Patents by Inventor Kingsuk Brahma
Kingsuk Brahma 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: 20200335046Abstract: Techniques for implementing and/or operating an electronic device, which includes a display pixel that emits light to facilitate displaying an image during an emission period and a data driver coupled to the display pixel via a data line. The data driver generates a data line voltage signal based on image data that indicates target luminance of the display pixel in the image and supplies the data line voltage signal to the data line during a non-emission period preceding the emission period to facilitate writing the image to the display pixel. Additionally, the data driver supplies an intermediate voltage greater than a ground voltage to the data line during the emission period in which the image is displayed to facilitate reducing luminance variation in the image resulting from a leakage current flowing between an internal node of the display pixel and the data line during the emission period.Type: ApplicationFiled: April 16, 2020Publication date: October 22, 2020Inventors: Jie Won Ryu, Myungjoon Choi, Hyunsoo Kim, Hyunwoo Nho, Chin-Wei Lin, Shiping Shen, Kingsuk Brahma, Chaohao Wang, Shinya Ono, Alex H. Pai, Hassan Edrees
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Publication number: 20200335040Abstract: An electronic device includes a display having multiple regions of pixels. Each pixel includes a diode that emits light based on an amount of current through the diode and a transistor that controls the amount of current flowing through the diode. The electronic device includes driver-integrated circuitry that reduces hysteresis in a first transistor of a first pixel of a region of pixels, settles a threshold voltage of the first transistor, applies a test voltage to the first transistor, and senses a current across the first transistor. The electronic device includes processing circuitry that determines a predetermined voltage based on the current and a predetermined current-voltage relationship determined at an initial temperature, determines a voltage difference between the test voltage and the predetermined voltage, and applies the predetermined voltage and the voltage difference to a second transistor of a second pixel of the region of pixels.Type: ApplicationFiled: February 26, 2020Publication date: October 22, 2020Inventors: Hyunwoo Nho, Myungjoon Choi, Hyunsoo Kim, Mohammad Ali Jangda, Jie Won Ryu, Shiping Shen, Kingsuk Brahma, Chaohao Wang, Wei H. Yao, Alex H. Pai
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Publication number: 20200302856Abstract: A system includes an electronic display panel that has a plurality of pixels configured to depict frames of image data. The electronic display also includes display driver circuitry configured to, for a first frame of image data representing first image content, modify a gate-to-source voltage of a transistor of a first pixel of the plurality of pixels to a content-dependent first gate-to-source voltage. Additionally, after modifying the gate-to-source voltage to the first gate-to-source voltage, the display driver circuitry is configured to program the first pixel by modifying the gate-to-source voltage to a gate-to-source programming voltage that differs from the first gate-to-source voltage and is based on image data associated with the pixel from the first frame of the image data. Furthermore, the display driver circuitry is configured to cause the plurality of pixels to emit light.Type: ApplicationFiled: January 17, 2020Publication date: September 24, 2020Inventors: Xin Lin, Yun Wang, Chin-Wei Lin, Majid Gharghi, Fan Gui, Chen-Ming Chen, Jie Won Ryu, Hyunwoo Nho, Alex H. Pai, Kingsuk Brahma, Junhua Tan, Szu Heng Tseng
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Patent number: 10777106Abstract: An electronic device includes a display having a number of pixels, source driving circuitry that drives data to the pixels, and data lines that communicatively couple the source driving circuitry with the pixels. The electronic device also includes quality monitoring and calibration circuitry that identifies degradation in the source driving circuitry, one or more of the data lines, or both. The electronic device may be controlled based at least in part upon identification of the degradation.Type: GrantFiled: September 27, 2017Date of Patent: September 15, 2020Assignee: Apple Inc.Inventors: Hung Sheng Lin, Jie Won Ryu, Kingsuk Brahma, Hyunwoo Nho, Baris Cagdaser, Junhua Tan, Sun-Il Chang, Luigi Panseri, Injae Hwang, Jesse A. Richmond, Toshiaki Sawada, Hyuck-Jae Lee
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Patent number: 10755618Abstract: Systems and methods are provided for differential sensing (DS), difference-differential sensing (DDS), correlated double sampling (CDS), correlated-correlated double sampling (CDS-CDS) and/or programmable capacitor matching to reduce display panel sensing noise. An electronic device may include one or more processors that generate image data according to sensing operations. The one or more processors may reference a sensing pattern as part of sensing operations. Applying test sensing signals based on the sensing pattern may help reduce error associated with sensing operations.Type: GrantFiled: April 19, 2019Date of Patent: August 25, 2020Assignee: Apple Inc.Inventors: Hung Sheng Lin, Shengkui Gao, Hyunwoo Nho, Chin-Wei Lin, Mohammad B. Vahid Far, Jie Won Ryu, Kingsuk Brahma, Junhua Tan, Sun-Il Chang, Shinya Ono, Jesse Aaron Richmond, Yafei Bi, Derek K. Shaeffer, Myungjoon Choi, Shiping Shen
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Patent number: 10642083Abstract: Electronic devices and methods for compensating for temperature-dependent fluctuations in a display include receiving a temperature index may be received from a sensor and/or calculations that indicates a temperature of the system, a pixel, a panel, a grid of a panel, or a combination thereof. The temperature is used to predict a voltage change across an emissive element (VHILO), such as an organic light emitting diode (OLED). This predicted voltage change is then compensated for before emission.Type: GrantFiled: June 14, 2018Date of Patent: May 5, 2020Assignee: Apple Inc.Inventors: Injae Hwang, Rui Zhang, Hung Sheng Lin, Hyunsoo Kim, Hyunwoo Nho, Jesse A. Richmond, Jie Won Ryu, Junhua Tan, Kingsuk Brahma, Shengkui Gao, Shiping Shen, Sun-Il Chang
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Publication number: 20200118486Abstract: An electronic device comprises an electronic display having an active area having a pixel. The electronic device also comprises processing circuitry configured to receive image data to send to the pixel and adjust the image data to generate corrected image data based at least in part on a stored correction value for the pixel. The processing circuitry also is configured to generate a test data to send to the pixel subsequent to sending corrected image data to the pixel, wherein the test data is selected based upon a comparison of at least one aspect of the corrected image data with a threshold value.Type: ApplicationFiled: March 27, 2018Publication date: April 16, 2020Inventors: Hung Sheng Lin, Hyunwoo Nho, Sun-Il Chang, Junhua Tan, Jie Won Ryu, Shengkui Gao, Rui Zhang, Injae Hwang, Kingsuk Brahma, Jesse Aaron Richmond, Shiping Shen, Hyunsoo Kim
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Patent number: 10573211Abstract: Systems and methods are provided for differential sensing (DS), difference-differential sensing (DDS), correlated double sampling (CDS), and/or programmable capacitor matching to reduce display panel sensing noise. An electronic device may include one or more processors and an electronic display. The one or more processors may generate image data and adjust the image data based at least in part on display sensing feedback. The electronic display may employ sensing circuitry that obtains the display sensing feedback at least in part by applying test data to a pixel of a column of an active area of the display and differentially senses an electrical value of the pixel in comparison to a reference signal from a different column. This reference signal may provide a common mode noise reference, which is removed by the differential sensing and thereby enhances a quality of the sensed electrical value of the pixel.Type: GrantFiled: March 21, 2019Date of Patent: February 25, 2020Assignee: Apple Inc.Inventors: Hung Sheng Lin, Shengkui Gao, Hyunwoo Nho, Chin-Wei Lin, Mohammad B. Vahid Far, Jie Won Ryu, Kingsuk Brahma, Junhua Tan, Sun-Il Chang, Shinya Ono, Jesse A. Richmond, Yafei Bi, Derek K. Shaeffer
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Patent number: 10573234Abstract: A method for operating an electronic display includes displaying image frames and receiving operational parameters of the electronic display based on illuminating a sense pixel of at least one row of pixels of the electronic display when displaying the image frames. A first set of pixels below the at least one row of pixels renders a portion of a first image frame and a second set of pixels above the at least one row of pixels renders a portion of a second image frame. The method also includes adjusting image display of a third image frame on the electronic display based on the operational parameters.Type: GrantFiled: July 30, 2018Date of Patent: February 25, 2020Assignee: Apple Inc.Inventors: Hung Sheng Lin, Hyunwoo Nho, Chaohao Wang, Jie Won Ryu, Kingsuk Brahma, Shiping Shen, Shengkui Gao, Hyunsoo Kim, Sun-Il Chang, Junhua Tan, Injae Hwang, Myungjoon Choi
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Patent number: 10564774Abstract: Methods for mitigation of sensing error effects in display panels are disclosed. Display panels, such as pixel-based panels, may have circuitry to sense the luminance values, compare measurements with target luminance values, and provide corrections. Sensing errors, such as ones caused by sensor hysteresis and thermal fluctuations, may lead to overcorrections and visible artifacts. Mitigations schemes discussed herein include filtering of sensed signal with low pass filters, partial correction strategies, and feedforward sensing schemes. Circuitry that implements these schemes are also discussed.Type: GrantFiled: June 14, 2018Date of Patent: February 18, 2020Assignee: Apple Inc.Inventors: Sun-Il Chang, Myung-Je Cho, Kingsuk Brahma, Jesse A. Richmond, Hyunsoo Kim, Shiping Shen, Injae Hwang, Rui Zhang, Shengkui Gao, Hung Sheng Lin, Jie Won Ryu, Junhua Tan, Hyunwoo Nho
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Patent number: 10565923Abstract: Electronic devices and methods for compensating for noise in a display that includes sensing a current in a sensing channel of the display. Compensating for the noise also includes sensing an observation current from noise in an observation channel of the display and scaling the observation current to generate a scaled observation current. The scaled observation current is subtracted from the sense current to generate a compensated output. The compensated output is used to drive compensation operations of the display based at least in part on the compensated output to reduce effects of the noise.Type: GrantFiled: September 11, 2017Date of Patent: February 18, 2020Assignee: Apple Inc.Inventors: Shiping Shen, Derek K. Shaeffer, Baris Cagdaser, Hyunwoo Nho, Kingsuk Brahma, Hung Sheng Lin, Injae Hwang, Jie Won Ryu, Hyunsoo Kim, Junhua Tan, Rui Zhang, Shengkui Gao, Mohammad B Vahid Far, Jesse A. Richmond, Sun-Il Chang
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Patent number: 10559238Abstract: Systems and methods are provided for differential sensing (DS), difference-differential sensing (DDS), correlated double sampling (CDS), and/or programmable capacitor matching to reduce display panel sensing noise. An electronic device may include one or more processors and an electronic display. The one or more processors may generate image data and adjust the image data based at least in part on display sensing feedback. The electronic display may employ sensing circuitry that obtains the display sensing feedback at least in part by applying test data to a pixel of a column of an active area of the display and differentially senses an electrical value of the pixel in comparison to a reference signal from a different column. This reference signal may provide a common mode noise reference, which is removed by the differential sensing and thereby enhances a quality of the sensed electrical value of the pixel.Type: GrantFiled: September 7, 2017Date of Patent: February 11, 2020Assignee: Apple Inc.Inventors: Hung Sheng Lin, Shengkui Gao, Hyunwoo Nho, Chin-Wei Lin, Mohammad B Vahid Far, Jie Won Ryu, Kingsuk Brahma, Junhua Tan, Sun-II Chang, Shinya Ono, Jesse A Richmond, Yafei Bi, Derek K. Shaeffer
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Patent number: 10541280Abstract: A touch screen configured for optical touch sensing and user identification using organic light emitting diodes (OLEDs) is disclosed. In some examples, one or more OLEDs can be used to display one or more images on the device, can be configured to emit light for optical touch sensing, and/or can be configured to detect a reflection of the emitted light. The touch screen can include a spatial filter configured to focus light emitted from the OLEDs and/or reflected light detected by the OLEDs for improved optical touch sensing. Using optical touch sensors, the touch screen can be capable of discerning between water and an object (e.g., finger) and/or noise (e.g., ambient light) and an object. The touch screen can also be capable of identifying (e.g., authenticating) a user using the active area of the device.Type: GrantFiled: September 15, 2017Date of Patent: January 21, 2020Assignee: Apple Inc.Inventors: Christoph H. Krah, Kingsuk Brahma
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Patent number: 10535287Abstract: Systems and methods are provided for improving displayed image quality of an electronic display that includes a display pixel. The electronic display displays a first image frame directly after a second image frame by applying an analog electrical signal to the display pixel. To facilitate display of the first image frame, circuitry receives image data corresponding to the image frame, in which the image data includes a grayscale value that indicates target luminance of the display pixel; determines expected refresh rate of the first image frame based at least in part on actual refresh rate of the second image frame; determines a pixel response correction offset based at least in part on the expected refresh rate of the first image frame; and determines processed image data by applying the pixel response correction offset to the grayscale value, in which the processed image data indicates magnitude of the analog electrical signal.Type: GrantFiled: September 24, 2016Date of Patent: January 14, 2020Assignee: Apple Inc.Inventors: Chaohao Wang, Lu Zhang, Zhibing Ge, Shih-Chyuan Fan Jiang, Ilie Garbacea, Marc Albrecht, Kingsuk Brahma, Hopil Bae, Paolo Sacchetto, Jie Won Ryu, Sandro H. Pintz, Chengrui Le
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Publication number: 20200005716Abstract: The present disclosure relates generally to systems and methods that may reduce a reduction in visual artifacts related to hysteresis of a light emitting diode (LED) electronic display. In one example, an electronic device may include a controller. The controller is may provide a signal to a pixel of a display of the electronic device while at least a portion of the display is turned off. The signal may include a first current and a second current. The first current may be designed to increase an ambient temperature corresponding to the pixel. The second current may be generated as part of an active panel conditioning operation. By applying the first current and the second current, hysteresis settling times from the pixel may improve, therefore improving speeds of sensing and compensation operations of the electronic device.Type: ApplicationFiled: September 11, 2019Publication date: January 2, 2020Inventors: Junhua Tan, Kingsuk Brahma, Jie Won Ryu, Shengkui Gao, Shiping Shen, Majid Gharghi, Hyunwoo Nho, Injae Hwang, Kavinaath Murugan, Sun-Il Chang, Chin Wei Lin, Hyunsoo Kim, Rui Zhang, Jesse Aaron Richmond, Yun Wang, Hung Sheng Lin, Alex H. Pai, Chaohao Wang, Wei H. Yao
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Patent number: 10504426Abstract: An electronic device includes a display panel. The display panel includes a plurality of pixels, each of which includes a driving thin-film-transistor (TFT) configured to receive driving data related to the operation of a respective pixel and a light-emitting diode configured to emit light based on the driving data provided to the TFT. The display panel also includes compensation circuitry configured to generate offset data from compressed offset data and apply the offset data to the pixel data to generate the driving data.Type: GrantFiled: September 12, 2017Date of Patent: December 10, 2019Assignee: Apple Inc.Inventors: Jesse Aaron Richmond, Mohammad B. Vahid Far, Yafei Bi, Kingsuk Brahma
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Patent number: 10474860Abstract: An electronic device may include a display and a biometric image sensor configured for biometric image sensing. The electronic device may also include a display driver coupled to the display. The display driver may include first and second memories and a processor configured to alternatingly read respective illumination pattern data from the first and second memories to drive the display during biometric image sensing.Type: GrantFiled: September 29, 2017Date of Patent: November 12, 2019Assignee: APPLE INC.Inventors: Mohammad Yeke Yazdandoost, Yafei Bi, Kingsuk Brahma, Giovanni Gozzini, Mohammad Jangda
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Patent number: 10438535Abstract: A display device may include a plurality of pixels that display image data on a display, a digital-to-analog converter that outputs a voltage that corresponds to a luminance value to be depicted on a first pixel, and a circuit that amplifies the voltage and outputs an amplified voltage to the first pixel. The circuit may include a capacitor that receives the voltage via the digital-to-analog converter and an amplifier coupled to the capacitor. The amplifier generates the amplified voltage based on the voltage stored the capacitor. The circuit also include switches that couple a first terminal of the capacitor to an output of the amplifier during a first amount of time and couples a second terminal of the capacitor to the output of the amplifier after the first amount of time expires.Type: GrantFiled: September 6, 2017Date of Patent: October 8, 2019Assignee: Apple Inc.Inventors: Derek K. Shaeffer, Jesse A. Richmond, Kenichi Ueno, Kingsuk Brahma, Mohammad B. Vahid Far, Shingo Hatanaka, Yafei Bi
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Patent number: 10424244Abstract: Aspects of the subject technology relate to electronic devices with displays. A display may include an array of display pixels each having a drive transistor and an organic light-emitting diode. A pulse-width-modulated current may be provided to the organic light-emitting diode during each display frame to compensate for an on-bias compensation applied to the drive transistor between display frames. The pulse-width-modulated current may be provided with a pulse-width-modulation ratio that decreases over the course of each display frame. The decrease of the pulse-width-modulation ratio for each display frame may be determined based on a peak luminance for that display frame. The reduction in flicker provided by the pulse-width-modulated current may facilitate operation of the display with a reduced refresh rate, thereby reducing power consumption by the display.Type: GrantFiled: January 11, 2017Date of Patent: September 24, 2019Assignee: Apple Inc.Inventors: Chengrui Le, Chaohao Wang, Kingsuk Brahma, Jie Won Ryu, Chin-Wei Lin, Rui Zhang
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Patent number: 10394359Abstract: A sensing device can be included in a display of an electronic device. Various techniques can be used to reduce display noise in the signals output from the sensing device. The techniques include the use of a filtering layer in a display stack, the use of a non-uniform sampling scheme, averaging together noise signal samples sampled over multiple display frames, and inverting a phase of the sampling of the noise signal over multiple display frames.Type: GrantFiled: August 4, 2017Date of Patent: August 27, 2019Assignee: Apple Inc.Inventors: Manu Agarwal, Erno H. Klaassen, Hopil Bae, Kingsuk Brahma