Classifications

• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
  • G01S5/00—Position-fixing by co-ordinating two or more direction or position line determinations; Position-fixing by co-ordinating two or more distance determinations
  • G01S5/16—Position-fixing by co-ordinating two or more direction or position line determinations; Position-fixing by co-ordinating two or more distance determinations using electromagnetic waves other than radio waves
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
  • B29C64/00—Additive manufacturing, i.e. manufacturing of three-dimensional [3D] objects by additive deposition, additive agglomeration or additive layering, e.g. by 3D printing, stereolithography or selective laser sintering
  • B29C64/10—Processes of additive manufacturing
  • B29C64/106—Processes of additive manufacturing using only liquids or viscous materials, e.g. depositing a continuous bead of viscous material
  • B29C64/118—Processes of additive manufacturing using only liquids or viscous materials, e.g. depositing a continuous bead of viscous material using filamentary material being melted, e.g. fused deposition modelling [FDM]
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B05—SPRAYING OR ATOMISING IN GENERAL; APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
  • B05D—PROCESSES FOR APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
  • B05D5/00—Processes for applying liquids or other fluent materials to surfaces to obtain special surface effects, finishes or structures
  • B05D5/06—Processes for applying liquids or other fluent materials to surfaces to obtain special surface effects, finishes or structures to obtain multicolour or other optical effects
  • B05D5/061—Special surface effect
  • B05D5/063—Reflective effect
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
  • B29C64/00—Additive manufacturing, i.e. manufacturing of three-dimensional [3D] objects by additive deposition, additive agglomeration or additive layering, e.g. by 3D printing, stereolithography or selective laser sintering
  • B29C64/10—Processes of additive manufacturing
  • B29C64/106—Processes of additive manufacturing using only liquids or viscous materials, e.g. depositing a continuous bead of viscous material
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29D—PRODUCING PARTICULAR ARTICLES FROM PLASTICS OR FROM SUBSTANCES IN A PLASTIC STATE
  • B29D11/00—Producing optical elements, e.g. lenses or prisms
  • B29D11/0073—Optical laminates
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29D—PRODUCING PARTICULAR ARTICLES FROM PLASTICS OR FROM SUBSTANCES IN A PLASTIC STATE
  • B29D11/00—Producing optical elements, e.g. lenses or prisms
  • B29D11/0074—Production of other optical elements not provided for in B29D11/00009- B29D11/0073
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B33—ADDITIVE MANUFACTURING TECHNOLOGY
  • B33Y—ADDITIVE MANUFACTURING, i.e. MANUFACTURING OF THREE-DIMENSIONAL [3-D] OBJECTS BY ADDITIVE DEPOSITION, ADDITIVE AGGLOMERATION OR ADDITIVE LAYERING, e.g. BY 3-D PRINTING, STEREOLITHOGRAPHY OR SELECTIVE LASER SINTERING
  • B33Y10/00—Processes of additive manufacturing
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B33—ADDITIVE MANUFACTURING TECHNOLOGY
  • B33Y—ADDITIVE MANUFACTURING, i.e. MANUFACTURING OF THREE-DIMENSIONAL [3-D] OBJECTS BY ADDITIVE DEPOSITION, ADDITIVE AGGLOMERATION OR ADDITIVE LAYERING, e.g. BY 3-D PRINTING, STEREOLITHOGRAPHY OR SELECTIVE LASER SINTERING
  • B33Y80/00—Products made by additive manufacturing
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F21—LIGHTING
  • F21V—FUNCTIONAL FEATURES OR DETAILS OF LIGHTING DEVICES OR SYSTEMS THEREOF; STRUCTURAL COMBINATIONS OF LIGHTING DEVICES WITH OTHER ARTICLES, NOT OTHERWISE PROVIDED FOR
  • F21V1/00—Shades for light sources, i.e. lampshades for table, floor, wall or ceiling lamps
  • F21V1/26—Manufacturing shades
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F21—LIGHTING
  • F21V—FUNCTIONAL FEATURES OR DETAILS OF LIGHTING DEVICES OR SYSTEMS THEREOF; STRUCTURAL COMBINATIONS OF LIGHTING DEVICES WITH OTHER ARTICLES, NOT OTHERWISE PROVIDED FOR
  • F21V7/00—Reflectors for light sources
  • F21V7/04—Optical design
  • F21V7/048—Optical design with facets structure
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29L—INDEXING SCHEME ASSOCIATED WITH SUBCLASS B29C, RELATING TO PARTICULAR ARTICLES
  • B29L2011/00—Optical elements, e.g. lenses, prisms
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29L—INDEXING SCHEME ASSOCIATED WITH SUBCLASS B29C, RELATING TO PARTICULAR ARTICLES
  • B29L2011/00—Optical elements, e.g. lenses, prisms
  • B29L2011/0083—Reflectors
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29L—INDEXING SCHEME ASSOCIATED WITH SUBCLASS B29C, RELATING TO PARTICULAR ARTICLES
  • B29L2031/00—Other particular articles
  • B29L2031/747—Lightning equipment
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29L—INDEXING SCHEME ASSOCIATED WITH SUBCLASS B29C, RELATING TO PARTICULAR ARTICLES
  • B29L2031/00—Other particular articles
  • B29L2031/747—Lightning equipment
  • B29L2031/7472—Lampshades

Definitions

• the present invention relates to 3D printing of objects with at least one wall having a first surface and a second, opposite surface, wherein said first surface is intended to serve as an optical functional surface.
• Digital fabrication has begun to transform the nature of global manufacturing.
• 3D printing One of the aspects of digital fabrication is 3D printing.
• 3D printing can also be used in producing molds which can then be used for replicating objects.
• polyjet technique For this purpose the use of polyjet technique has been suggested.
• This technique makes use of layer by layer deposition of photo- polymerisable material which is cured after each deposition to form a solid structure. While this technique produces smooth surfaces the photo curable materials are not very stable and they also have relatively low thermal conductivity to be useful for injection molding applications.
• FDM printers use a thermoplastic filament, which is heated to its melting point and then extruded, layer by layer, to create a three dimensional object. FDM printers are relatively fast and can be used for printing complicated object.
• FDM is also an ideal printing process especially when printing conical hemispherical or faceted objects which are used in lighting.
• US20140070445A1 describes a method for FDM to produce an object and various ways of varying a deposit rate of the build material during the extrusion onto an exterior wall of the object to create a non-uniform surface texture on the exterior wall. For this purpose they suggest varying the extrusion rate, distance in a direction during extrusion, and varying the velocity in x-y direction.
• this and other objects are achieved by a method for 3D printing an object with at least one wall having a first surface and a second, opposite surface, wherein the first surface is intended to serve as an optical functional surface, the method comprising:
• a surface smoothness of the first surface the portion is greater than a surface smoothness of the second surface in the portion.
• the 3D object is thus oriented during printing such that the first surface, intended to be used as an optical functional surface, faces away from the x-y plane, i.e. typically away from the support or platform on which the 3D object is printed upon.
• the first surface becomes smoother than the second, opposite surface of the wall.
• the present invention is based on the insight that when a non solid object including a wall formed by consecutive layers of printing material, the surface properties of this wall will depend on the orientation of the object during printing. If the wall is vertical (e.g. a vertical cylinder), the inside and outside surfaces of the wall will have the same roughness. However, when the wall is inclined with respect to the x-y plane, such as a tilted cylinder or a conical object, any surface facing the platform is rougher than the opposite surface facing away from the platform.
• an optical functional surface e.g. a surface used for collimation of light or esthetics, may be oriented so that it is printed more smoothly than the opposite surface of the wall.
• the wall which is formed by consecutive tracks of printed material will have a width (in the x-y plane) defined by the diameter of the nozzle. Typically, this will thus be a relatively thin wall. Still, the width of the track (and the wall) is preferably greater than the thickness of each layer, in order to achieve the desired smoothness. According to a preferred embodiment, a ratio of the nozzle diameter and the thickness of the printed layer is greater than three, or even greater than five.
• 3D objects may present walls with surfaces that are possible to orient such that one surface of the wall is smoother than the other surface.
• the invention is particularly useful when the wall forms a contour surrounding a hollow interior.
• the wall may simply be a small part of a more complex object.
• the only condition in order to make the invention relevant is that the wall is formed by a plurality of tracks printed onto each other.
• the difference in surface smoothness between the first and second surfaces will be a function also on the inclination of the wall or portion of the wall with respect to the x-y plane.
• the wall is perpendicular to the surface or makes a small angle (less than 0-5 degrees) with respect to the normal (z-axis) there is not much difference in the quality of the inner and outer surfaces.
• the angle between the tangent (or tangent surface) of the first surface and the normal (z-axis) is in the range 5-45 degrees, and preferably in the range 5-35 degrees.
• the smoothness obtained by ensuring the correct orientation during printing according to the present invention is sufficient.
• the functional surface will be coated in order to obtain the desired properties.
• the smoother surface obtained by the present invention will be highly advantageous for such coating.
• Figures la and lb schematically illustrate FDM printing of a conical object in two different orientations.
• Figure 2a shows an enlarged and partly cut away perspective view of the FDM printing in figure lb.
• Figure 2b is an enlarged detail of figure 2a.
• Figures 3a and 3b are sectional views of a first 3D object in two different orientations.
• Figures 4a and 4b are sectional views of a second 3D object in two different orientations.
• Figure 5 is a perspective view of a third 3D object.
• Figures la and lb show FDM printing of an object 1, in the illustrated case in the shape of a cone.
• FDM printing is well known in the art, and will not be described in detail here.
• an FDM printer has a printing head 10 including a feeder 11 for feeding a filament 12 of thermoplastic material through a channel in a nozzle 13.
• a heater (not shown) configured to heat the filament to its melting point, such that the thermoplastic is extruded and deposited by the nozzle in melted form.
• the printing head 10 is arranged to be moved in an x-y plane while depositing the melted thermoplastic to print one layer of the object.
• the object is built layer by layer in the z-direction.
• the object is typically printed on some kind of support or substrate 14.
• the object 1 has a wall 2, here a contour wall surrounding a hollow interior 3. The interior may be closed in its top and/or bottom end, but may also be open.
• the wall 2 has a first surface 4, 4' facing away from the substrate, and a second surface 5, 5' facing towards the substrate.
• the object - in the illustrated case the cone - is printed with an orientation such that an optical functional surface of the object faces away from the substrate (i.e. it is the first surface).
• An optical functional surface in this context is a surface intended to interact with light in a desired manner, and may be a surface intended to be reflective or esthetic.
• the first surface will be smoother than the second surface.
• the first surface i.e. the smooth surface to be used as an optical functional surface
• the first surface is the outside 4 of the cone.
• the first surface i.e. the smooth surface to be used as an optical functional surface
• the inside 4' of the cone is the inside 4' of the cone.
• Figure 2a shows how the nozzle of a printer head 10 is moved around a predefined path 15, here substantially circular, while depositing a track 16 of melted filament on previously deposited layers.
• each layer of the wall may be printed in discrete movements, one at a time, or the wall may be printed with one single spiral movement of the printer head. This technique is known as a "spiralize" function, and is available in some 3D- printing software.
• the accumulated effect of the sharp edge 18 is that the surface 5' facing the substrate (i.e. the surface where the sharp edges 18 are located) will be rougher than the opposite surface 4' facing away from the substrate 14, where the consecutive layers 16, 17 form a more regular step-pattern.
• the amount of "sag”, and thus the roughness of the surface, will depend on several factors, including the diameter of the nozzle 13 defining the width of the printed track 16, and the thickness of the printed track 16. In the example illustrated in figure 2a, it is clear that the width w of track 16 is significantly greater than the thickness d of the track 16, approximately a factor five greater. Therefore, the material (the melted filament 12) is pressed (by the nozzle 13) during printing to form the flat track 16, rather like when applying a thin layer of toothpaste on a toothbrush. In portions where there is no support to counter-act this pressure, the track will "sag” as discussed above, just like the toothpaste will be forced beyond the upper surface of the toothbrush if you apply it outside the edges of the brush.
• the smoother surface of the wall 2, i.e. the surface 4, 4' facing away from the substrate, is intended to be used as an optical functional surface.
• the surface may be coated with a suitable coating to create or improve the surface properties.
• coatings may be used to improve smoothness, make the surface reflective or diffusive, or to simply paint the surface.
• the 3D object in figures 3a-3b is rotational symmetrical.
• the inside of the object is smoother than the outside, and the object may be used e.g. as a light collimator in a luminaire.
• the outside is smoother than the inside, and the object may be used e.g. as a lamp shade.
• the 3D object in figures 4a-4b is also rotational symmetrical, but contrary to the objects in figures 1-3 the object in figures 4a-4b is closed in one end, and has the shape of a semi-sphere.
• the inside of the semi-sphere is smoother than the outside, and the semi-sphere may be used e.g. as a collimator or reflector.
• the outside is smoother than the inside.
• Such an object for example can be filled with index matching polymer to be used as lens.
• the object in figure 5 is not rotational symmetrical and it has indentations, but similar to the object in figure 4 it is closed in one end to form a dome shape.
• the inside of the dome-shaped object will be smoother than the outside, and the object may be used as a reflector/collimator.
• any 3D-printed object having a wall formed by consecutive tracks printed onto each other can be oriented during printing according to the invention to ensure that one surface of the wall is smoother than the other.
• the wall may comprise several facets, or portions, each having a different tangent (or tangent surface). In this case, the angle between the tangent and the normal (z-axis) may be different, resulting in different smoothness for different portions of the wall.

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• Engineering & Computer Science (AREA)
• Manufacturing & Machinery (AREA)
• Materials Engineering (AREA)
• Chemical & Material Sciences (AREA)
• Physics & Mathematics (AREA)
• Mechanical Engineering (AREA)
• Optics & Photonics (AREA)
• General Engineering & Computer Science (AREA)
• Health & Medical Sciences (AREA)
• Ophthalmology & Optometry (AREA)
• General Physics & Mathematics (AREA)
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• 2016
  • 2016-11-07 US US15/773,185 patent/US11072110B2/en active Active
  • 2016-11-07 PL PL16794276T patent/PL3374182T3/pl unknown
  • 2016-11-07 CN CN201680065247.9A patent/CN108349234B/zh active Active
  • 2016-11-07 EP EP16794276.2A patent/EP3374182B1/en active Active
  • 2016-11-07 WO PCT/EP2016/076831 patent/WO2017080951A1/en not_active Ceased
  • 2016-11-07 JP JP2018523482A patent/JP6907200B2/ja active Active

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