TOOL FOR OPTICAL ELEMENT MEASUREMENT, AND INSTRUMENT, AND METHOD FOR SURFACE SHAPE MEASUREMENT ON OPTICAL ELEMENT

PROBLEM TO BE SOLVED: To provide a tool for optical element measurement, to readily determine the direction of an optical element which is an object to be measured in a shape measuring instrument. SOLUTION: A rotation limiting member 70 has a recessed part 71 on the optical element OE side, and the recessed part 71 fits to flat parts FP and a projection part PP formed on the optical element OE, thereby adjusting the rotational position of the optical element OE about an optical axis OA. The flat parts FP and the projection part PP are irregular parts different from adjoining parts, with respect to the contour of an outer edge part PA, and are portions where a gate has been cut which is inevitably formed, when the optical element OE is injection-molded. It may be necessary to determine the direction of the optical element OE in the shape measurement of the optical element OE, and the projection part PP, etc. can be used for this purpose. The projection part PP, etc. serve as references, when shape measurement results on the optical element OE are utilized. COPYRIGHT: (C)2007,JPO&INPIT