Lens apparatus and image capturing apparatus including the same
AssigneeCanon Kabushiki Kaisha
InventorsMaki Yokoya, Yoshihisa Tashiro, Takayoshi Yokoyama
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Abstract
A lens apparatus includes an optical system L0 including a plurality of lenses. The optical system L0 is changeable to a first state in which a focal length of the optical system L0 is a first focal length and a second state in which the focal length is a second focal length shorter than the first focal length, by changing one or some of the plurality of lenses. The maximum image heights and maximum angle of views in the first state and the second state are substantially constant and satisfy a predetermined condition.
Claims14
A lens apparatus comprising:
- an optical system including a plurality of lenses,
- wherein the optical system is changeable to a first state in which a focal length of the optical system is a first focal length and a second state in which the focal length of the optical system is a second focal length shorter than the first focal length by changing one or some of the plurality of lenses of the optical system, and
- wherein the following conditional expressions are satisfied:
- 0.90<Ymax1/Ymax2<1.10,
- 0.90<θmax1/θmax2<1.10,
- 0.04<ΔYmax<0.50, and
- 1.05<fL/fS<4.00,
- where Ymax1 is a maximum image height in the first state, Ymax2 is a maximum image height in the second state, θmax1 is a maximum half angle of view in the first state, and θmax2 is a maximum half angle of view in the second state, ΔYmax is a maximum value of ΔY(θ) defined as ΔY(θ)=|Y1(θ)/Ymax1−Y2(θ)/Ymax2|, Y1(θ) is an image height corresponding to a half angle of view θ (0≤θ≤θmax1) in the first state, Y2(θ) is an image height corresponding to a half angle of view θ (0≤θ≤θmax2) in the second state, and fL is the first focal length, and fS is the second focal length.
An image capturing apparatus comprising a lens apparatus and an image capturing element configured to receive an image formed by an optical system of the lens apparatus,
- wherein the optical system includes a plurality of lenses,
- wherein the optical system is changeable to a first state in which a focal length of the optical system is a first focal length and a second state in which the focal length of the optical system is a second focal length shorter than the first focal length, by changing one or some of the plurality of lenses of the optical system, and
- wherein the following conditional expressions are satisfied:
- 0.90<Ymax1/Ymax2<1.10,
- 0.90<θmax1/θmax2<1.10,
- 0.04<ΔYmax<0.50, and
- 1.05<fL/fS<4.00,
- where Ymax1 is a maximum image height in the first state, Ymax2 is a maximum image height in the second state, θmax1 is a maximum half angle of view in the first state, and θmax2 is a maximum half angle of view in the second state, ΔYmax is a maximum value of ΔY(θ) defined as ΔY(θ)=|Y1(θ)/Ymax1−Y2(θ)/Ymax2|, Y1(θ) is an image height corresponding to a half angle of view θ (0≤θ≤θmax1) in the first state, Y2(θ) is an image height corresponding to a half angle of view θ (0≤θ≤θmax2) in the second state, and fL is the first focal length, and fS is the second focal length.
Dependencies are inferred from the claim text.