Method for additive manufacturing of transparent lenses for lighting fixtures

Abstract

A method for manufacturing a three-dimensional lens (90) includes inputting a lens template into a controller (200); depositing a first layer (27) of lens material (25) onto a work surface (70) according to the lens template; and continuously depositing additional filamentary layers (27) of the lens material (25) onto the first layer (27). The deposition of the layers (27) of lens material (25) is performed according to the lens template to create the three-dimensional lens (90) having a specific transmission scattering profile for transmitted light.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This nonprovisional patent application claims priority to and the benefit of U.S. Patent Application No. 63 / 020,574, filed May 6, 2020. The entire contents of said application are hereby incorporated herein by reference. Technical Field

[0003] This disclosure was made with government support under Cooperative Agreement #DE-EE0008722 awarded by the Department of Energy. The government has certain rights in the invention. This disclosure relates to a method for making a transparent lens for a lamp using an additive manufacturing process. More specifically, this disclosure relates to a method for making a transparent polyamide lens for a lamp using fused deposition modeling (FDM). Background Art

[0004] Silicone lenses for lamps or LED fixtures are produced using known molding or extrusion techniques. Using these molding techniques to produce lenses of varying shapes and / or sizes requires the use of different molds and mold tools. This results in high production costs for these lenses and significant lead times when switching production between lenses of varying shapes and / or sizes. Consequently, these molded lenses have very limited design freedom, as each different lens requires a new set of molds.

[0005] These are just some of the shortcomings that exist in current methods of manufacturing clear lenses for lighting fixtures. Summary of the Invention

[0006] An embodiment of a method for manufacturing a three-dimensional lens for a lighting fixture uses an additive manufacturing process. The method includes: inputting a lens template into a controller, depositing a first filamentary layer of transparent polyamide material onto a work surface according to the lens template; and continuously depositing additional filamentary layers of transparent polyamide material onto the first layer according to the lens template to build the three-dimensional lens. The lens template further includes a transmission scattering profile for transmitted light.

[0007] In one embodiment, the method further comprises at least one post-printing process. In one embodiment, one or more fillers are added to the transparent polyamide material to control the softness of the transmitted light. In one embodiment, the transparent polyamide material is tinted with a color. In one embodiment, the three-dimensional lens comprises one or more smooth surfaces. In another embodiment, at least a portion of the three-dimensional lens is built on a support material, and the support material is removed after the deposition of the transparent polyamide material is completed. In other embodiments, the first filamentary layer and the additional filamentary layer are substantially parallel to each other.

[0008] Another embodiment of a method for manufacturing a three-dimensional lens includes: inputting a lens template into a controller, depositing a first layer of lens material onto a work surface according to the lens template; and successively depositing additional layers of lens material onto the first layer according to the lens template to build up the three-dimensional lens. The lens template further includes a transmission scattering profile for transmitted light.

[0009] In an embodiment, the three-dimensional lens is used in a lamp. In an embodiment, the method further comprises at least one post-printing process. In an embodiment, at least a portion of the three-dimensional lens is built on a support material, and the support material is removed after the deposition of the lens material is completed. In an embodiment, the first layer and the additional layer are substantially parallel to each other. In an embodiment, the lens material is a transparent polyamide. In an embodiment, the transparent polyamide material includes one or more fillers to control the softness of the transmitted light. In an embodiment, the transparent polyamide material is tinted with a color. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] A more detailed description of the invention, briefly summarized above, may be made with reference to embodiments, some of which are illustrated in the accompanying drawings. However, it should be noted that the drawings illustrate only typical embodiments of the invention and are therefore not to be considered limiting of the scope of the invention, as the invention admits to other equally effective embodiments. Therefore, to further understand the spirit and objectives of the present invention, reference is made to the following detailed description, which should be read in conjunction with the accompanying drawings, in which:

[0011] Figure 1 is a schematic diagram of an example of an FDM printing apparatus for depositing printing material;

[0012] Figures 2a to 2c is a schematic diagram of material deposition during various stages of the FDM printing process;

[0013] Figure 3a is a schematic diagram of a layer of printed material deposited on a working surface;

[0014] Figure 3b Another schematic diagram

[0015] Figure 4 is a depiction of the transmission scattering of a non-printed acrylic lens;

[0016] Figure 5a An example of printing a transmission scattering pattern of a smooth surface is shown, where the nozzle of the FDM printing device is set to +45°;

[0017] Figure 5b An example of a transmission scattering pattern of a printed rough surface is shown, where the nozzle of the FDM printing device is set to -45°;

[0018] Figure 5c is a graph showing the effect of various printing parameters on light transmission scattering;

[0019] Figure 6 is a reference mark visible to the naked eye; and

[0020] Figures 7a to 7c Three examples are shown showing how varying certain printing parameters can change the optical properties of a printed lens. DETAILED DESCRIPTION

[0021] The following description relates to various embodiments of a method for additively manufacturing a transparent polyamide lens for a lamp. It will be apparent that these embodiments are merely examples and that there may be numerous variations and modifications to implement the aspects of the invention discussed herein. Several terms are used throughout this specification to describe the salient features of the invention in conjunction with the accompanying drawings. These terms, which may include "first," "second," "inner," "outer," etc., are not intended to unduly limit the scope of the invention unless otherwise noted. As used herein, the terms "about" or "approximately" may refer to a range of 80% to 125% of the claimed or disclosed value. With respect to the drawings, their purpose is to depict the salient features of the method for additively manufacturing a transparent polyamide lens for a lamp and are not to be provided to scale.

[0022] Figure 1 FIG2 shows a schematic illustration of an apparatus for fused filament fabrication, or fused deposition modeling (FDM). A filamentary material 20 is fed into an FDM printer 10, where it is heated, melted, and extruded through one or more nozzles 40 positioned on an extrusion head 30. The melted filamentary material, or "printing material," 25 (or lens material), is then deposited in layers 27 according to a predetermined template to form a three-dimensional lens 90. The predetermined template, or operating instructions, are preloaded into the controller 200 of the FDM printer 10 and specify the printing parameters of the printed lens 90, such as shape, thickness, and composition. To switch production to lenses of different shapes and / or sizes, a new set of instructions is input into the controller 200, and one or more nozzles 40 may be changed. This means there is a relatively short interruption in production before lenses of different shapes can be manufactured, and the design freedom of the lenses is increased. In contrast, when using a molding process, changing production to a lens of a different shape requires complete retooling and / or the creation of a new mold. This significantly increases lag time and costs, which in turn reduces design freedom.

[0023] In the described embodiment, the lens is composed of a transparent polyamide material that is impact resistant, has a high glass transition temperature, and also has high light transmittance compared to the acrylic materials traditionally used for mold lenses. Examples of such materials are nylon and aliphatic amorphous polyamide (ISO 1874 nomenclature PA PACM12). Table 1 below compares certain properties of aliphatic amorphous polyamide (AAP) with certain properties of typical acrylic materials.

[0024] Table 1

[0025]

[0026] FDM printing of transparent polyamide lenses also offers several benefits compared to stereolithography, such as reduced or no product degradation due to UV exposure and increased resistance to a wide range of chemicals. All of these properties of FDM-printed transparent polyamide lenses are particularly desirable for producing lens-based luminaires for use in environments classified as hazardous.

[0027] refer to Figure 1 , the layer 27 of the printing material 25 can be deposited directly onto the working surface 70 or onto the support material 60, or any combination of the two. The support material 60 can be used during the printing process to support the printing material 25 while the layer 27 is built up to form the three-dimensional lens 90. The extrusion head 30 is configured to move along the extrusion head axis X in order to print the lens 90. As shown, the lens 90 is a concave lens, however, lenses of nearly any shape, size, and configuration can be formed using this printing process.

[0028] like Figures 2a to 2c As shown, lens 90 is depicted at various stages of the printing process. Figure 2a An early point in the printing process is shown depicting the deposition of a layer of material (indicated using horizontal lines) 27 that forms a portion of lens 90 , with support material 60 positioned to support printed material 25 as the layers are built up to form lens 90 . Figure 2b The time point in the printing process is depicted where approximately 50% of the lens 90 is printed and Figure 2c A complete or nearly complete lens 90 is depicted. As can be seen, the extrusion head 30 and nozzle 40 move along the guide 12 and along the extrusion head axis X. Return to Reference Figure 1 , it can be seen that the guide 12 is capable of moving the extrusion head 30 and the nozzle 40 along the axes Y and Z. Figure 3aAs shown schematically, the printed material 25 is deposited in successive layers 27 and is built up along axis Y according to a predetermined template or operating instructions. In some embodiments, the ends of the layers 27 can be rounded or otherwise include a radius 28 defining a depression or notch 29 between each layer 27. As the lens material 25 is built up along the Y axis, it can also be built up along the Z axis, as shown. Figure 3b shown. Figure 3b There is shown a top schematic diagram depicting the guide 12 moving along the Z axis and enabling the lens material 25 to be deposited through the nozzle by the extrusion head 30. In this manner a three-dimensional lens 90 is manufactured.

[0029] Once the lens 90 is printed, it may then undergo one or more post-printing or finishing steps to meet the final lens specifications. Post-printing steps may include, but are not limited to, solvent cleaning, polishing, etching, sanding, grinding, or stamping. In some embodiments, the printed material 25 may be composed of one or more colors or even more than one material. The printed material may further include fillers or other additives to control the softness of the transmitted light.

[0030] Printing lens 90 using FDM enables the production of lenses 90 with specific transmission scattering properties on conventional non-printed acrylic lenses. The optical properties of printed lens 90 can be altered by adjusting variables of the printing process (rather than changing the type of printing material), such as nozzle diameter and raster angle. Transmission scattering is the physical observation that light scatters from the surface of an object. Figure 4 Transmission scattering at locations on a non-printed acrylic lens is plotted. The locations of the measurements on the lens are indicated along the X and Y axes. The center of the transmission area shows approximately 15% to 20% transmission with minimal light scattering. Conversely, Figure 5a to Figure 5b The transmitted scatter of an embodiment of a lens 90 manufactured using FDM is shown in . As previously mentioned, FDM printed lenses can be configured to exhibit different levels of transmitted scatter. Figure 5a An embodiment of a lens having a smooth surface is shown, and exhibits +45° transmission scattering at the measured position. Figure 5b Includes a rough surface and exhibits -45° transmission scattering at the measured location. Similar to Figure 4 , indicating the measured position on the lens on the X and Y axes, and the light transmittance range is from about 0% to 20% transmission. The light transmission scattering can be further controlled by various printing parameters to obtain Figure 5c For example, total transmission can be a function of direct transmission, where no lens is used, or diffuse transmission, where a lens is used to affect light transmission scattering.

[0031] Now refer to Figures 6 to 7c Discuss the effect of light transmission. Figure 6 Reference mark 110 is shown as seen by the naked eye. Figure 7a The transparent nylon, FDM printed lens 90a is shown placed below Figure 6 Reference mark 110. Lens 90a was printed with a 0.4 mm nozzle oriented at a raster angle of 0° relative to the working surface 70. As can be seen, this combination produces a Figure 6 A slightly grainy image of reference marker 110. Figure 7b The lens 90b uses Figure 7a , but the same raster angle. As can be seen, this combination results in a more striped image of reference label 110 when viewing lens 90b. Finally, Figure 7c Illustration use and Figure 7b The same nozzle but with +45° and -45° raster angles for transparent nylon, FDM printed lens 90c. Figure 7c 90c. Thus, each of these lenses 90a, 90b, 90c exhibits a different light transmission scattering pattern as experienced when viewing the label 110 through them. This illustrates the multiple variations that can be quickly used to print a variety of different lenses 90 having different optical properties.

[0032] Additional embodiments include any one of the embodiments described above and in any and all presentations and other materials submitted herein, wherein one or more features, functions, or structures of that embodiment may be interchanged with, replaced by, or augmented by one or more features, functions, or structures of a different embodiment described above.

[0033] It should be understood that various changes and modifications to the embodiments described herein will be apparent to those skilled in the art. Such changes and modifications may be made without departing from the spirit and scope of the present disclosure and without diminishing the intended advantages of the present disclosure. Therefore, it is intended that such changes and modifications be covered by the appended claims.

[0034] Although several embodiments of the present disclosure have been disclosed in the foregoing description, it will be appreciated by those skilled in the art that many modifications and other embodiments related to the present disclosure may be conceived and that, having the benefit of the teachings presented in the foregoing description and the associated drawings, many modifications and other embodiments are contemplated. Therefore, it will be understood that the present disclosure is not limited to the specific embodiments disclosed above and that many modifications and other embodiments are intended to be included within the scope of the appended claims. Furthermore, although specific terms are used herein and in the claims that follow, they are used in a generic and descriptive sense only and not for purposes of limitation.

Claims

1. A method for manufacturing a three-dimensional lens for a lamp using an additive manufacturing process, the method comprising: Inputting the lens template into the controller of the printing press; A first filamentous layer of transparent polyamide material is deposited onto the working surface according to the lens template. On the surface; as well as successively depositing further filamentary layers of the transparent polyamide material onto the first filamentary layer according to the lens template to build up the three-dimensional lens, wherein the lens template includes a transmission scattering profile for transmitting light; The lens template specifies the nozzle diameter and raster angle of the printer to achieve a transmission scattering profile for the transmitted light.

2. The method according to claim 1, further comprising at least one post-printing process. 3 . The method according to claim 1 , wherein one or more fillers are added to the transparent polyamide material in order to control the softness of the transmitted light.

4. The method of claim 3, wherein the transparent polyamide material is tinted with a color. The method of claim 1 , wherein the three-dimensional lens comprises one or more smooth surfaces.

6. The method of claim 1, wherein at least a portion of the three-dimensional lens is built upon a support material, and wherein the support material is removed after the depositing is complete.

7. The method of claim 1, wherein the first filamentary layer and the additional filamentary layer are substantially parallel to each other.

8. A method for manufacturing a three-dimensional lens, the method comprising: Inputting the lens template into the controller of the printing press; depositing a first layer of lens material onto a working surface according to the lens template; as well as successively depositing further layers of the lens material onto the first layer according to the lens template to build up the three-dimensional lens, wherein the transmission scattering profile of the transmitted light is a portion of the lens template; The lens template specifies the nozzle diameter and raster angle to achieve a transmission scattering profile for the transmitted light.

9. The method of claim 8, wherein the lens is used in a light fixture.

10. The method of claim 8, wherein the lens material is a transparent polyamide material.

11. The method of claim 8, further comprising at least one post-printing process.

12. The method of claim 10, wherein one or more fillers are added to the transparent polyamide material in order to control the softness of the transmitted light.

13. The method of claim 12, wherein the transparent polyamide material is tinted a color.

14. The method of claim 8, wherein at least a portion of the three-dimensional lens is built upon a support material, and wherein the support material is removed after the deposition of the lens material is completed.

15. The method of claim 8, wherein the first layer and the additional layer are substantially parallel to each other.

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