INFORMATION PROJECTION METHOD AND DEVICE AND LASER PROCESSING DEVICE

The present invention provides an information projection method in which information about a cut piece that has been cut and separated from a sheet-shaped workpiece and placed on a mounting base is projected onto the cut piece or a position close to the cut piece, wherein: in order to match the aspect ratio (vertical/horizontal ratio) of a projector (21), the long side of a workpiece (W) is assigned to the X axis direction, which is the horizontal direction in the aspect ratio, the short side of the workpiece (W) is assigned to the (Y) axis, which is the vertical direction in the aspect ratio;positional relationship d for the upper surface of the workpiece (W) and the projector (21) is found on the basis of sheet thickness information of the workpiece (W) on a mounting base (7, 9) positioned in correspondence with the projector (21) provided in a prescribed position in the Y axis direction; and information about the cut piece is projected onto the cut piece or a position near the cutpiece with an enlargement