Abstract: A bar code scanner employs an electronic means for causing the light beam to scan a bar code symbol, rather than using a mechanical device to generate the scan. A linear array of light sources, activated one at a time in a regular sequence, may be imaged upon the bar code symbol to simulate a scanned beam. Instead of a single linear array of light sources, a multiple-line array may be employed, producing multiple scan lines. The multiple scan lines may be activated in sequence, or activated simultaneously (time-division or frequency-division multiplexed. The multiple scan lines can provide signal enhancement, noise reduction or fault correction if directed to the same bar code pattern. Multiple scan lines may be generated using a single light source and a beam splitter, with mechanical scanning, as well as by the sequentially-activated light sources. Multiple simultaneous scan lines may be employed to generate a raster scan at lower mechanical scan frequency.

Abstract: A bar code scanning system including an optical scanner for scanning a target symbol, such as a bar code, and generating a corresponding electrical signal. The scanner housing may be mounted to a single finger ring support, which can be cylindrical in shape. The scanner housing may include a scanner activation switch, which may be of the voice recognition type. A transmitter for transmitting the analog or digitized electrical signal, either by wire or RF signal, to a receiver on the user's person is also included in the scanner housing. A decoder is preferably included within the receiver housing. The receiver housing may also have a display for displaying decoded data and a keyboard for inputting entry data. Signal processing circuitry for digitizing the electrical signals generated by the scanner may be included either in the scanner or receiver housing. The receiver housing also may include an RF transmitter for transmitting the decoded data and any entry data to a separate computer unit.

Abstract: An optical reading system for reading optically encoded information represented by a symbol on a target includes a rotational shaft, a light emitter for producing a beam of light to scan a path through a scan field, and a light detector for detecting light reflected from the symbol to read the optically encoded information. A means for oscillating the light emitter and light detector about a longitudinal axis of the rotational shaft is also provided. At least one electrical conductor is connected to each of the light emitter and light detector for providing electrical energy thereto. Each electrical conductor is affixed between distal ends thereof at a point coincident with a point on the longitudinal axis of the rotational shaft.

Abstract: A system for scanning bar code symbols on articles moving at a given speed senses an article at a predetermined location and determines an orientation of a bar code symbol on the article using an imaging camera. In response to determinations of a symbol location, orientation, size or type, the scanning system adjusts a scanning speed, shape and/or orientation of the light beam pattern and a location of the light beam pattern. The resulting light beam is directed at the bar code symbol location and a signal corresponding to the reflected light beam portion is generated. If the decode is not valid, the bar code symbol is rescanned.

Abstract: Disclosed are methods and apparatus for automatically aligning the field of view of a two dimensional bar code reading device with a randomly oriented two-dimensional bar code symbol wherein the symbol comprises a unique pattern located contiguously on at least one side thereof. One method is implemented in a laser based embodiment by scanning the symbol with a laser scan line extending through the border pattern (which is a PDF417 start codeword), measuring the length of the start codeword detected by the scan line, and rotating the laser scan line by a predetermined amount. This is repeated for a predetermined number of times, and the rotation angle at which the codeword length is smallest is determined by performing a least squares fit of the measured codeword lengths and rotation angles. The raster pattern is then rotated to the determined rotation angle so as to be aligned with the symbol for subsequent scanning and decoding.

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 of the scan head and reduces the temperature sensitivity of the scan head. The scan head may include an optical sensor for detecting light reflected from scanned symbols. Alternatively, the separate unit may house the sensor, and the same fiber or an additional fiber will collect the reflected light and transmit that light back to the sensor. The invention also encompasses a number of electromagnetic and piezoelectric systems for producing a scanning motion of the beam emitted by the scan head.

Abstract: A bar code reader capable of working over a wider range of working angle and for a wider range of bar code densities, using improved optics and sensing elements. The optics and sensing elements and/or the associated circuitry are arranged to provide two channels of data derived from 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. The different resolution of the two channels can be provided using different size photodetection areas, e.g., small and large groups of active areas on a sensor array.

Abstract: A scanning system for orienting bar codes use a first stage made up of a low-resolution scanner and a digital signal processor (DSP), and a second stage made up of a high-resolution scanner and a decoder. The first stage scans the surface of an object to obtain an image, which the DSP analyzes to determine the location and orientation of any bar codes. The DSP does this by dividing the image into windows and finding the windows which contain part of a bar code. The second stage receives the results from the DSP and scans the bar code on the object.

Abstract: Optical scanning of one- and two-dimensional barcode symbols is carried out first in an aim mode wherein the symbol is scanned using a first scan pattern that is relatively small and dense so as to be visible to the user and thereafter using a second, larger and more robust scan pattern for decoding. During aiming, the symbol is partially decoded to determine type and orientation, and this information is applied to control the angle of the scan pattern produced, the rate at which the scan pattern is increased for optimum decoding, and the ultimate pattern size. Preferred scan patterns, as well as unique scan mechanisms, are described.

Abstract: A holographic grating element is provided which enables tracing different scan lines. The element is divided into a plurality of sectors. A first grating pattern is provided which diffracts a beam in one direction, and a second grating pattern is next to the first and diffracts the scan beam in the reverse direction. Sectors can be produced with different sector sizes to enable scanning at different rates in the reverse direction, or in successive scans in the same direction. Angle relationships are described to produce diffraction patterns for a desired relationship between disc rotation and the angle of the scan line.

Abstract: A scanning system has a plurality of optical scan units. Each optical scan unit includes means for emitting light toward an item bearing an indicia. Each optical scan unit also includes means for receiving light reflected from the indicia and generating signals corresponding to the intensity of the reflected light. Also provided is a central control unit which includes means for combining together signals corresponding to the signals generated by at least two of the scan units to fully decode information contained on the indicia.

Abstract: A scan head is adjustably mounted in a ball-and, socket joint on a scan module or housing of an electro-optical system for reading coded indicia. The scan head is movable about three mutually orthogonal axes intersecting within the scan head, thereby steering a light beam emitted from the head and/or steering a field of view of a sensor.

Abstract: A symbol scanning system which adaptively changes scanning system parameters including light beam pattern and focus to improve barcode readability. The scanning system including; a scanner, responsive to coordinate control signals, for directing a light beam in a pattern at a symbol at a predetermined location, detecting a reflected portion of the light beam, and generating a feedback signal corresponding to the detected portion of the reflected light beam, a microprocessor, responsive to the feedback signal, for generating pattern control signals, and a pattern generator for generating the coordinate control signals in responsive to the pattern control signals and for determining the light beam pattern.

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.

Abstract: In order to improve security for holographic labels which are positioned on a substrate base, a bar code symbol with regions of different light reflective properties is holographically recorded on the base. The base may be, for example an information card, such as a credit card, a label, or a container for a product. The bar code symbol can be recorded so that it is visible to the eye in white light (e.g., as a rainbow hologram) or so that it requires an appropriate reference beam for reconstruction. A reading apparatus (e.g., a bar code reader) directs light at the holographic bar code symbol and detects the reflected optical information with a detector such as a CCD array. The reading apparatus can be a stand-alone device or, in the case of a credit card, can be incorporated into a conventional swiper for reading magnetic information on a strip on the card. A non-holographic bar code symbol can also be provided on or near a holographic display element, e.g., a rainbow hologram.

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.

Abstract: A method of manufacturing a bar code reader of the type including a scanner for generating a moving light beam directed toward a target and sweeping the bar code symbol to be read. A photodetector receives the reflected light from such symbol, and processing circuitry determines whether the signal received represents a valid symbol. The processing circuitry has adjustable gain, bandwidth, and digitizer threshold characteristics which are set during the manufacturing process.

Abstract: A device for reading indicia on a target in which the indicia has regions of differing light reflectivity. The device directs a light beam toward the indicia, and collects reflected light from the indicia. The focus of the light beam is varied to enable the device to read indicia at different working distances, and the maximum scanning angle of the light beam is varied in operative correlation with the focus.

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.

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.