6 - 5Chapter 6 Principle of Operation2. Flow of Print DataThe NIC (Network Interface Card) of the printer connected with a network receives a packet signal in abit stream from a client or server of the network, and decomposes the packet signal received next intoa data format adapted for a layer from which the data is sent to the Controller. The Controller processesthe data from the NIC by the same method as for data received from the host computer via a parallelport. (These two types of data are referred to as host data.)PWBA ESS acts to buffer the rasterized bit-image host data or converts host data in PDL (PageDescription Language) into rasterized bit-image data. The PWBA ESS sends each line of the rasterizedbit-image data to the MCU of the HVPS/MCU whenever the laser beam makes a scan.This signal carrying image data (/VDO signal) is converted into LVDS signal by the MCU of the HVPS/MCU, and is sent as XP.DATA+ and XP.DATA- signals to the ROS ASSY, where the signal isconverted into a laser beam. The beam is emitted with a quite small diameter. The beam is turned ONand OFF according to the video signal. The laser beam is reflected off the surface of a rotating polygonmirror, so that the beam is concentrated to the surface of the drum of the EP CARTRIDGE by a seriesof lenses. As a result, an electrostatic latent image is created on the drum surface.Print data (electrical signal) from the printer controller is converted into a print image through thefollowing flow.Host (electrical signal)Printer controller (electrical signal)MAIN PWB (electrical signal)ROS ASSY (laser beam)Latent image on drum (invisible)Toner image on drum (visible)Toner image on paperPrint image on paperJG6105AA
