摘要 |
Provided is an image pickup lens that despite being small is favorably corrected for aberrations and has a five element configuration that is wide angle and has a bright F-number also provided is an image pickup device and a portable terminal using the image pickup lens. The image surface side of the fifth lens has an aspherical shape, has an inflection point at a position other than a position that intersects with the light axis, and satisfies the following formulae: −5.0<(r1+r2)/(r1−r2)≦−1.0 (1); 0.90<f1/f<1.70 (2); 0.35<ΣDL13/f<0.55 (3). Provided that r1: curvature radius of the first lens object side surface, r2: curvature radius of the first lens image side surface, f1: focal distance of the first lens, f: focal distance of the entire image pickup lens system, ΣDL13: distance on the optical axis from object side surface of the first lens to image side surface of the third lens. |
主权项 |
1. An image pickup lens to form an image of an object onto a photoelectric conversion section, comprising, in the order from an object side thereof, a first lens which has a positive refractive power and includes a convex surface facing the object side; a second lens which has a negative refractive power; a third lens which includes an aspheric configuration on at least one surface thereof; a fourth lens which has a positive refractive power and includes a convex surface facing an image side; and a fifth lens which has a negative refractive power and includes a biconcave configuration, wherein an image-side surface of the fifth lens includes an aspheric configuration and has an inflection point at a position other than an intersection point with an optical axis, and the following conditional expressions are satisfied,
−5.0<(r1+r2)/(r1−r2)≦−1.0 (1) 0.90<f1/f<1.70 (2) 0.35<ΣDL13/f<0.55 (3) wherein in the above expressions, r1 is a radius of curvature of an object side surface of the first lens, r2 is a radius of curvature of an image side surface of the first lens, f1 is a focal length of the first lens, f is a focal length of the whole system of the image pickup lens, and ΣDL13 is a distance on the optical axis from the object side surface of the first lens to the image side surface of the third lens. |