REFRACTIVE INDEX MEASURING METHOD FOR PLASTIC LENS WITH CURVATURE

PURPOSE: A method for measuring a shape and a refractive index of a curvature-shaped plastic lens is provided to measure refractive indexes of several portions by using a digital holography microscope when shapes of the portions are known. CONSTITUTION: A method for measuring a shape and a refractive index of a curvature-shaped plastic lens comprises the steps of: measuring a refractive index of a portion of the plastic lens (ST100); defining the measured refractive index as an average refractive index of the plastic lens and preparing refractive index matching oil which is matched with the average refractive index (ST200); obtaining a first phase contrast phase by using a transmission-type digital holography microscope after putting the refractive index matching oil into a predetermined transparent container (ST300); obtaining a second phase contrast phase by using the transmission-type digital holography microscope after dipping the plastic lens into the refractive index matching oil contained in the transparent container (ST400); and subtracting the first phase contrast phase from the second phase contrast phase (ST500). [Reference numerals] (ST100) Measure an average refractive index; (ST200) Prepare oil of an average refractive index; (ST300) Obtain a contrast phase of refractive index matching oil; (ST400) Obtain a contrast phase of a plastic lens; (ST500) Obtain a subtracting contrast phase