Optical system with wavelength selecting device
AssigneeNikon Corporation
InventorsAkihiko Obama, Kouichi Ohshita, Mami Muratani
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Abstract
The object is to provide an optical system with a wavelength selecting device. According to one aspect of the present invention, an optical system with a wavelength selecting device includes, in order from an object along an optical axis, an objective optical system composed of optical elements having refractive power and an aperture stop, a no-power optical group composed of optical elements having no refractive power, and an imaging device. The no-power optical group includes the wavelength selecting device for making short wavelength light be selectively substantially non-transparent. The wavelength selecting device preferably satisfies the predetermined conditional expressions.
Claims54
An optical system with a wavelength selecting device comprising, in order from an object along an optical axis:
- an objective optical system composed of optical elements having refractive power and an aperture stop;
- a no-power optical group composed of optical elements having no refractive power;
- and
- an imaging device;
- the no-power optical group including the wavelength selecting device for making short wavelength light be selectively substantially non-transparent;
- and
- the following conditional expression being satisfied by the wavelength selecting device:
- 390<λV50<430
- where λV50 denotes the wavelength (unit:
- nm) of short wavelength light whose transmittance of the wavelength selecting device is 50%.
An optical system with a wavelength selecting device includes, in order from an object along the optical axis;
- an objective optical system composed of an optical element having refractive power and an aperture stop;
- a no-power optical group composed of optical elements having no refractive power;
- and
- an imaging device I;
- the no-power optical group including a wavelength selecting device which is, with respect to short wavelength light, selectively substantially non-transparent;
- and
- the wavelength selecting device being an interference filter which is, with respect to the short wavelength light, selectively substantially non-transparent by the interference film formed on the surface only of the no-power optical group.
An optical system comprising:
- a plurality of lens elements;
- and
- an optical member having wavelength selecting characteristic;
- the optical member being composed of an interference film formed on a lens surface of the lens elements;
- and
- the following conditional expressions being satisfied;
- 0<|Φ/R|<0.8 0°≦|B|<13°
- where Φ denotes the effective diameter of the lens surface, R denotes the radius of curvature of the lens surface, and B denotes an angle of the principal ray passing through the lens surface relative to the optical axis at the lens surface in the air side.
An optical system comprising:
- a plurality of lens elements;
- and
- an optical member having wavelength selecting characteristic;
- the optical member being composed of an interference film formed on a lens surface of the lens elements;
- the optical system being composed of a negative lens group and a positive lens group adjoining to the negative lens group;
- the negative lens group including three lens elements of a first negative lens element, a second negative lens element, and a positive lens element;
- and
- the optical member being formed on the image side surface of the second negative lens element.
An optical system comprising:
- a plurality of lens elements;
- and
- an optical member having wavelength selecting characteristic;
- the optical member being composed of an interference film formed on a lens surface of the lens elements;
- the optical system being composed of a negative lens group and a positive lens group adjoining to the negative lens group;
- the positive lens group being composed of a positive lens element locating to the most object side of the positive lens group;
- and
- the optical member being formed on the image side surface of the positive lens element.
An optical system comprising:
- a plurality of lens elements;
- and
- an optical member having wavelength selecting characteristic;
- the optical member being composed of an interference film formed on a lens surface of the lens elements;
- the optical system being composed of a negative lens group, a fist positive lens group adjoining to the negative lens group, and a second positive lens group locating to the most image side of the optical system;
- and
- the optical member being formed on the most image side surface of the second positive lens group.
Dependencies are inferred from the claim text.