| 摘要 |
PURPOSE:To execute the focus detection with high accuracy by forming integrally and constituting a lens of a part of a light projection lens and a pattern, and an illuminating means with a transparent adhesive having a presdribed refractive index. CONSTITUTION:A light projection lens 15 consists of a first lens 1 having positive refracting power whose both lens surfaces are convex surface and a second convex/planar lens 2 in which the lens surface of a subject side is the convex surface and the lens surface of a light source side (pattern side) is roughly a plane, a pattern 3 consists of a prescribed pattern, and an illuminating means 4 consists of an LED, etc., and provided with a light emitting part 5 in a transparent resin. Also, a second lens 2, the pattern 3, and the LED 4 are stuck in this order with a transparent adhesive having a refractive index being roughly equal to a refractive index of a material of an optical member and constituted integrally. Accordingly, while utilizing enough an opening of a first lens 1, a focal distance of the whole light projection system is shortened, and as a result, the pattern 3 can be projected to a subject being in a long distance and extending over a wide range. In such a way, the focus detection can be executed with high accuracy. |
