Abstract: An apparatus for detecting a pointer within a region of interest includes a first reflective element extending along a first side of the region of interest and reflecting light towards the region of interest. A second reflective element extends along a second side of the region of interest and reflects light towards the region of interest. The second side is joined to the first side to define a first corner. A non-reflective region generally in the plane of at least one of the first and second reflective elements is adjacent the first corner. At least one imaging device captures images of the region of interest including reflections from the first and second reflective elements.

Abstract: A touch system includes a touch surface on which an image is, displayed and at least one camera acquiring images of the touch surface. A pointer contact data generator generates pointer position data in response to pointer contact with the touch surface. The pointer position data represents the location of the pointer on the touch surface where pointer contact is made. A processor communicates with the at least one camera and the pointer contact data generator. The processor uses known points in the displayed images to calibrate automatically co-ordinate systems of the touch system, and uses calibrated pointer position data to update image data that is used to present the displayed image on the touch surface. In one embodiment, the touch system includes an active touch sensitive screen that comprises both the touch surface and the pointer contact data generator.

Abstract: A passive touch system includes a passive touch surface and at least two cameras associated with the touch surface. The at least two cameras acquire images of the touch surface from different locations and have overlapping fields of view. A processor receives and processes images acquired by the at least two cameras to detect the existence of a pointer therein and to determine the location of the pointer relative to the touch surface. Actual pointer contact with the touch surface and pointer hover above the touch surface can be determined.

Abstract: An apparatus for detecting a pointer within a region of interest includes at least one pair of imaging devices. The imaging devices have overlapping fields of view encompassing the region of interest. At least one light source provides illumination across the region of interest and is within the field of view of at least one of the imaging device. A filter is associated with the at least one imaging device whose field of view sees the light source. The filter blocks light projected by the light source to inhibit the imaging device from being blinded by the projected light.

Abstract: A camera-based touch system includes at least one pair of cameras having overlapping fields of view and a touch surface encompassed within the overlapping fields of view across which a pointer is moved. The cameras of the at least one pair acquire images at intervals asynchronously. In order to estimate the position of the pointer relative to the touch surface from image data acquired by the at least one pair of cameras, the images are synthetically synchronized. During this process, for each camera in the pair, each acquired image is processed to determine the position of the pointer therein and the position of the pointer is recorded together with a timestamp representing the time elapsed between a reference point common to the cameras and the time the image was acquired.

Abstract: An electronic writeboard for communicating with a computer including applications software and running an active application comprises a touch sensitive panel on which the screen image output of the computer is displayed. The touch sensitive panel is responsive to user contact and generates events. A keyboard window is displayed on the touch sensitive panel and includes a keyboard having a plurality of user selectable keys. A driver receives the events and senses user contact on the touch sensitive panel within the keyboard window and generates messages in response thereto. A controller executing a keyboard application receives the messages. The keyboard application processes the messages to provide data to the active application running on the computer corresponding to keys of the keyboard contacted by the user.

Abstract: A passive touch system includes a touch surface and at least one source of backlight illumination projecting backlighting across the touch surface. At least two image sensors are associated with the touch surface and acquire images of the touch surface from different locations. A digital signal processor is associated with each image sensor. The digital signal processors select pixel subsets of images acquired by the image sensors and process pixel data acquired by the selected pixel subsets to generate pointer characteristic data when a pointer exists in the acquired images. A master digital signal processor in communication with the digital signal processors triangulates the pointer characteristic data to determine the location of the pointer relative to the touch surface.

Abstract: A touch system includes a touch surface and at least two cameras associated with the touch surface. The at least two cameras acquire images of the touch surface from different locations and having overlapping fields of view. A digital signal processor is associated with each camera. The digital signal processors process pixel data acquired by selected pixel subsets of the at least two digital cameras to generate pointer characteristic data when a pointer exists in the acquired images. The pointer characteristic data identifies edges of the pointer. A master digital signal processor triangulates the edge information in the pointer characteristic data to determine a bounding area that represents a pointer perimeter.

Abstract: A system and method for determining pointer contacts on a touch surface includes a touch surface to be contacted by a pointer. At least one imaging device having a field of view looks generally along the touch surface. At least one processor communicates with the at least one imaging device and analyzes images acquired by the at least one imaging device to detect the relative positions of a pointer and a reflection of the pointer therein and thereby determine if a pointer contact with the touch surface has been made.

Abstract: A touch system includes a reference frame, and at least two cameras having fields of view that overlap within the reference frame. The position of an object relative to the reference frame is determined from captured images of the object based on triangulation. The fields of view of the at least two cameras are rotated with respect to the coordinate system of the reference frame to define offset angles.

Abstract: A method of ordering visual objects presented on a display includes comparing visual objects to be placed in an overlapping condition and determining from the comparison the order in which the visual objects are to be placed. The visual objects are re-ordered and placed in the overlapping condition in accordance with the determination. Methods of creating connecting links joining source and destination visual objects as well as overlapping object and object-connecting tools are also provided.

Abstract: A passive touch system includes a passive touch surface and at least two cameras associated with the touch surface. The at least two cameras acquire images of the touch surface from different locations and have overlapping fields of view. A processor receives and processes images acquired by the at least two cameras to detect the existence of a pointer therein and to determine the location of the pointer relative to the touch surface. Actual pointer contact with the touch surface and pointer hover above the touch surface can be determined.

Abstract: An interactive display system comprising a touch sensitive display surface for sensing pressure applied thereto and in response generating control signals indicating locations of the applied pressure, a personal computer for receiving the control signals and in response generating graph images, and an LCD panel in combination with an overhead projector for receiving and projecting the graphic images onto the touch sensitive display surface at the indicated locations. The LCD panel and overhead projector may be provided an an integral unit.

Abstract: An electronic writeboard for communicating with a computer including applications software and running an active application comprises a touch sensitive panel on which the screen image output of the computer is displayed. The touch sensitive panel is responsive to user contact and generates events. A keyboard window is displayed on the touch sensitive panel and includes a keyboard having a plurality of user selectable keys. A driver receives the events and senses user contact on the touch sensitive panel within the keyboard window and generates messages in response thereto. A controller executing a keyboard application receives the messages. The keyboard application processes the messages to provide data to the active application running on the computer corresponding to keys of the keyboard contacted by the user.

Abstract: A touch system includes a touch panel having a touch surface and a projector presenting images onto the touch surface. A computer executing an applications program is coupled to the touch panel and the projector. The computer is responsive to contact output generated by the touch panel in response to proximity of a pointer to the touch surface and updates image data conveyed to the projector so that images presented on the touch surface reflect pointer activity. The computer executes a gesture connector recognition routine. The gesture connector recognition routine performs recognition to convert a freehand connector on the touch surface into a computer-generated connector approximating the freehand connector.

Abstract: An overhead projection system includes an overhead projector support assembly extending outwardly from a generally vertical support surface in a generally horizontal disposition. A display screen having a display surface is mounted on the support surface beneath the projector support assembly. A projector is mounted on the projector support assembly and is aimed to project images onto the display surface of the display screen. Preferably, the projector support assembly includes a governor in the form of a damper and spring arrangement to control downward pivotal movement of the projector support assembly when a load is placed on the projector support assembly and to return the projector support assembly to its generally horizontal disposition when the load is removed.

Abstract: An interactive display system comprising a touch sensitive display surface for sensing pressure applied thereto and in response generating control signals indicating locations of the applied pressure, a personal computer for receiving the control signals and in response generating graph images, and an LCD panel in combination with an overhead projector for receiving and projecting the graphic images onto the touch sensitive display surface at the indicated locations. The LCD panel and overhead projector may be provided an an integral unit.

Abstract: A method for erasing writing on an electronic writeboard includes the steps of describing an eraser as a mask and monitoring movement of the eraser over the electronic writeboard. When the mask overlaps with writing on the electronic writeboard, erasing of the writing within the mask is performed. The shape of the mask is adjusted to compensate for the speed at which the eraser is moved over the electronic writeboard.

Abstract: A method for editing objects representing writing on an electronic writeboard comprises the steps of: creating an object representing writing on the electronic writeboard; determining if the created object overlies an existing object by at least a threshold amount; and merging the created and existing objects to create a new object if the created object overlies the existing object by at least the threshold amount. An editor for editing objects and an interactive display system are also provided.

Abstract: A touch sensitive display panel comprises a noisy display panel having a display screen on which images are displayed. An electronic writeboard is provided on the noisy display panel and overlies the display screen. Images displayed on the display screen are visible through the electronic writeboard. The electronic writeboard detects user input and provides output to alter displayed images. The electronic writeboard includes means to compensate for noise generated by the noisy display panel.