Dot matrix printing, [1] sometimes called impact matrix printing, is a computer printing process in which ink is applied to a surface using a relatively low-resolution dot matrix for layout. Dot matrix printers are a type of impact printer that prints using a fixed number of pins or wires [2] [3] and typically use a print head that moves back and forth or in an up-and-down motion on the page and prints by impact, striking an ink-soaked cloth ribbon against the paper. They were also known as serial dot matrix printers. [4] Unlike typewriters or line printers that use a similar print mechanism, a dot matrix printer can print arbitrary patterns and not just specific characters.
The perceived quality of dot matrix printers depends on the vertical and horizontal resolution and the ability of the printer to overlap adjacent dots. 9-pin and 24-pin are common; this specifies the number of pins in a specific vertically aligned space. With 24-pin printers, the horizontal movement can slightly overlap dots, producing visually superior output (near letter-quality or NLQ), usually at the cost of speed.
Dot matrix printing is typically distinguished from non-impact methods, such as inkjet, thermal, or laser printing, which also use a bitmap to represent the printed work. These other technologies can support higher dot resolutions and print more quickly, with less noise. Unlike other technologies, impact printers can print on multi-part forms, allowing multiple copies to be made simultaneously, often on paper of different colors. [5] They can also employ endless printing using continuous paper that is fanfolded and perforated so that pages can be easily torn from each other.
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History of printing |
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In 1925, Rudolf Hell invented the Hellschreiber, an early facsimile-like dot matrix –based teletypewriter device, [6] patented in 1929.
Between 1952 and 1954 Fritz Karl Preikschat filed five patent applications [7] [8] for his teletype writer 7 stylus 35 dot matrix aka PKT printer, [6] a dot matrix teletypewriter built between 1954 and 1956 in Germany. Like the earlier Hellschreiber, it still used electromechanical means of coding and decoding, but it used a start-stop method (asynchronous transmission) rather than synchronous transmission for communication. [6] In 1956, while he was employed at Telefonbau und Normalzeit GmbH (TuN, later called Tenovis), the device was offered to the Deutsche Bundespost (German Post Office), which did not show interest. When Preikschat emigrated to the US in 1957 he sold the rights to utilize the applications in any country (except the USA) to TuN. The prototype was also shown to General Mills in 1957. An improved transistorized design [6] became the basis for a portable dot matrix facsimile machine, which was prototyped and evaluated for military use by Boeing around 1966–1967. [9] [10]
IBM marketed its first dot matrix printer in 1957, the same year that the dye-sublimation printer entered the market. [12] [13]
In 1968, the Japanese manufacturer OKI introduced its first serial impact dot matrix printer (SIDM), the OKI Wiredot. The printer supported a character generator for 128 characters with a print matrix of 7 × 5. It was aimed at governmental, financial, scientific and educational markets. For this achievement, OKI received an award from the Information Processing Society of Japan (IPSJ) in 2013. [14] [15] [16]
In 1970 [17] Digital Equipment Corporation (DEC) introduced an impact dot matrix printer, the LA30, as did Centronics (then of Hudson, New Hampshire): the Centronics 101. [18] [19] [20] The search for a reliable printer mechanism led it to develop a relationship with Brother Industries, Ltd of Japan, and the sale of Centronics-badged Brother printer mechanisms equipped with a Centronics print head and Centronics electronics. Unlike Digital, Centronics concentrated on the low-end line printer marketplace with their distinctive units. In the process, they designed the parallel electrical interface that was to become standard on most printers until it began to be replaced by the Universal Serial Bus (USB) in the late 1990s.
DEC was a major vendor, albeit with a focus on use with their PDP minicomputer line. [21] Their LA30 30 character/second (CPS) dot matrix printer, the first of many, was introduced in 1970. In the mid-1980s, dot-matrix printers were dropping in price, [3] [lower-alpha 1] and began to outsell daisywheel printers, due to their higher speed and versatility. [22] The Apple ImageWriter was a popular consumer dot matrix printer in the 1980s until the mid-1990s.
In the 1970s and 1980s, dot matrix impact printers were generally considered the best combination of cost and versatility, and until the 1990s were by far the most common form of printer used with personal and home computers. [23]
Increased pincount of the printhead from 7, 8, 9 or 12 pins to 18, 24, 27, or 36 permitted superior print quality, which was necessary for success in Asian markets to print legible CJKV characters. [24] Epson's 24-pin LQ-series rose to become the new de facto standard, at 24/180 inch (per pass – 7.5 lpi). Not only could a 24-pin printer lay down a denser dot-pattern in a single pass, it could simultaneously cover a larger area and print more quickly. Although the text quality of a 24-pin was still visibly inferior to a true letter-quality printer such as a daisy wheel or laser printer, print quality was greatly superior to a 9-pin printer. As manufacturing costs declined, 24-pin printers gradually replaced 9-pin printers.
By the dawn of the 1990s, inkjet printers became more common as PC printers. [25] [26]
Dot matrix printing uses a print head that moves back-and-forth, or in an up-and-down motion, on the page and prints by impact, striking an ink-soaked cloth ribbon against the paper, much like the print mechanism on a typewriter. However, unlike a typewriter or daisy wheel printer, letters are drawn out of a dot matrix, and thus, varied fonts and arbitrary graphics can be produced.
Each dot is produced by a tiny metal rod, also called a "wire" or "pin", which is driven forward by the power of a tiny electromagnet or solenoid, either directly or through small levers (pawls). [27] Facing the ribbon and the paper is a small guide plate named ribbon mask holder or protector, sometimes also called butterfly for its typical shape. It is pierced with holes to serve as guides for the pins. The plate may be made of hard plastic or an artificial jewel such as sapphire or ruby.
The portion of the printer that contains the pin is called the print head. When running the printer, it generally prints one line of text at a time. The printer head is attached to a metal bar that ensures correct alignment, but horizontal positioning is controlled by a band that attaches to sprockets on two wheels at each side which is then driven with an electric motor. [28] This band may be made of stainless steel, phosphor bronze or beryllium copper alloys, nylon or various synthetic materials with a twisted nylon core to prevent stretching. Actual position can be found out either by dead count using a stepper motor, rotary encoder attached to one wheel, or a transparent plastic band with markings that is read by an optical sensor on the printer head (common on inkjets).
Because the printing involves mechanical pressure, dot matrix printers can create carbon copies and carbonless copies. [29]
Although nearly all inkjet, thermal, and laser printers also print closely spaced dots rather than continuous lines or characters, it is not customary to call them dot matrix printers. [27]
Dot matrix printers have one of the lowest printing costs per page.[ citation needed ]
They are able to use fanfold continuous paper with tractor holes.
Dot matrix printers create noise when the pins or typeface strike the ribbon to the paper, [30] and sound-damping enclosures may have to be used in quiet environments.
They can only print lower-resolution graphics, with limited color performance, limited quality, and lower speeds compared to non-impact printers. [31] [32] [33]
The common serial dot matrix printers use a horizontally moving print head. [34] The print head can be thought of featuring a single vertical column of seven or more pins approximately the height of a character box. In reality, the pins are arranged in up to four vertically or/and horizontally slightly displaced columns in order to increase the dot density and print speed through interleaving without causing the pins to jam. Thereby, up to 48 pins [35] can be used to form the characters of a line while the print head moves horizontally. The printing speed of serial dot matrix printers with moving heads varies from 30 [36] to 1550 characters per second (cps). [37]
In a considerably different configuration, so called line dot matrix printers [38] or line matrix printers use a fixed print head almost as wide as the paper path utilizing a horizontal line of thousands of pins for printing. Sometimes two horizontally slightly displaced rows are used to improve the effective dot density through interleaving. While still line-oriented, these printers for the professional heavy-duty market effectively print a whole line at once while the paper moves forward below the print head. Line matrix printers are capable of printing much more than 1000 cps, resulting in a throughput of up to 800 pages per hour.
A variation on the dot matrix printer was the cross hammer dot printer, patented by Seikosha in 1982. [39] The smooth cylindrical roller of a conventional printer was replaced by a spinning, fluted cylinder. The print head was a simple hammer, with a vertical projecting edge, operated by an electromagnet. Where the vertical edge of the hammer intersected the horizontal flute of the cylinder, compressing the paper and ribbon between them, a single dot was marked on the paper. Characters were built up of multiple dots.
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Unlike the LA30's 80-column, uppercase-only 5 x 7 dot matrix, DEC's product line grew. New models included:
The DECwriter LA30 was a 30 character per second dot matrix printing terminal introduced in 1970 by Digital Equipment Corporation (DEC) of Maynard, Massachusetts [41]
It printed 80 columns of uppercase-only 7 × 5 dot matrix characters across a unique-sized paper. The printhead was driven by a stepper motor and the paper was advanced by a noisy solenoid ratchet drive. The LA30 was available with both a parallel interface (LA30-P) and a serial interface (LA30-S); however, the serial LA30 required the use of fill characters during the carriage-return. In 1972, a receive-only variation named LA30A became available.
The LA30 was followed in 1974 by the LA36, [42] which achieved far greater commercial success, [43] becoming for a time the standard dot matrix computer terminal. The LA36 used the same print head as the LA30 but could print on forms of any width up to 132 columns of mixed-case output on standard green bar fanfold paper. [43] The carriage was moved by a much-more-capable servo drive using a DC electric motor and an optical encoder / tachometer. The paper was moved by a stepper motor. The LA36 was only available with a serial interface but unlike the earlier LA30, no fill characters were required. This was possible because, while the printer never communicated at faster than 30 characters per second, the mechanism was actually capable of printing at 60 characters per second. During the carriage return period, characters were buffered for subsequent printing at full speed during a catch-up period. The two-tone buzz produced by 60-character-per-second catch-up printing followed by 30-character-per-second ordinary printing was a distinctive feature of the LA36, quickly copied by many other manufacturers well into the 1990s. Most efficient dot matrix printers used this buffering technique.
Digital technology later broadened the basic LA36 line into a wide variety of dot matrix printers.
The DEC LA50 was designed to be a "compact, dot matrix" [21] printer. When in graphic mode (as opposed to text mode), the printhead can generate graphic images. When in (bitmap) graphics mode, the LA50 can receive and print Sixel [lower-alpha 2] graphics format.
The Centronics 101 [44] (introduced 1970) was highly innovative and affordable at its inception. Some selected specifications:
The IBM 5103 [45] was the only IBM printer that could be attached to the IBM 5100, an early day portable computer. Printing was 8 DPI, 10 pitch, 6 LPI, and capable of printing bidirectionally from a 128-character set. Two models were offered: [46] 80 and 120 characters per second. [47]
Near Letter Quality mode—informally specified as almost good enough to be used in a business letter [48] —endowed dot-matrix printers with a simulated typewriter-like quality. By using multiple passes of the carriage, and higher dot density, the printer could increase the effective resolution. In 1985, The New York Times described the use of "near letter-quality, or NLQ" as "just a neat little bit of hype" [3] but acknowledged that they "really show their stuff in the area of fonts, print enhancements and graphics."
NLQ printers could generally be set to print in "draft mode", in which case a single pass of the print head per line would be used. This produced lower quality print at much higher output speed.
In 1985, PC Magazine wrote "for the average personal computer user dot matrix remains the most workable choice". [11] At the time, IBM sold Epson's MX-80 as their IBM 5152. [49]
Another technology, inkjet printing, which uses the razor and blades business model (give away the razor handle, make money on the razor blade) [50] has reduced the value of the low cost for the printer: "a price per milliliter on par with liquid gold" for the ink/toner. [51]
In June 1978, the Epson TX-80/TP-80, [52] an 8-pin dot-matrix printer mainly used for the Commodore PET computer, was released. This and its successor, the 9-pin MX-80/MP-80 (introduced in 1979–1980), [53] sparked the popularity of impact printers in the personal computer market. [54] The MX-80 combined affordability with good-quality text output (for its time). Early impact printers (including the MX) were notoriously loud during operation, a result of the hammer-like mechanism in the print head. The MX-80 even inspired the name of a noise rock band. [55] The MX-80's low dot density (60 dpi horizontal, 72 dpi vertical) produced printouts of a distinctive "computerized" quality. When compared to the crisp typewriter quality of a daisy-wheel printer, the dot-matrix printer's legibility appeared especially bad. In office applications, output quality was a serious issue, as the dot-matrix text's readability would rapidly degrade with each photocopy generation.
Initially, third-party printer enhancement software offered a quick fix to the quality issue. General strategies were:
Some newer dot-matrix impact printers could reproduce bitmap images via "dot-addressable" capability. In 1981, Epson offered a retrofit EPROM kit called Graftrax to add this to many early MX series printers. Banners and signs produced with software that used this ability, such as Broderbund's Print Shop, became ubiquitous in offices and schools throughout the 1980s.
As carriage speed increased and dot density increased (from 60 dpi up to 240 dpi), with some adding color printing, additional typefaces allowed the user to vary the text appearance of printouts. Proportional-spaced fonts allowed the printer to imitate the non-uniform character widths of a typesetter, and also darker printouts. 'User-downloadable fonts' gave until the printer was powered off or soft-reset. The user could embed up to two NLQ custom typefaces in addition to the printer's built-in (ROM) typefaces.
The desktop impact printer was gradually replaced by the inkjet printer. When Hewlett-Packard's USpatent 4578687 expired on steam-propelled photolithographically produced ink-jet heads in 2004, the inkjet mechanism became available to the printer industry. For applications that did not require impact (e.g. carbon-copy printing), the inkjet was superior in nearly all respects: comparatively quiet operation, faster print speed, and output quality almost as good as a laser printer. By 1995, inkjet technology had surpassed dot matrix impact technology in the mainstream market and relegated dot matrix to niche applications. [56]
As of 2021 [update] , dot matrix impact technology remains in use in devices and applications such as:[ citation needed ]
Thermal printing is gradually supplanting them in some of these applications, but full-size dot-matrix impact printers are still used to print multi-part stationery. For example, dot matrix impact printers are still used at bank tellers and auto repair shops, and other applications where use of tractor feed paper is desirable such as data logging and aviation. Most of these printers now come with USB interfaces as a standard feature to facilitate connections to modern computers without legacy ports.
In computing, a printer is a peripheral machine which makes a durable representation of graphics or text, usually on paper. While most output is human-readable, bar code printers are an example of an expanded use for printers. Different types of printers include 3D printers, inkjet printers, laser printers, and thermal printers.
A line printer prints one entire line of text before advancing to another line. Most early line printers were impact printers.
Laser printing is an electrostatic digital printing process. It produces high-quality text and graphics by repeatedly passing a laser beam back and forth over a negatively charged cylinder called a "drum" to define a differentially charged image. The drum then selectively collects electrically charged powdered ink (toner), and transfers the image to paper, which is then heated to permanently fuse the text, imagery, or both to the paper. As with digital photocopiers, laser printers employ a xerographic printing process. Laser printing differs from traditional xerography as implemented in analog photocopiers in that in the latter, the image is formed by reflecting light off an existing document onto the exposed drum.
Inkjet printing is a type of computer printing that recreates a digital image by propelling droplets of ink onto paper and plastic substrates. Inkjet printers were the most commonly used type of printer in 2008, and range from small inexpensive consumer models to expensive professional machines. By 2019, laser printers outsold inkjet printers by nearly a 2:1 ratio, 9.6% vs 5.1% of all computer peripherals.
A dot matrix is a 2-dimensional patterned array, used to represent characters, symbols and images. Most types of modern technology use dot matrices for display of information, including mobile phones, televisions, and printers. The system is also used in textiles with sewing, knitting and weaving.
Daisy wheel printing is an impact printing technology invented in 1970 by Andrew Gabor 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 three times faster. Daisy wheel printing was used in electronic typewriters, word processors and computers from 1972. The daisy wheel is so named because of its resemblance to the daisy flower.
In computing, a parallel port is a type of interface found on early computers for connecting peripherals. The name refers to the way the data is sent; parallel ports send multiple bits of data at once, as opposed to serial communication, in which bits are sent one at a time. To do this, parallel ports require multiple data lines in their cables and port connectors and tend to be larger than contemporary serial ports, which only require one data line.
Centronics Data Computer Corporation was an American manufacturer of computer printers, now remembered primarily for the parallel interface that bears its name, the Centronics connector.
The ImageWriter is a product line of dot matrix printers formerly manufactured by Apple Computer, Inc., and designed then to be compatible with their entire line of computers. There were three different models introduced over time, which were popular among Apple II and Mac owners.
Giclée describes digital prints intended as fine art and produced by inkjet printers. The term is a neologism, ultimately derived from the French word gicleur, coined in 1991 by printmaker Jack Duganne. The name was originally applied to fine art prints created on a modified Iris printer in a process invented in the late 1980s. It has since been used widely to mean any fine-art printing, usually archival, printed by inkjet. It is often used by artists, galleries, and print shops for their high quality printing, but is also used generically for art printing of any quality.
IEEE 1284, also known as the Centronics port, is a standard that defines bi-directional parallel communications between computers and other devices. It was originally developed in the 1970s by Centronics before its IEEE standardization.
Seiko Epson Corporation, commonly known as Epson, is a Japanese multinational electronics company and one of the world's largest manufacturers of printers and information- and imaging-related equipment. Headquartered in Suwa, Nagano, Japan, the company has numerous subsidiaries worldwide and manufactures inkjet, dot matrix, thermal and laser printers for consumer, business and industrial use, scanners, laptop and desktop computers, video projectors, watches, point of sale systems, robots and industrial automation equipment, semiconductor devices, crystal oscillators, sensing systems and other associated electronic components.
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 such as an IBM Selectric.
The Actrix computer, released in 1983 by Actrix Computer Corporation, was a Zilog Z80-based transportable personal computer running CP/M-80 V2.2. It was initially released as the Access Computer, made by Access Matrix Computer Corporation, but both the company and its product changed names after trademark disputes.
ESC/P, short for Epson Standard Code for Printers and sometimes styled Escape/P, is a printer control language developed by Epson to control computer printers. It was mainly used in dot matrix printers and some inkjet printers, and is still widely used in many receipt thermal printers. During the era of dot matrix printers, it was also used by other manufacturers, sometimes in modified form. At the time, it was a popular mechanism to add formatting to printed text, and was widely supported in software.
Continuous stationery (UK) or continuous form paper (US) is paper which is designed for use with dot-matrix and line printers with appropriate paper-feed mechanisms. Other names include fan-fold paper, sprocket-feed paper, burst paper, lineflow, tractor-feed paper, and pin-feed paper. It can be single-ply or multi-ply, often described as multipart stationery or forms. Continuous stationery is often used when the final print medium is less critical in terms of the appearance at the edges, and when continuously connected individual sheets are not inconvenient for the application. Individual sheets can be separated at the perforation, and sheets also have edges with punched holes, which also can be removed at the perforation.
The IBM 6640 printer was one of the world's first office ink jet printers. It was originally announced as the 46/40 but later renamed as 6640, as part of the Office System/6 word processing range in 1976.
The DECwriter series was a family of computer terminals from Digital Equipment Corporation (DEC). They were typically used in a fashion similar to a teletype, with a computer output being printed to paper and the user inputting information on the keyboard. In contrast to teletypes, the DECwriters were based on dot matrix printer technology, one of the first examples of such a system to be introduced. Versions lacking a keyboard were also available for use as computer printers, which eventually became the only models as smart terminals became the main way to interact with mainframes and minicomputers in the 1980s.
IBM 3740 Data Entry System was a data entry system that was announced by IBM in 1973. It recorded data on an 8" diskette, a new recording medium from IBM, for fast, flexible, efficient data entry to either high-production, centralized operations or to decentralized, remote operations. The "Diskette" was more commonly known as an 8-inch floppy disk.
Near letter-quality (NLQ) printing is a process where dot matrix printers produce high-quality text by using multiple passes to produce higher dot density. The tradeoff for the improved print quality is reduced printing speed. Software can also be used to produce this effect. The term was coined in the 1980s to distinguish NLQ printing from true letter-quality printing, as produced by a printer based on traditional typewriter technology such as a daisy wheel, or by a laser printer.
Dot matrix and inkjet printers share one key characteristic — both make images out of small dots. With a dot matrix printer, a pin presses through a ribbon to make an impact on the page. Inkjet printers have an electrical signal that causes a microscopic quantity of ink to squirt onto the page.
A report on Computer peripheral devices ... impact printers were generally considered the best combination of expense and versatility, and until the 1990s they were ...
In the early 1990s, inkjet printer sales started a dramatic growth that would last over ten years.
Beginning in the early 1990s, inkjet printers ...
Digital Equipment Corporation (DEC) designs and manufacturers many of the peripheral devices offered with PDP-11's. As a designer and manufacturer of peripherals, DEC can offer extremely reliable equipment... The LA30 DECwriter, a totally DEC-designed and built teleprinter, can serve as an alternative to the Teletype.
DEC brought the LA36 to market in 1974
The LA36 DECwriter II was the companys first commercially successful ... The printer mechanism uses a dot-matrix technique to print 132 columns of text across standard 14 inch computer forms
two previously announced products: the IBM 5103 models 11 and 12 bidirectional, matrix printers