KR20150131944A - Display apparatus having image scanning function - Google Patents

Abstract

Disclosed is a fingerprint sensing display capable of sensing a fingerprint on a screen thereof. The display apparatus capable of scanning an image according to the present invention includes: a light amplification cover unit which has one side forming the surface of the display and includes a transparent light amplification layer, which amplifies a light pattern generated by user′s fingerprint imprinted on the surface of the display, and a cover window for reinforcing the strength; a thin film transistor (TFT) array which drives multiple pixels constituting an image; and a light sensor array which is arranged between the light amplification cover unit and the TFT array and senses the light pattern amplified by the light amplification cover unit.

Description

[0001] DISPLAY APPARATUS HAVING IMAGE SCANNING FUNCTION [0002]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a display device capable of scanning a surface image of a subject on a display screen and more particularly to a display device having a display function and a sensor array including a sensor array for receiving reflected light for a fingerprint pattern, ≪ / RTI >

Security issues related to information and communications have become a hot issue in recent years, and security related technology has become a hot topic in personal mobile devices such as smart phones and tablet PCs. In particular, as electronic commerce through users' mobile devices is increasing, security of personal information is demanded. According to this demand, an individual is identified and authenticated using biometric information such as fingerprint, iris, face, voice, Technologies are being utilized. The most commonly used technology among various biometric information authentication technologies is fingerprint authentication technology. In recent years, smartphone and tablet PCs have been introduced with fingerprint recognition and authentication technology. However, in order to attach a sensor device for fingerprint recognition to a portable device, a device for fingerprint recognition must be mounted in addition to a display device, thereby increasing the size and thickness of the portable device.

On the other hand, mobile devices such as smartphones and tablet PCs are very often exposed to the risk of shock, friction, and scratches in their environment of use. Therefore, in order to protect the touch interface and the display device from such a use environment, a tempered glass cover is employed as a portable device. The tempered glass cover is an important factor for the above reason, but it may be an obstacle to enhance the sensitivity of the sensor from the viewpoint of fingerprint recognition, and thus it is required to overcome the obstacle.

SUMMARY OF THE INVENTION The present invention has been made in order to solve the above-mentioned problems, and it is an object of the present invention to provide an image display apparatus and a display apparatus, which are capable of ensuring a sufficient level of sensor sensitivity necessary for fingerprint recognition without deteriorating display performance, And it is an object of the present invention to provide a scanable display device.

According to an aspect of the present invention, there is provided an image-scanable display device including a transparent optical amplification layer for amplifying a light pattern due to a fingerprint of a user contacting a display surface, An optical amplification cover portion having a cover window for emitting light; A thin film transistor (TFT) array for driving a plurality of pixels constituting an image; And a photosensor array disposed between the optical amplification cover unit and the thin film transistor array and sensing the amplified light pattern in the optical amplification cover unit.

The transparent optical amplification layer may include a plurality of quantum dots that absorb light in a first wavelength range and emit light in a second wavelength range different from the first wavelength range. At this time, the first wavelength region may belong to a visible light region, and the second wavelength region may belong to an infrared region.

On the other hand, the transparent optical amplification layer includes a polarization conversion layer, and the polarization conversion layer includes a plurality of quantum dots that absorb first polarized light and emit a second polarized light whose polarization axis is substantially perpendicular to the first polarized light It is possible.

Wherein the optical amplification cover portion includes: a cover window having one surface thereof as a display surface; And a transparent optical amplification layer formed on the opposite side of the display surface of the cover window.

On the other hand, the optical amplification cover section includes a cover window; A transparent optical amplification layer formed on an upper surface of the cover window; And a protective layer formed on an upper surface of the transparent optical amplification layer, the surface of which forms the display surface, and the optical sensor array may be formed on a lower surface of the cover window.

The thin film transistor (TFT) array and the optical sensor array may be arranged so as to overlap each other in plan view to constitute a part of one sensor integrated display panel.

The sensor integrated display panel is a liquid crystal display panel. The sensor integrated display panel includes a lower substrate part having a thin film transistor (TFT) array for driving the plurality of pixels formed in a lower substrate; And an upper substrate portion formed on the inner side of the upper substrate to correspond to the non-transparent portion of the thin film transistor (TFT) array to shield visible light and an optical sensor array arranged to overlap the black matrix.

In this case, the black matrix may be formed of an infrared filter resin that blocks visible light but transmits infrared light, and the optical sensor array may include a plurality of infrared sensors. The plurality of infrared sensors may be disposed at positions where the thin film transistor (TFT) array overlaps the thin film transistor unit driving the pixel electrodes in a planar manner.

In the sensor integrated display panel, the optical sensor array may include a metal wiring and an optical sensor arranged inside the black matrix. In this case, the upper substrate portion may further include an optical waveguide formed on a portion of the black matrix corresponding to the optical sensor, or may include at least one microlens formed on a portion corresponding to the optical sensor.

In the sensor integrated display panel, the photosensor array may include a wiring and an optical sensor disposed between the upper substrate and the black matrix. In this case, the wiring may be a transparent electrode wiring or a metal wiring having an antireflection layer formed on a surface in contact with the upper substrate.

The optical amplification cover unit may be configured such that infrared light incident on the transparent optical amplification layer to satisfy the internal total reflection condition is scattered by the fingerprint touched on the display surface and emitted to the optical sensor array side.

According to an aspect of the present invention, there is provided an image-scanable display device including: a lower substrate portion having a thin film transistor (TFT) array formed therein for driving the plurality of pixels; An upper substrate portion formed on the inner side of the upper substrate to correspond to the non-transparent portion of the thin film transistor (TFT) array and having a black matrix for shielding visible light and an optical sensor array arranged to overlap the black matrix; And a liquid crystal layer disposed between the lower substrate and the upper substrate.

Here, the black matrix may be formed of an infrared filter resin that shields visible light but transmits infrared light, and the optical sensor array may include a plurality of infrared sensors. The plurality of infrared sensors may be disposed at positions where the thin film transistor (TFT) array overlaps the thin film transistor unit driving the pixel electrodes in a planar manner.

The photosensor array may include a metal wiring and an optical sensor disposed inside the black matrix. In this case, the upper substrate portion may further include an optical waveguide formed on a portion of the black matrix corresponding to the optical sensor, or may include at least one microlens formed on a portion corresponding to the optical sensor.

Meanwhile, the photosensor array may include a wiring and an optical sensor disposed between the upper substrate and the black matrix. In this case, the wiring may be a transparent electrode wiring or a metal wiring having an antireflection layer formed on a surface in contact with the upper substrate.

According to another aspect of the present invention, there is provided an image scanning device capable of scanning an image, comprising: an optical amplification cover part for amplifying a light pattern of a fingerprint of a user contacting the display surface, A display panel having a thin film transistor (TFT) array for driving a plurality of pixels constituting an image; And an optical sensor array disposed between the optical amplification cover unit and the thin film transistor (TFT) array for sensing a light pattern amplified by the optical amplification cover unit, wherein the optical sensor array comprises: And is arranged to overlap with the black matrix of the display panel in a planar manner.

According to the present invention, there is provided a display device comprising: a cover window that provides durability suitable for a use environment of a portable device; and a transparent optical amplification layer that compensates for the deterioration of the sensitivity of the optical sensor, There is an effect of providing an image scanable display device.

According to the present invention, the optical sensor array for fingerprint sensing is disposed close to the display surface, but is disposed under the light-shielding pattern such as a black matrix, so that the display sensor can display a sufficient level There is an effect of providing an image scanable display device configured to secure sensor sensitivity.

1 shows an example of the use of a portable device equipped with a display device capable of scanning an image according to the present invention.
FIG. 2 schematically shows the configuration of an image scanable display device according to an embodiment of the present invention.
FIG. 3 schematically shows the configuration of an image scanable display device according to an embodiment of the present invention.
4 schematically shows the configuration of an image scanable display device according to an embodiment of the present invention.
FIG. 5 shows an embodiment of the transparent optical amplification layer in the embodiment of FIG. 2 to FIG.
6 shows an optical amplification cover unit in an image-scanable display device according to an embodiment of the present invention.
7 shows an optical amplification cover unit in an image scanable display device according to an embodiment of the present invention.
8 shows an optical amplification cover unit in an image-scanable display device according to an embodiment of the present invention.
9 schematically shows the configuration of a sensor integrated display panel in an image scanable display device according to an embodiment of the present invention.
10 is a partial enlarged view of the sensor integrated display panel according to the embodiment of FIG. 9 on the display surface side.
11 shows a cross section taken along line XI-XI in Fig.
12 conceptually illustrates the principle of fingerprint sensing of an image scanable display device according to an embodiment of the present invention.
13 shows one embodiment of the upper substrate portion in a sensor integrated display panel according to an embodiment of the present invention.
14 shows one embodiment of the upper substrate portion in a sensor integrated display panel according to an embodiment of the present invention.
15 shows one embodiment of an upper substrate portion in a sensor integrated display panel according to an embodiment of the present invention.
16 is a view illustrating a combined structure of the optical amplification cover and the upper substrate of the sensor integrated display panel in the image-scanable display device according to an embodiment of the present invention.
17 shows an alignment state between a black matrix of a liquid crystal display panel and a photosensor array coupled to an optical amplification cover portion in an image scanable display device according to an embodiment of the present invention.
FIG. 18 shows a method of utilizing the optical sensor array as a touch sensor in an image-scanning capable display device according to an embodiment of the present invention.
19 is a block diagram of a display device according to embodiments of the present invention.
20 shows a circuit diagram of a photosensor of a comparative example.
21 is a cross-sectional view of a pixel and an optical sensor according to embodiments of the present invention.
22 is an enlarged cross-sectional view of one embodiment of the subpixel shown in FIG.
23 is an enlarged cross-sectional view of another embodiment of the subpixel shown in FIG.
FIG. 24 is an enlarged cross-sectional view of another embodiment of the subpixel shown in FIG. 21. FIG.
25 is a conceptual diagram showing a method of scanning a subject by the display device of the present invention.
26 is a conceptual diagram showing a method of scanning a subject by the display device of the present invention.
27 is a signal diagram showing the operation of the gate driver and the source driver when the display device of the present invention is displayed.
28 is a signal diagram showing the operation of the gate driver and the source driver when the display device of the present invention scans an object;
29 to 31 are conceptual diagrams showing various methods of scanning a subject by the display device of the present invention.
32 is a view showing a configuration of a sensor array layer implementing an image scanning function according to an embodiment of the present invention.
33 is a circuit diagram showing an embodiment of the charge sharing scheme of the optical sensor SN shown in Fig.
34 is a circuit diagram showing another embodiment of the charge sharing scheme for the optical sensor SN of Fig.
FIG. 35 is a circuit diagram showing the configuration of a charge-shaking type optical sensor applicable to a display device according to an embodiment of the present invention.
36 is a timing chart for explaining the operation of the charge-sharing type optical sensor according to an embodiment of the present invention.
37 is a circuit diagram showing another embodiment of the source follower scheme for the optical sensor of Fig. 32. Fig.
38 is a circuit diagram showing a configuration of a source follower type optical sensor applicable to a display device according to an embodiment of the present invention.
FIG. 39 is a timing chart for explaining an operation of a source follower type optical sensor according to an embodiment of the present invention.
40 is a plan view showing a layout of a circuit structure of a source follower type optical sensor according to an embodiment of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described with reference to the accompanying drawings. The present invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. In order to clearly explain the present invention, parts not related to the description are omitted, and the same reference numerals are given to the same components throughout the specification.

For the sake of convenience, the expression including the upper and lower concepts such as the upper, lower, upper, and lower surfaces is based on the directions shown in the drawings unless otherwise specified. In the attached drawings, Is arranged on the upper side and the opposite side is arranged on the lower side.

Throughout the specification, when a part is referred to as being "connected" to another part, it includes not only "directly connected" but also "indirectly connected" . Also, when an element is referred to as "comprising ", it means that it can include other elements, not excluding other elements unless specifically stated otherwise. Further, "optical sensor" means a sensor element that provides an electrical signal according to the intensity of the applied light. From the viewpoint of device configuration, various types of devices such as a phototransistor (photo TFT) and a photodiode are included, and from the viewpoint of a wavelength band to be sensed, an infrared sensor and the like as well as a visible light sensor can be included.

1 shows an example of the use of a portable device equipped with a display device capable of scanning an image according to the present invention.

For example, a portable device (MD) may be a digital device having a display function such as a smart phone, a tablet PC, an electronic book or a navigation device, a wired / wireless communication function, an information processing calculation function, and a media play. Such portable devices include various types of flat panel displays such as an electronic paper (E-Paper) display, a field emission display (FED), a quantum-dot display and the like as well as a liquid crystal display A display (FPD) device may be employed. Here, an example of a smartphone is mainly described, but the present invention is not limited thereto. The image scanable display device (FSD) according to the present invention can be implemented based on the above-described various types of flat panel displays, and can be employed in any device requiring a display function and a fingerprint sensing function.

The image scanable display device FSD is formed on one surface of the portable device MD and is preferably formed on the front surface of the portable device MD as shown in Fig. 1, and functions as a display device and an input such as a touch interface It may also serve as a device. An image scanable display device (FSD) detects a fingerprint pattern (FP) from a user's finger (F) that has contacted some area (SA) of its display surface. The position where the finger F is touched is detected first, the partial area SA is set according to the position, and the fingerprint pattern FP is detected in the area.

As will be described later, the image-scanable display device (FSD) according to the present invention senses a light pattern generated according to the form of ridges and valleys of the fingerprint when the finger is brought into contact with the display surface, (FP). Thus, the image scanable display device (FSD) comprises a photosensor array having a plurality of photosensors arranged to have a resolution sufficient to distinguish ridges and valleys of a fingerprint. In the image scanable display device (FSD), the photosensor array is mainly emitted from the display surface to sense the light reflected from the surface of the finger F, but may also detect the incident ambient light transmitted through the finger F. For example, the light sensed by the photosensor array may be non-visible light, such as infrared light. The visible light constituting the display image can be prevented from affecting the fingerprint sensing by detecting the non-visible light. However, the scope of the present invention is not limited thereto, and according to another example, the photosensor array may sense visible light.

FIG. 2 schematically shows the configuration of an image scanable display device according to an embodiment of the present invention.

Referring to the drawings, the image-scanning capable display device 11 according to the present embodiment includes a sensor integrated display panel (SID) having an optical sensor array integrated on a display panel and an optical amplification cover portion 101 disposed on the sensor integrated display panel do. The optical amplification cover part 101 has a transparent optical amplification layer 120 and a cover window 110 for strengthening the intensity, which amplify a light pattern due to a fingerprint of a user contacting the display surface, In this embodiment, the cover window 110 constitutes a display surface, and the transparent optical amplification layer 120 is disposed between the cover window 110 and the sensor integrated display panel (SID).

Here, the sensor integrated display panel (SID) includes a thin film transistor (TFT) array for driving a plurality of pixels constituting an image and a light emitting diode (LED) array disposed closer to the optical amplification cover unit 120 than the thin film transistor array, And a photosensor array that senses the amplified light pattern in the light source 120. In a configuration for a function as a display panel, the sensor integrated display panel (SID) may be an active matrix drive type liquid crystal display panel or an active matrix drive type organic light emitting diode display panel. In addition to the two display panels, any display panel having a thin film transistor array driving a plurality of pixels arranged in a matrix form may be used.

When the sensor integrated display panel (SID) is a liquid crystal display panel, a backlight unit 300 may be provided under the sensor integrated display panel (SID). The backlight unit 300 generally includes a light source 310 that emits visible light, and may further include a light source 320 that emits infrared light as needed.

The cover window 110 may be made of a tempered glass or a transparent material having a corresponding strength and hardness, such as is typically applied to a top surface of a touch screen of a smart phone.

The transparent optical amplification layer 120 performs a function of increasing the light amount of light finally received by the optical sensor array for fingerprint sensing through wavelength conversion or polarization conversion or additionally supplying the light amount through total internal reflection, The concrete structure and operation will be described later with reference to embodiments in which various types of transparent optical amplification layers are applied.

FIG. 3 schematically shows the configuration of an image scanable display device according to an embodiment of the present invention.

The image-scanable display device 12 according to the present embodiment is the same as the embodiment of FIG. 2 except for the configuration of the optical amplification cover part 102. FIG. The optical amplification cover part 102 includes a cover window 110, a transparent optical amplification layer 120 formed on the top surface of the cover window, and a transparent optical amplification layer 120 formed on the transparent optical amplification layer 120, And a protective layer 130 that forms a surface. The passivation layer 130 may be formed of a thin film or a polymer film made of glass, silicon oxide, silicon nitride, or other transparent oxide or polymer as a coating layer of a transparent material having a hardness higher than that of the transparent optical amplification layer 120 .

4 schematically shows the configuration of an image scanable display device according to an embodiment of the present invention.

According to the present embodiment, the sensor array layer 150 having a photosensor array is integrally formed on the lower surface of the cover window 110 in the optical amplification cover section 102 having the configuration described in the embodiment of FIG. And a fingerprint sensor module 21 having an optical amplification cover part 102. The fingerprint sensor module 21 is disposed above the display panel 209. [ The display panel 209 may include various types of display devices such as a liquid crystal display (LCD), an organic light emitting diode (OLED) display, an electronic paper (E-Paper) display, a field emission display (FED), a quantum- Type flat panel display (FPD) panel. In the case of a liquid crystal display panel, a backlight unit 300 including a visible light source 310 may further be provided. The backlight unit 300 may include an infrared light source 320 if necessary.

FIG. 5 shows an embodiment of the transparent optical amplification layer in the embodiment of FIG. 2 to FIG.

The transparent optical amplification layer 120 may include a transparent medium 121 and a plurality of quantum dots 122 distributed in the transparent medium 121. In the embodiments described above, The plurality of quantum dots 122 may be formed of various materials and sizes as a kind of nanostructure having a nucleus-shell structure and a diameter of several nanometers. Depending on the type and size of the material, And can emit light in a different wavelength region.

Therefore, the transparent optical amplification layer 120 including the plurality of quantum dots 122 can absorb the light w1 in the first wavelength range, convert it into the light w2 in the second wavelength range, have. For example, the light w1 in the first wavelength region may be light in a visible light wavelength range, and the light w2 in the second wavelength region may be light in an invisible light wavelength band. More specifically, The light w1 in the region may be blue light and the light w2 in the second wavelength region may be infrared light. As another example, both the first wavelength region and the second wavelength region may belong to the infrared region. A wavelength having a high energy is converted into a wavelength having a low energy, and a wavelength having a low energy can be converted into a wavelength having a high energy by using an additional structure (a quantum dot structure, a catalyst, etc.) (upconversion). Here, the light of the second wavelength region is preferably a light of a wavelength range mainly sensed by a plurality of optical sensors included in the optical sensor array.

The transparent optical amplification layer 120 is preferably disposed on a path along which the light emitted from the display panel (hereinafter, referred to as display light) travels toward the user, so that it does not affect the display light. However, in the case where the backlight unit or the organic light emitting diode display panel on the rear surface of the liquid crystal display panel does not emit the infrared light separately from the display light, a part of the blue light is absorbed so as to minimize the color reproducibility of the display panel, To be used for fingerprint sensing.

6 shows an optical amplification cover unit in an image-scanable display device according to an embodiment of the present invention.

The optical amplification cover unit according to the present embodiment may include a transparent optical amplification layer 160 having a polarization conversion function together with a cover window 110 that contacts the finger F of the user. The transparent optical amplification layer 160 may have a polarization conversion layer functioning to convert the first polarized light P1 into a second polarized light P2 whose polarization axis is substantially perpendicular to the first polarized light P1. The transparent optical amplification layer 160 includes a polarization conversion layer in which a plurality of quantum dots having a polarization conversion function are distributed in a transparent medium. The transparent optical amplification layer 160 may be formed of only a single polarization conversion layer And may be formed through bonding with other layers.

For example, the first polarized light P1 transmitted through the polarizer 251 disposed on the upper surface of the upper substrate 250 of the liquid crystal display panel is absorbed by the transparent optical amplification layer 160 having the polarized light conversion function, And emits a second polarized light P2 having a polarization axis perpendicular to the second polarized light P2. The transparent optical amplification layer 160 emits the second polarized light P2 that has been converted not only to the cover window 110 side but also to the lower side thereof and the second polarized light P2 emitted downward is polarized by the polarizer 251 So that it does not affect the photosensor array disposed under the upper substrate 250. The second polarized light P2 emitted toward the cover window 110 is reflected by the finger F touching the surface of the second polarized light P2 and is again mixed with the first polarized light P1 and the second polarized light P2 The first polarized light P1 is transmitted through the polarizing plate P1 to the optical sensor array disposed under the upper substrate 250. [ With this principle, the ratio of noise to the fingerprint pattern signal detected in the optical sensor array can be reduced.

7 shows an optical amplification cover unit in an image scanable display device according to an embodiment of the present invention.

The transparent optical amplification layer 163 in the optical amplification cover unit according to the present embodiment includes the first transparent optical amplification layer 161 which is the polarization conversion layer described with reference to the embodiment of FIG. 6, the cover window 110, And a second transparent optical amplification layer 162 disposed between the transparent optical amplification layers 161. The second transparent optical amplification layer 162 may not affect the polarization axis like the transparent optical amplification layer of the wavelength conversion function described in the embodiment of FIG. In this case, the effect of the above-described wavelength conversion effect according to the embodiment of FIG. 5 and the polarization conversion effect according to the embodiment of FIG. 6 described above can be obtained by the action of the transparent optical amplification layer 163.

8 shows an optical amplification cover unit in an image-scanable display device according to an embodiment of the present invention.

According to the present embodiment, the optical amplification cover part includes a transparent optical amplification layer 112 functioning as a light guide plate, and infrared light incident on the transparent optical amplification layer 112 to satisfy the internal total reflection condition is reflected on the display surface Is scattered by the fingerprint of the contacted finger (F) and is emitted to the photosensor array side disposed on the opposite side of the display surface. For this purpose, an infrared light source 321 may be disposed on at least one side of the transparent optical amplification layer 112. Meanwhile, the transparent optical amplifying layer 112 functioning as a light guide plate may be the cover window itself or a separate layer combined with the cover window.

9 schematically shows the configuration of a sensor integrated display panel in an image scanable display device according to an embodiment of the present invention. 10 is a partial enlarged view of the sensor integrated display panel according to the embodiment of FIG. 9 on the display surface side.

In this embodiment, the sensor integrated display panel (SID) may be, for example, a liquid crystal display panel in which a photosensor array is integrated. The sensor integrated display panel (SID) has an upper substrate 25 and a lower substrate 210 as shown, and has a liquid crystal layer 230 encapsulated therebetween. A pixel TFT array layer 220 having a thin film transistor array for driving a plurality of pixels is formed on an inner surface of the lower substrate 210.

A color filter array corresponding to a plurality of pixels is formed on the inner surface of the upper substrate 250. The color filter array selectively reflects light of a specific color such as red (R), green (G), and blue (B) And a black matrix 242 for shielding the plurality of light-transmitting portions between the light-transmitting portions in a matrix form. The black matrix 242 is formed to correspond to the non-transparent portion of the TFT array on the lower substrate 210. Metal lines such as data lines and gate lines and pixel driving TFTs arranged at the intersections of the metal lines and driving the corresponding pixel electrodes in accordance with electrical signals are included in the non-transparent portion of the thin film transistor (TFT) array.

According to the present embodiment, the photosensor array is arranged to be superimposed on the black matrix 242 to form an optical sensor array integrated color filter layer 240, which is an example of an overlapped shape, 242. < / RTI > The photosensor array includes a plurality of photosensors 243 corresponding to a plurality of sub-pixel areas SP, and a sensor drive circuit configured in a matrix form to drive them and read out the sensed signals therefrom . Here, the plurality of photosensors 243 may have a thin film transistor structure, or may have a diode structure or an organic thin film sensor structure. Although not shown in the figure, the sensor driving circuit may further include a metal wiring and a thin film transistor as a switching element in addition to the plurality of optical sensors 243.

11 shows a cross section taken along line XI-XI in Fig.

A lower substrate 210 and a pixel TFT array layer 220 formed on the lower substrate 210 are disposed below the liquid crystal layer 230. The pixel TFT array layer 220 includes a metal wiring 222 and an insulating film 225, a pixel electrode 221, and a pixel driving TFT 223 which are disposed to intersect with each other as data lines and gate lines. Actually, the gate line and the data line are formed in different layers with an insulating film interposed therebetween, and the pixel driving TFT 223 also has a structure in which a metal electrode, an insulating film, and a semiconductor channel are stacked.

An upper substrate unit 280 including an upper substrate 250 is disposed above the liquid crystal layer 230. The upper substrate portion 280 includes an optical sensor array integrated color filter layer 240 formed on the inner surface of the upper substrate 250. The light sensor array integrated color filter layer 240 is disposed in a superimposed manner under the black matrix 242 and the black matrix 242 as described above and includes the metal wiring 244 constituting the photosensor array, (243). The liquid crystal layer 230 may further include a planarization layer 245 covering and flattening the planarization layer 245 and the liquid crystal layer 230. Although not shown between the planarization layer 245 and the liquid crystal layer 230, A common electrode may be further provided.

In the above-described optical sensor array, the metal wiring 244 constituting the sensor driving circuit may include scan lines and lead-out lines which intersect with each other. They may be formed in different layers with an insulating film interposed therebetween. On the other hand, depending on the embodiment, they may be arranged in the same layer.

Here, the black matrix 242 may be formed of an infrared filter resin that blocks visible light and transmits infrared rays. As a result, although the optical sensor array is disposed on the upper substrate portion 280, the metal wiring 244 and the like can be prevented from being visually recognized on the display surface side. In addition, the light sensor 243 can receive light incident from the display surface side, that is, light reflected by the fingerprint, without receiving the liquid crystal layer 230. This makes it possible to improve the sensitivity of sensing the light pattern by the fingerprint.

12 conceptually illustrates the principle of fingerprint sensing of an image scanable display device according to an embodiment of the present invention.

The display light is emitted upward through the transparent portion 241 that selectively transmits red (R), green (G), and blue (B) light in the sensor integrated display panel. The transparent light amplifying layer 120 disposed on the upper substrate 250 converts part of the light w1 in the first wavelength range, that is, the blue light, into the infrared light w2 in the second wavelength range Release. The infrared light is reflected at a different reflectance depending on the ridge and valley of the finger (F) fingerprint touching the surface of the cover window 110, that is, the display surface, and the reflected light is transmitted through the black matrix 242 formed with the infrared filter resin again And is received by the optical sensor 243 of the optical sensor array. The image scanable display device according to the present embodiment provides a fingerprint pattern sensing function on this principle.

Although the transparent optical amplification layer 120 has a wavelength conversion function in the optical amplification cover unit 101, the configuration of the transparent optical amplification layer and the principle of optical amplification thereof are not limited thereto. 6 to 8 as described above.

13 shows one embodiment of the upper substrate portion in a sensor integrated display panel according to an embodiment of the present invention.

The upper substrate portion 281 includes an upper substrate 250 and a color filter array formed on the lower surface of the upper substrate 250 and having a transparent portion 241 and a black matrix 242, And a photosensor array disposed on the lower surface of the photodetector 242 and including a metal wiring 244 and an optical sensor 243. The black matrix 242 may be formed of an infrared filter resin that blocks visible light and transmits infrared light, and the optical sensor 243 may be an infrared light sensor having high sensitivity to infrared rays. According to the example shown in the figure, a portion of the black matrix 242 corresponding to the photosensor 243 has a light integration degree and a light transmittance, such as a slit, a via, The optical waveguide 246 may be formed in a shape that can be further increased.

The optical sensor 243 may be configured to detect visible light. The black matrix 242 may be formed of a material that blocks both visible light and infrared light. The optical waveguide 246 may be formed of, May be transparent to visible light.

A transparent planarization film 245 is disposed under the above-described photosensor array. The planarization layer 245 serves to smooth the surface of the upper substrate portion 281 in contact with the liquid crystal layer and the alignment layer may be disposed on the liquid crystal layer and the common electrode layer may be further provided. Same as.

14 shows one embodiment of the upper substrate portion in a sensor integrated display panel according to an embodiment of the present invention.

13 in that a microlens 247 is provided in place of the optical waveguide in the portion corresponding to the optical sensor 243 of the black matrix 242. The microlens 247 can collect and provide a larger amount of light to the optical sensor 243.

15 shows one embodiment of an upper substrate portion in a sensor integrated display panel according to an embodiment of the present invention.

As shown in the figure, a photosensor array including a wiring 248 and a photosensor 243 is disposed on the inner surface of the upper substrate 250 in the upper substrate portion 283, and the light transmitting portion 241 ) And a black matrix 242 may be arranged. A planarizing film 249 may be disposed between the optical sensor array and the color filter array.

In this case, the wiring 248 may be a wiring made of a transparent electrode material, and the optical sensor 243 may also be an element using an optically transparent oxide semiconductor. If the wiring 248 is a metal wiring, the wiring 248 may be formed of a metal such as aluminum nitride or aluminum nitride, Blocking layer 2442 may be formed. The antireflection layer 2442 may be formed of a metal oxide or the like having a black color, for example, and may be formed by the same process as the process of depositing the metal layer 441. On the other hand, in this case, since the optical sensor array is disposed above the color filter array, the material of the black matrix 242 may be applied to a general liquid crystal display panel as it is.

16 is a view illustrating a combined structure of the optical amplification cover and the upper substrate of the sensor integrated display panel in the image-scanable display device according to an embodiment of the present invention.

9 to 15, when the sensor integrated display panel is based on a liquid crystal display panel, the upper surface of the upper substrate 250, that is, the upper substrate 250, And a polarizing plate 251 is disposed between the optical amplification cover part 101 and the optical amplification cover part 101.

According to the present embodiment, a plurality of microlenses 252 and 253 may be provided on the upper and lower surfaces of the upper substrate 250. The plurality of microlenses 252 and 253 are disposed at positions corresponding to the optical sensors 243 disposed below the black matrix 242. The plurality of microlenses 252 and 253 concentrates the light to the optical sensor 243 through the opening 242A formed in the black matrix 242. The optical system including the plurality of lenses can effectively use a focal length You can fit it.

17 shows an alignment state between a black matrix of a liquid crystal display panel and a photosensor array coupled to an optical amplification cover portion in an image scanable display device according to an embodiment of the present invention.

As shown, the image-scanable display device according to the present embodiment has the layered structure as in the embodiment of Fig. 4 described above. That is, an optical sensor array including a wiring 244 and an optical sensor 243 is disposed under the optical amplification cover portion composed of the protective layer 130, the transparent optical amplification layer 120, and the cover window 110 from above And a fingerprint sensor module 21. The fingerprint sensor module 21 is arranged so as to be overlaid on the liquid crystal display panel 209. [

This figure shows a wiring 244 of the optical sensor array belonging to the fingerprint sensor module 21 and a black matrix 242 formed inside the upper substrate 250 of the optical sensor 243 and the liquid crystal display panel 209, The metal wiring 222 of the thin film transistor array formed inside the lower substrate 210 of the display panel 209 and the pixel driving TFT 223 are aligned so as to overlap with each other when viewed from above. A plurality of transparent portions 241 which are color filters for transmitting monochromatic light of red (R), green (G) and blue (B) colors are arranged on the plurality of pixel electrodes 221, The portions overlapping the plurality of transparent portions 241 are optically transparent. Thus, when the user looks down on the display surface, the optical sensor array of the fingerprint sensor module 21 does not affect the display resolution.

In this embodiment, the optical amplification cover section is provided with the transparent light-layer width layer 120 as described with reference to the embodiment of FIG. 5, but the present invention is not limited thereto. It may be replaced with an optical amplification cover portion.

FIG. 18 shows a method of utilizing the optical sensor array as a touch sensor in an image-scanning capable display device according to an embodiment of the present invention.

This figure is an enlarged view of a portion (A ') of the optical sensor array in a sensor integrated display device (SID). The wirings 244 arranged in a matrix form provide a plurality of sub-pixel areas divided by intersecting a plurality of horizontal wirings (scan lines) and vertical wirings (lead-out lines), and each sub- R), green (G), or blue (B) light, and an optical sensor 243 are disposed. Here, since one optical sensor 243 is disposed for each subpixel, the subpixel can be regarded as one sensing pixel. When the fingerprint is sensed using the image-scanable display device according to the present invention, the optical sensor array reads out an electrical signal for each of the subpixels, that is, for each sensing pixel to detect the fingerprint pattern with a high resolution .

On the other hand, the optical sensor array described above may also serve as a touch sensor. When used as a touch sensor, high resolution is not required, so that a plurality of sensing pixels can be grouped and driven. The power consumption and the time required for the touch sensing may be reduced by performing the scanning and the lead-out process in units of the plurality of sensing pixel groups as in the first sensing pixel group G1 and the second sensing pixel group G2 .

Hereinafter, a method of scanning an object located on a surface of a display, such as a fingerprint of a user, in a display device incorporating an optical sensor array having a plurality of optical sensors according to an aspect of the present invention will be described in detail with reference to an example do.

A display device according to an embodiment of the present invention includes a plurality of pixels arranged in a plurality of rows and columns and each of which is composed of at least two or more subpixels emitting light of different colors and a plurality of subpixels A cell array including optical sensors positioned adjacent to each other, and a peripheral circuit for causing the pixels sequentially emit light in accordance with a predetermined pattern and sensing the reflected light from the optical sensors to perform a scanning operation do.

The predetermined pattern causes the photosensors belonging to each of the pixels to emit light at a predetermined distance interval that is not interfered with light emitted from adjacent pixels.

19 is a block diagram of a display device according to embodiments of the present invention.

Referring to Fig. 19, the display device 1 may display an image or the like, and may sense a touch contact of a subject such as a human finger or a touch pen. The display device 1 can be implemented in a mobile device such as a desktop, a notebook, a tablet PC, a smart phone, and the like.

The display device 1 includes a cell array 10, a gate driver 20, a source driver 30, an analog front end (AFE) 40, a signal processor 50, a control logic 60, And a memory 70.

The cell array 10 includes a plurality of unit pixels arranged in a plurality of rows and columns, and a unit photo sensor adjacent to each unit pixel. Each unit pixel displays an image according to the light emitted from the backlight unit. The photosensor senses the reflected light from the subject with respect to the light emitted from the unit pixel and scans the surface of the subject. A detailed description of the unit pixel and the photosensor will be given later in FIG.

The gate driver 20 accesses each unit pixel or photo sensor included in the cell array 10 row by row. The gate driver 20 sequentially enables each row when displaying an image. The gate driver 20 sequentially enables at least two rows according to a predetermined pattern when scanning a subject.

The source driver 30 is connected to each unit pixel included in the cell array 10, and when receiving image data, it enables all the columns and outputs an image. At this time, the output image may be updated frame by frame.

The AFE 40 is connected to each optical sensor included in the cell array 10 and sequentially activates at least two or more columns in accordance with a predetermined pattern to scan reflected light from the surface of the subject, And outputs it as data. The AFE 40 may include a sample and hold circuit, an analog to digital converting circuit, and the like.

The signal processor 50 processes the scanning data received from the AFE 40 and outputs it to the host.

The control logic 60 controls each component. That is, the gate driver 20, the source driver 30, the AFE 40, and the signal processor 50. At this time, the control logic 60 can control the operation of each component based on the information stored in the memory 70.

The memory 70 stores information necessary for the operation of the display device 1. [ For example, pattern information on the enable operation of the gate driver, the source driver, and the AFE, information on interruption occurrence, and the like. Further, the memory 70 may store information (for example, fingerprint information) and the like to be registered based on the scanning data.

20 shows a circuit diagram of a photosensor of a comparative example.

20, the optical sensor 100 included in the cell array 10 includes a plurality of transistors (Reset, AMP gm, READ), a photodiode (pin), and a capacitance Cap.

The optical sensor 100 includes a reset transistor connected to the supply voltage terminal VDD, a photodiode connected between the reset transistor and the ground voltage terminal, an amplifying transistor AMP connected to one end of the reset transistor, gm), a parasitic capacitance Cap generated between one end of the reset transistor and a ground voltage terminal, and an output transistor READ connected to the amplification transistor and the drain terminal.

When the gate driver 20 is enabled, the photosensor 100 resets the photodiode first through the reset transistor (Reset), and then receives reflected light from the subject for a predetermined period of time. The received reflected light is converted into an electrical signal by the photodiode, amplified by gm times through the amplification transistor, and then output as the sensed data Iout through the output transistor when the lead-out enable signal is applied. More details are the same as those known in the art for photo sensors.

21 is a cross-sectional view illustrating a unit pixel and a unit optical sensor according to embodiments of the present invention.

21, a unit pixel includes a circuit board (not shown), a backlight unit (not shown) formed on a circuit board, a polarizer formed on a backlight unit and glass, a liquid crystal formed on the glass, , A color filter, a cover glass, and a polarizing plate. Since the laminated structure is realized as known in the art, a detailed description thereof will be omitted and a description will be mainly given to a portion related to the present invention.

When an image is displayed, the light emitted from the backlight unit passes through the polarizing plate and the glass and passes through the color filter. At this time, the color filter filters the light of the backlight unit to transmit only a specific color. For example, the R filter transmits red light, the G filter transmits green light, and the B filter transmits blue light. The image is displayed on the display screen in combination with red light, green light or blue light. That is, the unit pixel 100 includes sub-pixels of R filter, G filter, and B filter, and each unit pixel includes a TFT (Thin Film Transistor) located between the lower end of each of the R filter, the G filter, Respectively. At this time, the gate driver 10 and the source driver 20 are sequentially enabled in the cell array 10 and output in frame units.

On the other hand, when a subject such as a finger or a touch pen is scanned, the light emitted from the backlight unit passes through the polarizing plate, the glass, the color filter, the glass, and the polarizing plate is reflected from the surface of the subject, And is incident on an optical sensor positioned adjacent to the TFT. As shown in FIG. 2, the optical sensor converts reflected light into an electrical signal and outputs it as scanning data. At this time, the optical sensor is connected to the gate driver 10 and the AFE 20, and is sequentially enabled in a predetermined pattern in the cell array 10 to output scanning data.

More specifically, the photosensors are positioned adjacent to the sub-pixels, and when one of the photosensors is enabled, neighboring optical sensors are disabled within a predetermined minimum distance. The light from the backlight unit passes through the color filter adjacent to the enabled light sensor and is emitted to the subject. The reflected light from the subject is received by the photo sensor at the lower end of the color filter, converted into scanning data, and output. At this time, the TFTs of adjacent sub-pixels within a predetermined minimum distance from the enabled optical sensor should be disabled. And to reduce the interference light to the enabled optical sensor to more accurately sense the reflected light.

In addition, one surface of the glass substrate positioned above the unit pixels of the display device 10 may further include a shape having irregularities. In other words, the convex lens shape can be implemented on the optical sensor so that the reflected light can be better collected every time the optical sensor is enabled.

In addition, one surface of the polarizing plate positioned above the unit pixels of the display device 10 may be formed with a convex lens or with a concavo-convex shape. A convex lens on the surface of the polarizing plate on which the subject is in contact can guide reflected light from the subject to be collected by the optical sensor.

22 is an enlarged cross-sectional view of one embodiment of the sub-pixel shown in FIG.

22, the sub-pixel 200 includes a lower glass substrate, a photosensor, a TFT, a liquid crystal layer, a color filter, a black matrix (BM), and a top glass substrate.

The photosensor and the TFT may be located on the same plane on the lower glass substrate. However, the embodiment of the present invention is not limited to this, and the photosensor may be located at the upper or lower end of the TFT. A description will be made mainly of a case where it is formed on the same plane for convenience of explanation.

A liquid crystal layer is located on the photosensor and the TFT, and the color filter and the BM are located on the same plane on the liquid crystal layer. Between the color filters, that is, between the R filter, the G filter, and the B filter, the BM portion is located. At this time, the BM unit includes an open window for intensively collecting the reflected light from the object while excluding the interference light through the polarizing plate or glass.

The TFT is positioned at the lower end of the color filter, and activates the liquid crystal layer so that light emitted from the backlight unit is output to the screen. At this time, only the enabled TFT is activated to emit light through the color filter, and adjacent TFTs are disabled to generate unnecessary interference light, so that reflected light is not scattered.

A photosensor adjacent to the enabled TFT is positioned at the lower end of the open window and receives and senses only light received through the open window.

FIG. 23 is an enlarged cross-sectional view showing another embodiment of the sub-pixel shown in FIG. 21, and FIG. 24 is an enlarged cross-sectional view showing still another embodiment of the sub-pixel shown in FIG. For convenience of description, differences from FIG. 22 will be mainly described.

23 and 24, the upper glass substrate of the sub-pixel 300 may include a concavo-convex structure capable of functioning as a convex lens corresponding to the open window portion.

When the concavoconvex structure is formed in the open window portion, the incident light can be more concentrated in the light receiving region of the photosensor without scattering out of the photosensor as shown in the figure.

23 and 24, the photosensor of the sub-pixel 400 may further include a light shielding layer. The light shielding layer may have a narrower opening area than the open window and may be slightly wider than the light receiving area of the photosensor. In this case, scattered light from the liquid crystal layer or adjacent sub-pixels is shielded through the light shielding layer, and the photosensor can receive only the reflected light incident through the open window in the light receiving area.

That is, the present invention can realize at least any one of the open window of the BM part, the concavo-convex structure of the upper glass substrate, and the light shielding layer of the optical sensor to further increase the light receiving efficiency of the optical sensor. The better the light-receiving capability of the photo sensor, the better the object scanning performance of the display device 1 is.

25 and 26 are conceptual diagrams illustrating a method according to an embodiment in which the display device of the present invention scans an object.

Referring to FIG. 25, the display device may enable only pixels of predetermined intervals to scan a subject, emit light to the subject, and receive reflected light from the subject. Wherein the predetermined interval means a minimum distance at which the emitted light from the enabled pixel does not cause an interference light effect on the photosensor light sensor of another adjacent pixel.

When an image is displayed, pixels are sequentially enabled from (x1, y1) to (x6, y5) in a 6 x 5 cell array structure to output an image frame by frame.

On the other hand, when a subject is scanned, pixels of (x2, y1), (x2, y4) coordinates are enabled to emit light in a 6 x 5 cell array structure as shown in Fig. 25 And receives reflected light. Subsequently, as shown in Fig. 25 (b), the second row, third row and fourth row are successively scanned in accordance with the pattern (x5, y1), and the unitsize of (x5, y4) And receives reflected light from the subject. Here, the distance between the pixels of (x2, y1) and (x2, y4) is a distance at which the influence of the interference light can be minimized.

More specifically, the primary pixels emit light according to a pattern spaced at predetermined intervals, and the photosensor light sensors receive the reflected light (Fig. 26 (a)). Then, the pixels emitted at the first order are disabled, the pixels indicated by the thick line are secondarily emitted, and the photosensor photosensors receive the reflected light (Fig. 26 (b)). Likewise, the pixels that are emitted in the first order are disabled, and the pixels in the thick line are emitted in a tertiary manner, and then the photosensor light sensors receive the reflected light (Fig. 26 (c) The pixels receive light and photosensor light sensors (Fig. 26 (d)).

In other words, from FIG. 26 (a) to FIG. 26 (d), the display device sequentially enables the pixels in a predetermined pattern and disables the remaining pixels, thereby sequentially collecting the reflected light from the photosensor light sensor do. As a result, as shown in FIG. 26 (d), reflected light is collected on the entire display screen to obtain scanning data, and the scanning data can store information on the surface of the object in one frame in a memory.

FIG. 27 is a signal diagram showing the operation of the gate driver and the source driver when the display device of the present invention is displayed, and FIG. 28 shows the operation of the gate driver and the source driver when the display device of the present invention scans an object. It is a signal diagram.

27A, in the case of the display operation, the gate driver 20 sequentially enables the TFTs in each row of the cell array 10 so as not to overlap with each other, as shown in FIG. 27B, , The source driver 30 activates the RGB pixels sequentially by sequentially or simultaneously enabling the entire columns to output an image to the screen. At this time, the gate driver 10 and the source driver 20 do not enable the corresponding row until the entire frame of the screen is output.

On the other hand, referring to FIG. 28 (a), the scanning operation operates differently from the operation of the gate driver 10 and the source driver 20 of FIG.

More specifically, according to a predetermined pattern stored in the memory 70, the gate driver 10 can be enabled at regular intervals for each row even if the frame input of the entire screen is not completed, So that the enable section can be overlapped.

Also, the source driver 20 can enable pixels at all of the predetermined intervals according to a predetermined pattern without enabling the pixels of all the columns. At this time, the photosensor may also enable only the photosensor light sensor adjacent to the enabled pixel by referring to the column information enabled by the source driver 20. [ That is, pixels of the cell array and photosensor photosensor may be enabled according to a predetermined pattern to obtain a surface image of the subject in a predetermined pattern.

As a result, the display device can not only output an image or the like to a screen but also obtain information on whether or not the object is in contact with the object and surface information of the object. In addition, the display device according to the embodiments of the present invention does not need to laminate the electrostatic touch screen panel, which is advantageous in that the thickness is thinner.

29 is a conceptual diagram illustrating a method according to another embodiment of the present invention in which the display device scans an object.

Referring to FIG. 29, a light source in a display device is enabled at a predetermined interval to scan a subject to emit light to a subject. Here, the light source is used not only as a light source that emits light itself but also as a pixel of a liquid crystal display, such as a pixel of an organic light emitting diode display, and includes a light source realized by controlling the transmission and brightness of backlight. For convenience of explanation, the difference from the above-described case will be mainly described. In this case, the entire photosensor optical sensor included in the sensor array is enabled.

When both photosensor photosensors are enabled, the photosensor photosensor, which is at a distance of a predetermined distance R from the same light source of the photosensor photosensor, receives reflected light and scattered light by the reflected light. At this time, the first photosensor photosensor, which is spaced apart from the light source by a predetermined distance f (assuming f <R in this case), receives the most reflected light, and the second photosensor light around the first photosensor photosensor Sensors receive scattered light by reflected light. That is, the sensing value of the first photosensor photosensor may be greater or less than the sensed value of the second photosensor photosensors.

For convenience of explanation, it is assumed that X1 and X2 shown in FIG. 29 are photosensor optical sensor coordinates having distances with which influence of scattered light is minimized. It is also assumed that one frame is scanned until all of the light sources in all the regions are turned on by turning on some light sources at predetermined intervals at which the influence of scattered light is minimized.

For example, when the fingerprint valley corresponds to the position of X1, the distance from the light source to the photosensor sensor layer is the farthest. Therefore, when the light source corresponding to the X1 position is turned on, And receives the least amount of reflected light. However, the photosensor photosensors y1 to y8 within the distance closest to X1 receive scattered light of a larger amount of light than the photosensor photosensor of X1. At this time, the photosensor photosensors of X1 and y1 to y8 will have a larger difference in the amount of light received without scattering light. However, due to the scattered light due to the difference in refractive index between the photosensor photosensor and the subject, (Hereinafter referred to as &quot; delta value &quot;) between photosensor photosensors of y1 to y8 tends to be small. That is, when the sensing value of the photosensor light sensor X1 is smaller than the average sensed value of the photosensor light sensors y1 to y8, the display device determines that the corresponding area corresponds to the goal of the fingerprint.

As another example, when the ridge of the fingerprint corresponds to the position of X2, the distance from the light source to the photosensor sensor layer is closest. Therefore, when the light source corresponding to the X2 position is turned on, The most of the reflected light is received. However, the photosensor photosensors of z1 to z8 within the distance closest to X2 receive scattered light of less light intensity than the photosensor photosensor of X2. At this time, the delta value between the photosensor photosensor of X2 and the photosensor photosensors of z1 to z8 tends to be small because of the scattered light due to the refractive index difference in the intermediate medium layer between the photosensor photosensor and the subject. That is, when the sensed value of the photosensor light sensor X2 is smaller than the average sensed value of the photosensor light sensors z1 to z8, the display device determines that the corresponding area corresponds to the ridge of the fingerprint.

The ambient photosensor light sensors y1 to y8, or z1 to z8, except for the photosensor light sensor of coordinates (X1 or X2) corresponding to the light source in the extracted raw partial images, It is necessary to remove the scattered light component with noise before synthesizing the whole image. In the case of X2, since the degree of blurring of the original part image is small due to the scattered light due to the ridge value of the fingerprint, the noise component is not separately deducted. However, in the case of X1, the scattered light from the intermediate medium is additionally incident on the photosensor optical sensor X1 even though only the reflected light should be incident because the influence of scattered light on the fingerprint is greater than that of the fingerprint ridge. Therefore, the noise component at X1 must be subtracted from the sensing value. That is, when synthesizing the first original partial images obtained according to the first light source arrangement and the second original partial images obtained according to the second light source arrangement to synthesize the entire image, y1 The average values of the sensed values of the adjacent photosensor photosensors that are farther from the photosensor photosensor than the photosensor photosensor are arbitrarily subtracted from the photosensor photosensor sensed values of X1, y1 to y2. As a result, the sensing delta value between the ridge area of the fingerprint and the fingerprint area becomes larger, and a more accurate whole image can be obtained.

30 is a conceptual diagram showing a method according to another embodiment in which the display device of the present invention scans an object;

Referring to FIG. 30, the light source may be turned on and scanned on a line-by-line basis. More specifically, the light source is sequentially turned on from the first column to the Nth column in a line unit, and the light source is sequentially turned on from the first row to the Mth row after the partial image is sensed, and the partial image can be sensed .

In this case, when the light source is turned on in the column direction, only the scattered light between the previous row and the next column can be considered. When the light source is turned on in the row direction, only the scattered light between the previous row and the next row can be considered.

Referring to FIG. 30 (a), if the sensing value of the coordinates (x3, y5) in the first partial image sensed when the light source of the third column (x3) is turned on is a case where both the reflected light and the scattered light are sensed, Since the sensing value of the coordinates (x3, y5) in the second partial image sensed when the four light sources are turned on is the scattered light only sensed, the sensed value of the second partial image is added or subtracted from the sensed value of the first partial image, A fingerprint image can be obtained. As another example, when adjusting the offset of the fingerprint sensing value, the scattered light value sensed at a distance far from the x3 coordinate when the light source of the third row is turned on may be added or subtracted from the corresponding coordinate sensing value of the second partial image. As another example, as described in the second case, since the distance between the subject and the photosensor sensor is longer than that of the fingerprint ridge, the influence of the scattered light is larger. Therefore, Value may be added or subtracted.

30B, a light source is sequentially turned on and scanned in the row direction to obtain a fingerprint pattern image considering scattered light in the row direction, and the final full fingerprint pattern image is obtained by combining the entire column direction composite image and the entire row direction A composite image can be obtained and synthesized.

31 is a conceptual diagram showing a method according to another embodiment in which the display device of the present invention scans an object;

Assume, in accordance with one embodiment, that the colored coordinates in Figs. 31 (a) and 31 (b) are the first light source, and the colorless coordinates are the second light source. The first light source and the second light source have coordinates of different wavelength bands.

As shown in FIG. 31 (a), when the first light source spaced by a predetermined distance that minimizes the influence of the scattered light is turned on, the photosensors in the sensor array receive the reflected light of the first wavelength band, do.

31 (b), when the second light source spaced by a predetermined distance to minimize the influence of the scattered light is turned on, the photosensors in the sensor array receive the reflected light of the second wavelength band, Sensing.

Similarly, when the first light source and the second light source, which are spaced apart by a predetermined distance, are sequentially turned on alternately, the photosensor array acquires the first image and the second image, which are sensed within one frame, respectively. Since the influence of the reflected light / scattered light received depends on the refractive index in the intermediate medium layer between the photosensor light sensor and the object as well as the wavelength band of the light, the first image and the second image are synthesized, Can be obtained.

For convenience of explanation, the case of using two light sources has been described. However, the embodiment of the present invention is not limited thereto. In another embodiment, after three light sources of R, G and B are irradiated by the method of the embodiment, It is also possible to obtain the final fingerprint image by combining all the images obtained with the image, the G image and the B image.

31 (a) and 31 (b), according to another embodiment, do not use light sources of different wavelength bands, but use the same light source, but are arranged as photosensor light sensors deposited to receive reflected light of different wavelength bands . That is, all the photosensor optical sensors in the sensor array are the same, but the color coordinates can be arranged by depositing a substance that filters light in a specific wavelength band on the photosensor photosensor, and the colorless coordinates do not deposit the substance. As a result, the photosensor array acquires a first image sensed in color coordinates sensed within one frame and a second image sensed in colorless coordinates, respectively. Since the influence of the reflected light / scattered light received depends on the refractive index in the intermediate medium layer between the photosensor light sensor and the object as well as the wavelength band of the light, the first image and the second image are synthesized, Can be obtained.

In the modified embodiment of FIG. 31, it is assumed that the target fingerprint of the same user is scanned by using different light sources of various wavelength bands in the following fingerprint authentication process. In this case, a light source of a wavelength band for outputting a fingerprint image having a higher degree of similarity than each light source and a scanning arrangement mechanism of the light source are stored in association with the user fingerprint information in comparison with the previously registered fingerprint information. Sensing can be performed.

In yet another embodiment,

The first fingerprint image using the total reflection of the light guide plate by the first light source on the side is scanned. Then, the second fingerprint image using the reflected light of the second light source at the lower end is sequentially scanned. The display device synthesizes the first fingerprint image and the second fingerprint image to generate a final full fingerprint image. In this case, the quality of the final entire fingerprint image can be improved by using another light source irradiation method.

Hereinafter, with respect to a sensor driving circuit configured in a matrix form to drive a plurality of optical sensors (optical sensors) included in the optical sensor array and read out the sensed signals from the optical sensors in the above-described embodiments, Various embodiments will be described.

32 is a diagram showing a configuration of an optical sensor array for implementing fingerprint sensing or image scanning functions according to an embodiment of the present invention.

The optical sensor array includes a plurality of scan lines SL1, SL2, ..., SLn and a plurality of lead-out lines RL1, RL2, ..., RL1. A scan signal is sequentially supplied to the plurality of scan lines SL1 to SLn and the plurality of lead-out lines RL1, RL2, ..., and RL1 receive signals output from the optical sensor SN, To a processing circuit (not shown).

The scan lines SL1, SL2, ..., SLn and the lead out lines RL1, RL2, ..., RL1 are arranged so as to intersect with each other. At least one optical sensor SN may be formed at each intersection thereof.

Fig. 33 is a circuit diagram showing an embodiment of the optical sensor SN shown in Fig. 22. Fig. Referring to FIG. 33, the optical sensor SN includes a photodiode PD, a transistor T1, and a sensing capacitor C0.

The photodiode PD is an element that converts light energy into electric energy, and when the light touches the photodiode PD, current flows. The cathode of the photodiode PD is connected to the source of the switch transistor T1, and the anode is connected to the ground potential. Such a photodiode PD may be implemented by an organic light emitting diode (OLED), a quantum dot (QD), a transistor, or the like.

One end of the sensing capacitor C0 is connected to the source of the switch transistor T1 and the other end of the sensing capacitor C0 is connected to the ground potential. Responses to the change of the potential at one end of the sensing capacitor C0 are transmitted to the lead out lines RL1 and RL2 and the signals transmitted to the lead out lines RL1 and RL2 are transmitted to a predetermined IC chip. The gate electrode of the switch transistor T1 is connected to the scan lines SL1 to SLn, the drain electrode thereof is connected to the lead-out lines RL1 and RL2, and the source electrode thereof is connected to the cathode of the photodiode PD.

The switch transistor T1 may be formed of a transistor such as a hydrogenated amorphous silicon (a-Si: H), a poly silicon (Poly-Si), or an oxide transistor. However, the present invention is not limited to this, and it may be implemented by an organic thin film transistor (Organic TFT) or the like.

A method of sensing the light incident from the outside, that is, the light sensor SN, which is reflected by the contact means and is incident on the optical sensor SN, and transmits a signal corresponding to the size of the sensed light will be described below. Respectively.

A predetermined voltage is applied to the lead-out lines RL1 and RL2. A separate circuit (not shown) for voltage application may be further included. When the selection signal for turning on the switch transistor T1 is applied to the scan lines SL1 to SLn, the one end potential V1 of the sensing capacitor C0 is set to the voltage applied to the lead-out lines RL1 and RL2 . That is, due to the turn-on of the switch transistor T1, the sensing capacitor C0 is set to the voltage applied to the lead-out lines RL1 and RL2.

If light reflected from an external object is not incident, a current does not flow through the photodiode PD, so that the one end potential V1 of the sensing capacitor C0 is maintained at the set voltage.

The lead-out lines RL1 and RL2 are reset to a predetermined period. After the lead-out lines RL1 and RL2 are reset to, for example, 0 V, the next selection signal is input to the scan lines SL1 to SLn When the switch transistor T1 is turned on, the charge stored in the sensing capacitor C0 is shared with the parasitic capacitance (not shown) of the lead-out lines RL1 and RL2.

Assuming that the voltage applied to the lead-out lines RL1 and RL2 is Vdc, the parasitic capacitance of the lead-out lines RL1 and RL2 is Cpl and the potential at one end of the sensing capacitor C0 is V1, the following equation is established.

However, when light reflected from an external object is incident, a current flows through the photodiode PD. Accordingly, a difference occurs in the total amount of charges shared by the parasitic capacitance of the sensing capacitor C0 and the lead-out lines RL1 and RL2. In the equation (1), the potential V1 at one end of the sensing capacitor Will be different.

The magnitude of the current flowing through the photodiode PD is increased as the intensity of the incident light is increased so that the amount of change of the potential V1 at the one end of the sensing capacitor C0 is also increased and the sensing capacitor C0 and the lead out lines RL1 and RL2 The total amount of charge shared between the parasitic capacitances of the first and second transistors is also increased. Therefore, output signals of different levels are obtained from the lead-out lines RL1 and RL2 according to the intensity of light incident on the photodiode PD.

The above-described method utilizes charge sharing phenomenon between the sensing capacitor C0 and the parasitic capacitance of the lead-out lines RL1 and RL2. Therefore, the level difference of the output signal obtained from the actual lead-out lines RL1 and RL2 is a difference between the result of the charge sharing with the sensing capacitor C0, and accordingly, the level of the output signal The level difference may not be large enough. Therefore, a separate circuit for amplifying the output signals of the lead-out lines RL1 and RL2 is required.

34 is a circuit diagram showing another embodiment of the charge sharing scheme for the optical sensor SN of Fig.

Referring to FIG. 34, the optical sensor SN may include a switching transistor Tl, a sensing transistor PT1, and a sensing capacitor C0.

The gate electrode of the switching transistor T1 is connected to the scan line SL, the drain electrode thereof is connected to the lead-out line RL and the source electrode thereof is connected to the first one of the electrodes of the sensing capacitor C0. On the other hand, the drain electrode of the sensing transistor PT1 is connected to the input voltage line VDD, the source electrode thereof is connected to the first electrode of the sensing capacitor C0, and the gate electrode thereof is connected to the common voltage line Vcom.

When light reflected from an external object is supplied to the sensing transistor PT1, a semiconductor of a channel portion made of amorphous silicon or polycrystalline silicon forms a current. This current is detected by an input voltage inputted to the input voltage line VDD And flows in the direction of the capacitor C0 and the switching transistor T1.

When the selection signal is inputted to the scan line SL, the current flows through the lead-out line RL. At this time, the parasitic capacitance formed around the lead-out line RL inevitably leads to a reduction in the amount of current flowing to the lead-out line RL.

FIG. 35 is a circuit diagram showing the configuration of a charge-shaking type optical sensor applicable to a display device according to an embodiment of the present invention.

The optical sensor SN according to an embodiment of the present invention may be included in the optical sensor array as described above.

Each optical sensor SN comprises only one sensing transistor PT1. The sensing transistor PT1 generates a charge amount corresponding to the intensity of light reflected from an external object. In other words, the sensing transistor PT1 receives light reflected from an external object and generates a leakage current corresponding to the intensity of the received light.

The electrostatic capacitance C1 shown in FIG. 35 is not actually provided, and the parasitic capacitance caused by the intersection of the signal lines of the readout line and the scan line, that is, the gate-source overlap capacitance of the TFT, Cgso ).

The first electrode of the sensing transistor PT1 is connected to the scan lines SL1 to SLn and the second electrode of the sensing transistor PT1 is connected to the lead-out lines RL1 and RL2. The third electrode may be arranged in a floating state that is not electrically connected to any component. The first electrode, the second electrode, and the third electrode may be a gate electrode, a drain electrode, and a source electrode, respectively. The sensing transistor PT1 may be implemented as a transistor such as a hydrogenated amorphous silicon (a-Si: H), a poly silicon (Poly-Si), or an oxide transistor. However, the present invention is not limited to this, and it may be implemented as an organic thin film transistor (Organic TFT)

36 is a timing chart for explaining the operation of the charge-sharing optical sensor SN according to an embodiment of the present invention. The operation of the charge sharing type photosensor (SN) according to an embodiment of the present invention will be described with reference to FIGS. 35 and 36. FIG.

In Fig. 36, SL represents a signal supplied to the scan lines SL1 to SLn, and it should be understood that a select signal is supplied to the scan lines SL1 to SLn during a high period. The specific optical sensor SN is selected by application of the selection signal, and a signal from the optical sensor SN is output. Hereinafter, 'SL' will be referred to as a scan line signal. RL Reset is a signal for resetting the lead-out lines RL1 and RL2, and a reset signal is supplied in a high period to reset the lead-out lines RL1 and RL2.

V1 represents the source electrode potential of the sensing transistor PT1 and R1 represents the potential at the point where the drain electrode of the sensing transistor PT1 is connected to the lead-out lines RL1 and RL2. In the timing charts of V1 and R1, the solid line indicates the case where the light reflected by the external object is not supplied to the sensing transistor PT1 (dark), and the dashed line indicates that the light reflected by the external object is sensed (Light) when supplied to the transistor PT1. The external object may be a touch generating means or a human fingerprint. The finger of a person includes ridges and valleys, and different amounts of light are reflected depending on whether a ridge touches or touches each sensing transistor PT1.

The period from when the scan line signal SL becomes a high level to a next high level can be defined as one frame. Coupling occurs due to the parasitic capacitance C1 in the section T2 in which the high level signal is applied to the scan lines SL to SLn and the potential V1 of the source electrode of the sensing transistor PT1 also rises . Specifically, the potential of the scan lines SL to SLn rises due to the application of the high-level signal, whereby the source electrode potential V1 of the sensing transistor PT1 is also increased by the coupling phenomenon of the parasitic capacitance C1 It will rise together. Thereafter, when the scan line signal SL falls to the low level, the source electrode potential V1 of the sensing transistor PT1 also falls due to the coupling phenomenon of the parasitic capacitance C1, and can be reset to the initial value .

First, a case where light reflected by an external object is not supplied to the sensing transistor PT1 will be described as follows. A leakage current is not formed in the sensing transistor PT1 because the light is not supplied to the sensing transistor PT1. Accordingly, in the section T1 in which the scan line signal SL is maintained at the low level, the parasitic capacitance C1 The charge is not charged.

Referring to the timing chart V1 shown by the solid line in FIG. 36, when the scan line signal SL is switched to the high level (T2), the source electrode potential V1 of the sensing transistor PT1 is also coupled to the scan line signal (SL).

Thereafter, when the lead-out-line reset signal RL Reset is switched to high during a period during which the scan-line signal SL has fallen to the low level again (T3), the lead- The potentials RL1 and RL2 of the sensing transistor PT1 are reset to the reset voltage and accordingly the source electrode potential V1 of the sensing transistor PT1 is also reset to fall to the low level as indicated by the V1 timing shown by the solid line in Fig. At this time, the source electrode potential V1 of the sensing transistor PT1 may be lower than the low level due to the coupling phenomenon between the scan line signal SL and the source electrode of the sensing transistor PT1.

According to this principle, since the potential of the scan line signal SL and the source electrode potential V1 of the sensing transistor PT1 are always kept at the same level, the parasitic capacitance C1 is not charged, No current flows into the lead-out lines RL1 and RL2 even when the signal SL is at the high level. Accordingly, the potential R1 at the point where the sensing transistor PT1 and the lead-out lines RL1 and RL2 are connected is maintained at the same level when the scan line signal SL is at the high level and at the low level.

Next, a case where light reflected by an external object is supplied to the sensing transistor PT1 will be described. The parasitic capacitance C1 is charged by the leakage current of the sensing transistor PT1 formed by the light even in the section T1 where the scan line signal SL is held at the low level. Accordingly, the source electrode potential V1 of the sensing transistor PT1 gradually rises as shown by the timing V1 shown by the broken line in Fig.

The source electrode potential V1 of the sensing transistor PT1 rises due to the coupling phenomenon of the parasitic capacitance C1 when the scan line signal SL is switched to the high level T2, Since the capacitance C1 is charged, the potential V1 of the parasitic capacitance C1 is relatively high at the beginning of the T2 period as compared with the case where no light is supplied. That is, as compared with the case where there is no reflected light, since the parasitic capacitance C1 is charged during the T1 period, a difference occurs in the value of the potential rising due to the coupling phenomenon depending on the difference value of the charged amount.

On the other hand, in the T2 period, as the scan line signal SL becomes a high level, the charges charged in the parasitic capacitance C1 are transmitted to the lead-out lines RL1 and RL2 through the sensing transistor PT1, The potential R1 at the point where the sensing transistor PT1 and the lead-out lines RL1 and RL2 are connected to each other, that is, the drain electrode potential R1 of the sensing transistor PT1 gradually increases (A section) The source electrode potential V1 of the sensing transistor PT1 gradually decreases (ⓑ section) because the amount of the charged charges of the capacitance C1 is reduced. This is because the source electrode potential V1 of the sensing transistor PT1 becomes lower than the drain And proceeds until it becomes equal to the potential R1 of the electrode.

When the reset signal RL Reset is input to the lead-out lines RL1 and RL2, the potential R1 of the lead-out lines RL1 and RL2 gradually decreases to maintain the scan line signal SL at a low level It is lowered to the same level (ⓑ section). The reset signal RL Reset signal of the lead-out lines RL1 and RL2 is periodically supplied, whereby the potential R1 of the lead-out lines RL1 and RL2 can be periodically reset. The period during which the potential R1 of the lead-out lines RL1 and RL2 is reset may be shorter than the time during which the high-level signal, i.e., the selection signal, is supplied to the scan line signal SL.

When the scan line signal SL is switched to the low level (T3), the parasitic capacitance C1 is charged again by the leakage current formed by the sensing transistor PT1.

When the light reflected by the external object is supplied to the sensing transistor PT1, the parasitic capacitance C1 is charged by the leakage current. During the interval in which the scan line signal SL is at the high level, The increase in width of the source electrode potential V1 becomes larger than that in the normal case (when no light is supplied). Accordingly, in the section (a section) before the lead-out lines RL1 and RL2 are reset, the potential R1 pattern at the point where the drain electrode of the sensing transistor PT1 and the lead-out lines RL1 and RL2 are connected Also, it is different from the usual case.

Therefore, the drain electrode potential R1 of the sensing transistor PT1 or the sensing potential of the sensing transistor PT1 in the section (a section) before the scan line signal SL is maintained at the high level and the lead-out lines RL1 and RL2 are reset, The variation of the potential R1 of the point where the transistor PT1 and the lead-out lines RL1 and RL2 are connected and more broadly the potentials R1 and RL2 of the lead-out lines RL1 and RL2 are observed, It is possible to judge whether or not the supplied light is supplied.

Since the amount of the leakage current from the sensing transistor PT1 accumulated in the parasitic capacitance C1 also varies depending on the amount of the supplied light, the change in the potential R1 of the lead-out lines RL1 and RL2 in the section? So that it is possible to grasp the state of the contact (such as the contact strength or the contact area). In other words, the amount of charge charged in the parasitic capacitance C1 varies depending on the leakage current formed by the sensing transistor PT1. However, since the charged amount of charge is gradually shifted to the lead-out lines RL1 and RL2 when a selection signal is applied , And the corresponding output signal is output from the sensing transistor PT1. By detecting this through the lead-out lines RL1 and RL2, it is possible to grasp the contact state of each of the light sensors SN.

If the change pattern of the potential R1 detected by the lead-out lines RL1 and RL2 is transmitted to a separate IC chip, it is possible to judge whether or not a screen is in contact with the corresponding pixel, . In other words, the lead-out lines RL1 and RL2 receive a signal corresponding to the amount of charge charged in the parasitic capacitance C1 by the leakage current of the sensing transistor of the photosensor SN as a potential, The contact state and the contact state can be determined.

According to the embodiment of the present invention, only one sensing transistor PT1 is provided in the charge-sharing type optical sensor SN. This means that one transistor and one capacitor are used less than the optical sensor of FIG. 33 described above. As described above, the optical sensor SN is formed on the substrate having the display area. As the number of elements constituting the optical sensor SN is reduced for the above reason, the aperture ratio in the entire display panel is remarkably improved .

33, the source electrode potential V1 of the sensing transistor PT1 must be periodically reset. However, according to the embodiment of the present invention, The reset signal is reset by the lead-out line reset signal RL Reset applied to the lead-out lines RL1 and RL2 in the low-level period of the selection signal applied to the lines SL1 to SLn, Thus, the area of the integrated circuit can be reduced. In the optical sensor integrated type display device, since the optical sensor is provided for each pixel of the display device, the contact area and the contact area for each pixel can be checked. According to the present invention, fingerprint recognition can be performed by determining whether a ridge or a ridge of a fingerprint is touched for each pixel when a user's finger touches not only the touch generated by the touch generating means, but also the point of generating the touch. In other words, by forming the size of each of the optical sensors integrated in the display device and the interval between them to be small enough to distinguish the ridge and the valley of the fingerprint finger, both touch detection and fingerprint recognition are possible on the display device, The resolution can be naturally improved.

37 is a circuit diagram showing an embodiment of a source follower scheme for the optical sensor of Fig.

37, the source-follower optical sensor SN includes one photodiode PD, three transistors T1, T2, and T3, and one sensing capacitor C1.

The first transistor T1 is a transistor T1 for resetting the first electrode potential V1 of the sensing capacitor C1 according to a reset control signal Reset and is hereinafter referred to as a reset transistor T1. The source electrode of the reset transistor T1 is connected to the cathode of the photodiode PD and the drain electrode is connected to the input voltage line VDD.

The gate electrode of the second transistor T2 is connected to the cathode of the photodiode PD and the first electrode of the two electrodes of the sensing capacitor C1. Also, the drain electrode of the second transistor T2 is connected to the input voltage line VDD. The second transistor T2 converts the first electrode potential V1 of the sensing capacitor C1 into a current signal and amplifies the current signal. Therefore, the second transistor T2 can be referred to as an amplifying transistor T2.

The gate electrode of the third transistor T3 is connected to the scan line SL, the drain electrode thereof is connected to the source electrode of the amplification transistor T2 and the source electrode thereof is connected to the lead-out line RL. When the selection signal is applied to the scan line SL, the third transistor T3 is turned on and the first electrode potential V1 of the sensing capacitor C1 amplified by the amplifying transistor T2 is applied to the current signal To the lead-out line RL. The third transistor T3 may be referred to as a selection transistor T3.

The cathode and the anode of the photodiode PD are respectively connected to the first electrode and the ground potential of the sensing capacitor C1 and the first and second electrodes of the sensing capacitor C1 are connected to the gate electrode of the amplifying transistor T2 Respectively.

The operation of the source follower type optical sensor will be described below.

First, when the reset transistor T1 is turned on by the reset control signal Reset, the potential of the first electrode potential V1 of the sensing capacitor C1 and the potential of the input voltage line VDD are reset.

When light reflected by an external object (e.g., a fingerprint of a person's finger) is supplied to the photodiode PD, a leakage current is generated, and the leakage current can charge the sensing capacitor C1 .

When the sensing capacitor C1 is charged, the gate electrode potential of the amplifying transistor T2 connected to the first electrode of the sensing capacitor C1 is increased. When the potential exceeds the threshold voltage, the amplifying transistor T2 The transistor T2 is turned on, and thus the current flows through the amplifying transistor T2.

When the selection transistor T3 is turned on by applying the selection signal to the scan line SL, the first electrode potential V1 of the sensing capacitor C1 through the amplifying transistor T2 and the selection transistor T3 Is amplified and transmitted as a current signal to the lead-out line RL. The lead-out line RL potential R1 rises due to the current transfer to the lead-out line RL, and the change in the value of the lead-out potential R1 when the selection signal is applied to the scan line SL And is converted into a digital signal through an analog-to-digital converter (ADC).

The potential R1 of the lead-out line RL is proportional to the first electrode potential V1 of the sensing capacitor C1, that is, the amount of charge charged in the sensing capacitor C1 and is stored in the sensing capacitor C1 Since the charge amount is proportional to the amount of light supplied to the photodiode PD, it is possible to grasp how much light is supplied to the photosensor SN through the lead-out line RL potential R1. Accordingly, it is possible to grasp the contact state and the contact state (contact distance and contact area, etc.) of the object by the optical sensors SN.

The optical sensor of the source follower type described with reference to FIG. 37 outputs a signal amplified by the amplifying transistor T2, so that no additional amplifier is required, and the analog signal can be directly converted into a digital signal to detect the signal, Signal processing is possible. However, since the number of transistors is large, there is a limit of the space that can be integrated in the pixels of the display device, and the aperture ratio is narrow.

38 is a circuit diagram showing a configuration of a source follower type optical sensor applicable to a display device according to an embodiment of the present invention. 38 (a) and 38 (b) are circuit diagrams equivalent to each other. The optical sensor according to this embodiment is basically a source follower type optical sensor.

Referring to FIG. 38, the optical sensor SN according to an embodiment of the present invention may be disposed at the same position as the optical sensor SN described with reference to FIGS. 32 and 33. FIG. According to one embodiment, the photosensor SN may be disposed in a non-overlap region with the transparent portion of the color filter layer when viewed from the top view.

However, when a transparent electrode material is used for the optical sensor SN, it may be overlapped with the transparent portion of the color filter layer in the optical sensor array. According to this, since the optical sensor SN can be formed to cover the unit pixel, the sensitivity of the image scan can be improved by forming the unit optical sensor SN in a large size.

Referring to FIG. 38A, each optical sensor SN includes one P-type transistor PT1, an N-type transistor T1, and a sensing capacitor C1.

Each of the transistors PT1 and T1 may be implemented with a silicon-based transistor such as a hydrogenated amorphous silicon (a-Si: H), a polysilicon (Poly-Si) However, the present invention is not limited to this, and it may be implemented by an organic thin film transistor (Organic TFT) or the like.

The gate electrode and the source electrode of the P-type transistor PT1 are connected to each other and equalized to the photodiode PT1 as shown in Fig. 7 (b). The gate electrode and the source electrode of the P-type transistor PT1 are connected to each other to serve as a cathode of the photodiode PT1, and the drain electrode serves as an anode. The source electrode of the P-type transistor PT1 is connected to the scan line SLn + 1. On the other hand, the drain electrode of the P-type transistor PT1 is connected to the first one of the two electrodes of the sensing capacitor C1 and the gate electrode of the N-type transistor T1.

The gate electrode of the N-type transistor T1 is connected to the first electrode of the sensing capacitor C1 and the drain electrode of the P-type transistor PT1, and the drain electrode thereof is connected to the lead-out line RL. A source electrode of the N-type transistor T1 is connected to the scan line SLn.

The scan line SLn connected to the source electrode of the N-type transistor T1 and the scan line SLn + 1 connected to the source electrode of the P-type transistor PT1 are different adjacent scan lines. The first scan line SLn connected to the source electrode of the N-type transistor T1 and the first scan line SLn connected to the source electrode of the N- A selection signal may be sequentially applied to the second scan line SLn + 1 to which the source electrode of the first transistor PT1 is connected.

On the other hand, the sensing capacitor C1 functions to charge the charge corresponding to the leakage current formed by the P-type transistor PT1. The first electrode of the sensing capacitor C1 is connected to the gate electrode of the N-type transistor T1 and the drain electrode of the P-type transistor PT1, and the second electrode of the sensing capacitor C1 is connected to the ground potential.

FIG. 39 is a timing chart for explaining an operation of a source follower type optical sensor according to an embodiment of the present invention.

In Fig. 39, RL Reset is a signal that periodically resets the potential of the lead-out line RL. The potential of the lead-out line RL can be reset when the RL Reset signal is at a high level.

SCANn is a signal applied to the first scan line SLn and SCANn + 1 is a signal applied to the second scan line SLn. When the signals SCANn and SCANn + 1 supplied to the scan lines SLn and SLn + 1 are at the low level, the corresponding photosensor SN is selected. For example, when a signal applied to the first scan line SLn is switched to a low level (when a selection signal is applied), a drain electrode is connected to the lead-out line RL and the first scan line SLn, An optical sensor SN including the N-type transistor T1 to which the source electrode is connected is selected and the sensing value from the optical sensor SN is output to the lead-out line RL. The period from when the signals SCANn and SCANn + 1 supplied to the scan lines SLn and SLn + 1 are switched from the high level to the low level and then again becomes the low level can be regarded as one frame.

V1 represents the first electrode potential V1 of the sensing capacitor C1 and R1 represents the potential R1 of the lead-out line RL. In the timing chart of V1 and R1, a solid line is a state when light reflected by an external object is supplied to the optical sensor SN (Light), and a broken line is a state when light is not supplied (Dark).

Hereinafter, the operation of the optical sensor SN will be described with reference to Figs. 38 and 39. Fig.

Since no selection signal is applied to the first scan line SLn and the second scan line SLn + 1 during the T1 period, the current flows through the N-type transistor N and the second current flows from the P- No current flows to the scan line SLn + 1.

The T1 period may be a period after a low level signal is applied to the second scan line SLn + 1 and a low level signal is applied to the second scan line SLn. That is, the T1 period is a period after T4 when the low level signal is applied to the second scan line SLn + 1. When a low level signal is applied to the second scan line SLn + 1 in the period T4, the charges charged in the sensing capacitor C1 are discharged through the P-type transistor PT1 serving as a photodiode, (C1) is reset. Therefore, the first electrode potential V1 of the sensing capacitor C1 becomes 0 V in the period T4.

Since no selection signal is applied to the first scan line SLn and the second scan line SLn + 1 during the T1 period, if a leakage current is generated in the P-type transistor PT1 serving as a photodiode, the corresponding leakage current So that the sensing capacitors C1 are charged.

If light reflected from the outside is not supplied, leakage current is not formed in the P-type transistor PT1. Therefore, no charge is stored in the sensing capacitor C1 connected to the drain electrode of the P-type transistor PT1 , The first electrode potential V1 of the sensing capacitor C1 is maintained at a low level (Dark).

On the other hand, when light reflected from the outside is supplied during the T1 period, a leakage current is formed in the P-type transistor PT1 as described above. This leakage current charges the sensing capacitor C1 and the charging is continued until the low level signal is applied to the second scan line SLn + 1, that is, during one frame. Accordingly, the first electrode potential V1 of the sensing capacitor C1 gradually increases (Light).

At this time, when the signal SCANn supplied to the first scan line SLn is switched from the high level to the low level (T2 period), the source electrode potential of the N-type transistor T1 becomes lower than the drain electrode potential.

If the light reflected from the outside is not supplied, charge is not charged in the sensing capacitor C1 in the T1 section and the gate electrode potential of the N-type transistor T1 is less than the threshold voltage, Will not turn on. Therefore, a minute current flows or no current flows through the N-type transistor T1 and the potential R1 of the lead-out line RL is kept equal to the T1 period or can be lowered to a certain degree with a fine current flow (Dark).

However, when light reflected from the outside is supplied, since the gate electrode potential V1 of the N-type transistor T1 will exceed the threshold voltage, a current flows from the drain electrode of the N-type transistor T1 to the source electrode . That is, a current flows from the lead-out line RL to the first scan line SLn. The magnitude of the current flowing is proportional to the gate electrode potential of the N-type transistor T1, that is, the magnitude of the first electrode potential V1 of the sensing capacitor C1. The larger the intensity of the light reflected from the outside is, the larger the leakage current formed by the P-type transistor PT1 becomes. Accordingly, the first electrode potential V1 of the sensing capacitor C1 becomes larger, The width of the potential R1 of the lead-out line RL lowered by the current flowing through the transistor T1 becomes proportional to the intensity of the supplied light. That is, as the intensity of the light reflected from the outside increases, the potential R1 of the lead-out line RL is greatly reduced in the period T2. The potential R1 of the lead-out line RL is transferred to the IC chip separately when the low level signal is applied to the first scan line SLn. The contact state and the contact state can be determined.

Since the optical sensor is provided for each pixel of the display device, it is possible to check the contact state and the contact state of each pixel, and when not only the touch by the touch generating means and the touch generation point but also the user finger touches, It is possible to recognize the fingerprint by judging whether or not the ridge or valley of the fingerprint has been touched.

The reset signal RL Reset for resetting the potential R1 of the lead-out line RL is applied after the T2 period so that the potential R1 of the lead-out line RL is applied to the first scan line SLn ) Is initialized to the same level as before the low level signal is applied.

When the signal SCANn + 1 supplied to the second scan line SLn + 1 is lowered from the high level to the low level (T4 section) after the lead-out line RL potential R1 is reset, All of the charges stored in the sensing capacitor C1 are discharged to the second scan line SLn + 1 through the P-type transistor PT1, whereby the first electrode potential V1 of the sensing capacitor C1 is initialized. When the low level signal is applied to the second scan line SLn + 1, the operations of T1, T2, and T3 are repeated again.

In the optical sensor of the general source follower type described with reference to FIG. 37, when the photodiode PD is made equal to the transistor and compared with the source follower type optical sensor of the present invention described with reference to FIG. 38, It can be seen that the two transistors are reduced. Accordingly, the optical sensor SN is formed on the substrate having the display area. As the elements constituting the optical sensor SN are reduced for the above reason, the aperture ratio in the entire display panel can be improved.

40 is a plan view showing a layout of a circuit structure of a source follower type optical sensor according to an embodiment of the present invention. FIG. 40A shows the structure of a general optical sensor described with reference to FIG. 37, and FIG. 40B shows the structure of the optical sensor according to the present invention described with reference to FIG.

Referring to Figure 40 (a), a typical source-follower type optical sensor requires four transistors and one capacitor. Referring to Figure 40 (b), the source follower type optical The sensor requires only two transistors and one capacitor.

Therefore, according to the embodiment of the present invention, the area of the circuit configuration can be reduced (about 27% reduction) compared with a general source follower type optical sensor, and when the optical sensor is integrated in the display device, .

In addition, the advantage of the source follower method that can obtain a large detection signal without an amplifier can be taken as it is.

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

The scope of the present invention is defined by the appended claims, and all changes or modifications derived from the meaning and scope of the claims and their equivalents should be construed as being included within the scope of the present invention.

1: Display device 10: Cell array
20: gate driver 30: source driver
40: AFE (analog front end) 50: signal processor
60: control logic 100: unit pixel
101, 102: optical amplification cover part 110: cover window
120, 160, and 163: Transparent optical amplification layer 210:
220: Pixel TFT array layer 223: Pixel driving TFT
230: liquid crystal layer 243: light sensor
250: upper substrate 300: backlight unit
SID: Sensor integrated display panel SN: Light sensor
SL: scan line RL: lead out line
Vdd: Power input

Claims (25)

An optical amplification cover part having a transparent optical amplification layer for amplifying a light pattern due to a fingerprint of a user touching the display surface, and a cover window for strength enhancement;
A thin film transistor (TFT) array for driving a plurality of pixels constituting an image; And
And an optical sensor array disposed between the optical amplification cover section and the thin film transistor array for sensing a light pattern amplified by the optical amplifier cover section,
An image scanable display device. The method according to claim 1,
Wherein the transparent optical amplification layer includes a plurality of quantum dots that absorb light in a first wavelength range and emit light in a second wavelength range different from the first wavelength range. 3. The method of claim 2,
Wherein the first wavelength region belongs to a visible light region and the second wavelength region belongs to an infrared region. The method according to claim 1,
Wherein the transparent optical amplification layer comprises a polarization conversion layer and wherein the polarization conversion layer comprises a plurality of quantum dots that absorb a first polarization and emit a second polarization that is substantially perpendicular to the first polarization and its polarization axis, Scanable display device. The method according to claim 1,
The optical amplification cover unit
A cover window whose one side constitutes the display surface; And
And a transparent optical amplification layer formed opposite the display surface of the cover window. The method according to claim 1,
The optical amplification cover unit
Cover window;
A transparent optical amplification layer formed on an upper surface of the cover window; And
And a protective layer formed on an upper surface of the transparent optical amplification layer, the surface of which forms the display surface,
Wherein the photosensor array is formed on a bottom surface of the cover window. The method according to claim 1,
Wherein the thin film transistor (TFT) array and the optical sensor array are arranged to overlap one another in a planar manner to form a part of one sensor integrated display panel. 8. The method of claim 7,
The sensor integrated display panel is a liquid crystal display panel,
A lower substrate part having a thin film transistor (TFT) array for driving the plurality of pixels formed in a lower substrate; And
And an upper substrate portion formed inside the upper substrate with a black matrix formed corresponding to the non-transparent portion of the thin film transistor (TFT) array so as to shield visible light and an optical sensor array arranged to be superimposed on the black matrix, . 9. The method of claim 8,
Wherein the black matrix is formed of an infrared filter resin that blocks visible light but transmits infrared light,
Wherein the photosensor array comprises a plurality of infrared sensors. 10. The method of claim 9,
Wherein the plurality of infrared sensors are disposed at positions where the thin film transistor (TFT) array overlaps the thin film transistor unit driving the pixel electrodes in a planar manner, respectively. 9. The method of claim 8,
Wherein the photosensor array comprises a metal wiring and an optical sensor disposed inside the black matrix. 12. The method of claim 11,
Wherein the upper substrate portion further comprises an optical waveguide formed in a portion of the black matrix corresponding to the optical sensor. 12. The method of claim 11,
Wherein the upper substrate portion further comprises at least one microlens formed in a portion corresponding to the photosensor. 9. The method of claim 8,
Wherein the photosensor array comprises wiring and an optical sensor disposed between the top substrate and the black matrix. 15. The method of claim 14,
Wherein the wiring is a transparent electrode wiring or a metal wiring having an antireflection layer formed on a surface in contact with the upper substrate. The method according to claim 1,
The optical amplification cover unit
Wherein the infrared light incident on the transparent optical amplification layer to satisfy the internal total reflection condition is scattered by the fingerprint touched to the display surface and emitted to the optical sensor array side. A lower substrate part having a thin film transistor (TFT) array for driving the plurality of pixels formed in a lower substrate;
An upper substrate portion formed on the inner side of the upper substrate to correspond to the non-transparent portion of the thin film transistor (TFT) array and having a black matrix for shielding visible light and an optical sensor array arranged to overlap the black matrix; And
And a liquid crystal layer disposed between the lower substrate portion and the upper substrate portion,
An image scanable display device. 18. The method of claim 17,
Wherein the black matrix is formed of an infrared filter resin that blocks visible light but transmits infrared light,
Wherein the photosensor array comprises a plurality of infrared sensors. 19. The method of claim 18,
Wherein the plurality of infrared sensors are disposed at positions where the thin film transistor (TFT) array overlaps the thin film transistor unit driving the pixel electrodes in a planar manner, respectively. 18. The method of claim 17,
Wherein the photosensor array comprises a metal wiring and an optical sensor disposed inside the black matrix. 21. The method of claim 20,
Wherein the upper substrate portion further comprises an optical waveguide formed in a portion of the black matrix corresponding to the optical sensor. 21. The method of claim 20,
Wherein the upper substrate portion further comprises at least one microlens formed in a portion corresponding to the photosensor. 18. The method of claim 17,
Wherein the photosensor array comprises wiring and an optical sensor disposed between the top substrate and the black matrix. 24. The method of claim 23,
Wherein the wiring is a transparent electrode wiring or a metal wiring having an antireflection layer formed on a surface in contact with the upper substrate. An optical amplification cover part for amplifying a light pattern due to a fingerprint of a user contacting the display surface, the optical amplification cover part having a surface forming a display surface;
A display panel having a thin film transistor (TFT) array for driving a plurality of pixels constituting an image; And
And an optical sensor array disposed between the optical amplification cover unit and the thin film transistor (TFT) array, for sensing a light pattern amplified by the optical amplification cover unit,
Wherein the optical sensor array is integrally formed with the optical amplification cover part, and is arranged to overlap with the black matrix of the display panel in a planar manner,
An image scanable display device.

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