KR102471181B1 - An illumination apparatus - Google Patents

Abstract

Embodiments include a board and a light emitting unit including at least one light emitting device disposed on an upper surface of the board; A first opening located around the light emitting unit, a second opening located above the first opening and through which light irradiated from the light emitting unit is emitted, and a half located between the first opening and the second opening. a reflector including slopes; and a lens disposed on the light emitting unit inside the reflective surface and having an incident surface and an emitting surface, wherein the reflective surface has an elliptical shape, and an edge where the incident surface and the emitting surface of the lens meet is a reference straight line. Aligned to contact, the reference straight line is an imaginary straight line connecting the center of the at least one light emitting element and the top of the reflective surface, the angle between the vertical reference line and the reference straight line is 30 ° ~ 51 °, the vertical The reference line is an imaginary straight line that passes through the center of the reflector and the center of the lens and is perpendicular to the upper surface of the board.

Description

Lighting device {AN ILLUMINATION APPARATUS}

Embodiments Embodiments relate to a lighting device including a light emitting device.

In general, a light emitting diode (LED) is a device that emits light when electrons and holes meet at a P-N junction when current is applied. It has many advantages over existing light sources, such as continuous light emission and low power consumption.

In particular, LEDs are widely used in various display devices, backlight light sources, etc., and recently, a technology for emitting white light by using three light emitting diode chips each emitting red, green, and blue light or by converting the wavelength using a phosphor is used. It has been developed and is expanding its application range to lighting devices.

When using an LED with relatively low light intensity compared to a lamp with high light intensity as a light source and concentrating the power of the light source on an optical fiber or detector having a size similar to that of the light source, a simple reflector ) form, it is difficult to concentrate the power of the light source on the entire detector area.

The embodiment provides a lighting device capable of concentrating light on a target having a diameter similar to that of a light emitting surface of a light emitting device.

A lighting device according to an embodiment includes a light emitting unit including a board and at least one light emitting element disposed on an upper surface of the board; A first opening located around the light emitting unit, a second opening located above the first opening and through which light irradiated from the light emitting unit is emitted, and a half located between the first opening and the second opening. a reflector including slopes; and a lens disposed on the light emitting unit inside the reflective surface and having an incident surface and an emitting surface, wherein the reflective surface has an elliptical shape, and an edge where the incident surface and the emitting surface of the lens meet is a reference straight line. Aligned to contact, the reference straight line is a virtual straight line connecting the center of the at least one light emitting element and the uppermost end of the reflective surface, the angle between the vertical reference line and the reference straight line is 30 ° ~ 51 °, the vertical The reference line is an imaginary straight line that passes through the center of the reflector and the center of the lens and is perpendicular to the upper surface of the board.

The diameter of the first opening of the reflection part may be 1.2 times or more than the diameter of the light emitting surface of the light emitting device and 5.0 times or less than the diameter of the light emitting surface of the light emitting device.

The height of the lens may be half of the height of the reflector.

At least 40% or more of the total collected power may be condensed on a target spaced apart from the lower surface of the reflector and located in front of the second opening.

The diameter of the target may be 1.2 times or more than the diameter of the light emitting surface of the light emitting device and 1.5 times or less than the diameter of the light emitting surface of the light emitting device.

A distance from the lower surface of the reflective portion to the target may be 1.0 times or more of the diameter of the light emitting surface of the light emitting element and 4.5 times or less of the diameter of the light emitting surface of the light emitting element.

An angle between the vertical reference line and the reference straight line may be 34° to 51°.

An angle between the vertical reference line and the reference straight line may be 42° to 50°.

The diameter of the lens is defined by Equations 1 and 2,

[Equation 1]

,

,

[Equation 2]

,

,

LD2 is the diameter of the lens, B is 1/2 of the diameter of the second aperture, 0.8≤k≤1, LH2 is the height of the lens, θ may be an angle between a vertical reference line and the reference straight line .

Light passing through the exit surface of the lens may be emitted parallel to a direction perpendicular to the upper surface of the board.

The embodiment may focus light on a target having a diameter similar to that of the light emitting surface of the light emitting device.

1 shows an exploded perspective view of a lighting device according to an embodiment.
FIG. 2 shows a cross-sectional view of the lighting device shown in FIG. 1 in an AB direction.
FIG. 3 shows a cross-sectional view of the lighting device shown in FIG. 1 in a CD direction.
FIG. 4 shows light reflected by the reflective surface of the reflector shown in FIG. 1 .
5 shows the size of the reflective surface, the size and position of the lens, and the size and position of the target.
FIG. 6 shows the conditions of each case for the simulation results of FIG. 7 .
FIG. 7 shows a simulation result of light condensing of the lighting device according to FIG. 6 .
FIG. 8 shows the conditions of each case for the simulation results of FIG. 9 .
FIG. 9 shows simulation results of light condensing of the lighting device according to the condition of FIG. 8 .
10 is a graph of simulation results of FIGS. 7 and 9 .

Hereinafter, embodiments will be clearly revealed through the accompanying drawings and description of the embodiments. In the description of the embodiment, each layer (film), region, pattern or structure is “on” or “under” the substrate, each layer (film), region, pad or pattern. In the case where it is described as being formed in, "up / on" and "under / under" include both "directly" or "indirectly" formed through another layer. do. In addition, the criterion for the upper/upper or lower/lower of each layer will be described based on the drawings.

In the drawings, sizes are exaggerated, omitted, or schematically illustrated for convenience and clarity of explanation. Also, the size of each component does not fully reflect the actual size. Also, like reference numerals denote like elements throughout the description of the drawings.

1 shows an exploded perspective view of a lighting device 100 according to an embodiment, FIG. 2 shows a cross-sectional view of the lighting device 100 shown in FIG. 1 in an AB direction, and FIG. 3 is a lighting device shown in FIG. 1 ( 100) shows a cross-sectional view in the CD direction.

1 to 3 , the lighting device 100 includes a housing 110, a light emitting unit 120, a reflector 130, and a lens 140.

The housing 110 includes a cavity 111 accommodating the light emitting part 120 , the reflecting part 130 , and the lens 140 .

The housing 110 may be made of a lightweight, heat-resistant plastic material or a metal material having good thermal conductivity, for example, aluminum. A reflective material capable of reflecting light emitted from the light emitting unit 120 may be coated on an inner wall of the housing 110 . Alternatively, in another embodiment, the housing 110 itself may be made of a reflective material that reflects light.

The light emitting unit 120 is disposed within the housing 110 and emits light.

The light emitting unit 120 may include a board 122 and a light emitting element 124 . In addition, the light emitting unit 120 may further include a resin layer 126 that protects the light emitting element 124 and refracts light emitted from the light emitting element 124. Here, the resin layer 126 is can serve as a lens that refracts the

The board 122 of the light emitting unit 120 is in the form of a plate capable of mounting a light emitting element 124, supplying power to the light emitting element 124, controlling or protecting the light emitting element. may be a rescue.

For example, the board 122 may be a printed circuit board or a metal PCB. In FIG. 3 , the board 122 may have a regular hexahedral plate shape, but is not limited thereto, and may have a circular, elliptical, or polyhedral plate shape.

The light emitting element 124 is disposed on one surface (eg, upper surface) of the board 122 . The light emitting element 124 may be a light emitting diode (LED)-based light source, but is not limited thereto. For example, the light emitting device 124 may be in the form of a light emitting diode chip or a light emitting diode package.

The number of light emitting elements 124 may be one or more. In FIG. 1, one light emitting device is disposed on the board, but is not limited thereto. For example, in another embodiment, a plurality of light emitting devices may be arranged on the board 122 in a row or in various shapes such as a circular shape or a matrix shape.

The light emitting element 124 may emit light having a wavelength range of visible light or infrared light.

For example, the light emitting device 124 may emit light having a blue, red, or green wavelength range. Alternatively, the light emitting element 124 may emit light having a white wavelength range.

Alternatively, for example, the light emitting device 124 may generate ultraviolet rays having a wavelength range of 200 nm to 400 nm. Alternatively, for example, each of the light emitting elements 124-1 to 124-n, where n is a natural number > 1, may generate ultraviolet-C (UVC) light having a wavelength range of 200 nm to 280 nm.

When the number of light emitting elements is plural, the plurality of light emitting elements may generate light having the same or similar wavelength range. Also, at least one of the plurality of light emitting elements may emit light having a different wavelength range.

The reflector 130 may include a reflective surface 132 that is arranged to surround the light emitting element 124 and reflects light emitted from the light emitter 120 .

For example, the reflecting unit 130 is adjacent to the light emitting unit 120 and is located at the first opening 130a located at the lower end, located above the first opening 130a, and emits light from the light emitting unit 120. It may include a second opening 130b and a reflective surface 132 positioned between the first opening 130a and the second opening 130b. The diameter of the second opening 130b is the first opening 130a. ) is greater than the diameter of

The shapes of the first opening 130a and the second opening 130b shown in FIG. 1 are circular, but are not limited thereto, and may be elliptical or polygonal in other embodiments.

A vertical section of the reflective surface 132 may have an ellipse shape or an ellipse of curvature. For example, a vertical section of the reflective surface 132 may be a plane passing through the center of the first opening 130a and the center of the second opening 130b.

For example, in FIG. 2 , the reflective surface 132 and the extended line at the lower end of the reflective surface 132 may have the shape of an ellipse EL, and the extended line at the lower end of the reflective surface 132 may form a vertex of the ellipse EL. can

The light emitting element 124 may be aligned to be positioned at a focal point of the ellipse EL.

The light emitting part 120 is positioned apart from the reflective surface 132 , and the center of the light emitting part 120 may be aligned with the vertical reference line 101 . In this case, the center of the light emitting unit 120 may be the center of the light emitting element 124, and the center of the light emitting element 124 may be the center of the light emitting surface of the light emitting element 124.

The vertical reference line 101 may be an imaginary straight line that passes through the center of the reflector 130 and the center of the lens 140 and is perpendicular to the upper surface of the board 122 . For example, the vertical reference line 101 passes through the center of the first opening 130a, the center of the second opening 130b, and the center of the lens 140 of the reflector 130, and is on the upper surface of the board 122. It may be a vertical imaginary straight line.

The reflector 130 includes a reflective surface 132 having an elliptical cross section, a side surface 134 positioned opposite to the reflective surface 132, and a lower surface positioned between the reflective surface 132 and the side surface 134 ( 136) may be included.

The reflector 130 may be made of a reflective metal, for example, stainless steel or silver (Ag). Alternatively, the reflector 130 may be a metal material having a specular reflection.

Alternatively, the reflector 130 may be made of a resin material having high reflectivity, but is not limited thereto.

The lens 140 is disposed in a space inside the reflective surface 132 on the light emitting unit 120, and refracts and transmits light emitted from the light emitting unit 120. For example, the center of the lens 140 may be aligned with the center of the light emitting unit 120, the center of the first opening 130a, and the center of the second opening 130b.

The lens 140 includes a convex refractive portion 142 in a direction from the bottom to the top of the reflecting portion 130 or in a direction from the light emitting portion 120 toward the lens 140, and a support portion 144 provided on the lower surface of the refractive portion 142. ) may be included.

The support portion 144 of the lens 140 is coupled to the coupling groove 122a provided on the upper surface of the board 122 and may support the lens 140 . The number of support parts 144 may be two or more.

In FIG. 1 , four support parts 144 provided on the bent part 142 are shown, but are not limited thereto.

For example, in order to suppress the refraction of light emitted from the light emitting unit 120 by the support units 144 , the support units may be spaced apart from each other and connected to the lower surface of the refracting unit 142 .

1, the support 144 of the lens 140 is coupled to the groove 122a provided on the board 122, but is not limited thereto, and in another embodiment, the support 144 of the lens 140 is a housing ( 110) may be coupled to a groove provided on the lower surface of the cavity 111.

In another embodiment, the groove 122a is not provided in the board 122, and the support 144 may be fixed to the lower surface of the board 122 or the cavity 111 of the housing 110 by an adhesive member. .

3 shows light refracted by the lens 140 .

The refraction part 142 of the lens 140 may include an incident surface 142a and an exit surface 142b.

The incident surface 142a of the refracting part 142 of the lens 140 may be a surface on which light irradiated from the light emitting element 124 is incident and refracted, and may be spaced apart from the reflective surface 132 .

The exit surface 142b of the refracting part 142 of the lens 140 refracts and passes the light passing through the incident surface 142a. The light passing through the incident surface 142a and the exit surface 142b of the refracting part 142 of the lens 140 is converted into light 148 parallel to the direction from the light emitting part 120 toward the lens 140. can

For example, the incident surface 142a of the lens 140 may be a plane parallel to the upper surface of the board 122, and the exit surface 142b is a convex hemisphere in a direction from the light emitting unit 120 toward the lens 140. It may have a shape, a parabolic shape, or an elliptical shape, but is not limited thereto, and in another embodiment, light passing through the incident surface 142a and the exit surface 142b is incident so that it can be converted into parallel light 148. The surface 142a and the exit surface 142b may be implemented in various forms.

The inner space of the reflective surface 132 and the space between the lens 140 and the light emitting unit 120 may be filled with gas, for example, air, but are not limited thereto, and may be filled with a translucent material in another embodiment.

The edge 142-1 of the lens 140 may be spaced apart from an imaginary reference straight line 102a connecting the center of the light emitting element 124 and the uppermost end 132-1 of the reflective surface 132a. Alternatively, the edge 142-1 of the lens 140 may be aligned with or in contact with the imaginary reference straight line 102a.

If the edge 142-1 of the lens 140 overlaps the imaginary reference straight line 102a, the light reflected by the reflective surface 132 and the light refracted by the lens 140 interfere with each other. However, due to the interference of the light, the desired light cannot be focused on the target.

For example, the edge 142-1 of the lens 140 may be a corner of the lens 140 where the incident surface 142a and the exit surface 142b of the lens 140 come into contact.

When the number of light emitting elements 124 is plural, the center of the light emitting element 124 may be the center of a region in which the light emitting elements are distributed.

Light from the light emitting element 124 irradiated to the first region of the reflector 130 is refracted by the lens 140, and the refracted light is light parallel to the direction from the light emitting part 120 toward the lens 140. It can be converted to (148) and emitted. The first area of the reflector 130 may be an area located on one side of an imaginary reference straight line 102a connecting the center of the light emitting element 124 and the uppermost end 132-1 of the reflective surface 132a. For example, the first region of the reflector 130 is a closed curved surface (eg, a cone) formed of imaginary reference straight lines 102a connecting the center of the light emitting element 124 and the uppermost end 132-1 of the reflective surface 132a. ).

For example, the light of the light emitting element 124 irradiated above the reference straight line 102a is refracted by the lens 140, and the refracted light is parallel to the direction from the light emitting unit 120 to the lens 140 ( 148) and can be emitted.

4 shows the light 149 reflected by the reflective surface 132 of the reflective unit 130 shown in FIG. 1, and FIG. 5 shows the size of the reflective surface 132, the size and position of the lens 140, and the size and position of the target.

Referring to FIGS. 4 and 5 , light from the light emitting element 124 emitted below the reference line 102a is directly reflected by the reflective surface 132 . Since the reflective surface 132 has an elliptical shape, the light 149 reflected by the reflective surface 132 may be focused on the target Ta located at a certain distance.

For example, the light of the light emitting element 124 emitted below the reference line 102a is converted into light 149 condensed to pass through or contact the vertical reference line 101 by reflection of the reflective surface 132 and be emitted. can

Referring to FIGS. 3 and 4 , the diameter ED1 of the first opening 130a of the reflector 130 may be 1.2×LD to 5.0×LD. For example, LD may be the diameter of the light emitting surface of the light emitting element 124, and ED1 may be the diameter of the lowest end of the reflective surface 132.

When the diameter ED1 of the first opening 130a is greater than or equal to 1.2×LD, light generated from the light emitting element 124 can be directed to the reflective surface 132 without loss. Accordingly, when the diameter ED1 of the first opening 130a is less than 1.2×LD, the amount of light emitted from the light emitting element 124 may be lost.

Also, when the diameter ED1 of the first opening 130a exceeds 5.0×LD, the diameter of the first opening 130a is too far apart from the area of the light source, so the loss of light quantity increases and the optical power decreases.

In order to condense light on a target Ta having a diameter similar to the diameter LD of the light emitting surface of the light emitting element 124, the diameter TD of the target Ta according to the embodiment is 1.2×LD to 1.5× may be LD.

In addition, the distance TH from the lower surface 136 of the reflector 130 to the target Ta may be 1.0×LD to 4.5×LD.

This is because when TH is greater than 4.5×LD, the condensed optical power decreases to less than 40% because the condensed distance increases.

When TH is less than 1.0 × LD, the distance TH from the lower surface 136 of the reflector 130 to the target Ta is too close to obtain a light condensing effect by the reflector 130 and the lens 140 There is not.

An angle θ between the vertical reference line 101 and the reference straight line 102a is defined by Equation 1.

ED2 may be the diameter of the second opening 130b. For example, ED2 may be the diameter of the top of the reflective surface 132 .

EH represents the height of the reflector 130 . For example, EH may be a distance from the lower surface 136 of the reflecting part 130 to the uppermost end 132-1 of the reflecting surface 132.

An angle θ between the vertical reference line 101 and the reference straight line 102a may be 30° to 51°.

When θ is less than 30°, the focal length a of the elliptical shape EL becomes farther away and the amount of light decreases. When θ exceeds 51°, the focal length a of the elliptical shape EL becomes shorter and it is difficult to collect light. .

The diameter LD2 of the lens 140 is defined by Equations 2 and 3.

k represents a constant related to the interference of lights, and may be 0.8≤k≤1.

When k=1, the edge 142-1 of the lens 140 may be aligned with the imaginary reference straight line 102a.

When k>1, light interference may occur because the edge 142-1 of the lens 140 overlaps the virtual reference straight line 102a.

When k<0.8, the diameter of the lens 140 becomes small, so that the light condensing effect by the lens 140 cannot be obtained.

LH2 represents the height of the lens 140.

For example, LH2 may be a distance from the lower surface 136 of the reflector 130 to the incident surface 142a of the lens 140 .

Considering the fact that the lens 140 has an elliptical curvature and the distance to the target Ta, the height LH2 of the lens 140 is set to 1/2 of the height EH of the reflector 130. do. The curvature of the lens 140 may vary according to the distance TH to the target. That is, as the light condensing area of the lens 140 decreases, the height of the curvature of the lens 140 increases and the distance TH to the target Ta may also increase. Considering the distance to the target that the lens 140 having an elliptical curvature can condense, the embodiment sets LH2 to 1/2 of EH, thereby reducing the amount of light emitted from the light emitting element 124 by 25%. ~ 60% can be condensed to a desired target (Ta).

In Equation 3, B is 1/2 of the uppermost diameter of the reflective surface 132 when LH2 is 1/2 of the height EH of the reflector 130, or the diameter of the second opening 130b (ED2 ) may be 1/2 of

Light from the light emitting device 124 radiated to the second area of the reflector 130 by the reflector 130 may be focused on the target area.

Even considering the light lost by the lens 140, the embodiment is from the lighting device. At least 40% or more of the total optical power of emitted light may be focused on the target area.

FIG. 6 shows conditions of each case for the simulation results of FIG. 7 , and FIG. 7 shows simulation results of light condensing of the lighting device according to FIG. 6 . LES represents the diameter of the light emitting surface of the light emitting element 124, LES is 3.5 mm, and the size of a target, for example, a detector, may be 5 mm × 5 mm. Here, the detector may measure the power or amount of light received. F1 and F2 represent the focus of the ellipse, R is the vertex radius of the ellipse, k is a conic constant, and F is the distance from the origin of the ellipse to the focus (or the light emitting element 124). It is a distance.

Total collected power represents the collected power of all light emitted from the lighting device, and detector collected power represents the power of light detected by a target (Ta), for example, a detector, and rate is It represents the ratio of total cumulative power and detector cumulative power.

The size of the target Ta, for example, the detector, may be 1.2 to 1.5 times the diameter of the light emitting surface.

Referring to FIGS. 6 and 7 , the case where the rate is 40% or more may be case 1 to case 4, and θ may be 30° to 51°.

FIG. 8 shows conditions of each case for the simulation results of FIG. 9 , and FIG. 9 shows simulation results of light condensing of the lighting device according to the conditions of FIG. 8 .

The LES may be 14.5 mm, and the size of the target, eg, detector, may be 18 mm × 18 mm.

Referring to FIGS. 8 and 9 , cases in which the rate is 40% or more may be case 1 to case 4, and θ may be 30° to 51°.

10 is a graph of simulation results of FIGS. 7 and 9 .

f1 is a graph according to the simulation result of FIG. 7 , and f2 is a graph according to the simulation result of FIG. 9 .

Referring to FIG. 10 , θ at a rate of 40% may be 28°. Considering the error margin of 2°, θ of the lighting device 100 according to the embodiment may be 30° or more and 51° or less so that the rate is 40% or more. When θ exceeds 51°, the height (EH) of the reflective surface 132 becomes too small, and it is difficult for the reflective surface 132 to have an elliptical shape, so that light cannot be focused on a desired target. Set to 51°.

When θ is 30 ° to 51 °, the rate may be 40% or more and 68% or less.

In addition, θ may be 34 ° to 51 ° so that the rate is 50% or more.

In addition, θ may be 42 ° to 50 ° so that the rate is 60% or more.

When using an LED with relatively low light intensity compared to a lamp with high light intensity as a light source and concentrating the power of the light source on an optical fiber or detector having a size similar to that of the light source, a simple reflector ) form, it is difficult to concentrate the power of the light source on the entire detector area.

The embodiment has the following effects.

First, the amount of light lost to the optical system group can be reduced by using a condensing lens as a central lens of a reflector having an ellipsoidal reflective surface for condensing light.

Second, while the system efficiency is usually about 70% in an optical system using multiple lenses for light condensation, the embodiment uses two optical elements, for example, two lenses, so the lens group efficiency is It may be at least 84%, and alignment of the optical axis may be easy.

Third, the size and position of the lens can be easily adjusted according to the rules according to the area and distribution of the light emitting element 124 .

In the embodiment, 40% or more of the total cumulative power of the amount of light emitted from the reflector 130 of the lighting device may be condensed to the target.

Features, structures, effects, etc. described in the embodiments above are included in at least one embodiment of the present invention, and are not necessarily limited to only one embodiment. Furthermore, the features, structures, effects, etc. illustrated in each embodiment can be combined or modified with respect to other embodiments by a person having ordinary knowledge in the field to which the embodiments belong. Therefore, contents related to these combinations and variations should be construed as being included in the scope of the present invention.

110: housing 120: light emitting part
122: board 124: light emitting element
126: resin layer 130: reflector
132 reflective surface 140 lens.

Claims (10)

a light emitting unit including a board and at least one light emitting element disposed on an upper surface of the board;
A first opening located around the light emitting unit, a second opening located above the first opening and through which light irradiated from the light emitting unit is emitted, and a half located between the first opening and the second opening. a reflector including slopes; and
A lens disposed on the light emitting unit inside the reflective surface and having an incident surface and an exit surface,
The reflective surface has an elliptical shape, and an edge where the incident surface and the emitting surface of the lens meet is aligned to contact a reference straight line, and the reference straight line connects the center of the at least one light emitting element and the uppermost end of the reflective surface. is an imaginary straight line,
The angle between the vertical reference line and the reference line is 30 ° to 51 °, and the vertical reference line is an imaginary straight line passing through the center of the reflector and the center of the lens and perpendicular to the upper surface of the board,
The light reflected by the reflective surface is condensed on a point of a target located in front of the second opening and spaced apart from the lower surface of the reflective part, and the light refracted by the lens is separated from the vertical reference line. Proceeding in parallel, at least 40% or more of the total collected power is condensed on the target,
A diameter of the target is larger than a diameter of a light emitting surface of the light emitting element and smaller than a diameter of the second opening. According to claim 1,
The lighting device of claim 1 , wherein a diameter of the first opening of the reflecting portion is 1.2 times or more of a diameter of the light emitting surface of the light emitting element and 5.0 times or less of a diameter of the light emitting surface of the light emitting element. According to claim 1,
The diameter of the lens is defined by Equations 1 and 2,
[Equation 1]

,
[Equation 2]

,
LD2 is the diameter of the lens, B is 1/2 of the diameter of the second aperture, 0.8≤k≤1, LH2 is the height of the lens, θ is the angle between the vertical reference line and the reference straight line Illumination Device. According to any one of claims 1 to 3,
The lighting device of claim 1, wherein the height of the lens is half of the height of the reflector. According to claim 4,
The diameter of the target is 1.2 times or more of the diameter of the light emitting surface of the light emitting element and 1.5 times or less of the diameter of the light emitting surface of the light emitting element;
A distance from the lower surface of the reflector to the target is 1.0 times or more of a diameter of a light emitting surface of the light emitting element and 4.5 times or less of a diameter of a light emitting surface of the light emitting element. delete delete delete delete delete

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