A typewriter is a mechanical, electromechanical, or electronic device with a set of "keys" that, when pressed, cause characters to be printed on a Document, usually Paper.
In the late 19th and the start of the 20th century a person who operated such a device was sometimes also called a "typewriter," but it then became more common to call the person a typist.
A typewriter has a keyboard, with keys for each of the characters in its font. The method by which the typewriter actually marks the paper now varies as greatly as types of computer printers do, but until the end of the 20th century was by the impact of a metal (or, later, metallized Plastic) type element against an "inked" ribbon which caused ink to be deposited on the paper. Carbon paper was sometimes inserted between multiple pieces of paper, so the impact also caused duplicate characters to be printed on each layer of paper.
Although still popular with a few writers and in less developed countries, the typewriter has largely been replaced by the Word processor application on a Personal computer.
[image] In 1829 William Austin Burt patented a machine called the "Typographer." Like many of these other early machines, it is sometimes listed as the "first typewriter;" the Science Museum (London) describes it merely as "the first writing mechanism whose invention was documented," but even that claim may be excessive since Turri's machine is well known. Even in the hands of its inventor it was slower than handwriting. Burt and his promoter John D. Sheldon never found a buyer for the patent, and it was never commercially produced. Because it used a dial to select the character instead of having an individual key for each character, it was an "index typewriter" rather than a "keyboard typewriter", if it is to be considered a typewriter at all. From 1829 to 1870, many printing or typing machines were patented by inventors in Europe and America, but none went into commercial production. Charles Thurber developed multiple patents; his first in 1843 was developed as an aid to the blind. See Charles Thurber's 1845 Chirographer, as an example.
The first true typewriter as it is in use today was invented in 1855 by Italian Giuseppe Ravizza called " CEMBALO SCRIVANO o MACCHINA DA SCRIVERE A TASTI". Other say that the inventor was the Austrian Peter Mitterhofer 1864 but was never produced commercially. Mitterhofer continued to improve his original model and created 5 different enhanced typewriters until 1868. In 1865 Rev. Malling Hansen of Denmark produced the Hansen Writing Ball which went into commercial production in 1870 and was the first commercially sold typewriter. It was a success in Europe and was reported being used in offices in London as late as 1909. Additionally, Hansen used a Solenoid escapement to return the carriage on some of his models, and was responsible for the first "electric" typewriter.
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In 1867 Christopher Sholes, Carlos Glidden, and Samuel W. Soule invented another typewriter. The Sholes and Glidden typewriter was the first device that allowed an operator to type substantially faster than a person could write by hand. The patent (US 79,265) was sold for $12,000 to Densmore and Yost, who made an agreement with E. Remington and Sons (then famous as a manufacturer of sewing machines), to commercialize what was known as the Sholes and Glidden Type-Writer. Remington started production of their first typewriter on March 1, 1873 in Ilion, New York. Another early typewriter manufacturer was Underwood.
The ability to view what is typed as it is typed is taken for granted today. In all early keyboard typewriters, however, the typebars struck upwards against the bottom of the platen. Thus, what was typed was not visible until the typing of subsequent lines caused it to scroll into view. The difficulty with any other arrangement was ensuring that the typebars fell back into place reliably when the key was released. This was eventually achieved with ingenious mechanical designs, and so-called "visible typewriters" were introduced in 1895. Surprisingly, the older style continued in production as late as 1915.
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In the original design style, now known as a "mechanical" or "manual" typewriter, each key was attached to a Typebar that had the corresponding letter molded into its other end. When a key was struck briskly and firmly, the typebar hit a ribbon (usually made of inked fabric) stretched in front of a cylindrical platen that moved back and forth. The paper was rolled around by the typewriter's platen which was then rotated by a lever (the "carriage return" lever at the far left) to each new line of text. Some typewriters used ribbons that were inked in black and red, each a stripe half the width and the entire length of the ribbon. A lever allowed switching between colors for typing bookkeeping entries, where negative amounts had to be in red.
IBM and Remington electric typewriters were the leading models until IBM introduced the IBM Selectric typewriter, which replaced the typebars with a spherical typeball (more correctly, "element"), slightly smaller than a golf ball, with the letters molded on its surface. The Selectric used a system of latches, metal tapes, and pulleys driven by an electric motor to rotate the ball into the correct position and then strike it against the ribbon and platen. The typeball moved laterally in front of the paper instead of the former platen-carrying carriage moving the paper across a stationary print position.
The typeball design had many advantages, especially in eliminating of "jams" when more than one key was struck at once, and in the ability to change the typeball, allowing multiple fonts to be used in a single document. Selectric mechanisms were widely incorporated into computer terminals in the 1970s, because the typing mechanism was fast and jam-free; could be initiated by a short, low-force mechanical action; and did not require the movement of a heavy "type basket" in order to shift between lower- and upper-case.
Later models of Selectrics replaced inked fabric ribbons with "carbon film" ribbons that had a dry black or colored powder on a "once-thru" clear plastic tape. These could be used only once but they were in a cartridge that was simple to replace. They also introduced auto-correction, where a sticky tape in front of the print ribbon could remove the black-powdered image of a typed character, and introduced selectable "pitch" so that the typewriter could be switched among pica ("10 pitch"), elite ("12 pitch"), and sometimes agate ("15 pitch"), even in one document. Even so, all Selectrics were monospaced -- each and every character was the same width. Although IBM had produced a successful typebar-based machine, the IBM Executive, with proportional spacing, no proportionally spaced Selectric office typewriter was ever introduced. There was, however, a much more expensive proportionally spaced machine called the Selectric Composer which was considered a typesetting machine rather than a typewriter.
The final major development of the typewriter was the "electronic" typewriter. Most of these replaced the typeball with a daisy wheel mechanism (a disk with the letters molded on the outside edge of the "petals"). A plastic daisy-wheel was much simpler and cheaper than the typeball but wore out more easily. Some electronic typewriters were in essence dedicated word processors with internal memory and cartridge or diskette external memory-storage devices. Unlike the Selectrics and earlier models, these really were "electronic" and relied on integrated circuits and multiple electromechanical components.
These typically incorporated keyboards from existing models of typewriters and the printing mechanism of dot-matrix printers. The generation of teletypes with impact pin-based printing engines was not adequate for the demanding quality required for typed output. Newly developed, thermal transfer technologies used in thermal label printers had become technically feasible for typewriters.
IBM produced a series of typewriters called Thermotronic with letter-quality output and correcting tape along with printers tagged Quietwriter. Brother extended the life of their typewriter product line with similar products.
The development of these proprietary printing engines provided the vendors with exclusive markets in consumable ribbons and the possibility to use standardised printing engines with varying degrees of electronic and software sophistication to develop product lines.
The increasing dominance of personal computers and the introduction of low-cost, truly high-quality, laser and Inkjet printer technologies eventually displaced dedicated typewriters.
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In some countries where personal computers are not ubiquitous, one may go to the public square and find individuals who gather there with their old but sturdy typewriters. These individuals rent out their services as on-the-spot letter writers, accepting dictation from their customers, who may be illiterate or who simply do not own a typewriter.
The QWERTY layout is thought by some to be an inefficient one, since it requires a touch-typist to move his or her fingers between rows to type the most common letters. A popular story suggests that it was used for early typewriters because it was inefficient; it slowed a typist down so as to reduce the frequency of the typewriter's typebars from wedging together and jamming the machine. A more likely explanation is that the QWERTY arrangement was designed to reduce the likelihood of internal clashing by placing commonly used combinations of letters farther away from each other inside the machine. This allowed the user to actually type faster without jamming. Unfortunately, no definitive explanation for the QWERTY keyboard has been found, and typewriter aficionados continue to debate the issue.
Interestingly, the word "typewriter" is one of the longest single English words that can be typed on a single row (namely, the top row) of a QWERTY keyboard ('proprietory', 'protereotype' and 'rupturewort' are longer). One plausible story behind the unusual layout is that it was designed so that the salesmen could quickly type the word “typewriter”, thereby impressing their prospective customers. It seems unlikely however, that the engineers would have designed the keyboard layout around a simple sales gimmick.
A number of radically different layouts, such as the Dvorak keyboard, have been proposed, but these have not been able to displace the QWERTY layout; their proponents claim considerable advantages, but so far inertia has prevented any mainstream adoption.
Many old typewriters do not contain a separate key for the numeral 1, and some even older ones also lack the numeral zero. Typists learned the habit of using the lowercase letter l for the digit 1, and the uppercase O for the zero. Some still carry the habit of using the letter l instead of the numeral 1 with them when typing on a computer, sometimes leading to errors, especially when working with numerical Data.
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Corrections, were, of course, necessary, and a variety of methods and technologies were used.
The traditional method involved the use of a special typewriter eraser. The typewriter eraser was made of fairly hard, stiff rubber, containing abrasive material. It was in the shape of a thin, flat disk, approx. 2 inches (50 mm) in diameter by 1/8 inch (3 mm) thick allowing for the erasure of individual typed letters. Business letters were typed on heavyweight, high-rag-content bond paper, not merely to provide a luxurious appearance, but also to stand up to erasure. Typewriter erasers were equipped with a brush for brushing away eraser crumbs and paper dust, and using the brush properly was an important element of typewriting skill, because if erasure detritus fell into the typewriter, a very small buildup could cause the typebars to jam in their narrow supporting grooves.
Erasing a set of carbon copies was particularly difficult, and called for the use of a device called an eraser shield to prevent the pressure of erasure on the upper copies from producing carbon smudges on the lower copies.
Paper companies produced a special form of typewriter paper called erasable bond (for example, Eaton's Corrasable Bond). This incorporated a thin layer of material that prevented ink from penetrating and was relatively soft and easy to remove from the page. An ordinary soft pencil eraser could quickly produce perfect erasures on this kind of paper. However, the same characteristics that made the paper erasable made the characters subject to smudging due to ordinary friction and deliberate alteration after the fact, making it unacceptable for business correspondence, contracts, or any archival use.
In the fifties and sixties, Correction fluid made its appearance, under brand names such as Liquid Paper, Wite-Out and Tipp-Ex. This was a kind of opaque white fast-drying paint which produced a fresh white surface onto which a correction could be re-typed. However, when held to the light, the covered-up characters were visible, as was the patch of dry correction fluid (which was never perfectly flat, and never a perfect match for the color, texture, and luster of the surrounding paper). The standard trick for solving this problem was Photocopying the corrected page, but this was possible only with high quality photocopiers, and was not practical with color letterheads. (However, high quality typists were smart enough to place the color letterhead stock in the copier, and photocopy the corrected typed-text-only-on-plain-paper document onto the color letterhead!)
Dry correction products (such as correction paper) under brand names such as Ko-Rec-Type were introduced in the seventies and functioned like white carbon paper. A strip of the product was placed over the letters needing correction, and the incorrect letters were retyped, causing the black character to be overstruck with a white overcoat. Similar material was soon incorporated in carbon-film electric typewriter ribbons; like the traditional two-color black-and-red inked ribbon common on manual typewriters, a black/white correcting ribbon became commonplace on electric typewriters.
The pinnacle of this kind of technology was the IBM Correcting Selectric. This machine, and similar products, incorporated a black/white ribbon and a character memory. With a single keystroke, the typewriter was capable of automatically reversing and overstriking the previous few characters with white cover-up. More modern typewriters have a similar feature, but use clear plastic film onto which ink is taken up and removed from the page.
As of 2005, Barbara Blackburn is the fastest typist in the world, according to The Guinness Book of World Records. Using the Dvorak Simplified Keyboard, she has maintained 150 word/min for 50 min, 170 word/min for shorter periods of time, and has been clocked at a peak speed of 212 word/min. Blackburn failed her typing class in high school, first encountered the Dvorak keyboard in 1938, quickly learned to achieve very high speeds, and occasionally toured giving speed-typing demonstrations during her secretarial career. She appeared on The David Letterman Show and was deeply offended by Letterman's comedic treatment of her skill.
Due to popular software named "Mavis Beacon Teaches Typing", many people have assumed that there is a woman named Mavis Beacon who is a very good typist. In reality, Mavis Beacon is a fictional promotional character.
Black/white computer printers have their "fingerprints" as well, but to less degree. Modern color printers and photocopiers typically add a steganographic pattern of minuscule yellow dots to the printout encoding the printer's Serial number.
Other forensic identification method can involve analysis of the ribbon ink.
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