Apparatus and method for laser scanner cleaning and protection

An air guard for reducing surface contamination of a viewing window of an optoelectronic presence sensing device, the air guard comprising:

• a body section generally conforming to a contour of the viewing window;
• first and second chambers formed within the body section, each configured to receive pressurized air from an external source;
• one or more slits formed in the body section and configured to vent pressurized air from the first chamber in a curtain like flow in front of the viewing window;
• and
• one or more nozzles formed in the body section and configured to vent pressurized air from the second chamber in one or more generally focused air streams directed toward the viewing window.

A method of maintaining a viewing window of an optoelectronic presence sensing device with respect to window contamination, the method comprising:

• providing an air guard proximate to the viewing window;
• supplying the air guard with pressurized air;
• and
• selectively operating the air guard in a preventive mode wherein it vents the pressurized air in a generally laminar flow in front of the viewing window to prevent airborne contaminants from settling thereon, and in a cleaning mode wherein it vents the pressurized air in one or more directed air streams toward the viewing window to remove deposited surface contaminants thereon.