Google Inc.

Apple Inc.

Meta Platforms Technologies, LLC

Facebook Technologies, LLC

Wonjae Choi

Sun-il Chang

Paolo Sacchetto

Hyunchul Kim

Cheng Kai Chen

Sang Young Youn

Zhiming Zhuang

Min Hyuk Choi

Shih Chang Chang

Enkhamgalan Dorjgotov

David W Lum

Fletcher R Rothkopf

Chaohao Wang

Chun-Yao Huang

Jason C Sauers

Sangmoo Choi

Cheonhong Kim

Graham Butler Myhre

Cheuk Chi Lo

Donghee Nam

Bennett S Wilburn

John Z Zhong

Steven Porter Hotelling

Wei Chen

Hung Sheng Lin

Qi Qi

Martin Paul Grunthaner

Lynn Richard Youngs

Masato Kuwabara

Yi Tao

Albert Lin

John W Kaehler

Daniel Solomon

Wenhao Qiao

Alexander Klement

Moon Jung Kim

Hopil Bae

Jie Won Ryu

Yingxuan Li

Sandro Hermann Pintz

Weijun Yao

Kyung Wook Kim

Szu-Hsien Lee

Byung Duk Yang

Injae Hwang

Hao-Lin Chiu

Kwang Soon Park

Xinyu Zhu

Patrick B Bennett

Geertjan Joordens

Bryce Bradford

Adam Adjiwibawa

Jaydeep Vijay Ranade

Altan N Yazar

Aaron Jacob Steyskal

Hynwoo Nho

PWM-frame rate misalignment is mitigated through implementation of a discrete variable refresh rate (VRR) scheme. A target frame rate is limited to a frame rate selected from only those frame rates that facilitate alignment of each frame period to a specified edge of a PWM cycle of a brightness control signal of a display panel. This alignment results in each frame period at the selected frame rate starting at a same point in a corresponding PWM cycle and ending at a same point in a corresponding PWM cycle to help ensure a constant effective duty cycle across each successive frame period, which in turn mitigates perception of flicker that otherwise would arise. Further, the discrete VRR scheme can employ a compensation mode for compensating for the delay in rendering or otherwise obtaining a frame for display so as to maintain a consistent duty cycle in the brightness control signal.

Variable refresh rate control using PWM-aligned frame periods

An electronic device such as a head-mounted device may have displays. The display may have regions of lower and higher resolution to reduce data bandwidth and power consumption for the display while preserving satisfactory image quality. Data lines may be shared by lower and higher resolution portions of a display or different portions of a display with different resolutions may be supplied with different numbers of data lines. Data line length may be varied in transition regions between lower resolution and higher resolution portions of a display to reduce visible discontinuities between the lower and higher resolution portions. The lower and higher resolution portions of the display may be dynamically adjusted using dynamically adjustable gate driver circuitry and dynamically adjustable data line driver circuitry.

Foveated display

A burn-in compensation method and a computing device configured for burn-in compensation is disclosed. The burn-in compensation can minimize or eliminate a burn-in of an OLED display having areas with different pixel densities. Each area of the OLED display may be divided into zones that include one or more pixels and a burn-in factor may be computed for the zones. A limiting burn-in factor may be determined from a limiting zone that exhibits the highest burn-in. Other zones with burn-in factors that area significantly different from the limiting burn-in factor can be adjusted so that the pixels in the adjusted zones can be driven to radiate similar light at a power similar to the liming zone. The burn-in compensation may be performed for each area and a transition region may be created between areas to minimize light artifacts after burn-in compensation.

Burn-in compensation for display

Methods, systems, and apparatus, including computer programs encoded on a computer storage medium, for dual color management for a multi-pixel density display. In one aspect, the method includes obtaining an image to be shown on a display, where the display includes both a first area that has a first pixel density and a second area that has a second pixel density that is less than the first pixel density, determining that a pixel with an initial value in the image will be displayed in the first area of the display (), in response to determining that a pixel with the initial value in the image will be displayed in the first area of the display, determining a remapped value for the pixel in the image based on the initial value and a lookup table for the first area (), and providing the remapped value for output on the display ().

Dual color management for a multi-pixel density display

Methods, systems, and apparatus, including computer programs encoded on a computer storage medium, for gamma lookup table compression based on dimensionality reduction. In one aspect, a method includes obtaining a selection of a particular display condition for a display panel from among different display conditions for the display panel, selecting, based on the selection of the particular display condition, a set of weights for a set of basis functions from among different sets of weights that correspond to the different display conditions for the display panel, determining a gamma lookup table for the particular display condition for the display panel based on the set of weights that were selected and the set of basis functions, and remapping an image to be output on the display panel based on the gamma lookup table for the particular display condition.

Gamma lookup table compression based on dimensionality reduction

Methods, systems, and apparatus, including computer programs encoded on a computer storage medium, for remapping for mixed dynamic range content. In one aspect, a method for remapping for mixed dynamic range content, the method includes obtaining an image to be displayed that includes both first dynamic range content and second dynamic range content, determining that the image includes first dynamic range content at a first pixel, determining a first remapped value for the first pixel based on a lookup table for first dynamic range content and an initial value for the first pixel, providing the first remapped value for the first pixel for display, determining that the image includes second dynamic range content at a second pixel, determining a second remapped value for the second pixel based on a second initial value for the second pixel, and providing the second remapped value for the second pixel for display.

Remapping for mixed dynamic range content

A frame generation subsystem renders a sequence of frames and a display control subsystem provides a brightness control signal configured to control a brightness of frames displayed at a display panel via pulse width modulation (PWM) of the brightness control signal and determines a deviation in a duty cycle of a first PWM period of the brightness control signal from a default duty cycle resulting from a delayed rendering of a frame. The display control subsystem adjusts a duty cycle of at least a second PWM period to compensate for the deviation in the duty cycle of the first PWM period. The resulting average duty cycle of the brightness control signal over the two frame periods is approximately equal to a default duty cycle and thereby mitigates viewable flicker resulting from the duty cycle change caused by the delayed rendering.

Display PWM duty cycle compensation for delayed rendering

Methods, systems, and apparatus, including computer programs encoded on a computer storage medium, for gamma lookup table compression. In one aspect, a method includes obtaining a gamma value for a pixel of an image to be shown on a display, determining a base gamma value based on a base lookup table that corresponds to a base display condition, determining a delta gamma value based on a delta lookup table that corresponds to a current display condition for the pixel, determining a remapped gamma value for the pixel based on a combination of the base gamma value and the delta gamma value, and providing the remapped gamma value to be shown on the display.

Gamma lookup table compression

A power supply unit adapts based on an image to be displayed by a display panel. The power supply unit includes a controller circuit for generating a power control signal, and a power supply circuit for generating one or more power supply voltages having a waveform based the power control signal. The controller circuit receives a set of configuration parameters from a display device and generates the power control signal based on the set of configuration parameters. The configuration parameters are stored in a look-up table of the display device.

Power management for global mode display panel illumination

A method of leakage-compensated global illumination comprises obtaining position data for at least one of a head or an eye of a user of a display system by an application processor, rendering image data for an image frame by the application processor based on the position data, modifying the image data to compensate for leakage associated with a global illumination by a display of the display system, and sending the image data to a display driver circuit of the display system for displaying the image frame on the display through the global illumination.

Switch leakage compensation for global illumination

A method including determining a maximum luminance location of a display based on a field of view of an eye of a user of the display, and driving a plurality of light sources in the display based on locations of the plurality of light sources with respect to the maximum luminance location of the display. The plurality of light sources is controlled to have different luminance levels in different display zones corresponding to different zones on the retina of the eye of the user. In some examples, the display zones of the display system that have higher luminance levels can be dynamically changed based on the field of view or the gaze direction of the eye of the user.

Methods of driving light sources in a near-eye display

Methods, systems, and apparatus, including computer programs encoded on computer storage media, for displaying an image on a flat panel display with an array of pixels. A method includes receiving image data including a grayscale value for each pixel; determining a grayscale delta for each pixel where the grayscale delta is a variation between the grayscale value for a given pixel addressable by a first scan line and the grayscale value for another pixel addressable by a scan line addressed prior to the first scan line; determining an aggregated grayscale delta for the first scan line; comparing a magnitude of the aggregated grayscale delta to a threshold value corresponding to a data signal that results in line crosstalk; modifying the image data when the magnitude of the aggregated grayscale delta equals or exceeds the threshold value, and displaying the image on the flat panel display using the modified image data.

Technique for reducing display crosstalk and systems implementing the same

Methods, systems, and apparatus, including computer programs encoded on computer storage media, for enabling a variable refresh rate on a display. One of the methods includes receiving, from a content presentation device, a first signal set to a first value; completing generation of first visual content; and after completing the generation of the first visual content, determining that the first signal is set to the first value and a second threshold duration of time has not expired; sending, to the content presentation device, the first visual content, wherein sending the first visual content causes the content presentation device to change the first signal from the first value to the second value; and after sending the first visual content, receiving, from the content presentation device, the first signal set to the second value.

Varying display refresh rate

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San Jose, CA, United States of America

Wonjae Choi