Muratec F-110 Field Engineering Manual page 60

Circuit Description
4-4 Engine PPA
4-4-1 Engine Configuration
4-4-1-1. Video Controller Board
Video Controller Board receives image data from the host computer and converts it into bitmap (binary) image or receives
bitmap image directly from the host computer and sends it to the engine controller board.
4-4-1-2. SMPS Board
It basically receives AC input and generates ripple-free DC level +5V and -5V +24V. Next, it supplies these voltages to each
unit appropriately.
It also supplies AC power to heat lamp of fixing unit.
4-4-1-3. HVPS Board
HVPS board generates high voltages of THV/MHV/Supply/Dev and supplies them to the developing unit to create images. It
is designed to realize optimum conditions for the images.
This board includes LSU interface unit and cover open sensing unit that it intercepts +24V voltage to the main motor, LSU, fan,
clutch and fixing unit when you open the front cover.
4-4-1-4. Developer
Using the digital picture process, developing unit generates visible images. It is comprised of charge roller, OPC drum, devel-
oper roller, supply roller and toner.
4-4-1-5. LSU (Laser Scanning Unit)
This is controlled by engine controller. Using laser beam control, exposure of OPC drum and the rotational principle of polygon
mirror, it forms electro-static latent image in the OPC drum with the video data received from engine. It is the core part of LBP .
OPC drum synchronizes with the feeding speed of the paper and rotates. When the laser beam inside LSU reaches at the end
of polygon mirror, it generates /HSYNC signal and send it to engine. Then the engine detects /HSYNC signal and adjusts the
lengthwise row of the image on the paper. After detecting /HSYNC and after set time period, it sends the video data to LSU to
adjust the left margin on the paper.
The one side of the polygon mirror is the one line scanned.
4-4-1-6. Transfer
Transcribing unit is comprised of PTL(pre-transfer lamp) and transcribing roller. PTL detects the beam of the OPC drum, low-
ers the electric potential of the developing unit and lower the adhesiveness of toner to enhance transcription coefficient.
And the transcribing roller transfers the toner (constituting element of video image) on OPC drum to the paper.
4-4-1-7. Fixer
It is comprised of heat lamp, heat roller, pressure roller, thermistor and thermostat. It fixes the toner powder transferred to the
paper on the paper using pressure and high heat in order to finish the final printing job.
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