Selectable aiming pattern for an imaging-based bar code reader

1. An aiming pattern assembly for an imaging-based bar code reader wherein the bar code reader includes an imaging system generating image frames of a target object within a field of view and having a working range over which a target bar code within the field of view is capable of being imaged and decoded, the working range being subdivided into a near range and a non-overlapping far range, the near range being closer to the reader and the far range being further from the reader, the aiming pattern assembly comprising:

a light source assembly generating focused light;

a pattern shaping assembly receiving focused light from the light source assembly and including a first area and a non-overlapping second area, focused light passing through the first area creating a first aiming pattern projected toward the field of view and passing through the second area creating a second aiming pattern projected toward the field of view, a center line of the first aiming pattern intersecting a center line of the field of view within the near range of the working range and a center line of the second aiming pattern intersecting the center line of the field of view within the far range of the working range; and

a pattern selection assembly receiving the first and second aiming patterns and passing at least one of the first and second aiming patterns.

2. The aiming pattern assembly of claim 1 wherein the pattern selection assembly passes a selected one of the first and second aiming patterns and blocks the other of the first and second aiming patterns.

3. The aiming pattern assembly of claim 1 wherein the pattern selection assembly passes the first aiming pattern when a target bar code is determined to be within the near range of the working range and passes the second aiming pattern when a target bar code is determined to be within the far range of the working range.

4. The aiming pattern assembly of claim 1 wherein the light source assembly generates polarized light and includes a laser light source emits light within a visible spectrum.

5. The aiming pattern assembly of claim 4 wherein the pattern selection assembly comprises a liquid crystal element and a polarizing filter.

6. An imaging-based bar code reader comprising:

an imaging system generating image frames of a target object within a field of view and having a working range over which a target bar code within the field of view is capable of being imaged and decoded, the working range being subdivided into a near range and a non-overlapping far range, the near range being closer to the reader and the far range being further from the reader; and

an aiming pattern assembly for generating a visible aiming pattern to facilitate aiming the reader at the target bar code, the aiming pattern assembly including:

a light source assembly generating focused light;

a pattern shaping assembly position receiving focused light from the light source assembly and including a first area and a non-overlapping second area, focused light passing through the first area creating a first aiming pattern projected toward the field of view and passing through the second area creating a second aiming pattern projected toward the field of view, a center line of the first aiming pattern intersecting a center line of the field of view within the near range of the working range and a center line of the second aiming pattern intersecting the center line of the field of view within the far range of the working range; and

a pattern selection assembly receiving the first and second aiming patterns and passing at least one of the first and second aiming patterns.

7. The imaging-based bar code reader of claim 6 wherein the pattern selection assembly passes a selected one of the first and second aiming patterns and blocks the other of the first and second aiming patterns.

8. The imaging-based bar code reader of claim 6 wherein the pattern selection assembly passes the first aiming pattern when a target bar code is determined to be within the near range of the working range and passes the second aiming pattern when a target bar code is determined to be within the far range of the working range.

9. The imaging-based bar code reader of claim 6 wherein the light source assembly generates polarized light includes a laser light source that emits light in the visible spectrum.

10. The imaging-based bar code reader of claim 9 wherein the pattern selection assembly comprises a liquid crystal element and a polarizing filter.

11. A method of generating an aiming pattern to facilitate the aiming of an imaging-based bar code reader at a target bar code wherein the bar code reader includes an imaging system generating image frames of a field of view and has a working range over which a target bar code within the field of view is capable of being imaged and decoded, the working range being subdivided into a near range and a non-overlapping far range, the near range being closer to the reader and the far range being further from the reader, the steps of the method comprising:

providing an aiming pattern assembly including: a light source assembly generating focused light; a pattern shaping element position receiving focused light from the light source assembly and including a first area and a non-overlapping second area, focused light passing through the first area creating a first aiming pattern projected toward the field of view and passing through the second area creating a second aiming pattern projected toward the field of view, a center line of the first aiming pattern intersecting a center line of the field of view within the near range of the working range and a center line of the second aiming pattern intersecting the center line of the field of view within the far range of the working range; and a pattern selection assembly receiving the first and second aiming patterns and passing at least one of the first and second aiming patterns;

determining if a target bar code is within the near range or the far range of the working range; and

passing the first aiming pattern if the target bar code is determined to be within the near range of the working range and passing the second aiming pattern if the target bar code is determined to be within the far range of the working range.

12. An aiming pattern assembly for an imaging-based bar code reader wherein the bar code reader includes an imaging system generating image frames of a target object within a field of view and having a working range over which a target bar code within the field of view is capable of being imaged and decoded, the working range being subdivided into a near range and a non-overlapping far range, the near range being closer to the reader and the far range being further from the reader, the aiming pattern assembly being offset from the imaging system in an offset direction that is perpendicular to an optical axis of the imaging system, the aiming pattern assembly comprising:

a light source assembly generating focused light;

a pattern shaping element receiving focused light from the light source assembly and including a first area and a non-overlapping second area, focused light passing through the first area creating a first aiming pattern projected toward the field of view and passing through the second area creating a second aiming pattern projected toward the field of view, a center line of the first aiming pattern intersecting a plane through a center line of the field of view within the near range of the working range, the plane being orthogonal to the offset direction and a center line of the second aiming pattern intersecting the plane through the center line of the field of view within the far range of the working range; and

a pattern selection assembly receiving the first and second aiming patterns and passing at least one of the first and second aiming patterns.

13. The aiming pattern assembly of claim 12 wherein the pattern selection assembly passes a selected one of the first and second aiming patterns and blocks the other of the first and second aiming patterns.

14. The aiming pattern assembly of claim 12 wherein the pattern selection assembly passes the first aiming pattern when a target bar code is determined to be within the near range of the working range and passes the second aiming pattern when a target bar code is determined to be within the far range of the working range.

15. The aiming pattern assembly of claim 12 wherein the light source assembly generates polarized light and includes a laser light source which emits light in the visible spectrum.

16. The aiming pattern assembly of claim 15 wherein the pattern selection assembly comprises a liquid crystal element and a polarizing filter.

17. An imaging-based bar code reader comprising:

an imaging system generating image frames of a target object within a field of view and having a working range over which a target bar code within the field of view is capable of being imaged and decoded, the working range being subdivided into a near range and a non-overlapping far range, the near range being closer to the reader and the far range being further from the reader; and

an aiming pattern assembly being offset from the imaging system in an offset direction that is perpendicular to an optical axis of the imaging system, the aiming pattern assembly including:

a light source assembly generating focused light;

a pattern shaping element receiving focused light from the light source assembly and including a first area and a non-overlapping second area, focused light passing through the first area creating a first aiming pattern projected toward the field of view and passing through the second area creating a second aiming pattern projected toward the field of view, a center line of the first aiming pattern intersecting a plane through a center line of the field of view within the near range of the working range, the plane being orthogonal to the offset direction and a center line of the second aiming pattern intersecting the plane through the center line of the field of view within the far range of the working range; and

a pattern selection assembly receiving the first and second aiming patterns and passing at least one of the first and second aiming patterns.

18. The imaging-based bar code reader of claim 17 wherein the pattern selection assembly passes a selected one of the first and second aiming patterns and blocks the other of the first and second aiming patterns.

19. The imaging-based bar code reader of claim 17 wherein the pattern selection assembly passes the first aiming pattern when a target bar code is determined to be within the near range of the working range and passes the second aiming pattern when a target bar code is determined to be within the far range of the working range.

20. The imaging-based bar code reader of claim 17 wherein the light source assembly generates polarized light and includes a laser light source which emits light in the visible spectrum.

21. The imaging-based bar code reader of claim 20 wherein the pattern selection assembly comprises a liquid crystal element and a polarizing filter.

22. The imaging-based bar code reader of claim 17 wherein the light source assembly generates polarized light and includes an LED which emits light in the visible spectrum and a polarizing lens to polarize the light emitted by the LED.

23. The imaging-based bar code reader of claim 22 wherein the pattern selection assembly comprises a liquid crystal element and a polarizing filter.