Adjustable illumination system for a barcode scanner

• US 6,164,544 A
• Filed: 07/08/1998
• Issued: 12/26/2000
• Est. Priority Date: 07/08/1998
• Status: Expired due to Term

• Current Assignee: Welch Allyn Incorporated
• Original Assignee: Welch Allyn Incorporated
• Inventors: Hunter, Vivian L., McCall, Melvin D., Jovanovski, Brian L., Schwartz, Eric D., Beckhusen, Gerard F., Hubben, Edward B.
• Primary Examiner(s): Le, Thien M.
• Assistant Examiner(s): Felten, Daniel S
• Application Number:
  US09/111,583
• Time in Patent Office: 902 Days
• Field of Search: 235/472.01, 235/462.45, 235/462.2, 235/462.4, 235/462.32, 235/462.33, 235/462.41, 235/483
• US Class Current: 235/462.43
• CPC Class Codes: G06K 7/10732 Light sources
• CPC Class Codes: G06K 7/10742 including a diffuser for diffusing the light from the light source to create substantially uniform illumination of the target record carrier

Abstract

These and other objects of the present invention are attained by apparatus for adjusting the position of a line of light in barcode space that includes a support frame having a rear housing containing a solid state imager and a pair of support arms extending forwardly from the front of the housing. An imaging lens is mounted between the arms for focusing an image of a target in barcode space upon the solid state imager along the optical axis of the imaging lens. Illuminating LEDs are mounted on either side of the imaging lens for illuminating the target. The illumination is passed through a pair of cylindrical lenses that are adjustably mounted upon the distal ends of the arm so that the light can be selectively positioned in barcode space.

Claims

1. Apparatus for adjusting the position of a line of light in barcode space that includes

a support frame having a rear housing containing a solid state imager,

an imaging lens supported in said frame for focusing an image of a target in barcode space along a linear optical axis of the solid state imager,

an illumination means supported in said frame for projecting a line of light upon a target in barcode space,

said illumination means including at least one cylindrical illumination lens element having a plano light entrance face that is mounted adjacent a light source, said light source being in coplanar alignment with said imaging lens, and being perpendicular to said optical axis and including a second circular light emitting face,

a field stop aperture positioned between the light source and the illumination lens for producing a line of light in barcode space, and

adjusting means for positioning the light entrance face of the illumination lens in relation to said source so that the line of light can be selectively positioned in barcode space, said adjusting means further including an arcuate shape recess formed in said cylindrical lens that is arranged to ride in contact with at least one cam mounted in said frame.

2. The apparatus of claim 1, wherein the arcuate shaped recess formed in the cylindrical lens element has a center of curvature that is coincidental with the center of curvature of the semi-circular light emitting face of the illumination lens element.

3. The apparatus of claim 1, wherein said light source further includes a plurality of light emitting diodes.

4. The apparatus of claim 1 wherein said illumination lens element further includes a single axis diffuser mounted at the plano light entrance face.

5. Apparatus for adjusting the position of a line of light in barcode space that includes

a support frame having a rear housing containing a solid state imager and a pair of arms extending forwardly from the housing,

an imaging lens mounted between the arms for focusing an image of a target in barcode space along a linear optical path onto said solid state imager,

illumination means mounted upon said frame containing a plurality of light emitting diodes located on either of said imaging lens in coplanar alignment with said imaging lens and being perpendicular to said optical path for illuminating a target in barcode space,

an elongated optical element that contains a pair of spaced apart cylindrical illumination lenses, said illumination lenses being located on either side of the optical path between the light emitting diodes and the target, each illumination lens containing a plano light entrance face and a semi-circular light exit face, said optical element having a central opening that passes through the optical path wherein a light image of said target passes through said opening,

each of said arms contains an arcuate camming surface at its distal end that is adapted to ride in a complementary recess formed in the optical element,

a field stop mounted between said light emitting diodes and the optical element producing a line of light in barcode space, and

adjusting means for rotatable positioning said optical element about its axis to adjust the position of the line of light in barcode space.

6. The apparatus of claim 5 whereby the arcuate shaped recess has a center of curvature that is coincidental with the center of curvature of the light exit face of the optical illumination element.

7. The apparatus of claim 6 wherein the camming surfaces each lie in a plane that is generally parallel with the optical path.

8. The apparatus of claim 7 that further includes means for securing the optical element to the frame arms in a desired position with respect to the optical path.

9. The apparatus of claim 8 wherein the means for securing the optical element to the frame arms includes one or more ultrasonic welds.