Laser printer facts for kids

The Apple LaserWriter Pro 630 was one of the first laser printers

A laser printer is a printer for computers. It uses LED-technology to get small particles of toner from a cartridge onto paper. Very often, this is more economical to use than the ink of inkjet printers.

The laser printer was first invented by a team at Xerox in 1969.

Process

Laser printing is a process which typically involves seven steps:

1. Charging: An electrostatic charge is then projected onto a revolving photosensitive drum inside the printer.
2. Writing: A laser beam is directed at a rotating polygonal mirror, which redirects the beam onto the photosensitive drum. The rasterized data in memory is now read, and used to control whether the laser is on or off, as the beam sweeps across the drum - where the laser beam strikes the drum the charge is reversed, creating a latent electrical image on the surface.
3. Developing: The surface of the drum is then exposed to negatively charged particles of toner, which are attracted to the areas where the laser wrote the latent electrical image. The toner will be repelled by the negative charge on areas of the drum where the laser beam did not strike, and hence remove the charge.
4. Transferring: The drum is now rolled over paper, transferring the image from the drum to the paper (to aid in this process there is a positively charged roller behind the paper, which pulls the toner off the drum and onto the paper).
5. Fusing: The paper is then passed through a fuser, where rollers provide heat and pressure to bond the toner to the paper.
6. Cleaning: An electrically uncharged blade and a discharge lamp remove any toner and all the charge remaining on the drum (this will all happen in one revolution of the drum).

Images for kids

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  HP LaserJet 4200 series printer, installed atop additional 500-sheet paper tray

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  Gary Starkweather (seen here in 2009) invented the laser printer.

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  Laser unit from a Dell P1500. The white hexagon is the rotating scanner mirror.

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  Magnification of color laser printer output, showing individual toner particles comprising 4 dots of an image with a bluish background

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  Fuji Xerox color laser printer C1110B

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  Small yellow dots on white paper, generated by a color laser printer, are nearly invisible. (Click to see higher-resolution image)

See also

In Spanish: Impresora láser para niños