"Fingerprint recognition is not a new technology. As early as 2011, moto atrix 4G already had fingerprint recognition unlocking function. However, due to the technical limitations at that time, the success rate of fingerprint recognition was not satisfactory. In 2013, apple added touch ID fingerprint recognition function to iPhone 5S. With the addition of Technology and fingerprint recognition function, Other manufacturers have also added fingerprint recognition to mobile phones. Are these fingerprint recognition functions really easy to use? What is the difference between positive identification and back identification? Next, let's talk about these issues.
Common fingerprint identification solutions in mobile phone industry
My colleague once wrote in "fingerprint identification is comparable to apple? Meizu MX4 Pro in-depth evaluation has sorted out the commonly used question recognition solutions in the mobile phone industry at this stage, and the author has improved them on its basis.
From the table, we can find that the main unlocking methods now include front pressing, back pressing, front sliding, back sliding and back pressing. The author will conduct a detailed test later. First, the author will talk to you about these fingerprint identification suppliers.
1、 Authentec (USA)
Introduction: authentec is the world's leading provider of fingerprint authentication sensors and solutions for PC, wireless devices and access control markets. On July 27, 2012, apple acquired the company for $356 million. Since then, authentec belongs to apple.
The fingerprint identification sensor developed by it is a semiconductor based on capacitance and wireless RF. The sensor is combined with the home key of iPhone and iPad, and the top layer is sapphire cover plate. The sensor is manufactured by TSMC, and the wafer level packaging is completed by Taiwan precision materials and Jingfang technology. Rimoonlight is responsible for the subsequent packaging and testing and the production of SIP modules.
Object oriented: Apple's mobile phones and tablet products do not provide any products and technologies to manufacturers in the same industry, but they can provide bank security and management services (I feel like paving the way for Apple pay).
2、 Synoptics validity (USA)
Synoptics is the world's leading design and manufacturing company for human-computer interface development solutions for mobile computing, communication and entertainment devices. It was founded in 1986 and headquartered in the United States. On October 17, 2013, it acquired validity, a biometric identification company, at a price of US $255 million, and officially entered the field of fingerprint identification.
Object oriented: the Samsung Galaxy S5 and HTC one Max released last year all adopt the Synaptics design scheme, but the slight difference is that the S5 adopts the combination of the front and home keys, while the HTC one Max adopts the scheme of placing the back on the back cover. Although the position of fingerprint identification is different, the scheme is indeed the same.
3、 Fingerprint cards AB (FPC)
Introduction: FPC is committed to developing, producing and selling biometric components and technologies to help confirm the identity of users by analyzing and comparing personal unique fingerprints. It is headquartered in Gothenburg, Sweden and listed on NASDAQ. It launched fpc1020, the world's first capacitive touch fingerprint sensor using Android smartphone and tablet.
Object oriented: there are many object-oriented objects. The well-known ones are vivo xplay 3S, Huawei mate7 and oppo N3. Both of them place the sensor on the back, but the unlocking method is slightly different.
4、 GOODIX huiding Technology (China)
Introduction: huiding technology was founded in 2002 and began to enter the touch industry in 2006. Huiding technology is based on the world's leading research and development of human-computer interaction technology and chip design. As the only strategic partner of MTK, huiding technology has rich experience in mass production of capacitive touch chips, perfect touch test system and test standards, and has more than 30 capacitive touch technology patents.
Object oriented: at present, there is only Meizu MX4 pro in the mobile phone market, which is also the first positive press fingerprint identification scheme created by domestic mobile phone manufacturers. The author is proud of this. It is really rare for domestic technology companies to do this.
Fingerprint identification principle of each mobile phone
For the four companies, the author has briefly introduced to you. Next, the specific implementation principles of several machine fingerprint schemes such as iPhone 6, Meizu MX4 pro, Samsung note 4, Huawei mate7 and oppo N3 are discussed. The following figure shows the simple process of fingerprint identification, and each mobile phone is specifically implemented in the fingerprint identification scheme. Huawei mate7 and oppo N3 adopt the same scheme, and N3 is an upgraded version of mate7 scheme. The actual principle is the same, so the author will explain it together below.
IPhone 5S / 6 fingerprint recognition principle:
The touch ID fingerprint sensor of iPhone 5S / 6 is placed in the home key. The surface of the home key sensor is made of Laser Cut Sapphire crystal, which can accurately focus the finger and protect the sensor. At this time, the sensor will record and identify the fingerprint information, and the stainless steel ring around the sensor button is used to monitor the finger, Activate the sensor and improve the signal-to-noise ratio. Then, the software will read the fingerprint information and find the matching fingerprint to unlock the phone.
In the fingerprint sensor part, the semiconductor sensor based on capacitance and radio frequency mentioned in the starting table has been verified in two layers. In the first layer, a fingerprint capacitive sensor is used to identify the fingerprint image of the whole contact surface. The second layer uses radio frequency technology and reads the signal reflected from the dermis through the sensing component under the sapphire chip to form a fingerprint image.
Capacitive sensing and identification: the finger forms one pole of the capacitance, and a silicon sensor array on the other side forms the other pole of the capacitance. The micro current is formed between the micro electric field carried by the human body and the capacitive sensor, and the capacitance height difference is formed between the peak and valley of the fingerprint and the sensor, so as to depict the fingerprint image
Radio frequency identification: transmit a low-frequency radio frequency signal to the dermis. Because the human cell fluid is conductive, read the electric field distribution of the dermis to obtain the most accurate image of the whole dermis, and read the electric field distribution of the dermis to obtain the most accurate image of the whole dermis. There is a driving ring outside the touch ID, which emits the RF signal.
After recording the fingerprint image, input its data into the database, and then touch ID can scan the fingerprint 360 ° in an all-round way and compare it with the database fingerprint data in the process of fingerprint verification. When the new fingerprint image and the database sample fingerprint match each other successfully, the fingerprint image can be used to strengthen and improve the sample information of the database, so that more sample information can be recorded, improve the success rate of fingerprint identification and successfully identify fingerprints from various angles.
Meizu MX4 Pro fingerprint identification principle
Meizu believes that the fingerprint identification experience on the back is not good, so Meizu chose huiding at the last moment. The MX4 Pro adopts huiding technology gt6618 / 28 fingerprint identification module. The following figure shows the specific parameters of this module. Finger flash mode in the working mode is the patented technology of huiding.
In finger flash mode, Meizu MX4 Pro can realize the integrated operation from rest screen to bright screen, then to wake up and finally unlock. In the lock screen state, the user can unlock by pressing the home key to light up the screen and staying on the home key for a while, which is the same as the unlocking implementation scheme adopted by iphone6 in the lock screen state. In addition, when the screen is lit up, both can unlock by touching the home key. Like Apple's iPhone 5S, huiding's fingerprint recognition is based on the principle of capacitive touch. In this case, isn't huiding technology infringing?
Is huiding technology infringing? Zhang Fan, chairman of huiding technology, said that huiding believes that there is no infringement. Long Hua, deputy general manager, explained that first, IC patents generally protect the layout of the chip, that is, the implementation scheme. Although the implementation principle is the same, the implementation method is different, so it is not infringement. Second, another important technology here is the packaging and module form of fingerprint identification chip. Huiding spent a lot of time developing packaging technology to form its own unique patent. And will not find Apple's packaging manufacturers, nor will they use very complex packaging methods like them.
I personally think that apple is a company that attaches great importance to patents. If huiding technology really infringes apple, Apple should not easily let them go. However, since Meizu was released, Apple has not made any official statement. Therefore, huiding technology should have no infringement.
Huawei mate 7 fingerprint identification principle
Huawei mate 7 adopts fpc1020 fingerprint identification scheme of FPC company in Sweden, which places the sensor in the back cover of the mobile phone. Although it is a press fingerprint identification technology, it should belong to contact type. Just gently place the phone in the unlocking area to unlock it.
Huawei mate7 fingerprint sensor is covered with a silver coating. There is also a ring of metal between the fingerprint identification area and the rear shell, which is similar to the stainless steel detection ring covering the iPhone 5S fingerprint sensing area. This metal ring can also serve as a finger trigger. In addition, the recognition area of the mature fpc1020 is the largest among other mobile phones at this stage.
Scheme used by oppo N3
Oppo N3 uses an upgraded version of fpc1020 - fpc1021. There is little difference between the two, so I won't repeat it. However, fpc1021 is 30% smaller than fpc1020, but it is still a little larger than the touch ID of iPhone. It's not suitable to put it on the front of Android phone. Therefore, oppo N3 puts it on the back.
Why Huawei mate 7 and oppo N3 adopt back fingerprint identification scheme
1. Design and aesthetics
The operations of Huawei mate 7 and oppo N3 comply with the changes of Android and adopt the method of virtual keys. Emui sets virtual keys inside the screen. If a fingerprint identification sensor is installed on the front chin for fingerprint identification, it will greatly reduce the overall appearance of the mobile phone. Although oppo N3 sets virtual keys outside the screen panel, However, if the fingerprint identification sensor is installed at the home key, it is very different from the oppo design language, so it is not necessary to do so.
2. Sensor size
Due to the size of the sensor, the front fingerprint identification sensor will occupy a large area, which challenges the narrow chin of Huawei mate 7 and oppo N3, while the back can also realize the fingerprint identification function, which is not too poor in convenience and practicability, and can ensure the integrity of the front design. Naturally, the back fingerprint identification will be selected.
The author personally believes that Huawei and oppo put the fingerprint identification sensor on their back, mainly because when using the mobile phone, their eyes are more on the front, while their attention on the back is much less. Therefore, giving users a beautiful front and putting the fingerprint identification sensor on their back is also based on the consideration of users. As for the back and the front, in addition to this reason, the author will introduce the advantages and disadvantages of the two later.
Principle of Samsung note 4 fingerprint identification scheme
Like apple, the Samsung note 4 fingerprint identification sensor also chooses to be integrated under the home key. However, the Samsung note 4 adopts the Synaptics & validity scheme, which belongs to the friction type. The unlocking menu setting process is also similar to that of the iPhone 5S.
Samsung Galaxy S5 sliding fingerprint recognition must slide from top to bottom. When your finger crosses the sensor, it will scan your fingers line by line. In this way, you must fix your posture, direction and cover the whole sensor before you can be recognized. This requires you to stroke and wipe in a fixed posture. Relatively speaking, the user experience will become much worse.
Why doesn't Samsung use push fingerprint recognition?
Fingerprint identification“
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