Claims
- 1. A scan module for use in bar code reading systems for reading indicia having portions of different light reflectivity and located on a target at a distance from the scan module, comprising:
a) a generally rectangular module including a support having a generally planar base and planar peripheral sides orthogonal thereto; b) a laser light source mounted on the support for producing a light beam; c) a scan mirror mounted on the support in spaced relationship to the light source and positioned so that the light beam from the light source is directed by the scan mirror along an optical path exterior to the scan module in a direction generally orthogonal to the base; d) a drive for moving the light beam in a scanning pattern substantially parallel to the peripheral sides of the support and across the indicia to be read; and e) a sensor mounted on the support for directly receiving reflected light from the target and converting the reflected light into an electrical signal.
- 2. The module of claim 1, wherein the support is approximately 8.8 mm×9.8 mm×5.7 mm in size.
- 3. The module of claim 2, wherein the light beam is scanned parallel to the peripheral side of 9.8 mm in length.
- 4. The module of claim 1, wherein the drive includes an energizable electromagnetic coil drive member and a permanent magnet drive member in operational proximity thereto, for imparting a force to the scan mirror, thereby resulting in movement of the scan mirror in an oscillating manner about an axis, and thereby causing the light beam reflected off the scan mirror to sweep over the indicia to be read.
- 5. The module of claim 4, wherein the scan mirror is mounted on a shaft, and wherein one of the drive members is mounted on the shaft, and the other of the drive members is mounted on the support.
- 6. The module of claim 5, wherein the shaft is rotatably secured to the support.
- 7. The module of claim 5, wherein the magnet drive member is mounted on the shaft.
- 8. The module of claim 1, wherein the generally planar base is a printed circuit card on which the laser light source and the sensor is mounted.
- 9. The module of claim 1, further including a fold mirror for reflecting the light beam from the laser light source to the scan mirror.
- 10. A scan module for use in a reader for electro-optically reading indicia, comprising:
a) a support; b) a generally planar base mounted to the support; c) a laser light source mounted on the support and operative for emitting a laser beam in a direction generally perpendicular to the base; d) a scan mirror mounted on the support for oscillating movement; e) optical means mounted on the support for changing the direction of the laser beam, and for directing the laser beam to the scan mirror for reflection therefrom toward the indicia; f) a drive on the support for oscillating the scan mirror to sweep the laser beam across the indicia for scattering therefrom; and g) a sensor for detecting scattered light from the indicia, and for generating an electrical signal corresponding to the detected scattered light and indicative of the indicia.
- 11. The module of claim 10, wherein the base is a printed circuit board.
- 12. The module of claim 11, wherein the printed circuit board has holes, and wherein the laser light source has pins extending through the holes.
- 13. The module of claim 10, wherein the optical means includes a fold mirror for changing the direction of the laser beam by 90°, and a focusing element and an aperture operative for focusing the laser beam at a focus located remotely from the scan mirror.
- 14. The module of claim 13, wherein the focusing element is mounted for movement on the support to an adjusted position, and is fixed in said adjusted position.
- 15. The module of claim 13, wherein the fold mirror is mounted between the light source and the focusing element.
- 16. The module of claim 10, wherein the drive includes a hub oscillatable about an axis, and wherein the scan mirror is mounted on the hub for joint oscillation therewith, and wherein the drive includes a permanent magnet mounted on the hub for joint oscillation with the scan mirror.
- 17. The module of claim 16, wherein the permanent magnet has a magnetic axis, and wherein the drive further includes an energizable electromagnetic coil mounted on the base and having an electromagnetic axis extending generally perpendicular to the magnetic axis in a rest position of the scan mirror.
- 18. The module of claim 17, wherein the coil has a central circular opening having a diameter less than the length of the permanent magnet, and wherein the permanent magnet is always situated outside of the coil opening during the oscillating movement.
- 19. The module of claim 17; and further comprising means for centering the scan mirror in the rest position upon de-energization of the coil, including a pair of pole piece portions and spaced apart along the magnetic axis of the permanent magnet.
- 20. The module of claim 10, wherein the sensor includes a photodetector mounted on the base, and a collector for directly collecting and directing the scattered light to the photodetector while bypassing the scan mirror.
- 21. The module of claim 20, wherein the base is a printed circuit board, and wherein the photodetector is mounted on one surface of the printed circuit board and has surface-mounted connectors for making an electrical connection at said one surface of the printed circuit board.
- 22. The module of claim 10, wherein the support occupies a volume of about 8.8 mm×9.8 mm×5.7 mm and has a parallelepiped shape.
- 23. The module of claim 10, wherein the base is a printed circuit board having a major surface, and wherein the drive includes an electromagnetic coil, and wherein the sensor includes a photodetector; and wherein the laser light source, the coil and the photodetector are all mounted at said major surface.
- 24. The module of claim 23; and further comprising signal processing circuitry for processing the electrical signal and mounted at another surface of the printed circuit board opposite to the major surface.
- 25. The module of claim 24; and further comprising power circuitry on the other surface of the printed circuit board for supplying electrical power to the laser light source, the coil and the photodetector.
- 26. The module of claim 10, wherein the optical means includes a prism having an internal totally reflecting wall for changing the direction of the laser beam by 90°, and is constituted of a focusing material for focusing the laser beam at a focus located remotely from the scan mirror.
- 27. An arrangement for restoring a movable scan mirror to a rest position in a reader for electro-optically reading indicia, comprising:
a) a support; b) a hub mounted on the support for oscillating movement, the scan mirror being mounted on the hub for joint movement therewith; c) a permanent magnet mounted on the hub for joint movement therewith and having a magnetic axis; d) an energizable electromagnetic coil mounted on the support and having an electromagnetic axis generally perpendicular to the magnetic axis in the rest position; and e) a pair of pole portions fixedly spaced apart along the magnetic axis of the permanent magnet, the permanent magnet having poles that are magnetically attracted to the pole portions to restore the scan mirror to the rest position upon de-energization of the coil.
- 28. The arrangement of claim 27, wherein the support includes a printed circuit board lying in a plane, and wherein the electromagnetic axis is generally perpendicular to the plane of the printed circuit board.
- 29. The arrangement of claim 27, wherein the support includes a printed circuit board lying in a plane, and wherein the electromagnetic axis is generally parallel to the plane of the printed circuit board.
- 30. The arrangement of claim 27, wherein the pole portions are located at opposite ends of a pole piece.
- 31. An arrangement for reading bar code symbols, comprising:
a) a support; b) a laser diode on the support for generating a laser light beam; c) a scan mirror for reflecting the light beam toward a bar code symbol located exteriorly of the support; d) a holder for supportably mounting the scan mirror; and e) a drive including an energizable electromagnetic coil drive member and a permanent magnet drive member in operational proximity thereto, for imparting a force to the holder, thereby resulting in movement of the scan mirror and the holder in an oscillating manner about an axis, and thereby causing the light beam reflected off the scan mirror to sweep over the symbol to be read.
- 32. The arrangement of claim 31, wherein one of the drive members is mounted on the holder, and wherein the other of the members is mounted on the support.
- 33. The arrangement of claim 31, wherein the holder is mounted on a shaft rotatably secured to the support.
- 34. The arrangement of claim 32, wherein the magnet drive member is mounted on the holder.
- 35. A method of scanning indicia having parts of different light reflectivity by directing light toward the indicia, and by collecting reflected light returning from the indicia, comprising the steps of:
a) mounting a scan component including a permanent magnet on a holder held in an equilibrium position for angular oscillating movement in alternate circumferential directions between first and second scan end positions; b) providing a centering element on the support which magnetically interacts with the permanent magnet so as to urge the scan component to the equilibrium position; and c) electromagnetically driving the scan component in alternate first and second circumferential directions to angularly oscillate the scan component between the first and second scan end positions.
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of U.S. provisional patent application Serial No. 60/282,272, filed Apr. 6, 2001.
Provisional Applications (1)
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Number |
Date |
Country |
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60282272 |
Apr 2001 |
US |