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: 6398112
    Abstract: A scanning device for reading indicia of differing light reflectivity, including bar code or matrix array symbols, has a single light emitter, such as a laser or light emitting diode, for generating a scanning light beam to visually illuminate sequential portions of the indicia. A sensor, such as a charge coupled or other solid state imaging device, simultaneously detects light reflected from portions of the indicia and generates an electrical signal representative of the spacial intensity variations the portions of the indicia. The scanning device may also include an ambient light sensor, and a second light emitter for use only in aiming or orienting the scanning device. A photodetector may also be provided to separately detect one symbol virtually simultaneous with the detection of another symbol by the sensor or to provide dual modalities. A method for reading indicia is also provided.
    Type: Grant
    Filed: March 31, 2000
    Date of Patent: June 4, 2002
    Assignee: Symbol Technologies, Inc.
    Inventors: Yajun Li, Joseph Katz, Jerome Swartz, Edward Barkan
  • Publication number: 20020036258
    Abstract: A beam generator, or beam shaping system, for example for use in an optical scanner, creates a non-Gaussian beam which provides improved indicia-reading characteristics. In one embodiment, diffractive optical elements are used to create a Bessel-Gaussian scanning beam, which comprises a coherent combination of a Gaussian beam and a Bessel beam.
    Type: Application
    Filed: May 31, 2001
    Publication date: March 28, 2002
    Inventors: Leonard Bergstein, Emanuel Marom, Yajun Li, Joseph Katz
  • Patent number: 6360949
    Abstract: A miniaturized electro-optical, retro-reflective scanning module. The module has a base, a first circuit board, and a second circuit board mounted substantially orthogonal to the first circuit board. The base supports a light emitter for producing a scanning beam and optical elements for directing and collecting light energy. The emitted beam reflects off a fold mirror onto a reflector mounted on a drive for oscillation. The oscillating reflector, in turn, redirects the beam onto an indicia being read. The reflected light is reflected off the oscillating reflector and directed to the collection mirror before reaching a detector. The detector included in the module senses light reflected from an indicia scanned by the beam. The reflector is driven by an electro-magnetiz driven system, including a flexure and an actuation arm.
    Type: Grant
    Filed: March 24, 1999
    Date of Patent: March 26, 2002
    Assignee: Symbol Technologies, Inc.
    Inventors: Howard Shepard, Edward D. Barkan, Paul Dvorkis, Boris Metlitsky, Raj Bridgelall, Vladimir Gurevich, Mark Krichever, Yajun Li, Joseph Katz, Vincent Luciano
  • Publication number: 20020011520
    Abstract: An improved optical system for scanning optical codes is disclosed. A laser beam produced thereby is a diverging, nearly diffraction free beam and may be used to produce an elongated scanning spot. An aperture may be employed such that variation in size of the aperture in one orthogonal dimension varies the size of the scanning spot in another orthogonal dimension.
    Type: Application
    Filed: August 2, 2001
    Publication date: January 31, 2002
    Inventors: Vladimir Gurevich, Mark Krichever, Yajun Li
  • Patent number: 6340114
    Abstract: An imaging engine and signal processing devices and methods are disclosed for reading various kinds of optical codes. The compact structure may include a two dimensional image sensor, apparatus for focusing images at different focal disclosures, an aiming system, a hi-low beam illumination system and related signal processing circuits.
    Type: Grant
    Filed: June 12, 1998
    Date of Patent: January 22, 2002
    Assignee: Symbol Technologies, Inc.
    Inventors: Mark Correa, Rubin Gelles, Duanfeng He, Eugene Joseph, Yajun Li, Mehul Patel, Thomas M. Stankelis
  • Patent number: 6334573
    Abstract: An integrated scanner for scanning a barcode omnidirectionally is formed an a common substrate. The scanner may include a mirror assembly or scan module, a laser diode, and a detector, mounted on a single substrate or several connected substrates. Lenses can be used to focus a laser beam from the laser diode as well as expand a laser beam deflected by the micro-machined mirror.
    Type: Grant
    Filed: August 12, 1997
    Date of Patent: January 1, 2002
    Assignee: Symbol Technologies, Inc.
    Inventors: Yajun Li, Paul Dvorkis, Simon Bard, Raj Bridgelall
  • Publication number: 20010036140
    Abstract: An improved light-readable information recording medium is provided that comprises an optical data storage structure having lands and pits, in which the depth of the pits is about: 1 λ 2 ⁢ n ⁢   ⁢   ⁢ M 1 + m t 2 ,
    Type: Application
    Filed: April 25, 2001
    Publication date: November 1, 2001
    Applicant: WEA Manufacturing
    Inventors: Yajun Li, Emil Wolf
  • Patent number: 6283372
    Abstract: A hand-held optical reader for reading printed indicia on a remote target includes a light source for generating a scanning light beam and a detector for detecting the light reflected from the printed indicia. The light source and detector are housed within a housing having a window through which the light beam passes from the source to the target for reflection from the target to the detector. The housing includes parallel front and rear faces, each being generally rectangular in shape and having a lower portion and upper portion. The front and rear faces are joined by a substantially planar base face at their lower edges. The window is disposed in the front face with the reader being ergonomically configured so as be comfortably held in the hand of a user, with the user's palm adjacent the rear face to enable the user to direct the scanning light beam at a remote target.
    Type: Grant
    Filed: August 23, 1999
    Date of Patent: September 4, 2001
    Assignee: Symbol Technologies, Inc.
    Inventor: Yajun Li
  • Patent number: 6209788
    Abstract: An optical scanning system is provided for producing a signal representative of a spatial distribution of indicia having different degrees of reflectivity to light, such as a bar code (14). The system includes an optical scanner (12) for scanning beam of light over the spatial distribution of indicia (14) and for producing an electrical signal corresponding to changes in the degree of reflectivity of the indicia. A digitizer (20), responsive to detections in a predetermined characteristic of the produced electrical signal is provided. The digitizer (20) converts the detections into digital words, such digital signals having a plurality of bits. The digitizer includes a timing generation circuit (42) for producing a pulse in response to each one of the detections with a time duration representative of the degree of reflectivity of the indicia as the beam of light. A decoder converts the time duration of the pulse into the digital word having a plurality of bits. An enhancement filter (30) is also disclosed.
    Type: Grant
    Filed: November 8, 1999
    Date of Patent: April 3, 2001
    Assignee: Symbol Technologies, Inc.
    Inventors: Raj Bridgelall, Edward Barkan, Stephen Shellhammer, Joseph Campanelli, Joseph Katz, Yajun Li, Daniel R. McGlynn
  • Patent number: 6164540
    Abstract: An optical scanner with plural scan beam generation. Scan angle stress is configured in the beam generation.
    Type: Grant
    Filed: May 22, 1996
    Date of Patent: December 26, 2000
    Assignee: Symbol Technologies, Inc.
    Inventors: Raj Bridgelall, Edward Barkan, Stephen Shellhammer, Joseph Campanelli, Joseph Katz, Yajun Li, Daniel R. McGlynn
  • Patent number: 6123264
    Abstract: A range finder for use with a bar code scanner. An image of a scan line is detected by a sensor array. Distance from the scanner to the bar code symbol is determined from the length of the detected scan line image.
    Type: Grant
    Filed: April 8, 1997
    Date of Patent: September 26, 2000
    Assignee: Symbol Technologies, Inc.
    Inventors: Yajun Li, Joseph Katz, Jerome Swartz, Daniel McGlynn, Edward Barkan
  • Patent number: 6102294
    Abstract: A light scanning system formed on a common substrate comprises a light scanner and a sensor. The light scanner scans light across a target. The sensor detects light reflected from the target and creates a signal representative of the detected light. The light scanner may include a light source and a deflector, such as a micro-machined scan module. The micro-machined scan module may comprise an electrode, a support mounted on the electrode, and a mirror element mounted at one end of the support, wherein a voltage applied between the electrode and mirror element bends the mirror element.
    Type: Grant
    Filed: July 25, 1995
    Date of Patent: August 15, 2000
    Assignee: Symbol Technologies
    Inventors: Jerome Swartz, Miklos Stern, Joseph Katz, Yajun Li
  • Patent number: 6092728
    Abstract: A miniature module emits and focuses a divergent light beam. The focusing module consists of a small-sized light emitter, such as a laser diode, and a micro-optical element seated in a lens holder. The outside diameter of the micro-optical element is 4 mm or less and preferably less than or equal to 2.5 mm. The micro-optical element may be a small conventional lens, a gradient index lens, or one of several types of diffractive optical element. The focal length of the module relative to the light from the emitter is set by sliding the lens holder along its central axis and permanently adhering it in place with respect to the emitter after focusing. During focal adjustment, axial rotation between the lens holder and between the base of the emitter is prevented by a series of notches. The miniature focusing module is smaller, lighter, costs less and may provide a larger relative aperture than the conventional structures currently used for example in solid state laser scanners.
    Type: Grant
    Filed: July 12, 1999
    Date of Patent: July 25, 2000
    Assignee: Symbol Technologies, Inc.
    Inventors: Yajun Li, Simon Bard, Mark Krichever, Joseph Katz, Chin Tan
  • Patent number: 6065678
    Abstract: A CCD based bar code scanner having a focusing system for assisting an operator in determining a proper relative position between the scanner and the bar code. The scanner also includes an illumination system for illuminating the bar code, a collection system for detecting the light reflected from the illuminated bar code and a processor for processing the detected signals.
    Type: Grant
    Filed: November 13, 1998
    Date of Patent: May 23, 2000
    Assignee: Symbol Technologies, Inc.
    Inventors: Yajun Li, Joseph Katz
  • Patent number: 6059188
    Abstract: An integrated optical module for an optical scanner has a lens spaced from a vertical-cavity surface-emitting laser (VCSEL) by a spacer of defined dimensions. The module, in an alternative embodiment, includes a wafer frame, a suspended mirror mounted for oscillation on the frame, a wafer substrate bonded beneath the frame and a wafer cover bonded above the frame. The cover includes a mirror travel stop to protect the mirror against shocks. A VCSEL mounted to the wafer cover produces a beam which is shaped and deflected by a diffractive optical element onto the oscillating mirror. The reflected beam passes out of the module toward an indicia to be read. Large numbers of such devices may be fabricated relatively cheaply using wafer-scale processing and assembly technology. Three large wafers are fabricated corresponding respectively to arrays of substrates, frames and covers. The large wafers are bonded together in a sandwich arrangement, and are then diced to produce the individual scan modules.
    Type: Grant
    Filed: April 12, 1996
    Date of Patent: May 9, 2000
    Assignee: Symbol Technologies
    Inventors: Costanz.o slashed. diFazio, Thomas Mazz, Chinh Tan, Miklos Stern, Henry Grossfeld, Paul Dvorkis, Peter Fazekas, Yajun Li, Joseph Katz, Askold Strat, Greg Martino
  • Patent number: 6036098
    Abstract: A miniature high speed bar code scanning element is detachably mounted within an industry standard PCMCIA card for implementation in personal computing devices.
    Type: Grant
    Filed: January 13, 1998
    Date of Patent: March 14, 2000
    Assignee: Symbol Technologies, Inc.
    Inventors: Ron Goldman, Edward R. Alexander, Yajun Li, Simon Bard, Askold Strat, Joseph Katz, Boris Metlitsky
  • Patent number: 6029893
    Abstract: An optical scanner such as a bar code scanner has a window comprising a holographic optical element through which both the outgoing scanning beam and the returned reflective light passes. The frequency distribution of the element may be chosen to achieve certain desirable characteristics, for example the removal of the dead zone immediately in front of the scanner and control of the beam profile and field of view. The element may be divided up into several separate zones or regions one of which is adapted to control the outgoing beam and the other of which is adapted to receive the incoming reflected light and to focus it onto a photodetector.
    Type: Grant
    Filed: June 17, 1997
    Date of Patent: February 29, 2000
    Assignee: Symbol Technologies, Inc.
    Inventors: Chinh Tan, Yajun Li, Miklos Stern
  • Patent number: 5988508
    Abstract: A reader for electro-optical reading bar code symbols of reduced height, comprises a light source for generating a light beam along an optical path; a pair of oscillatable reflectors in the optical path; a first drive for oscillating the reflectors at different frequencies that are a ratio of about 10%-30% apart to create a scan pattern; and a second drive for rotating the scan pattern about an axis that is generally orthogonal to the scan pattern.
    Type: Grant
    Filed: June 10, 1997
    Date of Patent: November 23, 1999
    Assignee: Symbol Technologies, Inc.
    Inventors: Raj Bridgelall, Joseph Katz, David Goren, Paul Dvorkis, Yajun Li
  • Patent number: 5966230
    Abstract: An integrated scanner for scanning a barcode is formed on a common substrate. The scanner may include a micro-machined mirror, a laser diode, and a detector, mounted on a single substrate or several connected substrates. Lenses can be used to focus a laser beam from the laser diode as well as expand a laser beam deflected by the micro-machined mirror. The scanner may also scan a barcode without using a micro-machined mirror by rotating the laser diode.
    Type: Grant
    Filed: June 7, 1995
    Date of Patent: October 12, 1999
    Assignee: Symbol Technologies, Inc.
    Inventors: Jerome Swartz, Miklos Stern, Joseph Katz, Yajun Li
  • Patent number: 5861615
    Abstract: A hand-held optical reader for reading printed indicia on a remote target includes a light source for generating a scanning light beam and a detector for detecting the light reflected from the printed indicia. The light source and detector are housed within a housing having a window through which the light beam passes from the source to the target for reflection from the target to the detector. The housing includes parallel front and rear faces, each being generally rectangular in shape and having a lower portion and upper portion. The front and rear faces are joined by a substantially planar base face at their lower edges. The window is disposed in the front face with the reader being ergonomically configured so as be comfortably held in the hand of a user, with the user's palm adjacent the rear face to enable the user to direct the scanning light beam at a remote target.
    Type: Grant
    Filed: February 1, 1996
    Date of Patent: January 19, 1999
    Assignee: Symbol Technologies, Inc.
    Inventors: Raj Bridgelall, Joseph Katz, David P. Goren, Paul Dvorkis, Yajun Li