The photocopier is a complex machine, yet it operates on the basis of two fundamental scientific principles.
The basis of the photocopier is a rotating drum that has a special photoconductive coating. The bright light shines over the paper and white areas become positively charged, while black areas remain negatively charged. The drum attracts toner, which sticks to it and makes an inked print on the paper.
Xerography
The technology that drives the majority of copy machines today is called xerography. It’s a process that is dry using electrostatic charges. It works by transferring opposing static charges to the ‘ink’, which is a black powder known as toner. It then uses the heat, they stick to 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 some big companies turned down Carlson’s invention at the time but he was able turn it into one of the biggest office innovations in the 20th century.
The paper sheet that will be photocopied is illuminated by a bright light. In a photocopier the sheet of paper that is to be copied is lit with an extremely bright light. The printed or marked parts don’t bounce the light back. The electrons near the surface of drums with photoconductive properties dissipate down, leaving an unreflecting image of the document.
Then, the toner gets charged negatively. The ‘inks’ are passed through an electric field generated through corona cables. The toner with a negative charge is drawn by the electrical shadow that is created on the photoconductor belt, and creates an inked copy of the original document. The roller provides the paper on the other side of a conveyor belt a positive charge, which draws positively charged toner. The toner and paper are melted under high temperatures. This gives the print its permanent appearance.
Photocopying technology
Instead of printing copies with ink, photocopiers make use of electricity to ‘print the paper. The charge is generated by the rotating drum which is a reservoir for black powder called toner. Toner and the drum both have different electric charges. They attract one another. The drum is coated of a chemical that attracts toner particles onto a blank piece paper.
You place the document you’d like to copy into the slot on the top of the machine. The bright light scans the document, looking for black areas. The scanner’s light bounces off of these dark regions creating an electrical shadow’ of the document on a conveyor belt-like element known as photoconductor.
Thue may photocopy hcm is the form of a cylindrical object coated with an electroconductive coating. The drum gets positive charge through a laser in an scanning device or scanner. The drum is also exposed to a reservoir of carbon toner particles with the opposite charge. Toner sticks to exposed drum surfaces which are then heated and fused with the paper. The copy paper retains a bit of static electricity, which can sometimes result in the paper sticking in places it shouldn’t and cause jams. This is the reason it’s crucial to clean the paper surface of your copier regularly.
Photocopier components
The glass tray, on which you place your document, is the most obvious part of a photocopier. There’s also the lamp, which illuminates the document. Finally, there’s the drum, which is a rotating belt covered in a photo-conductive coating. The photoconductor 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 photoconductive atoms. When you shine a bright light onto the original document, more light will reflect off the areas of the white paper that have not been printed than inked black areas. This creates an electrical shadow.
Then, it is scanned using the optical scanner which creates an electronic image that the RIP sends to the photocopier’s printing section. The printing section is responsible for producing static electricity. it uses the same process as a photocopier analog to generate each line of text on the document. The document is printed on the drum using heat to set the ink.
Static electricity is one the two techniques used by scientists to allow a photocopier to work, and it’s something you’ve probably seen before. Static electricity is what you experience when you rub a balloon on your clothing and then attach it on the wall. The other trick involves the fact that some materials get more conductive as they absorb light (photoconductivity). This is the basis of xerography and is what makes modern photocopiers so reliable and high-performance tools.
Electrophotography
A charge electrostatic that forms on the drum or other surface is essential to photocopying. The charge is formed through corona cable that is exposed to high voltage in order to generate an electric field between drum and the paper. The toner particles are positively charged and draw the negative charges of the paper. This creates an image.
Electrophotography, also known as xerography, is the principle operation that drives all laser and digital copy printers. The technique was developed in 1937 by Chester Carlson, who worked alongside the Battelle Memorial Institute to develop it into a product for commercial use. He established Haloid Corporation, which eventually was renamed Xerox Corporation in 1961.
Two natural phenomena can be employed in electrophotography. Materials with opposite charges interact with one another, and certain materials conduct electricity better when exposed sunlight. Carlson created a six-step procedure for transferring images from one place to another by making use of these natural phenomena.
The first step is to expose the document so that it can be copied to a photoreceptor typically, which is a drum that is covered in a semiconductor material that only conducts vertically. When the document is placed on top of the photoreceptor, a shining light is reflected onto it. The light bounces off the white parts of the document and is then transmitted through mirrors to illuminate dark regions. The light reflected passes through the photoreceptor and discharges its electric charge to the illuminated areas. Latent images are patterns of electric charges that appear on the photoreceptor.