TWM608390U - Backlight module - Google Patents

Abstract

A backlight module including a light guide plate, a plurality of light sources, an optical film, a first prism sheet and a second prism sheet is provided. The light sources are disposed on a side of a light incident surface of the light guide plate, and configured to emit a plurality of light beams. The optical film is disposed on a side of a light exiting surface of the light guide plate, and includes a substrate, a plurality of upper-prism microstructures and a plurality of lower-prism microstructures. The upper-prism microstructures are disposed on the upper surface of the substrate. The lower-prism microstructures are disposed on the lower surface of the substrate, wherein an extension direction of each lower-prism microstructure and an extension direction of each upper-prism microstructure are perpendicular to each other. The first prism sheet is disposed on a side of the upper surface of the optical film, and the optical film is disposed between the light guide plate and the first prism sheet. The first prism sheet is disposed between the optical film and the second prism sheet.

Description

Backlight module

This new creation relates to an optical module, and particularly relates to a backlight module.

The main function of the light guide plate is to guide the direction of light, improve the optical brightness of the panel, and regulate the uniformity of brightness. Utilizing the total reflection characteristic of the light guide plate, after light enters the light guide plate from the light incident surface of the light guide plate, the light can be transmitted to the other end of the light guide plate. In addition, in order to control the emission of light from the light-emitting surface of the light guide plate, microstructures such as dots are arranged on the bottom surface of the light guide plate relative to the light-emitting surface. When the transmission of light encounters the dots, the light can be emitted from the light-emitting surface of the light guide plate by changing the direction of light travel.

However, how to improve the brightness efficiency so that the display can achieve the same brightness effect with less power consumption has always been the development goal of the backlight module.

The present invention provides a backlight module, which can effectively convert the light beam emitted by the light source into brightness.

An embodiment of the present invention provides a backlight module, which includes a light guide plate, a plurality of light sources, an optical film, a first film and a second film. The light guide plate has a light-incident surface, a light-emitting surface, and a bottom surface, wherein the light-incident surface is connected between the light-emitting surface and the bottom surface, and the light-emitting surface is opposite to the bottom surface. The multiple light sources are arranged on one side of the light incident surface of the light guide plate and used for emitting multiple light beams. The optical film is arranged on one side of the light emitting surface of the light guide plate, and includes a substrate, a plurality of upper microstructures and a plurality of lower microstructures. The substrate includes an upper surface and an opposite lower surface. A plurality of upper microstructures are arranged on the upper surface. A plurality of lower microstructures are arranged on the lower surface, and the extending direction of each lower microstructure and the extending direction of each upper microstructure are perpendicular to each other. The first optical film is arranged on one side of the upper surface of the optical film, and the optical film is arranged between the light guide plate and the first optical film. The first optical film is arranged between the optical film and the second optical film.

In an embodiment of the present invention, the lower microstructures of the above-mentioned optical film are in direct contact with the light-emitting surface of the light guide plate.

In an embodiment of the present invention, the cross section of each of the lower microstructures of the above-mentioned optical film in the direction perpendicular to the extension direction of the lower microstructures is an isosceles triangle.

In an embodiment of the present invention, each of the upper microstructures of the above-mentioned optical film has a light-emitting slope and a connecting slope, and the area of the light-emitting slope is larger than the area of the connecting slope.

In an embodiment of the present invention, the angle between the above-mentioned light-emitting inclined surface and the upper surface is smaller than the angle between the connecting inclined surface and the upper surface.

In an embodiment of the present invention, the upper surface or the lower surface of the above-mentioned optical film further includes a flat area. The flat area is adjacent to the light-incident surface of the light guide plate, and these upper and lower microstructures are not arranged in the flat area.

In an embodiment of the present invention, the extension direction of the lower microstructures of the above-mentioned optical film is perpendicular to the light incident surface.

In an embodiment of the present invention, the above-mentioned first film has a plurality of first film microstructures, and the extension direction of the first film microstructures is the same as the extension of the upper film microstructures of the optical film. The directions are perpendicular to each other.

In an embodiment of the present invention, the above-mentioned second scallop sheet has a plurality of second scallop microstructures, and the extension direction of these second scallop microstructures is the same as the extension of the upper scallop microstructures of the optical film. The directions are parallel to each other.

In an embodiment of the present invention, the material of the above-mentioned optical film includes diffusion particles.

Based on the above, in the backlight module of the embodiment of the present invention, since the backlight module is provided with an optical film on the light-emitting surface of the light guide plate, the optical film is provided with an upper microstructure and a lower surface respectively on the upper and lower surfaces. The microstructures of the bottom are perpendicular to each other, and the extension direction of the microstructures of the bottom is perpendicular to the direction of extension of the microstructures of the top. Therefore, the light type of the light beam of the backlight module of the embodiment of the present invention after the light is emitted from the optical film can be It is similar to the better viewing angle contour map after optical simulation.

FIG. 1 is a three-dimensional schematic diagram of a backlight module according to an embodiment of the present invention. Please refer to FIG. 1, an embodiment of the present invention provides a backlight module 100, which includes a light guide plate 120, a plurality of light sources 110, an optical film 130, a first film 140 and a second film 150. In this embodiment, a plurality of light sources 110 are arranged on one side surface of the light guide plate 120, and the light guide plate 120, the optical film 130, the first film 140 and the second film 150 are sequentially stacked.

2A and 2B are three-dimensional and cross-sectional schematic diagrams of the light guide plate of the backlight module according to an embodiment of the present invention. Please refer to FIG. 1, FIG. 2A and FIG. 2B at the same time. In this embodiment, the material of the light guide plate 120 can be plastic, glass or other suitable materials, but the invention is not limited to this. The light guide plate 120 has a light-incident surface 120S1, a light-emitting surface 120S2, and a bottom surface 120S3. The light-incident surface 120S1 is connected between the light-emitting surface 120S2 and the bottom surface 120S3, and the light-emitting surface 120S2 is opposite to the bottom surface 120S3. For example, the light-emitting surface 120S2 is parallel to The bottom surface 120S3, and the light-incident surface 120S1 is perpendicular to the light-emitting surface 120S2, but the creation of the present invention is not limited to this. In this embodiment, the light guide plate 120 may also have a plurality of side surfaces 120S4. The side surface 120S4 can be connected to the light incident surface 120S1, the light exit surface 120S2, and the bottom surface 120S3, or the side surface 120S4 can be connected to the light exit surface 120S2 and the bottom surface 120S3.

In this embodiment, the bottom surface 120S3 of the light guide plate 120 may be provided with a plurality of optical microstructures 122. The optical microstructure 122 is, for example, a dot structure or a tang structure, but the creation of the present invention is not limited to this.

Further, referring to FIG. 2B, in this embodiment, the light source 110 may be a light-emitting diode (LED) or other suitable light sources. The light source 110 is disposed on one side of the light incident surface 120S1 of the light guide plate 120, and is used to emit a plurality of light beams B. After the light beam B penetrates the light incident surface 120S1 of the light guide plate 120 and enters the light guide plate 120, the light beam B is transmitted in the light guide plate 120 in a manner of total reflection. When the light beam B is transmitted to the optical microstructure 122, the optical microstructure 122 changes the traveling direction of the light beam B, and causes the light beam B to pass through the optical surface 120S2 and transmit toward the optical film 130.

In this embodiment, the backlight module 100 may further optionally include a reflective sheet 160, and the reflective sheet 160 is disposed on one side of the bottom surface 120S3 of the light guide plate 120. Since a part of the light beam B emitted by the light source 110 is transmitted through the light guide plate 120 from the bottom surface 120S3 of the light guide plate 120 and cannot be smoothly transmitted toward the optical film 130, light energy loss is caused. Therefore, through the arrangement of the reflective sheet 160, the light beam B emitted from the bottom surface 120S3 of the light guide plate 120 can be reflected, transmitted back to the light guide plate 120 and transmitted toward the optical film 130, so as to improve the light energy utilization rate of the light source 110.

3A to 3C are three-dimensional, front-view and side-view schematic diagrams of the optical film of the backlight module according to an embodiment of the invention, respectively. Please refer to FIGS. 1, 2A, and 3A to 3C at the same time. In this embodiment, the optical film 130 is disposed on one side of the light emitting surface 120S2 of the light guide plate 120, and includes a substrate 136 and a plurality of upper microstructures 132 and a plurality of microstructures 134. In this embodiment, the material of the substrate 136 may be polyethylene terephthalate (PET), polycarbonate (PC) or other suitable materials. The material of the upper microstructure 132 and the lower microstructure 134 may be UV glue or other suitable high molecular polymers.

In one embodiment, the material of the optical film 130 may optionally include diffusion particles (not shown) to increase the haze value of the optical film 130. The diffusion particles can be disposed on the substrate 136, the upper microstructure 132 or the lower microstructure 134, for example. Since the material of the optical film 130 may include diffusing particles, the concealing property of the backlight module 100 is better, thereby improving the assembly yield of the backlight module 100. In other words, the process latitude of the components of the backlight module 100 can also be increased. On the other hand, since the haze value of the optical film 130 is increased, the number of diffusers of the backlight module 100 can be further reduced, which helps to reduce the production cost.

In this embodiment, the substrate 136 includes an upper surface 136S1 and an opposite lower surface 136S2. The upper microstructure 132 is disposed on the upper surface 136S1. The microstructure 134 is disposed on the lower surface 136S2. The lower microstructure 134 of the optical film 130 and the light-emitting surface 120S2 of the light guide plate 120 may be in direct contact, so that the light beam B can be effectively transmitted from the light guide plate 120 to the optical film 130. Therefore, the light energy utilization rate of the backlight module 100 is relatively high.

Please refer to FIGS. 1 and 3A again. In this embodiment, the extension direction of each lower microstructure 134 of the optical film 130 (for example, the Y-axis direction in FIG. 3A) and the extension direction of each upper microstructure 132 There is an angle between the extending directions (for example, the X-axis direction in FIG. 3A). In a preferred embodiment, the extending direction of the lower microstructure 134 and the extending direction of the upper microstructure 132 are perpendicular to each other, but the invention is not limited to this. When the extension direction of the lower microstructure 134 and the extension direction of the upper microstructure 132 are perpendicular to each other, the overall light loss of the backlight module 100 is small, so that the light energy utilization rate is higher. In addition, FIG. 1 illustrates that the extension direction of the lower microstructure 134 of the optical film 130 is perpendicular to the light incident surface 120S1. However, the present invention is not limited to this. In an embodiment, the extension direction of the lower microstructure 134 of the optical film 130 and the light incident surface 120S1 of the light guide plate 120 may not be perpendicular to each other, for example, the lower part of the optical film 130 The included angle between the extending direction of the ridged microstructure 134 and the light incident surface 120S1 of the light guide plate 120 is 90°±10°.

Furthermore, in this embodiment, the upper surface 136S1 of the optical film 130 further includes a flat area F. The flat area F is adjacent to the light incident surface 120S1 of the light guide plate 120, and the flat area F is a flat surface exposing the upper surface 136S1, that is, the flat area F is not provided with the upper ridge microstructure 132 or other microstructures, but the invention does not Limit this. In other embodiments, the flat area F may be provided on the lower surface 136S2 of the optical film 130, and the flat area F is not provided with the lower microstructure 134 or other microstructures. In the backlight module 100 of the embodiment of the present invention, since the optical film 130 may include the flat area F, the light emitting type of the backlight module 100 is at the mura hot spot on the side of the light incident surface 120S1. The problem can be effectively improved.

Please refer to FIG. 3B again. In this embodiment, each of the lower microstructures 134 of the optical film 130 has a cross section perpendicular to the extension direction of the lower microstructure 134 (for example, parallel to the XZ plane in FIG. 3B). Isosceles triangle. The isosceles triangle microstructure 134 can divide a passing light into two light rays in the X-axis direction.

Please refer to FIG. 3C again. In this embodiment, each upper microstructure 132 of the optical film 130 has a light-emitting slope 132S1 and a connecting slope 132S2, and the area of the light-emitting slope 132S1 may be equal to or larger than the area of the connecting slope 132S2. That is, the included angle θ1 between the light emitting slope 132S1 and the upper surface 136S1 may be equal to or less than the included angle θ2 between the connecting slope 132S2 and the upper surface 136S1. For example, in the embodiment of FIG. 3C, with the design in which the area of the light-emitting slope 132S1 of the upper microstructure 132 is larger than the area of the connecting slope 132S2, the light emitted from the light-emitting slope 132S1 can be projected on the YZ plane Presents a specific light type. That is to say, by adjusting the angles θ1 and θ2, the specific light type meets the light emission type required by the backlight module 100, and the light energy utilization rate of the backlight module 100 of the embodiment of the present invention can be further improved. improve.

FIG. 4 is a three-dimensional schematic diagram of the first sheet of the backlight module according to an embodiment of the present invention. Please refer to FIGS. 1 and 4 at the same time. In this embodiment, the first optical film 140 is disposed on one side of the upper surface 136S1 of the optical film 130, and the optical film 130 is disposed on the light guide plate 120 and the first optical film 140 between.

In this embodiment, the first film 140 is, for example, a Brightness Enhancement Film (BEF). The first sheet 140 has a plurality of first microstructures 142, and the extension direction of the first microstructures 142 (for example, the Y-axis direction in FIG. 4) is the same as the upper microstructure 132 of the optical film 130 The extension directions (for example, the X-axis direction in FIG. 3A) are perpendicular to each other.

FIG. 5 is a three-dimensional schematic diagram of a second sheet of the backlight module according to an embodiment of the present invention. Please refer to FIG. 1 and FIG. 5 at the same time. In this embodiment, the first optical film 140 is disposed between the optical film 130 and the second optical film 150.

In this embodiment, the second sheet 150 is, for example, an optical brightness enhancement film. The second sheet 150 has a plurality of second microstructures 152, and the extension direction of the second microstructure 152 (for example, the X-axis direction in FIG. 5) is the same as that of the upper microstructure 132 of the optical film 130 The extension directions are parallel to each other.

In addition, in one embodiment, the backlight module 100 further includes a diffusion sheet 170, wherein the second diffusive sheet 150 is disposed between the diffusing sheet 170 and the first diffusive sheet 140. Since the backlight module 100 is provided with the diffusion sheet 170, and the diffusion sheet 170 further uniformizes the light output of the backlight module 100, the light output pattern of the backlight module 100 is more uniform.

More specifically, referring to FIGS. 1, 3A, 4, and 5, the extension direction of the first microstructure 142 of the first microchip 140 is the Y-axis direction, and the second microstructure of the second microchip 150 The extending direction of the structure 152 is the X-axis direction, and the extending direction of the lower microstructure 134 of the optical film 130 and the extending direction of the upper microstructure 132 are perpendicular to each other, and the first microstructure of the first thin film 140 The extension direction of 142 and the extension direction of the upper microstructure 132 of the optical film 130 are perpendicular to each other, and the extension direction of the second microstructure 152 of the second film 150 and the upper microstructure of the optical film 130 are perpendicular to each other. The extension directions of the 132 are parallel to each other, so the light energy utilization rate of the backlight module 100 of the invention can be improved, but the invention is not limited to this. In other embodiments, the extending direction of the first microstructures 142 of the first thin plate 140 may be the X-axis direction, and the extending direction of the second microstructures 152 of the second thin plate 150 is the Y-axis direction, and The extension direction of the lower microstructure 134 of the optical film 130 and the extension direction of the upper microstructure 132 are perpendicular to each other, and the extension direction of the first microstructure 142 of the first film 140 is the same as that of the upper surface of the optical film 130. The extension directions of the microstructures 132 are parallel to each other, and the extension direction of the second microstructure 152 of the second microstructure 150 and the extension direction of the upper microstructure 132 of the optical film 130 are perpendicular to each other, which can also make the present The light energy utilization rate of the newly created backlight module 100 is improved. In particular, the two extension directions mentioned in the creation of the new model are parallel or perpendicular to each other, and are not limited to being completely parallel or completely perpendicular. The two extension directions can be clamped by 180 according to different requirements (such as solving the moire phenomenon). Degrees ±5 degrees or 90 degrees ±5 degrees can be regarded as mutually parallel or perpendicular to each other.

FIG. 6 is an isochogram of a viewing angle of a preferred embodiment of the backlight module before the light beam is transmitted to the first sheet according to the optical simulation. Due to the reversibility of light, it is desired to design the backlight module 100 to emit light in a positive direction (such as the Z-axis direction in FIG. 1) and uniformly emit light, through reversely tracking with optical simulation software (such as LightTools). The light beam B is transmitted to the light emitting type before the first ridge sheet 140, and the viewing angle isobath diagram as shown in FIG. 6 can be obtained. Please refer to FIG. 6. FIG. 6 shows that the viewing angle isoluminescence diagram has four bright areas, and the four bright areas represent the best area where the light beam B can be converted into brightness. In other words, when the light beam B of the backlight module 100 of the embodiment of the present invention is created from the optical film 130, the light pattern can be similar to the viewing angle isobath diagram of FIG. 6 (that is, the light pattern has four bright areas) , The light energy utilization rate of the backlight module 100 is relatively high.

To sum up, in the backlight module of the embodiment of the invention, since the backlight module is provided with an optical film on one side of the light-emitting surface of the light guide plate, the optical film is provided on the upper surface and the lower surface respectively. The microstructures of the ridge and the microstructures of the bottom ridge, and the extension direction of the microstructures of the bottom ridge and the extension direction of the top ridge microstructure are perpendicular to each other. Therefore, the light beam of the backlight module of the embodiment of the present invention is created from the optical film The light type after the light is emitted can be similar to the better viewing angle isoluminescence map after optical simulation. Compared with the backlight module on the market where a diffuser or an optical brightness enhancement film is arranged on one side of the light-emitting surface of the light guide plate, the backlight module of the embodiment of the present invention has an increase in brightness gain by 1.3 times.

However, the above are only preferred embodiments of the present invention, and should not be used to limit the scope of implementation of the present invention, that is, simple equivalent changes and modifications made in accordance with the scope of the patent application of the present invention and the description of the invention, All are still within the scope of the invention patent. In addition, any embodiment of the present invention or the scope of the patent application does not have to achieve all the objectives or advantages or features disclosed in the present invention. In addition, the abstract part and title are only used to assist in searching for patent documents, and are not used to limit the scope of rights of the present invention. In addition, the terms "first" and "second" mentioned in this specification or the scope of the patent application are only used to name the element (element) or to distinguish different embodiments or ranges, and are not used to limit the number of elements. Upper or lower limit.

100: Backlight module 110: light source 120: light guide plate 120S1: Glossy surface 120S2: Glossy surface 120S3: bottom surface 120S4: side 122: Optical Microstructure 130: optical diaphragm 132: The microstructure of the upper 稜鏡 132S1: light-emitting slope 132S2: Connection slope 134: Microstructure 136: Substrate 136S1, 140S1, 150S1: upper surface 136S2, 140S2, 150S2: bottom surface 140: The First Snapshot 142: The first microstructure 150: The second 稜鏡 piece 152: The second microstructure 160: reflective sheet 170: diffuser B: beam F: Flat zone θ1, θ2: included angle

FIG. 1 is a three-dimensional schematic diagram of a backlight module according to an embodiment of the present invention. 2A and 2B are three-dimensional and cross-sectional schematic diagrams of the light guide plate of the backlight module according to an embodiment of the present invention. 3A to 3C are three-dimensional, front-view and side-view schematic diagrams of the optical film of the backlight module according to an embodiment of the invention, respectively. FIG. 4 is a three-dimensional schematic diagram of the first sheet of the backlight module according to an embodiment of the present invention. FIG. 5 is a three-dimensional schematic diagram of a second sheet of the backlight module according to an embodiment of the present invention. FIG. 6 is an isochogram of a viewing angle of a preferred embodiment of the backlight module before the light beam is transmitted to the first sheet according to the optical simulation.

100: Backlight module

110: light source

120: light guide plate

120S1: Glossy surface

120S2: Glossy surface

122: Optical Microstructure

130: optical diaphragm

132: The microstructure of the upper 稜鏡

134: Microstructure

140: The First Snapshot

142: The first microstructure

150: The second 稜鏡 piece

152: The second microstructure

160: reflective sheet

170: diffuser

F: Flat zone

Claims (10)

A backlight module includes: A light guide plate having a light-incident surface, a light-emitting surface, and a bottom surface, wherein the light-incident surface is connected between the light-emitting surface and the bottom surface, and the light-emitting surface is opposite to the bottom surface; A plurality of light sources are arranged on one side of the light incident surface of the light guide plate and used for emitting a plurality of light beams; An optical film, which is arranged on one side of the light-emitting surface of the light guide plate, includes: A substrate, including an upper surface and an opposite lower surface; A plurality of upper microstructures are arranged on the upper surface; and A plurality of lower microstructures are arranged on the lower surface, wherein the extending direction of each of the lower microstructures and the extending direction of each of the upper microstructures are perpendicular to each other; A first optical film arranged on one side of the upper surface of the optical film, and the optical film is arranged between the light guide plate and the first optical film; and A second optical film, wherein the first optical film is disposed between the optical film and the second optical film. The backlight module according to claim 1, wherein the lower microstructures of the optical film are in direct contact with the light-emitting surface of the light guide plate. The backlight module according to claim 1, wherein the cross section of each of the lower microstructures of the optical film perpendicular to the extension direction of the lower microstructures is an isosceles triangle. The backlight module of claim 1, wherein each of the upper microstructures of the optical film has a light-emitting slope and a connecting slope, and the area of the light-emitting slope is larger than the area of the connecting slope. The backlight module according to claim 4, wherein the angle between the light-emitting slope and the upper surface is smaller than the angle between the connecting slope and the upper surface. The backlight module according to claim 1, wherein the upper surface or the lower surface of the optical film further includes a flat area, the flat area is adjacent to the light incident surface of the light guide plate, and the flat area is not provided with the Some upper and lower microstructures. The backlight module of claim 1, wherein the extension direction of the lower microstructures of the optical film is perpendicular to the light incident surface. The backlight module of claim 1, wherein the first beam has a plurality of first beam microstructures, and the extension direction of the first beam microstructures is consistent with the upper beams of the optical film The extension directions of the microstructures are perpendicular to each other. The backlight module according to claim 8, wherein the second beam has a plurality of second beam microstructures, and the extension direction of the second beam microstructures is consistent with the upper beams of the optical film The extension directions of the microstructures are parallel to each other. The backlight module according to claim 1, wherein the material of the optical film includes diffusion particles.

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