CCD-base bar code scanner

• US 5,984,186 A
• Filed: 10/29/1997
• Issued: 11/16/1999
• Est. Priority Date: 10/29/1997
• Status: Expired due to Term

• Current Assignee: SICK Incorporated (Sick)
• Original Assignee: PTO (Safe Fleet Holdings LLC)
• Inventors: Tafoya, Benny R.
• Primary Examiner(s): Le, Thien M.
• Assistant Examiner(s): SHERR, DANIEL H
• Application Number:
  US08/959,680
• Time in Patent Office: 748 Days
• Field of Search: 235/383, 235/462.13, 235/462.24, 235/462.41
• US Class Current: 235/462.24
• CPC Class Codes: G06K 7/10722 Photodetector array or CCD scanning

Abstract

A bar code scanning system for a conveyor system in which a first conveyor and a second conveyor are disposed apart from each other by a small gap region. A light emitting device is positioned in the gap underneath a top surface of the first and second conveyors, and the light emitting device shines light onto bar code labels on a bottom side of objects as the objects traverse from the first conveyor to the second conveyor. A light receiving device is also positioned in the gap, and the light receiving device receives reflected light from the bottom side of the objects due to the light being shined on the objects by the light emitting device. The gap is covered by a glass or plastic plate, so as to allow light to pass substantially therethrough.

Claims

1. A bar code scanning system, comprising:

a first conveyor for moving objects from a first location to a second location;

a second conveyor for receiving the objects from the first conveyor and for moving the objects to a third location;

a light emitting device positioned in a gap underneath a top surface of the first and second conveyors, the light emitting device configured to shine light onto bar code labels on a bottom side of objects as the objects traverse from the first conveyor to the second conveyor;

a light receiving device positioned in the gap, the light receiving device configured to receive reflected light from the bottom side of the objects due to the light being shined on the objects by the light emitting device; and

a window-like unit disposed entirely within the gap, the window-like unit having a top surface disposed along a same plane as the top surfaces of the first and second conveyors,

wherein the top surface of the window-like unit provides a substantially continuous surface with the top surfaces of the first and second conveyors as the objects traverse from the first location to the third location,

wherein the window-like unit provides a magnification to the light output by the light emitting device and the received light directed to the light receiving device.

2. The bar code scanning system according to claim 1, wherein the light receiving device comprises at least one CCD camera having a plurality of pixel elements, each pixel element receiving light from a predetermined region on the top surface of the window-like unit.

3. The bar code scanning system according to claim 2, wherein the window-like unit is comprised of one of glass and plastic.

4. The bar code scanning system according to claim 3, wherein a width of the top surface of the window-like unit is of a size such that the at least one CCD camera, by itself, is not able to directly receive light from all regions of the top surface of the window-like unit, and

wherein the magnification provides compensation such that the at least one CCD camera is able to receive light from all regions of the top surface of the window-like unit.

5. The bar code scanning system according to claim 4, further comprising:

a first light emitting unit and light receiving unit pair disposed to detect a bar code label on a front side of the objects as the objects traverse along the first and second conveyors, the front side being with respect to a direction of movement of the objects;

a second light emitting unit and light receiving unit pair disposed to detect a bar code label on a rear side of the objects as the objects traverse along the first and second conveyors, the rear side being with respect to the direction of movement of the objects;

a third light emitting unit and light receiving unit pair disposed to detect a bar code label on one side of the objects as the objects traverse along the first and second conveyors, the one side being substantially perpendicular with respect to the top surfaces of the first and second conveyors;

a fourth light emitting unit and light receiving unit pair disposed to detect a bar code label on another side of the objects as the objects traverse along the first and second conveyors, the another side being substantially perpendicular with respect to the top surfaces of the first and second conveyors; and

a fifth light emitting unit and light receiving unit pair disposed to detect a bar code label on a top side of the objects as the objects traverse along the first and second conveyors,

wherein the light emitting device and the light receiving device together constitute a sixth light emitting unit and light receiving unit pair.

6. The bar code scanning system according to claim 5, wherein the bar code scanning system is capable of detecting a bar code label disposed anywhere on the objects as the objects traverse from the first location to the third location.

7. The bar code scanning system according to claim 1, wherein one of the first and second conveyors corresponds to a takeaway conveyor, and the other of the first and second conveyors corresponds to a feed conveyor.