METHOD OF PRINTING A BARCODE USING A LINE PRINTHEAD, AND A PRINTING

• US 20110242173A1
• Filed: 03/30/2011
• Published: 10/06/2011
• Est. Priority Date: 03/30/2010
• Status: Active Grant

• Current Assignee: Seiko Epson Corporation (Seiko Group)
• Original Assignee: Seiko Epson Corporation (Seiko Group)
• Inventors: Shimada, Shunichi, Iwasa, Yuya, Zama, Masanori, Omi, Shigeru
• Granted Patent: US 8,662,615 B2
• Time in Patent Office: Days
• US Class Current: 347/13
• CPC Class Codes: B41J 2/2142 Detection of malfunctioning nozzles generating single droplets or particles on demand by pressure, e.g. electromechanical transducers B41J2/045, B41J2/05; jet deflection sensors B41J2/125; for cleaning purposes B41J2/16579
• CPC Class Codes: B41J 2/2146 for line print heads
• CPC Class Codes: B41J 3/01 for special character, e.g. for Chinese characters or barcodes
• CPC Class Codes: G06K 1/121 by printing code marks applying code marks to labels B65C9/46; marking or coding completed packages B65B61/26
• CPC Class Codes: G06K 15/1868 for fitting to an output condition, e.g. paper colour or format
• CPC Class Codes: G06K 15/1889 Merging with other data

Abstract

A barcode printing method can easily and quickly find the location of a group of consecutive printing elements that can print a barcode correctly when the line print head has faulty printing elements. The printing device 1 determines the shift range L5 for the barcode 8 printing position (B11), aligns the center of the barcode 8 print data D2 with the center of the shift range L5, from this position alternately shifts the print data D2 one printing element at a time left and right in the line direction A, and finds a group of consecutive printing elements that can print the barcode 8 correctly (B12). A normal printing range can thus be found in a short time with the smallest shift compared with searching from the end of the shift range, and the overall efficiency of a barcode printing operation that executes repeatedly can be improved.

Claims

1. A method of printing a barcode using a line print head to print a barcode having bars of specific widths arranged in a specific pattern in a direction perpendicular to a recording medium transportation direction, comprising:

a normal/faulty data calculation step that acquires normal/faulty data representing the normal or faulty state of each printing element in the line direction of the printing element array disposed to the line print head;

a determination step that compares the normal/faulty data with the barcode print data, and determines if a faulty printing element is included in the printing element array of the line print head in the barcode printing range in the line direction;

a shiftable range calculation step that calculates a shift range to which the barcode can be shifted in the line direction and printed when a faulty printing element is contained in the printing element array;

a shift destination calculation step that performs a shift operation to find a normal printing range where the barcode can be printed correctly in the line direction of the line print head by alternately executing

an operation that aligns the center of the print data in the line direction with the center of the shift range in the line direction, sequentially shifts the print data one printing element to one side in the line direction, and compares the normal/faulty data and the line print data, and

an operation that sequentially shifts the print data one printing element to the other side in the line direction, and compares the normal/faulty data and the line print data; and

a printing process step that executes a printing process to print the barcode using the printing elements contained in the normal printing range when a normal printing range is found in the shift range.

2. The method of printing a barcode using a line print head described in claim 1, wherein:

the normal/faulty data includes first normal/faulty data representing the position of a first faulty printing element that does not print when driven, and second normal/faulty data representing the position of a second faulty printing element that prints when not driven;

the normal/faulty data calculation step calculates both the first normal/faulty data and the second normal/faulty data;

the determination step makes a first determination that compares the first normal/faulty data and the print data, and determines if the first faulty printing element is contained in the printing element array corresponding to the barcode printing position in the line direction, and

makes a second determination that compares the second normal/faulty data and the print data, and determines if the second faulty printing element is contained in the printing element array corresponding to the barcode printing position in the line direction; and

the shift destination calculation step performs a shift operation to find a normal printing range not containing a first faulty printing element at any print dot formation position of the barcode shifted in the line direction, and not containing a second faulty printing element at any position in the barcode where a print dot is not formed.

3. The method of printing a barcode using a line print head described in claim 1, further comprising:

a fault density calculation step that divides the shift range calculated by the shiftable range calculation step into plural segments, and calculates the density of faulty printing elements in each segment where the density is (number of faulty printing elements/number of printing elements in segment);

wherein the shift destination calculation step performs a shift operation to find a normal printing range for the barcode after aligning the center in the line direction of the line print data with the center in the line direction of the segment with the lowest density.

4. The method of printing a barcode using a line print head described in claim 1, wherein:

the line print head is a line thermal head or a line inkjet head.

5. A printing device comprising:

a line print head having a plurality of printing elements in a row;

a transportation mechanism that conveys a recording medium relative to the line print head in a transportation direction that is perpendicular to the line direction in which the printing elements are arrayed; and

a control circuit that controls driving the line print head and the transportation mechanism, and executes a printing operation to print on the recording medium a barcode composed of a pattern of printed areas and unprinted areas arrayed in a direction perpendicular to the transportation direction,

the control circuit including a normal/faulty data calculation unit that acquires normal/faulty data representing the normal or faulty state of each printing element in the line direction of the printing element array disposed to the line print head;

a determination unit that compares the normal/faulty data with the barcode print data, and determines if a faulty printing element is included in the printing element array of the line print head in the barcode printing range in the line direction;

a shiftable range calculation unit that calculates a shift range to which the barcode can be shifted in the line direction and printed when a faulty printing element is contained in the printing element array;

a shift destination calculation unit that performs a shift operation to find a normal printing range where the barcode can be printed correctly in the line direction of the line print head by alternately executing

an operation that aligns the center of the print data in the line direction with the center of the shift range in the line direction, sequentially shifts the print data one printing element to one side in the line direction, and compares the normal/faulty data and the line print data, and

an operation that sequentially shifts the print data one printing element to the other side in the line direction, and compares the normal/faulty data and the line print data; and

a printing process unit that executes a printing process to print the barcode using the printing elements contained in the normal printing range when a normal printing range is found in the shift range.

6. The printing device described in claim 5, wherein:

the normal/faulty data includes first normal/faulty data representing the position of a first faulty printing element that does not print when driven, and second normal/faulty data representing the position of a second faulty printing element that prints when not driven;

the normal/faulty data calculation unit calculates both the first normal/faulty data and the second normal/faulty data;

the determination unit makes a first determination that compares the first normal/faulty data and the print data, and determines if the first faulty printing element is contained in the printing element array corresponding to the barcode printing position in the line direction, and

makes a second determination that compares the second normal/faulty data and the print data, and determines if the second faulty printing element is contained in the printing element array corresponding to the barcode printing position in the line direction; and

the shift destination calculation unit performs a shift operation to find a normal printing range not containing a first faulty printing element at any print dot formation position of the barcode shifted in the line direction, and not containing a second faulty printing element at any position in the barcode where a print dot is not formed.

7. The printing device described in claim 5, wherein:

the control circuit also includes a fault density calculation unit that divides the shift range calculated by the shiftable range calculation step into plural segments, and calculates the density of faulty printing elements in each segment where the density is (number of faulty printing elements/number of printing elements in segment); and

the shift destination calculation unit performs a shift operation to find a normal printing range for the barcode after aligning the center in the line direction of the line print data with the center in the line direction of the segment with the lowest density.

8. The printing device described in claim 5, wherein:

the line print head is a line thermal head or a line inkjet head.