JPH0153951B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Technical Field of the Invention) The present invention relates to a telephone having a hold function.

(Prior Art) A conventional telephone having a hold function generally has a block configuration as shown in FIG. 1st
In the figure, 1 is a connection terminal with a telephone line, 2 is a telephone switch, 3 is an incoming call circuit, 4 is a dial circuit, 5 is a dial switch, 6 is a communication circuit, 7 is a receiver, 8 is a transmitter, and 9 is a hold sound source. The circuit 10 is a hold switch that switches between a call state and a hold state. In this conventional example, in a call state, the transmitter 8 is connected to the call circuit 6 to enable the transmission of a call, and in a hold state, the hold sound source circuit 9 is connected to the call circuit 6, making it impossible to send a call. The hold sound generated by the hold sound source circuit 9 is transmitted to the line through the telephone call circuit 6. The dial circuit 4 is a circuit block that generates a dial signal (dial impulse or push button dial signal) corresponding to the dial number input by the dial switch 5 and sends it to the line. There are also many devices that have a so-called redial function that allows retransmission.

FIG. 2 shows the detailed configuration of the dial circuit 4, in which 4-1 is a key input interface circuit, 4-2 is a control circuit, 4-3 is a dial signal output circuit, and 4-4 is a memory circuit. , 4-5 is a clock circuit, and 4-6 is an oscillator for generating a reference clock. Next, the operation of this dial circuit 4 will be briefly explained. When the dial switch 5 is pressed down, the key input interface circuit 4-1 detects that a key has been pressed down, and provides a signal corresponding to the pressed key to the control circuit 4-2. Control circuit 4-
2 is a memory circuit 4 for storing a signal corresponding to a pressed key.
-4. Dial signal output circuit 4-3
generates a dial signal corresponding to the pressed key and sends it to the line. The clock circuit 4-5 generates a reference clock using the oscillator 4-6, divides the frequency of this reference clock as appropriate, and supplies necessary clock signals to other circuits.

Now, when the dial switch 5 is operated in a hold state with a telephone having a hold function configured as described above, the following problem occurs.

In the hold state, a hold tone is being sent to the other party, but when a dial operation is performed, the holding tone is interrupted and a dial signal is sent, causing discomfort to the other party.

Furthermore, in phones with a redial function, unnecessary dialing information is written into the redial memory, so the next time a redial operation is performed, a normal dial signal is followed by an unnecessary dial signal. It will be sent out. Therefore, it may not be possible to connect to the other party correctly.

(Object of the Invention) The present invention provides a telephone with a hold function configured to stop the dialing function in a hold state in order to solve the drawbacks of conventional telephones having a hold tone function in a hold state. .

(Structure and operation of the invention) The present invention will be explained in detail below.

FIG. 3 shows a first embodiment of the present invention, in which 10
A is one contact point of a hold switch 10 that switches between a call state and a hold state. In the hold state, the contact 10a of the hold switch operates, and the clock circuit 4-5
By connecting one end of the vibrator 4-6, which is connected to Even if you operate it, you cannot send out a dial signal.

In the embodiment shown in FIG.
The reference clock oscillation operation of the clock generation circuit is inhibited by the contact 10a, but the switching means for prohibiting this inhibition is a semiconductor device or the like that performs a switching operation using the power supply (not shown) of the hold sound source circuit 9. Good too.

FIG. 4 shows a second embodiment of the present invention, and shows 11
10b is the power supply of the key input interface circuit 4-1 of the dial circuit 4, and 10b is the 1 of the hold switch 10.
The contacts, V ⁺ and V ^- are the power supply terminals of the key input interface circuit 4-1, H1 to H3, L1 to L4 are connection terminals with the dial switch 5, and O1 to O7 are the outputs of the key input interface circuit 4-1. terminal,
Q1-Q3 are PNP transistors, Q4-Q10
is an NPN transistor, and R1 to R4 are resistors.
The contact 10b of the hold switch is "connected" in the call state,
In the hold state, the connection is "disconnected". In the call state, power is applied to the key input interface circuit 4-1, and for example, if the "1" button of the dial switch 5 is pressed,
Base current flows from the V ⁺ terminal to the transistors Q1 and Q4 via the route [resistor R1 → emitter/base of transistor Q1 → contact corresponding to the "1" button of dial switch 5 → base/emitter of transistor Q4 → V ^- terminal] flows, and the collector current of transistor Q1 conducts transistor Q8 through low resistor R2, so output terminals O1 and O4
A low level output signal is obtained for each. In the hold state, the contact 10b of the hold switch 10 is disconnected, so the power supply 11 of the key input interface circuit 4-1 is turned off, making all dial operations impossible.

In FIG. 4, a hold switch 10 turns off the power supply 11 of the key input interface circuit 4-1.
The contact 10b is the power supply (not shown) of the holding circuit 9.
It may also be a semiconductor element or the like that performs a switching operation.

(Effects of the Invention) As explained above, the present invention is configured to stop the operation of the dial circuit 4 in the hold state, so even if the dial switch 5 is operated intentionally or accidentally in the hold state, no dial signal is sent out. This will not cause discomfort to the other party, and no unnecessary data will be written to the redial memory.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing an example of the structure of a conventional telephone with a hold function, FIG. 2 is a block diagram showing an example of the detailed configuration of the dial circuit section of FIG. 1, and FIG. 3 is a first embodiment of the present invention. Block diagram showing the main parts of the 4th
The figure is a circuit diagram showing the main parts of a second embodiment of the present invention. 1...Telephone line connection terminal, 2...Hook switch, 3...Incoming circuit, 4...Dial circuit,
4-1...Key input interface circuit, 4-
2... Control circuit, 4-3... Dial signal output circuit, 4-4... Memory circuit, 4-5... Clock circuit, 4-6... Vibrator, 5... Dial switch, 6... Telephone call Circuit, 7...Telephone receiver, 8...Telephone transmitter, 9...Hold sound source circuit, 10...Hold switch, 10a, 10b...Hold switch contact, 1
1...Power supply for the key input interface circuit,
V ⁺ , V ^- ...Key input interface circuit 4-
1 power supply terminal, H1, H2, H3, L1, L2,
L3, L4... Connection terminal with dial switch 5, O1, O2, O3, O4, O5, O6, O7
...Key input interface circuit output terminal,
Q1, Q2, Q3...PNP transistor, Q4,
Q5, Q6, Q7, Q8, Q9...NPN transistor, R1, R2, R3, R4...resistance.

Claims (1)

[Claims] 1. A telephone circuit having a telephone call function, a dial circuit for sending a dial signal, a hold sound source circuit, and a switching means for switching between a call state and a hold state, and at least a part of the function of the call circuit when in the hold state. 1. A telephone with a hold function, characterized in that the telephone uses a hold tone to send out a hold tone, and is equipped with a switch means for stopping operation of a dial circuit when in a hold state.