Laser operated scanning and printing system

Claim 1

A combination printing and scanning system comprising: a. a laser for generating a linearly polarized beam of light, b. signal generating means for generating a series of binary signals representative of the information content of an image to be reproduced, c. beam deflection means for causing said beam of light to be directed selectively along one of two different paths in correspondence with the state of said binary signal, d. beam interception means for intercepting said beam when directed along one of said two different paths and permitting passage thereof when said beam is directed along the other of said paths, e. collimating means including first and second lenses for collimating said beam after passage by said interception means, f. support means for a graphic medium to be scanned or imaged, g. a third lens for focussing said collimated beam, directing said beam toward a point on said graphic medium, and collimating specular and diffused light reflected back from said point, h. scanning means for causing relative movement between said graphic medium and said point so that said point scans an entire working area within said graphic medium, i. polarizing means for circularly polarizing the collimated beam of light transmitted by said collimating means and linearly polarizing the circularly polarized specular light component of the light which is reflected back from said point and collimated by said lens means, j. filter means for filtering out from the collimated beam of light reflected back through said polarizing means the linearly polarized specular component thereof, k. focussing means for focussing the collimated beam of diffuse light passing through said filter means, l. a transducer placed at the image plane of said focussing means for generating an electrical signal related to the intensity of the focussed spot of diffuse light directed thereagainst, m. digitizing means for digitizing electrical signal and storing digital samples thereof, and n. selection means for selectively activating either said signal generating means and said beam deflection means or said digitizing means whereby said apparatus operates selectively either as a printing system or a scanning system.