Abstract: A device obtains a signal representative of objects on a touch surface of a multi-touch sensing apparatus and executes a method for extracting touch data from the signal. The method operates in a sequence of detection frames. Each detection frame comprises the steps of: obtaining (300) the signal; processing (301) the signal for identifying touches; determining (302) a set of identified touches and touch data for the set of identified touches; and outputting (303) the touch data. At least one of the steps of processing (301) and determining (302) includes a prioritization that actively favors certain touches to be identified and included in the set of identified touches, respectively. Temporal prioritization favors a touch that corresponds to a previous touch, which is identified in one or more preceding detection frames. Spatial prioritization favors a touch that is located within at least one predefined subarea on the touch surface.

Abstract: An apparatus is controlled to detect locations of a plurality of objects on a touch surface of a panel. An input scanner arrangement introduces at least three beams of radiation into the panel for propagation by internal reflection, and sweeps the beams inside the panel across a sensing area, preferably in at least two different principal directions. At least one radiation detector is arranged to receive the beams from the input scanner arrangement while they are swept across the sensing area. A data processor is connected to the radiation detector(s) and operated to identify the locations based on an attenuation of the beams caused by the objects touching the touch surface within the sensing area, the attenuation being identifiable from an output signal of the radiation detector(s). Each output signal may be further processed to generate a transmission signal, by dividing the output signal by a background signal which represents the output signal without any object on the touch surface.

Abstract: A touch-sensitive apparatus is configured to define a touch surface on a panel by propagating diverging energy beams across the touch surface inside the panel. Two rows (20A, 20B) of components (2, 3) of a first type that emits energy as a diverging beam and a second type that detects energy are functionally connected to the panel at opposite ends of the touch surface. The rows (20A, 20B) are defined by consecutive component blocks (B) that each contain only components (2, 3) of one type and are defined by type and number of included components. Each row (20A, 20B) is defined to have consecutive component blocks (B) of alternating type. To achieve an improved spatial resolution of the touch-sensitive apparatus for a given number of components, at least one of the rows (20A, 20B) is designed to include at least three different component blocks (B) which differ with respect to at least one of number and type.

Abstract: A device implements a method for estimating the application force of a touching object onto a touch surface in an FTIR-based projection-type touch-sensing apparatus. The apparatus generates projection signals representing radiation that has propagated on a plurality of propagation paths by total internal reflection (TIR) inside a transmissive panel beneath a touch surface of the transmissive panel such that a touching object on the touch surface causes attenuation (frustration) of at least one of the projection signals. The device generates a time series of force values, which represent the application force, based on a time series of magnitude values, which represent a magnitude of a peak in two-dimensional interaction patterns generated by image reconstruction processing of the projection signals, the peak corresponding to the touching object on the touch surface. The force estimation may involve one or more corrections.

Abstract: An interactive display system that may be implemented to provide an electronic whiteboard that enables users to input information to the system by engaging a display with one or more objects. The system may present an image via the display that reflects the inputs received from the user. For example, the display may be dynamically updated to mimic inputs made to a whiteboard by the user via one or more pens and/or an eraser. The interactive display system may implement an underlayer embedded within the display to guide electromagnetic radiation that emanates from an object engaged with the display to one or more detectors by total internal reflection. Due at least in part to the efficiency of the underlayer in guiding the electromagnetic radiation to the detectors, the interactive display system may enhance the speed and/or accuracy of the interpretation of the inputs made by the user.

Abstract: A touch-sensitive apparatus is configured to propagate energy inside a panel (1) so as to define a grid of transmission paths across a touch surface (4) of the panel (1). The apparatus comprises a first subset of components on a first end of the touch surface (4), and a second subset of components on a second end which is opposite to and parallel with the first end. The components include emitters and detectors, each emitter being operable for propagating a diverging energy beam (e.g. radiation) across the touch surface (4) inside the panel (1), and each detector being operable for detecting transmitted energy from at least two emitters. The components in at least one of the first and second subsets are systematically arranged in spatially separate groups along at least one of the first and second ends, so as to achieve a reduced spacing and/or an increased uniformity of the transmission paths along a center line between the first and second ends compared to an equidistant arrangement of all components.

Abstract: An apparatus for determining a location of at least one object on a touch surface, comprising: a light transmissive panel defining the touch surface and including a controllable reflective boundary; an illumination arrangement configured to introduce light into the panel; a control device configured to selectively control the reflective boundary such that the light may pass between a first layer and a second layer via an opening in the reflective boundary; a light detection arrangement configured to measure the light passed via the opening and impinged on the touch surface; and a processor unit configured to determine the location as a function of the measured light passed via the opening and the selective control of the reflective boundary. A method and computer readable medium is also described.

Abstract: A touch-sensing apparatus is based on frustrated total internal reflection (FTIR). The apparatus comprises a panel, in which sheets of light are propagated by internal reflection between a touch surface and an opposite surface. A light sensor arrangement is optically connected to the panel to measure transmitted light energy on detection lines across the touch surface. Each detection line represents a light path across the touch surface from a light source to a light sensor. An object that touches the touch surface will frustrate the propagating light and cause a local attenuation among the detection lines. A data processor is connected to the light sensor arrangement and configured to execute a process for extracting touch-related data.

Abstract: A touch-sensitive apparatus is configured to define a touch surface on a panel by propagating diverging energy beams (e.g. of radiation) across the touch surface inside the panel. Two rows (20A, 20B) of components (2, 3) of a first type that emits energy as a diverging beam and a second type that detects energy are functionally connected to the panel at opposite ends of the touch surface. The rows (20A, 20B) are defined by consecutive component blocks (B) that each contain only components (2, 3) of one type and are defined by type and number of included components. Each row (20A, 20B) comprises a respective sequence (S) of two component blocks (B) of different types and is defined by systematically repeating the sequence (S) along the respective opposite end.

Abstract: A device implements a method of tracking objects on a touch surface of an FTIR based touch-sensitive apparatus. The method repeatedly operates to generate an interaction pattern that indicates local changes in interaction on the touch surface, identify apparent peaks in the interaction pattern, and update existing movement trajectories based on the apparent peaks. An error suppression process is executed at least intermittently in the method to process the apparent peaks and/or the existing movement trajectories to identify implicated trajectories with a potential tracking problem, define two or more movement propositions for each implicated trajectory, and cause an evaluation of the movement propositions in one or more subsequent repetitions of the method. The error suppression process improves tracking by postponing the final decision on how to track the object of the implicated trajectory until more information is available.

Abstract: Touch sensitivity is enabled using a touch system that comprises a panel configured to conduct signals, e.g. by TIR, along detection lines across a rectangular touch surface with first and second spatial dimensions. A signal processor operates to transform energy values for the detection lines into Fourier coefficients arranged as data points on a regular grid defined by first and second frequency dimensions. To generate an interaction pattern for the touch surface, the signal processor operates a first 1D inverse FFT on the data points with respect to the second frequency dimension, so as to generate first values transformed into the second spatial dimension, and operates a second 1D inverse FFT on a selected subset of the first values with respect to the first frequency dimension to generate second values that represent the interaction pattern.

Abstract: A touch-sensing display panel, comprising a plurality of image-forming pixel elements; a planar light guide with a first refractive index, having a front surface forming a touch-sensing region and an opposite rear surface facing the pixel elements; a plurality of light emitters arranged at a peripheral region of the panel to emit light into the light guide for propagation therein through total internal reflection; a plurality of light detectors disposed at the peripheral region for receiving light from the light guide; and an optical layer disposed at the rear surface of the light guide to cover a plurality of the image-forming pixel elements in at least a central region of the panel, wherein said optical layer is configured to reflect at least a part of the light from the emitters impinging thereon from within the light guide.

Abstract: A device implements a method of tracking objects on a touch surface of an FTIR based touch-sensitive apparatus.

Abstract: An apparatus is operated to determine the location of at least one object on a touch surface of a light transmissive panel. In the apparatus, an illumination arrangement introduces radiation into the panel for propagation by internal reflection between the touch surface and the opposite surface, so as to generate a grid of intersecting radiation paths in a sensing area, and a detection arrangement measures the transmitted energy in the radiation paths. A data processor then determines, based on the transmitted energy, the location based on an attenuation of two or more radiation paths caused by the object touching the touch surface within the sensing area. In the apparatus, the illumination arrangement generates at least a subset of the radiation paths by sweeping at least one beam of radiation along the touch surface.

Abstract: Touch sensitivity is enabled using a touch system that comprises a panel configured to conduct signals, e.g. by TIR, from a plurality of incoupling points to a plurality of outcoupling points, thereby defining detection lines across a touch surface between pairs of incoupling and outcoupling points. A signal processor operates in a repeating sequence of iterations to: calculate change values for the detection lines representative of signal changes between the current and a previous iteration, and operate a reconstruction algorithm on the change values to determine a differential interaction pattern across the touch surface. The signal processor also operates to update a tracking pattern as a function of the differential interaction pattern, and generate a current offset pattern based on the tracking pattern. The offset pattern is generated to represent current touch interaction on the touch surface and is supplied for identification of touches on the surface portion.

Abstract: A touch-sensing display apparatus comprises a display unit with integrated elements, and a planar light guide located in front of the display unit so as to define a touch surface. At least one light emitter is arranged to emit light into the light guide for propagation by total internal reflection inside the light guide, and at least one light detector is arranged to receive at least part of the light propagating inside the light guide. The integrated elements are designed as image-forming elements and touch-sensor elements, wherein the touch-sensor elements comprise the emitter(s) and/or the detector(s) and are arranged along a periphery region of the display unit. The image-forming elements and the touch-sensor elements may be integrated in one and the same composite substrate within the display unit.

Abstract: A touch-sensitive apparatus for determining a location of at least one object on a touch surface. The touch-sensitive apparatus extends in a direction of depth and comprises a light transmissive panel, a display arranged behind the light transmissive panel, and a first compartment and second compartment arranged behind the display. Light from a light emitter arrangement in the first compartment is introduced into the light transmissive panel for propagation by internal reflection. The light is thereafter coupled out to be received by a light detection arrangement in the second compartment. The first and second compartments are separated, such that light from the light emitter arrangement is prevented from reaching the light detection arrangement without first having propagated in the light transmissive panel.

Abstract: A touch-sensitive apparatus operates by FTIR (Frustrated Total Internal Reflection) to detect touches on a surface of a light transmissive panel. An illumination arrangement is controlled to propagate light by internal reflection from an elongated incoupling site on the panel to an elongated outcoupling site on the panel, and a detection arrangement is controlled to detect light reaching the outcoupling site. The illumination arrangement is controlled to sweep a first set of individual beams of light along different subsets of the incoupling site to generate a full beam sweep along the incoupling site. Thereby, the individual beams are be controlled to generate a “sub-sweep” of the incoupling site, which enables a compact design of the illumination arrangement and/or use of comparatively simple sweep generating devices and/or identical re-direction components in the illumination arrangement.

Abstract: An integrated touch-sensing display is operated to detect the location of one or more objects on a touch surface. The integrated touch-sensing display defines a display area. A light guide (14) is arranged over the display area to define the touch surface (16). The light guide (14) is illuminated internally such that an object (20) contacting the touch surface (16) causes part of the illuminating light to be scattered towards the display area. An array of light sensors (6) is integrated within the display area to detect the scattered light. Based on output signals from the light sensors (6), a processing element obtains image data that represents the light that impinges on the display area excluding ambient light, and determines the location of the object (20) on the touch surface (16). Ambient light may be suppressed by a spectral passband filter in front of each light sensor (6), and/or by electronic filtering of the output signals from the sensors (6).

Abstract: Objects touching a surface portion attenuate transmitted signals. A data processor processes an output signal from a detector coupled to the outcoupling points, to generate a set of data samples indicative of detected energy for the actual detection lines. The set of data samples is further processed to generate a set of matched samples indicative of estimated detected energy for fictitious detection lines that extend across the surface portion in parallel groups at a plurality of different angles. The individual spacing between the fictitious detection lines in each group and the individual difference in angle between said groups are selected such that the set of matched samples transforms to Fourier coefficients arranged as data points on a pseudo-polar grid in a Fourier domain. The set of matched samples is processed by tomographic reconstruction to generate a two-dimensional distribution of an interaction parameter within the surface portion.