HUD (head up display) light path system capable of reducing TFT (thin-film transistor) sunlight pollution

Abstract

The invention relates to the technical field of HUD (head up display), and particularly discloses an HUD light path system capable of reducing TFT (thin-film transistor) sunlight pollution. The systemcomprises a TFT, a reflector, a free-form surface lens, a dust-proof film and a windshield glass, the reflector, the free-form surface lens, the dust-proof film and the windshield glass sequentiallyform a transflective light path, the reflector is a polarizing reflector and / or the dust-proof film is a polarizing thin-film, and sunlight enters the TFT along with an inverse light path of a reflection light path. If a common reflector of an existing HUD light path is replaced with the polarizing reflector PBS or an existing common dust-proof film is replaced with the polarizing thin-film, and the sunlight energy finally entering the TFT is lower than 25.46%. According to the system, sunlight finally entering the TFT can be greatly weakened and is about 40% of an existing HUD light path, andrapidly aging of the TFT caused by sunlight irradiation is relieved, so that the TFT is protected.

Description

technical field [0001] The present invention relates to the technical field of HUDs (all are windshield-type HUDs if not specifically stated), in particular to a HUD optical path system for reducing TFT solar light pollution. Background technique [0002] As a driving assistance system, HUD (Head Up Display) can display important vehicle parameters within the driver's line of sight, so that the driver can always obtain various driving-related information in the basic field of vision. kind of information. For example, in order to understand the current vehicle speed information, the driver no longer needs to turn his eyes to the instrument cluster, but can see the information through the HUD display directly in front of the driver's eyes, which improves the safety of vehicle driving. [0003] However, during the use of the HUD, sunlight (which can be decomposed into 50% P light and 50% S light) can enter the TFT along the reverse direction of the light path. In a typical HU...

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Problems solved by technology

[0004] When the sun shines on the windshield, the windshield reflects 17% to 18% of the S light (assumed to be 18% here), and the remaining 50% of the P light and 32% of the S light enter the HUD optical path. The efficiency is about 86%, and the reflection efficiency of the flat mirror is 90%, so the solar energy finally entering the TFT is 57.1212% (=100%*(100%-18%)*86%*90%*90%), a large amount Sunlight enters the TFT, which causes the temperature of the TFT to rise, and it is easy to cause the threshold voltage of the TFT to change rapidly with the bias stress, causing the display of the LCD panel to be chaotic, and the mobility will also change, which affects the resolution, and the long-term bias stress makes the device's The threshold is prone to drift, and TFT threshold drift will directly cause changes in the brightness of pixels, affecting the overall display quality and service life

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