TallyGenicom 9045N, Руководство по обслуживанию

Страница: 516 / 617

6 – 6
Chapter 6 Principles of Operation
2. Flow of Print Data
The NIC (Network Interface Card) of the printer connected with a network receives a
packet signal in a bit stream from a client or server of the network, and decomposes
the packet signal received next into a data format adapted for a layer from which the
data is sent to the Controller. The Controller processes the data from the NIC by the
same method as for data received from the host computer via a parallel
port. (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 (Page Description
Language) into rasterized bit-image data. The PWBA ESS sends each line of the
rasterized bit-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 is converted into a laser beam. The beam
is emitted with a quite small diameter. The beam is turned ON and OFF according to
the video signal. The laser beam is reflected off the surface of a rotating polygon
mirror, so that the beam is concentrated to the surface of the drum of the EP
CARTRIDGE by a series of 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 the following flow.