Capacitive touch is the mainstream, piezoelectric touch is favored

According to DisplaySearch's forecast analysis, the global output value of touch products was approximately US$4.3 billion in 2009, and will reach US$14 billion in 2016. In other words, the future compound annual growth rate of touch products will exceed 18%. Currently, among all electronic related fields, except for touch, no other industry can have such a high annual compound growth rate in the next few years, which is a very important reason why we believe that touch can be successful.

Two Milestone Events in the Touch Market

In the past decade, two very important events have occurred in the touch field. The first event is the launch of the iPhone . Multi-touch and zooming in and out under multi-touch are not invented by Apple. However, the iPhone and iPad launched by Apple in recent years have been very successful, indicating that this product actually has a meaning in the market.

Analyzing the functions of the iPad, we can clearly find that in addition to the application of multi-touch on the 9.7-inch screen, the other technologies it uses are very mature parts of existing technologies. This means that people are willing to experience the feeling of multi-touch regardless of medium or large size. The success of the iPhone and iPad has made an indelible contribution to promoting multi-touch technology and making it more popular and universal in the field of human life. The

second major event in the touch field is the support of multi-touch by Microsoft's Windows. Microsoft's technology solves the multi-touch problem at the operating system level, thereby solving the patent problem of multi-touch, which further encourages other system manufacturers to start supporting multi-touch systems on their respective operating system platforms, which is of great significance.

One concept that needs to be clarified is that Windows 7 can support unlimited points. The so-called ten-point touch and four-point touch now are all due to the limited technology of the control chip manufacturers. There is no limit to the number of points supported by Windows 7.

Capacitive touch is the mainstream

. Since touch is an indirect measurement technology, there are about 100 types of touch. For example, capacitive touch determines the location of a point through the process of current change; ultrasonic wave determines the position and direction by where the shadow falls during the ultrasonic wave emission; and optical touch knows the location of a point through image processing. It can be clearly seen that they are all indirect measurement technologies, and any indirect measurement technology can be made into a touch technology through some algorithms . This is one of the main reasons why there are so many touch technologies.

Through induction and arrangement, we can divide touch technology into 11 categories, of which 4 categories can support so-called multi-touch, including capacitive, piezoelectric, etc. Basically, they all support multi-touch mode, and it is unlimited.

There is no perfect touch technology in the world at present. Each technology is imperfect, has its own shortcomings, and has limitations in use. For example, the capacitive touch widely used by Apple cannot be used when wearing gloves, and is very afraid of water. For example, optical touch works well on large sizes, but cannot be used on small sizes. Moreover, the optical type decays very quickly. It is very sensitive at the beginning, but the sensitivity becomes worse as time goes by.

At present, the main patents of touch technology have expired. Capacitive, infrared, and ultrasonic, these main touch technologies have been invented for more than 20 to 30 years. It is precisely because of this that more newcomers can be attracted to participate in research, and then new patents can be proposed, making the types of touch technology more and more.

The most popular touch technology on the market is projected capacitive technology, which can measure the change of current through fingers, and detect the position of points through the change of charge. The biggest advantage of projected capacitive is that it can achieve real touch, and its biggest problem is that it can only be used with fingertips, not nails. Due to Apple, the current mainstream position of this technology is unquestionable. Piezoelectric multi-touch has a promising future

Among many touch technologies, Ruiyang Optoelectronics chose piezoelectric multi-touch technology for four main reasons. First, it is an infinite multi-touch technology that fully supports Windows 7 and Android . Second, this technology has very high precision and small error. Third, piezoelectric technology can effectively detect the area. Fourth, this technology has no fundamental restrictions and can be used even with gloves.

In fact, this technology combines the technical characteristics of capacitance and resistance and has been commercialized before 2005. Capacitive touch is most afraid of TFT and RF interference problems, but piezoelectric does not have this problem. It has very high anti -EMI and ESD capabilities and very light input. In addition to capacitive touch, piezoelectric multi-touch technology also has the advantages of resistive touch. It can detect both finger pulp and fingertip.

The difference between piezoelectric touch and projected capacitance is actually not that big. First of all, their glass structures are exactly the same, both using matrix structure. The biggest difference is that the capacitive type uses current, while the piezoelectric type uses voltage to act on the coordinate changes to determine the position of the point.

Of course, piezoelectric multi-touch technology also has its own shortcomings. It has many process lines and very high requirements for manufacturing technology. Even if commercial products are launched, not many can be mass-produced. Among all domestic manufacturers, Ruiyang Optoelectronics is currently the only company that can produce and develop this technology. Not long ago, Ruiyang Optoelectronics' piezoelectric multi-touch solution has passed the Microsoft Windows 7 multi-touch (ten-finger) certification test , becoming the first touch module manufacturer in China to pass this certification.