Laser Printer Printing Process

Front 1

Cleaning

Back 1

1. Rubber blade removes excess toner from the drum. An erasing lamp removes any leftover charge on the drum bringing it to 0 volts.

Front 2

Conditioning

Back 2

2. Also known as charging.A negative charge is applied to the drum by the primary corona wire, which is powered by a high-voltage power supply within the printer

Front 3

Writing

Back 3

3.Also known as exposing. The laser is activated and "writes" to the drum as it spins. Where the laser hits the drum, it dissipates the negative charge toward the center of the drum and is grounded. The "written" areas of the drum now have a lesser negative charge.

Front 4

Developing

Back 4

4. The surface of the drum that was previously exposed to the laser is now applied with negatively charged toner. This toner has a higher charge than the areas of the drum that were written to.

Front 5

Transferring

Back 5

5.The toner, and therefore the the text or image, is transferred to the paper as the drum rolls over it. On many laser printers, the paper, the paper slides between the drum and a positively charged corona (known as the transfer corona wire). The transfer corona wire applies the positive charge to the paper. Because the paper now has a positive charge , and the toner particles on the drum have a negative charge, the toner is attracted to the paper. When it comes to voltages opposties attract. In many printers the paper passes by a static elimination device (often a strip) which removes excess charge from the paper.

Front 6

Fusing

Back 6

6.The toner is fused to the paper. The paper passes through the fusing assembly that includes pressurized rollers and a heating element that can reach approximately 400 degrees F