1. A zoom lens unit, comprising:
a first lens group having a positive refracting power;
a second lens group having a negative refracting power; and
a subsequent lens group comprising one or more lens groups and having a positive refracting power as a whole, said one or more lens groups comprising a third lens group,
the first lens group, the second lens group and the subsequent lens group being arranged in this order from an object side to an image side,
an aperture stop disposed between the second lens group and the third lens group,
wherein when changing a magnification from a wide angle end to a telephoto end, a distance between the first lens group and the second lens group increases, while a distance between the second lens group and the subsequent lens group decreases,
wherein a lens construction including the first and the second lens groups satisfies the condition:
1.0<ri ri+1<5.0\u2003\u2003(1),
in which ri and ri+1 are curvature radii of lens surfaces Si and Si+1 in the lens construction, respectively, the lens surfaces Si and Si+1 being\u201ci\u201dth and \u201ci+1\u201dth lens surfaces, respectively, counted from the object side,
and wherein a reflectivity-reducing treatment adapted to reduce intensity of a ghost image is performed on each lens surface forming at least one of pairs of lens surfaces satisfying the condition (1).
2. A zoom lens unit according to claim 1, wherein the reflectivity-reducing treatment adapted to reduce intensity of the ghost image is performed on the lens surfaces forming all the pair or pairs of lens surfaces satisfying the condition (1).
3. A zoom lens unit according to claim 1, wherein the reflectivity-reducing treatment performed on the lens surfaces gives a refractivity R200 (unit: %): R200<0.7 (2) for a flux of a perpendicular incident light in a range of wavelength 450-650 nm.
4. A zoom lens unit according to claim 1,
wherein, within a range of wavelength 450-650 nm with respect to the perpendicular incident light flux, each lens surface forming at least one of the pairs of lens surfaces satisfying the condition (1) exhibits that:
in a wavelength range the reflectivity is equal to or less than 0.3%,
in a wavelength range the reflectivity is more than 0.3%, and
the reflectivity-reducing treatment on said each lens surface is performed such that the reflectivity of one or both of said lens surfaces is equal to or less than 0.3% over the range of wavelength 450-650 nm.
5. A zoom lens unit according to claim 1,
wherein the reflectivity-reducing treatment of each lens surface is performed such that:
in a desired continuous wavelength range within wavelength 450-650 nm, with respect to the perpendicular incident light flux, the reflectivity of each lens surface forming at least one of the pairs of lens surfaces satisfying the condition (1), is equal to or less than 0.3%.
6. A zoom lens unit according to claim 1, wherein the lens construction including the first and the second lens groups satisfies the condition:
2.0<riri+1<5.0\u2003\u2003(1A),
in which ri and ri+1 are curvature radii of lens surfaces Si and Si+1 in the lens construction, respectively, the lens surfaces Si and Si+1 being \u201ci\u201dth and \u201ci1\u201dth lens surfaces, respectively, counted from the object side,
and wherein the reflectivity-reducing treatment adapted to reduce intensity of the ghost image is performed on each lens surface forming at least one of the pairs of lens surfaces satisfying the condition (1A).
7. A zoom lens unit according to claim 6, wherein the reflectivity-reducing treatment adapted to reduce intensity of the ghost image is performed on the lens surfaces forming all the pair or pairs of lens surfaces satisfying the condition (1A).
8. A zoom lens unit according to claim 6, wherein the reflectivity-reducing treatment performed on the lens surfaces gives a refractivity R200 (unit: %): R200<0.7 (2) for a flux of a perpendicular incident light in a range of wavelength 450-650 nm.
9. A zoom lens unit according to claim 6,
wherein, within a range of wavelength 450-650 nm with respect to the perpendicular incident light flux, each lens surface forming at least one of the pairs of lens surfaces satisfying the condition (1A) exhibits that:
in a wavelength range the reflectivity is equal to or less than 0.3%,
in a wavelength range the reflectivity is more than 0.3%, and
the reflectivity-reducing treatment on said lens surface is performed such that the reflectivity of one or both of said lens surfaces is equal to or less than 0.3% over the range of wavelength 450-650 nm.
10. A zoom lens unit according to claim 6,
wherein the reflectivity-reducing treatment of each lens surface is performed such that:
in a desired continuous wavelength range within wavelength 450-650 nm, with respect to the perpendicular incident light flux, the reflectivity of each lens surface forming at least one of the pairs of lens surfaces satisfying the condition (1A), is equal to or less than 0.3%.
11. A zoom lens unit according to claim 1, wherein the reflectivity-reducing treatment includes:
a multilayer film being layered on the lens surface and having a function of reducing the reflectivity.
12. A zoom lens unit according to claim 1, wherein the reflectivity-reducing treatment includes:
a subwavelength structure being formed as a surface shape of the lens surface to reduce the reflectivity.
13. A zoom lens unit according to claim 1,
wherein the first lens group includes three lenses in order from the object side:
a negative lens having a large curvature surface on the image side;
a positive meniscus lens having a convex surface on the object side; and
a positive lens having a convex surface on the object side,
wherein the positive meniscus lens has the lens surface Si on the image side, the positive lens has the lens surface Si+1 on the object side, and the lens surface Si and the lens surface Si+1 satisfy the condition (1).
14. A zoom lens unit according to claim 1,
wherein a lens surface nearest to the image side of the first lens group is a concave surface, a lens surface nearest to the object side of the second lens group is a convex surface, and
wherein the condition (1) is satisfied, where the concave surface is the lens surface Si, and the convex surface is the lens surface Si+1.
15. A zoom lens unit according to claim 1,
wherein the subsequent lens group arranged on the image side of the aperture stop comprises the third lens group having a positive refracting power, and a fourth lens group having a positive refracting power, and when changing the magnification from the wide angle end to the telephoto end, the first lens group and the third lens group move to the object side.
16. A zoom lens unit according to claim 15, which satisfies the conditions:
0.30<X1fT<0.85\u2003\u2003(3),
0.15<X3fT<0.50\u2003\u2003(4),
in which X1 is a total displacement of the first lens group when changing the magnification from the wide angle end to the telephoto end, X3 is a total displacement of the third lens group when changing the magnification from the wide angle end to the telephoto end, and fT is a focal length of the entire system at the telephoto end.
17. A zoom lens unit according to claim 16, which satisfies the condition:
0.70<Y\u2032maxfw<1.00\u2003\u2003(5),
in which fw is a focal length of the entire system at the wide angle end, and Y\u2032max is a maximum image height.
18. A zoom lens unit according to claim 1, wherein a magnification ratio is not less than about 4.5 times, and a half field angle at the wide angle end is not less than 38 degrees.
19. An imaging device, comprising:
a light receiving element; and
an optical system for photographing which forms an image of a photographic object onto the light receiving element,
the optical system for photographing including a zoom lens unit comprising:
a first lens group having a positive refracting power;
a second lens group having a negative refracting power; and
a subsequent lens group having one or more lens groups and having a positive refracting power as a whole, said one or more lens groups having a third lens group, the first lens group, the second lens group and the subsequent lens group being arranged in this order from an object side to an image side, an aperture stop disposed between the second lens group and the third lens group, wherein when changing a magnification from a wide angle end to a telephoto end a distance between the first lens group and the second lens group increases, while a distance between the second lens group and the subsequent lens group decreases, wherein a lens construction including the first and the second lens groups satisfies the condition:
1.0<riri+1<5.0\u2003\u2003(1),
in which r1 and ri+1 are curvature radii of lens surfaces Si and Si+1 in the lens construction, respectively, the lens surfaces Si and Si+1 being\u201ci\u201dth and\u201ci+1\u201dth lens surfaces, respectively, counted from the object side, and wherein a reflectivity-reducing treatment adapted to reduce intensity of a ghost image is performed on each lens surface forming at least one of pairs of lens surfaces satisfying the condition (1).
20. A photographing device, including an imaging device comprising:
a light receiving element; and
an optical system for photographing which forms an image of a photographic object onto the light receiving element,
the optical system for photographing including a zoom lens unit comprising:
a first lens group having a positive refracting power;
a second lens group having a negative refracting power; and
a subsequent lens group having one or more lens groups and having a positive refracting power as a whole, said one or more lens groups having a third lens group, the first lens group, the second lens group and the subsequent lens group being arranged in this order from an object side to an image side, an aperture stop disposed between the second lens group and the third lens group, wherein when changing a magnification from a wide angle end to a telephoto end a distance between the first lens group and the second lens group increases, while a distance between the second lens group and the subsequent lens group decreases; wherein a lens construction including the first and the second lens groups satisfies the condition:
1.0<riri+1<5.0\u2003\u2003(1),
in which ri and ri+1 are curvature radii of lens surfaces Si and Si+1 in the lens construction, respectively, the lens surfaces Si and Si+1 being\u201ci\u201dth and\u201ci+1\u201dth lens surfaces, respectively, counted from the object side, and wherein a reflectivity-reducing treatment adapted to reduce intensity of a ghost image is performed on each lens surface forming at least one of pairs of lens surfaces satisfying the condition (1).
21. A photographing device according to claim 20, wherein the photographing device is structured as a camera.
22. A photographing device according to claim 20, wherein the photographing device is structured as a mobile information terminal.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. A wheel adapted to provide locomotive traction while in contact with a surface, said wheel including a hollow interior including a series of hollow segments, said hollow segments are each adapted for storing and transferring a fluid to other said segments, said storing and transferring said fluid modifies a mass moment of inertia of said wheel when said wheel is accelerating or decelerating while rotating.
2. The wheel of claim 1, wherein said storing and transferring of said fluid automatically modifies said mass moment of inertia of said wheel as a function of the angular velocity of said wheel.
3. The wheel of claim 1, wherein said storing and transferring of said fluid selectively modifies the mass moment of inertia of said wheel.
4. The wheel of claim 1, wherein said storing and transferring of said fluid tends to maintain the mass moment of inertia when said wheel is rotationally decelerating.
5. The wheel of claim 1 wherein said storing and transferring of said fluid is adapted to modify the magnitude of the wheel’s mass moment of inertia by up to at least about seven percent.
6. The wheel of claim 1, wherein said storing and transferring of said fluid is adapted to modify the magnitude of the wheel’s moment of inertia by up to at least about forty percent.
7. The wheel of claim 1 wherein said storing and transferring of said fluid is adapted to modify the magnitude of the wheel’s moment of inertia by up to at least about twenty-five percent.
8. A traction wheel having a variable mass moment of inertia, the traction wheel including:
a traction wheel including solid components and a fluid component;
said solid components including a circular shaped body having a hollow interior including a series of hollow segments adapted for storing and transferring a fluid component; and
wherein said hollow segments providing a means for altering an angular velocity of said circular shaped body of said wheel while said wheel is rotating.
9. The traction wheel of claim 8, wherein said altering means is capable of altering said angular velocity of said body relative to an alternative angular velocity of said body when said body is otherwise absent of said fluid component.
10. The traction wheel of claim 8, wherein said body rotates about an axis of rotation, and wherein said altering means includes a tube that is substantially concentric about said axis and that encloses said fluid component.
11. The traction wheel of claim 10, wherein said tube is partially filled with said fluid.
12. The traction wheel of claim 8, wherein said body rotates about an axis of rotation, and includes a floating ring disposed substantially concentric with said axis, and wherein said altering means includes a support ring disposed substantially concentric with said axis.
13. The traction wheel of claim 12, wherein said altering means further includes means for inducing said floating ring to rotate concurrently with said support rings.