Device for detecting the presence of a tangible document in an image acquisition apparatus

In an image acquisition apparatus, including a housing having an internal space and a substantially transparent surface for supporting a tangible document during an image acquisition operation, a document sensing device for detecting if at least a portion of said transparent surface is covered by said tangible document, said document sensing device comprising:

• (a) a transparent support structure for supporting at least one edge of said tangible document comprising:
• i. a first supporting element having a first supporting surface for supporting a first edge of said tangible document, wherein said supporting surface is disposed in alignment with a first edge of said transparent surface;
• and
• ii. a first transparent attachment structure for firmly attaching said support structure to said housing;
• (b) a layer of coating configured to reflect light, wherein said layer of coating covering at least a portion of the external surfaces of said transparent support structure;
• (c) a first light source;
• and
• (d) a light intensity sensor disposed inside said internal space,
• wherein said first light source is disposed inside said image acquisition apparatus, directionally illuminating said first attachment structure towards said first supporting element;
• wherein said layer of coating reflects a substantial portion of the light transmitted by said first light source, towards said transparent surface and said internal space;
• wherein a substantial portion of said light is sensed by said light intensity sensor, said transparent surface being exposed, whereby said light intensity sensor detected a high intensity level, and wherein when said tangible document blocks a substantial portion of said light from reaching said transparent surface, said light intensity sensor detected a low intensity level;
• and
• wherein the difference between said high intensity level and said low intensity level is associated with the presence of said tangible document on said transparent surface.