Patents by Inventor Keitaro Yamashita
Keitaro Yamashita 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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Publication number: 20210142724Abstract: The present disclosure provides a display driving device, method and an OLED display device, and the display driving device includes: an interface module, configured to receive image data of a display chip and sending a first scanning signal in each of frame periods; a frame buffer, configured to send a buffer signal after receiving the first scanning signal from the interface module; a timing controller, configured to send a second scanning signal to the display panel according to the buffer signal sent by the frame buffer; in response to the display driving device is switched from a screen self-refresh mode to a vertical synchronization mode, the delay time between the second scanning signal and the buffer signal gradually decreases, one frame period by one frame period, to zero or gradually increases, one frame period by one frame period, to duration of one frame period.Type: ApplicationFiled: November 6, 2020Publication date: May 13, 2021Applicant: Everdisplay Optronics (Shanghai) Co.,Ltd.Inventors: Keitaro YAMASHITA, Chungche TSOU, Yinan LIANG, Shaodong MA
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Publication number: 20210142723Abstract: A driving method includes: determining a starting luminance LS of a to-be-adjusted frame image; determining an average luminance LAVE(n) of the to-be-adjusted frame image during a nth duty period; determining a reference luminance flow rate ?L that indicates a current change rate of a storage capacitor storing a data signal for a display element; determining a time length TF of a reference frame image; determining a number k of black strips in the to-be-adjusted frame image; calculating a duty ratio of a pulse driving signal of the to-be-adjusted frame image during the nth duty period based on the starting luminance LS, the average luminance LAVE(n), the reference luminance flow rate ?L, the time length TF, and the number k of the black strips; and driving to display the to-be-adjusted frame image by the adjusted pulse driving signal.Type: ApplicationFiled: September 22, 2020Publication date: May 13, 2021Applicant: Everdisplay Optronics (Shanghai) Co.,Ltd.Inventors: Keitaro YAMASHITA, Shaodong MA, Shanglong WANG, Fei SHEN
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Publication number: 20210134226Abstract: The present disclosure provides a driving method and system for an OILED display panel. The driving method for the OLED display panel includes: controlling a gate line driving circuit of the display panel for each frame image to sequentially output a scanning signal to each gate line of the display panel; and when the gate line driving circuit of the display panel starts to output the scanning signal to one gate line, timing from a starting scanning time of the same scanning gate line; and after the scanning time of the current scanning gate line reaches a preset fixed scanning time, controlling the gate line driving circuit of the display panel to stop outputting the scanning signal to the current scanning gate line. Therefore, the present disclosure does not need to change the gamma curve when the refresh frequency is changed, and screen flicker will not occur, and a seamless dynamic refresh switching of the display panel is realized.Type: ApplicationFiled: April 21, 2020Publication date: May 6, 2021Applicant: EverDisplay Optronics (Shanghai) LimitedInventors: Keitaro YAMASHITA, Shaodong MA, Shanglong WANG, Fei SHEN
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Patent number: 10971074Abstract: An electronic device may include a display such as a light-emitting diode display. The electronic device may be a head-mounted device that provides a virtual reality or augmented reality environment to a user. To reduce artifacts in the display, a display may be operable in both a normal scanning mode and a partial scanning mode. In the normal scanning mode, every row of the display may be enabled to emit light in each frame. In the partial scanning mode, only a subset of the rows of the display may be enabled to emit light in each frame. The display may have a higher refresh rate in the partial scanning mode than in the normal scanning mode. To ensure uniform transistor stress across the display, the scanning driver for the display may scan the disabled rows in the partial scanning mode even though the rows will not be used to emit light.Type: GrantFiled: December 12, 2019Date of Patent: April 6, 2021Assignee: Apple Inc.Inventors: Keitaro Yamashita, Abbas Jamshidi Roudbari, Shin-Hung Yeh, Tsung-Ting Tsai, Shih-Chang Chang, Ting-Kuo Chang, Ki Yeol Byun, Warren S. Rieutort-Louis
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Publication number: 20200372862Abstract: A pixel circuit, a driving method and a display device are provided. The pixel circuit includes: a data writing unit, a driving unit, a light emitting unit and an initialization unit. The initialization unit is configured to initialize a second node with an initialization voltage. The data writing unit is configured to set voltage of a first node to the voltage of a data signal and update voltage of the second node. The driving unit is configured to drive the light emitting unit to emit light according to a control signal. Due to the second node being initialized and compensated by the initialization unit, the storage capacitor leakage paths and the electric leakage of the storage capacitor during the light emitting stage are reduced, thus improving the quality of the displayed image.Type: ApplicationFiled: July 17, 2018Publication date: November 26, 2020Applicant: EverDisplay Optronics (Shanghai) LimitedInventors: Keitaro YAMASHITA, Lina XIAO
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Publication number: 20200118497Abstract: An electronic device may include a display such as a light-emitting diode display. The electronic device may be a head-mounted device that provides a virtual reality or augmented reality environment to a user. To reduce artifacts in the display, a display may be operable in both a normal scanning mode and a partial scanning mode. In the normal scanning mode, every row of the display may be enabled to emit light in each frame. In the partial scanning mode, only a subset of the rows of the display may be enabled to emit light in each frame. The display may have a higher refresh rate in the partial scanning mode than in the normal scanning mode. To ensure uniform transistor stress across the display, the scanning driver for the display may scan the disabled rows in the partial scanning mode even though the rows will not be used to emit light.Type: ApplicationFiled: December 12, 2019Publication date: April 16, 2020Inventors: Keitaro Yamashita, Abbas Jamshidi Roudbari, Shin-Hung Yeh, Tsung-Ting Tsai, Shih-Chang Chang, Ting-Kuo Chang, Ki Yeol Byun, Warren S. Rieutort-Louis
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Patent number: 10546540Abstract: An electronic device may include a display such as a light-emitting diode display. The electronic device may be a head-mounted device that provides a virtual reality or augmented reality environment to a user. To reduce artifacts in the display, a display may be operable in both a normal scanning mode and a partial scanning mode. In the normal scanning mode, every row of the display may be enabled to emit light in each frame. In the partial scanning mode, only a subset of the rows of the display may be enabled to emit light in each frame. The display may have a higher refresh rate in the partial scanning mode than in the normal scanning mode. To ensure uniform transistor stress across the display, the scanning driver for the display may scan the disabled rows in the partial scanning mode even though the rows will not be used to emit light.Type: GrantFiled: September 20, 2019Date of Patent: January 28, 2020Assignee: Apple Inc.Inventors: Keitaro Yamashita, Abbas Jamshidi Roudbari, Shin-Hung Yeh, Tsung-Ting Tsai, Shih-Chang Chang, Ting-Kuo Chang, Ki Yeol Byun, Warren S. Rieutort-Louis
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Publication number: 20200013342Abstract: An electronic device may include a display such as a light-emitting diode display. The electronic device may be a head-mounted device that provides a virtual reality or augmented reality environment to a user. To reduce artifacts in the display, a display may be operable in both a normal scanning mode and a partial scanning mode. In the normal scanning mode, every row of the display may be enabled to emit light in each frame. In the partial scanning mode, only a subset of the rows of the display may be enabled to emit light in each frame. The display may have a higher refresh rate in the partial scanning mode than in the normal scanning mode. To ensure uniform transistor stress across the display, the scanning driver for the display may scan the disabled rows in the partial scanning mode even though the rows will not be used to emit light.Type: ApplicationFiled: September 20, 2019Publication date: January 9, 2020Inventors: Keitaro Yamashita, Abbas Jamshidi Roudbari, Shin-Hung Yeh, Tsung-Ting Tsai, Shih-Chang Chang, Ting-Kuo Chang, Ki Yeol Byun, Warren S. Rieutort-Louis
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Patent number: 10482822Abstract: An electronic device may include a display such as a light-emitting diode display. The electronic device may be a head-mounted device that provides a virtual reality or augmented reality environment to a user. To reduce artifacts in the display, a display may be operable in both a normal scanning mode and a partial scanning mode. In the normal scanning mode, every row of the display may be enabled to emit light in each frame. In the partial scanning mode, only a subset of the rows of the display may be enabled to emit light in each frame. The display may have a higher refresh rate in the partial scanning mode than in the normal scanning mode. To ensure uniform transistor stress across the display, the scanning driver for the display may scan the disabled rows in the partial scanning mode even though the rows will not be used to emit light.Type: GrantFiled: December 19, 2016Date of Patent: November 19, 2019Assignee: Apple Inc.Inventors: Keitaro Yamashita, Abbas Jamshidi Roudbari, Shin-Hung Yeh, Tsung-Ting Tsai, Shih-Chang Chang, Ting-Kuo Chang, Ki Yeol Byun, Warren S. Rieutort-Louis
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Patent number: 10375278Abstract: Electronic devices, storage medium containing instructions, and methods pertain to cancelling noise that results from application of voltages on gates of transistors in a display. One or more compensation or dummy drivers are used to apply a compensation voltage that is an inversion of voltages applied on the gates of the transistors.Type: GrantFiled: September 21, 2017Date of Patent: August 6, 2019Assignee: APPLE INC.Inventors: Keitaro Yamashita, Ting-Kuo Chang, Cheng-Ho Yu, Warren S. Rieutort-Louis
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Patent number: 10311782Abstract: An organic light-emitting diode display may contain an array of display pixels. Each display pixel may have a respective organic light-emitting diode that is controlled by a drive transistor. At low temperatures, it may be necessary to increase the amount of current through an organic light-emitting diode to achieve a desired luminance level. In order to increase the current through the light-emitting diode, the ground voltage level may be lowered. However, this may lead to thin-film transistors within the pixel leaking, which may result in undesirable display artifacts such as bright dots being displayed in a dark image. In order to prevent leakage in the transistors, the transistors may be coupled to separate reference voltage supplies or separate control lines. Additionally, the transistors may be positioned to minimize leakage even at low ground voltage levels.Type: GrantFiled: August 24, 2016Date of Patent: June 4, 2019Assignee: Apple Inc.Inventors: Warren S. Rieutort-Louis, Keitaro Yamashita, Tsung-Ting Tsai, Yun Wang, Ting-Kuo Chang, Cheng-Ho Yu, Shinya Ono
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Patent number: 10249254Abstract: Methods and devices useful in discharging an aberrant charge on the VCOM of an electronic display and harvesting energy from the VCOM of the electronic display are provided. By way of example, a method may include supplying an activation signal to an active switching device of an electronic display. The active switching device is configured to discharge an aberrant charge on a common electrode of the electronic display. The method further includes discharging the aberrant charge by way of the active switching device. Discharging the aberrant charge comprises preventing a possible occurrence of image artifacts from becoming apparent on the electronic display.Type: GrantFiled: January 26, 2016Date of Patent: April 2, 2019Assignee: Apple Inc.Inventors: Kasra Omid-Zohoor, Hyunwoo Nho, Keitaro Yamashita, Majid Gharghi, Sarath Chandrasekhar Venkatesh Kumar, Ting-Kuo Chang, Abbas Jamshidi Roudbari
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Publication number: 20180324331Abstract: Electronic devices, storage medium containing instructions, and methods pertain to cancelling noise that results from application of voltages on gates of transistors in a display. One or more compensation or dummy drivers are used to apply a compensation voltage that is an inversion of voltages applied on the gates of the transistors.Type: ApplicationFiled: September 21, 2017Publication date: November 8, 2018Inventors: Keitaro Yamashita, Ting-Kuo Chang, Cheng-Ho Yu, Warren S. Rieutort-Louis
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Patent number: 10109240Abstract: An electronic device may include a display such as a light-emitting diode display. The electronic device may be a head-mounted device that provides a virtual reality or augmented reality environment to a user. To reduce artifacts in the display, a display may be operable in both a normal scanning mode and a partial scanning mode. In the normal scanning mode, every row of the display may be scanned in each frame. In the partial scanning mode, only a subset of the rows of the display may be scanned in each frame. The display may have a higher refresh rate in the partial scanning mode than in the normal scanning mode. The gate driver circuitry may include a shift register that includes a plurality of register circuits. At least one register circuit may have a first input and a second input that is different than the first input.Type: GrantFiled: January 10, 2017Date of Patent: October 23, 2018Assignee: Apple Inc.Inventors: Shih Chang Chang, Keitaro Yamashita, Shin-Hung Yeh, Ting-Kuo Chang, Abbas Jamshidi Roudbari, Chin-Wei Lin
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Patent number: 10101853Abstract: Thin-film transistor circuitry for a display may include conductive layers such as transparent conductive layers and metal layers and may include dielectric layers. The dielectric layers may include buffer layers, interlayer dielectric, gate insulator, and organic planarization layers. The organic planarization layers may be patterned photolithographically to form vias, trenches, and other structures. Trenches may be formed by removing the planarization layer in a strip. When planarization material is removed for forming a trench or other structure, a step is formed in the planarization material. Metal lines such as data lines and other signal lines may cross steps in the planarization material. To prevent shorts between lines, a step may have protrusions that help eliminate metal etch residue. Vias may be reduced in depth by forming metal bumps and dielectric bumps under the vias and by forming other via structures.Type: GrantFiled: September 8, 2016Date of Patent: October 16, 2018Assignee: Apple Inc.Inventors: Yu Cheng Chen, Keitaro Yamashita, Abbas Jamshidi Roudbari, Hirokazu Yamagata, Ting-Kuo Chang
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Patent number: 10078405Abstract: A touch screen display may include gate line driver circuitry coupled to a display pixel array. The gate driver circuitry may include gate drivers connected in a chain. A given one of the gate drivers may include a set-reset latch. The set-reset latch may have a set input and a reset input. A logic gating circuit such as a logic NOR gate may have an output directly connected to the set input. The NOR gate may have a first input coupled to an output of a preceding gate driver in the chain and a second input coupled to an output of a succeeding gate driver. The reset input may be coupled to the output of the preceding gate driver. Gate line output signals may be simultaneously asserted for each of the drivers without generating unstable scenarios where logic high signals are provided to the set and reset inputs.Type: GrantFiled: January 5, 2016Date of Patent: September 18, 2018Assignee: Apple Inc.Inventors: Abbas Jamshidi Roudbari, Keitaro Yamashita
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Patent number: 10048788Abstract: Improvement of visual uniformity of an integrated touch screen display is provided. A touch screen can include common electrodes separated by gaps in a Vcom layer. To improve visual non-uniformity in the display resulting from the gaps, a first set of semi-transparent dummy features (primary-dummy features) can be formed on a second layer at the locations of the gaps, and a second set of dummy features (supplementary-dummy features) can also be formed on the second layer or another layer to mitigate low spatial resolution of the primary-dummy features and/or non-uniform spacing of the primary-dummy features. In some examples, holes or slits can be formed in the Vcom layer at areas of the supplementary-dummy features to further improve visual uniformity.Type: GrantFiled: March 9, 2016Date of Patent: August 14, 2018Assignee: Apple Inc.Inventors: Yu Cheng Chen, Abbas Jamshidi-Roudbari, Hiroshi Osawa, Shang-Chih Lin, Shih-Chang Chang, Shin-Hung Yeh, Ting-Kuo Chang, Majid Gharghi, Keitaro Yamashita
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Patent number: 10042409Abstract: Methods and devices useful in discharging an aberrant charge on a touch sensitive display of an electronic device are provided. By way of example, a an electronic device includes a power management and control circuitry configured to receive a first voltage signal and a second voltage signal from a display subsystem of a display of the electronic device, receive a third voltage signal from a touch subsystem of the display, provide a power signal to the display subsystem to activate the display subsystem when the display is determined to be in a temporarily inactive state. Providing the power signal to the display subsystem comprises discharging an aberrant charge based on the third voltage signal.Type: GrantFiled: December 31, 2015Date of Patent: August 7, 2018Assignee: Apple Inc.Inventors: Keitaro Yamashita, Majid Gharghi, Ting-Kuo Chang, Abbas Jamshidi Roudbari
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Publication number: 20180075808Abstract: An electronic device may include a display such as a light-emitting diode display. The electronic device may be a head-mounted device that provides a virtual reality or augmented reality environment to a user. To reduce artifacts in the display, a display may be operable in both a normal scanning mode and a partial scanning mode. In the normal scanning mode, every row of the display may be enabled to emit light in each frame. In the partial scanning mode, only a subset of the rows of the display may be enabled to emit light in each frame. The display may have a higher refresh rate in the partial scanning mode than in the normal scanning mode. To ensure uniform transistor stress across the display, the scanning driver for the display may scan the disabled rows in the partial scanning mode even though the rows will not be used to emit light.Type: ApplicationFiled: December 19, 2016Publication date: March 15, 2018Inventors: Keitaro Yamashita, Abbas Jamshidi Roudbari, Shin-Hung Yeh, Tsung-Ting Tsai, Shih-Chang Chang, Ting-Kuo Chang, Ki Yeol Byun, Warren S. Rieutort-Louis
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Publication number: 20180075809Abstract: An electronic device may include a display such as a light-emitting diode display. The electronic device may be a head-mounted device that provides a virtual reality or augmented reality environment to a user. To reduce artifacts in the display, a display may be operable in both a normal scanning mode and a partial scanning mode. In the normal scanning mode, every row of the display may be scanned in each frame. In the partial scanning mode, only a subset of the rows of the display may be scanned in each frame. The display may have a higher refresh rate in the partial scanning mode than in the normal scanning mode. The gate driver circuitry may include a shift register that includes a plurality of register circuits. At least one register circuit may have a first input and a second input that is different than the first input.Type: ApplicationFiled: January 10, 2017Publication date: March 15, 2018Inventors: Shih Chang Chang, Keitaro Yamashita, Shin-Hung Yeh, Ting-Kuo Chang, Abbas Jamshidi Roudbari, Chin-Wei Lin