TWI793007B - Backlight module and display device - Google Patents

Abstract

A backlight module including a back cover having at least one sidewall, a light guide plate disposed in the back cover with a reserved space between the light guide plate and the sidewall of the back cover, and a reflective sheet disposed between the back cover and the light guide plate. The reflective sheet includes an underlying part, an extension part and a supporting part, wherein the underlying part lies between the back cover and the light guide plate, the extension part and the supporting part lie in the reserved space, and at least one part of the supporting part leans against the sidewall of the back cover. A display device including the backlight module is also provided in the present invention.

Description

Backlight module and display device

The present invention is generally related to a backlight module, more specifically, it relates to a backlight module with a reflective sheet with multiple folds and a display device using the backlight module

Display panels and panel display devices using display panels have gradually become the mainstream of various display devices. For example, various panel displays, flat-screen TVs for home use, flat-panel monitors for personal computers and laptops, display screens for mobile phones and digital cameras, etc., are products that use a large number of display panels. Especially in recent years, the market demand for liquid crystal display devices has grown significantly. In order to meet the functional and appearance requirements of liquid crystal display devices, the designs of backlight modules used in liquid crystal display devices are also increasingly diversified.

Generally, the common backlight modules in the market can be divided into side-type and direct-type according to the incident position of the light source, so as to provide a uniform surface light source for the liquid crystal display module installed thereon. The side-type backlight module usually includes components such as a backplane, a light guide plate, a reflector, and a plastic frame. There is usually a reserved space between the walls to set other components or to provide thermal expansion margin in subsequent reliability tests.

Side-lit backlight module, as the name suggests, its light source (such as LED grain or cold cathode fluorescent lamp CCFL) is incident from one side of the light guide plate, and the side light source is converted into A surface light source facing the LCD module. The reflector can be designed to have integrally formed hem parts extending It extends to the reserved space between the side wall of the back panel and the side of the light guide plate to reflect the light emitted from the side of the light guide plate to enhance the luminance of the light-emitting surface. However, the disadvantage of such reflective sheet design is that the folded edge of the reflective sheet protrudes into the reserved space between the light guide plate and the back plate but cannot be close to the side of the light guide plate, and is inclined toward the side wall of the back plate, which is difficult to maintain. The set reflection angle will cause the problem of uneven reflected light or bright lines near the edge of the light-emitting surface of the light guide plate.

In view of the shortcomings of the aforementioned conventional methods, the present invention hereby proposes a novel backlight module structure, which is characterized in that the edge of the reflector of the backlight module has at least two or more fold lines, which match the limit on the side wall of the backplane. The bit design can maintain the preset reflection angle of the reflector to achieve better optical taste.

One aspect of the present invention is to propose a backlight module, the structure of which includes a backplane with at least one side wall and a light guide plate disposed in the backplane. A reserved space and a reflective sheet are arranged between the backplane and the light guide plate, the reflective sheet includes a substrate part, an extension part and a support part, the substrate part is located between the backplane and the light guide plate Between, the extension part and the support part are located in the reserved space, at least a part of the support part leans against the side wall of the backboard.

Another aspect of the present invention is to provide a display device, which includes the above-mentioned backlight module and a display panel disposed above the backlight module.

These and other objects of the present invention will become more apparent to the reader after reading the following detailed description of the preferred embodiment which is depicted in various drawings and drawings.

1: Backplane

2: Light guide plate

3: reflector

11: Bottom

12: side wall

31: substrate part

32: Extension

32a: first surface

32b: second surface

33: support part

121: convex part

121a: concave part

121b: Groove

D: reserved space

L1: the first polyline

L2: the second polyline

θ ₁ : first angle

θ ₂ : second angle

This specification contains drawings and constitutes a part of this specification, so that readers can have a further understanding of the embodiments of the present invention. The drawings depict some embodiments of the invention and together with the description herein explain its principles. In these drawings: Figure 1 is a schematic cross-sectional view of a backlight module according to an embodiment of the present invention; Figure 2 is a schematic cross-sectional view of a backlight module according to another embodiment of the present invention; and Figure 3 It is a schematic cross-sectional view of a backlight module according to yet another embodiment of the present invention; it should be noted that all the figures in this specification are illustrations in nature. The proportions may be exaggerated or reduced, and in general, the same reference symbols in the drawings are used to designate corresponding or similar component features in modified or different embodiments.

Exemplary embodiments of the present invention will now be described in detail below, which will illustrate the described features with reference to the accompanying drawings for readers to understand and achieve technical effects. Readers will understand that the description herein is by way of illustration only and is not intended to limit the present case. Various embodiments of the present application and various features that do not conflict with each other in the embodiments can be combined or rearranged in various ways. Without departing from the spirit and scope of the present invention, modifications, equivalents or improvements to the present invention will be understood by those skilled in the art and are intended to be included within the scope of the present invention.

Readers should be able to easily understand that the meanings of "on", "on" and "above" in this case should be interpreted in a broad way so that "on" not only means "directly on "Something "on" also includes the meaning of "on" something with an intervening feature or layer in between, and "on" or "over" not only means "on" something or The meaning of "over" and may also include its meaning of "on" or "over" something without intervening features or layers in between (ie, directly on something).

In addition, spatial relative terms such as "under", "beneath", "lower", "above", "upper", etc. may be used herein for convenience of description to describe the relationship between one element or feature and another. The relationship of one or more elements or features as shown in the drawings.

Readers can usually understand a term at least in part from its usage in context. For example, the term "one or more" as used herein may be used in the singular to describe any feature, structure or characteristic or may be used in the plural to describe a combination of features, structures or characteristics, depending at least in part on the context. Similarly, terms such as "a," "an," "the" or "said" may equally be read to convey either the singular usage or the plural usage, depending at least in part on the context. Additionally, the term "based on" may be understood as not necessarily intended to convey an exclusive set of factors, but may allow for the presence of additional factors not necessarily explicitly described, again depending at least in part on context.

Readers can better understand that when words such as "comprising" and/or "comprising" are used in this specification, it clearly states the existence of the stated features, regions, integers, steps, operations, elements and/or components, but does not The existence or addition of one or more other features, regions, integers, steps, operations, elements, components and/or combinations thereof is not excluded.

Please refer now to FIG. 1 , which is a schematic cross-sectional view of a backlight module according to an embodiment of the present invention. As shown in FIG. 1 , the backlight module proposed by the present invention generally includes a backplane 1 , a light guide plate 2 and a reflection sheet 3 . The backboard 1 can be a board body made of rigid materials such as metal, and has predetermined mechanical strength and supporting force. The light guide plate 2 can be a plate structure made of transparent polymer material, which can guide the side incident light source to the light output surface of the light guide plate through the principle of total reflection. The reflective sheet 3 can be a white reflective film, which has high reflectivity and low transmittance, and can reflect light from the bottom or side of the light guide plate 2 back into the light guide plate 2 . In the embodiment of the present invention, the edge of the reflective sheet 3 can be concavely folded along the folding line to reflect the lateral light leakage, and the concave folding method will be described in detail later.

In terms of positional relationship, the light guide plate 2 is arranged in the accommodating space on the backplane 1, and its surroundings are surrounded by the side walls 12 of the backplane 1 (Figure 1 only shows one of the side walls 12 and part of them. light guide plate 2), and There is a reserved space D between the light guide plate 2 and the side wall 12 . It should be noted that in an actual backlight module, other optical films may be provided on the light-emitting surface of the light guide plate 2, such as a diffusion film, a color conversion film, and a thinning film. In addition, the backplane 1 can also be combined with a plastic frame. Since the above-mentioned components are not the focus of the present invention, these components will not be shown in the illustration of the present invention for the sake of brevity and avoid obscuring the focus of the present invention.

One of the characteristics of the present invention is that the edge of the reflection sheet 3 has more than two fold lines. Taking two fold lines as an example, as shown in Figure 1, the reflection sheet 3 includes a base portion 31, an extension portion 32, and a support portion 33, wherein the first fold line L1 is located between the base portion 31 and the extension portion 32, The second folding line L2 is located between the extension portion 32 and the support portion 33 . The substrate portion 31 is the main body of the reflective sheet 3 , which is located between the back of the light guide plate 2 and the bottom 11 of the backplane 1 . One end of the extension portion 32 is connected to the substrate portion 31 , and the other end extends into the reserved space D. As shown in FIG. One end of the support portion 33 is connected to the extension portion 32 , and the other end (or at least a part thereof) leans against the side wall 12 of the backboard 1 . More specifically, in the embodiment of the present invention, the reflective sheet 3 is preferably made of elastic material, and more preferably, the reflective sheet 3 is integrally formed. More specifically, the substrate portion 31 and the extension portion 32 of the reflection sheet 3 can be bent to form any angle, and the extension portion 32 and the support portion 33 can also be bent to form any angle, and the elasticity of the reflection sheet 3 can be used to make the extension There is a supporting force between the part 32 and the supporting part 33, so that the extension section 32 can be made as close as possible to the side of the light guide plate 2, so as to maintain the preset reflection angle of the reflective sheet 3 relative to the light guide plate 2, and enhance the light guide plate 2. The effect of light uniformity. In addition, the positions of the first fold line and the second fold line of the reflection sheet 3 can also be elastically compatible and applicable to designs with different sizes of backlight modules or sizes of the reserved space D.

In one embodiment, the extension portion 32 has a first surface 32a facing the light guide plate 2 and a second surface 32b facing the backplane 1 , and there is a first angle θ between the substrate portion 31 and the first surface 32a of the extension portion 32 _1. There is a second angle θ ₂ between the support portion 33 and the second surface 32b of the extension portion 32 , and the first angle θ ₁ is preferably larger than the second angle θ ₂ . In the actual setting, the extension part 32 and the support part 33 located in the reserved space D can be elastically bent into any first angle θ ₁ and second angle θ ₂ , and one end of the support part 33 can lean against the back The way on the side wall 12 of the board 1 is used to realize the effect of position limitation and fixation. In another embodiment, a crimping line, a rice line or a bridging line can be made along the first folding line L1 or the second folding line L2, so that the substrate part 31 and the extension part 32 can be accurately concave-folded later. The first fold line L1 between them and the second fold line L2 between the extension portion 32 and the support portion 33 . More specifically, the first fold line L1 is a valley fold line, and the second fold line L2 is a mountain fold line, so that the base portion 31 of the reflective sheet 3 is covered by the light guide plate 2, and the extension portion 32 and the support portion 33 extend into the pre-surface. In the space D, use the elasticity of the reflective sheet 3 to make the other end of the supporting part 33 push against the side wall 12 to provide a supporting force for the extending part 32. In this way, the extending part 32 can be made as close as possible to the side of the light guide plate 2, so as to The preset reflection angle of the reflective sheet 3 relative to the light guide plate 2 is maintained to achieve better optical quality.

In order to achieve the best effect of reflecting light from the light guide plate 2, the first angle _θ1 is preferably adapted to the angle between the bottom surface and the side surface of the light guide plate 2, for example, 90 degrees. However, in an actual setting, the supporting force between the extension part 32 and the supporting part 33 is maintained through the elasticity of the reflective sheet 3, and usually the first angle _θ1 is greater than the second angle _θ2 and greater than 90 degrees. In this way, the other end of the support portion 33 is pressed against the side wall 12 by using the elasticity of the reflective sheet 3 to provide a supporting force for the extension portion 32, and the extension portion 32 of the reflective sheet 3 can be fixed and maintained at the optimal preset of the reflected light. Angle, it is not easy to tilt towards the side wall of the back panel 1 to change the reflection angle and reduce the effect of reflecting light as in the prior art.

In addition, the height of the connection between the extension part 32 and the support part 33 in the reflective sheet 3 is preferably the same as the height of the top surface of the light guide plate 2, so as to ensure that the light leaking from the side of the light guide plate can be reflected back into the light guide plate, and maintain the backlight. The effect of the brightness of the module.

In the present invention, additional stoppers or features may be formed on the side wall 12 of the back panel 1 to help maintain the position of the support portion 33 of the reflective sheet 3 relative to the side wall 12 . For example, as shown in FIG. 1 , a convex portion 121 is formed on the sidewall 12 of the backplane 1 , which protrudes toward the direction of the light guide plate 2 and can contact the supporting portion 33 . During the installation process of the reflective sheet 3, by abutting one end of the support portion 33 against the side wall 12 of the back panel 1, the extension portion 32 of the reflective sheet 3 and the support portion 33 will naturally fold in the reserved space D. It is fixed at a specific first angle _θ1 and a second angle _θ2 , and at least a part of the support portion 33 of the reflective sheet 3 after fixing is in contact with the convex portion 121 and leans against it. In addition, the height of the connection between the extension portion 32 and the support portion 33 of the reflective sheet 3 is preferably higher than the height of the position of the protrusion 121 , so that the feature-limiting effect of the protrusion 121 can be better exerted. The advantage of this design is that with the help of the convex portion 121 on the side wall 12 , the attachment material between the side wall 12 and the reflection sheet 3 can be omitted.

Now please refer to FIG. 2 , which is a schematic cross-sectional view of a backlight module according to another embodiment of the present invention. As shown in Figure 2, the structure and components of the backlight module in this embodiment are similar to those shown in the embodiment in Figure 1, the difference lies in that a recess is formed on the side wall 12 of the back panel 1 in the embodiment in Figure 1 121a. In other words, whether it is the concave portion 121a in this embodiment or the above-mentioned convex portion 121, the level difference on the side wall 12 of the back panel 1 is used to make one end of the support portion 33 of the reflective sheet 3 abut against the concave portion 121a. and adjust its position elastically and naturally in the reserved space D, finally achieving the effect of fixing the extension part 32 and the support part 33 of the reflection sheet 3 . The advantages of this design are the same as those shown in the embodiment shown in FIG. 1. With the help of the feature of the concave portion 121a on the side wall 12, the attachment material between the side wall 12 and the reflection sheet 3 can also be omitted. Compared with the one in FIG. 1 The convex part 121 and the concave part 121a of this embodiment can also ensure the space between the side wall 12 of the backplane 1 and the light guide plate 2, which is beneficial to reserve the convenience of installing other components.

Now please refer to FIG. 3 , which is a schematic cross-sectional view of a backlight module according to another embodiment of the present invention. As shown in Figure 3, the structure and components of the backlight module in this embodiment are similar to those shown in the embodiment in Figure 2. The difference lies in that in the embodiment in Figure 3, a Groove 121b features. In an embodiment, the end of the support portion 33 of the reflective sheet 3 may abut against or be directly embedded in the groove 121 b to achieve the effect of fixing the extension portion 32 of the reflective sheet 3 and the support portion 33 . For example, the groove 121b is a plurality of holes on the surface of the side wall 12 or a whole channel, and the supporting part 33 is located at the end of the reflective sheet 3 and embedded in the aforementioned groove 121b, so that not only the side wall 12 and the reflection The sticking material between the sheets 3 can also ensure that the end of the reflective sheet 3 has a more stable limiting effect relative to the back plate 1 .

Based on the above-mentioned embodiments, the present invention has at least two or more broken line designs on the edge of the reflection sheet of the backlight module, which is matched with the method of forming limiting features such as protrusions, recesses or grooves on the side wall of the back panel to achieve Maintain the effect of the preset reflection angle of the reflector, and be flexibly compatible with different backlight module sizes or reserved space sizes, and reduce the amount of materials and materials used to fix the folded edges of the reflector The relevant manufacturing process is an inventive idea with both novelty and progress.

In addition to the foregoing embodiments, the present invention also provides a display device, which includes the backlight module described in the above embodiments and all its features, and a display panel disposed above the backlight module.

The above descriptions are only preferred embodiments of the present invention, and all equivalent changes and modifications made according to the scope of the patent application of the present invention shall fall within the scope of the present invention.

1: Backplane

2: Light guide plate

3: reflector

11: Bottom

12: side wall

31: substrate part

32: Extension

32a: first surface

32b: second surface

33: support part

121: convex part

D: reserved space

L1: the first polyline

L2: the second polyline

θ ₁ : first angle

θ ₂ : second angle

Claims (7)

A backlight module, comprising: a back plate with at least one side wall; a light guide plate arranged in the back plate, with a reserved space between the light guide plate and the side wall of the back plate; and a reflective sheet , arranged between the back plate and the light guide plate, the reflector includes a substrate portion, an extension portion and a support portion, the substrate portion is located between the back plate and the light guide plate, the extension portion and the support portion Located in the reserved space, at least a part of the supporting part is against the side wall of the backboard; wherein there is a protrusion or a groove on the side wall of the backboard, and a part of the supporting part is against the side wall of the backboard. Lean on the protrusion or the groove. The backlight module as described in item 1 of the scope of the patent application, wherein the extension part has a first surface facing the light guide plate and a second surface facing the back plate, and the substrate part is opposite to the first surface of the extension part There is a first angle θ ₁ therebetween, and there is a second angle θ ₂ between the support portion and the second surface of the extension portion, and the first angle θ ₁ is larger than the second angle θ ₂ . The backlight module as described in item 1 of the scope of the patent application, wherein the height of the connection between the extension part and the support part is higher than the height of the protrusion or the groove. The backlight module as described in claim 1 of the patent application, wherein the height of the connection between the extension part and the support part is the same as the height of the top surface of the light guide plate. The backlight module as described in item 1 of the scope of the patent application, wherein there is a valley fold line between the base portion and the extension portion. The backlight module as described in item 1 of the scope of the patent application, wherein there is a mountain fold line between the extension part and the support part. A display device, comprising: a backlight module as described in any one of items 1 to 6 of the scope of the patent application; and a display panel arranged above the backlight module.

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