Light emitting device

Abstract

An LED filament lamp emits a lamp light having a third correlated color temperature CCT3. The LED filament light source emits LED filament light having a first correlated color temperature CCT1, a first luminous intensity I1 and a first luminous flux LF1. A transparent envelope at least partially surrounds the LED filament light source. A further LED light source provides further LED light having a second correlated color temperature CCT2, a second luminous intensity I2 and a second luminous flux LF2. The further LED light source provides the further LED light to the envelope. The envelope is a light emitting structure configured to emit the further LED light and to transmit the LED filament light. Thus, the lamp light comprises one or more of the LED filament light and the further LED light, and CCT1 < 2500 K, 8000 K > CCT2 > 3500 K and 2 > LF1 / LF2 > 0.5, wherein CCT1, CCT2 and LF1 / LF2 are chosen such that 3400 K > CCT3 > 2600 K.

Description

Technical Field

[0001] This invention generally relates to light-emitting devices. More specifically, this invention relates to a light-emitting diode (LED) filament lamp, which includes an LED filament light source and a transparent housing. Background Technology

[0002] The original electrically powered light bulbs were of the type that enclosed a metal wire filament within a glass bulb that was more or less evacuated. For over a century, this type of bulb was the ubiquitous light source of choice until the introduction of LEDs. LED-based light sources have now replaced light bulbs as the primary light source in homes and many other places. Initially, primarily due to the inherent structural characteristics of LEDs, early LED light sources (i.e., LED lamps) differed in appearance from early light bulbs and were considered aesthetically inferior to earlier types of bulbs in many cases. Therefore, for aesthetic reasons, when it was discovered that it was technically feasible to manufacture light sources using LED filaments, the expectation for light sources with the appearance of filament lamps in the shape of traditional light bulbs returned.

[0003] However, this type of light source using LED filaments still has various problems. For example, there is still a need to improve the performance and / or appearance of light sources using LED filaments.

[0004] WO 2023 / 213608 provides a lighting device comprising: a light-emitting element and a translucent housing surrounding the light-emitting element and having a surface area at least three times larger than the light-emitting area of ​​the light-emitting element, wherein the housing is coated with a phosphor layer having a thickness of 0.05-1.0 mm and the phosphor layer is configured to block less than 30% of visible light emitted by the light-emitting element.

[0005] US 11519563 provides a light-emitting device including a transparent light-emitting window and an LED filament adapted to emit a first light output through the transparent light-emitting window in one or more light-emitting directions. The light-emitting device includes a light guide. The light guide includes coupling features configured to receive light emitted by a light source and couple the light emitted by the light source into the light guide. The light source includes or is composed of at least one of the LED filament or separate light sources included in the light-emitting device. Summary of the Invention

[0006] It is of interest to provide an LED filament lamp that can overcome the shortcomings of existing technology devices.

[0007] This and other objectives are achieved in the first aspect by providing an LED filament lamp having the features of the appended independent claims. Preferred embodiments are defined in the appended dependent claims.

[0008] Therefore, according to the present invention, an LED filament lamp is provided, which is configured to emit light having a third correlated color temperature (CCT3) during operation. The LED filament lamp includes an LED filament light source configured to emit LED filament light having a first correlated color temperature (CCT1), a first luminous intensity (I1), and a first luminous flux (LF1) during operation. A transparent housing at least partially surrounds the LED filament light source.

[0009] The additional LED light source is configured to provide additional LED light with a second correlated color temperature CCT2, a second luminous intensity I2, and a second luminous flux LF2.

[0010] The transparent housing is light-scattering and has a reflectivity of less than 20%. Preferably, the reflectivity is at least 7%. The inventors have found that with such reflectivity, the visibility of the LED filament is high, while providing sufficient additional LED light in a uniform manner (e.g., from the light guide).

[0011] The additional LED light source is configured to provide additional LED light to the housing. The housing is a light-emitting structure configured to emit the additional LED light and transmit LED filament light during operation. Therefore, the light includes one or more of LED filament light and additional LED light, and CCT1 ≤ 2500K (preferably CCT1 ≥ 1600K), 8000K ≥ CCT2 ≥ 3500K, and 2 ≥ LF1 / LF2 ≥ 0.5, wherein CCT1, CCT2, and LF1 / LF2 are selected such that 3400K ≥ CCT3 ≥ 2600K.

[0012] This CCT difference, combined with the LF ratio between the filament and the housing, makes the LED filament clearly visible through the slightly diffused luminescent housing. In other words, the effect of this configuration is to provide uniform functional light in the far field, namely white light with a CCT3 in the range of 2600-3400K, located at or near the blackbody locus (BBL) in the International Commission on Illumination (CIE) 1931 color space, while the LED filament is clearly visible through the slightly diffused luminescent housing.

[0013] In various embodiments, the LED filament light, additional LED light, and the light source can be white light. This type of light is preferred for general lighting.

[0014] In various embodiments, 2300K ≥ CCT1 ≥ 1700K, 5000K ≥ CCT2 ≥ 3500K, and / or 3300K ≥ CCT3 ≥ 2700K. These CCTs are preferred for general lighting.

[0015] In various embodiments, the additional LED light may have a second color point, and the LED filament light may have a first color point that is closer to the blackbody locus (BBL) in the International Commission on Illumination (CIE) 1931 color space than the second color point. For example, the second color point may be at least 10 standard deviations (SDCM) above the BBL.

[0016] The housing may include a light guide comprising a light output device and a light input surface. At least a portion of the additional LED light can then be coupled into the light guide via the light input surface, guided through the light guide by total internal reflection, and subsequently coupled out of the light guide via the light output device (e.g., a light reflection point or pattern). In other embodiments, an additional LED light source is configured to illuminate an inner surface of the housing. For example, the housing may include a light scattering layer, for instance, disposed on the main surface of the housing.

[0017] This light guide configuration of the housing improves the control of light emitted from additional LED light sources exiting the housing. The term "control" can refer to setting the desired light intensity and / or correlated color temperature. Furthermore, the inventors discovered that by using this configuration along with the conditions CCT1 ≤ 2500K, 8000K ≥ CCT2 ≥ 3500K, and 2 ≥ LF1 / LF2 ≥ 0.5, where CCT1, CCT2, and LF1 / LF2 are selected such that 3400K ≥ CCT3 ≥ 2600K, the visibility of the LED filament through the housing based on the light guide is further improved. This is because, when the lamp is lit under specified operating conditions, the area on the light guide not covered by the coupling device improves the visibility of the LED filament.

[0018] The first light intensity I1 can be correlated with the second light intensity I2, such that I1≥10 I2, preferably I1≥25 I2, more preferably I1≥50 I2, optimal value I1≥75 I2.

[0019] This relationship between I1 and I2 means that the visibility of the LED filament through the housing can be further improved, thereby improving the appearance of the LED filament lamp.

[0020] The first luminous flux LF1 can be correlated with the second luminous flux LF2, such that LF2 > LF1.

[0021] This relationship between LF1 and LF2 means that glare from the LED filament passing through the housing can be kept at an appropriate level, thereby improving the appearance of the LED filament lamp.

[0022] The LED filament lamp may also include a controller configured to control one or more of CCT1, CCT2, LF1, LF2, I1, and I2 (e.g., individually) by controlling the LED filament light source and the additional LED light source. In embodiments, the controller may control one or more of CCT1, CCT2, LF1, LF2, I1, and I2 based on inputs from a user interface, a clock module, and / or sensors.

[0023] The controller will be able to control the visibility and glare of LED filament light relative to other LED light, thereby improving the appearance of LED filament lamps.

[0024] For example, such a controller can make the first correlated color temperature CCT1 of the LED filament light source variable between a primary first correlated color temperature CCT1a and a secondary first correlated color temperature CCT1b that is different from the primary first correlated color temperature CCT1a, and make the third correlated color temperature CCT3 variable between a primary third correlated color temperature CCT3a and a secondary third correlated color temperature CCT3b that is different from the primary third correlated color temperature CCT3a.

[0025] This controller configuration allows for adjustment of the visibility of the LED filaments.

[0026] Furthermore, such a controller allows the second correlated color temperature (CCT2) of the additional LED light source to be variable between the primary second correlated color temperature (CCT2a) and the secondary second correlated color temperature (CCT2b) which is different from the primary second correlated color temperature (CCT2a), and the third correlated color temperature (CCT3) to be variable between the primary third correlated color temperature (CCT3a) and the secondary third correlated color temperature (CCT3b) which is different from the primary third correlated color temperature (CCT3a).

[0027] This controller configuration can also adjust the visibility of the LED filaments.

[0028] Such a controller allows the ratio LF1 / LF2 to be variable, making CCT3 variable, thereby adjusting the visibility of the LED filament. Alternatively, such a controller can also make both CCT1 and CCT2 variable simultaneously, while keeping CCT3 constant, i.e., within 300K, thus achieving a constant CCT3 but adjusting the visibility of the LED filament. In this context, "constant, i.e., within 300K" means that the maximum variation in CCT is 300K.

[0029] The LED filament light source may include an array of multiple LEDs arranged on a first main surface of an elongated carrier. The elongated package may at least partially cover the first main surface and at least partially surround the multiple LEDs. The additional LED light source may include red, green, and blue LEDs. For example, the red, green, and blue LEDs may be controlled by the controller to obtain additional white LED light.

[0030] In another aspect, a luminaire is provided that includes an LED filament lamp as described above, wherein the LED filament lamp includes a connector that is mechanically connected to and electrically connected to a socket of the luminaire.

[0031] Such lighting fixtures provide the effects and benefits outlined above. Attached Figure Description

[0032] These and other aspects of the invention will now be described in more detail with reference to the accompanying drawings, which illustrate embodiments of the invention, in which:

[0033] Figure 1a The illustration shows an LED filament lamp.

[0034] Figure 1b schematically illustrated Figure 1a Details of the LED filament lamp

[0035] Figure 2a The illustration schematically depicts an elongated carrier containing LEDs.

[0036] Figure 2b schematically illustrated Figure 2a The cross-sectional view of the carrier shown is along AA.

[0037] Figure 3 The diagram schematically illustrates the color points in the CIE 1931 color space.

[0038] Figures 4a-4c The diagram schematically illustrates the changes in CCT, and

[0039] Figure 5 The illustration shows a lighting fixture. Detailed Implementation

[0040] like Figure 1a and Figure 1bAs shown, one embodiment of an LED filament lamp 1 is configured to provide light 13 with a third correlated color temperature (CCT3) during operation, which includes an LED filament light source 100. The LED filament light source 100 is configured to emit LED filament light 11 with a first correlated color temperature (CCT1) having a first luminous intensity (I1) and a first luminous flux (LF1) during operation.

[0041] The transparent housing 101 at least partially surrounds the LED filament light source 100.

[0042] The additional LED light source 102 is configured to provide an additional LED light 12 having a second correlated color temperature (CCT2), a second luminous intensity (I2), and a second luminous flux (LF2).

[0043] The additional LED light source 102 is configured to provide additional LED light 12 to the housing 101, and the housing 101 is a light-emitting structure configured to emit additional LED light 12 and transmit LED filament light 11 during operation. Therefore, the light 13 includes one or more of LED filament light 11 and additional LED light 12.

[0044] Regarding CCT1, CCT2, and CCT3, CCT1 ≤ 2500K, 8000K ≥ CCT2 ≥ 3500K, and 2 ≥ LF1 / LF2 ≥ 0.5, where CCT1, CCT2, and LF1 / LF2 are chosen such that 3400K ≥ CCT3 ≥ 2600K.

[0045] like Figure 3 As shown, the LED filament light 11 may have first color points 301 and 302, and the additional LED light 12 may have second color points 303 and 304. In the CIE 1931 color space, the first color points 301 and 302 are closer to the blackbody locus (BBL) 350 than the second color points 303 and 304. For example, the second color points 303 and 304 may be at least 10 SDCM or at least 12 SDCM higher than the BBL 350.

[0046] In various embodiments, the LED filament light can have a color point within 7 SDCM of the BBL.

[0047] In various embodiments, I1 is greater than or equal to 10 times I2, and in various embodiments, LF2 is greater than LF1.

[0048] exist Figure 1a and Figure 1bIn the embodiment of the LED filament lamp 1 shown, the housing 101 includes a light guide. The light guide includes a light output device 103 and a light input surface 104. At least a portion of the additional LED light 12 is coupled into the light guide via the light input surface 104, and is guided through the housing 101 in the form of the light guide by total internal reflection, and then coupled out of the housing 101 in the form of the light guide via the light output device 103.

[0049] The transparent housing 101 should be light-scattering and have a reflectivity of less than 20%, preferably at least 7%. The inventors have discovered that with such reflectivity, the visibility of the LED filament is high, while providing sufficient additional LED light in a uniform manner by coupling additional LED light from the light guide.

[0050] The controller 120 can be configured to control one or more of CCT1, CCT2, LF1, LF2, I1, and I2. The controller can be configured to control CCT1, CCT2, LF1, LF2, I1, and I2 based on inputs from a user interface, a clock module, and / or sensors.

[0051] For example, such as Figure 4b As shown, the first correlated color temperature CCT1 of the LED filament light source 100 can be variable between a primary first correlated color temperature (CCT1a) 301 and a secondary first correlated color temperature (CCT1b) 302 that is different from the primary first correlated color temperature CCT1a 301, so that the third correlated color temperature CCT3 can be variable between a primary third correlated color temperature (CCT3a) 305 and a secondary third correlated color temperature (CCT3b) 306 that is different from the primary third correlated color temperature CCT3a 305.

[0052] Alternative sites (see) Figure 4c ) or additionally (see Figure 4a The second correlated color temperature CCT2 of the additional LED light source 102 can be variable between a primary second correlated color temperature (CCT2a) 303 and a secondary second correlated color temperature (CCT2b) 304 that is different from the primary second correlated color temperature CCT2a 303, so that the third correlated color temperature CCT3 can be variable between a primary third correlated color temperature (CCT3a) 305 and a secondary third correlated color temperature (CCT3b) 306 that is different from the primary third correlated color temperature CCT3a 305.

[0053] Figure 4b An example is illustrated where CCT1 is controlled to vary between CCT1a 301 and CCT1b 302, while CCT2 remains constant. As a result, CCT3 varies between CCT3a 305 and CCT3b 306.

[0054] Figure 4cAn example is illustrated where CCT2 is controlled to vary between CCT2a 303 and CCT2b 304, while CCT1 remains constant. As a result, CCT3 varies between CCT3a 305 and CCT3b 306.

[0055] In other embodiments, CCT1 and CCT2 are controlled to change simultaneously, such that CCT3 remains constant.

[0056] In another embodiment, the ratio LF1 / LF2 is controlled to vary, making CCT3 variable.

[0057] The following examples illustrate how the control of CCT1, CCT2, and the ratio LF1 / LF2 affects CCT3:

[0058] See also: Figure 2a and Figure 2b The LED filament light source 100 may include an array of multiple LEDs 141 disposed on a first main surface 143 of an elongated carrier 142. An elongated package 144 may at least partially cover the first main surface 143 and at least partially surround the multiple LEDs 141. Furthermore, additional LED light sources 102 may include a red LED light source 131, a green LED light source 132, and a blue LED light source 133.

[0059] Figure 5 An embodiment of a luminaire 500 is illustrated, which includes an LED filament lamp 1 as described herein, wherein the LED filament lamp 1 includes a connector 121 that is mechanically and electrically connected to a socket 501 of the luminaire 500.

Claims

1. A light-emitting diode (LED) filament lamp (1) configured to emit light (13) having a third correlated color temperature (CCT3) during operation, the LED filament lamp (1) comprising: - LED filament light source (100) is configured to emit LED filament light (11) having a first correlated color temperature CCT1, a first luminous intensity I1 and a first luminous flux LF1 during operation. - A transparent housing (101) at least partially surrounds the LED filament light source (100); the housing is light-scattering and has a reflectivity of less than 20%; - An additional LED light source (102) is configured to provide additional LED light (12) having a second correlated color temperature (CCT2), a second luminous intensity (I2), and a second luminous flux (LF2); wherein: - The additional LED light source (102) is configured to provide the additional LED light (12) to the housing (101). - The housing (101) includes a light-emitting structure (110) configured to emit the additional LED light (12) and transmit the LED filament light (11) during operation. - The housing (101) includes a light guide as the light-emitting structure (110), the light guide including a light output device (103) and a light input surface (104), wherein at least a portion of the additional LED light (12) is coupled into the light guide via the light input surface (104), and is guided through the light guide (101) by total internal reflection, and then coupled out of the light guide (101) via the light output device (103). - The light (13) includes the LED filament light (11) and the additional LED light (12); and - CCT1 ≤ 2500K, 8000K ≥ CCT2 ≥ 3500K and 2 ≥ LF1 / LF2 ≥ 0.5, where CCT1, CCT2, and LF1 / LF2 are chosen such that 3400K ≥ CCT3 ≥ 2600K, and The LED filament lamp further includes a controller (120) configured to control one or more of CCT1, CCT2, LF1, LF2, I1, and I2. CCT1 and CCT2 are both variable, allowing CCT3 to have a maximum variation of 300K.

2. The LED filament lamp (1) according to claim 1, wherein the housing has a reflectivity of at least 7%.

3. The LED filament lamp (1) according to claim 1 or 2, wherein I1 ≥ 10 I2.

4. The LED filament lamp (1) according to any one of the preceding claims, wherein LF2 > LF1.

5. The LED filament lamp (1) according to any one of the preceding claims, wherein the first correlated color temperature CCT1 of the LED filament light source (100) is variable between a primary first correlated color temperature CCT1a (301) and a secondary first correlated color temperature CCT1b (302) different from the primary first correlated color temperature CCT1a (301), such that the third correlated color temperature CCT3 is variable between a primary third correlated color temperature CCT3a (305) and a secondary third correlated color temperature CCT3b (306) different from the primary third correlated color temperature CCT3a (305).

6. The LED filament lamp (1) according to any one of the preceding claims, wherein the second correlated color temperature CCT2 of the additional LED light source (102) is variable between a primary second correlated color temperature CCT2a (303) and a secondary second correlated color temperature CCT2b (304) different from the primary second correlated color temperature CCT2a (303), such that the third correlated color temperature CCT3 is variable between a primary third correlated color temperature CCT3a (305) and a secondary third correlated color temperature CCT3b (306) different from the primary third correlated color temperature CCT3a (305).

7. The LED filament lamp (1) according to any one of the preceding claims, wherein the ratio LF1 / LF2 is variable, such that CCT3 is variable.

8. The LED filament lamp (1) according to any one of the preceding claims, wherein 2300K≥CCT1≥1700K, 5000K≥CCT2≥3500K, and 3300K≥CCT3≥2700K.

9. The LED filament lamp (1) according to any one of the preceding claims, wherein the additional LED light (12) has a second color point (303, 304) and the LED filament light (11) has a first color point (301, 302) which is closer to the blackbody locus BBL (350) in the International Commission on Illumination (CIE) 1931 color space than the second color point (303, 304).

10. The LED filament lamp (1) according to claim 9, wherein the second color point (303, 304) is at least 10 standard deviations (SDCM) higher than the BBL (350).

11. The LED filament lamp (1) according to any one of the preceding claims, wherein: - The LED filament light source (100) includes an array of a plurality of LEDs (141) arranged on a first main surface (143) of an elongated carrier (142), an elongated package that at least partially covers the first main surface (143) and at least partially surrounds the plurality of LEDs (141), and - The additional LED light source (102) includes a red LED light source (131), a green LED light source (132) and a blue LED light source (133).

12. A luminaire (500) comprising an LED filament lamp (1) according to any of the preceding claims, wherein the LED filament lamp (1) comprises a connector (121) mechanically connected to and electrically connected to a socket (501) of the luminaire (500).

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