CN113448125A

CN113448125A - Backlight module and display device

Info

Publication number: CN113448125A
Application number: CN202110805085.0A
Authority: CN
Inventors: 董钊; 杜芸; 尹清平; 鲍均; 张斗庆; 赵雪梅; 康海; 李虎
Original assignee: BOE Technology Group Co Ltd; Hefei BOE Optoelectronics Technology Co Ltd
Current assignee: BOE Technology Group Co Ltd; Hefei BOE Optoelectronics Technology Co Ltd
Priority date: 2021-07-16
Filing date: 2021-07-16
Publication date: 2021-09-28

Abstract

The invention relates to a backlight module, which comprises a backlight source and an optical structure arranged on the light-emitting side of the backlight source, wherein the optical structure comprises a prism layer, the prism layer comprises a plurality of prisms extending along a first direction, each prism comprises a bottom surface and a prism peak arranged on one side opposite to the bottom surface, each prism peak comprises a first connecting surface and a second connecting surface, the first connecting surfaces and the second connecting surfaces are positioned on two sides of the vertex of each prism peak, a connecting line between one end, far away from the vertex of each prism peak, of each first connecting surface and the vertex of each prism peak is a first connecting line, a connecting line between one end, far away from the vertex of each prism peak, of each second connecting surface and the vertex of each prism peak is a second connecting line, and an included angle between each first connecting line and each second connecting line is an obtuse angle.

Description

Backlight module and display device

Technical Field

The invention relates to the technical field of liquid crystal product manufacturing, in particular to a backlight module and a display device.

Background

With the wide application of LCD display module in fields such as education, intelligent house, when pursuing vision to be shared, the demand of "eyeshield" is increasingly strong, has the research to show: the brightness variation may cause fatigue of human eyes. When the brightness is low, the rod cells are easy to be excessively regulated, and ciliary muscles are continuously in a tense state; when the brightness is too high, the pupil sphincter is easy to be in a contraction state, the pupil is contracted, and visual fatigue is caused; the conventional LCD display screen changes along with the visual angle, the brightness is attenuated too fast (the brightness is attenuated by 50 percent when the central angle deviates by 20 degrees), and the eye adjusting visual fatigue is easily caused; maintain a fixed posture (unchanged visual angle), and are prone to cause cervical spondylosis and myopia.

The full-width-at-half-maximum (FWHM) viewing angle Spec refers to a corresponding azimuth angle when the brightness is attenuated by half, the larger the viewing angle is, the slower the brightness attenuation is, and the more beneficial the vision protection is, and at present, the conventional 4 files (a lower diffusion sheet, a lower prism sheet, an upper prism sheet and an upper diffusion sheet which are sequentially arranged along the light-emitting direction of a backlight source) framework BLU MDL (a backlight module arranged in a stacked structure) can only realize the FWHM viewing angle of each azimuth 25 degrees.

Disclosure of Invention

In order to solve the above technical problems, the present invention provides a backlight module and a display device, which solve the problem that the brightness of the backlight module is too fast to be attenuated as the viewing angle is increased.

In order to achieve the purpose, the embodiment of the invention adopts the technical scheme that: the utility model provides a backlight module, includes the backlight with set up in the optical structure of the light-emitting side of backlight, optical structure includes the prism layer, the prism layer includes a plurality of prisms that extend along first direction, the prism includes the bottom surface to and with the arris peak that the relative one side of bottom surface set up, the arris peak is including being located the first connection face and the second of the both sides on the summit of arris peak are connected, the prism is along the perpendicular to on the cross-section of bottom surface direction, first connection face is kept away from the one end on the summit of arris peak with line between the summit of arris is first line, the second is connected the face and is kept away from the one end on the summit of arris peak with line between the summit of arris peak is the second line, first line with contained angle between the second line is the obtuse angle.

Optionally, the optical structure further includes a first diffusion layer located on the backlight side of the prism layer, and/or a second diffusion layer located on the light exit side of the prism layer, where the haze of the first diffusion layer is 90% to 95%, and the haze of the second diffusion layer is 90% to 110% of that of the first diffusion layer.

Optionally, the optical structure further comprises a brightness enhancement film located on the light exit side of the prism layer.

Optionally, the optical structure includes a first diffusion layer, a prism layer, a second diffusion layer and a brightness enhancement film, which are sequentially stacked along a direction away from the backlight source.

Optionally, in a plane parallel to the first direction and parallel to the light exit direction of the backlight source, the brightness of the first viewing angle is half of the central brightness of the backlight module, and the first viewing angle is greater than or equal to |45 ° |, and/or

And in a plane which is vertical to the first direction and parallel to the light emergent direction of the backlight source, the brightness of a second visual angle is half of the central brightness of the backlight module, and the second visual angle is greater than or equal to |40 |.

Optionally, the first connecting surface is a curved surface, and the radius of the curved surface is 5-9 um.

Optionally, the first connection surface is a plane, and an included angle between the first connection surface and the second connection surface is 110 ° to 130 °.

Optionally, the prism includes a first inclined plane and a second inclined plane located between the bottom surface and the ridge, the first inclined plane and the first connection surface are located on the same side of the vertex of the ridge, an included angle between the first inclined plane and the first connection surface is an obtuse angle, the second inclined plane and the second connection surface are located on the same side of the vertex of the ridge, and an included angle between the second inclined plane and the second connection surface is an obtuse angle;

the angle of an included angle formed by extending and intersecting the first inclined surface and the second inclined surface is 80-100 degrees.

Optionally, the interval between two adjacent ridge peaks is 20-48 μm.

Optionally, the backlight source includes a light source, and the light source is a blue LED with a peak wavelength of not less than 460 um.

Optionally, along a second direction perpendicular to the first direction, the prism layer includes a plurality of prism units arranged periodically, and heights of a plurality of prisms in each prism unit in a light exit direction of the backlight are different.

Alternatively, in a direction perpendicular to the first direction, a vertex of the ridge of each of the prisms is shifted to a side close to the first connection surface, or a vertex of the ridge of each of the prisms is shifted to a side close to the second connection surface.

Optionally, in a direction perpendicular to the first direction, the prism layer has a first center line, a vertex of each of the prism peaks is shifted to a side close to the first center line, and the farther the distance from the first center line, the smaller the shift amount of the vertex of the prism peak is.

Optionally, in a direction perpendicular to the first direction, heights of the plurality of prisms in a direction parallel to the light exit direction of the backlight gradually decrease from the middle to both sides.

The embodiment of the invention also provides a display device which comprises the backlight module and a display panel, wherein the display panel is arranged on the light-emitting side of the backlight module.

Optionally, the display device is further located on a polarizer on a backlight side of the display panel;

along the direction far away from the backlight source, the optical structure comprises a first diffusion layer, a prism layer and a second diffusion layer which are sequentially stacked;

and a brightness enhancement film is integrated on the polarizer.

Optionally, along keeping away from display panel's direction, the polaroid includes polarisation rete and the stratum basale that the stromatolite set up in proper order, the brightness enhancement film set up in the polarisation rete with between the stratum basale, perhaps the brightness enhancement film set up in the polarisation rete is kept away from one side of stratum basale.

The invention has the beneficial effects that: the optical structure in the embodiment of the invention comprises a prism layer, wherein the prism layer comprises a plurality of prisms extending along a first direction, each prism comprises a bottom surface and a prism peak arranged on one side opposite to the bottom surface, each prism peak comprises a first connecting surface and a second connecting surface which are positioned on two sides of the vertex of the prism peak, a connecting line between one end of the first connecting surface far away from the vertex of the prism peak and the vertex of the prism peak is a first connecting line, a connecting line between one end of the second connecting surface far away from the vertex of the prism peak and the vertex of the prism peak is a second connecting line, and an included angle between the first connecting line and the second connecting line is an obtuse angle, so that the visual angle is increased when the brightness is generally attenuated, and the brightness of a central point is kept at a higher level.

Drawings

FIG. 1 is a schematic view of a light-emitting direction of a backlight module according to an embodiment of the invention;

FIG. 2 is a schematic view of an emergent light angle of a backlight module according to an embodiment of the invention

FIG. 3 is a schematic diagram of a first prism structure according to an embodiment of the present invention;

FIG. 4 is a schematic diagram of a second prism structure in an embodiment of the present invention;

FIG. 5 is a schematic diagram of a prism layer in accordance with the present invention

FIG. 6 is a second schematic diagram illustrating a structure of a prism layer according to an embodiment of the present invention;

FIG. 7 is a schematic diagram showing a partial structure of a prism layer in an embodiment of the present invention;

FIG. 8 is a schematic diagram showing the distribution of a light field with a prism having a zero peak radius in an embodiment of the present invention;

FIG. 9 is a schematic diagram showing the distribution of a light field with a prism having a peak radius of 1 in an embodiment of the present invention;

FIG. 10 is a schematic diagram showing the distribution of a light field with a prism having a peak radius of 2 in an embodiment of the present invention;

FIG. 11 is a schematic diagram showing the optical effect of a prism according to an embodiment of the present invention;

FIG. 12 is a first chart showing the trend of azimuth view in an embodiment of the present invention;

FIG. 13 is a schematic view showing the distribution of an optical field using a diffusion layer in an embodiment of the present invention;

FIG. 14 is a first schematic diagram of a light field distribution using a single prism layer in an embodiment of the present invention;

FIG. 15 is a second schematic diagram of the optical field distribution using a single prism layer in an embodiment of the present invention;

FIG. 16 shows a third schematic structural view of a prismatic layer in an embodiment of the present invention;

FIG. 17 shows a fourth schematic structural view of a prism layer in an embodiment of the invention;

FIG. 18 shows a fifth schematic structural view of a prismatic layer in an embodiment of the present invention;

FIG. 19 is a second trend chart of azimuth angles in an embodiment of the present invention;

fig. 20 is a schematic structural diagram of a display device according to an embodiment of the present invention.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the drawings of the embodiments of the present invention. It is to be understood that the embodiments described are only a few embodiments of the present invention, and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the described embodiments of the invention, are within the scope of the invention.

In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicate orientations or positional relationships based on those shown in the drawings, and are only for convenience of description and simplicity of description, but do not indicate or imply that the device or element referred to must have a specific orientation, a specific orientation configuration and operation, and thus, should not be construed as limiting the present invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance.

One solution involved in the related art is to adopt a scheme of multiple diffusion, such as 3 diffusions instead of the conventional 4films architecture, to achieve the full-scale half-height wide viewing angle requirement, and the advantages of the scheme are as follows: the full-width half-maximum viewing angle of each direction is more than or equal to 50 degrees, but the brightness loss exceeds 30 percent, and the too low brightness or the too high power consumption under the same brightness can be caused.

Referring to fig. 1 to 7, in order to solve the above problem, the present embodiment provides a backlight module including a backlight source and an optical structure disposed on a light emitting side of the backlight source, where the optical structure includes a prism layer, the prism layer includes a plurality of prisms 1 extending along a first direction (refer to an X direction in fig. 5), the prisms 1 include a bottom surface 11, and a prism peak disposed on a side opposite to the bottom surface 11, the prism peak includes a first connection surface 14 and a second connection surface 15 located on two sides of a vertex of the prism peak, the prism is on a cross section along a direction perpendicular to a bottom surface of the prism, a connection line between one end of the first connection surface 14 far from the vertex of the prism peak and the vertex of the prism peak is a first connection line 100, a connection line between one end of the second connection surface 15 far from the vertex of the prism peak and the vertex of the prism peak is a second connection line 200, an included angle a between the first line 100 and the second line 200 is an obtuse angle.

The vertex of the ridge, the end of the first connection surface 14 away from the vertex of the ridge, and the end of the second connection surface 15 away from the vertex of the ridge are coplanar, that is, all lie on a cross section perpendicular to the prism base surface direction.

In this embodiment, still include the third connection face between the first connection face and the bottom surface, the third connection face can extend the setting along a direction, and the connection face that also can a plurality of directions extend meets and forms, and is same, the second connection face with still include the fourth connection face between the bottom surface, the fourth connection face can extend the setting along a direction, and also can the connection face that a plurality of directions extend meets and forms.

Fig. 1 is a schematic view of a backlight module, in which a first plane having an azimuth angle of 0 degree and 180 degrees is parallel to an extending direction of the prism, i.e., the first direction, and is perpendicular to a light emitting direction of the backlight module, an included angle between a second plane having an azimuth angle of 45 degrees and 225 degrees and the first plane is 45 degrees, an included angle between a third plane having an azimuth angle of 90 degrees and 270 degrees and the first plane is 90 degrees, and an included angle between a fourth plane having an azimuth angle of 135 degrees and 315 degrees and the first plane is 135 degrees. FIG. 2 is a view angle definition diagram, and FIG. 2 shows a corresponding angle θ (θ) in the first plane when the brightness is half of the brightness of the center point positive view angle₁And theta₂)；

In the embodiment, the prism structure is improved, that is, a connecting line between one end of the first connecting surface far from the vertex of the prism and the vertex of the prism is a first connecting line, a connecting line between one end of the second connecting surface far from the vertex of the prism and the vertex of the prism is a second connecting line, and an included angle between the first connecting line and the second connecting line is an obtuse angle, referring to fig. 3 and 4, in the embodiment, the prism includes a first connecting surface 14 and a second connecting surface 15, and in fig. 3 and 4, a dotted line on a side of the first connecting surface 14 and a side of the second connecting surface 15 far from the bottom surface 11 is represented as the prism of a conventional prism, in contrast, the structure of the prism is changed, and the distance between two adjacent prisms is not changed, for example, the distance between adjacent prisms in the prior art, fig. 5 shows a schematic structural diagram of a prism layer including a plurality of prisms 1, a position indicated by a dotted circle in fig. 5 is a prism peak, fig. 5 shows a distance between two adjacent prisms (which may be a distance between two adjacent prism peaks, or a distance between center points of two adjacent bottom surfaces), and a prism Angle of the prism peak, and by using the prisms in this embodiment, Useful Light (effective Light in front view direction) is reduced, and High Angle Light (Light in large view Angle) is increased, so as to realize a view Angle Target, that is, the brightness attenuation is slow under the large view Angle, and the center point brightness can also maintain a High level.

It should be noted that, in this embodiment, optionally, the first connection surface 14 and the second connection surface 15 have the same shape, for example, the first connection surface 14 and the second connection surface 15 are both curved surfaces, or the first connection surface 14 and the second connection surface 15 are both flat surfaces, and optionally, the first connection surface 14 and the second connection surface 15 are symmetrically disposed, so that not only can uniform light divergence be realized, but also the process preparation is simpler.

In this embodiment, the first connecting surface 14 is a curved surface having a radius of 5-9 um.

In this embodiment, the first connection surface 14 is a plane, and the included angle between the first connection surface 14 and the second connection surface 15 is 110 ° to 130 °.

The optical structure including the prism of the present embodiment will be specifically described below by taking the first connecting surface 14 and the second connecting surface 15 as curved surfaces.

Fig. 7 is a schematic partial structure diagram of a prism layer, in fig. 7, the first connection surface 14 and the second connection surface 15 are both curved surfaces, at this time, a peak radius of an edge is R, fig. 8 shows a schematic light field distribution when R is 0, a central point has high luminance, which reaches 613nit, but a half-height wide viewing angle is relatively small, which is only about 20 degrees, fig. 9 shows a schematic light field distribution when R is 1um, a peak radius is increased, a central point has low luminance, which is 583nit, a half-height wide viewing angle is increased to about 30, and fig. 10 shows a schematic light field distribution when R is 2 um. The peak radius is further increased, the brightness of the center point is 557nit, the full width at half maximum viewing angle is increased to about 35 degrees, and fig. 11 is a light effect schematic diagram of the prism. Comparing fig. 8, 9 and 10, if the peak radius R of the prism is increased, the brightness of the center point is decreased, and the azimuth viewing angle is increased; the reason is that the prism edge is changed from a right Angle (R ═ 0) to an R Angle (R ≠ 0), and as R becomes larger, usefull Light is gradually reduced, but High Angle Light is simultaneously raised, so it can be raised by sacrificing brightness in exchange for the viewing Angle, but in the present embodiment, the peak radius of the edge is changed, and the width of the bottom surface 11 in the direction perpendicular to the first direction is changed (generally 20-48mm), so that while the viewing Angle is enlarged, the brightness attenuated as the viewing Angle becomes larger is reduced, i.e. the center point position is ensured to have higher brightness.

In this embodiment, the prism includes a first inclined surface 12 and a second inclined surface 13 located between the bottom surface and the ridge, the first inclined surface 12 and the first connecting surface 14 are located on the same side of the peak of the ridge, and the second inclined surface 13 and the second connecting surface 15 are located on the same side of the peak of the ridge;

the angle formed by extending and intersecting the first inclined surface 12 and the second inclined surface 13 is 80-100 degrees.

Referring to fig. 3 and 4, in this embodiment, an included angle b formed by extending and intersecting the first inclined surface 12 and the second inclined surface 13 is smaller than an included angle a between the first connection line 100 and the second connection line 200 (when the first connection surface 14 and the second connection surface 15 are planar, the first connection surface 14 and the first connection line 100 are overlapped, and the second connection surface 14 and the second connection line 200 are overlapped), which is effective to realize that brightness is ensured while viewing angle is increased.

In this embodiment, one side surface of the prism is formed by connecting the first inclined surface 12 and the first connecting surface 14, and the other side surface of the prism is formed by connecting the second inclined surface 13 and the second connecting surface 15, and compared to a structure in which the side surface of the prism is formed by one surface along one extending direction, as shown by a dotted line in fig. 3 and 4, an angle a is larger than an angle b, which is advantageous for increasing a viewing angle.

In this embodiment, one side surface of the prism is formed by connecting the first inclined surface 12 and the first connecting surface 14, and the other side surface of the prism is formed by connecting the second inclined surface 13 and the second connecting surface 15, that is, compared with a conventional prism, in this embodiment, only the edge of the prism is modified, the bottom surface of the prism is not changed, and the inclination angles of the side surfaces of the prism except for the edge are not changed. If the width of the bottom surface of the prism in the direction perpendicular to the extending direction of the bottom surface of the prism is not changed, the ridge of the prism is not changed, and only the included angle between the side surface of the prism and the bottom surface is reduced, namely the inclination angle of the side surface of the prism is changed, so that the included angle between the two side surfaces of the prism forms an obtuse angle, the viewing angle can be increased, but the light output quantity of collimated light is reduced. In this embodiment, only the structure at the ridge is changed, so that the included angle between the first connecting line and the second connecting line is an obtuse angle, thereby increasing the viewing angle, relatively speaking, a small amount of light output in the collimation direction is lost, that is, the viewing angle is increased, and the brightness of the central point is ensured.

Haze is the appearance of haze caused by light scattering inside or on the surface of a transparent or translucent specimen. Haze is defined as the percentage of light transmitted as it passes through the sample that deviates from the direction of the incident line due to scattering by the front.

In this embodiment, as an example, the optical structure 103 further includes a first diffusion layer 2 located on the backlight side of the prism layer, and/or a second diffusion layer 3 located on the light-emitting side of the prism layer, where the haze of the first diffusion layer 2 is 90% to 95%, the haze of the second diffusion layer 3 is 90% to 110% of the haze of the first diffusion layer 2, optionally, the haze of the first diffusion layer 2 is 90% to 95%, the haze of the second diffusion layer 3 is 90% to 95%, and the optional haze of the first diffusion layer 2 is equal to the haze of the second diffusion layer 3, for example, both the haze values are 90%, or 91%, 95%, etc. are not limited, and of course, the haze of the first diffusion layer 2 and the haze of the second diffusion layer 3 may not be the same, but the haze range is still 90% to 95%, for example, the haze value of the first diffusion layer 2 is 90%, the haze of the second diffusion layer 3 was 95%.

For example, fig. 12 shows the viewing angle trends of light emitted by the backlight module of the first diffusion layer 2 at the backlight side of the prism layer and the second diffusion layer 3 at the light-emitting side of the prism layer in each direction, and the line with the reference number of 20, and the viewing angle trends of light emitted by the backlight module of the first diffusion layer 2 at the backlight side of the prism layer in each direction, and the line with the reference number of 10, it can be seen that the viewing angle in the vertical direction of the prism peak (the direction perpendicular to the first direction) can be increased by about 6 °, and reference to the viewing angle (the position indicated by the arrow) corresponding to the azimuth angle of 90 ° or 270 ° in fig. 12, and the diffusion layer is added to enable the light to be more uniform.

In this embodiment, the first diffusion layer 2 and the second diffusion layer 3 both have a relatively high haze, and the difference between the haze of the first diffusion layer and the haze of the second diffusion layer is relatively small, so that the viewing angle can be effectively increased, that is, not only can the light emission be ensured to be more uniform, but also the viewing angle of a plane (90-270 degrees) perpendicular to the extending direction of the prism can be increased.

In this embodiment, the optical structure 103 further includes a brightness enhancement film 4 on the light-emitting side of the prism layer.

Fig. 13 shows a schematic view of light field distribution using a diffuser, the central point brightness is 500, the half-height and wide viewing angle is only about 20 degrees, fig. 8 shows a schematic view of light field using a brightness enhancement film 4, the central point brightness reaches 700, and the half-height and wide viewing angle is increased, referring to fig. 13 and 8, the brightness enhancement film 4 is used to replace the diffuser, the front viewing angle brightness of the backlight module can be increased by about 36%, and the half-height and wide viewing angle of each azimuth can be increased by about 4%.

In this embodiment, the optical structure 103 includes at least one prism layer.

Fig. 8 is a schematic view showing a light field distribution using two prism layers, each having a peak radius R of 0, and fig. 14 and 15 are schematic views each using one prism layer, wherein prisms in the prism layer in fig. 14 are arranged to extend in a direction perpendicular to the first direction, the peak radius R of the prisms is 0, and prisms in the prism layer in fig. 15 are arranged to extend in the first direction, and the peak radius R of the prisms is 0.

Comparing fig. 8 and 14, or comparing fig. 8 and 15, it can be obtained that, comparing fig. 14 and 15 with fig. 8, the central point brightness is reduced, but the viewing angle of the backlight module in fig. 14 and 15 in the direction parallel to the extending direction of the prisms is raised by about 20 ° (mainly, the brightness of light at large viewing angle is raised & the central brightness of the backlight module is reduced); the viewing angle in the direction perpendicular to the extending direction of the prisms is raised by about 5 ° (mainly the central brightness of the backlight module is lowered). It can be seen that the arrangement of a single prism layer is more suitable for the wide viewing angle solution, and therefore, in a specific embodiment of this embodiment, the optical structure 103 includes one prism layer, but is not limited thereto, and may also include two or more layers, which may be specifically set according to the actual application.

In the embodiment, preferably, the optical structure 103 includes a first diffusion layer 2, a prism layer, a second diffusion layer 3, and a brightness enhancement film 4 stacked in this order in a direction away from the backlight.

In this embodiment, when the optical structure 103 includes the first diffusion layer 2, the prism layer, the second diffusion layer 3, and the brightness enhancement film 4 stacked in this order along the direction away from the backlight, the following objectives can be achieved: in a plane parallel to the first direction and parallel to the light emergent direction of the backlight source, the brightness of a first visual angle is half of the central brightness of the backlight module, and the first visual angle is greater than or equal to |45 ° |, and/or

In addition, the |45 ° | and |40 ° | are defined with the viewing angle at the center point as 0. Referring to fig. 2, in the view angle measurement, if the center point is 0 degree, the position of the azimuth angle of 0 degree in the measurement plane is set to +90 degrees, and the position of the azimuth angle of 180 degrees is set to-90 degrees, θ is measured₁Is positive, theta₂I.e. negative.

Referring to the above table and fig. 19, fig. 19 shows that the optical structure 103 adopts 1# -6#6 structures in the table, and the azimuth viewing angle trend of the emergent light of the backlight module is sequentially shown from bottom to top, different optical structures 103 are tested, in some embodiments, among the 6 structures, the brightness enhancement film 4 adopts DBEF5, the incremental effect is greater than 30%, the diffusion layers adopt B75VU-S, the haze is 93.79%, the light transmittance is 85.83%, the prisms adopt 4.20TJ, the peak radii R are 0 μm, 2 μm, 5 μm, 7 μm and 9 μm respectively, and no prism layer is tested, while the optical structure 103 is composed of three diffusion layers stacked on top of each other and the brightness enhancement film 4 located at the emergent layer of the three diffusion layers, the central positive viewing angle brightness contrast of the structures in 6 in the above table is known, and the prisms adopt R-type prisms (i.e. the included angle between the first connecting line and the second connecting line is an obtuse angle), as the peak radius increases, the central normal viewing angle luminance decreases, whereas the luminance decay is too large compared to the 6 th configuration, in which the prism central normal viewing angle luminance is not set to 366 nit.

Referring to the table and fig. 19, when the peak radius R of the prism is 5 μm, the central brightness of the backlight module is decreased by 5.37% and the brightness loss is within 10%, compared to 0; when the peak radius R of the prism is 7 μm, the central brightness of the backlight module is reduced by 7.68%, and the brightness loss is within 10%. In the related art, the prism layer is removed, and the optical structure 103 only adopts 3 diffusion layers, so that the full-width-at-half-maximum viewing angle of the structure is more than or equal to 50 degrees in all directions, which is greatly beyond the expectation of customers, but the loss of the brightness is more than 30 percent, and the over-low brightness or the over-high power consumption under the same brightness is caused; in contrast, in the optical structure 103 in this embodiment, when the optical structure 103 is arranged along a direction away from the backlight, and the optical structure 103 includes the first diffusion layer 2, the prism layer, the second diffusion layer 3, and the brightness enhancement film 4 which are sequentially stacked, each azimuth viewing angle satisfies the customer requirements, and is greater than or equal to 40 degrees, and the central brightness loss is within 10%, so that the power consumption is reduced.

In this embodiment, the backlight source includes a light source, and the light source is a blue LED with a peak wavelength greater than or equal to 460 um.

The low-blue-light LED reduces the damage of blue light, further reduces the damage to the eyesight of human eyes, reduces the surface glare through the CG (cover plate) subjected to AG treatment (atomization treatment), and realizes the paper-like technology.

In the embodiment, the spacing between two adjacent ridge peaks is 20-48 μm.

The pitch between two adjacent ridges is 20-48 μm, or it can be said that, in the direction perpendicular to the extending direction of the prisms, the distance between the centers of the bottom surfaces of two adjacent prisms is 20-48 μm, the setting of the pitch determines the density of prism distribution, the prisms have the function of converging light while playing the role of expanding the visual angle, the higher the prism distribution density is, the higher the brightness of light is, and the lower the prism distribution density is, the loss of brightness of light is increased, therefore, in order to ensure the brightness of the light emitted from the backlight module, in an embodiment of the present embodiment, the pitch between two adjacent ridges is 20-48 μm, but the present invention is not limited thereto.

Referring to fig. 6, in the present embodiment, the prism layer includes a plurality of prism units 10 arranged periodically along a second direction perpendicular to the first direction, and a height of each of the plurality of prisms in the prism unit 10 in a light outgoing direction (Z direction in fig. 6) of the backlight is different.

If the heights of the prisms in the light-emitting direction (Z direction in fig. 5) of the backlight are the same, after the assembly, each prism is in contact with the film structure located on the light-emitting side of the prism layer, in this embodiment, the heights of the prisms in each prism unit 10 in the light-emitting direction (Z direction in fig. 5) of the backlight are different, that is, the prism with a lower height in the light-emitting direction (Z direction in fig. 5) of the backlight is not in contact with the film structure located on the light-emitting side of the prism layer, so that the contact area between the prism layer and the film structure located on the light-emitting side of the prism layer is reduced, and the abnormal display is avoided.

The plurality of prisms in each prism unit 10 may have only one first prism, the height of the first prism is higher than that of the other prisms except the first prism, the first prism may be located at the middle position of the corresponding prism unit 10 or near the edge position of the other prism units 10, and if the prism unit 10 is located at the edge of the prism layer, the first prism may also be located near the edge of the prism layer.

The plurality of prisms in each prism unit 10 may have only at least two first prisms, and at least two first prisms may be disposed adjacent to each other or may be disposed at intervals.

It should be noted that the number of the first prisms is smaller than the number of the prisms in the corresponding prism unit, and in order to avoid the occurrence of the abnormal phenomenon, in some embodiments, the number of the first prisms is smaller than half of the number of the prisms in the prism unit, but not limited thereto.

In the present embodiment, for example, in the direction perpendicular to the first direction, the vertex of the ridge of each prism is shifted to the side close to the first connection surface 14, or the vertex of the ridge of each prism is shifted to the side close to the second connection surface 15.

With the above technical solution, the viewing angle of the side of the backlight module close to the first connecting surface 14 in the direction perpendicular to the first direction (i.e. the direction perpendicular to the extending direction of the prism) is larger than the viewing angle of the side of the backlight module far from the first connecting surface 14, i.e. the viewing angle is biased towards the side of the backlight module close to the first connecting surface 14 in the direction perpendicular to the first direction. Alternatively, the viewing angle of the side of the backlight module close to the second connection surface 15 is larger than the viewing angle of the side of the backlight module far from the second connection surface 15, that is, in the direction perpendicular to the first direction, the viewing angle is deviated to the side of the backlight module close to the second connection surface 15. In fig. 17, an orthogonal projection of the apex of the ridge of each of the prisms on the bottom surface 11 is located on the right side of the center of the bottom surface (i.e., the center line in the direction perpendicular to the extending direction of the prism), that is, the apex of the ridge of each of the prisms is shifted to the side closer to the second connection surface 15. The extending direction of the prism is generally the long side direction of the display screen, and by adopting the technical scheme, the visual angle of any one side of two sides in the short side direction of the display screen is larger, so that the special requirements of customers are met.

Referring to fig. 17, in the present embodiment, for example, in a direction perpendicular to the first direction, the prism layer has a first center line 101, a vertex of each prism of the prisms is shifted to a side close to the first center line 101, and the farther the distance from the first center line 101 is, the smaller the shift amount of the vertex of the prism is, so as to ensure the brightness of the light with a large viewing angle.

Every the summit of the arris peak of prism is to being close to one side skew of first central line 101, the summit is close to one side of first central line, it is stronger to assemble light, and the summit is kept away from one side increase visual angle range of first central line is bigger, adopts above-mentioned technical scheme, can increase the light intensity of the emergent light of backlight unit central point, and the emergent light of big visual angle of increase (the side that the slope is high strengthens, the little side angle increase of slope).

In this embodiment, exemplarily, in a direction perpendicular to the first direction, heights of the plurality of prisms in a direction parallel to the light exit direction of the backlight are gradually reduced from the middle to both sides, referring to fig. 18.

By adopting the technical scheme, the brightness of emergent light at the center of the backlight module can be increased, and the visual angles of emergent light at two sides of the backlight module are increased.

Referring to fig. 20, an embodiment of the present invention further provides a display device, including the backlight module and the display panel 101, where the display panel 101 is disposed on a light emitting side of the backlight module.

It should be noted that, in this embodiment, the light emitting side is relative to the whole backlight module.

In this embodiment, the backlight module includes a light guide plate 104 and a light source 108, the light guide plate 104 includes a light incident surface and a light emitting surface, the light source 108 is located at one side of the light incident surface of the light guide plate 104, in some embodiments, the light incident surface and the light emitting surface are disposed adjacent to each other (refer to fig. 20), that is, the backlight module is a side-in type backlight, and in some embodiments, the light incident surface and the light emitting surface are disposed opposite to each other, that is, the backlight module is a direct type backlight.

The backlight module further comprises a back plate 106 arranged around the light guide plate 104, a reflector plate 105 is arranged on the backlight side of the light guide plate 104, the back plate 106 comprises a bottom plate, a side plate connected with the bottom plate and a top plate connected with the side plate, and a reflection film layer 109 is arranged on one side of the top plate close to the bottom plate to prevent light leakage and increase the utilization rate of light.

In this embodiment, the display device is further disposed on the polarizer 102 on the backlight side of the display panel 101;

the optical structure 103 comprises a first diffusion layer 2, a prism layer 01 and a second diffusion layer 3 which are sequentially stacked along the direction away from the backlight source;

a brightness enhancement film 4 is integrally disposed on the polarizer 102.

The brightness enhancement film 4 is integrated on the polarizer 102, and then along the light-emitting direction of the backlight module, the optical structure 103 comprises a first diffusion layer 2, a prism layer 01 and a second diffusion layer 3 which are sequentially overlapped, and relative to the optical structure 103 comprising the first diffusion layer 2, the prism layer 01, the second diffusion layer 3 and the brightness enhancement film 4 which are sequentially overlapped, the position relation of the brightness enhancement film 4 is changed, but the half-height wide viewing angle is also increased, and the brightness of the central point is ensured.

In the embodiment, the polarizer 102 includes a polarizing film layer and a substrate layer sequentially stacked in a direction away from the display panel 101, and the brightness enhancement film 4 is disposed between the polarizing film layer and the substrate layer, or the brightness enhancement film 4 is disposed on a side of the polarizing film layer away from the substrate layer.

Along keeping away from display panel 101's direction, the polarisation rete is stromatolite in proper order and is set up APF film (ultra-thin optical film of reflection-type polarisation), first TAC film (cellulose triacetate membrane), PVA film (polyvinyl alcohol film) and second TAC film, the APF film with bond through PSA (pressure sensitive adhesive) between the first TAC film, the second TAC film is kept away from one side of PVA film is provided with PSA pressure sensitive adhesive, in order to be used for with display panel 101 bonds, brightness enhancement film 4 is located the APF film is kept away from one side of first TAC film.

When the brightness enhancement film 4 is used as a part of the optical structure, the brightness enhancement film 4 cannot be directly disposed on the surface of the second diffusion layer, but needs to be disposed on a substrate to ensure the smoothness of the film layer, and is connected with the second diffusion layer through the substrate.

The display device may be: the display device comprises any product or component with a display function, such as a liquid crystal television, a liquid crystal display, a digital photo frame, a mobile phone, a tablet computer and the like, wherein the display device further comprises a flexible circuit board, a printed circuit board and a back plate.

It will be understood that the above embodiments are merely exemplary embodiments taken to illustrate the principles of the present invention, which is not limited thereto. It will be apparent to those skilled in the art that various modifications and improvements can be made without departing from the spirit and substance of the invention, and these modifications and improvements are also considered to be within the scope of the invention.

Claims

1. The utility model provides a backlight module, its characterized in that, including the backlight with set up in the optical structure of the light-emitting side of backlight, optical structure includes the prism layer, the prism layer includes a plurality of prisms that extend along first direction, the prism include the bottom surface, and with the arris peak that the relative one side of bottom surface set up, the arris peak is including being located the first connection face and the second connection face of the both sides at the summit of arris peak, the prism is along perpendicular to on the cross-section of bottom surface direction, first connection face is kept away from the one end at the summit of arris peak with line between the summit of arris peak is first line, the second connection face is kept away from the one end at the summit of arris peak with line between the summit of arris peak is the second line, first line with contained angle between the second line is the obtuse angle.

2. The backlight module according to claim 1, wherein the optical structure further comprises a first diffusion layer on the backlight side of the prism layer and/or a second diffusion layer on the light-emitting side of the prism layer, the haze of the first diffusion layer is 90% -95%, and the haze of the second diffusion layer is 90% -110% of that of the first diffusion layer.

3. A backlight module according to claim 1 or 2, wherein the optical structure further comprises a brightness enhancement film on the light exit side of the prism layer.

4. A backlight module according to claim 2, wherein the optical structure comprises a first diffuser layer, a prism layer, a second diffuser layer and a brightness enhancement film stacked in that order in a direction away from the backlight source.

5. The backlight module according to claim 4, wherein in a plane parallel to the first direction and parallel to the light-emitting direction of the backlight source, the brightness of a first viewing angle is half of the central brightness of the backlight module, and the first viewing angle is greater than or equal to |45 ° |, and/or

6. The backlight module according to claim 1, wherein the first connecting surface is a curved surface having a radius of 5-9 um.

7. The backlight module according to claim 1, wherein the first connecting surface is a plane, and an included angle between the first connecting surface and the second connecting surface is 110 ° to 130 °.

8. The backlight module according to claim 7, wherein the prism comprises a first inclined surface and a second inclined surface between the bottom surface and the ridge, the first inclined surface and the first connecting surface are located on the same side of the vertex of the ridge, the included angle between the first inclined surface and the first connecting surface is an obtuse angle, the second inclined surface and the second connecting surface are located on the same side of the vertex of the ridge, and the included angle between the second inclined surface and the second connecting surface is an obtuse angle;

9. A backlight module according to claim 1, wherein the pitch between two adjacent ridges is 20-48 μm.

10. The backlight module as claimed in claim 1, wherein the backlight source comprises a light source, and the light source is a blue LED with a peak wavelength of 460um or more.

11. The backlight module according to claim 1, wherein the prism layer comprises a plurality of prism units arranged periodically along a second direction perpendicular to the first direction, and a plurality of prisms in each of the prism units have different heights in a light-emitting direction of the backlight source.

12. A backlight module according to claim 1, wherein the vertex of the ridge of each of the prisms is shifted to a side closer to the first connection surface or the vertex of the ridge of each of the prisms is shifted to a side closer to the second connection surface in a direction perpendicular to the first direction.

13. The backlight module according to claim 1, wherein the prism layer has a first central line in a direction perpendicular to the first direction, and the vertex of each of the prisms is shifted to a side closer to the first central line, and the farther the distance from the first central line, the smaller the shift amount of the vertex of the prism is.

14. The backlight module according to claim 1, wherein the height of the prisms in the direction parallel to the light exit direction of the backlight source gradually decreases from the middle to both sides in the direction perpendicular to the first direction.

15. A display device comprising the backlight module of any one of claims 1-14 and a display panel, wherein the display panel is disposed on the light-emitting side of the backlight module.

16. The display device according to claim 15, wherein the display device is further provided with a polarizer on a backlight side of the display panel;

and a brightness enhancement film is integrated on the polarizer.

17. The display device according to claim 16, wherein the polarizer comprises a polarizing film layer and a substrate layer sequentially stacked in a direction away from the display panel, and the brightness enhancement film is disposed between the polarizing film layer and the substrate layer, or the brightness enhancement film is disposed on a side of the polarizing film layer away from the substrate layer.