JP2565299Y2 - Key telephone equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial application field) The present invention relates to a key telephone apparatus with an improved paging function in telephone service.

(Prior Art) A paging service is typical as a telephone service for calling absent subscribers, and a wired call and a wireless call are known for calling for calling. And in the wired system, lamps, chimes, speakers, etc.
Information is simultaneously sent to the service area to notify the called party, and the called party responds from the nearest telephone to be connected to the calling party and to be able to talk.

By the way, conventionally, a local speaker call, which is a paging function of a key telephone device, is performed using a handset of an extension telephone, and when the call is terminated, the paging function is terminated by leaving the handset on a stand or pressing a specific key. Handset was on the table.

(Problem to be Solved by the Invention) However, when the handset is left on the table as it is, there is a problem that excessive acoustic noise is transmitted from the premises speaker.

Further, when the handset is placed on the table after pressing the specific key, there is a problem that the operation is troublesome for the user.

The present invention has been made to solve such a problem, and an object thereof is to prevent noise at the end of paging from being amplified by a speaker without requiring a user to perform a special operation. It is another object of the present invention to provide a key telephone apparatus which can prevent the occurrence of a disconnection of the head of a voice signal.

(Means for Solving the Problems) In order to achieve the above object, the present invention relates to a button telephone apparatus for outputting a voice signal from a transmitter via a communication path switch from a premises speaker. And a delay circuit for delaying an output signal from the comparison circuit, when the audio signal to the comparison circuit is lower than the reference level for a predetermined time or more. The signal output from the delay circuit is stopped after a predetermined time elapses, so that the communication path is opened and the audio output from the local speaker is set to a fixed time, and the audio signal from the transmitter is output. A key telephone device for outputting voice from a local speaker via a communication path switch, comprising: a comparison circuit for comparing a voice signal from the transmitter with a reference level; A delay circuit for delaying an output signal from the path, a flip-flop circuit for outputting a control signal for controlling the opening and closing of the communication path switch, and a reset for the output of the delay circuit, and an output of the flip-flop circuit and an output of the delay circuit. OR circuit to be input,
The rising edge of the audio signal from when the communication path switch is closed to when the delay circuit is activated is formed as a passage path by the output of the OR circuit based on the output of the flip-flop circuit, and the audio signal is output to the local speaker. It is characterized in that the occurrence of cutting is prevented.

(Operation) According to the present invention, the audio signal from the transmitter is input to the comparison circuit. When a normal voice, that is, a voice signal higher than the reference level is input, a signal is output from the delay circuit after a rise delay due to the output of the comparison circuit. A passage path is formed by the output from the delay circuit, and a call can be made from the premises speaker.

When the audio signal below the reference level, that is, the audio signal from the transmitter is interrupted, the output from the comparison circuit becomes low. The output from the delay circuit becomes low level after falling off the audio signal, that is, after a predetermined time, that is, after the interruption of the audio signal. When the output from the delay circuit becomes low level, the communication path is opened and the voice signal to the local speaker is cut off. Therefore, if the handset is returned to the cradle a predetermined time after the end of the paging, the communication path is already opened, and there is an advantage that the noise at this time is not likely to be amplified by the local speaker.

Also, a control signal for controlling the opening and closing of the communication path switch is input to an FF circuit (flip-flop circuit),
The communication path is formed by the logical sum of the output of the circuit and the output of the delay circuit. Accordingly, the occurrence of the beginning of a speech signal is prevented. Further, since the FF circuit is reset by the output of the delay circuit, if an audio signal having a level equal to or lower than the reference level continues for a predetermined time or more, noise after the completion of paging is eliminated as described above.

Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings.

FIG. 1 shows a schematic circuit configuration of the key telephone apparatus according to the present invention.

In FIG. 1, an audio signal input from a transmitter of the extension telephone 1 is amplified by an amplifier 4 via a communication path switch 2 and a relay contact 3a, and output from a local speaker 5.

Here, in the present invention, there is provided a comparison circuit for comparing the audio signal from the transmitter with a reference level, and a delay circuit for delaying an output signal from the comparison circuit, wherein the audio signal to the comparison circuit is a predetermined signal. When the voltage becomes lower than the reference level for more than a time, the output from the delay circuit becomes low after a fall delay (predetermined time), and the sound output from the in-house speaker 5 is stopped.

In this embodiment, the output from the communication path switch 2 is sent out to the relay contact 3a and is input to the comparison circuit 7 via the rectifier 6, where the reference voltage generation circuit 9
Is compared to the output of The comparison circuit 7 outputs a signal to the delay circuit 8 while the output from the rectifier 6 is higher than the reference voltage. The delay circuit 8 outputs a signal after a rise delay. This output signal is input to the base of the transistor 10, turns on the transistor 10, turns on the relay 3, closes the relay contact 3a, and outputs the voice signal from the extension telephone 1 from the local speaker 5.

FIG. 2 (a) shows the internal configuration of the delay circuit 8, in which three resistors R ₁ , R ₂ , R ₃ , a capacitor C and AN
D circuit is fitted. FIG. 2 (b) shows the signal waveform at each point. The waveform at point A is the input signal, that is, the output waveform from the comparison circuit 7, and the waveform at point B is the output waveform after integration by CR. The waveform at point C is the output waveform of the AND circuit. As is apparent from the waveform of the point C, the rise time of the input signal delayed by t _1, and the fall time t ₂ only seen delaying.

Next, the control operation of this embodiment will be described with reference to FIG.

A certain level or more audio signals v through the rectifier 6 is inputted to the comparison circuit 7, the output signal a from the delay circuit 8 after a certain delay time t ₁ is output, so that the relay 3 is energized state. When the relay 3 is energized, the relay contact 3a is closed and the audio signal s is amplified from the premises speaker 5. At this time, if not inputted to the comparison circuit 7 continue a certain level or more audio signals, the output of the delay circuit 3 becomes low level after the delay time t _2, the relay contacts 3 are opened is cut off energization of the relay 3 , The input to the premises speaker 5 is cut off.

Also in the cradle the handset in this state, the instantaneous noise as shown in the speech signal v at this time, even as the delay circuit 8 has climbed standing after a delay time t ₁ trying operation, relay 3 Since the noise has already been eliminated before the operation is attempted, the noise is not amplified by the indoor speaker 5.

In this embodiment, t ₁ is approximately equal to the delay time.
500msec, it was approximately 2sec t _2.

Next, FIG. 4 shows another embodiment of the key telephone apparatus according to the present invention.

In the present invention, a comparison circuit for comparing an audio signal from the transmitter with a reference level, and a delay circuit for delaying an output signal from the comparison circuit, and a control signal for opening and closing the speech path switch, An audio signal is output to the indoor speaker by a logical sum signal with an output signal from the delay circuit.

In the present embodiment, an FF circuit based on an output signal b from the delay circuit 8 and a control signal d for controlling opening and closing of the output to the amplifier 4 of the communication path switch 2 until the delay circuit 8 outputs a signal. This embodiment differs from the above-described embodiment in that an audio signal is output to the indoor speaker 5 by the logical sum signal a with the output signal c of FIG. 1, and therefore, the same or corresponding parts as in FIG. The description is omitted.

In FIG. 4, a control signal d for controlling opening and closing of the output of the communication path switch 2 to the amplifier 4 is input to a clock terminal C of a D-type FF circuit (flip-flop circuit) 11, and its Q output is ORed. The signal is input to one terminal of the circuit 12. The output of the delay circuit 8 is input to the other terminal of the OR circuit 12, and is connected to the reset terminal R of the FF circuit 11. Then, the output of the OR circuit 12 is input to the base of the transistor 10, and the conduction of the relay 3 is controlled.

FIG. 5 shows the operation timing according to this embodiment.

The control signal d becomes high level, and the FF circuit 11
Becomes high, the output signal a of the OR circuit 12 becomes high. As a result, the relay 3 is energized, the relay contact 3a is closed, and the premises speaker 5 outputs the audio signal s.

On the other hand, the audio signal v is input to the delay circuit 8 via the rectifier 6 and the comparison circuit 7, the output becomes high level after a lapse of the delay time t _1, to reset the FF circuit 11 at the rising edge at this time. However, while the audio signal v is input at a certain level or higher, the output of the delay circuit 8 is maintained at a high level, and the output signal a of the OR circuit 12 is also maintained at a high level. 3 continues to be energized. A certain level or more audio signal v is not input, the output of the delay circuit 8 becomes low level after the delay time t _2.

Also, in this state, even in the handset, the instantaneous noise as shown in the voice signal v at this time is eliminated before the relay 3 tries to operate for the same reason as described above. Therefore, there is no possibility that the sound is loudspeaked by the local speaker 5.

Moreover, according to the present embodiment, the communication path between the extension telephone 1 and the local loudspeaker 5 is closed simultaneously with the rise of the control signal d of the communication path switch 2, so that there is no possibility that the head of the conversation will be disconnected.

(Effects of the Invention) As described above, the invention includes a comparison circuit that compares an audio signal from a transmitter with a reference level, and a delay circuit that delays an output signal from the comparison circuit. When the audio signal of the delay circuit becomes lower than the reference level for a predetermined time or more, the signal output from the delay circuit is stopped after a predetermined time has elapsed, thereby opening the communication path and stopping the audio output by the local speaker. By doing so, it is possible to prevent the noise at the end of paging from being amplified by the speaker without requiring the user to perform any special operation.

A comparison circuit that compares the audio signal from the transmitter with a reference level; a delay circuit that delays an output signal from the comparison circuit; and a control signal that controls opening and closing of a communication path switch. A flip-flop circuit that is reset by an output, and an OR circuit that receives an output of the flip-flop circuit and an output of the delay circuit as inputs,
The rising edge of the audio signal from when the communication path switch is closed to when the delay circuit is activated is formed as a passage path by the output of the OR circuit based on the output of the flip-flop circuit, and the audio signal is output to the local speaker. By preventing the occurrence of disconnection, in addition to the above, it is possible to prevent the occurrence of disconnection of the beginning of a speech signal.

[Brief description of the drawings]

1 and 4 are diagrams showing a schematic circuit configuration of the key telephone apparatus according to the present invention, FIG. 2 (a) is a diagram showing an internal configuration of the delay circuit, and FIG. 2 (b) is each point thereof. FIGS. 3 and 5 are diagrams showing operation timings in the present embodiment. DESCRIPTION OF SYMBOLS 1 ... Extension telephone 2 ... Talking path switch 3 ... Relay 3a ... Relay contact 5 ... Premise speaker 7 ... Comparison circuit 8 ... Delay circuit 9 ... Reference voltage generation circuit 11 ... FF circuit 12 ... Or circuit

Claims (2)

(57) [Scope of request for utility model registration] 1. A key telephone device for outputting a voice signal from a transmitter via a communication path switch from a local loudspeaker, comprising: a comparison circuit for comparing the voice signal from the transmitter with a reference level; A delay circuit for delaying an output signal from the circuit, wherein when the audio signal to the comparison circuit has become lower than a reference level for a predetermined time or more, the signal output from the delay circuit stops after a predetermined time has elapsed. A button path telephone device for opening a passage path to stop sound output from the in-house speaker. 2. A key telephone apparatus for outputting a voice signal from a transmitter via a communication path switch from a local speaker, comprising: a comparison circuit for comparing the voice signal from the transmitter with a reference level; A delay circuit that delays an output signal from the circuit; a flip-flop circuit that outputs a control signal that controls the opening and closing of the communication path switch and that is reset by an output of the delay circuit; and an output of the flip-flop circuit and an output of the delay circuit. An OR circuit as an input, wherein a rising path of an audio signal from when the communication path switch is closed to when the delay circuit is activated is formed as a path by the output of the OR circuit by the output of the flip-flop circuit to form a path to the local speaker. A key telephone device for outputting a voice signal to prevent occurrence of a disconnection of a head of a conversation.