1. The origin of three-dimensional printing
From 1838, the British physicists invented the stereoscope. In 1882, the Frenchman Niepor shot the first stereoscopic image according to the “permanent vision†theory. After more than 100 years, a large number of scientists continuously The pursuit and exploration finally enabled the stereoscopic image arts to follow the two generations of black and white and color, and then entered the era of stereography in the 1990s. Leave everything in an instant, round the human dream for a hundred years, reproduce the three-dimensional world on a two-dimensional plane, and make the stereoscopic experience of human vision enter a new field. All things in the world are three-dimensional and three-dimensional. Any object in space has a three-dimensional shape of length, width, and height. That is to say, objects have a front-rear, left-right, and top-to-bottom relationship with each Other. However, when they are reflected on photographs and general prints, they can only show up and down, left and right. The two-dimensional relationship loses its three-dimensionality. In order to emphasize the three-dimensionality of the objective world, people have developed a new printing field - three-dimensional printing. Three-dimensional printing is to simulate the distance between two eyes of a person and shoot from different angles; the left and right pixels are recorded on the photosensitive material, the right pixel is viewed by the left eye, and the left pixel is viewed by the right eye. According to this principle, the printing process technology for producing printed matter is called three-dimensional printing. Therefore, we can say this: Three-dimensional printing is the use of left and right eye parallax covering the grating column panel to obtain a three-dimensional image printing.
2. The basic principle of three-dimensional printing
Three-dimensional printing is to use a two-lens stereoscopic camera equivalent to the human eye to shoot two negatives, stereoscopically photographing them, and printing them into plates equivalent to the images seen by the left and right eyes respectively. Then stagger printing at a certain angle. In order to see the image, a thin, concave-convex, transparent plastic sheet, referred to as a lenticular lens, must be added to the printed matter. This lenticular lens is quite critical, with an irregularity of 0.6 mm. Convex surfaces divide the image equally into a myriad of pixels, with 120 lines per inch of bump, with 6 pixels under each line. These pixels respectively form a stack image that is shifted by a certain distance in the plane. This staggered distance, with the help of a cylindrical lens, forms a space, allowing people to feel the depth between the front of the scene and the background, so that the image information acquires a three-dimensional effect.
3. Prerequisites for three-dimensional printing
Stereo photography is a prerequisite for three-dimensional printing. Stereoscopic photography methods are roughly divided into direct and indirect methods. The direct method refers to the method of photographing directly through the transparent column lens. Moving the lens within a certain field of view continuously photographs the object and has a good effect. The indirect rule is to take more than two photographs at a pre-determined location and then combine them correctly in a gap. Considering the form of the printing plate, the effect of printing out with the Jura version is the best, because it does not interfere with the dot, but due to the limited print volume, offset printing is generally used at present.
First use a 300-line/inch screen to create a positive-tone color separation sheet. With the positive color separation sheet, print the four-color separation sheet into a virtual image when printing. In order to misplace the printing plate, the misalignment of the four color separation films must not exceed the outlet of 0.6mm.
When transparent lenses are attached to the printed prints, the thickness of the cylindrical lenses must be limited in addition to the 0.6mm gap between the transparent lenses. Convex shape, too thick and lossy three-dimensional, generally 0.2-0.3mm is appropriate.
4. Overview of three-dimensional printing technology
There are many kinds of three-dimensional printing, and the general three-dimensional printing process mainly includes the following steps:
The principle of various three-dimensional printing processes is basically not very different, but only in the individual process details to improve, but the current three-dimensional printing technology can be divided into the following categories according to the observation method:
Two-color three-dimensional printing with complementary two-color printing, with two-color glasses can see the three-dimensional effect.
Ordinary three-dimensional printing, after the film processed by stereo photography, through the cylindrical grating method, according to the refraction of light to see the stereo image.
In holographic stereo printing, the laser holographic stereo photography film is processed and molded, and the color and image are seen through the interference of light.
In the laser hologram printing technology, when a photograph is taken, the laser is diffused onto the subject by a convex mirror, and the light reflected from the subject reaches the surface of the film. Another column of light, which is not related to the subject, is the reference light that is reflected by the mirror and reaches the surface of the film. The overlapping of the two lasers produces a thin line called an interference line. Films with such fine lines are called holograms. Irradiating the hologram with laser light enables the image in the line to be reproduced. Hologram production and reproduction, collectively referred to as holographic or holographic.
Three-dimensional printing, printed by computer-processed three-dimensional manuscripts, can see stereoscopic effects through gaze.
Embossing and embossing are performed on the surface of the printed paper or plastic to produce a three-dimensional effect for direct viewing.