JPH02139701A - Rotating head device for magnetic recording and reproducing equipment - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention mainly relates to a rotary head device for a magnetic recording/reproducing apparatus (hereinafter referred to as a VTR) for recording (or reproducing) video signals on a magnetic tape.

Conventional technology Traditionally, VTR rotary head devices have a configuration in which the reproduced signal from the rotary head is applied to a secondary rotary transformer that rotates together with the rotary head, and then is applied from a corresponding fixed secondary side to the VTR preamplifier. was common. In recent years VTR
As image quality continues to improve, rotary head devices have been provided that are equipped with a recording head and a reproducing head, and transmit recording and reproducing signals using dedicated rotary transformers for each to improve reliability. ing.

A conventional example will be described below using drawings.

FIG. 4 shows a cross-sectional view of a conventional rotary head device, in which 1 is a reproducing head, and 1 is the reproducing head 1! A magnetized track recorded on a magnetic tape (not shown) is scanned with a reproducing head 1' (not shown) provided at a distance of 8°,
A playback signal can be output. Reference numeral 2 denotes a reproducing drum base, the reproducing head 1 is adhesively fixed to the tip thereof, and the reproducing head 1 is fixed to the lower end of the rotating drum 4 with screws 3. 4a is rotating drum 4
A reproducing head protruding window 5 is provided on the outer circumferential surface of the fixed lower drum, and the magnetic tape can be guided on the outer circumferential surface of the fixed lower drum.

Reference numeral 6 denotes a rotating disk, which is fixed to a hollow rotating shaft 7 at the center and is rotatable by being supported by bearings 8 and 8'.

Reference numeral 9 indicates a through hole provided at the center of the hollow rotating shaft 7.

Next, 10 is a thrust stopper fixed to the lower end of the hollow rotating shaft 7 with a screw 11, and 12 is a thrust stopper 10.
．． Tighten with screw 13 on the rotor of the fixed electric motor, 1
4 is a rotor magnet that is adhesively fixed to the rotor 12 of the electric motor, and 15 is a stator coil of the electric motor. When energized, rotational force is generated in the rotor magnet 14. 16 is screw 1
The motor cover 18 which is fastened and fixed to the fixed lower drum 5 at 7 is a fixed core of a power supply type rotary transformer which is adhesively fixed to the motor cover 16, and is wound with a fixed coil that supplies power from the outside. Reference numeral 19 denotes a rotating core of a power supply type rotating transformer which is adhesively fixed to the rotor 12 of the electric motor via a shield plate 19', and around which a rotating coil is wound. 20 is a screw that tightens and fixes the rotating drum 4 to the rotating disk 6; 21 is a secondary 111 rotating core of a recording rotating transformer adhesively fixed to the lower surface of the rotating disk 6;
A tangent side rotating coil is provided for transmitting a recording signal to a recording head (not shown).

Reference numeral 22 denotes a primary fixed core of the recording rotary transformer, which is adhesively fixed inside the fixed lower drum 5 via a shield plate 22'', facing the secondary core 21 of the recording rotary transformer, and applies a recording signal from the outside. A primary fixed coil is provided. Reference numeral 23 denotes a regenerative rotary transformer mounting tool which is fastened to the rotary drum 4 with screws 24, and a secondary rotary core 25 of the regenerative rotary transformer is adhesively fixed thereto. Reference numeral 26 denotes a primary fixed core of the regenerative rotary transformer, which is provided on the upper side corresponding to the secondary rotary core 25 of the regenerative rotary transformer.
It is adhesively fixed to the reproduction rotary transformer holder 27.

The secondary rotating core 25 and the secondary fixed core 26 are respectively provided with a secondary rotating coil and a secondary fixed coil for transmitting reproduction signals from the reproduction heads 1 and I', respectively. 28 is a regenerative rotating transformer holder mounting tool which is fixed to the outer periphery of the lower drum 5 with a screw 29, and 30 is a regenerative rotating transformer holder mounting tool 28 which is fastened to the regenerative rotating transformer holder 27. Indicates the screw to be used.

Next, 31 and 31' are preamplifiers configured on the top side of the rotating drum 4. When power is supplied, the preamplifiers become operational, inputting the playback signals from the playback heads 1 and 19, and amplifying them individually. , is added to the secondary rotating coil provided in the secondary rotating core 25 of the regenerative rotating transformer. 32 is a rotating disk 6
The AC signal rectifier circuit installed on the top of the unit rectifies the input AC signal and supplies power to the preamplifier. Reference numerals 33 and 339 indicate lead wires that are guided from the secondary rotating coil of the power supply type rotating transformer to the through hole 9 of the hollow rotating shaft 7 and connected to the AC signal rectifying circuit 32.

Next, the operation of the conventional rotary head device shown in FIG. 4 will be explained.

When the VTR is put into operation, the motor stator coil 15
is energized, a rotational force is generated in the rotor magnet 14, and the thrust stopper 10, which tightens and fixes the rotor magnet 14, the hollow rotating shaft 7, the rotating disk 6, and the secondary rotating core 21 of the recording rotating transformer. , secondary rotating core 25 of the reproducing rotary transformer, rotating drum 4, reproducing head 1
．． A portion fixed to a hollow rotating shaft 7 such as 1' rotates.

Further, in the preamplifier, an AC signal applied to the fixed coil of the primary fixed core 18 of the power supply type rotary transformer is transmitted to the rotating coil of the secondary rotating core 19, and the lead wire 3
3.33' is supplied to the AC signal rectifier circuit 32,
It is rectified and reaches the operating state. Then, when a recording signal is supplied from the fixed coil on the primary side of the recording rotary transformer, a magnetic flux is generated from the recording head (not shown) by being applied to the recording head, and a new magnetized track is formed on the magnetic tape. A reproduction signal is obtained from the reproduction heads 1, 1' corresponding to the magnetized track formed by the recording head. The reproduction signal from the reproduction head 1, 1'' is sent to the preamplifier 31, 31'.
It is transmitted to the secondary rotating coil provided in the secondary rotating core 25 of the amplification and regeneration rotating transformer, and is output to the primary fixed coil of the corresponding primary fixed core 26, and the subsequent Participates in signal processing circuit.

Problems to be Solved by the Invention However, in the conventional rotary head device described above, the regenerative rotary transformer is attached by attaching the tool 23 to the rotary drum 4 with the screws 2.
Since the configuration is such that the tightening is fixed in step 4, playback head 1,
When replacing the rotary drum 4 due to wear of the rotary drum 1' and the recording head, it is necessary to remove the tool 23 from the rotary drum 4 in order to install the reproducing rotary transformer, which complicates the removal and assembly process and reduces the efficiency of the rotary drum replacement work. It was causing this.

In addition, in recent years, VTRs have become more advanced in recording high frequencies; for example, NT
High-quality VT with approximately twice as many horizontal scanning lines as SC video signals
The rotary head device in a digital VTR that A/D converts R or NTSC video signals and records them digitally on magnetic tape can record and play back a high frequency that is 4 to 5 times higher than the recording frequency of a conventional rotary head device. is required to do so.

In these conventional rotary head devices that are compatible with high-frequency recording and reproduction, due to the influence of the rotational surface wobbling of the rotary drum 4, rotational surface wobbling also occurs in the secondary rotating core 25 of the reproducing rotary transformer. It becomes difficult to accurately set the gap (g) between the secondary rotating core 25 and the primary fixed core 26. Therefore, gaps (
g) is expanded and the transmission characteristics of the regenerative rotary transformer are deteriorated, which has the disadvantage of reducing the credibility of the reproducing signal, such as increasing the high frequency loss of the reproducing signal.

SUMMARY OF THE INVENTION An object of the present invention is to provide a rotary head device for a magnetic recording/reproducing device that eliminates the conventional drawbacks, improves the workability of replacing and assembling the rotary head, and enables a reproducing rotary transformer with less rotational surface wobbling. do.

Means for Solving the Problems The present invention fixes the rotating core of a rotating transformer, and has a guide hole provided at one end of the center portion and a concave groove extending outward from the guide hole. a rotary disk having a rotary head fixed to the outer periphery thereof and a rotary core fixing surface for fixing the rotary core fixing member of the rotary transformer; a first through hole in the center; a hollow rotating shaft having an end in which a second through hole is disposed outward from the hole, and the second through hole of the hollow rotating shaft is disposed from the rotating core fixing surface of the rotating disk. The rotary core fixing member of the rotary transformer has a concave groove and a second through hole of the hollow rotary shaft are aligned with each other.

Effect The present invention has the above-described configuration, and in the process of assembling the rotating core fixing member and the rotating disk of the rotating transformer,
The outer peripheral surface of the end of the hollow rotating shaft protruding from the rotating core fixing surface of the rotating disk is guided through the guide hole provided in the rotating core fixing member of the rotating transformer, and the concave groove of the rotating core fixing member and the hollow rotating shaft are guided. The rotary core fixing member of the rotary transformer is tightened and fixed to the rotary disk by matching the second through hole provided in the rotary transformer with the second through hole provided in the rotary disk.

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 the same parts as in the conventional example shown in FIGS.

FIG. 1 shows a sectional view of the main parts of a rotary head device according to an embodiment of the present invention, in which 34 is a rotary drum, and a recording head (not shown) and a reproducing head 1.1' are provided on the outer peripheral surface of the drum. ing. A hollow rotating shaft 35 has a first through hole 36 in its center, and is rotatably supported by bearings 8, 8''.

37 is a rotating disk that is press-fitted and fixed to the upper part of the hollow rotating shaft 35, and the rotating drum 34 is tightened on the outer periphery by the fixing part 34.
Fix a with screws 20. 38 is a second through hole 39 disposed outward from the first through hole 36 at the upper end of the hollow rotating shaft 35 protruding from the rotating core fixing surface 37' of the rotating disk 37, that is, in the radial direction; is a rotary core fixing member of the regenerative rotary transformer that adhesively fixes the secondary rotary core 40 of the regenerative rotary transformer, and the outer diameter of the fixing portion 39' provided on the lower side is fixed to the rotary drum 34. The diameter is set to be slightly smaller than the inner diameter of the portion 34a. 4
Reference numeral 1 denotes a primary fixed core of the regenerative rotary transformer provided outside the secondary rotary core 40 of the regenerative rotary transformer, and is adhesively fixed to the regenerative rotary transformer holder 42. 4
Reference numeral 3 denotes a guide hole provided on the bottom surface of the rotary core fixing member 39 of the regenerative rotary transformer, which is fitted into and guided by the upper end of the hollow rotary shaft 35 protruding from the rotary core fixing surface 37' of the rotary disk 37. 44 is a concave groove provided between the guide hole 43 provided at the center of the rotating core fixing member 39 of the regenerative rotary transformer and the outer lead wire guide portion 45; 46 is the rotating core fixing member 39 of the regenerative rotary transformer. The screw is tightened to the rotating core fixing surface 379 of the rotating disk, and 47 is an AC signal rectifier circuit that is adhesively fixed to the top of the rotating disk 37, and the lead wire 48.48' is connected from the power supply type rotating transformer. The input AC signal is rectified to supply power to the preamplifiers 49 and 49'. The preamplifier 49.49' is brought into operation by the power supply;
Reproducing signals from the reproducing heads 1 and 1' are input and individually amplified, and the amplified signals are applied to a secondary rotating coil provided in a secondary rotating core 40 of a reproducing rotating transformer.

Next, FIGS. 2 and 3 respectively show perspective views of a rotating core fixing member, a rotating disk, and a hollow rotating shaft of a reproducing rotating transformer in a rotating head device according to an embodiment of the present invention. The rotating core fixing surface 37'' of the rotating disk 37 is integrally processed with respect to the hollow rotating shaft 35 so that surface wobbling does not occur.

34' is a rotating drum fixing surface for fixing the rotating drum, 20
a is a screw hole for fixing the rotating drum, 38' (not shown)
is a third through hole provided at a distance of 180 degrees from the second through hole 38, and 44' is provided at a distance of 180 degrees from the concave groove 44.
The spaced apart concave grooves 45' are the lead wire guide portions 4.
The lead wire guide portions provided at a distance of 180° with respect to No. 5 are shown respectively.

In addition, the lead wire 48.4 from the power supply type rotating transformer
8' is guided through the first through hole 36 of the hollow rotating shaft 35 to the second through hole 38 at the upper end, and is connected to the AC signal rectifier circuit 4.
It is wired to 7.

To assemble the rotary core fixing member 39 of the regenerative rotary transformer and the rotary disk 37, tighten the rotary core fixing member 39 of the regenerative rotary transformer by inserting the guide hole 43 provided in the fixing part 399 into the rotary core fixing surface of the rotary disk 37. 37'
The upper end portion of the hollow rotating shaft 35 protrudes from the upper end portion of the hollow rotary shaft 35 and is guided therethrough.

In this state, the rotating core fixing member 39 of the regenerative rotating transformer
Concave grooves 44, 44' provided between the guide hole 43 provided in the outer lead wire guide portion 45 and the hollow rotating shaft 35
The second through holes 38 and 38' of and,
Tighten the screws 4B and 4Ei guided to the screw guide holes 48b and 4B'b of the rotating core fixing member 39 of the regenerative rotary transformer into the screw holes 48a and 4B'a of the rotary disk 37 to fix the rotating core fixing member of the regenerative rotary transformer. The tightening of 39 brings the fixing portion 39'' and the rotating core fixing surface 37' of the rotating disk 37 into tight contact, thereby completing the assembly work.

As described above, according to this embodiment, the rotating core fixing member 3
9 is fitted and guided by the hollow rotating shaft 35, so that the rotational surface wobbling of the rotating core 40 is reduced and the signal transmission characteristics of the rotating transformer are improved.

Effects of the Invention As described above, according to the present invention, there is no need to remove the rotating core fixing member of the regenerative rotary transformer from the rotating disk in the process of replacing the rotating drum, and it is possible to improve the work efficiency of replacing the rotating drum. be. In addition, high frequency recording
If implemented in a rotary head device of a high-quality VTR or digital VTR compatible with reproduction, the guide hole of the rotary core fixing member to which the rotary core of the reproducing rotary transformer is fixed will be inserted into the upper end of the hollow rotary shaft protruding from the rotary disk. Since it is assembled by fitting together, the rotational surface wobbling of the rotating core is reduced.

Therefore, it is possible to precisely set the gap between the secondary rotating core and the primary fixed core of the regenerative rotating transformer.
It is possible to improve the reliability of the reproduced signal, such as by improving the transmission characteristics of the regenerative rotary transformer and reducing the high frequency loss of the reproduced signal.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of the main parts of a rotary head device according to an embodiment of the present invention, FIG. 2 is a perspective view of a rotating core fixing member of the regenerative rotary transformer, and FIG. 3 is a view of the rotary disk and hollow rotating shaft. 4 is a sectional view of a conventional rotary head device. 1.1'... Reproducing head, 34... Rotating drum, 35... Hollow rotating shaft, 36... First through hole, 37... Rotating disk, 38. (38')
... second through hole, 39 ... rotary core fixing member of regenerative rotary transformer, 43 ... guide hole of rotary core fixing member, 44. (44')--concave groove, 45. (45')...Lead wire guide section,
48+48'...Lead wire, 49.49'
...Preamplifier.

Claims (1)

[Claims] A rotary core fixing member for the rotary transformer that fixes the rotary core of the rotary transformer and has a guide hole provided at one end of the center portion, a concave groove extending outward from the guide hole, and a rotary head fixed to the outer periphery. , a rotating disk having a rotating core fixing surface for fixing the rotating core fixing member of the rotating transformer, a first through hole in the center, and a second through hole extending outward from the first through hole. a hollow rotating shaft having an end portion provided with a second through hole, the end portion of the hollow rotating shaft having a second through hole protruding from the rotating core fixing surface of the rotating disk; A rotary head device for a magnetic recording/reproducing device, characterized in that a concave groove of the rotary core fixing member and a second through hole of the hollow rotary shaft are aligned with each other.