USRE37017E1 - Laser-beam bar code reader - Google Patents
Laser-beam bar code reader Download PDFInfo
- Publication number
- USRE37017E1 USRE37017E1 US08/921,045 US92104597A USRE37017E US RE37017 E1 USRE37017 E1 US RE37017E1 US 92104597 A US92104597 A US 92104597A US RE37017 E USRE37017 E US RE37017E
- Authority
- US
- United States
- Prior art keywords
- laser
- beams
- read area
- sources
- bar code
- 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 - Lifetime
Links
- 230000003287 optical effect Effects 0.000 claims abstract description 47
- 125000004122 cyclic group Chemical group 0.000 claims abstract description 3
- 230000008859 change Effects 0.000 claims description 9
- 230000000712 assembly Effects 0.000 claims description 7
- 238000000429 assembly Methods 0.000 claims description 7
- 238000001514 detection method Methods 0.000 claims 7
- 230000003213 activating effect Effects 0.000 claims 1
- 230000004913 activation Effects 0.000 description 2
- 238000000034 method Methods 0.000 description 2
- 239000012141 concentrate Substances 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000000737 periodic effect Effects 0.000 description 1
- 230000002093 peripheral effect Effects 0.000 description 1
- 230000001360 synchronised effect Effects 0.000 description 1
- 230000007704 transition Effects 0.000 description 1
Images
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
- 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
- G06K7/10554—Moving beam scanning
- G06K7/10564—Light sources
- G06K7/10574—Multiple sources
-
- 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
- G06K7/10792—Special measures in relation to the object to be scanned
- G06K7/10801—Multidistance reading
- G06K7/10811—Focalisation
-
- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06K—GRAPHICAL DATA READING; PRESENTATION OF DATA; RECORD CARRIERS; HANDLING RECORD CARRIERS
- G06K2207/00—Other aspects
- G06K2207/1018—Source control
Definitions
- the present invention relates to a bar code reader which uses a laser beam.
- the laser beam is first focused by means of an appropriate optical system and then deflected by means of a polygonal rotor fitted with mirrors, which is rotated rapidly so as to perform a periodic scanning of the region in which the bar code is located.
- the image of the laser source in the focusing point must remain within very precise limits which are in practice set by the thickness of the bars of the code.
- the reading of the code would in fact be erroneous if the wavefront of the beam had such a diameter as to cover more than two bars.
- the emitted light beam has a spherical divergent wavefront.
- FIG. 1 schematically illustrates the method of operation of such a known focusing system.
- the reference numeral 1 indicates the laser source and the numeral 2 indicates the lens which concentrates the light beam in a point P which has a distance d from the lens. Once the point P has been passed, the light beam diverges again, so that its diameter remains within the limits required for practical use only in a rather narrow region 2 s around the focusing point P.
- the diameter of the laser beam is greater than the thickness of the bars of the code, and accordingly the light signal received by the reader does not allow a correct reconstruction of the alternation of the light and dark bars of the code.
- the narrowness of the focusing region furthermore reduces the scanning area of the laser beam, and ultimately the read area is reduced, such read area being shown by FIGS. 2 and 3, which illustrate two read areas A 1 and A 2 which have an equal width at a different distance from the laser source, depending on the location of the focusing point of the laser beam.
- the technical aim of the present invention is therefore to provide a bar code reader which can operate on a significantly larger read area and does not have the disadvantages described above in conventional readers.
- FIG. 1 illustrates the method of operation of a conventional focusing system
- FIGS. 2 - 3 illustrate two read areas A 1 and A 2 , respectively, achieved by the above conventional focusing system
- FIG. 4 is a block diagram of the reader according to the present invention.
- FIG. 5 charts the time sequence of the signals at the output of some blocks
- the numerals 3 and 4 indicate two laser beam sources, for example constituted by solid-state diodes of the type commercially known by the code TOLD 9211 and manufactured by the Toshiba company (Japan).
- the beams at the output of the diodes are mutually perpendicular and are focused at different distances by respective optical assemblies 5 and 6 .
- the beam arriving from the optical assembly 5 is sent through a semi-reflecting mirror 7 which is arranged at the intersection point of the beams and reflects the beam arriving from the assembly 6 .
- the angles of incidence of the laser beams arriving from the optical assemblies 5 , 6 with respect to the mirror 7 are chosen so as to generate a unidirectional beam 8 which is directed, through a hole of an optical receiver assembly 9 , onto a polygonal rotor 10 .
- the polygonal rotor 10 comprises a plurality of peripheral mirrors 11 which, by means of the rotation of the rotor 10 , scan a preset read area. As shown in FIG. 6 the read area includes the two areas A 1 and A 2 which are alternately scanned by the laser beam sources. The intersection area between A 1 and A 2 which is scanned by both sources is represented in double hatched lines.
- the beam reflected from the read area is deflected by said rotor and by the receiver assembly 9 toward an optical return system 12 and then to the input of a video amplifier 13 which provides to a microprocessor-based decoding unit 14 a signal which corresponds to the image of the area scanned by the laser beam.
- a rotation sensor 15 is operatively associated with the rotor 10 and provides, for each mirror 11 which passes in front of it, a signal which actuates a control device 16 which can alternately activate the power supplies 17 , 18 of the two diodes 3 and 4 .
- the signals supplied by the sensor 15 occur in the form of pulses A and which are emitted at regular intervals in the period of transition between one mirror and the subsequent one during the rotation of the rotor 10 .
- the control device 16 alternatively activates, upon each pulse A arriving from the sensor 15 , the power supplies 17 , 18 of the two laser diodes 3 and 4 if the scanning of the read area has not detected the presence of a code. Vice versa, if the scanning determines the presence of a code, the control device 16 keeps active the power supply of the diode which has produced the laser beam which has identified the code.
- the power supply 17 receives a level “1” signal, with the corresponding switching on of the diode 3 for the period T, the power supply 18 receives a level “0” signal which keeps the diode 4 switched off for the same period T.
- the duration T 1 of the pulses is used to complete the switching of the diodes, and no scanning of the read area is performed during this time.
- the read area is scanned by the laser beam emitted by the diode 3 , 4 which is connected to the power supply which receives, at that instant, the level “1” signal from the control device; the other power supply is blocked by the level “0” signal.
- the signal sent to the power supply 17 is indicated by B and the one sent to the power supply 18 is indicated by C.
- the alternation of the signals B and C is controlled by the signal D at the output of the decoding unit 14 , which can assume two levels, “1” and “0”, depending on whether the presence of a bar code in the read area is detected or not.
- the rotor 10 by means of the sensor 15 , synchronized with the power supplies 17 , 18 , so that each mirror of the rotor reflects onto the region to be scanned the laser beam emitted by the power supply which has received the level “1” signal at that instant. Since the laser beams emitted by the diodes 3 , 4 are focused on two different areas A 1 and A 2 (see FIG. 6 ), the alternation in emission also produces the alternation in the scanning of the two regions A 1 and A 2 which compose the read area.
- the signal B of the power supply 17 is at level “0” and therefore the diode 3 is off, whereas the signal C of the power supply is at level “1” and therefore the diode 4 is on, so that the region A 2 , on which the beam emitted by the diode 4 is focused, is scanned.
- the image of the scanning area is reflected in each instance by the optical assembly 9 and sent to the decoding unit 14 , and when said decoding unit identifies a bar code E therein, the output signal D changes level, thus indicating, even before the code is decoded, the presence of a probable useful data item.
- the change in level of the signal D is interpreted by the control device 16 as a command for locking the power supplies 17 , 18 in the state in which they are at that instant.
- the change in level from “0” to “1” of the signal D causes the locking of the signal B at level “0” and of the signal C at level “1”, so that the subsequent scans are performed by the same laser beam, in this case by the beam emitted by the diode 4 , which is focused in the region A 2 explored thereby, where the presence of the code has been detected.
- the signal D returns to level “0”, restoring the alternating scan.
- the described reader perfectly achieves the intended aim.
- the cyclic scanning of the regions which compose the read area with laser beams, each of which is focused on a respective region allows a high read probability.
- the number of laser sources can be higher than two, so as to include a larger read area.
- a further variated embodiment provides the driving of the power supplies on the part of an external sensor 19 which can detect the presence of the code.
- the signal D is no longer necessary, since switching from one power supply to the other is controlled by the external sensor.
- Another possibility provides the continuous switching of the reading from region A 1 to region A 2 , regardless of the presence of the code. In this case a simpler electronic circuitry is obtained, but half of the scans cannot be used since they are performed on an area in which the code is not present.
Abstract
Description
Claims (22)
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US08/921,045 USRE37017E1 (en) | 1990-10-09 | 1997-08-29 | Laser-beam bar code reader |
Applications Claiming Priority (5)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
IT00367990A IT1242584B (en) | 1990-10-09 | 1990-10-09 | LASER BEAM BAR CODE READER. |
IT3679/90 | 1990-10-09 | ||
US77271291A | 1991-10-07 | 1991-10-07 | |
US08/191,241 US5446267A (en) | 1990-10-09 | 1994-02-03 | Laer-beam bar code reader |
US08/921,045 USRE37017E1 (en) | 1990-10-09 | 1997-08-29 | Laser-beam bar code reader |
Related Parent Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US08/191,241 Reissue US5446267A (en) | 1990-10-09 | 1994-02-03 | Laer-beam bar code reader |
Publications (1)
Publication Number | Publication Date |
---|---|
USRE37017E1 true USRE37017E1 (en) | 2001-01-16 |
Family
ID=11111349
Family Applications (2)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US08/191,241 Expired - Lifetime US5446267A (en) | 1990-10-09 | 1994-02-03 | Laer-beam bar code reader |
US08/921,045 Expired - Lifetime USRE37017E1 (en) | 1990-10-09 | 1997-08-29 | Laser-beam bar code reader |
Family Applications Before (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US08/191,241 Expired - Lifetime US5446267A (en) | 1990-10-09 | 1994-02-03 | Laer-beam bar code reader |
Country Status (4)
Country | Link |
---|---|
US (2) | US5446267A (en) |
EP (1) | EP0480348B1 (en) |
DE (1) | DE69124052T2 (en) |
IT (1) | IT1242584B (en) |
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US9530037B1 (en) | 2015-07-20 | 2016-12-27 | Datalogic ADC, Inc. | Toggling activation of lasers in scanner systems |
USD802593S1 (en) * | 2015-08-28 | 2017-11-14 | Hand Held Products, Inc. | Scanner |
Families Citing this family (14)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US5258605A (en) * | 1990-03-13 | 1993-11-02 | Symbol Technologies, Inc. | Scan generators for bar code reader using linear array of lasers |
CA2056272C (en) * | 1991-06-14 | 2001-10-16 | Patrick Salatto, Jr. | Combined range laser scanner |
DE4227003C1 (en) * | 1992-08-14 | 1993-11-25 | Leuze Electronic Gmbh & Co | Optical scanner for reading bar=code symbols - use two continuous light beams directed by mirror and rotating polygon mirror onto surface of bar=code |
IT1264733B1 (en) * | 1993-11-04 | 1996-10-04 | Datalogic Spa | LASER READING DEVICE OR SCANNER FOR READING CHARACTERS HAVING A DIFFERENT DEGREE OF REFLECTENCE, IN PARTICULAR OF CODES A |
GB2319103B (en) * | 1996-11-05 | 2000-05-03 | Psc Inc | Combination range laser scanner utilizing periodic range switching |
NL1006454C2 (en) * | 1997-07-02 | 1999-02-15 | Scantech Bv | Device and method for reading a code on an article. |
ATE201107T1 (en) | 1997-12-16 | 2001-05-15 | Datalogic Spa | OPTICAL CODE SCAN WITH LASER BEAMS MOVING ALONG TWO DIFFERENT OPTICAL PATHS |
US6354501B1 (en) * | 1998-11-18 | 2002-03-12 | Crossoff Incorporated | Composite authentication mark and system and method for reading the same |
US6536672B1 (en) | 1998-11-18 | 2003-03-25 | Dna Technologies, Inc. | Product authentication system and method |
US6137967A (en) | 1999-09-13 | 2000-10-24 | Oce Printing Systems Gmbh | Document verification and tracking system for printed material |
DE60223162T2 (en) * | 2002-12-31 | 2008-08-14 | Datalogic Scanning Group S.R.L. | Method for reading graphic patterns and capturing his image |
DE10331467A1 (en) * | 2003-07-11 | 2005-02-10 | Sick Ag | Device for optically scanning objects, in particular markings |
US8316068B2 (en) | 2004-06-04 | 2012-11-20 | Telefonaktiebolaget Lm Ericsson (Publ) | Memory compression |
US8459557B2 (en) * | 2011-03-10 | 2013-06-11 | Metrologic Instruments, Inc. | Dual laser scanning code symbol reading system employing automatic object presence detector for automatic laser source selection |
Citations (8)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4315245A (en) * | 1978-04-05 | 1982-02-09 | Sumitomo Electric Industries, Ltd. | Optical information reading device |
DE3311352C1 (en) * | 1983-03-29 | 1984-03-15 | Ingenieurbüro Rudolf Weber KG, 6100 Darmstadt | Detector for recording marks |
US4508422A (en) * | 1982-03-03 | 1985-04-02 | Pharos Ab | Optical scanning system |
US4704519A (en) * | 1986-06-19 | 1987-11-03 | Emhart Industries, Inc. | Selective code reader |
EP0360250A2 (en) * | 1988-09-20 | 1990-03-28 | Kabushiki Kaisha TEC | Optical reading apparatus |
US5042619A (en) * | 1988-09-21 | 1991-08-27 | Tokyo Electric Co., Ltd. | Commodity data reading apparatus |
US5552590A (en) * | 1992-09-08 | 1996-09-03 | Nippondenso Co., Ltd. | Optical information reading apparatus having means for judging laser deterioration |
USRE36251E (en) * | 1993-11-04 | 1999-07-13 | Datalogic S.P.A. | Laser bar code reader measuring phase of the pulse laser to determine the distance |
-
1990
- 1990-10-09 IT IT00367990A patent/IT1242584B/en active IP Right Grant
-
1991
- 1991-10-07 EP EP91117038A patent/EP0480348B1/en not_active Expired - Lifetime
- 1991-10-07 DE DE69124052T patent/DE69124052T2/en not_active Expired - Lifetime
-
1994
- 1994-02-03 US US08/191,241 patent/US5446267A/en not_active Expired - Lifetime
-
1997
- 1997-08-29 US US08/921,045 patent/USRE37017E1/en not_active Expired - Lifetime
Patent Citations (8)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4315245A (en) * | 1978-04-05 | 1982-02-09 | Sumitomo Electric Industries, Ltd. | Optical information reading device |
US4508422A (en) * | 1982-03-03 | 1985-04-02 | Pharos Ab | Optical scanning system |
DE3311352C1 (en) * | 1983-03-29 | 1984-03-15 | Ingenieurbüro Rudolf Weber KG, 6100 Darmstadt | Detector for recording marks |
US4704519A (en) * | 1986-06-19 | 1987-11-03 | Emhart Industries, Inc. | Selective code reader |
EP0360250A2 (en) * | 1988-09-20 | 1990-03-28 | Kabushiki Kaisha TEC | Optical reading apparatus |
US5042619A (en) * | 1988-09-21 | 1991-08-27 | Tokyo Electric Co., Ltd. | Commodity data reading apparatus |
US5552590A (en) * | 1992-09-08 | 1996-09-03 | Nippondenso Co., Ltd. | Optical information reading apparatus having means for judging laser deterioration |
USRE36251E (en) * | 1993-11-04 | 1999-07-13 | Datalogic S.P.A. | Laser bar code reader measuring phase of the pulse laser to determine the distance |
Cited By (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US9530037B1 (en) | 2015-07-20 | 2016-12-27 | Datalogic ADC, Inc. | Toggling activation of lasers in scanner systems |
US10275623B2 (en) | 2015-07-20 | 2019-04-30 | Datalogic Usa, Inc. | Toggling activation of lasers in scanner systems |
USD802593S1 (en) * | 2015-08-28 | 2017-11-14 | Hand Held Products, Inc. | Scanner |
USD823307S1 (en) * | 2015-08-28 | 2018-07-17 | Hand Held Products, Inc. | Scanner |
Also Published As
Publication number | Publication date |
---|---|
IT9003679A1 (en) | 1992-04-09 |
EP0480348A1 (en) | 1992-04-15 |
US5446267A (en) | 1995-08-29 |
IT9003679A0 (en) | 1990-10-09 |
EP0480348B1 (en) | 1997-01-08 |
DE69124052D1 (en) | 1997-02-20 |
DE69124052T2 (en) | 1997-05-22 |
IT1242584B (en) | 1994-05-16 |
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