The key to the resolution of home projectors lies in the display chip

　　In recent years, with the increasing demand for large-screen movie viewing, home projectors have rapidly become popular and become the first choice of many families. And with the improvement of technology, the projection resolution of the projector is also gradually improving. From 720P to 1080P to the current 4K resolution, the clarity of the picture projected by the projector has also been greatly improved.

　　When purchasing a projector, in addition to paying attention to the real lumen parameters of the product, its real projection resolution is also an important parameter that affects the viewing experience. It's not just about focusing on the "maximum compatible resolution" described on the product detail page.

　　When it comes to the real projection resolution of projection, we have to mention the core technology of projection - display chip technology. The current projector projection technology is mainly divided into two camps: LCD and DLP projection solutions. Then let's take a look at the technology of 3LCD. The three primary colors of light emitted by the bulb are decomposed into three colors: R (red), G (green), and B (blue), and then the image is obtained through the LCD. Because the light source continues to transmit, so the three colors It can be continuously generated, and it can be given shape and action through its respective liquid crystal panels (HTPS method), so that it is much better than DLP projectors in terms of color and brightness, and there is no "DLP" on the projector. "Rainbow Eye" problem.

　　But it is not to say that there are no shortcomings. For example, the resolution of projectors that generally use 3LCD is not particularly high, the mainstream is basically 1080P resolution, and it is also prone to LCD aging problems. At the same time, the aperture ratio of LCD is not high, and black field cannot be done. Enough black, resulting in relatively low contrast. Fortunately, there is dynamic aperture technology to improve dynamic contrast.

　　Since this technology has been firmly grasped by Epson and Sony, it is generally used by Japanese manufacturers. In terms of projection resolution, considering that large-size LCD chips are expensive and the product volume is relatively large, mainstream household products on the market are all At the 1080P level, some high-end products also achieve the so-called 4K resolution standard through "pixel shift technology".

　　Specifically, the original resolution 1920x1080 image scan is projected onto the screen. When the chip is refreshed in a new round, the optical refractor plate oscillates back and forth, and the final image is moved diagonally by half a pixel in each frame. The number of effective pixels has been doubled. In this process, the total pixels generated are (1920*1080)*2=4.15 million, which is half of the native 4K (3840x2160) pixel resolution, and what the eye finally sees is actually a picture that is larger than the original 1080P The image is clearer and sharper.

　　However, products using this technology are often criticized as pseudo-4K. When looking at the picture from a normal viewing angle distance, most consumers will have a hard time distinguishing between a picture produced by a smart projector using a native 4K chip and a picture produced by a projector using 3LCD pixel shift technology.

　　To put it simply, projectors using 3LCD technology have complex internal structures and increase the size of the chip to increase the resolution. They are not dominant in terms of volume and cost, so only Japanese manufacturers like Epson are using them, and in the consumer market. Products less than 10,000 yuan use DLP technology. For example, XGIMI, Nuts and Dangbei, which are very popular in the past two years, are products of HOTUS. Because of its simple structure, relatively low cost, and excellent imaging quality, it is sought after by many manufacturers.

　　DLP is the abbreviation of "Digital Light Processing", which is digital light processing, which means that this technology must first process the image signal digitally, and then project the light. And digital processing will involve an extremely important component, which is also the core technology in the DPL solution, that is, the display chip, and the chip for light reflection processing is DMD (Digital Micromirror Device).

　　Its current main technology provider is Texas Instruments (TI (Texas Instruments). It is no less important than the sensor CMOS on the camera. The DMD is a matrix composed of several tiny mirrors on the semiconductor. Whenever the light is irradiated, the micro mirrors above are controlled by the circuit to quickly flip the angle and then produce different colors, thereby generating images.

　　The size of the DMD directly determines the projected resolution. A DMD is an array of small mirrors with electromechanical structures, and the number of small mirrors directly determines the number of pixels it can control. A larger DMD size can hold more small mirrors, so there is a saying that a larger DMD has a higher resolution.

　　However, it is very difficult to make the small mirror and the attached mechanical structure very small, so a technology similar to 3LCD appeared. This technology is the black technology DLP XPR dithering technology of TI (Texas Instruments). It is to move the chip by half a pixel, project a frame of pictures multiple times, and then use the visual persistence phenomenon to superimpose to achieve a higher resolution.

　　Through the fast switching speed of DMD micromirrors and the use of DLP image processing algorithms, each micromirror can display 4 different pixels on the screen during each frame, and then a full 1920x1080 pixel image can be displayed. The 0.23-inch DMD can reach the 1080P level with only one more projection displacement, which is the high resolution we usually say. Only the 0.47-inch DMD is the native 1080P resolution. Other products like 0.23 and 0.33 achieve higher resolution through "dithering" technology.

　　It is believed that with the continuous advancement of technology, the indicators such as brightness and clarity of projectors will be greatly improved, and there will definitely be more high-quality products in the market. When buying a home projector, in addition to paying attention to the appearance design, you should pay more attention to its technical principles, so as not to be fooled by the merchants, and to choose a product that you are satisfied with.