Performance characteristics of common fingerprint sensors!

Because of its unique detection technology, it can detect the dermis, which is very suitable for wet and dry fingers. The thickness of the surface material of the sensor is about 100 times that of other capacitive fingerprint sensors, and it has good durability. The antistatic index reaches 15KV. 2. Introduction of inductive fingerprint sensor The main manufacturer of inductive fingerprint sensor is AuthenTec Company of the United States, which owns the technology patent of inductive fingerprint sensor. At present, AuthenTec Company provides two series of fingerprint sensors, FingerLoc series and EntréPad series. AF-S2, AES3400 and AES2500 series (including AES250 1 and AES25 10) are widely used in China. Among them, AF-S2 is the first generation fingerprint sensor introduced by AuthenTec Company, and AES2500 series is a scratch fingerprint sensor. AES3400 is a new generation fingerprint sensor introduced by AuthenTec. Because of its small acquisition window, it is generally not suitable for general equipment, and is mostly used for special equipment such as PDA. The main performance indexes of AuthenTec fingerprint sensor are shown in the following table. Author company AF-S2 fingerprint sensor performance index table product summary product picture product manufacturer American AuthenTec company product model AF-S2 acquisition principle inductive technical parameter resolution 250DPI grid number 128× 128 single picture. Image size (bytes) 16K acquisition window size14.5x14.5mm antistatic index 8 kV working temperature 0 c to+70 c service life unpublished environmental humidity unpublished dry finger adaptability general wet finger adaptability. AF-S2 inductive fingerprint sensor with poor evaluation is the first generation semiconductor fingerprint sensor developed by AuthenTec company by using its patented technology TurePrint technology. This fingerprint sensor was once the mainstream fingerprint sensor in the market in 2002, and it was widely adopted by manufacturers who developed fingerprint products from 200/kloc-0 to 2002. In recent years, because new fingerprint sensors with better performance have been put on the market, they are no longer used in new fingerprint products developed by fingerprint manufacturers in recent years. The characteristics of this fingerprint sensor are: large-scale application and relatively stable sensor performance. Its disadvantage is that the resolution of the sensor is low, only 250DPI, which will affect the effect of some fingers with fine fingerprint (such as women). In addition, the anti-static index of the fingerprint sensor is low (only 8KV, the current general requirement is15kV); Fingerprint sensors are generally suitable for wet and dry fingers, especially for wet fingers (or fingers coated with hand cream). In addition, the manufacturer did not disclose the service life information of the sensor. Authortec AES3400 fingerprint sensor performance index table product overview product picture product manufacturer American Authortec product model AES3400 acquisition principle inductive technical parameter resolution 500DPI grid 128× 128. Single image size (number of bytes) 16K acquisition window size 7.2×7.2mm antistatic index 8 kV working temperature 0 C to+70 C service life 1 10,000 times environmental humidity undisclosed dry finger adaptability general wet finger adaptability. General product evaluation AES3400 inductive fingerprint sensor is a new generation of semiconductor fingerprint sensor developed by AuthenTec company using its patented technology TurePrint technology, and its performance is improved to some extent compared with AF-S2. The characteristics of this fingerprint sensor are: large-scale application, stable sensor performance and acquisition resolution of 500DPI. Its disadvantage is that the acquisition window area is too small, only 7.2 × 7.2 mm, and the anti-static index of fingerprint sensor is low (only 8KV, the current general requirement is15 kV). Fingerprint sensors are usually suitable for wet fingers and dry fingers. 3. Introduction of Scraping Fingerprint Sensor In recent years, due to the application requirements of fingerprint technology in handheld devices such as PDA and notebook computer and the requirements of fingerprint sensor manufacturers to reduce the production cost of fingerprint sensors, scraping fingerprint sensors have been gradually applied, and almost all fingerprint sensor manufacturers have introduced scraping fingerprint sensors. Typical ones are: FingerChip scratch fingerprint sensor produced by Atmel Company in the United States, MBF3 10 scratch fingerprint sensor produced by Fujitsu Company in Japan, FPC 103B produced by FingerPrintCard Company in Sweden and AES2500 produced by AuthenTec Company in the United States. Compared with the planar fingerprint sensor, the technologies adopted by different manufacturers are quite different, for example, AuthenTec adopts inductive TurePrint technology, Fujitsu adopts capacitive direct detection technology, fingerprint card adopts capacitive reflection detection technology, and Atmel adopts heat-sensitive technology. The imaging method of scraping fingerprint sensor is: when a finger scratches on the fingerprint sensor, multiple images are collected, and then the collected images are spliced to form the fingerprint image of the whole finger. Therefore, the scraping fingerprint sensor can collect fingerprint images of a large area of fingers. However, the effect of collecting images will be affected by the speed at which users move their fingers. Scraping fingerprint sensor can only be used in the following applications: 1, relatively small handheld devices, such as mobile phones, PDA, etc. On which the area fingerprint sensor cannot be used due to the size; 2. For fixed individual users. The fingerprint scraping sensor requires the operator to scrape his finger every time he verifies the fingerprint. The speed and strength of finger scraping have great influence on fingerprint identification. Too fast or too slow scraping will lead to poor fingerprint image and affect the success rate of fingerprint comparison. Therefore, before using the scratch fingerprint sensor, users usually need to be trained for a period of time. For banking applications, the use of scratch fingerprint sensors requires careful training of tellers. In addition, if the fingerprint application is extended to the application for bank users (for example, some banks have already used some savings counter services, such as loss reporting and fingerprint verification, etc.). ), it is generally difficult to use. 3. Used in occasions where the operation time is not too high. Generally, the regional fingerprint sensor can be easily grasped by the operator as long as the finger is placed by hand. For the scraping fingerprint sensor, due to the working characteristics of scraping, it is generally not suitable for use in occasions with high time requirements. When used on PDA or portable computer, if the verification fails once, the operator can repeat the verification, because these applications have no strict restrictions on the operation time. However, the scraping type requires the operator to scrape his fingers carefully, and the scraping speed is strict. It is difficult to ensure that tellers scratch their fingers carefully every time when banks require tellers to come to the counter at a high speed. Generally speaking, the following indicators should be considered when selecting a semiconductor fingerprint sensor: 1, and the antistatic performance is generally required to be greater than 15kv, otherwise it will be easily broken down; 2. Resolution. Generally, it needs at least 256dpi, otherwise it is difficult to distinguish fine fingerprints, such as banks, hospitals, supermarkets and so on. 3. Adaptability to wet and dry fingers (especially fingers coated with hand cream). AuthenTec, Fujitsu MBF200, etc. Have different degrees of defects. 4. Service life requirements. The service life of the sensor is generally required to reach 6.5438+0.0000 times. 5. Consistency and adaptability of products. Because China is a vast country and people's fingerprints in different regions have different characteristics, we should generally choose products that have been verified in various regions.