| 摘要 |
PROBLEM TO BE SOLVED: To improve sensitivity of an optical sensor.SOLUTION: An optical sensor includes a sensing part, a light-emitting element 3, a light-receiving element, and a lens that condenses light from the light-emitting element 3 and has a first convex curved face 51 protruding toward the light-emitting element 3 and a second convex curved face 52 opposing to the first convex curved face 51, protruding on the opposite side to the first convex curved face 51, and having a larger radius of curvature than that of the first convex curved face 51. The first convex curved face 51 is arranged in such a manner that an optical path of the light incident from the light-emitting element 3 intersects the optical axis of the first convex curved face 51 in a region between the first convex curved face 51 and the second convex curved face 52; the second convex curved face 52 is arranged in such a manner that an optical path of light incident to the second convex curved face 52 intersects the optical axis of the second convex curved face 52. In the region between the first convex curved face 51 and the second convex curved face 52, a distance between the optical axis of the first convex curved face 51 and an incident point of the incident light to the first convex curved face 52 is larger than a distance between the optical axis of the second convex curved face 52 and an incident point of the incident light to the second convex curved face 52.SELECTED DRAWING: Figure 3 |
