The present invention provides a rotary laser irradiating apparatus, which comprises a laser source, a rotator for forming a laser reference plane by rotary irradiation of a laser beam from the laser source, scanning gear for deflecting the laser beam from the laser source, and a controller for controlling...http://www.google.com.au/patents/US6435283?utm_source=gb-gplus-sharePatent US6435283 - Rotary laser irradiating apparatus and construction machine control system
