JP2000253158A - Intercom - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide the structure of an intercom, capable of preventing any abnormal operation that call calling input is repeated in the state of the presence and absence of calling. SOLUTION: When a call-calling button 1 is operated, and any pulse voltage is not outputted, a signal for indicating the presence of call-calling is outputted to a call-calling input terminal 2a. When the call-calling button 1 is operated, and a pulse voltage is outputted, a signal for indicating the absence of call- calling is outputted to a call calling input terminal 2a in this intercom device. Only when pulse voltage is not outputted, will the signal inputted to the call calling input terminal 2a be judged.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a door phone device for making a call between a door phone slave unit and a door phone master unit, and more particularly to a door phone device provided with a call call button.

[0002]

2. Description of the Related Art Conventionally, a door phone device is provided outdoors such as an entrance, and a door phone master device is provided indoors for making a telephone call. Is operated, a ringing tone sounds in the intercom master unit, and a display indicating that there is a call flashes. Further, a display means is provided on the call call button side, and a signal indicating that a call is being performed by applying a pulse voltage for display blinking on a signal line connecting the door phone master unit and the call call button is displayed on the call call button side. There was something configured to do. FIG. 1 shows a circuit of the doorphone device thus configured.

FIG. 1 shows a call call button 1, a control integrated circuit 2 connected to the call call button 1, built in the door phone master unit, and a call call button 1 and the control integrated circuit 2. FIG. 3 is a circuit diagram showing only a circuit of a call circuit (call call block 3). The control integrated circuit 2 has a call call input terminal 2a that is active at a low level, and a low call input terminal 2a.
A call display output terminal 2b which is active at the level is provided, and a signal indicating that a call is being made from the call call button 1 is transmitted to the control integrated circuit via the call call block 3 and the call call input terminal 2a. 2, a signal for performing a blinking display indicating that a call is being made from the control integrated circuit 2 via the call display output terminal 2b and the call call block 3 is output to the call call button 1 side.

The call call button 1 (internal resistance r) is connected to connection terminals N1 and N2, a zener diode ZNR is connected between the connection terminals N1 and N2, and the connection terminal N2 is grounded. The connection terminal N1 is connected to the call call input terminal 2a of the control integrated circuit 2 via the diode D1 and the transistors TR121 and DT121.

On the other hand, a call display output terminal 2b is connected to the base of a transistor DT124 connected in series with a series circuit of a call display LED for displaying a blinking call on the side of the intercom master unit and a resistor R124. The collector of the transistor DT124 is further connected to the transistors DT123 and DT122. A series circuit of a resistor R125 and a diode D2 is connected to the collector of the transistor DT122.
Is connected to the connection terminal N1.

The operation of the circuit shown in FIG. 1 will be described. When call call button 1 is pressed, transistor TR1
21 and DT121 are turned on, and a low-level signal is input to the call calling input terminal 2a. The control integrated circuit 2 detects this, and the door phone master unit (not shown)
A pulse voltage signal (frequency of 3 Hz) is displayed in order to make a ringing sound of "Poppup" sound from a main body speaker (not shown) provided in the telephone and to blink a call display LED provided in the door phone master unit. Output from the output terminal 2b. Also, this pulse voltage signal is
The voltage is applied to the connection terminal N1 via the resistor R125 and the diode D2, and the display means (not shown) provided on the call call button 1 side blinks.

The call call input terminal 2 of the control integrated circuit 2
a, when the input voltage is 5 V (High level), the apparatus is in a standby state without call calling, and the input voltage is 0 V (L
(low level), it is configured to detect that there is a call, and if the input voltage is 0 V, a ringing and blinking display indicating that there is a call is performed.
In the case of V, it is always in the detection state.

[0008]

SUMMARY OF THE INVENTION In the circuit shown in FIG.
In a standby state where the call call button 1 is not pressed, the voltage of the connection terminal N1 is 12 V, whereby the transistor TR121 and the diode D1 are turned off,
The input voltage of the call calling input terminal 2a of the control integrated circuit 2 is 5V.

Next, the state in which the call call button 1 is pressed will be described. Assuming that the internal resistance r of the call call button 1 is 0Ω, the potential of the connection terminal N1 becomes 0V, whereby the transistor TR121 and the diode D1 are turned on, and a voltage is applied to the call call input terminal 2a of the control integrated circuit 2. When 0 V is input, a pulse voltage signal is output from the call display output terminal 2b of the control integrated circuit 2 to the connection terminal N1 via the resistor R125 and the diode D2. In this case, the transistor DT122 is turned on, but since the potential of the connection terminal N1 is 0 V, the on state of the transistor TR121 is continued.

Next, a case will be described with reference to FIG. 2 where the internal resistance r of the call calling button 1 is increased to 8 kΩ. FIG. 2 is an explanatory view showing various signals. (1) is a pulse voltage signal (display pulse output) output from the call display output terminal 2b, (2) is a terminal voltage of the connection terminal N1,
(3) is a voltage (microcomputer terminal voltage) input to the call calling input terminal 2a.

When the internal resistance r of the call button 1 increases to, for example, 8 kΩ, the call button 1 and the resistor R12
1 and 122, the voltage of the connection terminal N1 becomes about 4.8 V, as shown in FIG.
Thus, the base voltage of the transistor TR121 becomes approximately 11.4 V, and the transistor TR121 is turned on. As a result, the transistor DT121 is turned on, and as shown in FIG.
Is input to the call call input terminal 2a, and a call call is made. This state is detected by the control integrated circuit 2, and the resistance R1
2 and a connection terminal N1 through a diode D2, as shown in FIG.
As shown in (1), when a pulse voltage signal is applied,
The transistor DT122 is turned on, and FIG.
As shown in (5), the potential of the connection terminal N1 is about 8.94 V, the base voltage of the transistor TR121 is about 11.78 V, and the transistor TR121 is turned off. As a result, as shown in FIG. 2 (3), a voltage of 5 V is input to the call call input terminal 2a of the control integrated circuit 2, and a call is not made. However, if the transistor DT122 is turned off, As shown in FIG. 2 (2), the voltage of the connection terminal N1 again becomes 4.8 V, and the state where there is a call is made again. Thereafter, this operation is repeated.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-described problems, and has as its object the purpose of interlocking with a display pulse indicating that there is a call call, and changing the call call input to a state of calling or not calling. An object of the present invention is to provide a structure of a door phone device that can prevent repeated abnormal operations.

[0013]

According to a first aspect of the present invention, there is provided a door phone apparatus, wherein a call call button and a signal inputted to a call call input terminal determine whether or not a call is present. A control integrated circuit that outputs a pulse voltage for blinking display from the call display output terminal to the call call button side when the judgment is made, and when the call call button is operated and the pulse voltage is not output, A signal indicating that a call exists is output to the call input terminal, and a signal indicating that no call exists is output to the call input terminal when the call button is operated and a pulse voltage is output. The intercom apparatus determines the signal input to the call calling input terminal only when the pulse voltage is not output, and determines whether the pulse voltage is output. It is characterized in that it is configured to ignore a signal input to a call call input.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The intercom apparatus of the present invention is to prevent the above-mentioned abnormal operation by changing the method of detecting a call call of the control integrated circuit 2, and therefore is based on FIG. The doorphone device of the present invention will be described. FIG. 1 shows a call call button 1, a control integrated circuit 2 connected to the call call button 1, which is built in the door phone master unit, and a circuit formed between the call call button 1 and the control integrated circuit 2 ( In the circuit diagram showing only the circuit of the call call block 3), the control integrated circuit 2 is provided with a call call input terminal 2a which is active at a low level and a call display output terminal 2b which is active at a low level. And a signal indicating that a call is being made from the call call button 1 is sent to the call call block 3 and the call call input terminal 2a.
Is input to the control integrated circuit 2 via the call display output terminal 2b and a call display button 2b and a signal for performing a blinking display indicating that a call is being made from the control integrated circuit 2 via the call call block 3. Output to the side.

The call call button 1 (internal resistance r) is connected to connection terminals N1 and N2, a Zener diode ZNR is connected between the connection terminals N1 and N2, and the connection terminal N2 is grounded. The connection terminal N1 is connected to the call call input terminal 2a of the control integrated circuit 2 via the diode D1 and the transistors TR121 and DT121.

On the other hand, the call display output terminal 2b is connected to a base of a transistor DT124 connected in series with a series circuit of a call display LED and a resistor R124 for causing the door phone master unit to blink and display that there is a call. The collector of the transistor DT124 is further connected to the transistors DT123 and DT122. A series circuit of a resistor R125 and a diode D2 is connected to the collector of the transistor DT122.
Is connected to the connection terminal N1.

Next, a description will be given of an operation for preventing an abnormal operation in which a call input is repeated with and without a call. The present invention is characterized in that a calling state is detected only when the display pulse output shown in FIG. 2A is in an OFF state (a state in which no display pulse is output). The diagram of FIG. 2D is a diagram showing a period during which the control integrated circuit 2 detects the state of the signal input to the call calling input terminal 2a, and the diagram of FIG. FIG. 2 shows that the control integrated circuit 2 is configured to detect the state of the signal input to the call call input terminal 2a only when the display pulse output of 2 (1) is in the OFF state. When the display pulse output of (1) is in the ON state, the control integrated circuit 2 is configured not to detect and ignore the state of the signal input to the call call input terminal 2a.

With this configuration, when the internal resistance r of the call call button 1 increases to, for example, 8 kΩ, a pulse voltage signal is applied to the connection terminal N1 as shown in FIG. (Display pulse output) is output, and the transistor DT122 is turned on. As shown in FIG. 2C, the potential of the connection terminal N1 is about 8.94V, the base voltage of the transistor TR121 is about 11.78V, and the transistor TR121 is Is turned off and the control integrated circuit 2
The control integrated circuit 2 changes the state of the signal input to the call call input terminal 2a when the display pulse output is in the ON state even when the high-level voltage 5V is input to the call call input terminal 2a. Since it is not detected and ignored, it is possible to prevent detection of a state where there is no call ringing,
It is possible to prevent an abnormal operation that repeats a state with and without a call.

[0019]

According to the door phone apparatus of the first aspect,
Even if the internal resistance of the call button is increased, the configuration is such that the call input is detected only when the display pulse output is in the OFF state, thereby preventing an abnormal operation in which a call is made and a call is not made repeatedly. be able to.

[Brief description of the drawings]

FIG. 1 is a circuit diagram showing a circuit of a door phone device of the present invention.

FIG. 2 is a diagram for explaining the operation of the door phone device of the present invention.

[Explanation of symbols]

 1 Call Call Button 2 Control Integrated Circuit 2a Call Call Input Terminal 2b Call Display Output Terminal

Claims (1)

[Claims] A call input button and a signal input to a call input terminal determine whether or not a call is present. When it is determined that a call is present, the call display output terminal is used to determine whether a call is present. A control integrated circuit that outputs a pulse voltage for blinking display on the button side, and when the call call button is operated and no pulse voltage is output, a signal indicating that a call call is present at the call call input terminal. With the output, when the call call button is operated and a pulse voltage is output, a door phone device that outputs a signal indicating that there is no call call at the call call input terminal. Only judges the signal input to the call call input terminal, and ignores the signal input to the call call input terminal when the pulse voltage is output Intercom apparatus characterized by being configured to so that.