Method of and system for producing images of objects using planar laser illumination beams and image detection arrays

• US 6,631,842 B1
• Filed: 11/24/2000
• Issued: 10/14/2003
• Est. Priority Date: 06/07/2000
• Status: Expired due to Fees

• Current Assignee: Metrologic Instruments Incorporated (Honeywell International Inc.)
• Original Assignee: Metrologic Instruments Incorporated (Honeywell International Inc.)
• Inventors: Zhu, Xiaoxun, Amundsen, Thomas, Naylor, Charles A., Knowles, Carl Harry, Schnee, Michael D., Tsikos, Constantine J., Dobbs, Russell Joseph
• Primary Examiner(s): Lee, Michael G.
• Assistant Examiner(s): Kim, Ahshik
• Application Number:
  US09/721,885
• Time in Patent Office: 1,054 Days
• Field of Search: 235/462.01, 235/462.22, 235/462.42, 235/470, 235/472.01
• US Class Current: 235/454
• CPC Class Codes: B82Y 15/00 Nanotechnology for interacting, sensing or actuating, e.g. quantum dots as markers in protein assays or molecular motors
• CPC Class Codes: G02B 26/10 Scanning systems
• CPC Class Codes: G02B 26/105 with one or more pivoting mirrors or galvano-mirrors G02B26/101 takes precedence
• CPC Class Codes: G02B 27/48 Laser speckle optics
• CPC Class Codes: G06K 7/10554 Moving beam scanning
• CPC Class Codes: G06K 7/10574 Multiple sources
• CPC Class Codes: G06K 7/10633 by oscillation
• CPC Class Codes: G06K 7/10683 Arrangement of fixed elements
• CPC Class Codes: G06K 7/10722 Photodetector array or CCD scanning
• CPC Class Codes: G06K 7/10732 Light sources
• CPC Class Codes: G06K 7/10811 Focalisation
• CPC Class Codes: G06K 7/10861 sensing of data fields affixed to objects or articles, e.g. coded labels postal sorting B07C3/14, conveying articles B65G47/48
• CPC Class Codes: H01S 5/02325 Mechanically integrated components on mount members or optical micro-benches

Abstract

Methods of and systems for illuminating objects using planar laser illumination beams having substantially-planar spatial distribution characteristics that extend through the field of view (FOV) of image formation and detection modules employed in such systems. Each planar laser illumination beam is produced from a planar laser illumination beam array (PLIA) comprising an plurality of planar laser illumination modules (PLIMs). Each PLIM comprises a visible laser diode (VLD, a focusing lens, and a cylindrical optical element arranged therewith. The individual planar laser illumination beam components produced from each PLIM are optically combined to produce a composite substantially planar laser illumination beam having substantially uniform power density characteristics over the entire spatial extend thereof and thus the working range of the system. Preferably, each planar laser illumination beam component is focused so that the minimum beam width thereof occurs at a point or plane which is the farthest or maximum object distance at which the system is designed to acquire images, thereby compensating for decreases in the power density of the incident planar laser illumination beam due to the fact that the width of the planar laser illumination beam increases in length for increasing object distances away from the imaging optics. By virtue of the present invention, it is now possible to use both VLDs and high-speed CCD-type image detectors in conveyor, hand-held and hold-under type scanning applications alike, enjoying the advantages and benefits that each such technology has to offer, while avoiding the shortcomings and drawbacks hitherto associated therewith.

Claims