László József Bíró (September 29, 1899 – October 24, 1985) was a Hungarian-Argentine inventor best known for patenting the first commercially successful modern ballpoint pen.
Early Life and Inspiration
Born into a Jewish family in Budapest, Hungary, Bíró worked as a journalist, editor, and painter. During his time as a journalist in the 1930s, he noticed a stark contrast between two types of ink: the ink used in newspaper printing presses dried almost instantly and left a smudge-free finish, while the ink used in traditional fountain pens took significantly longer to dry and smeared easily.
Attempting to solve this problem, Bíró tried filling a fountain pen with newspaper ink, but the liquid was too viscous and refused to flow through the pen’s nib. He realized that the traditional pen mechanism itself needed a complete redesign.

Inventing the Ballpoint Pen
The fundamental concept of using a rolling ball to distribute ink had been patented roughly 50 years earlier by American inventor John J. Loud, but Loud’s design was too coarse for paper and failed commercially.
Bíró, teaming up with his brother György (a chemist), perfected the design. They developed a specialized, quick-drying viscous ink and a new tip mechanism consisting of a tiny metal ball housed in a socket. As the pen moved across the paper, the ball rotated freely, picking up ink from the internal reservoir and depositing it evenly onto the page. Bíró officially patented this design in Paris in 1938.

Escape to Argentina and Global Success
As World War II escalated and anti-Semitic policies swept through Europe, Bíró and his brother fled the Nazis, relocating to Argentina in 1943. There, they filed a new patent and established “Biro Pens of Argentina” alongside their business partner Juan Jorge Meyne. The pen was marketed in Argentina as the “Birome”—a portmanteau of Bíró and Meyne.
The invention quickly gained traction. The British government licensed the design for the Royal Air Force, as the ballpoint pen was not reliant on pressure and functioned flawlessly at high altitudes where traditional fountain pens would leak. In 1945, the French manufacturer Marcel Bich purchased the patent rights from Bíró. Bich refined the manufacturing process and launched the Bic Cristal, catapulting the ballpoint pen into mass global production.
Legacy
While Bíró did not amass vast wealth from his invention, his name became synonymous with the tool he created. In many parts of the world, including the UK, Ireland, Australia, and Italy, ballpoint pens are simply referred to as “biros”. Today, Argentina celebrates its national Inventors’ Day on September 29, in honor of Bíró’s birthday.