Light Source Module

Abstract

The light source module includes a printed circuit board; a light source disposed on the printed circuit board; a first light guide layer disposed on the printed circuit board and accommodating the light source; and a second light guide layer disposed on top of the first light guide layer, wherein the material of the first light guide layer is different from the material of the second light guide layer, and the refractive index of the first light guide layer is greater than the refractive index of the second light guide layer.

Description

[Technical Field]

[0001] This embodiment relates to a light source module. [Background technology]

[0002] The following description merely provides background information for the present embodiment and is not intended to describe the prior art.

[0003] Light source modules that utilize various light sources used in electronic devices are realized by using a method that increases light efficiency by utilizing a light source appropriate for the characteristics of each electronic device.

[0004] Recently, light source modules used in such electronic devices can be applied to a variety of applications, such as backlight units applied to flat panel displays, interior lights used in indoor environments, and interior lighting installed inside automobiles, such as headlights, fog lights, back-up lights, sidelights, license plate lights, tail lights, brake lights, turn signals, hazard warning lights, etc.

[0005] Meanwhile, efforts to improve the luminous efficiency of LEDs are being made continuously from the chip to the package. For example, in the packaging process, efforts are being made to create a thermally stable structure by applying a relatively high current using materials with good heat dissipation efficiency such as heat sinks, and to increase light extraction efficiency through optimal design that takes into account the optical structure and characteristics of the package.

[0006] However, although a significant portion of these efforts have been successful to some extent at the laboratory level, there are considerable difficulties in applying them to actual manufacturing processes. Summary of the Invention [Problem to be solved by the invention]

[0007] This embodiment aims to provide a light source module with high light efficiency and capable of eliminating hot spots for a surface light source by improving the structure.

[0008] In addition, in order to eliminate hot spots of the LED, a separate layer is implemented, simplifying the structure from a structure in which multiple processes are applied, and simplifying the process, while at the same time providing a light source module with a uniform surface light source. [Means for solving the problem]

[0009] In one embodiment, the light source module includes: a printed circuit board; a light source disposed on the printed circuit board; a first light guide layer disposed on the printed circuit board and accommodating the light source; and a second light guide layer disposed on top of the first light guide layer; wherein the material of the first light guide layer is different from the material of the second light guide layer, and the refractive index of the first light guide layer is greater than the refractive index of the second light guide layer.

[0010] The material of the first light guide layer may include silicon, and the material of the second light guide layer may include barium sulfate and resin.

[0011] The composition ratio of the barium sulfate to the resin may be 1:4.

[0012] The thickness of the first light guide layer may be greater than the thickness of the second light guide layer.

[0013] The light source may be a side view type light emitting diode.

[0014] The light-emitting device may include a light-reflecting layer disposed on the printed circuit board to reflect light emitted from the light source.

[0015] The first light guide layer may have a refractive index of 1.5 to 1.6 or less, and the second light guide layer may have a refractive index of 1.4 to 1.5 or less.

[0016] The first light guide layer may have a thickness of 2 mm to 4 mm or less, and the second light guide layer may have a thickness of 0.4 mm to 1.0 mm or less.

[0017] The thickness of the second light guide layer may be 0.13 to 0.34 times the thickness of the first light guide layer.

[0018] In another embodiment, the light source module includes: a printed circuit board; a light source disposed on the printed circuit board; a first light guide layer disposed on the printed circuit board and accommodating the light source; and a second light guide layer disposed on top of the first light guide layer; wherein the material of the first light guide layer is different from the material of the second light guide layer, and the thickness of the first light guide layer is greater than the thickness of the second light guide layer. [Effects of the Invention]

[0019] According to the present invention, since light is irradiated onto the first and second optical guide layers having different refractive indices, the uniformity of light is increased and hot spots can be eliminated. [Brief explanation of the drawings]

[0020] [Figure 1] 1 is a cross-sectional view of a light source module according to an embodiment of the present invention. [Figure 2] FIG. 2 is an enlarged view of a part of FIG. [Figure 3] 10 is a diagram comparing the illumination angle of light depending on the material of the first and second optical guide layers. [Figure 4] 10 is a diagram comparing hot spots caused by differences in materials between a first optical guide layer and a second optical guide layer. [Figure 5] 10 is a chart comparing the degree of light uniformity depending on the thickness of the first and second light guide layers. [Figure 6] 10 is a chart comparing the degree of light uniformity depending on the thickness of the first and second light guide layers. [Figure 7] 10 is a chart comparing the degree of light uniformity depending on the thickness of the first and second light guide layers. DETAILED DESCRIPTION OF THE INVENTION

[0021] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

[0022] However, the technical concept of the present invention is not limited to the described embodiments, but can be realized in various different forms, and one or more of the components of the embodiments can be selectively combined or substituted within the scope of the technical concept of the present invention.

[0023] Furthermore, unless otherwise clearly and specifically defined, terms (including technical and scientific terms) used in the embodiments of the present invention shall be interpreted as meanings that can be commonly understood by a person having ordinary knowledge in the technical field to which the present invention belongs, and commonly used terms such as predefined terms should be interpreted in light of the contextual meaning of the relevant art.

[0024] Furthermore, the terms used in the examples of the present invention are intended to describe the examples and are not intended to limit the present invention. In this specification, the singular can include the plural unless otherwise specified in the context, and when it is stated as "A and (and) at least one (or more) of B and C," it can include one or more of all possible combinations of A, B, and C.

[0025] Additionally, terms such as first, second, A, B, (a), (b), etc. may be used to describe components of embodiments of the present invention.

[0026] Such terms are used only to distinguish one component from another, and are not intended to limit the nature, order, or sequence of the components.

[0027] Furthermore, when a component is described as being 'coupled', 'coupled' or 'connected' to another component, this includes not only the case where the component is directly coupled, coupled or connected to the other component, but also the case where the component is 'coupled', 'coupled' or 'connected' by another component between the component and the other component.

[0028] Furthermore, when it is described as being formed or disposed "above (above) or below (below)" each component, "above (above)" or "below (below)" includes not only the case where two components are in direct contact with each other but also the case where one or more additional components are formed or disposed between the two components. Furthermore, when it is expressed as "above (above) or below (below)," it can mean not only the upper direction but also the lower direction based on one component.

[0029] FIG. 1 is a cross-sectional view of a light source module according to an embodiment of the present invention, FIG. 2 is an enlarged view of a portion of FIG. 1, FIG. 3 is a diagram comparing the light irradiation angle depending on the material difference between the first light guide layer and the second light guide layer, FIG. 4 is a diagram comparing the hot spots depending on the material difference between the first light guide layer and the second light guide layer, and FIGS. 5 to 7 are charts comparing the light uniformity depending on the thickness of the first light guide layer and the second light guide layer.

[0030] 1 and 2, a light source module 100 according to an embodiment of the present invention may include a printed circuit board 110, a light source 120, a light reflecting layer 130, a first light guide layer 140, and a second light guide layer 150.

[0031] The printed circuit board 110 may be formed in a plate shape, and the light source 120 may be mounted on an upper surface thereof. The light source 120 may include a light emitting diode (LED). A plurality of light sources 120 may be provided and arranged spaced apart from each other on the printed circuit board 110. The light source 120 may provide light. The light source 120 may be a side-view type LED. Alternatively, the light source 120 may be a direct-type LED.

[0032] The light reflective layer 130 may be disposed on the upper surface of the printed circuit board 110. The light reflective layer 130 may be formed in a plate shape and disposed on the printed circuit board 110. The light reflective layer 130 may reflect light generated by the light source 120 to an illuminated area. The light reflective layer 130 may have holes that form an area for arranging the light source 120. The light source 120 may be mounted on the printed circuit board 110 through the holes. A plurality of reflective patterns (not shown) may be disposed on the upper surface of the light reflective layer 130. The plurality of reflective patterns (not shown) may further reflect light generated by the light source 120 to an upper area, and the plurality of reflective patterns may be disposed to include an area where each area of ​​the reflective pattern increases or where the density of the reflective patterns increases as the distance from the light source 120 increases. Since the light emitted from the light source 120 becomes weaker as it moves away from the light source 120, in order to achieve uniformity of light from the light source module 100, the emitted light must be reflected further upward as it moves away from the light source 120, and therefore the arrangement of the multiple reflective patterns (not shown) can be carried out as described above.

[0033] A first light guide layer 140 and a second light guide layer 150 may be disposed on the printed circuit board 110 and the light reflecting layer 130. The first light guide layer 140 and the second light guide layer 150 may be stacked vertically. The first light guide layer 140 may accommodate the light source.

[0034] The first light guide layer 140 may be formed to a first thickness (T1). The second light guide layer 150 may be formed to a second thickness (T2). The first thickness (T1) may be greater than the second thickness (T2). The top surface of the first light guide layer 140 may be disposed higher than the top surface of the light source 120. The first thickness (T1) may be greater than the height of the light source 120.

[0035] The first light guide layer 140 and the second light guide layer 150 may be made of different materials. For example, the first light guide layer 140 may be made of silicon. The second light guide layer 150 may be made of a mixture of barium sulfate and resin. The second light guide layer 150 may be made of a mixture of barium sulfate and resin in a ratio of 1:4. As a result, the first light guide layer 140 and the second light guide layer 150 may have different refractive indices. The refractive index of the first light guide layer 140 may be higher than the refractive index of the second light guide layer 150.

[0036] For example, the refractive index of the first light guide layer 140 may range from 1.5 to 1.6, and the refractive index of the second light guide layer 150 may range from 1.4 to 1.5.

[0037] With the above structure, light generated from the light source 120 can be guided through a plurality of light guide layers 140 and 150 having different refractive indices. Specifically, the light is diffused through the second light guide layer 150, which has a lower refractive index than the first light guide layer 140, thereby forming a more uniform surface light source.

[0038] If the first light guide layer 140 and the second light guide layer 150 are made of the same material, as shown in FIG. 3(a), the light generated from the light source 3 is irradiated onto the first light guide layer 1 and the second light guide layer 2 at the same angle relative to the horizontal plane, resulting in a decrease in the uniformity of the light in the horizontal direction. In addition, the light emitted from the light source 3 travels in a straight line without changing its path, which can cause hot spots in areas close to the light source 3.

[0039] However, when the first light guide layer 140 and the second light guide layer 150 are made of different materials as in this embodiment, the difference in refractive index between the materials causes the light generated from the light source 120 to be irradiated onto the first light guide layer 140 and the second light guide layer 150 at different angles relative to the horizontal plane, as shown in FIG. 3(b). This improves the uniformity of the light in the horizontal direction, and the path of the light emitted from the light source 120 is changed when it enters the second light guide layer 150 from the first light guide layer 140, thereby reducing hot spots in the area near the light source 120.

[0040] That is, the light generated from the light source 120 may be irradiated at a lower angle with respect to the horizontal plane on the second light guide layer 150 than on the first light guide layer 140. Therefore, the light generated from the light source 120 may be diffused more widely in the horizontal direction on the second light guide layer 150, thereby eliminating hot spots.

[0041] 4, when the first light guide layer 140 and the second light guide layer 150 are made of the same material (FIG. 4(a)), a brightness of 89908 cd / m2 is formed in the hot spot generation area. However, according to this embodiment (FIG. 4(b)), a brightness of 80326 cd / m2 is formed in the hot spot generation area, and it can be confirmed that the hot spot generation area is smaller than when the first light guide layer 140 and the second light guide layer 150 are made of the same material.

[0042] FIG. 5 is a graph showing the light uniformity according to the thickness of the second light guide layer 150 when the first thickness (T1) of the first light guide layer 140 is 2 mm.

[0043] FIG. 6 is a graph showing the light uniformity according to the thickness of the second light guide layer 150 when the first thickness (T1) of the first light guide layer 140 is 3 mm.

[0044] FIG. 7 is a graph showing the light uniformity according to the thickness of the second light guide layer 150 when the first thickness (T1) of the first light guide layer 140 is 4 mm.

[0045] 5 to 7, Min [nit] on the vertical axis represents the minimum luminance value of the light source module 100, Max [nit] represents the maximum luminance value of the light source module 100, Mean [nit] represents the average value of the light source module 100, and Homogeneity represents the uniformity of the light emitted by the light source module 100. In addition, the horizontal axis 1 represents the luminance value for the entire area of ​​a line crossing the center of the light source module 100, and 2 represents the luminance value for a partial area of ​​the line crossing the center of the light source module 100.

[0046] 5 to 7, it can be seen that when the first light guide layer 140 is 3 mm, the uniformity of light emitted from the second light guide layer 150 is the highest. Therefore, when the thickness of the first light guide layer 140 is 2 mm to 4 mm or less, it can be seen that a higher light uniformity is formed than in other sections.

[0047] FIG. 5(I) is a graph showing the light uniformity when the second thickness (T2) of the second light guide layer 150 is 0.4 mm.

[0048] FIG. 5(II) is a graph showing the light uniformity when the second thickness (T2) of the second light guide layer 150 is 0.7 mm.

[0049] FIG. 5(III) is a graph showing the light uniformity when the second thickness (T2) of the second light guide layer 150 is 1.0 mm.

[0050] 5(I) to 5(III), it can be seen that the light uniformity increases as the second thickness (T2) of the second light guide layer 150 increases. Therefore, when the thickness of the first light guide layer 140 is in the range of 2 mm to 4 mm or less and the thickness of the second light guide layer 150 is in the range of 0.4 mm to 1.0 mm or less, it can be seen that a higher light uniformity is formed than in other ranges.

[0051] 5 to 7, when the first thickness (T1) of the first light-guiding layer 140 is 3 mm, even if the second thickness (T2) of the second light-guiding layer 150 is 0.4 mm, the uniformity of the light emitted from the second light-guiding layer 150 is higher than when the first thickness (T1) of the first light-guiding layer 140 is 2 mm or 4 mm, as shown in FIGS. 5 and 7. Therefore, when the ratio of the first thickness (T1):second thickness (T2)=3 mm:0.4 mm to 1.0 mm is satisfied, the uniformity of the light can be increased at a low cost. That is, the second thickness (T2) is preferably formed to satisfy a ratio of 0.13 to 0.34 relative to the first thickness (T1), more preferably to satisfy a ratio of 0.23 to 0.34 relative to the first thickness (T1), and when the second thickness (T2) is formed to satisfy a ratio of 0.33 to 0.34 relative to the first thickness (T1), the most uniform light can be realized.

[0052] Although all components constituting the embodiments of the present invention have been described above as being combined or operating in combination, the present invention is not necessarily limited to such embodiments. That is, all components may be selectively combined and operate in combination, provided that they are within the scope of the present invention. Furthermore, unless otherwise specified, the terms "comprise," "comprise," "have," etc., used above mean that the corresponding component may be present, and should be interpreted as including other components rather than excluding other components. All terms, including technical and scientific terms, have the same meaning as commonly understood by those skilled in the art to which the present invention pertains, unless otherwise defined. Commonly used terms, such as predefined terms, should be interpreted in accordance with the context of the relevant art and should not be interpreted in an idealized or overly formal sense unless expressly defined herein.

[0053] The above description is merely illustrative of the technical concept of the present invention, and various modifications and alterations may be made by those skilled in the art without departing from the essential characteristics of the present invention. Therefore, the embodiments disclosed herein are for illustrative purposes only, and are not intended to limit the technical concept of the present invention. The scope of the present invention should be interpreted by the following claims, and all technical concepts within the scope equivalent thereto should be construed as being within the scope of the present invention.

Claims

1. a printed circuit board; a light source disposed on the printed circuit board; a first light guide layer disposed on the printed circuit board and accommodating the light source; a second light guide layer disposed on an outer surface of the first light guide layer; the material of the first light guide layer is different from the material of the second light guide layer; The refractive index of the first light guide layer is greater than the refractive index of the second light guide layer; the thickness of the first optical guide layer is 1, the thickness of the second optical guide layer is 0.1 to 0.25; The material of the second light guide layer includes barium sulfate and resin, and the composition ratio of the barium sulfate to the resin is 1:

4.

2. The light source module according to claim 1 , wherein the material of the first light guide layer includes silicon.

3. The light source module according to claim 1 , wherein the thickness of the first light guide layer is greater than the thickness of the second light guide layer.

4. 4. The light source module according to claim 1, wherein the light source is a side view type light emitting diode.

5. The light source module according to claim 1 , further comprising a light reflecting layer disposed on the printed circuit board for reflecting light emitted from the light source.

6. The refractive index of the first optical guide layer is 1.5 to 1.6 or less, The light source module according to claim 1 , wherein the refractive index of the second light guide layer is 1.4 to 1.

5.

7. The thickness of the first light guide layer is 4 mm. The light source module according to claim 3 , wherein the second light guide layer has a thickness of 0.4 mm to 1.0 mm.

8. a printed circuit board; a light source disposed on the printed circuit board; a first light guide layer disposed on the printed circuit board and accommodating the light source; a second light guide layer disposed on an outer surface of the first light guide layer; the material of the first light guide layer is different from the material of the second light guide layer; The thickness of the first light guide layer is greater than the thickness of the second light guide layer; the thickness of the first optical guide layer is 1, the thickness of the second optical guide layer is 0.1 to 0.25; The material of the second light guide layer includes barium sulfate and resin, and the composition ratio of the barium sulfate to the resin is 1:4.

Images