KR101967893B1 - Apparatus for sensing fingerprint on panel - Google Patents

Apparatus for sensing fingerprint on panel Download PDF

Info

Publication number
KR101967893B1
KR101967893B1 KR1020150036833A KR20150036833A KR101967893B1 KR 101967893 B1 KR101967893 B1 KR 101967893B1 KR 1020150036833 A KR1020150036833 A KR 1020150036833A KR 20150036833 A KR20150036833 A KR 20150036833A KR 101967893 B1 KR101967893 B1 KR 101967893B1
Authority
KR
South Korea
Prior art keywords
fingerprint recognition
sensing
circuit
resolution
resolution fingerprint
Prior art date
Application number
KR1020150036833A
Other languages
Korean (ko)
Other versions
KR20160111762A (en
Inventor
김재준
변영재
엄원진
김성우
Original Assignee
울산과학기술원
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by 울산과학기술원 filed Critical 울산과학기술원
Priority to KR1020150036833A priority Critical patent/KR101967893B1/en
Publication of KR20160111762A publication Critical patent/KR20160111762A/en
Application granted granted Critical
Publication of KR101967893B1 publication Critical patent/KR101967893B1/en

Links

Images

Classifications

    • G06K9/0002—
    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03K—PULSE TECHNIQUE
    • H03K17/00—Electronic switching or gating, i.e. not by contact-making and –breaking
    • H03K17/94—Electronic switching or gating, i.e. not by contact-making and –breaking characterised by the way in which the control signals are generated
    • H03K17/945—Proximity switches
    • H03K17/955—Proximity switches using a capacitive detector

Landscapes

  • Image Input (AREA)
  • Measurement Of Length, Angles, Or The Like Using Electric Or Magnetic Means (AREA)

Abstract

A multi-channel switch circuit in which at least one switch is turned on or off based on output pulses, a high-resolution fingerprint recognition panel in which a finger or a finger touches a floor, A high-resolution fingerprint recognition sensing circuit for sensing a fingerprint touched by a high-resolution fingerprint recognition panel, and a central processing unit for outputting the fingerprint sensed by the high-resolution fingerprint recognition sensing circuit.

Description

FIELD OF THE INVENTION [0001] The present invention relates to a fingerprint recognition apparatus,

The present invention relates to a high-resolution fingerprint recognition apparatus, and more particularly, to a high-resolution fingerprint recognition apparatus capable of detecting fingerprints of a plurality of pixels even in an amplifier by controlling a switch due to a clock.

Recently, as fingerprint recognition technology has developed, fingerprint recognition function has been used in various terminals, and many researches and developments have been made for fingerprint recognition technology which is accurate and low in power consumption.

At this time, a fingerprint is recognized using a touch panel. In this regard, Korean Patent Laid-Open Publication No. 2011-0095565 (published on Aug. 25, 2011) discloses a method for storing position data and fingerprint data received from a sensor grid panel and a sensor grid panel.

However, since a plurality of amplifiers are required to sense a plurality of pixels by using a single output amplifier, power consumption is increased, and the amount of change in capacitance is digitized using an analog digital converter, And the power consumption due to the use of the analog-to-digital converter is increased.

Korean Patent Laid-Open Publication No. 2011-0095565 (published on Aug. 25, 2011) discloses a transparent panel user input device, a user fingerprint recognition method, and a user touch recognition method using a sensor grid method capable of fingerprint recognition or multi-touch.

In an embodiment of the present invention, the process of converting the change of the capacitor to the voltage and then the digitization through the ADC is removed, and the changed capacitor is compared with the reference capacitor to output the digital signal directly. However, since it detects by shifting by one pixel, it can have 1 port accuracy and it is possible to add a balancing switch to reduce the mismatch caused by the parasitic capacitor in the switch. . It should be understood, however, that the technical scope of the present invention is not limited to the above-described technical problems, and other technical problems may exist.

As a technical means for achieving the above-mentioned technical object, an embodiment of the present invention is a multi-channel switch circuit in which at least one switch is turned on or off based on an output pulse, A high-resolution fingerprint recognition panel for sensing a fingerprint touched by a high-resolution fingerprint recognition panel under the control of a control circuit, and a central processing unit for outputting fingerprints sensed by the high-resolution fingerprint recognition detection circuit.

According to any one of the above-mentioned objects of the present invention, by using a fully differential amplifier, it is possible to detect a plurality of pixels even with one amplifier. By outputting only the difference value between the sense capacitor and the reference capacitor, It can reduce power consumption. It works with 2 ports, but it can not only have 1 port resolution, but also can reduce high-resolution fingerprint recognition by reducing mismatch by parasitic capacitor to balancing switch.

FIG. 1 is a block diagram illustrating a high-resolution fingerprint recognition apparatus according to an exemplary embodiment of the present invention. Referring to FIG.
FIG. 2 is a diagram for explaining a method of detecting a fingerprint in the high-resolution fingerprint recognition apparatus shown in FIG.
3 is a diagram for explaining a method of outputting a control signal in the control circuit shown in Fig.
FIG. 4 is a circuit diagram showing an equivalent circuit of a parasitic capacitance generated in the high-resolution fingerprint recognition apparatus shown in FIG.
FIG. 5 is a circuit diagram showing a circuit and an equivalent circuit capable of sensing three pixels in one amplifier of the high-resolution fingerprint recognition apparatus shown in FIG.
FIG. 6 is a circuit diagram illustrating a balancing switch for eliminating parasitic capacitance generated in the high-resolution fingerprint recognition apparatus shown in FIG. 1. Referring to FIG.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings, which will be readily apparent to those skilled in the art. The present invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. In order to clearly illustrate the present invention, parts not related to the description are omitted, and similar parts are denoted by like reference characters throughout the specification.

Throughout the specification, when a part is referred to as being "connected" to another part, it includes not only "directly connected" but also "electrically connected" with another part in between . Also, when an element is referred to as " including " an element, it is to be understood that the element may include other elements as well as other elements, And does not preclude the presence or addition of one or more other features, integers, steps, operations, components, parts, or combinations thereof.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 is a block diagram illustrating a high-resolution fingerprint recognition apparatus according to an exemplary embodiment of the present invention. Referring to FIG. 1, the high-resolution fingerprint recognition device 1 includes a control circuit 100, a multi-channel switch circuit 200, a high-resolution fingerprint recognition panel 300, a high-resolution fingerprint recognition detection circuit 400, (500).

The high-resolution fingerprint recognition apparatus 1 according to an embodiment of the present invention can recognize 100 or more pixels using only one amplifier using the control circuit 100. [ Also, in the high-resolution fingerprint recognition device 1, the high-resolution fingerprint recognition circuit 400 uses a fully differential amplifier so that the output voltage is largely changed even when a small input signal changes, . Further, since the high-resolution fingerprint recognition apparatus 1 according to the embodiment of the present invention only defines the boundary value of the fingerprint pattern in order to recognize the pattern of the fingerprint, that is, only the part of the fingerprint that is in contact with the panel Instead of using a high-performance analog-to-digital converter (ADC) that consumes a lot of power and requires a lot of time to operate, it can be configured to compare the capacitance of a cell with a reference capacitance using a comparator . In this case, the comparator may be implemented using a dynamic comparator to operate only when a signal is input, thereby reducing power consumption. Here, the high-resolution fingerprint recognition apparatus 1 according to an embodiment of the present invention uses a fully differential amplifier as an integrator.

In addition, the high-resolution fingerprint recognition device 1 according to an embodiment of the present invention is a fingerprint recognition method suitable for a self-capacitor method. Even if only one noise is inputted, ) Is stronger against external noise than the mutual-cap scheme that is affected. The high-resolution fingerprint recognition sensing circuit 400 of the high-resolution fingerprint sensing device 1 according to an embodiment of the present invention is constructed using a fully differential amplifier and the control circuit 100 controls the high- Channel switch circuit 200 is turned on while moving the rows and columns of the fingerprint recognition circuit 400. Thus, one full differential amplifier included in the high-resolution fingerprint recognition detection circuit 400 can recognize 100 pixels. In addition, the high-resolution fingerprint recognition apparatus 1 according to an embodiment of the present invention is configured to additionally implement the balancing capacitor 600 to cancel the reference capacitance and remove the parasitic capacitance.

The characteristics of the high-resolution fingerprint recognition device 1 and the conventional sensing devices Type 1 to Type 4 according to an embodiment of the present invention are shown in Table 1 below.

Figure 112015026059439-pat00001

The configuration of the high-resolution fingerprint recognition apparatus 1 according to an embodiment of the present invention having the above-described characteristics is as follows.

The control circuit 100 may output a pulse every predetermined period to turn on a switch or a channel. Here, the control circuit 100 may include Low Logic and High Logic, and each logic included in the control circuit 100 may control the operation of the Serial Input Parallel Output (SIPO) Can be performed. At this time, the low logic and the high logic can be synchronized by using the final output signal of the low logic as the high logic clock signal. The control circuit 100 may be constituted by a shift register. Also, the control circuit 100 may detect the plurality of pixels included in the high-resolution fingerprint recognition panel 300 by the high-resolution sensing circuit 400 using the multi-channel switch circuit 200. [

In the multi-channel switch circuit 200, at least one switch may be turned on or off based on the output pulse.

The high-resolution fingerprint recognition panel 300 may be a panel in which a finger or a floor of the fingerprint is contacted. Here, the high-resolution fingerprint recognition panel 300 may include at least one channel. In addition, a port number is assigned to each channel of at least one channel, and the high-resolution fingerprint recognition detection circuit 400 senses a pixel having a resolution of one port by sequentially moving pixels for each pair of port numbers .

The high-resolution fingerprint recognition circuit 400 can sense a fingerprint touched by the high-resolution fingerprint recognition panel 300 under the control of the control circuit 100. Here, the high-resolution fingerprint recognition detection circuit 400 may include a fully differential amplifier. At this time, the high-resolution fingerprint detection circuit 400 may further include at least one reference capacitor connected to an upper node of the fully differential amplifier 400 and at least one sense capacitor connected to a lower node of the fully differential amplifier 400 have.

At least one of the reference capacitors may include a sensing value sensed by at least one sensing capacitor in the case where the fingerprint is touched to the high resolution fingerprint recognition panel 300 and a sensing value sensed by the sensing capacitor when the fingerprint floor is in contact with the high resolution fingerprint recognition panel 300 May be determined as a value between sensing values sensed in at least one sensing capacitor.

The central processing unit 500 can output the fingerprint sensed by the high-resolution fingerprint recognition sensing circuit 400. [

The balancing switch 600 is capable of removing the parasitic capacitors generated by the multi-channel switch circuit 200.

The driving principle and operation of the high-resolution fingerprint recognition apparatus 1 having the above-described configuration according to an embodiment of the present invention will be described below. However, the driving principle and operation of the present invention are not limited to the following embodiment.

FIG. 2 is a view for explaining a fingerprint sensing method in the high-resolution fingerprint recognition apparatus shown in FIG. 1, FIG. 3 is a view for explaining a method of outputting a control signal in the control circuit shown in FIG. 1, FIG. 4 is a circuit diagram showing an equivalent circuit of a parasitic capacitance generated in the high-resolution fingerprint recognition apparatus shown in FIG. 1, FIG. 5 is a circuit diagram showing an example in which one pixel of the high- FIG. 6 is a circuit diagram showing a balancing switch for eliminating parasitic capacitance generated in the high-resolution fingerprint recognition apparatus shown in FIG. 1. FIG.

Referring to FIG. 2, the high-resolution fingerprint recognition panel 300 may include 10 channels of 10 pixels each, and a total of 100 pixels. This can be changed according to the size of the high-resolution fingerprint recognition panel 300, and thus is not limited thereto.

Here, the high-resolution fingerprint recognition circuit 400 may be configured as a fully differential amplifier, and a reference capacitor may be connected to a lower node and a sense capacitor may be connected to an upper node to sense the reference capacitor and the sense capacitor. When the value of the sense capacitor is larger than the reference capacitor, the output of the high-resolution fingerprint recognition sensing circuit 400 is 1, and when the value of the sense capacitor is smaller than the reference capacitor, 0 < / RTI >

(A) is a case in which the floor of the fingerprint is in contact with the high-resolution fingerprint recognition panel 300, (b) is a case in which the fingerprint of the fingerprint is in the high-resolution fingerprint recognition panel 300 As shown in Fig. Here, the reference capacitor can use the value between the sensing capacitors when the valleys of the fingerprint touch the high-resolution fingerprint recognition panel 300 and when the floor of the fingerprint touches the high resolution fingerprint recognition panel 300.

In this case, numbers from p <0> to p <9> can be assigned to each pixel from the left end in one channel of the high-resolution fingerprint recognition panel 300. At this time, pixels are grouped in the order of p <0> -p <1> /p <1> -p <2> /p <2> -p <3> /. So that it can be sensed. That is, it is a two-port system, but since it moves by one pixel, it can have a resolution of one port.

In addition, since the high-resolution fingerprint recognition circuit 400 performs the fingerprint recognition using the fully differential amplifier, it can operate at high speed and low power, and can accurately output the boundary value.

Referring to FIG. 3, the control circuit 100 may use two types of logic, low logic and high logic. (a) Each logic may be implemented in the form of a Serial Input Parallel Output (SIPO) controlled by one clock signal and outputting the received signal sequentially to the next stage each time the clock rises. At this time, (b) shows a graph of the output signal of the shift register. (c) Low logic is 1

Figure 112015026059439-pat00002
And a shift register for outputting two pulses. Each signal of the low logic can turn on the switches of the multi-channel switch circuit 200 by two and move the turned-on switch by one node. (d) and the high logic is 11
Figure 112015026059439-pat00003
And a shift register that outputs 10 pulses in total. Here, the high logic serves to turn on each channel of the high-resolution fingerprint recognition panel 300 sequentially.

Both logic can be synchronized by using the last output signal of the low logic as the clock of the high logic, so that two logic can be controlled simultaneously with one clock. As described above, the control circuit 100 can detect 100 pixels and can reduce the power consumption of the entire system by reducing the configuration of the amplifier consuming a lot of power.

Referring to FIG. 4, in order to detect a plurality of pixels by one amplifier using the control circuit 100, each of the pixels must be connected to the amplifier through a multi-channel switch circuit 200. At this time, a result different from that expected by the parasitic capacitors existing in the multichannel switch circuit 200 may be output. In the case of fingerprint recognition, a range of the capacitors to be sensed is narrow, so that errors due to the parasitic capacitors can be large . Therefore, a method for compensating for this is required.

(a) shows a case where at least one switch included in the multi-channel switch circuit 200 is connected to a capacitor in a turned-on state, and the right side of (a) Is an equivalent circuit assuming one impedance as a turn-on state. At this time, since at least one switch includes not only a capacitor but also a resistor, it is represented by an impedance.

(b), at least one switch included in the multi-channel switch circuit 200 is turned off. Since both ends are not in a connected state, they have the same impedance regardless of the capacitors, so that an equivalent circuit can be expressed only by impedance except capacitors.

Referring to Figure 5 (a), a circuit for sensing three pixels with one amplifier is shown. At this time, a reference capacitor is connected to the lower node of the amplifier, and a sense capacitor of three pixels is connected to the upper node together with the switch. Only one of the three switches is turned on, and the other two switches are always turned off. Therefore, the circuit of (a) can be expressed by an equivalent circuit as shown in (b). At this time, a mismatch may occur in the process of comparing the sense capacitor and the reference capacitor.

Accordingly, referring to FIG. 6, (a) adds a balancing switch 600 to the circuit of (a) of FIG. 5 so that a mismatch can be removed. Referring to FIG. 6A, the reference capacitor can always connect the switches in a turned-on state in series, and connect the two switches in a turned-off state in parallel at all times. Here, two switches connected in parallel in the always-off state may be the balancing switch 600. [ 6 (b) is an equivalent circuit of (a). According to the circuit to which the balancing switch 600 of Fig. 6 is added, since the effects due to the switches of the upper node and the lower node are canceled, the reference capacitor and the sense capacitor can be accurately compared.

The high-resolution fingerprint recognition device 1 according to the embodiment of the present invention can reduce power consumption by eliminating the ADC that occupies the largest power consumption in the fingerprint recognition and eliminating the ADC. In addition, the high-resolution fingerprint recognition apparatus 1 according to the embodiment of the present invention eliminates the process of converting the change of the capacitor to the voltage and then digitizing the change through the ADC, and comparing the changed capacitor with the reference capacitor Since the digital signal is directly output, power consumption can be reduced in this process. In addition, the high-resolution fingerprint recognition apparatus 1 according to the embodiment of the present invention can perform a one-port accuracy because it uses a two-port scheme but shifts by one pixel to detect it. In addition, the high-resolution fingerprint recognition apparatus 1 according to an embodiment of the present invention can reduce a mismatch caused by a parasitic capacitor generated in a switch by adding a balancing switch.

It will be understood by those skilled in the art that the foregoing description of the present invention is for illustrative purposes only and that those of ordinary skill in the art can readily understand that various changes and modifications may be made without departing from the spirit or essential characteristics of the present invention. will be. It is therefore to be understood that the above-described embodiments are illustrative in all aspects and not restrictive. For example, each component described as a single entity may be distributed and implemented, and components described as being distributed may also be implemented in a combined form.

The scope of the present invention is defined by the appended claims rather than the detailed description and all changes or modifications derived from the meaning and scope of the claims and their equivalents are to be construed as being included within the scope of the present invention do.

Claims (10)

A control circuit for outputting a pulse every predetermined period to turn on at least one switch or at least one channel;
A multi-channel switch circuit including the at least one switch, wherein the at least one switch is turned on or off based on the output pulse;
A high-resolution fingerprint recognition panel in contact with a floor or a floor of a fingerprint;
A high-resolution fingerprint recognition sensing circuit for sensing a fingerprint touched by the high-resolution fingerprint recognition panel under the control of the control circuit;
And a central processing unit for outputting the fingerprint detected by the high-resolution fingerprint recognition circuit,
Wherein the high-resolution fingerprint recognition panel includes the at least one channel to which a port number is assigned for each pixel, is connected to the high-resolution fingerprint recognition detection circuit through the multi-
The high-resolution fingerprint recognition circuit performs group sensing while sequentially moving reference pixels by one port number, and the group sensing is to sense n (n is a natural number of 2 or more) pixels including the reference pixel ,
Wherein the high-resolution fingerprint recognition sensing circuit comprises: a fully differential amplifier; At least one reference capacitor coupled to an upper node of the amplifier; And at least one sense capacitor coupled to a lower node of the amplifier, wherein the at least one sense capacitor value is different from the at least one reference capacitor value, ,
Wherein the at least one reference capacitor comprises a sensing value sensed by the at least one sensing capacitor when the fingerprint bone touches the high resolution fingerprint recognition panel and a sensing value sensed by the at least one sensing capacitor when the fingerprint floor is in contact with the high resolution fingerprint recognition panel. And a sensing value sensed by a sensing capacitor of the sensing device.
delete delete delete delete The method according to claim 1,
Wherein the control circuit includes Low Logic and High Logic,
Wherein each logic included in the control circuit performs an operation of a Serial Input Parallel Output (SIPO).
The method according to claim 6,
Wherein the low logic and the high logic are synchronized by using a final output signal of the low logic as a clock signal of the high logic.
The method according to claim 1,
Wherein the control circuit is constituted by a shift register.
The method according to claim 1,
Wherein the control circuit causes the high-resolution fingerprint recognition circuit to detect a plurality of pixels included in the high-resolution fingerprint recognition panel using the multi-channel switch circuit.
The method according to claim 1,
And a balancing switch for removing the parasitic capacitors generated by the multi-channel switch circuit.
KR1020150036833A 2015-03-17 2015-03-17 Apparatus for sensing fingerprint on panel KR101967893B1 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
KR1020150036833A KR101967893B1 (en) 2015-03-17 2015-03-17 Apparatus for sensing fingerprint on panel

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
KR1020150036833A KR101967893B1 (en) 2015-03-17 2015-03-17 Apparatus for sensing fingerprint on panel

Publications (2)

Publication Number Publication Date
KR20160111762A KR20160111762A (en) 2016-09-27
KR101967893B1 true KR101967893B1 (en) 2019-04-10

Family

ID=57100930

Family Applications (1)

Application Number Title Priority Date Filing Date
KR1020150036833A KR101967893B1 (en) 2015-03-17 2015-03-17 Apparatus for sensing fingerprint on panel

Country Status (1)

Country Link
KR (1) KR101967893B1 (en)

Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR100991130B1 (en) * 2010-03-19 2010-11-02 주식회사 에임즈 Apparatus for driving a touch panel

Family Cites Families (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US8791792B2 (en) * 2010-01-15 2014-07-29 Idex Asa Electronic imager using an impedance sensor grid array mounted on or about a switch and method of making
KR101136153B1 (en) 2010-02-19 2012-04-16 성균관대학교산학협력단 User input device, method for recognizing user finger prints, and method for recognizing user touches using a transparent sensor grid panel which is able to recognize finger prints or mult-touch
KR20120031651A (en) * 2010-09-27 2012-04-04 엘지디스플레이 주식회사 Display device and method of controlling clock signal thereof

Patent Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR100991130B1 (en) * 2010-03-19 2010-11-02 주식회사 에임즈 Apparatus for driving a touch panel

Also Published As

Publication number Publication date
KR20160111762A (en) 2016-09-27

Similar Documents

Publication Publication Date Title
KR101239844B1 (en) apparatus for sensing a touch
US11481066B2 (en) Providing a baseline capacitance for a capacitance sensing channel
CN102799302B (en) Input device and touch event processing method
CN108141212B (en) Capacitance measuring device with reduced noise
KR101514533B1 (en) Touch sensing apparatus and method capable of supporting hover sensing
US8321174B1 (en) System and method to measure capacitance of capacitive sensor array
TWI544393B (en) Capacitive touch sensing system
US8514191B2 (en) Touch panel sensing circuit
US8487908B2 (en) Detector circuit and detect method of a capacitive touch panel
US20110068810A1 (en) Sensing method and driving circuit of capacitive touch screen
US20130215053A1 (en) Anti-interference driving method of touch panel and touch panel device using the same
US9110544B2 (en) Touch sensing method and touch sensing apparatus of charge distribution type
CN105474147A (en) Capacitive touch system
US20180120355A1 (en) Multiple Channel Capacitive Voltage Divider Scanning Method And Apparatus
CN104346016A (en) Touch detection circuit, touch detection method, and electronic apparatus
US9606671B2 (en) Capacitive sensing device capable of eliminating influence from mutual capacitance and operating method thereof
US20180211080A1 (en) Fingerprint Identification Circuit, Touch Apparatus and Fingerprint Identification Method
US20130063388A1 (en) Capacitive touch screen controller implementing a sensing method for improved noise immunity
US11592936B2 (en) Capacitive touch device with high sensitivity and low power consumption
JP5814707B2 (en) Capacitance detection circuit for touch panel, capacity detection method, touch panel input device using the same, and electronic device
US9753583B2 (en) Method of scanning touch panel and touch integrated circuit for performing the same
US20160132147A1 (en) Capacitive touch system and frequency selection method thereof
KR101967889B1 (en) Apparatus for sensing fingerprint on panel
KR101967893B1 (en) Apparatus for sensing fingerprint on panel
EP3862857A1 (en) Capacitance measurement circuit, touch-control chip and electronic device

Legal Events

Date Code Title Description
A201 Request for examination
N231 Notification of change of applicant
E902 Notification of reason for refusal
AMND Amendment
E601 Decision to refuse application
AMND Amendment
X701 Decision to grant (after re-examination)
GRNT Written decision to grant