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:
Reducing or eliminating the effects of noise that can be generated by a power system of a touch screen device, such as a gate line voltage system that applies voltage to gate lines of the touch screen, is provided. In one example, a power supply, such as a charge pump, can be disabled during active touch sensing, such that noise from the charge pump is not generated during touch sensing. In some examples, a voltage regulator can help to maintain the gate voltage level at or above a desired threshold. In some cases, noise entering the touch sensing system can have a lasting effect on noise- sensitive components, even after the noise source is disabled. In these cases, a post-noise stabilizing system can be included to stabilize, reset, etc., noise-sensitive components of the touch sensing system, which can help to reduce or eliminate the lasting effect of noise.
Abstract:
A gate driver circuit for switching gate line voltage supplies between display and touch modes is disclosed. The circuit can include one or more switches configured to switch one or more gate lines of an integrated touch sensitive display between a display mode and a touch mode. During touch mode, the circuit can be configured to switch the gate lines to connect to a more stable voltage supply. The circuit can also be configured to reduce or eliminate interference from the display circuitry to the touch circuitry that could affect touch sensing. During display mode, the circuit can be configured to switch the gate lines to connect to a fluctuating voltage supply.
Abstract:
A touch input device configured to detect stylus signals generated by an external stylus is provided. The touch input device includes a plurality of stylus signal detectors that receive at its input a combination of stylus receive channels that are combined in a manner to minimize noise while at the same time keeping the stylus signal strength uniform independent of the position of the stylus on the device.
Abstract:
Operating touch screens by applying more than one voltage modes, including a first voltage mode corresponding to a display phase (1000a) and a second voltage mode corresponding to a touch sensing phase (1000b), is provided. An integrated touch screen device (220) can include a multi-mode power system that can select a first voltage mode corresponding a display phase (1000a) and a second voltage mode corresponding to a touch sensing phase (1000b). Each of one or more voltages can be applied to the touch screen (220) at the corresponding first voltage level during the updating of the image. A touch sensing system can sense touch during a touch sensing phase (1000b). Each of one or more voltages can be applied to the touch screen (220) at the corresponding second voltage level during the sensing of touch.
Abstract:
A touch sensitive device having circuitry to compensate for crosstalk from the device display to the device touch sensor panel is disclosed. The crosstalk compensation circuitry can include a downsampler and a crosstalk compensator. The downsampler can downsample a display image to a manageable size for transmission and processing and can then send the downsampled image to the crosstalk compensator so as to provide information about the display operation that can be used to estimate the expected amount of crosstalk caused by the display. The crosstalk compensator can estimate the amount of crosstalk based on the downsampled image and can then compensate a touch image captured by the touch sensor panel for the estimated amount, the touch image being indicative of a touch or hover event at the panel.
Abstract:
Clamping of a circuit element of a touch screen, such as a gate line of the display system of the touch screen, to a fixed voltage is provided. The circuit element can be clamped during a touch phase and undamped during a display phase of the touch screen. A gate line system of a touch screen can include a first transistor with a source or drain connected to a first gate line, a second transistor with a source or drain connected to a second gate line, and a common conductive pathway connecting gates of the first and second transistors. A synchronization system can switch the first and second transistors to connect the first and second gate lines to a fixed voltage during a touch phase, and can switch the first and second transistors to disconnect the first and second gate lines from the fixed voltage during a display phase.
Abstract:
Reducing or eliminating the effects of noise that can be generated by a power system of a touch screen device, such as a gate line voltage system that applies voltage to gate lines of the touch screen, is provided. In one example, a power supply, such as a charge pump, can be disabled during active touch sensing, such that noise from the charge pump is not generated during touch sensing. In some examples, a voltage regulator can help to maintain the gate voltage level at or above a desired threshold. In some cases, noise entering the touch sensing system can have a lasting effect on noise-sensitive components, even after the noise source is disabled. In these cases, a post-noise stabilizing system can be included to stabilize, reset, etc., noise-sensitive components of the touch sensing system, which can help to reduce or eliminate the lasting effect of noise.
Abstract:
Reducing or eliminating the effects of noise that can be generated by a power system of a touch screen device, such as a gate line voltage system that applies voltage to gate lines of the touch screen, is provided. In one example, a power supply, such as a charge pump, can be disabled during active touch sensing, such that noise from the charge pump is not generated during touch sensing. In some examples, a voltage regulator can help to maintain the gate voltage level at or above a desired threshold. In some cases, noise entering the touch sensing system can have a lasting effect on noise-sensitive components, even after the noise source is disabled. In these cases, a post-noise stabilizing system can be included to stabilize, reset, etc., noise-sensitive components of the touch sensing system, which can help to reduce or eliminate the lasting effect of noise.
Abstract:
Clamping of a circuit element of a touch screen, such as a gate line of the display system of the touch screen, to a fixed voltage is provided. The circuit element can be clamped during a touch phase and undamped during a display phase of the touch screen. A gate line system of a touch screen can include a first transistor with a source or drain connected to a first gate line, a second transistor with a source or drain connected to a second gate line, and a common conductive pathway connecting gates of the first and second transistors. A synchronization system can switch the first and second transistors to connect the first and second gate lines to a fixed voltage during a touch phase, and can switch the first and second transistors to disconnect the first and second gate lines from the fixed voltage during a display phase.