Multi-paned polygonal lighthouse assembly with improved corner configuration

摘要

A multiple pane lighthouse assembly in a reference laser beam projecting apparatus includes a plurality of transparent panes disposed in an arrangement that defines a transparent window structure which permits transmission of laser light therethrough and has a generally polygonal cross-sectional shape. The window structure has spaced corners formed by pairs of adjacent ones of the opposite side edge portions of the panes. The side edge portions of the panes in each pair are offset relative to one another in forming a respective corner. The offset position of the side edge portions of each pair in forming a respective corner exposes only an interior edge on one of the adjacent side edge portions to laser light being transmitted through the window structure. The path of laser light through the adjacent side edge portions forming the corner is thereby affected only by one interior edge on the respective one of the adjacent side edge portions of the panels at each corner. The offset relationship also provides for the placement of adhesive to bond the side edge portions together in the shadow area of laser light being transmitted through the corner.