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US 12,742,911 B2Granted
Optical system and image capturing apparatus including the same
AssigneeCanon Kabushiki Kaisha
InventorKana Kobayashi
Life of this patent
Estimating the term…
Abstract
An optical system OL consists of a front lens group L and a negative lens Gn on an image side of the front lens group L. The lens Gn includes a first lens surface, and the first lens surface is a lens surface that satisfies the following inequality: 45°<|Θ|<65°, where Θ is an opening angle at an effective diameter. The first lens surface is provided with an antireflection film, and a predetermined inequality relating to a reflectance is satisfied.
Claims11
A system consisting of, in order from an object side to an image side, a front lens group and a negative lens Gn,
- wherein the negative lens Gn includes a first lens surface, and the first lens surface is a lens surface that satisfies the following inequality:
- 45°<|Θ|<65°,
- where Θ is an opening angle at an effective diameter,
- wherein the first lens surface is provided with an antireflection film, and
- wherein the following inequalities are satisfied:
- R_R45<1.5%,
- R_G45<1.5%, and
- R_R0<1.0%,
- 0.0<Rmax_R0/Rmax_G0<0.1,
- where R_R0 is a reflectance in reflecting a light ray with a wavelength of 700 nm that is vertically incident on a position on an optical axis of the first lens surface, R_R45 is a reflectance in reflecting a light ray with a wavelength of 700 nm that is vertically incident on a position at an opening angle of 45 degrees on the first lens surface, R_G45 is a reflectance in reflecting a light ray with a wavelength of 530 nm that is vertically incident on the position at an opening angle of 45 degrees on the first lens surface, Rmax_G0 is a maximum value of a reflectance in reflecting a light ray vertically incident on the position on the optical axis of the first lens surface in a wavelength range of 450 nm to 550 nm, and Rmax_R0 is a maximum value of a reflectance in reflecting a light ray vertically incident on the position on the optical axis of the first lens surface in a wavelength range of 650 nm to 750 nm.
7 more elements
An apparatus comprising:
- a system;
- and
- a sensor configured to receive an image formed by the system,
- wherein the system consisting of, in order from an object side to an image side, a front lens group, and a negative lens Gn,
- wherein the negative lens Gn includes a first lens surface, and the first lens surface is a lens surface that satisfies the following inequality:
- 45°<|Θ|<65°,
- where Θ is an opening angle at an effective diameter,
- wherein the first lens surface is provided with an antireflection film, and
- wherein the following inequalities are satisfied:
- R_R45<1.5%,
- R_G45<1.5%,
- R_R0<1.0%, and
- 0.5<D_45/D_0<0.9,
- where R_R0 is a reflectance in reflecting a light ray with a wavelength of 700 nm that is vertically incident on a position on an optical axis of the first lens surface, R_R45 is a reflectance in reflecting a light ray with a wavelength of 700 nm that is vertically incident on a position at an opening angle of 45 degrees on the first lens surface, R_G45 is a reflectance in reflecting a light ray with a wavelength of 530 nm that is vertically incident on the position at an opening angle of 45 degrees on the first lens surface, D_45 is an optical thickness of the antireflection film at the position at an opening angle of 45 degrees on the first lens surface, and D_0 is an optical thickness of the antireflection film at the position on the optical axis of the first lens surface.
11 more elements
An apparatus comprising:
- a system;
- and
- a sensor configured to receive an image formed by the system,
- wherein the system consisting of, in order from an object side to an image side, a front lens group, and a negative lens Gn,
- wherein the negative lens Gn includes a first lens surface, and the first lens surface is a lens surface that satisfies the following inequality:
- 45°<|Θ|<65°,
- where Θ is an opening angle at an effective diameter,
- wherein the first lens surface is provided with an antireflection film, and
- wherein the following inequalities are satisfied:
- R_R45<1.5%,
- R_G45<1.5%,
- R_R0<1.0%, and
- 0.0<Rmax_R0/Rmax_G0<0.1,
- where R_R0 is a reflectance in reflecting a light ray with a wavelength of 700 nm that is vertically incident on a position on an optical axis of the first lens surface, R_R45 is a reflectance in reflecting a light ray with a wavelength of 700 nm that is vertically incident on a position at an opening angle of 45 degrees on the first lens surface, R_G45 is a reflectance in reflecting a light ray with a wavelength of 530 nm that is vertically incident on the position at an opening angle of 45 degrees on the first lens surface, Rmax_G0 is a maximum value of a reflectance in reflecting a light ray vertically incident on the position on the optical axis of the first lens surface in a wavelength range of 450 nm to 550 nm, and Rmax_R0 is a maximum value of a reflectance in reflecting a light ray vertically incident on the position on the optical axis of the first lens surface in a wavelength range of 650 nm to 750 nm.
11 more elements
An apparatus comprising:
- a system;
- and
- a sensor configured to receive an image formed by the system,
- wherein the system consisting of, in order from an object side to an image side,
- a front lens group, and a negative lens Gn,
- wherein the negative lens Gn includes a first lens surface, and the first lens surface is a lens surface that satisfies the following inequality:
- 45°<|Θ|<65°,
- where Θ is an opening angle at an effective diameter,
- wherein the first lens surface is provided with an antireflection film, and
- wherein the following inequalities are satisfied:
- R_R45<1.5%,
- R_G45<1.5%,
- R_R0<1.0%, and
- 0.5<D_45/D_0<0.9,
- where R_R0 is a reflectance in reflecting a light ray with a wavelength of 700 nm that is vertically incident on a position on an optical axis of the first lens surface, R_R45 is a reflectance in reflecting a light ray with a wavelength of 700 nm that is vertically incident on a position at an opening angle of 45 degrees on the first lens surface, R_G45 is a reflectance in reflecting a light ray with a wavelength of 530 nm that is vertically incident on the position at an opening angle of 45 degrees on the first lens surface, D_45 is an optical thickness of the antireflection film at the position at an opening angle of 45 degrees on the first lens surface, and D_0 is an optical thickness of the antireflection film at the position on the optical axis of the first lens surface.
12 more elements
Dependencies are inferred from the claim text.