Current supply for luminescent diodes

• US 7,708,447 B2
• Filed: 07/14/2006
• Issued: 05/04/2010
• Est. Priority Date: 07/04/2002
• Status: Expired due to Fees

• Current Assignee: Knobel AG Lichttechnische Komponenten, Tridonic Optoelectronics GmbH
• Original Assignee: Knobel AG Lichttechnische Komponenten, Tridonic Optoelectronics GmbH
• Inventors: Tobler, Felix, Zimmerman, Michael, Tasch, Stefan
• Primary Examiner(s): Owens; Douglas W
• Assistant Examiner(s): A; Minh D
• Application Number:
  US11/486,103
• Publication Number:
  US 20060284865A1
• Time in Patent Office: 1,390 Days
• Field of Search: 315/291, 315/307, 315/224, 315/244, 362/616, 362/629, 362/632, 362/555, 362611-614, 362/362
• US Class Current: 362/619
• 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 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 varying periodically around a DC current value. Both a charging and a discharging current of inductive reactance connected in series to the luminescent diodes (D 1, . . . , DN), functioning as a storage choke for filtering of mains harmonics, flows as diode current through the luminescent diodes (D 1, . . . , DN). According to one exemplary embodiment of the invention the ceramic circuit board of the LED illumination module in accordance with the invention has a direct mains current supply, which for protection from mechanical damage is accommodated in a transparent housing having a highly transparent polymer mass serving as optically active lens surface.

Claims

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

the LED module is, for protection from mechanical damage, enclosed between a transparent housing and the circuit board, the transparent housing having a highly transparent polymer mass disposed therein, serving as an optically active lens surface, and has a regulation circuit for providing a constant current supply, and light-emitting p- and n-doped layers of the luminescent diodes are applied to the circuit board using a Chip-On-Board technology, wherein Fresnel lenses that include a lens plate for attainment of a bundled homogenous light distribution in a region of main emission directions are positioned centrally above each luminescent diode within the transparent housing.

2. The LED module of claim 1, wherein holes are formed in the circuit board in order to avoid forming air bubbles on a side on which the luminescent diodes are applied, upon molding of the highly transparent polymer mass within the housing.

3. The LED module of claim 1, wherein inner sides of the transparent housing, except a light emitting region thereof, are formed of a thermally good-conducting material, and an outer side of the transparent housing, for heat discharge, is covered with an electrically non-conducting material.

4. The LED module of claim 1, wherein the polymer mass is formed of a thermally good-conducting material that acts in an electrically insulating manner.

5. The LED module of claim 1, wherein the transparent housing can be contacted using at least one of:

a plug, socket, and a connection cable led out of the housing.

6. The LED module of claim 1, wherein, around each luminescent diode, formed as a LED die, there is a parabolic or funnel-shaped reflector of a reflector plate, formed of a thermally good-conducting and highly reflecting material, which is electrically insulated on an underside, placed from above on the circuit board.

7. The LED module according to claim 6, wherein each reflector is formed of a plastic having a mirrored inner side.

8. The LED module of claim 1, wherein a rear side of the circuit board is coupled to a cooling body, which serves for transferring discharged heat arising upon operation of the LED module to the housing or to a mounting.

9. The module of claim 1, wherein the luminescent diodes emit in a spectral range of a blue color and wherein a color conversion medium for generating a white color tone is added to the polymer mass in a region of a main emission direction above a position of monochromatic photon emission of the luminescent diodes.