Bar code symbol reading system employing electronically-controlled raster-type laser scanner for reading bar code symbols during on hands-on and hands-free modes of operation

• US 7,124,950 B2
• Filed: 04/16/2004
• Issued: 10/24/2006
• Est. Priority Date: 09/16/1997
• Status: Expired due to Fees

• Current Assignee: Metrologic Instruments Incorporated (Honeywell International Inc.)
• Original Assignee: Metrologic Instruments Incorporated (Honeywell International Inc.)
• Inventors: Zhu, Xiaoxun, Knowles, C. Harry, Blake, Robert E., Colavito, Stephen J., Amundsen, Thomas C., Carullo, Thomas, Naylor, Charles
• Primary Examiner(s): Kim, Ahshik
• Application Number:
  US10/826,677
• Publication Number:
  US 20050001036A1
• Time in Patent Office: 921 Days
• Field of Search: 236/462.01, 236/462.09, 23646222-46226, 236/462.44, 236/462.45, 236/472.01, 236/472.03, 236/462.36, 236/462.38
• US Class Current: 235/462.36
• CPC Class Codes: G06K 7/10574 Multiple sources
• 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

Abstract

A bar code symbol reading system is disclosed comprising a hand-supportable bar code symbol reading device which embodies an electronically-controlled bar code symbol reading engine for producing a raster-type laser scanning pattern in either a hands-free or hands-on mode of operation for scanning 1-D and 2D bar code symbols. The electronically-controlled bar code symbol reading engine has (i) a high-speed/high-resolution raster scanning mode of operation, during which a high-speed, high-resolution raster-type scanning pattern is precisely generated under electronic control, and (ii) a high-speed/low-resolution raster scanning mode of operation during which a high-speed, low-resolution raster-type scanning pattern is precisely generated under electronic control. The electronically-controlled bar code symbol reading engine is induced into its high-speed/high-resolution raster scanning mode of operation when the hand-supportable bar code symbol reading device is removed from its support stand, and into its high-speed/low-resolution raster scanning mode when the hand-supportable bar code symbol reading device is placed into its support stand. The bar code symbol reading engine comprises a pair of mechanically-damped off-resonant laser beam scanning mechanisms that are arranged on a miniature optical bench and electronically-controlled by either a synchronously or synchronously driven drive circuit. When asynchronously driven, the raster laser scanning pattern floats slightly along the y-scanning direction to facilitate reading of 2-D bar code symbols during the hands-on mode of operation.

Claims

1. A system capable of producing a raster-type laser scanning pattern for scanning 2-D bar code symbols along x and y axis scanning directions, said system comprising:

a housing;

a light source disposed in said housing, for producing a light beam having cross-sectional characteristics suitable for scanning a 2-D bar code symbol bar code symbol along x and y axis scanning directions;

a first light beam scanning mechanism, disposed in said housing and responsive to a first control signal, for scanning said light beam along said x axis scanning direction using a first scanning element, wherein said first light beam scanning mechanism includes a first electromagnetically driven coil for driving said first scanning element;

a second light beam scanning mechanism, disposed in said housing and responsive to a second control signal, for scanning said light beam along said y axis scanning direction orthogonal to said x axis scanning direction using a second scanning element, wherein said second light beam scanning mechanism includes a second electromagnetically driven coil for driving said second scanning element;

light collecting means disposed in said housing, for collecting light reflected off a bar code symbol scanned by said scanning pattern;

light detecting means disposed in said housing, for detecting said collected light and producing scan data indicative of the intensity of said detected light; and

electronic scanning mechanism control circuitry, disposed in said housing, for electrically controlling the operation of said first and second scanning elements so as to produce a raster-type scanning pattern for scanning said 2-D bar code symbol along x and y axis scanning directions;

wherein said electronic scanning mechanism control circuitry includes (i) a push-pull type drive circuit for producing an x-axis drive voltage signal having periodic characteristics, for driving said first scanning element along said x axis direction, and (ii) an electronically-controlled potentiometer for producing a y-axis drive voltage signal periodically incrementing and decrementing in small quantized voltage level steps, in response to a control signal generated independently from said x-axis drive voltage signal, for driving said second scanning element along said y axis direction.

2. The system of claim 1, wherein said electronic scanning mechanism control circuitry electrically controls said first and second scanning elements in a synchronous manner so that said raster-type scanning pattern as a whole is substantially free of movement relative to said housing.

3. The system of claim 1, wherein said electronic scanning mechanism control circuitry electrically controls said first and second scanning elements in an asynchronous manner so that said raster-type scanning pattern as a whole moves back and forth along relative to said housing so as to improve the scanning of said 2-D bar code symbol when supporting said housing within the hand of an operator.

4. The system of claim 1, wherein said light beam is a laser beam.

5. The system of claim 1, wherein said housing is hand-supportable.

6. The system of claim 1, wherein said housing is body-wearable.

7. The system of claim 1, said scanning pattern is a 1D scanning pattern.

8. The system of claim 1, wherein said electronic scanning mechanism control circuitry comprises means for generating a plurality of y-axis drive voltage signals, each for driving said second scanning element at a different scan rate.

9. The system of claim 1, wherein said scanning element comprises a first scanning element comprises a first mechanically-damped scanning element supported at one end from a first fixed anchoring structure, and driven in an off-resonant manner by said first electromagnetically driven coil;

and wherein second scanning element comprises a second mechanically-damped scanning element supported at one end from a second fixed anchoring structure, and driving in an off-resonant manner said second electromagnetically driven coil.

10. The system of claim 9, wherein said first fixed anchoring structure and said second fixed anchoring structure are provided on a common support platform, in close proximity with each other.

11. The system of claim 10, wherein said common support platform comprises an optical bench.

12. The system of claim 1, wherein said housing is a miniature enclosure that can be supported on the hand of an operator.