Patents by Inventor Yaw-Guang Chang
Yaw-Guang 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).
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Patent number: 11977705Abstract: A touch event processing circuit includes receiving circuits and an average circuit. Each of the receiving circuits includes an operation amplifier, a current processing circuit, and a touch event detection circuit. The operation amplifier receives an input signal from a touch panel, and outputs a first current signal and a second current signal. The current processing circuit processes the first current signal and the second current signal according to a first current average signal and a second current average signal, to generate a processed current signal. The touch event detection circuit detects a touch event according to the processed current signal. The average circuit receives first current signals and second current signals from the receiving circuits; performs an average operation upon the first current signals, to generate the first current average signal; and performs an average operation upon the second current signals, to generate the second current average signal.Type: GrantFiled: November 28, 2022Date of Patent: May 7, 2024Assignee: HIMAX TECHNOLOGIES LIMITEDInventors: Jia-Ming He, Yaw-Guang Chang, Yi-Yang Tsai
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Publication number: 20240078833Abstract: The fingerprint sensing circuit includes a photo detector, a capacitor, a current mirror and a switch circuit. The capacitor has a first terminal electrically connected to the first terminal of the photo detector. The current mirror has an input terminal electrically connected to the first terminal of the photo detector and an output terminal electrically connected to a sensing line. In an exposure period, the switch circuit turns off the current mirror. In a sensing period, the switch circuit turns on the current mirror to generate a current on the sensing line, and the detecting circuit is configured to generate a fingerprint signal according to the current.Type: ApplicationFiled: September 5, 2022Publication date: March 7, 2024Inventors: Yaw-Guang CHANG, Jia-Ming HE, Zong-You HOU
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Patent number: 11886666Abstract: A detection circuit adaptable to a fingerprint detection system includes an integrating amplifier coupled to receive a photo-detected voltage from a sensor panel and configured to generate time integral of the photo-detected voltage, thereby resulting in a time-integral signal; and an analog-to-digital converter (ADC) that converts the time-integral signal into a digital form. A first common-mode voltage of the sensor panel is coupled to the integrating amplifier to prevent noise occurred in the first common-mode voltage from affecting the time-integral signal.Type: GrantFiled: December 28, 2022Date of Patent: January 30, 2024Assignee: Himax Technologies LimitedInventors: Yaw-Guang Chang, Jia-Ming He, Zong-You Hou
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Patent number: 11876513Abstract: A low power consumption boost circuit for providing high driving voltage of a touch circuit is provided. The low power consumption boost circuit includes a charge pump circuit, two digital-to-analog converters (DACs), and a switch circuit. The charge pump circuit receives a system voltage and correspondingly outputs a positive output voltage twice the system voltage and a negative output voltage with opposite polarity as the system voltage. One of the DACs receives the positive output voltage from the charge pump circuit as supply voltage, and the other DAC receives the negative output voltage from the charge pump circuit as supply voltage. The switch circuit is connected between the DACs and the touch circuit. The DACs are connected between the charge pump circuit and the switch circuit. The DACs are alternately connected to the touch circuit by controlling the switch circuit, thereby driving the touch circuit alternately.Type: GrantFiled: February 12, 2023Date of Patent: January 16, 2024Assignee: HIMAX TECHNOLOGIES LIMITEDInventors: Jia-Ming He, Yaw-Guang Chang, Zong-You Hou
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Patent number: 11874985Abstract: A driving signal processing method for a large touch display integrated (LTDI) system is provided. The LTDI system includes plural LTDI chips that are concatenated. The LTDI chips include a master LTDI chip and plural slave LTDI chips. The driving signal processing method includes: receiving, by the LTDI chips, display data from a timing controller; and dispersedly outputting, by the master LTDI chip and at least one of the slave LTDI chips, M gate control signals respectively corresponding to M gate lines of a display panel of the LTDI system according to the display data during the display stage of the display panel.Type: GrantFiled: January 19, 2023Date of Patent: January 16, 2024Assignee: HIMAX TECHNOLOGIES LIMITEDInventors: Yaw-Guang Chang, Pei Yao Chang, De Wei Shen, Yi Wen Wang
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Patent number: 11842560Abstract: The fingerprint sensing circuit includes pixel sensors with photo sensors. Sensing currents produced by first pixel sensors are averaged. The average current is subtracted from sensing current produced by second pixel sensors to generate a difference current. During a capture period, a converting circuit outputs a digital signal in response to the difference current. This circuit aims to reduce noise in fingerprint recognition technology.Type: GrantFiled: May 24, 2023Date of Patent: December 12, 2023Assignee: HIMAX TECHNOLOGIES LIMITEDInventors: Yaw-Guang Chang, Jia-Ming He, Zong-You Hou
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Publication number: 20230341972Abstract: A touch event processing circuit includes receiving circuits and an average circuit. Each of the receiving circuits includes an operation amplifier, a current processing circuit, and a touch event detection circuit. The operation amplifier receives an input signal from a touch panel, and outputs a first current signal and a second current signal. The current processing circuit processes the first current signal and the second current signal according to a first current average signal and a second current average signal, to generate a processed current signal. The touch event detection circuit detects a touch event according to the processed current signal. The average circuit receives first current signals and second current signals from the receiving circuits; performs an average operation upon the first current signals, to generate the first current average signal; and performs an average operation upon the second current signals, to generate the second current average signal.Type: ApplicationFiled: November 28, 2022Publication date: October 26, 2023Applicant: HIMAX TECHNOLOGIES LIMITEDInventors: Jia-Ming He, Yaw-Guang Chang, Yi-Yang Tsai
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Patent number: 11734944Abstract: A display device includes an active matrix substrate and a detection circuit. The active matrix substrate has pixels that are configured to display an image. The pixels include display and photo sensing pixels each including a display region and a photo sensing region. The display region is configured to emit light with a predetermined emitting frequency in a blank period of the display device. The photo sensing region is adjacent to the display region, and is configured to detect the light emitted by the display region and reflected from a biometric object and to convert the reflected light into photo detection signals. The detection circuit is coupled to the photo sensing circuit of each of the display and photo sensing pixels, and is configured to construct a biometric pattern corresponding to the biometric object based on the photo detection signals.Type: GrantFiled: December 26, 2017Date of Patent: August 22, 2023Assignee: HIMAX TECHNOLOGIES LIMITEDInventors: Jia-Ming He, Yaw-Guang Chang
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Publication number: 20230236690Abstract: A driving signal processing method for a large touch display integrated (LTDI) system is provided. The LTDI system includes plural LTDI chips that are concatenated. The LTDI chips include a master LTDI chip and plural slave LTDI chips. The driving signal processing method includes: receiving, by the LTDI chips, display data from a timing controller; and dispersedly outputting, by the master LTDI chip and at least one of the slave LTDI chips, M gate control signals respectively corresponding to M gate lines of a display panel of the LTDI system according to the display data during the display stage of the display panel.Type: ApplicationFiled: January 19, 2023Publication date: July 27, 2023Inventors: Yaw-Guang CHANG, Pei Yao CHANG, De Wei SHEN, Yi Wen WANG
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Publication number: 20230225051Abstract: A pad configuration adaptable to a display system includes a plurality of input bond pads, via which a driver of the display system is mounted and signals are inputted to the driver; and a plurality of output bond pads, via which the driver is mounted and signals are outputted to a display panel of the display system. Input and output bond pads corresponding to one of two neighboring drivers are point symmetric with input and output bond pads corresponding to the other of the two neighboring drivers.Type: ApplicationFiled: January 11, 2022Publication date: July 13, 2023Inventors: Hui-Min Wang, Yaw-Guang Chang
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Patent number: 11620023Abstract: A touch event processing circuit includes a plurality of receiving circuits and an average circuit. Each of the plurality of receiving circuits includes a first integrator circuit, a resistor, and a touch event detection circuit. The first integrator circuit is arranged to receive an input signal that includes a voltage sensing signal from a touch panel, and output a first integrated voltage signal. The resistor has a first terminal coupled to an output terminal of the first integrator circuit and a second terminal. The touch event detection circuit is arranged to detect a touch event according to the output from the second terminal of the resistor and a voltage average signal. The average circuit is arranged to: receive a plurality of first integrated voltage signals from the plurality of receiving circuits; and perform an average operation upon the plurality of first integrated voltage signals, to generate the voltage average signal.Type: GrantFiled: April 25, 2022Date of Patent: April 4, 2023Assignee: HIMAX TECHNOLOGIES LIMITEDInventors: Jia-Ming He, Yaw-Guang Chang, Yi-Yang Tsai
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Patent number: 11620017Abstract: A touch controller coupled to a touch sensor panel and arranged to detect touch events on the touch sensor panel includes a sensing circuit. The sensing circuit includes an integrator circuit and a reference voltage controlling circuit. The integrator circuit includes a first input node coupled to a sensing node for receiving a sensing signal, a second input node coupled to a guard trace disposed adjacent to the touch sensor panel and an output node outputting an integrated signal. The reference voltage controlling circuit includes a switch coupled between the second input node of the integrator circuit and a voltage source providing a reference voltage. The switch is closed during a pre-charge period to charge a voltage on the guard trace to the reference voltage in beginning of a sensing period and is opened after the pre-charge period.Type: GrantFiled: May 20, 2021Date of Patent: April 4, 2023Assignee: HIMAX TECHNOLOGIES LIMITEDInventors: Jia-Ming He, Yaw-Guang Chang, Yi-Yang Tsai
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Publication number: 20230084350Abstract: Circuit for performing a display driving function and a fingerprint and touch detecting function includes a unity gain buffer amplifier, an operational amplifier integrator, an ADC circuit, and a digital processing circuit coupled to the ADC circuit. An input terminal of the operational amplifier integrator is coupled to a touch sensor. When the circuit is operated under a display driving mode, an input terminal of the unity gain buffer amplifier receives a gray level voltage and an output terminal of the unity gain buffer amplifier is coupled to a display panel. When the circuit is operated under a fingerprint detecting mode, the input terminal and the output terminal of the unity gain buffer amplifier are respectively coupled to a fingerprint sensor and the ADC circuit. When the circuit is operated under a touch detecting mode, an output terminal of the operational amplifier integrator is coupled to the ADC circuit.Type: ApplicationFiled: October 31, 2022Publication date: March 16, 2023Inventors: Jia-Ming HE, Yaw-Guang CHANG
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Publication number: 20230083561Abstract: Circuit for performing a display driving function and a fingerprint and touch detecting function includes a unity gain buffer amplifier, an operational amplifier integrator, an ADC circuit, and a digital processing circuit coupled to the ADC circuit. An input terminal of the operational amplifier integrator is coupled to a touch sensor. When the circuit is operated under a display driving mode, an input terminal of the unity gain buffer amplifier receives a gray level voltage and an output terminal of the unity gain buffer amplifier is coupled to a display panel. When the circuit is operated under a fingerprint detecting mode, the input terminal and the output terminal of the unity gain buffer amplifier are respectively coupled to a fingerprint sensor and the ADC circuit. When the circuit is operated under a touch detecting mode, an output terminal of the operational amplifier integrator is coupled to the ADC circuit.Type: ApplicationFiled: October 31, 2022Publication date: March 16, 2023Inventors: Jia-Ming HE, Yaw-Guang CHANG
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Patent number: 11543916Abstract: A driver circuit configured to drive a display panel to perform a display operation and a touch sensing operation is provided. The driver circuit includes a touch and display driver integration (TDDI) circuit and an external circuit. The TDDI circuit is configured to drive the display panel to perform the display operation and the touch sensing operation during a display period and a touch sensing period, respectively. The TDDI circuit outputs a reference signal. The external circuit is disposed outside of the TDDI circuit. The external circuit is configured to output a first output voltage and a second output voltage on the basis of the reference signal from the TDDI circuit. The first output voltage is larger than the second output voltage.Type: GrantFiled: December 22, 2021Date of Patent: January 3, 2023Assignee: HIMAX TECHNOLOGIES LIMITEDInventors: Pei Yao Chang, Yaw-Guang Chang
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Patent number: 11520424Abstract: A circuit for performing a display driving function and a fingerprint and touch detecting function includes a unity gain buffer amplifier, an operational amplifier integrator, an ADC circuit, and a digital processing circuit coupled to the ADC circuit. An input terminal of the operational amplifier integrator is coupled to a touch sensor. When the circuit is operated under a display driving mode, an input terminal of the unity gain buffer amplifier receives a gray level voltage and an output terminal of the unity gain buffer amplifier is coupled to a display panel. When the circuit is operated under a fingerprint detecting mode, the input terminal and the output terminal of the unity gain buffer amplifier are respectively coupled to a fingerprint sensor and the ADC circuit. When the circuit is operated under a touch detecting mode, an output terminal of the operational amplifier integrator is coupled to the ADC circuit.Type: GrantFiled: September 29, 2020Date of Patent: December 6, 2022Assignee: HIMAX TECHNOLOGIES LIMITEDInventors: Jia-Ming He, Yaw-Guang Chang
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Publication number: 20220374100Abstract: A touch controller coupled to a touch sensor panel and arranged to detect touch events on the touch sensor panel includes a sensing circuit. The sensing circuit includes an integrator circuit and a reference voltage controlling circuit. The integrator circuit includes a first input node coupled to a sensing node for receiving a sensing signal, a second input node coupled to a guard trace disposed adjacent to the touch sensor panel and an output node outputting an integrated signal. The reference voltage controlling circuit includes a switch coupled between the second input node of the integrator circuit and a voltage source providing a reference voltage. The switch is closed during a pre-charge period to charge a voltage on the guard trace to the reference voltage in beginning of a sensing period and is opened after the pre-charge period.Type: ApplicationFiled: May 20, 2021Publication date: November 24, 2022Inventors: Jia-Ming He, Yaw-Guang Chang, Yi-Yang Tsai
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Patent number: 11494038Abstract: A touch panel includes a cover lens located at top of the touch panel, plural touch sensor units, and plural sensing channels. The touch sensor units are disposed below the cover lens and arranged in rows and columns. The touch sensor units are disposed on the sensing channels. Each of touch sensor units acquires a sensing magnitude for identifying a position of the cover lens that touched by the stylus according to signals outputted by the sensing channels. The sensing magnitude of one of the touch sensor units is composed of the signals of the adjacent sensing channels located within a vertical projection of the one of the touch sensor units.Type: GrantFiled: September 20, 2020Date of Patent: November 8, 2022Assignee: HIMAX TECHNOLOGIES LIMITEDInventors: Yaw-Guang Chang, Hui-Min Wang, Cheng-Hung Tsai, Chung-Wen Chang
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Patent number: 11449172Abstract: The invention provides a touch control apparatus and a touch panel thereof. The touch panel includes a plurality of pads and a plurality of sensing electrodes. The pads are suitable for being electrically connected to different pins of a touch driving device. The sensing electrodes are suitable for sensing a touch event of the touch panel. Any column of the sensing electrodes includes a plurality of sensing electrode groups. A plurality of sensing electrodes belonging to any one of the sensing electrode groups among the sensing electrodes are coupled to a corresponding one of the pads. The sensing electrodes in each of sensing electrode groups in a same column are dispersedly arranged in the same column. The arrangement of the sensing electrode groups in any column of the sensing electrodes is different from the arrangement of the sensing electrode groups in an adjacent column adjacent to the any column.Type: GrantFiled: October 18, 2021Date of Patent: September 20, 2022Assignee: HIMAX TECHNOLOGIES LIMITEDInventor: Yaw-Guang Chang
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Publication number: 20220261134Abstract: A driver circuit configured to drive a display panel to perform a display operation and a touch sensing operation is provided. The driver circuit includes a touch and display driver integration (TDDI) circuit and an external circuit. The TDDI circuit is configured to drive the display panel to perform the display operation and the touch sensing operation during a display period and a touch sensing period, respectively. The TDDI circuit outputs a reference signal. The external circuit is disposed outside of the TDDI circuit. The external circuit is configured to output a first output voltage and a second output voltage on the basis of the reference signal from the TDDI circuit. The first output voltage is larger than the second output voltage.Type: ApplicationFiled: December 22, 2021Publication date: August 18, 2022Applicant: HIMAX TECHNOLOGIES LIMITEDInventors: Pei Yao Chang, Yaw-Guang Chang