The Mechanics of How Photocopiers Work: From Light to Print

Photocopiers may appear complex however they operate on two fairly basic pieces of science.

The heart of the photocopier is its spinning drum that has a special photoconductive coating. A bright light shines on the paper, and white areas are positively charged while black parts remain negatively charged. The drum attracts the toner and binds it onto the paper, creating an impression inked.

Xerography

The technology that powers the majority of copies today is known as the xerography. It’s a dry process made using electrostatic charge. It works by applying static charges to ‘ink which is a black powder called toner. Then using heat to make them adhere to the paper.

Chester Carlson invented the xerographic method in his home laboratory in 1938. It changed the way we work, allowing us to quickly produce huge quantities of copies. While many big corporations turned down Carlson’s invention at the time but he was able turn it into one of the most significant office technological innovations in the 20th century.

In a photocopier the paper that is that is to be copied gets illuminated by a bright light. In a photocopier the sheet of paper to be copied is lit by an extremely intense light. The printed or marked parts don’t bounce the light back. This causes electrons near the edge of the drum to dissipate downwards and leave behind an electrostatic image of the paper.

Next, you need to add a negative charge to the particles of toner. This is accomplished by passing the ‘ink’ through an electric field created by corona wires. The negatively charged toner is attracted to the electrical shadow that is created on the photoconductor belt. It then forms an inked copy of the original document. A roller gives the paper on the other side of a conveyor belt a positive charge which attracts positively-charged toner. The paper and toner are then fused together with intense temperatures, giving the final print a permanent image.

Photocopying Technology

Thue may photocopy hcm ‘print’ documents onto paper by using the power of electricity, rather than ink. The charge is generated by an ejector that rotates and holds a reservoir of black powder, also known as toner. The drum has one type of electric charge, while the toner is charged with another. opposite charges attract each other. The drum has a coating with a chemical that draws toner particles onto a blank piece paper.

The document you wish to copy is placed into a slot at the top of the machine. A bright light scans the document, looking for dark areas. The scanner’s light bounces off of these dark areas, creating an ‘electrical shadow’ of the page that is reflected off of a conveyor belt known as photoconductor.

A photoconductor is the form of a cylindrical object coated with a photoconductive coating. The drum gets an electric charge when it is scanned by a laser in an printer or scanning system in scanner. Drums are also exposed to a reservoir of carbon toner particles that have the opposite charge. The toner sticks to the exposed areas of the drum. These is then heated and fused to the paper passing through the copy machine. Static electricity can cause paper to jam when it’s still on the copied copy. Therefore, it is important to wipe the surface clean of the copy machine regularly.

Photocopier components

The most obvious photocopier components include the glass tray on which you put your document, the lamp that shines illumination on it, and the drum – a rotating conveyor belt coated with a special photo-conductive substance. The photoconductor that was used in earlier copiers was a variant of the rare metal selenium and later machines used improved selenium-telluride alloys. The substance converts light into electricity, by removing electrons from photo-conductive atoms. By shining a bright beam over the original document more light reflects off white, unprinted areas as opposed to the black inked areas, making an electrical shadow of the initial document on the photoconductor.

The optical scanner creates an image which is passed to the printing section of the photocopier by the RIP. The print section is responsible for generating static electricity. it utilizes the same method as an analog photocopier to produce each line of text on the document. The document is then printed by the drum, using heat to make the ink.

You’ve probably witnessed static electricity in the past. If you’ve ever put the balloon against your clothing for a short time and then stuck it on your wall, that was static electricity working. The other trick involves the fact that certain substances become more conductive when they absorb light (photoconductivity). It’s how xerography functions and is the reason modern photocopiers such durable, high-performance workhorses.

Electrophotography

The primary ingredient in the process of photocopying is an electrostatic charge that forms on a drum or another surface. This charge originates from corona wires that are exposed to high voltages in order to create an electrical field between the drum and the paper. The negative charges on the paper pull the positively charged particles of toner which create images on the paper.

Electrophotography, also known as xerography, is the fundamental principle of operation behind every laser and digital copier printers. The process was invented in 1937 by Chester Carlson, who worked with the Battelle Memorial Institute to develop it into a commercial product. He established Haloid Corporation, which eventually was renamed Xerox Corporation in 1961.

Electrophotography uses two fundamental phenomena: materials of opposite electrical charge attract, and that certain materials can conduct better electricity after exposure to light. Carlson created a process of six steps to transfer an image from one surface to the next through these phenomenon.

Then, the document is exposed to a photoreceptor. It is typically an especial drum that is covered with a semiconductor that only conducts in the vertical direction. After placing the document on top of the photoreceptor, a glowing light will be swung on it. The light reflects off the white parts of the document and is then transmitted through mirrors to illuminate dark regions. The reflected light passes through the photoreceptor, and releases its electric charge to the areas of illumination. Latent images are the patterns of electrical charges that show up on the photoreceptor.