Optical scanner for omni-directional scanning of code symbols within a scanning volume

• US 6,460,767 B1
• Filed: 05/29/1997
• Issued: 10/08/2002
• Est. Priority Date: 09/10/1990
• Status: Expired due to Fees

• Current Assignee: Metrologic Instruments Incorporated (Honeywell International Inc.)
• Original Assignee: Metrologic Instruments Incorporated (Honeywell International Inc.)
• Inventors: Naylor, Charles A., Knowles, Carl Harry, Bubnoski, David Paul
• Primary Examiner(s): Frech, Karl D.
• Application Number:
  US08/865,257
• Time in Patent Office: 1,958 Days
• Field of Search: 235/462.14, 235/462.32, 235/462.33, 235/462.36, 235/462.37, 235/462.38, 235/462.39
• US Class Current: 235/462.37
• CPC Class Codes: A47F 9/046 Arrangement of recording means in or on check-out counters record carriers or readers per se G06K
• CPC Class Codes: A47F 9/047 for recording self-service articles without cashier or assistant
• CPC Class Codes: G02B 26/10 Scanning systems
• CPC Class Codes: G02B 26/106 having diffraction gratings as scanning elements, e.g. holographic scanners holographic optical elements G02B5/32, holography G03H
• CPC Class Codes: G06K 17/0022 arrangements or provisions for transferring data to distant stations, e.g. from a sensing device "transfer between computer elements G06F13/00 "; data-transmission H04L
• CPC Class Codes: G06K 7/10 by electromagnetic radiation, e.g. optical sensing; by corpuscular radiation
• CPC Class Codes: G06K 7/10564 Light sources
• CPC Class Codes: G06K 7/10584 Source control
• CPC Class Codes: G06K 7/10594 Beam path
• CPC Class Codes: G06K 7/10603 Basic scanning using moving elements
• CPC Class Codes: G06K 7/10663 using hologram
• CPC Class Codes: G06K 7/10673 Parallel lines
• CPC Class Codes: G06K 7/10693 for omnidirectional scanning
• CPC Class Codes: G06K 7/10702 Particularities of propagating elements, e.g. lenses, mirrors G06K7/10831 takes precedence
• CPC Class Codes: G06K 7/10792 Special measures in relation to the object to be scanned
• CPC Class Codes: G06K 7/10801 Multidistance reading
• CPC Class Codes: G06K 7/10811 Focalisation
• CPC Class Codes: G06K 7/10851 Circuits for pulse shaping, amplifying, eliminating noise signals, checking the function of the sensing device basic electronic circuitry H03
• CPC Class Codes: G06K 7/10861 sensing of data fields affixed to objects or articles, e.g. coded labels postal sorting B07C3/14, conveying articles B65G47/48
• CPC Class Codes: G06K 7/10871 randomly oriented data-fields, code-marks therefore, e.g. concentric circles-code
• CPC Class Codes: G06K 7/10881 : constructional details of hand-held scanners
• CPC Class Codes: G06K 7/10891 : the scanner to be worn on a finger or on a wrist
• CPC Class Codes: G06K 7/109 : adaptations to make the hand-held scanner useable as a fixed scanner
• CPC Class Codes: G06K 7/14 : using light without selection of wavelength, e.g. sensing reflected white light G06K7/10831 - G06K7/1097 take precedence
• CPC Class Codes: G07G 1/0045 : with a code reader for reading of an identifying code of the article to be registered, e.g. barcode reader or radio-frequency identity [RFID] reader

Abstract

A bar code scanner for stationary disposition at a counter to projecting a scanning pattern comprising first, second, third, fourth and fifth groups of parallel scan lines within a relatively narrow, yet diverging, volume, e.g., pyramid, cone, etc., centered about a projection axis. The scanner includes a compact housing mounted on an adjustable base. The housing includes a window, five stationary mirrors, a laser diode, a rotating reflective polygon for sweeping the laser beam from the diode across the mirrors and out a window so that the projection axis is substantially but not precisely perpendicular to the window. The scanner also includes a fixed curved collecting mirror and a concentrating lens to focus light which is reflected off of a bar code to a photodetector. One mirror extends along an axis parallel to the transverse axis to produce the first group of scan lines. The second and third mirrors are disposed opposite each other close to and laterally of the polygon and extending along respective axes at a small acute angle, e.g., 8 degrees, to the longitudinal axis to produce respective ones of the second and third group of scan lines. The fourth and fifth mirrors are disposed between the second and third reflecting mirrors, respectively, and each extends along a respective axis at a substantial acute angle, e.g., 48 degrees, to the longitudinal axis to produce respective ones of the fourth and fifth group of scan lines.

Claims

1. A projection laser scanner having a laser beam and a light transmissive window and CHARACTERIZED BY:

(a) a rotating element comprising a first plurality of optically reflective surfaces;

(b) a stationary array including a second plurality of optically reflective surfaces;

(c) a control mechanism for utilizing the laser beam, the rotating element, and the stationary array so as to generate a plurality of scan line groups, each group including a plurality of substantially parallel scan lines, and wherein the scan lines are propagated out through the light transmissive window such that two or more scan line groups intersect at least once within a defined scan volume of approximately columnar and/or conical extent, extending from substantially adjacent to the light transmissive window out to a distance of at least about six inches, so as to provide a substantially omnidirectional scanning pattern within the defined scan volume, wherein a bar code symbol situated within the defined scan volume is scanned omnidirectionally, and a bar code symbol situated substantially exterior to said defined scan volume is not scanned;

(d) a scan data processing mechanism for decoding bar code symbols situated within the defined scan volume and producing data representative of such bar code symbols;

wherein the laser beam is generated by a laser diode;

and wherein the defined scan volume is oriented laterally above a substantially horizontal surface at a point of sale station, such that the scanning pattern is directed from the light transmissive window approximately downwards towards the horizontal surface.

2. The projection laser scanner of claim 1 further including a mechanical support mechanism for positioning the projection laser scanner in any of a plurality of positions relative to the horizontal surface so as to permit selection of any of a plurality of orientations of the defined scanning volume relative to the horizontal surface.

3. The projection laser scanner of claim 1 wherein a photodetecting device is used to receive light reflected from one or more bar code symbols situated within the defined scan volume.

4. An optical scanner for producing a scanning volume for scanning code symbols presented therein, the optical scanner comprising:

(a) a housing having an optically transmissive window through which optical energy can exit the housing, travel towards an object bearing a bar code symbol and reflect therefrom, and at least a portion of the reflected optical energy travel back through the optically transmissive window and enter the housing;

the housing having a central reference axis which does not intersect the optically transmissive window;

(b) an optical energy producing mechanism situated within the housing for generating optical energy;

(c) an optical energy sweeping mechanism mounted within the housing with respect to the central reference axis for rotation about a rotational axis which intersects the central reference axis, and where the intersection of the central reference axis and the rotational axis defines a central reference plane for referencing the relative positions of optical components;

the optical energy sweeping mechanism including a plurality of rotating optically reflective surfaces each disposed at a different acute angle with respect to the rotational axis, for sequentially sweeping the optical energy about the rotational axis along a plurality of different paths;

(d) a stationary array including a plurality of stationary optically reflective surfaces mounted within the housing, such that at least two of the stationary surfaces are substantially symmetrically disposed on opposite sides of the central reference plane and closely adjacent to the optical energy sweeping mechanism;

(e) an optical energy collection mechanism within the housing and including;

(i) an optical energy collection element, mounted with respect to the central reference plane, for collecting reflected optical energy from the optical energy sweeping mechanism; and

(ii) an optical receiver for receiving optical energy from the optical energy collection element at a point substantially within the central reference plane, and detecting the intensity of the received optical energy and producing an electrical signal indicative of the intensity.

5. An optical scanner for producing a scanning volume for scanning code symbols presented therein, the optical scanner comprising:

(a) a housing having an optically transmissive window through which optical energy can exit the housing, travel towards an object bearing a bar code symbol and reflect therefrom, and at least a portion of the reflected optical energy travel back through the optically transmissive window and enter the housing;

the housing having a central reference axis which does not intersect the optically transmissive window;

(b) an optical energy producing mechanism situated within the housing for generating optical energy;

(c) an optical energy sweeping mechanism mounted within the housing with respect to the central reference axis for rotation about a rotational axis which intersects the central reference axis, and where the intersection of the central reference axis and the rotational axis defines a central reference plane for referencing the relative positions of optical components;

the optical energy sweeping mechanism including a plurality of rotating optically reflective surfaces each disposed at a different acute angle with respect to the rotational axis, for sequentially sweeping the optical energy about the rotational axis along a plurality of different paths;

(d) a stationary array including a plurality of stationary optically reflective surfaces mounted within the housing, such that at least two of the stationary surfaces are substantially symmetrically disposed on opposite sides of the central reference plane and closely adjacent to the optical energy sweeping mechanism;

(e) an optical energy collection mechanism within the housing and including;

(i) an optical energy collection element, mounted with respect to the central reference plane, for collecting reflected optical energy from the optical energy sweeping mechanism;

(ii) an optical receiver for receiving optical energy from the optical energy collection element at a point substantially within the central reference plane, and detecting the intensity of the received optical energy and producing an electrical signal indicative of the intensity;

(f) a signal processing mechanism within the housing for processing the electrical signal and producing scan data representative of a scanned coded symbol;

(g) a control mechanism within the housing for utilizing the optical energy producing mechanism, the optical energy sweeping mechanism, and the stationary array so as to generate a plurality of optical scan line groups, each group including a plurality of substantially parallel scan lines, and wherein the scan lines are propagated out through the optically transmissive window such that two or more scan line groups intersect at least once within a defined scan volume of approximately columnar and/or conical extent, extending from substantially adjacent to the optically transmissive window out to a distance of at least about six inches, so as to provide a substantially omnidirectional scanning pattern within the defined scan volume, wherein a bar code symbol situated within the defined scan volume is scanned omnidirectionally, and a bar code symbol situated substantially exterior to said defined scan volume is not scanned.

6. An optical scanner for producing a scanning volume for scanning code symbols presented therein, the optical scanner comprising:

(a) a housing having an optically transmissive window through which optical energy can exit the housing, travel towards an object bearing a bar code symbol and reflect therefrom, and at least a portion of the reflected optical energy travel back through the optically transmissive window and enter the housing;

(b) an optical energy producing mechanism situated within the housing for generating optical energy;

(c) an optical energy sweeping mechanism mounted within the housing for rotation about a rotational axis;

the optical energy sweeping mechanism including a plurality of rotating optically reflective surfaces each disposed at a different acute angle with respect to the rotational axis, for sequentially sweeping the optical energy about the rotational axis along a plurality of different paths;

(d) a stationary array including a plurality of stationary optically reflective surfaces mounted within the housing, such that at least two of the stationary surfaces are substantially symmetrically disposed within the housing, the symmetrical disposition defining a central reference plane about which the surfaces are substantially symmetrical, and wherein the optically reflective surfaces are adjacent to the optical energy sweeping mechanism;

(e) an optical energy collection mechanism within the housing and including;

(i) an optical energy collection element, mounted with respect to the central reference plane, for collecting reflected optical energy from the optical energy sweeping mechanism;

(ii) an optical receiver for receiving optical energy from the optical energy collection element at a point substantially within the central reference plane, and detecting the intensity of the received optical energy and producing an electrical signal indicative of the intensity;

(f) a signal processing mechanism within the housing for processing the electrical signal and producing scan data representative of a scanned coded symbol;

(g) a control mechanism within the housing for utilizing the optical energy producing mechanism, the optical energy sweeping mechanism, and the stationary array so as to generate a plurality of optical scan line groups, each group including a plurality of substantially parallel scan lines, and wherein the scan lines are propagated out through the optically transmissive window such that two or more scan line groups intersect at least once within a defined scan volume of approximately columnar and/or conical extent, extending from substantially adjacent to the optically transmissive window out to a distance of at least about six inches, so as to provide a substantially omnidirectional scanning pattern within the defined scan volume, wherein a bar code symbol situated within the defined scan volume is scanned omnidirectionally, and a bar code symbol situated substantially exterior to said defined scan volume is not scanned.

7. The optical scanner of claim 6 wherein the optical energy is a laser beam generated by a laser diode.

8. The optical scanner of claim 7 wherein the defined scan volume is oriented laterally above a substantially horizontal surface at a point of sale station, such that the scanning pattern is directed from the optically transmissive window approximately downwards towards the horizontal surface.

9. The optical scanner of claim 8 further including a mechanical support mechanism for positioning the projection laser scanner in any of a plurality of positions relative to the horizontal surface so as to permit selection of any of a plurality of orientations of the defined scanning volume relative to the horizontal surface.

10. The optical scanner of claim 8 further comprising an adjustment mechanism for adjusting the position of one or more of the reflective surfaces of the stationary array relative to the counter surface so that the defined scan volume is projected approximately towards the counter surface in any of a plurality of orientations.

11. The optical scanner of claim 10, wherein the adjustment mechanism comprises a planar support structure upon which at least one of the stationary reflective surfaces of the stationary array are mounted.

12. The optical scanner of claim 7 wherein the optical receiver is a photodetecting device used to receive light reflected from one or more bar code symbols situated within the defined scan volume.

13. The optical scanner of claim 6, wherein the stationary array is comprised of at least one planar mirror.

14. The optical scanner of claim 6, wherein the housing has a height dimension of less than about 6.5 inches, a width dimension of less than about 6.5 inches, and a thickness dimension of less than about 3.0 inches.

15. The optical scanner of claim 6 wherein the optical receiver comprises a photodetector.

16. The optical scanner of claim 15, wherein the photodetector is disposed at a height above the laser beam sweeping mechanism and substantially within the central reference plane.

17. The optical scanner of claim 6, wherein the optical energy collection mechanism includes a light collecting mirror.

18. The optical scanner of claim 17, wherein the light collecting mirror is adjacent to the substantially symmetrically disposed stationary light reflective surfaces of the stationary array.

19. The optical scanner of claim 6 wherein each scan line in a first group of scan lines is substantially parallel to each other scan line in the first group of scan lines, each scan line in a second group of scan lines is substantially parallel to each other scan line in the second group of scan lines, each scan line in a third group of scan lines is substantially parallel to each other scan line in the third group of scan lines, each scan line in a fourth group of scan lines is substantially parallel to each other scan line in the fourth group of scan lines, and at least one scan line in the first group of scan lines intersects at least one scan line in the second group of scan lines.