Patents by Inventor Keitaro Yokoyama
Keitaro Yokoyama 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: 10606045Abstract: A zoom lens comprises four lens unit, and at the time of zooming, each of a distance between a first positive lens unit and a first negative lens unit and a distance between a second negative lens unit and a second positive lens unit changes, and a distance between the first positive lens unit and the second negative lens unit widens more at the telephoto end than at the wide angle end, and the first positive lens unit includes an object-side sub-lens unit and an image-side sub-lens unit, and an aperture stop is disposed between the object-side sub-lens unit and the image-side sub-lens unit, and the first negative lens unit includes a negative lens and a positive lens, and a refracting surface nearest to an image in the first negative lens unit is concave toward the image side, and a refracting surface nearest to an object in the second positive lens unit is concave toward the object side, and a refracting surface nearest to the image in the second positive lens unit is convex toward the image side, and the zType: GrantFiled: April 4, 2018Date of Patent: March 31, 2020Assignee: OLYMPUS CORPORATIONInventors: Kazuteru Kawamura, Akiko Naito, Keitaro Yokoyama, Toshio Takahashi
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Publication number: 20180224641Abstract: A zoom lens comprises four lens unit, and at the time of zooming, each of a distance between a first positive lens unit and a first negative lens unit and a distance between a second negative lens unit and a second positive lens unit changes, and a distance between the first positive lens unit and the second negative lens unit widens more at the telephoto end than at the wide angle end, and the first positive lens unit includes an object-side sub-lens unit and an image-side sub-lens unit, and an aperture stop is disposed between the object-side sub-lens unit and the image-side sub-lens unit, and the first negative lens unit includes a negative lens and a positive lens, and a refracting surface nearest to an image in the first negative lens unit is concave toward the image side, and a refracting surface nearest to an object in the second positive lens unit is concave toward the object side, and a refracting surface nearest to the image in the second positive lens unit is convex toward the image side, and the zType: ApplicationFiled: April 4, 2018Publication date: August 9, 2018Inventors: Kazuteru Kawamura, Akiko Naito, Keitaro Yokoyama, Toshio Takahashi
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Patent number: 9977227Abstract: A zoom lens includes in order from an object side to an image side, a first lens unit having a negative refractive power, a second lens unit having a positive refractive power, and a third lens unit having a negative refractive power. At the time of zooming, distances between the lens units change, and a distance between the first lens unit and the second lens unit at a telephoto end is shorter than a distance between the first lens unit and the second lens unit at a wide angle end, and an aperture stop is disposed on an image side of an image-side surface of the first lens unit, and on an object side of an image-side surface of the second lens unit, and the zoom lens satisfies the conditional expressions.Type: GrantFiled: November 24, 2015Date of Patent: May 22, 2018Assignee: OLYMPUS CORPORATIONInventors: Kazuteru Kawamura, Akiko Naito, Keitaro Yokoyama, Toshio Takahashi
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Patent number: 9964744Abstract: A zoom lens comprises four lens unit, and at the time of zooming, each of a distance between a first positive lens unit and a first negative lens unit and a distance between a second negative lens unit and a second positive lens unit changes, and a distance between the first positive lens unit and the second negative lens unit widens more at the telephoto end than at the wide angle end, and the first positive lens unit includes an object-side sub-lens unit and an image-side sub-lens unit, and an aperture stop is disposed between the object-side sub-lens unit and the image-side sub-lens unit, and the first negative lens unit includes a negative lens and a positive lens, and a refracting surface nearest to an image in the first negative lens unit is concave toward the image side, and a refracting surface nearest to an object in the second positive lens unit is concave toward the object side, and a refracting surface nearest to the image in the second positive lens unit is convex toward the image side, and the zType: GrantFiled: September 17, 2015Date of Patent: May 8, 2018Assignee: OLYMPUS CORPORATIONInventors: Kazuteru Kawamura, Akiko Naito, Keitaro Yokoyama, Toshio Takahashi
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Patent number: 9638917Abstract: A zoom lens includes a first lens unit having a negative refractive power, a second lens unit having a positive refractive power, and a third lens unit having a negative refractive power. At the time of zooming, distances between the lens units change, and a distance between the first lens unit and the second lens unit at a telephoto end is shorter than at a wide angle end. An aperture stop is disposed on the image side of an image-side surface of the first lens unit, and on the object side of an image-side surface of the second lens unit. The second lens unit includes two sub lens units. The object-side sub lens unit in the second lens unit includes one lens component. The following conditional expressions are satisfied. 3.0<?D12/ERS<4.5 1.05<|f3/fUN21|<2.Type: GrantFiled: August 10, 2016Date of Patent: May 2, 2017Assignee: Olympus CorporationInventors: Kazuteru Kawamura, Akiko Naito, Keitaro Yokoyama, Toshio Takahashi
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Publication number: 20160349505Abstract: A zoom lens includes a first lens unit having a negative refractive power, a second lens unit having a positive refractive power, and a third lens unit having a negative refractive power. At the time of zooming, distances between the lens units change, and a distance between the first lens unit and the second lens unit at a telephoto end is shorter than at a wide angle end. An aperture stop is disposed on the image side of an image-side surface of the first lens unit, and on the object side of an image-side surface of the second lens unit. The second lens unit includes two sub lens units. The object-side sub lens unit in the second lens unit includes one lens component. The following conditional expressions are satisfied. 3.0<?D12/ERS<4.5 1.05<|f3/fUN21|<2.Type: ApplicationFiled: August 10, 2016Publication date: December 1, 2016Inventors: Kazuteru Kawamura, Akiko Naito, Keitaro Yokoyama, Toshio Takahashi
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Patent number: 9465204Abstract: A zoom lens includes a first lens unit having a negative refractive power, a second lens unit having a positive refractive power, and a third lens unit having a negative refractive power. At the time of zooming, distances between the lens units change, and a distance between the first lens unit and the second lens unit at a telephoto end is shorter than at a wide angle end. An aperture stop is disposed on the image side of an image-side surface of the first lens unit, and on the object side of an image-side surface of the second lens unit. The second lens unit includes two sub lens units. The object-side sub lens unit in the second lens unit includes one lens component. The following conditional expressions are satisfied. 3.0<?D12/ERS<4.5 1.05<|f3/fUN21|<2.Type: GrantFiled: May 29, 2014Date of Patent: October 11, 2016Assignee: Olympus CorporationInventors: Kazuteru Kawamura, Akiko Naito, Keitaro Yokoyama, Toshio Takahashi
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Publication number: 20160077318Abstract: A zoom lens includes in order from an object side to an image side, a first lens unit having a negative refractive power, a second lens unit having a positive refractive power, and a third lens unit having a negative refractive power. At the time of zooming, distances between the lens units change, and a distance between the first lens unit and the second lens unit at a telephoto end is shorter than a distance between the first lens unit and the second lens unit at a wide angle end, and an aperture stop is disposed on an image side of an image-side surface of the first lens unit, and on an object side of an image-side surface of the second lens unit, and the zoom lens satisfies the conditional expressions.Type: ApplicationFiled: November 24, 2015Publication date: March 17, 2016Inventors: Kazuteru Kawamura, Akiko Naito, Keitaro Yokoyama, Toshio Takahashi
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Patent number: 9235037Abstract: A zoom lens includes in order from an object side to an image side, a first lens unit having a negative refractive power, a second lens unit having a positive refractive power, and a third lens unit having a negative refractive power. At the time of zooming, distances between the lens units change, and a distance between the first lens unit and the second lens unit at a telephoto end is shorter than a distance between the first lens unit and the second lens unit at a wide angle end, and an aperture stop is disposed on an image side of an image-side surface of the first lens unit, and on an object side of an image-side surface of the second lens unit, and the zoom lens satisfies the conditional expressions.Type: GrantFiled: June 19, 2014Date of Patent: January 12, 2016Assignee: OLYMPUS CORPORATIONInventors: Kazuteru Kawamura, Akiko Naito, Keitaro Yokoyama, Toshio Takahashi
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Publication number: 20160004054Abstract: A zoom lens comprises four lens unit, and at the time of zooming, each of a distance between a first positive lens unit and a first negative lens unit and a distance between a second negative lens unit and a second positive lens unit changes, and a distance between the first positive lens unit and the second negative lens unit widens more at the telephoto end than at the wide angle end, and the first positive lens unit includes an object-side sub-lens unit and an image-side sub-lens unit, and an aperture stop is disposed between the object-side sub-lens unit and the image-side sub-lens unit, and the first negative lens unit includes a negative lens and a positive lens, and a refracting surface nearest to an image in the first negative lens unit is concave toward the image side, and a refracting surface nearest to an object in the second positive lens unit is concave toward the object side, and a refracting surface nearest to the image in the second positive lens unit is convex toward the image side, and the zType: ApplicationFiled: September 17, 2015Publication date: January 7, 2016Inventors: Kazuteru Kawamura, Akiko Naito, Keitaro Yokoyama, Toshio Takahashi
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Patent number: 8988783Abstract: A zoom lens comprising, in order from the object side to the image side a first lens unit having a positive refractive power, a second lens unit having a negative refractive power, a third lens unit having a positive refractive power, a fourth lens unit having a negative refractive power, and a fifth lens unit having a positive refractive power, wherein the first lens unit is located closest to the object side, the fifth lens unit is located closest to the image side, during zooming from the wide angle end to the telephoto end, the first lens unit, the second lens unit, the third lens unit, and the fourth lens unit move, the fifth lens unit is stationary, and the distances between the lens units vary, the third lens includes a positive lens, and the zoom lens satisfies the following condition (1): 72<?3p<110??(1).Type: GrantFiled: October 2, 2013Date of Patent: March 24, 2015Assignee: Olympus Imaging Corp.Inventors: Yasuji Ogata, Yasuharu Yamada, Akiyoshi Tochigi, Keitaro Yokoyama
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Publication number: 20140375870Abstract: A zoom lens includes in order from an object side to an image side, a first lens unit having a negative refractive power, a second lens unit having a positive refractive power, and a third lens unit having a negative refractive power. At the time of zooming, distances between the lens units change, and a distance between the first lens unit and the second lens unit at a telephoto end is shorter than a distance between the first lens unit and the second lens unit at a wide angle end, and an aperture stop is disposed on an image side of an image-side surface of the first lens unit, and on an object side of an image-side surface of the second lens unit, and the zoom lens satisfies the conditional expressions.Type: ApplicationFiled: June 19, 2014Publication date: December 25, 2014Inventors: Kazuteru Kawamura, Akiko Naito, Keitaro Yokoyama, Toshio Takahashi
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Publication number: 20140354858Abstract: A zoom lens includes a first lens unit having a negative refractive power, a second lens unit having a positive refractive power, and a third lens unit having a negative refractive power. At the time of zooming, distances between the lens units change, and a distance between the first lens unit and the second lens unit at a telephoto end is shorter than at a wide angle end. An aperture stop is disposed on the image side of an image-side surface of the first lens unit, and on the object side of an image-side surface of the second lens unit. The second lens unit includes two sub lens units. The object-side sub lens unit in the second lens unit includes one lens component. The following conditional expressions are satisfied. 3.0<?D12/ERS<4.5 1.05<|f3/fUN21|<2.Type: ApplicationFiled: May 29, 2014Publication date: December 4, 2014Applicants: OLYMPUS CORPORATION, OLYMPUS IMAGING CORP.Inventors: Kazuteru Kawamura, Akiko Naito, Keitaro Yokoyama, Toshio Takahashi
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Publication number: 20140139720Abstract: A zoom lens comprising, in order from the object side to the image side a first lens unit having a positive refractive power, a second lens unit having a negative refractive power, a third lens unit having a positive refractive power, a fourth lens unit having a negative refractive power, and a fifth lens unit having a positive refractive power, wherein the first lens unit is located closest to the object side, the fifth lens unit is located closest to the image side, during zooming from the wide angle end to the telephoto end, the first lens unit, the second lens unit, the third lens unit, and the fourth lens unit move, the fifth lens unit is stationary, and the distances between the lens units vary, the third lens includes a positive lens, and the zoom lens satisfies the following condition (1): 72<?3p<110??(1).Type: ApplicationFiled: October 2, 2013Publication date: May 22, 2014Applicant: Olympus Imaging Corp.Inventors: Yasuji Ogata, Yasuharu Yamada, Akiyoshi Tochigi, Keitaro Yokoyama
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Patent number: 8248716Abstract: An imaging optical system has, in order from the object side to the image side thereof, a front lens group, an aperture stop, and a rear lens group. A lens located closest to object side in said front lens group always remains fixed in position, with satisfaction of the following conditions (1) and (2): 1.15?fb/IH??1.7 ??(1) ?4.0?fn/f??1.3 ??(2) where f is a focal length of the whole imaging optical system, fn is a focal length of a first negative lens in said front lens group, fb is a back focus of the imaging optical system upon focusing on an object point at infinity, and IH? is a distance from an optical axis of a position where a chief ray from a maximum incident half angle of view (?) upon focusing on an object point at infinity is imaged at the imaging plane.Type: GrantFiled: October 21, 2010Date of Patent: August 21, 2012Assignee: Olympus Imaging Corp.Inventors: Kazuteru Kawamura, Keitaro Yokoyama
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Publication number: 20110235191Abstract: An imaging optical system has, in order from the object side to the image side thereof, a front lens group, an aperture stop, and a rear lens group. A lens located closest to object side in said front lens group always remains fixed in position, with satisfaction of the following conditions (1) and (2): 1.15?fb/IH??1.7 ??(1) ?4.0?fn/f??1.3 ??(2) where f is a focal length of the whole imaging optical system, fn is a focal length of a first negative lens in said front lens group, fb is a back focus of the imaging optical system upon focusing on an object point at infinity, and IH? is a distance from an optical axis of a position where a chief ray from a maximum incident half angle of view (?) upon focusing on an object point at infinity is imaged at the imaging plane.Type: ApplicationFiled: October 21, 2010Publication date: September 29, 2011Inventors: Kazuteru Kawamura, Keitaro Yokoyama
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Patent number: 7969658Abstract: The invention relates to an eyepiece optical system that, albeit being of small size, works in favor of gaining an angle of field and optical performance, and an electronic view finder incorporating such an eyepiece optical system. Specifically, the invention is characterized by comprising, in order from an object side to an exit side thereof, a first lens group that is a single lens that has positive refracting power and is in a meniscus configuration concave on its object side, a second lens group that is a single lens that has negative refracting power and is in a meniscus configuration concave on its object side, and a third lens group that is a single lens that has positive refracting power, wherein an object-side concave lens surface in the first lens group is an aspheric surface, an object-side concave lens surface in the second lens group is an aspheric surface, and an exit-side lens surface in the third lens group is an aspheric surface.Type: GrantFiled: May 7, 2010Date of Patent: June 28, 2011Assignee: Olympus Imaging Corp.Inventors: Akinori Nishio, Keitaro Yokoyama, Daichi Murakami
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Patent number: 7855837Abstract: The invention provides a viewing optical system comprising: a screen on which an object image by a taking lens is formed, an image erection optical system for erecting the object image formed on the screen, and an eyepiece lens system of positive refracting power for guiding a light beam leaving the image erection optical system to the eyeball of a viewer, wherein: the image erection optical system comprises a plurality of reflecting surfaces, the eyepiece optical system comprises, in order from a screen side to an exit pupil side, a first lens element of negative refracting power, a second lens element convex on both the screen side and the exit pupil side, and a third lens element that is of negative refracting power and has a meniscus shape concave on the exit pupil side, and the third lens element satisfies the following condition (1): 0.13<DL3/fe<0.Type: GrantFiled: April 7, 2009Date of Patent: December 21, 2010Assignee: Olympus Imaging Corp.Inventor: Keitaro Yokoyama
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Publication number: 20100290129Abstract: The invention relates to an eyepiece optical system that, albeit being of small size, works in favor of gaining an angle of field and optical performance, and an electronic view finder incorporating such an eyepiece optical system. Specifically, the invention is characterized by comprising, in order from an object side to an exit side thereof, a first lens group that is a single lens that has positive refracting power and is in a meniscus configuration concave on its object side, a second lens group that is a single lens that has negative refracting power and is in a meniscus configuration concave on its object side, and a third lens group that is a single lens that has positive refracting power, wherein an object-side concave lens surface in the first lens group is an aspheric surface, an object-side concave lens surface in the second lens group is an aspheric surface, and an exit-side lens surface in the third lens group is an aspheric surface.Type: ApplicationFiled: May 7, 2010Publication date: November 18, 2010Inventors: Akinori Nishio, Keitaro Yokoyama, Daichi Murakami
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Publication number: 20100027985Abstract: An in-finder display apparatus comprises: a finder optical system adapted to view an object image formed by a taking lens on a focal plane plate by means of an eyepiece lens through a penta roof prism, a display cell located on a display member disposed near an imaging plane for the object image, and an illuminating optical system for illuminating the display cell. The display cell is illuminated by the illuminating optical system so that light reflected off the display cell together with the object image is viewable via the finder optical system. The illuminating optical system comprises: a light emitting means, and a light projecting lens for converging a light beam leaving the light emitting means. The illuminating optical system is positioned such that an illuminating light beam leaving the light emitting means in the illuminating optical system enters the display cell after transmitting through the light projecting lens.Type: ApplicationFiled: July 27, 2009Publication date: February 4, 2010Inventors: Keitaro Yokoyama, Ryuji Kamada