JPS60214413A - Rotary head device - Google Patents

Abstract

PURPOSE:To contact a rotary head onto a tape with an optimum contact pressure by constituting the device that a moving base is displaced elastically to the outer circumference of a turning body with a centrifugal force at the turning of the turning body so that the tip of the rotary head is projected toward the outside of the outer circumferential face of a tape guide drum. CONSTITUTION:The moving base 11 is displaced elastically toward the arrow (a) to a fixed base 10 so as to be brought into contact with the 2nd stopper 13 by a centrifugal force in the direction of the arrow (c) exerted to a rotary head 4 as shown in alternate long and short dash line at the turning of an upper drum 2 and the position is regulated accurately. As a result, the tip 4a of the rotary head 4 is projected accurately with a constant projected amount A to the outside of outer circumferential faces 2a, 3a of upper/lower drums 2, 3, the position is regulated and the tip 4a is allowed to contact correctly to a magnetic tape 6 at a normal contact state. Moreover, when the drum 2 is turned at all times, since an air film is formed and the magnetic tape 6 is in the floating state B, the tip 4a of the rotary head 4 projected (A) from the outer circumferential faces 2a, 3a contacts the magnetic tape 6 at a suitable contact pressure.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a rotary head device that is most suitable for application to video cameras and pre-food devices, and in particular,
The present invention relates to a rotary head device configured to bring a rotary head such as a magnetic head into contact with a magnetic tape or the like using centrifugal force during rotation.

[Background technology and melting point]

In addition to the already known invention of rotating head devices for video tape recorders, an invention (Japanese Unexamined Patent Publication No. 50-1802
Publication No. 8).

In this known invention, a magnetic head is attached to the tip of a head base formed in a special shape, and the head base is slidably housed in a sliding groove formed on a rotating body, and at the same time, the magnetic head is perpendicular to the rotating body. Insert the fixed guide post into the long hole provided in the head base, press the head base with a presser plate attached to the rotating body, and insert the guide post between the rear end of the head base and the locking post fixed perpendicular to the rotating body. This is a locking tension spring. When the rotary body is stopped, the entire head base is pulled back toward the center of the rotary body by a tension spring, so that the entire magnetic head is completely drawn inside the slit of the tape guide drum, and the rotation of the rotary body during recording or playback. For FI#, the entire HeradPace is slid toward the outer periphery of the rotating body by centrifugal force against a tension spring, and the tip of the magnetic head is projected from the slit of the tape guide drum to the outside of the outer periphery of the drum. The magnetic tape is brought into contact with the magnetic tape.

The known inventions configured in this manner require a large number of parts and a large number of assembly steps, resulting in a lack of productivity and a significant increase in cost. In addition, the structure in which the entire heladium base slides tends to cause backlash in the magnetic head, and the magnetic head must be positioned with high precision to prevent backlash in the magnetic head during recording or reproduction. For this reason, in this known invention, a wedge-shaped protrusion regulating surface and a protruding base surface are provided on the rotating body and the head base, and during recording or reproduction, centrifugal force causes the protruding base surface of the head base to be controlled by the protruding regulating surface of the rotating body. The magnetic head is positioned by being wedged into it by a wedge action. However, machining such special shapes such as rust-shaped protrusion regulating surfaces and protrusion reference surfaces is extremely difficult and the machining cost is extremely high.

In addition, in this known invention (in which the entire magnetic head is completely retracted into the slit of the tape guide drum by a tension spring when the rotating body is stopped), the rotation of the rotating body at the start of recording or playback is At the time of start-up, the magnetic tape wound around the outer peripheral surface of the tape guide drum is easily damaged by the edges of the slits of the drum.

That is.

When the rotational speed of the rotating body rises above a certain speed and the tip of the magnetic head is rotated with the tip protruding outside the slit, an air film is formed between the tape guide drum and the magnetic tape. However, while the entire magnetic head is being rotated while being drawn into the inside of the slit, the inside of the slit is in a negative pressure state, which causes a phenomenon in which the magnetic tape is attracted into the slit. For this reason, W
When the magnetic tape is a vapor-deposited tape or a tape guide drum with slits formed between a fixed drum and a rotating drum, the magnetic tape is easily damaged by the edges of the slits.

[Purpose of the invention]

The first object of the present invention is to cause the tip of the rotary head to protrude by a certain amount to the outside of the outer circumferential surface of the tape guide drum by centrifugal force when the rotating body rotates, and to wrap the tape around the outer circumferential surface of the drum. The rotating head device is designed to be able to come into contact with the tape, which has a very simple structure and low cost, and which can be brought into contact with the tape with optimal contact pressure. The goal is to provide equipment.

In addition to the object of the rotary head Ifefi1 of the first invention, the object of the second invention in tJAK is to provide a rotary head device that is extremely easy to process and has very high productivity.

In addition to the object of the rotary head device of the first invention, a third object of the present invention is to provide a tape that is wound around the outer peripheral surface of a tape guide drum to the drum at the start of rotation of one rotating body. An object of the present invention is to provide a rotating head device that is completely free from damage caused by the edges of slits.

[Summary of the invention]

A first aspect of the present invention is to provide a head base made of a plate-like body with a fixed pace and a movable pace that can be elastically displaced with respect to the fixed base, the fixed base is fixed to a rotating body, and the tip of the movable base is A rotating head is attached to the rotary head, and when the rotating body is stopped, the tip of the rotating head is placed on the opposite side of the outer peripheral surface of the tape guide drum, and when the rotating body is rotating, the movable base is rotated by centrifugal force with respect to the fixed base. This is a rotary head device configured in such a manner that the tip of the rotary head protrudes by a fixed amount to the outside of the outer circumferential surface of the tape guide drum by elastically displacing the body toward the outer circumferential side and bringing it into contact with the °C stopper. Since the fixed base and the movable base are integrally provided, the number of parts is very small, as the only parts are the helad base and the rotating head. Furthermore, since the installation of the head base can be completed by simply screwing the fixed base to the rotating body, the number of man-hours required for assembly is very small. Therefore, the structure is very simple.

Low cost. However, since the amount of protrusion of the tip of the rotary head outward from the outer peripheral surface of the tape guide drum can be accurately regulated by the stopper, the one-rotation head can be brought into contact with the tape with an optimal contact pressure.

The second aspect of the present invention is to form a head base made of a plate-shaped body and divide it into a °C fixed base, a movable base, and a stopper, which are fixed to a fixed pace full rotation body,
A rotating head is attached to the tip of the movable base, and when the rotating body is stopped, the tip of the rotating head is placed in the same plane as the outer peripheral surface of the tape guide drum, and when the rotating body is rotating, the movable base is subjected to centrifugal force against the fixed base. This is a rotary head device configured to cause the tip of the rotary head to protrude by a fixed amount to the outside of the outer circumferential surface of the tape guide drum by elastically displacing the rotary body toward the outer circumferential side and bringing it into contact with a stopper. The three parts of the fixed base, the movable base, and the stopper can be integrally formed on the head base by simply forming a slit in the head base, which is a shaped body, and processing is extremely simple. Therefore, productivity is very high.

In a third aspect of the present invention, a fixed base and a movable base that can be elastically displaced with respect to the fixed base are integrally provided on a head base made of a plate-shaped body, and the fixed base is fixed to a rotating body l7. A rotary head is completely attached to the tip of the movable base, a first stopper and a second stopper are provided on both sides of the movable base, and when the rotating body is stopped, the movable base is brought into contact with the first stopper by its own elastic return force. The tip of the rotating head is positioned flush with the outer circumferential surface of the tape guide drum in the y plane, and when the first rotating body rotates, the movable base is elastically displaced toward the outer circumferential side of the rotating body by centrifugal force relative to the fixed base. This is a rotary head device configured to cause the tip of the rotary head to protrude a fixed amount to the outside of the outer circumferential surface of the tape guide drum by making contact with the drum. This allows the position of the tape guide drum to be very precisely regulated so that the outer circumferential surface of the tape guide drum is square.

At the start of the rotation of the rotating body, the entire head is rotated for one rotation while being drawn inside the slit of the tape guide drum, so the inside of the slit becomes a negative pressure state and the tape is sucked into the slit. Therefore, inconveniences such as the tape being damaged by the edges of the slits can be prevented.

〔Example〕

An embodiment in which the present invention is applied to a rotary head device of a video tape recorder will be described below with reference to the drawings.

First, FIG. 1 shows the entire one-rotation head device, in which a tape guide drum 1 is composed of an upper drum 2 and a lower drum 3, which are arranged on the same axis. The lower drum 3 is configured as a rotating drum that is rotationally driven by a motor (not shown), and the lower drum 3 is configured as a fixed drum that is fixed on a base. and upper drum 2
The upper drum 2 is constructed as a rotating body in the present invention, and a plurality of rotating heads 4 made of magnetic heads are attached to the outer periphery of the lower surface of the upper drum 2 by a head base to be described later.

These rotary heads 4 are rotated by the rotation of the upper drum 2.
The upper and lower drums 2.3 are configured to project from a slit 5 formed between the upper drum 2 and the lower drum 3 to the outside of the outer peripheral surfaces 2a, 3a of the upper and lower drums 2.3 and to be rotated.

On the other hand, the magnetic tape 6 has an outer peripheral surface 2a of the upper and lower drums 2.3,
3a and is spirally wound at a predetermined winding angle. Then, this magnetic tape 6 is guided by the tape lead 7 formed on the outer circumferential surface 3a of the lower drum 3, and travels around the outer circumferential surfaces 2a, 3a'i of the upper and lower drums 2.degree. 3 at a predetermined helical angle for one rotation. It is configured to be scanned by the head 4 to perform desired recording or reproduction.

Next, the mounting structure of the rotary head 4 will be explained with reference to FIGS. 2 and 3.

First, the fixed base 1 is attached to the head base 9 made of a plate-shaped body.
0, a movable base 11, and first and second stoppers 12
．． 13 are formed integrally with each other. The movable base 11 has a YL shape, for example, and the fixed base 1
The connecting portion 14t to 0 is configured to be elastically displaceable (bending) in the directions of arrows a and b in FIG. Moreover, the first and second stoppers 12,13 are arranged on both sides of the movable base 11, which is elastically displaced.

The rotary head 4 is fixed to the leading end portion 11a of the movable base 11 by adhesive or the like.

Next, the head base 9 has its fixed base 10 fixed to the outer periphery of the lower surface 2b of the upper drum 2 by screws 15, and the tip 4a of the head 4 rotates once through the slit 5 between the upper and lower drums 2.3. inserted into the section.

The movable base 11 is set to have such rigidity that it can deflect by, for example, 100 microns or more at most in the direction of the arrow a when the upper drum 2 rotates and a centrifugal force acts in the direction of the arrow C in FIG.

Therefore, first, when the upper drum 2 is stopped, the
As shown by the solid line in the figure (the movable base 11 is elastically displaced relative to the fixed base 0 by its own elastic restoring force) in the direction of the arrow, it comes into contact with the first stopper 12 and its position is accurately regulated. As a result, the tip 4a of the one-rotation head 4 is precisely positioned so that it is flush with the outer peripheral surfaces 2a, 3a of the upper and lower drums 2.3 on the Y plane. The amount of protrusion of the tip 4a of the rotary head 4 outward from the outer circumferential surfaces 2a, 3a of 2.3 is, for example, about θ to 10 microns. Therefore, when the upper drum 2 is stopped, the tip 4a of the rotary head 4 is It is in a state where it does not contact the magnetic tape 6 or only slightly contacts it.

Next, when the upper drum 2 rotates, 1 is shown in @Figure 2 and Figure 3.
As shown by the dotted chain line, the movable base 11 is elastically displaced in the direction of arrow a relative to the fixed base 10 by the centrifugal force acting on the one-turn head 4 in the direction of arrow a, and is brought into contact with the second stopper 13 and positioned accurately. Regulated. Part 17 Lever result 1
The tip 4a of the rotating head 4 is connected to the outer peripheral surface 2 of the upper and lower drums 2.3.
3.3a, the tip 4a of the head 4 is accurately brought into contact with the magnetic tape 6 in a regular contact state by accurately protruding to the outside of the magnetic tape 3a by a constant protrusion amount A of, for example, 40 to 50 microns and regulating the position. When the upper drum 2 is constantly rotated, an air film is formed between the outer peripheral surfaces 2a, 3a of the upper and lower drums 2.3 and the magnetic tape 6, as shown by the dashed line in FIG.

Since the magnetic tape 6 exhibits a floating B of about 10 to 20 microns from the outer circumferential surfaces 2a and 3a, the outer circumferential surface 2a.

The tip 4a of the rotary head 4, which protrudes from the magnetic tape 3a by about 40 to 50 microns, comes into contact with the magnetic tape 6 with optimum contact pressure.

In short, when the upper drum 2 changes from a stopped state to a rotating state, the head 4 rotates once due to centrifugal force, e.g.
The upper and lower drums 2.
However, at the start of 20 rotations of the upper drum (at the start of recording or playback), the outer peripheral surfaces 2a, 3a of the upper and lower drums 2.3 are moved outward. Since the tip 4a of the rotating head 4 is held in a protruding state of, for example, θ to 10 microns, the inside of the slit 5 becomes under negative pressure at the start of this rotation.

The magnetic tape 6 is attracted into the slit 5, and the magnetic tape 6
(especially vapor-deposited tape) is applied to the upper and lower edges 5a, 5 of the slit 5.
There is no damage caused by b.

Next, the machining and adjustment method of the head base 9 will be fully explained with reference to FIGS. M4 to FIG.

First, as shown in FIGS. 4 and M5, the head base 9 is a plate made of a metal plate having appropriate rigidity (elasticity), such as a phosphor bronze plate.

And this head base 9 has a total of 3 sulins) 17.
18 and 19 are formed parallel to each other, the head base 9 is divided into a fixed base 10, a movable base 11, and first, W, and second stoppers 12 and 13. Note that by forming the slit 17 in a YL shape, the movable base 11 is formed in a YL shape. The fixed base 10 has, for example, an obliquely cut surface 21 formed at its distal end 11m in order to have a hole 20 for inserting the screw 15 in the center thereof to reduce the shape a to a predetermined mass.

By the way, when the slits 17, 18, 19't-for example, are cut using the wire cutting method, these slits 17, 18, 19'i can only be formed to have a minimum width of about 80 microns. Can not. On the other hand, as mentioned above, the amount of elastic displacement of the tip 4a of the head 4 per rotation is, for example, 30~
It is necessary to set it to about 40 microns. Therefore, the first
The amount of elastic displacement of the movable base 11 between the second stopper 12 and the second stopper 12 and 13 in the directions of arrows a and b in FIG.
In order to regulate the size to 40 microns, the following processing and adjustments are performed.

That is, first, as shown in FIG. 4, the strips 17 and 18 on both sides of the movable base 11 are cut to a narrow width of about 80 microns. The remaining slit 19 is cut to a width of about 150 microns, for example, for the adjustment described later.

Next, as shown in the jIs diagram (, the opening end 19 of the slit 19
Drive the wedge 22 into a, glue it, and attach the first stopper 12.
The tip portion 12a of is bent in the direction of arrow a. By bringing the tip 12a of the first stopper 12 into contact with the movable base 11 and pressing the movable base 11,
The movable base 11 is bent in the direction of arrow a, and the slit 17 between the movable base 11 and the second stopper 13 is
For example, the width is adjusted to 30 to 40 microns.

Although the embodiments of the present invention have been described above, various modifications can be made based on the technical idea of the present invention.

For example, the fixed base 10 and the movable base 11 may have any shape. For example, as shown in FIG. 7, the first and second stoppers 12.13i disposed on both sides of the movable base 11 are integrally molded with a rotating body such as the upper drum 2, or are rotated by adjustment screws or the like attached to the rotating body. It is also possible to provide the movable base 11 integrally on the body side and to elastically displace the movable base 11 in the directions of arrows a and b between the first and second stoppers 12 and 13.

Regarding the groove width adjustment of the slit 17 shown in FIG.
In addition to driving in the wedge 22, adjustment can be made using each S adjustment screw.

Further, the head base 9 is not limited to a metal plate (although it may be made of various non-metal plates having desired rigidity).

Furthermore, the rotating body referred to in the present invention is not limited to rotating drums such as the upper drum 2, but may have various shapes.

It may be a rotating body of structure.

In addition, the tape guide drum referred to in the present invention is not limited to one in which the upper drum is configured as a rotating drum and the lower drum is configured as a fixed drum. It may also be one in which a drum is arranged.

Furthermore, the rotary head referred to in the present invention is not limited to a magnetic head (it may also be a rotary head of each AT recording and/or reproducing system.

[Application example]

The rotary head device of the present invention can be applied to home video tape recorders, etc.; The rotation speed of the upper drum (rotating drum) 2 (and the speed of the magnetic tape 6 1 degree) is faster (60Hz to 150Hz), so that a large centrifugal force (100OG to 3500G) acts on the head 4 for one rotation. For example, in home video tape recorders, etc., the rotation speed of the upper drum (rotating drum) 2 must be slow (about 30 Hz).
The centrifugal force acting on the rotating head 4 is also small (100G~2
00G).

Moreover, the present invention is based on '? ! The present invention is applicable to a rotary head device of a recording and reproducing apparatus using an R type recording and/or reproducing method.

〔Effect of the invention〕

The present invention uses centrifugal force during rotation of a single rotating body to cause the tip of the rotating head to protrude a certain amount of projection outward from the outer circumferential surface of the tape guide drum, and to contact the tape wound around the outer circumferential surface of the drum. This is a rotary head device designed to allow for a wide range of functions, with a very small number of parts and assembly man-hours, a very simple structure, very easy processing, and very high productivity. It is low cost.

Moreover, according to the present invention, at the start of rotation of the zero-rotating body, the tape wound around the outer circumferential surface of the tape guide drum is sucked outward into the slit provided in the drum, and the slit There is no chance of accidentally damaging the tape due to the edge of the tape.Therefore, the life of the tape can be significantly increased. This is ideal for tapes that are prone to such problems.

Further, according to the present invention, when the rotating body rotates, the protrusion 'Ik of the tip of the rotary head that protrudes outward from the outer circumferential surface of the tape guide drum due to centrifugal force can be controlled very accurately. The single-rotation head can be brought into contact with the tape with the optimum contact pressure, significantly improving the accuracy and characteristics of recording or playback.

[Brief explanation of the drawing]

The drawings show an embodiment in which the misfire 8A is applied to a rotary head device of a video tape recorder, and FIG. 1 is an overall perspective view. 1M2 is an enlarged bottom view of the main part. 1M3 is an enlarged bottom view of the main part.
Figure III-III line arrow view, Figure 4 is a bottom view explaining the processing method of the helad base, Figure 5 is the same side view,
The figure is a bottom view for explaining the method of adjusting the head base, and FIG. 7 is a bottom view similar to FIG. 2 showing a modified example. Also in the symbols used in the drawings. 1...Tape guide drum 2...
..... Upper drum 2a ..... Outer peripheral surface 3 of the upper drum .....
...Lower drum 3a...Outer peripheral surface 4 of the lower drum...
...Rotating head 4a...Tip 5 of the rotating head...
... Slit 6 ... Magnetic tape 9 ... Head base 10 ... Fla constant heath 11 ... ...Movable head x 12...First stopper 13...Second stopper 15...Screw 17...Slit 18... It is a slit. Agent Yoshio Katsutsunekane Ueya Figure 1 Figure 5

Claims (1)

[Claims] 1. A head base made of a plate-like body is integrally provided with a fixed base and a movable base that can be elastically displaced with respect to the fixed base, the fixed base is fixed to a rotating body, and the tip of the movable base is Attach a rotary head to the rotating body.9 When the rotary body is stopped, the tip of the rotary head is positioned flush with the outer peripheral surface of the tape guide drum in the y plane.When the rotary body is rotated, the movable base is moved against the fixed base by centrifugal force. A rotary head device configured to cause the tip of the rotary head to protrude a fixed amount of projection outward from the outer circumferential surface of a tape guide drum by elastically displacing the rotary head toward the outer circumferential side and bringing it into contact with a stopper. 2. Form a slit in the head base made of a plate-shaped body to divide it into a fixed base, a movable base, and a stopper, fix the fixed base to the rotating body, and attach the rotating head to the tip of the movable base to stop the rotating body. Sometimes, the tip of the rotating head is positioned on the opposite side of the outer peripheral surface of the tape guide drum.
When the rotating body rotates, the movable base is elastically displaced toward the outer circumference of the rotating body by centrifugal force relative to the fixed base and brought into contact with the stopper, thereby causing the tip of the rotating head to protrude a certain amount to the outside of the outer circumferential surface of the tape guide drum. A rotating head device configured to protrude in a large amount. 3. A fixed base and a movable base that can be elastically displaced with respect to the fixed base are integrally provided on a head base made of a plate-shaped body, the fixed base is fixed to a rotating body, and a rotating head is attached to the tip of the movable base, A first stopper and a second stopper are provided on both sides of the movable base, and when the rotating body is stopped, the movable base is brought into contact with the first stopper by its own elastic return force, so that the tip of the rotary head is moved around the outer periphery of the tape guide drum. When the rotating body rotates, the tip of the rotating head is elastically displaced toward the outer circumference of the rotating body by centrifugal force against the fixed base, which is a movable base, and brought into contact with the second stopper. A rotary head device configured to project a constant amount of projection outward from the outer peripheral surface of a tape guide drum.