Handheld display device for associating multimedia objects with printed substrates

A handheld display device for overlaying a printed substrate and for associating a multimedia object with a zone of said printed substrate, said device comprising:

• a memory storing one or more multimedia objects;
• an optical sensor for imaging an area of the printed substrate and for generating image data;
• a processor for determining interaction data using the image data, said interaction data identifying a page description corresponding to the printed substrate;
• a transceiver for:
• sending the interaction data to a computer system, thereby causing the computer system to identify the page description and retrieve display data corresponding to at least part of the printed substrate using the identified page description;
• and
• receiving the display data from the computer system;
• and
• an opaque touch-sensitive display screen for displaying display information based on said display data, said display information matching and aligning with printed content underlying said screen such that the opaque display screen has real-time virtual transparency through the screen to the printed content underlying said screen from a user's perspective to provide a virtual window to the printed content underlying said screen,
• wherein said device is configured such that a predetermined user interaction with the display information creates an association between one of said multimedia objects and the zone of the printed substrate, thereby causing the page description to be updated in accordance with said association, such that subsequent interaction with said zone of said printed substrate using said device causes retrieval of said multimedia object from said updated page description.