| 摘要 |
PURPOSE:To align the optical axes of a lens blank and a thin film with each other with high accuracy by providing the collar part of a compound lens with >=3 rod type projection or recess parts which extend radially from the center of the optical axis of a lens. CONSTITUTION:The rod type projection parts 3 are provided in radial directions A from the optical axis 4. Consequently, the collared lens blink has no variation in the direction to the projection parts 3 even if having an error in external diameter size owing to heat shrinkage in molding. Further, roll type recess parts 7 of a sleeve 6 are provided in radial directions as well as the projection parts 3 of the collar 2. Furthermore, the collared lens blank is molded having a gate at the center part to shrink thermally and uniformly toward the optical axis. Consequently, the rod type projection parts are molded more accurately and the accuracy of the optical axis alignment is improved.
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