JPH0614094A - Key telephone set - Google Patents

Abstract

PURPOSE:To prevent production of unpleasant noise in a dial pulse signal at the time of transmission of an interruption signal by providing a dial pulse signal generating section and a stabilizing interruption signal transmission section to the telephone set. CONSTITUTION:A inverse transformation element of an AND circuit 31 is connected to an output terminal of a D-FF 14f of a counter signal generating section 21, other element of the circuit 31 is connected to each output terminal of D-FF14g, 14h and an interruption control signal is sent in a stable state after the lapse of a prescribed time from the output of a dial pulse signal P from a CPU 12. An output terminal of the circuit 31 connects to a D terminal of a D-FF30 and an interruption signal is fed to the CPU 2. The dial pulse signal is fed to one terminal of the circuit 13 fro the CPU 12 and an output of a dial pulse signal generating section 20 from the output terminal of the D-FF15 is fed to the other terminal of the circuit 13 and a rectangular dial pulse signal is generated at an output terminal of the circuit 13.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a button telephone,
In particular, the present invention relates to a key telephone set which sends an interrupt signal when a dial pulse signal is stabilized.

[0002]

2. Description of the Related Art Generally, a key telephone has a dial pulse signal generator 10 and a counter signal generator 11 as shown in FIG. The dial pulse signal generator 10 is provided with a CPU 12 that generates a dial pulse signal and the like, and this is connected to one terminal of an AND circuit 13.

The counter signal generator 11 includes a D. F. F1
4a, 14b ... 14h are connected in cascade, 2,560 Hz
The pulse signal of D. F. 10 for F14h
A count pulse signal of Hz signal is obtained. D. F. D.F is connected to the output terminal of F14h. F. The clock terminal of F15 is connected to control the dial pulse signal P and the interrupt signal So.

The counter signal generator 11 is provided with an inverter 16 for converting a pulse signal of 2,560 Hz into an inverse pulse signal and converting the pulse signal into a D.D. F. It is adapted to be input to the clock terminal of F17.

D. F. F14a, 14b, 14c, 14
The output terminal of d is provided with an AND terminal that alternately performs inverse conversion
Circuit 18 also includes D.I. F. F14e, 14f, 14
An AND circuit 19 having terminals for alternately performing inverse conversion is connected to the output terminals of g and 14h, and these output terminals are AN
It is adapted to be connected to the input terminal of the D circuit 20.
The output terminal of the AND circuit 20 has a D.D. F. The D terminal of F17 is connected and the control count signal is obtained.

D. F. The output terminal of the F17 is connected to the D. F. The S15 terminal of F15 is connected to obtain control signals of the dial pulse signal P and the interrupt signal So.

D. F. The output terminal of F15 is CPU12
And the other terminal of the AND circuit 13
To the dial pulse signal P, and the AND circuit 13 controls the dial pulse signal P. Generation control of the dial pulse signal of the key telephone having the above configuration will be described.

First, when a dial key (not shown) of the dial pulse signal generator 10 is pressed as 2, for example, the CPU 12 sends a dial pulse signal of 2 to one terminal of the AND circuit 13.

Further, under the control of the counter signal and the like by the counter signal generator 11, the D.D. F. The control signal of the dial pulse signal P and the interrupt signal So are generated from the output terminal of F15. The control signal of the dial pulse signal P and the interrupt signal So are sent to the other terminals of the CPU 12 and the AND circuit 13.

As a result, the rectangular wave signal P of the dial pulse signal 2 as shown in FIG. 5 or 6 is generated from the output terminal of the AND circuit 13.

An interrupt signal So is sent to the head or tail of the dial pulse signal P via the CPU 12 to forcibly stop the dial pulse signal P.

By the way, a square wave dial pulse signal P
There is usually a voltage fluctuation in the head or tail of the. When the interrupt signal So is sent to the head or tail of the varying dial pulse signal P, the voltage variation increases more and more, causing an unpleasant noise via a handset (not shown) or the like.

In order to prevent this unpleasant noise, muting is performed during transmission of the dial signal. However, even if this method is performed, there is a problem in that the voltage fluctuation remains in the dial pulse signal P when the interrupt signal So ends and the unpleasant sound cannot be removed.

Therefore, a method has been adopted in which the transmission of the interrupt signal So is stopped and a program for ending the dial pulse signal P of the dial pulse signal P is incorporated.

However, when this program is adopted, unpleasant noise is removed, but there is a problem that the program becomes long and the signal processing cannot catch up.

Therefore, the present invention provides a key telephone which does not generate unpleasant noise even if an interrupt signal is sent to a dial pulse signal.

[0017]

DISCLOSURE OF THE INVENTION According to the present invention, a dial pulse signal generator and an interrupt signal are sent at the time of stabilization after a predetermined time has elapsed from the rising or falling of the dial pulse signal generated from the dial pulse signal generator. And a stabilized interrupt signal transmitting section for providing a key telephone.

[0018]

Operation: The dial key of the button telephone is operated to generate a desired dial pulse signal. An interrupt signal is sent when the dial pulse signal stabilizes after a predetermined time has elapsed from the rising or falling portion of the dial pulse signal, and the dial pulse signal is forcibly terminated.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the key telephone according to the present invention will be described below with reference to FIGS. 1, 2 and 3.

FIG. 1 shows a dial pulse signal generator 20 and a counter signal generator 21 of the key telephone of the present invention. The basic configuration of the dial pulse signal generator 20 and the counter signal generator 21 is almost the same as that of the dial pulse signal generator 10 and the counter signal generator 11 shown in FIG. However, the detailed description will be omitted.

A CPU 12 for generating a dial signal and the like is connected to the dial pulse signal generator 20 at one terminal of an AND circuit 13.

The output terminal of the counter signal generator 21 is D.
F. It is connected to the clock terminal of F15 and controls the dial pulse signal P. The output terminal of the inverter 16 is D.V. F. F17 and D.I. F. Each of them is connected to a clock terminal of F30 to form a count pulse control signal.

The output terminals of the AND circuits 18 and 19 are connected to the input terminals of the AND circuit 20.
This output terminal is F. F17, through the inverter 21 D. F. F15 is connected to control the dial pulse signal P from the CPU 12.

Further, the D.D. F.
The output terminal of F14f is connected to the inverse conversion element of the AND circuit 31, D. F. F14g and D.I. F. Each output terminal of F14h is connected to another element of the AND circuit 31 and sends an interrupt control signal at the time of stabilization after a predetermined time has elapsed from the dial pulse signal P. The output terminal of the AND circuit 31 has a D.D. F. It is connected to the D terminal of F30 and sends an interrupt signal So to the CPU 12.

In the key telephone having such a configuration, the CPU 12 sends the dial pulse signal P to one terminal of the AND circuit 13, and the dial pulse signal P. F. A dial pulse control signal is sent from the output terminal of F15 to the other terminal of the AND circuit 13, and a rectangular wave dial pulse signal P as shown in FIG. 5 or 6 is generated from the output terminal of the AND circuit 13.

An interrupt signal So is sent to the dial pulse signal P at the time of stabilization through the CPU 12 so as to forcibly stop the interrupt signal So and perform the end control.

Other dial pulse signals P of 0, 1, 7, etc.
The same applies when an interrupt signal is sent to the.

In the key telephone of the present invention, the counter circuit is provided with the sending section for the interrupt signal So.
It goes without saying that a transmission section for the interrupt signal So may be provided inside the.

[0029]

The key telephone of the present invention sends an interrupt signal at the time of stabilization after a lapse of a predetermined time from the rising or falling of the dial pulse signal generator and the dial pulse signal generated from the dial pulse signal generator. Since the stabilized interrupt signal transmitting unit is provided, even if the interrupt signal is interrupted by the dial pulse signal, the voltage fluctuation does not increase and a stable call or the like can be performed.

[Brief description of drawings]

FIG. 1 is a block diagram showing an outline of a key telephone.

FIG. 2 is a waveform chart for explaining the operation of FIG.

FIG. 3 is a waveform diagram for explaining the operation of FIG.

FIG. 4 is a block diagram showing an outline of a conventional key telephone.

FIG. 5 is a waveform diagram for explaining the operation of FIG.

6 is a waveform chart for explaining the operation of FIG.

[Explanation of symbols]

 10 dial pulse signal generator 11 counter signal generator 12 CPU 13 AND circuit 14a, 14b ... F. F 15, 17 D. F. F 30 D. F. F 31 AND circuit

Claims (1)

[Claims] 1. A dial pulse signal generating section, and a stabilizing interrupt signal transmitting section for transmitting an interrupt signal at the time of stabilization after a predetermined time has elapsed from the rise or fall of the dial pulse signal generated from the dial pulse signal generating section. A button telephone, which is provided with.