CN111221165B

CN111221165B - Display panel and display device

Info

Publication number: CN111221165B
Application number: CN202010027690.5A
Authority: CN
Inventors: 陈建友; 陈健; 钟彩娇; 周婷; 沈柏平
Original assignee: Xiamen Tianma Microelectronics Co Ltd
Current assignee: Xiamen Tianma Microelectronics Co Ltd
Priority date: 2020-01-10
Filing date: 2020-01-10
Publication date: 2022-09-09
Anticipated expiration: 2040-01-10
Also published as: CN111221165A

Abstract

The invention discloses a display panel and a display device. The display panel includes: an array substrate; a color film substrate; the liquid crystal layer is clamped between the array substrate and the color film substrate; and the photosensitive units are arranged on the array substrate, the photosensitive surface of each photosensitive unit faces the color film substrate, the color film substrate comprises a black matrix layer, the black matrix layer comprises a plurality of first openings, a slit unit and a first light filtering unit covering the slit unit are arranged in each first opening, each slit unit comprises two slits which enable light to penetrate through and interfere with each other, and the photosensitive units can receive the light which penetrates through the first light filtering unit and the slit unit. According to the display panel provided by the embodiment of the invention, the light rays passing through the first filtering unit and the slit unit can form the light intensity strengthening areas and the light intensity counteracting areas which are arranged alternately on the plane where the light sensing surface is located. The light sensing units receive the light rays passing through the first light filtering units and the slit units, and information crosstalk between the adjacent light sensing units can be reduced.

Description

Display panel and display device

Technical Field

The invention relates to the field of display, in particular to a display panel and a display device.

Background

The display panel integrated fingerprint identification technology is a panel integrated technology which provides fingerprint identification capability without reducing the effective display area of the display panel. Existing display panels typically incorporate an optical fingerprint recognition unit. The light emitted from the display panel is reflected by the surface of the finger and enters the display panel again to be received by the fingerprint identification unit. The fingerprint identification unit can generate different identification information according to the difference of the valleys and ridges of the finger lines to light reflection, so that different finger line information can be identified.

In the prior art, the number of fingerprint identification units integrated on the display panel is usually multiple, and adjacent photosensitive units are easy to cross talk with each other.

Disclosure of Invention

The invention provides a display panel and a display device, which can reduce the crosstalk phenomenon between adjacent integrated photosensitive units.

In one aspect, an embodiment of the present invention provides a display panel, which includes: an array substrate; a color film substrate; the liquid crystal layer is clamped between the array substrate and the color film substrate; and the photosensitive units are arranged on the array substrate, the photosensitive surface of each photosensitive unit faces the color film substrate, the color film substrate comprises a black matrix layer, the black matrix layer comprises a plurality of first openings, a slit unit and a first light filtering unit covering the slit unit are arranged in each first opening, each slit unit comprises two slits which enable light to penetrate through and interfere with each other, and the photosensitive units can receive the light which penetrates through the first light filtering unit and the slit unit.

In another aspect, an embodiment of the present invention provides a display device, which includes the display panel according to any one of the foregoing embodiments of the one aspect of the present invention and a backlight module disposed opposite to the display panel.

According to the display panel provided by the embodiment of the invention, the array substrate is provided with the photosensitive unit, so that the display panel has light sensing performance. The display panel of the embodiment of the invention also comprises a first filtering unit and a slit unit, so that light rays passing through the first filtering unit and the slit unit can form interference fringes, namely, light intensity strengthening areas and light intensity counteracting areas which are arranged alternately can be formed on the plane where the photosensitive surface is located. The light sensing units receive the light rays passing through the first light filtering units and the slit units, and information crosstalk between the adjacent light sensing units can be reduced.

Drawings

Other features, objects and advantages of the invention will become apparent from the following detailed description of non-limiting embodiments thereof, when read in conjunction with the accompanying drawings, in which like reference characters designate the same or similar parts throughout the figures thereof, and which are not to scale.

FIG. 1 is a schematic top view of a display panel according to an embodiment of the present invention;

FIG. 2 is a schematic cross-sectional view taken along line B-B of FIG. 1;

fig. 3 is a schematic cross-sectional view illustrating interference fringes formed by one of the slit units SU of the display panel according to an embodiment of the present invention;

fig. 4 is a schematic cross-sectional view illustrating interference fringes formed by another adjacent slit unit SU of the display panel according to an embodiment of the present invention;

FIG. 5 is an enlarged partial schematic view of region C of FIG. 2;

FIG. 6 is a schematic top view of a pixel unit of a display panel according to an embodiment of the present invention;

FIG. 7 is an enlarged partial schematic view of region D of FIG. 6;

FIG. 8 is an enlarged view of a portion of the structure of the region D in FIG. 6 after being hidden;

fig. 9 is a schematic cross-sectional view of a display device according to an embodiment of the present invention.

Detailed Description

Features and exemplary embodiments of various aspects of the present invention will be described in detail below, and in order to make objects, technical solutions and advantages of the present invention more apparent, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not to be construed as limiting the invention. It will be apparent to one skilled in the art that the present invention may be practiced without some of these specific details. The following description of the embodiments is merely intended to provide a better understanding of the present invention by illustrating examples of the present invention.

It should be noted that, in this document, relational terms such as first and second, and the like are used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions.

It will be understood that when a layer, region or layer is referred to as being "on" or "over" another layer, region or layer in describing the structure of the component, it can be directly on the other layer, region or layer or intervening layers or regions may also be present. Also, if the component is turned over, one layer or region may be "under" or "beneath" another layer or region.

Embodiments of the present invention provide a Display panel, which may be a Liquid Crystal Display (LCD) panel, and the Display panel of the embodiments of the present invention may be presented in various forms, some examples of which will be described below.

Fig. 1 is a schematic top view of a display panel according to an embodiment of the invention, and fig. 2 is a schematic cross-sectional view along the direction B-B in fig. 1. The display panel 100 has a display area AA and a non-display area NA surrounding at least a portion of the periphery of the display area AA. The display panel 100 includes a plurality of pixel units PU arranged in the display area AA, each pixel unit PU including a plurality of sub-pixels PX.

The plurality of sub-pixels PX are arranged in an array of rows and columns in the display area AA, for example. Although not shown in the drawings, the display panel 100 may include a plurality of scan lines each extending in a row direction of the arrangement structure of the plurality of sub-pixels PX, and a plurality of data lines each extending in a column direction of the arrangement structure of the plurality of sub-pixels PX. Each row of the sub-pixels PX are connected to the gate driving circuit through a corresponding one of the scan lines, so that the gate signals of the gate driving circuit can be received. Each column of the sub-pixels PX is connected to the data driving circuit through a corresponding one of the data lines, so as to be capable of receiving a data signal (e.g., a gray scale voltage signal) from the data driving circuit.

The display panel 100 includes an array substrate 110, a color film substrate 120, a liquid crystal layer 130, and a plurality of photosensitive units 140. The color filter substrate 120 is disposed opposite to the array substrate 110. The liquid crystal layer 130 is sandwiched between the array substrate 110 and the color filter substrate 120. The plurality of light sensing units 140 are disposed on the array substrate 110, and a light sensing surface 140a of each light sensing unit 140 faces the color filter substrate 120.

In some embodiments, the array substrate 110 includes a first substrate 111, a device layer 112 located on a side of the first substrate 111 facing the color filter substrate 120, and a plurality of pixel electrodes 113 located on a side of the device layer 112 facing the color filter substrate 120. The plurality of pixel electrodes 113 are arranged in an array, and orthographic projections of the plurality of pixel electrodes 113 on the first substrate 111 are overlapped with orthographic projections of the plurality of sub-pixels PX on the first substrate 111 in a one-to-one correspondence manner. The array substrate 110 may include a thin film transistor T1 formed in the device layer 112, the gate of the thin film transistor T1 is connected to the corresponding scan line, and the thin film transistor T1 further has a source electrode and a drain electrode, wherein one of the source electrode and the drain electrode is connected to the corresponding data line, and the other of the source electrode and the drain electrode is connected to the pixel electrode 113.

In some embodiments, the plurality of photosensitive units 140 are embedded in the device layer 112 of the array substrate 110. In fig. 2, the photosensitive surface 140a of the photosensitive unit 140 is substantially flush with the surface of the device layer 112 facing the color filter substrate 120, however, the position of the photosensitive surface 140a of the photosensitive unit 140 may not be limited thereto, for example, in some other embodiments, the photosensitive surface 140a of the photosensitive unit 140 is located between the surface of the device layer 112 facing the color filter substrate 120 and the first substrate 111.

In this embodiment, the color filter substrate 120 includes a second substrate 121 and a black matrix layer 122 located on a side of the second substrate 121 facing the array substrate 110. The black matrix layer 122 includes a plurality of first openings K1, and the first openings K1 are provided therein with slit units SU and first filter units 151 covering the slit units SU. Each slit unit SU includes two slits 152 that allow light to pass through and interfere with each other, and the light sensing unit 140 can receive the light passing through the first filter unit 151 and the slit unit SU.

According to the display panel 100 of the embodiment of the invention, the array substrate 110 is provided with the photosensitive unit 140, so that the display panel 100 has a light sensing performance. The display panel 100 of the embodiment of the invention further includes the first filtering unit 151 and the slit unit SU, so that light passing through the first filtering unit 151 and the slit unit SU can form monochromatic bright and dark interference fringes, that is, light intensity strengthening regions and light intensity cancelling regions arranged alternately can be formed on the plane where the photosensitive surface 140a is located. The light sensing units 140 receive the light passing through the first filter unit 151 and the slit unit SU, and information crosstalk between adjacent light sensing units 140 can be reduced.

In some embodiments, the plurality of photosites 140 correspond to a plurality of groups of slot units SU, where each group includes one photosite 140 and one slot unit SU corresponding to each other. Each slit unit SU allows the transmitted light to interfere with each other to form interference fringes at the plane where the photosensitive surface 140a is located.

Fig. 3 is a schematic cross-sectional view illustrating interference fringes formed by one of the slit units SU of the display panel according to an embodiment of the present invention, and fig. 4 is a schematic cross-sectional view illustrating interference fringes formed by another adjacent slit unit SU of the display panel according to an embodiment of the present invention, wherein in order to clearly illustrate the interference fringes formed at the plane where the photosensitive surface 140a is located, a portion of the structure of the array substrate 110 and the liquid crystal layer 130 are shown in fig. 3 and 4.

In fig. 3 and 4, for the sake of easy distinction, reference numerals for the left photosensitive unit and the left slit unit are referred to as the photosensitive unit 140 and the slit unit SU, and reference numerals for the right photosensitive unit and the right slit unit are referred to as the photosensitive unit 140 'and the slit unit SU'. The plurality of photosensitive units correspond to the plurality of slit unit groups, wherein the left photosensitive unit 140 and the left slit unit SU correspond to each other and form a first group, the right photosensitive unit 140 ' and the right slit unit SU ' correspond to each other and form a second group, and the photosensitive unit 140 of the first group is adjacent to the photosensitive unit 140 ' of the second group.

Fig. 3 is a schematic diagram of interference fringes formed by the slit units SU of the first group, which enable transmitted light rays to interfere with each other to form an interference fringe IF on the plane where the photosensitive surface 140a is located. The interference fringes IF include a plurality of light fringe areas LS and a plurality of dark fringe areas DS, wherein the light fringe areas LS are alternated with the dark fringe areas DS.

Fig. 4 is a schematic diagram of interference fringes formed by the slit units SU 'of the second group, which allow transmitted light rays to interfere with each other to form interference fringes IF' on a plane where the photosensitive surface 140a is located. The interference fringes IF ' include a plurality of light fringe areas LS ' and a plurality of dark fringe areas DS ', wherein the light fringe areas LS ' are alternated with the dark fringe areas DS '.

In the present embodiment, each photosensitive unit is located in a bright fringe area of interference fringes formed by the corresponding slit unit, and is located in a dark fringe area of interference fringes formed by the adjacent set of slit units.

In some embodiments, the size of each bright stripe region (or each stripe region) in the direction perpendicular to the extending direction of the slit 152 is 0.9 times to 1.1 times the size of the photosensitive surface 140a of each photosensitive unit 140 in the direction perpendicular to the extending direction of the slit 152. For example, the size of each bright stripe region (or each stripe region) in the direction perpendicular to the extending direction of the slit 152 is equal to the size of the photosensitive surface 140a of each photosensitive unit 140 in the direction perpendicular to the extending direction of the slit 152.

For the light sensing units 140 of the first group, as shown in fig. 3, the light sensing units 140 of the first group are located in the bright fringe region LS of the interference fringes IF formed by the corresponding slit units SU (slit units SU of the first group). Also, as shown in fig. 4, the light sensing unit 140 of the first group is located in the dark fringe region DS 'of the interference fringe IF' formed by the slit unit SU 'of the adjacent group (the slit unit SU' of the second group).

Therefore, for the light sensing units 140 of the first group, the slit units SU corresponding to the light sensing units themselves interfere with light to form light intensity enhanced regions, so that the light passing through the corresponding slit units SU can be received to obtain corresponding light information. Meanwhile, the light sensing units 140 of the first group are located in the light intensity cancellation region formed by the interference of the adjacent second group of slit units SU 'on the light, so that the light passing through the adjacent second group of slit units SU' is hardly received, and the interference of the light passing through the adjacent second group of slit units SU 'on the light sensing units 140 is hardly obtained by obtaining the light information passing through the adjacent second group of slit units SU'.

Similarly, for the second group of light-sensing units 140 ', as shown in fig. 4, the second group of light-sensing units 140 ' are located in the bright fringe area LS ' of the interference fringe IF ' formed by the corresponding slit unit SU ' (the slit unit SU of the second group). Also, as shown in fig. 3, the light sensing units 140' of the second group are located in the dark fringe region DS of the interference fringes IF formed by the adjacent groups of slit units SU (slit units SU of the first group).

Therefore, for the light sensing units 140 'of the second group, the light sensing units SU' corresponding to the light sensing units 140 'interfere with the light to form the light intensity enhancing region, so that the light passing through the corresponding slit units SU' can be received, and the corresponding light information can be obtained. Meanwhile, the light sensing units 140 'of the second group are located in the light intensity cancellation region formed by the interference of the adjacent first group of slit units SU on the light, so that the light passing through the adjacent first group of slit units SU is hardly received, and the interference of the light passing through the adjacent first group of slit units SU on the light sensing units 140' is avoided by obtaining the light information passing through the adjacent first group of slit units SU.

As shown in fig. 3, for an interference fringe IF formed by the light interference of the slit units SU of the first group, the corresponding group of the light-sensing units 140 (the light-sensing units 140 of the first group) is located in the bright fringe area LS of the interference fringe IF, and at the same time, the adjacent group of the light-sensing units 140 '(the light-sensing units 140' of the second group) is located in the dark fringe area DS of the interference fringe IF. The sum of the number of the bright stripe regions LS and the number of the dark stripe regions DS between the photosensitive units (e.g., the photosensitive units 140 and 140') adjacent to each other is an even number, and by controlling the pitch of the adjacent photosensitive units, crosstalk between the adjacent photosensitive units can be reduced, and the sensitivity of the photosensitive units can be improved.

Here, each of the light sensing units 140 is located in the light fringe region LS corresponding to the interference fringe IF formed by the slit units SU, and is located in the dark fringe region DS corresponding to the interference fringe IF formed by the adjacent group of slit units SU.

Fig. 5 is a partially enlarged schematic view of the region C in fig. 2. Fig. 6 is a schematic top view of one pixel unit of the display panel according to an embodiment of the invention, fig. 7 is a schematic partial enlarged view of a region D in fig. 6, and fig. 8 is a schematic partial enlarged view of the region D in fig. 6 after a portion of the structure is hidden, where fig. 8 shows the second substrate 121 and the first filtering unit 151 hidden.

In some embodiments, each slit unit SU further includes a light blocking layer 153. The light blocking layer 153 is disposed around the outline of each slit 152 in a cross section perpendicular to the thickness direction of the display panel 100. Wherein the light blocking layer 153 is connected to the black matrix layer 122 at least at a portion of the outer circumference in a direction perpendicular to the thickness direction of the display panel 100.

In some embodiments, the projection of the slit 152 on the plane where the photosensitive surface 140a is located is in the shape of a bar, an ellipse, a rectangle, a square, or a gourd. For example, the projection of the slit 152 on the plane where the photosensitive surface 140a is located is rectangular. The size and shape of the slit 152 may be appropriately set according to the interference principle of light.

As shown in fig. 8, in some embodiments, the width W1 of each slit 152 is less than or equal to 0.5 microns. In the present embodiment, the slit width W1 of each slit 152 is 0.5 μm.

In fig. 8, the outline of the orthographic projection of the light-sensing surface 140a of the light-sensing unit 140 on the plane of the slit unit SU is shown by a dotted line. In some embodiments, the length W2 of each slit 152 in the extending direction thereof is equal to or greater than the dimension W3 of the light-sensing surface 140a of each light-sensing unit 140 in the extending direction of the slit 152.

In some embodiments, the spacing d between two slits 152 in each slit unit SU is 1.5 to 3 micrometers.

In some embodiments, the spacing between two slots 152 in each slot unit SU satisfies the following condition:

0.9(I·λ/L)≦d≦1.1(I·λ/L)

where d is the distance between two slits 152 in each slit unit SU; i is the distance from the slit unit SU to the plane where the photosensitive surface 140a is located; λ is the wavelength of the light transmitted by the first filter 151; l is a dimension of the light sensing surface 140a of each light sensing unit 140 in a direction perpendicular to the extending direction of the slit 152.

In the present embodiment, the size of the photosensitive surface 140a of each photosensitive unit 140 in the direction perpendicular to the extending direction of the slit 152 is 4 to 5 micrometers, for example, 5 micrometers. The distance from the slit unit SU to the plane where the light-sensing surface 140a is located is 20 micrometers. The first filtering unit 151 is a green first filtering unit 151. The pitch between the two slits 152 in each slit unit SU is 1.8 to 2.2 micrometers, for example, the pitch between the two slits 152 in each slit unit SU is 2 micrometers. When the distance between two slits 152 in each slit unit SU is 2 micrometers, the width of a bright fringe region (or a dark fringe region) of an interference fringe formed by light passing through the slit unit SU on the plane where the photosensitive surface 140a is located is 5 micrometers, which is equal to the width of the photosensitive surface 140a of the photosensitive unit 140, so that the two fringe regions can be accurately aligned with the photosensitive surface 140a of the photosensitive unit 140, and the accuracy of the photosensitive unit 140 in acquiring light information is improved. The width of the bright stripe region (or the dark stripe region) and the width of the photosensitive surface 140a respectively refer to the dimension of the bright stripe region (or the dark stripe region) in the direction perpendicular to the extending direction of the slit 152 and the dimension of the photosensitive surface 140a in the direction perpendicular to the extending direction of the slit 152.

With continued reference to fig. 2 and 5, in some embodiments, the black matrix layer 122 further includes a plurality of second openings K2. The color filter substrate 120 further includes a second filter unit 123 disposed in the second opening K2, and light passing through the liquid crystal layer 130 can be transmitted outward through the second filter unit 123. The positions of the plurality of second filter units 123 correspond to the positions of the plurality of sub-pixels PX one-to-one, that is, the plurality of second filter units 123 are arranged in an array, and the orthographic projections of the plurality of second filter units 123 on the first substrate 111 are overlapped with the orthographic projections of the plurality of sub-pixels PX on the first substrate 111 in a one-to-one correspondence manner. The second filter units 123 may be divided into a plurality of types according to colors, and in one example, the plurality of second filter units 123 may include a red second filter unit 123, a green second filter unit 123, and a blue second filter unit 123 to allow red light to pass, green light to pass, and blue light to pass, respectively.

In some embodiments, the total thickness of the light blocking layer 153 and the first filtering unit 151 is equal to or less than the thickness of the second filtering unit 123. For example, the thickness of the second filtering unit 123 in the direction perpendicular to the second substrate 121 is 2.7 micrometers, and the total thickness of the light blocking layer 153 and the first filtering unit 151 in the direction perpendicular to the second substrate 121 is 2.7 micrometers or less.

In some embodiments, the first filtering units 151 in the plurality of first openings K1 are all filtering units of the same color. In one example, the first filtering units 151 in the plurality of first openings K1 are all green first filtering units 151, so as to allow green light to pass through.

As described above, the array substrate 110 includes the first substrate 111, the device layer 112 located on the side of the first substrate 111 facing the color filter substrate 120, and the plurality of pixel electrodes 113 located on the side of the device layer 112 facing the color filter substrate 120. The array substrate 110 includes a thin film transistor T1 formed in the device layer 112, and the thin film transistor T1 is connected to the pixel electrode 113. The plurality of light sensing units 140 are embedded in the device layer 112 of the array substrate 110.

In some embodiments, the color filter substrate 120 includes a second substrate 121, a black matrix layer 122, a second filtering unit 123, a planarization layer 124, and a common electrode 125. The black matrix layer 122 is located on the second substrate 121 on a side facing the array substrate 110. The black matrix layer 122 includes a second opening K2, and the second filter unit 123 is disposed in the second opening K2. The planarization layer 124 is located on the side of the black matrix layer 122 facing the array substrate 110, and covers the black matrix layer 122 and the second filter unit 123. The common electrode 125 is located on the side of the planarization layer 124 facing the array substrate 110.

The first filter unit 151 and the slit unit SU may be embedded in the color filter substrate 120, the black matrix layer 122 includes a first opening K1, the first filter unit 151 and the slit unit SU are disposed in the first opening K1, the slit unit SU is located on the side of the first filter unit 151 facing the array substrate 110, and the planarization layer 124 further covers the first filter unit 151 and the slit unit SU.

In some embodiments, the display panel 100 may further include a first alignment film and a first polarizer disposed on the array substrate 110, and a second alignment film and a second polarizer disposed on the color film substrate 120. The first alignment film and the second alignment film contact opposite surfaces of the liquid crystal layer 130, respectively. The rubbing direction of the first alignment film is opposite to that of the second alignment film, or has a predetermined angle. The transmission axis direction of the polarizer of the first polarizer is vertical to the transmission axis direction of the polarizer of the second polarizer.

The first substrate 111 and the second substrate 121 are transparent substrates, for example, glass substrates. The pixel electrode 113 and the common electrode 125 are both transparent electrodes, and are formed of a transparent conductive material such as ITO (Indium Tin Oxide).

Taking the example where the thin film transistor T1 is a top gate structure, the thin film transistor T1 includes a gate electrode on the first substrate 111, a gate insulating layer on the gate electrode, a semiconductor layer on the gate insulating layer, and a source electrode and a drain electrode in contact with the semiconductor layer on both sides of the gate electrode, respectively. The gate is a single layer or a stack of doped polysilicon, metal or alloy. The gate insulating layer is made of, for example, silicon oxide or silicon nitride. The semiconductor layer may be made of amorphous Silicon (α -Si), Low Temperature Polysilicon (LTPS), or the like. The structure of the thin film transistor T1 may not be limited to the above example, for example, in other embodiments, the thin film transistor T1 may also be a bottom gate structure.

When the thin film transistor T1 is turned on, a data signal (e.g., a gray scale voltage signal) is applied to the pixel electrode 113 through the thin film transistor T1. The common electrode 125 is grounded or a bias electric field is generated between the common electrode and the pixel electrode 113, so that liquid crystal molecules in the liquid crystal layer 130 are rotationally switched between the common electrode and the pixel electrode, and thus the sub-pixel PX is switched between a black state and a white state, so that the display panel 100 realizes display.

The photosensitive unit 140 may include a photodiode, and in one example, the photodiode includes a first conductive type semiconductor layer and a second conductive type semiconductor layer, wherein the first conductive type semiconductor layer is located on the side of the first substrate 111 facing the color filter substrate 120, and the second conductive type semiconductor layer is located on the side of the first conductive type semiconductor layer facing the color filter substrate 120. One of the first conductive type semiconductor layer and the second conductive type semiconductor layer is an N-type semiconductor layer, and the other is a P-type semiconductor layer. In some examples, the photodiode may further include an intrinsic semiconductor layer interposed between the first conductive type semiconductor layer and the second conductive type semiconductor layer. The first conductive type semiconductor layer, the second conductive type semiconductor layer, and the intrinsic semiconductor layer may be formed of amorphous silicon or polycrystalline silicon, respectively, by doping. When light irradiates the photosensitive diode, micro current can be generated in the photosensitive diode, so that an optical signal is converted into an electric signal.

In some embodiments, the light sensing unit 140 is an optical fingerprint recognition unit, thereby enabling fingerprint recognition. During fingerprint recognition, light emitted from the display panel 100 is reflected by the surface of the finger and enters the display panel 100, and is received by the light sensing unit 140 through the first filter unit 151 and the slit unit SU. The photosensitive unit 140 can generate different identification information according to the difference between the valley and the ridge of the finger print to the reflection of light, so that different finger print information can be identified.

According to the display panel 100 of the embodiment of the invention, the light passing through the first filtering unit 151 and the slit unit SU can form monochromatic bright and dark interference fringes, i.e., alternately arranged strong light intensity regions and strong light intensity cancellation regions can be formed on the plane where the photosensitive surface 140a is located. The light sensing units 140 receive the light passing through the first filter unit 151 and the slit unit SU, and information crosstalk between adjacent light sensing units 140 can be reduced.

An embodiment of the invention further provides a display device, and fig. 9 is a schematic cross-sectional view of the display device according to the embodiment of the invention. The display device 1000 may include the display panel 100 according to any of the embodiments and the backlight module 200 disposed opposite to the display panel 100. The light emitted from the backlight assembly 200 can propagate outward through the display panel 100.

In the display device 1000, the backlight module 200 includes a housing 210, a Light Guide Plate (LGP) 220, a Reflector 230 and a multi-layer optical film 240. The light guide plate 220, the reflective sheet 230, and the multilayer optical film 240 are located within the housing 210. The light guide plate 220 has a light emitting surface facing the display panel 100. The reflective sheet 230 is disposed on a side of the light guide plate 220 facing away from the display panel 100, and the multilayer optical film 240 is disposed on a side of the light guide plate 220 facing the display panel 100.

The multilayer optical Film 240 may include a diffusion sheet (Diffuser), a prism sheet (BEF), and the like. In one example, the multi-layer optical film 240 includes a first diffusion sheet, a first prism sheet, a second prism sheet, and a second diffusion sheet stacked in sequence from the light guide plate 220 toward the display panel 100.

Although not shown in the drawings, the backlight module 200 further includes a light source assembly, such as an LED light source assembly. In some embodiments, the light source assembly is a side light type, and the light source assembly is disposed at the side of the light guide plate 220. In some embodiments, the light source assembly is a direct-type light source assembly disposed on a side of the light guide plate 220 facing away from the display panel 100.

In the display device 1000, the display panel 100 includes an array substrate 110, a color film substrate 120, a liquid crystal layer 130, and a plurality of photosensitive units 140. The color filter substrate 120 is disposed opposite to the array substrate 110. The liquid crystal layer 130 is sandwiched between the array substrate 110 and the color filter substrate 120. The plurality of photosensitive units 140 are disposed on the array substrate 110, and a photosensitive surface 140a of each photosensitive unit 140 faces the color filter substrate 120.

In this embodiment, the color filter substrate 120 includes a black matrix layer 122. The black matrix layer 122 includes a plurality of first openings K1, and the first openings K1 are provided therein with slit units SU and first filter units 151 covering the slit units SU. Each slit unit SU includes two slits 152 that allow light to pass through and interfere with each other, and the light sensing unit 140 can receive the light passing through the first filter unit 151 and the slit unit SU.

According to the display device 1000 of the embodiment of the invention, the display panel 100 includes the light sensing unit 140 disposed on the array substrate 110, so that the display panel 100 has a light sensing performance. The display panel 100 further includes a first filtering unit 151 and a slit unit SU disposed on the color film substrate 120, so that light passing through the first filtering unit 151 and the slit unit SU can form monochromatic bright and dark interference fringes, i.e., light intensity strengthening regions and light intensity cancelling regions alternately arranged on a plane where the photosensitive surface 140a is located. The light sensing units 140 receive the light passing through the first filter unit 151 and the slit unit SU, and information crosstalk between adjacent light sensing units 140 can be reduced.

In accordance with the above-described embodiments of the present invention, these embodiments are not intended to be exhaustive or to limit the invention to the precise embodiments disclosed. Obviously, many modifications and variations are possible in light of the above teaching. The embodiments were chosen and described in order to best explain the principles of the invention and the practical application, to thereby enable others skilled in the art to best utilize the invention and various embodiments with various modifications as are suited to the particular use contemplated. The invention is limited only by the claims and their full scope and equivalents.

Claims

1. A display panel, comprising:

an array substrate;

a color film substrate;

the liquid crystal layer is clamped between the array substrate and the color film substrate; and

a plurality of light sensing units arranged on the array substrate, wherein the light sensing surface of each light sensing unit faces the color film substrate,

the color film substrate comprises a black matrix layer, the black matrix layer comprises a plurality of first openings, slit units and first light filtering units covering the slit units are arranged in the first openings, each slit unit comprises two slits which enable light to penetrate and interfere with each other, and the light sensing units can receive the light which penetrates through the first light filtering units and the slit units;

the plurality of light sensing units correspond to the plurality of slit units in groups, each group comprises one light sensing unit and one slit unit which correspond to each other, each slit unit enables transmitted light rays to interfere with each other so as to form interference fringes on a plane where the light sensing surface is located, each interference fringe comprises a plurality of light fringe areas and a plurality of dark fringe areas, and the light fringe areas and the dark fringe areas are alternate,

wherein each of the photosensitive units is located in the bright fringe region corresponding to the interference fringes formed by the slit units and in the dark fringe region corresponding to the interference fringes formed by the adjacent groups of the slit units.

2. The display panel according to claim 1, wherein each of the slit units further includes a light-blocking layer provided around an outline of a cross section of each of the slits perpendicular to a thickness direction of the display panel, the light-blocking layer being connected to the black matrix layer at least partially on a periphery perpendicular to the thickness direction of the display panel.

3. The display panel according to claim 1, wherein a slit width of each slit is 0.5 μm or less.

4. The display panel according to claim 1, wherein a distance between two slits in each slit unit is 1.5 to 3 μm.

5. The display panel according to claim 1, wherein a spacing between two slits in each slit unit satisfies the following condition:

0.9(I·λ/L)≦d≦1.1(I·λ/L)；

wherein d is the distance between two slits in each slit unit;

i is the distance from the slit unit to the plane where the photosensitive surface is located;

λ is the wavelength of the light transmitted by the first filtering unit;

and L is the size of the photosensitive surface of each photosensitive unit in the direction perpendicular to the extending direction of the slit.

6. The display panel according to claim 1, wherein a dimension of the photosensitive surface of each of the photosensitive units in a direction perpendicular to an extending direction of the slits is 4 to 5 micrometers, a distance from the slit unit to a plane where the photosensitive surface is located is 20 micrometers, the first filter unit is a green first filter unit, and a distance between two slits in each of the slit units is 1.8 to 2.2 micrometers.

7. The display panel according to claim 1, wherein a length of each slit in an extending direction of the slit is equal to or greater than a dimension of the light-sensing surface of each light-sensing unit in the extending direction of the slit.

8. The display panel of claim 2, wherein the black matrix layer further comprises a plurality of second openings, the color filter substrate further comprises a second filter unit disposed in the second openings, and light passing through the liquid crystal layer can be transmitted outward through the second filter unit,

wherein the total thickness of the light blocking layer and the first light filtering unit is less than or equal to the thickness of the second light filtering unit.

9. The display panel according to claim 1, wherein the first filter units in the first openings are all filter units of a same color.

10. The display panel according to claim 1, wherein the light sensing unit is an optical fingerprint recognition unit.

11. A display device, comprising the display panel according to any one of claims 1 to 10 and a backlight module disposed opposite to the display panel.