medium around the guide drum. Female guide. In the recording and reproducing device each equipped with, the arc-shaped guide surface portion is configured to face the guide drum over an angular range exceeding 180° of the guide drum, and to extend in the circumferential direction of the guide drum. A groove is provided on the outer periphery of the guide drum, and when the arc-shaped guide surface portion of the female guide reciprocates in the radial direction of the rotary head disk. A recording/reproducing device characterized in that the groove is configured to function as a relief for the arcuate guide surface portion of the female guide.