LED backlight source and high-contrast backlight module

Abstract

The application belongs to the technical field of LED display, and provides an LED backlight source, which comprises a printed circuit board and an LED array; the LED array comprises at least two point light sources, the at least two point light sources are arranged on the printed circuit board in the form of array distribution, each of the point light sources comprises an LED chip, a connecting layer and an optical layer; in the LED array, at least one of the point light sources is a double-core point light source, the double-core point light source comprises two LED chips, which are a first LED chip for improving a dynamic light adjusting effect and a second LED chip for ensuring uniform light emission; the light emission angle of the first LED chip is smaller than that of the second LED chip, and the first LED chip and the second LED chip can be controlled individually. The application further provides a high-contrast backlight module. The application not only maintains uniform light emission, but also enhances the light adjusting contrast effect, and is beneficial to realizing high contrast of the backlight module.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of LED display, and particularly relates to an LED backlight source and a high-contrast backlight module. BACKGROUND

[0002] The dynamic light modulation technology of the LED backlight source has high contrast and excellent display effect, and gradually becomes a hotspot in the market of LED backlight products. The dynamic light modulation needs multiple partitions to control multiple light sources to be realized. The light emitted by the LED passes through a certain light mixing distance and is irradiated onto a diffusion plate to form a planar light source. The uniformity of the light mixing will affect the display effect.

[0003] In order to realize uniform display effect, the light emitting angle of the LED is continuously increased. A commonly used technology is to increase a Bragg reflection layer on the surface of the chip or to increase a semi-transparent reflection layer on the surface. However, increasing the light emitting angle of the LED will cause the light to overlap to a certain extent, thereby causing the effect in the dynamic light modulation to be poor. Therefore, how to increase the effect of the dynamic light modulation in the degree of uniform light color is a problem to be solved at present. SUMMARY

[0004] In order to overcome the above-mentioned shortcomings of the prior art, the purpose of the present application is to provide an LED backlight source which is uniform in light emission and can be finely modulated, thereby being beneficial to improving the dynamic light modulation effect of the backlight source.

[0005] The technical scheme adopted by the present application to solve its technical problems is:

[0006] An LED backlight source comprises a printed circuit board and an LED array. The LED array comprises at least two point light sources which are arranged on the printed circuit board in the form of an array. Each point light source comprises an LED chip, a connecting layer and an optical layer.

[0007] In the LED array, at least one point light source is a double-core point light source which comprises two LED chips, i.e. a first LED chip for improving the dynamic light modulation effect and a second LED chip for ensuring uniform light emission. The light emitting angle of the first LED chip is smaller than that of the second LED chip, and the first LED chip and the second LED chip can be controlled individually.

[0008] Preferably, the light emitting angle of the first LED chip is 100°-125°.

[0009] Preferably, the light emitting angle of the second LED chip is 130°-170°.

[0010] Preferably, the second LED chip is provided with a light reflection structure, and the light reflection structure comprises a plurality of Bragg reflection layers.

[0011] Preferably, the surface of the first LED chip is sequentially covered with a light transmission layer and a light reflection layer.

[0012] Preferably, the optical layer comprises two layers.

[0013] Preferably, in the LED array, all the point light sources are the double-core point light sources.

[0014] Preferably, in the LED array, a plurality of double-core point light sources and a plurality of single-core point light sources are contained, and each double-core point light source and each single-core point light source are arranged in an array with intervals.

[0015] Preferably, in the LED array, a plurality of double-core point light sources and a plurality of single-core point light sources are contained, and the plurality of double-core point light sources and the plurality of single-core point light sources are arranged in an array with intervals in columns or rows on the printed circuit board.

[0016] Another object of the present application is to provide a high-contrast backlight module comprising the above LED backlight source.

[0017] A high-contrast backlight module comprises the above LED backlight source, a cavity for accommodating the LED backlight source, a reflective film, a driving IC, an element, and a light conversion assembly; the LED backlight source, the reflective film, the driving IC, and the element are arranged in the cavity; the light conversion assembly is arranged at an opening of the cavity, and the light conversion assembly comprises a diffusion plate, a light conversion layer, and an optical film layer arranged in sequence in a light emission direction.

[0018] Compared with the prior art, the present application has the following advantages:

[0019] The LED backlight source of the present application arranges a point light source comprising a first LED chip and a second LED chip in an LED array, and the light emitting angles of the first LED chip and the second LED chip are different, so that the light emission is uniform under the action of the second LED chip with a larger light emitting angle, and the first LED chip with a smaller light emitting angle can be dynamically dimmed to ensure that the adjusted light does not overlap, which is beneficial to improving the dynamic dimming effect. The LED backlight source of the present application not only maintains uniform light emission, but also enhances the dimming contrast effect.

[0020] The backlight module of the present application, wherein the LED backlight source maintains uniform light emission and enhances the dimming contrast effect, which is beneficial to realizing high contrast of the backlight module. BRIEF DESCRIPTION OF DRAWINGS

[0021] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings needed in the embodiment description will be briefly introduced. Obviously, the drawings in the following description are some embodiments of the present application, and other drawings can be obtained by those skilled in the art without any creative effort.

[0022] Figure 1 A side view of the double-core point light source in the LED backlight source of the embodiment 1 of the present application.

[0023] Figure 2 A top view of the double-core point light source in the LED backlight source of the embodiment 1 of the present application.

[0024] Figure 3 A light ray schematic diagram of the double-core point light source in the LED backlight source of the embodiment 1 of the present application when only the second LED chip is lighted.

[0025] Figure 4 A light ray schematic diagram of the double-core point light source in the LED backlight source of the embodiment 1 of the present application when the first LED chip and the second LED chip are lighted simultaneously.

[0026] Figure 5 A front view of the LED backlight source of the embodiment 1 of the present application.

[0027] Figure 6 A front view of the high-contrast backlight module of the embodiment 1 of the present application.

[0028] Figure 7 A side view of the double-core point light source in the LED backlight source of the embodiment 2 of the present application.

[0029] Figure 8 A front view of the LED backlight source of the embodiment 2 of the present application.

[0030] Figure 9 A side view of the double-core point light source in the LED backlight source of the embodiment 3 of the present application.

[0031] Figure 10 A front view of the LED backlight source of the embodiment 3 of the present application.

[0032] Wherein:

[0033] 1-printed circuit board, 2-first LED chip, 3-second LED chip, 4-optical layer, 5-connection layer, 6-double-core point light source, 7-single-core point light source, 8-optical film layer, 9-light conversion layer, 10-diffusion plate, 11-cavity, 12-reflective film, 13-driving IC, 14-element, 15-translucent layer, 16-reflective layer. DETAILED DESCRIPTION

[0034] In order to enable a more clear understanding of the above-mentioned objects, features and advantages of the present application, the present application will be described in detail below with reference to the accompanying drawings and specific embodiments. It should be noted that the embodiments and features of the embodiments in the present application can be combined with each other without conflict. In the following description, a large number of specific details are set forth in order to facilitate a full understanding of the present application. The described embodiments are only some of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor, fall within the scope of protection of the present application.

[0035] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used in the description of the application herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application.

[0036] Embodiment 1

[0037] Referring to Figures 1-6 , the embodiment discloses an LED backlight source, comprising a printed circuit board 1 and an LED array; the LED array comprises a plurality of point light sources, the plurality of point light sources are arranged in an array distribution on the printed circuit board 1, each of the point light sources comprises an LED chip, a connecting layer 5 and an optical layer 4.

[0038] In the LED array, all the point light sources are double-core point light sources 6, the double-core point light sources 6 comprise two LED chips, which are a first LED chip 2 for improving dynamic dimming effect and a second LED chip 3 for ensuring uniform light emission; the light emission angle of the first LED chip 2 is smaller than that of the second LED chip 3, and the first LED chip 2 and the second LED chip 3 can be independently controlled. The first LED chip 2 and the second LED chip 3 in the embodiment are both flip chips, the size of the first LED chip 2 is 200um*400um, and the size of the second LED chip 3 is also 200um*400um.

[0039] In the embodiment, the connecting layer 5 is connected between the LED chip and the printed circuit board 1, the optical layer 4 covers the first LED chip 2 and the second LED chip 3, and the optical layer 4 is arranged in a hemispherical shape. The optical layer 4 in the embodiment is a layer composed of silica gel.

[0040] Further, the first LED chip 2 of the embodiment has a light emitting angle of 100°-125°, specifically 120°. When only the first LED chip 2 of all the point light sources in the LED backlight source is lighted, the light emitted through the optical layer 4 can form the effect of bright above the chip and dark between the chips on the diffusion plate 10 layer of the backlight module.

[0041] Further, the second LED chip 3 of the embodiment has a light emitting angle of 130°-170°, specifically 150°. When only the second LED chip 3 of all the point light sources in the LED backlight source is lighted, the light emitted through the optical layer 4 can form a uniform surface light source on the diffusion plate 10 layer of the backlight module. See Figure 3 At this time, only the second LED chip 3 is lighted, and the light overlaps between the point light sources, ensuring uniform light emission.

[0042] In dynamic dimming, local dimming can be performed by adjusting the first LED chip 2 and the second LED chip 3 at the same time. The embodiment provides the first LED chip 2 with a smaller light emitting angle, which can enhance the effect of local dimming. Specifically, see Figure 4 At this time, the first LED chip 2 and the second LED chip 3 are lighted at the same time. The light emitted by the second LED chip 3 (solid line) ensures uniform light emission, and the light emitted by the first LED chip 2 (dashed line) does not overlap due to the small light emitting angle, thus producing a better dimming effect.

[0043] Further, a light reflecting structure can be provided on the second LED chip 3 of the embodiment, and the light reflecting structure includes multiple Bragg reflection layers. The provision of the Bragg reflection layers is conducive to further improving the uniform light emission of the second LED chip 3.

[0044] The embodiment also discloses a high-contrast backlight module, which includes the above LED backlight source, a cavity 11 for accommodating the LED backlight source, a reflective film 12, a driving IC 13, an element 14, and a light conversion assembly; the LED backlight source, the reflective film 12, the driving IC 13, and the element 14 are all arranged in the cavity 11; the light conversion assembly is arranged at the opening of the cavity 11, and the light conversion assembly includes a diffusion plate 10, a light conversion layer 9, and an optical film layer 8 arranged in sequence in the light emitting direction.

[0045] Embodiment 2

[0046] The difference between the embodiment and the embodiment 1 is that:

[0047] See Figures 7-8The LED backlight source of the embodiment comprises a plurality of double-core point light sources 6 and a plurality of single-core point light sources 7, and the double-core point light sources 6 and the single-core point light sources 7 are arranged alternately.

[0048] Further, the LED chip of the single-core point light source 7 has a light-emitting angle of 170° and a Bragg reflection layer on the surface.

[0049] Further, the first LED chip 2 of the double-core point light source 6 has a light-emitting angle of 123°, and the second LED chip 3 has a light-emitting angle of 130°.

[0050] The optical layer 4 of the LED backlight source of the embodiment is composed of one layer of resin.

[0051] Embodiment 3

[0052] The difference between the embodiment and the embodiment 2 is that:

[0053] Referring to Figures 9-10 The LED backlight source of the embodiment comprises a plurality of double-core point light sources 6 and a plurality of single-core point light sources 7, and the double-core point light sources 6 and the single-core point light sources 7 are arranged alternately.

[0054] Further, the LED chip of the single-core point light source 7 has a light-emitting angle of 155° and a Bragg reflection layer on the surface.

[0055] Further, the first LED chip 2 of the double-core point light source 6 has a light-emitting angle of 129°, and the second LED chip 3 has a light-emitting angle of 160°.

[0056] The LED backlight source of the embodiment comprises a plurality of double-core point light sources 6 and a plurality of single-core point light sources 7, and the double-core point light sources 6 and the single-core point light sources 7 are arranged alternately.

[0057] The above description is only the preferred embodiment of the present application, and does not limit the present application in any form. Any modification, equivalent change and modification of the above embodiment according to the technical essence of the present application, without departing from the technical solution of the present application, still belongs to the scope of the technical solution of the present application.

Claims

1. An LED backlight, characterized in that, It includes a printed circuit board and an LED array; the LED array includes at least two point light sources, which are arranged in an array on the printed circuit board, and each point light source includes an LED chip, a connection layer and an optical layer; In the LED array, at least one of the point light sources is a dual-core point light source, which includes two LED chips: a first LED chip for improving dynamic dimming effect and a second LED chip for ensuring uniform light emission; the emission angle of the first LED chip is smaller than that of the second LED chip, and the first LED chip and the second LED chip can be controlled independently. The light rays from the first LED chips of two adjacent dual-core point light sources do not overlap; The second LED chip has a reflective structure, which includes multiple Bragg reflective layers; The surface of the first LED chip is sequentially covered with a light-transmitting layer and a reflective layer.

2. The LED backlight according to claim 1, characterized in that, The first LED chip has a light-emitting angle of 100°-125°.

3. The LED backlight according to claim 1, characterized in that, The second LED chip has a light-emitting angle of 130°-170°.

4. The LED backlight according to claim 1, characterized in that, The optical layer has two layers.

5. The LED backlight according to any one of claims 1-4, characterized in that, In the LED array, all the point light sources are dual-core point light sources.

6. The LED backlight according to any one of claims 1-4, characterized in that, The LED array includes multiple dual-core point light sources and multiple single-core point light sources; the dual-core point light sources and the single-core point light sources are arranged in an array with intervals.

7. The LED backlight according to any one of claims 1-4, characterized in that, The LED array includes multiple dual-core point light sources and multiple single-core point light sources; the multiple dual-core point light sources and multiple single-core point light sources are arranged in an array on the printed circuit board in a column or row interval.

8. A high-contrast backlight module, characterized in that, The device includes an LED backlight source as described in any one of claims 1-7, a cavity (11) for accommodating the LED backlight source, a reflective film (12), a driving IC (13), an element (14), and a light conversion assembly; the LED backlight source, the reflective film (12), the driving IC (13), and the element (14) are all disposed within the cavity (11); the light conversion assembly is disposed at the opening of the cavity (11), and the light conversion assembly includes a diffuser plate (8), a light conversion layer (9), and an optical film layer (10) arranged sequentially along the light emission direction.

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