Patents by Inventor NAOKO GOTOH
NAOKO GOTOH 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: 10614757Abstract: An organic EL panel 10 is a bendable display panel including a plurality of pixel circuits 60 each having a light emitting element and a drive element. A data line drive circuit 15 performs, by driving data lines, an operation of writing a voltage to a control terminal of the drive element and an operation of measuring a current flowing through the drive element for the pixel circuits 60 selected by a scanning line drive circuit 14. A bending detection unit 90 detects a bending state of the organic EL panel 10 based on a measurement result of the current flowing through the drive element. A correction unit 80 corrects a video signal VS1 based on the detected bending state. With this, the bending state of a screen is detected and a change in brightness or color when the screen is bent is prevented.Type: GrantFiled: November 25, 2016Date of Patent: April 7, 2020Assignee: SHARP KABUSHIKI KAISHAInventors: Kazuo Takizawa, Noritaka Kishi, Naoko Gotoh, Hideki Uchida, Katsuhiro Kikuchi
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Patent number: 10510285Abstract: A measurement circuit includes a plurality of measurement units, performs, at a same timing, a main measurement for measuring a current or a voltage with respect to a pixel circuit with supplying a measurement voltage to a part of the measurement units and a dummy measurement for measuring a current or a voltage with supplying a dummy signal to remaining measurement units, and performs a calculation on a result of the main measurement and a result of the dummy measurement. As the dummy signal, a signal with which a value to be measured is approximately zero is used. The measurement result of the current or the voltage is used for correcting a video signal. With this, a display device which can remove noise in measurement when measuring the current or the voltage with respect to the pixel circuit is provided.Type: GrantFiled: January 27, 2016Date of Patent: December 17, 2019Assignee: SHARP KABUSHIKI KAISHAInventors: Noritaka Kishi, Hiroyuki Furukawa, Katsuya Otoi, Kazuyoshi Yoshiyama, Tamotsu Sakai, Naoko Gotoh
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Patent number: 10319305Abstract: A current measurement circuit measures a current flowing through a drive transistor when a plurality of measurement voltages are written to a pixel circuit in a switching manner, and a current flowing through an organic EL element when another plurality of measurement voltages are written to the pixel circuit in a switching manner. A correction unit obtains a threshold voltage and a gain of the drive transistor and the organic EL element with respect to each pixel circuit based on a measured current, determines in which operation region the drive transistor operates between a saturation region and a triode region with respect to each pixel circuit based on the video signal, and corrects the video signal in accordance with the operation region of the drive transistor. Since the drive transistor operates both in the saturation region and the triode region, it is possible to reduce a power supply voltage and reduce power consumption of a display device.Type: GrantFiled: February 3, 2016Date of Patent: June 11, 2019Assignee: SHARP KABUSHIKI KAISHAInventors: Noritaka Kishi, Hiroyuki Furukawa, Katsuya Otoi, Kazuyoshi Yoshiyama, Tamotsu Sakai, Naoko Gotoh
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Patent number: 10269301Abstract: In a current measurement period of a pixel circuit (20), a measurement voltage is applied to a non-inverting input terminal of an operational amplifier (31), switches (35, 36) turn on, and a switch (37) turns off. Next, the switch (36) turns off, and a capacitor (32) is charged with charge of a current flowing through the pixel circuit (20). Next, the switch (35) turns off, the switch (37) turns on, a constant current flows through a current source (33), and a voltage of a second terminal (terminal connected to an output terminal of the operational amplifier (31)) of the capacitor (32) decreases. A voltage comparator (42) and a counter (43) measure the current flowing through the pixel circuit (20) by measuring time until a voltage of the second terminal of the capacitor reaches a voltage Vcomp. A video signal VS1 is corrected based on a current measurement result.Type: GrantFiled: March 18, 2016Date of Patent: April 23, 2019Assignee: SHARP KABUSHIKI KAISHAInventors: Noritaka Kishi, Hiroyuki Furukawa, Katsuya Otoi, Kazuyoshi Yoshiyama, Tamotsu Sakai, Naoko Gotoh
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Publication number: 20190057649Abstract: An organic EL panel 10 is a bendable display panel including a plurality of pixel circuits 60 each having a light emitting element and a drive element. A data line drive circuit 15 performs, by driving data lines, an operation of writing a voltage to a control terminal of the drive element and an operation of measuring a current flowing through the drive element for the pixel circuits 60 selected by a scanning line drive circuit 14. A bending detection unit 90 detects a bending state of the organic EL panel 10 based on a measurement result of the current flowing through the drive element. A correction unit 80 corrects a video signal VS1 based on the detected bending state. With this, the bending state of a screen is detected and a change in brightness or color when the screen is bent is prevented.Type: ApplicationFiled: November 25, 2016Publication date: February 21, 2019Inventors: Kazuo TAKIZAWA, Noritaka KISHI, Naoko GOTOH, Hideki UCHIDA, Katsuhiro KIKUCHI
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Publication number: 20180061328Abstract: In a current measurement period of a pixel circuit (20), a measurement voltage is applied to a non-inverting input terminal of an operational amplifier (31), switches (35, 36) turn on, and a switch (37) turns off. Next, the switch (36) turns off, and a capacitor (32) is charged with charge of a current flowing through the pixel circuit (20). Next, the switch (35) turns off, the switch (37) turns on, a constant current flows through a current source (33), and a voltage of a second terminal (terminal connected to an output terminal of the operational amplifier (31)) of the capacitor (32) decreases. A voltage comparator (42) and a counter (43) measure the current flowing through the pixel circuit (20) by measuring time until a voltage of the second terminal of the capacitor reaches a voltage Vcomp. A video signal VS1 is corrected based on a current measurement result.Type: ApplicationFiled: March 18, 2016Publication date: March 1, 2018Inventors: Noritaka KISHI, Hiroyuki FURUKAWA, Katsuya OTOI, Kazuyoshi YOSHIYAMA, Tamotsu SAKAI, Naoko GOTOH
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Publication number: 20180033372Abstract: A current measurement circuit measures a current flowing through a drive transistor when a plurality of measurement voltages are written to a pixel circuit in a switching manner, and a current flowing through an organic EL element when another plurality of measurement voltages are written to the pixel circuit in a switching manner. A correction unit obtains a threshold voltage and a gain of the drive transistor and the organic EL element with respect to each pixel circuit based on a measured current, determines in which operation region the drive transistor operates between a saturation region and a triode region with respect to each pixel circuit based on the video signal, and corrects the video signal in accordance with the operation region of the drive transistor. Since the drive transistor operates both in the saturation region and the triode region, it is possible to reduce a power supply voltage and reduce power consumption of a display device.Type: ApplicationFiled: February 3, 2016Publication date: February 1, 2018Applicant: SHARP KABUSHIKI KAISHAInventors: NORITAKA KISHI, HIROYUKI FURUKAWA, KATSUYA OTOI, KAZUYOSHI YOSHIYAMA, TAMOTSU SAKAI, NAOKO GOTOH
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Publication number: 20170365205Abstract: A measurement circuit includes a plurality of measurement units, performs, at a same timing, a main measurement for measuring a current or a voltage with respect to a pixel circuit with supplying a measurement voltage to a part of the measurement units and a dummy measurement for measuring a current or a voltage with supplying a dummy signal to remaining measurement units, and performs a calculation on a result of the main measurement and a result of the dummy measurement. As the dummy signal, a signal with which a value to be measured is approximately zero is used. The measurement result of the current or the voltage is used for correcting a video signal. With this, a display device which can remove noise in measurement when measuring the current or the voltage with respect to the pixel circuit is provided.Type: ApplicationFiled: January 27, 2016Publication date: December 21, 2017Inventors: NORITAKA KISHI, HIROYUKI FURUKAWA, KATSUYA OTOI, KAZUYOSHI YOSHIYAMA, TAMOTSU SAKAI, NAOKO GOTOH