Google Inc.

Motorola Corporation

Motorola Mobility LLC

Google Technology Holdings LLC

Chien-Hui Wen

Hsin-Yu Chen

Ken Foo

Sang Young Youn

John W Kaehler

Zhiming Zhuang

Hyunchul Kim

Yichi Chen

Sangmoo Choi

Kevin W Johnson

Sen Yang

Mark Frederick Valentine

Dongxue Wang

Jyothi Karri

Daniel Solomon

Alexander Klement

David M Emig

Xiaoping Bai

Kevin H Dao

Methods, systems, and apparatus, including computer programs encoded on computer storage media, for brightness control for under-display fingerprint sensor are disclosed. A method includes receiving, at a computing device, an indication to activate an under-display sensor that is located underneath a display of the computing device; activating a collection of LEDs of the display to provide illumination for the under-display sensor, including activating an LED in the collection of LEDs by: establishing, by drive circuitry of the LED, a first overdriven voltage across an LED-driving transistor that is arranged to energize the LED; establishing a second overdriven voltage across the LED-driving transistor; and establishing a steady state voltage across the LED-driving transistor; and activating the under-display sensor by reading a signal from the under-display sensor once the collection of LEDs has activated, including once the steady state voltage has been programmed across the LED-driving transistor.

Brightness control for under-display sensor

An example method includes measuring, from a device having a display panel, a plurality of luminance values for a plurality of pixels located along a cross-section of the display panel. The method includes selecting, based on the measured luminance values, a target luminance value. The method includes determining a luminance compensation profile for the input gray level at the given refresh rate. The luminance compensation profile comprises ratios of the measured plurality of luminance values to the target luminance value. The method includes storing, at the device, the luminance compensation profile. Subsequent to the storing, the device is configured to adjust input display data using the luminance compensation profile for an input gray level when the display panel is providing a display. The luminance compensation profile maintains a color uniformity of the display.

Modified demura algorithm for display panels

A method involves measuring, for an optical property of the display panel for an input gray level and at a first refresh rate, first and second values at respective first and second ambient brightness levels. The method also involves determining a compensation factor for the input gray level at the first refresh rate. The method further involves determining a modified gamma value at a second refresh rate, wherein the modified gamma value reduces a perceived optical defect of the display panel when operating at the second refresh rate by maintaining a consistent delta difference in values for the optical property between the first and second refresh rates at different ambient brightness levels. The method additionally involves storing the modified gamma value, where the device is configured to adjust input display data using the modified gamma value when transitioning from the first refresh rate to the second refresh rate.

Recalibrating gamma curves for seamless transitions in multiple display refresh rates

This document describes systems and techniques directed at expediting fingerprint authentication via variable refresh rate control and display luminance compensation. In aspects, a computing device having an under-display fingerprint sensor (UDFPS) and a touch-sensitive display includes a biometric authentication manager. Upon detecting at least one finger at or near the touch-sensitive display, the biometric authentication manager implements variable display refresh rates and selectively adjusts luminance settings for a high-luminance region of the touch-sensitive display for predetermined intervals. In so doing, at least one finger can be well-illuminated during UDFPS image capturing, facilitating UDFPS sensing and expediting fingerprint authentication.

Expediting fingerprint authentication via variable refresh rate control and display luminance compensation

An example method includes determining, for a device having a display component configured to operate at multiple brightness levels and for a range of DBVs, a gamma value offset to a default gamma value at the second brightness level. The method includes determining, for a tap point representative of the range, a brightness value offset to a default brightness value at the second brightness level. The method includes storing the gamma value offset and the brightness value offset. Subsequent to the storing, the device is configured to transition, in response to a fingerprint authentication triggering event, the display component from a first brightness level to a second brightness level by: overriding a default gamma value based on the gamma value offset, and displaying a portion of the display component by applying a value offset to a default brightness value at the second brightness level based on the brightness value offset.

Smart algorithm for seamless transition with under display fingerprint sensors

An example device includes a display component that is configured to operate at a first refresh rate or a second refresh rate. The device also includes one or more processors operable to perform operations. The operations include identifying a rate change triggering event while the display component is operating at the first refresh rate. The operations further include determining a current brightness value of the display component. The operations also include determining, based on an environmental state measurement associated with an environment around the device, a threshold brightness value. The operations additionally include transitioning the display component from the first refresh rate to the second refresh rate m response to identifying the rate change triggering event if the current brightness value of the display component meets or exceeds the threshold brightness value.

Seamless transition for multiple display refresh rates

In general, the subject matter described in this disclosure can be embodied in methods, systems, and program products for presenting display content on a display of a computing system. A method includes selecting, from a collection of luminance profiles that are each configured to reduce brightness of the display content in different manners, a first luminance profile based on the current display brightness setting, the first luminance profile specifying a first amount of brightness reduction to a peripheral portion of the display content and a first gradient of brightness reduction for a portion of the display content between the peripheral portion of the display content and a center portion of the display content; applying the first luminance profile to the display content to modify the display content by reducing a brightness of the display content according to the first luminance profile; and presenting the display content on the display.

Variable brightness dimming of display peripherals

A method for calibrating input display data for multiple display refresh rates comprises measuring () an optical property of a display panel for an input gray level at a first refresh rate, measuring () the optical property for a plurality of candidate gray levels at a second refresh rate, selecting (), based on the measured optical properties of the display panel, a corresponding gray level for the input gray level, wherein the corresponding gray level is selected from the plurality of candidate gray levels and storing (), at the device, the corresponding gray level for the input gray level, wherein subsequent to the storing, the device is configured to adjust input display data using the corresponding gray level for the input gray level when the display panel is transitioning from the first refresh rate to the second refresh rate.

Calibrating input display data for seamless transitions in multiple display refresh rates

A non-transitory computer-readable storage medium can include instructions stored thereon that, when executed by at least one processor, are configured to cause a computing device to determine, in response to a change in a refresh rate of a display, an encoded intensity of at least a portion of an image presented by the display, determine that the encoded intensity is within a predetermined range, and based on determining that the encoded intensity is within the predetermined range, adjust an intensity of a signal for the portion of the image.

Maintaining luminance when refresh rate changes

Techniques and apparatuses are described that perform frequency compensation for a display. In aspects, a first uniformity of multiple regions of the display can be measured at a reference frequency. The display can then be driven at a second frequency and a second uniformity of the multiple regions of the display can be measured. The differences between the first and second uniformity can then be used to generate a compensation mask. XYZ domain data from the first and second uniformity measurements can be used to generate a color model characterization. The color model characterization can be used to convert the XYZ domain data into RGB data when the display is driven at the second frequency to compensate for the differences in uniformity across the multiple regions of the display.

Frequency compensation for a display

A method may include measuring, from a device having a display panel configured to operate at a first refresh rate or a second refresh rate, a difference in luminance of the display panel between the first refresh rate and the second refresh rate for an input gray level. The method may also include applying, based on the measured difference in luminance, a value offset to a default gamma value used by the device for the input gray level when the display panel is operating at the second refresh rate, thereby generating a new gamma value. The method may further include storing, at the device, the new gamma value, where subsequent to the storing, the device is configured to override the default gamma value for the input gray level with the new gamma value when the display panel is operating at the second refresh rate.

Predictive gamma algorithm for multiple display refresh rates

An example device includes a display component that is configured to operate at a first brightness level or a second brightness level. The device also includes one or more processors operable to perform operations. The operations include detecting, by the display component and while the display component is operating at the first brightness level, a fingerprint authentication triggering event. The operations further include determining, based on the fingerprint authentication triggering event, a first portion of the graphical user interface to operate at the second brightness level. The operations also include transitioning the display component from the first brightness level to the second brightness level. The operations additionally include displaying a second portion of the display component based on applying, to the second portion, one of: (1) the first brightness level, or (2) a value offset to a gray level for the second brightness level.

Seamless transition for multiple display brightness modes

This document describes systems and techniques for spatially and temporally dynamic illumination for fingerprint authentication. In aspects, a method is disclosed that involves receiving user input at a display of an electronic device, initiating biometric authentication, and instructing a display-driver integrated circuit (DDIC) to implement a local high-brightness mode, which causes a predetermined portion of the display to increase in luminance to a target luminance for at least a first interval and a second interval. The DDIC is also instructed to cause a variable portion of the display to increase in luminance for the first interval and, at the expiration of the first interval, decrease luminance. During the first and/or second interval, an under-display fingerprint sensor captures one or more images. It is then determined, based on analysis of the one or more images, whether the user input is indicative of an authorized user.

Growing community of inventors

Vernon Hills, IL, United States of America

Chien-Hui Wen