Patents by Inventor Rene P. Helbing

Rene P. Helbing 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: 6313820
    Abstract: A method of operating a ferroelectric liquid crystal-based spatial light modulator in a non-DC-Balanced mode to delay the onset of pixel sticking. The method includes providing a spatial light modulator including a transparent electrode, a pixellated electrode, and a ferroelectric liquid crystal layer sandwiched between the transparent electrode and the pixellated electrode. The spatial light modulator is illuminated with a light source for an illumination time. A portion of the pixellated electrode is set to a high drive signal voltage level during a first portion of illumination time, and set to a low drive signal voltage level during a second portion of the illumination time. The transparent electrode is maintained at a first voltage potential between the high drive signal voltage level and the low drive signal voltage level during the first and second portions of illumination time. The spatial light modulator is then darkened for a darkened time.
    Type: Grant
    Filed: January 29, 1999
    Date of Patent: November 6, 2001
    Assignee: Hewlett-Packard Co.
    Inventors: Rene P. Helbing, Mark M. Butterworth
  • Patent number: 6262829
    Abstract: A method of digital grayscale control using light source modulation. First, a light valve, grayscale data, and a light source are provided. The light valve includes a spatial light modulator with at least one pixel. The grayscale data indicates desired grayscale level for the pixel during a frame period. The light source is configured to illuminate the pixel, to generate light with increasing intensity for a rise-time after electric power to the light source is substantially increased, and to generate light with decreasing intensity for a decay-time after electric power to the light source is substantially reduced. The light source may be an arc-lamp. The rise-time and the decay-time taken together may constitute a majority of the frame period. During the frame period, the electric power to the light source is substantially increased and is substantially decreased. Substantially decreasing the electric power to the light source may include turning off the electric power.
    Type: Grant
    Filed: July 29, 1999
    Date of Patent: July 17, 2001
    Assignee: Hewlett-Packard Co.
    Inventors: Akinobu Kuramoto, Rene P. Helbing
  • Patent number: 6198523
    Abstract: A ferroelectric liquid crystal-based switchable half-wave plate with improved alignment control, a ferroelectric liquid crystal-based light valve system with improved contrast control, and a method of improving contrast in a ferroelectric liquid crystal-based light valve system. The switchable half-wave plate with improved alignment control includes a layer of ferroelectric liquid crystal material sandwiched between a first transparent electrode and a second transparent electrode. The switchable half-wave plate also includes an electric field direction switching circuit configured to switch the electric field across the liquid crystal material between the forward direction and the reverse direction in response to a control signal. The switchable half-wave plate additionally includes an electric field magnitude control circuit to adjust the tilt angle in response to a signal received at a alignment control signal input.
    Type: Grant
    Filed: October 28, 1999
    Date of Patent: March 6, 2001
    Assignee: Hewlett-Packard Co.
    Inventor: Rene P. Helbing
  • Patent number: 6157432
    Abstract: A heated ferroelectric liquid crystal-based spatial light modulator (SLM) that minimizes pixel sticking when operated in a non-DC-balanced mode with spiking and method for using same. The SLM comprises a transparent electrode, a pixellated electrode, ferroelectric liquid crystal material, and a heater. The ferroelectric liquid crystal material is sandwiched between the transparent electrode and the pixellated electrode. The heater is capable of heating the ferroelectric material to at least 40.degree. C. and preferably to between 50 and 60.degree. C. The invention may also provide a temperature sensor for detecting the temperature of the SLM and a temperature control circuit that is electrically connected to both the temperature sensor and the heater. The temperature sensor may be a diode located proximate to the pixellated electrode or a photo-diode located remote from the spatial light modulator.
    Type: Grant
    Filed: January 29, 1999
    Date of Patent: December 5, 2000
    Assignee: Hewlett-Packard Company
    Inventor: Rene P. Helbing
  • Patent number: 5942284
    Abstract: A method for depositing a thin film including a sulfide of a metal on a substrate. First and second vapor streams are generated and combined in the vicinity of the substrate. The first vapor stream includes an organic compound containing the metal is generated. The second vapor stream includes a mercaptan. The preferred mercaptan is tertrary-butyl-mercaptan. The preferred metal precursor is a .beta.-diketonate of the metal.
    Type: Grant
    Filed: November 27, 1996
    Date of Patent: August 24, 1999
    Assignee: Hewlett-Packard Company
    Inventors: Ronald Hiskes, Rene P. Helbing, Stephen A. DiCarolis
  • Patent number: 5847507
    Abstract: A process and apparatus is described to produce efficient light emission over a broad portion of the visible spectrum. A lens containing a fluorescent dye is over molded to a short wavelength light emitter (e.g., a blue LED or laser diode) placed within a reflector cup. The fluorescent dye absorbs at least a portion of the light emitted by the diode and re-emits light of a second, longer wavelength. Concentration of the dye within the lens can be varied to control the extent of a region within the lens where most of the light is re-emitted so the remaining portion of the lens can focus the light. One can readily and consistently tailor the color of the light emitted from the lens through selection of the number and types of fluorescent dyes added to the lens, and through their relative concentrations. Inventory is reduced and there are no additional steps required when building varied color LEDs.
    Type: Grant
    Filed: July 14, 1997
    Date of Patent: December 8, 1998
    Assignee: Hewlett-Packard Company
    Inventors: Mark M. Butterworth, Rene P. Helbing
  • Patent number: 5629126
    Abstract: A composition for use in constructing a photosensitive film for recording an image. The composition includes first, second, and third particle types, each the particle type including a crystalline base material having a trap dopant and a color dopant deposited therein. Each of the color dopants has a different spectral sensitivity. One of the particle types is sensitive to light in the red portion of the visible spectrum. This particle type includes a crystalline base material including an alkaline earth sulfide or selenide doped with Yb.sup.+2.
    Type: Grant
    Filed: June 17, 1996
    Date of Patent: May 13, 1997
    Assignee: Hewlett-Packard Company
    Inventors: William R. Trutna, Jr., Rene P. Helbing