JP2011088283A - Printer and printing method - Google Patents

Abstract

An object of the present invention is to improve the image quality of a printing result when printing is performed by irradiating a photocurable ink adhered to a printing paper by irradiating ultraviolet light.
The print surface to be printed is divided based on the input image data ID input to set two or more areas, and the amount of ink attached to each of the areas set based on the input image data ID And the curing energy necessary for curing the ink attached to each area based on the calculated ink amount, and the ink is attached to the printing paper P based on the input image data ID, and for each area. The curing unit 130 for irradiating the printing paper P with ultraviolet light and curing it is controlled so that the ultraviolet light is irradiated with the calculated curing energy.
[Selection] Figure 3

Description

  The present invention relates to a printing apparatus and a printing method, and more particularly to a printing apparatus and a printing method for performing printing using a photocurable color material.

A photocurable ink may be used when printing with a inkjet printer that requires quick drying or printing on a non-absorbing material that hardly absorbs ink.
In an ink jet recording apparatus that performs printing using such a photocurable ink, even when irradiating ultraviolet light for curing the ink attached to the print medium, even one dot is drawn in the ultraviolet light irradiation area. Patent Document 1 discloses that the area is irradiated with ultraviolet light, and if no dot is drawn in the irradiation area, the area is not irradiated with ultraviolet light. ing. According to the technique of Patent Document 1, it is possible to reduce power consumption required for ultraviolet light irradiation and extend the life of the ultraviolet light irradiation unit.

JP 2006-297608 A

However, in the above-described technique of Patent Document 1, power consumption and component life are taken into consideration, but printing image quality is not taken into consideration.
The present invention has been made in view of the above-described problems, and relates to a printing apparatus and a printing method for performing printing by curing a photocurable coloring material attached to a printing medium by irradiating predetermined active light. The object is to improve the image quality of the printed result.

  In order to solve the above-described problems, in the printing apparatus according to the present invention, in a printing apparatus that performs printing using a photocurable color material, the color adhered to the printing medium while moving relative to the printing medium. When the material is cured by irradiating light using a curing unit, the print medium is irradiated with light at an appropriate irradiation amount according to the color material attached to each region of the print surface of the print medium. It is configured. The curing unit is a unit for irradiating the photocurable colorant with active energy and curing it.

  In the above configuration, when the image data acquisition unit acquires image data, the region setting unit divides the print surface to be printed based on the image data and sets two or more regions. This division method may be a closed area where each area is combined into one, but a combination of a plurality of closed areas selected in a fragmentary manner is regarded as one area set by the area setting unit. It doesn't matter. For example, when printing is performed by scanning the print head, even if the range printed in one scan corresponds to a flying raster, the plurality of flying rasters can be regarded as one area, When printing a plurality of skipped pixels constituting one raster by one scan of the print head, a combination of a plurality of skipped pixels printed in one scan pass in the raster is defined as one region. Can be considered.

  The color material amount calculation unit calculates the color material amount to be attached based on the image data for each region set by the region setting unit. The amount of color material attached to each of the regions based on the image data is uniquely determined according to various print settings. For example, each region is obtained by converting image data into color material amount data. It is possible to calculate the amount of the color material attached to each region by adding the color material amount data of each pixel corresponding to.

  When the amount of color material attached to each region is calculated, the energy calculation unit calculates the curing energy necessary for curing the color material attached to each of the regions based on the amount of color material. The curing energy may be calculated in units of energy such as joules or calories, but may be calculated by the amount of light irradiation, or specified by the illuminance of light if the scanning speed of the print head described above is constant. Is also possible. Conversely, if the illuminance of light during scanning of the print head is not changed, it can be specified by the scanning speed of the print head. Further, if the moving speed of the print head and the illuminance of light can be changed, it is also possible to specify them in combination.

  As described above, when the curing energy necessary for curing the color material attached to each area is determined, the printing unit attaches the color material to the print medium based on the image data. The curing unit is controlled so that the curing energy calculated for each region is given to each of the regions. By performing printing in this way, curing energy is irradiated without excess or deficiency, and the print medium is altered (such as yellowing of the printing paper) due to excessive irradiation of light, or coloring material due to insufficient irradiation of light. It is possible to prevent such a problem that does not cure sufficiently. Therefore, the image quality of the print result is improved.

  As a selective aspect of the present invention, the printing unit irradiates the print medium with the illuminance of the light different for each region while moving the curing unit at a constant relative speed with respect to the print medium. The curing unit may be controlled so that the curing energy calculated for each region by the energy calculation unit is irradiated to each region. By comprising in this way, a hardening unit should just be moved with a fixed moving speed, and the conveyance apparatus of a hardening unit can be simplified.

As a selective aspect of the present invention, a sub scan in which the print medium is moved relative to the print head in a sub scan direction orthogonal to the main scan direction while performing a main scan in which the print head is reciprocated in the main scan direction. The color material is attached to the print medium while scanning, and the region setting unit sets a group of portions to which the color material is attached in each pass of the main scan of the print head as one region. It may be configured.
By configuring in this way, a printing device that simultaneously prints a flying raster with a print head that has multiple ejection holes that eject the same color material from the print head toward the print medium, and a single raster are configured. Even in a printing apparatus that distributes and prints a plurality of dots to a plurality of scanning passes, the curing unit can also be transported by a transport device that reciprocates the print head in the main scanning direction. That is, since the print head and the curing unit are integrally conveyed, it is possible to irradiate and cure the color material immediately after being attached to the print medium from the print head, which contributes to improvement in image quality. . Further, since the print head and the curing unit are integrated, the apparatus can be made compact and the cost can be reduced.

  As a selective aspect of the present invention, a sub scan in which the print medium is moved relative to the print head in a sub scan direction orthogonal to the main scan direction while performing a main scan in which the print head is reciprocated in the main scan direction. The color material may be attached to the print medium while scanning, and the area setting unit may set each of the areas as one closed area. With this configuration, even in a printing apparatus that distributes and prints the same raster to a plurality of scanning passes, it is possible to calculate the curing energy of light to be irradiated for each scanning pass.

  As a selective aspect of the present invention, the printing unit can perform printing in which a plurality of types of color materials are attached to the print medium, and the energy calculation unit calculates the color calculated by the color material amount calculation unit. It is good also as a structure which calculates the curing energy of the coloring material adhering to each of the said area | region by multiplying the curing energy per unit amount weighted with the curing characteristic with respect to the said light of each coloring material with respect to the amount of materials. If comprised in this way, even if it has a different hardening characteristic for every kind of color material, light comes to be able to be irradiated with an appropriate irradiation amount.

  The above-described printing apparatus includes various modes such as being implemented in a state of being incorporated in another device or being implemented together with another method. The present invention also provides a printing system including the above-described printing apparatus, a printing method and a printing control method having steps corresponding to the configuration of the above-described apparatus, a printing program for causing a computer to realize functions corresponding to the above-described apparatus configuration, and the program It can also be realized as a computer-readable recording medium on which is recorded. The inventions of the printing system, the printing method, the printing control method, the printing program, and the medium on which the program is recorded also have the operations and effects described above. Of course, the configurations described in claims 2 to 5 are also applicable to the system, the method, the program, and the recording medium.

FIG. 2 is a block diagram illustrating a hardware configuration of a printing apparatus. It is explanatory drawing which shows arrangement | positioning of the nozzle group of a print head, and a UV lamp. It is a block diagram which shows the software structure of PC. 6 is a flowchart illustrating a flow of printing processing. It is explanatory drawing of the method of an area | region setting. It is explanatory drawing about adjustment of the area size performed according to the redundancy of an image. It is explanatory drawing concerning calculation of the hardening energy per area | region. It is explanatory drawing explaining the method of specifying the binary data utilized for printing by each scanning pass. It is explanatory drawing explaining the method of determining the quantity of clear ink according to the ink quantity of another ink.

Hereinafter, embodiments of the present invention will be described in the following order.
(1) Configuration of the present embodiment:
(2) Printing process:
(3) Various modifications:
(4) Summary:

(1) Configuration of the present embodiment:
FIG. 1 is a block diagram illustrating a hardware configuration of the printing apparatus according to the present embodiment. As shown in the figure, the printing apparatus of the present embodiment includes a printer 100 and a computer 200 that controls the printer 100. In the present embodiment, the computer 200 constitutes a print control device of the printer 100. In addition, by providing the printer 100 with a software configuration equivalent to the software executed in the computer 200 of the present embodiment, the printer 100 can also configure a printing apparatus.

  In FIG. 1, a printer 100 includes a control unit 105 having a program execution environment realized by a combination of a CPU, a RAM, and a ROM, a carriage controller 110, a carriage motor 112, a carriage 114, a head controller 120, A print head 122, a curing unit 130 including a lighting control circuit 132 and a UV lamp 134, a printing paper feed controller 140, a printing paper feed motor 142, and a USB interface 150 for exchanging data with the computer 200; It has. The units 105, 110, 120, 132, 140, and 150 are connected via a communication line such as a bus, and can communicate with each other under the control of a control controller such as a chip set. The control unit 105 controls the entire printer 100 by performing arithmetic processing according to a program stored in the ROM.

  The print head 122 includes a nozzle group that ejects ink and is mounted on the carriage 114. The carriage 114 is reciprocated in a predetermined direction (main scanning direction) by a carriage motor 112 as a drive mechanism that operates according to the control of the carriage controller 110. The printing paper feed motor 142 is a drive mechanism that transports printing paper in a direction (sub scanning direction) orthogonal to the main scanning direction, and operates according to the control of the printing paper feed controller 140. Each nozzle of the print head 122 is supplied with ink of each color from the ink tank of each color mounted on the carriage 114, and discharges the color ink supplied to the corresponding ink tank under the control of the head controller 120.

  The lighting control circuit 132 inputs a driving voltage to the UV lamp 134 in accordance with a control signal input from the control unit 105 and lights the UV lamp 134. In the present embodiment, the lighting control circuit 132 and the UV lamp 134 constitute a curing unit 130. As the UV lamp 134, for example, a high-pressure mercury lamp, a metal halide lamp, a black light, a cold cathode tube, or an LED can be used. The control unit 105 can form an image on the printing paper by controlling the carriage controller 110, the printing paper feed controller 140, the head controller 120, and the lighting control circuit 132 in conjunction with each other.

  In the printer according to the present embodiment, printing is performed using a total of five types of ink, cyan (C), magenta (M), yellow (Y), black (K), and clear (Cl). CMYK color inks are used to form an image on the printing paper P, and Cl ink is used to form an image overcoat layer. The ink used in the printer 100 of this embodiment is a photocurable ink, for example, an ink composed of a liquid monomer. The photo-curable ink is a color material that is cured and fixed by causing a polymerization reaction to change into a polymer when irradiated with ultraviolet light emitted by the UV lamp 134. That is, the UV lamp 134 irradiates each CMYKCl ink ejected on the printing paper P with ultraviolet light (active energy) to cure the ink. Note that the ink types used for printing are not limited to the five types of CMYKCl, and may be printers that use light color inks such as light cyan and light magenta, and special color inks such as metallic colors and pastel colors. Further, the object to be printed is not limited to the printing paper P, and various printing media such as a plastic film and cloth can be printed.

  FIG. 2 is an explanatory diagram showing the arrangement of the nozzle groups of the print head 122 and the UV lamps 134 in the carriage 114. FIG. 2 shows a relative positional relationship between the print head 122, the UV lamp 134, and the printing paper P. FIG. 2A shows a nozzle group and a UV lamp in the print head 122 suitable for unidirectional printing. FIG. 2B shows an arrangement of nozzle groups and UV lamps 134 in the print head 122 suitable for bidirectional printing.

  As shown in FIGS. 2A and 2B, the print head 122 is provided with a nozzle group for each ink color. The nozzle group 122C for ejecting C ink and the nozzle group for ejecting M ink are provided. 122M, a nozzle group 122Y that discharges Y ink, a nozzle group 122K that discharges K ink, and a nozzle group 122Cl that discharges Cl ink. In addition, the nozzle groups for each ink color are arranged in a line in the sub-scanning direction. These nozzle groups are supplied with ink of corresponding colors from the ink tanks of the respective colors mounted on the carriage.

  In FIG. 2A, nozzle groups 122C, 122M, 122Y, and 122K for CMYK color ink are arranged upstream in the scanning direction, and a nozzle group 122Cl for Cl ink is arranged downstream of the color ink in the scanning direction. ing. In addition, a UV lamp 134 is disposed further downstream of the nozzle group 122Cl. That is, the ink immediately after being ejected from the nozzle groups 122C, 122M, 122Y, 122K, and 122Cl onto the printing paper P can be cured by being irradiated with ultraviolet light.

In FIG. 2B, the number of C ink nozzle groups 122C is one in order to cope with bidirectional printing, but the other ink nozzle groups and two UV lamps are provided. That is, the nozzle group 122C is arranged at the approximate center of the print head 122 in the main scanning direction, and the other nozzle groups 122M, 122Y, 122K, 122Cl are arranged on both sides of the nozzle group 122C, and the nozzle group 122C is arranged. They are arranged in a line-symmetric relationship as the center line. The nozzle group arranged in the center of the print head 122 may be a color ink other than the C ink, but the clear ink nozzle group 122Cl is formed on the outer side of the color ink in order to form an overcoat layer of the color ink. The UV lamp 134 needs to be arranged further outside each nozzle group.
In performing bidirectional printing using the print head 122 in which nozzles and light sources are arranged as shown in FIG. 2B, when printing is performed while moving the carriage 114 in the right direction on the paper surface of FIG. When printing is performed while moving the carriage 114 in the left direction in FIG. 2 using the nozzle group and the light source arranged on the left side, the nozzle group 122C and the nozzle group and the light source arranged on the right side are used.

  In this embodiment, the case where the print head 122 and the UV lamp 134 are mounted on the same carriage 114 has been described as an example. However, a carriage that mounts the print head 122 and moves it in the main scanning direction, and a UV lamp It is also possible to configure the carriage mounted on the carriage 134 and moved in the main scanning direction as a separate body. By separating the carriage of the print head 122 and the carriage of the UV lamp 134, the scanning speed and the scanning path can be determined independently, so that the control processing of each carriage becomes easy.

  Next, the hardware configuration of the PC 200 that controls the printer 100 will be described with reference to FIG. As shown in the figure, the PC 200 includes a CPU 205, a RAM 210, a ROM 215, an HD 220, a display interface 225, an operation input device interface 230, and a USB interface 240. The units 205 to 240 are connected via a communication line such as a bus, and can communicate with each other under the control of a control controller such as a chip set. A display 225a as a display device is connected to the display interface 225. The operation input device interface 230 is connected to a mouse 230a and a keyboard 230b as operation input devices. The USB interface 240 is communicably connected to the USB interface 150 of the printer 100.

  In the PC 200 described above, a function as the printer driver PDrv is realized by executing a printer driver program on basic software such as an operating system. In the present embodiment, the printer driver PDrv has functions corresponding to the modules M1 to M6 shown in FIG.

FIG. 3 is a block diagram showing a software configuration of the PC 200.
As shown in the figure, the image data acquisition unit M1 acquires image data as an input image data ID from an application program.
The color conversion unit M2 is a module that converts the input image data ID into ink amount data with reference to a color conversion lookup table (LUT). Specifically, the color conversion unit M2 refers to a color conversion LUT (not shown) stored in advance in the HD 220 or the like, and converts the RGB data of each pixel of the input image data ID into a gradation value (CMYK data) for each CMYK color. ). The color conversion LUT is a table in which CMYK data is uniquely associated with a predetermined reference point (RGB data) in the sRGB color space, and the color conversion unit M2 appropriately refers to the color conversion LUT. Arbitrary RGB data can be converted into CMYK data by performing an interpolation operation or the like. In this embodiment, each value of CMYK after color conversion is expressed with 256 gradations.
The halftone processing unit M5 converts CMYK data into halftone data expressed by dot on / off (ink ejection / non-ejection) using a halftone resource (not shown).

  On the other hand, when the generation of the CMYK data by the color conversion unit M2 is completed, the area setting unit M3 virtually divides the print range printed by the image data acquired by the image data acquisition unit M1 into two or more areas. To do. Then, the energy calculation unit M4 calculates an ink amount necessary for printing each region divided by the region setting unit M3 for each region, and calculates a curing energy necessary for curing the calculated ink amount. The processing by the region setting unit M3 and the energy calculation unit M4 may be performed in parallel with the above-described halftone processing.

  When the halftone data is created and the curing energy is calculated as described above, the print data creation unit M6 is raster data for driving the nozzle groups 122C, 122M, 122Y, 122K, and 122Cl of the printer 100. And output to the printer 100. In addition, the print data creation unit M6 creates data for specifying the curing energy to be irradiated in each region, and outputs the data to the printer 100. In the present embodiment, information for specifying which region of each dot data constituting the halftone data is data for forming an image, information for specifying the region, and curing energy to be irradiated in each region The energy conversion table ELUT that defines the correspondence relationship is created.

(2) Printing process:
FIG. 4 is a flowchart showing the flow of the printing process.
In step S100 (hereinafter, “step” is omitted), the image data acquisition unit M1 acquires image data input from the application program as an input image data ID. The input image data ID is dot matrix data in which each element color of R (red), G (green), and B (blue) is expressed in gradation to define the color of each pixel, and is expressed in accordance with the sRGB standard. Color system is used. Of course, various data such as JPEG image data using the YCbCr color system and image data using the CMYK color system can also be used. In S100, a predetermined resolution conversion process according to the output resolution of the printer 100 is performed on the input image data ID as necessary.

  In S105, the color conversion unit M2 converts the color system of the input image data ID into a combination of ink amount data of each ink used by the printer 100.

In step S110, the region setting unit M3 specifies a print range (printing surface) to be printed by image data, and virtually divides the print range into a plurality of regions. In the following description, it is assumed that the area is divided into n areas.
FIG. 5 is an explanatory diagram of a region setting method performed by the region setting unit M3.
In the example shown in FIG. 5A, a user interface for setting the number of divisions is displayed, and region division is performed using values input by the user via this user interface. In the figure, since the user inputs 3 as the vertical division number and 2 as the horizontal division number, the user inputs 6 divisions. When the area is divided, each area is given an area number for specifying the area.

  Further, the division number may be determined based on the user's setting indirectly based on the information designated by the user, instead of directly setting the division number by the user. The information designated by the user is, for example, the size of the printing paper. In this case, the print driver size specified by the user in the user interface of the printer driver displayed by calling from the application program is acquired, and the number of divisions set in advance for each paper size and type is acquired. Divide the area.

In the example shown in FIGS. 5B and 5C, the number of divisions is automatically determined based on the analysis result of the image data. At this time, the area setting unit M3 first analyzes the image data and extracts a feature amount corresponding to the pattern included in the image data. As the feature amount, it is possible to use the frequency of image data, the intensity distribution of edges, the distribution of ink amount data, and the like. For example, the mode value in these distributions can be used as a feature amount indicating redundancy.
The region setting unit M3 has a plurality of stepwise thresholds for redundancy, and the number of divisions suitable for each step is associated. The region setting unit M3 can automatically determine the number of divisions suitable for the redundancy of the image data by comparing each threshold value with the feature amount. More specifically, for example, in the case of a landscape image as shown in FIG. 5 (b), it is determined that the image is highly redundant, and the number of divisions is set to be small. In the case of an image, it is determined that the image has low redundancy, and a large number of divisions are set.

Further, the area size may be adjusted in consideration of the redundancy of each area.
FIG. 6 is an explanatory diagram for adjustment of the region size performed in accordance with image redundancy. As shown in the figure, when adjusting the region size according to the redundancy, first, the number of divisions is set to a predetermined number, and the redundancy feature amount is calculated for each region. If the redundancy feature amount is within the predetermined reference range, the region is maintained as it is. If the redundancy feature amount is higher than the predetermined reference range, the region is integrated into the adjacent region. On the other hand, if the redundancy feature quantity is lower than the predetermined reference range, the area is further divided into smaller parts, the redundancy feature quantity is calculated for each area, and the redundancy feature quantity of each area is set to the predetermined reference range. It is determined whether or not it is within the range, those having higher redundancy than the reference range are integrated into adjacent regions, and the number of divisions is further increased for regions having lower redundancy than the reference range. Note that if the divided area becomes smaller than the resolution of the UV lamp 134, it becomes impossible to irradiate light with different energy for each area. Therefore, it is preferable to limit the lower limit of the size of the divided area to be equal to or higher than the resolution of the UV lamp 134. .

In S115, the energy calculation unit M4 calculates a necessary ink amount for each region set by dividing in S110.
FIG. 7 is an explanatory diagram for calculating the curing energy per region. As shown in the figure, the energy calculation unit M4 calculates the total ink amount for each region for each ink color. In the figure, for region n, the total ink amount Cn of C ink, the total ink amount Mn of M ink, the total ink amount Yn of Y ink, the total ink amount Kn of K ink, and the total ink amount of Cl ink Cln is calculated. FIG. 7 shows an example in which a predetermined amount of clear ink is ejected in advance for all pixels.

The energy calculation unit M4 has data indicating unit ink amount curing energy E _C , E _M , E _Y , E _K , and E _Cl necessary for curing the unit amount of each color ink. By multiplying the total ink amount of each type by the unit ink amount curing energy of each ink type as a weight, the total curing energy En, which is the total amount of energy required to cure the ink applied to the region n, is calculated. Can do. Then, by dividing the total curing energy En by the area of the region (or the number of pixels), the unit area curing energy en of the ultraviolet light to be irradiated per unit area in the region n is calculated. Then, the energy calculation unit M4 creates an energy conversion table ELUT in which the region number of the region n is associated with the unit area curing energy en calculated corresponding to each region.

  The unit area curing energy en is an amount corresponding to the product of the illuminance of the UV lamp 134 and the irradiation time determined based on the moving speed of the carriage. Therefore, when the moving speed of the carriage is constant, the UV lamp A value indicating the illuminance of 134 may be used. Conversely, when the illuminance of the UV lamp 134 is constant, a value indicating the moving speed of the carriage may be used. In addition, when the unit ink amount curing energy of each ink is distributed within a predetermined energy range and there is no significant difference for each ink, the average value of the unit ink amount curing energy of each ink is calculated without performing the above-described weighting. The total curing energy En may be calculated by multiplying the sum of the ink amounts of all ink colors.

When the unit area curing energy en is calculated as described above, in S120, the halftone processing unit M5 executes halftone processing on the CMYK data. As a result, binary data BD (halftone data) that defines ON / OFF of each ink color dot for each pixel is obtained.
In S125, the print data creation unit M6 receives the binary data BD, converts the binary data BD into raster data for driving the nozzles of the nozzle groups 122C, 122M, 122Y, 122K, and 122Cl, and the printer. Sequentially output to 100. Information specifying the region number to which each binary data belongs is assigned to each binary data constituting the raster data. In step S <b> 130, the print data creation unit M <b> 6 also outputs the above-described energy conversion table ELUT to the printer 100. Then, the printer 100 refers to the energy conversion table ELUT described above, specifies the illuminance to be irradiated when printing each binary data, and ultraviolet light is printed at the location where each binary data is printed with the specified illuminance. Control data for irradiating light is input to the lighting control circuit 132. That is, the printer 100 discharges ink from the print head 122 based on the binary data BD and attaches the ink to the printing paper P, and applies the binary to the ink attached based on each binary data. Curing is performed by irradiating the curing unit 130 with ultraviolet light having an illuminance set for the region to which the data belongs. Accordingly, since an appropriate amount of ultraviolet light is applied to each ink attached to the printing paper P, high-quality printing is possible while preventing the quality of the printing paper P and uncured ink.

(3) Various modifications:
(3-1) Modification 1:
In the above-described embodiment, the printing range in the image data printing result is divided into regions, and the unit area curing energy en for each region is calculated. However, the curing energy necessary for each scanning pass of the carriage may be calculated. In this modification, for the sake of simplicity of explanation, a description will be given by taking an example of a pass separation process in which printing for one raster is performed with each nozzle during one reciprocation of the carriage. Of course, even in a complicated pass separation process as disclosed in Japanese Patent Application Laid-Open No. 2009-184344, each scan is specified by specifying binary data given to each nozzle group in printing in each scan pass. The required curing energy can be calculated for each pass.

  FIG. 8 is an explanatory diagram for explaining a technique for specifying binary data used for printing in each scanning pass. As shown in the figure, the binary data BD are arranged in the raster direction (main scanning direction) of the rasters L1 to L4 of the printing paper. That is, after the binary data “A1B1A1B1...” Of the raster L1, the binary data “A2B2A2B2...” Of the raster L2 and the binary data “A3B3A3B3. Then, the binary data “A4B4A4B4...” Of the raster L4 follows. In the present modification, for the sake of simplicity of explanation, the print head 122 includes four nozzles, and four rasters L1 to L4 are printed in two passes A and B. That is, “An” of binary data BD (n is an integer indicating the number of rows) is printed in pass A, and “Bn” of binary data BD is printed in the next pass B.

  First, the energy calculation unit M4 divides the binary data BD arranged in the raster direction into binary data for each head path. In other words, the binary data of path A is “A1A1A1A1...” Of raster L1, “A2A2A2A2...” Of raster L2, “A3A3A3A3. . ”Is generated as binary data BDA rearranged in the order of“. ”, And binary data of path B is also generated as binary data BDB rearranged in the same manner.

  Next, the energy calculation unit M4 rearranges the binary data BDA and BDB of each pass in the order of the nozzles 1 to 4 of the print head 122. This nozzle forward conversion process is a so-called horizontal / vertical conversion process in which the binary binary data BDA and BDB are rearranged in the order of the nozzles 1 to 4 in the nozzle direction. As a result, the binary data BDA of pass A is rearranged as “A1A2A3A4A1A2A3A4...” Like the nozzle order data NData_A by the nozzle order conversion process. Similarly, the binary data BDB of pass B is rearranged as “B1B2B3B4B1B2B3B4...” Like the nozzle order data NData_B by the nozzle order conversion process.

  The energy calculation unit M4 can obtain the total amount of ink ejected on the printing paper in each pass by accumulating the binary data of each pass, so that the total amount of ink corresponds to the ink type. The unit area curing energy en is calculated by multiplying the unit ink amount curing energy to calculate the total curing energy En and dividing the total curing energy En by the area where the nozzles 1 to 4 perform printing in one scanning pass. Based on the unit area curing energy en thus calculated, an energy conversion table ELUT is created in which the scanning pass number for specifying the scanning path and the unit area curing energy en are associated with each other. The energy conversion table ELUT created in this way is output to the printer 100 together with the raster data. In this modification, the curing energy can be specified by specifying the scanning path with reference to the energy conversion table ELUT. Therefore, the area number is not assigned to each dot data, but the scanning path is specified for each raster data. Information may be given.

(3-2) Modification 2:
In the above-described embodiment, the amount of clear ink is constant for all pixels. However, the amount of clear ink is equal to that of other inks so that the total amount of ink of all inks in all pixels is averaged. A value determined according to the ink amount may be used.

  FIG. 9 is an explanatory diagram for explaining a method of determining the amount of clear ink according to the amount of other ink. In the drawing, for the sake of simplicity, one raster data constituting one area is partially shown, and the amount of ink ejected for each pixel is shown in height. In this modification, the pixel having the largest ink amount in the region is used as a reference, and a value obtained by adding the minimum clear ink amount necessary for overcoat to the ink amount of this pixel is calculated. That is, when the minimum clear ink amount necessary for overcoat is I_min (Cl), the ink amount of the pixel with the largest ink amount in the region is detected as I_max, and the ink amount of each pixel is averaged. Is set to I_max + Imin (Cl).

  Then, a total ink amount is calculated by adding the ink amounts of CMYK colors in each pixel in the region, and the difference (I_avr−Ipix) between the total ink amount and the target ink amount I_avr is calculated as the ink amount of Cl ink in each pixel. And In this way, by determining the ink amount of the clear ink so that the ink amount in each pixel is averaged, the surface in the printing result can be formed smoothly and the ink is cured between the pixels. The energy required for cease to fluctuate greatly. Of course, since the required curing energy differs for each ink type, the image quality can be improved by dividing the area as in the above-described embodiment and irradiating the UV lamp 134 with ultraviolet light with the necessary energy for each area. Can do.

(3-3) Modification 3:
In the embodiment described above, the unit area curing energy en required per unit area of each region is calculated based on the total ink amount and region area in the region. However, the ink amount of each pixel also varies within the region. is there. Therefore, in order to prevent uncured ink more reliably, a pixel having the largest amount of ink in the region is specified, and each of the inks discharged with an energy corresponding to this pixel can be reliably cured. The area may be irradiated.
That is, when the energy calculation unit M4 specifies a pixel having the largest amount of ink in each area, the energy calculation unit M4 calculates energy necessary to cure the ink of the pixel, and obtains a value obtained by dividing this energy by the area per pixel. The unit area curing energy en is assumed. According to this modification, uncured ink can be reliably prevented.

(3-4) Modification 4:
In the embodiment described above, in calculating the unit area curing energy en, the total curing energy En is divided by the area of each region. However, if the area where ink is ejected in each area is biased, the area irradiated with ultraviolet rays even though the ink amount is 0, or only ultraviolet rays that are insufficient to cure the ink are irradiated. The part which is not done will occur. Therefore, in this modification, in order to prevent such irradiation unevenness, the area for dividing the total curing energy En is adjusted when calculating the unit area curing energy en. In other words, the unit area curing energy en is calculated by excluding the pixels whose ink ejection amount is 0 or less than the predetermined threshold from the area that becomes the denominator when the total curing energy En is removed. In this way, it is possible to prevent at least uncured ink from remaining.

(4) Summary:
The print surface to be printed is divided based on the input image data ID, two or more areas are set, and the amount of ink attached to each of the set areas is calculated based on the input image data ID. Based on the amount of ink, the curing energy necessary for curing the ink attached to each region is calculated, the ink is adhered to the printing paper P based on the input image data ID, and ultraviolet light is applied with the curing energy calculated for each region. The curing unit 130 for irradiating and curing the printing paper P with ultraviolet light is controlled so that light is irradiated. Therefore, when printing is performed by irradiating the photocurable ink attached to the printing paper P by irradiating ultraviolet light, the image quality of the printing result is improved.

  Note that the present invention is not limited to the above-described embodiments and modifications, and the configurations disclosed in the above-described embodiments and modifications are mutually replaced, the combinations are changed, the known technology, and the above-described implementations. Configurations in which the configurations disclosed in the embodiments and modifications are replaced with each other or combinations thereof are also included.

DESCRIPTION OF SYMBOLS 100 ... Printer, 105 ... Control part, 110 ... Carriage controller, 112 ... Carriage motor, 114 ... Carriage, 120 ... Head controller, 122 ... Print head, 130 ... Curing unit, 132 ... Lighting control circuit, 134 ... UV lamp, 140 ... Printing paper feed controller, 142 ... Printing paper feed motor, 150 ... USB interface, 200 ... Personal computer (PC), P ... Printing paper, 122C, 122M, 122Y, 122K, 122Cl ... Nozzle group, Cn, Mn, Yn, Kn, Cln: Total ink amount, E _C , E _M , E _Y , E _K , E _Cl : Unit ink amount curing energy, En: Total curing energy, en: Unit area curing energy, M1: Image data acquisition unit, M2: Color Conversion unit, M3 ... area Setting unit, M4 ... energy calculation unit, M5 ... halftone processing unit, M6 ... print data creation unit, ELUT ... energy conversion table

Claims (6)

A printing apparatus that performs printing using a photocurable color material,
A curing unit that emits light for curing the colorant while moving relative to the print medium;
An image data acquisition unit for acquiring image data;
An area setting unit that divides a print surface to be printed based on the image data into two or more areas;
A color material amount calculation unit that calculates the amount of color material to be attached to each of the regions based on the image data;
An energy calculation unit for calculating a curing energy necessary for curing the color material attached to each of the regions based on the color material amount;
A printing unit that controls the curing unit so that a color material is attached to the print medium based on the image data and the light of the curing energy calculated for each region is irradiated to each of the regions;
A printing apparatus comprising:   The printing unit irradiates the printing medium with light at different illuminances for each region while moving the curing unit at a constant relative speed with respect to the printing medium, so that the energy calculation unit performs each region. The printing apparatus according to claim 1, wherein the curing unit is controlled so that the calculated curing energy is given to each of the regions. The printing unit performs the main scanning in which the print head is reciprocated in the main scanning direction, and performs the sub scanning in which the printing medium is relatively moved with respect to the print head in the sub scanning direction orthogonal to the main scanning direction. A color material is attached to the print medium,
3. The printing apparatus according to claim 1, wherein the area setting unit sets a group of parts to which the color material is attached in each pass of main scanning of the print head as one area. 4. The printing unit performs the main scanning in which the print head is reciprocated in the main scanning direction, and performs the sub scanning in which the printing medium is relatively moved with respect to the print head in the sub scanning direction orthogonal to the main scanning direction. A color material is attached to the print medium,
The printing apparatus according to claim 1, wherein the area setting unit sets each of the areas as one closed area. The printing unit is capable of printing by attaching a plurality of types of color materials to the print medium,
The energy calculation unit is attached to each of the regions by multiplying the color material amount calculated by the color material amount calculation unit by a curing energy per unit amount weighted by a curing characteristic of each color material with respect to the light. The printing apparatus according to claim 1, wherein energy necessary for curing the coloring material is calculated. A printing method for performing printing using a photocurable color material,
An image data acquisition process for acquiring image data;
An area setting step of dividing a print surface to be printed based on the image data into two or more areas;
A color material amount calculating step for calculating a color material amount to be attached to each of the regions based on the image data;
An energy calculating step for calculating energy required to cure the color material attached to each of the regions based on the color material amount;
A coloring material is attached to the print medium based on the image data, and the light of the energy calculated for each region is moved relative to the print medium so that each region is irradiated with light. A printing process for controlling a curing unit that emits light for curing the colorant,
A printing method comprising:

Images