When an image or text is being printed on paper, the printer gathers toner from the hopper with the developer. The developer, composed of negatively-charged magnetic beads attached to a metal roller, moves through the hopper gathering toner. The developer collects positively-charged toner particles and brushes them past the drum assembly. The electrostatic image on the drum has a stronger negative charge than the beads on the developer, so the toner is pulled from the developer onto the drum.
Next, the drum moves over the paper. The paper has an even stronger negative charge than the drum, and pulls the toner particles off of the drum in the shape of the electrostatic image. At this point, gravity is the only thing keeping the toner in place. In order to affix the toner, the paper needs to pass through the fuser rollers, which are heated by internal quartz tube lamps. The heat melts the plastic in the toner particles, causing the toner to be absorbed into the paper fibers.
This is possible because the rollers are coated with Teflon, the same material that helps food slide out of non-stick frying pans. Color toner works essentially the same way as monochrome toner, except the process is repeated for each of the toner colors. The standard toner colors are cyan blue , magenta red , yellow and black.
The black is needed because the three primary colors red, yellow and blue can be combined to form any color except black. These four toner colors, when combined at varying levels of saturation and lightness, can produce millions of different shades and hues. This quick guided tour of toner cartridges should help provide a basic understanding of how they work. The current technology of toner cartridges has allowed laser printers to dominate the office printing market.
Quick answer: Laser printers use an electrical charge to attract toner particles to a transfer roller. Toner particles are pressed onto a piece of paper, while heat and pressure from the fuser unit permanently fix the image onto the page. This video below outlines how laser printers work. As you'll see, it is a complex dance of data, static electricity, and light.
To begin the laser printer process, the document is broken down into digital data and sent from the respective computer to the printer. In a feat of binary wizardry, printers reassemble this computer data into a printed image. Laser printers will capture the data and process the digital document. Laser printers leave a residue on the printer drum.
Cleaning is a physical and electrical process carried out in order to remove the previous print job and prepare the photosensitive drum for the new print job.
During the cleaning process, remnants of toner on the drum are scraped away by a rubber-cleaning blade into a debris cavity. Electrical charges remaining on the drum from the prior print job are defused by electrostatic erase lamps inside laser printers. Lubrication is then applied to the heat roller in order to make sure an adequate amount of heat is evenly applied to transfer the incoming image.
The process called conditioning involves applying a charge to the drum unit and the paper as it passes through the corona wire. Adding a static charge to the paper allows an image to be electrostatically transferred to the laser printer page. The same force that makes your socks stick to your sweaters when they come out of the dryer also works inside laser printers! The primary charge roller springs to life, spinning the adjacent organic photoconductor OPC drum.
Ions on the corona wire coat the drum with static electricity. The electro-photographic process begins at the molecular level. The drum completes its revolution, slathered with a negative charge. Laser time! The next step is exposing. Here, the photosensitive drum is exposed to a laser beam. Every area of the drum exposed to the laser has its surface charge reduced to about volts DC. An invisible latent print is generated as the printer's drum turns. The image that will ultimately be printed exists for the first time as a thin layer of electrons on the OPC drum.
The darkness within the printer cartridge is broken by the glow of the laser. The beam bounces off a spinning, multi-sided mirror and breaks into countless rays of information, spraying the OPC drum with its knowledge, turning the negative charges positive.
Line-by-line, the laser speaks to the revolving surface of the drum unit, describing a page with the language of charged toner particles. This part is black, this part is yellow, and this part The drum wears a positively charged image on its surface, ready to transfer onto the paper. In the developing stage, toner is applied to the latent image on the drum. Toner is composed of negatively charged powdered plastics — black, cyan, magenta, and yellow. The drum is held at a microscopic distance from the toner by a control blade.
The anatomy of a printer includes:. Requiring a high voltage in order to charge the drum, the power supply works to convert AC current into higher voltages needed for the transfer process. The role of the drum unit is to attract positively charged toner particles onto its surface.
In order to achieve this, laser printers usually use a corona wire which carries a high voltage. Once the drum is adequately charged, the laser beam is guided onto the surface of the drum via mirrors which precisely scans the images onto the surface of the drum. Laser printers use microscopic ink particles in a powdered form known as toner. Once heated by the fuser unit, the toner melts allowing it to be fused to the paper fibres under pressure.
Like inkjet cartridges, toner is most commonly used in the CMYK colours. Combined, these colours can recreate any colour palette. The primary corona wire is responsible for positively charging the drum unit in order for the drum unit to be able to draw the toner particles onto its surface.
The transfer corona wire is given a negative charge in order to negatively charge the paper and draw the toner particles from the surface of the drum onto the sheet. Both of these wires require high voltages in order to create adequate charge, this is supplied by the high voltage power supply. The fuser unit comprises of two heated rollers used to physically fuse the toner particles onto the paper. Using high levels of heat and pressure, the powdered toner particles are melted and form a strong bond with the fabric of the paper.
Given the high speed that the fuser unit operates, the sheet has as little contact with the paper as possible which avoids the risk of fire. The waste toner bottle is used to collect excess toner from the photosensitive drum that is unused during the printing process. Excess toner is deposited in a reservoir and once full, the waste toner bottle must be replaced. The most obvious advantage of laser vs inkjet is speed. With higher first page and pages per minute speeds, laser printers offer a clear edge over their inkjet counterparts.
These faster speeds make laser printers the perfect choice for the office environment.
0コメント