CN108830168B

CN108830168B - Display panel and display device

Info

Publication number: CN108830168B
Application number: CN201810508768.8A
Authority: CN
Inventors: 李波
Original assignee: Wuhan Tianma Microelectronics Co Ltd
Current assignee: Wuhan Tianma Microelectronics Co Ltd
Priority date: 2018-05-24
Filing date: 2018-05-24
Publication date: 2021-01-12
Anticipated expiration: 2038-05-24
Also published as: CN108830168A

Abstract

The embodiment of the invention discloses a display panel and a display device. The display panel includes: a substrate base plate including a plurality of open areas and a non-open area surrounding the open areas; a pixel defining layer formed on the substrate base plate, a perpendicular projection of the pixel defining layer on the substrate base plate being located within the non-opening area; a thin film encapsulation layer formed on the pixel defining layer on a side facing away from the substrate; and the fingerprint signal acquisition module is positioned at any one of the following positions, between the pixel limiting layer and the film packaging layer, on one side of the film packaging layer, which deviates from the pixel limiting layer, and inside the film packaging layer. The display panel provided by the embodiment of the invention can improve the fingerprint identification precision of the display panel.

Description

Display panel and display device

Technical Field

The embodiment of the invention relates to the technical field of display, in particular to a display panel with a fingerprint identification function and a display device.

Background

The skin lines including fingerprints of each person are different from pattern to pattern, break points and cross points, and are unique and invariable throughout the life. Accordingly, a person can be identified by associating his fingerprint with the person, and by comparing his fingerprint with the pre-stored fingerprint data, the person can verify his true identity, which is known as a fingerprint identification technique. Thanks to the electronic integrated manufacturing technology and the fast and reliable algorithm research, the optical fingerprint identification technology in the fingerprint identification technology has started to enter our daily life, and becomes the most deep, widely applied and mature technology in the current biological detection science.

At present, the optical fingerprint identification technology is combined with the display technology generally, so that the display panel not only has a normal display function, but also can carry out fingerprint identification, the functions of the display panel are enriched, and the safety performance of the display panel is improved. In order to make the display panel have the fingerprint identification function, a fingerprint signal acquisition module, a fingerprint identification circuit and a fingerprint identification light source are usually required to be added in the display panel. The light emitted by the fingerprint identification light source is reflected by the touch main body to form reflected light to enter the fingerprint signal acquisition module so as to perform fingerprint identification. The fingerprint signal collecting module is used for collecting fingerprint signal light (namely the reflected light) and converting the fingerprint signal light into an electric signal. The fingerprint identification circuit is electrically connected with the fingerprint signal acquisition module and is used for controlling the working state of the fingerprint signal acquisition module.

However, in the existing display panel, how to overcome the problem of low fingerprint identification accuracy of the display panel is a significant problem in the industry to design a display panel with high fingerprint identification accuracy.

Disclosure of Invention

The invention provides a display panel and a display device, aiming to improve the fingerprint identification precision of the display panel.

In a first aspect, an embodiment of the present invention provides a display panel, including:

a substrate base plate including a plurality of open areas and a non-open area surrounding the open areas;

a pixel defining layer formed on the substrate base plate, a perpendicular projection of the pixel defining layer on the substrate base plate being located within the non-opening area;

a thin film encapsulation layer formed on the pixel defining layer on a side facing away from the substrate;

and the fingerprint signal acquisition module is positioned at any one of the following positions, between the pixel limiting layer and the film packaging layer, on one side of the film packaging layer, which deviates from the pixel limiting layer, and inside the film packaging layer.

In a second aspect, an embodiment of the present invention further provides a display device, where the display device includes any one of the display panels provided in the embodiments of the present invention.

According to the embodiment of the invention, the fingerprint signal acquisition module is positioned at any one of the following positions, between the pixel limiting layer and the film packaging layer, on the side of the film packaging layer departing from the pixel limiting layer and inside the film packaging layer, so that the fingerprint identification precision effect of the display panel can be improved. In addition, among this application implanting display panel with fingerprint identification module, realized the display panel technique of integrated light sense touch-control unit (accell) for outside the panel possesses fingerprint identification function under the screen, have the slimming advantage concurrently, display panel is more frivolous, and preparation simple process is favorable to promoting display panel's core competitiveness, makes huge contribution for fingerprint identification technique under the screen.

Drawings

Fig. 1 is a schematic structural diagram of a conventional display panel;

FIG. 2 is a schematic structural diagram of a conventional display panel;

fig. 3 is a schematic structural diagram of a display panel according to an embodiment of the present invention;

fig. 4 is a schematic structural diagram of another display panel according to an embodiment of the present invention;

fig. 5 is a schematic structural diagram of another display panel according to an embodiment of the present invention;

fig. 6 is an equivalent circuit diagram of the fingerprint signal acquisition module and the fingerprint identification circuit according to the embodiment of the present invention;

fig. 7 is a schematic structural diagram of another display panel according to an embodiment of the present invention;

fig. 8 is a schematic structural diagram of another display panel according to an embodiment of the present invention;

fig. 9 is a schematic structural diagram of another display panel according to an embodiment of the present invention;

fig. 10 is a schematic structural diagram of another display panel according to an embodiment of the present invention;

fig. 11 is a schematic structural diagram of another display panel according to an embodiment of the present invention;

fig. 12 is a schematic structural diagram of a display device according to an embodiment of the present invention.

Detailed Description

The present invention will be described in further detail with reference to the accompanying drawings and examples. It is to be understood that the specific embodiments described herein are merely illustrative of the invention and are not limiting of the invention. It should be further noted that, for the convenience of description, only some of the structures related to the present invention are shown in the drawings, not all of the structures.

In any embodiment of the invention, the display panel comprises a fingerprint identification light source. In actual setting, the light-emitting units in the display panel can be multiplexed as fingerprint identification light sources, and an external light source can also be used as a fingerprint identification light source. This is not limited by the present application. For convenience of understanding, in the drawings, the formation of fingerprint signal light and the propagation path are drawn by taking the light emitting unit as an example of multiplexing as a fingerprint identification light source.

Fig. 1 is a schematic structural diagram of a conventional display panel. Referring to fig. 1, the display panel includes a substrate base plate 01 and a cover plate 02 opposed thereto. The base substrate 01 includes a plurality of opening areas 011 and non-opening areas 012 surrounding the opening areas 011. A pixel defining layer 03 is formed on the base substrate 01, and a perpendicular projection of the pixel defining layer 03 on the base substrate 01 is located in the non-opening region 012. A plurality of fingerprint signal collection modules 022 are also formed on the base substrate 01. The fingerprint signal collecting module 022 is located on a side of the substrate 01 facing away from the pixel defining layer 03. The display panel further includes a plurality of support columns 04. The support columns 04 are disposed between the substrate base plate 01 and the cover plate 02.

Referring to fig. 1, when touching, a fingerprint signal collecting module 022a corresponds to a region a of a touch subject 05 (e.g., a finger) and is configured to receive fingerprint signal light L01 formed after being reflected by the region a of the touch subject 05. The fingerprint signal collecting module 022b corresponds to a region b of the touch subject 05 (e.g., a finger), and is configured to receive the fingerprint signal light L02 formed after being reflected by the region b of the touch subject 05.

However, the fingerprint signal light L02 formed by reflection in the region b of the touch subject 05 is not directly incident on the fingerprint signal collecting module 022b, but is refracted by the supporting posts 04 and then incident on the fingerprint signal collecting module 022 a. This allows the fingerprint signal collecting module 022a to receive the fingerprint signal light L02 and the fingerprint signal light L01 at the same time. However, for the fingerprint signal collection module 022a, the fingerprint signal light L02 is a crosstalk signal, which affects the accuracy and precision of fingerprint identification performed by the fingerprint signal collection module 022 a. In addition, since the fingerprint signal collection module 022b does not receive the fingerprint signal light L02, signal loss occurs on the fingerprint signal collection module 022b, which also affects the accuracy and precision of fingerprint identification performed by the fingerprint signal collection module 022 b.

Research shows that the more the number of the support columns 04 is, the higher the probability that the fingerprint signal light is refracted by the support columns 04 and then enters other fingerprint signal acquisition modules 022 to form crosstalk signals is, the more serious the fingerprint signal light signal loss is, and the lower the fingerprint identification accuracy of the display panel is.

Fig. 2 is a schematic structural diagram of another conventional display panel. Referring to fig. 2, the display panel includes a substrate base plate 01, and the substrate base plate 01 includes a plurality of opening areas 011 and a non-opening area 012 surrounding the opening areas 011. A pixel defining layer 03 is formed on the base substrate 01, and a perpendicular projection of the pixel defining layer 03 on the base substrate 01 is located in the non-opening region 012. The display panel further includes a plurality of light emitting cells 021 and a plurality of pixel circuits (not shown in fig. 2), and a vertical projection of the light emitting cells 021 on the substrate base plate 01 is located within the opening area 011. The light emitting cell 021 is electrically connected to a corresponding pixel circuit. A plurality of fingerprint signal collection modules 022 are also formed on the base substrate 01. Fingerprint signal collection module 022 is located the side of substrate base plate 010 that deviates from the luminescence unit.

With reference to fig. 2, a plurality of metal layers (e.g., an electrode layer in the light emitting unit 021, a gate metal layer in the pixel circuit, a source/drain metal layer, etc.) are often disposed between the surface of the display panel and the fingerprint identification unit. Here, the "surface of the display panel" refers to a contact surface of the touch main body and the display panel. Light rays emitted by the fingerprint identification light source are reflected by the touch main body and then transmitted to the fingerprint signal acquisition module, and the light rays also need to pass through the metal film layers. These metal film layers can lead to the fact the fingerprint signal light that forms after the reflection of touch main part and shelter from, cause the transmissivity of fingerprint signal light lower for the intensity of the light that fingerprint signal collection module gathered is relatively poor, and display panel's fingerprint identification precision is lower.

It should be noted that, referring to fig. 1 or fig. 2, in an actual manufacturing process of a conventional display panel, a fingerprint signal collection module 022 may be directly formed on a substrate 01 by taking the substrate 01 as a manufacturing substrate; alternatively, the fingerprint signal collection module 022 may be formed by fabricating a substrate from another substrate, and then the fingerprint signal collection module 022 may be attached to the substrate 01 together with the fabricated substrate.

In view of the above, the present application provides a display panel. Fig. 3 is a schematic structural diagram of a display panel according to an embodiment of the present invention. Referring to fig. 3, the display panel illustratively includes a substrate base plate 10, a pixel defining layer 12, a thin film encapsulation layer 20, and a fingerprint signal acquisition module 22. The base substrate 10 includes a plurality of opening regions 101 and a non-opening region 102 surrounding the opening regions 101; the pixel defining layer 12 is formed on the base substrate 10, and a perpendicular projection of the pixel defining layer 12 on the base substrate 10 is located in the non-opening area 102; a thin film encapsulation layer 20 is formed on the pixel defining layer 12 on a side facing away from the base substrate 10; the fingerprint signal acquisition module 22 is located between the pixel defining layer 12 and the thin film encapsulation layer 20.

In the embodiment of the present invention, since the components on the substrate 10 are packaged by using the thin film encapsulation layer 20 instead of the cover substrate, no support column is required, and the fingerprint signal collection module 22 is disposed between the pixel defining layer 12 and the thin film encapsulation layer 20. The possibility that fingerprint signal light is refracted at the support column can be removed through the arrangement, the problem that the fingerprint identification precision of the display panel is low is solved due to the fact that the fingerprint signal light is seriously lost and crosstalk phenomenon under the action of the support column, the detection of actual fingerprint signal light is influenced, and the effect of improving the fingerprint identification precision of the display panel is achieved.

In addition, compare with the present scheme that sets up the fingerprint signal collection module in one side that the substrate base plate deviates from the luminescence unit, be located the pixel with fingerprint signal collection module 22 and prescribe a limit to between layer 12 and the film packaging layer 20, can effectively reduce the quantity of the metal film layer that fingerprint signal light needs to see through, can improve the transmissivity of reverberation for the intensity of the fingerprint signal light that fingerprint signal collection module 22 gathered is higher, has promoted fingerprint identification's performance.

In addition, among this application implanting display panel with fingerprint identification module, realized the display panel technique of integrated light sense touch-control unit (accell) for outside the panel possesses fingerprint identification function under the screen, have the slimming advantage concurrently, display panel is more frivolous, and preparation simple process is favorable to promoting display panel's core competitiveness, makes huge contribution for fingerprint identification technique under the screen.

Fig. 4 is a schematic structural diagram of another display panel according to an embodiment of the present invention. Referring to fig. 4, the display panel illustratively includes a substrate base plate 10, a pixel defining layer 12, a thin film encapsulation layer 20, and a fingerprint signal acquisition module 22. The base substrate 10 includes a plurality of opening regions 101 and a non-opening region 102 surrounding the opening regions 101; the pixel defining layer 12 is formed on the base substrate 10, and a perpendicular projection of the pixel defining layer 12 on the base substrate 10 is located in the non-opening area 102; a thin film encapsulation layer 20 is formed on the pixel defining layer 12 on a side facing away from the base substrate 10; the fingerprint signal acquisition module 22 is located on a side of the thin-film encapsulation layer 20 facing away from the pixel defining layer 12.

In the embodiment of the invention, the components of the substrate are not packaged by using the cover plate, but the components on the substrate 10 are packaged by using the thin film packaging layer 20, so that a support column is not required, and the fingerprint signal acquisition module 22 is arranged on the side, away from the pixel defining layer 12, of the thin film packaging layer 20. The possibility that fingerprint signal light is refracted at the support column can be removed through the arrangement, the problem that the fingerprint identification precision of the display panel is low is solved due to the fact that the fingerprint signal light is seriously lost and crosstalk phenomenon under the action of the support column, the detection of actual fingerprint signal light is influenced, and the effect of improving the fingerprint identification precision of the display panel is achieved.

In addition, compare with the present scheme that sets up the fingerprint signal collection module in one side that the substrate base plate deviates from the luminescence unit, set up fingerprint signal collection module 22 in one side that film packaging layer 20 deviates from pixel and prescribes a limit to layer 12, can effectively reduce the quantity of the metal rete that fingerprint signal light needs to see through, can improve the transmissivity of reverberation for the intensity of the fingerprint signal light that fingerprint signal collection module 22 gathered is higher, has promoted fingerprint identification's performance.

Fig. 5 is a schematic structural diagram of another display panel according to an embodiment of the present invention. Referring to fig. 5, the display panel illustratively includes a substrate base plate 10, a pixel defining layer 12, a thin film encapsulation layer 20, and a fingerprint signal acquisition module 22. The base substrate 10 includes a plurality of opening regions 101 and a non-opening region 102 surrounding the opening regions 101; the pixel defining layer 12 is formed on the base substrate 10, and a perpendicular projection of the pixel defining layer 12 on the base substrate 10 is located in the non-opening area 102; a thin film encapsulation layer 20 is formed on the pixel defining layer 12 on a side facing away from the base substrate 10; the fingerprint signal collection module 22 is located inside the thin film encapsulation layer 20.

In the embodiment of the present invention, the components on the substrate are packaged by the thin film encapsulation layer 20 instead of packaging the components on the substrate by using the cover plate, so that the supporting pillars are not required, and the fingerprint signal acquisition module 22 is disposed inside the thin film encapsulation layer 20. The possibility that fingerprint signal light is refracted at the support column can be removed through the arrangement, the problem that the fingerprint identification precision of the display panel is low is solved due to the fact that the fingerprint signal light is seriously lost and crosstalk phenomenon under the action of the support column, the detection of actual fingerprint signal light is influenced, and the effect of improving the fingerprint identification precision of the display panel is achieved.

In addition, compare with the present scheme that sets up the fingerprint signal collection module in one side that the substrate base plate deviates from the luminescence unit, be located film packaging layer 20 with fingerprint signal collection module 22 inside, can effectively reduce the quantity of the metal film layer that fingerprint signal light needs to see through, can improve the transmissivity of reverberation for the intensity of the fingerprint signal light that fingerprint signal collection module 22 gathered is higher, has promoted fingerprint identification's performance.

In practice, the specific structure of the fingerprint signal acquisition module 22 may be various. The operation principle of the fingerprint signal acquisition module 22 with different structures is slightly different, and the following description is made in detail with reference to the typical example, but not to be construed as limiting the present application.

Fig. 6 is an equivalent circuit diagram of the fingerprint signal acquisition module and the fingerprint identification circuit according to the embodiment of the present invention. Referring to fig. 6, the display panel also illustratively includes a fingerprint recognition circuit 32; the fingerprint signal acquisition module 22 comprises a photodiode D and a first capacitor C1, the photodiode D comprises a first electrode 221 and a second electrode 222, and the second electrode 222 is located on a side of the first electrode 221 facing away from the pixel defining layer (not shown in fig. 6); the first capacitor C1 includes a third electrode 223 and a fourth electrode 224, the second electrode 222 is electrically connected to the third electrode 223, and the first electrode 221 and the fourth electrode 224 are electrically connected to the fingerprint recognition circuit 32. The fingerprint signal acquisition module is simple in circuit structure and easy to manufacture.

The fingerprint identification circuit 32 is used to control the operating state of the fingerprint signal acquisition module 22. The specific structure of the fingerprint recognition circuit 32 is various. With continued reference to fig. 6, optionally, the fingerprint recognition circuit 32 comprises a second control switch T comprising a second control terminal 321, a second signal input terminal 322 and a second signal output terminal 323. The first electrode 221 is electrically connected to the second signal output terminal 323. The second control switch T may be a thin film transistor or other structures with a switching function.

Fig. 7 is a schematic structural diagram of another display panel according to an embodiment of the present invention. Referring to fig. 7, in the display panel, a plurality of light emitting cells 21 are further disposed in an opening area (not shown in fig. 7) of a base substrate 10; the light-emitting unit 21 further includes a fifth electrode 215, a light-emitting layer 214, and a sixth electrode 216 which are sequentially stacked; the fifth electrode 215 is positioned between the base substrate 10 and the light emitting layer 214, and the sixth electrode 216 covers the light emitting layer 215 and the pixel defining layer 12.

Optionally, the fifth electrode 215 is an anode and the sixth electrode 216 is a cathode; alternatively, the fifth electrode 215 is a cathode and the sixth electrode 216 is an anode.

The operation principle of the display panel fingerprint recognition will be described in detail with reference to fig. 6 and 7, taking as an example the case where the light emitting unit 21 is multiplexed as a fingerprint recognition light source.

The second control terminal 321 of the second control switch T is electrically connected to the control circuit Gate, and the second signal input terminal 322 is electrically connected to the signal line Data.

During the fingerprint recognition phase, the node H1 inputs a low voltage signal (e.g., a constant voltage signal having a magnitude of-5V), and the signal line Data inputs a high voltage signal (e.g., a constant voltage signal having a magnitude of 1.5V). The whole fingerprint identification stage comprises a preparation stage, a fingerprint signal acquisition stage and a fingerprint signal detection stage. In the preparation phase, the control circuit Gate controls the second control switch T of the fingerprint identification circuit 32 to be turned on, and the first capacitor C1 is charged until the charging of the first capacitor C1 is completed. In the fingerprint signal collection phase, the second control switch T of the fingerprint identification circuit 32 is controlled to be turned off by the control circuit Gate. When a user presses a finger against the display panel, light L1 emitted from the fingerprint recognition light source (i.e., the light emitting unit 21) is irradiated onto the finger and reflected on the surface of the finger fingerprint to form reflected light L2. The reflected light L2 formed by the reflection of the finger fingerprint is incident into the fingerprint signal collecting module 22, is received by the photodiode D, and forms a photocurrent, and the direction of the photocurrent is from the node H2 to the node H1, so that the potential of the node H2 changes. In the fingerprint signal detection stage, the potential variation of the node H2 can be directly detected, so as to determine the magnitude of the photocurrent.

Optionally, in the fingerprint signal detection stage, the control circuit Gate may be further used to control the second control switch T of the fingerprint identification circuit 32 to be turned on, at this time, a potential difference exists between two electrodes of the first capacitor C1, the first capacitor C1 is in a charging state, and the magnitude of the photocurrent is determined by detecting the amount of charge charged by the first capacitor C1.

With continued reference to fig. 7, since the ridges 41 pressed in the touch subject 40 (such as a finger) of the display panel are in contact with the display panel surface, and the valleys 42 are not in contact with the display panel surface, so that the reflectivity of the light rays impinging on the valleys 42 and the ridges 41 of the touch subject 40 is different, and further the intensity of the reflected light formed at the positions of the ridges 41 and the reflected light formed at the positions of the valleys 42 received by the fingerprint signal collection module 22 is different, so that the magnitudes of the photocurrents converted from the reflected light formed at the positions of the ridges 41 and the reflected light formed at the positions of the valleys 42 are different. Fingerprint identification can be carried out according to the magnitude of the photocurrent.

It should be noted that, if the fingerprint signal collecting module 22 includes the photodiode D and the first capacitor C1, since the photodiode D is mainly used for collecting the fingerprint signal light, "the fingerprint signal collecting module is located at any one of the following positions, between the pixel defining layer and the film packaging layer, on the side of the film packaging layer away from the pixel defining layer, and inside the film packaging layer" specifically includes: the photodiode D is located between the pixel defining layer and the thin film encapsulation layer, on a side of the thin film encapsulation layer facing away from the pixel defining layer, or inside the thin film encapsulation layer. The specific arrangement position of the first capacitor C1 is not limited in the present application. In actual arrangement, the first capacitor C1 is optionally arranged at the same position as or different from that of the photodiode D.

In practical implementation, the first capacitor C1 can be arranged in various ways. For example, two metal layers are added in the display panel to form the third electrode 223 and the fourth electrode 224 of the first capacitor C1, respectively, or at least one of the third electrode 223 and the fourth electrode 224 is shared with other structures in the display panel. The third electrode 223 is used in common with other structures of the display panel, but the present application is not limited thereto.

With continued reference to fig. 7, optionally, the sixth electrode 216 is multiplexed as the third electrode 223 of the fingerprint signal acquisition module 22 such that the sixth electrode 216 and the fourth electrode 224 together form a first capacitance C1. The advantage of setting up like this is, need not make sixth electrode 216 and third electrode 223 respectively, only need once etching process in the manufacturing process, need not to make the mask plate respectively to sixth electrode 216 and third electrode 223, has saved the cost, has reduced process quantity, has improved production efficiency. And this is advantageous in reducing the thickness of the display panel, compared to a scheme of adding a metal layer in the display panel to form the third electrode 223.

With reference to fig. 7, optionally, the first electrode 221 is multiplexed as the fourth electrode 224, which has the advantages that the first electrode 221 and the fourth electrode 224 do not need to be manufactured separately, only one etching process is needed in the manufacturing process, and no mask is needed to be manufactured for the first electrode 221 and the fourth electrode 224, so that the cost is saved, the number of manufacturing processes is reduced, and the production efficiency is improved. And this is advantageous to reduce the thickness of the display panel, compared to the solution of adding a metal layer in the display panel to form the fourth electrode 224.

Further, on the basis that the sixth electrode 216 is multiplexed as the third electrode 223 of the fingerprint signal acquisition module 22, the sixth electrode 216 and the first electrode 221 together form a first capacitance C1. The manufacturing process of independently manufacturing the first capacitor C can be omitted, and the manufacturing efficiency of the display panel is improved.

With continued reference to fig. 7, the display panel further includes a plurality of pixel circuits 31; the pixel circuit 31 is located between the fifth electrode 215 and the base substrate 10, and the fingerprint identification circuit 32 is located between the pixel defining layer 12 and the base substrate 10. The essence of this arrangement is that the plurality of fingerprint recognition circuits 32 and the plurality of pixel circuits 31 are formed in synchronization. Compared with the structure that the fingerprint identification circuit 32 and the pixel circuit 31 are sequentially manufactured and formed, and the fingerprint identification circuit 32 and the pixel circuit 31 form a laminated structure, the number of film layers of the display panel can be reduced, and the thickness of the display panel is reduced.

With continued reference to fig. 7, the display panel further includes a first metal layer M1 and a second metal layer M2 stacked and disposed in an insulating manner; the first metal layer M1 is located between the second metal layer M2 and the base substrate 10, and the second metal layer M2 is located between the first metal layer M1 and the pixel defining layer 12; the pixel circuit 31 includes a first control switch, and the fingerprint recognition circuit includes a second control switch T; the first control switch comprises a first control terminal 311, a first signal input terminal 312 and a first signal output terminal 313; the second control switch T includes a second control terminal 321, a second signal input terminal 322 and a second signal output terminal 323; the first electrode 221 is electrically connected to the second signal output terminal 323; the fifth electrode 215 is electrically connected to the first signal output terminal 313; the first control terminal 311 and the second control terminal 321 are both located in the first metal layer M1; the first signal input terminal 312, the first signal output terminal 313, the second signal input terminal 322 and the second signal output terminal 323 are all located on the second metal layer M2. The essence of the arrangement is that the first control switch and the second control switch T are synchronously manufactured and formed, a plurality of mask plates do not need to be manufactured on the first control switch and the second control switch T respectively, the cost is saved, the number of manufacturing procedures is reduced, and the production efficiency is improved.

The first control switch may be a thin film transistor or other structures with a switching function.

In the above technical solution, the thin film encapsulation layer 20 includes a plurality of organic layers and a plurality of inorganic layers. The respective film layers constituting the thin film encapsulation layer are alternately stacked in such a manner that an inorganic layer, an organic layer, an inorganic layer, and an organic layer … … are formed. The benefits of such an arrangement are mainly twofold: on one hand, the inorganic layer has better water and oxygen isolation capability, so that the water and oxygen corrosion resistance of the display panel can be improved, the light-emitting unit 21 is protected from being corroded, and the service life of the display panel is prolonged; on the other hand, considering that the inorganic layer and the inorganic layer are directly laminated to be used as a film packaging layer, because the bonding force between the inorganic layer and the inorganic layer is relatively large, stress is easy to accumulate along the extension direction of the inorganic layer during bending. If the stress applied to the display panel is large, a defect such as breakage is likely to occur. And the thin film packaging layer formed by alternately laminating the inorganic layer, the organic layer, the inorganic layer and the organic layer … … has little stress accumulation of the display panel along the extension direction of the inorganic layer when the display panel is bent due to small bonding force between the inorganic layer and the organic layer, and the display panel is not damaged due to small stress.

It should be noted that, with continuing reference to fig. 7, since the fingerprint identification circuit 32 is located between the pixel defining layer 12 and the substrate 10, in order to electrically connect the first electrode 221 with the fingerprint identification circuit 32, optionally, a fourth via S4 is provided on the pixel defining layer 12 to penetrate through the pixel defining layer 12 and the sixth electrode 216, and the first electrode 221 is electrically connected with the fingerprint identification circuit 32 through the fourth via S4. Further, in order that the signal transmitted by the first electrode 221 and the signal transmitted by the sixth electrode 216 do not interfere with each other, the material filling the fourth via S4 is electrically insulated from the sixth electrode 216. Optionally, the distance between the sixth electrode 216 and the material filling the fourth via S4 is d, d ≧ 5 μm. Setting d ≧ 5 μm can sufficiently reduce the degree to which the signal transmitted by the first electrode 221 and the signal transmitted by the sixth electrode 216 interfere with each other.

If the fingerprint signal collection module 22 is located between the pixel defining layer 12 and the thin film encapsulation layer 20, since the signals transmitted by the first electrode 221 and the sixth electrode 216 are different, in order to electrically insulate the first electrode 221 and the sixth electrode 216 from each other and avoid mutual interference between the signals transmitted by the first electrode 221 and the sixth electrode 216, optionally, the first electrode 221 and the sixth electrode 216 are located on the same film layer and are spaced apart from each other by a set distance. Referring to fig. 7, the display panel further includes a first insulating layer 13, the first insulating layer 13 being between the first electrode 221 and the sixth electrode 216; the display panel further includes a first via hole S1, the first via hole S1 penetrates the first insulating layer 13, and the second electrode 222 is electrically connected to the sixth electrode 216 through the first via hole S1. By additionally arranging the first insulating layer 13 between the first electrode 221 and the sixth electrode 216, the first electrode 221 and the sixth electrode 216 can be electrically insulated from each other, and mutual interference between the two electrodes can be avoided.

In actual arrangement, the material of the first insulating layer 13 may be an inorganic material or an organic material. Due to current fabrication process limitations, the minimum thickness at which inorganic layers can be fabricated is less than the minimum thickness at which organic layers can be fabricated. Therefore, the material of the first insulating layer 13 is an inorganic material, which is beneficial to the development trend of thinning the display panel. In addition, according to the formula

Where C' is the capacitance value of the first capacitor and ε is the dielectric permittivity, depending on the material of the dielectric. S is the facing area of the third electrode 223 (i.e., the sixth electrode 216) and the fourth electrode 224 (i.e., the first electrode 221), d' is the distance between the third electrode 223 and the fourth electrode 224, and k is a constant of the electrostatic force, which is a constant value. When the facing area S of the third electrode 223 and the fourth electrode 224 and the capacitance value C 'of the first capacitor are constant, the distance d' between the third electrode 223 and the fourth electrode 224 decreases as the dielectric constant ∈ increases. Since the dielectric constant of the inorganic material is greater than that of the organic material, and the first insulating layer 13 determines the third electrode 223 and the fourth electrode 223The distance d' between the electrodes 224. The first insulating layer 13 is made of an inorganic material, so that the first capacitor has a larger capacitance value C' when the thickness of the first insulating layer 13 is small, which is beneficial to complying with the development trend of thinning the display panel.

In addition, during actual manufacturing, in the process of forming the fingerprint signal collection module 22, multiple etching processes need to be performed, and the material of the first insulating layer 13 is an inorganic material, so that the first insulating layer 13 can play a role in etching blocking, and the sixth electrode 216 is prevented from being damaged by a subsequent etching process, which affects the manufacturing yield of the display panel.

On the basis of the above embodiments, the display panel further includes a touch electrode layer, the touch electrode layer is located on a side of the thin film encapsulation layer away from the pixel defining layer, and the touch electrode layer includes a plurality of touch electrodes insulated from each other to implement a touch function.

The touch electrode can be a self-capacitance touch electrode or a mutual capacitance touch electrode. This is not limited by the present application.

The working principle of the touch electrode will be described in detail below by taking a self-contained touch electrode as an example. In the self-capacitance display panel, each touch electrode corresponds to a determined coordinate position, and the touch electrodes respectively form capacitance with the ground. When a finger touches the self-capacitance display panel, the capacitance of the finger is superposed on the touch electrode touched by the finger, so that the capacitance to the ground of the touch electrode touched by the finger changes. The change of the signal of each touch electrode reflects the change of the capacitance of the touch electrode to the ground. The signal change condition of each touch electrode is detected to determine which specific touch electrode signal changes, and further the touch position of the finger can be determined according to the coordinate value corresponding to the touch electrode with the changed signal.

Fig. 8 is a schematic structural diagram of another display panel according to an embodiment of the present invention. Referring to fig. 8, if the fingerprint signal collection module is located on a side of the thin film encapsulation layer 20 away from the pixel defining layer 12, optionally, the first electrode 221 and the touch electrode 14 are located on the same layer. The advantage of setting up like this is, need not make first electrode 221 and touch electrode 14 respectively, only need once etching process in the manufacturing process, need not to make the mask plate respectively to first electrode 221 and touch electrode 14, saved the cost, reduced process quantity, improved production efficiency. And this is advantageous to reduce the thickness of the display panel, compared to a scheme of adding a metal layer in the display panel to form the first electrode 221.

Fig. 9 is a schematic structural diagram of another display panel according to an embodiment of the present invention. Referring to fig. 9, optionally, the display panel further includes a second insulating layer 15, a third metal layer M3, a second via hole S2, and a third via hole S3; the second insulating layer 15 is located between the sixth electrode 216 and the third metal layer M3, and the third metal layer M3 is located between the second insulating layer 15 and the thin film encapsulation layer 20; the third metal layer M3 includes a plurality of auxiliary connection blocks 225, the vertical projection of the auxiliary connection blocks 225 on the substrate base plate 10 being located in the non-opening area (not shown in fig. 9); the second via hole S2 penetrates through the thin film encapsulation layer 20, and the first electrode 221 is electrically connected with the auxiliary connection block 225 through the second via hole S2; the third via hole S3 penetrates through the second insulating layer 15 and the pixel defining layer 12, and the auxiliary connection block 225 is electrically connected to the second signal output terminal 323 through the third via hole S3. The essence of this arrangement is that the via hole for electrically connecting the first electrode 221 and the corresponding second signal output terminal 323 is formed by two etching processes, which can reduce the manufacturing difficulty of the display panel.

Optionally, the display panel further includes a fifth via S5, the fifth via S5 penetrates through the thin film encapsulation layer 20 and the second insulating layer 15, and the second electrode 222 is electrically connected to the sixth electrode 216 through the fifth via S5.

With continued reference to fig. 9, it is considered that, in practice, if the second through hole S2 and the fifth through hole S5 are required to penetrate through the thin film encapsulation layer 20, the encapsulation effect of the thin film encapsulation layer 20 may be affected, and the ability of the thin film encapsulation layer 20 to isolate water and oxygen may be weakened. Therefore, optionally, the display panel further comprises a protective layer 16: the protective layer 16 is located on a side of the fingerprint signal acquisition module 22 facing away from the film encapsulation layer 20, and the protective layer 16 covers the fingerprint signal acquisition module 22. The protective layer 16 can improve the encapsulation effect of the thin film encapsulation layer 20.

It should be noted that, in actual implementation, as shown in fig. 9, the protective layer 16 may only cover the fingerprint signal acquisition module 22. The protective layer 16 may also cover the fingerprint signal collecting module 22 and other areas (such as the touch electrodes 14, the area between adjacent touch electrodes 14, the area between the touch electrode 14 and the fingerprint signal collecting module 22, etc.) except the fingerprint signal collecting module 22. That is, the vertical projection of the protective layer 16 on the base substrate 10 completely coincides with the vertical projection of the thin film encapsulation layer 20 on the base substrate 10, or the vertical projection of the thin film encapsulation layer 20 on the base substrate 10 is located within the vertical projection of the protective layer 16 on the base substrate 10.

Fig. 10 is a schematic structural diagram of another display panel according to an embodiment of the present invention. Referring to fig. 10, alternatively, if the fingerprint signal collection module 22 is located inside the thin film encapsulation layer 20; the thin film encapsulation layer 20 includes a plurality of organic layers 202 and a plurality of inorganic layers 201 (in fig. 10, the thin film encapsulation layer 20 exemplarily includes one organic layer 202 and two inorganic layers 201), the inorganic layers 201 and the organic layers 202 are alternately stacked, and the fingerprint signal collection module 22 is located between the inorganic layers 201 and the organic layers 202 which are adjacently disposed. The advantage of this arrangement is that the via hole for electrically connecting the second electrode 222 and the sixth electrode 216 and the via hole for electrically connecting the first electrode 221 and the second signal output terminal 323 have less influence on the packaging effect of the thin film packaging layer 20 on the premise of improving the fingerprint identification accuracy of the display panel. And an additional insulating layer for electrically insulating the first electrode 221 and the sixth electrode 216 is not required, which is beneficial to reducing the thickness of the display panel.

With continued reference to fig. 10, optionally, the display panel further includes a fourth metal layer M4, the fourth metal layer M4 being located between the first metal layer M1 and the second metal layer M2; the pixel circuit 31 includes a second capacitance; the second capacitor includes a seventh electrode 317 and an eighth electrode 318, the seventh electrode 317 is located on the fourth metal layer M4, and the eighth electrode 318 is located on the first metal layer M1. The eighth electrode 318 is disposed on the first metal layer M1, that is, the eighth electrode 318, the first control end 311, and the second control end 321 are disposed on the same film layer, only one etching process is needed, and no mask plate needs to be respectively manufactured for the eighth electrode 318, the first control end 311, and the second control end 321, so that the cost is saved, the number of processes is reduced, and the production efficiency is improved. And this arrangement is advantageous for reducing the thickness of the display panel.

On the basis of the above technical solutions, it is considered that the flexible display panel needs to have higher bending resistance. Optionally, fig. 11 is a schematic structural diagram of another display panel provided in the embodiment of the present invention. Referring to fig. 11, the display panel further includes a third insulating layer 17 and a fourth insulating layer 18 stacked; the third insulating layer 17 is located between the fourth metal layer M4 and the fourth insulating layer 18, and the fourth insulating layer 18 is located between the third insulating layer 17 and the second metal layer M2; the material of the third insulating layer 17 is an inorganic material, and the material of the fourth insulating layer 18 is an organic material. The reason for this is that, when the pixel circuit 31 and the fingerprint identification circuit 32 are manufactured, it is necessary to perform patterning processing on a plurality of film layers (such as the first metal film layer M1 and the fourth metal layer M4) respectively, and the regions of the patterning processing of each film layer are different, so that the surface of the third insulating layer 17 facing away from the substrate base plate 20 is uneven after the third insulating layer 17 is formed and before the second metal layer M2 is formed. The surface of the third insulating layer 17 away from the substrate 20 can be filled by the fourth insulating layer 18, so as to perform a planarization function, thereby improving the bending resistance of the flexible display panel.

Based on the same purpose, the application also provides a display device. Fig. 12 is a schematic structural diagram of a display device according to an embodiment of the present invention, and referring to fig. 12, a display device 100 according to an embodiment of the present invention includes any one of the display panels 200 according to the above embodiments.

According to the embodiment of the invention, the fingerprint signal acquisition module is positioned at any one of the following positions, between the pixel limiting layer and the thin film packaging layer, on the side of the thin film packaging layer departing from the pixel limiting layer and inside the thin film packaging layer, so that the effect of fingerprint identification precision of the display panel can be improved. In addition, among this application implanting display panel with fingerprint identification module, realized the display panel technique of integrated light sense touch-control unit (accell) for outside the panel possesses fingerprint identification function under the screen, have the slimming advantage concurrently, display panel is more frivolous, and preparation simple process is favorable to promoting display panel's core competitiveness, makes huge contribution for fingerprint identification technique under the screen.

The display device 100 may be a mobile phone, a tablet computer, a smart wearable device, or an electronic photo frame.

It is to be noted that the foregoing is only illustrative of the preferred embodiments of the present invention and the technical principles employed. It will be understood by those skilled in the art that the present invention is not limited to the particular embodiments described herein, but is capable of various obvious modifications, rearrangements, combinations and substitutions as will now become apparent to those skilled in the art without departing from the scope of the invention. Therefore, although the present invention has been described in greater detail by the above embodiments, the present invention is not limited to the above embodiments, and may include other equivalent embodiments without departing from the spirit of the present invention, and the scope of the present invention is determined by the scope of the appended claims.

Claims

1. A display panel, comprising:

the fingerprint signal acquisition module is positioned at any one of the following positions, namely between the pixel limiting layer and the thin film packaging layer, on one side of the thin film packaging layer, which is far away from the pixel limiting layer, and inside the thin film packaging layer;

the display panel further comprises a plurality of fingerprint identification circuits;

the fingerprint signal acquisition module comprises a light sensing diode and a first capacitor, the light sensing diode comprises a first electrode and a second electrode, and the second electrode is positioned on one side of the first electrode, which is far away from the pixel limiting layer;

the first capacitor comprises a third electrode and a fourth electrode, the second electrode is electrically connected with the third electrode, and the first electrode and the fourth electrode are electrically connected with the fingerprint identification circuit;

a plurality of light-emitting units are arranged in the opening area of the substrate base plate;

the light-emitting unit further comprises a fifth electrode, a light-emitting layer and a sixth electrode which are sequentially stacked; the fifth electrode is positioned between the substrate base plate and the light-emitting layer, and the sixth electrode covers the light-emitting layer and the pixel defining layer;

the sixth electrode is multiplexed as a third electrode of the fingerprint signal acquisition module, so that the sixth electrode and the fourth electrode jointly form the first capacitor.

2. The display panel according to claim 1,

the first electrode is multiplexed as the fourth electrode, and the sixth electrode and the first electrode jointly form the first capacitor.

3. The display panel according to claim 1, further comprising a plurality of pixel circuits;

the pixel circuit is located between the fifth electrode and the substrate base plate, and the fingerprint identification circuit is located between the pixel defining layer and the substrate base plate.

4. The display panel according to claim 3,

the display panel further comprises a first metal layer and a second metal layer which are stacked and arranged in an insulating mode; the first metal layer is located between the second metal layer and the substrate base plate, and the second metal layer is located between the first metal layer and the pixel defining layer;

the pixel circuit comprises a first control switch, and the fingerprint identification circuit comprises a second control switch;

the first control switch comprises a first control end, a first signal input end and a first signal output end; the second control switch comprises a second control end, a second signal input end and a second signal output end;

the first electrode is electrically connected with the second signal output end; the fifth electrode is electrically connected with the first signal output end;

the first control end and the second control end are both positioned on the first metal layer; the first signal input end, the first signal output end, the second signal input end and the second signal output end are all located on the second metal layer.

5. The display panel according to claim 3,

the fingerprint signal acquisition module is positioned between the pixel limiting layer and the thin film packaging layer, and the display panel further comprises a first insulating layer positioned between the first electrode and the sixth electrode;

the display panel further comprises a first via hole, the first via hole penetrates through the first insulating layer, and the second electrode is electrically connected with the sixth electrode through the first via hole.

6. The display panel according to claim 5,

the material of the first insulating layer is an inorganic material.

7. The display panel according to claim 4,

the display panel further comprises a touch electrode layer, the touch electrode layer is located on one side, away from the pixel limiting layer, of the thin film packaging layer, and the touch electrode layer comprises a plurality of touch electrodes which are arranged in an insulated mode, so that a touch function is achieved.

8. The display panel according to claim 7,

the fingerprint signal acquisition module is located on one side, away from the pixel limiting layer, of the film packaging layer, and the first electrode and the touch electrode are located on the same layer.

9. The display panel according to claim 8,

the second insulating layer, the third metal layer, the second via hole and the third via hole are also included;

the second insulating layer is positioned between the sixth electrode and a third metal layer, and the third metal layer is positioned between the second insulating layer and the thin film packaging layer;

the third metal layer comprises a plurality of auxiliary connecting blocks, and the vertical projection of the auxiliary connecting blocks on the substrate base plate is positioned in the non-opening area;

the second through hole penetrates through the thin film packaging layer, and the first electrode is electrically connected with the auxiliary connecting block through the second through hole;

the third via hole penetrates the second insulating layer and the pixel defining layer, and the auxiliary connection block is electrically connected to the second signal output terminal through the third via hole.

10. The display panel according to claim 9, further comprising a protective layer:

the protective layer is located the fingerprint signal acquisition module deviates from one side of film packaging layer, the protective layer covers fingerprint signal acquisition module.

11. The display panel according to claim 1,

the fingerprint signal acquisition module is positioned in the thin film packaging layer;

the film packaging layer comprises a plurality of organic layers and a plurality of inorganic layers, the inorganic layers and the organic layers are alternately stacked, and the fingerprint signal acquisition module is positioned between the inorganic layers and the organic layers which are adjacently arranged.

12. The display panel according to claim 4, further comprising a fourth metal layer between the first metal layer and the second metal layer;

the pixel circuit includes a second capacitance; the second capacitor comprises a seventh electrode and an eighth electrode, the seventh electrode is located on the fourth metal layer, and the eighth electrode is located on the first metal layer.

13. The display panel according to claim 12,

the display panel further comprises a third insulating layer and a fourth insulating layer which are stacked;

the third insulating layer is positioned between the fourth metal layer and the fourth insulating layer, and the fourth insulating layer is positioned between the third insulating layer and the second metal layer;

the third insulating layer is made of an inorganic material, and the fourth insulating layer is made of an organic material.

14. A display device characterized by comprising the display panel according to any one of claims 1 to 13.