Apple Inc.

Cheng-Chih Hsieh

Tsung-Ting Tsai

Ting-Kuo Chang

Abbas Jamshidi Roudbari

Shyuan Yang

Shih Chang Chang

Warren S Rieutort-Louis

Bhadrinarayana Lalgudi Visweswaran

Chuang Qian

Shih-Chang Chang

Jae Won Choi

Yuchi Che

Yun Yu Wang

Chin-Wei Lin

Jean-Pierre Simon Guillou

Prashant Mandlik

Christopher Edward Glazowski

Shang-Chih Lin

Fan Gui

Takahide Ishii

Mohammad Reza Esmaeili Rad

Ricardo A Peterson

Han Liu

Ran Tu

Xin Lin

Kyounghwan Kim

Chia-hao Chang

Themistoklis Afentakis

Ankit Mahajan

Jonathan H Beck

Aida Raquel Colon-Berrios

Hui Lu

Levent Erdal Aygun

Ko-Wei Chen

David L Wei

Asli Sirman

An electronic device may have a display such as an organic light-emitting diode display. The organic light-emitting diode (OLED) display may have an array of organic light-emitting diode pixels that each have OLED layers interposed between a cathode and an anode. A first passivation layer, a first planarization layer, and a second passivation layer may be formed over the cathode. The first and second passivation layers may be formed from inorganic material. A second planarization layer may be formed over the second passivation layer between the second passivation layer and a polarizer. The second planarization layer may planarize the polarizer at the edges of the active area of the display where the polarizer would otherwise have a steep taper. Planarizing the polarizer in this way mitigates undesirable secondary reflections off of the polarizer. The first and second planarization layers may be formed from organic material.

Organic light-emitting diode displays with planarization layers

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

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

Electronic devices may include displays having organic light-emitting diode pixels, display driver circuitry, and gate driver circuitry. To reduce the amount of space occupied in the inactive area of a display by the gate driver circuitry, one or more of the shift registers in the gate driver circuitry may include register circuits that are shared by multiple rows of pixels. Different drivers may use different clock frequencies to ensure synchronous operation of the display even when some register circuits share pixel rows. For increased flexibility in the arrangement of the register circuits in the shift registers, one or more of the shift registers may be split across the active area of the display. In some cases, one of the emission drivers may be omitted from the gate driver circuitry and a single emission driver may provide multiple emission control signals for the pixels.

Displays with gate driver circuitry having shared register circuits

A display may have an array of organic light-emitting diode display pixels operating at a low refresh rate. 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. A silicon transistor may be further interposed between the semiconducting-oxide transistor and the gate terminal of the drive transistor. One or more capacitor structures may be coupled to the source terminal and/or the drain terminal of the semiconducting-oxide transistor to reduce rebalancing current that might flow through the semiconducting-oxide transistor as it is turned off. Configured in this way, any emission current flowing through the OLED will be insensitive to any potential drift in the threshold voltage of the semiconducting-oxide transistor.

Electronic devices having low refresh rate display pixels with reduced sensitivity to oxide transistor threshold voltage

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Santa Clara, CA, United States of America

Cheng-Chih Hsieh