Patents by Inventor Holger Zellmer

Holger Zellmer 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).

  • Publication number: 20210245542
    Abstract: A method for producing security elements in an image which are not visible to the human eye and which cannot be copied, in particular for checking the authenticity of images. The image is imaged by means of a halftone, the halftone consisting of individual image dots arranged adjacent to each other. This is characterized in that at least one field having a random geometric shape or freeform is defined in the image/the halftone. By means of manipulation of image dots in the field and/or by means of manipulation of the entire field, an encrypted information that cannot be copied is stored for comparison with at least one database and the serial number is displayed by means of contours formed in the halftone.
    Type: Application
    Filed: June 22, 2019
    Publication date: August 12, 2021
    Inventors: Jörg Kaufmann, Frank Theeg, Holger Zellmer
  • Publication number: 20210248369
    Abstract: A method for checking the authenticity of products, by checking an image (A) of a product. The proof of authenticity is not visible to the human eye and cannot be copied. This is characterized in that a code stored in a halftone image by manipulation of dots and/or a manipulated field bounded in the halftone image can be read by means of an optical device and compared with a retrievable value in at least one database. In at least one field (F1 to F5) a part of a serial number is determined which describes the structure of the serial number and a hash function used for transmitting the serial number to the database, and this is also characterized in that the serial number is subsequently assembled and encrypted with the corresponding hash function.
    Type: Application
    Filed: June 22, 2019
    Publication date: August 12, 2021
    Inventors: Jörg Kaufmann, Frank Theeg, Holger Zellmer
  • Patent number: 6697394
    Abstract: A directly modulatable laser comprising an active medium inside a laser cavity formed by a resonator mirror and an out-coupling mirror, and a pump light source exciting the active medium. It is characterized in that the active medium generates radiation of two wavelengths (&lgr;1 and &lgr;2) and the resonator mirror is constructed as a controllable reflector by which the reflectivity is controllable for each of the two wavelengths (&lgr;1 and &lgr;2) and the controllable reflector is connected with a control unit, wherein the reflection factor is controlled in such a way that the inversion density of the electrons which is generated in the active medium is constant and the light output of one of the wavelengths ((&lgr;1) is controllable between a minimum value and a maximum value according to an applied control signal, wherein the control of the two wavelengths ((&lgr;1 and &lgr;2) is carried out in push-pull.
    Type: Grant
    Filed: February 9, 2001
    Date of Patent: February 24, 2004
    Assignee: Jenoptik LDT GmbH
    Inventors: Andreas Tuennermann, Holger Zellmer, Jens-Peter Ruske
  • Publication number: 20020018287
    Abstract: A fiber-optic amplifier comprising a laser source which emits signal radiation in a narrow band on one or more wavelengths in a first end of an amplifier fiber, and amplified signal radiation can be coupled out at a second end of the amplifier fiber. The amplifier fiber is a double-core fiber with a pump core and a laser core and the latter is end pumped or side pumped. The amplifier fiber is a multimode double-core fiber at which or within which is arranged, in the area of its first end, an element for transverse mode selection which suppresses modes higher than the fundamental mode.
    Type: Application
    Filed: February 27, 2001
    Publication date: February 14, 2002
    Applicant: SCHEIDER Laser Technologies AG
    Inventors: Holger Zellmer, Andreas Tuennermann
  • Publication number: 20010017868
    Abstract: An arrangement which generates red, green and blue laser radiation comprise a laser radiation source whose first beam (&lgr;l) is split in the infrared wavelength range, wherein the first part of this beam is frequency-doubled and green light (&lgr;G) results and another part is used to generate light of the primary colors red (&lgr;R) and blue (&lgr;B). Another part of the first beam (&lgr;l) is fed to a wavelength converter which generates another beam (&lgr;2, &lgr;4) in the infrared wavelength range which has a greater wavelength than the first beam (&lgr;l), further, the colors red (&lgr;R) and blue (&lgr;B) result from the further beam (&lgr;2, &lgr;4) or from a part thereof by another nonlinear process by sum frequency mixing or by frequency doubling or by sum frequency mixing and frequency doubling.
    Type: Application
    Filed: February 23, 2001
    Publication date: August 30, 2001
    Applicant: SCHNEIDER Laser technologies AG;
    Inventors: Juergen Kraenert, Thomas Gabler, Holger Zellmer, Andreas Tuennermann
  • Publication number: 20010017867
    Abstract: A fiber amplifier is disclosed comprising a signal source (oscillator), an amplifier fiber and a pump laser. The amplifier fiber is arranged between two polarizers and a portion of the beam that is depolarized in the amplifier fiber is coupled out at the amplifier output, returned to the amplifier input, coupled into the amplifier fiber with the radiation from the signal source and amplified again, and another portion, as linearly polarized beam, exits the fiber amplifier as useful beam.
    Type: Application
    Filed: February 27, 2001
    Publication date: August 30, 2001
    Applicant: SCHNEIDER Laser Technologies AG
    Inventors: Juergen Kraenert, Thomas Gabler, Holger Zellmer, Andreas Tuennermann
  • Publication number: 20010014107
    Abstract: A directly modulatable laser comprising an active medium inside a laser cavity formed by a resonator mirror and an out-coupling mirror, and a pump light source exciting the active medium. It is characterized in that the active medium generates radiation of two wavelengths (&lgr;1 and &lgr;2) and the resonator mirror is constructed as a controllable reflector by which the reflectivity is controllable for each of the two wavelengths (&lgr;1 and &lgr;2) and the controllable reflector is connected with a control unit, wherein the reflection factor is controlled in such a way that the inversion density of the electrons which is generated in the active medium is constant and the light output of one of the wavelengths ((&lgr;1) is controllable between a minimum value and a maximum value according to an applied control signal, wherein the control of the two wavelengths ((&lgr;1 and &lgr;2) is carried out in push-pull.
    Type: Application
    Filed: February 9, 2001
    Publication date: August 16, 2001
    Applicant: SCHNEIDER Laser Technologie AG;
    Inventors: Andreas Tuennermann, Holger Zellmer, Jens-Peter Ruske
  • Patent number: 5864645
    Abstract: A double-core light-conducting fiber comprise a pump core, a laser core which is arranged centrically in the pump core, and a cladding surrounding the pump core. The pump core which is constructed with a substantially circular cross section has at least one ground portion on the outside which extends in the light direction of the double-core light-conducting fiber and amounts to 1% to 49% of the diameter of the pump core. A process for the production of the double-core light-conducting fiber and to a double-core fiber laser and to a double-core fiber amplifier are also disclosed which use the double-core light-conducting fiber according to the invention. The substantially round pump core with its centrically arranged laser core enables a simple connection with other fiber-optic components and a simple coupling in of the pumping light.
    Type: Grant
    Filed: May 16, 1997
    Date of Patent: January 26, 1999
    Assignee: LDT GmbH & Co. Laser-Display-Technologie KG
    Inventors: Holger Zellmer, Joern Bonse, Sonja Unger, Volker Reichel