U.S. patent number RE42,651 [Application Number 09/815,882] was granted by the patent office on 2011-08-30 for optical scanner having enhanced item side coverage.
This patent grant is currently assigned to NCR Corporation. Invention is credited to Paul O. Detwiler, Barry M. Mergenthaler, Hong Tang.
United States Patent |
RE42,651 |
Detwiler , et al. |
August 30, 2011 |
Optical scanner having enhanced item side coverage
Abstract
A dual aperture optical scanner which produces horizontal,
vertical, and diagonal scan patterns. The optical scanner includes
a housing having a substantially vertical surface containing a
first aperture and a substantially horizontal surface containing a
second aperture. A laser diode produces a laser beam. A spinner
produces first, second, and third groups of scanning beams. A
plurality of pattern mirrors reflects the first group of scanning
beams in a substantially horizontal direction through the first
aperture, the second group of scanning beams in a substantially
downward diagonal direction through the first aperture, and the
third group of scanning beams in a substantially vertical direction
through the second aperture.
Inventors: |
Detwiler; Paul O.
(Lawrenceville, GA), Mergenthaler; Barry M. (Lawrenceville,
GA), Tang; Hong (Suwanee, GA) |
Assignee: |
NCR Corporation (Duluth,
GA)
|
Family
ID: |
24195954 |
Appl.
No.: |
09/815,882 |
Filed: |
March 23, 2001 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
|
Reissue of: |
08550150 |
Oct 30, 1995 |
5684289 |
Nov 4, 1997 |
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Current U.S.
Class: |
235/462.38;
235/462.33; 235/383; 235/462.4; 235/462.36 |
Current CPC
Class: |
G06K
7/1096 (20130101); G06K 7/10693 (20130101); G06K
2007/10514 (20130101) |
Current International
Class: |
G06K
7/10 (20060101) |
Field of
Search: |
;235/462.36,462.37,462.38,462.39,462.4,383,384,462.33,454,217,218,738,379
;359/201,212,216,217,218,738,739 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
Primary Examiner: Frech; Karl D.
Attorney, Agent or Firm: Priest; Peter Martin; Paul W.
Claims
What is claimed is:
.[.1. An optical scanner comprising: a housing having a
substantially vertical surface containing a first aperture and a
substantially horizontal surface containing a second aperture; a
single laser which produces a laser beam within the housing; a
polygon spinner having mirrored facets for reflecting the laser
beam in a plurality of directions to produce a plurality of
scanning beams including a first group of scanning beams, a second
group of scanning beams, and a third group of scanning beams; and a
plurality of pattern mirrors, including a plurality of groups of
pattern mirrors, for reflecting the first group of scanning beams
through the first aperture to produce a first scan pattern
consisting of a plurality of intersecting scan lines, for
reflecting the second group of scanning beams through the first
aperture to produce a second scan pattern consisting of a plurality
of intersecting scan lines, and for reflecting the third group of
scanning beams through the second aperture to produce a third scan
pattern consisting of a plurality of intersecting scan
lines..].
.[.2. The optical scanner as recited in claim 1, further
comprising: an optical transceiver for passing the laser beam and
for collecting reflected light from the scanned article; and a
photodetector for generating signals representing the intensity of
the light reflected from an article having a bar code label to be
scanned..].
.[.3. The optical scanner as recited in claim 1, wherein the
housing comprises: a substantially horizontal surface containing
the first aperture; and a substantially vertical surface containing
the second aperture..].
.[.4. The optical scanner as recited in claim 1, wherein the laser
comprises a laser diode..].
.[.5. The optical scanner as recited in claim 1, wherein the
spinner has four planoreflective facets..].
.[.6. The optical scanner as recited in claim 5, wherein the four
facets are oriented at different angles with respect to a
predetermined reference..].
.[.7. The optical scanner as recited in claim 6, wherein the angles
of pairs of opposite facing facets have values which tend to
balance the spinner..].
.[.8. The optical scanner as recited in claim 1, wherein the
pattern mirrors are flat..].
.[.9. The optical scanner as recited in claim 1, wherein the
pattern mirrors comprise: a first group of mirrors for reflecting
the laser beam from the spinner; a second group of mirrors for
reflecting the laser beam from the first group of mirrors; and a
third group of mirrors for reflecting the laser beam from some of
the mirrors in the second group of mirrors..].
.[.10. An optical scanner comprising: a housing including a
substantially vertical surface containing a first aperture and a
substantially horizontal surface containing a second aperture; a
laser diode for producing a laser beam; an optical transceiver for
passing the laser beam and for collecting reflected light from an
article having a bar code label to be scanned; a spinner having a
plurality of sides oriented at different angles with respect to a
predetermined reference for reflecting the laser beam in a
plurality of directions to produce a plurality of scanning beams,
and for directing light from the article to the optical
transceiver; and a plurality of pattern mirror for reflecting a
first group of scanning beams in a substantially horizontal
direction through the first aperture, a second group of scanning
beams in a substantially downward diagonal direction through the
first aperture, and a third group of scanning beams in a
substantially vertical direction through the second aperture and
including a first group of mirrors for reflecting the laser beam
from the spinner, a second group of mirrors for reflecting the
laser beam from the first group of mirrors, and a third group of
mirrors for reflecting the laser beam from some of the mirrors in
the second group of mirrors; and a photodetector for generating
signals representing the intensity of the light reflected from the
article..].
.[.11. A method for scanning an article having a bar code label
with minimal article orientation comprising the steps of: (a)
generating a single laser beam; (b) providing a polygon spinner
including a plurality of mirrored facets; (c) reflecting the laser
beam from the polygon spinner at a plurality of pattern mirrors
within a scanner housing; and (d) reflecting a first group of scan
lines from the pattern mirrors through a vertical aperture within
the scanner housing to produce a first scan pattern consisting of a
plurality of intersecting scan lines, reflecting a second group of
scan lines from the pattern mirrors through said vertical aperture
within the scanner housing to produce a second scan pattern
consisting of a plurality of intersecting scan lines, and
reflecting a third group of scan lines through a horizontal
aperture within the scanner housing to produce a third scan pattern
consisting of a plurality of intersecting scan lines..].
.[.12. The method as recited in claim 11, further comprising the
step of: (e) moving the article through the scan lines..].
.[.13. The method as recited in claim 11, wherein step (c)
comprises the substep of: (1) rotating a spinner having a plurality
of mirrored facets in the path of the laser beam, each facet having
a predetermined elevation angle; and (2) reflecting the laser beam
from each of the facets in turn as the spinner rotates..].
.[.14. The method as recited in claim 13, wherein the spinner has
four mirrored facets..].
.[.15. The method as recited in claim 13, wherein substep (c-1)
comprises the substep of: (A) energizing a motor coupled to the
spinner..].
.[.16. The method as recited in claim 11, wherein step (d)
comprises the substeps of: (1) reflecting the laser beam from the
spinner by a first group of the pattern mirrors; and (2) reflecting
the laser beam from the first group of the pattern mirrors to a
second group of the pattern mirrors; and (3) reflecting the laser
beam from some of the pattern mirrors in the second group to a
third group of the pattern mirrors..].
.[.17. The method as recited in claim 16 wherein substep (d)
further comprises: (3) reflecting a first group of the scan lines
through the vertical aperture in a substantially horizontal
direction through the first aperture; (4) reflecting a second group
of scanning beams in a substantially downward diagonal direction
through the first aperture; and (5) reflecting a third group of the
scan lines through the horizontal aperture in a substantially
vertical direction through the second aperture..].
.[.18. A method of scanning an item having a bar code from multiple
directions, comprising the steps of generating laser light;
providing a single multi-faceted mirrored polygon in a path of said
laser light; generating a first group of scanning beams, a second
group of scanning beams, and a third group of scanning beams by
reflecting said laser light off said mirror polygon; directing said
first group of scanning beams through a first transparent member
oriented in a first plane to scan a surface of the item from one
orthogonal direction; directing said second group of scanning beams
through the first transparent member oriented in the first plane to
scan the item from a diagonal direction; and directing said third
group of scanning beams through a second transparent member
oriented in a second plane orthogonal to said first plane to scan
the item from another orthogonal direction..].
.[.19. A method of scanning an item having a bar code from multiple
directions, comprising the steps of providing a single
multi-faceted mirror polygon in a scanner housing; impinging laser
light onto said mirror polygon; rotating said mirror polygon;
generating a first group of scanning beams, a second group of
scanning beams, and a third group of scanning beams by reflecting
said laser light off said mirror polygon as it is being rotated;
directing said first group of scanning beams through a first
transparent member oriented in a first plane to scan a surface of
the item from a first orthogonal direction; directing said second
group of scanning beams through the first transparent member
oriented in the first plane to scan the item from a diagonal
direction; and directing said third group of scanning beams through
a second transparent member oriented in a second plane at about
ninety degrees to said first plane to scan the item from another
orthogonal direction..].
.[.20. A method of scanning an item having a bar code label thereon
from multiple directions, comprising the steps of: generating laser
light; providing a single multi-faceted mirror polygon in a scanner
housing; producing a first group of scanning beams, a second group
of scanning beams, and a third group of scanning beams by
reflecting the laser light off the mirrored polygon; directing the
first, second, and third groups of scanning beams to a first group
of pattern mirrors; reflecting the first, second, and third groups
of scanning beams off the first group of pattern mirrors towards a
second group of pattern mirrors; reflecting the first group of
scanning beams off the second group of pattern mirrors and out a
first surface to produce a first scan pattern consisting of a
plurality of intersecting scan lines; reflecting the second and
third groups of scanning beams off the second group of pattern
mirrors towards a third group of pattern mirrors; reflecting the
second group of scanning beams off the third group of pattern
mirrors and out a second surface which is arranged orthogonally to
the first surface to produce a second scan pattern consisting of a
plurality of intersecting scan lines; and reflecting the third
group of scanning beams off the third group of pattern mirrors and
out the second surface to produce a third scan pattern consisting
of a plurality of intersecting scan lines..].
.[.21. A bar code scanning system comprising: a housing having a
first window and a second window arranged generally orthogonally to
one another; a first set of pattern mirrors positioned adjacent the
first window; a second set of pattern mirrors positioned adjacent
the second window, including first, second, and third subsets of
pattern mirrors; a laser within the housing which produces a laser
beam; a single scanning means within the housing comprising a
mirror polygon; and a motor for rotating the mirror polygon;
wherein said mirror polygon reflects a first group of scanning
beams across the first set of pattern mirrors and out the first
window, reflects a second group of scanning beams across the first
and third subsets of pattern mirrors and out the second window, and
reflects a third group of scanning beams across the second and
third subsets of pattern mirrors and out the second window..].
22. A mirror assembly for use in an optical scanner having a
substantially vertical aperture and a substantially horizontal
aperture, comprising: a first set of pattern mirrors including at
least primary and secondary mirrors, and at least one tertiary
mirror; a second set of pattern mirrors including at least primary,
secondary, and tertiary mirrors; a third set of pattern mirrors
including at least primary and secondary mirrors; wherein each of
the primary mirrors of the first set being disposed to receive an
incident light beam at an oblique angle to reflect the incident
beam onto at least one of the secondary mirrors of the first set;
wherein each of the secondary mirrors of the first set being
disposed to receive an incident light beam at an oblique angle to
reflect the incident beam onto at least one of the tertiary mirrors
of the first set; wherein the tertiary mirror of the first set
being disposed at an oblique angle with respect to an incident
light beam from at least one of the secondary mirrors of the first
set, and positioned to reflect the incident beam outwardly and
downwardly through said substantially vertical aperture; wherein
each of the primary mirrors of the second set being disposed to
receive an incident light beam at an oblique angle to reflect the
incident beam onto at least one of the secondary mirrors of the
second set; wherein each of the secondary mirrors of the second set
being disposed to receive an incident light beam at an oblique
angle to reflect the incident beam onto at least one of the
tertiary mirrors of the second set; wherein each of the tertiary
mirrors of the second set being disposed at an oblique angle with
respect to an incident light beam from at least one of the
secondary mirrors of the second set, and positioned to reflect the
incident beam through said substantially vertical aperture; wherein
each of the primary mirrors of the third set being disposed to
receive an incident light beam at an oblique angle to reflect the
incident beam onto at least one of the secondary mirrors of the
third set; wherein each of the secondary mirrors of the third set
being disposed to receive an incident light beam at an oblique
angle to reflect the incident beam through said substantially
horizontal aperture; wherein the primary mirrors of the first set
include a plurality of generally trapezoidal mirrors; wherein the
secondary mirrors of the first set operate to receive a light beam
from said generally trapezoidal mirrors; and wherein the tertiary
mirror of the first set is a generally trapezoidal mirror which
operates to receive a light beam from said secondary mirrors of the
first set.
23. A mirror assembly for use in an optical scanner having a
substantially horizontal aperture and a substantially vertical
aperture, comprising: a first set of pattern mirrors including at
least primary and secondary mirrors, and at least one tertiary
mirror; a second set of pattern mirrors including at least primary,
secondary, and tertiary mirrors; a third set of pattern mirrors
including at least primary and secondary mirrors; a source of light
beams; wherein the primary mirrors of the first set are disposed at
oblique angles with respect to an incident light beam from said
source, to reflect the light beam onto the secondary mirrors of the
first set; wherein the secondary mirrors of the first set are
disposed at oblique angles with respect to an incident light beam
from said source, to reflect the light beam onto the tertiary
mirror of the first set; wherein the tertiary mirror of the first
set is disposed at oblique angles with respect to an incident light
beam from the secondary mirrors of the first set, and positioned to
reflect light outwardly and downwardly through said substantially
vertical aperture; wherein the primary mirrors of the second set
are disposed at oblique angles with respect to an incident light
beam from said source, to reflect light onto the secondary mirrors
of the second set; wherein the secondary mirrors of the second set
are disposed at oblique angles with respect to an incident light
beam from said source, to reflect light onto the tertiary mirrors
of the second set; wherein the tertiary mirrors of the second set
are disposed at oblique angles with respect to an incident light
beam from the secondary mirrors of the second set, and positioned
to reflect light outwardly through said substantially vertical
aperture; wherein the primary mirrors of the third set are disposed
at oblique angles with respect to an incident light beam from said
source, to reflect light onto the secondary mirrors of the third
set; wherein the secondary mirrors of the third set are disposed at
oblique angles with respect to an incident light beam from the
primary mirrors of the third set, and positioned to reflect light
outwardly through said substantially horizontal aperture; wherein
the primary mirrors of the first set include a plurality of
generally trapezoidal mirrors; wherein the secondary mirrors of the
first set operate to receive a light beam from said generally
trapezoidal mirrors; and wherein the tertiary mirror of the first
set is a generally trapezoidal mirror which operates to receive a
light beam from said secondary mirrors of the first set.
24. An optical scanner for scanning the surfaces of an object by
means of light beams from a substantially vertical aperture and a
substantially horizontal aperture, comprising: a housing having
said substantially vertical and horizontal apertures; a rotating
mirror polygon positioned at a predetermined location within an
area in said housing; at least first, second, and third sets of
pattern mirrors located within the housing along the periphery of
said area; said first set of pattern mirrors being located in one
region along said periphery, and having primary and secondary
mirrors, and at least one tertiary mirror for reflecting light
beams outwardly and downwardly through said substantially vertical
aperture; said second set of pattern mirrors being located in a
similar region along said periphery, and having primary, secondary,
and tertiary mirrors for reflecting light beams outwardly through
said substantially vertical aperture; said third set of pattern
mirrors being located in a different region along said periphery,
and having primary and secondary mirrors for reflecting light beams
through said substantially horizontal aperture; wherein the primary
mirrors of the first set include a plurality of generally
trapezoidal mirrors; wherein the secondary mirrors of the first set
operate to receive a light beam from said generally trapezoidal
mirrors; and wherein the tertiary mirror of the first set is a
generally trapezoidal mirror which operates to receive a light beam
from said secondary mirrors of the first set.
25. An optical scanner as in claim 24, in which said rotating
mirror polygon produces light beams that pass radially outward
therefrom to scan the primary mirrors of the first set of pattern
mirrors, one after another, to scan the primary mirrors of the
second set of pattern mirrors, one after another, and to scan the
primary mirrors of the third set of pattern mirrors, one after
another.
26. An optical scanner as in claim 24, in which said rotating
mirror polygon reflects light beams onto the primary mirrors of
said first, second, and third sets of pattern mirrors as it
rotates.
27. An optical scanner as in claim 24, in which said rotating
mirror polygon reflects light onto the primary mirrors of said
first, second, and third sets of pattern mirrors.
28. A mirror assembly for use in an optical scanner having a
substantially vertical aperture and a substantially horizontal
aperture, comprising: a first set of pattern mirrors including at
least primary and secondary mirrors, and at least one tertiary
mirror; a second set of pattern mirrors including at least primary,
secondary, and tertiary mirrors; a third set of pattern mirrors
including at least primary and secondary mirrors; a source of
light; the primary mirrors of the first set being disposed at
oblique angles with respect to the source of light, to reflect the
source of light onto the secondary mirrors of the first set; the
secondary mirrors of the first set being disposed at oblique angles
with respect to incident light beams from the primary mirrors of
the first set, and positioned to reflect the light beams onto the
tertiary mirror of the first set; the tertiary mirror of the first
set being disposed at oblique angles with respect to incident light
beams from the secondary mirrors of the first set, and positioned
to reflect the light beams outwardly and downwardly through said
substantially vertical aperture; the primary mirrors of the second
set being disposed at oblique angles with respect to the source of
light, to reflect the source of light onto the secondary mirrors of
the second set; the secondary mirrors of the second set being
disposed at oblique angles with respect to the source of light, to
reflect the source of light onto the tertiary mirrors of the second
set; the tertiary mirrors of the second set being disposed at
oblique angles with respect to incident light beams from the
secondary mirrors of the second set, and positioned to reflect the
light beams outwardly through said substantially vertical aperture;
the primary mirrors of the third set being disposed at oblique
angles with respect to the source of light, to reflect the source
of light onto the secondary mirrors of the third set; the secondary
mirrors of the third set being disposed at oblique angles with
respect to the source of light, to reflect the source of light
beams through said substantially horizontal aperture; and the
primary mirrors of the first set including two pairs of opposite
side mirrors.
29. A mirror assembly as in claim 28, wherein the secondary mirrors
of the first set include opposite groups of three mirrors, wherein
each secondary mirror operates to receive a light beam from one of
the primary mirrors of the first set.
30. A mirror assembly as in claim 28 in which at least two of the
secondary mirrors of the first set operate to receive a light beam
from a common primary mirror of the first set.
31. An optical scanner as in claim 28, in which the source of light
includes a rotating mirrored surface that directs light onto the
primary mirrors of said first, second, and third sets of pattern
mirrors as it rotates.
32. An optical scanner as in claim 28, in which the source of light
includes a rotating polygon with mirrors on each its sides to
reflect light onto the primary mirrors of said first, second, and
third sets of pattern mirrors.
.[.33. An optical scanner comprising: a housing including a
substantially vertical surface containing a first aperture and a
substantially horizontal surface containing a second aperture;
first and second lasers for producing first and second laser beams;
an optical transceiver for passing the laser beam and for
collecting reflected light from an article having a bar code label
to be scanned; a spinner having a plurality of sides oriented at
different angles with respect to a predetermined reference for
reflecting the first and second laser beams in a plurality of
directions to produce a plurality of scanning beams, and for
directing light from the article to the optical transceiver; and a
plurality of pattern mirrors for reflecting a first group of
scanning beams in a substantially horizontal direction through the
first aperture, a second group of scanning beams in a substantially
downward diagonal direction through the first aperture, and a third
group of scanning beams in a substantially vertical direction
through the second aperture and including a first group of mirrors
for reflecting the laser beam from the spinner, a second group of
mirrors for reflecting the laser beam from the first group of
mirrors, and a third group of mirrors for reflecting the first and
second laser beams from some of the mirrors in the second group of
mirrors; and a photodetector for generating signals representing
the intensity of the light reflected from the article..].
.[.34. An optical scanner as recited in claim 33, further
comprising: control circuitry which alternately applies power to
the first and second lasers..].
.[.35. An optical scanner as recited in claim 33, wherein the first
and second lasers have different depths of field..].
.Iadd.36. The mirror assembly as in claim 28 wherein the second set
of mirrors includes three tertiary mirrors..Iaddend.
.Iadd.37. The mirror assembly as in claim 36 wherein at least two
of the tertiary mirrors of the second set of mirrors reflect light
beams downwardly through the substantially vertical
aperture..Iaddend.
.Iadd.38. The mirror assembly as in claim 28 wherein the mirror
assembly is for scanning bar codes on articles, and the light
reflected downwardly through the substantially vertical window from
the tertiary mirror of the first set scans a bar code on the top
surface of an article..Iaddend.
.Iadd.39. The mirror assembly as in claim 38 wherein the light
reflected downwardly produces beams that intersect one
another..Iaddend.
.Iadd.40. The mirror assembly as in claim 39 wherein the light
beams from the substantially vertical aperture scan the top and
customer side of the article, and the light beams from the
substantially horizontal aperture scan the bottom of the article
and its leading and trailing sides..Iaddend.
.Iadd.41. The mirror assembly as in claim 28 wherein the mirror
assembly includes at least six primary mirrors, at least five
secondary mirrors and at least four tertiary mirrors said at least
six primary mirrors reflecting light to said at least five
secondary mirrors, and said at least five secondary mirrors
reflecting light to said at least four tertiary
mirrors..Iaddend.
.Iadd.42. The mirror assembly as in claim 41 wherein the source of
light includes at least two lasers..Iaddend.
.Iadd.43. The mirror assembly as in claim 28 wherein the light
source includes at least one laser, further including a mirrored
polygon having at least three sides, each side having a mirrored
surface and being disposed at an angle from the axis of the polygon
different than the angle of the other two sides, and wherein the
tertiary mirrors of the first and second sets of mirrors receive
light that has been reflected from the mirrored polygon and produce
at least six scan lines through the substantially vertical aperture
during each rotation of the mirrored polygon..Iaddend.
.Iadd.44. The mirror assembly as in claim 43 having just a single
substantially vertical aperture and just a single substantially
horizontal aperture, further including a housing having a first
housing section and a second housing section connected at proximate
ends forming a generally L-shaped structure, the substantially
vertical aperture being located in the first housing section and
the substantially horizontal aperture being located in the second
housing section..Iaddend.
.Iadd.45. An optical scanner comprising: a housing having a
substantially vertical surface containing a first aperture and a
substantially horizontal surface containing a second aperture; a
single laser which produces a laser beam within the housing; a
plurality of groups of pattern mirrors; a polygon spinner having
mirrored facets for reflecting the laser beam to produce a single
reflected beam in a plurality of directions as the spinner rotates
to cause the beam to strike at least some of the pattern mirrors,
to produce a plurality of scanning beams including a first group of
scanning beams, a second group of scanning beams, and a third group
of scanning beams; and a first group of pattern mirrors including a
first, second and third subsets of pattern mirrors for reflecting
the first group of scanning beams through the first aperture to
produce a first scan pattern consisting of a plurality of
intersecting scan lines, a second group of pattern mirrors
including a first, second and third subsets of pattern mirrors
reflecting the second group of scanning beams through the first
aperture to produce a second scan pattern consisting of a plurality
of intersecting scan lines; and a third group of pattern mirrors
for reflecting the third group of scanning beams through the second
aperture to produce a third scan pattern consisting of a plurality
of intersecting scan lines; the first group of scanning beams
reflecting off multiple mirrors of the first subset of pattern
mirrors of the first group to the second subset thereof, then
reflecting off multiple mirrors of said second subset to the third
subset thereof, and then off at least one mirror of said third
subset out the first aperture; the second group of scanning beams
reflecting off multiple mirrors of the first subset of pattern
mirrors of the first group to the second subset thereof, then
reflecting off multiple mirrors of said second subset to the third
subset thereof, and then off at least one mirror of said third
subset out the first aperture; the first subset of mirrors of the
first group include a plurality of generally trapezoidal mirrors;
the second subset of mirrors of the first group operate to receive
a light beam from said generally trapezoidal mirrors; and the third
subset of mirror of the first group is a generally trapezoidal
mirror which operates to receive a light beam from said second
subset mirrors of the first group..Iaddend.
.Iadd.46. An optical scanner as in claim 45, wherein the third
subset of mirrors in the second group includes multiple mirrors and
the scanning beams from the second subset of the second group
reflect off multiple mirrors of the second group and then pass out
the first aperture..Iaddend.
.Iadd.47. An optical scanner comprising: a housing having a
substantially vertical surface containing a first aperture and a
substantially horizontal surface containing a second aperture; a
single laser which produces a laser beam within the housing; a
plurality of groups of pattern mirrors; a polygon spinner having
mirrored facets for reflecting the laser beam in a plurality of
directions as the spinner rotates to produce a plurality of
scanning beams including a first group of scanning beams, a second
group of scanning beams, and a third group of scanning beams; and a
first group of pattern mirrors including a first, second and third
subsets of pattern mirrors for reflecting the first group of
scanning beams through the first aperture to produce a first scan
pattern consisting of a plurality of intersecting scan lines, a
second group of pattern mirrors including a first, second and third
subsets of pattern mirrors reflecting the second group of scanning
beams through the first aperture to produce a second scan pattern
consisting of a plurality of intersecting scan lines, each of the
subsets of the second group having multiple mirrors; and a third
group of pattern mirrors including a first and second subsets of
pattern mirrors for reflecting the third group of scanning beams
through the second aperture to produce a third scan pattern
consisting of a plurality of intersecting scan lines; the first
subset of mirrors of the first group include a plurality of
generally trapezoidal mirrors; the second subset of mirrors of the
first group operate to receive a light beam from said generally
trapezoidal mirrors; the third subset of mirrors of the first group
is a generally trapezoidal mirror which operates to receive a light
beam from said second subset of mirrors of the first group; the
first group of scanning beams reflecting off the first subset of
pattern mirrors of the first group to the second subset thereof,
then reflecting off said second subset to the third subset thereof,
and then off said third subset out the first aperture, the second
group of scanning beams reflecting off the first subset of pattern
mirrors of the first group to the second subset thereof, then
reflecting off said second subset to the third subset thereof, and
then off said third subset out the first aperture, at least one of
the mirrors of the first group of pattern mirrors being positioned
adjacent the first aperture to reflect certain of the first group
of scanning beams outwardly through the first aperture to scan the
side of an article, at least one of the mirrors of the second group
of pattern mirrors being positioned adjacent the first aperture and
angled to reflect certain of the first group of scanning beams
outwardly and laterally through the first aperture toward the
leading side of the article, and at least one positioned adjacent
the first aperture and angled to reflect certain of the first group
of scanning beams outward and laterally through the first aperture
to scan the trailing side of the article, and at least one of the
mirrors of the first group of pattern mirrors being positioned
adjacent the first aperture and angled to reflect certain of the
first group of scanning beams downwardly and outwardly through the
first aperture to scan the top of the article..Iaddend.
.Iadd.48. A method of scanning an item having a bar code from
multiple directions, comprising the steps of generating laser
light; providing a single multi-faceted mirrored polygon in a path
of said laser light; rotating the mirror polygon and directing the
laser light at the polygon, as it is rotating, to produce a single
laser beam reflected off each facet of the polygon; generating a
first group of scanning beams, a second group of scanning beams,
and a third group of scanning beams by reflecting said laser light
off said mirror polygon and then reflecting the laser beam off
groups of pattern mirrors; generating the first group of scanning
beams comprises directing the laser beam to a first set of
generally trapezoidal pattern mirrors, reflecting the beam from
those mirrors to a second set of generally trapezoidal pattern
mirrors and reflecting the beam from those mirrors to at least one
additional generally trapezoidal pattern mirror; directing said
first group of scanning beams from said at least one additional
mirror through a first transparent member oriented in a first plane
to scan a surface of the item from one orthogonal direction to scan
at least the top of an item; generating the second plurality of
scanning beams comprises directing the laser beam to a third set of
pattern mirrors, reflecting the beam from those mirrors to a fourth
set of pattern mirrors and reflecting the beam from those mirrors
to a fifth set of pattern mirrors; directing said second group of
scanning beams from at least one mirror of said fifth set of
mirrors directly outwardly through the first transparent member
oriented in the first plane to scan one side of the item and from
further mirrors of said fifth set of mirrors diagonally outwardly
through the first transparent member oriented in the first plane to
scan the item from a diagonal direction to scan the leading and
trailing sides of the item; and generating the third plurality of
scanning beams comprises directing the single laser beam to a sixth
set of pattern mirrors, reflecting the beam from those mirrors to a
seventh set of pattern mirrors and reflecting the beam from the
mirrors of the seventh set, directing said third group of scanning
beams from said seventh set of mirrors through a second transparent
member oriented in a second plane orthogonal to said first plane to
scan the item from another orthogonal direction to scan at least
the bottom of the item..Iaddend.
.Iadd.49. A method of scanning as in claim 48 wherein the first
group of scanning beams is directed through the first transparent
window in an outwardly and downwardly direction to scan the top of
the item, and the second group of scanning beams is directed
through the first transparent window in at least a diagonally
rearward direction and a diagonally forward direction to scan the
leading and trailing sides of the item..Iaddend.
.Iadd.50. A method of scanning as in claim 49 wherein certain of
the beams of the second group are directed through the first
transparent window in a diagonally rearward direction to scan the
leading side of the item, other beams of the second group are
directed through the first transparent window in a diagonally
forward direction to scan the trailing side of the item and other
beams of the second group are directed outwardly through the first
transparent window in a generally lateral direction to scan another
side of the item..Iaddend.
.Iadd.51. A method of scanning as in claim 48 where at least
certain of the third group of scanning beams is generated by
directing the beam from the polygon between mirrors of either the
first or second set to the mirrors of the sixth set..Iaddend.
.Iadd.52. A method of scanning as in claim 48 wherein scanning
beams are directed through the first transparent window and through
the second transparent window alternatingly, and this alternative
operation occurs repeatedly, for beams originating from a single
facet of the polygon, during each rotation of the
polygon..Iaddend.
.Iadd.53. A method of scanning as in claim 48 wherein generating
laser light comprises generating a single laser beam, and only said
single laser beam is reflected off each of the facets of the
polygon..Iaddend.
.Iadd.54. A method of scanning an item having a bar code from
multiple directions, comprising the steps of generating laser light
in the form of a single laser beam; providing a single
multi-faceted mirrored polygon in a path of said single laser light
beam; rotating the mirror polygon and reflecting the single laser
beam from each of the facets of the polygon, as the polygon is
rotating, to form from the single laser beam a plurality of
scanning beams that pass through both horizontal and vertical
transparent members; generating a first group of scanning beams, a
second group of scanning beams, and a third group of scanning beams
by reflecting said laser beam off said mirror polygon and then off
groups of pattern mirrors; generating the first group of scanning
beams comprises directing the laser beam to a first set of
generally trapezoidal pattern mirrors, reflecting the beam from
those mirrors to a second set of generally trapezoidal pattern
mirrors and reflecting the beam from those mirrors to at least one
additional generally trapezoidal pattern mirror; directing said
first group of scanning beams from said at least one additional
generally trapezoidal mirror through a vertical transparent member
oriented in a first plane to scan a surface of the item from one
orthogonal direction; generating the second plurality of scanning
beams comprises directing the laser beam to a third set of pattern
mirrors, reflecting the beam from those mirrors to a fourth set of
pattern mirrors and reflecting the beam from those mirrors to at
least one further mirror; directing said second group of scanning
beams from said at least one further mirror through the vertical
transparent member oriented in the first plane to scan the item
from a diagonal direction to scan at least one side of the item;
and generating the third plurality of scanning beams comprises
directing the laser beam to a fifth set of pattern mirrors,
reflecting the beam from those mirrors to a sixth set of pattern
mirrors and reflecting the beam from the mirrors of the sixth set,
directing said third group of scanning beams from said sixth set of
mirrors through a horizontal transparent member oriented in a
second plane orthogonal to said first plane to scan the item from
another orthogonal direction..Iaddend.
.Iadd.55. A method of scanning as in claim 54 wherein the first
group of scanning beams is directed through the first transparent
window in an outwardly and downwardly direction to scan the top of
an item, and the second group of scanning beams is directed through
the first transparent window in a diagonally rearward direction to
scan the leading side of an item..Iaddend.
.Iadd.56. A method of scanning as in claim 55 wherein certain of
the beams of the second group are directed through the first
transparent window in a diagonally rearward direction to scan the
leading side of an item, and other beams of the second group are
directed through the first transparent window in a diagonally
forward direction to scan the trailing side of an
item..Iaddend.
.Iadd.57. A scanner as in claim 54 wherein scan lines are directed
through the first transparent window and through the second
transparent window alternatingly, and this alternative operation
occurs repeatedly, for beams originating from a single facet of the
polygon, during each rotation of the polygon..Iaddend.
.Iadd.58. An optical scanner comprising: a housing having a
substantially vertical surface containing a first aperture and a
substantially horizontal surface containing a second aperture; a
single laser which produces a laser beam within the housing; a
polygon spinner having mirrored facets for reflecting the laser
beam in a plurality of directions to produce a plurality of
scanning beams including a first group of scanning beams, a second
group of scanning beams, and a third group of scanning beams; and a
plurality of pattern mirrors, including a plurality of groups of
pattern mirrors, for reflecting the first group of scanning beams
through the first aperture to produce a first scan pattern
consisting of a plurality of intersecting scan lines, for
reflecting the second group of scanning beams through the first
aperture to produce a second scan pattern consisting of a plurality
of intersecting scan lines, and for reflecting the third group of
scanning beams through the second aperture to produce a third scan
pattern consisting of a plurality of intersecting scan lines;
wherein the pattern mirrors include a first group of generally
trapezoidal mirrors for reflecting the laser beam from the spinner;
a second group of generally trapezoidal mirrors for reflecting the
laser beam from the first group of mirrors, including at least one
mirror positioned and angled to reflect an incident beam in a
substantially vertical direction to scan the bottom of an article
and at least one mirror is positioned and angled to reflect an
incident beam rearwardly to scan the forward side of the article;
and a third group of generally trapezoidal mirrors for reflecting
the laser beam from some of the mirrors in the second group of
mirrors..Iaddend.
Description
BACKGROUND OF THE INVENTION
The present invention relates to optical scanners and more
specifically to an optical scanner having enhanced item side
coverage.
.[.U.S. Pat. No. 5,229,588 to Detwiler et al. discloses a dual
aperture optical scanner which includes horizontal and vertical
apertures. The scanning light beams from a single laser diode pass
through these apertures to provide coverage for up to four sides of
a scanned item: the side facing the vertical aperture (front), the
side facing the horizontal aperture (bottom), and the left and
right sides..].
.Iadd.U.S. Pat. No. 5,229,588 to Detwiler et al. disclosed a dual
aperture optical scanner which includes horizontal and vertical
apertures. The scanning light beams from a single laser diode pass
through these apertures to provide coverage for the bottom and
sides of a scanned item..Iaddend.
.[.While this scanner requires much less item orientation than a
single aperture scanner, it is not capable of scanning the top and
rear sides of scanning items. Therefore, it would be desirable to
provide an optical scanner which is capable of scanning as many as
five sides of a typical merchandise item..].
.Iadd.While this scanner requires much less item orientation than a
single aperture scanner, it is not capable of scanning the top of
items. Therefore, it would be desirable to provide an optical
scanner which is capable of scanning the top, bottom and sides of a
typical merchandise item using an increased number of scan
lines..Iaddend.
SUMMARY OF THE INVENTION
In accordance with the teachings of the present invention, an
optical scanner having enhanced item side coverage is provided. The
optical scanner preferably also includes a housing having first and
second apertures, a laser beam source, a mirrored spinner for
reflecting the laser beam in a plurality of directions, and a
plurality of pattern mirrors within the housing for reflecting the
laser beam from the spinner through the first and second apertures
to an article having a bar code label to be scanned. Preferably,
the first aperture is substantially horizontal and the second
aperture is substantially vertical to maximize scan pattern
coverage and to minimize required item orientation.
The optical scanner also preferably includes an optical transceiver
for passing the laser beam and for collecting reflected light from
the scanned article and a photodetector for generating signals
representing the intensity of the light reflected from the
article.
The scanner of the present invention produces horizontal, vertical,
and diagonal scan patterns. A first set of pattern mirrors is
positioned adjacent the horizontal aperture. A second set of
pattern mirrors is positioned adjacent the vertical aperture and
includes first, second, and third subsets of pattern mirrors. The
spinner reflects a first group of scanning beams across the first
set of pattern mirrors and out the first window, reflects a second
group of scanning beams across the first and third subsets of
pattern mirrors and out the second window, and reflects a third
group of scanning beams across the second and third subsets of
pattern mirrors and out the second window.
It is a feature of the present invention that the mirrored spinner
and pattern mirrors combine to produce a plurality of scan lines
which pass through the horizontal and vertical apertures. The
scanner produces a scan pattern which more effectively covers
multi-sided articles than single aperture scanners. The mirrored
spinner includes four facets which are oriented at different angles
with respect to a predetermined reference. The pattern mirrors are
flat and include a first set of mirrors for reflecting the laser
beam from the spinner, a second set of mirrors for reflecting the
laser beam from the first set of mirrors, and for some scan lines,
a third set of mirrors for reflecting the laser beam from the
second set of mirrors. Preferably, the optical scanner produces
forty scan lines.
It is accordingly an object of the present invention to provide an
improved dual aperture optical scanner having enhanced item
coverage.
It is another object of the present invention to provide an
improved dual aperture optical scanner in which a first aperture is
substantially vertical and a second aperture is substantially
horizontal.
It is another object of the present invention to provide a dual
aperture optical scanner which substantially increases the
illuminated surface area of an article to be scanned.
It is another object of the present invention to provide a dual
aperture optical scanner which may be suitably employ a single
laser and motor for cost conscious applications in which cost may
be design determinant.
BRIEF DESCRIPTION OF THE DRAWINGS
Additional benefits and advantages of the present invention will
become apparent to those skilled in the art to which this invention
relates from the subsequent description of the preferred
embodiments and the appended claims, taken in conjunction with the
accompanying drawings, in which:
FIG. 1 is a block diagram of the optical scanner having enhanced
item side coverage of the present invention;
FIG. 2 is an exterior perspective view of the scanner of the
present invention, including a reference coordinate system for the
group of pattern mirrors within the scanner of the present
invention;
FIG. 3 is an interior perspective view of the scanner of the
present invention;
FIG. 4 is a sectional view of the scanner of the present invention
along lines 4-4 of FIG. 3;
FIG. 5 is a reference coordinate system for determining
one-suitable orientation for the group of pattern mirrors within
the scanner of the present invention;
FIG. 6 is a plan view of the scan pattern emanating upwardly from a
horizontal aperture;
FIG. 7 is a plan view of a first scan pattern emanating outwardly
from a vertical aperture;
FIG. 8 is a plan view of a second scan pattern emanating outwardly
from the vertical aperture;
FIG. 9 is a plan view of the combined first and second scan
patterns of FIGS. 7 and 8; and
FIG. 10 is a perspective view of a laser assembly showing two
lasers.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to FIG. 1, a point-of-service (POS) system 10
includes optical scanner 11 and POS terminal 13.
POS terminal 13 receives transaction data, for example, in the form
of SKU numbers from scanner 11 and completes a transaction by
finding price data for the SKU numbers in a price-lookup data
file.
Scanner 11 of the present invention includes laser 12, optical
transceiver 14, mirrored spinner 16, pattern mirrors 18, deflector
mirror 19, photodetector 20, and control circuit 21. Laser 12
includes a laser diode or other suitable laser source.
A focusing lens or lenses and a collimating aperture are also
preferably used to produce a focused and collimated laser beam 22.
In the preferred embodiment, the laser diode emits visible light
within a wavelength range of 670-690 nm and the collimating
aperture and focusing lens produce a beam 22 having a beam waist of
220 microns in the center of the read zone. Other wavelengths and
beam waists may be suitably employed.
Beam 22 passes through optical transceiver 14, which includes a
mirrored collecting surface and an aperture for passing beam 22.
The mirrored collecting surface preferably has an ellipsoidal or
other curved surface.
Beam 22 contacts mirrored spinner 16, which preferably has four
planoreflective mirrored facets 108-114 for producing scanning
beams 24 (FIG. 3). Four facets were chosen as an optimal compromise
between the increased line length created by using three facets and
the increased rastering provided by spinners having more than four
facets.
Scanning beams 24 impact pattern mirrors 18, which produce a
plurality of scan lines 26. In the preferred embodiment, pattern
mirrors 18 are preferably flat and produce forty scan lines 26 for
each complete revolution of mirrored spinner 16. Advantageously,
all forty scan lines 26 are preferably produced by only one laser
12 and motor 17. Use of a greater or lesser number of scan lines
and pattern mirrors will be apparent to those skilled in the
art.
Some scan lines 26 pass through a substantially horizontal aperture
28 and some pass through a substantially vertical aperture 30 in
scanner housing 32 on their way to bar code label 34 on merchandise
item 36. Substantially vertical aperture 30 is preferably oriented
at 53/4 degrees from a vertical plane. The choice of angle is
chosen to optimize the scan volume and line length of the scan
lines. It is desirable to achieve a ratio of the minimum length of
the longest scan line to the maximum length of the shortest scan
line as close as possible to one. At about ten degrees, scanning is
adversely impacted for the configuration of pattern mirrors 18
illustrated herein.
According to the present invention, scan lines 26 are divided into
three groups. Scan lines within a first group (Group I) emanate
outwardly and downwardly from vertical aperture 30 to illuminate
the top and customer sides of an item.
Scan lines within a second group (Group II) emanate outwardly from
aperture 30 as three sub-groups to illuminate the customer side
(Sub-group IIa), the customer and leading sides (Sub-group IIb),
and customer and trailing sides (Sub-group IIc).
Scan lines from the third group (Group III) emanate upwardly from
horizontal aperture 28 as three sub-groups to illuminate the bottom
(Sub-group IIIa), leading side (Sub-group IIIb), and trailing side
(Sub-group IIIc).
Reflected light 37 is redirected by pattern mirrors 18 towards
spinner 16, which further directs it towards optical transceiver
14. Optical transceiver 14 directs and focuses reflected light 37
at deflector mirror 19, which further directs reflected light 37
towards photodetector 20. Photodetector 20 generates electrical
signals representing the intensity of reflected light 37.
Control circuitry 21 decodes bar code label 34 and controls power
to laser 12 and motor 17. Control circuitry 21 may remove power
from laser 12 and motor 17 to increase the longevity of laser 12
and motor 17. When scanner 11 is equipped with two lasers (FIG.
10), control circuitry 21 alternates power removal from lasers 140
and 142. For example, control circuitry 21 may remove power from
laser 140 during one complete revolution of spinner 16, and remove
power from laser 142 during the following revolution.
Turning now to FIG. 2, scanner 11 is shown in perspective.
Horizontal aperture 28 is located within substantially horizontal
surface 38 of housing 32. Vertical aperture 30 is located within
substantially vertical surface 40.
Preferably, scanner 11 may be easily adapted to fit in a typical
checkout counter 42. Standard dimensions for apertures in checkout
counters like checkout counter 42 are about eleven inches in length
(i.e., in the direction of item flow), twenty inches in width
(i.e., in the direction across the direction of item flow), and
five inches deep. Thus, despite its improved scan coverage, scanner
11 easily fits within standard apertures. This is due to the
optimal size and arrangement of components within scanner 11.
It is envisioned that top surface 38 be made substantially flush
with the top surface 44 of counter 42, and also include a scale 43.
Scanner 11 is installed within checkout counter 42 so that
substantially vertical aperture 30 faces a store employee.
Referring now to FIGS. 3 and 4, the presently preferred arrangement
of scanner components is shown in more detail. Laser 12 is
preferably oriented at thirty-five degrees from the horizontal or
X-axis as shown in FIG. 2. Laser 12 is mounted within a bracket 15
which attaches to the lower wall of scanner 11. Beam 22 contacts
planoreflective surfaces 108-114 of mirrored spinner 16 (FIG. 4).
Spinner axis 116 is preferably oriented at twenty-two and a half
degrees from a vertical or Z-axis. Facets 108-114 are preferably
oriented at two and half degrees, four degrees, seven degrees, and
eight and a half degrees, respectively, from spinner axis 116.
These angles cause spinner 16 to generate four different sets of
scan lines (Table III below) and are chosen to balance spinner 16
as much as possible consistent with the goal of generating four
different sets of scan lines.
Pattern mirrors 18 are all preferably flat mirrors. Scanning beams
24 from spinner 16 impact a first set of mirrors 50-72 and reflect
therefrom to a second set of mirrors 74-98. Mirrors 80-98 within
the second set further direct beams 24 to a third set of mirrors
100-106.
The reference coordinate system for mirrors 50-106 is shown in
FIGS. 2 and 5, and includes X, Y, and Z axes, with the Z-axis being
out of the page. Coordinates Xm, Ym, and Zm are measured in inches,
and angles Xr and Yr, are measured in degrees, with positive angles
being measured in a counter-clockwise direction. Pattern mirrors 18
are positioned or located with respect to this coordinate system as
described below. Each mirror is first oriented parallel to the X-Y
plane through a point (Xm, Ym Zm). Each mirror is rotated through
an angle Xr about a line X parallel to the X-axis and containing
the point (Xm, Ym, Zm). Each mirror is rotated through an angle Yr
about a line Y parallel to the Y-axis and containing the point (Xm,
Ym Zm). Thus, these five variables uniquely define planes for
mirrors 50-106 and are shown in Table I. Presently preferred values
are shown.
Origin 0 is defined such that:
X=0 is on the centerline of the scanner;
Z=0 is on the centerline of the scanner; and
Y=0 is on the substantially horizontal surface 38.
TABLE-US-00001 TABLE I Mirror Xm Ym Zm Xr Yr 50 +3.375 -0.825
+3.200 +19.50 -108.50 52 +4.200 -0.825 +0.010 +24.00 -100.00 54
+4.200 -0.825 -0.010 +24.00 -80.00 56 +3.375 -0.825 -3.200 +19.50
-71.50 58 -3.400 -2.010 +4.345 +14.00 -168.25 60 -3.400 -2.010
-4345 +14.00 -11.75 62 -3.905 -1.635 +3.850 -11.00 -125.00 64
-2.950 -3.410 +1.030 +21.50 -85.00 66 -2.950 -3.410 -1.030 +21.50
-95.00 68 -3.905 -1.635 -3.850 -11.00 -55.00 70 -5.430 -0.050
+4.720 -30.00 -132.50 72 -5.430 -0.050 -4.720 +30.00 -4730 74
-1.315 -2.300 +4.585 -30.00 -167.25 76 +4.900 -4.725 +0.000 -77.50
+90.00 78 -1.315 -2.300 -4.585 -30.00 -12.75 80 -5.185 -3.095
+3.795 -60.00 +77.50 82 -4.880 -2.910 +3.685 -66.00 +102.50 84
-4.600 -3.155 +4.040 -52.25 +136.25 86 -4.600 -3.165 +4.040 -58.75
+149.00 88 -4.600 -3.165 -4.040 -58.75 +31.00 90 -4.600 -3.155
-4.040 -52.25 +43.75 92 -5.185 -3.095 -3.795 -60.00 +102.50 94
-4.880 -2910 -3.685 -66.00 +77.50 96 -7.515 +0.485 +0.060 -37.00
+67.50 98 -7.515 +0.485 -0.060 -37.00 +112.50 100 -3.745 +6.250
+2.610 +50.00 +137.50 102 -6.420 +4.900 +0.000 +38.25 +90.00 104
-3.165 +6.275 +0.000 +69.25 +90.00 106 -3.745 +6.250 -2.610 +50.00
+42.50
Table II shows orientation and location data for the laser,
spinner, and photodetector:
TABLE-US-00002 TABLE II Component Xm Ym Zm Laser -4.050 -3.940
+0.000 Spinner -6.875 -2.175 +0.000 Photodetector -4.645 -4.580
+0.000
In operation, laser beam 22 strikes each facet of mirrored spinner
16 in sequence. Table III summarizes the facet and mirrors involved
in generating the forty scan lines (FIGS. 6-9) during one
revolution of spinner 16. The forty scan lines are arranged in the
sequence in which they are generated as spinner 16 rotates in a
counter-clockwise direction as viewed from above.
TABLE-US-00003 TABLE III Scan Primary Secondary Tertiary Line Facet
Mirror Mirror Mirror Group Sub-group H1 108 70 82 104 I O1 108 62
96 102 II IIa L1 108 64 86 104 I E1 108 50 76 III IIIA D1 108 52 76
III IIIa B1 108 54 76 III IIIA C1 108 56 76 III IIIa N1 108 66 88
104 I P1 108 68 98 102 II IIa I1 108 72 94 104 I G1 112 70 80 100
II IIb F2 112 58 78 III IIIc K1 112 64 84 104 I E3 112 50 76 III
IIIa D3 112 52 76 III IIIa B3 112 54 76 III IIIa C3 112 56 76 III
IIIa M1 112 66 90 104 I IIIa A2 112 60 74 III IIIb J1 112 72 92 106
II IIc H2 110 70 82 104 I O2 110 62 96 102 II IIa L2 110 64 86 104
I E2 110 50 76 III IIIa D2 110 52 76 III IIIa B2 110 54 76 III IIIa
C2 110 56 76 III IIIa N2 110 66 88 104 I P2 110 68 98 102 II IIa I2
110 72 94 104 I G2 114 70 80 100 II IIb F1 114 58 78 III IIIc K2
114 64 84 104 I E4 114 50 76 III IIIa D4 114 52 76 III IIIa B4 114
54 76 III IIIa C4 114 56 76 III IIIa M2 114 66 90 104 I A1 114 60
74 III IIIb J2 114 72 92 106 II IIc
Referring now to FIGS. 6-9, horizontal scan pattern 120, vertical
scan pattern 122, and top-down scan pattern 124 are shown. Some of
scan lines 26 appear to be curved. This is because scan beams 24
from spinner 16 do not lie in a flat plane; they lie on the surface
of a shallow cone. The curvature of scan lines 26 represents the
intersection of that cone and a particular intersecting plane
(e.g., an aperture). The amount of curvature depends on the
relative angle between the projected cone and this plane. Since the
cone of light projects at different angles for the various scan
lines 26, scan lines 26 may appear to have different
curvatures.
Horizontal scan pattern produces Group III scan lines which emanate
from horizontal aperture 28. Scan lines within Sub-group IIIa
include B1-B4, C1-C4, D1-D4, and E1-E4. Scan lines within Sub-group
IIIb include A1-A2. Scan lines within Sub-group IIIc include F1-F2.
Side 130 of aperture 28 is the operator side.
Vertical scan pattern 122 (FIG. 7) produces Group II scan lines
which emanate from vertical aperture 30. Scan lines within
Sub-group IIa include 01-02 and P1-P2. Scan lines within Sub-group
IIb include G1-G2. Scan lines within Sub-group IIc include J1-J2.
Side 132 of aperture 30 is the top side.
Top-down scan pattern 124 (FIG. 8) produces Group I scan lines
which emanate from vertical aperture 30 and include scan lines
H1-H2, Ii-I2, K1-K2, L1-L2, M1-M2, and N1-N2.
FIG. 9 illustrates the combined scan lines emanating from vertical
aperture 30.
Turning now to FIG. 10, bracket 15 may contain two lasers 140 and
142. Lasers 140 and 142 are preferably combined such that their
laser beams are co-linear. This is accomplished by using a
transparent window 144 with one partially reflective side 146.
Window 144 is mounted on a support member and placed in front of
laser 140 so that its beam strikes window 144 at a forty-five
degree incidence angle. Laser 142 is oriented so that its beam is
orthogonal to the beam of laser 140 and has a forty-five degree
incidence angle with window 146. The resulting co-linear beams of
both lasers 140 and 142 are parallel to and substantially co-linear
with the path of the beam of laser 12 in the single-laser
embodiment.
Additional lasers may be easily incorporated by adding additional
windows. Bracket 15 may be easily modified to accommodate three or
more lasers.
Preferably, lasers 140 and 142 are substantially identical and have
substantially identical foci. The foci are preferably offset to
increase the effective depth of field of scanner 11. Alternatively,
the foci of lasers 140 and 142 may be different to enable scanner
11 to read bar codes of various spatial frequencies.
Although the invention has been described with particular reference
to certain preferred embodiments thereof, variations and
modifications of the present invention can be effected within the
spirit and scope of the following claims.
* * * * *