It was while working as a journalist that 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.
He presented the first production of the ballpoint pen at the Budapest International Fair in 1931. 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.
During World War II, Bíró was forced to flee the Nazis. In 1943, the brothers moved to Argentina. On 10 June, they filed another patent, issued in the US as 2,390,636 Writing Instrument,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, which has sold more than 100 billion ballpoint pens worldwide. In November of that same year, promoter Milton Reynolds introduced a gravity-fed pen to the U.S. market. The Reynolds Pen was a sensation for a few years, until its reputation for leaking and competition from established pen manufacturers overtook it. Bíró's patent was based on capillary action, which caused ink to be drawn out of the pen as it was deposited on the paper. Because the Reynolds workaround depended on gravity, it did not infringe but required thinner ink and a larger barrel. László Bíró died in Buenos Aires, Argentina in 1985. Argentina's Inventors' Day is celebrated on Bíró's birthday, 29 September.
On 29 September 2016, the 117th anniversary of his birth, Google commemorated Bíró with a Google Doodle for "his relentless, forward-thinking spirit".
According to wikipedia
Van Nguyen (collect ) - WORLD RECORDS UNION - WORLDKINGS ( source of photo : internet )