公开(公告)号：US20190311680A1

公开(公告)日：2019-10-10

申请号：US16048217

申请日：2018-07-27

Applicant: Apple Inc.

Inventor： Kyung Hoae Koo ,  Weijun Yao ,  Yue Jack Chu ,  Kaige Sun

IPC: G09G3/3266

Abstract: Display artifacts, such as muras, may be perceptible on an electronic display when an electronic device includes a radio frequency transceiver that outputs electromagnetic waves during an emission period and a display panel that writes to display pixels during a refresh period. The electronic device may also include a controller that is coupled to the radio frequency transceiver and the display panel and facilitates the reduction and/or elimination of overlap between the emission periods and the refresh periods to decrease the appearance of display artifacts. In particular, the controller may execute instructions to determine the duration of the emission period and determine the duration of the blanking period that occurs between the refresh periods. Further, based on the determined blanking period and emission period durations, the controller may instruct the radio frequency transceiver to adjust the timing of the first emission period, instruct the display panel to adjust the timing of the refresh rate, or both to reduce overlap.

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.

Inventor： Jiayi Jin ,  David A. Doyle ,  Kyung Hoae Koo ,  Maofeng Yang ,  Michael H. Lim ,  Paolo Sacchetto ,  Timothy M. Johnson ,  Venkatesh Rajendran ,  Weijun Yao ,  Yue Jack Chu

IPC: G09G3/3258 ,  G09G3/3266

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.

公开(公告)号：US11081053B2

公开(公告)日：2021-08-03

申请号：US16283481

申请日：2019-02-22

Applicant: Apple Inc.

Inventor： Jiayi Jin ,  David A. Doyle ,  Kyung Hoae Koo ,  Maofeng Yang ,  Michael H. Lim ,  Paolo Sacchetto ,  Timothy M. Johnson ,  Venkatesh Rajendran ,  Weijun Yao ,  Yue Jack Chu

IPC: G09G3/3258 ,  G09G3/3266 ,  H01L29/786

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.

公开(公告)号：US20210012711A1

公开(公告)日：2021-01-14

申请号：US16505556

申请日：2019-07-08

Applicant: Apple Inc.

Inventor： Ruo-Gu Huang ,  Kyung Hoae Koo ,  Michael H. Lim ,  Chuang Qian ,  Weijun Yao ,  Yue Jack Chu

IPC: G09G3/3233 ,  G09G3/3291

Abstract: A display driver is disclosed that reduces first frame dimming and flicker in light-emitting diode pixels of a display device. The display driver may receive a display brightness value and determine a value of a dynamic supply voltage parameter based on the display brightness value. Over a first time interval, the display driver may apply a supply voltage that is based on the dynamic supply voltage parameter to one of a gate of a drive transistor of a light-emitting-diode circuit and a channel of the drive transistor. Over a second time interval, the display driver may apply a parking voltage to an anode of a light-emitting diode of the light-emitting-diode circuit and to the channel of the drive transistor. The value of the parking voltage may be below a threshold voltage of the light-emitting diode and correspond to the value of the dynamic supply voltage parameter.

公开(公告)号：US11145249B1

公开(公告)日：2021-10-12

申请号：US16930204

申请日：2020-07-15

Applicant: Apple Inc.

Inventor： Wanglei Han ,  Akshay Bhat ,  Michael H. Lim ,  Kyung Hoae Koo ,  Jiayi Jin ,  David A. Doyle ,  Tae-Wook Koh ,  Jared S. Price ,  Yifan Zhang ,  Mahdi Nezamabadi

IPC: G09G3/3225 ,  G09G3/00

Abstract: A display may include pixels (such as light-emitting diode pixels) that are susceptible aging effects (burn-in). To help avoid visible artifacts caused by burn-in during operation of the display, compensation circuitry may be used to compensate image data for the display. An optical sensor may be included behind the pixels to directly measure pixel brightness levels. The optical sensor may provide optical sensor data from testing operations to the compensation circuitry. The optical sensor may gather data during burn-in testing operations. During the burn-in testing operations, pixel groups including both high-usage pixels and low-usage pixels may sequentially emit light while the optical sensor gathers data. Brightness differences between the high-usage pixels and low-usage pixels may be used to characterize pixel aging in the display and compensate image data to mitigate visible artifacts caused by burn-in. The optical sensor may also gather data during global brightness testing operations.

公开(公告)号：US10902777B1

公开(公告)日：2021-01-26

申请号：US16505556

申请日：2019-07-08

Applicant: Apple Inc.

Inventor： Ruo-Gu Huang ,  Kyung Hoae Koo ,  Michael H. Lim ,  Chuang Qian ,  Weijun Yao ,  Yue Jack Chu

IPC: G09G3/3291 ,  G09G3/3233

Abstract: A display driver is disclosed that reduces first frame dimming and flicker in light-emitting diode pixels of a display device. The display driver may receive a display brightness value and determine a value of a dynamic supply voltage parameter based on the display brightness value. Over a first time interval, the display driver may apply a supply voltage that is based on the dynamic supply voltage parameter to one of a gate of a drive transistor of a light-emitting-diode circuit and a channel of the drive transistor. Over a second time interval, the display driver may apply a parking voltage to an anode of a light-emitting diode of the light-emitting-diode circuit and to the channel of the drive transistor. The value of the parking voltage may be below a threshold voltage of the light-emitting diode and correspond to the value of the dynamic supply voltage parameter.