JPH0442403A - Recorder and recording/reproducing device for rectangular wave - Google Patents

Abstract

PURPOSE:To simplify circuit configuration by providing a change-over switch whose terminal to be selected is connected to a positive voltage source and a negative voltage source, a means to control the change-over switch based on an input rectangular wave signal, and a magnetic head. CONSTITUTION:The change-over switch 11 is comprised of serially connected analog switches 11a, 11b, and outputs a positive voltage V+ and a negative voltage V- selectively, and the output of the switch is supplied to the magnetic head 16 via an adjusting resistor 13 and diodes 14, 15. A mode control circuit 12 consists of AND gates 12a, 12b, and for example, the AND gate 12a controls the analog switch 11a and the AND gate 12b controls the analog switch 11b based on an input time code signal. Also, the magnetic head 16 scans a magnetic tape 10, and records the data of a time code, etc., on the magnetic tape 10, and also, reproduces the data of a recorded time code, etc. In such a way, the information of the time code, etc., can be recorded on the magnetic recording medium 10 without necessitating a recording amplifier.

Description

Detailed Description of the Invention A. Industrial Application Field The present invention relates to a rectangular wave recording device that records a rectangular wave signal on a magnetic recording medium, and a rectangular wave recording device that records a rectangular wave signal on a magnetic recording medium, or a rectangular wave that has been recorded. The present invention relates to a rectangular wave recording and reproducing device that reproduces signals.

88 Summary of the Invention The rectangular wave recording device according to the present invention includes a changeover switch whose first selected terminal is connected to a positive voltage source and whose second selected terminal is connected to a negative voltage source, and a switching switch input. Power amplification used in conventional rectangular wave recording and reproducing devices is achieved by comprising a control means that performs switching control based on a rectangular wave signal, and a magnetic head that is supplied with an output signal of a changeover switch and scans a magnetic recording medium. The circuit configuration is simpler than the conventional one, requiring a separate recording amplifier.

Further, in the rectangular wave recording and reproducing apparatus according to the present invention, the first changeover switch selects and outputs a positive voltage and the negative voltage based on the input rectangular wave signal, and the first switch selects and outputs the positive voltage and the negative voltage based on the input rectangular wave signal. The second output selects and outputs the output and the ground point.
When the changeover switch and the terminals of opposite polarity are connected to each other, the first and second diodes, one end of which is connected to the output of the second changeover switch, and one end of which is grounded, a magnetic head whose other end is connected to the other ends of the first and second diodes and scans the magnetic recording medium; and a regenerative amplifier connected to the connection point between the 6FF air head and the first and second diodes. By being equipped with this, there is no need for a recording amplifier for power amplification used in conventional rectangular wave recording/reproducing devices, and there is no need for a changeover switch to switch between recording mode and playback mode. This makes it possible to improve the S/N ratio of the reproduced signal.

C1 Conventional technology Magnetic recording media, such as the magnetic tape of a video tape recorder, contain so-called control pulses and other signals used for servo control of the tape speed and switching control of the magnetic head, in addition to the main signals of video and audio signals. For example, information (data) such as a so-called time code used during editing, etc. to manage recorded video signals, etc. is recorded as the direction of a rectangular wave-like FFI field (hereinafter referred to as a rectangular wave signal), Alternatively, recorded information such as time code is played back.

For example, a conventional rectangular wave recording/reproducing device that records time codes on a magnetic tape or reproduces time codes recorded on a magnetic tape has a magnetic head 51 that scans a magnetic tape 50 and a magnetic head 51 that scans a magnetic tape 50, as shown in FIG. , a recording amplifier 52 which amplifies the input time code signal supplied through the terminal 41 and supplies an excitation current to the magnetic terminal 52, and amplifies the reproduction signal from the magnetic terminal 51. A playback amplifier 54, switches 55, 56, and a changeover switch 57 are controlled by a mode control signal supplied via a terminal 42 to switch between recording and playback operations.

The recording amplifier 52 amplifies the input time code signal supplied via the terminal 41, and connects the input time code signal to the magnetic node 51 via an adjustment resistor 53 that adjusts the excitation current.
The excitation current is supplied to -4.

Further, the magnetic head '51 is configured to receive an IJ+magnetic current corresponding to the time code from the recording amplifier 52 at one end, and output a repeat signal from the other end.

The switch 55 grounds the reproduction signal output end of the magnetic head 51 during a recording operation (hereinafter referred to as a recording mode), and the switch 56 connects the magnetic head 51 to the ground during a reproduction operation (hereinafter referred to as a reproduction mode). Encouragement of Ti
The current input terminal is grounded, and the changeover switch 57 is adapted to ground the input terminal of the recording amplifier 52 in the reproduction mode.

That is, in the rectangular wave recording/reproducing apparatus having the above configuration, in the recording mode, the input terminal of the recording amplifier 52 is set to a terminal based on, for example, the high level (hereinafter referred to as F level) of the mode control signal supplied via the terminal 42. 41 side, the switch 56 is controlled so that the excitation current input end of the magnetic head 51 is not grounded, and the switch 56 is controlled so that the reproduction signal output end of the magnetic head 51 is connected to the 1r side. 55. Then, the signal is amplified by a time code F' signal recording amplifier 52 supplied through a terminal 41 and converted into a rectangular wave signal, that is, an excitation current for the magnetic head 51. An excitation current is supplied to the magnetic head 51. As a result, an im code is recorded on the magnetic tape 50 by changing the direction of the magnetic field from the magnetic head 51 in the direction of the rectangular-wave n field.

On the other hand, in the reproduction mode, the rectangular wave recording/reproducing apparatus having the above-mentioned configuration, based on the low level (hereinafter referred to as L level) of the mode control signal supplied via the terminal
The switch 56 is controlled so that the excitation current input terminal of the magnetic head 51 is grounded, and the switch 55 is controlled so that the reproduction signal output terminal of the magnetic head 51 is not grounded. The changeover switch 57 is controlled so that the input terminal of the recording amplifier 52 is grounded to prevent noise from being added to the low-level reproduction signal.

Then, the reproduction signal from the magnetic head 51 is transmitted to the reproduction amplifier 5.
4 and output from terminal 43.

D0 Problems to be Solved by the Invention As described above, the conventional rectangular wave recording/reproducing device requires a recording amplifier 52 for power amplification that amplifies and converts the input time code signal into an excitation current for the magnetic head, and the circuit configuration is It was complicated. Further, switches 55, 56 and a changeover switch 57 for switching between the recording mode and the reproduction mode were also required, making the circuit configuration complicated. Furthermore, in the reproduction mode, since the excitation current input terminal of the magnetic head 51 is grounded using the switch 56 as described above, it cannot be completely grounded due to the contact resistance, and the S/N of the reproduction signal deteriorates. In addition, there are problems such as so-called fog, in which noise is added to the repeating signal.

The present invention was made in view of the above circumstances, and aims to provide a rectangular wave recording device that does not require a recording amplifier for power amplification in order to record information such as time codes on a magnetic recording medium. At the same time, there is no need for a recording amplifier or a mode switch for switching between recording mode and playback mode, and by completely grounding one end of the magnetic head, the S/N of the playback signal can be improved, compared to conventional methods. An object of the present invention is to provide a rectangular wave recording/reproducing device with a small number of parts.

80 Means for Solving the Problems In the rectangular wave recording device according to the present invention, in order to solve the above problems, the first selected terminal is connected to a positive voltage source, and the second selected terminal is connected to a positive voltage source.
a selector switch whose selected terminal is connected to a negative voltage source;
The present invention is characterized in that it includes a control means for switching and controlling the changeover switch based on an input rectangular wave signal, and a magnetic head to which an output signal of the changeover switch is supplied and scans a magnetic recording medium.

Further, in order to solve the above problems, the rectangular wave recording/reproducing apparatus according to the present invention includes a first changeover switch that selects and outputs a positive voltage or a negative voltage based on an input rectangular wave signal, and a recording/reproducing control. a second changeover switch that selects and outputs the output of the first switch and the ground point based on a signal; terminals having opposite polarities are connected to each other; first and second diodes connected to the output of the switch, one end of which is grounded, and the other end of which is connected to the other ends of the first and second diodes, and a magnetic head that scans a magnetic recording medium; , the magnetic head and the first
, a second diode, and a regenerative amplifier connected to the connection point with the F1 function.In the rectangular wave recording device according to the present invention, the changeover switch is switched and controlled based on a human-powered rectangular wave signal. By doing so, a positive voltage from a positive voltage source or a negative voltage from a negative voltage source is switched and applied to the magnetic head, and a rectangular wave signal is recorded on the magnetic recording medium.

Further, in the rectangular wave recording/reproducing apparatus according to the present invention, in the recording mode, the first changeover switch is switched and controlled ffj based on the input rectangular wave signal, so that the positive voltage from the positive voltage source or the negative voltage source is controlled. A negative voltage is switched and applied to the magnetic head via first and second diodes whose terminals of opposite polarity are connected to each other, thereby recording a rectangular wave signal on a recording medium. At this time, by applying a voltage sufficiently larger than the forward voltage of the first and second diodes to the magnetic head from a positive voltage source or a negative voltage source, the first and second diodes are brought into a conductive state. , a rectangular wave signal can be recorded on the magnetic recording medium by the magnetic head, and in the reproduction mode, the level of the reproduction signal from the magnetic head is lower than the forward voltage of the first and second diodes, and the first , the second diode is cut off, the reproduced signal is supplied to the regenerative amplifier without being clipped, and the amplified reproduced signal is output.

G. Embodiments Hereinafter, embodiments of a rectangular wave recording device and a rectangular wave recording/reproducing device according to the present invention will be described with reference to the drawings.

In addition to main signals such as video signals and audio signals, magnetic recording media, such as magnetic tape, contain so-called control pulses used for servo control of tape speed and switching control of magnetic heads, as well as pulses used for editing, etc. , Information (data) such as so-called time codes for managing recorded video signals, etc. is recorded as the direction of a rectangular wave magnetic field (hereinafter referred to as a rectangular wave signal), or information such as time codes that are recorded. is now being played.

As described above, the first embodiment of the rectangular wave recording/reproducing apparatus which records information such as time code as a rectangular wave signal on a magnetic tape or reproduces recorded information such as time code is shown in FIG. As shown, a changeover switch 11 that selects and outputs a positive voltage V from a positive voltage source and a negative voltage V- from a negative voltage source, and data supplied through terminals 1.2, For example, a mode control circuit 12 that controls the changeover switch 11 based on an input time code signal and a mode control signal is connected to terminals of opposite polarity, and one end is connected to the changeover switch 11 through an adjustment resistor 13. A diode 14.15, the other end of which is connected to the magnetic head 16, is connected to the output of the magnetic tape 10 for recording data such as a time code on the magnetic tape 10 or for reproducing data such as a recorded time code. The magnetic head 16 scans the magnetic head 10, and a reproduction amplifier 18 that amplifies the reproduction signal from the magnetic head 16.

The changeover switch 11 has two switches connected in series.
Consisting of two analog switches lla and llb, one end of the analog switch lla is connected to a positive voltage source (■,), and one end of the analog switch llb is connected to a negative voltage source (
(2)-), and selects and outputs a positive voltage V and a negative voltage V-. This changeover switch 1
The output of 1 is the excitation 4ffi supplied to the magnetic head 16.
The Ti current is supplied to the magnetic head 16 via the adjusting resistor 13 and the diodes 14 and 15, which adjust the Ti current value of the t current. The configuration of this changeover switch 11 is an analog switch Ila as shown in FIG.

Instead of connecting the selected terminals of the analog switches 11b and connecting the selected terminals to each voltage source, the selected terminals of the analog switches lla and llb are connected to each other and the selected terminals are connected to each voltage source. It may also be configured such that they are connected.

The mode control circuit 12 is composed of, for example, two logical sum (hereinafter referred to as AND) gates 12a and 12b, and is based on, for example, an input time code signal and a mode control signal supplied via the terminals 1.2, respectively. The AND gate 12a controls the analog switch Ila, and the AND gate 12b controls the analog switch Ilb.

The magnetic head 16 has one end grounded, and the other end connected to the reproduction amplifier 18 via the diode 14, 15 and the resistor 17.
to scan the time code and other data onto the magnetic tape 1.
0, and also reproduces the recorded data such as time code.

That is, in this rectangular wave recording and reproducing apparatus, when recording data, such as a time code, on the 6n tape 10 (hereinafter referred to as recording mode), the mode control III is input via the terminal 1.
[The time code signal supplied to jIN+2 is recorded on the magnetic tape IO as a rectangular wave magnetic field direction (hereinafter referred to as a rectangular wave signal), and when the time code recorded as this rectangular wave signal is reproduced (referred to as playback mode) , the rectangular wave signal recorded on the magnetic tape lO is taken out from the terminal 3 as a signal obtained by differentiating the rectangular wave signal.

Next, the specific operation of this rectangular wave recording/reproducing apparatus will be explained.

First, the operation when recording, for example, a time code on the magnetic tape 10 will be explained.

The mode control circuit I2 operates an AND gate 12a based on the high level (hereinafter referred to as 1 level) of the mode control signal supplied via the terminal 2 so that the time code signal supplied via the terminal l passes through as is. At the same time, the AND gate 12b is gated so that the time code signal is inverted and passed through, and the analog switch lla is controlled by this time code signal. ) controls the analog switch llb.

That is, analog switch lla.

The changeover switch 11 consisting of 11b is controlled by a time code signal, and for example, when the time code signal is at H level, the analog switch lla is turned on, the analog switch llb is turned off, and the positive voltage from the positive voltage source is turned off. When the time code signal is low level (hereinafter referred to as L level), the analog switch lla is in the OFF state, and the analog switch llb is in the ON state.
state and outputs a negative voltage - from a negative voltage source.

These positive voltages V or negative voltages - are applied to the excitation coil of the magnetic head 16 via the adjustment resistor 13 and diodes 14 and 15.

By the way, when recording a rectangular wave signal on the magnetic tape 10, a large excitation current is required, and the diode 14.1
For example, a voltage sufficiently large compared to the forward voltage of silicon diode, approximately 0.7 cm, is applied from the changeover switch 11 to the magnetic head 16. Therefore, the diodes 14 and 15 become conductive, and the excitation M1 current from the changeover switch 11 flows into the excitation coil of the magnetic head 16. As a result, the time code is recorded on the magnetic tape IO as a rectangular wave signal.

Next, the operation when reproducing, for example, a time code recorded as a rectangular wave signal on the magnetic chip 110 will be explained.

In the mode control circuit 12, based on the L level of the mode control signal supplied via the terminal 2, the AND gate 12a
, 12b becomes L level.

As a result, the mode control circuit 12 controls both analog switches lla and llb of the changeover switch 11 to be in the OFF state. That is, the recording side circuit connected to the magnetic head 16, that is, the diode 14, 15 has a high impedance when viewed from the magnetic head 16.

Thus, the magnetic head 16 receives ■1 from the magnetic tape lO.
A reproduction signal is generated by detecting the change in density, and this reproduction signal is supplied to the reproduction amplifier 1B via the resistor 17 without being crimped by the diodes (14, 15).

The reproduction amplifier 18 amplifies the reproduction signal and outputs the amplified reproduction signal via the terminal 3.

Note that the reproduced signal output from the magnetic head 16 is obtained as a waveform obtained by differentiating a rectangular wave signal, and at the subsequent stage of the terminal 3,
An integrating circuit, a low-pass filter, an equalizer, a comparator, etc. (not shown) are connected, and these circuits convert the reproduced signal, which has a differential wave of the rectangular wave signal, into binarized reproduced data, that is, the time code. It is set to be played.

As described above, in this rectangular wave recording/reproducing apparatus, the changeover switch 11 is controlled based on, for example, a time code signal supplied via the terminal l. By supplying the voltage V- to the magnetic head 16 through diodes 14 and 15 whose terminals have opposite polarities connected to each other, time codes can be generated without the need for a recording amplifier unlike conventional rectangular wave recording/reproducing devices. can be recorded on the magnetic tape 10. Also,
In the recording mode, the positive voltage v9 and the negative voltage V are sufficiently larger than the forward voltage of the diode 14.15, and the diode 14.15 becomes conductive, causing an excitation current ft to flow through the excitation coil of the magnetic head 16. It is possible to record data such as a time code on the magnetic tape 10. Further, in the reproduction mode, the diodes 14 and 15 become high impedance when viewed from the magnetic spatula 1 and 16, and the recording side circuit becomes disconnected. As a result, the reproduction signal from the magnetic herad 16 can be amplified and output by the reproduction amplifier 18 without being clipped by the diodes 14 and 15. Further, since the ground end of the magnetic head 16 is not grounded through a switch as in conventional rectangular wave recording and reproducing devices, but is directly grounded, the S/N of the reproduced signal does not deteriorate.

Next, a second embodiment of the rectangular wave recording/reproducing apparatus according to the present invention will be described.

In this rectangular wave recording/reproducing apparatus, as shown in FIG. 2, a positive voltage V from a positive voltage source and a negative voltage V from a negative voltage source
- a changeover switch 21 that selects and outputs the output of the changeover switch 21 and a ground point; a changeover switch 23 that selects and outputs the output of the changeover switch 21 and the ground point; A mode control circuit 22 that controls the changeover switch 21 based on the mode control signal and controls the changeover switch 23 based on the mode control signal supplied via the terminal 6, and terminals of opposite polarity are connected to each other, Diodes 25 and 26, one end of which is connected to the output of the changeover switch 23 via the adjustment resistor 24 and the other end connected to the magnetic herad 27, record information (data) such as a time code on the magnetic tape 20, or the magnetic head 27 that scans the magnetic tape 20 in order to reproduce recorded data such as time code, and the magnetic head 2;
and a reproduction amplifier 29 for amplifying the reproduction signal from 7.

The changeover switch 21 has two switches connected in series.
One end of the analog switch 21a is connected to a positive voltage source (■,), and one end of the analog switch 21b is connected to a negative voltage source (■,).
V-), and selects and outputs a positive voltage (2) and a negative voltage (2). This changeover switch 2
The output of 1 is supplied to the changeover switch 23.

Further, the changeover switch 23 is composed of two analog switches 23a and 23b connected in series, one end of the analog switch 23a is connected to the output of the changeover switch 21, and one end of the analog switch 23b is a ground point. The output of the changeover switch 21 and the ground point are selected and output. The output of this changeover switch 23 is the excitation mW supplied to the magnetic head 27.
The current is supplied to the corresponding irradiation head 27 via the adjustment resistor 24 for adjusting the current value of the current and the diodes 25, 26.

The mode control circuit 22 also receives, for example, a manual time code signal supplied via the terminals 5 and 6, respectively.
Consisting of negative logic circuits 22a and 22b each outputting a negative logic (hereinafter referred to as an inverted signal) of a mode control signal,
The analog switch 21a is controlled by a human time code signal, the analog switch 21b is controlled by an inverted time code signal, the analog switch 23a is controlled by a mode control signal, and the analog switch 23b is controlled by an inverted mode control signal. It looks like this.

Further, the magnetic helad 27 has one end grounded, the other end connected to the diode 25, 26, and the resistor 2
The magnetic tape 20 is connected to the reproducing amplifier 29 via the magnetic tape 20, and a time code, for example, is recorded on the magnetic tape 20, and the recorded time code is reproduced.

That is, in this rectangular wave recording/reproducing device 1, when recording data, for example, a time code, on the magnetic tape 20, the time code signal supplied via the terminal 5 follows the direction of the wave-shaped magnetic field of the magnetic tape 20. (hereinafter referred to as a rectangular wave signal), and when reproducing the time coat recorded as this rectangular wave signal, the rectangular wave signal recorded on the magnetic tape 20 differentiates the rectangular wave signal (No. 3 is a terminal It is designed to be taken out from 7.

Next, the specific operation of this rectangular wave recording/reproducing apparatus will be explained.

First, the operation when recording a time code on a 4fi tape 10, for example, will be explained.

For example, when the time code signal supplied via the terminal 5 is at H level, the mode control circuit 22 turns the analog switch 21a ON and the analog switch 21b OFF.
When the time code signal is at L level, the analog switch 21a is controlled to be in the OFF state, and the analog switch 21b is controlled to be in the ON4f state. That is, the changeover switch 2 consists of analog switches 21a and 21b.
1 is controlled by a time code signal, for example, when the time code signal is 1 level, it outputs a voltage V from a positive voltage source, and when the time code signal is at L level,
Outputs voltage ■- from a negative voltage source. Also, at the same time,
When the mode control signal supplied via the terminal 6 is, for example, at H level, the mode control circuit 22 turns on the analog switch 23a and turns the analog switch 23b into an ON state.
is controlled to be in the OFF state, and when the mode control signal is at L level, the analog switch 23a is controlled to be in the OFF state, and the analog switch 23b is controlled to be in the ON state. Then, in the recording mode, the output of the changeover switch 21 is selected and output.

These positive voltages (1) or negative voltages (V-) are applied to the excitation coil of the magnetic head 27 via the adjustment resistor 24 and diodes 25, 26.

By the way, as mentioned above, when recording a rectangular wave signal on the magnetic tape 20, a large excitation current is required, and the forward voltage of the diodes 25 and 26, for example, is about 0.7V, which is the forward voltage of a silicon diode. Then, a sufficiently large voltage is applied from the changeover switch 21 to the magnetic radar 27. Therefore, the diodes 25 and 26 become conductive, and the excitation tn current from the changeover switch 21 flows into the excitation coil of the magnetic head 27. As a result, the magnetic tape 20
The time code is recorded as a square wave signal.

Next, the operation when reproducing, for example, a time code recorded as a rectangular wave signal on the magnetic chip 120 will be explained.

The mode control circuit 22 controls the analog switch 23a of the changeover switch 23 to be in the OFF state and the analog switch 23b to be in the ON state based on the L level of the mode control signal supplied via the terminal 6. That is, the recording side circuit connected to the magnetic head 27 is connected to the magnetic head 27.
When viewed from above, it is grounded via the diodes 25 and 26 and the adjustment resistor 24.

Thus, the magnetic head 27 receives 1n from the magnetic tape 20.
A reproduction signal is generated by detecting the east density change, and this reproduction signal is supplied to the reproduction amplifier 29 via the resistor 2B.

The reproduction amplifier 29 amplifies the reproduction signal and outputs the amplified reproduction signal via the terminal 7.

By the way, the reproduced signal output from the magnetic head 27 is obtained as a waveform obtained by differentiating the rectangular wave No. 13, and its level (
The peak value) is sufficiently smaller than the forward voltage of the diodes 25, 26, and the diodes 25, 26 are in a cut-off state. Therefore, the recording side circuit is disconnected by the diodes 25 and 26, and the reproduction signal from the magnetic herad 27 is not talimbed and is sent to the reproduction amplifier 2.
9 and is amplified and output from terminal 7.

Furthermore, as described above, by grounding the recording side circuit via the adjustment resistor 24, it is possible to prevent external noise from entering the reproduced signal.

Note that, as in the first embodiment described above, an integrating circuit, a low-pass filter, a comparator, a comparator, etc. (not shown) are connected to the subsequent stage of the terminal 7, and these circuits generate a rectangular wave signal. The reproduced data, that is, the time code, is reproduced from a reproduced signal having a differential wave.

As described above, in this rectangular wave recording and reproducing apparatus, the changeover switch 21 is controlled based on, for example, a time code signal supplied via the terminal 5, and the changeover switch 21 is controlled to have a positive voltage V or a negative voltage V from the changeover switch 21. - is supplied to the magnetic head 27 through diodes 25 and 26 whose terminals have opposite polarities connected to each other, thereby eliminating the need for a recording amplifier unlike conventional rectangular wave recording/reproducing devices, and allowing time codes, etc. data can be recorded on the magnetic tape 20. In addition, in the recording mode, the above-mentioned positive voltage 0 and negative voltage 2- are sufficiently larger than the forward voltage of the diode 25.26, and the diode 25.26 becomes conductive, and the excitation coil of the magnetic node 27 Excitation current can flow,
Data such as time codes can be recorded on the magnetic tape 20. In addition, in the reproducing mode, the level of the reproducing signal from the magnetic node 27 is sufficiently lower than the forward voltage of the diode 25, 26, and the diode 25, 26 is cut off, and the diode 25 is
．． 26 is in a grounded state. As a result, the reproduction signal from the magnetic head 27 can be amplified and outputted by the reproduction amplifier 29 without being clipped by the diodes 25 and 26, and by grounding the diodes 25 and 26, the external It is possible to prevent noise from entering. Furthermore, since the grounding end of the magnetic head 27 is directly grounded, rather than through a switch as in conventional rectangular wave recording/reproducing devices, the S/N of the reproduced signal is not degraded. H0 Effects of the Invention As is clear from the above explanation, in the rectangular wave recording device according to the present invention, the first selected terminal is connected to a positive voltage source, and the second selected terminal is connected to a negative voltage source. By controlling the selected changeover switch based on information such as a rectangular wave signal, such as a time code, and supplying the output signal of the changeover switch to a magnetic head that scans a magnetic recording medium, the conventional rectangular wave recording/reproducing device can be improved. so you don't need a recording amplifier,
Information such as time codes can be recorded on magnetic recording media.

Further, in the rectangular wave recording and reproducing apparatus according to the present invention, the first changeover switch that selects and outputs the positive voltage and the negative voltage is controlled based on the input rectangular wave signal, and the above-mentioned voltage is controlled based on the recording and reproducing control signal. A second selector switch that selects and outputs the output of the first switch and the ground point is controlled;
The output of the changeover switch is supplied to the magnetic head that scans the magnetic recording medium via first and second diodes whose terminals with opposite polarities are connected to each other, and whose ends are grounded. By amplifying the reproduction signal with a reproduction amplifier, the first and second diodes become conductive during recording operation, and a positive or negative voltage corresponding to the input rectangular wave signal is applied to the excitation coil of the magnetic head. can be applied, and information such as a time code can be recorded on a magnetic recording medium. Also, during reciprocating operation,
The first and second diodes are cut off, and the recording side circuit can be disconnected, so that the reproduction signal from the magnetic node can be amplified by the reproduction amplifier without clipping, and the signal recorded on the magnetic recording medium can be amplified by the reproduction amplifier without clipping. Information such as time code can be reproduced.

Also, at this time, one end of the first and second diodes is connected to the second
Since it is grounded by the changeover switch, it is possible to prevent external noise from entering the reproduced signal. In other words, unlike conventional methods, there is no need for a recording amplifier or a mode switch for switching between recording mode and playback mode, and by completely grounding one end of the magnetic head, the S of the reproduced signal can be reduced compared to conventional methods. /N can be improved. In other words, the number of parts and harnesses can be reduced, the mounting area can be reduced, the cost can be reduced, and the reliability can be improved compared to the conventional technology.

[Brief explanation of the drawing]

FIG. 1 is a block circuit diagram of a first embodiment of a rectangular wave recording/reproducing apparatus according to the present invention, and FIG. 2 is a block circuit diagram of a second embodiment of a rectangular wave recording/reproducing apparatus according to the present invention. Yes, the 3rd V is a block circuit V of a conventional rectangular wave recording/reproducing device.
It is. 10, 2 11.2 12.2 14, 1 16.2 18.2 0... Magnetic tape l, 23... Selector switch 2... Mode control n concave path 5.25.26 ・... Diode 7 ... Magnetic head 9 ... Reproduction amplifier

Claims (2)

[Claims] (1) A changeover switch in which a first selected terminal is connected to a positive voltage source and a second selected terminal is connected to a negative voltage source, and control for switching and controlling the changeover switch based on an input rectangular wave signal. A rectangular wave recording device comprising: a magnetic head that is supplied with the output signal of the changeover switch and scans a magnetic recording medium. (2) a first selector switch that selects and outputs a positive voltage or a negative voltage based on an input rectangular wave signal; and selects an output and a ground point of the first switch based on a recording/playback control signal; a second changeover switch that outputs an output signal; first and second diodes whose terminals having opposite polarities are connected to each other and whose one ends are connected to the output of the second changeover switch; and whose one ends are grounded. and the other end is connected to the other ends of the first and second diodes, and is connected to a magnetic head that scans the magnetic recording medium, and a connection point between the magnetic head and the first and second diodes. What is claimed is: 1. A rectangular wave recording and reproducing device comprising: a reproducing amplifier;