| 摘要 |
The method is used to calibrate an apparatus for measuring an optical signal transmission path, in particular for detecting an object and/or for detecting a movement and/or a direction of movement of an object. In this case, the apparatus is provided with at least one measurement transmitter (H1,H2,H3) for transmitting an optical measurement signal, at least one compensation transmitter (K) for transmitting a compensation signal in phase opposition with the optical signal from the at least one measurement transmitter (H1,H2,H3), and at least one receiver (D) for alternately receiving the optical signal from the at least one measurement transmitter (H1,H2,H3) and the optical compensation signal from the at least one compensation transmitter (K). During the method, when the measurement transmitter (H1,H2,H3) is deactivated, the at least one compensation transmitter (K) transmits a compensation signal, while the at least one receiver (D) receives this compensation signal. The amplitude of the compensation signal is set in such a manner that an electrical measurement signal having an amplitude above the amplitude of signal noise produced by the at least one receiver (D) and/or a drive- and evaluation unit (17) is established. Furthermore, an offset signal which is in phase opposition with the compensation signal and is therefore in phase with the measurement transmission signal and has an amplitude equal to the amplitude of the signal caused by the compensation signal from the compensation transmitter (K) in the signal path downstream of the at least one receiver (D) is provided. |
