Patent ID: 7150674

Claim:
A both-side grinding method for thin disc work in which the thin disc work is rotationally supported and a pair of grinding wheels rotating at a high speed are fed in the axial direction of its grinding wheel spindle in order to simultaneously grind both surface and back sides of the work by grinding surfaces of the grinding wheels, comprising the steps of: rotationally supporting the work by a work supporting means in a state such that the work is between the grinding surfaces of the paired grinding wheels and the surface and back of the work are opposed to the grinding surfaces; measuring distances from a predetermined position to the surface and back of the work at three points at least by using a non-contact type distance sensor when the feeding operation of the grinding wheels is completed; detecting the amount of deformation of the work from the results of measurement at the three points at least; and in case the calculated amount of deformation exceeds a specified value, making moving adjustment of the grinding wheels in accordance with the amount of deformation so that the work is flat without deformation when the feeding operation of the grinding wheels is completed, wherein the work supporting means comprises a hydrostatic supporting means which supports the surface and back of the work with hydrostatic fluid in a non-contact state, and wherein the hydrostatic supporting means is provided with the at least three non-contact type distance sensors measuring the distances at the at least three points.