| 摘要 |
PURPOSE:To correct local deformation and make optical elements highly precise by forming a given form error on a function face of each optical element, dividing the function face into a plurality of regions, approximating the form errors in terms of a function so that each region is continued and machining a cavity face on the basis of the function so that the form errors are offset. CONSTITUTION:It is so designed that a given form error is stably formed on an optical function face of each of optical elements, and the optical function face is divided into a plurality of regions to approximate the form errors in terms of a function so that the boundary of each region is continued. Molding is performed by machining a cavity face so that the form errors are offset. That is, the cavity face is made by deviating it by -E1 with respect to the extent of E1 in a position in the direction y1 of each latitudinal line 34 of a lens 30. In the case of (i=1 to n), approximate functions of respective m-th degrees are found and, in the boundary of the region, derivated functions up to the (m-1)the degrees of the respective functions which hold the boundary therebetween are allowed to coincide with each other. Further, the position of the latitudinal line 34 and the radial change rate of a longitudinal line 35 are approximated in relation to each other over the whole region of the latitudinal lines. Thus, data for correcting molding are prepared. |
