Flip Flap

A "flip flap," in its most common usage, refers to a type of mechanical display consisting of a grid of electromechanically operated flaps or vanes that rotate to display different characters or symbols. These displays are often used for public information displays, such as train schedules, airport flight information boards, and stock tickers.

The individual flaps are typically colored or printed with different characters on each side. An electromagnet or similar mechanism is used to flip the flap to show the desired side, revealing the appropriate character to the viewer.

Flip flap displays are known for their distinctive clicking or flapping sound as the characters change. While largely replaced by LED and LCD displays, they remain recognizable and are sometimes preferred for their retro aesthetic or readability in bright sunlight.

Beyond public displays, the term "flip flap" can also refer more generally to any device or mechanism that involves a component flipping or flapping. This usage is less common and typically context-dependent. For example, a children's toy involving flapping wings could be described using this term.