Variable focus optical system for data reading
First Claim
1. An optical system for data reading, comprising:
- a light source generating an optical beam along an outgoing optical path toward an object to be read;
a focusing system positioned in the outgoing optical path for focusing the optical beam to a given waist;
means for adjusting position of the waist of the optical beam comprising an aperture device positioned in the outgoing optical path, the aperture device forming an opening which is offset from a center of the outgoing beam.
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Accused Products
Abstract
An optical system and method for data reading in which a light source generates an optical beam directed toward an object to be read and a variable aperture mechanism positioned in the outgoing light path establishes at least two separate focal planes. The variable aperture device may comprise a variable aperture system in which the size of the aperture is selectively varied about a range within the diffractive limit of the light beam. A preferred aperture mechanism is a liquid crystal aperture with one or more aperture regions which are selectively or consecutively activated. The optical system therefore establishes two or more separate waist locations from a single light source resulting in greater depth of field or multiple depths of field.
98 Citations
39 Claims
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1. An optical system for data reading, comprising:
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a light source generating an optical beam along an outgoing optical path toward an object to be read; a focusing system positioned in the outgoing optical path for focusing the optical beam to a given waist; means for adjusting position of the waist of the optical beam comprising an aperture device positioned in the outgoing optical path, the aperture device forming an opening which is offset from a center of the outgoing beam. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28)
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29. A laser scanner for bar code reading, comprising:
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a laser diode generating a laser beam along an outgoing optical path; focusing lens positioned in the outgoing optical path for focusing the laser beam to a waist at a given location; an aperture device forming an aperture opening of a given width for adjusting location of the waist, the aperture opening positioned in the outgoing optical path at a position downstream from one focal length upstream of the focusing lens, wherein the aperture opening is non-symmetrically positioned to one side of a center of the outgoing optical beam.
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30. In a data reader having a laser diode module producing a laser beam along an outgoing optical path and an aperture mechanism with an aperture opening disposed in the optical path, a method for assembling the data reader comprising the steps of:
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determining to which side from a center of the outgoing optical path that locating the aperture opening offset from the center produces superior beam profile; and arranging the aperture mechanism and the laser diode module such that the aperture opening is non-symmetrically positioned to that side of the center of the outgoing optical path. - View Dependent Claims (31, 32)
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33. In a data reader having a laser diode module producing a laser beam along an outgoing optical path and an aperture mechanism with an aperture opening disposed in the optical path, a method for assembling the data reader comprising the steps of:
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(a) testing the laser diode module to determine to which side of the laser beam locating the aperture opening offset to produces a superior beam profile; (b) aligning the laser diode module and the aperture mechanism on the basis of the result of the testing in step (a). - View Dependent Claims (34, 35)
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36. An optical system for data reading, comprising:
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a light source generating an optical beam along an outgoing optical path; a focusing system positioned in the outgoing optical path for focusing the optical beam to a waist at a given location; an aperture device positioned in the outgoing optical path, the aperture device forming an aperture opening having side edges which are jagged in shape. - View Dependent Claims (37, 38, 39)
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Specification