Abstract: The invention provides a zoom lens system suitable for an image gathering system using a solid-state imaging device, having a zoom ratio of about three, a small lens length, and superb optical performance. The zoom lens system includes, in order from an object, a first lens group having negative refractive power, a second lens group having positive refractive power, and a third lens group having positive refractive power. The first lens group consists only of a negative lens and a positive lens. The second lens group includes at least two positive lenses and at least one negative lens. The third lens group consists of one lens. Zooming from a wide-angle end state to a telephoto end state is conducted by decreasing a distance between the first and second lens groups, increasing a distance between the second and third lens groups, and fixing the third lens group. Given conditions are satisfied.

Abstract: The present invention provides a zoom lens system suitable for an image gathering system using a solid-state imaging device, having a zoom ratio of about three, a small total lens length, and superb optical performance. According to one aspect, in order from the object side, a first lens group having negative refractive power, a second lens group having positive refractive power, and a third lens group having positive refractive power. Zooming is carried out by varying distances between adjacent lens groups. The first lens group includes two negative lens elements and a positive lens element. The second lens group includes three lens elements consisting of a first positive lens element, a second positive lens element, and a negative lens element. The third lens group includes at least one positive lens element. Predetermined conditional expressions are satisfied.

Abstract: The invention provides a fisheye lens system having an angle of view of 170 degrees or more capable of being used with a plurality of cameras having different image formats in size. The lens system includes a first lens group G1 having negative refractive power disposed to the most object side and a second lens group G2 having positive refractive power disposed to an image side of the first lens group. A distance between the first lens group G1 and the second lens group G2 is variable. The lens system takes the maximum focal length state when the distance is minimum and the minimum focal length state when the distance is maximum. The maximum image height in the maximum focal length state is different from that in the minimum focal length state. In each focal length state, the fisheye lens system has an angle of view of 170 degrees or more.

Abstract: A zoom lens system includes, in order from an object, a first lens group G1 having positive refractive power, a second lens group G2 having negative refractive power, a third lens group G3. having positive refractive power, a fourth lens group G4 having positive refractive power, and a fifth lens group G5 having positive refractive power. Upon zooming from a wide-angle end state to a telephoto end state, a separation between the first lens group G1 and the second lens group G2 increases, a separation between the second lens group G2 and the third lens group G3 decreases, a separation between the third lens group G3 and the fourth lens group G4 varies, a separation between the fourth lens group G4 and the fifth lens group G5 increases, and the third lens group G3 and the fourth lens group G4 moving to the object side. Predetermined conditional expressions are satisfied.

Abstract: A zoom lens system includes, in order from an object, a first lens group G1 having positive refractive power, a second lens group G2 having negative refractive power, a third lens group G3 having positive refractive power, a fourth lens group G4 having positive refractive power, and a fifth lens group G5 having positive refractive power. Upon zooming from a wide-angle end state to a telephoto end state, a separation between the first lens group G1 and the second lens group G2 increases, a separation between the second lens group G2 and the third lens group G3 decreases, a separation between the third lens group G3 and the fourth lens group G4 varies, a separation between the fourth lens group G4 and the fifth lens group G5 increases, and the third lens group G3 and the fourth lens group G4 moving to the object side. Predetermined conditional expressions are satisfied.

Abstract: The present invention provides a zoom lens system suitable for an image gathering system using a solid-state imaging device, having a zoom ratio of about three, a small total lens length, and superb optical performance. According to one aspect, in order from the object side, a first lens group having negative refractive power, a second lens group having positive refractive power, and a third lens group having positive refractive power. Zooming is carried out by varying distances between adjacent lens groups. The first lens group includes two negative lens elements and a positive lens element. The second lens group includes three lens elements consisting of a first positive lens element, a second positive lens element, and a negative lens element. The third lens group includes at least one positive lens element. Predetermined conditional expressions are satisfied.

Abstract: The object of the present invention is to provide a wide converter lens capable of obtaining an angle of view of about 80° or over and having small appearance of distortion. According to one aspect, a wide converter lens for using by attaching to an object side of a photographic lens includes, in order from the object side, a first positive lens having double convex surfaces, a negative lens unit including at least one negative lens, and a second positive lens having double convex surfaces. The following conditional expression is satisfied: −0.8<(r2+r1)/(r2−r1)<0.8 where r1 denotes the radius of curvature of the object side surface of the first positive lens and r2 denotes the radius of curvature of the image side surface of the first positive lens.

Abstract: The present invention provides a compact zoom lens system suitable for a video camera and a digital still camera using a solid-state imaging device, having a zoom ratio of 3.5 or more, an angle of view in a wide-angle end state of about 60°, and superb optical performance. According to one aspect, in order from an object side, a first lens group has negative refractive power, a second lens group has positive refractive power, and a third lens group has positive refractive power. The front principal point of the second lens group is located to the object side of the most object side surface of the second lens group. The distance between the first and second lens group is decreased and the distance between the second and third lens group is increased upon zooming from a wide-angle end state to a telephoto end state. Predetermined conditional expressions are satisfied.

Abstract: A grease composition for rolling bearing comprising a metal soap-based thickening agent containing a long fiber-like material having a major axis length of at least 3 &mgr;m incorporated in a base oil comprising a lubricant having a polar group in its molecular structure and a non-polar lubricant blended in combination.

Abstract: The present invention provides a compact zoom lens system suitable for a video camera and a digital still camera using a solid-state imaging device, having a zoom ratio of 3.5 or more, an angle of view in a wide-angle end state of about 60°, and superb optical performance. According to one aspect, in order from an object side, a first lens group has negative refractive power, a second lens group has positive refractive power, and a third lens group has positive refractive power. The front principal point of the second lens group is located to the object side of the most object side surface of the second lens group. The distance between the first and second lens group is decreased and the distance between the second and third lens group is increased upon zooming from a wide-angle end state to a telephoto end state. Predetermined conditional expressions are satisfied.

Abstract: The present invention relates to pyridone derivatives and herbicidal compositions containing the pyridone derivatives as active ingredients.

Abstract: A grease composition for rolling bearing comprising a metal soap-based thickening agent containing a long fiber-like material having a major axis length of at least 3 &mgr;m incorporated in a base oil comprising a lubricant having a polar group in its molecular structure and a non-polar lubricant blended in combination.

Abstract: A variable focal length lens system with low cost, suitable for use with a video camera or a digital still camera employing a solid-state imaging device, capable of assembling and adjusting with ease, and to provide an imaging apparatus equipped with the lens system is provided.

Abstract: The object of the present invention is to provide a wide converter lens capable of obtaining an angle of view of about 80° or over and having small appearance of distortion. According to one aspect, a wide converter lens for using by attaching to an object side of a photographic lens includes, in order from the object side, a first positive lens having double convex surfaces, a negative lens unit including at least one negative lens, and a second positive lens having double convex surfaces.

Abstract: The present invention makes it possible to provide a variable focal length lens system having a zoom ratio of 2.5 or over, a field angle of 60° or over at the wide-angle end, and an excellent imaging quality which is suited for use with a video camera and the like. According to one aspect of the present invention, a variable focal length lens system has, in order from an object side, a first negative lens group G1, a second positive lens group G2, and a third positive lens group G3.

Abstract: The present invention relates to pyridone derivatives and herbicidal compositions containing the pyridone derivatives as active ingredients.

Abstract: The present invention provides a grease composition excellent in both rust-proofing properties and safety. The grease composition comprises a lubricating base oil and a thickener, and further comprises a lipophilic organic inhibitor, a nonionic surface active agent and a hydrophilic organic inhibitor selected from the group consisting of lanolin fatty acid derivative and alkanolamine derivative modified with a hydrophilic group each in an amount of from 0.1 to 10% by weight based on the total weight of said grease composition.

Abstract: A lubricating grease composition comprises a base oil and a thickening agent, wherein the thickening agent comprises (a) a lithium salt of hydroxystearic acid and (b) a lithium salt of a C6 to C14 fatty acid. The grease composition is useful for the improvement of the acoustic characteristics of bearings, in particular, the reduction of noise and the elongation of the service life of the bearings. Accordingly, the grease composition can be used for lubricating bearings, in particular, those used in spindle motors for the operation of recording devices such as those for computer hard disks and CD-ROM's.

Abstract: A variable magnification zoom lens system comprising: in order from the object side, a first lens group having a negative refractive power and a focal length f1; a second lens group having a positive refractive power; and a third lens group having a positive refractive power and a focal length f3 with the first and second lens group arranged to be driven together such that when zooming is performed from the maximum wide-angle state to the maximum telephoto state of the zoom lens system, the first lens group and the second lens group move such that the distance between the first lens group and the second lens group is decreased, and at the same time, the distance between second lens group and the third lens group is increased and with the following condition being fulfilled: 0.4<f3/.vertline.f1.vertline.<0.8.

Abstract: A pyridone derivative represented by the general formula: ##STR1## {wherein R is an alkyl group or a haloalkyl group, R.sup.1 is a hydrogen atom, an alkyl group, a haloalkyl group, an acetyl group, an amino group, an alkoxycarbonylamino group, an alkylcarbonylamino group or the like, R.sup.2 is a hydrogen atom, an alkyl group, a carboxyl group or an alkoxycarbonyl group, R.sup.19 is a hydrogen atom, a halogen atom, a cyano group or the like, Q is a phenyl group which may be substituted or a condensed hetero ring which may be substituted}, a herbicide containing it and an intermediate for its production, are provided.