JPS6313101A - Rotating head type signal recording and reproducing device - Google Patents

Abstract

PURPOSE:To prevent the deterioration of a frequency characteristic over a wide band by transmitting a signal from a circuit with a low output impedance to a primary side, and from a secondary side to a circuit with a low input impedance in a rotating transformer connecting a rotating cylinder and a main body device. CONSTITUTION:From a circuit with a low impedance through a transistor 9 to form a emitter follower, a recording signal which is not deteriorated at a low area by the impedance component of a transformer, the impedance of a winding and a low output impedance is transmitted to the primary side of a rotating transformer. The signal is transmitted from a secondary side 12 of the transformer through a transistor 16 to form the low output impedance circuit of a base ground to a recoding amplifier 17, and the high area deterioration of a transmitting signal is prevented by the stray capacity of a rotating transformer, leaking inductance, the low input of the primary and secondary sides and the output impedance. Concerning the reproducing signal through a pre-amplifer, the deterioration of the frequency characteristic is also prevented over a wise band.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a rotary head type signal recording and reproducing apparatus for recording and reproducing broadband signals, such as digitized video signals.

BACKGROUND OF THE INVENTION In a conventional rotary head type signal recording/reproducing device, a rotary transformer is generally used to input and output signals between the main body and a rotary cylinder on which the head is mounted.

Conventionally, signals are input and output between the main body and the rotating cylinder via this rotary transformer. For example, in a home VTR, the magnetic head mounted on the rotating cylinder is simply connected to the transformer mounted on the rotating cylinder side. Directly connected, the recording signal is transmitted from the transformer on the opposing main body side to the rotating cylinder. Also, the reproduction signal is transmitted from the rotating cylinder to the main body.

FIG. 3 shows an example of a conventional circuit configuration for transmitting a broadband signal through a rotary transformer of a household VTR. 1
is a recording amplifier, 2.7 is a main body side transformer, 3 and 6 are rotor 111 transformers, 4.5 is a magnetic herad, and 8 is a reproducing amplifier. The conventional operation will be explained below.

In the recording system, a wideband signal after signal processing is applied to the video signal is input to one recording amplifier.

The recording amplifier No. 1 outputs a signal such that the value of the current flowing to the magnetic head No. 4 becomes optimum, and the Heud reproduction output during reproduction becomes the maximum. This output is transmitted to the magnetic head 4 via the main body side transformer 2 and the rotary cylinder side transformer 3, and is recorded on the recording medium.

In the reproducing system, a magnetic head 6 obtains a reproducing signal from a recording medium and transmits it to a reproducing amplifier 8 via a rotary cylinder side transformer 6 and a main body side transformer 7.

The reproduced signal is amplified by the regenerative amplifier No. 8 to a thickness that allows signal processing, and is output.

Problems to be Solved by the Invention However, with the configuration shown in FIG.
For example, when transmitting a digitized video signal through a one-rotation transformer, the following problems have occurred.

(1) The inductance component of the rotary transformer,
The frequency characteristics of the transmitted signal deteriorate in low frequencies due to the impedance of the winding wound around the rotary transformer and the output impedance of the circuit that transmits the signal to the rotary transformer.

(2) The frequency characteristics of the transmitted signal deteriorate in high frequencies due to the stray capacitance and leakage inductance of the rotary transformer, and the input/output impedance on the primary and secondary sides of the rotary transformer.

In view of the above, the present invention is capable of transmitting a wideband signal through a rotary transformer while minimizing signal deterioration, and recording and reproducing the wideband signal in a rotary helad type signal recording and reproducing device. The purpose is to provide something.

Means for Solving the Problems The present invention is a rotary head type signal recording/reproducing device, in which a recording amplifier, a pre-reproducing amplifier, and a head are mounted on a rotating cylinder, and a rotary transformation is performed using a circuit with extremely low output impedance. from the primary side of the rotary transformer to the primary side of the rotary transformer.
It is characterized in that the signal transmitted to the next side is transmitted to the circuit-2 with very low input impedance.

According to the present invention, a signal is transmitted to the primary side transformer of a rotary transformer of a rotary head type signal recording/reproducing device through a circuit with extremely low output impedance. Next, the signal transmitted from the primary transformer to the secondary transformer is transmitted to a circuit with very low input impedance.

As a result, in the low frequency range, signal deterioration due to the inductance component of the rotary transformer, the impedance of the winding of the rotary transformer, and the output impedance of the circuit transmitting to the rotary transformer can be significantly suppressed. In addition, signal deterioration in the high range caused by the stray capacitance and leakage inductance of the rotary transformer, as well as the output impedance on the primary and secondary sides of the rotary transformer, can be greatly suppressed. . In addition, by installing a recording amplifier and a pre-reproduction amplifier on the rotating cylinder, the recording system can record a wideband signal transmitted from the main body side to the rotating cylinder side onto the recording medium with little signal deterioration. can. The reproduction system can amplify the wideband reproduction signal reproduced from the head and transmit it from the rotating cylinder side to the main body side with significantly suppressed signal deterioration.

Embodiment FIG. 1 shows a rotary head type signal recording and reproducing apparatus for magnetic recording and reproducing according to an embodiment of the present invention, in which a broadband recording signal is transmitted to a rotary cylinder via a rotary transformer, and a broadband recording signal is transmitted from the rotary cylinder to the rotary cylinder. , which shows a circuit system diagram for transmitting a broadband reproduction signal to the main body.

9.14, 16, 21.26.28 in Figure 1 are transistors, 10, 13, 22.25 are variable resistors, 11
．． 24 is a rotary transformer on the main body side, 12°23 is a rotary cylinder side transformer, 15.27 is a fixed resistor, 17 is a recording amplifier, 20 is a pre-reproducing amplifier, 18.19 is a magnetic head,
29 is a regenerative amplifier.

The operation in this embodiment shown in FIG. 1 will be described below.

In the recording system, a transistor 9 is used to configure an emitter follower circuit. Connect the emitter of the transistor 9 and one end of the main body transformer 11 via a capacitor,
Ground the other end.

A signal is inputted from the base of the transistor 9, and the signal is outputted from the emitter. The output impedance at this time is about several tens of ohms, which is low impedance. This output signal is transmitted to the main body side transformer 11 and the rotating cylinder side transformer 1.
2.

A common base circuit is configured using the transistor 14,
It is connected to one end of the rotating cylinder side transformer 12 via a capacitor. Note that the other end of the rotating cylinder side transformer 12 is grounded. Using the transistor 14, an emitter follower circuit is configured as a buffer 7 amplifier. The signal transmitted to the rotating cylinder side transformer 12 is transmitted via a capacitor.
The signal is input from the emitter of a common base circuit constituted by a transistor 14. The input impedance at this time is several tens of ohms
low impedance. Next, the signal is outputted from the collector with an appropriate voltage gain through a fixed resistor 15 connected between the collector of the transistor 14 and a constant voltage source.
The signal is transmitted to the recording amplifier 17 via the lid follower circuit. From the recording amplifier 17, a signal is transmitted to the magnetic head 18 such that the current value flowing through the magnetic head 18 is optimal and the output voltage value during reproduction is maximized. The transmitted signal is recorded on a recording medium by the magnetic head 18. The variable resistors 10 and 13 are used to adjust the input and output impedance of the rotary transformer and adjust the frequency characteristics of the recording system.

In the reproduction system, a magnetic helad 19 reproduces a signal from the recording medium, and a pre-reproduction amplifier 20 amplifies the reproduction signal. This amplified signal is constructed using a transistor 21, similar to the recording system, and has an output impedance of approximately several tens of ohms, and is transmitted to the rotating cylinder side transformer 23 via a low impedance emitter follower circuit and a capacitor. .

The transmitted signal is transmitted via the rotary cylinder side transformer 23 and the main body side transformer 24 to the emitter of a common base circuit configured using a transistor 26. The input impedance at this time is a low impedance of about several tens of ohms. Next, the signal is output with an appropriate voltage gain obtained by a fixed resistor 27 connected between the collector of the transistor 26 and a constant voltage source, and is outputted from an emitter which is a buffer amplifier configured using a transistor 28. The signal is transmitted to the regenerative amplifier 29 via the follower circuit.

A regenerative amplifier 29 amplifies the signal to a signal sufficient for subsequent signal processing, and outputs the signal. In addition, variable resistor 22.26
is for adjusting the frequency characteristics of the reproducing system as well as the recording system.

As described above, according to this embodiment, a recording amplifier and a pre-reproducing amplifier are mounted on the rotary cylinder of a rotary field type signal recording and reproducing device, and when transmitting a signal via a rotary transformer, rotating cylinder side.

The input/output impedance to the transformer on the main body side is low (, -
By providing a simple circuit to make the impedance
The following effects can be obtained.

(1) The inductance component of the rotary transformer,
Deterioration in the low frequency range of the transmitted signal due to the impedance of the winding of the rotary transformer and the output impedance of the circuit transmitting to the rotary transformer can be significantly suppressed.

(2) Significantly suppress deterioration in the high frequency range of transmitted signals by the stray capacitance and leakage inductance of the rotary transformer, and the input and output impedances on the primary and secondary sides of the rotary transformer. Can be done.

(3) In the recording system, the broadband signal with little signal degradation transmitted from the main body side to the rotating cylinder side can be recorded on the recording medium, and in the playback system, the broadband signal reproduced from the head is amplified and transferred to the rotating cylinder side. It is possible to transmit signals from the source to the main unit with significantly reduced signal deterioration.

In this embodiment, the emitter follower circuit is constructed using the transistor 9 in the recording system and the transistor 21 in the reproduction system, but other circuits having a wide band and a very low output impedance may be used. .

In this embodiment, a transistor 14 and a transistor 26 are used in the recording system and transistor 26 in the reproduction system to form a common base circuit. It may be a ground circuit.

In FIG. 2, 31 and 32 are transistors, and 30 is a fixed resistor. The common base circuit shown in FIG. 2 operates in the same manner as the common base circuit shown in FIG. 1, but as shown in FIG. 2, a transistor 31 is added to form a cascode circuit.

Furthermore, in this embodiment, a common base circuit is constructed using the transistor 14 in the recording system and the transistor 26 in the reproduction system, but other circuit configurations having a wide band and a low input impedance may also be used. Good too.

Effects of the Invention As described above, according to the present invention, in a rotary head type signal recording/reproducing device, a wideband signal can be transmitted through a rotary transformer while minimizing deterioration of the wideband signal, and the wideband signal can be recorded. It can be regenerated and has great practical effects.

[Brief explanation of drawings]

Fig. 1 is a circuit diagram showing the main parts of a rotary head type signal recording/reproducing device according to an embodiment of the present invention, Fig. 2 is a circuit diagram of a base grounding circuit having a cascode circuit, and Fig. 3 is a circuit diagram of a conventional home-use FIG. 2 is a circuit system diagram for inputting and outputting signals between the main body and the rotary cylinder via the rotary transformer of the VTR. 11.24... Main body side rotary transformer, 12.23
...Rotating cylinder side transformer, 17...
- Recording amplifier, 20... Pre-reproduction amplifier. Name of agent: Patent attorney Toshio Nakao and 1 other person No. 1
figure

Claims (3)

[Claims] (1) One of the rotary transformers that connects the main unit to the rotary cylinder equipped with the recording amplifier, pre-reproducing amplifier, and head.
A rotary head type signal recording and reproducing device, characterized in that a wideband low output impedance circuit is connected to the secondary side of the transformer, and a wideband low input impedance circuit is connected to the secondary side of the transformer. (2) The rotary head type signal recording and reproducing device according to claim 1, wherein the wideband low output impedance circuit is an emitter follower circuit, and the wideband low input impedance circuit is a base grounding circuit. (3) The rotary head type signal recording and reproducing apparatus according to claim 1, wherein the wideband low input impedance circuit is a base grounded circuit having a cascode circuit.