Photocopier

A copier makes new copies of papers.

It uses a special powder. This powder is called toner. A bright light shines on your paper. The light hits a drum. The powder sticks to the drum. Then, the powder moves to the paper.

Heat and pressure press the powder down. This makes the image stay on the paper. It is very fast and cheap.

Copiers help us at school and work.

A photocopier is a machine that makes copies of papers.

Most machines use a way called xerography. This name means "dry writing." It is a set of steps that uses static electricity.

First, a drum gets a charge. This drum has a special coating. This coating is a photoconductor. A photoconductor is a material that carries electricity when light hits it. Next, a bright lamp shines on your paper. The light bounces off the white parts of the paper. This light hits the drum. The light makes some parts of the drum lose their charge. The dark parts of the image keep their charge.

Then, the machine uses toner. Toner is a fine powder. The toner is positively charged. It sticks to the dark parts of the drum. This is like how paper sticks to a balloon. Next, the toner moves from the drum to a piece of paper. Finally, the machine uses heat and pressure. This melts the powder so it stays on the paper.

Modern machines can also scan and print digitally. They can even make copies on both sides of a page.

A photocopier is a machine that makes copies of documents. It can also copy other visual images onto paper or plastic film. Most modern machines use a technology called xerography. This is a dry process that uses electric charges to work.

It is a very fast and cheap way to duplicate information. These machines are used all over the world in offices, schools, and government buildings.

To understand how xerography works, you can look at its steps. First, a cylindrical drum is given an electric charge. This drum has a special coating called a photoconductor. A photoconductor is a material that can carry electricity when light hits it.

Next, a bright lamp shines on the original paper. The light reflects off the white areas and hits the drum. This light makes those parts of the drum lose their charge. The dark parts of the image keep their charge. Then, a powder called toner is applied to the drum. The toner is positively charged, so it sticks to the negatively charged dark areas. This is like how a balloon can pick up small bits of paper. Finally, the toner is moved to a piece of paper. Heat and pressure rollers melt the toner so it stays on the page.

Chester Carlson was the inventor of photocopying. He worked as a patent attorney in New York. He had to make many copies of important papers for his job. This was a very slow and painful task for him. He began experimenting with photoconductivity in his own kitchen. In 1938, he applied for a patent for his process. He used a zinc plate and sulfur to make his first copy. The copy showed the words "10-22-38 Astoria" in a mirror image.

Carlson faced many hard jobs while trying to share his invention. Between 1939 and 1944, over 20 companies turned him down. These included big companies like IBM and General Electric. In 1944, the Battelle Memorial Institute began helping him improve his process. Later, the Haloid Corporation wanted to sell these machines. They thought the name "electrophotography" was too hard to remember. They chose the name xerography, which means "dry writing." In 1949, the Xerox Corporation introduced the first xerographic copier called the Model A.

Today, many machines are more advanced than the old ones. Some are called multi-function printers. These devices can copy, fax, scan, and print all at once. Many modern copiers use digital technology instead of analog parts. A digital copier works like an integrated scanner and laser printer. This allows the machine to improve the quality of an image automatically. It can also scan a page once and print it many times.

Some machines even have an ADF, which is a tool that feeds many pages into the scanner automatically. This makes copying large amounts of work much easier.

A photocopier is a machine designed to make copies of documents or visual images. It can produce these copies onto paper or plastic film very quickly and cheaply. While many different technologies exist, most modern office machines use a process called xerography. This is a dry method that relies on electrostatic charges to function.

Because they are efficient, photocopiers are essential tools in business, education, and government sectors. Even as digital document storage grows, these machines remain widely used around the world.

To understand xerography, we must look at the specific steps of the mechanism. First, a cylindrical drum is given an electrostatic charge by a high-voltage wire. This wire is called a corona wire, or sometimes a charge roller is used. The drum is coated with a photoconductor, which is a semiconductor material. A photoconductor becomes conductive, or able to carry electricity, only when it is exposed to light.

This property is the foundation for how the image is formed.

Next, the machine performs the exposure step. A bright lamp illuminates the original document being copied. The white areas of the document reflect this light onto the surface of the photoconductive drum. When light hits the drum, those specific areas become conductive and discharge to the ground. However, the dark areas of the original document do not reflect much light. These dark areas remain negatively charged on the drum surface.

Once the charge pattern is set, the machine enters the developing stage. The machine applies toner, which is a fine powder, to the drum. This toner is positively charged. Because opposite charges attract, the positive toner sticks to the negatively charged areas of the drum. This is similar to how a balloon with a static charge can pick up small bits of paper.

This creates a visible image made of powder on the drum.

After the image is developed, the transfer and fusing steps occur. The toner image is moved from the drum onto a piece of paper. This works because the paper carries an even greater negative charge than the drum. Finally, the toner must be permanently attached to the page. The machine uses rollers that apply both heat and pressure to melt the toner. This process, called fusing, bonds the powder to the paper fibers so the image does not rub off.

The history of this invention began with Chester Carlson. Carlson was a patent attorney in New York who found copying papers to be a tedious and painful task. He began experimenting with photoconductivity in his own kitchen. In 1938, he applied for a patent for his "electrophotography" process. His first successful test used a zinc plate covered in sulfur. He used a microscope slide to create a mirror image of the words "10-22-38 Astoria."

Despite his success, Carlson struggled to find support for his idea. Between 1939 and 1944, over 20 companies rejected him. Large corporations like IBM and General Electric did not believe there was a market for copiers. Eventually, the Battelle Memorial Institute helped him refine the process. In 1947, the Haloid Corporation licensed the technology. They felt "electrophotography" was too difficult to remember, so they chose the term xerography. This name comes from Greek roots meaning "dry writing."

In 1949, the company introduced the Model A, the first xerographic copier. Haloid later became the Xerox Corporation in 1961. The company became so successful that people began using the word "xeroxing" as a verb. This made the brand a generic trademark in North America, though the company has fought to protect its name. Xerography was much more affordable than older methods. For example, in 1969, a Verifax print cost $0.15, while a Xerox print cost only $0.03.

Modern machines have evolved into highly complex devices. Many are now multi-function printers that combine copying, faxing, scanning, and printing. Digital technology has replaced older analog systems in many models. Digital copiers act as integrated scanners and laser printers. They offer features like automatic digital collation, which saves time. A digital copier can scan a page once and then print it many times automatically.

Some machines also include an ADF, or Duplex Automatic Document Feeder, to handle many pages at once.