| 摘要 |
<p>A laser displacement measurement system (10) including a radiation source (12) for transmitting radiation to a target (16), an R.F. transmitter oscillator (18) for modulating the amplitude of the radiation at a first frequency, a detector (24) for sensing the radiation reflected from target (16), an R.F. local oscillator (28) for providing an R.F. signal at a second frequency, a first mixer circuit (34), responsive to the oscillators for providing a local I.F. signal which is the difference between the first and second frequencies, a second mixer circuit (44), responsive to detector (24) and R.F. local oscillator (28), for providing a reflected I.F. signal which is the difference between the second frequency and the modulated frequency of the reflected radiation, and a phase detector (48), responsive to the local and reflected I.F. signals, for detecting a first phase difference between the signals representative of the distance of target (16).</p> |
