JPH02310862A - Magnetic recording and reproducing device - Google Patents

Abstract

PURPOSE:To automatically check a sound recording state after finishing sound recording by rewinding and reproducing a tape by a specified amount after finishing sound recording and checking fault in sound recording from the error rate of a reproducing signal at the time of above-mentioned rewinding and reproducing. CONSTITUTION:When a sound recording finishing action is completed, a device is switched to be in a rewinding mode by a system controller (microcomputer) 8 and the recording tape is rewound by the specified amount previously set. Then, the device is switched to be in a reproducing mode and reproducing the tape is started from a rewound position. The system controller 8 monitors the error rate transmitted from a signal processing circuit 3. When the error rate is larger than a threshold previously set, the controller 8 decides that sound recording is faulty and outputs a sound recording fault detection signal to a sound recording fault display unit 7. Based on the sound recording fault detection signal, the display unit 7 informs a user that sound recording is faulty on the recording tape in a specified display form. Thus, whether the sound recording state is good or not is confirmed as soon as sound recording is finished.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a digital recording type magnetic recording/reproducing device using a magnetic tape as a recording medium, a so-called DAT (digital audio tape recorder).

[Conventional technology]

With conventional DAT, the tape was stopped immediately after recording was completed. Therefore, even if recording is incomplete due to a clogged magnetic head, it is difficult to notice this.

[Problem to be solved by the invention]

Conventionally, in the above cases, the only way to check whether the recording condition was good or bad was to manually play the tape after recording and listen to the playback sound, which was a cumbersome operation and was difficult to check itself. There was also the problem that it was inaccurate.

The present invention was made in view of the above circumstances, and is a DAT that can automatically check the recording status after the recording is completed.
The purpose is to provide

[Failure to solve the problem]

In order to solve the above-mentioned problems, the present invention provides a digital recording type magnetic recording and reproducing apparatus using magnetic tape as a recording medium, so-called DAT, which automatically rewinds the tape by a certain amount after recording is completed and reproduces it. The apparatus is equipped with a rewinding and reproducing means for rewinding and reproducing, and a recording defect detecting means for detecting a recording defect of the tape from the state of the reproduction signal at the time of rewinding and reproducing.

As the recording defect detection means, a device that detects a recording defect from the error rate of the reproduced signal, a device that detects the recording defect from the envelope amplitude of the RF reproduced signal, etc. can be employed.

[For production]

When the recording is finished, the rewind playback means automatically rewinds the recording tape by a certain amount and starts playing back the tape that has just been recorded. The recording defect detection means detects whether or not the tape has a recording defect from the error rate of the reproduced signal at this time or the envelope amplitude of the RF reproduced signal.

Therefore, it is possible to check whether the recording condition is good or bad immediately after the recording is completed, and desired measures such as head cleaning or re-recording can be taken based on the detection result.

〔Example〕

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

FIG. 1 shows one embodiment of the R-DAT according to the present invention. The example shown in FIG. 1 is an example in which the quality of the recording condition is checked based on the error rate of the reproduced signal.

In the figure, A and B are two magnetic heads mounted on a rotating drum 1, 2 is an RF reproduction amplifier, 3 is a signal processing circuit, and 4 is D
/A converter, 5 is a servo circuit, 6 is a mechanism section into which a cassette tape is loaded, 7 is a recording failure indicator, and 8 is a system controller. For convenience of explanation, FIG. 1 mainly shows only the reproduction system circuit, and the recording system circuit is omitted.

Next, the operation of the above embodiment will be explained. In the case of the embodiment shown in FIG. 1, each operation specific to the present invention described below is realized in software by a system controller 8 having a built-in microcomputer.

Now, it is assumed that recording digital signals are alternately applied to two magnetic heads A and B from a recording system (not shown), and that tape recording is in progress.

When the recording is finished and the recording stop button is pressed, the system controller 8 controls the servo circuit 5, the mechanism section 6,
Controls the necessary circuits such as the recording system to cancel the recording mode and end the recording.

When the above-mentioned recording end operation is completed, the system controller 8 subsequently switches the apparatus to a rewind mode and rewinds the recording tape by a predetermined amount. and,
After rewinding the tape by a certain amount, the mode is switched to playback mode and playback of the tape is started from the rewinding position.

The RF reproduction signal read from the recording tape by the two magnetic heads A and B is sent to the signal processing circuit 3 via the RF reproduction amplifier 1, where it undergoes data demodulation, dinterleave, error correction and interpolation, etc. The signal is demodulated into the original digital signal, converted into an analog signal by the D/A converter 4, and output as an audio signal. Signal processing circuit 3
At the same time as the above playback processing, the error rate of the playback signal is calculated, and this error rate is sent to the system controller 8.

The system controller 8 monitors the error rate sent from the signal processing circuit 3, and if the error rate is larger than a predetermined threshold, it determines that there is a recording failure, and sends the recording failure detection signal to the recording failure detection signal. Output to display 7.

Based on this recording failure detection signal, the recording failure indicator 7
A predetermined display format, such as an LED, a liquid crystal, or a warning sound, informs the user that the recording tape is defective. The sequence of operations described above is shown in FIG.

If there is a warning of poor recording as described above, perform head cleaning manually or, in the case of R-DAT with a built-in head cleaning mechanism, automatically perform head cleaning. Just re-record. In addition, R-DAT with built-in head cleaning mechanism
In the case of a so-called system component that combines a CD player, compact cassette/tape player, and other audio equipment, the head cleaning is performed automatically, and then the same song from the same source is played again. It can also be configured to automatically re-record.

FIG. 3 shows another embodiment of the present invention, and is an example in which a recording defect is detected from the amplitude level of an envelope (amplitude envelope) of an RF reproduction signal. In this example, the recording failure detection means is configured in terms of hardware using an envelope detection circuit 9 and an envelope monitoring circuit 10.

Note that in FIG. 3, circuit parts that are the same as those in FIG.

When recording is performed with a clogged magnetic head on an R-DAT, the recording signal of the track corresponding to the clogged magnetic head becomes defective, and the RF signal waveform during playback becomes the waveform shown in Figure 4. becomes. That is, (
(a) The figure shows the RF playback signal waveform during normal recording recorded with a non-clogged magnetic head, (a) The figure shows the RF playback signal waveform when recording was performed with the B head clogged, (C) The figure A
, are the RF playback signal waveforms when recording was performed with both heads clogged.As is clear from figures (b) and (c), when recording was performed with the magnetic heads that were clogged, RF corresponding to a clogged magnetic head
Either no reproduced signal is obtained, or the amplitude level of the signal becomes extremely low. Therefore, by monitoring the amplitude level of the envelope of the RF reproduction signal, it is possible to detect whether or not the current recording is defective.

The envelope detection circuit 9 detects the RF signal waveforms shown in FIGS. 4(a) to (C) output from the RF reproducing amplifier 2.
The reproduced signal is combined as an input signal, and the envelope (amplitude envelope) component of this RF reproduced signal is extracted and sent to the envelope monitoring circuit IO. The envelope monitoring circuit 10 includes A, 8
The amplitude level of the envelope component of the RF reproduction signal of the two magnetic heads is detected in synchronization with the rotation period of each magnetic head, and when the amplitude level of the envelope component becomes less than a specified value, it is determined that there is a recording failure, and the system controller 8 sends a detection signal to. The system controller 8 receives this detection signal and executes the same processing as in FIG. 1.

〔Effect of the invention〕

As is clear from the above description, according to the present invention, the tape is automatically rewound by a certain amount after recording and played back, and the error rate of the playback signal at the time of rewinding and playback or the error rate of the RF playback signal is Recording defects are automatically checked based on the envelope amplitude level, so
It is no longer necessary to perform a manual playback check each time a recording is made, as is the case in the past, and the operability of this type of magnetic recording/playback apparatus can be further improved.

[Brief explanation of the drawing]

Fig. 1 is a block diagram of one embodiment of the present invention, Fig. 2 is an operation sequence diagram of the above embodiment, Fig. 3 is a block diagram of another embodiment of the invention, and Fig. 4 is an RF reproduction signal diagram. It is a signal waveform diagram. A', B...Magnetic head, 2...RF playback amplifier, 3...Signal processing circuit, 7...Recording failure indicator, Death...System controller, 9...Envelope'
Detection circuit, 10...Envelope monitoring circuit.

Claims (1)

[Claims] 1. In a digital recording type magnetic recording and reproducing device using a magnetic tape as a recording medium, a rewinding and reproducing means for automatically rewinding and reproducing the tape by a certain amount after the end of recording; What is claimed is: 1. A magnetic recording and reproducing apparatus comprising a recording defect detection means for detecting a recording defect on the tape from the state of a reproduction signal during reproduction. 2. Claim 1, characterized in that the recording defect detection means detects recording defects from the error rate of the reproduced signal.
The magnetic recording and reproducing device described above. 3. The magnetic recording and reproducing apparatus according to claim 1, wherein the recording defect detection means detects recording defects from the envelope amplitude of the RF reproduction signal.