摘要:
An optical scanner includes a light source for producing a light beam for scanning a target wherein the light beam scans a target at a first low frequency and the beam also dithers in a direction orthogonal to the scanning direction at a second, high frequency. The dithering motion can be imparted by a oscillating mirror and allows improved reading of, for example, bar code symbols. In addition an optical scanner includes a laser light source producing a laser light beam into which a time-varying phase is introduced in order to reduce laser speckle noise.
摘要:
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.
摘要:
A system for reading indicia such as bar code symbols having a scanner for generating a scanning light beam directed toward a symbol to be read; a first actuator manually displaceable from a first position to a second position for producing a first light beam for aiming or positioning the reader, and a second actuator manually displaceable from a first position to a second position for initiating a scanning beam pattern for reading the symbol. The actuators are independently operative of each other. A detector receives the reflected light from the symbol and produces electrical signals corresponding to data represented by the symbol. A graphical user interface simplifies system control functions.
摘要:
High speed scanning arrangements in scanners for reading bar code symbols by oscillating a scanner component in single or multi-axis scan patterns.
摘要:
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.
摘要:
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.
摘要:
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.
摘要:
Several embodiments are disclosed of bar code readers in which one or more piezoelectric bimorph elements are utilized as a drive element in the optical system thereof. In different embodiments, the piezoelectric bimorph element is utilized in the scanning function of the bar code reader optical system, or in a variable focus zooming function of the optical system. The bar code readers are provided with improved decoding reliability, speed and orientation freedom, with regular or high density, one or two dimensional bar codes, by using multiple beam symbol crossings, created by using one or more piezoelectric bimorph elements. In different disclosed embodiments, one or more cantilever mounted piezoelectric bimorph elements support a scanning mirror, or a focusing lens, or a laser diode, or a laser diode and limiting aperture, for movement at the free ends of the bimorph elements to produce a scanning of the bar code reader optical system. Several disclosed embodiments of the subject invention provide a beam deflector for a bar code reader optical system having a variable focus zoom lens system in which one or more cantilever mounted piezoelectric bimorph elements control the variable focus zoom lens system. 1
摘要:
Two-dimensional information such as a written signature can be captured and subsequently reconstructed by using an electro-optical scanner. A multi-row preamble code and a multi-row postamble code flank the signature, and each code has a row identifier for identifying which row is being scanned by a scan line emitted by the scanner, as well as start/stop data for identifying when each scan line traverses the boundaries of a space containing the signature.
摘要:
A PIN GaAlAs diode structure is provided with parameters for index guiding of light in a single mode. The index of refraction of the central layer I (which in practice may be lightly doped .pi. or .nu.) is greater than the p- and n-layers to create a slab waveguide in the transverse direction. Stripe contacts define separate waveguide channels that are separated electrically and optically by implanting protons or etching grooves between the stripe contacts in the upper layer. Separate reverse biasing voltages may be applied to the stripe contacts for modulation of the light in proportions to the voltage, either with absorption modulation, if the light wavelength is within about 500.ANG. of the bandgap of the .pi.-material, or phase-delay modulation, if the wavelength is separated from the bandgap of the .pi.-material by at least 900.ANG..