Printers

Printers produce hard copies printed on permanent material. It is called hard copy because it is tangible and can not be easily changed.  
There are two categories of printers, 
  • impact and 
  • non impact printers.
  Impact Printers
The Dot matrix printer is an example of an impact printer because it uses tiny dots to produce letters and graphics. They make a lot of noise and are slow.  
Some examples of Dot matrix printers are the Epson LX300, Epson LX780 and the Citizen Prodot 24.
Ink Jet printers.
 These are examples of a non-impact printer since they use nozzles to spray characters on to the page. They are between the dot matrix and laser printers in terms of speed and quality. Some examples are Canon BJC 620, HP 610C, HP 590C, Epson Stylus Colour 300 and the HP 859Cix.


Laser Jet printers use the principle of a photocopier and use a laser beam to print characters on to a page. They are faster and more expensive. They are also an example of a non-impact printer. High quality text and graphics are produced. Some examples are HP LaserJet 1100, HP LaserJet 2100, HP LaserJet 4L, HP LaserJet 5L and the Epson EPL 5700.

 
Do the following activity after learning about the mouse and list the printers that are installed in your computer.
 
3D Laser Printer

 

Comments

Post a Comment

Popular posts from this blog

Pen Input

Image
With pen input , users write, draw, and tap on a flat surface to enter input. The surface may be a monitor, a screen, a special type of paper, or a graphics tablet.  A light pen is handheld input device that can detect the presence of light. To select objects on the screen, a user presses the light pen against the surface of the screen or points the light at the screen and then presses a button on the pen.  A stylus is a small metal or plastic device that looks like a tiny ink pen but uses pressure instead of ink.   Some mobile computers and nearly all mobile devices have touch screens that recognize pen input. Most of these devices include a pressuresensitive digital pen or stylus. Pressure-sensitive digital pens typically provide more functionality than a stylus, featuring electronic erasers and programmable buttons. Computers and mobile devices often use handwriting recognition software that translates the handwritten lett...
Read more

Laptop, Tablets and Palmtop Computers

Image
The second type of computer that you may be familiar with is a laptop computer. Laptops are battery or AC-powered personal computers that can be easily carried and used in a variety of locations be a car, a taxi or airjet.    Example Laptop Computer The primary benefit of a laptop computer is its small size and easy portability . They use special screens, rather than the traditional bulky VDUs (Visual Display Units), which allows for longer battery life as well as portability. A laptop computer is sometimes called a notebook computer because of its size. Notebooks and Palmtop computers A newer term, “Notebooks”, simply indicates a VERY small laptop. These are especially popular with salespersons on the move or people giving presentations. While they tend to still be more expensive than an equivalent Desktop computer, they can now match the power of a Desktop computer. Palmtops are even smaller computers which can literally...
Read more

Measuring Memory

Image
Information is stored in the form of bytes.   A byte is a unit of memory in a computer and this byte represents either a character e.g. B or two digits e.g. 12.   These bytes are formed from bits.   Bits, or Binary Digits, may have one of two values.   These are represented by 0 or 1, true or false, but will actually be the presence or absence of magnetisation. Relationship between Bits, Bytes, Kilobytes, Megabytes and Gigabytes A Bit is the smallest element of data storage.   Bits grouped together form bytes.   With the ASCII code a combination of 8 bits form 1 byte.   For example when you type a letter ‘a’ the computer will understand that as a combination of zeros and ones e.g. 01100001.   The following indicates the relationship between different data units 8 bits = 1 byte 1024 (2 10 ) bytes = 1 Kilobyte 1 048 576 (2 20 ) bytes = 1024 Kilobytes = 1 Megabyte 1 073 741 824 bytes = 1024 Megabytes = 1 G...
Read more