Multi-beam polygon scanning system

A polygon scanning system comprising:

• a polygon having a reflective facet;
• a rotation mechanism for rotating the polygon;
• and
• a light source for directing a plurality of light beams to impinge on the facet such that each light beam impinges on the facet at substantially the same incident location, at an incident angle different than the incident angles of the other light beams, and each light beam is reflected by the facet to scan a respective portion of a surface of a substrate during a respective time interval when the rotation mechanism is rotating the polygon;
• wherein the facet has a total surface area, and each of the plurality of light beams is reflected onto the substrate surface using a respective portion of the facet surface;
• wherein the sum of the respective portions of the facet surface used to reflect the light beams is greater than 90 percent of the total surface area.

A method comprising:

• rotating a polygon having a reflective facet from a leading edge of the facet to a trailing edge of the facet once ner revolution of the polygon;
• directing a first light beam to impinge on an incident location on the facet at a first incident angle such that a first light beam is reflected by the facet to scan a first portion of a surface of a substrate during a first time interval while the polygon is rotating between the leading edge and the trauma edge of the facet during a first revolution of the polygon;
• and
• directing a second light beam to impinge on the facet at substantially the incident location, at a second incident angle such that a second light beam is reflected by the facet to scan a second portion of the surface of the substrate during a second time interval subsequent to the first time interval while the polygon is rotating between the leading edge and the trailing edge of the facet during the first revolution of the polygon.

A method comprising:

• rotating a polygon having a reflective facet;
• and
• directing a plurality of light beams to impinge on the facet at substantially the same incident location, such that each light beam impinges on the facet at an incident angle different than the incident angles of the other light beams, and each light beam is reflected by the facet to scan a respective portion of a surface of a substrate during a respective time interval while the polygon is rotating;
• wherein the facet has a total surface area, and each of the plurality of light beams is reflected onto the substrate surface using a respective portion of the facet surface;
• wherein the sum of the respective portions of the facet surface used to reflect the light beams is greater than 90 percent of the total surface area.