| 摘要 |
PROBLEM TO BE SOLVED: To reduce adverse effects on an optical performance due to insufficient holding rigidity under a severe temperature environment and adverse effects on an optical performance and strength due to stress generated on a lens.SOLUTION: A lens holding mechanism comprises: a lens barrel 20 that has an annular projection 23 projected from an inner peripheral surface 22; a lens barrel retainer 30 fitted into the inside of the lens barrel 20; a lens 10 that has a rotationally symmetric shape and is held by the projection 23 and the lens barrel retainer 30; and a filler 50 with which a first space 80 that is formed by a side surface 11 of the lens 10, the inner peripheral surface 22 of the lens barrel 20, the lens barrel retainer 30, and the projection 23 is filled. A first value is a value of a ratio of the amount of change in the volume of the first space resulting from temperature change and the amount of change in the volume of the filler resulting from temperature change. The value is 0.9 or more and 1.1 or less.SELECTED DRAWING: Figure 1 |
