JPS6023764Y2 - tape recorder - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a tape recorder capable of mixing and reproducing an external microphone input signal and a reproduction signal from a reproduction head during reproduction using a simple circuit configuration.

The microphone mixing circuit in a conventional tape recorder constantly supplies power to the microphone amplifier to keep it in operation, and during playback, an external microphone input signal is supplied to the input terminal of the microphone amplifier via a playback/recording/playback selector switch. .

That is, when the recording/playback switch is switched to the playback side, the input end of the microphone amplifier is connected to the external microphone terminal, and when the switch is switched to the recording side, the input end of the microphone amplifier is separated from the external microphone terminal. It looks like this.

Further, the built-in condenser microphone has its power supply line connected to or separated from the power supply circuit by means of another recording/playback changeover switch that moves with the above-mentioned recording/playback changeover switch.

That is, when the recording/playback switch is switched to the recording side, power is supplied to the built-in condenser microphone, and when the switch is switched to the playback side, the power to the built-in condenser microphone is cut off.

In this way, conventional tape recorders have a recording/playback switch circuit that switches and connects the microphone amplifier for microphone mixing during playback, and a recording/playback switch that switches and connects the power line of the built-in condenser microphone to the power supply circuit during recording. The circuit enabled playback mixing during playback, and recording using the built-in condenser microphone during recording.

The present invention was proposed in view of this point, and uses a single recording/playback switch circuit to enable the use of a microphone amplifier during playback and the use of a built-in condenser microphone during recording. An example of the implementation circuit shown will be explained.

The figure shows the circuit configuration of a tape recorder with radio in blocks. 1 is an external microphone terminal into which the plug of an external microphone (not shown) is inserted and connected, and this terminal 1 consists of a jack switch. , one switch contact piece 1a
is always connected to the input end of the microphone amplifier 2, and the other switch contact piece 1b is connected to the signal terminal of the built-in condenser microphone 3.

The power line 4 of the built-in condenser microphone 3 is connected to the recording terminal R of the recording/playback switch 5, and the power line 6 of the microphone amplifier 2 is connected to the playback terminal P of the switch 5.
The movable contact piece of this recording/playback changeover switch 5 is connected to the power supply circuit 10B.

The input terminal of the microphone amplifier 2 is connected to the tape terminal Ta of the radio tape changeover switch 7, and
A radio tuner circuit 8 is connected to the radio terminal Ra.

Reference numeral 9 denotes a recording/reproduction amplifier, to whose input end the movable contact of a recording/reproduction changeover switch 10 is connected, and to its output end to the movable contact of a recording/reproduction changeover switch 11.

A movable contact piece of the radio tape changeover switch 7 is connected to the recording terminal R of the recording/playback changeover switch 10, and its playback terminal P is connected to one terminal of the recording/playback head 12.

Further, the recording terminal R of the recording/playback changeover switch 11 is connected to the other terminal of the recording/playback head 12.

Reference numeral 13 denotes a recording/reproducing changeover switch having a recording terminal R connected to one terminal of the recording/reproducing head 12, a reproducing terminal P connected to the other terminal of the head, and a movable contact piece being grounded.

Reference numeral 14 denotes a recording/playback changeover switch to which the playback terminals P and P of the recording/playback changeover switch 11 are connected, and the recording terminals R and R are connected. It is connected to an amplifier 16, and a speaker 17 is connected to the output of this amplifier 16.

Further, the output terminal of the microphone amplifier 2 is connected to the variable resistor 15.
, that is, the movable contact side of the recording/playback switch 14 .

In addition, the above-mentioned recording/playback selector switch 5.10, 11.13.
14 are switched in conjunction with each other.

The tape recorder of the present invention has the circuit configuration as described above, and its operation will be explained below.

First, in the operating state of the tape recorder in which the radio tape selector switch 7 is switched to the tape terminal Ta side, and during playback when the recording and playback selector switches 5, 10, 11, 13, and 14 are switched to the playback terminal P side. The microphone amplifier 2 is in an operating state with its power line 6 connected to the power supply circuit 1B through the recording/reproduction changeover switch 5.

At this time, if an external microphone is not connected to the external microphone terminal 1, the playback signal from the recording/playback head 12 is output from the speaker 17 through the recording/playback amplifier 9, the recording/playback selector switch 11.14, the variable resistor 15, and the output amplifier 16. will be played.

Furthermore, when an external microphone is connected to the external microphone terminal 1, this external microphone input signal is amplified by the microphone amplifier 2 and then sent to the recording/playback head 12 on the input side of the variable resistor 15.
The output signal is mixed with the reproduced signal from the output amplifier 17 and reproduced from the speaker 17 through the output amplifier 17.

Next, the recording/playback selector switch 5. 10. 11. 13
．． 14 is switched to the recording terminal R side during recording.

At this time, the recording/playback selector switch 5 connects the power supply circuit 10B to the power line 4 of the built-in condenser microphone 3, so the built-in condenser microphone 3 becomes operational, and the microphone amplifier 2 is disabled due to the power supply being cut off. It becomes operational.

Therefore, the input signal from the built-in condenser microphone 3 is amplified by the recording/playback amplifier 9 through the switch contact piece 1b of the external microphone terminal 1, the 1a1 radio tape selector switch 7, and the recording/playback selector switch 10, and its output is amplified by the recording/playback amplifier 9. is guided to the recording/playback head 12 through the recording/playback head 12.

In this recording state, if you connect an external microphone to the external microphone terminal 1, the circuit of the built-in condenser microphone 3 will be disconnected.
It goes without saying that an input signal from an external microphone can be guided to the recording/playback head 12.

Also, in this recording state, the radio tape selector switch 7
Needless to say, if the signal from the radio tuner circuit 8 is switched to the radio terminal Ra side, the signal from the radio tuner circuit 8 can be guided to the recording/reproducing head 12.

As mentioned above, the tape recorder of the present invention uses the recording/playback selector switch to supply power to the microphone amplifier during playback but not to the built-in condenser microphone, and the record/playback selector switch to supply power to the built-in condenser microphone during recording. However, since power is not supplied to the microphone amplifier, during playback, by connecting an external microphone to the external microphone terminal, the external microphone input signal is amplified by the microphone amplifier, and the playback signal from the recording/playback head and the playback are output. A circuit for mixing and a circuit for activating the built-in condenser microphone during recording can be selected with a single switch.

Furthermore, since the microphone amplifier is inactive during recording, there is an advantage that current consumption and noise during recording can be reduced.

[Brief explanation of drawings]

The figure is a circuit diagram of the tape recorder of the present invention. 1... External microphone terminal, 2... Microphone amplifier, 3... Built-in condenser microphone, 5, 1
0,11゜13.14... Recording/playback selector switch, 9... Recording/playback amplifier, 12...
Recording playback head.

Claims (1)

[Scope of utility model registration request] A microphone amplifier has an external microphone terminal directly connected to its input end and a speaker output circuit connected to its output end. During playback, a recording/playback head is connected to the input end, and a speaker output circuit is connected to the output end. A recording/playback amplifier to which an external microphone terminal is sometimes connected to an input end and a recording/playback head to an output end, a built-in condenser microphone to which a signal line is connected to the external microphone terminal, and a power line for the microphone amplifier. The recording and playback head is equipped with a recording and playback selector switch that selectively connects the power supply line of the built-in condenser microphone to the power supply circuit.During hip playback, power is supplied to the microphone amplifier via the recording and playback selector switch to bring it into operation. mixes and reproduces the playback signal from the built-in condenser microphone and the external microphone input signal, and when recording, supplies power to the built-in condenser microphone via the recording/playback selector switch to put it into operation and record the signal from the built-in condenser microphone or the external microphone input signal. A tape recorder characterized in that it is configured to lead to a playback head.