Patents by Inventor Wen-Hua Chang
Wen-Hua 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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Publication number: 20160098139Abstract: A touch system, a stylus, a touch apparatus, and a control method of the touch apparatus are provided. The control method includes following steps. At least one characteristic data of at least one input tool is obtained. An identifier of the input tool is generated according to the characteristic data. If a touch operation on the touch panel is performed with the input tool, a specific function of the touch apparatus is determined according to the identifier of the input tool.Type: ApplicationFiled: July 23, 2015Publication date: April 7, 2016Inventors: Yao-Tsung Chang, Ching-Fu Hsu, Ming-Chih Chen, Kuo-Hsing Wang, Jui-Ta Hsieh, Chih-Chung Chiang, Wen-Hua Chang
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Publication number: 20160087632Abstract: A current amplifier and a transmitter using the same. The current amplifier has a first and second transistor and a voltage level shifting unit. The first transistor has a gate receiving an input current and a drain receiving a driving current. The voltage level shifting unit providing a voltage shift is coupled between the drain of the first transistor and the gate of the second transistor. An output current is generated at the drain of the second transistor.Type: ApplicationFiled: December 8, 2015Publication date: March 24, 2016Inventors: Tsun-Yuan FAN, Wen-Hua CHANG
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Patent number: 9276597Abstract: An analog-to-digital converter is provided. Each pre-amplifier provides a pair of differential outputs according to a pair of differential analog input signals and a first reference voltage and a second reference voltage from a resistor chain, wherein the first reference voltage is different from the second reference voltage. Each dynamic comparator provides a first comparing signal and a second comparing signal according to the pair of differential outputs of the pre-amplifier. Each pre-amplifier includes a first calibration unit for calibrating a first offset voltage from the pre-amplifier at the pair of differential outputs at a specific temperature, and a second calibration unit for calibrating a second offset voltage from the corresponding dynamic comparator at the pair of differential outputs.Type: GrantFiled: February 10, 2015Date of Patent: March 1, 2016Assignee: MEDIATEK INC.Inventor: Wen-Hua Chang
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Patent number: 9203423Abstract: A signal generation apparatus includes a digital-to-analog converter, a bias stage and a class AB output stage. The digital-to-analog converter is arranged for outputting a current as an input signal. The bias stage is coupled to the digital-to-analog converter, and is arranged for generating a bias signal according to at least the input signal. The class AB output stage is coupled to the bias stage, and is arranged for generating an output signal at an output node of the signal generation apparatus according to the bias signal, wherein the output signal includes a first signal component and a second signal component, both the first signal component and the second signal component correspond to the input signal, and there is a linear relation between the output signal and the input signal.Type: GrantFiled: August 22, 2013Date of Patent: December 1, 2015Assignee: MEDIATEK INC.Inventor: Wen-Hua Chang
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Publication number: 20150258657Abstract: A grinding wheel includes a base disk, and a plurality of teeth protruding beyond a surface of the base disk. The plurality of teeth is aligned to an elongated ring encircling a center of the grinding wheel.Type: ApplicationFiled: May 29, 2015Publication date: September 17, 2015Inventors: Chun-Hsing Su, Jing-Cheng Lin, Tsei-Chung Fu, Wen-Hua Chang, Yi-Chao Mao
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Publication number: 20150193043Abstract: A touch input device including a carrying board, a plurality of first electrode pads, and a plurality of conductive lines is provided. The carrying board includes a plurality of cantilever portions and a plurality of connecting portions. The connecting portions are respectively connected to the cantilever portions. The first electrode pads are respectively disposed on the cantilever portions and configured to sense capacitance variation due to an object approaching or touching the carrying board. The conductive lines extend on the connecting portions and are respectively connected to the first electrode pads. A manufacturing method of a touch input device and a touch sensing method are also provided.Type: ApplicationFiled: April 6, 2014Publication date: July 9, 2015Applicant: Wistron CorporationInventors: Sweehan J.H. Yang, Tung-Yang Tang, Wen-Hua Chang, Yong-Yu Chen
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Publication number: 20150054584Abstract: A signal generation apparatus includes a digital-to-analog converter, a bias stage and a class AB output stage. The digital-to-analog converter is arranged for outputting a current as an input signal. The bias stage is coupled to the digital-to-analog converter, and is arranged for generating a bias signal according to at least the input signal. The class AB output stage is coupled to the bias stage, and is arranged for generating an output signal at an output node of the signal generation apparatus according to the bias signal, wherein the output signal includes a first signal component and a second signal component, both the first signal component and the second signal component correspond to the input signal, and there is a linear relation between the output signal and the input signal.Type: ApplicationFiled: August 22, 2013Publication date: February 26, 2015Applicant: MEDIATEK INC.Inventor: Wen-Hua Chang
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Publication number: 20140361836Abstract: A current amplifier and a transmitter using the same. The current amplifier includes: a first transistor having a gate coupled to a former-stage circuit, a drain coupled to a current source, and a source biased at a constant voltage level; a second transistor having a gate coupled to the current source and having a source and a drain; a first impedance circuit coupled between the gate of the first transistor and the source of the second transistor; and a second impedance circuit coupled between the source of the second transistor and a ground terminal The current amplifier receives an input current from the former-stage circuit and generates an output current at the drain of the second transistor. Note that no current source is connected to the source of the first transistor.Type: ApplicationFiled: June 5, 2013Publication date: December 11, 2014Inventors: Wen-Hua CHANG, Tsung-Yi CHOU
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Patent number: 8836565Abstract: An analog to digital converter can operate in a sampling mode or in a comparing mode. The analog to digital converter comprises: a comparator; a first capacitor, comprising a first terminal coupled to a first input terminal of the comparator; a second capacitor; a first switch module; a control unit, for controlling the conductive states of the first switch module corresponding to the sampling mode or the comparing mode. The first capacitor samples a value of a first input signal and the second capacitor samples a value of a first reference signal via the first switch module in the sampling mode. The first capacitor and the second capacitor are not coupled to each other in the sampling mode. The first capacitor and the second capacitor are coupled in series via the first switch module in the comparing mode.Type: GrantFiled: September 27, 2013Date of Patent: September 16, 2014Assignee: Mediatek Inc.Inventor: Wen-Hua Chang
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Patent number: 8285228Abstract: A signal transmitting circuit includes: a signal generating circuit arranged to generate an output signal to a loading device according to an input signal; an adjusting circuit; and a matching circuit having a first port coupled to the adjusting circuit and a second port coupled to the signal generating circuit, wherein the second port is arranged to couple to the loading device so as to provide a matching impedance corresponding to the loading device; and the adjusting circuit is arranged to generate an adjusting signal of which a voltage applied on the first port is substantially equal to a voltage of the output signal applied on the second port.Type: GrantFiled: April 12, 2010Date of Patent: October 9, 2012Assignee: Mediatek Inc.Inventor: Wen-Hua Chang
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Patent number: 8222927Abstract: A reference buffer circuit is provided, comprising a reference buffering stage and a driving stage. The buffering stage provides a first driving voltage based on a first input voltage. The driving stage is driven by the first driving voltage to output a first output voltage. In the buffering stage, a first operational amplifier has a first input end for receiving the first input voltage, a second input end, and an output end for outputting a first tracking voltage. A first level shifter is coupled to the output end of the first operational amplifier, shifting a level of the first tracking voltage to generate the first driving voltage. A first buffering transistor has a drain coupled to a first supply voltage, a source connected to the second input end of the first operational amplifier, and a gate coupled to the first charge pump for receiving the first driving voltage.Type: GrantFiled: April 9, 2009Date of Patent: July 17, 2012Assignee: Mediatek Inc.Inventors: Chieh-Wei Liao, Wen Hua Chang, Tse-Hsiang Hsu
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Patent number: 8111178Abstract: A capacitor array includes a plurality of capacitor components each having a first node and a second node, and first nodes of the capacitor components are coupled to each other. A calibration method for the capacitor array utilizes a calibration capacitor component to couple the first nodes. Then, the calibration method determines a capacitance indication value regarding the specific capacitor component by coupling different references voltage to a second node of the specific capacitor component and coupling different test voltages to a second node of the calibration capacitor component. Accordingly, the calibration method calibrates the capacitance mismatches of the capacitor array in the digital domain.Type: GrantFiled: November 26, 2009Date of Patent: February 7, 2012Assignee: Mediatek Inc.Inventors: Chieh-Wei Liao, Chia-Hua Chou, Tse-Hsiang Hsu, Wen-Hua Chang
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Publication number: 20110249711Abstract: A signal transmitting circuit includes: a signal generating circuit arranged to generate an output signal to a loading device according to an input signal; an adjusting circuit; and a matching circuit having a first port coupled to the adjusting circuit and a second port coupled to the signal generating circuit, wherein the second port is arranged to couple to the loading device so as to provide a matching impedance corresponding to the loading device; and the adjusting circuit is arranged to generate an adjusting signal of which a voltage applied on the first port is substantially equal to a voltage of the output signal applied on the second port.Type: ApplicationFiled: April 12, 2010Publication date: October 13, 2011Inventor: Wen-Hua Chang
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Publication number: 20110122006Abstract: A capacitor array includes a plurality of capacitor components each having a first node and a second node, and first nodes of the capacitor components are coupled to each other. A calibration method for the capacitor array utilizes a calibration capacitor component to couple the first nodes. Then, the calibration method determines a capacitance indication value regarding the specific capacitor component by coupling different references voltage to a second node of the specific capacitor component and coupling different test voltages to a second node of the calibration capacitor component. Accordingly, the calibration method calibrates the capacitance mismatches of the capacitor array in the digital domain.Type: ApplicationFiled: November 26, 2009Publication date: May 26, 2011Inventors: Chieh-Wei Liao, Chia-Hua Chou, Tse-Hsiang Hsu, Wen-Hua Chang
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Publication number: 20100259303Abstract: A reference buffer circuit is provided, comprising a reference buffering stage and a driving stage. The buffering stage provides a first driving voltage based on a first input voltage. The driving stage is driven by the first driving voltage to output a first output voltage. In the buffering stage, a first operational amplifier has a first input end for receiving the first input voltage, a second input end, and an output end for outputting a first tracking voltage. A first level shifter is coupled to the output end of the first operational amplifier, shifting a level of the first tracking voltage to generate the first driving voltage. A first buffering transistor has a drain coupled to a first supply voltage, a source connected to the second input end of the first operational amplifier, and a gate coupled to the first charge pump for receiving the first driving voltage.Type: ApplicationFiled: April 9, 2009Publication date: October 14, 2010Applicant: MEDIATEK INC.Inventors: Chieh-Wei Liao, Wen Hua Chang, Tse-Hsiang Hsu
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Patent number: 7464258Abstract: Disclosed is a method of displaying foreground visual data in foreground and executing system booting in background for a computer system, including the following steps: a computer system detecting a pre-configured hot key being pressed; the computer system being activated and executing the BIOS; the BIOS loading and executing the monitor driver, and loading a default animation related to the applications associated with the pre-configured hot key; the monitor displaying the default animation while operating system being loaded and executed; and finally, after the initialization of the operating system, the application programs associated with the pre-configured hot key being loaded and executed.Type: GrantFiled: October 5, 2005Date of Patent: December 9, 2008Assignee: Mitac Technology Corp.Inventor: Wen-Hua Chang
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Publication number: 20070022282Abstract: Disclosed is a method of displaying foreground visual data in foreground and executing system booting in background for a computer system, including the following steps: a computer system detecting a pre-configured hot key being pressed; the computer system being activated and executing the BIOS; the BIOS loading and executing the monitor driver, and loading a default animation related to the applications associated with the pre-configured hot key; the monitor displaying the default animation while operating system being loaded and executed; and finally, after the initialization of the operating system, the application programs associated with the pre-configured hot key being loaded and executed.Type: ApplicationFiled: October 5, 2005Publication date: January 25, 2007Inventor: Wen-Hua Chang
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Publication number: 20060065162Abstract: A dual functional desk with tilt-adjustable tops includes a stand frame; a front top mounted to an upper front portion of the stand frame via a front tilt control device; and a rear top including a screen support and mounted to an upper rear portion of the stand frame via a rear tilt control device. A computer, TV, or PDA screen may be mounted on the screen support, and the front and the rear top may be separately adjusted to different tilt angles best for writing, reading, or drawing at the front top, or watching the screen mounted on the rear top. When the screen is not in use, the front and the rear top may be simultaneously restored to a horizontal state or adjusted to the same plane with the screen invisibly located below the rear top to increase the usable area on the desk.Type: ApplicationFiled: September 24, 2004Publication date: March 30, 2006Inventors: Yueh Chi, Wen-Hua Chang, Hungh-Hsiang Wang
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Publication number: 20060065167Abstract: A desk with tilt-adjustable tops includes a stand frame; a front top mounted to an upper front portion of the stand frame via a front tilt control device; and a rear top mounted to an upper rear portion of the stand frame via a rear tilt control device. The stand frame is height-adjustable and has a storage box located below a rear portion of the front top. The front and the rear top may be separately adjusted to different tilt angles best for writing, drawing, or reading at the desk. In normal time, the front and the rear top may be simultaneously restored to a horizontal state or adjusted to the same plane with the storage box invisibly located below the front top, so that the desk is used as a general desk with a flat top.Type: ApplicationFiled: September 24, 2004Publication date: March 30, 2006Inventors: Yueh Chi, Wen-Hua Chang, Hungh-Hsiang Wang
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Publication number: 20060065166Abstract: A dual functional desk with tilt-adjustable tops includes a stand frame; a front top mounted to an upper front portion of the stand frame via a front tilt control device; and a rear top including a screen support and mounted to an upper rear portion of the stand frame via a rear tilt control device. A computer, TV, or PDA screen may be mounted on the screen support, and the front and the rear top may be separately adjusted to different tilt angles best for writing, reading, or drawing at the front top, or watching the screen mounted on the rear top. When the screen is not in use, the front and the rear top may be simultaneously restored to a horizontal state or adjusted to the same plane with the screen invisibly located below the rear top to increase the usable area on the desk.Type: ApplicationFiled: September 30, 2004Publication date: March 30, 2006Inventors: Yueh Chi, Wen-Hua Chang, Hungh-Hsiang Wang