Electro-optical scan module using selectable mirrors

• US 6,722,566 B1
• Filed: 11/07/2002
• Issued: 04/20/2004
• Est. Priority Date: 11/07/2002
• Status: Active Grant

• Current Assignee: Symbol Technologies, LLC (Zebra Technologies Corporation)
• Original Assignee: Symbol Technologies, Inc. (Zebra Technologies Corporation)
• Inventors: Grossfeld, Henry, Gofman, Yuri, Drzymak, Mark, Healey, Timothy, Dvorkis, Paul, Shepard, Howard
• Primary Examiner(s): ST CYR, DANIEL
• Application Number:
  US10/289,960
• Time in Patent Office: 530 Days
• Field of Search: 235/454, 235/462.01, 235/462.36, 235/462.4, 235/462.45, 235/472.01
• US Class Current: 235/454
• CPC Class Codes: G06K 7/10683 Arrangement of fixed elements
• CPC Class Codes: G06K 7/10693 for omnidirectional scanning
• CPC Class Codes: G06K 7/10702 Particularities of propagating elements, e.g. lenses, mirrors G06K7/10831 takes precedence

Abstract

Mirrors having different optical properties are selected to change the cross-section of a beam electro-optical reader for reading bar code symbols.

Claims

1. An arrangement for scanning indicia in a system for electro-optically reading the indicia, the arrangement comprising:

a) a support;

b) a hub mounted on the support for turning movement about an axis;

c) a plurality of optical elements mounted on the hub for joint movement therewith, and having different optical characteristics for differently optically modifying light incident on a respective element, and for directing the differently optically modified light along an optical path toward the indicia to be read; and

d) a drive for selectively positioning one of the elements at a reference position in the optical path, and for oscillating said one of the elements about the axis to scan the indicia with the differently optically modified light.

2. The arrangement of claim 1, wherein the optical elements are mirrors.

3. The arrangement of claim 2, wherein one of the mirrors has a substantially planar reflecting surface, and another of the mirrors has a curved reflecting surface.

4. The arrangement of claim 1, wherein the drive includes a permanent magnet on the hub for generating a permanent magnetic field, a first electromagnetic coil for generating a first magnetic field that interacts with the permanent field to turn the hub, and a first pole piece for attracting the permanent field of the magnet to position said one of the elements at the reference position.

5. The arrangement of claim 4, wherein the optical elements are angularly spaced apart about the axis, and wherein the drive includes a second electromagnetic coil for generating a second magnetic field that interacts with the permanent field to turn the hub, and a second pole piece angularly spaced apart from the first pole piece for attracting the permanent field of the magnet to position another of the elements about the reference position.

6. The arrangement of claim 1, wherein the drive includes a permanent magnet on the hub for generating a permanent magnetic field, and a plurality of electromagnetic coils for respectively generating alternating magnetic fields that respectively interact with the permanent field to oscillate said one of the elements in the reference position.

7. The arrangement of claim 1, wherein the drive includes a permanent magnet, and wherein the elements are mirrors, and wherein the mirrors and the magnet are angularly spaced apart about the axis on the hub.

8. The arrangement of claim 1, wherein the drive is operative for repetitively oscillating said one of the elements in opposite circumferential directions about the axis a plurality of times per second.

9. The arrangement of claim 1, wherein the optical characteristics of one of the elements modifies a cross-section of the light incident therein.

10. The arrangement of claim 1, wherein the drive is manually activated.

11. The arrangement of claim 1, wherein the drive is automatically activated.

12. The arrangement of claim 1, wherein the drive, the hub and the support constitute a scan module replaceably mountable as a unit in the system.

13. The arrangement of claim 1, and further comprising a light source for emitting a light beam at said one of the elements.

14. The arrangement of claim 13, and further comprising means for sweeping the light beam along a first scan direction, and wherein the light incident on said one of the elements is the light beam being swept along the first scan direction.