The present invention relates to laser leveling device suitable for
construction. The present invention uses a standard low cost laser diode
module as the laser source and optical system. A novel method is provided
to align the non-collimated beam emitted from the standard low cost laser
diode module so that it is perpendicular to the rotational axis of the
laser level. The present invention describes a laser level which can be
operated in four different modes: dot mode, line mode, oscillation mode
and plane mode. Dot mode provides two level laser dots. Line mode
provides a short bright level line. Oscillation mode provides a long
bright reference line. Plane mode provides a level 360 degree reference
plane. The invention also provides a structure which allows two vertical
reference planes which are perpendicular to each other and perpendicular
to the horizontal reference plane to be generated.