JPH0765304A - Magnetic recording and reproducing device - Google Patents

Abstract

PURPOSE:To prevent the number of rotary transformers from being increased in a magnetic recording and reproducing device using a recording head whose gap length is long and a reproducing head whose gap length is short for a rotary cylinder. CONSTITUTION:This device is provided with a switch 4 for selectively switching the recording head 1 and the reproducing head 2 and connecting it to the rotary transformer 5 on the rotary cylinder. It is also provided with a non-contact power supply source and a non-contact control signal transmitting means for driving the switch 4.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic recording / reproducing apparatus for recording / reproducing information signals such as video signals and audio signals using a rotary head.

[0002]

2. Description of the Related Art In recent years, in a recording / reproducing apparatus such as a video tape recorder using a rotary head, there is an increasing need for high density recording in response to a demand for high image quality and high sound quality. Along with this, a recording / reproducing head with a short gap length is required.

A conventional magnetic recording / reproducing apparatus will be described below with reference to the drawings. Many conventional video tape recorders have both a recording head and a reproducing head. FIG. 6 is a block diagram of a conventional magnetic recording / reproducing apparatus that doubles as a recording head and a reproducing head.

In FIG. 6, the recording / reproducing head 61 is connected via a rotary transformer 62 by selectively switching the input of a reproducing amplifier 64 and the output of a recording amplifier 65 with a switch 63. The output of the reproduction amplifier 64 is connected to the reproduction output terminal 67, the input of the recording amplifier 65 is connected to the recording input terminal 68, and 66 is a control signal input terminal for inputting a control signal for controlling the switch 63.

The operation of the recording / reproducing apparatus shown in FIG. 6 will be described. At the time of recording, the switch 63 is on the recording amplifier 65 side, and the recording current is supplied to the recording / reproducing head 61 via the rotary transformer 62 to perform the recording operation. During reproduction, the switch 63 is on the reproduction amplifier 64 side, and the recording / reproduction head 6
The reproduction signal reproduced from No. 1 is supplied to the reproduction amplifier 64 via the rotary transformer 62 and the reproduction operation is performed.

By the way, the gap length of the reproducing head has to be at least ½ or less of the shortest recording wavelength in order to reproduce a high-density recording signal, so that the gap length is very short. On the other hand, regarding the gap length of the recording head, it is possible to record even if the gap length is ½ or more of the shortest recording wavelength. Rather, if the gap length is shortened, the recording efficiency becomes poor and it becomes impossible to perform recording with sufficient strength. A problem arises. Therefore, in order to perform high-density recording / reproduction under optimum conditions, it is necessary that the reproducing head has a short gap length and that the recording head has a longer gap length than the reproducing head.

FIG. 7 shows a block diagram of a conventional magnetic recording / reproducing apparatus in which a recording head and a reproducing head are independently used in order to satisfy the above conditions.

In FIG. 7, the reproducing head 71 is connected to the input of the reproducing amplifier 75 via the rotary transformer 73, and the recording head 72 is connected to the output of the recording amplifier 76 via the rotary transformer 74. Reference numeral 77 is a reproduction output terminal, and 78 is a recording input terminal. The gap length of the recording head is set longer than the gap length of the reproducing head.

[0009]

However, in the conventional magnetic recording / reproducing apparatus shown in FIG. 7, a recording rotary transformer and a reproducing rotary transformer are separately required. However, the portion where the rotary transformer is installed is very narrow, and especially in the system in which the luminance signal and the color difference signal are recorded / reproduced by separate heads, the number of heads increases significantly, so the rotary There was a problem that it would be difficult to install a transformer.

The present invention solves the above problems, and an object of the present invention is to enable the recording head and the reproducing head to be set to the optimum gap length without separately providing a rotary transformer for recording and reproducing. And

[0011]

In order to achieve the above object, the present invention provides (1) a recording head, a reproducing head, a rotary transformer, and the rotary transformer selectively for the recording head or the reproducing head. The rotating cylinder is provided with a switching means to be connected. (Corresponding to claim 1) (2) A recording head, a reproducing head, a rotary transformer, a switching means for selectively connecting the rotary transformer to the recording head or the reproducing head, and a rotary transformer. A rotating cylinder is provided with a rectifying circuit, and the switching means is switched by the output of the rectifying circuit. (Corresponding to claim 12)

[0012]

In the magnetic recording / reproducing apparatus having the above-mentioned structure, the rotary transformer is switched between the recording head and the reproducing head by the switching means so that separate heads can be used for recording and reproducing without increasing the number of channels of the rotary transformer. It will be.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram of a magnetic recording / reproducing apparatus according to the first embodiment of the present invention. In FIG. 1, the recording head 1 is connected to the terminal 4b of the switch 4, the reproducing head 2 is connected to the terminal 4a of the switch 4 via the reproducing amplifier 3, and the common terminal 4c of the switch 4 is the winding 5a of the rotary transformer 5. , The winding 5b of the rotary transformer 5 is connected to the common terminal 6c of the switch 6, the terminal 6b of the switch 6 is connected to the recording input terminal 14, and the terminal 6a is connected to the reproduction output terminal 15.

The control signal input terminal 13 is connected to the control input of the switch 6 and the LED 11, the phototransistor 9 receives light from the LED 11 and supplies its output to the control circuit 8, and the output of the control circuit 8 is the output of the switch 4. Supplied to control terminal.

The regenerative amplifier 3, the switch 4 and the control circuit 8 on the rotary cylinder are supplied with power from the solar cell 7, and the solar cell 7 is supplied with light energy from the lamp 10.

In the above structure, the recording head 1, the reproducing head 2, the reproducing amplifier 3, the switch 4, the winding 5a of the rotary transformer 5, the solar cell 7, the control circuit 8 and the phototransistor 9 are mounted on a rotating cylinder. ing. The gap length of the recording head 1 is longer than that of the reproducing head 2.

The operation of this embodiment configured as described above will be described. First, at the time of recording, the control signal applied to the control signal input terminal 13 causes the LED 11 to emit light, which is received by the phototransistor 9 and supplied to the control circuit 8. The control circuit 8 receives the information and sets the switch 4 to the 4b side.
At the same time, the control signal sets the switch 6 to the 6b side. Then, the recording signal is guided from the recording input terminal 14 to the recording head 1 through the switch 6, the rotary transformer 5 and the switch 4, and the recording operation is performed.

Next, during reproduction, the control signal does not cause the LED 11 to emit light, so that the control circuit 8 receives the information and sets the switch 4 to the 4a side. At the same time, the control signal sets the switch 6 to the 6a side. The reproduction signal reproduced from the reproduction head 2 is amplified by the reproduction amplifier 3, and the switch 4,
It is led to the reproduction output terminal 15 through the rotary transformer 5 and the switch 6.

The control circuit 8, the switch 4, and the regenerative amplifier 3 on the rotary cylinder are powered by the solar cell 7, and the light energy to the solar cell 7 is supplied by the lamp 10.

With the above construction, in this embodiment, it is not necessary to provide the rotary transformers for recording and reproducing, respectively, so that the rotary transformer can be provided even in a narrow space. Then, both the recording head and the reproducing head can have optimum head characteristics. Nowadays,
There is a video tape recorder that records and reproduces a luminance signal and a color difference signal with separate heads. In that case, if the recording head and the reproducing head are separated, two heads face each other 180 ° on the rotary cylinder. However, it is very difficult to provide a rotary transformer having such a number of channels, but even in such a case, by using this embodiment, The number of channels of the rotary transformer is 4
Since it requires only a channel, it can be installed in a narrow space.

The reproduction amplifier 3 is for preventing the S / N from being deteriorated by passing a minute reproduction signal reproduced by the reproduction head 2 through the switch 4, the rotary transformer 5 and the switch 6. is there.

FIG. 2 is a conceptual diagram of the rotary cylinder section showing the arrangement of the phototransistor provided on the rotary cylinder and the LED provided on the main body side. As you can see from the figure,
Since the phototransistor 9 can receive the light from the LED 11 only once per one rotation of the rotary cylinder 21, it is necessary to hold the information until the next light reception. Therefore, the control circuit 8 of FIG. 1 also includes this hold function. In addition, the vicinity of the rotating cylinder of the magnetic recording / reproducing device has a very complicated mechanism.
The position where 1 or the phototransistor 9 can be installed is limited. Therefore, the timing when the phototransistor 9 receives the light from the LED 11 does not always coincide with the switching timing required for recording / reproducing of the head.
Therefore, in order to correct this difference in timing, a delay circuit that delays the light receiving signal by a certain time is needed. In that case, the control circuit 8 of FIG. 1 may include the above delay circuit.

However, the phototransistor 9 and LE
When D11 is provided near the center of rotation of the cylinder 21, the above hold circuit and delay circuit are not necessary.

By the way, the control signal transmitting means composed of the LED 11, the phototransistor 9 and the control circuit 8 of FIG. 1 may be used also as the power supply means composed of the lamp 10 and the solar cell 7. FIG. 3 shows a block diagram of a magnetic recording / reproducing apparatus according to the second embodiment of the present invention.

In FIG. 3, the same reference numerals as those in FIG. 1 represent the same components. In this embodiment, the switch 4 is a switch 4 which is turned to the 4b side when the control terminal is energized and returned to the 4a side when the control terminal is turned off. At the time of recording, the lamp 10 is turned on by the control signal from the control signal input terminal 13, and the light energy causes a voltage to be generated in the solar cell 7, which drives the switch 4 to drive the recording head 1.
Switch to the side. During reproduction, the lamp 10 goes out and the switch 4 returns to the reproduction head 2 side. Therefore, in the case of the present embodiment, an LED and a phototransistor for control are not particularly required, and the configuration is simplified.

Next, a block diagram of a magnetic recording / reproducing apparatus in a third embodiment of the present invention in which one channel of a rotary transformer is used instead of the solar cell 7 and the lamp 10 of the embodiment of FIG. 4 shows.

In FIG. 4, the same reference numerals as those in FIG. 1 represent the same components, and 41 is the rotary transformer 4
A rectifier circuit that rectifies the high frequency current of the second winding 42a and drives the switch 4, and 43 is a oscillating circuit that generates a high frequency current according to a control signal from the control signal input terminal 13 and supplies it to the winding 42b of the rotary transformer 42. It is a vessel. In this case, the number of channels of the rotary transformer increases by one, but if there are many heads, they can be switched in common, so that the number of channels of the rotary transformer does not increase so much.

In the above embodiments, the control signal is transmitted and the power is supplied by the non-contact method, but a slip ring may be used instead. However, since the slip ring protrudes considerably above the rotary cylinder, it becomes space-consuming especially in the case of a portable type magnetic recording / reproducing apparatus. Further, uneven rotation of the rotary cylinder due to friction of the slip ring may be considered. On the other hand, the non-contact method of the present embodiment is advantageous in terms of space and uneven rotation.

A fourth embodiment of the present invention will be described below with reference to the drawings. FIG. 5 is a block diagram of a magnetic recording / reproducing apparatus according to the fourth embodiment of the present invention. 5, the same reference numerals as those in FIG. 1 represent the same components, and 51 indicates the winding 5a of the rotary transformer 5 during recording.
Rectifies the recording current appearing in the switch 4 with its rectified output.
It is a rectifier circuit for switching.

Since the present embodiment does not require an extra rotary transformer channel to supply power,
The configuration is further simplified as compared with the embodiment of FIG.

The LED 1 used in the embodiment of FIG.
1 and the phototransistor 9 for transmitting a control signal and one of the lamp 10 and the solar cell 7 for supplying power, the oscillator 43, the rotary transformer 42 and the rectifier circuit 41 shown in FIG. It may be replaced with any other means.

The LED 11 may be another light emitting element, and the phototransistor 9 may be another light receiving element. Further, the lamp 10 may be another light emitting element.

In addition, the LED 11 and the phototransistor 9
The combination of and may be a combination of a magnetic coil and a magnetic sensing element such as a Hall element.

[0035]

As is apparent from the above description, according to the magnetic recording / reproducing apparatus of the present invention, when different heads are used for recording and reproducing, the recording head and the reproducing head are selectively switched by the switching means. By connecting the rotary transformer to the rotary transformer, the increase in the number of channels of the rotary transformer can be suppressed. Further, by setting the gap length of the recording head longer than the gap length of the reproducing head, it is possible to obtain an excellent effect of enabling efficient recording / reproducing.

[Brief description of drawings]

FIG. 1 is a block diagram of a magnetic recording / reproducing apparatus according to a first embodiment of the present invention.

FIG. 2 is a conceptual diagram of a rotary cylinder portion of the magnetic recording / reproducing apparatus of FIG.

FIG. 3 is a block diagram of a magnetic recording / reproducing apparatus according to a second embodiment of the present invention.

FIG. 4 is a block diagram of a magnetic recording / reproducing apparatus according to a third embodiment of the present invention.

FIG. 5 is a block diagram of a magnetic recording / reproducing apparatus according to a fourth embodiment of the present invention.

FIG. 6 is a block diagram of a conventional magnetic recording / reproducing device.

FIG. 7 is a block diagram of a conventional magnetic recording / reproducing device.

[Explanation of symbols]

 1 recording head 2 reproducing head 3 reproducing amplifier 4 switch 5 rotary transformer 6 switch 7 solar cell 8 control circuit 9 phototransistor 10 lamp 11 LED 13 control signal input terminal 14 recording input terminal 15 reproducing output terminal 21 rotating cylinder 41 rectifying circuit 42 rotary Transformer 43 Oscillator 51 Rectifier circuit

Claims (14)

[Claims] 1. A magnetic recording system comprising: a rotary cylinder having a recording head, a reproducing head, a rotary transformer, and switching means for selectively connecting the rotary transformer to the recording head or the reproducing head. Playback device. 2. The magnetic recording / reproducing apparatus according to claim 1, wherein the gap length of the recording head is longer than the gap length of the reproducing head. 3. The magnetic recording according to claim 1, further comprising control signal transmission means for transmitting a control signal for controlling the switching means to the rotary cylinder in a non-contact manner. Playback device. 4. A magnetic recording / reproducing apparatus according to claim 3, wherein the rotating cylinder is provided with a delay means for delaying the control signal, and the switching means is controlled by an output of the delay means. 5. The magnetic device according to claim 3, wherein the control signal transmitting means includes a light receiving portion provided on the rotary cylinder and a light emitting portion provided on the fixed portion. Recording / playback device. 6. The control signal transmission means includes a magnetic detection part provided on the rotary cylinder and a magnetic coil part provided on the fixed part, as claimed in any one of claims 3 to 4. Magnetic recording and reproducing device. 7. The magnetic recording / reproducing apparatus according to claim 3, wherein the control signal transmitting means includes a specific channel of a rotary transformer. 8. The magnetic recording / reproducing apparatus according to claim 1, further comprising a power supply means for supplying a power supply for driving the switching means to the rotary cylinder in a non-contact manner. . 9. The switching means is controlled by the presence / absence of power supplied by the power supply means.
The magnetic recording / reproducing apparatus according to. 10. The magnetic recording / reproducing apparatus according to claim 8, wherein a reproducing amplifier is provided between the reproducing head and the switching means, and power is supplied from the power supply means to the reproducing amplifier. 11. The magnetic recording according to claim 8, wherein the power supply means includes a solar cell provided on the rotary cylinder and a light emitting section provided on the fixed portion. Playback device. 12. The power supply means includes a specific channel of a rotary transformer and a rectifying circuit provided on the rotary cylinder side of its winding, as claimed in any one of claims 8 to 10. Magnetic recording and reproducing device. 13. A recording head, a reproducing head, a rotary transformer, a switching means for selectively connecting the rotary transformer to the recording head or the reproducing head, and a rectifying circuit connected to the rotary transformer. A magnetic recording / reproducing apparatus comprising a cylinder, wherein the switching means is switched by the output of the rectifying circuit. 14. The magnetic recording / reproducing apparatus according to claim 13, wherein the gap length of the recording head is longer than the gap length of the reproducing head.