JP2002036528A - Ink jet recorder and printer driver - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ink jet recorder capable of obtaining a high quality image without generating permeation to a rear side, curl and cockling in perfecting printing. SOLUTION: The number of maximum dots per a unit region in single-side printing is differed from that in perfecting printing. The number of maximum dots per a unit region in the perfecting printing is lower than that in the single- side printing.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink jet recording apparatus, and more particularly to an ink jet recording apparatus and a printer driver capable of performing double-sided printing (double-sided recording).

[0002]

2. Description of the Related Art Printers, copiers, facsimile machines,
2. Description of the Related Art An ink jet recording apparatus used as an image recording apparatus such as a plotter or an image forming apparatus causes ink droplets ejected from a head to land on paper (meaning that ink droplets adhere, and is not limited to paper). Image recording, image show-through, paper curl, cockling (undulation), and the like are likely to occur.

[0003] In particular, in an ink jet recording apparatus,
When double-sided printing is performed, if image show-through occurs, the image quality of the front and back surfaces is significantly reduced, and if the paper is curled or cockled, the paper transportability is reduced. As a result, the image quality is reduced.

Therefore, in a conventional ink jet recording apparatus, as described in, for example, Japanese Patent Application Laid-Open No. 6-134982, the recording density during single-sided recording (synonymous with single-sided printing) and double-sided recording (synonymous with double-sided printing) The recording time at the time is variable, or the standby time after the front surface recording of the recording medium (synonymous with paper) and before the start of the back surface recording is made variable according to the type of the recording medium during double-sided recording (recording). Regarding the method for reducing the concentration, see also JP-A-5-32024).

[0005]

However, if the recording density during single-sided printing and the recording density during double-sided printing are made variable as described above, there is a problem that the image quality in double-sided printing deteriorates. In addition, providing the waiting time may lower the printing speed during double-sided printing, but has the problem that show-through, curl, and cockling cannot be eliminated.

The present invention has been made in view of the above points, and provides an ink jet recording apparatus capable of obtaining high image quality with less show-through, curl and cockling in double-sided printing. It is an object of the present invention to provide a printer driver capable of performing double-sided printing with high image quality without show-through, curl, and cockling.

[0007]

In order to solve the above-mentioned problems, an ink jet recording apparatus according to the present invention has a structure in which the maximum number of dots per unit area differs between single-sided printing and double-sided printing. Here, it is preferable that the maximum number of dots per unit area for double-sided printing is lower than the maximum number of dots per unit area for single-sided printing.

[0008] The ink jet recording apparatus according to the present invention comprises:
The maximum number of dots per unit area differs between single-sided printing and double-sided printing according to the print mode.
Here, the print mode preferably includes a speed priority mode in which the printing speed is prioritized over the image quality and an image quality priority mode in which the image quality is prioritized over the printing speed.

[0009] The ink jet recording apparatus according to the present invention comprises:
According to the print mode, the maximum number of dots per unit area is made different or the same for single-sided printing and double-sided printing. The print mode preferably includes a speed priority mode in which printing speed has priority over image quality and an image quality priority mode in which image quality has priority over printing speed.

In the ink jet recording apparatus according to the present invention, the maximum number of dots per unit area of the back side printing after the front side printing is the same as the maximum number of dots per unit area of the single side printing after the double side printing. It can be.

[0011] The ink jet recording apparatus according to the present invention comprises:
The maximum dot density differs between single-sided printing and double-sided printing. Here, it is preferable that the maximum dot density of double-sided printing is lower than the maximum dot density of single-sided printing.

[0012] The ink jet recording apparatus according to the present invention comprises:
The maximum dot density differs between single-sided printing and double-sided printing depending on the print mode. Here, the print mode preferably includes a speed priority mode in which the printing speed is prioritized over the image quality and an image quality priority mode in which the image quality is prioritized over the printing speed.

[0013] The ink jet recording apparatus according to the present invention comprises:
The maximum dot density differs between single-sided printing and double-sided printing or the same according to the print mode. Here, the print mode preferably includes a speed priority mode in which the printing speed is prioritized over the image quality and an image quality priority mode in which the image quality is prioritized over the printing speed.

In the ink jet recording apparatus according to the present invention, the maximum dot density of the back side printing after the front side printing and the maximum dot density of the single side printing can be the same in the duplex printing.

A printer driver according to the present invention is a printer driver for driving and controlling an ink jet recording apparatus capable of performing double-sided printing, and has means for making the maximum number of dots per unit area different between double-sided printing and single-sided printing. It is configured.

A printer driver according to the present invention is a printer driver for driving and controlling an ink jet recording apparatus capable of double-sided printing, and having a means for making the maximum dot density different between double-sided printing and single-sided printing. It is.

[0017]

Embodiments of the present invention will be described below with reference to the accompanying drawings. FIG. 1 is a perspective view showing an example of an ink jet recording apparatus according to the present invention, and FIG. 2 is a side view of a mechanism of the recording apparatus.

This ink jet recording apparatus includes a carriage movable in the main scanning direction inside the recording apparatus main body 1, a recording head including an ink jet head mounted on the carriage, an ink cartridge for supplying ink to the recording head, and the like. A paper feed cassette (or a paper feed tray) 4 serving as a paper feed unit capable of stacking a large number of sheets of paper 3 is inserted into and removed from the lower part of the apparatus main body 1 from below. A manual feed tray 5 is mounted on the front side so as to be freely opened, and the paper fed from the paper feed cassette 4 or the paper 3 set in the manual feed tray 5 is taken in. After a required image is recorded by the unit 2, the sheet is discharged to a sheet discharge tray 6 mounted on the rear side. Note that a scanning panel 8 is provided on the front surface.

The printing mechanism 2 holds a carriage 13 slidably in a main scanning direction (a direction perpendicular to the paper of FIG. 2) by a main guide rod 11 and a subordinate guide rod 12 which are laterally mounted on left and right side plates (not shown). On the lower surface side of the carriage 13, a recording head 14 composed of an ink jet head having nozzles for discharging ink droplets of yellow (Y), cyan (C), magenta (M), and black (Bk) is ejected. The ink tank (ink cartridge) 15 for supplying each color ink to the recording head 14 is exchangeably mounted on the upper side of the carriage 13.

As shown in FIG. 1, the carriage 13 is mounted on a timing belt 20 stretched between a drive pulley (drive pulley) 18 rotated by a main scanning motor 17 and a driven pulley (idler pulley) 19. The carriage 13 is moved in the main scanning direction by connecting and controlling the driving of the main scanning motor 17.

As the recording head 14, a plurality of heads for ejecting ink droplets of each color may be arranged side by side in the main scanning direction, or a single head having a nozzle for ejecting ink droplets of each color may be used. The used one may be used. In addition, the recording head 14 is configured to discharge ink droplets by pressurizing ink by displacing the diaphragm with an electromechanical transducer such as a piezoelectric element to change the volume of the liquid chamber, and disposed in the liquid chamber. A bubble that is generated by film boiling caused by the heated heating element and pressurizes ink in the liquid chamber to discharge ink droplets. An electrostatic force between the two is used by using a diaphragm that forms the wall surface of the liquid chamber and an electrode that faces the diaphragm. A device that displaces the diaphragm to eject ink droplets can be used.

On the other hand, the paper 3 is electrostatically attracted between the transport roller 21 and the transport driven roller 22 in order to transport the paper 3 in the sub-scanning direction with respect to the printing position (synonymous with the print position) by the recording head 14. The conveyor belt 23 for conveying the sheet is stretched and disposed. As shown in FIG. 1, a sub-scanning motor 24 is provided, and the rotation of the sub-scanning motor 24 is transmitted to the transport roller 21 via a gear train (not shown).
The transport roller 21 is rotated in the sub-scanning direction.

It is preferable that the transport roller 21 has a diameter such as 30 mm or more that does not separate the curvature and secures paper adhesion during double-sided printing. The transport belt 23 has a volume resistance of 10 mm or more. ⁹ Ωcm to 10 ¹² Ωc
It is preferable to use a medium resistor of m.

An image receiving member 26 is provided at a position facing the recording head 14 with the transport belt 23 interposed therebetween. Further, a tip roller 27 for defining a feed angle of the paper 3 is pressed against the transport roller 21 via a transport belt 23 and disposed.

On the other hand, in order to feed the paper 3 from the paper feed cassette 4 onto the conveyor belt 23, a paper feed roller 31 and a friction pad 32 which separate and feed the paper 3 one by one,
A guide member 34 is provided for guiding the fed sheet 3 to the intermediate roller 33 disposed in contact with the transport roller 21.

In order to feed the paper 3 from the manual tray 5 to the transport belt 23, a pickup roller 35 for picking up the paper 3 from the manual tray 5, a feed roller 36 for feeding the paper 3, and a feed roller 37 , Paper 3
And a guide member 38 that guides the roller to the intermediate roller 33.

A guide member 41 for guiding the paper 3 in order to discharge the paper 3 on which printing has been completed to the paper output tray 6.
And a paper discharge roller 42 for feeding the paper 3 to the paper discharge tray 6
And a paper discharge driven roller 43.

Further, the paper 3 which has passed the printing position by the recording head 4 is discharged in order to discharge the printed paper 3 once out of the apparatus main body 1 and feed it again to the conveyor belt 23 to perform double-sided printing. A guide member 45 for guiding the sheet 3 obliquely downward between the sheet discharge tray 6 and the sheet supply cassette 4 is provided, and near the entrance between the guide member 45 and the guide member 41 on the sheet discharge side, the sheet 3 is A first branch claw 46 for branching the discharge path is swingably provided.

In the vicinity of the terminal end of the guide member 45,
The paper 3 is discharged toward the upper surface of the paper feed cassette 4 outside the apparatus main body 1 (this position is a position where the paper waits for re-feeding, that is, a double-sided printing paper standby position). A switchback roller 47 and a switchback follower roller 48 for feeding the cartridge 3 into the apparatus main body 1 again are provided. The switchback roller 47 is rotated forward when the paper 3 having been printed on one side is conveyed in the discharge direction, reversely rotated when the paper 3 is re-fed, and discharged in the discharge direction of the paper 3 when the paper 3 is discharged. It is stopped at a predetermined timing to hold the rear end.

Further, on the upstream side of the switchback roller 47 and the switchback driven roller 48 in the sheet discharging direction,
A second branching claw 49 for switching the transport path of the sheet 3 between a discharge path to the outside of the apparatus main body 1 and a path for re-feeding the sheet 3 into the apparatus main body 1 is provided swingably. In order to feed the paper 3 fed into the apparatus main body 1 by the reverse rotation of the paper to the transport belt 23, a guide member 51 for guiding the paper 3, a double-sided relay roller 52 for transporting the paper 3 and a double-sided relay roller driven roller 53 and transport roller 2
1 and a transport roller driven roller 54 that feeds the sheet 3 to the intermediate roller 33 following the first roller 1.

Next, an outline of a control section of the ink jet recording apparatus will be described with reference to FIG. The control unit is a microcomputer (hereinafter, referred to as a “CPU”) that also functions as a unit that switches the maximum number of dots per unit area or a unit that switches the maximum dot density according to the present invention that controls the entire recording apparatus. ) 60, a ROM 61 storing necessary fixed information, a RAM 62 used as a working memory, an image memory 63 storing data obtained by processing image information, and a parallel input / output (PI).
O) port 64, input buffer 65, gate array (GA) or parallel input / output (PIO) port 66
And a head drive circuit 67 and drivers 68 and 69.

Here, in addition to image information from the host side, information indicating whether or not to perform double-sided printing,
Selection information from the printer driver according to the present invention, such as switching of the maximum number of dots or switching of the maximum dot density, information indicating the type of paper, various instruction information from the operation panel 8 shown in FIG. Signals from various sensors such as a home position sensor for detecting the reference position) are input, and necessary information is transmitted to the host and the operation panel through the PIO port 64.

The head drive circuit 67 operates based on various data and signals supplied through the PIO port 66 to actuator means (electromechanical conversion such as a piezoelectric element) corresponding to each nozzle of the recording head (inkjet head) 14. A driving waveform corresponding to image information is applied to an element, an electrothermal conversion element such as a heating resistor, a diaphragm, or a counter electrode. In addition, as a driving waveform, a rectangular pulse, a triangular waveform, and other shapes such as a sin (sine) waveform can be used.

Further, the driver 68 is connected to the PIO port 6
The main scanning motor 17 is controlled to drive the carriage 13 in the main scanning direction in accordance with the driving data given through the control unit 6, and the sub-scanning motor 25 is driven to control the conveyance rollers 21.
Is rotated in the paper transport direction (sub-scanning direction). The driver 69 controls the driving of a motor 71 for rotating the switchback roller 47 and solenoids 72 and 73 for swinging the first branch claw 46 and the second branch claw 49.

Next, the double-sided printing (double-sided printing) operation of this ink jet recording apparatus will be described with reference to FIGS. Referring to FIG. 4, when double-sided printing is instructed, as shown in FIG. 5, first branching pawl 46 is switched to double-sided printing side, second branching pawl 49 is switched to discharge side, and switchback roller 47 is turned forward. (Rotate in the direction to discharge the paper out of the device). By rotating the paper feed roller 31 to feed the paper 3 from the paper feed cassette 4, the paper 3 is fed to the transport belt 23 of the transport roller 21, is electrostatically attracted to the transport belt 23, and is subjected to sub-scanning. Transported in the direction
Here, the required image is printed on the surface of the paper 3 by driving the actuator means of the recording head 14 according to the recording image while moving the carriage 13 in the main scanning direction.

The paper 3 on which printing by the recording head 14 has been completed is guided by the guide member 45 between the switchback roller 47 and the switchback driven roller 48 because the first branch claw 46 is switched to the double-sided printing side. And is conveyed by the switchback roller 47 and the switchback driven roller 48 and discharged out of the apparatus main body 1 as shown in FIG. At this time, at the timing when the rear end of the sheet 3 is positioned between the switchback roller 47 and the switchback driven roller 48, the switchback roller 47
Is stopped, and the end of the sheet 3 is held as shown in FIG.

Next, as shown in FIG.
Is switched to the sheet discharging side, the second branching claw 49 is switched to the sheet re-feeding side, and then the switchback roller 47 is rotated in the reverse direction and the intermediate roller 51 is driven, so that the distance between the switchback roller 47 and the switchback driven roller 48 is changed. While guiding the paper 3 whose end is nipped by the guide member 51, the intermediate roller 51
To re-feed the sheet to the conveyor belt 23. In this case, the paper feed linear speed when re-feeding the paper 3 is set to be substantially the same as the linear speed of the transport belt 23. By this, paper 3
Can be fed while the surface, which is the printing surface, is not rubbed against the conveyor belt 23 while being in close contact with the conveyor belt 23.

While the paper 3 thus re-fed is conveyed by the conveyance belt 23, an image is printed on the back surface by the recording head 14, and the paper 3 on which the recording by the recording head 14 has been completed is first branched. The sheet is guided by the guide member 41 on the sheet discharge side through the claw 46, and the discharge roller 42 and the sheet discharge roller 43 are guided.
And is discharged to the discharge tray 6.

After printing on one side of the sheet as described above, an open system for temporarily discharging at least a part of the sheet to the outside of the apparatus main body allows only one recording head (recording means) to be used, and Inside can be simplified, and the ink drop drying time for double-sided printing can be gained,
The printing quality can be improved. In this case, by discharging the printing surface of the sheet to the outside of the apparatus main body, the printing surface to which the ink droplets adhere can be dried outside the apparatus main body, and the printing quality can be improved.

In addition, by reversing the paper in a switchback system for double-sided printing and re-feeding the paper, the configuration for performing double-sided printing is simplified, and the time required for drying the ink is increased. Can be performed. Furthermore, by discharging the paper below the printing position by the ink jet head for double-sided printing, it is possible to stably discharge the heavier paper with ink droplets attached to the double-sided printing standby position. it can. In this case, the double-sided printing standby position is located on the upper surface of a paper feeding unit such as a paper feeding tray or a paper feeding cassette for setting paper, so that it is not necessary to provide a separate tray for double-sided printing. Becomes easier. Further, the sheet is temporarily discharged to the sheet discharge tray 6, and the sheet discharge roller 42 can function as a switchback roller.

Next, an embodiment in which the present invention is applied to this ink jet recording apparatus will be described with reference to FIGS. First, “show-through”, which is the subject of the present invention, is a state in which the ink penetrates to the vicinity of the back surface of the paper and appears to bleed from the back surface. As a method of quantitatively showing show-through, there is a method of measuring back density. If the back density is high, the degree of show-through is poor.

As for "curl" and "cockling", the state in which the printing surface swells due to the adhesion of ink and the paper is curled is referred to as "curl", and the state in which the paper is uneven is referred to as "cockling". . As a method of quantitatively indicating the curl amount, there is a method of ranking the curl shape when the paper is placed on a flat surface and a method of indicating the rank or a method of measuring the floating amount at both ends of the paper, and the curl shape is cylindrical. The degree is worse as the distance is closer to, and the degree is worse as the floating amount is larger.
As for the amount of cockling, there is a method of measuring the amplitude of the irregularity by using a laser length measuring device. The longer the amplitude, the worse the degree.

Therefore, a different example of the first embodiment of the present invention will be described. In each example of this embodiment, the maximum number of dots per unit area differs between double-sided printing and backside printing. That is, with reference to FIG. 8, the first of the maximum dot number setting processing executed by the CPU 60 of the control unit.
To explain an example, it is determined whether printing is single-sided or double-sided, and the maximum number of dots per unit area is set to da for single-sided printing, and the maximum number of dots per unit area is set to db (db) for double-sided printing. <Da) is set.

The control section executes this maximum dot number setting process prior to the start of the printing operation. In the printing operation, the control section drives the head 14 with the set maximum dot number to execute printing.

FIG. 9 shows an example of the measurement results of the maximum dot number and the back density when printing is performed with the maximum dot number set to levels 1 to 8 as shown in Table 1. FIG. 10 shows the result of the curl amount, and FIG. 11 shows the results of the maximum dot number and the cockling amount. As can be seen from these figures, as the maximum number of dots decreases, the back density decreases (reduction of show-through), the amount of curl decreases, the amount of cockling decreases, and the image quality increases. Heading.

[0046]

[Table 1]

Therefore, as described above, by changing the maximum number of dots between single-sided printing and double-sided printing, it is possible to set the optimum maximum number of dots for each printing, and to reduce show-through, curl, and cockling. You can print high-quality images without any.

In the double-sided printing, when the surface to be printed first is the front surface and the surface to be printed later is the back surface, when the show-through, curl, and cockling occur after the front surface printing, printing on the back surface becomes difficult. There is. Therefore, by setting the maximum number of dots db for double-sided printing to be lower than the maximum number of dots da for single-sided printing, show-through in front side printing, curling, and good back side printing can be performed while preventing the occurrence of cockling. High quality printing becomes possible.

Next, referring to FIG.
A second example of the maximum dot number setting process executed by 0 will be described. In this process, it is determined whether the print mode is the speed priority mode or the image quality priority mode. In the speed priority mode, it is determined whether the printing is one-sided printing or two-sided printing. If the printing is one-sided, the maximum number of dots is set to da1, and if the printing is double-sided, the maximum number of dots is set to db1 (db1> da1). I do. On the other hand, in the image quality priority mode, it is determined whether the printing is one-sided printing or two-sided printing. If the printing is one-sided, the maximum number of dots is set to da2 (da2> db1). It is set to db2 (db2> da2).

Here, in general, when the printing speed is increased, the image quality is reduced, and when the image quality is improved, the printing speed is reduced. Is provided with at least two modes of “image quality priority mode” in which priority is given to speed, and any one of the modes can be selected. The print mode can be selected by the operation panel 8 or a printer driver of a host device that supplies data to the recording device.

FIG. 13 shows the evaluation results of the maximum number of dots and the printing speed satisfaction, and FIG. 14 shows the evaluation results of the maximum number of dots and the subjective satisfaction of the image quality. From these evaluation results,
It can be seen that if the maximum dot number = level 4 or less, the printing speed is satisfactory, and if the maximum dot number = 3 or more, the image quality is satisfactory. Therefore, in the above-described processing, the maximum number of dots da1 for speed-priority single-sided printing, the maximum number of dots db1 for speed-priority double-sided printing, the maximum number of dots da2 for image-quality priority single-sided printing, and the maximum number of dots da2 for image-quality priority double-sided printing The maximum number of dots db2 is, for example, da1 <db1 <da
It is preferable to set 2 <db2.

More specifically, the maximum number of dots da1 for single-sided printing is "level 1" for "speed priority", the maximum number of dots db1 for two-sided printing is "level 2", and the maximum number of dots for single-sided printing da2 is "level 5" for "image quality priority". , Maximum dot number d for double-sided printing
When b2 = level 8 was selected and actually evaluated, the speed was satisfied in “speed priority”, and the image quality was satisfied in “image quality priority”.

As described above, by switching the maximum number of dots to be printed per unit area for single-sided printing and double-sided printing in accordance with the printing mode, printing can be performed in accordance with the required printing speed and image quality.

Next, referring to FIG.
A third example of the maximum dot number setting process executed by 0 will be described. In this process, it is determined whether the print mode is the speed priority mode or the image quality priority mode. In the speed priority mode, the maximum number of dots for single-sided printing and double-sided printing is set to da1. On the other hand, in the image quality priority mode, it is determined whether printing is single-sided or double-sided, and the maximum number of dots is set to da2 (da2> da1) for single-sided printing, and the maximum number of dots is set for double-sided printing. db2 (db2>
da2).

That is, in the speed priority mode, by setting the maximum number of dots for single-sided printing and double-sided printing to be the same,
Speed is given top priority. Specifically, in “speed priority”, the maximum dot number da1 for one-sided printing and two-sided printing
= Set to level 1, and in "image quality priority", maximum dot number da2 for single-sided printing = level 5, maximum dot number d for double-sided printing
When b2 = level 8 was selected and actually evaluated, the speed was more satisfactory in "speed priority" than in the second example, and the image quality was more satisfactory in "image quality priority".

As described above, by switching the maximum number of dots to be printed per unit area between single-sided printing and double-sided printing according to the print mode, it is possible to switch between different or the same.
Printing can be performed according to the required printing speed and image quality.

Next, referring to FIG.
A fourth example of the maximum dot number setting process executed by 0 will be described. In this process, it is determined whether the print mode is the speed priority mode or the image quality priority mode. In the speed priority mode, it is determined whether the printing is one-sided printing or two-sided printing. If the printing is one-sided, the maximum number of dots is set to da1, and if the printing is double-sided, the maximum number of dots for the front-side printing is db1 (db1>).
In da1), the maximum number of dots for backside printing is set to da1, which is the same as for single-sided printing. On the other hand, in the image quality priority mode, it is determined whether the printing is one-sided printing or two-sided printing, and the maximum number of dots is set to da2 (da2> db1) for single-sided printing. The maximum number of dots is db
2 (db2> da2), the maximum number of dots for backside printing is set to da2, which is the same as for single-sided printing.

That is, by setting the maximum number of dots for double-sided printing and the maximum number of dots for single-sided printing to be the same, the speed can be increased while maintaining the image quality in double-sided printing. Specifically, in “speed priority”, the maximum number of dots da1 for backside printing of single-sided printing and double-sided printing is set to level 1, the maximum number of dots for front side printing of double-sided printing db1 is set to level 2, and “image quality” is set. Priority ”is the maximum number of dots d for backside printing of single-sided printing and double-sided printing
When a2 = level 5 and the maximum dot number db2 = level 8 of the front side printing of the two-sided printing were selected and actually evaluated, the speed in the two-sided printing could be increased, and the image quality was improved.

As described above, the printing speed and the image quality of the double-sided printing can be improved by making the maximum number of dots of the backside printing of the single-sided printing and the double-sided printing the same and making the maximum number of dots of the front-side printing of the double-sided printing different.

Next, a different example of the second embodiment of the present invention will be described. In each example of this embodiment, the maximum dot density differs between double-sided printing and backside printing. That is, referring to FIG.
In the first example of the maximum dot density setting process executed by the printer, it is determined whether the printing is single-sided printing or double-sided printing. If the printing is single-sided, the maximum dot density to be printed in the same area is set to qa. For example, the maximum dot density to be printed in the same area is set to qb (qb <qa).

The control unit executes this maximum dot density setting process prior to the start of the printing operation. In the printing operation, the control unit drives the energy generating means of the head 14 at the set maximum dot density to drop the ink droplet. Discharge.

FIG. 18 shows an example of the measurement results of the maximum dot density and the back density when printing is performed with the maximum dot density set at the resolution (dpi) from level 1 to level 8 as shown in Table 2. FIG. 19 shows the results of the maximum dot density and the curl amount.
FIG. 20 shows the results of the maximum dot density and the cockling amount. As you can see from these figures,
The lower the maximum dot density, the lower the back density (reduction of show-through), the smaller the amount of curl, the smaller the amount of cockling, and the higher the image quality.

[0063]

[Table 2]

Therefore, as described above, by changing the maximum dot density between single-sided printing and double-sided printing, it is possible to set the optimum maximum dot density for each printing, and to prevent show-through, curl, and cockling. You can print high-quality images without any.

In the double-sided printing, when the surface to be printed first is the front surface and the surface to be printed later is the back surface, when the show-through, curl, and cockling occur after the front surface printing, printing on the back surface becomes difficult. There is. Therefore, by setting the maximum dot density qb of double-sided printing to be lower than the maximum number of dots qa of single-sided printing, show-through on the front side printing, curl, good back side printing can be performed by preventing the occurrence of cockling, High quality printing becomes possible.

Next, referring to FIG.
A second example of the maximum dot density setting process executed by 0 will be described. In this process, it is determined whether the print mode is the speed priority mode or the image quality priority mode. In the speed priority mode, it is determined whether the printing is one-sided printing or two-sided printing. The maximum dot density is set to qa1 for single-sided printing, and the maximum dot density is set to qb1 (qb1> qa1) for double-sided printing.
Set to 1). On the other hand, in the image quality priority mode, it is determined whether single-sided printing or double-sided printing, and the maximum dot density is set to qa2 (qa2> qb1) for single-sided printing, and the maximum dot density is set for double-sided printing. qb2 (qb2
> Qa2).

Here, in general, when the printing speed is increased, the image quality is reduced, and when the image quality is improved, the printing speed is decreased. Is provided with at least two modes of “image quality priority mode” in which priority is given to speed, and any one of the modes can be selected. In this case, generally, if the dot density is high, printing takes time (the printing speed is slow), and if the dot density is low, the image has a low resolution (image quality is deteriorated). The print mode can be selected by the operation panel 8 or a printer driver of a host device that supplies data to the recording device.

FIG. 22 shows the evaluation results of the maximum dot density and the printing speed satisfaction, and FIG. 23 shows the evaluation results of the maximum dot density and the subjective satisfaction of the image quality. From these evaluation results, it can be seen that if the maximum dot density = level 4 or less, the printing speed is satisfactory, and if the maximum dot density = level 3 or more, the image quality is satisfactory. Therefore, in the above-described processing, the maximum dot density qa at the time of the speed priority single-sided printing is used.
1, maximum dot density qb1 for speed priority double-sided printing,
The maximum dot density qa2 in the image quality priority single-sided printing and the maximum dot density qb2 in the image quality priority double-sided printing are preferably set to, for example, qa1 <qb1 <qa2 <qb2.

Specifically, the maximum dot density qa1 for single-sided printing is "level 1" for "speed priority", the maximum dot density qb1 for level 2 is "2" for "double-sided printing", and the maximum dot density qa2 for level 1 is "5" for "image quality priority". When the maximum dot density qb2 of two-sided printing was selected and level 8 was actually evaluated, the speed was satisfied in “speed priority” and the image quality was satisfied in “image quality priority”.

As described above, by switching the maximum dot density used for printing between single-sided printing and double-sided printing according to the print mode, printing can be performed in accordance with the required printing speed and image quality.

Next, referring to FIG.
A third example of the maximum dot density setting process executed by 0 will be described. In this process, it is determined whether the print mode is the speed priority mode or the image quality priority mode. In the speed priority mode, the maximum dot density for single-sided printing and double-sided printing is set to qa1. On the other hand, in the image quality priority mode, it is determined whether the printing is single-sided printing or double-sided printing. If the printing is single-sided, the maximum dot density is set to qa2 (qa2> qa1).
And the maximum dot density is qb2 for double-sided printing.
(Qb2> qa2) is set.

That is, in the speed priority mode, the highest priority is given to the speed by setting the same maximum dot density for single-sided printing and double-sided printing. In particular,
For "speed priority", the maximum dot density qa1 for single-sided printing and double-sided printing is set to level 1, and for "image quality priority", the maximum dot density qa2 for single-sided printing = level 5, and the maximum dot density qb2 for double-sided printing = level 8 is selected. As a result of actual evaluation, "speed priority" satisfied the speed more than the second example, and "image quality priority" satisfied the image quality.

As described above, by switching whether the maximum dot density for printing in the same area of single-sided printing and double-sided printing is made different or the same according to the print mode, it is possible to meet the required printing speed and image quality. Printing can be performed.

Next, referring to FIG.
A fourth example of the maximum dot density setting process executed by 0 will be described. In this process, it is determined whether the print mode is the speed priority mode or the image quality priority mode. In the speed priority mode, it is determined whether the printing is one-sided printing or two-sided printing. If the printing is one-sided printing, the maximum dot density is set to qa1.
In b1> qa1), the maximum dot density of the back side printing is set to qa1 which is the same as the one side printing. On the other hand, in the image quality priority mode, it is determined whether the printing is one-sided printing or two-sided printing.
1), in the case of double-sided printing, the maximum dot density for front side printing is set to qb2 (qb2> qa2), and the maximum dot density for back side printing is set to qb1 which is the same as for single-sided printing.

That is, by setting the maximum dot density for backside printing and the maximum dot density for single-sided printing in duplex printing to be the same, the speed can be increased while maintaining the image quality in duplex printing. Specifically, "speed priority"
In the single-sided printing and the double-sided printing, the maximum dot density qa1 of the back side printing is set to level 1 and in the double-sided printing, the maximum dot density qb1 of the front side printing is set to level 2; When the maximum dot density qa2 of the back side printing was selected to be level 5 and the maximum dot density qb2 of the front side printing of the two sided printing was selected to be level 8 and actually evaluated, the speed in the both side printing could be increased, and the image quality could be improved. Also improved.

As described above, the printing speed and the image quality of the double-sided printing can be improved by making the maximum dot densities of the single-sided printing and the double-sided printing the same on the back side printing and making the maximum dot density of only the front-side printing of the double-sided printing different.

Next, an embodiment of the printer driver according to the present invention will be described. This printer driver is a host device that supplies data to an ink jet recording apparatus via a printer cable or a line (including a general subscriber telephone network, a dedicated line, a local area network, a LAN, or the like), or a copy, facsimile, or printer. In the case of a multifunction peripheral including the above, the multifunction peripheral is stored and held in the storage means of the multifunction peripheral itself, and is installed in a host device or a multifunction peripheral via a storage medium or a network.

Therefore, the printer driver has means (program) for executing any one or more of the maximum dot number setting processes 1 to 4 for making the maximum dot number different between single-sided printing and double-sided printing. Can be installed in the inkjet recording apparatus, and high-quality image printing with reduced show-through, curl, and cockling can be performed on the inkjet recording apparatus.

The printer driver has a means (program) for executing one or more of the nozzle number setting processes 1 to 4 for making the maximum dot density different between single-sided printing and double-sided printing. It can be installed in an inkjet recording apparatus, and can execute high-quality image printing with reduced show-through, curl, and cockling on the inkjet recording apparatus.

Further, the ink jet recording apparatus may have a plurality of setting processes, and the printer driver may have means for designating any one of the plurality of setting processes of the ink jet recording device. By doing so, printing can be performed more easily with the image quality and printing speed desired by the user.

[0081]

As described above, according to the ink jet recording apparatus of the present invention, the maximum number of dots per unit area is different between single-sided printing and double-sided printing. Double-sided printing can be performed. Here, by setting the maximum number of dots for double-sided printing to be lower than the maximum number of dots for single-sided printing, a high-quality image free from bleeding, curling, and cockling can be printed.

According to the ink jet recording apparatus of the present invention, the maximum number of dots per unit area differs between single-sided printing and double-sided printing depending on the printing mode.
The printing speed can be improved and high image quality without bleeding, curling and cockling can be achieved. Here, by including the speed priority mode and the image quality priority mode in the print mode, the image quality in the print speed priority and the image quality priority mode can be improved.

According to the ink jet recording apparatus of the present invention, the maximum number of dots per unit area for single-sided printing and double-sided printing is made different or the same according to the printing mode, so that the printing speed is improved. And high image quality without bleeding, curling and cockling. Here, by including the speed priority mode and the image quality priority mode in the print mode, the speed and image quality in the print speed priority and image quality priority modes can be improved.

Here, the printing speed can be improved by adopting a configuration in which the maximum number of dots for back side printing after the front side printing and the maximum number of dots for single side printing are the same during double side printing.

According to the ink jet recording apparatus of the present invention, since the maximum dot density is different between single-sided printing and double-sided printing, single-sided printing and double-sided printing can be performed with high image quality. Here, by setting the maximum number of dots for double-sided printing to be lower than the maximum number of dots for single-sided printing, a high-quality image free from bleeding, curling, and cockling can be printed.

According to the ink jet recording apparatus of the present invention, the maximum dot density is different between single-sided printing and double-sided printing depending on the printing mode, so that the printing speed is improved and there is no blur, curl or cockling. High image quality can be achieved. Here, by including the speed priority mode and the image quality priority mode in the print mode, the image quality in the print speed priority and the image quality priority mode can be improved.

According to the ink jet recording apparatus of the present invention, the maximum dot density is made different or the same for single-sided printing and double-sided printing depending on the printing mode. And high image quality without cockling. Here, by including the speed priority mode and the image quality priority mode in the print mode, the speed and image quality in the print speed priority and image quality priority modes can be improved.

Here, by adopting a configuration in which the maximum dot density of the back side printing after the front side printing and the maximum dot density of the single side printing in the both side printing are the same, the printing speed can be improved.

According to the printer driver of the present invention,
Since a configuration is provided in which means for making the maximum number of dots per unit area different between double-sided printing and single-sided printing is used, the image quality of double-sided printing in an inkjet recording apparatus capable of double-sided printing can be improved.

According to the printer driver of the present invention,
Since the configuration is provided with means for making the maximum dot density different between double-sided printing and single-sided printing, the image quality of double-sided printing in an inkjet recording apparatus capable of double-sided printing can be improved.

[Brief description of the drawings]

FIG. 1 is an explanatory perspective view of an ink jet recording apparatus according to the present invention.

FIG. 2 is an explanatory side view of a mechanism of the recording apparatus.

FIG. 3 is a block diagram showing an outline of a control unit of the recording apparatus.

FIG. 4 is a flowchart for explaining a double-sided printing operation of the recording apparatus.

FIG. 5 is an enlarged explanatory view of a main part used for explaining the operation.

FIG. 6 is an enlarged explanatory view of a main part used for explaining the operation.

FIG. 7 is an enlarged explanatory view of a main part used for explaining the operation.

FIG. 8 is a flowchart illustrating a first example of a maximum dot number setting process according to the first embodiment of the present invention.

FIG. 9 is an explanatory diagram illustrating measurement results of the maximum number of dots and the back density.

FIG. 10 is an explanatory diagram illustrating the results of the maximum number of dots and the amount of curl.

FIG. 11 is an explanatory diagram illustrating results of a maximum dot number and a cockling amount.

FIG. 12 is a flowchart illustrating a second example of the maximum dot number setting process according to the first embodiment of the present invention.

FIG. 13 is an explanatory diagram illustrating the relationship between the maximum number of dots and the printing speed.

FIG. 14 is an explanatory diagram illustrating the relationship between the maximum number of dots and image quality.

FIG. 15 is a flowchart illustrating a third example of the maximum dot number setting process according to the first embodiment of the present invention.

FIG. 16 is a flowchart illustrating a fourth example of a maximum dot number setting process according to the first embodiment of the present invention.

FIG. 17 is a flowchart illustrating a first example of a maximum dot density setting process according to the second embodiment of the present invention.

FIG. 18 is an explanatory diagram illustrating measurement results of a maximum dot density and a back density.

FIG. 19 is an explanatory diagram illustrating results of a maximum dot density and a curl amount.

FIG. 20 is an explanatory diagram illustrating results of a maximum dot density and a cockling amount.

FIG. 21 is a flowchart illustrating a second example of a maximum dot density setting process according to the second embodiment of the present invention.

FIG. 22 is an explanatory diagram illustrating a relationship between a maximum dot density and a printing speed.

FIG. 23 is an explanatory diagram illustrating the relationship between the maximum dot density and image quality.

FIG. 24 is a flowchart illustrating a third example of the maximum dot density setting process according to the second embodiment of the present invention.

FIG. 25 is a flowchart illustrating a fourth example of a maximum dot density setting process according to the second embodiment of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Device main body, 2 ... Printing mechanism part, 3 ... Paper, 4 ... Paper feed cassette, 6 ... Discharge tray, 13 ... Carriage, 14 ... Head, 21 ... Conveying roller, 23 ... Conveying belt, 42 ... Discharge Rollers, 46: first branch claws, 47: switchback rollers, 49: second branch claws.

Claims (14)

[Claims] 1. An ink jet recording apparatus capable of double-sided printing, wherein the maximum number of dots per unit area differs between single-sided printing and double-sided printing. 2. The ink jet recording apparatus according to claim 1, wherein the maximum number of dots per unit area for double-sided printing is lower than the maximum number of dots per unit area for single-sided printing. 3. An ink-jet recording apparatus capable of double-sided printing, wherein the maximum number of dots per unit area differs between single-sided printing and double-sided printing depending on the printing mode. 4. An ink-jet recording apparatus capable of performing double-sided printing, wherein the maximum number of dots per unit area in single-sided printing and double-sided printing is made different or the same according to a printing mode. 5. The ink jet recording apparatus according to claim 3, wherein the print mode includes a speed priority mode in which printing speed has priority over image quality and an image quality priority mode in which image quality has priority over printing speed. Inkjet recording device. 6. The maximum number of dots per unit area for backside printing after front side printing and the maximum number of dots per unit area for single sided printing in the ink jet recording apparatus according to claim 1. An ink jet recording apparatus having the same number. 7. An ink jet recording apparatus capable of double-sided printing, wherein the maximum dot density is different between single-sided printing and double-sided printing. 8. The ink jet recording apparatus according to claim 6, wherein the maximum dot density for double-sided printing is lower than the maximum dot density for single-sided printing. 9. An ink-jet recording apparatus capable of double-sided printing, wherein the maximum dot density differs between single-sided printing and double-sided printing depending on the print mode. 10. An ink-jet recording apparatus capable of performing double-sided printing, wherein the maximum dot density differs between single-sided printing and double-sided printing or the same according to a printing mode. 11. The ink jet recording apparatus according to claim 9, wherein the print mode includes a speed priority mode in which printing speed has priority over image quality, and an image quality priority mode in which image quality has priority over printing speed. Inkjet recording device. 12. The ink jet recording apparatus according to claim 7, wherein the maximum dot density of the back side printing after the front side printing is the same as the maximum dot density of the single side printing in the both side printing. Characteristic inkjet recording device. 13. A printer driver for driving and controlling an ink jet recording apparatus capable of performing double-sided printing,
A printer driver comprising means for making the maximum number of dots per unit area different between double-sided printing and single-sided printing. 14. A printer driver for driving and controlling an ink jet recording apparatus capable of performing double-sided printing,
A printer driver having means for making the maximum dot density different between double-sided printing and single-sided printing.