Abstract:
Differential driving and/or sensing can reduce noise in a touch screen. In some examples, the touch screen can include column and row electrodes routed vertically in the active area. In some examples, the touch electrodes and/or routing traces can be implemented using metal mesh in first and second metal layers. To improve optical performance, overlapping portions of metal mesh can be designed to provide an appearance of uniform width/area. In some examples, a dielectric layer can have an increased thickness and/or a reduced dielectric constant, and/or metal mesh in the first metal layer can be flooded with a transparent conductive material. In some examples, routing traces can be disposed beneath touch electrodes and/or metal mesh for touch electrodes can be flooded with a transparent conductive material without flooding metal mesh for routing traces. In some examples, touch electrodes can be interleaved within a touch node to improve differential cancelation.
Abstract:
A touch panel electrode structure for user grounding correction in a touch panel is disclosed. The electrode structure can include an array of electrodes for sensing a touch at the panel, and multiple jumpers for selectively coupling groups of the electrodes together to form electrode rows and columns that cross each other. In some examples, the array can have a linear configuration and can form the rows and columns by coupling diagonally adjacent electrodes using the jumpers in a zigzag pattern, or the array can have a diamond configuration and can form the rows and columns by coupling linearly adjacent electrodes using the jumpers in a linear pattern. In various examples, each electrode can have a solid structure with a square shape, a reduced area with an outer electrode and a physically separate center electrode, a hollow center, or a solid structure with a hexagonal shape.
Abstract:
Acoustic touch detection (touch sensing) system architectures and methods can be used to detect an object touching a surface. Position of an object touching a surface can be determined using time-of-flight (TOF) bounding box techniques, or acoustic image reconstruction techniques, for example. Acoustic touch sensing can utilize transducers, such as piezoelectric transducers, to transmit ultrasonic waves along a surface and/or through the thickness of an electronic device. Location of the object can be determined, for example, based on the amount of time elapsing between the transmission of the wave and the detection of the reflected wave. An object in contact with the surface can interact with the transmitted wave causing attenuation, redirection and/or reflection of at least a portion of the transmitted wave. Portions of the transmitted wave energy after interaction with the object can be measured to determine the touch location of the object on the surface of the device.
Abstract:
A self-capacitive touch sensor panel configured to have a portion of both the touch and display functionality integrated into a common layer is provided. The touch sensor panel includes a layer with circuit elements that can switchably operate as both touch circuitry and display circuitry such that during a touch mode of the device the circuit elements operate as touch circuitry and during a display mode of the device the circuit elements operate as display circuitry. The touch mode and display mode can be time multiplexed. By integrating the touch hardware and display hardware into common layers, savings in power, weight and thickness of the device can be realized.
Abstract:
Capacitive touch panels may include a plurality of positive voltage lines that are driven at a first phase. These positive voltage lines may be used to provide the drive capacitance signal sensed by one or more sense regions. The touch panels may also include a plurality of negative phase voltage lines that are driven at a phase that is different than the first phase. Both the positive and negative voltage lines may cross-under one or more sense regions. The negative phase voltage lines are able to counter act and reduce the static capacitance in the sense regions.
Abstract:
A touch panel electrode structure for user grounding correction in a touch panel is discloses. The electrode structure can include an array of electrodes for sensing a touch at the panel, and multiple jumpers for selectively coupling groups of the electrodes together to form electrode rows and columns that cross each other. In some examples, the array can have a linear configuration and can form the rows and columns by coupling diagonally adjacent electrodes using the jumpers in a zigzag pattern, or the array can have a diamond configuration and can form the rows and columns by coupling linearly adjacent electrodes using the jumpers in a linear pattern. In various examples, each electrode can have a solid structure with a square shape, a reduced area with an outer electrode and a physically separate center electrode, a hollow center, or a solid structure with a hexagonal shape.
Abstract:
A touch panel capable of measuring both mutual and self capacitance is disclosed. The touch panel can measure self capacitance and mutual capacitance at various electrode patterns and, based on the self capacitance measurements, the mutual capacitance measurements, or both, calculate a touch signal indicative of an object touching or hovering over the touch panel. In some examples, the measurements can also be used to determine a correction factor, indicative of an adverse condition at the touch panel, and the correction factor used to correct the touch signal for the adverse condition. The touch panel can have a row-column electrode pattern or a pixelated electrode pattern.
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:
Operating touch screens by applying more than one voltage modes, including a first voltage mode corresponding to a display phase and a second voltage mode corresponding to a touch sensing phase, is provided. An integrated touch screen device can include a multi-mode power system that can select a first voltage mode corresponding a display phase and a second voltage mode corresponding to a touch sensing phase. Each of one or more voltages can be applied to the touch screen at the corresponding first voltage level during the updating of the image. A touch sensing system can sense touch during a touch sensing phase. Each of one or more voltages can be applied to the touch screen at the corresponding second voltage level during the sensing of touch.
Abstract:
Power consumption of touch sensing operations for touch sensitive devices can be reduced by implementing a coarse scan (e.g., banked common mode scan) to coarsely detect the presence or absence of an object touching or proximate to a touch sensor panel and the results of the coarse scan can be used to dynamically adjust the operation of the touch sensitive device to perform or not perform a fine scan (e.g., targeted active mode scan). In some examples, the results of the coarse scan can be used to program a touch controller for the next touch sensing frame to idle when no touch event is detected or to perform a fine scan when one or more touch events are detected. In some examples, the results of the coarse scan can be used to abort a scheduled fine scan during the current touch sensing frame when no touch event is detected.