OPTICAL READER HAVING IMAGE SENSOR FOR READING DECODABLE INDICIA

• US 20090039163A1
• Filed: 06/13/2008
• Published: 02/12/2009
• Est. Priority Date: 03/04/1994
• Status: Active Grant

• Current Assignee: Hand Held Products Incorporated (Honeywell International Inc.)
• Original Assignee: Hand Held Products Incorporated (Honeywell International Inc.)
• Inventors: Pidhirny, John M., Hussey, Robert M., Longacre, Andrew JR.
• Granted Patent: US 8,397,992 B2
• Time in Patent Office: Days
• US Class Current: 235/462.250
• CPC Class Codes: G06K 17/0022 arrangements or provisious for transferring data to distant stations, e.g. from a sensing device "transfer between computer elements G06F13/00 "; data-transmission H04L
• CPC Class Codes: G06K 19/06037 multi-dimensional coding
• CPC Class Codes: G06K 2207/1017 Programmable
• CPC Class Codes: G06K 7/10544 by scanning of the records by radiation in the optical part of the electromagnetic spectrum
• CPC Class Codes: G06K 7/10821 further details of bar or optical code scanning devices
• 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 7/14 using light without selection of wavelength, e.g. sensing reflected white light G06K7/10831 - G06K7/1097 take precedence
• CPC Class Codes: G06K 7/1491 the method including a reconstruction step, e.g. stitching two pieces of bar code together to derive the full bar code

Abstract

An optical reader for reading decodable indicia is provided. In one embodiment, the optical reader can include an image sensor. In one aspect, the optical reader can be configured to read bar codes such as 1D bar codes. Particular methods and apparatus for reading decodable indicia are described.

Claims

1. A method for decoding a bar code symbol, said method comprising the steps of:

providing a bar code reader having a plurality of light emitting diodes for illumination of said bar code symbol and an image sensor, wherein said providing step further includes the step of providing focusing optics for causing light returning from said bar code symbol to be focused on said image sensor, wherein said providing step further includes the step of providing a memory that includes both a timercount and an image memory space;

enabling initiation of scanning and timing mechanisms in response to a trigger press;

generating, using said bar code reader, a video signal for a succession of slices of said bar code symbol;

converting each of said succession of slices into a timercount representation, and storing each of said timercount representations into successive locations of said timercount memory space;

converting each of said succession of timercount representations into a bit representation to form a set of bit representations;

storing each of said set of bit representations into said image memory space;

circulating data of said timercount memory space if said timercount memory space becomes full;

circulating data of said image memory space if said image memory space becomes full;

attempting to decode said bar code symbol as a 1D symbol utilizing at least one of said set of timercount representations;

examining said set of bit representations for inclusion of a 2D symbol finder pattern;

if said 2D symbol finder pattern is present, transferring said set of bit representations stored in said image memory space to said timercount memory space during the course of reorganization of data of said image memory space, wherein said transferring step includes the step of overwriting the data of said timercount memory space; and

decoding said bar code symbol as a 2D symbol utilizing said set of bit representations.

2. The method for decoding a bar code symbol of claim 1, wherein said providing step includes the step of providing a bar code reader that is adapted to image a 1D slice of said bar code symbol.

3. The method for decoding a bar code symbol of claim 1, wherein said providing step includes the step of providing a 1D image sensor.

4. The method for decoding a bar code symbol of claim 1, wherein said method further includes the step of utilizing said set of timercount representations for attempting to decode said bar code symbol as a 1D stacked bar code symbol.

5. The method for decoding a bar code symbol of claim 1, wherein said image sensor develops analog signals that represent the optically readable content of a complete slice of said bar code symbol.

6. The method for decoding a bar code symbol of claim 1, wherein said method further includes the step of disabling said scanning and timing mechanism if said trigger is not still depressed.

7. The method for decoding a bar code symbol of claim 1, wherein said providing step includes the step of providing a Static Random Access Memory (SRAM).

8. A bar code scanner for use in reading a bar code disposed on a target, said bar code scanner comprising:

a scanning section comprising an illuminator, optics, an image sensor and signal processing electronics, the illuminator comprising an LED array and producing a light beam that strikes a target having a bar code, said optics projecting an image of said bar code onto said image sensor, said image sensor developing signals responsive to light incident thereon, said signal processing electronics outputting a conditioned video signal;

a microcomputer in communication with said scanning section, said microcomputer having a direct memory access controller and an I/O port for providing communication with a telecommunications network, said bar code scanner being adapted so that said microcomputer asserts an enable signal to turn on said illuminator and said image sensor responsively to one of a presence of indicia or to an actuation of a manual trigger;

a random access memory, wherein said bar code scanner is adapted so that said direct memory access controller mediates transfer of said conditioned video signal to said random access memory;

a first memory location for retaining first scan information transferred therein from said scanning section during a first scan; and

a second memory location for retaining second scan information transferred therein from said scanning section during a second scan;

wherein said bar code scanner is adapted so that storage of information is accomplished using two predetermined blocks of memory wherein each block is of sufficient size to accommodate the greatest possible information obtainable from a single scan;

wherein said bar code scanner is adapted so that said bar code scanner determines if said first scan is completed and wherein said bar code scanner is adapted to decode said bar code;

wherein said bar code scanner is adapted so that said bar code scanner attempts to decode said bar code using said first scan if said bar code scanner determines that said first scan is completed;

wherein said bar code scanner is adapted so that said bar code scanner awaits completion of decoding of said first scan before initiating an additional scan;

wherein said bar code scanner is adapted to determine whether a decode is successful by (a) determining whether decoding has been completed, and (b) determining whether a valid decode has been accomplished; and

wherein said bar code scanner is further adapted so that said bar code scanner further determines whether said bar code scanner has successfully decoded a group of scans.

9. The bar code scanner of claim 8, wherein said image sensor is a CCD image sensor.

10. The bar code scanner of claim 8, wherein said image sensor is a CCD array.

11. The bar code scanner of claim 8, wherein said image sensor is a CCD matrix.

12. The bar code scanner of claim 8, wherein said microcomputer is coupled to said manual trigger via an I/O port section.

13. The bar code scanner of claim 8, wherein said microcomputer asserts said enable signal responsively to said presence of said indicia.

14. The bar code scanner of claim 8, wherein said microcomputer asserts said enable signal responsively to said actuation of said manual trigger.

15. The bar code scanner of claim 8, wherein said bar code scanner is adapted to time said video out signal using clock counts as a reference.