Patent attributes
An accessory that can be connected to a machine drill is provided. A projector is provided to project a first light spot and a second light spot to a work piece to be processed. A camera is provided to record the first light spot and the second light spot in an image. A processing device is provided to determine an incline of the machine drill in reference to the work piece, based on a first distance of the first light spot from a reference point recorded in the image and a second distance of the second light spot from the reference point recorded in the image. A display device is coupled to the processing device and displays the determined incline. The light spots may be embodied punctual or planar.