CCD-based bar code scanner

• US 6,296,187 B1
• Filed: 11/12/1999
• Issued: 10/02/2001
• Est. Priority Date: 11/12/1999
• Status: Expired due to Fees

• Current Assignee: SICK Incorporated (Sick)
• Original Assignee: PTO (Safe Fleet Holdings LLC)
• Inventors: Shearer, Frank W.
• Primary Examiner(s): Frech, Karl D.
• Application Number:
  US09/438,382
• Time in Patent Office: 690 Days
• Field of Search: 235/462.01, 235/462.11, 235/462.32, 235/462.41, 235/462.24, 235/462.1, 235/462.75
• US Class Current: 235/462.41
• CPC Class Codes: G06K 7/10722 Photodetector array or CCD scanning
• 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 bar code scanning system for a conveyor system includes a CCD camera that writes data to a memory. Data is stored in the memory as a two-dimensional image at periodic time frames based on scanning by the CCD camera. Data is written out of the memory by a controller, to create a virtual X-scan pattern, that can be read and decoded by a decoder that is configured to decode X-scan patterns. Alternatively, the memory can be configured as a first memory region for receiving even pixel data, and a second memory region for receiving odd pixel data.

Claims

1. An apparatus for scanning a bar code label, comprising:

at least one CCD camera configured to provide a linear array of scan output corresponding to a particular region currently being scanned;

a memory for storing the linear array of scan output from the at least one CCD camera;

a controller connected to the at least one CCD camera and configured to output the linear array of scan output to a particular region of the memory;

a signal processor connected to the memory and configured to output data from particular memory locations of the memory so as to create at least one virtual scan line; and

a decoder configured to determine if data corresponding to the virtual scan line corresponds to a real bar code,

wherein the virtual scan lines correspond to two 45 degree lines that intersect with each other so as to form an X-shape scan pattern, as well as a horizontal line that provides redundancy data for the decoder.

2. The apparatus according to claim 1, wherein the controller provides a write location signal to the signal processor, indicating where in the memory the controller is currently writing to.

3. An apparatus for scanning a bar code label, comprising:

at least one CCD camera configured to provide a linear array of scan output corresponding to a particular region being scanned;

a memory for storing the linear array of scan output from the at least one CCD camera, the memory being divided into a first memory region for storing even rows of pixel data and a second memory region for storing odd rows of pixel data with respect to pixels of the at least one CCD camera;

a controller connected to the at least one CCD camera and configured to output the linear array of scan output to the memory;

a signal processor connected to the memory and configured to output data from particular memory locations of the memory so as to create at least one virtual scan line;

an input FIFO unit that includes an even input FIFO unit for receiving the even row of pixel data from the even pixels of the at least one CCD camera, and an odd input FIFO unit for receiving the odd rows of pixel data from the odd pixels of the at least one CCD camera; and

a decoder configured to determine if data corresponding to the virtual scan line corresponds to a real bar code,

wherein the first memory region is further subdivided into a first even pixel bank and a first odd pixel bank,

wherein the second memory region is further subdivided into a second even pixel bank and a second odd pixel bank,

wherein consecutive frames of camera data output by the even input FIFO unit are alternately stored, on a frame by frame basis, in the first even pixel bank and the second even pixel bank, and

wherein consecutive frames of camera data output by the odd input FIFO are alternately stored, on a frame by frame basis, in the first odd pixel bank and the second odd pixel bank.

4. The apparatus according to claim 3, further comprising:

a tri-state buffer unit that includes an even tri-state buffer unit and an odd tri-state buffer unit; and

an output FIFO unit that includes an even output FIFO unit for receiving even pixel data from the first memory region via the even tri-state buffer, and an odd FIFO unit for receiving odd pixel data from the second memory region via the odd tri-state buffer,

data being sent to the output FIFO unit under control of the controller.