Classifications

• • G—PHYSICS
  • G06—COMPUTING OR CALCULATING; COUNTING
  • G06K—GRAPHICAL DATA READING; PRESENTATION OF DATA; RECORD CARRIERS; HANDLING RECORD CARRIERS
  • G06K7/00—Methods or arrangements for sensing record carriers, e.g. for reading patterns
  • G06K7/10—Methods or arrangements for sensing record carriers, e.g. for reading patterns by electromagnetic radiation, e.g. optical sensing; by corpuscular radiation
  • G06K7/10544—Methods or arrangements for sensing record carriers, e.g. for reading patterns by electromagnetic radiation, e.g. optical sensing; by corpuscular radiation by scanning of the records by radiation in the optical part of the electromagnetic spectrum
• • G—PHYSICS
  • G06—COMPUTING OR CALCULATING; COUNTING
  • G06K—GRAPHICAL DATA READING; PRESENTATION OF DATA; RECORD CARRIERS; HANDLING RECORD CARRIERS
  • G06K2207/00—Other aspects
  • G06K2207/1011—Aiming

Definitions

• the present invention generally relates to image capture systems and methods
• Optical codes are patterns made up of image areas having different light-
• barcode is sometimes used to describe certain kinds of optical codes.
• optical properties and patterns of optical codes are selected to distinguish them in
• optical code readers of
• optical code can be used as a rapid, generalized means of data
• the optical code reader is connected to a portable data processing device or a data
• the optical code reader includes a handheld
• the barcode is a pattern of variable- width rectangular bars
• the bars and spaces have different light-reflecting
• One example of a one-dimensional barcode is the UPC/EAN code used to identify, for example, product inventory.
• PDF417 barcode A description of PDF417 barcode and techniques for decoding it is the PDF417 barcode.
• MaxiCode consists of a central finder pattern or bull's eye center and a grid of hexagons
• the system then decodes the waveform to extract information from the barcode.
• Barcodes can also be read by employing imaging devices, also deployed in hand ⁇
• an image sensor may be employed which has a one- or two-
• Such an image sensor may be a two-dimensional or area charge - J - coupled device (CCD) and associated circuits for producing electronic signals corresponding
• the imaging device is a passive unit
• a diffractive element a diffractive element, a holographic element, or a Fresnel element, which generate a light
• T mn ⁇ /sin ( ⁇ max ), where ⁇ is the wavelength of the light.
• ⁇ raax 20
• electro-optical readers especially imaging readers operative for reading two-dimensional
• Still another object of the present invention is to enable the optical component
• optical component having a plurality of refractive structures spaced apart along
• each structure having a structural dimension T as measured along the direction;
• a light source such as a laser diode, for generating a visible, collimated
• T provides independence of the aiming pattern from the radiation distribution of the laser
• the dimension T is on the order of millimeters, not microns, and hence, lends
• the optical component to be fabricated by low cost manufacturing processes such as molding
• the laser diode generates a diverging laser beam
• an aperture stop is located in the path of the diverging beam for forming a predetermined
• a portion of the optical component is operative for optically
• Each refractive structure is formed with a desired surface profile to obtain a
• the refractive structures may have curved surfaces for
• the aiming light pattern as a single aiming line with a substantially uniform light
• Each curved surface may be convex or concave.
• the refractive structures may have planar surfaces and curved surfaces for generating the aiming light pattern as a single aiming line having a line intensity
• At least one of the refractive structures has one of the planar surfaces flanked by two of the curved surfaces.
• the refractive structures may have a plurality of planar surfaces for generating a plurality of aiming spots, and preferably, at least one of the refractive
• structures has one of the planar surfaces flanked by two more of the planar surfaces inclined relative to the one planar surface.
• the central row of refractive structures has curved surfaces for generating an aiming line.
• the side rows of refractive structures have curved surfaces for together generating another aiming line.
• Still another example is embodied in the refractive structures being arranged in
• beam cross-section of the laser diode is an ellipse having a major axis extending diagonally
• Both rows of refractive structures have curved surfaces for together generating
• the optical component has a central elongated planar face
• the refractive structures are arranged in two side rows at opposite sides of the central face and are inclined at opposite
• Each refractive structure of one of the side rows has a pair of planar surfaces for generating a pair of end aiming spots spaced in one direction away from the central spot.
• Each refractive structure of the other of the side rows has a pair of planar surfaces for generating another pair of end aiming spots spaced in an opposite
• the resulting aiming pattern comprises five aiming spots.
• the refractive structures are periodically spaced
• each refractive structure has a parabolic curvature.
• the optical component is constituted of a molded or machined material having an index of refraction on the order of 1.5, such as glass or plastic.
• At least one of the refractive structures is a channel or a
• hump extending along a transverse direction perpendicular to the direction.
• FIG. 1 is a diagrammatic perspective view of some components of an imaging
• FIG. 2 is a diagrammatic view of an aiming pattern generator for use with the
• FIG. 1 in accordance with one embodiment of this invention
• FIG. 3 is an end view of the optical component of FIG. 2 with a laser beam
• FIG. 4 is an enlarged side view of the surface profile of the component of FIG.
• FIG. 5 is a graph to explain ray directions exiting the component having the
• FIG. 6 is a view analogous to FIG. 4, but of another embodiment of this
• FIG. 7 is a representation of a single line aiming pattern generated by the
• FIG. 8 is a view analogous to FIG. 4, but of another embodiment of this
• FIG. 9 is a graph to explain ray directions exiting the component having the
• FIG. 10 is a representation of an aiming pattern comprising a single line and a
• FIG. 11 is a representative enlarged side view of another surface profile of the
• FIG. 12 is a graph to explain ray directions exiting the component having the
• FIG. 13 is a representation of an aiming pattern comprising three aiming spots
• FIG. 14 is a rear perspective view of an optical component in accordance with
• FIG. 15 is an end view of the component of FIG. 14 with a laser beam
• FIG. 16 is a representation of an aiming pattern comprising two intersecting
• FIG. 17 is a front perspective view of an optical component in accordance with
• FIG. 18 is an end view of the component of FIG. 17 with a laser beam
• FIG. 19 is a representation of an aiming pattern comprising two intersecting
• FIG. 20 is a view analogous to FIG. 18, but of still another embodiment of this
• FIG. 21 is an enlarged, broken-away view of the surface profile of the
• FIG. 22 is a representation of an aiming pattern comprising five spaced-apart
• FIG. 23 is a perspective view of an additional embodiment of this invention.
• FIG. 24 is a top plan view of FIG. 23.
• FIG. 25 is a representation of an aiming pattern comprising two intersecting
• FIG. 1 illustrates an image sensor array 12
• a field of view 14 is imaged by the image sensor array 12. More
• lens 16 which focuses the light onto the surface of the array.
• each having one or more photosensors produce electronic signals corresponding to a two-
• an aiming system is provided.
• the system includes a laser diode 18, an optical component 20, better seen in FIGS. 2-3, and an aperture stop 22.
• the laser diode 18 generates a laser beam having a wavelength ⁇ .
• the beam is optically modified to have a predetermined cross-section.
• the rear potion is configured to optically modify the beam passing
• the rear portion of the component 20 is formed with a
• plurality of refractive structures for example, elongated concave grooves 24, 26, 28, arranged
• Each structure has a structural dimension T as
• the cross-section of the beam has a beam dimension D which, as shown, is
• the dimension T is chosen to be much greater than ⁇ divided
• T min the structural dimension
• each structure has a curved surface profile, preferably a
• FIG. 5 is a corresponding graph depicting the local
• the light projected from the component forms a single visible aiming
• dimension T is chosen to be about 0.5 mm, and if the index of refraction is about 1.5, then an
• FIG. 8 is analogous to FIG. 4, except that each refractive structure is configured
• the tan a is plotted
• FIG. 11 is analogous to FIG. 8, except the profile of only one refractive
• FIG. 12 is a plot of tan a, and it will
• FIG. 13 Central spot 46 marks the center of the field of view, and end spots 48 , 50 mark the
• FIG. 14 depicts another embodiment of the optical component as seen from a
• the front portion is configured as a convex lens 52, and a plurality of groups
• One of the groups is arranged along a central row 58, and the structures of the central row 58 are configured with the
• top and bottom rows are each configured with the sinusoidal profile
• FIG. 6 to project an aiming line 66 which crosses the line 60 to form the cross-hairs pattern
• the optical component has an outer diameter of 2.5 mm
• the central row can occupy a zone of about 0.7 mm, and the top and bottom zones can
• junction is taken into account, and corresponds to a beam dimension D of about 0.4 to 0.7 mm
• the structural dimension T amounts to about 0.4 mm.
• each of the top and bottom rows typically amounts to about 0.5 mm.
• FIG. 17 depicts another embodiment of the optical component 20 similar to that
• One of the groups extends along a row 68 and occupies about
• FIG. 20 in which the rear portion is subdivided into three zones, namely a central zone
• the central spot would be elongated. Light passing through one of the end zones is projected
• planar surfaces 80, 82 onto the indicia as a pair of end aiming spots 88, 90, whil&light
• indicia as another pair of end aiming spots 92, 94, thereby forming the aiming pattern of FIG.
• each end zone is given an 18° surface tilt, so that 18°
• FIGS. 23-24 Yet another embodiment of the optical component is depicted in FIGS. 23-24.
• FIGS. 23-24 has a central zone
• a pair of side zones 106, 108 having a plurality of refractive structures 114 operative for producing the left half and the right half of the horizontal line 98 in the
• optical component has been described as having an integral front
• collimation can be performed by a discrete optical element remote
• the optical element preferably has built-in correction for
• Z is the surface sag
• a is a spherical aberration coefficient
• R is the radial lateral coordinate
• lateral translation of the beam spot does not change the
• aiming patterns is preferably uniform, but this is not necessarily the case. It is sometimes
• the intensity distribution be non-uniform. For example, if more intensity toward
• curvature for each structure rather than a parabolic curvature, would be beneficial.

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• Physics & Mathematics (AREA)
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• Electromagnetism (AREA)
• Artificial Intelligence (AREA)
• Toxicology (AREA)
• General Health & Medical Sciences (AREA)
• Health & Medical Sciences (AREA)
• Computer Vision & Pattern Recognition (AREA)
• General Physics & Mathematics (AREA)
• Theoretical Computer Science (AREA)
• Length Measuring Devices By Optical Means (AREA)
• Mechanical Optical Scanning Systems (AREA)
• Semiconductor Lasers (AREA)

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Citations (1)

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• 2004
  • 2004-06-29 US US10/879,333 patent/US7182260B2/en not_active Expired - Lifetime
• 2005
  • 2005-06-28 EP EP05767731A patent/EP1776653B1/en not_active Expired - Lifetime
  • 2005-06-28 CN CNB2005800214989A patent/CN100470577C/zh not_active Expired - Lifetime
  • 2005-06-28 JP JP2007519405A patent/JP4515502B2/ja not_active Expired - Lifetime
  • 2005-06-28 WO PCT/US2005/023153 patent/WO2006004858A2/en not_active Ceased

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