Patent Application
20240418346
This application claims priority under 35 U.S.C. §§ 119 and 365 to German Application Nos. DE 102021103648.8, filed Feb. 16, 2021 and DE 102021001844.3, filed Apr. 9, 2021, the contents of each of which are incorporated by reference in its entirety.
The present invention relates to lighting devices which can be used for illuminating purposes. An example of such lighting device is a softbox having a funnel-shaped reflector. The softbox can be used for illumination in film locations, for example. The invention further relates to a method of manufacture of such lighting device.
A conventional softbox known from WO 2013/098678 A1 has a funnel-shaped reflector having side walls made of fabric spanned by a plurality of rods.
It has been found that the conventional softbox is complicated to manufacture and assemble.
It is an object of the present invention to provide an improved lighting device having a funnel-shaped reflector.
Embodiments of the invention provide a lighting device comprising a self-supporting funnel-shaped reflector having a proximal edge and a distal edge, wherein a circumferential length of the funnel-shaped reflector at the proximal edge is smaller than a circumferential length of the funnel-shaped reflector at the distal edge, and wherein the reflector has a reflective inner surface.
According to embodiments, the reflector is made of at least a first piece of a flat material having a first edge and a second piece of the flat material having a second edge, wherein the first edge of the first piece is attached to the second edge of the second piece, wherein the first edge of the first piece and the second edge of the second piece extend around the central axis, wherein the first and second pieces of the flat material, when resting on a flat surface before being attached to each other, have the following properties: a first circle approximating the first edge of the first piece has a first radius, a second circle approximating the second edge of the second piece has a second radius, and the first radius is smaller than the second radius. The flat material provides the wall material of the reflector, and the first and second pieces, formed of the flat material provide the reflector.
With such configuration, the reflector may have a simple configuration and provide a dome-shaped reflecting surface having advantageous light shaping properties.
According to embodiments, the first radius is smaller than 0.9 times the second radius.
According to embodiments, the first piece is located closer to the proximal end than the second piece. Herein, the first piece of material may have a third edge opposite to the first edge, and the third edge of the first piece may provide the proximal edge of the reflector.
According to embodiments, the second piece of material has a fourth edge opposite to the second edge, and wherein the fourth edge of the second piece provides the distal edge of the reflector.
According to embodiments, the first edge of the first piece is attached to the second edge of the second piece by sewing, gluing, and/or an adhesive.
According to embodiments, the first piece of material has, when resting on the flat surface before being attached to each other, a fifth edge connecting the first and third edges, and a sixth edge opposite the fifth edge and connecting the first and third edges, and wherein the fifth edge is attached to the sixth edge when the reflector is formed. Herein, the fifth edge can be releasably attached to the sixth edge, and the fifth edge can be attached to the sixth edge by a hook-and-loop-fastener.
According to embodiments, the funnel-shaped reflector is formed of a wall material having a flexural rigidity greater than 1.0×10−3 N·mm and less than 1.0×103 N·mm.
According to embodiments, the funnel-shaped reflector is free of supporting structures extending between the proximal edge and the distal edge. Such supporting structures may include, for example, elements, such as flexible rods. According to particular embodiments herein, the funnel-shaped reflector is free of supporting structures extending between the proximal edge and the distal edge and providing a flexural rigidity greater than the flexural rigidity provided by the wall material itself.
More specifically, the funnel-shaped reflector may have a shape of a dome or a pyramid, for example.
The flexural rigidity of a material can be measured by a 3-point method according to DIN 53121:2014-08. In such measurement, a square shaped sample of the wall material having a length l and a width b in the direction of the bending axis is supported at its both ends and a force F is applied to the center of the length, resulting in a maximal deflection f. The flexural rigidity S can be calculated according to the following formula:
Further, the flexural rigidity of a material can be measured by a 2-point method according to DIN 53121:2014-08. In such measurement, a cantilever shaped sample of the wall material having a length l and a width b in the direction of the bending axis is fixed at one end. The other end is free from support. A force F is applied on the free end in the direction perpendicular to the length l, thus resulting in a maximal deflection f. The flexural rigidity S can be calculated according to the following formula:
According to particular embodiments, the flexural rigidity of the wall material is greater than or equal to 1.0×10−3 N·mm and less than 5.0×10−3 N·mm, or greater than or equal to 5.0×10−3 N·mm and less than 1.0×10−2 N·mm, or greater than or equal to 1.0×10−2 N·mm and less than 5.0×10−2 N·mm, or greater than or equal to 5.0×10−2 N·mm and less than 0.1 N·mm, or greater than or equal to 0.1 N·mm and less than 0.5 N·mm, or greater than or equal to 0.5 N·mm and less than 1.0 N·mm, or greater than or equal to 1.0 N·mm and less than 5.0 N·mm, or greater than or equal to 5.0 N·mm and less than 10.0 N·mm, or greater than or equal to 10.0 N·mm and less than 50.0 N·mm, or greater than or equal to 50.0 N·mm and less than 1.0×102 N·mm, or greater than or equal to 1.0×102 N·mm and less than 5.0×102 N·mm, or greater than or equal to 5.0×102 N·mm and less than 1.0×103 N·mm.
A conventional softbox is formed by conveying cloth made of polyester. Such cloth is light-weighted and soft, so that it cannot bear any applied bending moment by itself. Accordingly, rod-like structures are typically indispensable to support the spanning volume of a softbox. Further, since rod-like structures are used to support the spanning volume of a softbox, the reflector is usually made of soft wall material which has a low flexural rigidity.
The inventor has found that the conventional softbox can be simplified by avoiding the rod-like structures. To this end, a stiffer wall material is provided to form a self-supporting reflector. By means of a stiffer wall material, the supporting function of rod-like structures can be fulfilled by the wall material. Such higher stiffness is achieved by a wall material having the flexural rigidity illustrated above.
Moreover, the inventor has found that a reflector having the dome-shaped three dimensional convex curved shape can be readily formed from two or more pieces of flat material having edges of different radii attached to each other.
The lighting device which is free of supporting structures extending between the proximal edge and the distal edge may be formed simply by a simple funnel-shaped self-supporting reflector. Such structure is not only simple and economical to manufacture, but is also robust and durable, since there is no necessity for interconnection between different structural elements, such as seams required to provide channels for the insertion of flexible rods in the conventional softbox.
According to some embodiments, the light reflective surface has an average spectral reflectance higher than 0.5 in a wavelength range between 450 nm and 650 nm. This may improve the quality of the light diffused from the collapsible lighting device during use. The reflectance can be measured by dividing an intensity of a light beam reflected off the reflecting surface by the measured light intensity of the incident beam hitting the reflecting surface, wherein the incident beam hits nearly orthogonally the surface.
According to some embodiments, the wall material has a light absorbing surface providing an outer surface of the reflector, wherein the light absorbing surface has an absorbance greater than 0.5, in particular greater than 0.7, and in particular greater than 0.8. The absorbance can be measured by dividing an intensity of an incident light beam hitting the absorbing surface by the intensity of all incident light reflected or scattered from that surface. Such absorbing outer surface may help suppress undesired light.
According to some embodiments, a distance between the proximal edge and the distal edge of the reflector is smaller than 1.5 m and greater than or equal to 0.05 m, or smaller than 1.2 m and greater than or equal to 0.06 m, or smaller than 1.0 m and greater than or equal to 0.07 m, or smaller than 0.8 m and greater than or equal to 0.08 m, or smaller than 0.6 m and greater than or equal to 0.09 m, or smaller than 0.5 m and greater than or equal to 0.1 m, or smaller than 0.4 m and greater than or equal to 0.11 m, or smaller than 0.3 m and greater than or equal to 0.12 m, or smaller than 0.1 m and greater than or equal to 0.05 m, or smaller than 0.2 m and greater than or equal to 0.1 m, or smaller than 0.3 m and greater than or equal to 0.2 m, or smaller than 0.4 m and greater than or equal to 0.3 m, or smaller than 0.5 m and greater than or equal to 0.4 m, or smaller than 0.6 m and greater than or equal to 0.5 m, or smaller than 0.7 m and greater than or equal to 0.6 m, or smaller than 0.8 m and greater than or equal to 0.7 m, or smaller than 0.9 m and greater than or equal to 0.8 m, or smaller than 1.0 m and greater than or equal to 0.9 m, or smaller than 1.1 m and greater than or equal to 1.0 m, or smaller than 1.2 m and greater than or equal to 1.1 m, or smaller than 1.3 m and greater than or equal to 1.2 m, or smaller than 1.4 m and greater than or equal to 1.3 m, or smaller than 1.5 m and greater than or equal to 1.4 m. Such distances between the proximal edge and the distal edge of the reflector can meet the demand of various sizes of a collapsible lighting device.
According to some embodiments, the distance between the proximal edge and the distal edge of the reflector is smaller than 0.5 m and greater than or equal to 0.05 m, and the flexural rigidity of the wall material is greater than or equal to 1.0×10−3 N·mm and less than 5.0×10−3 N·mm, or greater than or equal to 5.0×10−3 N·mm and less than 1.0×10−2 N·mm, or greater than or equal to 1.0×10−2 N·mm and less than 5.0×10−2 N·mm, or greater than or equal to 5.0×10−2 N·mm and less than 0.1 N·mm, or greater than 0.1 N·mm or equal to and less than 0.5 N·mm, or greater than or equal to 0.5 N·mm and less than 1.0 N·mm, or greater than or equal to 1.0 N·mm and less than 5.0 N·mm, or greater than or equal to 5.0 N·mm and less than 10.0 N·mm, or greater than or equal to 10.0 N·mm and less than 50.0 N·mm, or greater than or equal to 50.0 N·mm and less than 1.0×102 N·mm, or greater than or equal to 1.0×102 N·mm and less than 5.0×102 N·mm, or greater than or equal to 5.0×102 N·mm and less than 1.0×103 N·mm. According to some embodiments, the distance between the proximal edge and the distal edge of the reflector is smaller than 0.8 m and greater than or equal to 0.4 m, and the flexural rigidity of the wall material is greater than or equal to 1.0×10−3 N·mm and less than 5.0×10−3 N·mm, or greater than or equal to 5.0×10−3 N·mm and less than 1.0×10−2N·mm, or greater than or equal to 1.0×10−2 N·mm and less than 5.0×10−2 N·mm, or greater than or equal to 5.0×10−2 N·mm and less than 0.1 N·mm, or greater than 0.1 N·mm or equal to and less than 0.5 N·mm, or greater than or equal to 0.5 N·mm and less than 1.0 N·mm, or greater than or equal to 1.0 N·mm and less than 5.0 N·mm, or greater than or equal to 5.0 N·mm and less than 10.0 N·mm, or greater than or equal to 10.0 N·mm and less than 50.0 N·mm, or greater than or equal to 50.0 N·mm and less than 1.0×102 N·mm, or greater than or equal to 1.0×102 N·mm and less than 5.0×102 N·mm, or greater than or equal to 5.0×102 N·mm and less than 1.0×103 N·mm. According to some embodiments, the distance between the proximal edge and the distal edge of the reflector is smaller than 1.2 m and greater than or equal to 0.7 m, and the flexural rigidity of the wall material is greater than or equal to 1.0×10−3 N·mm and less than 5.0×10−3 N·mm, or greater than or equal to 5.0×10−3 N·mm and less than 1.0×10−2 N·mm, or greater than or equal to 1.0×10−2 N·mm and less than 5.0×10−2 N·mm, or greater than or equal to 5.0×10−2 N·mm and less than 0.1 N·mm, or greater than 0.1 N·mm or equal to and less than 0.5 N·mm, or greater than or equal to 0.5 N·mm and less than 1.0 N·mm, or greater than or equal to 1.0 N·mm and less than 5.0 N·mm, or greater than or equal to 5.0 N·mm and less than 10.0 N·mm, or greater than or equal to 10.0 N·mm and less than 50.0 N·mm, or greater than or equal to 50.0 N·mm and less than 1.0×102 N·mm, or greater than or equal to 1.0×102 N·mm and less than 5.0×102 N·mm, or greater than or equal to 5.0×102 N·mm and less than 1.0×103 N·mm. According to some embodiments, the distance between the proximal edge and the distal edge of the reflector is smaller than 1.5 m and greater than or equal to 1.1 m, and the flexural rigidity of the wall material is greater than or equal to 1.0×10−3 N·mm and less than 5.0×10−3 N·mm, or greater than or equal to 5.0×10−3 N·mm and less than 1.0×10−2 N·mm, or greater than or equal to 1.0×10−2 N·mm and less than 5.0×10−2 N·mm, or greater than or equal to 5.0×10−2 N·mm and less than 0.1 N·mm, or greater than 0.1 N·mm or equal to and less than 0.5 N·mm, or greater than or equal to 0.5 N·mm and less than 1.0 N·mm, or greater than or equal to 1.0 N·mm and less than 5.0 N·mm, or greater than or equal to 5.0 N·mm and less than 10.0 N·mm, or greater than or equal to 10.0 N·mm and less than 50.0 N·mm, or greater than or equal to 50.0 N·mm and less than 1.0×102 N·mm, or greater than or equal to 1.0×102 N·mm and less than 5.0×102 N·mm, or greater than or equal to 5.0×102 N·mm and less than 1.0×103 N·mm.
According to some embodiments, the funnel-shaped reflector is formed of one contiguous piece of the wall material, and a first pair of opposite ends of the contiguous piece of the wall material is connected by a seam and/or adhesive. When these opposite ends of the wall material are connected, the self-supporting structure of the reflector is formed, and no other connections between the wall material and other elements are required to form the self-supporting funnel-shaped reflector. Herein, a second pair of opposite ends of the contiguous piece of the wall material may provide the proximal edge and the distal edge, respectively.
According to some embodiments, the wall material of the funnel-shaped reflector is a thermoplastic material, wherein the wall material is a contiguous web extending around the funnel-shaped reflector. By means of a thermoplastic deformation of the wall material, it is convenient to form at least one corner line extending between the proximal edge and the distal edge. Such a manufacturing process for the corner lines can be more economical than the manufacture of conventional rod-like structures.
The thermoplastic material can be a plastic polymer material that becomes pliable or moldable at a certain elevated temperature and solidifies upon cooling. The thermoplastic material may include materials such as acrylonitrile butadiene styrene (ABS), polylactic acid (polylactide), poly(methyl methacrylate) (PMMA), polycarbonate (PC), polyethylene terephthalate (PET), polyethylene (PE), polypropylen (PP), polystyrol (PS), polyetheretherketon (PEEK), polyvinyl chloride (PVC).
According to particular embodiments, the wall material of the funnel-shaped reflector is formed of a reflective film sandwiched to a polyester fabric layer.
According to some embodiments, the collapsible lighting device comprises a diffuser fixed to the distal edge of the funnel-shaped reflector. The connection part of the distal edge of the funnel-shaped reflector and the diffuser may be formed by a hook-and-loop fastener, wherein the diffuser comprises plural tiny hooks and the distal edge comprises plural tiny loops, for example.
According to embodiments, a method of manufacturing a lighting device as illustrated above comprises providing a contiguous piece of thermoplastic material, forming corner lines in the thermoplastic material by heating the piece of thermoplastic material along plural spaced apart straight lines and folding the material at the straight lines, and connecting opposite edges of the contiguous piece of thermoplastic material to form a funnel shaped reflector.
The thermoplastic material provides the wall material of the reflector, and can be of the type and may have a rigidity as illustrated above.
In particular, the providing of the contiguous piece of thermoplastic material may comprise providing a first surface of the thermoplastic material with a reflective surface, wherein the reflective surface provides an inner surface of the funnel shaped reflector.
The heating the piece of thermoplastic material along plural spaced apart straight lines can be performed using an edge of a metal block heated to a temperature higher than softening temperature of the thermoplastic material. The thermoplastic material is brought into contact with the heated edge using a suitable tool, such as a rubber roller. The material is heated by the heated edge along a straight line due to the thermal contact between the edge and the material, and the elastic roller deforms the thermoplastic material along the edge such that the material is partially folded around the edge. Thereafter, the material is removed from the metal block, the temperature of the thermoplastic material drops below its softening temperature, and the shape of the fold is maintained in the material, forming a corner line of the material. This corner line will provide a corner of the final reflector.
The forgoing as well as other advantageous features of the disclosure will be more apparent from the following detailed description of exemplary embodiments with reference to the accompanying drawings. It is noted that not all possible embodiments necessarily exhibit each and every, or any, of the advantages identified herein. Herein:
A loop portion 11 of a hook-and-loop fastener 9 is provided at the distal edge 7. A corresponding hook portion 13 of the hook-and-loop fastener 9 is provided at an outer periphery of a diffuser 15 shown in
The reflector 3 has four corner lines 17 extending between the proximal edge 5 and the distal edge 7. Accordingly, the corner lines 17 and proximal edge 5 and a distal edge 7 define four wall surfaces 19.
The piece 27 of wall material 29 includes four trapezoid regions 31, wherein each trapezoid region 31 will provide one of the four wall surfaces 19 in the finished funnel-shaped reflector 3. The four trapezoid regions 31 are separated by three lines 33. Each of the three lines 33 will coincide with one corner line 17 in the finished funnel-shaped reflector 3. In the process of manufacture of the funnel-shaped reflector 3, two opposite ends 35 of the piece 27 of wall material 29 are connected by suitable means, such as a seam 37 or adhesive. The line of contact between these opposite ends 35 will coincide with the fourth corner line 17 in the finished funnel-shaped reflector 3. Alternatively, the opposite ends 35 of the piece 27 of the wall material 29 can be connected by other means, such as an adhesive or a releasable hook-and-loop fastener.
In the process of manufacture of the funnel-shaped reflector 3, the three corner lines 17 of the reflector 3 not coinciding with the seam 37 or adhesive are formed by thermoplastic deformation of the wall material 29 along the lines 33.
Specifically, the corner lines 17 can be formed by heating the wall material 29 along the plural spaced apart straight lines 33 using an edge of a metal block heated to a temperature higher than softening temperature of the thermoplastic wall material 29. The thermoplastic material is brought into contact with the heated edge using a suitable tool, such as a rubber roller. The wall material 29 is heated by the heated edge along a straight line 33 due to the thermal contact between the edge and the material, and the rubber roller deforms the thermoplastic wall material 29 along the edge such that the material is partially folded around the edge. Thereafter, the wall material 29 is removed from the metal block, the temperature of the thermoplastic wall material 29 drops below its softening temperature, and the shape of the fold is maintained in the wall material 29, forming a corner line 17 of the wall material 29. This corner line 17 will provide a corner 17 of the final reflector 3.
In other examples, the reflector can be manufactured from two or more pieces of wall material, wherein each piece provides at least one corner line, and wherein two adjacent pieces of the wall material can be attached to each other by a seam line or adhesive.
This wall material can be deformed by plastic deformation. For example, the piece of wall material can be pressed against a hot iron body having a linear edge for a suitable time in order to form the corners at the corner lines 17.
The structure of the funnel-shaped reflector 3 shown in
In the examples illustrated above, the funnel-shaped reflector 3 has four corner lines 17. It is, however, possible to provide a funnel-shaped reflector having a lower or higher number of corner lines, such as three, five, six or twelve corner lines. Moreover, it is also possible to provide a funnel-shaped reflector having a circular cross section without any corner lines as will be described in more detail below. The manufacture of such reflector does not require the formation of corner lines by methods involving steps such as thermoplastic deformation. Only the two opposite ends 35 of the piece 27 of wall material 29 need to be connected in order to form a round funnel-shaped reflector of the collapsible lighting device.
The lighting device 1a shown in
The wall material 29a may have the same or similar material as that illustrated the embodiment of
Two opposite ends of the one contiguous piece of wall material 29a are shown as 51 and 53 respectively in
In
The first piece 61 of the wall material 29b has a third edge 65 opposite to the first edge 63 thereof. The third edge 65 forms the proximal edge 5b of the reflector 3b.
The second piece 71 of wall material 29b has a fourth edge 75 opposite to the second edge 73. The fourth edge 75 forms the distal edge 7b of the reflector 3b.
The first piece 61 of wall material 29b of the reflector 3b is located closer to the proximal edge 5b than the second piece 71 of the wall material 29b thereof.
As shown in
Likewise, a seventh edge 77 of the second piece 71 of the wall material 29b connects the second 73 and the fourth edges 75. An eighth edge 79 is located opposite the seventh edge 77 and connects the second 73 and the fourth edges 75.
In
As shown in
In
As shown in
Likewise, a seventh edge 77c of the second piece 71c of wall material 29c connects the second 73c and the fourth edges 75c. An eighth edge 79c is located opposite the seventh edge 77c and connects the second 73c and the fourth edges 75c.
In other examples, the reflector can be manufactured from three or more pieces of wall material, wherein two adjacent pieces of the wall material can be attached to each other by sewing, gluing and/or adhesive.
While the disclosure has been described with respect to certain exemplary embodiments thereof, it is evident that many alternatives, modifications and variations will be apparent to those skilled in the art. Accordingly, the exemplary embodiments of the disclosure set forth herein are intended to be illustrative and not limiting in any way. Various changes may be made without departing from the spirit and scope of the present disclosure as defined in the following claims.
| Number | Date | Country | Kind |
|---|---|---|---|
| 102021103648.8 | Feb 2021 | DE | national |
| 102021001844.3 | Apr 2021 | DE | national |
| Number | Date | Country | |
|---|---|---|---|
| Parent | 17671377 | Feb 2022 | US |
| Child | 18821008 | US |
