Patent attributes
An input unit arrangement for controlling an electronic device is provided. The arrangement comprises; a base; a position-coding pattern provided on the base and coding a first and second sets of absolute positions on spatially separate areas of the base, the first and second sets of absolute positions being mutually exclusive and coded by spatially separate first and second subsets of the position-coding pattern; a handheld image-recording device for recording images of the position-coding pattern; and a processor for deriving a position from the position coding pattern in the recorded image, the processor providing an instruction to the electronic device to perform a first function when the absolute position belongs to the first set, and a second function when the absolute position belongs to the second set. The arrangement enables a user to select different functions by selecting differing areas of the base on which the position-coding pattern is provided.