An alignment indication is provided in an optical scanner for reading a two-dimensional
optical code by varying the scanning beam to provide a region of apparent greater
brightness. In the case of a PDF417 bar code symbol, an elongated brighter region
may be oriented so that it is parallel with rows of the PDF417 symbol. The apparent
greater brightness may result because of the persistence of the scanning pattern
in the user's vision. The region of apparent greater brightness may be achieved
by providing a greater density of scan lines in the region. Because of the persistence
in the user's vision, multiple scan lines appear simultaneously, and thus a region
with a greater density of scan lines appears as a brighter region. The region of
apparent greater brightness may also be achieved by providing a differently shaped
scanning spot in the region (e.g., a larger, or more elongated spot). Greater scan
line density and differently shaped scanning spot may be combined to produce the
region of apparent greater brightness.