Digital image capture and processing system supporting a periodic snapshot mode of operation wherein during each image acquisition cycle, the rows of image detection elements in the image detection array are exposed simultaneously to illumination

• US 7,845,561 B2
• Filed: 12/21/2007
• Issued: 12/07/2010
• 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, Veksland, Michael, Ren, Jie, Knowles, C. Harry, Au, Ka Man, Giordano, Patrick, Allen, Christopher, Yan, Weizhen, Smith, Taylor, De Foney, Shawn, Mandal, Sudhin, Wilz, David M. Sr., Kotlarsky, Anatoly, Miraglia, Michael V.
• Primary Examiner(s): Kim; Ahshik
• Application Number:
  US12/005,070
• Publication Number:
  US 20080283606A1
• Time in Patent Office: 1,082 Days
• Field of Search: 235/462.24, 235/462.01, 235/462.09, 235/462.15
• US Class Current: 235/462.24
• CPC Class Codes: G06K 7/10722 Photodetector array or CCD scanning
• CPC Class Codes: G06K 7/10732 Light sources
• CPC Class Codes: G06K 7/10752 Exposure time control
• CPC Class Codes: G06K 7/10821 further details of bar or optical code scanning devices
• CPC Class Codes: G06K 7/109 adaptations to make the hand-held scanner useable as a fixed scanner

Abstract

A digital image capture and processing system including a housing having an imaging window; and an image formation and detection subsystem supporting a periodic snap shot mode of the operation. The system includes image formation optics for projecting a field of view (FOV) through said imaging window and upon an object within the FOV, and forming an image of the object on an area-type image detection array having a plurality of rows of image detection elements, and detecting 2D digital images of the object while object illumination and imaging operations. The system also includes an LED-based illumination subsystem, with a LED illumination array, for producing a field of narrow-band illumination within the FOV, and illuminating the object detected in the FOV, so that the illumination reflects off the object and is transmitted back through the light transmission aperture and onto the image detection array to form the 2D digital image of the object. During the periodic snap shot mode of the operation, the image detection array supports periodic image acquisition cycles, and during each image acquisition cycle, substantially all image detection elements in the image detection array are exposed simultaneously to the illumination. In the illustrative embodiment, each image acquisition cycle has a predetermined time duration followed by a decode-processing cycle having a time duration approximately equal to the duration of the image acquisition cycle so that at least ten (10) image frames can be acquired per second.

Claims

1. A digital image capture and processing system comprising:

a housing having an imaging window;

an area-type image formation and detection subsystem, disposed in said housing, and having image formation optics for projecting a field of view (FOV) through said imaging window and an area-type image detection array having a plurality of rows of image detection elements and a periodic snap-shot mode of operation for forming and detecting a 2D digital image of the object during each image acquisition cycle of said area-type image detection array;

an LED-based illumination subsystem, disposed in said housing, including a LED illumination array for producing a field of illumination within said FOV, and illuminating said object detected in said FOV, so that said illumination reflects off said object and is transmitted back through a light transmission aperture and onto said area-type image detection array to form each said 2D digital image of said object;

an illumination control subsystem, disposed in said housing, for controlling the operation of said LED illumination array within said LED-based illumination subsystem;

wherein during said periodic snap shot mode of the operation, said area-type image detection array supports periodic image acquisition cycles;

wherein during each said image acquisition cycle, substantially all image detection elements in said area-type image detection array are exposed simultaneously to said illumination; and

wherein each said image acquisition cycle has a predetermined time duration followed by a decode-processing cycle having a decode time duration approximately equal to the duration of said image acquisition cycle;

an image capturing and buffering subsystem, disposed in said housing, for capturing and buffering 2D digital images detected by said area-type image formation and detection subsystem;

wherein during each said image acquisition cycle, (i) said rows in said area-type image detection array are reset, (ii) then said rows are simultaneously exposed to illumination produced by said LED-based illumination subsystem while controlled by said illumination control subsystem, and (iii) then pixel data from said area-type image detection array is transmitted to said image capturing and buffering subsystem;

a digital image processing subsystem for processing 2D digital images captured and buffered by said image capturing and buffering subsystem and reading 1D and 2D bar code symbols graphically represented in said 2D digital images;

an input/output subsystem, disposed in said housing, for outputting processed image data to an external host system or other information receiving or responding device; and

a system control subsystem, disposed in said housing, for controlling and/or coordinating said subsystems during object illumination and imaging operations.

2. The digital image capture and processing system of claim 1, which further comprises

an automatic object detection subsystem, disposed in said housing, for automatically detecting the presence of the object within said FOV and generating a trigger event signal;

and

an object targeting illumination subsystem, disposed in said housing, for generating and projecting a targeting illumination beam within a central portion of said FOV, in response to the generation of said trigger event signal;

wherein said targeting illumination beam is momentarily switched off while said LED illumination array is producing said field of illumination within said FOV and said area-type image detection array is detecting 2D digital images of said detected object within said FOV, during object illumination and imaging operations.

3. The digital image capture and processing system of claim 2, wherein at least ten (10) digital image frames of said detected object are acquired per second.

4. The digital image capture and processing system of claim 2, wherein said targeting illumination beam is automatically generated from said object targeting illumination subsystem is response to the generation of said trigger event signal.

5. The digital image capture and processing system of claim 3, wherein said targeting illumination beam is a linear targeting illumination beam that is projected through a central region of said FOV.

6. The digital image capture and processing system of claim 1, which further comprises:

a manually-actuatable trigger switch integrated with said housing, for generating a trigger event signal;

wherein in response to generation of said trigger event signal, said LED illumination array produces said field of illumination within said FOV, and said area-type image detection array detects 2D digital images of said detected object within said FOV, during object illumination and imaging operations.

7. The digital image capture and processing system of claim 1, wherein said predetermined time duration is approximately 30 milliseconds.

8. The digital image capture and processing system of claim 1, wherein the time duration of each said image acquisition cycle is approximately 30 milliseconds, and wherein the decode time duration of each said decode-processing cycle is also approximately 30 milliseconds.

9. The digital image capture and processing system of claim 1, wherein said field of illumination is a field of narrow-band illumination, and wherein a high-pass optical filter element is embodied within said imaging window, and a low-pass optical filter element is disposed before said area-type image detection array, and wherein said high-pass and low-pass optical filter elements optically cooperate to form a narrow-band optical filter subsystem for transmitting substantially only the very narrow band of wavelengths of narrow-band illumination produced from said LED-based illumination subsystem and reflected/scattered off the illuminated object, while rejecting all other optical wavelengths outside said narrow optical band.

10. The digital image capture and processing system of claim 1, wherein said housing is capable of being supported within the hand of an operator.

11. The digital image capture and processing system of claim 1, wherein housing capable of being supported on a countertop surface.

12. A digital image capture and processing system comprising:

a housing having an imaging window;

an area-type image formation and detection subsystem, disposed in said housing, and having image formation optics for projecting a field of view (FOV) through said imaging window and an area-type image detection array having a plurality of rows of image detection elements and a periodic snap-shot mode of operation for forming and detecting a 2D digital image of the object during each image acquisition cycle of said area-type image detection array;

an LED-based illumination subsystem, disposed in said housing, including a LED illumination array for producing a field of illumination within said FOV, and illuminating said object detected in said FOV, so that said illumination reflects off said object and is transmitted back through a light transmission aperture and onto said area-type image detection array to form said 2D digital image of said object;

an illumination control subsystem, disposed in said housing, for controlling the operation of said LED illumination array within said LED-based illumination subsystem;

wherein during said periodic snap shot mode of the operation, said area-type image detection array supports periodic image acquisition cycles;

wherein during each said image acquisition cycle, substantially all image detection elements in said area-type image detection array are exposed simultaneously to said illumination; and

wherein each image acquisition cycle has a predetermined time duration followed by a decode-processing cycle having a decode time duration approximately equal to the duration of said image acquisition cycle;

an image capturing and buffering subsystem, disposed in said housing, for capturing and buffering 2D digital images detected by said area-type image formation and detection subsystem; and

a digital image processing subsystem for processing 2D digital images captured and buffered by said image capturing and buffering subsystem and reading 1D and 2D bar code symbols graphically represented in said 2D digital images.

13. The digital image capture and processing system of claim 12, wherein at least ten (10) image frames of said detected object are acquired per second.

14. The digital image capture and processing system of claim 12, which further comprises

an automatic object detection subsystem, disposed in said housing for automatically detecting the presence of an object within said FOV and generating a trigger event signal;

and

an object targeting illumination subsystem, disposed in said housing, for generating and projecting a targeting illumination beam within a central portion of said FOV, in response to the generation of said trigger event signal; and

wherein said targeting illumination beam is momentarily switched off while said LED illumination array is producing said field of illumination within said FOV and said area-type image detection array is detecting 2D digital images of said detected object within said FOV, during object illumination and imaging operations.

15. The digital image capture and processing system of claim 14, wherein said targeting illumination beam is automatically generated from said object targeting illumination subsystem is response to the generation of said trigger event signal.

16. The digital image capture and processing system of claim 12, which further comprises:

a manually-actuatable trigger switch integrated with said housing, for generating of a trigger event signal; and

wherein in response to the generation of said trigger event signal, said LED illumination array produces said field of wide-area illumination within said FOV and said area-type image detection array detects 2D digital images of said detected object within said FOV, during object illumination and imaging operations.

17. The digital image capture and processing system of claim 12, wherein said predetermined time duration is approximately 30 milliseconds.

18. The digital image capture and processing system of claim 12, wherein the predetermined time duration of each said image acquisition cycle is approximately 30 milliseconds, and wherein the decode time duration of each said decode-processing cycle is also approximately 30 milliseconds.

19. The digital image capture and processing system of claim 12, wherein said housing is capable of being supported within the hand of an operator.

20. The digital image capture and processing system of claim 12, wherein said housing is capable of being supported on a countertop surface.