KR20210015043A - Display apparatus with a frequency variable fingerprint sensor - Google Patents

Abstract

An objective of the present invention is to provide a display device with a frequency variable fingerprint sensor to determine a thickness of a cover through touch sensing and vary a frequency of ultrasonic waves used for fingerprint sensing according to a determination result. The display device comprises: a display panel; a touch panel; a fingerprint sensor; a fingerprint sensor driver; a touch driver; and a control unit.

Description

A display device equipped with a frequency variable fingerprint sensor {DISPLAY APPARATUS WITH A FREQUENCY VARIABLE FINGERPRINT SENSOR}

The present invention relates to a display device equipped with a fingerprint sensor.

The fingerprint sensor is a sensor that senses a person's fingerprint. Fingerprint sensors are generally used for locking devices such as door locks, but recently they are also used for releasing the sleep mode of electronic devices such as smart phones, and are also used as authentication means for various applications provided in smart phones.

The fingerprint sensor can be classified into an ultrasonic type, an infrared type, and a capacitive type, depending on the operating principle.

In particular, a fingerprint sensor using an ultrasonic method recognizes a fingerprint by using a difference in voltages generated when ultrasonic waves generated from a piezoelectric element are reflected from a valley and a ridge of the fingerprint.

In general, a user who purchases a display device attaches a protective film to the display window to protect the display window of the display device, and may change the protective film used for a long time with the display device into a new protective film.

In this case, depending on the thickness of the protective film, the size of the ultrasonic wave generated from the piezoelectric element reaching the fingerprint may be reduced, and accordingly, the user's fingerprint may not be normally sensed.

An object of the present invention proposed to solve the above-described problem is to determine the thickness of the cover through touch sensing, and to vary the frequency of ultrasonic waves used for fingerprint sensing according to the determination result, a frequency variable fingerprint sensor is provided. It is to provide a display device.

A display device equipped with a frequency variable fingerprint sensor according to the present invention for achieving the above-described technical problem includes a display panel including a cover exposed to the outside, a touch panel detecting a touch through the cover, and a fingerprint of a finger. A fingerprint sensor equipped with fingerprint pixels that perform a function as a basic unit to recognize, a fingerprint sensor driver that drives the fingerprint sensor to perform fingerprint sensing, a touch driver that drives the touch panel to perform touch sensing, and the fingerprint sensor And a driver and a controller for controlling the touch driver. The touch driver determines the thickness of the cover through the touch sensing, and the fingerprint sensor driver varies the frequency of ultrasonic waves used for the fingerprint sensing according to the thickness of the cover.

According to the present invention, even if protective films of various thicknesses are attached to the display device according to the user's selection, the fingerprint sensing sensitivity can be kept constant.

1 is an exemplary view showing the configuration of a display device equipped with a frequency variable fingerprint sensor according to the present invention.
2 is an exemplary view showing the configuration of a control unit applied to a display device equipped with a frequency variable fingerprint sensor according to the present invention.
3 is an exemplary view showing the structure of a fingerprint sensor applied to a display device equipped with a frequency variable fingerprint sensor according to the present invention.
4 is another exemplary view showing the structure of a fingerprint sensor applied to a display device equipped with a frequency variable fingerprint sensor according to the present invention.
5A is an exemplary view for explaining the operating principle of a fingerprint sensor applied to a display device equipped with a frequency variable fingerprint sensor according to the present invention.
5B is another exemplary view for explaining the operating principle of a fingerprint sensor applied to a display device equipped with a frequency variable fingerprint sensor according to the present invention.
6 is an exemplary view showing the configuration of a fingerprint sensor applied to a display device equipped with a frequency variable fingerprint sensor according to the present invention.
7 is an exemplary view showing the configuration of a fingerprint sensor and a fingerprint sensor driver for explaining a method of driving a display device equipped with a frequency variable fingerprint sensor according to the present invention.
8 is an exemplary view showing waveforms of signals generated by a fingerprint sensor driver to drive the fingerprint sensor shown in FIG. 7;
9 is another exemplary view showing a configuration of a fingerprint sensor and a fingerprint sensor driver for explaining a method of driving a display device equipped with a frequency variable fingerprint sensor according to the present invention.
10 is an exemplary view showing waveforms of signals generated by a fingerprint sensor driver to drive the fingerprint sensor shown in FIG. 9;
11 is a graph showing a change in size of a touch sensing signal according to a thickness of a cover in a display device equipped with a frequency variable fingerprint sensor according to the present invention.
12 is an exemplary view showing a change in sound pressure of ultrasonic waves according to a frequency change of ultrasonic waves in a display device equipped with a frequency variable fingerprint sensor according to the present invention.
13 is a graph showing characteristics of ultrasonic waves for each frequency in a display device equipped with a frequency variable fingerprint sensor according to the present invention.

Advantages and features of the present invention, and a method of achieving them will become apparent with reference to embodiments described below in detail together with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but will be implemented in a variety of different forms, only these embodiments are intended to complete the disclosure of the present invention, and those skilled in the art to which the present invention pertains. It is provided to fully inform the person of the scope of the invention, and the invention is only defined by the scope of the claims.

In the present specification, in adding reference numerals to elements of each drawing, it should be noted that only the same elements have the same number as possible, even if they are indicated on different drawings.

The shapes, sizes, ratios, angles, numbers, etc. disclosed in the drawings for explaining the embodiments of the present invention are exemplary, and the present invention is not limited to the illustrated matters. The same reference numerals refer to the same components throughout the specification. In addition, in describing the present invention, when it is determined that a detailed description of related known technologies may unnecessarily obscure the subject matter of the present invention, the detailed description thereof will be omitted. When'include','have','consists of' and the like mentioned in the present specification are used, other parts may be added unless'only' is used. In the case of expressing the constituent elements in the singular, it includes the case of including the plural unless specifically stated otherwise.

In interpreting the constituent elements, it is interpreted as including an error range even if there is no explicit description.

In the case of a description of the positional relationship, for example, if the positional relationship of two parts is described as'upper','upper of','lower of','next to','right' Or, unless'direct' is used, one or more other parts may be located between the two parts.

In the case of a description of a temporal relationship, for example, when a temporal predecessor relationship is described as'after','following','after','before', etc.,'right' or'direct' It may also include cases that are not continuous unless this is used.

The term “at least one” is to be understood as including all possible combinations from one or more related items. For example, the meaning of'at least one of the first item, the second item and the third item' is not only the first item, the second item, or the third item, but also the second item, the second item, and the third item. It means a combination of all items that can be presented from more than one.

First, second, etc. are used to describe various elements, but these elements are not limited by these terms. These terms are only used to distinguish one component from another component. Accordingly, the first component mentioned below may be a second component within the technical idea of the present invention.

Each of the features of the various embodiments of the present invention can be partially or entirely combined or combined with each other, technically various interlocking and driving are possible, and each of the embodiments can be implemented independently of each other or can be implemented together in a related relationship. May be.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 is an exemplary view showing the configuration of a display device equipped with a frequency variable fingerprint sensor according to the present invention, and FIG. 2 is an exemplary view showing the configuration of a control unit applied to a display device equipped with a frequency variable fingerprint sensor according to the present invention. to be.

A display device equipped with a frequency variable fingerprint sensor according to the present invention includes a display panel 100 displaying an image, a touch panel 800 sensing a user's touch, and the touch panel 800 as shown in FIG. 1. A touch driver 700 for driving a device, a gate driver 200 for supplying gate signals to the gate lines GL1 to GLg provided in the display panel 100, a function as a basic unit for recognizing a user's fingerprint The fingerprint sensor 500 provided with the fingerprint pixels 510 performing the operation, the fingerprint sensor driver 600 for driving the fingerprint sensor 500, and the data lines DL1 to DLd provided on the display panel. The data driver 300 for supplying data voltages and the input image data transmitted from the external system are converted into image data and transmitted to the data driver 300, and timing synchronization signals transmitted from the external system are converted into image data. And a controller 400 that generates a control signal for controlling the gate driver 200, the data driver 300, the touch driver 700, and the fingerprint sensor driver 600 by using the gate driver 200.

In the following, the components are sequentially described.

The display panel 100 may be a liquid crystal display panel including liquid crystal, an organic light emitting display panel including organic light emitting diodes, a light emitting display panel using inorganic light emitting devices, and various types of displays. Can be one of the panels.

The display panel 100 includes a display area 120 including pixels 110 displaying an image and a non-display area 130 surrounding the display area 120.

In the non-display area 130, the gate driver 200 for supplying gate signals to pixel driving circuits provided for each of the pixels 110 may be provided.

A display device equipped with a frequency-variable fingerprint sensor (hereinafter, simply referred to as a display device) according to the present invention includes a touch panel 800 used to determine the presence or absence of a touch and a touch position by a user. The touch panel may be integrally formed with the display panel 100, or may be manufactured independently of the display panel 100 and then attached to the display panel 100.

The touch panel may be manufactured using various methods such as a resistive method or a capacitive method. When the touch panel uses a capacitive method, the touch panel may be manufactured using a mutual method requiring touch driving electrodes and touch receiving electrodes. When the touch panel uses a capacitive method, the touch panel may be manufactured using a self-cap method requiring only a plurality of independently provided touch electrodes.

The touch driver 700 supplies a touch driving signal to the touch panel 800, and a location of the touch panel 800 at which a touch is made using the touch sensing signals received from the touch panel 800 (hereinafter, It generates information (hereinafter, simply referred to as touch position information) about the touch position.

The touch driver 700 may transmit the touch location information to the fingerprint sensor driver 600.

The gate driver 200 supplies gate signals to the pixel driving circuits.

The gate driver 200 is provided in the non-display area 130 and may be manufactured together with the pixel driving circuits when the pixel driving circuits are manufactured. That is, the gate driver 200 may be directly embedded in the display panel 100 by using a gate in panel (GIP) method. However, the gate driver 200 may be manufactured independently of the display panel 100 and then mounted on the non-display area 130.

The gate driver 200 supplies a gate-on signal to the gate lines GL1 to GLg provided in the display panel 100 by using the gate control signals GCS transmitted from the control unit 400. . A plurality of gate clocks may be included in the gate control signals GCS.

Here, the gate-on signal means a signal capable of turning on the transistors connected to the gate lines GL1 to GLg. A signal capable of turning off the transistor is referred to as a gate off signal. The gate-on signal and the gate-off signal are collectively referred to as a gate signal.

The data driver 300 converts the image data Data transmitted from the controller 400 into data voltages, and then supplies the data voltages to the data lines DL1 to DLd.

The control unit 400 controls gate control signals GCS for controlling driving of the gate driver 200 and the data driver 300 using timing synchronization signals TSS input from an external system. It generates data control signals (DCS) for control. In addition, the control unit 400 converts input image data (Ri, Gi, Bi) input from the external system into image data, and converts the image data into the data driver 300. send.

As described above, the display device equipped with a frequency variable fingerprint sensor according to the present invention supplies a touch drive signal to the touch panel 800 and uses the touch sensing signals received from the touch panel 800. A touch driver 700 for sensing whether a touch is present on the touch panel may be included, and the controller 400 may generate touch control signals for controlling the touch driver 700.

In addition, the control unit 400 may generate a fingerprint sensor control signal FCS for controlling the fingerprint sensor driver 600.

In order to perform the functions as described above, the control unit 400, as shown in FIG. 2, uses a timing synchronization signal (TSS) transmitted from the external system, and input image data transmitted from the external system. A data alignment unit 430 for rearranging the fields Ri, Gi, and Bi to supply the rearranged image data to the data driver 300, and the gate control signal GCS using the timing synchronization signals TSS And a control signal generator 420 for generating the data control signal DCS, the touch control signal, and the fingerprint sensor control signal FCS, the timing synchronization signal TSS transmitted from the external system and the input An input unit 410 that distributes image data (Ri, Gi, Bi) to the data alignment unit 430 and the control signal generation unit 420, and the image data generated by the data alignment unit and the control And an output unit 440 for outputting the control signals generated by the signal generation unit to the data driver 300 or the gate driver 200 or the fingerprint sensor driver 600 or the touch driver 700. I can.

In addition, the controller 400 includes information necessary for controlling the gate driver 200, the data driver 300, the fingerprint sensor driver 600, and the touch driver 700, and the input image data Ri , Gi, Bi) and the image data (Data) may further include a storage unit 450 for storing at least one. However, the storage unit 450 may be configured independently from the control unit 400.

The fingerprint sensor 500 includes a driving electrode unit for generating ultrasonic waves, receiving electrodes for receiving ultrasonic waves reflected from a fingerprint of a finger, and a piezoelectric material disposed between the driving electrode unit and the receiving electrodes. The piezoelectric material refers to a material exhibiting a piezoelectric effect, and means, for example, a material such as quartz, Rochelle salt, barium titanate, and the like.

The fingerprint sensor 500 is provided with the fingerprint pixels 510 used as a basic unit of fingerprint recognition.

The fingerprint sensor 500 includes sensing gate lines connected to transistors provided in the fingerprint pixels 510.

The fingerprint sensor 500 may be provided in an area corresponding to a portion of the display area 120, but may be formed to have the same size as the display area 120.

The fingerprint sensor driver 600 supplies driving signals to the driving electrode unit and sensing gate signals to the sensing gate lines.

The fingerprint sensor driver 600 includes a driving unit 610 for driving the driving electrode unit and a fingerprint recognition unit 620 for recognizing a fingerprint using sensing signals received from the fingerprint sensor 500. In addition, the fingerprint sensor driver 600 includes a power supply unit 640 for supplying power required to the driving unit 610 and the fingerprint recognition unit 620, and a fingerprint input by a user (hereinafter, simply referred to as a reference fingerprint). ) May further include a storage unit 630 for storing.

The power supply unit 640 may be configured outside the fingerprint sensor driver 600 and independently of the fingerprint sensor driver 600.

The configuration and functions of the fingerprint sensor 500 and the fingerprint sensor driver 600 will be described in detail below with reference to the drawings.

3 is an exemplary view showing the structure of a fingerprint sensor applied to a display device equipped with a frequency variable fingerprint sensor according to the present invention, and FIG. 4 is a fingerprint sensor applied to a display device equipped with a frequency variable fingerprint sensor according to the present invention. It is another exemplary view showing the structure of.

The fingerprint sensor 500 applied to the present invention, as shown in FIGS. 3 and 4, includes a base substrate 520 and transistors provided in the fingerprint pixels 510, and includes the base substrate 520. The fingerprint pixel driving layer 530 provided, the receiving electrodes 540 provided on the fingerprint pixel driving layer 530 and provided for each of the fingerprint pixels 510, and a plate provided on the top of the receiving electrodes 540 And a piezoelectric material 550 in the form of a piezoelectric material 550 and a driving electrode part 560 provided on the piezoelectric material 550.

The base substrate 520 may be a glass substrate or a film formed of a synthetic resin.

The fingerprint pixel driving layer 530 includes transistors.

Each of the receiving electrodes 540 is connected to a gate of a first transistor provided in each of the fingerprint pixels 510. The first transistor is provided in the fingerprint pixel driving layer 530.

The receiving electrodes 540 are output from the driving electrode unit 560 to receive ultrasonic waves reflected from the user's finger, and a voltage generated by the received ultrasonic waves (hereinafter, simply referred to as ultrasonic voltage) is the first transistor. To the gate of.

The piezoelectric material 550 generates ultrasonic waves by voltages supplied to the driving electrode unit 560 and the receiving electrodes 540, and is reflected by the user's finger and received by the receiving electrode 540. It performs a function of generating the ultrasonic voltage by ultrasonic waves. As described above, as the piezoelectric material 550, quartz, Rochelle salt, barium titanate, or the like may be used.

The driving electrode unit 560 may include rod-shaped driving electrodes, as shown in FIG. 3. In this case, driving signals from the fingerprint sensor driver 600 may be supplied to the driving electrodes through various methods.

However, the driving electrode unit 560 may be configured as one driving electrode having a plate shape, as shown in FIG. 4.

5A is an exemplary diagram for explaining the operating principle of a fingerprint sensor applied to a display device equipped with a frequency variable fingerprint sensor according to the present invention.

In the fingerprint sensor 500, as described above, the fingerprint pixel driving layer 530 is provided on the base substrate 520, and the receiving electrode 540 is provided on the fingerprint pixel driving layer 530. Are provided, the piezoelectric material 550 is provided on the receiving electrodes 540, and the driving electrode part 560 is provided on the piezoelectric material 550.

In this case, among both surfaces of the base substrate 520 constituting the fingerprint sensor 500, a second surface opposite to the first surface on which the fingerprint pixel driving layer 530 is formed is the display panel 100 The image is adhered to the first surface 111 of the display panel 100 and outputs an image through the second surface 112 opposite to the first surface 111 of both surfaces of the display panel 100. The user's finger for fingerprint recognition is in contact with the second surface 112 of the display panel 100.

As described above, the display panel 100 may be a liquid crystal display panel, an organic light-emitting display panel, a light-emitting display panel using an inorganic light-emitting device, and other various types of display panels. Can be one.

In addition, the display panel 100 is provided with a touch panel 800 for sensing a touch position by a user. In this case, the touch panel 800 may be integrally formed with the display panel 100 or may be attached to the display panel 100. In addition, the touch panel may be configured using various methods such as a self cap method and a mutual method.

When the fingerprint sensor driver 600 supplies a driving signal to the driving electrode unit 560, ultrasonic waves are generated from the piezoelectric material 550, and the ultrasonic waves are, as shown in FIG. 5, the base substrate ( It is transmitted to the outside of the display panel 100 through 520 and the display panel 100.

A fingerprint is formed on the user's finger 20, and the fingerprint includes valleys 21 and ridges 22. There is a height difference between the valleys 21 and the floors 22, and the valleys 21 and the floors 22 are arranged with an inclined surface therebetween.

The receiving electrode 540 is output from the fingerprint sensor 500 and generated by the ultrasonic voltage generated from the receiving electrode 540 by the ultrasonic wave reflected from the valley 21 and the ultrasonic wave reflected from the floor 22. The ultrasonic voltages generated from have different values.

Accordingly, the fingerprint sensor driver 600 may recognize a fingerprint using the ultrasonic voltage generated through the receiving electrode 540.

In this case, the ultrasonic waves generated at the first point A of the fingerprint sensor 500 travel only in a direction perpendicular to the second surface 112 of the display panel 100 and then the second surface 112 It is not reflected only in the direction perpendicular to ). That is, the ultrasonic waves generated at the first point A can travel in various directions inclined with the second surface 112 as shown in FIG. 5A, and thus, the second surface 112 and the The receiving electrode 540 may be reached through various inclined directions.

Therefore, the ultrasonic waves received by the receiving electrode 540 corresponding to the first point A are generated not only at the first point A, but also at points other than the first point A. Ultrasound can also be included. In this case, the period during which the reflected ultrasound generated at the first point A is received, and the ultrasound generated at points other than the first point A and received at the first point A is received. The period is different.

The present invention can recognize a fingerprint using the difference in period as described above.

5B is another exemplary diagram for explaining the operating principle of a fingerprint sensor applied to a display device equipped with a frequency variable fingerprint sensor according to the present invention.

As described above, the fingerprint sensor 500 is attached to the display panel 100, and the user's finger is in contact with the second surface 112 of the display panel 100.

In this case, the second surface 112 of the display panel 100 is one of both surfaces of the cover glass 150 constituting the display panel 100. Accordingly, the second surface 112 may be the second surface of the cover glass 150. A portion of the display panel 100 excluding the cover glass 150 is referred to as a panel unit 160. That is, the panel unit 160 is a part that substantially outputs an image.

In general, in a manufacturing process of a display device, the cover glass 150 is provided on the outermost side of the display panel 100, and the display device is sold to a user while the cover glass 150 is provided.

A user who purchases a display device equipped with the cover glass 150 may additionally purchase a protective film 190 in order to prevent damage to the cover glass, and then replace the protective film 190 in FIG. 5B. As shown, it is attached to the top surface of the cover glass 150.

In this case, by the protective film 190, the distance from the fingerprint sensor 500 to the user's finger is changed.

For example, as shown in FIG. 5A, it is assumed that the distance from the fingerprint sensor 500 to the second surface 112 of the display panel 100 in the absence of the protective film 190 is F. In this case, the distance from the fingerprint sensor 500 to the top surface 191 of the protective film 190 when the protective film 190 is present is F+X as shown in FIG. 5B. Here, X is the thickness of the protective film 190.

The ultrasonic waves generated by the fingerprint sensor 500 are set to a specific frequency in the manufacturing step of the display device. In this case, the specific frequency is optimized in the display panel without the protective film 190, as shown in FIG. 5A.

For example, the magnitude of the ultrasound waves on the second surface 112 of the display panel or on the user's finger surface may be changed according to the frequency of the ultrasound waves. As the magnitude of the ultrasonic waves on the second surface 112 or the user's finger surface increases, the ultrasonic waves reflected from the second surface 112 or the user's finger surface and received from the receiving electrode 520 (hereinafter, simply The size of (referred to as received ultrasound) increases, and thus, fingerprint sensing sensitivity may be improved.

The specific frequency is set in consideration of a distance from the fingerprint sensor 500 to the second surface 112 of the display panel 100 or a user's finger surface in the manufacturing step of the display device.

Therefore, after the manufacture and sale of the display device, if the protective film 190 is attached to the second surface 112 of the display panel 100 by the user, the fingerprint sensor 500 to the user's finger surface The distance of is changed, and accordingly, the size of ultrasonic waves transmitted to the top surface 191 of the protective film 190 or the user's finger surface may be reduced. In this case, the size of the received ultrasonic wave reflected from the top surface 191 or the user's finger surface and transmitted to the receiving electrode 520 may be reduced, and thus, fingerprint sensing sensitivity may be reduced.

In addition, a specific frequency of ultrasonic waves generated by the fingerprint sensor 500 may be set in consideration of the thickness of the protective film 190 in the manufacturing step of the display device. However, if a user who has purchased a display device attaches a protective film 190 having a thickness different from that of the protective film 190 considered in the manufacturing step to the second surface 112 of the display panel 100 , As described above, the size of the received ultrasonic wave reflected from the top surface 191 or the user's finger surface and transmitted to the receiving electrode 520 may be reduced, and accordingly, the fingerprint sensing sensitivity may be reduced. I can.

The present invention is to solve this problem. Detailed information about this will be described below.

First, in the following, a basic configuration of the fingerprint sensor 500 applied to the present invention and a basic method of sensing a fingerprint by the fingerprint sensor 500 will be described with reference to FIG. 6.

6 is an exemplary view showing the configuration of a fingerprint sensor applied to a display device equipped with a frequency variable fingerprint sensor according to the present invention. In particular, in the fingerprint sensor 500 shown in FIG. 6, in order to help understand the structure of the fingerprint pixel 510, the fingerprint pixels shown at the lower left of the fingerprint sensor 500 have driving electrodes TXm- 1, TXm) and the receiving electrodes 540 are not shown, and all configurations of the fingerprint pixels 510 shown in the upper left, upper right and lower right of the fingerprint sensor 50 are shown.

As shown in FIG. 6, the fingerprint sensor 500 extends along a first direction, the receiving electrodes 540 independently provided on each of the fingerprint pixels 510, and extends in the first direction. N sensing lines SL connected to the fingerprint pixels provided along the line, m driving electrodes TX1 to TXm extending along a second direction different from the first direction, the second direction M+1 sensing gate lines SGL1 to SGLm+1 extending along the line, fixed voltage lines VDD extending along the first direction, and a fingerprint common voltage extending along the first direction Includes three transistors T1, T2, and T3 provided in the fingerprint pixel 510 formed by the lines VC and any one sensing line SL and one sensing gate line SGL. do.

As described above with reference to FIGS. 3 and 4, in the present invention, the driving electrode unit 560 may include driving electrodes TX1 to TXm having a rod shape, or It may be composed of one driving electrode. Hereinafter, for convenience of explanation, as shown in FIGS. 3 and 6, a fingerprint sensor 500 provided with a driving electrode unit 560 including driving electrodes TX1 to TXm having a rod shape is provided. It will be described as an example of. However, the contents described below can be similarly applied to the fingerprint sensor 500 provided with the driving electrode unit 560 including only one driving electrode in the form of a plate. Accordingly, specific matters in the fingerprint sensor 500 provided with the driving electrode unit 560 including only one driving electrode will be described separately.

As described above, three transistors T1, T2, and T3 are provided in the fingerprint pixel 510.

Of the three transistors T1, T2, T3, a gate of a first transistor T1 is connected to a receiving electrode 540 corresponding to the fingerprint pixel 510, and a first terminal is the fixed voltage line ( VDD), and the second terminal is connected to the second terminal of the second transistor T2.

Of the three transistors T1, T2, and T3, a gate of a second transistor T1 is connected to the sensing gate line SGL, a first terminal is connected to the sensing line SL, Terminal 2 is connected to the second terminal of the first transistor T1.

A gate of a third transistor T1 among the three transistors T1, T2, and T3 is connected to another sensing gate line SGL adjacent to the sensing gate line, and a first terminal is connected to the first terminal. It is connected to the gate of the transistor T1, and the second terminal is connected to the fingerprint common voltage line VC.

In this case, each of the driving electrodes TX1 to TXm is electrically connected to the fingerprint pixels 510 provided in parallel with the driving electrodes TX1 to TXm. When the driving electrode part 560 is composed of one driving electrode, the one driving electrode is electrically connected to all of the fingerprint pixels 510 provided in the fingerprint sensor 500.

The fingerprint sensor driver 600 supplies driving signals to the driving electrodes TX1 to TXm, and a driving unit 610 and the sensing lines for supplying sensing gate signals to the sensing gate lines SGL1 to SGLm. It includes a fingerprint recognition unit 620 for recognizing a fingerprint using sensing signals received from (SL1 to SLn).

The driving unit 610 is a driving signal supply unit 611 for supplying the driving signals to the driving electrodes TX1 to TXm and a sensing for supplying the sensing gate signals to the sensing gate lines SGL1 to SGLm. A gate signal supply unit 612 is included.

The fingerprint recognition unit 620 amplifies the sensing signal received through each of the sensing lines SGL1 to SGLm, for example, converts the amplified sensing signal into a digital value, and constitutes a fingerprint, Floors and slopes (hereinafter, simply referred to as fingerprint information) are recognized according to the size of the digital value, and fingerprint information recognized by all sensing signals are connected to finally recognize a fingerprint.

A receiving electrode driving unit for supplying a receiving electrode voltage to the receiving electrodes 540 or floating the receiving electrodes 540 may be provided in the driving unit 610 or provided in the fingerprint recognition unit 620 It could be. The receiving electrode voltage may be a ground voltage (ground voltage), or may be any one preset voltage. To this end, each of the receiving electrodes 540 may be connected to the receiving electrode driver through a receiving electrode line. However, when the receiving electrodes 540 are maintained only in a floating state, the receiving electrode driver may not be provided.

A basic method of sensing a fingerprint in the fingerprint sensor 500 having the structure as described above is as follows.

First, the driving signal supply unit 611 is supplied with the receiving electrode voltage to the receiving electrodes 540 or the receiving electrodes 540 are floating, the first sensing gate line SLG1 for a preset period. A driving signal is supplied to the first driving electrode TX1 provided in parallel with ).

In this case, a sensing gate off signal is supplied to all sensing gate lines SGL1 to SGLm including the first sensing gate line SGL1.

Here, the sensing gate off signal refers to a signal for turning off transistors connected to the sensing gate line, and a signal for turning on transistors connected to the sensing gate line is referred to as a sensing gate on signal. The sensing gate-on signal and the sensing gate-off signal are collectively referred to as a sensing gate signal.

Accordingly, while the driving signal is supplied to the first driving electrode TX1, the second transistors T2 are turned off, and thus sensing lines SL1 to T2 connected to the second transistors T2 are turned off. SLn) does not transmit a sensing signal.

Next, after the driving signal is supplied, the receiving electrodes 540 may be floated or another voltage may be supplied to the receiving electrodes 540.

Next, voltages of different magnitudes are applied to each of the receiving electrodes 540 by ultrasonic waves received by the receiving electrodes 540 after being output from the first driving electrode TX1 and reflected by the finger. Voltages are generated.

Each of the receiving electrodes 540 is connected to a gate of the first transistor T1 provided in the fingerprint pixel 510. As described above, the ultrasonic voltage generated through the receiving electrode 540 varies depending on the magnitude of the ultrasonic wave received through the receiving electrode 540.

According to the magnitude of the ultrasonic voltage supplied to the gate of the first transistor T1 through the receiving electrode 540, the magnitude of the current passing through the first transistor T1 and applied to the first transistor T1 The magnitude of the voltage varies.

In this case, the sensing gate-on signal is supplied only to the first sensing gate line SGL1, the sensing gate-off signal is supplied to the remaining sensing gate lines SGL2 to SGLm, and the fixed voltage line VDD A voltage with a constant magnitude is supplied.

Accordingly, all of the third transistors T3 constituting the fingerprint pixels 510 provided along the first sensing gate line SGL1 are turned off, and all of the second transistors T2 are turned on.

Accordingly, the magnitude of the current delivered to the fingerprint recognition unit 620 through the sensing line SL or the magnitude of the voltage varies according to the magnitude of the voltage supplied to the gate of the first transistor T1.

The fingerprint recognition unit 620 uses a magnitude of a current or a voltage transmitted through each of the sensing lines SL1 to SLn to provide a fingerprint pixel 510 along the first sensing gate line SGL1. Fingerprint information corresponding to each of them is generated.

For example, among the fingerprint pixels 510 provided along the first sensing gate line SGL1, the gate of the first transistor T1 of the fingerprint pixel 510 connected to the first sensing line SL1 , An ultrasonic voltage generated by ultrasonic waves received by the receiving electrode 540 provided in the fingerprint pixel 510 is supplied.

When the ultrasonic voltage does not turn on the first transistor T1, current and voltage are not supplied to the first sensing line SL1. The fingerprint recognition unit 620 may recognize this state as a valley or a floor.

When the ultrasonic voltage turns on the first transistor T1, a current flows from the first transistor T1 to the second transistor T2 by a fixed voltage applied through the fixed voltage line VDD. In this case, the second transistor T2 is turned on by the sensing gate-on signal supplied through the first sensing gate line SGL1, and thus, the current transmitted from the first transistor T1 is the second It is supplied to the fingerprint recognition unit 620 through the transistor T2 and the first sensing line SL1.

In addition, when the ultrasonic voltage turns on the first transistor T1, a constant voltage is also generated in the first transistor T1, corresponding to the difference between the fixed voltage and the voltage applied to the first transistor T1. The applied voltage is supplied to the fingerprint recognition unit 620 through the second transistor T2 and the first sensing line SL1.

In this case, the magnitude of the current or the voltage supplied to the fingerprint recognition unit 620 through the first transistor T1, the second transistor T2, and the first sensing line SL1 is the ultrasonic wave May vary depending on voltage. That is, the degree to which the first transistor T1 is turned on depends on the magnitude of the ultrasonic voltage, and the magnitude of the current supplied to the fingerprint recognition unit 620 according to the degree to which the first transistor T1 is turned on. Or the magnitude of the voltage is also different.

Accordingly, the fingerprint recognition unit 620 analyzes the magnitude of the current or voltage received through the first sensing line SL1, and provides fingerprint information corresponding to the analysis result, for example, a valley, a floor, or a slope. Recognize.

Through the processes as described above, fingerprint information corresponding to each of the fingerprint pixels 510 provided along the first sensing gate line SGL1 is generated.

Next, the driving signal supply unit 611 is supplied with the receiving electrode voltage again to the receiving electrodes 540 or the receiving electrodes 540 are floating, and the second sensing gate line SLG2 is applied for a predetermined period. A driving signal is supplied to the second driving electrode TX2 provided in parallel with ).

In this case, a sensing gate off signal is supplied to all sensing gate lines SGL1 to SGLm including the second sensing gate line SGL2.

Accordingly, while the driving signal is supplied to the second driving electrode TX2, the second transistors T2 are turned off, and thus sensing lines SL1 to T2 connected to the second transistors T2 are turned off. SLn) does not transmit a sensing signal.

Next, after the driving signal is supplied, the receiving electrodes 540 may be floated or another voltage may be supplied to the receiving electrodes 540.

Next, ultrasonic voltages of different sizes are generated in each of the receiving electrodes 540 by ultrasonic waves that are output from the second driving electrode TX2 and reflected by the finger and then received by the receiving electrodes 540.

In this case, the sensing gate-on signal is supplied only to the second sensing gate line SGL2, the sensing gate-off signal is supplied to the remaining sensing gate lines SGL1 and SGL3 to SGLm, and the fixed voltage line VDD ) Is supplied with a voltage having a certain magnitude.

Accordingly, all of the third transistors T3 constituting the fingerprint pixels 510 provided along the second sensing gate line SGL2 are turned off, and all of the second transistors T2 are turned on.

Therefore, as described above, according to the magnitude of the ultrasonic voltage supplied to the gate of the first transistor T1, the magnitude of the current delivered to the fingerprint recognition unit 620 through the sensing line SL Or the magnitude of the voltage varies.

The fingerprint recognition unit 620 uses a magnitude of a current or a voltage delivered through each of the sensing lines SL1 to SLn to provide a fingerprint pixel 510 along the second sensing gate line SGL2. Fingerprint information corresponding to each of them is generated.

In this case, the gates of the third transistors T3 of each of the fingerprint pixels 510 provided along the first sensing gate line SGL1 on which fingerprint sensing has already been performed are supplied to the second sensing gate line SGL2. A sensing gate-on signal is supplied. Accordingly, the third transistor T3 of each of the fingerprint pixels 510 provided along the first sensing gate line SGL1 is turned on.

A first terminal of the third transistor T3 is connected to the receiving electrode 540, and a second terminal of the third transistor T3 is connected to the fingerprint common voltage line VC. The fingerprint common voltage line VC is connected to a terminal to which a fingerprint common voltage is supplied. The common fingerprint voltage may be a ground voltage (ground voltage), or may be any one preset voltage. The third transistor T3 performs a function of initializing the fingerprint pixel 510 by discharging the charge remaining in the fingerprint pixel 510 through the fingerprint common voltage line VC after fingerprint sensing.

That is, when fingerprint information corresponding to the fingerprint pixels 510 provided along the second sensing gate line SGL2 is generated by the sensing gate-on signal supplied to the second sensing gate line SGL2, Each of the fingerprint pixels 510 provided along the first sensing gate line SGL1 on which fingerprint sensing has already been completed, a sensing gate-on signal supplied to the second sensing gate line SGL2 and the third transistor T3 ), can be initialized.

Finally, the processes as described above are repeated for the third sensing gate line SGL3 to the m+1th sensing gate line SGLm+1, so that all fingerprint pixels 510 provided in the fingerprint sensor 500 are repeated. Fingerprint information corresponding to) may be generated.

The fingerprint recognition unit 620 combines the fingerprint information identified through the above processes to generate a single fingerprint.

The driving method when the driving electrode unit 560 is formed of one driving electrode may also include the processes described above. That is, compared to the fingerprint sensor 500 provided with the driving electrode unit 560 including the driving electrodes TX1 to TXm, the fingerprint sensor provided with the driving electrode unit 560 including one driving electrode ( The driving method of 500) differs only in that sequentially input driving signals are provided to the entire surface of the fingerprint sensor 500.

In the fingerprint sensor 500 in which the driving electrode unit 560 has driving electrodes TX1 to TXm having a rod shape, a driving electrode parallel to a sensing gate line to which a fingerprint gate-on signal for fingerprint recognition is supplied is separately Since it can be driven, the fingerprint recognition capability of the fingerprint sensor for each location can be improved. In addition, since each of the driving electrodes TX1 to TXm can be sequentially driven, power consumption can be reduced.

Since the structure of the fingerprint sensor 500 in which the driving electrode part 560 has one driving electrode in the form of a plate is simple, the manufacturing cost of the fingerprint sensor 500 is reduced and the manufacturing process of the fingerprint sensor 500 Can be simplified. In addition, the fingerprint sensor 500 having one driving electrode in the form of a plate does not need to be provided with a complicated circuit for sequentially driving the driving electrodes.

7 is an exemplary view showing the configuration of a fingerprint sensor and a fingerprint sensor driver for explaining a method of driving a display device equipped with a frequency-variable fingerprint sensor according to the present invention, and FIG. 8 is a diagram for driving the fingerprint sensor shown in FIG. This is an exemplary diagram showing the waveforms of signals generated by the fingerprint sensor driver.

In the following, for convenience of explanation, as shown in FIG. 7, a fingerprint sensor having 9 driving electrodes TX1 to TX9, a plurality of receiving electrodes 540 and 16 sensing lines SL1 to SL16 ( 500) is described as an example of the present invention. As described above, each of the receiving electrodes 540 is provided on the fingerprint pixel 510.

In this case, the nine driving electrodes TX1 to TX9 are connected to a driving signal supply unit 611 for supplying the driving signals to the driving electrodes TX1 to TXm, and the 16 sensing lines SL1 to SL16 are connected to a fingerprint recognition unit 620 for recognizing a fingerprint using sensing signals received from the fingerprint sensor 500.

In addition, hereinafter, for convenience of explanation, a fingerprint sensor driver 600 that simultaneously supplies driving signals to five adjacent driving electrodes is described as an example of the present invention, but the fingerprint sensor driver 600 is adjacent to Driving signals may be simultaneously supplied to three driving electrodes, driving signals may be simultaneously supplied to seven adjacent driving electrodes, and driving signals may be simultaneously supplied to various numbers of adjacent driving electrodes.

That is, as described above with reference to FIG. 5, the ultrasonic waves output from the first point A are not reflected only to the receiving electrode where the first point A is located, but the first point ( A) It can be reflected by other receiving electrodes around it.

Therefore, the ultrasonic waves received at the first point A, that is, the received ultrasonic waves, include not only the ultrasonic waves output from the first point A, but also ultrasonic waves output and reflected around the first point A. .

The large number of received ultrasound means that there are a lot of data that can be used for analysis, which can improve fingerprint recognition capabilities. That is, the fingerprint information corresponding to the first point (A) generated by using the received ultrasound output from and around the first point (A) and received as the first point (A) is the first point The fingerprint information corresponding to the first point A generated using only the ultrasound output in (A) may include information more consistent with the user's actual fingerprint.

Accordingly, in the present invention, after simultaneously supplying a driving signal to at least three driving electrodes, fingerprint information at a position corresponding to one of the at least three driving electrodes can be generated. Hereinafter, a method of simultaneously supplying a driving signal to five driving electrodes will be described as an example of the present invention. In addition, in the following description, contents identical or similar to those described with reference to FIG. 6 will be omitted or briefly described.

First, the driving signal supply unit 611 includes a first driving electrode TX1 to the third driving electrode of the fingerprint sensor 500 having a structure as shown in FIGS. 6 and 7 in a first period 1P. A driving signal as shown in FIG. 8 is supplied to (TX3). The driving signal may be composed of at least one pulse. Accordingly, although the driving signal composed of three pulses is shown in FIG. 8, the number of pulses constituting the driving signal may be variously changed. In this case, a sensing gate off signal is supplied to all sensing gate lines SGL1 to SGL9 including the first sensing gate line SGL1.

After the driving signal is supplied, the receiving electrodes 540 are floating or another voltage is supplied to the receiving electrodes 540.

The ultrasonic waves output from the first to third driving electrodes TX1 to TX3 and reflected by the finger are transmitted to the first driving electrode TX1.

Next, the sensing gate signal supply unit 612 supplies the sensing gate-on signal only to the first sensing gate line SGL1 during a second period 2P generated after the first period 1P, and The sensing gate off signal is supplied to the sensing gate lines SGL2 to SGL9, and a voltage having a predetermined magnitude is supplied to the fixed voltage line VDD.

Accordingly, all of the third transistors T3 constituting the fingerprint pixels 510 provided along the first sensing gate line SGL1 are turned off, and all of the second transistors T2 are turned on.

Therefore, as described above, according to the magnitude of the ultrasonic voltage supplied to the gate of the first transistor T1, the magnitude of the current delivered to the fingerprint recognition unit 620 through the sensing line SL Or the magnitude of the voltage varies.

The fingerprint recognition unit 620 uses a magnitude of a current or a voltage delivered through each of the sensing lines SL1 to SL16 to provide a fingerprint pixel 510 along the first sensing gate line SGL1. Fingerprint information corresponding to each of them is generated.

In this case, that is, during the second period 2P, the fingerprint recognition unit 620 performs three sensing operations using the sampling control signal SAMPS as shown in FIG. 8.

The sensing signal received through the sensing lines SL1 to SL16 by the first sensing operation during the second period 2P is output from the first driving electrode TX1 and then reflected by the user's finger. It is generated by receiving ultrasonic waves transmitted to the receiving electrodes 540 overlapping the first driving electrode TX1, and the sensing lines SL1 to SL16 are generated by a second sensing operation during the second period 2P. ), the sensing signal received through the second driving electrode TX2 is reflected by the user's finger after being output from the second driving electrode TX2 and transmitted to the receiving electrodes 540 overlapping the first driving electrode TX1. And the sensing signal received through the sensing lines SL1 to SL16 by the third sensing operation during the second period 2P is output from the third driving electrode TX3 and It is generated by receiving ultrasonic waves reflected by a finger and transmitted to the receiving electrodes 540 overlapping the first driving electrode TX1.

The interval and width of the three pulses constituting the sampling control signal SAMPS are output from and received from the first driving electrode TX1 to the third driving electrode TX3, and then transmitted to the first driving electrode TX1. It can be set in various ways by using the spacing and width of ultrasonic waves received by the corresponding receiving electrodes.

That is, the fingerprint recognition unit 620 generates fingerprint information corresponding to each of the fingerprint pixels 510 provided along the first sensing gate line SGL1 by using the three sensing operations as described above. .

Next, the driving signal supply unit 611 supplies a driving signal to the first to fourth driving electrodes TX1 to TX4 during the third period 3P. In this case, a sensing gate off signal is supplied to all sensing gate lines SGL1 to SGL9 including the first sensing gate line SGL1.

Next, the sensing gate signal supply unit 612 supplies the sensing gate-on signal only to the second sensing gate line SGL2 during a fourth period 4P generated after the third period 3P, and The sensing gate off signal is supplied to the sensing gate lines SGL1 and SGL3 to SGL9, and a voltage having a predetermined magnitude is supplied to the fixed voltage line VDD.

Accordingly, all of the third transistors T3 constituting the fingerprint pixels 510 provided along the second sensing gate line SGL2 are turned off, and all of the second transistors T2 are turned on.

During the fourth period (4P), the fingerprint recognition unit 620 performs three sensing operations using the sampling control signal SAMPS as illustrated in FIG. 8, and thus the second sensing gate line SGL2 Fingerprint information corresponding to each of the fingerprint pixels 510 provided along the line is generated.

That is, the sensing signal received through the sensing lines SL1 to SL16 by the first sensing operation during the fourth period 4P is output from the second driving electrode TX2 and then reflected by the user's finger. Is generated by receiving ultrasonic waves transmitted to the receiving electrodes 540 overlapping the second driving electrode TX2, and the sensing lines SL1 are generated by a second sensing operation during the fourth period 4P. The sensing signal received through the to SL16) is output from the first driving electrode TX1 and the third driving electrode TX3 and is reflected by the user's finger to overlap the second driving electrode TX2. The sensing signal generated by the received ultrasonic waves transmitted to the receiving electrodes 540 and received through the sensing lines SL1 to SL16 by the third sensing operation during the fourth period 4P is the fourth After being output from the driving electrode TX4, it is reflected by the user's finger and generated by receiving ultrasonic waves transmitted to the receiving electrodes 540 overlapping with the second driving electrode TX2.

In this case, in FIG. 7, since there is no driving electrode at the top of the first driving electrode TX1 and the second driving electrode TX2 and the third driving electrode TX3 are provided only at the bottom, the second period ( In the second sensing operation and the third sensing operation of 2P), only a sensing signal by ultrasonic waves output from one driving electrode (the second driving electrode TX2 or the third driving electrode TX3) is used.

However, since the first driving electrode TX1 is provided on the upper end of the second driving electrode TX2 and the third driving electrode TX3 and the fourth driving electrode TX4 are provided at the lower end, the fourth In the second sensing operation of the period 4P, a sensing signal generated by ultrasonic waves output from the first driving electrode TX1 and the third driving electrode TX3 is used, and the third sensing of the fourth period 4P. In the operation, only the sensing signal by ultrasonic waves output from the fourth driving electrode TX4 is used.

That is, since the first driving electrode TX1 and the third driving electrode TX3 are spaced apart at the same interval based on the second driving electrode TX2, the first driving electrode TX1 and the first driving electrode TX1 are separated from each other. 3 The ultrasonic wave output from the driving electrode TX3 is received at a position corresponding to the second driving electrode TX2 in the same period, and therefore, in the second sensing operation of the fourth period 4P, the first driving electrode A sensing signal by ultrasonic waves output from TX1 and the third driving electrode TX3 is used.

However, since there is no driving electrode spaced at the same interval as the fourth driving electrode TX4 with respect to the second driving electrode TX2, the fourth sensing operation is performed in the third sensing operation of the fourth period 4P. Only the sensing signal by ultrasonic waves output from the driving electrode TX4 is used.

That is, the fingerprint recognition unit 620 uses the three sensing operations as described above to each of the fingerprint pixels 510 provided along the second sensing gate line SGL2 during the fourth period 4P. Generate fingerprint information corresponding to.

Next, the driving signal supply unit 611 supplies a driving signal to the first to fifth driving electrodes TX1 to TX5 in the fifth period 5P. In this case, a sensing gate off signal is supplied to all sensing gate lines SGL1 to SGL9 including the third sensing gate line SGL1.

Next, the sensing gate signal supply unit 612 supplies the sensing gate-on signal only to the third sensing gate line SGL3 during a sixth period 6P generated after the fifth period 5P, and The sensing gate off signal is supplied to the sensing gate lines SGL1, SGL2, and SGL4 to SGL9, and a voltage having a predetermined magnitude is supplied to the fixed voltage line VDD.

Accordingly, all of the third transistors T3 constituting the fingerprint pixels 510 provided along the third sensing gate line SGL3 are turned off, and all of the second transistors T2 are turned on.

During the sixth period (6P), the fingerprint recognition unit 620 performs three sensing operations using the sampling control signal SAMPS as illustrated in FIG. 8, and thus the third sensing gate line SGL3 Fingerprint information corresponding to each of the fingerprint pixels 510 provided along the line is generated.

That is, the sensing signal received through the sensing lines SL1 to SL16 by the first sensing operation during the sixth period 6P is output from the third driving electrode TX3 and then reflected by the user's finger. Is generated by receiving ultrasonic waves transmitted to the receiving electrodes 540 overlapping the third driving electrode TX3, and the sensing lines SL1 are generated by a second sensing operation during the sixth period 6P. The sensing signal received through the to SL16 is output from the second driving electrode TX2 and the fourth driving electrode TX4, and is reflected by the user's finger to overlap the third driving electrode TX3. The sensing signal generated by the received ultrasonic waves transmitted to the receiving electrodes 540 and received through the sensing lines SL1 to SL16 by the third sensing operation during the sixth period 6P is the first After being output from the driving electrode TX1 and the fifth driving electrode TX5, the received ultrasonic wave is reflected by the user's finger and transmitted to the receiving electrodes 540 overlapping the third driving electrode TX3. It was created.

The first driving electrode TX1 and the second driving electrode TX2 are provided at an upper end of the third driving electrode TX3, and the fourth driving electrode TX4 and the fifth driving electrode TX5 are provided at a lower end. Is provided, in the second sensing operation of the sixth period 6P, a sensing signal generated by the received ultrasonic waves output from the second driving electrode TX1 and the fourth driving electrode TX4 is used, and the In the third sensing operation of the sixth period 6P, a sensing signal generated by received ultrasonic waves output from the first driving electrode TX1 and the fifth driving electrode TX5 is used.

That is, since the second driving electrode TX2 and the fourth driving electrode TX4 are spaced apart at the same interval based on the third driving electrode TX3, the second driving electrode TX2 and the The ultrasonic wave output from the fourth driving electrode TX4 is received at a position corresponding to the third driving electrode TX3 in the same period, and thus, the second driving in the second sensing operation of the sixth period 6P A sensing signal by ultrasonic waves output from the electrode TX2 and the fourth driving electrode TX4 is used.

In addition, since the first driving electrode TX1 and the fifth driving electrode TX5 are spaced apart at the same interval based on the third driving electrode TX3, the first driving electrode TX1 and the 5 The ultrasonic wave output from the driving electrode TX5 is received at a position corresponding to the third driving electrode TX3 in the same period, and therefore, in the third sensing operation of the sixth period 6P, the first driving electrode A sensing signal by ultrasonic waves output from TX1 and the fifth driving electrode TX5 is used.

That is, the fingerprint recognition unit 620 uses the three sensing operations as described above to each of the fingerprint pixels 510 provided along the third sensing gate line SGL3 during the sixth period 6P. Generate fingerprint information corresponding to.

Next, the operations performed in the fifth period 5P and the sixth period 6P are performed by the same principle in the fourth driving electrodes TX4 to the seventh driving electrodes TX7.

Accordingly, in the seventh period 7P and the eighth period 8P, fingerprint information corresponding to each of the fingerprint pixels 510 provided along the fourth sensing gate line SGL4 is generated, and the ninth period ( In 9P) and 10th period 10P, fingerprint information corresponding to each of the fingerprint pixels 510 provided along the fifth sensing gate line SGL5 is generated, and during the 11th period 11P and the 12th period ( In 12P), fingerprint information corresponding to each of the fingerprint pixels 510 provided along the sixth sensing gate line SGL6 is generated, and in the 13th period 13P and the 14th period 14P, the seventh sensing Fingerprint information corresponding to each of the fingerprint pixels 510 provided along the gate line SGL7 is generated.

Next, the operation performed in the third period 3P and the fourth period 4P is performed on the same principle in the fifteenth period 15P and the sixteenth period 16P.

That is, in the fifteenth period 15P and the sixteenth period 16P, the eighth sensing gate line is formed by four driving electrodes, that is, the sixth driving electrode TX6 to the ninth driving electrode TX9. Fingerprint information corresponding to each of the fingerprint pixels 510 provided along the SGL8 is generated.

Next, the operation performed in the first period 1P and the second period 2P is performed on the same principle in the 17th period 17P and the 18th period 18P.

That is, in the seventeenth period 17P and the eighteenth period 18P, the ninth sensing gate line is formed by three driving electrodes, that is, the seventh driving electrode TX7 to the ninth driving electrode TX9. Fingerprint information corresponding to each of the fingerprint pixels 510 provided along the (SGL9) is generated.

Finally, the fingerprint recognition unit 620 combines fingerprint information identified through the above processes to generate a single fingerprint.

The fingerprint recognition unit 620 may determine whether the fingerprint matches the reference fingerprint by comparing the fingerprint with the reference fingerprint stored in the storage unit 630.

The result of determining whether the fingerprint matches the reference fingerprint is executed in various electronic devices using a display device equipped with a frequency variable fingerprint sensor according to the present invention, for example, a smartphone, a tablet PC, a monitor, a TV, etc. It can be used in applications that become

For example, when an application running on a smartphone requires user authentication using a fingerprint, the smartphone may perform user authentication according to a determination result transmitted from the fingerprint recognition unit 620.

According to the present invention as described above, since the sensing gate lines provided in the fingerprint sensor can be individually driven, fingerprint information corresponding to the position where the sensing gate line is driven can be accurately generated, and accordingly, fingerprint recognition Skills can be improved.

9 is another exemplary view showing a configuration of a fingerprint sensor and a fingerprint sensor driver for explaining a method of driving a display device equipped with a frequency variable fingerprint sensor according to the present invention, and FIG. 10 is a diagram illustrating the fingerprint sensor shown in FIG. This is an exemplary diagram showing waveforms of signals generated by a fingerprint sensor driver to drive.

As described above, the driving electrode unit 560 applied to the present invention may include driving electrodes having a rod shape, but may also include one driving electrode in a plate shape.

The method described above with reference to FIGS. 7 and 8 is a driving method in a display device including the driving electrode unit 560 including driving electrodes having a rod shape.

Hereinafter, with reference to FIGS. 9 and 10, a driving method in a display device including the driving electrode unit 560 configured with one driving electrode in a plate shape will be described.

A driving method in a display device including the driving electrode unit 560 configured with one driving electrode is similar to the method described with reference to FIGS. 7 and 8.

Therefore, if the resolution at which the fingerprint sensor shown in FIG. 9 recognizes a fingerprint is the same as or similar to the resolution at which the fingerprint sensor shown in FIG. 7 recognizes a fingerprint, the display device shown in FIG. 9 is It can be driven using signals similar to the signals.

However, since the fingerprint sensor 500 illustrated in FIG. 9 includes only one driving electrode TX, a driving signal supplied from the driving signal supply unit 611 to the driving electrode TX is illustrated in FIG. 10. It can be configured as described.

That is, the driving signal supply unit 611 supplies the driving signal to the driving electrode TX only in odd-numbered periods of the first period 1P to 18th period 18P, as shown in FIG. 10. .

In this case, the fingerprint recognition unit 620 may generate fingerprint information in each of the fingerprint pixels 510 by using the same method as described with reference to FIGS. 7 and 8, and the fingerprint information You can finally create a fingerprint using them. A method of driving the display device using the fingerprint sensor 500 and signals shown in FIG. 9 is as follows. In the following description, contents identical or similar to those described with reference to FIGS. 7 and 8 will be omitted or briefly described.

First, the driving signal supply unit 611 transmits a driving signal as shown in FIG. 10 to the driving electrode TX of the fingerprint sensor 500 having a structure as shown in FIG. 9 in the first period 1P. Supply. In this case, a sensing gate off signal is supplied to all sensing gate lines SGL1 to SGLm including the first sensing gate line SGL1.

After the driving signal is supplied, the receiving electrodes 540 are floating or another voltage is supplied to the receiving electrodes 540.

Next, the sensing gate signal supply unit 612 supplies the sensing gate-on signal only to the first sensing gate line SGL1 during a second period 2P generated after the first period 1P, and The sensing gate off signal is supplied to the sensing gate lines SGL2 to SGL9, and a voltage having a predetermined magnitude is supplied to the fixed voltage line VDD.

In this case, that is, during the second period 2P, the fingerprint recognition unit 620 performs three sensing operations using the sampling control signal SAMPS as shown in FIG. 10.

The sensing signal received through the sensing lines SL1 to SL16 by the first sensing operation during the second period 2P is connected to the first sensing gate line SGL1 among the driving electrodes TX. The receiving electrode 540 at a position corresponding to the fingerprint pixels 510 connected to the first sensing gate line SGL1 after being output from an area corresponding to the fingerprint pixels 510 and reflected by a user's finger The sensing signal generated by the received ultrasonic waves transmitted to and received through the sensing lines SL1 to SL16 by the second sensing operation during the second period 2P is the one of the driving electrodes TX. The fingerprint pixels 510 that are output from the regions corresponding to the fingerprint pixels 510 connected to the second sensing gate line SGL2 and then reflected by the user's finger and connected to the first sensing gate line SGL1 ) Is generated by the reception ultrasonic waves transmitted to the reception electrodes 540 at positions corresponding to those, and received through the sensing lines SL1 to SL16 by a third sensing operation during the second period 2P. The sensing signal is output from a region of the driving electrode TX corresponding to the fingerprint pixels connected to the third sensing gate line SGL3, and is reflected by the user's finger, and the first sensing gate line SGL1 ) Is generated by receiving ultrasonic waves transmitted to the receiving electrodes 540 at locations corresponding to the fingerprint pixels 510 connected to the ).

That is, the fingerprint recognition unit 620 generates fingerprint information corresponding to each of the fingerprint pixels 510 provided along the first sensing gate line SGL1 by using the three sensing operations as described above. .

Next, the driving signal supply unit 611 supplies a driving signal to the driving electrode TX in the third period 3P. In this case, a sensing gate off signal is supplied to all the sensing gate lines SGL1 to SGL9.

Next, the sensing gate signal supply unit 612 supplies the sensing gate-on signal only to the second sensing gate line SGL2 during a fourth period 4P generated after the third period 3P, and The sensing gate off signal is supplied to the sensing gate lines SGL2 to SGL9, and a voltage having a predetermined magnitude is supplied to the fixed voltage line VDD.

During the fourth period (4P), the fingerprint recognition unit 620 performs three sensing operations using the sampling control signal SAMPS as shown in FIG. 10, thereby the second sensing gate line SGL2. Fingerprint information corresponding to each of the fingerprint pixels 510 provided along the line is generated.

That is, the sensing signal received through the sensing lines SL1 to SL16 by the first sensing operation during the fourth period 4P is connected to the second sensing gate line SGL2 among the driving electrodes TX. The receiving electrode at a location corresponding to the fingerprint pixels 510 connected to the second sensing gate line SGL2 after being output from a region corresponding to the fingerprint pixels 510 being output and reflected by the user's finger ( The sensing signal generated by the received ultrasonic waves transmitted to 540 and received through the sensing lines SL1 to SL16 by the second sensing operation during the fourth period 4P is the driving electrode TX The second sensing gate is output from an area corresponding to the fingerprint pixels 510 connected to the first sensing gate line SGL1 and the third sensing gate line SGL3 and is reflected by a user's finger. It is generated by receiving ultrasonic waves transmitted to the receiving electrodes 540 at positions corresponding to the fingerprint pixels 510 connected to the line SGL2, and during the third sensing operation during the fourth period 4P. Thus, the sensing signal received through the sensing lines SL1 to SL16 is output from a region of the driving electrode TX corresponding to the fingerprint pixels 510 connected to the fourth sensing gate line SGL4. It is generated by the received ultrasonic waves reflected by the user's finger and transmitted to the receiving electrodes 540 at positions corresponding to the fingerprint pixels 510 connected to the second sensing gate line SGL2.

That is, the fingerprint recognition unit 620 uses the three sensing operations as described above to each of the fingerprint pixels 510 provided along the second sensing gate line SGL2 during the fourth period 4P. Generate fingerprint information corresponding to.

Next, the driving signal supply unit 611 supplies a driving signal to the driving electrode TX in the fifth period 5P. In this case, a sensing gate off signal is supplied to all the sensing gate lines SGL1 to SGL9.

Next, the sensing gate signal supply unit 612 supplies the sensing gate-on signal only to the third sensing gate line SGL3 during a sixth period 6P generated after the fifth period 5P, and The sensing gate off signal is supplied to the sensing gate lines SGL2 to SGL9, and a voltage having a predetermined magnitude is supplied to the fixed voltage line VDD.

During the sixth period (6P), the fingerprint recognition unit 620 performs three sensing operations using the sampling control signal SAMPS as shown in FIG. 10, thereby the third sensing gate line SGL3. Fingerprint information corresponding to each of the fingerprint pixels 510 provided along the line is generated.

That is, the sensing signal received through the sensing lines SL1 to SL16 by the first sensing operation during the sixth period 6P is connected to the third sensing gate line SGL3 among the driving electrodes TX. The receiving electrode at a location corresponding to the fingerprint pixels 510 connected to the third sensing gate line SGL3 after being output from a region corresponding to the fingerprint pixels 510 that are being outputted and reflected by the user's finger ( The sensing signal generated by the received ultrasonic waves transmitted to the 540 and received through the sensing lines SL1 to SL16 by the second sensing operation during the sixth period 6P is the driving electrode TX The third sensing gate is output from an area corresponding to the fingerprint pixels 510 connected to the second sensing gate line SGL2 and the fourth sensing gate line SGL4 and is reflected by the user's finger. It is generated by receiving ultrasonic waves transmitted to the receiving electrodes 540 at positions corresponding to the fingerprint pixels 510 connected to the line SGL3, and by the third sensing operation during the sixth period 6P. The sensing signal received through the sensing lines SL1 to SL16 is a fingerprint pixel 510 connected to the first sensing gate line SGL1 and the fifth sensing gate line SGL5 among the driving electrodes TX. ), and then reflected by the user's finger and transmitted to the receiving electrodes 540 at positions corresponding to the fingerprint pixels 510 connected to the third sensing gate line SGL3. It is generated by the received ultrasound.

That is, the fingerprint recognition unit 620 uses the three sensing operations as described above to each of the fingerprint pixels 510 provided along the third sensing gate line SGL3 during the sixth period 6P. Generate fingerprint information corresponding to.

Next, the operation performed in the fifth period 5P and the sixth period 6P is based on the same principle for the fingerprint pixels connected to the fourth sensing gate line SGL4 to the seventh sensing gate line SGL7. Performed.

Accordingly, in the seventh period 7P and the eighth period 8P, fingerprint information corresponding to each of the fingerprint pixels 510 provided along the fourth sensing gate line SGL4 is generated, and the ninth period ( In 9P) and 10th period 10P, fingerprint information corresponding to each of the fingerprint pixels 510 provided along the fifth sensing gate line SGL5 is generated, and during the 11th period 11P and the 12th period ( In 12P), fingerprint information corresponding to each of the fingerprint pixels 510 provided along the sixth sensing gate line SGL6 is generated, and in the 13th period 13P and the 14th period 14P, the seventh sensing Fingerprint information corresponding to each of the fingerprint pixels 510 provided along the gate line SGL7 is generated.

Next, the operation performed in the third period 3P and the fourth period 4P is performed on the same principle in the fifteenth period 15P and the sixteenth period 16P.

That is, fingerprint information corresponding to each of the fingerprint pixels 510 provided along the eighth sensing gate line SGL8 is generated during the fifteenth period 15P and the sixteenth period 16P.

Next, the operation performed in the first period 1P and the second period 2P is performed on the same principle in the 17th period 17P and the 18th period 18P.

That is, fingerprint information corresponding to each of the fingerprint pixels 510 provided along the ninth sensing gate line SGL9 is generated during the 17th period 17P and the 18th period 18P.

Finally, the fingerprint recognition unit 620 combines fingerprint information identified through the above processes to generate a single fingerprint.

The fingerprint sensor 500 may be provided so as to correspond to only a part of the total area of the display panel 100, but may be provided in substantially the same shape as the display panel 100 as the utilization of the fingerprint increases.

In particular, since the location where the user's fingerprint is input does not need to be larger than the display area 120, the fingerprint sensor 500 is, for example, at least in a size and shape that can cover the display area 120. It can be provided.

The fingerprint sensor applied to the present invention has a structure as shown in FIG. 6 and can be driven by the method described with reference to FIGS. 6 to 10, but the present invention is not limited thereto.

That is, the fingerprint sensor applied to the present invention may have a structure different from that shown in FIG. 6 and may be driven in a method different from the method described in FIGS. 6 to 10.

Hereinafter, a method of changing the frequency of the fingerprint sensor 500 by the display device equipped with the frequency variable fingerprint sensor according to the present invention will be described with reference to FIGS. 1 to 13.

11 is a graph showing a change in the size of a touch sensing signal according to a thickness of a cover in a display device equipped with a frequency variable fingerprint sensor according to the present invention, and FIG. 12 is a display device equipped with a frequency variable fingerprint sensor according to the present invention. An exemplary view showing a change in sound pressure of ultrasonic waves according to a change in frequency of ultrasonic waves, and FIG. 13 is a graph showing characteristics of ultrasonic waves for each frequency in a display device including a frequency variable fingerprint sensor according to the present invention. In the following description, the same or similar content as described with reference to FIGS. 1 to 10 will be omitted or briefly described. First, the touch driver 700 provided in a display device equipped with a frequency variable fingerprint sensor according to the present invention supplies a touch driving signal to the touch panel 800 while the display device is being driven. The touch driver 700 uses the touch sensing signals received from the touch panel 800 according to the touch driving signal to determine whether a touch has occurred and a touch position at which the touch has occurred.

The method of determining the touch position may be variously changed according to the structure and driving method of the touch panel 800, as described above.

Hereinafter, for convenience of description, a display device in which the touch panel 800 and the touch driver 700 are driven using a self-cap method will be described as an example of the present invention.

The touch driver 700 may determine whether or not a touch is performed using the amount of change of the touch sensing signals, and may determine the touch position according to the position of the touch electrode to which the touch sensing signals are transmitted.

For example, when the size of the touch sensing signal is 0 when there is no touch, and the size of the touch sensing signal is 1 when there is a touch, the size of the actually sensed touch sensing signal is 0. 6 to 1 If included therebetween, the touch driver 700 may determine that a touch has been made to the touch electrode where the touch sensing signal is generated.

For example, even if the size of the touch sensing signal is reduced by 40% of a normal case, the touch driver 700 may normally determine whether a touch is present. When the size of the touch sensing signal is reduced by more than 40% of the normal case, the touch driver 700 may determine that it is a touch sensing error rather than a thickness problem of the cover.

The touch status and touch location information determined through the above processes are transmitted to an external system of the electronic device, and the external system executes various applications using the touch location information.

Next, the touch driver 700 determines whether or not the thickness of the cover is within a reference thickness range by using the size of the touch sensing signal while or after determining whether or not the touch has been touched.

The change in the size of the touch sensing signal may occur according to a change in the thickness of the display panel 100, and in particular, may occur according to a change in the thickness of the cover of the display panel 100. The thickness of the cover changes the size of ultrasonic waves used for fingerprint sensing, and the size of the ultrasonic waves may be changed according to the frequency of the ultrasonic waves.

That is, even if the thickness of the cover is changed, touch sensing may be performed normally, but fingerprint sensing may not be performed normally.

Accordingly, when the thickness of the cover is changed and the size of the touch sensing signal is changed, the frequency of the ultrasonic wave must be changed, so that fingerprint sensing can be performed normally.

In the following description, the cover means only the cover glass 150 in a display device without a protective film as shown in FIG. 5A, and a display to which a protective film 190 is further attached as shown in FIG. 5B. In the device, it means the cover glass 150 and the protective film 190.

The thickness of the cover glass 150 in the display panel 100 is several tens of times the thickness of the display panel 100 excluding the cover glass 150, and thus, the size of the touch sensing signal and the ultrasonic wave Is influenced by the thickness of the cover glass 150.

In addition, since the thickness of the protective film 190 is similar to the thickness of the cover glass 150, the size of the touch sensing signal and the ultrasonic wave is also influenced by the thickness of the protective film 190.

To explain more, the size of the touch sensing signal and the ultrasonic wave depends on the thickness of the cover, where the cover may mean only the cover glass 150, and the cover glass 150 and the protection It may also mean a film 190.

For example, a range of touch sensing signals having a size in which fingerprint sensing can be performed normally (hereinafter, simply referred to as a reference touch sensing signal range) and a range of thicknesses of a cover corresponding to the reference touch sensing signal range (hereinafter, simply referred to as The reference thickness range) may be set during the manufacturing process of the display device.

When the thickness of the cover is included in the reference thickness range, the size of the touch sensing signal may be included in the reference touch sensing signal range. When the thickness of the cover is out of the reference thickness range, the size of the touch sensing signal is out of the reference touch sensing signal range. In this case, touch sensing may be performed normally, but fingerprint sensing may not be performed normally.

For example, when the thickness of the cover glass 150 used in the manufacturing process of the display device is much smaller than the general thickness, and the thickness of only the cover glass 150 after the manufacturing of the display device is completed is less than the reference thickness range, or , Even if the protective film 190 is attached to the cover glass 150 after the manufacturing of the display device is completed because the thickness of the cover glass 150 used in the manufacturing process of the display device is much smaller than the general thickness, the cover glass 150 And when the thickness of the protective film 190 is smaller than the reference thickness range, or the thickness of the cover glass 150 used in the manufacturing process of the display device is much larger than the general thickness, When the thickness of the cover glass 150 alone is greater than the reference thickness range, or the thickness of the protective film 190 attached to the cover glass 150 after the display device is manufactured is the size considered in the manufacturing process of the display device When the thickness of the protective film 190 and the cover glass 150 is much larger than the reference thickness range, or the like, the size of the touch sensing signal may be out of the reference touch sensing signal range.

Here, the unit representing the size of the touch sensing signal may be a current, a voltage, or a resistance.

In addition, a unit representing the size of the touch sensing signal may be various units that can be used during touch sensing in addition to the units (current, voltage, resistance). For example, the unit indicating the size of the touch sensing signal may be a unit indicating the size of the digital touch sensing signal. The digital touch sensing signal refers to a signal in which an analog touch sensing signal received from the touch panel 800 is changed by an analog-digital converter constituting the touch driver 700.

For example, (a) of FIG. 11 shows the size of the touch sensing signal when the thickness of the cover is within the reference thickness range, and (b) of FIG. 11 shows that the thickness of the cover is smaller than the reference thickness range. It represents the size of the touch sensing signal in case.

That is, assuming that the unit shown in the graphs of FIGS. 11A and 11B is a unit indicating the size of the digital touch sensing signal used for the touch sensing, the thickness of the cover is within the range of the reference thickness. In the case, the size of the touch sensing signal has a value of about 2500 to 3000. The value is included in the range of the reference touch sensing signal.

However, when the thickness of the cover is larger than the reference thickness range, the size of the touch sensing signal has a value of about 1500 to 2000. The value is out of the range of the reference touch sensing signal.

In the above example, the size of the touch sensing signal when the thickness of the cover is larger than the reference thickness range is between 60 and 99% of the size of the touch sensing signal when the thickness of the cover is within the reference thickness range. Can be included.

The size of the touch sensing signal may be variously changed according to the thickness of the cover, as described above.

Hereinafter, for convenience of explanation, the sizes of the touch sensing signals in which normal fingerprint sensing can be performed are referred to as the reference touch sensing signal range, and the thicknesses of the covers that generate the sizes of the touch sensing signals within the reference touch sensing signal range are the reference. It is called the thickness range.

In this case, when the thickness of the cover is outside the reference thickness range, the size of the touch sensing signal is included between 60 and 99% of the size of the touch sensing signal when the thickness of the cover is within the reference thickness range. I can.

The touch driver 700 determines whether the thickness of the cover is within the reference thickness range, using the principle as described above, while determining whether or not the touch is touched. Judge whether or not.

For example, when the size of the touch sensing signal is included in the range of the reference touch sensing signal, the touch driver 700 determines that the thickness of the cover is included in the range of the reference thickness.

However, when the size of the touch sensing signal is smaller than the reference touch sensing signal range, the touch driver 700 determines that the thickness of the cover is greater than the reference thickness range.

The determination process as described above may be performed by the touch driver 700, but may be performed by a component other than the touch driver 700. For example, the determination process as described above may be performed by the control unit 400. However, in the following description, for convenience of explanation, a display device in which the determination process is performed by the touch driver 700 is described as an example of the present invention.

When the size of the touch sensing signal is greater than the range of the reference touch sensing signal, it means that the touch sensing sensitivity is excellent, and when the touch sensing sensitivity is excellent, the fingerprint sensing sensitivity may also be excellent. Accordingly, a description of the case where the size of the touch sensing signal is larger than the range of the reference touch sensing signal is omitted.

However, even when the size of the touch sensing signal is larger than the range of the reference touch sensing signal, if a problem of decreasing fingerprint sensing sensitivity occurs, the present invention can be applied.

In addition, when the thickness of the cover is smaller than the reference thickness range, if a problem of decreasing fingerprint sensing sensitivity occurs, the present invention can also be applied in this case.

That is, in the following description, when the size of the touch sensing signal is smaller than the range of the reference touch sensing signal, and accordingly, when it is determined that the thickness of the cover is greater than the reference thickness range, the frequency of the driving signal for fingerprint sensing is The method of changing is described as an example of the present invention. With this invention, a decrease in fingerprint sensing sensitivity can be prevented.

However, the present invention, as described above, when the size of the touch sensing signal is larger than the reference touch sensing signal range and thus the fingerprint sensing sensitivity is lowered, or when the thickness of the cover is smaller than the reference thickness range, the fingerprint sensing sensitivity It can also be applied in case of deterioration.

In the above description, only the case where the size of the touch sensing signal is used to determine whether the thickness of the cover is within the reference thickness range has been described.

However, according to the present invention, it is possible to determine whether the thickness of the cover is within the reference thickness range by further using the touch position information together with the size of the touch sensing signal.

For example, not only when the thickness of the cover is larger than the reference thickness range, but also when the area of the user's finger in contact with the display panel 100 is small, the size of the touch sensing signal may be reduced. For example, even if the thickness of the cover is within the reference thickness range, when the user touches the display panel with a weak force, the size of the touch sensing signal may not be included in the reference touch sensing signal range. The area of the user's finger in contact with the display panel 100 may be determined using the touch location information.

Therefore, the touch driver 700, if the size of the touch sensing signal is smaller than the range of the reference touch sensing signal, and the area of the user's finger in contact with the display panel 100 is greater than or equal to a preset area, the It may be determined that the thickness of the cover is greater than the reference thickness range.

That is, the cause of the decrease in the size of the touch sensing signal may be because the thickness of the cover is larger than the reference thickness range, but may be because the area of the user's finger in contact with the display panel 100 is small.

Therefore, rather than determining the thickness of the cover using only the size of the touch sensing signal, the thickness of the cover is used with the size of the touch sensing signal and the area of the user's finger in contact with the display panel 100. Judging the results can lead to more accurate results.

However, when a user touches the display panel 100, a method of using an area of the user's finger in contact with the display panel 100 may be additionally used, since generally the same force is applied.

For example, the touch driver 700 may determine whether the thickness of the cover is greater than the reference thickness range using only the size of the touch sensing signal. Even after the size of the ultrasonic wave for fingerprint recognition is changed according to the determination result, if it is determined that the size of the touch sensing signal is small, the touch driver 700 contacts the display panel 100 together with the size of the touch sensing signal. It may be determined whether the thickness of the cover is greater than the reference thickness range by using the area of the user's finger.

If it is determined that the reason why the size of the touch sensing signal is small is that the area of the user's finger in contact with the display panel 100 is small, the touch driver 700 changes the size of the ultrasonic wave to the original size. A control signal to be performed may be transmitted to the controller 400.

In this case, the controller 400 may transmit a control signal indicating that the area of the user's finger in contact with the display panel 100 is small to an external system that controls the electronic device.

When the control signal is transmitted from the control unit 400, the external system may generate input image data corresponding to the phrase that the finger is in close contact with the display panel 100 for fingerprint sensing and transmit it to the control unit 400. have.

When the control unit 400 transmits image data corresponding to the input image data to the data driver 300, the text may be output on the display panel. A user who checks the phrase from the display panel 100 may bring his or her finger closer to the display panel 100 than that of the display panel 100. Accordingly, the size of the touch sensing signal may be included in the range of the reference touch sensing signal, and thus, fingerprint sensing may be normally performed.

Next, when it is determined that the thickness of the cover is larger than the reference thickness range, the touch driver 700 calculates the thickness of the cover using the size of the touch sensing signal.

For example, the touch driver 700 may calculate the thickness of the cover by using a thickness lookup table indicating a relationship between the size of the touch sensing signal and the thickness of the cover.

The above-described function may be performed by the touch driver 700, but may be performed by the control unit 400 or by another component, and the fingerprint sensor driver receiving the size of the touch sensing signal. It may also be performed at 600.

Hereinafter, for convenience of description, a display device in which the touch driver 700 calculates the thickness of the cover will be described as an example of the present invention.

Information on the thickness of the cover may be stored in the touch driver 700, the control unit 400, or the storage unit 450.

Next, when the fingerprint recognition process is executed by an application of an electronic device (for example, a smartphone, a tablet PC, etc.) including a display device equipped with a frequency variable fingerprint sensor according to the present invention, the electronic device is controlled. The external system may transmit a control signal notifying that the fingerprint recognition process has been executed to the controller 400.

The control unit 400 transmits, to the fingerprint sensor driver 600, a fingerprint sensor control signal (FCS) informing that a fingerprint recognition process has been executed. The driver 610 and the fingerprint recognition unit 620 that have received the fingerprint sensor control signal FCS may perform a preparation procedure for fingerprint recognition.

In this case, information on the thickness of the cover and a control signal for changing the frequency of ultrasonic waves may be transmitted to the fingerprint sensor driver 600 through various timings and various paths.

For example, the touch driver 700 determines whether the thickness of the cover is within the reference thickness range whenever it is determined that there is a touch, or when a preset number of touches are generated, regardless of fingerprint sensing. You can judge whether or not. When it is determined that the thickness of the cover exceeds the reference thickness range, the touch driver 700 may store a control signal for changing the thickness of the cover and the frequency of ultrasonic waves. Thereafter, when a signal indicating that fingerprint sensing is performed is received from the controller 400, the touch driver 700 transmits information on the thickness of the cover and a control signal for changing the frequency of the ultrasonic wave to the fingerprint sensor driver 600. Can be transferred to.

In another example, the touch driver 700 may determine whether the thickness of the cover is within the reference thickness range, regardless of fingerprint sensing. When it is determined that the thickness of the cover exceeds the reference thickness range, the touch driver 700 may transmit a control signal for changing the thickness of the cover and the frequency of ultrasonic waves to the control unit 400, and the control unit ( 400) stores the thickness and control signal. When a control signal indicating that the fingerprint recognition process has been executed is received from the external system, the control unit 400 transmits information on the thickness of the cover and a control signal for changing the frequency of ultrasonic waves to the fingerprint sensor driver 600. I can.

In another example, when a control signal indicating that a fingerprint recognition process has been executed from the controller 400 is received, the touch driver 700 may determine whether the thickness of the cover is within the reference thickness range. . When it is determined that the thickness of the cover exceeds the reference thickness range, the touch driver 700 transmits a control signal for changing the thickness of the cover and the frequency of ultrasonic waves to the control unit 400 or the fingerprint sensor driver 600 Can be transferred to. Receiving a control signal for changing the thickness of the cover and the frequency of ultrasonic waves from the touch driver 700, the controller 400 transmits a control signal for changing the thickness of the cover and the frequency of ultrasonic waves to the fingerprint sensor driver ( 600).

Next, when information on the thickness of the cover and a control signal for changing the frequency of the ultrasonic wave are received, the fingerprint sensor driver 600 transmits ultrasonic waves having a frequency corresponding to the thickness of the cover from the piezoelectric material 550. To be generated, the frequency of the driving signal supplied to the driving electrode unit 560 is increased or decreased.

In this case, since the frequency of the ultrasonic wave generated from the piezoelectric material 550 is proportional to or corresponds to the frequency of the driving signal supplied to the driving electrode unit 560, the frequency of the ultrasonic wave is changed by changing the frequency of the driving signal. The frequency can be changed.

In this case, as the thickness of the cover increases, the fingerprint sensor driver 600 may increase or decrease the frequency of the ultrasonic wave.

For example, according to the graph shown in FIG. 12, as the cover thickness increases, the acoustic pressure of the ultrasonic wave gradually decreases at all three frequencies (10 MHz, 12 MHz, and 15 MHz). Able to know.

However, as the frequency increases, it can be seen that, for example, the sound pressure of the ultrasonic waves of 15 MHz is greater than that of the ultrasonic waves of the remaining frequencies (12 MHz and 10 MHz). Accordingly, in this case, the fingerprint sensor driver 600 may increase the frequency of ultrasonic waves as the thickness of the cover increases.

However, depending on the material and characteristics of the cover, as the frequency increases, the sound pressure of the ultrasonic wave having a low frequency may be greater than that of the ultrasonic wave having a high frequency. Accordingly, in this case, the fingerprint sensor driver 600 may decrease the frequency of ultrasonic waves as the thickness of the cover increases.

In addition, in the ultrasonic waves oscillated from the piezoelectric material 550, as shown in FIG. 13, a portion S having a strong sound pressure and a portion W having a weak sound pressure are alternately generated. In this case, from the piezoelectric material 550 to the surface of the cover that the user's finger contacts (for example, the second surface 112 of the cover glass 150 or the top surface of the protective film 190 ( 191)), a portion with a strong sound pressure may reach the surface, and a portion with a weak sound pressure may reach the surface.

Therefore, when the thickness of the cover increases, the fingerprint sensor driver 600 does not simply increase or decrease the frequency of the ultrasonic wave. That is, the fingerprint sensor driver 600 selects a frequency for generating a strong sound pressure on the surface of the cover having an increased thickness as the frequency of the ultrasonic wave.

The characteristics as described above are also expressed in FIG. 12.

For example, when the thickness of the cover is 0.4mm, the sound pressure at the surface of the ultrasound at 15 MHz is greater than the sound pressures at the surface of the ultrasound at 12 MHz and 10 MHz, but the thickness of the cover is 0.45 mm The sound pressure at the surface of the 10 MHz ultrasound is greater than the sound pressures at the surface of the 12 MHz and 15 MHz ultrasound waves.

In consideration of these characteristics, in the manufacturing process of the display device according to the present invention, a frequency lookup table indicating the relationship between the frequency of the ultrasonic wave, the thickness of the cover, and the magnitude of the sound pressure as shown in FIG. 12 is the fingerprint sensor driver 600 It may be stored in the storage unit 630 of the or a separate storage unit that performs communication with the fingerprint sensor driver 600.

Therefore, when the fingerprint sensor driver 600 receives information on the thickness of the cover and a control signal for changing the frequency of the ultrasonic wave, the fingerprint sensor driver 600 selects an optimal frequency using the frequency lookup table, and selects the ultrasonic wave having the frequency. It is possible to change the frequency of the driving signal so that is generated.

Next, the fingerprint sensor driver 600 supplies the driving signal to the driving electrode unit 560 as described with reference to FIGS. 6 to 10 to provide fingerprint information corresponding to each of the fingerprint pixels 510. Generate them.

Finally, the fingerprint sensor driver 600, in particular, the fingerprint recognition unit 620 combines fingerprint information identified through the above processes to generate a single fingerprint.

The fingerprint recognition unit 620 may determine whether the fingerprint matches the reference fingerprint by comparing the fingerprint with the reference fingerprint stored in the storage unit 630.

A result of determining whether the fingerprint matches the reference fingerprint may be used in an application executed in the electronic device using the display device equipped with a frequency variable fingerprint sensor according to the present invention.

For example, when an application running on a smartphone requires user authentication using a fingerprint, the smartphone may perform user authentication according to a determination result transmitted from the fingerprint recognition unit 620.

According to the present invention as described above, even if the protective film is changed during use of the display device and the thickness of the cover is changed, the fingerprint sensing process can be normally performed.

Those skilled in the art to which the present invention pertains will appreciate that the present invention can be implemented in other specific forms without changing the technical spirit or essential features thereof. Therefore, it should be understood that the embodiments described above are illustrative in all respects and not limiting. The scope of the present invention is indicated by the claims to be described later rather than the detailed description, and all changes or modified forms derived from the meaning and scope of the claims and their equivalent concepts should be interpreted as being included in the scope of the present invention. do.

100: display panel 200: gate driver
300: data driver 400: control unit
500: fingerprint sensor 600: fingerprint sensor driver
700: touch driver 800: touch panel

Claims (10)

A display panel including a cover exposed to the outside;
A touch panel sensing a touch through the cover;
A fingerprint sensor including fingerprint pixels that perform a function as a basic unit for recognizing a fingerprint of a finger;
A fingerprint sensor driver that drives the fingerprint sensor to perform fingerprint sensing;
A touch driver that drives the touch panel to perform touch sensing; And
Including a control unit for controlling the fingerprint sensor driver and the touch driver,
The touch driver determines the thickness of the cover through the touch sensing,
The fingerprint sensor driver is a display device provided with a frequency variable fingerprint sensor for varying the frequency of ultrasonic waves used for the fingerprint sensing according to the thickness of the cover. The method of claim 1,
The fingerprint sensor,
A plurality of receiving electrodes;
N sensing lines extending along a first direction and connected to fingerprint pixels provided along the first direction;
A driving electrode unit including at least one driving electrode;
M sensing gate lines extending along a second direction different from the first direction;
Fixed voltage lines extending along the first direction;
Fingerprint common voltage lines extending along the first direction; And
A display device including a frequency variable fingerprint sensor including first to third transistors provided in the fingerprint pixel formed by any one sensing line and one sensing gate line. The method of claim 2,
A gate of the first transistor is connected to the receiving electrode, a first terminal is connected to the fixed voltage line, a second terminal is connected to a second terminal of the second transistor,
A gate of the second transistor is connected to the sensing gate line, a first terminal is connected to the sensing line, a second terminal is connected to a second terminal of the first transistor,
The gate of the third transistor is connected to another sensing gate line adjacent to the sensing gate line, a first terminal is connected to the gate of the first transistor, and a second terminal is connected to the fingerprint common voltage line. A display device equipped with a frequency-variable fingerprint sensor connected. The method of claim 1,
The cover,
It is a cover glass provided on the display panel, or
A display device having a frequency variable fingerprint sensor including a cover glass provided on the display panel and a protective film attached to the cover glass. The method of claim 1,
The touch driver determines whether or not the thickness of the cover is within a reference thickness range using the size of the touch sensing signal received from the touch panel,
When it is determined that the thickness of the cover is larger than the reference thickness range, the touch driver calculates the thickness of the cover using the size of the touch sensing signal,
The reference touch sensing signal range is a range of touch sensing signals having a size at which the fingerprint sensing can be performed normally,
The reference thickness range is a range of thicknesses of the cover corresponding to the reference touch sensing signal range. The method of claim 5,
When the touch driver determines that the size of the touch sensing signal is smaller than the range of the reference touch sensing signal and the area of the user's finger in contact with the cover is greater than or equal to a preset area, the thickness of the cover is within the reference thickness range. A display device equipped with a frequency variable fingerprint sensor that is determined to be larger. The method of claim 1,
The touch driver,
To determine the thickness of the cover irrespective of the fingerprint sensing,
When it is determined that the thickness of the cover exceeds the reference thickness range, a control signal for changing the thickness of the cover and the frequency of the ultrasonic wave is stored,
When a signal indicating that the fingerprint sensing is performed is received from the control unit, information on the thickness of the cover and the control signal are transmitted to the fingerprint sensor driver,
When the thickness of the cover and the control signal are received, the fingerprint sensor driver varies the frequency of ultrasonic waves,
The reference touch sensing signal range is a range of touch sensing signals having a size at which the fingerprint sensing can be performed normally,
The reference thickness range is a range of thicknesses of the cover corresponding to the reference touch sensing signal range. The method of claim 1,
The touch driver,
To determine the thickness of the cover irrespective of the fingerprint sensing,
When it is determined that the thickness of the cover exceeds the reference thickness range, a control signal for changing the thickness of the cover and the frequency of the ultrasonic wave is transmitted to the controller,
When a signal indicating that the fingerprint recognition process has been executed from an external system is received, the control unit transmits information on the thickness of the cover and the control signal to the fingerprint sensor driver,
When the thickness of the cover and the control signal are received, the fingerprint sensor driver varies the frequency of ultrasonic waves,
The reference touch sensing signal range is a range of touch sensing signals having a size at which the fingerprint sensing can be performed normally,
The reference thickness range is a range of thicknesses of the cover corresponding to the reference touch sensing signal range. The method of claim 1,
The touch driver,
When a signal indicating that the fingerprint recognition process has been performed is received from the control unit, it is determined whether the thickness of the cover is within a reference thickness range,
When it is determined that the thickness of the cover exceeds the reference thickness range, a control signal for changing the thickness of the cover and the frequency of the ultrasonic wave is transmitted to the fingerprint sensor driver,
When the thickness of the cover and the control signal are received, the fingerprint sensor driver varies the frequency of ultrasonic waves,
The reference touch sensing signal range is a range of touch sensing signals having a size at which the fingerprint sensing can be performed normally,
The reference thickness range is a range of thicknesses of the cover corresponding to the reference touch sensing signal range. The method of claim 1,
The fingerprint sensor driver,
Display equipped with a frequency-variable fingerprint sensor for varying the frequency of the ultrasonic wave by varying the frequency of the driving signal to be transmitted to the fingerprint sensor using a frequency lookup table indicating the relationship between the frequency of the ultrasonic wave, the thickness of the cover, and the magnitude of the sound pressure Device.

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