72results about How to "Low F-number" patented technology

A folded camera that includes two light folding elements such as prisms and an independent lens system, located between the two prisms, which includes an aperture stop and a lens stack. The lens system may be moved on one or more axes independently of the prisms to provide autofocus and / or optical image stabilization for the camera. The shapes, materials, and arrangements of the refractive lens elements in the lens stack may be selected to capture high resolution, high quality images while providing a sufficiently long back focal length to accommodate the second prism.

A tunable Fabry-Perot filter that is less sensitive to angle of incidence is formed by replacing the cavity (air gap) with a partitioned cavity that has an effective refractive index greater than one. The partitioned cavity includes a pair of partitioned cavity dielectric layers formed on the reflectors on either side of the variable air gap. Each of the dielectric layers has an optical thickness that is less than one fourth the shortest wavelength in the tuning range of the filter. The resulting three-layer partitioned cavity has an effective optical thickness substantially equal to an integral multiple (m) of one half the transmitted wavelength within the tuning range of the filter.

A comparatively low f-number, compact two-group zoom lens that corrects aberrations in the visible and the near-infrared regions includes, in order from the object side, a first lens group of negative refractive power and a second lens group of positive refractive power. The first lens group includes three lens components that are lens elements of negative, negative, negative, and positive refractive power, respectively, in order from the object side. The second lens group includes four lens components that are lens elements of positive, positive, negative, and positive refractive power, respectively, in order from the object side. Aspheric surfaces are disclosed. Certain conditions relating to the focal lengths of the two lens groups, the indexes of refraction, and Abbe numbers of various lens elements are satisfied to control aberrations in both the visible and the near-infrared regions.

A tunable Fabry-Perot filter that is less sensitive to angle of incidence is formed by replacing the cavity (air gap) with a partitioned cavity that has an effective refractive index greater than one. The partitioned cavity includes a pair of partitioned cavity dielectric layers formed on the reflectors on either side of the variable air gap. Each of the dielectric layers has an optical thickness that is less than one fourth the shortest wavelength in the tuning range of the filter. The resulting three-layer partitioned cavity has an effective optical thickness substantially equal to an integral multiple (m) of one half the transmitted wavelength within the tuning range of the filter.

There is provided an imaging lens with excellent optical characteristics which satisfies demand of wide field of view, low profile and low F-number. An imaging lens comprises, in order from an object side to an image side, a first lens with positive or negative refractive power in a paraxial region, a second lens with positive or negative refractive power in a paraxial region, a third lens with positive refractive power in a paraxial region, a fourth lens with negative refractive power in a paraxial region, a fifth lens with positive refractive power in a paraxial region, a sixth lens with positive refractive power in a paraxial region, and a seventh lens with negative refractive power.

Compact lens systems are described that may be used in small form factor cameras. The lens systems may include seven lens elements with refractive power, and may provide low F-numbers with wide field of view while maintaining or improving imaging quality and package size when compared to other compact lens systems. The lens systems may, for example, provide a focal ratio of 1.85 or less, with full field of view of 75 degrees or more. The lens systems may conform to a criterion for compactness TTL / ImageH<1.7, where TTL is the total track length of the lens system, and ImageH is the semi-diagonal image height of the image plane at the photosensor. Lens system parameters and relationships may be selected at least in part to reduce, compensate, or correct for optical aberrations and lens artifacts and effects across the field of view.

There is provided an imaging lens with high-resolution which satisfies demand of the wide field of view, the low-profileness and the low F-number, and excellently corrects aberrations. An imaging lens comprises in order from an object side to an image side, a first lens having a convex surface facing the object side near an optical axis, a second lens, a third lens having negative refractive power near the optical axis, a fourth lens, a fifth lens, a sixth lens, a seventh lens, and an eighth lens having a concave surface facing the image side and the negative refractive power near the optical axis, wherein an image-side surface of said eighth lens is formed as an aspheric surface having at least one pole point in a position off the optical axis, said sixth lens has positive refractive power near the optical axis, an object-side surface of said seventh lens is a convex surface facing the object side near the optical axis, and a below conditional expression (1) is satisfied:0.15<vd7 / vd8<0.55  (1)wherevd7: an abbe number at d-ray of the seventh lens,vd8: an abbe number at d-ray of the eighth lens.

Lens systems are described that may be used in small form factor cameras. An imaging lens system may include a front aperture and five lens elements, and provides a low F-number (<=2.4), wide field of view (>=82 degrees), and short total track length (TTL). Lens system parameters and relationships may be selected at least in part to reduce, compensate, or correct for optical aberrations and lens artifacts and effects across the field of view.

An optical system includes a first light folding element (e.g., a prism), a second light folding element (e.g., another prism or a mirror), and a lens system located between the first light folding element and the second light folding element. In some cases, the lens system includes a lens stack having either four or five lens elements with refractive power. The first light folding element redirects light from an object field from a first axis to the lens system on a second axis. The plurality of refractive lens elements in the lens stack refract the light to the second light folding element. The second light folding element redirects the light from the second axis onto a third axis to form an image of the object field at an image plane. The optical system has a 35 mm equivalent focal length within a range of 85 to 160 mm.

There is provided an imaging lens with excellent optical characteristics which satisfies demand of wide field of view and low F-number. An imaging lens comprising in order from an object side to an image side, a first lens with negative refractive power in a paraxial region, a second lens with positive refractive power having a convex object-side surface in a paraxial region, a third lens with positive refractive power in a paraxial region, a fourth lens, a fifth lens having a concave object-side surface in a paraxial region, and a sixth lens having a concave image-side surface in a paraxial region, and predetermined conditional expressions are satisfied.

A folded camera that includes two light folding elements such as prisms and an independent lens system, located between the two prisms, which includes an aperture stop and a lens stack. The lens system may be moved on one or more axes independently of the prisms to provide autofocus and / or optical image stabilization for the camera. The shapes, materials, and arrangements of the refractive lens elements in the lens stack may be selected to capture high resolution, high quality images while providing a sufficiently long back focal length to accommodate the second prism.

There is provided an imaging lens with high-resolution which satisfies, in well balance, demand of the wide field of view, the low-profileness and the low F-number and excellently corrects aberrations. An imaging lens comprises in order from an object side to an image side, a first lens having negative refractive power, a second lens, a third lens, a fourth lens, and a fifth lens, wherein said second lens has the negative refractive power, and below conditional expressions are satisfied:0.1<T2 / T3<1.169<r3 / r4<20−0.1<r5 / r6<1.4whereT2: distance along an optical axis from an image-side surface of the second lens to an object-side surface of the third lens,T3: distance along the optical axis from an image-side surface of the third lens to an object-side surface of the fourth lens,r3: paraxial curvature radius of an object-side surface of the second lens,r4: paraxial curvature radius of an image-side surface of the second lens,r5: paraxial curvature radius of an object-side surface of the third lens, andr6: paraxial curvature radius of an image-side surface of the third lens.

There is provided an imaging lens with high-resolution which realizes reducing size, the low-profileness, low F-number and small telephoto ratio.An imaging lens comprising in order from an object side to an image side, a first lens having positive refractive power, a second lens, a third lens, a fourth lens, a fifth lens having the positive refractive power, and a sixth lens, wherein a below conditional expression is satisfied:0.6<TTL / f<1.0whereTTL: total track length, andf: focal length of the overall optical system.

There is provided an imaging lens with high-resolution which satisfies demand of wide field of view, low-profileness and low F-number in well balance, and excellently corrects aberrations. An imaging lens comprises, in order from an object side to an image side, a first lens, a second lens having negative refractive power near the optical axis, a third lens having a convex surface facing the image side near the optical axis, a fourth lens and a fifth lens, wherein said first lens has negative refractive power near the optical axis, an image-side surface of said fifth lens has a convex surface facing the image side near the optical axis, and below conditional expressions are satisfied:3.00<(T4 / f)×100<5.900.40<f2 / f5<1.45whereT4: a distance along the optical axis from the image-side surface of the fourth lens to the object-side surface of the fifth lens,f: a focal length of the overall optical system of the imaging lens,f2: a focal length of the second lens,f5: a focal length of the fifth lens.

Compact lens systems are described that may be used in small form factor cameras. The lens system may include six lens elements with refractive power, and may provide low F-numbers with wide field of view while maintaining or improving imaging quality and package size when compared to other compact lens systems. The lens system may, for example, provide a focal ratio of 2.1 or less (e.g., 1.8), with full field of view within a range of 70 to 90 degrees (e.g., 81 degrees). The lens system may conform to a criterion for compactness TTL / ImageH<1.7, where TTL is the total track length of the lens system, and ImageH is the semi-diagonal image height on the image plane at the photosensor. Lens system parameters and relationships may be selected at least in part to reduce, compensate, or correct for optical aberrations and lens artifacts and effects across the field of view.

A zoom lens and a photographing apparatus having the zoom lens including a first lens group having a positive refractive power; a second lens group having a negative refractive power; a third lens group having a positive refractive power; and a fourth lens group having a positive refractive power, wherein the first lens group, the second lens group, the third lens group, and the fourth lens group are arranged sequentially from an object side, wherein the second lens group includes a first aspherical lens having a negative refractive power, and a second aspherical lens having a positive refractive power.

There is provided an imaging lens with excellent optical characteristics which satisfies demand of a low profile and a low F-number. An imaging lens comprises in order from an object side to an image side, a first lens with positive refractive power having an object-side surface being convex in a paraxial region, a second lens with negative refractive power having an object-side surface being convex in a paraxial region, a third lens with negative refractive power having an image-side surface being concave in a paraxial region, a fourth lens with positive refractive power in a paraxial region, and a fifth lens with negative refractive power having an object-side surface being concave in a paraxial region, and predetermined conditional expressions are satisfied.

An imaging lens includes an aperture stop and an optical assembly which includes: in order from an object side to an image side: a first lens element with a positive refractive power having a convex aspheric object-side surface and a concave aspheric image-side surface; a plastic second lens element with a positive refractive power having an aspheric object-side surface and a concave aspheric image-side surface; a plastic third lens element with a positive refractive power having aspheric object-side and image-side surfaces; a fourth lens element with a negative refractive power having a concave object-side surface and a convex image-side surface; a plastic fifth lens element with a positive refractive power having a convex aspheric object-side surface, a concave aspheric image-side surface and more than one inflection point. The imaging lens satisfies the following conditions: 0.3<(R5+R6) / (R5−R6)<1.15 and 1.2<TL / ImgH<1.65.

There is provided an imaging lens with excellent optical characteristics which satisfies demand of the wide field of view, the low-profileness and the low F-number. An imaging lens comprises, in order from an object side to an image side, a first lens having a convex surface facing the object side and positive refractive power near an optical axis, a second lens having negative refractive power near the optical axis, a third lens having aspheric surfaces on both sides, a fourth lens, and a fifth lens having a concave surface facing the image side and the negative refractive power near the optical axis, wherein an image-side surface of said fifth lens is formed as an aspheric surface having at least one pole point in a position off the optical axis, and predetermined conditional expressions are satisfied:

There is provided an imaging lens with excellent optical characteristics which satisfies demand of wide field of view, low-profileness and low F-number. An imaging lens comprises, in order from an object side to an image side, a first lens with positive refractive power having an object-side surface being convex in a paraxial region, a second lens with negative refractive power in a paraxial region, a third lens, a fourth lens being a double-sided aspheric lens, a fifth lens, a sixth lens having an image-side surface being concave in a paraxial region, and a seventh lens with negative refractive power having an image-side surface being concave in a paraxial region, wherein the image-side surface of the seventh lens is an aspheric surface having at least one pole point in a position off the optical axis, and predetermined conditional expressions are satisfied.

There is provided an imaging lens with high-resolution which realizes the wide field of view, low-profileness, and low F-value in well balance, and proper correction of aberrations.An imaging lens comprising in order from an object side to an image side, a first lens having a convex surface facing the object side near an optical axis and negative refractive power, a second lens having negative refractive power, a third lens, a fourth lens having biconvex shape near the optical axis, and a fifth lens, wherein each lens of the first lens to the fifth lens is arranged without being cemented, and a below conditional expression (1) is satisfied:0.50<r5 / r6<12.50  (1)wherer5: curvature radius of the object-side surface of the third lens, andr6: curvature radius of the image-side surface of the third lens.

There is provided an imaging lens with excellent optical characteristics which satisfies demand of low-profileness and low F-number. An imaging lens comprises, in order from an object side to an image side, a first lens with positive refractive power having an object-side surface being convex in a paraxial region, a second lens with negative refractive power in a paraxial region, a third lens with negative refractive power in a paraxial region, a fourth lens with positive or negative refractive power having an object-side surface being convex in a paraxial region, a fifth lens with positive or negative refractive power in a paraxial region, and a sixth lens with positive or negative refractive power having an image-side surface being convex in a paraxial region, and predetermined conditional expressions are satisfied.

There is provided a compact imaging lens which meets demand of low-profileness, reduction in telephoto ratio and low F-number, and properly corrects aberrations. An imaging lens comprising in order from an object side to an image side, a first lens, a second lens, a third lens, a fourth lens having a convex surface facing the image side near an optical axis, and a fifth lens having positive refractive power, wherein a below conditional expression (1) is satisfied:0.64<TTL / f<1.0  (1)wheref: focal length of the overall optical system of the imaging lens, andTTL: distance along the optical axis from an object-side surface of the first lens to an image plane.

There is provided an imaging lens which satisfies demand of the wide field of view, the low-profileness and the low F-number and has excellent optical performance. An imaging lens comprises, in order from an object side to an image side, a first lens having positive refractive power and a convex surface facing the object side near an optical axis, a second lens having the convex surface facing the object side near the optical axis, a third lens, a fourth lens, a fifth lens, and a sixth lens having negative refractive power and a concave surface facing an image side near the optical axis, wherein the second lens has negative refractive power near the optical axis, the third lens has the negative refractive power near the optical axis, the fourth lens has the positive refractive power near the optical axis, and below conditional expressions are satisfied:−3.00<(D2 / f2)×100<−0.050.25<(T4 / f)×100<1.00whereD2: thickness along the optical axis of the second lens,f2: focal length of the second lens,T4: distance along the optical axis from the image-side surface of the fourth lens to the object-side surface of the fifth lens, andf: focal length of the overall optical system of the imaging lens.

There is provided an imaging lens with excellent optical characteristics which satisfies demand of wide field of view, low-profileness and low F-number in well balance.An imaging lens comprises in order from an object side to an image side, a first lens, a second lens, a third lens, a fourth lens having a concave surface facing the object side near an optical axis, a fifth lens, and a sixth lens having the concave surface facing the image side near the optical axis and negative refractive power, wherein said second lens has a convex surface facing the object side near the optical axis, composite refractive power of said second lens, said third lens and said fourth lens is negative, and below conditional expressions (1) and (2) are satisfied:0.85<vd1 / (vd2+vd3)<1.95  (1)0.15<vd5 / vd6<0.55  (2)wherevd1: abbe number at d-ray of the first lens,vd2: abbe number at d-ray of the second lens,vd3: abbe number at d-ray of the third lens,vd5: abbe number at d-ray of the fifth lens, andvd6: abbe number at d-ray of the sixth lens.

There is provided an imaging lens with excellent optical characteristics which satisfies demand of a low profile and a low F-number. An imaging lens comprises in order from an object side to an image side, a first lens with negative refractive power having an object-side surface being convex in a paraxial region, a second lens with positive refractive power in a paraxial region, a third lens with the negative refractive power in a paraxial region, a fourth lens with the positive refractive power in a paraxial region, a fifth lens having a flat object-side surface and a flat image-side surface that are aspheric, and a sixth lens with the negative refractive power having an image-side surface being concave in a paraxial region.

There is provided an imaging lens with high-resolution which satisfies demand of the wide field of view, the low-profileness and the low F-number, and has excellent optical characteristics. An imaging lens comprises in order from an object side to an image side, a first lens having a convex surface facing the object side near an optical axis and positive refractive power, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, and a seventh lens having a concave surface facing the image side near the optical axis and negative refractive power, wherein an image-side surface of said seventh lens is formed as an aspheric surface having at least one pole point in a position off the optical axis, said second lens has positive refractive power near the optical axis, and said sixth lens has plane surfaces both on the object side and the image side and is formed as a double-sided aspheric lens.

There is provided an imaging lens which satisfies demand of the wide field of view, the low-profileness and the low F-number and has excellent optical performance. An imaging lens comprises, in order from an object side to an image side, a first lens having positive refractive power and a convex surface facing the object side near an optical axis, a second lens having the convex surface facing the object side near the optical axis, a third lens, a fourth lens, a fifth lens, and a sixth lens having negative refractive power and a concave surface facing an image side near the optical axis, wherein the second lens has negative refractive power near the optical axis, the third lens has the negative refractive power near the optical axis, the fourth lens has the positive refractive power near the optical axis, and below conditional expressions are satisfied:−3.00<(D2 / f2)×100<−0.050.25<(T4 / f)×100<1.00whereD2: thickness along the optical axis of the second lens,f2: focal length of the second lens,T4: distance along the optical axis from the image-side surface of the fourth lens to the object-side surface of the fifth lens, andf: focal length of the overall optical system of the imaging lens.