Patent Publication Number: US-2023158810-A1

Title: Inkjet printer

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application claims the benefit of priority to Japanese Patent Application No. 2020-111276 filed on Jun. 29, 2020 and is a Continuation Application of PCT Application No. PCT/JP2021/021010 filed on Jun. 2, 2021. The entire contents of each application are hereby incorporated herein by reference. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates generally to inkjet printers, and more particularly to an inkjet printer using photo-curable ink. 
     2. Description of the Related Art 
     Inkjet printers to print desired images on recording media by inkjet printing methods are known in the related art. JP 2011-161824 A, for example, discloses an inkjet printer including a first ink head to discharge colored ultraviolet-curable ink (hereinafter referred to as “colored ink”), a second ink head to discharge transparent ultraviolet-curable ink (hereinafter referred to as “clear ink”), an ultraviolet light applicator to apply ultraviolet light to the ultraviolet-curable ink discharged onto a recording medium, a carriage equipped with the first ink head, the second ink head, and the ultraviolet light applicator and movable in a main scanning direction, and a conveyor to convey the recording medium in a feeding direction. 
     JP 2011-161824 A discloses a layer printing technique involving discharging the colored ink from a first discharging region of the first ink head located on a rear side in the feeding direction so as to form a colored image on a surface of the recording medium, then conveying the recording medium in the feeding direction, and subsequently discharging the clear ink from a second discharging region of the second ink head located on a front side in the feeding direction so as to form a clear image (which has an uneven surface) in a linear pattern on the colored image. JP 2011-161824 A suggests that such layer printing changes the appearance of the colored image so as to decorate the colored image. 
     SUMMARY OF THE INVENTION 
     As described in JP 2011-161824 A, the technique known in the related art involves separately and sequentially performing the step of forming a colored image by using colored ink and the step of forming a clear image by using clear ink. When a colored image and a clear image are to be formed separately, however, the time required for printing will increase, resulting in a lower printing throughput. Forming a clear image having an uneven surface on a colored image enables expression of a texture of a printed matter, which includes, for example, making a visual change to the printed matter or causing the printed matter to provide a tactile sensation. Forming a clear image on a colored image, however, may give different glosses (e.g., different optical reflectances) to a portion where the clear image is formed and a portion where no clear image is formed (e.g., a portion where the colored image is exposed). This may unfortunately cause a user to feel strange about the appearance of the resulting printed matter. 
     Accordingly, preferred embodiments of the present invention provide new inkjet printers that are each able to prevent or minimize decreases in printing throughput and to prevent or reduce differences in gloss so as to provide printed matters that make users feel less strange about the appearances of the printed matters while maintaining uneven textures of the printed matters. 
     An inkjet printer according to a preferred embodiment of the present invention includes an ink head including nozzles to discharge photo-curable ink onto a recording medium, a light applicator to apply light to the photo-curable ink discharged onto the recording medium, a carriage equipped with the ink head, a mover to move either one of the carriage and the recording medium relative to the other one of the carriage and the recording medium in a first direction, and a controller to control the ink head, the light applicator, and the mover. The nozzles include first nozzles to discharge colored photo-curable ink, and second nozzles to discharge transparent photo-curable ink. The ink head includes a colored ink nozzle group in which the first nozzles are provided along a second direction perpendicular or substantially perpendicular to the first direction, and a transparent ink nozzle group in which the second nozzles are provided along the second direction. The controller includes a first discharge controller configured or programmed to, when either one of the carriage and the recording medium makes a single movement from one side to the other side in the first direction, cause the colored ink nozzle group to discharge the colored photo-curable ink onto a predetermined region while causing the transparent ink nozzle group to discharge the transparent photo-curable ink onto the predetermined region so as to form a colored image and a texture image. The texture image includes the colored photo-curable ink and the transparent photo-curable ink that overlap with each other. 
     An inkjet printer according to another preferred embodiment of the present invention includes an ink head including nozzles to discharge photo-curable ink onto a recording medium, a light applicator to apply light to the photo-curable ink discharged onto the recording medium, a carriage equipped with the ink head, a mover to move either one of the carriage and the recording medium relative to the other one of the carriage and the recording medium in a first direction, and a controller to control the ink head, the light applicator, and the mover. The nozzles include first nozzles to discharge colored photo-curable ink, and second nozzles to discharge transparent photo-curable ink. The ink head includes a colored ink nozzle group in which the first nozzles are provided along a second direction perpendicular or substantially perpendicular to the first direction, and a transparent ink nozzle group in which the second nozzles are provided along the second direction. The controller includes a print signal receiver to receive colored ink print data for discharge of the colored photo-curable ink and transparent ink print data for discharge of the transparent photo-curable ink, and a first discharge controller configured or programmed to, when either one of the carriage and the recording medium makes a single movement from one side to the other side in the first direction, cause the colored ink nozzle group to discharge the colored photo-curable ink onto a predetermined region in accordance with the colored ink print data while causing the transparent ink nozzle group to discharge the transparent photo-curable ink onto the predetermined region in accordance with the transparent ink print data such that at least some of the colored photo-curable ink overlaps with the transparent photo-curable ink. 
     The inkjet printers according to the above preferred embodiments each discharge colored photo-curable ink and transparent photo-curable ink in a single round of scanning (i.e., when either one of the carriage and the recording medium makes a single movement from one side to the other side in the first direction relative to the other one of the carriage and the recording medium). Thus, the inkjet printers according to the above preferred embodiments are each able to make the time required for printing shorter and prevent or minimize a decrease in printing throughput to a higher degree than an inkjet printer that discharges colored photo-curable ink and transparent photo-curable ink in different rounds of scanning. The inkjet printers according to the above preferred embodiments each discharge colored photo-curable ink and transparent photo-curable ink onto a predetermined region on the recording medium so as to form an image including the colored photo-curable ink and the transparent photo-curable ink that overlap with each other. In one example, the inkjet printers according to the above preferred embodiments each form not only a colored image including colored photo-curable ink but also a texture image including colored photo-curable ink and transparent photo-curable ink that overlap with each other. Accordingly, unlike layer printing involving forming a clear image on a colored image (which is disclosed, for example, in JP 2011-161824 A), the inkjet printers according to the above preferred embodiments are each able to reduce differences in surface gloss that are caused by an unclear boundary between a region where transparent photo-curable ink is provided and a region where no transparent photo-curable ink is provided. Consequently, the inkjet printers according to the above preferred embodiments are able to prevent or reduce differences in gloss so as to provide printed matters that make users feel less strange about the appearances of the printed matters while maintaining uneven textures of the printed matters. 
     Various preferred embodiments of the present invention provide inkjet printers that are each able to prevent or minimize decreases in printing throughput and to prevent or reduce differences in gloss so as to provide printed matters that make users feel less strange about the appearances of the printed matters while maintaining uneven textures of the printed matters. 
     The above and other elements, features, steps, characteristics and advantages of the present invention will become more apparent from the following detailed description of the preferred embodiments with reference to the attached drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The patent or application file contains at least one drawing executed in color. Copies of this patent or patent application publication with color drawing(s) will be provided by the Office upon request and payment of the necessary fee. 
         FIG.  1    is a front view of an inkjet printer according to a preferred embodiment of the present invention. 
         FIG.  2    is a bottom view of a carriage. 
         FIG.  3    is a partial vertical cross-sectional view of a head portion. 
         FIG.  4    is a functional block diagram illustrating a configuration of a controller. 
         FIGS.  5 A to  5 C  are plan views of the printer, illustrating how the printer operates in effecting multi-pass printing. 
         FIG.  6    is a schematic plan view of an exemplary printed matter. 
         FIG.  7    is an enlarged cross-sectional view of a portion of the printed matter illustrated in  FIG.  6   . 
         FIG.  8 A  is a schematic plan view of a variation of a texture image. 
         FIG.  8 B  is a schematic cross-sectional view of a portion of the texture image illustrated in  FIG.  8 A . 
         FIG.  9 A  is a schematic plan view of a variation of a pattern shape. 
         FIG.  9 B  is a schematic cross-sectional view of the pattern shape illustrated in  FIG.  9 A . 
         FIG.  10 A  is a schematic plan view of another variation of a pattern shape. 
         FIG.  10 B  is a schematic cross-sectional view of the pattern shape illustrated in  FIG.  10 A . 
         FIG.  11 A  is a schematic plan view of still another variation of a pattern shape. 
         FIG.  11 B  is a schematic cross-sectional view of the pattern shape illustrated in  FIG.  11 A . 
         FIG.  12 A  is a schematic plan view of yet another variation of a pattern shape. 
         FIG.  12 B  is a schematic cross-sectional view of the pattern shape illustrated in  FIG.  12 A . 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Inkjet printers according to preferred embodiments of the present invention will be described below with reference to the drawings. The preferred embodiments described below are naturally not intended to limit the present invention in any way. Components and elements having the same functions are identified by the same reference signs, and description thereof will be simplified or omitted when deemed redundant. 
     As used herein, the term “inkjet printer” refers to any of various printers that use inkjet printing methods known in the related art, such as continuous methods (e.g., a binary deflection method and a continuous deflection method) and various on-demand methods (e.g., a thermal method and a piezoelectric method). The term “printer” includes, but is not limited to, a two-dimensional (2D) printer to print a two-dimensional image and a three-dimensional (3D) printer (e.g., a three-dimensional printing apparatus) to print a three-dimensional object. 
       FIG.  1    is a front view of an inkjet printer  1  (which may hereinafter be simply referred to as a “printer 1”). The printer  1  is a 2D printer. In the following description, the terms “left”, “right”, “up”, and “down” respectively refer to left, right, up, and down with respect to a user (i.e., a person who uses the printer  1 ) facing the front of the printer  1 . A direction away from the rear of the printer  1  and toward the user is a forward direction, and a direction away from the user and toward the rear of the printer  1  is a rearward direction. The reference signs F, Rr, L, R, U, and D in the drawings respectively represent front, rear, left, right, up, and down. The reference sign X in the drawings represents a sub-scanning direction (which corresponds to a front-rear direction). The reference sign Y in the drawings represents a main scanning direction (which corresponds to a right-left direction). The reference sign Z in the drawings represents an up-down direction. The main scanning direction Y is an example of a first direction. The sub-scanning direction X is an example of a second direction perpendicular or substantially perpendicular to the first direction. The up-down direction Z is an example of a direction of thickness of a recording medium  2  and an image formed thereon. These directions, however, are defined merely for the sake of convenience of description and do not limit in any way how the printer  1  may be installed. 
     The printer  1  is a large printer to print images on the recording medium  2  of a large-format type. The recording medium  2  is an object on which images are to be printed. In the present preferred embodiment, the recording medium  2  is a medium in a roll form, which is, for example, “a roll of paper”. Alternatively, the recording medium  2  may be in any form other than a roll form. A material for the recording medium  2  is not limited to any particular material. The recording medium  2  may typically be paper, such as plain paper or inkjet printing paper. Other examples of materials for the recording medium  2  include sheets made of resins, such as polyvinyl chloride (PVC), polyethylene terephthalate, and polyester; plates made of various materials, such as aluminum, iron, stainless steel, wood, glass, and rubber; fabrics, such as a woven fabric and a nonwoven fabric; and leather. The recording medium  2  may be any medium made of material(s) other than those just mentioned. As used herein, the term “image” refers to any layer (s) formed on and/or over the recording medium  2  by using ink. Examples of images include a character, a numeral, a symbol, a figure, a design, a pattern, and a solid fill. 
     As illustrated in  FIG.  1   , the printer  1  includes a platen  3 , a guide rail  4 , a casing  9 , a carriage  10 , a carriage mover  11 , an ink head  12 , ultraviolet (UV) lamps  17 , and a controller  20 . The casing  9  serves as a housing of the printer  1 . The casing  9  extends in the main scanning direction Y. The right end of the casing  9  is provided with an operation panel  9 A. The operation panel  9 A is equipped with a display to present information, such as an operating status, and input elements, such as keys to be operated by the user. 
     The platen  3  supports the recording medium  2  during printing. The platen  3  is provided inside the casing  9 . The platen  3  extends in the main scanning direction Y. The platen  3  is disposed below the guide rail  4 . At least a portion of the platen  3  is disposed in parallel or substantially in parallel with the guide rail  4 . The platen  3  is disposed below the carriage  10 . The recording medium  2  is placed on the platen  3 . Pinch rollers  5 A are provided above the platen  3 . The pinch rollers  5 A press the recording medium  2  from above. Grit rollers  5 B are provided in the platen  3  such that the grit rollers  5 B each face an associated one of the pinch rollers  5 A. The grit rollers  5 B are connected to a feed motor  5 C (see  FIG.  4   ). 
     The feed motor  5 C is electrically connected to the controller  20  and is thus controlled by the controller  20 . The grit rollers  5 B are rotatable upon receiving a driving force from the feed motor  5 C. With the recording medium  2  held between each pinch roller  5 A and the associated grit roller  5 B, rotation of the grit rollers  5 B conveys the recording medium  2  in the sub-scanning direction X (which corresponds to the front-rear direction in  FIG.  1   ). In the present preferred embodiment, the pinch rollers  5 A, the grit rollers  5 B, and the feed motor  5 C function as a conveyor to move the recording medium  2  in the sub-scanning direction X. The conveyor just described is given by way of example only. The conveyor is not limited to any particular configuration, structure, or arrangement. 
     The guide rail  4  is provided in the casing  9 . The guide rail  4  extends in the main scanning direction Y. The guide rail  4  is disposed above the platen  3 . The carriage  10  is in slidable engagement with the guide rail  4 . The carriage  10  is disposed inside the casing  9 . The carriage  10  is equipped with the ink head  12  and the UV lamps  17  (which will be described below). The carriage mover  11  moves the carriage  10  in the main scanning direction Y. 
     The carriage mover  11  includes a pulley  6 L disposed on the left of the guide rail  4 , a pulley  6 R disposed on the right of the guide rail  4 , an endless belt  7  wound around the pulleys  6 L and  6 R, and a carriage motor  8  connected to the pulley  6 R. The carriage  10  is secured to the belt  7 . The carriage motor  8  is electrically connected to the controller  20  and is thus controlled by the controller  20 . Driving the carriage motor  8  rotates the pulley  6 R, causing the belt  7  to run. The carriage  10  thus moves along the guide rail  4  in the main scanning direction Y (i.e., the right-left direction in  FIG.  1   ) together with the ink head  12  and the UV lamp  17  mounted on the carriage  10 . The main scanning direction Y includes a first scanning direction and a second scanning direction opposite to the first scanning direction. The first scanning direction extends from a first side to a second side in the main scanning direction Y (i.e., from left to right in  FIG.  1   ). The second scanning direction extends from the second side to the first side in the main scanning direction Y (i.e., from right to left in  FIG.  1   ). Accordingly, the carriage  10  moves in the first scanning direction and the second scanning direction. The carriage mover  11  is an example of a mover to move the carriage  10  in the main scanning direction Y. The mover just described is given by way of example only. The carriage mover  11  is not limited to any particular configuration, structure, or arrangement. 
       FIG.  2    is a bottom view of the carriage  10 . As illustrated in  FIG.  2   , the carriage  10  is provided with the ink head  12  and the UV lamps  17 . In the present preferred embodiment, the number of UV lamps  17  provided on the carriage  10  is two. The ink head  12  is disposed between the two UV lamps  17 . One of the two UV lamps  17  is disposed leftward of the ink head  12 . The other one of the two UV lamps  17  is disposed rightward of the ink head  12 . Accordingly, the printer  1  is able to effect bidirectional printing. The location of the ink head  12  in the present preferred embodiment is described by way of example only. The ink head  12  may be disposed at any other suitable location. The locations of the UV lamps  17  in the present preferred embodiment are described by way of example only. The UV lamps  17  may be disposed at any other suitable locations. 
     The ink head  12  discharges photo-curable ink onto the recording medium  2  so as to form ink dots  31  and  32  (see  FIG.  7   ) on the recording medium  2 . As illustrated in  FIG.  1   , the ink head  12  is disposed above the platen  3 . The ink head  12  faces the recording medium  2 . The ink head  12  is in slidable engagement with the guide rail  4  through the carriage  10 . The ink head  12  includes a first sub-head  121  to discharge colored photo-curable ink (which may hereinafter be simply referred to as “colored ink”), and a second sub-head  122  to discharge transparent photo-curable ink (which may hereinafter be simply referred to as “clear ink”). The first sub-head  121  and the second sub-head  122  are disposed side by side in the main scanning direction Y. In the present preferred embodiment, the first sub-head  121  and the second sub-head  122  are mounted on the same carriage  10 . The first sub-head  121  and the second sub-head  122 , however, do not necessarily have to be mounted on the same carriage  10 . Alternatively, the first sub-head  121  and the second sub-head  122  may be mounted on different carriages. 
     As used herein, the term “clear ink” refers to ink containing no colorant (which is a component that absorbs light of a wavelength in a visible light range) or ink having a colorant content insufficient for a coloring purpose (which is, for example, equal to or lower than about 0.1 percent of the total mass of colorant-containing ink). As used herein, the term “colored ink” refers to any type of ink other than clear ink. The term “colored ink” typically refers to any type of colorant-containing ink. 
     The first sub-head  121  discharges colorant-containing colored ink CO (see  FIG.  3   ), examples of which include color ink and metallic ink. The printer  1  is thus able to print a colored image  42  and a texture image  44  (see  FIG.  6   ). In the present preferred embodiment, the first sub-head  121  includes a head portion  12 C to discharge cyan ink (C), a head portion  12 M to discharge magenta ink (M), a head portion  12 Y to discharge yellow ink (Y), a head portion  12 K to discharge black ink (K) , and two head portions  12 W to discharge white ink (W). Four of these head portions, i.e., the head portions  12 C,  12 M,  12 Y, and  12 K, each discharge process color ink. 
     Six of the head portions, i.e., the head portions  12 C,  12 M,  12 Y,  12 K, and  12 W, are arranged side by side in the main scanning direction Y. The number of head portions included in the first sub-head  121  in the present preferred embodiment is given by way of example only. The first sub-head  121  may include any other suitable number of head portions. The types of colored ink in the present preferred embodiment are given by way of example only. The head portions of the first sub-head  121  may each discharge any other suitable type of colored ink. In one example, the head portions of the first sub-head  121  may discharge ink of light colors, such as light cyan, light magenta, light yellow, and light black. In another example, the head portions of the first sub-head  121  may discharge metallic ink containing metallic pigments, such as silver and gold pigments. In still another example, the number of head portions  12 W to discharge white ink may be one or may be three or more. In yet another example, the first sub-head  121  may include no head portion  12 W. Six of the head portions, i.e., the head portions  12 C,  12 M,  12 Y,  12 K, and  12 W, are each connected to an associated one of ink tanks (not illustrated) storing the colored ink CO. 
     The second sub-head  122  discharges clear ink, e.g., gloss ink to give a gloss to a surface of an image and/or preprocessing primer ink to form an underlying layer or a lining for an image. The printer  1  is thus able to print the texture image  44  (see  FIG.  6   ). In the present preferred embodiment, the second sub-head  122  includes two head portions  12 CL to discharge gloss ink. The two head portions  12 CL are arranged side by side in the main scanning direction Y. The number of head portions included in the second sub-head  122  in the present preferred embodiment is given by way of example only. The second sub-head  122  may include any other suitable number of head portions. The number of head portions included in the second sub-head  122  may be one or may be three or more. The two head portions  12 CL are each connected to an associated one of ink tanks (not illustrated) storing clear ink. 
     The locations of the first sub-head  121  and the second sub-head  122  in the present preferred embodiment are given by way of example only. The first sub-head  121  and the second sub-head  122  may be located at any other suitable locations. The ink head  12  may include more than one first sub-head  121  and/or more than one second sub-head  122 . In one example, the second sub-head  122  may be disposed between more than one first sub-head  121  in the main scanning direction Y. In another example, at least one second sub-head  122  may be disposed on each side of the first sub-head  121 . More specifically, the head portions  12 CL may each be disposed between any two of the head portions  12 C,  12 M,  12 Y,  12 K, and  12 W in the main scanning direction Y, or at least one head portion  12 CL may be disposed on each side of any of the head portions  12 C,  12 M,  12 Y,  12 K, and  12 W. 
     The first sub-head  121  and the second sub-head  122  each discharge photo-curable ink. The photo-curable ink cures upon being exposed to light. The photo-curable ink typically contains a photopolymerization compound, a photopolymerization initiator, and an organic solvent. When necessary, the photo-curable ink may contain various other additives. Examples of the additives may include a colorant (such as a pigment or a dye) , a photosensitizer, a polymerization inhibitor, an ultraviolet light absorber, an antioxidant, a plasticizer, a surfactant, a leveling agent, a thickener, a disperser, an antifoaming agent, and an antiseptic. As used herein, the term “photo-curable ink” refers to ultraviolet-curable ink (which may be referred to as “UV ink”) that cures upon being exposed to ultraviolet light of a wavelength of between about 10 nm and about 400 nm, for example. 
     In one preferred mode, the colored ink CO and clear ink contain similar photopolymerization compounds. The colored ink CO and clear ink preferably each contain, for example, a (meth)acrylate monomer including a (meth)acryloyl group. As used herein, the term “(meth)acryloyl” subsumes “methacryloyl” and “acryloyl”. In another preferred mode, the colored ink CO and clear ink contain similar organic solvents. The colored ink CO and clear ink preferably each contain, for example, an aliphatic hydrocarbon, such as n-hexane. Although described below in more detail, the printer  1  according to the present preferred embodiment cures the colored ink CO and clear ink, with the dots  31  (see  FIG.  7   ) of the colored ink CO and the dots  32  (see  FIG.  7   ) of clear ink mixed at least in the main scanning direction Y on the recording medium  2 . Using the colored ink CO and clear ink containing similar compounds (e.g., using the colored ink CO and clear ink each containing at least either a photopolymerization compound or an organic solvent) increases an affinity between the colored ink CO and clear ink, which facilitates fixing the colored ink CO and clear ink together onto the recording medium  2 . 
     As illustrated in  FIG.  2   , the head portions  12 C,  12 M,  12 Y,  12 K,  12 W, and  12 CL each include, at its surface that faces the recording medium  2  (i.e., its lower surface in the present preferred embodiment), a plurality of nozzles  13  to discharge photo-curable ink. In the present preferred embodiment, the head portions  12 C,  12 M,  12 Y,  12 K,  12 W, and  12 CL include equal numbers of nozzles  13 . Alternatively, some or all of the head portions  12 C,  12 M,  12 Y,  12 K,  12 W, and  12 CL may have different numbers of nozzles  13 . The nozzles  13  are arranged at predetermined pitches (e.g., at pitches of  360  dpi) corresponding to the densities of the dots  31  and  32  (see  FIG.  7   ) to be formed on the recording medium  2 . The nozzles  13  of the head portions  12 C,  12 M,  12 Y,  12 K,  12 W, and  12 CL are all arranged at equal pitches. 
     In the present preferred embodiment, the nozzles  13  of the head portions  12 C,  12 M,  12 Y,  12 K,  12 W, and  12 CL are all equal in diameter. Alternatively, the nozzles  13  of the head portions  12 C,  12 M,  12 Y,  12 K, and  12 W may be equal in diameter to or different in diameter from the nozzles  13  of the head portions  12 CL. In one example, the nozzles  13  of the head portions  12 CL may be larger in diameter than the nozzles  13  of the head portions  12 C,  12 M,  12 Y,  12 K, and  12 W. 
     In the present preferred embodiment, the head portions  12 C,  12 M,  12 Y,  12 K,  12 W, and  12 CL are disposed at corresponding positions in the sub-scanning direction X. The nozzles  13  of the head portions  12 C,  12 M,  12 Y,  12 K, and  12 W and the nozzles  13  of the head portions  12 CL are disposed at corresponding positions in the sub-scanning direction X. The head portions  12 C,  12 M,  12 Y,  12 K,  12 W, and  12 CL each include a nozzle row  13 A. The nozzle rows  13 A each include the nozzles  13  arranged along a length L 1  in the sub-scanning direction X. The nozzle row  13 A included in each of the head portions  12 C,  12 M,  12 Y,  12 K, and  12 W is an example of a colored ink nozzle group. The nozzle row  13 A included in each of the head portions  12 CL is an example of a transparent ink nozzle group. 
     In the present preferred embodiment, the number of nozzle rows  13 A included in each of the four head portions  12 C,  12 M,  12 Y, and  12 K, which discharges ink of one of process colors, is one. The number of nozzle rows  13 A included in the head portions  12 W, which discharge white ink, is greater than the number of nozzle rows  13 A included in each of the head portions  12 C,  12 M,  12 Y, and  12 K. In the present preferred embodiment, the number of nozzle rows  13 A included in the head portions  12 W is two. The number of nozzle rows  13 A included in the head portions  12 CL, which discharge clear ink, is greater than the number of nozzle rows  13 A included in each of the head portions  12 C,  12 M,  12 Y, and  12 K. In the present preferred embodiment, the number of nozzle rows  13 A included in the head portions  12 CL is two. The number of nozzle rows  13 A included in the head portions  12 CL, which discharge clear ink, is equal to the number of nozzle rows  13 A included in the head portions  12 W, which discharge white ink. Each process color is an example of a first color. The nozzle row  13 A included in each of the head portions  12 C,  12 M,  12 Y, and  12 K is an example of a first colored ink nozzle group. 
     The nozzle rows  13 A of the head portions  12 C,  12 M,  12 Y,  12 K,  12 W, and  12 CL are disposed along the same length L 1  in the sub-scanning direction X. The length L 1  is a length measured between the center of a foremost one of the nozzles  13  in the sub-scanning direction X and the center of a rearmost one of the nozzles  13  in the sub-scanning direction X. In the present preferred embodiment, the nozzles  13  of each of the head portions  12 C,  12 M,  12 Y,  12 K,  12 W, and  12 CL are disposed in a line in the sub-scanning direction X so as to define the nozzle row  13 A along the length L 1 . Any suitable number of nozzles  13  may be located at any suitable locations in each nozzle row  13 A. In one example, the nozzles  13  of each nozzle row  13 A may be disposed in a staggered arrangement. 
       FIG.  3    is a partial vertical cross-sectional view of the head portion  12 C. Specifically,  FIG.  3    is a vertical cross-sectional view of the head portion  12 C cut through the center of one of the nozzles  13  of the head portion  12 C. As illustrated in  FIG.  3   , the head portion  12 C includes a hollow case body  14 , a pressure chamber  15  which is defined in the case body  14  and in which a predetermined amount of the colored ink CO is stored, and an actuator  16  to pressurize the colored ink CO inside the pressure chamber  15 . A surface of the pressure chamber  15  (which is the lower surface of the pressure chamber  15  in  FIG.  3   ) is provided with nozzle holes  13   h  passing through the surface of the pressure chamber  15  in the up-down direction Z. The pressure chamber  15  is in communication with the nozzles  13  through the nozzle holes  13   h . 
     The actuator  16  includes a piezoelectric element. The actuator  16  is connected to a diaphragm  14 V defining a portion of the pressure chamber  15 . The actuator  16  is electrically connected to the controller  20  and is thus controlled by the controller  20 . The controller  20  supplies a pulse waveform (or driving pulses) to the actuator  16  so as to cause the head portion  12 C to discharge a predetermined amount of ink. The actuator  16  shrinks or elongates in accordance with the waveform of the driving pulses. The shrinkage or elongation of the actuator  16  deflects the diaphragm  14 V so as to cause the pressure chamber  15  to expand or contract. The contraction of the pressure chamber  15  pressurizes the colored ink CO inside the pressure chamber  15 . Pressurizing the colored ink CO inside the pressure chamber  15  causes the colored ink CO to be discharged from the nozzles  13 . The above description of the head portion  12 C has been given by way of example. The other head portions (i.e., the head portions  12 M,  12 Y,  12 K,  12 W, and  12 CL) may each be similar in structure to the head portion  12 C. 
     The UV lamps  17  apply ultraviolet light to photo-curable ink discharged onto the recording medium  2 . As illustrated in  FIG.  1   , the UV lamps  17  are disposed above the platen  3 . The UV lamps  17  are in slidable engagement with the guide rail  4  through the carriage  10 . The UV lamps  17  each apply light of an ultraviolet wavelength that is able to cure photo-curable ink. In one example, the UV lamps  17  may each be a light-emitting diode (LED). In another example, the UV lamps  17  may each be a fluorescent lamp (which is a low-pressure mercury lamp) or a high-pressure mercury lamp. Each of the UV lamps  17  is an example of a light applicator. The UV lamps  17  do not necessarily have to be mounted on the same carriage  10  as the ink head  12 . In one example, the UV lamps  17  may be mounted on a carriage other than the carriage  10 . In another example, the UV lamps  17  may each be attached to a portion of the casing  9 , such as a wall surface of the casing  9 . The UV lamps  17  are electrically connected to the controller  20  such that the UV lamps  17  are turned ON and OFF by the controller  20 . 
     The controller  20  controls overall operations of the printer  1 . As illustrated in  FIG.  1   , the controller  20  according to the present preferred embodiment is provided inside the casing  9 . The controller  20  is, for example, a microcomputer. The controller  20 , however, does not necessarily have to be provided inside the casing  9 . Alternatively, the controller  20  may be, for example, a general-purpose personal computer disposed outside the casing  9  and communicably connected to the printer  1 . 
     The controller  20  is not limited to any particular hardware configuration. The controller  20  includes, for example, an interface (I/F), a central processing unit (CPU), a read-only memory (ROM), a random-access memory (RAM), and a storage. The I/F receives data, such as print data, from an external device, such as a host computer. The CPU executes commands included in a control program. The ROM stores the program to be executed by the CPU. The RAM is used as a working area where the program is to be expanded. The storage (such as a memory) stores the program and various types of data. 
       FIG.  4    is a functional block diagram of the controller  20 . The controller  20  is communicably connected to the feed motor  5 C, the carriage motor  8  of the carriage mover  11 , the actuators  16  of the ink head  12 , and the UV lamps  17 . The controller  20  is configured or programmed to be able to control the feed motor  5 C, the carriage motor  8 , the actuators  16 , and the UV lamps  17 . The controller  20  includes a print signal receiver  21 , a feed controller  22 , a scanning controller  23 , a discharge controller  24 , an application controller  25 , and a storage  26 . These components of the controller  20  are able to communicate with each other. The functions of these components of the controller  20  may be implemented by software or may be implemented by hardware. The functions of these components of the controller  20  may be performed by a single processor or a plurality of processors or may be incorporated into circuit(s). 
     Although described below in more detail, the controller  20  alternately repeats a conveying operation to be performed by the feed controller  22 , and a printing operation (which corresponds to a pass) to be performed by the scanning controller  23 , the discharge controller  24 , and the application controller  25 . Alternately repeating the conveying operation and the printing operation effects printing on the recording medium  2 . The colored image  42  (see  FIG.  6   ) and the texture image  44  (see  FIG.  6   ) are thus formed on the recording medium  2 . As used herein, the term “texture image” refers to an image formed on the recording medium  2  so as to be greater in irregularity (or surface roughness) than the colored image  42  formed by discharging only colored ink. Forming the texture image  44  on the recording medium  2  provides a texture to a surface of a printed matter  40  (see  FIG.  6   ) or provides a texture to, for example, the recording medium  2  and/or the colored image  42 . 
     As used herein, the term “printing operation” refers to an operation involving causing the ink head  12  to discharge photo-curable ink onto the recording medium  2  and causing the UV lamps  17  to apply ultraviolet light to the photo-curable ink discharged onto the recording medium  2 , while moving the carriage  10  in the main scanning direction Y. As used herein, the term “single printing operation” refers to an operation involving a single movement of the carriage  10  from the first side to the second side in the main scanning direction Y (i.e., from left to right in  FIG.  1   ) or a single movement of the carriage  10  from the second side to the first side in the main scanning direction Y (i.e., from right to left in  FIG.  1   ). 
     The print signal receiver  21  receives print data and print setting information from an external device (not illustrated), such as a host computer. The print data represents image (s) . Creating the print data involves creating image files in various formats by using, for example, a computer, and converting (or rasterizing) the image files into format(s), which is/are readable by the printer  1 , by using a computer program, such as a raster image processor. The print data is, for example, raster format data. The print data associates each print region (e.g., each unit of pixels), which is included in a printable area, with information indicating what type of photo-curable ink is to be provided. 
     In the present preferred embodiment, the print data includes colored ink print data that defines a colored ink provided region where the colored ink CO is to be provided, and transparent ink print data that defines a clear ink provided region where clear ink is to be provided. The colored ink print data is used to form the colored image  42  (see  FIG.  6   ) and the texture image  44  (see  FIG.  6   ). The transparent ink print data is used to form the texture image  44 . In one example, the colored ink print data and the transparent ink print data that are superposed on one another (or combined with each other) with reference to a printing start position may be transmitted from an external device. In another example, the colored ink print data and the transparent ink print data that are separate from and independent of each other may be individually transmitted from an external device. 
     The transparent ink print data may be freely selectable by the user from among a plurality of patterns prepared in advance. The transparent ink print data may be, for example, a regular pattern formed by repeating a design. The clear ink provided region defined by the transparent ink print data may be an entirety or a portion of a printable area. The locations of the clear ink provided region and the colored ink provided region on the recording medium  2  (i.e., the locations of the clear ink provided region and the colored ink provided region in a plan view) may overlap with each other or may not overlap with each other. 
     The print setting information includes ink discharge settings for print regions. The ink discharge settings may include, for example, at least one of the following pieces of information the fluid volume of ink to be discharged from the nozzles  13  per unit area of the recording medium  2 , the dimensions of the dots  31  and  32  (see  FIG.  7   ) to be formed, e.g., the sizes and thicknesses of the dots  31  and  32  in a plan view, and the formation densities of the dots  31  and  32 . 
     The dots  32  (see  FIG.  7   ) of clear ink may be set to have the same dimensions across an entirety of the clear ink provided region. For example, when the clear ink provided region is defined in both of a portion where the colored image  42  (see  FIG.  6   ) is to be printed and a portion where no colored image  42  is to be printed, the dimensions of the dots  32  of clear ink in the portion where the colored image  42  is to be printed may be set to be different from the dimensions of the dots  32  of clear ink in the portion where no colored image  42  is to be printed. In one example, the dots  32  of clear ink may be set to have first dimensions in the portion where no colored image  42  is to be printed and may be set to have second dimensions, which are relatively larger than the first dimensions, in the portion where the colored image  42  is to be printed. Alternatively, the dots  32  of clear ink may be set to have various dimensions in the portion where the colored image  42  is to be printed. 
     The formation density of dots is the proportion of pixels, for which dots are to be formed, to pixels located in a predetermined region (i.e., the number of unit pixels). The dots  32  (see  FIG.  7   ) of clear ink may be set to have the same formation density across the entirety of the clear ink provided region. For example, when the clear ink provided region is defined in both of a portion where the colored image  42  is to be printed and a portion where no colored image  42  is to be printed, the formation density of the dots  32  of clear ink in the portion where the colored image  42  is to be printed may be set to be different from the formation density of the dots  32  of clear ink in the portion where no colored image  42  is to be printed. In one example, the dots  32  of clear ink may be set to have a first formation density in the portion where no colored image  42  is to be printed and may be set to have a second formation density, which is relatively higher than the first formation density, in the portion where the colored image  42  is to be printed. 
     The feed controller  22  controls the conveying operation. The feed controller  22  controls movement of the recording medium  2  in the sub-scanning direction X. The feed controller  22  controls driving of the feed motor  5 C. The feed controller  22  controls the feed motor  5 C so as to sequentially convey the recording medium  2 , for example, from an upstream side (or rear side) to a downstream side (or front side) in the sub-scanning direction X. The feed controller  22  feeds the recording medium  2  forward by a predetermined conveyance width for each conveying operation. The conveyance width is a distance equal to or shorter than the length L 1  of each nozzle row  13 A of the ink head  12  in the sub-scanning direction X. The conveyance width is set in advance and may be stored in the storage  26 . The conveyance width is, for example, one-half, one-fourth, one-eighth, or one-sixteenth the length L 1  of each nozzle row  13 A. 
     The scanning controller  23  controls the printing operation. The scanning controller  23  controls movement of the carriage  10  in the main scanning direction Y. The scanning controller  23  controls driving of the carriage motor  8 . The scanning controller  23  controls the carriage motor  8  so as to cause the carriage  10  to move (or scan) in the first scanning direction and the second scanning direction. The first scanning direction extends from the first side to the second side in the main scanning direction Y (i.e., from left to right in  FIG.  1   ). The second scanning direction extends from the second side to the first side in the main scanning direction Y (i.e., from right to left in  FIG.  1   ). The scanning controller  23  causes the carriage  10  to move (or scan) in the main scanning direction Y once or more than once each time the recording medium  2  is fed forward by the predetermined conveyance width by the feed controller  22 . 
     The storage  26  preliminarily stores a common driving signal including a plurality of pulse waveforms (or driving pulses) for discharge of a predetermined amount of ink. The common driving signal may be able to form, for example, three types of dots having different dimensions, such as a small dot, a medium dot, and a large dot. The common driving signal may be able to generate a small dot driving signal, a medium dot driving signal, and a large dot dedicated driving signal each including a single driving pulse or two or more driving pulses for a preset unit time (or driving period) that is a period of time during which a single dot is to be formed. At least some of the driving pulses may be a waveform including a waveform element to cause the voltage(s) across the actuator (s)  16  to drop to lower level (s) so as to expand the pressure chamber(s)  15 , a waveform element to maintain the voltage (s) at the lower level (s) so as to keep the pressure chamber(s)  15  in the expanded state, and a waveform element to raise the voltage(s), which have/has been maintained at the lower level(s), so as to cause the pressure chamber(s)  15  to contract. 
     The discharge controller  24  controls the printing operation. In accordance with the print data, the discharge controller  24  causes the ink head  12  (i.e., at least one of the first sub-head  121  and the second sub-head  122 ) to discharge photo-curable ink so as to form an image on the recording medium  2 . The discharge controller  24  supplies the driving pulse(s) to the actuator(s)  16 . Specifically, the discharge controller  24  selects, from among the driving pulses included in the common driving signal, a single driving pulse or two or more driving pulses within a driving period in accordance with, for example, the dimensions of dots to be formed, and then supplies the selected driving pulse(s) to the actuator(s)  16 . In accordance with the selected driving pulse(s), the discharge controller  24  changes the fluid volume of photo-curable ink to be discharged from the nozzles  13  and decides the dimensions of dots to be formed on the recording medium  2 . 
     In the present preferred embodiment, the discharge controller  24  includes a first discharge controller  241 , a second discharge controller  242 , and a third discharge controller  243 . The first discharge controller  241  causes the first sub-head  121  and the second sub-head  122  to discharge ink. The second discharge controller  242  causes only the first sub-head  121  to discharge ink. In other words, the second discharge controller  242  does not cause the second sub-head  122  to discharge ink. The third discharge controller  243  causes only the second sub-head  122  to discharge ink. In other words, the third discharge controller  243  does not cause the first sub-head  121  to discharge ink. 
     The first discharge controller  241  causes the ink head  12  to discharge two types of ink simultaneously along at least a portion of a movement path for the carriage  10  in the main scanning direction Y during a single printing operation (i.e., when the carriage  10  makes a single movement in the first scanning direction or the second scanning direction). Specifically, the first discharge controller  241  causes the first sub-head  121  to discharge, from its nozzles  13 , the colored ink CO and causes the second sub-head  122  to discharge, from its nozzles  13 , clear ink. In other words, the first discharge controller  241  supplies the driving pulse (s) to the actuators  16  of the first sub-head  121  and the second sub-head  122 . In the present preferred embodiment, the first discharge controller  241  supplies the driving pulse(s) to at least the actuators  16  of the first sub-head  121  and the second sub-head  122  that are adjacent to each other in the main scanning direction Y. Accordingly, the colored ink CO and clear ink are discharged onto a target region on the recording medium  2  during a single printing operation. 
     In the present preferred embodiment, the first discharge controller  241  is configured or programmed to form the colored image  42  (see  FIG.  6   ) including the colored ink CO, and the texture image  44  (see  FIG.  6   ) in which the colored ink CO and clear ink are mixed. A region where the texture image  44  is formed (e.g., the clear ink provided region) is relatively greater in irregularity (or surface roughness) than a region where no texture image  44  is formed (e.g., a region where the colored image  42  including the colored ink CO is formed). Accordingly, the present preferred embodiment is able to provide a texture to a surface of the printed matter  40  (see  FIG.  6   ). Actually, a surface of the colored image  42  is also not completely flat. The roughness of the surface of the colored image  42  (which is, for example, a maximum height Rz determined in accordance with JIS B0601: 2013) is about 0.01 mm or lower. An arithmetic average roughness Ra of the region where the texture image  44  is formed is typically greater than the maximum height Rz of the colored image  42  including the colored ink CO. The arithmetic average roughness Ra is a value determined in accordance with JIS B0601: 2013. The same goes for the following description. The arithmetic average roughness Ra is preferably twice or more than twice the maximum height Rz, three times or more than three times the maximum height Rz, or five times or more than five times the maximum height Rz. In one example, the arithmetic average roughness Ra may be 20 times or less than 20 times the maximum height Rz, or may be 10 times or less than 10 times the maximum height Rz. 
     The texture image  44  (see  FIG.  6   ) is typically formed directly on a surface of the recording medium  2 . Alternatively, the texture image  44  may be formed on, for example, a surface of the colored image  42  (see  FIG.  6   ). In some preferred embodiments, the texture image  44  may be a regular pattern formed by repeating a design. The texture image  44  may be a regular pattern including, for example, a single or more than one pattern shape  30  (see  FIG.  7   ). When the texture image  44  is a regular pattern including more than one pattern shape  30 , the pattern shapes  30  may be disposed at predetermined pitches P in a scattered manner. Each pitch P is a distance between the ends of the pattern shapes  30  adjacent to each other (see  FIG.  7   ). In some preferred embodiments, the texture image  44  may not be a regular pattern but may be a random pattern that is not oriented in any particular direction. In some preferred embodiments, the texture image  44  may be a geometric pattern including predetermined figures. Providing the texture image  44  in the form of a geometric pattern effectively changes the appearance of the printed matter  40  (see  FIG.  6   ). 
     In the present preferred embodiment, adjusting, for example, the form, size, and/or location of each pattern shape  30  (see  FIG.  7   ) varies the texture of the surface of the printed matter  40  (see  FIG.  6   ), e.g., the appearance of the printed matter  40  or a tactile sensation that the printed matter  40  provides. In other words, the form, size, and/or location of each pattern shape  30 , for example, are/is preferably adjusted as appropriate so as to provide a desired texture to the printed matter  40 . Although each pattern shape  30  is not limited to any particular form, the external form of each pattern shape  30  may be, for example, an inverted V-form, a conical form, or a polygonal pyramid form. In a plan view, each pattern shape  30  may be, for example, a linear shape, a circular shape (such as an elliptical shape), or a polygonal shape (such as a triangular shape, a quadrangular shape, or a pentagonal shape). When viewed in cross section, each pattern shape  30  may be, for example, a dome shape or a triangular shape whose center is protruded upward, or a bowl shape whose center is recessed. 
     Each pattern shape  30  may have a diameter ϕ of between, for example, about 0.05 mm and about 0.5 mm. When each pattern shape  30  is a polygonal shape, the diameter ϕ is the diameter of a circle equivalent to the area of each polygonal shape (see  FIGS.  6  and  7   ). Each pattern shape  30  may have a height H of between about 0.02 mm and about 0.1 mm. The height H is the maximum height of each pattern shape  30  (see  FIG.  7   ). An average of the heights H of the pattern shapes  30  (hereinafter referred to as an “average height”) is typically greater than the maximum height Rz of the colored image  42 . The average height is preferably twice or more than twice the maximum height Rz, three times or more than three times the maximum height Rz, or five times or more than five times the maximum height Rz. In one example, the average height may be 20 times or less than 20 times the maximum height Rz, or may be 10 times or less than 10 times the maximum height Rz. The pitches P between the pattern shapes  30  (see  FIGS.  6  and  7   ) may each be, for example, between about 0.1 mm and about 1.0 mm. Satisfying at least one of the conditions just described gives a remarkable texture to the printed matter  40  (or enables the printed matter  40  to provide, for example, a remarkable tactile sensation) while maintaining its beautiful appearance. 
     The fluid volume of ink to be discharged per unit area of the recording medium  2  is controllable by, for example, the number of head portions to be used, the dimensions and formation densities of the dots  31  and  32  included in the print setting information, and/or driving pulses for the ink head  12 . In one example, the first discharge controller  241  may control the second sub-head  122  such that the two head portions  12 CL each discharge clear ink. The first discharge controller  241  may control the first sub-head  121  and the second sub-head  122  such that the fluid volume of clear ink to be discharged from each of the nozzles  13  of the second sub-head  122  is larger than the fluid volume of the colored ink CO to be discharged from each of the nozzles  13  of the first sub-head  121 . When the common driving signal includes a first driving pulse to discharge ink by a first discharge amount and a second driving pulse to discharge ink by a second discharge amount larger than the first discharge amount, the first discharge controller  241  may supply the first driving pulse to the first sub-head  121  and supply the second driving pulse to the second sub-head  122 . 
     In the present preferred embodiment, the first discharge controller  241  is configured or programmed to cause the first sub-head  121  and the second sub-head  122  to discharge ink from their nozzles  13  located in corresponding regions in the sub-scanning direction X. In other words, the first discharge controller  241  is configured or programmed to cause the first sub-head  121  and the second sub-head  122  to discharge ink from portions of their nozzle rows  13 A corresponding to each other along at least a predetermined length. 
     For example, assuming that the nozzle rows  13 A are each divided into a plurality of nozzle regions in the sub-scanning direction X and ink is to be discharged from the nozzles  13  included in at least one nozzle region of each nozzle row  13 A, the first discharge controller  241  may be configured or programmed to cause the first sub-head  121  and the second sub-head  122  to discharge ink from the nozzles  13  included in the nozzle regions adjacent to each other in the main scanning direction Y. In this case, the nozzle regions of the first sub-head  121  preferably at least partially correspond in position to the nozzle regions of the second sub-head  122  in the sub-scanning direction X. The nozzle regions of the first sub-head  121  may be different in length from the nozzle regions of the second sub-head  122  in the sub-scanning direction X. The first discharge controller  241  may be configured or programmed to cause the first sub-head  121  and the second sub-head  122  to discharge ink from an entirety of each nozzle row  13 A across the length L 1 . 
     The second discharge controller  242  causes the first sub-head  121  to discharge, from its nozzles  13 , the colored ink CO so as to form only the colored image  42  (see  FIG.  6   ) during a single printing operation (i.e., when the carriage  10  makes a single movement in the first scanning direction or the second scanning direction). The third discharge controller  243  causes the second sub-head  122  to discharge, from its nozzles  13 , clear ink so as to form only the texture image  44  (see  FIG.  6   ) during a single printing operation (i.e., when the carriage  10  makes a single movement in the first scanning direction or the second scanning direction). The second discharge controller  242  and/or the third discharge controller  243  are/is not essential and may be optional in other preferred embodiments. 
     The application controller  25  controls the printing operation. The application controller  25  causes the UV lamps  17  to apply light to photo-curable ink (e.g., the colored ink CO and clear ink), which has been discharged onto the recording medium  2  under control of the discharge controller  24 , so as to cure the photo-curable ink. The application controller  25  controls the UV lamps  17  such that the UV lamps  17  are turned ON and OFF. For example, suppose that the carriage  10  moves in the main scanning direction Y while photo-curable ink is being discharged from the ink head  12  or no photo-curable ink is being discharged from the ink head  12  under control of the discharge controller  24 . In this case, the application controller  25  turns ON the UV lamps  17  so as to apply ultraviolet light to the photo-curable ink discharged onto the recording medium  2 . 
     As previously mentioned, the printer  1  alternately repeats the conveying operation and the printing operation so as to effect printing on the recording medium  2 . Suppose that the colored image  42  (see  FIG.  6   ) and the texture image  44  (see  FIG.  6   ) are to be formed on the recording medium  2  under control of the first discharge controller  241 . In this case, ink is discharged from at least the nozzles  13  of the first sub-head  121  and the second sub-head  122  located at corresponding positions in the sub-scanning direction X during a single printing operation (i.e., during a single movement of the carriage  10  in the first scanning direction or the second scanning direction along at least a portion of the movement path for the carriage  10  in the main scanning direction Y). Specifically, the colored ink CO is discharged from the nozzles  13  of the first sub-head  121 , and clear ink is discharged from the nozzles  13  of the second sub-head  122 . The colored ink CO and clear ink discharged from the nozzles  13  both hit a predetermined region on the recording medium  2 . As used herein, the term “predetermined region” refers to a common region onto which ink is dischargeable from both of the nozzles  13  of the first sub-head  121  and the nozzles  13  of the second sub-head  122  during a single movement of the carriage  10  in the first scanning direction or the second scanning direction. The application controller  25  turns ON the UV lamps  17  so as to apply ultraviolet light to the colored ink CO and clear ink that have hit the recording medium  2  and are yet to be cured. The ultraviolet light applied from the UV lamps  17  cures the colored ink CO and clear ink. 
     For example, suppose that the printer  1  including the ink head  12  illustrated in  FIG.  2    is used to discharge the colored ink CO and clear ink in this order onto a predetermined region during a single printing operation (or a single pass). In this case, the dots  31  (see  FIG.  7   ) of the colored ink CO are formed on the recording medium  2 , and the dots  32  (see  FIG.  7   ) of transparent ink are formed on the dots  31  of the colored ink CO. In contrast, suppose that clear ink and the colored ink CO are discharged in this order onto a predetermined region during a single printing operation (or a single pass). In this case, the dots  32  of transparent ink are formed on the recording medium  2 , and the dots  31  of the colored ink CO are formed on the dots  32  of transparent ink. The dots  31  and  32  are thus formed in layers on the predetermined region in the up-down direction Z (or the direction of thickness of the recording medium  2 ) such that the texture image  44  (see  FIG.  6   ) is formable. Consequently, the colored image  42  (see  FIG.  6   ) and the texture image  44  (see  FIG.  6   ) are formed on the recording medium  2 . 
     In the present preferred embodiment, the printer  1  effects “multi-pass printing” that involves effecting printing by moving the carriage  10  over a targeted one of the print regions on the recording medium  2  more than once. Referring now to  FIGS.  5 A to  5 C , the following description discusses how the printer  1  operates on the assumption that the printer  1  effects two-pass printing. In  FIGS.  5 A to  5 C , some of the nozzle rows  13 A are not illustrated for the sake of simplification of description. As illustrated in  FIGS.  5 A to  5 C , each nozzle row  13 A is divided into two nozzle sub-rows in the sub-scanning direction X, one of which is an upstream (or rear) nozzle sub-row  131  and the other one of which is a downstream (or front) nozzle sub-row  132 . In the present preferred embodiment, the carriage  10  is moved twice over the target print region on the recording medium  2 , assuming that a value (L1/2), which is obtained by dividing the length L 1  of each nozzle row  13 A by two (corresponding to the number of passes), is determined to be a single conveyance width for the recording medium  2 . 
       FIG.  5 A  illustrates a first round of the printing operation. As illustrated in  FIG.  5 A , the first round of the printing operation involves moving the carriage  10  in the second scanning direction (i.e., in the direction of an arrow S 1  indicating movement from right to left in  FIG.  5 A ), and discharging ink from the nozzle sub-rows  131  of the first sub-head  121  and the nozzle sub-rows  131  of the second sub-head  122 . Specifically, the first round of the printing operation involves discharging the colored ink CO onto a pass print region A 1  on the recording medium  2  from the nozzle sub-rows  131  of the first sub-head  121 , and discharging clear ink onto the pass print region A 1  from the nozzle sub-rows  131  of the second sub-head  122 . The first round of the printing operation further involves applying ultraviolet light from the UV lamps  17 . After the first round of the printing operation, the printer  1  performs a first round of the conveying operation involving conveying the recording medium  2  to the downstream side in the sub-scanning direction X by the conveyance width L1/2 as indicated by an arrow Fe. This conveying operation causes the pass print region A 1  to move to the downstream side relative to the nozzle sub-rows  131 . After the first round of the conveying operation, the printer  1  performs a second round of the printing operation. 
       FIG.  5 B  illustrates the second round of the printing operation. As illustrated in  FIG.  5 B , the second round of the printing operation involves moving the carriage  10  in the first scanning direction (i.e., in the direction of an arrow S 2  indicating movement from left to right in  FIG.  5 B ), and discharging ink from the nozzle sub-rows  131  and  132  of the first sub-head  121  and the nozzle sub-rows  131  and  132  of the second sub-head  122 . Specifically, the second round of the printing operation involves discharging the colored ink CO onto the pass print region A 1  on the recording medium  2  from the nozzle sub-rows  132  of the first sub-head  121 , and discharging clear ink onto the pass print region A 1  from the nozzle sub-rows  132  of the second sub-head  122 . The second round of the printing operation further involves applying ultraviolet light from the UV lamps  17 . Ink dots are thus formed in layers in the up-down direction Z on the pass print region A 1  such that the colored image  42  and the texture image  44  are formed thereon. The second round of the printing operation then involves discharging the colored ink CO onto a pass print region A 2  on the recording medium  2  from the nozzle sub-rows  131  of the first sub-head  121 , and discharging clear ink onto the pass print region A 2  from the nozzle sub-rows  131  of the second sub-head  122 . The second round of the printing operation further involves applying ultraviolet light from the UV lamps  17 . After the second round of the printing operation, the printer  1  performs a second round of the conveying operation, which is similar to the first round of the conveying operation, as indicated by the arrow Fe. This conveying operation causes the pass print region A 2  to move to the downstream side relative to the nozzle sub-rows  131 . After the second round of the conveying operation, the printer  1  performs a third round of the printing operation. 
       FIG.  5 C  illustrates the third round of the printing operation. As illustrated in  FIG.  5 C , the third round of the printing operation involves moving the carriage  10  in the second scanning direction (i.e., in the direction of the arrow S 1  indicating movement from right to left in  FIG.  5 C ), and discharging ink from the nozzle sub-rows  132  of the first sub-head  121  and the nozzle sub-rows  132  of the second sub-head  122 . Specifically, the third round of the printing operation involves discharging the colored ink CO onto the pass print region A 2  on the recording medium  2  from the nozzle sub-rows  132  of the first sub-head  121 , and discharging clear ink onto the pass print region A 2  from the nozzle sub-rows  132  of the second sub-head  122 . The third round of the printing operation further involves applying ultraviolet light from the UV lamps  17 . Ink dots are thus formed in layers in the up-down direction Z on the pass print region A 2  such that the colored image  42  and the texture image  44  are formed thereon. 
       FIG.  6    is a schematic plan view of the printed matter  40  provided by the printer  1 .  FIG.  7    is an enlarged cross-sectional view of a portion of the printed matter  40  illustrated in  FIG.  6   . The printed matter  40  illustrated in  FIG.  6    includes the recording medium  2 , the colored image  42 , and the texture image  44 . In the plan view, the colored image  42  and the texture image  44  are each exposed at a surface of the printed matter  40 . The texture image  44  is formed such that the texture image  44  overlaps with the colored image  42 . 
     As illustrated in  FIG.  6   , the texture image  44  is a pattern in which the pattern shapes  30  identical in shape are disposed regularly at the predetermined pitches P. In this preferred embodiment, the outer periphery of each pattern shape  30  is surrounded by the colored image  42 . The outer edge of each pattern shape  30  is in contact with the colored image  42 . The pattern shapes  30  each have a circular shape in the plan view. As illustrated in  FIG.  7   , the pattern shapes  30  each have a dome shape when viewed in cross section. In this preferred embodiment, the diameter ϕ of each pattern shape  30  may be about 0.1 mm, the height H of each pattern shape  30  may be about 0.05 mm, and each pitch P between the pattern shapes  30  adjacent to each other may be about 0.1 mm. 
     As illustrated in  FIG.  7   , each pattern shape  30  is an assemblage of ink dots. Specifically, each pattern shape  30  is an assemblage of one or more dots  31  of the colored ink CO and one or more dots  32  of clear ink. In this preferred embodiment, each pattern shape  30  includes more than one dot  31  of the colored ink CO and more than one dot  32  of clear ink. Lowermost ones of the dots  31  and  32  within each pattern shape  30  are in contact with the surface of the recording medium  2  (i.e., a surface of the recording medium  2  that faces the ink head  12 ). In the present preferred embodiment, the dots  31  and  32  are scattered in the main scanning direction Y and the up-down direction Z within each pattern shape  30 . The dots  31  and  32  are intermingled in the main scanning direction Y and the up-down direction Z within each pattern shape  30 . The dots  31  within each pattern shape  30  are arranged, for example, in the form of larger dots (or in the form of islands) located away from each other in the main scanning direction Y and/or the up-down direction Z, and the dots  32  within each pattern shape  30  are also arranged, for example, in the form of larger dots (or in the form of islands) located away from each other in the main scanning direction Y and/or the up-down direction Z. In one example, assuming that the dots  31  arranged in the form of islands (hereinafter referred to as “first dot islands”) and the dots  32  arranged in the form of islands (hereinafter referred to as “second dot islands”) are distributed within each pattern shape  30 , the second dot islands are located between the first dot islands. The dots  31  and  32  are distributed substantially uniformly within each pattern shape  30 . 
     As described above, the printer  1  is able to discharge the colored ink CO and clear ink during a single round of scanning so as to form the texture image  44  including the pattern shapes  30  on the recording medium  2 . Accordingly, the technique according to the present preferred embodiment is able to yield a higher throughput than, for example, the technique disclosed in JP 2011-161824 A. As illustrated in  FIGS.  2 ( a ) to  2 ( c )  of JP 2011-161824 A, the technique disclosed in JP 2011-161824 A requires performing a total of three steps in order to form images on predetermined regions B 1  and B 2 . The first step involves forming a colored image on the region B 1  by using colored ink (see  FIG.  2 ( a ) ). The second step involves forming an image on each of the two regions B 1  and B 2  (see  FIG.  2 ( b ) ). Specifically, the second step involves forming a colored image on the region B 2  by using colored ink, and forming an image on the region B 1  by using clear ink. The final step involves forming an image on the region B 2  by using clear ink (see  FIG.  2 ( c ) ). The technique according to the present preferred embodiment, however, is able to discharge the colored ink CO and clear ink simultaneously onto a target region. Thus, when the technique according to the present preferred embodiment is used to form images on the regions B 1  and B 2  illustrated in  FIGS.  2 ( a ) to  2 ( c )  of JP 2011-161824 A, it is only necessary to perform a total of two steps (one for the region B 1  and the other for the region B 2 ). Consequently, the technique according to the present preferred embodiment is able to yield a higher throughput and make printing time shorter than the technique disclosed in JP 2011-161824 A. 
     In the plan view (i.e., when the surface of the recording medium  2  is viewed), the dots  31  of the colored ink CO and the dots  32  of clear ink are scattered in each pattern shape  30 . The present preferred embodiment is thus able to reduce differences in gloss of the surface of the texture image  44 . The present preferred embodiment is able to reduce, for example, differences in gloss between a portion where the pattern shapes  30  of the texture image  44  are formed and a portion where the colored image  42  is exposed (e.g., a portion located on the right or left of each pattern shape  30  in  FIG.  7   ). Accordingly, the present preferred embodiment is able to increase the unity of the colored image  42  and the texture image  44 , which makes the user feel less strange about the appearance of the printed matter  40  and may enhance the beauty of the printed matter  40 . 
     Because photo-curable ink is cured relatively quickly on the recording medium  2 , the dots  31  and  32  are unlikely to mix with each other excessively to cause blurring of the colored ink CO and/or distortion of the colored image  42 . The amount of dots  31  of the colored ink CO to be provided per unit area of the recording medium  2  is decided in accordance with the colored ink print data irrelevant to the transparent ink print data. This uniformizes the absolute quantity of colorant per unit area of the recording medium  2  in a portion where the pattern shapes  30  of the texture image  44  are formed and a portion where the colored image  42  is exposed (e.g., a portion located on the right or left of each pattern shape  30  in  FIG.  7   ). Accordingly, the present preferred embodiment is able to reduce differences in color between the colored image  42  and the texture image  44  in the plan view (e.g., when the surface of the recording medium  2  is viewed). 
     The dots  32  of clear ink mixed into the pattern shapes  30  when viewed in cross section make the pattern shapes  30  more three-dimensional. Accordingly, the present preferred embodiment enables the printed matter  40  to provide a desired tactile sensation by selectively forming irregularities on desired portion(s) of the colored image  42  while reducing, for example, changes in the appearance of the colored image  42  (e.g., differences in color and/or reflectance of the surface of the colored image  42 ). The texture image  44  is preferably combined with the colored image  42  to such an extent that the texture image  44  is undistinguishable from the colored image  42  by a glance at the printed matter  40  and only recognizable when the printed matter  40  is touched. 
     In the present preferred embodiment, the controller  20  is configured or programmed to move the carriage  10  in the main scanning direction Y (i.e., the first direction) over a target region on the recording medium  2  more than once so as to form the texture image  44  in which the dots  31  of the colored ink CO and the dots  32  of transparent ink are mixed in the up-down direction Z (i.e., the direction of thickness of the texture image  44 ). If the colored ink head portions  12 C,  12 M,  12 Y,  12 K, and  12 W and the clear ink head portions  12 CL are disposed side by side in the main scanning direction Y as illustrated in  FIG.  2   , for example, moving the carriage  10  in the main scanning direction Y more than once (e.g., reciprocating the carriage  10  or moving the carriage  10  twice in the same direction) would enable two types of ink to be mixed in the direction of thickness of the texture image  44 . The present preferred embodiment is thus able to make the texture image  44  more three-dimensional while effectively reducing changes in the appearance of the printed matter  40 . For example, when the clear ink head portion(s) is/are disposed between the colored ink head portions or when the colored ink head portion(s) is/are disposed between the clear ink head portions, moving the carriage  10  in the main scanning direction Y just once enables two types of ink to be mixed in the direction of thickness of the texture image  44 . 
     In the present preferred embodiment, if the carriage  10   is moved over a target region on the recording medium  2  more than once, forming ink layers that satisfy similar conditions (e.g., forming similar images and/or similar irregularities) would achieve a higher throughput than layer printing. Specifically, layer printing requires performing two steps, i.e., the step of moving a carriage so as to form a colored image by using colored ink and the subsequent step of further moving the carriage so as to form an uneven image by using clear ink. In forming such two types of images, the present preferred embodiment requires just one step that involves moving the carriage  10  while simultaneously discharging colored ink and clear ink onto a target region. Consequently, the present preferred embodiment is able to yield a higher throughput than layer printing. 
     In the present preferred embodiment, the first discharge controller  241  is configured or programmed to control the ink head  12  such that photo-curable ink is discharged from the nozzles  13  included in regions of the first sub-head  121  (i.e., the nozzle rows  13 A of the head portions  12 C,  12 M,  12 Y,  12 K, and  12 W) and the second sub-head  122  (i.e., the nozzle rows  13 A of the head portions  12 CL) that are located at corresponding positions in the sub-scanning direction X. In one example, the regions of the first sub-head  121  and the second sub-head  122  located at corresponding positions in the sub-scanning direction X are each located along at least a portion of the length L 1 . Specifically, the regions of the first sub-head  121  and the second sub-head  122  located at corresponding positions in the sub-scanning direction X may each be located along an entirety of the length L 1  or a portion of the length L 1 . Accordingly, the present preferred embodiment is able to form the pattern shapes  30  stably and speedily, resulting in a further increase in printing throughput. 
     In the present preferred embodiment, the first discharge controller  241  is configured or programmed to control the ink head  12  such that the amount of photo-curable ink to be discharged from each of the nozzles  13  of the second sub-head  122  (i.e., each of the nozzles  13  in the nozzle rows  13 A of the head portions  12 CL) is larger than the amount of photo-curable ink to be discharged from each of the nozzles  13  of the first sub-head  121  (i.e., each of the nozzles  13  in the nozzle rows  13 A of the head portions  12 C,  12 M,  12 Y,  12 K, and  12 W). The present preferred embodiment is thus able to increase the proportion of the dots  32  of clear ink in each pattern shape  30  so as to make the texture image  44  more three-dimensional. Consequently, the present preferred embodiment is able to effectively enhance a tactile sensation when the printed matter  40  is touched. 
     In the present preferred embodiment, the head portions  12 C,  12 M,  12 Y, and  12 K each include the nozzle row  13 A (i.e., the first colored ink nozzle group) in which the nozzles  13  to discharge photo-curable ink of any one of process colors (i.e., the first color) are in alignment with each other in the sub-scanning direction X. The number of nozzle rows  13 A in the head portions  12 CL is larger than the number of nozzle rows  13 A (i.e., the number of first colored ink nozzle groups) included in each of the head portions  12 C,  12 M,  12 Y, and  12 K. The present preferred embodiment is thus able to increase the proportion of the dots  32  of clear ink in each pattern shape  30  so as to make the texture image  44  more three-dimensional. Consequently, the present preferred embodiment is able to effectively enhance a tactile sensation when the printed matter  40  is touched. 
     In the present preferred embodiment, the head portions of the ink head  12  each include the hollow case body  14  in which the nozzles  13  are defined, the pressure chamber  15  which is defined in the case body  14 , which is in communication with the nozzles  13 , and in which photo-curable ink is stored, the diaphragm  14 V disposed inside the case body  14  and defining a portion of the pressure chamber  15 , and the actuator  16  (which is a piezoelectric element) connected to the diaphragm  14 V and configured to, upon receiving a driving pulse, cause the pressure chamber  15  to expand or contract. The first discharge controller  241  includes the storage  26  storing the first driving pulse to cause each of the nozzles  13  to discharge photo-curable ink by the first discharge amount, and the second driving pulse to cause each of the nozzles  13  to discharge photo-curable ink by the second discharge amount larger than the first discharge amount. The first discharge controller  241  is configured or programmed to supply the first driving pulse to the first sub-head  121  (i.e., the nozzle rows  13 A of the head portions  12 C,  12 M,  12 Y,  12 K, and  12 W) and supply the second driving pulse to the second sub-head  122  (i.e., the nozzle rows  13 A of the head portions  12 CL). The present preferred embodiment is thus able to increase the proportion of the dots  32  of clear ink in each pattern shape  30  so as to make the texture image  44  more three-dimensional. Consequently, the present preferred embodiment is able to effectively enhance a tactile sensation when the printed matter  40  is touched. 
     The preferred embodiments of the present invention have been described thus far. The preferred embodiments described above, however, are merely illustrative. The present invention may be embodied in various other forms. 
     In the foregoing preferred embodiments, the texture image  44  is a regular pattern including the pattern shapes  30  disposed at the predetermined pitches P in a scattered manner. Alternatively, the texture image  44  may be any other suitable pattern.  FIG.  8 A  is a plan view of a variation of the texture image  44  (which will hereinafter be referred to as a “texture image  44 X”).  FIG.  8 B  is a cross-sectional view of a portion of the texture image  44 X illustrated in  FIG.  8 A . The texture image  44 X illustrated in  FIG.  8 A  includes pattern shapes  30 X, six of which are not continuous with each other, four of which are continuous with each other in such a manner as to form a mountain range shape, and the remaining two of which are also continuous with each other in such a manner as to form a mountain range shape. Alternatively, any other number of pattern shapes  30 X may be continuous with each other in such a manner as to form a mountain range shape, or all of the pattern shapes  30 X may be continuous with each other in such a manner as to form a mountain range shape. The texture image  44 X  includes the pattern shapes  30 X and connectors  33 X connecting the pattern shapes  30 X adjacent to each other. In this example, the surfaces of the connectors  33 X have less irregularity than the surfaces of the pattern shapes  30 X. 
     In the foregoing preferred embodiments, the pattern shapes  30  included in the texture image  44  each have a circular shape in a plan view and each have a dome shape when viewed in cross section. Alternatively, the pattern shapes  30  may each have any other suitable shape.  FIG.  9 A  is a plan view of a variation of the pattern shape  30  (which will hereinafter be referred to as a “pattern shape  30 A”).  FIG.  9 B  is a cross-sectional view of the pattern shape  30 A illustrated in  FIG.  9 A . The pattern shape  30 A illustrated in  FIGS.  9 A and  9 B  has a quadrangular pyramid shape. The pattern shape  30 A has a quadrangular shape in the plan view and has a triangular shape whose center is protruding upward when viewed in cross section.  FIG.  10 A  is a plan view of another variation of the pattern shape  30  (which will hereinafter be referred to as a “pattern shape  30 B”).  FIG.  10 B  is a cross-sectional view of the pattern shape  30 B illustrated in  FIG.  10 A . The pattern shape  30 B illustrated in  FIGS.  10 A and  10 B  has a pentagonal pyramid shape. The pattern shape  30 B has a pentagonal shape in the plan view and has a triangular shape whose center is protruding upward when viewed in cross section.  FIG.  11 A  is a plan view of still another variation of the pattern shape  30  (which will hereinafter be referred to as a “pattern shape  30 C”).  FIG.  11 B  is a cross-sectional view of the pattern shape  30 C illustrated in  FIG.  11 A . The pattern shape  30 C illustrated in  FIGS.  11 A and  11 B  has a triangular pyramid shape. The pattern shape  30 C has a triangular shape in the plan view and has a triangular shape whose center is protruding upward when viewed in cross section.  FIG.  12 A  is a plan view of yet another variation of the pattern shape  30  (which will hereinafter be referred to as a “pattern shape  30 D”) .  FIG.  12 B  is a cross-sectional view of the pattern shape  30 D illustrated in  FIG.  12 A . The pattern shape  30 D has a circular shape in the plan view and has a bowl shape whose center is recessed when viewed in cross section. 
     In the foregoing preferred embodiments, the dots  31  and  32  included in each pattern shape  30  are illustrated as having identical dimensions. The dots  31  and  32  included in each pattern shape  30 , however, do not necessarily have to have identical dimensions. Alternatively, each pattern shape  30  may include dots having different dimensions. In one example, each pattern shape  30  may include at least two of a small dot, a medium dot, and a large dot. Suppose that when viewed in cross section, each pattern shape  30  is divided into two portions (e.g., an upper portion located adjacent to the surface of the pattern shape  30  and a lower portion located adjacent to the recording medium  2 ) in the direction of thickness of the pattern shape  30 . In this case, the average dimensions of dots included in the upper portion may be different from the average dimensions of dots included in the lower portion. In each pattern shape  30  having a dome shape when viewed in cross section as illustrated in  FIG.  7   , for example, the number of small dots included in the upper portion of each pattern shape  30  may be larger than the number of small dots included in the lower portion of each pattern shape  30 , and/or the number of large dots included in the lower portion of each pattern shape  30  may be larger than the number of large dots included in the upper portion of each pattern shape  30 . In the texture image  44 X having a mountain range shape when viewed in cross section as illustrated in  FIG.  8 B , the average dimensions of dots in each pattern shape  30 X may be different from the average dimensions of dots in each connector  33 X. 
     In the foregoing preferred embodiments, the printer  1  effects two-pass printing. Alternatively, the printer  1  may effect any other suitable type of printing. The printer  1  may effect, for example, four-pass printing, eight-pass printing, or sixteen-pass printing. 
     In the foregoing preferred embodiments, the nozzle rows  13 A of the head portions  12 C,  12 M,  12 Y,  12 K,  12 W, and  12 CL have identical lengths (or each have the length L 1 ) in the sub-scanning direction X. Alternatively, the nozzle rows  13 A of the head portions  12 C,  12 M,  12 Y,  12 K,  12 W, and  12 CL may have different lengths in the sub-scanning direction X. In one example, some or all of the nozzle rows  13 A of the head portions  12 C,  12 M,  12 Y,  12 K, and  12 W may be different in length in the sub-scanning direction X. In another example, the nozzle rows  13 A of the head portions  12 C,  12 M,  12 Y,  12 K, and  12 W may be different in length from the nozzle rows  13 A of the head portions  12 CL. In still another example, at least one of the nozzle rows  13 A of the head portions  12 CL may be longer in length than the nozzle rows  13 A of the head portions  12 C,  12 M,  12 Y,  12 K, and  12 W. 
     In the foregoing preferred embodiments, the carriage  10  moves in the main scanning direction Y, and the recording medium  2  moves in the sub-scanning direction X. Alternatively, the carriage  10  and the recording medium  2  may move in any other suitable directions. Because the carriage  10  and the recording medium  2  are required to move relative to each other, either one of the carriage  10  and the recording medium  2  may move in the main scanning direction Y or the sub-scanning direction X. In one example, the recording medium  2  may be placed so as to be immovable, and the carriage  10  may be able to move in both of the main scanning direction Y and the sub-scanning direction X. In another example, both of the carriage  10  and the recording medium  2  may be able to move in both of the main scanning direction Y and the sub-scanning direction X. 
     In the foregoing preferred embodiments, the printer  1  has been described as being a “shuttle printer” or a “serial printer” that includes the ink head  12  mounted on the carriage  10  and effects printing while the ink head  12  reciprocates (or shuttles) in the main scanning direction Y. Alternatively, the printer  1  may be any other suitable type of printer. The techniques disclosed herein are similarly usable for a “line printer” that includes, for example, a line head similar in width to the recording medium  2  and effects printing, with the line head being fixed. 
     The techniques disclosed herein are usable for various types of inkjet printers. The techniques disclosed herein are usable not only for the “roll-to-roll” printer  1  that conveys the recording medium  2  in a roll form as illustrated in the foregoing preferred embodiments but also for a flatbed printer. The printer  1  does not necessarily have to be used solely as an independent printer but may be used in combination with other apparatus(es). The printer  1  may include, for example, a cutting apparatus or may be incorporated into other apparatus(es). 
     The terms and expressions used herein are for description only and are not to be interpreted in a limited sense. These terms and expressions should be recognized as not excluding any equivalents to the elements shown and described herein and as allowing any modification encompassed in the scope of the claims. The present invention may be embodied in many various forms. This disclosure should be regarded as providing preferred embodiments of the principles of the present invention. These preferred embodiments are provided with the understanding that they are not intended to limit the present invention to the preferred embodiments described in the specification and/or shown in the drawings. The present invention is not limited to the preferred embodiments described herein. The present invention encompasses any of preferred embodiments including equivalent elements, modifications, deletions, combinations, improvements and/or alterations which can be recognized by a person of ordinary skill in the art based on the disclosure. The elements of each claim should be interpreted broadly based on the terms used in the claim, and should not be limited to any of the preferred embodiments described in this specification or referred to during the prosecution of the present application. 
     While preferred embodiments of the present invention have been described above, it is to be understood that variations and modifications will be apparent to those skilled in the art without departing from the scope and spirit of the present invention. The scope of the present invention, therefore, is to be determined solely by the following claims.