Patent Application
20200086654
This application is based upon and claims the benefit of priority from prior Japanese patent application No. 2018-173136, filed on Sep. 15, 2018, the entire contents of which are incorporated herein by reference.
The present disclosure relates to image processing for a printing execution unit capable of forming a plurality of types of dots on a printing medium.
A printer configured to print an image by discharging ink from nozzles of a printing head has been known. In the printer, for example, when a temperature of the ink is relatively low, a viscosity of the ink is increased, so that delay in ink supply from an accommodation part of the ink to the printing head is likely to occur. When the delay in ink supply occurs, an image quality is deteriorated due to thinning of a print image, for example.
Related art discloses a technology of, when the number of continuous discharging of dots counted in a band is larger than a threshold value corresponding to a temperature of the printing head, increasing the number of passes to print the band.
However, according to the technology, when the number of passes to print the band is increased, an image quality of an image to be printed may be deteriorated.
Aspects of the present disclosure discloses a technology capable of reducing delay in ink supply and also reducing deterioration in an image quality resulting from reducing the delay in the ink supply.
According to an aspect of the disclosure, there is provided an image processing device for a printing execution unit including: a printing head having a plurality of nozzles configured to discharge ink; an ink supply unit configured to supply the ink to the printing head; a main scanning unit configured to execute a main scanning in which the printing head is moved relative to a printing medium in a main scanning direction; and a sub-scanning unit configured to execute a sub-scanning in which the printing medium is moved relative to the printing head in a sub-scanning direction intersecting with the main scanning direction, the image processing device including: a controller configured to perform: acquiring image data; and causing the printing execution unit to perform printing by using the acquired image data, the printing being performed by executing, for a plurality of times, (i) partial printing in which the printing head is caused to discharge the ink while causing the main scanning unit to execute the main scanning and (ii) sub-scanning in which the sub-scanning unit is caused to execute the sub-scanning, wherein the printing execution unit is caused to perform the printing by: in a first case where a specific condition is not satisfied, printing a partial image by single partial printing, the partial image being a part of an image to be printed and corresponding to the partial printing, the specific condition being determined for each partial image, and the specific condition indicating that ink supply from the ink supply unit to the printing head may be delayed in the partial printing; in a second case where the specific condition is satisfied, printing the partial image by a plurality of partial printings including a first partial printing and a second partial printing; in the first case, forming a dot having a specific size by the single partial printing, as a dot corresponding to a specific pixel in the partial image; and in the second case, forming a dot having a size smaller than the specific size by the first partial printing and forming a dot having a size smaller than the specific size by the second partial printing, as the dot corresponding to the specific pixel.
According to the above configuration, in the second case where the specific condition is satisfied, the partial image is printed by the plurality of partial printings including the first partial printing and the second partial printing. Therefore, it is possible to reduce the delay in ink supply, as compared to a case where the partial image is printed by the single partial printing. Also, in the second case where the specific condition is satisfied, the dot corresponding to the specific pixel in the partial image is formed by both the first partial printing and the second partial printing. Therefore, a part in which dots are formed only by the first partial printing and a part in which dots are formed only by the second partial printing are reduced in an image to be printed. As a result, it is possible to reduce occurring of a failure that a boundary between the part in which the dots are formed only by the first partial printing and the part in which the dots are formed only by the second partial printing is noticeable. Therefore, while reducing the delay in ink supply, it is possible to reduce deterioration in an image quality resulting from reducing the delay in ink supply.
In the meantime, the technology of the present disclosure can be implemented in a variety of forms, such as a printing apparatus, a control method of the printing execution unit, a printing method, a storage medium having a computer program stored therein, and the like.
A-1: Configuration of Printer 200
Hereinafter, an exemplary embodiment is described.
The printer 200 includes, for example, a printing mechanism 100, a CPU 210 as a controller of the printer 200, a non-volatile storage device 220 such as a hard disk drive, a volatile storage device 230 such as a RAM, an operation unit 260 such as a button and a touch panel for acquiring a user's operation, a display unit 270 such as a liquid crystal monitor, and a communication unit 280. The communication unit 280 includes a wired or wireless interface for connecting to a network NW. The printer 200 is communicatively connected to an external apparatus, for example, a terminal apparatus 300 via the communication unit 280.
The volatile storage device 230 provides a buffer area 231 for temporarily storing therein a variety of intermediate data that are generated when the CPU 210 performs processing. In the non-volatile storage device 220, a computer program PG and a control table group TG are stored. In the first exemplary embodiment, the computer program PG is a control program for controlling the printer 200. The computer program PG and the control table group TG may be provided while being stored in the non-volatile storage device 220 upon shipment of the printer 200. Instead of this configuration, the computer program PG and the control table group TG may be downloaded from a server or may be provided in a state of being stored in a DVD-ROM and the like. The CPU 210 is configured to execute the computer program PG, thereby executing image processing to be described later, for example. Thereby, the CPU 210 controls the printing mechanism 100 to print an image on a printing medium (for example, sheet). The control table group TG is a table for determining a parameter to be used in the image processing. The control table group TG will be described later.
The printing mechanism 100 can form dots on a sheet M by using inks (ink droplets) of cyan (C), magenta (M), yellow (Y) and black (K), thereby performing color printing. The printing mechanism 100 includes a printing head 110, a head drive unit 120, a main scanning unit 130, a conveyor unit 140, an ink supply unit 150 and a temperature sensor 170.
The conveyor unit 140 is configured to convey the sheet M in a conveying direction (+Y direction, in
The ink supply unit 150 is configured to supply ink to the printing head 110. The ink supply unit 150 includes a cartridge mounting unit 151, tubes 152, and a buffer tank 153. A plurality of ink cartridges KC, CC, MC, YC in which inks are accommodated is detachably mounted to the cartridge mounting unit 151, and the inks are supplied from the ink cartridges. The buffer tank 153 is arranged above the printing head 110 mounted to the carriage 133, and is configured to temporarily accommodate therein each ink of CMYK to be supplied to the printing head 110. The tube 152 is a flexible tube configured to interconnect the cartridge mounting unit 151 and the buffer tank 153 and becoming a flow path of the ink. The ink in each ink cartridge is supplied to the printing head 110 through the cartridge mounting unit 151, the tube 152 and the buffer tank 153. The buffer tank 153 is provided with a filter (not shown) for removing foreign matters mixed in the ink.
Positions of the nozzle rows NC, NM, NY, NK in the main scanning direction are different, and positions thereof in a sub-scanning direction overlap each other. For example, in the example of
Each nozzle NZ is connected to the buffer tank 153 through an ink flow path (not shown) formed in the printing head 110. Actuators (not shown, piezoelectric elements, in the first exemplary embodiment) for discharging the inks along the respective ink flow paths in the printing head 110 are provided.
The head drive unit 120 (
The temperature sensor 170 is a well-known temperature sensor including a temperature measurement resistance member and the like, and is provided in the vicinity of the printing head 110 of the printer 200. The temperature sensor 170 is configured to output a signal indicative of a temperature of the printing head 110 of the printer 200.
A-2. Outline of Printing
The CPU 210 is configured to print a print image on the sheet M by alternately executing, for a plurality of times, partial printing of causing the printing head 110 to discharge the inks to form dots on the sheet M while causing the main scanning unit 130 to execute the main scanning, and a sub-scanning (conveyance of the sheet M) by the conveyor unit 140.
In the partial image of
As shown in
In
Here, when the ink is discharged from the nozzles NZ during the printing, the ink is reduced in the buffer tank 153 (
The delay in ink supply is likely to occur when flowability of the ink is lowered. For example, the lower a temperature (hereinafter, also referred to as ‘head temperature Th’) of the printing head 110 of the printer 200 (the printing mechanism 100) is, the more the delay in ink supply is likely to occur. The reason is that as the head temperature Th is lowered, a viscosity of the ink is increased, resulting in a decrease in flowability of the ink. Here, a cumulative-use amount TA of ink is an index value indicative of a cumulative-use amount of a specific ink (any one of C, M, Y and K) up to now since the manufacturing of the printer 200. The larger the cumulative-use amount TA of ink is, the more the delay of specific ink supply is likely to occur. The reason is that as the cumulative-use amount TA of ink increases, an accumulation amount of foreign matters in a filter for removing the foreign matters in the ink increases, resulting in an increase in flow path resistance of the ink and a decrease in flowability of the ink. Also, a pass-use amount PA of ink is an index value indicative of a use amount of the specific ink to be used for partial image printing in the single partial printing. The larger the pass-use amount PA of ink is, the more the delay of specific ink supply is likely to occur. The reason is that since the specific ink is used in a short time, the specific ink supply cannot keep up with the use amount.
In image processing to be described below, a scheme for reducing the delay in ink supply is made. Specifically, when printing a specific partial image (the partial image PI3, in the example of
A-3. Image Processing
In S105, the CPU 210 controls the conveyor unit 140 to convey (feed) one sheet M from a print tray (not shown) to a predetermined initial position.
In S110, the CPU 210 acquires partial dot data, which corresponds to a partial image to be printed by the single partial printing, as notice partial dot data, and stores the same in the buffer area 331. For example, the CPU 210 acquires the notice partial dot data by receiving the notice partial dot data from the terminal apparatus 300. In the first exemplary embodiment, the notice partial dot data is data (dot data) indicative of a formation state of dot for each color component and for each pixel. In the first exemplary embodiment, the formation state of dot is any one of “extra-large dot”, “large dot”, “medium dot”, “small dot” and “no dot”. Meanwhile, in a modified embodiment, the CPU 210 may generate the notice partial dot data by using the image data stored in the volatile storage device 230, thereby acquiring the notice partial dot data. In this case, for example, generation processing including color conversion processing and halftone processing is executed for partial image data, which corresponds to the partial image, of the image data, so that the notice partial dot data is generated.
Here, the partial image corresponding to the notice partial dot data is also referred to as ‘notice partial image’. Also, the partial printing for printing the notice partial image is also referred to as ‘notice partial printing’.
In S115, the CPU 210 controls the conveyor unit 140 to convey the sheet M so that a position of the printing head 110 relative to the sheet M in the conveying direction is to be a position in which the notice partial image is to be printed. For example, when the second partial printing and thereafter is the notice partial printing, the sheet M is conveyed by the nozzle length D, as can be seen from
In S120, the CPU 210 executes condition determination processing. The condition determination processing is processing of determining whether a specific condition, which indicates that the ink supply from the ink supply unit 150 to the printing head 110 in the notice partial printing may be delayed, is satisfied.
In S220, the CPU 210 acquires the cumulative-use amount TA of each ink to be used for printing from the non-volatile storage device 220. The cumulative-use amount TA of ink is recorded for each ink of CMYK in a predetermined area of the non-volatile storage device 220. The CPU 210 calculates a use amount of ink of each color based on the number of dots formed by the printing and updates the cumulative-use amount TA of ink whenever executing the printing, for example. In S220, for example, in the case of monochrome printing, the cumulative-use amount TA of black (K) ink is acquired, and in the case of color printing, the cumulative-use amount TA of each ink of CMYK is acquired.
In S230, the CPU 210 acquires, based on the head temperature Th and the cumulative-use amount TA of ink, a determination threshold value JT corresponding to each ink to be used for printing, from a threshold value table TT.
As shown in
In S240, the CPU 210 calculates a dot formation ratio DR of each ink to be used for printing by using the notice partial image data. The dot formation ratio DR is calculated as follows. For example, a use amount of ink per one dot of “extra-large dot”, “large dot”, “medium dot” and “small dot” is set to 30 pl (picoliter), 20 pl, 10 pl and 5 pl, respectively. The CPU 210 calculates the numbers Nbb, Nb, Nm, Ns of respective formed dots of “extra-large dot”, “large dot”, “medium dot” and “small dot”. The CPU 210 calculates, as a use amount IV of ink of the notice partial image, a sum of values obtained by multiplying the use amount of ink per one dot by each of the numbers Nbb, Nb, Nm, Ns of dots having respective sizes (IV=(30×Nbb)+(20×Nb)+(10×Nm)+(5×Ns)). The CPU 210 calculates the dot formation ratio DR by dividing the use amount IV of ink by a maximum value IVmax of the use amount IV of ink and multiplying a resultant value by 100 (DR=(IV/IVmax)×100). The maximum value IVmax is a value obtained by multiplying the use amount (30 pl) of ink per one extra-large dot by a total number TN of pixels of the notice partial image (IVmax=30×TN). The dot formation ratio DR can be said as an index value indicating a dot formation degree when a state in which the extra-large dots are formed in all pixels in the notice partial image is set to 100% and a state in which no dot is formed in all pixels in the notice partial image is set to 0%. The greater the dot formation ratio DR of the specific ink is, the pass-use amount PA of the specific ink increases. Therefore, it can be said that the dot formation ratio DR is an index value indicative of the pass-use amount PA of ink. In the case of the monochrome printing, the dot formation ratio DR corresponding to the black (K) ink is calculated, and in the case of the color printing, the dot formation ratio DR corresponding to each ink of CMYK is calculated.
In S250, the CPU 210 determines whether the dot formation ratio DR is greater than the determination threshold value JT, for at least one ink to be used for printing. When it is determined that the dot formation ratio DR is greater than the determination threshold value JT, a large amount of ink is discharged in a short time, so that the delay in ink supply may occur. For this reason, when it is determined for at least one ink to be used for printing that the dot formation ratio DR is greater than the determination threshold value JT (S250: YES), the CPU 210 determines in S270 that the specific condition is satisfied. When it is determined for all inks to be used for printing that the dot formation ratio DR is equal to or smaller than the determination threshold value JT (S250: NO), the CPU 210 determines in S260 that the specific condition is not satisfied. When the determination as to whether the specific condition is satisfied is made, the condition determination processing is over.
When the condition determination processing is over, it is determined in S125 of
When it is determined that the specific condition is satisfied (S125: YES), the CPU 210 executes special partial printing in S135 to S150. In the special partial printing, the notice partial image is printed on the sheet by two partial printings.
In S135, the CPU 210 generates first dot data by using the notice partial dot data, with reference to a replacement table RT.
In S140, the CPU 210 controls the main scanning unit 130 and the printing head 110 of the printing mechanism 100 by using the first dot data, thereby executing first partial printing. When the previous partial printing is the forward printing, the backward printing is executed as the first partial printing, and when the previous partial printing is the backward printing, the forward printing is executed as the first partial printing. Thereby, the first dot image DI1 (
In S145, the CPU 210 generates second dot data by using the notice partial dot data, with reference to the replacement table RT.
In S150, the CPU 210 controls the main scanning unit 130 and the printing head 110 of the printing mechanism 100 by using the second dot data, thereby executing second partial printing. When the first partial printing is the forward printing, the backward printing is executed as the second partial printing, and when the first partial printing is the backward printing, the forward printing is executed as the second partial printing. Thereby, the second dot image DI2 (
Here, the sheet M is not conveyed between the first partial printing in S140 and the second partial printing in S150. As a result, the dot image DI1 and the dot image DI2 are printed with being superimposed in the same area on the sheet M. An image in which the dot image DI1 and the dot image DI2 are superimposed is printed on the sheet M, as the notice partial image.
As can be seen from the above descriptions, in the special partial printing of the first exemplary embodiment, the medium dot is formed by the first partial printing and the large dot is formed by the second partial printing at the position on the sheet M at which the extra-large dot is to be formed in a case where the notice partial printing is performed by the usual partial printing. Likewise, in the special partial printing, the medium dot is formed by the first partial printing and the medium dot is formed by the second partial printing at the position on the sheet M at which the large dot is to be formed in a case where the notice partial printing is performed by the usual partial printing. In the special partial printing of the first exemplary embodiment, no dot is formed by the first partial printing and the small dot or the medium dot is formed by the second partial printing at the position on the sheet M at which the small dot or the medium dot is to be formed in a case where the notice partial printing is performed by the usual partial printing.
In S155, the CPU 210 determines whether all partial images of an image to be printed have been printed. When it is determined that all the partial images have been printed (S155: YES), the CPU 210 ends the image processing. When it is determined that there is a partial image not printed yet (S155: NO), the CPU 210 returns to S110.
According to the first exemplary embodiment, it is determined for each partial image of an image to be printed whether the specific condition, which indicates that the ink supply may be delayed, is satisfied (S120 in
In this way, when the specific condition, which indicates that the ink supply may be delayed, is satisfied, the partial image is printed by the first partial printing and the second partial printing, so that it is possible to reduce the delay in ink supply as compared to a case where the partial image is printed by the single partial printing. The reason is that the amount of ink to be used in a short time is reduced. Also, when the specific condition is satisfied, the dots corresponding to the specific pixels (for example, the pixels PX1 and PX2) in the partial image are printed by both the first partial printing and the second partial printing. Therefore, for example, as compared to a case where the notice partial image is printed by simple two-pass printing, a part in which the dots are to be formed only by the first partial printing and a part in which the dots are to be formed only by the second partial printing are reduced in the print image OI. As a result, it is possible to reduce a failure that a boundary between the part in which the dots are to be formed only by the first partial printing and the part in which the dots are to be formed only by the second partial printing is noticeable. Therefore, while reducing the delay in ink supply, it is possible to reduce deterioration in an image quality resulting from reducing the delay in ink supply.
For example, in the simple two-pass printing, dots are formed in some of pixels, in which dots are to be formed, by the first partial printing, and dots are formed in the other pixels of the pixels, in which dots are to be formed, by the second partial printing. In this case, it is assumed that positions of the dots formed by the second partial printing deviate from positions of the dots formed by the first partial printing due to a conveyance error, an error of the main scanning, and the like. In this case, since the part in which the dots are to be formed only by the second partial printing deviates from the part in which the dots are to be formed only by the first partial printing, the boundary therebetween may be noticeable. However, according to the first exemplary embodiment, it is possible to reduce such failure.
In the first exemplary embodiment, in the pixels, which correspond to the pixels of the original dot image DI0 in which the extra-large dot and the large dot are arranged, of the plurality of pixels of the two dot images DI1, DI2 printed by the special partial printing, the dots are arranged in both the dot images DI1, DI2 (
Here, in the first exemplary embodiment, when two medium dots are formed at the specific position on the sheet M, the two medium dots superimposed on each other become a dot having an area equivalent to one large dot. Also, when one large dot and one medium dot are formed at the specific position on the sheet M, the dots superimposed on each other become a dot having an area equivalent to one extra-large dot. For this reason, the partial image, which is printed by using the specific partial dot data by the usual partial printing, and the partial image, which is printed by using the specific partial dot data by the special partial printing, can express images having substantially the same densities. As a result, it is possible to reduce a situation in which a density of an image to be printed is changed to deteriorate an image quality as a result of reducing the delay in ink supply, for example.
Also, according to the first exemplary embodiment, in the usual partial printing, the extra-large dot is formed by the single partial printing, as the dot corresponding to the pixel for which the formation of extra-large dot by the notice partial dot data is defined. In contrast, in the special partial printing, the medium dot smaller than the extra-large dot is formed by the first partial printing and the large dot smaller than the extra-large dot is formed by the second partial printing, as the dot corresponding to the pixel for which the formation of extra-large dot by the notice partial dot data is defined. As a result, it is possible to appropriately execute the two partial printings, based on the notice partial dot data.
More specifically, in the usual partial printing, the single partial printing is executed using the partial dot data (S130 in
Also, according to the first exemplary embodiment, in the special partial printing, as the dot corresponding to the specific pixel PX1 for which the formation of the extra-large dot is defined in the partial dot data, the medium dot is formed by the first partial printing to be executed first, and the large dot is formed by the second partial printing to be executed later. Also, as the dot corresponding to the specific pixel PX2 for which the formation of the large dot is defined in the partial dot data, the medium dot is formed by both the first partial printing and the second partial printing. In this way, in the special partial printing, the dot having a first size smaller than a specific size defined in the partial dot data is formed by the first partial printing, and the dot having a second size smaller than the specific size and equal to or larger than the first size is formed by the second partial printing. When printing the same area by the two partial printings, the ink attached by the first partial printing of first time permeates into the sheet M, so that the sheet M may be partially extended and deformed. For example, the sheet M may be deformed to approach the printing head 110. In this state, when the second partial printing of second time is executed, the sheet M may contact the nozzle formation surface 111 of the printing head 110. In this case, the sheet M may be smudged or the nozzles NZ on the nozzle formation surface 111 may be damaged. Also, a distance between the nozzle formation surface 111 and the sheet M becomes shorter than expected, so that a spotting position of ink discharged in the second partial printing becomes different from an expected position. As a result, an image quality of an image to be printed may be deteriorated. For this reason, it is preferable to reduce the deformation of the sheet M after the first partial printing by reducing the amount of ink discharged in the first partial printing as much as possible. If the large dot is formed by the first partial printing and the medium dot is formed by the second partial printing, as the dot corresponding to the pixel PX1, an amount of ink discharged in the first partial printing becomes larger than an amount of ink discharged in the second partial printing, so that it may not be possible to reduce the deformation of the sheet M after the first partial printing. However, according to the first exemplary embodiment, since the amount of ink discharged in the first partial printing is equal to or smaller than the amount of ink discharged in the second partial printing, it is possible to reduce the above failures.
According to the above configuration, the amount of ink to be discharged in correspondence to the specific pixel in the first partial printing to be executed first can be set equal to or smaller than the amount of ink to be discharged in correspondence to the specific pixel in the second partial printing to be executed later. As a result, it is possible to reduce the deformation of the printing medium due to the ink discharged in the first partial printing. Therefore, it is possible to reduce the failure, which is caused due to the deformation of the printing medium during the second partial printing.
Also, according to the first exemplary embodiment, in the special partial printing, a total amount of ink to be discharged in the first partial printing to be executed first is set equal to or smaller than a total amount of ink to be discharged in the second partial printing to be executed later. As a result, it is possible to reduce the deformation of the sheet M, which is caused due to the ink discharged in the first partial printing. As a result, it is possible to reduce the failure due to the deformation of the sheet M during the second partial printing.
Also, according to the first exemplary embodiment, in the special partial printing, as the dot corresponding to the specific pixel (for example, the pixel PX3) for which the formation of the medium dot is defined in the partial dot data, no dot is formed by the first partial printing and the medium dot is formed by the second partial printing. Likewise, in the special partial printing, as the dot corresponding to the specific pixel (for example, the pixel PX4) for which the formation of the small dot is defined in the partial dot data, no dot is formed by the first partial printing and the small dot is formed by the second partial printing. As a result, as described above, it is possible to reduce the total amount of ink to be discharged in the first partial printing and to increase the total amount of ink to be discharged in the second partial printing. Therefore, it is possible to further reduce the deformation of the sheet M due to the ink discharged in the first partial printing.
Also, according to the first exemplary embodiment, as the index value that is used so as to determine the specific condition indicating that the delay in ink supply may occur, the dot formation ratio DR, which is a value relating to the pass-use amount PA of ink, and the cumulative-use amount TA of ink are used. As a result, it is possible to appropriately determine whether the ink supply may be delayed.
Specifically, as described above, the larger the cumulative-use amount TA of ink is, the more the delay in ink supply is likely to occur. Also, the larger the pass-use amount PA of ink is, the more the specific delay in ink supply is likely to occur. Considering the situations, it is set in the threshold value table TT that the larger the cumulative-use amount TA of ink is, the smaller the determination threshold value JT, which is set for the dot formation ratio DR, is (
Also, the lower the head temperature Th is, the more the delay in ink supply is likely to occur. In the first exemplary embodiment, as the index value that is used so as to determine the specific condition, the head temperature Th is further used (
In the second exemplary embodiment, a dot size, which is actually formed in correspondence to a pixel value indicating the formation of the extra-large dot of the dot data (the partial dot data, the first dot data, the second dot data), is different between the usual partial printing and the special partial printing. Also, a dot size, which is actually formed in correspondence to a pixel value indicating the formation of the large dot of the dot data, is different between the usual partial printing and the special partial printing. Such change in dot size is implemented by changing a waveform (hereinafter, referred to as ‘drive waveform’) of a drive signal, which is supplied from the head drive unit 120 to the actuator of the printing head 110, between the usual partial printing and the special partial printing, in correspondence to the pixel value of the dot data.
Specifically, in S128B of
In the second exemplary embodiment, five types of waveforms 1 to 5 different from each other are used. The drive waveform is a waveform corresponding to one dot. The more pluses included in one waveform are, the larger the amount of ink to be discharged is, so that a larger dot is formed. Also, the higher a maximum voltage of each pulse included in one waveform is, the larger the amount of ink to be discharged is, so that a larger dot is formed. The waveforms 1 to 5 are set so that as the waveform number increases, a larger dot is formed. The five types of dots corresponding to the waveforms 1 to 5 are Dots 1 to 5. As the dot number increases, a dot size increases. That is, the dot size is Dot 5>Dot 4>Dot 3>Dot 2>Dot 1. As shown in the drive waveform table WT, in the usual partial printing, the waveform 5, the waveform 4, the waveform 2 and the waveform 1 are respectively associated with the respective pixel values indicative of the formations of the extra-large dot, the large dot, the medium dot and the small dot, as the drive waveform. That is, in the usual partial printing, Dot 5, Dot 4, Dot 2 and Dot 1 are formed in correspondence to the respective pixel values indicative of the formations of the extra-large dot, the large dot, the medium dot and the small dot.
In S133B of
As can be seen from the above descriptions, in the usual partial printing and in the special partial printing, the dot to be formed in correspondence to the pixel value indicative of the formation of the small dot is the dot (Dot 1) of the same size. In the usual partial printing and in the special partial printing, the dot to be formed in correspondence to the pixel value indicative of the formation of the medium dot is the dot (Dot 2) of the same size.
In contrast, the dot to be formed in correspondence to the pixel value indicative of the formation of the large dot is Dot 4 in the usual partial printing and is Dot 3 smaller than Dot 4 in the special partial printing. Also, the dot to be formed in correspondence to the pixel value indicative of the formation of the extra-large dot is Dot 5 in the usual partial printing and is Dot 4 smaller than Dot 5 in the special partial printing.
Here, in the second exemplary embodiment, the replacement table RT2 (
Here, in the second exemplary embodiment, as described above, the drive waveform is changed between the usual partial printing and the special partial printing. For this reason, even in the case that the partial dot data to be used in the usual partial printing and the second dot data to be used in the second partial printing of the special partial printing are the same, a dot image (also referred to as ‘actual dot image’) to be actually printed on the sheet M is different between the usual partial printing and the second partial printing.
As shown in
According to the second exemplary embodiment, in the usual partial printing, Dot 5 is formed as the dot corresponding to the specific pixel PX1 in the notice partial image (
Meanwhile, in the second exemplary embodiment, when two Dots 3 are formed at the specific position on the sheet M, the two superimposed Dots 3 become a dot having an area equivalent to one Dot 4. Also, when one Dot 3 and one Dot 4 are formed at the specific position on the sheet M, the two superimposed dots become a dot having an area equivalent to one Dot 5.
Also, according to the second exemplary embodiment, in the usual partial printing, the dot size, which is formed based on the pixel value indicative of the formation of the extra-large dot, is set to a predetermined size (a size of Dot 5) (S123B in
(1) In the first exemplary embodiment, the four types of dots “small”, “medium”, “large” and “extra-large” are used for printing. However, the present disclosure is not limited thereto. For example, the three types of dots “small”, “medium” and “large” may be used. In this case, for example, when the large dot is formed in the usual partial printing, as the dot corresponding to the specific pixel in the partial image, the medium dot is formed by the first partial printing and the medium dot is formed by the second partial printing in the special partial printing, as the dot corresponding to the specific pixel. Also, the two types of dots “small” and “large” may be used. In this case, for example, when the large dot is formed in the usual partial printing, as the dot corresponding to the specific pixel in the partial image, the small dot is formed by the first partial printing and the small dot is formed by the second partial printing in the special partial printing, as the dot corresponding to the specific pixel.
(2) In the above exemplary embodiments, in the special partial printing, the first dot data and the second dot data are generated using the partial dot data (for example, S135 and S145 in
(3) In the first exemplary embodiment, in the special partial printing, as the dot corresponding to the pixel for which the formation of the extra-large dot by the partial dot data is defined, the medium dot is formed by the first partial printing, and the large dot is formed by the second partial printing. Instead of this configuration, as the dot corresponding to the pixel for which the formation of the extra-large dot by the partial dot data is defined, the large dot may be formed by the first partial printing, and the medium dot may be formed by the second partial printing.
(4) In the first exemplary embodiment, in the special partial printing, as the dot corresponding to the pixel for which the formation of the medium dot and the small dot by the partial dot data is defined, no dot is formed by the first partial printing and the medium dot and the small dot are formed by the second partial printing (
(5) In the respective exemplary embodiments, it is determined whether the specific condition, which indicates that the ink supply may be delayed, is satisfied in each partial printing (S125 in
(6) In the respective exemplary embodiments, the condition indicating whether the delay in ink supply may occur is determined using the head temperature Th, the cumulative-use amount TA of ink and the dot formation ratio DR. However, the present disclosure is not limited thereto. For example, only the head temperature Th and the dot formation ratio DR may be used. In this case, for example, in the threshold value table TT of
(7) Instead of the dot formation ratio DR, a separate index value relating to the pass-use amount PA of ink may be adopted. For example, the separate index value may be a total number of dots of each ink to be formed when printing the notice partial image. Also, for example, the separate index value may be a cumulative value of the component value of each ink of the CMYK image data corresponding to the notice partial image. Also, instead of the cumulative-use amount TA of ink, a separate index value relating to the cumulative-use amount of ink may be adopted. For example, the separate index value may be a cumulative number of printed sheets or may be a cumulative number of replacement times of the ink cartridge. It can be said that the greater the cumulative number of printed sheets or the cumulative number of replacement times is, the larger the cumulative-use amount TA of ink is. Therefore, it can be said that the cumulative number of printed sheets is an index value relating to the cumulative-use amount TA of ink.
(8) In the printing mechanism 100 of the respective exemplary embodiments, the sub-scanning in which the conveyor unit 140 conveys the sheet M to move the sheet M relative to the printing head 110 in the conveying direction is performed. Instead of this configuration, the sub-scanning may be performed by moving the printing head 110 relative to the fixed sheet M in an opposite direction to the conveying direction.
(9) In the special partial printing of the respective exemplary embodiments, the notice partial image is printed by the two partial printings that are executed without conveying the sheet M. Instead of this configuration, in the special partial printing, the notice partial image may be printed by three or more partial printings that are executed without conveying the sheet M. For example, when the notice partial image is printed by the three partial printings, the small dot is respectively formed by the three partial printings, at a position corresponding to the pixel value, which indicates the formation of the extra-large dot in the notice partial dot data. At a position corresponding to the pixel value indicative of the formation of the large dot, the small dot is respectively formed by the last two partial printings of the three partial printings. At positions corresponding to the pixel values indicative of the formation of the medium dot and the small dot, the medium dot and the small dot are formed by the last partial printing of the three partial printings.
(10) As the printing medium, instead of the sheet M, other media such as an OHP film, a CD-ROM, and a DVD-ROM may be adopted.
(11) In the respective exemplary embodiments, the device configured to execute the image processing of
As can be seen from the above descriptions, in the respective exemplary embodiments, the printing mechanism 100 is an example of the printing execution unit. Meanwhile, like this modified embodiment, in a case where the terminal apparatus 300 executes the image processing, the entire printer 200 configured to execute the printing is an example of the printing execution unit.
(12) The device configured to execute the image processing of
(13) In the respective exemplary embodiments, some of the configuration implemented by hardware may be replaced with software, and some or all of the configuration implemented by software may be replaced with hardware. For example, some of the image processing shown in
Although the present disclosure has been described with reference to the exemplary embodiments and the modified embodiments, the embodiments of the present disclosure are provided so as to easily understand the present disclosure, not to limit the present disclosure. The present disclosure can be changed and improved without departing from the spirit thereof, and the present disclosure includes equivalents thereof.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2018-173136 | Sep 2018 | JP | national |
