JPH0362662A - Telephone set - Google Patents

Abstract

PURPOSE:To prevent a caller from being charged due to the arrival of a call regardless of the absence of the caller by providing a loop sensing means, a timer and a loop forming means or the like and forming a DC loop forcibly when a handset is hooked off. CONSTITUTION:An identification means 9a sends an identification signal (c) only when the means 9a receives both a signal representing it that no DC loop of a speech circuit 2 is formed from a loop detection circuit 7 and a signal representing a permanent call of a handset 6 from a hook switch 1. A timer drive means 9b starts/stops a timer 8 depending on the presence of the signal (c) and when the timer 8 is started, it drives a timer detection means 9c and a loop forming means 9e after a prescribed time to forcibly form a DC loop of the circuit 2. The restoration is implemented by a restoration means 9a or the like depending on a grip signal of the handset 6 resulting from a pressure sensor 6a and an on-hook signal. Thus, a problem of the arrival of a call in the state of permanent call and the charge of the caller regardless of the absence of the caller is prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a telephone set having a function of preventing the handset from falling off.

[Prior art] In conventional general dial-tone first telephones where a DC loop is formed immediately after off-hook, if the handset is disconnected from the hook switch for a certain period of time, a howling sound is sent from the exchange and the handset is disconnected. We urge you to be careful about what is happening.

FIG. 3 is a block diagram showing an example of a conventional public telephone.

Normally, when the handset 6 is off-hook, the hook switch (H3) 1 is simply closed and a DC loop is not formed.When a coin or magnetic card is inserted, the billing processing unit 4 detects the insertion, and the call control relay (LP) 3 A DC loop is formed only when the

[Problems to be Solved by the Invention] In other words, in a public telephone, if the handset 6 is disconnected, a DC loop is not formed, so the exchange cannot detect the abnormal state, so the howler sound is not transmitted. When a calling signal arrives when the handset 6 remains disconnected and a DC loop is not formed, a DC loop is formed in the communication circuit 2. Also, on the calling party side, after sending the dial signal, a ringing tone (RBT) is heard.
There was a problem in that the caller would be charged if the caller answered without a message, resulting in a call state.

The present invention has been made to solve the above-mentioned problems, and it is an object of the present invention to provide a telephone that can detect when its own handset is disconnected and can recover from the disconnection.

[Means for Solving the Problems] In order to achieve the above object, the telephone of the present invention is a telephone in which a DC loop is formed after the handset is removed from the hook switch and a coin or magnetic card is inserted. loop detection means for detecting whether or not a DC loop is formed; identification means for outputting an identification signal C when the loop detection means determines that a DC loop is not formed and the handset is disconnected from the hook switch; a timer driving means for starting a timer in response to an identification signal from the identification means; a timer started by the timer driving means to measure time for a certain period of time; and a timer detection means for detecting the end of time measurement for a certain period by the timer; The present invention is characterized by comprising: loop forming means for forcibly forming a DC loop by detection by the timer detecting means.

[Operation 1] When the transmitter/receiver provided on the telephone body is disconnected from the hook switch and the DC loop is not formed for a certain period of time, the DC loop is forcibly connected by the loop forming means.

As a result, a howling sound is sent out from the exchanger, alerting those around you that the handset is disconnected, and the abnormal condition is canceled by re-hooking the handset to the hook switch.
It is possible to return to normal state.

[Embodiment] FIG. 1 is a block diagram showing a public telephone set as an embodiment of the telephone set of the present invention.

The loop detection circuit 7 detects whether or not a DC loop is formed in the communication path in the public telephone set, and outputs a detection signal a to the identification means 9a.

The hook switch 1 is provided on the main body of the public telephone and detects whether the handset 6 is disconnected from the hook switch 1 and outputs a detection signal to the identification means 9a. Also, timer 8
is started by an instruction from the processing device 9, and after counting a predetermined time, the timer detection means 9 of the processing device 9
A signal e to that effect is sent to c.

The processing device 9 is responsible for the operations described below, and is composed of the following components.

The identification means 9a operates a timer only when both a signal from the loop detection circuit 7 indicating that a DC loop is not formed and a signal from the hook switch 1 indicating that the handset is disconnected from the hook switch l are input. An identification signal C to that effect is output to the means 9b.

The timer driving means 9b issues an activation instruction d to the timer 8 when the identification signal C is input. Then, when the signal is no longer output from the identification means 9a, a stop instruction is issued to the timer 8.

The timer detection means 9c sends a signal f to the loop forming means 9h when the timer 8 manually outputs a signal e indicating that the set time has been counted.
The loop forming means 9h thereby forcibly forms a direct current loop (LP) of the communication circuit 2.

A pressure sensor 6a is provided in the grip portion of the handset 6, and when the handset 6 is held by hand, a detection signal i indicating this is output to the return means 9g.

The return means 9g resumes communication via the loop forming means 9h when a detection signal i from the handset 6 indicating that it is being held is manually input, or when the handset 6 itself is hooked to the hook switch l. Cut the DC loop of circuit 2.

Next, the operation of the above configuration will be explained based on the flowchart of FIG.

When the handset 6 is disconnected from the hook switch ■, the user would normally remove the handset 6 to make a call, but if the handset 6 is left unplugged, [the problem to be solved by the invention] This results in the problem described in section.

Therefore, the identification means 9a always identifies the hook switch 1.
(5PI) to identify whether the handset 6 is disconnected or not.
If not, it is determined whether a DC loop is formed or not (SF3).

It is normally impossible that a DC loop is not formed here. In this state, the identifying means 9a activates the timer 8 and identifies whether or not time has expired (SF3).

When the handset 6 is normally hung on the hook switch l by the user, or the handset 6 is grasped by the user, or a DC loop is formed by inserting a coin or a magnetic card before the timer 8 times up. Then, the identifying means 9a resets the timer 8 via the timer driving means 9b to return to the initial state.

However, if the time-up occurs, the loop forming means 9
Activate h to form a DC loop of communication circuit 2 (S
F3).

At this time, even if a call is made to this public telephone, a busy tone will be sent out on the calling party's side, so that unnecessary charges will not be incurred.

Then, a howler sound will be transmitted from the exchange.

When a person near the public telephone picks up the handset 6, the pressure sensor 6a of the handset 6 is activated. After this, the handset 6 is hung on the hook switch l in a normal state, and the entire public telephone returns to its initial state (
SF3).

In addition, in the above-mentioned embodiment, it was explained that the pressure sensor 6a was used to detect the operating state of the handset 6, but in addition, a visual sensor such as a CCD may be used to detect the use of the handset 6. You can.

In addition, in the above embodiment, a public telephone was explained, but
The above-mentioned effects can also be obtained with a similar configuration for a KUNKU telephone.

[Effects of the Invention] According to the telephone of the present invention, disconnection of the telephone handset is self-detected and a DC loop is automatically formed, so that the abnormal condition is immediately notified to the surrounding people by sending out a howler sound from the exchange. I can let you know.

This makes it possible to reliably return an abnormal state to a normal state within a certain amount of time, so if a call is received while the handset is off, the caller will be charged even though there is no one on the other end. This can prevent the problem of

Conventionally, even if the handset of a public telephone is disconnected, it remains in place until the next person uses it, so in some cases the handset remains disconnected for quite some time.
In the case of the above-mentioned configuration, since it is possible to automatically recover even if the person is not the user of the garment, the abnormal state can be quickly escaped, and the above-mentioned effect is particularly effective.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing the main parts of the telephone according to the present invention, FIG. 2 is a flowchart showing the operation of the telephone, and FIG. 3 is a block diagram of a part of the telephone. l...Hook switch (H3), 2...Telephone circuit,
3... Call control relay (LP), 4... Billing processing section, 5... Dial, 6... Handset, 6a... Pressure sensor, 7... Loop detection circuit, 8...・Timer, 9
. . . processing device, 9a . . . identification means, 9b . . . timer drive means, 9c .

Claims (1)

[Scope of Claims] Loop detection means for detecting whether or not a DC loop is formed in a telephone in which a DC loop is formed after the handset is removed from a hook switch and a coin or magnetic card is inserted; an identification means that outputs an identification signal c when the means determines that a DC loop is not formed and the handset is disconnected from the hook switch; and a timer drive means that receives the identification signal from the identification means and starts a timer. a timer that is activated by the timer drive means to count time for a certain period of time; a timer detection means that detects the completion of time measurement for a certain period of time by the timer; and a loop formation that forcibly forms a DC loop by detection by the timer detection means. A telephone characterized by comprising means and.