| 摘要 |
Various techniques are disclosed for detection systems and methods to detect an object or a recess present on a surface. For example, a detection system includes a laser light source configure to emit a laser beam, a deflector configured to deflect the laser beam by a deflection angle, a modulator configured to modulate the laser beam with a modulation frequency, a control unit configured to control the deflector and the modulator to vary the deflection angle in conjunction with the modulation frequency as a function of time according to a scanning sequence, a memory configured to store the scanning sequence and reference modulation frequencies for corresponding reference times, an optical sensor configured to detect a reflected laser beam, and a signal processor to extract and compare measured modulation frequencies of the detected reflected laser beam with reference modulation frequencies to detect an object or a recess on a surface. |
