JP2874116B2 - Key press invalidation method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Summary] The present invention relates to a key press invalidation method for a telephone which inputs a destination telephone number by a key matrix and sends a dial pulse to an exchange. In a telephone, a key matrix circuit having a dial key and a dial transmission for detecting a press of the dial key and transmitting a dial signal corresponding to the pressed dial key are provided. Means, a hold circuit for detecting press of a hold key and holding a call, and a key press invalidation circuit for invalidating detection of press of a key of the dial sending means while the hold circuit is operating. Constitute.

[Industrial applications]

The present invention relates to a telephone, and more particularly, to a key depression invalidation method for a telephone which inputs a destination telephone number by a key matrix and sends a dial pulse to an exchange.

[Conventional technology]

2. Description of the Related Art In recent years, with the development of IC technology, many telephones have been provided with keys 0-9, #, and * on a telephone and transmit dial pulses or push-button dial signals by pressing the keys.

These telephones generally use a dialer IC. FIG. 9 is a configuration diagram of the dialer IC. The key matrix is composed of a total of 3 × 4 keys arranged at respective intersections of (0-9, *, #), Col side (Col1 to Col4) and Row side (Row1 to Row3). And a detection terminal connected to the terminal on the row side. The key control logic 11 is connected to these detection terminals by the SEPP composed of the buffers B12 to B42 and the FETs F11 to F42 (when the gate is connected to the output of the buffer and the buffer outputs a high level, the high-level FET is turned on. A high-level buffer is provided on the column side, and a low-level FET is turned on and a low level is output to the column side when it is at the low level. this
The FETs F11, F12, ... constituting the SEPP function as current sources even when they are connected to the high-level side and low-level side, respectively.By pressing the switch, it is possible to determine which column and row are connected. Each buffer B12
B42 detects and adds to the key control logic, and the key control logit detects which switch has been pressed.

In summary, the column terminal and the low terminal of the dialer IC 10 are sequentially input terminals, external keys are scanned by the key control logic 11, and key data is given to the output logic unit 12 when the key is depressed. In the dial pulse (DP) mode, a dial pulse is transmitted from the DP terminal. In the DTMF mode, the DTMF generator is controlled and a DTMF signal is transmitted from the tone-out terminal. For example, when the key B is pressed, both the key control logics i1 and ia are fixed at L level, and the other inputs become scan output signals. Although the above-mentioned control logics i1 and ia are both at the L level, they may be at the H level depending on the power supply levels of the FETs 11 to 41 and FETs 12 to F42. In this state, the column and row inputs are fixed at one level, for example, L level is fixed, the key data becomes valid, the code corresponding to the key is input to the output logic 12, and the output logic 12 outputs the dial pulse. Also DTMF generator
13 outputs a dial tone (DTMF signal). By the above-described operation, the mutual number can be input from the dial key even in the conventional dial-type line, and the dial need not be turned as in the past.

[Problems to be solved by the invention]

In the above-mentioned conventional telephone, a pressed key is detected by a key matrix, and a dial pulse or dial tone corresponding to the detected key is transmitted.

In addition, conventionally, a hold circuit is provided for calling a target party to a telephone at the time of an incoming call or the like. The hold circuit is provided with a key (hold key) other than the key matrix described above, and when the hold key is pressed, the handset of the telephone does not operate and the melody is transmitted from a built-in melody IC for holding, for example. It is like that.

In a telephone having the above-mentioned dialer IC and further having a hold mechanism, the dialer IC and the hold control circuit operate independently of each other. This causes a problem that the call cannot be communicated with the other party on hold. For example, if the dial key is erroneously depressed during the hold, a dial pulse is sent out, and the exchange may erroneously determine that the dial pulse is the opening of the DC circuit and terminate the line.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a key press invalidation method for preventing an erroneous operation even when a telephone is in a hold state by an erroneous key operation.

[Means for solving the problem]

 FIG. 1 is a block diagram showing the principle of the present invention.

 The present invention relates to a telephone.

The key matrix circuit 1 has dial keys, for example, a 3 × 4 matrix is formed by a total of 12 keys of 0 to 9, #, and *.

The dial sending circuit 2 detects pressing of the keys constituting the key matrix circuit 1, and sends out dial keys corresponding to the pressed keys.

The hold circuit 3 detects that a hold key not included in the key matrix circuit 1 is pressed, and holds the call.

The key press invalidation circuit 4 invalidates the key press detection of the dial sending circuit 2 while the hold circuit 3 is operating.

The speech circuit 5 sends out a hold melody generated when the hold circuit 3 performs a hold operation to the line.

[Action]

During normal operation, the dial sending circuit 2 detects that a key constituting the key matrix circuit 1 has been pressed, and sends, for example, a dial pulse signal to the line. When the user puts the call on hold for some reason during a call, the hold circuit 3 operates and the key press invalidation circuit operates. For example, at least two of the lines constituting the matrix of the key matrix circuit 1 are connected to ground or the like. The detection operation of the dial sending circuit 2 is regarded as a malfunction. The dial transmission circuit 2 due to this malfunction does not transmit the dial pulse signal because the key operation is invalid.

At this time, the hold circuit 3 sends out the melody to the line via the communication circuit 5.

〔Example〕

 Hereinafter, the present invention will be described in detail with reference to the drawings.

FIG. 2 is a system configuration diagram of an embodiment of the present invention. A telephone set 22 is connected to the exchange 21 via telephone lines l1 and l2. The telephone line l1 is connected to the dialer IC2 via the contact S of the relay LX.
3. Connected to the call path IC24. The telephone line l2 is connected to a dialer IC23 and a communication path IC24. One end of the dialer IC23 is connected to the other end of the coil of the relay LX whose one end is grounded, and a push-button dial signal output terminal of the dialer IC23 is added to the communication path IC24. A key matrix 26 is connected to the dialer IC 23, and a hold circuit 25 is connected to a line connecting the dialer IC 23 and the key matrix 26 (a part of the matrix line).
When 27 is pressed, the switches are switched as if a plurality of keys of the key matrix 26 were pressed. Also hold circuit at the same time
When the switch 27 included in 25 is pressed, a melody for holding is output to the communication path IC 24. The communication path IC 24 is connected to a handset 28.

When the person operating the telephone set 22 wishes to make a call, the handset 28 is lifted off-hook, and the key matrix 26 is operated to input the number of the party to be called.
The dialer IC23 detects this key input and operates a relay to generate a dial pulse corresponding to the number,
The contact S is turned off by the number of times corresponding to the dial number, and a dial pulse is generated. The contact S is a break contact, and is turned off when the coil LX of the relay is driven by the dialer IC23.

When the other party (not shown) answers the telephone via the exchange after dialing is completed, the exchange 21 inverts the voltages applied to the lines l1 and l2 and reports to the telephone 22 that the line has been connected. In the embodiment of the present invention, a circuit for judging whether or not the other party is connected is not provided, and when the connection is made, a call is made by the handset 28 via the communication path IC 24.

When the line is connected by the above-described operation and held for some reason, the user depresses the switch 27 connected to the holding circuit 25 to put it on hold. By detecting ON / OFF of the switch 27, the hold circuit 25 determines that the hold is on hold, and grounds a part of the key matrix 26. That is, two of the plurality of matrix lines are grounded. With this, dialer IC
23 judges that an erroneous operation has been performed, does not generate a dial pulse, and ignores a signal applied from the key matrix.

The hold circuit 25 outputs a melody to the communication path IC 24.
As a result, a melody signal flows through the lines l1 and l2, and the melody on hold is transmitted to the other party's telephone.

The dialer IC 23 constantly scans the key matrix 26 to determine whether the switch has been pressed, but when the hold circuit 25 puts the switch on hold, the dialer IC 23 inputs as if the multiple keys of the key matrix 26 were pressed simultaneously. I c
23 always determines that the input for the key input is invalid and does not operate at all. By not operating, even if the user presses the switch by mistake, the dial pulse is not output to the exchange 21 and the normal operation, that is, the hold state is continued.

Hereinafter, embodiments of the present invention will be described in more detail. FIG. 3 is a detailed circuit diagram of the first embodiment of the present invention. A switch 27 is connected to the holding circuit 25, and when the holding key 27 is pressed, the holding circuit 25 recognizes that the holding is
Output level. This H level is applied to the base of the transistor Tr1 via the resistor R1. The transistor Tr1 is turned on by this H level, and the row lines Row1 and Row2 are diode-connected.
Connect to ground via D1 and D2. The dialer IC23 constantly monitors the connection state of the column and row, and has two row lines.
Since Row1 and Row2 are low, it is determined that a plurality of keys are pressed at the same time, and there is no effect on the line. As a result, the dial pulse is not transmitted to the line, and the normal state is maintained. When one of the dial keys is pressed, the low line of the dialer IC 23 falls from H and generates a plurality of low-level pulses, as shown in FIG. In FIG. 4, five low pulses are generated. The column line of the dialer IC generates a plurality of H-level pulses. The connection is detected by the generation of the pulse of the row line and the column line, and if the dialer IC 23 is in the push button mode, a push button dial signal is output to the line via the communication path 24 '. When the mode is the dial pulse mode, a pulse corresponding to the number, that is, a so-called break make is repeated (corresponding to the dial number). As shown in FIG. 5, during normal dialing, the first embodiment of the present invention operates exactly the same as the operation of FIG. 4, and the collector of the transistor Tr1 is in an open state (high impedance: Hz). When a dial key (Row1, Col1) corresponding to a row or a column is pressed, the row terminal Row1 of the dialer IC23 becomes L level and the column terminal Col1 remains in the L level state, and the dialer IC23 becomes the row terminal Row1 and the column terminal Col1. It detects that a switch as a connection point has been pressed. The other row terminals and column terminals are in a state where a pulse is generated.

FIG. 6 is an operation timing chart in the hold state. When the operator presses the hold key 27 once (AC1), the output of the hold circuit 25 becomes H level, a current flows to the base via the resistor R1, the transistor Tr1 is turned on, and the collector of the transistor Tr1 is in a high impedance (Hz) state. To the L level state. Due to the change in the L level, the row terminals Row1 and Row2 become L level, which is equivalent to a state in which a plurality of keys are simultaneously pressed. At this time dialer IC
Pulses equivalent to those shown in FIG. 4 are generated at the 23 column terminals Col1, other row terminals, and other column terminals.

In the first embodiment of the present invention described above, the diode
Although the row terminals Row1 and Row2 are set to L level when the transistor Tr1 is turned on by D1 and D2, other methods are also possible. FIG. 7 is a detailed circuit diagram of the second embodiment of the present invention. In the embodiment of FIG. 7, the row terminals Row1, Row
2 is set to L level by transistors TR2 and TR3.
At this time, the transistors Tr2 and Tr3 are turned on by the H level from the hold circuit 25 via the resistors R2 and R3.

4 and FIG.
The row line is grounded by turning off the switch, but this is not restrictive. FIG. 8 is a detailed circuit diagram of the third embodiment of the present invention. In the third embodiment, the analog switches AN1 and AN2 are turned on by the H level from the hold circuit. In the case of the embodiment shown in FIG. 8, one of the analog switches AN1 and AN2 is not grounded and the other column terminal Col1 is not grounded.
The same applies to connection to ~ Col4. In this case, it is the same as pressing two switches, so that the dialer IC 23 similarly judges that the switch has been abnormally pressed, and invalidates the erroneous operation of the key in the hold state without outputting a dial pulse.

〔The invention's effect〕

As described above, according to the present invention, an erroneous key operation in a hold state of a hold phone is invalidated and no dial pulse is output, so that an erroneous disconnection of a line or the like can be prevented. Further, it is possible to prevent unnecessary push button dial signals from being transmitted to the other party.

[Brief description of the drawings]

1 is a block diagram showing the principle of the present invention, FIG. 2 is a system configuration diagram of an embodiment of the present invention, FIG. 3 is a detailed circuit diagram of the first embodiment of the present invention, and FIG. FIG. 5 is an operation timing chart for a normal dial, FIG. 6 is an operation timing chart for a hold state, FIG. 7 is a detailed circuit diagram of the second embodiment, and FIG. FIG. 9 is a block diagram of a dialer IC according to a third embodiment of the present invention. 1 ... key matrix circuit, 2 ... dial sending circuit, 3 ... holding circuit, 4 ... key pressing invalidation circuit, 5 ... communication circuit.

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Ichiro Takahashi 3-9-1-18 Shin-Yokohama, Kohoku-ku, Yokohama-shi, Kanagawa Prefecture Inside Fujitsu Daiichi Tsushin Software Co., Ltd. (72) Mitsuo Nakajima Shin-Yokohama, Kohoku-ku, Yokohama-shi, Kanagawa 3 No. 9-18, Fujitsu Daiichi Tsushin Software Co., Ltd. (72) Inventor Atsushi Murai 2-18-2 Nishigotanda, Shinagawa-ku, Tokyo Hasegawa Electric Works, Ltd. (56) References JP-A-60-206355 (JP, A) Shokai Sho 62-169553 (JP, U) (58) Fields investigated (Int. Cl. ⁶ , DB name) H04M 1/27

Claims (2)

(57) [Claims] 1. A telephone, comprising: a key matrix circuit (1) having a dial key; detecting press of the dial key; transmitting a dial (DP) signal corresponding to the pressed dial key; When the double press state is detected, the dial signal (D
A dial sending means (2) that does not send P), a hold circuit (3) that detects the press of the hold key and holds the call, and a double press of the dial key while the hold circuit (3) is operating. A key press invalidation method characterized by comprising a key press invalidation circuit (4) for forming a state. 2. The system according to claim 1, wherein said telephone further comprises a communication circuit for transmitting a hold melody generated when said hold circuit is on hold to said line.