NAME OF THE INVENTOR:
Chester Carlson invented a dry printing process called Electrophotography, commonly known as a Xerox, in 1938. In 1953, the first high-speed printer was developed by Remington-Rand.
Using electrophotography as the basis for laser printers, the Xerox Palo Alto Research Center began development on the first laser printer, called EARS, in 1969 and completed it in 1971. While the inkjet printer was invented in 1976, it took until 1988, the release date of Hewlett-Packard’s DeskJet, for it to become available for use in the home. In 1992, Hewlett-Packard released the popular LaserJet 4, which was the first 600-by-600 dots per inch resolution printer.
In computing, a printer is a peripheral which produces a representation of an electronic document on physical media such as paper or transparency film. Many printers are local peripherals connected directly to a nearby personal computer. Individual printers are often designed to support both local and network connected users at the same time. Some printers can print documents stored on memory cards or from digital cameras and scanners. Multifunction printers (MFPs) include a scanner and can copy paper documents or send a fax; these are also called multi-function devices (MFD), or all-in-one (AIO) printers. Most MFPs include printing, scanning, and copying among their many features.
Types of Printer:
In General, There are only 4 Types of Printers:
- Inkjet Printers.
- Laser Printers.
- Thermal Printers.
- Dot Matrix Printers.
Lets see them all in detail.
Inkjet printing is a type of computer printing that creates a digital image by propelling droplets of ink onto paper, plastic, or other substrates. Inkjet printers are the most commonly used type of printer,and range from small inexpensive consumer models to very large professional machines that can cost tens of thousands of dollars, or more.
Laser printing is an electrostatic digital printing process that rapidly produces high quality text and graphics by passing a laser beam over a charged drum to define a differentially charged image. The drum then selectively collects charged toner and transfers the image to paper, which is then heated to permanently fix the image. As with digital photocopiers and multifunction printers (MFPs), laser printers employ a xerographic printing process, but differ from analog photocopiers in that the image is produced by the direct scanning of the medium across the printer’s photoreceptor. Hence, it proves to be a much faster process compared to the latter.
Thermal printing (or direct thermal printing) is a digital printing process which produces a printed image by selectively heating coated thermochromic paper, or thermal paper as it is commonly known, when the paper passes over the thermal print head. The coating turns black in the areas where it is heated, producing an image. Two-color direct thermal printers can print both black and an additional color (often red) by applying heat at two different temperatures.
04:Dot Matrix Printer:
Dot matrix printers forms characters & images using a series of small pins on a print head.Once a widely used micro computer printer, they are in –expensive & reliable but quite noisy. In general, they are used for tasks where high quality output is not required.
Advantages of a Printer:
The Advantages of a Printer are as Follows:
- Print Preview: You can see everything on hard copy whatever you see in computer monitor.
- Storage: You can store all the information in your file for future reference.
Disadvantages of a Printer:
The Disadvantages of a Printer are as Follows:
- Resource: Waste of Paper a Natural Resource.
- Time: Old Printers take longer to print.
- Ink: If the printer runs out of ink you will have to pay to refill it.
Connection of Printer by its Different Ports & Cables:
There are several different types of ports which uses the interface you need to connect your printers within different PC-OS, they are as follows:
- Serial Cable Connection.
- Parallel Cable Connection.
- Ethernet Connection.
- USB Cable Connection.
- Wireless Connection.
- Infrared Connection.
lets see them in Detail!
01) Serial Cable Connection:
Serial cables, which aren’t very popular for printers, use either a 9-pin or 25-pin connector.
Serial connections send data one bit at a time and are not susceptible to data skew.
The maximum length of a serial cable is 25 feet long.
02) Parallel Cable Connection :
The most popular method for connecting a printer to a computer was, for many years, the parallel port.
The end of the parallel cable that connects to the computer is a male DB-25 connector, and the end that connects to the printer is a male 36-pin Centronics connector.
The maximum length of a parallel cable is 10 feet long.
Any longer than that, and the cable runs the risk of crosstalk or data skew:
• Crosstalk is electrical interference from other equipment, fluorescent lights, and other cables.
• Data skew is the concept of the signals that travel down the different wires in the parallel cable not traveling at the same speed and thus arriving at the destination at different times. This results in the data being unreadable at the opposite end.
Parallel connections deliver data 8 bits at a time at a speed of approximately 150 Kbps.
Parallel printers and their cables should conform to the IEEE 1284 standard for parallel cables.
This standard addresses parallel communication to and from the device attached to the cable.
03) Ethernet Connection:
Network-based printers have built-in network cards that allow the printer to connect directly to the network.
The printer runs the TCP/IP protocol and is assigned an IP address so that it can participate on the network.
You can assign the IP address to the printer through the menu system of the printer.
After the IP address is assigned, you can typically manage the settings on the printer through a Web browser by typing the IP address of the network printer in the address line of the browser.
04) USB Cable Connection:
Most printers today purchased for home or small offices are USB printers that connect to the computer via a USB port.
USB has a number of benefits, including the fact that it is a Plug and Play technology (you can plug in the device without shutting down the system).
USB 1.1 has a transfer rate of 12 Mbps, USB 2.0 has a transfer rate of 480 Mbps, while USB 3.0 has a transfer rate of 5 Gbps!
The following are some key points to remember about USB:
• It is Plug and Play.
• You may connect 127 devices to a USB chain.
• You don’t need to configure ports, IRQs, or DMA channels for each device.
• USB 2.0 has a transfer rate of 480 Mbps, while USB 3.0 has a transfer rate of 5 Gbps.
05) Wireless Connection:
Many printers today allow you to connect the printer to the network using a wireless network connection.
Many modern printers support 802.11x wireless networking capabilities.
You can configure an IP address on the wireless printer (usually through software or through the menu system on the printer) and then connect to that wireless printer from any wireless or wired network client on the network.
Not only do printers support 802.11x printing capabilities, but many printers also support Bluetooth networking capabilities that allow you to connect to the printer over short distances.
06) Infrared Connection:
Connecting your printer to a system by using infrared technology lets your computer communicate wirelessly with the printer in much the same way you use a TV remote to change channels without getting off the sofa.
The infrared signal sent from the computer to the printer is carried as a beam of light, instructing the printer what to print.
To use an infrared printer, you need both an infrared transmitter/receiver connected to your computer and an infrared printer.
The three different types of infrared devices are
• Reflective Infrared: Transmitters send the signal to a central unit, which then redirects the commands to the printer. This allows a number of users to print to a single printer at one time.
• Line-of-Sight Infrared: With line-of-sight, the printer’s receiver must be in a direct line-of-site with the computer’s transmitter. If there is a break in the line-of-site, communication is lost.
• Scatter Infrared: Scatter infrared allows the signal to bounce off walls or ceilings (or even people) all the way to the printer’s receiver. The benefit is that you don’t lose communication like you do with line-of-sight. However, scatter infrared has limited range and transmission speeds.