1925
- Presentation of a TV broadcasting and receiving station (jointly with
   Prof. Dr. Dieckmann) at the trade exhibition in Munich

- Promotion: "Direct-Acting Radio Indicator for Aeronautics"

1927
- invention of the "light-electric image-splitter tube" for television

1929
- Founding of his own company in Neubabelsberg near Berlin
- Development of the "Hell-Schreiber"
- Patent "Device for the electrical transmission of characters"
   (Hell-Schreiber)
 
1931 

- Development of novel morse devices
- The Hell-writer is produced in large quantities at Siemens

1934
- Use of the Hell-writer in the news world

At the end of the Second World War the work was completely
destroyed, the new beginning dares Hell 1947 in Kiel-Dietrichsdorf

 

1949
- Beginning of the development of the wire photo devices

1950
- development and production of image transmission equipment for

   post, press, police, weather services

1951
- First attempts with the Klischee engraving machine  "Klischograph"

   lead one reorienting the graphics industry

1954

- Introduction of the Klischographen in newspaper companies
- Development of the Vario-Klischograph

1956
- Hell is launching the small fax machine KF108 on the market,

   Siemens produces it in large numbers

1958
- At the Drupa the Vario-Klischograph will be presented
- Colorgraph
 
1961
- Hell invents the Helio-Klischographen (scanning and engraving

   machine for the electromechanical engraving of gravure cylinders)

1963
- Chromagraph (scanner)

1964
- First telephoto receiver TM 830 with automatic development of the

   received images

1965
- For the first time, the public is informed about electronic lighting systems
  Digital storage. Thus, a new epoch of sentence technology is introduced
- Hell presented in July the Digiset, a setting machine, which decomposed
  with digital Fonts