Transponder chip providing 2-way data communication with the read-write laser of available CD-RW drives, is for use in password protection and authentication, so that an additional security read- write device is not required

摘要

A transponder is embedded in the surface of the compact disk with a photo-diode structure in the surface of the chip which can interpret the modulation of the sequential scanning laser beam. The transmitter, which can be a LCD, forms a reflecting area in the middle of the receiver. Coils embedded in the CD cut the interference magnetic field of the CD drive and supply energy to the chip. Read and write paths to the chip are different.