CN114419994A - Backlight module - Google Patents

Abstract

The invention discloses a backlight module, which comprises a plurality of light sources, a diffusion plate and a plurality of shading composite layers. The diffusion plate is located above the light source. The shading composite layer is positioned on the diffusion plate and respectively corresponds to the light source positions. The width of each light-shielding composite layer is gradually reduced from the diffusion plate to the direction far away from the light source.

Description

Backlight Module

technical field

The present invention relates to a backlight module.

Background technique

In recent years, the types of light sources used in backlight modules have become more and more diverse. For example, mini LEDs can be used in backlight modules of display devices. In order to prevent the area corresponding to the light source from being too bright, generally speaking, a diffuser plate can be arranged above the light source to make the light uniform.

Although the ink pattern (Pattern) on the diffuser plate can have the effect of blocking the light of the light source, however, due to the current screen printing technology, the thickness of the ink used to form the pattern of the diffuser plate is mostly flat or concave, so that through the ink The light of the pattern is not uniform, and it is easy to produce a situation where the light source is bright above and the edge is dark. When the backlight unit is turned on, you may see defective images caused by uneven brightness, such as LED mura.

SUMMARY OF THE INVENTION

A technical aspect of the present invention is a backlight module.

According to some embodiments of the present invention, a backlight module includes a plurality of light sources, a diffusion plate and a plurality of light-shielding composite layers. The diffuser plate is located above the light source. The light-shielding composite layers are located on the diffuser plate and correspond to the positions of the light sources respectively. The width of each light-shielding composite layer gradually decreases from the diffuser plate to the direction away from the light source.

In some embodiments, each light-shielding composite layer described above includes a plurality of sub-light-shielding layers. The width of the uppermost layer of these sub-light shielding layers is larger than the width of the corresponding light source.

In some embodiments, the above-mentioned sub light shielding layers have different shapes.

In some embodiments, the above-mentioned sub light shielding layers have the same thickness.

In some embodiments, the above-mentioned sub-light shielding layers have different transmittances.

In some embodiments, the sub-light-shielding layer includes a lower layer and an upper layer on the lower layer, and the density of the upper layer is greater than that of the lower layer.

In some embodiments, the above-mentioned light sources are respectively within the orthographic profile of the light-shielding composite layer.

In some embodiments, the distance between two adjacent light sources along the first direction is smaller than the distance between adjacent two light sources along the second direction.

In some embodiments, the length direction of each light-shielding composite layer is the same as the first direction.

In some embodiments, the width direction of each light-shielding composite layer is the same as the second direction.

In the above embodiments of the present invention, since the backlight module has light-shielding composite layers located on the diffuser plate and corresponding to the positions of the light sources, and the width of the light-shielding composite layers gradually decreases from the diffuser plate to the direction away from the light source, the light-shielding composite layers The central area is thicker and the edge area is thinner, so that the central area of the light-shielding composite layer has a better light-shielding effect. In this way, when the light source under the light-shielding composite layer emits light, although the light source illuminates the central area of the light-shielding composite layer more and the edge area of the light-shielding composite layer is less, the width of the light-shielding composite layer changes, so that the The central area of the light-shielding composite layer can block more light, and the edge area can block less light to achieve the effect of uniform light, which can overcome the problem of defective images (such as LED mura) caused by uneven brightness. In addition, the light-shielding composite layer can be printed multiple times, which is convenient for production.

The present invention is described in detail below with reference to the accompanying drawings and specific embodiments, but is not intended to limit the present invention.

Description of drawings

Aspects of the present disclosure are best understood from the following description when read in conjunction with the accompanying drawings. Note that in accordance with standard practice in the industry, the various features are not drawn to scale. In fact, the dimensions of the various features may be arbitrarily increased or decreased for clarity of discussion.

FIG. 1 is a cross-sectional view of a backlight module according to an embodiment of the present invention.

FIG. 2 is a perspective view of the light-shielding composite layer of FIG. 1 .

3 is a perspective view of a light-shielding composite layer according to another embodiment of the present invention.

FIG. 4 is a top view of a light-shielding composite layer according to yet another embodiment of the present invention.

FIG. 5 is a top view of the light-shielding composite layer of FIG. 4 after the lower layer is formed and before the upper layer is formed.

FIG. 6 is a top view of a light-shielding composite layer according to still another embodiment of the present invention.

where the reference number

100: Backlight module

110: Light source

120: Diffuser plate

130, 130a, 130b, 130c: Light-shielding composite layers

132, 132a, 132b: sub light shielding layers

134, 134a, 134b: sub light shielding layers

136a, 138a: sub light shielding layer

140: Substrate

150: encapsulant

160: Colloid

A: Contour range

D: direction

D1: first direction

D2: second direction

d1, d2: distance

H: Thickness

W1, W2, W3: width

Detailed ways

The technical solution of the present invention will be described in detail below in conjunction with the accompanying drawings and specific embodiments, so as to further understand the purpose, solution and effect of the present invention, but it is not intended to limit the protection scope of the appended claims of the present invention.

The embodiments disclosed below provide many different embodiments, or examples, for implementing different features of the presented subject matter. Specific examples of elements and arrangements are described below to simplify the present case. Of course, these examples are merely examples and are not intended to be limiting. In addition, reference numerals and/or letters may be repeated in various instances herein. This repetition is for brevity and clarity, and does not in itself specify the relationship between the various embodiments and/or configurations discussed.

Spatially relative terms such as "below," "below," "lower," "above," "above," and the like may be used herein for descriptive purposes to describe The relationship of one element or feature to another element or feature as shown in the figures. The spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation shown in the figures. The device may be otherwise oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein interpreted accordingly.

FIG. 1 is a cross-sectional view of a backlight module 100 according to an embodiment of the present invention. FIG. 2 is a perspective view of the light-shielding composite layer 130 of FIG. 1 . Referring to FIGS. 1 and 2 simultaneously, the backlight module 100 includes a plurality of light sources 110 , a diffusion plate 120 and a plurality of light-shielding composite layers 130 . The light source 110 may be a point light source, such as LED or Mini LED. The diffuser plate 120 is located above the light source 110 . The light-shielding composite layers 130 are located on the diffuser plate 120 and correspond to the positions of the light sources 110 respectively. As shown in FIG. 1 , the light-shielding composite layers 130 and the light sources 110 have the same number and are aligned in the vertical direction. In this embodiment, the backlight module 100 has six light-shielding composite layers 130 and six light sources 110 , but the present invention is not limited thereto. In addition, the width of each light-shielding composite layer 130 gradually decreases from the diffusion plate 120 to the direction D away from the light source 110 . With such a design, the thickness of the central region of the light-shielding composite layer 130 can be greater than that of the edge region. Herein, the central area of the light-shielding composite layer 130 may refer to the area directly above the light source 110 , and the edge area of the light-shielding composite layer 130 may refer to the area where the light source 110 surrounds the central area and does not vertically overlap the light source 110 .

The light-shielding composite layer 130 can be formed by multiple screen printing, for example, two screen printings, so as to form the structure as shown in FIG. 2 . The material of the light-shielding composite layer 130 may be ink. In this embodiment, each light-shielding composite layer 130 includes a plurality of sub-light-shielding layers 132 and 134 . The width W1 of the lower sub-light-shielding layer 132 is greater than the width W2 of the upper sub-light-shielding layer 134 , so that the thickness of the central region of the light-shielding composite layer 130 is greater than that of the edge region. For example, the sub light shielding layers 132, 134 may have the same thickness H. In this way, the central region of the light-shielding composite layer 130 can have twice the thickness H, which is the total thickness 2H of the sub-light-shielding layers 132 and 134, eg, 15 to 45 μm, and the edge region of the light-shielding composite layer 130 has a thickness H, which is The thickness H of the lower sub-light shielding layer 132 .

Specifically, since the backlight module 100 has light-shielding composite layers 130 located on the diffuser plate 120 and corresponding to the positions of the light sources 110 , and the width of the light-shielding composite layers 130 gradually decreases from the diffuser plate 120 to the direction D away from the light source 110 , Therefore, the central region of the light-shielding composite layer 130 is thicker and the edge region is thinner, so that the central region of the light-shielding composite layer 130 has a better light-shielding effect. As a result, when the light source 110 under the light-shielding composite layer 130 emits light, although the light source 110 illuminates the central region of the light-shielding composite layer 130 with more light, and illuminates the edge region of the light-shielding composite layer 130 with less light, the light-shielding composite layer 130 emits less light. The width of 130 changes, so that the central area of the light-shielding composite layer 130 can block more light, and the edge area can block less light, so as to achieve the effect of uniform light, which can overcome the defective picture (such as LED mura) caused by uneven brightness. )question. The light-shielding composite layer 130 can be printed multiple times, which is convenient to manufacture.

In this embodiment, the width W2 of the uppermost layer of the sub light shielding layer (ie, the sub light shielding layer 134 ) is greater than the width W3 of the corresponding light source 110 . Such a design can ensure that the light emitted directly above the light source 110 not only passes through the sub light shielding layer 132 but also passes through the sub light shielding layer 134 to enhance the light shielding effect directly above the light source 110 . Since the uppermost sub-shading layer 134 with the smallest width W2 is wider than the light source 110, and other sub-shading layers 132 are of course wider than the light source 110, the light sources 110 in FIG. The contour range A is the area between the two dotted lines in FIG. 1 .

In this embodiment, the sub light-shielding layers 132 and 134 may have the same shape, such as a circle, but not limited thereto, and a rectangle or other types of polygons may also be used. In addition, the sub light-shielding layers 132 and 134 may have the same density and the same transmittance, for example, the transmittance of 85% to 95%, but the present invention is not limited. In other embodiments, the sub-shielding layers may have different shapes, densities, and transmittances (described in FIG. 4 ).

In addition, please refer to FIG. 1 , the backlight module 100 may further include a substrate 140 , an encapsulant 150 and a glue 160 . The light source 110 is disposed on the substrate 140 . The substrate 140 can be a circuit board to supply power to the light source 110 . The encapsulant 150 covers the light source 110 to provide protection and insulation, and prevent moisture from entering. The colloid 160 can be disposed on the inner surface of the casing to support the substrate 140 and provide a buffering effect.

It should be understood that the connection relationships, materials and functions of the components already described will not be repeated, but will be described first. In the following description, other types of light-shielding composite layers will be described.

FIG. 3 is a perspective view of a light-shielding composite layer 130a according to another embodiment of the present invention. The light-shielding composite layer 130a can be formed by multiple screen printing, such as four screen printings, to form the structure as shown in FIG. 3 . The difference between this embodiment and the embodiment of FIG. 2 is that the light-shielding composite layer 130a includes four sub-light-shielding layers 132a, 134a, 136a, and 138a. The width of the sub light shielding layer 132a is greater than that of the sub light shielding layer 134a, the width of the sub light shielding layer 134a is greater than that of the sub light shielding layer 136a, and the width of the sub light shielding layer 136a is greater than that of the sub light shielding layer 138a. That is, the width of the light-shielding composite layer 130a increases sequentially from the sub-light-shielding layer 132a to the sub-light-shielding layer 134a, the sub-light-shielding layer 136a, and the sub-light-shielding layer 138a, so that the thickness of the central region of the light-shielding composite layer 130a is greater than the thickness of the edge region, To achieve the effect of uniform light.

The light-shielding composite layer 130 a of FIG. 3 can be applied to the backlight module 100 of FIG. 1 , for example, it can be substituted for the light-shielding composite layer 130 of FIG. 1 and correspond to the position of the light source 110 .

FIG. 4 is a top view of a light-shielding composite layer 130b according to yet another embodiment of the present invention. The light-shielding composite layer 130b can be formed by multiple screen printing, for example, two screen printings, so as to form the structure as shown in FIG. 4 . The difference between this embodiment and the embodiment of FIG. 2 is that the sub-light-shielding layers 132b and 134b of the light-shielding composite layer 130b have different shapes and have different transmittances. In this embodiment, the sub light shielding layer 132b is a lower layer, the sub light shielding layer 134b is an upper layer on the lower layer, and the density of the upper layer is greater than that of the lower layer. For example, the sub-light-shielding layer 132b is a circle formed by dot-shaped ink, and the sub-light-shielding layer 134b is an octagon (16-sided) formed by planar ink, so the transmittance of the sub-light-shielding layer 134b is smaller than that of the sub-light-shielding layer 132b The transmittance is helpful for blocking the light directly above the light source 110 (see FIG. 1 ).

In addition, the width of the sub light shielding layer 132b is greater than the width of the sub light shielding layer 134b. Therefore, the thickness of the central region of the light-shielding composite layer 130b is greater than that of the edge region, so as to achieve the effect of uniform light. The light-shielding composite layer 130 b of FIG. 4 can be applied to the backlight module 100 of FIG. 1 , for example, it can replace the light-shielding composite layer 130 of FIG. 1 and correspond to the position of the light source 110 .

In the following description, the steps of forming the light-shielding composite layer 130b will be described.

FIG. 5 is a top view of the lower layer (sub-light-shielding layer 132b) of the light-shielding composite layer 130b of FIG. 4 and before the upper layer (sub-light-shielding layer 134b) is formed. Referring to FIG. 4 and FIG. 5 at the same time, the diffuser plate 120 can be formed by dot-shaped screen printing ink to form the sub-light shielding layer 132b. Next, the diffusion plate 120 may be screen-printed with ink on another surface to form the sub-light-shielding layer 134b on the sub-light-shielding layer 132b. In this way, the light-shielding composite layer 130b of FIG. 4 can be obtained.

FIG. 6 is a top view of a light-shielding composite layer 130c according to still another embodiment of the present invention. The outer contour of the light-shielding composite layer 130c is shown in FIG. 6 , and the number of the stacked sub-light-shielding layers is not used to limit the present invention. The light-shielding composite layer 130c corresponds to the position of the light source 110, so that the light source 110 is covered by the light-shielding composite layer 130c. In this embodiment, the distance d1 between adjacent two light sources 110 along the first direction D1 is smaller than the distance d2 between adjacent two light sources 110 along the second direction D2, wherein the first direction D1 and the second The direction D2 is vertical. The length direction of each light-shielding composite layer 130c is the same as the first direction D1, and the width direction of each light-shielding composite layer 130c is the same as the second direction D2.

In this configuration, although the distance d1 between the two light sources 110 arranged along the first direction D1 is short, the area brightness is brighter, but the light-shielding composite layer 130c extending along the first direction D1 is arranged above, so it can effectively shield the More light, to achieve the effect of light uniformity. In addition, the distance d2 between the two light sources 110 arranged along the second direction D2 is long, resulting in a darker area. However, because the light-shielding composite layer 130c extending along the first direction D1 is disposed above, only the Block a small amount of light to achieve the effect of uniform light. The light-shielding composite layer 130 c of FIG. 6 can be applied to the backlight module 100 of FIG. 1 , for example, it can replace the light-shielding composite layer 130 of FIG. 1 and correspond to the position of the light source 110 .

Of course, the present invention can also have other various embodiments, without departing from the spirit and essence of the present invention, those skilled in the art can make various corresponding changes and modifications according to the present invention, but these corresponding Changes and deformations should belong to the protection scope of the appended claims of the present invention.

Claims (10)

1. A backlight module, comprising:

a plurality of light sources;

a diffusion plate located above the light sources; and

and the plurality of shading composite layers are positioned on the diffusion plate and respectively correspond to the light sources, wherein the width of each shading composite layer is gradually reduced from the diffusion plate to the direction far away from the light sources.

2. The backlight module as claimed in claim 1, wherein each of the light-shielding composite layers includes a plurality of light-shielding sub-layers, and a width of an uppermost layer of the light-shielding sub-layers is greater than a width of the corresponding light source.

3. The backlight module as claimed in claim 2, wherein the sub-light-shielding layers have different shapes.

4. The backlight module as claimed in claim 2, wherein the sub-light-shielding layers have the same thickness.

5. The backlight module as claimed in claim 2, wherein the sub-light-shielding layers have different transmittances.

6. The backlight module as claimed in claim 2, wherein the sub-shielding layers include a lower layer and an upper layer on the lower layer, the upper layer having a density greater than that of the lower layer.

7. The backlight module as claimed in claim 1, wherein the light sources are respectively within the range of the orthographic projection profile of the light-shielding composite layers.

8. The backlight module as claimed in claim 1, wherein a distance between two adjacent light sources along a first direction is smaller than a distance between two adjacent light sources along a second direction.

9. The backlight module as claimed in claim 8, wherein the length direction of each of the light-shielding composite layers is the same as the first direction.

10. The backlight module as claimed in claim 8, wherein the width direction of each of the light-shielding composite layers is the same as the second direction.

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