Optical scanners having dual surface optical elements for dual working ranges

• US 5,859,417 A
• Filed: 08/15/1997
• Issued: 01/12/1999
• Est. Priority Date: 06/14/1991
• Status: Expired due to Term

• Current Assignee: Symbol Technologies, Inc. (Zebra Technologies Corporation)
• Original Assignee: Symbol Technologies, Inc. (Zebra Technologies Corporation)
• Inventors: Bridgelall, Raj, Barkan, Edward, He, Duanfeng, Gurevich, Vladimir, Katz, Joseph, Dvorkis, Paul, Shepard, Howard, Krichever, Mark, Kahn, Joel, Metlitsky, Boris, Tsi, David, Isaac, Richard
• Primary Examiner(s): Wong, Don
• Assistant Examiner(s): Frech, Karl
• Application Number:
  US08/912,147
• Time in Patent Office: 515 Days
• Field of Search: 235/462, 235/467, 235/472, 235/454
• US Class Current: 235/462.39
• CPC Class Codes: G06K 7/10594 Beam path
• CPC Class Codes: G06K 7/10623 Constructional details
• CPC Class Codes: G06K 7/10633 by oscillation
• CPC Class Codes: G06K 7/10792 Special measures in relation to the object to be scanned
• CPC Class Codes: G06K 7/10801 Multidistance reading

Abstract

An optical scanner such as a bar code scanner includes a segmented fold mirror, the individual sections of which have different profiles. By directing the scanning laser beam across the fold mirror, a plurality of scan lines are created, at different distances from the scanner. This provides increased flexibility by extending the scanner'"'"'s working range. In alternative embodiments, a collector mirror and/or a scanning mirror may be segmented. In addition, beam shaping may be provided by reflecting the beam from one or more aplanar surfaces.

Claims

1. An optical scanner for reading indicia having areas of different light reflectivity, comprising:

light source for producing a light beam, the light source including a beam shaping optical element;

a scanning optical element for receiving the light beam and producing a scanning outgoing light beam therefrom; and

a multi-surface reflector having a first surface of a first profile and a second surface of a second profile,

wherein the beam shaping optical element of the light source, the scanning optical element, and the first and second profiles of the multi-surface reflector together shape the light beam so that the scanner is adapted to read an indicia at a first distance when the beam is reflected from the first surface and at a second distance when the beam is reflected from the second surface;

wherein the multi-surface reflector comprises a fold mirror, the fold mirror being arranged to receive the scanning outgoing light beam and to direct it towards an indicia to be read.

2. A scanner as claimed in claim 1 in which the fold mirror also collects light reflected from the indicia to be read, and directs it to a photodetector.

3. A scanner as claimed in claim 1 in which the light from the first surface defines a first scan line and light from the second surface defines a second scan line, the first and second scan lines being in the same direction with respect to the scanner but adapted for reading an indicia at different distances.

4. A scanner as claimed in claim 3 in which, in use, the first and second scan lines alternate.

5. A scanner as claimed in claim 1 in which the first surface is planar.

6. A scanner as claimed in claim 1 in which the second surface is aplanar.

7. A scanner as claimed in claim 6 in which the second surface is cylindrical.

8. A scanner as claimed in claim 6 in which the second surface is toroidal.

9. A scanner as claimed in claim 1 in which the light source is a laser source and the beam shaping optical element comprises an optical element in the path of the light beam emerging from the laser source.

10. A scanner as claimed in claim 9 in which the optical element comprises a lens (38).

11. An optical scanner for reading indicia having areas of differing light reflectivity, the scanner including a movable scanning optical element and a multi-surface fold mirror having a first surface of a first profile and a second surface of a second, different, profile, wherein the fold mirror is stationary relative to the movable scanning optical element.