Optical assembly for barcode scanner

• US 6,607,128 B1
• Filed: 09/11/2000
• Issued: 08/19/2003
• Est. Priority Date: 07/08/1998
• Status: Expired due to Term

• Current Assignee: Hand Held Products Incorporated (Honeywell International Inc.)
• Original Assignee: Welch Allyn Incorporated
• Inventors: Schwartz, Eric D., Hubben, Edward B., Jovanvoski, Brian L., Hunter, Vivian L., McCall, Melvin D.
• Primary Examiner(s): Lee, Michael G.
• Assistant Examiner(s): FRANKLIN, JAMARA ALZAIDA
• Application Number:
  US09/658,811
• Time in Patent Office: 1,072 Days
• Field of Search: 235/462-1-4, 235/454
• US Class Current: 235/454
• CPC Class Codes: G06K 7/10722 Photodetector array or CCD scanning
• CPC Class Codes: G06K 7/10732 Light sources

Abstract

The invention is optical assembly for use in a barcode reader that includes a frame having a rear housing and a pair of arms outwardly extended from the housing. An optical card containing an imaging lens is slidably received in a rear guideway situated between the arms. An aperture card is slidably received in a front guideway situated between the arms in front of the lens. Lamp support brackets are also mounted to either side of the arms. Each bracket contains a pair of LEDs that are aligned in coplanar relation with the imaging lens. A cylindrical lens is mounted in front of the lamp support brackets within the arms of the frame to magnify and focus the illumination from the LED upon a target in barcode space. A horizontally extended field stop aperture is positioned in front of each LED.

Claims

1. An optical assembly for use in an optical reader, said optical assembly comprising:

a support frame having a rear housing containing a solid state imager assembly comprising an imager, an imager support, and a series of leads, wherein said rear housing includes a back surface receiving said solid state imager assembly;

said support frame further including a pair of wall-shaped arms extending forwardly from said rear housing;

an imaging lens assembly received between said wall-shaped arms;

a pair of lamp brackets disposed at either side of said frame;

at least one light emitting diode (LED) carried by each of said lamp brackets, said at least one LED defining inner and outer LED boundary lines; and

a field stop disposed forward of said at least one LED, such that light from said at least one LED passes through said field stop prior to reaching a target barcode,

wherein said at least one LED is disposed so that said boundary lines extend without interruption through said field stop.

2. The optical assembly of claim 1, wherein each of said pair of lamp brackets includes a platform carrying a pair of LED clips.

3. The optical assembly of claim 1, wherein each of said pair of lamp brackets includes a platform carrying a pair of LED clips and a front wall including an aperture defining the field stop.

4. The optical assembly of claim 3, wherein said aperture defining the field stop has at least one dimension in the range of about 0.040 inches to about 0.050 inches.

5. The optical assembly of claim 1, wherein said solid state imager support includes a back surface including a pair of outer spaced apart receiving surfaces for receiving outer regions of said back surface of said imager support.

6. The optical assembly of claim 1, wherein said imaging lens assembly comprises a lens card.

7. The optical assembly of claim 6, wherein said lens card includes a flat lens holder surrounding a single imaging lens.

8. The optical assembly of claim 7, wherein said single imaging lense is shaped to have an aspect ratio of between 3:

1 and 8;

1.

9. The optical assembly of claim 7, wherein said single imaging lens is positioned approximately 39 millimeters away from said solid state imager assembly.

10. The optical assembly of claim 1, wherein each of said lamp brackets carries two LEDs.

11. The optical assembly of claim 10, wherein each LED includes a pair of electrically conductive prongs extending therefrom.

12. The optical assembly of claim 1, wherein said imager is a charge coupled device (CCD).

13. The optical assembly of claim 1, wherein said series of leads are electrically connected to a flexible ribbon connector.

14. The optical assembly of claim 1, wherein said series of leads comprise a plurality of pins.

15. The optical assembly of claim 14, wherein said series of leads comprises between eleven and twenty-two pins.

16. The optical assembly of claim 1, wherein said support frame is molded from plastic.

17. The optical assembly of claim 1, further comprising an elongated optical element mounted forward of said pair of lamp brackets.

18. The optical assembly of claim 17, wherein said elongated optical element includes a central aperture, and wherein said elongated optical element is oriented to allow light to pass optically undisturbed through said central aperture toward said imager.

19. The optical assembly of claim 18, wherein said elongated optical element further includes a lens element disposed on at least one side of said central aperture.

20. An optical assembly for use in an optical reader, said optical assembly comprising:

a support frame;

a receive optical axis;

a pair of lamp brackets disposed at either side of said frame, each lamp bracket including a platform carrying a pair of LED clips and a field stop including a front wall and an elongated horizontal rectangular aperture;

a pair of LEDs mounted in said LED clips of said each lamp bracket, wherein body portions of said pair of LEDs of said each bracket define inner and outer LED boundary lines, and said LEDs are disposed so that LED boundary lines of said each lamp bracket extend through said field stop; and

a cylindrical lens surface disposed forward of said each field stop, said cylindrical lens surface imaging said each field stop onto a target; and

an imager assembly of the type comprising an imager and a support, said imager assembly disposed on said support frame and oriented perpendicular to said receive optical axis.

21. The optical assembly of claim 20, wherein said optical assembly further includes an imaging lens assembly, wherein said support frame includes a rear housing containing said imager assembly, wherein said support frame further includes wall-shaped arms integrally formed with said rear housing and extending forwardly from said rear housing, and wherein said optical assembly is received between said wall-shaped arms.

22. The optical assembly of claim 20, wherein said support frame includes a back wall, said back wall having spaced apart receiving surfaces receiving outer regions of a back surface of said support of said imager assembly.

23. The optical assembly of claim 20, further comprising a single piece optical element including at least one of said cylindrical lens surfaces imaging said field stops onto a target, said optical element having a center aperture centered on said receive optical axis.

24. The optical assembly of claim 20, wherein said receive optical axis is unfolded.

25. An optical assembly for use in an optical reader having a receive optical axis, said optical assembly comprising:

a support frame having a rear housing containing a solid state imager assembly of the type comprising an imager, a support, and a series of leads, wherein said rear housing includes a back surface receiving said imager assembly;

first and second light units disposed on either side of said receive optical axis;

first and second field stops, wherein said first field stop is disposed optically forwardly of said first light unit, and wherein said second field stop is disposed optically forward of said second light unit; and

a single piece optical element received on said support frame disposed to image said first and second field stops onto a target, said single piece optical element having a center aperture centered on said receive optical axis.

26. The optical assembly of claim 25, wherein said support frame further includes a pair of wall-shaped arms integrally formed with said rear housing and extending forwardly from said rear housing.

28. The optical assembly of claim 25, wherein said receive optical axis is unfolded.

27. The optical assembly of 25, wherein said first and second field stops include respective first and second elongated horizontal apertures, wherein each light unit includes a pair of LEDs, and wherein LED boundary lines defined by body portions of said each pair of LEDs extended through said respective first and second apertures.

29. An optical assembly for use in an optical reader, said optical assembly comprising:

an imager assembly including an imager;

a receive optical axis extending perpendicularly from said imager;

first and second light units disposed on either side of said receive optical axis;

first and second field stops, wherein said first field stop is disposed optically forward of said first light unit, and wherein said second field stop is disposed optically forward of said second light unit;

at least one optical element disposed to image light from said at least one of said first and second field stops onto a target, wherein said at least one optical element has formed thereon at least one single axis diffuser homogenizing light in a horizontal plane, said at least one single axis diffuser having a variable diffractive coefficient and an aperture aligned with said imager assembly such that light passes optically undisturbed from the target barcode to said imager assembly; and

a support frame supporting at least one of said imager assembly and said optical element.

30. The optical assembly of claim 29, wherein said at least one optical element is a single piece member imaging each of said respective field stops onto a target, and aperture extends through said single piece member along said receive optical axis.

31. The optical assembly of claim 29, wherein said at least one optical element imaging said first and second field stops onto said target and includes first and second single axis diffuser surfaces, each single axis diffuser surface homogenizing light from one of said light units in a horizontal plane and having a variable diffractive coefficient and including a percentage of diffusion greater at an inner edge thereof than an outer edge.

32. The optical assembly of claim 29, wherein said first and second field stops include respective first and second elongated horizontal apertures, wherein each light unit includes a pair of LEDs, and wherein LED boundary lines defined by body portions of said each pair of LEDs extend through said respective first and second apertures.

33. The optical assembly of claim 29, wherein said receive optical axis is unfolded.