BACKGROUND OF THE INVENTION

Field of the Invention

This invention relates to a coin/card operated public telephone and its controlling method, and more particular¬ ly to a coin/card operated public telephone capable of making local, toll, and international calls using coins, credit card, or IC (Integrated Circuit) card and of being centrally managed from a remote location and to its controlling method.

Information Disclosure Statement

Generally, public telephones of a coin-type, pre-paid card type, and post-paid card type are available for use to the public. In a coin-type telephone, a caller can make a call by inserting certain amount of coins into the public telephone. However, a caller experiences difficul¬ ties in making a long-distance call, long lasting call, and international call since the coin-type telephone can only accommodate a limited amount of coins at one time.

In a pre-paid card type telephone widely used today, a caller can make a call by inserting a plastic card (2000, 3000, and 5000 Wons) into the public telephone. However, the disadvantages are that the content of card can be easily damaged and erased due to its weak coercive force and the amount of information that can be recorded in the pre-paid card type telephone is limited. There- fore, it is extremely difficult to make the functional improvements and provide additional services.

In a post-paid card type telephone, a caller pays for the calls he has made through the post-paid card type

telephone using his credit card afterwards.

Due to the problems of telephone hardwares, the existing types of public telephones mentioned above are not capable of providing services such as informing the receiver's telephone number and announcing the time used. Also, since their built-in memories must be replaced in order to change programs or call charges per unit, maintenance cost/time is increased because a manager must maintain and repair the public telephones and thus, dropping their efficiency.

SUMMARY OF THE INVENTION

It is an object of the present invention to provide a coin/card operated public telephone capable of making local, toll, and international calls using coins, credit card, or IC card as well as to provide a controlling method which will carry out the functions required to eliminate the previously mentioned disadvantages.

It is another object of the present invention to pro¬ vide a coin/card operated public telephone capable of making voice announcements regarding its operation method to the caller through the handset.

It is still another object of the present invention to provide graphic/character information through LCD (Liquid Crystal Display) of the coin/card operated public telephone in Korean as well as in English characters.

It is still another object of the present invention to provide a coin/operated public telephone capable of transmitting fault status that has been detected as a result of a highly reliable self-diagnosis carried out by receiving control signals from a remotely located central management system.

In order to accomplish the above mentioned objec¬ tives, the public telephone of the present invention comprises a controller that controls the entire telephone, a memory that stores programs and data, a speech circuit for interfacing with the telephone lines and for voice transmission, a coin processing unit used to select and store coins, a card reader used to read and write an IC card and magnetic credit card, a modem used for authoriz¬ ing a magnetic credit card data transmission, a voice synthesizing circuit for service announcement through voice, an LCD for character/graphic information display, a keypad for inputting telephone number, special buttons used for an emergency call, re-dialing, sound control and language selection, function buttons used for the IC card, various sensors for central management, and a power supply unit used to supply power to the entire telephone.

To accomplish the objectives of the present invention according to a method for controlling the coin/card public telephone, all the data are initialized from the start signal and automatic diagnosis is carried out to find out whether any fault has occurred. If any fault is found by the above automatic diagnosis, a step where the fault is found is recorded and an evaluation on impossibility of making a call is made.

When no fault is found and it is possible to make a call, an evaluation is made to find out whether the diagnostic switch is activated. In case the diagnostic switch is activated, a diagnosis is carried out and its result is recorded.

But, in case the diagnostic switch is not activated, an evaluation to find out whether coins have been inserted properly is made. When the evaluation carried out in the above step shows that the coins have been inserted properly, a call may be made in a coin call mode.

If the coins have not been inserted, an evaluation is

made to find out whether a credit card has been inserted. When the credit card has been inserted, a call may be made in a credit card call mode.

If the credit card has not been inserted, an evaluat¬ ion is made to find out whether an IC card, instead of a credit card, has been inserted. When the IC card has been inserted, a call may be made in an IC card call mode.

In case the IC card has not been inserted, an evalua¬ tion is made to find out whether an emergency button has been activated. When the emergency button has been activated, a call may be made in an emergency call mode.

If the emergency button has not been activated, an evaluation on On-hook state is made. If the telephone is not in On-hook state, the telephone returns to the evalua¬ tion step in order to find out whether the diagnosis switch was activated when no fault was found and whether the call may be made■

As described above, local, toll, and international calls can be made. Moreover, since the centralized management is possible from a remote location by using the coin/card operated public telephone according to the present invention, a more efficient maintenance and repair service may be accomplished.

BRIEF DESCRIPTION OF DRAWINGS

For fuller understanding of the nature and objects of the invention, reference should be had to the following detailed description taken in conjunction with the accompanying drawings in which:

Fig. 1 is a configuration diagram depicting an opera¬ tional environment of a coin/card operated public telephone according to the present invention.

Fig. 2 is a configuration diagram of a coin/card ope ^¬ rated public telephone according to the present invention.

Fig. 3A through Fig.3B are flow charts on the operations described in Fig.2.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

The novel feature of the present invention may be understood from the accompanying description when taken in conjunction with the accompanying drawings where similar reference characters refer to similar parts throughout the several views of the drawings.

Fig. 1 is a configuration diagram of operational environment of a coin/card operated public telephone used to describe the characteristics according to the present invention. As shown in Fig. 1, the coin/card operated public telephone 30 is connected to a Public Telephone Network 40 and the Public Telephone Network 40 is connected to a Credit Authorization Unit 50 and a Public Telephone Central Management System 60. Each of the Credit Authorization Unit 50 and the Central Management System 60 has a first and second interface units 17, 18 used for interfacing with the Public Telephone Network 40, respectively. Two data banks 70 and 80, used to record the balance of a credit card, are connected to the Credit Authorization Unit 50.

When coins are inserted into a coin/card operated public telephone 30, a caller can make a call with a called party via the Public Telephone Network 40. When a credit card is inserted into the public telephone, the public telephone checks whether the inserted credit card is a valid one using data bank 70 and 80 connected to the Credit Authorization Unit 50 and informs the result to the caller by means of voice or character/graphic displayed on the LCD. If the credit card is a valid one, a caller may

make a call to a subscriber he likes to converse with via the Public Telephone Network 40.

On the other hand, the information on billing details and fault status of the public telephone 30 are sent to the Public Telephone Central Management System 60 when the public telephone 30 receives an information request signal from the Central Management System 60. The Central Management System 60, upon receiving the information from the public telephone 30, analyzes them and outputs messages corresponding to the information received.

Fig. 2 is a configuration diagram according to the public telephone of the present invention. As shown in Fig. 2, a coin processing unit 20 used to select and store coins that had been inserted, a card reader 14 for reading and writing an IC card/credit card, a memory unit 12 for storing various programs and data, an LCD 10 for displaying information as character and graphic, a keypad and buttons 11 for inputting telephone numbers, a sensor unit 13 consisting of various sensors used for central management, and a power supply unit 15 used for supplying power are connected to a controller 16 that controls the entire system.

Moreover, a voice synthesizing circuit 7 used for voice announcement service, a DTMF (Dual Tone Multi Frequency) generating unit 8 used to generate DTMF signal by inputting telephone numbers through the key pad and buttons 11, and a modem 9 used for data transmission with a credit authorization unit 50, a public telephone central management system 60, are connected to the controller 16. Furthermore, a speech circuit 6 used for interfacing with the telephone line from the voice synthesizing circuit 7, the DTMF generating unit 8, and the modem 9 and for transmitting voice is connected to the controller 16 and a handset 1 used for calls made to the called parties is connected to the speech circuit 6.

The operations carried out by the public telephone according to the present invention will now be described in detail.

In case of a coin operated call, when a caller lifts up the handset 1 and inserts the coins (more than basic charge) into the slot of the public telephone, a coin selector 2 discriminates the coins and then stores the coins in a coin storage unit 3. At the same time, a relay 5 is activated in order to seize the exchange line (Off- hook state) and the amount of the inserted coins is displayed on an LCD 10. As telephone numbers are inputted via a key pad and buttons 11, DTMF signals are generated at a DTMF generating unit 8 and a speech circuit 6 is connected to a Public Telephone Network 40 in order to make a call circuit with the called party. Therefore, the caller can converse with the called party through the handset 1 of the public telephone. As soon as the call is over, the coins that had been stored in the coin storage unit 3 are transferred to the coinbox 4.

In case of a card-operated call, a controller 16 of the public telephone reads the card content through a card reader 14 and calls a credit authorization unit 50 through a DTMF generating unit 8 after the caller lifts up the handset 1 and inserts a card into the card reader 14. Once the credit authorization unit 50 is connected, the controller 16 sends the data, that had been read, to the modem 9. The modem 9 modulates the data that had been inputted and sends them to the credit authorization unit 50 through a speech circuit 6 and the Public Telephone Network 40. The credit authorization unit 50 searches the received data and sends the searched result to the modem through the Public Telephone Network 40 and speech circuit 6. The modem 9 demodulates the searched result and inputs it into the controller 16. In other words, if the searched result shows.that the card is a valid one, the controller 16 activates the relay 5 and connects the exchange line. Then, the caller can make a call and start

to talk to the called party by pressing the telephone numbers of called party through the key pad and buttons 11 after hearing the dial tone.

When the call is over, the public telephone stores the billing information of the call in a memory unit 12. Thereafter, when the next caller make a call, the public telephone notifies this information to the credit authorization unit 50 through the modem 9. In case the card is detected to be an invalid one, the controller 16 transmits the voice data from the memory unit 12 to the voice synthesizing unit 7 and the voice synthesizing unit 7 combines the voice by assembling the voice data and verbally informs the caller that the card is an invalid one. At the same time, it notifies the caller such fact by characters and graphics displayed on the LCD 10.

In case of a call using an IC card, after a caller lifts up the handset 1 and inserts an IC card into the card reader 14, the controller 16 reads the amount recorded in the IC card and activates the relay 5 for exchange line connection if the amount that has been read exceeds the local charging unit. Then, the caller can press the number of called party through the key pad and buttons 11 and make a call with the called party after hearing a dial tone. When the caller first hears a charging pulse during the conversation, the unit charge is subtracted from the amount displayed on LCD.

The remaining amount and charging unit is compared for continuous charging pulse. If the remaining amount is less than the unit charge, the exchange line is dis¬ connected (On-hook state) . If the remaining amount is greater than the unit charge, it is subtracted. This procedure is repeated until the caller terminates the call.

On the other hand, the sensor unit 13 ^' detects the door open status, handset disconnection status, internal

battery voltage, AC power supply voltage, line current and voltage, surrounding temperature and humidity. As the central management system 60 requests the data collected as a result of detection, the sensor unit 13 sends them to the central management system 60.

Fig. 3A through 3B are flow charts used to explain the operations described in Fig.2.

As shown in Fig. 3A, all the data are initialized in step 101 from the start signal generated by lifting up the handset and the operation proceeds to step 102. In step 102, an automatic diagnosis of a coin/card operated public telephone is carried out and the operation proceeds to step 103. In step 103, an evaluation to find out whether any faults had occurred in the public telephone is carried out.

If faults are found, fault details are recorded in step 104 and the operation proceeds to step 105. If no fault had occurred in step 103, the operation proceeds to step 106. In step 105, if the call is evaluated to be impossible, the operation is terminated and if the call is evaluated to be possible, the operation proceeds to step 106. In step 106, an evaluation as to whether the diagnostic switch is in an activated state is made. If the diagnostic switch is activated, the operation proceeds to step 107 to carry out the diagnosis. Then, the result of the diagnosis is recorded and the activation is ter- minated. If the diagnostic switch is not in an activated state, the operation proceeds to step 108 where an evaluation as to whether the coins have been inserted properly is made.

If the coins have been properly inserted in step 108, the operation proceeds to step 109 so that the public telephone changes into a coin call mode. Thereafter, the activation is terminated after completing the call. If no coins have been inserted, the operation proceeds to step

110 where an evaluation to find out whether the credit card has been inserted is made. If the credit card is found to have been inserted in step 110, the operation proceeds to step 111 so that the public telephone changes into a credit card call mode. Thereafter, the activation is terminated after completing the call. If the credit card is found not to have been inserted, the operation proceeds to step 112 where an evaluation to find out whether the IC card has been properly inserted is made. If the IC card is found to have been inserted in step 112, the operation proceeds to step 113 and the public tele¬ phone changes into an IC card call mode and then stops activating after completing the call. If the IC card has not been properly inserted, the operation proceeds to step 114 where an emergency button is in an activation state. If the emergency button is in an activation state, the operation proceeds to step 115 so that the public telephone changes into the emergency call mode. Thereafter, the activation of public telephone is ter- minated after completing the call. If the emergency button is not in an activation state, the operation proceeds to step 116. In step 116, an evaluation to find out whether the public telephone is in on-hook state is carried out. If it is in on-hook state, the activation terminates and if not, the operation returns to step 106.

Fig. 3B is a flow chart illustrating the status of the coin/card operated public telephone 30 and the trans¬ mission of the call information and the termination of the activation of the coin/card operated public telephone 30 when the public telephone receives a call from the central management system 60 in on-hook mode.

Although this invention has been described in its preferred form with a certain degree of particularity, it is appreciated by those skilled in the art that the present disclosure of the preferred form has been made only by way of example and that numerous changes in the details of the construction, combination and arrangement

of parts may be restored to without departing from the spirit any scope of the invention.