Abstract:
Touch induced flicker for variable refresh rate (VRR) displays can be reduced by adjusting one or more voltages. Synchronization of touch sensing operations after an immediate exit can introduce flicker issues into the VRR display. In some examples, the touched induced flicker can be reduced or eliminated by tuning the voltage on a common electrode (Vcom) to a tuning point that reduces a maximum error below a threshold, irrespective of refresh rate. In some examples, touch induced flicker can be reduced or eliminated by monitoring average Vcom, and when the change in average Vcom exceeds a threshold, Vcom can be adjusted to counteract the change in average Vcom due to the variable refresh rate and/or immediate exit. In some examples, touch induced flicker can be reduced or eliminated by applying a direct current (DC) pedestal to pixel gate lines during touch sensing scans.
Abstract:
A display device may include a display having a pixels and a processor. The processor may receive image data, determine a digital offset value for a pixel based on a location of the pixel, such that the digital offset value compensates for one or more non-uniformity properties of the pixel. The processor may determine a scale factor associated with the pixel based on at least two of a luminance setting for the display, a driving mode of the display, and a gray level value for the pixel. The processor may then generate correction image data by applying the scale factor to the digital offset value, generate compensated image data based on the correction image data and the image data, and provide the compensated image data to the display.
Abstract:
A charge pump that can be configured to operate in a first mode and a second mode is disclosed. The charge pump can comprise a charging capacitor coupled to a first node and configured to transfer a first DC voltage to the first node. The charge pump can also comprise a first output node and a second output node coupled to the first node. During the first mode, the first output node can be configured to output a second DC voltage based on the first DC voltage, and the second output node can be configured to output a third DC voltage based on the first DC voltage. During the second mode, the first output node can be configured to output the second DC voltage, and the second output node can be configured to output an AC voltage, the AC voltage being offset by the third DC voltage.
Abstract:
A charge pump that can be configured to operate in a first mode and a second mode is disclosed. The charge pump can comprise a charging capacitor coupled to a first node and configured to transfer a first DC voltage to the first node. The charge pump can also comprise a first output node and a second output node coupled to the first node. During the first mode, the first output node can be configured to output a second DC voltage based on the first DC voltage, and the second output node can be configured to output a third DC voltage based on the first DC voltage. During the second mode, the first output node can be configured to output the second DC voltage, and the second output node can be configured to output an AC voltage, the AC voltage being offset by the third DC voltage.
Abstract:
Aspects of the subject technology relate to electronic devices with displays. A display may include display control circuitry including an internal oscillator and one or more counters. The counters may be used to calibrate a display line time to a system line time to ensure that each displayed frame is synchronized with received display data frames from system circuitry for the electronic device. The counters may include a first counter that maintains a current-row count during operation of a current row of display pixels during a current display frame and a second counter that maintains a current-frame count that indicates a number of counts accumulated during the current display frame. The current-row count and the current-frame count may be referenced to the system line time during operation of each pixel row to remove any errors accumulated during operation of the previous pixel rows.
Abstract:
This application relates to systems, methods, and apparatus for transitioning a display device between operating modes using a single dedicated pin of a circuit connected to the display device. The dedicated pin can receive a packet signal corresponding to an operating mode for the display device, and the circuit can thereafter cause the display device to transition into the desired operating mode in response to receiving the packet signal. The operating mode can be a low power on mode where an interface connected to the circuit is deactivated and at least some circuitry of the display device is throttled or powered off. The display device can be driven in an all black state while in the low power on mode, thereby allowing the display device to more quickly transition out of the low power on mode compared to when the display device is completely off.
Abstract:
One embodiment of an apparatus to control and sense a voltage through a single node can include a comparator to monitor single node voltage, a transistor to discharge voltage through the single node and control logic. The control logic can have at least two operational phases when actively controlling the voltage through the single node. In a first phase, the control logic can configure the comparator to determine if the single node voltage is greater than a reference voltage. In a second phase, the control logic can configure the transistor to discharge voltage through the single node when the comparator has previously indicated that the single node voltage is greater than a reference voltage. The control logic can alternatively execute first and second phases to discharge the voltage to a predetermined level.