Thursday, November 27, 2008

Printers: What Really Happens When You Hit “Print”

by: Bill Smith

You just poured hours upon hours into a lengthy research paper. All that’s left to do is print it out. And that’s the easy part, right? Sure looks easy from the user perspective, but it’s actually quite complicated. A series of critical processes kick off as soon as you kit the OK button.

The first thing that happens is your software application (MS Word, Excel, etc) sends the data you want to print to your printer driver. The printer driver is nothing more than some software that translates data into a format that your specific printer can understand. When you buy a new printer, it generally comes with a CD. On that CD is the printer driver software you need to enable your specific printer to talk to your computer.

The printer driver takes the translated data and physically sends it along to your printer. It’s able to connect to the printer via the USM connection interface. Much of the data received by the printer goes directly into the printer buffer, where it is stored. By storing the data within the printer itself you’re able to finish the print job quickly.

If you just turned your printer on for the first time in a while or if the printer has been standing idle for a while, the printer will run through a series of diagnostic tests. Some of these tests check he availability of ink, while others clean the print heads.

Once this preprinting step completes, your printer brain sends a message to the paper stepper motor telling it to engage the rollers and feed paper into the printer body. As the paper is being fed into the machine, the belt pulls the print head into “ready” position. When the paper is perfectly positioned, the print head goes to town, firing droplets of ink at the paper. With incredible speed and accuracy, the print head travels back and forth across the page spewing colors. When it reaches the end of the page, the stepper is quickly engaged, advancing the paper forward. This process continues until the print job is complete.