WO1996016504A1

WO1996016504A1 - Disposable cordless portable telephone

Info

Publication number: WO1996016504A1
Application number: PCT/FR1995/001542
Authority: WO
Inventors: Didier Vary
Original assignee: Didier Vary
Priority date: 1994-11-22
Filing date: 1995-11-22
Publication date: 1996-05-30
Also published as: AU4263896A; FR2727270B1; FR2727270A1

Abstract

A cordless portable telephone including a memory for storing a count which initially corresponds to a predetermined number of telephone call units, a means for decrementing the count as the owner of the telephone makes calls, and a means for inhibiting calls once the count has been reduced to zero, so that the portable telephone can no longer be used.

Description

Disposable cordless portable phone

Technical area :

The present invention relates to cordless telephones and in particular to a portable cordless telephone used in a radiotelephone communication system.

STATE OF THE ART: The use of radiotelephones in a GSM type system is more and more widespread. In such a system, each subscriber has his portable cordless telephone which allows him to have telephone communications with other subscribers of the system regardless of where he is located.

With advances in electronic circuit technology, portable telephones have become miniaturized and have become truly "pocket" telephones. Unfortunately, because of the current cost in which, in addition to the price of communications, the purchase of the portable telephone, the radiotelephone is mainly used in a professional capacity and is not widespread in the public.

Statement of the invention;

This is why the object of the invention is to provide an inexpensive cordless portable telephone which can be discarded after a predetermined number of telephone calls.

The object of the invention is therefore a portable cordless telephone comprising a memory in which is stored an account originally corresponding to a predetermined number of telephone call units, a means of decreasing the account as and measure that the owner of the telephone makes telephone calls and a means of inhibiting telephone calls when the account reaches the value zero, so that the portable telephone can no longer be used.

Brief description of the figures: The aims, objects and characteristics of the invention will appear better on reading the following description made with reference to the drawings in which: FIG. 1 schematically represents a portable cordless telephone according to the present invention, and the FIG. 2 is a block diagram representing the arrangement of the various elements found in a portable cordless telephone illustrated in FIG. 1.

Detailed description of the figures: As illustrated in FIG. 1, the portable cordless telephone according to the present invention is mainly composed of a flat box 10 comprising a keyboard 12 identical to that of any telephone handset as well as an "on" button ( M) and a "stop" button (A). At the ends of the flat housing 10 there is a microphone 14 and a loudspeaker 16. The microphone 14 and the loudspeaker 16 are articulated so as to be able to fold over the flat housing 10 when the telephone is not in use. In this position, the microphone 14 and the loudspeaker 16 with a length equal to half that of the flat housing 10, come to be juxtaposed, and remain in this position thanks to a male element 20 which is fixed in a female element 22 .

The assembly thus formed is in the form of a parallelepiped with a length between 8 and 15 cm and a width of about 5 to 8 cm, which can therefore easily be placed in a jacket pocket.

In operation, the microphone 14 and the loudspeaker are in the open position as illustrated in FIG. 1, at an angle of approximately 135 * with the flat case 10 so that the loudspeaker 16 can be placed on the ear and microphone 14 in front of the mouth. We can also provide a mechanical lock (not shown) now The apparatus in this convenient position for making telephone communication. The telephone naturally includes an antenna 18 for transmitting and receiving radio waves modulated by the speech signals. Preferably, the antenna 18 is retractable and is deployed only when the telephone is placed in the operating position.

The telephone shown in FIG. 1 is made as simply as possible by a thermoforming process in which the plastic shell comprising the flat housing 10, the microphone 14 and the speaker 16 is molded in a single step around the electronic circuits. located in the housing 10, the microphone and the speaker. Consequently, once the telephone has been manufactured by this process, the circuits or the elements which it contains are no longer accessible. The telephone according to the invention is manufactured at the lowest cost by this method but is not repairable and must be discarded when its capacity for telephone calls is exhausted as will be seen in relation to FIG. 2. As illustrated in the FIG. 2, the electronic part of the telephone according to the invention comprises a microprocessor 30 essentially responsible for processing the signals received and to be transmitted over the antenna 18. For this, the microprocessor is connected to the reception part 32 which has the task of demodulating the digital signals to the microprocessor 30, and to the reception part 34 which has the task of modulating the signals transmitted by the portable telephone.

The signals received by the portable telephone are, after their conversion into analog signals by a converter 36, transmitted to the loudspeaker 16, via the AND gate 38. The signals which must be transmitted from the portable telephone come either from the keyboard 12 , or from the microphone 14. In the case where the signals come from the microphone 14, they are transmitted to a converter 40, via the AND gate 42, to be first converted into digital signals before processing by the microprocessor 30. The portable telephone obviously has a memory 44, connected to the microprocessor 30 by a bus 46, in which a predetermined number of telephone call units has been pre-recorded. With each call coming from the portable telephone by means of the keyboard 12, the microprocessor decrements the value found in memory according to the number of units which have been used. As long as this value is not zero, the microprocessor provides a bit 1 on lines 48 and 50, which makes AND gates 38 and 42 passable and therefore allows signals from the microphone to be transmitted on the antenna. 18, and to the signals received by the antenna from reaching the loudspeaker 16.

On the other hand, as soon as the microprocessor 30 detects that the number stored in memory reaches the value 0, it transmits a bit 0 on lines 48 and 50, which deactivates AND gates 38 and 42. Consequently, no signal received by the microphone 14 is not processed and no signal received by the antenna 18 can reach the loudspeaker 16. The portable telephone having exhausted its credit for telephone call units, it can then be discarded. Provision may be made for the user to be notified by a beep when the number stored in memory has reached a predetermined value, for example 5 units.

It should be noted that the number of call units stored in the memory 44 of the portable telephone according to the invention may be greater or less. Thus, the buyer can pay for his device more or less expensive depending on the size of the account stored in memory.

This portable telephone is intended to be used as portable radiotelephone in a network of the GSM type. Normally, the subscriber of such a network has an identification card or subscriber identity module (SIM) which, in addition to identifying the subscriber, allows the network to know what the service is. to which the subscriber is entitled, for example normal service (access to all services provided by the network) or limited service. In the case of the portable telephone according to the invention, the SIM identification card is not necessary since nothing will be billed to the subscriber insofar as he has previously paid the right to use a certain number of telephone call units when he purchased the device. It is however necessary that the device is recognized by the network, and therefore that the memory 44 contains in addition to the number of call units, an identification of the device as well as an identification of the authorized services. The information is transmitted over the network (to the base station) with each call from the portable telephone.

Although a portable telephone according to the invention is preferably used only to call another subscriber of the network, provision can be made for it to be able to receive calls from other subscribers. In this case, it is obviously necessary to provide the necessary circuits so that the device can be called regardless of where it is located, which makes it more complex.

The disposable portable telephone according to the invention obviously contains a battery (not shown) which supplies the energy necessary for its operation. In the case where the telephone can only be used for calls (that is to say the preferred embodiment), it is not necessary for this battery to be bulky since its capacity can be limited to the energy necessary for the emission of telephone calls as well as the operation in reception of the device during its lifetime (this second part of energy, difficult to determine, is much less important than that used for the emission). On the other hand, the battery must have a higher capacity, therefore be larger if the device is also used to receive calls from outside.

Modifications and improvements can be made to the portable telephone according to the invention without departing from the scope of said invention. Thus, it is wise to provide for an impossibility of being able to modify the value of the number of telephone call units stored in memory. This can be achieved by an auto-inhibition of the microprocessor as soon as an attempt to enter memory takes place, as is provided in certain smart cards.

Claims

1. Cordless portable telephone for communicating with subscribers of a radiotelephone communication network comprising a memory (44) in which a value corresponding to the origin corresponding to a predetermined number of telephone call units is stored, a means decrementing (30) said value as the owner of said telephone makes telephone calls and a means of inhibiting telephone calls when said value reaches zero, so that said portable telephone can no longer be used.

2. The portable telephone as claimed in claim 1, comprising a flat housing (10) on which is located a telephone keypad (12) intended for making telephone calls, and two articulated parts at each end of said housing respectively comprising a microphone (14) and a loudspeaker (16), said parts being folded over the housing so as to form with the latter a flat parallelepipedal assembly which can be easily placed in a pocket.

3. Portable telephone according to claim 1 or 2, comprising a microprocessor (30) responsible for processing the transmitted and received signals and comprising said means for decrementing said value of the number of calls stored in said memory, a means for detecting the zero value of said number and said means for inhibiting telephone calls.

4. A portable telephone according to claim 3, wherein said inhibiting means is an AND gate (42) whose activation by said microprocessor allows the transmission of telephone calls, deactivation of said AND gate by said inhibiting means preventing the transmission of any telephone call.

5. Portable telephone according to one of claims 1 to 4, further comprising an auto-inhibition means preventing any modification of said value of the number of telephone calls stored in said memory (44).

6. Portable telephone according to any one of the preceding claims manufactured in a single step by thermoforming so that it is impossible to access the interior.