136results about How to "Corrected spherical aberration" patented technology

An imaging lens comprises, in order from an object side: a first lens that has a negative refractive power and is convex toward the object side; a second lens that has a positive refractive power and is a meniscus lens convex toward the object side; a stop; a third lens that has a positive refractive power and is convex toward an image side; and a cemented lens that has a positive refractive power as a whole and is formed by cementing a fourth lens and a fifth lens, wherein assuming that an Abbe number of the second lens with respect to d-line is ν2, a distance on an optical axis from a vertex of a surface of the first lens facing toward the object side to an image plane of the imaging lens is L, a focal length of the imaging lens is f, and a back focus of the imaging lens is Bf, the following conditional expressions (1) to (3) are satisfied:ν2>30  (1),2.5<L / f<4.0  (2), and0.5<Bf / f<1.3  (3).

This invention provides an optical image lens system comprising: a positive first lens element having a convex object-side surface; a second lens element; a positive third lens element; a fourth lens element; a positive plastic fifth lens element having a convex object-side surface and a concave image-side surface, at least one of the object-side and image-side surfaces is aspheric; and a negative plastic sixth lens element having a concave image-side surface, at least one of the object-side and image-side surfaces is aspheric, wherein the shape of the image-side surface changes from concave at the paraxial region thereof to convex while away from the paraxial region thereof.

An optical 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 a convex object-side surface. The object-side surface and the image-side surface of the fifth lens element are aspheric and at least one of the object-side surface and the image-side surface has at least one inflection point formed thereon. The sixth lens element with negative refractive power has a concave object-side surface and a convex image-side surface, wherein the object-side surface and the image-side surface of the sixth lens element are aspheric.

An image capturing optical lens system 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 a convex object-side surface. The second lens element has negative refractive power. The third lens element has refractive power. The fourth lens element has refractive power, wherein at least one surface of the fourth lens element is aspheric. The fifth lens element with negative refractive power has a concave object-side surface and a convex image-side surface, and the surfaces thereof are aspheric. The sixth lens element with refractive power has an image-side surface changing from concave at a paraxial region thereof to convex at a peripheral region thereof, and the surfaces thereof are aspheric.

A projection lens system that projects projected light from a light modulator to a screen, comprising in order from a screen side: a first lens group with a negative refractive power; a second lens group with a positive refractive power; and a third lens group with a positive refractive power is provided. The third lens group includes at least two cemented lenses and a lens with a positive refractive power positioned on an opposite side of the cemented lenses to the screen. Since the projection lens system achieves a sufficiently high correcting performance for various aberrations using fewer aspherical lenses, it is suitable lens system for a rear projector with high image quality.

A liquid crystal lens element having a lens function capable of stably correcting spherical aberration containing a power component corresponding to focus change of incident light according to the magnitude of applied voltage.The liquid crystal lens element comprises a pair of transparent substrates 11 and 12, one (12) of the transparent electrodes is provided with a transparent electrode 15 and a Fresnel lens surface 17, and the other one (11) of the pair of transparent electrodes is provided with a phase correction surface 18 and a transparent electrode 16. Thus, by disposing a Fresnel lens surface 17 and a liquid crystal layer 13 between a pair of transparent electrodes 15 and 16, it becomes possible to change substantial refractive index distribution of the liquid crystal layer 13 according to the magnitude of applied voltage, and to add a positive or negative power to a wavefront transmitted through the liquid crystal layer 13, the Fresnel lens surface 17 and the phase correction surface 18.

A liquid crystal lens element having a lens function is provided, which is small sized without having moving part, and which can stably carry out correction of spherical aberration containing a power component corresponding to focal point change of incident light.A liquid crystal lens element which changes a focal length of light transmitted through a liquid crystal 16 according to the magnitude of the voltage applied to the liquid crystal 16 sandwiched between a pair of transparent substrates 11 and 12, which comprises transparent electrodes 13 and 14 provided on the respective transparent substrates 11 and 12 for applying a voltage for the liquid crystal 16, and a concave-convex portion 17 having a saw-tooth-shaped cross-sectional shape having a rotational symmetry about an optical axis and formed on one surface of the transparent electrode 13 with a transparent material, wherein at least concave portions of the concave-convex portion 17 are filled with the liquid crystal 16 so as to change the substantial refractive index of the liquid crystal 16 according to the magnitude of applied voltage.

A photographing optical lens 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 has positive refractive power. The second lens element, the third lens element, and the fourth lens element have refractive power. The fifth lens element with negative refractive power has an aspheric object-side surface and an aspheric image-side surface being concave in a paraxial region thereof. The sixth lens element with negative refractive power has an aspheric object-side surface being concave in a paraxial region thereof and an aspheric image-side surface being concave in a paraxial region thereof, wherein the image-side surface thereof has at least one inflection point. The photographing optical lens further includes a stop located between an object and the second lens element.

A three piece type optical lens includes a first lens element with positive refractive power, a second lens element with negative refractive power, a third lens element with negative refractive power, an IR cut-off filter and an image sensor arranged along an optical axis in sequence from an object side. The first lens element and the second lens element are both meniscus aspherical lens while a convex surface of the first lens element is on the object side and a convex surface of the second lens is on the image side. The third lens element is an M-shaped aspherical lens whose object side and image side are both M-shaped and a central surface of the optical axis can be a convex surface or a concave surface. A pre-aperture is disposed or a center-aperture is arranged on the optical lens.