Measuring method and measuring apparatus

An apparatus for measuring a lens, comprising:

• an incident wave front generating optical system for generating such a wave front that light beams are simultaneously incident perpendicularly upon only a plurality of annular zones on one surface of said lens;
• an interferometer for causing an interference by making the light beams reflected from the plurality of annular zones travel back along an incident light path;
• and
• a lens aligning mechanism, capable of adjusting a disposition of said lens, for aligning said lens on the basis of interference fringes formed by the light beams reflected from the plurality of annular zones.

A method of measuring a lens, comprising:

• a rotating step of rotating said lens through an angle smaller than one rotation;
• a step of obtaining data about variations in condition of causing interference fringes formed by light from respective ones of the two surfaces of said lens;
• and
• an eccentricity measuring step of obtaining an eccentricity between the two surfaces of said lens on the basis of the variation in the condition of causing the interference fringes.

An apparatus for measuring an eccentricity between two surfaces of a lens, comprising:

• incident wave front generating means for generating such a wave front that light beams are incident upon each of two surfaces of said lens;
• interfering means for causing interference by making light beams reflected from each of the two surfaces travel back along an incident light path;
• lens aligning means capable of making a disposing adjustment of said lens for aligning said lens on the basis of the interference fringes formed by respective ones of the light beams reflected from the two surfaces;
• and
• light beam adjusting means capable of making a disposing adjustment for shifting the light beams incident upon at least one of the two surfaces of said lens with a disposing adjustment of said lens by said lens aligning means.