Imaging lens
AssigneeTokyo Visionary Optics Co., Ltd.
InventorMasaya Hashimoto
Life of this patent
Estimating the term…
Abstract
An imaging lens which uses a larger number of constituent lenses for higher performance and features compactness and a wide field of view. The imaging lens is composed of seven lenses to form an image of an object on a solid-state image sensor. The constituent lenses are arranged in the following order from an object side to an image side: a first lens with positive refractive power; a second lens with positive or negative refractive power; a third lens with negative refractive power; a fourth lens with positive or negative refractive power as a double-sided aspheric lens; a meniscus fifth lens having a convex surface on the image side; a sixth lens with positive or negative refractive power as a double-sided aspheric lens; and a seventh lens with negative refractive power, in which an air gap is provided between lenses.
Claims19
An imaging lens for a solid-state image sensor, comprising in order from an object side to an image side of the imaging lens:
- a first lens having positive refractive power;
- a second lens having positive or negative refractive power;
- a third lens having negative refractive power;
- a fourth lens that is a double-sided aspheric lens having positive or negative refractive power;
- a fifth lens that is a double-sided aspheric lens having positive or negative refractive power;
- a sixth lens that is a double-sided aspheric lens having positive or negative refractive power;
- a seventh lens that is a double-sided aspheric lens having negative refractive power;
- and
- air gaps disposed between each pair of adjacent lenses,
- wherein the imaging lens has a total of seven single lenses, the third lens has a meniscus shape near an optical axis, the sixth lens has a meniscus shape near the optical axis, and conditional expression (7) below is satisfied:
- 50<νd2<70 (7)
- where
- νd2:
- Abbe number of the second lens at d-ray.
An imaging lens for a solid-state image sensor, comprising in order from an object side to an image side of the imaging lens:
- a first lens having positive refractive power;
- a second lens having positive or negative refractive power;
- a third lens having negative refractive power;
- a fourth lens that is a double-sided aspheric lens having positive or negative refractive power;
- a fifth lens that is a double-sided aspheric lens having positive or negative refractive power;
- a sixth lens that is a double-sided aspheric lens having positive or negative refractive power;
- a seventh lens that is a double-sided aspheric lens having negative refractive power;
- and
- air gaps disposed between each pair of adjacent lenses,
- wherein the first lens has a meniscus shape near an optical axis, the fifth lens has a meniscus shape near the optical axis, the sixth lens has a meniscus shape near the optical axis, and an image-side surface of the sixth lens has an aspheric shape in which a portion near an optical axis has a concave shape and the concave shape changes to a convex shape in a peripheral portion distant from the optical axis.
Dependencies are inferred from the claim text.