JP2011183763A - Printing method for printer, and printer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a printer capable of achieving frame-less printing and printing with set margin even if skew occurs, and maintaining the effect of a correction added to the original print data, and to provide a printing method therefor. <P>SOLUTION: Based on the detection result of a sensor unit 9, the control section 10 of the printer 1 calculates a protrusion direction D and protrusion width E of recording paper 3 at a printing position A from a reference passage area C. Then, each printing dot line 11 of print data created on condition that the recording paper 3 passes through the reference passage area is printed by cutting an end opposite to the protrusion direction D by an amount corresponding to a length identical to the protrusion width E. Besides, printing is performed by adding a dot line 13 of a length identical to the protrusion width E to the end of each printing dot line 11 in the protrusion direction D. The dot line 13 is obtained by copying a printing dot 14 located at the endmost position of the original printing dot line 11 in the protrusion direction D. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a printer that can suppress printing defects caused by a state in which a recording medium is conveyed obliquely (so-called skew) and a printing method therefor.

  In a printer in which the conveyance accuracy of the recording medium is poor and skew occurs, there is a problem that when the skew occurs, the print data cannot be printed with the expected layout. For example, when borderless printing is performed using print data that is printed in an area having the same width as the width of the recording medium, a margin of a shape corresponding to the skew amount remains outside the printed area. The target borderless printing cannot be performed. In printing of print data in which a margin is provided outside the print area, if a skew occurs, the margin width is different from the set width. Also, the margin width cannot be made constant.

  In addition, there is a problem that the print area protrudes from the recording medium due to the skew. In this case, since printing is performed at a position off the recording medium, in the case of label paper, problems such as contamination of the mount portion removed from the label or contamination of the platen with ink occur. As a method for preventing such a printing area from protruding, it is assumed that the printing area protrudes due to skew in advance, and the size of the printing area is made smaller than that of the recording medium so that a margin corresponding to this dimension can be secured. Setting is done.

  Japanese Patent Application Laid-Open No. 2004-228561 detects the amount of displacement and the direction of displacement of a recording medium due to skew, and determines the print position of each digit (each pixel) in print data according to the detected amount of displacement and the direction of displacement. A printer for shifting is disclosed. According to this method, it is possible to perform borderless printing or printing with a margin width as set even if skew occurs. In addition, since it is not necessary to secure a margin according to an assumed skew amount in order to prevent a lack of print contents, the print area can be enlarged.

JP2007-230071A

  Here, in a recording head provided with a printing dot forming means such as a large number of nozzles and heating elements, due to manufacturing errors or mounting errors of the recording head, between printing dots when formed using different nozzles or heating elements. Density unevenness occurs. Therefore, in order to eliminate such density unevenness, the printing quality is improved by correcting the ink discharge amount for each nozzle or by correcting the heating amount for each heating element.

  When such correction is performed, when the process of shifting the printing position of each pixel is performed as in Patent Document 1, the nozzles and heating elements used to print each pixel are shifted by the shift process. Deviation from the original setting. Therefore, if the print data before the shift is data that has been corrected to print each pixel at the target density, the intended effect cannot be obtained by the correction, so the print quality can be improved. There is a problem that can not be.

  In view of this point, the problem of the present invention is that it is possible to reduce the influence of skew on the printing result, and even when skew occurs, it is possible to realize borderless printing or printing with a margin width as set, and to improve printing quality. Therefore, it is an object of the present invention to propose a printer and a printing method capable of maintaining the correction effect added to the original print data as it is.

  Another object of the present invention is to propose a printer and a printing method therefor that can reliably prevent printing from protruding from a recording medium due to skew.

In order to solve the above-described problems, the present invention provides a printer that performs printing on a portion of the recording medium that passes through the printing position while conveying the recording medium along a conveyance path that passes through the printing position by the print head. Printing method,
Set a reference passage area in the width direction of the recording medium at the printing position,
Detecting a passing position of the recording medium in the width direction in the conveyance path while conveying the recording medium along the conveyance path;
Based on the detected passing position, a protruding direction and a protruding width of the portion of the recording medium at the printing position from the reference passing area are determined,
A print pixel row to the portion of the recording medium at the print position is extracted from print data on the assumption that the recording medium is in the reference passage region at the print position, and the protruding direction in the print pixel row is A pixel row having a length corresponding to the protrusion width is added to the end portion on the side, and printing is performed.

  As described above, the present invention does not change the print position of the original print pixel array included in the print data. For this reason, the effect such as density correction performed on the print data can be maintained as it is. In addition, the print pixel row can be extended to a portion that protrudes from the reference passage area due to skew or the like, that is, a portion that has conventionally become a blank space. In this way, even if skew occurs, it is possible to prevent the edge line of the print area from being inclined with respect to the edge line of the recording medium, so that the influence of the skew on the print result can be reduced. In particular, if the length of the pixel row to be added is set appropriately, borderless printing and a margin width as set can be reliably realized.

  At this time, one pixel located at the extreme end on the protruding direction side in the printing pixel column is extracted, and a pixel column in which the same pixels as the one pixel are arranged in a length corresponding to the protruding width is used as the printing pixel. It is desirable to add to the end of the row on the protruding direction side. In this way, the added pixel row is connected to the original print pixel row without a sense of incongruity, and it becomes difficult to distinguish the added pixel row from the original print pixel row. Therefore, the print result does not become unnatural. Also, it becomes difficult for the user to notice that the pixel has been added.

  Further, by adding a pixel column having the same length as the protruding width to an end portion on the protruding direction side in the printing pixel column, it is possible to surely realize marginless printing or a margin width as set.

  In the present invention, it is desirable to print by deleting a portion of the print pixel row opposite to the protruding direction by a length corresponding to the protruding width. In this way, it is possible to reliably prevent the deleted portion from being printed at a position off the recording medium, and to prevent the printing from protruding from the recording medium due to skew. In particular, when printing is performed by deleting the portion of the print pixel row opposite to the protruding direction by the same length as the protruding width, printing protruding from the recording medium due to skew is completely eliminated. Can be prevented. Therefore, it is possible to prevent the printing from protruding to a position off the label when the label sheet is a recording sheet, and to prevent the mount portion and the platen from being stained.

Next, the printer of the present invention is
Conveying means for conveying the recording medium along a conveying path passing through the printing position;
A print head for printing on a portion of the recording medium that passes through the printing position;
Detecting means for detecting a passing position of the recording medium in the width direction in the conveyance path;
And a control unit that performs printing on the recording medium according to the printing method of the printer.

  In the printer according to the aspect of the invention, the print head may be of a line type, and the detection unit may detect a width direction end of the recording medium. In this way, if a line-type print head that transfers print data while shifting it with a shift register is used, the beginning or end of the print data may be copied and added, or blanks may be added to prevent printing. Easy to do. Further, the skew can be easily detected by detecting the edge of the recording paper.

  According to the present invention, it is possible to maintain the effect such as density correction performed on the original print data as it is. In addition, since the print pixel row can be extended to a portion that protrudes from the reference passage area due to skew or the like, that is, a portion that has conventionally become a blank space, the influence of the skew on the printing result can be reduced. In particular, if the length of the pixel row to be added is set appropriately, borderless printing and a margin width as set can be reliably realized.

1 is a schematic configuration diagram of a main part of a printer to which the present invention is applied. It is explanatory drawing of the printing dot row formed on a recording paper. FIG. 6 is an explanatory diagram illustrating a state when a skew of recording paper occurs. 3 is a flowchart of a printing method to which the present invention is applied. It is explanatory drawing of the printing dot row printed when a skew generate | occur | produces.

  Hereinafter, embodiments of a printer to which the present invention is applied and a printing method thereof will be described with reference to the drawings.

(Overall printer configuration)
FIG. 1 is a schematic configuration diagram of the main part of the printer. FIG. 1A is a side configuration, FIG. 1B is a plan configuration, and FIG. 1C is a block diagram of a printer control system. The printer 1 is an ink jet printer, and includes a recording paper transport mechanism 4 (transport means) that transports a long recording paper 3 along a transport path 2 provided inside the printer 1. A platen 5 is disposed along the conveyance path 2, and a printing position A on the conveyance path 2 is defined by the platen 5. A carriage guide shaft 6 is bridged in a direction crossing the transport path 2, and a carriage 7 that reciprocates along the carriage guide shaft 6 is provided. An ink jet head 8 is mounted on the carriage 7. The inkjet head 8 is disposed with the ink nozzle surface facing the platen 5 side.

  A detection position B for detecting a passing position in the width direction of the recording paper 3 is set on the upstream side in the conveyance direction of the printing position A in the conveyance path 2, and a sensor unit 9 (detection means) is set at the detection position B. Is provided. In this embodiment, as the sensor unit 9, an LED light source that irradiates the recording paper 3 on the conveyance path 2 with inspection light, a CCD element for detecting reflected light from the recording paper 3, and the reflected light as a CCD element. A CIS (contact image sensor) provided with a lens array or the like for forming an image is used. Since the sensor unit 9 is configured by arranging LED light sources and CCD elements in a direction crossing the conveyance path 2, the positions of the left end and the right end of the recording paper 3 can be detected based on the amount of light received by each CCD element. .

  FIG. 2 is an explanatory diagram of print dot rows formed on the recording paper. When receiving the print data, the control unit 10 of the printer 1 controls the carriage driving mechanism 7a in conjunction with this conveyance operation while controlling the recording sheet conveyance mechanism 4 to convey the recording sheet 3, and reciprocates the carriage 7. Move. Then, ink is ejected from each nozzle of the inkjet head 8 while scanning the inkjet head 8 mounted on the carriage 7 in the printing position A in the direction crossing the transport path 2. With these operations, every time the recording paper 3 is conveyed by a predetermined pitch, the print dot row 11 (lined in the scanning direction of the carriage 7) is arranged on the print target portion 3a that is the portion of the recording paper 3 that has reached the printing position A. Print pixel column) is formed.

  In FIG. 2, as an example of the recording paper 3, a label paper in which a fixed label is attached to a long mount made of release paper is illustrated. In the case of label paper, print data is created so that each print dot row 11 is formed in the area of the label 3b.

  FIG. 3 is an explanatory diagram showing a state when the skew (skew) of the recording paper occurs. The recording paper transport mechanism 4 is configured to transport each portion of the recording paper 3 while maintaining a state in which each portion of the recording paper 3 is aligned with a preset transport reference position, for example, the center position or the left end position of the transport path 2. . However, the recording paper 3 is tilted with respect to the transport path 2 when the recording paper 3 is set to be tilted with respect to the transport path 2 or when the paper feeding is not performed evenly for some reason. 3, the recording paper 3 may be displaced in the width direction from the conveyance reference position at the printing position A as shown in FIG. 3.

  FIG. 3 shows a passing area (reference passing area C) of the recording paper 3 in a state where the position is not displaced from the conveyance reference position. When the skew of the recording paper 3 occurs, each portion of the recording paper 3 is displaced in the width direction with respect to the reference passage area C by a dimension corresponding to the skew amount. In the present embodiment, the actual passing position of the recording paper 3 is detected by the sensor unit 9 at the detection position B immediately before reaching the printing position A. Based on the detection result, the protruding direction D and the protruding width E of the actual passing position of the recording paper 3 at the printing position A from the reference passing area C are calculated. For example, when the printing position A and the detection position B are sufficiently close as in the present embodiment, the misalignment direction at the detection position B matches the protruding direction D of the recording paper 3 at the printing position A. Further, the misalignment amount at the detection position B and the protrusion width E of the recording paper 3 at the printing position A can be handled as the same.

  The reference passage area C can be set in advance according to the type of the recording paper 3 to be used and the alignment reference. Alternatively, the reference passage area C may be specified in the print data. As described above, when label paper is used as the recording paper 3, the end position of the recording paper 3 detected by the sensor unit 9 may be the end position of the mount portion or the end position of the label portion. When the end position of the mount portion is detected, the pass area of the mount portion can be set as the reference pass area C as shown in FIG. Further, when detecting the end position of the label portion, the passage region of the label portion may be set as the reference passage region C.

(Printing method when skew occurs)
In the present embodiment, if the actual passing position of the recording paper 3 is deviated from the reference passing area C based on the detection result of the sensor unit 9, it is determined. Then, based on the detected protruding direction D and protruding width E, the end portion on the protruding direction D side of the print dot row 11 to be printed on the portion of the recording paper 3 that reaches the printing position A (print target portion 3a). Is extended by the length corresponding to the protruding width E, and the end on the side opposite to the protruding direction D is processed so as not to be printed by the length corresponding to the protruding width E, and the printing operation is performed. .

  FIG. 4 is a flowchart of a printing method to which the present invention is applied. The control unit 10 of the printer 1 performs steps S1 to S4 each time the recording paper 3 is conveyed by a predetermined amount. First, in step S1, the sensor unit 9 detects the actual passing position of the recording paper 3. Subsequently, in step S2, the protrusion direction D and the protrusion width E of the recording paper 3 from the reference passage region C at the printing position A are calculated based on the detection result of step S1 and the preset reference passage region C. Then, it is determined whether or not there is a skew. Specifically, in step S2, it is determined whether or not the protrusion width E is greater than or equal to a predetermined threshold value. The threshold value can be set as appropriate. For example, the width can be set to 1 dot, or can be set according to the resolution of the print data.

  When it is determined that the protrusion width E is equal to or greater than the threshold (step S2: Yes), the control unit 10 determines that a skew has occurred and proceeds to step S3. On the other hand, if it is determined that the protrusion width E is less than the threshold (step S2: No), it is determined that no skew has occurred, and the process proceeds to step S4. In step S4, the control unit 10 expands the print data generated on the assumption that the recording paper 3 is in the reference passage area C as it is, and moves the print dot row 11 to the position indicated in the print data. Form with the contents as instructed.

  FIG. 5A is an explanatory diagram of a print dot row to be printed when a skew occurs. When the process proceeds to step S3, the control unit 10 uses the print data generated on the assumption that the recording paper 3 is in the reference passage area C, and the print dot row 11 printed on the print target portion 3a. A part of the data is printed at a position as instructed by the print data. Specifically, the printing dots at the end opposite to the protruding direction D in the print dot row 11 are deleted by the same length as the protruding width E, and the remaining portion is printed according to the print data. Reference numeral 12 in FIG. 5A denotes a dot row of a deleted portion that has not been printed. Then, a dot row having the same length as the protruding width E is added to the end portion on the protruding direction D side in the print dot row 11 for printing. Reference numeral 13 in FIG. 5A denotes an added dot row.

  In the print dot row 11A formed by the printing method as described above, the end of the original print dot row 11 on the protruding direction D side is extended by the same length as the protruding width E, and is opposite to the protruding direction D. The end on the side is cut by the same length as the protruding width E. For this reason, the print dot row 11A is printed on the recording paper 3 in the layout as instructed in the print data even though the recording paper 3 is displaced in the width direction from the reference passage region C due to the skew. . Therefore, even if the skew occurs, the printing data for borderless printing is used in the section from one end to the other end of the recording paper 3 (in the example of FIG. 5A, from one end to the other end of the label 3b). Arranged printing dot rows can be formed. Thereby, borderless printing can be reliably performed. In addition, even for data with a margin, a margin width as specified in the print data can be realized.

  Here, FIG. 5A shows only one print dot row 11, but the inkjet head 8 has a nozzle row in which a plurality of nozzles are arranged at a predetermined nozzle pitch in the conveyance direction of the recording paper 3. Is provided. Therefore, a plurality of print dot rows 11 can be formed each time the recording paper 3 is conveyed by a predetermined pitch. When a plurality of print dot rows 11 are formed, the dot row 13 and the dot row 12 are deleted for each print dot row 11 as described above.

  FIG. 5B is an enlarged view of a portion where the dot row 13 is added to the print dot row 11A. The added dot row 13 is obtained by arranging print dots having the same contents as the print dots 14 positioned at the extreme end on the protruding direction D side in the original printed dot row 11 and having the same length as the protruding width E. For this reason, the added dot row 13 is connected to the end of the original print dot row 11 without a sense of incongruity, and it is difficult to recognize the boundary with the original print dot row 11. Therefore, the print result does not become unnatural, and it is difficult for the user to notice that the print data has been processed.

  As described above, according to the printing method of the present embodiment, in the print dot row extracted from the original print data, all portions that are printed without being cut are printed at the positions as instructed. That is, all the dots of the portion printed without being cut are printed using the nozzles as instructed by the original print data. Therefore, in the original print data, when correction is made to the ink ejection amount from each nozzle in order to eliminate density unevenness between print dots, the effect of this correction can be obtained as intended. . Therefore. It is possible to suppress defects in printing results due to skew without impairing the print quality improvement effect due to correction.

  Further, in the printing method of the present embodiment, data for printing dots at positions overlapping the skewed recording paper 3 among the original print data is used as it is, and the length corresponding to the protrusion width E is used. Since only the additional dot row 13 needs to be newly generated, the increase in the data amount is small. For example, there is an advantage that an increase in the amount of data can be reduced as compared with a method of expanding the print area of the original print data to a dimension including all the skewed labels 3b.

(Modification example)
(1) The printer and the printing method of the above embodiment are those in which the present invention is applied to an ink jet printer. However, the present invention can be applied in the width direction of the recording paper 3 at the printing position A while transporting the recording paper 3. The present invention can be applied to various line printers that sequentially form extending print lines. That is, in this type of line printer, the end of the recording paper 3 in each printing line on the protruding direction D side is extended by a dimension corresponding to the protruding width E, and the end of each printing line opposite to the protruding direction D is extended. It is only necessary to cut the portion by a dimension corresponding to the protruding width E and perform printing. For example, in the case of the line-type inkjet head 8, print data is transferred while being shifted by a shift register prepared for the number of nozzles. Therefore, at this time, it is possible to easily perform a process of copying and adding the beginning or end of the print data or adding a blank so as not to print.

(2) In the above embodiment, the CIS is used as the sensor unit 9 for detecting the passing position of the recording paper 3. However, a CCD image sensor having a reduction optical system using a mirror may be used. . It is also possible to arrange a plurality of photosensors at a predetermined pitch in the width direction of the recording paper 3 and detect the end position of the recording paper 3 based on the detection result of each photosensor.

(3) In the above embodiment, the left end and the right end of the recording paper 3 are detected at the transport position immediately before the printing position A, and the amount of misalignment and the direction of misalignment of the recording paper 3 due to the skew (the protruding direction D and the protruding width). E) is calculated, but the amount of skew may be detected by another detection position and detection method, and the protrusion direction D and the protrusion width E may be calculated. For example, a mark for position detection and tilt detection is printed on the back surface of the recording paper 3, and the tilt angle of the recording paper 3 at the detection position and the positional deviation amount in the width direction are calculated based on the read result of the mark. . Then, based on the calculation result, the protruding direction D and the protruding width E at the printing position A may be calculated. When the recording paper 3 is a label paper, two photosensors arranged in the width direction of the transport path 2 are provided at the detection position, and the difference between the passing timings of the left end portion and the right end portion of the leading end of each label is determined. Based on this, the inclination angle of each label with respect to the transport direction can be detected.

(4) In the above embodiment, a dot row having the same length as the protruding width E is added and deleted. However, considering the detection error of the passing position of the recording paper 3 by the sensor unit 9, etc. Longer dot rows or shorter dot rows may be added or deleted.

(5) In the above embodiment, the dot row 13 to be added is composed of dots copied from the end print dot 14 of the original print dot row 11, but the dot row 13 to be added is counted from the end. A dot row in which a predetermined number of printing dots are repeatedly arranged may be used. For example, when the resolution of the original image of the print data is larger than the dot pitch, the number of dots corresponding to the resolution of the original image may be repeatedly arranged.

DESCRIPTION OF SYMBOLS 1 ... Printer, 2 ... Conveyance path, 3 ... Recording paper (recording medium), 3a ... Print target part, 3b ... Label, 4 ... Recording paper conveyance mechanism (conveyance means), 5 ... Platen, 6 ... Carriage guide shaft, 7 DESCRIPTION OF SYMBOLS ... Carriage, 7a ... Carriage drive mechanism, 8 ... Inkjet head (print head), 9 ... Sensor unit (detection means), 10 ... Control part, 11 ... Print dot row (print pixel row), 11A ... Print dot row, 12 ... dot row, 13 ... dot row, 14 ... print dot (pixel), A ... print position, B ... detection position, C ... reference passage area, D ... extruding direction, E ... extruding width

Claims (7)

A printing method for a printer that performs printing on a portion of the recording medium that passes through the printing position while conveying the recording medium along a conveyance path that passes through a printing position by a print head,
Set a reference passage area in the width direction of the recording medium at the printing position,
Detecting a passing position of the recording medium in the width direction in the conveyance path while conveying the recording medium along the conveyance path;
Based on the detected passing position, a protruding direction and a protruding width of the portion of the recording medium at the printing position from the reference passing area are determined,
A print pixel row to the portion of the recording medium at the print position is extracted from print data on the assumption that the recording medium is in the reference passage region at the print position, and the protruding direction in the print pixel row is A printing method for a printer, wherein a pixel row having a length corresponding to the protruding width is added to an end portion on the side for printing. In claim 1,
Extracting one pixel located at the extreme end on the protruding direction side in the print pixel row;
A printing method for a printer, wherein a pixel column in which pixels identical to the one pixel are arranged in a length corresponding to the protruding width is added to an end of the printing pixel column on the protruding direction side. In claim 1 or 2,
A printing method for a printer, wherein a pixel row having the same length as the protruding width is added to an end of the printing pixel row on the protruding direction side. In any one of claims 1 to 3,
A printing method for a printer, wherein printing is performed by deleting a portion of the print pixel row opposite to the protruding direction by a length corresponding to the protruding width. In any one of claims 1 to 3,
A printing method for a printer, wherein printing is performed by deleting a portion of the print pixel array opposite to the protruding direction by the same length as the protruding width. Conveying means for conveying the recording medium along a conveying path passing through the printing position;
A print head for printing on a portion of the recording medium that passes through the printing position;
Detecting means for detecting a passing position of the recording medium in the width direction in the conveyance path;
A printer comprising: a control unit that performs printing on the recording medium by the printer printing method according to claim 1. In claim 6,
The print head is of a line type,
The printer according to claim 1, wherein the detection unit detects an end in the width direction of the recording medium.

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