Apple Inc.

Injae Hwang

Hyunwoo Nho

Sun-il Chang

Jie Won Ryu

Junhua Tan

Shengkui Gao

Kingsuk Brahma

Hung Sheng Lin

Hyunsoo Kim

Shiping Shen

Jesse Aaron Richmond

Chaohao Wang

Rui Zhang

Myungjoon Choi

Wei Hsin Yao

Myung-Je Cho

Chin-Wei Lin

Paolo Sacchetto

Baris Cagdaser

Yifan Zhang

Yunhui Hou

Jiye Lee

Kavinaath Murugan

Yun Yu Wang

Tsung-Ting Tsai

Derek Keith Shaeffer

Mohammad Bagher Vahid Far

Weijun Yao

Mohammad Ali Jangda

Jiayi Jin

Howard H Tang

Majid Gharghi

Maofeng Yang

Mohammad Hajirostam

Chih-Wei Yeh

Changki Min

Rebecca Park

Jesun Kim

Weichuan Yao

Hopil Bae

Ting-Kuo Chang

Yafei Bi

Abbas Jamshidi Roudbari

Chieh-Wei Chen

Warren S Rieutort-Louis

Qing Li

Jun Li

Shyuan Yang

Wonjae Choi

David W Lum

David Andrew Doyle

Yi Qiao

Yuchi Che

Chuang Qian

Tae-Wook Koh

Yue Jack Chu

Graeme M Williams

Alex H Pai

Luigi Panseri

Yongjun Li

Bryce Bradford

Kiran S Pillai

Ricardo A Peterson

Adam Adjiwibawa

Mathew K Mathai

Hyuck-Jae Lee

James P Landry

Kyounghwan Kim

Salman Kabir

Bo-Ren Wang

Feng Wen

Hsin-Ying Chiu

Wenbing Hu

Junbo Wu

Toshiaki Sawada

Hynwoo Nho

An electronic device includes a display and a sensor underneath the display. The display has a full pixel density region and a reduced pixel density region. Compared to pixels in the full pixel density region, pixels in the reduced pixel density region can be controlled using overdriven power supply voltages, overdriven scan control signals, different initialization and reset voltages, and can include capacitors and transistors with different physical and electrical characteristics. Gate drivers provide scan signals to pixels in the full pixel density region, whereas overdrive buffers provide overdrive scan signals to pixels in the reduced pixel density region. The pixels in the full pixel density region and the pixels in the reduced pixel density region can be controlled using different black level or gamma settings for each color channel and can be adjusted physically to match luminance, color, as well as to mitigate differences in temperature and aging impact.

Displays having reduced pixel density region with localized tuning

An electronic device may include an electronic display including display pixels to display an image based on compensated image data. The electronic display may also include a stressed reference pixel to exhibit burn-in related aging in response to one or more stress sessions and a non-stressed reference pixel configured to not undergo the one or more stress sessions. Additionally, the electronic device may include image processing circuitry to determine a panel-specific aging profile based on a comparison between one or more properties of the stressed reference pixel and the one or more properties of the non-stressed reference pixel. The image processing circuitry may also generate one or more gain maps based on the panel-specific aging profile and generate the compensated image data by applying the one or more gain maps to input image data.

Reference pixel stressing for burn-in compensation systems and methods

External compensation of display panels may employ measurement or sensing circuitry configured to measure the output of a pixel and compensate for variations. Due to effects from the sensing circuitry, a mismatch between a target current and the actual current in the pixel may occur. Systems and methods that compensate for the effects from sensing circuitry and reduce or mitigate the mismatch are described. Systems and methods described herein include compensation circuitry that is capable of employing correction factors to compensate for the effects due to the presence of sensing circuitry. Methods for determining the correction factor are also described.

External compensation for displays using sensing and emission differences

A current-voltage (IV) relationship of a pixel having a diode is initially determined. A first voltage is determined that does not cause the diode to emit light, and a first current across the diode is sensed by applying the first voltage. A predetermined current is determined based on the first voltage and the IV relationship. A ratio is determined based on the first current, a target current, and the predetermined current. A ratio voltage is determined by applying the ratio to a predetermined target voltage. If the first current is less than the predetermined current, then the ratio voltage is applied to supply a target current to the diode. If the first current is greater than the predetermined current, then a second voltage is determined by averaging the first test voltage and the ratio voltage, and the second voltage is applied to supply the target current to the diode.

Display compensation using current sensing across a diode without user detection

An electronic device comprises a controller. The controller is configured to provide a first signal to a display of the electronic device to turn off the display. The controller is also configured to provide a second signal to the display to alter a gate source voltage of a drive transistor coupled to a light emitting diode (LED) of a pixel of the display while the display is turned off.

Device and method for panel conditioning

Electronic devices and methods for compensating for aging or other effects in a display during a non-transmitting state (off state) of the display. Sensing may include emissive element sensing of the display and/or thin film transistor sensing of the display. Compensating for the effects may preserve or increase a uniformity of transmission of the display.

Display off-time sensing

Systems and methods are presently disclosed that compensate for temperature-based parasitic capacitance variation of a pixel of a display by causing a driver transistor of the pixel to enter an ohmic or linear region. A lookup table is generated based on temperatures at the pixel, diode voltages, and target diode currents or luminances at a diode of the pixel. A correction voltage is determined based on a target diode current or luminance, a temperature at the pixel, and the lookup table. A data voltage is applied corresponding to the target diode current or luminance and the correction voltage to the driver transistor.

Systems and methods for temperature-based parasitic capacitance variation compensation

An electronic display having pixels and control circuitry to drive the pixels to display image data even during relatively long presentation times without visual artifacts, such as flicker, are provided. The control circuitry may cause the pixel to perform a threshold voltage sampling and pixel programming phase to store image data for the pixel while accounting for a first threshold voltage of the first transistor. Afterward, an on-bias stress phase may cause a threshold voltage of the first transistor of the plurality of transistors to reach a second threshold voltage. Following the on-bias stress phase, a first emission phase may cause the light-emitting diode to emit light in accordance with the image data, and subsequent on-bias stress phases and subsequent emission phases for the duration of the presentation time may take place without a visible flicker artifact.

Electronic display visual artifact mitigation

A system may include an electronic display panel having multiple pixels for depicting image data and processing circuitry that may receive a first error value representative of a first difference between a first electrical signal measured at a first pixel of the multiple pixels and an expected electrical signal for the first pixel. The first electrical signal may be based on a test signal transmitted to the first pixel and the expected electrical signal may correspond to an expected response of the first pixel based on the test signal. The processing circuitry may filter the first error value to generate a first compensated error value and may filter the first error value based on the first compensated error value to generate a second compensated error value, where the second compensated error value may filter one or more effects of spatial crosstalk between one or more pixels near the first pixel.

Spatially leaking temporal integrator for pixel compensation

An electronic device comprises an electronic display having an active area having a pixel. The electronic device also comprises processing circuitry configured to receive image data to send to the pixel and adjust the image data to generate corrected image data based at least in part on a stored correction value for the pixel. The processing circuitry also is configured to generate a test data to send to the pixel subsequent to sending corrected image data to the pixel, wherein the test data is selected based upon a comparison of at least one aspect of the corrected image data with a threshold value.

Sensing considering image

An apparatus receives current image frame data and data relating to at least one previous image frame for an electronic display. One or more parameters related to hysteresis of transistors in the electronic display are sensed. A correlation device, such as a look-up table, receives the sensed parameter or parameters and the data relating to one or more image frames, and uses this information, at least in part, to output an appropriate compensation signal for the current image frame data. The compensated current image frame data may then be supplied to the electronic display to reduce or eliminate the effects of hysteresis on the displayed image.

Active sensing and compensation for display panel hysteresis

A display device may include a plurality of pixels configured to display image data on a display. The display device may also include a circuit that measures a first current associated with a light-emitting diode (LED) of a pixel of the plurality of pixels in response to the circuit receiving a first data voltage. The circuit may also measure a second current associated with the LED of the pixel of the plurality of pixels in response to the circuit receiving a second data voltage. The circuit may then determine a voltage associated with the LED based at least in part on the first current and the second current.

Systems and methods for sensing pixel voltages

A device may include a photosensitive transistor and a light-emitting diode. The light-emitting diode may include an anode. The anode may include a first portion having a first thickness and a second portion having a second thickness, wherein the second thickness is less than the first thickness. The device may also include driving circuitry that receives a data signal and causes light to emit from the light-emitting diode in response to the data signal. The photosensitive transistor may generate an electrical signal in response to light emitted from the light-emitting diode during the light emission.

Compensation using optical feedback for self-emissive pixel

A system may include a display panel that includes number of pixels that display image data on a display. The system may also include a circuit that measures a voltage associated with a light-emitting diode (LED) of a pixel of the number of pixels in response to the LED receiving a current. In addition to the circuit, the system may employ data processing circuitry that may generate a calibrated prediction model based at least in part on the voltage and the current, such that the calibrated prediction model predicts a change in voltage performance of the LED as the LED ages.

Systems and methods for compensating pixel voltages

An electronic display system may include a display panel used to display an image through emitting light. The electronic display system may also include processing circuitry that receives indication of an image to be displayed on the display panel and generates one or more signals to communicate the image on the display panel. The processing circuitry may compensate for non-uniformities in light emission between pixels of the display due to current-voltage non-uniformities.

External compensation for LTPO pixel for OLED display

Growing community of inventors

Cupertino, CA, United States of America

Injae Hwang