Objective lens system
AssigneeOlympus Optical Co., Ltd.
InventorToshiyuki Nagaoka
Life of this patent
Estimating the term…
Abstract
An objective lens system consisting of a first lens unit having a negative refractive power and a second lens unit having a positive refractive power wherein the first lens unit or the second lens unit comprises at least one radial type gradient index lens element which has a refractive index distribution in a radial direction from an optical axis. This objective lens system favorably corrects chromatic aberration and other aberrations by adequately selecting a value expressing an Abbe's number and a refractive power of medium for the radial type gradient index lens element.
Claims71
An objective lens system comprising in order from the object side:
- a first lens unit having a negative refractive power;
- and a second lens unit having a positive refractive power, wherein at least said first lens unit is a radial type gradient index lens element which has a refractive index distribution in a radial direction from an optical axis and wherein said radial type gradient index lens element satisfies the following condition (1):
- 1/V10<1/V00 (1)
- wherein the reference symbol V10 represents a dispersing power of said radial type gradient index lens element which is given by the formulae (b) and (c) shown below:
- V00=(N00d−1)/(N00F−N00C) (b)Vi0−Ni0d/(Ni0F−Ni0C)(i=1, 2, 3, . . . ) (c)
- wherein the reference symbols N00d, N00F and N00C represent refractive indices on an optical axis for the d-line, F-line and C-line respectively, and the reference symbols Ni0d, Ni0F and Ni0C designate values of a coefficient of a term r2 for the d-line, F-line and C-line respectively when a refractive index of said radial type gradient index lens element is expressed as a polynominal of r.
An objective lens system comprising in order from the object side:
- a first lens unit having a negative refractive power;
- and a second lens unit having a positive refractive power, wherein said second lens unit is a radial type gradient index lens element which has a refractive index distribution in a radial direction from an optical axis and wherein said objective lens system satisfies the following conditions (1) and (3):
- 1/V10<1/V00 (1)0.05<φ2m/φ<1.0 (3)
- wherein the reference symbol φ2m represents a refractive power of said radial type gradient index lens element used as the second lens unit and the reference symbol φ designates a refractive power of said objective lens system as a whole.
An objective lens system comprising in order from the object side:
- a first lens unit having a negative refractive power;
- and a second lens unit having a positive refractive power, wherein said objective lens system comprises at least one radial type gradient index lens element which has a refractive index distribution in a radial direction from an optical axis and wherein at least one of lens elements including said radial type gradient index lens element used for composing said lens system has at least one aspherical surface.
An objective lens system comprising in order from the object side:
- a first lens unit having a negative refractive power;
- and a second lens unit having a positive refractive power, wherein at least one radial type gradient index lens element which has a refractive index distribution in a radial direction from an optical axis is used in said second lens unit and wherein said radial type gradient index lens element has a shape of a positive lens element and satisfies the following condition (1):
- 1/V10<1/V00 (1)
- wherein the reference symbol V10 represents a dispersing power of said radial type gradient index lens element which is given by the formula (b) and (c) shown below:
- V00=(N00d−1)/(N00F−N00C) (b)Vi0=Ni0d/(Ni0F−Ni0C)(i=1, 2, 3, . . . ) (c)
- wherein the reference symbols N00d, N00F and N00C represent refractive indices on an optical axis for the d-line, F-line and C-line respectively, and the reference symbols Ni0d, Ni0F and Ni0C designate values of a coefficient of a term r2 for the d-line, F-line and C-line respectively when a refractive index of said radial type gradient index lens element is expressed as a polynominal of r.
An objective lens system comprising in order from the object side:
- a first lens unit having a negative refractive power;
- and a second lens unit having a positive refractive power, wherein at least one lens element is a radial type gradient index lens element which has a refractive index distribution in a radial direction from an optical axis and wherein said objective lens system comprises at least one optical element which has a function to shield components having specific wavelengths.
An objective lens system comprising in order from the object side:
- a first lens unit having a negative refractive power;
- and a second lens unit having a positive refractive power, wherein at least one lens element has a function to shield components having specific wavelengths.
An objective lens system comprising:
- a first lens unit which comprises at least one positive lens element and at least one negative lens element including a negative lens element disposed on the object side;
- and a second lens unit which comprises at least one positive lens element, wherein at least one lens element is a radial type gradient index lens element which has a refractive index distribution in a radial direction from an optical axis and wherein at least one lens element has at least one planar surface.
An objective lens system comprising in order from the object side:
- a first lens unit which is composed of a single meniscus lens element and has a negative refractive power;
- and a second lens unit which has a positive refractive power, wherein said meniscus lens element is a radial type gradient index lens element which has a refractive index distribution in a radial direction from an optical axis.
An objective lens system comprising in order from the object side:
- a first lens unit having a negative refractive power;
- and a second lens unit having a positive refractive power, wherein at least one lens element is a radial type gradient index lens element which has a refractive index distribution in a radial direction from an optical axis and wherein a reflecting surface for at least a single reflection is used on the image side of said second lens unit.
An objective lens system comprising in order from the object side:
- a first negative lens unit;
- a reflecting optical element;
- and a second positive lens unit, wherein said objective lens system comprises at least one radial type gradient index lens element which has a refractive index distribution in a radial direction from an optical axis.
An objective lens system comprising:
- a stop;
- a radial type gradient index lens element which has a refractive index distribution in a radial direction from an optical axis;
- and a diffraction type optical element.
An objective lens system comprising:
- a radial type gradient index lens element which has a refractive index distribution in a radial direction from an optical axis;
- and a diffraction type optical element, wherein said diffraction type optical element is disposed on the image side of a stop.
An optical system comprising:
- a radial type gradient index lens element made of a medium which has a refractive index distribution in a radial direction from an optical axis, wherein a stop is disposed in said lens element.
An objective lens system wherein a portion is cut off from an outer circumference of a radial type gradient index lens element which has a refractive index distribution in a radial direction from an optical axis.
An objective lens system wherein an outer circumference of a radial type gradient index lens element is obliquely chamfered and a chamfered portion is held by a lens barrel.
An objective lens system wherein a radial type gradient index lens element has a planar surface on the image side and a solid-state image pickup device is cemented to said planar surface.
An objective lens system wherein a radial type gradient index lens element has a planar surface on the image side and a solid-state image pickup device is kept in close contact with said planar surface.
An objective lens system wherein a member for shielding a light bundle passing through said lens system is disposed toward an optical axis from an outer circumference of a radial type gradient index lens element which has a refractive index distribution in a radial direction from an optical axis.
An objective lens system wherein a radial type gradient index lens element which has a refractive index distribution in a radial direction from an optical axis has a filter function to cut off components having specific wavelengths.
A portable TV telephone wherein at least one radial type gradient index lens element which has a refractive index distribution in a radial direction from an optical axis is used in an optical system.
A portable data input unit wherein at least one radial type gradient index lens element which has a refractive index distribution in a radial direction from an optical axis is used in an optical system.
A portable TV telephone wherein at least one lens element which has at least one aspherical surface is used in an optical system.
A portable data input unit wherein at least one lens element which has at least one aspherical surface is used in an optical system.
A portable TV telephone wherein at least one diffractive optical element is used in an optical system.
A portable data input unit wherein at least one diffractive optical element is used in an optical system.
An objective lens system wherein a diffractive optical element having a negative refractive power is disposed on the object side of a stop.
Dependencies are inferred from the claim text.