The photocopier is a complex machine, but it works using two simple scientific fundamentals.
A spinning drum coated with a special coating is at the center of any photocopier. The bright light shines across the paper, and white areas become positively charged, while black areas remain negatively charged. The drum attracts the toner and binds it to the paper, forming an impression of ink.
Xerography
The technology that drives the majority of copies today is known as the xerography. It’s a non-destructive process made using electrostatic charge. It works by applying static charges to the ‘ink which is the black powder that is known as toner. After that, using heat to cause them to stick to the paper.
Chester Carlson invented the xerographic method in his own home laboratory in 1938. It revolutionized our work by allowing us to quickly produce huge quantities of copies. While many big corporations turned down Carlson’s invention at the time, he managed to turn it into one of the largest office inventions of the 20th century.
In a photocopier the paper that is to be copied is lit by an extremely bright light. The parts of the paper that have been printed or branded by a symbol reflect the light, while the parts that have not been marked reflect it. The electrons near the surface of drums with photoconductive properties are absorbed, leaving a latent image of the paper.
Next, you need to add a negative charge the toner particles. The ‘inks’ pass through an electric field produced through corona cables. The negatively charged toner is drawn by the electrical shadow on the photoconductor belt, and creates an inked replica of the original document. Thue may photocopy hcm is able to give the paper on the opposite side of the conveyor belt a positive charge, which draws toner that is positively charged. The toner and the paper are fused under high heat. The result is that the copy its permanent appearance.
Photocopying technology
Rather than printing out copies using ink, photocopiers utilize electricity to ‘print the document on paper. The charge is created by a rotating drum containing the reservoir that is filled with black powder, also known as toner. The drum and toner are charged with different electrical charges. They attract each other. The drum has a coating with a chemical that draws toner particles onto a blank piece paper.
You place the document you want to copy onto the slot on the top of the machine. The bright light scans the document looking for areas of black. The light from the scanner reflects off these dark areas and produces an “electrical shadow” of the page.
A photoconductor is a cylindrical object with an electroconductive coating. Lasers in printers or a scanning device in a scanner provides the drum with the overall charge of positive electricity. Drums are also exposed to a reservoir with carbon toner particles that have an opposite charge. Toner sticks to the exposed drums which are then heated and combined with the paper. Static electricity can cause paper to jam when it’s still on the copy you have copied. It is therefore important to clean the surface of your copy machine on a regular basis.
Photocopier components
The glass tray, on which you can place your documents, is the most prominent component of the photocopier. Next, there’s the lamp, which emits light onto the document. And finally, there’s the drum, a moving belt covered in a photo-conductive coating. The first copiers utilized a photoconductor made of selenium, however later machines used selenium telluride. The material converts light into electricity by taking electrons from photoconductive atoms. When you illuminate the original document more light will reflect off the areas that are not printed white than inked black regions. This creates an electrical shadow.
The optical scanner generates an image, which is sent onto the printer section of the photocopier via the RIP. The printing section is responsible for generating static electricity. it uses the same process as an analog photocopier to create every line of text in the document. It is then printed by the drum, using heat to make the ink.
You’ve probably witnessed static electricity before. If you’ve ever rub the balloon against your clothing for a couple of seconds then stuck it on the wall, that’s static electricity at work. Another scientific trick is the capability of some materials to become more conductive when they absorb light (photoconductivity). This is the basis of xerography and is the reason modern photocopiers such reliable and high-performance tools.
Electrophotography
The key to the photocopying process is an electrostatic charge that is formed on the drum or another surface. This charge originates from corona wires which are exposed to high voltage 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, creating images on the paper.
Electrophotography, or xerography, is the principle operation that drives all laser and digital copy printers. This process was created in 1937 by Chester Carlson, who worked in conjunction with the Battelle Memorial Institute to develop it into a product for commercial use. He founded Haloid Corporation which became Xerox Corporation in 1961.
Two natural phenomena can be used in electrophotography: materials with opposite charges attract each other and some materials conduct electricity better when exposed sunlight. Carlson created a six-step procedure to transfer images from one surface onto another by making use of these natural phenomenon.
First, the document is exposed to the photoreceptor. It is typically an instrument coated with a semiconductor material which only conducts in a vertical direction. After placing the document in front of a photoreceptor, a bright light will be shone on it. The light bounces off of the white areas of the document and is then transmitted through mirrors to illuminate the dark areas. The reflected light passes through the photoreceptor and discharges its electric charge to the areas that are illuminated. The resulting pattern of electrical charges on the photoreceptor’s surface is known as an image that is latent.