Patent ID: 8330714

Claim:
An electronic device, comprising: a projector device that projects an image formed by an optical image formation element with a projection range; an imaging device that captures an image with an imaging range so that the imaging range captured by the imaging device includes the projection range projected by the projector device and the imaging range is wider than the projection range, and outputs an image signal; an image change detection unit that detects change of the image signal in a plurality of regions in a range that is determined by excluding the projection range from the imaging range captured by the imaging device and located outside of the projection range where no image is projected by the projector device; a command unit that issues a different command for each of the plurality of regions in which changes are detected by the image change detection unit according to the region within the imaging range in which change has been detected by the image change detection unit, wherein each of the commands is related to operation of the projector device or an external device that is electrically connected to the electronic device; and a reception unit that receives an external signal outputted by the external device that is electrically connected to the electronic device, wherein: the command unit decides that the command according to change of the image signal is valid when the external signal is not being received via the reception unit and the command according to change of the image signal is invalid when the external signal is being received via the reception unit, in case that the change of the image signal has been detected by the image change detection unit.