Process and apparatus for high speed laser printing using a roller having a convertible structure

An apparatus for carrying out a laser printing process, comprising:

• a rotary light sensitive roller;
• a means for rotating said light sensitive roller;
• a toner distributing means co-operating with said light sensitive roller, means for advancing a band along a trajectory to co-operate with said rotary light sensitive roller in order to be printed;
• a rotary memory roller;
• a means for rotating said memory roller;
• a layer of a memory material covering a surface of said rotary memory roller, said memory material being convertible into either an amorphous or a crystalline structure under the action of a laser beam, and said memory material showing a high difference in reflecting ability according to whether it assumes the one or the other of said structures;
• a first laser beam emitting device including a first laser source;
• a computer controlling said first laser source and a first optical system arranged for forming onto said rctary memory roller an image to be printed;
• a transfer device including a second laser source of a second laser beam, which is linear in its whole, a second optical system arranged for focusing said second laser beam onto a generatrix of said rotary memory roller, from which they are reflected;
• and
• a third optical system arranged for projecting onto a generatrix of said light sensitive roller the laser beams reflected by said generatrix of said rotary memory roller onto which said second laser beam has been focused.