41results about How to "Small F value" patented technology

The invention provides an imaging lens that has a small F number and a small size while maintaining a good optical performance. The 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 nu2, 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: nu2>30 (1), 2.5 G02B 13 / 00 G02B 9 / 34 H04N 5 / 225 8 18 3 2008 / 8 / 15 101373260 2009 / 2 / 25 000000000 Fujinon Corp. Japan Asami Taro li xianglan 11021 The Patent Agency of the Chinese Academy of Sciences Inside the Chinese Academy of Sciences, No.52 Sanlihe Road, Fuwai, Beijing 100864 Japan 2007 / 8 / 21 2007-214271

An imaging lens includes five lenses for a solid-state image sensor, arranged in order from the object side to the image side, a first lens with positive refractive power having a convex object side surface, a second lens with negative refractive power having a concave image side surface, a third lens with positive or negative refractive power, a fourth lens with positive refractive power as a double-sided aspheric lens having a concave image side surface near an optical axis, and a fifth lens with negative refractive power as a double-sided aspheric lens having a concave image side surface near the optical axis, wherein the first lens and second lens satisfy conditional expressions below:45<ν1<90  (1)22<ν2<35  (2)2.0<ν1 / ν2<2.6  (3)whereν1: first lens Abbe numberν2: second lens Abbe number.

There is provided an imaging lens which is low-profile, has a small f-value, and obtains wide field of view which aberrations are properly corrected, in order from an object side to an image side, comprising a first lens having positive refractive power and a convex surface on an object side near an optical axis, a second lens having negative refractive power and a concave surface on the object side near the optical axis, a third lens having positive refractive power and a convex surface on the image side as a double-sided aspheric lens and a fourth lens having negative refractive power and a concave surface on an image side near the optical axis as a double-sided aspheric lens, wherein a conditional expression (1) below is satisfied:8.5<ih / f<1.0  (1)where f denotes the focal length of the overall optical system, and ih denotes maximum image height.

An image pickup lens includes an aperture stop, a first lens with positive refractive power having a convex object-side surface, a second lens with negative refractive power having a concave image-side surface, a third lens with positive refractive power having a convex image-side surface, a fourth lens with negative refractive power as a double-sided aspheric lens having a concave object-side surface, and a fifth lens with negative refractive power of a meniscus shape as a double-sided aspheric lens having a concave image-side surface, wherein the fifth lens is designed so that the negative refractive power weakens as the distance from the optical axis increases, and wherein the following conditional expression (1) is satisfied:0.55<f1 / f<1.0  (1)where f represents a focal length of an overall image pickup lens, and f1 represents a focal length of the first lens.

An imaging lens includes, from the object side to the image side, an aperture stop, a first lens with positive refractive power having a convex object-side surface near an optical axis, a second lens with positive refractive power having a convex image-side surface near the axis, a third lens with positive refractive power having a convex image-side surface near the axis, and a fourth lens with negative refractive power having a concave image-side surface near the axis, wherein all lens surfaces are aspheric, all lenses are made of plastic material, a diffractive optical surface is formed on at least one of the lens surfaces from the first lens image-side surface to the second lens image-side surface, and at least one of the three positive lenses satisfies expression (1):1.58<Ndi  (1)whereNdi: refractive index of the i-th positive lens at d-ray.

Arranged in order from an object side are: an aperture stop; a positive (refractive power) first lens having convex object-side and image-side surfaces; a double-sided aspheric negative second lens having a concave object-side surface; a meniscus double-sided aspheric positive third lens having a convex image-side surface; and a meniscus double-sided aspheric negative fourth lens having a concave image-side surface. All the lenses are made of plastic material and conditional expressions below are satisfied:0.56<r1 / f<1.10  (1)0.86<f1 / f3<1.41  (2)−5.0<r3 / r4<0.1  (3)2.0<r7 / r8<4.8  (4)wheref: focal length of the imaging lens overall optical systemf1: first lens focal lengthf3: third lens focal lengthr1: curvature radius of the first lens object-side surface P1 r3: curvature radius of the second lens object-side surface P1 r4: curvature radius of the second lens image-side surface P1 r7: curvature radius of the fourth lens object-side surface P1 r8: curvature radius of the fourth lens image-side surface.

The present invention provides small F-measure, wide-angle and compact structure, from the center of the Ministry of the imaging area to the imaging regions of the periphery so far will be able to get a good image of the camera lens, and imaging apparatus equipped with the camera lens. The camera lens (1) in order from the object side substantially from the concave toward the image side of the negative first lens (L1), a positive second lens convex toward the image side (L2), a third negative lens concave toward the image side (L3), biconvex positive fourth lens shape (L4), positive the fifth lens is biconvex shape (L5), a sixth negative lens concave toward the object side (L6) formed. The imaging lens (1) satisfies the conditional formula relating to the radius of curvature (R3) of the object side of the second lens (L2) and the focal length (f) of the whole system (1): R3 / F < 0.

The invention provides a zoom optical system and a shooting device. The zoom optical system realizes small size, low cost, relatively low F value, good chrominance correction and high optical performance. The zoom optical system successively comprises, from the object side, a positive first lens group (G1) which is fixed during the zooming, a second lens group (G2) which is moved along an optical axis so as to perform the zooming, a diaphragm which is fixed during the zooming, a positive third lens group (G3) which is fixed during the zooming, and a positive fourth lens group (G4) which corrects the image plane position and focuses along with the zooming operation. The second lens group (G2) successively comprises, from the object side, a negative lens, a positive meniscus lens with a concave surface being oriented to the object side, a biconcave lens and a positive lens. The zoom optical system is configured in such a manner to satisfy the prescribed conditions related to the focal length of the second lens group (G2), the Abbe number of the positive meniscus lens of the second lens group (G2) and the amount of movement of the second lens group (G2) during the zooming from the wide end to the tele end.

An imaging lens is provided and includes: in order from the object side, a first lens group including a biconcave lens; a second lens including two lenses whose convex surfaces are arranged opposite to each other and having a positive refractive power as a whole; a third lens group including a biconcave lens; and a fourth lens group including two lenses whose convex surfaces are arranged opposite to each other and having positive refractive power, as a whole, the imaging lens satisfying the specific condition.

The invention provides a zoom lens and an image pickup apparatus using the same. The zoom lens includes in order from an object side, 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, a fourth lens group having a positive refractive power, and a last lens group having a positive refractive power, and at the time of zooming from the wide angle end to the telephoto end, the first lens group is fixed, the second lens group moves toward a side of an image plane, the third lens group is fixed, and the fourth lens group moves, and at the time of focusing, the fourth lens group moves. The zoom lens satisfies the following conditional expression (101), (108'') and (117''): 0.20<log([beta]34T / [beta]34W)<0.9log [gamma](101), -0.15<f2<f1<-0.06 (108''), and 0.76<the absolute value of [beta]FW<0.90 (117'').

The invention provides a pick-up lens which has a small F value, a wide angle, is compact, and can acquire good images from a center of an image forming region to a periphery portion of the image forming region, and a pick-up device having the pick-up lens. The pick-up lens (1) substantially includes, from an object side, a negative first lens (L1) having an concave surface facing an image side, a positive second lens (L2) having a convex surface facing the image side, a negative third lens (L3) having a concave surface facing the image side, a dual-concave positive fourth lens (L4), a dual-convex positive fifth lens (L5), and a negative sixth lens having a concave surface facing the object side successively. The pick-up lens (1) meets a conditional expression associated with a synthetized focal length (f12) of the first lens (L1) and the second lens (L2) and the focal length (f) of the whole system: -5<f12 / f<-2.

The present disclosure provides a zoom lens having a small F value throughout the entire zoom range, which favorably corrects various aberrations, and exhibits small fluctuations in aberrations during focusing operations. The present disclosure also provides an imaging apparatus equipped with such a zoom lens. The zoom lens includes, in order from the object side: a positive first lens group (G1); a negative second lens group (G2); a positive third lens group (G3); a negative fourth lens group (G4); and a positive fifth lens group (G5). The distance between the first and second lens groups constantly increases, the distance between the second and third lens groups constantly decreases, the distance between the third and fourth lens groups constantly changes, and the distance between the fourth and fifth lens groups constantly increases when changing magnification from the wide angle to the telephoto end. The first lens group includes, in order from the object side, a negative lens, a positive lens, and a positive lens. The fourth lens group includes, in order from the object side, a negative lens, a negative lens, and a positive lens, and moves toward the image side when focusing from a far distance to a close distance.

The present invention relates to a zoom lens, a photographic device using the zoom lens, and image transmission device and system, wherein the zoom lens is characterized by comprising, from an object side, a first lens set with a positive refractive power, a second lens set with a negative refractive power, a third lens set with a negative refractive power, a fourth lens set with a positive refractive power, a fifth lens with a positive refractive power, and a final lens set with a positive refractive power, and when the zoom lens is zoomed from a wide angle end to a telescopic end, the second lens set and the third lens set move, and one of the fourth, fifth and final lens sets moves.

The invention provides an imaging lens and an imaging apparatus having the imaging lens. While suppressing an increase in the diameter of focusing groups, the imaging lens that has a wide angle of view and a small F-number, and is able to focus on an object at close distance without increasing the size of the lens system, and is able to maintain excellent performance. The imaging lens includes, consecutively in order from the most object-side, a positive first lens group (G1), a positive second lens group (G2) and a third lens group (G3). Focusing on an object at close distance from a state of having focused on an object at infinity is performed by moving the second lens group (G2) and the third lens group (G3) in such a manner that a distance between the second lens group (G2) and the third lens group (G3) changes while the first lens group (G1) is fixed. The first lens group (G1) includes, consecutively in order from the most object-side, a negative first lens (L11) and a negative second lens (L12).

An image pickup lens includes an aperture stop, a first lens with positive refractive power having a convex object-side surface, a second meniscus lens having a concave image-side surface, a third meniscus lens having a convex image-side surface, a fourth meniscus lens having a concave object-side surface near an optical axis, and a fifth meniscus lens having a concave image-side surface near the optical axis, wherein the image-side surface of the fourth lens has an aspherical shape in which a positive refractive power weakens toward the periphery, and wherein the following conditional expressions (1) and (7) are satisfied:0.55<f1 / f<1.0  (1)−1.6<f2 / f<−0.7  (7)where f represents a focal length of an overall image pickup lens, f1 represents a first lens focal length, and f2 represents a second lens focal length.

The present disclosure provides a zoom lens having a wide angle of view at the wide angle end, a small F value throughout the entire zoom range, which favorably corrects various aberrations. The present disclosure also provides an imaging apparatus equipped with such a zoom lens. The zoom lens is constituted by, in order from the object side: a positive first lens group (G1); a negative second lens group (G2); a positive third lens group (G3); a negative fourth lens group (G4); and a positive fifth lens group (G5). The distance between the first and second lens groups constantly increases, the distance between the second and third lens groups constantly decreases, the distance between the third and fourth lens groups constantly changes, and the distance between the fourth and fifth lens groups constantly increases when changing magnification from the wide angle end to the telephoto end. The first lens group (G1) is constituted by three lenses, which are negative, positive, and positive in order from the object side. The second lens group is constituted by five lenses, which are negative, negative, positive, positive, and negative in order from the object side. The fifth lens group is constituted by a single lens component.

A zoom lens is equipped with: a first lens group, which is fixed when changing magnification, provided most toward the magnification side; and a second lens group having a positive refractive power, which moves when changing magnification, provided adjacent to the first lens group at the reduction side thereof. The first lens group is constituted essentially by, in order from the magnification side to the reduction side, a front group having a positive refractive power and a rear group having a negative refractive power. Focusing operations are performed by changing the distance between the front group and the rear group. Conditional Formula (1): -0.3 5<=flb / ft<0 related to the focal length flb of the rear group and the focal length ft of the entire lens system at the telephoto end is satisfied.

An imaging lens consists of, in order from the object side, a front group having a negative refractive power, a stop, and a rear group having a positive refractive power. The front group consist of a front-group negative lens group that consists of three negative lenses and has a negative refractive power, and a front-group positive lens group that includes one positive lens and one negative lens and has a positive refractive power, where the negative lens is disposed at the most image-side position. The rear group includes two positive lenses and two negative lenses. The imaging lens satisfies condition expression (1): 0.95<−fAn / f<2, where fAn is a focal length of the front-group negative lens group, and f is a focal length of the entire system.