The wave of upgrading capacitive fingerprint biometric technology

In recent years, with the strong promotion of technologies such as smartphones, mobile internet, and artificial intelligence, biometric technology has rapidly popularized, and facial recognition and fingerprint recognition are no longer specifically used by public security and criminal investigation departments. People use fingerprints to unlock and swipe their faces to check in every day. When conducting identity authentication, a biological key must be provided. When making transaction payments, a biological key must also be provided. When signing a contract, a biological key must still be provided. All of this reflects the vitality of the development of the biometric industry.

According to statistics from IBG and Transparency Marker Research, the size of the biometric industry has reached $20 billion in 2019. With the accelerated development of the artificial intelligence market, the application fields of biometric technology are gradually expanding. By 2020, the market size will reach 23.3 billion US dollars, with an average compound annual growth rate of 15.7%, and it is in a fast growth channel.

Optical fingerprint technology is an early form of fingerprint recognition technology, which is generally used in company access control and clock in systems. These machines can generally see red or green light sources at the bottom of the collection area. Compared with the first generation of optical fingerprint recognition modules, capacitive fingerprint recognition has advantages such as small size and wide applicability. Nowadays, more and more devices are adopting capacitive fingerprint recognition.

Technically speaking, capacitive fingerprint recognition is more complex than optical fingerprint recognition. The main principle is to integrate pressure sensing, capacitive sensing, thermal sensing, and other sensors together. When the surface of the finger presses against the chip surface, the internal capacitive sensor will form a fingerprint image based on the charge difference generated by the peak and valley of the fingerprint wave, and then match it with the fingerprint library inside the phone to complete fingerprint recognition.

In addition to mature technology, capacitive fingerprint has a significant advantage, which is that its external performance is not limited by the type of screen. Whether it is LCD or OLED mobile phone screens, capacitive fingerprint can be easily compatible, which is the main factor why mobile phone manufacturers are adopting this fingerprint technology.

There are currently three main types of fingerprint recognition technologies used for smartphones: capacitive, optical, and ultrasonic. At present, in terms of fingerprint recognition types, the vast majority of smartphones are using capacitive fingerprint recognition. Generally speaking, the current fingerprint recognition module resolution of smartphones can reach 500dpi, and higher resolutions can improve the speed and accuracy of fingerprint information.

Is optical fingerprint unlocking better or capacitive fingerprint unlocking better? In fact, the final effect of the two unlocking methods depends on the performance of their built-in sensors. Unlike optical devices that often use manual adjustment to improve image quality, capacitive sensors use automatic control technology to adjust the sensitivity of fingerprint image pixels and local ranges, and combine feedback information to generate high-quality images in different environments.

The advantages of capacitive fingerprint sensors are small size, generally no distortion, good image quality, and easy integration into various devices. The electronic signals emitted by them will pass through the surface of the finger and the dead skin layer, reaching the living layer of the finger skin, directly reading the fingerprint pattern, thereby effectively improving the safety of the system.

Of course, like all other technologies, identifying and verifying a person's fingerprint through pre stored data in the system is also becoming a major new direction of exploration in the industry. Institutions, law enforcement agencies, hospitals and clinics, schools and colleges, gyms and fitness centers all use fingerprint unlocking to unlock large spaces and provide a new way for personal information verification.

On November 7th, at the Shanghai International Import Expo, German semiconductor technology company Infineon showcased a biometric payment card system that integrates fingerprint sensors. The non-contact payment card remains in the cardholder's hands throughout the transaction process, without the need to enter a password or sign authorization, which has also sparked heated discussions among industry insiders. Perhaps in the near future, there will be more trendy applications of biometrics!

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