TWI693447B - Light guide film, light guide plate, backlight module and display device - Google Patents

Abstract

A light guide film comprising a substrate and a microstructure layer on the substrate. The substrate has a light incident surface, a light exit surface, and a bottom surface, the bottom surface having a first reflective area adjacent to the light incident surface and a second reflective area outside the first reflective area. The microstructure layer is disposed on the bottom surface and includes a plurality of strip structures and a plurality of dot structures. The strip structures are located at least in the first reflective area, and extends in a direction parallel to the light incident surface, and the dot structures are located in the second reflective area. The invention also provides a light guide plate similar to the light guide film, and a backlight module and a display device including the light guide film or the light guide plate.

Description

Light guide film, light guide plate, backlight module and display device

The invention relates to a light guide element and its application, in particular to a light guide film, light guide plate, backlight module and display device.

The general backlight module mainly includes a light source and a light guide plate, and the light generated by the light source directly enters the light guide plate. However, when the light generated by the light source enters the light guide plate, light of a shorter wavelength (such as blue light) is easily absorbed by the light guide plate. Moreover, as the distance of the light propagating through the light guide plate increases, the shorter wavelength light emitted from the light exit surface of the light guide plate is less, which will cause the light exit surface of the light guide plate to be longer than the part farther away from the light source The light of the wavelength (such as yellow light) exhibits the chromatic aberration phenomenon of the front end and the back end yellow.

Therefore, an object of the present invention is to provide a light guide film that can improve the problem of chromatic aberration.

The light guide film of the present invention includes a substrate and a microstructure layer formed on the substrate. The substrate has a light incident surface, a light exit surface adjacent to the light incident surface, and a bottom surface adjacent to the light incident surface and spaced apart from the light exit surface, the bottom mask has a first reflection area adjacent to the light incident surface, And a second reflective area outside the first reflective area. The microstructure layer is disposed on the bottom surface and includes a plurality of strip-shaped structures and a plurality of dot-shaped structures, wherein the strip-shaped structures are located at least in the first reflection area, and the extension directions of the strip-shaped structures are parallel On the light incident surface, the dot-shaped structure is located in the second reflection area.

Another technical means of the present invention is that a part of the strip structure is provided in the second reflection area.

Another technical means of the present invention is that the distribution area of the strip structure is adjacent to the light incident surface and the area of the distribution area occupies less than 50% of the area of the bottom surface.

Still another technical means of the present invention is that the distribution of the dot-shaped structure near the light incident surface is relatively sparse, and the distribution away from the light incident surface is relatively dense.

Another technical means of the present invention is that the size of the dot-shaped structure adjacent to the light incident surface is small, and the size away from the light incident surface is large.

Another technical means of the present invention is that there is a gap between adjacent strip structures, and the gap increases as the distance between the strip structure and the light incident surface increases.

Another object of the present invention is to provide a backlight module including the aforementioned light guide film and a light source, wherein the light source emits light toward the light incident surface of the substrate.

Another technical means of the present invention is that the backlight module further includes an optical film set disposed on the light guide film.

Another object of the present invention is to provide a display device including the aforementioned backlight module and a display panel disposed on the backlight module.

Another technical means of the present invention is that the display panel has a visible area and a non-visible area, the non-visible area is located at the periphery of the visible area, and the first reflective area of the substrate is located in the projection range of the non-visible area Inside.

Another object of the present invention is to provide a light guide plate that can improve the problem of chromatic aberration.

The light guide plate includes a base material, and a plurality of strip structures and a plurality of dot structures. The substrate has a light incident surface, a light exit surface adjacent to the light incident surface, and a bottom surface adjacent to the light incident surface and spaced apart from the light exit surface, the bottom mask has a first reflection area adjacent to the light incident surface, And a second reflective area outside the first reflective area. The strip-shaped structure and the dot-shaped structure are formed on the bottom surface of the substrate, wherein the strip-shaped structure is located at least in the first reflection area, and the extending direction of the strip-shaped structure is parallel to The light incident surface, and the point-like structure is located in the second reflection area.

Another technical means of the present invention is that a part of the strip structure is provided in an area adjacent to the first reflection area in the second reflection area.

Another technical means of the present invention is that the distribution area of the strip structure is adjacent to the light incident surface and the area of the distribution area occupies less than 50% of the area of the bottom surface.

Another technical means of the present invention is that the distribution of the dot-shaped structures near the light incident surface is relatively sparse, and the distribution away from the light incident surface is relatively dense.

Another technical means of the present invention is that the size of the dot-shaped structure adjacent to the light incident surface is small, and the size away from the light incident surface is large.

Another technical means of the present invention is that there is a gap between adjacent strip structures, and the gap increases as the distance between the strip structure and the light incident surface increases.

Another object of the present invention is to provide a backlight module including the aforementioned light guide plate and a light source, wherein the light source emits light toward the light incident surface of the substrate.

Another technical means of the present invention is that the backlight module further includes an optical film set disposed on the light guide film.

Another object of the present invention is to provide a display device including the aforementioned backlight module and a display panel disposed on the backlight module.

Another technical means of the present invention is that the display panel has a visible area and a non-visible area, the non-visible area is located at the periphery of the visible area, and the first reflective area is located within the projection range of the non-visible area.

The beneficial effect of the present invention is that, through the structural design of the light guide film and the light guide plate, the yellow light with a larger reflection angle is partially emitted first, so as to slow down the blueing phenomenon of the light exit surface adjacent to the light entrance surface, and also reduce The light exiting surface is far away from the yellow light exiting at the light entrance surface, so as to balance and reconcile the overall light exiting color, and solve the problem of color difference generated by the backlight module and the display device.

Relevant patent application features and technical content of the present invention will be clearly presented in the following detailed description of the preferred embodiments with reference to the drawings. Before making a detailed description, it should be noted that similar elements are represented by the same number.

1, it is a preferred embodiment of the backlight module 100 of the present invention, which includes a light guide film 120 and a light source 180. The light source 180 is mainly used to provide light to the light guide film 120, and the light guide film 120 can refract and reflect the light provided by the light source 180, and improve the optical brightness of the backlight module 100, and can make the backlight module The light color of 100 is even.

The light guide film 120 includes a substrate 140 and a microstructure layer 160 formed on the substrate 140. The substrate 140 has a light incident surface 141, a light exit surface 142 adjacent to the light incident surface 141, and a bottom surface 143 adjacent to the light incident surface 141 and spaced apart from the light exit surface 142, the bottom surface 143 has a light adjacent to the entrance surface The first reflecting area 144 of the light surface 141 and a second reflecting area 145 outside the first reflecting area 144. The microstructure layer 160 is disposed on the bottom surface 143 and includes a plurality of strip-shaped structures 161 and a plurality of dot-shaped structures 162. In this embodiment, the strip structure 161 is located in the first reflection area 144, and the extending direction of the strip structure 161 is parallel to the light incident surface 141, and the dot structure 162 is located Within the second reflective area 145. In addition, in the present embodiment, the strip structure 161 and the dot structure 162 are both convex structures, and the strip structure 161 is in a V-cut form.

It should be particularly noted that, in this embodiment, the microstructure layer 160 may be directly coated on the bottom surface 143 of the substrate 140 by UV-cured acrylate resin, and then irradiated with ultraviolet light. The UV glue is formed by curing. That is to say, the microstructure layer 160 can be a coating, and its thickness is extremely thin relative to the substrate 140, so as to meet the design requirements of the thinned backlight module 100.

Referring to FIGS. 2 and 3, in some embodiments, in the dot-shaped structures 162 located in the second reflective area 145, each dot-shaped structure 162 has the same size, and the dot-shaped structures 162 are adjacent The distribution at the light incident surface 141 is relatively sparse, while the distribution at a distance away from the light incident surface 141 is relatively dense. That is to say, the arrangement density of the dot-like structure 162 increases as the distance from the light source 180 increases. In addition, among the strip structures 161 located in the first reflective area 144, there is a gap between the adjacent strip structures 161, and the gap increases with the strip structure 161 and the incident light The distance between the faces 141 increases.

When using one of the traditional light guide films (the entire surface is a V-cut strip structure) instead of using the light guide film 120 of this embodiment, the light generated by the light source enters the substrate at a larger angle The light (such as yellow light) will emit light first, while the light at a smaller angle (such as blue light) continues to propagate through the substrate until it is far away from the light source, causing the front yellow and blue problems on the light emitting surface of the substrate . In the case of using another traditional light guide film (the entire surface is a dot structure) instead of using the light guide film 120 of this embodiment, the light generated by the light source enters the substrate at a smaller angle (for example When the blue light is propagated in the substrate, the more it will be absorbed with the increase of the propagation distance, the problem of front blue and yellow will occur on the light exit surface of the substrate. Therefore, in this embodiment, the micro-structure layer 160 is only a V-cut stripe structure 161 near the light source 180, and the other areas are dot-shaped structures 162, so that the yellow light with a larger reflection angle is partially emitted first. In order to alleviate the blueing phenomenon of the light exit surface 142 adjacent to the light entrance surface 141, the light exit surface 142 of the substrate 140 is improved to show a slight blue color in the area near the light source 180, while also reducing the light exit surface 142 away from the The level of yellow light emitted by the light incident surface 141, and the area away from the light source 180 is slightly yellow, greatly reducing the color difference of the light emitting surface 142, so as to achieve the purpose of balancing and reconciling the light color of the overall backlight module 100, thereby Can solve the problem of color difference. Furthermore, due to the strip structure 161 located in the first reflection area 144, the distance between the strip structure 161 and the light incident surface 141 increases, that is, as it moves away from the On the light incident surface 141, the stripe structure 161 will become thinner and thinner, so that the light emitted from the light incident surface 141 by the stripe structure 161 gradually decreases, to match the material of the substrate 140 to absorb blue light The effect also gradually decreases towards the center to achieve a good uniformity of light color difference.

In some embodiments, the size of each dot structure 162 may increase as the distance between the dot structure 162 and the light source 180 (or the light incident surface 141) increases. In the embodiment shown in FIG. 4, the size of the point structure 162 closer to the light source 180 is smaller, and the size of the point structure 162 further away from the light source 180 is larger. In this way, through the different arrangement of the dot-shaped structure 162, the light output can be more uniform.

Referring to FIG. 5, this is the second preferred embodiment of the backlight module 200 of the present invention. This embodiment is substantially the same as the first preferred embodiment. The only difference is that the strip structures 261 have different arrangement designs. As shown in FIG. 5, in this embodiment, a part of the strip structure 261 is disposed in the second reflective area 245, that is to say, the strip structure 261 is distributed in the first reflective area In the area 244, a strip structure 261 is also provided in the area of the second reflection area 245 adjacent to the first reflection area 244, and at the same time, the distribution area of the strip structure 261 is adjacent to the light incident surface 241 and the distribution area The area is less than 50% of the area of the bottom surface 243. In addition, there is a spacing between the adjacent strip structures 261, and the spacing increases as the distance between the strip structures 261 and the light incident surface 241 increases.

Therefore, in the second reflective area 245, there will be an area where the strip structure 261 and the dot structure 262 are provided at the same time. In this area, the strip structure 261 and the dot structure 262 overlap to form a transition area To make the effect of blue/yellow light compensation smoother. In addition, when the dot-like structure 262 is formed on the strip-like structure 261, the bright lines formed by the strip-like structure 261 can also be blurred and not obvious.

It should be further explained that the light guide film 220 of the present invention adopts a structure with the same thickness or less than that of the light source 280 to meet the design trend of the thinned backlight module 200. If in the technical field of lighting fixtures, it is not as thin as the backlight module 200 requires, the light guide film 220 at this time can use a larger thickness structure, and is made by injection molding and other methods .

Therefore, as shown in FIG. 6, this is the third preferred embodiment of the backlight module 300 of the present invention. The backlight module 300 of this embodiment is substantially the same as the aforementioned backlight module. The difference lies in the backlight module of this embodiment. 300 does not use the aforementioned light guide film, but uses a light guide plate 320. The light guide plate 320 includes a substrate 340 and a plurality of strip-shaped structures 361 and a plurality of dot-shaped structures 362 formed on the substrate 340. Similarly, the substrate 340 has a light incident surface 341, a light exit surface 342 adjacent to the light incident surface 341, and a bottom surface 343 adjacent to the light incident surface 341 and spaced apart from the light exit surface 342, the bottom surface 343 has a The first reflective area 344 adjacent to the light incident surface 341 and a second reflective area 345 outside the first reflective area 344. The strip structure 361 and the dot structure 362 are formed on the bottom surface 343 of the substrate 340, wherein the strip structure 361 is located in the first reflective area 344, and the dot structure 362 is located in the second reflection area 345. In this embodiment, the arrangement and function of the strip structure 361 and the dot structure 362 are the same as the embodiment shown in FIG. 1, and will not be repeated here.

It should be particularly noted that, in this embodiment, the light guide plate 320 is manufactured by a mold by integral injection molding, therefore, the base material 340 and the strip structure 361 and the dot structure 362 are integrally formed As shown in FIG. 1, there is no layered structure between the substrate 140 and the microstructure layer 160.

Referring to FIG. 7, this is the fourth preferred embodiment of the backlight module 400 of the present invention. The backlight module 400 of this embodiment is substantially the same as the aforementioned third preferred embodiment, the only difference is that the strip structure 461 has Different arrangement designs. As shown in FIG. 7, in this embodiment, a part of the strip structure 461 is disposed in the second reflective area 445, that is, the strip structure 461 is distributed in the first reflective area In 444, a strip structure 461 is also provided in the area of the second reflection area 445 adjacent to the first reflection area 444, and at the same time, the distribution area of the strip structure 461 is adjacent to the light incident surface 441 and the distribution area The area is less than 50% of the area of the bottom surface 443. In addition, there is a spacing between the adjacent strip structures 461, and the spacing increases as the distance between the strip structure 461 and the light incident surface 441 increases.

Therefore, in the second reflective area 445, there will be an area where the strip structure 461 and the dot structure 462 are provided at the same time, in which the strip structure 461 and the dot structure 462 are overlapped to form a transition area . In this embodiment, first, a groove corresponding to the strip structure 461 (V-cut form) is made on a mold, and then the groove is laser engraved on the groove A circular groove corresponding to the dot-like structure 462 (dot form) is formed in a manner. Accordingly, the light guide plate 420 formed by injection molding with the mold can form the dot-shaped structure 462 on the strip-shaped structure 461 in the second reflection area 445 at the same time.

Referring to FIG. 8, this is the fifth preferred embodiment of the backlight module 500 of the present invention, which is roughly the same as the first preferred embodiment, except that the preferred embodiment further includes a light guide film 520 disposed on the light guide film 520. Optical diaphragm group 540. Among them, the optical film group 540 can be selected from a diffusion film, a thin film or a brightness enhancement film, so that the backlight module 500 can have a better optical effect. Of course, the light guide film 520 can also be replaced with a light guide plate as shown in FIG. 6 or FIG. 7, which is not limited to the content disclosed in FIG. 8.

9, a preferred embodiment of a display device 600 of the present invention includes a backlight module 500 as shown in FIG. 8, and a display panel 620 disposed in the light-emitting direction of the optical film group 540. After the light generated by the light source 680 enters the light guide film 520, it will emit light through the light guide film 520 and the optical film group 540 and enter the display panel 620, and can achieve the same purpose as described above. In particular, the display panel 620 has a visible area 621 and a non-visible area 622, the non-visible area 622 is located at the periphery of the visible area 621, and the first reflective area 544 is located within the projection range of the non-visible area 622 . With this design, it is possible to prevent the bright lines formed by the strip structure 561 from appearing in the visible area 621 and affect the visual effect presented by the display device 600.

In summary, the present invention provides a strip structure and a dot structure on the bottom surface of the light guide film or the light guide plate, and adjusts the arrangement and density changes of the strip structure and the dot structure to achieve balance The purpose of adjusting the light color of the overall backlight module is to solve the problem of chromatic aberration.

However, the above are only the preferred embodiments of the present invention, which should not be used to limit the scope of the implementation of the present invention, that is, simple equivalent changes and modifications made according to the scope of the patent application of the present invention and the description of the invention, All of them are still covered by the patent of the present invention.

100: backlight module

120: light guide film

140: substrate

141: Light side

142: Light emitting surface

143: Underside

144: first reflection area

145: Second reflection area

160: microstructure layer

161: Strip structure

162: Dotted structure

180: light source

200: backlight module

220: light guide film

241: Light side

243: Underside

244: First reflection area

245: Second reflection area

261: Strip structure

262: Dotted structure

280: light source

300: backlight module

320: light guide plate

340: substrate

341: Light side

342: Light emitting surface

343: Underside

344: First reflection area

345: Second reflection area

361: Strip structure

362: Dotted structure

380: light source

400: backlight module

420: light guide plate

441: Light side

443: Underside

444: First reflection area

445: Second reflection area

461: Strip structure

462: Dotted structure

480: light source

500: backlight module

520: light guide film

544: First reflection zone

545: Second reflection zone

540: Optical diaphragm set

561: Strip structure

562: point structure

580: light source

600: display device

620: display panel

621: Viewing area

622: Invisible area

680: light source

1 is a schematic diagram of a first preferred embodiment of the backlight module of the present invention; FIG. 2 is a schematic diagram to help explain FIG. 1 from another angle; FIG. 3 is a graph illustrating the percentage of the distance between the position of the strip structure and the point structure on the light guide film relative to the light incident surface of the total length of the light guide plate and the structure density; 4 is a schematic diagram of a second preferred embodiment of the backlight module of the present invention; FIG. 5 is a schematic diagram showing different aspects of the dot-shaped structure in the second preferred embodiment; 6 is a schematic diagram of a third preferred embodiment of the backlight module of the present invention; 7 is a schematic diagram of a fourth preferred embodiment of the backlight module of the present invention; 8 is a schematic diagram of a fifth preferred embodiment of the backlight module of the present invention; and 9 is a schematic diagram of a preferred embodiment of the display device of the present invention.

100: backlight module

120: light guide film

140: substrate

141: Light side

142: Light emitting surface

143: Underside

144: first reflection area

145: Second reflection area

160: microstructure layer

161: Strip structure

162: Dotted structure

180: light source

Claims (20)

A light guide film includes: a substrate having a light incident surface, a light exit surface adjacent to the light incident surface, and a bottom surface adjacent to the light incident surface and spaced apart from the light exit surface, the bottom mask has a A first reflecting area adjacent to the light incident surface, and a second reflecting area other than the first reflecting area; and a microstructure layer disposed on the bottom surface of the substrate and including a plurality of strip-like structures and a plurality of points Structure, wherein the strip structure is located at least in the first reflection area, and the extending direction of the strip structure is parallel to the light incident surface, and the dot structure is located in the second reflection area Inside, and there is a layered structure between the substrate and the microstructure layer. According to the light guide film described in item 1 of the patent application scope, a part of the strip structure is provided in an area adjacent to the first reflection area in the second reflection area. According to the light guide film described in item 1 of the patent application range, wherein the distribution area of the stripe structure is adjacent to the light incident surface and the area of the distribution area is less than 50% of the area of the bottom surface. The light guide film according to item 1 of the scope of the patent application, wherein the distribution of the dot-like structures is close to the light incident surface, and is densely distributed away from the light incident surface. According to the light guide film described in item 1 of the patent application range, the size of the dot-shaped structure adjacent to the light incident surface is small, and the size away from the light incident surface is large. The light guide film according to any one of items 1 to 5 of the patent application range, wherein the adjacent strip-shaped structures have a gap between them, and the gap follows the strip-shaped structures The distance from the light incident surface increases and increases. A backlight module includes a light guide film as described in any one of claims 1 to 6 and a light source, wherein the light source emits light toward the light incident surface of the substrate. The backlight module according to item 7 of the patent application scope further includes an optical film set disposed on the light guide film. A display device includes a backlight module as described in item 7 or 8 of the patent application, and a display panel provided on the backlight module. The display device according to item 9 of the patent application scope, wherein the display panel has a visible area and a non-visible area, the non-visible area is located at the periphery of the visible area, and the first reflective area of the substrate is located at the non-visible area Within the projection area of the viewable area. A light guide plate includes: a base material having a light incident surface, a light exit surface adjacent to the light incident surface, and a bottom surface adjacent to the light incident surface and spaced apart from the light exit surface, the bottom mask has a surface adjacent to the light incident surface A first reflecting area on the surface, and a second reflecting area other than the first reflecting area; and a plurality of strip structures and a plurality of dot structures are formed on the bottom surface of the substrate, wherein the strip structure Is located at least in the first reflective area, and the extending direction of the strip structure is parallel to the light incident surface, and the dotted structure is located in the second reflective area, and the substrate and the strip The shaped structure is integrally formed with the dot-shaped structure. According to the light guide plate described in item 11 of the patent application scope, part of the The shape-like structure is provided in an area adjacent to the first reflection area in the second reflection area. According to the light guide plate described in item 11 of the patent application range, wherein the distribution area of the strip structure is adjacent to the light incident surface and the area of the distribution area is less than 50% of the area of the bottom surface. The light guide plate according to item 11 of the patent application scope, wherein the distribution of the dot-shaped structures near the light incident surface is relatively sparse, and the distribution away from the light incident surface is relatively dense. The light guide plate according to item 11 of the patent application scope, wherein the size of the dot-shaped structure adjacent to the light incident surface is smaller, and the size away from the light incident surface is larger. The light guide plate according to any one of items 11 to 15 of the patent application range, wherein the adjacent strip-shaped structures have a gap between them, and the gap increases with the strip-shaped structure and the incident light The distance between the faces increases. A backlight module includes a light guide plate as described in any one of claims 11 to 16, and a light source, wherein the light source emits light toward the light incident surface of the substrate. The backlight module according to item 17 of the patent application scope further includes an optical film set disposed on the light guide plate. A display device includes a backlight module as described in item 17 or 18 of the patent application, and a display panel provided on the backlight module. The display device according to item 19 of the patent application scope, wherein the display panel has a visible area and a non-visible area, the non-visible area is located at the periphery of the visible area, and the first reflective area is a projection located at the non-visible area Within range.

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