Patent Grant
11787204
The present application claims priority from Japanese Patent Application No. 2021-077411 filed on Apr. 30, 2021, the disclosure of which is incorporated herein by reference in its entirety.
The present specification relates to a controller of a printing part provided with a printing head which has a plurality of nozzles and a conveyor which is configured to convey a medium in a conveying direction relative to the printing head.
In a case that a publicly known printer performs printing with a pass processing a plurality of times (a plurality of pass processings), the publicly known printer performs, by two pass processings, the printing of a partial area in the vicinity of a boundary between band areas each of which is printed by one of the pass processings. With this, the publicly known printer suppress such a situation that a banding becomes conspicuous in the vicinity of the boundary between the band areas. This printer is provided with a pressing member arranged on the upstream side in the conveying direction with respect to the plurality of nozzles of the printing head and configured to press the sheet from a side of a print surface.
The present specification discloses a technique of improving the image quality of a print image by a printing part provided with a facing member capable of facing a print surface of a sheet (for example, the pressing member as described above).
The technique disclosed in the present specification can be realized as an example of an aspect as follows.
According to an aspect of the present disclosure, there is provided a printer including: a printing part and a controller. The printing part includes: a conveyor configured to convey a medium in a conveying direction; a printing head having a plurality of nozzles from which an ink of a specified color is discharged and of which positions in the conveying direction are mutually different, the printing head being configured to discharge the ink from the plurality of nozzles to the medium so as to form dots in the medium, and a facing member configured to be capable of facing a print surface of the medium on an upstream side in the conveying direction with respect to the plurality of nozzles of the printing head. The controller is configured to cause the printing part to execute a partial printing of forming the dots by the printing head and a conveyance of the medium by the conveyor alternately and a plurality of times to thereby cause the printing part to print a print image. In a case that the controller causes the printing part to print the print image, the controller is configured to execute: causing the printing head to execute a first partial printing not less than one time, the first partial printing being the partial printing executed in a state that the medium faces the facing member, causing the conveyor to convey the medium by a first conveying amount, after causing the printing head to execute the first partial print not less than one time, causing the printing head to execute a second partial printing not less than one time, after causing the conveyor to convey the medium by the first conveying amount, the second partial printing being the partial printing executed in the state that the medium faces the facing member, causing the conveyor to convey the medium by a second conveying amount, which is smaller than the first conveying amount, after causing the printing head to execute the second partial print not less than one time, causing the printing head to execute a third partial printing not less than one time, after causing the conveyor to convey the medium by the second conveying amount, the third partial printing being the partial printing executed in a state that the medium is positioned at a specified position in the conveying direction at which a predetermined position, of an end part on the upstream side in the conveying direction of the medium, faces the facing member, causing the conveyor to convey the medium, after causing the printing head to execute the third partial printing not less than one time, and then, causing the printing head to execute a fourth partial printing not less than one time, the fourth partial printing being the partial printing executed in a state that the medium does not face the facing member. A first area printed by the first partial printing includes a first normal area which is printed only by the first partial printing, and a first end area which is positioned on the upstream side in the conveying direction with respect to the first normal area and which is printed by both of the first partial printing and the second partial printing. A second area printed by the second partial printing includes the first end area, a second normal area which is positioned on the upstream side in the conveying direction with respect to the first end area and which is printed only by the second partial printing, and a second end area which is positioned on the upstream side in the conveying direction with respect to the second normal area and which is printed by both of the second partial printing and the third partial printing. A third area printed by the third partial printing includes the second end area and a third end area which is positioned on the upstream side in the conveying direction with respect to the second end area and which is printed by both of the third partial printing and the fourth partial printing. A fourth area printed by the fourth partial printing includes the third end area and a fourth normal area which is positioned on the upstream side in the conveying direction with respect to the third end area and which is printed only by the fourth partial printing. The controller is configured to execute: determining the second conveying amount to be a target conveying amount which is a conveying amount for conveying the medium from a position thereof, at a time of completion of the second partial printing, to the specified position, in a case that the target conveying amount is not less than a reference, and determining the second conveying amount to be a corrected conveying amount which is greater than the target conveying amount, in a case that the target conveying amount is smaller than the reference, to thereby shift the specified position.
According to the above-described configuration, the third partial printing is performed in the state that the medium is positioned at the specified position, namely, in the state that the predetermined position of the end part on the upstream side in the conveying direction of the medium faces the facing member. Thus, it is possible to perform the third partial printing in a state that the medium is stable (stabilized), thereby making it possible to improve the print quality. Here, in a case that the target conveying amount which is the conveying amount for conveying the medium from the position thereof, at a time of completion of the second partial printing, to the specified position is excessively small, the length in the conveying direction of the third area which is (to be) printed by the third partial printing becomes to be excessively small. In this case, there is such a possibility that the length in the conveying direction of the second end area which is printed by both of the second partial printing and the third partial printing and/or the length in the conveying direction of the third end area which is printed by both of the third partial printing and the fourth partial printing might not be secured. According to the above-described configuration, in a case that the target conveying amount is not less than the reference, the second conveying amount is determined to be the target conveying amount, and in a case that the target conveying amount is smaller than the reference, the second conveying amount is made to be the corrected conveying amount greater than the target conveying amount to thereby shift the specified position. As a result, it is possible to suppress such a situation that the length in the conveying direction of the third area printed by the third partial printing becomes to be excessively small. Accordingly, since such an inconvenience that the length in the conveying direction of the second end area and/or the length in the conveying direction of the third end area is/are not be secured can be suppressed, it is possible to suppress the occurrence of such a situation that the banding is conspicuous. As described above, according to the above-described configuration, it is possible to improve the image quality of the print image by the printing part.
Note that the technique disclosed in the present specification can be realized in a various kinds of aspects; for example, the technique can be realized in aspects including: a printer; a method of controlling the printing part, a printing method: a computer program configured to realize the functions of these apparatuses and methods; a non-transitory, computer-readable medium storing the computer program therein; etc.
<A-1: Configuration of Printer 200>
A first embodiment of the present disclosure will be explained.
A printer 200 includes, for example, a printing mechanism 100 as a printing part, a CPU 210 as a controller, a non-volatile memory 220 such as a hard disk drive, etc., a volatile memory 230 such as a RAM, etc., an operating part 260 such as a button, a touch panel, etc., via which an operation from a user is obtained, a displaying part 270 such as a liquid crystal display, etc., and a communicating part 280. The communicating part 280 includes a wired or wireless interface configured to be connected to a network NW. The printer 200 is connected to an external apparatus, such as, for example, a terminal apparatus 300 of a user, via the communicating part 280 so that the printer 200 can communicate with the external apparatus 300.
The volatile memory 230 provides a buffer area 231 which temporarily stores various kinds of intermediate data generated in a case that the CPU 210 performs a processing. A computer program PG is stored in the non-volatile memory 220. In the present embodiment, the computer program PG is a control program for controlling the printer 200. The computer program PG may be provided by being stored in the non-volatile memory 220 at a time of shipment of the printer 200. Alternatively, the computer program PG may be provided in an aspect in which the computer program PG is downloaded from a server. Still alternatively, the computer program PG may be provided in an aspect in which the computer program PG is stored in a DVD-ROM, etc. The CPU 210 executes the computer program PG so as to, for example, control the printing mechanism 100, thereby executing a printing processing (to be described later on). With this, the CPU 210 prints an image on a medium (for example, paper sheet, sheet) by controlling the printing mechanism 100.
The printing mechanism 100 is capable of forming dots on a sheet (paper sheet) M by using inks (liquid droplets) of respective colors which are cyan (C), magenta (M), yellow (Y), and black (K) to thereby perform color printing. The printing mechanism 100 includes a printing head 110, a head driving part 120, a main-scanning part 130, and a conveyor 140.
As depicted in
The conveyor 140 conveys the sheet M in a conveying direction AR (+Y direction in
The upstream roller pair 142 holds the sheet M on the upstream side (−Y side) with respect to the printing head 110, and the downstream roller pair 141 holds the sheet M on the downstream side (+Y side) with respect to the printing head 110. The sheet table 145 is arranged at a location which is between the upstream roller pair 142 and the downstream roller pair 141 and at which the sheet table 145 faces or is opposite to a nozzle formation surface 1 of the printing head 110. The downstream roller pair 141 and the upstream roller pair 142 are driven by a conveyance motor (not depicted in the drawings) to thereby convey the sheet M in the conveying direction AR.
The head driving part 120 (
The positions in the main-scanning direction (X direction in
The conveyor 140 will be further explained, with reference to
The flat plate BB is a plate member which is substantially parallel to the main-scanning direction (X direction) and the conveying direction (+Y direction). An end on the upstream side (−Y side) of the flat plate BB is positioned in the vicinity of the upstream roller pair 142. An end on the downstream side (+Y side) of the flat plate BB is positioned in the vicinity of the downstream roller pair 141.
As depicted in
The plurality of pressing members 146 are arranged in positions on the +Z side of the plurality of low supporting members LP. Positions in the X direction of the plurality of pressing members 146 are same as the positions in the X direction of the plurality of low supporting members LP. Namely, the position in the X direction of each of the plurality of pressing members 146 is between two high supporting members HP, among the plurality of high supporting members HP, which are adjacent to each of the plurality of pressing members 146. Each of the plurality of pressing members 146 is a plate member which is inclined closer to one of the plurality of low supporting members LP further toward the +Y direction. The positions in the Y direction of the plurality of pressing members 146 are on the upstream side (−Y side) with respect to the printing head 110, and on the downstream side (+Y side) with respect to the upstream roller pair 142.
As depicted in
Note that in a state that the end on the upstream side (an end on the −Y side) of the sheet M which is being conveyed is located on the upstream side (the −Y side) with respect to a position Ys in
<A-2: Printing Processing>
The CPU 210 (
In the processing of step S120, the CPU 210 executes a rasterization processing with respect to the obtained image data to thereby generate RGB image data. The RGB image data is thus obtained as object image data of the present embodiment. The RGB image data is bitmap data in which a RGB value is included for each of pixels. The RGB value is, for example, a color value of a RGB color system which includes three component values that are red (R), green (G), and blue (B).
In the processing of step S130, the CPU 210 converts the RGB image data to print data. Specifically, the CPU 210 executes a color conversion processing and a half tone processing with respect to the RGB image data. The color conversion processing is a processing of converting the RGB values of a plurality of pixels included in the RGB image data to CMYK values, respectively. The CMYK values are color values of the CMYK color system including component values corresponding to the ink(s) which is (are) to be used in the printing (in the present embodiment, the component values of C, M, Y and K). The color conversion processing is executed, for example, by referring to a publicly known look-up table defining the corresponding relationship between the RGB values and the CYMK values. The halftone processing is a processing of converting the image data for which the color conversion processing has been executed to print data (also referred to as “dot data”). The print data is data indicating a dot formation state for each of the pixels, with respect to each of the respective color components of CMYK. The value of each of the pixels in the dot data indicates, for example, a dot formation state of two gradations which are “no dot” and “with dot”, or a dot formation state of four gradations which are “no dot”, “small dot”, “medium dot”, and “large dot”. The halftone processing is executed by using a publicly known method such as the dithering method, the error diffusion method, etc.
The CPU 210 executes, in the processing of step S140, a print data outputting processing. The print data outputting processing is a processing in which partial print data is generated per one time of a partial printing (to be described later on), a variety of control data is added to the partial print data, and then the partial print data is outputted to the printing mechanism 100. The control data includes data designating a conveying amount TL of sheet conveyance to be executed before the partial printing. In the print data outputting processing, the partial print data is output corresponding to a number of time(s) by which the partial printing is to be executed. The details of the print data outputting processing will be explained later on.
With this, the CPU 210 is capable of causing the printing mechanism 100 to perform printing of a print image PI. Specifically, the CPU 210 controls the head driving part 120, the main-scanning part 130, and the conveyor 140 to alternately execute the partial printing and the sheet conveyance repeatedly a plurality of times to thereby perform the printing. In one time of the partial printing (one partial printing), in a state that the sheet M is stopped on the sheet table 145, an ink(s) is (are) discharged or ejected from the nozzles NZ of the printing head 100 to the sheet M while performing one time of the main scanning (one main scanning), thereby printing a part of the image to be printed on the sheet M. One time of the sheet conveyance is a conveyance in which the sheet M is conveyed in the conveyance direction AR by an amount corresponding to the conveying amount TL which is determined in the print data outputting processing.
Further,
In each of the head positions P0 to P4, a hatched range is a range in which a nozzle(s) NZ (also referred to as “used nozzle(s)”) to be used for printing in a partial printing to be executed at each of the head positions P0 to P4 is/are positioned in each of the head positions P0 to P4. The used nozzle(s) is/are a part or entirety of the usable nozzles (in the present embodiment, all the nozzles corresponding to the nozzle length D). In the example depicted in
In
Each of the normal areas is an area in which each of the respective raster lines within the area is printed only by one time of partial printing (partial printing performed once). For example, in each of the raster lines in a normal area NAk (“k” being an integer in a range of 0 to 4) in
Each of the end areas is an area in which each of the respective raster lines within the area is printed by two times of partial printing (partial printing performed twice). For example, in each of the raster lines in an end area SAI (“I” being an integer in a range of 0 to 3) in
A length Ha (see
The reason for providing the end areas is explained below. It is assumed that a print image is formed only by images printed in the normal areas, without providing the end areas. In this case, an inconvenience which is referred to as a so-called banding such as a white streak and/or a black streak appearing at a boundary between two normal areas adjacent to each other in the conveying direction AR might be caused, due to any variation in the conveying amount of the sheet M, etc. The banding lowers the image quality of the print image PI. By providing the end area between two pieces of the normal area and by printing the image on the end area, it is possible to suppress the occurrence of the inconvenience referred to as the banding as described above. Since the dots on one raster line in the end area are formed by the partial printing performed twice, it is possible to suppress such a situation that all the dots on a certain one raster line are deviated uniformly with respect to all the dots on another raster line different from the certain raster line.
In the present embodiment, a partial printing(s) which is (are) included in the plurality of partial printings and which is (are) different from the last partial printing is (are) performed in the state that the sheet M is pressed by the plurality of pressing members 146, namely, in the state that the print surface of the sheet M faces the pressing members 146. The last partial printing is performed in the state that the sheet M is not pressed by the plurality of pressing members 146. In the present embodiment, in order that the printing is performed, as much as possible, in a state that the sheet M is pressed by the plurality of pressing members 146, a print processing which is immediately before the last partial printing (which is first from the last partial printing, penultimate partial printing) is performed in a state that a specified position SP in the vicinity of the upstream end of the sheet M is pressed by the pressing members 146. As depicted in
<A-3: Print Data Outputting Processing>
Next, the print data outputting processing in the processing of step S140 of
The print data generated in the processing of step S130 of
In the processing of step S200, the CPU 210 obtains raster data (hereinafter referred also to as “interest raster data”), among the plurality of pieces of raster data, which corresponds to one interest raster line. The interest raster line is included in the print image PI, and is selected sequentially one by one, from the downstream side in the conveyance direction AR at the time of printing (+Y side in
Here, a partial printing by which the interest raster line is printed is also referred to as an interest partial printing. Note that, however, in a case that the interest raster line is to be printed by two times of the partial printing, namely, in a case that the interest raster line is positioned within an end area, a partial printing included in the two times of the partial printing and which is executed first is defined as the interest partial printing. For example, in a case that the raster lines RL1 and RL2 in
In the processing of step S205, the CPU 210 judges as to whether or not the interest raster data is an object of division. In a case that the interest raster line is positioned within an end area, in other words, in a case that the interest nozzle is a predetermined piece (in the present embodiment, 6 pieces) of nozzle NZ which are included in the usable nozzles and which are positioned at an end on the upstream side, the interest raster data is judged to be the object of division. In a case that the interest raster line is positioned within a normal area, the interest raster data is judged not to be the object of division.
In a case that the interest raster data is not the object of division (step S205: NO), namely, in a case that the interest raster line is positioned within the normal area, the CPU 210 allocates, in the processing of step S210, the interest raster data to the interest nozzle. The interest nozzle at the time of starting the print data outputting processing is a nozzle NZ located at the downstream end among the usable nozzles.
In a case that the interest raster data is the object of division (step S205: YES), namely, in a case that the interest raster line is positioned within the end area, the CPU 210 divides, in the processing of step S215, the interest raster data into data for the interest partial printing and data for a partial printing which is to be performed next to the interest partial printing (next partial printing).
Specifically, the CPU 210 obtains division pattern data PD corresponding to the interest raster line.
Here, the recording ratios R0, R1 and R2 in
In a range in the conveyance direction AR corresponding to the end area SA0, the recording ratio R0 is linearly reduced toward the upstream side (the lower side in
The division pattern data PD is generated so that the above-described recording ratios are realized depending on the position in the conveyance direction AR of the interest raster line in the end area. The CPU 210 divides, according to the division pattern data PD, the interest raster data into the data for the interest partial printing and the data for the next partial printing.
In the processing of step S220, the CPU 210 allocates the data for the interest partial printing to the interest nozzle. In the processing of step S225, the CPU 210 allocates the data for the next partial printing to a nozzle corresponding to the next partial printing (corresponding nozzle). Here, the corresponding nozzle is a nozzle NZ to be used for forming the dots on the interest raster line in the next partial printing. The corresponding nozzle at a time of starting the print data outputting processing is a nozzle NZ on the downstream end of the usable nozzles. For example, in a case that the raster line RL2 in
In the processing of step S230, the CPU 210 updates a number indicating the corresponding nozzle of the next partial printing. Namely, the CPU 210 changes the number indicating the corresponding nozzle to a number indicating a nozzle NZ which is on the upstream side, only by one, with respect to the current corresponding nozzle.
In the processing of step S235, the CPU 210 updates a number indicating the interest nozzle. Namely, the CPU 210 changes the number indicating the interest nozzle to a number indicating a nozzle NZ which in on the upstream side, only by one, with respect to the current interest nozzle.
In the processing of step S240, the CPU 210 judges as to whether or not the raster data is allocated to all the used nozzles in the interest partial printing. Specifically, in a case that the number indicating the interest nozzle after the update exceeds the number indicating a nozzle which is on the upstream-most side among the used nozzles, the CPU 210 judges that the raster data has been allocated to all the used nozzles. In a case that there is a used nozzle to which the raster data has not been allocated (step S240: NO), the CPU 210 returns to step S200.
In a case that the raster data has been allocated to all of the used nozzles (step S240: YES), the CPU 240 outputs, in the processing of step S245, partial print data for the interest partial printing, and conveying amount data to the printing mechanism 100. The partial print data is a raster data group allocated to the used nozzles. The conveying amount data is control data indicating the conveying amount TL. In a case that the interest partial printing is a foremost partial printing, which is the partial printing performed first or foremost, the conveying amount TL is determined such that a position, on the sheet M, at which the downstream end of the print image PI is to be printed, and a position of a nozzle NZ which is located on the downstream end among the used nozzles are coincident with each other. In a case that the interest partial printing is a second partial printing, the conveying amount TL is a value obtained by deducting a number (quantity) of nozzle(s) corresponding to the end area from the number (quantity) of the usable nozzles. In the present embodiment, since the number (quantity) of the usable nozzles is the nozzle length D and the number of the nozzle(s) corresponding to the end area is the length Ha in the conveying direction AR of the end area, the conveying amount TL determined in a case that the interest partial printing is the second partial printing is TL=(D−Ha). This conveying amount is previously determined on a premise that the head position of the second partial printing will not become to be the end-pressing head position. In a case that the interest partial printing is the third partial printing and thereafter, the conveying amount TL is determined in the processing of step S280 which will be described later on. In a case that the printing mechanism 100 receives the partial print data and the conveying amount data, the printing mechanism 100 executes the sheet conveyance by an amount corresponding to the conveying amount TL indicated by the conveying amount data, and then executes the partial printing by using the partial print data.
In the processing of step S250, the CPU 210 judges as to whether or not all of the partial print data has been outputted. In a case that all of the partial print data has been outputted (step S250: YES), the CPU 210 ends the print data outputting processing. In a case that all of the partial print data has not been outputted (step S250: NO), the CPU 210 updates the interest partial printing in the processing of step S251. Namely, the CPU 210 makes the interest partial printing to be a next partial printing next to the current interest partial printing. Specifically, the number indicating the corresponding nozzle of the next interest partial printing at the current point of time is set newly to be the number indicating the interest nozzle. The number indicating the corresponding nozzle of the next interest partial printing at the current point of time is made to be a number indicating a nozzle on the downstream end in the normal area. For this reason, the number indicating a new interest nozzle is set to be the number indicating a nozzle on the downstream end in the normal area.
In the processing of step S252, the CPU 210 judges as to whether or not the interest partial printing is a partial printing which is to be executed at the end-pressing head position. In the example of
In the processing of step S255, the CPU 210 calculates an excess amount VO of a pressing reference position RL at the interest partial printing. The excess amount VO indicates a length from the pressing reference position RL to an upstream-most nozzle NZ which is a nozzle NZ on the upstream-most side among the usable nozzle at the head position in the interest partial printing, in a case that the upstream-most nozzle NZ is positioned on the upstream side with respect to the pressing reference position RL. The pressing reference position RL (
In a case that the upstream-most nozzle is same as the pressing reference position RL, or that the upstream-most nozzle is positioned at the downstream side with respect to the pressing reference position RL, the excess amount VO is 0 (zero). In the example of
In the processings of steps S260 to S270, the CPU 210 sets a nozzle shift amount NS of a partial printing to be performed next to the interest partial printing (next partial printing), based on the excess amount VO. The nozzle shift amount NS indicates a number (quantity) of nozzle(s) NZ which is included in the usable nozzles and which is not used on the downstream side (also referred to as a “downstream-side non-used nozzle”) in the next partial printing to be performed next to the interest partial printing. In a case that the nozzle shift amount NS is 0 (zero), the downstream-side non-used nozzle is not provided or set. In a case that the nozzle shift amount NS is not less than 1 (one), a nozzle(s) NZ on the downstream side (+Y side in
In the processing of step S260, the CPU 210 judges as to whether or not the excess amount VO is greater than an upper limit value NSmax of the nozzle shift amount NS. The upper limit value NSmax is a value obtained by deducting two times the number (quantity) of nozzle(s) corresponding to the end area from the number of the usable nozzles. In the present embodiment, since the number (quantity) of the usable nozzles is the nozzle length D and the number (quantity) of the nozzle(s) corresponding to the end area is Ha, the upper limit value NSmax is (D−2×Ha). In other words, the upper limit value NSmax is determined so that the length in the conveying direction AR of an area printed by one time of the partial printing (for example, the area RA3) becomes to be at least not less than two times the length in the conveying direction AR of the end area.
In a case that the nozzle shift amount NS is not more than the upper limit value NSmax (step S260: NO), the CPU 210 sets, in the processing of step S265, the nozzle shift amount NS to be the excess amount VO. In a case that the nozzle shift amount NS is greater than the upper limit value NSmax (step S260: YES), the CPU 210 sets, in the processing of step S270, the nozzle shift amount NS to be the upper limit value NSmax.
In a case that the interest partial printing is the partial printing to be executed at the end part-pressing head position (step S252: YES), the CPU 210 sets, in the processing of step S272, the nozzle shift amount NS to be 0 (zero). In the case that the interest partial printing is the partial printing which is to be executed at the end part-pressing head position, the next partial printing becomes to be the last partial printing. The reason for this is that, in the last partial printing, the non-used nozzle is not set for the downstream end of the usable nozzle.
In the processing of step S280, the CPU 210 determines, based on the nozzle shift amount NS, the conveying amount TL of the sheet conveyance to be performed after the interest partial printing. The conveying amount TL is calculated with the number (quantity) of the nozzle(s) as the unit. The conveying amount TL is a value obtained by deducting the number (quantity) of the nozzle(s) in the end area and the nozzle shift amount NS from the number (quantity) of the usable nozzles. In the present embodiment, since the number (quantity) of the usable nozzles is the nozzle length D and the number (quantity) of the nozzle(s) corresponding to the end area is the length Ha in the conveying direction AR of the end area, the conveying amount TL is TL=(D−Ha−NS).
Here, as described above, the upper limit value NSmax is set with respect to the nozzle shift amount NS, and in a case that the excess amount VO is not more than the upper limit value NSmax, the nozzle shift amount NS is set to be the excess amount VO; in a case that the excess amount VO is smaller than the upper limit value NSmax, the nozzle shift amount NS is set to be the upper limit value NSmax. Accordingly, in a case that the excess amount VO is not more than the upper limit value NSmax, the conveying amount TL is set to be a value which becomes to be smaller as the excess amount VO is greater (D−Ha−VO); whereas in a case that the excess amount VO is greater than the upper limit value NSmax, the conveying amount TL is set to be a predetermined lower limit value (D−Ha−NSmax)=TLmin. Further, since NSmax=(D−2×Ha), the lower limit value TLmin is Ha. Namely, in the present embodiment, the lower limit value TLmin of the conveying amount TL is set to be the length Ha in the conveying direction AR of the end area (the unit is the number (quantity) of the nozzle(s), the number (quantity) of the raster line(s)) (TLmin=Ha).
In such a manner, the processings in steps S255 to S270 in
In the processing of step S285, the CPU 210 sets the number indicating the corresponding nozzle of the partial printing next to the interest partial printing to be an initial value. The initial value is a number indicating a nozzle which is included in the usable nozzles and which is positioned on the upstream side, by an amount corresponding to the nozzle shift amount NS, from the downstream end. After the processing of step S285, the CPU 210 returns the processing to step S200.
The printing of the present embodiment, as explained above, will be further explained with reference to
The head position P3 which is the end-pressing head position is a position in the conveying direction AR which is fixed with respect to the sheet M. Therefore, the nozzle shift amount NS of the partial printing to be executed at the head position P3 is set depending on the position in the conveying direction AR of the head position P2 (steps S260 to S270 of
In the example of
Here, the position in the conveying direction AR of the head position P2 varies due to, for example, a margin on the downstream side of the print image PI (the +Y side in
In the present embodiment of
Note that owing to the determining of the conveying amount TL of the sheet conveyance T2 to be the corrected conveying amount, as depicted in
In the reference embodiment, the upper limit value NSmax of the nozzle shift amount NS and the lower limit value TLmin of the conveying amount TL are not provided. Due to this, in the reference embodiment, in a case that the excess amount VO is greater than the upper limit value NAmax, the nozzle shift amount NS becomes to be greater than the upper limit value NSmax, as depicted in
Note that in the examples of
As described above, in the reference embodiment, since the length in the conveying direction AR of the end area SA3 cannot be sufficiently secured, it is not possible, for example, to execute the printing of an appropriate end area SA3 as explained in
As appreciated from the foregoing explanation, according to the present embodiment, in a case that the target conveying amount which is the conveying amount for conveying the sheet M from the position at the time of completion of the partial printing executed at the head position P2 to the end-pressing head position is not less than the lower limit value TLmin, the CPU 210 determines the conveying amount TL of the sheet conveyance T2 to the target conveying amount; whereas in a case that the target conveying amount is smaller than the lower limit value TLmin, the CPU 210 determines the conveying amount TL of the sheet conveyance T2 to the corrected conveying amount which is greater than the target conveying amount (in the present embodiment, the lower limit value TLmin) to thereby shift the end-pressing head position. As a result, as described above, since it is possible to suppress the occurrence of such an inconvenience that the length in the conveying direction AR of the end area(s) SA2 and/or SA3 cannot be secured, it is possible to suppress such a situation that the banding becomes conspicuous. As described above, according to the present embodiment, it is possible to improve the image quality of the print image PI.
Further, as appreciated from the above-described relationship of TL=(D−Ha−NS), in a case that the conveying amount TL of the sheet conveyance T2 is smaller than (D−Ha), the nozzle shift amount NS is greater than 0 (zero). Namely, in a case that the conveying amount TL of the sheet conveyance T2 is smaller than (D−Ha), there arises a downstream-side non-used nozzle at the partial printing executed at the head position P3 (
In a case that the number (quantity) of the downstream-side non-used nozzle(s) (nozzle shift amount NS) becomes to be greater than the upper limit value NSmax, the length in the conveying direction AR of the area RA3 printed by the partial printing executed at the head position P3 becomes to be excessively short (
Further, according to the present embodiment, as described above, the corrected conveying amount (the lower limit value TLmin) is the length Ha in the conveying direction AR, of the end area, which is to be secured. By making the corrected conveying amount to be the length Ha, even if the conveying amount TL of the sheet conveyance T2 is minimum, the conveying amount TL becomes to be the length Ha in the conveying direction AR, of the end area, which is to be secured. As a result, it is possible to secure the length in the conveying direction AR of the area RA3 printed by the partial printing executed at the head position P3 by the amount corresponding to (2×Ha), even if the length is minimum. Accordingly, it is possible to secure the lengths in the conveying direction AR of both of the end area SA2 and the end area SA3, for example, to be similar to the length Ha in the conveying direction AR of the end area SAL Accordingly, it is possible to further suppress such a situation that the banding becomes conspicuous. Further, in order to secure the lengths in the conveying direction AR of both of the end area SA2 and the end area SA3, it is sufficient that the corrected conveying amount is a value which is not less than the length Ha in the conveying direction AR of the end area. Thus, the corrected conveying amount may be a value greater than the length Ha in the conveying direction AR of the end area. However, as the corrected conveying amount becomes greater, a shift amount of the head position P3, which is the end-pressing head position, toward the upstream side in the conveying direction AR becomes greater. As the shift amount becomes greater, the width d2 in the conveying direction AR in which each of the pressing members 146 faces the sheet M at the head position P3 (
Further, in the print data outputting processing (
As appreciated from the foregoing explanation, in the present embodiment, the partial printing executed at the head position P1 is an example of a “first partial printing”, the partial printing executed at the head position P2 is an example of a “second partial printing”, the partial printing executed at the head position P3 is an example of a “third partial printing”, and the partial printing executed at the head position P4 is an example of a “fourth partial printing”. The end areas SA1, SA2, SA3 and SA4 are examples, respectively, of a “first end area”, a “second end area”, a “third end area”, and a “fourth end area”. The normal areas NA1, NA2, NA3 and NA4 are examples, respectively, of a “first normal area”, a “second normal area”, a “third normal area”, and a “fourth normal area”. Further, the conveying amount TL of the sheet conveyance T1 is an example of a “first conveying amount”, and the conveying amount TL of the sheet conveyance T2 is an example of a “second conveying amount”. Furthermore, the end-pressing head position is an example of a “specified position”, and the pressing reference position RL is an example of a “reference position”.
In the first embodiment, each of the normal areas (for example, the areas NA0 to NA4 of
In contrast, in a second embodiment, each of the normal areas (for example, the areas NB0 to NB4 of
In the second embodiment, two raster lines which are adjacent each other among the plurality of raster lines arranged side by side in the conveying direction AR within the normal area are printed, respectively, by mutually different (two) partial printings. For example, among the plurality of raster lines arranged side by side in the conveying direction AR within a certain normal area, an odd-numbered raster line is printed by a preceding partial printing constructing a partial printing set printing the certain normal area, and an even-numbered raster line is printed by a succeeding partial printing constructing the partial printing set printing the certain normal area.
Sheet conveyances T1a, T2a, T3a and T4a are each a sheet conveyance which is executed between two partial printings constructing one partial printing set. A conveying amount of each of the sheet conveyances T1a, T2a, T3a and T4a is a minute or fine conveying amount ΔTL, for example, a conveying amount corresponding to a minute odd number (quantity) (in the second embodiment, three pieces) of the raster line. Usable nozzles of the preceding partial printing constructing the partial printing set are nozzles NZ which are included in a plurality of pieces of the nozzle NZ corresponding to the nozzle length D and of which number (quantity) is obtained by deducting, from the plurality of nozzles NZ corresponding to the nozzle length D, a certain number (quantity) of (in the second embodiment, one piece) the nozzle NZ on the downstream side (+Y side) in accordance with the minute conveying amount ΔTL. Usable nozzles of the succeeding partial printing constructing the partial printing set are nozzles NZ which are included in the plurality of pieces of the nozzle NZ corresponding to the nozzle length D and of which number (quantity) is obtained by deducting, from the plurality of nozzles NZ corresponding to the nozzle length D, a certain number (quantity) of (in the second embodiment, one piece) the nozzle NZ on the upstream side (−Y side) in accordance with the minute conveying amount ΔTL.
The sheet conveyance T0b is a sheet conveyance performed after the partial printing set executed at the head positions P0a and P0b. The sheet conveyances T1b, T2b and T3b are, respectively, a sheet conveyance performed after the partial printing set executed at the head positions P1a and P1b, a sheet conveyance performed after the partial printing set executed at the head positions P2a and P2b, and a sheet conveyance performed after the partial printing set executed at the head positions P3a and P3b.
The area RB0 printed by the partial printing set executed at the head positions P0a and P0b includes a normal area NB0 and an end area SB0 which is on the upstream side (−Y side) with respect to the normal area NB0. The area RB1 printed by the partial printing set executed at the head positions P1a and P1b includes a normal area NB1, the end area SB0 which is on the downstream side (+Y side) with respect to the normal area NB1, and an end area SB1 which is on the upstream side (−Y side) with respect to the normal area NB1. The area RB2 printed by the partial printing set executed at the head positions P2a and P2b includes a normal area NB2, the end area SB1 which is on the downstream side (+Y side) with respect to the normal area NB2, and an end area SB2 which is on the upstream side (−Y side) with respect to the normal area NB2. The area RB3 printed by the partial printing set executed at the head positions P3a and P3b includes a normal area NB3, the end area SB2 which is on the downstream side (+Y side) with respect to the normal area NB3, and an end area SB3 which is on the upstream side (−Y side) with respect to the normal area NB3. The area RB4 printed by the partial printing set executed at the head positions P4a and P4b includes a normal area NB4, and the end area SB3 which is on the downstream side (+Y side) with respect to the normal area NB4.
Each of the raster lines in the end area is printed by two partial printing sets. For example, in each of the raster lines of the end area SB1 of
In the second embodiment, a partial printing set which is included in the plurality of partial printing sets and which is different from the last partial printing set is performed in a state that the sheet M is pressed by the pressing members 146. The last partial printing set is performed in a state that the sheet M is not pressed by the pressing members 146. A succeeding partial printing constructing the penultimate partial printing set immediately before the last partial printing set is performed at the end-pressing head position. In the example of
In the second embodiment, in a case that a foremost partial printing set, which is the partial printing set performed first or foremost among the plurality of partial printing sets and which is a first partial printing set of printing a plurality of raster lines including a raster line positioned at the upstream side with respect to a pressing reference position RLb (
In the example of
In the example of
In the example of
Here, similarly to the first embodiment, since the position in the conveying direction AR of the head position P2b varies due to, for example, a margin on the downstream side of the print image PIb (the +Y side in
In the present embodiment of
Accordingly, in
In the reference embodiment of
Therefore, in
As appreciated from the foregoing explanation, in the reference embodiment, since the length in the conveying direction AR of the end area SB3 cannot be sufficiently secured, it is not possible to appropriately execute the printing of the end area SB3. Accordingly, in the reference embodiment, there is such a possibility that a banding might become conspicuous in the end area SB3 of the print image PIb. In contrast, in the present embodiment, it is possible to sufficiently secure the length in the conveying direction AR of the end area SB3, it is possible to appropriately execute the printing of the end area SB3, and thus to prevent such a situation that the banding becomes conspicuous in the print image PIb.
As appreciated from the foregoing explanation, the two partial printings executed at the head position P1a, P1b in the present embodiment are an example of the “first partial printing”, the two partial printings executed at the head positions P2a, P2b are an example of the “second partial printing”, the two partial printings executed at the head position P3a, P3b are an example of the “third partial printing”, and the two partial printings executed at the head positions P4a, P4b are an example of the “fourth partial printing”. Further, the end areas SB1, SB2, SB3 and SB4 are examples, respectively, of the “first end area”, the “second end area”, the “third end area” and the “fourth end area”. The normal areas NB1, NB2, NB3 and NB4 are examples, respectively, of the “first normal area”, the “second normal area”, the “third normal area”, and the “fourth normal area”. Furthermore, the conveying amount TLb of the sheet conveyance Tlb is an example of the “first conveying amount”, and the conveying amount TLb of the sheet conveyance T2b is an example of the “second conveying amount”.
In the above-described second embodiment, one partial printing set is constructed of two partial printings. Instead of this, it is allowable that one partial printing set is constructed of not less than two partial printings, for example, three or four partial printings. Generally, one partial printing set may be constructed of N times (N is an integer not less than 2). In such a case, N pieces of raster line which are included in the plurality of raster lines arranged side by side in the conveying direction within each of the normal areas and which are adjacent to each other are printed, respectively, by mutually different (N times of) partial printings which are included in one partial printing set.
In the first embodiment, each of the corrected conveying amount and the lower limit value TLmin is the length Ha in the conveying direction AR of the end area SA1. Instead of this, it is allowable that each of the corrected conveying amount and the lower limit value TLmin is a value which is greater, by a small extent, than the length Ha in the conveying direction AR of the end area SA1, for example, a value greater than the length Ha in the conveying direction AR of the end area SA1 by a value corresponding to a several pieces of the raster line.
The printing processing in
As the medium, another medium different from the sheet M, such as, for example, a film for OHP, a CD-ROM, a DVD-ROM, etc., may be adopted, instead of the sheet M.
In each of the above-described embodiments, the controller configured to execute the printing process in
The controller configured to execute the printing process in
In each of the above-described embodiments, a part of the configuration realized by a hardware may be replaced by a software; on the contrary to this, a part or the entirety of the configuration realized by a software may be replaced with a hardware. For example, a processing or processings as a part of the print processing of
In the foregoing, although the present disclosure has been explained based on the embodiments and the modifications, the embodiments of the present disclosure are provided for the purpose that the present disclosure can be easily understood, and is not intended to limit or restrict the present disclosure in any way. The present disclosure may be changed and/or improved without deviating from the gist and spirit of the present disclosure and the scope of the claims, and may encompasses any equivalent thereof
| Number | Date | Country | Kind |
|---|---|---|---|
| 2021-077411 | Apr 2021 | JP | national |
| Number | Name | Date | Kind |
|---|---|---|---|
| 5949452 | Jones | Sep 1999 | A |
| 20130208065 | Yamamoto | Aug 2013 | A1 |
| 20160243862 | Yoshida | Aug 2016 | A1 |
| 20160271935 | Miyamoto | Sep 2016 | A1 |
| 20190232679 | Arakane | Aug 2019 | A1 |
| 20220126608 | Yamaguchi | Apr 2022 | A1 |
| Number | Date | Country |
|---|---|---|
| H10157096 | Jun 1998 | JP |
| 2006027131 | Feb 2006 | JP |
| 2009143135 | Jul 2009 | JP |
| 2016153182 | Aug 2016 | JP |
| 2016175373 | Oct 2016 | JP |
| 2019130752 | Aug 2019 | JP |
| Number | Date | Country | |
|---|---|---|---|
| 20220348027 A1 | Nov 2022 | US |
