Method for keyless unlocking of an access door to a closed space
First Claim
1. Method for keyless unlocking an access door to a closed space, in particular a motor vehicle, by means of an electronic system, comprising on the one hand a control device (12) for an electronic lock (14) for said door fitted with a first data management electronic unit (20) associated to first low frequency signal transmission means (24, 25) and to first high frequency signal reception means (22, 23) and on the other hand at least one portable transponder (16) comprising a second data management electronic unit (36) associated to second reception means (38, 39) for said low frequency signals and to second transmission means (40, 41) for said high frequency signals, said method comprising sending an interrogation signal to at least one transponder via said first transmission means and, in response, sending an identification signal via said at least one transponder to control said electronic lock, said first transmission means of said control device being activated by a signal sent by said second transmission means of said at least one transponder, characterized in that, in a preliminary operating mode of said system wherein said first transmission means are inactive, said second transmission means periodically transmits a high frequency signal for activating said first transmission means.
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Accused Products
Abstract
The invention relates to a method for keyless unlocking of an access door to a closed space, in particular a motor vehicle, which is carried out by means of an electronic system, comprising a control module for an electronic lock, associated with the said door and a portable transponder for authorised users. The method comprises sending an interrogation signal at low frequency from the control module to the transponders and also the exchange of data at high frequency. The control module has reception means for the above which are at least continuously in a listening mode. Said method is characterised in that the low frequency transmitters are inactive in a preliminary functional mode, the high frequency transmission means in the transponder periodically emits an activation signal for said transmission means in order that the above are only activated during limited periods, which ensures the reception of an interrogation signal for a transponder entering the low frequency communication region.
16 Citations
10 Claims
- 1. Method for keyless unlocking an access door to a closed space, in particular a motor vehicle, by means of an electronic system, comprising on the one hand a control device (12) for an electronic lock (14) for said door fitted with a first data management electronic unit (20) associated to first low frequency signal transmission means (24, 25) and to first high frequency signal reception means (22, 23) and on the other hand at least one portable transponder (16) comprising a second data management electronic unit (36) associated to second reception means (38, 39) for said low frequency signals and to second transmission means (40, 41) for said high frequency signals, said method comprising sending an interrogation signal to at least one transponder via said first transmission means and, in response, sending an identification signal via said at least one transponder to control said electronic lock, said first transmission means of said control device being activated by a signal sent by said second transmission means of said at least one transponder, characterized in that, in a preliminary operating mode of said system wherein said first transmission means are inactive, said second transmission means periodically transmits a high frequency signal for activating said first transmission means.
Specification