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The sweet science of a Ricoh photocopier

Photocopying documents seems like a simple and effortless errand to run. We walk into the office, put our documents upside down on the glass, push some buttons, and our identical copy pops out of the other side of the machine. But not many of us are aware of the inner workings and complexity of the machine that has transformed our way of work. Here’s our quick and easy guide to the way a photocopier works for the readers.

Its working principle

At its heart, a photocopier works on two basic principles: Opposite charges attract each other, and the phenomenon that the material becomes more electrically conductive after absorption of some electromagnetic radiation i-e photoconductivity.

Inside of a Photocopier:

If you take a sneak peek at the inside of a photocopier, only then you’ll realise the complexity of it. Some key
components that make-up a photocopier include:

Paper Tray

The paper tray is a container where the stack of paper sheets is held. A blank page is taken from the stack in order to transfer the print to it.

Glass

The glass is where you keep the original document to be copied, upside down.

Exposure lamp

A light source is required inside the photocopier with adequate energy to discharge the electrons of the photoconductive materials. While this can be achieved using UV light, it can be harmful to the skin and eyes. Therefore, an ordinary fluorescent bulb is used to put the light on the original document. 

When you push the green button, the lamp begins moving inside the photocopier and illuminates the original one strip at a time.

Mirrors and Lenses ​

The mirror guides the reflected light from the original to the rotating drum underneath via lenses. The position of these lenses can be varied in order to reduce or enhance the size of the image on your copy.

Photoreceptor drum or belt

The photoreceptor drum is, without a doubt, the heart of this intricate machine. It is basically an aluminum cylinder coated in a layer of some semiconductor material like silicon or germanium. This semiconductor material is photoconductive in nature. 

The drum rotates in synchronisation with the flash of light across the original to create the image in bits and pieces. When one strip of light is focused on the drum underneath, it rotates to expose another untouched area. This previous strip of light, in the meantime, gets in contact with the charged toner particles and the paper. It takes multiple rotations of the drum before the entire original can be duplicated.

Corona wires

The corona wires are essential to transmit the positive charges to the drum as well as the paper. There are two corona wires. One is parallel to the drum and transfers the positive charges to the photoconductive material. And the other is positioned in such a way that it transfers the positive charges to the paper as it makes its way towards the drum.

Toner

Inside a photocopier, the toner particles are glued to large, positively charged beads and kept inside a toner cartridge. These toner particles are plastic-based, negatively charged, and black in color. Once the toner particles get in contact with the positively charged drum, they immediately become attracted to it, leaving behind the beads. And subsequently, become more attracted to the positively charged paper. These particles then stay on the paper for a while until fusion takes place.

Fuser

The fuser adds some final touches to the paper to prepare your identical copy. It comprises rollers with a coating of Teflon and quartz tube lamps. 

When the paper gets through it, the rollers press and ingrain the toner particles on the paper and the tube lamps generate enough heat to fuse them on it. The Teflon coating keeps the melted particles from sticking to the fuser instead.

If you require a copier printer scanner for your office, give us a call on 0208 8083103. We’ll be happy to discuss your Ricoh photocopier requirement and guide you through some cost effective solutions.

The process from start to finish

The process of photocopying begins with one of the corona wires charging the photoreceptive drum with a layer of positively charged ions. When you hit the green button, the exposure lamp inside begins moving and flashes the light on the original. The blank areas of the document reflect the light, whereas the dark areas (texts and pictures) absorb the light, thus creating an electrical copy. This copy is then guided through the mirror and lenses onto the drum. 

The places on the drum illuminated by the light kick the electrons out of their atoms (photoconductivity). These electrons then become immediately attracted to the external coating of positively charged ions, thus creating neutral particles, and the charged particles remain only in the dark places. In the meantime, a voltage is also supplied to the core of the aluminum drum so current can pass through and replace the electrons released by the atoms. 

Now the drum rotates, and its exposed area gets in contact with the rollers adorned with toner beads. The negatively charged toner particles leave the beads and become attached to the areas of the drum that remain positive and later to the positively charged paper. In this way, the electrical copy gets transferred to the paper from the drum via toner. As soon as the complete original gets reproduced on the paper, it passes through the fuser. Where the heated rollers press the toner particles and fuse them to the paper permanently. The copy then proceeds towards the collection tray, and the photocopier prepares for the next batch by coating the drum with a fresh layer of positively charged ions.