Laser printer pdf

Download Download PDF. Translate PDF. How Laser Printers Work by Tom Harris The term inkjet printer is very descriptive of the process at work -- these printers put an image on paper using tiny jets of ink. The term laser printer, on the other hand, is a bit more mysterious -- how can a laser beam, a highly focused beam of light, write letters and draw pictures on paper?

In this article, we'll unravel the mystery behind the laser printer, tracing a page's path from the characters on your computer screen to printed letters on paper. As it turns out, the laser printing process is based on some very basic scientific principles applied in an exceptionally innovative way. The Basic Process Hewlett Packard LaserJet T The primary principle at work in a laser printer is static electricity, the same energy that makes clothes in the dryer stick together or a lightning bolt travel from a thundercloud to the ground.

Static electricity is simply an electrical charge built up on an insulated object, such as a balloon or your body. Since oppositely charged atoms are attracted to each other, objects with opposite static electricity fields cling together.

The basic components of a laser printer A laser printer uses this phenomenon as a sort of "temporary glue. This drum assembly is made out of highly photoconductive material that is discharged by light photons. Initially, the drum is given a total positive charge by the charge corona wire, a wire with an electrical current running through it.

Some printers use a charged roller instead of a corona wire, but the principle is the same. As the drum revolves, the printer shines a tiny laser beam across the surface to discharge certain points. In this way, the laser "draws" the letters and images to be printed as a pattern of electrical charges -- an electrostatic image. The system can also work with the charges reversed -- that is, a positive electrostatic image on a negative background.

The laser "writes" on a photoconductive revolving drum. After the pattern is set, the printer coats the drum with positively charged toner -- a fine, black powder. Since it has a positive charge, the toner clings to the negative discharged areas of the drum, but not to the positively charged "background. With the powder pattern affixed, the drum rolls over a sheet of paper, which is moving along a belt below.

Before the paper rolls under the drum, it is given a negative charge by the transfer corona wire charged roller. This charge is stronger than the negative charge of the electrostatic image, so the paper can pull the toner powder away. Since it is moving at the same speed as the drum, the paper picks up the image pattern exactly. To keep the paper from clinging to the drum, it is discharged by the detac corona wire immediately after picking up the toner.

Finally, the printer passes the paper through the fuser, a pair of heated rollers. As the paper passes through these rollers, the loose toner powder melts, fusing with the fibers in the paper. The fuser rolls the paper to the output tray, and you have your finished page. The fuser also heats up the paper itself, of course, which is why pages are always hot when they come out of a laser printer or photocopier.

So what keeps the paper from burning up? Mainly, speed -- the paper passes through the rollers so quickly that it doesn't get very hot. After depositing toner on the paper, the drum surface passes the discharge lamp.

This bright light exposes the entire photoreceptor surface, erasing the electrical image. The drum surface then passes the charge corona wire, which reapplies the positive charge. Conceptually, this is all there is to it. Of course, actually bringing everything together is a lot more complex. In the following sections, we'll examine the different components in greater detail to see how they produce text and images so quickly and precisely.

The 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.

This is the job of the printer controller. The printer controller is the laser printer's main onboard computer. It talks to the host computer for example, your PC through a communications port, such as a parallel port or USB port. The controller may have to start and stop the host computer periodically to process the information it has received.

A typical laser printer has a few different types of communications ports. In an office, a laser printer will probably be connected to several separate host computers, so multiple users can print documents from their machine. The controller handles each one separately, but may be carrying on many "conversations" concurrently.

This ability to handle several jobs at once is one of the reasons why laser printers are so popular. For the printer controller and the host computer to communicate, they need to speak the same page description language. In earlier printers, the computer sent a special sort of text file and a simple code giving the printer some basic formatting information.

Since these early printers had only a few fonts, this was a very straightforward process. These days, you might have hundreds of different fonts to choose from, and you wouldn't think twice about printing a complex graphic. The first page is printed within just 6 seconds.

But that doesn't make it the lowest quality printer. It is all about preferences. And the HP has fast speed and high-quality text and graphics output. The downside is that the paper capacity is set at just sheets. It also has great connectivity options. You can connect through wired and wireless networks, and you can also use NFC and cloud services. Mobile printing is supported as well. When you connect the printer to an internet network, you can take advantage of the HP Web apps, which makes the difference between a good and great printer.

Connecting to the web allows you to print websites easily. The printer speed is 19 pages per minute for both color and black and white pages. In contrast, here we have the most expensive printer on the list. And the price tag is certainly high for an inkjet printer. But where this printer excels is print size. You can use it to print tabloid-sized documents. And no matter the size, the image quality stays top-notch as well.

For all the capabilities it offers, the Epson printer is actually good value. The paper capacity is set at sheets, 80 of which go to the multipurpose feeder. Review the configured settings, and then click Finish to complete the setup. Step one: Load documents in the ADF.

Step two: Determine the method to send and save the scanned file. Step three: Enable the Scan to File settings. Step two: Determine the method to send and save the scanned file Use one of the following methods to scan and send the file. E-mail Follow these steps to scan a document using the E-mail menu:. On the control panel, touch E-mail. Touch the To: text box to type the email address.

Type the information in the Subject: and File Name text boxes. Touch the More Options arrow at the bottom of the screen to change the settings of the document. Original Sides Notification settings. Figure : Scan to Multiple Files using the E-mail menu. On the control panel, touch the Administration menu. Touch the More Options arrow at the bottom of the screen to configure the required settings of the document.

Touch the down arrow to access Page 3 and select the Scan to Multiple Files setting. Figure : Scan to Multiple Files setting. Select a location. Europe, Middle East, Africa. Asia Pacific and Oceania. Select a language. Confirm Back. Search all support. Search help. Tips for better search results Ensure correct spelling and spacing - Examples: "paper jam" Use product model name: - Examples: laserjet pro p, DeskJet For HP products a product number.

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