Kantatsu Co., Ltd.

Sharp Kabushiki Kaisha Corporation

Tokyo Visionary Optics Co., Ltd.

Kaoru Yamazaki

Shingo Yuza

Hisao Fukaya

Norimichi Shigemitsu

Yoshihito Ishizue

There is provided an imaging lens with high-resolution which satisfies demand of wide field of view, low-profileness and low F-number in well balance, and excellently corrects aberrations. An imaging lens comprises, in order from an object side to an image side, a first lens, a second lens having negative refractive power near the optical axis, a third lens having a convex surface facing the image side near the optical axis, a fourth lens and a fifth lens, wherein said first lens has negative refractive power near the optical axis, an image-side surface of said fifth lens has a convex surface facing the image side near the optical axis, and below conditional expressions are satisfied:3.00&#x3c;(4/)&#xd7;100&#x3c;5.900.40&#x3c;2/5&#x3c;1.45whereT4: a distance along the optical axis from the image-side surface of the fourth lens to the object-side surface of the fifth lens,f: a focal length of the overall optical system of the imaging lens,f2: a focal length of the second lens,f5: a focal length of the fifth lens.

Imaging lens

There is provided an imaging lens with high-resolution which realizes the wide field of view, low-profileness, and low F-value in well balance, and proper correction of aberrations. An imaging lens comprising in order from an object side to an image side, a first lens having a convex surface facing the object side near an optical axis and negative refractive power, a second lens having negative refractive power, a third lens, a fourth lens having biconvex shape near the optical axis, and a fifth lens, wherein each lens of the first lens to the fifth lens is arranged without being cemented, and a below conditional expression (1) is satisfied:0.50&#x3c;5/6&#x3c;12.50&#x2003;&#x2003;(1)

There is provided an imaging lens with high-resolution which satisfies the wide field of view, the low-profileness and the low F-number in well balance, and excellently corrects aberrations. An imaging lens comprises in order from an object side to an image side, a first lens having negative refractive power, an aperture stop, a second lens, a third lens being a double-aspheric lens, a fourth lens having positive refractive power, and a fifth lens being a double-sided aspheric lens, wherein a below expression is satisfied:&#x2212;0.07&#x3c;(1&#x2212;1)/(1&#xd7;)&#xd7;1000&#x3c;0.07whereN1: refractive index at d-ray of the first lens,r1: curvature radius of the object-side surface of the first lens,f: focal length of the overall optical system.

There is provided an imaging lens with high-resolution which satisfies, in well balance, demand of the wide field of view, the low-profileness and the low F-number and excellently corrects aberrations. An imaging lens comprises in order from an object side to an image side, a first lens having negative refractive power, a second lens, a third lens, a fourth lens, and a fifth lens, wherein said second lens has the negative refractive power, and below conditional expressions are satisfied:0.1&#x3c;2/3&#x3c;1.169&#x3c;3/4&#x3c;20&#x2212;0.1&#x3c;5/6&#x3c;1.4whereT2: distance along an optical axis from an image-side surface of the second lens to an object-side surface of the third lens,T3: distance along the optical axis from an image-side surface of the third lens to an object-side surface of the fourth lens,r3: paraxial curvature radius of an object-side surface of the second lens,r4: paraxial curvature radius of an image-side surface of the second lens,r5: paraxial curvature radius of an object-side surface of the third lens, andr6: paraxial curvature radius of an image-side surface of the third lens.

It is possible to (i) cause a sixth lens to more effectively correct various aberrations and (ii) make an optical overall length shorter. A first lens (L) has positive refractive power. A fifth lens (L) and a sixth lens (L) each have negative refractive power. An object-side surface (LF) of the first lens (L) is a convex surface. At least one of an object-side surface and an image plane-side surface of each of a second lens (L), a third lens (L), a fourth lens (L), and the fifth lens (L) is an aspheric surface. An object-side surface (LF) of the sixth lens (L) is a concave surface and is an aspheric surface. An image plane-side surface (LR) of the sixth lens (L) is an optically planar surface throughout a region corresponding to an effective diameter of the image plane-side surface (LR) of the sixth lens (L).

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Sukagawa, Japan

Kaoru Yamazaki