WO2019041991A1

WO2019041991A1 - A sensing substrate and sensing panel, display panel and display device

Info

Publication number: WO2019041991A1
Application number: PCT/CN2018/092817
Authority: WO
Inventors: 刘英明; 董学; 王海生; 吴俊纬; 丁小梁; 许睿; 刘伟
Original assignee: 京东方科技集团股份有限公司
Priority date: 2017-09-04
Filing date: 2018-06-26
Publication date: 2019-03-07
Also published as: CN107422560A

Abstract

The present invention provides a sensing substrate, and a display panel and a display device thereof. The sensing substrate comprises a substrate. A thin-film transistor and a photosensitive device layer are provided on the substrate, wherein the photosensitive device layer comprises a light-shielding portion. An orthographic projection of the light-shielding portion onto the substrate overlaps with at least a portion of an orthographic projection of an active layer of the thin-film transistor onto the substrate, and the light-shielding portion is disposed on the active layer of the thin-film transistor away from one side of a gate of the thin-film transistor.

Description

Sensing substrate and sensing board, display panel and display device

Cross-reference to related applications

The present application claims priority to Chinese Patent Application No. 20171078647, filed on Sep. 4, s.

Technical field

The present disclosure relates to the field of touch technologies, and in particular, to a sensing substrate and a sensing board, a display panel, and a display device.

Background technique

Thin Film Transistor Liquid Crystal Display (TFT-LCD) has the characteristics of small size, low power consumption, no radiation, and has a dominant position in the current flat panel display market. For TFT-LCDs, the sensing substrate and manufacturing process determine its product performance, yield and price.

Summary of the invention

Embodiments of the present disclosure provide a sensing substrate and a sensing panel, a display panel, and a display device.

Embodiments of the present disclosure provide a sensing substrate. The sensing substrate includes: a substrate substrate; a thin film transistor and a photosensor layer on the substrate, the photosensor layer includes a light shielding portion, and an orthographic projection of the light shielding portion on the substrate substrate The orthographic projection of the active layer of the thin film transistor on the base substrate at least partially overlaps, and the light shielding portion is located on a side of the thin film transistor from which the active layer faces away from the gate of the thin film transistor.

In some embodiments, the photosensor layer further includes a fingerprint recognition portion, an orthographic projection of the fingerprint recognition portion on the substrate substrate does not overlap with an orthographic projection of the active layer on the substrate substrate The fingerprint recognition portion is electrically connected to the first pole or the second pole of the thin film transistor.

In some embodiments, the gate is located between the base substrate and the active layer, the fingerprint recognition portion is disposed in the same layer as the light shielding portion, and the fingerprint recognition portion and the light shielding portion are Intersected from each other.

In some embodiments, the light shielding portion functions as a touch sensing portion. The sensing substrate further includes a touch detection signal line disposed in the same layer as the gate, and the touch detection signal line is electrically connected to the corresponding light shielding portion.

In some embodiments, the touch detection signal lines are in one-to-one correspondence with the light shielding portions, or each of the touch detection signal lines corresponds to the plurality of the light shielding portions.

In some embodiments, the sensing substrate further includes at least one reference signal line disposed in the same layer as the gate. The at least one reference signal line is electrically coupled to at least one of the light shielding portion and the fingerprint recognition portion to provide a corresponding bias voltage.

In some embodiments, the bias voltage is provided to the light shielding portion and the fingerprint recognition portion through the same reference signal line.

In some embodiments, the sensing substrate further includes: a gate insulating layer between the active layer and the gate; a first between the active layer and the photosensor layer An insulating layer; and a second insulating layer on a side of the photosensor layer facing away from the gate.

In some embodiments, the sensing substrate further includes: a first conductive portion and a second conductive portion disposed in the same layer as the first or second pole of the thin film transistor; The second insulating layer faces away from the third conductive portion and the fourth conductive portion disposed on the same side of the substrate substrate. The at least one reference signal line is electrically connected to at least one of the light shielding portion and the fingerprint recognition portion through the first conductive portion and the third conductive portion. The touch detection signal line is electrically connected to the light shielding portion through the second conduction portion and the fourth conduction portion.

In some embodiments, the sensing substrate further includes a protective layer on a side of the photosensor layer facing away from the substrate substrate.

In some embodiments, the gate is located on a side of the active layer away from the substrate substrate.

In some embodiments, the sensing substrate further includes a protective layer on a side of the fingerprint identifying portion facing away from the substrate substrate.

In some embodiments, the material of the photosensor layer comprises a PIN-type semiconductor material.

Embodiments of the present disclosure also provide a sensing board including the sensing substrate as described in the above embodiments.

Embodiments of the present disclosure also provide a display panel. The display panel includes the sensing substrate as described in the above embodiments.

Embodiments of the present disclosure also provide a display device. The display device includes a display panel as described above.

Further aspects and scope of the adaptation will become apparent from the description provided herein. It should be understood that various aspects of the present application can be implemented alone or in combination with one or more other aspects. It should be understood that the description and specific examples are not intended to limit the scope of the application.

DRAWINGS

The drawings described herein are for purposes of illustration only, and are not intended to

1 is a schematic cross-sectional view of a sensing substrate in accordance with an embodiment of the present disclosure;

2 is a schematic cross-sectional view of a sensing substrate in accordance with an embodiment of the present disclosure;

3 is a schematic cross-sectional structural view of a sensing substrate in accordance with an embodiment of the present disclosure;

4 is a schematic cross-sectional structural view of a sensing substrate in accordance with an embodiment of the present disclosure;

5a and 5b are schematic diagrams of a planar structure of a sensing substrate according to an embodiment of the present disclosure;

6 is a flow chart of a method of sensing a substrate for fingerprinting using an embodiment in accordance with the present disclosure.

Throughout the various views of the drawings, corresponding reference numerals indicate corresponding parts or features.

Detailed ways

The singular forms of the terms used in the claims and the appended claims are inclusive, and vice versa, unless the context clearly indicates otherwise. Thus, when reference is made to the singular, the <RTIgt; Similarly, the words "comprising" and "comprising" are to be construed as inclusive rather than exclusive. Likewise, the terms "include" and "or" are intended to be construed as being Where the term "example" is used herein, particularly when it is placed after a group of terms, the "example" is merely exemplary and illustrative and should not be considered to be exclusive or broad. .

In addition, it should be noted that the articles "a", "an", "the", "the" It has been stated that the meaning of "a plurality" is two or more; the terms "comprising", "including", "including" and "having" are intended to be inclusive and mean that there may be additional The terms "first", "second", "third", etc. are used for the purpose of description only and are not to be construed as indicating or implying the relative importance and order of formation.

The flowchart depicted in this disclosure is merely an example. Many variations of the flowchart or the steps described therein may exist without departing from the spirit of the present disclosure. For example, the steps may be performed in a different order, or steps may be added, deleted, or modified. These variations are considered to be part of the claimed aspect.

In order to prevent the external light or the light of the backlight from being irradiated to the channel region of the thin film transistor to generate photo-generated carriers, thereby affecting the performance of the thin film transistor, a light-shielding layer for preventing light from being irradiated to the channel region is also provided. The pattern of the light shielding layer generally coincides with the pattern of the channel region. However, in the related art, a light shielding layer is usually formed using a metal material. However, although the metal light-shielding layer has a good light-shielding effect, the metal light-shielding layer has a relatively high light-reflecting property and reflects a large amount of external light. When the reflected external light is emitted from the light emitting side of the display device, the display effect of the display device is affected.

Embodiments of the present disclosure provide a sensing substrate and a sensing plate, a display panel, and a display device to at least partially overcome the problems in the related art.

The specific embodiments of the sensing substrate and the sensing board, the display panel and the display device provided by the embodiments of the present disclosure will be described in detail below with reference to the accompanying drawings. The thickness and shape of each film layer in the drawings do not reflect true proportions, and are merely intended to schematically illustrate the disclosure.

1 is a schematic cross-sectional view of a sensing substrate in accordance with an embodiment of the present disclosure. As shown in FIG. 1, an embodiment of the present disclosure provides a sensing substrate. The sensing substrate includes: a substrate substrate 10; a thin film transistor 11 and a photosensor layer 12 on the substrate substrate 10. As an example, a plurality of thin film transistors are arranged, for example, in an array. The photosensor layer 12 includes a light blocking portion 121. The orthographic projection of the light shielding portion 121 on the base substrate 10 at least partially overlaps with the orthographic projection of the active layer 111 of the thin film transistor 11 on the base substrate 10, and the light shielding portion 121 is located away from the active layer 111 of the thin film transistor 11 One side of the gate 112 of the transistor 11.

In an embodiment of the present disclosure, the light shielding portion in the photosensitive device layer is used to block the pattern of the active layer. Since the photosensitive device layer is exposed to light to generate a photocurrent, that is, the photosensitive device layer can convert the light energy into electrical energy, the photosensitive device layer has a certain light absorbing effect, and most of the light is absorbed by the photosensitive device layer, thereby reducing the light shielding portion. The reflection makes it not affect the display effect of the display device when applied to the display panel.

In some embodiments, the orthographic projection of the light shielding portion 121 on the base substrate 10 completely overlaps with the orthographic projection of the active layer 111 on the base substrate 10, thereby being able to better block the light entering the active layer 111. Thereby, the active layer 111 is protected to improve the performance of the thin film transistor.

In some embodiments, referring to FIG. 1, the photosensor layer 12 can also include a fingerprint recognition portion 122. The orthographic projection of the fingerprint recognition portion 122 on the base substrate 10 does not overlap with the orthographic projection of the active layer 111 on the base substrate 10. The fingerprint recognition unit 122 is electrically connected to one of the first pole and the second pole of the thin film transistor 11.

In some embodiments, as shown in FIG. 1, the gate 112 is between the substrate substrate 10 and the active layer 111. It should be noted that, according to an embodiment of the present disclosure, the gate electrode 112 may be located on a side of the active layer 111 away from the substrate substrate 10 (described later). That is, the thin film transistor 11 may be a bottom gate type thin film transistor or a top gate type thin film transistor. Here, the case where the thin film transistor 11 is a bottom gate type thin film transistor will be described in detail first.

In some embodiments, the fingerprint recognition unit 122 is disposed in the same layer as the light shielding portion 121, and the fingerprint recognition portion 122 and the light shielding portion 121 are spaced apart from each other. Here, "same layer setting" refers to formation using the same film layer. That is, the fingerprint recognition unit 122 and the light shielding unit 121 are formed by one patterning process, that is, the light shielding unit 121 and the fingerprint recognition unit 122 are located in the same layer and have the same material. Thereby, the manufacturing process of the sensing substrate is simplified, and the cost is saved.

In some embodiments, the fingerprint recognition unit 122 is also multiplexed as a touch electrode to implement touch detection. That is, the fingerprint recognition unit 122 can implement touch detection and fingerprint recognition by means of time-division driving.

In an embodiment of the present disclosure, the photosensitive device of photosensor layer 12 is typically comprised of a photosensitive semiconductor material. Since the photosensor layer 12 is exposed to light to generate a photocurrent, that is, the photosensor layer 12 can convert the light energy into electric energy, the photosensor layer 12 has a certain light absorbing effect. Thus, the photosensitive device layer 12 can be used as the light shielding portion by utilizing the light absorbing characteristics of the photosensor layer 12. In addition, it is also possible to determine the position of the valley and the ridge of the finger by using different light intensity of the valley and the ridge reflected by the finger to cause the photocurrent layer 12 to have different photocurrents, that is, to realize the function of fingerprint recognition by using the photosensor layer 12. . Therefore, the light shielding portion 121 and the fingerprint recognition portion 122 can be disposed to be in the same layer and have the same material. Thus, the light shielding portion 121 and the fingerprint recognition portion 122 can be formed by one patterning process without separately forming the light shielding portion 121, thereby simplifying the manufacturing process.

In some embodiments, in order to avoid the influence of the photocurrent in the light shielding portion 121 on the fingerprint recognition, the light shielding portion 121 and the fingerprint recognition portion 122 are insulated.

It should be noted that, in the embodiment of the present disclosure, one of the first pole and the second pole of the thin film transistor 11 is a signal input terminal, and the other is a signal output terminal. Here, one of the first pole and the second pole of the thin film transistor 11 is a source, and the other is a drain, that is, when the first pole 113 is a source, the second pole 114 is a drain; or When one pole 113 is a drain, the second pole 114 is a source. The fingerprint recognition unit 122 is electrically connected to one of the first pole and the second pole of the thin film transistor 11, and thus can read the current output from the other of the first pole and the second pole of the thin film transistor 11 To achieve fingerprint recognition detection.

In some embodiments, as shown in FIG. 2, the light shielding portion 121 can serve as a touch sensing portion. The sensing substrate may further include a touch detection signal line 19 disposed in the same layer as the gate 112 of the thin film transistor 11. The touch detection signal line 19 is electrically connected to the corresponding light blocking portion 121.

In some embodiments, according to the arrangement of the thin film transistors on the sensing substrate, a plurality of touch detection signal lines may be correspondingly disposed. The touch detection signal line 19 is disposed on the same layer as the gate 112. On the one hand, the touch detection signal line 19 can be fabricated by using the same patterning process as the gate 112, thereby simplifying the manufacturing process, and on the other hand, reading each touch The current of the detection signal line 19 is controlled to determine the touch position. If the current of the touch detection signal line 19 at a certain position changes, the position where the corresponding light shielding portion 121 is located is touched. Therefore, in the sensing substrate shown in FIG. 2, the fingerprint recognition function is implemented by the fingerprint recognition unit 122, and the touch detection function is realized by the light shielding unit 121. Here, the fingerprint recognition and the touch detection can be independent of each other without multiplexing the fingerprint recognition unit 122 into the touch electrodes, whereby the driving timing can be simplified.

Here, the principle that the touch detection signal line 19 is electrically connected to the corresponding light shielding portion 121 to realize the touch display is specifically: when the position where the light shielding portion 121 is touched, the light intensity reflected by the finger changes the light shielding portion 121. The photocurrent, therefore, the touch change can be detected by the touch detection signal line 19 to determine the touch position.

In some embodiments, the touch detection signal line 19 may be in one-to-one correspondence with the light shielding portion 121.

In some embodiments, each of the touch detection signal lines 19 may correspond to the plurality of light shielding portions 121.

When the finger touches the display screen, the finger and the touch screen have a certain contact area, and the contact area generally corresponds to a plurality of pixels. Therefore, when the detection accuracy is satisfied, a plurality of pixels within a certain range can be set to share the same touch detection signal. Line 19. Thereby, the number of the touch detection signal lines 19 can be reduced while satisfying the detection accuracy. For example, the light shielding portion 121 of each pixel in the range of 5 × 5 mm can be connected to the same touch detection signal line 19. In addition, when the required detection accuracy is high, the touch detection signal line 19 may be disposed in one-to-one correspondence with the light shielding portion 121.

In some embodiments, referring to FIG. 2, the sensing substrate may further include at least one reference signal line 13 disposed in the same layer as the gate 112 of the thin film transistor 11. The at least one reference signal line 13 is electrically connected to at least one of the light shielding portion 121 and the fingerprint recognition portion 122 to provide a corresponding bias voltage.

In some embodiments, a plurality of reference signal lines 13 may be disposed correspondingly according to the arrangement of the thin film transistors on the sensing substrate. Since the photosensitive device of the photosensor layer 12 is generally composed of a photosensitive semiconductor material, and the PN junction or PIN junction formed by the photosensitive semiconductor material has unidirectional conductivity as a photosensitive device, touch detection and/or use is performed using the light shielding portion 121. When the fingerprint recognition unit 122 performs fingerprint detection, the corresponding bias voltage can be supplied to the light shielding portion 121 and/or the fingerprint recognition portion 122 through at least one reference signal line 13.

On the one hand, in the process of detecting the fingerprint, it is necessary to apply a reverse voltage to the fingerprint recognition unit 122 so that the PN junction or the PIN junction in the fingerprint recognition unit 122 is in a reverse bias state. In the absence of illumination, the fingerprint recognition portion 122 has a small reverse current. When the fingerprint recognition portion 122 is irradiated with light, the PN junction or the PIN junction in the fingerprint recognition portion 122 generates electron-hole pairs, increasing the density of minority carriers. These carriers drift under the reverse voltage, causing the reverse current to increase greatly, forming a photocurrent, and the magnitude of the photocurrent is determined by the intensity of the light.

When P of the fingerprint recognition unit 122 is extremely low and N is extremely high, the fingerprint recognition unit 122 is in a reverse bias state. Since the fingerprint recognition portion 122 is electrically connected to one of the first pole and the second pole of the thin film transistor 11 and is electrically connected to the corresponding reference signal line 13, it is possible to pass the first pole and the first to the thin film transistor 11, respectively. One of the two poles and the reference signal line 13 apply different voltages, so that the fingerprint recognition unit 122 is in a reverse bias state. One end of the fingerprint recognition portion 122 connected to one of the first pole and the second pole of the thin film transistor 11 is an N pole, and one end connected to the reference signal line 13 is a P example, and -1 V can be applied to the reference signal line 13. The voltage is applied to a voltage of +3 V to one of the first pole and the second pole of the thin film transistor 11. This is only an example and does not limit the magnitude of the applied voltage.

On the other hand, when the touch detection is performed by the light shielding portion 121, the touch position can be determined only by detecting a change in the current at a certain position. Therefore, during the detection process, the light shielding portion 121 can be in a forward bias state. It can also be in a reverse biased state. Due to the reference signal line 13 electrically connected to the corresponding light shielding portion 121, a certain voltage can be applied to the light shielding portion 121 through the reference signal line 13 and the touch detection signal line 19, so that the light shielding portion 121 is in a forward bias state or a reverse bias state. Further, it is not necessary to apply a voltage to the light shielding portion 121. Since the light reflected by the finger touch causes the light blocking portion 121 to form a photocurrent, the current of the light shielding portion 121 can be directly read by the touch detection signal line 19, thereby detecting the touch position. This type of detection is relatively simple. However, applying a voltage to the light shielding portion 121 to cause the light shielding portion 121 to be in a forward bias state or a reverse bias state makes the detected current change more conspicuous, and it is easier to detect the touch position.

Further, by arranging at least one reference signal line 13 in the same layer as the gate electrode 112 of the thin film transistor 11, at least one pattern of the reference signal line 13 and the gate electrode 112 can be formed by one patterning process during fabrication, thereby simplifying the manufacturing process.

As an example, as shown in FIG. 3, a bias voltage may be supplied to the light shielding portion 121 and the fingerprint recognition portion 122 through the same reference signal line 13.

For example, during the detection, a certain voltage may be applied to the reference signal line 13 to maintain the position of the reference signal line 13 at a certain potential. In this way, the fingerprint recognition unit 122 can be kept in the reverse bias state by a certain voltage applied to one of the first pole and the second pole of the thin film transistor, and a certain voltage is applied to the touch detection signal line 19 to make the light shielding portion. 121 maintains a forward biased state or a reverse biased state. For example, a voltage of -2 V is applied to the reference signal line 13, and a voltage of +1 V is applied to one of the first pole and the second pole of the thin film transistor 11, so that the fingerprint recognition portion 122 is in a reverse bias state. In addition, a voltage of +2 V may be applied to the touch detection signal line 19 to cause the light shielding portion 121 to be in a reverse bias state, or a voltage of -5 V may be applied to the touch detection signal line 19 to cause the light shielding portion 121 to be in a forward bias state. Thereby, the touch detection and the fingerprint identification detection common reference signal line can be realized without affecting the detection result.

In some embodiments, as shown in FIGS. 2 and 3, the sensing substrate may further include: a gate insulating layer 14 between the active layer 111 and the gate 112; and the active layer 111 and the photosensor layer 12 a first insulating layer 15; and a second insulating layer 16 on the side of the photosensor layer 12 facing away from the gate 112.

The above-described gate insulating layer 14 can function to isolate the active layer 111 and the gate electrode 112. The first insulating layer 15 described above can function to isolate the active layer 111 and the light shielding portion 121. The second insulating layer 16 described above can function as a flattening.

In some embodiments, in order to realize the electrical connection between the fingerprint recognition unit 122 and the corresponding reference signal line 13 and to achieve electrical connection between the light shielding portion 121 and the corresponding touch detection signal line 19, referring to FIG. 2, according to the present disclosure The sensing substrate of the embodiment may further include: a first conductive portion 131 and a second conductive portion 191 disposed in the same layer as one of the first and second poles of the thin film transistor 11; and the second insulation The layer 16 faces away from the third conductive portion 132 and the fourth conductive portion 192 which are disposed in the same layer on the side of the base substrate 10. The reference signal line 13 is electrically connected to the fingerprint recognition unit 122 through the first conduction portion 131 and the third conduction portion 132. The touch detection signal line 19 is electrically connected to the light shielding portion 121 through the second conduction portion 191 and the fourth conduction portion 192.

In some embodiments, referring to FIG. 3, the reference signal line 13 is electrically connected to the fingerprint recognition portion 122 and the light shielding portion 121 through the first conductive portion 131 and the third conductive portion 132.

Referring to FIGS. 2 and 3, the first conductive portion 131 and the second conductive portion 191 are disposed in the same layer as the source/drain electrodes 113 of the thin film transistor 11, so that the source/drain electrodes 113 of the thin film transistor 11 can be formed by one patterning process, The first conductive portion 131 and the second conductive portion 191. In order to electrically connect the first conductive portion 131 to the reference signal line 13, it is necessary to make a via hole at a position corresponding to the reference signal line 13 in the gate insulating layer 14 before forming the pattern of the first conductive portion 131. It can be achieved by an etching process. Similarly, in order to electrically connect the second conductive portion 191 to the touch detection signal line 19, it is necessary to correspond to the touch detection signal line 19 in the gate insulating layer 14 before forming the pattern of the second conductive portion 191. Make a hole at the location. The via hole may be formed simultaneously with the via hole at the corresponding position of the reference signal line 13 by the same etching process.

Since the third conductive portion 132 is disposed in the same layer as the fourth conductive portion 192, the third conductive portion 132 and the fourth conductive portion 192 can be formed by one patterning process. Since the fingerprint recognition unit 122 realizes fingerprint recognition by using different light intensities reflected by the valleys and ridges of the finger, the light shielding portion 121 also generates a photocurrent by the light reflected by the finger to detect the touch position, and therefore, in order to avoid the third guide The through portion 132 blocks the fingerprint recognition portion 122 and prevents the fourth conductive portion 192 from blocking the light shielding portion 121. The third conductive portion 132 and the fourth conductive portion 192 are preferably made of a transparent conductive material, for example, indium tin oxide ( Indium tin oxide, ITO) and other materials.

As shown in FIGS. 2 and 3, in order to realize electrical connection between the fingerprint recognition unit 122 and the first conductive portion 131, the electrical connection between the fingerprint recognition portion 122 and the first reference signal line 13 is realized, and a third is formed. Before the pattern of the conductive portion 132, a via hole is formed at a position corresponding to the first conductive portion 131 in the first insulating layer 15 and the second insulating layer 16. Similarly, in order to realize the electrical connection between the light shielding portion 121 and the second conductive portion 191, the electrical connection between the light shielding portion 121 and the touch detection signal line 19 is further realized, before the pattern of the fourth conduction portion 192 is formed. A via hole is formed at a position corresponding to the second conductive portion 191 in the first insulating layer 15 and the second insulating layer 16. During the fabrication process, the vias at the locations of the first insulating layer 15 and the second insulating layer 16 corresponding to the first conductive portion 131 and the second conductive portion 191 may be simultaneously formed by the same etching process.

In some embodiments, a third insulating layer 17 is further disposed on a side of the third conductive portion 132 and the fourth conductive portion 192 away from the base substrate 10. The third insulating layer 17 can protect the third conductive portion 132 and the fourth conductive portion 192 and function as a flattening.

During the fabrication process, an etch process is required during the fabrication of the photosensor layer and during the fabrication of vias in the second insulating layer 16. In order to avoid damage to the surface of the photosensor layer 12 by the etching solution used in the etching process, as shown in FIG. 1 , FIG. 2 and FIG. 3 , the sensing substrate according to an embodiment of the present disclosure may further include a photosensor. The layer 12 faces away from the protective layer 18 on the side of the base substrate 10. As an example, the pattern of the protective layer 18 can conform to the pattern of the photosensor layer 12.

Optionally, in order to prevent the protection layer 18 from affecting the detection accuracy of the fingerprint recognition portion 122 and the detection accuracy of the light shielding portion 121 detecting the touch position, the protective layer 18 may be made of a transparent conductive material, for example, indium tin oxide (Indium). Tin oxide, ITO) and other materials.

Referring to FIG. 1, FIG. 1 is exemplified by taking the thin film transistor 11 on the sensing substrate as a bottom gate type. The light shielding portion 121 is disposed such that the orthographic projection on the base substrate 10 overlaps with the orthographic projection of the active layer 111 on the base substrate 10, and the light shielding portion 121 is located at a side of the active layer 111 of the thin film transistor 11 facing away from the gate electrode 112. On the side, the channel region of the thin film transistor 11 can be effectively blocked to prevent external light from affecting the switching characteristics of the thin film transistor 11.

Referring to FIG. 4, an embodiment of the present disclosure provides a sensing substrate including a top gate type thin film transistor 11. The gate 112 of the top gate thin film transistor 11 is located on the side of the active layer 111 facing away from the base substrate 10, and the light blocking portion 121 is also disposed on the side of the active layer 111 facing away from the gate 112. For the top gate thin film transistor 11, the light shielding portion 121 can block the light of the backlight and prevent the light of the backlight from being irradiated onto the active layer 111, thereby affecting the switching characteristics of the thin film transistor 11. It should be noted that other structures in the sensing substrate are similar to the sensing substrate using the bottom gate thin film transistor described above, and details are not described herein again.

In some embodiments, in the case where the thin film transistor 11 is a top gate type thin film transistor, as shown in FIG. 4, the sensing substrate may further include a protective layer 18 on a side of the fingerprint identifying portion 122 facing away from the base substrate 10.

In some embodiments, the material of the photosensor layer 12 can comprise a PIN-type semiconductor material. The PIN-type semiconductor material can be made of amorphous silicon or polycrystalline silicon material.

In an embodiment of the present disclosure, the P and N poles of the photosensor layer 12 can be set according to actual needs. For example, one side of the photosensor layer 12 close to the base substrate 10 may be set to an N pole, and a side away from the base substrate 10 may be set as a P pole. This is merely an example, and the specific implementation of the photosensor layer is not limited.

5a and 5b are schematic diagrams of a planar structure of a sensing substrate in accordance with an embodiment of the present disclosure. The principle of fingerprint recognition in the embodiments of the present disclosure will be described below with reference to FIGS. 5a and 5b.

Referring to FIGS. 5a and 5b, the gate electrode 112 of the plurality of thin film transistors 11 is connected to the gate driving circuit 22 through the gate line 21. The output terminal 114 of the plurality of thin film transistors 11 is connected to the data signal receiving circuit through the data line 23. When the fingerprint detection is performed, the gate driving circuit 22 controls the gate electrode 112 to open the thin film transistor 11 row by row; the data signal processing circuit 24 first inputs a certain voltage to the fingerprint recognition portion 122, so that the fingerprint recognition portion 122 is in a reverse bias state, and The magnitude of the current of each data line 23 is detected; and when there is a finger touch, since the light intensity reflected by the valley and the ridge of the finger is inconsistent, the magnitude of the current of the data line 23 at the corresponding position is inconsistent, and the data signal processing circuit 24 can be based on the data line 23 The magnitude of the current is used to identify the location of the valleys and ridges of the fingers, which in turn form a fingerprint image of the finger.

Only four gate lines 21 and four data lines 23 are shown in Fig. 5a for illustration. It should be noted that the ellipsis in FIG. 5a indicates that the sensing substrate according to an embodiment of the present disclosure may further include more gate lines 21 and more data lines 23. The number of gate lines 21 and data lines 23 is not limited here. In addition, V _{d in} Fig. 5b indicates the voltage input to the reference signal line 13.

Embodiments of the present disclosure also provide a detection method for fingerprint recognition using the above sensing substrate. Since the principle of the detection method is as described above, it will not be described here.

6 is a flow diagram of a method of sensing a substrate for fingerprinting using an embodiment in accordance with the present disclosure. As shown in FIG. 6, the detecting method includes: in S301, inputting an on signal to a gate of a thin film transistor on a sensing substrate; and in S302, detecting a fingerprint identification signal at an output end of the thin film transistor to identify a signal according to the fingerprint Determine the fingerprint pattern.

In the detecting method of performing fingerprint recognition using the sensing substrate according to the embodiment of the present disclosure, since the light intensity reflected by the finger valley and the ridge is different, the photocurrent formed in the fingerprint recognizing portion at the corresponding position is different, and thus can pass Inputting an enable signal to the gate of the thin film transistor, for example, inputting an enable signal in a row-by-row or column-by-column manner, so that the input terminal and the output terminal of the thin film transistor are turned on row by row or column by column, thereby detecting the output of each thin film transistor. The fingerprint identification signal of the end determines the fingerprint pattern.

It should be noted that the sensing substrate in the detecting method provided by the embodiment of the present disclosure refers to a sensing substrate in which the photosensitive device layer includes a light shielding portion and a fingerprint recognition portion.

In some embodiments, the sensing substrate can also implement touch detection.

For example, the touch detection method may include detecting a touch detection signal at an output end of the thin film crystal to determine a touch position according to the touch detection signal. The fingerprint recognition unit is multiplexed into a touch electrode. When the finger touches the display screen, the light reflected by the finger causes the fingerprint recognition portion to form a photocurrent. Thereby, the touch position can be determined based on the current change at the output end of the thin film transistor electrically connected to the fingerprint recognition portion. Specifically, the touch detection and the fingerprint recognition can be respectively implemented by means of time-sharing driving. During the touch detection period, the touch detection signal is detected at the output end of each thin film transistor, and the touch position is determined according to the touch detection signal.

For example, the sensing substrate may include a touch detection signal line disposed in the same layer as the gate of the thin film transistor, and the touch detection signal line is electrically connected to the corresponding light shielding portion. Therefore, the touch detection method may include detecting the touch detection signal. The touch detection signal of the line determines the touch position according to the touch detection signal.

Specifically, the touch detection position can be determined by reading the current of each touch detection signal line due to each touch detection signal line electrically connected to the corresponding light shielding portion. If the current of the touch detection signal line changes at a certain position, the position of the corresponding light shielding portion is touched. Therefore, the fingerprint recognition function can be implemented by the fingerprint recognition unit, and the touch detection function can be implemented by the light shielding portion. Here, the fingerprint recognition and the touch detection can be independent of each other, and the fingerprint recognition unit does not need to be multiplexed into the touch electrodes, thereby simplifying the driving timing.

It is easy to understand that in order to realize the verification of the fingerprint information or the calculation of the touch position, the above-mentioned detection signal line is connected to the corresponding logic operation circuit to verify the fingerprint information or calculate the position of the touch based on the detected signal. The so-called logic operation circuit can be designed as an integrated circuit (IC) that performs the above functions, or a general-purpose processor such as a central processing unit (CPU), a field programmable logic array (FPGA), an application specific integrated circuit (ASIC). Etc., it is also possible to share the controller with a device such as a display panel.

Embodiments of the present disclosure also provide a sensing board including the sensing substrate of the above embodiment. The sensing board can be used, for example, as a fingerprint sensing component on a fingerprint lock, a touch sensing component on a digital tablet, a fingerprint on a time attendance machine, or a palm print sensing component.

Embodiments of the present disclosure also provide a display panel. The display panel includes the sensing substrate of the above embodiment. The type of the display panel is not particularly limited, and may be, for example, an LCD display panel, an OLED display panel, a QLED display panel, a Micro LED display panel, or the like.

For example, the sensing substrate may share the substrate with the array substrate of the display panel to simplify the design, thereby sensing the thin film transistor and the photosensor layer on the substrate as a whole of the sensing device and the sub-pixels of the pixels on the display substrate ( For example, R, G, B sub-pixels together form a pixel unit structure.

Embodiments of the present disclosure also provide a display device. The display device includes the above display panel. The display device can be applied to any product or component having a display function, such as a mobile phone, a tablet computer, a television, a display, a notebook computer, a digital photo frame, a navigator, and the like.

It will be apparent to those skilled in the art that various changes and modifications can be made in the present disclosure without departing from the spirit and scope of the disclosure. Thus, it is intended that the present invention cover the modifications and the modifications

Claims

A sensing substrate includes:

Substrate substrate;

a thin film transistor and a photosensor layer on the base substrate,

Wherein the photosensor layer includes a light shielding portion, an orthographic projection of the light shielding portion on the substrate substrate and an orthographic projection of an active layer of the thin film transistor on the substrate substrate at least partially overlap, and The light shielding portion is located on a side of the thin film transistor from which the active layer faces away from the gate of the thin film transistor.
The sensing substrate according to claim 1, wherein the photosensitive device layer further comprises a fingerprint recognition portion, an orthographic projection of the fingerprint recognition portion on the base substrate and the active layer on the substrate The orthographic projections on the substrate do not overlap,

The fingerprint recognition unit is electrically connected to one of the first pole and the second pole of the thin film transistor.
The sensing substrate of claim 2, wherein the gate is between the substrate substrate and the active layer, and

The fingerprint recognition unit is disposed in the same layer as the light shielding portion, and the fingerprint recognition portion and the light shielding portion are spaced apart from each other.
The sensing substrate according to claim 3, wherein the light shielding portion functions as a touch sensing portion.

The sensing substrate further includes a touch detection signal line disposed in the same layer as the gate, and the touch detection signal line is electrically connected to the corresponding light shielding portion.
The sensing substrate according to claim 4, wherein the touch detection signal lines are in one-to-one correspondence with the light shielding portions.
The sensing substrate according to claim 4, wherein each of the touch detection signal lines corresponds to a plurality of the light shielding portions.
The sensing substrate of claim 4, further comprising at least one reference signal line disposed in the same layer as the gate,

The at least one reference signal line is electrically coupled to at least one of the light shielding portion and the fingerprint recognition portion to provide a corresponding bias voltage.
The sensing substrate according to claim 7, wherein the bias voltage is supplied to the light shielding portion and the fingerprint recognition portion through the same one of the reference signal lines.
The sensing substrate of claim 7, further comprising:

a gate insulating layer between the active layer and the gate;

a first insulating layer between the active layer and the photosensor layer;

a second insulating layer on a side of the photosensor layer that faces away from the gate.
The sensing substrate of claim 9, further comprising: a first conductive portion and a second conductive portion disposed in the same layer as one of the first and second poles of the thin film transistor;

a third conductive portion and a fourth conductive portion disposed on the same side of the second insulating layer facing away from the substrate substrate,

The at least one reference signal line is electrically connected to at least one of the light shielding portion and the fingerprint recognition portion through the first conductive portion and the third conductive portion.

The touch detection signal line is electrically connected to the light shielding portion through the second conduction portion and the fourth conduction portion.
The sensing substrate according to any one of claims 3 to 10, further comprising a protective layer on a side of the photosensitive device layer facing away from the substrate substrate.
The sensing substrate of claim 2, wherein the gate is located on a side of the active layer away from the substrate.
The sensing substrate according to claim 12, further comprising a protective layer on a side of the fingerprint identifying portion facing away from the substrate.
The sensing substrate of claim 1 wherein the material of the photosensor layer comprises a PIN-type semiconductor material.
A sensing plate comprising the sensing substrate according to any one of claims 1 to 14.
A display panel comprising the sensing substrate according to any one of claims 1 to 14.
A display device comprising the display panel according to claim 16.