In an image scanner, a lens position control mechanism and method converts a reading line density by changing over lenses. A base rotatable in a plane parallel to an original table is provided, and the lenses are supported on the base so that their optical axes are in a plane parallel to the base surface...http://www.google.es/patents/US5535040?utm_source=gb-gplus-sharePatente US5535040 - Lens changeable image scanner and lens position control device in the same
Lens changeable image scanner and lens position control device in the same
