Portable laser diode scanning head
First Claim
Patent Images
1. In a laser scanning system for reading symbols, a laser scanning head comprising:
- (a) means including an actuatable laser light source mounted in the head and operative, when actuated, for generating an incident laser beam;
(b) optic means mounted in the head for optically forming and directing said incident laser beam along a first optical path toward a reference plane located exteriorly of the head, and to a symbol located in a working distance range in the vicinity of the reference plane, thereby reflecting off the symbol reflected laser light, at least a returning portion of which travels along a second optical path away from the symbol back toward the head,said optic means including a focusing lens and an aperture stop located in the first optical path in the immediate vicinity of the focusing means between the laser light source and the symbol and operative for focusing the incident laser beam to have a beam cross-section of a predetermined size within the working distance range, said aperture stop having a cross-section which is smaller than the beam cross-section at the aperture stop to permit a portion of the incident light beam to pass through the aperture stop en route to the symbol, said cross-section of the aperture stop directly determining said predetermined size of the beam cross-section, said aperture stop being bounded by a blocking wall for obstructing the remaining portion of the incident light beam from passing through the aperture stop en route to the symbol;
(c) scanning means mounted in the head for scanning the symbol in a scan across the symbol, said returning portion of said reflected laser light having a variable intensity over the scan;
(d) sensor means mounted in the head for detecting the variable intensity of said returning portion of said reflected laser light over a field of view, and for generating an electrical analog signal indicative of the detected variable light intensity;
(e) said scanning means being operative for scanning at least one of said incident laser beam and the field of view;
(f) signal processing means mounted in the head for processing the analog electrical signal, and for generating a processed signal indicative of the symbol; and
(g) manually-actuatable trigger means on the head and operatively connected to, and operative for actuating, the laser beam generating means, scanning means, sensor means and signal processing means to initiate a reading of the symbol upon manual actuation of the trigger means by the user, said trigger means being actuatable for each symbol to be read, each symbol in its respective turn.
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Reexamination
Accused Products
Abstract
A portable laser diode scanning head, aimable at each symbol to be read, emits and receives non-readily-visible laser light, and is equipped with a trigger-actuated aiming light arrangement for visually locating and tracking each symbol. A compact laser diode optical train and an optical folded path assembly, as well as an interchangeable component design and an integral window construction for the head also are disclosed.
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Citations
20 Claims
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1. In a laser scanning system for reading symbols, a laser scanning head comprising:
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(a) means including an actuatable laser light source mounted in the head and operative, when actuated, for generating an incident laser beam; (b) optic means mounted in the head for optically forming and directing said incident laser beam along a first optical path toward a reference plane located exteriorly of the head, and to a symbol located in a working distance range in the vicinity of the reference plane, thereby reflecting off the symbol reflected laser light, at least a returning portion of which travels along a second optical path away from the symbol back toward the head, said optic means including a focusing lens and an aperture stop located in the first optical path in the immediate vicinity of the focusing means between the laser light source and the symbol and operative for focusing the incident laser beam to have a beam cross-section of a predetermined size within the working distance range, said aperture stop having a cross-section which is smaller than the beam cross-section at the aperture stop to permit a portion of the incident light beam to pass through the aperture stop en route to the symbol, said cross-section of the aperture stop directly determining said predetermined size of the beam cross-section, said aperture stop being bounded by a blocking wall for obstructing the remaining portion of the incident light beam from passing through the aperture stop en route to the symbol; (c) scanning means mounted in the head for scanning the symbol in a scan across the symbol, said returning portion of said reflected laser light having a variable intensity over the scan; (d) sensor means mounted in the head for detecting the variable intensity of said returning portion of said reflected laser light over a field of view, and for generating an electrical analog signal indicative of the detected variable light intensity; (e) said scanning means being operative for scanning at least one of said incident laser beam and the field of view; (f) signal processing means mounted in the head for processing the analog electrical signal, and for generating a processed signal indicative of the symbol; and (g) manually-actuatable trigger means on the head and operatively connected to, and operative for actuating, the laser beam generating means, scanning means, sensor means and signal processing means to initiate a reading of the symbol upon manual actuation of the trigger means by the user, said trigger means being actuatable for each symbol to be read, each symbol in its respective turn. - View Dependent Claims (2, 3)
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4. An optical system for distinguishing different light-reflective indicia portions from each other, comprising:
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(a) means including a laser light source for generating a wide-angle laser beam; and (b) optic means for optically forming and directing the laser beam along an optical path to different light-reflective indicia portions for reflection therefrom, said optic means including focusing means and an aperture stop located in the optical path in the immediate vicinity of the focusing means between the laser light source and the light-reflective indicia portions for focusing the laser beam to have a beam cross-section of a predetermined size within a working distance range, said aperture stop having a cross-section which is smaller than the beam cross-section at the aperture stop to permit a part of the beam to pass through the aperture stop en route to the indicia portions, said cross section of the aperture stop directly determining said pre-determined size of the beam cross-section, said aperture stop being bounded by a blocking wall for obstructing the remaining part of the beam from passing through the aperture stop en route to the indicia portions. - View Dependent Claims (5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15)
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16. An optical system for distinguishing different light-reflective indicia portions from each other, comprising:
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(a) means including a laser light source for generating a laser beam; and (b) optical means for directing the laser beam along an optical path to light-reflective indicia portions for reflection therefrom, said optical means including an aperture stop located in the optical path between the laser light source and the light-reflective indicia portions for modifying the laser beam to have a beam cross-section of a predetermined size within a working distance range, said aperture stop having a substantially rectangular cross-section which is smaller than the beam cross-section at the aperture stop and a numerical aperture value below 0.05 to permit a part of the beam to pass through the aperture stop and to directly determine said predetermined size of the beam cross-section, said aperture stop being bounded by a blocking wall for obstructing the remaining part of the beam from passing through the aperture stop en route to the indicia portions. - View Dependent Claims (17, 18, 19, 20)
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Specification