CA1068141A - Scanning apparatus using holographic beam deflector - Google Patents
Scanning apparatus using holographic beam deflectorInfo
- Publication number
- CA1068141A CA1068141A CA268,097A CA268097A CA1068141A CA 1068141 A CA1068141 A CA 1068141A CA 268097 A CA268097 A CA 268097A CA 1068141 A CA1068141 A CA 1068141A
- Authority
- CA
- Canada
- Prior art keywords
- scanning
- segments
- hologram
- window
- produce
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Classifications
-
- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06K—GRAPHICAL DATA READING; PRESENTATION OF DATA; RECORD CARRIERS; HANDLING RECORD CARRIERS
- G06K7/00—Methods or arrangements for sensing record carriers, e.g. for reading patterns
- G06K7/10—Methods or arrangements for sensing record carriers, e.g. for reading patterns by electromagnetic radiation, e.g. optical sensing; by corpuscular radiation
- G06K7/10544—Methods or arrangements for sensing record carriers, e.g. for reading patterns by electromagnetic radiation, e.g. optical sensing; by corpuscular radiation by scanning of the records by radiation in the optical part of the electromagnetic spectrum
- G06K7/10821—Methods or arrangements for sensing record carriers, e.g. for reading patterns by electromagnetic radiation, e.g. optical sensing; by corpuscular radiation by scanning of the records by radiation in the optical part of the electromagnetic spectrum further details of bar or optical code scanning devices
- G06K7/10861—Methods or arrangements for sensing record carriers, e.g. for reading patterns by electromagnetic radiation, e.g. optical sensing; by corpuscular radiation by scanning of the records by radiation in the optical part of the electromagnetic spectrum further details of bar or optical code scanning devices sensing of data fields affixed to objects or articles, e.g. coded labels
- G06K7/10871—Methods or arrangements for sensing record carriers, e.g. for reading patterns by electromagnetic radiation, e.g. optical sensing; by corpuscular radiation by scanning of the records by radiation in the optical part of the electromagnetic spectrum further details of bar or optical code scanning devices sensing of data fields affixed to objects or articles, e.g. coded labels randomly oriented data-fields, code-marks therefore, e.g. concentric circles-code
-
- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B26/00—Optical devices or arrangements for the control of light using movable or deformable optical elements
- G02B26/08—Optical devices or arrangements for the control of light using movable or deformable optical elements for controlling the direction of light
- G02B26/10—Scanning systems
- G02B26/106—Scanning systems having diffraction gratings as scanning elements, e.g. holographic scanners
Abstract
SCANNING APPARATUS USING HOLOGRAPHIC BEAM DEFLECTOR
Abstract of the Disclosure An omnidirectional scanning apparatus which generates a multiple cross scanning pattern is described. The scanning apparatus comprises a flat ring-shaped hologram. The hologram disk is rotated about its axis as a small area is illuminated by a collimated light source, such as a laser, to produce a series of reconstructed beams which scan segments of a circle.
Optical means is provided to intercept the reconstructed beams and reflect them to a scanning window where the segments produce a multiple cross scanning pattern. In a specific embodiment the holograms recorded are reconstructed as segments of con-centric circles and the optical means comprises a stationary mirror for each direction of scan across the scanning window.
Abstract of the Disclosure An omnidirectional scanning apparatus which generates a multiple cross scanning pattern is described. The scanning apparatus comprises a flat ring-shaped hologram. The hologram disk is rotated about its axis as a small area is illuminated by a collimated light source, such as a laser, to produce a series of reconstructed beams which scan segments of a circle.
Optical means is provided to intercept the reconstructed beams and reflect them to a scanning window where the segments produce a multiple cross scanning pattern. In a specific embodiment the holograms recorded are reconstructed as segments of con-centric circles and the optical means comprises a stationary mirror for each direction of scan across the scanning window.
Description
Background of the Invention 16 This invention relates to optical scanning systems and --17 more particularly to omnidirectional scanning systems.
18 There have been available in the prior art omnidirectional 19 systems which finds particular application for scanning randomly oriented coded labels which, for example, are attached to 21 consumer items being checked out at a counter. The chec~out 22 operator merely passes the item over a narrow rectangular 23 scanning window to sense the data from the coded labels.
24 However, the use of the narrow rectangular scanning window requires a multiple cross scanning pattern to insure that the 26 coded label will be properly scanned. Prior art systems utiliz-27 ing this scanning pattern have generally utilized some arrange-28 ment with oscillating or rotating mirrors.
29 It is the principal object of this invention to produce a simplified and therefore less expensive multiple cross 31 scanning system.
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'~, . ' ' . ~- ' ' ' 10681~1 1 Summary of the Invention'
18 There have been available in the prior art omnidirectional 19 systems which finds particular application for scanning randomly oriented coded labels which, for example, are attached to 21 consumer items being checked out at a counter. The chec~out 22 operator merely passes the item over a narrow rectangular 23 scanning window to sense the data from the coded labels.
24 However, the use of the narrow rectangular scanning window requires a multiple cross scanning pattern to insure that the 26 coded label will be properly scanned. Prior art systems utiliz-27 ing this scanning pattern have generally utilized some arrange-28 ment with oscillating or rotating mirrors.
29 It is the principal object of this invention to produce a simplified and therefore less expensive multiple cross 31 scanning system.
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'~, . ' ' . ~- ' ' ' 10681~1 1 Summary of the Invention'
- 2 ~riefly, according to the invention, the scanning appara-
3 tus comprises a disk member having a plurality of holograms
4 recorded thereon. A small area of the disk member is illumin-ated by a collimated light source as the disk member is 6 rotated about its axis. Each hologram on the disk produces a 7 reconstructed beam which scans a circular arc. Optical means 8 are provided to intercept the reconstructed beams and to reflect 9 the intercepted beams to a scanning window to produce a multiple cross scanning pattern on the scanning window. In a specific 11 embodiment a series of concentric circular segments are produced 12 by the reconstructed beams and the optical means comprises a 13 stationary mirror for each direction of scan across ~hc scanning 14 wiAdow.
Brief Descri~tlon of the Draw~~
16 FIG. 1 is a schematic view of the scanning apparatus 17 embodying the invention.
18 FIG. 2 is a diagram showing the geometry illustrating 19 formation of the hologram for one specific embodiment of the scanning apparatus embodying the invention.
21 FIG. 3 is a diagram showing the scanning segments generated 22 by the subsequent reconstruction of the hologram formed as 23 shown in FIG. 2.
24 FIG. 4 is a diagram showing a specific embodiment of apparatus for producing the superposition of the various 26 scanning segments shown in FIG. 3 onto a scanning window by 27 the use of stationary mirrors.
28 FIG. 5 shows views a and b of a diagram showing the 29 geometry illustra*ing the formation of a ring shaped hologram.
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1 FIG. 6 is a diagram showing the geometry relating to the 2 formation of a hologram on a ring sector.
3 FIG. 7 is a diagram illustrating the dependence of the 4 scanning angle upon the position of a recorded sector hologram.
FIG. 8 is a diagram showing the ideal scanning pattern 6 for a multiple cross scanner.
7 Detailed Description of the Preferred Embodiments 8 My invention is described in the setting of a checkout 9 stand application, however, it will be recognized by those skilled in the art that the invention is also suitable for 11 other applications.
12 Referring to the schematic view of the scanning apparatus 13 shown in FIG. 1, the scanning apparatus comprises a holographic 14 disk member 10 having a plurality of holograms 12a, 12b-12n recorded on its periphery. A collimated light beam 14 emitted 16 from laser 16 impinges on disk member 10 to produce a recon-17 structed convergent beam 18. Motor 20 is connected to holo-18 graphic member 10 to rotate it about the axis of disk 10 19 thereby causing the beam 14 to illuminate successive holo-grams 12. This action causes the reconstructed beam 18 to 21 scan a circular path in a plane parallel to the plane of 22 hologram disk 10. The holograms 12 are recorded so that as ; 23 each hologram is illuminated by beam 14, the reconstructed 24 beam 18 scans a predetermined circular segment 28a, 28b-28n.
For convenience in illustrating the shape of the recon-26 structed beam the cross-sectional area of beam 14 is shown 27 out of proportion relative to the size of holograms 12. The 28 preferred diameter of the illuminating beam cross-sectional _3_ 10~8i~1 1 area is on the order sf ~ne-tenth of the width of the .: . .
2 holograms 12.
3 The patterns shown in FIG. 8 are the scanning patterns 4 produced at a suitable scanning window 26. Scanning window 26 is a narrow rectangular aperture formed in the top of an 6 enclosure (not shown) and covered by glass or other suitable 7 material transparent to 'the light generated by laser 16. The 8 enclosure forms a checkout stand where an item of merchandise 9 bearing a bar coded label is transported over the scanning window so that the label data is recovered by means known in 11 the art.
12 By the selection of appropriate circular segments 28 13 and the proper positioning of these segments relative to 14 ~canning window 26, a crossed interlaced scanning pattern can be~produced as shown in FIG. 8~b) which approximates the 16 ideal crossed scanning pattern shown in FIG. 8~a). The 17 larger the radius of the circular segments 28, the closer the 18 approximation comes to the ideal scanning pattern. The 19 allowable radius or the segments is determined by the tolerance on the diameter of the reconstructed light spot 21 and the tolerable angle of incidence of the reconstructed 22 light beam with respect to scanning window 26.
23 Optical means are provided to intercept the reconstructcd 24 ~eams and to reflect the intcrceptcd beam to the scanning 25' window 26 so that the various segments 28 are positioned in 26 their proper relative positions to produce the approximations 27 to the scanning pattern shown in FIG. 8(b).
28 To produce the scanning pattern shown in FIG. 1, a first 29 optical means 22 is provided to intercept a first reconstructed beam 18 and reflect it to a first orientation on scanning . ~ .
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~ 0681~:1 1 window 26 to produce a first scanning segment 28a. A second 2 optical means 24 is provided to intercept a second reconstructed 3 beam 18 and reflect it to a second orientation on scanning 4 window 26 to produce a second scanning segment 28b which inter-sects segment 28a at an angle substantially midway of the 6 narrow dimension of the scanning window 26 to form a crossed i 7 scanning pattern~ Third optical means 37 is provided to 8 intercept a third reconstructed beam 18 and reflect it to a 9 third orientation on scanning window 26 to produce a third scanning segment 28c which essentially bisects the area of 11 scanning window 26 and produces a common intersection point 12 with scanning segments 28a and 28b. The other scanning segments 13 are produced in a similar manner. The set of holograms 12a, 14 12b-12n required to produce one scanning pattern can be repeated several times along the circumference of the disk 16 10 so that the whole scanning pattern is run through several 17 times in one revolution of the disk.
18 The principle of operation of the scanning apparatus can 19 be better understood by referring to the diagrams shown in FIGS. 5, 6, and 7. Holographic disc member 10 is formed 21 f~om any suitable material and at least the outer peripheral 22 area 11 is transparent to the light from laser 16. The holo-23 grams 12 are recorded on area 11 while the disk is rotated 24 about an axis through the center of the disk 10. The reference wave 15 (see FIG. 5) at the hologram recording stage has 26 rotational symmetry with respect to the axis through the center 27 of disk member 10 and the reference wa~e 15 is a collimated 28 beam incident perpendicular to the hologram plane, The object 29 beam 17 is a sphcrically divcrgent wave whose origin is located at the distance R from the axis of rotation and the distance ~
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10~81~1 1 from the holo~ram plane. In the reconstruction step the hoio-2 gram is illuminated by the conjugate reference wave 19, which ~ is a collimated beam propagating in the opposite direction 4 from the reference wave. If the whole hologram is illuminated by that beam, a ring section of a spherical wave will be re-6 constructed which converges toward the origin of the former 7 object wave. If the hologram is rotated, this reconstructed 8 pQint describes a circular path of radius R in a parallel 9 plane to the hologram plane at the distance H. However, if only a sector 21 of the ring hologram was made (see FIG. 6) 11 and is now illuminated, only the corresponding part of the 12 spherical wave will be reconstructed. The central ray of the 13 reconstructed wave 23 forms an angle ~ with the accompanying 14 hologram radius (see FIG. 7). By choosing the suitable sector of the whole ring ~r ~ ~e' the angle ~ can be adjusted to any 16 desired value within the range +180 degrees. If the reconstruc-17 tion beam is ixed illuminating only a relatively small area 18 25 while the hologram is rotating, a point is reconstructed 19 which scans a part 27 of the circular path of radius R when the previously recorded hologram sector passes the illuminated 21 a~ea.
22 Thus, for a fixed position of the reconstruction beam 23 and any given segment of a concentric circle of radius R
24 and distance H from the hologram plane, it is possible to find an appropriate sector on the hologram ring of radius R, 26 so that a previously re~orded hologram on this sector will 27 make the reconstructed point to scan exactly the desired 28 segment.
29 For the embodiment of the scanning apparatus shown in -FIG. 3, the hologram disk member 10' is recorded with seven --.. ' '' ' .
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10681~1 j 1 different hologram~segments 29-1, 29-2, - 29-7 recorded on 2 seven ring sectors following each other tsee FIG. 2). The 3 adjacent areas are masked off as each of these segments is 4 recorded. The angles ~r and ~e of each hologram are chosen S so that the line segments 30-36 (see FIG. 4) are scanned 6 subsequently by the reconstructed beams when the seven seg-7 ments are rotated past the laser beam.
8 In the specific embodiment of the invention shown in ' 9 FIGS. 3 and 4 the hologram disk member 10' is recorded so that illumination of a small area 25 (as previously mentio~ed, 11 the cross-sectional area of the illumination beam, such as 25, 12 is much smaller than that shown in FIG. 3) of the disk by beam 13 14 and subsequent rotation of disk member 10' produces seven 14 reconstructed beams which scan segments 30, 31, 32, 33, 34, 35, 36. Each of the segments 30-36 represents a segment of a I6 concentric circle and segments 30, 31 32 produce spaced scans ~ . .
17 in one direction at an angle across window area 38. Segments 18 34, 35, 36 produce spaced scans in the opposite direction at 19 an angle across window area 40. Segment 33 essentially bisects the window area 42. In this embodiment the first optical 21 means comprises a stationary plane mirror 39 positioned to :
22 intercept the beams which produce segments 34, 35, 36 and 23 reflect these segments to scanning window 26. In this 24 embodiment the second optical means comprises a stationary plane mirror 41 positioned to intercept the beams which 26 produce segments 30, 31, 32 and reflect these segments to 27 scanning window 26. In addition, the third optical means 28 comprises a stationary plane mirror 44 positioned to intercept 29 the beam which forms segment 33 and to reflect this beam to : :
scanning window 26. The composite of the seven scanning seg-~ .
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1 ments on scanning ,window 26 produces the crossed scanning 2 pattern shown in FIG. 8b.
3 One specific embodiment of the apparatus using segments 4 of concentric circles to produce a crossed scanning pattern has been shown and described. Many other embodiments will 6 occur to those skilled in the art. For example, another 7 embodiment for the,apparatus comprises recording a series of 8 holograms which when reconstructed produce sets of shifted 9 segments of circles, all of the same radius R. In this case, a fixed plane mirror is required for each segment to be 11 scanned and each mirror is set at a different angle to direct 12 these segments to the interlaced cross-scanning pattern at the 13 scanning window.
14 While the invention has been particularly shown and de-scribed with reference to a preferred embodiment thereof, it 16 will be understood by those skilled in the art that various 17 changes in the form and details may be made therein without 18 departing from the spirit and scope of the invention.
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Brief Descri~tlon of the Draw~~
16 FIG. 1 is a schematic view of the scanning apparatus 17 embodying the invention.
18 FIG. 2 is a diagram showing the geometry illustrating 19 formation of the hologram for one specific embodiment of the scanning apparatus embodying the invention.
21 FIG. 3 is a diagram showing the scanning segments generated 22 by the subsequent reconstruction of the hologram formed as 23 shown in FIG. 2.
24 FIG. 4 is a diagram showing a specific embodiment of apparatus for producing the superposition of the various 26 scanning segments shown in FIG. 3 onto a scanning window by 27 the use of stationary mirrors.
28 FIG. 5 shows views a and b of a diagram showing the 29 geometry illustra*ing the formation of a ring shaped hologram.
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1 FIG. 6 is a diagram showing the geometry relating to the 2 formation of a hologram on a ring sector.
3 FIG. 7 is a diagram illustrating the dependence of the 4 scanning angle upon the position of a recorded sector hologram.
FIG. 8 is a diagram showing the ideal scanning pattern 6 for a multiple cross scanner.
7 Detailed Description of the Preferred Embodiments 8 My invention is described in the setting of a checkout 9 stand application, however, it will be recognized by those skilled in the art that the invention is also suitable for 11 other applications.
12 Referring to the schematic view of the scanning apparatus 13 shown in FIG. 1, the scanning apparatus comprises a holographic 14 disk member 10 having a plurality of holograms 12a, 12b-12n recorded on its periphery. A collimated light beam 14 emitted 16 from laser 16 impinges on disk member 10 to produce a recon-17 structed convergent beam 18. Motor 20 is connected to holo-18 graphic member 10 to rotate it about the axis of disk 10 19 thereby causing the beam 14 to illuminate successive holo-grams 12. This action causes the reconstructed beam 18 to 21 scan a circular path in a plane parallel to the plane of 22 hologram disk 10. The holograms 12 are recorded so that as ; 23 each hologram is illuminated by beam 14, the reconstructed 24 beam 18 scans a predetermined circular segment 28a, 28b-28n.
For convenience in illustrating the shape of the recon-26 structed beam the cross-sectional area of beam 14 is shown 27 out of proportion relative to the size of holograms 12. The 28 preferred diameter of the illuminating beam cross-sectional _3_ 10~8i~1 1 area is on the order sf ~ne-tenth of the width of the .: . .
2 holograms 12.
3 The patterns shown in FIG. 8 are the scanning patterns 4 produced at a suitable scanning window 26. Scanning window 26 is a narrow rectangular aperture formed in the top of an 6 enclosure (not shown) and covered by glass or other suitable 7 material transparent to 'the light generated by laser 16. The 8 enclosure forms a checkout stand where an item of merchandise 9 bearing a bar coded label is transported over the scanning window so that the label data is recovered by means known in 11 the art.
12 By the selection of appropriate circular segments 28 13 and the proper positioning of these segments relative to 14 ~canning window 26, a crossed interlaced scanning pattern can be~produced as shown in FIG. 8~b) which approximates the 16 ideal crossed scanning pattern shown in FIG. 8~a). The 17 larger the radius of the circular segments 28, the closer the 18 approximation comes to the ideal scanning pattern. The 19 allowable radius or the segments is determined by the tolerance on the diameter of the reconstructed light spot 21 and the tolerable angle of incidence of the reconstructed 22 light beam with respect to scanning window 26.
23 Optical means are provided to intercept the reconstructcd 24 ~eams and to reflect the intcrceptcd beam to the scanning 25' window 26 so that the various segments 28 are positioned in 26 their proper relative positions to produce the approximations 27 to the scanning pattern shown in FIG. 8(b).
28 To produce the scanning pattern shown in FIG. 1, a first 29 optical means 22 is provided to intercept a first reconstructed beam 18 and reflect it to a first orientation on scanning . ~ .
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~ 0681~:1 1 window 26 to produce a first scanning segment 28a. A second 2 optical means 24 is provided to intercept a second reconstructed 3 beam 18 and reflect it to a second orientation on scanning 4 window 26 to produce a second scanning segment 28b which inter-sects segment 28a at an angle substantially midway of the 6 narrow dimension of the scanning window 26 to form a crossed i 7 scanning pattern~ Third optical means 37 is provided to 8 intercept a third reconstructed beam 18 and reflect it to a 9 third orientation on scanning window 26 to produce a third scanning segment 28c which essentially bisects the area of 11 scanning window 26 and produces a common intersection point 12 with scanning segments 28a and 28b. The other scanning segments 13 are produced in a similar manner. The set of holograms 12a, 14 12b-12n required to produce one scanning pattern can be repeated several times along the circumference of the disk 16 10 so that the whole scanning pattern is run through several 17 times in one revolution of the disk.
18 The principle of operation of the scanning apparatus can 19 be better understood by referring to the diagrams shown in FIGS. 5, 6, and 7. Holographic disc member 10 is formed 21 f~om any suitable material and at least the outer peripheral 22 area 11 is transparent to the light from laser 16. The holo-23 grams 12 are recorded on area 11 while the disk is rotated 24 about an axis through the center of the disk 10. The reference wave 15 (see FIG. 5) at the hologram recording stage has 26 rotational symmetry with respect to the axis through the center 27 of disk member 10 and the reference wa~e 15 is a collimated 28 beam incident perpendicular to the hologram plane, The object 29 beam 17 is a sphcrically divcrgent wave whose origin is located at the distance R from the axis of rotation and the distance ~
" , .
, ~ .
. .
10~81~1 1 from the holo~ram plane. In the reconstruction step the hoio-2 gram is illuminated by the conjugate reference wave 19, which ~ is a collimated beam propagating in the opposite direction 4 from the reference wave. If the whole hologram is illuminated by that beam, a ring section of a spherical wave will be re-6 constructed which converges toward the origin of the former 7 object wave. If the hologram is rotated, this reconstructed 8 pQint describes a circular path of radius R in a parallel 9 plane to the hologram plane at the distance H. However, if only a sector 21 of the ring hologram was made (see FIG. 6) 11 and is now illuminated, only the corresponding part of the 12 spherical wave will be reconstructed. The central ray of the 13 reconstructed wave 23 forms an angle ~ with the accompanying 14 hologram radius (see FIG. 7). By choosing the suitable sector of the whole ring ~r ~ ~e' the angle ~ can be adjusted to any 16 desired value within the range +180 degrees. If the reconstruc-17 tion beam is ixed illuminating only a relatively small area 18 25 while the hologram is rotating, a point is reconstructed 19 which scans a part 27 of the circular path of radius R when the previously recorded hologram sector passes the illuminated 21 a~ea.
22 Thus, for a fixed position of the reconstruction beam 23 and any given segment of a concentric circle of radius R
24 and distance H from the hologram plane, it is possible to find an appropriate sector on the hologram ring of radius R, 26 so that a previously re~orded hologram on this sector will 27 make the reconstructed point to scan exactly the desired 28 segment.
29 For the embodiment of the scanning apparatus shown in -FIG. 3, the hologram disk member 10' is recorded with seven --.. ' '' ' .
, -6-i . ~ . . - . ~ . .
10681~1 j 1 different hologram~segments 29-1, 29-2, - 29-7 recorded on 2 seven ring sectors following each other tsee FIG. 2). The 3 adjacent areas are masked off as each of these segments is 4 recorded. The angles ~r and ~e of each hologram are chosen S so that the line segments 30-36 (see FIG. 4) are scanned 6 subsequently by the reconstructed beams when the seven seg-7 ments are rotated past the laser beam.
8 In the specific embodiment of the invention shown in ' 9 FIGS. 3 and 4 the hologram disk member 10' is recorded so that illumination of a small area 25 (as previously mentio~ed, 11 the cross-sectional area of the illumination beam, such as 25, 12 is much smaller than that shown in FIG. 3) of the disk by beam 13 14 and subsequent rotation of disk member 10' produces seven 14 reconstructed beams which scan segments 30, 31, 32, 33, 34, 35, 36. Each of the segments 30-36 represents a segment of a I6 concentric circle and segments 30, 31 32 produce spaced scans ~ . .
17 in one direction at an angle across window area 38. Segments 18 34, 35, 36 produce spaced scans in the opposite direction at 19 an angle across window area 40. Segment 33 essentially bisects the window area 42. In this embodiment the first optical 21 means comprises a stationary plane mirror 39 positioned to :
22 intercept the beams which produce segments 34, 35, 36 and 23 reflect these segments to scanning window 26. In this 24 embodiment the second optical means comprises a stationary plane mirror 41 positioned to intercept the beams which 26 produce segments 30, 31, 32 and reflect these segments to 27 scanning window 26. In addition, the third optical means 28 comprises a stationary plane mirror 44 positioned to intercept 29 the beam which forms segment 33 and to reflect this beam to : :
scanning window 26. The composite of the seven scanning seg-~ .
' ' ' ` ' .
., . .. : :
1~;~14~
1 ments on scanning ,window 26 produces the crossed scanning 2 pattern shown in FIG. 8b.
3 One specific embodiment of the apparatus using segments 4 of concentric circles to produce a crossed scanning pattern has been shown and described. Many other embodiments will 6 occur to those skilled in the art. For example, another 7 embodiment for the,apparatus comprises recording a series of 8 holograms which when reconstructed produce sets of shifted 9 segments of circles, all of the same radius R. In this case, a fixed plane mirror is required for each segment to be 11 scanned and each mirror is set at a different angle to direct 12 these segments to the interlaced cross-scanning pattern at the 13 scanning window.
14 While the invention has been particularly shown and de-scribed with reference to a preferred embodiment thereof, it 16 will be understood by those skilled in the art that various 17 changes in the form and details may be made therein without 18 departing from the spirit and scope of the invention.
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Claims (7)
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. An omnidirectional scanning system for scanning bar coded labels on randomly oriented articles comprising:
an elongated scanning window;
a disk member having a plurality of hologram segments recorded thereon, each of said hologram segments, when recon-structed, producing a point image, each of said reconstructed hologram segments producing different points in a plane which is parallel to the plane containing said hologram segments;
a collimated light source providing a beam of light directed to illuminate a small area of said hologram segments;
means for rotating said disk member about its axis so that each hologram segment on said disk member, when illuminated, produces a reconstructed point image which scans a circular arc;
first optical means disposed to intercept the recon-structed beam from one of said holograms and to reflect the intercepted beam to said scanning window to produce a first scanning segment; and second optical means disposed to intercept the recon-structed beam from another of said holograms and to reflect the intercepted beam to said scanning window to produce a second scanning segment intersecting the first scanning segment to produce a cross scanning pattern.
an elongated scanning window;
a disk member having a plurality of hologram segments recorded thereon, each of said hologram segments, when recon-structed, producing a point image, each of said reconstructed hologram segments producing different points in a plane which is parallel to the plane containing said hologram segments;
a collimated light source providing a beam of light directed to illuminate a small area of said hologram segments;
means for rotating said disk member about its axis so that each hologram segment on said disk member, when illuminated, produces a reconstructed point image which scans a circular arc;
first optical means disposed to intercept the recon-structed beam from one of said holograms and to reflect the intercepted beam to said scanning window to produce a first scanning segment; and second optical means disposed to intercept the recon-structed beam from another of said holograms and to reflect the intercepted beam to said scanning window to produce a second scanning segment intersecting the first scanning segment to produce a cross scanning pattern.
2. The scanning system according to Claim 1 additionally comprising third optical means disposed to intercept the recon-structed beam from a third of said plurality of holograms and to reflect the intercepted beam to said scanning window to produce a third scanning segment intersecting said first and said second scanning segments.
3. The scanning system of Claim 1 wherein said first and said second optical means each intercept a plurality of said reconstructed beams so that a plurality of cross scanning patter s is produced on said scanning window.
4. The scanning system of Claim 2 wherein said first and said second optical means each intercept a plurality of said reconstructed beams so that a plurality of cross scanning patterns is produced on said scanning window.
5. The scanning system of Claim 1 wherein said collimated light source is a laser.
6. The scanning system of Claim 1 wherein said plurality of hologram segments recorded on said disk member comprises one hologram segment for each of said scanning segments produced on said scanning window.
7. The scanning system of Claim 4 wherein the hologram segments to produce a complete scanning pattern on said scanning window are repeated a plurality of times on said disk member so that the entire scanning pattern is produced a plurality of times for each revolution of said disk member.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US05/644,679 US4026630A (en) | 1975-12-23 | 1975-12-23 | Scanning apparatus using holographic beam deflector |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1068141A true CA1068141A (en) | 1979-12-18 |
Family
ID=24585918
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA268,097A Expired CA1068141A (en) | 1975-12-23 | 1976-12-17 | Scanning apparatus using holographic beam deflector |
Country Status (6)
| Country | Link |
|---|---|
| US (1) | US4026630A (en) |
| JP (1) | JPS5280849A (en) |
| CA (1) | CA1068141A (en) |
| DE (1) | DE2657641A1 (en) |
| FR (1) | FR2336697A1 (en) |
| GB (1) | GB1534440A (en) |
Families Citing this family (31)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| FR2346735A1 (en) * | 1976-04-02 | 1977-10-28 | Ibm | STRAIGHT LINE OPTICAL SCAN DEVICE USING ROTARY HOLOGRAMS |
| JPS5614492Y2 (en) * | 1976-06-14 | 1981-04-06 | ||
| US4353615A (en) * | 1978-07-03 | 1982-10-12 | Xerox Corporation | Dynamic mounting for holographic spinners |
| JPS572018A (en) * | 1980-06-06 | 1982-01-07 | Fujitsu Ltd | Light scanner |
| JPS5744119A (en) * | 1980-06-25 | 1982-03-12 | Ibm | Holographic scanning device |
| US4753503A (en) * | 1981-02-25 | 1988-06-28 | Benson, Incorporated | Laser scanning system |
| US6182898B1 (en) | 1993-11-24 | 2001-02-06 | Metrologic Instruments, Inc. | Bar code scanner with intuitive head aiming and collimated scan volume |
| US5216232A (en) * | 1990-09-10 | 1993-06-01 | Metrologic Instruments, Inc. | Projection laser scanner producing a narrow scan volume |
| US6651890B2 (en) | 1990-09-10 | 2003-11-25 | Sung Ho Byun | Combination hand-held and counter-top omnidirectional scanner |
| US6257492B1 (en) | 1990-09-10 | 2001-07-10 | Peter Bressler | Combination hand-held and counter-top omni-directional scanner |
| US6098885A (en) | 1990-09-10 | 2000-08-08 | Metrologic Instruments | Countertop projection laser scanning system for omnidirectional scanning volume projected above a countertop surface of code symbols within a narrowly-confined scanning |
| US6286760B1 (en) | 1994-08-17 | 2001-09-11 | Metrologic Instruments, Inc. | Automatic hand-supportable laser projection scanner for omni-directional reading of bar code symbols within a narrowly confined scanning volume |
| US5796091A (en) * | 1993-11-24 | 1998-08-18 | Metrologic Instruments, Inc. | Automatic hand-supportable omnidirectional laser projection scanner with handle-controllable projection axis |
| US5844227A (en) * | 1993-11-24 | 1998-12-01 | Metrologic Instruments, Inc. | Automatic hand-supportable omnidirectional laser projection scanner with scan-head directed projection axis for intuitive hand-supported omnidirectional scanning of bar code symbols within a narrowly confined scanning volume extending thereabout |
| US5942743A (en) * | 1994-08-17 | 1999-08-24 | Metrologic Instruments, Inc. | Portable automatic hand-supportable omnidirectional laser projection scanner with power conserving control system |
| US6860427B1 (en) | 1993-11-24 | 2005-03-01 | Metrologic Instruments, Inc. | Automatic optical projection scanner for omni-directional reading of bar code symbols within a confined scanning volume |
| US6604684B1 (en) | 1993-11-24 | 2003-08-12 | Metrologic Instruments Inc. | Automatic optical projection scanner for omni-directional reading of bar code symbols within a confined scanning volume |
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| US6085978A (en) * | 1994-08-17 | 2000-07-11 | Metrologic Instruments, Inc. | Holographic laser scanners of modular construction and method and apparatus for designing and manufacturing the same |
| US6199759B1 (en) * | 1994-08-17 | 2001-03-13 | Metrologic Instruments, Inc. | Bar code symbol scanning system having a holographic laser scanning disc utilizing maximum light collection surface area thereof and having scanning facets with optimized light collection efficiency |
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| US6003772A (en) * | 1994-08-17 | 1999-12-21 | Metrologic Instruments, Inc. | Holographic laser scanning system employing holographic scanning disc having dual-fringe contrast regions for optimized laser beam scanning and light collection operations |
| US6758402B1 (en) * | 1994-08-17 | 2004-07-06 | Metrologic Instruments, Inc. | Bioptical holographic laser scanning system |
| US6006993A (en) * | 1994-08-17 | 1999-12-28 | Metrologic Instruments, Inc. | Holographic laser scanning system for carrying out laser beam scanning operations with improved scan angle multiplication efficiency and carrying out light collection operations with improved light collection efficiency |
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| US6629640B2 (en) * | 1995-12-18 | 2003-10-07 | Metrologic Instruments, Inc. | Holographic laser scanning method and system employing visible scanning-zone indicators identifying a three-dimensional omni-directional laser scanning volume for package transport navigation |
| US6619550B1 (en) | 1995-12-18 | 2003-09-16 | Metrologic Instruments, Inc. | Automated tunnel-type laser scanning system employing corner-projected orthogonal laser scanning patterns for enhanced reading of ladder and picket fence oriented bar codes on packages moving therethrough |
| KR100346687B1 (en) * | 1998-10-23 | 2002-10-30 | 삼성전자 주식회사 | Multi laser scanning unit |
| JP4330762B2 (en) | 2000-04-21 | 2009-09-16 | 富士フイルム株式会社 | Multi-beam exposure system |
| WO2006121455A1 (en) | 2005-05-10 | 2006-11-16 | The Salk Institute For Biological Studies | Dynamic signal processing |
Family Cites Families (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3614193A (en) * | 1970-04-15 | 1971-10-19 | Columbia Broadcasting Systems | Light scanning system utilizing diffraction optics |
| FR2096982B1 (en) * | 1970-07-23 | 1974-06-14 | Jobin & Yvon | |
| US3728677A (en) * | 1971-05-10 | 1973-04-17 | Stanford Research Inst | Rotation-independent reading of rectangular insignia |
| US3703724A (en) * | 1971-07-22 | 1972-11-21 | Kms Ind Inc | Recorder with zone plate scanner |
| US3795768A (en) * | 1971-12-15 | 1974-03-05 | Communications Satellite Corp | Holographic image scanner/recorder system |
| JPS5322848B2 (en) * | 1971-12-31 | 1978-07-11 | ||
| US3940202A (en) * | 1971-12-31 | 1976-02-24 | Matsushita Electric Industrial Co., Ltd. | Light beam deflection system |
| DE2214386C3 (en) * | 1972-03-24 | 1978-10-26 | Erwin Sick Gmbh Optik-Elektronik, 7808 Waldkirch | Method for reading strip-shaped information carriers |
| US3916158A (en) * | 1974-01-21 | 1975-10-28 | Pitney Bowes Inc | Optical scanner and method for producing a scanning pattern |
-
1975
- 1975-12-23 US US05/644,679 patent/US4026630A/en not_active Expired - Lifetime
-
1976
- 1976-10-11 GB GB42208/76A patent/GB1534440A/en not_active Expired
- 1976-11-08 FR FR7634524A patent/FR2336697A1/en active Granted
- 1976-12-03 JP JP51144862A patent/JPS5280849A/en active Pending
- 1976-12-17 CA CA268,097A patent/CA1068141A/en not_active Expired
- 1976-12-20 DE DE19762657641 patent/DE2657641A1/en active Pending
Also Published As
| Publication number | Publication date |
|---|---|
| US4026630A (en) | 1977-05-31 |
| DE2657641A1 (en) | 1977-07-14 |
| JPS5280849A (en) | 1977-07-06 |
| FR2336697A1 (en) | 1977-07-22 |
| GB1534440A (en) | 1978-12-06 |
| FR2336697B1 (en) | 1978-06-23 |
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