RGB architecture for color controllable LED filament

Abstract

The invention provides a LED filament device (1000) configured to generate LED filament device light (1001), wherein the LED filament device (1000) comprises a LED filament (1100), wherein the LED filament (1100) comprises a plurality of light generating devices (100), each comprising a solid state light source (10), wherein the plurality of light generating devices (100) comprises a first set of n1 first light generating devices (110) configured to generate red first device light (111), a second set of n2 second light generating devices (120) configured to generate blue second device light (121), and a third set of n3 third light generating devices (130) configured to generate green third device light (131), wherein at least part of a total number n2 of the second light generating devices (120) of the second set are configured neighboring to first light generating devices (110) of the first set, wherein at least part of a total number n3 of the third light generating devices (130) of the third set are configured neighboring to first light generating devices (110) of the first set, wherein a total number n1 of the first light generating devices (110) is larger than the total number n2 of second light generating devices (120), wherein the total number n1 of the first light generating devices (110) is larger than a total number n3 of third light generating devices (130), wherein in a first operational mode the LED filament device (1000) is configured to generate filament device light (1001) having a correlated color temperature of at maximum 2500 K, wherein the filament device light (1001) comprises the red first device light (111) of the first set of n1 first light generating devices (110), the blue second device light (121) of the second set of n2 second light generating devices (120), and the green third device light (131) of the third set of n3 third light generating devices (130).

Claims

1. A LED filament device configured to generate LED filament device light, the LED filament device comprising: a LED filament having a plurality of light generating devices, each of the plurality of light generating devices having a solid state light source, the plurality of light generating devices having (i) a first set of n1 first light generating devices configured to generate red first device light, (ii) a second set of n2 second light generating devices configured to generate blue second device light, and (iii) a third set of n3 third light generating devices configured to generate green third device light, wherein at least part of a total number n2 of the second light generating devices of the second set are configured neighboring to first light generating devices of the first set, at least part of a total number n3 of the third light generating devices of the third set are configured neighboring to first light generating devices of the first set, a total number n1 of the first light generating devices is larger than the total number n2 of second light generating devices, and the total number n1 of the first light generating devices is larger than the total number n3 of third light generating devices, wherein in a first operational mode the LED filament device is configured to generate filament device light having a correlated color temperature of at maximum 2500 K, and the filament device light comprises the red first device light of the first set of n1 first light generating devices, the blue second device light of the second set of n2 second light generating devices, and the green third device light of the third set of n3 third light generating devices, wherein one or more of the second light generating devices of the second set of n2 second light generating devices are embedded in a light transmissive material and wherein the light transmissive material comprises a luminescent material configured to convert at least part of the second device light into luminescent material light, wherein the filament device light further comprises the luminescent material light, and wherein: (i) the light generating devices are configured in an elongated array comprising a single row, wherein the light generating devices are configured in a (R-R-G-B).sub.n array or a (R-G-R-B).sub.n array, wherein R refers to the first light generating devices, B refers to the second light generating devices, and G refers to the third light generating devices, wherein n refers to a number of repetitions, wherein n5, or (ii) the light generating devices are configured in an array comprising k rows, wherein k is selected from a range of 2-6, and wherein an array part of the array comprises at least four first light generating devices, at least two second light generating devices and at least two third light generating devices.

2. The LED filament device according to claim 1, wherein one or more of the following applies: (i) 2*n2n14*n2 and (ii) 2*n3n14*n3.

3. The LED filament device according to claim 1, wherein each of the first light generating devices of the first set have a shortest first mutual distance d1, and each of the second light generating devices of the second set have a shortest second mutual distance d2, wherein d2>d1.

4. The LED filament device according to claim 1, wherein in the first operational mode the LED filament device is configured to generate filament device light having a correlated color temperature selected from a range of 1900-2400 K.

5. The LED filament device according to claim 1, wherein the light generating devices are configured in the array comprising k rows in an [(RG)-(RB)].sub.n array or in a [(R)-(RG)-(R)-(RB)].sub.n array, wherein n2.

6. The LED filament device according to claim 1, wherein the light generating devices are configured in the array comprising k rows, wherein k is 2.

7. The LED filament device according to claim 6, wherein the first light generating devices are exclusively configured in one of the rows within the array part, and wherein the second light generating devices and third light generating devices are configured in another of the rows.

8. The LED filament device according to claim 7, wherein the light transmissive material comprises a plurality of luminescent materials configured to convert at least part of the second device light into luminescent material light.

9. The LED filament device according to claim 6, wherein the LED filament device comprises at least five array parts.

10. The LED filament device according to claim 6, comprising at least five repeating array parts, wherein each array part comprises 8 light generating devices, wherein n1=4, n2=2, n3=2, and wherein the first light generating devices in the array parts are exclusively configured in one of the rows and wherein at least part of the total number of the second light generating devices and the third light generating devices in the array part are configured in the other of the rows.

11. The LED filament device according to claim 6, wherein the light generating devices are configured in a [(RG)-(RB)].sub.n array or a [(R)-(RG)-(R)-(RB)].sub.n array, wherein R refers to the first light generating devices, B refers to the second light generating devices, G refers to the third light generating devices, wherein n refers to the number of repetitions, wherein (RG) refers to first light generating devices and third light generating devices in different rows, wherein (RB) refers to first light generating devices and second light generating devices in different rows, and wherein n5.

12. The LED filament device according to claim 1, wherein the LED filament device further comprises a control system configured to control one or more of a color point and a correlated color temperature of the filament device light by individually controlling the first set of n1 first light generating devices, the second set of n2 second light generating devices and the third set of n3 second light generating devices; and wherein the LED filament has a spiral shape or a helical shape.

13. The LED filament device according to claim 12, wherein the control system is configured to control in dependence of one or more of an input signal of a user interface, a sensor signal of a sensor, and a timer.

14. A lighting device, wherein the lighting device is a retrofit lamp comprising a light transmissive envelope enclosing at least part of the LED filament device according to claim 1.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) Embodiments of the invention will now be described, by way of example only, with reference to the accompanying schematic drawings in which corresponding reference symbols indicate corresponding parts, and in which:

(2) FIGS. 1a-1d schematically depict embodiments and some aspects; and

(3) FIG. 2 also shows an embodiment. The schematic drawings are not necessarily to scale.

DETAILED DESCRIPTION OF THE EMBODIMENTS

(4) FIG. 1a schematically depicts a number of embodiments of LED filament device 1000 configured to generate filament device light 1001. The LED filament device 1000 comprises a LED filament 1100.

(5) The LED filament 1100 comprises a plurality of light generating devices 100, each comprising a solid state light source 10. The solid state light source may be configured to generate solid state light source light. The light generating devices are especially configured to generate device light, which may consist of one or more of solid state light source light and converted solid state light source light. The latter may especially apply when the light generating devices comprises a luminescent material, i.e. wherein the light generating device may e.g. be a PC-LED. Reference 105 refers to a support for the light generating devices. In embodiments, the support 105 may comprise a flexible PCB.

(6) Reference L1 indicates the length of the LED filament 1100.

(7) Especially, the plurality of light generating devices 100 comprises a first set of n1 first light generating devices 110 configured to generate red first device light 111 and a second set of n2 second light generating devices 120 configured to generate blue second device light 121. In embodiments, at least part of a total number n2 of the second light generating devices 120 of the second set are configured neighboring to first light generating devices 110 of the first set.

(8) Further, in embodiments a total number n1 of the first light generating devices 110 is larger than the total number n2 of second light generating devices 120.

(9) Here, schematically five embodiments are shown, with on the left side a side view or cross-sectional view parallel to the length, and on the right side a view seen from one of the ends or a cross-sectional view parallel to the width. The squares at the extreme right, with the letters below, are a legends, indicating that the black squares refer to red emitting LEDs (R), open squares refer to white light emitting LEDs (only embodiments I and II) (W), the open squares in embodiments III-VI refer to blue emitting LEDs (B), and the hatched squares refer to green emitting LEDs (G).

(10) In embodiments I-III, n1=5 and in embodiments IV-V n1=4.

(11) In embodiments I-II, the number of other type of light generating devices, which may in specific embodiments be indicated as second light generating devices 120, is 3. These other light generating devices may e.g. be white light generating devices, like especially PC-LEDs.

(12) In embodiment III, the number of other type of light generating devices (which may be indicated as second light generating devices 120) is 3. Especially, in this embodiment the second light generating devices may be blue light generating devices see further below.

(13) In embodiments IV-V, there are 2 blue light generating devices, i.e. n2=2, and two green light generating devices, i.e. n3=2.

(14) In embodiments II and III the light generating devices 100 are embedded in an encapsulant 160. The encapsulant in embodiment II may represent an encapsulant 160 comprising light transmissive material 145 which may optionally comprise reflective particles, but which does essentially not comprise a luminescent material. The encapsulant in embodiment III may represent an encapsulant 160 comprising light transmissive material 145 which also comprises a luminescent material 200.

(15) Embodiments I and II may be based on a white+red principle, to provide warm white LED filament light 1001. Embodiment III may be based on a RB+luminescent material to provide warm white LED filament light 1001. Embodiments IV-V may be based on RGB to provide warm white LED filament light 1001.

(16) Hence, in a first operational mode the LED filament device 1000 may be configured to generate filament device light 1001 having a correlated color temperature of at maximum 2500 K, wherein (in the first operational mode) the filament device light 1001 comprises the red first device light 111 of the first set of n1 first light generating devices 110 and the blue second device light 121 of the second set of n2 second light generating devices 120.

(17) Referring to e.g. embodiments IV and V, the LED filament device 1000 is configured to generate filament device light 1001. As indicated above, the LED filament device 1000 comprises a filament 1100. Especially, the filament 1100 comprises a plurality of light generating devices 100, each comprising a solid state light source 10. The plurality of light generating devices 100 comprises a first set of n1 first light generating devices 110 configured to generate red first device light 111, a second set of n2 second light generating devices 120 configured to generate blue second device light 121, and a third set of n3 third light generating devices 130 configured to generate green third device light 131. Especially, at least part of a total number n2 of the second light generating devices 120 of the second set are configured neighboring to first light generating devices 110 of the first set. Further, especially at least part of a total number n3 of the third light generating devices 130 of the third set are configured neighboring to first light generating devices 110 of the first set. Further, as indicated above, in embodiments a total number n1 of the first light generating devices 110 is larger than the total number n2 of second light generating devices 120. Yet further, as indicated above, in embodiments the total number n1 of the first light generating devices 110 is larger than a total number n3 of third light generating devices 130. Further, as indicated above in embodiments in a first operational mode the LED filament device 1000 is configured to generate filament device light 1001 having a correlated color temperature of at maximum 2500 K. Especially, in embodiments (in the first operational mode) the filament device light 1001 comprises the red first device light 111 of the first set of n1 first light generating devices 110, the blue second device light 121 of the second set of n2 second light generating devices 120, and the green third device light 131 of the third set of n3 third light generating devices 130.

(18) Referring to embodiments I-VI, one or more of the following applies: (i) 2*n2n14*n2 and (ii) 2*n3n14*n3. Referring to embodiments IV and V, also n1/(n2+n3)1 may apply.

(19) In embodiments, in the first operational mode the LED filament device 1000 is configured to generate filament device light 1001 having a correlated color temperature selected from the range of 1900-2400 K.

(20) In specific embodiments, each of the first light generating devices 110 of the first set (of n1 first light generating devices 110) are configured to generate first device light 111 having a color point with an CIE x value of at least 0.48 and a CIE y value of at maximum 0.45 (and at minimum 0.35).

(21) As indicated above, referring to embodiments II, III, and V, one or more of the second light generating devices 120 of the second set (of n2 second light generating devices 120) are embedded in a light transmissive material 145.

(22) Referring to embodiment III, the light transmissive material 145 may comprise a luminescent material 200 configured to convert at least part of the second device light 121 into luminescent material light 201, wherein the filament device light 1001 comprises the red first device light 111 of the first set of n1 first light generating devices 110, the blue second device light 121 of the second set of n2 second light generating devices 120, and the first luminescent material light 201.

(23) Referring to embodiments I-III, and also other embodiments described and/or schematically depicted herein, the invention may in embodiments provide a light-emitting device (herein especially indicated as LED filament device (1000)) comprising: an elongated bar-shaped package with left and right ends, the package being formed such that a plurality of leads are formed integrally with a first resin with part of the leads exposed; a light-emitting element that is fixed onto at least one of the leads and that is electrically connected to at least one of the leads; and a second resin sealing the light-emitting element, wherein the leads are formed of metal, an entire bottom surface of the light-emitting element is covered with at least one of the leads, an entire bottom surface of the package is covered with the first resin, the first resin has a side wall that is integrally formed with a portion covering the bottom surface of the package and that is higher than upper surfaces of the leads, the first resin and the second resin are formed of optically transparent resin, the second resin that is filled to a top of the side wall of the first resin and that includes a fluorescent material having a larger specific gravity than that of the second resin, the leads have outer lead portions that are used for external connection and that protrude in a longitudinal direction of the package from the left and right ends wherein the fluorescent material is arranged to concentrate near the light emitting element, and is excited by part of light emitted by the light-emitting element so as to emit a color different from a color of the light emitted by the light-emitting element, and the side wall transmits part of light that is emitted by the light-emitting element and that enters the side wall and part of light emitted from the fluorescent material to the portion covering the bottom surface of the package.

(24) FIG. 1b schematically depicts a view seen from one of the ends or a cross-sectional view parallel to the width of the filament 1100. The embodiment numbers in FIG. 1b do not necessarily match with the embodiment number in FIG. 1a.

(25) Embodiment I indicates a light generating device 100, which may e.g. be in embodiments a red LED or a blue LED or a green LED; though other embodiments may also be possible. A single row 206 is shown. Hence, an array 205 of a single row 206 is schematically depicted in embodiment I of FIG. 1b.

(26) Embodiment II indicates a light generating device 100, which may e.g. be in embodiments a red LED or a blue LED or a green LED; though other embodiments may also be possible. A single row 206 is shown. Hence, an array 205 of a single row 206 is schematically depicted in embodiment II of FIG. 1b. The light generating device 100 is embedded in an encapsulant 160.

(27) Embodiment III indicates two light generating devices 100, which may e.g. be in embodiments individually be selected from a red LED or a blue LED and a green LED; though other embodiments may also be possible. Two rows 206 are shown. Hence, an array 205 of two rows 206 is schematically depicted in embodiment III of FIG. 1b.

(28) Embodiment IV indicates two light generating devices 100, which may e.g. be in embodiments individually be selected from a red LED or a blue LED and a green LED; though other embodiments may also be possible. Two rows 206 are shown. Hence, an array 205 of two rows 206 is schematically depicted in embodiment IV of FIG. 1b. One of the light generating devices 100 is embedded in an encapsulant 160. Hence, in embodiments a single row, or part thereof, may be encapsulated.

(29) Embodiment V indicates two light generating devices 100, which may e.g. be in embodiments individually be selected from a red LED or a blue LED and a green LED; though other embodiments may also be possible. Two rows 206 are shown. Hence, an array 205 of two rows 206 is schematically depicted in embodiment IV of FIG. 1b. Both light generating devices 100 are embedded in an encapsulant 160. Hence, in embodiments both rows (or parts thereof) may be encapsulated.

(30) Embodiment VI indicates three light generating devices 100, which may e.g. be in embodiments individually be selected from a red LED or a blue LED and a green LED; though other embodiments may also be possible. Three rows 206 are shown. Hence, an array 205 of three rows 206 is schematically depicted in embodiment IV of FIG. 1b. Of course, in specific embodiments, herein not depicted, one or more of the rows (or parts thereof) may be encapsulated.

(31) Embodiment VII indicates an embodiment wherein at both sides of the support 105 light generating devices may be configured.

(32) Of course, combinations of embodiments may also be possible.

(33) FIG. 1c schematically depict a number of embodiments A-H, based on the RGB principle. However, other solutions may also be possible. Here, also black squares refer to red emitting LEDs, the open squares in embodiments refer to blue emitting LEDs, and the hatched squares refer to green emitting LEDs.

(34) In embodiments A, the embodiment does not comply with one of the conditions wherein (a) a total number n1 of the first light generating devices 110 is larger than the total number n2 of second light generating devices 120, and (b) the total number n1 of the first light generating devices 110 is larger than a total number n3 of third light generating devices 130. Embodiments B-H all comply with one or both of these conditions. Embodiment A shows a 1D array 205 (RGB).sub.n, with the top light generating device being a first light generating device (for generating red light), with n=6.

(35) Referring to one or more of the embodiments depicted in FIG. 1c, embodiments are schematically depicted wherein each of the first light generating devices 110 of the first set (of n1 first light generating devices 110) have a shortest first mutual distance d1, and each of the second light generating devices 120 of the second set (of n2 second light generating devices 120) have a shortest second mutual distance d2, wherein d2>d1.

(36) In embodiments, the plurality of light generating devices 100 comprises a third set of n3 third light generating devices 130 configured to generate green third device light 131. Especially, a total number n1 of the first light generating devices 110 is larger than a total number n3 of third light generating devices 130.

(37) As indicated above, in the first operational mode the filament device light 1001 may comprise the red first device light 111 of the first set of n1 first light generating devices 110, the blue second device light 121 of the second set of n2 second light generating devices 120, and the green third device light 131 of the third set of n3 third light generating devices 130.

(38) Referring to e.g. embodiments B-C in FIG. 1c, the light generating devices 100 are configured in an elongated array 205 comprising a single row 206. Especially, in embodiments the light generating devices are configured in a (R-R-G-B).sub.n or (R-G-R-B).sub.n array. Here, R refers to the first light generating devices 110, B refers to the second light generating devices 120, G refers to the third light generating devices 130, and n refers to the number of repetitions. For instance, in embodiments wherein n5 (note that in FIG. 1c smaller number of n are depicted for the sake of economy).

(39) In embodiments, the light generating devices 100 are configured in an array 205 comprising k rows 206, wherein k=2, see e.g. embodiments D-H in FIG. 1c.

(40) Referring to embodiments D-H in FIG. 1c, an array part 207 of the array 205 may comprise at least four first light generating devices 110, at least two second light generating devices 120 and at least two third light generating devices 130. Especially, the array part 207 may have a configuration wherein at least one of (i) the first light generating devices 110 in the array part 207, (ii) the second light generating devices 120 in the array part 207, and (iii) the third light generating devices 130 in the array part 207, are exclusively configured in one of the arrays 205 within the array part 207.

(41) Referring to embodiments F-H in FIG. 1c, in embodiments the first light generating devices 110 are exclusively configured in one of the rows 206 within the array part 207, and the second light generating devices and third light generating devices in the second row.

(42) Referring to embodiments F-H in FIG. 1c, the LED filament device 1000 may comprising q repeating array parts 207. In specific embodiments, each array part 207 may comprise 8 light generating devices 100, wherein n1=4, n2=2, n3=2. The first light generating devices 110 in the array parts 207 are exclusively configured in one of the rows 206 and at least part of the total number of the second light generating devices 120 and the third light generating devices 130 in the array part 207 are configured in the other of the rows 206. The value of q may be at least 5, but for the sake of economy, smaller values are depicted in embodiments F-H in FIG. 1c. Hence, in specific embodiments the light generating devices may be configured in a [(RG)-(RB)].sub.n array or in a [(R)-(RG)-(R)-(RB)].sub.n, wherein R refers to the first light generating devices (110), B refers to the second light generating devices (120), G refers to the third light generating devices (130), wherein n refers to the number of repetitions, wherein (RG) refers to first light generating devices (110) and third light generating devices (130) in different rows, wherein (RB) refers to first light generating devices (110) and second light generating devices (120) in different rows. Especially, in embodiments n2, like n4, more especially n5.

(43) In B, the array is an (RRBG).sub.n 1D array, with n is at least 4, and starting with the first two light generating devices at the top being first light generating devices.

(44) In C, the array is an (RBRG).sub.n 1D array, with n is at least 4, and starting with the light generating device at the top being a first light generating device.

(45) In D, the array is a 2D, with the first row a 1D array (BRR).sub.n, and the second row only green third light generating devices, but with a larger pitch. The first row starts with the top light generating device at the top being a second light generating device.

(46) In E, the array is a 2D, with the first row a 1D array (GRR).sub.n, and the second row only blue third light generating devices, but with a larger pitch. The first row starts with the top light generating device at the top being a third light generating device.

(47) In F, the array is a 2D, with the first row only first light generating devices, and the second row a 1D array (BG).sub.n. The second row starts with the first light generating device at the top being a second light generating device.

(48) In G, the array is a 2D, with the first row only first light generating devices, and the second row a 1D array (BG).sub.n, however having a larger pitch. The second row starts with the first light generating device at the top being a second light generating device.

(49) In H, the array is a 2D, with in each array part 207 one of the rows only first light generating devices, and the other of the rows a 1D array (BG).sub.n or (GB).sub.n.

(50) Referring to FIG. 1d, in embodiments the LED filament device 1000 may further comprise a control system 300 configured to control a color point of the filament device light 1001, or the control system 300 may be functionally coupled to the LED filament device 1000.

(51) FIG. 1d also schematically depicts an embodiment of a lighting device 1200, comprising the LED filament device 1000. The lighting device 1200 may be a retrofit lamp. Further, an embodiment is depicted wherein the filament 1100 has a spiral shape or a helical shape.

(52) FIG. 2 schematically depicts an embodiment of an application of the LED filament device 1000 and/or the lighting device 1200. The lighting device light is indicated with reference 1201, which may consist of the filament device light 1001 (of one or more LED filament devices 1000). Reference 301 refers to an optional user interface and reference 300 refers to an optimal control system for controlling the light generating device(s).

(53) The term plurality refers to two or more. The terms substantially or essentially herein, and similar terms, will be understood by the person skilled in the art.

(54) The terms substantially or essentially may also include embodiments with entirely, completely, all, etc. Hence, in embodiments the adjective substantially or essentially may also be removed. Where applicable, the term substantially or the term essentially may also relate to 90% or higher, such as 95% or higher, especially 99% or higher, even more especially 99.5% or higher, including 100%. The term comprise also includes embodiments wherein the term comprises means consists of.

(55) The term and/or especially relates to one or more of the items mentioned before and after and/or. For instance, a phrase item 1 and/or item 2 and similar phrases may relate to one or more of item 1 and item 2. The term comprising may in an embodiment refer to consisting of but may in another embodiment also refer to containing at least the defined species and optionally one or more other species.

(56) Furthermore, the terms first, second, third and the like in the description and in the claims, are used for distinguishing between similar elements and not necessarily for describing a sequential or chronological order.

(57) The devices, apparatus, or systems may herein amongst others be described during operation. As will be clear to the person skilled in the art, the invention is not limited to methods of operation, or devices, apparatus, or systems in operation.

(58) In the claims, any reference signs placed between parentheses shall not be construed as limiting the claim.

(59) Use of the verb to comprise and its conjugations does not exclude the presence of elements or steps other than those stated in a claim. Unless the context clearly requires otherwise, throughout the description and the claims, the words comprise, comprising, and the like are to be construed in an inclusive sense as opposed to an exclusive or exhaustive sense; that is to say, in the sense of including, but not limited to.

(60) The article a or an preceding an element does not exclude the presence of a plurality of such elements.

(61) The invention may be implemented by means of hardware comprising several distinct elements, and by means of a suitably programmed computer. In a device claim, or an apparatus claim, or a system claim, enumerating several means, several of these means may be embodied by one and the same item of hardware.

(62) The invention also provides a control system that may control the device, apparatus, or system, or that may execute the herein described method or process. Yet further, the invention also provides a computer program product, when running on a computer which is functionally coupled to or comprised by the device, apparatus, or system, controls one or more controllable elements of such device, apparatus, or system.

(63) The invention further applies to a device, apparatus, or system comprising one or more of the characterizing features described in the description and/or shown in the attached drawings.

(64) The various aspects discussed in this patent can be combined in order to provide additional advantages. Further, the person skilled in the art will understand that embodiments can be combined, and that also more than two embodiments can be combined. Furthermore, some of the features can form the basis for one or more divisional applications.