CN105929481A - Backlight module and light guide plate thereof - Google Patents

Abstract

The invention relates to a backlight module and a light guide plate thereof, comprising: a light guide plate, comprising: the light-transmitting plate body comprises a light-in side surface and a light-out surface adjacent to the light-in side surface, wherein the light-out surface is divided into a surface light source area and a surrounding area surrounding the surface light source area; a first density microstructure pattern distributed in the area of the surface light source; and a plurality of second density microstructure patterns, located in the surrounding area, the second density being greater than the first density and linearly arranged along the light incident side; and a light source assembly, comprising: a substrate; the plurality of point light sources are linearly arranged on the substrate and face the light incidence side face at intervals, a spacing area is defined between any two adjacent point light sources, and each second-density microstructure pattern is aligned with one of the spacing areas; wherein each second density microstructure pattern is an isosceles trapezoid.

Description

A kind of backlight module and its light guide plate

technical field

The invention relates to a light guide plate, and in particular to a light guide plate of a backlight module.

Background technique

Backlight modules are divided into direct-type backlight modules and side-type backlight modules. The side-type backlight module has a structure in which the light source is arranged to face one side of the light guide plate, and a plurality of optical sheets are arranged between the liquid crystal panel and the light guide plate. In an edge-lit backlight module, a light source irradiates light to one side of a light guide plate and the light guide plate converts a line light source or a point light source into a surface light source.

Among the two backlight modules, the edge-type backlight module has a problem of a hot spot phenomenon due to providing light to one side of the light guide plate. 1 is a view for explaining the problem of hot spots, which is a top plan view selectively showing a light guide plate 10 and light emitting diodes LED1, LED2 serving as light sources. As shown in FIG. 1 , the first light emitting diode LED1 and the second light emitting diode LED2 are disposed on one side so as to face the edge of the light guide plate 10 . As we all know, light emitting diodes are directional elements, so light enters the light guide plate 10 at a predetermined direction angle (α). Thus, there is a portion where the light from the first light emitting diode LED1 and the light from the second light emitting diode LED2 are not mixed together (hatched portion in FIG. 1 , hereinafter referred to as “hatched area GA”). Therefore, the shaded area GA looks dark, and a portion where light comes from the first light emitting diode LED1 and the second light emitting diode LED2 (hereinafter referred to as "light emitting area WA") looks bright, thereby producing a difference in brightness according to positions and causing Hot Issues. Due to the hot spots, the incident surface of the light guide plate 10 facing the light emitting diodes has a wavy pattern. Since the light guide plate is a part that turns a point light source into a surface light source and supplies light to a liquid crystal panel placed above it, if the light appears wavy, the brightness of the liquid crystal panel becomes uneven due to the wavy pattern of the light guide plate, Thus, an image cannot be properly displayed in a desired shape. A simple way to overcome this hot spot problem is to increase the number of LEDs. That is, the hot spot problem can be overcome by arranging the LEDs densely enough to prevent the formation of the shadow area GA shown in FIG. 1 . However, such an increase in the number of light emitting diodes requires higher power consumption, which is not desirable. Another way is to increase the size of the border so that the hotspot is partially blocked and not visible.

The liquid crystal panel and the backlight unit are generally packaged in a case: the rear cover and the front cover are combined to encapsulate the liquid crystal panel and the backlight unit interposed therebetween. During packaging, the edges of the liquid crystal panel are blocked by the front cover. The part of the LCD panel blocked by the front cover is called the bezel.

The bezel covers the liquid crystal panel on the front, thereby reducing the size of a display area where the liquid crystal panel displays images. Recently released liquid crystal display devices reduce the size of bezels to have an enlarged display area, which is attractive to consumers in terms of design. As such, the method of increasing the bezel size for the purpose of solving the hot spot problem is not advantageous due to the reduction of the display area and is unfavorable in terms of design.

It can be seen that the above-mentioned light guide plate still has inconveniences and defects, and needs to be further improved. Therefore, how to effectively solve the above-mentioned inconveniences and defects is one of the current important research and development topics, and it has also become an urgent need for improvement in related fields.

Contents of the invention

The technical problem to be solved by the present invention is to provide a backlight module and its light guide plate in order to overcome the disadvantages of poor optical effect of the traditional backlight module in the prior art, and the decrease of the overall light utilization efficiency and uniformity.

The present invention solves the above technical problems through the following technical solutions:

A backlight module, characterized in that it comprises:

A light guide plate, comprising:

A light-transmitting plate body, including a light incident side and a light exit surface adjacent to the light incident side, the light exit surface is divided into a surface light source area and a surrounding area surrounding the surface light source area;

a first density microstructure pattern distributed in the area of the surface light source; and

A plurality of second-density microstructure patterns are located in the surrounding area and arranged linearly along the light-incident side, wherein the second density is greater than the first density;

as well as

A light source assembly, including:

a substrate; and

A plurality of point light sources are arranged linearly on the substrate and face the light-incident side at intervals, wherein a space area is defined between any two adjacent point light sources, and each second-density microstructure pattern is aligned one of the compartmental areas;

wherein each second-density microstructure pattern is an isosceles trapezoid,

The length of the lower base of the isosceles trapezoid is equal to the distance between any two adjacent point light sources, the length of the upper base is half of the length of the lower base, and a width of the surrounding area is equal to an upper base of the trapezoid The length of the side.

Preferably, the microstructure depth of the microstructure pattern of the second density is not less than 34 microns, and the radius is not less than 59 microns.

Preferably, the light-incident side is a serrated surface.

Preferably, along the direction away from the light-incident side, the density of the first-density microstructure pattern gradually increases.

The present invention also provides a light guide plate, characterized in that the light guide plate comprises:

A light-transmitting plate body, including a surface light source area and a transition area, the transition area is long and narrow, and is located between the surface light source area and the light-incident side;

a first density microstructure pattern distributed in the area of the surface light source; and

A plurality of second-density microstructure patterns, each of these second-density microstructure patterns is an isosceles trapezoid, located in the transition region, and the length of the lower base of the isosceles trapezoid is equal to any two adjacent ones The distance between point light sources, the length of the upper base is half of the length of the lower base. The width of the surrounding area is equal to the length of an upper base of the trapezoid, and it is interlaced with the point light sources arranged at intervals; the microstructure depth of the second density microstructure pattern is not less than 34 microns, and the radius is not less than 59 microns;

Along the direction away from the light incident side, the density of the first density microstructure pattern gradually increases;

Wherein, when the point light sources arranged at intervals emit light, the microstructure patterns of the second density form a pseudo light source between any two of the point light sources arranged at intervals, thereby diluting the optical bright spots.

On the basis of conforming to common knowledge in the field, the above-mentioned preferred conditions can be combined arbitrarily to obtain preferred examples of the present invention.

The positive progress effect of the present invention is:

These isosceles trapezoidal second-density microstructure patterns of the present invention can provide a pseudo light source between any two optical bright spots corresponding to the transition area, thereby uniformizing the brightness of the transition area, thereby weakening the obvious difference between the optical bright spots and dark areas. Compared.

Description of drawings

FIG. 1 is a view of the hot spot problem of a light guide plate of a backlight module in the prior art.

Fig. 2 is a schematic structural view of the light guide plate of the present invention.

FIG. 3 is a schematic structural view of a light guide plate of a comparative example of the present invention.

detailed description

The specific implementation manners of the present invention will be disclosed in the following figures. For the sake of clarity, many practical details will be described together in the following description. It should be understood, however, that these practical details should not be used to limit the invention. That is, in some embodiments of the present invention, these practical details are unnecessary. In addition, for the sake of simplifying the drawings, some well-known structures and components will be shown in a simple and schematic manner in the drawings.

Fig. 2 shows a schematic structural diagram of a light guide plate according to an embodiment of the present invention. As shown in Figure 2, a backlight module includes: a light guide plate 1, including: a light-transmitting plate body 2, including a light incident side and a light exit surface adjacent to the light incident side, the light exit surface is divided into one side The light source area B and a surrounding area A surrounding the surface light source area B; a first density microstructure pattern 3 distributed in the surface light source area; and a plurality of second density microstructure patterns 4 located in the surrounding area, and arranged linearly along the light-incident side, wherein the second density is greater than the first density; and a light source assembly 5, comprising: a substrate 6; and a plurality of point light sources 7, arranged linearly on the substrate, and facing at intervals On the light-incident side, a spacer region C is defined between any two adjacent point light sources, and each of the second density microstructure patterns is aligned with one of the spacer regions; wherein each second density microstructure pattern is aligned with one of the spacer regions; The shape of the structural pattern is an isosceles trapezoid.

In this way, when these point light sources arranged at intervals emit light on the light-incident side to generate optical hot spots, the above-mentioned isosceles trapezoidal second-density microstructure patterns 4 can be formed at positions corresponding to any two optical bright spots (hot spots) Pseudo-light sources, allowing these optical bright spots to mix with these pseudo-light sources, thereby uniformizing the brightness, thereby weakening the obvious contrast between optical bright spots and dark areas.

More specifically, the length of the lower base of the isosceles trapezoid is equal to the distance between any two adjacent point light sources, and the length of the upper base is half of the length of the lower base. A width of the surrounding area is equal to a length of an upper base of the trapezoid. Preferably, the light-incident side is a serrated surface. Preferably, along the direction away from the light-incident side, the density of the first-density microstructure pattern gradually increases. And its specific shape can be controlled by adjusting the three parameters of the upper and lower bases and sides of the isosceles trapezoid.

In this embodiment, each microstructure pattern of the second density is composed of a plurality of optical microstructures, and these optical microstructures are distributed at intervals. For example, on a design example of a 46-inch light guide plate with a thickness of 2 mm, the above-mentioned optical microstructure is realized with dots with a depth of 30 microns and a radius of 50 microns, and the distribution density of the second density microstructure pattern 130 can be 60% to 70%. The distribution density refers to the ratio of the total area of multiple optical microstructures to the area of the second density microstructure pattern; When using light sources, denser or deeper optical microstructures are required. It is verified by actually making samples that the optical uniformity can reach more than 75%. However, the present invention is not limited thereto, and those with ordinary knowledge in the technical field to which the present invention pertains can also change the distribution density to other ranges according to actual needs.

Fig. 3 is a partially enlarged view of a comparative example of the present invention. In Fig. 3, the structure of the light guide plate of this comparative example is roughly the same as that of the above-mentioned light guide plate, and one of the differences is that the second density microstructure pattern 4 is a square, which is the invention. According to the square second density microstructure pattern 4, the optical uniformity of the transition area is about 60%. It can be seen that, compared with the square second-density microstructure pattern 4 , when the second-density microstructure pattern 4 is isosceles trapezoidal, a better light uniformity result can be obtained. Therefore, the shape of the microstructure pattern of the second density cannot be equivalently replaced by any pattern.

In addition, for the comparative example in which the microstructure pattern 4 of the second density is semi-elliptical (not shown, the difference is that the microstructure pattern 4 of the second density is semi-elliptical), the optical uniformity of the transition region is about 60-70%, It can be seen from the above that when the microstructure pattern 4 of the second density is in the shape of an isosceles trapezoid, a better light uniformity result can be obtained.

Although the specific implementation of the present invention has been described above, those skilled in the art should understand that this is only an example, and the protection scope of the present invention is defined by the appended claims. Those skilled in the art can make various changes or modifications to these embodiments without departing from the principle and essence of the present invention, but these changes and modifications all fall within the protection scope of the present invention.

Claims (5)

1. a backlight module, it is characterised in that comprise:

One light guide plate, comprises:

One printing opacity plate body, comprises a light incident sides and an exiting surface adjoining this light incident sides, and this exiting surface is divided into a source region with one around the cincture district in this area source region；

One first density micro structured pattern, is distributed in this area source region；And

Multiple second density micro structured pattern, are positioned at this cincture district, and along this light incident sides linear arrangement, the most above-mentioned second density is more than above-mentioned first density；

And

One light source assembly, comprises:

One substrate；And

Plurality of points light source, linear arrangement is on this substrate, and compartment of terrain is in the face of this light incident sides, and between those point sources that any two of which is adjacent, definition has an interval region, and each second density micro structured pattern alignment interval region one of them；

Each of which the second density micro structured pattern for an isosceles trapezoid,

Distance between those point sources that the bottom length of this isosceles trapezoid is adjacent equal to any two, the half of a length of bottom, upper base length, the width in this cincture district is equal to the length on this trapezoidal upper base.

Backlight module the most according to claim 1, it is characterised in that the depth of microstructure of described second density micro structured pattern is not less than 34 microns, radius is not less than 59 microns.

A kind of backlight module the most according to claim 1, it is characterised in that described light incident sides is serrated face.

Backlight module the most according to claim 1, it is characterised in that along deviating from the direction of described incidence surface, the density of described first density micro structured pattern is gradually increased.

5. a light guide plate, it is characterised in that this light guide plate includes:

One printing opacity plate body, including a source region and a transitional region, this transitional region is long and narrow, and between area source region and this light incident sides；

One first density micro structured pattern, is distributed in this area source region；And

A plurality of second density micro structured pattern, each second density micro structured pattern is in an isosceles trapezoid, it is positioned at this transitional region, distance between those point sources that the bottom length of this isosceles trapezoid is adjacent equal to any two, the half of a length of bottom, upper base length, one width in this cincture district is equal to this length on base on trapezoidal one and interwoven with those point sources spaced；The depth of microstructure of described second density micro structured pattern is not less than 34 microns, and radius is not less than 59 microns；Along deviating from the direction of described light incident sides, the density of described first density micro structured pattern is gradually increased；Wherein, when those point light source light-emittings spaced, those the second density micro structured pattern form pseudo-light source, and then desalination optics bright spot between any two those point sources spaced.