JPS6284459A - Tape recorder with intermusic space detection function - Google Patents

Abstract

PURPOSE:To eliminate an action mistakingly executing intermusic space detection by providing an inhibiting means inhibiting the intermusic space detection during the prescribed period after a play action command is issued. CONSTITUTION:When the play action command is issued to rise a power source plus B, the control input of a muting circuit 4 keeps a high level with a muting switch SW1 at an on state until a tape drive mechanism 1 comes to a play action state. On the other hand, a potential at a serial connection point A be tween a capacitor C and a resistance R2 slowly drops according to a time constant decided by the capacitor C and the resistance R2, while the base of a transistor Q2 becomes a high level by a time corresponding to the dropping time. Then the transistor Q2 is turned on. When the capacitor C and the resis tance R2 are set so that the transistor Q2 can be turned on in that time, an MS switch SW2 is turned on in said time, and no intermusic detection is made even if a power source is supplied to an intermusic space detecting circuit 5.

Description

DETAILED DESCRIPTION OF THE INVENTION Flame 111 The present invention relates to a tape recorder, and more particularly to a tape recorder having a so-called song interval detection function for detecting unrecorded portions between songs on a magnetic tape.

BACKGROUND TECHNOLOGY The song interval detection function uses music search operations, i.e., fast-forwarding or rewinding the tape, to drive the tape to the unrecorded part between songs and play the next song after the song that was being played or the song that was being played. This function is necessary for controlling operations such as playing back from the beginning of a song.

A conventional tape recorder having such a function is shown in FIG. In FIG. 3, a reproduced signal output from a head 2 incorporated in a tape transport mechanism 1 is frequency compensated by an equalizer amplifier 3 and then supplied to a muting circuit 4 and a song interval detection circuit 5. The song interval detection circuit 5 is configured to output a positive pulse as an inter-music detection signal when the signal level of the reproduced signal falls below a predetermined level. The power supply terminal of this inter-track detection circuit 5 is connected to a muting switch SW provided in the tape transport mechanism section 1.
+ and MS (music search command) switch S
Power element B is supplied via W2.

The muting switch S W + is formed to be in an on state when the tape transport mechanism 1 is not in a play operation state. Furthermore, the MS switch SW2 is configured to be turned on by a user's operation of an operation section (not shown).

Muting circuit 4 includes a muting switch S
The power supply element B that has passed only W+ is supplied as a control input, and the muting circuit 4 is configured to attenuate the reproduced signal when the control input becomes high level. The reproduction signal that has passed through the muting circuit 4 has its signal level adjusted by the volume VR, and then passes through the power amplifier 6 and becomes a drive signal for the speaker 7.

On the other hand, the output of the song interval detection circuit 5 is transmitted via the resistor Rbi to the transistor Q! supplied to the base of The emitter of transistor Q2 is grounded. This transistor Q1'
A plunger 8 is connected between the recorder and the power source +8 to release the tape transport mechanism 1 from the fast forward operating state or the rewind operating state and bring it into the play operating state.

The power supply +B is activated in response to a play operation command issued from a control section (not shown) by the user's operation of the control section (not shown) or by loading a cassette tape. . Further, the tape transport mechanism section 1 is configured to be in a state according to various commands issued from a control section (not shown).

In the above configuration, when the play operation command is issued and the power supply B is turned on, the muting switch S W + remains on until the tape transport mechanism section 1 enters the play operation state. The power source B is instantaneously supplied to the circuit 4 as a control input, and the damping effect of the muting circuit 4 is activated to prevent unpleasant sounds such as pop noises from occurring. When the tape transport mechanism 1 enters the play operation state,
Muting switch SW1 is turned off and power supply B
is no longer supplied to the muting circuit 4 as a control input, the damping effect of the muting circuit 4 ceases to work, and reproduction of the song is started.

At this time, when the tape transport mechanism section 1 enters the fast forward or rewind operation state after the MS switch SW2 is turned on by the user's operation of the operation section (not shown), the tape fast forward or rewind operation is performed. Prior to the start, the muting switch SW1 is turned on and the power source B is supplied to the song interval detection circuit 5. At the same time, the power source B is supplied to the muting circuit 4 as a control input to attenuate the reproduction signal, and the reproduction of the song is stopped. after that,
When the unrecorded portion between songs reaches the abutment position of the head 2 due to fast forwarding or rewinding of the tape and the signal level of the playback signal becomes below a predetermined level, a positive pulse is output from the song interval detection circuit 5 as an inter song detection signal. is output as Then, the transistor Q1 is turned on, the plunger 8 is driven, and the tape transport mechanism section 1 is put into the play operation state again. As a result, the muting switch SWI is turned off again, the damping effect of the muting circuit 4 no longer works, and playback of the next song after the song that was being played or playback from the beginning of the song that was being played starts. Ru.

In the conventional tape recorder as described above, the muting switch SW is used from when the play operation command is issued until the tape transport mechanism 1 enters the play operation state.
+ is in the on state, so if the MS switch SW2 is in the on state at this time, power is supplied to the song interval detection circuit 5. Therefore, if the output of the head 2 changes in the same way as when the unrecorded part between songs reaches the contact position of the head 2 before the tape transport mechanism 1 enters the play operation state, The inter-song signal is erroneously output from the detection circuit 5, and the plunger 8 is erroneously driven. Therefore, in a conventional tape recorder, if the tape transport mechanism 1 has an auto-reverse function and the plunger 8 is shared for canceling fast forwarding and rewinding and changing the tape running direction, immediately after the play operation starts. However, there was a problem in that malfunctions occurred in which the tape running direction erroneously changed.

SUMMARY OF THE INVENTION An object of the present invention is to provide a tape recorder with a song interval detection function that does not perform an erroneous song interval detection operation.

The tape recorder with a song interval detection function according to the present invention is provided with a prohibition means for prohibiting the song interval detection operation for a predetermined period of time after the 6-play operation command is issued.

Embodiments Hereinafter, embodiments of the present invention will be described in detail with reference to FIGS. 1 and 2.

In FIG. 1, head 2. Equalizer amplifier 3, muting circuit 42, inter-song detection circuit 5. power amplifier 6,
Speaker 7, plunger 8. Transistor Q+, resistor R
+, muting switch S W + and MS switch S W 2 are connected in the same way as in the device of FIG.

However, in this example, the power source B is also supplied to the inter-track detection prohibition circuit 10. In the song interval detection prohibition circuit 10, a power supply element B is applied to a differentiating circuit comprising a capacitor C and a resistor R2 connected in series between the input terminal and ground.

The differential signal derived at the series connection point A of the capacitor C and the resistor R2 is applied to the base of the transistor Q2 via the resistor R3. The emitter of transistor Q2 is grounded. The collector of this transistor Q2 is connected to the input terminal of the song interval detection circuit 5. Note that seven nodes of diodes D are connected to the series connection point A. The cathode of diode D is grounded.

In the above configuration, when a play operation command is issued at time t1 and the power supply B is turned on as shown in FIG. Since the muting circuit 4 remains on, the control input to the muting circuit 4 remains at a high level from time t1 to time t2 when the tape transport mechanism 1 enters the play operation state, as shown in FIG. 4(B).

On the other hand, the potential at the series connection point A of the capacitor C and the resistor R2 becomes equal to the potential of the power supply element B almost instantaneously at time t1, as shown in FIG. gradually decreases.

Then, the base of the transistor Q2 becomes high level for a period of time corresponding to the time constant determined by the capacitor C and the resistor R2 from time t1, and the transistor Q2 is turned on. As a result, the input terminal of the song interval detection circuit 5 is grounded and no reproduction signal is input. Therefore, from time t1 to 1
If the values of the capacitor C and the resistor R2 are set so that the transistor Q2 is on for 2 hours, from time t1 to t
Even if the MS switch S W 2 is turned on and power is supplied to the song interval detection circuit 5 within the time period of 2, the song interval detection is not performed, and malfunctions due to erroneous generation of the song interval detection signal are prevented. Ru.

In addition, since the charge in the capacitor C is almost instantaneously discharged by the diode D in the inter-song detection prohibition circuit 10 immediately after the power supply element B falls, the play operation command and the stop command are issued alternately and repeatedly in a short period of time. Even in such a case, the potential at the series connection point A reliably rises when the power supply element B rises, and the inter-track detection operation is reliably inhibited.

Further, in the above embodiment, the collector of the transistor Q2 is connected to the input terminal of the song interval detection circuit 5, but the song interval detection circuit 5 is provided with a mute terminal, and by grounding this mute terminal, the collector of the transistor Q2 is connected to the input terminal of the song interval detection circuit 5. If generation of the detection signal is prohibited, the collector of the transistor Q2 may be connected to this mute terminal. Furthermore, the same effect will also work if the collector of the transistor Q2 is connected to the output terminal of the song interval detection circuit 5.

Effects of the Invention As detailed above, the tape recorder with a song interval detection function according to the present invention is configured to include a prohibition means for prohibiting the song interval detection operation for a predetermined period of time after a play operation command is issued. Therefore, the erroneous song interval detection operation is not performed between the time when the play operation command is issued and the time when the tape transport mechanism section enters the play operation state, thereby preventing the occurrence of malfunctions such as an erroneous switching operation of the tape running direction. This means that you can do it.

[Brief explanation of drawings]

FIG. 1 is a circuit block diagram showing an embodiment of the present invention, FIG. 2 is a waveform diagram showing the operation of the device shown in FIG. 1, and FIG.
FIG. 1 is a circuit block diagram showing a conventional tape recorder. =10- Explanation of symbols of main parts 5...Song interval detection circuit

Claims (1)

[Claims] Includes a song interval detection means for generating a song interval detection signal when the signal level of the playback signal falls below a predetermined level while the tape transport mechanism is not in a play operation state and a music search command is issued. , a tape recorder configured to perform a song interval detection operation that changes the state of the tape transport mechanism in response to the song interval detection signal, wherein the song interval detection operation is performed for a predetermined period of time after a play operation command is issued. A tape recorder with a song interval detection function, characterized in that it is equipped with a prohibition means for prohibiting.