Apple Inc.

Tobias Jung

Marc Albrecht

Sean C Chang

Wei Hsin Yao

Pierre-Yves Emelie

Duane M Petrovich

Chengrui Le

Chaohao Wang

Mingxia Gu

Nicolas P Bonnier

David S Zalatimo

Teun R Baar

Lingyu Hong

Manev Luthra

Ameya Y Joshi

Paul Stephen Drzaic

Jun Qi

Hung Sheng Lin

Hyunwoo Nho

Kingsuk Brahma

Ian C Hendry

Ramin Samadani

Jie Won Ryu

Sun-il Chang

Mohammad Bagher Vahid Far

Jiaying Wu

Sheng Zhang

Sandro Hermann Pintz

Junhua Tan

Jesse Aaron Richmond

Nathaniel C Begeman

Xiaokai Li

Yifan Zhang

Tae-Wook Koh

Zhendong Hong

Abdeslam Hafidi

Chih-Wei Yeh

Xiang Fang

Suraj P Gorkhali

Yi-Pai Huang

Shuang Wang

Fang-Cheng Lin

Kevin W Sliech

Nachum M Kanovsky

Mahnaz Mohammadi

Jun Miao

Mohammad Tofighi

Chen Zheng

José Antonio Dominguez-Caballero

Yansong Liu

He Li

Meng Cao

Jiulong Shan

Shuo Han

Andrei E Toma

A display may have a pixel array such as a liquid crystal pixel array. The pixel array may be illuminated by a backlight unit that includes an array of light-emitting diodes (LEDs). The backlight unit may determine the type of content in the image data. The backlight unit may decide to prioritize either mitigating halo or mitigating clipping based on the type of content. The determination of the type of content in the image data may be used to determine the brightness values for the LEDs in the LED array. If the content is determined to be a first type of content, at least one given LED in the LED array may have a different brightness value than if the content is determined to be a second, different type of content. Classifying content in the image data may be useful in optimizing visible artifacts such as visible halo and clipping.

Using content type to select brightness in direct-lit backlight units

An electronic device may include a display having an array of pixels and a backlight that provides backlight illumination for the array of pixels. The backlight may be a direct-lit backlight with a two-dimensional array of light-emitting diodes operable in a local dimming scheme. The electronic device may include control circuitry that provides pixel signals to the array of pixels and backlight signals to the backlight. The control circuitry may adjust the pixel signals and the backlight signals to compensate for brightness and color non-uniformity in the backlight. To compensate for image-dependent backlight non-uniformity, the control circuitry may simulate artificial backlight data based on the target image to be displayed and stored point spread information. To compensate for white-point-dependent backlight non-uniformity, the control circuitry may use measured actual backlight data that describes color variations across the backlight for a given target white point.

Displays with reduced color non-uniformity

Systems and methods are provided for displaying augmented reality image content perceived as being overlaid on background image content viewed through a light-transmissive viewing surface. Image processing circuitry may receive input augmented reality image data corresponding with a pixel position on the display panel, determine a perceived background brightness metric indicative of background brightness level at the pixel position based at least in part on captured background image data and an ambient lighting metric, determine a target tone mapping based at least in part on the perceived background brightness metric, and determine display augmented reality image data to be used by a display panel to display the augmented reality image content least in part by applying the target tone mapping to the input augmented reality image data.

Augmented reality local tone mapping for light-transmissive display panel systems and methods

Systems, methods, and devices are provided to reduce a likelihood of image burn-in on an electronic display. Such an electronic device may include image processing circuitry and an electronic display. The image processing circuitry may receive image data and analyze the image data for risk of image burn-in and, based at least in part on the analysis of the image data, reduce a risk of image burn-in at least in part by reducing a local maximum pixel luminance value in at least one of a plurality of regions of the image data over time or by reducing a dynamic range headroom of the image data. The electronic display may display the image data with a reduced risk of image burn-in on the pixels of the electronic display.

Electronic display burn-in detection and mitigation

A display may have a pixel array such as a liquid crystal pixel array. The pixel array may be illuminated by a backlight unit that includes an array of light-emitting diodes. A backlight brightness selection circuit may select brightness values for the light-emitting diodes. The backlight brightness selection circuit may select the brightness values based on image data, based on brightness values used in previous image frames, based on device information, and/or based on sensor information. The backlight brightness selection circuit may select the backlight brightness levels to mitigate visible artifacts such as flickering and halo. The backlight levels selected by the backlight brightness selection may be modified by a power consumption compensation circuit. The power consumption compensation circuit may estimate the amount of power consumption required to operate the backlight using the target brightness levels and may modify the target brightness levels to meet maximum power consumption requirements.

Displays with adjustable direct-lit backlight units and adaptive processing

An electronic device may be provided with a display. A content generator may generate frames of image data to be displayed on the display. Control circuitry in the electronic device may be used in implementing a tone mapping engine. The tone mapping engine may display content from the content generator on the display in accordance with a content-luminance-to-display luminance mapping. The content-luminance-to-display-luminance mapping is characterized by tone mapping parameters such as a black level, a reference white level, and a specular white level. The tone mapping engine may adjust the tone mapping parameters based on ambient light levels, user brightness settings, content statistics, and display characteristics.

Electronic devices with tone mapping engines

Systems, methods, and computer readable media to improve the operation of display systems are disclosed. In general, techniques are disclosed for dynamically adjusting backlight elements based on image content. More particularly, a backlight element's intensity may be targeted for boosting (i.e., increasing) based on content of the backlight element's corresponding image region, where after a check may be made to determine if the proposed increase is likely to risk generation of a halo. If the proposed intensity increase would risk a halo, the backlight element's proposed intensity may be dimmed. Repeating the boost/dim cycle in an iterative fashion permits an image to be displayed with brighter highlights and deeper blacks.

Locally adaptive backlight control

Display with adjustable direct-lit backlight units

Displays with adjustable direct-lit backlight units and power consumption compensation

Systems, methods, and computer readable media to improve the operation of display systems are described herein. In general, techniques are disclosed for ambient and content adaptive local tone mapping operations that improve display readability under bright ambient light conditions. More particularly, techniques disclosed herein improve contrast and brightness of dark image content while preserving bright areas. The disclosed architecture and operational methodologies generate high contrast images (e.g., amplifying dark regions while preserving bright content), preserve uniform backgrounds (e.g., static background pixels), are stabile in the face of local and global histogram changes (e.g., background not affected by small moving objects such as a mouse pointer), and provide near seamless fade-in and fad-out transitions.

Ambient and content adaptive pixel manipulation

Displays with adjustable direct-lit backlight units

Aspects of the subject technology relate to display circuitry including pixel overdrive circuitry. The pixel overdrive circuitry includes a compression engine that compresses a previous display frame, for storage and comparison to a current display frame without compression or decompression of the current display frame. The compression engine compresses the previous frame in such a way that the maximum compression error is always known and can be used to determine whether to perform overdrive operations for the current frame without compressing and decompressing the current display frame. The compression engine selects gradient encoding or decimation encoding for the compression of the previous display frame and can perform successive decimation operations within the gradient encoding operations to help reduce the size of the compressed previous frame while maintaining the quality of the ultimate overdriven current frame.

Display pixel overdrive systems and methods

Devices, storage media, and methods for compensating for aging and temperature variations using dual-loop compensation are provided. The compensating for temperature and aging variations of one or more pixels of the display using a coarse scan loop updated at a faster rate. Compensation also includes compensating for aging variations of the one or more pixels of the display using a fine scan loop updated at a slower rate.

Dual-loop display sensing for compensation

Methods, systems, and devices for improving contrast, dynamic range, and power consumption of a backlight in a display are provided. By way of example, a method includes receiving image data to be displayed on pixels of a display panel, generating a global histogram of the image data, generating a plurality of thresholds based on the global histogram, and defining a first threshold and a second threshold of the plurality of thresholds as local thresholds based on the global histogram and a local histogram. The first threshold and the second threshold are generated according to a local tone mapping function. The method further includes adjusting a luminance of one or more of pixels of the display panel based at least in part on the first threshold and the second threshold.

Devices and methods of adaptive dimming using local tone mapping

Growing community of inventors

San Francisco, CA, United States of America

Tobias Jung