Scan engine with dual chip architecture for use in electro-optical readers

• US 7,562,826 B2
• Filed: 10/19/2005
• Issued: 07/21/2009
• Est. Priority Date: 09/12/2005
• Status: Active Grant

• Current Assignee: Symbol Technologies, LLC (Zebra Technologies Corporation)
• Original Assignee: Symbol Technologies, Inc. (Zebra Technologies Corporation)
• Inventors: Giebel, James, Sackett, William, Difazio, Costanzo, Schneider, Gary G.
• Primary Examiner(s): LE, THIEN MINH
• Application Number:
  US11/254,092
• Publication Number:
  US 20070057064A1
• Time in Patent Office: 1,371 Days
• Field of Search: 23546201-46445, 23547201-47203, 235/454, 235/455, 235/470
• US Class Current: 235/462.33
• 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 microprocessor and an application specific integrated circuit are embodied as two chips mounted on a printed circuit board which is, in turn, mounted on a scan engine for use in an electro-optical reader. This dual chip architecture is readily configurable and controls reader operation.

Claims

1. A dual chip architecture for controlling electro-optical reading of indicia, comprising:

a) an application specific integrated circuit (ASIC) constituting a first chip on which are integrated a laser drive for energizing a laser to emit a laser beam toward the indicia, a scanner drive for sweeping the laser beam across the indicia for reflection therefrom, a receiver for receiving an analog received signal indicative of the laser beam reflected from the indicia, and a digitizer for digitizing the received signal to generate a digitized signal, at least one of the laser drive, the scanner drive, the receiver and the digitizer having an adjustable element;

b) a microprocessor constituting a second chip operatively connected to the first chip and operative for generating a control signal for adjusting the adjustable element during reading, the microprocessor including a decoder for decoding the digitized signal into data corresponding to the indicia; and

c) a single printed circuit board on which the first and second chips are commonly mounted.

2. The architecture of claim 1, wherein the adjustable element is a digital potentiometer having settings controlled by the microprocessor.

3. The architecture of claim 1, wherein the at least one of the laser drive, the scanner drive, the receiver and the digitizer generates a feedback signal during reading of the indicia, and wherein the microprocessor receives and processes the feedback signal to generate the control signal.

4. The architecture of claim 1, wherein the chips are operatively connected over a serial interface, and wherein the microprocessor is operatively connected to a host over another serial interface.

5. The architecture of claim 1, and a temperature sensor integrated on the ASIC for measuring temperature and for sending a measured temperature to the microprocessor.

6. The architecture of claim 1, wherein the microprocessor has a memory in which reading parameters are stored and recalled during reading of the indicia.

7. A scan engine in a reader for electro-optically reading indicia, comprising:

a) an energizable laser for emitting a laser beam toward the indicia;

b) an actuatable scanner for sweeping the laser beam across the indicia for reflection therefrom;

c) a detector for detecting light reflected from the indicia to generate an analog received signal;

d) an application specific integrated circuit (ASIC) constituting a first chip on which are integrated a laser drive for energizing the laser, a scanner drive for actuating the scanner, a receiver for receiving the received signal, and a digitizer for digitizing the received signal to generate a digitized signal, at least one of the laser drive, the scanner drive, the receiver and the digitizer having an adjustable element;

e) a microprocessor constituting a second chip operatively connected to the first chip and operative for generating a control signal for adjusting the adjustable element during reading, the microprocessor including a decoder for decoding the digitized signal into data corresponding to the indicia; and

f) a single printed circuit board on which the first and second chips are commonly mounted.

8. The scan engine of claim 7, wherein the adjustable element is a digital potentiometer having settings controlled by the microprocessor.

9. The scan engine of claim 7, wherein the at least one of the laser drive, the scanner drive, the receiver and the digitizer generates a feedback signal during reading of the indicia, and wherein the microprocessor receives and processes the feedback signal to generate the control signal.

10. The scan engine of claim 7, wherein the chips are operatively connected over a serial interface, and wherein the microprocessor is operatively connected to a host over another serial interface.

11. The scan engine of claim 7, and a temperature sensor integrated on the ASIC for measuring temperature and for sending a measured temperature to the microprocessor.

12. The scan engine of claim 7, wherein the microprocessor has a memory in which reading parameters are stored and recalled during reading of the indicia.

13. A method of controlling electro-optical reading of indicia, comprising the steps of:

a) integrating, on an application specific integrated circuit (ASIC), a laser drive for energizing a laser to emit a laser beam toward the indicia, a scanner drive for sweeping the laser beam across the indicia for reflection therefrom, a receiver for receiving an analog received signal indicative of the laser beam reflected from the indicia, and a digitizer for digitizing the received signal to generate a digitized signal, and integrating at least one adjustable element on the ASIC;

b) decoding the digitized signal into data corresponding to the indicia by a microprocessor operatively connected to the ASIC, and adjusting operation of the ASIC by the microprocessor by generating a control signal by the microprocessor to adjust the at least one adjustable element during reading; and

c) commonly mounting the ASIC constituting a first chip and the microprocessor constituting a second chip on a single printed circuit board.

14. The method of claim 13, and the step of measuring temperature by integrating a temperature sensor on the ASIC.

15. An arrangement for controlling output power of a laser having a laser diode for emitting a laser beam during electro-optical reading of indicia and a monitor photodiode for generating a negative feedback signal proportional to the output power of the laser beam, the arrangement comprising:

a) an application specific integrated circuit (ASIC) on which a laser drive is integrated, the laser drive including a feedback circuit for regulating the output power of the laser beam as a function of the negative feedback signal, and an adjustable element having power settings; and

b) a microprocessor operatively connected to the ASIC for generating a control signal for setting the adjustable element to one of the power settings during reading.

16. The arrangement of claim 15, wherein the adjustable element is a digital potentiometer.