Integrated touch-sensing display apparatus and method of operating the same

A method of operating an integrated touch-sensing display apparatus, which apparatus includes,

• an array of picture elements that defines a display area,
• an array of light-sensing elements integrated to sense light within the display area,
• a light guide located in front of the display area to define a touch surface, the light guide being configured to allow light to propagate inside the light guide by total internal reflection, and
• a light source arrangement, said method comprising:
• controlling said at least one light source arrangement to provide illuminating light inside the light guide, such that an object contacting the touch surface causes frustration of the total internal reflection of the illuminating light and thereby a part of the illuminating light to be scattered towards the display area;
• and
• obtaining image data representing the scattered illuminating light that impinges on the display area based on output signals from the light-sensing elements and independent of signal patterns resulting from ambient light, and determining the location of the object on the touch surface based on the image data;
• wherein
• at least a subset of the light-sensing elements are provided with respective lens devices, each lens device being configured to reduce a field of view of a corresponding light-sensing element,
• each lens device is configured to focus scattered illumination light from a portion of the touch surface onto the corresponding light-sensing element, and
• each lens device is configured such that light scattered by the object contacting the touch surface is projected onto a smaller area than light scattered by an object hovering above the touch surface.

An integrated touch-sensing display apparatus, comprising:

• an array of picture elements that defines a display area;
• an array of light-sensing elements integrated within the display area;
• a light guide located in front of the display area to define a touch surface, the light guide being configured to allow light to propagate inside the light guide by total internal reflection;
• a plurality of lens devices, each of the plurality of lens devices being between the light guide and a corresponding light sensing element, and each of the plurality of lens devices being configured to reduce a field of view of the corresponding light-sensing element;
• a light source arrangement for providing illuminating light inside the light guide, such that an object contacting the touch surface causes frustration of the total internal reflection of the illuminating light and thereby a part of the illuminating light to be scattered towards the display area;
• and
• a processing element configured to obtain, based on output signals from the light-sensing elements, image data that represents the scattered illuminating light that impinges on the display area excluding ambient light, and to determine, based on the image data, the location of the object on the touch surface;
• wherein
• each lens device is configured to focus scattered illumination light from a portion of the touch surface onto the corresponding light-sensing element, and
• each lens device is configured such that light scattered by the object contacting the touch surface is projected onto a smaller area than light scattered by an object hovering above the touch surface.