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).

  • Patent number: 11380126
    Abstract: A display device is disclosed, which includes a display panel and a detection circuit. The display panel has pixels configured to display an image. The pixels include display and photo sensing pixels that are arranged in sensing channels. Each display and photo sensing pixel includes a display region and a photo sensing region. The display region emits light. The photo sensing region detects 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 has differential signal processing circuitries that are coupled to the photo sensing regions of the display and photo sensing pixels. Each differential signal processing circuitry performs a differential operation on the photo detection signals of adjacent two of the sensing channels to generate a difference signal that is used to construct a biometric pattern corresponding to the biometric object.
    Type: Grant
    Filed: February 4, 2021
    Date of Patent: July 5, 2022
    Assignee: HIMAX TECHNOLOGIES LIMITED
    Inventors: Zong-You Hou, Yaw-Guang Chang, Jia-Ming He, Wei-Hsien Yeh
  • Patent number: 11380128
    Abstract: An apparatus integrated with fingerprint recognition and touch detection is provided. The apparatus includes a touchpad and a controller IC. The touchpad has a touch area for recognizing a touch event and a fingerprint area for recognizing a fingerprint and the touch event. The fingerprint area includes TX lines of a first group crossing RX lines of a first group. The touch area includes TX lines of the first group and a second group crossing RX lines of the first group and a second group. When the apparatus is operated in a fingerprint sensing mode, the controller IC supplies a driving signal to the TX lines of the first group. When the apparatus is operated in a touch sensing mode, the controller IC supplies the driving signal to the TX lines of the second group and a portion of the TX lines of the first group.
    Type: Grant
    Filed: June 21, 2020
    Date of Patent: July 5, 2022
    Assignee: Himax Technologies Limited
    Inventors: Yaw-Guang Chang, Jia-Ming He
  • Patent number: 11334187
    Abstract: A display and touch driver system including a plurality of display and touch drivers and a wire circuit is provided. The plurality of display and touch drivers are connected in cascade. The plurality of display and touch drivers are configured to synchronously drive a display and touch panel to perform a touch sensing operation. Each of the display and touch drivers includes an operational amplifier. The operational amplifier includes a first stage and a second stage. An output node of the first stage is coupled to an input node of the second stage. The output nodes of the first stages of the operational amplifiers are connected together via the wire circuit.
    Type: Grant
    Filed: March 30, 2021
    Date of Patent: May 17, 2022
    Assignee: HIMAX TECHNOLOGIES LIMITED
    Inventors: Yi Chen Tzung, Yaw-Guang Chang
  • Patent number: 11327604
    Abstract: A touch sensing circuit for use in a touch sensitive device includes: an integrator, a first switching unit and a control signal generator. The integrator, coupled to at least one sensing electrode of a touch panel in the touch sensitive device, and arranged to collect charges on the at least one sensing electrode and accordingly generate an output sensed signal. The first switching unit is arranged to selectively couple a first end of the at least one sensing electrode to a reference voltage level according to a first mask signal. The control signal generator is arranged to generate the first mask signal according to a synchronization signal of a display panel in the touch sensitive device, wherein the first switching unit couples the first end of the at least one sensing electrode to the reference voltage level when the synchronization signal is asserted.
    Type: Grant
    Filed: September 7, 2020
    Date of Patent: May 10, 2022
    Assignee: HIMAX TECHNOLOGIES LIMITED
    Inventors: Jia-Ming He, Yaw-Guang Chang, Yu-Chun Lin, Yi-Yang Tsai
  • Patent number: 11294500
    Abstract: A touch panel for sensing a fingerprint/touch input and a display device using the same are provided. The display device includes a display panel and the touch panel. The touch panel includes drive line groups and sense line groups. Each of the drive line groups includes a drive line. Each of the sense line groups includes sense lines. A distance between adjacent two of the drive/sense line groups in a fingerprint recognition area is smaller than that between adjacent two of the drive/sense line groups in a portion of a touch control area other than the fingerprint recognition area. A distance between adjacent two of the sense lines in the fingerprint recognition area is designed to be equal a sub-pixel width, and a distance between adjacent two of the drive lines in the fingerprint recognition area is designed to be equal a sub-pixel length.
    Type: Grant
    Filed: September 1, 2020
    Date of Patent: April 5, 2022
    Assignee: HIMAX TECHNOLOGIES LIMITED
    Inventors: Jia-Ming He, Yaw-Guang Chang
  • Publication number: 20220100301
    Abstract: 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: Application
    Filed: September 29, 2020
    Publication date: March 31, 2022
    Inventors: Jia-Ming HE, Yaw-Guang CHANG
  • Patent number: 11282475
    Abstract: An electronic device control method applied to an electronic device can operate in a display mode and a touch sensing mode. The method comprises: (a) controlling the electronic device to have a first mode switch frequency; and (b) controlling the electronic device to have a second mode switch frequency different from the first mode switch frequency. The first mode switch frequency and the second mode switch frequency are frequencies for switching between the display mode and the touch sensing mode.
    Type: Grant
    Filed: July 23, 2019
    Date of Patent: March 22, 2022
    Assignee: HIMAX TECHNOLOGIES LIMITED
    Inventors: Chih-Ming Wu, Yaw-Guang Chang, Chin-Jung Chen, Yu-Feng Lin, Chung-Wen Chang
  • Publication number: 20220075499
    Abstract: A touch sensing circuit for use in a touch sensitive device includes: an integrator, a first switching unit and a control signal generator. The integrator, coupled to at least one sensing electrode of a touch panel in the touch sensitive device, and arranged to collect charges on the at least one sensing electrode and accordingly generate an output sensed signal. The first switching unit is arranged to selectively couple a first end of the at least one sensing electrode to a reference voltage level according to a first mask signal. The control signal generator is arranged to generate the first mask signal according to a synchronization signal of a display panel in the touch sensitive device, wherein the first switching unit couples the first end of the at least one sensing electrode to the reference voltage level when the synchronization signal is asserted.
    Type: Application
    Filed: September 7, 2020
    Publication date: March 10, 2022
    Inventors: Jia-Ming He, Yaw-Guang Chang, Yu-Chun Lin, Yi-Yang Tsai
  • Publication number: 20220066611
    Abstract: A touch panel for sensing a fingerprint and a touch input and a display device using the same are provided. The display device includes a display panel and the touch panel. The touch panel includes drive line groups and sense line groups. Each of the drive line groups includes a drive line, and each of the sense line groups includes plural sense lines. A distance between adjacent two of the drive/sense line groups in a fingerprint recognition area is smaller than a distance between adjacent two of the drive/sense line groups in a portion of a touch control area other than the fingerprint recognition area. A distance between adjacent two of the sense lines in the fingerprint recognition area is designed to be equal a sub-pixel width, and a distance between adjacent two of the drive lines in the fingerprint recognition area is designed to be equal a sub-pixel length.
    Type: Application
    Filed: September 1, 2020
    Publication date: March 3, 2022
    Inventors: Jia-Ming HE, Yaw-Guang CHANG
  • Patent number: 11222933
    Abstract: A display panel equipped with function of detecting an object and an associated method are provided. The display panel includes a first photosensitive circuit, a second photosensitive circuit, a detection circuit, a first switch and a second switch. The first photosensitive circuit and the second photosensitive circuit accumulate first charges and second charges in response to first incident light and second incident light to generate a first signal and a second signal, respectively, wherein the object reflects light emitted from the display panel to generate the second incident light. The detection circuit discharges the first charges for converting the first signal into a reference signal on a first input terminal of the detection circuit, and the second signal is transmitted to a second input terminal of the detection circuit, to make the detection circuit to generate a detection signal indicating a difference between the second signal and the reference signal.
    Type: Grant
    Filed: April 28, 2020
    Date of Patent: January 11, 2022
    Assignee: HIMAX TECHNOLOGIES LIMITED
    Inventors: Yaw-Guang Chang, Jia-Ming He
  • Publication number: 20210335897
    Abstract: A display panel equipped with function of detecting an object and an associated method are provided. The display panel includes a first photosensitive circuit, a second photosensitive circuit, a detection circuit, a first switch and a second switch. The first photosensitive circuit and the second photosensitive circuit accumulate first charges and second charges in response to first incident light and second incident light to generate a first signal and a second signal, respectively, wherein the object reflects light emitted from the display panel to generate the second incident light. The detection circuit discharges the first charges for converting the first signal into a reference signal on a first input terminal of the detection circuit, and the second signal is transmitted to a second input terminal of the detection circuit, to make the detection circuit to generate a detection signal indicating a difference between the second signal and the reference signal.
    Type: Application
    Filed: April 28, 2020
    Publication date: October 28, 2021
    Inventors: Yaw-Guang Chang, Jia-Ming He
  • Publication number: 20210318782
    Abstract: An apparatus integrated with fingerprint recognition and touch detection is provided. The apparatus includes a touchpad and a controller IC. The touchpad has a touch area for recognizing a touch event and a fingerprint area for recognizing a fingerprint and the touch event. The fingerprint area includes TX lines of a first group crossing RX lines of a first group. The touch area includes TX lines of the first group and a second group crossing RX lines of the first group and a second group. When the apparatus is operated in a fingerprint sensing mode, the controller IC supplies a driving signal to the TX lines of the first group. When the apparatus is operated in a touch sensing mode, the controller IC supplies the driving signal to the TX lines of the second group and a portion of the TX lines of the first group.
    Type: Application
    Filed: August 3, 2020
    Publication date: October 14, 2021
    Inventors: Jia-Ming HE, Yaw-Guang CHANG
  • Patent number: 11137853
    Abstract: The present invention provides a touch panel and a controlling method thereof. The controlling method comprises: during a display period of the touch panel, turning on a bias voltage generation circuit to generate a bias voltage signal, turning on a reverse bias voltage generation circuit to generate a reverse bias voltage signal, and turning off a modulating voltage generation circuit; during a touch period of the touch panel, turning off the bias voltage generation circuit, the reverse bias voltage generation circuit and turning on the modulating voltage generation circuit to generate a modulating voltage signal, wherein the modulating voltage signal is same as a touch sensing signal of the touch panel; using a first capacitor to couple the modulating voltage signal to the bias voltage generation circuit; and using a second capacitor to couple the modulating voltage signal to the reverse bias voltage generation circuit.
    Type: Grant
    Filed: August 10, 2020
    Date of Patent: October 5, 2021
    Assignee: HIMAX TECHNOLOGIES LIMITED
    Inventors: Yaw-Guang Chang, Wei-Song Wang
  • Publication number: 20210271850
    Abstract: An apparatus integrated with fingerprint recognition and touch detection is provided. The apparatus includes a touchpad and a controller IC. The touchpad has a touch area for recognizing a touch event and a fingerprint area for recognizing a fingerprint and the touch event. The fingerprint area includes TX lines of a first group crossing RX lines of a first group. The touch area includes TX lines of the first group and a second group crossing RX lines of the first group and a second group. When the apparatus is operated in a fingerprint sensing mode, the controller IC supplies a driving signal to the TX lines of the first group. When the apparatus is operated in a touch sensing mode, the controller IC supplies the driving signal to the TX lines of the second group and a portion of the TX lines of the first group.
    Type: Application
    Filed: June 21, 2020
    Publication date: September 2, 2021
    Inventors: Yaw-Guang Chang, Jia-Ming He
  • Patent number: 11086443
    Abstract: A touch apparatus, a touch driving device and an operation method are provided. The touch driving device includes a first routing circuit, a second routing circuit, and a processing circuit. The first routing circuit connects a first current electrode of first sensing electrodes to a first common terminal of the first routing circuit. The second routing circuit connects a second current electrode of second sensing electrodes to a second common terminal of the second routing circuit. The same input terminal of the processing circuit is coupled to the first common terminal and the second common terminal. In the case where a touch sensing result corresponding to the input terminal indicates that a touch event has occurred, the processing circuit checks whether the touch event also occurs on an adjacent sensing electrode adjacent to the first current electrode to determine whether the touch event occurs on the first current electrode.
    Type: Grant
    Filed: April 9, 2020
    Date of Patent: August 10, 2021
    Assignee: HIMAX TECHNOLOGIES LIMITED
    Inventors: Yaw-Guang Chang, En-Tse Cun
  • Publication number: 20210240288
    Abstract: 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: Application
    Filed: September 20, 2020
    Publication date: August 5, 2021
    Inventors: Yaw-Guang CHANG, Hui-Min WANG, Cheng-Hung TSAI, Chung-Wen CHANG
  • Patent number: 11061500
    Abstract: A touch display driving apparatus and an operation method thereof are provided. A display frame period is divided into a plurality of display driving periods and a plurality of touch driving periods. During the display driving periods, the display driver circuit drives a touch display panel. During the touch driving periods, the touch driver circuit detects common electrode rows of the touch display panel. The common electrode rows are parallel to a plurality of gate lines of the touch display panel. Each of the common electrode rows serves as a current common electrode row, wherein the current common electrode row covers a plurality of corresponding gate lines of the gate lines. The touch driving period during which the current common electrode row being detected is not temporally adjacent to the display driving period during which the corresponding gate lines being driven.
    Type: Grant
    Filed: September 9, 2019
    Date of Patent: July 13, 2021
    Assignee: HIMAX TECHNOLOGIES LIMITED
    Inventors: Yaw-Guang Chang, Wei-Song Wang
  • Patent number: 11055508
    Abstract: A display panel and an associated electronic device are provided. The display panel may include: a plurality of display blocks arranged to display images, a plurality of light sensors arranged to perform light sensing, a plurality of sets of switches, and a detection circuit. The plurality of sets of switches may combine the plurality of light sensors into a plurality of combined sensors, respectively, wherein the plurality of sets of switches operate according to a plurality of switching signals, respectively. The detection circuit may be coupled to two sets of combined sensors within the plurality of combined sensors, and arranged to detect a voltage level of a combined sensor of one set of the two sets of combined sensors according to a reference voltage level, for performing fingerprint detection through the display panel, wherein the reference voltage level is obtained from another set of the two sets of combined sensors.
    Type: Grant
    Filed: August 29, 2019
    Date of Patent: July 6, 2021
    Assignee: HIMAX TECHNOLOGIES LIMITED
    Inventors: Jia-Ming He, Yaw-Guang Chang, I-Lin Wu
  • Patent number: 11048904
    Abstract: A fingerprint sensor embedded in a flat-panel display includes photo sensors; select transistors that are correspondingly connected in series with the photo sensors respectively; switch transistors that are correspondingly connected in series with the select transistors respectively, but are correspondingly connected in parallel with the photo sensors respectively; and a detection circuit that detects a signal passing one turned-on select transistor.
    Type: Grant
    Filed: October 3, 2019
    Date of Patent: June 29, 2021
    Assignee: Hirnax Technologies Limited
    Inventors: I-Lin Wu, Jia-Ming He, Yaw-Guang Chang
  • Patent number: 10976857
    Abstract: A method and apparatus for driving a touch display driver integrated circuit (TDDI) of a touch-sensitive display panel are provided. The method may include: in a display phase of the touch-sensitive display panel, utilizing a reference voltage generator to generate a reference voltage having a predetermined voltage level to be a common voltage of the touch-sensitive display panel, and utilizing a common voltage operational amplifier (OPAMP) to drive the common voltage to the TDDI IC through a common voltage path, for performing display control of the touch-sensitive display panel; and in a touch-sensing phase of the touch-sensitive display panel, utilizing a touch-sensing waveform generator to generate a touch-sensing waveform signal carrying at least one touch-sensing waveform, and utilizing the common voltage OPAMP to drive the touch-sensing waveform signal to the TDDI IC through the common voltage path, for performing touch-sensing control of the touch-sensitive display panel.
    Type: Grant
    Filed: March 15, 2020
    Date of Patent: April 13, 2021
    Assignee: HIMAX TECHNOLOGIES LIMITED
    Inventors: Yaw-Guang Chang, Hui-Min Wang