Optical code reader for producing video displays

• US 6,766,955 B2
• Filed: 06/05/2001
• Issued: 07/27/2004
• 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: Patel, Mehul, He, Duanfeng, Joseph, Eugene, Correa, Mark
• Primary Examiner(s): Frech, Karl D.
• Application Number:
  US09/873,302
• Publication Number:
  US 20010027995A1
• Time in Patent Office: 1,148 Days
• Field of Search: 235/375, 235/380, 235/454, 235/467.01, 235/467.13, 235/467.08, 235/467.09, 235/467.2, 235/467.21, 235/467.3, 235/467.31, 235/467.45, 235/467.46, 235/467.48, 235/472.01, 235/472.02
• 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.

Claims

1. An optical code decoding system comprising:

an imagina apparatus for obtaining and displaylng video image signals comprising;

a handhold optical code reader including a two dimensional image sensor having means for outouting image data and video data at at least three frames per second said handhold optical code reader further including means for compressing said video data output from the image sensor;

a host terminal with a communication port and display;

a narrow band width data link over which compressed video data from the handheld optical code reader are communicated to a communication port of the host terminal; and

at least one processor for decoding an ontical code cantured by at least the video data.

2. The system of claim 1, wherein the imaging apparatus further comprises means for detecting acomniand bar code for switching the handheld optical code reader between an optical code reading mode and a video data communication mode.

3. The system of claim 1, wherein the handheld optical code reader includes a microprocessor and output driver for communication with the host terminal, and wherein the host terminal is a computer with a serial communication port for receiving the compressed video data and for receiving decoded information from optical codes read by the handheld code reader.

4. The system of claim 1, wherein the narrow band width data link is a cable connected between the handbeld optical code reader and a serial communication port of the host terminal.

6. The system of claim 1, wherein the narrow band width data link is an infrared transmitter and receiver.

7. The system of claim 1, wherein the imaging apparatus further comprising means for detecting motion in a field of view of the handheld optical code reader.

8. The system of claim 7, wherein motion is detected by monitoring the bandwidth of the compressed video signal.

9. The system of claim 1, wherein the handheld optical code reader further includes:

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

a carrier rotatable about an axis and having a sector radially outwardly located from the rotation axis through which optical codes are read, the caniar 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 objective lens to a focal distance more appropriate for producing video images with the handheld optical code reader; and

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

10. The system of claim 9, wherein the first sector is open and the second sector contains a piano glass optical element which increases the focal distance of the optical system.

11. The system of claim 9, 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 selcetively positionable in the optical path of the system, containing a second, different monochrome filter, wherein the monochrome filters are employed to obtain image data to produce a color video display.

12. The system of claim 11, further comprising:

a laser pattern projector for projecting pattern from the hazidheld 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 filler approximately centered on a wavelength of the projected pattern.

13. The system of claim 12, 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.

14. The system of claim 9, whcreia the carrier is a wheel rotatable about a central axis thereof and divided into plural angular setcors, 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 focnsing images on the image sensor from which a color video signal is derived.

15. The system of claim 1, wherein the at least one processor further measures a physical parameter of an object from the image data and/or video data.

5. The system of lcaim 1, wherein the narrow band width data link is a radio frequency transmitter and receiver.

16. A method for reading an optical code disnosed on an object and obtainian at least onc ohvsicai nararneter of said object, comprising the steps of:

providing an optical code reader configured for acquiring image data and video data at at least three frames per second; and

performing motion detection using an the optical code reader comprising the steps of;

positioning an image sensor of the optical code reader so that a field of view of the image sensor includes a region to be monitored for motion;

switching the optical code reader from an optical code reading mode to video mode;

analysing video data in the field of view of the image sensor;

identifying changes between a set of frames of video data; and

monitoring thc frequency of the changes between the set of frames of video data to identify frequency changes indicative of the movement of objects of interest in the field of view.

17. The method of claim 16, further comprising the steps of:

compressing the video data from the image sensor;

transmitting the compressed video data from the optical code reader to a terminal; and

displaying tho image of the field or view of the image sensor at the terminal, and observing images at the terminal based on the detection of motion in the field of view.

18. The method of claim 16, further comprising the step of:

measuring orthogonal dimensions of a rectangular solid object in the field of view of the image sensor, comprising the steps of;

obtaining pixel information for the held of view of the image sensor;

determining a dislance between the object and the image sensor;

determining the angles between edges of the rectangular solid meeting at a nearest corner cif the object and dctcrmining an imaged length of edges of the rectangular solid to be measured from the pixel informiation; and

scaling the deerndned image length of the edges responsive to the determined angles and determined distance between the rectangular solid and the image sensor to obtain an approximation of the actual length of said edges.

19. The method of claim 18, wherein the distance between the object and the image sensor is determined from a detected image of an aiming pattern projected onto the object.

20. The method of claim 18, wherein the distance between the object and the image sensor is determined from at least one image dimension of an optical code symbol of known siae on the object.

21. The method of claim 18, wherein the image sensor is incornorated within an imaging optical code reader.