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: Placement by one or more input mechanisms of a touch point on a multi-touch display device that is displaying a three-dimensional object is detected. A two-dimensional location of the touch point on the multi-touch display device is determined, and the touch point is matched with a three-dimensional contact point on a surface of the three-dimensional object that is projected for display onto the image plane of the camera at the two-dimensional location of the touch point. A change in applied pressure at the touch point is detected, and a target depth value for the contact point is determined based on the change in applied pressure. A solver is used to calculate a three-dimensional transformation of the three-dimensional object using an algorithm that reduces a difference between a depth value of the contact point after object transformation and the target depth value.

Abstract: A three-dimensional object is initially transformed using an initial three-dimensional transformation in response to the detected movement of at least one touch point of a set of touch points placed on a multi-touch display device, each touch point in the set being matched with a contact point on the surface of the object. If the initially transformed object does not correspond to a rotational exhaustion situation, displaying the initially transformed object on the multi-touch display device. If the initially transformed object corresponds to a rotational exhaustion situation, calculating a corrected three-dimensional transformation of the object by using an algorithm that fixes at least one degree of freedom of object orientation to a value corresponding to an orientation of the object prior to the detected movement of the at least one touch point. Transforming the object using the corrected three-dimensional transformation and displaying the transformed object.

Abstract: A three-dimensional transformation of a three-dimensional object is calculated by a solver using an algorithm that reduces deviation between projected two-dimensional locations of three-dimensional contact points on a surface of the object after object transformation and two dimensional locations of touch points placed on a multi-touch display device. The algorithm is biased to generate a three-dimensional transformation that preferentially rotates the object in one direction over an opposite direction when all three-dimensional contact points are located at substantially the same depth along a Z-axis away from an image plane of the multi-touch display device and when transformation is then triggered by touch points moving such that a Euclidean distance between at least two of the touch points decreases.

Abstract: Manipulating a three-dimensional object displayed in a multi-touch display device includes displaying a three-dimensional object in two dimensions on the multi-touch display device. Placement of one or more touch points on the multi-touch display device is detected. For each detected touch point, a location of the touch point on the multi-touch display device is determined and a matching contact point on a surface of the three-dimensional object that is displayed by the multi-touch display device at the location of the touch point is also determined. Movement of at least one of the touch points is detected. Subsequent to the detected movement of the one or more touch points, a three-dimensional transformation of the three-dimensional object is determined that results in a display in which the contact points on the surface of the three-dimensional object remain displayed substantially at the locations of their matching touch points.

Abstract: High-resolution, scalable multi-touch sensing display systems and processes based on frustrated total internal reflection employ an optical waveguide that receives light, such as infrared light, that undergoes total internal reflection and an imaging sensor that detects light that escapes the optical waveguide caused by frustration of the total internal reflection due to contact by a user. The optical waveguide may be fitted with a compliant surface overlay to greatly improve sensing performance, minimize the affect of contaminants on and damage to the contact surface, to generally extend system life and to provide other benefits. The systems and processes provide true multi-touch (multi-input) and high-spatial and temporal resolution capability due to the continuous imaging of the frustrated total internal reflection that escapes the entire optical waveguide.

Abstract: A multi-touch display device is configured to enable control of a displayed object by less than all of the input mechanisms determined to be engaging the displayed object at the same time.

Abstract: Methods and systems for interfacing with multi-point input devices employ various techniques for controlling displayed images, including 2D and 3D image translation, scale/zoom, rotation control and globe axis tilt control. Various techniques employ three or more simultaneous inputs, changes in characteristics of those inputs, and pressure sensing, among other things.

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: Techniques for constraining motion of 3D objects displayed on a 2D display interface are described. Touch points are placed by a user on the 2D display interface to manipulate a displayed object. Each touch point is matched with a contact point on the surface of the object. The motion of the object is restricted by adding penalty terms to an energy equation that includes terms that measure deviation between the screen-space location of the touch points and that of their matching contact points. The penalty terms measure deviation from an ideal value. In response to movement of at least one touch point to a new screen-space location, a transformation of the object is determined by applying an algorithm that operates on the energy equation to reduce deviations between the screen-space location of the touch points and that of their matching contact points while also reducing deviation from the ideal value or values set by the penalty term or terms.

Abstract: Each touch point placed on a multi-touch display device is matched with a contact point on a surface of a three-dimensional object displayed on the multi-touch display device. A three-dimensional transformation of the object is calculated by a solver using an algorithm that reduces deviation between projected two-dimensional locations of the three-dimensional contact points after object transformation and two dimensional locations of their matching touch points. The solver, in calculating the three-dimensional transformation, assigns a weighting value to each touch point to distribute an aggregate amount of deviation calculated by the solver among the touch points such that a magnitude of the deviation between the projected two-dimensional location of one of the contact points and that of its matching touch point is different from a magnitude of the deviation between the projected two dimensional location of another contact point and that of its matching touch point.

Abstract: Methods and systems for interfacing with multi-point input devices employ various techniques for controlling displayed images, including 2D and 3D image translation, scale/zoom, rotation control and globe axis tilt control. Various techniques employ three or more simultaneous inputs, changes in characteristics of those inputs, and pressure sensing, among other things.

Abstract: High-resolution, scalable multi-touch sensing display systems and processes based on frustrated total internal reflection employ an optical waveguide that receives light, such as infrared light, that undergoes total internal reflection and an imaging sensor that detects light that escapes the optical waveguide caused by frustration of the total internal reflection due to contact by a user. The optical waveguide when fitted with a compliant surface overlay provides superior sensing performance, as well as other benefits and features. The systems and processes described provide true multi-touch (multi-input) and high-spatial and temporal resolution capability due to the continuous imaging of the frustrated total internal reflection that escapes the entire optical waveguide. Among other features and benefits, the systems and processes are scalable to large installations.

Abstract: High-resolution, scalable multi-touch sensing display systems and processes based on frustrated total internal reflection employ an optical waveguide that receives light, such as infrared light, that undergoes total internal reflection and an imaging sensor that detects light that escapes the optical waveguide caused by frustration of the total internal reflection due to contact by a user. The optical waveguide when fitted with a compliant surface overlay provides superior sensing performance, as well as other benefits and features. The systems and processes described provide true multi-touch (multi-input) and high-spatial and temporal resolution capability due to the continuous imaging of the frustrated total internal reflection that escapes the entire optical waveguide. Among other features and benefits, the systems and processes are scalable to large installations.

Abstract: High-resolution, scalable multi-touch sensing display systems and processes based on frustrated total internal reflection employ an optical waveguide that receives light, such as infrared light, that undergoes total internal reflection and an imaging sensor that detects light that escapes the optical waveguide caused by frustration of the total internal reflection due to contact by a user. The optical waveguide when fitted with a compliant surface overlay provides superior sensing performance, as well as other benefits and features. The systems and processes described provide true multi-touch (multi-input) and high-spatial and temporal resolution capability due to the continuous imaging of the frustrated total internal reflection that escapes the entire optical waveguide. Among other features and benefits, the systems and processes are scalable to large installations.

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: Methods, systems, and apparatus relate to capacitive touch sensors with a fine-pointed, active stylus. The active stylus is configured to receive a signal from the capacitive touch sensor for synchronizing a time base of the stylus with the capacitive touch sensor. The active stylus is configured to receive a signal from a matrix of the capacitive touch sensor to measure a first position along one axis, and transmit a signal from the single electrode of the stylus to the matrix to indicate a second position of the stylus along another axis of the matrix. The stylus can transmit the received signal to report the first position of the stylus.

Abstract: High-resolution multi-touch sensor and display device where the interaction medium is liquid, enabling more realistic tactile experience for simulations of synthetic wet environments. Based on frustrated total internal reflection, the device employs liquid within a tank as the optical waveguide that receives light, such as infrared light, that undergoes total internal reflection and an imaging camera that detects light that escapes from the tank caused by frustration of the total internal reflection due to contact of the water by a user.

Abstract: Methods, systems, and apparatus relate to touch sensors that are configured to measure a true capacitive touch and a force applied to the sensor from a user. Some implementations involve the measurement of force and true capacitive touch simultaneously in a touch capacitive sensor.

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.