JP2008221645A - Print control unit, print control method, and medium with recorded print control program - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To establish compatibility between the correction of kicking and that of unevenness in the property of each nozzle. <P>SOLUTION: This print control unit determines the amount of alignment so that the correction of kicking can be generated in the center of a certain path, in step S100, on the basis of at least the type of a printing medium and a printing condition for specifying borderless printing or printing with a border, hastens upper-end processing by the amount of the alignment in step S110, so as to make a position of the correction of the kicking certainly set in the center of a path during printing processing by a normal feeding section in step S120, and delays a printing start raster in the upper-end processing by the amount of the alignment, so as to apply a correction value of density correction to the upper-end processing in step S110, the printing processing by the normal feeding section in step S120, and lower-end processing in step S130, which are continuously performed, without misalignment. Thus, the print control unit can achieve high-precision printing by establishing the compatibility between the correction of the kicking and that of the unevenness in the property of each nozzle. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a print control apparatus, a print control method, and a medium on which a print control program is recorded.

In an ink jet printer, since the color ink discharge direction is slightly different for each nozzle, a phenomenon called banding may occur. As a conventional print control apparatus for solving this problem, the one shown in Patent Document 1 is known. In the publication, a test pattern is read by a CCD sensor, and characteristic unevenness for each nozzle is corrected by a weighting coefficient for error diffusion.
Japanese Patent Laid-Open No. 2-54676

  The printing apparatus conveys a print medium (printing paper) by a pair of conveyance rollers on the upstream side and the downstream side of the print head. However, when the printing medium is conveyed downstream with printing, it passes through the upstream conveying roller at a certain point and is sandwiched only by the downstream conveying roller. At this moment (the moment of kicking), a phenomenon occurs in which the print medium conveyance amount deviates from the target value.

  On the other hand, the symptom can be improved by preparing a correction value corresponding to each printing condition such as the type of printing medium and applying a target transport amount reflecting the correction value (hereinafter simply referred to as “kicking correction”). I understood. Moreover, in applying this, the phenomenon can be most avoided if it is caused to occur in the middle of the conveyance where there is a moment of kicking.

  When the interval between the nozzles (nozzle pitch) formed on the print head of the printing apparatus is different from the raster interval (raster pitch) during printing, in order to improve the quality efficiently, Print on the downstream side) by fine conveyance corresponding to the raster pitch (referred to as upper end processing), and then perform printing by conveyance that is one raster pitch greater than the nozzle pitch (usually called the feed section), and print media Printing (referred to as lower end processing) is performed again at the rear end portion (uppermost stream side) of the conveyance corresponding to the raster pitch.

  The moment of kicking is uniquely determined by the printing conditions such as the length of the print medium, so it can be realized by adjusting the start position of the top edge process to occur in the middle of one transport. . At this time, the print start position must be a position delayed from the original raster position so as not to shift due to the relationship with the print medium. In addition, since conveyance can be performed only in a certain direction, adjustment is impossible other than advancing the start position of the upper end process.

  However, in the conventional method for correcting the characteristic unevenness for each nozzle described above, each raster and the correction method correspond closely. For this reason, there is a problem that it cannot be applied when it is necessary to change each raster position by changing the start position of the upper end process.

  An object of the present invention is to provide a print control apparatus, a print control method, and a medium on which a print control program can be recorded, which can achieve both kick correction and correction of characteristic unevenness for each nozzle.

In order to achieve the above object, the main invention is:
A plurality of printers that transport a predetermined print medium in the sub-scanning direction and record on the print medium using the print head, corresponding to a plurality of target transport positions relative to the print head of the print medium. A first conveyance correction unit that holds the correction value of the feed amount and causes the printer to perform the corrected conveyance in correspondence with the target conveyance position;
A density correction unit that performs density correction for each predetermined raster based on density deviation data measured in advance in each of the upper end process, the normal feeding unit, and the lower end process during printing by the printer;
A printing control apparatus comprising: a second conveyance correction unit configured to perform conveyance corrected by the printer based on data of a feeding error caused by a relative positional relationship between a conveyance mechanism in the printer and an end portion of the print medium. And
Based on the applied printing conditions, the upper end of the upper end process is controlled while increasing the timing at which the upper end process is started so that the correction applied by the second transport correcting unit is applied at the transport timing specified in advance. A positioning amount applying unit that controls to lower the raster for which printing is started at the time of processing, and shifts the raster to which the subsequent density correction is applied to the density correcting unit by the amount of the lowered raster. It is set as the structure which comprises.

  It should be noted that the present invention is not necessarily limited to a substantial apparatus, and it can be easily understood that the present invention functions as a method.

  Further, the present invention is not limited to this, and may include various aspects, such as a case where the print control apparatus exists alone or may be used in a state where it is incorporated in a certain device. Therefore, it can be changed as appropriate, such as software or hardware.

  In the case of software as an embodiment of the idea of the invention, it naturally exists on a recording medium on which such software is recorded, and it must be used. Of course, the recording medium may be a magnetic recording medium, a magneto-optical recording medium, or any recording medium that will be developed in the future. In addition, the duplication stages such as the primary duplication product and the secondary duplication product are equivalent without any question. In addition, even when the communication method is used as a supply method, the present invention is not changed.

  Further, even when a part is software and a part is realized by hardware, the idea of the invention is not completely different, and a part is stored on a recording medium and is appropriately changed as necessary. It may be in the form of being read.

  When the present invention is realized by software, a configuration using hardware or an operating system may be used, or may be realized separately from these. For example, even if it is a variety of arithmetic processing, if it can be processed by calling a predetermined function in the operating system, it can also be input from hardware without calling such a function. is there. It can be understood that the present invention can be implemented only by this program in the process in which the program is recorded on the medium and distributed even though it is actually realized under the intervention of the operating system.

  When the present invention is implemented by software, the present invention is not only realized as a medium storing a program, but the present invention is naturally realized as a program itself, and the program itself is also included in the present invention.

  Other features of the present invention will become apparent from the description of the present specification and the accompanying drawings.

  At least the following matters will become clear from the description of the present specification and the accompanying drawings.

  According to the configuration of the main invention described above, the first transport correction unit transports a predetermined print medium in the sub-scanning direction and uses the print head to record on the print medium. A plurality of feed amount correction values corresponding to a plurality of target transport positions relative to the print head are held, and the printer performs transport corrected in correspondence with the target transport position. In addition, the density correction unit causes the density correction to be performed for each predetermined raster based on the density deviation data measured in advance in each of the upper end process, the normal feeding unit, and the lower end process when printing by the printer. Further, the second transport correction means causes the transport corrected by the printer to be performed based on the data of the feed error caused by the relative positional relationship between the transport mechanism in the printer and the end portion of the print medium.

  Here, the alignment amount application unit starts the upper end process so that the correction applied by the second conveyance correction unit is applied at the conveyance timing specified in advance based on the applied printing condition. While controlling the timing to be advanced, the control is performed to lower the raster from which printing is started in the same upper end processing, and the subsequent density correction is applied to the density correction means by the amount of the raster that has been decreased. Shift the raster.

  In controlling the printer, the halftone module inputs multi-tone image data in a color space different from that of the printer and performs color conversion to multi-tone image data in the printer color space. The converted image data is converted into low gradation print data that can be recorded by the printer, the interlace module inputs the low gradation print data, and the print head performs the main scan and full scan. Raster density data is generated when recording is performed, and the density correction unit causes the density correction corresponding to the raster position to be performed on the image data color-converted by the halftone module into the color space of the printer. The density correction is performed by lowering the raster position by the amount of raster applied by the alignment amount applying means. As a result, the registration amount application unit substantially shifts the raster to which the density correction is applied thereafter by the amount of the lowered raster with respect to the density correction unit.

  An example of the phenomenon that the second transport correction unit corrects corresponds to a shift in the transport amount that occurs when the transport roller of the transport mechanism in the printer changes from a state in which the print medium is sandwiched to a state in which the print medium is not sandwiched. . On the premise of such a phenomenon, the alignment amount applying means is configured such that the timing at which the conveyance roller changes from the state in which the printing medium is nipped to the state in which the printing medium is not nipped is approximately at the center of one conveyance in the normal feeding unit. It is possible to control to raise the timing at which the upper end processing is started so as to occur, and to lower the raster at which printing is started at the time of the upper end processing.

  As described above, when the registration amount application unit lowers the raster from which printing is started in the upper end process, the relationship between the subsequent transport timing and the raster is shifted, and the transport roller pinches the print medium. It is possible to cause the timing to change from the state to the state in which it is not sandwiched to occur at the approximate center of one transport in the normal feeding unit.

  There are various printing conditions for calculating the timing in advance, but at least the registration amount application means includes information on whether printing is bordered or borderless printing and the type of printing medium as the printing condition. It is possible to realize the configuration.

  Relative or borderless printing determines the relative position at which top edge processing begins for the print medium, and the type of print medium corresponds to the length of the print medium, from the trailing edge of the print medium. The above timing is reached at a predetermined distance. Therefore, when the alignment amount application unit acquires these pieces of information, the timing can be generated at a predetermined time.

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. (1) Schematic configuration (2) First transport correction means (3) Density correction means (4) Second transport correction means (5) Problems of density correction means Point (6) The description will be made in the order of the flow of the printing process.

(1) Schematic Configuration of Printing System FIG. 1 is a block diagram showing a printing system to which a printing control apparatus according to an embodiment of the present invention is applied.

  In the figure, the computer 10 corresponds to a personal computer or the like. In addition to CPU, ROM, and RAM as hardware, it includes an external storage device such as a hard disk (not shown), an optical storage medium reader, etc., a keyboard, a mouse, etc. as input devices, and a display, etc. .

  The computer 10 realizes a predetermined function by organically linking software and hardware. In the present embodiment, a printer driver 20, an application 30, correction data creation software 40 and the like as shown in the figure are provided as software configurations.

  The application 30 outputs to the printer driver 20 dot-matrix image data composed of 256 gradation data for each RGB color per pixel as a print target. The color space mainly used by the computer 10 is the RGB color space. However, since the printer 50 adopts the CMY color space, the printer driver 20 converts the image data in the RGB color space into print data in the CMY color space. The color is converted and output to the printer 50. Further, the computer 10 handles multi-gradation image data of 256 gradations, but the printer 50 only records whether or not to add colored ink as dots of a certain size or whether or not to add dots of several sizes. Can not. For this reason, the printer driver 20 performs gradation conversion from multi-gradation to low gradation and outputs it to the printer 50. Such color conversion and gradation conversion are performed by the halftone module 21 in the printer driver 20.

  The interlace module 22 outputs a print command including the print data to the printer 50 based on the print data generated by the halftone module 21. Here, a schematic configuration of the printer 50 will be described.

  The printer 50 includes a CPU, a ROM, and a RAM, and mainly controls the control unit 51, a head unit 52 that discharges color ink, and main scanning that makes the head unit 52 perpendicular to the flow direction of the print medium. A carriage unit 53 that reciprocates in the direction, a transport unit 54 that transports the print medium in the sub-scanning direction, which is the flow direction, and a sensor group 55 are provided. In addition, the printer 50 includes an interface 56 for connecting to the computer 10 and a non-volatile memory 57. The printing medium is generally printing paper, but it is needless to say that the printing medium can be applied to various media such as resin media other than paper. In the present embodiment, printing is performed by reciprocating the head unit 52 in a direction (main scanning direction) perpendicular to the print medium feeding direction (sub-scanning direction). The present invention can also be applied to a case where printing is performed by sending only a print medium with the print head fixed.

  FIG. 2 is a diagram showing the nozzles of the print head. The head unit 52 includes a print head 52a having a plurality of ejection nozzles assigned to each color ink as shown in FIG. In the figure, KCMY indicates a nozzle row to which black ink, cyan ink, magenta ink, and yellow ink are assigned, and # 1 to # 90 are numbers assigned to the respective nozzles. Here, the most downstream side is # 1 nozzle, and the most upstream side is # 90 nozzle. The interval between the nozzles is the nozzle pitch, and the interval between the rasters in the sub-scanning direction when actually printing is the raster pitch. In this embodiment, the nozzle pitch is 1/90 inch while the raster pitch is 1/720 inch. Since the nozzle pitch and the raster pitch are thus different, the interlace module 22 receives the print data generated by the halftone module 21, selects raster data at a predetermined interval that can be printed by each nozzle, and outputs the print data to the print head 52a. Will be output. A more detailed selection method is omitted here.

  The carriage unit 53 reciprocates the print head 52a in the main scanning direction. Although a specific mechanism is omitted, the color ink dots ejected from the print head 52a are controlled by the control unit 51 and printed. A reciprocating operation is performed in synchronization with the discharge timing so as to adhere to a predetermined position in the main scanning direction on the medium.

  FIG. 3 is a schematic configuration diagram of the transport mechanism. The transport unit 54 includes a transport mechanism. The main structure of the transport mechanism is an upstream for transporting the print medium by rotating a predetermined amount while holding the print medium between the upstream side and the downstream side with a print head 52a as shown in FIG. A side conveyance roller 54a and a downstream side conveyance roller 54b are provided. For convenience, the upstream side is simply referred to as a conveyance roller 54a, and the downstream side is referred to as a paper discharge roller 54b. Since the print medium is transported from the upstream side to the downstream side, the print medium is first sandwiched by the transport roller 54a, and is then sandwiched by both the transport rollers 54a and 54b from when the leading end reaches the paper discharge roller 54b. Further, the paper is nipped only by the paper discharge roller 54b from the time when the rear end passes through the conveyance roller 54a after being conveyed.

  FIG. 4 is a diagram illustrating a situation in which kicking occurs in the transport mechanism. As shown in the figure, when the trailing edge of the printing medium leaves the conveyance roller 54a, the stable conveyance state is shifted to an unstable state, and this behavior is called kicking.

  FIG. 5 shows the conveyance accuracy before and after the occurrence of kicking (the deviation from the target conveyance position is shown). On the + side, the actual conveyance position is downstream of the target conveyance position and the conveyance amount is large. In the negative side, the actual transport position is on the upstream side of the target transport position and the transport amount is reduced. It can be seen that the actual conveyance position does not reach the target conveyance position immediately after kicking.

  In the present embodiment, since the second conveyance correction unit eliminates the disturbance in accuracy due to the kicking, a predetermined correction value is applied to the conveyance amount. In other words, by adding the correction value to the transport amount during the transport period including the timing at which kicking occurs and issuing an instruction to transport further ahead of the originally required target transport position, the transport amount actually generated by kicking is reduced. Offset the shortage.

  Here, in order to further improve the accuracy, it has been found that it is desirable that the kick occurs in the middle (approximately the center) of the conveyance period. For this reason, as will be described in detail later, an alignment correction amount is applied.

(2) First Conveyance Correction Means By the way, it has been found that the conveyance mechanism in the conveyance unit 54 has an error in the feed amount even during normal operation. Although this is a very small feed error, the elimination of such a small feed error is also an important factor in order to perform a finer print with a narrower raster pitch. Therefore, in order to solve the above-mentioned feeding error, a predetermined measurement pattern is printed by the printer 50, read with high precision by the scanner 60, and the image data obtained by reading is processed by the computer 10. The correction value of the feed amount is obtained. Such processing is realized by the correction data creation software 40 shown in FIG.

  FIG. 6 shows an example of a measurement pattern. Under the control of the correction data creation software 40, the printer 50 causes the print head 52a to rotate the transport roller 54a by 1/4 rotation with respect to a predetermined print medium. Color ink is ejected using only predetermined nozzles, for example, # 90 nozzles, and lines are printed in the main scanning direction. By repeating this from the front end to the rear end of the print medium, lines are printed at regular intervals as shown in FIG. Although changing the length of the line depending on the part has another purpose, it is omitted here.

  In the case where a feeding error occurs, the interval between the lines is not actually constant, and there is a shift corresponding to each conveying position when the printing medium is gradually conveyed. Based on the image data read by the scanner 60, the correction data creation software 40 obtains a deviation between the target transport position (L1) obtained through processing for eliminating various reading errors and the actual transport position. Then, a feed amount correction value is calculated for each target transport position, and the calculated correction value is written in the memory 57 of the printer 50. Here, the target transport position is the distance from the leading edge of the print medium, and the feed amount correction value is the feed amount to be increased or decreased at the target position. In addition, although it is an application example that the correction value of the feed amount to be applied between a certain target transport position and the next target transport position is proportional distribution, a more specific application method is omitted here.

  Based on a plurality of target transport positions stored in the printer 50 and correction values of the feed amounts, the interlace module 22 calculates and applies correction values to be applied according to individual target transport positions at the time of printing. The first conveyance correction means. The interlace module 22 outputs a print command to the printer 50 based on the print data generated by the halftone module 21, and at this time, a paper feed conveyance instruction to the conveyance mechanism is also included. For this reason, if the correction value determined by the first transport correction unit is added and a paper transport instruction is issued to the printer 50, the transport error is canceled and the transport error does not occur to the original target transport position. It becomes possible to make it.

  The second transport correction means described above adds a correction value for kicking to the transport amount during a transport period sandwiching the timing at which the kicking occurs based on the transport position of the print medium grasped by the interlace module 22. It will be.

(3) Density Correction Unit The printer driver 20 includes a BRS module 23 in addition to this. The BRS module 23 constitutes density correction means, and here, density correction realized by the density correction means will be described. There is unevenness in the ejection direction of each nozzle of the print head 52a. In other words, even if you intend to perform printing evenly, color ink is regularly ejected from one nozzle toward the upstream side, and color ink is regularly ejected from one nozzle toward the downstream side. In actuality, the printed result may appear to be shaded. When printing with the printer 50, the positional relationship between each raster and the nozzle is actually determined uniquely. Therefore, the measurement pattern is printed, the unevenness of the shading is measured, and printing is performed in advance so as to eliminate the unevenness. If the correction value is reflected on the data side, it is possible to prevent such uneven shading during subsequent printing.

  FIG. 7 shows this measurement pattern. Each nozzle row to which each color ink is assigned has a gradation pattern composed of a plurality of shades extending in the sub-scanning direction and arranged in the main scanning direction. More specifically, a nozzle row to which K ink is assigned from the left side of the drawing is used to print a non-printing area, a lightest density area, an intermediate density area, and a darkest area, and then A similar gradation pattern is printed on the nozzle row to which C ink is assigned, the nozzle row to which M ink is assigned, and the nozzle row to which Y ink is assigned. The reason for printing a plurality of density patterns is that there is a difference in the shading unevenness that appears for each density.

  The print data for printing the measurement pattern is constant from the lower end to the upstream on the print medium, but the conveyance during printing is divided into three patterns depending on the relative positional relationship between the print head 52a and the print medium. Yes.

  FIG. 8 schematically shows an upper end process, a normal feeding unit, and a lower end process corresponding to these three patterns. In the figure, for ease of understanding, the nozzle pitch is four times the raster pitch, and the number of nozzles is simply four. Originally, the print medium is transported and the print head is at a fixed position relative to the transport direction, but the side of the print head can be understood so that the relative position with respect to the print head when the print medium is transported can be understood. Is shifted from the top to the bottom by the transport amount of the print medium.

  As described above, the nozzle pitch and the raster pitch are different, and it is necessary to prevent the print head and the print medium from interfering at the upper end and the lower end of the print medium. For this reason, in order to fill the entire raster, it is necessary to wrap the range in which the print head 52a is reciprocated in the main scanning direction over a predetermined number of times. In the example shown in the figure, a printing process called an upper end process that conveys the printing medium at almost every raster pitch, a printing process called a normal feeding part that conveys the printing medium by the sum of the nozzle pitch and the raster pitch, and a raster pitch again almost again. The positions of the print heads to be wrapped in each of the printing processes called the lower end process for conveying the print medium every time are shown. Of course, there are differences in the specific printing process depending on the number and pitch of the nozzles, but this is roughly the classification.

  When printing a measurement pattern, regardless of the actual top and bottom edges of the print medium, the print data of the above gradation pattern is used within the range that fits within the print medium. Printing is performed in each printing process.

  Then, the obtained printed matter is read by the scanner 60, and the density generated for each density and each raster is measured in each of the upper end process, the normal feeding unit, and the lower end process. Theoretically, it is for each raster, but in reality, the shading may be measured in units of a plurality of rasters. From this measurement result, the density in each raster unit in the upper end process, the density in each raster unit in the normal feeding unit, and the density in each raster unit in the lower end process are known. In order to prevent the occurrence of light and shade in this way, in the present embodiment, the print data of the darkened portion is corrected to be thinned in advance, and the print data of the thinned portion is corrected to be darkened so that the actual print data is darkened. We will cancel the shading in the printing result. A description of a specific method for determining the target density and for determining the correction value based on the difference between the target density and the printing result is omitted here. The result is the correction value of the gradation for each raster in the upper end process, the normal feeding unit, and the lower end process, and the gradation value in the multi-gradation of the print data and the corresponding corrected value The correction value is held as a gradation value table. Note that what is shown in FIG. 7 is only four levels of density, and there are not only the number of gradations of the print data, so the missing gradation values are specified using a known interpolation operation.

  Since such a correction value varies depending on each printer 50, it is stored in the memory 57 arranged in each printer 50, and the printer driver 20 communicates with the printer 50 to read the correction value at the time of printing. Become.

(4) Second Conveyance Correction Unit FIG. 9 is a diagram for explaining the second conveyance correction unit.
As described above, at the time of printing, the printing process in the upper end process, the printing process in the normal feeding unit, and the printing process in the lower end process are performed. When borderless printing is performed on a certain print medium, an area larger than the paper size is set as a print area as shown in the figure. Then, the printing process is performed so that the nozzles of the print head 52a cover the entire range of the print area. In order to start printing from the upper end of the virtual print area, the upper end process starts printing from a position (print start raster) having a relative positional relationship as shown in the figure with respect to the print medium. Then, the printing process in the normal feeding unit is started from the position where the entire raster can be covered by the printing process in the normal feeding unit. When the print medium is close to the rear end, the print processing in the lower end process is performed so that the nozzles of the print head 52a cover the rear end of the virtual print area.

As shown in the figure, if the upper end process is simply aligned with the upper end of the printing area to determine the printing start raster, the kicking position is generated at a position where the conveying range is deviated in one pass in the normal feeding unit. As described above, in order to correct the kicking, it is preferable to generate it at the middle (substantially the center) of the conveyance range in one pass rather than at such a biased position.
Since the kicking position is determined by the distance from the rear end of the print medium, it can be understood that the start position of the upper end process may be advanced in order to generate the kicking position in the middle of the transport range in one pass. Since the print medium cannot be returned, if the kicking position is generated upstream of the middle of the conveyance range in one pass, the upper end processing start position is advanced so as to be generated in the middle of the next one pass. I must.

  FIG. 10 shows a state in which the start position of the upper end process is advanced in this way so that the kick position is adjusted to the middle of the conveyance range in one pass. However, if the top edge processing is simply advanced, the print area is also shifted. Therefore, in order not to shift the print area, the start position of the top edge processing is advanced, but the print start raster must be delayed by that amount. . The amount to be delayed is the alignment amount, and this region is called a mask in the figure.

However, the printing area varies depending on the printing conditions.
FIG. 11 shows an example of bordered printing in which the margin is set to 3 mm. Again, while adjusting the start position of the top edge process so that it is in the middle of the conveyance range in one pass with the kicking position, the print start raster is delayed by that amount in the top edge process so that the print area does not shift. . The alignment amount at this time is different from that in the case of borderless printing described above. Thus, the correction of the kicking can be realized by adjusting the start position of the upper end process and the print start raster according to the printing conditions.

  The target transport position managed by the interlace module 22 is set at the time of each transport while performing the upper end processing and the normal feeding unit. Therefore, while the first transport correction unit reflects the correction value of the feed amount corresponding to each target transport position, the second transport correction unit corrects the correction value during the transport period based on the information on the target transport position. It is not a hindrance to reflect each other repeatedly.

(5) Problems of Density Correction Unit However, the density correction unit corrects the density in each raster of the upper end process, the normal feeding unit, and the lower end process. For this reason, when the print start raster is delayed while the start position of the upper end process is advanced, if the correction value of the light and dark process corresponding to the raster position in the print area is applied, the nozzle used when measuring the light and dark The nozzle used for printing after adjustment is not compatible. The present invention prevents the original density correcting means from functioning due to the displacement of the nozzle in such a case.

  FIG. 12 schematically shows the principle. Originally, the appearance of shading corresponds to the use of nozzles. Therefore, in the printing process following the upper edge process, the normal feeding part, and the lower edge process, the start position of the first upper edge process is used as a reference regardless of the print start raster. Apply correction values based on raster position. Therefore, when a registration amount is required for performing skip correction at the time of borderless printing, the actual printing raster position is shifted by the above-mentioned registration amount, and the density correction unit performs the actual printing raster. A correction value to be applied to a raster position shifted by the same alignment amount with respect to the position is output. Also, with regard to the alignment amount required for printing with a margin of 3 mm, the actual printing raster position will be shifted by the same alignment amount, and the density correction means will have the same alignment amount with respect to the actual printing raster position. The correction value to be applied to the raster position shifted by this amount is output.

(6) Flow of Print Processing FIG. 13 shows a flowchart corresponding to a program for realizing such print control by a computer. This flowchart schematically shows print control performed when the printer driver 20 realized by software in the computer 10 executes the functions of various modules. Mainly, the flowchart shows processing programs in the interlace module 22. Equivalent to.

  Step S100 is a series of processes performed by acquiring the printing conditions. As printing conditions, at least the type of printing medium (indirect acquisition of printing medium length information) and margin information at the time of printing (margins for borderless printing and margined printing) in order to cope with skipping correction is required.

  FIG. 14 shows an example of a user interface screen for acquiring these two printing conditions. The type of print medium is specified in the upper part of the drawing, and it is possible to select marginless printing or bordered printing in the lower part of the drawing. The designated result is acquired as a printing condition as described above. These printing conditions are necessary for determining the start position of the upper end process, and are used for determining the alignment amount. However, these are the minimum information required for the correction of the kicking position, and the correction value varies depending on various conditions such as the type of print medium and print quality in the first transport correction means and density correction means. Other printing conditions are also acquired.

  More specifically, in step S102, a kick correction position and a correction amount are acquired. Here, communication with the printer 50 is performed, and a correction position that is a position at which kicking occurs recorded in the memory 57 of the printer 50 and a correction value that is measured and recorded in advance corresponding to the printing conditions are acquired. In step S106, a target transport position to be applied by the first transport correction unit and a feed amount correction value corresponding to the target transport position are acquired. In step S108, the alignment amount is determined based on the skip correction position, the print medium length, and printing conditions such as borderless printing and bordered printing.

  The next step S110 is a series of upper end processing. At the start of the top edge processing, the application generates image data to be printed and outputs it to the printer driver 20, and the halftone module 21 interlaces the print data that has undergone color conversion and gradation conversion to make the halftone into halftone. It is necessary to be able to output to the module 22. However, as described above, the density correction means in the BRS module 23 cannot output a correction value for density correction unless the alignment amount is determined.

  Therefore, in the printer driver 20, before the halftone module 21 generates the print data, the interlace module 22 determines the alignment amount based on the printing conditions, and the alignment amount is used as the density correction unit of the BRS module 23. Notice. After that, the halftone module 21 halftons the print data, but before that, notifies the BRS module 23 of the raster position, and the BRS module 23 adds the alignment amount to the corresponding raster position, and the nozzle to be actually used. The correction value is output to the halftone module 21 after eliminating the deviation. The halftone module 21 reflects the correction value in the multi-tone print data and then halftones, and outputs the halftoned print data to the interlace module 22.

  In step S112, the interlace module 22 executes the start position of the printing process by the upper end process earlier by the alignment amount. In other words, the print medium is positioned upstream by the alignment amount when printing in the upper end process is started. Next, in step S114, output of halftoned print data is started as a print command corresponding to the nozzle row of the print head 52a. At this time, the print start raster is delayed upstream by the alignment amount. Position. Further, the print data output in step S116 is obtained by applying density correction based on the correction value obtained by shifting the alignment amount as described above.

  When the print medium is transported in parallel with print data output, a target transport position is set for each transport. Accordingly, in step S118, the conveyance is performed while reflecting the correction value of the feed amount obtained for each target conveyance position.

  When the upper end processing is completed, the normal feeding unit print processing is subsequently performed in step S120. Print data is output in step S122. That is, the printing process of the normal feeding unit is performed continuously from the state in which the alignment amount is applied in the upper end process. In addition, a feed amount correction value corresponding to the target transport position is applied to the paper feed of the print medium in step S124.

  However, in step S126, it is determined whether or not the kick correction position will be straddled in the next conveyance period. If YES, the correction value for kick correction is added to the paper feed in step S128. Apply. As described above, the center of the next conveyance which crosses the kick correction position is exactly in the middle. Therefore, although the print medium changes from the state of being nipped by the conveyance roller 54a to the state of not being nipped, the feeding amount is controlled so as to cancel the deviation that is expected to occur, and the kicking correction is performed. Since the position surely occurs in the middle of the transport section, it is guaranteed that the correction is applied with high accuracy.

  In other words, the deviation of the feed amount of the printing medium that occurs regularly is eliminated, the shortage of the feed amount due to kicking is reliably eliminated accurately, and the density correction is also performed in spite of the application of the alignment amount. That is, it was applied without deviation.

  Note that when the kicking correction position is not straddled in the printing process of the normal feeding unit, step S128 is not executed, and therefore the feed amount correction value corresponding to only the initial target transport position is applied.

  When the normal feeding unit 120 reaches the final position, the lower end process printing process is performed in step S130. Here, the print data corresponding to the printing process of the lower end process is generated continuously from the state in which the alignment amount is applied in the upper end process in step S132. Apply a correction value for the feed amount corresponding to the transport position.

As described above, based on at least the type of printing medium and the printing condition for designating the borderless printing and the bordered printing, the alignment amount is determined so as to occur in the middle of one pass with the skip correction in step S100. In step S110, the upper end processing is advanced by the same alignment amount, so that the skip correction position generated during the printing process of the normal feeding portion in step S120 always occurs in the middle of one pass, and only the same alignment amount. By delaying the print start raster in the upper end process, the correction value for density correction is applied without deviation in the upper end process in step S110, the normal feeding unit in step S120, and the lower end process in step S130. Therefore, it is possible to realize printing with high accuracy.

1 is a block diagram of a printing system to which a printing control apparatus is applied. It is a figure which shows the nozzle of a print head. It is a schematic block diagram of a conveyance mechanism. It is a figure which shows the condition where kicking occurs in a conveyance mechanism. It is a figure which shows the shift | offset | difference of the conveyance amount before and behind the timing of kicking. It is a figure which shows the pattern for a measurement for a 1st conveyance correction means. It is a figure which shows the pattern for a measurement for a density correction means. It is a figure explaining each printing process of an upper end process, a normal sending part, and a lower end process. It is a figure for demonstrating the principle of a 2nd conveyance correction means. It is a figure for demonstrating the principle of the 2nd conveyance correction means at the time of borderless printing. It is a figure for demonstrating the principle of the 2nd conveyance correction means at the time of printing with a border. It is a figure which shows the principle which eliminates the influence which position alignment amount has on density correction. 5 is a flowchart reflecting a print control apparatus of the present invention. It is a figure of the user interface screen for acquiring printing conditions.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Computer, 20 ... Printer driver, 21 ... Halftone module, 22 ... Interlace module, 22 ... BRS module, 30 ... Application, 40 ... Correction data creation software, 50 ... Printer, 51 ... Control unit, 52 ... Head unit, 53 ... Carriage unit, 54 ... Conveyance unit, 55 ... Sensor group, 56 ... Interface, 57 ... Non-volatile memory, 60 ... Scanner, 52a ... Print head, 54a ... Conveyance roller, 54b ... Conveyance roller.

Claims (6)

A plurality of printers that transport a predetermined print medium in the sub-scanning direction and record on the print medium using the print head, corresponding to a plurality of target transport positions relative to the print head of the print medium. A first transport correction unit that holds the correction value of the feed amount and causes the printer to perform the corrected transport corresponding to the target transport position;
Density correction means for performing density correction for each predetermined raster based on density deviation data measured in advance in each of the upper end process, the normal feeding unit, and the lower end process when printing with the printer;
A printing control apparatus comprising: a second conveyance correction unit configured to perform conveyance corrected by the printer based on data of a feeding error caused by a relative positional relationship between a conveyance mechanism in the printer and an end portion of the print medium. And
Based on the printing conditions to be applied, the upper end of the upper end process is controlled while increasing the timing at which the upper end process is started so that the correction applied by the second transport correction unit is applied at a transport timing specified in advance. A positioning amount applying means for controlling the lowering of the raster from which printing is started at the time of processing, and for shifting the raster to which subsequent density correction is applied to the density correcting means by the amount of the lowered raster. A printing control apparatus comprising: The multi-tone image data in a color space different from that of the printer is input and color-converted to multi-tone image data in the color space of the printer, and the converted image data can be recorded by the printer. A halftone module that converts gradation into gradation print data;
An interlace module that inputs the low-gradation print data and generates raster data when the print head performs printing while performing the main scanning and full scanning;
The density correction means is for causing the halftone module to correct the density corresponding to the raster position for the image data color-converted to the printer color space, and is applied by the registration amount application means. The print control apparatus according to claim 1, wherein the density correction is performed by lowering the raster position by the amount of the raster.   The alignment amount applying means is configured such that the timing at which the conveyance roller of the conveyance mechanism in the printer changes from the state in which the printing medium is nipped to the state in which the printing medium is not nipped is generated at the approximate center of one conveyance in the normal feeding unit. 3. The control according to claim 1, wherein control is performed to raise the timing at which the upper end processing is started, while lowering the raster at which printing is started at the time of the upper end processing. The printing control apparatus described.   The position adjustment amount applying unit acquires, as the printing condition, information on whether printing is bordered or borderless printing, and the type of print medium, according to any one of claims 1 to 3. The printing control apparatus described. For a printer that transports a predetermined print medium in the sub-scanning direction and records on the print medium using a print head, a plurality of print media corresponding to a plurality of target transport positions relative to the print head of the print medium A first transport correction step for causing the printer to perform corrected transport in correspondence with each target transport position while holding a correction value of the feed amount;
A density correction step for correcting the density for each predetermined raster based on the density deviation data measured in advance in each of the upper end process, the normal feeding unit, and the lower end process when printing with the printer;
A second transport correction step for performing transport corrected by the printer based on feed error data generated by the relative positional relationship between the transport mechanism in the printer and the edge of the print medium;
Based on the applied printing conditions, the upper end of the upper end process is controlled while increasing the timing at which the upper end process is started so that the correction applied in the second transport correction step is applied at the transport timing specified in advance. A registration amount application step for controlling the lowering of the raster for which printing is started at the time of processing, and for shifting the raster to which the subsequent density correction is applied by the amount of the lowered raster for the density correction step. A printing control method comprising: A medium in which a printing control program for controlling a printing apparatus by a computer is recorded,
For a printer that transports a predetermined print medium in the sub-scanning direction and records on the print medium using a print head, a plurality of print media corresponding to a plurality of target transport positions relative to the print head of the print medium A first transport correction function for causing the printer to perform corrected transport in correspondence with each target transport position while holding a correction value of the feed amount;
A density correction function for performing density correction for each predetermined raster on the basis of deviation data of density measured in advance in each of the upper end process, the normal feeding unit, and the lower end process when printing with the printer;
A second transport correction function for performing transport corrected by the printer based on data of a feed error generated by a relative positional relationship between a transport mechanism in the printer and an end of the print medium;
Based on the applied printing conditions, the upper end of the upper end process is controlled while increasing the timing at which the upper end process is started so that the correction applied in the second transport correction step is applied at the transport timing specified in advance. A registration amount application function for controlling the lowering of the raster where printing is started at the time of processing, and shifting the raster to which the subsequent density correction is applied by the amount of the lowered raster for the density correction step. A medium having recorded thereon a print control program characterized by causing a computer to realize the above.

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