Everything You Need to Know About the Fingerprint Sensor – Part One

Do you know when a fingerprint sensor came into being, what types it is, how it is structured,

how it operates, and what hardware and algorithms it uses?

The fingerprint sensor is one of the technologies that has played an important role in recent years in enhancing the security of various devices,

and most phone makers have incorporated different types of sensors from their products over the past few years, except for use. There are a variety of other uses on phones that we also explain;

These sensors, which have greatly improved since their inception, were once used only on phones and other high-end devices; but they are also available today in mid-range and even low-cost phones; in addition, they are also used in devices used to identify people. In recent years, there has been an increase in the number of beneficiaries in various fields. For this reason, we are determined to examine them from various aspects.


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The fingerprint sensor is one of the biometric or biometric security technologies (technologies based on the analysis of biological data related to biological characteristics of the human body such as fingerprint, iris structure, palm, acoustic patterns and limb shape) that are used for fingerprint recognition and detection. The user’s identity is used to log in or prevent him from logging into a system, and its structure is a combination of hardware and software features.


In this section, we first describe the most important events in human history of fingerprinting, its use for identifying people, the development of fingerprint sensors, and their use in various devices, including laptops and smartphones, from the 5th century to the 5th century.

In the year 6, Sheikh Fazlullah Hamadani first expressed his views on fingerprint identification in his book The Societies of History.
And In Year 6, Dutch physician Gouardard Biedlow, in his book Anatomy of the Human Body, details the features of palms and fingers or the papillary pattern (specific patterns of lines, bumps and indentations of each person’s finger).

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Image published in the book Anatomy of the Human Body

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This year, a French scientist named Paul John Cooley was the first person to receive fingerprints on paper and use a magnifying glass to identify the fingerprints of suspects and offenders and to arrest them.

In the year 9, Mr. Thomas Taylor, an American who studied microscopes, first came up with the idea that by matching fingerprints on the bodies and fingerprints of suspects, criminals and murderers.

In the seventies and eighties, English surgeon Henry Folds realized the importance of fingerprint recognition. He also devised a method for grouping fingerprints and another method for registering fingerprints with ink.

In the year 935,

Francis Galton began fingerprint-related research.
In year 6, an inspector, Eduardo Alvarez, was able to identify for the first time a murderer named Francesca Regas, whose blood fingerprint was left on the door.

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The first fingerprint identification office was set up in Calcutta, India, in the year 3.
In 2008, the first computerized fingerprint recording system with digital imaging and storage technology (AFIS) was developed and the FBI began using it.

سیستم AFIS

One year later, the FBI began the process of developing and developing sensor technology and extraction technology for dual curve lines and curved endpoints, resulting in the prototype of a fingerprint.

 Early prototype sensors used capacitive techniques to collect information about fingerprint features.

Finally, in the year 6 Thomson-CSF produced the world’s first fingerprint sensor.

The sensor used the technology of the world’s infrared cameras. The sensor, which was a kind of heat fingerprint sensor, was first shown to the public for the first time in two years.

The first fingerprint sensor was produced in year 6

The Fingerprint Sensor was first introduced in the OB3000, the first of its kind in the year, and it was launched as the first device equipped with a fingerprint sensor.

Subsequently, the MC 959 ID phone was introduced as the first fingerprint-free wireless sensor.

In the year 6, the HP Personal Assistant iPAQ h5450 was produced and released as the first fingerprint sensor.

 In the second year, the Fujitsu F505i also won the title of the first fingerprint sensor.

See this page for a list of all devices with fingerprint sensors from 1 to 2 years old.

Of course, the Pentax G3 was the first fingerprint phone to attract the attention of people, and has even been named as the first fingerprint sensor in some sources.

In addition to fingerprint recognition, the sensor could also be used to identify the user and quickly dial with the fingerprint, though Toshiba was the first company to continue this approach seriously, launching the G500 and G900 with a fingerprint sensor in the year.

Following the Toshiba HTC with the production of the P6500, Acer with the M900, LG with the GW820 eXpo in Year 2 and Motorola with the ES400 followed suit.

پنتک جی ۱۰۰

Of course, the public became familiar with fingerprint sensors when Apple introduced them for the first time in 5 years, Touch ID on the iPhone 5S.

  Samsung also unveiled its first fingerprint sensor in the year, the Galaxy S4.

The launch of these two handsets was actually the starting point for the official and widespread use of the fingerprint sensor on various phones.

Fingerprint sensor structure and how it works

There are six types of fingerprint sensors in general: optical, semiconductor (capacitive, radio, thermal, pressure) and ultrasonic sensors.

  Because most sensors are optical, capacitive and ultrasonic, we will explain more about them.

Let’s talk about how common fingerprint sensors work before talking about different types of sensors.

In most conventional sensors (but not all of them), the fingerprint image is first provided, and after identifying the different parts and patterning, the pattern is digitally matched to the stored sample.

The fingerprint scanner differs from the fingerprint sensor

Another important point to note before getting acquainted with the types of fingerprint sensors is the difference between the fingerprint scanner and the fingerprint sensor; many people know these two electronic pieces as one;

But that’s not the case at all, because the scanner is actually a whole piece that by making an electronic copy of the user’s fingerprint, encrypting it digitally, and finally sending the fingerprint to another piece,

It does the job of fingerprint recognition and detection, but the sensor is a piece embedded within the scanner that will be explained in a variety of ways,

The fingerprint pattern is converted into an electrical signal; in other words, the scanner receives the information and the sensor enables the information to be processed by the processor.

Optical or optical sensors

حسگر اثر انگشت اپتیکال

Optical sensors detect and recognize the optical fingerprint image.

The Optical sensors, also called visual or eye sensors, are the oldest type of sensor for fingerprint recording and comparison.

(Of course, prototype fingerprint sensors are said to have used capacitive fingerprint recognition techniques prior to the development of the first commercial fingerprint sensor) and were based on optical and photo capturing.

By analyzing the darkest and brightest points of the fingerprint, these sensors use several algorithms to identify unique fingerprint patterns (curved lines and other parts of it).

حسگر اثر انگشت گوشی

These sensors, like cameras, have a clear resolution and the higher the resolution, the higher the detail and

As a result, they are more secure; however, the images taken by these sensors are more contrasted than those of the camera.

Many diodes are installed per inch of these sensors to capture as much detail as possible. The surface of these sensors on which the finger rests,

It is very dark, so some of them are equipped with several rows of LED flashes that illuminate the image when shooting.

In addition, these sensors are equipped with an array of photodiode or phototransistor detectors to convert the light present in the light into electrical current.


fingerprint sensors such as resistive touch screens are rarely used and can only be found on low-cost devices;

However, now the cost of producing capacitive sensors that perform much better than their optical types has decreased, and they are also used in intermediate devices.

Of course, because in recent years smartphone makers have begun to use borderless screens in their products,

The use of small optical sensors that require little space and can be mounted beneath the display glass is back again!

Synaptic, the manufacturer of various sensors for phones and other devices, has unveiled the Natural ID FS9100 fingerprint sensor.

That the sensor works well under a 1mm thick glass and can also be used with a finger (capacitive fingerprint sensors do not recognize more fingers);

So maybe in the coming years we will see the use of optical sensors! Do you leave it up to us, dear readers, to judge?

Types of optical sensors

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Optical sensors operate in three different ways, producing three different types.

Optical Reflection Method

In this method, the optical sensor uses a phenomenon known as attenuated overall reflection. This phenomenon occurs when light enters the space between two conducting substances

(The space between them) and divide the light energy into two parts;

Then part of the boundary is reflected between the two materials and another part of the same part enters into the second material.

The amount of reflected light in terms of its total proportion to factors such as the angle of propagation of the light flux (the total amount of light emitted from a light source at a given time that is propagated in all directions);

However, with the onset of reflection, a certain amount of light from a certain angle reflects all light.

This is called the whole internal reflection; when the finger surface contacts the surface of the optic scanner,
A higher density of the finger surface than the scanner surface causes the light to cross the boundary between these two surfaces;

Therefore, only those light rays that are not in contact with the papillary surface of the finger are reflected.

Taking an optical image from the finger surface requires the use of an image sensor that can be CCD or CMOS depending on the scanner;

Of course, the sensors that use this method can be easily deceived and are unable to detect fingerprints or smears of different materials.

Optical Exposure

These types of sensors use an optical fiber array in which all waveguides are connected to the photo sensors at the output.

The sensitivity of each of these sensors allows for the absorption of light residual that passes through the point of contact of the finger to the array surface, and ultimately the image of the whole finger is generated based on the information of each photo sensor.

The advantages of these sensors are their precise operation and deception, and their disadvantages include the complexity of the structure.

Non-contact sensors

You don’t need to place your finger on the surface of the scanner to work with these sensors; you just need to place your finger near the scanner hole;

Next, several light sources from different angles shine through the finger, then the lens in the center of the scanner,

Transmits the collected data to a CMOS image sensor that can convert the information into a finger image.

Some optical sensors are equipped with other types of detectors, such as paired charge devices or CCDs, which are also light sensitive and can produce images with a great range of shades of gray;

Of course, because fingerprint recognition does not require low light sensitivity and a wide range of gray shades, and on the other hand CCD image sensors are more expensive, they are less expensive to use than CMOS sensors.

Advantages and Disadvantages

Optical sensors have relatively good accuracy, but because they are designed based on two-dimensional image recognition, with fingerprint printing on the inkjet printer,

It can be easily deceived; therefore, these sensors are not suitable for devices that require high security.

And they will probably be completely abolished in the very near future; however, this problem can be partially solved by using electro-optical imaging.

To use this technique, you first need to pass a certain voltage through a light-emitting polymer coating and place your finger on the cover to create a little flow of light.

 Using this technique will make the image of the troughs remain dark and create a high contrast image.

Another disadvantage of these sensors is that factors such as light deflection or dirt on the scanner surface such as dirt or grease and scratches affect their performance.

Semiconductor or semiconductor sensors

The basis of the performance of these sensors is to utilize semiconductor features to capture one-finger finger image by changing contact points. The highest points of the small finger-bumps with the scanner surface. We now introduce different types of sensors.

Capacitive sensors

حسگر اثر انگشت خازنی

Currently, capacitive sensors are the most common type of fingerprint sensor and are embedded in most smartphones with the highest level of security.

These sensors have a small electronic device called a capacitor.

In this type of capacitors, instead of the traditional finger-shooting technique, several rows of small capacitive circuits are used to collect data.

You probably know that the capacitors are capable of storing electronic current and can be used to record fingerprint details by connecting to small conductive screens on the surface.

When the curved lines of the fingers touch the conductive plates, the current stored in the capacitors changes slightly.

However, the air gap causes the capacitor flow to remain almost unchanged. Next, the operational amplifier integrator circuit is used to track these changes that the analog to digital converter can record.

The capacitors are much more secure than optical sensors

When this information is recorded digitally, it can be analyzed to obtain unique and distinctive features for each individual. It can also be stored for future comparison.

What makes optical sensors especially intelligent is that they are more difficult to deceive than optical sensors;

Because it is not possible to capture just one photo of the data that these sensors identify and give the user access to the device,

Forged and duplicated and because different materials create different currents in capacitors (which are very different from each other),

It is difficult to deceive them in the true sense of the word. Hardware or software hacking is the only real and potential threat to the security of these sensors.

کیت حسگر خازنی

By incorporating capacitors in sensors enough that there are usually hundreds or even thousands of sensors in one sensor,

One can only obtain a very detailed image of curved lines and fingerprints recesses and bumps using only electronic current.

One of the similarities of capacitive sensors with their optical types is that the greater their resolution by adding a larger number of sensors, the greater their security.

حسگر اثر انگشت خازنی

In the past, capacitive sensors were expensive because they had many components in their detection circuit;

For this reason, the designers of these sensors have tried to reduce the number of capacitors by utilizing newer designs and SWIP sensors;

Because when the user draws their finger on these sensors; they collect data with fewer sensors by refreshing the sensor outputs and data;

Of course, these sensors were annoying, and the user had to swipe them several times to correctly identify the fingerprint;

Nowadays, fingerprint sensors are much more common than swap sensors.

Advantages and Disadvantages

These sensors have features and features beyond fingerprint recognition, and their new models support features such as using gestures and swapping to do some work.

The sensors, which are soft buttons, can also be used as navigation buttons.

Other features of capacitive sensors include the sensitivity to pressure and the ability to interact with other elements of the phone’s interface (in some cases, of course);

We should also give you the good news that the cost of producing these sensors is still falling.

Other disadvantages and advantages of these sensors are their low cost and reliability and their disadvantages include the need to install a large number of capacitors in these sensors.

Also, these sensors, like optical sensors, are sensitive to the material that the finger can be impregnated with.

Radio frequency scanners

حسگر اثر انگشت رادیویی

The structure of radio frequency sensors consists of an array of sensing elements, each of which acts as very small antennas.

These sensors, which are actually radio frequency modules, generate low-intensity waves and send them to the scanned surface of the finger, then each antenna receives reflection waves from papillary fingerprints.

The magnitude and magnitude of the induced electron driving force of each microenvironment depend on the presence or absence of the highest fingerprint points near them.

Finally, the resulting stress matrix (the analysis of the waves sent by the antennas and the received waves) becomes a digital fingerprint image.

Advantages and Disadvantages

One of the great benefits of these sensors is that they can detect fingerprints even from the skin layer beneath the finger surface;
Therefore, this method was used to identify fingerprints of damaged and dry fingers.

In this method, due to the physiological properties of the skin being examined, the probability of cheating the sensor is approximately zero percent;

However, if the finger is not properly positioned on the surface of the fingerprint, its performance will be unstable.

Pressure sensors

In pressure sensors, an array of electrically-charged materials or a piezoelectric effect (substances that produce electricity by compression) are sensitive to pressure.

When the finger rests on the surface of these sensors, the protrusions of the curve of the fingerprint put pressure on part of the piezoelectric array,

But dislocations do not create pressure; this process causes the voltage generated by the piezoelectronics to become a fingerprint image.

These sensors are quite thin and are usually used in electronic devices. One disadvantage of early pressure fingerprint sensors was that their durability reduced their performance;

Because the protective layer on the surface of the sensor scanner reduced fingerprint contrast

There are two types of pressure sensors:

Conductive coating sensors

The sensors have a flexible coating that covers a double layer of electrode.

Sensors with microelectromechanical chips

These sensors use very small silicon switches that are mounted on silicon chips and when the fingerprint curves contact the switch, the switch closes and the fingerprint is electronically detected.

Advantages and Disadvantages

Pressure sensors can be designed in such a way that they are sensitive to pressure and perform different tasks depending on the pressure;

Doing different things in apps can be one of the applications of this type of design, such as when the map app is running,

You can zoom in on a part of the map by gently pressing the sensor. Of course, these sensors also have several disadvantages, including low sensitivity, low security (easily deceived), and vulnerability to high pressure.

Thermal sensor

Thermal scanners use sensors containing piezoelectric elements (materials that generate electricity by heat gain).

This type of design solves the problem of temperature difference and its conversion to heat.

The function of these sensors is that when the finger is placed on the sensor scanner, the temperature map of the finger surface is based on the temperature of the protruding points of the finger protrusions that contact the piezoelectric material, and

Also, the air temperature between these bumps is created and then converted into a digital image.

advantages and disadvantages

This method has many advantages, including high resistance to static discharge, stable operation at a wide range of temperatures, and high security and non-deception.

But the biggest disadvantage of thermal sensors is that the temperature change is dynamic, and it only takes about 2.5 seconds to adjust the temperature of the sensor surface to the temperature of the curved lines and fingerprints that come in contact with the sensor surface and to erase the fingerprint image.

While the fingerprint heat sensor can operate at a wide range of temperatures, when the ambient temperature is close to the surface temperature of the finger, the sensor needs heat to create a temperature difference of at least one degree Celsius.

Ultrasonic or ultrasonic sensors…

حسگر اثر انگشت فراصوت

Sensors are the latest type of fingerprint sensors and are used on new phones as well. The sensors were first embedded in the Le Max Pro with Qualcomm’s Sense ID technology.

These sensors are equipped with transmitter and receiver to accurately record fingerprint details and send ultrasonic pulses to the fingerprint located on the sensor surface to identify the fingerprint;

Some of these pulses are absorbed by the finger, and some of them return to the sensor depending on the curve lines, troughs and other finger details.

Ultrasound sensors use the waves to detect fingerprints

These waves are not audible and there is no microphone to hear them inside the scanner, but instead a number of sensors embedded at different points on the scanner surface can detect the amount of mechanical stress (force exerted on the surface) and calculate the intensity of the reflected waves at different points. Scanner surface, be used.

Longer scans allow you to capture and record depth data and thus reproduce high-resolution 3D fingerprints.

In these sensors, the distance between the waves transmitted by the sensors to the curved lines and bumps and indentations of the papillary patterns is measured using the echo waves reflected from different parts of the fingerprint.

Advantages and Disadvantages

The image quality of these fingerprint sensors is 5 times that of other sensors; it is very difficult to deceive these sensors;

Because in addition to receiving information on papillary patterns, they can also analyze other information such as pulses; in addition, the ability to scan these sensors in 3D makes it much more difficult to deceive them than other types of sensors.

The security of these sensors is so high that some hackers find it impossible;

Because recently a user has succeeded in capturing the image of his fingerprint on the glass, image processing in Photoshop, and finally 3D modeling using 3ds Max software and finally deceiving fingerprint printing with the advanced 3D printer of the Galaxy S4!

So it is certainly difficult to deceive ultrasonic sensors, but it is not impossible; in general, ultrasonic sensors are almost imperfect, and the high cost of production is their only disadvantage.

One of the disadvantages of these sensors that can be very annoying to users is their disruption in cold weather;

Because in the winter the toes become a little smaller and dry, and the drying of the fingers results in cracks and abrasion.

The new generation of fingerprint sensors

Sensors below the screen

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As you know, several phone makers have been using the large,

non-marginal or at least low-screens screens for many years (from flagships to cheap ones);

But having different sensors and a selfie camera is a big obstacle to using these phones;

That’s why different companies are using tricks like making a small cut at the top of the screen

to install selfie cameras and other sensors or using pop-up selfie cameras.

(The selfie camera hidden inside the handset that moves up and down using a scroll bar

(the user can lift it up while using it) and occupies no space in front of the screen)

 This problem has been partially solved, and the use of a fingerprint sensor inside the screen is another solution.

Although Apple, Samsung, and LG, considered to be giants of the mobile industry,

made the first plans to use these sensors;

But for the first time, the not-so-prominent Chinese company Vivo implemented the technology

and launched the first X-Plus UD-equipped fingerprint sensor in the world;

But the Vivo X was the first fingerprint sensor to be mass-produced and marketed.

ویوو ایکس 20 پلاس UD

After the launch of these two handsets, the other phones were introduced one after the other with a fingerprint sensor on the screen in years 1 and 2.

 Their names are as follows:

View Nexus
Vivo Wei 11
Huawei MITSR Porsche Design
Meizu 16
Meizu 16 Plus
Nokia 9 Pure View
Huawei Mate 20 Peru
· Oneplus 6t
Xiaomi May 8 Peru
Xiaomi May 8 Explorer
Oppo 17
OPRO R 17 Peru
Galaxy S 10
Galaxy S 10 Plus
Some sensors perform really well, for example, the Meizo 2 and 4 Plus, and the OPPO 17 and R 17 Pro, respectively, unlock the phone in just 1.2 seconds and 2.8 seconds, respectively.

Comparison of optical and ultrasonic sensors

مقایسه حسگرهای اپتیکال و فراصوت

Some sensors are on-screen optical and some are ultrasonic. In optical sensors, such as the Nokia 2Power View Sensor, the Huawei Mate 20 Pro One Plus 6T will first illuminate several fingerprint sources,

Then a very small camera with a built-in snapshot captures the fingerprint and matches it with the stored fingerprint sample; however, this sensor is only available on OLED displays;

There are gaps in the display panel that can be used to install the lamps used for exposure during shooting.

Some sensors inside the optical display use a capacitive measurement method to detect the actual finger to increase the security of these sensors.

They can also be enlarged to make these sensors easier to use and improve their performance.

The sensors below the ultrasound display are incompatible with some types of screen savers

On-screen sensors will become increasingly ultrasonic in the future; Qualcomm unveiled its new 3D embedded in-screen ultrasound sensors last year

And Samsung has used it this year in its latest flagships, the Galaxy S4 and S4 Plus;

However, ultrasonic sensors are not as popular as other types of sensors, since they are not well compatible with some screen savers.

And that limits their ability to correctly identify the fingerprint – but on the other hand, the use of sensors that can be embedded in the screen has made the frame around the screen narrower than ever.

Comparison of different generations of on-screen Qualcomm ultrasound sensors
So far, four generations of these sensors have been released, giving a brief explanation of each.

The first generation

These sensors were the first ultrasound sensors capable of 3D imaging

and use of light instead of light for imaging, and their superiority over optical sensors was clear.

Second generation (3D sonic)

The benefits of these sensors over their predecessors include greater security and speed,

and easier use because of the surface space.

Third Generation

These sensors can be used beneath the glass to a thickness of 1 micron,

while second-generation sensors could only be used beneath screens of up to 2 microns in thickness;

Therefore, the use of these sensors reduces the screen thickness,

which reduces its quality and durability.

The fourth generation

The latest generation of Qualcomm’s on-screen fingerprint sensors have increased by 2 percent faster than their predecessors,

and can unlock the phone in just 1.5 seconds;

This increase in speed and security is due to the use of DSP Acceleration technology in these sensors;

Other benefits of this technology include a 5% increase in sensor speed,

especially when the temperature is low and the fingers are dry (when exposed to direct sunlight).

Qualcomm’s latest sensor was first used on the Vivo X 23

The advantages of ultrasound sensors over optical sensors

More precision due to the 3D rendering of the fingerprint
Do not fool the sensor by taking a picture or a template from your fingerprint
No need to use light for imaging (Using light over time can weaken the screen)

The ability of ultrasound to pass through glass and metal with a thickness greater than 5 micrometers
Better detection of wet or greasy fingerprints, soot contamination or other contamination than optical sensors

Much less Thickness (2nd Generation Thickness of 2nd Generation Qualcomm Ultrasound Sensors and 2mm Optical Sensors Thickness)

Of course, the widespread use of ultrasonic sensors does not mean the end of the road for optical sensors and their use is still cost effective.

Earlier this year Oppo introduced a new optical sensor that can detect up to 5 times more space than optical sensors;

Also, ultrasonic sensors cannot be used under screens more than 1 micron thick.

And placing the screen saver on the screen of phones equipped with ultrasonic sensors disrupts their performance.

Side fingerprint sensors

حسگر اثر انگشت کناریحسگر اثر انگشت کناری

Putting a fingerprint sensor next to or behind the phone is another trick for different companies to gain more space in front of the phone and use a larger, frameless display;

Because these sensors are usually integrated into the phone’s power button, and when one’s finger is pressed on the power button, the phone is unlocked; He does not see the phone, and the phone suddenly locks….

حسگر اثر انگشت کناری

This can certainly be annoying to the user; you can only fix a part of your finger that has no fingerprint,

Hover over the power button so that only the phone’s screen will light up and the screen will display a lock screen;

Of course, the Galaxy S 10 has a cool feature that lets you turn on the phone twice by tapping on the screen.

It is difficult for some people to use the fingerprint sensor

Also, because the scanner surface has less space for these phones;

you have to be more careful when placing your finger or even have to place your hand

on it several times to correctly identify the fingerprint (just like the swipe sensors);

Of course, these sensors also have advantages over back-end sensors;

usually users of phones with a fingerprint sensor built into the back of the phone,

When they are just buying a phone;

they cannot easily find the exact location behind the phone without looking at the back of the phone;

A problem that some users of the Galaxy S4 and S4 were heavily involved with at the beginning;

In addition,

people who have small hands and want to work with large phones may also have problems with ear sensors;

So the sensors below the screen appear to be the best choice for phones right now.

Already the handsets of the Ann Pro, Galaxy A and Galaxy F are equipped with a side fingerprint sensor

Multi-finger sensors

حسگرهای چند انگشتی

These types of sensors are capable of scanning multiple fingers at a time, increasing the speed of identification. Some of these sensors are known as 2 + 1 + 2 sensors,

They can scan and identify four fingers simultaneously with high speed, accuracy and quality.

Most of these sensors, which are five times better than single-finger scanners, can scan in addition to fixed fingerprints,

The fingerprint can also be detected; it can also be used to scan children’s fingerprints.

حسگر  اثر انگشت چند انگشتی

More fingerprint information can be obtained using fingerprint sensors

Some of these sensors come with a software development kit or SDK that allows you to scan,

segment, or even optimize fingerprinted images.

One of the great benefits of these sensors is the ability to scan two thumbs at the same time,

allowing for more fingerprint information.

Also, using this sensor no longer requires separate printers for fingerprint printing.

Using these sensors in offices and organizations such as border guards,

the police department, the passport office,

as well as to identify or electronically register or participate in elections can greatly speed up the process of authentication.

نمونه اثر انگشت

Non-contact swap sensors

حسگرهای سوایپی بدون تماس

To use these sensors, which are capable of simultaneously scanning four fingers and three-dimensional fingerprint scanning,

you do not need to place your hand on the scanner and simply move your hand slowly over the scanner.

Other features of this scanner include fingerprint recording in less than five seconds,

3D scanning of curved lines, finger surfaces and curved portions,

Compatible with flat and rotary fingerprint databases,

wet and dry fingerprint scanning, light and dust resistance, and easy integration into equipment that requires authentication.

(Such as kiosks, electronic gates and turnstiles).

Algorithms used to increase the security and speed of sensors

امنیت حسگر اثر انگشت


different types of sensors have the same hardware and only use different algorithms

(to detect key fingerprint details) that vary their speed and accuracy,

They are a little different.

Each sensor is equipped with a dedicated IC that interprets the scanned information

and converts it into a form that is useful to the main processor of the phone and that the processor can use.

The algorithms used in fingerprint sensors are usually used to find curved lines

and other fingerprints or to divide curved lines into two branches.

These details are called fingerprint patterns, along with other individual finger-specific details.

When matching the recorded fingerprint to the scanned sample,

not all parts of the two fingerprints will be matched to increase speed,

and only the same specific details will be matched on each finger;

 If several of these details match, both fingerprints are the same;

Using this method not only reduces the processes required for fingerprint matching,

but also prevents errors when the scanned finger is dirty and impregnated with different materials.


in sensors that use this method to match recorded and scanned fingerprints,

it is enough to scan only a portion of the fingerprint located between the sensor.

One of the most important issues to consider when designing a fingerprint sensor

is to protect information security and protect it against code or apps that can be hacked.

To accomplish this, one had to register their fingerprints in addition to creating a password,

instead of uploading information online (in some systems, the user was required to authenticate;

The registered sample can be stored and maintained in its database as well as on the user’s device),

using an ARM-based processor to safely store this information on physical chips.

These processors are used to store data on chips from TrustZone or TrustZone technology
(Extensive security technology for Cortex-based systems and ARM architecture)

Based on the use of the Trusted Execution Environment, or TEE

(Secure CPU environment to ensure confidentiality and secure data protection)

Created, use. Verified personal information such as the original password is only available for applications using the TEE environment client interface.

The TEE Secure Environment can also be used for other encryption processes and for direct communication

with other secure hardware platforms such as fingerprint sensors to prevent any software spying and spying.

Qualcomm and Apple are also using separate components (secure environments)

on their main processors to enhance fingerprint information security that running operating system applications cannot access.


all fingerprint sensor companies use this method in various ways to protect sensitive data.

Also the Fidoo Alliance or the Fast Online Identification Alliance (active in creating new authentication standards to reduce password dependency)

It uses the same secure hardware environments to communicate between hardware

and online systems to identify each other and thus strong encryption protocols;

So users can only scan and register their fingerprints on websites and online stores

and enter their passwords the next time.


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