Patents by Inventor Tohru Kohno
Tohru Kohno 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: 9651631Abstract: In order to provide a calculation method for reproducing solar cell characteristics with high accuracy by using data of a short-circuit current, an open-circuit voltage and the maximum power operation point of a solar cell in a temperature and a solar radiation intensity in a standard state, parameter values for determining characteristics in the standard state are calculated by using data of the short-circuit current, the open-circuit voltage and the maximum power operation point of the solar cell in the temperature and the solar radiation intensity in the standard state. Next, temperature coefficients of the open-circuit voltage and the reverse saturation current are calculated by using the calculated parameters, and a short-circuit current, an open-circuit voltage and the maximum power operation point at a given temperature are calculated.Type: GrantFiled: January 27, 2012Date of Patent: May 16, 2017Assignee: Hitachi, Ltd.Inventors: Tohru Kohno, Akihiro Nakamura, Tomoharu Nakamura
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Patent number: 9535135Abstract: A method for calculating a solar radiation amount is provided, which enables the prediction of a solar radiation amount with consideration also given to the small movement of a cloud that affects a power generation amount generated by a PV array and thereby improves the accuracy of prediction of the power generation amount generated by the PV array. From a measured output value of a solar panel, solar radiation and a temperature parameter are extracted. An output of a PV is calculated from the extracted solar radiation and temperature parameter. The calculated value is correlated with the measured value. A temperature correction coefficient is obtained so that a correlation coefficient is highest, and a solar radiation amount is calculated using the obtained correlation coefficient.Type: GrantFiled: November 8, 2013Date of Patent: January 3, 2017Assignee: Hitachi, Ltd.Inventors: Masaaki Fujimori, Tohru Kohno
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Patent number: 9506971Abstract: A low-cost failure diagnosis method, without addition of a measuring unit and a communication unit, provided for a solar battery system, of calculating a working temperature and the number of failed solar battery modules in a solar battery array, by calculating a solar radiation amount while updating a predetermined coefficient as a ratio between a short-circuit current and a working current in accordance with state of the solar battery array and using measured data having the working current and working voltage measured with a detection unit.Type: GrantFiled: August 26, 2013Date of Patent: November 29, 2016Assignee: Hitachi, Ltd.Inventors: Tohru Kohno, Akihiro Nakamura, Tomoharu Nakamura, Koki Morikawa
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Patent number: 9304161Abstract: In order to provide a system which detects and classifies abnormality in a solar battery even during power generation, an output voltage and an output current of the solar battery during power generation are detected, and a solar battery characteristic equation and a threshold value for detecting an abnormal state are calculated using the detected voltage value and current value and the measurement data of an external environment measurement unit. The kind of abnormal state of the solar battery is classified using the calculation result of the characteristic equation and the threshold value.Type: GrantFiled: January 25, 2012Date of Patent: April 5, 2016Assignee: Hitachi, Ltd.Inventors: Akihiro Nakamura, Tohru Kohno, Tomoharu Nakamura
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Patent number: 9207700Abstract: In a case in which a local solution to current-voltage characteristics is generated by way of a partial shade, it has been difficult to perform control for causing a solar cell to operate at a maximum power point efficiently in terms of power and at a low cost. During steady state operation, an MPPT control unit 1 for performing the normal hill climbing method is selected, and if the change amount of the output current of the solar cell is greater than or equal to a predetermined threshold, an MPPT control unit 2 for increasing the variation width of the output voltage of the solar cell to greater than the hill climbing method is selected. By way of such control, it is possible to achieve both efficient operation in a steady state and avoidance of a local solution to a partial shade at a low cost.Type: GrantFiled: February 21, 2011Date of Patent: December 8, 2015Assignee: Hitachi, Ltd.Inventors: Tohru Kohno, Motoo Futami, Hiromu Kakuya
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Patent number: 9177504Abstract: To provide an image display device having a circuit for solving burning phenomenon without increasing the size of the circuit. An image display device is provided having a display unit formed using display devices, a signal line for inputting a display signal voltage to the display unit, and a display control unit for controlling the display signal voltage, the image display device comprising a detection power source, a switch for causing a current of the detection power source to flow to the display device, a detection circuit for detecting the current, and a detection information storage circuit for storing information, and compensating the display signal voltage, using the information, wherein using a first reference voltage, and current detection is carried out, the detection circuit feeds back the current detected to set a second reference voltage different from the first reference voltage, and carries out current detection.Type: GrantFiled: January 14, 2009Date of Patent: November 3, 2015Assignees: JAPAN DISPLAY INC., PANASONIC LIQUID CRYSTAL DISPLAY CO., LTD.Inventors: Naruhiko Kasai, Masato Ishii, Tohru Kohno, Hajime Akimoto
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Patent number: 9135858Abstract: Provided is an image display device, which includes: a display area including a plurality of pixels each of which includes a self light-emitting element; and a plurality of signal lines for inputting an image voltage to each of the plurality of pixels, in which: each of the plurality of pixels includes a field-effect transistor for driving the self light-emitting element based on the image voltage which is input through each of the plurality of signal lines to each of the plurality of pixels; the display area is divided into at least two regions including a first region and a second region; and a (channel width-to-channel length) ratio of the field-effect transistor in the first region is smaller than the ratio of any field-effect transistor in the second region.Type: GrantFiled: February 3, 2010Date of Patent: September 15, 2015Assignees: JAPAN DISPLAY INC., CANON KABUSHIKI KAISHAInventors: Takahide Kuranaga, Tohru Kohno, Hajime Akimoto, Hiroshi Kageyama
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Patent number: 8749460Abstract: Provided is an image display device including: a plurality of pixel scanning lines; a plurality of signal lines; and a plurality of pixel circuits corresponding to intersections between the pixel scanning lines and the signal lines. Each of the pixel circuits includes: a driver transistor; a light emitting element for emitting light based on the current supplied from the driver transistor; a pixel switch for generating a potential based on an image signal and a scanning signal; a capacitor element for controlling the driver transistor based on a potential difference caused by the potential supplied from the pixel switch; and a reset switch for setting a potential at an end of the capacitor element to a predetermined state based on a scanning signal supplied from one of the pixel scanning lines preceding the scanning signal which corresponds to the corresponding one of the plurality of pixel circuits.Type: GrantFiled: August 26, 2009Date of Patent: June 10, 2014Assignees: Japan Display Inc., Panasonic Liquid Crystal Display Co., Ltd.Inventors: Hajime Akimoto, Hiroshi Kageyama, Tohru Kohno
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Publication number: 20140136131Abstract: A method for calculating a solar radiation amount is provided, which enables the prediction of a solar radiation amount with consideration also given to the small movement of a cloud that affects a power generation amount generated by a PV array and thereby improves the accuracy of prediction of the power generation amount generated by the PV array. From a measured output value of a solar panel, solar radiation and a temperature parameter are extracted. An output of a PV is calculated from the extracted solar radiation and temperature parameter. The calculated value is correlated with the measured value. A temperature correction coefficient is obtained so that a correlation coefficient is highest, and a solar radiation amount is calculated using the obtained correlation coefficient.Type: ApplicationFiled: November 8, 2013Publication date: May 15, 2014Applicant: Hitachi, LtdInventors: Masaaki FUJIMORI, Tohru KOHNO
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Publication number: 20140058688Abstract: A low-cost failure diagnosis method, without addition of a measuring unit and a communication unit, provided for a solar battery system, of calculating a working temperature and the number of failed solar battery modules in a solar battery array, by calculating a solar radiation amount while updating a predetermined coefficient as a ratio between a short-circuit current and a working current in accordance with state of the solar battery array and using measured data having the working current and working voltage measured with a detection unit.Type: ApplicationFiled: August 26, 2013Publication date: February 27, 2014Applicant: Hitachi, Ltd.Inventors: Tohru KOHNO, Akihiro NAKAMURA, Tomoharu NAKAMURA, Koki MORIKAWA
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Patent number: 8643574Abstract: To determine a deterioration and maintain a high-quality image without unevenness of brightness by performing a precise correction, a detection scanning line for selecting a pixel which detects a deterioration of a pixel, a detection line for informing the outside of the display area of the property of a pixel selected for detecting the deterioration, a deterioration determination means for determining a deterioration amount based on a voltage corresponding to a current detected by the detection line, and a deterioration correction means (computation circuit) for reflecting the determination result of the deterioration determination means in image data supplied to the pixel, are provided.Type: GrantFiled: July 8, 2008Date of Patent: February 4, 2014Assignees: Japan Display Inc., Panasonic Liquid Crystal Display Co., Ltd.Inventors: Mitsuhide Miyamoto, Tohru Kohno, Masato Ishii, Naruhiko Kasai, Hajime Akimoto
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Patent number: 8610646Abstract: An organic electroluminescence display device is provided having a display section including a plurality of pixels arranged in a matrix; and a detection section for detecting a luminance characteristic of an OLED element in each of the pixels. The detection section includes a first path for allowing a detected characteristic value to pass therethrough and a second path for attenuating the detected characteristic value. A first switch is provided for the first path whereas a second switch is provided for the second path, the second switch being opened when the first switch is closed. The detected characteristic value having passed through any one of the first path and the second path is input to a same analog-to-digital converter to be converted into a digital quantity.Type: GrantFiled: January 9, 2009Date of Patent: December 17, 2013Assignees: Japan Display Inc., Panasonic Liquid Crysal Display Co., Ltd.Inventors: Tohru Kohno, Hajime Akimoto, Naruhiko Kasai, Masato Ishii
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Patent number: 8605062Abstract: To shorten the measuring time of the characteristics of light emission of OLED elements for feedback to image data for image display in an organic EL display device. Pixels that emit red lights, pixels that emit green lights, and pixels that emit blue lights are arranged on a screen in a matrix manner. A detection system is provided on the upper side of the screen. A detection line extending from the detection system is coupled to the respective pixels through analog switches and digital switches controlled by switch controlling lines. A detection scanning circuit is provided on the right side of the screen. Detection switch controlling lines extend from the detection scanning circuit. By appropriately selecting the analog switches, the switch controlling lines, and the detection switch controlling lines, the voltage-current characteristics of plural pixels are measured at the same time.Type: GrantFiled: March 3, 2008Date of Patent: December 10, 2013Assignees: Japan Display Inc., Panasonic Liquid Crystal Display Co., Ltd.Inventors: Tohru Kohno, Mitsuhide Miyamoto, Hajime Akimoto, Naruhiko Kasai, Masato Ishii
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Patent number: 8605069Abstract: An image display device includes switches directly connected a constant current source to a self-luminous element to be able to detect a characteristic of the self-luminous element, generate a coordinates and convert information of the characteristic and coordinates into a system communication signal, transferring an input with a temperature variation to a system side.Type: GrantFiled: February 8, 2008Date of Patent: December 10, 2013Assignees: Hitachi Displays, Ltd., Panasonic Liquid Crystal Display Co., Ltd.Inventors: Naruhiko Kasai, Masato Ishii, Mitsuhide Miyamoto, Tohru Kohno, Hajime Akimoto
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Publication number: 20130311121Abstract: In order to provide a calculation method for reproducing solar cell characteristics with high accuracy by using data of a short-circuit current, an open-circuit voltage and the maximum power operation point of a solar cell in a temperature and a solar radiation intensity in a standard state, parameter values for determining characteristics in the standard state are calculated by using data of the short-circuit current, the open-circuit voltage and the maximum power operation point of the solar cell in the temperature and the solar radiation intensity in the standard state. Next, temperature coefficients of the open-circuit voltage and the reverse saturation current are calculated by using the calculated parameters, and a short-circuit current, an open-circuit voltage and the maximum power operation point at a given temperature are calculated.Type: ApplicationFiled: January 27, 2012Publication date: November 21, 2013Applicant: Hitachi, Ltd.Inventors: Tohru Kohno, Akihiro Nakamura, Tomoharu Nakamura
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Publication number: 20130300449Abstract: In order to provide a system which detects and classifies abnormality in a solar battery even during power generation, an output voltage and an output current of the solar battery during power generation are detected, and a solar battery characteristic equation and a threshold value for detecting an abnormal state are calculated using the detected voltage value and current value and the measurement data of an external environment measurement unit. The kind of abnormal state of the solar battery is classified using the calculation result of the characteristic equation and the threshold value.Type: ApplicationFiled: January 25, 2012Publication date: November 14, 2013Applicant: Hitachi, Ltd.Inventors: Akihiro Nakamura, Tohru Kohno, Tomoharu Nakamura
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Patent number: 8514153Abstract: In a display mode, a signal driving circuit (DAC) transmits image signals to the pixels selected by a scanning circuit for display and first switches of switch units. Then, a power supply circuit supplies a current corresponding to the transmitted signal to the pixels. Then, organic EL elements provided in the pixels are driven to emit light, thereby displaying an image. In order to correct the deterioration of the organic EL elements, first, a constant current flows from a current source to the organic EL elements of the pixels selected by a scanning circuit for detection and second switches and a voltage corresponding to the constant current applied to the organic EL element is detected. The detected voltage is input to an AD converter through a buffer amplifier, and the AD converter converts the voltage into a digital value, and transmits the digital value to a signal correction control unit. When the organic EL element deteriorates, the detected digital value varies.Type: GrantFiled: July 17, 2008Date of Patent: August 20, 2013Assignees: Hitachi Displays, Ltd., Panasonic Liquid Crystal Display Co., Ltd.Inventors: Tohru Kohno, Mitsuhide Miyamoto, Hajime Akimoto, Naruhiko Kasai, Masato Ishii
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Patent number: 8477086Abstract: In an organic EL display, correction is made for a difference in screen luminance between the case of measuring characteristics of OLED elements, and the case of not measuring the characteristics of the OLED elements. A data line for feeding image data items, and a detection line for measuring the characteristics of the OLED elements are connected to respective pixels. Detection of the characteristics of the OLED elements is executed by utilizing a specified period of a frame period. Because an image-displaying period is limited in a frame where measurement of the characteristics of the OLED element 11 is executed, the luminance undergoes deterioration.Type: GrantFiled: February 7, 2008Date of Patent: July 2, 2013Assignees: Hitachi Displays, Ltd., Panasonic Liquid Crystal Display Co., Ltd.Inventors: Mitsuhide Miyamoto, Tohru Kohno, Masato Ishii, Naruhiko Kasai, Hajime Akimoto
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Patent number: 8427400Abstract: Provided is an image display device in which deterioration of a self-light-emitting element within a pixel is corrected accurately. A detection unit detects, within a detection period, a difference in characteristics between self-light-emitting elements of adjacent pixels. A first subtraction circuit outputs a differential voltage between a reference voltage and an image voltage to a self-light-emitting element that is determined by the detection unit as a deteriorated element. An amplifier amplifies an output of the first subtraction circuit with a gain [1/{1-(?/100)}]1/2 when a driver transistor is driven in a saturation region. The amplifier amplifies the output of the first subtraction circuit with a gain [1/{1-(?/100)}] when the driver transistor is driven in a linear region. A differential between the reference voltage and an output of the amplifier obtained by a second subtraction circuit is used as a corrected image voltage.Type: GrantFiled: June 3, 2009Date of Patent: April 23, 2013Assignees: Hitachi Displays, Ltd., Panasonic Liquid Crystal Display Co., Ltd.Inventors: Tohru Kohno, Hajime Akimoto, Naruhiko Kasai, Masato Ishii
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Publication number: 20130041511Abstract: In a case in which a local solution to current-voltage characteristics is generated by way of a partial shade, it has been difficult to perform control for causing a solar cell to operate at a maximum power point efficiently in terms of power and at a low cost. During steady state operation, an MPPT control unit 1 for performing the normal hill climbing method is selected, and if the change amount of the output current of the solar cell is greater than or equal to a predetermined threshold, an MPPT control unit 2 for increasing the variation width of the output voltage of the solar cell to greater than the hill climbing method is selected. By way of such control, it is possible to achieve both efficient operation in a steady state and avoidance of a local solution to a partial shade at a low cost.Type: ApplicationFiled: February 21, 2011Publication date: February 14, 2013Applicant: Hitachi, Ltd.Inventors: Tohru Kohno, Motoo Futami, Hiromu Kakuya