| 摘要 |
PURPOSE:To measure the shape of the surface of an object in a non-contact manner at a high speed by measuring a distance to an object with the irradiating of a light beam on the object while scanning it. CONSTITUTION:When irradiated on a scanner 2, lights from first and second light sources I1 and I2 modulated by frequencies f1 and f2 scan over an object 4 to be measured and the reflected beams are irradiated on a photo detector 6. Light currents i1 and i2 according to the position of the light spot of the reflected beams from the photo detector 6 are separated at respective frequencies 51 and 52 with filters 81 and 84. After computed with respective subtraction circuits 91 and 92, addition circuit 101 and 102 and division circuits 111 and 112, light currents i1 and i2 by light from a first light source I1 and light currents i1 and i2 by light from a second light source I2 are corrected linearly with linear correction circuits 121 and 122 and inputted into a displacement arithmetic device 13, where the displacement of the object is calculated and outputted. |
