Patents by Inventor Hirofumi Tabata
Hirofumi Tabata 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: 11899280Abstract: There is provided: an optical system including a focus lens group having positive refractive power and configured to move along an optical axis when focusing from an infinite-distance object to a short-distance object, and satisfying predetermined conditional expressions; and an imaging device including the optical system. The focus lens group includes a lens subgroup A, an aperture stop, and a lens subgroup B in order from the object side. The lens subgroup A includes a negative lens, a positive lens, and a positive lens in order from the image side. The lens subgroup B includes a negative lens and a positive lens in order from the object side.Type: GrantFiled: September 20, 2021Date of Patent: February 13, 2024Assignee: Tamron Co., Ltd.Inventors: Toshiya Segawa, Yuki Mori, Hirofumi Tabata
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Patent number: 11487092Abstract: A zoom lens includes, in order from an object side, a first lens group that is positive, a second lens group that is negative, a third lens group that is positive, and a fourth lens group that is positive. During zooming from a wide angle end to a telephoto end, at least the first lens group and the third lens group are fixed and an interval on an optical axis of an adjacent lens group relative thereto is changed. In the zoom lens, the fourth lens group includes at least one positive lens and satisfies a predetermined conditional expression. In addition, an imaging device includes the zoom lens and an image sensor.Type: GrantFiled: August 13, 2020Date of Patent: November 1, 2022Assignee: TAMRON CO., LTD.Inventors: Hirofumi Tabata, Takahiro Mitsuhashi, Toshiya Segawa
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Publication number: 20220171160Abstract: There is provided: an optical system including a focus lens group having positive refractive power and configured to move along an optical axis when focusing from an infinite-distance object to a short-distance object, and satisfying predetermined conditional expressions; and an imaging device including the optical system. The focus lens group includes a lens subgroup A, an aperture stop, and a lens subgroup B in order from the object side. The lens subgroup A includes a negative lens, a positive lens, and a positive lens in order from the image side. The lens subgroup B includes a negative lens and a positive lens in order from the object side.Type: ApplicationFiled: September 20, 2021Publication date: June 2, 2022Applicant: TAMRON CO., LTD.Inventors: Toshiya SEGAWA, Yuki MORI, Hirofumi TABATA
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Publication number: 20220171159Abstract: There is provided: an optical system including a focus lens group having positive refractive power and configured to move along an optical axis when focusing from an infinite-distance object to a short-distance object, and satisfying predetermined conditional expressions; and an imaging device including the optical system. The focus lens group includes a lens subgroup A, an aperture stop, and a lens subgroup B in order from the object side. The lens subgroup A includes a negative lens, a positive lens, and a positive lens in order from the image side. The lens subgroup B includes a negative lens and a positive lens in order from the object side.Type: ApplicationFiled: September 20, 2021Publication date: June 2, 2022Applicant: TAMRON CO., LTD.Inventors: Toshiya SEGAWA, Yuki MORI, Hirofumi TABATA
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Publication number: 20220163766Abstract: There are provided an optical system and an imaging device including the same. The optical system includes: in order from an object side to an image side, a first lens group having refractive power; and a second lens group having positive refractive power. A variable distance that varies during focusing between the first lens group and the second lens group is closer to an object than a variable distance that varies during focusing between other lenses. The first lens group includes a positive lens and at least one or more negative lenses in order from the image side. The second lens group includes a lens subgroup 2A having positive refractive power, an aperture stop, and a lens subgroup 2B having positive refractive power in order from the object side. The lens subgroup 2B includes a negative lens and a positive lens in order from the object side and satisfies a predetermined Conditional Expression.Type: ApplicationFiled: September 20, 2021Publication date: May 26, 2022Applicant: TAMRON CO., LTD.Inventors: Toshiya SEGAWA, Yuki MORI, Hirofumi TABATA
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Publication number: 20210199939Abstract: A zoom lens includes, in order from an object side, a first lens group that is positive, a second lens group that is negative, a third lens group that is positive, and a fourth lens group that is positive. During zooming from a wide angle end to a telephoto end, at least the first lens group and the third lens group are fixed and an interval on an optical axis of an adjacent lens group relative thereto is changed. In the zoom lens, the fourth lens group includes at least one positive lens and satisfies a predetermined conditional expression. In addition, an imaging device includes the zoom lens and an image sensor.Type: ApplicationFiled: August 13, 2020Publication date: July 1, 2021Inventors: Hirofumi TABATA, Takahiro MITSUHASHI, Toshiya SEGAWA
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Publication number: 20160187629Abstract: A zoom lens includes sequentially from an object side, a first lens group having a negative refractive power; a second lens group having a positive refractive power; and a third lens group. The zoom lens performs zooming by varying intervals of the first, the second, and the third lens groups, on an optical axis. The second lens group is configured to include sequentially from the object side, a positive lens, a negative lens, and a positive lens. The third lens group is configured to include a negative lens farthest on the object side. The zoom lens satisfies a condition expression (1) 2.8?|?2T/?2W|?12.0, where ?2T represents magnification of the second lens group at a telephoto edge, and ?2W represents magnification of the second lens group at a wide angle edge.Type: ApplicationFiled: August 20, 2015Publication date: June 30, 2016Applicant: TAMRON CO., LTD.Inventor: Hirofumi TABATA
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Patent number: 5272004Abstract: Pitch-based carbon fiber having from 2 to 200 twists per 1 cm length or from 2 to 200 twists per 1 cm length and curls are provided. These fibers show superior properties as carbon fibers useful for non-woven fabrics or for fabrics.Type: GrantFiled: November 6, 1992Date of Patent: December 21, 1993Assignee: Petoca Ltd.Inventors: Hirofumi Tabata, Akio Takamatsu