# US 11,994,656 B2 · Imaging lens including seven lenses of +−+0+−−,+−+0−+− or +−+0++− refractive powers

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- Number: US 11,994,656 B2
- Document ID: US11994656B2
- Status: Granted
- Kind: B2
- Application number: 17/344,177
- Filed: 2021-06-10
- Published: 2021-10-07
- Granted: 2024-05-28
- Earliest claimed: 2018-08-21
- Assignees: Tokyo Visionary Optics Co., Ltd.
- Applicants: Tokyo Visionary Optics Co., Ltd.
- Inventors: Koji Nitta
- Web page: https://patentgrep.com/patent/US11994656B2

## CPC

- G02B 13/0045: {having five or more lenses}
- G02B 9/64: having more than six components
- G02B: OPTICAL ELEMENTS, SYSTEMS OR APPARATUS

## Abstract

There is provided an imaging lens with excellent optical characteristics which satisfies demand of wide field of view, low-profileness and low F-number. An imaging lens comprises, in order from an object side to an image side, a first lens with positive refractive power having an object-side surface being convex in a paraxial region, a second lens with negative refractive power in a paraxial region, a third lens, a fourth lens being a double-sided aspheric lens, a fifth lens, a sixth lens having an image-side surface being concave in a paraxial region, and a seventh lens with negative refractive power having an image-side surface being concave in a paraxial region, wherein the image-side surface of the seventh lens is an aspheric surface having at least one pole point in a position off the optical axis, and predetermined conditional expressions are satisfied.

## Claims

### Claim 1

An imaging lens comprising in order from an object side to an image side,
a first lens with positive refractive power having an object-side surface being convex in a paraxial region,
a second lens with negative refractive power in a paraxial region,
a third lens,
a fourth lens being a double-sided aspheric lens,
a fifth lens,
a sixth lens having an image-side surface being concave in a paraxial region, and
a seventh lens with negative refractive power having an image-side surface being concave in a paraxial region, wherein the image-side surface of said seventh lens is an aspheric surface having at least one pole point in a position off the optical axis, an image-side surface of said first lens is concave in a paraxial region, said third lens is formed in a meniscus shape in a paraxial region, an image-side surface of said fifth lens is convex in a paraxial region, an object-side surface of said seventh lens is convex in a paraxial region, and the following conditional expressions (2), (3), and (4) are satisfied:
1.80<νd3/νd5<4.00 (2)
0.10<(T5/TTL)×100<0.40 (3)
10.00<νd4<29.00 (4)
where
νd3: an abbe number at d-ray of the third lens,
νd5: an abbe number at d-ray of the fifth lens,
T5: a distance along the optical axis from an image-side surface of the fifth lens to an object-side surface of the sixth lens,
TTL: a total track length, and
νd4: an abbe number at d-ray of the fourth lens.

### Claim 2 (depends on 1)

The imaging lens according to claim 1, wherein the following conditional expression (5) is satisfied:
0.60<νd2/νd5<1.40 (5)
where
νd2: an abbe number at d-ray of the second lens, and
νd5: an abbe number at d-ray of the fifth lens.

### Claim 3 (depends on 1)

The imaging lens according to claim 1, wherein the following conditional expression (7) is satisfied:
−2.30<(D2/f2)×100<−0.50 (7)
where
D2: a thickness along the optical axis of the second lens, and
f2: a focal length of the second lens.

### Claim 4 (depends on 1)

The imaging lens according to claim 1, wherein the following conditional expression (8) is satisfied:
0.30<(D5/|f5|)×100<6.50 (8)
where
D5: a thickness along the optical axis of the fifth lens, and
f5: a focal length of the fifth lens.

### Claim 5 (depends on 1)

The imaging lens according to claim 1, wherein the following conditional expression (11) is satisfied:
1.55<|f3/f7|<12.50 (11)
where
f3: a focal length of the third lens, and
f7: a focal length of the seventh lens.

### Claim 6 (depends on 1)

The imaging lens according to claim 1, wherein the following conditional expression (12) is satisfied:
0.50<r2/f<2.10 (12)
where
r2: a paraxial curvature radius of an image-side surface of the first lens, and
f: a focal length of the overall optical system of the imaging lens.

### Claim 7 (depends on 1)

The imaging lens according to claim 1, wherein the following conditional expression (13) is satisfied:
−8.50<r10/f<−0.70 (13)
where
r10: a paraxial curvature radius of an image-side surface of the fifth lens, and
f: a focal length of the overall optical system of the imaging lens.

### Claim 8

An imaging lens comprising in order from an object side to an image side,
a first lens with positive refractive power having an object-side surface being convex in a paraxial region,
a second lens with negative refractive power in a paraxial region,
a third lens,
a fourth lens being a double-sided aspheric lens,
a fifth lens,
a sixth lens having an image-side surface being concave in a paraxial region, and
a seventh lens with negative refractive power having an image-side surface being concave in a paraxial region, wherein the image-side surface of said seventh lens is an aspheric surface having at least one pole point in a position off the optical axis, an image-side surface of said first lens is concave in a paraxial region, said third lens is formed in a meniscus shape in a paraxial region,
an object-side surface and an image-side surface of said fourth lens are plane surfaces in a paraxial region, an image-side surface of said fifth lens is convex in a paraxial region, an object-side surface of said seventh lens is convex in a paraxial region, and the following conditional expressions (2) and (4) are satisfied:
1.80<νd3/νd5<4.00 (2)
10.00<νd4<29.00 (4)
where
νd3: an abbe number at d-ray of the third lens,
νd5: an abbe number at d-ray of the fifth lens, and
νd4: an abbe number at d-ray of the fourth lens.

### Claim 9

An imaging lens comprising in order from an object side to an image side,
a first lens with positive refractive power having an object-side surface being convex in a paraxial region,
a second lens with negative refractive power in a paraxial region,
a third lens,
a fourth lens being a double-sided aspheric lens,
a fifth lens,
a sixth lens having an image-side surface being concave in a paraxial region, and
a seventh lens with negative refractive power having an image-side surface being concave in a paraxial region, wherein the image-side surface of said seventh lens is an aspheric surface having at least one pole point in a position off the optical axis, an image-side surface of said first lens is concave in a paraxial region, said third lens is formed in a meniscus shape in a paraxial region,
an image-side surface of said fifth lens is convex in a paraxial region, an object-side surface of said seventh lens is convex in a paraxial region, and the following conditional expressions (2), (4), and (9) are satisfied:
1.80<νd3/νd5<4.00 (2)
10.00<νd4<29.00 (4)
1.00<(T3/TTL)×100<4.00 (9)
where
νd3: an abbe number at d-ray of the third lens,
νd5: an abbe number at d-ray of the fifth lens,
νd4: an abbe number at d-ray of the fourth lens,
T3: a distance along the optical axis from an image-side surface of the third lens to an object-side surface of the fourth lens, and
TTL: a total track length.