Method for reduction of the power consumption of a mobile data memory; application of the method to an identification system with at least one read/write device and a mobile data memory

• US 20070111671A1
• Filed: 07/28/2004
• Published: 05/17/2007
• Est. Priority Date: 07/28/2003
• Status: Active Grant

• Current Assignee: Siemens AG
• Original Assignee: Siemens AG
• Inventors: Baumgartner, Josef, GIla, Janos
• Granted Patent: US 7,693,504 B2
• Time in Patent Office: Days
• US Class Current: 455/69
• CPC Class Codes: G06K 19/0705 the battery being connected to a power saving arrangement
• CPC Class Codes: G06K 19/0723 the record carrier comprising an arrangement for non-contact communication, e.g. wireless communication circuits on transponder cards, non-contact smart cards or RFIDs
• CPC Class Codes: G06K 7/0008 General problems related to the reading of electronic memory record carriers, independent of its reading method, e.g. power transfer

Abstract

The invention relates to a method for reduction of the power consumption of a mobile data memory with a non-contact data transmission by means of a read/write device. According to the invention, the mobile data memory, containing at least one energy store and user, is supplied, at least during a cyclic inactive idle mode, with a first clock frequency from a first oscillator and, for data receipt at least during a cyclic request time, with a second higher clock frequency from a second oscillator. The second clock frequency is determined above all for data modulation of a received signal, obtained from the reception antenna or from a combined transmission/reception antenna on the mobile data memory. The invention further relates to a mobile data memory and an identification system with at least one read/write device and one mobile data memory. The advantage of requiring no battery exchange during the life of the mobile data memory is thus conferred.

Claims

1-19. -19. (canceled)

20. A method for reducing the power consumption of a mobile data memory for contactless data transmission with a read/write device, comprising:

providing at least one energy store and energy consuming components for the mobile data memory;

supplying the mobile data memory during a cycle inactive idle mode;

supplying a first clock frequency from a first oscillator; and

supplying a second, higher clock frequency from a second oscillator for data reception during a cyclic polling time.

21. The method according to claim 20, wherein the higher clock frequency is used for data demodulation of a received signal.

22. The method according to claim 21, wherein a level of the received signal is measured within the cyclic polling time and the received signal is then data demodulated if a minimum level is present.

23. The method according to claim 22, wherein the second clock frequency is switched off again if a minimum level is not present.

24. The method according to claim 21, wherein the data demodulation of the received signal is ended if the demodulated read data is invalid.

25. The method according to claim 24, wherein the second clock frequency is switched off again if invalid read data is present.

26. The method according to claim 21, wherein at the start of the polling time and prior to the data demodulation of the received signal and the second clock frequency is switched with an initial transient time.

27. The method according to claim 20, wherein the second clock frequency is a multiple of the first clock frequency.

28. The method according to claim 27, wherein the second clock frequency is 40 times the first clock frequency.

29. The method according to claim 20,the first clock frequency (f1) is used for transmission of the data (SDAT).

30. The method according to claim 21, wherein the method is used in an identification system based on the ISO/IEC 18000 standard for operation in an ISM frequency band.

31. The method according to claim 30, wherein the identification system is operated in an ISM frequency band of 2.45 GHz.

32. A mobile data memory for transmitting data to a read/write device, comprising:

an antenna;

a data receiver and a data transmitter connected to the antenna;

an energy store for supplying energy;

a first oscillator with a first clock frequency for a timer for the data transmitter;

a second oscillator with a second higher clock frequency for the data receiver; and

a control unit that intermittently connects a plurality of circuit parts of the data memory to the energy store and during a cyclic polling time connects the second oscillator to the energy store.

33. The mobile data memory according to claim 32, wherein the data receiver includes a data demodulator for data demodulation of a received signal from the antenna and the data demodulator is connectable from the control unit to the energy store.

34. The mobile data memory according to claim 33, wherein the data receiver includes a level detector for measuring the level of the received signal, which level detector is connectable from the control unit to the energy store.

35. The mobile data memory according to claim 32, further comprising electronic switching devices that are activated by the control unit.

36. The mobile data memory according to claim 32, further comprising a timer.

37. The mobile data memory according to claim 32, wherein the first and second oscillators are quartz oscillators.

38. An identification system having a read/write device, comprising:

a mobile data memory, comprising;

an antenna;

a data receiver and a data transmitter connected to the antenna;

an energy store for supplying energy;

a first oscillator with a first clock frequency for a timer for the data transmitter;

a second oscillator with a second higher clock frequency for the data receiver; and

a control unit that intermittently connects a plurality of circuit parts of the data memory to the energy store and during a cyclic polling time connects the second oscillator to the energy store.