CN110208982B

CN110208982B - Liquid crystal display device having a plurality of pixel electrodes

Info

Publication number: CN110208982B
Application number: CN201910336163.XA
Authority: CN
Inventors: 严斌; 毛春程; 王鹏; 罗建红
Original assignee: Honor Device Co Ltd
Current assignee: Honor Device Co Ltd
Priority date: 2019-04-24
Filing date: 2019-04-24
Publication date: 2021-05-07
Anticipated expiration: 2039-04-24
Also published as: CN110208982A

Abstract

The application provides a liquid crystal display device, relates to and shows technical field for reduce the influence that leading fingerprint identification function accounts for the ratio to terminal equipment's screen. The liquid crystal display device comprises a backlight module, a liquid crystal display module and a cover plate, wherein the liquid crystal display module comprises a display panel, an upper polarizing layer and a lower polarizing layer; the liquid crystal display device also comprises a collimated light emergent structure and a fingerprint acquisition structure; the collimated light emergent structure and the fingerprint collecting structure are positioned between the lower polarizing layer and the cover plate, and the fingerprint collecting structure is positioned on one side of the collimated light emergent structure, which is far away from the cover plate; the light emitting surface of the collimated light emitting structure faces the cover plate, the collimated light emitting structure is at least positioned in the display area of the liquid crystal display device, and part of the collimated light emitting structure positioned in the display area is transparent; the fingerprint collection structure is used for receiving the reflected light of the collimated light of the first angle emitted by the collimated light emergent structure.

Description

Liquid crystal display device having a plurality of pixel electrodes

Technical Field

The application relates to the technical field of display, in particular to a liquid crystal display device.

Background

With the development of optical technology and semiconductor technology, flat terminal devices represented by Liquid Crystal Displays (LCDs) have advantages of lightness, thinness, low power consumption, no radiation, good color purity, high contrast ratio, and the like, and have a leading position in the Display field.

The terminal equipment with high screen ratio becomes a product which is favored by consumers due to the unique appearance. Meanwhile, since fingerprints are unique and distinguishable from other people, the high-screen-ratio terminal device with the fingerprint identification function has become a development trend.

However, to realize the fingerprint identification function, the screen occupation ratio of the terminal device is inevitably affected, and those skilled in the art can increase the screen occupation ratio by moving the fingerprint identification module from the front side of the mobile phone to other places (such as the back side and the periphery), that is, from the front fingerprint to the rear fingerprint or the side fingerprint. However, the back fingerprint or the side fingerprint affects the integrity of the appearance of the terminal device to a certain extent, and no front fingerprint (off-screen fingerprint) is easily accepted by consumers.

Therefore, how to reduce the influence of the front fingerprint identification function of the terminal device on the screen occupation ratio of the terminal device becomes a technical problem to be solved by those skilled in the art.

Disclosure of Invention

The embodiment of the application provides a liquid crystal display device, which is used for reducing the influence of a front fingerprint identification function on the screen ratio of terminal equipment.

In order to achieve the above purpose, the following technical solutions are adopted in this embodiment:

in a first aspect, a liquid crystal display device is provided, which includes a backlight module, a liquid crystal display module and a cover plate, wherein the liquid crystal display module includes a display panel, an upper polarizing layer and a lower polarizing layer, the lower polarizing layer is close to the backlight module, and the upper polarizing layer is close to the cover plate; the liquid crystal display device further includes: a collimated light emitting structure and a fingerprint collecting structure; the collimated light emergent structure and the fingerprint collecting structure are positioned between the lower polarizing layer and the cover plate, and the fingerprint collecting structure is positioned on one side of the collimated light emergent structure, which is far away from the cover plate; the light emitting surface of the collimated light emitting structure faces the cover plate, the collimated light emitting structure is at least positioned in the display area of the liquid crystal display device, and part of the collimated light emitting structure positioned in the display area is transparent; the fingerprint collection structure is used for receiving the reflected light of the collimated light of the first angle emitted by the collimated light emergent structure. The light-transmitting collimated light emitting structure is arranged in the liquid crystal display device, and the light emitting surface of the collimated light emitting structure faces the cover plate, so that light for fingerprint identification is provided under the condition that normal display is not influenced.

Optionally, the projection of the black matrix covers the projection of the fingerprint acquisition structure along the thickness direction of the liquid crystal display device. The fingerprint collection structure is mainly arranged in the area where the black matrix is located, the situation that the fingerprint collection structure is arranged behind the sub-pixel unit and influences the transmittance of light for display can be avoided, and the fingerprint collection structure can realize fingerprint identification under a screen while the pixel aperture opening ratio is not reduced. Need not to gather the structure with the fingerprint and set up at liquid crystal display device's back or side, ensured fuselage structural integrality, brought better unblock and experienced.

Optionally, the fingerprint acquisition structure is integrated within the display panel. The preparation process can be simplified.

Optionally, the display panel further includes an array substrate and an opposite substrate disposed opposite to the array substrate, and the black matrix is disposed on the opposite substrate; the fingerprint collection structure is arranged on one side of the black matrix, which is far away from the array substrate. The filtering of the light reflected to the fingerprint collection structure by the black matrix can be reduced.

Optionally, the fingerprint collection structure is disposed between the upper polarizing layer and the cover plate. The filtering of the light reflected to the fingerprint acquisition result by the black matrix can be reduced.

Optionally, the display panel includes a plurality of sub-pixel units, and the black matrix is located between any adjacent sub-pixel units; the fingerprint collection structure comprises a plurality of fingerprint collection units, the fingerprint collection units correspond to the sub-pixel groups one by one, each sub-pixel group comprises at least one sub-pixel unit, and the sub-pixel units in different sub-pixel groups are different.

Optionally, the collimated light exit structure is disposed between the upper polarizing layer and the cover plate. The loss in the light emitting process can be reduced, the divergence of light rays is reduced, and the fingerprint identification precision is improved.

Optionally, the collimated light exit structure is a collimated light surface light source.

Optionally, the projection of the collimated light surface light source covers the display area along the thickness direction of the liquid crystal display device. Full-screen fingerprint identification can be realized.

Optionally, the collimated light exit structure is a light guide layer, and a first diffraction grating is arranged on the surface of the light guide layer away from the cover plate; the light guide layer comprises a first area, and the first diffraction grating is positioned in the first area; the liquid crystal display device further comprises a collimated light source; the collimated light source is used for emitting collimated light into the light guide layer, and the collimated light is totally reflected in the first area; the first diffraction grating is used for enabling collimated light emitted to the first diffraction grating to be diffracted, and the diffracted 1-order diffracted light is emitted out of the light guide layer; the collimated light source is positioned in a non-display area of the liquid crystal display device, or the collimated light source is positioned on one side, far away from the liquid crystal display module, of the backlight module; the collimated light source is a collimated light point source or a collimated light line source. Through setting up collimated light source in non-display area, carry out the conduction and the outgoing of light through the leaded light layer, so, the material of aiming at each structure of collimated light source does not do the requirement, but reduction in production cost.

Optionally, the collimated light source is a collimated light source; the light guide layer also comprises a second area; the collimated light source is used for emitting collimated light of a second angle and emitting the collimated light into the second area; the second area is used for adjusting a second angle of collimated light emitted by the collimated light source into a third angle and emitting the third angle into the first area. The second area is arranged for light path conversion, so that the requirement for aligning the setting position of the straight light source can be reduced.

Optionally, the collimated light source is a collimated light point source; the light guide layer further comprises a second region and a third region; the surface of the light guide layer, which is far away from the cover plate, is also provided with a second diffraction grating; the second diffraction grating is positioned in the third area; the collimated light point light source is used for emitting collimated light of a second angle and emitting the collimated light into the second area; the second area is used for adjusting a second angle of collimated light emitted by the collimated light point light source into a third angle and emitting the third angle into the third area, and the collimated light of the third angle is used for total reflection in the third area after being emitted into the third area; the second diffraction grating is used for enabling the collimated light emitted to the second diffraction grating to be incident into the first region through the diffracted 1-order diffraction collimated light; wherein, collimated light point source sets up and keeps away from apron one side at the leaded light layer. Through setting up collimated light source into collimated light pointolite to through the third district in the leaded light layer with pointolite conversion line light source, can reduce the occupation of area of collimated light source at non-display area, can reduce the requirement to the integrated level of non-display area part.

Optionally, the non-display area is located outside the display area; the second area and the third area are both located in the non-display area, and the first area covers the display area.

Optionally, the non-display area is located outside the display area; the outline of the display area comprises a groove, the non-display area comprises a convex area, and the convex area is spliced with the groove; the second region is located in the protrusion region, and the first region and the third region are at least located in the display region.

Optionally, the non-display area includes a transparent area and an opaque area, and the display area surrounds the transparent area; the light-tight region is positioned at the outer side of the display region; the second region is located in the light-transmitting region, and the first region and the third region are at least located in the display region.

Optionally, the third region is located at one side of the second region along the first direction; the first region is located on one side of the third region along the second direction; the first direction and the second direction are the length and width directions of the display panel.

Optionally, the third region comprises the first sub-region and the second sub-region; along the first direction, the first sub-area and the second sub-area are respectively positioned at two sides of the second area; along the second direction, the first area is positioned at the same side of the first sub-area, the second sub-area and the second area; the first direction and the second direction are the length and width directions of the display panel.

Optionally, the first region extends to an edge of the display region along the second direction. The area of the fingerprint identification area can be increased.

Optionally, the collimated light source is arranged on one side of the backlight module, which is far away from the liquid crystal display module; the liquid crystal display device further includes a light path converter; the light path converter is positioned in the non-display area; the light path converter is used for enabling the collimated light emitted to the light path converter from the collimated light source to be emitted into the light guide layer. Through setting up collimated light source at backlight unit's back, need not to occupy the area in non-display area, can reduce the requirement of arranging to each part of liquid crystal display device, simplify preparation technology.

Optionally, along a direction perpendicular to the thickness direction of the liquid crystal display device, a first opening is arranged on the liquid crystal display module, a second opening is arranged on the backlight module, and along the thickness direction of the liquid crystal display device, the projection of the protruding region and the projection of the first opening coincide with the projection of the second opening; the liquid crystal display device further comprises a front optical device, and the front optical device and the collimated light source are arranged in the gap formed by the first opening and the second opening. The front-mounted optical device can extend into the liquid crystal display module and the backlight module, and the thickness of the display device is reduced.

Optionally, a first hollow-out area is disposed on each film layer between the first substrate and the second substrate on the surface of the display panel; a second hollow area is arranged on the lower polarizing layer and/or the lower polarizing layer; a third hollow area is arranged on the backlight module; the light transmitting area, the first hollow-out area, the second hollow-out area and the third hollow-out area are overlapped; the liquid crystal display device further comprises a front optical device, and the front optical device and the collimated light source are arranged in the third hollow area. The front-mounted optical device can extend into the backlight module, and the thickness of the display device is reduced.

Optionally, the front-mounted optical device includes a front-mounted camera, and the collimated light source is disposed in a gap between a lens of the front-mounted camera and the liquid crystal display module. The occupied area of the collimated light source can be reduced.

Optionally, the second hollowed-out area is filled with an optically transparent adhesive. By filling the optical transparent adhesive in the upper and lower polarizing layers, the refraction of light can be reduced, and the deformation of the first substrate and the second substrate can be reduced.

Optionally, the liquid crystal display device further comprises a transparent adhesive filling layer, the transparent adhesive filling layer and the light guide layer are arranged on the same layer, the thickness of the transparent adhesive filling layer is equal to that of the light guide layer, and the transparent adhesive filling layer is spliced with the light guide layer; and the projection of the transparent adhesive filling layer is overlapped with the light-transmitting area along the thickness direction of the liquid crystal display device. Through setting up transparent adhesive tape filling layer, can reduce the refraction of light on the one hand, on the other hand can play the supporting role.

Optionally, a first optical transparent adhesive layer is arranged on the surface of the light guide layer close to the cover plate, and the first optical transparent adhesive layer is planar. The first optical transparent adhesive layer plays a role in adhering the light guide layer and the upper polarizing layer, provides conditions for total reflection of the collimated light in the light guide layer, and can simplify the structure of the film layer.

Optionally, a first optical transparent adhesive layer is arranged on the surface of the light guide layer close to the cover plate, and the first optical transparent adhesive layer is annular. The first optical transparent adhesive layer plays a role in adhering the light guide layer and the upper polarizing layer, provides conditions for total reflection of the collimated light in the light guide layer, and can simplify the structure of the film layer.

Optionally, a second optical transparent adhesive layer is arranged on the surface, close to the upper polarizing layer, of the light guide layer, and the second optical transparent adhesive layer is planar. The second optical transparent adhesive layer plays a role in bonding the light guide layer and the lower polarizing layer, provides conditions for total reflection of the collimated light in the light guide layer, and can simplify the structure of the film layer.

Optionally, a second optical transparent adhesive layer is arranged on the surface, close to the upper polarizing layer, of the light guide layer, and the second optical transparent adhesive layer is annular. The second optical transparent adhesive layer plays a role in bonding the light guide layer and the lower polarizing layer, provides conditions for total reflection of the collimated light in the light guide layer, and can simplify the structure of the film layer.

Optionally, the collimated light is visible light, and the collimated light of the first angle is used for total reflection on the surface of the cover plate far away from the liquid crystal display module. After the collimated light of first angle takes place the total reflection at the surface of keeping away from the liquid crystal display module assembly of apron, can not produce the interference to showing light, and the visible light source is comparatively general, and the cost is lower.

Drawings

Fig. 1 is a schematic diagram of a frame of a liquid crystal display device according to an embodiment of the present disclosure;

fig. 2a is a schematic structural diagram of a backlight module according to an embodiment of the present disclosure;

fig. 2b is a schematic structural diagram of another backlight module according to an embodiment of the present disclosure;

fig. 3a is a schematic top view of a liquid crystal display device according to an embodiment of the present disclosure;

FIG. 3b is a cross-sectional view taken along line O-O' of FIG. 3 a;

FIG. 4a is a schematic top view of a display panel according to an embodiment of the present application;

FIG. 4b is a schematic side view of a display panel according to an embodiment of the present application;

fig. 5a is a schematic diagram illustrating a position relationship between a fingerprint acquisition structure and a black matrix according to an embodiment of the present disclosure;

fig. 5b is a schematic diagram illustrating a position relationship between another fingerprint acquisition structure and a black matrix according to an embodiment of the present application;

FIG. 6 is another cross-sectional view taken along line O-O' of FIG. 3 a;

FIG. 7 is a further cross-sectional view taken along line O-O' of FIG. 3 a;

FIG. 8 is a further cross-sectional view taken along line O-O' of FIG. 3 a;

FIG. 9 is a further cross-sectional view taken along line O-O' of FIG. 3 a;

FIG. 10 is a further cross-sectional view taken along line O-O' of FIG. 3 a;

FIG. 11 is a further cross-sectional view taken along line O-O' of FIG. 3 a;

FIG. 12 is a further cross-sectional view taken along line O-O' of FIG. 3 a;

FIG. 13 is a further cross-sectional view taken along line O-O' of FIG. 3 a;

fig. 14 is a schematic diagram illustrating a positional relationship between a fingerprint acquisition unit and a pixel unit group according to an embodiment of the present disclosure;

fig. 15 is a schematic structural view of a light guide layer according to an embodiment of the present disclosure;

FIG. 16 is a schematic side view of an LCD device according to an embodiment of the present application;

FIG. 17 is a schematic side view of another LCD device according to the present disclosure;

fig. 18 is a schematic structural view of a first optical transparent adhesive layer, a light guide layer, and a second optical transparent adhesive layer according to an embodiment of the present disclosure;

fig. 19 is a schematic structural view of another first optical transparent adhesive layer, a light guide layer, and a second optical transparent adhesive layer according to an embodiment of the present disclosure;

fig. 20 is a schematic structural view of another first optical transparent adhesive layer, a light guide layer, and a second optical transparent adhesive layer according to an embodiment of the present disclosure;

fig. 21 is a schematic structural view of another first optical transparent adhesive layer, a light guide layer, and a second optical transparent adhesive layer according to an embodiment of the present disclosure;

FIG. 22 is a schematic side view of another LCD device provided in the present application;

fig. 23 is a schematic diagram illustrating a relationship between a light guide plate and a collimated light source according to an embodiment of the present disclosure;

FIG. 24 is a cross-sectional view taken along line A-A' of FIG. 23;

FIG. 25 is a schematic side view of another LCD device provided in the embodiments of the present application;

FIG. 26 is a schematic diagram illustrating a relationship between another light guide plate and a collimated light source according to an embodiment of the present disclosure;

FIG. 27 is a cross-sectional view taken along line B-B' of FIG. 26;

fig. 28 is a schematic structural diagram of a diffraction grating according to an embodiment of the present application;

fig. 29a is a schematic view illustrating a positional relationship between a light guide layer and a display region and a non-display region according to an embodiment of the present disclosure;

fig. 29b is a schematic view illustrating a positional relationship between another light guide layer and a display region and a non-display region according to an embodiment of the present disclosure;

FIG. 30a is a schematic diagram illustrating a positional relationship between a light guide layer and a display region and a non-display region according to an embodiment of the present disclosure;

FIG. 30b is a schematic diagram illustrating a positional relationship between a light guide layer and a display region and a non-display region according to an embodiment of the present disclosure;

fig. 31 is a schematic top view illustrating another lcd device according to an embodiment of the present disclosure;

FIG. 32 is a cross-sectional view taken along line C-C' of FIG. 31;

FIG. 33 is a schematic view illustrating a positional relationship between a light guide layer and a display region and a non-display region according to an embodiment of the present disclosure;

FIG. 34 is a schematic view illustrating a positional relationship between a light guide layer and a display region and a non-display region according to an embodiment of the present disclosure;

fig. 35 is a schematic top view illustrating a further liquid crystal display device according to an embodiment of the present application;

FIG. 36 is a cross-sectional view taken along line D-D' of FIG. 35;

FIG. 37 is another cross-sectional view taken along line D-D' of FIG. 35;

FIG. 38 is a further cross-sectional view taken along line D-D' of FIG. 35;

FIG. 39 is a schematic diagram illustrating a positional relationship between a light guide layer and a display region and a non-display region according to an embodiment of the present disclosure;

FIG. 40 is a schematic view illustrating a positional relationship between a light guide layer and a display region and a non-display region according to an embodiment of the present disclosure;

fig. 41 is a schematic view illustrating a positional relationship between a light guide layer and a display region and a non-display region according to an embodiment of the present disclosure.

Reference numerals:

1-a frame; 2-cover plate; 3-a liquid crystal display module; 30-a display panel; 300-pixels; 310-a first color sub-pixel unit; 320-a second color sub-pixel cell; 330-third color sub-pixel unit; 301-subpixel group; 31-an array substrate; 311-a first substrate; 313-pixel electrodes; 314-common electrode; 315-a first insulating layer; 316-second insulating layer; 32-a counter substrate; 321-a second substrate; 322-black matrix; 3221-a first light-shielding strip; 3222-a second light-shielding bar; 323-color filter layer; 33-a liquid crystal layer; 34-an upper polarizing layer; 35-a lower polarizing layer; 36-a first opening; 4-a backlight module; 41-a light source; 42-a reflective sheet; 43-a light guide plate; 44-an optical film; 45-a second opening; 5-a circuit board; 6-collimated light exit structure; 60-a light guide layer; 61-a first zone; 62-a second zone; 63-a third zone; 631-a first sub-region; 632-a second subregion; 64-a first diffraction grating; 65-a second diffraction grating; 7-fingerprint collection structure; 70-fingerprint acquisition unit; 8-a collimated light source; 81-collimated light source; 82-collimated light point source; 9-a light path converter; 11-a first optically clear adhesive layer; 12-a second optically clear adhesive layer; 10-a display area; 20-a non-display area; 21-a raised area; 22-a light-transmitting region; 23-opaque region; 13-front optics; 14-a first hollowed-out area; 15-a second hollowed-out area; 151-optically clear adhesive; 16-a third hollowed-out area; 17-transparent adhesive filling layer.

Detailed Description

Unless otherwise defined, technical or scientific terms used herein shall have the ordinary meaning as understood by those skilled in the art. The terms "first," "second," "third," and the like as used in the description and in the claims of the present application do not denote any order, quantity, or importance, but rather are used to distinguish one element from another. Thus, features defined as "first", "second", "third" may explicitly or implicitly include one or more of the features. In the description of the embodiments of the present application, "a plurality" means two or more unless otherwise specified.

The orientation terms "left", "right", "upper" and "lower" are defined with respect to the orientation in which the liquid crystal display device is schematically placed in the drawings, and it should be understood that these directional terms are relative concepts, which are used for the description and clarification of the relative terms, and may be changed accordingly according to the change of the orientation in which the liquid crystal display device is placed.

With the development of display technology, liquid crystal display technology has been widely used in various display devices. As shown in fig. 1, the main structure of the liquid crystal display device includes a frame 1, a cover plate 2, a liquid crystal display module 3, a backlight module 4, a circuit board 5, and other electronic components including a camera. The liquid crystal display module 3 includes a display panel 30, an upper polarizing layer 34 disposed on a side of the display panel 30 close to the cover plate 2, and a lower polarizing layer 35 disposed on a side of the display panel 30 close to the backlight module 4. The display panel 30 includes an array substrate 31, an opposite substrate 32, and a liquid crystal layer 33 disposed between the array substrate 31 and the opposite substrate 32, wherein the array substrate 31 and the opposite substrate 32 are bonded together by a frame sealing adhesive, so that the liquid crystal layer 33 is limited in a region surrounded by the frame sealing adhesive. When the color filter layer is disposed on the opposite substrate 32, the opposite substrate 32 is a color filter substrate.

The longitudinal section of the frame 1 is U-shaped, the liquid crystal display module 3, the backlight module 4, the circuit board 5 and other electronic accessories including a camera and the like are arranged in the frame 1, the backlight module 4 is positioned below the liquid crystal display module 3, the circuit board 5 is positioned between the backlight module 4 and the frame 1, and the cover plate 2 is positioned on one side of the liquid crystal display module 3 far away from the backlight module 4.

The cover plate 2 may be, for example, transparent glass.

As shown in fig. 2a and 2b, the backlight module 4 includes a light source 41, a reflective sheet 42, a light guide plate 43, and an optical film 44 disposed on the light-emitting side of the light guide plate 43. The optical film 44 may include a diffusion sheet, a brightness enhancement film, or the like. When the optical film 44 includes a diffusion sheet and a brightness enhancement film, the diffusion sheet is provided on the light exit side of the light guide plate 43, and the brightness enhancement film is provided on the diffusion sheet on the side away from the light guide plate 43. The brightness enhancement film may include a prism film (BEF) and a reflection type polarization enhancement film (DBEF), which may be used in combination.

As shown in fig. 2a, the light source 41 can be disposed on the side surface of the light guide plate 43, in which case the backlight module 4 is a side-in type backlight module. As shown in fig. 2b, the light source 41 may also be disposed on a side of the light guide plate 43 away from the light emitting side, in which case the backlight module 4 is a direct-type backlight module. The Light source 41 may be, for example, a Light-Emitting Diode (LED). The structure of the backlight module 4 in fig. 2a and 2b is only schematic and not limited at all.

The display principle of the liquid crystal display device of fig. 1 is as follows: the backlight module 4 emits white light, and white polarized light with a specific polarization direction is formed through the lower polarizing layer 35 and enters the array substrate 31, and then is filtered by the color filter layer on the color film substrate to form polarized light of three primary colors of red, green and blue. When the polarization direction of the polarized light is perpendicular to the polarization direction of the upper polarizing layer 34, the polarized light cannot pass through the upper polarizing layer 34, and no light exits at this time; when the polarization direction of the polarized light is parallel to the polarization direction of the upper polarizing layer 34, the polarized light can pass through the upper polarizing layer 34, and the intensity of the emergent light is strongest at this time. Since the liquid crystal molecules have a light-rotating property to polarized light, the specific arrangement direction of the molecules can change the polarization direction of the polarized light, and when the arrangement direction of the liquid crystal molecules is controlled by the electric fields of the pixel electrode and the common electrode to rotate, the polarization direction of the polarized light passing through the liquid crystal molecules is also changed, so that the amount of the polarized light emitted from the upper polarizing layer 34 can be controlled. When the pixel electrodes and the common electrode regularly control the liquid crystal molecules to rotate according to the electric signals applied to the respective electrodes, the light of the red, green and blue sub-pixels regularly transmits through the upper polarizing layer 34, and finally a color image is formed. The light path propagation sequence is as follows: the backlight module 4 emits light through the lower polarizing layer 35, the array substrate 31, the liquid crystal layer 33, the counter substrate 32, and the upper polarizing layer 34 in this order to the cover plate 2.

An embodiment of the present application provides a liquid crystal display device, as shown in fig. 3a and 3b, including a backlight module 4, a liquid crystal display module 3 and a cover plate 2, where the liquid crystal display module 3 includes a display panel 30, an upper polarizing layer 34 and a lower polarizing layer 35, the lower polarizing layer 35 is close to the backlight module 4, and the upper polarizing layer 34 is close to the cover plate 2.

The display panel 30 may be any one of an FFS (Fringe Field Switching) type liquid crystal display panel, an IPS (In Plane Switch) type liquid crystal display panel, and a TN (twisted Nematic) type liquid crystal display panel.

In the TN liquid crystal display panel, the common electrode is provided on the counter substrate 32, and the pixel electrode is provided on the array substrate 31, and the shapes of the common electrode and the pixel electrode are not limited.

For the FFS type lcd panel, the common electrode and the pixel electrode are disposed on the array substrate 31, the common electrode and the pixel electrode are disposed in different layers, the electrode on the upper layer includes a plurality of stripe electrodes, and the electrode on the lower layer includes a plurality of stripe electrodes or is in a flat plate shape. For example, an electrode including a plurality of bar-shaped electrodes positioned on an upper layer is a pixel electrode, and a plate-shaped electrode positioned on a lower layer is a common electrode.

For the IPS mode liquid crystal display panel, the common electrode and the pixel electrode are both disposed on the array substrate 31, the common electrode and the pixel electrode are disposed on the same layer, the common electrode includes a plurality of first stripe electrodes, the pixel electrode includes a plurality of second stripe electrodes, and the first stripe electrodes and the second stripe electrodes are disposed at intervals.

The display panel 30 includes an array substrate 31, an opposite substrate 32, and a liquid crystal layer 33 disposed between the array substrate 31 and the opposite substrate 32, wherein the array substrate 31 and the opposite substrate 32 are bonded together by a frame sealing adhesive, so that the liquid crystal layer 33 is limited in a region surrounded by the frame sealing adhesive.

As shown in fig. 4a, the display panel 30 includes a plurality of pixels 300, each pixel includes a plurality of sub-pixel units, the plurality of sub-pixel units includes a first color sub-pixel unit 310, a second color sub-pixel unit 320 and a third color sub-pixel unit 330, and an area where the pixels 300 are disposed on the display panel 30 is the display area 10 of the liquid crystal display device.

Taking an FFS type liquid crystal display panel as an example, as shown in fig. 4b, each sub-pixel unit includes a TFT (Thin Film Transistor) and a pixel electrode 313 on a first substrate 311 of an array substrate 31, and the pixel electrode 313 is electrically connected to a drain (or source) of the TFT. On this basis, the array substrate 31 is further provided with a common electrode 314, wherein, in order to conveniently supply power to the common electrode 314, the common electrodes 314 in all the sub-pixel units can be connected into a whole. The TFT, the pixel electrode 313, and the common electrode 314 are disposed on a side of the first substrate 311 facing the counter substrate 32.

In fig. 4b, the common electrode 314 is shown between the TFT and the pixel electrode 313, in which case the common electrode 314 and the pixel electrode 313 are isolated by the first insulating layer 315. Further, a second insulating layer 316 may be disposed between the TFT and the common electrode 314, and based on this, the pixel electrode 313 is electrically connected to the drain electrode of the TFT through a channel located on the first insulating layer 315, the common electrode 314, and the second insulating layer 316. The first insulating layer 315 and the second insulating layer 316 are uniformly laid in a region where the pixel 300 is disposed, and only the first insulating layer 315 in the region needs to be removed, or the second insulating layer 316 in the region needs to be removed, or the first insulating layer 315 in the region and the second insulating layer 316 in the region need to be removed.

The common electrode 314 may also be disposed on a side of the pixel electrode 313 away from the TFT, in which case, the common electrode 314 and the pixel electrode 313 may also be isolated by the first insulating layer 315, and the common electrode 314 includes a plurality of stripe electrodes.

Each sub-pixel unit further includes a color filter 323 (CF) on the second substrate 321 of the opposite substrate 32, in this case, the opposite substrate 32 is a color film substrate. The color filter layer 323 in the first color sub-pixel unit 310 is a first color filter layer, the color filter layer 323 in the second color sub-pixel unit 320 is a second color filter layer, and the color filter layer 323 in the third color sub-pixel unit 330 is a third color filter layer. Illustratively, the first color is red, the second color is green, and the third color is blue.

The material of the first color filter layer, the second color filter layer or the third color filter layer comprises a material formed by mixing a polymer material and an organic dye. The three layers of materials of the first color filter layer, the second color filter layer and the third color filter layer are different in that the organic dye is different.

In order to prevent crosstalk between the primary light emitted from the adjacent sub-pixel units, the counter substrate 32 is further provided with a black matrix 322 (BM), and the black matrix 322 is located between the adjacent sub-pixel units. The color filter layer 323 and the black matrix 322 are both provided on the side of the counter substrate 32 facing the array substrate 31.

The lower polarizing layer 35 of the liquid crystal display device may be a conventional polarizer, or may be a Grid Polarizer (GP).

When the lower polarizing layer 35 is a wire grid polarizing layer, the material of the wire grid polarizing layer may be a metal. The wire grid polarizer layer can be fabricated directly on the first substrate 311 by sputtering, nanoimprinting, photolithography, and the like. The material of the wire grid polarizer layer includes, but is not limited to, aluminum (Al), copper (Cu), silver (Ag), gold (Au), chromium (Cr), and the like.

When the lower polarizing layer 35 is a wire grid polarizing layer, the wire grid polarizing layer may be formed on the side of the first substrate 311 facing the opposite substrate 32, and may also be formed on the side of the first substrate 311 away from the opposite substrate 32. When the lower polarizing layer 35 is a conventional polarizer, the lower polarizing layer 35 is formed on the side of the first substrate 311 away from the opposite substrate 32. The present embodiment is illustrated with the lower polarizing layer 35 formed on the side of the first substrate 311 remote from the counter substrate 32.

The upper polarizing layer 34 of the liquid crystal display device may be a conventional polarizer, or alternatively, may be a wire grid polarizing layer.

When the upper polarizing layer 34 is a wire grid polarizing layer, the wire grid polarizing layer may be formed on a side of the second substrate 321 facing the array substrate 31, and may also be formed on a side of the second substrate 321 away from the array substrate 31. When the upper polarizing layer 34 is a conventional polarizer, the upper polarizing layer 34 is formed on a side of the second substrate 321 away from the array substrate 31. The present embodiment is illustrated in a manner that the upper polarizing layer 34 is formed on the side of the second substrate 321 away from the array substrate 31.

On this basis, the liquid crystal display device further includes: a collimated light exit structure 6 and a fingerprint collection structure 7; collimated light exit structure 6 and fingerprint collection structure 7 are located between lower polarized layer 35 and apron 2, and fingerprint collection structure 7 is located collimated light exit structure 6 and keeps away from apron 2 one side.

The light emitting surface of the collimated light emitting structure 6 faces the cover plate 2, the collimated light emitting structure 6 is at least located in the display area 10 of the liquid crystal display device, and a part of the collimated light emitting structure 6 located in the display area 10 is transparent.

The collimated light (light for fingerprint recognition) emitted from the collimated light emitting structure 6 may be visible light or invisible light.

In the case where the collimated light is visible light, the display effect is not affected by the interference of the light for fingerprint recognition with the light for display. The angle of the collimated light that jets out from collimated light exit structure 6 is first angle, and the collimated light of first angle is used for taking place the total reflection on the surface of keeping away from liquid crystal display module 3 at apron 2.

The fingerprint collection structure 7 is used for receiving the reflected light of the collimated light of the first angle emitted by the collimated light emitting structure 6 and collecting fingerprints.

In some embodiments, as shown in fig. 5a, the orthographic projection of the fingerprint acquisition structure 7 on the cover plate 2 overlaps with the orthographic projection of the sub-pixel elements on the cover plate 2.

It will be appreciated that in this case the portion of the orthographic projection of the fingerprint acquisition structure 7 on the cover plate 2 that overlaps the orthographic projection of the sub-pixel elements on the cover plate 2 is transparent in order not to obscure the display light. A black matrix 322 is arranged between adjacent sub-pixel units, and a part of the orthographic projection of the fingerprint collection structure 7 on the cover plate 2, which is overlapped with the orthographic projection of the black matrix 322 on the cover plate 2, can be opaque.

Although the part of the orthographic projection of the fingerprint collection structure 7 on the cover plate 2 overlapping the orthographic projection of the sub-pixel unit on the cover plate 2 is transparent, it still affects the transmittance of the display light. In some embodiments, as shown in fig. 5b, the projection of the black matrix 322 covers the projection of the fingerprint acquisition structure 7 along the thickness direction of the liquid crystal display device.

That is to say, there is no overlapping part of the orthographic projection of the fingerprint acquisition structure 7 on the cover plate 2 and the orthographic projection of the sub-pixel elements on the cover plate 2.

As shown in fig. 5b, the black matrix 322 includes a plurality of first light-shielding bars 3221 extending along the first direction and a plurality of second light-shielding bars 3222 extending along the second direction, and each of the first light-shielding bars 3221 and the second light-shielding bars 3222 is located between adjacent sub-pixel units. The first direction and the second direction are respectively a row direction and a column direction of the arrangement of the sub-pixel units, for example, the first direction is a horizontal direction, and the second direction is a vertical direction.

Fingerprint collection structure 7 sets up in the below of collimation light exit structure 6, and regarding fingerprint collection structure 7's the position of setting, in order to improve fingerprint collection structure 7 and to the collection effect of reverberation, minimize light loss, as shown in fig. 3b, optionally, fingerprint collection structure 7 can set up between upper polarization layer 34 and collimation light exit structure 6.

As shown in fig. 6, optionally, the fingerprint acquisition structure 7 is integrated in the display panel 30.

The fingerprint acquisition structure 7 is integrated in the display panel 30, it being understood that the display panel 30 comprises the fingerprint acquisition structure 7. That is, in the process of manufacturing the display panel 30, the fingerprint collection structure 7 is formed. For example, some of the film layers in the fingerprint collection structure 7 may be formed by the same patterning process as some of the film layers in the display panel 30, or each of the film layers in the fingerprint collection structure may be formed separately.

In some embodiments, as shown in fig. 6-8, the fingerprint acquisition structure 7 is integrated on the array substrate 31.

Based on this, optionally, as shown in fig. 6, the fingerprint acquisition structure 7 is disposed on the surface of the first substrate 311 near the lower polarizing layer 35.

Alternatively, as shown in fig. 7, the fingerprint acquisition structure 7 is disposed on the first substrate 311 on the side close to the liquid crystal layer 33.

The fingerprint collection structure 7 may include, for example, a photoelectric converter and a detection circuit, and the detection circuit in the fingerprint collection structure 7 may be formed in synchronization with the TFTs in the array substrate 31.

Alternatively, as shown in fig. 8, the fingerprint collection structure 7 is disposed on the side of the pixel electrode 313 close to the liquid crystal layer 33.

In some embodiments, as shown in fig. 9-11, the fingerprint acquisition structure 7 is integrated on the counter substrate 32.

Based on this, in order to reduce the filtering of the black matrix 322 for the light reflected to the fingerprint collection structure 7, optionally, as shown in fig. 9, the fingerprint collection structure 7 is disposed on the surface of the second substrate 321 close to the upper polarizing layer 34.

In order to simplify the manufacturing process on the basis of reducing the filtering of the black matrix 322 on the light reflected to the fingerprint collection structure 7, optionally, as shown in fig. 10, the fingerprint collection structure 7 is disposed on the side of the black matrix 322 far from the array substrate 31.

That is, the fingerprint collection structure 7 is disposed between the second substrate 321 and the black matrix 322.

Alternatively, as shown in fig. 11, the fingerprint collection structure 7 is disposed on a side of the black matrix 322 close to the array substrate 31.

It can be understood that although the fingerprint collection structure 7 is disposed below the black matrix 322, the collimated light reflected by the cover plate 2 can be emitted to the fingerprint collection structure 7 through the area where the sub-pixel units are located, so as to ensure that the fingerprint collection structure 7 realizes the fingerprint collection function.

For the collimated light exit structure 6, the collimated light exit structure 6 may be located only in the display region 10, or may extend from the display region 10 to the non-display region 20, but in order to prevent the collimated light exit structure 6 from blocking the backlight, each layer of the film material of the part of the collimated light exit structure 6 located in the display region 10 must transmit light to avoid the part of the collimated light exit structure 6 located in the display region 10 from affecting the display.

Wherein, in order to prevent shading of the collimated light that backlight unit 4 aimed at straight light exit structure 6 and the common filtration that straight light was aimed at to upper polarizing layer 34 and lower polarizing layer 35, lead to unable light-emitting, collimated light exit structure 6 can set up arbitrary position department between lower polarizing layer 35 and apron 2, and this application embodiment does not limit to this.

On the basis, in order to reduce the loss in the light emitting process, reduce the divergence of light rays and improve the fingerprint identification precision, the distance between the collimated light emitting structure 6 and the cover plate 2 can be as close as possible. Optionally, a collimated light exit structure 6 is arranged between the upper polarizing layer 34 and the cover plate 2.

It will be appreciated that when both the collimated light exit structure 6 and the fingerprint collection structure 7 are disposed between the upper polarizing layer 34 and the cover plate 2, as shown in figure 3b, the fingerprint collection structure 7 is still located below the collimated light exit structure 6.

Because the collimated light of the first angle that collimated light exit structure 6 jetted out is to apron 2, consequently, under the condition that the wavelength of the collimated light of first angle was invisible light wave band, apron 2 can be jetted out to the collimated light of first angle, also can take place the total reflection at the surface of apron 2 of keeping away from liquid crystal display module 3, no matter which kind of condition, all can not influence normal demonstration. But under the condition that the wavelength of the collimated light at first angle is the visible light wave band, light production interference is used for showing after the collimated light who avoids first angle jets out apron 2, and influence normal demonstration, under the condition that the wavelength of the collimated light of the first angle that 6 collimated light exit structures jetted out is visible light, the collimated light of first angle is used for taking place the total reflection at the surface of keeping away from liquid crystal display module 3 of apron 2, thereby ensure that the user sees the light that 6 collimated light exit structures of invisible (this part of light is used for fingerprint identification), normal demonstration that does not influence terminal equipment.

It can be understood that, because the refracting index of air is less than the refracting index of apron 2, consequently, as long as set well the angle of the collimated light that collimated light exit structure 6 jetted out, first angle satisfies the condition of total reflection promptly, the collimated light that collimated light exit structure 6 jetted out can take place the total reflection at the surface of apron 2 of keeping away from liquid crystal display module 3.

When the finger was placed on apron 2, the collimation light of first angle was through the surperficial reflection of the liquid crystal display module 3 of keeping away from of apron 2, and directive fingerprint collection structure 7 because the light intensity of finger valley line department and ridge department reverberation is different, consequently, fingerprint collection structure 7 can be according to the completion fingerprint collection work of the reverberation of receiving.

As shown in fig. 3b, the collimated light exit structure 6 may cover the whole display area 10, at which point the liquid crystal display device may achieve full-screen front fingerprinting. As shown in fig. 12 and 13, the collimated light emitting structure 6 may be disposed in the display area 10, but does not cover the display area 10, and the liquid crystal display device may realize partial area pre-fingerprinting.

It can be understood that fingerprint collection structure 7 is used for receiving the reverberation of the light that collimated light exit structure 6 jetted out, therefore, fingerprint collection structure 7 and collimated light exit structure 6's relative position relation need satisfy the reverberation that can receive the light that collimated light exit structure 6 jetted out, and the specific position that sets up of fingerprint collection structure 7 is related to with the first angle of the collimated light that collimated light exit structure 6 jetted out, and two parameters mutually support can.

The principle that the liquid crystal display device provided by the application realizes fingerprint identification is as follows: as shown in fig. 12, the fingerprint includes valleys and ridges, and when a finger is placed on the cover 2 during fingerprint recognition, the ridges of the fingerprint may contact the cover 2, and air may be trapped between the valleys and the cover 2.

In the case where the wavelength of the collimated light emitted from the collimated light emitting structure 6 is visible light, total reflection occurs when the collimated light is emitted from the cover plate 2 to the air. Therefore, when the collimated light of the first angle emitted by the collimated light emitting structure 6 irradiates the position of the fingerprint valley line, because air exists between the valley line and the cover plate 2, the collimated light of the first angle can be reflected by total reflection and irradiate on the fingerprint collection structure 7. Since the refractive index of the finger is close to that of the glass, when the collimated light of the first angle emitted by the collimated light emitting structure 6 is irradiated to the position of the ridge line, the collimated light of the first angle is emitted into the finger, and is refracted without being totally reflected. Therefore, the fingerprint collection structure 7 obtains the distribution of the valleys and ridges of the finger fingerprint according to the brightness of the received reflected light, wherein the bright light (strong electrical signal) represents the positions of the valleys, and the dark light (weak electrical signal) represents the positions of the ridges, thereby realizing fingerprint identification.

When the wavelength of the collimated light emitted from the collimated light emitting structure 6 is invisible light, the collimated light may or may not be totally reflected when it is emitted from the cover plate 2 to the air. If the collimated light is totally reflected when it is emitted from the cover plate 2 to the air, the principle is the same as that the wavelength of the collimated light emitted from the collimated light emitting structure 6 is visible light, and the details are not described here. If the collimated light is not totally reflected when the collimated light is emitted to the air from the cover plate 2, although the collimated light is refracted at the valley line and the ridge line, the intensity of the reflected light on the reflection light path of the collimated light is different after the collimated light is refracted at the valley line and the collimated light is refracted at the ridge line due to the different refractive indexes of the air and the finger. Therefore, the fingerprint collection structure 7 obtains the distribution of the valleys and ridges of the fingerprint according to the brightness of the received reflected light, thereby realizing fingerprint identification.

In the liquid crystal display device, the light-transmitting collimated light emitting structure 6 is arranged in the liquid crystal display device, and the light emitting surface of the collimated light emitting structure 6 faces the cover plate 2, so that light for fingerprint identification is provided without affecting normal display. On this basis, set up fingerprint collection structure 7 mainly in black matrix 322 place region, extend to the partial printing opacity outside the black matrix 322 place region to fingerprint collection structure 7 receives the reverberation of the collimated light of the first angle that collimated light exit structure 6 jetted out, makes fingerprint collection structure 7 realize fingerprint identification under the screen when not reducing the pixel aperture ratio. The fingerprint acquisition structure 7 is not required to be arranged on the back or the side of the liquid crystal display device, the integrity of the machine body structure is guaranteed, and better experience is brought.

Optionally, as shown in fig. 14, the fingerprint acquisition structure 7 includes a plurality of fingerprint acquisition units 70, the fingerprint acquisition units 70 correspond to the sub-pixel groups 301 one to one, each sub-pixel group 301 includes at least one sub-pixel unit, and the sub-pixel units included in different sub-pixel groups 301 are different.

The sub-pixel unit may be, for example, a first color sub-pixel unit 310, a second color sub-pixel unit 320, or a third color sub-pixel unit 330, and, for example, the sub-pixel unit may be, for example, a red sub-pixel unit R for emitting red light, or a green sub-pixel unit G for emitting green light, or a blue sub-pixel unit B for emitting blue light.

One sub-pixel group 301 comprises at least one sub-pixel unit, and the same sub-pixel unit does not belong to two sub-pixel groups 301. The number of sub-pixel units included in the plurality of sub-pixel groups 301 in the display panel 30 may be the same or different.

It can be understood that, since the projection of the black matrix 322 covers the projection of the fingerprint acquisition structure 7 along the thickness direction of the liquid crystal display device, the fingerprint acquisition unit 70 is disposed in the area where the black matrix 322 is located, and is not disposed in the area where the sub-pixel unit is located. Here, that one fingerprint collection unit 70 corresponds to one sub-pixel group 301 means that the fingerprint collection unit 70 is disposed above or below the black matrix 322 in the region where the sub-pixel group 301 is located.

Optionally, the collimated light exit structure 6 is a collimated light surface light source.

To achieve full screen fingerprinting, in some embodiments, the projection of the collimated light area source covers the display area along the thickness direction of the liquid crystal display device.

In some embodiments, the collimated light exit structure 6 is a light guiding layer 60, as shown in fig. 15, the surface of the light guiding layer 60 away from the cover plate 2 is provided with a first diffraction grating 64; light guiding layer 60 includes a first region 61, and a first diffraction grating 64 is located in first region 61.

As shown in fig. 16, the liquid crystal display device further includes a collimated light source 8; the collimated light source 8 is used for emitting collimated light into the light guide layer 60, and the collimated light is totally reflected in the first area 61; the first diffraction grating 64 is for allowing the 1 st order diffracted light, which is diffracted by the collimated light that has been incident on the first diffraction grating 64, to exit the light guide layer 60.

Alternatively, as shown in fig. 16, the collimated light source 8 is located in the non-display area 20 of the liquid crystal display device in the thickness direction of the liquid crystal display device.

The first region 61 may be located in the display region 10, and may also extend to the non-display region 20, and fig. 16 illustrates an example in which the first region 61 extends to the non-display region 20, and light emitted from the collimated light source 8 directly enters the first region 61.

The collimated light source 8 may be a collimated light point source 82 or a collimated light source 81, and the collimated light source 8 may be a laser, for example.

It can be understood that if the collimated light emitted from the collimated light source 8 directly enters the first region 61 of the light guide layer 60 and then is totally reflected in the first region 61, the collimated light emitted from the collimated light source 8 may directly enter the first region 61 of the light guide layer 60, or may enter the first region 61 after being subjected to angle conversion by other regions of the light guide layer 60. If the collimated light emitted from the collimated light source 8 directly enters the first region 61 of the light guide layer 60 and then is not totally reflected in the first region 61, the collimated light emitted from the collimated light source 8 may be subjected to angle conversion by other regions of the light guide layer 60 and then enters the first region 61. In either case, as shown in fig. 15, the angle of collimated light incident on the first region 61 needs to be such that total reflection occurs in the first region 61, that is, light transmission occurs in the first region 61.

The refractive index of the layer structure on the upper and lower sides of the first region 61 of the light guide layer 60 is smaller than that of the light guide layer 60, for example, the light guide layer 60 is disposed between the cover plate 2 and the upper polarizing layer 34, the layer structure on the upper and lower sides of the first region 61 may be, for example, glue or air, and the material of the first region 61 may be, for example, Polycarbonate (PC), polymethyl methacrylate (PMMA), Polydimethylsiloxane (PDMS), or glass.

The first diffraction grating 64 is located in the first region 61, and as shown in fig. 15, according to the characteristics of the diffraction grating, the exit angle a of the 0 th order diffraction light of the light incident on the diffraction grating is the same as the angle a of the incident light, the exit angle b of the 1 st order diffraction light is smaller than the angle a of the incident light, the 0 th order diffraction light carries most of the energy of the incident light, and the 1 st order diffraction light carries most of the remaining energy of the incident light. Therefore, when the collimated light incident on the first region 61 is incident on the first diffraction grating 64, the 0 th order diffracted light is totally reflected by the first region 61 and propagates. The 1-order diffraction grating can emit light out of the first area 61 and emit the light to the cover plate 2 as light for fingerprint collection because the light angle changes and the condition of total reflection is not met. Therefore, the first region 61 of the light guide layer 60 can realize both light transmission and light emission.

It can be understood that, in the case that the wavelength of the collimated light emitted from the collimated light source 8 is in the visible light band, the emitting angle b of the 1 st order diffracted light after the collimated light is diffracted on the first diffraction grating 64 should be the first angle, so that the 1 st order diffracted light is totally reflected on the surface of the cover plate 2 away from the liquid crystal display module 3.

The collimated light source 8 and the light guide layer 60 are matched for use, the collimated light source 8 provides a line light source or a point light source, light is conducted and emitted through the light guide layer 60, the effect similar to that of a collimated light source is achieved, and large-area light for fingerprint identification is provided. In addition, by disposing the collimated light source 8 in the non-display area 20, display is not affected, and the requirement for aligning the collimated light source 8 can be reduced.

Alternatively, as shown in fig. 17, the collimated light source 8 may also be located on the side of the backlight module 4 away from the liquid crystal display module 3.

No matter where the collimated light source 8 is disposed, the collimated light emitted from the collimated light source 8 needs to be directed to the light guide layer 60, and may be directed to the light guide layer 60 or indirectly directed to the light guide layer 60.

In some embodiments, as shown in fig. 17, the collimated light source 8 is disposed on the side of the backlight module 4 away from the liquid crystal display module 3; the liquid crystal display device further includes a light path converter 9; the light-path converter 9 is located in the non-display area 20; the light path converter 9 is configured to inject the collimated light emitted from the collimated light source 8 to the light path converter 9 into the light guide layer 60.

Collimated light source 8 sets up and keeps away from liquid crystal display module 3 one side at backlight unit 4, can not have the sheltering from to the light that backlight unit 4 sent, consequently, collimated light source 8 can be located display area 10, also can be located non-display area 20.

Through setting up collimated light source 8 at backlight unit 4's back, need not to occupy the area of non-display area 20, can reduce the requirement of arranging to each part of liquid crystal display device, simplify preparation technology.

Optionally, the light guide layer 60 is disposed between the cover plate 2 and the upper polarizer 34, as shown in fig. 18 and 19, a first optical transparent adhesive layer 11 is disposed on a surface of the light guide layer 60 close to the cover plate 2, and the first optical transparent adhesive layer 11 is planar.

Optionally, the light guide layer 60 is disposed between the cover plate 2 and the upper polarizer 34, as shown in fig. 20 and 21, a first optical transparent adhesive layer 11 is disposed on a surface of the light guide layer 60 close to the cover plate 2, and the first optical transparent adhesive layer 11 is annular.

Optionally, the light guide layer 60 is disposed between the cover plate 2 and the upper polarizer 34, as shown in fig. 19 and 20, a second optical transparent adhesive layer 12 is disposed on a surface of the light guide layer 60 close to the upper polarizer 34, and the second optical transparent adhesive layer 12 is planar.

Optionally, the light guide layer 60 is disposed between the cover plate 2 and the upper polarizer 34, as shown in fig. 18 and 21, a second optical transparent adhesive layer 12 is disposed on a surface of the light guide layer 60 close to the upper polarizer 34, and the second optical transparent adhesive layer 12 is annular.

When the first optically transparent adhesive layer 11 is planar, the layer structure on the upper side of the light guide layer 60 is optically transparent adhesive; when the first optical transparent adhesive layer 11 is annular, the region surrounded by the annular first optical transparent adhesive layer 11 on the upper side of the light guide layer 60 is air. Similarly, when the second optically transparent adhesive layer 12 is planar, the layer structure on the lower side of the light guide layer 60 is optically transparent adhesive; when the second optical transparent adhesive layer 12 is annular, the region surrounded by the annular second optical transparent adhesive layer 12 under the light guide layer 60 is air.

Optionally, the light guide layer 60 is bonded to the cover plate 2 through the first optically transparent adhesive layer 11.

The first optical transparent adhesive layer 11 is used for bonding the packaging cover plate 2 while ensuring that light is totally reflected in the light guide layer 60, and a separate adhesive layer is not required, so that the liquid crystal display device is light and thin.

Optionally, light guiding layer 60 is bonded to upper polarizing layer 34 by second optically clear adhesive layer 12.

The second optical transparent adhesive layer 12 is used for adhering the upper polarizing layer 34 and the light guiding layer 60 while ensuring total reflection of light in the light guiding layer 60, and no adhesive layer is required to be separately arranged, so that the liquid crystal display device is light and thin.

Hereinafter, the liquid crystal display device provided in the present application will be schematically described with reference to a plurality of examples.

Example 1

As shown in fig. 22, the liquid crystal display device includes a backlight module 4, a liquid crystal display module 3 and a cover plate 2, wherein the liquid crystal display module 3 includes a display panel 30, an upper polarizing layer 34 and a lower polarizing layer 35, the lower polarizing layer 35 is close to the backlight module 4, and the upper polarizing layer 34 is close to the cover plate 2.

The liquid crystal display device further includes: light guide layer 60, fingerprint collection structure 7, collimated light source 81, first optics transparent adhesive layer 11 and second optics transparent adhesive layer 12.

The fingerprint collection structure 7 is used for receiving the reflected light of the light emitted by the light guide layer 60 and collecting fingerprints; the fingerprint collection structure 7 is located on one side of the black matrix 322 close to the second substrate 321, and along the thickness direction of the liquid crystal display device, the projection of the black matrix 322 covers the projection of the fingerprint collection structure 7.

Light guide layer 60 and fingerprint collection structure 7 are located between lower polarized layer 35 and cover plate 2, and fingerprint collection structure 7 is located light guide layer 60 and keeps away from cover plate 2 one side.

The light guide layer 60 is positioned between the upper polarizing layer 34 and the cover plate 2, and the light emitting surface of the light guide layer 60 faces the cover plate 2; as shown in fig. 23 and 24, the surface of the light guide layer 60 away from the cover plate 2 is provided with a first diffraction grating 64; the light guide layer 60 includes a first region 61 and a second region 62, the first diffraction grating 64 is located in the first region 61, the first region 61 is located in the display region 10 of the liquid crystal display device, and the second region 62 is located in the non-display region 20 of the liquid crystal display device.

The collimated light source 81 is used for emitting collimated light of a second angle and emitting the collimated light into the second area 62; the second region 62 is used for adjusting a second angle of the collimated light emitted by the collimated light source 81 to a third angle and emitting the collimated light to the first region 61; the third angle of collimated light is used for total reflection within the first region 61.

The first diffraction grating 64 is for allowing the diffracted 1 st order diffracted light of the collimated light of the third angle incident on the first diffraction grating 64 to exit the light guide layer 60; in the case where the light emitted from the collimated light source 81 is visible light, the 1 st order diffracted light is used for total reflection on the surface of the cover plate 2 away from the liquid crystal display module 3.

The first optically clear adhesive layer 11 is disposed between the light guiding layer 60 and the cover plate 2 for bonding the two.

A second optically clear adhesive layer 12 is disposed between the light directing layer 60 and the upper polarizing layer 34 for bonding the two.

Since the first region 61 of the light guide layer 60 is located in the display region 10, the first region 61 transmits light.

The second region 62 is provided in the light guide layer 60 in order that the collimated light of the second angle emitted from the collimated light source 81 cannot satisfy the requirement of total reflection after being incident on the first region 61, and therefore, after the light path conversion is performed through the second region 62, the angle of the collimated light is adjusted to the third angle at which the total reflection can occur in the first region 61. The structure of the second region 62 may be, for example, a coupling grating, a light guide, or the like.

To enable full screen pre-fingerprinting, as shown in fig. 23, optionally the first area 61 covers the display area 10.

In order to reduce the proportion of the non-display area 20, the second area 62 may optionally cover the projection of the collimated light source 81 in the thickness direction of the liquid crystal display device. The collimated light source 81 may be provided in parallel with the light guide layer 60, or may be provided obliquely below the light guide layer 60.

Through setting up collimated light source 8 to collimated light source 81, after the collimated light that collimated light source 81 exited jets into leaded light layer 60, the area of giving out light of leaded light layer 60 is great, can realize the leading fingerprint identification of great region.

Example two

Example two differs from example one in that:

as shown in fig. 25, the liquid crystal display device includes the collimated light source 8 as a collimated light point source 82.

As shown in fig. 26 and 27, the surface of the light guide layer 60 away from the cover plate 2 is provided with a first diffraction grating 64 and a second diffraction grating 65; the light guide layer 60 includes a first region 61, a second region 62, and a third region 63, and the first diffraction grating 64 is located at the first region 61, and the second diffraction grating 65 is located at the third region 63.

The non-display area 20 of the liquid crystal display device is located outside the display area 10, and the first area 61 is located at least in the display area 10, it can be understood that, as shown in fig. 29a, the first area 61 covers the display area 10, and the third area 63 is located in the non-display area 20; alternatively, as shown in fig. 29b, both the first area 61 and the third area 63 are located in the display area 10.

The collimated light point source 82 is used for emitting collimated light of a second angle and emitting the collimated light into the second area 62; the second region 62 is used for adjusting the second angle of the collimated light emitted by the collimated light point light source 82 to a third angle and emitting the collimated light into the third region 63; the third angle of collimated light is used to cause total reflection within the third region 63 after entering the third region 63.

The second diffraction grating is configured to cause the diffracted collimated light of the 1 st order diffracted collimated light of the third angle incident on the second diffraction grating 65 to enter the first region 61, and to cause total reflection in the first region 61; the first diffraction grating 64 is for causing 1 st order diffracted collimated light of the third angle collimated light incident on the first diffraction grating 64 to exit the light guide layer 60; in the case where the light emitted from the collimated light point light source 82 is visible light, the 1 st order diffracted light is used for total reflection on the surface of the cover plate 2 away from the liquid crystal display module 3.

As shown in fig. 25, the collimated light point light source 82 is disposed on the side of the light guide layer 60 away from the cover plate 2. The projection of the collimated light point source 82 overlaps the second region 62, for example, in the thickness direction of the liquid crystal display device. Alternatively, the collimated light point light source 82 is disposed on the back surface of the backlight module 4, and collimated light emitted from the collimated light point light source 82 is incident on the second region 62 through the light path converter 9.

As can be seen from the above description, as shown in fig. 26, the second region 62 of the light guide layer 60 is used for light path conversion, and adjusts the collimated light emitted from the collimated light point light source 82 to a proper angle (i.e., the second angle). The third region 63 of the light guiding layer 60 functions as a line light source, and light emitted from the collimated light point light source 82 is converted in angle by the second region 62, and then guided forward in the third region 63 and emitted to the first region 61. Thus, for the first region 61, it is equivalent to have one line light source to inject collimated light into the first region 61. The first region 61 of the light guide layer 60 is used for emitting light for fingerprint collection, and converting a line light source of the third region 63 into a surface light source, so that the area of a fingerprint identification region is increased.

Here, for the first region 61 and the third region 63, both provided with diffraction gratings, as shown in fig. 28, the lengths of the period d and the height h of the diffraction gratings are both in the order of hundreds of nanometers. By adjusting the period d and the height h, in combination with the angle of collimated light incident into the diffraction grating, the emission directions of 0 order diffracted light and 1 order diffracted light can be adjusted, so that collimated light of the third region 63 is incident into the first region 61, light of the first region 61 is emitted, and light transmission is realized.

As shown in fig. 29a, the second region 62 and the third region 63 are both located in the non-display region 20, and the first region 61 covers the display region 10 in the thickness direction of the liquid crystal display device. And in the first direction, the third region 63 is located on one side of the second region 62; in the second direction, the first region 61 is located on one side of the third region 63; wherein the first direction and the second direction are the length and width directions of the display panel 30. The positional relationship among the first region 61, the second region 62, and the third region 63 in fig. 29a and 29b is merely illustrative and not limited.

It is understood that, in the second example, from the perspective of fig. 29a, the first region 61 is located on one side of the third region 63 in the second direction, but if the second direction is opposite to the direction illustrated in the drawing, the first region 61 cannot be located in the display region 10, and therefore, the second direction is a direction in which the third region 63 faces the display region 10; similarly, the third region 63 is located on one side of the second region 62 along the first direction, but if the first direction is opposite to the illustrated direction, the third region 63 is located in the non-display region 20, but the first region 61 cannot be located in the display region 10, so the first direction is the direction from the second region 62 to the display region 10.

In the perspective of fig. 29b, the first region 61 is located on one side of the third region 63 in a second direction, which may be the direction illustrated in the figure or the direction opposite to the direction illustrated in the figure; similarly, the third region 63 is located on one side of the second region 62 along the first direction, but if the first direction is opposite to the illustrated direction, the third region 63 is located in the non-display region 20, but the first region 61 cannot be located in the display region 10, so the first direction is the direction from the second region 62 to the display region 10.

The non-display area 20 is located outside the display area 10, and the non-display area 20 may be disposed around the display area 10 by one turn or may be located on only several sides of the display area 10.

By setting the collimated light source 8 as the collimated light point light source 82 and converting the point light source into the line light source through the third region 63 in the light guide layer 60, the volume of the collimated light point light source 82 is smaller than that of the collimated light source 8 as the collimated light line light source 81, the occupation ratio of the collimated light source 8 in the non-display region 20 can be reduced, and the requirement for the integration degree of the components of the non-display region 20 can be reduced.

Example three

Example three differs from example two in that:

as shown in fig. 30a and 30b, the outline of the display area 10 includes a groove, the non-display area 20 includes a protruding area 21, and the protruding area 21 is spliced with the groove; the second region 62 is located in the projection region 21, and the first region 61 and the third region 63 are located at least in the display region 10.

As shown in fig. 31 and 32, the liquid crystal display module 3 is provided with a first opening 36 and the backlight module 4 is provided with a second opening 45 along a direction perpendicular to the thickness direction of the liquid crystal display device, and the projection of the protruding region 21 coincides with the projection of the first opening 36 and the projection of the second opening 45 along the thickness direction of the liquid crystal display device.

The liquid crystal display device further includes a front optical device 13, and the front optical device 13 and the collimated light point light source 82 are both disposed in the space formed by the first opening 36 and the second opening 45.

It should be noted that the shape and the arrangement position of the groove and the protruding area 21 are not limited in this example, and fig. 31 is only an illustration, but in any shape, the contour of the protruding area 21 and the contour of the groove are overlapped, so that the protruding area 21 and the groove are seamlessly spliced.

It is to be understood that, in example three, as shown in fig. 30b, at the position where the convex region 21 is located near the corner, the first region 61 is located on the side of the third region 63 in the second direction, which is the direction in which the third region 63 faces the display region 10, as in example two; as shown in fig. 30a, in the case where the convex region 21 is located away from the corner, the second direction may be the direction in fig. 30a, and the second direction may also be the opposite direction to the direction illustrated in the drawing. Similarly, the third region 63 is located on one side of the second region 62 along the first direction, but if the first direction is opposite to the direction illustrated in the figure, the third region 63 cannot be located in the display region 10, and therefore, the first direction is a direction from the second region 62 to the display region 10.

The first region 61 may be located only in the display region 10, and the first region 61 may also extend to the protruding region 21, and may be reasonably arranged according to a specific structure.

The protruding region 21 of the non-display area 20 coincides with the projection of the first opening 36 and the projection of the second opening 45 along the thickness direction of the liquid crystal display device, that is, the contour of the first opening 36, the contour of the second opening 45, and the contour of the groove coincide with each other along the thickness direction of the liquid crystal display device.

It is understood that the front optical device 13 and the collimated light point light source 82 are both disposed in the gap formed by the first opening 36 and the second opening 45, and since the light paths of the front optical device 13 and the collimated light point light source 82 are both toward the cover plate 2, they should be disposed side by side in the direction perpendicular to the thickness direction of the liquid crystal display device. And the projection of the lighting structure of the front optical device 13 and the projection of the light guide layer 60 do not overlap in the thickness direction of the liquid crystal display device.

Since the light guide layer 60 has a function of changing the light path, the light path above the lighting structure of the front optical device 13 should not be blocked so as not to affect the effect, and therefore, the light guide layer 60 should not be disposed above the lighting structure of the front optical device 13.

The front optical device 13 may be, for example, a front camera, an ambient light collector, or the like.

The front camera generally includes a housing (housing), a lens (lens), an infrared filter (IR cut filter), an image sensor (image sensor), and a Flexible Printed Circuit Board (FPCB), and the lens is used as a lighting structure of the front camera.

Since the front camera has a small cross-sectional area at the lens, as shown in fig. 32, the front optical device 13 may alternatively include a front camera, and the collimated light point light source 82 is disposed in a gap between the lens of the front camera and the liquid crystal display module 3.

Since the cross-sectional area of the front camera where the infrared filter, the image sensor, and the flexible printed circuit board are located below the lens is large, as shown in fig. 32, the projection of the portion of the front camera where the cross-sectional area is large overlaps with the projection of the collimated light point light source 82 in the thickness direction of the liquid crystal display device, even covers the projection of the collimated light point light source 82.

The first optically transparent adhesive layer 11 and the second optically transparent adhesive layer 12 may or may not extend to the protruding region 21. Illustratively, the first optical transparent adhesive layer 11 and the second optical transparent adhesive layer 12 are both provided with openings corresponding to the first opening 36 and the second opening 45, and the first optical transparent adhesive layer 11 and the second optical transparent adhesive layer 12 do not shield the first opening 36 and the second opening 45.

By making the non-display area 20 include the convex area 21, and the front optical device 13 and the collimated light point light source 82 are provided in the convex area 21, the area of the non-display area 20 located outside the display area 10 can be reduced, and the screen ratio of the liquid crystal display device can be further increased.

Example four

Example four differs from example three in that:

as shown in fig. 33, the third region 63 includes a first sub region 631 and a second sub region 632; in the first direction, the first sub-area 631 and the second sub-area 632 are respectively located at both sides of the second area 62; in the second direction, the first region 61 is located on the same side of the first sub-region 631, the second sub-region 632, and the second region 62; wherein the first direction and the second direction are the length and width directions of the display panel 30.

In order to increase the area of the fingerprint identification area, as shown in fig. 33, in some embodiments, the first region 61 extends to the edge of the display region 10 in the second direction.

By having the third region 63 include the first sub-region 631 and the second sub-region 632, the first sub-region 631 and the second sub-region 632 are respectively located on both sides of the second region 62, and the arrangement in this example can increase the area of the fingerprint identification region compared to arranging the third region 63 only on one side of the second region 62.

Example five

Example five differs from example two in that:

as shown in fig. 34, the non-display area 20 includes a light-transmitting area 22 and a light-blocking area 23, and the display area 10 surrounds the light-transmitting area 22; the opaque region 23 is located outside the display region 10; the second region 62 is located in the light-transmitting region 22, and the first region 61 and the third region 63 are located at least in the display region 10 in the thickness direction of the liquid crystal display device.

As shown in fig. 35 and 36, the first hollow-out region 14 is disposed on each film layer between the first substrate 311 and the second substrate 321 of the display panel 30; the lower polarizing layer 35 is provided with a second hollow-out area 15; the backlight module 4 is provided with a third hollow area 16; the light-transmitting area 22, the first hollow-out area 14, the second hollow-out area 15, and the third hollow-out area 16 coincide with each other along the thickness direction of the liquid crystal display device.

The liquid crystal display device further includes a front optical device 13, and the front optical device 13 and the collimated light point light source 82 are disposed in the third hollow area 16.

Note that the shape and the arrangement position of the light-transmitting region 22 are not limited in this example, and fig. 35 is merely an illustration.

The film layers located between the first substrate 311 and the second substrate 321 include, for example, a TFT, a pixel electrode 313, a common electrode 314, a first insulating layer 315, a second insulating layer 316, a black matrix 322, a color filter layer 323, a fingerprint collection structure 7, a liquid crystal layer 33, and the like, and each film layer is provided with a first hollow area 14 to avoid blocking light.

The first region 61 and the third region 63 are located at least in the display region 10, which means that the first region 61 and the third region 63 may be located only in the display region 10, and the first region 61 and the third region 63 may also extend from the display region 10 to the non-display region 20. The first region 61 and the third region 63 are located in the display region 10, which does not mean that the sum of the first region 61 and the third region 63 covers the display region 10, as shown in fig. 36, a part of the region in the display region 10 may not be provided with the light guide layer 60.

Since there are no hollow-out areas on the first substrate 311, the front optical device 13 and the collimated light point light source 82 can only extend into the third hollow-out area 16 of the backlight module 4.

In addition, in general, the cross-sectional area of the front camera tends to gradually increase as a whole along the direction from the display panel 30 to the backlight module 4, and the cross-sectional area of the lens of the front camera is smaller. In order to reduce the ratio of the front-end optical device 13 to the collimated light point light source 82, in some embodiments, the front-end optical device 13 includes a front-end camera, and the collimated light point light source 82 is disposed in a gap between a lens of the front-end camera and the liquid crystal display module 3.

That is, as shown in fig. 36, the collimated light point light source 82 is disposed in the gap between the lens of the front camera and the backlight unit 4.

The display region 10 surrounds the light-transmitting region 22 by making the non-display region 20 include the light-transmitting region 22, so that the display device realizes a full-screen display. On this basis, through with the reasonable setting of leaded light layer 60 in comprehensive screen display device, make comprehensive screen display device can realize fingerprint discernment under the screen.

Example six

Example six differs from example five in that:

as shown in fig. 37, the second hollow-out region 15 is not provided on the lower polarizing layer 35, and the second hollow-out region 15 is provided on the upper polarizing layer 34.

The second hollow-out area 15 is arranged on at least one polarizing layer, so that the situation that the light collecting structure of the front optical device 13 cannot collect light due to the fact that the upper polarizing layer 34 and the lower polarizing layer 35 filter light together can be avoided.

Example seven

Example seven differs from example five in that:

as shown in fig. 38, the upper polarizing layer 34 is also provided with a second hollow-out region 15, and the second hollow-out region 15 is filled with an optically transparent adhesive 151.

As shown in fig. 39, the light guide layer 30 does not cover the display region 10, the liquid crystal display device further includes a transparent adhesive filling layer 17, the transparent adhesive filling layer 17 and the light guide layer 60 are disposed on the same layer, the thickness of the transparent adhesive filling layer 17 is equal to the thickness of the light guide layer 60, and the transparent adhesive filling layer 17 is spliced with the light guide layer 60; wherein, along the thickness direction of the liquid crystal display device, the projection of the transparent adhesive filling layer 17 is overlapped with the light-transmitting area 22.

The projection of the transparent adhesive filling layer 17 overlaps the transparent area 22, which can be understood as the projection of the transparent adhesive filling layer 17 partially overlapping the transparent area 22, and can also be understood as the projection of the transparent area 22 covering the transparent adhesive filling layer 17.

The thickness of the optically transparent adhesive 151 filled in the second hollow-out area 15 of the upper polarizing layer 34 is the same as that of the upper polarizing layer 34, and the thickness of the optically transparent adhesive 151 filled in the second hollow-out area 15 of the lower polarizing layer 35 is the same as that of the lower polarizing layer 35.

The transparent adhesive filling layer 17 may be only located in the transparent region 22, or may extend to the non-transparent region 22.

By filling the optical transparent adhesive 151 in the upper polarizing layer 34 and the lower polarizing layer 35, and by providing the transparent adhesive filling layer 17 on the same layer as the light guiding layer 60, the refraction of light can be reduced, and the deformation of the first substrate 311 and the second substrate 321 can be reduced.

Example eight

Example eight differs from example five in that:

as shown in fig. 40 and 41, the third region 63 includes a first sub region 631 and a second sub region 632; in the first direction, the first sub-area 631 and the second sub-area 632 are respectively located at both sides of the second area 62; in the second direction, the first region 61 is located on the same side of the first sub-region 631, the second sub-region 632, and the second region 62; wherein the first direction and the second direction are the length and width directions of the display panel 30.

The above description is only for the specific embodiments of the present application, but the scope of the present application is not limited thereto, and any person skilled in the art can easily conceive of the changes or substitutions within the technical scope of the present application, and shall be covered by the scope of the present application. Therefore, the protection scope of the present application shall be subject to the protection scope of the claims.

Claims

1. A liquid crystal display device comprises a backlight module, a liquid crystal display module and a cover plate, wherein the liquid crystal display module comprises a display panel, an upper polarizing layer and a lower polarizing layer, the lower polarizing layer is close to the backlight module, and the upper polarizing layer is close to the cover plate; characterized in that, the liquid crystal display device further comprises: a collimated light emitting structure and a fingerprint collecting structure;

the collimated light emergent structure and the fingerprint collecting structure are positioned between the lower polarized light layer and the cover plate, and the fingerprint collecting structure is positioned on one side of the collimated light emergent structure, which is far away from the cover plate;

the light emitting surface of the collimated light emitting structure faces the cover plate, the collimated light emitting structure is at least located in the display area of the liquid crystal display device, and the part, located in the display area, of the collimated light emitting structure is transparent;

the angle of collimated light emitted from the collimated light emitting structure is a first angle, and the collimated light of the first angle is used for total reflection on the surface, far away from the liquid crystal display module, of the cover plate;

the fingerprint collection structure is used for receiving the reflected light of the collimated light of the first angle emitted by the collimated light emergent structure.

2. The liquid crystal display device according to claim 1, wherein the display panel comprises a black matrix, and a projection of the black matrix covers a projection of the fingerprint collection structure in a thickness direction of the liquid crystal display device.

3. The liquid crystal display device of claim 1, wherein the fingerprint collection structure is integrated within the display panel.

4. The liquid crystal display device according to claim 2, wherein the display panel further comprises an array substrate and a counter substrate disposed opposite to the array substrate, the black matrix being disposed on the counter substrate;

the fingerprint collection structure is arranged on one side, far away from the array substrate, of the black matrix.

5. The liquid crystal display device of claim 1, wherein the fingerprint acquisition structure is disposed between the upper polarizing layer and the cover plate.

6. The liquid crystal display device according to claim 2 or 4, wherein the display panel includes a plurality of sub-pixel units, and the black matrix is located between any adjacent sub-pixel units;

the fingerprint collection structure comprises a plurality of fingerprint collection units, the fingerprint collection units correspond to sub-pixel groups one to one, each sub-pixel group comprises at least one sub-pixel unit, and the sub-pixel units are different and comprise in the sub-pixel groups.

7. The liquid crystal display device of claim 1, wherein the collimated light exit structure is disposed between the upper polarizing layer and the cover plate.

8. The liquid crystal display device according to claim 1, wherein the collimated light exit structure is a collimated light surface light source.

9. The liquid crystal display device according to claim 8, wherein a projection of the collimated light surface light source covers the display region in a thickness direction of the liquid crystal display device.

10. The liquid crystal display device according to claim 1, wherein the collimated light exit structure is a light guide layer, and a surface of the light guide layer away from the cover plate is provided with a first diffraction grating;

the light guide layer comprises a first area, and the first diffraction grating is positioned in the first area;

the liquid crystal display device also comprises a collimated light source; the collimated light source is used for emitting collimated light into the light guide layer, and the collimated light is totally reflected in the first area;

the first diffraction grating is used for enabling collimated light emitted to the first diffraction grating to be diffracted to 1 st-order diffracted light to be emitted out of the light guide layer;

the collimated light source is positioned in a non-display area of the liquid crystal display device, or the collimated light source is positioned on one side, away from the liquid crystal display module, of the backlight module;

the collimated light source is a collimated light point source or a collimated light line source.

11. The liquid crystal display device according to claim 10, wherein the collimated light source is a collimated light line source;

the light guide layer further comprises a second region;

the collimated light source is used for emitting collimated light of a second angle and emitting the collimated light into the second area;

the second area is used for adjusting a second angle of collimated light emitted by the collimated light source into a third angle and emitting the third angle into the first area.

12. The liquid crystal display device according to claim 10, wherein the collimated light source is a collimated light point source;

the light guide layer further comprises a second region and a third region; the surface of the light guide layer, which is far away from the cover plate, is also provided with a second diffraction grating; the second diffraction grating is located at the third zone;

the collimated light point light source is used for emitting collimated light of a second angle and emitting the collimated light into the second area;

the second area is used for adjusting a second angle of collimated light emitted by the collimated light point light source into a third angle and emitting the third angle into the third area, and the collimated light of the third angle is used for generating total reflection in the third area after being emitted into the third area;

the second diffraction grating is used for enabling the collimated light emitted to the second diffraction grating to be incident into the first area through diffracted 1-order diffraction collimated light;

the collimated light point light source is arranged on one side, far away from the cover plate, of the light guide layer.

13. The liquid crystal display device according to claim 12, wherein the non-display region is located outside the display region;

the second area and the third area are both located in the non-display area, and the first area covers the display area.

14. The liquid crystal display device according to claim 12, wherein the non-display region is located outside the display region; the outline of the display area comprises a groove, the non-display area comprises a protruding area, and the protruding area is spliced with the groove;

the second region is located in the protruding region, and the first region and the third region are located at least in the display region.

15. The liquid crystal display device according to claim 12, wherein the non-display region includes a light-transmitting region and a light-blocking region, and the display region surrounds the light-transmitting region; the light-proof area is positioned at the outer side of the display area;

the second region is located in the light-transmitting region, and the first region and the third region are at least located in the display region.

16. The liquid crystal display device according to any one of claims 13 to 15, wherein the third region is located on one side of the second region in the first direction; the first region is located on one side of the third region along a second direction;

wherein the first direction and the second direction are the length and width directions of the display panel.

17. The liquid crystal display device according to claim 14 or 15, wherein the third region includes a first sub region and a second sub region;

along a first direction, the first sub-area and the second sub-area are respectively positioned at two sides of the second area; along a second direction, the first region is located on the same side of the first sub-region, the second sub-region and the second region;

18. The liquid crystal display device according to claim 17, wherein the first region extends to an edge of the display region in the second direction.

19. The liquid crystal display device according to claim 10, wherein the collimated light source is arranged on the side of the backlight module far away from the liquid crystal display module;

the liquid crystal display device further comprises a light path converter; the light path converter is positioned in the non-display area;

the light path converter is used for enabling the collimated light source to emit the collimated light of the light path converter to enter the light guide layer.

20. The lcd apparatus of claim 14, wherein the lcd module has a first opening and the backlight module has a second opening along a direction perpendicular to a thickness direction of the lcd apparatus, and the projection of the protrusion coincides with a projection of the first opening and a projection of the second opening along the thickness direction of the lcd apparatus;

the liquid crystal display device further comprises a front optical device, and the front optical device and the collimated light source are arranged in a gap formed by the first opening and the second opening.

21. The liquid crystal display device according to claim 15, wherein a first hollow area is provided in each film layer between the first substrate and the second substrate on the surface of the display panel;

a second hollow-out area is arranged on the lower light polarizing layer and/or the lower light polarizing layer;

a third hollow area is arranged on the backlight module;

the light-transmitting area, the first hollowed-out area, the second hollowed-out area and the third hollowed-out area are overlapped;

the liquid crystal display device further comprises a front optical device, and the front optical device and the collimated light source are both arranged in the third hollow area.

22. The lcd device of claim 20 or 21, wherein the front-facing optics comprise a front-facing camera, and the collimated light source is disposed in a gap between a lens of the front-facing camera and the lcd module.

23. The lcd device of claim 21, wherein the second hollowed-out area is filled with an optically clear adhesive.

24. The lcd device of claim 21, further comprising a transparent adhesive filling layer, wherein the transparent adhesive filling layer and the light guide layer are disposed on the same layer, the thickness of the transparent adhesive filling layer is equal to the thickness of the light guide layer, and the transparent adhesive filling layer is spliced with the light guide layer;

and the projection of the transparent adhesive filling layer is overlapped with the light-transmitting area along the thickness direction of the liquid crystal display device.

25. The lcd apparatus of any one of claims 10 to 15, wherein a first optically transparent adhesive layer is disposed on a surface of the light guide layer adjacent to the cover plate, and the first optically transparent adhesive layer is planar or annular;

and/or;

and a second optical transparent adhesive layer is arranged on the surface, close to the upper polarizing layer, of the light guide layer, and the second optical transparent adhesive layer is planar or annular.

26. The liquid crystal display device according to claim 1, wherein the collimated light is visible light.