Abstract: The embodiment of this present disclosure provides a control method of unmanned aerial vehicle (UAV) hovering in tunnel, which comprises the following steps: acquiring hovering information of hovering position of UAV; acquiring the position information of the current position of the UAV; determining flight parameters based on hovering information and position information. The flight parameters are used to control the UAV to move from the current position to the hovering position.

Abstract: A naked eye 3D display device is provided. The naked eye 3D display device includes a directional projection screen, a laser light source, a red monochromatic laser light source, a green monochromatic laser light source and a blue monochromatic laser light source. Lights emitted by the three monochromatic laser light sources emit incident light on the directional projection screen with nano-grating pixels at specific angles and specific positions, and the same emergent light fields are formed. The laser light source provides multi-perspective image pixels. The multi-perspective image pixels match a nano-grating pixel array on the directional projection screen. By a direct spatial modulation for the laser projection light, colorful 3D display is achieved. There is no crosstalk between various viewpoints. The naked eye 3D display device has no visual fatigue and has a low cost.

Abstract: A multi-view pixel directional backlight module and a naked-eye 3D display device are provided. The multi-view pixel directional backlight module includes at least two rectangular light guide plates closely stacked together. A light-emerging surface of the rectangular light guide plate is provided with multiple pixel arrays. Light emitted by pixels in a same pixel array is pointed to a same viewing angle, and different pixel arrays have different viewing angles. At least one side of each rectangular light guide plate is provided with a light source group. Light emitted by the light source group enters the corresponding light guide plate, then emerges from pixels of respective pixel arrays on the light-emerging surface of the light guide plate, and is totally reflected at positions other than positions of the pixels within the light guide plate. Each of the pixels is a nano-diffraction grating.

Abstract: A naked eye 3D display device is provided. The naked eye 3D display device includes a directional projection screen, a laser light source, a red monochromatic laser light source, a green monochromatic laser light source and a blue monochromatic laser light source. Lights emitted by the three monochromatic laser light sources emit incident light on the directional projection screen with nano-grating pixels at specific angles and specific positions, and the same emergent light fields are formed. The laser light source provides multi-perspective image pixels. The multi-perspective image pixels match a nano-grating pixel array on the directional projection screen. By a direct spatial modulation for the laser projection light, colorful 3D display is achieved. There is no crosstalk between various viewpoints. The naked eye 3D display device has no visual fatigue and has a low cost.

Abstract: A multi-view pixel directional backlight module and a naked-eye 3D display device are provided. The multi-view pixel directional backlight module includes at least two rectangular light guide plates closely stacked together. A light-emerging surface of the rectangular light guide plate is provided with multiple pixel arrays. Light emitted by pixels in a same pixel array is pointed to a same viewing angle, and different pixel arrays have different viewing angles. At least one side of each rectangular light guide plate is provided with a light source group. Light emitted by the light source group enters the corresponding light guide plate, then emerges from pixels of respective pixel arrays on the light-emerging surface of the light guide plate, and is totally reflected at positions other than positions of the pixels within the light guide plate. Each of the pixels is a nano-diffraction grating.