| 摘要 |
<p>PROBLEM TO BE SOLVED: To reliably grind to thin a plate-like work to a desired finished thickness regardless of a kind or a thickness of the plate-like work by measuring the thickness of the plate-like work until the thickness thereof reaches to the desired finished thickness.SOLUTION: A light emitter included in a measuring part 61 emits laser light in a -X direction. A semitransparent mirror 62 partially reflects the laser light emitted by the light emitter in a -Z direction. A mirror 63 reflects the laser light emitted by the light emitter and passing through the semitransparent mirror 62 in the -Z direction. Calculation means obtains a thickness of a plate-like work 30 by calculating a difference between a difference, which is obtained by deducting a distance between the light emitter and the semitransparent mirror 62 from a distance calculated by the calculation unit on the basis of the laser light reflected by the semitransparent mirror 62 to be directed to and be reflected on a holding surface 131 of a chuck table 13, and a distance, which is obtained by deducting a distance between the light emitter and the semitransparent mirror 62 from a distance calculated by the calculation unit on the basis of the laser light reflected by the mirror 63 to be directed to and be reflected on an upper surface 31 of the plate-like work 30.</p> |
