The optical technology design and manufacturing technology of virtual reality stereo helmet are becoming more and more perfect. It is not only a personal application display, but also the basis for the design of compact large screen projection system. The image of small LCD display devices can be made into a full image large screen through the optical system. In addition to being widely used in modern advanced military electronic technology and becoming the necessary equipment of individual combat system, it is also extended to civil electronic technology. Virtual reality electronic technology system first applies virtual reality stereo helmet.

Whether it is required to see the required data in the field of view of the real world at the same time, or to experience the telepresence of wholeheartedly investing in the change of visual images, simulation training, 3D games, telemedicine and surgery, or to expand the visual ability of human eyes by using infrared, microscope and electron microscope, virtual reality stereo helmets have been applied. For example, in military affairs, virtual reality stereo helmets can be used for command transmission, battlefield observation, terrain viewing, night vision system display, gun aiming system of vehicles and aircraft, etc. In CAD / CAM operation, HMD enables operators to view data remotely, such as local data list, engineering drawings, product specifications, etc. When Boeing uses VR technology to design Boeing 777 aircraft, virtual reality stereo helmet has been applied.

How to use the virtual reality helmet
The virtual reality helmet cannot be used alone, or it will affect the use effect. It must be combined with the following equipment to ensure its use effect.
1. Cooperate with 3D virtual reality real scene
2. Cooperate with large screen stereo reality screen
3. Use with data feedback gloves

Research and development history of virtual reality helmet
Oculus VR was founded in 2012 to develop virtual reality helmets. In just two years, it was acquired by Facebook for $2 billion. The virtual reality head display rift launched by oculus is known to be consumer oriented and priced at hundreds of dollars. VR Box Virtual Reality Headset.

Virtual reality
Google officially launched an affordable cardboard + mobile phone solution in 2014. Microsoft demonstrated the "hybrid reality" Microsoft holographic head display integrating virtual reality and augmented reality at the exhibition in 2014, showing its great potential in the field of entertainment and office.

Samsung launched the first generation of virtual reality head display device gear in September 2014, and then announced that the second generation of gear virtual reality head display produced in cooperation with okuras will start sales.VR Box 3D glasses

On September 14, 2015, guided and supported by the Information Office of the State Council, the National Tourism Administration and the Chinese Consulate General in New York, and hosted by the five continents communication center, the "beautiful China experience day" was successfully held in the United States for the first time. Virtual tourism has become a "new window" for China to show the world rich tourism resources and long Chinese culture. It has applied virtual reality technology to show the strength of Chinese virtual reality enterprises to the world. After wearing the 3glasses virtual reality helmet, the participants of the "beautiful China" experience day expressed incredible for the immersive experience of this virtual tourism. The breakthrough attempt in the field of new media communication can enable more people to feel the beautiful scenery of China through game experience, approach China, discover China, and then feel and know China. China's original VR power represented by 3glasses is leading China's virtual reality to the world.

Working principle of virtual reality helmet
The principle of virtual reality stereo helmet is to enlarge the image generated by small two-dimensional display through optical system. Specifically, the light emitted by the small display passes through the convex lens, making the image similar to the distant effect due to refraction. Using this effect, the near object is magnified to the distance for viewing, so as to achieve the so-called hologram vision. The image of liquid crystal display (small cathode ray tube was used in the early stage, and organic electroluminescent display devices have been used recently) is transformed into a large screen image through an eccentric free-form surface lens. Because the eccentric free-form surface lens is an inclined concave lens, it is not only a lens function in optics, but has basically become a free-form prism. When the generated image enters the edge mirror of eccentric free-form surface, it is fully reflected to the concave mirror opposite to the viewer's eye. The side concave mirror is coated with a layer of mirror coating, and the reflected light is amplified and reflected to the eccentric free-form surface edge mirror again, and the inclination of the light is corrected on this surface to reach the viewer's eyes.