Patents by Inventor Robert S. Choi

Robert S. Choi 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: 5641220
    Abstract: A portable headlamp that is particularly designed for use with bicycles integrates a number of essential features and functions desired by modem bicyclists. The headlamp has an easily removable and universally mountable fastening system that requires no tools to install. The mounting system includes a rotary joint that enables a headlamp to be pointed in any desired direction while maintaining a constant friction that can be set by the user. A focussable light beam enables the operator to vary the light distribution pattern, thereby making the headlamp suitable for use under a number of different conditions. The electrical system for the headlamp can be readily upgraded to accommodate the needs of different riding conditions, without requiring additional parts.
    Type: Grant
    Filed: January 25, 1995
    Date of Patent: June 24, 1997
    Assignee: Bell Sports, Inc.
    Inventors: Scott A. Sutherland, Thomas K. Geraty, Robert S. Choi, C. Kwai Kong, C. Philip Hope
  • Patent number: 5436810
    Abstract: A portable headlamp that is particularly designed for use with bicycles integrates a number of essential features and functions desired by modern bicyclists. The headlamp has an easily removable and universally mountable fastening system that requires no tools to install. The mounting system includes a rotary joint that enables a headlamp to be pointed in any desired direction while maintaining a constant friction that can be set by the user. A focussable light beam enables the operator to vary the light distribution pattern, thereby making the headlamp suitable for use under a number of different conditions. The electrical system for the headlamp can be readily upgraded to accommodate the needs of different riding conditions, without requiring additional parts.
    Type: Grant
    Filed: August 13, 1992
    Date of Patent: July 25, 1995
    Assignee: Vistalite, Inc.
    Inventors: Scott A. Sutherland, Thomas K. Geraty, Robert S. Choi, C. Kwai Kong, C. Philip Hope
  • Patent number: 5313187
    Abstract: One or more superluminescent light emitting diodes (SLDS) are driven with an oscillatory square wave pulse drive signal Vd varying between OVDC and 1.8-3.2VDC at a frequency between 1Hz to 12Hz, preferably between 6Hz to 8Hz, and having a pulse duty cycle between 5% to 10%, preferably between 6% to 8%, to periodically forward bias the SLDs into illumination and produce a brilliant rapidly flashing light having high on-off contrast for enhanced visibility and perceptibility at a distance, thus being usable for battery-powered visual indicator and warning flasher applications. A low frequency oscillator stage generates an oscillatory square wave voltage signal Vo which drives a power driver stage to produce the correspondingly oscillating drive voltage signal Vd which is supplied to the SLDS.
    Type: Grant
    Filed: September 6, 1990
    Date of Patent: May 17, 1994
    Assignee: Bell Sports, Inc.
    Inventors: Robert S. Choi, C. Kwai Kong, Oong Choi
  • Patent number: 5313188
    Abstract: A flashing safety warning light in which a superluminescent light-emitting diode (SLD) light source is driven by an oscillatory drive signal at a visually imperceptible but highly efficient operating frequency, the oscillatory drive signal preferably being a pulse signal of 1 to 5 KHz to cause the SLD to be illuminated and extinguished at the oscillatory drive signal frequency, such that extinction of the SLD is not visually perceptible. The oscillatory drive signal is in turn gated on and off in accordance with a gating signal at a low, highly visually perceptible frequency in the range of 3 to 12 Hz with a pulse duty cycle of between 10 to 60% in order to cause the SLD to be visually perceived as flashing on and off at the gating signal frequency in an attention-getting manner. An implementation of the flashing safety warning light for use as a bicycle safety flasher is described, and offers enhanced warning visibility with extended battery life.
    Type: Grant
    Filed: December 28, 1992
    Date of Patent: May 17, 1994
    Assignee: Bell Sports, Inc.
    Inventors: Robert S. Choi, C. Kwai Kong, Oong Choi
  • Patent number: 5175528
    Abstract: A flashing safety warning light in which a superluminescent light-emitting diode (SLD) light source is driven by an oscillatory drive signal at a visually imperceptible but highly efficient operating frequency, the oscillatory drive signal preferably being a pulse signal of 1 to 5 KHz to cause the SLD to be illuminated and extinguished at the oscillatory drive signal frequency, such that extinction of the SLD is not visually perceptible. The oscillatory drive signal is in turn gated on and off in accordance with a gating signal at a low, highly visually perceptible frequency in the range of 3 to 12 Hz with a pulse duty cycle of between 10 to 60% in order to cause the SLD to be visually perceived as flashing on and off at the gating signal frequency in an attention-getting manner. An implementation of the flashing safety warning light for use as a bicycle safety flasher is described, and offers enhanced warning visibility with extended battery life.
    Type: Grant
    Filed: August 5, 1991
    Date of Patent: December 29, 1992
    Assignee: Grace Technology, Inc.
    Inventors: Robert S. Choi, Kong C. Kwai, Choi Oong
  • Patent number: 5029198
    Abstract: A telephone call responding system which allows the user to respond to an incoming telephone call without actually speaking to the caller personally, and, if desired, without having to pick up the telephone to answer a call. To activate the responder system, the user, upon receiving an incoming telephone call, selects one of a plurality of call response messages by actuating a control key of the responder system corresponding to the desired message. Once activated, the responder system connects itself to the telephone line and, utilizing speech synthesis or digital-to-analog conversion, delivers the selected message for putting-off an unwanted or nuisance call, asking the caller to call back later, or instructing a person on an extension telephone to hang up. After delivering the message, the responder system disconnects itself from the telephone line until once again activated by the user.
    Type: Grant
    Filed: January 17, 1990
    Date of Patent: July 2, 1991
    Assignee: Geary A. Walpole
    Inventors: Geary A. Walpole, Robert S. Choi, C. Kwai Kong, Jude Buckwalter
  • Patent number: 4829492
    Abstract: A depthfinder has a color LCD display without a polarizer. This permits viewing of the display in bright sunlight, such as would be ordinarily used for fishing, without washing out of the display. Additionally, the provision of a LCD display without a polarizing filter permits viewing of the display even by a fisherman wearing polarized sunglasses without rainbow effects or fringing effects. A micrprocessor is employed to drive a color LCD display, the display having two primary colors red and green, which can be combined to form a yellow color. Additionally, a fourth color exists when the overlying pixel elements are in an off state, the color being black. A program memory provides multicolor display functions including zoom, numeric indications and numeric adjustments, and a vertical line of a predetermined color to separate the halves of a split screen zoom display.
    Type: Grant
    Filed: July 30, 1986
    Date of Patent: May 9, 1989
    Assignee: Woodstream Corporation
    Inventors: Oong Choi, Robert S. Choi, Jude Buckwalter
  • Patent number: D333041
    Type: Grant
    Filed: September 18, 1990
    Date of Patent: February 9, 1993
    Assignee: Vistalite, Incorporated
    Inventors: Robert S. Choi, C. Kwai Kong, Oong Choi
  • Patent number: D335195
    Type: Grant
    Filed: September 18, 1990
    Date of Patent: April 27, 1993
    Assignee: Vistalite, Incorporated
    Inventors: Robert S. Choi, C. Kwai Kong, Oong Choi
  • Patent number: D340777
    Type: Grant
    Filed: July 19, 1991
    Date of Patent: October 26, 1993
    Assignee: Vista Lite, Inc.
    Inventors: Robert S. Choi, Kwai C. Kong, Oong Choi, Thomas K. Geraty, Philip G. Hope