A scribing tool for use in semiconductor scribing apparatus includes a rotatable semiconductor wafer scribing wheel engageable with the semiconductor wafer to form a scribe line when the tool exerts pressure on the semiconductor wafer and the scribing wheel rotates. The method may include receiving a periodic digital signal at a first frequency in the form of a stream of digital data values, randomly inverting at least one of the digital data values and converting the stream of digital data values to a stream of analog data values to form an analog drive signal. A spring configured to apply a compressive force to the fuel cell stack is disposed between a first spring plate and a second spring plate. An eccentric axle of the eccentric wheel is penetratingly disposed in an axle hole in front of the eccentric wheel seat. The column direction and the second virtual linear lines define an angle of 2-40 degrees, and the dummy wiring layers are disposed in a manner to be located on the second virtual linear lines. The projector may include a light source lamp, a light beam dividing optical element, a polarization conversion element, a polarization selection element having a polarization selection surface, and an electro-optical device.