| 摘要 |
PROBLEM TO BE SOLVED: To review dimensional accuracy of each component of a photographic lens unit for an endoscope and to improve a product yield.SOLUTION: A first lens movable frame 26 and a second lens movable frame 27 are engaged with a cam shaft 25, and first and second movable lenses 22 and 23 are individually moved in an optical axis direction by rotation of the cam shaft 25. A sliding guide surface 35a of a coupling hole is set to a metal processing surface. The cam shaft 25, the lens movable frames 26 and 27, antireflection cylinders 36 and 37, lens frames 21a and 24a are subjected to black dye processing, and black layers 39 are formed on surfaces thereof. An inside of the minute coupling hole is not subjected to the black dye processing, and unevenness of the sliding guide surface due to the black dye processing is eliminated. Even when sliding surfaces of the lens movable frames 26 and 27 are subjected to the black dye processing, the sliding surfaces are outside surfaces, and, accordingly, dimensional accuracy thereof is maintained. The dimensional accuracy of both sliding surfaces is maintained. Smooth movement of the movable lenses can be performed by wire drive, and, in addition, a product yield is improved. |
