Optical assembly having lens offset from optical axis

• US 6,457,645 B1
• Filed: 04/13/1999
• Issued: 10/01/2002
• Est. Priority Date: 04/13/1999
• Status: Expired due to Term

• Current Assignee: Hewlett Packard Enterprise Development LP (Hewlett-Packard Enterprise Company)
• Original Assignee: Hewlett-Packard Company (HP Inc.)
• Inventors: Gardner, Richard Lynn Jr.
• Primary Examiner(s): LE, THIEN MINH
• Application Number:
  US09/290,842
• Time in Patent Office: 1,267 Days
• Field of Search: 235/462-1-4, 235/472-1-4, 235/454, 235/375, 235/494
• US Class Current: 235/462.23
• CPC Class Codes: G06K 7/10702 Particularities of propagating elements, e.g. lenses, mirrors G06K7/10831 takes precedence
• CPC Class Codes: G06K 7/10722 Photodetector array or CCD scanning

Abstract

An improved optical assembly for acquiring an image of an object is disclosed. The optical assembly comprises an illuminator used to illuminate the object and an imaging device used to generate an image of the object. The illuminator has a light source associated with an illuminating lens wherein the illuminating lens has an optical axis. A light beam is generated by the light source and passes through the illuminating lens to illuminate the object. The imaging device has a photosensor associated with an imaging lens wherein the imaging lens has an optical axis. An image beam of light reflects from the object and is focused by the imaging lens onto the photosensor. The light beams associated with the illuminator and the imaging device are steered to intersect at a common point on the object. Steering the light beam is accomplished by spacing the light source a distance from the optical axis of the illuminating lens. Steering the image beam is accomplished by spacing the photosensor a distance from the optical axis of the imaging lens.

Claims

1. An optical assembly for acquiring an image of an object, said optical assembly comprising:

a photosensor array;

an imaging light path extending between said object and said photosensor array;

an imaging lens located along said imaging light path, said imaging lens having an imaging lens optical axis associated therewith;

wherein said imaging lens optical axis is spaced a first distance from said photosensor array in a direction normal to said imaging lens optical axis.

2. The optical assembly of claim 1 wherein said imaging lens optical axis is spaced a second distance from said object in a direction normal to said imaging lens optical axis.

3. The optical assembly of claim 1 wherein said photosensor array is a linear photosensor array.

4. The optical assembly of claim 1 wherein said first distance is between about 3.5 millimeters and about 4.5 millimeters.

5. The optical assembly of claim 1 and further comprising:

a light source;

an illumination light path extending from said light source to said object;

an illumination lens located along said illumination light path, said

illumination lens having an illumination lens optical axis associated therewith;

wherein said illumination lens optical axis is spaced a third distance from said light source in a direction normal to said illumination lens optical axis.

6. The optical assembly of claim 5, further comprising a substrate and wherein both said photosensor array and said light source are mounted to said substrate.

7. The optical assembly of claim 6 wherein said substrate is a substantially rigid substrate.

8. The optical assembly of claim 5 wherein said illumination lens optical axis is spaced a fourth distance from said object in a direction normal to said illumination lens optical axis.

9. The optical assembly of claim 5 wherein said third distance is between about 2.4 millimeters and about 2.6 millimeters.

10. The optical assembly of claim 1 wherein said object is a bar code and said optical assembly is a bar code reader.

11. An optical assembly for acquiring an image of an object, said optical assembly comprising:

a light source;

an illumination light path extending between said light source and said object;

at least one illumination lens located along said illumination light path, said at least one illumination lens having an illumination lens optical axis associated therewith;

wherein said illumination lens optical axis is spaced a first distance from said light source in a direction normal to said illumination lens optical axis.

12. The optical assembly of claim 11 wherein said illumination lens optical axis is spaced a second distance from said object in a direction normal to said illumination lens optical axis.

13. The optical assembly of claim 11 wherein said first distance is between about 2.4 millimeters and about 2.6 millimeters.

14. A method of imaging an object, said method comprising:

providing a photosensor array;

providing an imaging lens, said imaging lens having an imaging lens optical axis associated therewith, wherein said imaging lens optical axis is spaced a first distance from said photosensor array in a direction normal to said imaging lens optical axis;

locating said photosensor array relative to said object such that said photosensor array is spaced from said object in a direction normal to said imaging lens optical axis;

imaging said object with said photosensor array by directing a light path from said object through said imaging lens to said photosensor array.

15. The method of claim 14 wherein said photosensor array is a linear photosensor array.

16. The method of claim 14 wherein said first distance is between about 3.5 millimeters and about 4.5 millimeters.

17. The method of claim 14 and further comprising:

providing a light source;

providing an illumination lens, said illumination lens having an illumination lens optical axis associated therewith, wherein said illumination lens optical axis is spaced a second distance from said light source in a direction normal to said illumination lens optical axis;

illuminating said object with said light source by directing a light path from said light source through said illumination lens to said object.

18. The method of claim 17 further comprising providing a substrate having a substantially planar surface formed thereon;

and wherein

said providing a photosensor array comprises providing said photosensor array mounted to said substantially planar surface; and

said providing a light source comprises providing said light source mounted to said substantially planar surface in spaced relation to said photosensor array.

19. The method of claim 18 wherein said substrate is a substantially rigid substrate.

20. The method of claim 17 wherein said second distance is between about 2.4 millimeters and about 2.6 millimeters.

21. The method of claim 14 wherein said object is a bar code.