JPH07170311A - Hook switch circuit for telephone set - Google Patents

Abstract

PURPOSE:To prevent unpleasant noises, caused by the contact of a transmitter/ receiver and the telephone set when speaking is finished, from being transmitted to a speaking line. CONSTITUTION:When a transmitter/receiver 2 contacts the telephone set 1, a hook switch 12 or a photocoupler 15 are operated, and the signal of on-hook is inputted to a control circuit 13. The control circuit 13 disconnects the speaking line as on-hook so as not to transmit the unpleasant noises to the speaking line.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hook switch circuit for a telephone, and more particularly to a hook switch circuit using sensors for a telephone body and a handset.

[0002]

2. Description of the Related Art A conventional hook switch circuit senses that a handset is placed in a telephone main body and is set in a call disconnection state.

There has been a device in which the transmission sound volume is adjusted by a sensor which senses that the handset is close to the telephone body (Japanese Patent Laid-Open No. 02-31342).

[0004]

Since the conventional hook switch circuit described above is in a call state until the handset is placed in the telephone body, the telephone body and the handset are placed just before the handset is placed in the telephone body. There is a drawback in that the unpleasant noise is generated by the contact with and the unpleasant noise is heard by the other party.

Further, since the transmission volume is adjusted by detecting that the handset is close to the telephone body, the transmission volume is adjusted when the handset and the telephone body are close to each other during a call. It has the drawback of making calls difficult.

[0006]

A hook switch circuit of the present invention has a first sensor attached to a telephone body and a second sensor attached to a handset, and a first sensor and a second sensor. It has a control circuit that senses and controls the contact of the.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, the present invention will be described with reference to the drawings.

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

In FIG. 1, a telephone body 1 according to this embodiment is shown.
And a handset 2 are provided, and the telephone body 1 has a first sensor 11 for detecting a contact of the handset 2, a hook switch 12, and a control circuit 13, and the handset 2 is a telephone. It is configured to have a second sensor 21 for detecting the contact of the main body 1, a transmitter 22, and a receiver 23.

Next, the operation of this embodiment will be described.

After the end of the call, when the handset 2 is brought into contact with the telephone body 1 in an attempt to be on-hook, the first sensor 11 and the second sensor 21 or the hook switch 12 act to bring the handset 2 into contact with the telephone body 1. Notify the control circuit 13 as on-hook. The control circuit 13 can disconnect the call line so that no unpleasant noise due to the contact between the telephone body 1 and the handset 2 is sent to the call line.

FIG. 2 is a circuit diagram of an embodiment of the present invention.

In FIG. 2, 11 is a first sensor and 2 is a sensor.
Reference numeral 1 is a second sensor, 13 is a control circuit, 14 and 18 are resistors, 15 is a photocoupler, 16 is a light emitting element, and 17 is a light receiving element.

Next, the operation of this embodiment will be described.

If the first sensor 11 and the second sensor 21 are not connected, the first sensor 11 is opened and no current flows through the light emitting element 16, so that the light emitting element 16 does not emit light. Since the light emitting element 16 does not emit light, the light receiving element 17
Does not receive light. Therefore, the light receiving element 17 does not operate and no current flows through the light receiving element 17. Therefore, the control circuit 13 is grounded via the resistor 18, the L level of the CMOS level is input, and the control circuit 13 is controlled as off-hook. Further, when the first sensor 11 and the second sensor 21 are connected, the first sensor 11 is grounded via the second sensor 21, so a current flows through the light emitting element 16 via the resistor 14 to emit light. The electric energy of the element 16 is converted into light energy, and the light emitting element 16 emits light. The light energy emitted by the light emitting element 16 is received by the light receiving element 17, and the light receiving element 17 operates by converting the received light energy into electric energy. Therefore, the H level of the CMOS level is input to the control circuit 13 via the light receiving element 17, and the control circuit 13 controls as on-hook.

[0016]

As described above, according to the present invention, the on-hook operation of the handset is sensed by the sensor, and the handset goes on-hook at the moment the handset comes into contact with the telephone body so that no unpleasant noise is transmitted to the telephone line. There is an effect that can be.

[Brief description of drawings]

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

FIG. 2 is a circuit diagram of an embodiment of the present invention.

[Explanation of symbols]

 1 Telephone main body 2 Handset 11 First sensor 12 Hook switch 13 Control circuit 21 Second sensor 22 Handset 23 Handset 14, 18 Resistance 15 Photocoupler 16 Light emitting element

Claims (1)

[Claims] 1. A telephone comprising a telephone body to which a first sensor is added and a handset to which a second sensor is added, wherein the telephone body and the handset are brought into contact with each other by the first sensor and the second sensor. A hook switch circuit comprising a control circuit configuration for detecting a thing and controlling a call line by the detection signal, and does not send on-hook noise at the end of a call to the call line.