Holographic projection technology (front-projected holographic display) belongs to a kind of 3D technology, which originally refers to the technology of recording and reproducing the real three-dimensional image of an object by using the principle of interference. Then, with the guidance of science fiction movies and commercial propaganda, the concept of holographic projection gradually extended to commercial activities such as stage performances and exhibitions. However, the holography we usually know is often not a holographic projection in the strict sense, but a kind of holographic projection technology that uses methods such as Pepper’s phantom and edge blanking to achieve 3D effects.
The principle of holographic projection technology:
Holographic projection technology (front-projected holographic display), also known as virtual imaging technology, is a technology that records and reproduces real three-dimensional images of objects by using the principles of interference and diffraction.
The first step is to use the principle of interference to record the light wave information of the object, which is the shooting process: the object to be photographed forms a diffuse object beam under laser irradiation; another part of the laser is used as a reference beam to hit the holographic film and superimposed with the object beam. Interference is generated, and the phase and amplitude of each point on the light wave of the object are converted into spatially varying intensities, so that all the information of the light wave of the object is recorded by the contrast and interval between the interference fringes. The negative film recording the interference fringes becomes a hologram, or a hologram, after processing procedures such as developing and fixing.
The second step is to use the diffraction principle to reproduce the light wave information of the object. This is the imaging process: the hologram is like a complex grating. Under the irradiation of coherent laser, the diffracted light waves of a linearly recorded sinusoidal hologram can generally give two one image, namely the original image (also known as the initial image) and the conjugate image. The reproduced image has a strong stereoscopic effect and has a real visual effect. Each part of the hologram records the light information of each point on the object, so in principle, each part of it can reproduce the entire image of the original object, and multiple different images can be recorded on the same negative through multiple exposures. And they can be displayed separately without interfering with each other.
Holographic projection technology features:
1. Holographic technology can record all the information of the amplitude and phase of the light wave of the object, and can reproduce it. Therefore, the application of holography technology can obtain the exact same three-dimensional image as the original (observing the reproduced virtual image of the hologram from different angles, you can see different sides of the object, and there is an inspection effect and a sense of depth of field).
2. Any part of the hologram can reproduce the basic shape of the original object, and the spherical wave scattered at any point on the object can reach every point or part of the holographic dry plate, and interfere with the reference light to form a primitive hologram. That is, each point or part of the hologram records the scattered light from all object points. Therefore, each part of the object hologram can reproduce all the object points irradiated to this point during recording, forming the image of the object, that is, the image of the object can still be reproduced after the part of the hologram is damaged.
3. As a recorder of light wave information, the presence or absence of a hologram is an important criterion for judging whether the 3D technology we are in contact with is a holographic technology.
Use the advantages of holographic projection technology
1. Reproduce stereoscopic images and protect precious cultural heritage
Precious cultural relics or works of art are historical and cultural heritage that cannot be copied. Some of them will be oxidized after being in contact with the air for a long time, which will cause certain damage to the physical characteristics of the works of art. For the past, it is a pity and powerless. , there is no way to save it, but now, with holographic projection technology, artworks can be photographed and imaged, made into three-dimensional images for people to watch, and real cultural relics or artworks can be collected, so that art can be avoided. The destruction of the product does not affect people’s viewing, and it has the best of both worlds.
2. Instead of traditional physical objects, it is convenient and fast
The traditional display method is to place the real objects in the shopping mall window, so that people can make transactions after viewing, but often some objects are too large or for other reasons, and are not suitable for display. With the holographic projection technology, through the holographic display cabinet, No matter the size of the displayed product, the image can be three-dimensionally floating in mid-air. People can not only watch it in 360 degrees, but also interact in real time, without letting go of every detail. Although there is no real object, it is more convenient, faster and safer.
3. Mixing the fake with the real, strong three-dimensionality, more real
Holographic projection technology can show objects or scenes very real and present a three-dimensional situation, so it is widely used in various industries and occasions. Whether it is a banquet hall, KTV, bar, restaurant, exhibition, press conference, etc., the projected scenes or objects seem to be around, right in front of you, both magical and real, making people intoxicated
