Optical code reader for producing video displays and measuring physical parameters of objects

• US 6,336,587 B1
• Filed: 10/19/1998
• Issued: 01/08/2002
• Est. Priority Date: 10/19/1998
• Status: Expired due to Term

• Current Assignee: Symbol Technologies, LLC (Zebra Technologies Corporation)
• Original Assignee: Symbol Technologies, Inc. (Zebra Technologies Corporation)
• Inventors: He, Duanfeng, Joseph, Eugene, Shepard, Howard
• Primary Examiner(s): Frech, Karl D.
• Application Number:
  US09/174,466
• Time in Patent Office: 1,177 Days
• Field of Search: 235/462.45, 235/462.22, 235/462.23, 235/462.24, 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 and for use in motion detection surveillance using video compression and narrow band width communication links. An optical system including a plane parallel plate may be employed to change the system focal distance. The imaging optical code reader is also adapted for measurement of physical parameters of a target object including motion, distance, weight and dimensions.

Claims

1. 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 and having a open first sector radially outwardly located from the rotation axis through which optical codes are read, the carrier having a second sector located radially outwardly of the axis, said second sector containing a substantially transparent plate, 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 handheld optical code reader; and

means for rotating the carrier for selectively positioning a selected one of first and said second sectors in the optical path.

2. The optical system of claim 1, wherein the second sector contains a plano glass plate which increases the focal distance of the optical system.

3. The optical system of claim 1, further comprising:

a third sector located radially outwardly of said axis and selectively positionable in the optical path of the system and containing a first monochrome filter; and

a fourth sector located radially outwardly of said axis and selectively positionable in the optical path of the system, containing a second, different monochrome filter, wherein the monochrome filter are employed to obtain image data to produce color video display.

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

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

a fifth sector located radially outwardly of said axis and selectively positionable in the optical path of the system, containing an optical band pass filter approximately centered on a wavelength of the projected pattern.

5. The optical system of claim 4, further comprising means for monitoring the rotation of the carrier in response to the detection of the fifth sector being rotated into the optical path.

6. The optical system of claim 1, wherein the carrier is a wheel rotatable about a central axis thereof and divided into plural angular sectors, at least one of which sector being adapted for positioning in the optical path for imaging an optical code in a working depth of field of the optical code reader and at least two other sectors being adapted for focusing images on the image sensor from which a color video signal is derived.

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; and

a transparent optical element with substantially parallel, planar surfaces, selectively movable into the optical path of the image sensor;

wherein the system has a 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 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 located in a sector of a rotatable wheel located between the objective lens assembly and the image sensor.

10. An optical system for an optical code reader including an area 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 area image sensor;

a transparent plate with a single thickness selected to achieve a desired substantial change in the focal distance of the system when the plate is positioned in the optical path; and

a movable carrier for selectively positioning the transparent plate in the optical path to provide a desired longer focal distance for focusing a relatively distant image on the area image sensor and for selectively positioning the transparent plate out of the optical path to provide a desired shorter focal distance for focusing an image of an optical code on the area image sensor.

11. The optical system of claim 10, wherein the transparent plate is placed in the optical path to change the focal distance of the optical system to a focal distance more appropriate for producing video images.

12. The optical system of claim 10, wherein the transparent plate is placed in the optical path to change the focal distance of the optical system to a focal distance more appropriate for imaging a more distant bar code.

13. The optical system of claim 10, wherein the moveable carrier for selectively positioning the transparent plate includes a wheel rotatable about a central axis thereof and divided into plural angular sectors, at least one of which sectors contains the transparent plate.

14. 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; and

a transparent optical element with substantially parallel, planar surfaces, selectively movable into and out of the optical path between the objective lens assembly and the image sensor;

wherein the system has a focal distance adapted for imaging code symbols relatively near to the objective lens assembly and another focal distance for imaging at distances 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.

15. The optical system of claim 14, wherein the system operates in a hyper-focal mode when the optical element is moved into the optical path of the image sensor.

16. The optical system of claim 14, wherein the optical element is a glass plate located in a sector of a rotatable wheel located between the objective lens assembly and the image sensor.

17. The optical system of claim 14, wherein said another focal distance is selected for imaging scenes relatively far from the objective lens assembly.

18. The optical system of claim 14, wherein said another focal distance is selected for imaging bar codes relatively far from the objective lens assembly.