What Is a Laser Printer

You must have heard the names of two types of printers. They include – inkjet printer and laser printer. Inkjet printers are those which print the image on paper with the help of tiny jets i.e. circles of ink. But do you know what laser printers are? Laser printers are a bit more advanced than inkjet printers and use a more advanced technology. Laser printers use the laser beams to print letters and to draw pictures on paper. They use highly monochromatic and coherent beam of light to do so. Let’s find out how.

The basic principle of laser printer is based on the concept of static electricity. Static electricity is the small amount of electricity that develops when charges are not in motion i.e. static. Static electricity basically refers to the accumulation of the charge at an insulated object. This is the same phenomenon that charges the bits of paper when rubbed on hair. This phenomenon serves as the temporary glue. Laser printer consists of a photoreceptor and drum assembly. Photoreceptor is basically a revolving cylinder or a drum. Positive charge is initially given to the drum. Charge is being transferred by the charge corona wire. Charge corona wire is basically a wire having electric current in it. With external force, as the drum is made to revolve, a tiny laser beam is made to shine by the printer. As this is done, certain points are discharges and this leads to the printing of letters and pictures.

When this assembly works fine, drum is coated with black powder by the printer. This is called as toner. Toner is positively charged and the drum is negatively charged, toner gets stick to the negatively charged portions of the drum as opposite charges attract each other. The background which is positively charged doesn’t get attracted by the toner as like charges repel each other.

Now this drum is made to roll over the blank sheet of paper. Paper is given negative charge before it comes in contact with the drum by the corona wire. Since paper is more negatively charges, it pulls up the black toner from the drum and the same image is formed on the paper as the toner get cling to the paper at the same positions which were preoccupied by the toner on the drum. Then the paper is made to pass through heated rollers. As this is made to pass through the rollers, loose toner powder gets melt. And after this, paper is sent out by the try attached. In this way, laser printer is able to form images.