Apple Inc.

Shyuan Yang

Tsung-Ting Tsai

Ting-Kuo Chang

Abbas Jamshidi Roudbari

Chin-Wei Lin

Warren S Rieutort-Louis

Chuang Qian

Shinya Ono

Shih-Chang Chang

Cheng-Ho Yu

Yuchi Che

Cheng-Chih Hsieh

John Z Zhong

Hung Sheng Lin

Vasudha Gupta

Yu Cheng Chen

Ricardo A Peterson

Shih Chang Chang

Jean-Pierre Simon Guillou

Yi Qiao

Bhadrinarayana Lalgudi Visweswaran

Yue Cui

Weijun Yao

Shin-Hung Yeh

Jae Won Choi

Yue Jack Chu

Chien-Ya Lee

Graeme M Williams

Ran Tu

Kyounghwan Kim

Yun Yu Wang

Paolo Sacchetto

Yafei Bi

Kingsuk Brahma

Chieh-Wei Chen

Qing Li

Shengkui Gao

Injae Hwang

Mohammad Ali Jangda

Pierre-Yves Emelie

Jiayi Jin

Fan Gui

Haifeng Li

Sinan Alousi

Mohammad Reza Esmaeili Rad

Salman Karbasi

Salman Kabir

Bo-Ren Wang

Xin Lin

Yang Xu

Feng Wen

Mario Miscuglio

Aida Raquel Colon-Berrios

Levent Erdal Aygun

Jonathan H Beck

Snehal T Jariwala

Wenbing Hu

Zhizhen Ma

Junbo Wu

An electronic device may include a display and an optical sensor formed underneath the display. The display may have both a full pixel density region and a high-transmittance region that overlaps the optical sensor. To increase the transmittance of light through the high-transmittance region of the display, emissive sub-pixels in the high-transmittance region may be shorted together. Each emissive sub-pixel may be shorted to an emissive sub-pixel of the same color. The emissive sub-pixels in the high-transmittance region of the display may have the same layout but smaller sizes relative to the full pixel density region of the display. The thin-film transistor sub-pixels in the high-transmittance region may be consolidated horizontally and/or vertically to produce larger continuous high-transmittance areas.

Devices with displays having transparent openings and shorted pixels

A light emitter that operates through a display may cause display artifacts, even when the light emitter operates using non-visible wavelengths. Display artifacts caused by a light emitter that operates through a display may be referred to as emitter artifacts. To mitigate emitter artifacts, a display pixel that overlaps the light emitter may include a transistor that provides a current sink to divert leakage current away from the light-emitting diode in that pixel. A shielding layer may be interposed between the light emitter and a display pixel. The shielding layer may block light from the light emitter. The shielding layer may have an opening that exposes one transistor in the pixel to the light from the light emitter. Pixels that overlap the light emitter may have larger anodes than pixels that do not overlap the light emitter.

Display pixel with a current sink to mitigate artifacts caused by an under-display light emitter

A display may have an array of organic light-emitting diode display pixels operating at a low refresh rate. Each display pixel may have six thin-film transistors and one capacitor. One of the six transistors may serve as the drive transistor and may be compensated using the remaining five transistors and the capacitor. One or more on-bias stress operations may be applied before threshold voltage sampling to mitigate first frame dimming. Multiple anode reset and on-bias stress operations may be inserted during vertical blanking periods to reduce flicker and maintain balance and may also be inserted between successive data refreshes to improve first frame performance. Two different emission signals controlling each pixel may be toggled together using a pulse width modulation scheme to help provide darker black levels.

Electronic devices with low refresh rate display pixels

An electronic device includes a display and a sensor underneath the display. The display has a full pixel density region and a reduced pixel density region. Compared to pixels in the full pixel density region, pixels in the reduced pixel density region can be controlled using overdriven power supply voltages, overdriven scan control signals, different initialization and reset voltages, and can include capacitors and transistors with different physical and electrical characteristics. Gate drivers provide scan signals to pixels in the full pixel density region, whereas overdrive buffers provide overdrive scan signals to pixels in the reduced pixel density region. The pixels in the full pixel density region and the pixels in the reduced pixel density region can be controlled using different black level or gamma settings for each color channel and can be adjusted physically to match luminance, color, as well as to mitigate differences in temperature and aging impact.

Displays having reduced pixel density region with localized tuning

An electronic device comprises a display and a controller. The controller is configured to provide a first frequency refresh rate to the display. The controller is also configured to generate a control signal configured to control emission of a light emitting diode of a display pixel of the display at a second frequency based on whether the first frequency refresh rate of the display is less than a predetermined threshold value.

Device and method for improved LED driving

A display may have an array of pixels. Display driver circuitry may supply data and control signals to the pixels. Each pixel may have seven transistors, a capacitor, and a light-emitting diode such as an organic light-emitting diode. The seven transistors may receive control signals using horizontal control lines. Each pixel may have first and second emission enable transistors that are coupled in series with a drive transistor and the light-emitting diode of that pixel. The first and second emission enable transistors may be coupled to a common control line or may be separately controlled so that on-bias stress can be effectively applied to the drive transistor. The display driver circuitry may have gate driver circuits that provide different gate line signals to different rows of pixels within the display. Different rows may also have different gate driver strengths and different supplemental gate line loading structures.

Light-emitting diode displays

An electronic device may include a display and an optical sensor formed underneath the display. The display may have both a full pixel density region and a pixel removal region with a plurality of high-transmittance areas that overlap the optical sensor. To mitigate reflectance mismatch between the full pixel density region and the pixel removal region, the pixel removal region may include a transition region at one or more edges. In the transition region, one or more components may have a gradual density change between the full pixel density region and a central portion of the pixel removal region. Components that may have a changing density in the transition region include dummy thin-film transistor sub-pixels, dummy anodes, a cathode layer, and a touch sensor metal layer. The transition region may also include anodes that gradually change shape and/or size.

Devices with displays having transparent openings and transition regions

A light emitter that operates through a display may cause display artifacts, even when the light emitter operates using non-visible wavelengths. To mitigate artifacts caused by a light emitter operating through a display, the display may have a higher density of thin-film transistor sub-pixels than emissive sub-pixels. This allows for a region in the display to include emissive sub-pixels but be free of thin-film transistor sub-pixels. The light emitter may operate through this region in the display. Additionally, to reduce the amount of space occupied in the inactive area of a display by gate driver circuitry, at least a portion of the gate driver circuitry may be positioned in the active area of the display. To accommodate the gate driver circuitry, emissive sub-pixels may be laterally shifted relative to corresponding thin-film transistor sub-pixels.

Display with a transmitter under an active area

To reduce the amount of space occupied in the inactive area of a display by gate driver circuitry, at least a portion of the gate driver circuitry may be positioned in the active area of the display. To accommodate the gate driver circuitry, emissive sub-pixels may be laterally shifted relative to corresponding thin-film transistor sub-pixels. This allows for the thin-film transistor sub-pixels to be grouped adjacent to the central area of the active area, leaving room along an edge of the active area to accommodate one or more additional display components such as gate driver circuitry or fanout portions of data lines.

Displays with gate driver circuitry in an active area

A display may have rows and columns of pixels. Gate lines may be used to supply gate signals to rows of the pixels. Data lines may be used to supply data signals to columns of the pixels. The data lines may include alternating even and odd data lines. Data lines may be organized in pairs each of which includes one of the odd data lines and an adjacent one of the even data lines. Demultiplexer circuitry may be configured dynamically during data loading and pixel sensing operations. During data loading, data from display driver circuitry may be supplied, alternately to odd pairs of the data lines and even pairs of the data lines. During sensing, the demultiplexer circuitry may couple a pair of the even data lines to sensing circuitry in the display driver circuitry and then may couple a pair of the odd data lines to the sensing circuitry.

High frame rate display

An electronic device may include a display and a sensor under the display. The display may include pixels having emission transistors that are controlled by emission signals. The emission signals are controlled using a pulse width modulation (PWM) scheme to control the brightness of the display. The emission signals may further include a localized sensor blackout pulse configured to generate a localized sensor blackout region that overlaps with the sensor to reduce any undesired back emission of light emitted from the display. The sensor blackout pulse may be automatically generated periodically or generated in an on-demand basis once per frame, multiple times per frame time, or once every multiple frames. Any luminance degradation caused by the sensor blackout pulse may be compensated by boosting the luminance and/or by extending the duration of each emission on pulse.

Methods and configurations for improving the performance of sensors under a display

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Burlingame, CA, United States of America

Shyuan Yang