JPH0383257A - Rotary head device - Google Patents

Abstract

PURPOSE:To prevent an impact error by providing a recording medium pressing part by a spot coating respectively on the inlet port part and outlet port part of the tape like recording medium of a fixed guide drum. CONSTITUTION:Record and reproduction are performed by a magnetic head 14 fitted via a head base 13 to the lower face of a rotary drum 11 by opposing to the rotary drum 11 the magnetic tape wound around a fixed guide drum 12. Pressing parts 35, 36 are formed by a spot coating at the vicinities of the outlet port and inlet port sides of the magnetic tape of the fixed guide drum 12. The bearing between the magnetic tape and magnetic head 14 is reduced by such spot coating parts 36, 37, the free vibration of the magnetic tape is restrained thereby and a noise impact error can be prevented.

Description

[Detailed description of the invention]

FIELD OF INDUSTRIAL APPLICATION 1 The present invention relates to a rotary head device used in a helical scan type recording/reproducing device such as a VTR5DAT. The present invention relates to a device for recording and/or reproducing data.

[Summary of the Invention] In a rotary head device of a helical scan type recording/reproducing device such as a VTR or DAT, suppression portions are formed by spot coating at the portion where the magnetic tape enters and exits from the fixed guide drum, and these portions are suppressed. By pressing the magnetic tape with the suppressing section, the magnetic head is prevented from hitting the magnetic tape at the entry and exit portions and generating vibrations. K Prior Art 1 In a helical scan type recording/reproducing device, a magnetic tape is helically wound around the outer circumference of a drum, and a rotary head is made to scan diagonally over the magnetic tape, thereby performing predetermined recording and recording. /or playback. And while magnetic tape runs relatively slowly, the magnetic head rotates at high speed, so the entrance part of the fixed guide drum where the rotating head first comes into contact with the magnetic tape and the magnetic head contact the magnetic tape. The magnetic head hits the magnetic tape at the exit portion of the fixed guide drum that breaks contact with the magnetic tape, causing string vibrations in the magnetic tape, causing the magnetic tape to expand and contract, causing image disturbances. In order to suppress impact errors caused by the magnetic head of such a rotating head device, for example, Japanese Patent Laid-Open No. 58-654
In Japanese Patent No. 7, a small piece is provided near the tape exit side of a fixed guide drum so as to protrude radially from the tape guide surface, and the vibration of the magnetic tape is suppressed by this small piece. Further, in Japanese Patent Publication No. 61-22379, a squeeze plate substantially parallel to the magnetic tape is provided on the tape guide closest to the tape exit side of the fixed guide drum to suppress vibration of the magnetic tape. Further, in JP-A-62-132257, as shown in FIGS. 6 to 8, an uncut portion 3.4 is formed in a part of the tape guide surface partitioned by the glue portion 2 of the fixed drum 1. I try to do that. That is, uncut portions 3.4 are provided near the position where the magnetic tape leaves the fixed guide drum 1 when processing the lead 2, and these uncut portions 3.4 press the magnetic tape to suppress its vibration. That's what I do. [Problems to be solved by the invention] A small piece of Japanese Patent Application Laid-open No. 58-6547, and Japanese Patent Publication No. 61-2
The squeeze plate disclosed in Japanese Patent No. 2379 is expensive and is mainly used in commercial rotary head devices. In addition, if such small pieces or squeeze plates are provided, space will be required near the head drum device.
This may hinder miniaturization. For these reasons, these measures are inappropriate for consumer VTRs. The method of forming the uncut portion 3.4 by bulge processing as provided in Japanese Patent Application Laid-Open No. 62-132257 is applied not only to business-use VTRs but also to consumer-use VTRs. In order to enhance the effect of suppressing impact errors by such an uncut portion, it is preferable to provide the uncut portion 4 not only on the exit side of the magnetic tape with respect to the fixed guide drum but also on the inlet side. However, if the uncut portion 4 is also provided on the entrance side of the magnetic tape, the number of rotations during lead processing must be extremely reduced, which reduces the productivity of drum processing, resulting in increased costs. It will rise. The present invention has been made in view of these problems, and it is an object of the present invention to provide a rotary head device having impact error prevention means that is advantageous in terms of cost and free from space problems. . Means for Solving Problem K) The present invention provides an apparatus in which recording and/or reproduction is performed by bringing a tape-shaped recording medium wound around a fixed guide drum into contact with a rotating head. Pressing portions are provided by spot coating at the entrance and exit portions of the tape-shaped recording medium of the fixed guide drum, respectively, and the pressing portions press the tape-shaped recording medium.

[Effect]

Therefore, the pressing parts formed by spot coating press the tape-shaped recording medium at the entrance and exit parts of the fixed guide drum, so even if the head hits the tape-shaped recording medium at these parts, the tape-shaped recording medium will not be pressed. The recording medium no longer causes string vibration, and impact errors are suppressed.

【Example】

FIG. 4 shows the overall structure of a rotary head device according to an embodiment of the present invention, and this rotary head device includes a rotating drum 11 and a fixed drum 12. A magnetic head 14 is attached to the lower surface of the rotating drum 11 via a helad base 13, and this magnetic head 14 faces the outer peripheral surface of the drum 11. Further, the rotating drum 11 is fixed to a flange disk 15 via bolts 16. A rotor 18 of a rotary transformer 17 is attached to the lower surface of the flange disk 15. A main shaft 21 is inserted into the center hole of the flange disk 15 and fixed thereto. The main shaft 21 is rotatably supported by a pair of upper and lower bearings 22 and 23 attached to the fixed drum 12. A stator 24 of a rotary transformer 17 is attached to the lower surface of this fixed drum 12.
It is facing 8. Further, a printed circuit board 25 is fixed to the lower part of the fixed drum 12. A motor 26 is arranged below the printed circuit board 25, and its stator yoke 27 is fixed to the fixed drum 12. A coil 28 is wound around the stator yoke 27. A magnet 29 is disposed so as to face the outer circumference of the stator yoke 27 and is rotatably supported by the rotor yoke 30. Note that the rotor yoke 30 is supported by the main shaft 21 via a preload ring 31. In the above configuration, the lower edge of the magnetic tape running at a predetermined speed is guided by the lead 32 provided on the outer peripheral surface of the fixed drum 12. By energizing the coil 28 of the motor 26 in this state, the rotating drum 11 is driven to rotate via the main shaft 21 and the flange disk 15. Therefore, the magnetic head 14 supported by the drum 11 via the head base 13 comes into contact with the magnetic tape, thereby performing recording and/or reproducing in the helical scan method. The rotating magnetic head 14 sends and receives signals to and from the stationary side via an 0-Tari transformer 17. Next, a device for forming a pressing portion at a predetermined position on the rotating drum 11 will be explained. FIG. 5 shows a device for forming such a pressing part, and this device is equipped with a vacuum container 37, and a drum mounting jig 38 is provided above the container 37. There is. The rotating drum 11 is supported and rotated by this jig. Further, a crucible 39 is disposed at the bottom of the container 37, and the coating material is filled into the crucible 39. Further, a heater 40 is arranged on the outer circumferential side of the crucible 39, and an ionization grid 41 is provided above the crucible 39 and on the inner circumferential side of the heater 40. An accelerating electrode 42 is provided above this grid 41. And the jig 38, Luppo 39, heater 4
0. The grid 41 and the accelerating electrode 42 are controlled by a controller 43, or alternatively, are driven by power from the controller 43. After cutting the upper drum 11 of the rotary head drum device shown in FIG. 4, the pressing portion 35 is cut by the device shown in FIG.
36 are formed. The apparatus shown in FIG. 4 is a vacuum deposition apparatus using ion blasting, in which evaporated particles of the coating material in the crucible 39 are turned into plasma and deposited on the outer peripheral surface of the drum 11. In consideration of the deformation of the drum 11, the temperature inside the vacuum container 37 is set to 200° C. or less. The coating material used in this apparatus may be titanium nitride (TiN), titanium carbide (TiC), Alx (Abu 203), or the like. Such coating material is stored in the 39,
A positive voltage is applied by controller 38. Then, while being heated by the heater 40 and being vapor deposited,
It is ionized by the ionization grid 41 and accelerated by the acceleration electrode 42. The accelerated particle ions are blown upward and attached to the outer peripheral surface of the rotating drum 11. Note that the rotational speed of the drum 11 at this time is, for example, 3 to 15 rpm, and oxygen, argon, or the like is used as the atmospheric gas in the vacuum container 37. Moreover, the degree of vacuum inside the container 37 is 1×10-3~1X
It is set to about 10-'. By such a vacuum deposition method, pressing portions 35 and 36 are formed by spot coating near the exit and entrance sides of the magnetic tape of the fixed guide drum 12. Such a spot coating part 35.3
6 reduces the surface pressure between the magnetic tape and the magnetic head 14, thereby suppressing free vibration of the magnetic tape, thereby suppressing impact errors. The structure of the pressing part using such spot coating will be explained in more detail. FIG. 1A is a developed plan view of the fixed drum 12 of a VTR without any means for preventing impact errors. In FIG. 1B, instead of the uncut portion 3.4 due to the bulge processing shown in FIG. 6B, spot coating is applied to the exit and entrance portions of the magnetic tape by plasma spraying, respectively. A suppressing portion is formed by these spot coating portions. By adjusting the film thickness of the coating portions 35, 36, it is possible to optimize the vibration regulation of the magnetic tape. In the case of a consumer VTR in which the width of the magnetic tape is 1/2 inch, a film thickness of, for example, about 30 to 50 .mu.- is appropriate. In this way, in the rotating head device related to the present case,
Spot coating is applied to the fixed guide drum 12 near the magnetic tape exit and entrance sides, and the pressing portion 35.
36 is formed to suppress impact errors caused by the magnetic head 14. Therefore, it is cheaper than using a 1-chip or squeeze plate, and it is convenient to handle because the fixed drum itself is spot-coated in advance. Further, a portion for suppressing impact errors can be provided on both the exit side and the entrance side of the magnetic tape of the fixed drum 12, and there is no space problem at all. When performing bulge processing on the fixed drum 12 as in the past, it is relatively easy to process the bulge only on the exit side of the magnetic tape. In other words, in the case of an NG lead processing machine, this can be done by changing the program, and in the case of a cam type machine, this can be done by replacing the cam. However, in order to form an uncut portion also on the entrance side, it is necessary to extremely reduce the rotational speed during lead machining. In view of these problems, spot coating is very advantageous. That is, since spot coating is performed using equipment separate from the NG lead processing machine, there is no need to change the program for each model or replace the cam.

【Effect of the invention】

As described above, in the present invention, pressing parts are installed by spot coating at the entrance and exit parts of the tape-shaped recording medium of the fixed guide drum, and the tape-shaped recording medium is pressed by these pressing parts. . Therefore, impact errors are prevented by the pressing portion formed by spot coating. Moreover, since the pressing portion can be formed on the fixed guide drum by simply welding it later, the drum can be provided at a low cost and there is no problem in terms of space.

[Brief explanation of drawings]

FIG. 1 is an exploded front view of a fixed guide drum of a rotary head device according to an embodiment of the present invention, and FIG.
~ll1lIli side view, Figure 3 is ■~■ in Figure 2
4 is a vertical sectional view showing the overall structure of the rotary head device, FIG. 5 is a vertical sectional view of a vacuum evaporation device for spot coating, and FIG. 6 is a development of a conventional fixed guide drum. The front view, FIG. 7 is a cross-sectional view taken along the line ■ to ■ in FIG. 6, and FIG. 8 is a cross-sectional view taken along the line ■ to ■ in FIG. The names of the main parts in the drawings are as follows. 11... Rotating drum 12... Fixed drum 14... Magnetic head 32... Lead

Claims (1)

[Claims] 1. In an apparatus in which a tape-shaped recording medium wound around a fixed guide drum is brought into contact with a rotary head for recording and/or reproduction, the inlet portion of the tape-shaped recording medium of the fixed guide drum and A rotary head device characterized in that a pressing portion is provided at each outlet portion by spot coating, and the pressing portion presses the tape-shaped recording medium.