Beam shaping for spiral LED filament systems

Abstract

This disclosure relates to a light-emitting diode (LED) filament system (770) including an LED filament (100) and a controller (771). The LED filament includes a carrier (120) arranged in a spiral shape formed by continuous loops (250). The LED filament also includes a plurality of LEDs (110) arranged in a linear array on one side of the carrier. The LEDs are arranged along the carrier in segments (140a-f), each segment having a position along the spiral carrier. The controller is configured to control the power supply to a segment or a group of segments of the LED filament. The controller is adapted to control a segment based on the position of the segment, or to control a group of segments based on the position of the group of segments.

Description

Technical Field

[0001] This disclosure generally relates to the field of solid-state lighting. Specifically, this disclosure relates to a light-emitting (LED) filament system comprising a spiral LED filament and a controller, the spiral LED filament comprising a plurality of LEDs arranged in sections. Background Technology

[0002] Incandescent lamps are being rapidly replaced by lighting solutions based on light-emitting diodes (LEDs). Solid-state lighting devices offer many advantages over their incandescent, fluorescent, and gas discharge-based counterparts. For example, they can provide increased lifespan, reduced power consumption, and higher efficiency. Solid-state lighting devices, such as LEDs, are used in a wide range of lighting applications.

[0003] 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.

[0004] EP3336411 discloses a substrate for LED packaging, an LED package, and an LED bulb. The substrate is elongated, with electrode leads at at least one end. The electrode leads are connected to the substrate via connecting elements and / or connecting materials, wherein the substrate has at least one opening arranged along its length. The LED package includes a substrate on which a plurality of LED chips are disposed, and the plurality of LED chips are connected in series and / or in parallel via connecting wires. The LED bulb of the present invention has an LED package. Summary of the Invention

[0005] A general objective of this invention is to provide a more versatile LED-based lighting solution. Specifically, it is desirable to provide an LED filament system that allows for customizable light distribution.

[0006] Therefore, the object of the present invention is to satisfy at least some of the above objectives and to provide improved LED-based lighting.

[0007] 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.

[0008] According to a first aspect of the invention, a light-emitting diode (LED) filament system is provided. The LED filament system includes an LED filament and a controller. The LED filament includes a carrier arranged in a helical shape, the helical shape being formed by continuous loops. A plurality of LEDs are arranged in a linear array on one side of the carrier. Specifically, the LEDs are arranged in segments, each segment having a position along the helical shape of the carrier. The controller is configured to control the power supply to a segment of the LED filament or to a group of segments of the LED filament. The controller is also adapted to control the power supply to a segment based on its position, or to control the power supply to a group of segments based on the position of a group of segments.

[0009] The carrier is formed into a spiral shape by continuously winding around a central axis in a curved manner. The loop is formed by winding a portion of the carrier around the central axis 360 degrees. The first end portion (starting portion) of the loop can be separated from the second end portion (end portion) of the loop in the direction along the central axis, that is, the first end portion and the second end portion are located at two different positions (heights) along the length of the spiral.

[0010] Multiple LEDs are arranged in a linear array on one side of the carrier. For example, the LEDs can be arranged in a single row along the carrier. Alternatively, the LEDs can be arranged in two or more rows along the carrier. When the LEDs are arranged in multiple rows along the carrier, these rows can be at least substantially parallel. The LEDs can be arranged with a substantially constant spacing (the distance between consecutive LEDs).

[0011] It should be understood that LEDs can be arranged on several sides of the carrier. For example, the LED filament may include a second plurality of LEDs arranged on the second and opposite sides of the carrier.

[0012] Lighting fixtures incorporating spiral LED filaments are highly appreciated for their decorative appearance. Spiral LED filaments can be configured as individually controllable sections (i.e., sections whose power supply can be individually controlled by a controller) or as a group of sections, allowing for customizable light distribution.

[0013] According to one embodiment, the LEDs in a segment can be controlled by a controller to emit light with variable intensity.

[0014] For example, the controller can control one segment to provide a first intensity I1 and control another segment to provide a second intensity I2. The first intensity I1 can be at least twice the second intensity I2 (I1 > 2I2). Specifically, the first intensity I1 can be at least three times the second intensity I2 (I1 > 3I2). More specifically, the first intensity I1 can be at least four times the second intensity I2 (I1 > 4I2).

[0015] Many different types of LEDs can be used to provide segments with variable intensities. For example, multiple LEDs may include LEDs configured to emit blue light. Alternatively or additionally, multiple LEDs may include LEDs configured to emit ultraviolet (UV) light. To enable the LED filament to provide white light, the LED may be covered with a sealant comprising a wavelength conversion material (e.g., a luminescent material). Alternatively, the LED may be individually covered with a wavelength conversion material.

[0016] Wavelength conversion materials can absorb at least some of the light emitted by an LED, and the emitted light has different wavelengths. The type of LED and wavelength conversion material can be selected for the LED filament to provide light with a desired color or color temperature. The sealant covering at least the LED can include a light-scattering material. Light-scattering materials can include, for example, particles of barium sulfate (BaSO4), alumina (III) (Al2O3), and / or titanium dioxide (TiO2).

[0017] LED filaments have sections in which LEDs can be controlled to emit light with variable intensities. The LED filaments can provide the possibility of beam scanning, i.e., the illumination effect where consecutive sections are illuminated with higher intensity. This can provide the appearance of a beam propagating around the LED filament.

[0018] According to some embodiments, the LEDs in a section can be controlled by a controller to emit light with variable colors.

[0019] Various types of LEDs can be used to provide segments with variable colors. For example, multiple LEDs may include red, green, and blue LEDs. Light from red, green, and blue LEDs can be combined with different intensities to form a variety of colors. Alternatively, multiple LEDs may include LEDs that provide white light with different color temperatures. For example, multiple LEDs may include a first plurality of LEDs and a second plurality of LEDs, the first plurality of LEDs being arranged to provide white light with a first, warmer, white tint (e.g., light with a lower correlated color temperature), and the second plurality of LEDs being arranged to provide white light with a second, cooler, white tint (e.g., light with a higher correlated color temperature).

[0020] The power supply to different types of LEDs can be controllable, allowing the color and / or color temperature of the light emitted by the segment to be adapted. Such embodiments can provide LED filaments that allow for different color patterns. For example, such embodiments can allow for color gradients (gradual transitions between colors) in the light provided by the LED filaments.

[0021] According to some embodiments, the position of the segment can be defined as height and angle. The height of the segment (i.e., the position of the segment along the height of the spiral carrier) can be related to the distance from the central axis (or longitudinal axis) of the spiral to the end portion of the LED filament. The angle of the segment (i.e., the position of the segment along the circumference of the spiral carrier) can be related to the position of the segment along the ring relative to the starting point of the ring.

[0022] The angle of a segment can be the angle formed between the ray drawn from the starting point of the ring to the central axis and the ray drawn from the starting point of the segment to the central axis.

[0023] According to some embodiments, the spiral loop may include N segments. The number of segments N in the loop may be in the range of 2 to 8.

[0024] For example, the number of segments N in a ring can be in the range of 3 to 7. More specifically, the number N can be in the range of 4 to 6.

[0025] For embodiments where each ring comprises more than one segment, the light distribution of the LED filament can be controlled asymmetrically. For example, a segment corresponding to one half of each ring can be illuminated with a higher intensity and / or a different color than the other half, as long as the illumination on one side of the LED filament differs from the illumination on the other side. More segments within the ring can provide greater variability in the light distribution of the LED filament.

[0026] For example, in embodiments where N is at least 2, a segment can be controlled (by a controller) to provide a first intensity I1, and another segment can be controlled to provide a second intensity I2. The difference between the first intensity I1 and the second intensity I2 can be at least 40%.

[0027] In embodiments where N is at least 4, two sections arranged on opposite sides of the ring (e.g., at the front and rear of the LED filament) can be controlled (by a controller) to provide higher intensity than other sections of the ring.

[0028] In embodiments where each ring comprises a segment, these rings can be individually controllable or arranged in a controllable group. Such embodiments can provide different light distributions along the direction of the central axis. For example, the controller can individually control the power supply to the rings, such that the intensity and / or color of one ring differs from the intensity and / or color of the other rings.

[0029] Furthermore, different embodiments may include different numbers of rings. In embodiments including at least four rings, a segment of the ring located at one end of the LED filament can be controlled to provide higher intensity than a segment of the ring located at the other end of the LED filament.

[0030] Controlling an LED filament so that individual sections are illuminated and turned off according to a defined pattern can be called beam shaping. LED filaments can be used in conjunction with reflectors to provide beam shaping.

[0031] According to some embodiments, the segment may include at least a first group of segments and a second group of segments. The first group of segments and the second group of segments may be arranged in a repeating manner along the carrier.

[0032] For example, in an embodiment that includes a first group of segments and a second group of segments, the first group of segments and the second group of segments may be arranged alternately along the carrier.

[0033] The segments in the first group can differ from those in the second group. The segments in the first group and the segments in the second group can, for example, provide light with different color temperatures.

[0034] For example, the segments in the first group can have a thicker sealant layer than the segments in the second group. A thicker sealant layer, including wavelength conversion material, can provide that a larger portion of the light emitted by the LED is converted (i.e., absorbed by the wavelength conversion material and re-emitted at a different wavelength).

[0035] Alternatively or additionally, the segments of the first group may include wavelength conversion materials of a different type than those of the segments of the second group, the wavelength conversion materials being disposed within a sealant that at least covers the LEDs or covering the LEDs separately.

[0036] As a third option, the segments of the first group may include a higher concentration of wavelength conversion material than the segments of the second group, the wavelength conversion material being arranged in a sealant that at least covers the LED or covering the LED separately.

[0037] In addition, the segments in the first group may include LEDs of a different type than those in the segments of the second group.

[0038] It should be understood that embodiments including the first group of segments and the second group of segments may further include more groups of segments, such as a third group of segments. In such embodiments, segments from different groups may be arranged in a repeating manner along the carrier. For example, the segments may be arranged as a pattern, wherein segments from the second group follow segments from the first group, segments from the third group follow segments from the second group, and the pattern repeats along the carrier.

[0039] According to some embodiments, each loop of a spiral LED filament may include the same number of segments.

[0040] According to some embodiments, each ring may include N segments. Furthermore, the N boundaries between the N segments of the ring may be aligned with the N boundaries between the N segments of the continuous ring along the height of the helical carrier.

[0041] In embodiments where sections are aligned along the height of the spiral carrier (or along the central axis of the spiral), advanced patterns can be achieved in the illumination of LED filaments.

[0042] In an embodiment where each ring comprises two segments (a first segment and a second segment), the first segments of the ring can be aligned (i.e., placed overlapping each other in a spiral arrangement of segments), and the second segments of the ring can be aligned. In such an embodiment, all first segments can be illuminated, followed by all second segments. When the second segments are illuminated, the first segments can be turned off. In such an embodiment, the first segments can form a first group, the second segments can form a second group, and the third segments can form a third group.

[0043] In embodiments where the number of segments N within each ring is greater than or equal to 3, the first segments of the ring may be aligned, the second segments of the ring may be aligned, the third segments of the ring may be aligned, and so on. In such embodiments, all first segments may be illuminated during a first time period, followed by the illumination of all second segments during a second time period (after the first time period), followed by the illumination of the third segments, and so on. When the second segments are illuminated, the first segments may be turned off. When the third segment is illuminated, the first and / or second segments may be turned off, and so on.

[0044] Continuous illumination and de-illumination of aligned segments of a continuous group can result in beam scanning.

[0045] According to some embodiments, the radius of the spiral ring can vary along the height of the spiral carrier (i.e., along the central axis).

[0046] For example, the ring located at the end portion of the LED filament can have a smaller radius than the ring located in the middle of the LED filament (i.e., between the aforementioned end portions), thereby giving the LED filament a barrel shape.

[0047] Alternatively, the loops at the ends of the LED filament can have a larger radius than the loops between the ends. In such an embodiment, the spiral filament can be approximately hourglass-shaped or diabolo-shaped.

[0048] In another option, the radius of the ring continuously increases / decreases from one end of the spiral to the other.

[0049] According to some embodiments, the length of a segment in a ring with a smaller radius can be shorter than the length of a segment in a ring with a larger radius.

[0050] For example, the length of segments in different rings can be adjusted so that each ring includes the same number of segments.

[0051] In embodiments where all rings have the same radius, these segments may have the same length.

[0052] According to some embodiments, each segment may include at least two LEDs.

[0053] In embodiments where each segment includes more than one LED (i.e., at least two LEDs), each segment can provide greater throughput.

[0054] In a section that includes only one individually controllable LED, the LED can be effectively controlled individually.

[0055] Alternatively, in embodiments where the length of the segments can vary, some segments may include one LED, while other segments may include more than one LED.

[0056] According to some embodiments, the LEDs in the section can be connected in series.

[0057] The embodiment of connecting LEDs in series within a section is easier to manufacture because it requires a less complex electrical connection system. Furthermore, if the LEDs within a section are connected in series, the intensity of the entire section can be controlled together.

[0058] Alternatively, the LEDs can be individually controllable, or different groups of LEDs within a segment can be individually controllable. For example, in an embodiment where the segment includes LEDs providing different colors of light, LEDs providing the same color within the segment can be connected in series. In such an embodiment, the color of the segment can be controlled by controlling the power supply to the LEDs of different colors within the segment and the intensity of the emitted light.

[0059] For example, within a section, some LEDs can be connected in series and some LEDs can be connected in parallel. It should be understood that the power supply to the section (in which LEDs can be connected in series and / or parallel) can be controlled by a controller.

[0060] In embodiments where the LEDs within a section are individually controllable, the lighting pattern can also be adapted to each section.

[0061] According to some embodiments, the controller can be configured to control the power supply to a first segment or a first group of segments, which is different from the power supply to a second segment or a second group of segments.

[0062] According to some embodiments, the controller can be configured to control the power supply to a section of the LED filament so that the luminous flux of the LED filament remains substantially constant over time.

[0063] In such an embodiment, the LED filament can provide the same amount of illumination over time, but the direction and / or pattern of the illumination can vary. This lighting effect may be particularly desirable for effective lighting of an event.

[0064] It should be understood that the luminous flux may not be constant each time an LED filament system is used. Instead, "constant over time" means constant over a certain period of time. For example, the amount of luminous flux can be a setting provided by the controller.

[0065] Alternatively or additionally, similar settings can be used for color. The controller can be configured to provide a constant total amount of light with different wavelengths (colors), wherein the direction of emitting light with a specific color can vary.

[0066] According to some embodiments, the controller can be configured to control the power supply to a segment or a group of segments of an LED filament based on the desired light emission direction.

[0067] For example, the controller can control the power supply to a segment or a group of segments, such that a segment emitting light in a desired direction is turned on, while other segments are turned off. The light emission direction of a segment can depend on the position of the segment. For example, in an embodiment where the LED is arranged on a side of the carrier away from the central axis of the spiral, the LED can emit light in a direction away from the central axis.

[0068] For example, the controller can be adapted to control / address segments based on the height and angle of the LED filament segments. In such an embodiment, segments at all heights within a certain angular range, i.e., segments located at the same position but at different heights along the circumference of the spiral carrier, can be illuminated with a specific lighting pattern.

[0069] According to a second aspect of this disclosure, a lighting device is provided. The lighting device may include an LED filament system as described with reference to any embodiment of the second aspect. The lighting device may also include a housing that is at least partially translucent. The housing may at least partially surround at least one LED filament of the LED filament system. The lighting device may further include a base on which the housing can be mounted. The base may be further adapted for connection to a luminaire socket.

[0070] Lighting equipment can be LED incandescent lamps. Light emitted by an LED filament can be called LED light. Light emitted by an LED, absorbed by a wavelength conversion material, and re-emitted at a different wavelength can be called converted light. Therefore, light provided by an LED filament (LED filament light) can include a combination of LED light and / or converted light. A housing that is at least partially transparent is suitable for transmitting LED filament light. Therefore, an LED filament lamp can provide LED filament light, which in turn can include LED filament light.

[0071] The lighting fixture may have a longitudinal axis. The longitudinal axis may extend substantially perpendicular to the surface of the substrate, for example.

[0072] The central axis of a spiral LED filament can be substantially parallel to the longitudinal axis of the lighting device.

[0073] Alternatively, the central axis of the spiral LED filament can be substantially perpendicular to the longitudinal axis of the lighting device.

[0074] 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

[0075] Exemplary embodiments will now be described in more detail with reference to the following figures:

[0076] Figure 1 A plan view and a side view of an LED filament according to some embodiments are shown;

[0077] Figure 2 A side view of an LED filament arranged in a spiral shape of continuous loops according to some embodiments is shown, as well as a plan view of the loops;

[0078] Figure 3 A side view of an LED filament arranged in a spiral shape with alternating first and second segments according to some embodiments is shown, as well as a plan view of the loop of the LED filament.

[0079] Figure 4 A side view of an LED filament arranged in a spiral shape according to some embodiments is shown, wherein the radius of the loop varies along the height of the spiral, and a side view of the LED filament in an extended state is also shown.

[0080] Figure 5 A section of an LED filament is shown according to some embodiments, wherein the LEDs are electrically connected in series;

[0081] Figure 6 A section of an LED filament is shown according to some embodiments, wherein each type of LED is electrically connected in series;

[0082] Figure 7 This is a schematic diagram of an LED filament system according to some embodiments;

[0083] Figure 8 This is a schematic diagram of a lighting device according to some embodiments.

[0084] 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

[0085] 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 to thoroughly and completely convey the scope of the invention to those skilled in the art.

[0086] refer to Figure 1 The following describes an LED filament 100 according to some embodiments.

[0087] Figure 1 A plan view of the LED filament 100 and a side view of the same LED filament 100 are shown. Figure 1 In the illustration, for the purpose of explanation, the LED filament 100 extends in a straight line.

[0088] The LED filament 100 includes a carrier 120. The carrier 120 can be flexible, allowing it to be wound into a spiral shape. However, a rigid carrier that can be shaped into a spiral can also be used. A plurality of LEDs 110 are arranged in a linear array on one side of the carrier 120. Specifically, the LEDs 110 are arranged in a single row along the carrier 120. The LEDs 110 are arranged in sections 140a-f. Sections 140a-f are individually controllable because the power supply to the LEDs 110 within each section 140a-f can be controlled by a controller. In other words, one section of 140a-f can be controlled separately from the other sections, such that, for example, the power supplied to the LEDs in the first section 140a can be different from the power supplied to the LEDs in the second section 140b.

[0089] Furthermore, as shown in the side view, the LED filament 100 includes a sealant 130. The sealant 130 covers a plurality of LEDs 120, and the sides of the carrier 120 on which LEDs 110 are disposed are also covered. The sealant 130 may include a wavelength conversion material and / or a light scattering material. In embodiments where the sealant 130 includes a wavelength conversion material, the wavelength conversion material itself may have a light scattering effect.

[0090] The color of the light emitted by the LED filament 100 may be affected by the type of LED 110 and the type of sealant 120 used for the LED filament.

[0091] For example, the LED filament 100 can be arranged to emit white light with a single color temperature, for which the intensity of different segments 140a-f can be controlled. In such an embodiment, the LED 110 can be an LED suitable for emitting blue light and / or UV light, which can provide high efficiency. The sealant 120 can include wavelength conversion materials, such as yellow and red phosphors. The light converted by the phosphor can co-form white light with the unconverted light from the LED. Alternatively, the LED 110 can include a combination of blue and red LEDs. In this embodiment, the wavelength conversion material can partially convert blue light to form white light.

[0092] Alternatively, the LED filament 100 can be arranged to emit white light with variable color temperature and / or variable intensity. In this embodiment, the LED 110 may include at least two different types of LEDs. A first type of LED may be arranged to emit white light with a first color temperature, and a second type of LED may be arranged to emit white light with a second color temperature different from the first color temperature.

[0093] Furthermore, to provide intensity and / or color control, LED 110 may include a combination of red, green, and blue LEDs. In such embodiments, the sealant may include a light-scattering material.

[0094] It should be understood that LED filaments typically provide LED filament light and comprise multiple light-emitting diodes (LEDs) arranged in a linear array. Preferably, the LED filament has a length LF and a width W, where LF > 5W. The LED filament can be arranged in a non-linear configuration, such as a curved configuration, a 2D / 3D spiral, or a helix. Preferably, the LEDs are 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 a film or foil).

[0095] In the case where the carrier includes a first main surface and an opposing second main surface, the LED is disposed on at least one of these surfaces. The carrier can be reflective or translucent, for example, translucent or transparent. Specifically, the carrier can be translucent.

[0096] 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 silicone. Furthermore, the LEDs may be arranged to emit LED light, 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.

[0097] LED filaments can include multiple sub-filaments.

[0098] Reference Figure 2 The following describes an LED filament 200 arranged in a spiral shape according to some embodiments.

[0099] Figure 2 An illustration shows an LED filament 200 arranged in a spiral pattern. The LED filament 200 can be considered equivalent to the reference... Figure 1 The described LED filament 100 may be arranged in a different shape. The LED filament 200 may comprise a rigid or flexible carrier, as long as it can be shaped into a helix. The helix extends along a central axis A. For illustrative purposes, the LED filament 200 is depicted as having a uniform cylindrical shape. This appearance can be achieved by embedding the LED and the carrier in a sealant, such that the sealant covers all sides of the carrier.

[0100] The LED filament 200 can be arranged such that the surface of the carrier on which the LEDs are disposed is opposite to the central axis A. Furthermore, the LEDs can be arranged such that the light-emitting surface of each LED is opposite to the central axis A. Therefore, most of the light emitted by the LED filament 200 can be directed away from the LED filament 200.

[0101] In embodiments where the carrier is (partially) translucent, the LED filament 200 can be arranged such that 60-90% of the light from the LED filament is emitted in a direction away from the central axis A. For example, the LED filament 200 can be arranged such that the surface of the carrier on which the LEDs are disposed and / or the light-emitting surface of each LED faces away from the central axis A. Alternatively or additionally, a semi-reflective carrier can be used.

[0102] The LED filament 200 is wound in a continuous loop 250 around the central axis A with a substantially constant radius r. The loop 250 is also shown from above. The loop 250 is formed by a portion of the LED filament 200 wound 360 degrees around the central axis A.

[0103] The spiral LED filament has a height H, which corresponds to the distance along the central axis from the first end portion or first terminal 201 of the LED filament 200 to the second end portion or second terminal 202 of the LED filament 200 (opposite to the first end 201).

[0104] A segment of section 240 is also shown. The position of section 240 can be defined or described by the height h and angle θ of section 240. The height h of the segment is the distance from the first end portion 201 to section 240 along the central axis. The angle θ of section 240 is the angle formed between the ray drawn from the starting point 251 of ring 250 to the central axis A and the ray drawn from the starting point of section 240 to the central axis A.

[0105] Reference Figure 3 The present invention will describe an LED filament comprising a first group of segments and a second group of segments according to some embodiments.

[0106] Figure 3 A side view of the LED filament 300 and a plan view of one of the rings 350 of the LED filament 300 are shown. The LED filament 300 can be equivalent to reference... Figure 2 The described LED filament 200 includes a first group of segments 340a-b and a second group of segments 341a-b. The first group of segments 340a-b and the second group of segments 341a-b are arranged alternately along the LED filament 300. Specifically, each ring 350 includes two segments 340a-b from the first group and two segments 341a-b from the second group. Furthermore, the segments of different rings are aligned in a direction along the central axis of the spiral LED filament 300. For example, one segment of the first group of segments 340a in ring 350 is aligned with a segment of the first group in each of the other rings. In the figure, the first group of segments 340a in ring 350 is aligned with a segment of the first group in each of the other rings.

[0107] The LED filament 300 can be controlled to perform beam scanning. This illumination effect can be achieved through continuous illumination segments arranged in a continuous angular range. For example, initially, the first segment 340a in each ring can be illuminated. The other segments 341a, 340b, and 341b can be turned off, or they can be illuminated with a lower intensity than the first segment 340a. In this first embodiment, most of the light emitted by the LED filament 300 will be directed in the direction of the first segment 340a, for example, within a range from 0 to 90 degrees.

[0108] Secondly, the second adjacent segment 341a in each ring can be illuminated. The other sections 340a, 340b, and 341b can be turned off again, or illuminated with a lower intensity than the second segment 341a. Most of the light emitted by the LED filament 300 will now be directed in the direction of the second segment 341a, for example, within a range of 90 to 180 degrees.

[0109] Next, the third segment 340b in each ring, adjacent to the second segment 341a, can be illuminated, while the other segments are turned off or dimmed. Then, most of the light emitted by the LED filament 300 will be directed toward the third segment 340b, for example, within a range of 180 to 270 degrees.

[0110] Finally, the fourth segment 341b in each ring, adjacent to the third segment 340b, can be illuminated, while the other segments are turned off or dimmed (i.e., illuminated with lower intensity). Then, most of the light emitted by the LED filament 300 will be directed toward the fourth segment 341b, for example, within a range of 270 to 360 degrees.

[0111] If this process is repeated, the light beam emitted by the LED filament can be perceived as sweeping around the LED filament 300. During this process, the controller can be adapted to control the illumination of the section such that the luminous flux of the LED filament 300 remains substantially constant over time as the light beam sweeps around the LED filament.

[0112] The first group of segments 340a-b can be further configured to emit light with a different color temperature than the second group of segments 341a-b. In such an embodiment, the color temperature of the light emitted by the LED filament can be adjusted by using the intensity of the light emitted by the first group of segments 340a-b and the second group of segments 341a-b.

[0113] refer to Figure 4 For example, an LED filament 400 will be described according to some implementations, wherein the radius of the ring varies along the height of the LED filament.

[0114] Figure 4 A side view of an LED filament 400 having a spiral shape is shown, as well as a side view of the same LED filament 400 in an extended configuration. The LED filament 400 can be equivalent to the reference... Figure 2 The LED filament 200 described, except that the radius r of the ring varies along the height H of the LED filament 400.

[0115] The LED filament 400 is wound around the central axis A. The radius r of the loop increases along the height h from the first end portion 401 of the LED filament 400 towards the central portion 403. The radius r of the loop decreases again along the height H from the central portion 403 of the LED filament 400 towards the second end portion 402.

[0116] In an extended version of the LED filament 400, different segments 441, 442, and 443 of the LED filament 400 are shown. Segment 441 has a shorter length near the end portions 401 and 402. The length of the segments increases towards the central portion 403 of the LED filament. Specifically, each loop of the LED filament 400 comprises two segments of equal length.

[0117] refer to Figure 5 The section 541 of the LED filament 500 according to some embodiments will be described, wherein the LEDs 112 are connected in series.

[0118] Figure 5 This is an illustration of a portion of LED filament 500. LED filament 500 may be equivalent to any of the LED filaments 100-400 described with reference to the foregoing figures.

[0119] Figure 5 A segment 541 of an LED filament 500 comprising four LEDs 112 is shown. LEDs 111 from the left side of segment 541 and LEDs 113 from the right side of segment 541 are also shown. The LEDs 112 are connected in series via a first electrical connector 562. Therefore, the intensity of the LEDs 112 in segment 541 can be controlled simultaneously by controlling the power supply to the LEDs 112 via the first electrical connector 561. Furthermore, LEDs 111 and 113 from adjacent segments are connected in series via a second electrical connector 562.

[0120] refer to Figure 6 The section 640 will describe an LED filament including a red LED 610a, a green LED 610b, and a blue LED 610c, according to some embodiments.

[0121] Figure 6 Section 640 of the LED filament is shown. The LED filament can be equivalent to the reference. Figure 1-4 The LED filaments described are any one of 100-400, except that it includes red, green and blue LEDs.

[0122] In segment 640, two red LEDs 610a, two green LEDs 610b, and two blue LEDs 610c are arranged in a single row on substrate 120. The two red LEDs 610a are connected in series via a first electrical connector 660a. The two green LEDs 610b are connected in series via a second electrical connector 660b. The two blue LEDs 610c are connected in series via a third electrical connector 660c. Connecting LEDs of the same type (color) in series allows the intensity of the LEDs to be controlled simultaneously. Therefore, the power supply to the red LEDs 610a, green LEDs 610b, and blue LEDs 610c can be controlled separately. By controlling the power supply to the LEDs, the intensity of the light emitted by the LEDs can be controlled. By controlling the intensity ratio between LEDs of different types (colors), the color of the combined light emitted by segment 641 can be controlled.

[0123] refer to Figure 7 The following describes an LED filament system according to some embodiments.

[0124] Figure 7 An LED filament system 770 is shown, comprising an LED filament 700 and a controller 771. The LED filament 700 may be equivalent to any LED filament described above with reference to the preceding figures. The controller 771 is connected to the LED filament 700 via an electrical connection 772.

[0125] Each loop of the spiral LED filament 700 includes a first segment 740 and a second segment 741. The first segments 740 of different loops are aligned along the height of the LED filament 700, and the second segments 741 of different loops are aligned along the height of the LED filament. A controller 771 is configured to control the power supply to segments 740 and 741. In the illustration, the controller 771 controls the first segment 740 to be illuminated and the second segment 741 to be de-illuminated (not illuminated). As a result, most of the light emitted by the LED filament is distributed to one side of the LED filament (e.g., within a range of 0 to 180 degrees).

[0126] Controller 771 can first control all first segments 741 (which are aligned) to be illuminated. Next, controller 771 can control all second segments 742 to be illuminated. When the second segments 742 are illuminated, the first segments 741 can be turned off. This control mode can be repeated.

[0127] The first segment 741 can form the first group of segments, and the second segment 742 can form the second group of segments.

[0128] refer to Figure 8 The following describes a lighting device 880 according to some embodiments.

[0129] Figure 8This is a side view of a lighting device 880 according to some embodiments. The lighting device 880 includes an LED filament system 870, which may be equivalent to the referenced... Figure 7 The described LED filament system 770. The lighting device also includes a housing 870 that is at least partially transparent. The LED filament 800 of the LED filament system 870 is arranged within the housing 881. In other words, the housing 881 surrounds the LED filament 800.

[0130] Furthermore, the lighting device includes a base 882 on which a housing 881 is mounted. In this embodiment, the controller 871 of the LED filament system 870 is disposed on the base 882 and within the housing 881. In other embodiments, the controller 871 may be disposed within the base 882. An electrical connector 872 connects the LED filament 800 to the controller 871.

[0131] The base 882 is adapted to be connected to a lighting socket. Specifically, the base 882 is adapted to be connected to an Edison-type socket.

[0132] A retaining structure 883 is also mounted on the base 882, which is used to hold the LED filament 800 in the proper position within the lighting device 880. The central axis of the spiral LED filament 800 is arranged parallel to the longitudinal axis of the lighting device 880.

[0133] 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.

[0134] 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.

[0135] 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 article "a" or "an" does not exclude multiple elements. 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 (770), comprising: LED filament (100) includes: The carrier (120) is arranged in a spiral shape formed by a plurality of continuous rings (250); Multiple LEDs (110) are arranged in a linear array on one side of the carrier; The LEDs are arranged in multiple segments (140a-f) along the carrier, and each segment has a position along the spiral shape of the carrier; and A controller (771) is configured to control the power supply to a section of the LED filament or to a group of sections of the LED filament; The controller described herein is adapted to: Control the segment based on its location, or The group of segments is controlled based on their location. The position of the segment is defined by a height and an angle, the height being related to the distance from the end portion of the LED filament along the central axis (A) of the spiral shape to the segment, and the angle being related to the position of the segment along the ring relative to the starting point of the ring. Each ring of the LED filament comprises N segments, and the N boundaries between the N segments of the ring are aligned with the height of the spiral carrier along the N boundaries between the N segments of the continuous ring.

2. The LED filament system of claim 1, wherein the LED segments are controllable by the controller to emit light with variable intensity.

3. The LED filament system according to any one of claims 1-2, wherein the LED segments are controllable by the controller to emit light with variable colors.

4. The LED filament system according to any one of claims 1-2, wherein the spiral ring comprises N segments, the number N being in the range of 2-8.

5. The LED filament system according to any one of claims 1-2, wherein the segment comprises at least a first group of segments (340a-b) and a second group of segments (341a-b), wherein the first group of segments and the second group of segments are arranged in a repeating manner along the carrier.

6. The LED filament system according to any one of claims 1-2, wherein the radius of the ring of the spiral varies along the height of the spiral.

7. The LED filament system of claim 6, wherein the length of the segment in the ring with the smaller radius is shorter than the length of the segment in the ring with the larger radius.

8. The LED filament system according to any one of claims 1-2 and 7, wherein each segment comprises at least two LEDs.

9. The LED filament system according to any one of claims 1-2 and 7, wherein the LEDs (112) in the sections are connected in series.

10. The LED filament system according to any one of claims 1-2 and 7, wherein the controller is configured to control the power supply to the first section or the power supply to the first group of sections differently than the power supply to the second section or the power supply to the second group of sections.

11. The LED filament system according to any one of claims 1-2 and 7, wherein the controller is configured to control the power supply of the segment or group of segments of the LED filament such that the luminous flux of the LED filament is substantially constant over time.

12. The LED filament system according to any one of claims 1-2 and 7, wherein the controller is configured to control the power supply of the segment or group of segments of the LED filament based on a desired light emission direction, such that the segment emitting light in the desired direction is turned on and the other segments are turned off.

13. A lighting device (880), comprising: The LED filament system (870) as defined in any one of the preceding claims; A housing (881) that is at least partially transparent to light, which at least partially surrounds at least the LED filament of the LED filament system; A base (882) on which the housing is mounted, the base being adapted to be connected to a lamp socket.

Images