Passive rfid detector in mobile phones to prevent loss of items
From PDI
Contents |
Introduction
People often carry with them small items which are valuable or which if lost will cause them inconvenience. These items include keys, credit cards, usb flash drives. This idea concerns a method to prevent the loss of such items.
Prior Art
There is a category of devices known as passive radio frequency ID tags (RFID tags). These are small tags measuring in the order of several millimetres square and with a thickness of several micrometres which can be detected using a RFID detector. Each RFID tag has a unique signature. These tags are used in several different ways which can be shown by example:
Often in libraries the tags are sewn into the binding of books. When a customer is leaving the library they pass through an area containing an RFID detector, and, if the customer has in their possession a book which has not been checked out properly the detector will detect this and sound an alarm.
When a warehouse receives a delivery an RFID tag is attached to the pallet containing the stock delivered. During stocktaking an employee using a hand-held RFID detector can move through the warehouse and quickly record the location of all the pallets by the RFID detector recognising the unique ID of the pallet's tag.
The current cost of an RFID tag is approximately €0.10
Invention
The idea is to build a portable RFID detector. This may either be a standalone device or build into a mobile phone or other portable electronic device such as a PDA.
The items to be protected from loss should each have a passive RFID tag attached to them.
The passive RFID tag attached to each of the items should be registered to the RFID detector.
The detector will at frequent intervals scan for the signatures of all the tags which have been registered to it. In the event of it being unable to detect one or more tags it will sound an alarm.
Example
1) A passive RFID detector is built into a mobile phone.
2) the owner of this phone attaches a passive RFID tag to their USB flash drive. They then register this tag with their mobile phone by holding the tag close to the phone and pressing a key or combination of keys on the phone.
3) The owner visits an Internet cafe while carrying the phone and the USB drive, and they attach the USB drive to one of the computers.
4) The person gets up to leave the computer forgetting their USB drive.
5) The phone scans for the RFID tag of the drive and all other tags registered to it every second. When the USB drive's tag is out of range (say 3 metres) for more than 1 second the phone will emit a beep, or will vibrate, or in some other way notify the owner.
This will also protect the phone from being lost since of the owner has any passive RFID tags on their person and leaves their phone behind the phone will sound an alarm as soon as the owner is out of range.
