Laser light beam scanning device for reading coded information

Patent metadata

Field	Value
Publication number	US-2016180127-A1
Application number	US-201314910394-A
Country	US
Kind code	A1
Filing date	Aug 6, 2013
Priority date	Aug 6, 2013
Publication date	Jun 23, 2016
Grant date	—

Abstract

The present invention is relative to a scanning device ( 100 ) of a laser light beam ( 7,8 ) for reading coded information, comprising:
an emission source of a laser light beam ( 7,8 ), the laser light beam defining an optical path ( 10 a, 10 b ); an optical element ( 17 ) for scanning the laser light beam on a support containing coded information; characterized in that it further comprises a linear polarizer ( 16 ) located along the optical path ( 10 a, 10 b ) of said laser light beam ( 7,8 ), upstream the optical element for scanning ( 17 ), said polarizer being apt to linearly polarize a first portion of said laser light beam in substantially one first plane (s) and direct said polarized portion only towards said optical element for scanning.

First claim

1 . A scanning device of a laser light beam for reading coded information, comprising:
an emission source of a laser light beam, the laser light beam defining an optical path; an optical element for scanning the laser light beam on a support containing coded information; and a linear polarizer located along the optical path of said laser light beam, upstream of the optical element for scanning, said polarizer being apt to linearly polarize a first portion of said laser light beam in substantially one first plane (s) and direct said polarized portion towards said optical element for scanning.

2 . The scanning device according to claim 1 , wherein said linear polarizer is substantially transparent for a second portion (p) of said laser light beam not directed towards said optical element for scanning.

3 . The scanning device according to claim 2 , further comprising
an optical element for collecting the light coming from said support; a photoreceiver, which is sensitive to the light collected from the collecting optical element, to generate a signal representative of the information contained in said support; wherein said linear polarizer is located upstream of said collecting optical element in the propagating direction of said light coming from said support.

4 . The scanning device according to claim 1 , said scanning device being retroreflective.

5 . The scanning device according to claim 1 , including a further emission source of a further laser light beam which defines a further optical path, said optical path of said laser light beam and said further optical path of said further optical laser light beam being substantially parallel, wherein said linear polarizer is located along the optical path of said laser light beam and along the further optical path of said further laser light beam and upstream the optical element for scanning in the propagation direction of the laser light beam and the further laser light beam.

6 . The scanning device according to claim 1 , wherein said emission source is apt to emit laser light substantially linearly polarized along a plane (s), said plane being coincident to the first plane.

7 . The scanning device according to claim 1 , wherein said linear polarizer is apt to selectively reflect polarized light along said first plane contained in the laser light beam.

8 . The scanning device according to claim 7 , wherein said linear polarizer is apt to transmit a second portion of said laser light beam not polarized in said first plane (s).

9 . The scanning device according to claim 1 , wherein said linear polarizer includes a beam-splitter.

10 . The scanning device according to claim 6 , wherein said linear polarizer includes a first surface on which the laser light beam impinges and wherein the laser light beam exiting said emission source is substantially s-polarized with respect to said first surface.

11 . The scanning device according to claim 1 , wherein said linear polarizer includes a deflecting mirror located at the Brewster's angle for said laser light beam impinging on said linear polarizer.

12 . The scanning device according to claim 1 , wherein said linear polarizer includes a polarizing beam-splitter cube apt to split the laser light beam into two orthogonally polarized components.

13 . The scanning device according to claim 1 , wherein said linear polarizer includes a window having opposed first and second surfaces, and further including a polarization selective coating covering said first surface engineered to separate s- and p-components of the incident laser light beam impinging on said first surface.

14 . The scanning device according to claim 13 , wherein the polarization selective coating is configured to reflect an s-polarization component of the incident laser beam and transmit a p-polarization component of the incident laser beam.

15 . The scanning device according to claim 13 , wherein said linear polarizer includes an anti-reflective coating which covers said second surface.

16 . The scanning device according to claim 13 , wherein said first surface is forming an angle between about 40° and 50° with the direction of propagation of said laser light beam.

17 . The scanning device according to claim 13 , wherein said first surface is forming a Brewster angle relative to the direction of propagation of said laser light beam impinging on said linear polarizer.

18 . The scanning device according to claim 1 , wherein said linear polarizer includes an adjusting device to change the angle formed between said linear polarizer and the direction of propagation of said laser light beam.

19 . The scanning device according to claim 1 , wherein the optical path of said laser light beam between said linear polarizer and said optical element for scanning is free from further optical elements.

20 . The scanning device according to claim 3 , wherein said optical element for collecting the light coming from said support defines an active area, light impinging on said active area being collected towards said photoreceiver, said linear polarizer having a surface wide enough to intercept light from said support upstream said active area substantially along all optical paths to said active area.

21 . The scanning device according to claim 1 , including a light trap to trap a second portion of said laser beam output by said linear polarizer not directed towards said optical element for scanning.

Assignees

• Datalogic IP Tech Srl

Inventors

• Corrain Gabriele

Classifications

• G06K7/10702

  Particularities of propagating elements, e.g. lenses, mirrors (G06K7/10831 takes precedence) · CPC title

• G06K7/10613

  by rotation, e.g. polygon · CPC title

• G06K7/10554 Primary

  Moving beam scanning · CPC title