Help the mobile phone realize the fingerprint recognition under the screen, Apple's new patent exposure

Recently, Apple has acquired a patent for ultrasonic pressure and touch sensors, which can be used to produce thinner and more integrated 3D Touch devices. It has been reported that this structure is the obstacle that Apple does not incorporate the fingerprint technology of the screen in iPhone X. U.S. Patent and Trademark Office, issued to Apple Patent No. 9,772,721, describes in detail a method for detecting input pressure by transmitting and detecting ultrasonic pulses. Specifically, the system measures the interaction between the above pulses and the user's fingers. For example, when deploying an ultrasonic sensor, the ultrasonic components can be arranged in a row or a row, or a series of independent sensors can be arranged in any predetermined configuration to generate and receive ultrasonic waves. The first set of ultrasound waves is transmitted to a screen area that the user's finger may touch, or an interactive surface. Ultrasound or pulses first pass through components such as the sensing surface or the input surface and are then reflected by a portion of the user's finger or other object in contact with the substrate. The reflected pulse can be used to determine the distance between the input object and the sensor and then used to calculate the pressure. It is also possible to use the attenuation (or the number of pulse signals absorbed by the contact object) to determine the magnitude of the pressure. For example, when a finger presses the screen hard, the surface will increase, thus absorbing a larger proportion of pulses. This data can be used to improve the accuracy of the input pressure calculation. Apple's patent states that this pressure sensor array can be used with other sensing mechanisms, such as capacitive touch sensors, which may also act as reflective surfaces. In addition to detecting the input position, the capacitor layer can also be used to determine a plurality of pressure parameters that are isolated but simultaneously input. The key is that the pressure sensing device can be deployed under or on the screen of the device. For example, if the ultrasound sensor is placed on top of the screen, it can be made transparent or avoid affecting the user's viewing angle during deployment. This approach differs from Apple's current model of deploying 3D Touch pressure sensing on the iPhone, which stacks multiple component layers underneath the smartphone display.

The current 3D Touch system measures the subtle capacitance changes between the iPhone panel glass and the hard metal sensor layer embedded in the device's backlight array. When the user presses the panel glass, the distance between it and the sensor is reduced, resulting in a decrease in capacitance. Although 3D Touch generates extremely accurate results, its design is very complex and squeezes valuable internal device space. The second drawback may be that the iPhone X does not have a built-in fingerprint recognition system. There are rumors this month that Apple wants to use the fingerprint reader as a candidate for face recognition. But now it seems that the company completely canceled the Touch ID and switched to Face ID. Some industry analysts suspect that Apple abandoned the program because of the technical problems faced by 3D Touch. But insiders said that Apple had fully bet on Face ID more than a year ago. As for Apple's initial preparation for the integration of the original 3D Touch technology into the iPhone X, or redesigning a solution, it is not known. In May of this year, it reported that the company used a thin film process to replace the metal backlight sensor by adding a thin film on the glass to greatly reduce the size of the sensor stack. After the iPhone X is officially released, the disassembly evaluation should uncover the mystery. But in any case, today's patent can solve the technical obstacles faced by under-the-screen fingerprint recognition, and it seems to be more precise and more robust than the film. As for whether Apple is ready to take full advantage of this technology, it will continue to use a single Face ID facial recognition system, which remains to be seen.