JPH043576B2 - - Google Patents

Description

[Detailed Description of the Invention] (a) Technical Field The present invention records index data consisting of a plurality of bits at the beginning of information recorded on a magnetic tape, and stores the index data in fast forward mode or rewind mode. The present invention relates to a tape recorder having a function of reading information and searching for information.

(b) Background of the technology Generally, when searching for information recorded on a magnetic tape, if the information is music or the like, a common method is to detect blanks between songs. but,
The music signal was getting weaker, or it was malfunctioning when it was a voice signal. Therefore, a method was developed in which index data consisting of a pulse train as shown in Figure 1 is recorded at the beginning of the information, and the index data is read in fast forward mode or rewind mode to search for information. Ta.
In the pulse train shown in Figure 1, pulse P ₁
~ _P9 is a queue signal, in which synchronization bit pulses _S1 to _S5 and data bit pulses _D1 to _D4 provided between them are provided at intervals of one pulse, and furthermore, one after the synchronization bit pulse _S5 . Queue signals P ₁₀ to _{P 18} are provided at intervals of pulse minutes. These cue signals P ₁ to _{P 9} and P ₁₀ to _{P 18} are provided to indicate index data, and in fast forward mode or rewind mode, nine consecutive pulses are displayed. By detecting whether the data has arrived, it is recognized that the data is index data. This index data may be recorded on the track on which the information is recorded, or may be recorded on a different track.

However, if the index data is provided at the beginning of the information as described above, search malfunctions will be eliminated, but in fast-forward mode, when index data is detected and playback mode is entered, the inertia of fast-forward This caused the inconvenience that the tape ran too long and the beginning of information was missing.

(C) Disclosure of the Invention The present invention has been made in view of the above-mentioned points, and when predetermined index data is detected in the fast forward mode, a coincidence signal output from the index data detection means is used to detect the winding. The return plunger drive circuit is driven to switch from the fast forward mode to the rewind mode, and the counter is made operable by the coincidence signal, and predetermined index data is read out again by rewinding, and the read pulses are transferred to the counter. A tape recorder which prevents the head of information from being lost by switching to a playback mode by an output signal of a counter which is output when a predetermined number of pulses of predetermined index data are counted by applying it to an input terminal of a counter. It provides:

(d) Embodiment FIG. 2 is a block diagram showing an embodiment of the present invention. The output of the reproduction head 1 is amplified by an amplifier circuit 2 and applied to a waveform shaping circuit 3. That is, the pulse train of the index data shown in FIG. 1 is recorded as being sinusoidally modulated, and when the reproducing head 1 reproduces the sinusoidally modulated signal, the output of the amplifier circuit 2 corresponds to the pulse. A sine wave is output, and the waveform shaping circuit 3 creates pulses corresponding to the sine wave. Therefore, when the index data is reproduced, a pulse train as shown in FIG. 1 is output from the waveform shaping circuit 3.

The index data detection circuit 4 determines whether the signal read by the reproduction head 1 is index data or not, and also determines whether pre-specified data matches the data included in the index data. This is a circuit that detects whether That is,
When nine pulses output from the waveform shaping circuit 4 arrive in succession, this signal is recognized as a queue signal, and the data bit pulses _D1 to _D4 existing between the synchronization bit pulses _S1 to _S5 are is extracted and compared with preset data, and if they match, a match signal Det is output in synchronization with the falling edge of the last pulse of the subsequent queue signal.

Switch REW closes in rewind mode,
The switch FF is a switch that is closed in the fast forward mode, and in the rewind mode, the coincidence signal Det is applied to the regeneration plunger drive circuit 5, and in the fast forward mode, the coincidence signal Det is applied to the counter 6 and the rewind plunger drive circuit 7. be done. When the playback plunger drive circuit 5 operates, the playback plunger 8 is driven to enter the playback mode, and when the rewind plunger drive circuit 7 operates, the rewind plunger 9 is driven and the rewind mode is entered.

In the fast forward mode, the counter 6 receives a coincidence signal Det applied from the index data detection circuit 4.
As a result, the reset is canceled and the circuit becomes operational, the pulse of the index data generated at the output of the waveform shaping circuit 3 applied to the input is counted, and when the count reaches a predetermined value, the signal Cout is output. The signal Cout is applied to the regeneration plunger drive circuit 5 to operate it and set it in the regeneration mode. That is, the counter 6 operates when predetermined index data is detected in the fast forward mode.
The index data is reproduced in rewind mode and the pulse train of the index data output from the waveform shaping circuit 3 is counted.
For example, output when the count reaches "23"
It outputs Cout. The count value is determined by the number of pulses of index data. That is, in the case of the pulse train shown in FIG. 1, when data bits _D1 to _D4 are all "0", the number of pulses is "23", and when data bits _D1 to _D4 are all "1", the number of pulses is "23". ”, it becomes “27”. Therefore, in this case, the count value of the counter 6 is set to "23" or less. In the case of "23", if the pulse train shown in Fig. 1 is reproduced from the direction of arrow b, the signal
The timing at which Cout is output is based on the data bits.
It depends on the number of “1” in D ₁ to _{D 4} , but the pulse
It falls within the range of P ₁ to pulse P ₅ .

In the above configuration, when searching in rewind mode, the pulse train of index data shown in FIG. 1 is reproduced from the direction of arrow b. When the index data detection circuit 4 detects a match with the specified data, the cue signal pulse P ₁
A match signal Det is output in synchronization with the falling edge of the index data, and this signal operates the regeneration plunger drive circuit 5 via the switch REW, so that the regeneration starts from before the index data. At this time,
A head of information is never lost and regenerated.

On the other hand, when searching in fast forward mode, the index data pulse train shown in FIG.
is played from the direction of When the index data detection circuit 4 detects a match with the set data, a match signal Det is output in synchronization with the falling edge of pulse _P18 of the queue signal, and this signal is sent to the The return plunger drive circuit 7 is operated and the reset of the counter 6 is released. Therefore, in this case, the tape recorder enters the rewind mode, and the detected index data is reproduced again from the direction of arrow b, and the waveform shaping circuit 3 generates a pulse train from the direction of arrow b. . This pulse train is applied to the counter 6 and counted, and when the count value of the counter 6 reaches a predetermined number, for example "23", a signal Cout is output. As described above, this timing is within the range from pulse _P1 to pulse _P5 , and the regeneration plunger drive circuit 5 is operated by the signal Cout to enter the regeneration mode. Therefore, since the index data is reproduced from the first position, there is no possibility that the beginning of the information will be omitted and reproduced.

(E) Effects As described above, according to the present invention, when predetermined data is detected from the index data in the fast forward mode, the mode is switched to the rewind mode, and the counter moves the detected index data to a predetermined value. By setting the playback mode when the number has been counted, it is possible to eliminate the inconvenience of playing back with missing information, and to obtain a tape recorder with improved operability. In particular, when applied to a tape recorder for dictation, its utility value increases.

[Brief explanation of drawings]

FIG. 1 is a pulse waveform diagram showing index data, and FIG. 2 is a block diagram showing an embodiment of the present invention. DESCRIPTION OF SYMBOLS 1... Reproduction head, 2... Amplification circuit, 3... Waveform shaping circuit, 4... Index data detection circuit, 5... Reproduction plunger drive circuit, 6... Counter, 7... Rewinding plunger drive circuit, 8...
Regeneration plunger, 9... Rewind plunger.

Claims (1)

[Claims] 1. A reproduction means for recording index data consisting of a plurality of bits at the beginning of information and reading the index data in fast forward mode or rewind mode, and a reproduction means for recording the index data consisting of a plurality of bits at the beginning of the information, and reproducing means for reading the index data in fast forward mode or rewind mode; an index data detection means for detecting a coincidence between the index data detection means; a rewinding plunger drive circuit operated by a coincidence signal outputted from the index data detection means in the fast forward mode; and counter means for counting the output of the reproduction means by a predetermined number, and when predetermined index data is detected in fast forward mode, the mode is switched to rewind mode, and the counter means counts the pulses of the index data by a predetermined number. A tape recorder characterized by switching to a playback mode depending on the output when the tape recorder is turned on.