LASER PRINTER Sandeep Bose 28-11-15 What is a printer An external hardware device responsible for taking computer data and generating a hard copy of that data. Printers are one of the most commonly used peripherals and they print text and still images on the paper. Printers Impact Printers Non-Impact Printers Daisy Dot- Inkjet Thermal Laser wheel Matrix 3 History 200 A.D. : Block printing evolved in China. 1040 : Movable type is the system of printing and typography using movable pieces of metal type, made by casting from matrices struck by letterpunches. 1439: Johannes Gutenburg made printing press. 1796: Invented by Aloys Senefelder, lithography is a method for printing on a smooth surface. 1818: Chromolithography or colour printing were developed. 1870: Offset printing. 1907: Screen printing. 1938: Introduction of xerograpy/photocopier. 1951: Inkjet printing 1957: Dye-sublimation printing 1968: Dot-matrix printing 1969: Laser printing 1972: Thermal printing 1984: 3D-printing 1993: Digital printing Principle 1. Controller Before a laser printer can do anything else, it needs to receive the page data and figure out how it's going to put everything on the paper. It is the job of the controller. 2. Rotating drum/imaging drum A photoconductor is a specially coated cylinder that has a positive or negative charge on it. 3. Charging roller It sends positive or negative to the rotating drum. 4. Laser 5. Rotating mirror 6. Developer roller It is coated in charged toner particles from toner cartridge. 7. Tonner hopper Part of toner cartridge feeds the toner particles into the developer roller. 8. Transfer roller Draws paper from the paper tray. 9. Paper tray 10.Transfer roller Applies charge opposite to the toner’s to the paper 11. Cleaning blade Cleans the drum 12. Fuser Heat roller and pressure roller melts the toner onto the page. Advantage High resolution High speed. High quality graphics images. Disadvantage Certain gases like carbon monoxide, ozone, nitrogen oxide are produced which affects human health. Ultraviolet light can cause eye damage..