JPH05307808A - Tape guide and magnetic recording/reproducing device - Google Patents

Abstract

PURPOSE:To prevent tape edges from causing a damage even if a control force by a flange exerts rapidly on the tape and to attain the cost reduction and simplification of the running system. CONSTITUTION:An outer peripheral surface of a tape contactor 40 on a tape guide 36 at the upper side taking an alignment bearing 41 as the border is formed with an inclined outer peripheral surface 40a having the slope such that the outer diameters become smaller as the positions go far from around the bearing, and the outer peripheral surface at the lower side is formed with a vertical outer periphertal surface 40b having the equal diameters. Therefore, time magnetic tape can be run by exerting a moment reducing a tape movement control force by the flange 39 and generating a friction force nigating the counterclockwise moment between the magnetic tape 37 and the vertical outer peripheral surface 40b of tape contactor 40. Also, the increase of the quantity of tape guides like the conventional method is not required.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tape guide and a magnetic recording / reproducing apparatus suitable for use in, for example, a video tape recorder.

[0002]

2. Description of the Related Art In recent years, video tape recorders (hereinafter referred to as
A magnetic recording / reproducing apparatus such as "VTR") has been remarkably popularized, and along with this, VTRs have become familiar.

Conventionally, as this type of magnetic recording / reproducing apparatus, one provided with a tape loading device having a large number of tape guides as shown in FIGS. 9 and 10, for example, has been adopted.

VTR including this tape loading device
With reference to FIG. 1, the reference numeral 1 in FIG. 1 is a tip (not shown) protruding in the outer diameter direction.
Is provided on the base plate 2, and the magnetic tape 4 in the cassette 3 is wound around the outer peripheral surface of the drum during recording and reproduction.

Reference numerals 5 and 6 are guide assemblies composed of vertical guides 5a and 6a and inclined guides 5b and 6b, which are arranged on both sides of the drum 1 and are movable on rails (not shown) on the base plate 2. Held in.

Further, 7 and 8 are roller guides on the supply side, 9 and 10 are fixed guides on the supply side, and 11 and 1.
Reference numeral 2 is a fixed guide on the winding side, 13 and 14 are roller guides on the winding side, 15 is a capstan, 16 is a pinch roller, 17 is an erase head, and 18 is a confidence head.

Numerals 19 and 20 are reels which are rotatably held on the base plate 2 and around which the magnetic tape 4 is wound.

The tape loading of the tape loading device thus configured is performed by the guide assemblies 5, 6 moving rails (not shown) on the base plate 2. That is, the guide assembly 5 on the supply side and the guide assembly 6 on the winding side, which move in opposite directions with the drum 1 interposed therebetween, draws out the magnetic tape 4 of the cassette 3 to form a spiral on the outer peripheral surface of the drum 1. Wrap around.

In a magnetic recording / reproducing apparatus equipped with this type of tape loading device, when the erase head 17 is changed from a full width erasing head to a partial erasing head, the relative height between the erasing head and the magnetic tape 4 is always stable. It is necessary to regulate by the state.

For this reason, the magnetic tape 4 is regulated to move in the tape width direction by the flanges of the respective tape guides so as to run.

[0011]

However, in the conventional tape guide, since the magnetic tape 4 travels while contacting the fixed flange, the tape running speed,
There has been a problem that the regulation force by the fixing flange abruptly acts on the magnetic tape 4 when the direction or the tension changes abruptly and the tape edge is damaged. In particular,
Since the tape guide on the upstream side of the roller guide 8 is a fixed one-side flanged guide (fixed guide 10), it is difficult for the fixed guide 10 to stably regulate the tape against variations in the tape width and variations in the tape incident height. Is.

Therefore, in the tape running system, it is conceivable that the fixed guide 10 on the upstream side of the roller guide 8 guides the magnetic tape 4 by two or more tape guides, but in this case, the number of tape guides is large. However, there is a disadvantage that not only the cost becomes high, but also the whole traveling system becomes complicated.

The present invention has been made in view of the above circumstances, and it is possible to prevent damage to the tape edge, reduce the cost, and simplify the running system. A recording / reproducing apparatus is provided.

[0014]

A tape guide and a magnetic recording / reproducing apparatus according to the present invention comprise a guide member rotatably provided on a spindle for guiding a tape, and the guide member is provided at one end of the spindle. The tape of this guide member is constituted by a flange that is held so as to be able to move forward and backward and that regulates the movement of the tape in the width direction, and a tape contactor that is provided in the axial direction of this flange and that is held by a spindle through an alignment bearing. The outer peripheral surface of the contactor, which is on the side opposite to the flange with the aligning bearing as a boundary, is formed by a circumferential surface having an inclination such that the outer diameter decreases from the vicinity of the bearing toward the far side of the bearing. The outer peripheral surface is formed by a circumferential surface having the same outer diameter.

[0015]

In the present invention, a moment for reducing the tape movement restriction force by the flange is applied to the tape contact, and a frictional force for canceling the counterclockwise moment is generated between the tape and the outer peripheral surface of the tape contact on the flange side. Tape can be run.

[0016]

Embodiments of the present invention will be described in detail below with reference to embodiments shown in the drawings.

FIG. 1 is a sectional view showing a mounted state of a tape guide according to the present invention, and FIG. 2 is an enlarged sectional view showing a tape contactor of the tape guide according to the present invention.

In the figure, the reference numeral 31 is a support shaft having a threaded portion 31a at its tip, which is fixed to a VTR base 32 and is formed entirely by a round bar extending in the vertical direction. ing.

Reference numeral 33 is a pressing member for restricting the movement of the flange.
An annular body 34 having a screw hole 34a in the center thereof which is screwed into the screw portion 31a, and a screw hole 35a which is integrally provided in the annular body 34 and which is connected to the screw hole 34a and is screwed into the screw portion 31a. Is attached to the support shaft 31.

Reference numeral 36 is a tape guide as a guide member for guiding the magnetic tape 37, and two upper and lower flanges 38 and 39, which are arranged in parallel with each other at intervals in the vertical direction,
It is composed of a tubular tape contactor 40 interposed between these flanges 38 and 39, and is provided on the support shaft 31 so as to be rotatable and movable back and forth.

Of these, the upper and lower flanges 38, 39 are held around the cylindrical body 35 and the support shaft 31, respectively.

On the other hand, the tape contact 40 has the support shaft 31.
Is held on the outer peripheral surface of the tape via a centering bearing 41 that divides the axial dimension of the tape contact surface in a one-to-one manner (located at the center of the tape contact in the axial direction). The sloped outer peripheral surface 40a of the tape contactor 40, which is the upper side with the aligning bearing 41 as a boundary, has an outer diameter that decreases from the vicinity of the bearing toward the far side of the bearing (inclination angle 3.6). Formed by a circumferential surface having
The vertical outer peripheral surface 40b on the lower side is formed by a peripheral surface having the same outer diameter. Then, the inclined outer peripheral surface 40a of the tape contactor 40 is configured to regulate the movement of the magnetic tape 37 downward. Also, this tape contactor 40
Is configured to be rotatable in an angle range in which the maximum tilt angle α is 1 ° ± 0.25 °. It has been proved by a number of experiments that the larger the inclination angle of the outer peripheral surface of the tape contactor 40, the greater the downward moving force of the magnetic tape 37.

Reference numeral 42 is a first spacer cylinder for restricting the movement of the flange, which is interposed between the upper flange 38 and the aligning bearing 41, and which is located between the outer peripheral surface of the spindle 31 and the tape contactor 40. It is arranged between the peripheral surface.

Reference numeral 43 denotes a second spacer cylinder for restricting the movement of the flange, which is interposed between the lower flange 39 and the aligning bearing 41, and which is located between the outer peripheral surface of the support shaft 31 and the tape contactor 40. It is arranged between the peripheral surface.

A compression coil spring 44 is arranged around the support shaft 31 and is elastically mounted between the base 32 and the lower flange 39.

Reference numeral 45 is a screw member for restricting the downward movement of the pressing member 33.

Next, the principle of generation of the force that the magnetic tape 37 receives from the tape contactor 40 or the lower flange 39 of the tape guide in this embodiment will be considered.

(1) First, as shown in FIG. 3, assuming that the magnetic tape 37 moves with respect to the inclined outer peripheral surface 50a of the tape contactor 50 with a slip "0", the magnetic tape 37 contacted at the portion A in FIG. Moves with the rotation of the tape contactor 50 so as to come into contact with a circle whose radius is the conical generatrix of the inclined outer peripheral surface 50a.

When this is modeled, as shown in FIG. 4, a rectangular plate W corresponding to the magnetic tape 37 is constrained to rotate at the apex E of the cone, and a force F is applied to this rectangular plate W. Can be seen. Here, considering the balance of the moment around the point E, the force G that the rectangular plate W receives from the lower flange 51 increases as the generatrix length r of the cone increases. That is, even if the inclined outer peripheral surface 50a of the tape contactor 50 is a circumferential surface having a slight gradient, if there is no slippage between the tape contactor 50 and the rectangular plate W, the rectangular plate W receives a large force from the lower flange 51. Will be received.

It is to be noted that the above-mentioned slip is less likely to occur because the tape tension is mainly large and the magnetic tape 37
This is the case where the maximum frictional force generated between the tape contactor 50 and the tape contactor 50 increases.

(2) On the other hand, in the normal tape running state,
A slip always occurs between the magnetic tape 37 and the tape contact 50. If the slip in the central portion of the tape is "0", the peripheral speed of the tape contactor 50 is smaller than the traveling speed of the magnetic tape 37 in the upper portion of the tape central portion, and in the lower portion of the tape central portion. Since the peripheral speed of the tape contactor 50 is higher, the tape contactor 50
The distribution of the force applied to the magnetic tape 37 is shown in FIG. As a result, it is considered that the magnetic tape 37 is applied with a moment H about the central portion of the tape, and is balanced with the reaction force I from the lower flange 51 and the moment of force due to restraint from another tape guide.

Incidentally, it has been empirically known that the larger the slip amount is, the larger the friction force is generated in the relationship between the slip amount and the friction force in the case of the micro slip as in this embodiment. Therefore, it is considered that the larger the gradient of the tape contactor 50 is, the larger the moment H is generated, and the larger the restriction force I by the lower flange 51 is.

As described above, when there is a slip between the magnetic tape 37 and the tape contactor 50, the inclination of the inclined outer peripheral surface 50a is such that the magnetic tape 37 is appropriately regulated by the lower flange 51. Even if the angle is small
If strong excessive tension is applied at the time of mode transition and slippage is less likely to occur, the regulation force of the lower flange 51 on the magnetic tape 37 becomes strong and the edge of the magnetic tape 37 is damaged, as shown in (1) above. ..

Therefore, the tape contactor 40 of the tape guide according to the present invention has, as shown in FIG. 6, a circumferential surface 40a having a gradient such that the outer diameter decreases from the vicinity of the bearing toward the far side of the bearing and the outer surface. Circumferential surface 40 with the same diameter
It is formed by the tape contactor which has the outer peripheral surface consisting of b.

Therefore, in this embodiment, when a high tension is applied to the magnetic tape 37, a frictional force for canceling the downward force and the counterclockwise moment generated in the upper half of the magnetic tape 37 is applied to the tape contactor. It occurs as a reaction force on the vertical outer peripheral surface 40b of 40. Further, as shown in FIG. 7, the tape contact 40 receives a moment in the C direction with the centering bearing 41 as the center J by the reaction force D of the force that pushes down the magnetic tape 37. As a result, it is considered that the contact pressure between the magnetic tape 37 and the tape contactor 40 becomes higher at the vertical outer peripheral surface 40b, and the restriction force by the lower flange 39 is further reduced.

On the other hand, during normal running of the tape with slip, a force similar to the force acting in the case of the above (2) is applied to the upper half of the magnetic tape 37, and as shown in FIG. N and a downward force n effectively act on the magnetic tape 37 from the tape contact 40.

In the present embodiment, an example in which it is applied to a VTR has been shown, but the present invention is not limited to this, and it goes without saying that it can be applied to various magnetic recording / reproducing devices and information processing devices.

[0038]

As described above, according to the present invention, the guide member for guiding the tape is held by one end of the support shaft so as to be movable back and forth, and restricts the widthwise movement of the tape.
A tape contactor which is provided in the axial direction of the flange and is held on the support shaft through an alignment bearing, and which is the outer peripheral surface of the tape contactor of the guide member and which has the alignment bearing as a boundary. The outer peripheral surface on the flange side is formed with a circumferential surface having a gradient such that the outer diameter decreases from the vicinity of the bearing toward the far side of the bearing, and the outer peripheral surface on the flange side is formed with the same outer diameter. , The tape contact travels by applying a moment to the tape contact to reduce the tape movement restriction force by the flange, and generating a frictional force to cancel the counterclockwise moment between the tape and the outer peripheral surface of the tape contact on the flange side. If the tape running speed, direction, or tension suddenly changes, the tape force is applied even if the regulation force of the flange suddenly acts on the tape. It is possible to prevent the occurrence of damage di.

Since it is not necessary to increase the number of tape guides as in the conventional case, the cost can be reduced and the running system can be simplified.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a mounted state of a tape guide according to the present invention.

FIG. 2 is a sectional view showing an enlarged tape contactor of the tape guide according to the present invention.

FIG. 3 is a front view shown for explaining a principle of generation of a force applied to a tape in a tape running state without slip.

FIG. 4 is a diagram showing FIG. 3 as a model.

FIG. 5 is a front view for explaining a principle of generation of a force received by the tape in a normal tape running state.

FIG. 6 is a front view for explaining the principle of generation of a force received by the tape in a tape running state without slipping from the tape guide according to the present invention.

FIG. 7 is a front view showing an operating state of a tape contact of the tape guide according to the present invention.

FIG. 8 is a front view shown for explaining a principle of generation of a force received by a tape in a normal tape running state from the tape guide according to the present invention.

FIG. 9 is a plan view shown for explaining the tape running system of the tape loading device.

FIG. 10 is a front view showing a supply-side tape guide in the tape traveling system.

[Explanation of symbols]

 31 ... Spindle 36 ... Tape guide 37 ... Magnetic tape 38, 39 ... Flange 40 ... Tape contactor 40a ... Inclined outer peripheral surface 40b ... Vertical outer peripheral surface 41 ... Aligning bearing.

Claims (3)

[Claims] 1. A flange which is rotatably provided on a support shaft and which guides a tape. The guide member is held at one end of the support shaft so as to be capable of advancing and retracting, and restricts a widthwise movement of the tape. A tape contactor which is provided in the axial direction of the flange and is held on the support shaft via an alignment bearing, and which is the outer peripheral surface of the tape contactor of the guide member and which is the boundary of the alignment bearing. The outer peripheral surface on the non-flange side is formed by a circumferential surface having a gradient such that the outer diameter decreases from the vicinity of the bearing toward the far side of the bearing, and the outer peripheral surface on the flange side is formed by a circumferential surface having the same outer diameter. A tape guide characterized by having. 2. The tape guide according to claim 1, wherein the aligning bearing is positioned at a central portion of the tape contact in the axial direction. 3. A magnetic recording / reproducing apparatus comprising the tape guide according to claim 1 or 2.