Skip to main content

Explane about Xerox

 In 1937, the process called Xerography was invented by American Law student Chester Carlson. Carlson had invented a copying process based on electrostatic energy. Xerography became commercially available in 1950 by Xerox Corporation. Xerography comes from the Greek for “dry writing”.


Chester Carlson had been frustrated with the slow mimeograph machine and the cost of photography and that lead him to inventing a new way of copying. He invented an electrostatic process that reproduced words on a page in just minutes. Carlson had a hard time finding investors in his new invention. He was turned down by IBM and U. S. Army Signal Corps, it took him eight years to find investor, which was the Haloid Company later to become the Xerox Corporation.


Chester Carlson was both a research engineer and a patent attorney. He filed a patent application in April, 1939, stating, “I knew I had a very big tiger by the tail”. The Xerox Corporation trademarked the name “Xerox” and has protected the name carefully.


Working

A copier works because of one basic physical principle: opposite charges attract.


As a kid, you probably played with Static electricity and balloons. On a dry winter day, you can rub a balloon on your sweater and create enough Static electricity in the balloon to create a noticeable force. For example, a balloon charged with Static electricity will attract small bits of paper or particles of suger very easily. A copier uses a similar process. Inside a copier there is a special drum. The drum acts a lot like balloon — you can charge it with a form of Static electricity. Inside the copier there is also a very fine black powder known as toner. The drum, charged with Static electricity, can attract the toner particles. There are three things about the drum and the toner that let a copier perform it’s magic. The drum can be selectively charged, so that only parts of it attract toner.

Copier

In a copier, you make an “image” in Static electricity on the surface of the drum. Where the original sheet of paper is black, you create Static electricity on the drum. Where it is white. What you want is for the white areas of the original sheet of paper do not attract toner. The way this selectivity is accomplished in a copier is with light — this is why it’s called photocopier! Somehow the toner has ato get onto the drum and then onto a sheet of paper. The drum selectively attracts toner. Then the sheet of paper gets charged with Static electricity and it pulls the toner off the drum. The toner is heat sensitive, so the loose toner particles are attracted (fused) to the paper with heat as soon as they come off the drum. The drum, or belt, is made out of photoconductive material.


Here are the actual steps involved in making a photocopy: The surface of the drum is charged. An intense beam of light moves across the paper that you have placed on the copier’s glass surface. Light is reflected from white areas of the paper and strikes the drum below. Wherever a photon of light hits, electron is emitted from the photoconductive atoms in the drum and neutralizes the positive charges above. Dark areas on the original do not reflect light onto the drum, leaving regions of positive charges on the drums surface.

Comments

Popular posts from this blog

Planets & Solar-system

Our solar system consists of the sun, eight planets, moon’s, dwarf planets, an asteroid belt, comets, meteors and others. The sun is the centre of our solar system whereas the planets, their moon’s, the asteroids comets and other rocks and gas all orbits the sun. The eight planets that orbit the Sun are Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus and Neptune. Recent studies state Pluto is not a ‘planet’ but a dwarf planet. Easy way to remember the order of the planets (and Pluto) are the mnemonics: “My Very Enchanting Mother Just Showed Us Nine Pizzas” (MVEMJSUNP). The Sun The Sun is the most prominent feature in our solar system. It is the largest object and contains approximately 98% of the total solar system mass. 109 Earths would be required to fit across the Sun’s disk, and it’s interior could hold over 1.3 million Earths. 1. Mercury:- Mercury was named by the Romans after the fleet-footed messenger of the gods because it seemed to move more quickly than any other pla

Explore about Flowers and their facts

Nature has its ornaments to make it beautiful and worth watching, and these ornaments are embedded with gems called flowers. The history of flowers on the planet starts long before humans lived. Flowers announce spring and attract honeybees and also been used in medicine and eaten for food. They have become part of culture rituals, held by brides during weddings and found in gravesites. Perfect & imperfect Flowering plants abruptly appeared during the Cretaceous period, over 100 million years ago when dinosaurs roamed. Just as people love the scent and colour of flowers, animals and insects do too. Flowers having both male and female reproductive parts are called “perfect”. Flowers having one or the other are called “imperfect” or “unisexual”. Plants & flowers A plant might have some flowers with male reproductive parts called stamens and other flowers with female parts, which are called carpels. Plant having both male and female flowers is “monoecious”. A plant having only one

Explain about Gymnastics

  A successful gymnast must be strong, flexible, brave and graceful. However, most people can do some form of gymnastics. We learn as a child to do cartwheel or handstand in school, the basis of all gymnastic moves. Gymnastic dates back to ancient Greece and are a form of acrobatic exercise. Now a days it has evolved into a popular spectators spot. Rhythmic and artistic are the two main types of gymnastics. Artistic gymnastics is performed on objects such as a wooden horse or a vault. During gymnastics players compete in eight different events. There are floor exercises and vaults. Men compete on bars, horse and rings. Women have to perform on beams and asymmetric bars. Judges award points out of ten and many of the champions of yesteryears have been teenagers. History of Gymnastics Gymnastics has been around for over 2000 years but as a competitive sport it is more than 100 years old. In 1830s, the sport of gymnastics was introduced to United States and its school systems by immigrant