CN102818196B - Backlight module and display device - Google Patents

Abstract

The invention relates to the field of display technology, and discloses a backlight module, including a luminous body and a light guide plate, the luminous body is composed of a plurality of LEDs, the light guide plate includes a base material of the light guide plate, and the base material includes an incident surface for receiving light beams, The illuminant is arranged on the side of the incident surface, and an optical resin pattern is formed on the incident surface, and its pattern area is located between any two adjacent LEDs, and the refractive index of the optical resin pattern is not equal to that of the light guide plate substrate . The invention also discloses a display device. In the present invention, an optical resin pattern located between any adjacent LEDs is formed on the incident surface of the base material of the light guide plate, so that the light emitted by the LED is refracted twice through the optical resin pattern and the light guide plate, and the path of the light emitted by the LED changes. The light divergence angle is enlarged, the range of the dark area is reduced or even completely eliminated, the phenomenon of alternation of light and dark on the light guide plate is effectively improved, and the display quality of the display device is improved.

Description

Backlight module and display device

technical field

The invention relates to the field of display technology, in particular to a backlight module and a display device.

Background technique

Existing backlight modules mainly have two lighting methods: side-in and direct-down. For the backlight module with side-in lighting and LED as the light source, the schematic diagram of the light guide plate is shown in Figure 1. LED2 and the guide There is a certain distance between the light boards 1, which is limited by the light emitting angle of the LED2, and the light emitting angle of the LED2 is generally 120 degrees. Since the gap between the LED2 and the light guide plate 1 cannot be too large, the dark area 3 between the adjacent LED2 as shown in Figure 1 often occurs, causing the phenomenon of alternating light and dark on the light guide plate 1, which is called a hot spot. , affecting the display quality of the display device.

Contents of the invention

(1) Technical problems to be solved

The technical problem to be solved by the present invention is how to improve the alternating light and dark phenomenon on the light guide plate.

(2) Technical solutions

In order to solve the above technical problems, the present invention provides a backlight module, which includes a luminous body and a light guide plate, the luminous body is composed of a plurality of LEDs, the light guide plate includes a light guide plate base material and The incident surface on the material is used to receive light beams, the illuminant is arranged on the side of the incident surface, an optical resin pattern is formed on the incident surface, and the pattern area of the optical resin pattern is located between any adjacent two LEDs. Between, the refractive index of the optical resin pattern is not equal to the refractive index of the light guide plate base material.

Wherein, the thickness of the optical resin pattern is greater than the distance between the LED and the incident surface of the light guide plate.

Wherein, the refractive index of the optical resin material selected for the optical resin pattern is 1.3-1.8.

Wherein, the refractive index of the optical resin material selected for the optical resin pattern is greater than that of the base material of the light guide plate.

Wherein, the optical resin material is one of carbon propylene acetate, polycarbonate, polystyrene, boron silicate or polytetrafluoroethylene.

Wherein, the light guide plate further includes a bottom surface formed on the base material of the light guide plate and connected to the incident surface, and an outgoing surface connected to the incident surface and opposite to the bottom surface.

Wherein, the incident surface is at least one of the side surfaces connecting the bottom surface and the outgoing surface on the light guide plate substrate.

Wherein, the light guide plate further includes a side surface formed on the base material of the light guide plate and connected to the incident surface, and an exit surface connected to the side surface and opposite to the incident surface.

The present invention also provides a display device, which includes the backlight module described in any one of the above.

(3) Beneficial effects

In the backlight module and the corresponding display device provided by the above technical solution, by forming an optical resin pattern between any adjacent LEDs on the incident surface of the light guide plate substrate, the light emitted by the LED is generated through the optical resin pattern and the light guide plate. With two refractions, the path of the light emitted by the LED changes, expanding the divergence angle of the light, reducing or even completely eliminating the range of the dark area, effectively improving the phenomenon of alternating light and dark on the light guide plate, and improving the display quality of the display device.

Description of drawings

FIG. 1 is a schematic diagram of light guiding of a backlight module in the prior art;

FIG. 2 is a schematic diagram of a partial structure of a backlight module according to Embodiment 1 of the present invention;

FIG. 3 is a schematic diagram of light guiding of the backlight module according to Embodiment 1 of the present invention.

Among them, 1: light guide plate; 2: LED; 3: dark area; 4: optical resin pattern.

detailed description

The specific implementation manners of the present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments. The following examples are used to illustrate the present invention, but are not intended to limit the scope of the present invention.

Example 1

Fig. 2 has shown the partial structure schematic diagram of the backlight module of this embodiment, referring to the drawing, this backlight module comprises illuminant and light guide plate 1, and described illuminant is made up of a plurality of LED2, and described light guide plate 1 comprises The base material of the light plate and the incident surface formed on the base material of the light guide plate to receive light beams, the luminous body is arranged on the side of the incident surface, the optical resin pattern 4 is formed on the incident surface, and the optical resin The graphic area of the pattern 4 is located between any two adjacent LEDs 2 , and the refractive index of the optical resin pattern 4 is not equal to that of the light guide plate base material. Fig. 3 has shown the light guide schematic diagram of the backlight module of this embodiment, and the structural setting shown in Fig. 2 can make the light that LED2 emits enter optical resin pattern 4 by air first, light refraction occurs once, and then by optical resin pattern 4 Entering the light guide plate 1, because the refractive index of the optical resin pattern 4 is not equal to the refractive index of the light guide plate base material of the light guide plate 1, the second refraction occurs again. When the light divergence angle is increased, the range of the dark area is reduced or even completely eliminated, thereby improving the hot spot phenomenon.

Wherein, the thickness of the optical resin pattern 4 is greater than the distance between the LED 2 and the light guide plate 1, which can fully ensure that the light emitted by the LED 2 enters the optical resin pattern 4 from the side, and the optical path will change based on Fresnel's law.

In order to effectively expand the light divergence angle of the LED2, the material of the optical resin pattern 4 is selected from a material with a high refractive index, preferably between 1.3 and 1.8, and the refractive index of the optical resin pattern is greater than the refractive index of the light guide plate substrate, specifically Any one of materials such as carbon propylene acetate, polycarbonate, polystyrene, borosilicate or polytetrafluoroethylene can be selected.

Taking Fig. 3 as an example, the light emitted by LED 2 hits the optical resin pattern at an incident angle i, the light is refracted for the first time, and the refraction angle is α, and the refracted light is directed to the light guide plate 1 by the optical resin pattern 4 again, and the second refraction occurs. secondary refraction; the incident angle of the second refraction is β, β and α are complementary angles to each other, and the refraction angle of the second refraction is γ. According to the detailed description in the figure, after two refractions, the light divergence angle is enlarged, The effect of reducing the range of dark areas or even eliminating them must at least meet Note that the refractive index of air is n ₀ , the refractive index of the optical resin pattern is n ₁ , and the refractive index of the light guide plate is n ₂ , obviously n ₀ <n ₁ , in order to effectively expand the divergence angle of the above light, preferably n ₂ <n ₁ , because the material of the base material of the light guide plate is usually plexiglass, its refractive index n ₂ is between 1.3-1.6, and the refractive index n ₁ of the optical resin pattern is selected between 1.3-1.8, which can satisfy n ₁ and n ₀ and The deviation of n ₂ will not be too large. If the value of n ₁ is too large, the refraction angle α is too small, β is too large, and further γ is too large, the direction of the light emitted from the light guide plate 1 will deviate too much from the expected direction, which will affect the backlight. The uniformity of the light distribution of the module; if the value of n ₁ is too small, the refraction angle α is too close to the incident angle i, the light divergence angle cannot be effectively expanded, and the dark area problem cannot be effectively solved.

In this embodiment, n ₁ is selected between 1.3-1.8, and n ₂ <n ₁ , the light path diagram of the light is exactly the same as that in Figure 3, the light is refracted twice, and each refraction can diverge the light to a certain extent The angle is enlarged, thereby reducing or completely eliminating the range of dark areas in the light guide plate, and significantly improving the brightness and light uniformity of the backlight module.

The backlight module structure provided in this embodiment is suitable for both edge-lit backlight modules and direct-lit backlight modules.

When the backlight module is an edge-light type, the light guide plate further includes a bottom surface formed on the base material of the light guide plate and connected to the incident surface, and an exit surface connected to the incident surface and opposite to the bottom surface. Wherein, the incident surface is at least one of the sides connecting the bottom surface and the outgoing surface of the light guide plate substrate. The light entering from the incident surface is reflected by the bottom surface, and then exits from the exit surface.

When the backlight module is a direct type, the light guide plate substrate further includes a side surface connected to the incident surface, and an exit surface connected to the side surface and opposite to the incident surface. The light entering from the incident surface is directly emitted from the exit surface.

The backlight module provided by this embodiment can significantly improve the brightness and light uniformity of the backlight module because the range of the dark area in the light guide plate is reduced or completely eliminated.

Example 2

This embodiment provides a display device, which is set based on the backlight module in Embodiment 1. The display panel and the backlight module are assembled to form a display device. Because the brightness of the backlight module is high, bright and dark lines appear in the backlight module. The probability of is very low, thereby improving the display quality of the display device.

It can be seen from the above embodiments that the present invention forms an optical resin pattern between any adjacent LEDs on the incident surface of the light guide plate base material, so that the light emitted by the LED is refracted twice through the optical resin pattern and the light guide plate, and the LED The emitted light path is changed, the divergence angle of the light is expanded, the range of the dark area is reduced or even eliminated, the phenomenon of alternating light and dark on the light guide plate is effectively improved, and the display quality of the display device is improved.

The above is only a preferred embodiment of the present invention, it should be pointed out that for those of ordinary skill in the art, without departing from the technical principle of the present invention, some improvements and replacements can also be made, these improvements and replacements It should also be regarded as the protection scope of the present invention.

Claims (7)

1. A backlight module, characterized in that it comprises a luminous body and a light guide plate, the illuminant is made up of a plurality of LEDs, the light guide plate comprises a light guide plate base material and is formed on the light guide plate base material for The incident surface receiving the light beam, the illuminant is arranged on the side of the incident surface, an optical resin pattern is formed on the incident surface, and the graphic area of the optical resin pattern is located between any adjacent two LEDs, so The refractive index of the optical resin pattern is not equal to the refractive index of the light guide plate substrate; the thickness of the optical resin pattern is greater than the distance between the LED and the incident surface of the light guide plate; Wherein, the refractive index of the optical resin material selected for the optical resin pattern is greater than that of the base material of the light guide plate. 2 . The backlight module according to claim 1 , wherein the optical resin material selected for the optical resin pattern has a refractive index of 1.3˜1.8. 3 . The backlight module according to claim 2 , wherein the optical resin material is one of carbon acrylate, polycarbonate, polystyrene, borosilicate or polytetrafluoroethylene. 4. The backlight module according to claim 1, wherein the light guide plate further comprises a bottom surface formed on the base material of the light guide plate and connected to the incident surface, connected to the incident surface and opposite to the bottom surface exit surface. 5 . The backlight module according to claim 4 , wherein the incident surface is at least one of the sides connecting the bottom surface and the outgoing surface of the light guide plate substrate. 6 . 6. The backlight module according to claim 1, wherein the light guide plate further comprises a side surface formed on the base material of the light guide plate and connected to the incident surface, connected to the side surface and connected to the incident surface. face opposite to the exit face. 7. A display device, comprising the backlight module according to any one of claims 1-6.