Vacuum Fluorescent Display technology was invented in 1950s. In 1959, Philips made the first vacuum fluorescent indicator ever. Shortly after that, in 1962, the very first single-digit VFD digital display component was made in Japan. After LED started to take over, VFD has been becoming outdated since 1990s. But it is still being used in many applications nowdays.
Instead of the appearance of a tube, it is implemented in flat and high resolution form. VFD is widely used in automotive, high-end instruments, hi-fi audio, and smart devices, thanks to its advantages, including high brightness, unique color, high customizability, and not requiring backlight. You will mostly probably have seen them in a car audio display, Blu-ray player, benchtop multimeter, supermarket cash register, etc.