Abstract:
Displaying an image on a display screen is provided by periodically changing the scanning order in which rows of sub-pixels of the display screen are scanned. One scanning order can be selected to scan the rows in the update of a first image frame of the display, and then a different scanning order can be selected to scan the rows in the update of a second image frame. Particular scanning orders can be selected in order to reduce or eliminate the appearance of visual artifacts by changing the location of the visual artifacts across multiple image frames. For example, different scanning orders that result in visual artifacts at different positions on the display screen can be used, and the selection of scanning order can periodically change among the different scanning orders such that the position of the visual artifacts changes periodically during the updating of multiple image frames.
Abstract:
Displays with integrated touch sensing circuitry are provided. An integrated touch screen can include multi-function circuit elements that form part of the display circuitry of the display system that generates an image on the display, and also form part of the touch sensing circuitry of a touch sensing system that senses one or more touches on or near the display. The multi-function circuit elements can be, for example, capacitors in display pixels of an LCD that are configured to operate as display circuitry in the display system, and that may also be configured to operate as touch circuitry of the touch sensing system. For example, one or more circuit elements of the display pixel stackup can form a conductive portion of the touch sensing system, such as a charge collector, which can be operated with switches and conductive lines to sense touch.
Abstract:
Negative pixel compensation in a touch sensitive device is disclosed. The device can compensate for a negative pixel effect in touch signal outputs due to poor grounding of an object touching the device. To do so, the device can switch to a configuration to measure the grounding condition of the touching object and use the measurement to compensate the touch output values from the device accordingly. In the switched configuration, a first set of lines of the device can be switched between a coupling to a stimulation signal input to drive the device, a coupling to a capacitance signal output to output a signal indicative of the object's grounding condition, and a coupling to ground. A second set of lines of the device can be coupled to a touch signal output to output a signal indicative of the object's touch at the device.
Abstract:
A touch controller for flexible scanning operation is disclosed. The touch controller can include circuitry configured to perform coarse detection scans, select a fine scan type based on results from the coarse detection scans, and perform a fine scan corresponding to the selected fine scan type. A fine mutual capacitance scan can be performed when conditions corresponding to a poorly grounded or ungrounded object or user are detected based on the coarse detection scans. A fine fully-bootstrapped self-capacitance scan can be performed when conditions corresponding to a well-grounded object or user are detected based on the coarse detection scans. A touch processor can be configured to sense touch events from the fine scan.
Abstract:
A touch controller that can configure touch circuitry according to a scan plan, which can define a sequence of scan events to be performed on a touch panel is disclosed. The touch controller can include a configurable transmit section to generate stimulation signals to drive the panel, a configurable receive section to receive and process touch signals from the panel, and a configurable memory to store the touch signals. The touch controller can also include a programmable scan engine to configure the transmit section, the receive section, and the memory according to the scan plan. The touch controller advantageously provides more robust and flexible touch circuitry to handle various types of touch events at the panel. An active stylus that can generate stimulation signals that can be detected by the touch controller during various touch events at the panel is also disclosed.
Abstract:
Styluses capable of generating stylus stimulation signals and touch sensitive devices capable of receiving stylus stimulation signals are disclosed. In one example, a stylus can receive a stimulation signal from a touch sensor of a touch sensitive device and generate a stylus stimulation signal by changing an amplitude or frequency of the received stimulation signal. The stylus can transmit the stylus stimulation signal back into the touch sensor of the touch sensitive device. The touch sensor can generate a touch signal based on the device's own stimulation signals and the stylus stimulation signal. The touch sensitive device can process the touch signal to determine a location of the stylus on the touch sensor. The stylus can include a force sensor to detect an amount of force applied to a tip of the stylus. The stylus stimulation signal can be modulated based on the force detected by the force sensor.
Abstract:
With respect to liquid crystal display inversion schemes, a large change in voltage on a data line can affect the voltages on adjacent floating data lines due to capacitive coupling between data lines. The change in voltage on these floating data lines can be increased when the application of voltage to the data line occurs after a toggling operation of the Vcom, i.e., when a voltage applied to the Vcom changes the voltage on the Vcom from one polarity to an opposite polarity. Various embodiments of the present disclosure serve to eliminate or reduce the effects of Vcom voltage toggling on data line voltages by applying a voltage (e.g., a fixed voltage) to the data lines while the voltage on Vcom toggles.
Abstract:
Electrical shield line systems are provided for openings (829) between common electrodes (813, 815) near data lines (807) of display and touch screens (800). Some displays, including touch screens, can include multiple common electrodes (Vcom, 813, 815) that can have openings (829) between individual Vcoms (813, 815). Some display screens can have an open slit (829) between two adjacent edges of Vcom (813, 815). Openings (829) in Vcom (813, 815) can allow an electric field (831) to extend from a data line (807) through the Vcom layer (813, 815). A shield (833) can be disposed over the Vcom opening (829) to help reduce or eliminate an electric field from affecting a pixel material, such as liquid crystal (827). The shield (833) can be connected to a potential such that electric field is generated substantially between the shield (833) and the data line (807) to reduce or eliminate electric fields reaching the liquid crystal (827).
Abstract:
A touch sensor panel is disclosed. In some examples, the touch sensor panel comprises a plurality of touch node electrodes. In some examples, the touch sensor panel comprises a touch controller configured to drive and sense the plurality of touch node electrodes in a fully bootstrapped configuration to obtain a fully bootstrapped touch image, drive and sense the plurality of touch node electrodes in a second configuration, different from the fully bootstrapped configuration, to obtain a second touch image, the second touch image including an effect of water on the touch sensor panel, and determine a final touch image based on the fully bootstrapped touch image and the second touch image, the final touch image not including the effect of the water on the touch sensor panel. In some examples, the second configuration comprises a mutual capacitance configuration. In some examples, the second configuration comprises a partially bootstrapped configuration.