Electro-optical communication of visual images

Claim 1

In transmitting or receiving apparatus for use in electro-optical communication of visual images such as photographs, documents, or the like, said apparatus including a light source, circuitry for carrying electric signals corresponding to the modulation of said light source, means defining a field to be scanned, and an optical system for causing a light beam from said source to focus upon and scan said field, said optical system including a substantially flat reflector movable about a scanning axis to effect said scanning, the locus of beam positions of light reflected from said reflector upon movement about said axis defining a scanning surface having an intersection with said field to define a scan line, that improvement comprising arrangement of said source and said optical system so that said light beam is incident upon said reflector along a path forming an acute angle with said scanning surface, and arrangement of said reflector and said means defining said field so that said axis is tilted with respect to the surface of said reflector and toward said scanning surface from the side thereof on which said beam is incident upon said reflector, said axis being so tilted at an angle relative to said reflector surface substantially equal to said acute angle, said axis thereby forming an angle of less than 90* with said scanning surface, said arrangement producing a predetermined approximation of planarity of said scanning surface and a corresponding predetermined approximation of straightness of said scan line independent of the angle through which said reflector is moved about said scanning axis.