US 7,598,872 B2 · Method for recognizing identification media

Abstract

The invention relates to a method for recognizing identification media in the communication area of a write/read device functioning according to the principle of inductive coupling in the MHz range, wherein an antenna is used for transmitting and receiving HF signals, in addition to a circuit for transmitting HF signals with a standard transmitter power output and a logic circuit for evaluating communication between a write/read device and an identification medium. A short inquiry signal consisting of several fundamental components of the HF field and having a standard transmission power output is periodically transmitted via a transmission path and the antenna and a response signal is detected on the antenna. The response signal is compared to a reference signal and a communication signal is transmitted in order to recognize an identification medium in the event that the response signal is different from the reference signal. This enables energy-saving, reliable recognition of identification media occurring in the field of communications for subsequent communication with the write/read device, particularly with respect to battery-operated write/read devices.

Claims22

Dependent claims

A method for detecting identification media within a communication range of an antenna for transmitting and receiving RF signals of a read/write unit which operates in accordance with the principle of inductive coupling of an RF field in the MHz frequency band and which has a transmitting path connected directly to the antenna,

a receiving path connected directly to the antenna,
a circuit for RF communication with at least one of a standard transmitting power or reduced transmitting power, and a logical circuit for evaluating a communication between the read/write unit and an identification medium, wherein
a short polling signal, which contains at least one of unmodulated or force excited oscillations of the RF field, is periodically emitted with the standard transmitting power via the transmitting path and the antenna,
that during the emission of the polling signal, a return signal with at least one of unmodulated or force excited oscillations of the RF field is detected at the antenna,
then the return signal is compared with a reference signal,
and then a communication signal is emitted for detecting an identification medium if the return signal differs from the reference signal.

3 more elements

Dependencies are inferred from the claim text.

Method for recognizing identification media

Life of this patent

Method for recognizing identification media

Life of this patent

Abstract

Claims22