What is the realization technology of short-focus projector?

The transmittance of a short-focus projector is short, that is, the ratio of the distance between the projector and the screen to the screen size. So what do you know about short-focus projectors? The following is what I have compiled about short-focus projectors. I hope you like it!

What is a short-focus projector?

The transmittance of a short-focus projector is short, that is, the ratio of the distance between the projector and the screen to the screen size. Great progress has been made in the field of projection. A projector can project a picture on a 70-inch or larger screen from a few inches away from the screen surface. Walking in front of the projector, the picture blocking the screen will no longer exist. With the help of ultra-short focus projector, you can watch bright and colorful large-screen images in any room, classroom and conference room.

Short-focus projectors are best at projecting images of about 80- 120 inches at close range, usually around 1- 1.5 meters. However, due to the shortening of the projection distance, the projector does not need to be hung on the teacher's head as in the past, so that the projector light cannot directly reach the speaker's eyes, and the speaker's shadow can be prevented from being transmitted to the screen. In addition, when the short-focus interactive projection is combined with the electronic version, teachers can write and mark on the projection screen conveniently, and at the same time control the computer to realize the interaction with the computer, which makes the classroom teaching more vivid and convenient for students to remember and learn.

The advantages are obvious, but according to the dialectical principle that everything has two sides, the disadvantages of short-focus projection are inevitable. At present, short-focus projection mainly adopts two kinds of technologies, one is direct projection with wide-angle fisheye lens, and the other is reflection. Fisheye lenses were first used in wide-angle cameras. This kind of lens has a protruding front end, which is quite similar to fish's eyes, hence the name. Fisheye lens is a special super wide-angle lens. Although the projection distance is shortened and the picture becomes larger when used on a projector, linear distortion is easy to occur.

Reflective optical technology is adopted, that is, the projector lens projects the image onto the mirror, and then the mirror projects it onto the projection screen. The principle of this projection method seems simple, but it actually requires higher technology. Because the projected image reaches the screen after reflection, the image is easily deformed and the brightness is uneven on the projection screen due to the slight error of the mirror. Therefore, the design and processing technology of optical elements for manufacturing this short-focus projector are quite demanding.

Realization technology of short focal length projector

For short focal length projectors, the concept of "short focal length" is often noticed, but its implementation is still quite difficult. Strictly speaking, the design difficulty of short-focus projectors not only comes from how to achieve a shorter focal length while ensuring the picture quality, but also needs to design a larger off-axis lens while ensuring the picture effect-both of which are challenges to the global optical community.

First, Sanyo and Hitachi's "mirror" short-distance projection technology is inspired by the working principle of rear projection display system. Rear projection display products usually realize a larger projection screen under a shorter light path. It can project a large picture over 100 inch in the shortest distance of one meter. The technical framework of "reflector" not only essentially changes the focal length of the projector lens, but also needs to add a special optical path reflector to realize the transfer of the exit angle of the optical path, thus realizing the two main functional technical characteristics of "short focal length" and "large off-axis". The performance of this kind of products is relatively good, but the structure system is complex and the fuselage is relatively heavy, which is not suitable for portable use.

Second, another short-focus technology camp is mainly Taiwan Province brand, European and American brand and some Japanese brands. These enterprises adopt more complicated lens design to meet the technical requirements of large "off-axis" products except short-focus function. The realization of short-focus part mainly depends on wide-angle lens or fisheye lens technology, and the off-axis part depends on specially designed lens lens. The product quality of "short-focus" projectors using this technology varies greatly, and the main technology is not as high as that of "mirror" short-focus projectors.

Now the two technologies have their own advantages and disadvantages, so it is difficult to distinguish them. And so far, the technical development of short-focus projectors is not fully mature. With the development of the future, the short-focus projection technology will certainly become a higher level, and it is not too late to compete again.

Market Application of Short-focus Projectors

1, Multimedia Teaching: Educational projectors are hot products recently, accounting for more than half of the projector market, and their product lines are also very rich. Short-focus projectors can effectively avoid the problems encountered by traditional projectors, reduce the probability of light being blocked, and make teachers not have to give lectures in dazzling light, thus improving the teaching quality. In the past, the projector used in the education industry had a long hoisting distance, so it was easy for teachers to enter the projected light area when giving lectures. Strong projection light will not only affect students' viewing of projection pictures, but also directly affect teachers' eye health. With the application of short focal length technology, educational short focal length projectors can be installed in small spaces, large classrooms and small classrooms. The ultra-short focal length model has short installation distance, small projection shadow area and more indoor activity area. PJD5350Ls is an excellent short-focus projector for education. It uses the latest short-focus technology to project an 80-inch picture with a projection ratio of 0.6, 1 m, which solves the problem of light and shadow brought to teachers by the long projection distance and improves the efficiency of space utilization. 2. Business meetings: At present, projectors have become the main output equipment for office business in many enterprises, especially the short-focus lens, which is a product with high cost performance, has attracted the attention of customers in many industries. Short-focus lens products, which can achieve 3D projection effect, have become office tools for supervisors and managers because of their high imaging effect, high mobility and good color reproduction function. Commercial projection has also encountered the problem of teaching projection, and there is also a space problem. For some small and medium-sized enterprise users, the meeting room area is generally very small, and there will not be enough space in the classroom, which will affect the installation of projectors. The emergence of short-focus projectors can save more space for small conference rooms, so that meetings can be held at any time.

3. Games: Because projectors have advantages over TVs in screen size, many players prefer to buy a projector to play games, such as Wii games. Due to the distance of conventional projectors, when players appear in front of the screen, they must be careful to avoid the light and try to avoid blocking the game screen, thus reducing the fun of playing games. The emergence of short-focus projectors solved this problem. The game can be operated completely outside the projection distance, no longer blocking the light, no longer limited by the activity space, and the interaction of the game is greatly increased. To some extent, the short-focus projector is undoubtedly the best choice for Wii games.

4. Home theater: Now there are more and more brands in home projector. Low prices and affordable efficiency have become the main reasons why mass consumers choose them. In addition, the entry-level entertainment projector including LED light source technology has also become the first choice for home users. Today's home projector market has become an indispensable product line for the whole projector market, and manufacturers have also seen the huge development potential of the home projector market, so as to increase research and development efforts and better meet the needs of home users. For example, some professional short-focus projectors can project an 80-inch picture with only 2 meters, but they are expensive. As far as the current market situation is concerned, household projectors within 10,000 yuan are the most concerned models. Once, projectors were exclusive to the education industry, enterprises or * * *. Among them, the market share of projectors in the education industry is as high as 50%, while that of home projector is less than 3%. However, in a short period of one year from 2009 to 20 10, the power of projection to enter the home theater has defeated color TV and occupied the peak of the market, especially its unique CMMB function and the function of watching TV directly through the set-top box, with built-in processing and storage. People who recognize the short-focus projector technology also: