Letter-quality printer
Encyclopedia
A letter-quality printer was a form of computer impact printer that was able to print with the quality typically expected from a business typewriter
Typewriter
A typewriter is a mechanical or electromechanical device with keys that, when pressed, cause characters to be printed on a medium, usually paper. Typically one character is printed per keypress, and the machine prints the characters by making ink impressions of type elements similar to the pieces...

 such as an IBM
IBM
International Business Machines Corporation or IBM is an American multinational technology and consulting corporation headquartered in Armonk, New York, United States. IBM manufactures and sells computer hardware and software, and it offers infrastructure, hosting and consulting services in areas...

 Selectric.

A letter-quality printer operates in much the same fashion as a typewriter
Typewriter
A typewriter is a mechanical or electromechanical device with keys that, when pressed, cause characters to be printed on a medium, usually paper. Typically one character is printed per keypress, and the machine prints the characters by making ink impressions of type elements similar to the pieces...

. A metal or plastic printwheel embossed with letters, numbers, or symbols strikes an inked ribbon, depositing the ink on the page and thus printing a character.

Over time, several different technologies were developed including automating ordinary typebar typewriter mechanisms (such as the Friden Flexowriter
Friden Flexowriter
The Friden Flexowriter was a teleprinter, a heavy duty electric typewriter capable of being driven not only by a human typing, but also automatically by several methods including direct attachment to a computer and by use of paper tape....

), daisy wheel printer
Daisy wheel printer
Daisy wheel printers use an impact printing technology invented in 1969 by David S. Lee at Diablo Data Systems. It uses interchangeable pre-formed type elements, each with typically 96 glyphs, to generate high-quality output comparable to premium typewriters such as the IBM Selectric, but two to...

s where the type
Typesetting
Typesetting is the composition of text by means of types.Typesetting requires the prior process of designing a font and storing it in some manner...

 is moulded around the edge of a wheel, and "golf ball" printers where the type is distributed over the face of a globe-shaped printhead (including automating IBM Selectric mechanisms such as the IBM 2741
IBM 2741
The IBM 2741 was a printing computer terminal introduced in 1965.It combined a ruggedized Selectric typewriter mechanism with IBM SLT electronics and an RS-232-C serial interface. It operated at about 14.1 characters per second with a data rate of 134.5 bits/second...

 terminal). The daisy wheel and Selectric-based printers offered the advantage that the typeface
Typeface
In typography, a typeface is the artistic representation or interpretation of characters; it is the way the type looks. Each type is designed and there are thousands of different typefaces in existence, with new ones being developed constantly....

 was readily changeable by the user to accommodate varying needs.

These printers were referred to as "letter-quality printers" during their heyday, and could produce text which was as clear and crisp as a typewriter (though they were nowhere near the quality of printing press
Printing press
A printing press is a device for applying pressure to an inked surface resting upon a print medium , thereby transferring the ink...

es). Most were available either as complete computer terminal
Computer terminal
A computer terminal is an electronic or electromechanical hardware device that is used for entering data into, and displaying data from, a computer or a computing system...

s with keyboards, or as print-only devices. Because of its low cost, the daisy wheel printer became the most successful.

Letter-quality printers, however, were slow, noisy, incapable of printing graphics or images, generally limited to monochrome, and limited to a fixed set (usually one) of typefaces, though certain font effects like underlining and boldface could be achieved by overstriking. Nowadays, printers using non-impact printing (for example laser printer
Laser printer
A laser printer is a common type of computer printer that rapidly produces high quality text and graphics on plain paper. As with digital photocopiers and multifunction printers , laser printers employ a xerographic printing process, but differ from analog photocopiers in that the image is produced...

s, inkjet printer
Inkjet printer
An inkjet printer is a type of computer printer that creates a digital image by propelling droplets of ink onto paper. 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 up to thousands of...

s, and other similar means) have replaced traditional letter-quality printers in most applications.

See also

  • Diablo 630
    Diablo 630
    The Diablo 630 was a daisy wheel printer sold by the Diablo Data Systems division of the Xerox Corporation from 1980. The printer was capable of letter-quality printing; that is, its print quality was equivalent to the quality of an IBM Selectric typewriter, Selectric-based printer, or similar...

     — the archetypal daisy wheel printer
    Daisy wheel printer
    Daisy wheel printers use an impact printing technology invented in 1969 by David S. Lee at Diablo Data Systems. It uses interchangeable pre-formed type elements, each with typically 96 glyphs, to generate high-quality output comparable to premium typewriters such as the IBM Selectric, but two to...

  • Teleprinter
    Teleprinter
    A teleprinter is a electromechanical typewriter that can be used to communicate typed messages from point to point and point to multipoint over a variety of communication channels that range from a simple electrical connection, such as a pair of wires, to the use of radio and microwave as the...

The source of this article is wikipedia, the free encyclopedia.  The text of this article is licensed under the GFDL.
 
x
OK