WHAT IS PHOTOCOPY?(XEROGRAPHY)
The coping process is called Xerography.It is derieved from a Greek word Xeros and Graphos meaning
“DRY-WRITING”.It is one of the applications of electrostatics.It is an electronic machine that can makes thousands of copies of images and documents.
Unlike charges attract each other.
- The main part of photocopier is the drum made up of aluminum coated with a layer of selenium.
- A Lamp which provides enough light energy to eject electrons from photo-conductive atoms.
- A lens to focus the Image on the drum.It can also reduce or Magnify the size of the image.
- A Special kind of dry Ink called Toner.
- Heated pressure roller with some heating arrangement.
Aluminium is an excellent conductor but selenium is an insulator in the dark and becomes conductor when light falls on it.In other words it is a photoconductor.The Selenium is made positively charged by corona wires.It will remain positively charged as long as it remains in the dark.When light is Incident on a document ,It is reflected passes through the lens and falls on the selenium.,The corresponding bright and dark areas are formed on the drum.
The dark areas retain their positive charge ,but the light areas retain their positive charge,but the light areas retain their positive charge and hence become conducting .So the electrons from aluminum pass through the selenium and neutralize the positive charges.Thus a positive charge Image is left on the selenium surface.Then,a special kind of negatively charged dry-ink called “Toner” is sprayed over the drum where it sticks to the positively charged areas.The Toner from a drum is transferred on the highly positively charged sheet of paper.Heated pressure roller then melts the toner into the paper to produce the permanent impression of the document.
BEST PHOTOCOPIERS OF 2017:
- 1. Canon VarioPrint 110
- Sharp MX-1054
- Xerox WorkCentre 7535.
- Kyocera TASKalfa 4551ci
- Ricoh MP C4503
- Xerox Phaser 3300MFP
- Konica Minolta bizhub C454
- Toshiba e-STUDIO3555C
- Canon imageRUNNER ADVANCE C5235
- HP Officejet Enterprise X585z
- Canon IR Advance 8205 PRO
It is used widely in the business, education, and government sectors.Colored Toner became available in the 1950.There is increase in the trend for new photocopiers to use digital technology, thus replacing the older technology. With digital copying, the copier effectively consists of an integrated scanner and laser printer. This design has several advantages, such as automatic image quality enhancement and the ability to do much more things.The advancement of technology increases the technology used in photocopier machines.Another process of photocopying is that became available in 1950.It uses the infrared light hest. In this process sensitized copy paper is placed in contact with the original and both are exposed to infrared rays. The original absorbs the rays in areas darkened by print or by the lines and shades of an illustration, and thereby transfers the impressions to the surface of the copy paper.Thanks for Reading.