Abstract: A head up display device includes a pancake lens and a picture generation unit. The pancake lens includes a half transmittive concave mirror and a reflective polarizer. The half transmittive concave mirror has a light incident surface and a reflective surface. The reflective polarizer is disposed next to the half transmittive concave mirror at the side of the reflective surface for forming a reflective space therebetween. The picture generation unit is disposed in the direction of the pancake lens opposite to the user's eyes. The picture generation unit generates image light and the image light enters the reflective space from the light incident surface. After the reflection, the image light is directed towards the user's eyes to form a virtual image. The optical path of the virtual image and the image light has an off-axis angle.

Abstract: A light-guide optical element is provided, including a transparent light-guide body having a first inclined surface and a second inclined surface disposed therein. The transparent light-guide body includes a side surface facing a first direction, and a first surface and a second surface which are adjacent to the side surface and face each other. The first inclined surface extends from the first surface to the second surface. The second inclined surface is located at the other side of the first inclined surface facing the side surface. The second inclined surface extends from the first surface to the second surface. When an input light enters the transparent light-guide body, the input light is partially reflected by the first inclined surface and the second inclined surface to form an output light output from the transparent light-guide body.

Abstract: A packing box of a portable device is provided, which includes a main plate body and a frame plate body. Plates, which are adjacent to the main plate body and the frame plate body, are respectively disposed with fold-lines; such that a first side plate of the main plate body overlaps a first bonding plate and a third side plate overlaps a second bonding plate to form an accommodating space.: first frame plate, a second frame plate and a third frame plate of the frame plate body are overlapped with one another, so that the first frame plate, the second fame plate and the third frame plate, which are overlapped with one another, separate the accommodating space through a third bounding plate of the frame plate body. When the main plate body and the frame plate body are flattened, the plates are parallel to one another and flat-shaped.