LED lamp

Abstract

An LED lamp includes a lamp base for insertion into a reflector of an automotive front lighting assembly; a panel extending from the lamp base with a first vertical side facing into one half of the reflector and a second vertical side facing into the other half of the reflector; a primary light source including a set of LED dies on each vertical side of the panel; a two-part shield including a first shield half shielding the LED dies on the first vertical side of the panel and a second shield half shielding the LED dies on the second vertical side of the panel. The two-part shield essentially has the form of a shield in a functionally equivalent filament lamp for providing a low beam. A lighting arrangement includes such an LED lamp; a reflector to receive the lamp; and an electrical interface for connecting to a controller.

Claims

1. An LED lamp for installation in an automotive front lighting assembly, comprising: a lamp base configured to be insertable into a reflector of the automotive front lighting assembly; a panel extending outward from the lamp base, the panel comprising a first side and a second side oppositely positioned from the first side; a primary light source configured to produce a low beam, the primary light source comprising a first set of primary LED dies disposed on the first side of the panel and a second set of primary LED dies disposed on the second side of the panel; a two-part shield comprising a first part arranged to shield the first set of primary LED dies and a second part arranged to shield the second set of primary LED dies, the first part arranged asymmetrically with the second part about the panel; and a secondary light source configured to produce a high beam, the secondary light source comprising a first set of secondary LED dies disposed on the first side of the panel and a second set of secondary LED dies disposed on the second side of the panel.

2. The LED lamp according to claim 1, wherein the first and second sets of primary LED dies of the primary light source comprises an array of three primary LED dies.

3. The LED lamp according to claim 1, wherein the first and second sets of secondary LED dies of the secondary light source comprises an array of at least two secondary LED dies.

4. The LED lamp according to claim 1, further comprising an anti-glare cap disposed to have the panel between the anti-glare cap and the lamp base.

5. The LED lamp according to claim 1, comprising a driver incorporated in the lamp base.

6. An automotive front lighting arrangement comprising the LED lamp according to claim 1; the reflector to receive the LED lamp; and an electrical interface for connecting to a controller of the automotive front light arrangement.

7. The automotive front lighting arrangement according to claim 6, wherein the driver of the LED lamp is configured to activate the primary LED dies of the primary light source to generate the low beam, and to activate the primary LED dies of the secondary light source to generate a high beam, in response to a signal from the controller.

8. The automotive front lighting arrangement according to claim 7, wherein the driver is configured to activate a primary LED die of the primary light source in addition to the secondary LED dies of the secondary light source to generate the high beam.

9. The automotive front lighting arrangement according to claim 7, wherein the primary LED die of the primary light source to be activated by the driver in addition to the secondary LED dies of the secondary light source to generate the high beam is a primary LED die of the primary light source closest to the secondary light source.

10. The automotive front lighting arrangement according to claim 6, comprising a heat dissipating part connected to the lamp base of the LED lamp to achieve thermal connection to the panel.

11. The automotive front lighting arrangement according to claim 10, wherein the heat dissipating part comprises a plurality of fins.

12. The LED lamp according to claim 1, wherein the LED dies within the first and second sets of LED dies of the primary light source are arranged in a row.

13. The LED lamp according to claim 1, wherein the LED dies within the first and second sets of LED dies of the secondary light source are arranged in a row.

14. The LED lamp according to claim 1, wherein the first and second sets of LED dies of the primary light source each comprises three LED dies arranged in a row.

15. The LED lamp according to claim 1, wherein the two-part shield spans an arc of less than 180° with respect to a horizontal plane perpendicular to a first direction, the panel has a height along a first direction and a length along a second direction perpendicular to the first direction and extending outward from the lamp base, the second direction parallel to the horizontal plane.

16. The LED lamp according to claim 1, wherein one of the first part and the second part of the two-part shield is lower than the other by an angle of 15° subtended from the horizontal plane.

17. An LED lamp for installation in an automotive front lighting assembly, comprising: a lamp base configured to be insertable into a reflector of the automotive front lighting assembly; a panel extending outward from the lamp base, the panel comprising a first side and a second side oppositely positioned from the first side; a primary light source configured to produce a low beam, the primary light source consisting of three primary LED dies disposed on the first side of the panel and of three primary LED dies disposed on the second side of the panel; a two-part shield comprising a first part arranged to shield the three primary LED dies disposed on the first side of the panel and a second part arranged to shield the three primary LED dies disposed on the second side of the panel; and a secondary light source configured to produce a high beam, the secondary light source consisting of three or less secondary LED dies disposed on the first side of the panel and three or less secondary LED dies disposed on the second side of the panel.

18. The LED lamp according to claim 17, wherein the three or less secondary LED dies disposed on the first side of the panel consists of two secondary LED dies, and the three or less secondary LED dies disposed on the second side of the panel consists of two secondary LED dies.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 shows a perspective side view of an embodiment of the inventive LED lamp;

(2) FIG. 2 shows a plan view of the embodiment of FIG. 1;

(3) FIG. 3 shows a cross-section through an embodiment of the inventive lamp;

(4) FIG. 4 illustrates generation of a low beam for an embodiment of the inventive LED lamp;

(5) FIG. 5 illustrates generation of a high beam for the LED lamp of FIG. 4;

(6) FIG. 6 illustrates generation of a low beam for a further embodiment of the inventive LED lamp;

(7) FIG. 7 illustrates generation of a high beam for the LED lamp of FIG. 6;

(8) FIG. 8 shows a prior art H4 halogen lamp;

(9) FIG. 9 shows an embodiment of the inventive lamp arranged in a reflector.

(10) In the drawings, like numbers refer to like objects throughout. Objects in the diagrams are not necessarily drawn to scale.

DETAILED DESCRIPTION OF THE EMBODIMENTS

(11) FIG. 1 shows an embodiment of the inventive LED lamp 1 realized as a retrofit lamp to replace a conventional or legacy halogen two-filament lamp (as described in FIG. 8 below). The diagram illustrates the similarity in shape to the legacy lamp 8 of FIG. 8. The lamp body is similar in shape and proportion to the glass vessel of the legacy lamp 8, and comprises a panel 10 extending outward from a lamp base 12 and arranged such that a first vertical side 10A will face into one half of a reflector (not shown) and a second vertical side 10B will face into the other half of the reflector. The lamp base 12 is realized for insertion into the reflector 20 of an automotive front lighting assembly and comprises a number of tabs 14 that aid in correct positioning of the lamp 1 in the reflector. In this exemplary embodiment, the lamp base 12 terminates in a connector that is inserted into a corresponding connector 131 extending from a heat sink 13. A driver for the LEDs 100, 101 can be incorporated into the lamp base 12 or, alternatively, in the connector 131. When inserted into the reflector, the panel 10 will be in thermal contact with the heat sink 13, which can efficiently dissipate the heat generated by the LEDs during operation. An anti-glare cap 15 is arranged towards the front end of the lamp 1 in keeping with the regulation applicable to the legacy lamp, and is held in place by a cap mount 150 extending between the cap 15 and the lamp base 12. FIG. 2 shows a plan view of the same lamp 1, and omits a part of the cap mount 150 for clarity.

(12) The filaments of the legacy lamp are mimicked by sets of LEDs. To this end, a primary light source P, which will be used to generate a low beam, comprises a set PA, PB of LED dies 100 on each vertical side 10A, 10B of the panel 10. In FIG. 1, only one set PA is visible, arranged on one side 10A of the panel 10. The other set PB is arranged on the other side 10B of the panel 10 and can be seen in FIG. 2. The positions of the primary light source LED sets PA, PB are such to mimic the position of a low-beam filament 81 in the lamp 8 described in FIG. 8. A two-part shield 11 comprises a first shield half 11A arranged to shield the LED set PA on the first vertical side 10A of the panel 10, and a second shield half 11B that is arranged to shield the other LED set PB. The two-part shield 11 has the same size and shape as the shield 83 of the legacy lamp 8 described in FIG. 8.

(13) The LED lamp 1 also has a secondary light source S to generate a high beam, with a set SA, SB of LED dies 101 on each vertical side 10A, 10B of the panel 10. Again, only one set SA is visible in FIG. 1, and the other set SB arranged on the other side 10B of the panel 10 can be seen in FIG. 2. The positions of the secondary LED sets SA, SB are such to mimic the position of a high-beam filament 82 in the lamp 8 described in FIG. 8. The number of LED dies in each set PA, PB, SA, SB is chosen to achieve the desired lumen output, which should correspond to the lumen output of the legacy lamp.

(14) To correctly mimic the long or rectangular shape of a filament, each LED die set PA, PB, SA, SB consists of several LED dies 100, 101 arranged in a row. In this embodiment, each filament is mimicked by a linear arrangement of three LEDs 100, 101. The LED die rows are arranged to correspond to the positions of the filaments in the vessel of the legacy lamp. FIG. 1 shows that the row PA of low beam LED dies 100 is slightly higher than the row SA of high-beam LED dies 101.

(15) FIG. 3 shows a cross-section through an embodiment of the inventive lamp 1, looking in the direction of the lamp base. The cross-section is taken vertically through one of the LEDs 100 of the primary light source P. The diagram shows the panel 10, which can be a suitable carrier 10 such as a printed circuit board (PCB) in which tracks are formed to electrically connect to the LEDs 100 mounted on either side 10A, 10B of the panel 10. A shield half 11A is mounted to one side 10A of the panel 10, and a complementary shield half 11B is mounted to the other side 10B of the panel 10. The shield halves 11A, 11B are shown to act collectively as a comparable shield of a legacy lamp as shown in FIG. 8. The shield spans an arc of less than 180°, so that one side is lower by an angle β subtended from a horizontal plane H that contains the focal line of the reflector (not shown). For a H4 lamp, for example, this angle β will comprise 15° so that the shield 11 spans an arc of 165°. The LEDs 100 of the primary light source PA, PB are arranged on the panel 10 to lie in the position that would be occupied by the corresponding filament of the legacy lamp.

(16) FIGS. 4-7 illustrate how a low beam or a high beam might be generated for different embodiments of the inventive LED lamp. In the diagrams, LED sets PA, SA on one side only of the panel 10 are shown, and it may be assumed that the LED sets PB, SB on the other side of the panel 10 are activated/deactivated in the same manner. A simplified outline of the shield half 11A is indicated by a dashed line. In FIG. 4, a low beam is being generated using the LEDs 100 of the primary light source P, as indicated by the hatching fill pattern. The LEDs 101 of the secondary light source are not turned on (in response to a user's action to turn on only the low beam). In FIG. 5, a high beam is being generated using the LEDs 101 of the secondary light source, as indicated by the hatching fill pattern. The LEDs 100 of the primary light source are not turned on. FIG. 4 and FIG. 5 relate to the same embodiment of the inventive LED lamp. FIG. 6 and FIG. 7 relate to an alternative embodiment of the inventive LED lamp. In FIG. 6, a low beam is being generated using the LEDs 100 of the primary light source, as indicated by the hatching fill pattern. The LEDs 101 of the secondary light source are not turned on. In this embodiment, the secondary light source comprises an array of only two LEDs 101 on each side of the panel 10, and “borrows” an LED 100 of each set of the primary light source P. In FIG. 7, a high beam is being generated using one of the LEDs 100 of the primary light source P in addition to the LEDs 101 of the secondary light source S, as indicated by the hatching fill pattern. The other two LEDs 100 of the primary light source are not turned on. It is of course possible to turn on both low beam and high beam simultaneously for the embodiment shown in FIGS. 4 and 5 and the embodiment shown in FIGS. 6 and 7.

(17) FIG. 8 shows a halogen lamp 8 that combines low beam and high beam functions. Examples of such filament lamps are H4, HS1, H13, H17, H19 etc. The lamp 8 comprises a glass vessel 80 filled with a halogen gas. Two filaments 81, 82 and a shield 83 are arranged inside the vessel 80. An anti-glare cap 84 at the front of the vessel 80 shields oncoming traffic from glare. The filaments 81, 82 as well as the shield 83 are geometrically arranged in standardized positions in order to be able to operate correctly in a reflector that is part of a car headlamp. The cup-shaped form and the edges of the shield 83 play a significant role in correctly shielding the low beam filament 81, preventing its light from entering the dedicated high beam region of the reflector. The lamp 8 has a standardized form with three tabs to ensure correct positioning when the lamp 8 is mounted into the headlamp reflector.

(18) FIG. 9 shows a H4-type LED lamp 1 arranged in a reflector 20 of an automotive front lighting unit. The diagram serves to show that the reflector 20 is designed for use with a legacy H4 two-filament halogen lamp (such as that shown in FIG. 8) but instead a suitable embodiment of the inventive LED lamp 1 is inserted into the reflector 20. The same controller 3 is used to activate/deactivate the low and high beams in response to a user's actions.

(19) Here, the position of the primary light source P corresponds to the position of the low-beam filament 81 of the legacy halogen lamp; the position of the secondary light source S corresponds to the position of the high-beam filament 82 of the legacy lamp; and the shield 11 corresponds in shape and position to the shield 83 of the legacy lamp. The LEDs of the primary and secondary light sources P, S can be controlled collectively or individually as explained above by means of the controller 3. The controller 3 is electrically connected to a driver arranged in the base of the lamp 1 by means of leads 30, 31 extending through the heat sink 13 to reach the standard connector terminals at the lamp base 12. The lamp connector and base 12 can have the standardized form as shown in FIG. 8.

(20) Although the present invention has been disclosed in the form of preferred embodiments and variations thereon, it will be understood that numerous additional modifications and variations could be made thereto without departing from the scope of the invention.

(21) For the sake of clarity, it is to be understood that the use of “a” or “an” throughout this application does not exclude a plurality, and “comprising” does not exclude other steps or elements.

LIST OF REFERENCE SIGNS

(22) LED lamp 1 panel 10 vertical side 10A, 10B two-part shield 11 shield halves 11A, 11B lamp base 12 heat sink 13 fins 130 connector 131 tab 14 glare cap 15 cap mount 150 reflector 20 controller 3 leads 30, 31 filament lamp 8 lamp vessel 80 filaments 81, 82 shield 83 anti-glare cap 84 primary/secondary light source P, S LED arrays PA, PB, SA, SB LEDs 100, 101 horizontal plane H angle β