JPH07176003A - Recording or reproducing device - Google Patents

Abstract

PURPOSE:To perform erasure in a short time by controlling an output based on a reproducing rate of subinformation, overwriting erasion information on the subinformation in moving a recording medium at high speed at the time of erasing information and inhibiting the information from being outputted. CONSTITUTION:A tape 2 is scanned by a drum 5 with a head 1, and a demodulation signal is generated by a reproducing demodulation circuit 13, and a video signal is specifically processed and outputted to an output circuit 18 by a signal processing circuit 14. The subinformation is detected from the demodulation signal by a detecting circuit 15. A reproducing output is inhibited by a control part 16 when a detecting rate of a subinformation part is below a prescribed rate based on a tape moving speed at the time of erasing operation. Since subinformation detecting information is larger than the prescribed rate at the time of reproducing the tape 2 executed for recording only, a reproducing video signal is outputted, and no recording is executed. A capstan 8 is driven by a driving circuit 7 with a signal of a control circuit 6. When erasure is instructed by an operating part 17, an erased signal is given to a recording signal generating circuit 11 by the control part 16 with a subinformation generating circuit 10, and is recorded on the tape 2 via a modulation circuit 12, so that only a part of information is overwritten with the erased signal.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a recording or reproducing apparatus for recording / reproducing information signals such as image signals, and more particularly to its erasing operation.

[0002]

2. Description of the Related Art Conventionally, as this type of apparatus, a VTR is known in which a rotating magnetic head scans a magnetic tape diagonally to record and reproduce a signal.

When it is desired to erase recorded information in such a VTR, a fixed head for erasing the recorded information is provided in order to quickly erase the recorded information, and the magnetic tape is faster than the normal speed. Sending erases recorded information, or sends magnetic tape faster than normal speed,
A rotary head for erasing the head width corresponding to it is provided,
For example, a method of erasing tracks formed on a plurality of magnetic tapes by one scanning is performed.

[0004]

However, in the conventional VTR as described above, when a fixed head for erasing is provided and the recorded information is erased by sending the magnetic tape faster than the normal speed, Although the erasing speed can be improved according to the feeding speed, it has a drawback that a mechanical mechanism for erasing is required. In addition, a rotary head for erasing a head width corresponding to feeding a magnetic tape faster than the normal speed is provided, and when erasing tracks formed on a plurality of magnetic tapes by one scanning, Since the head feed rate is mechanically determined by the head, the erasing rate cannot be improved.

Under the above-mentioned background, the present invention has an object to provide a recording or reproducing apparatus capable of erasing recorded information faster.

[0006]

SUMMARY OF THE INVENTION In order to solve the problems that have been conventionally encountered and to achieve the above object, the present invention provides a reproducing means for reproducing an information signal and sub information relating to the information signal, and the sub information. Is provided with a detecting means for detecting the ratio of reproduction by the reproducing means, and a control means for controlling the output of the information signal reproduced by the reproducing means based on the output of the detecting means.

[0007]

Embodiments of the present invention will now be described in detail with reference to the drawings.

FIG. 1 is a block diagram showing the configuration of a VTR as an embodiment of the present invention.

First, a normal recording operation will be described.

In FIG. 1, the drum drive section 4 drives the drum 5 in response to a control signal from the drum control circuit 3,
Two recording / reproducing heads 1 are rotated so as to obliquely scan the magnetic tape 2. Further, according to the rotation of the drum 5, a drum PG generating circuit (not shown)
A pulse is generated and the drum control circuit 3 causes the drum PG
As is well known, a pulse is used to generate a drum control signal so that the rotation phase of the drum 5 becomes constant. Further, the capstan drive unit 7 drives the capstan 8 according to a control signal from the capstan control circuit 6, and the capstan 8 transfers the magnetic tape 2. This capstan speed control uses a capstan FG pulse from a capstan FG circuit (not shown), as is well known, so that the capstan control circuit 6 sends a control signal so that the transfer speed of the tape 2 becomes constant. This is done by creating.

The recording signal processing circuit 9 subjects the video signal input by the control signal from the control unit 16 to predetermined processing and outputs it to the recording signal generation circuit 11. In addition, the operation unit 17
When the recording operation is instructed by the control section 16, the control section 16 outputs a control signal indicating the recording operation to the sub information generating circuit 10, and the sub information generating circuit 10 outputs a sub code such as a time code related to the video signal to be recorded. Information is generated and output to the recording signal generation circuit 11. The recording signal generation circuit 11 converts the video signal from the recording signal processing circuit 9 and the sub information from the sub signal generation circuit 10 into a signal of a format suitable for recording by controlling the output of each data, and the recording modulation circuit 12 Output to.
The recording modulation circuit 12 modulates the video signal and the sub information from the recording signal generation circuit 11, and the recording / reproducing head 1 records these signals on the magnetic tape 2. FIG. 2 shows a track pattern during normal recording. In the figure, sub information is recorded in the area indicated by S at the start end of each track, and V
The video signal is recorded in the area indicated by.

Next, the operation for erasing the information signal thus recorded will be described.

The control of the drum 5 is the same as during recording.

Further, the capstan control circuit 6 receives the magnetic tape 2 from the capstan FG pulse from the capstan 8.
The capstan control signal is generated so that is transferred at a higher speed than that during recording. The capstan drive circuit 7 drives the capstan 8 according to the capstan control signal.

When the erasing operation is instructed by the operating section 17, the control section 16 outputs a control signal indicating the erasing operation to the sub-information generating circuit 10 and the sub-information generating circuit 1
0 generates information indicating that the data has been erased, which is different from that at the time of recording, and outputs the information to the recording signal generation circuit 11. The recording signal generating circuit 11 generates an erasing signal from the sub information indicating that the erasing has been completed from the sub signal generating circuit 10, and outputs only the erasing signal to the recording modulating circuit 12. The recording modulation circuit 12 modulates the erasing signal from the recording signal generating circuit 11, and the recording / reproducing head 1 records the erasing signal on the magnetic tape 2. At this time, since the tape 2 is transferred by the capstan 8 at a higher speed than during recording, only a part of the sub information recorded as shown in FIG. 2 is overwritten by the erase signal. Figure 3
Is the track pattern after the erase operation.

Next, the operation of reproducing the tape 2 thus recorded or erased will be described.

The control of the drum 5 and the capstan 8 is the same as that at the time of recording described above.

The recording / reproducing head 1 scans the magnetic tape 2 with the drum 5, reproduces the signal recorded on the magnetic tape 2, and outputs it to the reproducing demodulation circuit 13. Reproduction demodulation circuit 1
Reference numeral 3 demodulates the reproduced signal from the recording / reproducing head 1 to generate a reproduced demodulated signal. The reproduction signal processing circuit 14 reproduces a video signal from the reproduction demodulation signal output from the reproduction demodulation circuit 13, performs a predetermined process on the video signal, and outputs the video signal to the reproduction output circuit 16.

On the other hand, the sub information detection circuit 15 detects sub information from the reproduction demodulation signal output from the reproduction demodulation circuit 13,
This sub information is output to the control unit 16. The control unit 16 generates a reproduction permission signal so as to prohibit the output of the reproduction video signal when the ratio at which the sub information unit can be detected is equal to or lower than a predetermined ratio based on the tape transfer speed during the erasing operation, and the reproduction output Output to the circuit 16. The reproduction output circuit section 16 controls whether to output the reproduction video signal from the reproduction signal processing circuit 14 according to the reproduction permission signal from the sub-information detection circuit 15.

Therefore, the sub-information detection circuit 15 can detect the sub-information from the reproduction demodulation signal from the reproduction demodulation circuit 13 when reproducing the magnetic tape 2 on which only normal recording is performed, which is sufficiently higher than the predetermined ratio. Therefore, a reproduction permission signal is generated so as to permit the output of the reproduction video signal, and when recording is not performed, or when the magnetic tape 2 on which the above-described erasing operation has been performed after the recording has been performed is reproduced by the erasing signal, Since the information is overwritten, the rate at which the sub-information can be detected from the reproduction demodulation signal from the reproduction demodulation circuit 13 becomes lower than a predetermined rate, so that the reproduction permission signal is generated so as to prohibit the output of the reproduction video signal. That is, when reproducing the magnetic tape 2 for which only recording has been performed, a reproduction video signal is output and recording is not executed.
Alternatively, when reproducing the magnetic tape 2 which has been erased after recording, no reproduced video signal is output.

As described above, in the present embodiment, the tape is moved at a high speed during the erasing operation, the erasing signal is overwritten on the sub information, and the video signal is detected according to the detected ratio of the sub information during reproduction. Since it is determined whether or not to output
High-speed erasing can be performed without providing any special mechanism for the erasing operation. Further, the erasing speed can be controlled by controlling the ratio of detection in the sub-information detecting circuit 15, and erasing can be performed at a higher speed than in the past.

Although the above-described embodiment has been described with respect to the case where the present invention is applied to the analog VTR, it is naturally applicable to the digital VTR and has the same operation and effect.

[0023]

As is apparent from the above description, according to the present invention, the output of the information signal is controlled according to the reproduced ratio of the sub information. In order to prohibit the output of the information signal, the ratio of the sub-information obtained at the time of reproduction is set to be equal to or lower than the outputable ratio by moving the recording medium at high speed and overwriting the erasing information on the sub-information. Therefore, the information signal can be erased substantially in a short time.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of a VTR which is an embodiment of the present invention.

FIG. 2 is a diagram showing a tape format during normal recording in an embodiment of the present invention.

FIG. 3 is a diagram showing a tape format at the time of erasing operation in the embodiment of the present invention.

[Explanation of symbols]

 10 Sub Information Generation Circuit 11 Recording Signal Generation Circuit 14 Reproduction Signal Processing Circuit 15 Sub Information Detection Circuit 16 Reproduction Output Circuit

Claims (3)

[Claims] 1. A reproducing device for reproducing sub-information relating to the information signal together with an information signal, a detecting device for detecting a ratio of the sub-information reproduced by the reproducing device, and the detecting device based on an output of the detecting device. A reproduction device comprising: a control unit that controls the output of the information signal reproduced by the reproduction unit. 2. A recording / reproducing apparatus having a plurality of modes, wherein in the first mode, first sub-information related to the information signal is recorded on the recording medium together with the information signal, and in the second mode. , Second according to the first sub-information
Recording means for recording the sub-information of the sub-information on the recording medium at a predetermined ratio, reproducing means for reproducing the first and second sub-information together with the information signal, and reproducing the first sub-information by the reproducing means. A recording / reproducing apparatus, comprising: a detection unit that detects the generated ratio; and a control unit that controls the output of the information signal reproduced by the reproduction unit based on the output of the detection unit. 3. The recording apparatus according to claim 2, wherein the first mode is a normal recording mode and the second mode is an erasing mode.