Clock Generating Or Sampling Circuit Patents (Class 235/462.28)
  • Patent number: 9843339
    Abstract: An asynchronous pulse domain to synchronous digital domain converter for converting pulse domain signals in an input asynchronous pulse domain data stream to synchronous digital domain signals in a data output stream. The converter comprises a plurality of counters arranged in a ring configuration with only one counter in the ring being responsive at any given time to positive and negative going pulses in the input asynchronous pulse domain data stream, each counter, when so responsive, counting a number of time units between either (i) a positive going pulse and an immediately following negative going pulse or (ii) a negative going pulse and an immediately following positive going pulse, the counts of the counters when so responsive being synchronously converted to synchronous digital domain signals in the data output stream. The disclosed asynchronous pulse domain to synchronous digital domain converter can be used with spike domain signals if desired.
    Type: Grant
    Filed: August 26, 2016
    Date of Patent: December 12, 2017
    Assignee: HRL Laboratories, LLC
    Inventors: Yen-Cheng Kuan, Randall White, Zhiwei A. Xu, Donald A. Hitko, Peter Petre, Jose Cruz-Albrecht, Alan E. Reamon
  • Patent number: 9530041
    Abstract: Embodiments of the present invention generally relate to data processing, and further the embodiments of the invention relate to a method of processing a visible coding sequence and a system thereof, a method of playing a visible coding sequence and a system thereof. The present invention creatively proposes a scheme of determining sampling rate with synchronized frames to realize effective processing of a visible coding sequence. The scheme of processing a visible coding sequence according to the present invention is helpful for visible coding synchronization on the capturing side, enabling the capturing side to determine appropriate sampling rate and sampling timing, and thus effectively acquire the visible coding sequence, which may not only reduce resource waste, but also acquire a complete visible coding sequence.
    Type: Grant
    Filed: March 15, 2016
    Date of Patent: December 27, 2016
    Assignee: International Business Machines Corporation
    Inventors: Jiexin Jiao, Mengxiang Lin, Song Song, XiaoFeng Wang
  • Publication number: 20140299665
    Abstract: A method is disclosed for decoding a decodable symbol using an optical reader having a 2D image sensor that is configured to operate in a partial frame capture operating mode. In a partial frame operating mode, the reader clocks out and captures at least one partial frame of image data having image data corresponding to less than all of the pixels of an image sensor pixel array. In one embodiment, the reader operating in a partial frame operating mode captures image data corresponding to a linear pattern of pixels of the image sensor, reads the image data, and attempts to decode for a decodable bar code symbol which may be represented in the image data.
    Type: Application
    Filed: April 21, 2014
    Publication date: October 9, 2014
    Applicant: Hand Held Products, Inc.
    Inventors: Charles P. Barber, Carl W. Gerst, III, George S. Smith, II, Robert M. Hussey, Robert C. Gardiner, Matthew W. Pankow
  • Publication number: 20140197238
    Abstract: There is set forth herein an indicia reading terminal having data format conversion capabilities. The indicia reading terminal includes an image sensor integrated circuit with an image sensor array comprising a plurality of pixels. The image sensor integrated circuit is configured to output image data in a first data format to a data formatting circuit for conversion to image data in a second data format. The data formatting circuit is configured to provide the image data in the second data format to the at least one data interface of a microprocessor integrated circuit, which is operative to transfer image data received by the at least one data interface into memory of the indicia reading terminal. A CPU of the microprocessor integrated circuit is operative for executing a decoding algorithm for processing image data in the memory for attempting to decode at least one symbol represented in the memory.
    Type: Application
    Filed: September 9, 2011
    Publication date: July 17, 2014
    Applicant: METROLOGIC INSTRUMENTS, INC.
    Inventors: Yong Liu, Xiaoxun Zhu, Xi Tao, Ynjiun Paul Wang
  • Patent number: 8666006
    Abstract: Systems and methods are disclosed for improving digital feed-forward data recovery of high speed data from a received data stream in a data transceiver or receiver where the receiver clock is asynchronous to the transmitter clock used to transmit the received data stream. In one example, the received data stream is oversampled using N evenly-spaced multi-phase clocks. The oversampled data are packed into a data block. Data transition edges of the oversampled data in the data blocks with respect to multi-phase clocks are tracked. The tracked data transition edges are used to determine the length of a decision window and to further divide the oversampled data into groups of bits that are hypothesized to be samples of the same received data symbol. Bit mapping is performed on the decision window to recover the received data symbol. By tracking the movement of data transition edges, the technique enhances data recovery capability.
    Type: Grant
    Filed: February 25, 2011
    Date of Patent: March 4, 2014
    Assignee: SMSC Holdings. S.a.r.l.
    Inventors: Wei Fu, Yuping Luo, Yanggao Qiu, Christopher Thomas
  • Publication number: 20130248605
    Abstract: A method for decoding a decodable symbol using an optical reader having a 2D image sensor that is configured to operate in a partial frame capture operating mode. In a partial frame operating mode, the reader clocks out and captures at least one partial frame of image data having image data corresponding to less than all of the pixels of an image sensor pixel array. In one embodiment, the reader operating in a partial frame operating mode captures image data corresponding to a linear pattern of pixels of the image sensor, reads the image data, and attempts to decode for a decodable bar code symbol which may be represented in the image data.
    Type: Application
    Filed: May 13, 2013
    Publication date: September 26, 2013
    Inventors: Charles P. Barber, Carl W. Gerst, III, George S. Smith, II, Robert M. Hussey, Robert C. Gardiner, Matthew W. Pankow
  • Patent number: 8485444
    Abstract: An apparatus and method for reading symbol information enabling improvement of decoding accuracy, not being affected by the condition of a reflection coefficient waveform of a reflected light beam and the kind of symbol information to be read. The method includes: reading a reflected light beam from symbol information irradiated with a light beam; detecting peak values in a reflection coefficient waveform of the reflected light beam; calculating a first peak value according to a peak value at a high reflection coefficient side (white level) among the peak values detected; calculating a second peak value according to a peak value at a low reflection coefficient side (black level) among the peak values detected; and calculating a binarization threshold based on the first peak value and the second peak value.
    Type: Grant
    Filed: February 1, 2011
    Date of Patent: July 16, 2013
    Assignee: Nidec Sankyo Corporation
    Inventor: Hiroshi Nakamura
  • Publication number: 20120118974
    Abstract: An optical reader for decoding an encoded symbol character of a symbology includes a scan data signal processor having as an input a scan data signal encoding information representative of the encoded symbol character. The scan data signal processor includes a first time delay stage adapted to provide a primary phase waveform from the scan data signal, a second time delay stage adapted to provide an early phase waveform from the scan data signal, and a third time delay stage adapted to provide a delayed phase waveform from the scan data signal. The early phase waveform has a propagation delay less than the primary phase waveform, and the delayed phase waveform has a propagation delay greater than the primary phase waveform. The scan data signal processor further includes a peak window detection stage for generating a peak window timeframe when an amplitude of the primary phase waveform is greater than, less than, or equal to both an amplitude of the early phase waveform and the delayed phase waveform.
    Type: Application
    Filed: November 17, 2010
    Publication date: May 17, 2012
    Applicants: Hand Held Products, Inc., Metrologic Instruments, Inc.
    Inventors: Gennady Germaine, Tao Xian, Chen Feng, Ynjiun Wang, Xiaoxun Zhu, Stephen Colavito, Robert Blake
  • Patent number: 8134621
    Abstract: An imaging system comprises a rolling-reset imager that forms an electronic image of an object, a light source illuminating the object with pulsed light, and a bandpass optical filter disposed between the object and the rolling-reset imager. The pulsed light has an illumination frequency spectrum and an illumination pulse width defining an effective exposure time for forming the image of the object. The bandpass optical filter has a frequency pass band permitting transmission of a significant portion of the illumination frequency spectrum while at least approximately inhibiting transmission of at least some light having frequencies outside the illumination frequency band. An imaging method illuminates an object with light in a given frequency range, so that the illumination light reflects from the object along with background light. The method filters the reflected light so as to attenuate at least some of the background light by a greater attenuation factor than the illumination light.
    Type: Grant
    Filed: February 26, 2009
    Date of Patent: March 13, 2012
    Assignee: Datalogic ADC, Inc.
    Inventors: Bryan L. Olmstead, Alan Shearin
  • Publication number: 20110163165
    Abstract: There is set forth herein an indicia reading terminal having an illumination subsystem for projection of an illumination pattern, the illumination subsystem having at least one light source, the illumination subsystem being switchable between a first state and a second state, wherein the illumination subsystem in the second state projects illumination light at a projection angle that is more narrow than a projection angle of illumination light projected by the illumination subsystem when the illumination subsystem is in the first state. An indicia reading terminal can include an imaging subsystem including an image sensor array and an imaging lens for focusing an image of a target onto the image sensor array, the imaging lens being a variable imaging lens and having a first lens setting at which the lens assembly has a relatively nearer plane of optimum focus and a second lens setting at which the imaging lens has a relatively farther plane of optimum focus setting.
    Type: Application
    Filed: January 7, 2010
    Publication date: July 7, 2011
    Applicants: Metrologic Instruments, Inc., Hand Held Instruments
    Inventors: Yong Liu, Xiaoxun Zhu, Ynjiun Paul Wang
  • Publication number: 20110114717
    Abstract: Barcodes stored by mobile devices can be used in commerce. In sending barcode data optically from a display backlight of a mobile communication device to a barcode scanner optical receiver, the transmitted data bit time needs to be compatible with the frequency range the barcode scanner is designed to receive. The disclosed methods and mobile devices can send barcode data optically at different frequencies from a modulated display backlight to different models/makes of laser barcode scanners that may be used at a point of sale (POS). The disclosed are methods and devices for processing the bit time mix choices make a determination of bit time mix choices based upon predetermined criteria. Location of the device is an example of predetermined criteria. A location may have a particular bit time mix signature that may be accessed, for example, in a look up table.
    Type: Application
    Filed: November 16, 2009
    Publication date: May 19, 2011
    Applicant: MOTOROLA, INC.
    Inventors: Huinan J. Yu, Jun Jiang, John R. St. Peter
  • Patent number: 7845562
    Abstract: A decoding system is provided having decoder configured to determine a clock indicator from alignment data sensed by a sensor used to interact with coded data in a sensing region, update, from the determined clock indicator, a phase-locked loop (PLL), determine, from the updated PLL, a relative position between the sensing region and a data portion of the coded data sensed by the sensor, and decode, from the determined relative position, the sensed data portion.
    Type: Grant
    Filed: September 14, 2009
    Date of Patent: December 7, 2010
    Assignee: Silverbrook Research Pty Ltd
    Inventors: Paul Lapstun, Kia Silverbrook
  • Patent number: 7775434
    Abstract: A bar-code reading apparatus includes a differential processor which generates a differential signal from an electric signal corresponding to an intensity of light reflected from a bar code, an extreme value detector which detects each extreme value of the differential signal and generates extreme value information including at least an electric signal value of the detected extreme value, a voltage difference calculator which calculates a voltage difference in electric signal between a target extreme value and at least one of extreme values adjacent thereto for each extreme value in the extreme value information, and an extreme value verifying unit which compares the voltage difference with a predetermined threshold value and determines the validity of the extreme value corresponding to the voltage difference for each voltage difference. Information encoded as the bar code is decoded by using extreme value information of the valid extreme value.
    Type: Grant
    Filed: May 7, 2008
    Date of Patent: August 17, 2010
    Assignee: Olympus Corporation
    Inventor: Tomomi Mashiko
  • Publication number: 20100001074
    Abstract: A decoding system is provided having decoder configured to determine a clock indicator from alignment data sensed by a sensor used to interact with coded data in a sensing region, update, from the determined clock indicator, a phase-locked loop (PLL), determine, from the updated PLL, a relative position between the sensing region and a data portion of the coded data sensed by the sensor, and decode, from the determined relative position, the sensed data portion.
    Type: Application
    Filed: September 14, 2009
    Publication date: January 7, 2010
    Inventors: Paul Lapstun, Kia Silverbrook
  • Patent number: 7600688
    Abstract: A system for decoding coded data provided on or in a surface is provided. The coded data includes at least one data portion arranged on or in the surface and alignment data at least partially indicative of at least one clock indicator. The system includes a sensor which senses data provided in a sensing region and a decoder. The sensor senses at least part of the alignment data and at least part of the at least one data portion. The decoder determines, using the sensed alignment data part, the clock indicator, updates, using the clock indicator, a PLL, determines, using the PLL, a relative position between the sensing region and the at least one sensed data portion part, and at least partially decodes, using the relative position, the at least one data portion part.
    Type: Grant
    Filed: June 23, 2008
    Date of Patent: October 13, 2009
    Assignee: Silverbrook Research Pty Ltd
    Inventors: Paul Lapstun, Kia Silverbrook
  • Publication number: 20090153718
    Abstract: An imaging system comprises a rolling-reset imager that forms an electronic image of an object, a light source illuminating the object with pulsed light, and a bandpass optical filter disposed between the object and the rolling-reset imager. The pulsed light has an illumination frequency spectrum and an illumination pulse width defining an effective exposure time for forming the image of the object. The bandpass optical filter has a frequency pass band permitting transmission of a significant portion of the illumination frequency spectrum while at least approximately inhibiting transmission of at least some light having frequencies outside the illumination frequency band. An imaging method illuminates an object with light in a given frequency range, so that the illumination light reflects from the object along with background light. The method filters the reflected light so as to attenuate at least some of the background light by a greater attenuation factor than the illumination light.
    Type: Application
    Filed: February 26, 2009
    Publication date: June 18, 2009
    Applicant: Datalogic Scanning, Inc.
    Inventors: Bryan L. Olmstead, Alan Shearin
  • Patent number: 7516896
    Abstract: A MEMs scanning device has a variable resonant frequency. In one embodiment, the MEMs device includes a flexible arm that extends from an oscillatory body. An electrical field applies a force to the flexible arm, thereby bending the flexible arm to change the moment of inertia of the oscillatory body and a secondary mass carried by the flexible arm. The shifted combined center of mass changes the resonant frequency of the MEMs device. In another embodiment, an absorptive material forms a portion of a torsional arm that supports the oscillatory body. The mechanical properties of the absorptive material can be varied by varying the concentration of a gas surrounding the absorptive material. The varied mechanical properties change the resonant frequency of the scanning device. A display apparatus includes the scanning device and the scanning device scans about two or more axes, typically in a raster pattern.
    Type: Grant
    Filed: February 18, 2005
    Date of Patent: April 14, 2009
    Assignee: Microvision, Inc.
    Inventors: Mark P. Helsel, David W. Wine
  • Patent number: 7499090
    Abstract: An imaging system comprises a rolling-reset imager that forms an electronic image of an object, a light source illuminating the object with pulsed light, and a bandpass optical filter disposed between the object and the rolling-reset imager. The pulsed light has an illumination frequency spectrum and an illumination pulse width defining an effective exposure time for forming the image of the object. The bandpass optical filter has a frequency pass band permitting transmission of a significant portion of the illumination frequency spectrum while at least approximately inhibiting transmission of at least some light having frequencies outside the illumination frequency band.
    Type: Grant
    Filed: January 27, 2005
    Date of Patent: March 3, 2009
    Assignee: Datalogic Scanning, Inc.
    Inventors: Bryan L. Olmstead, Alan Shearin
  • Publication number: 20080283610
    Abstract: A system for decoding coded data provided on or in a surface is provided. The coded data includes at least one data portion arranged on or in the surface and alignment data at least partially indicative of at least one clock indicator. The system includes a sensor which senses data provided in a sensing region and a decoder. The sensor senses at least part of the alignment data and at least part of the at least one data portion. The decoder determines, using the sensed alignment data part, the clock indicator, updates, using the clock indicator, a PLL, determines, using the PLL, a relative position between the sensing region and the at least one sensed data portion part, and at least partially decodes, using the relative position, the at least one data portion part.
    Type: Application
    Filed: June 23, 2008
    Publication date: November 20, 2008
    Inventors: Paul Lapstun, Kia Silverbrook
  • Patent number: 7380721
    Abstract: A barcode sensor package has an optical emitter circuit and an optical detector circuit which are formed as one or more integrated optical circuits disposed in a housing which has a reading surface and one or more apertures located between the optical emitter and detector circuits. The optical emitter circuit has an emitter die, such as a vertical cavity surface emitting laser (VCSEL), for emitting a light beam and a diffraction optical element disposed on the emitter die for focusing the light beam to a bar code. The optical detector circuit has a photodetector die, such as a phototransistor, for detecting reflective light and another diffraction optical element disposed on the photodetector die for guiding light reflected from the bar code to the detector. The diffraction optical elements are fabricated by patterning optical layers, deposited on respective emitter and detector dies, using photolithograph or a direct write process.
    Type: Grant
    Filed: August 22, 2006
    Date of Patent: June 3, 2008
    Assignee: Honeywell International Inc.
    Inventor: Wenwei Zhang
  • Patent number: 7354000
    Abstract: A method and system used in the barcode sensing process are disclosed, in which at least two instances of an optical signal are obtained from the same barcode in different time periods, and digitized by a first digitizer with a first threshold. The digitized results from the at least two instances are then applied with an AND algorithm to eliminate the noise, whereby create a correct digitized output. Preferably, the instances of the signal are also digitized by a second digitizer with a second threshold, which are used to synchronize the timing of the digitized results created by the first digitizer. The second threshold is preferably larger than the first threshold.
    Type: Grant
    Filed: May 5, 2005
    Date of Patent: April 8, 2008
    Assignee: Optoelectronics Co., Ltd.
    Inventors: Susumu Nakano, Kentaro Takahashi, Hiroshi Hayakawa
  • Patent number: 7278577
    Abstract: An image input system includes a solid state image pickup device and a preprocessor for performing correlated double sampling amplification on an output of the image pickup device and outputting a video signal. The preprocessor has a correlated double sampling amplifier for outputting signal information corresponding to a difference voltage between the black level in a feedthrough period of the image pickup device and a signal level in a charge signal output period; and an offset cancelling circuit for cancelling an offset voltage corresponding to the difference voltage in a state where the image pickup device is optically interrupted to the input terminal of the correlated double sampling amplifier. The correlated double sampling amplifier cancels out the offset voltage and the offset cancelling voltage as signal components of polarities opposite to each other, so that circuits following the correlated double sampling amplifier are not influenced by the offset voltage.
    Type: Grant
    Filed: April 14, 2004
    Date of Patent: October 9, 2007
    Assignees: Renesas Technology Corp., Hitachi Tohbu Semiconductor, Ltd.
    Inventors: Kouichi Yahagi, Masumi Kasahara, Hiroki Nakajima
  • Patent number: 7065645
    Abstract: A visual tag having an imprinted image, a processor for calculating a response string corresponding to the content of the imprinted image and a challenge string, and a changeable screen to display the response string in machine-readable symbols. An authentication device reads the displayed symbols, and authenticates the displayed contents corresponding to the challenge string. The challenge string is generated either according to a random generator within the authentication device, or according to a real-time clock. A plurality of tags or objects can be authenticated and spotted within an image. The tag can also authenticate inputted messages and credentials.
    Type: Grant
    Filed: February 16, 2003
    Date of Patent: June 20, 2006
    Inventor: Mordechai Teicher
  • Patent number: 6945462
    Abstract: An optical information reading apparatus applies light to an object to be read such as a bar code symbol, photoelectrically converts by a photodetector element a light image formed by the reflection light, and processes the obtained electric signal to output code data. Among the portions performing the signal processing, at least a data converter (13) for converting a photoelectrically converted electric signal into a digital signal, a digital signal calculation unit (17) for calculating the digital signal and generating code data indicating information of an object to be read, an input accumulation unit (20) for accumulating the code data, and a timing control unit (12) for controlling operation timings of these components are arranged on a single substrate as a multipurpose processing circuit block (10).
    Type: Grant
    Filed: May 24, 2002
    Date of Patent: September 20, 2005
    Assignee: Optoelectronics Co., Ltd.
    Inventors: Sachio Tsukuda, Susumu Nakano
  • Patent number: 6935564
    Abstract: A systems and method generate a progressively corrected scan signal, the progressively corrected scan signal having a magnitude independent of spectral reflectance from a background near a target. One of the methods involves generating a baseline signal by sampling light reflected from the target and background before transmitting a light scan at the target, generating a detected signal by receiving light reflected from the target and background while transmitting the light scan at the target, and subtracting the baseline signal from the detected signal to form the progressively corrected scan signal. One circuit embodiment produces an average level independent output signal from an input signal subject to fluctuations in average level.
    Type: Grant
    Filed: July 30, 2001
    Date of Patent: August 30, 2005
    Assignee: Bayer Healthcare LLC
    Inventors: Paul E. Purpura, Jerry Harper
  • Patent number: 6932273
    Abstract: A scanner comprising a data reader integrated with a weigh scale includes a processor that recognizes specific types of optical codes. In a preferred embodiment, when a weighable item is read by the data reader, a fixed delay timer, which prevents multiple reporting of the same item data before the timer expires, is not allowed to expire until after the item is removed from the weigh scale. In an alternative embodiment, the timer is set for one of several possible delay times depending on the type of symbol being read. The timer is not allowed to expire until the most recently reported data is no longer observed by the reader. Thus, the likelihood that multiple reads of the same symbol will be reported is greatly reduced.
    Type: Grant
    Filed: January 20, 2004
    Date of Patent: August 23, 2005
    Assignee: PSC Scanning, Inc.
    Inventor: Alexander M. McQueen
  • Patent number: 6871785
    Abstract: The method for compensating undesired variations in an electrical signal generated by a sensor of an optical code reader comprises the steps of generating an envelope signal starting from the electrical signal generated by the sensor and normalizing the electrical signal with respect to the envelope signal. Preferably, the envelope signal is filtered with a low-pass filter before being normalized so as to eliminate steps and edges which may cause distortions during normalization, and the normalized signal is amplified in a controlled way so as to supply an output signal ranging between two values having preset amplitudes. Normalization is carried out by dividing, point by point, the electrical signal by the envelope signal, in the case of continuous analog processing; alternatively, in presence of discrete-time signals, normalization is carried out by subtracting the envelope signal from the electrical signal.
    Type: Grant
    Filed: December 19, 2000
    Date of Patent: March 29, 2005
    Assignee: Datalogic S.p.A
    Inventors: Marco Piva, Maurizio Bianchi
  • Patent number: 6840453
    Abstract: An optical scanning apparatus, such as a bar code scanner, for reading 360 degrees of, e.g., tray commodities. A first scanning pattern is emitted almost in the horizontal direction to an installation surface of the apparatus, and a second scanning pattern is emitted from an upper portion to a lower portion of the apparatus, toward the installation surface, via a window provided vertical to the installation surface.
    Type: Grant
    Filed: October 31, 2002
    Date of Patent: January 11, 2005
    Assignee: Fujitsu Limited
    Inventor: Masanori Ohkawa
  • Patent number: 6783073
    Abstract: An image input system includes a solid state image pickup device and a preprocessor for performing correlated double sampling amplification on an output of the image pickup device and outputting a video signal. The preprocessor has a correlated double sampling amplifier for outputting signal information corresponding to a difference voltage between the black level in a feedthrough period of the image pickup device and a signal level in a charge signal output period; and an offset cancelling circuit for cancelling an offset voltage corresponding to the difference voltage in a state where the image pickup device is optically interrupted to the input terminal of the correlated double sampling amplifier. The correlated double sampling amplifier cancels out the offset voltage and the offset cancelling voltage as signal components of polarities opposite to each other, so that circuits following the correlated double sampling amplifier are not influenced by the offset voltage.
    Type: Grant
    Filed: July 23, 2002
    Date of Patent: August 31, 2004
    Assignees: Renesas Technology Corp., Hitachi Tohbu Semiconductor, Ltd.
    Inventors: Kouichi Yahagi, Masumi Kasahara, Hiroki Nakajima
  • Patent number: 6698658
    Abstract: A scanner comprising a data reader integrated with a weigh scale includes a processor that recognizes specific types of optical codes. In a preferred embodiment, when a weighable item is read by the data reader, a fixed delay timer, which prevents multiple reporting of the same item data before the timer expires, is not allowed to expire until after the item is removed from the weigh scale. In an alternative embodiment, the timer is set for one of several possible delay times depending on the type of symbol being read. The timer is not allowed to expire until the most recently reported data is no longer observed by the reader. Thus, the likelihood that multiple reads of the same symbol will be reported is greatly reduced.
    Type: Grant
    Filed: July 12, 2001
    Date of Patent: March 2, 2004
    Assignee: PSC Scanning, Inc.
    Inventor: Alexander M. McQueen
  • Patent number: 6499663
    Abstract: An image input system includes a solid state image pickup device and a preprocessor for performing correlated double sampling amplification on an output of the image pickup device and outputting a video signal. The preprocessor has a correlated double sampling amplifier for outputting signal information corresponding to a difference voltage between the black level in a feedthrough period of the image pickup device and a signal level in a charge signal output period; and an offset cancelling circuit for cancelling an offset voltage corresponding to the difference voltage in a state where the image pickup device is optically interrupted to the input terminal of the correlated double sampling amplifier. The correlated double sampling amplifier cancels out the offset voltage and the offset cancelling voltage as signal components of polarities opposite to each other, so that circuits following the correlated double sampling amplifier are not influenced by the offset voltage.
    Type: Grant
    Filed: April 18, 2000
    Date of Patent: December 31, 2002
    Assignees: Hitachi, Ltd., Hitachi Tohbu Semiconductor, Ltd.
    Inventors: Kouichi Yahagi, Masumi Kasahara, Hiroki Nakajima
  • Patent number: 6491224
    Abstract: An optical scanning apparatus, such as a bar code scanner, for reading 360 degrees of, e.g., tray commodities. A first scanning pattern is emitted almost in the horizontal direction to an installation surface of the apparatus, and a second scanning is pattern emitted from an upper portion to a lower portion of the apparatus, toward the installation surface, via a window provided vertical to the installation surface.
    Type: Grant
    Filed: October 15, 1999
    Date of Patent: December 10, 2002
    Assignee: Fujitsu Limited
    Inventors: Masanori Ohkawa, Toshiyuki Ichikawa, Hiroshi Watanuki, Kozo Yamazaki
  • Patent number: 6484944
    Abstract: An optoelectronic device for acquiring images of planes, such as bar codes, includes a deflector for deflecting an incident beam emitted by a light source such as an oscillating or rotating cyclic polygonial deflector or mirror. A driver osscilates or rotates the deflector in such a way that the incident beam describes, during each cycle, angular scanning adapted to generate at least one elementary scanning line on the plane. A closed loop control circuit controls the driver and is connected, on the one hand, to the clock in order to receive the transfer signal &PHgr;TG and, on the other hand, to the driver and adapted to synchronize the beginning of each scanning cycle in phase and frequency with the signal &PHgr;TG emitted by the clock.
    Type: Grant
    Filed: September 6, 2000
    Date of Patent: November 26, 2002
    Assignee: Intermec IP Corp.
    Inventors: Pierre-Marie Manine, Jean-Louis Massieu, Bernard Puybras, Bernard Serres, Serge Thuries
  • Patent number: 6382512
    Abstract: A signal reading control apparatus for barcode scanner comprises a Decoder and a laser engine. The laser engine includes an Analog circuit, a Tone Decoder, a Time Delay, a Flip Flop, an Oscillation circuit, a judging circuit, a scanner structure, a laser beam output, and a light detect sensor. When the button key of the barcode scanner is pressed, the scanner structure is not activated temporarily. Instead, a constant frequency oscillation wave is applied on a laser diode which emits photo points in an oscillating fashion. When a scanning object enters the readable range, the light detect sensor of the barcode scanner will receive a reflection signal of same frequency as the one applied on the photo points. When the signal frequency is same as the one emitting by the laser diode, it is confirmed that the object has entered the readable range.
    Type: Grant
    Filed: April 9, 2001
    Date of Patent: May 7, 2002
    Inventor: Yu-Chun Chang
  • Patent number: 6382511
    Abstract: A system for digital barcode processing. A light reflected from a barcode is captured by a photodetector to produce a photocurrent. The photocurrent is converted to a voltage, amplified and filtered to produce a photovoltage. The photovoltage is differentiated to form a first derivative signal and the first derivative signal is converted to a digital first derivative signal and processed to identify logic transitions represented by the barcode. The processing system subjects the photosignal to Gaussian filtering and differentiates the digital first derivative signal to form a second derivative signal. The digital first derivative signal is compared against a positive and a negative threshold and the second derivative signal is examined to detect zero crossings.
    Type: Grant
    Filed: April 26, 2000
    Date of Patent: May 7, 2002
    Assignee: NCR Corporation
    Inventors: Hong Tang, Donald Alexander Collins, Jr., Kenneth Joseph Fabian, Barry Myron Merganthaler
  • Patent number: 6176429
    Abstract: A multi-function optical reader comprises an photosensor, such as a charge-device (CCD), and signal conditioning and processing circuitry including separate channels for handling data in different formats. A bar code processing channel digitizes the scan signal according to light and dark features using a first-derivative technique, and an OMR processing channel uses an adaptive threshold to adapt to different light conditions and provide a boundary line for digitizing light and dark features of the target scan line. A feature measurement circuit measures the widths of the light and dark regions as derived by the separate processing channels, and provides the feature measurements to a decoding system or host terminal processor. The scan rate of the optical reader can be adjusted according to the data format to be read or the level of ambient light, to avoid saturation. The optical reader can provide multiple depth-of-field zones, both internal and external to an optical reader housing.
    Type: Grant
    Filed: July 17, 1998
    Date of Patent: January 23, 2001
    Assignee: PSC Scanning, Inc.
    Inventors: Brad R. Reddersen, Edward C. Bremer, Chay K. La, Stephen P. Deloge, Raymond J. Boyd, Shane P. Cooper, Ilya Zaverukha