Method of automatically reading code symbols on objects present within the field of view (FOV) of a hand-supportable digital-imaging based code symbol reader, by simultaneously projecting an image cropping zone (ICZ) framing pattern and a field of illumination within the FOV during object illumination and imaging operations

• US 7,624,926 B2
• Filed: 11/29/2006
• Issued: 12/01/2009
• Est. Priority Date: 11/13/2003
• Status: Expired due to Term

• Current Assignee: Metrologic Instruments Incorporated (Honeywell International Inc.)
• Original Assignee: Metrologic Instruments Incorporated (Honeywell International Inc.)
• Inventors: Zhu, Xiaoxun, Au, Ka Man, Liu, Yong, Liu, Liang, Kotlarsky, Anatoly, Tao, Xi, Zhang, Wenhua, Hou, Rui, Yu, Hongpeng
• Primary Examiner(s): Kim; Ahshik
• Application Number:
  US11/605,854
• Publication Number:
  US 20070158427A1
• Time in Patent Office: 1,098 Days
• Field of Search: 235/462.22, 235/462.01, 235/462.09, 235/462.31, 235/462.42
• US Class Current: 235/462.22
• CPC Class Codes: G06F 9/44526 Plug-ins; Add-ons
• CPC Class Codes: G06K 2207/1012 Special detection of object
• CPC Class Codes: G06K 7/10712 Fixed beam scanning
• CPC Class Codes: G06K 7/10732 Light sources
• CPC Class Codes: G06K 7/10831 Arrangement of optical elements, e.g. lenses, mirrors, prisms optical elements per se G02B
• CPC Class Codes: G06K 7/10851 Circuits for pulse shaping, amplifying, eliminating noise signals, checking the function of the sensing device basic electronic circuitry H03
• CPC Class Codes: G06K 7/10881 constructional details of hand-held scanners
• CPC Class Codes: G06K 7/14 using light without selection of wavelength, e.g. sensing reflected white light G06K7/10831 - G06K7/1097 take precedence

Abstract

A hand-supportable digital-imaging based system for reading bar code symbols involving: automatically detecting the presence of an object within a field of view FOV of the system, and in response thereto, automatically generating an image cropping zone (ICZ) framing pattern and projecting the ICZ framing pattern within the FOV and onto the detected object; visually aligning the code symbol on the detected object, within the ICZ framing pattern; manually actuating a trigger switch when the code symbol on the object is located within the ICZ framing pattern, and while the ICZ framing pattern and a field of illumination are being simultaneously projected onto the object during object illumination operations, forming and capturing a digital image of the code symbol on the detected object; automatically cropping the image pixels contained within the spatial boundaries of the ICZ framing pattern, from the pixels of the digital image; and decode processing the cropped image so as to read one or more 1D and/or 2D code symbols graphically represented therein.

Claims

1. A method of automatically reading code symbols on objects within the field of view of a hand-supportable digital-imaging based code symbol reader, said method comprising the steps of:

(a) bringing said hand-supportable digital imaging-based code symbol reader in proximity with an object bearing a code symbol, wherein said hand-supportable digital imaging-based code symbol reader includes (i) a hand-supportable housing having a trigger switch for generating a trigger signal in response to manual actuation of said trigger switch by an operator, (ii) an area-type image sensing array with a field of view (FOV) for detecting a digital image of the object within said FOV, (iii) an automatic object presence detector for detecting the object within said FOV, (iv) a LED-based illumination subsystem with an LED illumination array for illuminating the object within said FOV, (v) an image cropping zone (ICZ) framing pattern generator for generating an ICZ framing pattern by forming a pattern of visible illumination which is substantially encompassed within said FOV, and (vi) a programmed image processor for processing one or more digital images of the detected object;

(b) automatically detecting the presence of said object within said FOV using said automatic object presence detector;

(c) in response to the automatic detection of the object in said FOV, automatically generating the ICZ framing pattern from said ICZ framing pattern generator and projecting said ICZ framing pattern within said FOV and onto said detected object;

(d) visually aligning the code symbol on said detected object, within said ICZ framing pattern, for imaging the code symbol;

(e) manually actuating said trigger switch when the code symbol on said object is aligned within said ICZ framing pattern, so as to cause said LED-based illumination array to generate and project a field of illumination into said FOV and onto said detected object and throughout said ICZ framing pattern;

(f) while said ICZ framing pattern and said illumination pattern are being simultaneously projected onto said object, forming and detecting a digital image of the entire said FOV which embraces and encompasses said ICZ framing pattern and at least a portion of said detected object;

(g) using said programmed image processor for automatically locating said ICZ framing pattern in said digital image of the entire said FOV, by tracing corner points or border lines that identify boundaries of said ICZ framing pattern, and cropping the image pixels within the boundaries of said ICZ framing pattern, prior to performing decode-processing operations; and

(h) automatically decode processing the image pixels cropped in step (g) so as to read one or more 1D or 2D code symbols represented in the cropped image pixels.

2. The method of claim 1, which further comprises:

(i) producing symbol character data representative of the one or more 1D or 2D code symbols read during step (h), and outputting said symbol character data to a host system.

3. The method of claim 1, wherein step (c) comprises generating a visible laser beam which is transmitted through an optical element to produce a plurality of laser beamlets that define the spatial boundaries of said ICZ framing pattern for the operator to see and use for visual alignment purposes in step (d).

4. The method of claim 3, wherein said optical element comprises a light diffractive element to produce said plurality of laser beamlets.

5. The method of claim 3, wherein said optical element comprises a light refractive element to produce said plurality of laser beamlets.

6. The method of claim 1, wherein step (c) comprises generating a visible illumination beam from an LED-based source which is modified to produce a plurality of illumination components that serve to define the spatial boundaries of said ICZ framing pattern for the user to see and use during object illumination and imaging operations.

7. The method of claim 1, wherein during step (e), said illumination pattern is visible to the operator.

8. The method of claim 1, wherein said one or more 1D and/or 2D code symbols comprise one or more bar code symbols.

9. The method of claim 8, wherein each said bar code symbol is selected from the group consisting of 1D bar code symbols, 2D bar code symbols and data matrix symbols.

15. The method of claim 1, wherein during step (e), said field of illumination is visible to the operator.

10. A hand-supportable digital-imaging based code symbol reading system having wide-area illumination and image capturing modes operation, said hand-supportable digital-imaging based code symbol reading system comprising:

a hand-supportable housing having a trigger switch for manual actuation by an operator;

an image formation and detection subsystem, disposed within said hand-supportable housing, and having an image sensing array with a field of view (FOV);

an automatic object presence detector, disposed in said hand-supportable housing, for automatically detecting the presence of an object in said FOV;

an LED-based illumination subsystem with an LED illumination array, disposed within said hand-supportable housing;

an electro-optical mechanism, disposed within said hand-supportable housing, for projecting an image cropping zone (ICZ) framing pattern within said FOV on said detected object, wherein said ICZ framing pattern is formed by a pattern of visible illumination which is substantially encompassed within said FOV;

a programmed image processor, disposed within said hand-supportable housing, for automatically locating said ICZ framing pattern in said digital image of the entire said FOV, by tracing corner points or border lines that identify boundaries of said ICZ framing pattern, and for cropping image pixels within the boundaries of said ICZ framing pattern, and decode-processing these cropped image pixels so as to read one or more 1D and/or 2D code symbols represented in said cropped image pixels; and

a system control subsystem, disposed in said hand-supportable housing, for controlling and/or coordinating the subsystems and components described above;

wherein, in response to automatic detection of the object within said FOV by said automatic object presence detector,

(1) said ICZ framing pattern generator automatically generates and projects said ICZ framing pattern into the FOV and onto the detected object; and

(2) the operator is provided an opportunity to visually align a code symbol on the detected object, within said ICZ framing pattern; and

(3) when the operator has aligned the code symbol on the detected object, within said ICZ framing pattern, the operator manually actuates said trigger switch; and

(4) in response to the manual actuation of said trigger switch by said operator, said LED-based illumination subsystem automatically generates and projects a field of illumination into said FOV and onto said detected object and throughout said ICZ framing pattern, simultaneously when said ICZ framing pattern is being projected into said FOV and onto said detected object;

(5) in response to the generation of said illumination pattern, said image formation and detection subsystem forming and detecting a digital image of the entire FOV so that the detected digital image spatially encompasses said ICZ framing pattern aligned about at least a portion of the detected object being imaged; and

(6) said programmed image processor automatically (i) cropping the pixels within the spatial boundaries defined by said ICZ framing pattern, from those pixels contained in said digital image detected in step (5), prior to performing decode-processing operations, (ii) decode- processing the cropped image pixels so as to read one or more 1D and/or 2D code symbols graphically represented in said cropped image pixels, and (iii) outputting to a host system, symbol character data representative of the read one or more 1D and/or 2D code symbols.

11. The hand-supportable digital-imaging based bar code symbol reading system of claim 10, wherein said an optical-optical mechanism comprises a laser source for generating a visible laser beam which is transmitted through an optical element so as to produce a plurality of laser beamlets that define the spatial boundaries of said ICZ framing pattern for the user to see during object illumination and imaging operations.

12. The hand-supportable digital-imaging based code symbol reading system of claim 11, wherein said optical element comprises a light diffractive element to produce said plurality of laser beamlets.

13. The hand-supportable digital-imaging based code symbol reading system of claim 11, wherein said optical element comprises a light refractive element to produce said plurality of laser beamlets.

14. The hand-supportable digital-imaging based code symbol reading system of claim 10, wherein said electro-optical mechanism comprises an LED-based source for generating a visible illumination beam which is modified to produce a plurality of illumination components that define the spatial boundaries of said ICZ framing pattern for the user to see during object illumination and imaging operations.

16. The hand-supportable digital-imaging based code symbol reading system of claim 10, wherein said one or more 1D and/or 2D code symbols comprise one or more bar code symbols.

17. The hand-supportable digital-imaging based code symbol reading system of claim 16, wherein each said bar code symbol is selected from the group consisting of 1D bar code symbols, 2D bar code symbols and data matrix symbols.