EP0503695A1 Expired / Lapsed EP ⏱️ 0.0 years remaining

System for accesssing a plurality of stations

Assignee: Delco Electronics LLC

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Filing: 1992-02-20

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Granted: —

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Expires: 2012-02-20

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Abstract

Abstract A system for unlocking any of several vehicles (10) by a passive electronic key (14) coupled to base units (12) in the vehicles (10) by a radio link uses short range LF transmission for signals to the key (14) and VHF transmission for signals to the base units (12). The key (14) has a ferrite antenna (38) connected to a receiver (36) comprising a comparator. When an operator pulls the door handle, codes stored in the base unit (12) are transmitted to identify any authorized key (14) within the range. The key (14) has a memory (50) partitioned into separate blocks for different base units (12) and another block for a scratchpad memory. A state machine (44) stores the block addresses and controls access to the blocks (50) according to the transmitted codes. When a block is accessed, a secure ID in the block is sent to the base unit (12) to verify that the key (14) is authorized to unlock the vehicle (10). The ID can be updated upon command from the base unit (12) using the same codes to assure that an authorized unit is receiving the new ID. The new ID is written to the scratchpad, verified for correctness, and the scratchpad address is exchanged for the address of the block containing the old ID. Auxiliary data specific to the vehicle (10) or to the user of the electronic key (14) may also be stored in the memory blocks (50) and retrieved along with the ID.

Inventors

👤 Sachal Bhagwan Gidwani
👤 Eric Lee Slone
👤 Kenneth Ray Campbell

Bibliographic Details

Application Number —

Jurisdiction EP

Data Source google_patents

Last Synchronized 2026-11-09 23:15

CPC Classifications

H; H04; H04B; H04B1/00; H04B1/38; H04B1/40; G; G07; G07C; G07C9/00; G07C9/00174; G07C9/00309; G07C2009/00365; G07C2009/0038; G07C2009/00753; G07C2009/00769; G07C2009/00793

Claims Analysis

Total Claims: 5

Claim 1

Independent Claim 235 words

A system for accessing a plurality of base stations comprising a plurality of base units (12) each associated with a respective base station (10) and adapted to control one or more functions of its respective base station, each base unit being adapted to store therein a unique base unit number and an identification code for use in granting access to the or each function associated with its respective base station, and at least one remote unit (14) adapted to communicate with the base units (12); each remote unit comprising a memory (50) partitioned into assigned memory blocks each associated with a respective base unit and containing an identification code and a temporary memory block, processing means (44) adapted to assign a base unit number to each memory block equivalent to the base unit number of its respective base unit and, on communication of a base unit number to the remote unit, to obtain from the corresponding memory block the identification code stored therein for transmission to the base unit; each base unit comprising updating means (24) adapted to update its identification code by storing a new identification code in a memory thereof and by transferring the new identification code to the temporary memory block of said remote unit, the processing means (44) being effective when updating the identification code of a base unit to relate the corresponding base unit number to the new identification code.

Claim 2

Dependent Claim 39 words

A system according to claim 1, wherein the processing means (44) of each remote unit is adapted when updating an identification code to reassign the corresponding base unit number to the memory block thereof containing the new identification code.

Claim 3

Dependent Claim 27 words

A system according to claim 2, wherein the processing means (44) is adapted to assign the memory block formerly containing the identification code the temporary memory block.

Claim 4

Dependent Claim 90 words

A system according to claim 1, 2 or 3, wherein the processing means (44) is adapted to be kept in a substantially non-active state for energy conservation, each remote unit including a register (42) containing an activating code and activating means (44) operable to activate the processing means when a code matching the activating code is received by the remote unit; each base unit comprising means (24) to store the activating code or codes of the remote units and to transmit the activating code or codes to each remote unit.

Claim 5

Independent Claim 37 words

A system according to any preceding claim, wherein one or more of the base stations is a vehicle and the function or functions adapted to be controlled by the respective base unit is access to the vehicle.

References Cited (Backward Citations)

DE2729062C3 Cited

DE3031405A1 Cited

EP0068437B1 Cited

EP0077101B1 Cited

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