How do xerox machines work

The final process involves heat to fix the toner to a sheet of paper. The process starts when the document is placed onto the glass. The copier scans the surface of the glass the bright light. The light bounces off the white parts of the original document, and through mirrors, it is reflected onto the drum, which has been given a positive electrical charge. The drum is surrounded by a photoreceptive layer or special coating that conducts electricity when light falls onto it.

Where the light falls the white parts of the original document , the drum conducts, and the electrostatic charge is lost. Where there is no light the black parts of the document , the drum does not conduct and maintains its positive charge. An image is produced onto the surface of the drum, but the image is made up of positively charged static electricity. A photocopier gets its name from the process of light that produces the copy of the image. The toner is a black powder which is also charged by the machine.

This time the charge is a negative one. The negative toner is drawn from the cartridge and attracted to the positive parts of the drum, which correspond to the black parts of the original document. You now have a drum with an image made up of black fine toner powder, which is a perfect replica of the original document. It now needs to be transferred to the paper. The drum now rolls onto a heated sheet of paper.

The toner powder transfers onto the sheet with the heat and becomes fixed into place, which is appropriately called 'fixing'. When the sheet of paper with its photocopied image rolls out of the machine, it still feels warm from the final part of the process. Copiers that work like this are essentially using analog technology: they scan an original document and reproduce it-using nothing more than optics and static electricity-as a faithful copy.

From , when the very first Haloid Xerox photocopier went on sale, to the early s, all copiers worked this way.

Everything changed in when Ricoh patented a crude digital photocopier. The first digital copiers from Ricoh, and later Canon , went on sale several years later. Today, analog copiers are essentially museum pieces and most copiers work digitally: they scan a document using an image-sensor chip CCD or CMOS , create a digital version typically a JPG or TIFF file , and then print that digital image in the same way as an inkjet or laser printer. Since they scan very hi-resolution digital images, they can reproduce with the same resolution as a high-end laser printer several times better than an analog copier.

Once a document is in digital form, it's easy to enlarge or reduce it by any amount. Digital copiers also produce "cleaner" copies with better control of the image density and contrast than analog copiers. You can think of a digital copier as a combined scanner and printer, coordinated by a built-in computer; and, indeed, the popular all-in-one print, scan, copy, and fax machines you can buy for home offices work just like this, with separate scanning, printing, and faxing "modules" hooked together.

They start with a digital image either a document you've scanned, fax from a phone line, or something received from a computer through a USB cable or wireless connection-Wi-Fi Direct or Bluetooth , store it, and then print it. Some digital machines allow limited editing of documents before they're printed. Some let you save documents for printing again later without the need to rescan them on a built-in hard drive, flash drive, or SD card.

Copiers with memories also make it much easier to duplicate complex, multi-page documents without the need to scan any of the pages more than once. If they have hard drives, the documents they process are usually stored there, which can create a security risk: even when documents are deleted, recoverable traces can be left behind. Some copiers use encryption to get around this, while others take pains to erase documents from their hard drive more thoroughly and securely.

As with any big piece of machinery, there are certain health and safety precautions to remain aware of throughout the life of the copier.

By following the tips below, you can extend the life and effectiveness of your machine for years to come. You should ensure that your copier has plenty of space around and, if up against a wall, that the ventilation shafts have room to expel air.

If the copier room is small or the office not particularly well ventilated, then we suggest using electric fans to keep a cool and steady temperature. Following on from ventilation, you should also ensure that your copier is placed at a suitable height. For example, a balloon charged with static electricity will attract small bits of paper or particles of sugar very easily. The drum , or belt, is made out of photoconductive material. Here are the actual steps involved in making a photocopy:.

When the copier illuminates the sheet of paper on the glass surface of a copier, a pattern of the image is projected onto the positively charged photoreceptive drum below. Light reflected from blank areas on the page hits the drum and causes the charged particles coating the drum's surface to be neutralized. This leaves positive charges only where there are dark areas on the paper that did not reflect light. These positive charges attract negatively charged toner. The toner is then transferred and fused to a positively charged sheet of paper.

If you take a photocopier apart, you might be overwhelmed by how many different parts there are. However, the actual photocopying process relies on only a few, key pieces:.

Sign up for our Newsletter! Mobile Newsletter banner close. The powder is negatively charged, and so it is attracted to something positive — the paper. The drum, which is located in the heart of a photocopier, is positively charged using static electricity. An image of the master copy is transferred onto the drum using a laser. The light parts of the image the white areas on a piece of paper lose their charge so become more negative, and the black areas of the image where the text is remain positively charged.

The toner being attracted to the positive areas sticks to the black areas of the image on the drum. For colour copies, the drum attracts the cyan, magenta and yellow and black toner. From these 4 colours, a wide spectrum of colours can be formed. The resulting toner on the drum is transferred to a piece of paper, which has a higher negative charge than the drum.

The xerographic process, which was invented by Chester Carlson in and developed and commercialized by the Xerox Corporation, is widely used to produce high-quality text and graphic images on paper. Because Xerox marketed the first plain-paper copiers, photocopying machines made by other companies are sometimes referred to as "Xerox machines" by those who dont realize its a misuse of the companys trademark.

In addition, the xerographic process is actually used to make both copies and prints. Carlson originally called the process electrophotography. Its based on two natural phenomena: that materials of opposite electrical charges attract and that some materials become better conductors of electricity when exposed to light. Carlson invented a six-step process to transfer an image from one surface to another using these phenomena. First, a photoconductive surface is given a positive electrical charge.

The photoconductive surface is then exposed to the image of a document. Because the illuminated sections the non-image areas become more conductive, the charge dissipates in the exposed areas.

Negatively charged powder spread over the surface adheres through electrostatic attraction to the positively charged image areas. A piece of paper is placed over the powder image and then given a positive charge.

The negatively charged powder is attracted to the paper as it is separated from the photoconductor. Finally, heat fuses the powder image to the paper, producing a copy of the original image. Carlsons first image, produced on October 22, , was created with negatively charged yellowish moss spores lycopodium on a sulfur-coated zinc plate that had been positively charged by rubbing it with a handkerchief.

Todays copiers and printers have automated and refined all the steps, moving paper at speeds of more than feet a minute, digitally creating and exposing images, and producing images in a rainbow of colors.