What does HUD stand for?

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HUD stands for Head-Up Display, a flight assistance instrument used in aircraft. It refers to a driver-centered, blind-operation, multi-functional instrument panel. Its function is to project important driving information such as speed and navigation onto the windshield in front of the driver, allowing the driver to see critical driving information like speed and navigation without having to lower or turn their head. More related information is as follows: 1. The head-up display first appeared in military aircraft, reducing the frequency with which pilots needed to look down at instruments, avoiding attention interruptions and loss of situational awareness. Due to the convenience of HUD and its ability to improve flight safety, civil aircraft have also followed suit in installing it. Cars have also begun to be equipped with HUD. 2. HUD utilizes the principle of optical reflection to project important flight-related information onto a piece of glass. This glass is located at the front of the cockpit, roughly at eye level with the pilot. The projected text and images are adjusted to a focal distance of infinity, allowing the pilot to easily integrate the external view with the data displayed by the HUD when looking forward through it. The design intent of HUD is to enable pilots to maintain a heads-up posture without needing to look down at instrument displays and data, reducing the risk of missing rapid changes in the external environment during the transition between looking down and up, as well as the delay and discomfort caused by constantly adjusting eye focus.