The Inventors’ Day in Argentina has been celebrated since 1986 and is held yearly on September 29, the birthday of the inventor of the ballpoint pen, László József Bíró.
Bíró was born in Budapest, Hungary, in 1899 into a Jewish family. He presented the first production of the ballpoint pen at the Budapest International Fair in 1931. While working as a journalist in Hungary, he noticed that the ink used in newspaper printing dried quickly, leaving the paper dry and smudge-free. He tried using the same ink in a fountain pen but found that it would not flow into the tip, as it was too viscous. Working with his brother György, a chemist, he developed a new tip consisting of a ball that was free to turn in a socket, and as it turned it would pick up ink from a cartridge and then roll to deposit it on the paper. Bíró patented the invention in Paris in 1938.
In 1943 the brothers moved to Argentina. On 10 June they filed another patent, issued in the USA as US Patent 2,390,636, and formed Biro Pens of Argentina (in Argentina the ballpoint pen is known as birome). This new design was licensed for production in the United Kingdom for supply to Royal Air Force aircrew, who found they worked much better than fountain pens at high altitude.
In 1945 Marcel Bich bought the patent from Bíró for the pen, which soon became the main product of his Bic company.
Patent Information
Patent Number: 2,390,636
Patent Title: Writing instrument
Publication date: 11 Dec 1945
Filing date: 17 Jun 1943
Priority date: 17 Apr 1943
Inventors: Jozsef Biro Laszlo
Here is his US patent on the ballpoint pen
Source: https://en.wikipedia.org/wiki/L%C3%A1szl%C3%B3_B%C3%ADr%C3%B3