Code reader
AssigneeEmhart Industries, Inc.
InventorGary E. Lavelle
Life of this patent
Estimating the term…
Abstract
A reliable electronic lock comprises means for reading a key card upon insertion and withdrawal. Sets of data read from the key card are compared to CRC data read from the key card to determine which set contains actual data and no false data erroneously read by the electronic lock. The CRC data is stored in scrambled form on the card to minimize the possibility of match to a set of actual and false data.
Claims20
In an electronic locking apparatus having means for reading a set of actual data from a key card, the improvement comprising:
- memory means coupled to the reading means for storing said set of actual data and also storing false data erroneously read by said reading means,
- means for shifting through said memory means to the locations of a plurality of sets of said actual and false data, a first one of said sets including both said actual data and false data and a second one of said sets including said actual data and none of said false data,
- processing means coupled to the shifting means for determining that said first set contains some of said false data and said second set contains said actual data and none of said false data, and
- means coupled to said processing means for comparing said actual data within said second set to a lock combination stored within said locking apparatus and operating said locking apparatus if the comparison is favorable.
A key card for a locking system having means for reading a first set of actual data contained on said key card and a second set of validity data contained on said key card, means for storing said first set of actual data read by the reading means and means for comparing said first set of actual data to said second set of validity data to determine if said first set of actual data is valid, said key card comprising:
- at least one magnetic track containing said first set of actual data and said second set of validity data in linear form, said first set of actual data including a lock access combination and said second set of validity data including cyclical redundancy checking bits, and said second set of validity data being stored on said at least one magnetic strip in a predetermined order which is not the normal order.
A process for encoding a key card with lock combination data for a locking system having a key card reader, means for reading said key card and means for comparing said lock combination data read from said key card to a lock combination stored in said locking apparatus, said key card having at least one magnetic track, said process comprising the steps of:
- calculating from said lock combination data a corresponding set of cyclical redundancy checking bits,
- reordering said cyclical redundancy checking bits in a predetermined order which is not the normal order of said bits;
- and
- writing the reordered set of cyclical redundancy checking bits on said at least one magnetic track on said key card along with said lock combination data.
In an electronic locking apparatus having means for receiving a key card, processor means for comparing lock combination data read from said key card to at least one lock combination stored in said locking apparatus, and means responsive to correspondence between said lock combination data on said key card and said lock combination stored in said locking apparatus for operating the locking apparatus, the improvement comprising:
- means coupled to the processor means for reading said lock combination data on said key card during insertion of said key card into said means for receiving;
- said processor means includes means for determining when said lock combination data on said key card is read successfully during insertion, based on data read during insertion;
- means coupled to the processor means for reading said lock combination data on said key card during withdrawal of said key card from said means for receiving;
- and
- said processor means further includes:
- means for determining when said lock combination data on said key card is read successfully during withdrawal, based on data read during withdrawal and independent of said data read during insertion;
- and
- means for activating the lock operating means when said lock combination data on said key card has been read successfully either upon insertion or independently upon withdrawal and said successfully read data corresponds to said lock combination stored in said locking apparatus.
Dependencies are inferred from the claim text.