EP4729825A1

EP4729825A1 - Lighting module, lighting device, and line lamp

Info

Publication number: EP4729825A1
Application number: EP24840026.9A
Authority: EP
Inventors: Dong Il Eom; Sa Rum Han; Eay Jin LIM; Kwang Hyun Ko
Original assignee: LG Innotek Co Ltd
Current assignee: LG Innotek Co Ltd
Priority date: 2023-07-07
Filing date: 2024-07-08
Publication date: 2026-04-22
Also published as: WO2025014214A1; CN121511374A

Abstract

A lighting device disclosed in an embodiment of the invention comprises: a substrate; a plurality of light sources arranged on the substrate; and a light guide member including a light guide portion sealing the plurality of light sources on the substrate and a diffusion layer disposed on the light guide portion, wherein the plurality of light sources include a reflective body, a cavity concave on an upper surface of the reflective body, and a light emitting chip disposed on a bottom of the cavity, wherein 1/2 of the maximum width of the cavity is A, the height of the cavity is B, a pitch between adjacent light sources is D, a thickness of the light guide member is T, and a formula: Uni_Min_0.7=K1*(T/D) - K2*(B/A) + K3 is satisfied, wherein Uni_Min_0.7 represents a light uniformity of at least 70% on the light guide member and satisfies the condition of B < A, and K1, K2, and K3 are different constants having values greater than 0 and less than 1.

Description

[Technical Field]

An embodiment relates to a lighting module having a light source. An embodiment relates to a lighting device and a line lamp having the lighting module.

[Background Art]

Lighting applications include vehicle lights as well as backlights for displays and signs. Light emitting device, such as light emitting diode (LED), have advantages such as low power consumption, semi-permanent life, fast response speed, safety, and environmental friendliness compared to conventional light sources such as fluorescent lamps and incandescent lamps. These light emitting diodes are applied to various display devices, various lighting devices such as indoor or outdoor lights. A lamp employing a light emitting diode as a vehicle light source has been proposed. Compared with incandescent lamps, light emitting diodes are advantageous in that power consumption is small. Since the light emitting diode is small, it may increase the design freedom of the lamp, and it is economical due to its semi-permanent life.
However, since the light emitting diode has the highest luminous intensity in the direction of the optical axis, a hot spot occurs in the direction of the optical axis, and also, if multiple light emitting diodes are simply arranged, the uniformity of light may be reduced.

[Disclosure]

[Technical Problem]

An embodiment of the invention provides a lighting module and a lighting device with improved light uniformity. An embodiment of the invention provides a lighting module and a lighting device for improving light uniformity according to a pitch between light sources, a thickness of a light guide member, a thickness of the lighting module, and a ratio of a cavity of the light source. An embodiment of the invention may provide a lamp for a vehicle, such as a moving object, having a line-shaped beam.

[Technical Solution]

A lighting module according to an embodiment of the invention comprises: a substrate; a plurality of light sources arranged on the substrate; and a light guide member including a light guide portion sealing the plurality of light sources on the substrate and a diffusion layer disposed on the light guide portion, wherein the plurality of light sources include a reflective body, a cavity concave on an upper surface of the reflective body, and a light emitting chip disposed on a bottom of the cavity, wherein 1/2 of the maximum width of the cavity is A, a height of the cavity is B, a pitch between adjacent light sources is D, a thickness of the light guide member is T, and the following Formula satisfies: Uni_Min_0.7=K1*(T/D) - K2*(B/A) + K3, wherein Uni_Min_0.7 represents a light uniformity of at least 70% on the light guide member and satisfies the condition of B < A, and K1, K2, and K3 are different constants having values greater than 0 and less than 1.
The invention may satisfy condition 1: K2 < K1. The invention satisfies condition 2: K2 < K1 < K3. The invention satisfies condition 3: 2.1 < K1/K2 < 4.1. The invention satisfies condition 4: 1 < K1/K3 < 2. The invention satisfies condition 5: 1 < (K1*(T/D) - K2*(B/A)) / K3 < 2.5. The invention satisfies condition 6: 0.2 < (K1*(T/D) < 0.5. The invention satisfies condition 7: 0.01 < K2*(B/A) < 0.3. The invention may have a light uniformity of 70% or more on the light guide member.
According to an embodiment of the invention, the light guide member has a length in a first direction that is longer than a width in a second direction, and the plurality of light sources may be arranged in a single row within the light guide member. In the invention, the maximum width of the cavity of the light source may be a width in the first direction. In the invention, the thickness of the light guide member may be greater than a thickness of the diffusion layer.
A lighting module according to an embodiment of the invention includes a substrate having a length in a second direction that is longer than a width in the first direction; a plurality of light sources arranged in a single row on the substrate; a light guide portion sealing the plurality of light sources on the substrate; and a diffusion layer disposed on the light guide portion, wherein a thickness of the light guide portion is greater than a thickness of the diffusion layer, and the thickness of the light guide portion is T1, and a pitch between adjacent light sources arranged in one direction is D1, satisfying Formula 1: D1 ≤ K1 + (K2*T1), where K1 is a constant that is constantly added to the value of (K2*T1), and K2 is a constant for reducing the thickness of the light guide portion 15 by a predetermined ratio and may have a value smaller than K1.
In the invention, the constants K1 and K2 may satisfy Condition 1: 1.1 < K1 < 1.6, 0.5 < K2 < 1, and 1.2 < K1/K2 < 1.7. According to an embodiment of the invention, the pitch between adjacent light sources may satisfy a range of 100% to 130% of the thickness of the light guide portion, and the pitch between adjacent light sources may be in a range of 5 mm to 9 mm.
A lighting device according to an embodiment of the invention comprises: a substrate having a length in a second direction longer than a width in a first direction; a plurality of light sources arranged in a second direction on a substrate; a light guide member including a light guiding portion sealing the plurality of light sources on the substrate and a diffusion layer disposed on the light guide member; and reflective members disposed on both sides of the light guide member, wherein the plurality of light sources include a reflective body, a cavity concave on an upper surface of the reflective body, and a light emitting chip disposed on a bottom of the cavity, wherein 1/2 of a maximum width of the cavity is A, a height of the cavity is B, a pitch between adjacent light sources is D, a thickness of the light guide member is T, and the formula: Uni_Min_0.7 = K1*(T/D) - K2*(B/A) + K3 is satisfied, wherein Uni_Min_0.7 represents a light uniformity of at least 70% on the light guide member, satisfies the condition of B < A, and K1, K2, and K3 may be different constants having values less than 1.
In the invention, the width of the substrate in the first direction is a width of the light guide portion in the first direction, and the thickness of the light guide portion may be thicker than that of the diffusion layer. In the invention, K1, K2, and K3 satisfy the following conditions 1 and 2, and may satisfy condition 1: K1 < K3 < 2*K1, and condition 2: 2*K2 < K1 < 4*K2.
The invention may have a value of the ratio B/A of the cavity in a range of 0.25 to 0.35 or a range of 0.5 to 0.7. The invention satisfies condition 3: (K1*(T/D)+ K2*(B/A)) < K3. The invention satisfies condition 4: 0 < K2 < K1 < 0.5.

[Advantageous Effects]

A lighting module according to an embodiment of the invention can provide improved luminance and image uniformity. Furthermore, it can provide illumination with a line width and provide a uniform light distribution of the line illumination.
The embodiment of the invention can utilize the illumination image in various forms and improve the optical reliability of the lighting module and vehicle lamps having the module. The embodiment of the invention may be applied to a light unit having a lighting module, or to an external or internal lighting lamp.

[Description of Drawings]

FIG. 1 is a perspective view of a lighting module according to an embodiment.
FIG. 2 is a plan view of the lighting module of FIG. 1.
FIG. 3 is a cross-sectional view of the lighting module of FIG. 1 taken in a first direction.
FIG. 4 is a cross-sectional view of the lighting module of FIG. 1 taken in a second direction.
FIG. 5 is a partially enlarged view of FIG. 4.
FIG. 6 is a drawing illustrating a detailed configuration of the light source of FIG. 5.
FIG. 7 is another example of the lighting module of FIG. 3.
FIG. 8(A) is a drawing illustrating a structure in which dark regions are eliminated by adjusting the thickness of the light guide member and the position of the light source according to the invention, and FIG. 8(B) is a drawing illustrating a drawing in which dark regions are generated by adjusting the thickness of the light guide member and the position of the light source.
FIG. 9(A) is a drawing illustrating the luminous intensity of the lighting module of FIG. 2, and FIG. 9(B) is an example of the luminous intensity graph of FIG. 9(A).
FIG. 10a is a graph showing the distribution of changes in light uniformity according to the cavity ratio of each light source in a first sample of a lighting module according to an embodiment of the invention.
FIG. 10b is a graph showing the distribution of changes in light uniformity according to the cavity ratio of each light source in a second sample of a lighting module according to an embodiment of the invention.
FIG. 10c is a graph showing the distribution of changes in light uniformity according to the cavity ratio of each light source in a third sample of a lighting module according to an embodiment of the invention.
FIG. 11 is a graph comparing the distributions of light uniformity according to the first, second, and third samples of a lighting module according to an embodiment of the invention.
FIG. 12a is a graph showing the distribution of changes in light uniformity according to a formula value in a first sample of a lighting module according to an embodiment of the invention.
FIG. 12b is a graph showing the distribution of changes in light uniformity according to a formula value in a second sample of a lighting module according to an embodiment of the invention.
FIG. 12c is a graph showing the distribution of changes in light uniformity according to the formula value in the third sample of the lighting module according to an embodiment of the invention.
FIG. 13 is a graph comparing the distribution of changes in the formula value according to the first, second, and third samples of the lighting module according to an embodiment of the invention with the cavity ratio of the light source.
FIG. 14a is a graph showing the uniformity values, formula values, and the uniformity/formula value ratio obtained from the first sample of FIGS. 11a and 12a.
FIG. 14b is a graph showing the uniformity values, formula values, and the uniformity/formula value ratio obtained from the second sample of FIGS. 11b and 12b.
FIG. 14c is a graph showing the uniformity values, formula values, and the uniformity/formula value ratio obtained from the first sample of FIGS. 11c and 12c.
FIG. 15 is a graph comparing the light uniformity according to variations in the thickness of the resin layer of a lighting module and the pitch between light sources according to an embodiment of the invention.
FIG. 16 is an example of a lighting state in which some light sources are exposed on the lighting module of FIG. 2.
FIG. 17 is an example of a cross-sectional view of a modified example of the invention, in which a lens is combined with the lighting module of FIG. 3.
FIG. 18 is a drawing of a lamp having a lighting module according to an embodiment of the invention.
FIG. 19 is an example of the vehicle taillight of FIG. 18.

[Best Mode]

Hereinafter, preferred embodiment of the invention will be described in detail with reference to the accompanying drawings.
The technical spirit of the invention is not limited to some embodiments to be described, and may be implemented in various other forms, and one or more of the components may be selectively combined and substituted for use within the scope of the technical spirit of the invention. In addition, the terms (including technical and scientific terms) used in the embodiments of the invention, unless specifically defined and described explicitly, may be interpreted in a meaning that may be generally understood by those having ordinary skill in the art to which the invention pertains, and terms that are commonly used such as terms defined in a dictionary should be able to interpret their meanings in consideration of the contextual meaning of the relevant technology. Further, the terms used in the embodiments of the invention are for explaining the embodiments and are not intended to limit the invention. In this specification, the singular forms also may include plural forms unless otherwise specifically stated in a phrase, and in the case in which at least one (or one or more) of A and (and) B, C is stated, it may include one or more of all combinations that may be combined with A, B, and C. In describing the components of the embodiments of the invention, terms such as first, second, A, B, (a), and (b) may be used. Such terms are only for distinguishing the component from other component, and may not be determined by the term by the nature, sequence or procedure etc. of the corresponding constituent element. And when it is described that a component is "connected ", "coupled" or "joined" to another component, the description may include not only being directly connected, coupled or joined to the other component but also being "connected ", "coupled" or "joined" by another component between the component and the other component. In addition, in the case of being described as being formed or disposed "above (on)" or "below (under)" of each component, the description includes not only when two components are in direct contact with each other, but also when one or more other components are formed or disposed between the two components. In addition, when expressed as "above (on)" or "below (under)", it may refer to a downward direction as well as an upward direction with respect to one element.
The lighting device according to the invention may be applied to a variety of lamp devices that require lighting, such as vehicle lamps, home lighting devices, or industrial lighting devices. For example, when applied to vehicle lamps, it is applicable to headlamps, sidelights, side mirrors, fog lights, tail lamps, brake lights, daytime running lights, vehicle interior lights, door scars, rear combination lamps, backup lamps, etc. The lighting device of the invention may be applied to indoor and outdoor advertising devices, display devices, and various electric vehicle fields, and in addition, it may be applied to all lighting-related fields or advertisement-related fields that are currently developed and commercialized or that may be implemented according to future technological developments.

FIG. 1 is a perspective view of a lighting module according to an embodiment, FIG. 2 is a plan view of the lighting module of FIG. 1, FIG. 3 is a cross-sectional view of the lighting module of FIG. 1 taken in a first direction, FIG. 4 is a cross-sectional view of the lighting module of FIG. 1 taken in a second direction, FIG. 5 is a partial enlarged view of FIG. 4, FIG. 6 is a drawing showing a detailed configuration of the light source of FIG. 5, FIG. 7 is another example of the lighting module of FIG. 3, and FIG. 8(A) (B) are drawings comparing the occurrence of dark regions on the lighting modules of the invention and comparative examples.
Referring to FIGS. 1 to 6, a lighting module 10 according to an embodiment of the invention may include a substrate 11, a light source 13 arranged on the substrate 11, a light guide portion 15 covering the light source 13, and a diffusion layer 17 on the light guide portion 15. The light guide portion 15 and the diffusion layer 17 may be defined as a light guide member 19. The light guide member 19 may further include a light-transmitting layer on the upper surface of the light guide portion 15 and/or a light-transmitting layer on the upper or lower surface of the diffusion layer 17, and the light-transmitting layer may include at least one or two or more of a transparent resin layer, an adhesive layer, a phosphor layer, and an ink layer. The light guide member 19 may include a resin member or a light-transmitting member.
The lighting module 10 may be provided as a line-shaped beam. The line-shaped beam is a light in which a length of the illuminated region is at least twice or at least 50 times longer than the width of the illuminated region. The lighting module 10 may have a length in the second direction Y that is greater than the width W1 in the first direction X, for example, at least twice or at least 50 times longer. The lighting module 10 may be defined as a line-shaped beam having a line width (e.g., W1 of FIG. 3) or a surface light module having a line width. The width W1 of the lighting module 10 in the first direction X is the maximum width of the light guide portion 15 in the first direction X, and may be, for example, the width of the lower surface of the light guide portion 15. As another example, the width W1 of the lighting module 10 may be the upper width of the light guide portion 15 or the upper width of the diffusion layer 17. The lighting module 10 may provide line beam having a narrow width W1 and a long length in the second direction Y, and the line beam may emit surface light in the form of a line having a narrow width with a uniform distribution. In the drawing, the X direction may be a first direction, the Y direction may be a second direction orthogonal to the X direction, and the Z direction may be a thickness direction or a vertical direction of the lighting module 10 and a third direction orthogonal to the first and second directions X and Y.
The thickness of the lighting module 10 may be greater than the width W1 in the first direction X and less than the length in the second direction Y. The thickness of the lighting module 10 is the distance in the vertical direction Z from the lower surface of the substrate 11 to the upper surface of the light guide member or diffusion layer 17. The ratio of the thickness and width W1 of the lighting module 10 may be arranged in a range of 4:3 to 10:3. The thickness of the lighting module 10 may be 4 mm or more, for example, in the range of 4 mm to 10 mm. The width W1 of the lighting module 10 may be 7 mm or less, for example, in the range of 3 mm to 7 mm or in the range of 4 mm to 6.5 mm. The thickness of the lighting module 10 may be 1.3 times or more, for example, in the range of 1.3 to 3 times or in the range of 1.3 to 2.5 times the width W1. Since the lighting module 10 has a narrow width W1, a partial region of the lighting module 10 is deformable to be convexly or concavely bent toward one side or both sides in a first direction X with respect to a second direction Y. Since the lighting module 10 has a low thickness, a partial region of the lighting module 10 is deformable to be convexly or concavely bent in a third direction Z with respect to the second direction Y.
The substrate 11 of the lighting module 10 may include a printed circuit board (PCB). The substrate 11 may include, for example, at least one of a resin-based PCB, a metal core PCB, a flexible PCB, a ceramic PCB, or an FR-4 substrate. If the substrate 11 is a flexible PCB, a lighting device including the lighting module 10 may be provided with flexibility.
The upper surface of the substrate 11 may have an X-Y plane. The upper surface of the substrate 11 may be a flat plane or a curved surface. The thickness of the substrate 11 may be a height in the vertical direction or the Z direction. The substrate 11 may function as a base member or a support member disposed below the light source 13 and the light guide portion 15. A heat dissipation plate or heat dissipation fin may be further disposed below the substrate 11. The substrate 11 may be electrically connected to the light source 13. The substrate 11 includes a wiring layer (not shown) on the upper portion, and the wiring layer may be electrically connected to the light source 13. When the light sources 13 are arranged in plurality along the second direction Y on the substrate 11, the plurality of light sources 13 are electrically connected to the substrate 11, and for example, the light sources 13 may be connected in series, in parallel, or in series-parallel. The plurality of light sources 13 may be arranged in the second direction Y on the substrate 11.
The substrate 11 may be made of a flexible material, and the substrate made of the flexible material may be adhered to the housing of the lamp in the vehicle. As another example, the substrate 11 may include a light-transmitting material that transmits light through the upper and lower surfaces. The light-transmitting material may include at least one of polyethylene terephthalate (PET), polystyrene (PS), and polyimide (PI). A reflective layer (not shown) may be disposed on the substrate 11. The reflective layer is disposed between the substrate 11 and the light guide portion 15 and may reflect incident light. The reflective layer may include a metallic material or a non-metallic material. The metallic material may include a metal such as aluminum, silver, or gold. The non-metallic material may include a plastic material or a resin material.
The width of the substrate 11 in the first direction X may be greater than the width W1 of the light guide portion 15. The width of the substrate 11 in the first direction X may be greater than the upper width of the lighting module 10, for example, the width W1 of the light guide portion 15. Accordingly, the substrate 11 supports the lower portion of the light guide portion 15, and may block light leaking to the side of the light guide portion 15 from proceeding to the lower portion of the substrate 11.
The plurality of light sources 13 are arranged between the substrate 11 and the light guide portion 15 and can emit light through the upper surface of the light guide portion 15. The plurality of light sources 13 may be arranged along the second direction Y or the longitudinal direction of the substrate 11. The plurality of light sources 13 may be arranged below the light guide portion 15 and arranged in one row along the longitudinal direction of the light guide portion 15. As another example, the plurality of light sources 13 may be arranged in two or more rows.
The light sources 13 may be embedded in the lower portion of the light guide portion 15. That is, the light guide portion 15 seals the light sources 13. The upper surface of the light source 13 may be positioned higher than the lower surface of the light guide portion 15, and multiple side surfaces and the upper surface of the light source 13 may be in contact with the light guide portion 15.
The light source 13 emits light with the highest intensity in the third direction Z or along the optical axis within the light guide portion 15. The light source 13 may be a light emitting device having an LED chip. The light emitting device may be provided in a package in which the surface of the LED chip is covered with resin. The LED chip, as the light emitting chip 13 of the light source 13, may emit at least one of blue, red, green, ultraviolet (UV), or infrared light. The light source 13 may emit at least one of white, blue, red, green, or infrared light, and may emit light in a color such as white, blue, green, or red, for example.
The light source 13 has a light emitting surface 13A on its upper surface and can emit light toward the upper surface of the light guide portion 15. The upper surface of the light source 13 may face the upper surface of the light guide portion 15. Specifically, since the light source 13 has a reflective body 32 (See FIG. 6) disposed around the periphery of the light emitting chip 31, the light beam angle of the light source 13 becomes smaller than the light beam angle of the light emitting chip 13. This reduction in the light beam angle can cause the light distribution to vary depending on the distance between adjacent light sources 13, i.e., the pitch D.
The pitch D between the light sources 13 may be 4 mm or more, for example, in the range of 4 mm to 30 mm. In detail, the pitch D between the light sources 13 may be 6 mm or more, for example, in the range of 6 mm to 15 mm or 8 mm to 13 mm. If the pitch D is smaller than the above range, the number of light sources 13 increases, making it difficult to control the brightness. If it is larger than the above range, it may be difficult to secure the brightness uniformity. In addition, if the pitch D between the light sources 13 is narrow, the number of light sources 13 may increase the cost, and the content of the diffusion agent in the diffusion layer 17 may also increase to lower the brightness. In addition, if the pitch D between the light sources 13 is wide, dark regions may occur in the area between adjacent light sources 13, and the dark regions occurring in the area between the light sources 13 may lower the brightness uniformity and the reliability of the lighting module 10. In addition, the uniformity of the line surface light of the lighting module 10 may be lowered. An embodiment of the invention can provide a uniform light distribution by optimizing the directional characteristics of light sources 13, the pitch D between the light sources 13, and the thickness T of the light guide member 19. The light guide member 19 may include a light guide portion 15 and a diffusion layer 17.
As shown in FIG. 6, the light source 13 may include a light emitting chip 31, a reflective body 32 having a concave upper cavity 35, a metallic frame 33 and 34 electrically connected to the light emitting chip 31, and a connecting member 37 electrically connecting the electrodes of the light emitting chip 31 to the metallic frame 33 and 34. The reflective body may comprise a resin material. The metallic frame may comprise at least one of copper, silver, gold, nickel, aluminum, or an alloy material, and may be provided as a conductive frame. The connecting member 37 may be made of a wire material such as gold or silver, or a solder material.
The light emitting chip 31 may be disposed at the center of the bottom of the cavity 35. The light emitting chip 31 may be disposed on any one of the metallic frames 33 and 34 disposed on the bottom of the cavity 35, and may supply power and emit light through the metallic frames 33 and 34.
The light emitting chip 31 is sealed in a molding member 36. The molding member 36 is made of a resin material such as silicone or epoxy, and may be filled in the cavity 35. The surface of the molding member 36 becomes the light-emitting surface of the light source 13.
The shape of the cavity 35 of the reflective body 32 may have a cross-sectional side polygonal shape, for example, an inverted trapezoidal shape. The cavity 35 may have a polygonal bottom shape, for example, a square shape, and a polygonal top shape, for example, a square shape. The peripheral surface of the cavity 35 may be an inclined plane or a concave curved surface.
The light source 13 extracted through the cavity 35 may have a beam angle ranging from 60 to 150 degrees or from 80 to 125 degrees. If the beam angle of the light source 13 is greater than this range, the luminous intensity may be reduced, and if it is less than this range, the light extraction efficiency may be reduced.
As shown in FIG. 6, the light path emitted from the light emitting chip 31 may be emitted vertically upward and outward. Here, the first light L1 generated within the light source 13 is reflected by the reflective body 32 and propagates upward from the light source 13. The second light L2 emitted from the light source 13 may travel along a path passing through the outer upper surface of the reflective body 32. The luminous intensity of the second light L2 in the region between two adjacent light sources 13 may be lower than the luminous intensity of the first light L1. In order to reduce this difference in luminous intensity and increase uniformity, a light extraction path having a uniform distribution may be provided by setting a value of half the maximum width of the cavity 35 or half the maximum width (i.e., 2*A) in the second direction Y based on the light emitting chip 31 located within the cavity 35 and the height B of the cavity 35. That is, conditions for optimizing the width and height ratio of the cavity 35 of the light source 13 may be set. Here, a first value A, which is one half of a maximum width of the cavity in a second direction Y, is defined as a distance from a center (i.e., the optical axis) of an upper surface of the light emitting chip, to an upper end of the cavity. The first value A may be 3 mm or less, for example, in a range from 0.462 mm to 3 mm. Preferably, the first value A may be 1 mm or more, for example, in a range from 0.8 mm to 1.5 mm. The second value B, which is the height of the cavity 35, is the distance from the bottom of the cavity 35 where the light emitting chip 31 is disposed, to the upper end of the cavity 35, and may be 3 mm or less, for example, in the range of 0 mm to 3 mm. Preferably, the second value B may be 0.5 mm or more, for example, in the range of 0.5 mm to 1 mm. Here, when the second value B is 0 mm, the structure has no reflective body 32 around the cavity 35.
The light guide portion 15 may be disposed on a portion of the upper surface of the substrate 11. The lower surface of the light guide portion 15 may face the substrate 11 or may be in contact with the upper surface of the substrate 11. The width of the light guide portion 15 in the first direction X may be equal to the upper width W1 of the lighting module 100 and may be smaller than the width of the substrate 11 in the first direction X. When a reflective layer (not shown) is disposed on the upper surface of the substrate 11, the light guide portion 15 may be in contact with the reflective layer.
The length of the light guide portion 15 in the second direction Y may be equal to or smaller than the length of the substrate 11 in the second direction. The length of the light guide portion 15 in the second direction Y may be equal to the length of the lighting module 10 or greater than 80% of the length of the lighting module 10 or the substrate 11. By extending the light guide portion 15 in the second direction Y, a surface light having a line width may be provided through the lighting module 10.
The length of the light guide portion 15 in the second direction Y may be at least twice the width W1 of the width W1 in the first direction X, for example, in the range of 2 to 200 times or 50 to 200 times. The width W1 of the light guide portion 15 in the first direction X may be 7 mm or less, for example, in the range of 3 to 7 mm or 4 to 6.5 mm. Since the length of the light guide portion 15 in the second direction Y is provided to be longer than the width W1 in the first direction X, the light guide portion 15 may be bent to one side in the first direction X with respect to the second direction Y and to one side in the third direction Z.
The lower surface area of the light guide portion 15 may be smaller than the upper surface area of the substrate 11. The outer side surfaces of the light guide portion 15 may be positioned further outward than the side surfaces of the light source 13. Accordingly, the light guide portion 15 seals the light sources 13, prevents moisture penetration, and sufficiently diffuses light. Here, the outer region of the upper surface of the substrate 11 may be exposed from the lower surface of the light guide portion 15.
The thickness T1 of the light guide portion 15 may be 80% or more of the distance (i.e., the thickness of the lighting module) from the upper surface of the substrate 11 to the lower surface of the diffusion layer 17. That is, the thickness T1 of the light guide portion 15 may be 80% or more and less than 100% of the thickness of the lighting module 10. Accordingly, the light guide portion 15 may guide the light emitted from the light source 13 in the emission direction (i.e., upward direction) and improve the diffusion efficiency of the light. The thickness T1 of the light guide portion 15 may be 6 mm or more, for example, in the range of 6 mm to 15 mm, and specifically, in the range of 8 mm to 13 mm. If the thickness T1 of the light guide portion 15 is smaller than the above range, the light diffusion distance may become too small, failing to provide a uniform light distribution. If the thickness T1 of the light guide portion 15 is larger than the above range, the size of the lighting module may increase. Both sides of the light guide portion 15 in the first direction X, i.e., the long sides, may be provided as vertical planes. A reflective coating layer may be formed on both sides of the light guide portion 15. The reflective coating layer reflects the incident light toward the output side and suppresses light loss.
The light guide portion 15 may be formed of a transparent material. The light guide portion 15 may include a resin material such as silicone or epoxy. The light guide portion 15 may include a thermosetting resin material, such as PC, OPS, PMMA, or PVC. The light guide portion 15 may be formed of glass, but is not limited thereto. For example, the main material of the light guide portion 15 may be a resin material containing urethane acrylate oligomer as its main ingredient. Since the light guide portion 15 is provided as a layer that guides light with resin, it may be provided with a thinner thickness than glass material and may be provided as a flexible plate. The light guide portion 15 may emit point light emitted from the light source 13 as line beam or surface light having a line width.
The light guide portion 15 may include beads (not shown), and the beads may diffuse and reflect incident light, thereby increasing the amount of light. The beads may be composed of any one selected from silicon, silica, glass bubbles, PMMA (Polymethyl methacrylate), urethane, zinc, zinc, aluminum oxide (Al₂O₃), and acrylic. The light guide portion 15 can protect the internal light source 13 and reduce light loss emitted from the light source 13. The light source 13 can overlap vertically with the emission surface of the light guide portion 15. When a diffusion layer 17 is disposed on the light guide portion 15, impurities, such as diffusion agents, may be removed from the light guide portion 15, and this removal of impurities can reduce light loss.
The diffusion layer 17 may be disposed on the light guide portion 15. The diffusion layer 17 may diffuse light emitted through the light guide portion 15. The diffusion layer 17 may include a diffusion agent, which may include at least one of Al₂O₃, TiO₂, SiO₂, ZnO, and ZrO₂. The diffusion layer 17 may be formed of a transparent resin or a translucent resin material. The diffusion agent in the diffusion layer 17 may be 6 wt% or more, for example, in the range of 6 wt% to 20 wt% or 6 wt% to 10 wt%. If it is less than the range, hot spots may occur, and if it is greater than the range, light extraction efficiency may decrease. The thickness T2 of the diffusion layer 17 may be less than the thickness T1 of the light guide portion 15, and may be less than 50% of the thickness T1 of the light guide portion 15. The thickness T2 of the diffusion layer 17 may be 2.5 mm or less, for example, in the range of 1 mm to 2.5 mm or 1.5 mm to 2 mm. When the diffusion layer 17 is in the range, the diffusion effect may be improved and the decrease in brightness may be suppressed.
The light guide member 19 includes the light guide portion 15 and the diffusion layer 17. The thickness T of the light guide member 19 is a vertical distance from the upper surface of the substrate 11 to the upper surface of the diffusion layer 17, and is the sum of the thickness T1 of the light guide portion 15 and the thickness T2 of the diffusion layer 17. In order to optimize the uniformity and brightness of the light emitted from the light sources 13, the thickness T of the light guide member 19 may be 25 mm or less, for example, in the range of 4 mm to 25 mm. Preferably, the thickness T of the light guide member 19 may be in the range of 6 mm to 18 mm, for example, in the range of 6 mm to 15 mm.
The lower surface of the diffusion layer 17 is adhered to the upper surface of the light guide portion 15 and may extend along the light guide portion 15. The width of the diffusion layer 17 in the first direction X may be equal to or smaller than the width W1 of the light guide portion 15 in the first direction, and the length of the diffusion layer 17 in the second direction Y may be equal to or smaller than the length of the light guide portion 15 in the second direction. Since the diffusion layer 17 is arranged on the upper side of the lighting module 10, the problem of hot spots occurring on the upper side of the light source 13 may be suppressed.
The upper surface of the diffusion layer 17 may have a convex shape. For example, it may have concave recesses R1 and R2 extending long in the second direction Y on both sides of the first direction X of the diffusion layer 17. The recesses R1 and R2 may reduce the width of the upper surface of the diffusion layer 17, thereby setting the width of the line beam. Furthermore, the recesses R1 and R2 serve as reflective surfaces, reflecting incident light toward the center of the upper surface of the diffusion layer 17, thereby reducing light loss. Since the upper surface of the light guide portion 15 is provided as a flat or horizontal surface, and the upper surface of the diffusion layer 17 is provided as a convex curved surface, light extraction efficiency may be improved. As another example, as shown in FIG. 7, the diffusion layer 17 may be provided without the recesses R1 and R2 described above. In this case, the upper sides of the diffusion layer 17 are provided as curved surfaces R3 and R4, and the emission area may be further expanded.
As shown in (A) of FIG. 8, when the light L3 generated by the light sources 13 is extracted through the light guide member 19, it may be seen that a dark region does not occur in the upper region A11 between the light sources 13 due to the conditions such as the directional angle characteristics of the light sources 13 set by the invention and the thickness T of the light guide member 19. As shown in (B) of FIG. 8, the comparative example is a structure in which the thickness Tc of the light guide member 19 is provided thinner than the thickness T of the light guide member 19 of the invention, and thus, when the light L4 emitted by the light sources 13 is extracted through the light guide member 19, it may be seen that a dark region occurs in the upper region A12 between the light sources 13. Additionally, light extracted through the lighting module 10 of the invention may be provided with a uniform light distribution (i.e., indicated by the thickness of the dotted line), as shown in (a) of FIG. 9, and may have a high luminous intensity in the center portion, as shown in (b) of FIG. 9.
If the lighting module 10 is provided without a separate air gap on the light guide member 19, light loss may be reduced. Specifically, as shown in FIG. 17, if an air gap C0 exists between the light guide member 19 and the optical lens 51, light loss can occur. Therefore, removing the optical lens 51 or the air gap C0 can reduce light loss.
The invention can increase the light uniformity to 70% or more by setting a first value A and a second value B which are the half-width and height of the cavity 35 of the light source 13, a third value which is the pitch D between the light sources 13, and a fourth value which is the thickness T of the light guide member 19, and may satisfy the following mathematical formula 1. $Uni_Min_0.7 = K 1 * (T / D) - K 2 * (B / A) + K 3$
In the mathematical formula, Uni_Min_0.7 is a minimum of 70% of the light uniformity, T is the thickness of the light guide member 19, D is the pitch between the light sources, A is half the maximum width of the cavity of the light source, and B is the height of the cavity. The first constant K1 is a constant multiplied by a value obtained by the thickness T1 of the light guide member 19 and the pitch D between the light sources 13, the second constant K2 is a constant multiplied by a value obtained by the half-width and height of the cavity of the light source 13, and the third constant K3 is a constant value added to a value obtained by the above configurations of the lighting module. When the formula is satisfied, the light uniformity of the lighting module may satisfy 70% or more.
The formula may satisfy at least one or two or more of the following conditions. $0.2 < K 1 * (T / D) < 0.5$ $0.01 < K 2 * (B / A) < 0.3$ $(K 1 * (T / D) + K 2 * (B / A)) < K 3$ $0 < K 2 < K 1$ $K 2 < K 1 < K 3$ $K 1 < K 3 < 2 * K 1$ $2 * K 2 < K 1 < 4 * K 2$ $K 1 < K 3 < 1$ $0 < K 1 < 0.5$ $K 2 < (K 1 - K 2)$ $K 1 * (T / D) > K 2 * (A / B)$
Here, the first constant K1 is the ratio of the thickness T of the light guide member 19 to the distance between the light sources 13. This is a value for compensating for the ratio T/D between the pitches D. For example, when the thickness T of the light guide member 19 is greater than the pitch D between the light sources 13 (D<T), the ratio T/D has a value of 1 or more, for example, 1 to 1.5, and may satisfy Condition 9, and the light uniformity can vary depending on the light beam angle of the light source, that is, the ratio B/A of the cavity. When the thickness T of the light guide member 19 is smaller than the pitch D between the light sources 13 (T<D), the ratio T/D may have a value of 0.5 or more and less than 1, and the light uniformity can vary depending on the directivity angle of the light source 13, that is, the ratio B/A of the cavity. This ratio T/D may satisfy Condition 11-1. $0.5 \leq (T / D) \leq 1.5$
The second constant K2 is a constant for adjusting the beam spread of the light source 13. The cavity ratio B/A may be less than 1, for example, in the range of 0.2 to 0.9. The cavity ratio B/A may satisfy Condition 11-2. $0 < (B / A) < 1$
In Condition 11-2, B < A is satisfied.
The third constant K3 is a uniformity value of light emitted from the lighting module that is greater than or equal to a certain value, regardless of the thickness T of the light guide member 19, the pitch D between light sources, and the half-width A and height B of the cavity. The third constant K3) may satisfy Condition 11-3. $0.4 < K 3 < 1$
More specifically, Condition 11-3 may satisfy: 0.4 < K3 < 0.7.
The first to third constants K1, K2, and K3 have different values, and their ratios may satisfy the following conditions:
$2.1 < K 1 / K 2 < 4.1$ $1 < K 1 / K 3 < 2$
Furthermore, the difference between the calculated values in Conditions 1 and 2 and the value divided by the third constant (K3) may satisfy Condition 12 below:
$1 < (K 1 * (T / D) - K 2 * (B / A)) / K 3 < 2.5$
The following will compare the optical uniformity of samples satisfying the first, second, and third constants K1, K2, and K3 and the above conditions. FIGS. 10a, 10b, and 10c are graphs showing the distribution of light uniformity changes according to the cavity ratio of each light source in the first, second, and third samples of the lighting module according to an embodiment of the invention, and FIG. 11 is a graph comparing the distribution of light uniformity according to the first, second, and third samples of the lighting module according to an embodiment of the invention.
The first sample satisfies the condition: D < T in terms of the pitch D of the light sources 13 and the thickness T of the light guide member 19, the second sample satisfies the condition: D = T, and the third sample satisfies the condition: D > T. The difference between T and D in the first, second, and third samples is 30% or less. Furthermore, the cavity ratio B/A of the light sources in the first, second, and third samples is applied in examples where it increases from 0 to 0.08 and reaches 0.81.
As shown in FIG. 10a, it may be seen that the uniformity of light of the first sample of the lighting module decreases from 79.5% to 71.3% when the ratio of the cavity to the light source B/A changes from 0 to 0.82. As shown in FIG. 10b, it may be seen that the uniformity of light of the second sample of the lighting module decreases from 83% to 76.5% when the ratio of the cavity to the light source B/A changes from 0 to 0.82, and the uniformity of light is 80% or more when the ratio B/A is 0 to 0.48. As shown in FIG. 10c, the third sample of the lighting module shows that when the cavity ratio B/A from the light source changes from 0 to 0.82, the light uniformity decreases from 87.8% to 82.8%, and when the ratio B/A is 0 to 0.5, the light uniformity is 80% or higher.
FIG. 11 is a graph showing the distribution of light uniformity according to the cavity ratio B/A of the first, second, and third samples of the lighting modules of Figs. 10a, 10b, and 10c, and it may be seen that all samples show a value of 70% or higher. In other words, the cavity ratio B/A for a light uniformity of 70% or higher in the first, second, and third samples ranges from 0 to 0.82. Alternatively, it may be seen that the cavity ratio B/A for a light uniformity of 80% or more in the first, second, and third samples ranges from 0 to 0.25. It may be seen that the light uniformity according to the condition 2: 0 < K1*(B/A) < 0.3 and the condition 1: 0.2 < K1*(T/D) < 0.5 is 70% or more based on the cavity ratio B/A. Here, the light uniformity may be obtained as the value of minimum light distribution/minimum light distribution, which is the value obtained by dividing the minimum light intensity by the maximum light intensity on the lighting module.
FIG. 12a, FIG. 12b, and FIG. 12c are graphs showing the distribution of changes in light uniformity according to formula values in the first, second, and third samples of the lighting module according to an embodiment of the invention, and FIG. 13 is a graph comparing the changes in formula values and the cavity ratio of the light source according to the first, second, and third samples of the lighting module according to an embodiment of the invention. Here, the formula values are values obtained by the formula: K1*(T/D) - K2*(B/A) + K3, and the values of the parameters T, D, A, and B and the first, second, and third constants K1, K2, and K3 may be values that satisfy the conditions disclosed above.
The formula values and light uniformity according to the first sample of the lighting module in FIG. 12a are as follows. When the formula value is 0.709, the light uniformity is 71.37%, when the formula value is 0.718, the light uniformity is 71.79%, when the formula value is 0.726, the light uniformity is 71.71%, when the formula value is 0.751, the light uniformity is 76%, and when the formula value is 0.794, the light uniformity may be 79.43%. That is, the deviation between the value obtained by the above formula and the light uniformity may be less than 10%, that is, 5% or less or 3% or less. This shows that the calculated formula value matches the light uniformity, and through this, when the light uniformity is 70% or higher, each parameter T, D, A, and B of the above conditions 1 and 2 may be set to the formula value to 0.7 or higher, and when the light uniformity is 80% or higher, each parameter T, D, A, and B of the above conditions 1 and 2 may be set to the formula value to 0.8 or higher.
In addition, the formula value and light uniformity by the second sample of the lighting module in FIG. 12b are as follows. When the formula value is 0.764, the light uniformity is 76.49%, when the formula value is 0.772, the light uniformity is 76.83%, when the formula value is 0.781, the light uniformity is 78.08%, when the formula value is 0.814, the light uniformity is 83.54%, and when the formula value is 0.849, the light uniformity may be 83.12%. That is, the deviation between the value obtained by the above formula and the light uniformity may be less than 10%, that is, 5% or less or 3% or less. This shows that the calculated formula value matches the light uniformity, and through this, when the light uniformity is 70% or higher, each parameter T, D, A, and B of conditions 1 and 2 may be set to the formula value to 0.7 or higher, and when the light uniformity is 80% or higher, each parameter T, D, A, and B of conditions 1 and 2 may be set to the formula value to 0.8 or higher.
In addition, the formula value and light uniformity by the third sample of the lighting module in FIG. 12c are as follows. When the formula value is 0.818, the light uniformity is 82.68%, when the formula value is 0.827, the light uniformity is 83.17%, when the formula value is 0.835, the light uniformity is 83.77%, when the formula value is 0.860, the light uniformity is 87.67%, and when the formula value is 0.903, the light uniformity may be 87.74%. That is, the deviation between the value obtained by the above formula and the light uniformity may be less than 10%, that is, 5% or less or 3% or less. This shows that the calculated formula value matches the light uniformity, and through this, when the light uniformity is 70% or more, each parameter T, D, A, and B of conditions 1 and 2 may be set so that the formula value is 0.7 or more, and when the light uniformity is 80% or more, each parameter T, D, A, and B of conditions 1 and 2 may be set so that the formula value is 0.8 or more.
As shown in FIG. 13, when comparing the formula values obtained by FIGS. 12a, 12b, and 12c with the values of the cavity ratio of the light source, it may be seen that the formula values of the first, second, and third samples of the lighting module have a change distribution of the formula values within the range of 0.70 to 0.90 when the value of the cavity ratio B/A of the light source changes from 0 to 0.82. In other words, it may be seen that when the value of the cavity ratio B/A of the light source is less than 1, the light uniformity is 70% or more.
FIG. 14a is a graph showing the uniformity E value, the formula value F, and the ratio of the uniformity and the formula value E/F obtained from the first sample of FIGS. 11a and 12a, FIG. 14b is a graph showing the uniformity E value, the formula value F, and the ratio E/F of the uniformity and the formula value obtained from the second sample of FIGS. 11b and 12b, and FIG. 14c is a graph showing the uniformity E value, the formula value F, and the ratio E/F of the uniformity and the formula value obtained from the first sample of FIGS. 11c and 12c. Here, the horizontal axis represents examples in which different values are applied to each parameter A, B, T, and D in each sample.
As shown in FIG. 14a, in the case of the first sample, the uniformity E and the formula value F may be seen to have a difference of less than 10%, that is, a difference of 5% or less or 3% or less, and the ratio E/F of the light uniformity and the formula value may be seen to have substantially the same value. As shown in FIG. 14b and FIG. 14c, in the case of the second and third samples, the uniformity E and the formula value F may be seen to have a difference of less than 10%, that is, a difference of 5% or less or 3% or less, and the ratio E/F of the light uniformity and the formula value may be seen to have substantially the same value.
In this way, the values of Conditions 1 and 2, which are determined by the pitch of the light sources 13 placed within the lighting module, the thickness T of the light guide member 19, and the directivity characteristics of each light source, i.e., the cavity ratio B/A, may be set to 0.70 or higher in the formula, thereby setting the light uniformity of the lighting module to 70% or higher. This may be achieved by selecting values for the parameters T, D, A, and B within the lighting module that match the light uniformity.
The cavity ratio B/A of the light source may be set to a range of 0.5 to 0.7 to increase brightness, and it may be seen that it increases in proportion to the height of the lighting module. While a smaller cavity ratio B/A can improve uniformity, it may be seen that when the thickness of the light guide member is 12 mm or more, the cavity ratio B/A is set to 0.25 to 0.35. Accordingly, to improve uniformity, the cavity ratio B/A of the light source may be set to a range of 0.25 to 0.35, and the cavity ratio B/A of the light source for light distribution may be set to a range of 0.5 to 0.7. Furthermore, in the case of a lighting module with a predetermined cavity ratio B/A, at least one of the thickness T of the light guide member 19 and the pitch D between the light sources 13 may be adjusted to provide a lighting module with a light uniformity of 70% or greater. Furthermore, in the case where the thickness T of the light guide member 19 and the pitch D between the light sources 13 are determined, at least one of the half-width A and height B of the cavity of the light source may be adjusted to provide a lighting module with a light uniformity of 70% or greater.
The light uniformity, when measured as a minimum/maximum value on the lighting module 10, may be calculated as a uniformity that is visible, partially or weakly visible, or not visible due to hot spots emitted from the light sources 13, respectively. For example, when measured as a light uniformity of 90% or greater, the hot spot areas of the light sources 13 are not visible on the lighting module 10. When measured as a light uniformity of 85% or greater, for example, in the range of 85% to 89%, the light sources 13 are partially or weakly visible, and when measured as less than 85%, the light sources 13 are visible.
Tables 1 to 5 and FIG. 15 are data and graphs comparing the light uniformity (minimum/maximum) according to the thickness T1 of the light guide portion 15 and the pitch D1 of the light sources 13 on the lighting module 10 according to an embodiment of the invention. The thickness T1 of the light guide portion 15 was selected from the range of 5 mm to 9 mm, and the pitch D1 between the light sources 13 was selected from the range of 4 mm to 13 mm, and the light uniformity was measured. In addition, if the area of the light source 13 or the hot spot area of the light source 13 is recognized by the light emitted from the light source 13 from the outside, the light uniformity may not be uniform, which may lower the reliability of the lighting module 10. That is, as shown in FIG. 16, a comparative example is shown in which the area of some light sources of the lighting module is exposed by the hot spot. The invention can select the thickness T1 of the light guide portion 15 and the pitch D1 between the light sources 13 that have the optimal light uniformity, in which the light sources 13 are not visible or are weakly visible on the lighting module 10. The pitch D1 value may be obtained as a minimum and a maximum value. [Table 1]

T1 (mm) D1 (mm) Light uniformity (Min/Max) (%)

5 4 92.9%

5 92.1%

6 90.4%

7 87.3%

8 85.4%

9 81.3%

10 77.7%
Table 1 shows that when the thickness T1 of the light guide portion 15 is 5 mm, the light uniformity was measured after increasing the pitch D1 of the light sources 13 from 4 mm to 10 mm. In this case, the pitch D1 of the light sources 13 was measured to have a uniformity of 90% or more in the range of 4 mm to 6 mm, a uniformity of less than 90%, for example, 85% to 89%, in the range of 7 mm to 8 mm, and a uniformity of less than 85%, for example, 76% to 84%, in the range of 9 mm to 10 mm. At this time, the minimum value of the pitch D1 satisfies the condition: T1 - (T1*0.2), and the maximum value may satisfy the condition: T1+(T1*0.6). Here, * in the specification represents multiplication. [Table 2]

T1 (mm) D1 (mm) Light uniformity (Min/Max) (%)

6 5 91.8%

6 90.9%

7 89.2%

8 87.6%

9 83.1%
Table 2 shows that when the thickness T1 of the light guide portion 15 is 6 mm, the light uniformity was measured by increasing the pitch D1 of the light sources 13 from 5 mm to 9 mm. In this case, the pitch D1 of the light sources 13 was measured to have a uniformity of 90% or more in the range of 5 mm to 6 mm, a uniformity of less than 90%, for example, a uniformity of 85% to 89%, and a uniformity of less than 85% in the range of 7 mm to 8 mm. At this time, the minimum value of the pitch D1 satisfies the condition: T1-(T1*0.12), and the maximum value may satisfy the condition: T1+(T1*0.35). [Table 3]

T1 (mm) D1 (mm) Light uniformity (Min/Max) (%)

7 6 92.4%

7 92.0%

8 89.5%

9 88.5%

10 85.4%
Table 3 shows that when the thickness T1 of the light guide portion 15 is 7 mm, the light uniformity was measured by increasing the pitch D1 of the light sources 13 from 6 mm to 10 mm. In this case, the uniformity of the light sources 13 was measured to be 90% or higher when the pitch D1 of the light sources 13 was 7 mm or less, and the uniformity was measured to be less than 90%, for example, 85% to 89%, in the range of 8 mm to 10 mm. At this time, the minimum value of the pitch D1 satisfies the condition: T1-(T1*0.2), and the maximum value may satisfy the condition: T1+(T1*0.3). [Table 4]

T1 (mm) D1 (mm) Light uniformity (Min/Max) (%)

8 7 91.4%

8 90.6%

9 89.5%

10 87.5%

11 85.4%
Table 4 shows that when the thickness T1 of the light guide portion 15 is 8 mm, the light uniformity was measured by increasing the pitch D1 of the light sources 13 from 7 mm to 11 mm. In this case, the uniformity of the light sources 13 was measured to be 90% or higher when the pitch D1 of the light sources 13 was 8 mm or less, and the uniformity was measured to be less than 90%, for example, 85% to 89%, in the range of 9 mm to 11 mm. At this time, the minimum value of the pitch D1 satisfies the condition: T1-(T1*0.2), and the maximum value may satisfy the condition: T1+(T1*0.4). [Table 5]

T1 (mm) D1 (mm) Light uniformity (Min/Max) (%)

9 8 91.4%

9 91.1%

10 89.4%

11 88.6%
Table 5 shows that when the thickness T1 of the light guide portion 15 is 9 mm, the light uniformity was measured by increasing the pitch D1 of the light sources 13 from 8 mm to 11 mm. In this case, the uniformity of the light sources 13 was measured to be 90% or more when the pitch D1 of the light sources 13 was 9 mm or less, and the uniformity was measured to be less than 90%, for example, 85% to 89%, in the range of 10 mm to 11 mm. At this time, the minimum value of the pitch D1 satisfies the condition: T1-(T1*0.15), and the maximum value may satisfy the condition: T1+(T1*0.25).
Using the regression analysis method using the data in Tables 1 to 5, the maximum available pitch of adjacent light sources 13 arranged in a single row to secure a minimum light uniformity Uni_Min90 of 90% may be calculated as follows, and a relationship between the two variables may be derived through this. Here, the maximum available pitch may be the pitch for using the minimum number of light sources within the desired light uniformity. $D 1 \leq K 1 + (K 2 * T 1)$
In Formula 1, K1 is a constant that is constantly added to the (K2*T1) value, and K2 is a constant that reduces the thickness T1 of the light guide portion 15 by a predetermined ratio. Formula 1 calculates the pitch D1 of the light sources 13 to ensure a minimum light uniformity Uni_Min90 of 90%, using the constants K1 and K2 and the thickness T1 of the light guide portion 15. $K 2 < K 1$ $1.1 < K 1 < 1.6$ $0.5 < K 2 < 1$ $1.2 < K 1 / K 2 < 1.7$
Formula 1 may satisfy at least one of Conditions 1 to 4, where K1 is 1.392 and K2 is 0.9102.
When applying Formula 1, the variables for the thickness T1 of the light guide portion 15 and the pitch D1 between adjacent light sources 13 for a minimum light uniformity of 90% may be obtained, as shown in Table 6 below. [Table 6]

T1 (mm) D1 (mm)

5 5.99

6 6.81

7 7.71

8 8.71

9 9.59
Therefore, to achieve a minimum light uniformity of 90%, the pitch D1 between two adjacent light sources 13 arranged in a single row may be 100% or more, for example, between 100% and 110%, of the thickness T1 of the light guide portion 15.
As another example, using the data in Tables 1 to 5, the maximum available pitch between two adjacent light sources 13 arranged in a single row to ensure a minimum light uniformity Uni_Min85 of 85% may be calculated as follows, thereby deriving a relationship between the two variables. Here, the maximum available pitch may be the pitch for using the minimum number of light sources within the desired light uniformity. $D 1 \leq K 3 + (K 4 * T 1)$
In Formula 2, K3 is a constant that is constantly added to the (K4*T1) value, and K2 is a constant that increases the thickness T1 of the light guide portion 15 by a certain ratio. Formula 2 calculates the pitch D1 of the light sources 13 to secure a minimum light uniformity Uni_Min85 of 85% using the constants K3 and K4 and the thickness T1 data of the light guide 13. $K 4 < K 3$ $2 < K 3 < 2.5$ $1 < K 4 < 1.4$ $1.5 < K 3 / K 4 < 2.3$
Formula 1 may satisfy at least one of Conditions 1 to 4. Preferably, K3 is 2.216 and K4 is 1.1267.
When the light uniformity is at least 85%, the parameters of the thickness T1 of the light guide portion 15 and the pitch D1 between the light source 13 may be obtained by applying Formula 2, as shown in Table 7 below. [Table 7]

T1 (mm) D1 (mm)

5 7.93

6 8.93

7 10.01

8 11.22

9 12.42
Therefore, for a light uniformity of at least 85%, the pitch D1 between the light sources 13 may be 135% or more, for example, in the range of 135% to 150%, of the thickness T1 of the light guide portion 15. If the relationship between the thickness T1 of the light guide portion 15 and the pitch D1 between the two light sources 13 arranged in one row is established as in Formulas 1 and 2, and if the thickness T1 of the light guide portion 15 and the light uniformity are determined, the pitch D1 between the light sources 13 may be set. Alternatively, if the relationship between the thickness T1 of the light guide portion 15 and the pitch D1 between the two light sources 13 arranged in one row is established as in Formulas 1 and 2, and if the pitch D1 between the light sources 13 and the light uniformity are determined, the thickness T1 of the light guide portion 15 may be set. Using Formulas 1 and 2, the lighting module can achieve a light uniformity of 85% or more by calculating and installing each variable as shown in Formulas 1 and 2. Accordingly, the optical reliability of the lighting module 10 may be improved.
As shown in FIG. 17, the lighting device 100A or the lighting module 10 includes an optical lens 51, which may be positioned above the lighting module 10. The optical lens 51 may be positioned on the diffusion layer 17 of the lighting module 10. The optical lens 51 may include an incident surface 53 and an exit surface 55. A portion of the incident surface 53 faces the lighting module 10, and light emitted from the lighting module 10 is incident thereon. The incident surface 53 may be a concave curved surface, a convex curved surface, or a horizontal plane in the short-axis direction X. The exit surface 55 can refract light incident through the incident surface 53 when it is guided therethrough. The exit surface 55 can irradiate or concentrate parallel light. The exit surface 55 may be provided in a convex hemispherical shape or a shell shape. As another example, the exit surface 55 may include a Fresnel lens pattern. The optical lens 51 may be configured as a condenser lens, a parallel light lens, a collimator lens, or a Fresnel lens.
The incident surface 53 of the optical lens 51 is disposed on the upper portion of the light guide portion 15 and can face the upper surface of the diffusion layer 17. The incident surface 53 may be spaced apart from the upper surface of the diffusion layer 17. Since the incident surface 53 of the optical lens 51 is spaced apart from the upper surface of the diffusion layer 17, light diffused through the diffusion layer 17 may be incident on a wide area of the incident surface 53. The distance G1 between the incident surface 53 and the diffusion layer 17 may be 0.01 mm or more, for example, in the range of 0.01 mm to 0.5 mm. Here, the width D2 of the incident surface 53 is the width of the lower surface of the optical lens 51, may be larger than the upper width W1 of the lighting module 10, and may be 1.5 times or more, for example, in the range of 1.5 to 10 times or 2 to 10 times the upper width W1 of the lighting module 10. The maximum width D2 of the optical lens 51 in the first direction X may be smaller than or different from the height. When the maximum width D2 of the optical lens 51 in the first direction X is greater than the height, the brightness may decrease and the line width may increase. When the maximum width D2 of the optical lens 51 in the first direction X is less than the height, the brightness may increase and the line width may decrease. Accordingly, the maximum width D2 and the height of the optical lens 51 in the first direction X may be adjusted to suit the light distribution image.
The length of the optical lens 51 in the second direction Y may be equal to or greater than the length of the lighting module 10. Accordingly, when viewed from the outside of the lighting device 100, the surface of the optical lens 51 may be exposed, and the upper structure of the lighting module 10 may not be exposed. The optical lens 51 may include a light-transmitting material, such as PC, OPS, PMMA, PVC, or the like. The optical lens 51 may include a resin material, such as silicone or epoxy, or a thermosetting material. The refractive index of the optical lens 51 may range from 1.4 to 1.6. Since the optical lens 51 has the above-described material and refractive index, it can refract incident light toward a target without loss. The optical lens 51 can emit light as a surface having a line width of 30 mm or less in the first direction X and a long length in the second direction Y. Accordingly, the external image of the lighting device 100 may be provided as an image having the line width.
The optical lens 51 may have a concave curved shape or a convex curved shape relative to the longitudinal direction Y, or may have one end and the other end of the optical lens 51 twisted in opposite directions. The incident surface 53 of the optical lens 51 may have a convex surface having a first radius of curvature in the short-axis direction, i.e., the first direction X.
The lighting device 100 may include at least one or both of a housing (not shown) and a reflective member 40 for coupling to a moving body such as a vehicle. The housing may support the lighting module 10 and the reflective member 40. The housing may be a heat dissipation member. The reflective member 40 includes an insertion hole R11 therein, and first and second reflective portions 42 and 43 on both sides of the insertion hole R11, and the first and second reflective portions 42 and 43 have the insertion hole R11 therein and may protrude toward the incident surface 53. The width of the insertion hole R11 in the first direction X may be smaller than the length in the second direction Y. The width of the insertion hole R11 in the first direction X may correspond to the width of the light guide part 15 in the first direction X, and the length of the second direction Y may correspond to the length of the light guide part 15 in the second direction. The insertion hole R11 has a line shape in a top view.
The first and second reflective portions 42 and 43 may be arranged along the longitudinal direction or the second direction Y of the light guide part 15. The first and second reflective portions 42 and 43 may extend to both sides of the insertion hole R11. Accordingly, the first and second reflective portions 42 and 43 may reflect light incident on the side of the light guide part 15 and re-incident it into the light guide part 15. The first and second reflective portions 42 and 43 may be connected to each other at both ends in the longitudinal direction of the light guide portion 15. The longitudinal direction of the light guide portion 15 is the long side direction, and the width direction is the short side direction.
The reflective member 40 includes a concavely sunken air gap C0, and the air gap C0 may include a region lower than the incident surface 53 of the optical lens 51. The air gap C0 may be provided with a center distance of a distance G1 between the diffusion layer 17 and the incident surface 53. The distance G1 is a distance spaced in the vertical direction, and the width of the region having the distance G1 may be smaller than the width of the lower surface of the diffusion layer 17 in the first direction X, and the length may be equal to the length of the diffusion layer 17 in the second direction Y. The upper ends of the first and second reflective portions 42 and 43 may be positioned higher than the upper ends of the light guide portion 15. Accordingly, the first and second reflective portions 42 and 43 may reflect light leaking through the side surfaces of the light guide portion 15, thereby improving the light extraction efficiency of the lighting module 10.
The upper ends of the first and second reflective portions 42 and 43 of the reflective member 40 may be positioned higher than the upper ends of the diffusion layer 17. Accordingly, the first and second reflective portions 42 and 43 reflect light incident through the side surfaces of the light guide portion 15 and enable light to be emitted through the side surfaces of the diffusion layer 17. Furthermore, the upper surfaces of the first and second reflective portions 42 and 43 may reflect light emitted through the diffusion layer 17 toward the incident surface 53 of the optical lens 51.
The reflective member 40 includes first and second lens support portions 45 and 46, and the first and second support portions 45 and 46 may be arranged along the outer edge of the optical lens 51. The first and second support portions 45 and 46 have a concave stepped structure inward from the upper end thereof, and the stepped structure supports the outer edge of the optical lens 51. The upper ends of the first and second support portions 45 and 46 may be arranged higher than the lower end or outer edge of the incident surface 53 of the optical lens. Accordingly, the lower end edge of the optical lens 51 may be coupled along the inner upper end of the first and second support portions 45 and 46. At this time, the lower end edge of the optical lens 51 may be bonded to the stepped structure with an adhesive. The height of the stepped structure may be less than the height to the top of the first and second support portions 45 and 46 and greater than the height to the upper surface of the diffusion layer 17. Since the height from the substrate 11 to the stepped structure is positioned higher than the upper surface of the diffusion layer 17, the incident surface 53 of the optical lens 51 and the diffusion layer 17 may be separated.
The substrate 11 may be adhesively bonded to the housing or to the reflective member 40. The reflective member 40 may prevent the substrate 11 from being detached or tilted.
FIG. 18 is a plan view of a vehicle to which a lighting device according to an embodiment is applied, and FIG. 19 is a drawing illustrating an example of a taillight of the vehicle of FIG. 18.
Referring to FIGS. 18 and 19, a front lamp 2100 in a mobile or vehicle 2000 may include one or more lighting modules, and the driving timing of these lighting modules may be individually controlled to provide not only a function as a conventional headlight, but also additional functions such as a welcome light or a celebration effect when a driver opens a vehicle door. The lamp may be applied to a daytime running light, a high beam, a low beam, a fog light, or a turn signal. A tail lamp 2200 and 800 in a vehicle 2000 may be arranged as a plurality of lamp units 810, 812, 814, and 816 supported by a housing. For example, the lamp units 810, 812, 814, and 816 may include a first lamp unit 810 disposed on the outside, a second lamp unit 814 disposed on the inner periphery of the first lamp unit 810, and third and fourth lamp units 814 and 816 disposed on the inside of the second lamp unit 814, respectively. The first to fourth lamp units 810, 812, 814, and 816 may selectively apply the lighting device disclosed in the embodiment, and a red lens cover or a white lens cover may be disposed on the outside of the lighting device for the lighting characteristics of the lamp unit 810, 812, 814, and 816. The lighting device disclosed in the embodiment applied to the lamp units 810, 812, 814, and 816 may emit surface light with a uniform distribution.
The first and second lamp units 810 and 812 may be provided in at least one of a curved shape, a straight shape, an angular shape, an inclined shape, or a planar shape, or a mixed structure thereof. The first and second lamp units 810 and 812 may be arranged one or more in each tail light. The first lamp unit 810 may be provided as a tail light, the second lamp unit 812 may be provided as a brake light, the third lamp unit 814 may be provided as a reverse light, and the fourth lamp unit 816 may be provided as a turn signal lamp. The lighting device 100 disclosed above may be arranged in multiple units as daytime running lights at the front of the vehicle 2000, and may be provided in a line shape each having a convex curve. These lighting lamps can provide higher brightness in the rearward direction than in the side direction, allowing them to comply with lighting regulations for stop lamps or tail lamps, etc.
Features, structures, effects, and the like described in the embodiments are included in at least one embodiment of the invention, and are not necessarily limited to only one embodiment. Furthermore, the features, structures, effects, and the like illustrated in each embodiment may be combined or modified for other embodiments by a person having ordinary knowledge in the field to which the embodiments belong. Accordingly, contents related to such combinations and modifications should be construed as being included in the scope of the invention. In addition, although the examples have been described above, these are only examples and do not limit the invention, and those of ordinary skill in the field to which the invention pertains are illustrated above within the scope not departing from the essential characteristics of the present embodiment. It will be seen that various modifications and applications that have not been made are possible. For example, each component specifically shown in the embodiment may be modified and implemented. And differences related to these modifications and applications should be construed as being included in the scope of the invention defined in the appended claims.

Claims

A lighting module comprising:
a substrate;

a plurality of light sources arranged on the substrate; and

a light guide member including a light guide portion sealing the plurality of light sources on the substrate and a diffusion layer disposed on the light guide portion,

wherein each of the plurality of light sources includes a reflective body, a concave cavity on an upper surface of the reflective body, and a light emitting chip disposed on a bottom of the cavity,

wherein 1/2 of a maximum width of the cavity is A,

wherein a height of the cavity is B,

wherein a pitch between adjacent light sources is D,

wherein a thickness of the light guide member is T,

wherein the following formula is satisfied: $Uni_Min_0.7 = K 1 \times (T / D) - K 2 \times (B / A) + K 3,$

wherein Uni_Min_0.7 represents a minimum light uniformity of 70 percent on the light guide member,

wherein B is smaller than A, and

wherein K1, K2, and K3 are different constants each having a value greater than 0 and less than 1.
The lighting module of claim 1,
wherein the following condition is satisfied: $K 2 < K 1 .$
The lighting module of claim 1,
wherein the following condition is satisfied: $K 2 < K 1 < K 3 .$
The lighting module of any one of claims 1 to 3,
wherein the following condition is satisfied: $2.1 < K 1 / K 2 < 4.1 .$
The lighting module of claim 4,
wherein the following condition is satisfied: $1 < K 1 / K 3 < 2 .$
The lighting module of claim 5,
wherein the following condition is satisfied: $1 < (K 1 \times (T / D) - K 2 \times (B / A)) / K 3 < 2.5 .$
The lighting module of any one of claims 1 to 3,
wherein the following condition is satisfied: $0.2 < K 1 \times (T / D) < 0.5 .$
The lighting module of any one of claims 1 to 3,
wherein the following condition is satisfied: $0.01 < K 2 \times (B / A) < 0.3 .$
The lighting module of claim 4,
wherein the maximum width of the cavity of the light source is a width in a first direction.
A lighting module comprising:
a substrate having a length in a second direction greater than a width in a first direction;

a plurality of light sources arranged in a single row on the substrate;

a light guide portion sealing the plurality of light sources on the substrate; and

a diffusion layer disposed on the light guide portion,

wherein a thickness of the light guide portion is greater than a thickness of the diffusion layer,

wherein the thickness of the light guide portion is T1,

wherein a pitch between adjacent light sources is D1,

wherein the following formula is satisfied: $D 1 \leq K 1 + (K 2 \times T 1),$

wherein K1 is a constant added to a value of (K2 × T1), and

wherein K2 is a constant for reducing the thickness of the light guide portion by a predetermined ratio and has a value smaller than K1.
The lighting module of claim 10,
wherein the constants K1 and K2 satisfy the following conditions: $1.1 < K 1 < 1.6,$ $0.5 < K 2 < 1,$ and $1.2 < K 1 / K 2 < 1.7 .$
The lighting module of claim 10 or 11,
wherein the pitch D1 between adjacent light sources is in a range of 100 percent to 130 percent relative to the thickness T1 of the light guide portion, and

wherein the pitch between adjacent light sources is in a range of 5 mm to 9 mm.
A lighting device comprising:
a substrate having a length in a second direction greater than a width in a first direction;

a plurality of light sources arranged on the substrate in the second direction;

a light guide member including a light guide portion sealing the plurality of light sources on the substrate and a diffusion layer disposed on the light guide portion; and

a reflective member disposed on both sides of the light guide member,

wherein each of the plurality of light sources includes a reflective body, a concave cavity on an upper surface of the reflective body, and a light emitting chip disposed on a bottom of the cavity,

wherein 1/2 of a maximum width of the cavity is A,

wherein a height of the cavity is B,

wherein a pitch between adjacent light sources is D,

wherein a thickness of the light guide member is T,

wherein the following formula is satisfied: $Uni_Min_0.7 = K 1 \times (T / D) - K 2 \times (B / A) + K 3,$

wherein Uni_Min_0.7 represents a minimum light uniformity of 70 percent on the light guide member,

wherein B is smaller than A, and

wherein K1, K2, and K3 are different constants each having a value less than 1.
The lighting device of claim 13,
wherein a value of a ratio B/A of the cavity is in a range of 0.25 to 0.35.
The lighting device of claim 13,
wherein a value of a ratio B/A of the cavity is in a range of 0.5 to 0.7.