JPH0652501A - Rotary head device for magnetic recording and reproducing device - Google Patents

Abstract

PURPOSE:To reduce the occurrence of cross talk between recording signals supplied to a rotary head and reproduced signals from a rotary transformer without increasing the size of the transformer by absorbing leakage fluxes getting into fixed coils by means of an annular ring formed of a conductor installed to one of the recessed annular grooves of the fixed coils. CONSTITUTION:When recording signals are supplied to fixed recording signal transmitting coils 52a respectively fixed in the plurality of second annular recessed grooves 51 of a fixed core 49, a new magnetized track is formed on a magnetic tape and reproduced signals from a reproducing head 44, etc., are transmitted to a fixed reproduced signal transmitting coil 51a through a transmitting coil 53a. Under such condition, an annular ring 49b formed of a conductor installed to the third annular recessed groove 59a of the fixed core 49 absorbs leakage fluxes of the magnetic fluxes passing through the faces 51b and 52b of the core 49. Similarly, an annular ring formed of a conductor installed to the annular recessed groove of a rotary core 50 absorbs leakage fluxes of the magnetic fluxes passing through the counter faces 53b and 54b of the core 50.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention mainly relates to a magnetic recording / reproducing apparatus (hereinafter referred to as VT) for recording (or reproducing) a video signal on a magnetic tape.
Called R. ) Rotary head device.

[0002]

2. Description of the Related Art In recent years, VTRs have been downsized and high-density recording has been provided, and a rotary head device having a structure for recording a high frequency signal by winding a magnetic tape around a fixed drum to rotate the rotary head at a high speed is provided. . A conventional example will be described below with reference to the drawings.

FIG. 5 is a sectional view of a conventional rotary head device, FIG. 6 is an enlarged sectional view of a rotary transformer incorporated in the conventional rotary head device, and FIG. 7 is a side view of the conventional rotary head device. FIG. 8 and FIG. 8 are plan views of the essential parts of a VTR incorporating a conventional rotary head device. A rotary head 1 can reproduce a recording signal from the magnetic tape 32. Two
The rotary head 1 is adhered and fixed to the tip end by a head base, and is fixed to the lower end of an annular rotary drum 15 with screws 3.
Reference numeral 4 denotes an annular fixed upper drum around which a magnetic tape is wound around the outer peripheral surface 4a. A fixed lower drum 5 is provided with a lead 5a for helically regulating the running height position of the magnetic tape wound under the annular outer peripheral surface 5b. A rotary disk 6 is fixed to the rotary shaft 7 and is rotatably supported by bearings 8 and 8'formed in the center of the fixed lower drum 5.
Reference numeral 9 is a thrust stopper fastened to the lower end of the rotary shaft 7 with a screw 10, 11 is a rotor of the electric motor fastened to the thrust stopper 9 with a screw 12, and 13 is a magnet adhesively fixed to the rotor 11 of the electric motor. , 14 are stator coils of the electric motor, which generate a rotational force in the rotor 11 when energized. Reference numeral 16 is a screw for fastening and fixing the rotary drum 15 to the rotary disk 6, and 17 is a rotary side core of a flat plate type rotary transformer which is adhered or fixed to a lower portion of the rotary disk 6, and is 180 with respect to the rotary head 1 and the rotary head 1. Rotating coils 17a ', 17c' for transmitting recording (or reproducing) signals to each of the rotary heads 1'separated from each other.
Are bonded and fixed to the concave groove portions 17a and 17c. 1
Reference numeral 7b denotes a concave groove portion provided in an intermediate portion between the concave groove portions 17a and 17c, which is a short ring 1 of a conductor that absorbs a leakage magnetic flux mixed into the rotating side coils 17a 'and 17c'.
7b 'is adhesively fixed. Reference numeral 18 denotes a fixed side core of a flat plate type rotary transformer which is fixed to the inside of the fixed lower drum 5 so as to face the rotation side core 17 of the rotary transformer, and the fixed side coils 18a 'and 18c' are provided in the concave groove portions 18a and 18c.
Are glued and fixed. 18b is a concave groove portion 18a, 1
A short ring 18b 'made of a conductor is adhered and fixed by a concave groove portion provided in the middle portion of 8c. Reference numeral 19 is a slip ring fitting fixed to the upper end of the rotary disk 6 with a screw 21 via a spacer 20, and 22 is a slip ring holder for insulatingly holding the electrodes 23, 24, 23e, 24e of the slip ring, It is adhesively fixed to the ring fitting 19. 25, 26, 25
e, 26e are electrodes 23, 24, 23 of the slip ring
The brushes 27 and 27 are in contact with the brushes 25, 26, 25e, and 26e. The brush holders insulate and hold the brushes 25, 26, 25e, and 26e. Reference numeral 29 is a circuit board fixed to the upper part of the rotary drum 15, and 31 is a preamplifying means formed on the circuit board 29, which individually amplifies the reproduction signals from the rotary heads 1 and 1 ', and It joins the rotating side coils 17a 'and 17c' of the rotating side core 17. Reference numeral 42 denotes a fixed drum connecting member, and the outer peripheral surface of the fixed upper drum 4 and the outer peripheral surface of the fixed lower drum 5 are fastened and fixed with screws 43, 43 '.

Next, 32 is a magnetic tape which is a tape guide 3
3, an erasing head 34, a tape guide 35, rotary heads 1 and 1 ', and a rotary head device in which an outer peripheral surface of the fixed upper drum 4 and an outer peripheral surface of the fixed lower drum 5 are fixed by a fixed drum connecting member 42, Tape guide 36, audio
Each of the control head 37 and the capstan 38 is guided to form a tape running path. 39 indicates a pinch roller.

Next, the operation of the conventional example shown in FIGS.
When TR is set to the recording mode, the electric motor stator coils of 14 are energized to generate a rotational force in the rotor 13, and the thrust stopper 9, the rotary shaft 7, the rotary disk 6, and the rotary transformer fixed to the rotor 13 rotate. The parts of the side core 17, the rotary drum 15, the rotary heads 1, 1 ', etc. fixed to the rotary shaft rotate in the direction of arrow 40. Then, Capstan 38
If the pinch roller 39 is pressed while rotating the magnetic tape 32 with the magnetic tape 32 sandwiched between the magnetic tape 32 and the pinch roller 39, the magnetic tape 32 starts to run in the direction of the arrow 41 by the cooperation of the capstan 38 and the pinch roller 39.

When a recording signal is applied to the rotary heads 1, 1'through the rotary transformer, a new magnetized track is formed on the magnetic tape. When the VTR is in the reproduction mode, + Vcc and GND power are supplied to the preamplifying means 31 through the brushes 25 and 26 in contact with the electrodes 23 and 24 of the slip ring, and the preamplifying means 31 is supplied.
Has reached the operating state, the reproduced signals from the rotary heads 1 and 1'are individually amplified and added to the rotary side coils 17a 'and 17c' of the rotary side core 17 of the rotary transformer, and the fixed side core 18 corresponding thereto is added. To the fixed side coils 18a 'and 18c', and is added to the subsequent signal processing circuit.

[0007]

In the rotary head device of the conventional example described above, the rotary core 17 of the rotary transformer is used.
And conductive short rings 17b 'and 18b' provided on the fixed core 18 and concave groove 17b, respectively.
In general, the structure of adhering and fixing to 18b and 18b, respectively. Recent VTRs include, for example, digital VTRs that record digital signals by A / D converting recording signals and high-quality VTRs.
Then, it is necessary to transmit the high frequency signal with the rotary transformer,
When the conventional rotary transformer is applied to these digital VTRs and high-definition VTRs, the rotary side coils 17a ', 1
7c 'and the fixed side coils 18a', 18c 'mix leakage magnetic fluxes by the short rings 17b', 18b ', so that the action is reduced, and the recording signal supplied to the rotary head and the reproduction from the rotary transformer. This has led to an increase in signal crosstalk. As a means for solving this problem, a conventional measure for increasing the pitch intervals of the rotating side coils 17a ', 17c' and the fixed side coils 18a ', 18c' and a measure for increasing the cross-sectional area of the short rings 17b ', 18b'. Is common. However, these countermeasures lead to an increase in the size of the rotary transformer, which causes new problems such as preventing the rotary head device from being downsized.

The present invention solves the conventional problems and provides a rotary head which reduces crosstalk between a recording signal supplied to the rotary head and a reproduction signal from the rotary transformer without increasing the size of the rotary transformer. To aim.

[0009]

A rotary head that contacts a magnetic tape, a rotary core formed with a plurality of first concave annular shapes, and a rotary head fixed to the bottom surface of a first concave annular groove of the rotary core. A rotary coil for transmitting a signal and a first rotary core
A plurality of second concave annular grooves arranged to face the concave annular groove and a third concave annular shape having an enlarged cross-sectional area with respect to the second concave annular groove in the middle of the plurality of second concave annular grooves. Magnetic recording / reproducing apparatus comprising: a fixed core having a groove formed therein; a fixed coil fixed to the bottom surface of the second concave annular groove of the fixed core; and an annular ring of a conductor disposed in the third concave annular groove. The rotary head device.

[0010]

According to the present invention, with the above structure, the fixed coil fixed to the bottom surfaces of the plurality of second concave annular grooves of the fixed core and the bottom surface of the plurality of first concave annular grooves of the rotating core are fixed. When performing signal transmission with the rotating coil, the annular ring of the conductor arranged in the third concave annular groove of the fixed core acts to absorb the leakage magnetic flux mixed between the fixed coil and the rotating coil. .

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the rotary head device according to the present invention will be described below with reference to FIGS. The parts not related to the present invention have the same numbers and the same reference numerals as those in the conventional example shown in FIGS.

FIG. 1 is a sectional view of a rotary head device of an embodiment according to the present invention, FIG. 2 is a detailed sectional view of a rotary transformer incorporated in a rotary head device of an embodiment of the present invention, and FIG. FIG. 4 is a side development view of a drum connecting member included in a rotary head device according to an embodiment of the present invention, and FIG. 4 is a plan view of a main part of a VTR incorporating the rotary head device according to the embodiment of the present invention.

Reference numerals 43 and 43 'are recording heads, and 44 and 44'.
Indicates a reproducing head, which is fixed to the lower end of an annular rotary drum 45 with a screw 3. An annular fixed upper drum 46 has a magnetic tape wound around the outer peripheral surface 46a. Reference numeral 47 is a fixed lower drum, and is provided with a lead 47a for helically regulating the running height position of the magnetic tape wound around the annular outer peripheral surface 47b. 47c is a screw 4 on the bottom of the fixed lower drum 47.
7b shows an annular body clamped and fixed at 7b. 48 is screw 4
Reference numeral 8'denotes a circuit board fixed to the upper portion of the rotary drum 45, and the preamplification means 31 formed on the circuit board 48 amplifies a reproduction signal from the reproduction head 44.

Reference numeral 49 denotes a fixed core of a cylindrical rotary transformer that is adhesively fixed inside the annular body 47c, and 50 is a rotary core of a cylindrical rotary transformer that is adhesively fixed to the rotary disk 6. Reference numerals 51 and 52 denote a plurality of second concave annular grooves formed in the fixed core 49 of the cylindrical rotary transformer, and the reproduction signal transmission fixed coil 51a and the recording signal transmission fixed coil 52a are adhesively fixed to the bottom surfaces of the concave annular grooves. ing. 53,
Reference numeral 54 denotes a plurality of first concave annular grooves formed in the rotary core 50 of the cylindrical rotary transformer, and the reproduction signal transmitting rotary coil 53a and the recording signal transmitting rotary coil 54a are adhesively fixed to the bottom surfaces of the concave annular grooves. Reference numerals 51b and 52b denote facing surfaces of the fixed core 49 of the cylindrical rotary transformer, and the facing surfaces 53b and 54b of the rotary core 50 of the cylindrical rotary transformer are formed with the gap 1 interposed.

49a is disposed in the middle of the plurality of second concave annular grooves 51 and 52 of the fixed core 49, and has a third concave shape whose cross-sectional area is enlarged with respect to the second concave annular grooves 51 and 52. An annular groove is shown, and an annular ring 49b of a conductor is adhered and fixed. 50 a is disposed in the middle of the plurality of first concave annular grooves 53 and 54 of the rotary core 50, and the first concave annular groove 5 a
3, 54 shows a concave annular groove having an enlarged cross-sectional area, which is arranged so as to face the third concave annular groove 49a of the fixed core 49, and an annular ring 50b of a conductor is adhesively fixed. The annular rings 49b and 50b of the conductor are fixed cores 49.
Facing surfaces 51b and 52b of the rotor and the facing surface 53 of the rotating core 50
Absorbs the leakage of magnetic flux passing through each of b and 54b.

Reference numeral 55 denotes a thrust stopper fixed to the lower end of the rotary shaft 7 with a screw 10, and 56 denotes a rotor of an electric motor fixed to the thrust stopper 56 with a screw 12.
Reference numeral 57 is a frequency generating annular magnet that is adhered or fixed to the outer periphery of the end of the rotor 56, 58 is a main magnet that is adhered and fixed to the inside of the rotor 56, and 59 is a screw 60 that is an annular body 4.
A stator iron is wound around a stator core of an electric motor fixed to the end of 7c. Reference numeral 61 denotes a wiring board of the electric motor fixed to the spacer 62. On the outer peripheral side, a frequency generating pattern coil for facing the frequency generating annular magnet 57 and converting a change in the rotating magnetic flux of the frequency generating annular magnet 57 into an electric signal is provided. It is configured.

Reference numeral 63 denotes a main magnet rotation phase detector fixed to the wiring board 61 of the electric motor so as to face the end portion of the main magnet 58. The main magnetic rotation phase detector 63 converts the magnetic flux change due to the rotation of the main magnet 58 into an electric signal, and outputs the electric signal of the electric motor. The energization of the stator coil wound around the stator core 59 is sequentially switched to generate a rotational force in the rotor 56.

The stationary lower drum 47 and the annular body 47c are assembled by the rotation center of the rotating shaft 7 supported by the bearings 8 and 8'disposed on the annular body 47c and the outer peripheral surface 47b of the stationary lower drum 47.
It is tightened and fixed with a screw 47d so as to match the center of the.

Reference numeral 64 denotes a fixed drum connecting member, which includes a first drum fixing portion 64a 'having a first drum fixing surface 64a for fixing the outer peripheral surface 47b of the lower fixed drum 47 and a first drum fixing surface 64a. On the other hand, as shown in FIG. 4, the outer peripheral surface 46a of the fixed upper drum 46 is fixed at a position biased in the direction in which the ratio of the magnetic tape 32 wound around the outer peripheral surface 46a of the fixed upper drum 46 decreases. Drum fixed surface 6
And a second drum fixing portion 64b 'formed with 4b, and is fixed to the outer peripheral surface 47b of the fixed lower drum 47 with a screw 65, and the outer peripheral surface 46a of the fixed upper drum 46 is clamped and fixed with a screw 65'. There is. Reference numeral 66 denotes a reinforcing member for the fixed upper drum which is fastened and fixed to the fixed drum connecting member 64 and the fixed upper drum 46 with screws 67 and 68.
When replacing the rotary drum 45 due to wear of 3, 43 'and the reproducing heads 44, 44' and checking the operation of the preamplifying means 31, the screws 65 ', 67 are removed and the fixed upper drum 46 and the reinforcing member 66 are unitized. It is a structure for performing work.
The fixed part contact area of the outer peripheral surface 47b of the fixed lower drum 47 with respect to the first drum fixed surface 64a of the drum connecting member 64 and the fixed part contact area of the outer peripheral surface 46a of the fixed upper drum 46 with respect to the second drum fixed surface 64b are Made almost identical,
The outer peripheral surface 47b of the lower fixed drum 47 is configured to maintain the mechanical position accuracy of the outer peripheral surface 46a of the upper fixed drum 46.

Reference numeral 69 denotes a cylindrical rotary head cleaner which comes into contact with each of the recording heads 43 and 43 'and the reproducing heads 44 and 44' to remove deposits. The rotary head cleaner 69 includes the recording heads 43 and 43 'and the reproducing head 4.
4, 44 ′ are the second members of the fixed drum connecting member 64.
Of the tape traveling path which is divided by the rotary head device after passing through the drum fixing surface 64b of the magnetic tape 32 from the side where the number of windings of the magnetic tape 32 around the outer peripheral surface 46a of the fixed upper drum 46 increases. The rotary head cleaner 69 is disposed close to the outer circumference of the rotary head device in the section of the tape traveling path where the magnetic tape 32 starts to contact, and a part of the rotary head cleaner 69 is located above the first drum fixing surface 64a of the fixed drum connecting member 64. The outer peripheral surface 47b of the fixed lower drum 47 and the outer peripheral surface 46a of the fixed upper drum 46 are opposed to each other. Then, the rotary head cleaner 69 is sucked toward the outer peripheral surface of the rotary head device by a suction operation by energizing the solenoid 70, and is brought into contact with each of the recording heads 43, 43 'and the reproducing heads 44, 44' passing therethrough. Reference numeral 71 denotes a rotary plate of the rotary head cleaner 69. When the cutout portion 72 is sucked by the suction portion pin of the solenoid 70, the rotary head cleaner 69 is rotated about the rotary shaft 73, and the rotary head cleaner 69 is indicated by a broken line 69 '. Move to the position shown. 74 is a stopper pin of the rotating plate 71,
Reference numeral 75 is a coil spring wound around the rotary shaft 73,
It is regulated by the first spring hook portion 71 ′ and the stopper pin 74. Reference numeral 76 denotes a rotary head cleaner cover disposed around the rotary head cleaner 69, and reference numeral 77 denotes a cleaner support shaft for rotatably supporting the rotary head cleaner 69.

As shown in FIGS. 3 and 4, reference numeral 78 denotes an annular lower drum 4 formed by a second drum fixing portion 64b 'of the drum connecting member 64 and an outer peripheral surface 47b of the annular lower drum 47.
7, a second tape guide which is partially disposed in the outer space area of the outer peripheral surface 47b of the outer peripheral surface 47b and divides the magnetic tape path from the first tape guide 36 'to the upper annular drum 46, and the outer peripheral surface of the upper annular drum 46. The magnetic tape 32 separated from 46a is wound around the second tape guide 78, and the traveling height position is regulated by the first tape guide 36 '. Reference numeral 79 denotes a tape guide forming a tape traveling path from the capstan 38.

Next, the operation of this embodiment will be described with reference to FIGS. Magnetic tape 3 on the rotary head device
In the process of winding 2, the energization of the stator coil wound around the stator core 59 of the electric motor is sequentially switched to generate a rotational force in the rotor 56 to rotate the rotary drum 45, and the recording heads 43, 43 'and Playback heads 44,44 '
Rotates in the direction of arrow 40, and the magnetic tape 32 is wound around the tape guide 33, the erasing head 34, the tape guide 35, the rotary head device, the tape guides 78 and 36 ', the audio control head 37, and the capstan 38, respectively. When the formation of the tape running path is completed, the capstan 38 is rotated, the magnetic tape 32 is sandwiched between the capstan 38 and the pinch roller 39, and the pinch roller 39 is pressed by the capstan 38 and the pinch roller 39. Start running in the direction.

Then, when a recording signal is supplied to the recording signal transmitting fixed coil 52a fixed to each of the plurality of second concave annular grooves 51 of the fixed core 49, each of the plurality of concave annular grooves 54 of the rotary core 50 is supplied. The recording signal is transferred to the recording heads 43 and 4 via the recording signal transmission rotary coil 54a.
3 ', a new magnetized track is formed on the magnetic tape 32, and the reproduction signals from the reproduction heads 44 and 44' are amplified by the preamplifying means 31 to reproduce the reproduction signal transmitting rotary coil 5.
3a and is transmitted to the reproduction signal transmission fixed coil 51a. In this state, the third concave annular groove 4 of the fixed core 49
An annular ring 49b made of an electric conductor arranged on 9a absorbs the leakage of magnetic flux passing through the facing surfaces 51b and 52b of the fixed core 49. Similarly, the annular ring 50b made of a conductor arranged in the concave annular groove of the rotating core 50 absorbs the leakage of magnetic flux passing through the facing surfaces 53b and 54b of the rotating core 50.

[0024]

As described above, according to the present invention, the fixed coil fixed to the bottom surface of the plurality of second concave annular grooves of the fixed core and the bottom surface of the plurality of first concave annular grooves of the rotating core are provided. In the case of transmitting a signal with the fixed rotating coil, the annular ring of the conductor arranged in the third concave annular groove of the fixed core absorbs the leakage magnetic flux mixed into the fixed coil and the rotating coil. Therefore, it is possible to reduce the crosstalk between the recording signal supplied to the rotary head and the reproduction signal from the rotary transformer without increasing the size of the rotary transformer, which can contribute to the spread of this type of VTR.

[Brief description of drawings]

FIG. 1 is a sectional view of a rotary head device according to an embodiment of the present invention.

FIG. 2 is a detailed sectional view of a rotary transformer incorporated in the rotary head device.

FIG. 3 is a side development view of a drum connecting member included in the rotary head device.

FIG. 4 is an enlarged sectional view of a rotary transformer built in the rotary head device.

FIG. 5 is a sectional view of a conventional rotary head device.

FIG. 6 is an enlarged sectional view of a rotary transformer incorporated in the rotary head device.

FIG. 7 is a side view of the rotary head device.

FIG. 8 is a plan view of a main part of a VTR incorporating the rotary head device.

[Explanation of symbols]

43,43 'recording head 44,44' reproducing head 46 annular fixed upper drum 47 fixed lower drum 49 fixed core of cylindrical rotary transformer 50 rotary cores 51,52 of cylindrical rotary transformer 2 concave annular groove 51a reproduction signal transmission fixed coil 52a recording signal transmission fixed coil 51b, 52b facing surface of fixed core of cylindrical rotary transformer 49a third concave annular groove 49b formed in fixed core annular ring 53 of conductor , 54 a plurality of first concave annular grooves 53a formed in the rotary core 53a reproduction signal transmitting rotary coil 54a recording signal transmitting rotary coils 53b, 54b facing surface of the rotary core of the cylindrical rotary transformer 50a concave annular formed in the rotary core Groove 50b annular ring of conductor

Claims (1)

[Claims] 1. A rotary head that contacts a magnetic tape, a rotary core formed with a plurality of first concave annular grooves, a rotary core fixed to the bottom surface of the first concave annular groove of the rotary core, and a signal to the rotary head. A rotating coil for transmitting and a first of the rotating core
A second concave annular groove and a second concave annular groove which are arranged to face the concave annular groove of
Fixed core having a third concave annular groove having a cross-sectional area enlarged with respect to the second concave annular groove in the middle of the concave annular groove, and fixed to the bottom surface of the second concave annular groove of the fixed core. Rotary head device for a magnetic recording / reproducing apparatus, comprising: a fixed coil and an annular ring of a conductor disposed in the third concave annular groove.