CN112578591A

CN112578591A - Reflector plate and backlight module

Info

Publication number: CN112578591A
Application number: CN201910939233.0A
Authority: CN
Inventors: 程显荣; 张传伟; 崔鲁贵; 马栋栋
Original assignee: BOE Technology Group Co Ltd; Gaochuang Suzhou Electronics Co Ltd
Current assignee: BOE Technology Group Co Ltd; Gaochuang Suzhou Electronics Co Ltd
Priority date: 2019-09-29
Filing date: 2019-09-29
Publication date: 2021-03-30

Abstract

A reflective sheet and a backlight module including the same are provided. The reflective sheet includes: a reflector sheet main body; a reflective flap structure comprising at least one reflective flap; and a connecting portion, wherein the connecting portion connects the reflection flap of the reflection flap structure to the reflection sheet main body so that the reflection flap of the reflection flap structure can be folded with respect to the reflection sheet main body, and yellow ink is provided on at least one surface of the reflection flap.

Description

Reflector plate and backlight module

Technical Field

The disclosure relates to the technical field of display, in particular to a reflector plate and a backlight module.

Background

In a backlight unit of a display device, it is necessary to position and mount optical elements such as a reflective sheet, a light guide plate, an optical film, and the like on a back plate. With the continuous development of display technologies, display devices are developing towards ultra-thin, narrow-bezel and bezel-less. In the ultra-thin, narrow-frame and frameless display devices, how to achieve uniformity of brightness and color of light rays of the backlight module at the frame position is one of important subjects studied by research personnel.

Disclosure of Invention

In order to solve at least one aspect of the above problems, embodiments of the present disclosure provide a reflective sheet and a backlight module.

In one aspect, there is provided a reflective sheet, including:

a reflector sheet main body;

a reflective flap structure comprising at least one reflective flap; and

a connecting part which is connected with the connecting part,

wherein the connecting portion connects the reflection flap of the reflection flap structure to the reflection sheet main body such that the reflection flap of the reflection flap structure can be folded with respect to the reflection sheet main body,

yellow ink is disposed on at least one surface of the reflective flap.

For example, the reflector flap structure comprises a first reflector flap structure and a second reflector flap structure, the first and second reflector flap structures being located at 2 corners of the reflector sheet body, respectively.

For example, the reflector main body includes a first side surface, a second side surface and a third side surface, the second side surface and the third side surface are oppositely arranged, the first side surface connects the second side surface and the third side surface,

each of the first and second reflection flap structures includes 2 reflection flaps, one reflection flap of the first reflection flap structure is connected to the first side surface of the reflection sheet main body through one of the connection portions, the other reflection flap of the first reflection flap structure is connected to the second side surface of the reflection sheet main body through one of the connection portions, one reflection flap of the second reflection flap structure is connected to the first side surface of the reflection sheet main body through one of the connection portions, and the other reflection flap of the second reflection flap structure is connected to the third side surface of the reflection sheet main body through one of the connection portions.

For example, the connecting portion includes a plurality of solid portions and a plurality of broken portions, which are alternately arranged in order.

In another aspect, a backlight module is provided, including:

a back panel comprising a bottom panel and a plurality of side panels connected to the bottom panel;

the above-mentioned reflective sheet;

a light guide plate;

an optical film having a plurality of optical layers,

the reflecting sheet, the light guide plate and the optical diaphragm are sequentially stacked on the bottom plate of the back plate.

For example, the backlight module further comprises an elastic element arranged between the light guide plate and the side plate,

wherein at least a side portion of the elastic member facing the light guide plate is set to be yellow.

For example, the reflection flap is folded toward the light guide plate with respect to the reflection sheet body, and the yellow ink is coated on a surface of the reflection flap facing the light guide plate.

For example, the light guide plate includes:

the light guide plate comprises a light guide plate body and a light source, wherein the light guide plate body comprises a light emergent surface and a plurality of side surfaces connected with the light emergent surface; and

a lug structure protruding from a side surface of the light guide plate body,

wherein the lug structure comprises a convex surface, a first transition part and a second transition part, the convex surface is parallel to the side surface of the light guide plate main body, the first transition part and the second transition part are connected with the side surface of the light guide plate main body and the convex surface,

first transition portion with each in the second transition portion all includes first circular arc portion, rake and second circular arc portion, first circular arc portion is connected the side of light guide plate main part with the rake, the rake is connected first circular arc portion with second circular arc portion, second circular arc portion is connected the rake with the convex surface.

For example, one end of the first arc part is tangent to the side surface of the light guide plate main body, and the other end is tangent to the inclined part;

one end of the second arc part is tangent to the convex surface, and the other end of the second arc part is tangent to the inclined part.

For example, the size of the reflection flap along the light exit direction of the backlight module is larger than the size of the light guide plate along the light exit direction of the backlight module.

For example, the radius of the first circular arc portion is larger than the radius of the second circular arc portion.

For example, the radius of the first circular arc part is within the range of 80-100 mm, and/or the radius of the second circular arc part is within the range of 30-50 mm.

For example, the inclination angle of the inclined portion with respect to the convex surface is in the range of 4 ° to 6 °.

For example, the light guide plate further includes a plurality of protrusions disposed on a bottom surface of the light guide plate body, the bottom surface being opposite to the light emitting surface of the light guide plate, the plurality of protrusions for scattering light incident thereon,

the light guide plate is characterized in that a plurality of light sparse areas and a plurality of light dense areas are formed on the light emitting surface of the light guide plate, and the distribution density of the plurality of protrusions in the area on the bottom surface corresponding to the light sparse areas is greater than that of the plurality of protrusions in the area on the bottom surface corresponding to the light dense areas.

For example, orthographic projections of the reflection flap structure of the reflection sheet, the elastic element and the lug structure of the light guide plate on the bottom plate of the back plate do not overlap with each other.

For example, the backlight module further includes a middle frame pressing the reflective sheet, the light guide plate, and the optical film sheet toward the bottom plate of the back plate,

the middle frame comprises a middle frame outer wall and a middle frame inner wall, the middle frame outer wall is positioned at one side of the side plate of the back plate far away from the light guide plate, the middle frame inner wall is positioned at one side of the side plate of the back plate close to the light guide plate,

the reflection folding piece structure of the reflection sheet, the elastic element, the lug structure of the light guide plate and the orthographic projection of the inner wall of the middle frame on the bottom plate of the back plate are not overlapped with each other.

For example, the backlight module further includes a backlight source disposed on one side of the light guide plate, and the backlight source includes a plurality of light emitting diodes, and the light emitting diodes emit blue light.

For example, the optical film comprises a quantum dot film comprising a plurality of yellow quantum dots.

Through the reflector plate and the backlight module provided by the embodiment of the disclosure, the uniformity of the brightness and the color of the light of the backlight module at the position of the frame is realized.

Drawings

Other objects and advantages of the present disclosure will become apparent from the following description of the disclosure, which is made with reference to the accompanying drawings, and can assist in a comprehensive understanding of the disclosure.

Fig. 1 is a front view of a display device according to an embodiment of the present disclosure;

FIG. 2 is a schematic plan view of a backlight module according to an embodiment of the disclosure;

fig. 3 is a cross-sectional view of a backlight module according to an embodiment of the present disclosure taken along line AA' in fig. 2;

fig. 4 is a cross-sectional view of a backlight assembly according to an embodiment of the present disclosure taken along line BB' in fig. 2;

fig. 5 is a schematic structural diagram of a middle frame of a backlight module according to an embodiment of the disclosure;

fig. 6 is a partial enlarged view of a middle frame of the backlight module according to the embodiment of the disclosure at a part I in fig. 5;

fig. 7 is a plan view of a reflective sheet of a backlight module according to an embodiment of the present disclosure;

fig. 8 is a partial enlarged view of a reflective sheet of a backlight module according to an embodiment of the present disclosure at part II of fig. 7;

fig. 9 is a sectional view of the backlight module according to the embodiment of the disclosure taken along the position P1;

FIG. 10 is a schematic plan view of a light guide plate of a backlight module according to an embodiment of the disclosure;

FIG. 11 is a partial enlarged view of a light guide plate of a backlight module according to an embodiment of the present disclosure, showing a lug structure of the light guide plate;

FIG. 12 is a cross-sectional view of a backlight module according to an embodiment of the disclosure at the ledge structure;

FIG. 13 is a schematic view of light distribution of a light guide plate of a backlight module at a ledge structure according to an embodiment of the disclosure;

fig. 14 is a partial schematic view of a light guide plate according to an embodiment of the present disclosure, schematically illustrating a plurality of protrusions disposed on the light guide plate and light distribution on a light exit surface; and

fig. 15A to 15C respectively show 3 kinds of lug structures provided at the edge of the light guide plate in the related art.

It is noted that, for the sake of clarity, in the drawings used to describe embodiments of the present disclosure, the dimensions of layers, structures or regions may be exaggerated or reduced, i.e., the drawings are not drawn to scale.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present disclosure more apparent, the technical solutions of the embodiments of the present disclosure will be described clearly and completely with reference to the drawings of the embodiments of the present disclosure. It is to be understood that the described embodiments are only a few embodiments of the present disclosure, and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the described embodiments of the disclosure without any inventive step, are within the scope of protection of the disclosure.

Unless otherwise defined, technical or scientific terms used herein shall have the ordinary meaning as understood by one of ordinary skill in the art. The use of "first," "second," and similar terms in this disclosure is not intended to indicate any order, quantity, or importance, but rather is used to distinguish one element from another. The word "comprising" or "comprises", and the like, means that the element or item listed before the word covers the element or item listed after the word and its equivalents, but does not exclude other elements or items.

In this document, unless specifically stated otherwise, directional terms such as "upper", "lower", "left", "right", "inside", "outside", and the like are used to indicate orientations or positional relationships based on the orientation shown in the drawings, merely for convenience in describing the present disclosure, and do not indicate or imply that the referenced device, element, or component must have a particular orientation, be constructed or operated in a particular orientation. It should be understood that when the absolute positions of the described objects are changed, the relative positional relationships they represent may also change accordingly. Accordingly, these directional terms should not be construed as limiting the present disclosure.

Fig. 1 is a front view of a display device according to an embodiment of the present disclosure. It should be noted that, for convenience of description, an XYZ spatial coordinate system is established herein. Referring to fig. 1, the display device 1000 includes 4 bezels, i.e., a first bezel 1001 located at an upper side (also referred to as a day side) in fig. 1, a second bezel 1002 located at a left side in fig. 1, a third bezel 1003 located at a right side in fig. 1, and a fourth bezel 1004 located at a lower side (also referred to as a ground side) in fig. 1. . The display device 1000 further includes a display surface 1005 for displaying information such as text and images for a user to view. For example, in fig. 1, a plane parallel to the paper surface and facing the reader is the display surface 1005. For example, the X direction may be a direction parallel to the first bezel 1001 or the fourth bezel 1004, the Y direction may be a direction parallel to the second bezel 1002 or the third bezel 1003, and the Z direction may be a direction perpendicular to the display surface 1005, and in fig. 1, the Z direction is illustrated as a direction perpendicular to the paper surface. It should be noted that, in this document, the Y direction may also be referred to as a first direction, the Z direction may also be referred to as a second direction, and the X direction may also be referred to as a third direction. It should be noted that the expressions XYZ spatial coordinate system, X direction, Y direction, and Z direction are merely for convenience in describing the embodiment of the present disclosure, and should not be construed as limiting the present disclosure.

The display device 1000 may include a backlight module, which may include a back plate, a middle frame, a reflective sheet, a light guide plate, an optical film, an elastic member, and the like, which will be described in more detail below.

Fig. 2 is a schematic plan view of a backlight assembly according to an embodiment of the present disclosure, fig. 3 is a cross-sectional view of the backlight assembly according to an embodiment of the present disclosure taken along line AA 'in fig. 2, and fig. 4 is a cross-sectional view of the backlight assembly according to an embodiment of the present disclosure taken along line BB' in fig. 2.

Referring to fig. 2, the backlight module 100 is a side-in type backlight module, for example, it may include a light source 1 located on the ground side, and the light source 1 may be an LED light bar. More specifically, the LED light bar may include a plurality of blue light emitting LEDs (i.e., light emitting diodes) 11.

Referring to fig. 3 and 4, the backlight module 100 may further include a back plate 2, a middle frame 3, a reflective sheet 4, a light guide plate 6, an optical film 8, an elastic member 9, and the like. The rear plate 2 includes a bottom plate 21 and a plurality of side plates 22 connected to the bottom plate 21, the bottom plate 21 and the plurality of side plates enclosing a receiving cavity in which the components such as the reflection sheet 4, the light guide plate 6, the optical film 8, and the elastic member 9 can be placed. The middle frame 3 presses the components such as the reflecting sheet 4, the light guide plate 6, the optical diaphragm 8 and the like to the back plate 2, thereby realizing the assembly of the backlight module.

For example, the back plate 2 may have a unitary structure, i.e. the back plate 2 is a component made by a unitary moulding process. For example, a whole back plate blank may be formed by machining, stamping, and the like, and then the periphery of the back plate blank is bent by a bending process to form four side plates, respectively. For example, the back plate 2 may be made of a metal material such as iron, aluminum, stainless steel, or the like.

In an embodiment of the present disclosure, the optical film 8 may include a quantum dot film including a plurality of yellow quantum dots 82 (shown in fig. 3). In the backlight module 100, a part of the blue light emitted from the blue light emitting LED 11 is incident on the yellow quantum dots and converted into yellow light; the yellow light mixes with another portion of the blue light emitted by the LED 11 to form white light. Thus, the backlight assembly 100 is formed as a backlight assembly providing white light.

It should be noted that, in order to make the drawings more concise, only the quantum dots 82 are shown in fig. 3, and the quantum dots 82 are omitted in other drawings, but it is not meant that the backlight module in other embodiments does not include the quantum dots 82.

For example, the optical film 8 may further include an optical film such as a diffusion sheet and a brightness enhancement sheet, and it should be understood that the optical film may also include other types of optical films, and the types of the optical films included in the optical film may be selected according to the actual use requirement.

In the backlight module 100 according to the embodiment of the present disclosure, the light source 1 is located at one side of the light guide plate 6, and light emitted from the light source enters the light guide plate 6 from a side surface of the light guide plate 6, is emitted from a light emitting surface of the light guide plate 6 after optical actions such as multiple reflection and refraction of the reflective sheet 4, the light guide plate 6, and the like, and then passes through the optical film 8 to form a surface light source.

Herein, unless otherwise stated, referring to fig. 2-4 in combination, the Z direction is the light exit direction of the backlight module 100, and the upper surface of the light guide plate 6 shown in fig. 3 and 4 is the light exit surface of the light guide plate.

The structure of the middle frame will be described in more detail below with reference to the accompanying drawings.

Fig. 5 is a schematic structural diagram of a middle frame of a backlight module according to an embodiment of the disclosure, and fig. 6 is a partial enlarged view of the middle frame of the backlight module according to an embodiment of the disclosure at a part I in fig. 5. For example, the middle frame of the backlight module according to the embodiment of the present disclosure may have an inverted U-shape. Specifically, the middle frame 3 may have a first middle frame side surface 3A on the day side, a second middle frame side surface 3B on the left side, and a third middle frame side surface 3C on the right side.

Referring collectively to fig. 3-6, the middle frame 3 may include a middle frame outer wall 31, a middle frame inner wall 32, and a middle frame support surface 33. The middle frame outer wall 31 is located on one side of the side plate 22 of the back plate 2 away from the light guide plate 6, and the middle frame inner wall 32 is located on one side of the side plate 22 of the back plate 2 close to the light guide plate 6. With such an arrangement, the middle frame 3 can be connected with the back plate 2, and the optical film 8, the light guide plate 6, the reflective sheet 4 and other components accommodated in the accommodating cavity are pressed against the back plate 2, thereby realizing the assembly of the backlight module 100. For example, the middle frame supporting surface 33 is used for supporting a display panel, so as to facilitate the assembly of the backlight module 100 and the display panel.

Generally, the middle frame 3 is formed by a bending process. In order to avoid interference at the time of bending, the inner wall 32 of the middle frame at both corners of the middle frame (i.e., at the connecting position of the first middle frame side surface 3A and the second middle frame side surface 3B; at the connecting position of the first middle frame side surface 3A and the third middle frame side surface 3C) needs to be cut off partially. As shown in fig. 6, it is schematically shown that a part of the inner wall 32 of the middle frame at the connecting position of the first middle frame side surface 3A and the second middle frame side surface 3B is cut away. That is, at the left and right corners of the middle frame day side, a part of the middle frame inner wall 32 is cut off. Hereinafter, for convenience of description, a position at which a part of the inner frame wall 32 is cut off in this case will be referred to as a position P1.

Referring to fig. 4, the elastic member 9 is disposed between the side surface of the light guide plate 6 and the side plate 22 of the back panel 2, for example, the elastic member 9 may be made of an elastic material such as rubber. Thus, the light guide plate 6 is assembled to the back plate 2 in a manner of abutting against the elastic member 9, and the light guide plate 6 can be prevented from shaking, so that the defects of abnormal sound, scratching of optical films and the like caused by shaking of the light guide plate 6 can be avoided. Further, during the high temperature and high humidity test of the display device, and in the case that the display device is operated for a long time, the light guide plate 6 may be thermally expanded, and at this time, the elastic member 9 may be elastically deformed by the pressing of the light guide plate 6, for example, the elastic member 9 may be compressed to compensate for the thermal expansion amount of the light guide plate 6. Thus, the light guide plate 6 is not deformed and arched by the rigid pressing force, and display failure due to the deformation and arching of the light guide plate is avoided.

In the embodiment of the present disclosure, in order to provide the elastic elements 9, a portion of the middle frame inner wall 32 is cut out at a plurality of positions of each of the first middle frame side surface 3A, the second middle frame side surface 3B, and the third middle frame side surface 3C to place a plurality of elastic elements 9. As shown in fig. 6, a portion of the inner wall 32 of the middle frame at a position of the first middle frame side surface 3A is schematically shown to be cut away, as shown at position P2 in fig. 5. Illustratively, a part of the inner wall 32 of the middle frame at 5 spaced positions of the first middle frame side surface 3A is cut away to place 5 elastic members 9 on the upper side; a part of the inner wall 32 of the middle frame at 2 spaced positions of the second middle frame side face 3B is cut away to place 2 elastic members 9 on the left side; a part of the inner wall 32 of the middle frame at 2 spaced positions of the third middle frame side surface 3C is cut out to place 2 elastic members 9 on the right side. However, in other embodiments, more or fewer elastic elements 9 may be provided according to the size and positioning requirements of the light guide plate, and accordingly, a part of the inner wall of the bezel may be cut out at more or fewer positions or at different positions from the position shown in fig. 6. That is, at a plurality of intermediate positions at the non-corners of the upper, left and right sides of the middle frame, a part of the inner wall 32 of the middle frame is cut off. Hereinafter, for convenience of description, a position at which a part of the inner frame wall 32 is cut off in this case will be referred to as a position P2.

It should be understood that the above position P1 and the above position P2 do not overlap each other.

Referring to fig. 2 to 6 in combination, the inner frame wall 32 is present at most positions of the middle frame 3, and the inner frame wall 32 is cut away at the above-mentioned position P1 and position P2 of the middle frame 3. As shown in fig. 3, a part of the blue light L1' emitted from the light guide plate 6 may be absorbed or reflected by the inner frame wall 32 at a position where the inner frame wall 32 is present, while the blue light at a position where the inner frame wall 32 is cut off may not be absorbed or reflected by the inner frame wall 32, resulting in a problem that the color and brightness of the light emitted at the position where the inner frame wall 32 is cut off are not uniform with the color and brightness of the light emitted at the position where the inner frame wall 32 is present.

In order to make the color and brightness of light emitted at a position where the middle frame inner wall 32 is cut off uniform with the color and brightness of light emitted at a position where the middle frame inner wall 32 exists, the present disclosed embodiment proposes the following exemplary embodiments.

Fig. 7 is a plan view of a reflection sheet of a backlight assembly according to an embodiment of the present disclosure, fig. 8 is a partially enlarged view of the reflection sheet of the backlight assembly at part II of fig. 7 according to an embodiment of the present disclosure, and fig. 9 is a sectional view of the backlight assembly taken along the position P1 according to an embodiment of the present disclosure.

Referring collectively to fig. 7-9, the reflector sheet 4 can include a reflector sheet body 41 and a reflector flap structure 42. For example, the reflective flap structure 42 can include at least one reflective flap. The reflection sheet 4 further includes a connection portion 43, and the connection portion 43 is used for connecting the reflection sheet main body 41 and the reflection folding piece of the reflection folding piece structure 42.

As shown in fig. 7, the reflection sheet main body 41 has a planar sheet-like structure, and an orthogonal projection of the reflection sheet main body 41 in the light outgoing direction has a rectangular shape, that is, a projection of the reflection sheet main body 41 in the XY plane is rectangular. Thus, the reflection sheet main body 41 includes four

side surfaces

411, 412, 413, 414, and the four

side surfaces

411, 412, 413, 414 are respectively located on the top, left, right, and ground sides.

In this context, the expression "reflection flap" may mean a small piece of reflection sheet extending from or attached to the reflection sheet main body, which can be folded at an angle with respect to the reflection sheet main body, and thus it is called a "fold" sheet. Generally, an area of an orthographic projection of the reflection flap along the light exit direction is smaller than an area of an orthographic projection of the reflection sheet main body along the light exit direction.

In general, a yellow ink printed area 415, as indicated by double-slanted lines in fig. 7, is formed on each of the four

side surfaces

411, 412, 413, 414 of the reflection sheet main body 41. For example, the width of the yellow ink printing area 415 at each

side

411, 412, 413, 414 is about 10-30 mm extending from the side of the reflection sheet main body 41 toward the center of the reflection sheet main body 41. For example, the yellow ink in each yellow ink printing area 415 is dot-shaped, and the diameter of the dot-shaped yellow ink gradually decreases from the side surface of the reflection sheet main body 41 toward the center of the reflection sheet main body 41. By such an arrangement, the uniformity of the color of the white light provided by the backlight assembly 100 may be improved.

In an embodiment of the present disclosure, as shown in fig. 7, the reflector flap structure 42 includes a first reflector flap structure and a second reflector flap structure, which are respectively located at 2 corners of the reflector main body 41, for example, at two left and right corners in fig. 7. That is, the reflection flaps 42 are provided at both left and right corners of the side 411 of the reflection sheet main body 41. It should be understood that both left and right corners of the side 411 of the reflection sheet main body 41 correspond to the above-mentioned position P1 of the middle frame 3 when the reflection sheet 4 is assembled with the middle frame 3.

Specifically, each of the first and second reflective flap structures includes 2 reflective flaps, i.e., reflective flap 421 and reflective flap 422 in fig. 7. One of the reflective flaps 421 (on the day side) of the first reflective flap structure 42 located at the left corner is connected to the first side 411 of the reflector main body 41 by a connecting portion 43, and the other reflective flap 422 (on the left side) of the first reflective flap structure 42 is connected to the second side 412 of the reflector main body 41 by a connecting portion 43. One of the reflection flaps 421 (on the day side) of the second reflection flap structure 42 located at the right corner is connected to the first side 411 of the reflection sheet main body 41 by one connection portion 43, and the other reflection flap 422 (on the right side) of the second reflection flap structure 42 is connected to the third side 413 of the reflection sheet main body 41 by one connection portion 43.

For example, each of the first and second reflection flap structures includes each

reflection flap

421, 422 having a rectangular shape in a forward projection in a direction perpendicular to the reflection sheet main body (i.e., in a light exit direction), or each

reflection flap

421, 422 has a rectangular projection in the XY plane.

In embodiments of the present disclosure, each

reflective flap

421, 422 is filled with yellow ink. For example, the upper surface of each of the

reflective flaps

421, 422 is coated with yellow ink 425 (indicated by double-slanted lines in fig. 8). Here, the upper surface of the reflection flap is located on the same side of the reflection sheet 4 as the surface of the reflection sheet main body 41 provided with the yellow ink printed area 415. For example, the yellow ink 425 is applied over substantially the entire upper surface of each of the

reflective flaps

421, 422.

Alternatively, in other embodiments, the orthographic projection of each

reflective flap

421, 422 in the direction perpendicular to the reflective sheet body can have other shapes as well, such as a semi-circle, an arc, a triangle, a parallelogram, a wave, and the like.

Optionally, the yellow ink can also be coated on a portion of the upper surface of each of the

reflective flaps

421, 422. Also, the shape of the yellow ink 425 coated on each of the

reflective flaps

421, 422 may not conform to the shape of the corresponding reflective flap. For example, the yellow ink applied to each of the

reflective flaps

421, 422 can be in the shape of a circle, a triangle, a parallelogram, a wave, or an array of dots, or an irregular shape.

As described above, each of the reflection flaps 421, 422 is connected to the reflection sheet main body 41 by the respective connection portion 43. In the embodiment of the present disclosure, the connection portion 43 is provided such that each of the reflection flaps 421, 422 can be folded with respect to the reflection sheet main body 41, for example, by about 90. . As shown in fig. 9, each of the reflection flaps 421, 422 may be folded by about 90 ° toward the light guide plate 6 with respect to the reflection sheet body 41.

Referring to fig. 8, one connection portion 43 may include a plurality of solid portions 431 and a plurality of cut-off portions 432, and the plurality of solid portions 431 and the plurality of cut-off portions 432 are alternately arranged in sequence. Each solid portion 431 connects one of the reflection flaps 421 or 422 with the reflection sheet main body 41, that is, the

reflection flap

421 or 422 is not disconnected from the reflection sheet main body 41 at the solid portion 431. Each of the disconnecting portions 432 disconnects one of the reflection flaps 421 or 422 from the reflection sheet main body 41. For example, each of the disconnected portions 432 may be a hollowed-out portion, which disconnects the

reflective flap

421 or 422 from the reflective sheet body 41 at each of the disconnected portions 432. By such an intermittent attachment structure, each of the reflection flaps 421, 422 can be folded with respect to the reflection sheet main body 41.

For example, the reflective sheet body 41 and each of the

reflective flaps

421, 422 may be made of the same material. The solid portion 431 of each connection portion 43 may be made of the same material as that of the reflection sheet main body 41. In an actual manufacturing process, the structure of the reflection sheet main body, the reflection flaps and the connection portions may be formed by one-time processing through a molding process, that is, the reflection sheet 4 may be manufactured through a molding process.

Referring to fig. 9, when the reflective sheet 4 is assembled into the backlight module 100, each of the reflective flap structures 42 of the reflective sheet 4 is located at a position corresponding to the position P1. As described above, at the position P1, a part of the inner wall 32 of the middle frame is cut away. Advantageously, the length (i.e., the dimension in the direction parallel to the side of the reflective sheet body) of each of the

reflective flaps

421, 422 can be equal to the length of the frame inner wall 32 cut away at the position P1. That is, the reflection flap structure 42 of the reflection sheet 4 does not overlap with the orthographic projection of the inner frame wall 32 on the bottom plate 21 of the backboard 1.

As shown in fig. 9, the reflection sheet body 41 of the reflection sheet 4 is sandwiched between the light guide plate 6 and the back panel 2, and each of the reflection flaps 421, 422 of the reflection sheet 4 may be folded toward the light guide plate 6 with respect to the reflection sheet body 41, for example, by about 90 °. An upper surface of each of the reflection flaps 421, 422 is coated with yellow ink 425, that is, a surface of each of the reflection flaps 421, 422 facing the light guide plate 6 is coated with yellow ink 425.

In the embodiment of the present disclosure, the height (i.e., the dimension in the light emitting direction) of each of the reflection flaps 421, 422 is greater than the thickness of the light guide plate 6. Thus, it is advantageous that all the blue light emitted from the side of the light guide plate 6 is absorbed or reflected by the

reflective flaps

421 and 422.

As shown in fig. 9, a portion of the blue light L1 emitted from the light guide plate 6 is incident on the reflection flaps 421 and 422, and since the surface of each of the reflection flaps 421 and 422 facing the light guide plate 6 is coated with yellow ink, the yellow ink may absorb a portion of the blue light L1 and reflect another portion of the blue light L1. A portion of the blue light reflected by the yellow ink becomes yellow, as shown by light L2 in fig. 9. The yellow light L2 is mixed with other blue light (shown as light L3 in fig. 9) emitted from the light guide plate 6 to form white light, and the white light can be merged into the white light emitted from the backlight module 100, so as to reduce or even eliminate the problem that the blue light at the position P1 is strong (i.e., the blue light leaks at the position P1).

In the actual manufacturing process, the shade of yellow of the yellow ink on the reflector flap can be adjusted according to the degree of blue light leakage at position P1. For example, when the degree of blue light leakage at position P1 is severe, the yellow color of the yellow ink on the reflective flap can be set deeper; the yellow color of the yellow ink on the reflector flap may be set lighter when the degree of blue light leakage at position P1 is less.

It should be noted that in other embodiments, the length (i.e., the dimension in the light emitting direction) of each of the

reflective flaps

421 and 422 can be greater than or less than the length of the inner wall 32 of the middle frame cut at the position P1. And optionally, the height (i.e., the dimension in the light emitting direction) of each of the

reflective flaps

421 and 422 may be less than or equal to the height of the side panel 22 of the back panel 2, so that the

reflective flaps

421 and 422 do not interfere with the middle frame 3 in the height direction.

Referring back to fig. 4, at the position P2, an elastic member 9 made of an elastic material such as rubber is disposed between the light guide plate 6 and the side plate of the back panel 2. In an embodiment of the present disclosure, the elastic element 9 may be a yellow elastic element. For example, the double-oblique line in fig. 4 indicates that the elastic member 9 is set yellow as a whole. Alternatively, a side portion of the elastic member 9 facing the light guide plate 6 may be provided in yellow. That is, at least a side portion of the elastic member 9 facing the light guide plate 6 is set to yellow.

As shown in fig. 4, a portion of the blue light emitted from the light guide plate 6 is incident on the elastic member 9, and the elastic member 9 may absorb a portion of the blue light and reflect another portion of the blue light. A portion of the blue light reflected by the flexible element 9 becomes yellow light, as shown by the light L4 in fig. 4. The yellow light L4 is mixed with other blue light emitted from the light guide plate 6 to form white light, and the white light can be merged into the white light emitted from the backlight module 100, so as to reduce or even eliminate the problem that the blue light at the position P2 is stronger (i.e. the blue light leaks at the position P2).

For example, the elastic member 9 may be made yellow by adding yellow pigment to the rubber. Of course, other known processes may be used to form the yellow elastic element 9, and the embodiment of the present disclosure is not particularly limited thereto.

In the actual manufacturing process, the shade of yellow of the flexible element 9 can be adjusted according to the degree of blue light leakage at the position P2. For example, when the degree of blue light leakage at the position P2 is severe, the yellow color of the elastic member 9 may be set deep; when the degree of blue light leakage at the position P2 is slight, the yellow color of the elastic member 9 may be set to be lighter.

In the above embodiments, in view of the problem of non-uniform brightness and/or color of the emergent light at the position P1 and the position P2, the backlight module according to the embodiments of the present disclosure redesigns the reflective sheet and the rubber block by using the principle that yellow and blue light are mixed to generate white light, so as to reduce or even eliminate the problem.

The inventors further research and find that, in a side-in type backlight module using a blue light backlight, there is also a problem of non-uniform brightness and/or color of emergent light at the position of the protruding lug of the light guide plate, and for this problem, the embodiments of the present disclosure also provide a light guide plate and a backlight module including the light guide plate. Hereinafter, a light guide plate and a backlight module including the same, which are further provided by embodiments of the present disclosure, will be described in detail with reference to the accompanying drawings.

As the display device is developed toward the narrow bezel and the bezel-less bezel, the size of the middle bezel pressing the light guide plate becomes smaller, that is, the size a becomes smaller as shown in fig. 3. In this case, when the light guide plate 6 shrinks due to low temperature, there is a large risk that the light guide plate 6 jumps off the middle frame 3 (i.e., the light guide plate 6 is not pressed by the middle frame 3). Generally, a lug structure is provided at an edge of the light guide plate 6 to prevent the light guide plate 6 from being escaped from the middle frame 3.

For example, fig. 15A to 15C respectively show 3 kinds of lug structures provided at the edge of the light guide plate 6 in the related art. Exemplarily, fig. 15A to 15C schematically show 1 tab structure 62 provided on the left side surface of the light guide plate 6, respectively. Also, fig. 15A to 15C schematically show light distributions of the light exit surface of the light guide plate at the lug structures, respectively. In fig. 15A to 15C, a light ray propagating from the lower right to the upper left is an incident light, and a light ray propagating from the lower left to the upper right is a reflected light.

In fig. 15A, the lug structure 62 has a right angle transition. As shown by the light rays in fig. 15A, at the upper right angle, the light rays are densely distributed, i.e., a blue region with stronger blue light is formed; at the straight portions of the lug structure 62, the light distribution is sparse, i.e., a dark region with weak blue light is formed; at the lower right angle, the light distribution is sparse, i.e., a dark region with weak blue light is formed.

In fig. 15B, the lug structure 62 has a beveled transition. As shown by the light in fig. 15B, at the upper oblique side, the light is densely distributed, i.e., a blue region with stronger blue light is formed; at the straight portions of the lug structure 62, the light distribution is sparse, i.e., a dark region with weak blue light is formed; at the lower oblique side, the light distribution is sparse, i.e., a dark region with weak blue light is formed.

In fig. 15C, the lug structure 62 has a radiused transition portion. As shown by the light rays in fig. 15C, at the upper arc, the light rays are densely distributed, i.e., a blue region with stronger blue light is formed; at the straight portions of the lug structure 62, the light distribution is sparse, i.e., a dark region with weak blue light is formed; at the lower arc, the light is sparsely distributed, i.e., a dark region with weak blue light is formed.

That is, in the 3 kinds of lug structures disposed on the edge of the light guide plate 6 in the related art, there are obvious bright and dark regions, the bright and dark transition is non-linear, and the human eye may find the problem of non-uniformity in both brightness and color.

FIG. 10 is a schematic plan view of a light guide plate of a backlight module according to an embodiment of the disclosure; FIG. 11 is a partial enlarged view of a light guide plate of a backlight module according to an embodiment of the present disclosure, showing a lug structure of the light guide plate; fig. 12 is a cross-sectional view of a backlight module according to an embodiment of the disclosure at the ledge structure.

Referring to fig. 10 to 11 in combination, in the backlight assembly 100 according to the embodiment of the present disclosure, the light guide plate 6 includes a light guide plate body 61 and a tab structure 62. The light guide plate body 61 is a planar sheet-like structure, for example, an orthogonal projection of the light guide plate body 61 in the light exit direction of the light guide plate 6 may have a rectangular shape. The light guide plate body 61 includes 4 side surfaces, i.e., side surfaces 611, 612, 613, 614.

Sides

611, 612, 613, 614 are located at the day side, left side, right side, and ground side, respectively.

Referring to fig. 10 to 12 in combination, in order to prevent the light guide plate 6 from escaping from the middle frame 3, a plurality of lug structures 62 may be provided on the light guide plate body 61, for example, in the embodiment shown in fig. 10, 4 lug structures 62 may be provided on the side surface 611 on the day side, and 2 lug structures 62 may be provided on each of the side surface 612 on the left side and the side surface 613 on the right side. However, in other embodiments, more or fewer lug structures 62 may be provided depending on the size and positioning requirements of the light guide plate. Note that the ground side of the light guide plate body 61 is a light incident side, and it is generally not necessary to provide a lug structure on the side surface 614.

As shown in fig. 12, by providing the lug structure 62 on the light guide plate 6, the size (shown as size b in fig. 12) of the light guide plate 6 pressed by the middle frame 3 is increased, that is, size b in fig. 12 is larger than size a in fig. 3, so that the light guide plate 6 can be prevented from jumping out of the middle frame 3 at the time of low-temperature shrinkage.

Further, the inner wall 32 of the middle frame 3 is partially cut away at a position corresponding to the position where the lug structure 62 is provided to increase the distance between the outer side surface of the lug structure 62 and the inner surface of the side plate 22 of the rear plate 2 to ensure a sufficient expansion space of the light guide plate 6 in a high temperature state. Therefore, the orthographic projection of the lug structure 62 of the light guide plate 6 on the bottom plate 21 of the back plate 2 does not overlap with the orthographic projection of the inner frame wall 32 of the middle frame 3 on the bottom plate 21 of the back plate 2.

That is, herein, the position of the reflection flap structure 42 of the reflection sheet 4 corresponds to the position P1, and the position of the elastic element 9 corresponds to the position P2. The reflection folding sheet structure 42 of the reflection sheet 4, the elastic element 9, the lug structure 62 of the light guide plate 6 and the orthographic projection of the middle frame inner wall 32 on the bottom plate 21 of the back plate 2 do not overlap with each other, so as to avoid interference of the structures, thereby facilitating the assembly of the backlight module.

Referring back to fig. 11, each of the lug structures 62 may include a convex surface 621 parallel to the side surface of the light guide plate body 61, and a first transition portion 622 and a second transition portion 623 connecting the respective side surfaces and the convex surface 621. For example, fig. 11 shows one lug structure 62 disposed on the side surface 612 on the left side of the light guide plate body 61, and as shown in fig. 11, the lug structure 62 may include a convex surface 621 parallel to the side surface 612 of the light guide plate body 61, a first transition portion 622 and a second transition portion 623 connecting the side surface 612 and the convex surface 621. The convex surface 621 is located at the outermost side of the light guide plate 6 and is parallel to the side surface 612.

In an embodiment of the present disclosure, the first transition portion 622 includes a first circular arc portion 6221, an inclined portion 6222, and a second circular arc portion 6223. The first arc portion 6221 connects the side surface 612 and the inclined portion 6222, the inclined portion 6222 connects the first arc portion 6221 and the second arc portion 6223, and the second arc portion 6223 connects the inclined portion 6222 and the convex surface 621.

Specifically, one end of the first arc portion 6221 is tangent to the side surface 612, and the other end is tangent to the inclined portion 6222. The second arc portion 6223 has one end tangent to the convex surface 621 and the other end tangent to the inclined portion 6222. The inclined portion 6222 has one end tangent to the first arc portion 6221 and the other end tangent to the second arc portion 6223. The inclined portion 6222 has a predetermined inclination angle with respect to the side surface 612 or the convex surface 621.

For example, the radius of the first arc portion 6221 is R1, the radius of the second arc portion 6223 is R2, and the radius R1 of the first arc portion 6221 is greater than the radius R2 of the second arc portion 6223.

With continued reference to fig. 11, second transition 623 is mirror symmetric to first transition 622 with respect to convex surface 621. Similarly, the second transition portion 623 includes a first circular arc portion 6231, an inclined portion 6232, and a second circular arc portion 6233. The first arc portion 6231 connects the side surface 612 and the inclined portion 6232, the inclined portion 6232 connects the first arc portion 6231 and the second arc portion 6233, and the second arc portion 6233 connects the inclined portion 6232 and the convex surface 621.

Specifically, one end of the first arc portion 6231 is tangent to the side surface 612, and the other end is tangent to the inclined portion 6232. The second arc portion 6233 has one end tangent to the convex surface 621 and the other end tangent to the inclined portion 6232. The inclined portion 6232 has one end tangent to the first arc portion 6231 and the other end tangent to the second arc portion 6233.

For example, the radius of the first arc portion 6231 is R1, the radius of the second arc portion 6233 is R2, and the radius R1 of the first arc portion 6231 is larger than the radius R2 of the second arc portion 6233.

For example, the radius R1 of the

first arc portion

6221, 6231 may be about 90mm, the radius R2 of the

second arc portion

6223, 6233 may be about 40mm, and the angle of inclination of the

inclined portion

6222, 6232 with respect to the side surface 612 or convex surface 621 is about 5 °. Through the design, the transition at the lug structure is smooth, so that the light distribution at the lug structure is ensured to be uniform, and the problem of non-uniform brightness and color at the lug structure can be reduced or even eliminated.

Fig. 13 is a schematic view of light distribution of a light guide plate of a backlight module at a lug structure according to an embodiment of the present disclosure. In fig. 13, a light ray propagating from the lower right to the upper left is an incident light, and a light ray propagating from the lower left to the upper right is a reflected light.

With combined reference to fig. 11-13, in the light guide plate according to the embodiment of the disclosure, the transition portion between the convex surface of the lug structure and the side surface of the light guide plate is improved, and the transition at the lug structure is smooth, so that the light distribution at the lug structure is uniform, and the problem of non-uniformity of brightness and color at the lug structure can be reduced or even eliminated. By comparing the light distributions of fig. 13 and fig. 15A to 15C, it can be seen that: although the light distribution shown in fig. 13 also includes a plurality of light sparse regions (e.g., light sparse region a, light sparse region D shown in fig. 13) and a plurality of light dense regions (e.g., light dense region B, light dense region C shown in fig. 13), the difference in light distribution density between the light sparse regions and the light dense regions is much smaller than that in fig. 15A-15C, and the transition between the light sparse regions a, light dense region B, light dense region C, and light sparse regions D is very gradual.

Of course, the embodiments of the present disclosure are not limited to the specific values, for example, the radius R1 of the first arc portion may be selected within a range of 80-100 mm, such as 85mm, 95mm, etc.; the radius R2 of the second arc part can be selected within the range of 30-50 mm, such as 38mm, 39mm, 41mm, 42mm, etc. The inclination angle of the inclined portion with respect to the side 612 or convex 621 depends on the radius R1 of the first arc portion and the radius R2 of the second arc portion, and for example, the inclination angle of the inclined portion with respect to the side 612 or convex 621 may be selected in the range of 4 ° to 6 °, for example, 4.5 °.

As another example, the height of the lug structure (dimension b shown in FIG. 11) may be about 1.2mm, i.e., the vertical distance between convex surface 621 and side 612 (dimension b shown in FIG. 11) is about 1.2 mm. Thus, the size of the middle bezel pressing against the light guide plate (i.e., the size a shown in fig. 12) is increased by about 1.2 mm.

Fig. 14 is a partial schematic view of a light guide plate according to an embodiment of the present disclosure, schematically illustrating a plurality of protrusions disposed on the light guide plate and light distribution on a light exit surface. As shown in fig. 14, the light guide plate 6 may further include a plurality of protrusions 615 (also referred to as dots) disposed on the light guide plate main body 61, for example, the plurality of protrusions 615 are disposed on a surface of the light guide plate main body 61 opposite to the light exit surface (e.g., the bottom surface 65 of the light guide plate 6 shown in fig. 12). The protrusions 615 serve to scatter light incident thereon, so that light exiting from the light-exiting surface of the light guide plate 6 is more uniform.

Further, in order to further make the light emitted from the light exit surface of the light guide plate 6 more uniform, the distribution density of the protrusions 615 may be adjusted. For example, the distribution density of the protrusions 615 in the optically dense region B and the optically dense region C is decreased, and the distribution density of the protrusions 615 in the optically sparse region a and the optically sparse region D is increased. That is, a plurality of optically sparse regions and a plurality of optically dense regions are formed on the light exit surface of the light guide plate 6, and in the embodiment of the present disclosure, the distribution density of the protrusions is adjusted such that the distribution density of the plurality of protrusions 615 in the region on the bottom surface 65 corresponding to the optically sparse regions is greater than the distribution density of the plurality of protrusions 615 in the region on the bottom surface 65 corresponding to the optically dense regions.

Thus, the difference in light distribution among the optically thinner region a, the optically denser region B, the optically denser region C, and the optically thinner region D can be compensated, and the uniformity of color and brightness of light emitted from the light-emitting surface of the light guide plate 6 can be further improved.

It should be noted that the display device 1000 provided in the embodiments of the present disclosure may include a display panel and the backlight module 100 provided in any of the embodiments. For example, the display device may be a display device such as a television, although the embodiments of the present disclosure are not limited thereto, and for example, the display device may be any product or component having a display function, such as a smart phone, a tablet computer, a display, a navigator, and the like.

Although a few embodiments which explain the general principles of the present disclosure have been shown and described, it will be appreciated by those skilled in the art that changes may be made in these embodiments without departing from the principles and spirit of the general principles of the disclosure, the scope of which is defined in the claims and their equivalents.

Claims

1. A reflective sheet comprising:

a reflector sheet main body;

a reflective flap structure comprising at least one reflective flap; and

a connecting part which is connected with the connecting part,

yellow ink is disposed on at least one surface of the reflective flap.

2. A reflective sheet according to claim 1, wherein the reflector flap structures comprise first and second reflector flap structures located at 2 corners of the reflective sheet body, respectively.

3. The reflective sheet according to claim 2, wherein the reflective sheet body comprises a first side surface, a second side surface and a third side surface, the second side surface and the third side surface being disposed opposite to each other, the first side surface connecting the second side surface and the third side surface,

4. The reflection sheet according to any one of claims 1 to 3, wherein the connection portion comprises a plurality of solid portions and a plurality of broken portions, the plurality of solid portions and the plurality of broken portions being alternately arranged in this order.

5. A backlight module includes:

the reflective sheet of any one of claims 1-4;

a light guide plate;

an optical film having a plurality of optical layers,

6. The backlight module according to claim 5, further comprising an elastic member disposed between the light guide plate and the side plate,

7. A backlight module according to claim 5 or 6, wherein the reflective flap is folded with respect to the reflector sheet body towards the light guide plate, and the yellow ink is coated on a surface of the reflective flap facing the light guide plate.

8. The backlight module according to claim 6, wherein the light guide plate comprises:

a lug structure protruding from a side surface of the light guide plate body,

9. The backlight module according to claim 8, wherein one end of the first arc portion is tangent to the side surface of the light guide plate body, and the other end is tangent to the inclined portion;

10. The backlight module according to claim 5, 6 or 9, wherein the size of the reflection flap in the light exit direction of the backlight module is larger than the size of the light guide plate in the light exit direction of the backlight module.

11. The backlight module according to claim 9, wherein the radius of the first circular arc portion is larger than the radius of the second circular arc portion.

12. The backlight module according to claim 11, wherein the radius of the first arc portion is in the range of 80-100 mm, and/or the radius of the second arc portion is in the range of 30-50 mm.

13. A backlight module according to claim 11 or 12, wherein the inclined portion has an inclination angle with respect to the convex surface in the range of 4 ° to 6 °.

14. The backlight module according to claim 9, 11 or 12, wherein the light guide plate further comprises a plurality of protrusions disposed on a bottom surface of the light guide plate body, the bottom surface being opposite to the light emitting surface of the light guide plate, the plurality of protrusions for scattering light incident thereon,

15. The backlight module according to claim 8, wherein orthographic projections of the reflection flap structures of the reflection sheet, the elastic elements and the lug structures of the light guide plate on the bottom plate of the back plate do not overlap each other.

16. The backlight module according to claim 8, further comprising a middle frame pressing the reflection sheet, the light guide plate, and the optical film toward a bottom plate of the back plate,

17. A backlight module according to any one of claims 5, 6, 8, 9, 11, 12, 15 and 16, further comprising a backlight disposed at one side of the light guide plate, the backlight comprising a plurality of light emitting diodes, the light emitting diodes being blue emitting light emitting diodes.

18. A backlight module according to claim 17, wherein the optical film comprises a quantum dot film comprising a plurality of yellow quantum dots.