Imaging lens and imaging apparatus

1. An imaging lens, comprising, in order from an object side toward an image side:

a first lens having a convex surface facing the object side, and the first lens having a positive refractive power;

a second lens being a meniscus lens having a negative refractive power;

a third lens having a concave surface facing the imaging side, and two surfaces thereof being aspherical;

a fourth lens being a meniscus lens having a positive refractive power, the fourth lens having a convex surface facing the image side;

a fifth lens having a negative refractive power, the fifth lens having a concave surface facing the image side on an optical axis, the surface facing the image side having an inflection point outside the optical axis, and two surfaces thereof being aspherical; and

a sixth lens having a rear surface facing the image side and a front surface facing the object side, the rear surface being aspherical with a inflection point outside an optical axis, the front surface having a curvature less than any curvatures of the other lenses, and the sixth lens serving as an infrared cut-off filter;

wherein the imaging lens satisfies the following conditions (1) and (2):

TTL/ 2 ih< 0.8   (1)

0.75< ih/f< 0.9   (2)

wherein TTL is a distance on the optical axis from the surface of the first lens facing the object side toward an image surface, ih is a maximal image height, and f is a focal length of an overall imaging lens system; and

wherein the sixth lens serves as the infrared cut-off filter due to a material of the lens.

2. An imaging lens, comprising, in order from an object side toward an image side:

a first lens having a convex surface facing the object side, and the first lens having a positive refractive power;

a second lens being a meniscus lens having a negative refractive power;

a third lens having a concave surface facing the imaging side, and two surfaces thereof being aspherical;

a fourth lens being a meniscus lens having a positive refractive power, the fourth lens having a convex surface facing the image side;

a fifth lens having a negative refractive power, the fifth lens having a concave surface facing the image side on an optical axis, the surface facing the image side having an inflection point outside the optical axis, and two surfaces thereof being aspherical; and

a sixth lens having a rear surface facing the image side and a front surface facing the object side, the rear surface being aspherical with a inflection point outside an optical axis, the front surface having a curvature less than any curvatures of the other lenses, and the sixth lens serving as an infrared cut-off filter;

wherein the imaging lens satisfies the following conditions (1) and (2):

TTL/ 2 ih< 0.8   (1)

0.75< ih/f< 0.9   (2)

wherein TTL is a distance on the optical axis from the surface of the first lens facing the object side toward an image surface, ih is a maximal image height, and f is a focal length of an overall imaging lens system; and

wherein the sixth lens is provided with an infrared cut-off layer on the front surface.

3. The imaging lens according to claim 1 , wherein the sixth lens is a compound lens constituted by a substrate portion located on the object side and an aspherical lens located on the image side.

4. The imaging lens according to claim 1 , wherein the imaging lens satisfies the following conditions (3) and (4):

0.9< f/f 12345<1.1   (3)

−0.5≤ f/f 6≤0.3   (4)

wherein f is the focal length of the overall imaging lens system, f12345 is a combined focal length of the first lens, the second lens, the third lens, the fourth lens, and the fifth lens, and f6 is a focal length of the sixth length.

5. An imaging apparatus, comprising:

an imaging lens; and

an imaging element configured to convert an optical image obtained from the imaging lens to an electric signal;

wherein the imaging lens comprises, in order from an object side toward an image side:

a first lens having a convex surface facing the object side, and the first lens having a positive refractive power;

a second lens being a meniscus lens having a negative refractive power;

a third lens having a concave surface facing the imaging side, and two surfaces thereof being aspherical;

a fourth lens being a meniscus lens having a positive refractive power, the fourth lens having a convex surface facing the image side;

a fifth lens having a negative refractive power, the fifth lens having a concave surface facing the image side on an optical axis, the surface facing the image side having an inflection point outside the optical axis, and two surfaces thereof being aspherical; and

a sixth lens having a rear surface facing the image side and a front side facing the object side, the rear surface being aspherical with a inflection point outside an optical axis, the front surface having a curvature less than any curvatures of the other lenses, and the sixth lens serving as an infrared cut-off filter;

wherein the imaging lens satisfies the following conditions (1) and (2):

TTL/ 2 ih< 0.8   (1)

0.75< ih/f< 0.9   (2)

wherein TTL is a distance on the optical axis from the surface of the first lens facing the object side toward an image surface, ih is a maximal image height, and f is a focal length of an overall imaging lens system, and

wherein the sixth lens serves as the infrared cut-off filter due to a material of the lens.

6. The imaging apparatus according to claim 5 , wherein the sixth lens is a compound lens constituted by a substrate portion located on the object side and an aspherical lens located on the image side.

7. The imaging apparatus according to claim 5 , wherein the imaging lens satisfies the following conditions (3) and (4):

0.9< f/f 12345<1.1   (3)

−0.5≤ f/f 6≤0.3   (4)

wherein f is the focal length of the overall imaging lens system, f12345 is a combined focal length of the first lens, the second lens, the third lens, the fourth lens, and the fifth lens, and f6 is a focal length of the sixth length.