Abstract: We describe a touch sensitive holographic image display device for holographically projecting a touch sensitive image at an acute angle onto a surface on which the device is placed. The device includes holographic image projection optics comprising at least one coherent light source illuminating a spatial light modulator (SLM), output optics to project a hologram onto an acute angle surface, and a remote touch sensing system to remotely detect a touch of a location within or adjacent to the holographically displayed image. A control system is configured to provide data defining an image for display, to receive detected touch data, and to control the device responsive to remote detection of a touch of a the displayed image.

Abstract: A touch sensitive device, the device comprising: a touch sensor light source to project a plane of light above a surface; a camera directed to capture a touch sense image from a region including at least a portion of said plane of light, said touch sense image comprising light scattered from said plane of light by a plurality of said objects simultaneously approaching or touching said surface; a signal processor coupled to said camera, to process a said touch sense image from said camera to identify a lateral location of each of said objects; and an output object position output, to provide output object positions for said plurality of objects; and wherein said signal processor is further configured to: input a succession of said touch sense images; process each said touch sense image to identify a plurality of candidate object touch positions; and filter said candidate object touch positions from said successive touch sense images to link said candidate object touch positions to previously identified output

Abstract: We describe a touch sensitive image display device for projecting a touch sensitive displayed image at an acute angle onto a surface on which the device is placed. The device comprises: light sources to project two-dimensional first and second light distributions in respective first and second planes; and a multi-pixel sensor system to remotely detect touch of an area of said surface within or adjacent to the displayed image by detecting light from the first distribution to provide a detected touch signal. The multi-pixel sensor system also remotely detects presence of an object within the second light distribution to provide a detected presence signal. The device is configured to multiplex projection of the first light and second distributions. A controller has an input to receive the detected touch and detected presence signals and is configured to control the device responsive to these signals.

Abstract: We describe a touch sensitive image display device for projecting a touch sensitive displayed image at an acute angle onto a surface on which the device is placed, the device comprising: a first light source to project a first light distribution; a second light source to project a second light distribution; a touch sensor system to remotely detect touch of an area of said surface within or adjacent to said displayed image by detecting change of said first light distribution, and having an output to provide a detected touch signal; a presence sensor system to remotely detect presence of an object at least partially within said second light distribution by detecting change of said second light distribution, and having an output to provide a detected presence signal; a controller configured to control said device responsive to said detected touch signal and further configured to control said device responsive to said detected presence signal.

Abstract: We describe a touch sensitive holographic image display device for holographically projecting a touch sensitive image at an acute angle onto a surface on which the device is placed. The device includes holographic image projection optics comprising at least one coherent light source illuminating a spatial light modulator (SLM), output optics to project a hologram onto an acute angle surface, and a remote touch sensing system to remotely detect a touch of a location within or adjacent to the holographically displayed image. A control system is configured to provide data defining an image for display, to receive detected touch data, and to control the device responsive to remote detection of a touch of a the displayed image.

Abstract: The invention relates to techniques for sensing of touch events near to a surface using position data from a pair of two-dimensional sensors (a camera and a quadrature detector).

Abstract: We describe a method of determining an aberration correction for a holographic image display system using a spatial light modulator (SLM) to display a hologram. Embodiments of the invention measure the corrections needed for a particular projection system, using the same system SLM as used to generate the images to provide wavefront-sensing holograms. The projector's projection optics are used to provide the wavefront sensor and there is no need for lenslets. Embodiments of the invention use a plurality of successive holograms directing light from differently-located patches on the hologram into the image.

Abstract: We describe a touch sensitive image display device for projecting a touch sensitive displayed image at an acute angle onto a surface on which the device is placed, the device comprising: a first light source to project a first light distribution; a second light source to project a second light distribution; a touch sensor system to remotely detect touch of an area of said surface within or adjacent to said displayed image by detecting change of said first light distribution, and having an output to provide a detected touch signal; a presence sensor system to remotely detect presence of an object at least partially within said second light distribution by detecting change of said second light distribution, and having an output to provide a detected presence signal; a controller configured to control said device responsive to said detected touch signal and further configured to control said device responsive to said detected presence signal.

Abstract: We describe a touch sensitive image display device for projecting a touch sensitive displayed image at an acute angle onto a surface on which the device is placed. The device comprises: light sources to project two-dimensional first and second light distributions in respective first and second planes; and a multi-pixel sensor system to remotely detect touch of an area of said surface within or adjacent to the displayed image by detecting light from the first distribution to provide a detected touch signal. The multi-pixel sensor system also remotely detects presence of an object within the second light distribution to provide a detected presence signal. The device is configured to multiplex projection of the first light and second distributions. A controller has an input to receive the detected touch and detected presence signals and is configured to control the device responsive to these signals.