TWI484121B - A light-emitting device, a down-illuminated lamp, and a light guide plate for a down-illuminated lamp - Google Patents

Description

Illuminating device, downlighting lamp and light guide plate for downlighting lamp

The present invention relates to a light-emitting device, and more particularly to a light-emitting device using a light-emitting diode (LED) as a light source, and a down-lighting lamp and a light guide plate for a down-lighting lamp using the structure of the light-emitting device.

Referring to Figures 1 and 2, a lighting device 1 disclosed in the Taiwan Patent No. I329182 includes a substantially bowl-shaped lampshade 11, a receiving seat 12 locked in the lampshade 11, and a surrounding a light guide plate 13 between the lamp cover 11 and the socket 12, a reflective layer 14 attached to the inner surface of the lamp cover 11, and a plurality of light emitting diodes 15 mounted on the socket 12 and facing the light guide plate 13 . The light emitted by the light-emitting diode 15 is guided by the light guide plate 13 and is reflected by the light-guiding plate 13 and then reflected downward by the reflective layer 14 . The reflected light can also be reflected in the light guide plate 13 . The light is mixed, and finally the light is directed downward through the light guide plate 13 to illuminate downward.

Although the illumination device 1 of the prior art can reflect the light downward, the reflection angle of the reflected light is relatively large due to the poor controllability of the light guide plate 13 and the reflective layer 14 to the light exit angle. The light emitted from the lower surface is diffused outwardly and cannot be concentrated in the range of angles required for general lighting fixtures.

Accordingly, it is an object of the present invention to provide a light-emitting device, a down-lighting lamp, and a light guide plate for a down-illuminated lamp which have a good reflection effect and can control the light-emitting angle.

Therefore, the light-emitting device of the present invention comprises: a light source unit, a light guide plate, and a reflection sheet. The light source unit includes at least one light emitting diode. The light guide plate is disposed at one side of the light source unit and configured to conduct light of the light source unit, the light guide plate includes a light guiding body having a first surface and a second surface, and a plurality of first The light guiding microstructure of the surface is prominent. The reflective sheet is located at one side of the light guide plate and opposite to the first surface of the light guide plate. The reflective sheet reflects the light passing through the light guide plate again toward the light guide plate to emit light outward. The reflective sheet The invention comprises a plurality of reflective microstructures protruding toward the light guide plate, each reflective microstructure having an apex angle of δ and 90° ≦ δ ≦ 170°.

The apex angle of the reflective microstructure of the present invention is δ, and 90° ≦ δ ≦ 170°. This limitation enables the reflective microstructure to have a special shape, which can effectively control the light angle, so that the light incident on the surface of the reflective microstructure can be Reflecting in the direction of the light guide plate at a more concentrated angle, the downwardly irradiated light is concentrated in a range of ±35°. Wherein, when δ is less than 90°, the incident light is easily reflected in a direction away from the light guide plate, and the light cannot be effectively reflected and taken out; when δ is greater than 170°, that is, close to a planar shape of 180°, resulting in a reflective microstructure. The shape of the structure is not obvious, and it is not effective to achieve the purpose of controlling the angle of light.

The reflective sheet further includes a substrate having a plurality of protrusions, and a reflective film covering the bottom surface of the substrate, the reflective microstructure being formed by the protruding portion of the substrate and the reflective film. The material of the substrate is a polymer material, preferably a plastic film that can reflect light or a material composed of a sheet, or a plastic film that can reflect light or a material composed of a laminate of a sheet and a metal sheet. . Specific examples thereof are: polyethylene, polystyrene, polychlorinated ethylene, polychlorinated biphenyl, polyvinyl alcohol, polycarbonate, polybutylene terephthalate (PBT), Polyethylene terephthalate (PET), polyurethane (polyurethane), polyamide, polyacetal, polydimethylene ether, polyacrylate, polyamidide (polyamide) -imide), polyetherimide, polyetheretherketone, polyimide, polytetrafluoroethene (PTFE), and the like. The reflective film can be formed on the surface of the substrate by vapor deposition. The material of the reflective film is a metal having good light reflectivity, such as aluminum, tantalum, niobium, silver, titanium, chromium, molybdenum and the like, and alloys thereof. Composition.

The reflective microstructure can be produced by roll extrusion, injection molding, coating forming, transfer, and the like.

The light guiding microstructure of the light guiding plate of the present invention may be a square column, a trapezoidal column, a circular column or a triangular column extending in a long direction, but the shape thereof is not limited to a column shape, and the light guiding microstructure may also be arranged in a plurality of front, back, left and right directions. Arranged on the light guiding body, and has a shape of a pyramid, a sphere, a square, a triangle, or the like.

Each light guiding microstructure has a structural periphery extending from the first surface toward the reflective sheet and surrounding, and a structural end surface connected to an edge of the structural surrounding surface adjacent to the reflective sheet; The angle between the structural envelope of a light guiding microstructure and the first surface is a structural angle θ, the structural angle θ is located outside the light guiding microstructure, and 90° ≦ θ ≦ 90 ° + θ _n , θ _n is a critical angle at which light can be totally reflected when the light is incident on the light guide plate; the width of the end face of the structure is w, the height of the light guide microstructure is h, and 0≦w≦h×tanθ _n . Moreover, for different light guide plate materials, there are different critical angles θ _n , but as long as the critical angle θ _{n of the} light guide plate material can be known, the relationship can be made according to the above relationship 0≦w≦h×tanθ _n . Light guiding microstructures with appropriate h and w. For a microstructure of a square column, a trapezoidal column or a tetragonal body, both the structural envelope surface and the structural end surface are flat surfaces; when the light guiding microstructure has a tip-shaped shape, such as a triangular column shape or a triangular pyramid shape, It has w=0, that is, it does not have the end face of the structure.

The light guiding body and the light guiding microstructure may be prepared by roller extrusion, injection molding, biting, printing, non-printing, etc.; and the light guiding microstructure may be arranged regularly or irregularly.

The resin used in the light guide plate of the present invention comprises: (meth) acrylate resin, polystyrene resin, polycarbonate resin, methyl methacrylate-styrene copolymer, acrylonitrile-styrene copolymer And a group consisting of polyethylene terephthalate. The above-mentioned (meth) acrylate-based resin is a polymer formed of a (meth) acrylate-based monomer, for example, polymethyl methacerylate (PMMA), and the above (meth)acrylic acid. Specific examples of the ester-based monomer include: methyl methacrylate, ethyl methacrylate, isopropyl methacrylate, n-butyl acrylate, methyl acrylate, ethyl acrylate, isopropyl acrylate, and the like, wherein Methyl methacrylate and methyl acrylate are preferred.

The light guide plate of the invention can add a light diffusing agent to the resin, and the light diffusing agent used can make the light guide plate have a better light diffusion atomization function, and the light is evenly softened. Specific examples of the light diffusing agent: inorganic fine particles and organic fine particles; inorganic fine particles such as fine particles such as barium sulfate (BaSO ₄ ) and titanium oxide (TiO ₂ ); and organic fine particles such as polystyrene resin or (meth)acrylic resin Rack bridge microparticles formed by an organic siloxane resin or the like. Two or more types of diffusing agents can be used in combination. The average particle diameter of the above diffusing agent is preferably in the range of 0.1 to 20 μm. The content of the diffusing agent is preferably 0.01 to 1000 ppm by weight in the light guiding resin.

The illuminating device of the present invention can be a downlight luminaire, and of course, can be applied to other forms of luminaires or illuminable devices. When the illuminating device is a downlight illuminator, the light guide plate is located below the reflective sheet, the first surface and the second surface of the light guide plate are vertically opposed, and the first surface faces the reflective sheet, and the second surface Downward, the light directing microstructure protrudes upward from the first side. The reflective microstructure of the reflective sheet protrudes downward, and the reflective sheet reflects the light passing through the light guide plate again toward the light guide plate to cause the light to be emitted downward.

The present invention also provides a light guide plate for a downlight type luminaire, which comprises the above structure.

The effect of the invention is that the reflective sheet is provided with a reflective microstructure, has a good light reflection effect, and is matched with the appropriate apex angle design of the reflective microstructure, so that the reflected light can be uniformly guided to the desired light exit angle. In addition, the light guiding microstructure design on the light guide plate can achieve the effect of light guiding and full light mixing, and also has the function of controlling the light angle.

The above and other technical contents, features and advantages of the present invention will be apparent from the following detailed description of the preferred embodiments of the invention. Before the present invention is described in detail, it is noted that in the following description, similar elements are denoted by the same reference numerals.

Referring to Figures 3, 4 and 5, a first preferred embodiment of the illuminating device of the present invention is a down-illuminated luminaire which can be mounted on a ceiling of a building and illuminates the light downward, but is not limited thereto. The light emitting device comprises: a light source unit 2, a light guide plate 3, and a reflective sheet 4.

The light source unit 2 includes at least one light-emitting diode 21, and in this embodiment, a plurality of light-emitting diodes 21 are disposed, and are divided into two groups and disposed on the left and right sides of the light guide plate 3, and the light-emitting diodes on the same side. 21 is arranged in front and rear. The present invention does not need to limit the arrangement position and arrangement of the light-emitting diodes 21, and may be disposed, for example, on the left side or the right side of the light guide plate 3.

The light guide plate 3 is configured to conduct light emitted from each of the light-emitting diodes 21 to conduct light to the upper side of the light guide plate 3. The material of the light guide plate 3 is not particularly limited as long as it has a good light guiding effect. The light guide plate 3 includes a flat light guiding body 31 and a plurality of light guiding microstructures 32 protruding from the light guiding body 31. The light guiding body 31 has an upwardly facing first surface 311 and a second surface 312 opposite to the first surface 311. The material of the light guiding body 31 and the light guiding microstructure 32 is polymethyl methacrylate. Polymethyl methacerylate (PMMA), the shape of the light guiding body 31 and the light guiding microstructure 32 can be obtained by pushing out the roller.

Each of the light guiding microstructures 32 protrudes from the first surface 311 toward the reflective sheet 4. The light guiding microstructures 32 of the present embodiment are square pillars extending in the front-rear direction and each of the light guiding microstructures. 32 has a structural surrounding surface 321 extending from the first surface 311 toward the reflective sheet 4 and surrounding the front, rear, left and right sides, and a structural end surface connected to an edge of the structural surrounding surface 321 adjacent to the reflective sheet 4 322. Specifically, the light guiding microstructure 32 protrudes upward from the first surface 311, the structural surrounding surface 321 extends upward from the first surface 311, and the structural end surface 322 is connected to the structural surrounding surface 321 The top edge. The light guiding microstructures 32 of the present embodiment are spaced apart, and have a flat surface 320 between adjacent light guiding microstructures 32. The flat surface 320 is actually a partial surface of the first surface 311.

Defining the angle between the structural envelope 321 of each light guiding microstructure 32 and the first surface 311 is a structural angle θ, which is an angle between the outside of the light guiding microstructure 32 and not the inside angle, and 90 ° ≦ θ ≦ 90 ° + θ _n , the θ _n is a critical angle at which the light can be totally reflected when the light guide plate 3 is incident on the air. Further, the width of the end surface 322 of the structure is w, the height of the light guiding microstructure 32 is h, and 0 ≦ w ≦ h × tan θ _n .

Here, the definition of θ will be described: generally, when the light guiding microstructure 32 is molded, it is mainly formed by a mold, but there is a limitation of the releasing angle at the time of demolding, and therefore the structural angle θ is always greater than or equal to 90°. In addition, it is generally desired that the light of the light source unit 2 can be reflected and reflected by the light guide plate 3 multiple times, and then emitted from above the light guide plate 3, especially by the light guide of the light guide microstructure 32, so that the light can be transmitted. Fully guided by light and homogenization.

Referring to FIG. 6, when light rays are directed upward from the light guide plate 3 toward the first surface 311, since the incident angles of the light rays A and B in the figure are larger than the critical angle θ _n , the light rays A and B are incident on the first surface. 311 (that is, the interface between the light guide plate 3 and the air) will continue to propagate in the light guide plate 3 due to total reflection, and therefore, the angle of many rays propagating in the light guide plate 3 is greater than the critical angle θ _n . Therefore, when the light rays C and D having an incident angle greater than θ _n are incident on the boundary between the light guiding microstructure 32 and the first surface 311, in order to allow the light rays C and D to enter the light guiding microstructure 32, the light guiding micro The size of the structure 32 must at least cover the range of the right half of a critical line L, that is, the left half of the structural envelope 321 must be located at the left half of L or at least at L, and relatively, if θ is too large, the structure If the imaginary line 321' is located on the right half of the critical line L, the structure of the light guiding microstructure 32 is too short, and the light rays C and D will directly pass through the interface and cannot be exposed by the light guiding microstructure 32. Light guiding effect. Therefore, it must be defined that θ cannot exceed 90° + θ _{n at the} maximum in order to allow most of the light to be transmitted through the light guiding microstructure 32.

Referring to Figure 7, the width w of the end face 322 of the structure is further explained (since Figure 7 is for illustrative purposes only, the w value will vary with different designs, so Figure 7 does not indicate w): if the light guide The microstructure is as shown in the triangular prism or triangular pyramid shape shown in the right half of the imaginary line. At this time, the top end is the tip end, w=0; and because the above definition is 90° ≦ θ ≦ 90 ° + θ _n , the end surface 322 of the structure The minimum width w can be equal to 0, and the maximum value does not exceed w1 in the figure, that is, w≦w1, and w1=h×tanθ _n , so w≦h×tanθ _n can be obtained. Through the relationship between w, h and θ _n described above, the form of the light guiding microstructure 32 is limited, and the light is sufficiently entered into the light guiding microstructure 32, and is guided and uniformly mixed upward after being guided and mixed.

4 and 5, the reflective sheet 4 is located above the light guide plate 3, and the light passing through the light guide plate 3 is again reflected toward the light guide plate 3 to emit light outward. In this embodiment, The light is reflected downward so that the light can finally exit through the second face 312 of the light directing body 31. The reflection sheet 4 includes a substrate 41 having a plurality of protrusions 411, and a reflection film 42 coated on the bottom surface of the substrate 41. The material of the substrate 41 of the present embodiment is polyethylene terephthalate (PET), and the material of the reflective film 42 of the present embodiment is an aluminum-plated metal. After the substrate 41 and the reflective film 42 collectively comprise the reflective sheet 4, the reflective sheet 4 includes a plurality of reflective microstructures 43 formed by the protruding portion 411 of the substrate 41 and the reflective film 42 and spaced apart from each other, and A plurality of flat reflecting surfaces 44 that face the light guide plate 3 and are respectively connected between adjacent reflective microstructures 43 are the surfaces of the reflecting film 42. Each of the reflective microstructures 43 has an apex angle of δ, and 90° ≦ δ ≦ 170°, whereby the reflective microstructure 43 can effectively control the light angle, and the light reflected by the reflective microstructure 43 is concentrated. The angle is reflected downwards, thus concentrating the illumination light, and the light exit angle meets the lighting requirements of general lamps. Moreover, the structural end surface 322 of the light guiding microstructure 32 of the present embodiment is located at the top corner of the reflective sheet 4.

Referring to FIG. 8, the angular limit of the apex angle δ is then illustrated by an actual legend. When the incident ray E is incident on the reflective microstructure 43 having a apex angle δ greater than 90°, it can be reflected downward (eg, ray F), but the same incident ray. E is incident on the reflective microstructure 43' whose apex angle is less than 90° as shown by the imaginary line in Fig. 8. The light is reflected upward (such as light G), that is, when the apex angle is too small, the light cannot be effectively It is reflected downward and taken out; therefore, the invention is preferably limited to 90° ≦δ. Of course, due to the large angle of incident light, for some angles of light, it will still be reflected upward by the reflective microstructure 43 but due to the reflection of the present invention. The sheet 4 is provided with a flat reflecting surface 44 which can also be used to reflect light downwards. On the other hand, when δ is larger than 170°, that is, nearly 180° in a planar shape, the protruding structure of the reflective microstructure 43 is not conspicuous, and naturally, the light angle cannot be effectively controlled, so that it is preferable to define δ ≦ 170°.

Referring to FIGS. 6, 7, and 8, further exemplified, the structural angle θ of the embodiment is θ=93°, and the material of the light guiding body 31 and the light guiding microstructure 32 is θ _n =42.15° of the material polymethyl methacrylate, and the structural end surface 322 The width w = 100 μm, the height of the light guiding microstructure 32 is h = 115 μm, and the apex angle of the reflective microstructure 43 is δ = 100°. Because the structure angle θ=93°, and 90°≦93°≦90°+42.15°, the formula 90°≦θ≦90°+θ _{n is} satisfied; since w=100μm, h=115μm, 100≦115×tan42.15 °, so the formula w≦h×tan θ _n is satisfied; since the apex angle δ=100°, the formula 90°≦δ≦170° is satisfied.

Referring to FIG. 9, the angle of refraction of the light entering the air through the light guiding microstructure 32 on the light guide plate 3 is defined as 90-a, and the incident angle of the light incident on the surface of the reflective microstructure 43 is b. After reflection 43 is reflected downward (e.g., light H), a = 2b, and the apex angle δ = 180 - 2b of the reflective microstructure 43. Referring to Table 1, the relationship between a, b, and δ is shown, and the light of the reflection sheet of the present invention for different incident angles is reflected by the reflective microstructure 43 so that it can be emitted downward and downward. More concentrated, it is necessary to change the angle design of δ for the light of various incident angles. As shown in Table 1, the δ which is modulated for various incident angles is within the range of 90° to 170° defined by the present invention. .

3, 4, and 5, when the present invention is used, the light-emitting diodes 21 are arranged along the length extension direction of the light-guiding microstructures 32, and the light of the light-emitting diodes 21 enters the side of the light guide plate 3. The light guide plate 3 has a function of conducting light upwards. After the light is sufficiently guided and mixed by the light guide plate 3, the light guide structure 32 controls the light to be upwardly refracted, so that the light is emitted upward. To the reflection sheet 4, the reflection sheet 4 reflects the light downward, and the apex angle design of the reflection microstructure 43 can also achieve the purpose of controlling the light angle, so that the angle of illumination and the illumination range of the downward illumination meet the illumination requirements. It should be noted that, since the embodiment is a luminaire, it is desirable to make the light angle meet the lighting requirement. If the present invention is applied to other types of illuminating devices, such as an advertising light box, the light angle requirements may be different, but the same can be achieved. The reflection sheet 4 of the present invention is designed to achieve good control.

In summary, the reflective sheet 4 is provided with the reflective microstructure 43 and has a good light reflection effect, and the appropriate apex angle design of the reflective microstructure 43 can uniformly guide the reflected light to the desired light exit angle. The purpose of the invention.

Referring to FIGS. 10 and 11, the second preferred embodiment of the illuminating device of the present invention is substantially the same as the first preferred embodiment. The difference is that the light guiding microstructure 32 of the light guide plate 3 of the present embodiment is spherical. And spaced apart from each other Arranged left and right.

The above is only the preferred embodiment of the present invention, and the scope of the invention is not limited thereto, that is, the simple equivalent changes and modifications made by the scope of the invention and the description of the invention are All remain within the scope of the invention patent.

2‧‧‧Light source unit

21‧‧‧Lighting diode

3‧‧‧Light guide plate

31‧‧‧Lighting body

311‧‧‧ first side

312‧‧‧ second side

32‧‧‧Light guiding microstructure

321, 321'‧‧‧ structural enclosure

322‧‧‧ structural end face

320‧‧‧flat surface

4‧‧‧reflector

41‧‧‧Substrate

411‧‧‧ protruding parts

42‧‧‧Reflective film

43, 43'‧‧‧reflective microstructure

44‧‧‧reflecting surface

A, B, C, D, E, F, G, H‧‧‧ rays

L‧‧‧ critical line

w, w1‧‧‧ width

H‧‧‧height

a‧‧‧Reflection angle

B‧‧‧incident angle

Θ‧‧‧ structural angle

θ _n ‧‧‧critical angle

δ‧‧‧Top angle

1 is a perspective exploded view of a known lighting device; FIG. 2 is a side cross-sectional view of the known lighting device; FIG. 3 is a perspective view of a first preferred embodiment of the light emitting device of the present invention; FIG. 5 is a partially enlarged front elevational view of the first preferred embodiment; FIG. 6 is a partially enlarged schematic view of a light guide plate of the first preferred embodiment for explaining the FIG. 7 is a partially enlarged schematic view of the light guide plate for explaining the structural design of the light guide plate; FIG. 8 is a partially enlarged schematic view of a reflective sheet of the first preferred embodiment, FIG. 9 is a partially enlarged schematic view showing the first preferred embodiment of the first preferred embodiment, showing the traveling path of the light receiving the light guide plate and the reflecting sheet; FIG. 10 is a lighting device of the present invention. A front view of a light guide plate according to a second preferred embodiment; and FIG. 11 is a top plan view of the light guide plate of the second preferred embodiment.

2. . . Light source unit

twenty one. . . Light-emitting diode

3. . . Light guide

31. . . Light guide body

311. . . First side

312. . . Second side

32. . . Light guiding microstructure

321. . . Structural enclosure

322. . . Structural end face

320. . . Flat surface

4. . . A reflective sheet

41. . . Substrate

411. . . Protruding

42. . . Reflective film

43. . . Reflective microstructure

44. . . Reflective surface

Claims (12)

A light-emitting device comprising: a light source unit comprising at least one light-emitting diode; a light guide plate disposed on one side of the light source unit and configured to conduct light of the light source unit, the light guide plate comprising an opposite one a light guiding body on one side and a second surface, and a plurality of light guiding microstructures protruding from the first surface; and a reflective sheet on one side of the light guiding plate and opposite to the first surface of the light guiding plate The light reflecting the light passing through the light guide plate is again reflected toward the light guide plate to emit light through the second surface of the light guide body, and the reflective sheet includes a plurality of reflective microstructures protruding toward the light guide plate. Each reflective microstructure has an apex angle of δ, and 90° ≦ δ ≦ 170°; wherein each light directing microstructure has a structural envelope extending from the first surface toward the reflective sheet, and An end face of the structure attached to the periphery of the structure, wherein the end face of the structure is located at a top corner of the reflective sheet. The illuminating device of claim 1, wherein the reflective microstructures are spaced apart, the reflective sheet further comprising a plurality of flats facing the light guide plate and each being connected between adjacent reflective microstructures Reflective surface. The light-emitting device of claim 1 or 2, wherein the reflective sheet further comprises a substrate having a plurality of protrusions, and a reflective film covering the surface of the substrate, the reflection micro The structure is formed by the protruding portion of the substrate and the reflective film. The light-emitting device according to claim 3, wherein the material of the substrate is a polymer material, and the material of the reflective film is metal. The illuminating device of claim 1, wherein the light guiding microstructure of the light guiding plate is spaced apart and has a flat surface between adjacent light guiding microstructures. The illuminating device according to claim 1 or 2, wherein the angle between the structural envelope of each light guiding microstructure and the first surface is defined as a structural angle θ, and the structural angle θ is located at the light guiding The outside of the microstructure, and 90 ° ≦ θ ≦ 90 ° + θ _n , the θ _n is the critical angle at which the light can be totally reflected when the light is incident on the light guide plate; the width of the end face of the structure is w, the guide The height of the light microstructure is h, and 0≦w≦h×tan θ _n . The light-emitting device of claim 6, wherein the material of the light guide plate contains a light diffusing agent. The light-emitting device of claim 6, wherein the light guiding microstructure is in the shape of a trapezoidal column, a square column or a triangular column. The light-emitting device of claim 6, wherein the light guiding microstructure is disposed on the front, rear, left, and right sides and is arranged on the light guiding body, and is in the shape of a pyramid, a quadrangle or a triangular pyramid. A downlighting lamp comprising: a light source unit comprising at least one light emitting diode; a light guide plate disposed on one side of the light source unit and configured to conduct light of the light source unit, the light guide plate comprising a top and bottom relative a first surface and a second surface of the light guiding body, and a plurality of light guiding microstructures protruding upward from the first surface, each light guiding microstructure having a first extending from the first surface and surrounding a structural surrounding surface, and a structural end surface connected to the top edge of the structural surrounding surface; defining an angle between the structural surrounding surface of each light guiding microstructure and the first surface as a structural angle θ, the structural angle θ Is located outside the light guiding microstructure, and 90 ° ≦ θ ≦ 90 ° + θ _n , the θ _n is the critical angle of the total reflection that can be generated when the light is incident on the light guide plate; the width of the end face of the structure is w, the height of the light guiding microstructure is h, and 0≦w≦h×tan θ _n ; and a reflective sheet is located above the light guide plate, and the light passing through the light guide plate is again directed toward the light guide plate Reflecting to cause the light to be emitted downwards, the reflection sheet includes a plurality of The light guide plate protrudes from the reflective microstructure, and each of the reflective microstructures has an apex angle of δ and is 90° ≦ δ ≦ 170°. The underlying luminaire according to claim 10, wherein the light guiding microstructure has a shape of a trapezoidal column, a square column or a triangular column. The underlying luminaire according to claim 10, wherein the light guiding microstructure is arranged in a plurality of front, rear, left and right directions and is arranged on the light guiding body, and is in the shape of a pyramid, a quadrangle or a triangular pyramid.