JP2024076455A - Printing device, printing system, and printing method - Google Patents

Abstract

[Problem] To provide a printing device, printing system, and printing method capable of performing image correction using a comparison pattern while shortening processing time and suppressing cost increases. [Solution] The printing device includes a controller that executes a process of determining whether a dot pattern in a predetermined range including selected dot data matches a predetermined comparison pattern and whether a dot pattern including selected dot data matches a predetermined exclusion pattern, a process of performing a correction to delete the selected dot data included in the dot pattern from the first print data when the determination process determines a first state in which the selected dot pattern does not match the comparison pattern and does not match the exclusion pattern, and a process of ejecting droplets from an ejection head onto a print medium based on second print data obtained by performing the correction on the first print data to form an image on the print medium. [Selected Figure] Figure 7

Description

The present invention relates to a printing device, a printing system, and a printing method.

Conventionally, there is known a printing system that aims to print tables and ruled lines other than barcodes well without reducing the accuracy of reading barcodes. In this case, if the print data is barcode data, the printer driver prints the print data without correcting the print data to thicken the outlines, and if the print data is not barcode data, the printer driver prints the print data after correcting the print data to thicken the outlines.

However, when droplets are ejected onto a print medium to print a barcode, the droplets may bleed onto the print medium. This increases the line width of the barcode, decreasing the accuracy of reading the barcode. A printing device is therefore known that performs correction using multiple comparison patterns, which are comparison dot patterns for dots located at a specific edge of the image to be formed (peripheral dots around the selected dot that is the subject of attention) (see Patent Document 1). In this printing device, when the peripheral dots match dots in each comparison pattern, a correction is performed to make the selected dot that corresponds to the peripheral dot blank data.

JP 2022-084291 A

However, the above-mentioned conventional technology requires multiple comparison patterns, which results in an extremely large number of comparison patterns. This increases the time required for processing and requires high-performance processors and memory, which can lead to increased costs.

The present invention aims to provide a printing device, printing system, and printing method that can perform image correction using a comparison pattern while shortening processing time and preventing costs from increasing.

The printing device of the present invention comprises an ejection head that ejects droplets onto a print medium, and a controller, and the controller performs the following steps: acquire first print data for forming an image including a code having information on the print medium by dots formed by landing the droplets on the print medium; select dot data corresponding to the dots that form the image from the acquired first print data, and determine whether a dot pattern in a predetermined range including selected dot data, which is the selected dot data, matches a predetermined comparison pattern, and whether the dot pattern including the selected dot data matches a predetermined exclusion pattern; and When the first state is determined to be a first state that does not match the comparison pattern and does not match the exclusion pattern, a correction process is performed to delete the selected dot data included in the dot pattern from the first print data; when the second state other than the first state is determined in the determination process, a process is maintained without performing a correction to delete the selected dot data included in the dot pattern from the first print data; and a process is performed to form the image on the print medium by ejecting the droplets from the ejection head onto the print medium based on second print data obtained by performing the correction or the maintenance on the first print data.

According to the present invention, when a dot pattern in a predetermined range including selected dot data is determined to be in a first state in which the dot pattern does not match the comparison pattern and does not match the exclusion pattern, a correction is performed in which the selected dot data included in the dot pattern is deleted from the first print data. In this regard, in the past, in order to ensure many cases in which the selected dot data was corrected, a comparison pattern was required as many times as the number of times it was desired to match the surrounding dot data. In contrast, the present invention is configured to perform correction when the dot pattern does not match the comparison pattern, so that correction is performed if any of the dot data in the dot pattern does not match the comparison pattern. This means that a single comparison pattern is sufficient, not multiple comparison patterns. Therefore, it is possible to avoid the increase in processing time and the increase in costs due to the increase in comparison patterns. Therefore, it is possible to perform image correction using the comparison pattern while shortening the processing time and suppressing the increase in costs. In addition, in the present invention, a correction is performed when the dot pattern does not match the exclusion pattern, so it is possible to avoid the undesired exclusion of selected dot data by correction, which is a drawback of using the comparison pattern.

The present invention provides a printing device, printing system, and printing method that can perform image correction using a comparison pattern while shortening processing time and preventing costs from increasing.

1 is a plan view showing a printing apparatus according to an embodiment of the present invention. FIG. 2 is a bottom view of the ejection head provided in the printing device of FIG. 1 . FIG. 2 is a block diagram showing the configuration of a control system in the printing apparatus of FIG. 1 . FIG. 1 shows an example of an image including an information-carrying code. FIG. 5A shows an image before processing, FIG. 5B shows a comparison between a dot pattern in a specified range including selected dot data and a comparison pattern, and FIG. 5C shows an image after correction has been performed. FIG. 6A is a diagram showing correction for cutting out one dot, FIG. 6B is a diagram showing correction for cutting out two dots, FIG. 6C is a diagram showing correction for cutting out three dots, and FIG. 6D is a diagram showing correction for cutting out four dots. Figure 7A shows the image before processing, Figure 7B shows a comparison between a dot pattern in a specified range including selected dot data and a comparison pattern, Figure 7C shows a comparison between the dot pattern and an exclusion pattern, and Figure 7D shows the image after correction has been performed. FIG. 8A shows the image before processing, FIG. 8B shows a comparison between a specified range of dot patterns including selected dot data and a comparison pattern, and FIG. 8C shows the image that is maintained without correction being performed. Figure 9A shows the image before processing, Figure 9B shows a comparison between a dot pattern in a specified range including selected dot data and a comparison pattern, Figure 9C shows a comparison between the dot pattern and an exclusion pattern, and Figure 9D shows the image that is maintained without correction being performed. 4 is a flowchart showing a printing process. FIG. 11A is a diagram showing a comparison pattern for cutting one dot, FIG. 11B is a diagram showing a comparison pattern for cutting two dots, FIG. 11C is a diagram showing a comparison pattern for cutting three dots, and FIG. 11D is a diagram showing a comparison pattern for cutting four dots. FIG. 12A is a diagram showing a comparison between a dot pattern in a predetermined range including selected dot data and a comparison pattern, and FIG. 12B is a diagram showing an image after correction has been executed. FIG. 13A is a diagram showing a dot pattern and a mask pattern in a specified range including selected dot data, FIG. 13B is a diagram showing a comparison of the dot pattern after mask processing with a comparison pattern, and FIG. 13C is a diagram showing an image maintained without correction. FIG. 14A shows a dot pattern and a mask pattern within a specified range including selected dot data, FIG. 14B shows a comparison of the dot pattern after mask processing with a comparison pattern, and FIG. 14C shows an image after correction has been performed. 1 is a block diagram showing a configuration of a printing system according to an embodiment of the present invention.

The printing device according to an embodiment of the present invention will be described below with reference to the drawings. The printing device described below is merely one embodiment of the present invention. Therefore, the present invention is not limited to the following embodiment, and additions, deletions, and modifications are possible without departing from the spirit of the present invention.

1 is a plan view showing a printing device 10 according to an embodiment of the present invention. FIG. 2 is a bottom view of the ejection head 30 provided in the printing device 10 of FIG. 1. FIG. 3 is a block diagram showing the configuration of a control system in the printing device 10 of FIG. 1. In FIG. 1 and FIG. 2, directions perpendicular to each other are the first direction Ds and the second direction Df. In this embodiment, for example, the second direction Df is the transport direction of the print medium W described later, and the first direction Ds is the extension direction of the line head type ejection head 30 described later. In the following description, Ds is called the extension direction, Df is called the transport direction, one side of the extension direction Ds is the left side, the other side of the extension direction Ds is the right side, one side of the transport direction Df is the front, and the other side of the transport direction Df is the rear. However, the above directions are merely examples and are not limited.

As shown in FIG. 1, the printing device 10 is, for example, an inkjet printer that ejects ink droplets onto a print medium W, which is a print sheet. The printing device 10 includes a housing 11, a platen 12, a conveying device 20, one or more (for example, four) ejection heads 30, a tank 13, and a controller 40. The ejection head 30 is, for example, a line head.

The housing 11 houses the platen 12, the transport device 20, the ejection head 30, the tank 13, and the controller 40. The platen 12 has a flat upper surface on which the print medium W is placed.

The transport device 20 has a pair of transport rollers 21 and a transport motor 22 (Figure 3). The pair of transport rollers 21 are arranged in the transport direction Df to sandwich the ejection head 30 between them, and are aligned parallel to each other with their central axes extending in the extension direction Ds. The transport motor 22 is connected to the transport rollers 21 and rotates the transport rollers 21 to transport the print medium W forward.

The ejection heads 30 are fixed to the housing 11 and are, for example, rectangular in shape, with dimensions in the extension direction Ds longer than the dimensions of the print medium W. The lower surfaces of the ejection heads 30 are disposed facing the upper surface of the platen 12. The four ejection heads 30 are aligned in a line in the transport direction Df.

For example, the tanks 13 are provided in the same number as the ejection heads 30, each of which stores a different type of ink, and is connected to the ejection heads 30 by a tube 14. For example, four tanks 13 store cyan, magenta, yellow, and black ink, respectively, and supply ink to the corresponding ejection heads 30 via the tube 14.

As shown in FIG. 2, the ejection head 30 has a holding base 31 and a number of chips 32. The holding base 31 is, for example, rectangular, and holds the chips 32 so that the undersides of the chips 32 are exposed on its underside. Note that only one ejection head 30 is shown in FIG. 2.

The chip 32 has a number of nozzles 33 and driving elements 34 (Figure 3) corresponding to the nozzles 33. The nozzles 33 are connected to the tank 13 via a liquid flow path and a tube 14. The nozzles 33 are arranged, for example, in a row at a predetermined interval from each other in the extension direction Ds to form a nozzle row. In each chip 32, the nozzle rows are arranged in the transport direction Df so that the nozzles 33 are arranged at equal intervals in the extension direction Ds.

The multiple chips 32 are arranged in the extension direction Ds on the holding table 31, and adjacent chips 32 are arranged with a shift in the transport direction Df. Therefore, the multiple chips 32 are arranged in the extension direction Ds so that they are staggered one by one in the transport direction Df. The multiple chips 32 are arranged so that the multiple nozzles 33 are arranged at equal intervals in the extension direction Ds and the total length in the extension direction Ds is longer than the printing medium W.

As shown in FIG. 3, the controller 40 has a calculation unit 41, a memory unit 42, and an interface 43. The controller 40 may be a single controller, or may be composed of multiple controllers.

The interface 43 is connected to an external device B such as a computer, a network, and a recording medium, and receives various data such as print data from the external device B. The print data is data for forming an image including a code having predetermined information on the print medium W by dots formed by landing ink droplets on the print medium W, and includes image data such as raster data. The print data may be data stored in the memory unit 42. The print data may also be binary or higher data for instructing whether or not to eject ink droplets from the ejection head 30. The print data may also be RGB value data before being converted into the binary or higher data.

The memory unit 42 is a storage medium accessible by the calculation unit 41, and is composed of, for example, a RAM and a ROM. The RAM temporarily stores various data. Examples of this data include print data and data converted by the calculation unit 41. The ROM stores programs for performing various processes, as well as a comparison pattern Pc, an exclusion pattern Pe, and a mask pattern Pm, which will be described later. Note that the programs may be stored in a storage medium other than the memory unit 42.

The calculation unit 41 is composed of, for example, a processor such as a CPU and an integrated circuit such as an ASIC. The calculation unit 41 controls the drive element 34 and the conveying motor 22 by executing a program stored in the ROM.

The controller 40 is connected to the drive element 34 via the head drive circuit 44, and outputs a control signal based on the print data to the head drive circuit 44. The head drive circuit 44 generates a drive signal based on the control signal and outputs it to the drive element 34. This causes the drive element 34 to drive in response to the drive signal, and pressure is applied to the ink in the flow path connected to the nozzle 33, causing ink droplets to be ejected from the nozzle 33 onto the print medium W.

The controller 40 is connected to the transport motor 22 via the transport drive circuit 45, and outputs a control signal based on the print data to the transport drive circuit 45. The transport drive circuit 45 outputs a drive signal generated based on this control signal to the transport motor 22. This controls the drive timing, rotation speed, rotation amount, etc. of the transport motor 22, and transports the print medium W forward in the transport direction Df.

The controller 40 executes a printing process that prints an image on the print medium W based on the print data. In this printing process, the controller 40 performs an ejection operation that drives the drive element 34 to eject ink droplets from the nozzle 33 based on the print data, and a transport operation that drives the transport motor 22 to transport the print medium W forward in the transport direction Df. As a result, the ink droplets ejected from the nozzle 33 land on the print medium W, and the ink droplets form dots on the print medium W. An image is formed on the print medium W by a collection of these dots.

Figure 4 is a diagram showing an example of an image G including a code C having information. The image G is formed by one or more dots, and includes the code C as shown in Figure 4. The controller 40 executes a process of acquiring print data (hereinafter referred to as the first print data) for forming an image G including the code C as shown in Figure 4 on the print medium W by dots formed by landing ink droplets on the print medium W, for example, from an external device B. The first print data may be input by a user using an input device 15 such as a keyboard and a mouse provided in the printing device 10. In Figure 4, an embodiment is shown in which the image G does not include images (e.g., characters and symbols) other than the code C, but the image G may include images other than the code C. The code C is a code for reading information from reflected light, and examples of the code C include one-dimensional codes such as barcodes and two-dimensional codes such as QR codes (registered trademark). A code reader irradiates the code C with light such as infrared light, and the information included in the code C is read from the reflected light.

(Correction process)
Next, correction by pattern matching for suppressing a decrease in the reading accuracy of the code C will be described.

Figure 5A shows image Dg1 before processing, Figure 5B shows a comparison between a dot pattern Pd1 in a predetermined range including selected dot data Dc and a comparison pattern Pc, and Figure 5C shows image Dg1 after correction has been performed. Note that image Dg1 in Figure 5A is an example of a portion of image G including code C described in Figure 4.

The controller 40 selects dot data corresponding to the dots that form the image from the acquired first print data. The controller 40 then executes a process to determine whether or not a dot pattern in a predetermined range that includes the selected dot data, which is the selected dot data, matches a predetermined comparison pattern. If the controller 40 determines in the determination process that the dot pattern does not match the comparison pattern, it performs a correction to delete the selected dot data included in the dot pattern from the first print data, and on the other hand, if it determines that the dot pattern matches the comparison pattern, it performs a process to maintain the selected dot data without performing a correction to delete it from the first print data. This process is the basic correction process in this embodiment. A specific description will be given below with reference to the drawings.

As shown in FIG. 5A, the controller 40 divides the image to be printed based on the first print data into a number of cells in a grid pattern so that one cell corresponds to one dot. The controller 40 then sets dot data "1" to cells whose density in the first print data is equal to or greater than a predetermined value, indicating that a dot will be formed. The cells to which dot data "1" is set are the blackened cells in FIG. 5A, and the same applies to the following figures. On the other hand, the controller 40 sets blank data "0" to cells whose density in the first print data is less than a predetermined value, indicating that a dot will not be formed. The cells to which blank data "0" is set are the unblackened cells in FIG. 5A, and the same applies to the following figures. In the following explanation, for convenience, the position of each cell arranged in a grid pattern will be specified by row and column.

The controller 40 sequentially selects dot data "1" forming the image Dg1 from the multiple cells in the first print data, and extracts a dot pattern of a predetermined range including the selected dot data (selected dot data) Dc. In FIG. 5A, it is assumed that dot data Dc1 in the cell located in the third row and third column is selected as the selected dot data Dc. Also, in FIG. 5A, it is assumed that the dot pattern of the predetermined range is a 3x3 dot pattern Pd1 consisting of the selected dot data Dc and eight dot data surrounding the selected dot data Dc. Note that the predetermined range of the dot pattern extracted based on the selected dot data Dc is arbitrary and can be changed as appropriate.

Next, as shown in FIG. 5B, the controller 40 determines whether the dot pattern Pd1 including the selected dot data Dc matches a predetermined comparison pattern Pc. In FIG. 5B, the dot pattern Pd1 does not match the comparison pattern Pc. In this case, the controller 40 performs a correction to change the dot data Dc1 corresponding to the selected dot data Dc to blank data Dca1 as shown in FIG. 5C in order to delete the selected dot data Dc from the first print data. Note that in the comparison pattern Pc and the exclusion pattern Pe described below, dot data "1" indicates the formation of a dot, and blank data "0" indicates the non-formation of a dot. Also, the reference symbol Pdh1 in FIG. 5C indicates the image after correction. In this way, in this embodiment, correction is performed when the dot pattern Pd1 does not match the comparison pattern Pc.

Figure 6A shows the correction for removing one dot, Figure 6B shows the correction for removing two dots, Figure 6C shows the correction for removing three dots, and Figure 6D shows the correction for removing four dots.

The correction for removing one dot is a correction for making the dot data Dk of each cell in one row in the conveying direction Df of the image Dg2 blank data, and making the dot data Dk of each cell in one outer column in the extension direction Ds of the image Dg2 blank data. To give a specific example, in the correction for removing one dot, for example, in the image Dg2 before processing in FIG. 6A, the dot data Dk of each cell in the row behind in the conveying direction Df (the second row in FIG. 6A) and the column to the left in the extension direction Ds (the second column in FIG. 6A) is made blank data. Therefore, for example, it is possible to make the dot data Dk of each cell in the row ahead in the conveying direction Df (the seventh row in FIG. 6A) and the column to the right in the extension direction Ds (the seventh column in FIG. 6A) blank data. In addition, the correction for removing two dots is a correction for making the dot data Dk of each cell constituting the outer periphery of the image Dg2 before processing in FIG. 6B blank data.

The correction for three-dot cutting is a correction in which the dot data Dk of each cell in one row on one side and two rows on the other side in the conveying direction Df of the image Dg2 is made blank data, and the dot data Dk of each cell in one column on one side and two columns on the other side in the extension direction Ds of the image Dg2 is made blank data. To give a specific example, in the correction for three-dot cutting, in the image Dg2 before processing in FIG. 6C, for example, the dot data Dk of each cell in the two rows on the rear side in the conveying direction Df (the second and third rows in FIG. 6C) and the one row on the front side (the seventh row in FIG. 6C) is made blank data. In addition, in the correction for three-dot cutting, for example, the dot data Dk of each cell in the two columns on the left side in the extension direction Ds (the second and third columns in FIG. 6C) and the one column on the right side (the seventh column in FIG. 6C) is made blank data. In addition, the correction for removing 4 dots is a correction in which, in the image Dg2 after the correction for removing 2 dots, the dot data Dk of each cell that makes up the outer edge of the image Dg2 is made blank data, as shown in FIG. 6D.

Next, FIG. 7A shows image Dg2 before processing, and FIG. 7B shows a comparison between a dot pattern Pd2 in a predetermined range including selected dot data Dc and a comparison pattern Pc. Also, FIG. 7C shows a comparison between dot pattern Pd2 and an exclusion pattern Pe, and FIG. 7D shows image Dg2 after correction has been performed. Note that image Dg2 in FIG. 7A is an example of a portion of image G including code C described in FIG. 4.

Here, in addition to comparing the dot pattern Pd2 with the comparison pattern Pc, a comparison between the dot pattern Pd2 and the exclusion pattern Pe will be described. As mentioned in FIG. 5, the basic correction process is to perform correction when the dot pattern Pd1 and the comparison pattern Pc do not match, but correction is performed when the dot pattern Pd2 and the comparison pattern Pc do not match, and the dot pattern Pd2 and the exclusion pattern Pe do not match (hereinafter, this case will be referred to as the first state ST1). A specific explanation will be given below.

As shown in FIG. 7A, the dot data Dc2 in the cell located in the sixth row and third column is selected as the selected dot data Dc. Also, in FIG. 7A, the dot pattern of the specified range is the 3×3 dot pattern Pd2 consisting of the selected dot data Dc and eight dot data surrounding the selected dot data Dc.

As in the case of FIG. 5B, the controller 40 determines whether the dot pattern Pd2 including the selected dot data Dc in FIG. 7B matches the comparison pattern Pc. In FIG. 7B, the dot pattern Pd2 does not match the comparison pattern Pc (first result). Then, as shown in FIG. 7C, the controller 40 determines whether the dot pattern Pd2 matches a predetermined exclusion pattern Pe. In FIG. 7C, the dot pattern Pd2 does not match the exclusion pattern Pe (second result). Therefore, based on the first and second results, the controller 40 determines that the first state ST1 is established. In this case, the controller 40 corrects the dot data Dc2 corresponding to the selected dot data Dc to blank data Dca2 as shown in FIG. 7D in order to delete the selected dot data Dc from the first print data. Note that the reference symbol Pdh2 in FIG. 7D indicates the image after correction.

In contrast, if the controller 40 determines that the second state ST2, which is a state other than the first state ST1, exists, it executes the following process.

Figure 8A shows image Dg3 before processing, Figure 8B shows a comparison between a dot pattern Pd3 of a specified range including selected dot data Dc and a comparison pattern Pc, and Figure 8C shows image Dg3 that has been maintained without correction. Note that image Dg3 in Figure 8A is the same as image Dg2 in Figure 7A.

As shown in FIG. 8A, the dot data Dc3 in the cell located in the fifth row and fourth column is selected as the selected dot data Dc. Also, in FIG. 8A, the dot pattern of the specified range is the 3×3 dot pattern Pd3 consisting of the selected dot data Dc and eight dot data surrounding the selected dot data Dc.

As in the case of FIG. 7B, the controller 40 determines whether the dot pattern Pd3 including the selected dot data Dc in FIG. 8B matches the comparison pattern Pc. In FIG. 8B, the dot pattern Pd3 matches the comparison pattern Pc. Therefore, the controller 40 determines that the second state ST2 other than the first state ST1 exists. In this case, the controller 40 performs processing to maintain the dot data Dc3 corresponding to the selected dot data Dc included in the dot pattern Pd3 as shown in FIG. 8C without making a correction to delete it from the first print data.

Another example of the second state ST2 will be described. Fig. 9A shows the image Dg4 before processing, and Fig. 9B shows a comparison between a dot pattern Pd4 of a predetermined range including the selected dot data Dc and a comparison pattern Pc. Fig. 9C shows a comparison between the dot pattern Pd4 and an exclusion pattern Pe, and Fig. 9D shows the image Dg4 that has been maintained without correction being performed.

As shown in FIG. 9A, the dot data Dc4 in the cell located in the fifth row and third column is selected as the selected dot data Dc. Also, in FIG. 9A, the dot pattern of the specified range is a 3×3 dot pattern Pd4 consisting of the selected dot data Dc and eight dot data surrounding the selected dot data Dc.

As in the case of FIG. 7B, the controller 40 determines whether or not the dot pattern Pd4 including the selected dot data Dc in FIG. 9B matches the comparison pattern Pc. In FIG. 9B, the dot pattern Pd4 does not match the comparison pattern Pc (third result). Then, as shown in FIG. 9C, the controller 40 determines whether or not the dot pattern Pd4 matches the specified exclusion pattern Pe. In FIG. 9C, the dot pattern Pd4 matches the exclusion pattern Pe (fourth result). Therefore, based on the third and fourth results, the controller 40 determines that the second state ST2 other than the first state ST1 exists. In this case, as in FIG. 8C, the controller 40 performs processing to maintain the dot data Dc4 corresponding to the selected dot data Dc included in the dot pattern Pd4 as shown in FIG. 9D without making a correction to delete it from the first print data.

As described above, the controller 40 determines whether the first state ST1 or the second state ST2 exists, and determines whether correction is required depending on the result of the determination. The controller 40 then executes a process of ejecting ink droplets from the ejection head 30 onto the print medium W based on the second print data obtained by performing the correction or maintenance described above on the first print data, thereby forming an image on the print medium W.

Figure 10 is a flowchart showing the printing process. As shown in Figure 10, first, the controller 40 acquires first print data for forming an image G including a code C on a print medium W from an external device B or an input device 15 (step S1). Next, the controller 40 acquires a dot pattern of a predetermined range (e.g., 3 x 3 with the selected dot data Dc at the center) including the selected dot data Dc (step S2). Then, the controller 40 determines whether the acquired dot pattern matches the comparison pattern Pc (step S3).

If the dot pattern does not match the comparison pattern Pc (No in step S3), the controller 40 determines whether the dot pattern matches the exclusion pattern Pe (step S4). If the dot pattern does not match the exclusion pattern Pe (No in step S4), the controller 40 determines that the first state ST1 is established, and performs a correction to change the dot data corresponding to the selected dot data Dc to blank data in order to delete the selected dot data Dc from the first print data (step S5).

On the other hand, if the dot pattern matches the comparison pattern Pc (Yes in step S3), or if the dot pattern does not match the comparison pattern Pc but matches the exclusion pattern Pe (Yes in step S4), the controller 40 determines that the second state ST1 is established. In this case, the controller 40 maintains the selected dot data Dc without deleting it from the first print data (step S7).

After the processing of step S5 and after the processing of step S7, the controller 40 executes a process of forming an image on the printing medium W based on the second printing data obtained by correcting or maintaining the first printing data (step S6).

(Mask processing)
The mask processing executed in this embodiment will be described below. FIG. 11A is a diagram showing a comparison pattern Pc1 for 1-dot cutting, FIG. 11B is a diagram showing a comparison pattern Pc2 for 2-dot cutting, FIG. 11C is a diagram showing a comparison pattern Pc3 for 3-dot cutting, and FIG. 11D is a diagram showing a comparison pattern Pc4 for 4-dot cutting. The comparison pattern Pc1 has a size of 2×2, the comparison pattern Pc2 has a size of 3×3, the comparison pattern Pc3 has a size of 4×4, and the comparison pattern Pc4 has a size of 5×5. Such comparison patterns Pc1 to Pc4 are different for each type of print medium W. That is, the comparison pattern Pc used differs depending on the type of print medium W. For example, for a print medium W where a lot of ink droplets are smeared, it is preferable to increase the amount of cutting by each dot cutting (hereinafter referred to as the correction amount), so that the comparison pattern Pc4 of FIG. 11D can be used.

In the above-mentioned correction process, a comparison pattern Pc according to the correction amount described in FIG. 6 is required. The comparison pattern Pc used in the correction for 1 dot removal is, for example, the 2×2 comparison pattern Pc1 shown in FIG. 11A. The comparison pattern Pc used in the correction for 2 dot removal is, for example, the 3×3 comparison pattern Pc2 shown in FIG. 11B, and the comparison pattern Pc used in the correction for 3 dot removal is, for example, the 4×4 comparison pattern Pc3 shown in FIG. 11C. The comparison pattern Pc used in the correction for 4 dot removal is, for example, the 5×5 comparison pattern Pc4 shown in FIG. 11D. In this embodiment, 4 dot removal is exemplified as the maximum correction amount, but this is not limited to this, and the correction amount of 5 dot removal or more may be the maximum. The reference symbol Dp in FIGS. 11A to 11D is the dot data on the comparison pattern Pc1 corresponding to the selected dot data Dc. As described above, since the size of the area to be compared varies based on the correction amount, multiple comparison patterns Pc are required. Therefore, there is room for reducing the amount of calculation.

Therefore, in this embodiment, the comparison pattern Pc is standardized as follows: Figure 12A shows a comparison between a dot pattern Pd5 in a predetermined range that includes the selected dot data Dc and a comparison pattern Pc5, and Figure 12B shows an image after correction has been performed.

Here, the range of the dot pattern Pd5 to be acquired can be, for example, 7x7 as shown in FIG. 12A, in accordance with the size of the comparison pattern Pc4 shown in FIG. 11D (i.e., the size of the area to be compared) being 5x5. In this case, the size of the comparison pattern Pc5 (i.e., the size of the area to be compared) is set to 7x7 to match the size of the dot pattern Pd5, even when, for example, two dots are removed. This is different from the comparison pattern Pc2 in FIG. 11B, even though the same two dots are removed. This allows the comparison pattern Pc to be standardized without the size of the area to be compared being different based on the correction amount. Note that in the dot pattern Pd5 in FIG. 12A, the dot data Dc5 in the cell located in the fourth row and fourth column is selected as the selected dot data Dc.

However, when performing corrections with a small correction amount such as removing two dots as shown in FIG. 12A, using a comparison pattern Pc5 with a large comparison area of 7×7 may prevent the process from being performed properly. To explain in detail, if the dot pattern Pd5 including the selected dot data Dc in FIG. 12A is compared with the comparison pattern of a comparison area of 3×3 when removing two dots, the dot pattern Pd5 matches the comparison pattern Pc. In this case, no correction is performed to make the selected dot data Dc blank data. In contrast, when the dot pattern Pd5 is compared with the comparison pattern Pc5 of the comparison area of 7×7 in FIG. 12A, the dot pattern Pd5 does not match the comparison pattern Pc5. In this case, as shown in FIG. 12B, the dot data Dc5 corresponding to the selected dot data Dc is corrected to blank data Dca5, which is a problem. Therefore, the following mask processing is performed.

Figure 13A shows a dot pattern Pd6 of a predetermined range including selected dot data Dc and a mask pattern Pm, Figure 13B shows a comparison between the dot pattern Pma after mask processing and the comparison pattern Pc6, and Figure 13C shows an image maintained without correction. Also, Figure 14A shows a dot pattern Pd7 of a predetermined range including selected dot data Dc and a mask pattern Pm, Figure 14B shows a comparison between the dot pattern Pma after mask processing and the comparison pattern Pc7, and Figure 14C shows an image after correction has been performed.

The dot pattern Pd6 shown in FIG. 13A is the same as the dot pattern Pd5 in FIG. 12A. In the dot pattern Pd6 in FIG. 13A, the dot data Dc6 in the cell located in the fourth row and fourth column is selected as the selected dot data Dc. In addition, the comparison pattern Pc6 shown in FIG. 13B is the same as the comparison pattern Pc5 in FIG. 12A.

Mask pattern Pm has a size of 7x7, the same as dot pattern Pd6. In mask pattern Pm, dot data "1" is set for cells based on selected dot data Dc, and blank data "0" is set for the remaining cells, based on the desired amount of correction. Specifically, if the desired amount of correction is, for example, shaving off 2 dots, in mask pattern Pm of FIG. 13A, dot data "1" is set for 3x3 cells based on the dot data corresponding to selected dot data Dc of dot pattern Pd6, and blank data "0" is set for the remaining cells.

The controller 40 executes a process of masking the dot pattern Pd6 with the mask pattern Pm. This mask process generates a dot pattern Pma in which blank data "0" is set for the remaining cells of the dot pattern Pd6, except for the cases in which dot data "1" is set for cells of the dot pattern Pd6 corresponding to cells in the mask pattern Pm in which dot data "1" is set. In the example of FIG. 13A, dot data "1" is set for all cells of the dot pattern Pd6 corresponding to cells in the mask pattern Pm in which dot data "1" is set. Therefore, in the generated dot pattern Pma, blank data "0" is set for all cells except the 3x3 cells in which dot data "1" is set.

The controller 40 determines whether the dot pattern Pma matches the comparison pattern Pc6, as shown in FIG. 13B. In FIG. 13B, the dot pattern Pma matches the comparison pattern Pc6. In this case, the controller 40 performs processing to maintain the dot data Dc6 corresponding to the selected dot data Dc included in the dot pattern Pd6 as shown in FIG. 13C, without making a correction to delete the dot data Dc6 from the first print data.

In contrast, in the example shown in FIG. 14A, one cell (the cell in the third row and third column) of the multiple cells on dot pattern Pd7 that correspond to the cells on mask pattern Pm to which dot data "1" is set does not have dot data "1" set. Therefore, in the dot pattern Pma in FIG. 14B generated by mask processing, blank data "0" is set to the cell corresponding to the cell in the third row and third column of dot pattern Pd7 and to the remaining cells excluding the eight cells to which dot data "1" is set.

The controller 40 determines whether the dot pattern Pma matches the comparison pattern Pc7, as shown in FIG. 14B. In FIG. 14B, the dot pattern Pma does not match the comparison pattern Pc6. In this case, the controller 40 generates an image Pdh7 by correcting the dot data Dc7 corresponding to the selected dot data Dc to blank data Dca7, as shown in FIG. 14C, in order to delete the selected dot data Dc from the first print data.

As described above, according to the printing device 10 of this embodiment, when the dot pattern Pd2 in a predetermined range including the selected dot data Dc is determined to be in the first state ST1 in which the dot pattern Pd2 does not match the comparison pattern Pc and does not match the exclusion pattern Pe, the selected dot data Dc is deleted from the first print data for correction. In this respect, in the past, in order to ensure many cases of correcting the selected dot data, a comparison pattern was required as many times as the number of surrounding dot data present around the selected dot data that was to be matched. In contrast, in this embodiment, a correction is performed when the dot pattern Pd2 does not match the comparison pattern Pc, so that correction is performed if any of the dot data in the dot pattern Pd2 does not match the comparison pattern Pc. As a result, a single comparison pattern Pc is sufficient instead of multiple comparison patterns Pc for the same correction amount. Therefore, it is possible to avoid the time required for processing being longer and the cost increasing due to the increase in the comparison pattern Pc. Therefore, it is possible to perform image correction using the comparison pattern Pc while shortening the processing time and suppressing the cost increase. In addition, because correction is performed when the dot pattern Pd2 does not match the exclusion pattern Pe, it is possible to avoid the undesired exclusion of the selected dot data Dc due to correction, which is a drawback of using the comparison pattern Pc.

In addition, in this embodiment, for the selected dot data Dc contained in the dot pattern Pd3 that is determined to match the comparison pattern Pc, the second state ST2 other than the first state ST1 is established, and the data is maintained without being corrected to be deleted from the first print data. This makes it possible to clearly define the cases in which the data is maintained without being corrected.

In addition, in this embodiment, for the selected dot data Dc included in the dot pattern Pd4 that is determined not to match the comparison pattern Pc but to match the exclusion pattern Pe, the second state ST2 other than the first state ST1 is determined to be established, and the data is maintained without being corrected to be deleted from the first print data. This makes it possible to clearly define the cases in which the data is maintained without being corrected.

In addition, in this embodiment, the comparison pattern Pc is different for each type of print medium W. That is, the comparison pattern Pc used differs depending on the type of print medium W. This makes it possible to use a comparison pattern that can increase the correction amount, which is the amount of scraping, for a print medium W that suffers from a lot of ink droplet bleeding, for example.

Furthermore, in this embodiment, in order to avoid the above-mentioned drawbacks caused by standardizing the size of the comparison pattern Pc (the size of the area to be compared), a masking process is performed by the controller 40. This makes it possible to prevent the selected dot data Dc from being undesirably corrected to blank data.

(Modification)
The present invention is not limited to the above-described embodiment, and various modifications are possible without departing from the spirit and scope of the present invention. For example, the following modifications are possible.

The processing performed by the printing device 10 in the above embodiment may be divided between the computer 51 and the printing device 10 in the printing system 50 described below. Figure 15 is a block diagram showing the configuration of a printing system 50 according to one embodiment of the present invention.

As shown in FIG. 15, the printing system 50 includes a computer 51 and a printing device 10. The computer 51 includes a first controller 52. The printing device 10 includes a head 30 that ejects ink droplets onto a print medium W, and a second controller 46. The first controller 52 acquires first print data for forming an image G including a code C having information on the print medium W by dots formed by landing ink droplets on the print medium W. The first controller 52 determines whether a dot pattern of a predetermined range including the selected dot data Dc matches a predetermined comparison pattern Pc in the acquired first print data, and whether a dot pattern of a predetermined range including the selected dot data Dc matches a predetermined exclusion pattern Pe. When the first controller 52 determines in the above determination process that the first state ST1 does not match the comparison pattern Pc and does not match the exclusion pattern Pe, the first controller 52 performs a correction to delete the selected dot data Dc included in the dot pattern from the first print data. On the other hand, when the first controller 52 determines in the above determination process that the second state ST2 is other than the first state ST1, it maintains the first print data without making a correction to delete the selected dot data Dc included in the dot pattern from the first print data. Then, the second controller 46 ejects ink droplets from the ejection head 30 onto the print medium W based on the second print data obtained by correcting or maintaining the first print data, thereby forming an image on the print medium W.

The first controller 52 has a first calculation unit 53, a first memory unit 54, and a first interface 55. The first interface 55 is connected to the printing device 10 and transmits second print data to the printing device 10. The first memory unit 54 is accessible by the first calculation unit 53 and is composed of, for example, RAM and ROM. The first calculation unit 53 performs processing similar to that performed by the calculation unit 41, and transmits the second print data to the printing device 10 via the first interface 55.

The second controller 46 has a second calculation unit 47, a second memory unit 48, and a second interface 49. The second interface 49 receives the second print data sent from the computer 51. The second calculation unit 47 executes a program stored in the second memory unit 48 to perform printing processing based on the second print data. Note that the functions of the other components in the printing device 10 in FIG. 15 are the same as the functions of the components with the same reference numerals in the printing device 10 in FIG. 3 described above, and therefore will not be described here.

In addition, in the above embodiment, the ejection head 30 is a line head, but this is not limited to this. The printing device 10 may be equipped with a carriage on which the ejection head 30 is mounted, and a serial head method may be used in which the carriage moves the ejection head 30 in the extension direction Ds.

In addition, in the above embodiment, the printing device 10 does not need to be equipped with a transport device 20 that transports the print medium W in the transport direction Df. In this case, a method in which the ejection head 30 moves relative to the print medium W may be used.

The above description of the embodiment should be construed as merely an example, and is provided for the purpose of teaching those skilled in the art the best mode for carrying out the present invention. The details of the structure and/or function may be substantially changed without departing from the spirit of the present invention.

REFERENCE SIGNS LIST 10 Printing device 30 Discharge head 40 Controller 46 Second controller 50 Printing system 51 Computer 52 First controller C Code Dc Selected dot data G Image Pc Comparison pattern Pd1 to Pd7 Dot pattern Pe Exclusion pattern Pm Mask pattern ST1 First state ST2 Second state W Printing medium

Claims (7)

An ejection head that ejects droplets onto a print medium;
A controller,
The controller:
A process of acquiring first print data for forming an image including a code having information on the print medium by dots formed by landing the droplets on the print medium;
a process of selecting dot data corresponding to dots forming the image from the acquired first print data, and determining whether a dot pattern in a predetermined range including selected dot data, which is the selected dot data, matches a predetermined comparison pattern, and whether the dot pattern including the selected dot data matches a predetermined exclusion pattern;
a correction process for deleting the selected dot data included in the dot pattern from the first print data when the determining process determines that the first state is a state in which the selected dot data does not match the comparison pattern and does not match the exclusion pattern;
a process of maintaining the selected dot data included in the dot pattern without performing correction to delete the selected dot data from the first print data when the process of determining determines that the selected dot data is a second state other than the first state;
A printing device that executes a process of ejecting the droplets from the ejection head onto the printing medium based on second printing data obtained by performing the correction or maintenance on the first printing data to form the image on the printing medium. The printing device according to claim 1, wherein the maintaining process includes a process of maintaining the selected dot data included in the dot pattern determined to match the comparison pattern without performing a correction to delete the selected dot data from the first print data. The printing device according to claim 1, wherein the maintaining process includes a process of maintaining the selected dot data included in the dot pattern that is determined not to match the comparison pattern and to match the exclusion pattern without performing a correction to delete the selected dot data from the first print data. The printing device according to claim 1, wherein the comparison pattern is different for each type of printing medium. The controller:
further performing a process of masking the dot pattern with a predetermined mask pattern;
The printing device according to claim 1 , wherein in the determining process, the dot pattern after the masking process is used as the dot pattern to be compared with the comparison pattern to see whether it matches. A printing system including a computer and a printing device,
The computer includes a first controller,
The printing device includes an ejection head that ejects droplets onto a print medium, and a second controller.
The first controller is
A process of acquiring first print data for forming an image including a code having information on the print medium by dots formed by landing the droplets on the print medium;
a process of selecting dot data corresponding to dots forming the image from the acquired first print data, and determining whether a dot pattern in a predetermined range including selected dot data, which is the selected dot data, matches a predetermined comparison pattern, and whether the dot pattern including the selected dot data matches a predetermined exclusion pattern;
a correction process for deleting the selected dot data included in the dot pattern from the first print data when the determining process determines that the first state is a state in which the selected dot data does not match the comparison pattern and does not match the exclusion pattern;
a process of maintaining the selected dot data included in the dot pattern without performing correction to delete the selected dot data from the first print data when the process of determining determines that the selected dot data is a second state other than the first state;
The second controller is
A printing system that performs a process of forming the image on the printing medium by ejecting the droplets from the ejection head onto the printing medium based on second printing data obtained by performing the correction or maintenance on the first printing data. acquiring first print data for forming an image including a code having information on a print medium by dots formed by landing droplets on the print medium;
In the acquired first print data, select dot data corresponding to dots forming the image, and determine whether or not a dot pattern in a predetermined range including selected dot data, which is the selected dot data, matches a predetermined comparison pattern, and whether or not the dot pattern including the selected dot data matches a predetermined exclusion pattern;
When the determination results in a first state in which the selected dot data does not match the comparison pattern and does not match the exclusion pattern, a correction is performed to delete the selected dot data included in the dot pattern from the first print data.
When the determination results in a second state other than the first state, the selected dot data included in the dot pattern is maintained without being corrected by deleting the selected dot data from the first print data;
A printing method comprising: ejecting the droplets from an ejection head onto the print medium based on second print data obtained by performing the correction or maintenance on the first print data, thereby forming the image on the print medium.

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