KR102231644B1 - Light emitting unit - Google Patents

Abstract

The embodiment includes a plurality of light emitting device arrays disposed on a circuit board and emitting light in a first wavelength region; And a wavelength conversion member disposed to be spaced apart from the plurality of light emitting devices, excited by light in the first wavelength region to emit light in the second wavelength region, and including a plurality of regions having different thicknesses. Provides.

Description

Light emitting unit {LIGHT EMITTING UNIT}

The embodiment relates to a light-emitting unit, and more particularly, to a light-emitting unit capable of adjusting a color temperature.

Group 3-5 compound semiconductors such as GaN and AlGaN are widely used in optoelectronics and electronic devices due to their many advantages, such as having a wide and easily adjustable band gap energy.

In particular, light emitting devices such as light emitting diodes and laser diodes using a group 3-5 or group 2-6 compound semiconductor material of semiconductors are developed in thin film growth technology and device materials, such as red, green, blue, and ultraviolet rays. Various colors can be implemented, and efficient white light can be realized by using fluorescent materials or by combining colors. Low power consumption, semi-permanent life, fast response speed, safety, and environment compared to conventional light sources such as fluorescent lamps and incandescent lamps. It has the advantage of affinity.

Therefore, the transmission module of the optical communication means, a light-emitting diode backlight that replaces the Cold Cathode Fluorescence Lamp (CCFL) that constitutes the backlight of the LCD (Liquid Crystal Display) display, and white light that can replace a fluorescent lamp or incandescent light bulb. Applications are expanding to diode lighting devices, automobile headlights and traffic lights.

The light emitting device emits light having energy determined by an energy band inherent to a material constituting the active layer by meeting each other with electrons injected through the first conductivity-type semiconductor layer and holes injected through the second conductivity-type semiconductor layer. Light emitted from the active layer may vary depending on the composition of the material constituting the active layer, and may be blue light, ultraviolet (UV), deep ultraviolet (Deep UV), or light in a different wavelength range.

In the light emitting device or the light emitting device package, a phosphor is included in a film type or a molding part, and the light in the first wavelength region emitted from the light emitting device excites the phosphor, and light in the second wavelength region may be emitted from the phosphor. .

However, the conventional light emitting device or light emitting device package has the following problems.

When a light emitting device is used as a light source of a lighting device, in some cases, the color temperature needs to be changed according to the surrounding environment. For example, even if the same lighting device is used, it is necessary to warm the color temperature outdoors and cool the color temperature indoors. If the same light emitting device or light emitting device package is used in the currently used lighting device, it is difficult to change the color temperature.

The embodiment attempts to vary the color temperature of light emitted from a light source according to the use environment of the lighting device.

The embodiment includes a plurality of light emitting device arrays disposed on a circuit board and emitting light in a first wavelength region; And a wavelength conversion member disposed to be spaced apart from the plurality of light emitting devices, excited by light in the first wavelength region to emit light in the second wavelength region, and including a plurality of regions having different thicknesses. Provides.

The wavelength conversion member may include a base film and a phosphor layer disposed on the base film.

The thickness of the phosphor layer may be constant in a direction parallel to the arrangement direction of the plurality of light emitting device arrays.

The thickness of the phosphor layer may not be constant in a direction crossing the arrangement direction of the plurality of light emitting device arrays.

The thickness of the phosphor layer may change gradually.

The thickness of the phosphor layer can be varied in a stepwise fashion.

The wavelength conversion member may be linearly moved in a direction crossing the light emitting device array.

The wavelength conversion member may rotate with respect to the light emitting device array.

The rotation axis of the wavelength conversion member may be non-overlapping with the center of each light emitting device.

In the light source unit according to the embodiment, according to the movement or rotation of the wavelength conversion unit, the amount of light emitted when the phosphor layer is excited may vary, and thus the color temperature of the light emitted from the light source unit may vary.

1 is a side cross-sectional view of a light emitting unit according to an embodiment,
2 is a view showing an embodiment of the wavelength conversion member of FIG. 1,
3A and 3B are views showing another embodiment of the wavelength conversion member of FIG. 1,
4A to 4C are diagrams showing the configuration of the wavelength conversion member of FIG. 2 in detail,
5A to 5C are diagrams showing the configuration of the wavelength conversion member of FIG. 3 in detail,
6 is a view showing an embodiment of a lighting device including a light emitting device.

Hereinafter, embodiments of the present invention capable of realizing the above object will be described with reference to the accompanying drawings.

In the description of the embodiment according to the present invention, in the case where it is described as being formed in "on or under" of each element, the upper (upper) or lower (lower) (on or under) includes both elements in direct contact with each other or in which one or more other elements are indirectly formed between the two elements. In addition, when expressed as “on or under”, it may include not only an upward direction but also a downward direction based on one element.

1 is a side cross-sectional view of a light emitting unit according to an embodiment, FIG. 2 is a view showing an embodiment of the wavelength conversion member of FIG. 1, and FIGS. 3A and 3B are views showing another embodiment of the wavelength conversion member of FIG. 1 It is a drawing.

As shown in FIG. 1, the light emitting unit according to the embodiment includes a light emitting device package 200 on a circuit board 100 and a wavelength conversion member 300 disposed to be spaced apart from the light emitting device package 200. Done.

The circuit board 100 may be a printed circuit board or a flexible printed circuit board (FPCB), and the light emitting device package 200 is driven by receiving current from the printed circuit board 100 described above. In addition, the wavelength conversion member 300 includes a phosphor 330.

The wavelength converting member 300 may have uneven thickness and may be changed. FIG. 2 is a side view of the wavelength converting member 300 of FIG. 1 in a direction'I'. In FIG. 2, the thickness of the wavelength conversion member 300 is different in the three regions (A, B, C) of the wavelength conversion member 300, and thus the number of phosphors 330 disposed in the three regions (A, B, C) It can also be different.

3A and 3B, the wavelength conversion member 400 includes a central axis 410 and a phosphor layer 420 disposed around the central axis 410, and the central axis 410 is It may be a base film supporting the phosphor layer 420.

3B is a side view of the wavelength conversion member 400 of FIG. 3A in a direction'J'. Since the thickness of the phosphor layer 420 disposed around the central axis 410 that is the base film in FIG. 3B is not constant, the number of phosphors 430 disposed in each region of the wavelength conversion member 400 may be different. .

4A to 4C are diagrams showing the configuration of the wavelength conversion member of FIG. 2 in detail.

The light source unit of FIG. 4A includes a circuit board, a light emitting device package, and a wavelength conversion member. The circuit board may include a conductive layer 110 and an insulating layer 120, and the light emitting device package is disposed on the circuit board 200, and the light emitting device 210, the wire 250, and the molding part 250 It can be made, including.

The light emitting device 210 may be, for example, a light emitting diode. The light emitting device 210 includes an undoped semiconductor layer (un-GaN), a first conductivity type semiconductor layer (n-GaN), an active layer (MQW), and a second conductivity type semiconductor layer (p) on a substrate made of sapphire or the like. -GaN) in which a light emitting structure is formed, and the first and second electrodes are disposed on the first conductive semiconductor layer and the second conductive semiconductor layer, respectively, or a vertical light emitting device or a flip chip It may be a light emitting device.

The light emitting device 210 may be electrically connected to the conductive layer 110 of the circuit board through a wire 250. A molding part 270 is formed around the light emitting device 210 to protect the light emitting device 210 and the wire 250.

A wavelength conversion member 300 is disposed on a light emitting device array in which a plurality of light emitting device packages 200 are disposed on the circuit board 100 described above, and the wavelength conversion member includes a base film 310 and a phosphor 330. It may be formed by including the phosphor layer 320 to include.

The base film 310 may be spaced apart from the upper part of the molding part 270 by a predetermined distance d. If the above-described separation distance d is secured, the molding part 270 when the wavelength conversion member 300 moves. May not be in contact with.

The base film 310 is made of a light-transmitting material and may support the phosphor layer 320. The phosphor layer 140 includes the phosphor 330, but may diffuse light emitted from the light emitting device 210.

As the main material of the phosphor layer 320, a resin (oligomer type) containing urethane acrylate oligomer as a main material may be used. For example, a mixture of a synthetic oligomer, urethane acrylate oligomer, and a polyacrylic polymer type may be used. The phosphor layer 320 may further include a monomer in which isobornyl acrylate (IBOA), hydroxylpropyl acrylate (HPA), 2-hydroxyethyl acrylate (2-HEA), etc., which are low-boiling dilution-type reactive monomers, are mixed in the above-described composition, and as an additive. Photoinitiators (such as 1-hydroxycyclohexyl phenyl-ketone) or antioxidants can be mixed.

More specifically, the phosphor layer 320 may be made of a synthetic resin including a mixture of an oligomer and a polymer type, and in particular, 20 to 42% of a mixture of an oligomer and a polymer type, and 30 to 63% of a monomer , It may include a composition formed with a composition of 1.5 to 6% of the additive. At this time, the oligomer and the polymer resin may be formed of a mixture of 10 to 21% of urethane achelate oligomer and 10 to 21% of polyacrylic. In addition, the monomer is a low boiling point dilute reactive monomole, and is formed from a mixture of IBOA (isobornyl Acrylate) 10 to 21%, HPA (Hydroxypropyl Acrylate) 10 to 21%, and 2-HEA (2-Hydroxyethyl Acrylate) 10 to 21%. The additive may be a mixture capable of performing a function of initiating photoreactivity by adding 1 to 5% of a photoinitiator, and improving the yellowing phenomenon by adding 0.5 to 1% of an antioxidant.

The phosphor layer 320 using the above-described composition may be manufactured by the following process. The phosphor layer 320 uses urethane acrylate oligomer as a main material, and is blended with a polymer type, which is polyacryl, at a UV curing wavelength of 300 to 350 μm. Main reaction, using a mercury lamp and a metal (gallium) lamp to adjust the curing balance with the general oligomer type by injecting _{N 2 at a wavelength of 400㎛ and when curing the polymer type} Thus, it is flexible, has excellent adhesion, and maintains the refractive index of the PMMA light guide plate, and overcomes the limitations of the light guide plate.

In particular, if nitrogen purging is not performed when mixing polymer and oligomer, surface wrinkles and cracks may occur due to internal hardening and surface hardening balance, so the characteristic of this invention is nitrogen purging. By doing so, it is more preferable to enable rapid hardening even in general metal halides.

Although not shown, the phosphor layer 320 may include beads to diffuse light emitted from the light emitting device 210 in addition to the above-described composition, and a pattern is formed on the surface of the phosphor layer 320 It could be.

The phosphor layer 320 has a constant thickness in a direction parallel to the arrangement direction of the plurality of light emitting devices 210 as shown in FIG. 4A, but the arrangement direction of the plurality of light emitting devices 210 array as shown in FIG. 4B The thickness in the direction intersecting with may not be constant. Here, the crossing direction may not necessarily be perpendicular to the arrangement direction of the light emitting device 210 array.

4B is a side view of the wavelength conversion member of FIG. 4A in a direction'K'. Although the thickness of the base film 310 of the wavelength conversion member is constant, the thickness of the phosphor layer 320 may be different from the thickness t _L in the first direction and the thickness t _R in the second direction.

In addition, the embodiment shown in FIG. 4C is a side view of another embodiment of the wavelength conversion member of FIG. 4A in the'K' direction. In the embodiment shown in FIG. 4B, the thickness of the phosphor layer 320 is in the first direction. In the embodiment shown in FIG. 4C, which gradually increases from the thickness t _{L to the thickness t R} in the second direction, the thickness _{of the phosphor layer 320 is from the thickness t L} in the first direction to the second As the thickness t _R in the direction increases, the surface of the phosphor layer 320 is stepped by increasing stepwise.

That is, in FIG. 4C, the phosphor layer 320 includes three regions (R ₁ , R ₂ , R ₃ ), and the thickness of each region (R ₁ , R ₂ , R _{3 ) (t 1} , t ₂ , t ₃ ) can also be different.

In the embodiment shown in FIGS. 4B and 4C, the wavelength conversion member 300 can be moved in the direction indicated by an arrow, that is, it can be moved in a direction crossing the arrangement direction of the array of light emitting elements 210 of FIG. 4A. .

Accordingly, when light is emitted from the light emitting device 210 in FIGS. 4B and 4C, the number or density of the phosphors 330 in the region where the above-described light travels may be different according to the movement of the wavelength conversion member 300. . Therefore, when the phosphor layer 320 is moved, the frequency at which the phosphor 330 is excited by the light in the first wavelength region emitted from the light emitting device 210 may vary, and thus the second emitted from the phosphor layer 330 The amount of light in the wavelength region may vary.

As described above, according to a change in the position of the wavelength conversion unit in the light source unit according to the embodiments, the amount of light emitted by the phosphor layer may be excited, and thus the color temperature of the light emitted from the light source unit may vary.

5A to 5C are diagrams showing the configuration of the wavelength conversion member of FIG. 3 in detail.

The configurations of the light emitting device 210, the conductive layer 110 and the insulating layer 120 constituting the circuit board are the same as those of the embodiments shown in FIGS. 4A to 4C, but the configuration of the wavelength conversion member is different.

The wavelength conversion member is composed of a central axis 410 and a phosphor layer 420 disposed around the central axis 410, the central axis 410 may be a base film supporting the phosphor layer 420, the center The phosphor layer 420 may also rotate according to the rotation of the shaft 410.

5B is a side view of the wavelength conversion member 400 of FIG. 5A in the direction'L'. Since the thickness of the phosphor layer 420 disposed around the central axis 410 that is the base film in FIG. 5B is not constant, the number of phosphors 430 disposed in each region of the wavelength conversion member may be different.

That is, the phosphor layer 420 has a constant thickness in a direction parallel to the arrangement direction of the plurality of light-emitting elements 210 as shown in FIG. 5A, but as shown in FIG. 5B, The thickness in the direction crossing the arrangement direction may not be constant. Here, the crossing direction may not necessarily be perpendicular to the arrangement direction of the light emitting device 210 array.

In FIG. 5B, the thickness of the phosphor layer 420 of the wavelength conversion member may be a radius r, and the radius r may not be constant. Then, the center (C ₂₎ is a light emitting element 210, there each center may be (C ₁₎ and a non-overlapping, that is, the respective centers of the light-emitting element 210 (C _1), the axis of rotation (410 of the rotating shaft 410 ), the number of phosphors 430 to which the light emitted from the light emitting device 210 reaches may be different according to the rotation of the rotation axis 410 because it does not coincide in the vertical direction with the center (C _{2 ).}

In addition, the embodiment shown in FIG. 5C is a side view of another embodiment of the wavelength conversion member of FIG. 5A in the'L' direction. In the embodiment shown in FIG. 5B, the radius r of the phosphor layer 320 gradually changes. Thus, in the embodiment shown in FIG. 5C, the thickness of the phosphor layer 420 is changed in a stepwise manner, so that the surface of the phosphor layer 420 is stepped.

That is, in FIG. 5C, the phosphor layer 420 may include four regions R ₁ , R ₂ , R ₃ , and R ₄ having _{different radii (r 1} , r ₂ , r ₃ , and r _{4 ).} In addition, the center (C _{2 ) of the rotation shaft 410 may be non-overlapping with the center (C 1} ) of each of the light emitting elements 210 may be the same as the embodiment of FIG. 5B.

In the embodiment shown in FIGS. 5B and 5C, the wavelength conversion member can be rotated in the direction shown by the arrow, and thus, when light is emitted from the light emitting element 210, the above-described light is emitted according to the rotation of the wavelength conversion member. The number or density of the phosphors 430 in the moving region may be different.

Therefore, when the phosphor layer 420 is rotated, the frequency at which the phosphor 430 is excited by light in the first wavelength region emitted from the light emitting device 210 may be changed, and thus the second emitted from the phosphor layer 430 The amount of light in the wavelength region may vary.

As described above, according to the rotation of the wavelength conversion unit in the light source unit according to the embodiments, the amount of light emitted when the phosphor layer is excited may be different, and thus the color temperature of light emitted from the light source unit may vary.

The above-described light source unit may be used as a backlight unit of an image display device or a light source of a lighting device. Hereinafter, a lighting device in which the above-described light source unit is disposed will be described.

6 is a view showing an embodiment of a lighting device in which a light source unit is disposed.

The lighting device according to the present embodiment may include a cover 1100, a light source module 1200, a radiator 1200, a power supply unit 1600, an inner case 1700, and a socket 1800. In addition, the lighting device according to the embodiment may further include at least one of the member 1300 and the holder 1500, and the light source module 1200 may be a light source unit according to the above-described embodiments.

The cover 1100 has a shape of a bulb or a hemisphere, is hollow, and may be provided in an open shape. The cover 1100 may be optically coupled to the light source module 1200. For example, the cover 1100 may diffuse, scatter, or excite light provided from the light source module 1200. The cover 1100 may be a kind of optical member. The cover 1100 may be coupled to the radiator 1200. The cover 1100 may have a coupling portion coupled to the radiator 1200.

A milky white paint may be coated on the inner surface of the cover 1100. The milky white paint may include a diffuser that diffuses light. The surface roughness of the inner surface of the cover 1100 may be greater than the surface roughness of the outer surface of the cover 1100. This is to allow the light from the light source module 1200 to be sufficiently scattered and diffused to be emitted to the outside.

The material of the cover 1100 may be glass, plastic, polypropylene (PP), polyethylene (PE), polycarbonate (PC), or the like. Here, polycarbonate is excellent in light resistance, heat resistance, and strength. The cover 1100 may be transparent or opaque so that the light source module 1200 can be seen from the outside. The cover 1100 may be formed through blow molding.

The light source module 1200 may be disposed on one surface of the radiator 1200. Accordingly, heat from the light source module 1200 is conducted to the radiator 1200. The light source module 1200 may include a light emitting device package 1210, a connection plate 1230, and a connector 1250.

The member 1300 is disposed on the upper surface of the radiator 1200 and has guide grooves 1310 into which a plurality of light emitting device packages 1210 and a connector 1250 are inserted. The guide groove 1310 corresponds to the substrate and the connector 1250 of the light emitting device package 1210.

The surface of the member 1300 may be coated or coated with a light reflective material. For example, the surface of the member 1300 may be coated or coated with a white paint. The member 1300 reflects light reflected on the inner surface of the cover 1100 and returned toward the light source module 1200 toward the cover 1100. Therefore, it is possible to improve the light efficiency of the lighting device according to the embodiment.

The member 1300 may be made of an insulating material, for example. The connection plate 1230 of the light source module 1200 may include an electrically conductive material. Accordingly, electrical contact may be made between the radiator 1200 and the connection plate 1230. The member 1300 is made of an insulating material to block an electrical short between the connection plate 1230 and the radiator 1200. The radiator 1200 receives heat from the light source module 1200 and heat from the power supply unit 1600 to radiate heat.

The holder 1500 blocks the receiving groove 1919 of the insulating part 1710 of the inner case 1700. Accordingly, the power supply unit 1600 accommodated in the insulating unit 1710 of the inner case 1700 is sealed. The holder 1500 has a guide protrusion 1510. The guide protrusion 1510 has a hole through which the protrusion 1610 of the power supply unit 1600 passes.

The power supply unit 1600 processes or converts an electrical signal provided from the outside and provides it to the light source module 1200. The power supply unit 1600 is accommodated in the storage groove 1719 of the inner case 1700 and is sealed inside the inner case 1700 by the holder 1500. The power supply unit 1600 may include a protrusion 1610, a guide unit 1630, a base 1650, and an extension 1670.

The guide part 1630 has a shape protruding outward from one side of the base 1650. The guide part 1630 may be inserted into the holder 1500. A number of parts may be disposed on one surface of the base 1650. A number of components include, for example, a DC converter for converting AC power provided from an external power source to DC power, a driving chip for controlling the driving of the light source module 1200, and an ESD for protecting the light source module 1200. (ElectroStatic discharge) may include a protection element, but is not limited thereto.

The extension part 1670 has a shape protruding outward from the other side of the base 1650. The extension part 1670 is inserted into the connection part 1750 of the inner case 1700 and receives an electrical signal from the outside. For example, the extension part 1670 may be provided equal to or smaller than the width of the connection part 1750 of the inner case 1700. Each end of the "+ wire" and "- wire" may be electrically connected to the extension part 1670, and the other end of the "+ wire" and "- wire" may be electrically connected to the socket 1800. .

The inner case 1700 may include a molding unit together with the power supply unit 1600 therein. The molding part is a part where the molding liquid is hardened, and allows the power supply part 1600 to be fixed inside the inner case 1700.

Although the embodiments have been described above, these are only examples and do not limit the present invention, and those of ordinary skill in the field to which the present invention belongs are not exemplified above without departing from the essential characteristics of the present embodiment. It will be seen that various modifications and applications are possible. For example, each component specifically shown in the embodiment can be modified and implemented. And differences related to these modifications and applications should be construed as being included in the scope of the present invention defined in the appended claims.

100: circuit board 110: conductive layer
120: insulating layer 200: light emitting device package
210: light-emitting element 250: wire
270: molding part 300, 400: wavelength conversion member
310, 410: base film 320, 420: phosphor layer
230, 330: phosphor

Claims (9)

A plurality of light emitting device arrays disposed on the circuit board and emitting light in the first wavelength region; And
And a wavelength conversion member disposed to be spaced apart from the plurality of light-emitting devices and excited by light in the first wavelength region to emit light in a second wavelength region,
The wavelength conversion member includes a base film forming a central axis and a phosphor layer disposed around the base film,
The central axis is disposed in a direction parallel to the arrangement direction of the circuit board and the light emitting device,
The phosphor layer rotates according to the rotation of the central axis,
The central axis is non-overlapping in a direction perpendicular to the center of each light emitting device,
The thickness of the phosphor layer is different according to the arrangement direction from the central axis. delete delete delete delete delete delete delete delete

Images