Question

What is the Laser Printing - What is laser printing??

Accepted Answer

A method of printing  this process creates an image by using static electricity to attract toner to specific areas of an imaging drum before it is transferred and bonded onto a substrate  Laser printing is a form of xerographic printing  a latent image is created first using a photoconductive drum  the image carrier or imaging device  and static electricity  but where xerography uses light to create a copy of a document on an image drum  laser printing uses a laser to project a digital image onto the image drum  meaning it is also a form of digital printing         There are typically seven steps involved  image processing  charging  exposure  development  transfer  fusing  and cleaning         While laser printers may be used to print original documents or copies of documents  it must always start with a digital image  A Raster Image Processor converts the document or image being printed into a raster image or  bitmap   the document or image is represented by a grid of pixels  points of colour   This bitmap is then sent to the printer for output         Next the photoconductive drum  image drum  is given a negative  or positive  charge by the primary charge corona roller or wire         Exposure involves the creation of a latent image  an    invisible    image that is created by exposing a photosensitive material to light   in laser printing  a laser scans across the image drum  turning on and off according to the bitmap to indicate if an area should show the  non-content   blank  white areas  or  content  of the image  When the light is on  the charge on that area of the drum is reversed or discharged  this creates a pattern of dots that are positively  or negatively  or neutrally charged and forms the latent image  which is a negative of the original         The latent image is then developed as the drum rotates past a toner cartridge  the toner particles have a negative  or positive  charge  meaning that they will either be attracted to the positively charged areas of the drum or repelled by the negatively charged areas of the drum and fall into the neutral areas         At this point  the substrate passes between the image drum and the transfer corona  the transfer corona gives the substrate a negative  or positive  charge that is stronger than that of the image drum  The toner is attracted to the paper and  because the paper has a stronger charge than the drum  is transferred onto the substrate         The substrate then passes through a fuser unit  which uses heat and pressure to bond the toner in place         In the final stage  light discharges the remaining charge on the drum  and any excess toner is brushed away in order to clean the drum before the next sheet is printed         Laser printers can use one colour of toner to create monochromatic images or use four toners to create full colour images through four colour process printing  each of the process colours has its own colour and its own bitmap  laser printers with one image drum will repeat the expose  develop  and transfer steps for each colour  while other laser printers will have one image drum per colour and a  transfer belt   which passes between each toner cartridge and image drum in succession before transferring the four layers of toner onto the substrate in a single step          Laser printers are able to produce high print resolution  at a quiet operating volume  and often at high speed

Lay Flat - What is lay flat?

Definition of LAY FLAT: