JPH04321990A - Magnetic recording and reproducing device - Google Patents

Abstract

PURPOSE:To allow recording of a retrieving code for each one recording even at the time of discontinuous recording such as an intermittent recording and to allow the execution of a retrieving operation at the time of reproduction by using the retrieving code comprised of combinations of single frequency. CONSTITUTION:By a switch B, at the time of a continuous recording, an audio signal part and a modulation part 7 are connected, and at the time of the discontinuous recording, a single frequency generator 12 and the modulation part 7 are connected. In the case of the latter, by the command from a micro-computer 4, the single frequency is recorded on the hi-fidelity track of a magnetic tape 9, and by the micro-computer 4, the retrieving codes are provided by making the combinations for each one field. At the time of the reproduction, signals are read from the tape 9 by an audio head 5, and the single frequency is taken out via a demodulator 8 and a circuit part 10. Then, the single frequency is converted to a voltage by a F/V converter 11 ; and by the micro-computer 4, the single frequency is detected from the voltage value, a counter value is reset by a blank recording, and in reading the subsequent signals the retrieving codes are read out.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic recording and reproducing apparatus that is capable of performing a search operation even when recording is not performed continuously, such as during intermittent recording.

0002

2. Description of the Related Art FIG. 5 is a block diagram of a control signal and audio signal processing section of a conventional magnetic recording and reproducing apparatus. In the figure, 1 is a control head, 2 is a control signal (hereinafter referred to as CTL) amplifier, 3 is a circuit section that changes the duty ratio of the CTL signal, and 4 is a microcomputer that controls the operation of the system. 5 is an audio head, 6 is an audio signal amplifier section, a modulating section 7 and a demodulating section 8 are switched to the PB side during playback by a switch a;
Furthermore, during recording, it is connected to the audio signal amplifier 6 by switching to the REC side. 9 indicates a magnetic tape on which CTL signals and audio signals are recorded.

[0003] The retrieval system in conventional magnetic recording and reproducing devices generally uses the CTL recording method. In this method, at the time of recording, the circuit unit 3 changes the duty ratio of the CTL signal in response to a command from the microcomputer 4 to change the duty ratio of the CTL signal, and the signal is recorded on the magnetic tape 9 through the amplifier unit 2. This recorded CTL signal is determined as a "0" or "1" pulse depending on the duty ratio.

[0004] The microcomputer 4 combines several of these signals to create a search code, so when recording the search code,
Continuous recording for a certain period of time is definitely required. By the way,
In the case of VISS method of CTL recording method, 63
bit and approximately 2 seconds).

During reproduction, the CTL signal recorded by the control head 1 is read out, amplified by the CTL amplifier 2 and circuit section 3, and waveform-shaped, and then input to the microcomputer 4, so that the microcomputer converts the CTL signal to "0". , "1" pulse combination to execute the search operation.

On the other hand, in the conventional magnetic recording and reproducing apparatus, the audio signal processing section has no relation to the search function, and during recording, the input audio signal is modulated by the modulation section 7 and amplified by the audio signal amplifier 6. Recording is performed on a magnetic tape 9 by an audio head 5 attached to a rotating drum. During playback, the recorded audio signal is read out by the audio head 5, amplified and demodulated through the audio signal amplifier 6 and the modulation section 7, and outputted as an audio signal.

[0007]

[Problems to be Solved by the Invention] In the conventional VISS and VASS search systems based on the CTL recording method, a search code is formed by a combination of CTL duty ratios.
It takes a relatively long time.

[0008] For this reason, in a recording method such as intermittent recording that does not perform continuous recording, the REC RE
Because of VERSE and phase matching playback, it is difficult to manage the duty ratio of the CTL signal near the continuous shot. Also, while recording the search code, there are issues such as having to remember which bit was used to record the continuous shot.
With the CTL recording method, search operations were not possible during intermittent recording.

The present invention has been made to solve the above-mentioned problems, and provides a magnetic recording/reproducing device that can perform a search operation even when recording is performed in a recording system that does not perform continuous recording, such as intermittent recording. The purpose is to

0010

[Means for Solving the Problems] In order to achieve the above object, the present invention provides a single frequency generator that can generate any frequency during intermittent recording (particularly when shooting several frames at a time); A circuit that connects a single frequency generator and a modulation section during intermittent recording, and a switch that connects an audio signal section and a modulation section during continuous recording, and detects a single frequency recorded on a magnetic tape during playback. A single frequency This signal is deep recorded instead of the audio signal, and the combination forms a search code. By reading this search code during playback, tape position information can be obtained even during intermittent recording.

[0011]

[Function] In the magnetic recording/reproducing apparatus according to the present invention, since a search code can be inserted into each frame during intermittent recording, a search operation can be easily performed during reproduction.

0012

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 shows an embodiment of the present invention, and the same reference numerals as in the conventional example shown in FIG. 5 indicate the same or corresponding parts. Reference numeral 10 indicates a circuit section that detects a single frequency recorded on the magnetic tape 9 during reproduction, and 11 indicates a frequency/voltage converter that converts the single frequency detected by the circuit section 10 into a voltage value. . Search code information is input by inputting a voltage value proportional to the frequency into the microcomputer 4.

Switch b connects the single frequency generator 12 and the modulation section during discontinuous recording such as intermittent recording, and connects the audio signal input and the modulation section at other times. 12 designates a circuit section that generates a single frequency that is used as a search code instead of an audio signal.

Next, the operation of the above configuration will be explained. When recording intermittently (interval recording), the audio signal becomes discontinuous each time it is recorded (for example, every frame).
When an audio signal is recorded and played back, the signal becomes meaningless. Therefore, a single frequency is recorded on the hi-fi track instead of an audio signal according to a command from the microcomputer 4. This recorded signal is used as a search code by changing each field using the microcomputer 4 to create a combination.

For example, from a single frequency generator, A, B
Assuming that two types of single frequencies can be generated and three frames are recorded once (one frame) by interval recording, the first of one frame as shown in the track diagram recorded on the magnetic tape shown in Figure 2. Be sure to record the field silently (blank recording), and record the frequency A or B from the next field to three frames (if there is a problem with recording accuracy, record three or more frames as blanks). When recorded as described above, the search address is a combination of the two frequencies A and B recorded in the 5th field, and 25-1=32 addresses are secured.

An example of a flowchart of microcomputer operation during recording will now be described with reference to FIG. First, interval R
Upon receiving the command for the EC operation, the microcomputer enters an interval REC indicated by reference numeral a in the flowchart, and executes a series of operations in this interval REC. Next, the microcomputer receives the command b in the flowchart and first records one field of blank information on the audio track. Then, in response to the instruction indicated by flowchart code c, a single frequency is recorded on the next audio track. flowchart code d
Upon receiving the command, the microcomputer determines whether only one recording frame of interval REC has been recorded. If one recording frame has not been recorded, the flow returns to step c and the number of recording frames is increased. Then, when the frame matches the recording frame, the next command of flowchart code e is received. Upon receiving this command, the microcomputer determines whether to continue interval REC or not, and repeats the series of operations. If the interval REC operation is not to be continued, it receives the command f in the flowchart and ends the interval REC operation.

[0017] Also, during playback, the audio head reads the signals from the magnetic tape on which the above-mentioned signals are recorded.
It demodulates with 8 and 10, detects it and extracts a single frequency. The extracted single frequency is converted into a voltage by the F/V converter 11, and the microcomputer 4 detects the single frequency recorded in the field from the voltage value. The microcomputer resets the count value by blanking and reads the subsequent signals sequentially, allowing them to be read as a search code.

FIG. 4 shows an example of a flowchart of the operation of the microcomputer during playback. First, upon receiving a command for a search operation, the microcomputer enters the search operation indicated by the flowchart numeral h, and starts monitoring the frequency of the audio track in order to execute a series of operations during the search. When there is a blank record in the audio track, the next flowchart code i is read, flowchart code j is executed, and the read counter is reset to match the search code. and,
In response to the flowchart code k, the single frequency recorded in the audio track is read, and the number of frames of the audio track read by the flowchart code l is the interval R.
It is determined whether the number of frames matches the specified number of frames for one EC. If they do not match, the flow returns to step k in the flowchart and the frame stock is increased. If the number of frames of the read audio track matches the specified number of frames, the microcomputer receives flowchart code n, fixes the read counter value, and then uses the next flowchart code o to confirm that the search code set by the user and the read counter match. Determine whether the If it is different, return to flowchart code i, read the blank record of the audio track,
Then, repeat the series of actions. If there is a match, the next flowchart code p is received, the search operation is ended,
The tape is returned to the blank recording recorded in the first field of one matched interval REC and stopped.

In the above embodiment, since one frame of intermittent recording is recorded as 3 frames, 31 different search addresses can be set. However, if one frame to be recorded is set to n frames, the search address is 22n. -1-1 addresses can be secured.

In addition, in the embodiment, a combination of single frequencies recorded in a field is used as a search code, but when used as a relative address as in the CTL recording method, the first field of one frame is used as a search code. is always recorded blank, so by reading it, it can be used as a relative address, and the number of recorded frames can also be measured.

In the embodiment, a single frequency was recorded on the high-fidelity track instead of the audio input, but if the single frequency is set to a frequency other than audible, it will be synthesized with the audio input and recorded, and during playback, It is also possible to detect only that frequency and use it as a search code in the same manner as in the embodiment.

[0022]

Effects of the Invention As explained above, according to the present invention, the search code is a combination of single frequencies recorded in the field. This has the effect that it becomes possible to record a search code on the disc, and it becomes possible to execute the search operation even during playback.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of an embodiment of the present invention.

FIG. 2 shows an example of a search code recorded on tape when the embodiment shown in FIG. 1 is executed.

FIG. 3 is a flowchart of microcomputer operations when an embodiment of the present invention is executed during recording.

FIG. 4 is a flowchart when a search operation is executed during playback according to an embodiment of the present invention.

FIG. 5 is a block diagram of a control signal and audio signal processing section of a conventional magnetic recording and reproducing device.

[Explanation of symbols]

1 Control head 2 Control signal amplifier 3 Circuit section 4 that changes the duty ratio of the CTL signal
Microcomputer 5 Audio head 6 Audio signal amplifier section 7 Modulation section 8 Demodulation section 10 Single frequency detection circuit section 11 Frequency-voltage conversion section 12 Single frequency generator

Claims (1)

[Claims] Claim 1: A single frequency generator capable of generating any frequency during intermittent recording, a single frequency generator and a modulation section connected during intermittent recording, and an audio signal section and a modulation section connected during continuous recording. a circuit section that detects a single frequency recorded on a magnetic tape during playback, a frequency/voltage converter that converts the detected signal detected by this circuit section into a voltage value, and a frequency/voltage converter that converts the detected signal detected by this circuit section into a voltage value. A magnetic recording/reproducing device comprising: a microcomputer that inputs a voltage value obtained by converting the voltage using a converter.