CN112993184B

CN112993184B - Display substrate and display device

Info

Publication number: CN112993184B
Application number: CN202110166665.XA
Authority: CN
Inventors: 任怀森; 侯鹏; 夏维; 李�杰
Original assignee: BOE Technology Group Co Ltd; Chengdu BOE Optoelectronics Technology Co Ltd
Current assignee: BOE Technology Group Co Ltd; Chengdu BOE Optoelectronics Technology Co Ltd
Priority date: 2021-02-04
Filing date: 2021-02-04
Publication date: 2023-05-26
Anticipated expiration: 2041-02-04
Also published as: CN112993184A

Abstract

A display substrate and a display apparatus, the display substrate including a base, a light-sensitive device and a light-emitting device provided on the base, and further including a reflection structure and a light-shielding structure corresponding to the light-sensitive device, the reflection structure being configured to reflect light incident from a side of the reflection structure away from the base, and the reflected light being at least partially directed toward the corresponding light-sensitive device; the shading structure is arranged on one side, far away from the substrate, of the photosensitive device, and the orthographic projection of the photosensitive device is at least partially positioned in the orthographic projection of the shading structure on a plane parallel to the substrate. According to the scheme provided by the embodiment, the shading structure is used for shading light, and the reflecting structure is used for making reflected light incident on the photosensitive device, so that the signal to noise ratio can be improved.

Description

Display substrate and display device

Technical Field

Embodiments of the present disclosure relate to, but are not limited to, display technologies, and more particularly, to a display substrate and a display device.

Background

Not only are the application fields of the organic light emitting display device diversified, but also some products are gradually developed toward multifunction, such as optical in-screen fingerprints. The current fingerprint identification technology mainly comprises a capacitive type, an optical type and an ultrasonic type. The capacitor can only be integrated on the Cover plate (Cover) due to the limit of the penetration distance, and can not be used under the screen; ultrasonic wave is not easy to integrate in the screen due to material limitation. The full screen is in accordance with the optical mode and the ultrasonic mode only, the full screen and the large screen are in accordance, and the screen can be integrated, preferably the optical mode.

Disclosure of Invention

The following is a summary of the subject matter described in detail herein. This summary is not intended to limit the scope of the claims.

The embodiment of the application provides a display substrate and a display device, which can improve the signal-to-noise ratio of fingerprint identification

In one aspect, embodiments of the present application provide a display substrate, including a substrate, a light-sensitive device and a light-emitting device disposed on the substrate, and further including a reflective structure and a light-shielding structure corresponding to the light-sensitive device, where the reflective structure is configured to reflect light incident from a side of the reflective structure away from the substrate, and the reflected light is at least partially directed toward the corresponding light-sensitive device; the shading structure is arranged on one side, far away from the substrate, of the photosensitive device, and the orthographic projection of the photosensitive device is at least partially positioned in the orthographic projection of the shading structure on a plane parallel to the substrate.

In an exemplary embodiment, the reflective structure includes a reflective layer, the photosensitive device is disposed between the substrate and the light emitting device, and the reflective layer is disposed between the photosensitive device and the substrate.

In an exemplary embodiment, the display substrate further includes a thin film transistor disposed between the base and the light emitting device, the thin film transistor including an active layer, a gate electrode, a source electrode, and a drain electrode sequentially disposed on the base, the reflective layer being disposed in the same layer as the gate electrode.

In an exemplary embodiment, the display substrate further includes a thin film transistor disposed between the base and the light emitting device, and a light shielding layer disposed at a side of the thin film transistor adjacent to the base, the reflective layer being disposed at the same layer as the light shielding layer.

In an exemplary embodiment, the light shielding structure includes a light shielding layer provided with a light transmitting portion corresponding to the photosensitive device, and an orthographic projection of the photosensitive device is located within an orthographic projection of the light shielding layer and an orthographic projection of the light transmitting portion is located outside the orthographic projection of the photosensitive device on a plane parallel to the substrate.

In an exemplary embodiment, the light emitting device includes a first electrode, a light emitting layer, and a second electrode sequentially disposed, the first electrode is disposed on a side of the light emitting layer near the substrate, and the first electrode is multiplexed as the light shielding layer.

In an exemplary embodiment, the display substrate further includes an encapsulation layer disposed on a side of the light emitting device away from the substrate, the reflective structure is disposed on a side of the encapsulation layer away from the substrate, the reflective structure includes a first reflective layer and a second reflective layer disposed in sequence, the first reflective layer is disposed on a side of the second reflective layer close to the substrate, the light emitting device includes a light emitting layer, on a plane parallel to the substrate, an orthographic projection of the first reflective layer overlaps an orthographic projection of the second reflective layer, and a partial orthographic projection of the first reflective layer is disposed outside an orthographic projection of the second reflective layer, and an orthographic projection of the first reflective layer and an orthographic projection of the second reflective layer are disposed outside an orthographic projection of the light emitting layer.

In an exemplary embodiment, the second reflective layer is multiplexed as the light shielding structure.

In an exemplary embodiment, the front projection of the first reflective layer is annular in a plane parallel to the substrate, the front projection of the first reflective layer surrounding the front projection of the photosensitive device.

In an exemplary embodiment, the display substrate further includes a first touch electrode layer and a second touch electrode layer sequentially disposed on a side of the encapsulation layer away from the substrate, the first reflection layer and the first touch electrode layer are disposed on the same layer, and the second reflection layer and the second touch electrode layer are disposed on the same layer.

In an exemplary embodiment, the light emitting device further includes a first electrode and a second electrode disposed on both sides of the light emitting layer, respectively, the first electrode is disposed on a side of the light emitting layer near the substrate, the photosensitive device is disposed on the same layer as the light emitting device, a pixel defining layer is disposed between the first electrode and the light emitting layer, and the pixel defining layer is made of an opaque material.

In an exemplary embodiment, the display substrate further includes: and the light converging device is arranged on one side of the reflecting structure far away from the substrate, and at least part of light converged by the light converging device is incident to the reflecting structure.

In yet another aspect, an embodiment of the present disclosure provides a display device including the above display substrate.

The embodiment of the application comprises a display substrate and a display device, wherein the display substrate comprises a substrate, a photosensitive device and a light emitting device which are arranged on the substrate, and further comprises a reflecting structure and a shading structure which correspond to the photosensitive device, wherein the reflecting structure is configured to reflect light rays which are incident from the side, far away from the substrate, of the reflecting structure, and at least part of the reflected light rays face the corresponding photosensitive device; the shading structure is arranged on one side, far away from the substrate, of the photosensitive device, and the orthographic projection of the photosensitive device is at least partially positioned in the orthographic projection of the shading structure on a plane parallel to the substrate. According to the scheme provided by the embodiment, the shading structure is used for shading light, and the reflecting structure is used for making reflected light incident on the photosensitive device, so that the signal to noise ratio can be improved.

Additional features and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The objectives and other advantages of the invention may be realized and attained by the structure particularly pointed out in the written description and drawings.

Other aspects will become apparent upon reading and understanding the accompanying drawings and detailed description.

Drawings

The accompanying drawings are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate and do not limit the invention.

FIG. 1 is a schematic diagram of a display substrate (with a reflective layer and a gate metal layer disposed on the same layer) according to an exemplary embodiment;

FIG. 2 is a schematic plan view of a display substrate according to an exemplary embodiment;

FIG. 3 is a schematic view of a display substrate (anode enlarged) according to an exemplary embodiment;

FIG. 4 is a schematic view of a display substrate (with a condenser) according to an exemplary embodiment;

FIG. 5 is a schematic view of a display substrate (with a reflective layer and a light shielding layer disposed on the same layer) according to an exemplary embodiment;

FIG. 6 is a schematic view of a display substrate (a photosensitive device is disposed on a surface of a base) according to an exemplary embodiment;

FIG. 7 is a schematic view of a display substrate (anode enlarged) according to an exemplary embodiment;

FIG. 8 is a schematic view of a display substrate (anode enlarged) according to an exemplary embodiment;

FIG. 9 is a schematic diagram of a display substrate (with a reflective layer and a light shielding layer on the same layer) according to an exemplary embodiment;

FIG. 10 is a schematic diagram of a display substrate (a reflective structure is located on a touch layer) according to an exemplary embodiment;

FIG. 11 is a schematic plan view of a first reflective layer and a photosensitive device provided in an exemplary embodiment;

FIG. 12 is a schematic view of a display substrate according to an exemplary embodiment;

fig. 13 is a schematic view of a display substrate (with a condenser) according to an exemplary embodiment.

Detailed Description

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. Embodiments and features of embodiments in this application may be combined with each other arbitrarily without conflict.

The steps illustrated in the flowchart of the figures may be performed in a computer system, such as a set of computer-executable instructions. Also, while a logical order is depicted in the flowchart, in some cases, the steps depicted or described may be performed in a different order than presented herein.

Unless defined otherwise, technical or scientific terms used in this disclosure should be given the ordinary meaning as understood by one of ordinary skill in the art to which this invention belongs.

In the drawings, the size of each constituent element, the thickness of a layer, or a region may be exaggerated for clarity. Accordingly, embodiments of the present disclosure are not necessarily limited to this size, and the shapes and sizes of the various components in the drawings do not reflect actual proportions. Furthermore, the drawings schematically show ideal examples, and the embodiments of the present disclosure are not limited to the shapes or the numerical values shown in the drawings.

The ordinal numbers of "first", "second", "third", etc. in the present disclosure are provided to avoid intermixing of constituent elements, and do not denote any order, quantity, or importance.

In the present disclosure, for convenience, terms such as "middle", "upper", "lower", "front", "rear", "vertical", "horizontal", "top", "bottom", "inner", "outer", and the like are used to describe positional relationships of the constituent elements with reference to the drawings, only for convenience in describing the present specification and simplifying the description, and do not indicate or imply that the apparatus or elements to be referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as limiting the present disclosure. The positional relationship of the constituent elements is appropriately changed according to the direction in which the respective constituent elements are described. Therefore, the present invention is not limited to the words described in the disclosure, and may be replaced as appropriate.

In this disclosure, the terms "mounted," "connected," and "connected" are to be construed broadly, unless otherwise specifically indicated and defined. For example, it may be a fixed connection, a removable connection, or an integral connection; may be a mechanical connection, or an electrical connection; may be directly connected, or indirectly connected through intermediate members, or may be in communication with the interior of two elements. The specific meaning of the terms in this disclosure will be understood by those of ordinary skill in the art in the specific context.

In this disclosure, a transistor refers to an element including at least three terminals of a gate electrode, a drain electrode, and a source electrode. The transistor has a channel region between a drain electrode (a drain electrode terminal, a drain region, or a drain electrode) and a source electrode (a source electrode terminal, a source region, or a source electrode), and a current can flow through the drain electrode, the channel region, and the source electrode. In the present disclosure, a channel region refers to a region through which current mainly flows. In this disclosure, "source electrode" and "drain electrode" may be interchanged.

In this disclosure, "film" and "layer" may be interchanged. For example, the "conductive layer" may be sometimes replaced with a "conductive film". In the same manner, the "insulating film" may be replaced with the "insulating layer" in some cases.

In current organic light emitting diode (Organic Light Emitting Diode, OLED) films, the transmittance of the inorganic and organic layers is substantially greater than 90%, and the reflectance after the current aluminum (Al) metal Pattern (Pattern) is substantially greater than 80%. Thus, fingerprint recognition can be achieved using light reflection.

In the optical method, the photosensitive device realizes photoelectric conversion by receiving signal light, thereby realizing the function of optical fingerprint identification. However, the photosensor receives noise light (i.e., light other than the signal light) outside the panel in addition to the signal light, and thus it is necessary to increase the ratio of the signal light to the noise light to improve the signal-to-noise ratio. The reflective layer pattern and the light shielding layer pattern are prepared by using a metal film layer of a Back Plate (BP) process section or a Flexible Multi-layer on cell (FMLOC) process section in the embodiments of the present disclosure to enhance the signal to noise ratio.

The embodiment of the disclosure provides a display substrate, which comprises a substrate, a photosensitive device and a light emitting device, wherein the photosensitive device and the light emitting device are arranged on the substrate, and the display substrate further comprises a reflecting structure and a shading structure, wherein the reflecting structure corresponds to the photosensitive device and is configured to reflect light rays incident from the side, far away from the substrate, of the reflecting structure, and at least part of the reflected light rays face the corresponding photosensitive device; the shading structure is arranged on one side, far away from the substrate, of the photosensitive device, and the orthographic projection of the photosensitive device is at least partially positioned in the orthographic projection of the shading structure on a plane parallel to the substrate. The reflective structure may comprise one reflective layer or, alternatively, a plurality of reflective layers. The light shielding structure may use an existing film layer of the display substrate, or a newly added film layer, or one of a plurality of reflective layers.

In an exemplary embodiment, a reflective layer pattern may be prepared using a metal film layer (such as a gate metal layer gate or a light shielding Layer (LS)) of a BP process, and a photosensitive device may be prepared under the anode and the light Emitting Layer (EL) and over the reflective layer. Light emitted by the light-emitting layer is reflected to the reflecting layer by the finger, and is reflected to the photosensitive device (this is signal light) by the emitting layer; in addition, the light blocking effect of the anode metal is utilized, so that the light emitted by the light emitting layer directly and external ambient light are prevented from being received by the photosensitive device, and noise light is reduced. The scheme provided by the embodiment can enhance the signal to noise ratio.

Fig. 1 is a schematic view of a display substrate according to an exemplary embodiment. The display substrate may include a plurality of photosensitive devices and a plurality of reflective layers, only one of which is illustrated in fig. 1. As shown in fig. 1, the display substrate may include: the substrates may include a first substrate 10a and a second substrate 10b disposed on the first substrate 10 a. The display substrate further includes an active layer 11 disposed on the substrate, a first insulating layer 12 disposed on a side of the active layer 11 remote from the substrate, a first gate metal layer disposed on a side of the first insulating layer 12 remote from the substrate, the first gate metal layer may include a gate electrode 13 and a reflective layer 14, a second insulating layer 15 disposed on a side of the first gate metal layer remote from the substrate, a third insulating layer 16 disposed on a side of the second insulating layer 15 remote from the substrate, a source/drain electrode layer disposed on a side of the third insulating layer 16 remote from the substrate, the source/drain electrode layer may include a source electrode 17, a drain electrode 18 and a photosensitive device 19, a fourth insulating layer 20 disposed on a side of the source/drain electrode layer remote from the substrate, an anode 21 disposed on a side of the fourth insulating layer 20 remote from the substrate, a pixel defining layer 22 disposed on a side of the anode 21 remote from the substrate, a light emitting layer 23 disposed on a side of the pixel defining layer 22 remote from the substrate, a side of the light emitting layer 23 disposed on a side of the light emitting layer 23 remote from the substrate, a side of the light emitting layer 24 and a side of the light emitting layer 24 disposed on a side of the substrate remote from the substrate, and a cover plate 25. A cathode (not shown in fig. 1) is also provided between the light emitting layer 23 and the encapsulation layer 24.

According to the scheme provided by the embodiment, the signal light emitted by the light emitting layer 23 is reflected to the reflecting layer 14 through the finger 30, the reflecting layer 14 reflects the light to the light inlet side of the photosensitive device 19, the light reflection is effectively utilized to realize the light path optimization, the finger reflected light enters the photosensitive device after primary reflection, the light loss is small, and the detection sensitivity is high. In addition, in the embodiment, the reflection layer is prepared by using the existing film layer, a new film layer is not added, the process is simplified, and the cost is reduced.

The principle of fingerprint identification of the display substrate is as follows: when fingerprint recognition is performed, the finger 30 of the user presses the cover plate 25, and the light emitted from the light emitting layer 23 irradiates the cover plate 25. Since the valleys of the finger do not actually contact with the cover plate 25, the critical angles of total reflection of the light rays at the valleys and the ridges of the fingerprint are different, and the light intensities of the light rays received by the photosensitive device 19 are different, so that electric signals with different intensities are generated, the valleys and the ridges of the fingerprint can be judged, and a fingerprint pattern is generated.

In this embodiment, the active layer 11, the gate electrode 13, the source electrode 17, and the drain electrode 18 constitute a thin film transistor, which is electrically connected to the anode 21. In the present embodiment, the thin film transistor is a top gate structure, but not limited thereto, and the thin film transistor may be a bottom gate structure.

In an exemplary embodiment, the substrate, such as a flexible substrate, the first substrate 10a may be made of a flexible material, which may be Polyimide (PI), polyethylene terephthalate (PET), or a surface-treated polymer film. The second substrate 10b is a buffer layer, and may be made of silicon nitride SiNx, silicon oxide SiOx, or the like, may be a single layer, or may be a multi-layer structure of silicon nitride/silicon oxide. In other embodiments, the substrate may also be other structures, for example, the substrate may further include a third substrate disposed on the second substrate 10b, and the third substrate may be made of a flexible material.

In an exemplary embodiment, the active layer 11 includes a semiconductor. For example, polycrystalline silicon, single crystal silicon, amorphous silicon, or a non-silicon-based material such as an oxide semiconductor.

In an exemplary example, the first, second, third, and fourth insulating

layers

12, 15, 16, and 20 may employ silicon oxide (SiOx), silicon nitride (SiNx), silicon oxynitride (SiON), or the like, may be a single-layer structure, or may be a multi-layer composite structure.

In an exemplary embodiment, the gate electrode 13, the source electrode 17 and the drain electrode 18 may be made of a metal material, such as silver Ag, copper Cu, aluminum Al, molybdenum Mo, etc., or an alloy material of the above metals, such as aluminum neodymium alloy AlNd, molybdenum niobium alloy MoNb, etc., may be a single-layer structure, or may be a multi-layer composite structure, such as Mo/Cu/Mo, etc.

In an exemplary embodiment, the orthographic projection of the photosensitive device 19 is located within the orthographic projection of the anode 21 in a plane parallel to the substrate. According to the scheme provided by the embodiment, the anode 21 can shield light from external light and light of the light-emitting layer, so that the external light and the light emitted by the light-emitting layer are prevented from directly entering the photosensitive device 19, noise light is reduced, and the signal to noise ratio is improved.

Fig. 2 is a schematic plan view of a light emitting device, a photosensitive device, and a reflective layer according to an exemplary embodiment. The light emitting device 31 may include an anode 21, a cathode, and a light emitting layer 23 between the anode 21 and the cathode. As shown in fig. 2, the display substrate may include a plurality of light emitting devices 31, a light sensing device 19, and a reflective layer 14. The light emitting device 31 may be an organic light emitting diode, or other light emitting device. The light emitting device 31 may include a red light emitting device (R), a green light emitting device (G), and a blue light emitting device (B), or may include a white light emitting device. On a plane parallel to the substrate, the front projection of the light sensitive device 19 is located within the front projection of the light emitting device 31, e.g. the front projection of the light sensitive device 19 is located within the front projection of the anode 21. The front projection of the photosensitive device 19 may be located within the front projection of the reflective layer 14 in a plane parallel to the substrate, but the embodiment of the present application is not limited thereto, and the front projection of the photosensitive device 19 may be located outside the front projection of the reflective layer 14, or the front projection of the photosensitive device 19 may be located partially within the front projection of the reflective layer 14 and partially outside the front projection of the reflective layer 14. The cross-sectional shapes of the reflective layer 14 and the photosensitive device 19 in a plane parallel to the substrate are not limited, and may be square, circular, irregular, or the like.

In an exemplary embodiment, the anode 21 may be an opaque electrode, or a stacked structure of an opaque electrode and a transparent electrode. Examples of the material forming the transparent electrode include Indium Tin Oxide (ITO), indium Zinc Oxide (IZO), zinc oxide, and indium oxide, and examples of the material forming the opaque electrode include lithium (Li), aluminum (Al), magnesium (Mg), silver (Ag), nickel (Ni), and chromium (Cr).

In an exemplary embodiment, the reflective layer 14 may be made of opaque metals such as lithium, aluminum, magnesium, silver, nickel, chromium, molybdenum, copper, titanium, or alloys of these materials.

In an exemplary embodiment, the photosensitive device 19 may include a photodiode, a photoresistor, a phototransistor, and the like. The photodiode may be a PN type photodiode, or a PIN type photodiode, or an organic photodiode (Organic Photo Diode, or Organic Photosensitive Diode, OPD).

In an exemplary embodiment, the photosensitive device 19 may include a first pole, a photoelectric conversion layer, and a second pole disposed in this order; the material of the first electrode may be a transparent conductive material, and the first electrode is located between the photoelectric conversion layer and the substrate. The material of the first electrode may be a metal Oxide such as zinc Oxide (ZnO), indium Tin Oxide (ITO), indium gallium zinc Oxide (Indium GalliumZinc Oxide, IGZO), or other transparent conductive materials, which are not limited herein. Light reflected by the reflective layer 14 may enter the photoelectric conversion layer from the first pole. The first electrode of the photosensitive device 19 may be arranged in the same layer as the source electrode 17 and the drain electrode 18.

In an exemplary embodiment, the photosensitive device 19 may not be disposed at the source-drain electrode layer, and other film layers disposed between the reflective layer 14 and the anode 21, for example, may be disposed between the second insulating layer 15 and the third insulating layer 16. When the photosensitive device 19 is arranged on the source electrode layer and the drain electrode layer, the process is simple and easy to realize.

In an exemplary embodiment, a second gate metal layer may be disposed between the first gate metal layer and the photosensitive device 19, where the first gate metal layer is disposed with a gate electrode and a first capacitor electrode, and the second gate metal layer is disposed with a second capacitor electrode, where the first capacitor electrode and the second capacitor electrode correspond in position, and form a storage capacitor. In this embodiment, the reflective layer 14 may be disposed on the same layer as the second capacitor electrode, i.e., on the second gate metal layer. The solution provided by this embodiment can shorten the distance between the reflecting layer 14 and the cover plate 25, i.e. shorten the light propagation path and reduce the light loss.

In order to further shield noise light (light other than signal light, such as incoming ambient light or light emitted by a light emitting layer, which is reflected by other film layers other than the finger) to enhance the signal to noise ratio, the anode range may be enlarged, and holes or slits may be left in the path of the finger reflected light. As shown in fig. 3, the present embodiment provides a display substrate, in which the structure of the display substrate except for the anode can refer to the embodiment shown in fig. 1, in this embodiment, the area of the anode 21 is enlarged, and a hole or a gap is reserved between adjacent anodes 21 for the finger to reflect light to pass through, and the adjacent anodes 21 are insulated from each other. In the display substrate, holes or slits may be reserved between the anodes 21 near the photo-sensor 19, and the distance between the anodes 21 away from the photo-sensor 19 may be larger. The size of the holes or slits may be set as desired in a plane parallel to the substrate, and the range of incidence angles of the reflected light received by the photosensitive device 19 may be adjusted by adjusting the size of the light-transmitting holes or slits. In the solution provided in this embodiment, holes or gaps are reserved between the anodes 21, so that most of the ambient light is blocked by the anodes 21, and the light reflected by the light emitting device after being irradiated to the finger enters the reflecting layer 14 through the holes or gaps, and is reflected by the reflecting layer 14 to the photosensitive device 19. The solution provided by this embodiment reduces the ambient light received by the photosensitive device 19 and improves the signal-to-noise ratio due to the expansion of the anode 21.

In the above embodiment, the anode 21 is used as the light shielding structure to shield the photosensitive device. In another embodiment, a light shielding layer may be provided to shield the photosensitive device. In an exemplary embodiment, the display substrate may include a light shielding layer disposed on a side of the light-sensing device 19 remote from the base, the light shielding layer being provided with a light-transmitting portion corresponding to the light-sensing device 19, and an orthographic projection of the light-sensing device 19 may be located within an orthographic projection of the light shielding layer, and an orthographic projection of the light-transmitting portion may be located outside an orthographic projection of the light-sensing device 19 on a plane parallel to the base. The light transmitting portion is located in the propagation path of the finger reflected light to the reflective layer 14. Light emitted from the light emitting device is reflected by the finger, enters the reflective layer 14 through the light transmitting portion, and is reflected by the reflective layer 14 to the photosensitive device 19. The light shielding layer may shield external ambient light from entering the light sensitive device 19 and shield light emitted by the light emitting device from entering the light sensitive device 19 from a side of the light shielding layer remote from the substrate via the inner film layer. The light shielding layer may include a plurality of light shielding portions and a plurality of light transmitting portions. The light-transmitting portion may be a hole or a slit or may be prepared using a light-transmitting material. The light transmitting portion may be, for example, a plurality of light transmitting holes surrounding the photosensor 19, or may be an annular light transmitting region (may be a circular ring, or a square ring, or the like) surrounding the photosensor 19, or may be a plurality of light transmitting slits surrounding the photosensor 19, or the like. The light shielding portion may be implemented using an organic material containing a light shielding colorant (such as a black pigment or a black dye) or a light shielding metal.

The light shielding layer may be implemented by multiplexing other functional film layers of the display substrate, or a newly added film layer may be used. In an exemplary embodiment, the light shielding layer may be implemented as a multiplexed pixel definition layer 22. The pixel defining layer 22 may be prepared using a light shielding material and form a light transmitting portion. When the shading layer is reused by the existing film layer, the complexity of the panel structure can be reduced, the process is simplified, and the cost is reduced.

In an exemplary embodiment, the light shielding layer may be implemented using a fourth insulating layer 20, and the photosensitive device 19 may be disposed on the surface of the second insulating layer 15.

In an exemplary embodiment, in order to better collect the reflected signal light, a condenser may be fabricated at the corresponding film layer. For example, the optical concentrator, such as a lens, is fabricated using a film package (Thin Film Encapsulation, TFE) upper mask layer of FMLOC process.

Fig. 4 is a schematic view of a display substrate according to an exemplary embodiment. As shown in fig. 4, the display substrate provided in this embodiment further includes a condenser 40 disposed on a side of the reflective layer 14 away from the base. In this embodiment, the condenser 40 may be disposed at a side of the encapsulation layer 24 away from the substrate, and the cover plate 25 is disposed at a side of the substrate, but is not limited thereto, for example, the condenser 40 may be disposed between the third insulation layer 16 and the fourth insulation layer 20. The concentrators 40 may be in one-to-one correspondence with the reflective layers 14. The condenser 40 may refract the incident light such that the incident light is concentrated. The condenser 40 may collect the light reflected by the finger and emitted from the light emitting layer 23, and then make the light incident on the reflecting layer 14. Concentrator 40 may be bonded between encapsulation layer 24 and cover plate 25 using an adhesive. The condenser 40 may be a convex lens, a prismatic lens, or the like. In this embodiment, the light intensity of the light incident on the photosensitive device 19 can be enhanced by condensing the light using the condenser 40, so that the sensitivity of fingerprint detection can be improved and the contrast of the fingerprint image can be improved.

Fig. 5 is a schematic view of a display substrate according to an exemplary embodiment. In this embodiment, the display substrate includes a base and a thin film transistor disposed on the base, where a Light shielding layer (i.e., a Light Shield layer, LS layer) is disposed on a side of the thin film transistor near the base, and the Light shielding layer can prevent Light from the base side from irradiating the thin film transistor, and the display substrate further includes a reflective layer disposed on the same layer as the Light shielding layer. As shown in fig. 5, the display substrate includes a base, the base includes a first base 10a and a second base 10b, a reflective layer 14 and a light shielding layer (not shown in fig. 5) are disposed between the first base 10a and the second base 10b, the display substrate further includes an active layer 11 disposed on the second base 10b, a first insulating layer 12 disposed on a side of the active layer 11 away from the base, a gate metal layer disposed on a side of the first insulating layer 12 away from the base, the gate metal layer may include a gate electrode 13 and a reflective layer 14, a second insulating layer 15 disposed on a side of the gate metal layer away from the base, a third insulating layer 16 disposed on a side of the second insulating layer 15 away from the base, a source drain electrode layer disposed on a side of the third insulating layer 16 away from the base, the source drain electrode layer may include a source electrode 17, a drain electrode 18 and a photosensitive device 19, a fourth insulating layer 20 disposed on a side of the source drain electrode layer away from the base, a fourth insulating layer 20 disposed on a side of the anode layer 20 is disposed on a side of the anode layer 20 away from the base, a side of the anode layer is disposed on a side of the anode layer 22 is disposed on a side of the anode layer 22 is away from the base, and the pixel layer is disposed on a side of the display substrate is disposed on a side of the anode layer is defined layer is disposed on a side of the anode layer is 22 is disposed away from the anode layer is disposed on a side of the anode layer is 22 is disposed on a side is away from the anode layer is 22. A cathode (not shown in fig. 5) is also provided between the light emitting layer 23 and the encapsulation layer 24.

The reflection layer 14 is disposed on the first gate metal layer or the second gate metal layer, and compared with the scheme in which the reflection layer 14 is disposed on the light shielding layer, the reflection layer 14 is shorter in distance from the cover plate 25, the loss of signal light (light reflected by the finger) is smaller, and the signal-to-noise ratio can be improved. In addition, when the position of the photosensitive device 19 is unchanged, and the reflective layer 14 is disposed on the first gate metal layer or the second gate metal layer, the distance between the reflective layer 14 and the photosensitive device 19 is smaller, the loss of signal light is smaller, and the signal-to-noise ratio can be improved.

Fig. 6 is a schematic view of a display substrate according to an exemplary embodiment. As shown in fig. 6, in this embodiment, the reflective layer 14 is located at the same position as in the embodiment shown in fig. 5, and may be provided at the same layer as the light shielding layer. In this embodiment, the photosensitive device 19 may be disposed on the surface of the second substrate 10b, where the first insulating layer 12, the second insulating layer 15, and the third insulating layer 16 are provided with vias exposing the photosensitive device 19, and the fourth insulating layer 20 covers the photosensitive device 19. Compared with the scheme shown in fig. 5, the distance between the photosensitive device 19 and the reflecting layer 14 is shortened, the loss of signal light is reduced, and the signal-to-noise ratio is enhanced. In another embodiment, the photosensitive device 19 may be disposed in other layers between the anode 21 and the reflective layer 14, for example, the photosensitive device 19 may be disposed in the same layer as the gate electrode 13, and so on.

Fig. 7 is a schematic view of a display substrate according to another embodiment. In this embodiment, the reflective layer 14 may be disposed on the same layer as the light shielding layer, and in addition, a light shielding layer is disposed on a side of the reflective layer 14 away from the substrate to shield light from the side of the reflective layer 14 away from the substrate, so as to reduce noise light, and the light shielding layer includes a light transmitting portion for passing finger reflected light. Similar to the solution shown in fig. 3, the anode 21 may be used as a light shielding layer, i.e. the anode 21 may be widened and holes or slits may be left in the path of the reflected light from the finger. As shown in fig. 7, in the present embodiment, the reflective layer 14 is disposed between the first substrate 10a and the second substrate 10b, the anode 21 blocks other light rays (such as ambient light, and light rays emitted from the light emitting layer 23 are reflected by other film layers of the display substrate) from the side of the anode 21 away from the substrate, and the anode 21 is provided with a hole or slit for the finger to reflect light to pass through, enter the reflective layer 14, and enter the photosensitive device 19. The scheme provided by the embodiment reduces the ambient light received by the photosensitive device and improves the signal to noise ratio.

Fig. 8 is a schematic view of a display substrate according to another embodiment. In this embodiment, similar to the scheme shown in fig. 6, the reflective layer 14 may be disposed on the same layer as the light shielding layer, the photosensitive device 19 may be disposed on the surface of the second substrate 10b, the first insulating layer 12, the second insulating layer 15, and the third insulating layer 16 are provided with vias exposing the photosensitive device 19, and the fourth insulating layer 20 covers the photosensitive device 19. In this embodiment, a light shielding layer is disposed on a side of the reflective layer 14 away from the substrate to shield light from the side of the reflective layer away from the substrate, so as to reduce noise light, and the light shielding layer includes a light transmitting portion for allowing finger reflection light to pass through. Similar to the solution shown in fig. 3, the anode can be used as a light shielding layer, i.e. the anode is widened in scope, leaving holes or slits in the path of the reflected light of the finger.

Fig. 9 is a schematic view of a display substrate according to another embodiment. In this embodiment, the reflective layer 14 may be disposed in the same layer as the light shielding layer, the photosensitive device 19 may be disposed in the same layer as the source-drain electrode layer, or the photosensitive device 19 may be disposed on the surface of the substrate, and the condenser 40 may be disposed on the side of the reflective layer 14 away from the substrate, similar to the scheme described in fig. 4. The condenser 40 may refract the incident light such that the incident light is concentrated. The condenser 40 may collect the light reflected by the finger and emitted from the light emitting layer 23, and then make the light incident on the reflecting layer 14. The scheme provided by the embodiment can enhance the signal light and improve the signal to noise ratio.

In an exemplary embodiment, a two-layer reflective layer pattern may be prepared after TFE using a metal film layer of FMLOC, with alternating overlapping portions to facilitate light reflection. In addition, the light blocking effect of FMLOC metal is utilized to prevent the photosensitive device from receiving external ambient light.

Fig. 10 is a schematic view of a display substrate according to another embodiment. As shown in fig. 10, the display substrate provided in this embodiment includes a base, which may include a first base 10a and a second base 10b, an active layer 11 disposed on the base, a first insulating layer 12 disposed on a side of the active layer 11 away from the base, a gate electrode 13 disposed on a side of the first insulating layer 12 away from the base, a second insulating layer 15 disposed on a side of the gate electrode 13 away from the base, a third insulating layer 16 disposed on a side of the second insulating layer 15 away from the base, a source-drain electrode layer disposed on a side of the third insulating layer 16 away from the base, which may include a source electrode 17 and a drain electrode 18, the light-emitting diode comprises a fourth insulating layer 20 arranged on one side of the source-drain electrode layer far away from a substrate, an anode 21 arranged on one side of the fourth insulating layer 20 far away from the substrate, a pixel definition layer 22 arranged on one side of the anode 21 far away from the substrate, a light-emitting layer 23 and a photosensitive device 19 arranged on one side of the pixel definition layer 22 far away from the substrate, an encapsulation layer 24 arranged on one side of the light-emitting layer 23 and the photosensitive device 19 far away from the substrate, a first reflection layer 27 arranged on one side of the encapsulation layer 24 far away from the substrate, a fifth insulating layer 26 arranged on one side of the first reflection layer 27 far away from the substrate, a second reflection layer 28 arranged on one side of the fifth insulating layer 26 far away from the substrate, and a cover plate 25 arranged on one side of the second reflection layer 28 far away from the substrate. A cathode (not shown in fig. 1) is also provided between the light emitting layer 23 and the encapsulation layer 24. On a plane parallel to the substrate, the front projection of the first reflective layer 27 overlaps the front projection of the second reflective layer 28, and a part of the front projection of the first reflective layer 27 is located outside the front projection of the second reflective layer 28, the front projection of the first reflective layer 27 and the front projection of the second reflective layer 28 are located outside the front projection of the light emitting layer 23, and the front projection of the light sensitive device 19 is located at least partially outside the front projection of the first reflective layer 27. The front projection of the photosensitive device 19 is at least partially located within the front projection of the second reflective layer 28 in a plane parallel to the substrate.

In this embodiment, the first reflective layer 27 and the second reflective layer 28 constitute the reflective structure.

In this embodiment, the signal light from the light emitting layer 23 is reflected by the finger 30, enters the first reflecting layer 27, and the signal light is reflected one or more times between the first reflecting layer 27 and the second reflecting layer 28, and enters the photosensor 19. In addition, the second reflective layer 28 may block noise light from entering the photosensitive device 19.

In the scheme provided by the embodiment, the first reflecting layer 27 and the second reflecting layer 28 reflect the reflected light from the finger, and the second reflecting layer 28 shields the noise light, so that the signal to noise ratio can be improved.

In an exemplary embodiment, the fifth insulating layer 26 may be a single-layer structure or a multi-layer composite structure, such as silicon oxide SiOx, silicon nitride SiNx, silicon oxynitride SiON, or the like.

In an exemplary embodiment, the first and second

reflective layers

27 and 28 may be made of opaque metals such as lithium, aluminum, magnesium, silver, nickel, chromium, molybdenum, copper, titanium, or alloys of these materials.

In an exemplary embodiment, the front projection of the photosensitive device 19 may be located within the front projection of the second reflective layer 28. In this embodiment, the second reflective layer 28 shields the photosensitive device, reducing noise light entering the photosensitive device, and improving the signal-to-noise ratio.

In this embodiment, the second reflective layer 28 is multiplexed as a light shielding structure, and in another embodiment, a separate light shielding structure may be provided to shield the photosensitive device 19.

In an exemplary embodiment, the front projection of the first reflective layer 27 may be annular in a plane parallel to the substrate, and the front projection of the first reflective layer 27 surrounds the front projection of the photosensitive device 19. As shown in fig. 11, the front projection of the first reflective layer 27 is, for example, a square ring in a plane parallel to the substrate, and the front projection of the photosensitive device 19 may be located within the inner ring of the front projection of the first reflective layer 27. In another embodiment, the front projection of the photosensitive device 19 may be partially located within the inner ring of the front projection of the first reflective layer 27 and partially located within the front projection of the first reflective layer 27. The shape of the orthographic projection of the first reflective layer 27 shown in fig. 11 is only an example, and other shapes such as a circular ring, a shaped ring, etc. are possible. The orthographic projection shape of the second reflective layer 28 may be square, circular, shaped, etc.

Fig. 12 is a plan view of a light emitting device, a light sensing device, and a reflective structure provided in an exemplary embodiment. As shown in fig. 12, in the present embodiment, the light emitting devices may include a red light emitting device (R), a green light emitting device (G), and a blue light emitting device (B). The front projection of the light emitting device 31 may be located outside the front projection of the light sensitive device 19 and the light emitting device 31 may be located outside the front projection of the first reflective layer 27 and the second reflective layer 28.

For an optical fingerprint function device implemented by OPD, at this time, the photoelectric conversion layer and the light emitting layer of the photosensitive device may be disposed in the same layer. To prevent light from the OLED from directly impinging on the photosensitive device, the OLED is preferably fabricated with a black pixel definition layer (Black Pixel Define Layer, BPDL). In an exemplary embodiment, photosensitive device 19 may be co-located with light emitting device 31. For example, the photosensitive device 19 includes a first pole 19-1, a photoelectric conversion layer 19-2, and a second pole (not shown in fig. 11). The first electrode 19-1 may be disposed in the same layer as the anode 21, the photoelectric conversion layer 19-2 and the light emitting layer 23 may be disposed in the same layer as the cathode of the light emitting device 31. A pixel defining layer 22 is provided between the anode 21 and the light emitting layer 23. The first electrode 19-1 is connected to the drain electrode of a thin film transistor. The pixel defining layer 22 may be a black pixel defining layer, so that light emitted by the light emitting layer 23 is blocked from directly entering the light sensitive device 19. The pixel defining layer 22 may be prepared using an organic material containing a light-shielding colorant such as a black pigment or a black dye. In this embodiment, the material of the second electrode of the photosensitive device 19 may be a transparent conductive material, and the material of the second electrode may be a metal Oxide such as zinc Oxide (ZnO), indium Tin Oxide (ITO), indium gallium zinc Oxide (Indium GalliumZinc Oxide, IGZO), or other transparent conductive materials, which is not limited herein. Light reflected by the first reflective layer 27 and the second reflective layer 28 may enter the photoelectric conversion layer from the second pole.

In an exemplary embodiment, the light sensitive device 19 may be located as shown in fig. 1, 6, i.e. the light sensitive device 19 may be located on the side of the light emitting device close to the substrate, while the reflective structure comprises a first emissive layer 27 and a second reflective layer 28.

In an exemplary embodiment, the display substrate further includes a first touch electrode layer and a second touch electrode layer sequentially disposed on a side of the encapsulation layer away from the substrate, the first reflective layer 27 and the first touch electrode layer are disposed on the same layer, and the second reflective layer 28 and the second touch electrode layer are disposed on the same layer. In the embodiment, the reflection layer is arranged on the same layer as the touch electrode, and the reflection layer is prepared by using the existing film layer, so that the process is simplified, the cost is reduced, and the display substrate has a simpler structure.

Fig. 13 is a schematic view of a display substrate according to an exemplary embodiment. As shown in fig. 13, the display substrate provided in this embodiment, similar to the display substrates shown in fig. 4 and 9, may include a condenser 40. The light collector 40 may be disposed on a side of the fifth insulating layer 26 away from the substrate, and the light emitted by the light emitting layer 40 enters the light collector 40 after being reflected by a finger, and the light collected by the light collector 40 enters the first reflecting layer 27, and then enters the photosensitive device 19 after being reflected by the first reflecting layer 27 and the second reflecting layer 28. In this embodiment, the light intensity incident on the photosensitive device 19 can be enhanced by condensing the light using the condenser, so as to improve the sensitivity of fingerprint detection and improve the contrast of fingerprint images.

The embodiment of the disclosure also provides a display device, which comprises the display substrate of the embodiment. The display device may be: any product or component with 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.

Although the embodiments of the present invention are described above, the embodiments are only used for facilitating understanding of the present invention, and are not intended to limit the present invention. Any person skilled in the art can make any modification and variation in form and detail without departing from the spirit and scope of the present disclosure, but the scope of the present disclosure is to be determined by the appended claims.

Claims

1. A display substrate, characterized by comprising a base, a photosensitive device and a light emitting device which are arranged on the base, and further comprising a reflecting structure and a shading structure which correspond to the photosensitive device, wherein the reflecting structure is configured to reflect light rays which are incident from the reflecting structure away from the base side, and the reflected light rays are at least partially directed towards the corresponding photosensitive device; the shading structure is arranged on one side of the photosensitive device, far away from the substrate, and the orthographic projection of the photosensitive device is at least partially positioned in the orthographic projection of the shading structure on a plane parallel to the substrate;

the display substrate further comprises a packaging layer arranged on one side, far away from the substrate, of the light-emitting device, the reflecting structure is arranged on one side, far away from the substrate, of the packaging layer, the reflecting structure comprises a first reflecting layer and a second reflecting layer which are sequentially arranged, the first reflecting layer is positioned on one side, close to the substrate, of the second reflecting layer, the light-emitting device comprises a light-emitting layer, on a plane parallel to the substrate, orthographic projections of the first reflecting layer and orthographic projections of the second reflecting layer overlap, and partial orthographic projections of the first reflecting layer are positioned outside orthographic projections of the second reflecting layer, and orthographic projections of the first reflecting layer and orthographic projections of the second reflecting layer are positioned outside orthographic projections of the light-emitting layer; the second reflecting layer is multiplexed into the light shielding structure.

2. The display substrate of claim 1, wherein the front projection of the first reflective layer is annular in shape in a plane parallel to the base, the front projection of the first reflective layer surrounding the front projection of the photosensitive device.

3. The display substrate according to claim 1, further comprising a first touch electrode layer and a second touch electrode layer sequentially disposed on a side of the encapsulation layer away from the substrate, wherein the first reflective layer and the first touch electrode layer are disposed on the same layer, and the second reflective layer and the second touch electrode layer are disposed on the same layer.

4. The display substrate according to claim 1, wherein the light emitting device further comprises a first electrode and a second electrode respectively provided on both sides of the light emitting layer, the first electrode is provided on a side of the light emitting layer close to the substrate, the photosensitive device is provided on the same layer as the light emitting device, a pixel defining layer is provided between the first electrode and the light emitting layer, and the pixel defining layer is made of a light impermeable material.

5. The display substrate according to any one of claims 1 to 4, wherein the display substrate further comprises: and the light converging device is arranged on one side of the reflecting structure far away from the substrate, and at least part of light converged by the light converging device is incident to the reflecting structure.

6. A display device comprising the display substrate according to any one of claims 1 to 5.