Threshold voltage hysteresis compensation

    公开(公告)号:US10755640B2

    公开(公告)日:2020-08-25

    申请号:US15701030

    申请日:2017-09-11

    Applicant: Apple Inc.

    Abstract: Electronic devices, storage medium containing instructions, and methods pertain to determining a target boosted threshold voltage level based at least in part on a target emission threshold voltage level. Using the determined target boosted threshold voltage level, a light emitting diode (LED)-controlling transistor is submitted to voltage stress to boost a threshold voltage of the transistor to the target boosted threshold voltage level during a first portion of a refresh period between first and second emission periods. During a second portion of the refresh period, the voltage stress is de-asserted to settle the threshold voltage to a target emission threshold voltage level for the second emission period. After the voltage is settled, the LED-controlling transistor is driven based at least in part on the target emission threshold voltage level.

    Display Pipeline for Voltage-Dependent Sub-Pixel Uniformity Correction

    公开(公告)号:US20240404445A1

    公开(公告)日:2024-12-05

    申请号:US18328661

    申请日:2023-06-02

    Applicant: Apple Inc.

    Abstract: An electronic device may include a display panel comprising a plurality of display pixels, an image source configured to store image data, and image processing circuitry. The image processing circuitry may receive the image data configured to be displayed by the plurality of display pixels, wherein the image data comprises gray level data for a first display pixel of the plurality of display pixels, convert the gray level data to first voltage data, and select a plurality of compensation maps based on a brightness level of the display panel. The image processing circuitry may also determine a voltage offset value based on the input voltage and the plurality of compensation maps, apply the voltage offset value to the first voltage data to generate compensated voltage data, and convert the compensated voltage data into compensated gray level data for the first display pixel.

    Dynamic Uniformity Compensation for Electronic Display

    公开(公告)号:US20220076629A1

    公开(公告)日:2022-03-10

    申请号:US17528183

    申请日:2021-11-16

    Applicant: Apple Inc.

    Abstract: A system may include an electronic display panel having pixels, where each pixel emits light based on a respective programming signal applied to the pixel. The system may also include processing circuitry to determine a respective control signal upon which the respective programing signal for each pixel is based. The processing circuitry may determine each respective control signal based at least in part on approximations of respective pixel brightness-to-data relationship as defined by a function having variables stored in memory accessible to the processing circuitry.

    Electronic Devices Having Displays With Compensation for Oxide Transistor Threshold Voltage

    公开(公告)号:US20200243012A1

    公开(公告)日:2020-07-30

    申请号:US16283481

    申请日:2019-02-22

    Applicant: Apple Inc.

    Abstract: A display may have an array of organic light-emitting diode display pixels. Each display pixel may include a drive transistor coupled in series with one or more emission transistors and a respective organic light-emitting diode (OLED). A semiconducting-oxide transistor may be coupled between a drain terminal and a gate terminal of the drive transistor to help reduce leakage during low-refresh-rate display operations. To compensate for variations in the threshold voltage of the semiconducting-oxide transistor, the magnitude of a high voltage level of a scan control signal provided to the gate terminal of the semiconducting-oxide transistor may be adjusted. Sensing circuitry may be used to sense a display current while displaying a calibration image. The sensed display current may be compared to an expected display current associated with the calibration image. Processing circuitry may update the high voltage level based on the actual display current compared to the expected display current.

    THRESHOLD VOLTAGE HYSTERESIS COMPENSATION
    6.
    发明申请

    公开(公告)号:US20180090074A1

    公开(公告)日:2018-03-29

    申请号:US15701030

    申请日:2017-09-11

    Applicant: Apple Inc.

    Abstract: Electronic devices, storage medium containing instructions, and methods pertain to determining a target boosted threshold voltage level based at least in part on a target emission threshold voltage level. Using the determined target boosted threshold voltage level, a light emitting diode (LED)-controlling transistor is submitted to voltage stress to boost a threshold voltage of the transistor to the target boosted threshold voltage level during a first portion of a refresh period between first and second emission periods. During a second portion of the refresh period, the voltage stress is de-asserted to settle the threshold voltage to a target emission threshold voltage level for the second emission period. After the voltage is settled, the LED-controlling transistor is driven based at least in part on the target emission threshold voltage level.

    Electronic display visual artifact mitigation

    公开(公告)号:US11271181B1

    公开(公告)日:2022-03-08

    申请号:US16576615

    申请日:2019-09-19

    Applicant: Apple Inc.

    Abstract: An electronic display having pixels and control circuitry to drive the pixels to display image data even during relatively long presentation times without visual artifacts, such as flicker, are provided. The control circuitry may cause the pixel to perform a threshold voltage sampling and pixel programming phase to store image data for the pixel while accounting for a first threshold voltage of the first transistor. Afterward, an on-bias stress phase may cause a threshold voltage of the first transistor of the plurality of transistors to reach a second threshold voltage. Following the on-bias stress phase, a first emission phase may cause the light-emitting diode to emit light in accordance with the image data, and subsequent on-bias stress phases and subsequent emission phases for the duration of the presentation time may take place without a visible flicker artifact.

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