Telecommunications – Transmitter and receiver at same station – Radiotelephone equipment detail
Reexamination Certificate
1997-12-18
2001-11-06
Eisenzopf, Reinhard J. (Department: 2745)
Telecommunications
Transmitter and receiver at same station
Radiotelephone equipment detail
C455S572000, C455S117000, C455S127500, C455S343200, C340S661000, C340S660000, C320S152000, C320S162000
Reexamination Certificate
active
06314307
ABSTRACT:
BACKGROUND OF THE INVENTION
The invention relates to an electronic apparatus whose power is supplied by a supply voltage, comprising a memory which contains electrically erasable data and a supply voltage detection device for detecting a variation of the supply voltage.
In heavily industrialized countries, a current tendency seeks to miniaturize the dimensions of portable telecommunication equipment intended for the public at large and for current use. The makers of this electronic equipment are thus exposed to heavy competition regarding the weight-to-volume ratio and the range of their apparatus. As the latest integrated circuit technologies currently permit of considerably reducing the volume of the electronic circuits, the range of this portable apparatus has become the factor which restricts this course to miniaturization. Indeed, generally intended for mobile use, this apparatus is fed by power supply batteries whose range is proportional to the weight in a given technology. In consequence, an apparatus fed by a battery is all the lighter as its range is smaller, which explains why the battery of a portable apparatus frequently turns out to be discharged.
Thus, to avoid certain phenomena which are likely to damage the apparatus, it is very important to anticipate during the discharging the instant at which the supply voltage will be cut off. Notably, the mobile radio telephones or other equipment comprising processors and electrically erasable memories of the EEPROM type (Electrically Erasable Programmable Read-only Memory) cannot withstand sudden power cuts. If the power supply is not cut off until its voltage drops below a threshold defined as critical by the manufacturer, the contents of the EEPROMs may be corrupted. In effect, the processor powered by an insufficient voltage no longer controls its addressing system. It runs the risk of writing an erroneous address in the EEPROM and overwriting the data which are found at that address. Data may then be lost, which is very harmful to the use of the radio telephone.
In a known electronic apparatus, a supply voltage detection device is used to periodically sound the supply voltage produced by the battery in order to detect the instant at which said voltage drops below the critical voltage and cut off the power supply so as not to change the data of the EEPROM.
An apparatus comprising such a supply voltage detection device, however, thus has a major drawback that questions its reliability. In effect, based on a periodic sounding technique, the detection precision and thus the reliability of this device directly depend on the sounding period used. As the conventional discharging curve of a battery drops very rapidly towards the end of the discharge, the power supply is frequently cut off which is undetected by the current device of which the sounding period is very large compared to the rapidity with which the voltage drops at the end of the discharge.
Diminishing the sounding period for enhancing the chances to detect the crossing of the critical threshold forms a too expensive solution which necessitates a faster and more powerful processor than that used in the known device.
SUMMARY OF THE INVENTION
The present invention describes a simple and economic solution for largely remedying these drawbacks. The invention notably has for its object to provide a supply power detection device which is more reliable than the known device for detecting the supply voltage, without notably augmenting the complexity of the electronic circuits used. The device according to the invention is furthermore capable of instantaneously detecting the crossing of a voltage threshold defined as critical for cutting off the power supply of the apparatus so as not to change the digital data stored in the EEPROM memory.
Therefore, an apparatus of the type defined in the opening paragraph is characterized in that the detection device for detecting the supply voltage comprises:
a continuous monitoring device for the supply voltage for forming a first signal which indicates a drop of supply voltage,
backup means for backing up the data of the memory when said signal appears.
This continuous monitoring device for the supply voltage has the advantage of using the processor only when the supply voltage crosses a fixed threshold. Said processor is thus available for carrying out other operations, notably for managing the communication between the mobile station and the base station in the case of a radio telephone.
A first characteristic feature of the invention according to which an electronic apparatus of the type defined above comprises a supply voltage detection device characterized in that the continuous monitoring device produces a second signal for indicating a supply voltage level provides the advantage of permitting the user to control the charging level of his battery to anticipate the instant at which the battery needs recharging.
A second characteristic feature of the invention according to which the supply voltage detection device characterized in that the continuous monitoring device produces a third signal to indicate an overload provides the additional advantage of preventing the battery from exploding as a result of a power supply being cut off when the third signal appears.
According to another interesting characteristic feature of the invention, an electronic apparatus of the type already mentioned additionally comprising a control element which has at least one interrupt input is characterized in that said signals described above are applied to said interrupt input for respectively generating an interruption of the control element and for triggering an interrupt program in response to said signals.
According to again another characteristic feature of the invention, an electronic apparatus is provided of the type already defined above, characterized in that the continuous monitoring device additionally comprises a comparing device for comparing the value of the supply voltage to set values and to produce said respective signals. This characteristic feature provides a means for defining detection thresholds as a function of the type of battery used, on the one hand, and of the needs of the user on the other hand.
These and other aspects of the invention will be apparent from and elucidated with reference to the embodiments described hereinafter.
REFERENCES:
patent: 3650345 (1972-03-01), Yardney
patent: 4460870 (1984-07-01), Finger
patent: 4740754 (1988-04-01), Finger
patent: 4910761 (1990-03-01), Shimura et al.
patent: 4962543 (1990-10-01), Kuge et al.
patent: 5027285 (1991-06-01), McCartney et al.
patent: 5168205 (1992-12-01), Kan et al.
patent: 5426690 (1995-06-01), Hikuma et al.
patent: 5550475 (1996-08-01), Shafer
patent: 5600229 (1997-02-01), Oh
patent: 5622789 (1997-04-01), Young
patent: 5677944 (1997-10-01), Yamamoto et al.
patent: 5724651 (1998-03-01), Tekahashi et al.
patent: 5726636 (1998-03-01), Hayes, Jr.
patent: 5797088 (1998-08-01), Stamegna
patent: 5898930 (1999-04-01), Terashima et al.
patent: 5923150 (1999-07-01), Umetsu
Dicran Halajian
Eisenzopf Reinhard J.
Ramos-Feliciano Eliseo
U.S. Philips Corporation
LandOfFree
Portable electronic apparatus having a detection device for... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Portable electronic apparatus having a detection device for..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Portable electronic apparatus having a detection device for... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2606349