1. An area identifying device comprising: a projecting unit configured to project a pattern so that the pattern performs a predetermined movement; an image capturing unit configured to capture, in sequential order, multiple images of an area on which the pattern is projected, the image having a plurality of areas; a calculating unit configured to calculate an amount of change of pattern appearances for each region in the multiple images; and an identifying unit configured to identify, as a reflective area, at least one area having a different amount of change of the pattern appearances from a reference amount of change of the pattern appearances based on the predetermined movement, among the amounts of change of the pattern appearances that are calculated by the calculating unit.