Method of translating printed text using handheld display device

A method of translating printed text using a handheld display device having an image sensor, a transceiver and an opaque touch-sensitive screen, said method comprising the steps of:

• overlaying said device on part of said printed substrate;
• imaging an area of a printed substrate containing printed text in a first language and generating image data using the image sensor;
• determining interaction data using said image data, said interaction data identifying a page description corresponding to the printed substrate;
• sending the interaction data to a computer system, thereby causing the computer system to identify the page description and retrieve display data corresponding to said printed text translated into a second language;
• receiving the display data from the computer system;
• displaying, on said opaque touch-sensitive screen, display information based on said display data, said display information comprising displayed text corresponding to said printed text translated into said second language, said displayed text being aligned with the printed text underlying said screen, such that the opaque touch-sensitive 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.