Patents by Inventor Yajun Li

Yajun Li 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: 5468952
    Abstract: A miniature high speed bar code scanning element is housed within an industry standard PCMCIA card for implementation in personal computing devices. In one embodiment, the scan element is mounted on the exterior of the card for pivotal movement about vertical and horizontal axes.
    Type: Grant
    Filed: June 20, 1994
    Date of Patent: November 21, 1995
    Assignee: Symbol Technologies, Inc.
    Inventors: Edward R. Alexander, Ron Goldman, Yajun Li, Simon Bard, Askold Strat, Joseph Katz, Boris Metlitsky
  • Patent number: 5404001
    Abstract: The laser diode of an optical scanning system is located in a separate unit and light therefrom carried to a remote scan head via an optical fiber. This reduces the size and weight as well as temperature sensitivity of the scan head. The separate unit may include an optical sensor for detecting light reflected from scanned symbols. If the separate unit houses the sensor, the same fiber or an additional fiber will collect the reflected light and transmit that light back to the sensor. An electromagnetic system produces a scanning motion of the beam emitted by the scan head where the optical fiber is attached to a magnet.
    Type: Grant
    Filed: October 8, 1992
    Date of Patent: April 4, 1995
    Inventors: Simon Bard, Joseph Katz, Miklos Stern, Yajun Li
  • Patent number: 5374817
    Abstract: To reduce the size and weight of an optical scanner, the present invention provides a mirrorless beam scanning unit. A flexible support structure, such as one or more strips of mylar, movably mounts the objective lens in front of the light emitter. The objective lens is laterally reciprocated in response to a motive force, for example as might be applied by a combination of a permanent magnet coupled to the objective lens and a fixedly mounted electromagnet driven by an alternating current signal. Reciprocation of the objective lens during emission of light by the light emitter causes the light to scan a surface, such as a surface bearing a bar code label.
    Type: Grant
    Filed: June 12, 1992
    Date of Patent: December 20, 1994
    Assignee: Symbol Technologies, Inc.
    Inventors: Simon Bard, Yajun Li, Jerome Swartz, Boris Metilitsky, Joseph Katz, Askold Stratienco, Hal Charych
  • Patent number: 5352922
    Abstract: The method and apparatus of this invention facilitate operation of a bar code reader over a wider range of working angle and for a wider range of bar code densities. The invention includes improved optics and sensing elements. The optics and sensing elements and/or the associated circuitry are arranged to provide two channels of data derived form the scanned bar code. The two channels have differing resolutions. Analysis of the data from the two channels provides a single decoded result. As the working angle and density vary at least one of the resolutions will be appropriate for sensing all or most of the bar coded data. The data from the channel producing a valid result can be used, or if neither channel produces a valid result by itself, data from each channel can be analyzed and valid portions of the data from both channels combined to produce the single decoded result.
    Type: Grant
    Filed: August 19, 1993
    Date of Patent: October 4, 1994
    Assignee: Symbol Technologies, Inc.
    Inventors: Edward Barkan, David P. Goren, Joseph Katz, Yajun Li, Jerome Swartz, Thomas Mazz
  • Patent number: 5332892
    Abstract: The invention facilitates operation of a bar code reader over a wider range of working angle, a wider range of distances from the bar code and a wider range of bar code densities. The invention includes improved optics and sensing elements. To provide a wider depth of field the optics associated with the emitter and or the photodetector have two distinct focal points. In the preferred embodiments, the optics and sensing elements and/or the associated circuitry are arranged to provide two channels of data derived form the scanned bar code. The two channels have differing resolutions. Analysis of the data from the two channels provides a single decoded result. As the working angle and density vary at least one of the resolutions will be appropriate for sensing all or most of the bar coded data.
    Type: Grant
    Filed: December 24, 1991
    Date of Patent: July 26, 1994
    Assignee: Symbol Technologies, Inc.
    Inventors: Yajun Li, Edward Barkan, David P. Goren, Joseph Katz
  • Patent number: 5302812
    Abstract: A laser scanning head in which the range of the beam waist is varied independently of any measurement of the actual range of the symbol. The optical member is a condenser lens that is moved by energizing a magnetic coil; the lens is operated independently of the scanning movement of the laser beam, to produce a continuous, progressive variation (e.g., a continuous oscillation) in the range of the beam waist, so that at some point in the variation the spot size on the symbol will be of an appropriate size. The movement of the lens can be synchronized with the beam scan (e.g., so that the same spot size can be maintained for several scans). Spot size can be chosen adaptively, by varying the range of the beam waist until the contrast in the reflected light collected from the symbol exceeds a predetermined level.
    Type: Grant
    Filed: December 23, 1991
    Date of Patent: April 12, 1994
    Assignee: Symbol Technologies, Inc.
    Inventors: Yajun Li, Joseph Katz, Paul Dvorkis
  • Patent number: 5278397
    Abstract: The method and apparatus of this invention facilitate operation of a bar code reader over a wider range of working angle and for a wider range of bar code densities. The invention includes improved optics and sensing elements. The optics and sensing elements and/or the associated circuitry are arranged to provide two channels of data derived form the scanned bar code. The two channels have differing resolutions. Analysis of the data from the two channels provides a single decoded result. As the working angle and density vary at least one of the resolutions will be appropriate for sensing all or most of the bar coded data. The data from the channel producing a valid result can be used, or if neither channel produces a valid result by itself, data from each channel can be analyzed and valid portions of the data from both channels combined to produce the single decoded result.
    Type: Grant
    Filed: July 25, 1991
    Date of Patent: January 11, 1994
    Assignee: Symbol Technologies, Inc.
    Inventors: Edward Barkan, David P. Goren, Joseph Katz, Yajun Li, Jerome Swartz, Thomas Mazz