KR20180132496A - Operating method of optical fingerprint sensor and operating method of electronic device and display device including thereof - Google Patents

Abstract

Disclosed are a touch controller for driving a touchscreen including a fingerprint sensor, a touchscreen driving circuit, and an operating method of a touchscreen device including the same. According to an embodiment of the present invention, an operating method of a fingerprint sensor which senses a fingerprint image on the basis of reflected light reflected from the fingerprint comprises: a step of transmitting a first signal requesting light onto a display driving circuit for driving a display panel stacked on the fingerprint sensor; a step of scanning an object on the display panel on the basis of light emitted from the display panel; and a step of transmitting a second signal requesting light-off to the display driving circuit.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical fingerprint sensor, a method of operating the same, and a display device including the electronic fingerprint sensor.

TECHNICAL FIELD [0002] The present invention relates to a fingerprint sensor, and more particularly, to a method of operating an optical fingerprint sensor, an operation method of the electronic device including the fingerprint sensor, and a display device.

As wired / wireless communication technology and smart device related technology rapidly develop, a method of using a fingerprint of a user is increasing in order to perform user authentication, which is one of security methods that can securely use it. In order to optimize usability and size in mobile devices such as smart phones and tablet PCs, there is a demand for an on-display fingerprint sensor in which a fingerprint sensor is mounted on a touch screen (or display).

The problem to be solved by the technical idea of the present disclosure is to reduce the consumption current of the optical fingerprint sensor and the electronic device including the same and to improve deterioration of the pixels of the display panel which provide light to the optical fingerprint sensor.

According to an aspect of the present invention, there is provided a method of operating a fingerprint sensor that senses a fingerprint image based on reflected light reflected from a fingerprint, the method comprising: driving a display panel stacked on the fingerprint sensor Transmitting a first signal to the display driving circuit to request light on; Scanning an object on the display panel based on light emitted from the display panel; And transmitting a second signal requesting light-off to the display driving circuit.

According to an aspect of the present invention, there is provided a display device including: a display panel including a plurality of pixels; A display driving circuit for driving the display panel so that an image is displayed on the display panel; And a fingerprint sensor disposed under the display panel and sensing a fingerprint based on light emitted from at least a part of the plurality of pixels of the display panel, wherein, in a fingerprint sensing operation, It is possible to control light emission and extinction of light.

According to another aspect of the present invention, there is provided a method of operating an electronic device including a touch screen in which a fingerprint sensor is laminated, the fingerprint sensor including a display driving circuit for driving a display layer of the touch screen, Transmitting a light emission request signal to the light emitting device; Emitting the display pixels included in at least a part of the fingerprint sensing area on the touch screen based on the light emission request signal; And a step of the fingerprint sensor scanning an object on the touch screen based on light emitted from the touch screen.

According to an aspect of the present invention, there is provided a method of determining a fingerprint of a fingerprint sensor, including: obtaining a sensing signal from one direction on a pixel array; The image processor analyzing a frequency component of the sensing signal; And determining whether the object on the fingerprint sensing area is a fingerprint based on a frequency component corresponding to a first frequency band among frequency components of the sensing signal.

According to the method of operating the optical fingerprint sensor according to the embodiment of the present disclosure, the optical fingerprint sensor controls the light emission and the extinction of the light source, so that the consumption current of the fingerprint sensor can be reduced, Deterioration can be prevented. In addition, a fingerprint image is generated when the fingerprint sensor is judged to be a fingerprint by touching or in proximity to the fingerprint sensing area, and the fingerprint image is provided to the application processor for fingerprint pattern matching, thereby preventing an unnecessary fingerprint image matching operation And the consumption current of the fingerprint sensor and the application processor can be reduced.

1 shows a display device according to an embodiment of the present disclosure;
FIG. 2 is a vertical sectional view of the display panel and the fingerprint sensor of FIG. 1 taken along the line AA '.
3 is a diagram for explaining the operation of the fingerprint sensor and the display driving circuit according to the embodiment of the present disclosure.
FIG. 4 is a diagram showing the operation of the fingerprint sensor and the display drive circuit of FIG. 3 over time.
5 is a flowchart showing the operation of the fingerprint sensor and the display drive circuit according to the embodiment of the present disclosure.
6 is a diagram for explaining the operation of the fingerprint sensor and the display driving circuit according to the embodiment of the present disclosure.
7 is a flowchart showing the operation of the fingerprint sensor and the display drive circuit according to the embodiment of the present disclosure.
8 shows an embodiment of a fingerprint sensor according to an embodiment of the present disclosure.
Fig. 9 shows an embodiment of a display driving circuit according to the embodiment of the present disclosure.
Figure 10 shows a touch screen device according to an embodiment of the present disclosure;
11 shows an example of a vertical cross-sectional view of the touch screen panel and fingerprint sensor of Fig. 10 according to line AA '.
12A, 12B, and 12C are diagrams illustrating a method of receiving a sensing request signal from a touch controller by a fingerprint sensor.
13 is a block diagram illustrating a mobile device in accordance with an embodiment of the present disclosure.
Figures 14 and 15 are flow charts illustrating the operation of the configurations of the mobile device of Figure 13;
16 is a view showing a part of a person's fingerprint.
FIG. 17A is a graph showing the signal intensity of the ideal fingerprint pattern on the frequency domain, and FIG. 17B is a graph showing the signal intensity of the exemplary fingerprint sensing signal on the frequency domain. 18 is a flowchart illustrating a method for determining whether or not an object on a fingerprint sensing area according to an embodiment of the present disclosure is a fingerprint.
19A and 19B are diagrams illustrating a method of acquiring a plurality of sensing signals on a fingerprint sensing area.
20 is a diagram showing a method of acquiring a plurality of sensing signals in a plurality of directions on a fingerprint sensing area.
21 is a flowchart illustrating a method for determining whether an object on the fingerprint sensing area is a fingerprint, according to an embodiment of the present disclosure.
22 is a graph showing signal intensities of a plurality of sensing signals in the frequency domain.
23 is a flowchart illustrating a method for determining whether an object on a fingerprint sensing area is a fingerprint, according to an embodiment of the present disclosure.
24 is a diagram illustrating a smartphone according to an embodiment of the present disclosure;

Embodiments of the present disclosure are described below in connection with the accompanying drawings.

1 shows a display device according to an embodiment of the present disclosure;

A display device 1000 according to an embodiment of the present disclosure may be a smart phone, a laptop computer, a mobile phone, a tablet PC (Personal Computer), a PDA (Personal Digital Assistant), an EDA A digital still camera, a digital video camera, a portable multimedia player (PMP), a personal navigation device or a portable navigation device (PND), a handheld game console, a wearable A computer, an internet of things (IoT) device, an internet of everything (IoE) device, a drone, or an e-book. However, the present invention is not limited thereto, and the display device 1000 may be one of various kinds of electronic devices having a display function and a fingerprint recognition function.

Referring to FIG. 1, a display device 1000 may include a display panel 100, a display driving circuit 200, and a fingerprint sensor 300. The fingerprint sensor 300 may be disposed under the display panel 100. The fingerprint sensor 300 may be implemented as a semiconductor chip or a semiconductor package and may be attached to one side of the display panel 100. The display apparatus 1000 may further include other configurations. For example, when the display apparatus 1000 is a mobile apparatus, the display apparatus 1000 may further include an application processor (hereinafter referred to as an AP).

The display panel 100 includes a plurality of pixels PX arranged in a matrix, and can display an image on a frame-by-frame basis. The display panel 100 may include a liquid crystal display (LCD), an LED (light emitting diode) display, an OLED display, an AMOLED (active matrix OLED) display, an electrochromic display (ECD) (LCD), an Actuated Mirror Device (AMD), a Grating Light Valve (GLV), a Plasma Display Panel (PDP), an Electro Luminescent Display (ELD), or a Vacuum Fluorescent Display (VFD) Display. ≪ / RTI > Hereinafter, the display panel 100 will be described as an OLED (organic LED) display.

In an embodiment, the display panel 100 may further include a touch sensing array (or a touch sensing layer) and / or a force sensing array (or a force sensing layer). A display panel 100 including a touch sensing array and / or a force sensing array may be referred to as a touch screen panel. When the display panel 100 further includes a touch sensing array and / or a force sensing array, the display device 1000 may calculate the touch input based on the touch sensing signals provided from the touch sensing array and / or the force sensing array For example, a touch controller (also referred to as a touch sensing circuit) and / or a force controller.

The display driving circuit 200 can display an image on the display panel 100 by converting image data provided from an external processor, e.g., an AP, into image signals and providing the image signals to the display panel 100. [

The display driving circuit 200 may further include a display panel 100 for emitting light in all or a part of the fingerprint sensing area 101 on the display panel 100 when the fingerprint sensor 300 performs a fingerprint sensing operation, Can be driven. On the other hand, the fingerprint sensing area means an area on the x-y plane of the display panel 100 in which the fingerprint sensor 300 is disposed. Although a single fingerprint sensing area 101 is shown in FIG. 1, a plurality of fingerprint sensing areas may be disposed on the x-y plane of the display panel 100. FIG. A fingerprint sensor 300 or a pixel array of the fingerprint sensor 300, that is, a fingerprint sensing array may be disposed under the fingerprint sensing area 101. [ Pixels PX, e.g., OLED pixels included in all or a part of the fingerprint sensing area 101 may operate as a light source. Hereinafter, the light source in the present disclosure means the pixels PX included in all or a part of the fingerprint sensing area 101. [ The display driving circuit 200 can emit or extinguish a light source included in all or a part of the area of the fingerprint sensing area 101. [

The fingerprint sensor 300 may be an optical fingerprint sensor that recognizes a fingerprint by sensing light reflected by a valley between ridges and ridges of the fingerprint. The fingerprint sensor 300 can perform a fingerprint sensing operation by scanning the fingerprint sensing area based on light provided from the display panel 100. [ The fingerprint sensor 300 can generate a fingerprint image and provide the fingerprint image to the AP. In an embodiment, the fingerprint sensor 300 may determine whether an object on the fingerprint sensing area 101, i. E., An object in contact with or proximate to the fingerprint sensing area 101 is a human fingerprint. Hereinafter, in the present disclosure, an object on the fingerprint sensing area 101 or the display panel 100 refers not only to the objects touching on the fingerprint sensing area 101 or the display panel 100, but also to objects close thereto.

The fingerprint sensor 300 may control the display driving circuit 200 so that the display panel 100 emits light in part or all of the fingerprint sensing area 101 when performing the fingerprint sensing operation. The fingerprint sensor 300 may transmit a light on request signal or a light off request signal to the display driving circuit 200. The fingerprint sensor 300 may transmit partial area information together with the light emission request signal LON, for example, information on the partial area to be emitted in the fingerprint sensing area 101 to the display driving circuit 200. [

The fingerprint sensor 300 can transmit a light emission request signal LON to the display driving circuit 200 when the fingerprint scan preparation is completed. In addition, when the fingerprint scan is completed, the fingerprint sensor 300 can immediately transmit the extinction request signal LOFF to the display drive circuit 200.

The pixels PX included in the fingerprint sensing area 101 of the display panel 100 can operate as a light source that emits light of high luminance in a fingerprint sensing operation. If the time for the pixels PX to emit light is prolonged, the pixels PX may deteriorate, thereby deteriorating display performance. However, in the display device 1000 according to the embodiment of the present disclosure, under the control of the fingerprint sensor 300, only in a period in which the fingerprint sensor 300 actually scans the fingerprint, Since the pixels PX emit light, the light emission time for fingerprint sensing can be minimized.

In the embodiment, the fingerprint sensor 300 may sense only a partial area of the fingerprint sensing area 101 and determine whether the object on the fingerprint sensing area 101 is human fingerprint. For example, the fingerprint sensor 300 may generate a partial image and determine whether the generated partial image is a fingerprint image of a person. Alternatively, the fingerprint sensor 300 may determine whether the object is a human fingerprint based on the sensing signal output in at least two directions of the partial area. At this time, the display driving circuit 200 may emit only the light source included in the partial area, not all of the fingerprint sensing area 101. [ For example, the display driving circuit 200 generates a light source included in a partial area corresponding to the partial area information of the fingerprint sensing area 101 based on the partial area information received together with the light emission request signal from the fingerprint sensor 300 .

When the fingerprint sensor 300 determines that the object on the fingerprint sensing area 101 is a human fingerprint, the fingerprint sensor 300 performs a fingerprint scan operation again to generate a fingerprint image, that is, an entire fingerprint image and provide the generated fingerprint image to the AP . Accordingly, since the fingerprint sensor 300 generates the entire fingerprint image only when the fingerprint of the human being touches (or is close to) the fingerprint sensing area 101, the pixels PX of the fingerprint sensing area 101 emit light And the consumption current of the fingerprint sensor 300 can be reduced.

Also, the AP compares the pattern of the received fingerprint image with the fingerprint pattern of the user to determine whether the fingerprint image matches the fingerprint image. If the fingerprint image is not a fingerprint image of a person, the pattern comparison operation can be removed. .

2 is a vertical cross-sectional view of the display panel and the fingerprint sensor of Fig. 1 taken along line A-A '. Referring to FIG. 2, the display panel 100 may include a display layer 110, a backplane 120, and a cover glass 130 including a plurality of pixels PX, e.g., OLED pixels. The display panel 100 may further include other layers. For example, when the display panel 100 is implemented as a touch screen panel, the display panel 100 may further include a touch sensing layer including a plurality of touch sensing units and / or a plurality of force sensing units .

The light from the plurality of pixels PX is transmitted to the fingerprint of the user and the fingerprint of the user is detected when the fingerprint FP of the user touches the cover glass 130 of the display panel 100 or approaches the cover glass 130, The reflected and reflected light can be transmitted to the fingerprint sensor 300 through the backplane 120.

The fingerprint sensor 300 may be implemented as a semiconductor chip or a semiconductor package and may be attached to one surface of the display panel 100, for example, a lower surface of the display panel 100. The fingerprint sensor 300 may include a pixel array 310 and a fingerprint controller 320.

The pixel array 310 may include a plurality of sensing pixels, and the plurality of sensing pixels may each include a photoelectric conversion element (e.g., a photodiode, a phototransistor, a photogate, and a pinned photodiode, etc.). Each of the plurality of sensing pixels may sense light reflected by different regions of the fingerprint and may generate an electrical signal corresponding to the sensed light. Each sensing pixel may generate an electrical signal corresponding to ridge reflected light of the fingerprint or may generate an electrical signal corresponding to light reflected on a valley between ridges. The amount of light sensed in each sensing pixel may vary depending on the type of the fingerprint reflected by the light, and an electric signal having different levels may be generated depending on the amount of sensed light.

The fingerprint controller 320 can receive electrical signals, i.e., analog sensing signals, provided from a plurality of sensing pixels of the pixel array 310 and generate a fingerprint image through a processing operation on the analog sensing signals.

The pixel array 310 and the fingerprint controller 320 may be formed on different discrete wafers (or semiconductor substrates) where the pixel array 310 and the fingerprint controller 320 are classified as separate chips . In an embodiment, the semiconductor chip on which the pixel array 310 is implemented may be stacked on the semiconductor chip on which the fingerprint controller 320 is implemented. Alternatively, as another embodiment, the pixel array 310 and the fingerprint controller 320 may be implemented in one semiconductor chip.

The fingerprint sensor 300 may further include a light collecting part 330. The reflected light having passed through the backplane 120 of the display panel 100 may be incident on the pixel array 310 through the condensing unit 330. The light collecting part 330 may be embodied as a pinhole mask including a plurality of pinholes, an ultra-thin lens, or the like.

In an embodiment, the light collecting portion 330 may be stacked on the pixel array 310 or may be stacked in layers on one or more layers constituting the pixel array 310 in the process for implementing the pixel array 310 . In other words, the light collecting part 330 and the pixel array 310 may be integrally formed.

FIG. 3 is a diagram for explaining the operation of the fingerprint sensor and the display drive circuit according to the embodiment of the present disclosure, and FIG. 4 is a diagram showing the operation of the fingerprint sensor and the display drive circuit of FIG. 3 over time.

Referring to FIGS. 3 and 4, the fingerprint sensor 300 receives a fingerprint sensing request signal SREQ from the outside and can prepare for fingerprint scanning. The fingerprint sensor 300 may be set so that the internal circuit can normally perform the fingerprint sensing operation before the fingerprint scan, for example, during the PR interval. When the fingerprint scan preparation is completed, the fingerprint sensor 300 can transmit a light emission request signal LON to the display drive circuit 200. [ The display driving circuit 200 may drive the display panel 100 in response to the light emission request signal LON. The display driving circuit 200 can emit light at a high luminance by providing the light sources included in all or a part of the fingerprint sensing area 101 with a signal VH indicating a high gradation.

At this time, the fingerprint sensor 300 may perform a fingerprint scan operation. The fingerprint sensor 300 may receive electrical signals, i.e., analog sensing signals, provided from a plurality of sensing pixels corresponding to all or a portion of the fingerprint sensing area 101. [ The fingerprint sensor 300 may convert the analog sensing signals into a digital sensing signal.

When the fingerprint scan operation is completed, the fingerprint sensor 300 can transmit the extinction request signal LOFF to the display drive circuit 200. In response to the extinction request signal LOFF, the display driving circuit 200 can stop the driving of the display panel 100, thereby light-extinguishing the light sources.

The fingerprint sensor 300 may convert the received analog sensing signals to digital sensing signals after the fingerprint scan interval, e.g., during the SP interval, and generate a fingerprint image or a partial image based on the converted signals, i.e., the sensing signals . Or the fingerprint sensor 300 may analyze the frequency components of the sensing signals or the partial image.

When the light emission request signal LON and / or the extinction request signal LOFF are provided from an apparatus other than the fingerprint sensor 300, for example, AP, the light emission request signal LON and / / RTI > can be transmitted to the display drive circuit 200. The < / RTI > The display driving circuit 200 may cause the light sources to emit light in a section other than the section in which the fingerprint sensor 300 scans the fingerprint.

However, according to the operations of the fingerprint sensor 300 and the display drive circuit 200 of the display device (1000 of FIG. 1) according to the embodiment of the present disclosure described above, in the fingerprint sensing operation, The pixels PX of the fingerprint sensing area 101 of the display panel 100 can emit light only during a period in which the fingerprint sensor 300 actually scans the fingerprint by controlling the driving circuit 200. [ Accordingly, waste of the current consumption of the display device 1000 is prevented, and the light emission time of the light sources for fingerprint sensing can be minimized.

5 is a flowchart showing the operation of the fingerprint sensor and the display drive circuit according to the embodiment of the present disclosure. 5 shows a case where the fingerprint sensor 300 scans the entire fingerprint sensing area.

Referring to FIG. 5, the fingerprint sensor 300 may receive a fingerprint sensing request signal (S110). The fingerprint sensor 300 may receive a fingerprint sensing request signal from an external processor, a touch controller, or a sensor hub.

The fingerprint sensor 300 may set an internal circuit (S120). Accordingly, the fingerprint sensor 300 can prepare for fingerprint scan. The bias of an internal circuit, for example, an analog circuit, may be set.

Thereafter, the entire fingerprint sensing operation, that is, the entire fingerprint sensing area, may be performed (S130). When the fingerprint sensor 300 is ready for the fingerprint scan, the fingerprint sensor 300 can transmit a light emission request signal to the display drive circuit 200 (S131). The display driving circuit 200 may emit a light source in the fingerprint sensing area in response to the light emission request signal in step S133. When the light source emits light, the fingerprint sensor 300 may perform a fingerprint scan operation in step S132.

When the fingerprint scan operation is completed, the fingerprint sensor 300 can transmit the extinction request signal to the display drive circuit 200 (S134). The display driving circuit 200 may turn off the light source in the fingerprint sensing area in response to the extinction request signal (S136).

After transmitting the extinction request signal or simultaneously transmitting the extinction request signal, the fingerprint sensor 300 may process the sensed signals, for example, image processing to generate a fingerprint image (S135). The fingerprint sensor 300 may output a fingerprint sensing completion signal or a generated fingerprint image (S140). For example, the fingerprint sensor 300 may transmit a fingerprint sensing completion signal or a generated fingerprint image to the AP.

6 is a diagram for explaining the operation of the fingerprint sensor and the display driving circuit according to the embodiment of the present disclosure. 6 shows an operation in which the fingerprint sensor 300 scans a partial area of the fingerprint sensing area 101. FIG.

The operations of the fingerprint sensor 300 and the display drive circuit 200 of FIG. 6 are similar to those of the fingerprint sensor 300 and the display drive circuit 200 described with reference to FIG. However, the fingerprint sensor 300 may transmit the partial area information PAIF to the display driving circuit 200 together with the light emission request signal LON. The display driving circuit 200 can emit light in the partial area PA corresponding to the partial area information PAIF in the fingerprint sensing area 101. [ The fingerprint sensor 300 can perform a fingerprint scan operation on the partial area PA rather than the entire fingerprint sensing area 101. [

In the embodiment, the partial area information PAIF may include an address for the partial area PA. Or a plurality of partial areas PA are preset, and the partial area information PAIF may include an index indicating one of the plurality of partial areas PA.

In another embodiment, each time a plurality of partial areas PA are set in advance and the light emission request signal LON is provided to the display driving circuit 200, One can be selected.

7 is a flowchart showing the operation of the fingerprint sensor and the display drive circuit according to the embodiment of the present disclosure. 7 shows a case where the fingerprint sensor 300 scans a part of the fingerprint sensing area, that is, a partial area (PA in Fig. 6).

Referring to FIG. 7, the fingerprint sensor 300 receives a fingerprint sensing request signal (S210) and sets a finger sensor (S220). Steps S210 and S220 are similar to steps S110 and S120 of FIG.

Subsequently, partial fingerprint sensing, that is, an operation of scanning a partial area of the fingerprint sensing area may be performed (S130). When the fingerprint sensor 300 is ready for the fingerprint scan, the fingerprint sensor 300 may transmit the light emission request signal and the partial area information to the display driving circuit 200 (S231). In response to the light emission request signal, the display driving circuit 200 may emit light in a partial region corresponding to the partial region information in the fingerprint sensing region (S233). When the light source in the partial region emits light, the fingerprint sensor 300 A fingerprint scan operation for the partial area can be performed (S232).

When the fingerprint scan operation is completed, the fingerprint sensor 300 can transmit the extinction request signal to the display drive circuit 200 (S234). The display driving circuit 200 may turn off the light source of the partial area in response to the extinction request signal (S236).

After transmitting the extinction request signal or simultaneously transmitting the extinction request signal, the fingerprint sensor 300 may process (e.g., image) the sensed signals to generate a partial image (S235).

The fingerprint sensor 300 may determine whether the partial image is a fingerprint image (S240). For example, the fingerprint sensor 235 may determine whether the partial image is a fingerprint image based on a frequency component of signals extracted from at least two directions of the partial image. That is, the fingerprint sensor 300 can determine whether the object on the fingerprint sensing area is a human fingerprint. As another example, the fingerprint sensor 300 may determine whether the object on the fingerprint sensing area is a human fingerprint based on the frequency components of the sensing signals in at least two directions. This will be described later in detail with reference to FIG. 16 to FIG.

If it is determined that the partial image is a fingerprint image, the fingerprint sensor 300 may perform a full fingerprint sensing to obtain a complete fingerprint image (S260). That is, if the fingerprint sensor 300 determines that the object is a human fingerprint, the fingerprint sensor 300 can perform full fingerprint sensing. The full fingerprint sensing may be performed according to step S130 of FIG. The fingerprint sensor 300 can acquire a fingerprint image and transmit the acquired fingerprint image to the processor. If it is determined that the partial image is not a fingerprint image, the fingerprint sensor 300 may discard the partial image (S250).

Accordingly, the fingerprint sensor 300 scans the partial area of the fingerprint sensing area, and first determines whether the object in contact with the fingerprint sensing area is a fingerprint of a person. Then, only when it is determined that the fingerprint is a human fingerprint, To acquire a fingerprint image, and to provide the obtained fingerprint image to the AP for fingerprint pattern matching.

8 shows an example of a fingerprint sensor according to an embodiment of the present disclosure.

Referring to FIG. 8, the fingerprint sensor 300a may include a fingerprint controller 320 and a condenser 330 of the pixel array 310. FIG. The description of the pixel array 310, the fingerprint controller 320 and the condenser 330 described with reference to FIG. 2 is the same as that of the pixel array 310, the fingerprint controller 320 and the condenser 330 according to the present embodiment Can be applied.

The light collecting section 330 can collect or receive reflected light L reflected by an object, such as a fingerprint. The reflected light L may be incident on the pixel array 310 through the light collecting part 330. The light collecting part 330 may be embodied as a pinhole mask including a plurality of pinholes, an ultra-thin lens, or the like.

The pixel array 310 may include a plurality of sensing pixels, each sensing a reflected light L and generating an electrical signal corresponding to the sensed light, i.e., an analog sensing signal.

The fingerprint controller 320 may receive the analog sensing signals provided from the plurality of sensing pixels of the pixel array 310 and generate a fingerprint image or a partial image through a processing operation on the analog sensing signals.

The fingerprint controller 320 may include a sensing circuit 321, a controller 322, a signal processor 323, a buffer 324, a first interface 325 and a second interface 326.

The sensing circuit 321 may receive analog sensing signals from the pixel array 310 and convert the received analog sensing signals into digital sensing signals. The sensing circuit 321 may include a plurality of analog-to-digital converters, and each of the plurality of analog-to-digital converters may convert an analog sensing signal provided from a corresponding one of the channels connected to the pixel array 310 into a digital sensing signal Can be converted. The digitally converted sensing signal may be provided to the signal processor 323 or temporarily stored in the buffer 334 and then provided to the signal processor 323. [

The buffer 324 may temporarily store a sensing signal provided from the sensing circuit 331. [ The buffer 324 may also store various kinds of setting values, algorithms, and the like set for the operation of the fingerprint sensor 300a. The buffer 324 may be implemented as at least one of a volatile memory or a nonvolatile memory. The non-volatile memory may be a ROM, a PROM, an EPROM, an EEPROM, a flash memory, a phase-change RAM (PRAM), a magnetic RAM (MRAM) RRAM (Resistive RAM), FRAM (Ferroelectric RAM), and the like. The volatile memory includes a dynamic random access memory (DRAM), a static RAM (SRAM), a synchronous DRAM (SDRAM), a phase change RAM (PRAM), a magnetic RAM (MRAM), a resistive RAM (RRAM), a ferroelectric RAM .

The signal processor 323 may generate a fingerprint image or a partial image based on the sensing signals. The signal processor 323 can also analyze the frequency components of the sensing signals or the sensing signals included in the partial image. For example, the signal processor 323 may extract a signal of a specific frequency band from the sensing signals. For this purpose, the signal processor 323 may include a frequency analysis filter 323_1.

The frequency analysis filter 323_1 may include, for example, a fast Fourier transform (FFT) filter, a digital IIR (Infinite Impulse Response) filter, a band pass filter, and the like. However, it is not limited thereto, and the frequency analysis filter 323_1 may include various kinds of digital filters.

The controller 322 can control the overall operation of the fingerprint sensor 300a. The controller 322 can control the driving timing of the sensing circuit 321. [ The controller 322 may transmit the light emission request signal and / or the extinction request signal to the display driving circuit 200 through the second interface 326. [ The fingerprint sensor 300a may operate in synchronism with the display driving circuit 200 and the controller 322 may supply a synchronizing signal to the display driving circuit 200 via the second interface 326, And may transmit a synchronous signal and / or a horizontal synchronous signal, or may receive a synchronous signal from the display driving circuit 200.

When the fingerprint sensor 300a performs the entire fingerprint sensing operation, the controller 322 can transmit the fingerprint image provided from the signal processor 323 to the AP through the first interface 325. [

When the fingerprint sensor 300a performs the partial fingerprint sensing operation, the controller 322 can determine whether the object is a human fingerprint based on the frequency characteristics of the sensing signals provided from the signal processor 323. In an embodiment, the controller 322 may determine whether the partial image is a fingerprint image. If it is determined that the object is a human fingerprint, the controller 322 can control the fingerprint sensor 300a to perform a full fingerprint sensing operation. In an embodiment, if it is determined that the partial image is not a fingerprint image, the controller 322 may discard the partial image.

The first interface 325 is a communication circuit for the fingerprint sensor 300a to communicate with an external processor such as an AP and the second interface 326 is a communication circuit for communicating with the display drive circuit 200 for the fingerprint sensor 300a Circuit. In an embodiment, the first interface 325 and the second interface 326 may be implemented as a single circuit.

The first interface 325 and the second interface 326 may be homogeneous or heterogeneous interfaces. The first interface 325 and the second interface 326 may be respectively connected to an RGB interface, a CPU interface, a serial interface, a mobile display digital interface (MDDI), an inter integrated circuit (I2C) interface, a serial phyripheral interface (SPI) , A microcontroller unit (MCU) interface, a mobile industry processor interface (MIPI), an embedded displayport (eDP) interface, a D-subminiature, an optical interface, a D- or a high definition multimedia interface. Additionally or alternatively, the first interface 325 and the second interface 326 may be, for example, a mobile high-definition link (MHL) interface, a secure digital (SD) card / multi- and an infrared data association standard interface. The first interface 325 and the second interface 326 may include various serial or parallel interfaces.

In an embodiment, the second interface 326 may be a simple input / output pin (or pad). For example, the second interface 326 may be implemented as a general purpose I / O (GPIO).

Fig. 9 shows an example of a display drive circuit according to the embodiment of the present disclosure. For convenience of explanation, the display panel 100 is also shown.

Referring to FIG. 9, the display driving circuit 200a may include a data driver 210, a scan driver 220, a control logic 230, a first interface 240, and a second interface 250. Referring to FIG. The display driving circuit 200a may further include a voltage generating circuit, a video signal processing circuit, and the like.

The scan driver 220 supplies an ON signal to the scan lines SL1 to SLn of the display panel 100 in response to the first control signal CTRL1 provided from the control logic 230, SL1 to SLn) can be selected. In the display operation, the scan driver 220 can sequentially select the scan lines SL1 to SLn of the display panel 100. [ In the fingerprint sensing operation, the scan driver 220 may sequentially or simultaneously select some of the scan lines SL1 to SLn of the display panel 100, for example, the scan lines corresponding to the light emitting area.

The data driver 210 converts the image data DATA into image signals (e.g., gradation voltages corresponding to the respective pixel data of the data DATA) in response to the second control signal CTRL2, Signals to the data lines DL1 to DLm. When the pixels PX operate as a light source for the fingerprint sensing operation, the data driver 210 outputs image signals representing the highest gradation to some of the data lines DL1 to DLm, for example, Lt; / RTI >

The control logic 230 can control the overall operation of the display driving circuit 200a. The control logic 230 may control the driving timing of the data driver 210 and the scan driver 220, and may be referred to as a timing controller. The control logic 230 receives image data and control signals (e.g., a vertical synchronization signal, a horizontal synchronization signal, a clock signal, etc.) provided from an external processor, e.g., an AP, through the first interface 240, And generate a first control signal CTRL1 and a second control signal CTRL2 for controlling the data driver 210 and the scan driver 220 based on the signals. In addition, the control logic 230 may convert the format of the video data according to the interface specification with the data driver 210, and may transmit the converted video data (DATA) to the data driver 210.

The control logic 230 also receives the light emission request signal and the extinction request signal from the fingerprint sensor 300 via the second interface 250 and, in response to the light emission request signal, That is, the pixels PX included in part or all of the fingerprint sensing area, and in response to the extinction request signal, the light sources can be extinguished.

The control logic 230 receives a synchronization signal from the fingerprint sensor 300 via the second interface 250 or transmits a synchronization signal to the fingerprint sensor 300 and transmits the synchronization signal to the first control Generates the signal CTRL1 and the second control signal CTRL2 and supplies the operation timing of the data driver 210 and the scan driver 220 based on the generated first control signal CTRL1 and the second control signal CTRL2 Can be controlled. The data driver 210 and the scan driver 220 operate in response to the first control signal CTRL1 and the second control signal CTRL2 so that a light source of part or all of the fingerprint sensing area can emit or quench.

The first interface 240 is a communication circuit for communicating with an external processor, for example, an AP, and the second interface 250 is a communication circuit for the display driving circuit 200a to communicate with the fingerprint sensor 300 May be a communication circuit. In an embodiment, the first interface 24 and the second interface 250 may be implemented as a single circuit. The first interface 24 and the second interface 250 may each include one of the various interfaces described above with reference to FIG. In an embodiment, the second interface 250 may be a simple input / output pin (or pad). For example, the second interface 250 may be implemented as a general purpose I / O (GPIO).

Figure 10 shows a touch screen device according to an embodiment of the present disclosure;

The touch screen device 2000 may be one of various types of electronic devices having a display function, a touch recognition function, and a fingerprint recognition function. For example, the touch screen device 2000 may be one of the various electronic devices described above with reference to FIG.

The touch screen device 2000 may include a touch screen panel 2100, a touch screen drive circuit 2200, and a fingerprint sensor 300. Although not shown in FIG. 10, the touch screen device 2000 may further include an AP.

The touch screen panel 2100 can display an image and sense a touch input generated on the touch screen panel 2100. The touch screen panel 2100 may include a display layer and a touch sensor layer, which may be disposed on top of the display layer, or formed integrally with the display layer.

11 shows an example of a vertical cross-sectional view of the touch screen panel and the fingerprint sensor of Fig. 10 according to the line A-A '. The vertical cross-sectional view of Figure 11 is similar to the vertical cross-sectional view of Figure 2. However, the touch screen panel 2100 may further include a touch sensor layer 140. As shown in FIG. 12, the touch sensor layer 140 may be interposed between the display layer 110 and the cover glass 130. However, the present invention is not limited thereto, and the touch sensor layer 140 may be formed integrally with the pixels PX.

The touch sensor layer 140 may include a touch sensor, and the touch sensor may include a plurality of touch sensing units arranged in a matrix form. The touch sensor may sense the touch input on the touch screen panel 2100 and generate a sensing signal, e.g., a touch sensing signal. The touch sensor can provide a touch sensing signal to the touch controller 400. [

The touch sensor can be implemented by a capacitive sensor. The touch sensor 20 may include touch sensing units arranged in a matrix on the x-y plane. The touch sensing units may be implemented as sensor electrodes disposed within the touch sensing layer 140. The sensor electrode may be formed of a transparent conductive material such as ITO (indium tin oxide), IZO (indium zinc oxide), or ITZO (indium tin zinc oxide). However, the present invention is not limited thereto, and the touch sensor may be implemented by a variety of sensors such as a resistive overlay, a surface acoustic wave, an infrared, a surface acoustic wave, and an inductive .

In an embodiment, the touch screen panel 2100 may sense a force of a touch input occurring on the touch screen panel 2100. The touch screen panel 2100 may further include a force sensor. The force sensor may include a plurality of force sensing units arranged in a matrix, and the plurality of force sensing units may be arranged in a matrix form or a plurality of force sensing electrodes arranged in rows and columns. In an embodiment, the touch sensor and the force sensor may share a sensing electrode.

The touch screen drive circuit 2200 may include a display drive circuit 200 and a touch controller 400. The display drive circuit 200 and the touch controller 400 may be formed on separate semiconductor chips. Or the display drive circuit 200 and the touch controller 400 may be integrated in one semiconductor chip.

The display driving circuit 200 displays an image on the display layer 110 of the touch screen panel 2100 or the touch screen panel 2100 or when the fingerprint sensor 300 detects an image on the fingerprint sensing area 101, The light source of FIG. The operation of the display drive circuit 200 described with reference to Fig. 1 can be applied to the display drive circuit 200 of this embodiment. A duplicate description will be omitted.

The touch controller 400 provides a driving signal to the touch sensing layer 140 and processes the sensing signal received from the touch sensing layer 140 based on the driving signal to calculate the touch input occurrence and the touch coordinates have.

Meanwhile, when the touch screen device 2000 is operated in the low power mode but is set to perform the touch sensing function (for example, always on touch mode), the touch controller 400 controls the touch input / When the above-described touch force is generated, the fingerprint sensor 300 can directly or indirectly provide the sensing request signal SREQ.

The fingerprint sensor 300 is switched from a low power mode, for example, from a sleep mode to an operation mode, for example, a normal operation mode in response to a sensing request signal SREQ provided from the touch controller 400, and can perform a fingerprint sensing operation.

The fingerprint sensor 300 transmits a light emission request signal LON to the display driving circuit 200 after the fingerprint scan preparation is completed and then outputs a light extinction request signal LOFF to the display driving circuit 200, Can be transmitted.

The operations of the fingerprint sensor 300 and the display driving circuit 200 are the same as those described above with reference to FIG. 1, and a duplicate description will be omitted.

12A, 12B and 12C are diagrams for explaining how a fingerprint sensor receives a sensing request signal SREQ from a touch controller.

Referring to FIG. 12A, the fingerprint sensor 300 may receive a sensing request signal SREQ directly from the touch controller 400. FIG. The fingerprint sensor 300 and the touch controller 400 may each include an interface for direct communication.

Referring to FIGS. 12B and 12C, the fingerprint sensor 300 can indirectly receive the sensing request signal SREQ from the touch controller 400. FIG.

Referring to FIG. 12B, the fingerprint sensor 300 and the touch controller 400 may communicate with an external processor, e.g., the AP 500, respectively. The touch controller 400 may transmit a sensing request signal SREQ to the fingerprint sensor 300 through the AP 500. [ On the other hand, when the touch screen device 2000 (FIG. 10) operates in the low power mode, the AP 500 may be in a sleep state (or a low power state). However, the AP 500 may have a low power region 510 and the low power region 510 may perform all or some of the operations when the AP 500 is in the sleep state. The low power region 510 may provide the fingerprint sensor 300 with a sensing request signal SREQ received from the touch controller 400. [

Referring to FIG. 12C, the fingerprint sensor 300 and the touch controller 400 are respectively connected to the sensor hub 600 and can communicate with the AP 500 through the sensor hub 600.

The sensor hub 600 is connected between the various sensors and the AP 500 and provides the AP 500 with data, information and notifications received from various sensors, and transmits control signals provided from the AP 500 Can be transmitted to the sensors.

12C, the sensor hub 600 may provide the AP 500 with finger coordinates provided from the touch controller 400 and a fingerprint image provided from the fingerprint sensor 300. The touch controller 400 may transmit the sensing request signal SREQ to the fingerprint sensor 300 through the sensor hub 600. [

12C, the sensor hub 600 is shown as being separate from the AP 500, but the present invention is not limited thereto, and the sensor hub 600 may be included in the AP 500. FIG.

13 is a block diagram illustrating a mobile device in accordance with an embodiment of the present disclosure. The mobile device may be implemented as the touch screen device of FIG. 10, and may include a touch screen panel.

The mobile device 3000 may include a display drive circuit 200, a fingerprint sensor 300, a touch controller 400, and an AP 500. The touch screen panel will be omitted. The description of the display driving circuit 200, the fingerprint sensor 300, the touch controller 400, and the AP 500 with reference to Figs. 1 to 13 can be applied to this embodiment.

The AP 500 controls the overall operation of the mobile device 3000. The AP 500 can communicate with the display driving circuit 200, the fingerprint sensor 300 and the touch controller 400 and controls the display driving circuit 200, the fingerprint sensor 300 and the touch controller 400 .

Specifically, in the display operation, the AP 500 can provide the image data (IDATA) to the display drive circuit 200. In the touch sensing operation, the AP 500 can control the mobile device 3000 to perform a desired operation based on the touch coordinates (Txy) provided from the touch controller 400. For example, when the user interface displayed on the touch screen panel includes icons for various kinds of applications, the AP 500 can execute an application or a program corresponding to the icon corresponding to the touch coordinate (Txy).

In the fingerprint sensing operation, the AP 500 receives the fingerprint image (FPI) provided from the fingerprint sensor 300 and performs user authentication based on the fingerprint image (FPI). For example, the AP 500 may obtain a fingerprint pattern from a fingerprint image (FPI), and compare the obtained fingerprint pattern with a predetermined user fingerprint pattern to determine whether the fingerprint pattern is matched. If the fingerprint pattern is matched, the AP 500 determines that the user authentication is successful and can perform various operations according to the user authentication.

For example, when the mobile device is locked, if the user authentication is successful, the AP 500 can switch the mobile device to the unlocked state. Alternatively, the AP 500 may access the security data or perform the security data processing operation when the user who has successfully authenticated the user wants to use the security data.

Meanwhile, the AP 500 includes a security area for processing security data, for example, important data, and a fingerprint image (FPI) can be received in the security area. AP 500 may include a Rich Execution Environment (REE) and a Trusted Execution Environment (TEE), and a security environment may be applied to the security zone TZ. Security areas TZ and other areas, such as general areas, may be implemented in a physically separate form, in a software separated form, or in a form using both physical and software separation.

In the fingerprint sensing operation, the fingerprint sensor 300 can control the display driving circuit 200. The fingerprint sensor 300 may transmit the light emission request signal LON and / or the extinction request signal LOFF to the display driving circuit 200. [ The display driving circuit 200 is responsive to the light emission request signal LON and / or the extinction request signal LOFF received from the fingerprint sensor 300 to generate the fingerprint sensing area 101 on the touch screen panel 2100 (Fig. 10) The light sources included in all or a part of the light sources can be lighted or extinguished.

The fingerprint sensor 300 receives the fingerprint sensing command from the AP 500 and can operate in response to the fingerprint sensing command. The fingerprint sensor 300 can provide a fingerprint sensing completion signal and a fingerprint image (FPI) to the AP 500 when the fingerprint sensing operation is completed.

On the other hand, when the mobile device 3000 is operating in the low power mode, the AP 500 may be in a sleep mode (or low power mode). The AP 500 may stop operating or only a partial area of the AP 500 may operate.

At this time, if a touch input is detected on the touch screen panel, the fingerprint sensor 300 can perform a fingerprint sensing operation. The touch controller 400 senses the touch input generated on the touch screen panel and provides the sensing request signal SREQ to the fingerprint sensor 300. [ 14, the touch controller 400 directly provides the sensing request signal SREQ to the fingerprint sensor 300. However, the present invention is not limited thereto. As described with reference to FIGS. 13B and 13C, the touch controller 400 400 may indirectly provide the fingerprint sensor 300 with a sensing request signal SREQ.

Figures 14 and 15 are flow charts illustrating the operation of the configurations of the mobile device of Figure 13;

A case where the mobile device 3000 operates in a low-power mode from a locked state will be described as an example.

14, the AP 500 and the fingerprint sensor 300 are in a sleep mode (or a low power mode), the touch controller 400 is in an operation mode The display drive circuit 200 can operate in the low power operation mode. For example, the display driving circuit 200 may display an image only on a partial area on the touch screen panel. This low power mode may be referred to as AOD (Always On Display) mode, or AOF (Always On Touch) mode. In an embodiment, the touch controller 400 may also operate in a low power mode of operation and may sense touch input occurring in the partial area or some other area on the touch screen panel.

The touch controller 400 can continuously determine whether or not a touch input has occurred by performing touch sensing at predetermined preset intervals (S211).

When the touch input is generated, the touch controller 400 can transmit a fingerprint sensing request signal to the fingerprint sensor 300 (S222). When the mobile device 3000 is in the locked state, even if a touch input occurs, user authentication must be performed so that the mobile device 3000 can be switched from the low power mode to the normal operation mode. Accordingly, the touch controller 400 may transmit a touch fingerprint sensing request signal to the fingerprint sensor 300 for user authentication.

In response to the fingerprint sensing request signal, the fingerprint sensor 300 is woken up and ready for fingerprint scanning (S231). In other words, the fingerprint sensor 300 is switched to the operation mode, and can prepare for the fingerprint sensing operation. The fingerprint sensor 300 can be set so that the internal circuit operates normally.

When the fingerprint scan preparation is completed, the fingerprint sensor 300 and the display drive circuit 200 can perform the full fingerprint sensing (S241). As described with reference to step S130 of FIG. 5, full fingerprint sensing may be performed. The fingerprint sensor 300 may scan the entire fingerprint sensing area to generate a fingerprint image, and may transmit the fingerprint image to the AP 500 (S251).

When the fingerprint image is received, the AP 500 can be switched from the sleep mode (or the low power mode) to the operation mode and perform the fingerprint matching operation (S261). If the pattern of the received fingerprint image matches the pattern of the predetermined user fingerprint, the mobile device 3000 can be switched to the operation mode.

15, when the mobile device 3000 operates in the low power mode at step S310, the AP 500 and the fingerprint sensor 300 are in the sleep mode (or low power mode), the touch controller 400 is in the operation mode The display drive circuit 200 can operate in the low power operation mode.

The touch controller 400 can continuously determine whether or not a touch input has occurred by performing touch sensing at predetermined preset intervals (S311). When a touch input occurs, the touch controller 400 transmits a fingerprint sensing request signal To the fingerprint sensor 300 (S322).

The fingerprint sensor 300 can be switched from the sleep mode to the operation mode in response to the fingerprint sensing request signal, and can prepare for fingerprint scanning (S331).

When the fingerprint scan preparation is completed, the fingerprint sensor 300 and the display drive circuit 200 can perform partial fingerprint sensing (S341). As described with reference to step S230 in FIG. 7, partial fingerprint sensing can be performed. The fingerprint sensor 300 may scan a partial area of the fingerprint sensing area.

The fingerprint sensor 300 can determine whether the touch input is a fingerprint (S351). For example, the fingerprint sensor 300 may determine whether the touch input is a human fingerprint based on a partial image or sensing signals generated by scanning a partial area of the fingerprint sensing area. For example, the fingerprint sensor 300 may analyze the frequency components of at least two sensing signals included in the sensing signals or the partial image, and may determine whether the touch input is a human fingerprint based on the frequency components. The mobile device 3000 can continue to operate in the low power mode. In an embodiment, the fingerprint sensor 300 may discard the partial image.

If it is determined that the touch input is a fingerprint of a person, the fingerprint sensor 300 may transmit a wake-up signal to the AP 500 (S381). Accordingly, the AP 500 can be switched from the sleep mode (or the low power mode) to the operation mode.

In addition, the fingerprint sensor 300 can perform full fingerprint sensing (S382). The fingerprint sensor 300 can acquire a fingerprint image. The fingerprint sensor 300 can transmit the fingerprint image to the AP 500 (S391).

The AP 500 can perform a fingerprint matching operation based on the received fingerprint image. The AP 500 can compare the fingerprint pattern of the received fingerprint image with the fingerprint pattern of the predetermined user fingerprint. If the fingerprint patterns match, the AP 500 determines that the user authentication is successful, and the mobile device 3000 can be switched to the operation mode.

According to the embodiment of the present disclosure, when the touch input is generated, the mobile device 3000 immediately acquires the fingerprint image and determines whether the touch input is a fingerprint, instead of performing the fingerprint matching. If the touch input is a fingerprint , A fingerprint image can be acquired, and fingerprint matching can be performed based on the acquired fingerprint image. Accordingly, in the case where the user's fingerprint does not touch the touch screen of the mobile device 3000 but the other object, for example, another body part, an object of the user, or the like is erroneously contacted, Can be prevented from switching from the sleep mode (or the low power mode) to the operation mode. Accordingly, the power consumption of the mobile device 3000 can be reduced.

Hereinafter, a method for determining whether or not the fingerprint sensor 300 is a fingerprint of a human being will be described in detail.

16 is a view showing a part of a person's fingerprint.

는 수학식 1과 같이 나타낼 수 있다. Referring to FIG. 16, a fingerprint of a human consists of a ridge (RL) as a bulge and a ridge (VA) between ridges, and a distance between adjacent ridges (RL) may be approximately 250 to 260 micrometers. That is, 1.52 to 4 ridges (RL) may be arranged per 1 mm. As shown, when the fingerprint pattern is obtained in a direction perpendicular to the pattern formed by the ridgeline RL and the valley VA, the spatial frequency f of the fingerprint pattern may be approximately 1.5 KHz to 4 KHz (kilohertz). When the fingerprint sensor 300 acquires an image point in k millimeter intervals, that is, the sensing circuit (321 in FIG. 8) receives the analog sensing signal in k mm intervals from the pixel array (310 in FIG. 8) When a signal is converted into a digital sensing signal, the normal spatial frequency of the digitized fingerprint pattern

Can be expressed by Equation (1).

를 나타내고 세로축은 신호 세기를 나타낸다. FIG. 17A is a graph showing the signal intensity of the ideal fingerprint pattern on the frequency domain, and FIG. 17B is a graph showing the signal intensity of the exemplary fingerprint sensing signal on the frequency domain. In Figs. 17A and 17B, the horizontal axis indicates the normal spatial frequency

And the vertical axis represents the signal intensity.

는 제1 주파수(f1) 및 제2 주파수(f2) 사이에 분포할 수 있다. 예컨대, 제1 주파수(f1)는 대략 k*1.5Khz이고, 제2 주파수(f2)는 대략 k*4Khz일 수 있다. 제1 주파수(f1) 내지 제2 주파수(f2) 사이의 주파수 영역이 지문 공간 주파수 대역(FSB)으로 지칭될 수 있다. Referring to FIG. 17A, the normal spatial frequency of the ideal fingerprint pattern

May be distributed between the first frequency f1 and the second frequency f2. For example, the first frequency f1 may be approximately k * 1.5 KHz and the second frequency f2 may be approximately k * 4 KHz. The frequency domain between the first frequency f1 and the second frequency f2 may be referred to as a fingerprint spatial frequency band FSB.

If the object touching the fingerprint sensing area of the touch screen panel (200 of FIG. 10) or the display panel (100 of FIG. 1) is a human fingerprint, then the sensing signal, i.e., the fingerprint space frequency band FSB) may be relatively larger than the signal strength of other frequency bands.

Therefore, the fingerprint sensor 300 determines whether the object is a fingerprint of a person based on the signal intensity of the fingerprint space frequency band (FSB) among the normal spatial frequency components of the sensing signal obtained from one direction of the partial region on the fingerprint sensing region 101 Can be determined.

For example, as shown in FIG. 17B, even if the power of the sensing signal is distributed over a wide frequency band, the fingerprint sensor 300 can measure the signal intensity of the fingerprint space frequency band (FSB). For example, the signal processor (323 in FIG. 8) can measure (or extract) the signal intensity of the fingerprint space frequency band (FSB) of the sensing signal through a Fourier transform, a bandpass filter or the like. The fingerprint sensor 300 can calculate the power of the fingerprint space frequency band (FSB) based on the signal strength of the measured fingerprint space frequency band (FSB). When the power of the fingerprint space frequency band FSB of the sensing signal occupies a certain ratio or more of the power of the entire frequency band (hereinafter, referred to as total frequency power), the fingerprint sensor 300 scans the fingerprint of the person It can be judged that it has been generated. In other words, the fingerprint sensor 300 can judge an object contacted on the fingerprint sensing area 101 of the touch screen panel (200 in Fig. 10) or the display panel (100 in Fig.

18 is a flowchart illustrating a method for determining whether or not an object on a fingerprint sensing area according to an embodiment of the present disclosure is a fingerprint.

The fingerprint sensor 300 can acquire a sensing signal from one direction of the partial area of the fingerprint sensing area 101 that the object touches (S10). The fingerprint sensor 300 may receive an analog sensing signal from pixels corresponding to the partial area of the pixel array 310 (FIG. 8), and may convert the analog sensing signal into a digital sensing signal. Thereby, the sensing signal can be obtained.

The fingerprint sensor 300 may analyze the frequency component of the sensing signal (S20). For example, the frequency analysis filter 323_1 included in the signal processor 323 of FIG. 8 can analyze the normal spatial frequency component of the sensing signal. For example, the frequency analysis filter 323_1 may be a digital IIR filter, and the digital IIR filter may extract signal intensity or power of the fingerprint space frequency band from the sensing signal.

The fingerprint sensor 300 may determine whether the object is a fingerprint based on a frequency component corresponding to a fingerprint space frequency band among the regular spatial frequency components of the sensing signal (S30). For example, the fingerprint sensor 300 may compare the signal strength of the entire frequency band of the sensing signal with the signal intensity of the fingerprint space frequency band, for example, the frequency range of about k * 1.5 KHz to k * 4 KHz frequency region to determine whether the object is a fingerprint have. In an embodiment, the fingerprint sensor 300 may determine that the object is a human fingerprint when the power of the fingerprint space frequency band of the sensing signal occupies a certain ratio or more of the total frequency power.

In an embodiment, the fingerprint sensor 300 acquires a plurality of sensing signals from a plurality of directions of the partial region and, based on the normal spatial frequency components of the plurality of sensing signals, Can be determined.

The direction of the fingerprint touching the fingerprint sensing area 101 may vary. Accordingly, the fingerprint sensor 300 can accurately determine whether the object is a fingerprint by acquiring sensing signals in various directions and analyzing the obtained sensing signals. In an embodiment, the fingerprint sensor 300 may obtain sensing signals in more than three directions.

19A and 19B are diagrams illustrating a method of acquiring a plurality of sensing signals on a fingerprint sensing area.

The fingerprint sensor 300 may acquire sensing signals in three directions R1, R2, and R3 based on the center point P1 as shown in FIG. 19A, or may acquire sensing signals in the center point P1 as shown in FIG. R2, R3, and R4 based on the received signals. However, this is only exemplary embodiments, and the fingerprint sensor 300 can acquire sensing signals in at least two directions. In the embodiment, the three directions R1, R2, R3 in FIG. 19A or the four directions R1, R2, R3, and R4 in FIG. 19B may have a certain angle with respect to the center point P1.

The fingerprint sensor 300 may determine whether the object is a fingerprint of a person based on the sensing signals obtained in at least two directions.

20 is a diagram showing a method of acquiring a plurality of sensing signals in a plurality of directions on a fingerprint sensing area.

Referring to FIG. 20, the sensing circuit 321a of the fingerprint sensor may acquire a plurality of sensing signals from a plurality of regions of the pixel array 310a.

The sensing circuit 321a may include a plurality of analog-to-digital conversion circuits (ADCs) coupled to respective channels of the pixel array 310a. As shown, it may be sensed line by line from the top to the bottom of the pixel array 310a. When sensing in units of lines, the analog-to-digital conversion circuit (ADC) corresponding to the channel connected to the sensing pixels included in the sensed three-directional areas PA1, PA2 and PA3 operates and is included in the non- The analog-to-digital conversion circuits (ADCs) corresponding to the channels connected to the sensing pixels may not operate.

For example, when the A1 section and the A3 section are sensed, one analog-digital conversion circuit (ADC) corresponding to the first area PA1 operates, and when the A2 section is sensed, Three analog-to-digital conversion circuits (ADCs) corresponding to the areas PA1, PA2, and PA3 may operate. An analog-to-digital conversion circuit (ADC) receiving the analog sensing signals may convert the analog sensing signals into digital sensing signals. The converted digital signals are subjected to signal processing, whereby sensing signals in three directions, i.e. digital sensing signals, can be obtained.

21 is a flowchart illustrating a method for determining whether an object on the fingerprint sensing area is a fingerprint, according to an embodiment of the present disclosure. 22 is a graph showing signal intensities of a plurality of sensing signals in the frequency domain. 21 shows a method of determining whether an object is a fingerprint of a person based on a plurality of sensing signals, and the determination method of FIG. 21 may be exemplarily performed in the controller 322 of the fingerprint sensor 300a of FIG. 8 have.

, 제2 센싱 신호(SS2)의 정규 공간 주파수

및 제3 센싱 신호(SS3)의 정규 공간 주파수

은 상이한 분포를 나타낼 수 있다. 따라서, 제1 센싱 신호(SS1), 제2 센싱 신호(SS2) 및 제3 센싱 신호(SS3) 각각으로부터 추출된 공간 주파수 대역(FSB)의 신호 세기들은 상이할 수 있다. Referring to FIG. 21, the fingerprint sensor may extract the signal strength of the fingerprint space frequency band (FSB) for each of the plurality of sensing signals (S31). For example, referring to FIG. 22, the normal spatial frequency of the first sensing signal SS1

The second spatial frequency of the second sensing signal SS2,

And the third spatial frequency SS3 of the third sensing signal SS3

Can exhibit different distributions. Therefore, the signal intensities of the spatial frequency band FSB extracted from the first sensing signal SS1, the second sensing signal SS2, and the third sensing signal SS3, respectively, may be different.

The fingerprint sensor can assign a weight to each of the plurality of sensing signals according to the signal strength of the spatial frequency band (FSB). Different weights may be assigned to each of the plurality of sensing signals.

The fingerprint sensor may sum the weights assigned to each of the plurality of sensing signals (S33). The fingerprint sensor can determine whether the sum value is equal to or greater than the threshold value (S34). For example, the threshold value may be set to the minimum value of the summation value calculated in accordance with steps S31, S32, and S33 based on the sensing signals obtained when the fingerprint of a person is scanned in a plurality of directions, e.g., at least three directions.

The fingerprint sensor can determine that the object is a human fingerprint if the sum value is equal to or greater than the threshold value (S35). If the sum value is less than the threshold value, the fingerprint sensor can determine that the object is not the fingerprint of the person (S36).

23 is a flowchart illustrating a method for determining whether an object on a fingerprint sensing area is a human fingerprint, according to an embodiment of the present disclosure; 23 shows a method of determining whether an object is a human fingerprint based on a plurality of sensing signals, and the determination method of FIG. 23 may be illustratively performed in the controller 322 of the fingerprint sensor 300a of FIG.

Referring to FIG. 23, the fingerprint sensor can calculate the power ratio of the spatial frequency band to each of the plurality of sensing signals (S41). For example, the ratio of the power of the spatial frequency band to the power of the entire frequency band can be calculated for each of the plurality of sensing signals. 22, the fingerprint sensor can calculate the power ratio of the spatial frequency band FSB to each of the first sensing signal SS1, the second sensing signal SS2, and the third sensing signal SS3 . The power ratio of the second sensing signal SS2 in the spatial frequency band may be the highest.

The fingerprint sensor can determine whether the power ratio of at least one sensing signal is equal to or greater than a threshold ratio (S34). For example, the fingerprint sensor determines whether at least one of ratios of power of the spatial frequency band calculated for each of the first sensing signal SS1, the second sensing signal SS3, and the third sensing signal SS3 is equal to or greater than a threshold ratio It can be judged.

If the power ratio of at least one sensing signal is equal to or higher than the threshold ratio, the fingerprint sensor can determine that the object is a fingerprint of a person (S35). If the power ratio of all sensing signals is less than the threshold ratio, the fingerprint sensor can determine that the object is not a fingerprint of a person (S35).

As described above, a method of determining whether an object on a fingerprint sensing area is a human fingerprint has been described with reference to Figs. 18 and 21 to 23. Fig. However, this is only an exemplary embodiment, and the judgment method can be variously modified.

24 is a diagram illustrating a smartphone according to an embodiment of the present disclosure;

Referring to FIG. 24, the smartphone 4000 may include a touch screen panel 4100, a touch screen housing 4500, and a fingerprint sensor 4300 disposed under the touch screen panel 4100. The smartphone 4000 may also include a touch screen drive circuit, e.g., a display drive circuit and a touch controller, for driving an AP and a touch screen panel 4100 to control the overall operation of the smartphone 4000 therein.

The housing 4500 may form the appearance of the smartphone 4000 and may protect components within the smartphone 4000, such as integrated circuits, batteries, antennas, etc., from external shocks or scratches.

The touch screen panel 4100 can operate as an input / output device of the smartphone 4000 by performing display, touch sensing, and fingerprint sensing. In an embodiment, the touch screen panel 4100 may sense the force of the touch input. The touch screen panel 4100 may include a display layer and a touch sensing layer.

The display device (1000 in Fig. 1), the touch screen device (2000 in Fig. 10), and the mobile device (3000 in Fig. 13) described with reference to Figs. 1, 10 and 13 can be applied as the smartphone 4000.

The fingerprint sensor 4300 is disposed under the touch screen panel 4100 and fingerprint sensing can be performed based on the light emitted from the touch screen panel 4100. [ The area of the touch screen panel 4100 may not be reduced because a separate space for the fingerprint sensor is not required on the front surface of the smartphone 4000 because the fingerprint sensing area overlaps with the display area.

Further, in the smartphone according to the embodiment of the present disclosure, when the fingerprint sensor 4300 controls the display driving circuit in the fingerprint sensing operation, the time for the pixels provided in the display layer to emit with high brightness for fingerprint sensing can be reduced have. This can prevent display performance from deteriorating.

Also, when an object touches the fingerprint sensing area, the fingerprint sensor 4300 determines whether the object is a fingerprint based on a sensing signal or a partial image generated by scanning a partial area of the fingerprint sensing area. It is possible to prevent the unnecessary fingerprint matching operation from being performed in the AP, and the consumption current of the smartphone can be reduced.

Although the present disclosure has been described with reference to the embodiments shown in the drawings, it is to be understood that various modifications and equivalent embodiments may be made by those skilled in the art without departing from the scope and spirit of the present invention. Accordingly, the true scope of protection of the present disclosure should be determined by the technical idea of the appended claims.

1000: Display device 2000: Touch screen device
3000: Mobile device 4000: Smartphone
100: display panel 200, 200a: display driving circuit
300, 300a: fingerprint sensor 400: touch controller
500: Application processor

Claims (20)

A method of operating a fingerprint sensor for sensing a fingerprint image based on reflected light reflected from the fingerprint,
Transmitting a first signal requesting light on to a display driving circuit for driving a display panel stacked on the fingerprint sensor;
Scanning an object on the display panel based on light emitted from the display panel; And
And transmitting a second signal requesting light-off to the display driving circuit. The method according to claim 1,
Prior to the step of transmitting the first signal,
Receiving a fingerprint sensing request signal from an external device; And
Further comprising performing an internal circuit setting operation for fingerprint sensing in response to the fingerprint sensing request signal. The apparatus according to claim 2,
Wherein the fingerprint sensor is one of a touch controller, an application processor, and a sensor hub. 3. The method of claim 2, wherein the fingerprint sensing request signal
Wherein the touch panel is received when a touch input occurs due to contact or proximity of the object on the display panel. The method according to claim 1,
After the step of transmitting the second signal,
And processing the sensing signals generated according to the scan to generate a fingerprint image. 2. The method of claim 1,
A light emission request signal, and partial area information. 7. The method of claim 6,
Wherein the display unit displays a partial area for emitting light in the fingerprint sensing area on the display panel. 8. The method of claim 7,
Wherein each time a fingerprint sensing request signal is received from an external device, a partial area indicated by the partial area information is varied. 8. The method of claim 7, further comprising: processing the sensing signals generated according to the scan to generate a partial image; And
Further comprising determining whether the partial image is a human fingerprint image. 10. The method of claim 9,
Further comprising generating a fingerprint image for the object and providing the fingerprint image to an external processor if the partial image is determined to be a human fingerprint image. A display panel including a plurality of pixels;
A display driving circuit for driving the display panel so that an image is displayed on the display panel; And
And a fingerprint sensor disposed under the display panel and sensing a fingerprint based on light emitted from at least a part of the plurality of pixels of the display panel,
Wherein the fingerprint sensor controls light emission and extinction of the display panel during a fingerprint sensing operation. The fingerprint sensor according to claim 11,
And controls the light emission and the extinction of the display panel by transmitting at least one of a light emission request signal and an extinction request signal to the display driving circuit. 13. The display driving circuit according to claim 12,
And the display panel is driven in response to the light emission request signal so that the light is emitted from at least a part of the first area of the display panel. 14. The display driving circuit according to claim 13,
And changes at least a part of the region where the light is emitted each time the light emission request signal is received from the fingerprint sensor. 13. The fingerprint sensor according to claim 12,
A pixel array including a plurality of sensing pixels; And
And a sensing circuit that drives the pixel array and scans the fingerprint by receiving sensing signals provided from the pixel array,
Wherein the controller transmits the light emission request signal to the display driving circuit after the sensing circuit completes the fingerprint scan preparation in response to the fingerprint sensing request signal received from the external device. A method of operating an electronic device including a touch screen on which a fingerprint sensor is stacked,
The fingerprint sensor transmitting a light emission request signal to a display driving circuit for driving a display panel of the touch screen;
Emitting the display pixels included in at least a part of the fingerprint sensing area on the touch screen based on the light emission request signal; And
And the fingerprint sensor scanning an object on the touch screen based on light emitted from the touch screen. The fingerprint sensor according to claim 16,
Wherein the display device is switched from a low power mode to an operation mode in response to a touch input on the touch screen and transmits the light emission request signal to the display drive circuit in the operation mode. The fingerprint sensor according to claim 16,
Wherein the display device is switched from a low power mode to an operation mode in response to a touch force on the touch screen, and in the operation mode, the light emission request signal is transmitted to the display drive circuit. 17. The method of claim 16, further comprising determining whether the object is a fingerprint based on sensing signals according to the object scan. 20. The method of claim 19, wherein if the object is determined to be a fingerprint, the fingerprint sensor transmits a wake-up signal to the application process;
The fingerprint sensor obtaining an entire fingerprint image corresponding to the object; And
Wherein the fingerprint sensor further comprises transmitting the entire fingerprint image to an application processor.

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