A Copier Guide: What's That? Parts of a Copier Explained

The main parts of a copier are the document feeder, platen glass, control panel, drum, toner, developer, fuser, paper trays and output tray or finisher. Each part handles one stage of turning an original into a finished copy.

Once you know what each part is called, it becomes much easier to read error messages, order the right supplies and explain a problem to a technician. Use this table as a map of the machine.

For a wider list of terms, see our guide to useful copy machine jargon.

The parts on top of a copier are the document feeder, the platen glass and the control panel. Together they capture your original and tell the machine what to do with it.

Document feeder

An automatic document feeder (ADF) is the tray on top that pulls a stack of originals through the scanner one page at a time, so you do not have to lift the lid for every sheet. Feeders that handle two-sided originals come in two main types:

• Reversing feeder: scans one side, flips the page and scans the other side.
• Single-pass duplex feeder: scans both sides at once with two scanning units, which is usually faster for two-sided work.

You will often see the abbreviation DADF, which stands for duplexing automatic document feeder, a feeder that can scan both sides of each original.

Platen glass and control panel

The platen glass is the flat glass surface under the lid, used for books, fragile originals and single pages. Next to it, a narrow glass strip reads pages passing through the feeder. Keeping both clean prevents lines on copies; our guide on how to keep a copier clean shows how. The control panel, usually a touchscreen on business machines, is where you choose functions, settings and destinations. To learn what happens when you press scan, read our guide to the scanning process.

Inside a copier, the scanned image is written onto a charged drum, toner sticks to that image, the toner is transferred to paper, and heat and pressure bond it in place. This process is called xerography.

Xerography is the dry printing process used by most copiers and laser printers, which uses static electricity, light and toner powder to reproduce an image; see Wikipedia's xerography article for the history. In simplified form, the steps are:

1. Scan: the scanner captures the original as a digital image.
2. Charge: the surface of the drum receives an even electrical charge.
3. Expose: a laser or LED array writes the image onto the drum, changing the charge where the image will be.
4. Develop: toner is attracted to the charged image on the drum.
5. Transfer: the toner image moves from the drum to the paper, directly or through a transfer belt on many color machines.
6. Fuse: the fuser melts and presses the toner into the paper.
7. Clean: leftover toner is wiped from the drum, ready for the next page.

The whole cycle repeats for every page in a fraction of a second. For a broader look at how copiers developed from early photographic machines to today's digital multifunction devices, see Wikipedia's photocopier article.

The drum holds the image, toner forms it, the developer delivers the toner, and the fuser makes it permanent. These four parts are the heart of the machine and the ones you will hear about most when ordering supplies.

Drum

A drum is a light-sensitive cylinder that holds the page image as a pattern of electrical charge so toner can stick to it. Drums wear with use, and on many machines they are replaced separately from toner. Worn drums can cause repeating marks or faint, uneven copies.

Toner

Toner is a fine, dry powder that forms the printed image and melts into the paper during fusing; Wikipedia's toner article explains how it is made. Black-and-white copiers use one toner, while color machines use cyan, magenta, yellow and black. Replacement cartridges and drums are in our toner and drum collection.

Developer

Developer is a material, on many copiers a mixture of tiny carrier beads, that carries toner to the drum. Some machines use a separate developer unit, while others combine it with the toner or drum.

Fuser

A fuser is a pair of rollers, one heated and one applying pressure, that melts toner into the paper so it does not smudge. This is why pages come out warm. Fusers wear over time and are available in our fuser collection.

The paper drawers, bypass tray, duplex unit and output tray handle the paper. They feed blank sheets in, move them through the machine and deliver the finished copies.

• Paper drawers: the main trays at the front, usually adjustable for letter, legal and on larger machines tabloid paper.
• Bypass tray: a fold-out tray on the side for envelopes, labels, card stock or one-off sizes. It is also called the manual feed or multipurpose tray.
• Large capacity tray: an optional high-capacity drawer or side unit for offices that print long runs.
• Duplex unit: the internal path that flips paper so the machine can print on both sides automatically.
• Feed rollers: rubber rollers that pick up each sheet; worn rollers are a common cause of misfeeds.
• Output tray: where finished pages land if no finisher is fitted.

Most paper jams start with the paper itself, such as damp or curled sheets. Our guide to common copier frustrations and their solutions covers jams and other everyday problems.

A copier finisher is an optional unit attached to the side of the machine that sorts, staples, hole-punches, folds or makes booklets from finished pages automatically. It turns a stack of loose copies into ready-to-use documents.

Common finishing options include offset stacking, corner or edge stapling, two- or three-hole punching, folding and saddle-stitched booklet making. Not every finisher does all of these, and some features are separate add-on kits. Finishers can usually be added when you buy the copier, and on many models later as an upgrade, but they must be compatible with that specific machine. Our guide to popular finishing options explains which suit different offices. For jobs beyond what a copier finisher can do, such as binding or laminating, see our print finishing machines.

On most copiers you can replace toner cartridges, waste toner containers and, on many models, drums yourself. Fusers, feed rollers and internal assemblies are often better left to a qualified technician.

The split varies by manufacturer and model. Some machines are designed so office staff can swap almost every consumable, while others expect a service technician to handle drums and developer as part of routine maintenance. Whatever your machine, use the correct part for your exact model, because similar-looking cartridges are often not interchangeable.

Here is a practical checklist for using what you now know about copier parts when something goes wrong:

1. Read the message. Note which part the display names, such as toner, drum, fuser or waste toner.
2. Check the manual. Confirm whether that part is listed as user-replaceable for your model.
3. Find the part number. Look on the old part, the supplies screen or the manual to order the right item.
4. Turn off and cool down. Let the fuser area cool before opening covers near it.
5. Replace carefully. Follow the steps on the label or in the manual, and remove all packing tape.
6. Run a test copy. Make a copy and a print to confirm the problem is solved.
7. Call for help if needed. If the same error returns, contact a qualified technician.

Whether you need replacement supplies or a new machine, the CopyFaxes team can help you compare options. Browse office copiers, try the machine finder, or contact our team with your copier model and we will help you find the right part or a suitable replacement.