JPH01178103A - Rotary head type magnetic recording and reproducing device - Google Patents

Abstract

PURPOSE:To increase the resonance frequency and to obtain a characteristic of high transmission rate and broad band by mounting a circuit package with at least part of a recording and reproducing circuit in the inside of a rotary drum provided thereto into the inside of a supporting base supporting a magnetic head removed from a rotary drum. CONSTITUTION:The package 12 with the circuit mounted thereto is assembled in the inside of a magnetic head chip supporting base 16, the magnetic head winding is connected to the supporting base 16 and connected to the circuit via the circuit package 12 side terminal. Thus, the magnetic head 5 and the reproduction are made approached and the resonance characteristic of the magnetic head is not affected by the inductance, distribution capacitance of a rotary transformer and the capacitance of a connection cable. Thus, a high resonance frequency required to realize broad band high transmission rate is easily obtained.

Description

[Detailed Description of the Invention] [Object of the Invention] (Industrial Application Field) The present invention relates to a rotary head type magnetic recording and reproducing device such as a VTR, and particularly to a recording and reproducing device suitable for a wideband, high transmission rate recording and reproducing device. Regarding circuit mounting methods.

(Prior art) In recent years, current television systems (NTSC, PAL, SE
We are researching and developing digital VTRs that convert television signals (such as CAM, etc.) into digital signals for recording and playback, and analog VTRs or digital VTRs for high-definition television that have significantly higher resolution than the current television system. It's happening everywhere.

These VTRs require a much wider bandwidth and higher transmission rate than conventional VTRs that record and reproduce current television system signals up to analog signals, and as a result, the recording density becomes extremely high. As a result, various problems arise.

172 inch home VT for NTSC television signals
Taking R as an example, the recording and playback band is 500KHz to 7MH
z/ICH, and such conventional home VTRs
As schematically shown in FIG. 5, recording and reproduction are performed using FM signals. That is, the video signal input is modulated by the FM modulator 27, amplified by the recording circuit section in the recording/reproducing circuit 28, and supplied to the magnetic head 31 via the step-hub transformer 29 and the rotary transformer 30.
It is recorded on magnetic tape 32. The signal recorded on the magnetic tape 32 is reproduced by the magnetic head 31, passed through the rotary transformer 30 and the step-up transformer 29, and amplified by the reproduction circuit section in the recording and reproduction circuit 28.
The M demodulator 33 demodulates the signal.

As shown in Figure 6a, the transmission frequency characteristics of the electromagnetic conversion system in magnetic recording are such that the output power decreases in the high frequency range, so F
For M transmission, it is necessary to perform frequency compensation using the opposite characteristics. Generally, the magnetic head 31 shown in FIG.
This compensation is performed using the resonance characteristics of , and a flat transmission frequency characteristic as shown in FIG. 6C is obtained. The resonance characteristics of the magnetic head 31 are determined by the sum of the input capacitance Ci and the distributed capacitance Cs of the reproduction circuit and the inductance Lh of the magnetic head 31. If the step-up ratio of the step-up transformer 29 is n, the resonance frequency fr is fr=1. /2πnJLh(Ci+Cs), that is, the inductance of the magnetic head 31 cannot be changed significantly because it greatly affects the inductance of the lead wire and the S/N of the reproduced output.

Therefore, in order to increase the resonant frequency, the input capacitance of the regeneration circuit and the number of windings of the rotary transformer 30 must be reduced.
This type of method requires a recording and playback band more than 10 times wider than the normal digital VTR and VTR for high-definition television signals (hereinafter collectively referred to as wideband/high transmission rate VTR). It is not compatible with most VTRs.

Since the resonant frequency is generally set to a higher frequency than the highest frequency of the recording/reproduction signal band, in order to realize a wideband/high transmission rate VTR, it is necessary to avoid intervening a rotary transformer between the magnetic head and the reproduction circuit. It is desirable to do so.

This is because the inductance and distributed capacitance of the rotary transformer and the capacity of the connecting cable to the magnetic head impede a wide band and high transmission rate. Therefore, an attempt has been made to widen the playback band by incorporating a playback circuit into the rotating drum and connecting the playback circuit and the magnetic head without using a rotary transformer (References: Reports of the Institute of Electrical Communication Engineers) MR85-54).

However, when the reproducing circuit is built into the rotary drum in this manner, the following problem arises regarding the connection between the windings of the magnetic head chip and the reproducing circuit when the magnetic head chip is mounted on the magnetic head base.

■ The lifespan of the magnetic head of a rotating head type VTR is approximately 1
000 to 2000 hours, and in commercial applications such as broadcast station production houses, it is necessary to frequently replace the head.

However, the magnetic head mounting method described above requires soldering when replacing the head, making it impossible to easily replace the head.

■ In broadband/high transmission rate VTRs, the rotational speed of the rotating drum is 2 Orpm compared to 180 Orpm for normal VRTs.
Double 360Orpm, or 5400rpm or 7
Since the rotation speed is as high as 200 rpm, the centrifugal force applied to the circuit and magnetic head inside the drum for one rotation is approximately 1000 G or more, and the internal components of the rotating drum vibrate due to this high-speed rotation. In the magnetic head mounting method described above, a connector is used to connect the magnetic head board and the reproduction circuit, so there is a risk that the contact state of the connector may deteriorate due to centrifugal force or vibration caused by the high-speed rotation of the rotating drum. Yes, and lacks reliability.

■ A wideband, high transmission rate VTR uses at least six magnetic heads, including one for normal playback and one for special playback. For example, a D-1 format 525 digital VTR (
For example, in an NTSC television digital VTR (digital VTR), 16 magnetic heads are used. (Reference: Television Society Report VR87-5).

On the other hand, when rotating the rotary drum at high speed, the diameter of the rotary drum cannot be increased too much due to size limitations of the entire recording/reproducing apparatus and mechanical safety. For this reason, a number of reproducing circuits corresponding to the number of magnetic heads must be mounted in a narrow space on the rotating drum. As mentioned above, in rotary head type magnetic recording and reproducing devices such as broadband and high transmission rate VTRs in which a conventional reproduction circuit is installed in a rotating drum, the head must be replaced frequently, and the reliability is sufficient for the high-speed rotation of the single-rotation drum. However, there was a problem in that it was difficult to implement it within a one-rotation drum.

The present invention solves these problems and has a structure in which at least a part of the recording/reproducing circuit is provided within the one-rotation drum.
The rotating head type magnetic head is easy to replace, has high electrical and mechanical reliability against centrifugal force and vibration caused by high-speed rotation of the rotating drum, and has a simple structure inside the rotating drum, making it easy to implement. The purpose is to provide a recording/playback device.

In the present invention, at least a part of the recording/reproducing circuit, that is, a circuit provided with the recording circuit, the reproducing circuit, or both, is mounted on a package, and the package is configured to be removably attached inside the support base that supports the magnetic head chip. Ru. Connectors for electrical connection are provided inside the package on which one circuit is mounted and the support base, respectively. Furthermore, the windings of the magnetic head are connected to terminals on the support base side and connected to the circuit via terminals on the circuit package side.

(Function) In the configuration of the present invention, a package carrying a circuit is incorporated inside a magnetic head chip support base, and the magnetic head winding is connected to a terminal on the support base side and connected to the circuit via a terminal on the circuit package side. As a result, the magnetic head and the reproducing circuit can be brought close to each other, and the resonance characteristics of the magnetic head are no longer affected by the inductance of the rotary transformer, the distributed capacitance, the capacitance of the connecting cable, etc., which makes it possible to achieve a wide band and high transmission rate. It is easy to obtain the high resonant frequency required for

The magnetic head is replaced by replacing the magnetic head support base. If the built-in circuit is not damaged at that time, the circuit package is replaced from the old support base to the new support base.If the circuit is broken and needs to be replaced, the circuit package is taken out from the support base and replaced.

Further, since the circuit package is built into the support base, heat generated by the circuit operation is radiated to the package, the support base, and the rotating drum that fixes the support base, which is efficient.

Since the circuit is built into the support base of the magnetic head, the structure inside the rotating drum is simple and implementation is easy.

(Embodiment) FIG. 1 is a sectional view showing a schematic configuration of a scanner section of a rotary head type magnetic recording/reproducing apparatus (VTR) according to a first embodiment of the present invention. In the figure, a scanner section 1 is fixed to a pace 2 of a VTR main body with bolts 3. VT
A videotape (not shown) sent out from a tape transport (not shown) of R is wound around the rotating drum 4 and travels, while coming into contact with the tip of the magnetic head 5 protruding from the surface of the rotating drum 4. The one-rotation drum 4 is driven by a drive motor 6. The drive motor 6 is the rotating drum 4
It is controlled to rotate at a predetermined rotation speed by a servo circuit (not shown) based on a signal from a rotary encoder 7 that detects the rotation speed.

A rotor encoder 7 is attached to the rotation center shaft 8 of the drive motor 6.
A rotary transformer 9 is installed above the rotary transformer 9. Further, a slip ring 10 is provided below the rotary transformer 9. The rotary transformer 9 is connected to the control circuit board 1 provided in the rotation speed drum 4 via a signal line (not shown) passing inside the rotation center shaft 8.
1, and the slip ring 10 is connected to the inside of the rotating drum 4 via a power supply line (not shown) that also passes inside the rotation center shaft 8, and is located below the control circuit board 11 and the board ll. Recording and reproducing circuit package 1 installed in
Connected to 2.

FIG. 2 shows the main parts of FIG. 1 in detail, and the control circuit board 11 and the recording/reproducing circuit package 12 are
3, and the connector 13 is integrated with the support base 16 by a fixing screw 21. The control circuit board 11 is attached to the rotating drum 4 by screws 14 for fixing the board.
It is removably installed inside.

On the other hand, the recording/reproducing circuit package 12 is detachably attached inside the support base 16. The support base 16 has a tongue portion 17 in a portion located in the window on the circumferential surface of the rotating drum 4, and the magnetic head 5 is supported on this tongue portion 17. The winding 18 of the magnetic head 5 is directly connected to a terminal 19 on the support base side by soldering or wire bonding. Tongue portion 17 of support base 16 for magnetic head chip
The IC mounted on the circuit package 12 is located at the base of the
A groove 20 is formed as a thermal isolation region to prevent heat generated by a chip (not shown) from being transmitted to the magnetic head 5.

In the rotary head type magnetic recording/reproducing device configured in this way, when recording information signals such as video signals,
An information signal is input to the stator side of the rotary transformer 9 and output from the rotor side.

Information signals output from the rotor side are supplied to the control circuit board 11 in the rotating drum 4 via a signal line passing through the rotation center shaft 8. The control circuit board 11 controls the recording/reproducing circuit package 12 , and information signals input to the control circuit board 11 are transmitted to the recording/reproducing circuit package 12 via the connector 13 .

A recording circuit in the recording/reproducing circuit package board 12 amplifies the information signal, supplies a recording current to the magnetic head 5, and records information on the magnetic tape that is in sliding contact with the magnetic head 5. Reproduction is performed by the magnetic head 5, and the information signal obtained from the magnetic head 5 is amplified by a reproduction circuit in the recording and reproduction circuit package 12. The amplified information signal is once sent to the control circuit board 1 via the connector 13.
1, and further transmitted to the rotor side of the rotary transformer 9 via a signal line within the rotation center shaft 8, and led out from the stator side to the outside of the scanner 1.

In addition, the power required for the operation of the circuits in the control circuit board 11 and the recording/reproducing circuit package 12 is
0 through a power line passing through the rotation center shaft 8. Here, since the magnetic head 5 is mounted on a recording/reproducing circuit package 12 in which a circuit is mounted,
Although it is necessary to take into account the effect of heat generated by the circuit, since the tongue portion 17 on which the magnetic head 5 is mounted is thermally separated from the area on which the circuit is mounted by the groove 20, such an effect cannot be avoided. can be kept to a minimum.

Next, a procedure for replacing the magnetic head 5 will be explained.

First, the control circuit board 11 fixed inside the rotating drum is released by the board fixing screws 14, and the board 11 is pulled out of the rotating drum 4.6 When the control circuit board 1 is pulled out of the rotating drum 4, , the screws 15 fixing the support substrate 16 containing the recording/reproducing circuit package 12 are exposed. Therefore, by removing this fixing screw 15 and releasing the fixation of the support base 16, the magnetic head 5 and the connector 13 fixed to the support base 16 containing the recording/reproducing circuit package 12 and its tongue piece 17 can be separated into one. The rotary package 12 is taken out to the outside. Then, by reversing the procedure described above, the support base 16 containing the recording/reproducing circuit package 12 with a new magnetic head 5 attached thereto is installed inside the rotary drum 4, and further controlled. The circuit board 11 is connected to the rotating drum 4
The head replacement is completed by attaching the board 11 to the connector 13 and connecting the board 11 to the connector 13. Note that the magnetic head 5 is positioned using the fixing screw 15 of the recording/reproducing circuit package 12.
This is done by adjusting the

In this way, the magnetic head 5 can be replaced by a simple procedure that does not involve complicated operations such as soldering.

If the recording/reproducing circuit needs to be replaced due to a failure, the control circuit board is pulled out of the rotating drum and the support base 16 containing the recording/reproducing circuit package 12 is fixed in place, as in the case of replacing the magnetic head.

Remove the fixing screw 15 and release the fixation of the support base 16. Since the recording/reproducing circuit package 12 is fixed to the supporting base 16 by fixing screws 21 and connectors 13, the fixing screws 21 are released and the recording/reproducing circuit package 12 is removed from the supporting base 16.

Thereafter, the recording/reproducing circuit package 12 can be replaced by attaching the support base 16 to which the new recording/reproducing circuit package 12 is attached into the rotary drum 4 in the reverse order as described above, and connecting the board 11 to the connector 13. finish.

In this way, the recording/reproducing circuit package 12 can be replaced by a simple procedure that does not involve complicated operations such as soldering, similar to the replacement of the magnetic head.

As mentioned above, the rotating drum of a wideband/high transmission rate VTR rotates at high speed. Therefore, when a connector or the like is used inside the rotating drum, the structure and arrangement must take centrifugal force and vibrations into consideration.

FIG. 3 shows a cross section of the magnetic head and recording/reproducing circuit package shown in FIG. 2. The winding 18 of the magnetic head 5 is connected to a fixed terminal 19 which is coated with gold plating or the like to ensure good contact.

The connection with the recording/reproducing circuit package 12 is through this fixed terminal 1.
9 and a movable contact 22 with spring properties fixed to the recording/reproducing circuit package 12. On the other hand, the connector 13 and the recording/reproducing circuit package 12 are connected to each other on the recording/reproducing circuit package 12 side with the fixed terminal 23 which is treated with gold plating or the like in order to make good contact with the fixed terminal 19 on the connector 13 side. This is done by a movable contact 24 with spring properties. Since the centrifugal force acts from the center of the rotating drum 4, that is, from the direction B to the outer peripheral side A of the rotating drum 4, the magnetic head 5 and the recording/reproducing circuit package 12 side are connected to the movable contact 22.
is attached to the fixed terminal 19 due to its own springiness and centrifugal force,
Maintaining a Stronger Contact State 6 Similarly, the movable contact 22 on the connector 1 and recording/reproducing circuit package 12 side maintains a stronger contact state with the fixed terminal 23 due to its own springiness and centrifugal force.

FIG. 4 shows the main part of the second embodiment of the present invention.
The recording/reproducing circuit package 25 is provided with a groove for replacement. By providing this groove, when replacing the recording/reproducing circuit package 25, the fixing screw 14 is removed and the control circuit board 11 is taken out from the rotating drum 4.
When it is pulled out of the rotating drum 4, the support base 16 containing the recording/reproducing circuit package 12 is exposed. Here, insert a pulling tool such as tweezers into the recording/reproducing circuit package 25.
The recording/reproducing circuit package 25 is pulled out using the groove 26 . and.

A new recording/reproducing circuit package is placed into the support base 16 using the groove 26. Thereafter, the control circuit board 11 is placed in the rotating drum 4 in the reverse order to the above, and the control circuit board 11 is fixed with the fixing screws 14. Compared to the first embodiment in which the support base 16 is unfixed, the method of this second embodiment eliminates the need for the support base 16 to be unsecured.

Note that the present invention can be implemented with various modifications without departing from the gist of the invention.6 For example, as described above, a plurality of magnetic heads are mounted in the rotating drum for normal playback and special playback. is common. For this reason, in wideband, high transmission rate VTRs and the like with high recording and reproducing frequencies, crosstalk between channels corresponding to each magnetic head becomes a major problem. In such a case, it is preferable to cover part or all of the recording/reproducing circuit package with a shielding member made of a metal material or a magnetic material. Providing such electromagnetic shielding is also effective in removing interference caused by noise entering from outside the rotating drum.

〔Effect of the invention〕

According to the present invention, the circuit package in which at least a part of the recording/reproducing circuit inside the rotating drum is mounted inside the support base supporting the magnetic head, which is removable from the rotating drum, allows the magnetic head and the reproducing circuit to This makes it possible to increase the resonant frequency and obtain broadband and high transmission rate characteristics, as well as facilitate head replacement by replacing the magnetic head chip along with the support base.

Since the circuit package is built into the support base via the connector, it can be easily replaced.

The connection between the magnetic head, recording/reproducing circuit package, and control circuit uses a connector structure that utilizes centrifugal force, which can cause poor contact, to strengthen the connection between the connectors. There is no connection failure caused by centrifugal force or vibration, improving electrical and mechanical reliability, and the structure inside the rotating drum is simpler, making it easier to implement even when the number of channels (number of heads) is large. It has the advantage of being easy.

[Brief explanation of the drawing]

Fig. 1 is a cross-sectional view of a part of the entire scanner showing an embodiment of the present invention, and Fig. 2 shows a magnetic head support base inside the scanner and a recording/reproducing device built into the support base, showing an embodiment of the present invention. FIG. 3 is an enlarged view showing the schematic structure of the circuit package; FIG. 3 is a sectional view of the magnetic head support base shown in FIG. 2 and the connector mechanism of the recording/reproducing circuit package built inside the support base; FIG. FIG. 5 is an enlarged view showing an outline of the mechanism of a magnetic head support base showing another embodiment and a recording/reproducing circuit package built into the support base; FIG. 5 is a block diagram showing an outline of the circuit configuration of a conventional home VTR; FIG. 6 is a characteristic diagram showing the frequency compensation process of recording and reproducing characteristics of a VTR. 5...Magnetic head 12...Recording/reproducing circuit package 13...Connector 16...Support base 19.23...Fixed terminal 22.24...
Movable terminal 26...Replacement groove agent Patent attorney Noriyuki Ken Yudo Matsuyama Mitsuyuki tat figure 3 figure 5 figure question line

Claims (2)

[Claims] (1) A rotating head comprising a rotating drum around which a magnetic table is wound, a magnetic head attached to the rotating drum, and a recording/reproducing circuit connected to the magnetic head and provided inside the rotating speed drum. type magnetic recording and reproducing device, a package is assembled in which at least a part of the recording and reproducing circuit is mounted inside a support base for a magnetic head chip that is removable from the rotating drum body, and has a connection connector mechanism that is removable from the inside of the support base. A rotary head type magnetic recording/reproducing device characterized by: (2) The rotary head type magnetic recording and reproducing apparatus according to claim 1, further comprising a package ejection groove in which the recording and reproducing circuit is mounted.