JPH07105088B2 - Magnetic recording / reproducing device - Google Patents

Description

Description: TECHNICAL FIELD OF THE INVENTION The present invention can maintain the continuity of subcode data recorded on a recording medium even when a pause on / off operation is performed during recording. The present invention relates to such a magnetic recording / reproducing apparatus.

[Technical background of the invention and its problems]

Conventionally, as this type of device, there has been one having a configuration shown in FIG. In the figure, 1 is a mechanism unit that has a built-in head for recording / reproducing a PCM digital signal, and drives a tape running as a recording medium, and 2 is a reproducing unit for amplifying a signal picked up by the above head from the tape. An amplifier 3, a PLL circuit for extracting data from the signal through the reproduction amplifier 2, a decoder 4 for performing a process for reading the data extracted by the PLL circuit 3, and a D / for converting a digital signal into an analog signal. An A converter, 6 is a low-pass filter for removing an unnecessary high frequency component to extract an original signal, and 7 connected to the decoder 4 is a RAM for recording a digital signal.

8 is a low-pass filter that cuts high frequencies higher than the frequency included in the original signal, 9 is an A / D converter that converts the input analog signal to a digital signal, and 10 is for writing the data converted to the digital signal It is an encoder that performs processing, and is also connected to the RAM 7 described above. Reference numeral 11 is a recording amplifier that amplifies the signal encoded by the encoder 10 to a signal sufficient for recording, and 12 is a system control circuit that controls the mechanism unit 1, the decoder 4, the encoder 10, and the like.

In the figure, S ₁ is a recording / playback switching switch for selecting a recording or playback mode, S ₂ is a recording switch, S ₃ is a pause switch, and S ₄ is a subcode data recording switch.

Next, the operation of the apparatus having the above configuration will be described.

During normal reproduction, the recording / reproduction changeover switch S ₁ is on the contact a side as shown in the figure. At this time, the signal picked up by the head in the mechanism unit 1 is amplified by the reproduction amplifier 2 and then the PLL. Data extraction is performed by the circuit 3. The signal from the PLL circuit 3 is supplied to the decoder 4, where it is separated into audio data and subcode data. The separated audio data is subjected to signal processing by the RAM 7 and the decoder 4, converted into an analog signal by the D / A converter 5, and then the original signal is taken out through the low pass filter 6 and output terminal (OUT PUT ) Is output. On the other hand, the subcode data separated by the decoder 4 is input to the system control circuit 12, and the system control circuit 12 sets each condition based on the subcode data to specify the operation mode in the mechanism unit 1 or the like. It

During recording, the recording / playback changeover switch S ₁ is switched to the contact b side. Audio signal is input terminal (IN
PUT) is input to the low-pass filter 8, where high frequency components higher than the frequency included in the original signal are removed, and then supplied to the A / D converter 9 to be converted into a digital signal. The digital signal from the A / D converter 9 is processed by the encoder 10 and the RAM 7. At this time,
The addition of the subcode when the subcode data recording switch S ₄ is turned on is processed by the encoder 10 by the output of the system control circuit 12, and the audio data and the subcode data processed by this encoder 10 are passed through the recording amplifier 11. It is supplied to the head in the mechanism unit 1 and recorded on the tape.

Now, in the above apparatus, it is assumed that the recording switch S ₂ is turned on to start recording as shown in FIG. 4 (a).
Then, when the pause switch S ₃ is turned on at the time point shown in (b) of the figure after the recording is started and the pause switch S ₃ is turned off at the time point shown in (c) of the figure, the operation mode of the mechanism becomes It becomes as shown in FIG. That is, when the recording switch S ₂ is turned on, the recording state (1) is set, when the pause switch S ₃ is turned on, the recording pause state is set, and the recording standby is performed. When the pause switch S ₃ is turned off, the recording pause state is released and the recording state ( 2). At this time, since an operation delay occurs at the time of rising and falling due to the response characteristics of the mechanism, the recording state on the tape does not match the operation mode of the mechanism, as shown in FIG. That is, in the recording state on the tape, a time error T ₁ shown in FIG. 6E that does not follow the operation mode of the mechanism shown in FIG.

Since the conventional magnetic recording / reproducing apparatus for recording the subcode signal is configured as described above, the recording state on the tape causes the mechanism to operate due to the operation delay of the mechanism due to the pause on / off operation. Unnecessary waste on the tape that does not follow the mode is recorded (Fig. 4 (e))
T ₁ part of) will occur. Therefore, even if the subcode signal is continuously recorded, there is a problem that the absolute time, frame address, etc. included in the subcode data become discontinuous. In this case, it is conceivable to increase the operation speed of the mechanism or to reduce the tape running, but there is a mechanical limit, and the above-mentioned problems cannot be solved.

[Object of the Invention]

The present invention has been made in order to eliminate the above-mentioned problems of the conventional one, and by storing the subcode data in the memory once, even if the operation mode of the mechanism is changed by the pause on / off operation, it is always possible. It is an object of the present invention to provide a magnetic recording / reproducing apparatus that maintains the continuity of subcode data on a tape.

[Outline of Invention]

The magnetic recording / reproducing apparatus according to the present invention temporarily stores the subcode data from the decoder obtained by the reverse reproduction at the time of pause on / off in the memory circuit, shifts it to the comparison circuit and holds it here, and at the time of pause off. Subcode data from the decoder obtained by normal reproduction is sequentially input to the comparison circuit again via the memory circuit,
The continuity of the subcode data recorded on the tape is maintained by starting the recording on the tape from the time when the subcode data at pause on and the subcode data at pause off match. It was done.

〔Example〕

 Embodiments according to the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram showing an embodiment of a magnetic recording / reproducing apparatus according to the present invention, in which the same parts as those in FIG. 3 are designated by the same reference numerals.

In the configuration of the present invention, the memory circuit 13 for temporarily storing the subcode data separated by the decoder 4 and the pause circuit
A comparator circuit 14 for comparing the sub code data at the time of ON and at the time of pause / OFF is added.

Next, the operation of the device having the configuration shown in FIG. 1 will be described based on the timing chart shown in FIG. The operation during normal reproduction and recording is exactly the same as the conventional case described with reference to FIG.

The operation based on the pause on / off operation during recording will be described below.

When the recording switch S ₂ is turned on, the trigger signal shown in FIG. 2 (a) is input to the system control circuit 12, and the mechanism unit 1 enters the recording state by the command from the system control circuit 12 and is intervened in the recording system. Each circuit starts normal recording. Next, after the recording is started, when the pause switch S ₃ is turned on at the time point shown in FIG. 2B, the mechanism unit 1 receives the command from the system control circuit 12 as shown in FIG. Start reverse playback at the time indicated by T ₂ from the recording mode. At the same time, the subcode data from the decoder 4 is read into the memory circuit 13. This reading is performed at the timing of the control signal shown in FIG. 7E generated in the system control circuit 12 when the pause switch S ₃ is turned on. Further, in response to a command from the system control circuit 12, the subcode data from the decoder 4 read into the memory circuit 13 during reverse reproduction is shifted to the comparison circuit 14 and held there.

Then, the mechanism unit 1 shifts the mode of the mechanism to the normal direction at the time of T ₃ after the lapse of the shortest T ₂ time operating in the above-mentioned reverse reproduction mode, and stands by in the recording pause state.

Next, when the pause switch S ₃ is turned off to release the recording pause state at the time shown in FIG. 7C, the mechanism unit 1 is instructed by the system control circuit 12 to change from the standby state in the recording pause to the normal reproduction mode.
During this normal reproduction, the timing control signals shown in the diagram is generated by the system control circuit 12 based off of pause switch S ₃ (f), sequentially in the sub-code data memory circuit 13 again from the decoder 4 Read and stored. The signals read into the memory circuit 13 are sequentially input to the comparison circuit 14, and as described above, the subcode data obtained by the reverse reproduction which is already held when the pause is turned on and the normal code when the pause is turned off. Subcode data obtained by reproduction is compared.

Then, when the comparison between the two subcode data in the comparison circuit 14 is coincident with each other, the comparison coincidence output signal shown in FIG. 9G is generated, and the comparison coincidence output signal is supplied to the system control circuit 12. The system control circuit 12 instantly switches the recording / playback selector switch S ₁ from the playback side to the recording side based on the comparison match output signal from the comparison circuit 14, and instantaneously switches the circuit interposed in the other recording system. Recording starts in the recording state. At this time, if the subcode data recording switch S ₄ is turned on so that the subcode data is continuously recorded, the recording state on the tape is continuously and continuously as shown in FIG. The subcode data can be recorded by

In the above embodiment, the case where the mechanism unit 1 is set to the reverse reproduction mode and the reverse reproduction is performed at the time of pause-on has been described as an example. However, the command from the system control circuit 12 at this time is not the reverse reproduction mode, but FIG. A rewind (REWIND) mode may be used as a mode for obtaining the shortest possible time T ₂ shown in (d).

Further, the reel motor on the supply side may be rotated in the reverse direction in order to produce the time T ₂ without the rewind mode.

〔effect〕

As described above, according to the present invention, a memory circuit for temporarily storing subcode data, subcode data obtained by reverse reproduction at pause on and subcode data obtained by normal reproduction at pause off. And a comparison circuit that supplies a comparison / match output to the system control circuit when the two match, so even if the operation mode of the mechanism is changed by the pause on / off operation It is possible to record while maintaining the continuity of the subcode data. That is,
Since the continuity of the absolute time, frame address, etc. included in the subcode data is maintained, a highly accurate data can be obtained with little time information error.

In addition, the wasteful space recorded on the tape is eliminated, and further, the continuity of the audio data is improved even if the recording is once stopped and restarted during the recording of the audio data.

[Brief description of drawings]

FIG. 1 is a block diagram showing a magnetic recording / reproducing apparatus according to an embodiment of the present invention, FIG. 2 is a timing chart for explaining the operation of the embodiment of the present invention, and FIG. 3 is a conventional magnetic recording / reproducing apparatus. And FIG. 4 is a timing chart for explaining the operation of the conventional device. 1 ... Mechanism unit, 3 ... PLL circuit, 4 ... Decoder, 10 ... Encoder, 12 ... System control circuit, 13 ... Memory circuit, 14 ... Comparison circuit.

Claims (2)

[Claims] 1. A sub-code data is read from a mechanism unit having a head for recording / reproducing a digital signal and a tape drive mechanism capable of normal / reverse reproduction, and reproduction data extracted by a PLL circuit interposed in a reproduction system. A decoder to output, a memory circuit to read and temporarily store the subcode data from the above decoder obtained by reverse reproduction at the time of pause on, and a decoder that is normally reproduced from the above subcode data at the time of pause off. A comparison circuit that compares the read subcode data and outputs a comparison match output signal when the two match, an encoder that intervenes in the recording system to write the subcode data, the decoder and the memory circuit , System circuit that specifies the operation mode of the comparison circuit, encoder and mechanism unit With the troll circuit, recording of subcode data on the tape is started from the time when the pause is released and the comparison match output signal from the comparison circuit is output, and the continuity of the subcode data on the tape is maintained. A magnetic recording / reproducing apparatus characterized in that the recording is performed as follows. 2. A magnetic recording / reproducing apparatus according to claim 1, wherein the rewinding mode is set when the pause is turned on.