76results about How to "Various aberration" patented technology

An optical lens system for taking image comprises, in order from the object side to the image side: a first lens element with positive refractive power; a second lens element with negative refractive power; a third lens element with negative refractive power having a convex object-side surface and a concave image-side surface; a fourth lens element with negative refractive power being provided with at least one aspheric surface. In the optical lens system for taking image, the number of lens elements with refractive power is limited to four. Such arrangements can reduce the volume and the sensitivity of the optical lens system while providing higher resolution.

There is provided an image pickup lens having a 6-element structure which has a small size and a sufficiently lens speed of F/2 or less and in which various aberrations are corrected favorably. This image pickup lens includes a first lens having a positive refractive power and comprising a convex surface directed to the object side; a second lens having a negative refractive power and comprising a concave surface directed to the image side; a third lens having a positive or negative refractive power; a fourth lens having a positive refractive power; a fifth lens having a positive refractive power and comprising a convex surface directed to the image side; and a sixth lens having a negative refractive power and comprising a concave surface directed to the image side, in this order from the object side, wherein the image side surface of the sixth lens has an aspherical shape and an inflection point at a position other than an intersection point with the optical axis, and the image pickup lens satisfies the following conditional expressions.

ν1>50

ν2≦30

where,

• • ν1 is an Abbe number of the first lens, and
  • ν2 is an Abbe number of the second lens.

An image capturing lens assembly includes, in order from an object side to an image side, a first lens element, a second lens element, a third lens element, a fourth lens element, a fifth lens element and a sixth lens element. The first lens element with positive refractive power has an object-side surface being convex in a paraxial region thereof. The second lens element has negative refractive power. The third lens element has refractive power. The fourth lens element has refractive power. The fifth lens element with refractive power has two surfaces being both aspheric, wherein at least one of the surfaces of the fifth lens element has at least one inflection point thereon. The sixth lens element with positive refractive power has an image-side surface being convex in a paraxial region thereof, wherein the surfaces of the sixth lens element are both aspheric.

At least one exemplary embodiment is directed to an optical system which includes a plurality of refractive optical elements arranged substantially symmetrically with respect to an aperture-stop. Furthermore the optical system comprises a refractive optical element being constituted by a solid material. An Abbe number νd of the solid material and a partial dispersion ratio θgF of the solid material can satisfy the following conditions:

θgF−(−1.665×10⁻⁷·νd³+5.213×10⁻⁵·νd²−5.656×10⁻³·νd+0.755)>0,

θgF−(−1.665×10⁻⁷·νd³+5.213×10⁻⁵·νd²−5.656×10⁻³·νd+1.011)<0.

An image-capturing lens has, in order from an object, an object side lens group G1 and an image side lens group G2 which is disposed next to the object side lens group G1 with an air space, and focusing is performed from a distant object to a close object by moving at least a part of the image side lens group G2 along an optical axis as a focusing lens group, and image stabilization is performed by moving at least a part of the image side lens group G2 as a shift lens group so as to have components roughly orthogonal to the optical axis.

The present disclosure provides an imaging optical lens assembly, including, in order from an object side to an image side: a first lens element with negative refractive power having an object-side surface being concave in a paraxial region, a second lens element with positive refractive power, a third lens element with negative refractive power, a fourth lens element with positive refractive power, and a fifth lens element with negative refractive power having an image-side surface being concave in a paraxial region and at least one convex shape in an off-axial region on the image-side surface, wherein the imaging optical lens assembly has a total of five lens elements.

An imaging lens includes: a first lens group; an aperture stop; and a second lens group having a positive refractive power, in this order from an object side. The first lens group includes a negative first lens provided most toward the object side. The second lens group includes a positive lens, provided most toward an imaging surface, and a negative lens having a concave surface and an aspherical surface at least toward the object side. The following Conditional Formulae are satisfied:

0.03<(|Sagsp1|−|Sagas1|)/Re1<0.35; and

1.819≦NdAB

• • wherein Sagsp1 is the sag of a reference spherical surface at the edge of the effective diameter of the object side surface of the negative lens, Sagas1 is the sag of the aspherical surface of the lens, Re1 is the effective diameter of the object side surface of the lens, and NdAB is the average refractive index of the positive lens and the negative lens.

An optical pickup apparatus for performing recording, reproduction and deletion of information onto each of three types of optical recording mediums including light sources of a blue wavelength zone, light sources of a red wavelength zone and light sources of an infrared wavelength zone. The optical pickup apparatus also has a single object lens which condenses a light from any of the light sources and a single aberration correction device disposed in a common light path between each of the light sources and the object lens.

Provided are a zoom lens and an imaging apparatus using the zoom lens, the zoom lens being suited for achieving compactness without increasing the number of lenses and being capable of implementing motion blur compensation. The zoom lens includes lenses arranged in order from an object side into a first lens group having positive refractive power, a second lens group having negative refractive power, a third lens group having positive refractive power, a fourth lens group having positive refractive power, and a fifth lens group having positive refractive power. In the event of a shift of a lens position mode from a wide angle end mode to a telephoto end mode, the first lens group is fixed along an optical axis direction, the second lens group moves to an image side, the third lens group is fixed along the optical axis direction, the fourth lens group compensates for a fluctuation in an image plane position due to the shift of the second lens group, and concurrently moves along the optical axis direction in a close-distance focusing event, and the fifth lens group is fixed along the optical axis direction. An aperture diaphragm is disposed in the vicinity of the third lens group. The fifth lens group includes a negative sub lens group having negative refractive power and a positive sub lens group having a positive refractive power, wherein the image can be shifted in conjunction with a shift of the positive sub lens group in a direction substantially perpendicular to the optical axis. The zoom lens satisfies conditional equation (1) given as 0.6<f5p/Da<1.4, where f5p is a focal distance of the positive sub lens group disposed in the fifth lens group, and Da is a length extending along the optical axis to a paraxial image position from a most-imagewise surface of the positive sub lens group disposed in the fifth lens group.

Providing a zoom lens system having excellently correcting various aberrations with accomplishing to be compact, lightweight, and slim upon being retracted. The system is composed of, in order from an object, a first group having negative refractive power, and a second group having positive refractive power. Upon zooming from a wide-angle end state to a telephoto end state, a distance between the first group and the second group varies. The first group is composed of two lens elements which are, in order from the object, a negative lens having a concave surface facing an image, and a positive lens. The second group consists of three lens elements or less and includes, in order from the object, a positive lens, an aperture stop for defining an f-number, and a negative lens component including a negative lens and disposed to the image side of the aperture stop. Given conditions are satisfied.

An optical lens system for taking image comprises, in order from the object side to the image side: an aperture stop; a first lens element with positive refractive power having a convex object-side surface and a convex image-side surface; a plastic second lens element with negative refractive power having a concave object-side surface, a convex image-side surface and at least one aspheric surface; a plastic third lens element with negative refractive power having a convex object-side surface, a concave image-side surface and at least one aspheric surface. The number of the lens elements with refractive power being limited to three. Focal lengths of the optical lens system, the first lens element, the second lens element and the third lens element are f, f1, f2, f3 respectively; Abbe numbers of the first and second lens elements are V1, V2 respectively, an on-axis distance between second and third lens elements is T23, and they satisfy the relations: 0.8<f/f1<1.8; 0<|f/f2|<0.8; 0<|f/f3|<0.7; 20<V1−V2<38; 0.13<T23/f<0.21.

A subminiature imaging optical system includes a first lens including a first lens part having a convex object-side surface, a second lens part having an object-side surface in contact with an image-side surface of the first lens part, and a third lens part having an object-side surface in contact with an image-side surface of the second lens part and a concave image-side surface, about the optical axis; and a second lens including a fourth lens part having an object-side surface with a convex center and a concave peripheral portion about the optical axis, a fifth lens part having an object-side surface in contact with an image-side surface of the fourth lens part, and a sixth lens part having an object-side surface in contact with an image-side surface of the fifth lens part, and an image-side surface with a concave center and a convex peripheral portion about the optical axis.

An optical system includes a first lens unit having a negative refractive power and a second lens unit having a positive refractive power. The second lens unit includes a front lens unit, a stop, and a rear lens unit. The front lens unit includes a biconvex positive lens located closest to the image side. A back focus during focusing on an infinitely-distant object point (BF), a focal length of the entire optical system (f), a focal length of the positive lens of the front lens unit located closest to the image side (fp), a focal length of the front lens unit (f2a), a refractive power of a surface of the rear lens unit located closest to the object side (φf), and a refractive power of the entire optical system (φ) satisfy the following conditions:

1.0<BF/f<3.0

0.1<fp/f2a<0.5

0.7<|φf/φ|<1.5.

An optical lens system for taking image comprises, in order from the object side to the image side: a first lens element with positive refractive power has a convex object-side surface; a plastic second lens element with negative refractive power has a concave object-side surface and is provided with at least one aspheric surface; a plastic third lens element with negative refractive power has a concave object-side surface and is provided with at least one aspheric surface; a fourth lens element with positive refractive power has a concave image-side surface and is formed with inflection points; and an aperture stop is located between an object to be photographed and the second lens element. An on-axis distance between the first and second lens elements is T12, a focal length of the optical lens system for taking image is f, they satisfy the relation: (T12/f)*100>0.7.

A projection lens includes, in order form a magnification side: a first lens group having negative refractive power; and a second lens group having positive refractive power. An aspheric lens is arranged on the most magnification side of the first lens group. The conditional expressions 3<Bf/f and 0.4<H/L are satisfied, where f denotes a focal length of the projection lens, Bf denotes an air-converted back focal length, H denotes a height of a principal ray at the maximum angle of view on a plane which is orthogonal to an optical axis and which passes through point A, and L denotes a length from the point A to a vertex of a lens surface on the most reduction side on the optical axis. Here, the point A is a vertex of a lens surface on the most magnification side on the optical axis.

At least one exemplary embodiment is directed to A retro focus optical system that is capable of sufficiently correcting and/or reducing various aberrations including the chromatic aberration. The optical system includes a refractive optical element including a solid material. The Abbe number νd and the partial dispersion ratio θgF of the solid material along with a shape of the refractive optical element can reduce various aberrations.

A zoom lens system consists, in order from an object side to an image-forming side, of a first negative lens group G1, a second positive lens group G2, and a third positive lens group G3. The first lens group G1 consists of one negative lens and one positive lens, the second lens group G2 consists of a cemented lens composed of a positive lens and a negative lens, and one meniscus lens that is concave on the image-forming side, the third lens group G3 consists of a single positive lens, and a combined focal length f2 of the second lens group, a focal length Lf23 of the meniscus lens of the second lens group, a combined focal length fw of the zoom lens system at a wide angle end, a combined focal length f3 of the third lens group, a radius of curvature Ro of an object side surface of the positive lens in the cemented lens, and a radius of curvature Ri of an image-forming side surface of the positive lens in the cemented lens satisfy the following conditions.

0<|f2/Lf23|<0.3

−2.0<Ri/Ro<−1.0

0.25<fw/f3<0.45

A variable-magnification optical system has a plurality of lens groups that image a light beam from the object side on an image sensor, an optical aperture stop that intercepts part of the light beam heading for the image sensor, and a reflective mirror that changes the optical axis of the light beam of which part has been intercepted by the optical aperture stop. The plurality of lens groups include at least lens groups arranged in a positive-negative-positive-positive optical power arrangement, and at least two of the lens groups are moved for zooming from the wide-angle end to the telephoto end. The variable-magnification optical system fulfills a prescribed conditional formula.

A zoom lens wherein the image plane movement upon lens shifting is minimized. A power variation section and a final lens group are disposed in order from an object side. The power variation section includes at least two lens groups movable in an optical axis direction to vary a lens position state. The final lens group is fixed in the optical axis direction and includes first to third sub groups having negative, positive and positive refracting powers and disposed in order from the object side. The second sub group is shiftable substantially perpendicularly to the optical axis to shift an image. A conditional expression 0.2<ft/fBt<0.8 is satisfied where ft and fBt are the focal distances of the lens system and entire lens groups disposed on the object side of the third sub group in the telephoto end state.