Ghosting-elimination HUD (head up display) optical path system used with polarized sunglasses

Abstract

The invention relates to the technical field of HUD and particularly discloses a ghosting-elimination HUD (head up display) optical path system used with polarized sunglasses. The system comprises a light source module and a reflection module, the light source module emits P polarized light, the reflection module comprises a reflector module and automotive windshield glass, the reflector module isarranged in HUD, and the automotive windshield glass allows P light reflection and S light transmission. The system has advantages that by adoption of the automotive windshield glass in a three-layerstructure which comprises a glass inner surface, a P light reflecting layer and a glass outer surface, P light reflection and S light transmission can be realized, S light is not filtered when a driver wears the polarized sunglasses, and accordingly influences on image observation are avoided; in addition, the system has no requirement on inner and outer surface angles of the windshield glass, and the windshield glass is not limited to be wedged glass, so that low manufacturing difficulty and low cost are realized; by cooperation of the P light reflection windshield glass and the P light emergence HUD, ghosting in image projection is avoided, and requirements on HUD internal optical path and structural design are low.

Description

technical field [0001] The invention relates to the technical field of HUD, in particular to a HUD optical path system which can be used with polarized sunglasses and eliminate ghost images. Background technique [0002] When light enters the glass from the air, refraction (transmission) and reflection will occur on the glass surface. The ratio of refracted light to reflected light is related to the incident angle. figure 1 The relationship curves of amplitude reflectance, light intensity reflectance and incident angle show that: the larger the incident angle, the more reflected light, and the ratio of P light and S light in the reflected light is changing, as shown in figure 2 As shown, when the incident angle reaches Brewster's angle i 0 When , the reflected light is basically S light, and all P light is transmitted. As the incident angle further increases, the proportion of reflected light will further increase, but the reflection proportion of S light will increase fas...

AI Technical Summary

Problems solved by technology

[0005] Ordinary windshield works with HUD, the reflected light of windshield is S light, and S light is filtered when the driver wears sunglasses, which affects the driver's observation image

Ordinary windshield glass adopts ordinary PVB, the inner and outer surfaces of the glass are parallel, and the main image is separated from the secondary image, which is easy to cause ghosting, such as Figure 4

To solve the problem of ghosting, the windshield glass can use wedge-shaped PVB, the thickness of the top glass is greater than the thickness of the bottom glass, and the main image and the secondary image overlap, such as Figure 5 , but the wedge-shaped glass processing is limited by the process, the production cost is high, and the wedge angle will restrict the HUD design, making the design more difficult

[0006] The wedge-shaped glass can only eliminate ghosting at a certain angle, but cannot completely eliminate the projection in the entire projection area, and the wedge-shaped glass will impose requirements on the projection distance of the HUD, making the design more difficult

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