| 摘要 |
PROBLEM TO BE SOLVED: To provide a wide angle lens in which the total length of a lens system can be made short and the incident angle of a principal ray with respect to an imaging plane can be made small.SOLUTION: A wide angle lens 10 includes, in order from the object side to the image side, a first lens 11 having a negative refractive power, a second lens 12 having a positive refractive power, a third lens 13 having a negative refractive power, and a fourth lens 14 having a positive refractive power. Since a lens with a concave shape having a negative refractive power is arranged as the first lens 11, and a lens with a convex shape having a positive refractive power is arranged as the second lens 12, the total length of the lens system having an angle of view of 65 degrees or more is reduced to about 5 mm. Since the image side lens surface 14b of the fourth lens 14 has an inflection point, the direction of an emission light beam from the wide angle lens 10 can be controlled. |
