What does the fuser do in a laser printer?

How Does a Laser Printer Fuser Work?

• Answer:

  Raster Image Processor When a laser printer receives a document or graphic from a computer, the laser printer's Raster Image Processor (RIP) generates a bitmap, which is a line-by-line image of the document. The Image Drum Using the bid map as a template, a narrow laser beam, reflected by a mirror, flashes its light onto the image drum's photo receptive coating. Where the laser strikes, it creates a negative charge corresponding to one pixel of the white parts of the bitmap. The resulting static electric negative image attracts toner particles to the drum's surface as it rolls near the toner. Toner The rolling drum presses the toner---consisting of fine, dust-like particles of dry plastic powder mixed with carbon black or coloring agents---onto the paper. Some printers go a step further by adding a positively charged transfer roller behind the paper to "pull" toner from the image drum. Finally, The Fuser As a last step, the paper, now covered with loose toner, rolls between two heated rollers (the fuser rollers) each of which contains an electrically powered heating element. The fuser rollers are so hot they melt the plastic toner. The melted toner "fuses" with the fibers in the paper. Because of the "fusion" of plastic with paper, when the toner solidifies, it should not smear when touched. If it does, you will know you have a problem with the fuser in your laser printer.