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A LIFI DEVICE

20220397243 · 2022-12-15

    Inventors

    Cpc classification

    International classification

    Abstract

    The one or more LED filaments (110) are arranged to form an inner space. At least one of the one or more LED filaments (110) is arranged as a LiFi transmitter. The LiFi device (100) further comprises a light sensor (120) arranged within the inner space. The light sensor (120) is arranged as a LiFi receiver. The LiFi device further comprises an envelope arranged to envelope the one or more LED filaments (110) and the light sensor (120). The one or more LED filaments (110) are further arranged such that the LED filament light is directed towards the envelope.

    Claims

    1. A LiFi device (100) comprising: one or more LED filaments (110) configured to emit LED filament light, wherein the one or more LED filaments (110) are arranged to form an inner space, wherein at least one of the one or more LED filaments (110) is arranged as a LiFi transmitter, a light sensor (120) arranged within the inner space, wherein the light sensor (120) is arranged as a LiFi receiver, an envelope arranged to envelope the one or more LED filaments (110) and the light sensor (120), wherein the one or more LED filaments (110) are further arranged such that the LED filament light is directed towards the envelope, and wherein the LiFi device (100) is further comprising a light concentrator (125) arranged within the inner space and optically connected with the light sensor (120).

    2. The LiFi device (100) according to claim 1, wherein the one or more LED filaments (110) are arranged as a spiral or loop around the light sensor (120).

    3. The LiFi device (100) according to claim 1 or 2, wherein the one or more LED filaments (110) comprises an elongated carrier having a first major surface and a second major surface opposite to the first major surface, wherein the one or more LED filaments (110) are arranged on the first major surface and no LED is arranged on the second major surface, and wherein the first major surface is facing away from the inner space.

    4. The LiFi device (100) according to any one of claims 1-3, wherein the one or more LED filaments (110) comprises a reflector configured to reflect the LED filament light in a direction away from the light sensor.

    5. The LiFi device (100) according to claim 4, wherein the one or more LED filaments (110) are arranged as a spiral or loop around the light concentrator (125).

    6. The LiFi device (100) according to claim 4 or 5, wherein the light concentrator (125) is a luminescent light concentrator.

    7. The LiFi device (100) according to any one of claims 4-6, wherein the light concentrator (125) is in the form of a slab, a rod or a fiber.

    8. The LiFi device (100) according to any one of claims 1-7, wherein each of the one or more LED filaments (110) comprises a plurality of LEDs and a sub portion of the plurality of LEDs are arranged as the LiFi transmitter.

    9. The LiFi device (100) according to claim 8, wherein the sub portion of the plurality of LEDs arranged as the LiFi transmitter are infrared, IR, LEDs (150).

    10. The LiFi device (100) according to any one of claims 1-9, further comprising a modulation circuit (160), wherein a modulation current from the modulation circuit (160) is applied to LEDs of the one or more LED filaments (110) constituting the LiFi transmitter.

    11. The LiFi device (100) according to any one of claims 1-10, wherein the LiFi receiver further comprises a selective wavelength filter.

    12. The LiFi device (100) according to claim 11, wherein the selective wavelength filter is configured to transmit IR-light and to block visible light.

    13. The LiFi device (100) according to any one of claims 1-12, wherein the one or more LED filaments (110) are arranged at a distance>5 mm from the light sensor (120).

    14. Use of the LiFi device (100) according to any one of claims 1-13, for sending and receiving LiFi signals.

    Description

    BRIEF DESCRIPTION OF THE DRAWINGS

    [0031] The above and other aspects of the present invention will now be described in more detail, with reference to the appended figures showing embodiments of the invention. The figures describe LiFi devices comprised in bulbs of incandescent lamps. However, the figures should not be considered limiting the invention to the lamps; instead they are used for explaining and understanding the invention.

    [0032] FIGS. 1-4 illustrate side views of four different embodiments of LED-lamps each constituting a LiFi device.

    [0033] FIGS. 5-6 illustrate side views of two different embodiments of LED-lamps each constituting a LiFi device with IR LEDs as LiFi transmitters.

    [0034] FIG. 7 illustrates a modulation circuit.

    [0035] As illustrated in the figures, the sizes of components are exaggerated for illustrative purposes and, thus, are provided to illustrate the general structures of embodiments of the present invention. Like reference numerals refer to like elements throughout.

    DETAILED DESCRIPTION

    [0036] The present invention will now be described more fully hereinafter with reference to the accompanying drawings, in which currently preferred embodiments of the invention are shown. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided for thoroughness and completeness, and fully convey the scope of the invention to the skilled person.

    [0037] In connection with FIG. 1, a lamp 10 is illustrated. L denotes a longitudinal direction of the lamp 10. FIG. 1 shows that the lamp 10 comprises an envelop 130 in the form of a bulb 130. The bulb 130, shown in FIG. 1, has a neck portion 130n and a dome portion 130d. The bulb 130 extends from the neck portion 130n towards the dome portion 130d along the longitudinal direction L of the lamp 10. The bulb 130 shown in FIG. 1 looks similar to bulbs of the incandescent lamps. The neck portion 130n of the bulb 130 has a smaller dimension e.g. a smaller diameter with respect to the dome portion 130d. The bulb 130 may have other shapes. The bulb 130 shown in FIG. 1 is formed of glass. The bulb 130 may be formed of various materials. The bulb may be formed in a manner which per se is known in the art.

    [0038] FIG. 1 further shows that the lamp 10 comprises a cap 140. The neck portion 130n of the bulb 130 is connected to the cap 140. The cap 140 may allow the lamp 10 to be safely and conveniently connected to a lamp holder. The cap 140 may comprise electronic components for providing electricity to LEDs and LiFi devices. In this case, the neck portion 130n of the bulb 130 may not be translucent.

    [0039] FIG. 1 further shows that the lamp 10 comprises a LiFi device 100. The LiFi device 100 of FIG. 1 comprises one or more LED filaments 110. The one or more LED filaments 110 are configured to emit LED filament light. FIG. 1 further shows that the one or more LED filaments 110 are arranged as a helix along the longitudinal direction L of the lamp 10. The one or more LED filaments 110 are arranged to form an inner space i.e. the space inside the helix. The one or more LED filaments 110 may be arranged as a loop. The one or more LED filaments 110 may be arranged in other forms, provided that the one or more LED filaments 110 form an inner space. A typical size (S) of the one or more LED filaments 110, in the form of a helix shown in FIG. 1, may be in a range of 20 mm to 50 mm, along the longitudinal direction L of the lamp 10. A typical size of the one or more LED filaments, in the form of a helix shown in FIG. 1, may be in a range of 15 mm to 30 mm, in any direction opposite to the longitudinal direction L of the lamp 10.

    [0040] Each of the one or more LED filaments 110 may comprise a plurality of LEDs. The one or more LED filaments 110 of FIG. 1 are further arranged such that the LED filament light is directed towards the envelope. In other words, the one or more LED filaments 110 of FIG. 1 are arranged to emit light outwards i.e. out from the LiFi device 100. The one or more LED filaments 110 of FIG. 1 emit no light or very little light towards the inner space. The one or more LED filaments 110 may comprises an elongated carrier having a first major surface and a second major surface opposite to the first major surface. The one or more LED filaments 110 may be arranged on the first major surface. The first major surface may face away from the inner space. The second major surface may face the inner surface. No LED may be arranged on the second major surface. For instance, the one or more LED filaments 110 may be arranged as a helix such that the first major surface comprising the plurality of LEDs may face outwards i.e. away from an inner space of the helix. In other words, the second major surface i.e. not comprising a plurality of LEDs may face towards the inner surface.

    [0041] Alternatively, or in combination, the one or more LED filaments 110 may comprise a reflector. In other words, the reflector may be arranged at a surface facing the inner space. The reflector may be formed such that it may reflect light emitted by the one or more LED filaments 110 away from the inner space. In the case of having the reflector, the one or more LED filaments 110 may comprise a plurality of LEDs on all surfaces. The reflector may be formed of e.g. polished aluminium. The reflector may be applied as a metallic mirror coating or white reflective silicon. For instance, the elongated carrier may be a glass or a polymer substrate. The elongated carrier may be coated with a reflective coating such as a thin layer of Aluminium or silver, or a coating of a polymer matrix with Al.sub.2O.sub.3, BaSO.sub.4, and/or TiO.sub.2 particles, or other reflective flakes.

    [0042] Still referring to FIG. 1, the one or more LED filaments 110 are arranged as a LiFi transmitter of the LiFi device 100. As mentioned above, each of the one or more LED filaments 110 may comprise a plurality of LEDs. A sub portion of the plurality of LEDs may be arranged as the LiFi transmitter. Another sub portion of the plurality of LEDs may be used for lighting purpose. For instance, the another sub portion of the plurality of LEDs may comprise LEDs emitting white light. The another sub portion of the plurality of LEDs may preferably have a color temperature in the range of 1800 to 5000 K and a color rendering index may preferably be at least 80. The another sub portion of the plurality of LEDs may have various shapes and forms for decorative purpose.

    [0043] FIG. 1 further shows that the LiFi device 100 comprises a light sensor 120. FIG. 1 shows that the light sensor 120 is arranged within the inner space, formed by the one or more LED filaments 110. FIG. 1 shows that the one or more LED filaments 110 are arranged as the helix around the light sensor 120. The one or more LED filaments 110 may be arranged as a spiral or a loop around the light sensor 120. The one or more LED filaments 110 may be arranged in other forms around the light sensor 120, provided that the one or more LED filaments 110 form an inner space. The light sensor 120 may be arranged in the cap 140 or the neck portion 130n of the bulb 130. In the case of the reflector, the reflector may be configured to reflect the LED filament light in a direction away from the light sensor 120.

    [0044] Still referring to FIG. 1, the light sensor 120 is arranged as a LiFi receiver of the LiFi device 100. The light sensor 120 may comprise e.g. PIN— or Avalanche photodiodes. A typical area of the light sensor 120 may be in a range of 1 mm.sup.2 to 40 mm.sup.2. The one or more LED filaments 110 may be arranged at a distance>5 mm from the light sensor 120.

    [0045] Still referring to FIG. 1, the LiFi device 100 further comprise a light concentrator 125 arranged within the inner space formed by the one or more LED filaments 110. The light concentrator 125 may be optically connected with the light sensor 120. The light concentrator 125 may be a luminescent light concentrator 125. The light concentrator 125 may be formed of a polymer matrix material comprising an organic phosphor. The light concentrator 125 may be in the form of a slab, a rod or a fiber. The light concentrator 125 may also have an irregular shape such as a meander. FIG. 1 shows that the light concentrator 125 is in the form of a rod. A typical size of a light concentrator 125 shown in FIG. 1 may be in a range of 10 mm to 60 mm along the longitudinal direction L of the lamp 10. A typical size of the light concentrator 125 may be in a range of 2 mm to 15 mm in other directions opposite to the longitudinal direction L of the lamp 10.

    [0046] The light concentrator 125 may be a luminescent light concentrator. The luminescent light concentrator 125 may have a height H. The height of the luminescent light concentrator 125 may be in a range from a half (0.5S) to a complete (1S) size of the one or more LED filaments 110 along the longitudinal direction L of the lamp. A length of the luminescent light concentrator is preferably at least 2 cm, more preferably at least 3 cm, most preferable at least 4 cm. A surface area of the luminescent light concentrator is preferably at least 3 cm.sup.2, more preferably at least 5 cm.sup.2, most preferably at least 7 cm.sup.2.

    [0047] Still referring to FIG. 1, the light concentrator 125 may be optically connected to the light sensor 120. For instance, the light sensor 120 may be arranged at one of the ends of the light concentrator 125. FIG. 1 shows that the light sensor 120 is arranged at an upper end of the light concentrator 125 i.e. the end of the light concentrator 125 close to the dome portion 130d of the lamp 100. The light sensor 120 may alternatively be arranged at a lower end of the light concentrator 125 i.e. the end of the light concentrator 125 close to the neck portion 130n of the lamp 100.

    [0048] In connection with FIG. 2, another lamp 10 is shown. FIG. 2 illustrates that the one or more LED filaments 110 and the light concentrator 125 extend in a direction opposite to the longitudinal direction L of the lamp 10. In FIG. 2, the light sensor 120 is attached to a left end of the light concentrator 125. The LiFi device of FIG. 2 is connected to the neck portion 130n of the lamp 10 by a supporting means 170.

    [0049] In connection with FIG. 3, yet another lamp 10 is shown. The one or more LED filaments 110 of FIG. 3 are arranged like ribs of an umbrella around the light concentrator 125. The LiFi device of FIG. 3 is connected to the neck portion 130n of the lamp 10 by a supporting means 170.

    [0050] In connection with FIG. 4, yet another lamp 10 is shown. The one or more LED filaments 110 of FIG. 4 have similar shape and form of the one or more LED filaments 110 of FIG. 1. The light concentrator 125 of FIG. 4 is arranged in the form of a meander within the inner space. FIG. 4 shows that the light sensor 120 is comprised in an upper portion of the light concentrator 125. The light sensor 120 may be comprised in a middle portion or a lower portion of the light concentrator 125.

    [0051] In connection with FIG. 5, a lamp 10 is shown wherein a sub portion of the plurality of LEDs arranged as the LiFi transmitter are infrared, IR, LEDs 150. The one or more LED filaments 110 of FIG. 5 are arranged like ribs of an umbrella around the light concentrator 125. FIG. 5 shows that the IR LEDs are 150 arranged in the one or more LED filaments 110 i.e. the IR LEDs 150 are arranged in middle portions of the ribs of the umbrella around the light concentrator 125. The IR LEDs 150 may be arranged in lower or upper portions of the ribs of the umbrella around the light concentrator 125. The LiFi device of FIG. 5 is connected to the neck portion 130n of the lamp 10 by a supporting means 170.

    [0052] In connection with FIG. 6, another lamp 10 is shown wherein a sub portion of the plurality of LEDs arranged as the LiFi transmitter are infrared, IR, LEDs 150. The one or more LED filaments 110 of FIG. 6 are arranged like ribs of an umbrella around the light concentrator 125. FIG. 6 shows that the IR LEDs 150 are arranged above, along the longitudinal direction (L) of the lamp 10, and in contact with the one or more LED filaments 110. The LiFi device of FIG. 6 is connected to the neck portion 130n of the lamp 10 by a supporting means 170.

    [0053] In connection with FIG. 7, the LiFi device 100 may further comprise a modulation circuit 160. The modulation circuit 160, shown by I.sub.mod, capacitors and inductors in FIG. 7, may separate the modulation current form a constant current shown by I.sub.dc in FIG. 7. FIG. 7 shows that the modulation current has been bypassed by means of parallel capacitors on a plurality of LEDs 112, 114, 116, 118 providing visible light. Thereby the constant current has been applied to the plurality of LEDs 112, 114, 116, 118. FIG. 7 further shows that the modulation current has been applied to an IR LED 152. The IR LED 152 may be one of the one or more LED filaments constituting the LiFi transmitter. The modulation circuit 160 may be comprised in a LiFi device 100 or a lamp 10 having the IR LEDs as the LiFi transmitter such as the lamps shown in FIGS. 5 and 6.

    [0054] The LiFi device 100 may further comprise a selective wavelength filter. The selective wavelength filter may be configured to transmit IR-light and to block visible light. The selective wavelength filter may be a sensor sensitive to a certain wavelength range such as IR wavelength range e.g. bandpass, edgepass, dichroic filters or even beam-split filters.

    [0055] 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. 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 measured cannot be used to advantage.