Polarized LED filament lamp

Abstract

The field of the invention is LED filament lamps 7 for illumination, in which at least one LED filament lamp 7 is configured to emit polarized light. The LED filament lamp 7 has at least one LED filament 1 and an enclosed volume V having an envelope 10 including a light exit window, inside which the LED filament 1 is arranged. 1 , 1 2 has a plurality of LEDs 3 arranged on a filament support 2. At least one polarizer 5 is arranged relative to the LED filament 1. The polarizer 5 is configured to provide a polarization direction for the light. The polarizer 5 surrounds or partially surrounds the at least one LED filament 1 so that the light emitted from the LED filament lamp 7, or a portion of the light, can be polarized or unpolarized.

Description

[Technical Field]

[0001] The present invention relates to an LED filament lamp for emitting polarized light. [Background technology]

[0002] US 2015 / 101246 A1 discloses a lighting device for plant cultivation that includes a unit configured to convert light within any wavelength range of 300 nm to 600 nm (e.g., wavelengths between 452 nm and 474 nm) into light within a wavelength range having a predominantly right-handed circularly polarized component. The lighting device enables the emission of light that can provide specific effects in plant cultivation. Thus, the lighting device is essentially an LED lamp that supplies polarized light.

[0003] A trend in lighting is the use of LED filament lamps. LED filament lamps can be used for retrofit purposes, such as LED lamps designed to resemble traditional incandescent light bulbs with a visible filament for aesthetic and light distribution purposes, with the high efficiency of light-emitting diodes. Decorative light bulbs, in particular, are difficult to imitate when using LEDs; for example, spiral filament bulbs often lack authenticity. When LED filament lamps are compared to the well-known traditional Edison lamp, users often dislike the light emitted from LED filament lamps. Summary of the Invention [Problem to be solved by the invention]

[0004] The object of the present invention is to solve this problem by improving the performance and / or appearance of light emitting diode (LED) filament lamps. [Means for solving the problem]

[0005] According to a first aspect of the invention, this and other objects are provided by an LED filament lamp for providing polarized LED filament lamp light, comprising: - an LED filament having a plurality of LEDs arranged on a filament carrier, the LED filament being configured to emit LED filament light, the LED filament being configured to be arranged in the LED filament lamp; a light exit window; This is achieved by providing an LED filament lamp having a polarizer that completely or partially surrounds the LED filament and is configured to polarize at least a portion of the LED filament light to make it polarized LED filament light, such that at least a portion of the polarized LED filament light is emitted through the light exit window as the polarized LED filament lamp light.

[0006] An LED filament lamp, also referred to as an LED filament bulb, is an LED lamp designed to resemble a conventional incandescent light bulb with a visible filament for aesthetic and light distribution purposes. The LED filament lamp has high efficiency when using LED or any solid-state lighting technology. Because the LED filament lamp can have an envelope shape and base similar to those of a conventional incandescent light bulb, the LED filament lamp can easily replace a conventional incandescent light bulb. Furthermore, the LED filament lamp can operate at several different supply voltages that can be predetermined to suit the application. The LED filament lamp can provide a light distribution angle similar to that of a conventional incandescent light bulb.

[0007] The LED filament includes a plurality of LEDs disposed on a filament support. The LED filament may be elongated and have a longitudinal axis. The filament support is configured to carry a plurality of LEDs. The LEDs may be connected to the filament support in a direction along the filament support. The filament support may be a plate having a first side and a second side. The LEDs may be disposed on the first side of the filament support plate or on both sides of the plate. The LEDs may be electrically connected to a power source via the filament support.

[0008] The LEDs may be electrically connected to a power source via electrical connections along the support. The elongated filament support may have the LEDs electrically connected in series and / or parallel connected strings of LEDs, such that the LEDs appear similar to the filaments of an incandescent light bulb, for example.

[0009] A polarizer having a polarization direction is disposed in a position where the polarizer surrounds or partially surrounds the filament support and the LEDs so that light emitted from the LED filament is at least partially polarized. The polarizer may surround at least 60% of the LED filament. Preferably, at least 70% of the polarizer may surround the LED filament. More preferably, at least 80% of the polarizer may surround the LED filament. Most preferably, at least 90% of the polarizer may surround the LED filament. In another example, the LED filament may be completely surrounded by the polarizer.

[0010] The term "polarized LED filament lamp light" is intended to mean that the light exiting the light exit window is polarized or substantially polarized light. Substantially polarized light means that in an operational mode, at least 90% of the light exiting the light exit window is polarized light. The light exiting the light exit window may preferably be at least 95% polarized light. More preferably, at least 98% of the light exiting the light exit window is polarized light. Most preferably, at least 99% of the light exiting the light exit window is polarized light, such as, for example, 100% of the light exiting the light exit window is polarized light.

[0011] The polarizer can be positioned relative to the LED filament such that the polarizer passes light of a particular polarization, or a portion of light of a particular polarization, from the LED while blocking other polarizations of light emitted from the LED.

[0012] The polarized light may have a first polarization direction relative to the longitudinal direction of the LED filament lamp. Alternatively, the polarized light may have a second polarization direction relative to the longitudinal direction of the LED filament lamp, the second polarization direction being different from the first polarization direction.

[0013] A first polarizer providing the first polarization direction and a second polarizer providing the second polarization direction may be disposed relative to the LED filament. The first polarization direction may be different from the second polarization direction. In another embodiment, the first polarization direction may be substantially equal to the second polarization direction. In this manner, a larger portion of the first LED filament is covered with one or more polarizers. The filament support may be rigid, for example, made of glass, metal, quartz, or sapphire. Alternatively, the filament support may be substantially flexible so that the filament can be bent. The filament support may be light-transmitting, which provides translucent reflection through the support, which may provide a decorative effect when the LED filament is emitting light.

[0014] In an embodiment of the invention, the LED filament has an elongated encapsulant covering or encapsulating the plurality of LEDs, the encapsulant including a luminescent material configured to at least partially convert LED light emitted by the plurality of LEDs into converted light.

[0015] The LED filament may be a filament support having an encapsulant. The LED filament includes an elongated encapsulant covering or encapsulating the LEDs. The encapsulant may include a luminescent material configured to at least partially convert LED light emitted by the LEDs into converted light.

[0016] In an embodiment of the invention, the polarizer is a reflective polarizer.

[0017] The reflective polarizer may be disposed as a tubular cover surrounding or partially surrounding the filament support with the encapsulant. The filament support may be an elongated filament support with an elongated encapsulant. The reflective polarizer may be, for example, glued to the encapsulant. The reflective polarizer may be a circular or polygonal polarizer that transmits light of a desired polarization and reflects the remaining light in another direction.

[0018] In an embodiment of the invention, the polarizer is a flexible reflective polarizer.

[0019] The polarizer may be formed as a fairly tight tube around the filament support with the elongated encapsulant. The polarizer may be a flexible reflective polarizer. Depending on the orientation of the flexible reflective polarizer, the light reflection can be arranged differently to change the intensity or contrast of the light emitted from the LED filament lamp.

[0020] The flexible polarizer may be attached to the encapsulant. The flexible polarizer may be a flexible reflective polarizer. The flexible reflective polarizer may be, for example, glued to the encapsulant. In another example, the polarizer may be, for example, a film wrapped around the elongated encapsulant. At least one polarizer may be disposed in a spiral arrangement with respect to the elongated filament support including the elongated encapsulant. The polarizer may be disposed in a spiral arrangement so that a portion of the light emitted from the LED filament lamp is polarized.

[0021] In a further embodiment of the invention, a quarter wave plate is disposed relative to the polarizer.

[0022] A quarter-wave plate may be positioned relative to the polarizer, or the quarter-wave plate may be positioned along the polarizer. Alternatively, the quarter-wave plate may be positioned around the polarizer to generate circularly polarized light. As an alternative to a quarter-wave plate, a quarter-wave foil may be used. This provides a decorative effect when the LED filament is emitting light, for example, when using a reflective polarizer. The cholesteric effect may also be used, for example, when using liquid crystals.

[0023] In yet another embodiment of the present invention, the LED filament is a linear LED filament, and the polarizer is disposed in a curved position at least partially around the linear LED filament.

[0024] The LED filament may be a linear LED filament having a longitudinal direction. A polarizer may be disposed at least partially around the linear LED filament in a curved position. The long, straight LED filament may include a linear, elongated filament support. The filament support may include a support plate. The linear, elongated support plate may include a plurality of LEDs mounted in a long row on a first side of the elongated support plate. In another example, the plurality of LEDs may be mounted in a long row on both or all sides of the elongated support plate, emitting light substantially around the periphery of the elongated support plate.

[0025] The elongated filament support may be shaped as a curved filament support, or the filament support may have a curved portion. The curved LED filament may be shaped, for example, as a spirally curved LED filament arranged in a spiral configuration relative to the longitudinal axis of the LED filament lamp. The curved filament support may be used to enhance decorative effects in LED lamps or LED filament lamps.

[0026] In yet another embodiment of the invention, the LED filament has a spiral or helix shape and the polarizer is disposed in a spiral or helix position relative to the LED filament, or the polarizer is disposed in a curved position at least partially around the LED filament.

[0027] The curved, elongated LED filament may be shaped, for example, as a spirally curved LED filament arranged in a spiral configuration relative to the longitudinal axis of the LED filament lamp. The curved LED filament arranged within the LED filament may provide a predetermined visual lighting effect during use. The curved LED filament may include a flexible polarizer or a flexible reflective polarizer. The flexible polarizer or the flexible reflective polarizer may be flexible only in a first direction and thus spirally arranged around the spirally curved LED filament. In another example, the polarizer may be arranged at the center of the spirally curved LED filament such that the spirally curved LED filament is spirally arranged around the polarizer. The LED filament lamp may include at least one curved or partially curved LED filament.

[0028] In a further embodiment of the present invention, the LED filament lamp has a base cap for electrically and mechanically connecting the LED filament lamp to a socket of a lighting fixture, the LED filament lamp having an envelope enclosing a volume, and the LED filament and the polarizer are disposed within the volume.

[0029] The LED filament has at least one electrical connection, which can be electrically connected to a power source. The LED filament may also have a mechanical connection so that the LED filament can be attached to a lighting fixture or to a base cap for a lighting fixture socket. The control device may include an LED driver. The electrical connection may be connected to an LED driver and / or a control device. The control device may control the LED driver driving the LEDs included in the LED filament. The control device is in electrical communication with the elongated LED filaments, and the control device is configured to vary the luminous flux emitted from the LED filaments. The control device may control the luminous flux from at least one LED filament. By individually controlling the luminous flux, reflection of the LED filament light on the cover surface of the LED filament lamp can be reduced to improve the visibility of the LED filament or enhanced to create a flame-like appearance, depending on the intended application of the LED filament lamp.

[0030] The LED driver and / or control device may be disposed within a base housing that may be completely or partially disposed within the base cap. The base cap may be compatible with the socket. The socket may provide power to the LED filament in the LED filament lamp.

[0031] The LED filament lamp has an envelope surrounding a volume, and the LED filament and / or the polarizer are disposed within the volume. The envelope may have one or more light exit windows.

[0032] The polarizer may be fixed in a predetermined position within the envelope. The LED filament lamp has the envelope, and the LED filament is disposed within the volume. The LED filament lamp may have a polarizer disposed within the volume, and the polarizer may be attached to the inner surface of the envelope. The polarizer may be attached to the inner surface of the light exit window included in the envelope. The polarizer may, for example, be easily glued or otherwise fixed to the inner surface of the envelope.

[0033] In yet another embodiment of the present invention, the polarizer has a cylinder-like shape.

[0034] The envelope of the LED filament lamp may have a tubular shape. The polarizer may have a cylindrical shape so that the polarizer fits easily into the tubular envelope. A portion of the envelope may be a tubular or semi-tubular light exit window. The polarizer may be attached to the inner surface of the envelope. The polarizer may be attached to the inner surface of the envelope, which may be the light exit window. Tubular light sources are commonly used in street lighting, floodlighting, warehouses, and other commercial applications where high light output and efficiency are essential. The LED filament may be disposed at a predetermined position within the envelope. The tubular envelope may provide a predetermined visual lighting effect when in use. The LED filament lamp may provide light emitted in at least one direction perpendicular to the longitudinal direction of the tubular envelope. The polarized LED filament light is emitted through the light exit window as the polarized LED filament lamp light.

[0035] The LED filament lamp can be used for lighting and / or decorative effects. The LED filament lamp can be disposed in a socket within a lighting fixture. In another example, the LED filament lamp can be disposed in a socket such that the LED filament lamp becomes a lighting fixture. The LED filament lamp includes an enclosed volume having an envelope. The LED filament lamp has at least one LED filament, at least one of the at least one LED filament being an elongated LED filament. The LED filament lamp can be a retrofit LED filament lamp. The LED filament lamp can have a base cap for a retrofit socket or a standardized socket.

[0036] The LED filament lamp may have an elongated envelope that provides the LED filament lamp with a longitudinal axis. The LED filament may be disposed at a predetermined position within the enclosed volume. The LED filament may be configured to emit polarized light having a polarization direction.

[0037] In an embodiment of the present invention, the longitudinal axis of the LED filament is disposed at an angle to the longitudinal axis of the LED filament lamp, and the polarization direction of the polarized LED filament light is non-parallel and non-perpendicular to the longitudinal axis of the LED filament.

[0038] The LED filament may be an elongated LED filament having a longitudinal axis. The elongated LED filament may be disposed at a predetermined position within the enclosed volume of the LED filament lamp. The elongated LED filament may be configured to emit polarized light. The elongated LED filament emits light polarized relative to the longitudinal axis of the elongated LED filament. The longitudinal axis of the elongated LED filament may be disposed at a position non-parallel or non-perpendicular to the longitudinal axis of the LED filament lamp. In another example, the polarization direction of the polarized LED filament light may be parallel or perpendicular to the longitudinal axis of the LED filament.

[0039] The LED filament is disposed at an angle relative to the longitudinal axis of the LED filament lamp. The angled position may be 20 to 70 degrees relative to the longitudinal axis of the LED filament lamp. The angled position may be 25 to 60 degrees relative to the longitudinal axis of the LED filament lamp. The angled position may be 30 to 60 degrees relative to the longitudinal axis of the LED filament lamp.

[0040] The longitudinal axis of the elongated LED filament may be disposed parallel to the longitudinal axis of the LED filament lamp so that the LED filament emits light polarized in a first polarization direction. The elongated LED filament may be disposed at an angle to the longitudinal axis of the LED filament lamp so that the LED filament emits light polarized in a second polarization direction. The second polarization direction is different from the first polarization direction. At least 80% of the LED filament lamp light may be linearly polarized or circularly polarized. Preferably, at least 85% of the LED filament lamp light may be linearly polarized or circularly polarized. More preferably, at least 90% of the LED filament lamp light may be linearly polarized or circularly polarized. Most preferably, at least 95% of the LED filament lamp light may be linearly polarized or circularly polarized.

[0041] The LED filament lamp may have at least one elongated LED filament disposed at an angle relative to the longitudinal axis of the LED filament lamp. The LED filament lamp may include displacing the elongated LED filament relative to the longitudinal axis of the LED filament lamp. When displaced, the LED filament may have a longitudinal axis disposed at an angle relative to the longitudinal axis of the LED filament lamp. The polarization direction of the polarizer disposed relative to the LED filament may also be disposed such that the angle of the polarization direction is ±90°. In this manner, the polarization direction may be parallel or perpendicular to the longitudinal axis of the LED filament lamp.

[0042] In a further embodiment of the present invention, the LED filament lamp comprises an encapsulant, the encapsulant being disposed relative to the LED filament, and the polarizer being in optical contact with the encapsulant.

[0043] The LED filament may be surrounded or partially surrounded by an encapsulant. The polarizer may be disposed at a predetermined position relative to the LED filament and / or the encapsulant such that the polarizer is in optical communication with the encapsulant. The predetermined position of the polarizer relative to the encapsulant may be provided to optimize the optical performance of the LED filament lamp.

[0044] The encapsulant may be luminescent. The encapsulant may contain more or less luminescent material. The encapsulant is configured to fully or partially surround the LEDs or a portion of the LEDs. The luminescent encapsulant is configured to convert the LED filament light into converted light. The encapsulant may be an elongated encapsulant. All or a portion of the encapsulant may contain luminescent material so that light from the LEDs is fully or partially converted. One or more polarizers may fully or partially surround the elongated encapsulant so that light emitted from the LED filament or a portion of the light is polarized. The converted light is transmitted through the polarizer to become converted polarized light, which is then emitted from the LED filament lamp.

[0045] In yet another embodiment of the present invention, the polarizer is disposed at a predetermined distance from the LED filament.

[0046] The polarizer may be disposed at a predetermined distance from the LED filament that is different from zero. The distance between the polarizer and the LED filament may be at least 3 mm. The distance between the polarizer and the LED filament may be greater, preferably at least 6 mm. More preferably, the distance between the polarizer and the LED filament may be at least 10 mm. Most preferably, the distance between the polarizer and the LED filament may be at least 15 mm, for example, 20 mm. For example, the LED filament is located in the center of the LED filament lamp, and the polarizer is attached to the inner surface of the envelope. This results in a distance between the polarizer and the LED filament.

[0047] In yet another embodiment of the present invention, the LED filament lamp has at least one of the LED filaments configured to emit light having a first polarization direction parallel to the longitudinal axis of the first LED filament lamp and at least one further LED filament configured to emit light having a second polarization direction perpendicular to the longitudinal axis of the LED filament lamp, and the LED filament lamp has a controller for individually controlling the LED filament and the further LED filament.

[0048] The controller is capable of individually controlling the LED filaments during use. The predetermined distance of the polarizer relative to the LED filaments can be established to optimize the optical performance of the LED filament lamp. By individually controlling the LED filaments, the optical performance of the LED filament lamp can be changed during use.

[0049] The LED filament lamp may have at least two elongated LED filaments. The first and second elongated LED filaments may be arranged parallel to each other or at an angle to each other. The first and second elongated LED filaments are also arranged relative to the longitudinal axis of the LED filament lamp. The first elongated LED filament may have a first polarizer providing a first polarization direction. The second elongated LED filament may have a second polarizer providing a second polarization direction. The second polarization direction may be similar to the first polarization direction. In another example, the second polarization direction may be different from the first polarization direction. The LED filament has an electrical connection connected to a control device disposed within the base housing. The base housing may be attached to the base cap for a socket.

[0050] By independently controlling both the reflection of the first LED filament and the reflection of the second LED filament, the reflection of the LED filament light on the cover surface of the LED filament lamp can be reduced for improved visibility of the LED filament and / or enhanced for a flame-like appearance, depending on the given application in which the LED filament lamp is used.

[0051] The LED filament lamp can be controlled such that in a first operating mode, only one or more first LED filaments that supply p-polarized light are electrically activated, and in a second operating mode, only one or more second LED filaments that supply s-polarized light are electrically activated. The LED filament lamp can switch between p-polarized light and s-polarized light when electrically controlling the LED filaments.

[0052] In another example, the LED filament lamp can be controlled so that in a first operating mode, only one or more first LED filaments that provide p-polarized light are electrically activated, or in a second operating mode, only one or more second LED filaments that provide s-polarized light are electrically activated. In the second operating mode, the LED filament lamp can be controlled so that both the first LED filament and the second LED filament can be electrically activated simultaneously. In this manner, the LED filament lamp can switch between polarizations, i.e., p-polarized and s-polarized light, and unpolarized light.

[0053] In yet another embodiment, the LED filament lamp has a first LED filament having a first longitudinal direction and a second LED filament having a second longitudinal direction, the first LED filament and the second LED filament having similar polarizers so that light emitted from each of the LED filaments has the same polarization direction, the first LED filament and the second LED filament are arranged at an angle β relative to the first longitudinal direction and the second longitudinal direction of each LED filament, the angle β being in the range of 15 degrees to 80 degrees, and the light emitted from each of the LED filaments having the same polarization direction.

[0054] The LED filament lamp has at least two elongated LED filaments. An angle β defines the angle between the first and second longitudinal axes of each LED filament. Each of the LED filaments may be provided with a respective polarizer. The first and second LED filaments have similar polarizers so that light emitted from each of the LED filaments has the same polarization direction. Each of the LED filaments may be disposed at an angle β that may be different from 0° relative to the longitudinal axis of each of the LED filaments. In another example, each of the LED filaments, or one of the longitudinal axes of the LED filaments, may be disposed at an angle β that may be different from 0° relative to the respective longitudinal axes of the other LED filaments. The first and second LED filaments are disposed at an angle β based on the first and second longitudinal axes of each LED filament, and the angle β may be in the range of 15 to 80 degrees. Light emitted from each of the LED filaments has the same polarization direction.

[0055] In another example, the longitudinal axis of a first LED filament may be disposed parallel to the longitudinal axis of the LED filament lamp, and the LED filament emits light polarized in a first polarization direction. The longitudinal axis of a second LED filament may be disposed at an angle to the longitudinal axis of the LED filament lamp, and the second LED filament emits light polarized in a second polarization direction, which is different from the first polarization direction.

[0056] LED lamps with such LED filaments offer enhanced designs that resemble traditional incandescent bulbs for aesthetic and light distribution purposes, along with the high efficiency of LEDs, particularly decorative bulbs that resemble traditional spiral bulbs without losing their authenticity.

[0057] The invention further relates to a lighting fixture comprising at least one LED filament lamp according to the invention.

[0058] The LED filament lamp may be disposed within the lighting fixture, and the LED filament lamp may be used for lighting and / or decorative effects. The LED filament lamp may provide a direct lighting effect or an indirect lighting effect. The lighting fixture may have a socket, and the socket is configured to receive the base cap of the LED filament lamp.

[0059] It is to be noted that the invention relates to all possible combinations of the features recited in the claims. [Brief explanation of the drawings]

[0060] This and other aspects of the invention will now be described in more detail with reference to the accompanying drawings, in which embodiments of the invention are shown. [Figure 1a] 1A-1C illustrate vertical cross-sectional views of various embodiments of elongated LED filaments of an LED lamp according to the present invention. [Figure 1b]1A-1C illustrate vertical cross-sectional views of various embodiments of elongated LED filaments of an LED lamp according to the present invention. [Figure 2] 1 illustrates a cross-sectional view of an embodiment of an LED filament lamp according to the present invention having an elongated LED filament. [Figure 3] 1 illustrates a cross-sectional view of an embodiment of an LED filament lamp according to the present invention having two elongated LED filaments. [Figure 4] 1 illustrates a cross-sectional view of an embodiment of an LED filament lamp according to the present invention having a displaced elongated LED filament. [Figure 5] 1 illustrates a cross-sectional view of an embodiment of an LED filament lamp according to the present invention having an elongated, spirally curved LED filament.

[0061] The sizes of layers and regions as shown in the figures have been exaggerated for illustrative purposes and are therefore shown to illustrate the general structure of embodiments of the present invention. Like reference numerals refer to like elements throughout. DETAILED DESCRIPTION OF THE INVENTION

[0062] The present invention will now be described more fully hereinafter with reference to the accompanying drawings, in which presently preferred embodiments of the invention are shown. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are presented for thoroughness and completeness, and will fully convey the scope of the invention to those skilled in the art.

[0063] 1a and 1b illustrate an embodiment of an elongated LED filament 1 for an LED lamp 7 according to the present invention. The elongated LED filament 1 includes a plurality of LEDs 3 arranged on an elongated filament support 2. The elongated filament support 2 is formed as a linear elongated filament support 2. An elongated encapsulant 4 is configured to cover or partially cover the plurality of LEDs 3 or some of the LEDs 3. The elongated encapsulant 4 may include a luminescent material such that light from the LEDs 3 is converted or partially converted into converted light. For example, the LEDs 3 may emit light in the blue wavelength range, and the luminescent material may include a phosphor material such that the converted light is white light. The converted light passes through a polarizer 5 to become converted polarized light, which is then emitted from the elongated LED filament 1.

[0064] At least one polarizer 5 having a polarization direction surrounds or partially surrounds the elongated encapsulant 4 so that the light emitted from the elongated LED filament 1 or part of said light is polarized.

[0065] The elongated LED filament is connected to a first electrical connection 6 1 to the second electrical connection portion 6 2 The LED 3 has a longitudinal axis X extending to the electrical connection 6 1 , 6 2 The power supply may be electrically connected to the power source via

[0066] The elongated filament support 2 is configured to carry an LED 3. The LED 3 is attached to the filament in a direction along the filament support 1. The LED 3 is disposed on a first surface of the elongated filament support 2. The LED 3 provides a substantially semi-cylindrical illumination with polarized light.

[0067] Figure 1a illustrates first and second embodiments of an elongated LED filament 1. The first embodiment of the elongated LED filament 1 (left side of Figure 1a) has a first polarization direction P, illustrated by an arrow parallel to the longitudinal axis X of the elongated LED filament 1. 1A second embodiment of a second elongated LED filament 1 (right side of FIG. 1a) has a polarizer 5 that provides a polarized light having a second polarization direction P, which is illustrated by an arrow having an angle different from zero with respect to the longitudinal axis X of the elongated LED filament 1. 2 a polarizer 5 for providing polarized light having a second polarization direction P 2 is the first polarization direction P 1 The elongated LED filament 1 can be incorporated into an LED filament lamp or the like. 2 The first polarization direction P 1 Depending on the orientation, the reflection of the LED filament light on the cover surface of the LED filament lamp can be reduced for improved visibility of the LED filament 1 or can be enhanced for a flame-like appearance, depending on the given application in which the LED filament lamp is being used.

[0068] FIG. 1b illustrates three different cross-sectional shapes of the elongated LED filament 1. The elongated filament support 2 may be an elongated support plate sealed with an encapsulant. The polarizer 5 is configured as a tubular cover that surrounds or partially surrounds the elongated filament support 2 with the encapsulant (see the top of FIG. 1b). In another example, the polarizer may have a cross-sectional shape that is a circular or polygonal cover (see the center of FIG. 1b). Furthermore, the polarizer may have a cross-sectional shape provided by first and second flat elongated polarizers 5 disposed on either side of the elongated filament support 2 (see the bottom of FIG. 1b). The first and second polarizers 5 may have different polarization directions.

[0069] FIG. 2 illustrates an embodiment of an LED filament lamp 7 having an elongated LED filament 1. The LED filament lamp 7 is a retrofit lamp for lighting. The LED filament lamp 1 includes an enclosed volume V having a cover surface 10. The LED filament lamp 7 has a longitudinal axis LA. The elongated LED filament 1 is disposed within the enclosed volume V, and the elongated LED filament 1 extends parallel to the longitudinal axis LA of the LED filament lamp 7. The elongated LED filament 1 is configured to emit light having a polarization direction P, as shown by the arrow.

[0070] The LED filament 1 has an electrical connection 6 that can be electrically connected to an LED driver 8, which is electrically connected to a base 9 for a socket. The LED filament 1 may also have a mechanical connection so that the LED filament can be attached to the housing of the LED driver 8.

[0071] Figure 3 shows two elongated LED filaments 1 1 , 1 2 1 illustrates an embodiment of an LED filament lamp 7 having a first elongated LED filament 1 1 and a second elongated LED filament 1 2 are arranged parallel to each other. 1 and a second elongated LED filament 1 2 The first elongated LED filament 1 is also disposed parallel to the longitudinal axis LA of the LED filament lamp 7. 1 is the first polarization direction P 1 a first polarizer for providing light having a second elongated LED filament; 2 is the second polarization direction P 2 a second polarizer that provides light having a second polarization direction P 2 is the first polarization direction P 1 LED filament 1 1 , 1 2each have an electrical connection connected to a control device 11 located in a housing attached to a base 9 for the socket.

[0072] 1st LED filament 1 1 Reflector and second LED filament 1 2 By separately controlling both the reflection of the LED filament light at the cover surface 10 of the LED filament lamp 7, the reflection of the LED filament light at the cover surface 10 of the LED filament lamp 7 can be reduced for improved visibility of the LED filament 1, or enhanced for a flame-like appearance, depending on the given application in which the LED filament lamp is used.

[0073] 4 illustrates an embodiment of an LED filament lamp 7 having a displaced elongated LED filament 1. The longitudinal axis X of the LED filament is disposed at an angle φ' with respect to the longitudinal axis LA of the LED filament lamp 7. The polarization direction P of the light provided by the polarizer disposed on the LED filament 1 is disposed so that the angle is φ' or φ' + 90°. In this manner, the polarization direction P is parallel or perpendicular to the longitudinal axis LA of the LED filament lamp 7.

[0074] FIG. 5 illustrates an embodiment of an LED filament lamp 7 having a spirally curved LED filament 1. The spirally curved LED filament 1 is disposed in a spiral configuration relative to the longitudinal axis LA of the LED filament lamp 7. The spirally curved LED filament 1 may include a flexible polarizer or a flexible reflective polarizer 5. Because the LED filament 1 is flexible only in a first direction, the polarizer 5 may be spirally disposed around the spirally curved LED filament. In another example, the polarizer 5 may be disposed in the center of the spirally curved LED filament along the longitudinal axis LA of the LED filament lamp 7 such that the spirally curved LED filament is spirally disposed around the polarizer 5. In another example, the first polarizer may be spirally arranged around the spirally curved LED filament, and the second polarizer may be arranged in the center of the spirally curved LED filament along the longitudinal axis LA of the LED filament lamp 7, with the spirally curved LED filament being spirally arranged around the polarizer.

[0075] Those skilled in the art will appreciate that the present invention is by no means limited to the preferred embodiments described above, but on the contrary, many modifications and variations are possible within the scope of the appended claims.

[0076] Furthermore, those skilled in the art will understand and achieve modifications to the disclosed embodiments in practicing the claimed invention, from a study of the drawings, the specification and the appended claims. In the claims, the word "comprises" does not exclude other elements or steps, and the singular does not exclude a plurality. The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measures cannot be used to advantage.

Claims

1. Polarized LED filament lamp: An LED filament lamp for providing light, an LED filament having a plurality of LEDs disposed on a filament support, the LED filament configured to emit LED filament light, the LED filament configured to be disposed within the LED filament lamp; an envelope having a light exit window; an LED filament lamp having a polarizer that completely or partially surrounds the LED filament and is configured to polarize at least a portion of the LED filament light to make it polarized LED filament light, wherein at least a portion of the polarized LED filament light is emitted through the light exit window as the polarized LED filament lamp light; An LED filament lamp wherein the polarizer is a reflective polarizer.

2. 2. The LED filament lamp of claim 1, wherein the LED filament has an elongated encapsulant that covers or encapsulates the plurality of LEDs, the encapsulant including a luminescent material configured to at least partially convert LED light emitted by the plurality of LEDs into converted light.

3. 3. An LED filament lamp according to claim 1, wherein the polarizer is a flexible reflective polarizer.

4. 4. An LED filament lamp according to claim 1, wherein a quarter-wave plate is disposed downstream of the polarizer.

5. 5. An LED filament lamp according to claim 1, wherein the LED filament is a linear LED filament, and the polarizer is disposed at least partially around the LED filament in a curved position.

6. The LED filament has a spiral or helix shape, and the polarizer is (i) disposed in a spiral or helical position relative to the LED filament; or 5. An LED filament lamp as claimed in any one of claims 1 to 4, wherein (ii) the LED filament is disposed in a curved position at least partially around the LED filament.

7. 7. An LED filament lamp according to any one of claims 1 to 6, wherein the LED filament lamp has a base cap for electrically and mechanically connecting the LED filament lamp to a socket of a lighting fixture, the LED filament lamp has the envelope surrounding a volume, and the LED filament and the polarizer are disposed within the volume.

8. 8. An LED filament lamp as claimed in any one of claims 1 to 7, wherein the polarizer is attached to the inner surface of the envelope.

9. 9. An LED filament lamp according to claim 1, wherein the longitudinal axis of the LED filament is disposed at an angle with respect to the longitudinal axis of the LED filament lamp, and the polarization direction of the polarized LED filament light is non-parallel and non-perpendicular to the longitudinal axis of the LED filament.

10. 10. An LED filament lamp as described in any one of claims 1 to 9, wherein the LED filament has an elongated encapsulant covering or encapsulating the plurality of LEDs, and the polarizer is in optical contact with the encapsulant.

11. 10. An LED filament lamp according to claim 1, wherein the polarizer is disposed at a predetermined distance from the LED filament.

12. 12. An LED filament lamp according to any one of claims 1 to 11, wherein the LED filament lamp has at least one of the LED filaments configured to emit light having a first polarization direction parallel to the longitudinal axis of the LED filament lamp, and at least one further LED filament configured to emit light having a second polarization direction perpendicular to the longitudinal axis of the LED filament lamp, and the LED filament lamp has a controller for individually controlling the LED filament and the further LED filament.

13. The LED filament lamp has a first LED filament having a first longitudinal axis and a second LED filament having a second longitudinal axis, the first LED filament and the second LED filament have similar polarizers so that light emitted from each of the LED filaments has the same polarization direction, and the first LED filament and the second LED filament are arranged at an angle β with respect to the first longitudinal axis and the second longitudinal axis of each LED filament, the angle β being within the range of 15 degrees to 80 degrees. An LED filament lamp according to any one of claims 1 to 11.

14. 14. An LED filament lamp as claimed in any one of claims 1 to 13, wherein the polarizer has a cylindrical shape.

15. A luminaire for illumination, comprising at least one LED filament lamp according to any one of claims 1 to 14.

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