Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B07—SEPARATING SOLIDS FROM SOLIDS; SORTING
  • B07C—POSTAL SORTING; SORTING INDIVIDUAL ARTICLES, OR BULK MATERIAL FIT TO BE SORTED PIECE-MEAL, e.g. BY PICKING
  • B07C3/00—Sorting according to destination
  • B07C3/10—Apparatus characterised by the means used for detection ofthe destination
  • B07C3/14—Apparatus characterised by the means used for detection ofthe destination using light-responsive detecting means

Definitions

• Real-time extraction of the desired portions of the video data is another technique for reducing the memory storage requirement.
• real-time data extraction is a very effective technique because most of the video data created by the continuously running scanner is a useless image of the conveyor and the non-indicia bearing areas of the parcels moving along the conveyor; only a small percentage of the data includes the destination addresses of the parcels to be shipped. Therefore, extracting only small portions of the video data, such as relatively small areas covering the destination addresses, greatly reduces the memory storage requirement and speeds up the character recognition process.
• Kizu et al. U.S. Patent No. 4,516,265
• the system includes a low resolution prescanner that coarsely scans the surface of the envelope.
• the position of the destination address block is determined from the coarse scan, and the coordinates of the destination address block with respect to the leading edge of the envelope are then passed to a second, high-resolution camera system.
• the second camera system stores an image of the destination address block by first detecting the leading edge of the envelope.
• a scanner located downstream of the illumination source captures an image of a region that is defined with respect to the spot defined by the illumination source.
• the optical guide may include a moving light, such as a narrow-beam spot light, that is projected onto the conveyor, and that travels at the same speed as the conveyor. Positioning a parcel on the conveyor so that the spot light is located in the center of the city and state address lines of the destination address allows a scanner to efficiently capture an image of the destination address for processing by a character recognition reader.
• the moving-light indicia reader system includes a conveyor for transporting a parcel from an upstream location of the conveyor to a downstream location of the conveyor.
• a sensor assembly 28, including a height sensor and reflectivity sensor, my be located toward the downstream end of the illumination source 24.
• a communication link 30 functionally connects the sensor assembly 28 to a scanner 32 that is located downstream from the sensor assembly 28.
• the scanner 32 is focused in response to height data from the height sensor, and the gain of the scanner 32 is adjusted in response to reflectivity data from the reflectivity sensor, so that the scanner 32 generates a clear image of the top of the parcel 14 as the parcel passes beneath the scanner 32.
• the scanner 32 is preferably positioned so that the scan line 34 is oriented across a portion of the conveyor 12 that is aligned with the area 26 in the cross-machine direction.
• a belt encoder 36 measures the displacement of the conveyor 12.
• the area 26 is typically a rectangular strip that is significantly narrower than the conveyor 12, sufficiently long to allow an operator to easily position a parcel on the conveyor 12 using the optical guide, and approximately in the center of the conveyor 12.
• the area 26 may be approximately 4 inches (10 cm) in the cross-machine direction and approximately 12 (30 cm) to 36 inches (91 cm) in the direction of conveyor travel.
• projected illumination rather than an area painted on the conveyor 12, allows the operator to view the area 26 defined by the illumination source 24 directly on the top of the parcel 14. Thus, there is no displacement between the area 26 and the top of the parcel 14 that could cause parallax-related alignment errors with tall parcels.
• the belt encoder 36 is a standard belt-driven, opto-mechanical encoder that provides a signal indicating the linear displacement of the conveyor 12.
• the CCD array of the scanner 32 is cycled in response to the signal from the belt encoder 36 to generate a series of analog images of the scan line 34 that are transmitted to an analog-to-digital converter within the scanner 32.
• the analog-to-digital converter of the scanner 32 uses a standard thresholding or similar process to convert the analog signal produced by the CCD array of the scanner 32 into an eight-bit digital video signal that is transmitted via the communication link 44 to the character recognition system 40, which is operable for storing the video data in the computer memory 42 for subsequent processing.
• the scanner 32 is preferably a monochrome, 4,096 pixel line-scan type CCD array such as one using a Thompson TH7833A CCD chip.
• the resolution of the image created by the scanner 32 is approximately 256 pixels or "dots" per inch (DPI) (101 dots per cm) across the field of view of the scanner 32.
• the belt encoder 36 preferably triggers the CCD array of the scanner 32 at a rate of approximately 256 cycles per inch (101 cycles per cm) so that the resolution of the image created by the scanner 32 is approximately 256 pixels or "dots" per inch (DPI) (101 dots per cm) in the direction of conveyor travel.
• a digital image with a correct aspect ratio may be generated by the scanner 32 and stored in the computer memory 42 of the character recognition system 40 by synchronizing the cycling rate of the scanner 32 with the linear speed of the conveyor 12. See, for example, Shah et al., U.S. Patent No. 5,291,564, which is incorporated by reference.
• the conveyor 12 may be approximately 24 inches (61 cm) wide and travel at linear speeds up to 20 inches per second or 100 feet per minute (51 cm per second or 30 meters per minute) or more.
• the scanner 32 is preferably mounted to have an optical path of approximately 120 inches (304 cm) to the conveyor 12 with a 16 inch (41 cm) field of view at the conveyor 12.
• the optically- guided indicia reader system 10 reduces the amount of video data that must be stored in the computer memory 42 of the character recognition system 40.
• the use of projected illumination allows the operator to view the area 30 defined by the illumination source 24 directly on the top of the parcel 14. Thus, there is no displacement between the area 26 and the top of the parcel 14 that could cause parallax-related alignment errors with tall parcels.
• the optically-guided indicia reader system 10 allows the angle of the field of view of the scanner 32 to be relatively narrow so that the scanner 32 generates a sharp image of the top of the parcel 14.
• the moving-light indicia reader system 200 includes indicia to be read by the moving-light indicia reader system 200, such as a destination address 220.
• the parcel 214 may include other indicia, such as the return address, that the moving-light indicia reader system 200 preferably avoids reading.
• the moving-light indicia reader system 200 includes a moving-light illumination source 224 that includes a plurality of discrete illumination sources 226a through 226n, such as light- emitting diodes (LEDs), that project columnar beams of light represented by the beam 228.
• LEDs light- emitting diodes
• the height data from the sensor assembly 232 indicates the presence of a parcel 214 in association with a spot 230 so that an image of a region 250 is only stored in the computer memory 242 when a parcel 214 is present in association with a spot 230 defined by the moving-light illumination source 224.
• an operator positions the parcel 214 on the conveyor 212 so that the spot 230 defined by the moving-light illumination source 224 is centered with respect to the destination address 220 on the parcel 214.
• FIG. 2A illustrates the parcel 214 positioned so that the spot 230 defined by the first discrete illumination source 226a is centered with respect to the destination address 220.
• FIGS. 2D and 2E illustrate the scanning of the parcel 214 by the scanner 236, which includes a CCD array that repeatedly generates an image of a scan line 252 to generate a video signal.
• the operation of the scanner 236 and the processing module 241 of the character recognition system 240 are synchronized with the movement of the spot 230 so as to store in the computer memory 242 an image of the region 250, which is defined with respect to the spot 230.
• the processing module 241 causes the computer memory 242 of the character recognition system 240 to begin storing the video data generated by the scanner 236.
• the video data generated by the scanner 236 continues to be stored until the region 250 passes the scan line 252, which happens shortly before the parcel 214 is in the position shown in FIG. 2E.
• the spot 230 may have virtually any size or configuration, and that multiple spots may be used to identify indicia on the parcel, such as four spots defining the corners of a rectangular region to be imaged.
• the spot 230 may be defined by an illuminated area, or by an illuminated border, or by two illuminated spaced- apart parallel lines, etc.
• the spot 230 could be configured to correspond to the width of the region 250 to be stored in the computer memory 224. This would assist an operator in orienting a parcel 214 so that the destination address 220 can be effectively scanned by the indicia reader system 200 as configured.
• the character recognition system 240 is operative to selectively trigger the storage of an image in the computer memory 242. Triggering the storage of the image of the region 250 in the computer memory 242 may be accomplished in several different ways.
• the scanner 236 may be toggled on and off by the processing module 241 in response to the signal from the belt encoder 238.
• the scanner 236 may run continuously, and the processing module 241 may respond to the signal from the belt encoder 238 by latching a control line to an input buffer of the character recognition system 240.
• the signal from the belt encoder 238 may be used as an input to a software- based algorithm running on the processing module 241, which triggers the storage of video data from the scanner 236 in the computer memory 242.
• Many other means known to those skilled in the art may equivalently be employed to operate the character recognition system 240 and the scanner 236 so as to store an image of the region 250 in the computer memory 242.
• the belt encoder 238 is a standard belt-driven, opto-mechanical encoder that provides a signal indicating the linear displacement of the conveyor 212.
• the CCD array of the scanner 236 is cycled in response to the signal from the belt encoder 238 to generate a series of analog images of the scan line 252 that are transmitted to an analog-to-digital converter within the scanner 236.
• the analog-to-digital converter of the scanner 236 uses a standard thresholding or similar process to convert the analog signal produced by the CCD array of the scanner 236 into an eight-bit digital video signal that is transmitted via the communication link 246 to the character recognition system 240, which is operable for storing the video data in the computer memory 242 for subsequent processing.
• the scanner 236 is preferably a monochrome, 4,096 pixel line-scan type CCD array such as one using a Thompson TH7833A CCD chip.
• the resolution of the image created by the scanner 232 is approximately 256 pixels or "dots" per inch (DPI) (101 dots per cm) across the field of view of the scanner 236.
• the belt encoder 238 preferably triggers the CCD array of the scanner 236 at a rate of approximately 256 cycles per inch (2.54 cm) so that the resolution of the image created by the scanner 232 is approximately 256 pixels or "dots" per inch (DPI) (101 dots per cm) in the direction of conveyor travel.
• a digital image with a correct aspect ratio may be generated by the scanner 236 and stored in the computer memory 242 of the character recognition system 240 by synchronizing the cycling rate of the scanner 236 with the linear speed of the conveyor 212.
• the conveyor 212 may be approximately 24 inches (61 cm) wide and travel at linear speeds up to 20 inches per second or 100 feet per minute (51 cm per second or 30 meters per minute) or more.
• the moving-light illumination source 224 is preferably positioned approximately 18 inches (46 cm) above conveyor 212 and defines a spot 230 that is approximately 1 inch (2.5 cm) wide and 1 inch (2.5 cm) long at the conveyor 212.
• the moving-light illumination source 224 may be operated so that successive moving spots 230 are spaced virtually any distance apart.
• acceptable performance is experienced when the moving-light indicia reader system 200 is operated with the conveyor 212 traveling at 50 feet per minute (25 cm per second or 15 meters per minute), and with the moving spots 230 spaced 22 inches (56 cm) apart, which allows the moving-light indicia reader system 200 to handle approximately 1,636 parcels per hour if the operator places a parcel under each moving spot.
• the scanner 236 is preferably mounted to have an optical path of approximately 120 inches (305 cm) to the conveyor 212, with a 16 inch (41 cm) field of view at the conveyor 212. To save space, the scanner 236 is positioned approximately 30 inches (76 cm) above the center of conveyer 212 and is pointed towards a complex of mirrors (not shown) that increases the optical path from the scanner 236 to the conveyor 212 to approximately 120 inches (305 cm). These parameters may be varied somewhat without unduly affecting the performance of the disclosed embodiment of the present invention.
• the moving-light illumination source 224 should be long enough to allow an operator to position the parcel 214 on the conveyor 212 while the spot 230 travels from the upstream end to the downstream end of the moving-light illumination source
• a moving-light illumination source 224 having a length of 36 inches (91 cm) and 72 LEDs spaced 1/2 inch (1.3 cm) apart is appropriate for the conveyor 212 traveling at
• the LEDs 226a-n of the moving-light illumination source 224 may be any of a variety of commercially available LEDs, such as a model AND190W0P manufactured by
• the sensor assembly 232 may include any of a variety of commercially available height sensors, such as a model NR-40 manufactured by Innova Labs, Inc.
• FIG. 4 is a diagram of a multi-conveyor indicia reader system 400 that includes a plurality of moving-light indicia reader systems 210a through 210n, which are virtually identical to those described above with respect to FIGS. 2A-E.
• Each of the moving-light indicia reader systems 210a through 210n are synchronized by, and provide their video data to, a single character recognition system 240.
• the character recognition system 240 synchronizes the moving spots 230a through 230n of the moving-light indicia reader systems 210a through 210n so as to time-division multiplex the storage of the regions 250a through 250n from the several scanners 236a through 236n.
• the spots 230a through 230n are spaced relative to each other so that only one of the regions 250a through 250n captured by the scanners 236a through 236n needs to be stored in the computer memory 242 of the character recognition system 240 at any time.
• the moving-light indicia reader system 400 allows the video data stored in the computer memory 242 of the character recognition system 240 to be reduced to a standard-sized region that is only large enough to capture the text of the destination addresses 220a-220n on the various parcels carried on the conveyors 212a- 212n.
• the use of projected illumination allows the operator to view the spot 230a-230n defined by each moving-light illumination source 224a-224n directly on the top of the parcels 214a-214n.
• the moving-light indicia reader system 400 allows the angle of the field of view of the scanners 236a-236n to be relatively narrow so that the scanners generates sharp images of the top of the parcels 214a-214n.

Landscapes

• Character Input (AREA)
• Sorting Of Articles (AREA)
• Optical Communication System (AREA)
• Aerials With Secondary Devices (AREA)
• Holo Graphy (AREA)
• Control Of Driving Devices And Active Controlling Of Vehicle (AREA)
• Control Of Temperature (AREA)
• Sowing (AREA)
• Traffic Control Systems (AREA)
• Control Of Position, Course, Altitude, Or Attitude Of Moving Bodies (AREA)
• Mechanical Optical Scanning Systems (AREA)

Priority Applications (5)

Applications Claiming Priority (4)

Publications (1)

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Family Applications (1)

Country Status (8)

Cited By (6)

Families Citing this family (7)

Citations (4)

• 1998
  • 1998-01-23 AT AT98902706T patent/ATE267649T1/de not_active IP Right Cessation
  • 1998-01-23 AT AT03020263T patent/ATE338589T1/de not_active IP Right Cessation
  • 1998-01-23 DE DE69835840T patent/DE69835840T2/de not_active Expired - Lifetime
  • 1998-01-23 WO PCT/US1998/001366 patent/WO1998032545A1/en active IP Right Grant
  • 1998-01-23 CA CA002271063A patent/CA2271063C/en not_active Expired - Fee Related
  • 1998-01-23 EP EP03020263A patent/EP1371424B1/de not_active Expired - Lifetime
  • 1998-01-23 DE DE69824149T patent/DE69824149T2/de not_active Expired - Lifetime
  • 1998-01-23 JP JP53216498A patent/JP3476836B2/ja not_active Expired - Fee Related
  • 1998-01-23 EP EP98902706A patent/EP0954387B1/de not_active Expired - Lifetime
  • 1998-01-23 DK DK98902706T patent/DK0954387T3/da active
  • 1998-01-23 ES ES98902706T patent/ES2221148T3/es not_active Expired - Lifetime
  • 1998-01-23 ES ES03020263T patent/ES2271447T3/es not_active Expired - Lifetime

Patent Citations (4)

Non-Patent Citations (1)

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