JPH02156402A - Magnetic recording and reproducing device - Google Patents

Abstract

PURPOSE:To drastically decrease the number of signal lines by providing plural microcomputers which are so constituted as to form the signals to control operation changeover switches by detecting the data of self-channels from the signal lines. CONSTITUTION:An integration circuit 33 generates the erasing bias control voltage having inclinations at the rise and fall in response to a low-level signal when this signal is outputted from a recording and reproducing output terminal B3 by each of the respective channels. As a result, the similar erasing bias signal is obtd. from a voltage control amplifier 27. A switch 28 is subjected to ON control by a relay 34 and an erasing bias signal is applied to an erasing head 4a when an erasing period assignment signal is generated from the output terminal B4 and a transistor 34 turns on. The output terminal B5 outputs the permission signal of the input signal. Reading of data is executed by the synchronizing signal of the input terminal A2 when the channel assignment signal is inputted to the input terminal A3 of the microcomputer 8a and the operation switching data is simultaneously inputted to the input terminal A1. The computer 8a outputs the control signal to the output terminals B1 to B5. The signal line 10 is commonly used in the plural channels.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a magnetic recording and reproducing device having a multi-channel configuration, such as a multi-channel tape deck.

[Prior Art] A conventional analog multi-channel tape deck is equipped with a system control circuit that controls the entire system, and controls the operation changeover switch of the recording/playback circuit of each channel based on the output of this system control circuit. It is configured as follows.

[Problem to be solved by the invention MB] By the way, recording/reproducing switching in each recording/reproducing circuit, erasing current on/off, muting, dbx on/off, etc.
If a dedicated signal line is provided for turning off, etc., the total number of signal lines for all channels will increase considerably.For example, 1
If four signal lines are required for each channel in a six-channel tape deck, 64 signal lines are required.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a magnetic recording/reproducing circuit that can connect a main control circuit and a recording/reproducing circuit of each channel with a small number of signal lines.

[Means for Solving the Problems] The present invention for achieving the above object includes a plurality of magnetic heads corresponding to a plurality of channels, and a plurality of operation changeover switches connected to the magnetic heads. a plurality of recording and reproducing circuits; and an input device that provides a command for controlling the operation changeover switch of the plurality of recording and reproducing circuits, and data for controlling the recording and reproducing circuit based on the output of the input device. and a main control circuit configured to send a plurality of data for controlling the plurality of recording/reproducing circuits to a common signal line in a time division manner, and a main control circuit provided for each of the plurality of recording/reproducing circuits. and a plurality of microcomputers each connected to the signal line and configured to extract data of its own channel from the signal line to form a signal for controlling the operation changeover switch. It is related to equipment.

[Function] The main control circuit of the present invention transmits control data to the recording/reproducing circuit of each channel in a time-division manner. Therefore, one signal line can be shared by multiple channels, and the number of signal lines can be significantly reduced.

[Embodiment] Next, a multi-channel magnetic tape recording/reproducing apparatus according to an embodiment of the present invention will be described with reference to FIGS. 1 to 5.

FIG. 1 shows the configuration of three channels of a 16-channel magnetic tape recording/reproducing device.A recording medium magnetic tape 1 has a plurality of tracks 2a, 2b, and 2c, each track 2a,
2b, 2C, recording/reproducing magnetic heads 3a, 3
b, 3C and erase heads 4a, 4b, 4c are provided. Note that the recording/reproducing magnetic heads 3a, 3b, 3c
The erasing heads 4a, 4b, and 4c are configured as a composite head.

5a, 5b, and 5C are recording/reproducing circuits provided for each channel, which include recording/reproducing magnetic heads 3a to 3c, erasing heads 4a to 4c, recording signal input terminals 6a to 6c, and reproduction output terminal 7a for each channel. ~7c are connected to each other. Each of the recording and reproducing circuits 5a to 5C has a built-in microcomputer 8a to 8C in order to avoid switching operations digitally.

The main control circuit 9 includes recording/reproducing circuits 5a to 5c for each channel.
It centrally controls the operation switching of
11, a system clock line 12, and channel designation lines 13a to 13c corresponding to the number of channels.

FIG. 2 shows the main control circuit 9 in detail, and FIG. 3 shows the states of each part in FIG. 2. The input device 14 in FIG. It is connected to the CPU 15. Note that it is also possible to wirelessly connect the input device 14 to the CPU as a remote control section.

Based on the information given from the input device 14, the CPU 15 forms data for switching the operation in the recording/reproducing circuits 5a to 5C of each channel as shown in FIG. Channel designation data is sent to the common signal line 10 and also supplied to the interface 18 through the 8-bit parallel transmission line 17, and the synchronization signal (black and f) shown in FIG. 3(B) is sent to the NOT circuit 19. The signal is sent to the synchronization signal line 11 via the synchronous signal line 11.

The interface 18 decodes the designated channel based on the 8-bit channel designation data, and sends an analog channel designation consisting of a high level and a low level shown in FIG. It supplies signals.

A system clock generator 20 is connected to a common clock line 12 via a NOT circuit 21, and is connected to each recording/reproducing circuit 5a.
~5c is supplied with a common clock signal.

In this embodiment, the data sent from the CPU 15 to the signal line 10 is data consisting of 8 bits BO to B7, and is serially transferred within the channel designation period t1 to t2. Since there is only one signal line 10, multiple channels are used in a time-division manner.

Since the recording/reproducing circuits 5a to 5C of each channel have the same configuration, only the recording/reproducing circuit 5a of the first channel is connected to the fourth channel.
The explanation of the recording/reproducing circuits 5b and 5C of other channels will be omitted. The recording/reproducing circuit 5a has a recording input terminal 6.
It has a recording circuit 22 including a recording amplifier etc. connected to a terminal 7a, and a reproduction circuit 23 connected to a reproduction output terminal 7a. The recording circuit 22 connects the recording/reproducing magnetic head 3a via a bias trap circuit 24 and a recording/reproducing changeover switch 25.
It is connected to the. The reproducing circuit 23 is also connected to the recording/reproducing magnetic head 3a via a recording/reproducing changeover switch 25. A 145 kHz high frequency bias signal line 26 connected to a bias oscillator (not shown) is connected to the recording/reproducing magnetic head 3a via a voltage control amplifier 26a and a changeover switch 25, and is also connected to a voltage control amplifier 26a and a changeover switch 25. 27 and the erase head 4 via the erase switch 28.
connected to a.

The microcomputer 8a has input terminals A1, A2, A3, and A to which a common signal line 10, a synchronization signal line 11, a system clock line 12, and a channel designation line 13a are connected.
4, and recording bias period designation signal output terminal B1, recording period designation signal output terminal 82, erasure bias control signal output terminal B3. Erase period designation signal output terminal B4. Input/tape signal output terminal B5, erase stop signal output terminal 8
6. High/low instruction signal output terminal B7. Muting control output terminal B8, dbx on/off instruction signal output terminal sound 9.

From the output terminal 81, a recording bias period designation signal is outputted corresponding to the recording period as shown in FIG. ) in response to the signal shown in Fig. 5(B).
Generates voltage. That is, a voltage that rises with a slope and falls with a slope is generated. As a result, the amplitude of the AC bias signal obtained at the output of the voltage control amplifier 26a does not change abruptly at the rise and fall, but gradually changes.
Prevent recording of noise. A high-level recording period designation signal is output from the output terminal 82 of the microcomputer 8a at the timing shown in FIG. 5(C), and the transistor 32 connected in series to the relay 31 is turned on. When the transistor 32 is turned on, the relay 31 closes the switch 25 to contact a, and the recording current and bias signal are supplied to the magnetic head 3a.

The output terminal 83 is connected to the voltage control amplifier 27 via the erase bias control integrating circuit 33.

When the low level signal shown in FIG. 5 CD is output from the output terminal 83, the integrating circuit 33 responds to the
), an erase bias-controlled fjn voltage having slopes at rise and fall is generated.

As a result, the voltage controlled amplifier 27 provides an erasing bias signal whose amplitude gradually changes at rising and falling edges.

A relay 34 is connected in series to the output terminal B4. Connected to the base of transistor 35. Output terminal 8
When the erase period designation signals shown in FIGS. 4 to 5F are generated and the transistor 35 is turned on, the switch 28 is turned on by the relay 34, and an erase bias signal is applied to the erase head 4a. The output terminal 85 outputs a signal indicating permission of the input signal, as shown in FIG.

3<A to the input terminal A3 of the microcomputer 8a.
) is input and, at the same time, operation switching data is input to the input terminal A1, data is read by the synchronization signal at the input terminal A2. The microcomputer 8a forms a signal for setting a desired mode based on the data, and outputs a control signal as shown in FIG. 5 to output terminals 81 to B5, for example.

It is necessary to send various control signals from the output terminals 81 to B5 with a time difference, but since this time difference is set digitally in the microcomputer 8a, an analog signal can be transmitted using a conventional time constant circuit. The accuracy is higher than those set manually.

Also, the signal! Since 110 is shared by a plurality of channels, it transmits data necessary not only to the recording/reproducing circuit 5a of the first channel but also to the recording/reproducing circuits 5b, 5C of other channels. However, when the data of the song channel is being transmitted, the channel designation signal shown in FIG. do not have.

[Modifications] The present invention is not limited to the above-described embodiments, and the following modifications are possible, for example.

(1) One signal line may be added for communication from each recording/reproducing circuit 5a to 5c to the main control circuit 9.

(2) Channel designation lines 13a to 13c' @: Instead of providing them, an address may be attached to the data transmitted by the signal 110, so that only the microcomputer of the channel designated by the address reads the data.

[Effects of the Invention] As described above, according to the present invention, it is possible to transmit data from recording and reproducing circuits of a plurality of channels through a common signal line, and the number of signal lines can be significantly reduced.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing a magnetic tape recording and reproducing apparatus according to an embodiment of the present invention, FIG. 2 is a block diagram showing details of the main control circuit of FIG. 1, and FIG. 3 shows the state of each part of FIG. 2. FIG. 4 is a voltage waveform diagram showing the recording/reproducing circuit of FIG. 1, and FIG. 5 is a voltage waveform diagram showing the state of each part in FIG. 1...Magnetic tape, 3a-3c...Magnetic head for both recording and reproduction, 5a-5c...Recording and reproduction circuit, 8a-8C
...Microcomputer, 9...Main control circuit, 1
0...Common signal line, 11...Synchronization signal line, 13a~
13c...Channel designation line.

Claims (1)

[Scope of Claims] A plurality of magnetic heads corresponding to a plurality of channels, a plurality of recording/reproducing circuits connected to the magnetic heads and each having a plurality of operation changeover switches, and a plurality of recording/reproducing circuits of the plurality of recording/reproducing circuits. comprising an input device for giving a command for controlling the operation changeover switch, forming data for controlling the recording and reproducing circuit based on the output of the input device, and controlling the plurality of recording and reproducing circuits; a main control circuit configured to send out a plurality of data on a common signal line in a time-division manner; A magnetic recording/reproducing device comprising a plurality of microcomputers configured to extract data of its own channel from a plurality of microcomputers to form a signal for controlling the operation changeover switch.