laser lines

[Doug J]

I have been looking at some machines in the local DIY store which generate a laser line for ease of use. I could'nt work out how they produce a line with a laser. Is the laser rotated or is the beam rotated with a moving mirror? Does anybody know?
Doug

[alanstepney]

I was playing with one a couple of weeks ago, and that had a prism which was in a rotating housing, and reflected (I guess it should be refracted) the light.

I dont know if all are like this, but it seems a simple way to achieve the objective.