Patents by Inventor Taro Asami
Taro Asami has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).
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Patent number: 8130456Abstract: An imaging lens is provided and includes: in order from an object side thereof, a first lens of a negative lens having a concave surface on an image side thereof and having at least one aspheric surface; a second lens of a positive lens having at least one aspheric surface; a stop; and a third lens of a positive lens having a convex surface on the image side thereof and at least one aspheric surface. The following Conditional Expressions (1) and (2) are satisfied. 1.5<vd3/vd2??(1) 0.0<|f1/f23|<0.5??(2) In which vd2 represents an Abbe number of the second lens at the d-line, vd3 represents an Abbe number of the third lens at the d-line, f1 represent a focal length of the first lens, and f23 represents a composite focal length of the second and third lenses.Type: GrantFiled: March 5, 2010Date of Patent: March 6, 2012Assignee: FUJIFILM CorporationInventor: Taro Asami
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Patent number: 8054562Abstract: Disclosed is an imaging lens having a small F number, a wide angle of view, and a low manufacturing cost and capable of obtaining a high-quality image. An imaging lens includes a first lens having a negative power and including a concave surface facing an image side, a second lens having a positive power, an aperture diaphragm, a third lens having a negative power, an aperture diaphragm, a fourth lens having a positive power, a fifth lens having a positive power and including a convex surface facing the image side, and a sixth lens having a negative power arranged in this order from an object side. When the curvature radius of an image-side surface of the third lens is R3r and the curvature radius of an object-side surface of the fourth lens is R4f, the imaging lens satisfies the following Conditional expression: |R3r/R4f|<1.0.Type: GrantFiled: August 20, 2009Date of Patent: November 8, 2011Assignee: Fujinon CorporationInventor: Taro Asami
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Publication number: 20110249349Abstract: Disclosed is an image pickup lens having the following disposed from an object side in the order listed below: a first lens having a negative power and a meniscus shape with a concave surface on an image side; a second lens having a positive power; a third lens having a negative power; a fourth lens having a positive power; a fifth lens having a positive power; and a sixth lens having a negative power and a meniscus shape with a concave surface on the object side. The image pickup lens satisfies Conditional Expression (1) given below when a focal length of the first lens is taken as f1 and a focal length of the second lens is taken as f2. ?3.0<f1/f2<?1.Type: ApplicationFiled: April 11, 2011Publication date: October 13, 2011Applicant: FUJIFILM CorporationInventor: Taro ASAMI
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Patent number: 7982976Abstract: An imaging lens is provided and includes: in order from an object side of the imaging lens, a first lens group having a positive power as a whole; a second lens group including a lens in the most object side thereof, the lens having a concave surface on the object side thereof; a third lens group including a cemented lens of a lens having a positive power and a lens having a negative power; and a fourth lens group having a negative power as a whole.Type: GrantFiled: March 21, 2008Date of Patent: July 19, 2011Assignee: Fujinon CorporationInventor: Taro Asami
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Patent number: 7957074Abstract: An imaging lens system is provided an includes: in order from the object side, a first lens which has a negative power; a second lens which has a negative power; a third lens; a fourth lens which has a positive power; a fifth lens; and a sixth lens which has a positive power. The first lens is made of glass, and the second to sixth lenses are made of plastic. At least one lens surface of each of the second to sixth lenses is aspheric, and each of the third lens and the fifth lens is made of a material having an Abbe number of 45 or less at the d-line.Type: GrantFiled: May 26, 2009Date of Patent: June 7, 2011Assignee: Fujinon CorporationInventor: Taro Asami
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Publication number: 20110122512Abstract: An imaging lens includes negative first lens, negative second lens having a concave surface facing the image side, positive third lens, aperture stop, positive fourth lens, and fifth lens having a concave surface facing the object side, which are arranged sequentially from the object side. At least one of second lens, fourth lens and fifth lens has at least an aspheric surface. The Abbe number of third lens and the Abbe number of fifth lens are less than or equal to 30, and the Abbe number of fourth lens is greater than or equal to 40. Further, the following formula (1) is satisfied: 1.0<(R3?R4)/(R3+R4) ??(1), where R3: the paraxial curvature radius of an object-side surface of second lens, and R4: the paraxial curvature radius of an image-side surface of second lens.Type: ApplicationFiled: November 18, 2010Publication date: May 26, 2011Applicant: FUJIFILM CORPORATIONInventor: Taro ASAMI
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Patent number: 7911712Abstract: An imaging lens includes, in order from an object side, a first lens having a negative power and including a concave image-side surface, a second lens having a positive power, a stop, a third negative lens, which is a biconcave lens, a fourth lens having a positive power, and a fifth lens having a positive power and including a convex image-side surface. The imaging lens satisfies the following conditional expressions: 0.18<(D4+D5)/f<0.44, and 0.18<D1/f where f denotes a focal length of an entire lens system, D1 denotes a thickness of a center of the first lens, D4 denotes a distance from an image-side surface of the second lens to the stop on an optical axis, and D5 denotes a distance from the stop to an object-side surface of the third lens on the optical axis.Type: GrantFiled: October 28, 2009Date of Patent: March 22, 2011Assignee: Fujinon CorporationInventors: Yu Kitahara, Yoko Yamamoto, Taro Asami
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Patent number: 7889442Abstract: An imaging lens is provided and includes: a stop; and a lens group disposed between the stop and an imaging plane of the imaging lens and having a positive power as a whole. The lens group has an air lens formed by an air gap between lenses adjacent to each other, and the imaging lens satisfies conditional expression (1): ?8<L×(1/Ra2?1/Ra1)<?3 ??(1) Ra1 represents a radius of curvature of an object-side surface of the air lens which has a convex shape and is closest to an image side of the imaging lens in the lens group, Ra2 represents a radius of curvature of an image-side surface of the air lens, and L represents a distance on an optical axis of the imaging tens from an object-side surface of a lens closest to an object side in the imaging lens to an imaging plane.Type: GrantFiled: August 29, 2008Date of Patent: February 15, 2011Assignee: Fujinon CorporationInventors: Takashi Suzuki, Taro Asami
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Publication number: 20110026138Abstract: Disclosed is an imaging lens that has a wide angle of view, a small size in the diametric direction of a lens system, and a good optical performance. An imaging lens includes a first negative lens having a meniscus shape in which a concave surface faces an image side, a second negative lens having a meniscus shape in which a concave surface faces the image side and including at least one aspheric surface, a third positive lens including at least one aspheric surface, an aperture diaphragm, and a fourth positive lens including at least one aspheric surface, which are arranged in this order from an object side. The imaging lens satisfies the following Conditional expression 1: f2/f<?4.5??[Conditional expression 1] (where f indicates the focal length of the entire system and f2 indicates the focal length of the second lens).Type: ApplicationFiled: July 28, 2010Publication date: February 3, 2011Inventor: Taro ASAMI
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Patent number: 7843652Abstract: A wide-angle imaging lens is provided and includes: a first lens, a second lens, and a third lens in this order from the object side. The first lens is a negative meniscus and has a convex surface on the object side; the second lens, at least one surface of which is an aspherical surface; and the third lens is a positive lens and has a convex surface on the image side and at least one surface of the third lens is an aspherical surface. The first len is made of a material having an Abbe number of 40 or more and the third lens is made of a material having an Abbe number of 50 or more. An aperture stop is disposed between the second lens and the third lens.Type: GrantFiled: October 19, 2006Date of Patent: November 30, 2010Assignee: Fujinon CorporationInventors: Taro Asami, Ryoko Otomo
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Patent number: 7830620Abstract: An imaging lens includes a first lens having a negative power and including a concave surface facing an image side, a second lens having a positive power, a third lens having a positive power, an aperture diaphragm, a fourth lens, which is a biconvex lens having a negative power, a fifth lens having a positive power and including a convex surface facing the image side, and a sixth lens having a positive power and including a convex surface facing an object side, which are arranged in this order from the object side. The Abbe number of a material forming the fourth lens with respect to the d-line is 30 or less. When the focal length of the entire lens system is f and a composite focal length from the fourth lens to the sixth lens is f456, the imaging lens satisfies following conditional expression: 1.00<f456/f<1.88.Type: GrantFiled: September 17, 2009Date of Patent: November 9, 2010Assignee: Fujinon CorporationInventor: Taro Asami
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Publication number: 20100259835Abstract: An imaging lens is provided and includes: in order from the object side, a negative first lens, a negative second lens, a positive third lens, a stop, and a positive fourth lens. In the lens, each of the second lens, the third lens, and the fourth lens has at least one aspheric surface, and an Abbe number of a material of the third lens at the d-line is 35 or less. In addition, the imaging lens satisfies the following Conditional Expression (1): ?0.2<(R3+R4)/(R3?R4)<0.2??(1) where R3 is a paraxial radius of curvature of the object side surface of the second lens, and R4 is a paraxial radius of curvature of the image side surface of the second lens.Type: ApplicationFiled: April 9, 2010Publication date: October 14, 2010Inventor: Taro ASAMI
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Patent number: 7813056Abstract: An imaging lens comprises, in order from an object side: a first lens having a negative refractive power with a concave surface on an image side thereof; a second lens with at least one aspherical surface; an aperture stop; and a third lens having a positive refractive power with at least one aspherical surface, wherein the first lens is formed of an optical glass whose Abbe number is 40 or more, the second lens is formed of a plastic whose Abbe number is 40 or less, and the third lens is formed of a plastic whose Abbe number is 50 or more, and wherein assuming that a point, where a light ray which constitutes an outermost light ray in light rays which enter an image plane intersects a lens surface, constitutes an effective aperture terminating edge, the second lens is such that an intersection point between an object side surface and an optical axis lies closer to an image forming side of the imaging lens than an effective aperture terminating edge of the object side surface does.Type: GrantFiled: September 18, 2007Date of Patent: October 12, 2010Assignee: Fujinon CorporationInventor: Taro Asami
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Publication number: 20100246029Abstract: An imaging lens is provided and includes: in order from the object side, a first lens having a concave surface on an image side thereof; a second lens of a negative lens having a concave surface on the image side and having at least one aspheric surface; a third lens having at least one aspheric surface; and a fourth lens of a positive lens having a convex surface on the image side and having at least one aspheric surface. A stop is disposed between the third lens and the fourth lens. In addition, assuming that a focal length of the whole system is f and a focal length of the first lens L1 is f1, the following Conditional Expression (1) is satisfied. 15.Type: ApplicationFiled: March 30, 2010Publication date: September 30, 2010Inventor: Taro ASAMI
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Publication number: 20100226020Abstract: An imaging lens is provided and includes: in order from an object side thereof, a first lens of a negative lens having a concave surface on an image side thereof and having at least one aspheric surface; a second lens of a positive lens having at least one aspheric surface; a stop; and a third lens of a positive lens having a convex surface on the image side thereof and at least one aspheric surface. The following Conditional Expressions (1) and (2) are satisfied. 1.5<vd3/vd2??(1) 0.0<|f1/f23|<0.5??(2) In which vd2 represents an Abbe number of the second lens at the d-line, vd3 represents an Abbe number of the third lens at the d-line, f1 represent a focal length of the first lens, and f23 represents a composite focal length of the second and third lenses.Type: ApplicationFiled: March 5, 2010Publication date: September 9, 2010Inventor: Taro ASAMI
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Patent number: 7787196Abstract: An imaging lens is provided and includes: in order from an object side of the imaging lens, a first lens group having a positive power as a whole; a second lens group, in which an object-side surface of a lens closest to the object side is concave toward the object side; a third lens group of a single lens having a positive power; and a fourth lens group having a negative power as a whole.Type: GrantFiled: August 29, 2008Date of Patent: August 31, 2010Assignee: Fujinon CorporationInventors: Taro Asami, Takashi Suzuki
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Patent number: 7746572Abstract: An 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 ?2, 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: ?2>30??(1), 2.5<L/f<4.0??(2), and 0.5<Bf/f<1.3??(3).Type: GrantFiled: August 20, 2008Date of Patent: June 29, 2010Assignee: Fujinon CorporationInventor: Taro Asami
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Publication number: 20100142062Abstract: An imaging lens is provided and includes, in order from the object side, a front group having a negative power, a stop, and a rear group having a positive power. The front group includes, in order from the object side, a first negative lens having a meniscus shape with a concave surface on an image side, a second negative lens, and a third positive lens. The rear group includes, in order from the object side, a fourth positive lens, a fifth negative lens having a meniscus shape with a concave surface on the object side, and a sixth positive lens. An Abbe number of each of the first lens, the second lens, the fourth lens, and the sixth lens at the d-line is equal to or larger than 40, and an Abbe number of each of the third lens and the fifth lens at the d-line is equal to or smaller than 40. Each lens constituting the front group and the rear group is a single lens.Type: ApplicationFiled: December 10, 2009Publication date: June 10, 2010Inventors: Taro ASAMI, Ryoko Otomo
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Publication number: 20100103537Abstract: An imaging lens includes, in order from an object side, a first lens having a negative power and including a concave image-side surface, a second lens having a positive power, a stop, a third negative lens, which is a biconcave lens, a fourth lens having a positive power, and a fifth lens having a positive power and including a convex image-side surface. The imaging lens satisfies the following conditional expressions: 0.18<(D4+D5)/f<0.44, and 0.18<D1/f where f denotes a focal length of an entire lens system, D1 denotes a thickness of a center of the first lens, D4 denotes a distance from an image-side surface of the second lens to the stop on an optical axis, and D5 denotes a distance from the stop to an object-side surface of the third lens on the optical axis.Type: ApplicationFiled: October 28, 2009Publication date: April 29, 2010Inventors: Yu KITAHARA, Yoko Yamamoto, Taro Asami
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Publication number: 20100085651Abstract: An imaging lens includes a first lens having a negative power and including a concave surface facing an image side, a second lens having a positive power, a third lens having a positive power, an aperture diaphragm, a fourth lens, which is a biconvex lens having a negative power, a fifth lens having a positive power and including a convex surface facing the image side, and a sixth lens having a positive power and including a convex surface facing an object side, which are arranged in this order from the object side. The Abbe number of a material forming the fourth lens with respect to the d-line is 30 or less. When the focal length of the entire lens system is f and a composite focal length from the fourth lens to the sixth lens is f456, the imaging lens satisfies following conditional expression: 1.00<f456/f<1.88.Type: ApplicationFiled: September 17, 2009Publication date: April 8, 2010Inventor: Taro ASAMI