Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F21—LIGHTING
  • F21K—NON-ELECTRIC LIGHT SOURCES USING LUMINESCENCE; LIGHT SOURCES USING ELECTROCHEMILUMINESCENCE; LIGHT SOURCES USING CHARGES OF COMBUSTIBLE MATERIAL; LIGHT SOURCES USING SEMICONDUCTOR DEVICES AS LIGHT-GENERATING ELEMENTS; LIGHT SOURCES NOT OTHERWISE PROVIDED FOR
  • F21K9/00—Light sources using semiconductor devices as light-generating elements, e.g. using light-emitting diodes [LED] or lasers
  • F21K9/20—Light sources comprising attachment means
  • F21K9/23—Retrofit light sources for lighting devices with a single fitting for each light source, e.g. for substitution of incandescent lamps with bayonet or threaded fittings
  • F21K9/232—Retrofit light sources for lighting devices with a single fitting for each light source, e.g. for substitution of incandescent lamps with bayonet or threaded fittings specially adapted for generating an essentially omnidirectional light distribution, e.g. with a glass bulb
• • H—ELECTRICITY
  • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
  • H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
  • H05B45/00—Circuit arrangements for operating light-emitting diodes [LED]
  • H05B45/10—Controlling the intensity of the light
• • H—ELECTRICITY
  • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
  • H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
  • H05B45/00—Circuit arrangements for operating light-emitting diodes [LED]
  • H05B45/20—Controlling the colour of the light
• • H—ELECTRICITY
  • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
  • H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
  • H05B45/00—Circuit arrangements for operating light-emitting diodes [LED]
  • H05B45/30—Driver circuits
  • H05B45/357—Driver circuits specially adapted for retrofit LED light sources
  • H05B45/3574—Emulating the electrical or functional characteristics of incandescent lamps
  • H05B45/3577—Emulating the dimming characteristics, brightness or colour temperature of incandescent lamps
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F21—LIGHTING
  • F21Y—INDEXING SCHEME ASSOCIATED WITH SUBCLASSES F21K, F21L, F21S and F21V, RELATING TO THE FORM OR THE KIND OF THE LIGHT SOURCES OR OF THE COLOUR OF THE LIGHT EMITTED
  • F21Y2103/00—Elongate light sources, e.g. fluorescent tubes
  • F21Y2103/10—Elongate light sources, e.g. fluorescent tubes comprising a linear array of point-like light-generating elements
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F21—LIGHTING
  • F21Y—INDEXING SCHEME ASSOCIATED WITH SUBCLASSES F21K, F21L, F21S and F21V, RELATING TO THE FORM OR THE KIND OF THE LIGHT SOURCES OR OF THE COLOUR OF THE LIGHT EMITTED
  • F21Y2113/00—Combination of light sources
  • F21Y2113/10—Combination of light sources of different colours

Definitions

• the present invention relates to LED filaments, i.e. linear arrays of LEDs arranged on a carrier substrate, used e.g. in retrofit light bulbs. Specifically, the present invention relates to color controllable LED filaments.
• Incandescent lamps are rapidly being replaced by LED based lighting solutions. It is nevertheless appreciated and desired by users to have retrofit lamps which have the look of an incandescent bulb. For this purpose, one can simply make use of the infrastructure for producing incandescent lamps based on glass and replace the filament with LEDs emitting white light.
• One of the concepts is based on LED filaments placed in such a bulb. The appearances of these lamps are highly appreciated as they look highly decorative.
• a light emitting device configured to emit light with a total color temperature
• the light emitting device comprising at least one first light emitting diode (LED) filament, and at least one second LED filament, wherein each of the at least one first LED filament and the at least one second LED filament comprises an elongated substrate, and an array of light emitting diodes mounted on the substrate; and a controller for individually controlling the at least first LED filament and the at least one second LED filament.
• LED light emitting diode
• the at least one first LED filament is arranged to emit light of a first color temperature, the first color temperature being controllable in a first color temperature range, from CTi low to CTi hlgh , wherein the at least one second LED filament is arranged to emit light of a second color temperature, the second color temperature being controllable in a second color temperature range, from CT 2 low to CT 2 hlgh , and wherein the controller is configured to control the total color temperature (CT tot ) from a first total color temperature (CT tot, I) to a second total color temperature (CT tot, 2 ) by controlling the first color temperature, and the second color temperature according to a preselected control scheme, such that the difference between the first color temperature and the second color temperature (ACT) is not constant during changing CT tot from CT tot, 1 , to CT tot, 2 ’, which is also referred to as the change of the total color temperature (CT tot ).
• CT tot total color temperature
• CTi low and CT 2 low correspond to a starting point of the control scheme with an initial difference of ACT start , and summing up to CT tot,i . Therefore, CT tot,i and ACT start correspond to the same point in time.
• CTi hlgh and CT 2 hlgh correspond to an ending point of the control scheme with a final difference of ACT end , and summing up to CT tot, 2 . Therefore, CT tot, 2 and ACT end correspond to the same point in time.
• CTi low and CT2 low are preferably in the range from 1800 to 2500 K, more preferably from 2000 to 2400 K, most preferably from 2100 to 2300 K.
• CT i h ' gl1 and CT2 hlgh is preferably in the range from 2700 to 4500 K, more preferably from 2900 to 4000 K, most preferably from 3000 to 3500 K.
• the color temperatures of the first and second LED filaments may be controlled in various ways.
• the controller can be configured to change the first and second color temperature by controlling all LEDs of each LED filament simultaneously. In other words, all LEDs of a LED filament are controlled to emit light of the same color temperature. This may lead to a uniform control of all the LEDs on a filament.
• the controller is configured to change the first and second color temperature by controlling LEDs of each LED filament individually. In other words, one subset of the LEDs of a LED filament may emit light of one color temperature, while another subset emits light of another color temperature. This may lead to an LED-specific control.
• the LED filaments and the controller maybe comprised in a single device, resulting in a relatively compact color-controllable LED filament lighting device.
• Figs. 3a-3c illustrate different embodiments of LED filaments from which color tunable white light is emitted.
• Figs. 5a, 5b, 5c and 5d show illustrative plots of different preselected control schemes for increasing the total color temperature of the light emitting device.
• Fig. 6 demonstrates a flow chart describing the stages of the preselected control scheme.
• CTi low and CT2 low are preferably in the range from 1800 to 2500 K, more preferably from 2000 to 2400 K, most preferably from 2100 to 2300 K.
• CT 1 h ' gl1 and CT2 h ' sl1 is preferably in the range from 2700 to 4500 K, more preferably from 2900 to 4000 K, most preferably from 3000 to 3500 K.
• the LED filaments 100 of the lighting device the lamp 10 shown in figure 1 can be described as follows.
• Figure 2 demonstrates such an LED filament 100.
• the LEDs 110 are arranged on an elongated carrier 120 for instance a substrate.
• the terms “carrier” and “substrate” may be used interchangeably, and unless stated otherwise, are meant to imply the same meaning.
• the LED filament 100 has a length L and a width W, wherein L>5W.
• the LED filamentlOO may be arranged in a straight configuration similar to figure 2, or in a non straight configuration such as for example a curved configuration, a 2D/3D spiral or a helix.

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• Engineering & Computer Science (AREA)
• Physics & Mathematics (AREA)
• Microelectronics & Electronic Packaging (AREA)
• Optics & Photonics (AREA)
• General Engineering & Computer Science (AREA)
• Non-Portable Lighting Devices Or Systems Thereof (AREA)
• Arrangement Of Elements, Cooling, Sealing, Or The Like Of Lighting Devices (AREA)

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Publications (1)

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• 2020
  • 2020-12-21 CN CN202080091650.5A patent/CN114902809A/zh active Pending
  • 2020-12-21 EP EP20830240.6A patent/EP4085734B1/en active Active
  • 2020-12-21 JP JP2022540820A patent/JP2023509164A/ja active Pending
  • 2020-12-21 WO PCT/EP2020/087434 patent/WO2021136708A1/en not_active Ceased
  • 2020-12-21 US US17/787,987 patent/US12188622B2/en active Active

Patent Citations (5)

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