TW201816439A - Light guide plate, processing method and backlight module for eliminating hot spot phenomenon - Google Patents

Abstract

A light guide plate, processing method and backlight module for eliminating hot spot phenomenon is disclosed. The light guide plate includes a lighting exiting surface, a bottom surface and a light incident surface. The light guide plate receives the light from a light bar, and an optical isolation structure is cover on a side of the light guide plate and the light bar. A plurality of light microstructures is formed on the light incident surface of the light guide plate. The light microstructure is formed by a laser moving from the light exiting surface to the bottom surface, so that the width and the depth of each light microstructure are decreasing form the lighting exiting surface to the bottom surface. When the light guide plate receives light, the light microstructure causes light exiting early from the optical isolation structure; and therefore hot spots phenomenon can be eliminated. In addition, laser processing method can be used to manufacture large size light guide plate, so that the shortcoming of manufacture the microstructure of the light incident surface can be resolved.

Description

   Light guide plate capable of eliminating hot spots, processing method and backlight module   

The invention relates to the field of light guide plates, in particular to a light guide plate capable of eliminating hot spots, a processing method and a backlight module thereof.

The light guide plate has excellent optical characteristics. In addition to being used alone as a light supply product with a light source, it is also commonly used in a backlight module of a display device as an element that guides a point light source to form a uniform surface light source. At present, light-emitting diodes (LEDs) are mostly used as the light source of the light guide plate. Generally, a plurality of LEDs arranged at equal intervals are arranged on the light entrance side of one of the light guide plates to form a side-entry light relative to the light guide plate. The light exit surface forms a uniform light exit.

However, due to the limited light spread angle of the LEDs, bright and dark distribution blocks are formed near the light input side of the light guide plate, which is a hot spot phenomenon, which may be caused by the insufficient spread angle of each LED Or, the light and dark unevenness caused by the light entering the light guide plate from the light entrance side directly or through reflection to form a partially over-bright area on the light exit surface. Then, in order to solve the hot spot phenomenon, manufacturers set up optical structures on the surface of the light incident side, so that the light is affected by these optical structures to adjust the angle when they enter the light incident side, so as to solve the aforementioned hot spot phenomenon of uneven brightness.

Most of these optical structures are formed when the light guide plate is injection molded, that is, directly formed on the light incident side surface, or after the light guide plate is injection molded and then cut and formed by a cutter. However, tool cutting has its limits. When the optical structure design is more complicated, it is easy to produce a broken tool during cutting, so the tool cutting process scheme is not applicable. In view of the design of complex optical structures, most manufacturers usually use injection molding process to design a complex optical structure formed as a mirror surface on the light entrance side of the light guide plate through the mold core, but injection molding cannot be used to make large-size guides. Light board.

In addition, the current light guide plate of the optical structure of the light entrance mask can not effectively solve the phenomenon that part of the light directly or through reflection forms the bright area of the visible surface of the light emitting surface, so that in the actual application of the light guide plate, the user can still see many bright and dark The area affects the light uniformity of the light guide plate.

Therefore, in order to reduce the difficulty of manufacturing the optical structure of the light guide plate on the light incident side surface, and to effectively solve the hot spot phenomenon of uneven brightness in response to the requirements of the light guide plates of various sizes, the inventor has devised a method to eliminate the hot spot phenomenon The light guide plate, the processing method and the backlight module thereof can effectively improve the aforementioned defects.

An object of the present invention is to provide a light guide plate capable of eliminating hot spots, a processing method and a backlight module thereof. The light path and the spread angle are adjusted through the light spreading microstructure on the light entrance surface, thereby eliminating the hot spot phenomenon, and The molten surface formed by laser processing can be applied to achieve a better spread angle effect.

In order to achieve the above object, the present invention discloses in one embodiment a processing method of a light guide plate capable of eliminating hot spots, including the following steps: providing at least one light guide plate, the light guide plate having a light emitting surface, a bottom surface and a light incident surface , The light exit surface is disposed opposite to the bottom surface, the light entrance surface is adjacent to the light exit surface and the bottom surface; the light entrance surface is processed with a laser beam, and the laser beam moves from the light exit surface toward the bottom surface, and The light incident surface forms a light spreading microstructure, and the width and depth of the light spreading microstructure decrease from the light emitting surface toward the bottom surface respectively; and the laser beam is repeatedly irradiated to the light incident surface with the laser beam under the aforementioned conditions until The light-incident surface forms a plurality of light-expanding microstructures. In this way, through the light-expanding microstructure that is inclined with respect to the bottom surface and has a wide and narrow width, the reflection path of the light from the light entrance surface to the light guide plate can be effectively adjusted to make it closer to the light exit surface closer to the light entrance surface Light is formed in the area to avoid affecting the light uniformity of the visible range when the light guide plate is applied.

In another embodiment, when the light guide plates are provided in plural, the light incident surfaces of the light guide plates are aligned with each other to form a processing plane, and then the laser beam is irradiated to the processing plane. The light-expanding microstructures are formed on the light-incident surfaces respectively, so that the process speed can be effectively increased while maintaining the product yield, and the effect of mass production can be achieved.

In addition, in still another embodiment, each of the light-expanding microstructures and the light-emitting surface are adjacent to the midpoint of the side surface and each of the light-spreading microstructures and the bottom surface are adjacent to the midpoint of the side surface, and the light-emitting surface method The angle of the line is less than or equal to 1 °, to prevent the microstructure of the spreading light from being too inclined and affecting the light adjustment effect.

In one embodiment of the present invention, a light guide plate capable of eliminating hot spots is also disclosed, which is used to receive light from a light bar, and a light shield can be placed on the side of the light bar and the light guide plate capable of eliminating hot spots. , Which includes: a light-emitting surface; a bottom surface, which is disposed opposite to the light-emitting surface; a light-incident surface, adjacent to the light-emitting surface and the bottom surface, for receiving light from the light bar; and a plurality of light-expanding microstructures formed on the The light incident surface, the width and depth of each of the light-expanding microstructures decrease from the light-emitting surface toward the bottom surface, whereby the light of the light bar enters the light-incident surface and is affected by the light-expanding microstructures at the same time, so that the light The light is emitted early in the action range of the shading member to eliminate the hot spot phenomenon formed by the light directly emitted from the light emitting surface. As described above, through the light-expanding microstructure that is inclined with respect to the bottom surface and has a wide and narrow width, the light path can be adjusted to emit light within the range of action of the shading member to prevent affecting the light uniformity in the visible area of the light guide plate.

Preferably, based on the foregoing embodiment, in another embodiment, each of the light-expanding microstructures is a concave structure with a molten surface formed by laser processing, so as to adjust the light entrance angle of the light by the molten irregular surface, and Use laser processing to achieve rapid mass production.

In yet another embodiment, each of the light-expanding microstructures and the light-emitting surface are adjacent to the midpoint of the side and each of the light-spreading microstructures and the bottom surface are adjacent to the midpoint of the side and are connected to the normal of the light-emitting surface The angle is less than or equal to 1 ° to prevent the microstructure of the spreading light from being too tilted and affecting the light adjustment effect.

In one embodiment of the present invention, a backlight module capable of eliminating hot spots includes a light bar; a light guide plate corresponding to one side of the light bar, and the light guide plate has: a light exit surface; a bottom surface , Arranged relative to the light exit surface; a light incident surface adjacent to the light exit surface and the bottom surface for receiving light from the light bar; and a plurality of light spreading microstructures formed on the light incident surface, each of the light spreading microstructures The width and depth of the light-reducing surface gradually decrease toward the bottom surface; and a light-shielding member corresponding to the light-emitting mask is provided on the side of the light bar and the light guide plate; thereby, the light provided by the light bar enters the incident light While being affected by the light-spreading microstructures, due to the wide and narrow changes of the light-spreading microstructures, the light is emitted in the range of action of the shading element early to avoid uneven brightness and darkness on the light-emitting surface, which affects the actual The overall light uniformity of the light guide plate during use.

In still another embodiment, each of the light-expanding microstructures is a concave structure with a molten surface formed by laser processing, so that the irregular surface of the melt can effectively increase the angle of light entering the light, and the laser processing can achieve rapid The purpose of mass production.

In the next embodiment, each of the light-gathering microstructures and the light-emitting surface are adjacent to the midpoint of the side surface and each of the light-gathering microstructures and the bottom surface are adjacent to the midpoint of the side surface, and the normal to the light-emitting surface is at an angle Less than or equal to 1 °, to prevent the angle is too large but affect the light adjustment effect.

In summary, the light guide plate, the processing method and the backlight module of the present invention that can eliminate hot spots can effectively adjust the light incident from the light incident surface through the light spreading microstructure with a width change and an inclination relative to the bottom surface Diameter, which effectively solves the hot spot phenomenon of uneven brightness and provides better light quality. And laser processing is used to make the exposed light microstructure have a molten surface. In addition to allowing various sizes, especially large-size light guide plates to achieve rapid mass production, it can also use the molten surface to diffuse light to increase the incident spread angle.

1‧‧‧Light guide plate

10‧‧‧Glossy

11‧‧‧Bottom

12‧‧‧Into the light

13‧‧‧Zhanguang Microstructure

2‧‧‧Light bar

3‧‧‧Shading

A‧‧‧Machining plane

L‧‧‧Laser beam

P ₁ ‧‧‧Expanded light microstructure and light emitting surface are adjacent to the midpoint of the side

P ₂ ‧‧‧ The light microstructure and the bottom surface are adjacent to the midpoint of the side

N‧‧‧Normal

θ‧‧‧ included angle

S01 ~ S03‧‧‧Step

Figure 1 is a flow chart of the steps of the preferred embodiment of the present invention.

Figure 2 is a schematic view of the processing of the preferred embodiment of the present invention (1).

Figure 3 is a schematic diagram of processing (2) of the preferred embodiment of the present invention.

Figure 4 is a schematic diagram of a light guide plate according to a preferred embodiment of the present invention.

Fig. 5 is a cross-sectional view of a light guide plate according to a preferred embodiment of the present invention.

FIG. 6 is a schematic diagram of the application of the light guide plate combining the light bar and the shading member in the preferred embodiment of the present invention.

As mentioned above, in view of the lack of manufacturing processes for the light-incident surface optical structure in the past and the increasing demand for large-size light guide plates, in order to effectively alleviate the hot spot phenomenon of large-size light guide plates, it also has the advantages of rapid production and high yield. The inventor then proposed the following. Please refer to Figures 1, 2, 3, 4, 5 and 6, which are the flowchart of the steps of the preferred embodiment of the present invention, the processing schematic diagram (1), the processing schematic diagram (2), the light guide plate schematic diagram, the light guide plate sectional view A schematic diagram of the application of the light guide plate combining the light bar and the shading member. The invention discloses a processing method of a light guide plate capable of eliminating hot spots, and the steps are as follows. First, at least one light guide plate 1 is provided. The light guide plate 1 has a light exit surface 10, a bottom surface 11 and a light incident surface 12, the light exit surface 10 is disposed opposite to the bottom surface 11, and the light incident surface 12 is adjacent to the light exit surface 10 and the bottom surface 11 (Step S01). Next, a laser beam L is processed into the light surface 12, and the laser beam L is moved from the light exit surface 10 toward the bottom surface 11, and a light spreading microstructure 13 is formed on the light entrance surface 12, whose width and depth are respectively The light exit surface 10 gradually decreases toward the bottom surface 11 (step S02). When the light-expanding microstructure 13 is processed by the laser beam L to form a concave structure with a molten surface, compared with the mirror structure, the irregular surface passing through the melt allows the light to pass through the diffusion phenomenon and increase the angle of light spreading. Finally, the light incident surface 12 is repeatedly irradiated with the laser beam L under the foregoing conditions until a plurality of light spreading microstructures 13 are formed on the light incident surface 12 (step S03). In this way, the light guide plate 1 transmits the light spreading microstructure 13 whose width and depth decrease from the light exit surface 10 toward the bottom surface 11 respectively, which can change the reflection path of part of light entering the light guide plate 1 after entering the light entrance surface 12 to make it emit light The area is closer to the light incident surface 12 side, so as to effectively eliminate the hot spot phenomenon that the light directly exits the light exit surface 10 or is reflected by the light exiting the light exit surface 12 area.

Among them, when the light guide plates 1 are provided in plural, the light incident surfaces 12 of the light guide plates 1 are aligned with each other to form a processing plane A, and then the laser light is directed from the light exit surface 10 toward the bottom surface 11 in the moving direction The light beam L irradiates the processing plane A, and forms a light spreading microstructure 13 on each light incident surface 12, as shown in FIG. 3, thereby effectively increasing the yield and processing of the light guide plate 1 while maintaining a certain product yield speed.

The structure of the light guide plate 1 after molding is shown in Figs. 4 and 5, since the width and depth of each light-expanding microstructure 13 are gradually reduced from the light-emitting surface 10 toward the bottom surface 11, the light-expanding microstructure is viewed in cross section The 13 series is in an inclined state with respect to the bottom surface 11. Through this inclined structure state, the light can be emitted early in the area adjacent to the light incident surface 12 according to the reflection theorem. Preferably, each of the spreading microstructures 13 and the light emitting surface 10 adjoin the middle point P _{1 of the} side and each of the spreading microstructures 13 and the bottom surface 11 adjoin the middle point P _{2 of the} side, and a normal line of the light emitting surface 10 The angle θ of N is less than or equal to 1 °, to avoid the light entering the light-expanding microstructure 13, because the inclined angle is too large to allow the light to enter the light guide plate 1, the light is formed away from the light incident surface 12 area, and to ensure effective control In the case of light reflection angle, it does not affect the overall light uniformity.

In application, a light bar 2 can be correspondingly arranged on the light incident surface 12 of the light guide plate 1. Preferably, the light bar 2 is provided with a plurality of light sources 20, and a light shield can be covered between the light bar 2 and the light guide plate 1 3. The light emitting surface 10 of the light guide plate 1 can be partially shielded by the shading member 3, as shown in FIG. 6. In detail, the light blocking member 3 is disposed corresponding to the side of the light incident surface 12 of the light guide plate 1 and extends to cover the area of the light exit surface 10 adjacent to the light incident surface 12. As mentioned above, the hot spot phenomenon formed on the light guide plate 1 can be generally divided into two cases. One is viewed from the angle of view of the light emitting surface 10, which is affected by the spacing of the light source 20 on the light bar 2 and the light spreading angle. The light and dark areas are formed alternately, and the other is the light leakage in the vertical direction, that is, the bright area formed by the light from the light source 20 of the light bar 2 entering the light guide plate 1 from the light entrance surface 12 and directly exiting the light exit surface 10, or The light irradiates the bottom surface 11 and forms a bright area according to the reflection on the light exit surface 10. By changing the width of the light-expanding microstructure 13 and its tilted state, the light after entering the light guide plate 1 from the light incident surface 12 can shorten the overall reflection path according to the reflection theorem and emit light earlier, so that the light approaches the light incident surface 12 The area emits light, so that the light output area falls within the action range of the light shielding member 3 relative to the light emitting surface 10, and is shielded by the light shielding member 3 to eliminate the occurrence of bright areas. Among them, the figures shown in the figures are only a simple schematic, not the actual component structure size.

Please refer to Figures 4, 5, and 6 again. The present invention also discloses a backlight module that can eliminate hot spots, including a light bar 2, a light guide plate 1, and a light blocking member 3. As shown in FIG. 6, the light guide plate 1 is correspondingly disposed on the side of the light bar 2 and has a light emitting surface 10, a bottom surface 11, a light incident surface 12 and a plurality of light spreading microstructures 13. The light-emitting surface 10 is opposite to the bottom surface 11, the light-incident surface 12 is adjacent to the light-emitting surface 10 and the bottom surface 11, respectively, to receive the light from the light bar 2, the light-expanding microstructure 13 is formed on the light-incident surface 12, and each light-expanding microstructure The width and depth of 13 gradually decrease from the light emitting surface 10 toward the bottom surface 11, and the light shielding member 3 is provided on the side of the light bar 2 and the light guide plate 1 corresponding to the light emitting surface 10. In this way, when the light provided by the light bar 1 enters the light entrance surface 12 and is affected by the spreading microstructure 13, at the same time, in response to the width of the spreading microstructure 13, the light can be emitted earlier in the range of action of the shading member 3, thereby eliminating The hot spot phenomenon formed by the light exiting directly from the light exit surface 10 or the light exiting the non-shielding member 3 shielding area. As shown in FIG. 4, preferably, each of the spreading microstructures 13 is a concave structure with a molten surface formed by laser processing, so as to effectively adjust the light path of the light through the diffusion phenomenon. The remaining detailed technical features have been described above And will not be repeated here.

Similarly, as shown in FIGS. 4 and 5, in order to make the light guide plate 1 have excellent dimming performance while maintaining the overall light uniformity, each of the light spreading microstructures 13 formed on the light incident surface 12 is The light emitting surface 10 adjoins the middle point P _{1 of the} side and the bottom surface 11 adjoins the middle point P _{2 of the} side, and the angle N of the normal line N of the light emitting surface 10 is less than or equal to 1 ° to prevent the influence of the excessive tilt angle For the light adjustment performance, the remaining detailed technical features have been described above and will not be repeated here.

In summary, the light guide plate, the processing method and the backlight module disclosed in the present invention that can eliminate the hot spot phenomenon can effectively increase the entrance of the light bar light source relative to the light guide plate by forming the light spreading microstructure formed in the width of the light entrance mask. Outside the light spreading angle, at the same time, by tilting the light spreading microstructure, part of the light is shortened in response to the reflection theorem to form light in the light exit surface area adjacent to the light entrance surface, which can be shielded by the shading member during application to eliminate the guide Hot spot phenomenon when using light board. The light spreading microstructures are made by laser processing, and are concave structures with a molten surface, which has a better light spreading effect than a mirror surface. In terms of manufacturing, the laser processing system can meet the processing requirements of large-size light guide plates, and in addition to being faster, it can also maintain a certain product yield.

However, the above are only preferred embodiments of the present invention and are not intended to limit the scope of the present invention; therefore, all changes and modifications made without departing from the spirit and scope of the present invention should be covered in Within the patent scope of the invention.

Claims (9)

    A processing method of a light guide plate capable of eliminating hot spots includes the following steps: providing at least one light guide plate, the light guide plate having a light exit surface, a bottom surface and a light incident surface, the light exit surface being disposed opposite to the bottom surface, the light incident surface Adjacent to the light-emitting surface and the bottom surface; the light-incident surface is processed with a laser beam, and the laser beam moves from the light-emitting surface toward the bottom surface, and a light-expanding microstructure is formed on the light-incident surface. The width and depth of the light microstructure are gradually reduced from the light emitting surface toward the bottom surface; and the laser beam is repeatedly irradiated to the light incident surface with the aforementioned conditions until a plurality of light spreading microstructures are formed on the light incident surface.         The processing method of a light guide plate capable of eliminating hot spots as described in item 1 of the patent application scope, wherein, when the light guide plates are provided in plural, the light incident surfaces of the light guide plates are aligned with each other in a stacked manner A processing plane is formed, and then the processing plane is irradiated with the laser beam to form the light spreading microstructure on each of the light incident surfaces respectively.         The processing method of the light guide plate capable of eliminating the hot spot phenomenon as described in item 1 of the patent application scope, wherein each of the spreading microstructures is adjacent to the midpoint of the side of the light exit surface and each of the spreading microstructures is adjacent to the bottom surface The angle between the midpoint of the side and the normal to the light exit surface is less than or equal to 1 °.         A light guide plate capable of eliminating hot spot phenomenon for receiving light from a light bar, and a light shielding member can be placed on the side of the light bar and the light guide plate capable of eliminating hot spot phenomenon, which includes: a light emitting surface; The bottom surface is arranged opposite to the light-emitting surface; a light-incident surface is adjacent to the light-emitting surface and the bottom surface to receive light from the light bar; and a plurality of light-expanding microstructures are formed on the light-incident surface, each of the light-expanding The width and depth of the structure gradually decrease from the light-emitting surface toward the bottom surface, whereby the light of the light bar enters the light-incident surface and is affected by the light-expanding microstructures at the same time, so that the light emits light earlier in the scope of action of the shading member In order to eliminate the hot spot phenomenon formed by the light directly from the light exit surface.         The light guide plate capable of eliminating the hot spot phenomenon as described in item 4 of the patent application scope, wherein each of the light-expanding microstructures is a concave structure with a molten surface formed by laser processing.         The light guide plate capable of eliminating the hot spot phenomenon as described in item 4 of the patent application scope, wherein each of the midpoints of the side edges of the light-expanding microstructure and the light exit surface and the side edges of the light-expanding microstructure and the bottom surface The angle between the midpoint connection and the normal to the light exit surface is less than or equal to 1 °.         A backlight module capable of eliminating hot spots includes: a light bar; a light guide plate corresponding to one side of the light bar; and the light guide plate has: a light exit surface; a bottom surface, which is opposite to the light exit surface; The light surface is adjacent to the light-emitting surface and the bottom surface for receiving light from the light bar; and a plurality of light-expanding microstructures are formed on the light-incident surface, and the width and depth of each light-expanding microstructure are respectively determined by the light-emitting surface Decrease towards the bottom surface; and a light-shielding member, corresponding to the light emitting mask is provided on the side of the light bar and the light guide plate; thereby, the light provided by the light bar enters the light incident surface and is affected by the light At the same time when the structure acts, due to the wide and narrow changes of the light spreading microstructures, light emerges earlier in the range of action of the shading member.         The backlight module capable of eliminating hot spots as described in item 7 of the patent application scope, wherein each of the spreading microstructures is a concave structure with a molten surface formed by laser processing.         The backlight module capable of eliminating the hot spot phenomenon as described in item 7 of the patent application scope, wherein each of the spreading microstructures and the light exit surface are adjacent to the midpoint of the side and each of the spreading microstructures and the bottom surface are adjacent to the side The angle between the midpoint line and the normal to the light exit surface is less than or equal to 1 °.