LASER SCANNING SYSTEM EMPLOYING AN OPTICS MODULE CAPABLE OF FORMING A LASER BEAM HAVING AN EXTENDED DEPTH OF FOCUS (DOF) OVER THE LASER SCANNING FIELD
First Claim
1. A system for reading symbols, comprising:
- a scanning module for scanning a laser beam across a scanning field having a near-field portion and a far-field portion, the scanning module comprising;
a far-field source;
a far-field optics module having an optical axis;
a drive module for driving the far-field source and the far-field optics module to produce a far-field laser beam; and
a scanning mechanism for scanning the far-field laser beam across the scanning field;
a photo-detector for detecting the intensity of light reflected from the scanning field and generating a signal corresponding to the detected light intensity;
a processor for decoding the generated signal to generate data representative of a symbol in the scanning field;
wherein the far-field optics module comprises;
an aperture stop for shaping the far-field laser beam to a predetermined diameter;
a collimating lens for collimating the far-field laser beam shaped by the aperture stop;
an apodization element having a first optical surface and a second optical surface; and
a negative bi-prism, after the apodization element along the optical axis, for transforming the energy distribution of the far-field laser beam to substantially a single beam spot in the far-field portion of the scanning field.
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Accused Products
Abstract
A laser scanning system having a laser scanning field, and a laser beam optics module with an optical axis and including: an aperture stop disposed after a laser source for shaping the laser beam to a predetermined beam diameter; a collimating lens for collimating the laser beam produced from the aperture stop; an apodization element having a first and second optical surfaces for extending the depth of focus of the laser beam from the collimating lens; and a negative bi-prism, disposed after the apodization element, along the optical axis, to transform the energy distribution of the laser beam and cause the laser beam to converge to substantially a single beam spot along the far-field portion of the laser scanning field, and extend the depth of focus of the laser beam along the far-field portion of the laser scanning field.
347 Citations
23 Claims
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1. A system for reading symbols, comprising:
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a scanning module for scanning a laser beam across a scanning field having a near-field portion and a far-field portion, the scanning module comprising; a far-field source; a far-field optics module having an optical axis; a drive module for driving the far-field source and the far-field optics module to produce a far-field laser beam; and a scanning mechanism for scanning the far-field laser beam across the scanning field; a photo-detector for detecting the intensity of light reflected from the scanning field and generating a signal corresponding to the detected light intensity; a processor for decoding the generated signal to generate data representative of a symbol in the scanning field; wherein the far-field optics module comprises; an aperture stop for shaping the far-field laser beam to a predetermined diameter; a collimating lens for collimating the far-field laser beam shaped by the aperture stop; an apodization element having a first optical surface and a second optical surface; and a negative bi-prism, after the apodization element along the optical axis, for transforming the energy distribution of the far-field laser beam to substantially a single beam spot in the far-field portion of the scanning field. - View Dependent Claims (2, 3, 4, 5)
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6. A system for reading symbols, comprising:
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a scanning module for scanning a laser beam across a scanning field having a near-field portion and a far-field portion, the scanning module comprising; a far-field source; a far-field optics module having an optical axis; a drive module for driving the far-field source and the far-field optics module to produce a far-field laser beam; and a scanning mechanism for scanning the far-field laser beam across the scanning field; wherein the far-field optics module comprises; an aperture stop for shaping the far-field laser beam to a predetermined diameter; a collimating lens for collimating the far-field laser beam shaped by the aperture stop; an apodization element having a first optical surface and a second optical surface; and a negative bi-prism, after the apodization element along the optical axis, for transforming the energy distribution of the far-field laser beam to substantially a single beam spot in the far-field portion of the scanning field. - View Dependent Claims (7, 8, 9, 10, 11)
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12. An optics module having an optical axis, the optics module comprising:
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an aperture stop for shaping a laser beam to a predetermined diameter, the laser beam having been produced by a source; a collimating lens for collimating the laser beam shaped by the aperture stop; an apodization element having a first optical surface and a second optical surface; and a negative bi-prism, after the apodization element along the optical axis, for transforming the energy distribution of the laser beam to substantially a single beam spot in a far-field portion of a scanning field across which a scanning mechanism scans the laser beam. - View Dependent Claims (13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23)
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Specification