Patents by Inventor Stefan P. Grabowski

Stefan P. Grabowski has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Light emitting diode driving apparatus
    Patent number: 8536796
    Abstract: A light emitting diode driving apparatus (1) comprises an arrangement (10) for supplying a signal to light emitting diodes (11, 12). The light emitting diodes (11, 12) comprise different internal impedances (41, 42) for producing different light outputs in response to a parameter of the signal having different values. As a result, the light emitting diodes (11, 12) can be driven relatively independently from each other. Each light output may have an intensity and/or a color. Different light outputs may have different intensities for dimming purposes and/or different colors for color tuning purposes. The parameter may comprise a frequency parameter and/or a timing parameter. The light emitting diodes (11, 12) may form parts of a serial branch, for example when being stacked organic light emitting diodes, or may form part of parallel branches. The internal impedances (41, 42) may comprise capacities (21, 22) and resistivities (31, 32).
    Type: Grant
    Filed: October 15, 2009
    Date of Patent: September 17, 2013
    Assignee: Koninklijke Philips N.V.
    Inventors: Hans-Peter Loebl, Stefan P. Grabowski
  • LIGHT EMITTING DIODE DRIVING APPARATUS
    Publication number: 20110199009
    Abstract: A light emitting diode driving apparatus (1) comprises an arrangement (10) for supplying a signal to light emitting diodes (11, 12). The light emitting diodes (11, 12) comprise different internal impedances (41, 42) for producing different light outputs in response to a parameter of the signal having different values. As a result, the light emitting diodes (11, 12) can be driven relatively independently from each other. Each light output may have an intensity and/or a color. Different light outputs may have different intensities for dimming purposes and/or different colors for color tuning purposes. The parameter may comprise a frequency parameter and/or a timing parameter. The light emitting diodes (11, 12) may form parts of a serial branch, for example when being stacked organic light emitting diodes, or may form part of parallel branches. The internal impedances (41, 42) may comprise capacities (21, 22) and resistivities (31, 32).
    Type: Application
    Filed: October 15, 2009
    Publication date: August 18, 2011
    Applicant: KONINKLIJKE PHILIPS ELECTRONICS N.V.
    Inventors: Hans-Peter Loebl, Stefan P. Grabowski