Backlight module

Abstract

The utility model discloses a backlight module, which relates to the technical field of display, and comprises a substrate and a plurality of light-emitting devices arranged on the substrate, the plurality of light-emitting devices are divided into a plurality of groups of light-emitting areas, and any light-emitting area comprises four light-emitting devices arranged in an array; the four light-emitting devices in any light-emitting area are provided with more than two placement poses; the distance between any two adjacent light-emitting devices in the light-emitting area is d, and d meets a formula shown in the specification; wherein d is the distance between two adjacent light-emitting devices, k is an empirical coefficient, the value range of k is 0.75-1.25, h is the distance between the light guide plate and the substrate, and theta is the half-peak light-emitting angle of the light-emitting devices. By adjusting the distance between the LED devices and adjusting the direction arrangement of the devices, color cast areas of all the light-emitting areas of the backlight module are overlapped, the light mixing effect of the light-emitting areas is improved, and therefore the display effect of the backlight module is improved.

Description

Technical Field

[0001] This utility model relates to the field of display technology, specifically to a backlight module. Background Technology

[0002] In micro-pitch LED displays and direct-view lighting applications, the display screen is mounted on a substrate using LED devices, enabling the LED devices to meet the display requirements of the backlight module. Because conventional light-emitting devices internally encapsulate three types of chips—red, green, and blue—their spatial positions are fixed, and the overall structure of the light-emitting device lacks central symmetry, slight differences in luminous intensity distribution in different directions result in "inherent micro-color shift." In traditional PCB design, for ease of surface mount production and orientation identification, all LED devices are typically arranged in a uniform direction. For the backlight module's light-emitting device layout design, this unidirectional arrangement causes the directional color shift of each device to accumulate and amplify along the same direction in the macroscopic image, forming light spots and stripes when the light is emitted from the display screen, thus affecting the color mixing display effect of the backlight module. Utility Model Content

[0003] The purpose of this utility model is to overcome the shortcomings of the prior art. This utility model provides a backlight module that, by adjusting the spacing and orientation of the LED devices, makes each light-emitting area of ​​the backlight module form a color-shifting area, and improves the light mixing effect of the light-emitting areas by overlapping the color-shifting areas between the light-emitting areas, thereby improving the display effect of the backlight module.

[0004] This utility model provides a backlight module, which includes: a substrate, a plurality of light-emitting devices disposed on the substrate, the plurality of light-emitting devices being divided into a plurality of light-emitting regions, and any one of the light-emitting regions including four light-emitting devices arranged in an array;

[0005] The four light-emitting devices within any one of the light-emitting areas are arranged in two or more placement postures;

[0006] The distance between any two adjacent light-emitting devices within the light-emitting area is d, and d satisfies the formula:

[0007] ;

[0008] Where d is the spacing between two adjacent light-emitting devices, k is an empirical coefficient with a value range of 0.75 to 1.25, h is the distance between the light guide plate and the substrate, and θ is the half-peak emission angle of the light-emitting device.

[0009] Furthermore, the backlight module is provided with a light guide plate, which covers the light emission direction of the light-emitting device.

[0010] Furthermore, the four light-emitting devices in the light-emitting area are either connected in series in a single-circuit structure or connected in parallel in a dual-circuit structure.

[0011] Furthermore, the edge of any of the light-emitting regions is formed with several color-biased areas, and an overlapping area is formed within the color-biased areas of any two adjacent light-emitting regions.

[0012] Furthermore, in the directions from left to right and from top to bottom, the deflection angles of the four light-emitting devices in the light-emitting area are 0°, 180°, 0°, and 180°, respectively.

[0013] Furthermore, several color-shifting areas at the edge of the luminescent region are centrally symmetrically distributed.

[0014] Furthermore, in the directions from left to right and from top to bottom, the deflection angles of the four light-emitting devices in the light-emitting area are 0°, 180°, 180°, and 0°, respectively.

[0015] Furthermore, several color-shifting areas at the edge of the luminescent area are arranged radially.

[0016] Furthermore, in the directions from left to right and from top to bottom, the deflection angles of the four light-emitting devices in the light-emitting area are 0°, 90°, 90°, and 0°, respectively.

[0017] Furthermore, a red-biased area is formed in the upper left corner of the light-emitting area, and a blue-biased area is formed in the lower right corner of the light-emitting area.

[0018] Furthermore, in the directions from left to right and from top to bottom, the deflection angles of the four light-emitting devices in the light-emitting area are 0°, 90°, 270°, and 180°, respectively.

[0019] Furthermore, the edge region of the light-emitting area forms a blue-purple color bias area, and the corner region of the light-emitting area forms a green color bias area.

[0020] This utility model provides a backlight module that, by adjusting the spacing and orientation of the LED devices, creates color-shifting areas in each light-emitting region of the backlight module. Furthermore, the overlapping of these color-shifting areas enhances the light mixing effect of the light-emitting regions, thereby improving the display performance of the backlight module. Attached Figure Description

[0021] Figure 1 This is a side view of the backlight module in an embodiment of this utility model;

[0022] Figure 2This is a schematic diagram of the first arrangement structure of the light-emitting devices in the backlight module in this embodiment of the present invention;

[0023] Figure 3 This is a schematic diagram of the second arrangement structure of the light-emitting devices in the backlight module in this embodiment of the present invention;

[0024] Figure 4 This is a schematic diagram of the third arrangement structure of the light-emitting devices in the backlight module in this embodiment of the present invention;

[0025] Figure 5 This is a schematic diagram of the fourth arrangement structure of the light-emitting devices in the backlight module in this embodiment of the present invention. Detailed Implementation

[0026] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of the present utility model.

[0027] Example 1:

[0028] Please refer to Figures 1 to 5 This utility model provides a backlight module, which includes: a substrate 1, a plurality of light-emitting devices 2 disposed on the substrate 1, the plurality of light-emitting devices 2 being divided into a plurality of light-emitting areas 10, any one of the light-emitting areas 10 including four light-emitting devices 2 arranged in an array, the substrate 1 being provided with a circuit layer, and the light-emitting devices 2 being mounted on the corresponding pad positions of the circuit layer by soldering, so that the plurality of light-emitting devices 2 can meet the display requirements of the backlight module.

[0029] The four light-emitting devices 2 in any one of the light-emitting areas 10 are provided with two or more placement postures. That is, the light-emitting devices 2 in the light-emitting area 10 adjust the placement posture of the devices according to the actual installation requirements, and the posture adjustment of the light-emitting devices 2 is set by the deflection control of the light-emitting devices 2.

[0030] Specifically, the light-emitting device 2 includes a red light chip 21, a green light chip 22, and a blue light chip 23. The light-emitting device 2 can adopt an independent pad design. With the independent pad design, the working current of each string of red light chips 21, green light chips 22, and blue light chips 23 on the lamp board can be controlled individually, thereby achieving the adjustment of the color point. By controlling the working current of each string of red light chips 21, green light chips 22, and blue light chips 23 individually, the ratio of red light, blue light, and green light radiance of the light-emitting device 2 can be adjusted to a ratio range of (3~5:4~6:4~6), thereby achieving the adjustment requirement of the white light color point within the range of CIEx:0.18-0.35 and y:0.18-0.35.

[0031] The distance between any two adjacent light-emitting devices 2 within the light-emitting region 10 is d, and d satisfies the formula:

[0032] ;

[0033] Where d is the distance between two adjacent light-emitting devices 2, k is an empirical coefficient, the value of k ranges from 0.75 to 1.25, and is set according to the actual arrangement of light-emitting devices 2 in the backlight module and the installation and operation experience of the staff, h is the distance between the light guide plate 3 and the substrate 1, and θ is the half-peak emission angle of the light-emitting device 2, that is, the emission angle when the light intensity of the light-emitting device 2 drops to 50% of the peak value.

[0034] Furthermore, by setting This avoids gaps between the light-emitting areas of two adjacent light-emitting devices 2, thereby ensuring that the backlight module has a good light output display effect.

[0035] Specifically, the empirical coefficient k depends on the thickness and arrangement of the optical film, and is set according to the actual backlight module scheme. The empirical coefficient k ranges from 0.75 to 1.25, which can cover the setting requirements of light-emitting displays using traditional optical films. θ and h are known values. Referring to the attached diagram, based on the tangent function of a right triangle, we can obtain:

[0036] ;

[0037] After conversion, we get:

[0038] ;

[0039] After adding the empirical coefficient, we can obtain:

[0040] ;

[0041] Among them, the half-peak emission angle is a commonly used parameter in the industry to evaluate the emission angle of LEDs. It is the angle corresponding to the light-emitting device 2 of the backlight module at 50% maximum brightness. The spacing d calculated from this angle makes the arrangement of the two light-emitting devices 2 the best display effect, so as to meet the light output display requirements of the backlight module.

[0042] h is the distance from the light guide plate 3 to the substrate 1, i.e., the optical distance OD value of the backlight module. The light emitted by the light-emitting device 2 is mixed within the optical distance to achieve a good light mixing display effect. The relationship between the optical distance and the spacing d between two adjacent light-emitting devices 2 can be referred to the attached figure. The spacing d can be accurately calculated using the correspondence of trigonometric functions. The spacing d between two adjacent light-emitting devices is designed by combining the emission angle and the optical distance with trigonometric functions, so that the arrangement of the light-emitting devices 2 in the backlight module can meet the light emission display requirements of the backlight module, thus ensuring that the backlight module has a good light emission display effect.

[0043] Furthermore, by adjusting the arrangement spacing of two adjacent light-emitting devices 2 within the light-emitting area 10 of the backlight module, the problem of one side of the light emission effect of a single light-emitting device 2 being reddish and the other side being bluish due to the red light chip 21 and the blue light chip 23 not being at the same level in the optical center can be improved. By adjusting the spacing between two adjacent light-emitting devices 2, the color deviation of the light emitted by the two adjacent light-emitting devices 2 on the light guide plate 3 can be neutralized, thereby achieving a good and uniform light emission effect.

[0044] Specifically, the backlight module is provided with a light guide plate 3, which covers the light emission direction of the light-emitting device 2. The light guide plate 3 is used to adjust the light emission efficiency of the light-emitting device 2 in the backlight module, improve the light emission uniformity of the backlight module, and thus improve the light emission display effect of the backlight module.

[0045] For details, please refer to Figure 3 The four light-emitting devices 2 in the light-emitting area 10 can be connected in series with a single circuit structure. Through the cascading connection, the four light-emitting devices 2 in a single light-emitting area 10 can be controlled to light up synchronously, so as to adjust the display effect of several light-emitting areas 10 of the backlight module according to the actual display requirements.

[0046] For further details, please refer to... Figure 2 The four light-emitting devices 2 in the light-emitting area 10 can also be a dual-circuit structure arranged in parallel. By connecting several light-emitting devices 2 of the backlight module in series in a row-like manner, and forming a parallel connection between each row, the lighting control of each light-emitting device 2 of the backlight module can be realized to meet the display effect of the backlight module.

[0047] Furthermore, the edge of any of the light-emitting areas 10 is formed with several color-shifting areas, and an overlapping area is formed in the color-shifting areas of any two adjacent light-emitting areas 10. By overlapping and mixing the color-shifting areas of multiple light-emitting areas 10, the backlight module can achieve a uniform white light display effect.

[0048] The backlight module provided in this embodiment improves the light mixing effect of a single light-emitting device 2 by adjusting the arrangement spacing of adjacent light-emitting devices 2 in the light-emitting area 10, and achieves a uniform white light display effect of the backlight module by combining the superposition of the color-shifting areas of multiple light-emitting areas 10.

[0049] Example 2:

[0050] Please refer to Figure 2 In this embodiment, the backlight module has several light-emitting devices 2 arranged alternately at 0° and 180° positions. From left to right and from top to bottom, the deflection angles of the four light-emitting devices 2 within the light-emitting area 10 are 0°, 180°, 0°, and 180°, respectively. This means the four light-emitting devices 2 within the light-emitting area 10 are arranged alternately at 0° and 180°. Compared to the traditional single-direction arrangement, the several color-shifting areas at the edge of the light-emitting area 10 are centrally symmetrically distributed, and the color distribution around the light source of the light-emitting area 10 is centrally symmetrical. The light emitted from the left and right ends of the light-emitting area 10 is white light. When the several light-emitting devices 2 are arranged alternately at 0° and 180° positions, the different colors of light from each light-emitting area 10 mix together, thereby forming a uniform white light emission effect on the light-emitting surface of the backlight module.

[0051] Example 3:

[0052] Please refer to Figure 3 In this embodiment, the backlight module's light-emitting devices 2 are arranged alternately in groups of 0° and 180° at the top and 180° and 0° at the bottom. From left to right and from top to bottom, the deflection angles of the four light-emitting devices 2 within the light-emitting area 10 are 0°, 180°, 180°, and 0°, respectively. Compared to the traditional single-direction arrangement, the several color-shifting areas at the edge of the light-emitting area 10 are arranged radially, and the light emitted from the light-emitting area 10 has a greenish tint in the corner areas and a purplish tint at the edges. When multiple light-emitting devices 2 are arranged in this manner, different colors of light mix, resulting in a better light mixing effect.

[0053] Example 4:

[0054] Please refer to Figure 4In this embodiment, the backlight module's light-emitting devices 2 are arranged alternately in groups of 0° and 90° at the top and 90° and 0° at the bottom. The deflection angles of the four light-emitting devices 2 within the light-emitting area 10 are 0°, 90°, 90°, and 0°, respectively, from left to right and from top to bottom. Compared to the traditional single-direction arrangement, a red-biased area is formed in the upper left corner of the light-emitting area 10, and a blue-biased area is formed in the lower right corner. The red-biased area in the upper left part and the blue-biased area in the lower right part of the multiple light-emitting areas 10 of the backlight module mix, resulting in near-white light around the light source, thus improving the white light mixing effect of the backlight module.

[0055] Example 5:

[0056] Please refer to Figure 4 In this embodiment, the backlight module's light-emitting devices 2 are arranged alternately in groups of 0° and 90° at the top and 270° and 180° at the bottom. The deflection angles of the four light-emitting devices 2 within the light-emitting area 10 are 0°, 90°, 270°, and 180°, respectively, from left to right and from top to bottom. The edge area of ​​the light-emitting area 10 forms a blue-purple color bias, while the corner area forms a green color bias. That is, the light emitted from the corner area of ​​the light-emitting area 10 is greenish, while the light emitted from the edge area is purplish-blue. The light mixing effect of the backlight module's light-emitting area 10 is significantly better than the traditional single-direction arrangement. Furthermore, the color distribution around the light source of the light-emitting area 10 is radial. Through the cooperation of multiple light-emitting devices 2 in various positions, the light from multiple directions in the light-emitting area 10 is fully mixed, helping to reduce the problem of different light colors at different locations.

[0057] This embodiment of the invention solves the problem of regular uneven light mixing caused by inherent slight color shift at the physical level by adjusting the arrangement of several light-emitting devices 2 in the backlight module. By starting with the optical layout of the backlight module devices, the color shift of the light-emitting area 10 of the backlight module is neutralized through structural arrangement design. It eliminates the need to increase the light mixing distance or use strong diffusion elements, which is conducive to achieving an ultra-thin design of the backlight module. At the same time, it avoids additional optical material costs and improves the cost-effectiveness of the backlight module with high uniformity light mixing effect.

[0058] Furthermore, the embodiments of this utility model have been described in detail above. Specific examples have been used to illustrate the principles and implementation methods of this utility model. The description of the above embodiments is only for the purpose of helping to understand the method and core ideas of this utility model. At the same time, for those skilled in the art, there will be changes in the specific implementation methods and application scope based on the ideas of this utility model. Therefore, the content of this specification should not be construed as a limitation of this utility model.

Claims

1. A backlight module, characterized in that, The backlight module includes: a substrate, a plurality of light-emitting devices disposed on the substrate, the plurality of light-emitting devices being divided into a plurality of light-emitting regions, and any one of the light-emitting regions including four light-emitting devices arranged in an array; The four light-emitting devices within any one of the light-emitting areas are arranged in two or more placement postures; The distance between any two adjacent light-emitting devices within the light-emitting area is d, and d satisfies the formula: ； Where d is the spacing between two adjacent light-emitting devices, k is an empirical coefficient with a value range of 0.75 to 1.25, h is the distance between the light guide plate and the substrate, and θ is the half-peak emission angle of the light-emitting device.

2. The backlight module as described in claim 1, characterized in that, The backlight module is provided with a light guide plate, which covers the light emission direction of the light-emitting device.

3. The backlight module as described in claim 1, characterized in that, The four light-emitting devices in the light-emitting area are either connected in series in a single-circuit structure, or the four light-emitting devices in the light-emitting area are connected in parallel in a dual-circuit structure.

4. The backlight module as described in claim 1, characterized in that, The edge of any of the light-emitting regions has several color-shifting areas, and an overlapping area is formed within the color-shifting areas of any two adjacent light-emitting regions.

5. The backlight module as described in claim 4, characterized in that, The deflection angles of the four light-emitting devices in the light-emitting area, from left to right and from top to bottom, are 0°, 180°, 0°, and 180°, respectively.

6. The backlight module as described in claim 5, characterized in that, Several color-shifting areas at the edge of the luminescent area are centrally symmetrically distributed.

7. The backlight module as described in claim 4, characterized in that, The deflection angles of the four light-emitting devices in the light-emitting area, from left to right and from top to bottom, are 0°, 180°, 180°, and 0°, respectively.

8. The backlight module as described in claim 7, characterized in that, Several color-shifting areas at the edge of the luminescent area are arranged radially.

9. The backlight module as described in claim 4, characterized in that, The deflection angles of the four light-emitting devices in the light-emitting area, from left to right and from top to bottom, are 0°, 90°, 90°, and 0°, respectively.

10. The backlight module as described in claim 9, characterized in that, A red-biased area is formed in the upper left corner of the luminous area, and a blue-biased area is formed in the lower right corner of the luminous area.

11. The backlight module as described in claim 4, characterized in that, The deflection angles of the four light-emitting devices in the light-emitting area, from left to right and from top to bottom, are 0°, 90°, 270°, and 180°, respectively.

12. The backlight module as described in claim 11, characterized in that, The edge area of ​​the luminescent area forms a blue-purple color bias area, and the corner area of ​​the luminescent area forms a green color bias area.

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