WO2008039963B1 - Laser power control arrangements in electro-optical readers - Google Patents

Laser power control arrangements in electro-optical readers

Info

Publication number
WO2008039963B1
WO2008039963B1 PCT/US2007/079815 US2007079815W WO2008039963B1 WO 2008039963 B1 WO2008039963 B1 WO 2008039963B1 US 2007079815 W US2007079815 W US 2007079815W WO 2008039963 B1 WO2008039963 B1 WO 2008039963B1
Authority
WO
WIPO (PCT)
Prior art keywords
laser
reader
laser beam
photodiode
focusing lens
Prior art date
Application number
PCT/US2007/079815
Other languages
French (fr)
Other versions
WO2008039963A3 (en
WO2008039963A2 (en
Inventor
Vladimir Gurevich
Heng Zhang
David Tsi-Shi
Original Assignee
Symbol Technologies Inc
Vladimir Gurevich
Heng Zhang
David Tsi-Shi
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Symbol Technologies Inc, Vladimir Gurevich, Heng Zhang, David Tsi-Shi filed Critical Symbol Technologies Inc
Publication of WO2008039963A2 publication Critical patent/WO2008039963A2/en
Publication of WO2008039963A3 publication Critical patent/WO2008039963A3/en
Publication of WO2008039963B1 publication Critical patent/WO2008039963B1/en

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
    • G06K7/10554—Moving beam scanning
    • G06K7/10564—Light sources
    • G06K7/10584—Source control

Abstract

Laser power control arrangements interrupt power to a laser used in electro-optical readers upon detection of operating conditions not conforming to preestablished standards, and adjust power to enhance reader performance without violating prevalent safety standards. Dual monitors are used to independently monitor the output power of the laser.

Claims

AMENDED CLAIMS received by the International Bureau on 22 July 2008 (22.07.2008)
1. A laser power control arrangement in an electro-optical reader for reading indicia, comprising: a) a diode laser for generating a laser beam having an output power; b) a pair of monitors for independently monitoring an operating condition of the reader, each monitor being operative for independently detecting reader malfunction when the operating condition differs from a preestablished condition, wherein one of the monitors is a monitor photodiode, and wherein the other of the monitors is an auxiliary photodiode; c) a controller for controlling the output power of the laser beam upon detection of the reader malfunction; d) a focusing lens for focusing the laser beam; e) a support has a hole between the laser diode and the focusing lens, wherein the laser diode and the focusing lens are mounted adjacent each other on the support; and e) a printed circuit board on which the auxiliary photodiode is mounted at a location juxtaposed with the hole of the support.
7. The arrangement of claim 1, and an enclosure surrounding the auxiliary photodiode to prevent stray light from entering the auxiliary photodiode.
8. The arrangement of claim 1, wherein a fraction of the laser beam is reflected by the focusing lens through the hole.
12. A laser power control method in an electro-optical reader for reading indicia, comprising the steps of: a) generating a laser beam having an output power with a laser diode; b) independently monitoring an operating condition of the reader with dual monitors, each monitor being operative for independently detecting reader malfunction when the operating condition differs from a preestablished condition, and wherein the monitoring step is performed by a monitor photodiode and an auxiliary photodiode; and c) controlling the output power of the laser beam upon detection of the reader malfunction; d) focusing the laser beam with a focusing lens; e) mounting the laser diode and the focusing lens adjacent each other on a support; and f) forming a hole in the support between the laser diode and the focusing lens; and g) mounting the auxiliary photodiode on a printed circuit board at a location juxtaposed with the hole in the support.
18. The method of claim 4, wherein the step of mounting the auxiliary photodiode is performed by surface mounting the auxiliary photodiode on the printed circuit board.
20. The method of claim 4, and the step of reflecting a fraction of the laser beam by the focusing lens through the hole to the auxiliary photodiode.
21. A laser power control method in an electro-optical reader for reading indicia, comprising the steps of: a) generating a laser beam having an output power with a laser diode; b) independently monitoring an operating condition of the reader with dual monitors, each monitor being operative for independently detecting reader malfunction when the operating condition differs from a preestablished condition, and wherein the monitoring step is performed by a monitor photodiode and an auxiliary photodiode; and c) controlling the output power of the laser beam upon detection of the reader malfunction; and d) surrounding the auxiliary photodiode with an enclosure to prevent stray light from entering the auxiliary photodiode. [THIS PAGE IS INTENTIONALLY LEFT BLANK]
[THIS PAGE IS INTENTIONALLY LEFT BLANK]
PCT/US2007/079815 2006-09-28 2007-09-28 Laser power control arrangements in electro-optical readers WO2008039963A2 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US11/528,909 2006-09-28
US11/528,909 US7743989B2 (en) 2006-09-28 2006-09-28 Laser power control arrangements in electro-optical readers

Publications (3)

Publication Number Publication Date
WO2008039963A2 WO2008039963A2 (en) 2008-04-03
WO2008039963A3 WO2008039963A3 (en) 2008-08-07
WO2008039963B1 true WO2008039963B1 (en) 2008-09-25

Family

ID=39231000

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/US2007/079815 WO2008039963A2 (en) 2006-09-28 2007-09-28 Laser power control arrangements in electro-optical readers

Country Status (2)

Country Link
US (1) US7743989B2 (en)
WO (1) WO2008039963A2 (en)

Families Citing this family (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US7743989B2 (en) 2006-09-28 2010-06-29 Symbol Technologies, Inc. Laser power control arrangements in electro-optical readers
US8028918B2 (en) * 2007-10-31 2011-10-04 Symbol Technologies, Inc. Enhanced monitoring of laser output power in electro-optical readers
US8002186B2 (en) * 2008-10-23 2011-08-23 Symbol Technologies, Inc. Laser power control arrangements in electro-optical readers
US8167208B2 (en) * 2010-06-23 2012-05-01 Symbol Technologies, Inc. Arrangement for and method of controlling monitor photodiode leakage current in lasers in electro-optical readers
US8508791B1 (en) * 2012-01-23 2013-08-13 Xerox Corporation Image feedforward laser power control for a multi-mirror based high power imager
US9318153B2 (en) 2014-03-31 2016-04-19 Seagate Technology Llc HAMR drive fault detection system
US9336831B2 (en) * 2014-10-10 2016-05-10 Seagate Technology Llc HAMR drive fault detection system

Family Cites Families (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4575625A (en) * 1983-09-27 1986-03-11 Knowles Carl H Integral hand-held laser scanner
US7428995B1 (en) * 1993-10-25 2008-09-30 Symbol Technologies, Inc. Scanning devices and methods using surface emitting laser diodes
JPH10172170A (en) * 1996-10-09 1998-06-26 Sanyo Electric Co Ltd Optical pickup device and its production
JP2002178559A (en) * 2000-12-14 2002-06-26 Asahi Optical Co Ltd Output controlling circuit for laser scanning unit
US7296743B2 (en) 2004-07-23 2007-11-20 Symbol Technologies, Inc. Laser power control arrangements in electro-optical readers
US7346087B2 (en) * 2005-03-04 2008-03-18 Finisar Corporation Method for performing eye safety measurements on laser emitter devices
US7743989B2 (en) 2006-09-28 2010-06-29 Symbol Technologies, Inc. Laser power control arrangements in electro-optical readers

Also Published As

Publication number Publication date
US7743989B2 (en) 2010-06-29
WO2008039963A3 (en) 2008-08-07
US20080078835A1 (en) 2008-04-03
WO2008039963A2 (en) 2008-04-03

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