Apple Inc.

Ionut A Mirel

Mahesh B Chappalli

Wei Hsin Yao

Hopil Bae

Hyunwoo Nho

Kingsuk Brahma

Jie Won Ryu

Sun-il Chang

Mahdi Farrokh Baroughi

Wei Xiong

Hyunsoo Kim

Young Don Bae

Saif Choudhary

Haitao Li

Yao Shi

Sunmin Jang

Hari P Paudel

Akshay Bhat

Maximillian C Bruggeman

Patrick R Cruce

Yan Guan

Gautam Agrawal

Ruicong Chen

Nicolas Le Dortz

An electronic display includes an ambient light sensor (ALS) located beneath an active area to sense ambient light above the active area. The ALS is synchronized with blanking periods of a display pixel on the active area. An emission-off scale factor is calculated based on an emission profile of the display pixel when the display pixel is turned off. The emission-off scale factor is used with display content to calculate a crosstalk compensation for the ALS.

Compensation for crosstalk between electronic display and ambient light sensor

Embodiments herein provide various apparatuses and techniques to efficiently mitigate front-of-screen (FoS) artifacts that may occur due to voltage fluctuations due to alternating current (AC) or direct current (DC) mechanisms that may occur in a variety of pixel types. In one embodiment, emission profile awareness circuitry may be implemented to mitigate for FoS artifacts due to DC mechanisms. Two-dimensional (2D) digital compensation circuitry may address the DC portion of the voltage fluctuations by accounting for an emission profile applied to content displayed on an electronic display. In some embodiments, the 2D digital compensation circuitry may compensate for the AC portion of the voltage fluctuations by duplicating the AC voltage fluctuations via voltage error subtraction circuitry and voltage error accumulation circuitry.

Feedforward compensation of high-luminance banding Mura compensation

To mitigate undesirable outcomes due to crosstalk in an ambient light sensor reading resulting from light emission from an electronic display, statistics may be gathered to determine and compensate for the crosstalk. For example, the ambient light sensor may detect ambient light levels while the electronic display is temporarily paused to reduce or eliminate crosstalk between the light produced by the electronic display and the ambient light sensor. However, the ambient light sensor may retain charge from a previous light emission, creating back-emission crosstalk. The ratio of back-emission to front-emission (e.g., present light emission) may not be linear, and the degree of nonlinearity may vary with pixel value, color component, display brightness, temperature, and so on. As the ambient light sensor is affected by back-emission, compensation for the nonlinearity between the front-emission and the back-emission may be obtained to estimate the crosstalk induced on the ambient light sensor.

Systems and methods for crosstalk mitigation between ambient light sensor and electronic display

To reduce image artifacts and non-uniformity associated with a display pixel of an electronic display, processing circuity may adjust a luminance value corresponding to a display pixel according to a per-pixel gain mask, a per-pixel anode mask, or both. To further correct for the non-uniformity, the processing circuitry may convert the luminance value to a digital code based on a curve associated with an anode on which the display pixel is located.

Display pixel non-uniformity compensation

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Cupertino, CA, United States of America

Ionut A Mirel