Introduction
The market today with a wide variety of printing technologies, everything that is possible to pass to the most diverse types paper and fabric work carried out on computers or specialized machines. With regard to the segment of personal computers, the printers, the most common are those who use the technologies – laser, inkjet and dot-matrix. In this article, you will learn about some of the details the operation of these standards and will have guidelines on what kind to buy.
At the end of the text, you will also see a summary on the other printing technologies available today.
Some of the terms
Before reading about the printers themselves, it is important to know the meaning of some terms commonly found in the description of the printers. These information are useful at the time of purchase a-type equipment:
– dpi: abbreviation for dots per inch (dots per inch), a measure that indicates the “resolution” with which the device you can work with. If a printer is capable of working with 4800 x 1200 dpi, for example, means that the equipment can generate 4800 dots horizontally and 1200 points in the vertical in the one inch (one inch equals 2.54 centimeters);
– ppm: abbreviation for pages per minute (pages per minute), a measure that indicates the speed of the printer, that is, how many pages it can print per minute. Valley stress, however, that this measure is not accurate, since that manufacturers use different criteria for defining it. For example, there are those that tell you that a printer works to X ppm, but does not make it clear that this value is only hit on the print mode economical;
– cps: abbreviation for characters per second (characters per second), indicates the amount of letters, numbers and other symbols that the printer is able to print every second. It is a measurement commonly used in dot matrix printers;
– cpi: acronym for characters per pica (characters per pica), is a measure normally used in typography that indicates the amount character-per-pica, a system that divides a unit typographic twelve points (instead of ten, as in the decimal system). It is commonly used in conjunction with the measure cps in the description of dot-matrix printers;
Picolitro: this is a measure that is equivalent to one trillionth of a liter. In fact, it is hardly mentioned when the subject is the printer, but is used to measure the size of the drops ink.
Dot-matrix printers
One of the first types of printer that the market knew it was the printer matrix. Although it is increasingly in disuse due to the emergence printing technologies more sophisticated, it is still possible find dot-matrix printers being used in several establishments, since it is of a type quite durable and has low costs in relation to their supplies.
The dot-matrix printers (classified in a category called printers impact) are based, essentially, on two types of technology:
– Printer daisy: this type of printer has working similar to the classic machines of writing, being, currently, little common in the market. The device that is equivalent to the print head contains several characters in relief. This component moves with the character to be printed. Assuming, for example, that it is necessary to print the letter ‘A’, the mentioned mechanism will position the part that contains this letter on the paper. For printing to occur, the character, once positioned, press a tape with ink against the paper, in a move that is slightly reminiscent of a quick hit of a hammer;
– Printer needle: this is the most common type, being, therefore, simply referred to as a dot-matrix printer or even printer array of points. In this pattern, the print head it has small needles which, under the guidance electromagnetic, will forming the print as you push the ink ribbon against the paper. That is, in this technology, instead of the characters to be formed at once by impact, are consisting of small points. The advantage of this method is it is also possible to print images and graphics, although with certain limitation.
By using a schema of an impact on a ribbon with ink (which are cheap and usually pretty durable), the dot-matrix printers are not good for working with multiple colors, already that, for each color, it is necessary to have a tape exclusive or, still, a tape which is divided into various colors. Even so, the fidelity of colors is quite limited, for which reason it is conventionally using only the color black or shades of grey.
However, the dot matrix printers are useful for printing of documents based only on text or require copies. This is because the impact generated by the print head is enough so that it is possible the application of carbon paper, useful feature, for example, in the printing of tickets for the bus. On the other hand, the dot-matrix printers are generally noisy and, often, slow, depending on the type of print. This causes that their use is impractical in environments that require silence – libraries, for example. In addition, the quality of the prints is limited, since they cannot work with high resolutions.
Inkjet printers
The inkjet printers are the most used in your environment household and are also very common in offices, already we are able to offer impressions of excellent quality and color fidelity combined with a relatively low cost.
Unlike dot-matrix, ink-jet printers do not are impact. The printing is done through the emission of hundreds of ink droplets (typically in the size of 3 picolitre) issued from the lower openings in the print head. This last component is positioned on an axis that allows it to move left to the right, and vice-versa very quickly.
For the printing process itself, the ink-jet printers tell them, basically, with three technologies:
– Thermal (Bubble Jet): in this technology, a small amount ink is subjected to very high temperature to form small bubbles. The heating causes these to suffer pressure and are expelled by the nozzles of the print head. This is how the ink gets to the paper. When this process is finalized, the space left by the bubble is then filled again by a small amount of ink and, then, the whole procedure is repeated. This technology has been patented by Canon is used by companies such as HP and Lexmark.
A curiosity in relation to the technology Bubble Jet: there are rumors that his emergence happened by accident, when a researcher studying a formula of the ink and, without wanting to, he left an iron solder warm to touch at the needle of a syringe filled with the liquid. The heating caused the needle made drops of the ink were expelled almost immediately. The accident was then studied the point of turning into a technology of printing;
– Piezo-electric: this is a technology very used by Epson. In it, the print head uses a crystal piezo-electric output to a tiny compartment the ink. The crystals of the piezo-electric generate a small amount of energy when they get a physical strength, but the opposite also occurs: if you receive a small amount of electrical energy, the crystal moves. In the head print, this drive is used and, when the crystal back to her place, a small amount of ink comes out by opening existing there.
The technology Piezo-electric offers several advantages, such as allow the use of pigments which cannot suffer heat to change its properties when heated, for example. On the other hand, can represent a high cost to repair when the head print damage, as this usually finds on the printer and not the cartridges. To say, however, which of these two technologies of inkjet printing is best is a difficult task, as both are constantly improved to provide quality prints combined with a low cost;
– Continuous Ink jet (Continuous Inkjet – CIJ): this is a variation a bit more sophisticated, to be used for packaging printing products, for example. In this type of equipment, a continuous flow of ink passes through a crystal piezo-electric which divides it into tens of thousands of small drops. Each one of them receives electrical charge and, on that account, ends up being attracted by panels also electrically loaded that contains the material to receive the print. The drops not used in the process – many times, the majority of them – are “recycled”.
Color scheme of ink-jet printers
Much study has been (and is) dedicated in the formation of colors in the prints, particularly in technologies the ink jet. The color scheme used in the printers is CMYK, acronym for the colors cyan (Cyan), magenta (Magenta), yellow (Yellow), and black (blacK). This system is applied to the printers because the combination of their colors it is able to generate virtually any other colour of your noticeable to the human eye.
It is for this reason that in the printers inkjet, for example, it is common to find cartridges in the four colors mentioned. It is also common to find printers that work only with two cartridges, one for black color and the other for the colors cyan, magenta, and yellow. In fact, the combination of these three colors is able to generate the black color, but manufacturers prefer to using a unique cartridge of that color to provide better quality print, not to mention that it would be costly and a big waste to use the colored inks to generate prints only in black.
Although they are less common, it is also possible to find printers that work with six cartridges. In this case, the additional colors are usually the light cyan and light magenta.
Laser printers
The laser printers are also part of the category of non impact and are widely used in the corporate environment, already that offer prints of excellent quality, you are able to quickly print, they work making little noise and enable high volumes impressions are associated with low costs. The operation of these printers is similar to photocopiers (in Brazil, also known as “machines xerox”, but in fact, Xerox is the name of the company that popularized this type of device).
The laser printers come with a kind of drum (or cylinder) coated by a material that permits the application of a load electrostatic. Assuming, for example, that the logo of AbbreviationFinder should be printed, a laser to “shape” the image on the drum leaving the points that the represent with a positive charge. When the “mold” of the information to be printed is formed, that area receives a material powder very fine and pigmented so-called toner that, by its time, has a negative charge and is distributed by a bearing present in its receptacle for storage. This causes the toner to be attracted by points that form the image to be printed, already that these have a positive charge (load negative and positive attract each other, as in a magnet).
In the next step, the sheet of paper which receives the impression is placed in contact with the cylinder, but, rather, receives a positive charge in a intensity greater than that of the mold image on the drum. A rotation makes the last pass across the paper, transferring the toner for it. Finally, a mechanism formed by two cylinders of name fuser (or the fuser in English), coated material that prevents the adhesion of toner, “plays” heat in the paper at the same time in that the press (that is why the paper almost always comes out hot of the printer). In this way, the toner is fixed on paper and printing is completed.
It is up to the printer then prepare the drum for the next print. For this, it is necessary to clean it any “leftover” toner not used in printing previous. In printers of the HP brand, for example, a kind blade removes the waste toner to dispose of them in a suitable container.
Although the majority of laser printers to work only with the color black, it is not difficult to find printers of type working with color. For this, manufacturers can use various methods, such as applying a toner of each color by time, or even combine all the colors into a container interim to then apply them at once on paper. As the work with color in laser printers is more complex, this type of equipment is priced much higher in comparison to the printers that print only in black (monochrome).
Other types of printers
Although the dot-matrix printers, ink-jet and laser are the the most common, there are several printing technologies available in the market. The following are some of them:
– Solid ink printer: this printer type is commonly used in the industrial environment. As the name indicates, your ink it is formed by a kind of solid block. In print, the ink to be used goes through a process called “change of phase” (phase change), where it is melted to be applied to the paper. Its fixation in the latter is made by means of a fuser, as is the case in laser printers;
Printers for sublimation ink: this type of printer is used a lot in applications that involve graphic arts, and has a mode of operation quite interesting: uses the movies that work with the CMYK colors. A process of heating this causes the material to turn into gas and “stick” on paper and then freeze. In general, this default printer requires a type of paper specially prepared for this purpose;
– Printer wax thermal: this type of printer you have functioning similar to the technology of sublimation ink and, for use with wax, if it seems even with the printers solid-ink. For the print to be generated, a kind of tape containing reels with the scheme colors CMYK in wax passes for a head that has a series of pins. These make with the wax to melt and stick on the paper. This type of printer is widely used in transparencies professionals;
– Plotters: this type of equipment is capable of dealing with printouts with high quality graphics and dimensions great. In the market, there are several types of plotters, but two types are the most common: the plotters of clipping and printing plotters (the latter also tend to be called digital printers), in addition to the plotters that combine both categories. The plotters cutting only work by cutting designs into specialty papers, being useful to the work of application of adhesive, for example. In turn, the printing plotters are able to print in materials of large dimensions, such as posters and industrial plants. In this case, usually the plotter uses a printing technology the ink jet cartridges.
Page description languages
How is it that a printer can reproduce on paper a material any created on the computer? Are charts, tables, texts font variable, color, in short, a variety of information. This is possible thanks to the languages description page (page description language). It’s specifications communication that cause the printer to “learn” how and what to print. There are several of these languages, between they are:
– PostScript: this is taken as the first language description pages cross-platform and had the motivation the language InterPress, Xerox. Your appearance apparently if gave in the year 1985, by the hands of the company Adobe. One of its features is the ability to inform the content to be printed in vector form, allowing them to work in printers with varied rates of dpi. After going through various improvements, the PostScript is used up to the present day, not only for printing paper, but also to other applications that require description of pages;
– PCL: abbreviation for Printer Command Language, it is a page description language developed by HP. Its first version was created to work with dot-matrix printers, therefore, was quite limited. However, the release of several other versions causes the PCL to be used in modern printers today. This language is also able to work with a number of resolutions and transmits the instructions to the printer so that this mount an image line by line material;
– GDI: an acronym for Graphics Device Interface, it is a kind of language created by Microsoft for the generation and sending of information to devices output, among them, printers. Therein, almost all the work “mounting” the content to be printed is made in the operating system itself, thus saving resources of the printer. This causes the GDI to be particularly interesting to the printers for use in the home. Some printer manufacturers use the GDI for the Windows Printing System since this enables better management of printing.
Multifunctional
As the name indicates, multi-functional are the equipment that together two or more different functions. Thanks to this, they are an excellent option for who needs to save physical space on the table or to those seeking practicality.
There are, basically, two types of multi-purpose: for the that rely with the functions of the printer and the scanner; and, in addition to these resources, they also offer fax. Normally, these equipment can also be used as a copier: a user inserts a paper on the scanner of the multifunctional and, by means of a button or command, causes the equipment to print a copy of the scanned material.
As with the printers, “conventional”, the multinational may be based in technologies of ink jet or the laser, being that this last is more common in the corporate environment, for have higher price.
3D printers
Have you ever heard of 3D printer? As it is, you can seem somewhat surreal, but they are there! In fact, this type of the equipment is widely used in applications industrial, for the modeling of parts of vehicles, therefore example. They act as if they were the “sculptors and robot”.
These printers are capable of making three-dimensional models of the most varied objects. The materials used are also diverse: there are printers that use wax, cardboard, wire plastic, etc.
There are several types of 3D printers. Models known build the object layer by layer, superimposing them working individually on each one of them. But there are also printers that use a type of powder to set with material skin-tight, as well as equipment that shape objects from the heating of solid components.
Ending
When you reach the end of this article, you may still be wondering: which printer to buy? The answer to this question is not difficult. If you make prints possible, such as work academics, for example, it is better to opt for the printers ink jet, as they are inexpensive and offer great print quality, including color. On the other hand, if you print documents quite frequently, as it happens in offices, consider purchasing a laser printer. They are a little more expensive, but they print on a larger quantity, with better quality and speed, causing the spent with supplies to be smaller compared to the jet printers ink.
Depending on the case, it may be interesting to use both printers ink jet as laser printers. If you often print multiple documents per day, but most of them only uses the color black, it may not make sense to buy a color laser printer, just one that prints only with black toner. In this case, purchase an inkjet printer for the occasional color prints. This is a good way of saving resources.
The other types of printer have applications quite specific, therefore, the choice must be made with care preferably with the help of a specialist company, in the case of commercial applications, due to the costs involved.
Regardless of the equipment chosen, analyze their needs well before you make a print-out. This way, you save electricity, paper and ink (or a supply equivalent), doing good to your pocket and the environment.
