| 摘要 |
The transmitter has a generally flat, circuit board stator, a rotor including a plurality of magnets mounted in a ring around a central opening, and a bearing, supporting the rotor for rotation about an axis that extends through the central opening, A pentaprism assembly including an optics holder is mounted on the rotor for rotation therewith. The pentaprism assembly receives a beam of laser light through the central opening and redirects at least a portion of the laser light outward in a direction normal to the rotation axis. A laser source, mounted on the stator, provides a beam of laser light through the central opening to the pentaprism assembly. The beam of laser light is aligned with the rotation axis. The laser source includes a collimating lens positioned within the rotor. A shield plate of magnetic material beneath the stator exerts a force on the rotor in conjunction with the magnets, taking play out of the bearing. The transmitter uses Hall effect sensors on the stator to control switching current to coils on the stator. The transmitter also uses the outputs of the Hall effect sensors and a timer output to control dithering of the laser beam.
|
