JPS6145282B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION When a video signal and two audio signals of a television audio multiple detection signal are recorded on a tape and played back, the duty of a control signal recorded at the same time as each signal is adjusted to the state of the audio multiplex mode. The control signal is changed and recorded according to the signal and cue signal, and the control signal is obtained by reproducing the control signal during playback, and the audio multiplex mode status signal and cue signal are read out in accordance with the duty change. The present invention relates to a mode switching device for a recording/reproducing machine.

Conventional television audio multiplex signal recording and reproducing equipment records two audio signals separated by a detector using two audio tracks, and when playing back, it is determined whether the audio multiplexing mode is stereo or two languages. Therefore, the modulation mode of the TV audio multiplex modulator was selected by manually switching the mode. For this reason, the user of the recording/reproducing device has to judge and switch the audio multiplexing mode at the time of recording at the time of reproduction, making the operation complicated.

This invention was made in order to eliminate the above-mentioned conventional drawbacks. For example, the positive pulse side of a control signal used for controlling the rotational phase of a rotary head is used as a control signal, and the negative pulse side is recorded. It is an object of the present invention to provide a mode switching device for a recording/reproducing machine with excellent operability by changing the duty with a state information signal and a cueing signal and using the same for mode switching and cueing signals.

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a mode switching device for a recording/reproducing machine according to the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing the configuration of one embodiment.
In the embodiment shown in FIG. 1, the duty on the angular pulse side of the control signal is modulated by different signals depending on the recording status information signal and cue signal, and the mode is discriminated and the end or start position of the recorded program is discriminated. It has been made possible.

In FIG. 1, a differentiating circuit 2 is connected to a reference control signal input terminal 1, and the output of this differentiating circuit 2 is used to control a variable delay one-shot circuit 3.
It is connected to trigger the delay amount control circuit 5 as well as to trigger the delay amount control circuit 5. Further, 4 is a recording state information signal input terminal. The recording status information signal input terminal 4 receives recording status information representing, for example, the status of monaural audio, stereo audio, and bilingual audio using two binary bits. The recording state information signal input terminal 4 is connected to a delay amount control circuit 5, and a cueing signal input terminal 21 indicating the start of recording is also connected to this delay amount control circuit 5. The output of the delay amount control circuit 5 is connected to control the delay amount of the variable delay one shot circuit 3. The output of this variable delay one-shot circuit 3 is sent to the recording/playback selector switch 6.
The signal is supplied to a recording/reproducing control head 7 (hereinafter referred to as the head) via a fixed contact a and a movable contact.

The head 7 is adapted to come into sliding contact with a tape 8 as a recording medium. tape 8 by head 7
The control signal recorded in the recording head 7 is reproduced by the head 7 during reproduction, fast forwarding and rewinding, and is supplied to the control amplifier 9 via the movable contact and the fixed contact b of the recording/reproducing switch 6. The control amplifier 9 is connected to a rotary head control signal output terminal 11 via a waveform shaping circuit 10.
It is connected to the.

In addition, the output of the control amplifier 9 is the first one that is triggered only by the positive pulse of the reproduction control signal.
The signal is supplied in parallel to a one-shot circuit 12 and a second one-shot circuit 13 which is triggered only by negative pulses. The outputs of the first one-shot circuit 12 and the second one-shot circuit 13 are connected to a phase detector 14, and the output from the phase detector 14 is supplied to a decoder 15, as well as an integrator circuit. 22 is also sent out.

In the decoder 15, it is converted into a signal similar to a binary 2-bit recording state information signal representing recording state information at the time of recording, and this converted output is used as an audio multiplexing mode control input of an audio multiplexing modulator 16 for audio multiplexing modulation. The water is supplied to a container 16. The audio multiplex modulator 16 has an audio 2 signal input terminal 17.
is also connected. The output converted into an audio multiplex signal by the audio multiplex modulator 16 is sent to a television antenna signal modulator 18. A video signal input terminal 19 is also connected to the television antenna signal modulator 18 . A television antenna signal modulated by a video and audio signal is sent from a television antenna signal modulator 19 to a television antenna signal output terminal 20.

On the other hand, the output of the integrator 22 is sent to a recording start detection circuit 23, and the detection output detected by this recording start detection circuit 23 is taken out from a cue signal output terminal 24.

Next, the operation of the mode switching device for a recording/reproducing machine of the present invention configured as above will be explained. In explaining this operation, we will limit it to the part that is not the recording start part and use the waveform diagram shown in Figure 2.
Audio multiplexing mode switching will be explained, and cueing will be explained using the waveform diagram of FIG. 3, limited to the audio stereo mode. Reference control signal A (second
A, FIG. 3 A) is inputted and differentiated by a differentiating circuit 2 to obtain a differentiated signal C (FIG. 2 C, FIG. 3 C). The delay amount control circuit 5 is triggered by the positive pulse of the differential signal C.

Also, from the recording status information signal input terminal 4, the binary 2
For example, the signals B (Fig. 2B, Fig. 3B) of bits b ₀ and b ₁ are binary numbers "00" and "00" representing audio monaural, audio stereo, and audio bilingual, respectively.
"01" and "11" are input, and the cueing signal K (K in FIG. 2, 3 K) is input. Based on the cue signal K and signal B, the delay amount control circuit 5 outputs a signal D (FIG. 2D, FIG. 3D) synchronized with the reference control signal A. Depending on this signal D, the delay amount of the variable delay one-shot circuit 3 changes,
For example, the waveform E is determined based on the rising edge of the reference control signal A by the binary numbers "00", "01", and "11" of the recording state information signal and the cue signal K.
(Fig. 2 E, Fig. 3 E), signal A in which the duty changes only by the cue signal, and signal A in which the average duty changes by the cue signal and the duty alternates every cycle of control signal A. (b) A signal (c) is obtained in which the average duty changes depending on the cue signal and the duty alternates every two cycles of the control signal A.

That is, the change in average duty represents the cue signal, and the change in duty over several cycles represents the recording state information signal. These signals A, B, and C are the rotation control signals of the rotary head (not shown) and the recording state, which are transferred onto the tape 8 by the head 7 when the movable contact of the recording/reproduction switch 6 is turned to the fixed contact a side. A control signal including an information signal and a cue signal is recorded in association with the recording information signal.

Next, the control signal recorded on the tape 8 is played back by the head 7 with the movable contact of the recording/playback switch 6 turned to the fixed contact b side, and amplified by the control amplifier 9, which changes the duty during recording. According to the waveform E (Fig. 2 E, 3
Waveforms F (FIGS. 2F and 3F) each consisting of a positive pulse and a negative pulse are obtained in response to the rising and falling edges of FIG. E). Therefore, the waveform shaping circuit 10 uses the positive pulse side of the waveform F to obtain the signal G (FIG. 2G, FIG. 3G). This signal G is used, for example, as a rotation phase control signal for the rotary head.

Further, the signal F (FIG. 2 F, FIG. 3 F) is input to the first one-shot circuit 12 and the second one-shot circuit 13, respectively, and the first one-shot circuit 12 is triggered only on the positive pulse side of the signal F. is,
A signal H (FIG. 2 H, FIG. 3 H) is obtained. Second
The one-shot circuit 13 is triggered only on the negative pulse side of the signal F, and the signal I (Fig. 2 I, Fig. 3 I) is triggered only on the negative pulse side of the signal F.
is obtained. Between these signals I and H, a duty change component during recording is included, and by adding it to the phase detector 14, a detected signal J (J, J in FIG. 2, Figure 3 J) is obtained. This detected signal J is applied to the decoder 15, and is similar to the recording state information signal B during recording.
Converted to a base signal. By applying this signal to the audio multiplexing modulator 16 as a control signal, the audio multiplexing mode of the reproduced audio signal input from the audio 2 signal input terminal 17 is determined. The audio signal and video signal input terminal 1 are multiplexed and modulated.
By inputting both the reproduced video signals inputted from 9 to the television antenna signal modulator 18, an audio multiplexed television antenna signal is outputted to the television antenna signal output terminal 20. That is, a reproduced signal in the same mode as the audio multiplexing mode at the time of recording can be obtained as a television antenna signal. Further, by integrating the phase detection signal J with the integrator 22, a signal L (L in FIG. 3), which is the average value of the duty, is obtained.
is input. . The recording start detection circuit 23 drives a stop solenoid (not shown) to generate a signal for cueing, and the signal is output from the cueing signal output terminal 24.

As described above, according to the mode switching device for a recording/reproducing machine of the present invention, recording is performed by changing the duty of the control signal based on the recording status information signal and the cue signal, and at least one of the playback, fast forward, and rewind modes is selected. In the mode, the control signal is reproduced and its duty is detected, the recording status information signal and the cueing signal are reproduced, the mode during playback is switched by this signal, and the end of the recorded program or the cueing position is detected. As a result, stable operation can be performed without being affected by fluctuations in tape speed or power supply voltage.

Further, since one control signal, for example, a rotational phase control signal for a rotary head and a mode switching signal can be used in combination with a cueing signal, the configuration and operation of the apparatus are simplified. Furthermore, since there is no need to separately provide a track for mode switching on the tape, the tape can be used effectively and the signal recording efficiency is improved. Furthermore, since the control signal is used in conjunction with the servo signal, it has the advantage of allowing complete mode switching and cueing, which guarantees replacement with conventional devices.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the configuration of an embodiment of a mode switching device for a recording/reproducing machine according to the present invention, and FIG. 2a
2 to 2 J are signal waveform diagrams of various parts of the mode switching device of the same recording and reproducing machine limited to the portion that is not the beginning of recording, and FIGS. 3 a to 3 L are audio stereo diagrams in the mode switching device of the same recording and reproducing device, respectively. FIG. 6 is a waveform diagram of each part for explaining cueing in limited cases. 2...Differential circuit, 3...Variable delay one shot circuit recording status information signal input terminal, 5...Delay amount control circuit, 6...Record/playback selector switch, 7...Record/playback control head, 8...Tape, 10
...Waveform shaping circuit, 12...First one-shot circuit, 13...Second one-shot circuit, 14...
... Phase detector, 15 ... Decoder, 16 ... Audio multiplex modulator, 18 ... TV antenna signal modulator, 22 ... Integrator, 23 ... Recording start detection circuit.

Claims (1)

[Claims] 1. At least at the start or end portion of recording, the duty of the control signal and the type of audio multiplexed signal to be recorded are varied at different cycles so that the average value of the duty is approximately the same, and means for recording on a recording medium an average value of duty different from the duty at a recording start or end portion; and reproducing a control signal recorded on the recording medium in at least one of playback, fast forward and rewind modes. and means for detecting the period of change in the duty to determine the audio multiplexing mode at the time of recording, and for detecting the change in the average value of the duty to determine the start or end position of the recorded program. Mode switching device for recording/playback equipment. 2. The mode switching device for a recording/reproducing machine according to claim 1, wherein the control signal is used in combination as a control signal, a recording state information signal, and a cueing signal for the recording/reproducing machine.