JPS634409A - Rotary head device - Google Patents

Abstract

PURPOSE:To decrease the wear of a magnetic head and to reduce damage given to a recording medium by adopting the constitution in which the magnetic head is arranged in a recessed part of a rotary drum provided to a slit side and no space is given between the recessed part and the magnetic head. CONSTITUTION:The magnetic head 5 is arranged to the recessed part 7 of the drum 1 and a sliding face 6 and a magnetic gap 8 are protruded from the circumferential face of the upper drum 1. A synthetic resin 21 such as a silicone resin is packed in the space caused between the recessed part 7 and the magnetic head 5 to imbed the magnetic head 5 in the upper drum 1 and then no space exists. In driving the upper drum 1 having a radius Rd at the circumferential velocity V, denoting a floating quantity of a magnetic tape 4 in front of the magnetic head 5 in the advancing direction as Hd3, denoting the floating quantity at the rear direction as Hd4, then since no space exists between the recessed part 7 and the magnetic head 5, the quantities Hd3, and Hd4 are equal to each other, the relative pressing between the magnetic had 5 and the magnetic tape 4 is relaxed more than a conventional example and the wear of the magnetic head 5 is decreased. Further, the damage to the magnetic tape 4 is relaxed.

Description

[Detailed description of the invention] [Industrial application field] This invention relates to a rotating head device.

(Conventional technology) Figures 4 to 8 show a conventional rotary head device.

In FIG. 4, a cylinder C is composed of an L tram l and a tod drum 2, and a slit 3 exists between them. A magnetic tape 4 (recording medium) is wound around a cylinder C. The magnetic head 5 is fixed to the top drum L, and the sliding surface 6 (described in ?) with respect to the magnetic tape 4 is fixed to the top drum L.
It protrudes from the circumferential surface of the drum l. Of the drum 1 and the drum 2 constituting the cylinder C, the drum 2 is a fixed drum, and the drum 1 is a rotating drum. The magnetic head 5 rotates together with the upper tram 1, and its sliding surface 6 runs on the magnetic tape 4F. FIG. 5 shows an enlarged view of the vicinity of the magnetic head 5, and FIG. 6 shows the mounting state of the Mi magnetic head with the drum 1 reversed and made smaller. In the figure, numerals 1 to 5 indicate the same items as in FIG. A recess 7 opened in the circumferential surface of the upper tram 1 is provided on the slit 3 side of the upper tram 1, and a magnetic head 5 is fixed within the recess 7. 8 indicates a magnetic gap of the magnetic head 5.

Next, I will explain fishing use.

First, for comparison, a case where neither the recess 7 nor the magnetic head 5 is present on the drum will be described with reference to FIG. Now, assuming that the magnetic tape 14 is wound around the cylinder C1 and the upper drum 11 rotates at a circumferential speed of ■, when the L drum 11 is static, the magnetic tape 14 is wound around the top drum 11.
To! ! If the upper drum 11 is in tight contact, or if the upper drum 11 rotates, the air is viscous, so as the upper drum 11 rotates, the air will also be dragged by the surface of the upper drum 11 and move. As a result, the upper drum 11 and the magnetic tape 14
During this time, an air current flowing in the rotational direction of the upper drum 11 is generated, and the magnetic tape 14 is lifted off the upper drum 11. Then, the magnetic tape 11 and the magnetic tape 14 move relative to each other at a certain distance. This distance fiHd is calculated using the following formula!
I can get it.

Here, Rd is the i diameter of the human tram 11, μ is the viscosity of air, ■ is the relative speed between the upper tram 11 and the magnetic tape 14,
T is the tension applied in the longitudinal direction of the magnetic tape.

However, as in the conventional example, there is no recess 7 or 7L in the upper drum 1.
As a result, the air flow between the drum 1 and the magnetic tape 4 is not uniform, so that the magnetic tape 4 floats -1 at the front and rear sides of the recess 7 as shown in FIG. In other words, assuming that 7 and 5 are not placed in the magnetic field,
xi ] dielectric charge d + of the portion of the magnetic tape 4 located in front of the recess 7 with respect to the rotation of the upper drum 1 is the same as the floating +, ) Hd when there is no recess 7; Floating weather Hd 2 is about one order of magnitude smaller than this. Along with this, at the position of the recess 7, the magnetic tape 4
floating J: i+t decreases, and in some cases upper drum 1
It may become lower than the circumferential surface of and sink into the recess 7.

[The problem that the invention attempts to solve]

The effect that the presence of the recess 7 has on the magnetic tape 4's float rate as described above occurs regardless of whether the magnetic head 5 is attached or not. In the past, in the conventional example shown in FIGS. 4 to 6, the presence of the recess 7 prevented the magnetic tape 4 from floating
1 decreases, conversely the protrusion M of the magnetic head 5 increases. As a result, the magnetic head 5 and the magnetic tape 4 come into contact, and the large contact pressure at this time causes the magnetic head to
Wear: Tsuji becomes larger. Further, the damage to the magnetic tape due to the running of the magnetic head 5 increases, and in the worst case, scratches may occur. Furthermore, if the magnetic tape 4 sinks into the recess 7, particularly the recess 7 behind the magnetic head 5, the magnetic tape 4 will come into contact with the corner of the recess 7 behind the magnetic head 5 and be damaged. Furthermore, the presence of the recess 7 reduces the flying height of the magnetic tape 4 and relatively increases the amount of protrusion of the magnetic head 5, causing an increase in jitter 11''. That is, when the magnetic head 5 enters the magnetic tape 4, the rolling resistance between the two sides 4.5 increases, causing vibration in the width direction of the magnetic tape 4, which causes an increase in the amount of sick.

The degree of reduction in the flying height U of the magnetic tape 4 due to the presence of the recesses 7 increases as the tape becomes thinner. Especially recently, VTR
In order to lengthen the recording time, the warm-up tape is made thinner, so the presence of the recess 7 at 7F causes the recording time to be longer. 'I
The decrease in i is becoming more serious.

This invention solves the conventional problems mentioned above.
(1) 1'? of the magnetic head.
? Wear: 11 or less, (2) Damage to the recording medium is small, (1) There is no risk of scratches on the recording medium due to friction with the magnetic head, (4) There are no scratches on the recording medium due to friction with the rotating drum. (5) The jitter can be improved, and (6) the output of the magnetic head will not be lowered, thus improving durability and reliability. −． An object of the present invention is to provide a rotary head device that provides a rotary head device.

[Seven stages for solving the problem] The rotating head device according to the present invention has a slit provided on the side between the rotating drum and the fixed track l, which is opened on the circumferential surface of the rotating drum. Connect the recessed portion of the rotating drum and the magnetic head placed in this recessed portion, and connect +iif recessed)■ and electricity! This is a configuration in which there is no space between the top and the bottom.

[Effect]

In the rotary head device according to the present invention, since there is no space between the recess and the magnetic head, even if an air flow that flows in the rotational direction of the rotary drum occurs between the rotary drum and the magnetic tape, the air flow It does not change after IFj in the heavy rotational direction of the magnetic head. Therefore, the flying height of the magnetic tape from the rotating drum does not change after +Jf of the magnetic head and become smaller at the rear.

〔Example〕

1 and 2 illustrate embodiments of the present invention, and parts that are the same as or corresponding to those in FIGS. 4 to 6 are given the same reference numeral 7J'r.

FIG. 1 shows a human ram 1 with a magnetic head 5 mounted thereon in reverse, and corresponds to FIG. 6 of the conventional example. In the figure, the configuration in which the magnetic head 5 is disposed in the recess 7 of the todrum 1 and the sliding surface 6 and the magnetic cap 8 protrude from the circumferential surface of the todrum 1 is the same as in the conventional example. However, whereas in the conventional example, the magnetic head 5 was installed in the recess 7 of the upper tram 1, in this embodiment, a synthetic resin 22 such as silicone resin is installed in the space created between the recess 7 and the electric head 5. The difference is that the magnetic head 5 is buried in the drum 1 by filling the drum with the magnetic head 5. As a result, in the conventional example, the space between the magnetic head 5 and the recess 7 is
In this example, such a space part or if
- Not present.

By the way, the surface shape of the synthetic resin 21 filling between the recess 7 and the magnetic head 5 on the drum surface is not necessarily flush with the drum surface, and even if there is a slight difference in level. good.

Basically, it is sufficient that air does not flow in or out of the stepped portion, so it is sufficient that the depth of the stepped portion is sufficiently small compared to the method in the plane direction of the synthetic resin surface. Specifically, it is sufficient if it is 1710 or more.

Further, even if a gap exists between the synthetic resin 21 and the recess 7 or the magnetic head 5, it does not matter as long as the air flow is not blocked.

Next, the operation will be explained with reference to FIG.

This figure corresponds to No. 8-1 of the conventional example.

Now, if the tod drum 1 with diameter Rd is rotating at a circumferential speed V, and the floating height of the magnetic tape 4 in the forward direction of the magnetic head 5 is expressed as Hd, and the floating amount at the rear is expressed as Hd4, then the concave portion 7
Since there is no space between the magnetic head 5 and the H
d3 and Hd4 are equal and equal to the value shown by the above formula (+). Also, the floating point of the magnetic tape 4 in the vicinity of the magnetic head 5;
affected only by.

As a result, first, when the magnetic tape 4 floats, the magnetic head 5
Since there is no large decrease in the vicinity of the magnetic head 5
The degree of relative pressing between the magnetic tape 4 and the magnetic tape 4 is relaxed compared to the conventional example, and the wear and tear on the magnetic head 5 is reduced. Furthermore, for the same reason, damage to the magnetic tape 4 caused by the running of the magnetic head 5 is alleviated, and damage to the magnetic tape 4 caused by the magnetic head 5 is prevented.

Further, the flying height of the magnetic tape 4 does not particularly decrease near the electric head 5, and since the recess 7 is not open [1] in the circumferential surface of the tod drum 1, the magnetic tape 4 There is no possibility that the material will come into contact with the corner of the recess 7 and be damaged. Also, due to these "l +, t',
Since the running resistance of the magnetic tape 4 is reduced, the thickness is improved.

Furthermore, in the conventional configuration example, as the magnetic tape 4 became thinner, ■γ human 1: decreased greatly;
According to the configuration of the example, the conventional problems are basically solved, so even if the magnetic tape 4 is made thinner, no problem occurs.

In addition, [the throat wear of the magnetic head 5 using the two-legged embodiment]
) and output characteristics, the wear τ! compared to the conventional example. : was significantly improved, but no change was observed in the output.

FIG. 3 shows a second embodiment of the invention.

This is done by molding the magnetic head 5 by embedding it in a synthetic resin 22 such as silicone resin, forming a package head H with a winding end r23, and then molding it to fit the shape of the package head H. The magnetic head 5 is fixed to the drum 1 by fitting it into a recess 7 provided in the drum 1. Compared to the first embodiment, this embodiment has the advantage of improved productivity because it is easier to fill and mold the resin near the magnetic head 5.

(Effects of the Invention) As explained above, according to the present invention, (1) the amount of wear on the magnetic head is small, (2) the damage to the recording medium is small, and (3) the friction between the recording medium and the magnetic head is reduced. (4) There is no risk of scratches caused by printing.
To obtain a rotating head device which is free from the risk of scratches caused by the magnetic head, (5) can improve jitter, and (6) does not lower the output of the magnetic head, and therefore has improved durability and reliability. Can be done.

[Brief explanation of drawings]

Fig. 1 is a perspective view of the main part of the 1st embodiment of the present invention, which corresponds to Fig. 6, Fig. 2 is an explanatory view of the operation of the first embodiment, and Fig. 3 is the second embodiment. FIG. 4 is a perspective view of a conventional rotary head device, FIG. 5 is a side view of the main part of FIG. 4, FIG. 6 is a perspective view of the main part of FIG. 4, FIG. FIG. 8 is a diagram for explaining the operation of the embodiment. 1. Rotating tram 2 --- Fixed drum 3 --- Slit 4 --- --Magnetic tape (recording medium) 5...
-Magnetic heads 21, 22=---Synthetic resin Note that in the drawings, the same reference numerals indicate the same or corresponding parts. = Lnp −4u”)p

Claims (2)

[Claims] (1) It has a rotating drum, a recess of the rotating drum that is opened on the circumferential surface of the rotating drum and provided on the side of the slit between the rotating drum and the fixed drum, and a magnetic head disposed in the recess, and A rotary head device characterized in that there is no space between the recess and the magnetic head. (2) A synthetic resin is interposed between the recess and the magnetic head so that there is no space between the recess and the magnetic head. rotating head device.