Patents by Inventor Lieu-Kim Dang

Lieu-Kim Dang 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).

  • Patent number: 6788637
    Abstract: An apparatus for reading from and/or writing to optical recording media on which data markings are arranged along tracks arranged next to one another. The apparatus according to the present invention comprises a light source, a focusing means and an intensity distribution converter. In the present invention, both the extent of the focus spot of the primary beam is reduced and the disadvantages occurring due to the secondary beams are reduced. In an exemplary embodiment, the intensity distribution converter comprises a filtering strip arranged in the region of the focusing means.
    Type: Grant
    Filed: August 2, 2000
    Date of Patent: September 7, 2004
    Assignee: Deutsche Thomson-Brandt GmbH
    Inventors: Lieu Kim Dang, Fang Lei
  • Patent number: 6781948
    Abstract: The present invention relates to a device for reading from and/or writing to optical recording media having a scanning unit, which is equipped with at least two detector units each having a plurality of detector elements, and also an evaluation unit, each of the detector elements being connected to the evaluation unit by means of a line. The object of the present invention is to simplify the structure of a device of this type. This object is achieved by virtue of the fact that detector elements of different detector units are each connected to the evaluation unit via a single line. The device according to the invention is advantageously a device which can read from and/or write to not only optical recording media which correspond to a CD standard but also those which correspond to a DVD standard.
    Type: Grant
    Filed: October 2, 2001
    Date of Patent: August 24, 2004
    Assignee: Deutsche Thomson-Brandt GmbH
    Inventors: Christian Büchler, Lieu-Kim Dang, Friedhelm Zucker
  • Patent number: 6694630
    Abstract: A multiple axis laser emitter (1) comprising an optical beam splitter (4) having at least two reflectively coated mirror surfaces (7a, 7b, 7c, 7d) oriented perpendicular to each other and each oriented at an angle of 45° to a collimated main beam (H) of a laser light source (6) and at an angle of 90° to each other, wherein, in the beam path, an optical wedge (8a, 8b, 8c, 8d, 8e) is arranged downstream to at least one of the component beams (Ta, Tb, Tc, Td) deflected by the mirror surfaces (7) at an angle of 90° to the main beam (H).
    Type: Grant
    Filed: April 3, 2002
    Date of Patent: February 24, 2004
    Assignee: Hilti Aktiengesellschaft
    Inventors: Lieu-Kim Dang, Erwin Bünter, Karsten Brandenburg
  • Patent number: 6678222
    Abstract: The present invention relates to an apparatus for reading from and/or writing to optical recording media with optical scanner, light source, focusing means, tilting-detection device and tilting-compensation device. The object of the invention is to propose an apparatus and a method, which enables optimum compensation of tilting using as few apparatus functions as possible. This is achieved according to the invention by using a tilting-detection device comprising an optical grating, a detector element, a control device for controlling light source and the focusing means and a control device controlling for the tilting-compensation device.
    Type: Grant
    Filed: April 26, 2000
    Date of Patent: January 13, 2004
    Assignee: Thomson Licensing, S.A.
    Inventors: Heinz-Jörg Schröder, Lieu Kim Dang
  • Publication number: 20030189887
    Abstract: A device for reading from and/or writing to optical recording media 10, on which information is present in the form of pits, with a linearly polarized light beam 2.
    Type: Application
    Filed: March 31, 2003
    Publication date: October 9, 2003
    Inventors: Lieu-Kim Dang, Heinz-Jorg Schroder
  • Patent number: 6574183
    Abstract: The present invention relates to a device for reading from or writing to optical recording media, which device has a scanning beam generation means, a focusing means and a photodetector comprising at least two detector zones and serving to receive zeroth- and first-order diffraction beams from the recording medium. The object of the invention is to obtain a reduction in interfering influences in a signal derived from signals of the photodetector, a signal such as, for example, a focus error signal or a track error signal. This object is achieved by virtue of the fact that a beam splitting means is provided, which splits a light spot falling onto the photodetector into two separate partial spots. The device is, for example, a CD or DVD player, but in particular a recording and reproduction device for so-called DVD-RAMs or similar optical recording media.
    Type: Grant
    Filed: March 28, 2002
    Date of Patent: June 3, 2003
    Assignee: Thomson Licensing, S.A.
    Inventors: Lieu Kim Dang, Christoph Dietrich, Hartmut Richter, Heinz-Jörg Schroeder
  • Patent number: 6529329
    Abstract: An optical alignment apparatus including a beam splitter (2) for diverging a primary laser beam (4) emitted by a radiation source (5) into a plurality of divergent beam portions (3a, 3b, 3c, 3d, 3e), and elements for minimizing the angle error of the divergent beam portions (3a, 3b, 3c, 3d, 3e) and including a collimator (6) located between the radiation source (5) and the beam splitter (2), and a spacially oscillatingly adjustable, transparent, plane-parallel plate (7) arranged in a path of the primary laser beam (4).
    Type: Grant
    Filed: August 28, 2001
    Date of Patent: March 4, 2003
    Assignee: Hilti Aktiengesellschaft
    Inventor: Lieu-Kim Dang
  • Publication number: 20020144415
    Abstract: A multiple axis laser emitter (1) comprising an optical beam splitter (4) having at least two reflectively coated mirror surfaces (7a, 7b, 7c, 7d) oriented perpendicular to each other and each oriented at an angle of 45° to a collimated main beam (H) of a laser light source (6) and at an angle of 90° to each other, wherein, in the beam path, an optical wedge (8a, 8b, 8c, 8d, 8e) is arranged downstream to at least one of the component beams (Ta, Tb, Tc, Td) deflected by the mirror surfaces (7) at an angle of 90° to the main beam (H).
    Type: Application
    Filed: April 3, 2002
    Publication date: October 10, 2002
    Inventors: Lieu-Kim Dang, Erwin Bunter, Karsten Brandenburg
  • Patent number: 6430141
    Abstract: A device for reading from or writing to optical recording media comprising a scanning beam generation means, a focusing means and a photodetector comprising at least two detector zones and serving to receive zeroth- and first-order diffraction beams from the recording medium. The object of the invention is to obtain a reduction in interfering influences in a signal derived from signals of the photodetector, a signal such as, for example, a focus error signal or a track error signal. This object is achieved by virtue of the fact that a beam splitting means is provided, which splits a light spot falling onto the photodetector into two separate partial spots. The device is, for example, a CD or DVD player, but in particular a recording and reproduction device for so-called DVD-RAMs or similar optical recording media.
    Type: Grant
    Filed: April 8, 1999
    Date of Patent: August 6, 2002
    Assignee: Thomson Licensing, S.A.
    Inventors: Lieu Kim Dang, Christoph Dietrich, Hartmut Richter, Heinz-Jörg Schroeder
  • Publication number: 20020101813
    Abstract: The present invention relates to a device for reading from or writing to optical recording media, which device has a scanning beam generation means, a focusing means and a photodetector comprising at least two detector zones and serving to receive zeroth- and first-order diffraction beams from the recording medium.
    Type: Application
    Filed: March 28, 2002
    Publication date: August 1, 2002
    Inventors: Lieu Kim Dang, Christoph Dietrich, Hartmut Richter, Heinz-Jorg Schroeder
  • Publication number: 20020085611
    Abstract: An optical alignment apparatus including a beam splitter (2) for diverging a primary laser beam (4) emitted by a radiation source (5) into a plurality of divergent beam portions (3a, 3b, 3c, 3d, 3e), and elements for minimizing the angle error of the divergent beam portions (3a, 3b, 3c, 3d, 3e) and including a collimator (6) located between the radiation source (5) and the beam splitter (2), and a spacially oscillatingly adjustable, transparent, plane-parallel plate (7) arranged in a path of the primary laser beam (4).
    Type: Application
    Filed: August 28, 2001
    Publication date: July 4, 2002
    Inventor: Lieu-Kim Dang
  • Patent number: 6400670
    Abstract: The present invention relates to a device for the reading and/or writing of optical recording media [(AT)] of various structures, which device operates with a single objective lens [(OL)]. The invention proposes to use a diaphragm varying in diameter, in particular a polarizing filter arranged in the optical path in order to adapt the aperture to each type of optical recording medium [(AT)] used. The wavefront can be corrected using a divergent lens [(SL)] which can also be positioned in the beam path. The Diaphragm formed by the polarizing filter PF is linked to the objective lens [(OL)]. The field of application of the invention relates to, in particular, devices for reading and/or writing optical recording media [(AT)] of various structure such as compact discs and digital video discs.
    Type: Grant
    Filed: August 14, 1998
    Date of Patent: June 4, 2002
    Assignee: Deutsche Thomson-Brandt GmbH
    Inventor: Lieu-Kim Dang
  • Publication number: 20020009041
    Abstract: The present invention relates to a device for reading from and/or writing to optical recording media having a scanning unit, which is equipped with at least two detector units each having a plurality of detector elements, and also an evaluation unit, each of the detector elements being connected to the evaluation unit by means of a line.
    Type: Application
    Filed: October 2, 2001
    Publication date: January 24, 2002
    Inventors: Christian Buchler, Lieu-Kim Dang, Friedhelm Zucker
  • Patent number: 6304542
    Abstract: A dual wavelength optical pickup head in which as many same parts as possible are used as well to direct light beams incident than light beams reflected from a reflective layer of an optical disk. The reuse of as many parts as possible allows to and a second wavelength emitted by a first and a second light source to an optical disk, a dual focus lens objective for focusing said light beams on a layer of said optical disk and a single detector which allows to detect light beams of either said first or said second wavelength.
    Type: Grant
    Filed: October 16, 1998
    Date of Patent: October 16, 2001
    Assignee: Deutsche Thomson-Brandt GmbH
    Inventors: Lieu-Kim Dang, Christoph Dietrich, Hartmut Richter, Heinz-Joerg Schroeder
  • Patent number: 6285641
    Abstract: A device for writing to and/or reading from optical recording media having different structures is described, for example, a device which is suitable both for writing to/reading from digital videodisks (DVD) and conventional CD's. Provision is made for measuring the intensity of each peak in the mirror signal while the objective lens is moving to the recording medium. The intensity e.g. at the instant of the positive-negative crossing of the focus error signal is taken in this case. The type of optical recording medium is determined from the time characteristic and/or the height distribution of the peaks. In order to identify the type of optical recording medium, different properties of the optical recording medium are taken into account, such as reflectivity of the corresponding reflective surface, reduced intensity modulation due to spherical aberration, time characteristic and the like.
    Type: Grant
    Filed: September 3, 1998
    Date of Patent: September 4, 2001
    Assignee: Deutsche Thomson-Brandt GmbH
    Inventors: Lieu Kim Dang, Friedhelm Zucker, Heinz-Jörg Schroeder
  • Patent number: 6249493
    Abstract: The present invention relates to a recording or replay device, and to a method for recognizing a focussing status. The object of the invention is to provide a method of this type and a recording or replay device, with the facility of producing significant astigmatism in the reflected light beam (15) simply and cost-efficiently without elaborate alignment. This object is achieved by the use of a birefringent element (23, 24). The invention is, in particular, suitable for use in a recording or replay device for writing to or playing back optical recording media (11) such as CDs, video discs, DVDs and the like.
    Type: Grant
    Filed: October 8, 1997
    Date of Patent: June 19, 2001
    Assignee: Deutsche Thomson-Brandt GmbH
    Inventor: Lieu Kim Dang
  • Patent number: 6219316
    Abstract: A recording or reproduction device with a three-point scanning arrangement compatible for use with recording media having different track spacings. The invention makes it possible, without changing the setting of the three-point scanning system, to use recording media having different track spacings. According to the invention, the three-point scanning system is set in such a way that the scanning center points have a lateral spacing from one another which is within a range of a first product, formed by a first predetermined value and the first track spacing, and a second product, formed by a second predetermined value and the second track spacing, the range being less than 8 percent of the value of the first product.
    Type: Grant
    Filed: March 26, 1997
    Date of Patent: April 17, 2001
    Assignee: Deutsche Thomson-Brandt GmbH
    Inventors: Christian Buechler, Lieu-Kim Dang, Heinz-Joerg Schroeder
  • Patent number: 6084835
    Abstract: Tracking error signal in an optical read/write device, such as a CD ROM, are fine tuned for deviations in the positions of the lens structure normal to the recorded medium to provide more precise tracking control. Track error signal is developed by means of DPD-TE circuitry, using for example, signals from a four quadrant photodetector. Selected pairs of the signals from the photodetector are summed and the sums are differenced to develop an intermediate signal. The intermediate signal is amplified with a gain proportional the reciprocal of the intensity of light received by the photodetector, and thereafter combined with the track error signal to provide a corrected track error signal.
    Type: Grant
    Filed: July 30, 1997
    Date of Patent: July 4, 2000
    Assignee: Deutsche Thomson-Brandt GmbH
    Inventors: Christian Buchler, Lieu Kim Dang
  • Patent number: 5953304
    Abstract: A device for corrected-focus scanning of information while recording on and/or replaying information from a recording medium is based on a radiation source which provides a scanning beam, a focusing objective lens and a radiation-sensitive detector system. A diffraction element for deriving a focus error signal is arranged in the space between the focusing objective lens and the detector system, at a predetermined, fixed distance, the diffraction element being designed such that two focus planes result which are physically separated from one another. The detector system is located between the separate focus planes such that the size ratios, which change in the event of defocusing, of the symmetrically imaged focus spot can be used to derive the focus error signal.
    Type: Grant
    Filed: August 28, 1997
    Date of Patent: September 14, 1999
    Assignee: Deutsche Thomson-Brandt GmbH
    Inventors: Lieu Kim Dang, Christian Buechler
  • Patent number: 5777976
    Abstract: An optical scanning device having a holographic optical element for receiving a scanning beam which has been influenced by a recording medium. One aspect of the invention is to use an optical spatial filter to obtain the information signals. A further aspect is to image the entire area of the scanning spot on only one detector and to use the complete light component, as a result of which the power component is increased and the requirements for adjustment of a plurality of elements with respect to one another are reduced.
    Type: Grant
    Filed: June 13, 1996
    Date of Patent: July 7, 1998
    Assignee: Deutsche Thomson-Brandt GmbH
    Inventor: Lieu Kim Dang