JPS5951065B2 - rotating head device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a rotary head device for a recording/reproducing apparatus in which a recording/reproducing head supported by a rotating support body is brought into contact with a recording medium to perform recording and/or reproduction.

For example, in a VTR (video tape recorder), a rotating magnetic head attached to a rotating head drum is brought into contact with a running magnetic tape to record and reproduce video signals.

In this case, since the relative speed of the magnetic head to the magnetic tape is very high, a clock phenomenon in which magnetic powder coated on the surface of the magnetic tape falls off and adheres to the surface of the magnetic head easily occurs. Ta. This phenomenon particularly tends to occur during playback when the running of the magnetic tape is interrupted and the magnetic head is repeatedly brought into contact with the same portion of the magnetic head. If such a clock phenomenon occurs, magnetic powder will be present between the magnetic tape and the magnetic head, which will have an adverse effect on recording and reproducing video signals, or will make recording and reproducing impossible.

Conventionally, when applying magnetic powder to a magnetic tape, special treatments were applied to prevent the magnetic powder from falling off, the edges of the magnetic head were curved, the tension of the magnetic tape was weakened, and the magnetic Efforts have been made to reduce the amount of head protrusion from the outer circumferential surface of the rotating head drum, or to lower the indoor humidity to reduce the adhesion of magnetic powder to the surface of the magnetic head. However, none of these measures were sufficient, and it was impossible to completely prevent clocks. The present invention has been made with the aim of overcoming such problems, and is designed to perform recording and/or reproduction by bringing a recording/reproducing head supported by a rotating support into contact with a recording medium. A rotary head device for a recording/reproducing apparatus comprising: a gas intake means for the rotating support, a gas guide means for guiding the gas taken in by the gas intake means, and a flow rate adjustment for adjusting the flow rate of the gas. means, the flow rate of the gas taken in from the gas intake means is adjusted by the flow rate adjustment means by the rotation of the support body, and the gas guiding means adjusts the flow rate of the gas taken in from the gas intake means, and the gas guiding means adjusts the flow rate of the gas taken in from the gas intake means. This invention relates to a rotating head device characterized in that the spray is applied to a contacting portion.

Therefore, according to the present invention, the contact pressure of the recording medium with respect to the recording/reproducing head can be adjusted to an optimum value by spraying the gas whose flow rate is adjusted to the contact area between the recording/reproducing head and the recording medium. , it is possible to perform good recording and reproduction while effectively preventing clock interference with an extremely simple configuration. An embodiment in which the present invention is applied to a force setting type VTR will be described below with reference to the drawings.

First, the outline of TR will be explained with reference to FIG. The tape is pulled out by the four tape pull-out pins 6 planted on the deing ring 5 and the guide pin 8 on the tape pull-out arm 7, and mounted on the tape running path as shown in FIG.

The pulled-out magnetic tape 4 is then passed around a full-width erasing head 9, a rotating head drum 10, an audio erasing head 11, and a combination head 12. In this state, when this VTR is switched to recording or playback mode using an operation button (not shown), the magnetic tape 4 is pressed by the pinch roller 14 against the capstan 13, which rotates at a constant rotational speed, and the magnetic tape 4 is 4 is the head 9
, 1], 12 and a rotating head drum 10,
Moreover, it travels at a constant speed while slidingly contacting a pair of rotary heads 15 and 16 that rotate at high speed, thereby performing predetermined recording and reproduction.

The traveling magnetic tape 4 is then sequentially wound by a winding reel 3 driven by a reel stand. Next, the rotary head drum 10 will be explained. As shown in FIG. 2, the rotary head drum 10 is formed into a flat cylindrical shape and is fixed to the upper end of a rotating shaft 17.

A fixed drum 18 having the same diameter as the head drum 10 is disposed under the head drum 10 in an overlapping manner. The outer peripheral surface of this fixed drum 18 is covered with magnetic tape 4.
It constitutes the information surface. A casing 19 is disposed below the fixed drum 18, and the casing 19 fixedly supports the fixed drum 18. Bearings 20 and 21 are respectively supported on the fixed drum 18 and the casing 19, and these bearings 20 and 21 rotatably support the rotating shaft 17. A brake core 22 is fixed to the lower part of the rotating shaft 17, and an electromagnetic brake 23 is attached to the outer periphery of the core 22.
are arranged. The core 24 of this electromagnetic brake 23 extends in a horseshoe shape so as to sandwich the brake core 22 therebetween.
Further, a pulley 25 is disposed below the brake core 22 and is fixed to the rotating shaft 17. Rotational force is transmitted from a motor (not shown) through this pulley 25, and the rotating shaft 17 is driven to rotate at a high speed, for example, 1800 rpm. Rotary magnetic heads 5 and 16 for video are attached to a rotary head drum 10 which is rotationally driven by this rotary shaft 17.

That is, as shown in FIG.
Recesses 26 and 27 are formed by counterbore in the lower end surface of the , and support pieces 28 are provided in these recesses 26 and 27, respectively.
, 29, magnetic heads 15, 16 are attached. And in the installed state, the heads 15, 16
The tip of the rotary head drum 10 slightly protrudes from the outer peripheral surface of the rotary head drum 10. Therefore, when the heads 15, 16 and the magnetic tape 4 come into sliding contact, the magnetic layer of the magnetic tape 4 is scraped off and the magnetic powder that falls off adheres to the front end surfaces of the heads 15, 16, causing damage to the video signal. adversely affect recording and playback,
Otherwise, troubles such as recording and reproduction becoming impossible are likely to occur. Therefore, in this TR, the fallen magnetic powder is blown away with air. That is, as shown in FIGS. 2, 4, and 5, a pair of air collectors 30 and 31 are disposed inside the rotary head drum 10.

These air collectors 30, 31 are formed in a substantially wrapper shape, and openings 32, 33 for taking in air are located in the direction of rotation of the rotary head drum 10. Therefore, when the rotary head drum 10 rotates counterclockwise as shown in FIG. 4, the air flow 34 is introduced into the air collectors 30, 31 through the openings 32, 33 relative to each other. Since the air collectors 30 and 31 are gradually constricted in a rattling shape, the kinetic energy of the air flow 34 is converted into pressure energy, and high-pressure air is attached to the base portions of the air collectors 30 and 31. The flow rate adjustment valves 35 and 36 are guided to the flow rate regulating valves 35 and 36. The flow rate adjustment valves 35 and 36 are constituted by, for example, rotary valves, and the amount of air blown onto the heads 15 and 16 is adjusted by inserting a screwdriver into the groove 37 of the valve stem and rotating it. It's becoming like that.
A pipe 38 is connected to the outlet side of these flow rate regulating valves 35 and 36.
, 39 are connected, and the air whose flow rate is adjusted by the flow rate regulating valves 35 and 36 is guided through these pipes 38 and blown onto the opposing portions of the magnetic heads 15 and 16 and the magnetic tape 4. To be able to do it. become.

Therefore, the magnetic tape 4 is pressurized by the air in the direction away from the magnetic heads 15, 16, which reduces the contact pressure of the magnetic tape 4 with the magnetic heads 15, 16, and reduces the shedding of the magnetic powder. Significantly decreased. Especially the magnetic head 15,1
Magnetic tape 4 and magnetic head 15 at the edge part of 6
, 16 is significantly reduced, and the magnetic heads 15, 16 are less likely to scrape off the magnetic layer of the magnetic tape 4 at the edge portions of the magnetic heads 15, 16. . Furthermore, even if the magnetic powder falls off due to the force of the magnetic layer, it will not adhere to the surfaces of the magnetic heads 15 and 16 because it will be blown away by the blown air.

Furthermore, since the magnetic heads 15 and 16 are constantly cooled by the air sent from the pipes 38 and 39, falling off of the magnetic powder is further prevented. Therefore, in this VTR, accidents such as magnetic powder falling off the surface of the magnetic tape 4 adhering to the surfaces of the magnetic heads 15 and 16 and having an adverse effect on the recording and reproduction of video signals, or making recording and reproduction impossible. will be effectively prevented. Next, a second embodiment of the present invention and FIG. 6 will be described.

The first embodiment described above is a two-head type V
Although this invention is applied to TR, the present invention is applicable to other VT.
This second embodiment is applicable to a 4-head type VTR. In this embodiment, the pipes 38 and 39 from the flow rate regulating valves 35 and 36 are branched into two pipes, respectively, and the air taken in by the air collector 30 is supplied to the heads 15a and 15b, and is also collected. The air taken in by the air device 31 is transferred to the heads 16a, 1.
6b.

Therefore, the VTR of this embodiment is also configured to effectively prevent clock phenomena. In this embodiment, instead of branching the pipes 38 and 39, it is also possible to provide four air collectors and blow air from these air collectors to the pipes 15a, 15b, 16a, and 16b, respectively. It is possible.

As is clear from the above, the present invention adjusts the flow rate of gas taken in from the gas intake means as the support of the rotary head rotates, and controls the adjusted gas by using the flow rate adjustment means. The gas is blown onto the contact area between the recording/reproducing head and the recording medium using a gas guide means.

Therefore, since the contact pressure of the recording medium against the recording/reproducing head can be adjusted to an optimal value, it is extremely easy to prevent the recording/reproducing head from scraping the surface of the recording medium and causing powder to adhere to the recording/reproducing head. With this configuration, it is possible to perform good recording and reproducing while effectively preventing the problem.

[Brief explanation of the drawing]

The drawings show an embodiment in which the present invention is applied to a VTR, in which FIG. 1 is a schematic plan view of the VTR of the first embodiment, FIG. 2 is a longitudinal sectional view of a rotating head drum device, and FIG. 3 is a schematic plan view of the VTR of the first embodiment. is the second
FIG. 4 is a plan view of the rotating head drum, FIG. 5 is a perspective view of the same, and FIG. 6 is a plan view of the main portion of the second embodiment. In addition, in the symbols used in the drawings, 4 is a magnetic tape, 10 is a rotating head drum, 15 and 16 are rotating heads, 30 and 31 are air collectors, 35 and 36 are flow rate regulating valves, and 38 are rotary heads.
, 39 are pipes.

Claims (1)

[Claims] 1. In a rotary head device of a recording/reproducing apparatus, the recording/reproducing head supported by a rotating support is configured to perform recording and/or reproduction while facing a recording medium,
The rotating support is provided with a gas intake means, a gas guide means for guiding the gas taken in by the gas intake means, and a flow rate adjustment means for adjusting the flow rate of the gas, and the rotation of the support The flow rate of the gas taken in from the gas intake means is adjusted by the flow rate adjusting means, and the gas is blown by the gas guiding means onto the opposing portion of the recording/reproducing head and the recording medium. rotating head device.