Apple Inc.

Yingying Tang

Chaohao Wang

Sheng Zhang

Yunhui Hou

Wei Hsin Yao

Paolo Sacchetto

Mahesh B Chappalli

Koorosh Aflatooni

Jenny Hu

Scott R Johnston

Peter F Holland

Gokhan Avkarogullari

Woo Shik Jung

Guy Cote

Hung Sheng Lin

Hyunwoo Nho

Warren S Rieutort-Louis

Mohammad Ali Jangda

Christopher Edward Glazowski

Wanqing Xin

Lingtao Wang

Jean-Pierre Simon Guillou

Mohammad Bagher Vahid Far

Marc Albrecht

Yang Li

Jun Li

Tong Chen

Marc Joseph DeVincentis

Shengkui Gao

Tyler Robin Kakuda

Mark T Winkler

Michael J Brown

Arthur L Spence

Xiaokai Li

Yi Qiao

Pierre-Yves Emelie

Sean C Chang

Yuchi Che

Paul C Kelley

Ying-Chih Wang

Chengrui Le

Wenrui Cai

James R Montgomerie

Graeme M Williams

Alexander K Kan

Hao Dong

Mehmet N Agaoglu

Alexey Kornienko

Johan L Piper

Lingyu Hong

Andrey Pokrovskiy

Kasra Omid-Zohoor

Kyounghwan Kim

Yang Xu

Sebastian Knitter

Shaorui Yang

Hei Kam

Jingyu Huang

Giovanni Corradini

Feng Wen

Ximeng Guan

Yuhui Li

Asha G Karvaje

Alexandre V Gauthier

Lu Yan

Na Zhu

Tao Jia

Aishwarya Prem Renu

Martin Kocicka

Andrew D Pangborn

Adria Fores Herranz

Li Tao

Chumin Zhao

Clint M Perlaki

David R Manly

Hyun H Boo

Kevin J Choboter

Devices and methods are provided to overdrive or underdrive a display panel to account for display pixel hysteresis due to several frames of pixel history. An electronic device may include an electronic display and processing circuitry. The electronic display includes a number of display pixels. The processing circuitry may generate image data for the display pixels. The processing circuitry may receive a current frame value of the image data targeted for a first display pixel and, based at least in part on the current frame value and a pixel history of the first display pixel—may indicate a gray level for a number of previous frames—generate a compensated value by which to drive the first pixel to overcome pixel hysteresis to reach the desired luminance at an initial response.

Enhanced overdrive or underdrive for flat panel displays

Systems and methods are described herein to control brightness based on image content or other inputs to a display system. A dual-control system may integrate both slow control operations and fast control operations into a cohesive brightness management system. By using both shorter-term (e.g., fast control) and longer-term (e.g., slow control) brightness adjustment operations, the electronic device may quickly respond to high luminance and high brightness situations that may cause burn-in into the display, image artifacts, or other damage. Responding quickly to these high consumption situations may prevent damage or perceivable upset to an ongoing process, among other benefits.

Content dependent brightness management system

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, operating conditions for a display frame may be used to determine an optimal firing time for the light emitter during that display frame. The operating conditions used to determine the optimal firing time may include emitter operating conditions, display content statistics, display brightness, temperature, and refresh rate. Operating conditions from one or more previous frames may be stored in a frame buffer and may be used to help determine the optimal firing time for the light emitter during a display frame. Pixel values for the display may be modified to mitigate emitter artifacts.

Mitigating artifacts caused by an under-display light emitter

An electronic device may include a display and an optical sensor formed underneath the display. The electronic device may include a plurality of transparent windows that overlap the optical sensor. The resolution of the display panel may be reduced in some areas due to the presence of the transparent windows. To prevent a visible border between the reduced resolution areas of the display and full resolution areas of the display, uniformity compensation circuitry may be used to compensate pixel data. The uniformity compensation circuitry may output compensated pixel data for the display using one or more compensation maps that include compensation factors associated with pixel locations. The uniformity compensation circuitry may also use region-specific gamma look-up tables to apply different gamma curves to pixels in different regions of the display. The uniformity compensation circuitry may also be used to form a transition region between different regions of the display.

Devices with displays having transparent openings and uniformity correction

An electronic device may include a display. Control circuitry may operate the display at different frame rates such as 60 Hz, 80 Hz, and 120 Hz. The control circuitry may determine which frame rate to use based on a speed of animation on the display and based on a type of animation on the display. To mitigate the appearance of judder as the display frame rate changes, the control circuitry may implement techniques such as hysteresis (e.g., windows of tolerance around speed thresholds to ensure that the display frame rate does not change too frequently as a result of noise), speed thresholds that are based on a user perception study, consistent latency between touch input detection and corresponding display output across different frame rates (e.g., using a fixed touch scan rate that is independent of frame duration), and animation-specific speed thresholds for triggering frame rate changes.

Displays with variable frame rates

An electronic device may have a display layer for displaying images. An optical coupling layer having an input surface that receives light from the display panel may convey the light from the input surface to an output surface. The output surface may have different dimensions than the display layer and may have any desired shape. To account for the displacement of light between the active area and the outer surface of the optical coupling layer and to ensure the output image is perceived with the desired distortion, image data may be rendered for the output surface then modified to account for the distortion and displacement that will occur later when the image is transported by the optical coupling layer from the display active area to the output surface of the optical coupling layer. Image distortion control circuitry may modify the rendered image data based on a distortion map.

Distortion control in displays with optical coupling layers

An electronic device may include an electronic display having multiple pixels to display an image based on processed image data. Each of the pixels may include multiple sub-pixels. The electronic device may also include image processing circuitry to receive first image data for a sub-pixel of the and second image data for a group of sub-pixels surrounding the sub-pixel. The first image data may include a luminance value for the sub-pixel and the second image data may include luminance values for each sub-pixel of the group. The image processing circuitry may also determine a compensation value, to compensate the luminance value for lateral current leakage between the sub-pixel and the group of sub-pixels, based on the luminance value of the sub-pixel and the luminance values for each sub-pixel of the group of sub-pixels.

Pixel leakage and internal resistance compensation systems and methods

An electronic device may have a display. A protective display cover layer for the display may tend to dim pixels near the edge of the display. Control circuitry in the electronic device may boost luminance for pixels in an edge region of a displayed image relative to a center region of the image. This ensures that image brightness does not vary across the image. The control circuitry may include a graphics processing unit, a pixel pipeline implemented in a system-on-chip circuit block, and a display drive circuit block. Luminance compensation may be implemented in the system-on-chip block and/or in the display driver circuit block.

Electronic devices having displays with peripheral luminance compensation

An electronic device may be provided with an ambient light sensor, a display that displays image content, and control circuitry. The control circuitry may adjust a peak allowable brightness of the display based on an ambient light brightness and based on the image content being displayed. For example, the control circuitry may analyze frames of display data to determine an average pixel luminance level. Low average pixel luminance levels correspond to mostly dark image content, whereas high average pixel luminance levels correspond to mostly light image content. When an electronic device is outdoors and displaying mostly dark images with low average pixel luminance levels, the control circuitry may take advantage of the display's maximum achievable brightness to improve readability. When an electronic device is outdoors and displaying mostly light images with high average pixel luminance levels, the control circuitry may scale the maximum allowable brightness down to reduce power consumption.

Displays with content-dependent brightness adjustment

Techniques for implementing and/or operating an electronic device that includes a display panel, which displays an image and includes a first panel section implemented with a lower pixel resolution and a second panel section implemented with a higher pixel resolution, an optical sensor disposed behind the first panel section of the display panel, and image processing circuitry communicatively coupled to the display panel. The image processing circuitry receives source image data corresponding with the image, in which the source image data is indicative of target luminance of a display pixel, determines a pixel resolution surrounding the display pixel, processes the source image based at least in part on the pixel resolution surrounding the display pixel to facilitate determining display image data corresponding with the display pixel, and outputs the display image data to enable the display panel to display the image based on the display image data.

Multiple resolution section display panel systems and methods

An electronic device may include an electronic display having multiple pixels to display an image based on processed image data. Each of the pixels may include multiple sub-pixels. The electronic device may also include image processing circuitry to receive input image data, in a first color space, having luminance values for each of the sub-pixels. The circuitry may also map the input image data from the first color space to a second color space and apply a multi-dimensional lookup table, based on the input image data in the second color space, to generate compensated image data. The lookup table may receive the luminance values for each of the sub-pixels and output corrected luminance values compensated for an expected amount of current leakage between the sub-pixels. The circuitry may also inversely map the compensated image data from the second color space to the first color space to generate the processed image data.

Aspects of the subject technology relate to pulsed backlight operation for a display backlight. Backlight pulse patterns are provided that include steady state pulse patterns to be applied during operation of a liquid crystal display unit of the display at a corresponding frame rate. The backlight pulse patterns can be arranged to prevent visible artifacts such as flicker or strobing, particularly at or near a transition between LCD frame rates. In some scenarios, transition pulse patterns are provided.

Pulsed backlight systems and methods

An electronic device that includes processing circuitry configured to generate a frame of image data that has a frame duration is provided. The electronic device includes a display that has a plurality of pixels. Each of the plurality of pixels displays image data from the frame of image data for a pixel emission period that is less than the frame duration. A first pixel of a column of pixels of the plurality of pixels begins displaying the image data from the frame of image data at a first time for a first duration. A second pixel of the column of pixels that is adjacent to the first pixel begins displaying the image data from the frame of image data at a second time for a second duration. The first and second durations are equal to the pixel emission period. The second time begins after the first duration of time.

Interlaced or interleaved variable persistence displays

An electronic device is provided. The electronic device includes a display that is configured to show content that includes a plurality of frames. The plurality of frames includes a first frame that is associated with a pre-transition value. The plurality of frames also includes a second frame that is associated with a current frame value that corresponds to a first luminance. Additionally, the electronic device is configured to determine an overdriven current frame value corresponding to a second luminance that is greater than the first luminance. The electronic device is also configured to display the second frame using the overdriven current frame value.

Overdrive for electronic device displays

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Sunnyvale, CA, United States of America

Yingying Tang