Reading head for document scanning e.g. for photocopier

摘要

The reading head includes the fixed bar extending along the area to be read which corresponds to the width of paper (P) to be copied. The cross-section of the bar includes a central region (2) with a flat lower surface (3) which faces a mobile carriage (4) containing photosensitive transistors or diodes (5). The central region upper surface (6) is convex and faces the document to be copied.The two symmetrical prism regions (7) are on either side of the bar and internally reflect light which is carried along the bar before emerging and illuminating the document. Specific surfaces (9) of the prisms are un-polished or formed of microprisms.