The new trend of the touch screen industry Ultrasonic touch to create a new experience of human-computer interaction

Nokia 7710 phone

As early as the era when the smartphone market still belonged to Nokia, the touch screen of mobile phones was still using resistive screen technology. Just in November 2004, Nokia launched a mobile phone with touch, the Nokia 7710, whose screen is equipped with resistive screen technology; the Nokia 5800 XpressMusic released in 2008 is also equipped with this technology, which is also the first S60 platform to use touch technology.

Nokia 5800 XpressMusic

It is the advent of the Nokia 5800 that let the majority of consumers know the concept of "resistive screen". As soon as the mobile phone was launched, it was sought after by countless consumers, and "instant" became an "arcade machine". The nokia 5230, released in 2009, carried this honor forward, with sales of 150 million units that year.

On January 9, 2007, on the other side of the ocean, at the Marscony Convention Center in San Francisco, usa, the Apple Global Developer Conference was being held, and Jobs was on the stage to show off the new revolutionary product, the iPhone. As the phone screen slid smoothly at Jobs's fingertips, the audience screamed as they cheered for Jobs and the iPhone.

This iPhone uses a different touch solution from Nokia - capacitive touch technology. The key to this technology is to form an electrode structure on both sides of the glass substrate, Apple through the taiwanese touch screen manufacturer Chenhong after countless days and nights of research, finally developed a capacitive screen that meets the requirements. Without Chenhong's "transparent glass projected capacitor technology", the epoch-making product of the iPhone is likely to be difficult to produce. It is also the landing of this "capacitive screen" technology that has made the iPhone in Jobs's hand change the world and bring a better touch experience.

After years of development, today's smartphone products have been equipped with capacitive touch screen technology. Today's smartphones not only have a better touch experience, but also have great improvements in screen refresh rate, power consumption, display color, etc. It can be said that touch has changed the way people interact with mobile phones in the past 30 years, bringing us a more convenient operation experience and making interaction more direct.

Seeing this, there will certainly be many people who will wonder why resistive screen technology has disappeared on smartphone devices? This involves obstacles that are difficult to cross with touchscreen technology——— light transmittance.

Resistive touch screen technology

Because the resistance screen is a sensor, its structure is PET film plus glass, between the PET film and the glass coated WITH ITO (indium tin oxide) coating, ITO has good conductivity, when the PET film is touched it will bend downwards, at this time the following ITO coating can contact each other and connect the circuit at this point, and then through the sensor to transmit the corresponding electrical signal, after the conversion circuit sent to the processor, through the calculation can be converted to X, Y value on the screen, so as to complete the click selection action.

As we all know, glass is the material with the best light transmittance, but because the resistance screen needs to have physical deformation, the outer PET film cannot be made into tempered glass or other hard materials. Therefore, both durability and light transmittance will have a large light loss, plus the reason for the multi-layer structure, but also exacerbate the characteristics of light loss. Also because of structural reasons, the screen structure is too much and too complex, which is not conducive to making a thin and light fuselage, and it is not in line with the development direction of smart phones.

In addition, the resistance screen requires greater effort to achieve touch in the operation mode, and it is not ideal in the operation mode; at the same time, because of technical problems, it is impossible to achieve higher resolution. For a variety of reasons, the resistance screen has faded out of the field of personal consumer electronics.

Of course, the resistance screen is still favored in the industrial field because of its strong anti-interference and easy to touch. For example, in industrial scenarios, the environment is relatively harsh, it is easy to drift and cannot be operated with gloves. The resistive screen is more suitable for this complex industrial scene, can be operated with gloves, can use any object to touch, and has stronger immunity to electromagnetic interference.

With the rapid development of the Internet, mobile phones are not only used as mobile communication tools, in the past those phone calls, text messages and other ways are now replaced by browsing the web, viewing pictures, watching videos and other content, which puts forward high requirements for the visual effect of the display, of which screen brightness is a very important indicator. Because glass has a high transmittance, the current smart phone product display outer screen is made of glass. In contrast, the capacitive screen is not only very mature in technology, but also the structure is relatively simple, and it is easier to do the guarantee function than the resistance screen, which can not only support better multi-touch technology, especially the display effect is much better than the resistance screen, which can meet the diverse interaction needs.

iPhone 6s phone

Nowadays, touch screen technology is also slowly developing, in addition to resistive and capacitive touch screens, there is now a new touch screen technology, that is, pressure-sensitive touch screens. For example, apple's iPhone 6s phone released in September 2015 has screen pressure sensing technology, which is officially called "3D Touch". By adding a layer of pressure sensor under the display module, when the finger is pressed, the screen display module becomes different in the slight shape, to perceive the size of the force, so as to achieve the new function of three-dimensional touch. However, in the end, due to the "weak perception" of the function, cost, software adaptation and other reasons, this function was eventually canceled.

Ultrasonic touch solutions open a new era of intelligent interaction

In recent years, the touch control industry has flourished, more and more manufacturers have entered this market, technology is also constantly evolving and improving, new technologies are constantly replacing old technologies, and human beings are constantly exploring touch technology. Recently, the pioneer in the field of software-defined intelligent interaction, "Xiantong Technology", launched an ultrasonic touch solution that can achieve virtual control on large displays and wearable devices, bringing innovation and change to the user experience and user interface of consumer products.

The technology enables designers to interact with touch and pressure even on the tiniest surfaces, while unlocking entirely new user experiences and capabilities for wearables without fear of the complexities of the outdoor environment and waterproof interactivity. The two touch solutions released are suitable for small wearables and large smart displays, from headphones, smart watches, smart glasses, etc., to smart displays as large as 15-24 inches.

As more and more devices adopt touch interaction methods, the use of scenarios has become complex and diverse, the existing capacitive touch scheme use of the scene limitations are more prominent, limited to interaction on the glass screen, can not be applied to metal, plastic and other materials, touch method is difficult to expand to the screen outside the place.

Ultrasonic sensing principle of Xiantong Company

The biggest advantage of ultrasonic touch technology over traditional capacitive touch technology is that it does not rely on the material itself, not only on the screen, but also in metal, wood or plastic and other materials can be realized. By transmitting the ultrasonic signal to the corresponding object, as long as the finger touches its coverage, the ultrasonic wave can be rebounded, and after the receiver receives the signal, it can accurately locate the finger position and judge the finger pressure colonel, so the ultrasonic touch technology is actually not limited by the material.

At the online conference held in December 2021, Xiantong Technology launched an ultrasonic touch solution that can achieve virtual control on large displays and wearable devices - SDSWave Solution Suite. The wearable solutions released include an ultra-low-power and high-precision SNT8255 processor, and a gesture recognition engine that can accurately identify forces and gestures to initiate applications and built-in functions in the virtual control operation device.

Lenovo Savior Esports Phone 2 Pro

The ultrasonic touch solution has been supported by many mobile phone giants around the world, and the application of this solution can be seen in many flagship smartphone products. For example, in the first half of 2021, the cooperation between Xiantong Technology and Lenovo Savior, using four ultrasonic shoulder buttons, allows lenovo Savior Esports Mobile Phone 2 Pro to obtain a similar gamepad operation feeling, even if there is no physical button, it can seamlessly achieve game operations such as aiming, shooting, and opening the camera.

Image source Prospective Economist

Ultrasonic touch solutions are still a relatively new technology, which also means that it has a huge market space, and the future of ultrasonic technology is bound to be the trend of the times. According to IDC data, shipments of wearable devices in mainland China have risen steadily from 2015 to 2020, reaching 107 million units in 2020, and the demand for wearable devices has continued to expand. In the second quarter of 2021, the proportion of watches and bracelets in the mainland wearable devices reached 26.8% and 17.8%, respectively, and the proportion of ear-worn devices reached 55.4%. According to IDC forecast, the global market shipments of smart watches and bracelets in 2021-2024 will reach 14.3% and 2.4% respectively, and the Chinese market will also grow synchronously, bringing a lot of demand to the touch screen industry. In addition, smart devices such as PCs, displays, and tablets are still an incremental market, and the scale is huge, and ultrasonic touch technology has a lot of room for expansion.

Write at the end

In today's diversified devices, whether it is a small wearable device or a large display product, touch seems to have become the most intuitive and natural way to interact. Therefore, the various technological innovations derived around these devices are self-evident in the improvement of user experience. Touch screen technology has undergone great changes from the past to now, from resistive screens to capacitive screens to ultrasonic touch screens, touch screen technology continues to innovate, the emergence of ultrasonic touch technology will further stimulate the development of the field of touch. In the future, ultrasonic touch technology will bring more possibilities to users.