Imaging optics and imaging device including seven lenses of -++-++- or -++-+-refractive powers
AssigneeTamron Co., Ltd.
InventorsToshihide Hayashi, Koichiro Yokota, Takayuki Noda
Life of this patent
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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.
Claims15
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≤f2/f≤1.15 (1-1)
- 0.38≤f3/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.
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≤f2/f≤1.15 (1-1)
- 0.38≤f3/f≤1.10 (1-2)
- 0.015≤thi_max/oal≤0.210 (1-3)
- 0.20≤R7/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.
Dependencies are inferred from the claim text.