Rotating plate carrier for changing focal distance of optical code imager

• US 6,726,105 B2
• Filed: 06/05/2001
• Issued: 04/27/2004
• Est. Priority Date: 10/19/1998
• Status: Expired due to Fees

• Current Assignee: Symbol Technologies, Inc. (Zebra Technologies Corporation)
• Original Assignee: Symbol Technologies, Inc. (Zebra Technologies Corporation)
• Inventors: Poloniewicz, Paul, He, Duanfeng, Joseph, Eugene, Correa, Mark, Bianculli, Thomas, Patel, Mehul, Shepard, Howard
• Primary Examiner(s): Frech, Karl D.
• Application Number:
  US09/873,213
• Publication Number:
  US 20010032879A1
• Time in Patent Office: 1,057 Days
• Field of Search: 235/462.22, 235/462.23, 235/462.24, 235/462.45, 235/462.38, 235/462.39, 235/462.4
• US Class Current: 235/462.45
• CPC Class Codes: G06K 7/10861 sensing of data fields affixed to objects or articles, e.g. coded labels postal sorting B07C3/14, conveying articles B65G47/48
• CPC Class Codes: G07G 1/0054 with control of supplementary check-parameters, e.g. weight or number of articles
• CPC Class Codes: H04N 7/183 for receiving images from a single remote source

Abstract

An imaging optical code reader is adapted for use in producing video displays. A rotating plate carrier is capable of placing several different optical elements into the optical paths of the system including at least one plane parallel plate to change the system focal distance.

Claims

1. An optical system for an optical code reader including an image sensor, comprising:

an objective lens located in an optical path of the code reader for focusing an image of an optical code onto the image sensor;

a carrier rotatable about an axis and having a first sector radially outwardly located from the rotation axis through which the optical code is read, the carrier having a second sector located radially outwardly of the axis, said second sector containing an optical element, which when placed in the optical path changes the focal distance of the optical system to a focal distance more appropriate for producing video images with the optical code reader; and

means for rotating the carrier for selectively positioning and maintaining a selected one of said first and said second sectors in the optical path during an imaging operation of the optical code reader.

2. An optical system for a handheld optical code reader including an image sensor, comprising:

an objective lens located in an optical path of the code reader for focusing an image of an optical code onto the image sensor;

a carrier rotatable about an axis for carrying plural optical elements for selective positioning and maintaining in the optical path of the code reader one of said plural optical elements during an imaging operation, at least one of said optical elements comprising a substantially transparent plano plate, when one of said plural optical elements is placed in the optical path, the focal distance of the optical system changes;

means for rotating the carrier for positioning and maintaining said optical elements in the optical path.

3. The optical system of claim 2, further comprising:

an optical element carried by said rotatable carrier comprising a first monochrome filter.

4. The optical system of claim 3, further comprising another optical element carried by said rotatable carrier comprising a second, different monochrome filter, wherein the monochrome filters are employed to obtain image data to produce a color video display.

5. The optical system of claim 2, further comprising:

a laser pattern projector for projecting a pattern from the handheld optical code reader, and

an optical element carried by said rotatable carrier and selectively positionable in the optical path of the system comprising an optical band pass filter approximately centered on a wavelength of the projected pattern.

6. The optical system of claim 2, wherein the carrier is a wheel rotatable about a central axis thereof and divided into plural sectors each carrying an optical element, at least one of which optical elements being adapted for positioning in the optical path for imaging the optical code in a working depth of field of the optical code reader.

7. An optical system for an optical code reader comprising:

an area image sensor;

an objective lens assembly adapted and positioned for focusing an image onto the area image sensor;

a rotatable carrier; and

at least one transparent optical element with substantially parallel, planar surfaces, carried by said rotatable carrier and selectively movable into and maintainable within the optical path of the image sensor by said rotatable carrier during an imaging operation;

wherein the system has at least one focal distance adapted for reading code symbols relatively near to the objective lens assembly and another focal distance for imaging scenes relatively far from the objective lens assembly; and

wherein the thickness of the plate is selected to change the focal distance of the system between the one focal distance and the other.

8. The optical system of claim 7, wherein the system operates in a hyper-focal mode when the at least one optical element is moved into the optical path of the image sensor.

9. The optical system of claim 7, wherein the optical element is a glass plate selectively located between the objective lens assembly and the image sensor.

10. An optical imager with plural focal distances Z_R determined by the thickness of plural glass plates sequentially inserted in an optical path between an objective lens assembly and an area image sensor, wherein the plural glass plates have thicknesses selected on the basis of the desired focal distances Z_R and wherein the glass plates are located on a rotating carrier with an axis of rotation generally parallel to and offset from the optical path.