JPS63214902A - Rotary head device for magnetic recording and reproducing device - Google Patents

Abstract

PURPOSE:To supply a stable power source to a rotating recording and reproducing amplifier by providing a cylindrical magnet rotor which can rotate unitedly with the recording and reproducing amplifier and an AC signal generating unit which generates an AC signal by applying a current. CONSTITUTION:In an action state, the current is applied in a stator coil driving circuit 51 and the AC signal generator 50 so as to sequentially apply the current in plural stator coils 35. By means of rotary fluxes from the plural stator coils 35, a rotating force occurs in a magnet rotor 36 and a part enclosed with a short dashes line 63 rotates. And the AC signal is generated in the AC signal generating unit 50 and added to a primary side fixed coil 42 of a power source supply type rotary transformer, then transmitted to a secondary side rotary coil 39 as the AC signals (P). The AC signal (P) is added to a AC signal rectifier circuit 48, rectified, stabilized in a specified DC voltage (V) and outputted from +Vcc and GND terminals so as to be supplied to the power source of the recording and reproducing amplifiers 59 and 60. Thus, the AC signal for the power source supply is not intermixed, so that high quality can be attained.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention mainly relates to a magnetic recording and reproducing device W1 (hereinafter referred to as VTR) that records (or reproduces) video signals on a magnetic tape.
The present invention relates to a rotating head device.

Conventional technology Conventionally, a VTR rotary head device inputs a reproduced signal from a rotating rotary head to a primary-side rotary transformer that rotates together with the rotary head, and then transmits a reproduction signal from a corresponding fixed secondary side to a VTR preamplifier. A common configuration was to add In recent years, VTRs have become more densely recorded and have higher image quality, and rotary head devices have been provided in which a preamplifier and a recording amplifier are built into the rotary head device, and the rotary head device is directly connected to and rotated. The conventional example is shown in Figures 4 and 5 below.
Describe using diagrams.

FIG. 4 shows a cross-sectional view of a conventional rotary head device, in which 1 is a rotary head capable of reproducing recorded signals from a magnetic tape (not shown). Reference numeral 2 is a helad base, and the rotary head 1 is adhesively fixed to the tip thereof, and is fixed to the lower end of the rotary cylinder 4 with screws 3. 5 is a fixed lower cylinder capable of guiding a magnetic tape on its outer peripheral surface. Reference numeral 6 denotes a rotating disk, which is fixed to a rotating shaft 7 at the center and is rotatable by being supported by bearings 8 and 8'.

9 is a thrust stopper fixed to the lower end of the rotating shaft 7 with a screw 10; 11 is a rotor of an electric motor fixed to the thrust stopper 9 with a screw 12; 13 is glued to the rotor 11 of the electric motor. The fixed magnet 14 is a stator coil of an electric motor, and when energized, rotational force is generated in the rotor 11. 15 is a spacer between the rotating disk 6 and the bearing 8; 16 is a screw that tightens and fixes the rotating cylinder 4 to the rotating disk 6; 17 is the primary core of the rotating transformer adhesively fixed to the lower part of the rotating disk 6. Then, recording (
(or reproduction) A primary winding for transmitting a video signal is provided in the groove. 18 is the primary core 17 of the rotating transformer
The secondary core of the rotating transformer is adhesively fixed to the inside of the fixed lower cylinder 5 opposite to the lower cylinder 5, and a secondary winding is provided in the groove. Reference numeral 19 denotes a slip ring mounting tool which is fastened to the upper end of the rotary disk 6 with a screw 21 via a spacer 20, and 22 an electrode 23 of the slip ring.
This is a slip ring holder that insulates and holds the slip ring 24, and the slip ring attachment is fixed to the tool 19 with adhesive. 25.2
Reference numeral 6 denotes a brush corresponding to and in contact with the electrodes 23 and 24 of the slip ring. Reference numeral 27 denotes a brush holder for insulating and holding the brushes 25 and 26. The brush attachment of the VTR body is adhesively fixed to a plate 28.

29 is a circuit board fixed to the upper part of the rotary cylinder 4 with screws 30, and 31 is a preamplification means configured on the circuit board 29, which individually amplifies the reproduced video signals from the rotary head 1.1'. , is added to the primary winding of the primary core 17 of the rotating transformer.

Next, FIG. 5 shows a wiring diagram of the main parts of a conventional rotary head device, in which the reproduced video signal from the rotary head 1.1 is applied to a preamplification means 31, and predetermined signal processing is performed. , is added to the primary windings 17a and 17b provided in the groove of the primary core 17 of the rotating transformer, is output to the secondary winding 18as18b provided in the groove of the secondary core 18 of the rotating transformer, and is output to the following Participates in signal processing circuit. The power source for operating the preamplifier means 31 is provided by the brushes 25.25, which are in contact with the electrodes 23.24 of the slip ring.
+Vc-c and GND are respectively supplied through 26. The part surrounded by a broken line 32 in FIG. 5 rotates together with the rotary cylinder 4, and the area outside the broken line 32 indicates a fixed part.

Next, the operation in the conventional example shown in FIGS. 4 and 5 is that when the VTR is put into the playback state, the 14 electric motor stator coils are energized, a rotational force is generated in the rotor 13, and a thrust stop is applied to the rotor 13. The parts fixed to the rotating shaft 7, such as the tool 9, the rotating shaft 7, the rotating disk 6, the primary core 17 of the rotating transformer, the rotating cylinder 4, the rotating head 1.1', and the electrodes 23, 24 of the slip ring, rotate. . Then, +Vcc and G
When the ND power is supplied, the preamplifier 31 enters the operating state, and individually amplifies the reproduced video signals from the rotary heads 1 and 1', thereby transmitting the primary windings 17a and 17b of the primary core 17 of the rotary transformer. It is output to the secondary windings 18a and 18b of the secondary core 18 corresponding to this, and is added to the subsequent signal processing circuit.

Problems to be Solved by the Invention As described above, in the conventional rotary head device described above, the power source for operating the preamplifier means 31 is connected to the brushes 25 . 26
Because of the structure in which the slip ring is supplied through the VTR, in the playback state of the VTR, the slip ring electrode 23.24 also rotates together with the rotary head 1.1', and the brush 25.26 comes into rotational contact with the slip ring electrode 23.24. It turns out. Therefore, during long-term playback of the VTR, the rotating slip ring electrodes 23, 24 and the brush 25.
The contact part with the slip ring electrode 23 may wear out, or dirt and dust in the air may adhere to the contact part.
．． 24 and the brushes 25 and 26 changes, which makes it impossible to provide stable power supply to the preamplifier means 31, resulting in a decrease in the reliability of the VTR. In addition, in recent years, VTRs have become more densely recorded, such as high-quality VTRs that have about twice as many horizontal scanning lines as NTSC video signals, and digital VTRs that convert NTSC video signals from analog to digital and record them digitally on magnetic tape. The rotating head device in
It is required to rotate at a high speed of 5 times or more.

When power is supplied to a rotary head device compatible with these high-speed rotations through contact between the slip rings 23 and 24 and the brushes 25 and 26, the slip ring 2
Since the brushes 3.24 and brushes 25 and 26 come into contact with each other in high-speed rotation, their wear time becomes even shorter, resulting in problems such as further deterioration of the reliability of the VTR. Conventionally, as a means to solve this problem, an AC signal rectifier is rotated together with a rotating head, and a rotating transformer is used to transmit the video signal to the preamplifier to transmit the AC signal outside the frequency band of the video signal. , the common countermeasure is to wash away the dust and add it. However, in this case, it becomes difficult to transmit large amounts of power, which limits the operation of the preamplifier, and the AC signal transmitted to the reproduced video signal mixes, reducing the S/N ratio of the reproduced video signal. This led to the occurrence of new problems such as:

SUMMARY OF THE INVENTION An object of the present invention is to eliminate the conventional problems and to enable a stable power supply to a rotating recording/reproducing amplifier connected to a rotary head.

Means for Solving the Problems A recording and reproducing amplifier connected to a rotating head and performing predetermined signal processing, a cylindrical magnet rotor that can rotate integrally with the recording and reproducing amplifier, and a cylindrical magnet rotor provided inside the magnet rotor. a stator coil that generates rotational force in the magnet rotor when energized; and a cylindrical secondary side 1 that is fixed to the outer periphery of the magnet rotor and rotates integrally with the magnet rotor.
A power supply rotary transformer that transmits an alternating current signal for supplying power to the recording/reproducing amplifier using a rotating coil and a corresponding cylindrical primary fixed coil; and a secondary side of the power supply rotary transformer. An AC signal rectifier connected to the rotating coil rectifies the input AC signal and applies its output to the power source of the recording/reproducing amplifier; and an AC signal rectifier connected to the primary individual fixed coil of the power supply type rotating transformer, This is a rotary head device for a magnetic recording and reproducing device, which is equipped with an AC signal generator that generates a signal.

According to the above-mentioned configuration, the present invention energizes the stator coil when the VTR is in use, generates rotational force in the magnet rotor to rotate the rotary head, winds a magnetic tape around the outer circumferential surface of the rotary head device, and generates an alternating current. The signal generator is energized and activated to generate an alternating current signal. In this state, an alternating current signal from the alternating current signal generator is applied to the primary fixed coil of the power supply type rotating transformer, and is transmitted to the secondary rotating coil. The transmitted AC signal is applied to an AC signal rectifier, where it is rectified and stabilized to a predetermined voltage and applied to the power source of the recording/reproducing amplifier.

Embodiment Below, one embodiment of the rotary head device according to the present invention is shown in Figs.
This will be explained in conjunction with Figure 3. Note that parts unrelated to the present invention are designated by the same numbers and symbols as those of the conventional example shown in FIGS. 4 and 5, and redundant explanation will be omitted. FIG. 1 shows a sectional view of a rotary head device according to an embodiment of the present invention, in which 33 is a hollow rotary shaft having a through hole 34 in the longitudinal direction of the shaft in the center, and a rotary disk 6 is fixed to the upper outer periphery. A thrust stopper 9 is tightened and fixed on the lower outer periphery with a screw 10. Reference numeral 35 denotes a plurality of stator coils, which are arranged to face each other inside a cylindrical magnet rotor 36 fixed to the a-tor 11 of the electric motor. When the plurality of stator coils 35 are sequentially energized, they generate a rotating magnetic flux and apply rotational force to the magnet rotor 36. A cylindrical secondary rotating core 37 is adhesively fixed to the outer circumference of the rotor 11, and a secondary rotating coil 39 is wound around an outer concave groove 38, so that it can rotate together with the rotor 11. Reference numeral 40 denotes a cylindrical primary fixed core that is adhesively fixed to the inner peripheral part of the motor cover 43 and placed opposite to the outer side of the secondary rotating core 37, and the primary fixed coil 42 is wound around the inner concave groove 41. has been done. The secondary side fixed coil 42 and the secondary side rotating coil 39 constitute a power supply type rotary transformer, and can transmit an alternating current signal for supplying power to a recording/reproducing amplifier to be described later.

44 and 45 are holders for regulating the height position of the primary fixed core 40; 46 is a holder for fixing a plurality of stator coils 35 and the motor cover 43;
and a magnetic shield for preventing the leakage magnetic flux generated from the power supply type rotary transformer of the secondary side fixed coil 42 and the secondary side rotating coil 39 from entering the rotating head etc., 47 is a motor cover 43 that is fixed by tightening it. The screw 48 is an AC signal rectifier circuit configured on a circuit board 49 fixed to the lower part of the rotor 11, and is connected to the secondary rotating coil 39 of the rotating transformer.
An AC signal transmitted through the converter is input, rectified by the rectifying action of a diode and a capacitor, stabilized to a predetermined DC voltage, and output as a power source for the recording/reproducing amplifier described later.

50 is an AC signal generator that generates an AC signal when energized, and its output is connected to the primary fixed coil 42 of the power supply type rotary transformer. 51 is a plurality of stator coils 3
A stator coil drive circuit is connected to 5 and sequentially switches energization. 52 is a shield plate provided at the bottom of the motor cover 43.

Reference numerals 53 and 54 denote primary rotating cores of a rotating transformer that is adhesively fixed to the lower part of the rotating disk 6 via a shielding material 55 and transmits recorded (or reproduced) video signals, and primary windings are provided in the grooves. ing. Reference numerals 56 and 57 indicate secondary fixed cores of the rotary transformer which are adhesively fixed to the inside of the fixed lower cylinder 5 via shielding material 58 in correspondence with the primary rotary cores 53 and 54 of the rotary transformer, respectively. are each provided with a secondary winding. 59
．． Reference numeral 60 denotes a recording and reproducing amplifier configured on a circuit board 62 which is fixed to the upper side of the rotary cylinder 4 with screws 61, and is activated when power from the AC signal rectifier circuit 48 is applied to the rotary head 1.1'. It is configured to supply a recording signal to the rotary head 1.1' and amplify a reproduction signal from the rotary head 1.1'. Next, FIG. 2 shows a detailed diagram of a power supply type rotating transformer comprising a cylindrical secondary rotating core 37 and a cylindrical primary fixed core 40 according to an embodiment of the present invention. The rotating coil 39 is wound around the bottom 38a of the outer concave groove 38,
- The next fixed coil 42 is located at the bottom 841 of the inner concave groove 41.
a and are each fixed with adhesive. Reference numeral 38a indicates a mounting surface guided to the outer circumferential portion of the rotor 11, and 40a indicates a mounting surface guided to the inner circumferential portion of the motor cover 43. The diameter and number of turns of the secondary rotating coil 39 and the secondary fixed coil 42 are set so that they can stably transmit the several watts of power required for the operation of the recording and reproducing amplifiers 59 and 60. Next, FIG. 3 is a wiring diagram of the main parts of a rotary head device according to an embodiment of the present invention, and shows the connection between the rotary head 1.1' and the recording and reproducing amplifiers 59 and 60, and the connection from the secondary side fixed coil 42. Disrupts the flow of AC signals. The part surrounded by the broken line 63 rotates together with the rotating cylinder 4, and the part surrounded by the broken line 63 rotates with the rotating cylinder 4.
The outside of is fixed.

Next, the operation of an embodiment of the rotary head device of the present invention will be described. When the VTR is put into operation, the stator coil drive circuit 51 and the AC signal generator 50 shown in FIG. Rotational force is generated at 36, causing damage to Figure 3 and 4.
The part surrounded by 1163 is rotated.

Further, an AC signal is generated from the AC signal generator 50, applied to the primary side fixed coil 42 of the power supply type rotating transformer, and transmitted to the secondary side rotating coil 39 as an AC signal (P). This AC signal (P) is applied to the AC signal rectifier circuit 48, where it is rectified by the rectification action of a diode and a capacitor, stabilized at a predetermined DC voltage (V), and +Vc c, GN
It is output from the D terminal and supplied to the power supply of the recording and reproducing amplifiers 59 and 60. Along with this, the recording and reproducing amplifier 5
9.60 reaches the operating state, and if the VTR is in the playback state, the playback video signal from the rotary head 1.1' is transferred to the playback amplifier 6.
The primary windings 53a, 5 of the rotating transformer are amplified individually at 0.
4a and corresponding secondary windings 56a, 57a
and is applied to the subsequent video signal processing circuit. Also,
When the VTR is in the recording state, the recording video signal from the rotating transformer is amplified by the recording amplifier 59, and the rotating head 1.1'
will be added to each.

Effects of the Invention As described above, according to the present invention, it is possible to completely eliminate the problems of the conventional configuration in which power is supplied to the preamplification means through rotational contact between the slip ring electrode and the brush. The reproduced video signal from the rotary head can be of high quality without being mixed with an AC signal for power supply, and can contribute to improving the reliability of the VTR. Furthermore, similar effects can be obtained even when the present invention is applied to a high-speed rotary head device such as a high-quality VTR or digital VTR.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a rotating head device according to an embodiment of the present invention, FIG. 2 is a detailed view of a power supply type recirculating transformer composed of a secondary rotating core and a primary fixed core, and FIG. This figure is a wiring diagram of the main parts of the rotary head apparatus, FIG. 4 is a sectional view of the conventional rotary head apparatus, and FIG. 5 is a wiring diagram of the main parts of the rotary head apparatus. 1.1'...Rotating head, 4...Rotating cylinder, 11...Rotor of electric motor, 33...Hollow rotating shaft, 39L...Secondary side of power supply type rotating transformer Rotating coil, 42... Power supply type rotating transformer - next side fixed coil, 48... AC signal rectifier circuit, 50...
... AC signal generator, 51 ... stator coil drive circuit, 59 ... recording amplifier, 60 ... reproducing amplifier. Name of agent: Patent attorney Toshio Nakao and one other person Figure 1 1.1'-One rotation, de 41-One concave X
Edition? -12 doss 42--Primary fjltl wing coil S-ruder
Heart--a Ming 1 Xing 3rd figure L----1 + + + +++
++-轡-j23.24-Slip ring! 1 Ward 2 Fu 26-Plan

Claims (1)

[Claims] A recording/reproducing amplifier connected to the rotating head and performing predetermined signal processing; a cylindrical magnetic rotor that can rotate integrally with the recording/reproducing amplifier; and a cylindrical magnetic rotor that is provided inside the magnetic rotor and rotates when energized. A stator coil that generates force, a cylindrical secondary rotating coil that is fixed to the outer periphery of the magnet rotor and rotates integrally with it, and a corresponding cylindrical primary fixed coil provide power to the recording and reproducing amplifier. a power supply rotary transformer that transmits AC signals to supply
an AC signal rectifier connected to the secondary rotating coil of the power supply type rotary transformer, which rectifies the input AC signal and applies its output to the power supply of the recording/reproducing amplifier; 1. A rotary head device for a magnetic recording/reproducing device, comprising: an AC signal generator connected to a side fixed coil and generating an AC signal when energized.