Flatfrog Laboratories Ab

Henrik Wall

Tomas Christiansson

Ola Wassvik

Nicklas Ohlsson

Christer Fåhraeus

Mats Petter Wallander

Christer Fahraeus

Mattias Krus

Peter Juhlin

Tomas Svensson

Andreas Johansson

Christer Føhraeus

A method of operating an optical touch apparatus is described wherein, the optical touch apparatus comprising a panel, a plurality of emitters and a plurality of detectors arranged with respect to the panel, the plurality of detectors configured to receive light from the plurality of emitters thereby defining detection samples of light transmitted between pairs of emitters and detectors. The optical touch apparatus being further configured to operate in an ambient light evaluation mode comprising the steps of: generating a first set of samples over a first integration time and a second set of samples over a second integration time using at least one detector, and applying a filter to at least the first and second set of samples to generate a residual ambient light value indicative of ambient light noise, wherein the touch apparatus is configured to perform the following steps: operating according to the ambient light evaluation mode for a plurality of repetitions.

Automatic optimisation of touch signal

A touch sensing apparatus includes a group of emitters arranged to emit light to illuminate at least part of the touch surface, a light detector arranged to receive light from the group of emitters, and a processing element. Each emitter is controlled to transmit a code by way of the emitted light such that the code identifies the respective emitter. The codes may at least partly be transmitted concurrently. The codes may be selected such that a value of an autocorrelation of each code is significantly higher than a value of a cross-correlation between any two codes of different emitters. The processing element processes an output signal from the light detector to separate the light received from the individual emitters based on the transmitted codes, and to determine the position of the object/objects based on the light received from the individual emitters.

Touch sensing apparatus and method of operating the same

The disclosure relates to a touch sensitive system comprising a touch sensitive panel defining a touch surface, a plurality of emitters configured to emit light into the panel for propagation in the panel, a plurality of detectors configured to detect the light propagating in the panel, a plurality of distributed control devices each configured to control operation of a segment of emitters and detectors, a main control unit configured to control the distributed control devices. The touch sensitive system is configured to be set in a partial detect mode in which mode a first of the distributed control devices is configured to be active and to control a first emitter to emit light in a partial region of the panel coincident with a partial area of the touch surface. The touch sensitive system is further configured to detect a predetermined gesture on the partial area of the touch surface, generate a gesture signal indicating the predetermined gesture, and activate a feature of the touch sensitive system in accordance with the predetermined gesture. The disclosure also relates to a method in connection with the touch sensitive system.

Partial detect mode

A multi-touch system includes a panel for conducting signals, e.g. by FTIR, from incoupling points to outcoupling points, to define detection lines across the panel. A signal processor operates in a repeating sequence of iterations to obtain an output signal from a detector coupled to the outcoupling points and generate a formatted signal value for each detection line, and operate a reconstruction algorithm on the formatted signal values to determine an interaction pattern on the panel. The signal processor also, at least intermittently in the sequence of iterations, operates compensation data on the formatted signal values to compensate for contaminations on the panel, and calculates updated compensation data based on an interference pattern determined as a function of the interaction pattern, the interference pattern being a 2D representation of contamination-induced signal interferences. The influence of contaminations in the interaction pattern is thereby suppressed.

Touch determination with signal compensation

Multi-touch sensitivity is enabled using a touch system that comprises a panel configured to conduct signals, e.g. by FTIR, from a plurality of incoupling points to a plurality of outcoupling points, thereby defining detection lines across the panel between pairs of incoupling and outcoupling points. A signal processor operates in a repeating sequence of iterations to obtain () a current signal value for each detection line, and generate (') a first interaction pattern and a second interaction pattern as a function of the current signal values, such that the first and second interaction patterns are reconstructed two-dimensional distributions of local interaction with the conducted signals across the surface portion, and represent changes in interaction on different time scales. Thereby, the movement of an object will affect how it is represented in each of the first and second interaction patterns.

Multi-touch detection in a touch system

An apparatus, method and computer-readable medium for determining a location of at least one object on a touch surface of a light transmissive panel. The method comprises the steps of: introducing light into the panel for propagation by internal reflection between the touch surface and an opposite surface; receiving the light propagating in the panel; and iteratively i) determining a current signal profile of light received by the light detection arrangement, ii) updating, when a condition is met, a background signal profile of light received by the light detection arrangement, iii) calculating a current compensated signal profile as a function of the background signal profile and the current signal profile and iv) determining, when the object touches the touch surface and thereby attenuates the light propagating in the panel, the location as a function of the compensated signal profile.

Touch surface with a compensated signal profile

A touch sensing apparatus is controlled to determine the position of one or more objects () that interact with a touch surface (). The apparatus includes a group of emitters () arranged to emit light to illuminate at least part of the touch surface (), a light detector () arranged to receive light from the group of emitters (), and a processing element (). Each emitter () is controlled to transmit a code by way of the emitted light such that the code identifies the respective emitter (). The codes may at least partly be transmitted concurrently. The codes may be selected such that a value of an autocorrelation of each code is significantly higher than a value of a cross-correlation between any two codes of different emitters (). The processing element processes an output signal from the light detector () to separate the light received from the individual emitters () based on the transmitted codes, and to determine the position of the object/objects () based on the light received from the individual emitters (), e.g. using triangulation or image reconstruction such as an algorithm for transmission tomography.

Growing community of inventors

Dalby, Sweden

Henrik Wall