Patent ID: 6563882
Filing Date: 2003-05-13
Classification: G06K

Abstract:
A write/read device (1) designed for the contactless communication with at least one transponder and comprising data supply means (2) for supplying at least one data block (DB) and including first coding means (4), by which first coding means (4) a data block (DB) supplied by the data supply means (2) and applied to said first coding means (4) can be coded in accordance with a first coding method and by which, as a result of the coding in accordance with this first coding method, at the most a given number N of coding signals (KI) representing a data block (DB) can be generated and supplied, and including carrier signal generating means (5) for generating a carrier signal (TS) and including modulation means (6), to which modulation means (6) the carrier signal (TS) and the coding signals (KI) can be applied and by which modulation means (6) the carrier signal (TS) can be modulated in accordance with the coding signals (KI) so as to generate and supply a modulated carrier signal (TSM) corresponding to the number of coding signals (KI) and having the same number of modulation steps, and including transmission means (7), to which transmission means (7) the modulated carrier signal (TSM) can be applied in order to be transmitted to at least one transponder, characterized in that there have been provided second coding means (9), by which second coding means (9) a data block (DB) supplied by the data supply means (2) and applied to said second coding means (9) can be coded in accordance with a second coding method and by which second coding means (9), as a result of coding in accordance with said second coding method, at the most a given number M of coding signals representing a data block (DB) can be generated and supplied, the number M being smaller than the number N, andthere have been provided selection means (10), with the aid of which selection means (10) it is possible to select that the coding signals (KI) representing a data block (DB) and supplied by the first coding means (4) or that the coding signals (KI) representing a data block (DB) and supplied by the second coding means (9) can be applied to the amplitude modulation means (6).