TWI590211B - Narrow frame display device of the light guide plate - Google Patents

Description

Light guide plate for narrow bezel display device

The invention relates to the field of light guide plates, in particular to a light guide plate of a narrow frame display device which can effectively solve hot spots.

In various display devices, in order to make the light of the light source effectively guided to form a uniform light, a light guide plate is used together with a light emitting diode (hereinafter referred to as LED) as a backlight module to achieve the purpose. According to the arrangement of the light source relative to the light guide plate, the backlight module can be divided into two types: a direct type and a side type. As shown in FIG. 1 , the conventional side-lit backlight module 1 includes a light guide plate 10 and a plurality of LEDs 11 , and the LEDs 11 are spaced apart from the light incident surface 101 on the side of the light guide plate 10 to allow light to enter the light. The light guide plate 10 uniformly emits light. However, since the LED 11 has a limited light-expanding angle instead of a planar light source that emits light at 180 degrees, the light guide plate 10 forms a bright area S ₁ in a region close to the LED 11 and falling within the range of the light-expanding angle, in the range of the light-expanding angle. a dark region outside the region will S _2, the plurality of light areas and dark areas S ₁ S ₂ causes uneven light guide plate 10, i.e. a so-called hot spots (hot Spot) phenomenon. In addition, in recent years, LED11 has higher and higher luminous power with the development of technology, so the number of LEDs 11 disposed on the light-incident surface 101 can be reduced, but reducing the number of LEDs 11 relatively increases the interval between adjacent LEDs 11, but instead It will increase the area of the dark area S ₂ , making the hot spot phenomenon more serious.

In order to improve the hot spot phenomenon, the relevant industry has proposed the backlight module such as the Republic of China Patent No. I372919, the light guide plate of the Republic of China Patent No. I457620 and its backlight module, and the side light type of the Republic of China Patent No. M324222. Backlight module and Republic of China The technical content of the diffusion sheet and the backlight module of Patent Publication No. 201430452. These techniques add other structures such as beveled bumps or inclined light guides and wedge-shaped light guides on the light guide plate to adjust the traveling path of the light to solve the problem of bright and dark areas. Or a convex mirror is added to the light-incident surface of the light guide plate, so that the light is refracted by the convex mirror to reach various parts of the light guide plate to effectively improve the hot spot phenomenon and uniformity. Or by adding a diffusion sheet to the backlight module to cooperate with the light guide plate, the atomization enhancement region on the diffusion sheet is disposed along the light incident surface of the light guide plate to eliminate bright spots at the light entrance of the light guide plate. However, the technique of adding structures or components has caused a lot of inconveniences in the process, such as increasing process cost and process difficulty and complexity, and the product yield is not easy to control.

Therefore, it is derived from the backlight module of the Republic of China Certificate No. I432804, or the structure improvement of the light guide plate of the Republic of China Certificate No. M331675 and the light guide plate structure with laser engraving as in the Republic of China Certificate No. M409450. . These technologies belong to the light guide plate to set the microstructure to change the direction of light travel to improve the hot spot phenomenon. For example, a discontinuous microstructure region is disposed on the light incident surface of the light guide plate, so that the microstructure region and the light source are staggered to change the traveling direction of the light, thereby improving the hot spot phenomenon. Or a groove and a mesh point are arranged on the light emitting surface and/or the bottom surface of the light guide plate, so that light is reflected and scattered through the groove and the mesh point to improve the uniformity of light brightness. Or an inner engraving structure is arranged adjacent to the light-incident surface of the light guide plate body, so that when the light enters the light guide plate, the inner engraving structure can destroy the traveling route, thereby generating the effect of mixing light and optical diffusion, so that the phenomenon of light and dark is no longer existed. . And, the microstructure is disposed on the light incident surface, and the plurality of first light sources are disposed corresponding to the region where the light incident surface has no microstructure, and the plurality of second light sources corresponding to the light incident surface have a microstructured region, and the adjacent two The pitch of a light source avoids the problem that the light guide plate produces a local bright and dark area corresponding to the area of the first light source. In addition, the microstructure can increase the degree of divergence of the light beam from the second light source after entering the light guide plate, thereby helping to enhance the light beam of the second light source to enter the light guide plate. The degree of divergence allows the beam to be transmitted to the edge of the exit area, effectively improving the problem of dark areas in the edge. However, setting the microstructure on the light-incident surface can improve the problem of bright and dark areas, but it will cause loss of incident light, resulting in a decrease in optical coupling efficiency. When micro-structures are provided on the light-emitting surface and/or the bottom surface, only the guide can be lifted. The uniformity of light emission in most areas of the light plate can not effectively eliminate the hot spot phenomenon formed by the interval of the light source in the light exiting area of the adjacent light source; the inner carving structure is far more difficult in the process than the microstructure processing on the surface of the light guide plate. And the process methods that can be used are also limited, which is not easy to mass produce and has a problem of poor yield. Although there is a light source module such as the Republic of China Certificate No. M499575, it is proposed to set the microstructure on the light-incident surface but to improve the optical coupling efficiency by using different light sources to avoid the loss of incident light, but this method needs to be directed to the light source characteristics. Designed with micro-structured surfaces to increase design difficulty, and the use of multiple light sources also increases material costs.

An object of the present invention is to provide a light guide plate for a narrow bezel display device, which can effectively solve the hot spot phenomenon on the light incident side of the adjacent light guide plate, so as to reduce the requirement of the frame width and the number of light sources for the assembled assembly.

In order to achieve the above object, the present invention is directed to a light guide plate of a narrow bezel display device, which forms a light incident side corresponding to a plurality of light sources, and includes: a plurality of reserved regions corresponding to the light sources from the light incident side, formed in the light source a surface of the light guide plate; a plurality of light guiding microstructures disposed on the surface of each of the reserved regions, arranged radially, and further forming a light-expanding region with the reserved region; and a plurality of light-blocking microstructures disposed on the surface The adjacent light-extracting sections on the surface are radially arranged from the light-incident side edges to intercept light and form light. Through the setting of the reserved area, the energy loss after the light source is incident on the light guide plate can be reduced, and the light guide microstructure is used to expand the light. The light-expanding angle increases the overlapping area of the light in the adjacent light-extracting region, and part of the light travels to the light-blocking microstructure to be guided to form light at the place, thereby reducing the corresponding phase of the light guide plate The dark area between the adjacent light sources enhances the light uniformity of the light-input side of the light guide plate, solves the hot spot phenomenon and reduces the width of the border of the subsequent matching application, and improves the spacing of the light source to reduce the installation cost.

In one embodiment, the light guiding microstructures are a trench, such as a V-shaped trench or a U-shaped trench; or in another embodiment, each of the light guiding microstructures may be arranged by a plurality of dot-shaped recesses. A linear like state is formed, and the punctiform groove may be an elliptical groove or a meandering groove. Through the light guiding microstructure to change the light travel path, effectively enhance the light angle of the light, and adjust according to the process, the type of light source or the required optical requirements.

In order to obtain better blocking and guiding light illuminating efficiency, in another embodiment, the guiding microstructure of the light-expanding region and the adjacent long-axis direction of the light-blocking microstructure are 85 degrees. 95 degrees.

In the embodiment, the light-blocking microstructures are a trench, such as a V-shaped trench, in accordance with the light guide plate process, the type of light source to be matched, or the required optical requirements. Or a U-shaped trench; or in another embodiment, each of the light-blocking microstructures is formed by a plurality of dot-like grooves to form a linear-like state, and the dot-shaped groove may be an elliptical groove or a meandering groove .

Therefore, the light guide plate of the narrow bezel display device disclosed in the present invention can utilize the reserved area disposed on the surface of the light guide plate, the light guiding microstructure and the light blocking microstructure to effectively reduce the unevenness of light emission, and the light guiding microscopic The structure enhances the light-expanding angle of the light incident on the light guide plate, and simultaneously guides part of the light from the light-guide plate to the dark area formed by the adjacent light source through the light-blocking microstructure, so that the light guide plate has a light-incident side on the light-incident side. For uniform light-emitting effect, the frame width of the assembled assembly can be reduced by reducing the coverage area of the hot spot phenomenon, and the light source can be effectively improved. The unevenness of the light formed by the distance, thereby achieving the effect of reducing the width of the frame and the cost of setting the light source.

[Knowledge Skills]

1‧‧‧Side-in backlight module

10‧‧‧Light guide plate

101‧‧‧Into the glossy surface

11‧‧‧LED

S ₁ ‧‧‧ bright area

S ₂ ‧‧ dark area

【this invention】

2‧‧‧Light guide plate

20‧‧‧light side

21‧‧‧ Reserved area

22‧‧‧Light guiding microstructure

23‧‧‧Lighting microstructure

24‧‧‧ surface

25‧‧‧Lighting area

3‧‧‧Light source

30‧‧‧Substrate

Θ‧‧‧ angle

FIG. 1 is a schematic diagram of a conventional side-entry backlight module.

Fig. 2 is a plan view showing an embodiment of the present invention.

Fig. 3 is a partially enlarged schematic view showing an embodiment of the present invention.

4A is a schematic cross-sectional view of a light guiding microstructure according to an embodiment of the present invention.

FIG. 4B is a schematic cross-sectional view of a light blocking microstructure according to an embodiment of the present invention.

Figure 5 is a plan view showing another embodiment of the present invention.

At present, many manufacturers have developed various improvement methods as described above in solving the hot spot phenomenon. In today's display panel production trend, in addition to solving the hot spots, it is also necessary to reduce the width of the frame in order to enlarge the displayable area. In addition, the frame of the display panel can be used to cover various components, and is also used to cover an area where the light-incident side of the light guide plate is prone to hot spots. In other words, in order to reduce the width of the frame, it is necessary to reduce the coverage of the bright and dark areas in the light guide plate, so that the light exiting the light side of the light guide plate becomes more uniform. The general design direction is based on adjusting the ratio of the width of the border of the display panel to the spacing of the light source of the backlight module. When the ratio of the width of the border to the spacing of the light source is smaller, the large area display area and the low light source setting can be met. The need for cost, for manufacturers, is the trend toward the best display panel design. In order to reduce the ratio of the width of the bezel to the spacing of the light source, the design direction is to reduce the width of the bezel and increase the spacing of the light source. Therefore, the inventors have effectively reduced the width of the bezel and reduced the area of the hot spot caused by the light guide plate. When the distance between the light sources is increased, the light-emitting side of the light guide plate is unevenly distributed, and the concept is repeated. With the experiment, a light guide plate of a narrow bezel display device is proposed.

Please refer to FIGS. 2, 3, 4A and 4B, which are schematic plan views, partially enlarged schematic views, schematic cross-sectional views of light guiding microstructures and schematic cross-sectional views of light blocking microstructures according to an embodiment of the present invention. The light guide plate 2 of the narrow bezel display device forms a light incident side 20 corresponding to the plurality of light sources 3, and includes a plurality of remaining regions 21, a plurality of light guiding microstructures 22 and a plurality of light blocking microstructures 23. The light sources 3 are respectively an LED and are arranged at intervals, and are combined by a substrate 30 to form a light strip pattern.

The retaining regions 21 are formed on the surface 24 of the light guide plate 2 from the light-incident side 20, and the surface 24 can be the light-emitting surface of the light guide plate 2 or the bottom surface disposed opposite to the light-emitting surface. Through the reserved area 21, the light enters the light guide plate 2 from the light entering side 20, thereby reducing unnecessary optical loss, and preventing the light from being affected by the slight uneven structure, thereby causing insufficient light energy for subsequent light-expanding. As described above, in order to prevent the light guide plate 2 from having too many minute structures to affect the light travel, the reserved regions 21 in a preferred state may be mirror-like, respectively, to minimize the optical loss of the light by using the flattened surface, and The angle of incident light of the light source 3, each of the reserved regions 21 is half-circular or inferior curved.

The light guiding microstructures 22 are disposed on the periphery of each of the remaining regions 21 on the surface 24 and are radially formed to form a light-emitting region 25 together with the remaining regions 21 . After entering the light guide plate 2, the light enters the light guide plate 2, and contacts the light guide microstructure 22 to change the light path, so that the light angle of the light in the light show area 25 is increased, so that the light of the adjacent light source 3 enters the light guide plate 2 After that, the overlapping range of light rays is enlarged, thereby reducing the dark area of the hot spot phenomenon area.

The light-blocking microstructures 23 are also disposed between the adjacent light-expanding regions 25 on the surface 24, and are arranged radially from the edge of the light-incident side 20 for intercepting light to form light. The light blocking microstructures 23 are located between adjacent light-expanding regions 25, that is, between adjacently disposed light sources 3, When the light is guided by the light guiding microstructure 22 to change the path, part of the light continues to the light blocking microstructure 23, and is further blocked by the light blocking microstructure 23 to form light at the place, effectively eliminating The original light guide plate corresponds to the dark area existing between the adjacent light sources 3, so that the light can be emitted in the dark area to enhance the light uniformity of the light incident side of the light guide plate 2. Therefore, the light guide plate 2 is combined with the reserved area 21, the light guiding microstructure 22 and the light blocking microstructure 23, so that the light enters the light guide plate 2 from the light entering side 20 in the state of maximum available energy, so as to avoid the light having not been polished before. That is, excessive energy consumption is caused, and the light is transmitted through the light guiding microstructure 22 to change the path of the path. Compared with the incident light angle of the original light source 3, the light extending angle guided by the light guiding microstructure 22 is expanded. The light rays of the adjacent light source 3 incident on the light guide plate 2 are increased, and then some of the light rays are forwarded and intercepted by the light intercepting microstructures 23 to emit light, so that the light guide plate 2 is originally located at two adjacent positions. The region between the light sources 3 can also form light, thereby uniformizing the light exiting state of the light guide plate 2 on the light incident side 20. As described above, the width of the frame of the display panel depends on the area of the bright and dark areas on the light-incident side 20 of the light guide plate 2. Therefore, after the light is incident on the light guide plate 2 and contacts the light-guiding microstructure 22 and the light-blocking microstructure 23, The light region 25 amplifies the light-expanding angle of the light, and uses the light-blocking microstructure 23 to make the light form a light in the area where the light is not originally formed, and reduces the area where the light-guide plate 2 generates a hot spot phenomenon, thereby reducing the subsequent assembly into the display panel. The required border width. Through the light guide plate 2 and the structural features thereon, even if the distance between the light sources of the light sources 3 is increased and the number of the light sources 3 is reduced, the problem that the distance between the light sources is too large and the dark area is increased does not occur, and the current display panel design can be met. The direction.

The light guiding microstructures 22 and the light blocking microstructures 23 may each be a groove, such as a V-shaped groove or an arc-shaped groove. In the present embodiment, the light guiding microstructures 22 of the V-shaped trenches and the light guiding microstructures 23 of the curved trenches are taken as an example, as shown in FIGS. 4A and 4B, but the light guiding microstructures 22 are The aspect of the light-blocking microstructure 23 is not limited thereto, and the visible light guide needs Find the groove shape design. In addition, in order to make the light-blocking microstructure 23 have better blocking and light-emitting efficiency for the light, the angle θ between the light-guiding microstructure 22 of the light-emitting region 25 and the long-axis direction of the adjacent light-blocking microstructure 23 is 85 degrees. ~95 degrees, the best system is 90 degrees vertically.

Please refer to FIG. 5, which is a schematic plan view of another embodiment of the present invention. In the present embodiment, each of the light guiding microstructures 22 and the light blocking microstructures 23 are arranged in a line-like manner by a plurality of dot-shaped grooves 221 and 231, and each of the dot-shaped grooves 221 and 231 may be an elliptical concave. Groove or 鸢-shaped groove. In this embodiment, each of the light guiding microstructures 22 is formed by an elliptical dot-shaped groove 221, and each of the light-blocking microstructures 23 is formed by a dot-shaped groove 231 which is a dome shape, as shown in FIG. Shown. By adjusting the orientations of the light guiding microstructures 22 and the light blocking microstructures 23, it is suitable to meet the optical requirements of the light source 3 or the light guide plate 2 to be achieved. The light-blocking microstructures 23 are arranged radially from the edge of the light-incident side 20 of the light guide plate 2, so as to prevent the light-guide plate 2 from being cracked when the edge of the light-incident side 20 is provided with too many dot-shaped grooves 231, When the optical microstructures 23 are respectively formed by the dot-shaped grooves 231, the number of the dot-shaped grooves 231 which are adjacent to the edge of the light-incident side 20 is smaller, preferably in the embodiment shown in the present embodiment. The number of 231 increases from adjacent light entrance side 20 toward away from light entrance side 20.

In summary, the light guide plate of the narrow bezel display device disclosed in the present invention can effectively reduce the light emitted from the adjacent light incident side by using the reserved area disposed on the surface of the light guide plate, the light guiding microstructure and the light blocking microstructure. In the meantime phenomenon, the light guiding microstructure is used to enhance the light-expanding angle of the light incident on the light guide plate, thereby expanding the range of the bright region, and simultaneously guiding the partial light to the dark region formed between the adjacent adjacent light sources through the light-blocking microstructure. Light-emitting, to achieve the effect of blocking light and forming light, compared with the conventional light guide plate, the light guide plate of the invention has a more uniform light-emitting effect on the light-incident side, and is assembled by reducing the coverage area of the hot spot phenomenon. The width of the border is decreasing and increasing When the distance between the light sources is used, there is no need to worry about amplifying the coverage of the dark areas, thereby reducing the ratio of the width of the border to the spacing of the light sources, thereby realizing the application of the narrow border display device.

However, the above description is only for the preferred embodiment of the present invention and is not intended to limit the scope of the present invention; therefore, equivalent changes and modifications may be made without departing from the spirit and scope of the invention. Within the scope of the patent of the present invention.

2‧‧‧Light guide plate

20‧‧‧light side

21‧‧‧ Reserved area

22‧‧‧Light guiding microstructure

23‧‧‧Lighting microstructure

24‧‧‧ surface

25‧‧‧Lighting area

3‧‧‧Light source

30‧‧‧Substrate

Θ‧‧‧ angle

Claims (10)

a light guide plate of a narrow bezel display device, which forms a light incident side corresponding to the plurality of light sources, comprising: a plurality of reserved regions corresponding to the light source from the light incident side, formed on one surface of the light guide plate; and a plurality of light guiding microstructures, Arranging on the surface of each of the reserved areas, radially arranged, and further forming a light-expanding area with the reserved area; and a plurality of light-blocking microstructures disposed on the surface of the adjacent light-expanding sections, and The edges of the light-incident side are radially arranged to intercept light and form light. The light guide plate of the narrow bezel display device of claim 1, wherein the light guide microstructures are a groove. The light guide plate of the narrow bezel display device according to claim 1, wherein each of the light guiding microstructures is arranged by a plurality of dot-like grooves to form a linear-like state. The light guide plate of the narrow bezel display device of claim 3, wherein the punctiform groove is an elliptical groove. The light guide plate of the narrow bezel display device according to claim 3, wherein the dot-shaped groove is a meandering groove. The light guide plate of the narrow bezel display device of claim 1, wherein the guiding microstructure of the light-expanding region forms an angle of 85 to 95 degrees with the longitudinal direction of the adjacent light-blocking microstructure. The light guide plate of the narrow bezel display device of claim 1, wherein the light blocking microstructures are a groove. The light guide plate of the narrow bezel display device of claim 1, wherein each of the light-blocking microstructures is arranged by a plurality of dot-like grooves to form a linear-like state. The light guide plate of the narrow bezel display device according to claim 8, wherein the dot concave The slot is an elliptical groove. The light guide plate of the narrow bezel display device of claim 8, wherein the dot-shaped groove is a meandering groove.