Study on Method for Manufacturing Thin Schmidt Corrector

Since the thin glass has poor rigidity and it is easy to deform in lapping,this paper puts forward a new method to reduce deformation.Taking the fabrication of thin Schmidt corrector,for example,technicians adopt the traditional surface adhesive method to fix the workpiece in lapping.Before the workpiece is taken off from the fixture,the surface accuracy is quite good.It can meet the requirement.But after being taken down from the fixture,the workpiece deforms,and its surface accuracy is reduced and could not meet the requirement.We adopt vacuum-mould method to fix the workpiece,which brings the workpiece deformation in expectant absorption and changes the process from machining aspheric surface to machining plane surface and removes workpiece deformation in adhering because of temperature change.Therefore the surface accuracy can be controlled easily and the difficulty of the machining process is reduced.In lapping we also try to reduce asymmetrical pressure on the workpiece,that reduces workpiece deformation in lapping and makes workpiece surface accurate.Thus workpiece surface accuracy is assured and the requirement is met.