The attitude control device of the job instrument for the job object surface the measuring device and paint device null of the crucible which possesses

摘要

PURPOSE: To accurately measure the thickness of a transparent layer without any contact with the internal surface of a crucible by emitting three parallel light beams incident on a work object plane at three positions not arrayed along a straight line, and concurrently photographing reflected light therefrom. ;CONSTITUTION: Mirror members 11 to 13 are arranged on the optical axes of laser beam sources 8, 9 and 10, so as to totally reflect laser beams L₁ to L₃ emitted therefrom along directions inclined by the preset angles ₁ to ₃. The mirror member 11 refracts the laser beam L₁ emitted from the beam source 8a within a plane C₁ parallel to the axial line 7a of a CCD camera 7. Also, the mirror member 12 refracts the laser beam L₂ emitted from the beam source 9. Furthermore, the mirror member 13 refracts the laser beam L.₂. According to this construction, when a measurement head 3 is accurately positioned at the prescribed measurement point, the axial line 7a is kept aligned with a line normal to the internal surface 2a of a crucible 2 as a measurement object, and the laser beams L₁ to L₃ are made incident on three positions forming the apexes of a right angled triangle. Reflected light therefrom is, then, photographed with the camera 7.;COPYRIGHT: (C)1996,JPO