JP7309455B2 - Image processing device - Google Patents

Description

The present invention relates to an image processing apparatus that generates ink drop data to be output to an inkjet printer based on document data.

2. Description of the Related Art Conventionally, inkjet printing apparatuses that perform printing by ejecting ink from an inkjet head onto a printing medium have been widely used.

Among such inkjet printing apparatuses, a multi-drop type inkjet printing apparatus has been proposed, which is capable of ejecting a plurality of ink droplets from one nozzle of an inkjet head to one pixel. In a multi-drop type inkjet printing apparatus, gradation printing is performed to express density by changing the number of ink droplets (drop number) ejected to one pixel.

Here, in the inkjet printer, a head gap is provided between the inkjet head and the print medium. The ink ejected from each nozzle of the inkjet head flies through this head gap and lands on the print medium. There is a problem that it turns into mist and adheres to the print medium, degrading the image quality of the printed image. This becomes more pronounced as the ink droplets are smaller.

In the multi-drop method, when a plurality of ink droplets are ejected onto one pixel, the ink droplets combine after ejection to form one ink droplet that flies. That is, the size of a flying ink droplet is proportional to the number of ink droplets ejected for one pixel. Therefore, in the multi-drop method, the smaller the number of ink droplets ejected for one pixel, the more likely the above-described misting of ink droplets occurs. When mist is emitted, it has a particularly large effect on barcodes composed of characters and thin lines, resulting in deterioration of image quality.

Therefore, in the multi-drop method, for example, when the head gap is large, a so-called one-dropless process is performed so that only one drop, which is the minimum number of drops per pixel, is not ejected. A method for reducing it has been proposed (see Patent Document 1, for example). As a result, it is possible to reduce the deterioration of print quality due to adhesion of mist and the contamination of the inside of the apparatus due to mist.

JP 2017-177638 A

However, when the 1-dropless process described above is performed, it is effective for characters and thin lines, but if there is a portion corresponding to the line width in the photographic image, the ejection of 1-drop is suppressed. Roughness is generated, and smooth gradation is not obtained, resulting in deterioration of image quality.

SUMMARY OF THE INVENTION It is an object of the present invention to provide an image processing apparatus capable of improving the gradation of photographic images while reducing mist generation.

The image processing apparatus of the present invention includes an object discrimination section that discriminates the attribute of an object included in document data, a drop data generation section that generates ink drop data based on the document data, and an ink drop data set in advance. a low-dropless processing unit that performs low-dropless processing for deleting ink drop data that is equal to or less than the number of drops, and the low-dropless processing unit performs low-dropless processing on ink drop data whose object attribute is character or line Do not perform low-dropless processing on ink drop data whose object attributes are photographs or drawings.

According to the image processing apparatus of the present invention, the attribute of the object included in the document data is discriminated, the low-dropless processing is performed on the ink drop data whose object attribute is character or line, and the object attribute is photograph or graphic. By not performing the low-dropless processing on the ink drop data, it is possible to improve the gradation of the photographic image while reducing the occurrence of mist.

In addition, if you do not apply low dropless processing to the ink drop data of the photo or figure, there is a possibility that the mist will cause misalignment of the impact, but in the case of the photo or figure, the impact misalignment of the mist will not be noticeable. no problem.

1 is a block diagram showing the configuration of an inkjet printing system using an image processing apparatus according to an embodiment of the present invention; A diagram showing a schematic configuration of the inkjet printing apparatus shown in FIG. Diagram for explaining an example of low-dropless processing FIG. 4 is a diagram for explaining generation and printing processing of first print data composed of text or line objects and second print data composed of photograph or drawing objects; Flowchart for explaining the flow of processing of the print data generation device Flowchart for explaining the flow of processing of the inkjet printing apparatus A diagram for explaining the case where part of the ink drop data area of a photograph or diagram exists at a position corresponding to the peripheral edge of the print medium. A diagram showing an example of a case in which an area of character or line ink drop data exists in the vicinity of an area of ink drop data in a photograph or figure. A diagram showing another example when an area of character or line ink drop data exists in the vicinity of an area of ink drop data in a photograph or figure A diagram showing an example of a case in which a character or line ink drop data area exists on the upstream side in the print medium transport direction with respect to a photograph or diagram ink drop data area. The character or line ink drop data area exists on the upstream side in the print medium transport direction with respect to the photo or graphic ink drop data area, and is part of the photo or graphic ink drop data area A diagram showing an example of a case where the area exists at the periphery of the print medium. first ink drop data of C, M and Y composed of both photo or drawing objects and character or line objects, and second ink drop data of K composed of character or line objects; , a diagram showing an example of the third ink drop data of K, which is composed of a photograph or drawing object

Hereinafter, an inkjet printing system using an embodiment of the image processing apparatus of the present invention will be described in detail with reference to the drawings. FIG. 1 is a schematic configuration diagram of an inkjet printing system according to this embodiment.

The inkjet printing system of this embodiment includes an inkjet printing device 1 and a print data generating device 2, as shown in FIG. In the inkjet printing system of the present embodiment, print data generated by the print data generation device 2 is input to the inkjet printer 1, and the inkjet printer 1 generates ink drop data from the input print data, Print processing is performed on a print medium based on the ink drop data. In this embodiment, the image processing apparatus of the present invention is composed of the object discrimination section 27 of the print data generation device 2 shown in FIG. It is configured.

FIG. 2 is a diagram showing a schematic configuration of the inkjet printing apparatus 1 of this embodiment. The inkjet printing apparatus 1 of the present embodiment is a multi-drop printing apparatus capable of double-sided printing. Note that the up, down, left, and right directions indicated by arrows in FIG. 2 are the up, down, left, and right directions of the inkjet printer 1 of the present embodiment. The front side of the paper surface of FIG. 2 is the front direction of the inkjet printer 1 of the present embodiment, and the back side of the paper surface is the rear direction.

As shown in FIG. 2, the inkjet printing apparatus 1 includes a side paper feeding unit 10, an internal paper feeding unit 20, a print processing unit 30, a paper discharging unit 40, a reversing unit 50, a control unit 60, and a display unit. A portion 70 and a transport portion 80 are provided.

The print processing unit 30, the internal paper feed unit 20, the transport unit 80, and the control unit 60 are housed and installed in a housing 100 made of metal, resin, or the like. Further, the side paper feeding section 10 , the paper discharging section 40 and the reversing section 50 are installed in a state in which a part thereof is housed inside the housing 100 and a part thereof protrudes outside the housing 100 .

The side paper feed unit 10 includes a paper feed table 11 on which the print medium P is placed, and a primary paper feed unit that feeds out only the uppermost print medium P from the paper feed table 11 and conveys it onto the paper feed transport path FR. 12, and a secondary paper feeder 14 for transporting the print medium P transported by the primary paper feeder 12 onto the circulation transport path CR.

The internal paper feed unit 20 includes a paper feed table 21a on which the print medium P is placed, and a primary paper feed unit that feeds out only the uppermost print medium P from the paper feed table 21a and conveys it onto the paper feed transport path FR. 22a, a paper feed table 21b on which the print medium P is placed, a primary paper feed unit 22b that feeds out only the uppermost print medium P from the paper feed table 21b and conveys it onto the paper feed transport path FR, and a printing A paper feed table 21c on which the medium P is placed, a primary paper feed section 22c that feeds out only the uppermost print medium P from the paper feed table 21c and conveys it onto the paper feed transport path FR, and the print medium P is placed. and a primary paper feed section 22d that feeds out only the uppermost print medium P from the paper feed table 21d and conveys it onto the paper feed transport path FR.

In this manner, the printing medium P is conveyed to the secondary paper feeding section 14 from the side paper feeding section 10 or the internal paper feeding section 20, and the printing medium P is further conveyed from the reversing section 50, which will be described later.

Therefore, in front of the secondary paper feeder 14 in the transport direction, there are a transport path for the print medium P fed from the internal paper feeder 20 and a print medium P transported from the reversing unit 50 and having one surface printed thereon. There is a confluence point where the transport route of Based on this confluence point, the route on the side of the paper feed mechanism is called the paper feed transport route FR, and the other routes are called the circulatory transport route CR.

The print processing section 30 includes a line head 31 and a head holder 32 . Each line head 31 has a plurality of inkjet heads, and ejects ink from the inkjet heads onto the print medium P conveyed by the conveying section 80 to perform printing processing. Each inkjet head of each line head 31 is installed in the head holder 32 .

The print processing unit 30 of this embodiment has four line heads 31, and the four line heads 31 are arranged along the transport path of the print medium P at predetermined intervals. The four line heads eject inks of different colors (eg, black, cyan, magenta and yellow).

Each line head 31 has two rows of heads in which three inkjet heads are arranged at equal intervals in a direction orthogonal to the transport direction of the print medium P, and the two rows of heads are arranged at a half pitch in the orthogonal direction. They are arranged and configured so that they are shifted by about a minute.

The transport section 80 includes a platen 81, a fan mechanism 82, a transport belt 83, and the like. The conveying unit 80 conveys the print medium P conveyed from the side paper feeding unit 10 while maintaining a constant speed in a state where the print medium P is attracted to the conveying belt 83 . After the print medium P is printed by the inkjet head, the transport unit 80 transports the printed print medium P to the paper discharge unit 40 .

The platen 81 is a plate member provided facing the bottom surface of the head holder 32 . The platen 81 is formed with a plurality of platen suction holes 81a. The platen suction hole 81a is a through hole, and is two-dimensionally formed in the transport direction of the print medium P and in a direction perpendicular to the transport direction.

A fan mechanism 82 is provided below the platen 81 . The fan mechanism 82 generates suction air in the platen suction holes 81 a of the platen 81 by rotating the fan to create a negative pressure in the space below the platen 81 .

The conveying belt 83 is an annular endless belt that is stretched over the platen 81 , driving rollers, driven rollers, and the like, and slides on the platen 81 . The transport belt 83 is made of a material such as rubber or resin that has plasticity and generates an appropriate frictional force with the print medium P. As shown in FIG. A plurality of belt suction holes (not shown) are formed in the conveying belt 83 . The belt suction hole is a through hole, and is two-dimensionally formed in the transport direction of the print medium P and in a direction orthogonal to the transport direction. Due to the suction air generated in the platen suction holes 81 a of the platen 81 described above, the suction air is also generated in the belt suction holes, and a suction force is generated, whereby the print medium P is attracted onto the conveying belt 83 .

Then, the print medium P transported by the transport unit 80 and printed by the print processing unit 30 is transported on the circulatory transport route CR by transport rollers or the like arranged on the circulatory transport route CR. A switching mechanism 49 is provided on the circulation path CR to switch between guiding the print medium P transported on the circulation path CR to the paper discharge section 40 and recirculating it on the circulation path CR. there is Specifically, the switching mechanism 49 switches between the transport path on the paper discharge unit 40 side and the transport path on the reversing unit 50 side.

The paper discharge unit 40 has a tray-shaped paper discharge table 45 protruding from the housing 100 of the inkjet printing apparatus 1 and a pair of paper discharge rollers 48 for discharging the print medium P onto the paper paper table 45 . Then, the print medium P guided by the switching mechanism 49 to the transport path on the side of the paper discharge section 40 is discharged onto the paper discharge table 45 by the paper discharge rollers 48 .

The reversing unit 50 has a reversing table 51 for reversing the print medium P, and transports the print medium P from the circulation conveying path CR to the reversing table 51, and transfers the printing medium P conveyed to the reversing table 51 onto the circulation conveying path CR. and a reversing roller 52 for returning to the original position.

The print medium P guided to the reversing section 50 by the switching mechanism 49 is transported from the circulating transport path CR to the reversing table 51 by the reversing rollers 52, and returned from the reversing table 51 to the circulating transport path CR, thereby being reversed. It is conveyed on the circulating conveying path CR in this state. Then, the print medium P whose front and back sides are reversed is transported again toward the print processing section 30 by a plurality of rollers such as the transport rollers 53 provided on the circulation transport path CR.

The control unit 60 controls the entire inkjet printer 1 . Further, the control unit 60 of this embodiment includes a drop data generation unit 61 and a low dropless processing unit 62, as shown in FIG.

The drop data generation unit 61 acquires print data output from the print data generation device 2, performs RIP processing on the print data to generate raster data, and generates ink drop data based on the raster data. Generate. The ink drop data is data used for ink ejection control of each inkjet head, and indicates the number of ink drops to be ejected from each nozzle of each inkjet head. Ink drop data is generated for each line head 31, that is, for each ink color.

The low-dropless processing unit 62 performs 1-dropless processing for deleting the ink drop data of the number of 1 drop from the ink drop data. In addition, in the present embodiment, the low dropless processing section 62 corresponds to the low dropless processing section of the present invention.

As a method of 1-dropless processing, for example, by simply setting the ink drop data of 1 drop included in the ink drop data to "0", the ink drop data of 1 drop may be deleted. For example, as shown in FIG. 3, if the ink drop data for a predetermined pixel is the ink drop data for one drop, the ink drop data for that one pixel is divided into "0" and "2". Ink drop data for one drop may be deleted by converting to ink drop data for 2 pixels. It should be noted that one square shown in FIG. 3 indicates one pixel, and the numerical value within one square indicates the number of drops of the ink drop data.

By converting the ink drop data of "1" into the ink drop data of two pixels of "0" and "2" as described above, it is possible to maintain substantially the same density as the ink drop data of one drop. can. Note that the one-dropless processing method is not limited to the method described above, and other known methods can be used.

In addition, the low dropless processing unit 62 of the present embodiment switches between the presence or absence of 1 dropless processing for the ink drop data of the object according to the attribute of the object included in the document data created by the print data generation device 2. . Note that switching between the presence and absence of 1-dropless processing according to the attribute of an object will be described in detail later.

The control unit 60 includes a CPU (Central Processing Unit), semiconductor memories such as a ROM (Read Only Memory) and a RAM (Random Access Memory), a storage such as a hard disk, and a communication I/F.

A print control program is installed in the semiconductor memory or hard disk of the control unit 60, and each unit of the inkjet printer 1 functions as the print control program is executed by the CPU.

The communication I/F of the control unit 60 communicates with the print data generation device 2, and the control unit 60 receives print data and the like output from the print data generation device 2 via the communication I/F.

The display unit 70 is composed of a touch panel having a liquid crystal display, and displays various setting input screens and accepts various setting inputs such as a print start instruction input.

Returning to FIG. 1, the print data generation device 2 is composed of a computer having a CPU and the like. The print data generation device 2 is installed with a document creation application 25 for creating document data and a printer driver 26 of the inkjet printer 1 . The printer driver 26 of this embodiment includes an object discrimination section 27 and a print data conversion section 28 .

The object determination unit 27 extracts an object included in the manuscript data created by the manuscript creation application 25 , determines the attribute of the object, and outputs the attribute to the print data conversion unit 28 . Attributes of objects in this embodiment include attributes of characters or lines and attributes of photographs or drawings. A known method can be used for extracting an object from manuscript data and determining the attributes of the object.

The print data conversion unit 28 converts the manuscript data output from the manuscript creation application 25 into print data in PDL (Page Description Language) format. Also, the print data conversion unit 28 of the present embodiment generates print data for each attribute based on the attribute of each object included in the document data.

Specifically, as shown in FIG. 4, an object having a character or line attribute included in the manuscript data is extracted, first print data composed of the extracted object is generated, and the first print data is generated from the extracted object. An object having the attribute of a photograph or a drawing is extracted, and second print data composed of the extracted object is generated. The print data conversion unit 28 then sequentially outputs the first print data and the second print data to the inkjet printer 1 .

The first print data and the second print data output from the print data conversion unit 28 are received by the drop data generation unit 61 as described above, and the first ink drop data are generated based on the first print data. is generated, and second ink drop data is generated based on the second print data.

Then, the low-dropless processing unit 62 of the present embodiment performs the above-described one-dropless processing on the first ink drop data generated from the first print data whose attribute is character or line, and the attribute is The second ink drop data generated from the second print data in which is a photograph or figure is not subjected to the one-dropless processing described above.

The low-dropless processing unit 62 of the present embodiment can suppress the above-described effect of mist by performing 1-dropless processing on the first ink drop data of characters or lines as described above. . On the other hand, the low dropless processing section 62 can maintain the gradation of the photograph or drawing by not performing the 1-dropless processing on the second ink drop data of the photograph or drawing. Thereby, the image quality of the printed image can be improved.

Next, the process flow of the inkjet printing system of this embodiment will be described with reference to the flow charts shown in FIGS. 5 and 6. FIG. FIG. 5 is a flow chart showing the flow of processing by the print data generation device 2, and FIG. 6 is a flow chart showing the flow of processing by the inkjet printer 1. As shown in FIG. First, the process flow of the print data generation device 2 will be described with reference to the flowchart shown in FIG.

First, document data is created by the document creation application 25 of the print data generation device 2, and the document data is accepted by the printer driver 26 (S10).

The document data received by the printer driver 26 is input to the object discrimination section 27, and the attribute of each object included in the document data is discriminated by the object discrimination section 27 (S12).

Then, the document data and the attribute of the object included in the document data are input to the print data conversion unit 28 . The print data conversion unit 28 extracts an object whose attribute is character or line based on the attribute of each object included in the manuscript data (S14, character/line), and converts a first character or line object composed of the character or line object. 1 print data is generated as 1 dropless process target data (S16).

In addition, the print data conversion unit 28 extracts an object whose attribute is a photograph or a drawing (S14, photograph/drawing), and converts the second print data composed of the object of the photograph or the drawing into one-dropless processing. It is generated as target data (S18).

The print data converter 28 then outputs the first print data and the second print data to the inkjet printer 1 (S20).

Next, the process flow of the inkjet printer 1 will be described with reference to the flowchart shown in FIG.

First, the first print data and the second print data output from the print data generation device 2 are acquired by the drop data generation section 61 (S30).

The drop data generator 61 generates first ink drop data based on the input first print data, generates second ink drop data based on the input second print data, and generates second ink drop data based on the input second print data. The first ink drop data and the second ink drop data are output to the low dropless processor 62 (S32).

Then, the low dropless processing unit 62 performs 1-dropless processing only on the first ink drop data whose attribute is character or line among the input first ink drop data and second ink drop data. (S34).

Next, the low dropless processing section 62 first outputs to the print processing section 30 the first ink drop data whose attribute is character or line among the first ink drop data and the second ink drop data.

Then, the control unit 60 controls the print processing unit 30 based on the first ink drop data, so that the printing medium P supplied from the side paper feeding unit 10 or the internal paper feeding unit 20 is printed for the first time. Print processing is performed (S36) (see the first print processing result shown in FIG. 4).

Next, after completing the printing process based on the first ink drop data, the control unit 60 transports the print medium P that has undergone the printing process twice through the circulation transport path CR (S38). That is, the control unit 60 conveys the print medium P twice through the circulation conveying path CR in the same manner as the conveyance control of the print medium P during double-sided printing, thereby performing the printing process based on the first ink drop data. The printed surface of the print medium P is conveyed to the conveying section 80 so that it becomes the print surface again.

Subsequently, the control section 60 controls the print processing section 30 based on the second ink drop data, and performs the second printing process on the print medium P conveyed by the conveying section 80 (S40).

In this manner, the printing process based on the first ink drop data is performed for the first time, and the printing process based on the second ink drop data is performed for the second time. The print image is printed (see the result of the second printing process shown in FIG. 4).

According to the ink jet printing system of the above-described embodiment, the attribute of the object included in the document data is discriminated, and 1-dropless processing is not performed on the ink drop data whose object attribute is a photograph or a figure. The gradation of the photographic image can be improved while reducing the occurrence of . In addition, since one-dropless processing is applied to ink drop data whose object attribute is character or line, character reproducibility can be improved.

Further, according to the inkjet printing system of the above-described embodiment, the print processing based on the first drop data of characters or lines subjected to the 1-dropless processing is performed for the first time, and the photograph or figure that has not been subjected to the 1-dropless processing is printed. Since the printing process based on the second drop data is performed for the second time, the ink mist generated by the printing process of the second drop data that has not undergone the 1-dropless process floats inside the device, Adherence to the medium P can be suppressed.

In the inkjet printing apparatus 1 of the above-described embodiment, the low-dropless processing unit 62 performs 1-dropless processing for deleting ink drop data of 1 drop number or less. The number of ink drops does not necessarily have to be 1 drop, and may be changed to, for example, 2 drops or less, or 3 drops or less. The number of ink drops of the ink drop data to be deleted may be configured to be changeable, for example, by the user setting and inputting the desired number of ink drops on the display section 70 . By making it possible to arbitrarily change the number of ink drops to be deleted in this way, ink mist can be further reduced, and the gradation of a photographic image can be appropriately adjusted.

Further, in the ink jet printing apparatus 1 of the above-described embodiment, 1-dropless processing is not applied to ink drop data whose attribute is a photograph or a drawing. When part or all of the ink drop data region RP exists at a position corresponding to the peripheral portion PP of the print medium P, the suction air generated in the belt suction holes of the conveying belt 88 causes , is susceptible to the above-mentioned mist. As described above, in the case of a photograph or a drawing, misalignment of mist landing is usually not noticeable.

Therefore, for the ink drop data of the photograph or the drawing existing in the region RP2 corresponding to the peripheral portion PP of the printing medium P, among the ink drop data regions RP of the photograph or the drawing shown in FIG. 1-dropless processing is applied only to the ink drop data of the photograph or figure existing in the region RP1 (the region closer to the center of the print medium P than the peripheral portion PP) other than the peripheral portion PP. may As a result, it is possible to suppress the influence of mist caused by the air sucked through the belt suction holes, and to improve the image quality.

It should be noted that the range of the peripheral portion PP can be arbitrarily set in advance according to the occurrence of wind and the occurrence of mist in the peripheral portion PP. As an example, the range of the peripheral portion PP may be set such that the distance d from the edge of the print medium P satisfies 0 cm<d≦2 cm.

In addition, the inkjet printing apparatus 1 of the above-described embodiment employs a suction transport method in which the print medium is transported by suction and adsorption to the transport belt 88. However, the present invention is not limited to this. It is also possible to employ an electrostatic transport method in which the substrate is transported by In the case of the electrostatic conveying method as well, wind is generated by the movement of the conveying belt itself, and the peripheral edge portion PP of the print medium P is easily affected by mist due to the wind.

Therefore, even in the case of the electrostatic transport method, the 1-dropless processing is performed on the ink drop data of the photograph or the figure existing in the region RP2 corresponding to the peripheral portion PP of the print medium P, and the region RP1 other than the peripheral portion PP is processed. Only the ink drop data of a photograph or a figure present in (an area closer to the center of the print medium P than the peripheral portion PP) may not be subjected to 1-dropless processing. That is, the present invention is applicable not only to a suction-conveyance type inkjet printing apparatus, but also to an electrostatic conveyance type inkjet printing apparatus.

In the above-described embodiment, the print data conversion unit 28 generates first print data composed of text or line objects and second print data composed of photograph or drawing objects. The drop data generation unit 61 generates the first ink drop data and the second ink drop data based on the two pieces of print data. Including both text or line objects and photograph or drawing objects when the presence or absence of 1-dropless processing can be switched partially for one piece of ink drop data instead of the entire ink drop data. Print data is generated, ink drop data for each color is generated from this print data, and in the ink drop data for each color, the presence or absence of 1-dropless processing is switched for each object based on the attribute of the object. good.

Then, based on the ink drop data of each color that has undergone the one-dropless process, a print image may be printed by one print process. As a result, the number of printing processes can be reduced, and production efficiency can be improved.

Further, in the ink jet printing apparatus 1 of the above-described embodiment, the ink drop data whose attribute is a photograph or a drawing is not subjected to 1-dropless processing. When printing is performed using ink drop data containing both photographic and graphic objects, as shown in FIG. When the ink drop data areas RL are adjacent to each other, if the 1-dropless process is not applied to the photo or graphic ink drop data, the mist generated when printing the photo or graphic ink drop data will be printed on the characters or The area RL of the line ink drop data is also affected, and the image quality of the character or line may be degraded.

Therefore, the 1-dropless process may be applied to the ink drop data of a photograph or drawing existing in the area RP4 near the area RL of the character or line ink drop data. As a result, it is possible to suppress the occurrence of ink mist in the area RP4 of the ink drop data of the photograph or figure, and to improve the image quality of characters or lines in the vicinity of the area RP4.

Note that the range of the region RP4 can be arbitrarily set in advance according to the state of occurrence of mist in the region of the ink drop data in the photograph or figure. As an example, the range of the region RP4 may be set such that the distance D from the character or line ink drop data region RL is 0 cm<D≦2 cm.

FIG. 8 shows an example in which the ink drop data region RP of a photograph or figure and the ink drop data region RL of characters or lines are in contact with each other. For example, as shown in FIG. 9, the ink drop data region RP of the photograph or figure and the ink drop data region RL of the character or line are separated from each other. One-dropless processing may be applied to the ink drop data of a photograph or figure existing in the region RP4 near the region RL of the ink drop data. Also in this case, the range of the region RP4 can be arbitrarily set in advance according to the state of occurrence of mist in the ink drop data region of the photograph or figure. As an example, the 1-dropless process may not be applied to the neighboring area RP4 where the distance D from the character or line ink drop data area RL is 0 cm<D≦2 cm.

Also, as described above, not only the positional relationship between the ink drop data of the photograph or figure and the ink drop data of characters or lines, but also the effect on the mist caused by the transporting wind generated by transporting the print medium P by the transport unit 80 is taken into consideration. , 1-dropless processing for ink drop data of photographs or drawings may be switched. That is, based on the positional relationship between the ink drop data of the photograph or figure and the ink drop data of characters or lines, and the transport direction of the print medium P, switching between the presence and absence of one-dropless processing for the ink drop data of the photograph or figure is performed. You can do it.

Specifically, for example, as shown in FIG. 10, an area RL1 of character or line ink drop data exists on the upstream side in the transport direction of the print medium P with respect to an area RP5 of photograph or figure ink drop data. In this case, low dropless processing is applied to a partial area RP7 of the ink drop data of the photograph or figure. As a result, it is possible to prevent the mist generated in the ink drop data region RP5 of the photograph or figure from being blown by the transport air and affecting the ink drop data region RL1 of the text or photograph.

On the other hand, if the character or line ink drop data region RL2 exists in the direction perpendicular to the transport direction of the print medium P with respect to the photograph or drawing ink drop data region RP8, One dropless processing may not be performed on a partial area RP10 of the ink drop data. In this case, the mist generated in the partial area RP10 of the ink drop data of the photograph or figure is unlikely to flow to the area RL2 of the ink drop data of characters or lines due to the transport wind, so the 1-dropless process is not performed. By doing so, it is possible to maintain the gradation.

The remaining area RP6 of the ink drop data area RP5 of the photograph or figure shown in FIG. 10 and the remaining area RP9 of the ink drop data area RP8 of the photograph or figure shown in FIG.

In the above description, the presence or absence of 1-dropless processing for the ink drop data of the photograph or figure is determined based on the positional relationship between the ink drop data of the photograph or figure and the ink drop data of characters or lines, and the direction of the transport wind. Although switching is performed, whether or not the 1-dropless process is performed may be switched depending on whether or not the periphery of the print medium P is affected by the air drawn by the conveying belt 83 .

Specifically, as shown in FIG. 11, an area RL of character or line ink drop data exists on the upstream side in the transport direction of the print medium P with respect to an area RP11 of photograph or diagram ink drop data. and when the partial area RP13 of the area RP11 of the ink drop data of the photograph or figure exists in the peripheral part PP of the print medium P, one drop is made for the partial area RP13 of the ink drop data of the photograph or figure. Apply less processing.

On the other hand, when the partial area RP13 of the area RP11 of the ink drop data in the photograph or figure does not exist in the peripheral edge portion PP of the print medium P (if it exists closer to the center of the print medium P than the peripheral edge portion PP), One dropless processing may not be applied to a partial area RP13 of the ink drop data of the photograph or figure. As a result, it is possible to limit the area of the photograph or figure to be subjected to 1-dropless processing, and maintain the gradation of the photograph or figure.

The remaining area RP12 of the ink drop data area RP11 in the photograph or diagram shown in FIG. 11 is also not subjected to the 1-dropless process.

Also, the range of the peripheral portion PP can be arbitrarily set in advance depending on the wind generation condition and the mist generation condition in the peripheral portion PP. As an example, the range of the peripheral portion PP may be set such that the distance d from the edge of the print medium P satisfies 0 cm<d≦2 cm.

Further, in the inkjet printing apparatus 1 of the above-described embodiment, the first ink drop data of characters or lines is subjected to one-dropless processing. , Y, and K) may not be subjected to the 1-dropless processing, and the 1-dropless processing may be performed only to the ink drop data of K, in which the mist tends to stand out on the printed image. Note that the order of colors in which the mist is more noticeable is the order of K, M, C, and Y (or K, C, M, and Y). Therefore, for example, the low dropless processing section 62 may perform one-dropless processing only on K and M or C ink drop data, or only on K, M and C ink drop data. 1-dropless processing may be performed.

Further, in the inkjet printing apparatus 1 of the above-described embodiment, the first ink drop data of characters or lines and the second ink drop data of photographs or lines are generated, and the printing process is performed twice. , and as described above, K is prone to conspicuous mist. Therefore, as shown in FIG. 12, the first ink drop data of C, M, and Y composed of both the photograph or figure object and the character or line object, and the character or line object are composed of the first ink drop data K second ink drop data and K third ink drop data composed of a photo or drawing object are generated, and only the second ink drop data is subjected to 1-dropless processing. The printing process may be performed three times based on the third ink drop data.

When printing is performed three times in this manner, the first printing process is based on the first ink drop data, the second printing process is based on the second ink drop data, and Preferably, the third print process is based on the third ink drop data. By performing printing in such order, the influence of the K mist can be further suppressed. That is, the third ink drop data in which mist of K is most likely to occur is set as the third printing process, the second ink drop data of the same K is set as the second printing process, and the first ink drop data not containing K is set. By setting the data to be the first printing process, it is possible to suppress the mist of K from floating in the apparatus due to the transportation of the printing medium P, and it is possible to further suppress the adhesion of the mist to the printing medium P. .

Further, as described above, the peripheral portion of the print medium P is likely to be affected by the mist caused by the air sucked by the conveying belt 83 . In addition, the K ink tends to have a conspicuous mist.

Therefore, it is determined whether or not a character or line object exists in the area corresponding to the peripheral edge of the print medium P. Among the color ink drop data, the ink drop data of K may be subjected to the low dropless processing, and the ink drop data of the other colors may not be subjected to the low dropless processing. In this case, it is desirable to perform the first printing process based on the low-dropless-processed ink drop data of K, and perform the second printing process based on the ink drop data of the other colors.

On the other hand, if there is no character or line object in the area corresponding to the periphery of the print medium P, the low-dropless processing is not applied to the ink drop data of all colors, and the print image of all colors is printed. It is preferable to print by one printing process.

In the above-described embodiment, the print data generation device 2 is provided with the object discrimination section of the present invention, and the ink jet printing device 1 is provided with the drop data generation section and the low dropless processing section of the present invention. Each unit may be provided on the print data generation device 2 side, or may be provided on the inkjet printer 1 side. Specifically, for example, the object discrimination section of the present invention is provided in the inkjet printer 1, and the object discrimination section discriminates the attribute of the object based on the print data output from the print data generation device 2. good too. Further, the drop data generation unit and the low dropless processing unit of the present invention are provided in the print data generation device 2, and the inkjet printing device 1 performs print processing based on the ink drop data output from the print data generation device 2. may be performed.

Regarding the image processing apparatus of the present invention, the following additional remarks are disclosed.
(Appendix)
In the image processing apparatus of the present invention, the low-dropless processing section can apply low-dropless processing to ink drop data whose object attribute is character or line.

In the image processing apparatus of the present invention, the low dropless processing section can be configured so that the preset number of drops can be changed.

Further, in the image processing apparatus of the present invention, the low-dropless processing unit performs the low-dropless processing when part or all of the ink drop data of the photograph or figure exists in an area corresponding to the periphery of the print medium on which the original data is printed. can apply low-dropless processing to some or all of the ink drop data.

Further, in the image processing apparatus of the present invention, the low-dropless processing section can apply low-dropless processing to the ink drop data of photographs or drawings that exist in the vicinity of the ink drop data of characters or lines. .

Further, in the image processing apparatus of the present invention, the low-dropless processing unit processes the image of the photograph or figure based on the positional relationship between the character or line ink drop data and the photograph or figure ink drop data and the transport direction of the print medium. Enables or disables low-dropless processing for ink drop data.

Further, in the image processing apparatus of the present invention, the drop data generation unit generates first ink drop data composed of an object whose attribute is text or line, and second ink drop data composed of an object whose attribute is a photograph or a drawing. The low dropless processing section can perform the low dropless processing only on the first drop data out of the first ink drop data and the second ink drop data. can. Then, the first drop data and the second drop data subjected to the low-dropless processing are output to a printing device capable of double-sided printing, and are based on the first drop data by the first double-sided printing conveyance of the printing device. A printing process is performed, and the printing process based on the second drop data can be performed by the second duplex printing transport of the printing device.

1 Inkjet printing device 2 Print data generation device 10 Side paper feeder 11 Paper feeder 12 Primary paper feeder 14 Secondary paper feeder 20 Internal paper feeder 21a-21d Paper feeder 22a-22d Primary paper feeder 25 Document creation application 26 Printer driver 27 Object discrimination unit 28 Print data conversion unit 30 Print processing unit 31 Line head 32 Head holder 40 Paper ejection unit 45 Paper ejection table 48 Paper ejection roller 49 Mechanism 50 Reversing unit 51 Reversing table 52 Reversing roller 53 Conveyance Roller 60 Control unit 61 Drop data generation unit 62 Low dropless processing unit 70 Display unit 80 Conveyance unit 81 Platen 81a Platen suction hole 82 Fan mechanism 83 Conveyor belt 88 Conveyor belt 100 Case CR Circulating conveying path FR Paper feeding conveying path P Printing Medium PP Periphery

Claims (6)

an object discriminating unit that discriminates whether an object included in document data is an attribute of characters or lines, or an attribute of a photograph or a diagram ;
a drop data generation unit that generates ink drop data based on the document data;
a low-dropless processing unit that performs low-dropless processing for deleting ink drop data having a predetermined number of drops or less from the ink drop data;
The low-dropless processing unit performs the low-dropless processing on the ink drop data of the object with the attribute of character or line, and performs the low dropless processing on the ink drop data of the object with the attribute of photo or drawing. Image processing equipment that does not apply . 2. The image processing apparatus according to claim 1, wherein said low dropless processing section is configured to be able to change said preset number of drops. When part or all of the ink drop data of the photograph or figure exists in an area corresponding to the periphery of the print medium on which the manuscript data is printed, the low dropless processing unit performs the part or the 3. An image processing apparatus according to claim 1, wherein said low dropless processing is applied to all ink drop data. an object discrimination unit that discriminates attributes of objects included in the manuscript data;
a drop data generation unit that generates ink drop data based on the document data;
a low-dropless processing unit that performs low-dropless processing for deleting ink drop data having a predetermined number of drops or less from the ink drop data;
The low-dropless processing unit does not perform the low-dropless processing on ink drop data whose object attribute is a photograph or a drawing, and performs the low dropless processing on ink drop data whose object attribute is text or line. An image processing apparatus for performing dropless processing, and for performing the low-dropless processing on the ink drop data of the photograph or figure existing in the vicinity of the ink drop data of the characters or lines. The low-dropless processing unit processes the photograph or drawing based on the positional relationship between the character or line ink drop data and the photograph or drawing ink drop data and the transport direction of a print medium on which the manuscript data is printed. 5. The image processing apparatus according to claim 4, wherein the presence/absence of the low dropless processing for the ink drop data is switched. an object discrimination unit that discriminates attributes of objects included in the manuscript data;
a drop data generation unit that generates ink drop data based on the document data;
a low-dropless processing unit that performs low-dropless processing for deleting ink drop data having a predetermined number of drops or less from the ink drop data;
The drop data generation unit generates first ink drop data composed of an object whose attribute is a character or line, and second ink drop data composed of an object whose attribute is a photograph or a drawing,
the low dropless processing unit performing the low dropless processing only on the first ink drop data out of the first ink drop data and the second ink drop data;
The first ink drop data subjected to the low dropless process and the second ink drop data are output to a printing device capable of double-sided printing, and the first ink drop data is transferred by the first double-sided printing conveyance of the printing device. An image processing apparatus in which print processing based on ink drop data is performed, and print processing based on the second ink drop data is performed by a second double-sided printing conveyance of the printing apparatus.