Lighting device with foldable housing

Abstract

A method for manufacturing a lighting device (100), the method comprising the steps of providing (S1) a sheet of optically transmissive plastic material, forming (S2) a lighting device housing from the sheet of optically transmissive plastic material, such that the lighting device housing comprises a first portion (212) connected to a second portion (214) by a flexible connecting portion (202), folding (S3) the first (212) or second portion (214) about the flexible connecting portion (202) to enclose a light source (210) and driver electronics (206) within an enclosed region of the lighting device housing, and securing (S4) the first portion (212) to the second portion (214) such that the lighting device housing maintains the folded position.

Claims

1. A lighting device comprising: a lighting device housing formed of an optically transmissive material and including an assembly aid portion, a light source arranged within said lighting device housing and mounted to a surface of the assembly aid portion, driver electronics configured to drive said light source, arranged within said lighting device housing in a compartment formed by the assembly aid portion opposite from the surface and the light source, wherein said lighting device housing comprises: a first housing portion and a second housing portion connected to each other by a flexible connecting portion, said first housing portion being configured to be folded about said flexible connecting portion to enclose said light source and said driver electronics within said lighting device housing, and; means for securing said first housing portion to said second housing portion to maintain said lighting device housing in a folded position, wherein said lighting device housing is formed in one piece and the assembly aid portion is formed as a wall extending transversely with respect to a socket portion of the housing across the first housing portion.

2. A lighting device according to claim 1, wherein said optically transmissive material is a thermo formable plastic.

3. A lighting device according to claim 1, wherein said optically transmissive material is transparent.

4. A lighting device according to claim 1, further comprising a heat spreader arranged within the lighting device housing and configured to conduct heat from said light source and/or driver electronics to said lighting device housing.

5. A lighting device according to claim 4, wherein said heat spreader-comprises a heat conducting foil and/or a preformed heat conductive element.

6. A lighting device according to claim 1, wherein said means for securing comprises an ultrasonic weld, a thermal weld, a snap fitting, and/or deformation fitting.

7. A lighting device according to claim 1, wherein said lighting device housing comprises diffusing elements configured to scatter light propagating through said lighting device housing.

8. A lighting device according to claim 1, wherein said lighting device housing comprises wavelength converting material.

9. A lighting device according to claim 7, wherein said diffusing elements are comprised in: a pattern printed on said transparent plastic material, a film laminated on said transparent plastic material and/or a material co-extruded with said transparent plastic material.

10. A lighting device according to claim 1, wherein said lighting device housing further comprises a removable hanger portion.

11. A lighting device according to claim 1, further comprising a base portion attached to an outside of said lighting device housing, and electrically connected to said driver electronics and configured to connect said lighting device to a power source.

12. A method for manufacturing a lighting device, said method comprising the steps of: providing a sheet of optically transmissive plastic material, forming a lighting device housing from said sheet of optically transmissive plastic material, such that said lighting device housing comprises a first portion connected to a second portion by a flexible connecting portion and an assembly aid portion within at least one of the first and second portions, mounting a light source to a surface of the assembly aid portion, the assembly aid portion formed as a wall extending transversely with respect to a socket portion of the housing across the first portion; positioning driver electronics in a compartment formed by the assembly aid portion opposite the surface and the light source, folding said first or second portion about said flexible connecting portion to enclose the light source and the driver electronics within an enclosed region of said lighting device housing, and securing said first portion to said second portion such that said lighting device housing maintains said folded position.

13. A method for manufacturing a lighting device according to claim 12, further comprising at least one of the steps of: preprinting said optically transmissive plastic material, laminating said optically transmissive plastic material, and co-extruding said optically transmissive plastic material.

14. A lighting device according to claim 8, wherein said wavelength converting material is comprised in: a pattern printed on said transparent plastic material, a film laminated on said transparent plastic material and/or a material co-extruded with said transparent plastic material.

15. The method of claim 12, wherein the positioning includes positioning the driver electronics solely in the compartment and the method does not include positioning any driver electronics in the second portion.

16. The lighting device of claim 1, wherein the first housing portion includes the assembly aid portion to form the compartment in the first housing portion, the driver electronics are positioned wholly in the compartment, and the second housing portion does not include any driver electronics.

17. The lighting device of claim 1, wherein the light source is wholly included in the first housing portion and the second housing portion does not include any light sources.

18. A lighting device comprising: a lighting device housing formed of an optically transmissive material and including an assembly aid portion, a light source arranged within said lighting device housing and mounted to the assembly aid portion, driver electronics configured to drive said light source, arranged within said lighting device housing in a compartment formed by the assembly aid portion opposite from the light source, wherein said lighting device housing comprises: a first housing portion and a second housing portion connected to each other by a flexible connecting portion, said first housing portion being configured to be folded about said flexible connecting portion to enclose said light source and said driver electronics within said lighting device housing, and; means for securing said first housing portion to said second housing portion to maintain said lighting device housing in a folded position, wherein said lighting device housing is formed in one piece, the first housing portion includes the assembly aid portion to form the compartment in the first housing portion, the driver electronics are positioned wholly in the compartment, and the second housing portion does not include any driver electronics.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) This and other aspects of the present invention will now be described in more detail, with reference to the appended drawings showing an embodiment of the invention.

(2) FIG. 1 is a perspective view of a lighting device according to an embodiment of the invention;

(3) FIG. 2 is a schematic side view of a lighting device according to an embodiment of the invention;

(4) FIG. 3 is a schematic side view of a lighting device according to an embodiment of the invention;

(5) FIG. 4 is a cross-section of a lighting device according to an embodiment of the invention;

(6) FIG. 5 is a flow chart for a method of manufacturing a lighting device according to an embodiment of the invention;

(7) FIG. 6 is a cross-section of a lighting device according to an embodiment of the invention; and

(8) FIG. 7 is a perspective view of a lighting device according to another embodiment of the invention.

DETAILED DESCRIPTION OF EXAMPLE EMBODIMENTS OF THE INVENTION

(9) In the present detailed description, various embodiments of a lighting device according to the present invention are mainly discussed with reference to a lighting device comprising light emitting diodes (LEDs) as a light source. It should be noted that this by no means limits the scope of the invention, which is also applicable in other circumstances, for example for use with other types of light sources. Moreover the number of LEDs shown in the enclosed drawings is only a schematic representation. In use, the arrangement, number of LEDs and other such details will be decided by each application.

(10) FIG. 1 is a perspective view of a lighting device 100 according to the present invention, therein embodied in the shape of a light bulb. The lighting device 100 comprises a bulb portion 102 and a socket portion 104, the socket portion 104 further comprises a base portion 108 by which the lighting device 100 may be fitted to an ordinary lighting fixture, for example an E14 or E27 Edison screw base for light bulbs. The base portion 108 is connected to the driver electronics of the lighting device, and is thereby able to connect the lighting device 100 to a power source. The base portion 108 of FIG. 1 is shaped as a screw base, however any shape or configuration whereby the lighting device 100 may be connected to a power source is within the scope of the invention such as a bayonet fixing with one or several plugs. Further shown in FIG. 1 is also the means for securing 106 whereby the portions of the lighting device housing have been secured to each other to maintain the bulb in a closed position.

(11) Referring now to FIG. 2, the lighting device 100 will be explained in more detail, shown in FIG. 2 is a schematic side view of an unfolded lighting device 100 according to the present invention. The lighting device 100 comprises a lighting device housing which comprises a first 212 and a second housing portion 214, the housing portions are connected by a flexible connecting portion 202. The flexible connecting portion 202 is flexible by merit of the material of which it is made or could optionally comprise perforations (not shown) to further enable the folding about the flexible connecting portion 202. The lighting device housing is formed in an optically transmissive plastic material, which is preferably thermo formable. Examples of materials which can be used for this purpose and that are suitable for role-fed high volume thermo forming production machines are PC, PETG, PETA and/or PVC which typically have a thickness of 2 mm or less. In FIG. 2 the light source, in this case a printed circuit board 208 (PCB) with mounted light emitting diodes 210 (LEDs) is shown placed in the first housing portion 212, the LEDs 210 are placed such that they, in use, emit light within the bulb portion 102 of the lighting device. Furthermore, the driver electronics 206 are also arranged in the first housing portion 212. It should be noted that the PCB 208 with LEDs 210 as well as the driver electronics 206 could just as well be placed in the second housing portion 214. The first 212 and/or second housing portion 214 may also comprise assembly aid portions 204 for holding the driver electronics 204 and PCB 208 during assembly, reducing or removing the need for manipulation or securing by glue or other types of fixtures these components during assembly of the lighting device 100. The assembly aid portions 204 in FIG. 2 are embodied as walls, however any type of geometrical representation is possible and within the scope of the invention including assembly aid portions 204 which are shaped complimentary with respect to the PCB 208 and the driver electronics 206.

(12) FIG. 3 is a schematic side view of an unfolded lighting device 100 according to an embodiment of the present invention. Compared to FIG. 2 the means for securing 300 the first portion 212 and the second portion 214 are also shown, the means for securing 300 may comprise at least one of; an ultrasonic weld, a thermal weld, snap fitting or deformation fitting. The means for securing 300 will ensure that the lighting device housing is securely closed, further it is desirable that the means for securing should be usable in a mass production facility, thus the means for securing can comprise a ultrasonic weld or thermal weld which is applied after the second housing portion 214 has been folded as indicated by the arrow A1, or alternatively a snap fitting could be used where the action of closing the second housing portion 214 over the first housing portion 212 with sufficient force will securely hold the first and second housing portions together. Similarly to the snap fitting a deformation fitting will use force to deform the means for securing into holding the first housing portion 212 to the second housing portion 214. In FIG. 3 the lighting device 100 further comprises a heat spreader 302, therein embodied by a heat conducting foil. The heat conducting foil 302 will, in use, conduct heat from the PCB 208 and driver electronics 206, which are arranged after the heat conducting foil 302, to the lighting device housing. The lighting device housing will conduct heat through the optically transmissive material to the surrounding environment. The heat conducting foil 302 will reach its final shape when the lighting device housing is folded, about the flexible connecting portion 202, as indicated by the arrow A1 and secured with the means for securing 300. In the embodiment shown in FIG. 3 the heat spreader 302 is as noted, a heat conducting foil 302. However, it is also possible to use a preformed heat conducting element which is placed in the lighting device housing prior to the PCB 208 and driver electronics 206. Alternatively, the heat spreader 302 may comprise a graphite heat conducting film or coating which is applied to further increase the heat conduction from the heat spreader 302 to the lighting device housing.

(13) Referring now to FIG. 4, a cross-section of a lighting device according to the present invention where the lighting device housing further comprises a removable hanger portion 402 is shown. The removable hanger portion 402 comprises a hole 404, which in FIG. 4 has an elongated shape, however the shape of the hole 404 may be any shape which allows the lighting device 100 to be hanged and as such provide its own hanging function in e.g. a store. The removable hanger portion 402 is removable through bending or through perforations (not shown) so that a user of the lighting device may remove the removable hanger portion 402 with a small or minimal amount of force. In the embodiment shown in FIG. 4 the lighting device 100 further comprises a layer 400, which may comprise diffusing elements configured to scatter light passing through the lighting device housing. The LEDs 210 may be viewed as point sources of light, hence it is beneficial to scatter the light which propagates through the lighting device housing and is emitted from the lighting device 100 in order to make the spatial distribution of emitted light more uniform. Furthermore, the layer 400 may also comprise a luminescent material which wavelength converts the light, for example a material comprising phosphors or quantum dots. The luminescent material 400 will wavelength convert light which is emitted from the LEDs 210 in order to make the spectrum of light emitted from the lighting device 100 aesthetically pleasant or allow a certain distribution on wavelengths such as a warmer white appearance which is appropriate for general indoor lighting.

(14) In FIG. 5 a flow chart for manufacturing a lighting device according to an embodiment of the invention is shown. In step S1 a sheet of optically transmissive plastic material is provided. The optically transmissive material may be PC, PETG, PETA and/or PVC, with a typical thickness of 2 mm or less. The sheet of optically transmissive material may as an alternative be pre-printed, co-extruded or laminated to enable certain effects such as diffusion or wavelength conversion of light which propagates through the material.

(15) Then in step S2, a lighting device housing is formed from the sheet of optically transmissive plastic material, the lighting device housing comprises a first housing portion 212 and a second housing portion 214 which are connected by a flexible connecting portion 202. The lighting device housing is according to various embodiments formed using thermo forming, whereby the sheet of optically transmissive material is heated and a mold of is applied to form the sheet into the shape of the lighting device housing. The flexible connecting portion 202 may comprise perforations to increase the flexibility.

(16) In step S3 the first 212 or the second housing portion 214 is folded about the flexible connecting portion 202 in order to enclose a light source 210 and driver electronics 206. Prior to which the aforementioned heat spreader 302 can be arranged in the lighting device housing in order to conduct heat from the light source 210 and/or the driver electronics 206 to the lighting device housing.

(17) Then in step S4, the first housing portion 212 is secured to the second housing portion 214 by the means for securing 300 such that the lighting device housing maintains the folded position. The means for securing 300 can be any one of the aforementioned alternatives, wherein the snap and deformation fitting will require some amount of force when applied in order to lock the lighting device housing in the folded position, and the ultrasonic or thermal weld will require the tools during production to apply such an weld.

(18) Referring now to FIG. 6, a schematic representation of an embodiment of the present invention is shown. According to the embodiment shown in FIG. 6, the light source(s) 604 and the driver electronics 602 are both arranged on a circuit board 600. By arranging both the light source(s) 604 and driver electronics 602 on a circuit board 600, the number of steps during assembly of the lighting device will be even further reduced. The printed circuit board 600 (PCB) therein is shaped as a cross section of a light bulb and is vertically aligned in the lighting device 100. The first and second portions of the lighting device housing are still configured to be folded about the connection portion 612. Furthermore, the PCB 600 arranged in the first portion of the lighting device housing includes both the LEDs 604 and the driver electronics 602, thereby further reducing the number of steps required for assembling the lighting device. The LEDs 604 may be placed on one or both sides of the PCB 600. Accordingly the PCB 600 may be provided in either one piece and configured to be foldable, or a first PCB (not shown) comprising the LEDs for one side and the driver electronics, and a second PCB (not shown) comprising LEDs 604 are mounted on the backside of the first PCB, thereby providing an even light distribution in all directions. Furthermore, in the embodiment shown in FIG. 6, an area 608 of the bulb portion may be used for an efficient thermal conduction from the lighting device housing to the surrounding environment. The other area of the bulb portion comprises an optically transmissive portion 610 which is transparent, but may also diffuse or wavelength convert light as described in connection to the above mentioned embodiments.

(19) FIG. 7 is a perspective view of another embodiment of a lighting device according to the present invention. In FIG. 7, the lighting device housing 700 comprises a plurality of housing portions. The lighting device housing 700 may therefore be seen as a folding blister type of housing. In the embodiment shown in FIG. 7, the lighting device housing 700 comprises four housing portions, however, in principle, a smaller or greater number of housing portions is possible. The four housing portions 702, 706, 708, 710 are each connected to the adjacent housing portion by a flexible connection portion 704. The lighting device of FIG. 7 further comprises a light source 712, which after each housing portion has been folded about its connection portion, will be enclosed together with the driver electronics 714 in the lighting device housing 700. The lighting device also comprises a base portion 716 for connecting the driver electronics to a power source. The means for securing (not shown) will secure the adjacent housing portions 702 and 710 in the folded state of the lighting device housing 700 in order to maintain the folded state of the lighting device housing 700. It should be noted that the aforementioned features of certain types of means for securing, the means for diffusing and/or wavelength converting light may also advantageously be incorporated in the lighting device shown in FIG. 7.

(20) Additionally, variations to the disclosed embodiments can be understood and effected by the skilled person in practicing the claimed invention, from a study of the drawings, the disclosure, and the appended claims. For example, the innovative lighting device is embodied in the drawings as a light bulb, however in principle any form or shape of lighting device that may be contemplated is possible to form according to the invention such as e.g. a tube lighting device. Furthermore, the lighting device housing portions shown in the figures is folded along a vertical plane. However, this should only be interpreted as an example, the lighting device housing may be folded just as well in a horizontal plane or in principle in any direction. In the claims, the word comprising does not exclude other elements or steps, and the indefinite article a or an does not exclude a plurality. The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measures cannot be used to advantage.