Multifunction devices

A multifunction device (MFP) is a very useful thing, both for office work and for home use. The MFP consists of two devices - a printer and a scanner. Another device - a copy machine, is obtained from a bunch of the first two. Let us consider in more detail the characteristics of the printing device, which should be paid attention to when choosing multifunctional devices or individual printers:

Printing technology

All printers by print technology are divided into:

Inkjet

Inkjet technology is based on the injection of ink droplets onto paper through nozzles *. The resolution (and hence the print quality) of the printer depends on the number of nozzles.

Nozzles (nozzles) - microscopic holes in the carriage moving along a sheet of paper.

For the injection of a drop, either a special thermoelement is used, which pushes ink out due to the vapor formed during their heating, or a piezoelectric element, which ejects a drop by changing its dimensions under the action of electric current.

The main disadvantage of this technology is that the nozzles, being very small (the diameter is literally a few microns), tend to quickly clog with ink or dust. As a result, if several nozzles fail, the printer starts to “strip”.

Also quite significant disadvantage of inkjet printers is the high cost of consumables. The price of individual cartridges can reach up to half the entire cost of the device. For example, color cartridges for HP DeskJet inkjet printers now cost about 630 rubles, with the cost of the printer itself between 1,200 and 2,000 rubles, depending on the model.

The main advantages of inkjet printers are their cheapness (the price of the cheapest solutions starts at 1200 rubles) and the good quality of image printing.

Inkjet printers are best used at home if you do not need to print a large number of documents or images.

Laser

Now the most widespread laser printers and multifunction printers.

Printing in such a device is carried out at the expense of a laser emitting a beam and a special photodrum, which has the property of discretely (at different points in different ways) storing an electric charge on its surface. The laser beam, passing through special lenses and mirrors, hits the drum and “illuminates” its individual sections. The drum touches the toner cartridge during rotation and “sticks” ink on its “non-illuminated” areas, and peels off from the “exposed” ones. Then the toner is transferred to the paper by rolling it under the drum. Then the paper enters the “stove”, where the toner is fixed on the surface of the sheet under the action of temperature.

The advantages of this technology are a fairly high print speed, a large resource of cartridges, high reliability (non-drying ink), good print quality (especially texts), low cost of service.

The disadvantages of laser printers are, first of all, their price (especially color), as well as the worst quality of printing of images compared to other technologies.

Laser printers are great for both office and home use.

Matrix

Matrix (needle) printing technology is one of the oldest technologies. The principle of operation of such a printer is similar to a typewriter - a moving matrix with a set of 9, 18 or 24 needles, ink ribbon and paper under it. Needles, under the influence of an electromagnet, hit the ribbon with ink and leave points on the paper. Thus, an image consisting of a set of points is formed on a sheet. Although this technology is outdated, it is still used because of its unique features, such as:

a) multi-layer printing (printing simultaneously on several sheets of paper, "for carbon paper"

b) a high degree of “security” of printouts (due to the paper being forced by needles, the printed text is almost impossible to remove from the sheet)

C) ease of printing on long continuous media, such as ribbons.

The matrix printer is practically not suitable for printing texts or images. Such devices have found their application in various banks, public institutions, where printing of important documents, tickets, contracts, etc. is required.

Sublimation

These printers are in good demand with photographers and artists. Thanks to the thermal transfer technology used in such devices, printing can be made not only on paper, but also on various materials, such as, for example, fabrics or plastic.

Printing in a sublimation printer is carried out by evaporation of the dye from the multi-colored films. First, the print head is heated, which then moves along the film, evaporating the dye. Due to the high temperature, dye vapor penetrates the surface of the material.

Multifunction devices

The advantages of dye-sublimation printers are a fairly high print speed, small size of the device itself, image stability to the effects of moisture and sunlight.

The main disadvantage of such a printer is its high price, as well as the high cost of consumables.

Such a device is advisable to use in various advertising agencies or design studios where printing of a large number of images on various materials is required.

Print quality and speed

The print quality of a printer is characterized by its resolution (dpi, dots per inch - the number of dots printed on one square inch). For inkjet printers, an acceptable resolution is considered to be from 1,200 dpi, for laser printers - from 600. For high-quality photo printing, a printer with a resolution of at least 2,400 dpi is required.

Also important characteristic is the speed of printing. Naturally, the higher it is, the faster the print will go. It is worth noting that often manufacturers specify print speeds for poor print quality. In this case, with normal print quality, the speed will be slightly lower, about 2-3 pages per minute.

Format

Now the most common and universal format is A4. If you need to print on A3 format, you should choose a wide format printer.

Internal memory

Printer memory is required to place documents and images queued for printing. With a small amount of memory print speed will be quite low. For printing texts, 8 MB of memory is enough. For images or large files, you need a printer with a large amount of internal memory. There are also models that have built-in memory expansion.

Cartridges and their refills

When choosing a printer or MFP, you should consider the type of cartridges, their volume and the cost of refilling or full replacement. Note also that cartridges and toners filled with 30, 50 or 60% are supplied with the printers. So soon after the purchase you have to refill them or buy new ones. The laser printers also need replacing the drum unit. Its resource, of course, is much higher than the toner resource, but sooner or later it will also have to be changed.

Connect to computer

Now the most common and recommended is the USB interface.

Currently, the most common scanners are tablet. In such scanners, the original is placed on a transparent glass, covered with a white lid. Then a special lamp moves along the entire sheet and performs a scan. The light reflected from the document falls on a special CCD * or CIS * matrix, then on an ADC (Analog-to-Digital Converter) and is transmitted to a computer.

Most modern scanners work on CIS technology.

CCD (Couple-Charged Device) is a data reading technology based on CCD sensors (Charge Coupled Device). In the process of scanning, the original is illuminated with fluorescent lamps, after which the light reflected from the document is directed by means of a special optical system to light-sensitive elements, which convert the intensity of the received light into the corresponding voltage value.

CIS (Contact Image Sensor) is a technology in which the receiving element consists of a line of sensors that directly perceive the luminous flux reflected from the document. In such scanners, the optical system is completely absent, the receiving element is equal in width to the working scanning field, and the original is illuminated with a line of LEDs of three colors - red, green and blue.

The most common and cheapest at the moment are color single-pass A4 scanners with a resolution of 600 dpi and a color depth of 24 bits. This is quite enough for home use.

It is worth saying that when scanning photos to obtain a better image, it is recommended to use a scanner with a resolution of 1200 dpi.

The technical characteristics of the scanners indicate two optical resolution values, for example 600x1200 dpi, the horizontal is determined by the matrix, and the vertical by the number of engine steps per inch. The minimum value should be taken into account.

The speed of the copier MFP is determined by the speeds of the scanner and printer. Often it is equal to print speed.