| 摘要 |
PCT No. PCT/EP89/01390 Sec. 371 Date Jun. 21, 1991 Sec. 102(e) Date Jun. 21, 1991 PCT Filed Nov. 17, 1988 PCT Pub. No. WO90/05977 PCT Pub. Date May 31, 1990.A circuit arrangement for detecting and recognizing the type of optical recording medium being scanned, in which a high pass filter is connected in series with a rectifier. The high pass filter receives a data signal containing information stored in the recording medium. A low pass filter has an input which receives also the data signal. The first input of a comparator is connected to the output of the rectifier, whereas the rectifier has an input connected to the output of the high pass filter. A second input of the comparator is connected to an output of the low pass filter, and a controls processor is connected to an output of the comparator. A second comparator may be provided with a first input connected to the output of the rectifier, whereas the second input of the second comparator is connected to a reference voltage. The output of this second comparator is also connected to the controls processor which recognizes the type of recording medium being scanned from the outputs of the comparators.
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