Patent ID: 7497018

Claim:
An apparatus for projecting an indication of alignment, comprising: a housing, wherein the housing is dimensioned such that the apparatus can fit within the palm of a human hand; a projection unit pendulously suspended in the housing to project output beams to indicate level, plumb and square where the projection unit includes a vertical projection module and a horizontal projection module and where each of the vertical and horizontal projection modules include: a laser emitting diode to emit a laser beam directly incident on a collimator, the collimator comprising a single lens, the collimator configured to collimate the laser beam into a collimated beam and project the collimated beam on a planar reflective surface; a planar reflective surface orientated at an angle of approximately 45° to a path of the collimated beam projected from the collimator and configured to divert the path of the collimated beam approximately 90° and toward a partial-conical reflective surface; a conical reflective surface formed from at least approximately 180° of an exterior surface of a cone and configured to reflect the diverted collimated beam into an approximately 180° fanned output beam, where the conical reflective surface is positioned relative to the planar reflective surface such that a center of the collimated beam is incident on a front face of the cone and is not incident on the apex of the cone; where the vertical projection module generates a substantially vertical output beam and the horizontal projection module generates a substantially horizontal output beam, the vertical and horizontal output beams being projected from the housing in different but generally perpendicularly related directions, whereby the output beams can be used to indicate level, plumb and square alignment; and a damper to dampen pendular motion of the projection unit.