Optical scanners with scan motion damping and orientation of astigmantic laser generator to optimize reading of two-dimensionally coded indicia
First Claim
1. An optical scanning system for reading optically encoded indicia having portions of differing light reflectivity, said system comprising:
- emitting and optics means for emitting a beam of light and optically directing the beam of light toward the optically encoded indicia;
means for receiving light reflected back from the optically encoded indicia and producing electrical signals corresponding to the differing light reflectivity of the optically encoded indicia;
a first flexible strip, one end of which is fixed, and an opposite end of which is free to move upon flexing of said first flexible strip;
means for producing a reciprocal flexing motion of the first flexible strip such that the free end of the first flexible strip reciprocates;
means for mounting a component of the emitting and optics means for reciprocal movement with the free end of the first flexible strip, such that the light beam scans across the optically encoded indicia during the reciprocal flexing motion of the first flexible strip;
a second flexible strip having a fixed end and a free end; and
engagement means for engaging a portion of the second flexible strip at least at or near the free end of the second flexible strip during the reciprocal flexing motion of the first flexible strip, such that said second flexible strip provides support for said first flexible strip or frictionally dampens the reciprocal flexing motion of the first flexible strip.
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Accused Products
Abstract
In an optical scanner, a component for producing a beam scanning motion is mounted on a first flexible strip or planar spring. One or more additional flexible strips, adjacent the first flexible strip, provide additional support to prevent droop by the first flexible strip under the weight of the scanning component. The additional flexible strips also frictionally damp the low frequency motion of the first flexible strip to prevent interference with scanning due to vibration induced from movement of the scanner by an operator. In two-dimensional scanners, where the component moves in two orthogonal directions at two different speeds, the additional strip type frictional damping is applied to the planar spring which provides the necessary flexible support for motion in the slow speed scanning direction. Also, two-dimensional scanners conforming to the present invention use a gain-guided visible laser diode oriented in a particular manner so that the astigmatism of the laser beam extends the working range by compensating for decreasing fast direction scan line density at points farther away from the scanner.
120 Citations
33 Claims
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1. An optical scanning system for reading optically encoded indicia having portions of differing light reflectivity, said system comprising:
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emitting and optics means for emitting a beam of light and optically directing the beam of light toward the optically encoded indicia; means for receiving light reflected back from the optically encoded indicia and producing electrical signals corresponding to the differing light reflectivity of the optically encoded indicia; a first flexible strip, one end of which is fixed, and an opposite end of which is free to move upon flexing of said first flexible strip; means for producing a reciprocal flexing motion of the first flexible strip such that the free end of the first flexible strip reciprocates; means for mounting a component of the emitting and optics means for reciprocal movement with the free end of the first flexible strip, such that the light beam scans across the optically encoded indicia during the reciprocal flexing motion of the first flexible strip; a second flexible strip having a fixed end and a free end; and engagement means for engaging a portion of the second flexible strip at least at or near the free end of the second flexible strip during the reciprocal flexing motion of the first flexible strip, such that said second flexible strip provides support for said first flexible strip or frictionally dampens the reciprocal flexing motion of the first flexible strip. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18)
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19. A two-dimensional optical scanning system for reading indicia optically encoded in two dimensions, said indicia having portions of differing light reflectivity, said system comprising:
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emitting and optics means for emitting a beam of light and optically directing the beam of light toward the optically encoded indicia; first support means for mounting a component of the emitting and optics means for oscillating movement in a first direction at a first oscillating frequency; second support means for mounting the first support means for oscillating movement in a second direction at a second oscillating frequency, said second direction being substantially orthogonal to said first direction, and said second frequency being less than said first frequency, wherein said second support means comprises; (i) a first flexible strip one end of which is fixed and an opposite end of which is free to reciprocate in the second direction upon reciprocal flexing of said first flexible strip, (i) means for supporting the first support means for reciprocal movement together with the reciprocal movement of the free end of the first flexible strip in the second direction, (iii) a second flexible strip having a fixed end and a free end, and (iv) engagement means for engaging a portion of the second flexible strip at least at or near the free end of the second flexible strip during the reciprocal flexing motion of the first flexible strip, such that the second flexible strip provides support for the first flexible strip or frictionally dampens the reciprocal flexing motion of the first flexible strip; read-drive means for simultaneously producing reciprocal motion of the optical component mounted on the first reciprocal support means in the first direction and reciprocal motion of the free end of the first flexible member in the second direction, such that the beam of light implements a two-dimensional scanning pattern across a surface on which said optically encoded indicia appears; and means for receiving light reflected back from the surface and producing electrical signals corresponding to the differing light reflectivity of the optically encoded indicia. - View Dependent Claims (20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33)
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Specification