JP2004216615A - Printer, program and computer system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To realize a printer in which a medium is carried by an amount suitable for print conditions for being printed. <P>SOLUTION: The printer comprises an array of ink ejecting parts, and a carrying mechanism for carrying a medium along the array direction of the array ink ejecting parts, and alternately repeats a printing operation for printing on the medium and an carrying operation for carrying the medium by a target carrying amount equal to the array length of the array of ink ejecting parts wherein the target carrying amount is altered based on the print conditions for printing in the printing operation. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a printing apparatus, a computer program, a computer system, and a printing method, and in particular, a printing apparatus, a computer program, a computer system, and a method of printing by forming dots by ejecting ink on a transported printing medium. Related to the printing method.
[0002]
[Prior art]
As a printing apparatus that forms dots by discharging ink on a medium to be conveyed and prints, for example, a paper conveying unit that conveys printing paper as a medium to be printed, and an ink that discharges ink onto the printing paper 2. Description of the Related Art An ink jet printer having a nozzle as a discharge unit is known (see Patent Document 1). Since an ink jet printer forms an image with a large number of dots, it is necessary to accurately form each dot at a predetermined position. However, when the conveyance accuracy of the conveyed printing paper is poor, dots are formed at positions different from the target dot formation positions, and the image quality deteriorates. For this reason, in order to optimize the transport amount of the printing paper, a plurality of predetermined correction amount selection patterns, which are obtained by adding correction amounts that are slightly different from the set transport amount, are printed. An appropriate correction amount is selected, and correction is performed with the selected correction amount before printing.
[0003]
[Patent Document 1]
JP 2001-71475 A
[0004]
[Problems to be solved by the invention]
By the way, an ink jet printer can form a plurality of types of dots having different shapes in order to print according to a print mode, an image to be printed, and the like.
On the other hand, the correction amount selection pattern is printed using any one of a plurality of types of dots having different shapes.
For this reason, if the type of dots used when printing an image is different from the type of dots used when printing the correction amount selection pattern, the printing paper is not transported with an appropriate transport amount. However, there is a problem that image quality may be reduced.
[0005]
The present invention has been made in view of such a problem, and an object of the present invention is to provide a printing apparatus, a computer program, a computer system, and a computer that convey and print a medium by a conveyance amount suitable for printing conditions for printing. And a printing method.
[0006]
[Means for Solving the Problems]
A main aspect of the present invention includes an ink ejection unit row in which ink ejection units that eject ink are arranged in a row, and a transport mechanism that transports a medium along a column direction of the ink ejection unit row. In a printing apparatus that alternately repeats a printing operation of ejecting ink from and printing on the medium and a transport operation of transporting the medium with a row length of the ink discharge unit row as a target transport amount, the printing operation includes: A printing apparatus characterized in that the target transport amount is changed based on printing conditions for printing.
Other features of the present invention will become apparent from the description of the present specification and the accompanying drawings.
[0007]
BEST MODE FOR CARRYING OUT THE INVENTION
=== Disclosure Overview ===
At least the following matters will be made clear by the description in this specification and the accompanying drawings.
An ink ejection section array in which ink ejection sections for ejecting ink are arranged in a row, and a transport mechanism for transporting a medium along the row direction of the ink ejection section row, and ejecting ink from the ink ejection section row. In a printing apparatus that alternately repeats a printing operation for printing on the medium and a transporting operation for transporting the medium with the row length of the ink ejection unit row as a target transporting amount, the printing conditions for printing in the printing operation are A printing apparatus configured to change the target transport amount based on the information.
According to such a printing apparatus, the medium is transported by the target transport amount suitable for the printing conditions for printing, so that the image quality can be improved. That is, it is possible to prevent the images printed in the printing operation before and after the medium is conveyed from being overlapped or separated too much, thereby causing white streaks or black streaks in the image.
[0008]
In the printing apparatus, it is preferable that the printing condition is a condition that affects a shape of a dot formed on the medium by the ink ejected from the ink ejection unit.
According to such a printing apparatus, since the medium is transported by the target transport amount suitable for the shape of the dots formed on the medium, the boundary of the image printed by the printing operation before and after the transport of the medium is performed. It is possible to suppress the occurrence of white streaks and black streaks at the site.
[0009]
In the printing apparatus, it is preferable that the printing condition is a condition that affects the length of dots formed on the medium by the ink ejected from the ink ejection unit in the column direction.
According to such a printing apparatus, since the medium is transported by the target transport amount suitable for the length of the dots formed on the medium in the column direction, the printing operation before and after the transport of the medium is performed. It is possible to further suppress the occurrence of white stripes and black stripes at the boundary portion of the printed image.
[0010]
In such a printing apparatus, it is desirable that the printing condition is the type of the medium.
According to such a printing apparatus, since the medium is transported by the target transport amount suitable for the type of the medium, it is possible to transport the medium in consideration of ink bleeding due to a difference in the medium, It is possible to further suppress the occurrence of white streaks and black streaks at a boundary portion of an image printed by a printing operation before and after a medium is conveyed.
[0011]
In such a printing apparatus, it is desirable that the printing condition is image quality of an image to be printed.
According to such a printing apparatus, the medium is transported by the target transport amount suitable for the image quality of the image to be printed, so that the medium is transported by the transport amount corresponding to the printing condition changed due to the difference in the image quality. It becomes possible.
[0012]
In the printing apparatus, it is preferable that the printing condition is related to an amount of ink ejected from the ink ejection unit in order to form one dot.
According to such a printing apparatus, it is possible to convey the medium in consideration of ink bleeding due to a difference in the amount of ink to be ejected and the dot size to be formed, and to perform printing before and after the medium is conveyed. It is possible to further suppress the occurrence of white stripes and black stripes at the boundary portion of the image printed by the operation.
[0013]
In the printing apparatus, it is preferable that the change of the target transport amount is performed based on print information input together with a print command signal for performing the printing.
According to such a printing apparatus, the target transport amount is changed based on the print information input together with the print command signal. Thus, the target transport amount can be easily changed.
[0014]
In the printing apparatus, the change of the target transport amount may be performed based on print data for performing the first printing operation on the medium.
According to such a printing apparatus, the target carry amount is changed based on the print data actually printed in the printing operation, so that the carry amount can be accurately changed.
[0015]
In the printing apparatus, the target transport amount is set to a target transport amount corresponding to the printing condition in a target transport amount determining pattern printed under predetermined printing conditions, and the target transport amount is set based on the set target transport amount. It is desirable that a target transport amount corresponding to another printing condition is set.
According to such a printing apparatus, it is possible to set a target transport amount corresponding to a plurality of printing conditions by using one type of target transport amount determination pattern, and it is possible to reduce the trouble of printing the target transport amount determination pattern. In addition, waste of the medium, ink, and the like can be suppressed.
[0016]
In such a printing apparatus, the target transport amount is a target transport amount corresponding to another printing condition based on a target transport amount corresponding to the printing condition in a target transport amount determining pattern printed under predetermined printing conditions. May be set to a correction amount to be corrected with respect to the transport amount when transported at the reference target transport amount.
According to such a printing apparatus, it is possible to set a target transport amount corresponding to a plurality of printing conditions by using one type of target transport amount determination pattern. Even if there is, the medium can be properly transported without changing the correction values corresponding to other printing conditions.
[0017]
In such a printing apparatus, it is desirable to have a data table in which the target transport amount is associated with a plurality of printing conditions.
According to such a printing apparatus, it is possible to easily realize transport control for properly transporting a medium based on a data table in which a target transport amount and a plurality of printing conditions are associated.
[0018]
In this printing apparatus, when the dots to be formed are larger than the dot size formed by the printing conditions in which the target transport amount determining pattern is formed, it is preferable that the target transport amount is extended.
According to such a printing apparatus, when a dot having a size larger than the dot size formed by the printing condition in which the target transport amount determination pattern is formed is printed by the printing operation before and after the medium is transported. The printed images are printed at a position closer to the target transport amount determining pattern. However, by extending the target transport amount, it is possible to arrange and print those images at appropriate positions.
[0019]
In such a printing apparatus, when the dots to be formed are smaller than a dot size formed by printing conditions in which the target transport amount determining pattern is formed, it is desirable that the target transport amount is reduced.
According to such a printing apparatus, when a dot having a size smaller than the dot size formed by the printing condition in which the target transport amount determination pattern is formed is printed by the printing operation before and after the medium is transported. The resulting images are printed at positions separated from the target transport amount determination pattern. However, by shortening the target transport amount, it becomes possible to arrange and print those images at appropriate positions.
[0020]
In addition, an ink ejection unit row in which ink ejection units that eject ink are arranged in a row, and a transport mechanism that transports the medium along the row direction of the ink ejection unit row,
In a printing apparatus, a printing operation of ejecting ink from the ink ejection unit row and printing on the medium, and a transport operation of transporting the medium with the row length of the ink ejection unit row as a target transport amount, are alternately repeated.
The target conveyance amount is input together with a print command signal for executing the printing, and based on the image quality of the image printed in the printing operation and the type of the medium,
The target transport amount is based on a target transport amount corresponding to the printing condition in a target transport amount determination pattern printed under predetermined printing conditions, and the target transport amount corresponding to other printing conditions is the same as the reference. The transport amount when transported at a target transport amount is set with a correction amount to be corrected,
A data table in which the target transport amount and a plurality of printing conditions are associated;
If the dots to be formed are larger than the dot size formed by the printing conditions for forming the target transport amount determination pattern, the target transport amount is extended,
If the dots to be formed are smaller than the dot size formed by the printing conditions for forming the target transport amount determining pattern, the target transport amount is reduced.
[0021]
According to such a printing apparatus, it is possible to transport the medium with a target transport amount suitable for printing conditions such as the image quality of the image to be printed and the type of the medium, and to perform the printing operation before and after the medium is transported. It is possible to easily prevent the printed images from being overlapped or separated from each other and causing white stripes or black stripes in the image.
[0022]
Further, an ink ejection section array in which ink ejection sections for ejecting ink are arranged in a row, and a transport mechanism for transporting a medium along the row direction of the ink ejection section row, and ink from the ink ejection section row A printing operation in which the printing operation is performed by a printing apparatus that alternately repeats a printing operation of ejecting and printing on the medium and a carrying operation of carrying the medium with the row length of the ink ejection unit row as a target carrying amount. A computer program for realizing a function of changing the target transport amount based on a condition can also be realized.
[0023]
Further, a computer main body, and an ink discharge unit row connected to the computer main body and having ink discharge units for discharging ink arranged in a row, and a conveyance for conveying a medium along the row direction of the ink discharge unit row A printing operation for ejecting ink from the ink ejection unit row and printing on the medium, and a transport operation for transporting the medium with the row length of the ink ejection unit row as a target transport amount are alternately repeated. And a printing device, wherein the target transport amount is changed based on printing conditions for printing in the printing operation.
[0024]
Further, an ink ejection section array in which ink ejection sections for ejecting ink are arranged in a row, and a transport mechanism for transporting a medium along the row direction of the ink ejection section row, and ink from the ink ejection section row A printing method for printing by a printing apparatus that alternately repeats a printing operation of discharging and printing on the medium and a transporting operation of transporting the medium with the row length of the ink discharge unit row as a target transporting amount, wherein the printing is performed. It is also possible to realize a printing method in which the target transport amount is changed based on printing conditions for printing in operation.
[0025]
=== Overall configuration of device ===
FIG. 1 is a block diagram showing a configuration of a printing system as one embodiment of the present invention. This printing system includes a computer 90 and a color inkjet printer 20 as an example of a printing device. Note that a printing system including the printer 20 and the computer 90 can also be called a “printing device” in a broad sense. The computer 90 includes the computer 90, the color inkjet printer 20, a display device 21 such as a CRT or a liquid crystal display device, and an input device (not shown) such as a keyboard and a mouse, a flexible drive device, a CD-ROM drive device, and the like. Has been built.
[0026]
In the computer 90, an application program 95 operates under a predetermined operating system. The operating system incorporates a video driver 91 and a printer driver 96. For example, an image to be processed given from an application program 95 for performing image retouching or the like is transmitted to the printer 20 or the display device 21 via these drivers. Is output.
[0027]
When the application program 95 issues a print command, the printer driver 96 of the computer 90 receives image data from the application program 95 and converts it into print data PD to be supplied to the printer 20. Inside the printer driver 96, a resolution conversion module 97, a color conversion module 98, a halftone module 99, a rasterizer 100, a user interface display module 101, a pattern supply module 102 for determining a target transport amount, A color conversion lookup table LUT.
[0028]
The resolution conversion module 97 plays a role of converting the resolution of the color image data formed by the application program 95 into a print resolution. The resolution-converted image data is image information composed of three color components of RGB. The color conversion module 98 converts the RGB image data for each pixel into multi-tone data of a plurality of ink colors that can be used by the printer 20 while referring to the color conversion lookup table LUT. The color-converted multi-tone data has, for example, 256 tone values.
[0029]
The halftone module 99 generates a halftone image data by executing a so-called halftone process. The halftone image data is rearranged by the rasterizer 100 in the order of data to be transferred to the printer 20, and output as final print data PD. The print data PD includes raster data indicating the dot formation state during each main scan, and data indicating the sub-scan feed amount. The halftone process may not be performed, as described later.
[0030]
The user interface display module 101 has a function of displaying various user interface windows related to printing, and a function of receiving a user input in those windows.
[0031]
The target feed amount determining pattern supply module 102 prints a target feed amount determining pattern print used to determine, for example, a correction value of a sub-scan feed amount (also referred to as a “paper feed amount”) for feeding paper as a medium. It has a function of reading the signal TPS from the hard disk 92 and supplying it to the printer 20. In addition, when the target transport amount determination pattern print signal TPS is stored as compressed data, it has a function of expanding the compressed data.
[0032]
The printer driver 96 realizes a function of supplying the print data PD and the target print amount determining pattern print signal TPS to the printer 20. A program for realizing the function of the printer driver 96 is supplied in a form recorded on a computer-readable recording medium. Examples of such a recording medium include a flexible disk, a CD-ROM, a magneto-optical disk, an IC card, a ROM cartridge, a punched card, a printed matter on which a code such as a bar code is printed, and a computer internal storage device (such as a RAM or ROM). Various computer-readable media can be used, such as memory and external storage. Further, such a computer program can be downloaded to the computer 90 via the Internet.
[0033]
The computer 90 including the printer driver 96 functions as a print control device that supplies the print data PD and the target print amount determining pattern print signal TPS to the printer 20 to perform printing.
[0034]
FIG. 2 is a schematic perspective view illustrating a main configuration of the color inkjet printer 20. The printer 20 includes a paper stacker 22, a paper feed roller 24 driven by a paper feed motor 31 (FIG. 4), a platen 26, a carriage 28, a carriage motor 30, and a traction drive driven by the carriage motor 30. A belt 32 and a guide rail 34 for guiding the carriage 28 are provided. A print head 36 having a number of nozzles is mounted on the carriage 28.
[0035]
The print paper P in the paper stacker 22 is fed by a paper feed roller (not shown), transported by a paper feed roller 24, and transported on the surface of a platen 26 in the sub-scanning direction. The carriage 28 is pulled by a pulling belt 32 driven by a carriage motor 30 and moves along a guide rail 34 in the main scanning direction. The main scanning direction is perpendicular to the sub-scanning direction.
[0036]
FIG. 3 is a block diagram showing an electrical configuration of the inkjet printer 20. The printer 20 includes a reception buffer memory 50 for receiving a signal supplied from a computer 90, an image buffer 52 for storing print data, a system controller 54 for controlling the overall operation of the printer 20, a main memory 56, and an EEPROM 58. And The system controller 54 is further connected to a main scanning drive circuit 61 that drives the carriage motor 30, a sub-scanning drive circuit 62 that drives the paper feed motor 31, and a head drive circuit 63 that drives the print head 36. .
[0037]
The main scanning drive circuit 61, the carriage motor 30, the traction belt 32 (FIG. 2), and the guide rail 34 constitute a main scanning driving mechanism. The sub-scanning drive circuit 62, the paper feed motor 31, and the paper feed roller 24 (FIG. 2) form a sub-scanning drive mechanism (also referred to as a "feed mechanism").
[0038]
The print data transferred from the computer 90 is temporarily stored in the reception buffer memory 50. In the printer 20, the system controller 54 reads necessary information from the print data from the reception buffer memory 50, and sends a control signal to each of the drive circuits 61, 62, 63 based on the read information.
[0039]
The image buffer 52 stores print data of a plurality of color components received by the reception buffer memory 50 for each color component. The head drive circuit 63 reads the print data of each color component from the image buffer 52 according to a control signal from the system controller 54, and drives the nozzle array of each color provided in the print head 36 in accordance with the read data.
[0040]
FIG. 4 is a perspective view showing the configuration of the sub-scanning drive mechanism. The power of the paper feed motor 31 is transmitted to the paper feed roller 24 and the paper discharge roller 42 via the gear train 40. The paper feed roller 24 is provided with a driven roller 25, and the discharge roller 42 is also provided with a knurled roller 44 as the driven roller. The printing paper P is sent while being nipped by these rollers, and moves on the platen 26.
[0041]
A code plate 47 is provided on the shaft of the paper feed roller 24, and the code plate 47 constitutes a rotary encoder 46 together with the photo sensor 48. The paper feed amount is determined according to the pulse signal from the rotary encoder 46.
[0042]
=== Encoder ===
Next, the rotary encoder 46 provided on the shaft of the paper feed roller 24 will be described. FIG. 5 is an explanatory diagram schematically showing the configuration of the rotary encoder 46.
The rotary encoder 46 shown in FIG. 5 includes a light emitting diode 48a, a collimator lens 48b, and a detection processing unit 48c. The detection processing unit 48c includes a plurality (for example, four) of photodiodes 48d, a signal processing circuit 48e, and, for example, two comparators 48fA and 48fB.
[0043]
When a voltage VCC is applied to both ends of the light emitting diode 48a via a resistor, light is emitted from the light emitting diode 48a. This light is converged into parallel light by the collimator lens 48b and passes through the encoder code board 47. At this time, the position where the light emitted from the light emitting diode 48a toward the encoder code board 47 is irradiated is, for example, separated from the center of the encoder code board 47 by a distance twice the radius of the paper feed roller 24. Is set to the position That is, half of the arc distance corresponding to the rotation angle of the encoder code board 47 detected by the encoder is the transport distance of the printing paper transported by the paper feed roller 24, that is, the transport distance. In the encoder code board 47, slits are provided at predetermined intervals (for example, 1/180 inch (1 inch = 2.54 cm)) at the irradiation position of light emitted from the light emitting diode 48a.
[0044]
The parallel light that has passed through the encoder code board 47 enters each photodiode 48d through a fixed slit (not shown) and is converted into an electric signal. The electric signals output from the four photodiodes 48d are subjected to signal processing in a signal processing circuit 48e, and the signals output from the signal processing circuit 48e are compared in comparators 48fA and 48fB, and the comparison result is output as a pulse. The pulses ENC-A and ENC-B output from the comparators 48fA and 48fB are output from the encoder 46.
[0045]
=== Conveyance control of printing paper ===
FIG. 6 is a timing chart showing waveforms of two output signals of the rotary encoder 46 at the time of normal rotation and reverse rotation of the paper feed motor.
As shown in FIGS. 6A and 6B, the phase of the pulse ENC-A differs from that of the pulse ENC-B by 90 degrees both in the forward rotation and in the reverse rotation of the paper feed motor 31. When the paper feed motor 31 is rotating forward, that is, when the printing paper P is moving to the discharge side along the transport direction, the pulse ENC-A is changed to the pulse ENC-B as shown in FIG. 6A. 6B, the phase of the pulse ENC-A is delayed by 90 degrees from the phase of the pulse ENC-B, as shown in FIG. 6B. One cycle T of the pulse ENC-A and the pulse ENC-B is equal to the time required for the printing paper P to move a distance corresponding to a half of the slit interval of the encoder code board 47, and the pulse ENC-A and the pulse ENC-B are equal. By conveying the printing paper by counting the output pulse of B, the printing paper P can be moved to a predetermined position. Further, it is possible to recognize the transport distance of the printing paper P actually transported based on the transport amount data of the command data input from the host computer 90 and the slit interval of the encoder code board 47 and the like.
[0046]
=== Print Head Configuration ===
FIG. 7 is a diagram for explaining an arrangement of nozzles included in the print head 36.
As shown in FIG. 7, the print head 36 has a plurality of nozzles arranged in a straight line in the sub-scanning direction, and has six nozzle rows as printing section rows. In the present embodiment, the nozzle row forms a row for each ink color to be discharged, such as a black nozzle row, a cyan nozzle row, a light cyan nozzle row, a magenta nozzle row, a light magenta nozzle row, and a yellow nozzle row. It is not limited to this.
[0047]
The black nozzle row has 180 nozzles # 1 to # 180, and each nozzle is provided with a piezo element (not shown) as a driving element for driving each nozzle to eject ink droplets. . The nozzles # 1,..., # 180 in the black nozzle row are arranged at a constant nozzle pitch D along the sub-scanning direction.
[0048]
The same applies to the cyan nozzle row, light cyan nozzle row, magenta nozzle row, light magenta nozzle row, and yellow nozzle row. That is, each nozzle row has 180 nozzles # 1 to # 180, and is arranged at a constant nozzle pitch D along the sub-scanning direction.
[0049]
Then, at the time of printing, the roll paper P is intermittently conveyed by a predetermined conveyance amount by the paper feed roller 24, and during the intermittent conveyance, the carriage 28 moves in the main scanning direction to eject ink droplets from each nozzle. Is done. However, depending on the printing method, not all nozzles are always used, and only some nozzles may be used.
[0050]
=== Printing by band feed method ===
The printer 20 is capable of printing by two printing methods roughly divided into a so-called interlace method and a band feeding method. In the interlaced printing, when printing one line of image data in the main scanning direction, the print head is scanned a plurality of times, and in each scan, dots are printed at predetermined intervals and scanning is repeated. This is a printing method in which dots are sequentially printed every time. On the other hand, the band feed printing includes a printing operation in which ink is ejected from nozzles while printing the print head 36 in the main scanning direction and printing is performed on paper, and a transport operation in which paper is transported using the nozzle row length as a target transport distance. This is a printing method in which the operation is alternately repeated. According to the present invention, the transport amount of the paper during the band feed printing is corrected.
[0051]
In the band feed printing, when the print head 36 scans once in the main scanning direction, dots are formed in the main scanning direction by the nozzles of the nozzle row. At this time, so-called raster lines in which dots formed by ink ejected from one nozzle are connected are formed by the number of nozzles in the nozzle row. Thereafter, after the paper is conveyed by the length of the nozzle row, the same number of raster lines as in the first scan are printed by the second scan of the print head 36. Here, the row length in which the sheet is transported by one transport operation is obtained by adding the nozzle pitch D to the distance of the nozzle row from the center of the nozzle # 1 to the center of the nozzle # 180. A single transfer operation is executed using the column length as a target transfer distance. That is, a raster line printed by nozzle # 180 by the printing operation performed immediately before the transport operation and a raster line printed by nozzle # 1 by the printing operation performed immediately after the transport operation The sheet is transported with the target transport distance being the transport distance of the paper whose center-to-center distance is the nozzle pitch D.
[0052]
For this reason, when the transport amount by which the paper is actually transported is smaller than the target transport amount, the 180th raster line printed in the printing operation immediately before the transport operation and the printing immediately after the transport operation are performed. The first raster line printed by the operation is formed close to or overlaps with the first raster line, and appears as a black stripe on the image. On the other hand, if the transport amount by which the paper is actually transported is larger than the target transport amount, the 180th raster line printed in the printing operation immediately before the transport operation and the printing operation immediately after the transport operation are performed. The distance from the first raster line printed at is larger than the distance between the other raster lines, and appears as white stripes in the image.
[0053]
=== Relationship between printing conditions and dot size ===
The above-described band feed printing has a higher printing speed than the interlaced printing, but has a feature that the printed image resolution is low and the image quality is inferior. For this reason, in order to improve the image quality in the printing of the band feeding method in which the printing speed is faster than the interlacing method, the resolution in the sub-scanning direction is increased compared to the printing mode of the normal band feeding method so-called “normal mode”. A print mode called “clean mode” is provided. In the “normal mode” and the “clean mode”, printing is performed with dots having different dot shapes from each other. That is, smaller dots are used for dots formed by printing in the "clean mode" for printing an image with a higher resolution.
[0054]
By the way, the dot size varies depending not only on the amount of ink ejected from the nozzles to form one dot, but also on the paper to be printed. For example, there are various types of printing paper, such as plain paper, fine paper, glossy paper, photo paper, and matte paper, and dots formed by each printing paper due to ink bleeding generated when ink is ejected. Of different sizes. For this reason, the control for forming the dots is changed depending on the printing conditions such as the type of paper and the printing mode, and the setting is made so that the dots having a shape suitable for the printing conditions are formed.
[0055]
FIG. 8 is a diagram for explaining dots formed for each printing condition in band-feed printing. In this example, plain paper and fine paper are targeted as the types of paper, and each paper has a “normal mode” and a “fine mode”, and is formed by printing under four printing conditions. The dots are shown. The parameters for changing the dot size include a drive waveform type for discharging ink from the nozzles to form one dot, a discharge frequency for discharging ink from the nozzles to form one dot, and one time. The ink ejection amount by ejection is shown for each printing condition, and a dot image formed by printing under each printing condition is shown.
[0056]
In this example, the type of the drive waveform for forming one dot is set to be changed in accordance with the paper. When printing on plain paper, an A-type drive waveform having three identical unit waveforms is used in a cycle for forming one dot. In the type A drive waveform, the amount of ink ejected by one unit waveform is set to, for example, 15 ng. When printing on fine paper, a B-type driving waveform having two waveforms, large and small, is used in a cycle for forming one dot. In the B-type drive waveform, the amount of ink ejected by the larger waveform is set to, for example, 16 ng, and the amount of ink ejected by the smaller waveform is set to, for example, 8 ng.
[0057]
Then, when the condition for executing the normal mode printing on plain paper is set as the printing condition, ink is ejected three times by three unit waveforms of the A type driving waveform, and the maximum diameter a is obtained by 45 ng of ink. Dots are formed. When the condition for executing the clean mode printing on plain paper is set as the printing condition, ink is ejected twice by two unit waveforms of the A-type driving waveform, and a dot of medium diameter b is formed by 30 ng of ink. Is formed. When a condition for executing normal mode printing on fine paper is set as the printing condition, 24 ng of ink is ejected by two large and small B-type drive waveforms, and a dot having a small diameter c is formed. When the condition for executing the fine mode printing on the fine paper is set as the printing condition, 8 ng of ink is ejected by the smaller one of the B-type drive waveforms, and dots having an extremely small diameter d are formed.
[0058]
The dots corresponding to these conditions, that is, the dot having the maximum diameter a, the dot having the medium diameter b, the dot having the small diameter c, and the dot having the extremely small diameter d have different lengths in the sub-scanning direction. The longest dot is formed in order of the medium diameter b dot, the small diameter c dot, and the extremely small diameter d dot. For this reason, the transport amount in the transport operation performed during each printing operation of the band feed method differs for each printing condition, and when the paper is transported with the same target transport amount in the transport operation when printing under different printing conditions. In addition, white stripes and black stripes are generated depending on printing conditions. In order to prevent this, a correction data table for correcting the target transport amount for each printing condition is provided.
[0059]
FIG. 9 is an example of a correction data table included in the printer 20. In this correction data table, correction values to be used for other conditions are set with a target transport amount used for printing conditions for printing on plain paper in the normal mode as a reference value. This reference value is set by the number of pulses of the rotary encoder 46. That is, the number of pulses required to carry the carry amount suitable for the printing conditions for printing using the dot of the maximum diameter a is used as a reference value, and the dot of the medium diameter b, the dot of the small diameter c, and the dot of the extremely small diameter d are used. For the transport amount used for printing, the correction value of the correction data table is set by converting the difference between the diameter of the dot of the maximum diameter a and the dot of another size into the number of pulses.
A printing operation using the correction data table will be described later.
[0060]
=== Determination of paper feed correction reference value ===
As the reference value of the paper transport amount, the target transport amount determining pattern is printed using the printer 20 under predetermined printing conditions, and the target transport amount suitable for the printed printing condition is determined.
FIG. 10 is an explanatory diagram showing an example of the target transport amount determination pattern. This target transport amount determination pattern is composed of five patches arranged in a line, and has two upper and lower sub-patches. That is, one patch is composed of two sub-patches that are printed by two printing operations performed before and after a single sheet conveyance operation. The five patches are printed such that the target transport amount in the transport operation performed during printing of the two sub-patches is changed by a small amount that can be corrected. For each target transport amount, print the central patch with the ideal transport amount when the printing paper is transported accurately by an ideal device that does not include the precision of parts such as nozzles, assembly precision, etc. The patches having different target transport amounts are printed on both sides of the printer such that the target transport amounts are sequentially changed.
[0061]
Each patch is a gray patch of uniform density in composite black using CMY inks. Such a gray patch reflects both a paper feed error and a dot position error of each color dot. Since the actual image quality of the printed matter is affected not only by the paper feed error but also by the positional error of the dots of each color, from the viewpoint of improving the image quality, a gray patch printed in composite black is used as the target transport amount determination pattern. Is preferred. However, as the target transport amount determining pattern, various other patterns can be used. For example, other types of color patches, patches printed only with black ink, and the like can be used.
[0062]
In the present specification, “composite black” means a gray color reproduced using inks of three hues of CMY, and may be printed using three or more types of inks. For example, when dark ink and light ink can be used for cyan and magenta, respectively, composite black can be printed using these four types of ink and five types of yellow ink.
[0063]
FIG. 11 is a flowchart illustrating a procedure for determining the reference value of the sheet conveyance amount. For example, an operator or a user in a manufacturing process selects a type of printing paper for determining printing conditions, a print mode, and inputs a print command for printing a target transport amount determination pattern, thereby determining a target transport amount. Pattern is printed. FIG. 12 is an explanatory diagram illustrating an example of a user interface window W1 for inputting a print instruction of a target transport amount determination pattern. This window W1 is a utility window in the printer properties, and is provided with input means for selecting the type of print paper and the print mode, and a button B1 for inputting a print instruction for a target transport amount determination pattern. ing. When the user or the like clicks the button B1 (S102), the pattern supply module 102 (FIG. 1) reads out the target transport distance determination pattern print signal TPS from the hard disk 92 and supplies it to the printer 20, and the printer 20 receives the signal based on this signal. Then, a target transport amount determination pattern is printed (S103).
[0064]
The user or the like selects a patch having the highest image quality, that is, a patch in which white streaks and black streaks are least noticeable, from a plurality of printed patches. FIG. 13 is an explanatory diagram showing an example of a user interface window W2 for selecting a preferable patch from a plurality of printed patches. This window W2 is automatically displayed by the user interface display module 101 (FIG. 1) when the target transport amount determination pattern is printed. The window W2 is provided with a plurality of buttons B11 to B15 for selecting a preferable patch. When the user or the like clicks on any of these buttons B11 to B15 (S104), the number of pulses for carrying the target carry amount at the time of printing the corresponding patch is equal to the reference carry for performing printing by band feed. The quantity x is stored in a predetermined area of the EEPROM 58 (FIG. 3) of the printer 20 (S105).
[0065]
At this time, the correction value in the correction data table is converted based on the printing condition for printing the target transport amount determination pattern. That is, for example, when the target transport amount determination pattern is printed on plain paper in the normal mode, “0” is set to the correction value Δx when printing under the printing conditions. The correction value Δx at the time of printing under other printing conditions is obtained by correcting the relative pulse number based on the difference between the reference printing condition and the dot diameter printed under each printing condition in the correction data table. It is set as a value (S106). That is, when the target conveyance amount determination pattern is printed on fine paper in the normal mode, the correction value Δx for printing under these printing conditions is set to “0”, and the printing is performed on the plain paper and the normal mode. "+4" is used as the correction value .DELTA.x when printing, "+2" is used as the correction value .DELTA.x when printing in plain paper, and the fine mode, and "+4" is used as the correction value .DELTA.x when printing in the fine paper and fine mode. “−2” is set.
[0066]
=== Printing operation of band feed method ===
FIG. 14 is a flowchart illustrating an operation of performing band feed printing in the printer 20 that generates a correction data table using a target transport amount determination pattern printed on plain paper in the normal mode. That is, printing is executed based on the correction data table of FIG.
[0067]
The above-mentioned reference carry amount x is set in the EEPROM 58 of the printer 20 as the target carry amount of the carrying operation in the band feed printing (S201).
For example, the user sets fine paper on the printer 20, selects fine paper as the type of print paper from the computer 90, and selects normal mode as the print mode from the computer 90, and transmits the print data and print command to the printer 20.
In the printer 20, the system controller 54 reads necessary information from the data received from the reception buffer memory 50, and sends a control signal to each of the driving circuits 61, 62, and 63 based on the information (S202). .
When the print sheet is conveyed to a predetermined position by the control signal and print data enough to print when the carriage 28 performs one scan is stored in the image buffer 52 (S203), one scan is performed while scanning the carriage 28. The minute printing is executed (S204).
On the other hand, during this printing operation, the system controller 54 executes a calculation process for obtaining the target carry amount. The system controller 54 determines whether the type of printing paper is plain paper or fine paper based on the input printing conditions (S206), and determines whether the printing mode is the normal mode or the clean mode (S207, S208). . Based on these printing conditions, a corresponding correction value is selected from the correction data table (S209 to S212). In the above case, the correction value "-4" corresponding to the normal mode printing of fine paper is selected (S211). This correction value is added to the reference carry amount x stored in the EEPROM 58, and the target carry amount X is set (S213).
[0068]
When printing for one scan of the carriage 28 is performed, the printing paper is conveyed under the control of the paper feed motor 31 based on the target conveyance amount X obtained by the arithmetic processing (S214). Then, when print data obtained by the second scan of the carriage 28 exists in the image buffer 58 (S203), a printing operation is executed (S204). Thereafter, while print data is present in the image buffer 58 (S203), a transport operation (S214) in which the paper is transported based on the target transport amount X, and a print operation by one scan of the carriage 28 (S204). Is repeated, and when printing of the print data in the image buffer 58 is completed, the printing paper is discharged and the operation is terminated (S205).
[0069]
In the present embodiment, an example has been described in which the information for setting the correction value based on each print condition is print information indicating the type of print paper, the print mode, and the like input from the computer. The correction value may be set based on print data when scanning and printing. That is, since the drive waveform for ejecting ink differs according to the printing conditions, for example, the drive waveform in the first scan is an A type waveform, and the ink is ejected three times in a cycle for forming one dot. Is a printing condition for printing in normal mode on plain paper, a value obtained by adding a correction value suitable for this printing condition to the reference carry amount may be used as the target carry amount.
[0070]
In the above embodiment, the example in which the correction value of the correction data table is set to the number of pulses relative to the reference carry amount is shown, but the number of pulses of the target carry amount corresponding to each printing condition may be used.
[0071]
Further, in the present embodiment, an example has been described in which the printing conditions for changing the correction value are the type of printing paper and the printing mode, but the present invention is not limited to this. In addition, correction values are set according to each print mode, including matte paper, photographic exclusive paper, glossy paper, OHP film, etc. as print paper types, and even faster print modes as print modes. May be.
[0072]
=== Other Embodiments ===
The present invention is not limited to the above-described embodiment, but can be implemented in various modes without departing from the gist of the invention, and for example, the following modifications are possible.
[0073]
In the above-described embodiment, a color ink jet printer has been described. However, the present invention can be applied to a monochrome printer, and can also be applied to a printer other than an ink jet system. INDUSTRIAL APPLICABILITY The present invention is generally applicable to a printing apparatus that records an image on a print medium, and is also applicable to, for example, a facsimile apparatus and a copying machine. However, in a so-called ink jet printing apparatus that performs printing by ejecting ink from a print head, since high quality of a print result is particularly required, the above-described means for simplifying correction of a feed amount of a printing medium is used. Greater benefits.
[0074]
Further, in the above embodiment, as shown in FIG. 7, an example is shown in which a print head in which nozzle rows for ejecting inks of respective colors are arranged in the main scanning direction is used, but the present invention is not limited to this. For example, the present invention is applicable to a print head 36 having a two-row configuration including a black nozzle row and a color nozzle row.
[0075]
Further, in the above-described embodiment, the correction value is determined using one type of target transport amount determining pattern. However, the correction value may be determined using a plurality of types of target transport amount determining patterns. For example, a coarse correction value is determined using a first target transport amount determination pattern for coarse adjustment, and a final fine correction value is determined using a second target transport amount determination pattern for fine adjustment. You may make it.
[0076]
【The invention's effect】
According to the present invention, it is possible to realize a printing apparatus, a computer program, a computer system, and a printing method for printing by transporting a medium by a transport amount suitable for printing conditions to be printed.
[Brief description of the drawings]
FIG. 1 is a block diagram illustrating a configuration of a printing system as one embodiment of the present invention.
FIG. 2 is a schematic perspective view illustrating a main configuration of the color inkjet printer 20.
FIG. 3 is a block diagram showing an electrical configuration of the printer 20.
FIG. 4 is a perspective view illustrating a configuration of a sub-scanning drive mechanism.
FIG. 5 is an explanatory diagram schematically showing a configuration of a rotary encoder 46.
6A is a timing chart showing a waveform of an output signal of the rotary encoder 46 when the paper feed motor rotates forward, and FIG. 6B shows a waveform of an output signal of the rotary encoder 46 when the paper feed motor rotates reversely. It is a timing chart shown.
FIG. 7 is a diagram for explaining an arrangement of nozzles of the print head 36.
FIG. 8 is a diagram for explaining dots formed for each printing condition in band-feed printing.
9 is an example of a correction data table included in the printer 20. FIG.
FIG. 10 is an explanatory diagram illustrating an example of a target transport amount determination pattern.
FIG. 11 is a flowchart illustrating a procedure for determining a reference value of a sheet conveyance amount.
FIG. 12 is an explanatory diagram illustrating an example of a user interface window W1 for inputting a print instruction for a target transport amount determination pattern.
FIG. 13 is an explanatory diagram showing an example of a user interface window W2 for selecting a preferable patch from a plurality of printed patches.
FIG. 14 is a flowchart illustrating an operation of performing band-feed printing by the printer 20 that generates a correction data table based on the target transport amount determination pattern printed on plain paper in the normal mode.
[Explanation of symbols]
Reference Signs List 20 color inkjet printer 21 display means
22 paper stacker 24 paper feed roller
25 driven roller 26 platen
28 Carriage 30 Carriage motor
31 paper feed motor 32 traction belt
34 guide rail 36 print head
40 gear train 42 discharge roller
44 Giza rollers 46 Rotary encoder
47 code plate 48 photo sensor
48a light emitting diode 48b collimator lens
48c detection processing section 48d photodiode
48e signal processing circuit 48fA, 48fB comparator
50 Receive buffer memory 52 Image buffer
54 System controller 56 Main memory
58 EEPROM 61 Main scanning drive circuit
62 Sub-scanning drive circuit 63 Head drive circuit
90 Computer 91 Video Driver
92 Hard disk 95 Application program
96 Printer driver 97 Resolution conversion module
98 Color conversion module 99 Halftone module
100 rasterizer
101 User interface display module
102 Pattern supply module
LUT color conversion table
TPS target print amount determination pattern print signal
PD print data
P printing paper
W1, W2 User interface window

Claims (17)

An ink ejection section array in which ink ejection sections for ejecting ink are arranged in a row, and a transport mechanism for transporting a medium along the row direction of the ink ejection section row, and ejecting ink from the ink ejection section row. A printing operation for printing on the medium, and a transport operation for transporting the medium with the row length of the ink ejection unit row as a target transport amount, in a printing apparatus that alternately repeats
A printing apparatus, wherein the target transport amount is changed based on printing conditions for printing in the printing operation. The printing device according to claim 1,
The printing apparatus according to claim 1, wherein the printing condition is a condition that affects a shape of a dot formed on the medium by ink ejected from the ink ejection unit. The printing device according to claim 1, wherein
The printing apparatus according to claim 1, wherein the printing condition is a condition that affects a length of a dot formed on the medium in the column direction by ink ejected from the ink ejection unit. The printing device according to claim 1, wherein
The printing apparatus, wherein the printing condition is a type of the medium. The printing device according to any one of claims 1 to 4,
The printing apparatus, wherein the printing condition is image quality of an image to be printed. The printing device according to any one of claims 1 to 5,
The printing apparatus according to claim 1, wherein the printing condition is related to an amount of ink ejected from the ink ejecting unit to form one dot. The printing apparatus according to claim 1, wherein
The printing apparatus according to claim 1, wherein the change of the target transport amount is performed based on print information input together with a print command signal for performing the printing. The printing apparatus according to claim 1, wherein
The printing apparatus according to claim 1, wherein the change of the target transport amount is performed based on print data for performing the first printing operation on the medium. The printing device according to any one of claims 1 to 8,
In the target transport amount, a target transport amount corresponding to the printing condition is set in a target transport amount determining pattern printed under predetermined printing conditions, and the target transport amount is set to another printing condition based on the set target transport amount. A printing apparatus, wherein a corresponding target transport amount is set. The printing device according to any one of claims 1 to 9,
The target transport amount is based on a target transport amount corresponding to the printing condition in a target transport amount determination pattern printed under predetermined printing conditions, and the target transport amount corresponding to other printing conditions is the same as the reference. A printing apparatus, wherein a correction amount to be corrected is set for the transport amount when transported at a target transport amount. The printing apparatus according to any one of claims 1 to 10,
A printing apparatus, comprising: a data table in which the target transport amount is associated with a plurality of printing conditions. The printing device according to claim 9, wherein
The printing apparatus according to claim 1, wherein the target transport amount is extended when the dots to be formed are larger than the dot size formed by the printing conditions under which the target transport amount determining pattern is formed. The printing device according to claim 9 or 12,
The printing apparatus according to claim 1, wherein the target transport amount is reduced when the dots to be formed are smaller than a dot size formed by printing conditions in which the target transport amount determining pattern is formed. An ink ejection unit row in which ink ejection units that eject ink are arranged in a row, and a transport mechanism that transports the medium along the row direction of the ink ejection unit row,
In a printing apparatus, a printing operation of ejecting ink from the ink ejection unit row and printing on the medium, and a transport operation of transporting the medium with the row length of the ink ejection unit row as a target transport amount, are alternately repeated.
The target conveyance amount is input together with a print command signal for executing the printing, and based on the image quality of the image printed in the printing operation and the type of the medium,
The target transport amount is based on a target transport amount corresponding to the printing condition in a target transport amount determination pattern printed under predetermined printing conditions, and the target transport amount corresponding to other printing conditions is the same as the reference. The transport amount when transported at a target transport amount is set with a correction amount to be corrected,
A data table in which the target transport amount and a plurality of printing conditions are associated;
If the dots to be formed are larger than the dot size formed by the printing conditions for forming the target transport amount determination pattern, the target transport amount is extended,
The printing apparatus according to claim 1, wherein the target transport amount is reduced when the dots to be formed are smaller than a dot size formed by printing conditions in which the target transport amount determining pattern is formed. An ink ejection unit row in which ink ejection units that eject ink are arranged in a row, and a transport mechanism that transports the medium along the row direction of the ink ejection unit row,
A printing device that ejects ink from the ink ejection unit row to print on the medium, and a transport operation that transports the medium with the row length of the ink ejection unit row as a target transport amount, in a printing apparatus that alternately repeats,
A computer program for realizing a function of changing the target transport amount based on printing conditions for printing in the printing operation. A computer body, and an ink ejection unit row connected to the computer body and having ink ejection units for ejecting ink arranged in a row, and a transport mechanism for transporting a medium along the row direction of the ink ejection unit row. Prepare,
A printing apparatus that alternately repeats a printing operation of ejecting ink from the ink ejection unit row and printing on the medium, and a conveyance operation of conveying the medium with a row length of the ink ejection unit row as a target conveyance amount, In a computer system comprising
A computer system, wherein the target transport amount is changed based on printing conditions for printing in the printing operation. An ink ejection unit row in which ink ejection units that eject ink are arranged in a row, and a transport mechanism that transports the medium along the row direction of the ink ejection unit row,
A printing apparatus that alternately repeats a printing operation of ejecting ink from the ink ejection unit row and printing on the medium, and a conveyance operation of conveying the medium with the row length of the ink ejection unit row as a target conveyance amount. In the printing method for printing,
A printing method, comprising: changing the target transport amount based on printing conditions for printing in the printing operation.

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