Optical film, head up display, and vehicle
An optical film to proof a head up display (HUD) system against image-contamination by sunlight and against the heat of sunlight is applied in a vehicle. The optical film includes a transparent substrate, a transparent microstructure layer, and a plurality of light blocking layers which allow transmission outwards of image-light for the HUD but prevent the ingress of sunlight. The microstructure layer includes a base portion in direct contact with a surface of the substrate, and a plurality of protrusions protruding from the base portion toward a side away from the substrate. Each light blocking layer is mounted on a protrusion, and each light blocking layer includes an absorbing film that can absorb light or a reflective film that can reflect light, whilst allowing the transmission of outbound light for the image. The HUD using the optical film is not affected by sunlight and has prolonged life.
1 . An optical film, comprising:
a transparent substrate;
a transparent microstructure layer on the transparent substrate, the microstructure layer comprising a base portion having a predetermined thickness and in direct contact with a surface of the transparent substrate and a plurality of protrusions protruding from the base portion toward a side away from the transparent substrate; and
a plurality of light blocking layers, wherein each of the plurality of light blocking layers partially covers a corresponding one of the plurality of protrusions, and each of the plurality of light blocking layers comprises an absorbing film configured for absorbing light or a reflective film configured for reflecting light; each of the plurality of protrusions extends in a strip shape along a first direction, and the plurality of protrusions are distributed continuously along a second direction intersecting with the first direction; each of the protrusions is a triangular prism, and the triangular prism comprises a first side surface, a second side surface and a third side surface which are connected in sequence; each of the first, the second and the third side surfaces is a quadrilateral; the first side surface is in direct contact with the base portion, the corresponding one of the plurality of light blocking layers covers the second side surface, and the third side surface of the triangular prism is exposed.
2 . The optical film of claim 1 , wherein an angle between the second side surface and the third side surface ranges from 30° to 150°.
3 . A head up display (HUD), comprising:
a housing comprising an accommodating cavity and a light outlet formed in a wall of the housing and providing a light path from the accommodating cavity to an exterior of the housing;
a transparent cover mounted on the housing and located at the light outlet;
a picture generation unit in the accommodating cavity for emitting image light;
a reflection assembly in the accommodating cavity, the reflection assembly being configured for reflecting the image light from the picture generation unit to the light outlet; and
an optical film on the transparent cover, the optical film comprising:
a transparent substrate;
a transparent microstructure layer on the transparent substrate, the microstructure layer comprising a base portion having a predetermined thickness and in direct contact with a surface of the transparent substrate and a plurality of protrusions protruding from the base portion toward a side away from the transparent substrate; and
a plurality of light blocking layers, wherein each of the plurality of light blocking layers partially covers a corresponding one of the plurality of protrusions, and each of the plurality of light blocking layers comprises an absorbing film configured for absorbing light or a reflective film configured for reflecting light;
wherein the image light reflected by the reflection assembly is emitted from the optical film to a projection medium for imaging; each of the plurality of protrusions extends in a strip shape along a first direction, and the plurality of protrusions are distributed continuously along a second direction intersecting with the first direction; each of the protrusions is a triangular prism, and the triangular prism comprises a first side surface, a second side surface and a third side surface which are connected in sequence; each of the first, the second and the third side surfaces is a quadrilateral; the first side surface is in direct contact with the base portion, the corresponding one of the plurality of light blocking layers covers the second side surface, and the third side surface of the triangular prism is exposed.
4 . The HUD of claim 3 , wherein an angle between the second side surface and the third side surface ranges from 30° to 150°.
5 . The HUD of claim 3 , wherein the optical film is positioned such that an angle between the image light incident on the optical film and the third side surface ranges from 5° to 150°.
6 . The HUD of claim 3 , wherein the optical film is positioned such that an angle of ambient light incident on the optical film and the second side surface ranges from 5° to 150°.
7 . A vehicle, comprising:
a windshield; and
a head up display (HUD), comprising:
a housing comprising an accommodating cavity and a light outlet formed in a wall of the housing and providing a light path from the accommodating cavity to an exterior of the housing;
a transparent cover mounted on the housing and located at the light outlet;
a picture generation unit in the accommodating cavity for emitting image light;
a reflection assembly in the accommodating cavity, the reflection assembly being configured for reflecting the image light from the picture generation unit to the light outlet; and
an optical film on the transparent cover, the optical film comprising:
a transparent substrate;
a transparent microstructure layer on the transparent substrate, the microstructure layer comprising a base portion having a predetermined thickness and in direct contact with a surface of the transparent substrate and a plurality of protrusions protruding from the base portion toward a side away from the transparent substrate; and
a plurality of light blocking layers, wherein each of the plurality of light blocking layers partially covers a corresponding one of the plurality of protrusions, and each of the plurality of light blocking layers comprises one of an absorbing film configured for absorbing light and a reflective film configured for reflecting light;
wherein the image light reflected by the reflection assembly is emitted from the optical film to the windshield for imaging; the transparent cover comprises a first surface and a second surface opposite to the first surface, the first surface faces the accommodating cavity, and the optical film is on one of the first surface and the second surface;
each of the plurality of protrusions extends in a strip shape along a first direction, and the plurality of protrusions are distributed continuously along a second direction intersecting with the first direction; each of the protrusions is a triangular prism, and the triangular prism comprises a first side surface, a second side surface and a third side surface which are connected in sequence; each of the first, the second and the third side surfaces is a quadrilateral; the first side surface is in direct contact with the base portion, the corresponding one of the plurality of light blocking layers covers the second side surface, and the third side surface of the triangular prism is exposed.