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In Germany, Dr.
Rudolf Hell is best known as the inventor of a kind of text-only fax machine.
He invented his “writing telegraph” in 1929, and it was commercialized in
1931 by Siemens. Another of Hell’s early inventions was the radio-
direction-finder for airplanes. He continued to develop the fax and related
wirephoto technologies for many years. Within the prepress industry, the first of his inventions was the Klischograph, a device that optically scanned a piece of film and engraved a “stereotype,” the raised halftone plate used for letter-press printing of photos. It was introduced at Drupa in 1954. Prior to the Klischograph, a slow chemical-etching process was the only method available for making stereotypes. The demand for color printing soon led to the development of color scanners to create film separations for the Klischograph and, subsequently, for making offset plates. Hell became known around the world for color-separation scanners. One milestone was the introduction in 1970 of the highly successful DC300, the first laser drum scanner. The success of the Klischograph also led in another direction: the development of the Helioklischograph, a system for engraving gravure cylinders using electronically controlled diamond styli. This machine, which was driven from a separate film-scanning unit, was introduced in 1964. In the early 1980s, Scitex began driving Hell Helioklischographs from a computer-based page-assembly system, creating the first all-digital prepress workflow. Today, the Helioklischograph, sold by Hell Gravure Systems, remains one of the primary tools of the gravure industry. Many people know about Hell’s role in the development of color scanning, but his contributions to the field of digital typesetting were at least as great. In 1965, Hell introduced the Digiset typesetting system. It was the first device to produce characters on a CRT entirely from digital masters. In the U.S., it was licensed to RCA and sold as the VideoComp. This machine introduced many of the concepts that would be central to all subsequent digital typesetting devices. Dr. Hell retired from active management of the company in the early 1970s, though he remained on the board. Dr. Hell died in the age of 100 in 2002. In 1990, the company was merged with Linotype (to become Linotype-Hell) and it was subsequently acquired by Heidelberg. Today, only Hell Gravure Systems still bears the founder’s name. |
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| Colorgraph | Cromagraph DC 300 | Helio-Klischograph |
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| Digiset 40 T1 | Cromagraph DC 300 | Telebild Laser-Receiver TM4006 |
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| Fax Machines |
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| Siemens Hell small fax machine KF 108 (1956) | Siemens Hell small fax KF 108 (1956) |
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| Hell Fax HF 1048 (1976) CCITT | Siemens Fax (under license 1976) CCITT |
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| Explanations concerning the individual inventions | |
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Klischograph (printing block and engraving machine ) Typical HELL technology - an image is electronically scanned and engraved onto Astralon-based materials using gravure technology, giving rise to an original printing plate. The first Klischograph from 1952 revolutionised technology in prepress. |
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| Fax device | |
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The world-wide first practicable small
fax device is a German invention from Kiel. Dr.-Ing. Rudolf Hell
developed the standard Siemens Hell paper fax KF 108 in 1956
with drum technology. A fax transmission in the format DIN A5 lasts
approx.. 4 minutes. Over complex mechanics with the help of
Saphir-rotary the ink is brought on the usual typewriting paper in
the A5 format. A KF 108 even then still faxes , if the devices of
the modern times are long functionless. It is unfortunately not
compatible to today's fax devices. Siemens built the equipment in a
typically German soundness: Everything torsionally stiff running in
ball bearings and is plentifully oversized. This device redefined
the meaning of telegraphic transfers. Videos to download ((abt. 100-600 KB) Rightclick, save media as..): Video1 Video2 Video3 |
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| HELLschreiber | |
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The Hellschreiber or Feldhellschreiber
was a facsimile-based teleprinter invented by Dr. Rudolf Hell. It
has since been emulated on computer sound cards by radio amateurs;
the resulting mode is referred to as Hellschreiber, Feld-Hell, or
simply Hell. Hellschreiber transmits text by dividing each column into 7 pixels, and transmitting them sequentially, starting at the lowest pixel. A black pixel is transmitted as a signal, and a white pixel is transmitted as silence. This takes place at a rate of 122.5 baud. Since the text was printed on continuous rolls, the number of columns is indefinite. |
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The original Hellschreiber machine was
a mechanical device, so therefore it was possible to send "half-pixels".
The right ends of the loops in B, for instance, could be shifted a
little, so as to improve the readability. Any on-signal could in any
case last no shorter than 8 ms, however, both because of having to
restrict the occupied bandwidth on the radio, but also for reasons
having to do with the mechanical makeup of the receiving machinery. All implementations of Hellschreiber print all received columns twice, one below the other (but they are not transmitted twice). This is to compensate for slight timing errors that are often present in the equipment, and causes the text to slant. The received text can look like two identical texts coming out one below the other, or a line of text coming out in the middle, with chopped-off lines above and below. In either case, at least one whole letter can be read at all times. Improvements that came as a result of software implementation: Depicting the received signal as shades of gray instead of monochrome, thereby making it much easier to read weak signals. Changing to a different font. Here is one mode that is truly international and independent of character sets: any thing that can be depicted as markings within a 7 pixels high grid, can be transmitted over the air. Hellschreiber has also spawned a number of variants over the years, many of them due to radio amateur efforths in the 1990s. Examples of them are: PSK Hell, FM Hell, Duplo Hell, C/MT Hell, S/MT Hell, and Slowfeld. |
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| Videos to download ((abt. 100-600 KB) Rightclick, save media as..): Video1 Video2 | |
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Vario-Klischograph The Vario-Klischograph from 1958, designed for letterpress printing, can master scale changes. This device produced the very first color calculated reproduction of slides and overhead transparencies. It became an all-time bestseller. Helio-Klischograph This machine from 1964 is the perfect solution to publication printing. It contains 6 - 8 engraving systems and is equipped with 10 scanning heads, each available as separate components of the engraver and scanner. Chromagraph (The first laser-scanner) The Chromagraph DC 300 became the first completely digital scanner, making easy modification of fonts and overlapping image layers possible. Chromacom The first assembly and image processing system
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