Backlight module and display device

Abstract

The utility model relates to a backlight module and display device. A kind of backlight module, include a lamp plate, a diffusion plate and a diffusion pattern. Lamp plate is equipped with multiple light source units, each the light source unit includes a light source element, each the light source element defines two element long sides apart. Diffusion plate is spaced apart with the lamp plate. Diffusion pattern is located between the diffusion plate and the lamp plate, and the diffusion pattern includes multiple main patterns and the one-to-one correspondence of the light source unit, and each the main pattern includes mutually perpendicular one main pattern long axis and one main pattern short axis, and the main pattern short axis of the main pattern extends outward from the center of the main pattern long axis, and the projection of the main pattern long axis of each the main pattern to each the light source unit is located between the two element long sides of each the light source element. The utility model further provides a display device and the layout method of diffusion pattern.

Description

Technical Field

[0001] This utility model relates to a backlight module, and more precisely, to a backlight module that can provide a uniform surface light source and reduce the generation of grid-like phenomena, as well as a display module including the backlight module and a method for arranging diffusion patterns in the backlight module. Background Technology

[0002] With the continuous development of display technology, the backlight module, as a core component of LCD displays, directly affects display quality through its optical performance. Especially with the trend towards thinner and lighter designs, modern backlight modules face numerous technical challenges.

[0003] Please see Figure 1 The display shows three different backlight modules. Multiple light source elements 31A are respectively arranged on the lamp panel 33A of the aforementioned three different backlight modules, wherein these light source elements 31A are light sources with the same diffusion angle; the lamp panels 33A and the diffusion plates 20A are respectively spaced by optical distances OD1, OD2, and OD3, where optical distances OD1 and OD3 are equal, and optical distance OD2 is smaller than both optical distances OD1 and OD3.

[0004] like Figure 1 The upper backlight module is a conventional ideal backlight module. When the optical distance OD1 is long enough and the density of the light source elements 31A is sufficient, the optical paths between adjacent light source elements 31A fully overlap and intersect, forming a good light mixing effect without obvious grid phenomenon.

[0005] Figure 1 The middle backlight module showcases a thinner and lighter design with reduced thickness. Due to its shorter optical distance OD2, although the density of its light source element 31A remains unchanged, there is still insufficient overlap of the optical path between adjacent light source elements 31A, resulting in a grid-like phenomenon.

[0006] Figure 1 The backlight module below showcases another lightweight design. Although the optical distance OD3 is the same as OD1, the spacing and density between adjacent light source elements 31A are larger. This arrangement can lead to insufficient optical path overlap, resulting in a grid-like effect. Therefore, in addition to Figure 1 The backlight module above, and other backlight modules, tend to form a distinct light and dark grid distribution on the light-emitting surface of the diffuser plate 20A.

[0007] In conventional technology, a method to improve the grid mura phenomenon is to print halftone dots on a diffuser plate to adjust the light distribution. Specifically, the density of the halftone dots is higher in the area directly above the LED and lower in the area around the LED, using the density difference to balance the contrast between light and dark.

[0008] However, relying solely on dot density to improve the grid phenomenon has obvious technical limitations: even if the dot density is increased to the upper limit, it is difficult to completely and effectively suppress the strongest central bright spot directly above the LED, so the grid phenomenon cannot be completely eliminated, and the improvement in overall brightness uniformity is also quite limited.

[0009] Therefore, the industry urgently needs a new technical solution that can more effectively suppress the central bright spot of LED light sources, improve the luminance of dark areas, and adapt to the light field characteristics of different types of LEDs and different optical distance designs, thereby fundamentally solving the grid phenomenon problem of thin direct-lit backlight modules. Utility Model Content

[0010] To achieve the above objectives, this utility model provides a backlight module comprising: a lamp panel, a diffuser plate, and a diffuser pattern. The lamp panel has multiple light source units, each light source unit including a light source element, and each light source element defining two long sides spaced apart. The diffuser plate is spaced apart from the lamp panel. The diffuser pattern is located between the diffuser plate and the lamp panel, and the diffuser pattern includes multiple main patterns corresponding one-to-one with the light source units. Each main pattern includes a major axis and a minor axis that are perpendicular to each other. The minor axis of the main pattern extends outward from the center of the major axis, and the projection of the major axis of each main pattern toward each light source unit is located between the two long sides of each light source element.

[0011] Preferably, the length of the major axis of the main graphic is equal to the length of the long side of the light source element, and the length of the minor axis of the main graphic is the length of the major axis of the main graphic multiplied by a coefficient less than 1.

[0012] Preferably, the value of the coefficient is inversely proportional to an optical distance between the lamp plate and the diffuser plate, the optical distance being in the range of 1.5 mm to 5 mm.

[0013] Preferably, when the unit of the optical distance is millimeters (mm), the value of the coefficient multiplied by the optical distance is between 1 and 2.3.

[0014] Preferably, each of the light source units has the light source element and a sealing adhesive, the sealing adhesive covering the light source element, the length of the major axis of the major pattern being equal to the length of the long side of the sealing adhesive, and the length of the minor axis of the major pattern being equal to the length of the short side of the sealing adhesive.

[0015] Preferably, the diffusion pattern is directly disposed on a lower surface of the diffusion plate.

[0016] Preferably, the diffusion pattern is arranged on a membrane located between the diffusion plate and the light source units.

[0017] Preferably, the diffusion pattern comprises multiple dots arranged around the main patterns.

[0018] Preferably, these outlets are arranged at equal intervals.

[0019] Preferably, each of the main graphics has at least one reference point for at least a portion of the dots to be arranged at equal intervals, the at least one reference point being located at the center of each main graphic, on the minor axis of the main graphic, or on the major axis of the main graphic.

[0020] The present invention also provides a display device, comprising the aforementioned backlight module; and a display panel disposed on a light-emitting surface of the backlight module.

[0021] This utility model also provides a method for arranging a diffusion pattern in a backlight module as described in any of the above embodiments. The method includes: providing the diffusion pattern between the diffusion plate and the lamp plate, wherein the diffusion pattern includes a plurality of main patterns at positions corresponding to each of the light source units.

[0022] Preferably, the step of providing the diffusion pattern further includes the placement of multiple dots around the main patterns.

[0023] Preferably, the step of providing the diffusion pattern further includes: determining the lengths of the major axis and the minor axis of the main pattern based on whether each of the light source units has a sealant; if each of the light source units does not have the sealant, the length of the minor axis is set to the length of the major axis multiplied by a coefficient less than 1; if each of the light source units has the sealant, the lengths of the major axis and the minor axis are respectively set to the length of a long side and a short side corresponding to the sealant. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of a conventional technology diffuser, light source, and the formation of a grid.

[0025] Figure 2 This is a side view of the backlight module in the first embodiment.

[0026] Figure 3 It is along Figure 2 The diagram showing the cross pattern of the diffuser plate and the distribution of the light source in the first embodiment, as shown by line 3-3.

[0027] Figure 4 This is a side view of the backlight module in the second embodiment.

[0028] Figure 5 It is along Figure 4The second embodiment, as shown by line 5-5, is a schematic diagram of the diffuser plate pattern and the distribution of the light source.

[0029] Figure 6 This is a side view of the backlight module in the third embodiment.

[0030] Figure 7 It is along Figure 6 The diagram showing the distribution of the diffusion plate and diffusion pattern in the third embodiment, as captured by line 7-7.

[0031] Figure 8 This is a side view of the backlight module in the fourth embodiment.

[0032] Figure 9 This is a side view of the display device. Detailed Implementation

[0033] The following description is based on the light emission direction of the light-emitting surface as upward, in order to conform to the common understanding of those skilled in the art.

[0034] Please see Figure 2 and Figure 3 The diagram illustrates the arrangement of the components in the first embodiment of the backlight module 100. The backlight module 100 includes a lamp panel 33, multiple light source units 30, a diffuser plate 20, and a diffuser pattern 40. The lamp panel 33 is provided with multiple light source units 30, each light source unit 30 includes a light source element 31, and each light source element 31 defines two long sides 31L that are spaced apart.

[0035] In this embodiment, the diffuser plate 20 and the lamp plate 33 are spaced apart, and the distance between the diffuser plate 20 and the lamp plate 33 is the optical distance OD5. This optical distance OD5 is a key parameter affecting the light mixing effect. The diffusion pattern 40 is located between the diffuser plate 20 and the lamp plate 33, and the diffusion pattern 40 includes multiple main patterns 41 that correspond one-to-one with the light source unit 30. Each main pattern 41 includes a major axis 41L and a minor axis 41S that are perpendicular to each other. The minor axis 41S of the main pattern 41 extends outward from the center of the major axis 41L. The projection of the major axis 41L of each main pattern 41 toward each light source unit 30 is located between the two long sides 31L of each light source element 31.

[0036] In this configuration, the light projected by the light source element 31 toward the diffuser plate 20 can produce at least three light paths.

[0037] In the light path L0, the projected light from the light source element 31 is projected outwards and does not pass through the location where the diffusion pattern 40 is laid out, so there is no reflection.

[0038] In the light path L1, the projected light from the light source element 31 shines directly upwards, and a portion of the light passes through the diffusion pattern 40.

[0039] In the light path L2, the projected light from the light source element 31 shines directly upwards. In addition to forming part of the light in the light path L1, another part of the light from the light source element 31 is projected toward the position where the diffusion pattern 40 is arranged. The main pattern 41 of the diffusion pattern 40 effectively reflects the projected light toward the lamp panel 33, and the lamp panel 33 then reflects the light toward the outer area, thus diffusing the light distribution.

[0040] The structure of this backlight module can balance the brightness contrast between adjacent light source units 30, eliminate the grid phenomenon, and improve the uniformity of the light-emitting surface.

[0041] In one embodiment, the main graphic 41 is cross-shaped, with the major axis 41L forming the long side of the cross and the minor axis 41S forming the short side. Besides the cross shape, the main graphic 41 can also adopt other shapes with mutually perpendicular major axes 41L and minor axes 41S, such as a T-shape or an L-shape. The positional relationship between the major axis 41L and minor axis 41S of the main graphic 41 can be adjusted according to the uniformity of the overall surface light source, thus achieving the effect of shielding the light above the light source element 31 and guiding the light to reflect and diffuse outwards.

[0042] In one embodiment, the light source element 31 is an LED that is not encapsulated in the lamp board 33, and the length settings of the major axis 41L and the minor axis 41S of the main pattern 41 are defined as follows.

[0043] Under these conditions, the length of the major axis 41L of the main pattern 41 is equal to the length of the long side 31L of the light source element 31, and the length of the minor axis 41S of the main pattern 41 is the length of the major axis 41L of the main pattern 41 multiplied by a coefficient. Since the aforementioned coefficient is less than 1, the length of the minor axis 41S of the main pattern 41 is less than the length of the major axis 41L of the main pattern 41. In other words, the major axis 41L of the main pattern 41 completely covers the long side direction of the light source element 31, while the length of the minor axis 41S is adjusted according to the coefficient to ensure a balance between the shading effect and the light reflection and diffusion effect.

[0044] Under this design, since the length of the minor axis 41S of the main graphic 41 is defined based on the length of the major axis 41L of the main graphic 41, the length of the minor axis 41S of the main graphic 41 is not specifically related to the length of the short side 31S of the light source element 31. Therefore, the length of the minor axis 41S of the main graphic 41 can be greater than, less than or equal to the length of the short side 31S of the light source element 31.

[0045] The coefficient is inversely proportional to the optical distance OD5 between the lamp plate 33 and the diffuser plate 20. Generally, the optical distance OD5 between the lamp plate 33 and the diffuser plate 20 ranges from 1.5mm to 5mm. When the optical distance OD5 is large, the light has a large diffusion range, and the light overlap between adjacent light source units 30 is sufficient. In this case, the coefficient can be set to a smaller value so that the minor axis 41S of the main pattern is relatively short, thus achieving the effect of eliminating the grid phenomenon. When the optical distance OD5 is small, the light diffusion range is small, and the light overlap between adjacent light source units 30 is insufficient. In this case, the coefficient needs to be set to a larger value so that the minor axis 41S of the main pattern is relatively long to provide sufficient shielding and reflection diffusion effects. That is to say, the size of the main pattern 41 is adjusted according to the coefficient and the value of the optical distance OD5 to ensure good uniformity under different optical distance OD5 conditions.

[0046] In one embodiment, when the optical distance OD5 is measured in millimeters (mm), the value of the coefficient multiplied by the optical distance OD5 is between 1 and 2.3. For a specific example, when the optical distance OD5 is 1.5 mm, the coefficient is 0.76, and the value multiplied by the coefficient is 1.14. When the optical distance OD5 is 5 mm, the coefficient is 0.41, and the value multiplied by the coefficient is 2.05. This aforementioned range ensures that the minor axis 41S of the main graphic 41 has an appropriate length under different optical distance OD5 conditions, achieving optimal light diffusion and uniformity, allowing the backlight module 100 to adapt to different thinning requirements.

[0047] Please see Figure 4 and Figure 5 The diagram illustrates the arrangement of components in a second embodiment of the backlight module 100. The backlight module 100 includes a lamp panel 33, multiple light source units 30, a diffuser plate 20, and a diffuser pattern 40. The diffuser pattern 40 includes multiple main patterns 41 that correspond one-to-one with the light source units 30. In this embodiment, each light source unit 30 includes a light source element 31 and a sealant 32. The light source element 31 is covered and positioned on the lamp panel 33 by the sealant 32, and each light source element 31 defines two long sides 31L spaced apart. The sealant 32, in addition to protecting the light source element 31, also diffuses light. As a specific example, the boundaries of the sealant 32 on each light source element 31 are not connected.

[0048] The boundary of the sealant 32 is usually irregular in shape, but it is also arranged or extended to match the two long sides 31L and two short sides 31S of the light source element 31. When the light source unit 30 includes the sealant 32, this invention defines the range of the main pattern of the main pattern 41 by the range of the sealant 32. Each sealant 32 includes a long side 32L of the sealant relative to the long side 31L of the element and a short side 32S of the sealant relative to the short side 31S of the element. The length of the long axis 41L of the main pattern 41 is equal to the length of the long side 32L of the sealant 32, and the length of the short axis 41S of the main pattern 41 is equal to the length of the short side 32S of the sealant 32. By matching the outline of the main pattern 41 with the contour of the sealant 32, the most direct and precise shielding and shaping of the light source is achieved, ensuring that the projected light directly upward from the light source element 31 is effectively reflected towards the lamp panel 33 by the main pattern 41, achieving a light diffusion effect.

[0049] Please see Figure 6 and Figure 7 The diagram illustrates the arrangement of components in the third embodiment of the backlight module 100. In this embodiment, the backlight module 100 includes a lamp panel 33, a light source unit 30, a diffuser plate 20, and a diffuser pattern 40. The diffuser pattern 40 includes multiple main patterns 41 corresponding one-to-one with the light source unit 30, and multiple dots 42 surrounding these main patterns 41. Each main pattern 41 includes a major axis 41L and a minor axis 41S that are perpendicular to each other. The positions and dimensional correspondences of the light source element 31 and the main patterns 41 of the diffuser pattern 40 are the same in the third embodiment as in the first and second embodiments, and therefore will not be repeated. Furthermore, the diagram of this embodiment... Figure 7 Omit Figure 6 The outline of the light source unit 30 is shown to clearly identify the relationship between the components.

[0050] The dots 42 are arranged outward from the main graphic 41 to further diffuse the light towards the surrounding area of ​​the main graphic 41.

[0051] In this configuration, the light source element 31 can project light toward the diffuser plate 20 to generate two other light paths besides the three light paths mentioned above.

[0052] The light path L3 is projected from the light source element 31 toward the position where the diffusion pattern 40 is laid out. A portion of the projected light from the light source element 31 is reflected by the dots 42 and directed toward the lamp plate 33. The lamp plate 33 then projects the light toward the diffusion plate 20 to emit light.

[0053] Light path L4, the light source element 31 projects upward towards the main pattern 41 of the diffusion pattern 40, the light is reflected by the main pattern 41 and towards the lamp plate 33, the lamp plate 33 reflects the light towards the dot 42, the dot 42 reflects the light reflected from the lamp plate 33 again towards the lamp plate 33, the lamp plate 33 projects the light towards the diffusion plate 20 to emit light.

[0054] In this embodiment, the halftone dots 42 are arranged around the main graphic 41 to reflect some of the light from the periphery of the main graphic 41 and project it toward the light panel 33, which then reflects the light to a further outer area. As a specific example, the halftone dots 42 can be arranged based on the outer contour of the main graphic 41. The arrangement of the halftone dots 42 can further expand the light diffusion range, increase the brightness of the area between adjacent light source units 30, and improve the overall uniformity. The cooperation between the halftone dots 42 and the main graphic 41 jointly achieves the control of light distribution, making the brightness distribution of the light-emitting surface more uniform.

[0055] In one embodiment, the spacing between adjacent dots 42 can be designed to be equal, resulting in a more uniform and diffused light distribution. It is worth noting that the arrangement of the aforementioned adjacent dots 42 can be based on the main pattern 41, or it can be independent of the main pattern 41.

[0056] In one embodiment, multiple dots 42 are arranged at equal intervals. This equal-interval arrangement ensures that the dot 42 has a regular distribution of light blocking and diffusion effects, avoiding new brightness unevenness caused by uneven dot arrangement. It also ensures that the dot 42 provides a consistent diffusion effect throughout the entire diffuser plate 20, maintaining the uniformity of the light-emitting surface.

[0057] In one embodiment, the main graphic 41 has at least one reference point for at least a portion of the dots 42 to be arranged at equal intervals. For example, reference point S1 can be located at the center of the main graphic 41, reference point S2 can be located on the major axis 41L of the main graphic, or reference point S3 can be located on the minor axis 41S of the main graphic. Figure 5 In the example shown, the reference points include reference point S1 located at the intersection of the minor axis 41S and the major axis 41L of the main figure, reference point S2 located on the minor axis 41S of one side of the main figure, and reference point S3 located on the major axis 41L of one side of the main figure.

[0058] The dots 42 can be arranged in concentric circles at equal intervals from one of the reference points, or they can be arranged radially at equal intervals from one of the reference points. This arrangement makes the distribution of dots 42 symmetrical, which can evenly diffuse the light around the main pattern 41.

[0059] The outlines of the halftone dots 42 are designed to avoid connecting with the outlines of the main graphic 41 as much as possible, in order to prevent affecting the occlusion and diffusion effects of the main graphic 41, while also allowing some light to escape through these gaps. The purpose of this design is to avoid creating a dark area directly above the light source element 31, thus maintaining a consistent level of brightness. Equal spacing ensures that the halftone dots 42 provide consistent light control, further improving the uniformity of the illuminated surface.

[0060] In one embodiment, the diffusion pattern 40 is directly disposed on the lower surface 201 of the diffusion plate 20. This placement simplifies the process steps and reduces manufacturing costs. The diffusion pattern 40 is directly integrated with the diffusion plate 20, reducing assembly steps and improving production efficiency.

[0061] Please see Figure 8 The diagram illustrates the arrangement of components in the fourth embodiment of the backlight module 100. In this embodiment, the diffusion pattern 40 is disposed on the diaphragm 60, which is located between the diffuser plate 20 and the light source unit 30. This embodiment treats the diaphragm 60 as an independent optical element, allowing the diffusion pattern 40 to be pre-fabricated on the surface of the diaphragm 60 before it is installed between the diffuser plate 20 and the light source unit 30. This structure provides process flexibility; for example, when the diffusion pattern 40 needs to be replaced or adjusted, only the diaphragm 60 needs to be replaced without replacing the entire diffuser plate 20, reducing adjustment costs and improving process convenience.

[0062] In one embodiment, the diffusion pattern 40 can be printed on the lower surface 201 of the diffusion plate 20 or the film 60 using infrared (IR) curable ink or ultraviolet (UV) curable ink, and then cured by irradiation with infrared (IR) or ultraviolet (UV) light. Using infrared (IR) curable ink to create the diffusion pattern 40 is a simpler and more efficient process, offering a cost advantage; using ultraviolet (UV) curable ink provides faster curing and more stable ink adhesion, making it suitable for high-precision applications.

[0063] In one embodiment, the light source element 31 can be a light-emitting diode (LED), a direct-beam LED, or a chip-scale packaged LED (CSP LED). With the diffusion pattern 40 present in the aforementioned embodiment, even if the diffusion angle of the light source element 31 is small, the brightness contrast between adjacent light source units 30 can be balanced, the grid phenomenon can be eliminated, and the uniformity of the light-emitting surface can be improved.

[0064] Please see Figure 9This embodiment also discloses a display device comprising a backlight module 100 as described in any of the above embodiments and a display panel 200, wherein the display panel 200 is disposed on the light-emitting surface of the backlight module 100. The backlight module 100 provides a uniform surface light source without grid-like phenomena, so the image light formed after the light passes through the display panel 200 will also not have grid-like phenomena, thereby improving the display quality of the display device.

[0065] Please see Figure 2 This utility model further discloses a method for arranging a diffusion pattern 40. The arrangement method includes providing a diffusion pattern 40, which is located between a diffusion plate 20 and a lamp plate 33. The diffusion pattern 40 includes a plurality of main patterns 41, which are positioned corresponding to each light source element 31.

[0066] Please see Figure 3 and Figure 5 In one embodiment, the main graphic 41 includes a major axis 41L and a minor axis 41S that are perpendicular to each other. The projection of the major axis 41L of the main graphic 41 onto each light source element 31 is located between the two long sides 31L of each light source element 31. This arrangement method ensures that the main graphic 41 corresponds precisely to the light source element 31, achieving the best diffusion effect. In another embodiment, the arrangement method may further include determining the lengths of the major axis 41L and the minor axis 41S of the main graphic 41 based on whether each light source element 31 has a sealant 32. If each light source element 31 does not have a sealant 32, the length of the minor axis 41S of the main pattern is set to the length of the major axis 41L of the main pattern multiplied by a coefficient less than 1, the magnitude of which is inversely proportional to the optical distance OD5. If each light source element 31 has a sealant 32, the lengths of the major axis 41L and the minor axis 41S of the main pattern are set to the lengths of the long side 32L and the short side 32S of the sealant, respectively. This method allows for the selection of appropriate main pattern 41 dimensions based on the actual structure of the light source unit 30, ensuring that the diffusion pattern 40 performs optimally under different types of light source units 30.

[0067] The aforementioned judgment criteria are used to determine whether there is a correlation between the length of the major axis 41L and the length of the minor axis 41S of the major graphic 41. The specific lengths of the major axis 41L and the minor axis 41S of the major graphic are obtained by referring to the aforementioned implementation, and will not be repeated here.

[0068] Please see Figure 7In one embodiment, the arrangement method may further include providing multiple dots 42 arranged around the main graphic 41. The arrangement of dots 42 can further improve the diffusion range and uniformity of light, so that the light-emitting surface of the backlight module 100 has a more uniform brightness distribution. The arrangement positions of the multiple dots 42 can be referred to the aforementioned embodiment, and will not be repeated here.

[0069] In another embodiment of this utility model, the diffuser plate can be replaced with a diffuser sheet, and the diffuser patterns disposed on the diffuser sheet can achieve the same effect as those disposed on the diffuser plate.

[0070] In summary, based on the spirit of the aforementioned implementation, under the aforementioned settings, the brightness contrast between adjacent light source units 30 in the backlight module can be balanced, and the uniformity of the light-emitting surface can be improved. Therefore, light source units with high brightness and low diffusion angle can be used without producing a grid phenomenon.

[0071] The above description is merely a preferred embodiment of the present utility model and is not intended to limit the claims of the present utility model. Any equivalent modifications or alterations made by those skilled in the art to which this utility model pertains without departing from the spirit and scope of the present utility model should be included in the claims of the present utility model.

[0072] [Symbol Explanation] 100: Backlight Module 200: Display panel 20, 20A: Diffuser plates 201: Lower surface 30: Light source unit 31, 31A: Light source element 31L: Long side of component 31S: Component short side 32: Sealing 32L: Sealed long side 32S: Sealing short side 33, 33A: Light board 40: Diffusion Graphics 41: Main Graphics 41L: Main graphic long axis 41S: Main graphic short axis 42: Outlets 60: Membrane OD1, OD2, OD3, OD5: Optical distance L0, L1, L2, L3, L4: Optical path S1, S2, S3: Reference points.

Claims

1. A backlight module, characterized in that, Include: The light panel is provided with multiple light source units, each light source unit includes a light source element, and each light source element defines two long sides that are separated by a space. A diffuser plate is spaced apart from the light panel; A diffusion pattern is located between the diffusion plate and the lamp plate. The diffusion pattern includes multiple main patterns that correspond one-to-one with the multiple light source units. Each main pattern includes a major axis and a minor axis that are perpendicular to each other. The minor axis of the main pattern extends outward from the center of the major axis. The projection of the major axis of each main pattern toward each light source unit is located between the two long sides of each light source element.

2. The backlight module as described in claim 1, characterized in that, The length of the major axis of the main graphic is equal to the length of the long side of the light source element, and the length of the minor axis of the main graphic is the product of the length of the major axis of the main graphic and a coefficient less than 1.

3. The backlight module as described in claim 2, characterized in that, The value of this coefficient is inversely proportional to the optical distance between the lamp plate and the diffuser plate, which ranges from 1.5 mm to 5 mm.

4. The backlight module as described in claim 3, characterized in that, When the unit of optical distance is millimeters (mm), the value of the coefficient multiplied by the optical distance is between 1 and 2.

3.

5. The backlight module as described in claim 1, characterized in that, Each light source unit has a light source element and a sealant. The sealant covers the light source element. The length of the major axis of the main pattern is equal to the length of the long side of the sealant, and the length of the minor axis of the main pattern is equal to the length of the short side of the sealant.

6. The backlight module as described in claim 1, characterized in that, The diffusion pattern is directly applied to the lower surface of the diffusion plate.

7. The backlight module as described in claim 1, characterized in that, The diffusion pattern is arranged on a diaphragm, which is located between the diffusion plate and the plurality of light source units.

8. The backlight module as described in any one of claims 1 to 7, characterized in that, The diffusion pattern comprises multiple dots arranged around the multiple main patterns.

9. The backlight module as described in claim 8, characterized in that, The multiple network points are arranged at equal intervals.

10. The backlight module as described in claim 8, characterized in that, Each of the main graphics has at least one reference point for at least a portion of the multiple dots to be arranged at equal intervals. The at least one reference point is located at the center of each main graphic, on the minor axis of the main graphic, or on the major axis of the main graphic.

Images