";s:4:"text";s:4651:"The xerographic process, which was invented by Chester Carlson in 1938 and developed and commercialized by the Xerox Corporation, is widely used to produce high-quality text and graphic images on paper. When the charge generation layer molecule is ionized, the electron will move into the ground plane. The captured digital image can be manipulated with image enhancement software to improve the image quality. Internal waxes can be added to lower the toner's adhesion to the fuser roll and allow the toner to fix to the paper. Once the full-color image is on the transfer belt, then another transfer takes place where the full-color image is transferred to the paper. You may think that the process of photocopying a document is really simple – you take a document, put it on the glass screen of a photocopier, a green light passes along the glass and after a few seconds, an identical copy of the document you placed on the screen comes out of the side of the machine. The transfer corona unit behind the medium gives the medium a charge opposite that of the toner and strong enough to overcome the toner's adhesion to the photoreceptor. It is most commonly used in laser printers, photocopiers and fax machines to reproduce and print images, data and office documents for various purposes. In contrast to ink jet printers where the image is written directly to paper, in xerography, the image is first written as a pattern of charge on a photoreceptor. ‘The process, later renamed xerography (dry writing), used electrostatic energy to transfer dry ink to a page.’ More example sentences ‘‘The more you understand about xerography,’ pioneering Xerox engineer Bob Gundlach tells Owen, ‘the more you are amazed that it works.’’
When the laser goes past the edge of the photoreceptor, a new facet rotates in front of the laser and the beam starts sweeping again across the photoreceptor. A video signal from the digital image controls turning the laser on and off, and in this way the photoreceptor is exposed to form a latent electrostatic image. The rapidly moving electrons and ions inside the shield collide with air molecules, ionizing them. Each color separation is transferred to the transfer belt in sequence. Higher end copiers now produce images more than twice that size at over 100 pages per minute in full color with a digital image and multiple sensors and actuators to control the xerographic process. Carlson invented a six-step process to transfer an image from one surface to another using these phenomena, illustrated in figure 1. The photoreceptor is exposed with a bright light (erase lamp) which removes the residual latent image. It was later developed to print colored images as well. Toner particles are small enough so that individual particles cannot be perceived in an image, but large enough so that they can be controlled to move from surface to surface with electric fields.The developed latent image is, at this point, ready to be transferred to a sheet of paper or other medium. When it comes to making trades, they have a $4.95 minimum and a $9.95 maximum, making it the cheapest option you can find. As the photoreceptor passes under the corotron, the uncharged areas acquire a charge which results in a uniformly negatively charged surface as the photoreceptor exits from under the corotron.In figure 6, toner is added as needed from the toner dispenser into the development sump. The laser beam is reflected off the polygon and onto the photoreceptor. Heat fuses the powder image to the paper, producing a copy of the original image (e). Charge control agents are molecules added to the toner which control the sign, level, and the rate of triboelectric charging. This voltage level is required to obtain a strong enough electric field to attract the toner particles used in xerography.Free ions that are normally present in air are attracted to the wire while the free electrons are repelled from the wire. Walk into almost any business office, and you'll probably find a photocopier ("copier") with a line of people waiting to use it. Those who are trading options will find that it is $9.95 plus $1 per contract.
In this way, the surface charge can be controlled by the amount of light exposure.The electrostatic image on the photoreceptor is developed with a development subsystem that contains charged toner particles.