JPH0376002A - Magnetic recording and reproducing device - Google Patents

Abstract

PURPOSE:To greatly prevent the disturbance from entering a small reproduction signal by providing a signal selecting part and an amplifying part which amplifies the reproduction signal switched from the signal selecting part and applying this signal to other rotary transformer on a rotary cylinder. CONSTITUTION:An electric power source obtd. in an electric power source current rectifying part 1 is supplied to the amplifying part 2, a control signal detecting part 3 and the signal selecting part 4. The composite signals are supplied to the rotary cylinder via the rotary transformer from a signal generating circuit in this case. The electric power source is obtd. in the rotary cylinder in accordance with this signal. The control signal is simultaneously detected and the signals obtd. from plural rotary heads are switched and are amplified in the rotary cylinder, by which the reproduction signal can be transmitted to the stationary part side. The reproduction signal is hardly influenced by the disturbance in this way and is hardly restricted in mechanism by the rotary transformer or brush.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a magnetic recording/reproducing device equipped with a rotating head cylinder.

BACKGROUND OF THE INVENTION Conventionally, in magnetic recording and reproducing devices that magnetically record and reproduce signals on a rotating head cylinder, signals reproduced from a magnetic tape are directly transmitted using a rotary transformer or a brush.
After transmitting the signal to a fixed cylinder, amplifying and adjusting the signal, the necessary video and audio signals were obtained. Furthermore, the same number of magnetic heads and rotary transformers are required, and even when a brush is used in place of the rotary transformer to transmit signals to the fixed cylinder, the types of signals and the enclosed brushes are required.

Problems to be Solved by the Invention However, in the conventional configuration, the minute reproduction signal reproduced by the magnetic head is input directly to the rotary transformer or brush, transmitted to the fixed cylinder side, and input to the first stage amplifier where it is amplified. be done.

There is a problem in that the reproduced signal is most susceptible to disturbances during the process of being input to the first-stage amplifier, and the characteristics of the reproduced signal are likely to deteriorate.

Furthermore, when signals are transmitted to a fixed cylinder using a brush, in addition to the above-mentioned problems, there is a problem of deterioration of characteristics due to changes in contact resistance of the brush. Additionally, there is a problem in that there are mechanical limitations due to the number of magnetic heads in the rotary head cylinder and the need for an enclosed rotary transformer housing or brush.

The present invention solves these conventional problems and provides a magnetic recording/reproducing device in which a reproduced signal is less susceptible to external disturbances and is less subject to mechanical restrictions due to a rotary transformer or a brush.

Means for Solving the Problems The magnetic recording and reproducing device of the present invention includes a rotating cylinder provided with a plurality of rotating heads, and a plurality of rotary transformers for transmitting data between the rotating cylinder and a fixed part. A magnetic recording and reproducing device that records and reproduces signals on a tape, the device includes a signal generation circuit that generates a composite signal in which a control signal is superimposed on an AC power source and supplies it to a predetermined rotary transformer, and the rotating cylinder a power rectifier that obtains power from a composite signal provided by the rotary transformer;
a control signal detection unit that detects a control signal from a composite signal provided by the predetermined rotary transformer; and a signal selection unit that switches signals obtained from the plurality of rotary heads based on the control signal obtained from the control signal detection unit. ,
The present invention is characterized in that it includes an amplifying section that amplifies the reproduced signal switched by the signal selecting section and supplies the amplified signal to another rotary transformer.

According to the present invention having such features, a composite signal is applied from the signal generation circuit to the rotating cylinder via the rotary transformer, and the rotating cylinder receives power and control signals based on the signal. The detected signals obtained from a plurality of rotating heads can be switched, amplified within the rotating cylinder, and a reproduction signal can be transmitted to the fixed part.

Embodiment A magnetic recording/reproducing apparatus according to an embodiment of the present invention will be described below with reference to a circuit block diagram. As shown in FIG.
and is supplied to the signal selection section 4. FIG. 2 shows a circuit diagram of the power supply rectifier 1 and the control signal detector 2. In FIG. Further, the power supply rotary transformer 6 and the reproduction signal transmission rotary transformer 6 are used to electrically transmit power and signals to and from the fixed cylinder. The power supply AC signal has a frequency of, for example, 10 KHz, and the control signal has a frequency of, for example, 40 KHz and only 30 intermittent cycles. 7.8 is a magnetic head whose signal is given to the signal selection section 4. In this figure, the area indicated by the dashed line indicates the rotating cylinder 9, which is rotated at a predetermined speed by a drive source (not shown). Now, a signal generating circuit 1o is provided in a fixed part of the magnetic recording/reproducing apparatus. The signal generating circuit 10 generates a composite signal in which a power supply AC signal and a control signal are superimposed.

The composite signal of FIG. 3a generated by the signal generation circuit 10 is
The power enters the power rectifier 1 from the power rotary transformer 5. The composite signal is then converted into DC by the power rectifier 12, 13 and the smoothing capacitor 14, and voltage adjusted by the power output transistor 15, voltage regulator diode 16, and smoothing capacitor 17 to obtain a DC power source. This power source is supplied to the amplifier section 2, signal selection section 4, and control signal detection section 3 as a driving power source.

Furthermore, since the composite signal shown in FIG. 3A also includes a control signal component, the control signal waveform shown in FIG. The control signal is detected by the control signal detection diodes 28 and 29 and the smoothing capacitor 31 as shown in FIG. 3C. This signal is input to the signal selection section 4, which selects the reproduction signal to be reproduced by the magnetic head 7.8 as shown in FIGS. 3d and 3e. The selected reproduced signal is amplified by the amplifying section 2 to obtain a reproduced continuous signal waveform shown in the right part of FIG.

This signal is transferred to the rotary transformer 6 for transmitting the reproduced signal to the next stage.
is input and transmitted to the fixed cylinder side.

The transmitted playback signal undergoes conventional signal processing at a subsequent stage.
Obtain the desired video, audio, etc. signals.

According to this embodiment, by amplifying the reproduced signal within the rotary head cylinder, it becomes easy to prevent disturbances entering the reproduced signal. In particular, the signal-to-noise ratio is characterized by a tendency for the holding property to worsen as the minute signal line becomes longer, but the present invention can significantly shorten the minute signal line. Since reproduction signals are selected within a rotary cylinder, there is no need to increase the number of heads or add an enclosed rotary transformer, so there are no mechanical constraints when increasing the number of heads.

Effects of the Invention As described above, in the present invention, by providing the amplification section inside the rotary head cylinder, it is possible to significantly prevent disturbances that enter a minute reproduction signal. Furthermore, the signal selection function prevents the addition of a rotary transformer even when increasing the number of heads.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing a magnetic recording/reproducing device according to an embodiment of the present invention, FIG. 2 is a circuit diagram showing an embodiment of a power supply rectifying section 1 and a control signal detecting section 2, and FIG. 3 is a circuit diagram showing an embodiment of the above embodiment. FIG. 2 is a waveform diagram showing signal waveforms of main parts of the . 1...Power rectification section, 2...Amplification section, 3
... Control signal detection section, 4 ... Signal selection section, 5 ... Rotary transformer for power supply, 6 ...
...Rotary transformer for transmitting reproduced signals, 7...
...Magnetic head, 8...Magnetic head, 9...
...Cylinder, 10...Signal generation circuit, 1
2.13... Power supply rectifier, 14... Smoothing capacitor, 16... Power output transistor, 16... Constant voltage diode, 1.・
...Smoothing capacitor, 18...DC power supply output, 19,20...Control signal passing capacitor, 2
1... Adjustment resistor, 22.23... Bias resistor, 25... Control signal amplification transistor, 24... Load resistor, 28.29... ...
Control signal detection diode, 31... Control signal smoothing capacitor.

Claims (1)

[Claims] A magnetic recording and reproducing device that records and reproduces signals on a magnetic tape, comprising a rotating cylinder provided with a plurality of rotating heads and a plurality of rotary transformers that perform transmission between the rotating cylinder and a fixed part, It has a signal generation circuit that generates a composite signal in which a control signal is superimposed on an AC power source and supplies it to a predetermined rotary transformer, and the rotary cylinder has a power rectifier that receives power from the composite signal supplied from the predetermined rotary transformer. , a control signal detection unit that detects a control signal from a composite signal provided by the predetermined rotary transformer, and a signal selection unit that switches signals obtained from the plurality of rotary heads based on the control signal obtained from the control signal detection unit. and an amplification section that amplifies the reproduction signal switched by the signal selection section and supplies it to another rotary transformer.