38results about How to "Small F value" patented technology

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.

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 an imaging lens that well corrects various aberrations and has a high resolution while meeting the requirements of wide angle, low back, and low F value in a well-balanced manner. The imaging lens includes: a first lens having a convex surface facing an object side in the vicinity of an optical axis and having a negative focal power; a second lens having a negative focal power; a third lens; a fourth lens having a biconvex shape in the vicinity of the optical axis; and a fifth lens being disposed in such a manner that the lenses are not joined from the first lens to thefifth lens, and satisfying the conditional expression (1). (1) 0.50<r5 / r6<12.50 wherein r5: the radius of curvature of the surface on an object side of the third lens, and r6: the radius of curvatureof the surface on an image side of the third lens.

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.

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 1.58<Ndi where Ndi is the refractive index of the i-th positive lens at the d-ray.

A compact imaging lens suitable for a high pixel density image pickup device which properly corrects chromatic aberration and other types of aberrations and ensures high image quality, low f-number, and low cost. A first lens, second lens, third lens, fourth lens, and fifth lens are arranged in order from the object side and both sides of all the lenses are aspheric surfaces and a diffractive optical surface with a chromatic aberration correction function is formed on one of the surfaces from the object side surface of the first lens to the object side surface of the second lens and on one of the surfaces from the object side surface of the third lens to the object side surface of the fifth lens. All the lenses are made of a plastic material.

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.

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.

A compact, wide view-field imaging lens with a small F-value which corrects aberrations properly. Its elements are arranged in order from an object side to an image side: an aperture stop, positive first lens having convex surfaces on the object and image sides, negative second lens having a concave object-side surface near an optical axis, positive meniscus third lens having a convex image-side surface, and negative meniscus double-sided aspheric fourth lens having a concave image-side surface near the optical axis. Its F-value is smaller than 2.4 and it satisfies conditional expressions (1) to (3) below:0.15<f12 / f34<0.5   (1)0.1<|r1 / r2|<0.5   (2)1.0<f1 / f3<1.6   (3)wheref1: first lens focal lengthf3: third lens focal lengthf12: composite focal length of the first and second lensesf34: composite focal length of the third and fourth lensesr1: curvature radius of the first lens object-side surfacer2: curvature radius of the first lens image-side surface.

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 imaging lens comprising, in order from the object side: an aperture stop; a positive 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 of the lenses are made of a plastic material.

An imaging lens includes four lenses arranged in order from the object side to the image side: an aperture stop, positive (refractive power) first lens having a convex object-side surface near the optical axis, second lens having a positive meniscus shape near the axis, positive third lens having a convex image-side surface near the axis, and negative fourth lens having a concave image-side surface near the axis. All lens surfaces are aspheric. The image-side aspheric surface of the fourth lens has a pole-change point off the optical axis and conditional expressions (1) and (2) are satisfied:0.75<TLA / (2IH)<0.90  (1)0.90<TLA / f<1.30  (2)whereTLA: distance on the optical axis from the first lens's object-side surface to the image sensor's image plane without a filter between the fourth lens and image sensorIH: maximum image heightf: overall optical system focal length.

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 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.

An imaging lens includes, consecutively in order from the most object-side, a positive first lens group, a positive second lens group and a third lens group. 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 and the third lens group in such a manner that a distance between the second lens group and the third lens group changes while the first lens group is fixed. The first lens group includes, consecutively in order from the most object-side, a negative first lens and a negative second lens.

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.

The present invention provides a zoom lens having a small F value in the entire zoom region and well correcting various aberrations, and an imaging device including the zoom lens. The zoom lens consists of 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 The fifth lens group (G5) configuration, when zooming from the wide-angle end to the telephoto end, the distance between the first and second lens groups is always widened, and the distance between the second and third lens groups Always narrow, the interval between the third and fourth lens groups is always changing, the interval between the fourth and fifth lens groups is always widening, the first lens group from the object side in turn from the negative, positive, positive three The second lens group is composed of negative, negative, positive and negative lenses in sequence from the object side. The third lens group is composed of four positive lenses, two negative lenses and an aperture stop. The fifth lens A group consists of a lens component.

The present invention provides an imaging lens having a small F value, a wide angle, and a compact configuration capable of obtaining good images from the center of the imaging area to the periphery of the imaging area, and an imaging device including the imaging lens. The imaging lens (1) consists of a negative first lens (L1) with a concave surface facing the image side, a positive second lens (L2) with a convex surface facing the image side, and a negative third lens with a concave surface facing the image side in order from the object side. A lens (L3), a biconvex positive fourth lens (L4), a biconvex positive fifth lens (L5), and a negative sixth lens (L6) with a concave surface facing the object side. The imaging lens (1) satisfies the conditional expression (1) related to the radius of curvature (R3) of the object-side surface of the second lens (L2) and the focal length (f) of the entire system: R3 / f<0.

PROBLEM TO BE SOLVED: To provide an inexpensive variable power optical system having a compact size and a small F value and having high optical performance with favorably corrected chromatic aberration.SOLUTION: This variable power optical system comprises, in order from an object side, a positive first lens group G1 that is fixed when varying power, a second lens group G2 varying the power by moving along an optical axis Z, an aperture that is fixed when varying the power, a positive third lens group G3 that is fixed when varying the power, and a positive fourth lens group G4 that corrects and focuses an image plane position when varying the power. The second lens group G2 is disposed with, in order from the object side, a negative lens, a positive meniscus lens having a concave surface facing the object side, a biconcave lens, and a positive lens. The variable power optical system is configured to satisfy a prescribed conditional expression related to a focal length of the second lens group G2, the Abbe number of the positive meniscus lens of the second lens group G2, and a moving distance of the second lens group G2 when varying the power from the wide end to the tele end.

The present invention provides a zoom lens with a long focal point, small size, small F value, and good optical performance, and an optical device including the zoom lens. The zoom lens has a first lens group (G1) arranged on the most magnification side and fixed when changing magnification, and a positive optical lens group (G1) arranged adjacent to the reduction side of the first lens group (G1) and moving when changing magnification. focal power of the second lens group (G2). The first lens group (G1) is substantially composed of a front group (G1A) having positive refractive power and a rear group (G1B) having negative refractive power in order from the magnification side. Focusing is performed by changing the interval between the front group (G1A) and the rear group (G1B). The zoom lens satisfies the conditional expression (1) related to the focal length (f1b) of the rear group (G1B) and the focal length (ft) of the entire system at the telephoto end: -0.35≤f1b / ft<0.

The present invention provides an imaging lens having a small F value, a wide angle, and a compact configuration capable of obtaining good images from the center of the imaging area to the periphery of the imaging area, and an imaging device including the imaging lens. The imaging lens (1) consists of a negative first lens (L1) with a concave surface facing the image side, a positive second lens (L2) with a convex surface facing the image side, and a negative third lens with a concave surface facing the image side in order from the object side. A lens (L3), a biconvex positive fourth lens (L4), a biconvex positive fifth lens (L5), and a negative sixth lens (L6) with a concave surface facing the object side. The imaging lens (1) satisfies the conditional expression (1) related to the combined focal length (f12) of the first lens (L1) and the second lens (L2) and the focal length (f) of the entire system: -5<f12 / f<- 2.