CN106295465A - A kind of fingerprint detector and electronic equipment - Google Patents

Abstract

The invention discloses a fingerprint detector and electronic equipment. The fingerprint detector comprises: a fingerprint identification module for identifying a user's fingerprint; a sensing device comprising at least two conductors arranged on the edge of the fingerprint identification module; The detection circuit is connected with each conductor respectively, and is used for detecting the capacitance value on the conductor. The conductor is a self-capacitance conductor. When the user's finger is close to the conductor, a corresponding self-capacitance will be generated on the conductor, so that by detecting the change of the capacitance value on the conductor, the user's finger on the fingerprint detector can be detected. Movement and movement direction, so as to respond correspondingly according to the movement and movement direction of the user's finger.

Description

A fingerprint detector and electronic equipment

technical field

The present application relates to the field of electronic technology, in particular to a fingerprint detector and electronic equipment.

Background technique

With the development of electronic technology, there are more and more portable electronic devices, such as mobile phones, tablet computers and other portable electronic devices.

In the current electronic equipment, this is a fingerprint detector. A fingerprint identification module is set in the fingerprint detector. The fingerprint identification module can detect the fingerprint information of the user of the electronic equipment, so as to realize the purpose of fingerprint unlocking, etc. This makes the electronic equipment more secure, but the current fingerprint detector has a single function, which makes the usage rate of the fingerprint detector lower.

Contents of the invention

Embodiments of the present invention provide a fingerprint detector and electronic equipment, which are used to solve the problem in the prior art that the functions of the current fingerprint detector are relatively single, thereby making the usage rate of the fingerprint detector relatively low.

Its specific technical scheme is as follows:

A fingerprint detector comprising:

A fingerprint identification module, used to identify the user's fingerprint;

A sensor comprising at least two conductors, each of the at least two conductors is respectively connected to a drive circuit that provides a drive signal, and the at least two conductors are arranged on the edge of the fingerprint recognition module;

The detection circuit is respectively connected with each conductor, and is used for detecting the signal to be processed on the conductor.

Optionally, the detection device includes four conductors, and the four conductors form a rectangle.

Optionally, the detection circuit includes:

a data selector, connected to each conductor respectively, for selecting a signal to be processed detected on a conductor;

A chopper-stabilized amplifier, configured to perform arithmetic processing on the signal to be processed output by the data selector, and output a first processed signal;

A demodulation circuit, connected to the chopper-stabilized amplifier, for demodulating the first processed signal output by the chopper-stabilized amplifier, and outputting the demodulated second processed signal;

A programmable gain amplifier, connected to the demodulation circuit, for performing gain processing on the second processed signal output by the demodulation circuit, and outputting a third processed signal;

A digital-to-analog converter connected to the programmable gain amplifier, configured to perform analog-to-digital conversion processing on the third processed signal output by the programmable gain amplifier, and obtain a fourth processed signal;

a filter, connected to the digital-analog converter, configured to filter the fourth processed signal output by the digital-analog converter, and obtain a fifth processed signal.

Optionally, the chopper-stabilized amplifier includes: a first switch, a second switch, a third switch, a fourth switch, a first capacitor, a second capacitor, a first integrator, and a second integrator, wherein,

One end of the first switch is connected to the input end of the first integrator, and the other end is connected to the data selector;

One end of the second switch is connected to the input end of the second integrator, and the other end is connected to the data selector;

After the third switch is connected in parallel with the first capacitor, both ends are respectively connected to the input end and the output end of the first integrator;

After the fourth switch is connected in parallel with the second capacitor, both ends are respectively connected to the input terminal and the output terminal of the second integrator;

The other input terminal of the first integrator is connected to the first power supply, and the output terminal is connected to the demodulation circuit;

The other input terminal of the second integrator is connected to the second power supply, and the output terminal is connected to the demodulation circuit.

Optionally, the demodulation circuit is specifically configured to eliminate the DC component in the first processed signal output by the chopper-stabilized amplifier, perform demodulation processing on the first processed signal from which the DC component has been eliminated, and output a second Handle signals.

An electronic device comprising:

case;

a processor disposed in the housing;

A fingerprint detector is connected with the processor, and the fingerprint detector is the above-mentioned fingerprint detector.

An embodiment of the present invention provides a fingerprint detector, which includes: a fingerprint identification module for identifying a user's fingerprint; a sensing device that includes at least two conductors, and the conductors are arranged on the edge of the fingerprint identification module; A circuit, respectively connected to each conductor, is used to detect the capacitance value on the conductor. The conductor is a self-capacitance conductor. When the user's finger is close to the conductor, a corresponding self-capacitance will be generated on the conductor, so that by detecting the change of the capacitance value on the conductor, the user's finger on the fingerprint detector can be detected. Movement and movement direction, so as to respond correspondingly according to the movement and movement direction of the user's finger.

In the embodiment of the present invention, the fingerprint detector can not only detect the fingerprint, but also determine the sliding operation of the user's finger on the fingerprint detector through the sensing device and the detection circuit on the fingerprint detector. Or whether the finger is swiping left or right on the fingerprint sensor. Therefore, the fingerprint detector can be operated by sliding the user's finger, thereby improving the functionality and practicability of fingerprint detection.

Description of drawings

Fig. 1 is one of structural representations of a kind of fingerprint detector in the embodiment of the present invention;

Fig. 2 is a schematic structural diagram of a detection circuit in an embodiment of the present invention;

3 is a schematic diagram of a circuit structure of a chopper-stabilized amplifier in an embodiment of the present invention;

Fig. 4 is the second structural diagram of a fingerprint detector in the embodiment of the present invention;

FIG. 5 is a third structural schematic diagram of a fingerprint detector in an embodiment of the present invention.

detailed description

In order to solve the problem of single function and low usage rate of the fingerprint detector in the prior art, an embodiment of the present invention provides a fingerprint detector, which includes: a fingerprint identification module for identifying a user's fingerprint; The sensing device includes at least two conductors, and the conductors are arranged on the edge of the fingerprint recognition module; the detection circuit is respectively connected with each conductor, and is used for detecting the capacitance value on the conductors. The conductor is a self-capacitance conductor. When the user's finger is close to the conductor, a corresponding self-capacitance will be generated on the conductor, so that by detecting the change of the capacitance value on the conductor, the user's finger on the fingerprint detector can be detected. Movement and movement direction, so as to respond correspondingly according to the movement and movement direction of the user's finger.

The above-mentioned scheme illustrates the main scheme of the fingerprint detector in the embodiment of the present invention. The technical scheme of the present invention will be described in detail below through the accompanying drawings and specific embodiments. It should be understood that the embodiments of the present invention and the specific technical features in the embodiments It is only an illustration of the technical solutions of the present invention, rather than a limitation. In the case of no conflict, the embodiments of the present invention and the specific technical features in the embodiments can be combined with each other.

As shown in Figure 1, it is a schematic structural diagram of a fingerprint detector in an embodiment of the present invention, and the fingerprint detector includes:

Fingerprint recognition module 101, the fingerprint recognition module 101 has included a plurality of detection sub-units, each detection sub-unit user detects part of the fingerprint information of the finger, the array formed by these detection sub-units can be used for the fingerprint recognition module, thereby realizing the user Fingerprint detection, and then the user's fingerprint information can be obtained through the fingerprint identification.

The sensing device 102 , the sensing device 102 is composed of at least two conductors, and the conductors are arranged on the edge of the fingerprint identification module 101 .

The detection circuit 103 is respectively connected to each conductor, and is used for detecting the capacitance value on the conductor.

In FIG. 1 , the sensing device 102 includes a first conductor and a second conductor, and the first conductor and the second conductor are self-capacitance conductors.

In the embodiment of the present invention, in order to realize the detection of the capacitance value of the first conductor and the second conductor, therefore, the detection circuit 103 is connected to the first conductor and the second conductor, and the detection circuit 103 is used to detect the first conductor and the second conductor. Capacitance value on the second conductor.

The working principle of the fingerprint detector will be described in detail below.

First of all, during detection, the detection circuit on the fingerprint detector will detect the capacitance values on the first conductor and the second conductor in real time.

If the user puts his finger close to the first conductor on the left, since the first conductor is a self-capacitance conductor, the capacitance on the first conductor will change, that is, the capacitance on the first conductor will increase. At this time, the detection circuit 103 connected to the first conductor can detect the change of the capacitance value on the first conductor, that is, the detection circuit 103 can specifically detect the capacitance value on the first conductor, and finally the detection circuit 103 will use the value The capacitance value of the first conductor is output in the form of , that is, the capacitance value on the second conductor is represented by a numerical value.

Of course, if the user's finger is close to the second conductor on the right, the capacitance value on the second conductor will also change, that is, the capacitance value on the second conductor will increase, and the detection circuit 103 will detect the same The capacitance value on the second conductor finally characterizes the capacitance value of the second conductor in the form of numerical value.

Then, the electronic device installed with the fingerprint detector judges whether there is an object close to the first conductor or the second conductor by comparing the detected capacitance value with the preset threshold value, for example, it detects that the capacitance value on the first conductor exceeds When the preset threshold value is set, it means that there is an object approaching the first conductor. At this time, the electronic device will respond accordingly. If it detects that the capacitance value on the second conductor exceeds the preset threshold value, it means that there is an object approaching the second conductor. At this time, the electronic device will also respond accordingly.

Further, in the embodiment of the present invention, the sliding operation of the user's finger on the fingerprint detector can also be realized through the first conductor and the second conductor. Specifically, if the user slides the finger from the left to the right of the fingerprint sensor, the user's finger will first approach the first conductor, and at this time the capacitance value on the first conductor will increase, and the user's finger will gradually move to the right. When sliding, the user's finger will move away from the first conductor and gradually approach the second conductor. At this time, the capacitance value on the first conductor will decrease, while the capacitance value on the second conductor will gradually increase. The fingerprint detector can determine that the user is performing a sliding operation by detecting that the capacitance value on the first conductor decreases from a large value, and can further determine the use The user's fingers slide from left to right.

In the same way, the same is true for the process of sliding from right to left, that is, it will first detect the process of the capacitance value of the second conductor from large to small, and then detect the process of the capacitance value of the first conductor from small to large, and finally The sliding operation of the user's finger on the fingerprint detector from right to left can be determined through the change of the capacitance value.

Further, in order to ensure that the detection circuit 103 detects the capacitance values of the first conductor and the second conductor, as shown in FIG. Programmable gain amplifier 204 , digital-to-analog converter 205 , filter 206 .

Specifically, the data selector 201 is used to select and output the signal detected on a certain conductor. In simple terms, the data selector 201 selects and outputs signals.

The chopper-stabilized amplifier 202 is configured to output a first processed signal corresponding to the detected capacitance value according to the detected capacitance value. As shown in FIG. 3, the chopper-stabilized amplifier 202 includes a first switch 301, a second switch 302, a third switch 303, a fourth switch 304, a first capacitor 305, a second capacitor 306, a first integrator 307, In the second integrator 308 , one end of the first switch 301 is connected to the input end of the first integrator 307 , and the other end is connected to the data selector 201 .

One end of the second switch 302 is connected to the input end of the second integrator 308 , and the other end is connected to the data selector 201 .

After the third switch 303 is connected in parallel with the first capacitor 305 , both ends are respectively connected to the input terminal and the input terminal of the first integrator 307 .

After the fourth switch 304 is connected in parallel with the second capacitor 306 , both ends are respectively connected to the input terminal and the output terminal of the second integrator 308 .

The other input end of the first integrator 307 is connected to the first power supply, and the output end is connected to the demodulation circuit 203 .

The other input end of the second integrator 308 is connected to the second power supply, and the output end is connected to the demodulation circuit 203 .

When the signal output by the data selector 201 is input from the first integrator 307, the first switch 301 and the second switch 302 are closed, the third switch 303 and the fourth switch 304 are disconnected, and the second integrator 308 is reset, at this time The output of the first integrator 307 is Vint1, where Vint1 can be obtained by the following formula:

Vint1=Vup+(Vup-Vdw)*Cs/C1

Among them, Vup represents the voltage value of the first power supply connected to the first integrator 307, Vdw represents the voltage value of the second power supply connected to the second integrator 308, Cs represents the capacitance value on the conductor, and C1 represents the Integrating capacitance value on the first integrator 307 .

Similarly, when the signal output by the data selector 201 is input from the second integrator 308, the first switch 301 and the second switch 302 are opened, the third switch 303 and the fourth switch 304 are closed, and the first integrator 307 is reset , the output of the second integrator 308 is now Vint2, where Vint can be obtained by the following formula:

Vint2＝Vdw+(Vdw-Vup)*Cs/C2

Among them, Vup represents the voltage value of the first power supply connected to the first integrator 307, Vdw represents the voltage value of the second power supply connected to the second integrator 308, Cs represents the capacitance value on the conductor, and C2 represents Integrating capacitance value on the second integrator 308 .

Further, in order to improve the anti-noise capability of the detection circuit, Vdw-Vup needs to be maximized, so Vup should be as close to the power supply voltage as possible, and Vdw should be as close as possible to the ground voltage, while ensuring the normal operation of the integrator op amp.

Through this circuit structure, the output result of the chopper-stabilized amplifier 202 can be directly proportional to the capacitance value on the conductor, so the change of the capacitance value on the conductor can be determined through the output result of the chopper-stabilized amplifier 202 .

Since the final output result needs to be a numerical value representing the capacitance value on the conductor, after the chopper-stabilized amplifier 202 outputs a first processing signal corresponding to the capacitance value, the demodulation circuit 203 will receive the first processing signal and demodulate The first processed signal obtains a second processed signal, and then outputs the second processed signal to the programmable gain amplifier 204, and then the programmable gain amplifier 204 performs gain processing on the signal output by the demodulation circuit, that is, doubles the amplification The signal, thereby obtaining a third processed signal.

After the programmable gain amplifier 204 performs gain processing on this signal, the third processed signal output will be transmitted to the digital analog-to-digital converter 205, and the digital analog-digital converter 205 is used for the third signal output by the programmable gain amplifier 204 Process the signal for analog-to-digital conversion processing. Specifically, since the capacitance value is finally obtained in numerical form, it is necessary to convert the digital signal output by the programmable gain amplifier 204 into an analog signal, so the digital-to-analog converter 205 converts the output signal of the programmable gain amplifier 204 into an analog signal. The gain-processed digital signal is converted to an analog signal.

After the digital-to-analog converter 205 converts the digital signal into an analog signal, the digital-to-analog converter 205 will send the fourth processed signal, that is, the analog signal, to the filter 206 for processing, and the filter 206 is used to process the digital-to-analog converter The analog signal output by 205 is filtered, which means that the analog signal output by the digital-to-analog converter 205 may not be a pure analog signal, so it is necessary to filter out the digital signal in the analog signal through the filter 206, and filter out possible Noise, etc., so that the final output analog signal is more accurate and complete.

Through the description in the above embodiment, the fingerprint detector can not only realize the detection of the fingerprint, but also can determine the sliding operation of the user's finger on the fingerprint detector through the sensing device 102 and the detection circuit 103 on the fingerprint detector , that is, whether the user swipe left or right on the fingerprint sensor. Therefore, the fingerprint detector can be operated by sliding the user's finger, thereby improving the functionality and practicability of fingerprint detection.

Further, in the above-mentioned embodiment, the sensing device 102 of the fingerprint detector includes two conductors, so as to ensure that the sensing device 102 can detect the left and right sliding operation of the user's finger on the fingerprint detector.

In order to enable the sensing device 102 on the fingerprint detector to detect the sliding operation of the user's finger in four directions on the fingerprint detector, the sensing device 102, in addition to the first conductor and the second conductor, also includes Can include a third conductor and a fourth conductor (as shown in Figure 4), in Figure 4, the third conductor and the fourth conductor are all set on the edge of the fingerprint recognition module 101, the third conductor and the fourth conductor The conductor and the second conductor enclose a rectangular area, and the fingerprint recognition module 101 is located in the rectangular area.

The sensing device 102 composed of the first conductor and the second conductor can detect the left sliding and right sliding of the user's finger on the fingerprint detector, and the upward sliding and sliding of the user's finger can be realized through the third conductor and the fourth conductor. Sliding, of course, the detection method of the capacitance values of the third conductor and the fourth conductor is the same as that of the first conductor, and will not be repeated here.

Therefore, the fingerprint detector shown in Figure 4 can detect the sliding operation of the user's finger on the fingerprint detector from left to right, from right to left, from top to bottom, and from bottom to top. swipe action. Furthermore, it is ensured that the fingerprint detector can detect the sliding operation of the user's finger on the fingerprint detector in various directions.

Further, in the embodiment of the present invention, the fingerprint detector can also have the structure shown in Figure 5, in the structure shown in Figure 5, the sensing device 102 in the fingerprint detector includes 6 conductors, which The 6 conductors form a regular hexagon. The structure on the regular hexagon can more accurately detect the sliding of the user's finger on the fingerprint detector. Sliding at the lower corner, the sliding operation can be detected more accurately by the fingerprint detector shown in FIG. 5 .

Certainly, in the embodiment of the present invention, besides the structure shown in FIG. 4 and FIG. It is a fingerprint detector that adapts the sensing device 102 to include 10 conductors. Therefore, the fingerprint detector can more comprehensively detect the sliding operation of the user's finger on the fingerprint detector in all directions.

In addition, it should be noted that, in the embodiment of the present invention, in addition to the circuit structure exemplified in this embodiment, other circuit structures that can realize the same function are also included in the protection scope of the technical solution of the present invention. Inside.

To sum up, in the embodiment of the present invention, in addition to the fingerprint recognition module, the fingerprint detector also includes a sensing device that can detect the sliding operation of the user's finger on the fingerprint detector, and through the The detection circuit connected to the device can accurately analyze the sliding direction of the user's finger, so that the electronic device provided with the fingerprint detector can respond more accurately according to the sliding direction of the user's finger.

Further, in an embodiment of the present invention, an electronic device is also provided, the electronic device includes a casing, a processor, and a fingerprint detector, wherein,

The processor is arranged in the housing, and the processor is connected to the fingerprint detector, where the fingerprint detector is the above-mentioned fingerprint detector. The specific structure and implementation principle of the fingerprint detector have been described in detail in the above-mentioned embodiments, and will not be repeated here.

While preferred embodiments of the present application have been described, additional changes and modifications to these embodiments can be made by those of ordinary skill in the art once the basic inventive concept is appreciated. Therefore, the appended claims are intended to be construed to cover the preferred embodiment and all changes and modifications which fall within the scope of the application.

Obviously, those skilled in the art can make various changes and modifications to the application without departing from the spirit and scope of the application. In this way, if these modifications and variations of the present application fall within the scope of the claims of the present application and their equivalent technologies, the present application is also intended to include these modifications and variations.

Claims (6)

1. A fingerprint detector, characterized in that, comprising: A fingerprint identification module, used to identify the user's fingerprint; A sensor comprising at least two conductors, each of the at least two conductors is respectively connected to a drive circuit that provides a drive signal, and the at least two conductors are arranged on the edge of the fingerprint recognition module; The detection circuit is respectively connected with each conductor, and is used for detecting the signal to be processed on the conductor. 2. The fingerprint detector according to claim 1, wherein the detection device comprises four conductors, and the four conductors form a rectangle. 3. The fingerprint detector according to claim 1, wherein the detection circuit comprises: a data selector, connected to each conductor respectively, for selecting a signal to be processed detected on a conductor; A chopper-stabilized amplifier, configured to perform arithmetic processing on the signal to be processed output by the data selector, and output a first processed signal; A demodulation circuit, connected to the chopper-stabilized amplifier, for demodulating the first processed signal output by the chopper-stabilized amplifier, and outputting the demodulated second processed signal; A programmable gain amplifier, connected to the demodulation circuit, for performing gain processing on the second processed signal output by the demodulation circuit, and outputting a third processed signal; A digital-to-analog converter connected to the programmable gain amplifier, configured to perform analog-to-digital conversion processing on the third processed signal output by the programmable gain amplifier, and obtain a fourth processed signal; a filter, connected to the digital-analog converter, configured to filter the fourth processed signal output by the digital-analog converter, and obtain a fifth processed signal. 4. The fingerprint detector according to claim 3, wherein the chopper-stabilized amplifier comprises: a first switch, a second switch, a third switch, a fourth switch, a first capacitor, a second capacitor, a an integrator, a second integrator, wherein, One end of the first switch is connected to the input end of the first integrator, and the other end is connected to the data selector; One end of the second switch is connected to the input end of the second integrator, and the other end is connected to the data selector; After the third switch is connected in parallel with the first capacitor, both ends are respectively connected to the input terminal and the output terminal of the first integrator; After the fourth switch is connected in parallel with the second capacitor, both ends are respectively connected to the input terminal and the output terminal of the second integrator; The other input terminal of the first integrator is connected to the first power supply, and the output terminal is connected to the demodulation circuit; The other input terminal of the second integrator is connected to the second power supply, and the output terminal is connected to the demodulation circuit. 5. The fingerprint detector according to claim 3, wherein the demodulation circuit is specifically used to eliminate the DC component in the first processed signal output by the chopper-stabilized amplifier, and eliminate the DC component The first processed signal is demodulated, and the second processed signal is output. 6. An electronic device, characterized in that the electronic device comprises: case; a processor disposed in the housing; A fingerprint detector is connected with the processor, and the fingerprint detector is the fingerprint detector according to any one of claims 1-5.