Imaging optics and imaging device including seven lenses of -++-++- or -++-+-refractive powers

Patent metadata

Field	Value
Publication number	US-11531188-B2
Application number	US-201916716715-A
Country	US
Kind code	B2
Filing date	Dec 17, 2019
Priority date	May 10, 2019
Publication date	Dec 20, 2022
Grant date	Dec 20, 2022

Abstract

An imaging optics including, in sequence starting from the object side, of a 1st lens G1 with a negative refractive power, a 2nd lens G2 with a positive refractive power, a 3rd lens G3 with a positive refractive power, and a 4th lens G4, a 5th lens G5, a 6th lens G6, and a 7th lens G7 with a negative refractive power, satisfying the conditional expressions.

First claim

What is claimed is:

1. An imaging optics comprising, in sequence starting from the object side, of a 1st lens with a negative refractive power, a 2nd lens with a positive refractive power, a 3rd lens with a positive refractive power, and a 4th lens, a 5th lens, a 6th lens, and a 7th lens with a negative refractive power, satisfying the following conditional expressions
0.50≤ f 2/ f≤ 1.15  (1-1)

0.38≤ f 3/ f≤ 1.10  (1-2)

0.015≤ thi _max/ oal≤ 0.210  (1-3)

where:
f: focal length of the imaging optics
f2: focal length of the 2nd lens
f3: focal length of the 3rd lens
thi_max: maximum lens spacing excluding back focal length
oal: optical length of the imaging optics from the object side surface of the 1st lens to imaging surface
f567: combined focal length of the 5th lens, the 6th lens, and the 7th lens.

2. The imaging optics of claim 1 , wherein the following conditional expression is satisfied
0.50≤| f 1|/ f≤ 1.71  (2)

where:
f1: focal length of the 1st lens.

3. The imaging optics of claim 1 , wherein the following conditional expression is satisfied
0.38≤| f 4|/ f≤ 1.32  (3)

where:
f4: focal length of the 4th lens.

4. The imaging optics of claim 1 , wherein the following conditional expression is satisfied
0.01 ≤thiG 1 G 2/ oal≤ 0.03  (4)

where:
thiG 1 G 2 : spacing of the 1st lens and the 2nd lens.

5. The imaging optics of claim 1 , wherein the following conditional expression is satisfied
0.88 ≤allthi/f≤ 2.15  (5)

where:
allthi: distance from the object side surface of the 1st lens to the image side surface of the 7th lens.

6. The imaging optics of claim 1 , wherein the following conditional expression is satisfied
0.20≤ R 7/ f≤ 0.43  (7)

where:
R7: paraxial radius of curvature of the image side surface of the 7th lens.

7. The imaging optics of claim 1 , wherein 1st lens is a biconcave lens.

8. The imaging optics of claim 1 , wherein the 2nd lens is a biconvex lens.

9. The imaging optics of claim 1 , wherein the object side surface of the 5th lens is a concave surface facing the object side.

10. The imaging optics of claim 1 , wherein the object side surface of the 6th lens is a concave surface facing the object side.

11. The imaging optics of claim 1 , wherein the 7th lens has a negative refractive power.

12. The imaging optics of claim 1 , wherein the image side surface of the 7th lens is a concave surface facing the image side, and has an inflection point not on the optical axis.

13. The imaging optics of claim 1 , wherein an aperture stop is disposed between the 2nd lens and the 3rd lens.

14. An imaging device comprising the imaging optics of claim 1 and an imaging element disposed at the imaging position of the imaging optics.

15. An imaging optics comprising, in sequence starting from the object side, of a 1st lens with a negative refractive power, a 2nd lens with a positive refractive power, a 3rd lens with a positive refractive power, and a 4th lens, a 5th lens, a 6th lens, and a 7th lens with a negative refractive power, satisfying the following conditional expressions
0.50≤ f 2/ f≤ 1.15  (1-1)

0.38≤ f 3/ f≤ 1.10  (1-2)

0.015≤ thi _max/ oal≤ 0.210  (1-3)

0.20≤ R 7/ f≤ 0.43  (7)

where:
f: focal length of the imaging optics
f2: focal length of the 2nd lens
f3: focal length of the 3rd lens
thi_max: maximum lens spacing excluding back focal length
oal: optical length of the imaging optics from the object side surface of the 1st lens to imaging surface
R7: paraxial radius of curvature of the image side surface of the 7th lens.

Assignees

• Tamron Kk

Inventors

• Hayashi Toshihide
• Yokota Koichiro
• Noda Takayuki

Classifications

• G02B13/0045 Primary

  having five or more lenses · CPC title

• G02B13/0015 Primary

  characterised by the lens design · CPC title

• G02B9/64

  having more than six components · CPC title