HP 1200 Service Manual - Page 73

Optional copier/scanner The optional copier/scanner consists of the optical system and the document pickup and feed systems. Optical system The optical system, also known as the contact image sensor, contains the following: ! light-emitting diode (LED) array ! contact glass ! rod lens array ! sensor array The light source has three LEDs and is controlled by the formatter. Light reflected from documents passes through the rod lens array and focuses on the sensor array. The sensor array consists of 5,160 phototransistors: 15 driver circuits amplify the light reception output in units of 344 phototransistors. The image data is converted and sent from the driver circuits to the formatter. Document pickup and feed systems The document pickup and feed systems contain a pickup roller, feed roller, and delivery roller, all of which are driven by the copier/scanner motor (M1). The document top sensor (U20) detects the top and bottom edges of the document. EN Optional copier/scanner 71