Patents by Inventor Bobiao Chang

Bobiao Chang 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).

  • Patent number: 11462184
    Abstract: A driving method, a driving device and a liquid crystal display device are provided. The driving device of the LCD display device outputs the target grey value of the nth frame according to the original grey value of the nth frame, the original grey value of the (n?1)th frame and the look-up table. This improves the luminance of the sub-pixel of the nth frame, shortens the required charging time of the sub-pixel when the (n+1)th frame is being displayed. Thus, the sub-pixel of the (n+1)th frame could be efficiently charged and the luminance of the sub-pixel could be increased. In addition, since the luminance increase of the (n+1)th frame is more than that of the nth frame, the contrast of the LCD display could be improved.
    Type: Grant
    Filed: January 10, 2020
    Date of Patent: October 4, 2022
    Inventors: Bobiao Chang, Yichien Wen
  • Publication number: 20210407443
    Abstract: A driving method, a driving device and a liquid crystal display device are provided. The driving device of the LCD display device outputs the target grey value of the nth frame according to the original grey value of the nth frame, the original grey value of the (n?1)th frame and the look-up table. This improves the luminance of the sub-pixel of the nth frame, shortens the required charging time of the sub-pixel when the (n+1)th frame is being displayed. Thus, the sub-pixel of the (n+1)th frame could be efficiently charged and the luminance of the sub-pixel could be increased. In addition, since the luminance increase of the (n+1)th frame is more than that of the nth frame, the contrast of the LCD display could be improved.
    Type: Application
    Filed: January 10, 2020
    Publication date: December 30, 2021
    Applicant: TCL CHINA STAR OPTOELECTRONICS TECHNOLOGY CO., LTD.
    Inventors: Bobiao CHANG, Yichien WEN
  • Patent number: 11176884
    Abstract: OLED pixel driving circuit, array substrate and display device are provided. The pixel driving circuit comprises a driving control unit, a first light emitting unit and a second light emitting unit. Two OLEDs share one driving control unit, so the two OLEDs alternately emit light. In this way, light emitting time of the OLEDs is reduced, number of parasitic capacitors and data lines in a panel is reduced, and aperture ratio of the OLED device is increased; and OLEDs are enabled to be in reverse bias in a non-light emitting display frame, so that OLEDs do not have to be in a DC bias state for a long time, and thus, aging of the OLED device is slowed down. No other reverse bias voltage is connected externally, difficulty of tracing of the pixel circuit and crosstalk from a bias voltage line to other signal lines are reduced.
    Type: Grant
    Filed: November 23, 2017
    Date of Patent: November 16, 2021
    Assignee: Shenzhen Chins Star Optoelectronics Semiconductor Display Technology Co., Ltd.
    Inventors: Bobiao Chang, Xiaolong Chen, Yi-chien Wen
  • Patent number: 11074857
    Abstract: The present invention teaches a DC boost circuit and method. The circuit includes an inductor, a diode, a first capacitor, a first FET, a first voltage conversion unit, a voltage drop detection module, a reference voltage adjustment module, and a control module. After a load is connected, the voltage drop detection module obtains a current flowing through the diode and outputs a corresponding second voltage to the reference voltage adjustment module, causing an output voltage from the reference voltage adjustment module greater than an original reference voltage. The control module controls the first FET to increase a ratio of its conduction interval to its cutoff interval in a cycle of conduction and cutoff, thereby increasing the output voltage to compensate the voltage drop resulted from the impedance between the DC boost circuit and the load. The output voltage is therefore ensured to have a stable level.
    Type: Grant
    Filed: September 18, 2018
    Date of Patent: July 27, 2021
    Assignee: SHENZHEN CHINA STAR OPTOELECTRONICS SEMICONDUCTOR DISPLAY TECHNOLOGY CO., LTD.
    Inventor: Bobiao Chang
  • Publication number: 20210110768
    Abstract: The present invention teaches a DC boost circuit and method. The circuit includes an inductor, a diode, a first capacitor, a first FET, a first voltage conversion unit, a voltage drop detection module, a reference voltage adjustment module, and a control module. After a load is connected, the voltage drop detection module obtains a current flowing through the diode and outputs a corresponding second voltage to the reference voltage adjustment module, causing an output voltage from the reference voltage adjustment module greater than an original reference voltage. The control module controls the first FET to increase a ratio of its conduction interval to its cutoff interval in a cycle of conduction and cutoff, thereby increasing the output voltage to compensate the voltage drop resulted from the impedance between the DC boost circuit and the load. The output voltage is therefore ensured to have a stable level.
    Type: Application
    Filed: September 18, 2018
    Publication date: April 15, 2021
    Inventor: Bobiao Chang
  • Patent number: 10978010
    Abstract: The present invention provides a line over driving (LOD) table adjustment method and a system thereof, which divides a display panel into M*N blocks. In an i-th row and a j-th column in the LOD table corresponding to a block, according to a brightness value of a grayscale value of a pixel of a previous line and a current line corresponding to an initial grayscale value of over driving pixels, calculate a target brightness value of an adjustment screen corresponding to a combination of the grayscale value of the pixel of the previous line and the current line corresponding to the initial grayscale value of over driving pixels, and obtain a measured brightness value of the adjustment screen to compare whether the difference between the target brightness value and the measured brightness value is within the default error range value to determine a final grayscale value of over driving pixel.
    Type: Grant
    Filed: August 9, 2019
    Date of Patent: April 13, 2021
    Assignee: TCL China Star Optoelectronics Technolog Co., Ltd.
    Inventors: Bobiao Chang, Yichien Wen
  • Publication number: 20210082347
    Abstract: Provided are a pixel driving circuit of an AMOLED device and a pixel driving method of an AMOLED device. The pixel driving circuit comprises: sub pixel circuits, scan lines, data lines and control lines. Each sub pixel circuit comprises a first TFT, a second TFT, a third TFT, a capacitor and an OLED. In a blank display stage of each frame of the AMOLED device, the plurality of rows of control lines respectively input corresponding control signals to control the third TFTs in at least one row of sub pixel circuits to be turned on, and the plurality of columns of data lines inputs bias voltages, wherein the bias voltages are smaller than the power source negative voltage so that an anode voltage of OLED in the sub pixel circuit, in which the third TFT is turned on, is smaller than a cathode voltage to achieve reverse bias.
    Type: Application
    Filed: September 7, 2018
    Publication date: March 18, 2021
    Inventors: Bobiao CHANG, Yichien WEN
  • Publication number: 20210035513
    Abstract: The present invention provides a line over driving (LOD) table adjustment method and a system thereof, which divides a display panel into M*N blocks. In an i-th row and a j-th column in the LOD table corresponding to a block, according to a brightness value of a grayscale value of a pixel of a previous line and a current line corresponding to an initial grayscale value of over driving pixels, calculate a target brightness value of an adjustment screen corresponding to a combination of the grayscale value of the pixel of the previous line and the current line corresponding to the initial grayscale value of over driving pixels, and obtain a measured brightness value of the adjustment screen to compare whether the difference between the target brightness value and the measured brightness value is within the default error range value to determine a final grayscale value of over driving pixel.
    Type: Application
    Filed: August 9, 2019
    Publication date: February 4, 2021
    Inventors: Bobiao CHANG, Yichien Wen
  • Publication number: 20200380928
    Abstract: A pixel driving circuit and a pixel driving circuit method are provided. The pixel driving circuit includes sub-pixels arranged in an array, scanning lines extended in a horizontal direction, and data lines extended in a vertical direction. Each of the scanning lines is connected to a row of the sub-pixels, and a column of the sub-pixels is alternately connected to the data lines adjacent to the column of the sub-pixels. Odd-numbered scanning lines are configured to transmit a scanning signal to an odd-numbered row of the sub-pixels in an odd-numbered frame of display, and even-numbered scanning lines are configured to transmit a scanning signal to an even-numbered row of the sub-pixels in an even-numbered frame of display, and the data lines are configured to transmit a voltage signal to the sub-pixels, and a polarity of the signal is changed every two frames of display.
    Type: Application
    Filed: June 25, 2019
    Publication date: December 3, 2020
    Inventors: Bobiao CHANG, Yichien Wen
  • Publication number: 20200258447
    Abstract: OLED pixel driving circuit, array substrate and display device are provided. The pixel driving circuit comprises a driving control unit, a first light emitting unit and a second light emitting unit. Two OLEDs share one driving control unit, so the two OLEDs alternately emit light. In this way, light emitting time of the OLEDs is reduced, number of parasitic capacitors and data lines in a panel is reduced, and aperture ratio of the OLED device is increased; and OLEDs are enabled to be in reverse bias in a non-light emitting display frame, so that OLEDs do not have to be in a DC bias state for a long time, and thus, aging of the OLED device is slowed down. No other reverse bias voltage is connected externally, difficulty of tracing of the pixel circuit and crosstalk from a bias voltage line to other signal lines are reduced.
    Type: Application
    Filed: November 23, 2017
    Publication date: August 13, 2020
    Inventors: Bobiao CHANG, Xiaolong CHEN, Yi-chien WEN
  • Patent number: 10467953
    Abstract: The present disclosure relates to a pixel driving circuit and an organic light-emitting diode (OLED) display having the pixel driving circuit. The pixel driving circuit adopts a 6T2C (six transistors and two capacitors) structure to compensate a threshold voltage of the driving thin film transistor (TFT) in the pixel. As such, a current passing through the OLED may not be related to the threshold voltage of the driving TFT. So as to eliminate the improper image-displaying of the OLED display resulting from the drifting of the threshold voltage of the driving TFT.
    Type: Grant
    Filed: December 13, 2017
    Date of Patent: November 5, 2019
    Assignee: Shenzhen China Star Optoelectronics Semiconductor Display Technology Co., Ltd
    Inventors: Bobiao Chang, Xiaolong Chen, Yi-chien Wen, Ming-jong Jou
  • Patent number: 10366654
    Abstract: The present disclosure provides an OLED pixel circuit and a method for retarding the aging of an OLED device. By providing a first sub-pixel driving unit, a second sub-pixel driving unit, a first reverse biasing unit, and a second reverse biasing unit and by simple control timing, a first light emitting diode and a second light emitting diode will not always be in a DC biased state, and the first light emitting diode and the second light emitting diode will emit light alternately in different frames.
    Type: Grant
    Filed: October 26, 2017
    Date of Patent: July 30, 2019
    Assignee: Shenzhen China Star Optoelectronics Semiconductor Display Technology Co., Ltd.
    Inventors: Bobiao Chang, Xiaolong Chen, Yi-chien Wen
  • Patent number: 10331150
    Abstract: A power supply device and current equalization method wherein the device includes: a plurality of power modules connected in parallel and a plurality of current equalization modules; two adjacent power modules corresponding to a current equalization module, each power module including: voltage output unit, power stage unit, and control unit; each current equalization module including: first and second current sampling conversion units, and error comparison unit; by using the error comparison unit to compare difference between load currents of two adjacent power modules and generating corresponding first control voltage based on the load currents, and the control unit generating the second control voltage based on the first control voltage to control the power stage unit to change the output voltage according to the second control voltage changing. The device accurately achieves current equalization of power modules connected in parallel and simplifies complexity of power supply device.
    Type: Grant
    Filed: December 14, 2017
    Date of Patent: June 25, 2019
    Assignee: SHENZHEN CHINA STAR OPTOELECTRONICS SEMICONDUCTOR DISPLAY TECHNOLOGY CO., LTD.
    Inventor: Bobiao Chang
  • Publication number: 20190121377
    Abstract: The invention provides a power supply device and current equalization method thereof. The device comprises: a plurality of power modules connected in parallel and a plurality of current equalization modules; two adjacent power modules corresponding to a current equalization module, each power module comprising: voltage output unit, power stage unit, and control unit; each current equalization module comprising: first and second current sampling conversion units, and error comparison unit; by using the error comparison unit to compare difference between load currents of two adjacent power modules and generating corresponding first control voltage based on the load currents, and the control unit generating the second control voltage based on the first control voltage to control the power stage unit to change the output voltage according to the second control voltage changing.
    Type: Application
    Filed: December 14, 2017
    Publication date: April 25, 2019
    Inventor: Bobiao Chang
  • Publication number: 20190103054
    Abstract: The present disclosure relates to a pixel driving circuit and an organic light-emitting diode (OLED) display having the pixel driving circuit. The pixel driving circuit adopts a 6T2C (six transistors and two capacitors) structure to compensate a threshold voltage of the driving thin film transistor (TFT) in the pixel. As such, a current passing through the OLED may not be related to the threshold voltage of the driving TFT. So as to eliminate the improper image-displaying of the OLED display resulting from the drifting of the threshold voltage of the driving TFT.
    Type: Application
    Filed: December 13, 2017
    Publication date: April 4, 2019
    Applicant: Shenzhen China Star Optoelectronics Semiconductor Display Technology Co., Ltd.
    Inventors: Bobiao CHANG, Xiaolong CHEN, Yi-chien WEN, Ming-jong JOU
  • Publication number: 20190066583
    Abstract: The present disclosure provides an OLED pixel circuit and a method for retarding the aging of an OLED device. By providing a first sub-pixel driving unit, a second sub-pixel driving unit, a first reverse biasing unit, and a second reverse biasing unit and by simple control timing, a first light emitting diode and a second light emitting diode will not always be in a DC biased state, and the first light emitting diode and the second light emitting diode will emit light alternately in different frames.
    Type: Application
    Filed: October 26, 2017
    Publication date: February 28, 2019
    Inventors: Bobiao CHANG, Xiaolong CHEN, Yi-Chien WEN
  • Publication number: 20190019457
    Abstract: A display device includes: a plurality of pixels each including an organic light emitting diode, a power voltage supply supplying a power positive voltage and a power negative voltage to the plurality of pixels, a voltage detector generating a compensation signal when detecting that the power positive voltage and a standard power positive voltage are different, a timing controller compensating a scan control signal and a data control signal based on the compensation signal, a scan driver generating a compensated scan voltage based on a compensated scan control signal and supplying the compensated scan voltage to the plurality of pixels and a data driver generating a compensated data voltage based on a compensated data control signal and supplying the compensated data voltage to the plurality of pixels, wherein the compensated scan voltage and the compensated data voltage allow a driving current of the organic light emitting diode to be constant.
    Type: Application
    Filed: October 18, 2017
    Publication date: January 17, 2019
    Inventors: Bobiao Chang, Shu Wen, Yi-chien Wen, Ming-jong Jou