JPH0747003Y2 - Public telephone - Google Patents

Description

[Detailed description of the device]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a public telephone which displays a remaining call time.

[0002]

2. Description of the Related Art Generally, in a public telephone, after a telephone user inserts a coin such as 10 yen or 100 yen into a coin insertion slot or a magnetic card into a card insertion slot,
Enter the telephone number of the destination telephone using the rotary dial or push-button dial. Then, a calling signal is transmitted from the in-office device (exchange) to the telephone set of the call destination designated by the telephone number. When the handset of the destination telephone is picked up and the hook switch is switched and connected to the telephone line side, the pulse period (charging interval) corresponding to the distance between the two telephones from the station device to the telephone of the calling party A charging pulse with is sent.

Each time the billing pulse is input, the inserted coin is stored, or the used call frequency stored in the magnetic card to enable the call is subtracted from the used call frequency. Also, 0.7-1. 3 to 5 seconds before the end of the callable time with the inserted coin or magnetic card.
A reminder sound is sent to the caller's phone prompting the call charge for 0 seconds.

[0004]

However, in such a public telephone, it is inconvenient because the user cannot grasp the remaining time of the callable time unless the reminder sound is input. Especially when talking for a long time,
Users often feel uneasy because they have no idea how much to call.

In order to avoid such a problem, a ROM memory for storing the long-distance telephone numbers nationwide and the billing intervals of billing signals corresponding to these long-distance numbers is provided inside the telephone,
Each time the telephone number of the destination is entered by dialing, RO
The callable time corresponding to this inserted amount is calculated from the billing interval corresponding to the area code read from the M memory and the inserted amount, and the call completed time is subtracted from this available time and displayed on the display unit. It is also possible to do it.

However, providing the ROM memory for storing the area codes of the whole country inside the telephone has a problem that the storage capacity of the ROM memory increases and the whole public telephone becomes very expensive. Further, since it is necessary to change the charging interval to be stored depending on the place where the public telephone is installed, there is a problem that the specifications of the public telephone must be changed depending on the installation place. Furthermore, it is necessary to replace the internal ROM memory each time the call charge is revised.

The present invention has been made in view of such circumstances, and it is expensive by counting the elapsed time from the input of the first charging pulse to the input of the next charging pulse as a charging interval by a counter. Without using various components
An object of the present invention is to provide a public telephone that can display the elapsed time until the second charging pulse is received, calculate and display the accurate remaining call time after that, and can improve the service to users.

[0008]

In order to solve the above problems, in the public telephone of the present invention, the elapsed time from when the first charging pulse is received to when the next charging pulse is received is measured, and A counter that measures the call elapsed time after receiving the next billing pulse and the elapsed time from the time when the first billing pulse measured by this counter is received until the time when the next billing pulse is received is stored. The charge interval memory and the elapsed time output from this charge interval memory are estimated.
The normalization circuit that normalizes and outputs the accurate charging interval by comparing with the set regular charging interval, and calculates the call frequency that can be called at this amount based on the amount information indicating the deposited amount A call can be made from the call frequency calculation circuit, the call frequency output from this call frequency calculation circuit, the charging interval output from the normalization circuit, and the call elapsed time from when the next charging pulse output from the counter is received. The remaining time calculation circuit that calculates the remaining time and the first charging pulse
From when the call started until the next charging pulse was received.
Shows overtime and talks after receiving the next billing pulse
And a display for displaying the remaining time available .

[0009]

In the public telephone thus constructed,
The call frequency calculation circuit calculates the call frequency at which the call can be made from the deposited amount. Further, the time from the input time of the first charging pulse to the input time of the second charging pulse is measured by the counter and stored in the charging interval memory, and the correct charging interval is obtained by the normalization circuit. From the call frequency obtained in step 1, the remaining time calculation circuit calculates the remaining available call time at that time.

From the time when the first charging pulse is input to the time when the second charging pulse is input, the elapsed time from the call start time is displayed. Then, after the second charging pulse input time, the remaining available call time during which the call can be made at the amount of money that has not been used for the call is displayed.

Therefore, even for a user who inserts a coin corresponding to one call frequency such as 10 yen to make a local call, a user who inserts a large number of coins at one time to make a local call for a long time, Alternatively, even a user who makes a long distance call by inserting a large number of coins at one time can enjoy the call while checking the remaining available time.

By providing a normalization circuit,
Since the remaining call time can be displayed more accurately, a more useful service can be provided to the user.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram showing a schematic configuration of a public telephone of the embodiment, in which 1 is a communication unit. The communication unit 1 is provided with a push button dial for generating a PB signal (push button signal), a handset, a charging pulse receiving circuit, a call circuit, and the like. The telephone line 2 is connected to an in-office device (exchanger) 3 in the telephone office. Further, the communication unit 1 is connected to a logic control unit 4 for controlling a call charge, a call time, etc., and a coin storage mechanism 5 for storing inserted coins is connected to the logic control unit 4. There is. Further, the communication unit 1 is connected with a display control unit 7 for controlling a display device 6 for displaying an elapsed time after the start of a call or a remaining call available time.

The display control section 7 is constructed, for example, as shown in FIG. That is, in the figure, 8 is the communication unit
This is a receiving circuit for receiving the charging pulse transmitted from the internal device 3 provided inside via the telephone line 2, and the charging pulse received by this receiving circuit 8 is input to the set terminal S of the counter 9. It is also input to the reset terminal R of the counter 9 via a flip-flop 10 having two stages. The clock signal of the 0.1 second cycle from the timer circuit 11 is input to the clock input terminal CP of the counter 9.

The count value CN of the clock signal measured by the counter 9 is output from the output terminal Q, temporarily stored in the charging interval memory 12, and then input to the normalization circuit 13. Then, the count value CN input to the normalization circuit 13 is input to one input terminal of the multiplication circuit 14 after being normalized to the accurate charging interval Tc.

On the other hand, the money amount information indicating the inserted money amount A output from the coin storing mechanism 5 is the call charge a per unit frequency.
Is input to the division circuit 16 together with the unit call charge a output from the unit charge memory 15 storing therein. The division circuit 16 divides the input amount A by the unit amount a to calculate the call frequency N corresponding to the input amount A. Thereafter, the subtraction circuit 17 subtracts the call frequency 1 corresponding to the call time from the time when the first charging pulse e is input to the time when the next charging pulse f is input from the call frequency N, and then the multiplication circuit 14 Input to the other input terminal. A call frequency calculation circuit 18 including the coin storage mechanism 5, the unit charge memory 15, and the division circuit 16.
Are configured.

In the multiplication circuit 14, the charging interval Tc from the normalization circuit 13 and the call frequency (N- from the subtraction circuit 17).
1) is multiplied by and the callable time To after the input of the next charging pulse f is obtained. The available call time To output from the multiplication circuit 14 is input to one input terminal of the next subtraction circuit 19. To the other input terminal of the subtraction circuit 19, the elapsed time T output from the division circuit 20 for calculating the elapsed time T obtained by reducing the count value CN output from the output terminal Q of the counter 9 to 1/10 is input. To be done.

The subtraction circuit 19 calculates the remaining talk time (To-T) by subtracting the talk time T from the talk time To and inputs it to one input terminal of the switching circuit 21. The division circuit 20 is connected to the other input terminal of the switching circuit 21.
The elapsed time T output from is input. The multiplication circuit 14 and the subtraction circuit 19 form a remaining time calculation circuit 22.

The charging pulse output from the receiving circuit 8 is input to the switching control terminal of the switching circuit 21 as the switching signal g through the flip-flop 23 having two stages. Therefore, the signal output to the next display unit 6 in response to the input of the next charging pulse f is the remaining time (To−) that the elapsed time T from the division circuit 20 is subtracted from the subtraction circuit 19.
T)). Further, the coin amount A from the coin storing mechanism 5 is also input to the switching circuit 21.

The normalization circuit 13 is, for example, as shown in FIG.
It is configured like. That is, the charging interval memory 1
The count value CN output from 2 is converted into an elapsed time by a division circuit 24 having the same configuration as the division circuit 20 and input to one input terminal of a comparison circuit 25. The other input terminal of the comparison circuit 25 is connected to a billing interval storage unit 26 in which a plurality of billing intervals preset at intervals of 0.5 seconds, such as 3.5, 4.0 and 4.5, are stored. Then, the elapsed time input to the comparison circuit 25 is compared with each charging interval stored in the charging interval storage unit 26,
The charging interval having the closest value is read from the charging interval storage unit 26 and sent to the multiplying circuit 14 as an accurate charging interval Tc.

The operation of the public telephone thus constructed will be described with reference to the time chart of FIG.

First, when a fixed number of coins are inserted into the coin insertion slot, the total value A of the inserted amounts is displayed on the display 6. After that, the telephone number of the telephone of the called party is input by dialing and the call signal c is transmitted from the in-office device 3 to the telephone of the called party. At time t0, when the handset of the telephone to be called is picked up and the hook switch d is activated, the telephone line 2 is switched and connected from the calling line to the telephone line. At the same time, the first charging pulse e transmitted from the in-office device 3 to the telephone of the calling party is input. The counter 9 to which the first charging pulse e at the time t0 is input to the set terminal S starts measuring the count value CN of the clock signal from the timer circuit 11 in the 0.1 second cycle. Then, the count value CN output from the counter 9 is converted into the elapsed time T after the start of the call by the division circuit 20 and input to the switching circuit 21.

Since the flip-flop 23 is not set only by the first charging pulse e, the switching circuit 21 inputs the elapsed time T from the division circuit 20 to the display 6.
Therefore, the elapsed time after the start of the call is displayed on the display 6.

Next, in the talking state, when the next charging pulse f is input at time t1, the flip-flop 10 is set and the count value CN of the counter 9 is reset to zero. At the same time, the next charging pulse f is applied to the set terminal S, so that the counter 9 starts measuring the count value CN after the input time t1 of the next charging pulse f. Therefore, the charging interval memory 12 stores the count value CN from the input time t0 of the first charging pulse e to the input time t1 of the next charging pulse f. Then, this count value CN is input to the normalization circuit 13, converted into an accurate charging interval Tc according to the procedure described above, and sent to the multiplication circuit 14.

On the other hand, the coin storing mechanism 5 in which a fixed number of coins have been inserted sends out the inserted amount A to the division circuit 16, so that the conversation frequency N corresponding to the inserted amount A is subtracted from the conversation frequency calculation circuit 18. Is input to. Therefore, the subtraction circuit 17 inputs the call frequency (N-1) after the input time t1 of the next charging pulse f into the multiplication circuit 14.
As a result, the callable time To after the input time t1 of the next charging pulse f is output from the multiplication circuit 14 and input to the subtraction circuit 19. The subtraction circuit 19 receives the count value CN of the counter 9 after the input time t1 of the next charging pulse f.
To the elapsed time T from the dividing circuit 20
Has been entered. Then, the division circuit 19 sends the remaining available time (To-T) after the input time t1 of the next charging pulse f to the switching circuit 21.

The flip-flop 23 is set at the time t1 since two pulses of the first charging pulse e and the second charging pulse f are input, and the flip-flop 23 is set to the switching circuit 21.
Is sent. As a result, the passable remaining time (To-T) from the subtraction circuit 19 is input to the display device 6. Note that the flip-flops 10 and 23, once set, are not reset until the call ends. Therefore, as shown in the figure, the display unit 6 displays the elapsed time after the start of the call from the time t0 to the time t1, and the remaining available time (To-T) after the time t1.

When an additional coin is inserted into the coin slot during a call, the call frequency calculation circuit 18 recalculates the call frequency N corresponding to the amount of money inserted up to that point. Therefore, the display unit 6 always displays the accurate remaining call time.

When the call ends and the handset is placed at time t6, the hook switch d is activated to disconnect the call line, and the counter 9, the contents stored in the charging interval memory 12, the flip-flops 10 and 23 are connected. Is reset. Therefore, the display content of the display 6 is also zero.

As described above, in the public telephone according to the embodiment of the present invention, the elapsed time after the start of the call is displayed on the display 6 from the input time of the first charging pulse e to the input time of the next charging pulse f. The remaining available time is displayed from the time when the next charging pulse f is input until the end of the call.

As described above, by distinguishing the type of time displayed on the display 6 before and after the input time t1 of the second charging pulse f, the following effects are produced. That is, for example, when a local telephone call is started by inserting a 10-yen coin corresponding to one call frequency into a public telephone, the display 6
The elapsed time from the call start time is displayed on. Since the local call charge is a well-known prescribed time such as 3 minutes per call frequency, the user can see the elapsed time,
You can easily grasp the remaining call time by mental calculation.

That is, by displaying the elapsed time from the start of the call until the second charging pulse f is input, the remaining time can be confirmed by the user making a local call, so that the user can enjoy the call with peace of mind. You can and are very convenient.

When a large number of coins are put in at one time to make a local call for a long time or a long distance call,
After the input time of the second charging pulse f, the remaining available call time corresponding to the amount of coins inserted and not yet used for a call is displayed on the display device 6. Therefore, since the user can make a call while always checking the remaining available time before hearing the reminder sound, the user can enjoy the call with peace of mind.

Further, since the normalization circuit 13 is used, it is possible to display the more accurate remaining call time.

That is, the time during which a call can be made with one call frequency is, for example, 3 minutes for a local call, and it varies depending on the distance for a long distance call, but the time is generally 0.
It is set every 5 seconds. Therefore, the charging interval measured by the counter 9 should also be 0.5 seconds. However, in reality, the average transmission interval of the charging pulse transmitted from the exchange to the public telephone is within the specified time, but each charging interval may fluctuate to some extent. If the line condition is bad, chattering or the like may occur in the receiving circuit 8 or the flip-flop 10 and the accurate charging time may not be detected. That is, the charging interval measured by the counter 9 may not be the 0.5 second interval but may take an intermediate value in the vicinity thereof. When the available call remaining time is calculated using such a charging interval, it may not match the actual remaining time.

Therefore, by using the normalization circuit 13, the charging interval having an intermediate value is corrected to the accurate charging interval Tc of 0.5 seconds. Therefore, the more accurate remaining call time is displayed.

Further, each circuit member constituting the above-mentioned display control section 7 can be manufactured at a low cost by using an IC or the like. Therefore, unlike the conventional public telephone, it is not necessary to provide the ROM memory for storing the area code and the billing interval corresponding to the area code, so that the service to the customer can be improved by adding a small cost.

Also, the place of installation of the public telephone is not particularly limited, and it is not necessary to change the set value even when the call charge is revised.

The present invention is not limited to the above embodiment. Each circuit configuration of the display control unit 7 may be configured using a microcomputer.

[0040]

As described above, according to the public telephone of the present invention, the counter elapses from the time when the first charging pulse is received to the time when the next charging pulse is received, and further, After the receipt of the next charging pulse, the elapsed time is calculated as it is. Therefore, the elapsed time can be displayed until the second charging pulse is received without using an expensive component member, and the remaining available call time can be accurately calculated and displayed thereafter, and the service to the user can be greatly improved. .

[Brief description of drawings]

FIG. 1 is a block diagram showing a schematic configuration of a public telephone according to an embodiment of the present invention;

FIG. 2 is a block diagram showing a display control unit of the telephone of the embodiment.

FIG. 3 is a block diagram showing a main part of the display control unit,

FIG. 4 is a time chart showing the operation of the telephone of the embodiment.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Communication part, 2 ... Telephone line, 3 ... In-station device, 5 ... Coin storage mechanism, 6 ... Display device, 7 ... Display control part, 8 ... Reception circuit, 9 ... Counter, 10, 23 ... Flip-flop, 1
1 ... Timer circuit, 12 ... Billing interval memory, 13 ... Normalization circuit, 14 ... Multiplication circuit, 15 ... Unit charge memory, 16 ...
Division circuit, 18 ... Call frequency calculation circuit, 19 ... Subtraction circuit,
21 ... Switching circuit, 22 ... Remaining time calculation circuit, 25 ... Comparison circuit, e ... First charging pulse, f ... Next charging pulse.

Claims (1)

[Scope of utility model registration request] 1. A counter for measuring an elapsed time from when the first charging pulse is received to when a next charging pulse is received, and a call elapsed time after the next charging pulse is received. 9), a billing interval memory (12) for storing the elapsed time from when the first billing pulse measured by the counter is received until when the next billing pulse is received, and an output from the billing interval memory (12) set in advance of the elapsed time that has been
A normalization circuit (13) that normalizes and outputs an accurate billing interval by comparing with the regular billing interval that is stored, and calculates the call frequency that can be called at that amount based on the amount information indicating the deposited amount Call frequency calculation circuit (18)
And the remaining call available from the call frequency output from the call frequency calculation circuit, the charging interval output from the normalization circuit, and the call elapsed time after receiving the next charging pulse output from the counter. Remaining time calculation circuit for calculating time (22)
And the next charging pulse after receiving the first charging pulse
Until the call is received, the elapsed time after the call is started is displayed.
After receiving the next billing pulse,
A public telephone equipped with a display (6) for displaying .