Lighting device having wireless communication antenna

Abstract

To provide an improved or alternative lighting device having a wireless communication antenna.SOLUTION: There is provided a lighting device 1a comprising an exhaust tube 7a and a wireless communication antenna 12a arranged inside the exhaust tube 7a. There is also provided a method for producing such a lighting device.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a lighting device, typically based on solid-state lighting (SSL) technology and having a wireless communication antenna. The present invention also relates to a method for manufacturing such a lighting device. [Background technology]

[0002] Illumination devices based on SSL technology with antennas for wireless control of solid-state light sources are known in the art. The intensity and color of the emitted light can be controlled in this way, for example. Illumination devices of this kind are disclosed in WO2013014821. The illumination device has an antenna that can be arranged in or around a support for a semiconductor light emitting element. Summary of the Invention [Problem to be solved by the invention]

[0003] It would be desirable to find a way to incorporate an antenna without significant changes to the design of an existing lighting device, thus avoiding adding unnecessary cost and complexity to the manufacturing process. Complicating factors here are the fact that the technical performance of the antenna is affected by its location inside the lighting device.

[0004] It is an object of the present invention to provide an improved or alternative lighting device having a wireless communication antenna. [Means for solving the problem]

[0005] According to a first aspect, there is provided an illumination device comprising an exhaust pipe and a wireless communication antenna disposed inside the exhaust pipe.

[0006] "Exhaust tube" means a tube through which gas is introduced into the lighting device during manufacture and later sealed. Exhaust tubes are often found in General Lighting Service (GLS) bulbs, i.e. conventional incandescent bulbs. During manufacture of such bulbs, the exhaust tube allows air to be evacuated from the bulb and an inert gas to be pumped into the bulb. Modern lighting devices based on SSL technology can also have an exhaust tube for introducing gas into the envelope surrounding the solid-state light source. The gas can improve the heat transport from the solid-state light source and the life of the lighting device by reducing the lumen degradation of the solid-state light source. The exhaust tube is electrically insulated and may be made of glass, for example.

[0007] By the antenna being "internally" disposed, it is meant that at least a portion of the antenna is inside the interior space defined by the exhaust pipe. The antenna may have another portion disposed on the exterior of the exhaust pipe.

[0008] By locating the antenna inside the exhaust pipe, the antenna is mechanically well supported and the risk of the antenna being displaced due to rough handling by the end user is reduced. This is important because the antenna needs to be properly located to work optimally. Also, if the antenna is in this position, it is easier to design the lighting device so that the antenna does not interfere with the optical path of the light emitted from the solid-state light source, and the heat sink or electronics unit is at such a distance from the antenna that there is little risk of the antenna performance being degraded by e.g. shielding. Furthermore, locating the antenna inside the exhaust pipe is a simple process that adds only minor costs and complexity to the production process. For example, this still makes it possible to use many of the existing GLS production lines that are optimized for cost efficiency and speed over the long term.

[0009] According to one embodiment, an outer portion of the antenna protrudes from the open end of the exhaust pipe. Antennas usually need to have a certain length to be optimally sensitive to signals of a certain frequency. The optimal antenna length may in some cases be longer than the exhaust pipe, and a solution to this problem is to have the antenna protrude from the exhaust pipe. The portion of the antenna that protrudes from the exhaust pipe can be arranged in many different ways depending, for example, on the amount of free space inside the lighting device.

[0010] According to one embodiment, the outer portion of the antenna extends straight along the exhaust pipe.

[0011] According to one embodiment, the outer portion of the antenna is wrapped around the exhaust pipe.

[0012] According to one embodiment, the lighting device further comprises a support structure for supporting an outer portion of the antenna at a distance from the exhaust pipe.

[0013] According to an embodiment, the lighting device further comprises a tubular light source carrier attached to the exhaust pipe, the exhaust pipe being partially disposed inside the tubular light source carrier. The tubular light source carrier promotes efficient heat transport from the light source by generating convection through the carrier. In other words, the tubular light source carrier may generate a thermal chimney effect. It is noted that the carrier may also improve the reception characteristics of the antenna, for example the bandwidth. More specifically, in the case where the antenna is a linear monopole antenna, the carrier may be used to increase the capacitive coupling between the end tip of the antenna and the ground plane acting as a counterpole, thereby increasing the current at the end tip. In other words, the carrier may be used to increase the parasitic capacitance between the end tip of the antenna and the ground.

[0014] According to one embodiment, the open end of the exhaust tube is located inside the tubular light source carrier.

[0015] According to one embodiment, the exhaust pipe extends all over the tubular light source carrier such that an open end of said exhaust pipe is outside the tubular light source carrier.

[0016] According to one embodiment, the tubular light source carrier is adapted to act as a radiator, and the electrical resonant frequency of the tubular light source carrier is approximately equal to the receiving frequency of the antenna. It should be noted that the received signal typically has a frequency range, and the resonant frequency of the tubular light source carrier is in fact a narrow frequency range. This narrow frequency range is typically centered relative to the frequency range of the received signal and is much smaller than the frequency range of the received signal. The narrow frequency range may be, for example, about 4% of the frequency range of the received signal. A carrier comprising a conductive material can be made to resonate at the frequency that the antenna is configured to receive. This can improve the antenna's reception of weak signals, since the resonating carrier acts as a secondary radiator that enhances the received signal. For resonance to occur, the carrier must be positioned in the near-field region of the antenna, and the dimensions of the carrier (such as height and width) should be such that the carrier has an electrical resonant frequency that matches the frequency of the received signal.

[0017] According to one embodiment, the lighting device comprises: a connector for mechanically and electrically connecting the lighting device to a lamp socket; a light source carrier having one or more solid-state light sources; a light-transmitting envelope in which the light source carrier and the exhaust tube are disposed; a driver for providing power to the one or more solid-state light sources; and a control circuit electrically connected to the antenna and configured to control the one or more solid-state light sources. The light source carrier may, for example, be a tubular light source carrier as described above.

[0018] According to one embodiment, the control circuitry is positioned entirely inside the envelope, for example supported by the light source carrier. If the control circuitry is positioned entirely within the envelope, the antenna may be positioned upside down with respect to how it would be positioned if the control circuitry were positioned within the connector. This may make it easier to close the exhaust (as the exhaust cannot be closed if the antenna is not in that way) and may also make it easier to electrically connect the control circuitry to the solid-state light source.

[0019] According to one embodiment, the lighting device further comprises a light scattering layer and / or a wavelength conversion layer. Such layers can be arranged, for example, on the light-transmitting envelope or on the solid-state light source. The scattering layer can improve the light distribution by making the intensity or color of the light more uniform. The wavelength conversion layer may be used to change the color of the light emitted by the solid-state light source. For example, a common technique to provide white light is to combine a non-white light source with a wavelength converter. The wavelength converter converts a portion of the light emitted by the light source to a wavelength such that the mixture of the converted and unconverted light appears white or nearly white to the eye.

[0020] According to one embodiment, the lighting device is a gas filled light bulb.

[0021] According to a second aspect, there is provided a method of manufacturing a lighting device, comprising the step of arranging an antenna inside an exhaust pipe of the lighting device. The features and advantages of the second aspect are similar to those of the first aspect.

[0022] According to one embodiment, the method further comprises the step of forming an airtight connection between the antenna and the exhaust pipe.

[0023] The invention relates to all possible combinations of the features recited in the claims.

[0024] The invention will now be described in more detail with reference to the accompanying drawings. [Brief description of the drawings]

[0025] [Figure 1] FIG. 1 is a schematic exploded view of an example of a lighting device. [Diagram 2] 3 shows a schematic cross-sectional view of a further example of a lighting device; [Diagram 3] 3 shows a schematic cross-sectional view of a further example of a lighting device; [Figure 4] 3 shows a schematic cross-sectional view of a further example of a lighting device; [Diagram 5] 3 shows a schematic cross-sectional view of a further example of a lighting device; [Figure 6] 3 shows a schematic cross-sectional view of a further example of a lighting device; [Figure 7] 3 shows a schematic cross-sectional view of a further example of a lighting device; [Figure 8] 3 shows a schematic cross-sectional view of a further example of a lighting device; [Figure 9] 2 shows a flow chart of some steps of a method for manufacturing a lighting device. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0026] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. However, the present invention can be embodied in many different forms and should not be construed as being limited to the embodiments set forth herein, but rather, these embodiments are provided for completeness and completeness, so as to fully convey the scope of the present invention to those skilled in the art.

[0027] FIG. 1 shows an example of a lighting device 1 in the form of a light bulb, such as a retrofit A60 bulb. The lighting device 1 has an optical axis OA, which is the central axis of the lighting device 1. The illumination produced by the lighting device 1 is in this example substantially rotationally symmetric about the optical axis OA. A connector 2 is arranged at the end of the lighting device 1. The connector 2 mechanically and electrically connects the lighting device 1 to a lamp socket. In the illustrated example, the connector 2 is screw-based, e.g. E27 screw-based, but the connector 2 may be of a different type, e.g. a bayonet-style bulb mount. The connector 2 is typically made of metal.

[0028] The lighting device 1 comprises a light-transmitting envelope 3, the centre of which is displaced along an optical axis OA relative to the connector 2. The envelope 3 can be made of, for example, glass or plastic. In the illustrated example, the envelope 3 has a pear shape formed by a round head and a circular cylindrical neck, respectively distal and proximal to the connector 2. The envelope 3 is filled with a gas, for example helium or a mixture of helium and oxygen. Thus, the lighting device 1 is a gas-filled light bulb. On the inside of the envelope 3, a surface layer 3' may be provided. The surface layer 3' may be a light-scattering layer or a wavelength-converting layer. Examples of light-scattering layers include coatings of TiO2, BaSO4 or Al2O3 scattering particles in a silicone polymer matrix. Examples of wavelength-converting layers include coatings with one or more phosphors, such as YAG, LuAG and ECAS.

[0029] A tubular light source carrier 4 (hereafter referred to as "carrier" for brevity) is centered on the optical axis OA within the envelope 3. The carrier 4 in this example has an octagonal cross section perpendicular to the optical axis OA, but other cross-sectional shapes are possible, such as a hexagonal or circular cross section. It should be noted that other embodiments of the lighting device 1 may have a carrier that is not tubular. Several solid-state light sources 5 (hereafter referred to as "light sources" for brevity) are mounted on the carrier 4. The light sources 5 and the carrier 4 together form an L2 structure. The carrier 4 has a circuit board, e.g. a printed circuit board, that electrically connects the light sources 5. The carrier 4 is also a heat sink for the light sources 5, allowing efficient transfer of heat from the light sources 5 to the surrounding gas within the envelope 3. The light sources 5 may be, for example, semiconductor light emitting diodes, organic light emitting diodes, polymer light emitting diodes, or laser diodes. All of the light sources 5 may be configured to emit light of the same color (e.g. white light), or different light sources 5 may be configured to emit light of different colors.

[0030] A fastener 6, sometimes referred to as a "spider", in the carrier 4 attaches the carrier 4 to an exhaust tube 7 of the lighting device 1. The fastener 6 can have, for example, a protrusion that fits into a hole in the carrier 4 and a locking mechanism that clamps the exhaust tube 7. With this configuration, the carrier 4 surrounds a portion of the exhaust tube 7 such that the exhaust tube 7 is partially disposed in the interior space of the carrier 4. The exhaust tube 7 extends along an optical axis OA that coincides with the central axis of the carrier 4. The exhaust tube 7 is integrated with a stem element 8 having a larger diameter than the exhaust tube 7. The stem element 8 and the exhaust tube 7 are typically made of glass. A portion of the exhaust tube 7 is inside the stem element 8, and another portion of the exhaust tube 7 is outside the stem element 8, with the outer portion 7' ​​having an open end 7'' and supporting the support 4 via the fastener 6. The stem element 8 has a proximal portion 8' that is proximal to the connector 2 and a distal portion 8'' that is distal to the connector 2. The proximal portion 8' is sealed against the connector 2. An outer portion 7' ​​of the exhaust pipe 7 extends from the distal portion 8'' along the optical axis OA.

[0031] A contact wire 9 is fixed to the stem element 8. It should be noted that the assembly of the stem element 8, exhaust tube 7 and contact wire 9 is sometimes referred to as the "stem" of the light bulb. The contact wire 9 protrudes from the stem element 8 and electrically connects the carrier 4 to a driver 10 which provides power to the light source 5. In this example, the driver 10 is located inside the connector 2, but in other examples it may be located completely inside the envelope 3 supported by, for example, the carrier 4 or the fastener 6. An insulation portion 11 is provided between the driver 10 and the connector 2 to electrically insulate a portion of the driver 10 from the connector 2.

[0032] A wireless communication antenna 12 (hereinafter, for simplicity, referred to as "antenna") is disposed inside the exhaust pipe 7 so as to be electrically insulated from the carrier 4. The antenna 12 in this example is a linear monopole antenna. The length of the antenna 12 is typically approximately equal to □ / 4, where □ is the wavelength of the signal that the antenna 12 is configured to receive. A typical antenna has a length of approximately 3 cm. The control circuit 13 is electrically connected to the antenna 12 and to a circuit board on which the light source 5 is mounted. The control circuit 13 is configured to control the light source 5, and typically includes a microcontroller and a radio frequency receiver. The control circuit 13 is integrated with the driver 10 in this example, but may be a separate unit in other examples. The control circuit 13 may be powered by the driver 10.

[0033] Fig. 2 shows an example of a lighting device 1a similar to that of Fig. 1. The antenna 12a extends to an open end 7' without protruding from the exhaust pipe 7a. The open end 7' is located inside the carrier 4.

[0034] FIG. 3 shows a lighting device 1b similar to that of FIG. 1a, but the exhaust pipe 7b extends through the interior space of the carrier 4 such that its open end 7' is located outside the carrier 4 (or more precisely above the carrier 4).

[0035] Figure 4 shows a lighting device 1c similar to that of Figure 1, except that a portion of the antenna 12c protrudes from the open end 7' of the exhaust pipe 7c. In the example shown, the open end 7' is inside the carrier 4, and the outer portion of the antenna 12c extends straight to the outside of the carrier 4. Of course, the outer portion of the antenna 12c may be shorter in alternative examples such that it still fits completely inside the carrier 4.

[0036] FIG. 5 shows a lighting device 1d similar to that of FIG. 4, except that the outer portion of the antenna 12d is bent downwardly so as to extend straight along the outer surface of the exhaust pipe 7d.

[0037] FIG. 6 shows a lighting device 1e similar to that of FIG. 5, except that an outer portion of an antenna 12e is wrapped around the exhaust pipe 7 to form a coil.

[0038] 7 shows a lighting device 1f having a support structure 14 attached to the exhaust pipe 7f and supporting an outer portion of an antenna 12f at a distance from the exhaust pipe 7f, which in this example has a loop-like shape. Furthermore, the carrier 4 is attached to the exhaust pipe 7f via a carrier support 15 that extends upward from the connector 2 and holds the carrier 4 in place within the envelope 3.

[0039] 8 shows a lighting device 1g in which the control circuit 13 is located entirely within the envelope 3. The control circuit 13 is mounted on and supported by the light source carrier 4. The outside of the antenna 12g is electrically connected to the control circuit 13.

[0040] FIG. 9 shows a flow chart of some steps of a method for manufacturing a lighting device such as a gas-filled light bulb. The method includes step S1 of placing an antenna 12 inside a glass exhaust tube 7. The exhaust tube 7 with the antenna 12 inside is placed in a holder suitable for glass melting and fusion processes together with a glass stem element 8 and contact wires 9. The distal portion 8″ of the stem element 8 is heated to a temperature at which the glass becomes viscous, and the exhaust tube 7 is indirectly heated to the same temperature. The hot glass is pressed, forming an airtight connection between the stem element 8 and the exhaust tube 7, and between the stem element 8 and the contact wires 9. The pressing of the glass forms what is called a “pinch” on the stem element 8. After this, the glass is allowed to cool somewhat, after which a small area of ​​the pinch between the contact wires 9 is heated again and a small hole is formed through the pinch by introducing pressurized air into the exhaust tube 7. Once the stem 8 is sealed to the envelope 3, the hole allows the exhaust tube 7 to be connected to the interior of the light bulb. The light source carrier 4 with the solid-state light source 5 is then attached to the exhaust tube 7 and electrically connected to the contact wires 9, for example by welding. The whole assembly is placed in a glass envelope 3, which is sealed to the proximal part 8' of the stem element 8 by heating the glass from the outside while the stem and envelope assembly is rotated. The bulb is then flushed, filled and closed in a process called "pumping and chipping". The interior of the envelope 3 is cleaned by repeated flushing with an inert gas, and a special type of valve is used to control the air flow through the exhaust tube 7. The filling gas is pumped into the cleaned envelope 3 through the exhaust tube 3 by the filling system. Then, in step S2, an airtight connection between the antenna 12 and the exhaust tube 7 is formed, so that the filling gas cannot escape from the envelope 3 through the exhaust tube 7. This can be done by heating the exhaust tube 7 and pressing the heated exhaust tube 7 against the antenna 12, between the envelope 3 and the valve. The portion of the exhaust pipe 7 that is outside the envelope 3 is removed, for example by "scoring and breaking" the exhaust pipe 7.This involves creating a weak spot that allows the exhaust tube 7 to be broken at a precise point. The weak spot can be created, for example, by scratching the exhaust tube 7 with a diamond knife or by locally reducing the diameter of the exhaust tube 7 by heat and pressure. A part of the antenna 12 usually protrudes from the end where the exhaust tube 7 is broken. However, if the antenna 12 is mounted upside down, the exhaust tube 7 can be broken so that the antenna 12 does not protrude from the exhaust tube 7 later. Finally, the connector 2 is attached to the envelope 3 and the electronic circuitry in the connector 2 is connected to the contact wires 9 and the antenna 12, for example by electrical welding or soldering, or by a drilled or poked-in connector.

[0041] The lighting device is operated by plugging the connector 2 into an electrical socket connected to a power source, whereby the driver 10 supplies power to the light source 5 via contact wires 9 and the carrier 4. The light source 5 emits light that is transmitted through the envelope 3. A mobile device, such as a smartphone, can be used to control the light source 5 by sending radio frequency signals to the antenna 12. The signals received by the antenna 12 are processed by a control circuit 13 which controls the light source 5. Depending on the application, it is possible, for example, to turn the light source on and off, to dim the light source or to change the color settings of the lighting device.

[0042] Those skilled in the art will understand that the present invention is in no way limited to the preferred embodiment described above. On the contrary, many modifications and variations are possible within the scope of the appended claims. For example, the shape of the envelope 3 is not limited to a pear shape. Some examples of other envelope shapes include a cylindrical shape, an elliptical shape, and a conical shape.

[0043] Furthermore, variations to the disclosed embodiments can be understood and effected by those skilled in the art in practicing the claimed invention, from a study of the drawings, the disclosure and the appended claims. In the claims, the word "comprising" does not exclude other elements or steps, and the singular 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.

Claims

1. Exhaust pipe and a wireless communication antenna disposed inside the exhaust pipe; A lighting device having The lighting device further comprises an airtight connection between the antenna and the exhaust pipe.

2. The lighting device of claim 1 , wherein an outer portion of the antenna protrudes from an open end of the exhaust pipe.

3. 3. The lighting device according to claim 2, wherein the outer portion of the antenna extends linearly along the exhaust pipe.

4. 4. The lighting device of claim 2 or 3, wherein an outer portion of the antenna is wrapped around the exhaust pipe.

5. 5. The lighting device of claim 2, further comprising a support structure for supporting the outer portion of the antenna at a distance from the exhaust pipe.

6. 6. A lighting device according to claim 1, further comprising a tubular light source carrier attached to said exhaust pipe, said exhaust pipe being partially disposed inside said tubular light source carrier.

7. The lighting device according to claim 6 , wherein an open end of the exhaust pipe is located inside the tubular light source carrier.

8. 7. The lighting device of claim 6, wherein the exhaust tube extends throughout the tubular light source carrier such that an open end of the exhaust tube extends outside the tubular light source carrier.

9. 9. A lighting device according to any one of claims 6 to 8, wherein the tubular light source carrier (12) is adapted to act as a radiator, the electrical resonant frequency of the tubular light source carrier (12) being approximately equal to a receiving frequency of the antenna (12).

10. a connector for mechanically and electrically connecting the lighting device to a lamp socket; a light source carrier having one or more solid state light sources; a light-transmitting envelope; and the light source carrier and the exhaust pipe disposed within the envelope; a driver for powering the one or more solid state light sources; a control circuit electrically connected to the antenna and controlling the one or more solid-state light sources; 10. The lighting device according to claim 1 , further comprising:

11. 11. The lighting device of claim 10, wherein the control circuitry is disposed entirely inside the envelope.

12. 12. The illumination device of claim 10 or 11, further comprising at least one of a light scattering layer and a wavelength converting layer.

13. A lighting device as claimed in any one of claims 1 to 12, which is a gas-filled light bulb.

14. disposing an antenna within an exhaust pipe of a lighting device; forming an airtight connection between the antenna and the exhaust pipe; A method for manufacturing a lighting device comprising:

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