Patents by Inventor Keiko Sasaki
Keiko Sasaki 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: 7990608Abstract: An optical amplifier reducing gain deviation caused by wavelength arrangement has a first-stage optical amplifying unit, an attenuator, a second-stage optical amplifying unit, an automatic gain controller controlling the first- and second-stage optical amplifying units so that a gain of signal light outputted from the second-stage optical amplifying unit to signal light inputted to the first-stage optical amplifying unit is constant, and an attenuation amount controller controlling an attenuation amount at the attenuator to adjust gain-versus-wavelength characteristic at the automatic-gain-controlled first- and second-stage optical amplifying units on the basis of information on wavelength arrangement and an input level of the signal light inputted to the first-stage optical amplifying unit so that gain slope characteristic at the first- and second-stage optical amplifying units due to the wavelength arrangement and the input level is flattened.Type: GrantFiled: August 27, 2007Date of Patent: August 2, 2011Assignee: Fujitsu LimitedInventors: Tomoaki Takeyama, Keiko Sasaki, Shinichirou Muro
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Publication number: 20100245988Abstract: An optical amplifier includes a first excitation light source that outputs a first excitation light; a second excitation light source that outputs a second excitation light; a first amplifying optical fiber doped with a rare-earth element and excited by the first excitation light to amplify light input to the first amplifying optical fiber; and a second amplifying optical fiber doped with a rare-earth element and excited by the second excitation light to amplify the light from the first amplifying optical fiber. A ratio between the intensity of the first excitation light and the intensity of the second excitation light is controlled according to the number of signal lights wavelength-multiplexed in the light input.Type: ApplicationFiled: January 23, 2010Publication date: September 30, 2010Applicant: FUJITSU LIMITEDInventors: Tomoaki TAKEYAMA, Keiko Sasaki, Shinichirou Muro
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Patent number: 7722812Abstract: A reaction disk provides a compact and inexpensive design of an automatic analyzer so that the constituents in a suspension, such as blood sampled from a patient at a sick room or other place in a hospital, can be analyzed immediately and quantitatively. A separation cell and a determination cell are formed in a same reaction disk so as to maintain an upright position even during rotation of the both cells. The separation cell is formed to prevent poured suspension therein from flowing out during centrifugal separation, and a supernatant separated by centrifugation from the suspension contained in the separation cell is dispensed to the determination cell to analyze a target substance in the supernatant.Type: GrantFiled: December 7, 2004Date of Patent: May 25, 2010Assignee: Wako Pure Chemical Industries, Ltd.Inventors: Kazuhito Tanimoto, Keiko Sasaki, Masayoshi Hayashi, Hishiri Komiyama
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Patent number: 7643206Abstract: An optical amplifier of the present invention comprises: first and second optical amplifying sections connected in series to each other between an input port and an output port; a first variable optical attenuator arranged on a former stage of the first optical amplifying section; a second variable optical attenuator arranged between the first and second optical amplifying sections; an optical amplification control section that controls the first and second optical amplifying sections; and an optical attenuation control section that controls the first and second variable optical attenuators.Type: GrantFiled: November 13, 2006Date of Patent: January 5, 2010Assignee: Fujitsu LimitedInventors: Tomoaki Takeyama, Keiko Sasaki, Shinichirou Muro
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Publication number: 20090297143Abstract: In an optical transmission apparatus, levels of signal lights obtained by demultiplexing a WDM signal and corresponding to channels are detected, based on which a channel in which a signal is transmitted and a channel in which no signal is transmitted are determined. An attenuation amount of a channel in which no signal is transmitted in a predetermined range from the channel in which the signal is transmitted is set to a value equal to an attenuation amount of the channel in which the signal is transmitted. An attenuation amount of a channel in which no signal is transmitted out of the predetermined range from the channel in which the signal is transmitted is set to a value larger than the attenuation amount of the channel in which the signal is transmitted. The signal lights are attenuated based on the values and multiplexed.Type: ApplicationFiled: April 28, 2009Publication date: December 3, 2009Applicant: FUJITSU LIMITEDInventors: Tomoaki Takeyama, Ichiro Nakajima, Keiko Sasaki, Shinichirou Muro, Etsuko Hayashi
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Patent number: 7616848Abstract: In an optical transmission apparatus, optical power of each of wavelength contained in a wavelength multiplexing signal is measured, a measured value of the optical power of each wavelength is compared with a predetermined threshold value, a total value of the measured values of the optical power, which are equal to or larger than the threshold value, is calculated as a total value of signal beam power, and a total value of the measured values of the optical power, which are less then the threshold value, is calculated as a total value of ASE power. The number of the measured values of the optical power, which are equal to or larger than the threshold value, is calculated as a wavelength count of the signal beams contained in the wavelength multiplexing signal. A signal-to-ASE ratio is calculated from the total value of the signal beam power and the total value of the ASE power.Type: GrantFiled: February 23, 2007Date of Patent: November 10, 2009Assignee: Fujitsu LimitedInventors: Tomoaki Takeyama, Keiko Sasaki, Shinichirou Muro, Etsuko Hayashi
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Publication number: 20090262216Abstract: An image capturing apparatus is disclosed. An image capturing section captures an image of light and obtains image data. An image display section displays the image data obtained by the image capturing section with a predetermined number of pixels. A storage section stores the image data obtained by the image capturing section. An interface section is connectable to an external storage device. A control section causes the image data obtained by the image capturing section to be stored to the external storage device connected through the interface section, when the captured image data are stored to the external storage device, the image data whose number of pixel exceeds the predetermined number of pixels to be converted into image data having the predetermined number of pixels, and the converted image data to be stored to the storage section.Type: ApplicationFiled: April 16, 2009Publication date: October 22, 2009Inventor: Keiko Sasaki
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Publication number: 20090206437Abstract: A photo-detecting apparatus includes a photodiode that coverts light into electricity, a reverse-voltage switching unit that switches a reverse voltage to be applied to the photodiode, a current-difference detecting unit that detects a change in an output current of the photodiode occurring due to switching of the reverse voltage as a current difference, a correspondence retaining unit that retains a correspondence between the current difference and a dark current, a dark-current calculating unit that calculates a dark current by referring to the correspondence based on the current difference detected by the current-difference detecting unit, and a dark-current correcting unit that corrects the output current of the photodiode based on the dark current to find a photocurrent obtained through photoelectric conversion.Type: ApplicationFiled: September 30, 2008Publication date: August 20, 2009Applicant: Fujitsu LimitedInventors: Tomoaki Takeyama, Keiko Sasaki, Shinichirou Muro
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Publication number: 20090129987Abstract: Provided is a composite multi-reagent vessel for an autoanalyzer, which prevents incorrectly combining a plurality of reagents including a standard or a control, and eliminates the work for combining reagents for analysis. A plurality of containers are each capable of standing on their own and are connected together each with an opening portion at the top and each being detachable and capable of standing as the connected reagent containers, thereby forming the composite multi-reagent vessel for the autoanalyzer to have reagents for analyzing the same analytical item therein, and a small container to have a reagent therein that is held on a step or a concave portion formed at a shoulder portion of any of the connected reagent containers.Type: ApplicationFiled: May 16, 2006Publication date: May 21, 2009Applicant: WAKO PURE CHEMICAL INDUSTRIES, LTD.Inventors: Kazuhito Tanimoto, Keiko Sasaki, Shinji Maeda, Hishiri Komiyama
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Publication number: 20090098024Abstract: There is provided a dispensing mechanism for a liquid to be dispensed that does not damage microspherical bodies such as an erythrocyte and a liposome in the liquid to be dispensed when the liquid to be dispensed such as a sample and test liquid is sucked/discharged with a pipette.Type: ApplicationFiled: April 24, 2006Publication date: April 16, 2009Applicant: WAKO PURE CHEMICAL INDUSTRIES, LTD.Inventors: Masayoshi Hayashi, Kazuhito Tanimoto, Keiko Sasaki
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Publication number: 20080239467Abstract: An optical amplifier including: a first amplifying unit amplifying an input light by utilizing a first excitation light and thereby outputting a first amplified light; a second amplifying unit amplifying the first amplified light by utilizing a second excitation light and thereby outputting a second amplified light; and a control unit detecting a first absorption rate of the first excitation light and a second absorption rate of the second excitation light, and controlling a level of the first excitation light and a level of second excitation light based on the first absorption rate and the second absorption rate. The first absorption rate corresponds to a ratio of the first excitation light absorbed in the first amplifying unit, and the second absorption rate corresponds to a ratio of the second excitation light absorbed in the second amplifying unit.Type: ApplicationFiled: March 24, 2008Publication date: October 2, 2008Applicant: Fujitsu LimitedInventors: Tomoaki TAKEYAMA, Keiko Sasaki, Shinichirou Muro
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Publication number: 20080074731Abstract: An optical amplifier reducing gain deviation caused by wavelength arrangement has a first-stage optical amplifying unit, an attenuator, a second-stage optical amplifying unit, an automatic gain controller controlling the first- and second-stage optical amplifying units so that a gain of signal light outputted from the second-stage optical amplifying unit to signal light inputted to the first-stage optical amplifying unit is constant, and an attenuation amount controller controlling an attenuation amount at the attenuator to adjust gain-versus-wavelength characteristic at the automatic-gain-controlled first- and second-stage optical amplifying units on the basis of information on wavelength arrangement and an input level of the signal light inputted to the first-stage optical amplifying unit so that gain slope characteristic at the first- and second-stage optical amplifying units due to the wavelength arrangement and the input level is flattened.Type: ApplicationFiled: August 27, 2007Publication date: March 27, 2008Applicant: Fujitsu LimitedInventors: Tomoaki Takeyama, Keiko Sasaki, Shinichirou Muro
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Patent number: 7330303Abstract: A wavelength division multiplexed optical amplifier, enabling elimination of the problems of oscillation and fluctuation in output due to ASE at the time of a rapid change in the number of input wavelengths, provided with a first-stage optical amplifying unit, second-stage optical amplifying unit, a common AGC circuit for common AGC of the first and second optical amplifying units, and a pumping light distribution means for applying pumping light to the first and second-stage optical amplifying units with a predetermined distribution ratio.Type: GrantFiled: March 19, 2004Date of Patent: February 12, 2008Assignee: Fujitsu LimitedInventors: Takashi Sato, Kazunari Tsubaki, Tomoaki Takeyama, Keiko Sasaki, Shinya Inagaki
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Publication number: 20070274725Abstract: In an optical transmission apparatus, optical power of each of wavelength contained in a wavelength multiplexing signal is measured, a measured value of the optical power of each wavelength is compared with a predetermined threshold value, a total value of the measured values of the optical power, which are equal to or larger than the threshold value, is calculated as a total value of signal beam power, and a total value of the measured values of the optical power, which are less then the threshold value, is calculated as a total value of ASE power. The number of the measured values of the optical power, which are equal to or larger than the threshold value, is calculated as a wavelength count of the signal beams contained in the wavelength multiplexing signal. A signal-to-ASE ratio is calculated from the total value of the signal beam power and the total value of the ASE power.Type: ApplicationFiled: February 23, 2007Publication date: November 29, 2007Applicant: Fujitsu LimitedInventors: Tomoaki Takeyama, Keiko Sasaki, Shinichirou Muro, Etsuko Hayashi
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Patent number: 7296940Abstract: An optical apparatus of the invention has a fusion splice portion where respective ends of two optical fibers each having a core, a cladding, and a UV coat portion provided on the outside of the cladding are fusion spliced, and a re-coat portion which re-coats a portion where the UV coat portion is removed in the vicinity of the fusion splice portion is formed using a material capable of absorbing light radiated from the fusion splice portion. As a result light which is radiated from the fusion splice portion can be reliably prevented from coupling into another optical fiber adjacent to an outside of the re-coat portion.Type: GrantFiled: October 19, 2006Date of Patent: November 20, 2007Assignee: Fujitsu LimitedInventors: Norifumi Shukunami, Hiroyuki Furukawa, Keiko Sasaki
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Publication number: 20070229941Abstract: An optical amplifier of the present invention comprises: first and second optical amplifying sections connected in series to each other between an input port and an output port; a first variable optical attenuator arranged on a former stage of the first optical amplifying section; a second variable optical attenuator arranged between the first and second optical amplifying sections; an optical amplification control section that controls the first and second optical amplifying sections; and an optical attenuation control section that controls the first and second variable optical attenuators.Type: ApplicationFiled: November 13, 2006Publication date: October 4, 2007Applicant: FUJITSU LIMITEDInventors: Tomoaki Takeyama, Keiko Sasaki, Shinichirou Muro
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Patent number: 7236294Abstract: A contrivance, if a WDM signal state changes, is to improve an optical transmission quality by compensating gain flatness. A first excitation control unit sets a first optical pumping light source unit to emit excitation power needed to get the same amplifying operating level of a first amplifying medium as at the time of a maximum wavelength count when allocating wavelengths after a change in wavelength count at an equal interval in a wavelength range. A wavelength allocation bias estimation unit compares a present monitor value of optical power after outputting of a gain equalizer 13 with wavelength equi-allocation power associated with the recognized wavelength count, and thus estimates a wavelength allocation bias occurred as a concomitant of the change in the wavelength count. A primary gradient calculation unit obtains a primary gradient quantity defines as a gain deviation from the wavelength allocation bias.Type: GrantFiled: March 2, 2005Date of Patent: June 26, 2007Assignee: Fujitsu LimitedInventors: Tomoaki Takeyama, Shinya Inagaki, Yoshihito Onoda, Takashi Shimizu, Keiko Sasaki
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Publication number: 20070087429Abstract: [Problem]A reaction disk capable of compact and inexpensive design of an automatic analyzer is provided so that the constituents in suspension such as blood sampled from a patient at a sick room or other place in a hospital can be analyzed immediately and quantitatively. [Means of Solution]A separation cell and a determination cell are formed in a same reaction disk so as to keep their upright position even during rotation of the both cells, the separation cell being formed to prevent poured suspension therein from flowing out during centrifugal separation, and a supernatant separated by centrifugation from the suspension contained in the separation cell being dispensed to the determination cell to analyze a target substance in the supernatant. [Selected Drawing] FIG.Type: ApplicationFiled: December 7, 2004Publication date: April 19, 2007Inventors: Kazuhito Tanimoto, Keiko Sasaki, Masayoshi Hayashi, Hishiri Komiyama
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Publication number: 20070041084Abstract: The present invention has an object to provide an optical amplifier capable of realizing a good response characteristic in a wide frequency band, even when a population inversion state is formed by a pumping light supplied to an optical amplification medium and an ASE light generated in the optical amplification medium. To this end, in the optical amplifier according to the present invention, a delayed phase matching fiber in which a first fiber whose response speed is relatively low is arranged on the input side and a second fiber whose response speed is relatively high is arranged on the output side, is used as the optical amplification medium doped with a rare-earth element.Type: ApplicationFiled: October 26, 2006Publication date: February 22, 2007Applicant: Fujitsu LimitedInventors: Takashi Shimizu, Shinya Inagaki, Tomoaki Takeyama, Keiko Sasaki
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Publication number: 20070036499Abstract: An optical apparatus of the invention has a fusion splice portion where respective ends of two optical fibers each having a core, a cladding, and a UV coat portion provided on the outside of the cladding are fusion spliced, and a re-coat portion which re-coats a portion where the UV coat portion is removed in the vicinity of the fusion splice portion is formed using a material capable of absorbing light radiated from the fusion splice portion. As a result light which is radiated from the fusion splice portion can be reliably prevented from coupling into another optical fiber adjacent to an outside of the re-coat portion.Type: ApplicationFiled: October 19, 2006Publication date: February 15, 2007Applicant: FUJITSU LIMITEDInventors: Norifumi Shukunami, Hiroyuki Furukawa, Keiko Sasaki