JPS61284803A - Magnetic recording and reproducing device - Google Patents

Abstract

PURPOSE:To make it unnecessary to provide a reproducing exclusive head, and to detect the recording impossibility caused by clogging, etc., by executing a reproduction by the same head after recording. CONSTITUTION:When a signal is recording by a timing A, the signal is recorded onto a magnetic tape as shown by a recording pattern 11. The tape is not moved by a timing B, therefore, a trace is executed on the recording pattern 11. Accordingly, the recorded signal can be reproduced, and whether it is recorded correctly or not is decided by a recording impossibility detecting circuit 7. Next, by moving the tape by a timing C, a recording and reproducing head 2 is made to reach a position corresponding to a recording pattern 11', a step feed of one field portion is executed, and one cycle of intermittent recording is completed. Therefore, it is repeated and the intermittent recording is executed, and also the recording impossibility is detected.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a magnetic recording/reproducing device capable of long-term recording using an intermittent recording method, and is used, for example, for monitoring purposes.

Conventional technology In recent years, magnetic recording and reproducing devices, which have been widely used for security monitoring purposes in financial institutions, perform intermittent recording in order to perform long-term monitoring.However, these conventional devices do not automatically detect clogging of video heads. The reality is that there is no detection function, and after recording for a certain amount of time, it is played back at will and checked with the human eye. However, in general, the following recording failure detection method has been considered.

FIG. 3 shows a conventionally considered recording failure detection device for a magnetic recording/reproducing apparatus. 1 is a video recording circuit, 2
3 is a recording/reproducing head, 3 is a simultaneous reproduction head, 4 is a reproduction amplifier, 5 is a video signal demodulation circuit, 6 is a simultaneous reproduction amplifier, and 7 is a recording failure detection circuit. 0 Magnetic recording and reproduction apparatus configured as above. The operation of the recording failure detection circuit will be explained below.

First, a video signal passed through a video recording circuit 1 is recorded on a magnetic tape by a recording/reproducing head 2. The recorded portion is immediately traced by the simultaneous reproducing head 3, and the reproduced signal passes through the simultaneous reproducing amplifier 6 and is detected by the unrecordable detection circuit 7. Therefore, a separately provided reproducing head is used to determine whether or not the video signal has been correctly recorded.

Problems to be Solved by the Invention However, the above-described configuration requires a read-only head. In addition, since playback is performed at the same time as recording, there is a high risk that the recording side signal, which has a much higher level than the playback signal, will directly intrude into the playback side circuit (crosstalk), so sufficient shielding is required for both the head section and the circuit section. In view of the above problems, the present invention eliminates the need for a read-only head and solves the problem of crosstalk by playing back with the same head after recording. The present invention provides a magnetic recording/reproducing device configured to do the following.

Means for Solving the Problems In order to solve the above problems, the magnetic recording/reproducing apparatus of the present invention reproduces the recorded portion with the same head used for recording until the next recording timing. This is a magnetic recording/reproducing device characterized by detecting the inability to record due to clogging or the like.

Function The present invention uses the above-mentioned configuration to record a signal and then reproduce it using the head used for recording. Therefore, a reproduction-only head is not required, and crosstalk does not occur because simultaneous reproduction is not performed, so it is inexpensive and In practice, this results in better performance.

Embodiments Hereinafter, magnetic recording and reproducing apparatuses according to embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram of an embodiment of the present invention, and FIG. 2 shows a tape pattern.

In FIG. 1, 1 is a video recording circuit, 2 is a recording and reproducing head, 4 is a reproducing amplifier, 6 is a video signal demodulation circuit, 7 is a recording failure detection circuit, 8 is a path through which recording current flows to the head 2, and 9. is a path along which a reproduction signal flows from the head 2. Furthermore, a timing generation circuit 14 for controlling the operation of the unrecordable detection circuit 7 and the reproducing amplifier 4 is provided, so that the head 2 can perform reproduction after intermittent recording until the next recording.

In FIG. 2, 1o is a magnetic tape, 2 is the recording/reproducing head, and 11 is a recording pattern.

The operation of the magnetic recording/reproducing apparatus configured as described above will be described below with reference to FIGS. 1, 2, and 3.

First, FIG. 3 shows the timing, and reference numeral 12 indicates the timing waveform of the recording current, which indicates the timing at which the recording current 8 flows through the video recording circuit 1 of FIG. Reference numeral 13 indicates an operation timing waveform of the unrecordable detection circuit, which indicates the timing at which it is determined whether or not a signal is being recorded by the unrecordable detecting circuit 7 through the recording/reproducing head 2 in FIG. 1, through the reproducing amplifier 4. In FIG. 3, the tape moves at timing C. When a signal is recorded at timing A in FIG. 3, the signal is recorded on the magnetic tape as shown in recording pattern 11 in FIG. 2. Figure 3B
Since the tape is not moving at the timing , the recording pattern 11 in FIG. 2 is traced. Therefore, the recorded signal can be reproduced, and the unrecordable detection circuit 7 determines whether or not it has been correctly recorded. Next, C in Figure 3
Move the tape at the timing of
is brought to a position corresponding to the recording pattern 11' in FIG. 2, that is, step feeding for one field is performed. Therefore, one cycle of intermittent recording is completed. Thereafter, this process is repeated to perform intermittent recording and detect recording failure.

As described above, according to this embodiment, the timing generation circuit 1
4 and an unrecordable detection circuit 7 are provided, and by relatively controlling the operations of the recording circuit and the reproducing circuit, it is possible to detect the unrecordable state.

Effects of the Invention As described above, according to the present invention, excellent effects such as being able to detect recording failure due to head clogging etc. can be obtained with a simple circuit configuration.

[Brief explanation of drawings]

Fig. 1 is a block diagram of an embodiment of the present invention, Fig. 2 is a recording pattern on a magnetic tape, Fig. 3 is a waveform diagram showing the operation timing of the circuit, and Fig. 4 is a block diagram of a conventional example. be. 1...Video recording circuit, 2...Recording/reproduction head, 4...Reproduction amplifier, 6...Video signal demodulation circuit, 7...・Recording failure detection circuit, 1
4... Timing generation circuit. Name of agent: Patent attorney Toshio Nakao and 1 other person No. 1
Figure 3

Claims (1)

[Claims] Means for performing intermittent recording using a helical scan type recording/reproducing head and a tape step feeding mechanism;
A magnetic recording/reproducing apparatus comprising: a circuit that generates a reproduction timing during the intermittent recording; and a circuit that detects a reproduction signal at that time and determines whether or not recording is being performed.