Attachment lens
AssigneeMitsubishi Gas Chemical Company, Inc.
InventorYuki TAKASE
Life of this patent
Estimating the term…
Abstract
The present disclosure relates to an attachment lens including a first lens having positive or negative optical power, a second lens having positive optical power, and a third lens having positive or negative optical power in order from an object side, wherein each of both surfaces of the first lens, the second lens, and the third lens is an aspheric surface, and the attachment lens satisfies the following expressions (1), (2), (3), (4), (5), and (6): - 10. ≤ f 1 / f ≤ 8. ( 1 ) - 0.15 ≤ φ 1 / v 1 ≤ 0.05 ( 2 ) 0.1 ≤ φ 2 / n 2 ≤ 2. ( 3 ) - 80. ≤ f 3 / f ≤ 30. ( 4 ) - 0.3 ≤ φ 3 / n 3 ≤ 0.9 ( 5 ) - 0.02 ≤ φ 3 / v 3 ≤ 0.05 ( 6 )
Claims20
An attachment lens comprising a first lens having positive or negative optical power, a second lens having positive optical power, and a third lens having positive or negative optical power in order from an object side,
- wherein each of both surfaces of the first lens, the second lens, and the third lens is an aspheric surface, and
- the attachment lens satisfies the following expressions (1), (2), (3), (4), (5), and (6):
- -
- 10.
- ≤
- f
-
- 1
- /
- f
- ≤
- 8.
- (
- 1
- )
- -
- 0.15
- ≤
- φ1
- /
- v
-
- 1
- ≤
- 0.05
- (
- 2
- )
- 0.1
- ≤
- φ2
- /
- n
-
- 2
- ≤
- 2.
- (
- 3
- )
- -
- 80.
- ≤
- f
-
- 3
- /
- f
- ≤
- 30.
- (
- 4
- )
- -
- 0.3
- ≤
- φ3
- /
- n
-
- 3
- ≤
- 0.9
- (
- 5
- )
- -
- 0.02
- ≤
- φ3
- /
- v
-
- 3
- ≤
- 0.05
- (
- 6
- )
- f:
- a focal length of the entire system of the attachment lens with respect to the d line,
- f1:
- a focal length of the first lens with respect to the d line,
- φ1:
- a product of power of the first lens with respect to the d line and f, expressed as f/f1,
- ν1:
- an Abbe number of the first lens,
- f2:
- a focal length of the second lens with respect to the d line,
- φ2:
- a product of power of the second lens with respect to the d line and f, expressed as f/f2,
- n2:
- a refractive index of the second lens with respect to the d line,
- f3:
- a focal length of the third lens with respect to the d line,
- φ3:
- a product of power of the third lens with respect to the d line and f, expressed as f/f3,
- n3:
- a refractive index of the third lens with respect to the d line, and
- ν3:
- an Abbe number of the third lens.
Dependencies are inferred from the claim text.