Adjustable light spiral LED filament device and lamp

Abstract

This disclosure relates to an LED filament system (100) comprising an LED filament assembly (105) and a controller (120). The LED filament assembly comprises a plurality of LED filaments (110a-110c). The LED filaments are wound around a common central axis (A) such that each LED filament has a helical shape. In the LED filament assembly, the translational distance (t) along the central axis between two adjacent LED filaments is different. The controller is configured to control the power supply to the LED filaments such that at least one of the plurality of LED filaments can be individually controlled. The controller is further configured to control the power supply to the LED filaments in a first mode in which all LED filaments are in an on state and the controller provides a power supply to the LED filaments above a first power level. The controller is further configured to control the power supply to the LED filaments in a second mode in which at least one of the LED filaments is in an off state.

Description

Technical Field

[0001] This invention generally relates to the field of solid-state lighting. Specifically, this invention relates to LED filament devices and LED filament lamps. Background Technology

[0002] Incandescent bulbs are being rapidly replaced by LED-based lighting solutions. However, users can understand and expect the availability of custom lamps that retain the appearance of incandescent bulbs.

[0003] Solid-state lighting devices offer many advantages over their incandescent, fluorescent, and gas discharge-based counterparts. For example, they can provide increased operating life, reduced power consumption, and higher efficiency. Solid-state lighting devices, such as LEDs, are used in a wide range of lighting applications.

[0004] The development of LED-based lighting devices is ongoing and can provide new solutions that extend far beyond what is possible with traditional light sources.

[0005] CN 209672092 discloses a light bulb comprising a bulb housing, a heat sink, and a head housing arranged in series along the longitudinal axis of the bulb. The bulb includes a first filament and a second filament. The first filament has a first LED chip capable of emitting first light having a first color characteristic, and the second filament has a second LED chip capable of emitting second light having a second color characteristic. The first and second filaments are helical along a transverse axis perpendicular to the longitudinal axis of the bulb. The bulb further includes a driving module configured to enable one or a combination of the first and second filaments to emit light. Summary of the Invention

[0006] A general objective of this invention is to provide a low-cost, dimmable LED filament system with a comfortable appearance.

[0007] Therefore, the object of the present invention is to satisfy at least some of the above-mentioned objectives and to provide an improved lighting solution.

[0008] This and other objectives are achieved by the LED filament system as defined in the appended independent claims. Other embodiments are defined by the dependent claims.

[0009] According to a first aspect of the present invention, a light-emitting diode (LED) filament system is provided. The LED filament system includes an LED filament assembly comprising a plurality of LED filaments. The plurality of LED filaments are wound around each other about a common central axis, such that each LED filament has a helical shape. Adjacent LED filaments have different translational spacings along the common central axis.

[0010] The LED filament system further includes a controller. The controller is configured to control the power supply to the LED filaments, such that at least one of the plurality of LED filaments can be controlled individually. Furthermore, the controller is configured to control the power supply to the LED filaments in a first mode, in which all LED filaments are on, and the controller provides the LED filaments with a power supply higher than a first power level. The controller is also configured to control the power supply to the LED filaments in a second mode, in which at least one LED filament is off.

[0011] It should be understood that the positions of the different LED filaments within an LED filament assembly are not uniform. Instead, the corresponding arrangement of the LED filaments can vary by translation along the central axis and / or rotation about the central axis. The translation spacing is the distance between two adjacent LED filaments in the direction along the central axis of the LED filament assembly.

[0012] The controller can control the luminous flux of an LED filament device by controlling the power supply to the LED filament. Controlling the light source to provide a luminous flux below its maximum can be described as dimming the light source. This ability to dim the light source is highly appreciated by users.

[0013] This LED filament system can provide a dimmable lighting solution at a low cost.

[0014] According to some embodiments, for a given translational spacing (t), the LED filament device can provide a light distribution corresponding to a uniform light-emitting surface in a first mode, and a light distribution corresponding to at least one light-emitting spiral in a second mode.

[0015] The controller can control the LED filament assembly (in a first mode) such that all LED filaments are illuminated (emitting light in the on state). The arrangement of the LED filaments can provide the appearance of a light source from a (single) emitting surface or a volumetric light source. When all LED filaments of the LED filament assembly are illuminated and when they emit light exceeding a certain intensity (corresponding to a first power level provided by the controller), the arrangement of the LED filaments can provide the appearance of a light source from a single tubular / cylindrical emitting surface. The controller can also control the LED filament assembly (in a second mode) such that at least one LED filament is not illuminated (not emitting light in the off state), which can provide the appearance of one or more spiral LED filaments.

[0016] According to some embodiments, in an LED filament device, the translation pitch (t) can be in the range of 1 to 5 times the width (w) of one LED filament (i.e., lw≤t≤5w).

[0017] For example, the translation spacing can be in the range of 2 to 4.5 times the width (i.e., 2w ≤ t ≤ 4.5w). More specifically, the translation spacing can be in the range of 3 to 4 times the width (i.e., 3w ≤ t ≤ 4w).

[0018] Using an example where the LED filament width is 2.5mm, the translation spacing can be in the range of 2.5–12.5mm. Specifically, in an embodiment where the LED filament width is 2.5mm, the translation spacing can be in the range of 5–11.25mm. More specifically, in an embodiment where the LED filament width is 2.5mm, the translation spacing can be in the range of 7.5–10mm.

[0019] The translation spacing according to this embodiment can provide a balance between improved thermal management and the appearance of a continuously emitting surface when all LED filaments are illuminated.

[0020] According to some embodiments, each LED filament can be arranged in a helical shape with a substantially constant helical pitch. The helical pitch can be the distance between consecutive loops of the helical shape.

[0021] An embodiment in which each LED filament is arranged in a spiral shape with a substantially constant spiral spacing can provide a more uniform light distribution and a more comfortable appearance.

[0022] For example, the pitch of the screws can differ by less than 20%. Specifically, the pitch of the screws can differ by less than 10%. More specifically, the pitch of the screws can differ by less than 5%.

[0023] According to some embodiments, the helical pitch (p) can be in the range of 8 times to 20 times the width (w) of the LED filament (i.e., 8w≤p≤20w).

[0024] For example, the helical pitch can be in the range of 10 to 19 times the width (i.e., 10w ≤ p ≤ 19w). Specifically, the helical pitch can be in the range of 12 to 18 times the width (i.e., 12w ≤ p ≤ 18w). More specifically, the helical pitch can be in the range of 14 to 16 times the width (i.e., 14w ≤ p ≤ 16w).

[0025] Using an example where the LED filament width is 2.5mm, the helical pitch can be in the range of 20-50mm. Specifically, if the LED filament width is 2.5mm, the helical pitch can be in the range of 22.5-45mm. More specifically, when the LED filament width is 2.5mm, the helical pitch can be in the range of 25-37.5mm.

[0026] According to some embodiments, the width (w) of the LED filament can be in the range of 1 to 4 mm.

[0027] For example, the width can range from 1.8 to 3.5 mm. More specifically, the width can range from 2 to 3 mm.

[0028] The pitch aspect ratio (PAR) can be defined as the ratio of the helical pitch to the translational pitch (i.e., PAR = p / t). For example, PAR can be in the range of 2 to 8. Specifically, PAR can be in the range of 3 to 6. More specifically, PAR can be in the range of 4 to 5.

[0029] According to some embodiments, the controller can be configured to receive an input signal representing a desired luminous flux. The controller can be further configured to select at least one LED filament to which power is supplied based on the desired luminous flux. Furthermore, the controller can be configured to select a power level of at least one LED filament to provide the desired luminous flux, and to supply power to at least one selected LED filament according to the selected power level.

[0030] It should be understood that when more than one LED filament is selected, each LED filament can receive an individual power level. For some or all LED filaments, the individual power levels can be the same. For some or all LED filaments, the individual power levels can be different. When more than one LED filament is selected, the controller can provide power to each selected LED filament according to its individual power level. Alternatively, two or more LED filaments can be controlled together. For example, two or more LED filaments can be connected in series or in parallel.

[0031] The individual (or group) power of LED filaments can provide a dimming solution where, for the desired total luminous flux of the LED filament assembly, a subset of the LED filaments can be illuminated to provide a higher flux level, rather than all LED filaments being illuminated to provide the same, lower flux level. This dimming solution can be more effective than conventional dimming because the LED filaments can be operated closer to their optimal efficiency.

[0032] According to some embodiments, if the desired luminous flux is below a first limit, the controller can be configured to supply power to only one LED filament.

[0033] An illuminated LED filament and the remaining LED filaments turned off can give an LED filament arrangement the appearance of a single LED filament. For low luminous flux levels, such as below 450 lm, using a single LED filament can provide the most comfortable appearance and lighting.

[0034] According to some embodiments, if the desired luminous flux is higher than the second limit, the controller can be configured to supply power to all LED filaments.

[0035] For high luminous flux, such as above 600 lm, all LED filaments can be illuminated. In embodiments where the LED filaments are closely arranged together, illuminating all LED filaments can provide the appearance of a continuous cylindrical light source. For high luminous flux levels, the appearance of the luminous surface can provide the most comfortable appearance and illumination.

[0036] According to some embodiments, if the desired luminous flux is higher than a threshold corresponding to the maximum flux level of the first LED filament, the controller may be further configured to provide power to the first LED filament corresponding to the maximum flux level. The controller may also be further configured to provide power to the second LED filament to achieve the desired luminous flux.

[0037] For example, to achieve a desired luminous flux level using only one LED filament, only the first LED filament can be powered. When the desired luminous flux level exceeds the luminous flux level that can be provided by a single LED filament, the first LED filament can be powered at its highest level, and the second LED filament can be powered to achieve the desired luminous flux. Similarly, if the desired luminous flux exceeds the maximum combined luminous flux level of the first and second LED filaments, then the first and second LED filaments can be powered at their highest levels, and a third LED filament can be powered, enabling the LED filament arrangement to achieve the desired luminous flux.

[0038] According to some embodiments, if the desired luminous flux is higher than a threshold corresponding to the maximum flux level of the first LED filament, the controller may be further configured to provide power to the first LED filament and at least one second LED filament at equal levels.

[0039] For example, a first LED filament can be powered to achieve a desired luminous flux level using a single LED filament. If the desired luminous flux exceeds the maximum luminous flux level of the first LED filament, both the first and second LED filaments can be powered at equal (identical) levels, allowing the LED filament assembly to provide the desired luminous flux. If the desired luminous flux exceeds the combined maximum luminous flux of the first and second LED filaments, the first, second, and third LED filaments can be powered at equal levels, allowing the LED filament assembly to provide the desired luminous flux.

[0040] Providing a uniform power level to the illuminated LED filaments can provide more uniform lighting. Furthermore, this solution allows for more even use and wear of the LED filaments, which can result in a longer service life for the LED filament system.

[0041] According to some embodiments, if the desired luminous flux is higher than a first threshold corresponding to the maximum flux level of the first LED filament and lower than a second threshold, the controller can be configured to provide power to the first LED filament at a first level lower than the maximum flux level, and to provide power to the second LED filament at a second level lower than the first level. If the desired luminous flux is higher than the second threshold, the controller can be configured to provide power to the first and second LED filaments at equal levels (or at least substantially equal levels).

[0042] For example, a first LED filament can be powered for a desired luminous flux level achievable using a single LED filament. If the input increases to a luminous flux level corresponding to the maximum luminous flux of a single LED filament, the power supply to the first LED filament can be gradually reduced while a more rapidly increasing power supply is provided to the second LED filament. For an input level corresponding to a second threshold, the first and second LED filaments can be powered at equal levels (or at least substantially equal power levels). For an input corresponding to a flux level higher than the second threshold, the first and second LED filaments can be powered equally.

[0043] The gradual decrease in power supply to the first LED filament combined with the increase in power supply to the second LED filament provides a smoother transition between power supplies of one and two LED filaments. A similar approach can be applied to transitions, for example, between three and four LED filaments, four and five LED filaments, etc.

[0044] According to some embodiments, each LED filament in an LED filament can be arranged in a helical shape with a substantially constant radius. In other words, the distance from the LED filament to the central axis can be substantially constant. The LED filaments according to these embodiments can be formed into cylindrical coils or helical shapes.

[0045] For example, the radii of the spiral shapes can differ by less than 20%. Specifically, the radii of the spiral shapes can differ by less than 10%. More specifically, the radii of the spiral shapes can differ by less than 5%.

[0046] For example, the radius of the spiral shape can be in the range of 1-10 cm. Specifically, the radius of the spiral can be in the range of 2-8 cm. More specifically, the radius of the spiral can be in the range of 3-6 cm.

[0047] According to some embodiments, the LED filament device may include 2 to 8 LED filaments.

[0048] For example, an LED filament device may include 3 to 7 LED filaments. Specifically, an LED filament device may include 3 to 5 LED filaments. More specifically, an LED filament device may include four LED filaments. The four LED filaments in an LED filament device may form a quadruple helix.

[0049] In some embodiments, the shape and size of the LED filaments can be substantially the same.

[0050] For example, LED filaments can have substantially the same width. LED filaments can have substantially the same length. LED filaments can have substantially the same diameter. LED filaments can provide light with substantially the same color temperature. LED filaments can provide light with substantially the same color rendering index (CRI).

[0051] For example, the size of LED filaments can vary by less than 20%. Specifically, the size of LED filaments can vary by less than 10%. More specifically, the size of LED filaments can vary by less than 5%.

[0052] For example, the shape of LED filaments can vary by less than 20%. Specifically, the shape of LED filaments can vary by less than 10%. More specifically, the shape of LED filaments can vary by less than 5%.

[0053] According to a second aspect of this disclosure, a lighting device is provided. The lighting device may include an LED filament system as described above in any embodiment of the first aspect of this disclosure. The lighting device may further include a housing that is at least partially transparent. The housing may enclose at least a plurality of LED filaments of the LED filament system. The lighting device may further include a base on which the housing is mounted. The base may be adapted for connection to a luminaire socket.

[0054] The controller for the LED filament system may be at least partially housed within the base of the lighting fixture. Alternatively or additionally, the controller for the LED filament system may be at least partially housed within the enclosure of the lighting fixture.

[0055] It should be noted that other embodiments using all possible combinations of the features described in the above embodiments are conceivable. Therefore, this disclosure also relates to all possible combinations of the features mentioned herein. Attached Figure Description

[0056] Exemplary embodiments will now be described in more detail with reference to the following figures:

[0057] Figure 1 This is a schematic diagram of an LED filament system according to some embodiments;

[0058] Figure 2 This is a schematic diagram of a controller configured to perform a method according to some embodiments;

[0059] Figure 3 An LED filament system is shown, in which only one LED filament is illuminated;

[0060] Figure 4 An LED filament system is shown, in which all the LED filaments are illuminated;

[0061] Figure 5 It is a graph showing the relationship between input values ​​and luminous flux provided by LED filaments according to some embodiments;

[0062] Figure 6 It is a graph showing the relationship between input values ​​and luminous flux provided by LED filaments according to some embodiments;

[0063] Figure 7 It is a graph showing the relationship between input values ​​and luminous flux provided by LED filaments according to some embodiments;

[0064] Figure 8 This is a schematic diagram of a lighting device according to some embodiments.

[0065] As shown in the figures, the sizes of elements and areas may be exaggerated for illustrative purposes and are therefore provided to illustrate the general structure of the embodiments. The same reference numerals always denote the same elements. Detailed Implementation

[0066] Exemplary embodiments will now be described more fully below with reference to the accompanying drawings, which illustrate the presently preferred embodiments. However, the invention may 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 to fully convey the scope of the invention to those skilled in the art.

[0067] refer to Figure 1 The following describes an LED filament system 100 according to some embodiments.

[0068] The LED filament system includes multiple LED filaments 110a-110c and a controller 120. The multiple LED filaments 110a-110c include three LED filaments: a first LED filament 110a, a second LED filament 110b, and a third LED filament 110c. In the following description, when referring to LED filament 110 (without the suffixes a-c), this description applies to each of the LED filaments 110a-110c. When describing individual LED filaments, the suffixes a-c will be used.

[0069] Each LED filament 110 is arranged in a helical shape. More specifically, each LED filament 110 forms a helical winding around a central axis A. Each helical shape has a (substantially) constant radius r. The radius r is the shortest distance from a point on the LED filament 110 to the central axis A. Furthermore, each helical shape has a (substantially) constant helical pitch p. The helical pitch p is the length of the loop of the helical shape of the LED filament 110 in the direction of the central axis. In other words, it is the distance between the starting point of the loop and the starting point of the continuous loop. Each LED filament 110 has a width w, and their helical shape has a height h. The LED filaments 110 are substantially the same in shape and size.

[0070] LED filaments 110a-110c are arranged around a common central axis A. In other words, LED filaments 110a-110c are coaxial. The positions of LED filaments 110a-110c differ due to rotation around the central axis, resulting in different translational distances t between two adjacent LED filaments 110 along the central axis A. Figure 1 The diagram shows the translational distance t between the first LED filament 110a and the second LED filament 110b. However, the translational distance between each pair of consecutive LED filaments 110 can be (substantially) equal.

[0071] In this embodiment, the LED filament device 105 includes three LED filaments 110. The width w of the LED filaments 110 can be 2.5 mm. The pitch aspect ratio (PAR), i.e., the ratio of the helical pitch to the translational pitch t, ​​can be 3, i.e. For example, the helical pitch p can be nine times the LED filament width w, i.e., p = 9w = 22.5mm. The translational pitch t can be three times the LED filament width w, i.e., t = 3w = 7.5mm.

[0072] In another example, the LED filament assembly may include four LED filaments. The width (w2) of the LED filaments may be 2 mm. PAR may be 4. In this example, the helical pitch may be 12 times the width of the LED filaments, i.e., p2 = 12w2 = 24 mm. The translational pitch may be 3 times the width of the LED filaments, i.e., t2 = 3w2 = 6 mm.

[0073] In the third example, the LED filament assembly may include five LED filaments. The width (W3) of the LED filaments may be 3 mm. PAR may be 5. In this example, the helical pitch may be 10 times the width of the LED filaments, i.e., p3 = 10w3 = 30 mm. The translational pitch may be twice the width of the LED filaments, i.e., t3 = 2w3 = 6 mm.

[0074] It should be understood that LED filaments typically provide LED filament light and include multiple light-emitting diodes (LEDs) arranged in a linear array. Preferably, the LED filament can have a length L and a width W, where L > 5W. LED filaments can be arranged in a straight configuration or a non-straight configuration, such as, for example, a curved configuration, a 2D / 3D spiral, or a helix, such as... Figure 1 As shown in the figure. Preferably, the LED can be arranged on an elongated carrier, such as a substrate, which can be rigid (e.g., made of polymer, glass, quartz, metal or sapphire) or flexible (e.g., made of polymer or metal, such as film or foil).

[0075] When the carrier comprises a first main surface and an opposing second main surface, the LED can be disposed on at least one of these surfaces. The carrier can be reflective or translucent, such as translucent and preferably transparent.

[0076] LED filaments may include a sealant that at least partially covers at least a portion of a plurality of LEDs. The sealant may also at least partially cover at least one of a first or second main surface. The sealant may be a flexible polymeric material, such as, for example, silicone. Furthermore, the LEDs may be arranged to emit LED light of, for example, different colors or spectra. The sealant may include a luminescent material configured to at least partially convert the LED light into converted light. The luminescent material may be a phosphor, such as an inorganic phosphor and / or quantum dots or rods.

[0077] LED filaments can include multiple sub-filaments.

[0078] The controller 120 of the LED filament system 100 is configured to control the power supply to the LED filaments 110a-110c. Specifically, the controller 120 is configured to control the power supply to each of the LED filaments 110a-110c via an electrical connection 121.

[0079] In a typical configuration, the controller can be configured to control the LED filament assembly according to at least two operating modes determined by received inputs. In a first operating mode, the controller can be configured to operate the LED filament assembly such that only one LED filament is activated. In this first operating mode, the lighting device resembles a lamp with a spiral filament. In a second operating mode, the controller can be configured to operate the LED filament assembly such that all LED filaments are activated. In this second operating mode, the lighting device resembles a lamp emitting light from all sides, i.e., a volumetric light emitter.

[0080] refer to Figure 1 and 2 The method 1000 that the controller 120 can be configured to perform according to some embodiments will be described.

[0081] At step 1010, the controller 120 can be configured to receive an input signal representing the desired light flux.

[0082] Based on the desired luminous flux, the controller 120 can be configured at step 1020 to select at least one LED filament 110 to which power is supplied. Depending on the desired luminous flux, one or more LED filaments 110 can be selected.

[0083] At step 1030, the controller 120 may further select the power level of at least one selected LED filament. The selected power level of the first selected LED filament (such as the first LED filament 110a) may differ from the selected power level of the second selected LED filament (such as the second LED filament 110b). However, the selected power levels of two or more selected LED filaments may also be (at least substantially) equal.

[0084] Furthermore, at step 1040, the controller 120 can be configured to supply power to at least one selected LED filament according to the selected power level. The combined luminous flux of the LED filament assembly 105 (including LED filaments 110a-110c, which can be individually illuminated or turned off) can then correspond to the desired luminous flux.

[0085] refer to Figure 3 The dimming of an LED filament system 300 according to some embodiments will be described.

[0086] Figure 3 An LED filament system 300 is shown, and the dimming period of the LED filament device 305 is shown. The LED filament system 300 can be equivalent to the LED filament system 100.

[0087] exist Figure 3In the illustrated scheme, controller 320 supplies power to the LED filaments in a second mode, wherein at least one LED filament is in an off state. Controller 320 supplies power to the first LED filament 310a, illuminating it and thus providing luminous flux. Controller 320 does not supply power to the second LED filament 310b and the third LED filament 310c. Therefore, the second LED filament 310b and the third LED filament 310c are not illuminated and do not provide any luminous flux.

[0088] The luminous flux of the LED filament assembly 305 is therefore provided by the first LED filament 310a. Thus, the luminous flux of the LED filament assembly 305 can be within a range defined by the minimum and maximum flux of the first LED filament 310a. For example, if the input signal received by the controller corresponds to a desired luminous flux below a first limit, the controller can supply power to only one LED filament 310a.

[0089] When only one LED filament 310a is illuminated, the LED filament assembly 305 can have the appearance of a single LED filament.

[0090] refer to Figure 4 The following describes the illumination of an LED filament system 400 according to some embodiments.

[0091] Figure 4 An LED filament system 400 is shown, in which all LED filaments 410a-410c are illuminated and provided with power above a first power level. The LED filament system 400 can be considered equivalent to a reference system. Figure 1 The described LED filament system 100 and / or reference Figure 3 The LED filament system 300 is described.

[0092] exist Figure 4In the illustrated scheme, controller 420 supplies power to LED filaments 410a-410c in a first mode, wherein all LED filaments 410a-410c are supplied with power above a first power level. When controller 420 supplies power to all LED filaments 410a-410c, all LED filaments 410a-410c are illuminated, thus each contributing to the luminous flux. The luminous flux of LED filament assembly 405 includes the luminous flux supplied by all LED filaments 410a-410c. Therefore, the luminous flux of LED filament assembly 405 can be within a range defined by the minimum flux of the combined three LED filaments 410a-410c and the maximum flux of the combined three LED filaments 410a-410c. The controller can, for example, supply power to all LED filaments 410a-410c if the input signal received by the controller corresponds to a desired luminous flux above a second limit.

[0093] Since all LED filaments 410a-410c have power exceeding a first power level, they all emit light exceeding a first light intensity level. When all LED filaments 410a-410c are illuminated and closely arranged together, the emitted light appears to originate from a continuous cylindrical surface when viewed from a distance. Therefore, light and illumination can be uniformly distributed around the LED filament assembly 405.

[0094] refer to Figure 5 The present invention will describe a method for a dimming LED filament system according to some embodiments, such as any LED filament system 100-400 described above with reference to the preceding figures.

[0095] Figure 5 A graph showing the relationship between different input values ​​of LED filament (on the horizontal axis) and the corresponding luminous flux levels (on the vertical axis) according to some embodiments is presented.

[0096] Relationship 530 describes the configuration of the controller for the LED filament system, such as any controller 120-420 described above with reference to the preceding figures. The controller receives signals corresponding to the desired luminous flux level L. d1 L d2 The input values ​​In1 and In2 are used to supply power to one or more LED filaments of the LED filament system, so that the LED filament device provides the desired luminous flux.

[0097] For low input values ​​(such as the first input In1), which corresponds to a flux level below the maximum flux level L of the first LED filament. max The desired luminous flux (such as the first desired luminous flux L) d1The controller is configured to supply power only to the first LED filament upon input. The first LED filament is thus illuminated and provides a first luminous flux 532. The power level of the first LED filament is adapted so that the luminous flux 532 of the first LED filament reaches the desired luminous flux L. d1 .

[0098] If the input is increased (e.g., increased to a second input In2) such that the desired luminous flux increases to the maximum luminous flux level L of the first LED filament. max (e.g., the second desired luminous flux L) d2 The controller then supplies power to the first LED filament to provide a maximum luminous flux 532. The controller further supplies power to the second LED filament, enabling it to provide a second luminous flux 533. The power supplied to the second LED filament is adapted by the controller so that the total luminous flux 531 (formed by the addition or superposition of the first luminous flux 532 and the second luminous flux 533) reaches the desired luminous flux L. d2 .

[0099] With further increases in input, the controller can provide power to the third LED filament, providing a third luminous flux 534, while maintaining the first luminous flux 532 and the second luminous flux 533 at the maximum flux level L. max .

[0100] refer to Figure 6 The present invention will describe a method for a dimming LED filament system according to some embodiments, such as any LED filament system 100-400 described above with reference to the preceding figures.

[0101] Similar to Figure 5 , Figure 6 A graph 630 showing the relationship between different input values ​​of LED filament (on the horizontal axis) and the corresponding luminous flux levels (on the vertical axis) according to some embodiments is shown.

[0102] In this embodiment, as referred to Figure 5 In the described embodiment, the first LED filament is powered by the controller to provide a luminous flux level of 632a up to the maximum luminous flux level Lmax of the LED filament.

[0103] For levels corresponding to higher than the maximum flux level L of LED filaments max The expected luminous flux L d3Input In3 allows the controller to supply power to the first and second LED filaments at equal levels. Therefore, the first LED filament provides a first luminous flux 632b equal to the second luminous flux 633 provided by the second LED filament. The power supply levels of the first and second LED filaments are selected such that the combined luminous flux 631 achieves the desired luminous flux L. d3 .

[0104] refer to Figure 7 The present invention will describe a method for a dimming LED filament system according to some embodiments, such as any LED filament system 100-400 described above with reference to the preceding figures.

[0105] and Figure 5 and 6 similar, Figure 7 A graph showing the relationship 730 between different input values ​​of LED filament (on the horizontal axis) and the corresponding luminous flux levels (on the vertical axis) according to some embodiments is presented.

[0106] For reference Figure 5 and 6 In the described embodiments, the luminous flux level is up to the maximum luminous flux level L. max It is provided by the first LED filament (first luminous flux 732a).

[0107] If the input increases, causing the desired luminous flux to increase to the maximum flux level L... max The controller is configured to supply power to the second LED filament. Within a certain interval, from the input corresponding to the maximum luminous flux to the threshold input In4, the controller reduces the power supply to the first LED filament, causing the first luminous flux 732b to decrease as the input increases. To ensure that the combined luminous flux 731 still increases to provide the desired luminous flux, the power supply to the second LED filament is adjusted so that the second luminous flux 733a increases at a higher rate than the decrease in the first luminous flux 732b.

[0108] At the threshold input In4, the first LED filament and the second LED filament provide the same level of luminous flux. For input values ​​higher than the threshold input In4, the controller is configured to provide equal power supply to the first LED filament and the second LED filament. Therefore, the first LED filament provides a first luminous flux 732c at the same level as the second luminous flux 733b provided by the second LED filament.

[0109] refer to Figure 8 The following describes a lighting device 850 according to some embodiments.

[0110] Lighting device 850 includes LED filament system 800, which includes multiple LED filaments 810 and controller 820. LED filament system 800 can be equivalent to the one mentioned above. Figure 1 -4 describes any one of the LED filament systems 100-400, except that it includes four LED filaments 810, thus forming a quadruple helix. Furthermore, the controller 820 can be configured to execute reference... Figure 2 , 5 Any method described in 6 or 7.

[0111] The lighting device further includes a housing 851 that is at least partially translucent, enclosing the LED filament 810 of the LED filament system 800. Additionally, the lighting device includes a base 852, on which the housing 851 is mounted. A controller 820 is disposed at the base of the lighting device and within the housing 851. However, in other embodiments, the controller 820 may be disposed within the base 852.

[0112] Those skilled in the art will recognize that the present invention is by no means limited to the preferred embodiments described above. Rather, many modifications and variations are possible within the scope of the appended claims.

[0113] Although the features and elements have been described above in specific combinations, each feature or element may be used alone without other features and elements, or in various combinations with or without other features and elements.

[0114] Furthermore, by studying the accompanying drawings, the disclosure, and the appended claims, those skilled in the art can understand and implement variations of the disclosed embodiments in practicing the claimed invention. In the claims, the word "comprising" does not exclude other elements, and the indefinite articles "a" or "an" do not exclude a plurality. The fact that certain features are recited in mutually different dependent claims does not imply that combinations of these features cannot be advantageously used.

Claims

1. A light-emitting diode (LED) filament system, comprising: LED filament assembly, the LED filament assembly comprising a plurality of LED filaments having a width (W), wherein The plurality of LED filaments are intertwined around a common central axis (A), such that each LED filament has a spiral shape. The translational spacing (t) of adjacent LED filaments along the common central axis (A) is different, wherein the translational spacing (t) is in the range of 1 to 5 times the width (W) of one of the LED filaments, and The controller (120) is configured to control the power supply to the LED filaments, such that at least one of the plurality of LED filaments can be controlled individually, wherein... The controller is configured to control the power supply to the LED filaments in a first mode and a second mode. In the first mode, all LED filaments in the LED filaments are in an on state and the controller provides power to the LED filaments at a level higher than a first power level. In the second mode, at least one LED filament in the LED filaments is in an off state. Specifically, for a given translational spacing (t), the LED filament device provides a light distribution corresponding to a uniform light-emitting surface in the first mode, and a light distribution corresponding to at least one light-emitting spiral in the second mode. The controller is configured as follows: Receive the input signal representing the desired light flux; At least one LED filament is selected to provide power to the desired luminous flux; Select the power level of the at least one selected LED filament to provide the desired luminous flux; and Power is supplied to the selected at least one LED filament according to the selected power level, and Where the desired luminous flux (L) D ) lower than the first limit (L) max The controller is configured to supply power to only one LED filament, and if the desired luminous flux is higher than a second limit, the controller is configured to supply power to all LED filaments of the LED filament assembly.

2. The LED filament system according to claim 1, wherein each LED filament is arranged in a helical shape having a substantially constant helical pitch (p).

3. The LED filament system according to claim 2, wherein the helical pitch (p) is in the range of 8 to 20 times the width (W) of one of the LED filaments.

4. The LED filament system according to any one of the preceding claims, wherein the width (W) is in the range of 1 mm to 4 mm.

5. The LED filament system according to any one of claims 1 to 3, wherein the controller is further configured to, if the desired luminous flux is higher than a threshold corresponding to the maximum flux level of the first LED filament, then: Provide the first LED filament with power corresponding to the maximum flux level; and Power is supplied to the second LED filament to achieve the desired luminous flux.

6. The LED filament system according to any one of claims 1 to 3, wherein the controller is further configured to, if the desired luminous flux is higher than a threshold corresponding to the maximum luminous flux level of the first LED filament: Power is supplied to the first LED filament and at least one second LED filament at equal levels.

7. The LED filament system according to any one of claims 1 to 3, wherein the controller is further configured to: If the desired luminous flux is higher than a first threshold corresponding to the maximum flux level of the first LED filament and lower than a second threshold, power is supplied to the first LED filament at a level lower than the maximum flux level, and power is supplied to the second LED filament at a level lower than the first level; and If the desired luminous flux is higher than the second threshold, power is supplied to the first LED filament and the second LED filament at an equal level.

8. The LED filament system according to any one of claims 1 to 3, wherein each LED filament is arranged in a helical shape having a substantially constant radius (r).

9. The LED filament system according to any one of claims 1 to 3, wherein the LED filament device comprises 2 to 8 LED filaments.

10. A lighting device (850), comprising: The LED filament system as defined in any one of claims 1 to 3; A partially transparent enclosure (851) at least encloses the plurality of LED filaments of the LED filament assembly; and A base (852), on which the housing is mounted, wherein the base is adapted to be connected to a lamp socket.

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