Yesterday, Lei Jun, the head of Xiaomi, also held a Xiaomi product launch conference for the 10th anniversary of Xiaomi when the shipment reached its peak. Xiaomi MIX4, which integrates many black technologies in the field of smart phones, has become the hammer for Xiaomi to go to high-end products!
Let's take a look at the main suppliers that realize these black technology functions.
Spend 500 million yuan to build a full-scale OLED screen: supplier TCL Technology Huaxing Optoelectronics
The original intention of Xiaomi MIX is to build a full-screen mobile phone and accelerate the adaptation and optimization process of Android's panel display technology. From this point of view, Xiaomi has contributed to the industry in the technological progress of smart phones.
Compared with the previous principle that Xiaomi stretched the panel size as much as possible, the design of the panel decorative frame was changed, so that the panel display area occupied the front glass protective cover area of the mobile phone as much as possible. Xiaomi also made a big fuss from the beginning, killing the component area on the forehead of the mobile phone.
Then it is the easiest way to remove the distance sensor, light sensor, front camera, earpiece, etc. Xiaomi tried the screen sound technology before removing the earpiece, but with the introduction of earpiece stereo technology and virtual environment sound technology by Apple, the earpiece function can be directly replaced by the virtual channel on the speaker, and the sound is directly emitted from the sound hole of the frame, without the need to reserve the earpiece position on the front panel.
As for the distance sensor and illumination sensor, as long as the organic light-emitting diode display screen is used, all functions can be debugged directly under the display screen, because the light transmittance of the screen itself is above 40%.
The hardest thing is to hide the front camera.
Previously, the industry tried to customize small-size cameras as soon as possible. However, with the increasing demand for the front camera in the fields of video self-timer and live video broadcast, the function of the front camera with high pixel and large size sensor has also become just needed by smart phones, so reducing the camera size will soon lose the market.
Later, in order to solve this problem, the smart phone brand introduced a similar external drive camera scheme, including a lift camera, so that the camera can be moved from the inside or back of the phone to the front for shooting when necessary, and then hidden in the fuselage again after shooting.
The advantage of this method is that the design of the front display panel is completely free, and there is no need to consider the layout of the camera. Another advantage is that the professional photography technology of the rear main camera can be applied to the front camera, which can become a real live productivity tool.
However, the disadvantage of this method is also obvious, that is, the mechanical transmission part of the front camera occupies a lot of space in the body of the smart phone, which sacrifices the heaviest portable performance of the smart phone for the design of the smart phone that has been mainly integrated, and brings the risk of cost and reliability.
But in any case, the external front camera will be an important development branch of the future mobile phone, because the promotion of the front image is the most direct and best solution.
In addition to these schemes, there are other ways to make the display border of the mobile phone closest to the border of the mobile phone. First, make the display flexible, and bend the border of the display into a border area. Second, dig a hole in the middle of the display screen, and move the light entrance window of the front camera into the display area without affecting the design of the display screen frame. Thirdly, the camera is placed under the translucent OLED panel, and the "window screening" effect of the OLED display screen is removed by algorithm.
In fact, the hole-digging screen continues some shortcomings of the customized front camera, so the size and number of holes are still one of the factors that affect the user experience.
Putting the camera under the screen has actually been realized in optical fingerprint identification, because optical fingerprint identification can be completed only by grabbing hundreds of feature points on a sensor with a large imaging area. The pixel area of this sensor has a resolution of millions to tens of millions of pixels compared with the front camera, and it is also necessary to realize the true reproduction of color wavelength. Therefore, how to remove the "screen filter" effect of organic light-emitting diodes and improve the photosensitive ability of camera sensors has become the most difficult place in the industry.
Due to the limitation of semiconductor materials and chip design, the technology of camera sensor is now the technical bottleneck of the industry, and it is very difficult to upgrade, so the main direction of the industry is how to improve the "screen filter" of OLED display screen! This is based on the technical support provided by OLED panel factory.
Xiaomi MIX may have despised the head-mounted organic light-emitting diode display earlier. According to Li Xing's understanding, although Xiaomi mobilized more than 100 engineers and allocated 1 100 million yuan to tackle key problems, the final result, with the cooperation of TCL technology Huaxing Optoelectronics, was iterated for three times to get the present effect. Xiaomi named the first mass-produced organic light-emitting diode display screen supporting the off-screen camera technology as CUP full screen-under-panel camera.
After three iterations, Xiaomi adopted more than 60 patented technologies, including high transmittance screen design, high resolution screen design, bottom display algorithm design, and off-screen active algorithm design. These technologies involve a series of complex tasks, such as pixel area reduction and layout design of organic light-emitting diodes, transparency of driving circuits, optical film design of organic light-emitting diodes' optical structure materials, optical path correction algorithm, optical wavelength compensation design, camera pixel interpolation optimization, pixel replication and fusion algorithm optimization and so on. According to the information that Li Xing learned from the industry, each debugging may be a major adjustment of the tooling and production technology of the OLED panel production line, and it is the transfer cost of the trial production cost of the panel factory.
They spend so much energy in a small camera area, so it is normal for Xiaomi Cup to adopt other top-level organic light-emitting diode display technologies which are the most mature in the industry. 2400* 1080 full screen, high pixel per inch of 400PPI, high refresh rate of 120Hz, high touch rate of 480Hz, and Corning glass-ceramics cover. These are all high-tech technologies in the industry. Of course, there is a mature ultra-thin fingerprint identification technology under the screen of organic light-emitting diodes.
The off-screen camera technology is only realized and can be used, which is far from the level of real cameras and needs the efforts of the industry. Xiaomi also said in the official website that the full screen of Xiaomi Cup will hinder the self-portrait light to some extent, and the post-processing algorithm needs to be revised and optimized, so the image quality of self-portrait imaging and preview will be different, and the actual effect will be different due to specific shooting conditions.
Brand-new ceramic backboard and metal middle frame: supplier BYD
Ceramic backplane technology is also a traditional feature of Xiaomi MIX, but the previous ceramic backplane is also a shortcoming of Xiaomi MIX user experience, because it is too heavy and fragile. If you bring a cover to match the ceramic backboard, it is still different from the plastic shell.
Therefore, Xiaomi MIX continued to upgrade the ceramic backplane technology this time. According to what Li Xing learned, this time Xiaomi chose BYD, which has a strong OEM business in mobile phone structural parts.
The back of Xiaomi MIX 4 adopts integrated precision ceramics and lightweight ceramic technology, which reduces the weight by 30%. There are three color schemes: ceramic white, ceramic black and shadow blue gray. The weight of the whole machine is 225g, and the thickness is only 8.02 mm BYD Electronics is the main supplier of Xiaomi MIX 4 lightweight integrated precision ceramic backplane, and also the exclusive supplier of small metal A shell (metal front shell)!
The backboard of Xiaomi MIX 4 adopts a more complicated precision ceramic integrated molding process. After half a year's exploration and improvement, BYD's electronic technology team, with its powerful precision machining ability, challenged unprecedented technology with science and technology to create a seamless fuselage with nobler texture and rounder color. BYD has long participated in Xiaomi MIX 2S, MIX 3, 1 1 Ultra and other ceramic mobile phone products in ceramic backplane technology, and both parties have jointly established a joint laboratory, so the success of this technical iteration is also the accumulation of BYD's technology for many years.
Xiaomi's previous suppliers of ceramic backboards were Sanhuan and Lance. Because ceramic processing technology is a standard technology, it will be copied on a large scale as long as it is successfully developed, but the investment ratio of copying capacity is large, so orders are generally allocated through capacity matching in the supply chain.
According to Lei Jun's introduction at the press conference, the nano-zirconia ceramics used in Xiaomi MIX 4 have been calcined at 1300 degrees for three times, with an error of plus or minus 5 degrees, achieving a technical breakthrough that is 30% lighter than traditional ceramics, effectively solving the shortcomings of high density and heavier weight of integrated ceramics in the past. Achieve the perfect balance between "extreme stacking" and grip.
In order to realize the integrated effect of Xiaomi MIX 4, BYD Electronics also developed and applied the small metal A shell (metal front shell) for the first time, which optimized the antenna performance and perfectly concealed the antenna spacer. The ultra-thin metal surface of the eight-antenna partition slot is easy to deform and crack, which poses a great challenge to the flatness. In order to improve the flatness, BYD's electronic technical team verified more than 20 schemes, constantly overcome difficulties, improve the yield, and then select a high-precision and stable engraving machine to carve the appearance, reduce the die and polish, and finally present the beauty of delicate, bright and exquisite details!
Homogeneous hot plate reduces weight and squeezes graphene radiator: supplier Murray technology
Apple brought graphene radiator into electronic products for the first time. Its biggest feature is that the smallest heat capacity volume can achieve the fastest thermal management effect, and it can be applied flexibly in a large area. The construction is simple, the soaking area can be expanded to the maximum area, and the heat can be quickly brought to the non-heat affected area, thus realizing the protection of the heat-sensitive element.
However, due to the limitation of molecular structure design and processing level of raw materials, the quality of products produced by graphene is almost a thousand miles away. Even if the quality control is not good, graphene has become a heat collector in the thermal management system, which will destroy the thermal management system of the product. It was once called "pseudo-technology" by the industry.
This time, Xiaomi re-used graphene to replace the safer metal VC vapor chamber in the industry, mainly because Xiaomi invested in an upstream supply chain enterprise, Murray Technology, through an industrial fund.
Xiaomi introduced the graphene "freezing" cooling system by using the graphene sintering technology of Murray technology. For the first time in the industry, a 3D graphene vapor chamber with a thickness of 280 microns and an area of 1232 mm2 was introduced, covering the core heating area of the motherboard. The total heat dissipation area is as high as 1 1588 mm2, which greatly improves the heat dissipation efficiency. The heat dissipation performance of this 3D graphene vapor chamber is equivalent to that of VC vapor chamber, and its weight is only half of that of VC vapor chamber. It has the advantages of good flexibility, strong processability and lower cost than VC steam chamber.
Periscope camera and free-form lens: supplier Yu Shun Optical Technology Company.
The technical breakthrough of MIX 4 in image is limited to the front shooting under the screen, and the rear three-camera module is not simple in materials. There is a10.00 billion pixel11.33 inch outsole main camera, an 8 megapixel periscope with 5 times telephoto lens, and dual optical image stabilization for the main camera and telephoto lens. According to Li Xing, MIX 4 is also equipped with 120-degree and130,000-pixel super wide-angle auxiliary cameras for the first time, using free-form surface lenses.
First of all, in terms of "telescopic" ability, MIX 4 has a maximum zoom shooting ability of 50 times. The focal length before 5 times zoom should be taken care of by the optical anti-shake main camera with 65.438+0 billion pixels, and after 5 times zoom, it should be handed over to the periscope anti-shake telephoto auxiliary camera for "relay". At the same time, thanks to the optical anti-shake mechanism and Snapdragon 888+, you can easily shoot by hand from a distance, without worrying about jitter and blur, and really rely on professional cameras.
This time, Yu Shun Optical Technology not only brought mature periscope camera lens technology and module processing technology to Xiaomi MIX4, but also brought wide-angle free-form lens technology to Xiaomi MIX4. Compared with ordinary ultra-wide-angle lens, the biggest advantage of Yu Shun Optical Technology's free-form lens is its strong anti-distortion effect. The imaging effect greatly reduces the distortion rate of ordinary lens from 20% to about 1%, so that it is almost imperceptible to the naked eye.
Lens distortion is a kind of aberration, which has no effect on picture clarity. Only distorted objects affect perception and lose authenticity. In the era of traditional photography, the main method to eliminate distortion is to use PS and other retouching tools to correct distortion. This can often achieve good results. However, in the era of mobile phone photography, people prefer to simplify the procedures of photography and reduce the complexity of later retouching. So mobile phone manufacturers began to study the algorithm to eliminate distortion, trying to correct distortion automatically when shooting.
Free-form lens is a proper black technology in mobile phone lens, and the lens surface is a unique irregular free structure. It can correct the uneven light projected by the edge, let the external light hit the sensor vertically, and fundamentally solve the distortion problem of super wide angle (figure 1 ordinary lens, figure 2 free-form lens,). The requirements for precision, materials and processing technology are extremely high. Hair is difficult to be processed to the accuracy of1100, so the cost is very high.
Free-form lens suppresses distortion by optical hardware, which is more stable than software algorithm in theory. Especially when shooting video, it is difficult for the algorithm to correct the distortion in real time, and then the hardware advantage of free-form lens appears.
More importantly, the lightweight feature of freeform lens brings more space for the design of mobile phone camera module. By introducing free-form surfaces, the optical system can be made more compact in structure, lighter in weight and fewer in optical elements. Therefore, in the case of similar volume, the application of freeform surface can make the space utilization of camera module higher, which is undoubtedly a proper gospel for the design of highly integrated smart phones.
In fact, free-form lenses are not only used in the glasses industry, but also in medical treatment, projection, printing and scanning and other optical related fields. Optical lighting is more widely used, and free-form surface design can significantly enhance the uniformity of lighting.
As can be seen from the above description, freeform lens has a good effect on reducing aberration, that is, weakening distortion. For mobile phone manufacturers suffering from ultra-wide-angle distortion, it is undoubtedly a design worthy of reference.
However, due to the limited volume of mobile phone camera module and the complex stacking of internal components, high requirements are put forward for the design and processing technology of free-form lens.
However, the free-form lens has low processing yield, complex technology and expensive equipment, so the cost is relatively high. At present, there are few mobile phones equipped with free-form lens, and only the ultra-wide angle with the most serious distortion problem is worthy.
If Yu Shun Optical Science and Technology continues to make efforts in this respect and reduce the cost of free-form lens, then free-form lens technology may be applied to both main lens and telephoto lens. While suppressing distortion, there is more room for stacking optical systems.
Finally, Xiaomi MIX4 has been blessed in the security of virtual SIM card mobile phones and the increase of near-field communication UWB applications. Liquid storage technology is also developed in the system memory processing mechanism, which eliminates fragmentation and ultra-fast charging, making this mobile phone close to the experience of high-end users.
Products are becoming more and more "stupid", which no longer reflects "users toss about a fever", but an upgrade of "users have no feeling to experience a fever". MIX4 has officially become the hammer for Xiaomi to move towards high-end smart phones!