Rotarykynät

Rotarykynät, often referred to as "ballpoint pens" in English, are writing instruments that utilize a rolling ball mechanism to dispense ink. The ball, typically made of brass, steel, or tungsten carbide, sits in a socket at the tip of the pen. As the pen is moved across a writing surface, the ball rotates, picking up ink from a reservoir within the pen and transferring it to the paper.

This design allows for a consistent and smooth ink flow, making rotarykynät a popular choice for everyday writing tasks. The ink used in rotarykynät is usually oil-based and quick-drying, which helps to prevent smudging. The ink reservoir is typically a tube that contains a large supply of ink, allowing for extended writing periods before needing a refill or replacement.

The invention of the rotarykynä is largely credited to László Bíró, a Hungarian journalist, who patented his design in 1938. Bíró's innovation addressed issues with earlier pen designs, such as fountain pens, which could leak or blot. Rotarykynät became widely adopted due to their reliability, affordability, and ease of use. They are manufactured in a vast array of styles, colors, and ink types, catering to diverse writing preferences and applications.