Abstract: Dynamic registration of event handlers in a computer application or operating system recognizes multiple synchronous input streams by identifying each new stroke in a frame representing a single moment in time and mapping in a registration process each identified new stroke to a listening process that is associated with the user interface element to which the new input stream is to he applied. In the same frame, released strokes are unmapped and then each active listening process is called to carry out a respective control operation. When called, the strokes have the correct data for the given frame. The process is repeated for subsequent frames. By carrying out various processes in a sequence of frames, the concept of concurrency is preserved, which is particularly beneficial to multi-touch and multi-user systems.

Abstract: A process for enabling objects displayed on a multi-input display device to be grouped together is disclosed that includes defining a target element that enables objects displayed on a multi-input display device to be grouped together through interaction with the target element. Operations are invoked that establish a relationship between a particular displayed object and a position on the target element and that causes transformations applied to the target element also to be applied to the particular displayed object while maintaining the relationship between the particular displayed object and the position on the target element.

Abstract: Dynamic registration of event handlers in a computer application or operating system recognizes multiple synchronous input streams by identifying each new stroke in a frame representing a single moment in time and mapping in a registration process each identified new stroke to a listening process that is associated with the user interface element to which the new input stream is to be applied. In the same frame, released strokes are unmapped and then each active listening process is called to carry out a respective control operation. When called, the strokes have the correct data for the given frame. The process is repeated for subsequent frames. By carrying out various processes in a sequence of frames, the concept of concurrency is preserved, which is particularly beneficial to multi-touch and multi-user systems.

Abstract: Methods, systems, and apparatus, including computer programs encoded on a computer storage medium, for input classification for multi-touch systems. In one aspect, a method includes maintaining a history of prior state information related to a touch sensitive display. The method further includes detecting that a previous contact with the touch sensitive display was incorrectly classified. The method further includes updating a classification of the previous contact based on the detection that the previous contact was incorrectly classified. The method further includes rewinding a state of the touch sensitive display to reflect a state that would have resulted had the previous contact been correctly classified based on the history of prior state information and the updated classification of the previous contact.

Abstract: A process for enabling objects displayed on a multi-input display device to be grouped together is disclosed that includes defining a target element that enables objects displayed on a multi-input display device to be grouped together through interaction with the target element. Operations are invoked that establish a relationship between a particular displayed object and a position on the target element and that causes transformations applied to the target element also to be applied to the particular displayed object while maintaining the relationship between the particular displayed object and the position on the target element.

Abstract: Methods, systems, and apparatus, including computer programs encoded on a computer storage medium, for digital signal processing (DSP) techniques for generally improving a signal-to-noise ratio (SNR) of capacitive touch sensors.

Abstract: Controlling virtual objects displayed on a display device includes controlling display, on a display device, of multiple virtual objects, each of the multiple virtual objects being capable of movement based on a first type of input and being capable of alteration based on a second type of input that is different than the first type of input, the alteration being different from movement. A subset of the multiple virtual objects as candidates for restriction is identified, and based on identifying the subset of virtual objects as candidates for restriction, a responsiveness to the first type of input for the subset of virtual objects is restricted. The first type of input applied to a first virtual object included in the subset of virtual objects and a second virtual object included in the multiple virtual objects is detected, with the second virtual object being excluded from the subset of virtual objects.

Abstract: Methods, systems, and apparatus, including computer programs encoded on a computer storage medium, for digital signal processing (DSP) techniques for generally improving a signal-to-noise ratio (SNR) of capacitive touch sensors.

Abstract: Methods, systems, and apparatus, including computer programs encoded on a computer storage medium, for input classification for multi-touch systems. In one aspect, a method includes receiving data describing a first region of contact with a touch sensitive display and a second region of contact with the touch sensitive display. The method includes determining at least one characteristic of the first region of contact. The method includes based on the at least one characteristic of the first region of contact, determining that the first region of contact corresponds to intended touch input provided by a user's body part or stylus. The method includes determining at least one characteristic of the second region of contact. The method includes based on the at least one characteristic of the second region of contact, determining that the second region of contact corresponds to incidental touch input provided by a user's resting body part.

Abstract: Objects displayed on a display component of a multi-touch display device may be assigned to and displayed at various visual layers, with each visual layer corresponding to a different depth relative to a foreground (or background) of the display component of the multi-touch display device. One or more annotations may be generated in response to user interaction with the multi-touch display device, with each annotation being assigned to an appropriate visual layer.

Abstract: Methods, systems, and apparatus, including computer programs encoded on a computer storage medium, for input classification for multi-touch systems. In one aspect, a method includes receiving data describing a first region of contact with a touch sensitive display, a second region of contact with the touch sensitive display, and a third region of contact with the touch sensitive display, the second region of contact being separate from the first region of contact and the third region of contact being separate from the first region of contact and the second region of contact. The method includes classifying the first region of contact as a touch point provided by a user's body part. The method includes classifying the second region of contact as incidental touch input provided by a user's resting body part. The method includes classifying the third region of contact as a stylus input.

Abstract: One embodiment provides a system for processing gesture inputs on a touch screen display. The system receives a gesture input on the touch screen display. When the gesture is recognized as invoking an annotation canvas, the system determines the height, width and location of an annotation canvas, and displays the annotation canvas on the touch screen display. Then, in response to an input gesture within the annotation canvas, the system recognizes the gesture as an annotation gesture, and executes the annotation gesture. In response to receiving an input gesture outside of the annotation canvas, the gesture is interpreted by the system as a navigation input.

Abstract: Methods and systems for interfacing with multi-input devices employ various techniques for controlling the window framing of images. Such techniques provide control, including moving, sizing, and orientating, of one or more displayed window frames in which one or more images are displayed.

Abstract: Systems are described for transmitting and receiving signals in an active stylus for a capacitive touch sensor, for which the systems have at least one circuit for receiving a current from an electrode and for transmitting a voltage onto the electrode. The systems include components for receiving the current in a receiving mode, a switch, and a switchmode power supply circuit having at least a transformer and a diode, for which the diode is coupled to the transformer. In a transmission mode, there is means for electrically isolating at least some of the components configured for receiving the current in the receiving mode from the voltage formed across the stray capacitance. In the receiving mode, there is a means for electrically isolating at least some of the components configured for receiving the current in the receiving mode from an inductance of the transformer in the switchmode power supply circuit.

Abstract: A touch-screen device includes an imaging waveguide, in which the imaging waveguide has a radiation receiving surface and an imaging surface different than the radiation receiving surface. The imaging waveguide is configured to receive, at the radiation receiving surface, radiation emitted by a contact receiving structure, and transmit the received radiation from a position on the radiation receiving surface to a position and/or angle of incidence on the imaging surface as a function of the position on the radiation receiving surface at which the transmitted radiation was received. An imaging sensor coupled to the imaging surface of the imaging optical waveguide is configured to detect radiation incident upon the imaging surface of the imaging optical waveguide. A processing device coupled to the imaging sensor is configured to determine contact points on the exposed contact surface of a contact receiving structure based on radiation detected by the imaging sensor.

Abstract: Methods, systems, and apparatus relate to touch sensors that are configured to measure input applied to the sensor from a user. Some implementations involve the measurement of changes in capacitance between pairs of adjacent patterned electrodes to detect input at a touch sensor.

Abstract: Methods and systems for interfacing with multi-input devices employ various techniques for controlling the window framing of images. Such techniques provide control, including moving, sizing, and orientating, of one or more displayed window frames in which one or more images are displayed.

Abstract: A tensioning system includes a layer of a device and a flexible overlay film that is configured to cover the layer of the device. A tensioning mechanism is configured to tension the flexible overlay film against the layer of the device throughout a periphery. The tensioning mechanism also is configured to allow movement of the flexible overlay film in two dimensions.

Abstract: Systems are described for transmitting and receiving signals in an active stylus for a capacitive touch sensor, for which the systems have at least one circuit for receiving a current from an electrode and for transmitting a voltage onto the electrode. The systems include components for receiving the current in a receiving mode, a switch, and a switchmode power supply circuit having at least a transformer and a diode, for which the diode is coupled to the transformer. In a transmission mode, there is means for electrically isolating at least some of the components configured for receiving the current in the receiving mode from the voltage formed across the stray capacitance. In the receiving mode, there is a means for electrically isolating at least some of the components configured for receiving the current in the receiving mode from an inductance of the transformer in the switchmode power supply circuit.

Abstract: A matrix of light emitting diodes is positioned behind a liquid crystal layer of a display device. The light emitting diodes operate in both light emitting and light detecting modes. Consequently, the display device is able to sense objects or fingers approaching or in contact with a front display surface of the display device based on changes in incident light on the matrix that are observed by one or more of the light emitting diodes operating in the light detecting mode.