Ceiling lamp

Abstract

A ceiling lamp comprises a diffusion cover located on a light source shell. The diffuser cover includes a polymeric body having diffusing particles and an array of conical protrusions or conical recesses. Each face of the cone-shaped projection or the cone-shaped recess has a texture or a matte finish, the Ra value of the surface roughness of which is in the range of 0.4 to 6.3 microns. This improves manufacturing efficiency.

Description

Technical Field

[0001] This utility model relates to ceiling lights. Background Technology

[0002] Ceiling lights typically include a housing containing a light source and a diffuser that forms the light output surface of the ceiling light. For example, the diffuser is designed to give the emitted light a Lambertian distribution.

[0003] An anti-glare ceiling light is also known, wherein the shade includes a diffuser and an anti-glare structure. Glare can be reduced by providing a light-emitting surface with a conical structure to the shade. The conical structure changes the light output direction through refraction and total internal reflection, thereby producing different light output distributions.

[0004] For example, WO 2015 / 104247 discloses a light diffuser plate with diffuse particles and a conical structure, the conical structure being considered to produce a surface roughness of 10 micrometers or greater.

[0005] Textured covers are formed, for example, by molding (e.g., injection molding). However, injection molded parts often have surface defects that can cause parts to fail quality control if the surface is intended to be smooth and defect-free.

[0006] This type of textured structure needs to be manufactured more efficiently while reducing the number of parts that fail to meet quality control standards. Utility Model Content

[0007] According to one aspect of the present invention, a ceiling light is provided, comprising:

[0008] shell;

[0009] The light source inside the casing; and

[0010] A diffuser located above the housing defines the light output window of the ceiling light, wherein the diffuser includes a light-transmitting polymer body that defines an inner surface and an outer surface.

[0011] The polymer matrix is ​​doped with diffuse particles.

[0012] The internal or external surfaces are formed with microstructures including an array of cone-shaped protrusions or concave depressions, and

[0013] Each facet of the cone-shaped protrusion or concave depression has a textured or matte finish, with a surface roughness Ra value ranging from 0.4 to 6.3 micrometers.

[0014] This ceiling light combines a cone-shaped structure with light-diffusing particles to control glare and the uniformity of light output. The size and density of the diffuse particles can be adjusted to achieve a balance between light output uniformity and glare suppression.

[0015] Using a cone-shaped structure with a smaller apex angle can significantly reduce glare, but it is more difficult to manufacture. Using diffuse particles allows a larger apex angle to be used to produce the desired optical properties, especially glare reduction.

[0016] The diffuser is preferably molded, for example, by injection molding. During injection molding, including demolding, the plastic surface is easily damaged by scratches, which are considered defects. However, with a textured or matte surface, scratches are not noticeable (in terms of optical performance or visible appearance) and therefore do not lead to quality control failures. This improves manufacturing efficiency. Matte or textured surfaces are applied to the faces of the conical structure (i.e., surface roughness is superimposed on the texture provided by the conical structure itself).

[0017] Ra value is the arithmetic mean roughness. For example, it ranges from 0.8 to 3.2 micrometers.

[0018] The apex angle of each cone-shaped structure may be in the range of 40 to 80 degrees. Therefore, they have steep cone-shaped sides.

[0019] The polymer matrix includes, for example, one, combination, or group of the following: polycarbonate, polymethyl methacrylate, polyalkyl methacrylate, polycarbonate, polystyrene, acrylic epoxy resin, acrylic polyurethane, acrylic polyester, cellulose ester, and multifunctional methacrylate. These are materials known to be suitable for use in brightening films.

[0020] The thickness of the polymer matrix is, for example, in the range of 2 mm to 4 mm. The pitch of the conical protrusions or conical recesses is, for example, in the range of 1 mm to 3 mm.

[0021] Diffuse particles include, for example, silicon dioxide.

[0022] The light output intensity (I) of a ceiling light at a position that forms a 65-degree angle with the normal. 65 The ratio of the light output intensity (I0) at the normal to the light output intensity (I) at the normal (I) 65 The glare percentage ( / I0) is preferably less than 40%, for example, less than 35%. This provides a measure of glare, where lower glare is achieved when a larger proportion of the light is emitted vertically downwards.

[0023] Conical protrusions or conical recesses may include truncated polygonal cones or truncated conical cones. These are easier to mold than sharp cones.

[0024] In one example, the microstructure is formed on the outer surface, and the apex angle is in the range of 50 to 80 degrees.

[0025] In another example, the microstructure is formed on the inner surface, and the apex angle is in the range of 40 to 75 degrees.

[0026] Diffuser shields can have an outward-arching shape. This not only provides an ideal aesthetic appearance but also offers a higher level of impact protection (resistance to external impacts).

[0027] The conical protrusions or conical recesses preferably have conical axes that are parallel to each other. Therefore, although the conical structures are dome-shaped, they remain parallel to each other.

[0028] The light source may include, for example, a printed circuit board that carries an LED array and lenses on the LEDs.

[0029] These and other aspects of this invention will be apparent and illustrated from the embodiments described below. Attached Figure Description

[0030] To better understand this invention and to more clearly show how to implement it, reference will now be made to the accompanying drawings by way of example only, in which:

[0031] Figure 1 A perspective view of the ceiling light from below is shown;

[0032] Figure 2 Shown from above Figure 1 A perspective view of the ceiling light in the picture;

[0033] Figure 3 An exploded view is shown;

[0034] Figure 4 Various possible examples of cone-shaped structures are shown;

[0035] Figure 5 A measure used to explain glare;

[0036] Figure 6 The light output distribution at a 60-degree apex angle is shown;

[0037] Figure 7 The light output distribution at an 80-degree apex angle is shown;

[0038] Figure 8 An example of a protruding cone-shaped structure formed as a cone based on a truncated square is shown;

[0039] Figure 9 The cross-section of a cone based on a truncated square is shown;

[0040] Figure 10 A protruding square-based cone with sidewalls having surface roughened is shown;

[0041] Figure 11 It shows the relationship with Figure 10 The same image, but with additional boundary lines to make the cone shape easier to display;

[0042] Figure 12 It shows the relationship with Figure 11 The same image, but scaled down to show the entire array of cones more comprehensively;

[0043] Figure 13 This shows that a diffuser can have an outwardly arched surface;

[0044] Figure 14 Used to explain the manufacturing method of the cover;

[0045] Figure 15 The light output characteristics of the curved cover for a ceiling light with a 60-degree apex angle are shown.

[0046] Figure 16 An example of a cone with an inward-facing, truncated square base is shown;

[0047] Figure 17 The light output distribution for a 60-degree apex angle and an inward-facing convex shape is shown; and

[0048] Figure 18 The light output distribution for a 75-degree apex angle and an inward-facing convex shape is shown. Detailed Implementation

[0049] The present invention will be described with reference to the accompanying drawings.

[0050] It should be understood that while the detailed description and specific examples illustrate exemplary embodiments of the apparatus, system, and method, these descriptions and specific examples are for illustrative purposes only and are not intended to limit the scope of the present invention. These and other features, aspects, and advantages of the apparatus, system, and method of the present invention will be better understood from the following description, the appended claims, and the accompanying drawings. It should be understood that these drawings are merely schematic and not drawn to scale. It should also be understood that the same reference numerals are used throughout the drawings to denote the same or similar parts.

[0051] This invention provides a ceiling light comprising a diffuser located on a light source housing. The diffuser comprises a polymer body having an array of diffuse particles and conical protrusions or recesses. Each facet of the conical protrusions or recesses has a textured or matte finish with a surface roughness Ra value ranging from 0.4 to 6.3 micrometers. This improves manufacturing efficiency.

[0052] Figure 1 A perspective view of the ceiling light 10 from below is shown. It includes a housing having a bracket 12 for ceiling mounting and a top housing portion 14. A diffuser 100 is disposed on the housings 12, 14 to form a closed housing cavity. The diffuser 100 defines the light output window of the ceiling light.

[0053] Figure 2 A perspective view of the ceiling light 10 as seen from above is shown.

[0054] This utility model specifically relates to a diffuser 100.

[0055] Figure 3 An exploded view of the ceiling light is shown. The figure shows that housings 12 and 14 define an internal space in which a light source 18 is disposed. The light source 18 is in the form of a printed circuit board 20, which carries an LED array and lenses 22 on the LEDs.

[0056] The diffuser 100 includes a transmissive polymer body that defines an inner surface 100a (facing the interior space of the housing) and an outer surface 100b (facing the space to be illuminated by the ceiling light).

[0057] The polymer matrix is ​​doped with diffuse particles. Therefore, the polymer matrix comprises a matrix material and embedded particles. The matrix material is, for example, polycarbonate. Other examples are polymethyl methacrylate, polyalkyl (meth)acrylate, polycarbonate, polystyrene, acrylic epoxy resin, acrylic polyurethane, acrylic polyester, cellulose ester, and multifunctional (meth)acrylate. The cover can be formed from a combination of various materials.

[0058] Diffuse particles can be, for example, SiO2. However, more generally, diffuse particles can be made of organic or inorganic materials. Organic materials, such as silica and methyl methacrylate, will provide higher transmittance. Examples of inorganic materials include TiO2, CaCO3, and BaSO4.

[0059] The particle radius is, for example, in the range of 1 μm to 10 μm. For a lampshade thickness of 2 mm, the weight percentage of diffuse particles can be less than about 3%. As the lampshade thickness increases, the density of diffuse particles can be reduced to maintain the same optical performance.

[0060] Furthermore, the inner surface 100a or the outer surface 100b is formed with a microstructure including an array of conical protrusions or conical recesses. These conical protrusions or conical recesses have a textured or (random) matte finish with a surface roughness Ra value in the range of 0.4 to 6.3 micrometers.

[0061] This ceiling light combines a conical structure with light-diffusing particles to control glare and the uniformity of light output. To achieve a balance between light output uniformity and glare suppression, the size and bulk density of the particles, as well as the apex angle of the conical microstructure, can be selected.

[0062] Using a cone-shaped structure with a smaller apex angle can significantly reduce glare, but cone-shaped structures are more difficult to manufacture. Using diffuse particles allows for a larger apex angle to achieve the desired optical effect.

[0063] Textured or matte finishes are characterized by their Ra value. Ra, also known as arithmetic mean roughness, is a parameter characterizing surface roughness. Ra is a numerical representation of the average deviation of a point on a surface from a specified reference line (or plane), and is typically measured in micrometers.

[0064] A reference line (often called the mean line or center line) is also defined. This line represents the theoretically ideal surface, and the actual surface deviation is measured by it. The Ra value is the average absolute value of the deviation of the profile from the reference line over the evaluation length. Ra is expressed as:

[0065] Ra=(1 / L)∫|z(x)|dx

[0066] in:

[0067] Ra is the arithmetic mean roughness.

[0068] L is the evaluation length (the length on which measurements are averaged).

[0069] z(x) represents the deviation of the surface profile at position x from the reference line.

[0070] The integral ∫|z(x)|dx represents the sum of absolute deviations along the evaluation length.

[0071] The diffuser is preferably molded, such as through injection molding. During injection molding, including demolding, scratches can easily appear on the plastic surface, and these scratches are considered defects. However, with a textured or randomly matte surface, scratches are not visually or optically noticeable and therefore do not lead to quality control failures. This improves manufacturing efficiency.

[0072] In addition, surface roughness produces additional light scattering, thereby improving the uniformity of illumination from the luminous surface of the lamp.

[0073] The diffuser alters the output characteristics of the Lambertian profile light (from the LED and its lens).

[0074] Various cone-shaped structures can be used to modify the light profile. Figure 4 Some examples are shown.

[0075] exist Figure 4 In the diagram, 102a shows a cone based on a square, 102b shows a cone, and 102c shows a cone based on a hexagon. These are all convex structures, i.e., cone-shaped protrusions. However, they can also be formed as concave structures, i.e., cone-shaped recesses. The microstructures are used to reduce glare from ceiling lights.

[0076] Figure 5 A metric used to explain glare. It shows the relationship between light output intensity (y-axis) and the angle formed with respect to the direction of normal light emission (x-axis). Therefore, for a horizontally mounted ceiling light, angle zero is vertically downward.

[0077] Glare measurement is based on the intensity I at 65 degrees (i.e., 25 degrees below the horizontal). 65 The ratio between the intensity I0 in the normal direction (i.e., vertically downwards) and the intensity I0 in the normal direction.

[0078] Therefore, I 65 / I0 can be used as a possible evaluation parameter for glare. If the light distribution is a Lambertian distribution, then I 65 / I0 is approximately 41%, I 65 The larger the / I0 value, the more severe the glare.

[0079] Figure 1 below shows the glare values ​​and beam angles for different apex angles of the cone-shaped protrusion.

[0080] Vertex angle (°) <![CDATA[I 65 / I0]]> Beam angle (°) 50 36％ 108.4 60 36％ 108.9 70 37％ 112.5 80 40％ 116.8 90 43％ 121.8 100 47％ 125.6

[0081] The above diagram 1 shows a square-based cone facing outwards and located on the outer surface 100b of the enclosure.

[0082] The beam angle is the angle of the light output distribution at 50% of the peak intensity.

[0083] A wider beam angle results in a wider light coverage area and more severe glare. Narrower apex angles create a steeper, cone-shaped surface, resulting in lower glare and a smaller beam angle, but are more difficult to manufacture.

[0084] Figure 6 The light output distribution at a 60-degree apex angle is shown. The beam angle can be seen from the intersection with the center intensity band (+ / -54.4 degrees).

[0085] Figure 7 The light output distribution with an apex angle of 80 degrees is shown. The beam angle can be seen again at the intersection with the center intensity band (+ / -58.4 degrees).

[0086] A vertex angle of less than 80 degrees can achieve the required lower I 65 / I0 values, such as below 40%, but cone-shaped structures with small apex angles may be difficult to manufacture and prone to damage during use.

[0087] To solve this problem, a truncated cone can be used instead of a pointed cone, or gaps can be set between the structures.

[0088] Figure 8 An example of a protruding cone-shaped structure formed as a truncated square cone is shown. The protruding cone 102 has sidewalls 104 and a flat top 106, as... Figure 9 The cross-section is shown. The groove angle θ (equal to the apex angle, i.e., the roof angle) is also shown.

[0089] In this example, the microstructure is formed on the outer surface and therefore faces downwards.

[0090] Figure 2 shows some exemplary dimensions for square-based cones / prisms (first column data), truncated square-based cones (second column data), and spaced arrays of square-based cones (third column data). The cone pitch is 1.5 mm in each case, but more generally, the pitch may range from 1 mm to 3 mm. The structural height is shown as ranging from 1 mm to 1.3 mm. More generally, the overall shroud thickness ranges from 2 mm to 4 mm.

[0091] Pitch of a prism 1.5mm 1.5mm 1.5mm Spacing of prisms 0 0 0.1mm The height of the prism 1.299mm 1mm 1.2124mm ridge of a prism 60° 60° 60° Beam angle 109° 109° 113° <![CDATA[I 65 / I0]]> 36％ 36％ 38％ efficiency 81％ 81％ 81％

[0092] Frustal cone-shaped structures with small apex angles (ridge angles) can be formed. Diffuse particles (rather than transparent plates) mean that the optical properties between polygonal cones and frustal versions of the same cone are very similar. For example, a frustal cone-shaped structure with a 60-degree apex angle and a pure cone-shaped equivalent have the same Ig. 65 / I0 and beam angle values ​​are shown in Figure 2. Increasing the spacing between structures improves manufacturability, but I 65 The / I0 value is slightly larger than when there is no spacing.

[0093] As mentioned above, the cone-shaped structure has surface roughness. Figure 10 A recessed, square-based cone 102 is shown, having sidewalls 104 with a surface roughness 110 applied.

[0094] The surface roughness Ra value of 110 is in the range of 0.4 to 6.3 micrometers, for example, in the range of 0.8 to 3.2 micrometers. The diffuser is preferably injection molded. By having a textured matte surface, scratches are less noticeable, thus preventing quality control failures. This improves manufacturing efficiency.

[0095] Figure 11 It shows the relationship with Figure 10Same image, but with additional boundary lines to more easily show the cone shape.

[0096] Figure 12 It shows the relationship with Figure 11 Same image, but scaled down to show the entire array of cones more completely.

[0097] Figure 13 The diffuser 100 is shown to have an outwardly arched surface. The conical structure maintains a vertical orientation, independent of the orientation and curvature of the plate surface. In other words, the cone axes are parallel to each other. For a conventional upright cone, the cone axis is perpendicular to the cone base. Such a conical structure provides rotationally symmetric optical functionality.

[0098] However, tilted cones can be considered, which will provide less rotationally symmetric optical functionality. In this case, the cone axis (between the base center and the apex) may not be perpendicular to the base, but the cone axes are preferably parallel to each other again.

[0099] The arched surface enhances impact resistance and is a shape that is popular with consumers.

[0100] Figure 14 The method for manufacturing the cover 100 is used to explain the production of a cover with a conical recess, such as... Figures 10 to 12 As shown, it illustrates a metal mold 120 in which a series of straight, parallel V-shaped grooves 122 are formed using a wedge-shaped cutting tool 130.

[0101] The first groove is formed by creating a V-shaped groove along a first direction (as shown in the figure). For each V-shaped groove, the angle β between the cut surface (bevel) and the horizontal surface is equal to 90 - θ / 2, where θ is the apex angle. This relationship is as follows: Figure 14 As shown.

[0102] The cover is then rotated 90 degrees relative to the direction of movement of the cutting tool (around the normal direction of the plate). The direction of movement of the tool can be rotated, or the cover can also be rotated. This forms a second V-shaped groove perpendicular to the first groove.

[0103] The end result is a set of conical protrusions. When used as a mold surface, the molded cover will form a set of conical recesses.

[0104] To create a matte or textured finish, surface roughness can be achieved through, for example, etching a mold. Etching can be performed using chemical etching or electrical discharge / plasma etching.

[0105] To create a truncated cone-shaped indentation, a device with such... Figure 8 The mold surface has the shape shown. This mold can be formed using a V-shaped cutter, but the grooves will be spaced apart.

[0106] For round ceiling lights, due to symmetry, the direction chosen for the first V-shaped groove can be any direction. For rectangular ceiling lights, the direction chosen in the first step can be along the short side of the rectangle or along the long side of the rectangle.

[0107] Whether the cover is curved or flat, a vertex angle of less than 80 degrees can be used to implement I. 65 The expected value of / I0, such as I 65 / I0≤40%.

[0108] For example, Figure 15 This shows the case where the apex angle is 60 degrees and I 65 The light output characteristics of the curved shade of the ceiling light are / I0=33%.

[0109] The example above shows an outward-facing microstructured surface.

[0110] Figure 16 An example of an inward-facing, truncated square-based protruding cone is shown. Light from the LED lens now illuminates the back of the microstructure of the cover and exits from the smooth top surface of the cover.

[0111] Figure 3 shows data on the microstructure, which is equivalent to that in Figure 1 but located on the inward surface.

[0112] Vertex angle (°) <![CDATA[I 65 / I0]]> Beam angle (°) 40 36％ 109.6 50 32％ 101.9 60 32％ 100.8 70 36％ 109.3 75 40％ 118.3 80 44％ 125.9 90 56％ 138.1 100 60％ 140.4

[0113] This data pertains to a protruding cone with the same shape as in Figure 1, but located on the inner surface 100a of the cover.

[0114] In this case, the expected value I can be obtained when the vertex angle is less than 75 degrees. 65 / I0≤40%.

[0115] Therefore, when the microstructure is formed on the outer surface 100b, the apex angle is, for example, in the range of 50 degrees to 80 degrees. When the microstructure is formed on the inner surface 100a, the apex angle is, for example, in the range of 40 degrees to 75 degrees.

[0116] Figure 17 The light output distribution for a 60-degree apex angle and an inward-facing convex shape is shown.

[0117] Figure 18 The light output distribution for a 75-degree apex angle and an inward-facing convex shape is shown.

[0118] Therefore, this invention also provides a method for manufacturing a diffuser for a ceiling light. The method includes: fabricating a metal mold by cutting a first linear groove on a mold surface using a wedge cutter and cutting a second intersecting linear recess using the wedge cutter after rotating the metal mold relative to the cutter; forming a surface roughness on the mold surface, the surface roughness having an Ra value in the range of 0.4 to 6.3 micrometers; forming a mold cavity for injection molding, wherein the mold cavity includes a mold surface; injecting a polymer liquid having diffuse particles into the mold cavity and solidifying the liquid to form a solid polymer body; and demolding the solid polymer body from the mold cavity.

[0119] This method of forming a mold and performing injection molding provides a conical protrusion with the desired surface roughness. If the linear grooves are spaced apart, the mold will produce a conical protrusion with a flat top.

[0120] After molding, the cover will include a conical recess with a flat base. Surface roughness is achieved, for example, by etching. Etching can be chemical etching or electrical discharge / plasma etching.

[0121] When practicing the claimed invention, those skilled in the art can understand and implement various modifications to the disclosed embodiments by studying the accompanying drawings, the disclosure, and the appended claims. In the claims, the word "comprising" does not exclude other elements or steps, and the indefinite articles "a" or "an" do not exclude a plurality.

[0122] The mere fact that certain measures are referenced in mutually different dependent claims does not imply that a combination of these measures cannot be used advantageously.

[0123] If the term "suitable" is used in the claims or description, it should be noted that the term "suitable" is equivalent to the term "configured as". If the term "arranged" is used in the claims or description, it should be noted that the term "arranged" is equivalent to the term "system", and vice versa.

[0124] Any reference numerals in the claims should not be construed as limiting the scope.

Claims

1. A ceiling light, characterized in that, include: Outer shell (12, 14); A light source (18) located inside the housing; as well as A diffuser (100) is located on the housing (12, 14) and defines the light output window of the ceiling light. The diffuser (100) includes a light-transmitting polymer body that defines an inner surface (100a) and an outer surface (100b). The polymer matrix is ​​doped with diffuse particles. The inner surface (100a) or the outer surface (100b) is formed with a microstructure comprising an array of conical protrusions (102) or conical recesses, and Each face of the conical protrusion or conical recess has a textured or matte finish, with a surface roughness (110) Ra value ranging from 0.4 to 6.3 micrometers.

2. The ceiling light according to claim 1, characterized in that, The Ra value is in the range of 0.8 to 3.2 micrometers.

3. The ceiling light according to claim 1 or 2, characterized in that, The apex angle (θ) of each cone-shaped structure is in the range of 40 degrees to 80 degrees.

4. The ceiling light according to claim 1 or 2, characterized in that: The thickness of the polymer matrix is ​​in the range of 2 mm to 4 mm; and / or The pitch of the conical protrusion (102) or the conical recess is in the range of 1 mm to 3 mm.

5. The ceiling light according to claim 1 or 2, characterized in that, The diffuse particles comprise silicon dioxide.

6. The ceiling light according to claim 1 or 2, characterized in that, The light output intensity (I) of the ceiling light at a position at a 65-degree angle to the normal. 65 The ratio of the light output intensity (I0) at the normal to the light output intensity (I) at the normal (I) 65 / I0) is less than 40%.

7. The ceiling light according to claim 6, characterized in that, The ratio (I) 65 / I0) is less than 35%.

8. The ceiling light according to claim 1 or 2, characterized in that, The conical protrusion (102) or the conical recess includes a truncated polygonal cone or a truncated conical cone.

9. The ceiling light according to claim 3, characterized in that, The microstructure is formed on the outer surface (100b), and the apex angle is in the range of 50 degrees to 80 degrees.

10. The ceiling light according to claim 3, characterized in that, The microstructure is formed on the inner surface (100a), and the apex angle is in the range of 40 degrees to 75 degrees.

11. The ceiling light according to claim 1 or 2, characterized in that, The diffuser has an outwardly arched shape.

12. The ceiling light according to claim 10, characterized in that, The conical protrusion or the conical recess has conical axes that are parallel to each other.

13. The ceiling light according to claim 1, 2, or 12, characterized in that, The light source (18) includes a printed circuit board (20) that carries an LED array and a lens (22) located on the LED.

Images