Document scanner system

The document scanner system consists of the optical system and document pickup and feed systems.

The optical system, also known as the contact image sensor, contains the following:

light-emitting diode (LED) array

contact glass

rod lens array

phototransistor array

The LED array, which emits light from two types of LEDs, is controlled by the formatter. The contact glass refracts the light to documents. Light reflected from documents passes through the rod lens array to the phototransistor array.

The phototransistor array consists of 2,574 phototransistors: 11 driver circuits that amplify the light reception output in units of 234 phototransistors. The image data is converted and sent from the driver circuits to the formatter.

The document pickup and feed systems contain a pickup roller, a feed roller, and a delivery roller, all of which are driven by the document scanner motor. There are also two photosensors in the document path. PS801 detects the presence of a document and PS802 detects the leading edge of a document.

EN

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HP 3150, 3100 manual Document scanner system