Current supply for luminescent diodes

• US 20060284865A1
• Filed: 07/14/2006
• Published: 12/21/2006
• Est. Priority Date: 07/04/2002
• Status: Active Grant

• Current Assignee: Knobel AG Lichttechnische Komponenten, Tridonic Optoelectronics GmbH
• Original Assignee: Knobel AG Lichttechnische Komponenten, Tridonic Optoelectronics GmbH
• Inventors: Zimmermann, Michael, Tasch, Stefan, Tobler, Felix
• Granted Patent: US 7,708,447 B2
• Time in Patent Office: Days
• US Class Current: 345/214
• CPC Class Codes: H05B 45/10 Controlling the intensity of the light
• CPC Class Codes: H05B 45/36 Circuits for reducing or suppressing harmonics, ripples or electromagnetic interferences [EMI]
• CPC Class Codes: H05B 45/375 using buck topology
• CPC Class Codes: H05B 45/382 with galvanic isolation between input and output
• CPC Class Codes: H05B 45/56 involving measures to prevent abnormal temperature of the LEDs
• CPC Class Codes: Y02B 20/30 Semiconductor lamps, e.g. solid state lamps [SSL] light emitting diodes [LED] or organic LED [OLED]

Abstract

The present invention is based on a regulation circuit (200a, 200b) for making available a constant current supply on the basis of a transformer principle, in which there flows through the luminescent diodes (D1, . . . ,DN) a triangular a.c. current (I_D) varying periodically around a d.c. current value. With this method it is afforded by means of a circuitry provision that both the charging and also the discharging current (I_L1) of an inductive reactance (X_L1) connected in series to the luminescent diodes (D1, . . . ,DN), functioning as a storage choke (L1) for filtering of mains harmonics, flows as diode current (I_D) through the luminescent diodes (D1, . . . ,DN). The advantage of this method consists in a significant reduction of the overall power loss (P_V,ges) of the LED illumination module (100). According to one exemplary embodiment of the invention the ceramic circuit board (102) of the LED illumination module (100) in accordance with the invention has a direct mains current supply (104, 108), which for protection from mechanical damage is accommodated in a transparent housing (106) having a highly transparent polymer mass (110) serving as optically active lens surface.

Claims

1-13. -13. (canceled)

14. A LED module, comprising an arrangement of series connected light-emitting diodes, which are applied on a thermally conducting ceramic circuit board with direct mains current supply and are fed via a current supply mains with a.c. current, wherein

the LED illumination module is, for protection from mechanical damage, accommodated in a transparent housing, having a highly transparent polymer mass, serving as optically active lens surface, and has a regulation circuit for providing a constant current supply, and

the light emitting p- and n-doped layers of the luminescent diodes are applied to the said circuit board in a Chip-On-Board technology.

15. The LED module of claim 14,

wherein Fresnel lenses in the form of a lens plate for the attainment of a bundled homogenous light distribution in the region of the main emission directions are positioned centrally above each luminescent diode within the transparent housing.

16. The LED module of claim 14,

wherein holes are applied to the circuit board in order to avoid the formation of air bubbles on the side on which the luminescent diodes are applied, upon molding of the highly transparent polymer mass within the housing.

17. The LED module of claim 14,

wherein the inner sides of the transparent housing, with the exception of the light emitting region, are of a thermally good conducting material, which on the outer side for heat discharge is covered over with an electrically non-conducting material.

18. The LED module of claim 14,

wherein the polymer mass is of a thermally good conducting material which acts in an electrically insulating manner.

19. The LED module of claim 14,

wherein the transparent housing can be contacted with the aid of a plug, socket and/or connection cable led out of the housing to the side.

20. The LED module of claim 14,

wherein around each individual luminescent diode, formed as LED die, there is a parabolic or funnel-shaped reflector of a reflector plate, of a thermally good conducting, highly reflecting material, which is electrically insulated on the underside, placed from above on the circuit board.

21. The LED module according to claim 20,

wherein each individual reflector is of a plastic with mirrored inner side.

22. The LED module of claim 14,

wherein the rear side of the circuit board is coupled to a cooling body which serves for the transfer of the discharge heat arising upon operation of the LED illumination module to the housing or a mounting.

23. A method for producing the module of claim 14,

wherein the unhoused luminescent diodes of the LED illumination module are molded directly with the highly transparent polymer mass within an injection molding process and/or by means of a casting process.

24. A method for producing the module of claim 14,

wherein light of white color tone is generated with the aid of a color conversion medium, which is added to the polymer mass in the region of the main emission direction above the position of monochromatic photon emission of the luminescent diodes emitting in the spectral range of the color blue.