JPS58179903A - Magnetic recorder and reproducer - Google Patents

Abstract

PURPOSE:To reproduce individually the outputs of many magnetic heads with a small number of coils with high quality, by feeding selectively the outputs of many magnetic heads provided to a rotary cylinder to the coil provided to the side of a rotor in response to the tape traveling speed. CONSTITUTION:Magnetic heads 25a-25d are provided to a rotary cylinder 34 revolving at a constant speed by means of a driving motor 39. The heads 25a and 25c have 19.3mum track width and can reproduce for 6hr respectively; while the heads 25b and 25d have 58mum track width and can reproduce for 2hr respectively. A rotary core 36 is provided to the cylinder 34, and coils 28a and 28b are provided to the core 36. Lead switches 26 and 27 are switched by a magnetic field generating coil 30, and the coil 30 is controlled by a switch circuit 41. Coils 29a and 29b are buried to a stator core 37 to extract the outputs of the magnetic heads. In such a way, the outputs of many magnetic heads can be extracted individually with high quality with a small number of coils.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a magnetic recording and reproducing device, and aims to obtain high quality reproduced images.

Generally, in a magnetic recording/reproducing device having a magnetic head rotating device, the number of magnetic heads disposed on a rotating cylinder tends to increase due to the addition of various functions.

In this case, since the magnetic head itself is rotating, in order to take out the output signal to the outside, the number of poles of the rotating transformer must be increased in a one-to-one correspondence with the number of magnetic heads, or the number of poles of the rotating transformer must be increased in proportion to the number of magnetic heads. The current situation is to cope with the increase in the number of magnetic heads by adding slip rings with a corresponding number of poles.

In such devices, the dimensions and shape of the rotating transformer are becoming smaller and more dense due to increasing the number of poles of the rotating transformer or adding slip rings, resulting in increased crosstalk between poles and increased magnetic resistance of the rotating transformer itself. Performance deterioration due to etc.
Furthermore, since the shape of the rotary transformer becomes complicated, there are various problems such as a decrease in yield and a risk of increase in cost. Furthermore, if a slip ring corresponding to the magnetic head missing the rotating transformer is added, problems such as brush sliding noise and brush life will occur because the slip ring will come into direct contact with the rotating part.

A conventional magnetic recording/reproducing device will be explained below with reference to FIGS. 1 to 3.

FIG. 1 is an electrical connection diagram of a gutter rotation device for a magnetic recording/reproducing device having four conventionally used general magnets.

In the figure, magnetic heads 1a, 1b, 1C21d are coils 2a + 2b on the rotor core 8 side of the rotary transformer.
Magnetic heads 1a are connected to coils 3a, 3b, 3c, and 3d on the stator core 2° side of the rotary transformer of the fixed portion 6, which are connected to the coils 3a, 3b, 3c, and 3d, which constitute the rotating portion 4, and which are connected to the coils 3a, 3b, 3c, and 3d on the stator core 2° side of the rotating transformer of the fixed portion 6, respectively.

1b, 1c, and 1d to the magnetic field so as to transmit their outputs,
The rotating device is configured.

FIG. 2 is a block diagram showing a more detailed example of the rotating section of the device.

A rotor core 8 of a rotary transformer has four magnetic heads 1a, 1b, 1c, and 1d arranged and attached around a magnetic head mounting base (rotary cylinder) 7, and has four concentric coil grooves inside thereof. The coils 2a, 2b, 2c are installed in the coil grooves of the rotor core 8.
, 2d are fitted, and the respective coils 2a, 2b, 2
c, 2d and each magnetic head 1a.

1b, 1c, and 1d are connected by lead wires, printed wiring boards, or the like.

FIG. 3 is a sectional view of a magnetic head rotating device in which a magnetic head and a rotating transformer are actually installed.

Magnetic heads 1a, 1b, and 1c are mounted on a magnetic head mounting base 7.

1d is attached. A rotary shaft 13 is press-fitted into the center of the magnetic head mount 7 . On the other hand, the stator core 2o of the rotating transformer is attached to a fixed base 19.

The rotating part 4 and the fixed part 5 are fitted together by a rotating shaft 13 and ball bearings 22a and 22b. On the other hand, the rotating shaft 13 is connected to a drive motor 24 so as to be rotatable.

Further, the rotor core 8 and stator core 2o constituting the rotary transformer are arranged opposite to each other, and each core 8.2o has four concentric grooves, and each groove has a coil 2.
a, 2b, 2C12d, 3a, 3b.

3c and 3d are fitted. Coils 2a, 2b, 2c, 2d on the rotor core 8 side and magnetic heads 1a, 1b.

1c, 1d are lead wires 17a, 17b, 17c, 17d
connected by. Further, on the stator core 2o side, an output signal can be taken out from the fixed part 6 to an external device using the lead wire 23.

Rotor core 8 side and stator core 20 of trench rotary transformer
A predetermined gap is maintained between the sides by a spacer member 14.

In this way, a 4-pole rotating transformer is required for the 4 magnetic heads, but using a 4-pole rotating transformer for the 4 magnetic heads and the throat has a limit on the gap between the poles. This leads to performance deterioration such as an increase in crosstalk between poles and a decrease in Q value due to an increase in magnetic resistance, resulting in a disadvantage in that the quality of reproduced images deteriorates.

The present invention eliminates such drawbacks and provides a magnetic recording/reproducing device having a simple configuration and exhibiting little deterioration in performance even when the number of magnetic fields is increased.

An embodiment of the present invention will be described below with reference to FIGS. 4 to 7. FIG. 4 is an electrical wiring diagram of a magnetic head rotating device of a four-magnetic head type magnetic recording/reproducing device which is an embodiment of the present invention, FIG. 5 is a configuration diagram of the rotating part of the same device, and FIG. The sectional view and FIG. 7 are explanatory views of the operation of the device.

In the figure, 25B, 25b, 25c, and 25d are magnetic heads disposed on a rotating cylinder 34 that is rotated at a constant speed by a drive motor 39, and heads 26a and 25c are heads for 6-hour playback mode with a track width of 19.3 μm. The heads 25b and 25d are heads for a two-hour playback mode with a track width of 68 μm. 36 is a rotor core made of a magnetic material provided in the rotating cylinder 34, and the rotor core 36
are provided with two concentric grooves each having a coil 28a, 28b.

27.26 is a reed switch, and the movable contact pieces 26c, 2
7c to fixed contacts 26a, 27B or fixed contacts 26b, 2
7b. 30 is a reed switch 26
．． The coil 3o is a coil for generating a magnetic field which is used to switch the coil 3o. Reference numeral 41 denotes a tape running mode switching circuit for switching the tape running speed by switching between 2-hour playback, 6-hour playback, etc. The switching output of the switching circuit 41 is applied to the control signal generator 31. 37 is a stator core in which two coils 29B, 29b are embedded concentrically, and is fixed to the fixed base 5 so as to face the rotor core 36.

A support member 40 supports the coil 30 with a predetermined gap from the rotating cylinder 34, and is fixed to the fixed base 38.

Next, the operation of this device will be explained.

Without switching, the drive motor 39 is operated to rotate the rotary cylinder 34 at a constant speed, and the tape running mode switching circuit 41 is switched to the reproduction mode for 2 hours from time t1 to t2 to run the magnetic tape at a constant speed. and then from time t2 to t3
The magnetic tape is run at low speed by switching to the playback mode for 6 hours.

As a result, in response to the switching output from the switching circuit 41, a control signal as shown in FIG. 7A is applied from the control signal generator 31 to the coil 3o.

Based on this control signal, switches 26 and 27 are activated as shown in FIG.
, C, the magnetic head 26 is switched as shown in FIG.
Time t1 to t2 when the output of a is also in the 2-hour reproduction mode
The output of the magnetic head 25b is supplied between the two.

Similarly, the output of the magnetic head 25c is supplied to the coil 281) in the range of time t2 to t3, and the output of the magnetic head 25d is supplied in the range of time t1 to t2.

The outputs switched in this way and supplied to the coils 28a and 28b attached to the rotor core 36 are induced in the coils 29a and 29b attached to the stator core 37, and are supplied to a video signal processing circuit (not shown). .

In this way, in the present implementation, the heads 26a and 25d with a track width of 19.371 m are used in the 6-hour playback mode, and the heads 25b and 25d with a track width of 68 μm in the 2-hour playback mode are used.
As described above, according to the present invention, the output from a large number of magnetic heads disposed on a rotating cylinder is selectively transferred to the rotor side according to the tape running speed. By supplying the magnetic head to the coil, the outputs of a large number of magnetic heads can be extracted separately and with high quality using a small number of coils, making it possible to easily increase the number of heads and make it smaller and lighter. .

[Brief explanation of drawings]

Fig. 1 is an electrical wiring diagram of a magnetic head rotating device of a conventional magnetic recording/reproducing device, Fig. 2 is a configuration diagram of the rotating part of the same device, and Fig. 3
The figure is a sectional view of the same device, and FIG. 4 is an electrical wiring diagram of a magnetic head rotating device of a magnetic recording and reproducing device that is an embodiment of the present invention.
FIG. 5 is a configuration diagram of the rotating part of the device, FIG. 6 is a sectional view of the device, and FIG. 7 is an explanatory diagram of the operation of the device. 1 a, 11), I C, 1d 111+111
1@11 magnetic head, 2a, 2b. 2C+ 2d + 3a, 3b + 3c, 3d
l+11@@1111 coil, 4111+#...rotating part, 5...fixed part, 7...to magnetism. Mounting base (rotating cylinder), 8... Rotor core, 13... Rotating shaft, 19... Fixed base, 2o... Stator core, 24.・・・・・・
Drive motor, 25aI25b, 26c, 25das
-see magnetic head, 26°27 @@@111111
Reed switch, 26a, 26b, 27a+27b-,
... Fixed contact, 26c, 27c... Movable contact piece, 28a, 28b, 29a, 29b-m-coil, 30
---...- Koinope for switch drive 31mmmmmmmm
Switch drive control signal drive motor 2...Rotating part, 33@111+111111 Fixed part, 34 @11
1+111111 rotating cylinder, 36°...rotor core, 38...--fixed base, 37--...
...Stator core, 3911...e drive motor,
40...Supporting member, 41...Tape running mode switching circuit. Name of agent: Patent attorney Toshio Nakao (1st person)
Fig. 1g Fig. 3 Fig. 4FjJ 6b Fig. 6 Fig. 7 ■ 1:1 ■ Unexamined Patent Application Procedural Amendment Document Showa ru sy:r June M-11 q'1゛Indication of the Director-General of the License Agency 1 Case Showa 57 'l! J'7'l' Dr Gui
No. 616735y2 Name of the invention Magnetic recording and reproducing device 3 Amendment n Matter 1'1 and Noshi'1 (, -11' Applicant (1) 1006 Ou Kadoma, Kadoma City, Osaka Prefecture Place name Name (582) Matsushita Electric Co., Ltd. Industry Association and 1-Representative Akane
111 Toshihiko Shimo 4 Agent 571 Address 1006 Kadoma City, Osaka Matsushita Electric Industrial (1. Ceremony? I-+'q 5. Specifications subject to amendment 1. Name of invention Magnetic recording Reproduction device 2, claims (1) A plurality of magnetic nodules disposed in a rotating cylinder and in contact with a magnetic tape, a rotor of a rotating transformer that rotates integrally with the magnetic head, and an output of the magnetic head. a stator of a rotary transformer for taking out the magnetic tape; a switch circuit for selectively applying the outputs of the plurality of magnetic heads to the rotor of the rotary transformer; a running mode switching means for switching the running mode of the magnetic tape; a magnetic recording/reproducing device comprising: a switch control means for switching the switch circuit according to a running mode of the magnetic recording/reproducing device; A magnetic recording/reproducing device according to claim 1, characterized in that: 3. Detailed Description of the Invention The present invention relates to a magnetic recording/reproducing device, and an object thereof is to obtain a high-quality reproduced image.Generally , there is a tendency for the number of magnetic heads disposed on a rotating cylinder to increase due to the addition of various functions in magnetic recording and reproducing devices having a magnetic head rotating device.In this case, since the magnetic head itself is rotating, When taking out the output signal externally, it is necessary to use a one-to-one ratio for the number of magnetic heads.
The current situation is to cope with the increase in the number of magnetic heads by increasing the number of poles of the rotating transformer or by adding a slip ring with the number of poles corresponding to the shortage. In such devices, the dimensions and shape of the rotating transformer are becoming smaller and more dense due to increasing the number of poles of the rotating transformer or adding slip rings, resulting in increased crosstalk between poles and increased magnetic resistance of the rotating transformer itself. Performance deterioration due to etc.
Furthermore, since the shape of the rotary transformer becomes complicated, there are various problems such as a decrease in yield and a risk of increase in cost. Furthermore, if a slip ring corresponding to the magnetic head missing in the rotating transformer is added, problems such as plan sliding noise and plan life will occur because the slip ring will come into direct contact with the rotating part. A conventional magnetic recording/reproducing device will be explained below with reference to FIGS. 1 to 3. FIG. 1 is an electrical connection diagram of a magnetic head rotating device of a conventionally used general magnetic recording/reproducing apparatus having four magnetic heads. In the figure, magnetic heads 1a, 1b, and 1c. 1d is the coil 2a, 2 on the rotor core 8 side of the rotating transformer.
coils 3a, 3b, 3c on the stator core 20 side of the rotary transformer of the stationary part 6; The magnetic rotation device is configured to transmit the outputs of the magnetic heads 1a, 1b, IC, and 1d to the magnetic heads 1a, 1b, and 1d. FIG. 2 is a block diagram showing a more detailed example of the rotating section of the device. Four magnetic heads 1a, 1'b, IC, and 1d are arranged and mounted around a magnetic head mounting base (rotating cylinder) 7, and a concentric ring 8 is mounted inside the magnetic heads 1a, 1'b, IC, and 1d. Inside the coil groove are coils 2a and 2.
b, 2c, 2d are fitted, each carp/l/2
a, 2b, 2c, 2d and each magnetic head 1a
, 1b, 1c, and 1d are connected by lead wires, printed wiring boards, or the like. FIG. 3 is a sectional view of a magnetic head rotating device in which a magnetic head and a rotating transformer are actually installed. To the magnetic head mounting base 7 ・Sodo 1 a, 1 b
, 1c. 1d is attached. A rotary shaft 13 is press-fitted into the center of the magnetic gutter mount 7 and fixed thereto. On the other hand, the stator core 20 of the rotating transformer is attached to a fixed base 19. The rotating part 4 and the fixed part 6 are fitted together by a rotating shaft 13 and ball bearings 22a and 22b. On the other hand, the rotating shaft 13 is connected to a drive motor 24 so as to be rotatable. Further, the rotor core 8 and stator core 20 constituting the rotary transformer are arranged opposite to each other, and each core 8.2o has four concentric grooves, and each groove has a coil 2.
a, 2b, 2c, 2d, 3a. 3b, 3c, and 3d are fitted. rotor core 8
The coils 2a, 2b, 2c, 2d of 9'llI and the magnetic heads 1a, 1b, 1c, 1d are lead wires 17a. 17b, 17C, and 17d. Further, on the stator core 20 side, an output signal can be taken out from the fixed part 5 to an external device using a lead wire 23. Also, the rotor core 8 side of the rotating trunk and the stator core 20 side
A predetermined gap is maintained between the sides by a spacer member 14. In this way, a 4-pole rotating transformer is required for the 4 magnetic heads, but using a 4-pole rotating transformer for the 4 magnetic heads also limits the gap between the poles.
This results in performance deterioration such as an increase in crosstalk between poles and a decrease in Q value due to an increase in magnetic resistance, resulting in a disadvantage in that the quality of reproduced images deteriorates. The present invention eliminates these drawbacks, and provides a magnetic recording/reproducing device with a simple configuration that exhibits little performance deterioration even when the number of magnetic heads is increased. An embodiment of the present invention will be described below with reference to FIGS. 4 to 7. FIG. 4 is an electrical wiring diagram of a magnetic head rotating device of a four-magnetic head type magnetic recording/reproducing device which is an embodiment of the present invention, FIG. 6 is a configuration diagram of the rotating section of the same device, and FIG. The sectional view and FIG. 7 are explanatory views of the operation of the device. In the figure, 25a, 25b, 25c, and 25d are magnetic heads disposed on a rotating cylinder 34 rotated at a constant speed by a drive motor 39, and a head 26a. 25c is a 6-hour playback mode head with a track width of 19.3 μm, and heads 25b and 2sd are 2-hour playback mode heads with a track width of 58 μm. 36 is a rotor core made of a magnetic material provided in the rotating cylinder 34, and the rotor core 36 is provided with two concentric grooves each having a coil 28a, 261). 2, 26 is a reed switch, and depending on the presence or absence of a magnetic field applied from the outside or the reversal of polarity,
, 27c as fixed contacts 26a, 27a or fixed contact 2
Switch to either 6b or 27b. 30 is a coil for generating a magnetic field for switching the reed switches 26 and 27, and the coil 30 is the control signal generator 3.
It is driven by the control signal from 1. Reference numeral 41 denotes a tape running mode switching circuit for switching the tape running speed by switching between 2-hour playback, 6-hour playback, etc., and the switching output of the switching circuit 41 is output from the control signal generator 31.
is applied to 37 is two concentric coils 29a.
, 29b is embedded in the stator core, and the fixed base 38
is fixed to face the rotor core 36. A support member 40 supports the coil 30 from the rotating cylinder 34 with a predetermined gap, and is fixed to the fixed base 38. Next, the operation of this device will be explained. First, the drive motor 39 is operated to rotate the rotary cylinder 34 at a constant speed, and the tape running mode switching circuit 41 is switched to the 2-hour reproduction mode from time t1 to t2 to run the magnetic tape at a constant speed. Then, the magnetic tape is run at a low speed. As a result, in response to the switching output from the switching circuit 41, a control signal as shown in FIG. 7A is applied from the control signal generator 31 to the coil 30. Based on this control signal, the switch 26.27 is switched as shown in FIG.
Time t1 to t when the output of 5a is also in the 2-hour reproduction mode
2, the output of the magnetic head 25b is supplied. Similarly, the output of the magnetic head 25C is supplied to the coil 28b in the range of time t2-t3, and the output of the magnetic head 2sd is supplied in the range of time t to t2. The outputs switched in this way and supplied to the coils 28a and 28b attached to the rotor core 36 are output to the coil 29a attached to the stator core 37. 29b and is supplied to a video signal processing circuit (not shown). In this embodiment, the heads 2sa and 2sd with a track width of 19.3 μm are used in the 6-hour playback mode, and the heads 25b and 2sd with a track width of 68 μm are used in the 2-hour playback mode.
By using 5c, a high quality reproduced image with a good S/N ratio can be obtained. In this embodiment, the coil 30 was turned ON and OFF in the 2-hour mode and the 6-hour mode, but it is also possible to change the operating state as appropriate by changing the number of magnetic nodes to 2 gaps, etc. Further, although two sets of coils forming the rotary transformer are provided, the present invention is not limited to this, and the number of coils can be further reduced by increasing the number of contacts of the switch. Furthermore, by selecting the mounting position of the reed switch, each reed switch can be switched separately using multiple coils instead of one coil. You can also switch. In this case, not only a one-polar magnet but also a multi-polar magnet can be used as the permanent magnet. Further, in this embodiment, an example using an electromagnet and a reed switch is shown, but the same effect can be obtained using a photorelay that is a combination of a light emitting diode and a phototransistor. As described above, according to the present invention, by selectively supplying the output from a large number of magnetic heads disposed on a rotating cylinder to a coil on the rotor side depending on the tape running speed,
The outputs of a large number of magnetic heads can be extracted separately and with high quality with a small number of coils, and the number of heads can be easily increased, and the size and weight can be reduced. 4. Brief explanation of the drawings Fig. 1 is an electrical wiring diagram of a magnetic head rotating device of a conventional magnetic recording and reproducing device, Fig. 2 is a configuration diagram of the rotating part of the same device, and Fig. 3
The figure is a sectional view of the same device, and FIG. 4 is an electrical wiring diagram of a magnetic head rotating device of a magnetic recording and reproducing device that is an embodiment of the present invention.
FIG. 5 is a configuration diagram of the rotating part of the device, FIG. 6 is a sectional view of the device, and FIG. 7 is an explanatory diagram of the operation of the device. 1a, 1b, 1c, 1d---Magnetic head, 2a
. 2b, 2c, 2d, 3a, 3b, 3c, 3d--
- Coil, 4...Rotating part, 6...Fixed part, 7...Magnetic head mounting base (rotating cylinder), 8...-Rotor core, 13... ... Rotating shaft, 19 ... Fixed base, 20 ... Stator core, 24 ... Drive motor, 25 &. 25b, 25c, 26d---magnetic head,
26゜27...Reed switch, 26a, 2
6b, 27a. 27b...Fixed contact, 26c, 27a...-
・Movable contact pieces, 28a, 28b, 29a, 29b-
- Coil, 30... Switch drive coil, 31... Switch drive control signal generator, 3
2... Rotating part, 33... Fixed part, 34
... Rotating cylinder, 36 ... Rotor core, 38 ... Fixed base, 37 ... Stator core, 39 ... Drive motor, 40. ...
...Supporting member, 41...Tape running mode switching circuit.

Claims (2)

[Claims] (1) A plurality of magnetic heads disposed on a rotating cylinder and in contact with a magnetic tape, a rotor of a rotating transformer that rotates integrally with the magnetic heads, and a stator of the rotating transformer that extracts the output of the magnetic heads. , a switch circuit for selectively applying the outputs of the plurality of magnetic heads to the rotor of the rotary transformer, a running mode switching means for switching the running mode of the magnetic tape, and the switch circuit according to the running mode of the magnetic tape. A magnetic recording/reproducing device comprising a switch control means for switching. times (2) The magnetic recording and reproducing apparatus according to claim 1, wherein the switch circuit is provided in the semi-rotating cylinder, and the switch control means is arranged at a distance from the rotating cylinder.