The connection through which a printer is connected to a computer is referred as the printer interface.
Printers use various interfaces, such as a parallel interface, network interface, Universal Serial Bus (USB) interface, serial interface, IEEE 1394/FireWire interface, wireless interface, and Small Computer System Interface (SCSI) interface, to communicate with a computer.
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Parallel Interface
Parallel printer cables use a 36-pin Centronics connector on the end that attaches to a printer, and a male DB-25 connector on the end that attaches to a computer's parallel port. The Institute of Electrical and Electronics Engineers (IEEE) created a specification for an IEEE 1284 cable, which is used for bidirectional data transfer. A standard cable allows data transfers from a computer to a printer, but the IEEE 1284 cable allows the printer to send data back to the computer. Parallel printer cables are normally limited to 10 feet in length.
Network Interface
Printers that can be configured on the network are known as network printers. These printers are
equipped with a network interface card (NIC), configured with an IP address, and are able to execute print jobs sent by remote computers on the network. A network printer appears to the network as another host and typically uses the RJ-45 port to connect to the network. You can connect network printers using a network cable. To attach a network cable to the network printer, connect one end to the RJ-45 port in the printer and other end to any available RJ-45 port on the network.
Some printers are connected to a central print server to enable central maintenance and configuration.
Using a print server, the printer drivers for all operating systems can be installed in a central location, ready for installation on any networked computer.
USB Interface
The USB interface allows you to connect the printer to your computer’s USB port. The USB port provides faster transfer rates, and it is hot-swappable and supported by most of the available operating systems. A USB 1.0 interface allows the data transfer speed of 1.5 megabits per second (Mbps), and a USB 2.0 interface allows the data transfer speed of 480 Mbps. This interface is widely used and is the fastest interface for printing from a computer.
Serial Interface
Serial interface printers tend to be slow, due to the speed of the serial interface. The data transfer speed of serial interface is slow because this interface transfers data one bit at a time. The only advantage of using a serial interface for printers is that you can use a longer cable to connect the printer to a computer.
IEEE 1394/FireWire
The IEEE 1394/FireWire port is a high-speed serial-transmission port that allows devices to be hot-plugged. A FireWire port can be seen in modern laptops. The high data transfer rates make it the port of choice for transferring digital image files.
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Wireless Interface
A wireless interface is used to connect printers without using a network cable. Wireless interface
technologies, such as Bluetooth, 802.11b, and infrared, are becoming popular for connecting a printer to a computer. Bluetooth is a wireless technology that provides convergence between a variety of wireless-enabled devices, such as computers, printers, cellular telephones, Personal Digital Assistants (PDAs), and other Bluetooth-supported devices. The IEEE 802.11b is a wireless standard and is referred to as Wi-Fi. Most printers have a built-in 802.11b interface that is used to connect printers on a wireless network.
Infrared is also used as a wireless interface to establish communication with other infrared compatible devices. There are many infrared devices available, such as printers and laptops. The infrared devices work in a limited area of one meter and require a clear view of other devices with which they are communicating.
SCSI Interface
SCSI printers can print at speeds faster than parallel port printers. However, SCSI printers are rarely used because SCSI is a relatively expensive interface.
Recap
Printers are divided into two categories: impact printers and non-impact printers.
Impact printers use a print head that strikes on the ribbon to print characters on paper.
Non-impact printers use a print head that does not strike the paper.
A laser printer is a type of non-impact printer that produces high quality text and graphics on a plain paper.
An inkjet is a type of non-impact printer. These printers use liquid ink and produce high quality output.
Dot-matrix printers are often used for printing multi-part forms, also known as carbon copy printing.
In multi-part form printing, two or more papers are interleaved with sheets of carbon paper or a carbonless form for duplicate printing.
Thermal printers are non-impact printers and use a heated head to enable images to appear on a special paper.
Thermal printers are mainly divided into two categories: thermal wax transfer printer and direct thermal printer.
The toner cartridge holds the toner, which is a combination of carbon compound, polyester resins, and iron particles.
The corona is part of the laser printing system that transfers the toner from the drum to the paper.
Black and white printers use a single black ink cartridge. Color printers may use a black cartridge and a partitioned cartridge containing cyan-, yellow-, and magenta-colored inks.
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Parallel printer cables use a 36-pin Centronics connector on the end that attaches to a printer, and a male DB-25 connector on the end that attaches to a computer's parallel port.
Printers that can be configured on the network are known as network printers. A network printer appears to the network as another host and typically uses the RJ-45 port to connect to the network.
The USB interface is used for serial data transfers and allows high transfer speeds. The hot-swap capabilities of these interfaces make them attractive for use with printers.
Serial interface printers can be slow, due to the speed of the serial interface.
The IEEE 1394/FireWire port is a high-speed serial-transmission port that allows devices to be hot-plugged.
Wireless interface is used to connect printers without using a network cable. Wireless interface technologies, such as Bluetooth, 802.11b, and infrared, are becoming popular.
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