The photocopier is a complicated machine, but it works using two basic scientific principles.

A drum that is coated with a special coat is at the center of any photocopier. A bright light shines over the paper and white areas become positively charged while black parts remain negatively charged. The drum is then attracted by toner, which sticks to it and makes an inked print on the paper.

Xerography

The technology behind most copy machines today is called xerography. It’s a process that is dry made using electrostatic charge. In essence, it operates by transferring opposite electrical static charges to the “ink” (a black powder referred to as toner) followed by applying the heat to cause them to stick to the paper.

The xerographic process was invented in 1938 by Chester Carlson in his home laboratory, and it has revolutionized the way we work by allowing us to make an enormous amount of copies in a short time. Carlson’s idea was initially disapproved by a few large corporations, but he went on to make it one of the most important office innovations of the 20th century.

In a photocopier, the sheet of paper to be copied is lit by a bright light. The paper parts that have been printed or branded with a symbol reflect the light, while those that aren’t marked do. The electrons near the surface of drums with photoconductive properties disappear, leaving behind an unreflecting image of the document.

Next, the toner is charged negatively. This is accomplished by sending the ‘ink’ into an electric field generated by corona wires. The negative toner is dragged towards the electric reflection of the photoconductor. This creates an inked copy of the original. The paper from the other side of the conveyor belt then gets a positive charge from the roller, which draws the positively charged toner. The toner and the paper are then fused with high heat. The result is that the print its permanent appearance.

Photocopying technology

Rather than printing out copies with ink, photocopiers utilize electricity to ‘print the paper. This charge is generated by a drum that rotates and contains the reservoir that is filled with black powder, also known as toner. The drum is charged with one type of electrical charge and the toner holds another one – opposing charges draw each other. The drum is coated by a special chemical that is able to pick up the toner particles, and deposit the toner particles on a clean sheet of paper.

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

A photoconductor consists of a cylindrical object with a photoconductive coating. A laser in a printer or scanning system within a scanner provides the drum with an overall positive electric charge. It also exposes it a reservoir of carbon particles that have a negative charge. Toner sticks to exposed drums that are heated before being fused with the paper. The copied paper still contains a small amount of static electricity that can result in the paper sticking in places it shouldn’t and lead to jams. That’s why it is important to wipe down the surface of your copier regularly.

Photocopier components

The most obvious photocopier components are the glass tray where you put your document as well as the lamp that shines the light onto it, and the drum – a rotating conveyor belt coated with a special photo-conductive substance. The first copiers utilized a photoconductor made of selenium, however later machines used selenium telluride. The material converts light into electricity via the removal of electrons from photoconductive atoms. If you shine a bright light on the original document more light will bounce off of the areas of the white paper that have not been printed than printed black areas. This causes an electrical shadow.

This is then scan by the optical scanner, which produces an electronic image which the RIP passes on to the printer section of the photocopier. The printing section is also responsible for producing static electricity. it uses the same process as an analog photocopier to generate each line of text on the document. It is printed on the drum, using heat to make the ink.

Static electricity is among the two tricks in science that can make a photocopier function well, and something you’ve probably encountered previously. Static electricity is what happens when you rub a balloon on your clothing and then attach it on the wall. Another scientific trick is the capacity of certain materials to become more conductive after absorbing light (photoconductivity). This is how xerography functions, and it’s what makes the majority of modern photocopiers reliable and efficient machines they are.

Electrophotography

The main ingredient of the process of photocopying is the electrostatic charge that forms on a drum or other surface. The charge is generated by corona wires which are exposed to high voltage in order to create an electrical field that is created between the drum and paper. The negative charges on the paper attract the positively charged toner particles, creating an image on the paper.

Thue may photocopy hcm also referred to as xerography is the basic principle of operation of all digital copier and laser printers. The technique was developed in 1937 by Chester Carlson, who worked in conjunction with the Battelle Memorial Institute to develop the technology into a commercial item. He established Haloid Corporation which became Xerox Corporation in 1961.

Electrophotography utilizes two natural phenomena, which is that materials of opposite electrical charge attract, and that certain materials are better conductors of electricity when exposed to light. Carlson created a six-step procedure for transferring images from one place onto another by using these natural phenomena.

The document is then exposed to a photoreceptor. It is typically an instrument that is coated with a semiconductor which only conducts in the vertical direction. Then, the document will be placed over the photoreceptor, and a shining light is reflected on it. The light is reflected off of the white areas of the document and then transmitted through mirrors in order to light the dark areas. The light reflected from the mirrors is transmitted through the photoreceptor, that discharges the electric charge into the areas that are illuminated. The resultant pattern of electric charges on the photoreceptor is known as an image that is latent.