LIQUID EJECTION APPARATUS, LIQUID EJECTION METHOD, AND PROGRAM

Abstract

To optimize a size of discharged liquid based on a test pattern.SOLUTION: A liquid discharge device comprises: a discharge part that discharges liquid to a recording medium to form a test pattern; a control part that makes the discharge part discharge liquid in accordance with drive waveforms; an input part that inputs the plurality of drive waveforms; an obtaining part that obtains first data showing a reference pattern which corresponds to the drive waveforms and is formed when using the drive waveforms, or showing a parameter of the reference pattern; a reading part that reads the test pattern to generate second data; a comparing part that compares the second data with the first data; and a selecting part that selects the drive waveform in which a difference between the second data and the first data becomes minimum based on a comparison result by the comparing part.SELECTED DRAWING: Figure 11

Description

[Technical field]

[0001] The present invention relates to a liquid ejection apparatus, a liquid ejection method, and a program. [Background technology]

[0002] 2. Description of the Related Art Techniques for forming images by ejecting liquid such as ink from an inkjet head are known.

[0003] Specifically, first, the inkjet recording device prints dots at a predetermined pitch to create a test pattern. Then, the inkjet recording device measures the density of the dots. Next, based on the results of this measurement, the inkjet recording device determines the type of recording medium. In this way, a technique for forming a test pattern and accurately determining the type of recording medium is known (see, for example, Patent Document 1). Summary of the Invention [Problem to be solved by the invention]

[0004] The technology disclosed in Patent Document 1 is only capable of identifying the type of recording medium using a test pattern. Therefore, there is a problem in that the size of the ejected liquid is not optimal based on the result of determining the type of recording medium alone.

[0005] An object of the present invention is to optimize the size of the ejected liquid based on a test pattern. [Means for solving the problem]

[0006] In order to solve the above problems, a liquid ejection device according to one aspect of the present invention comprises: a discharge unit that discharges liquid onto a recording medium to form a test pattern; A control unit that causes the ejection unit to eject the liquid in response to a drive waveform; an input unit for inputting a plurality of the driving waveforms; an acquisition unit that acquires first data that corresponds to the drive waveform and indicates a reference pattern that is formed when the drive waveform is used, or that indicates a parameter of the reference pattern; a reading unit that reads the test pattern and generates second data; a comparison unit that compares the second data with the first data; a selection unit that selects the driving waveform that minimizes a difference between the second data and the first data based on a comparison result by the comparison unit; The present invention is characterized by comprising: Effect of the Invention

[0007] According to the present invention, the size of the ejected liquid can be optimized based on the test pattern. [Brief description of the drawings]

[0008] [Figure 1] FIG. 1 is a diagram illustrating an example of the overall configuration of a liquid ejection device. [Diagram 2] FIG. 1 is a diagram illustrating an example of connection of information processing devices and the like. [Diagram 3] FIG. 2 is a diagram illustrating an example of a hardware configuration of an information processing device. [Figure 4] FIG. 13 is a diagram illustrating an example of the overall process. [Diagram 5] FIG. 2 is a diagram showing an example of input of a plurality of driving waveforms 100, etc. [Figure 6] FIG. 2 is a diagram showing an example of a test pattern 102. [Figure 7] FIG. 13 illustrates an example of comparison and selection. [Figure 8] FIG. 11 is a diagram illustrating an example of generation of second data. [Figure 9] FIG. 13 is a diagram showing an overall configuration of a modified example. [Figure 10] FIG. 2 is a diagram showing an example of a configuration for detecting the position of a recording medium using an image sensor 52. [Figure 11] FIG. 2 is a diagram illustrating an example of a functional configuration. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Hereinafter, specific examples will be described with reference to the accompanying drawings. Note that the embodiment is not limited to the specific examples described below.

[0010] [Example of liquid ejection device] 1 is a diagram showing an example of the overall configuration of a liquid ejection device. Below, an example will be described in which the liquid ejection device is an image forming device 10. In the example described below, the recording medium is a web 206. In the example described below, the liquid ejected by the image forming device 10 is ink.

[0011] Hereinafter, the direction in which the recording medium is transported will be referred to as the "transport direction Y." The transport direction Y is the left-right direction in the diagram. In addition, in the following explanation, the recording medium is transported from "upstream" to "downstream." Therefore, in the diagram, the right side is the upstream and the left side is the downstream. Furthermore, the direction perpendicular to the transport direction Y will be referred to as the "orthogonal direction X." Moreover, the direction perpendicular to the transport direction Y, i.e., the surface of the recording medium, will be referred to as the "vertical direction Z."

[0012] The image forming apparatus 10 forms images by an inkjet method using the heads 210. In the following, an example will be described in which the heads 210 are configured with four heads arranged in this order from upstream to downstream: a K head 210K, a C head 210C, an M head 210M, and a Y head 210Y. Note that the K head 210K, the C head 210C, the M head 210M, and the Y head 210Y may be collectively referred to as the "heads 210".

[0013] The image forming apparatus 10 includes an unwinder 201, a head 210, a drying device 203, a reading device 204, a rewinder 205, a host device 207, an engine 208, and the like.

[0014] The unwinder 201 is a paper feeding device that unwinds and supplies a roll-shaped web 206 .

[0015] The rewinder 205 is a storage device that winds up the web 206 and stores it.

[0016] The web 206 is a long sheet of paper. As shown in the figure, the web 206 is transported from an unwinder 201 on the upstream side to a rewinder 205 on the downstream side. For example, the web 206 is transported by actuators such as transport rollers and mechanical components.

[0017] The head 210 includes a plurality of nozzles, and ejects ink from the nozzles onto the web 206 transported directly below the head 210 to form an image.

[0018] The drying device 203 dries the web 206. For example, the drying device 203 dries the web 206 that comes into contact with a heat drum or the like.

[0019] The reading device 204 is, for example, a scanner, etc. Thus, the reading device 204 photographs the web 206 and generates image data, etc.

[0020] The image forming apparatus 10 may be configured to include devices other than those described above. For example, the image forming apparatus 10 may include a device for forming an image on the back side, a device for performing post-processing, or the like.

[0021] 2 is a diagram showing an example of connections of information processing devices, etc. For example, an engine 208, a display device 209, etc. are connected to a higher-level device 207.

[0022] The higher-level device 207 is, for example, an information processing device having the following hardware configuration.

[0023] 3 is a diagram showing an example of a hardware configuration of an information processing device. For example, the higher-level device 207 includes hardware such as a Central Processing Unit (hereinafter referred to as a "CPU 2071"), a Read Only Memory (hereinafter referred to as a "ROM 2072"), a Random Access Memory (hereinafter referred to as a "RAM 2073"), and a Hard Disk Drive (hereinafter referred to as a "HDD 2074").

[0024] The CPU 2071 is an example of a calculation device and a control device.

[0025] The ROM 2072, the RAM 2073, and the HDD 2074 are examples of storage devices.

[0026] An output device such as a display device 209 is connected to the higher-level device 207 via an interface. In addition, an input device and an external device may be connected to the higher-level device 207 via an interface.

[0027] The display device 209 is an example of an output device that outputs processing results and the like.

[0028] The information processing device is not limited to the hardware configuration shown in the drawing. For example, the information processing device may include an external or internal arithmetic unit, a control unit, a storage unit, an input unit, an output unit, an auxiliary unit, or the like.

[0029] The upper device 207 is a Digital Front End (sometimes called "DFE"). Specifically, the upper device 207 performs Raster Image Processor (RIP) processing and the like. The upper device 207 also generates data for performing image formation (hereinafter referred to as "control data") and the like based on job data and settings in the host device and the like.

[0030] The control data includes information such as a drive waveform selected in a process for adjusting an image, etc. Furthermore, the control data includes information such as the results of adjusting the spacing between nozzle rows, etc. In addition, the control data includes information such as printing conditions including the results of adjusting gradation, etc.

[0031] For example, printing conditions include information such as print format, print type, paper feed information, paper ejection information, recording medium information, order of sides to be printed, recording medium size, image data amount, resolution, gradation, color, and number of pages.

[0032] The engine 208 controls the head 210 and other components based on control data and other data sent from the higher-level device 207 to perform processes such as image formation.

[0033] Note that the image forming apparatus 10 is not limited to the configuration shown in Fig. 1 to Fig. 3. For example, the image forming apparatus 10 may include information processing devices other than those shown above. Therefore, the image forming apparatus 10 may be configured such that a device other than the higher-level device 207 performs processing.

[0034] [Example of overall processing] FIG. 4 is a diagram illustrating an example of the overall process.

[0035] In step S0401, the liquid ejection device receives a plurality of drive waveforms, and ejects liquid based on the drive waveforms input in step S0401.

[0036] In step S0402, the liquid ejection device obtains first data.

[0037] The first data is data that is obtained by forming a pattern in advance using a driving waveform. Hereinafter, the pattern that is formed to obtain the first data is referred to as a "reference pattern."

[0038] Moreover, the dots that make up the reference pattern are referred to as "first dots." Furthermore, the dot diameter of the first dots is referred to as the "first dot diameter."

[0039] For example, the first data is a parameter such as a numerical value indicating the first dot diameter. However, the first data may be in a format other than a numerical value indicating the first dot diameter. For example, the first data may be image data indicating the first dot. Therefore, the first data may be a numerical value input by a user through an input operation, or may be acquired from the analysis results of image analysis performed on a reference pattern. In this way, when image data is used, the first data is obtained by analyzing an image of the first dot indicated by the image data, and the parameters are acquired. Therefore, the first data may be image data indicating a dot to be a "sample", or may be a numerical value input by the user.

[0040] In step S0403, the liquid ejection device ejects liquid onto the recording medium to form a test pattern.

[0041] In step S0404, the liquid ejection apparatus generates second data.

[0042] The second data is data generated based on the results of reading the test pattern formed in step S0403. Hereinafter, the dots constituting the test pattern will be referred to as "second dots." Also, the dot diameter of the second dots will be referred to as "second dot diameter."

[0043] In step S0405, the liquid ejection device compares the first data with the second data.

[0044] In step S0406, the liquid ejection apparatus selects a drive waveform based on the result of the comparison.

[0045] The above processing may be performed after selecting a resolution (i.e., the smallest pixel unit of an image). Then, usable driving waveforms, etc. may be specified according to the resolution. For example, the resolution is selected by a user interface (UI) according to the application, etc.

[0046] Furthermore, the liquid ejection device may correct the distance between nozzle rows, the timing of ejecting liquid, the density, the gradation, or a combination of these. For example, correcting the density can suppress density variations between devices or between the front and back, and can align the density-gradation characteristics.

[0047] To correct the gradation, the liquid ejection device first calculates the density at the nozzle interval. The liquid ejection device then adjusts the density to be the average density. In this way, the liquid ejection device adjusts the density to be less uneven within the head. Alternatively, the liquid ejection device adjusts the gradation value, etc. for each head to reduce color differences, etc. between heads.

[0048] By carrying out the above-mentioned corrections, the liquid ejection apparatus can improve image quality.

[0049] 5 is a diagram showing an example of input of a plurality of drive waveforms 100, etc. Hereinafter, the plurality of drive waveforms 100 will be referred to as a "first drive waveform", a "second drive waveform", and a "third drive waveform".

[0050] Also, in this example, when the first drive waveform is used, the amount of ejected liquid is the smallest, and when the third drive waveform is used, the amount of ejected liquid is the largest.

[0051] Hereinafter, it is assumed that the resolution 101 can be selected from a "first resolution," a "second resolution," and a "third resolution."

[0052] In this example, the first resolution is the highest resolution, and the third resolution is the lowest resolution.

[0053] The test patterns differ depending on the combination of the resolution 101 and the drive waveform 100. As shown in the figure, when three drive waveforms 100 and three resolutions 101 are used, nine results are obtained. Note that the number of drive waveforms 100 and resolutions 101 is not limited to three. Also, the usable drive waveforms 100 may differ depending on the conditions such as the resolution 101.

[0054] [Test pattern example] 6 is a diagram showing an example of the test pattern 102. For example, the test pattern 102 is formed on the web 206 with dot groups, which are collections of second dots for each driving waveform 100. Below, an example will be given in which the test pattern 102 is composed of a "first dot group 1021," a "second dot group 1022," and a "third dot group 1023."

[0055] The first dot group 1021 is a dot group made up of the second dots formed using the first drive waveform.

[0056] The second dot group 1022 is a dot group made up of second dots formed using the second drive waveform.

[0057] The third dot group 1023 is a dot group made up of the second dots formed using the third drive waveform.

[0058] In this way, the test pattern 102 is formed by switching between the multiple driving waveforms 100. Note that the test pattern 102 does not have to be formed in one go by switching between the multiple driving waveforms 100. In other words, the test pattern 102 may be formed by multiple image formations.

[0059] It should be noted that the test pattern 102 is not limited to the configuration shown in the figure. For example, the second dots may be arranged or numbered differently from that shown in the figure. However, it is preferable that the second dots are arranged so as not to overlap with other dots and are arranged regularly. Such a regular arrangement can reduce paper waste.

[0060] It is also preferable that the second dots are formed one by one by each nozzle, which can reduce the influence of variations in the discharge amount in the head and nozzles.

[0061] As described above, after the test pattern 102 is formed, the reading device 204 reads it and generates image data. Next, the reading device 204 analyzes the image data and generates second data. The procedure for generating the second data will be described later.

[0062] 7 is a diagram showing an example of comparison and selection. In the following, the second data is assumed to be dot diameter. In addition, the second data is assumed to be generated separately for each type of recording medium. Specifically, the recording media are assumed to be three types: a first sheet 301, a second sheet 302, and a third sheet 303.

[0063] For example, the first sheet 301 is the recording medium that liquid spreads on most easily among the three types. Meanwhile, the third sheet 303 is the recording medium that liquid spreads on least easily among the three types. The second sheet 302 is a recording medium that is intermediate between the first sheet 301 and the third sheet 303 in terms of ease of liquid spreading.

[0064] When test patterns 102 are formed on these recording media and read, measurement results such as an eleventh measurement result 3011, a twelfth measurement result 3012, a thirteenth measurement result 3013, a twenty-first measurement result 3021, a twenty-second measurement result 3022, a twenty-third measurement result 3023, a thirty-first measurement result 3031, a thirty-second measurement result 3032, and a thirty-third measurement result 3033 are obtained.

[0065] An eleventh measurement result 3011 is a result of measuring the dot diameter of the second dot formed on the first paper 301 using the first driving waveform.

[0066] A twelfth measurement result 3012 is a result of measuring the dot diameter of the second dot formed on the first paper 301 using the second driving waveform.

[0067] A thirteenth measurement result 3013 is a result of measuring the dot diameter of the second dot formed on the first paper 301 using the third driving waveform.

[0068] A twenty-first measurement result 3021 is a result of measuring the dot diameter of the second dot formed on the second paper 302 using the first driving waveform.

[0069] A twenty-second measurement result 3022 is the result of measuring the dot diameter of the second dot formed on the second paper 302 using the second driving waveform.

[0070] A twenty-third measurement result 3023 is a result of measuring the dot diameter of the second dot formed on the second paper 302 using the third driving waveform.

[0071] A thirty-first measurement result 3031 is a result of measuring the dot diameter of the second dot formed on the third paper 303 using the first driving waveform.

[0072] A thirty-second measurement result 3032 is a result of measuring the dot diameter of the second dot formed on the third paper 303 using the second driving waveform.

[0073] A thirty-third measurement result 3033 is a result of measuring the dot diameter of the second dot formed on the third paper 303 using the third driving waveform.

[0074] When the resolution is fixed, the dot diameter is calculated taking the resolution into consideration.

[0075] When the recording medium is one that the liquid easily wets and spreads on, such as the first sheet of paper 301, the liquid easily wets and spreads after landing. Therefore, as shown in the eleventh measurement result 3011 to the thirteenth measurement result 3013, the dot diameter tends to be large. On the other hand, when the recording medium is one that the liquid does not easily wet and spread on, such as the third sheet of paper 303, the liquid does not easily wet and spread after landing. Therefore, as shown in the thirty-first measurement result 3031 to the thirty-third measurement result 3033, the dot diameter tends to be small even if the amount of liquid is large.

[0076] In this way, even if the driving waveform is the same, the dot diameter may differ depending on the type of recording medium, etc. Therefore, the test pattern 102 is read to generate second data indicating the dot diameter, etc.

[0077] The second data is then compared to the first data, which in the illustrated example represents a threshold value 304. For example, the threshold value 304 may be preset.

[0078] In the illustrated example, when the first paper 301 is used, the eleventh measurement result 3011 has the smallest difference from the threshold value 304. Therefore, when the first paper 301 is used, the size is optimal when the first drive waveform is used. Therefore, when the first paper 301 is used, the first drive waveform is selected.

[0079] Similarly, when the second paper 302 is used, the twenty-second measurement result 3022 has the smallest difference from the threshold value 304. Therefore, when the second paper 302 is used, the size is optimal when the second drive waveform is used. Therefore, when the second paper 302 is used, the second drive waveform is selected.

[0080] Furthermore, when the third paper 303 is used, the thirty-third measurement result 3033 has the smallest difference from the threshold value 304. Therefore, when the third paper 303 is used, the size is optimal when the third drive waveform is used. Therefore, when the third paper 303 is used, the third drive waveform is selected.

[0081] In this way, the optimum size is set by acquiring first data such as the threshold value 304. In response to this, the test pattern 102 is generated and read, and the liquid ejection device generates second data. Then, by comparing the first data and the second data, the liquid ejection device can determine the result that is closest to the optimum size. In this way, the liquid ejection device can select a drive waveform that ejects the optimum size.

[0082] [Example of procedure for generating second data] The second data is generated, for example, as follows.

[0083] 8A and 8B are diagrams showing an example of how the second data is generated. First, when the test pattern 102 is read, image data showing the second dots is generated, for example, as shown in Fig. 8A. Next, the liquid ejection device binarizes the image data.

[0084] 8(A), by performing binarization, the liquid ejection device can recognize an area where liquid is applied (hereinafter referred to as "coated area 402") and an area where liquid is not applied (hereinafter referred to as "blank area 401"). Note that in the binarization for recognizing blank area 401 and coated area 402, a threshold value or the like may be set in consideration of the color of the recording medium, the type of liquid, etc.

[0085] The area of ​​the coated region 402 is determined, for example, by a value obtained by counting the pixels that make up the coated region 402 (hereinafter referred to as a "count value"). The area of ​​one pixel is determined, for example, by the resolution. Therefore, the area may be determined by the area per pixel determined by the resolution and the multiplication result of the count value, etc.

[0086] For example, the second data, that is, the dot diameter, may be generated based on the count value or the area.

[0087] Furthermore, the second data may be generated using a circularity that defines the second dot as a perfect circle.

[0088] Fig. 8(B) is a diagram showing an example in which the second dot shown in Fig. 8(A) is made a perfect circle. The second dot may be, for example, an ellipse as shown in Fig. 8(A) and may not be a perfect circle. In such a case, the liquid ejection device may calculate a dot diameter (hereinafter referred to as "third dot diameter 403") assuming that the second dot is a perfect circle. Specifically, the third dot diameter 403 is calculated using the following formula (1) or the like.

[0089] Third dot diameter = √{(4 × area)÷π} (1)

[0090] In the above formula (1), the "area" is the product of the area in pixels determined by the resolution and the count value. In this way, the third dot diameter 403 calculated by the above formula (1) may be used as the second data.

[0091] On the other hand, the second data may be a Feret's diameter (also called a "projected width") calculated based on the binarization result.

[0092] The second data may be a statistical value determined by statistical processing such as averaging. The test pattern 102 is composed of a plurality of second dots as shown in Fig. 6. In such a case, the plurality of second dots are read, and a plurality of read results are obtained.

[0093] For example, the statistical value is an average value, a median value, a maximum value, etc. By using such a statistical value, the influence of uneven dots, etc. can be reduced.

[0094] Furthermore, when performing the statistical processing as described above, the second dots to be subjected to the statistical processing may be selected. For example, a dot with a missing part may be determined as an object to be excluded, and the statistical value may be calculated excluding the second dot determined as an object to be excluded.

[0095] Specifically, first, the circularity of each second dot is calculated. The dots to be excluded are determined by comparing each circularity with a preset value. For example, the circularity is closer to "1" the closer the shape is to a perfect circle. In contrast, the preset value is, for example, 0.5 to 0.6. In such a case, the second dots whose circularity is smaller than the preset value are excluded.

[0096] The roundness may be calculated using the calculation method defined in JIS B 0621-1984.

[0097] Additionally, the objects to be excluded may be second dots or the like that are determined to be abnormal based on the average value ±3σ (where “σ” is the standard deviation).

[0098] As described above, by excluding abnormal dots, even if abnormal dots are included, the liquid ejection device can accurately select a drive waveform that results in an optimal size.

[0099] [Example of liquid ejection system] A liquid ejection system 20 having a liquid ejection device may be configured as follows.

[0100] 9 is a diagram showing the overall configuration of a modified example. For example, a liquid ejection system 20 includes a paper feeder 21, a treatment liquid application device 22, a first inkjet device 23 which is an example of a liquid ejection device, a reversing device 24, and a second inkjet device 25.

[0101] The recording medium is, for example, a continuous roll of paper.

[0102] The paper feeder 21 transports the recording medium to the treatment liquid applicator 22 .

[0103] The treatment liquid application device 22 performs pre-treatment on the recording medium. For example, the treatment liquid application device 22 applies treatment liquid to the front and back of the recording medium.

[0104] The first inkjet device 23 ejects liquid onto a recording medium to form an image, etc. For example, the first inkjet device 23 forms an image indicated by image data on the front surface of the recording medium.

[0105] The reversing device 24 reverses the recording medium.

[0106] The second inkjet device 25 ejects liquid onto a recording medium to form an image, etc. For example, the second inkjet device 25 forms an image indicated by image data on the back surface of the recording medium.

[0107] The liquid ejection system 20 may not necessarily have the configuration as shown in the figure. For example, the liquid ejection system 20 may further include a device that performs pre-processing or post-processing of a type other than that shown in the figure. The liquid ejection system 20 may include one liquid ejection device, or three or more liquid ejection devices.

[0108] [Example of configuration for detecting the position of a recording medium] 10 is a diagram showing an example of a configuration for detecting the position of a recording medium using an image sensor 52. For example, it is desirable for the liquid ejection device to have the following configuration.

[0109] As shown in FIG. 10A, the first inkjet device 23 has a hardware configuration including an image sensor 52.

[0110] The image sensor 52 captures an image of the recording medium being conveyed and generates image data. Specifically, the image sensor 52 captures an image of the front surface of the recording medium at a preset cycle.

[0111] 10(B) is a diagram showing a typical cycle of capturing images by the image sensor 52. Hereinafter, the image data will be referred to as "first image data IMG1", "second image data IMG2", "third image data IMG3", "fourth image data IMG4", ... in the order in which they were captured.

[0112] After that, the first inkjet device 23 performs a frequency analysis process such as FFT (Fast Fourier Transform) on the image data. Using the result of the frequency analysis process, the first inkjet device 23 calculates the peak of image correlation between the two image data.

[0113] Fig. 10C is a diagram showing an example of a frequency analysis result. Specifically, the first inkjet device 23 generates a "first analysis result F12" based on the first image data IMG1 and the second image data IMG2. Similarly, the first inkjet device 23 generates a "second analysis result F23" based on the second image data IMG2 and the third image data IMG3. Next, the first inkjet device 23 generates a "third analysis result F34" based on the third image data IMG3 and the fourth image data IMG4. A peak is calculated in each analysis result.

[0114] Based on the peaks calculated in this way, the first inkjet device 23 calculates the transport amount. Specifically, by comparing the positions at which the peaks occur, the first inkjet device 23 calculates the displacement of the pattern formed on the surface of the recording medium. Based on such a result, the first inkjet device 23 generates a pulse, for example, each time the transport amount reaches a certain amount.

[0115] With this configuration, the first inkjet device 23 can generate signals indicating the displacement, the transport speed, or a combination of these, similar to an encoder roller, etc. Also, with a configuration in which the image sensor 52 detects the position of the recording medium, the work of preparing slits, etc. in advance for the recording medium can be reduced.

[0116] The comparison may be performed by a process other than the above. For example, the comparison may be performed by a judgment of similarity using artificial intelligence (AI). Specifically, the first data is image data showing a reference pattern, etc. On the other hand, the second data is image data obtained by reading the second dots, etc. Then, the AI ​​learns the first data as learning data in advance. In this configuration, the AI ​​can compare the first data and the second data. In other words, the liquid ejection device can use the AI ​​to select a driving waveform that can form dots that are closest to the dots shown by the first data.

[0117] [Example of functional configuration] 11 is a diagram showing an example of a functional configuration of the liquid ejection device, which includes an ejection unit 10F1, a control unit 10F2, an input unit 10F3, an acquisition unit 10F4, a reading unit 10F5, a comparison unit 10F6, and a selection unit 10F7.

[0118] The ejection unit 10F1 performs an ejection procedure for ejecting liquid onto a recording medium to form a test pattern. For example, the ejection unit 10F1 is realized by a head 210 or the like.

[0119] The control unit 10F2 performs a control procedure for causing the ejection unit 10F1 to eject liquid in accordance with a drive waveform. For example, the control unit 10F2 is realized by the engine 208 or the like.

[0120] The input unit 10F3 performs an input procedure for inputting a plurality of drive waveforms. For example, the input unit 10F3 is realized by the higher-level device 207 or the like.

[0121] The acquisition unit 10F4 performs an acquisition procedure for acquiring the first data. For example, the acquisition unit 10F4 is realized by the higher-level device 207 or the like.

[0122] The reading unit 10F5 performs a reading procedure to read the test pattern and generate second data. For example, the reading unit 10F5 is realized by the reading device 204 or the like.

[0123] The comparison unit 10F6 performs a comparison procedure to compare the second data with the first data. For example, the comparison unit 10F6 is realized by the higher-level device 207 or the like.

[0124] The selection unit 10F7 performs a selection procedure for selecting a drive waveform that minimizes the difference between the second data and the first data, based on the comparison result by the comparison unit 10F6. For example, the selection unit 10F7 is realized by the higher-level device 207 or the like.

[0125] For example, in the commercial field, etc., liquid ejection devices are used that have a combination of resolution and transport speed (sometimes called "linear speed") according to the printing application. In such liquid ejection devices, for example, in order to increase productivity, the settings are a fast transport speed and a low resolution. On the other hand, in order to prioritize quality, the settings are a slow transport speed and a high resolution.

[0126] In this way, when there are multiple resolutions, the lower the resolution is, the larger the size of the liquid droplets that the liquid ejection device ejects onto the recording medium in order to fill in the image. Therefore, an optimal size exists for each condition such as resolution.

[0127] If the size is smaller than the optimum size, the image will not be filled sufficiently, resulting in insufficient density for solid areas, etc. On the other hand, if the size is larger than the optimum size, graininess will deteriorate.

[0128] Furthermore, the characteristics of the recording medium differ depending on the type of recording medium, etc. The size is affected by, for example, characteristics such as how easily it spreads while wet, the outside air, or humidity. In particular, the characteristics of the recording medium often have a large effect. Therefore, in order to optimize the size, the liquid ejection device forms a test pattern. By forming the test pattern in this way, the size of the ejected liquid can be optimized.

[0129] When forming an image by discharging liquid, the liquid discharge device can improve image quality by optimizing the size to improve density characteristics or graininess.

[0130] [Other embodiments] The liquid ejection method described above may be realized, for example, by a program. That is, the liquid ejection method is a method executed by a computer by causing an arithmetic unit, a storage device, an input device, an output device, and a control device to cooperate with each other and operate based on the program. The program may be written into a storage device or a storage medium, etc., and distributed, or distributed via a telecommunication line, etc.

[0131] Each of the devices described above does not have to be a single device, that is, each device may be a system made up of multiple devices.

[0132] The image forming apparatus may be, for example, a commercial printing machine (such as a large electrophotographic printer or an inkjet printer).

[0133] The recording medium is, for example, paper (also called "plain paper"). However, the recording medium may be coated paper other than paper, label paper, overhead projector sheet, film, or flexible thin plate. The recording medium may also be roll paper.

[0134] In other words, the material of the recording medium may be a material to which paint such as ink or toner can adhere, can be temporarily adhered, can adhere and stick, or can adhere and penetrate.

[0135] Specifically, the recording medium may be a recording medium such as paper, film, or cloth, an electronic board, an electronic component such as a piezoelectric element (also referred to as a "piezoelectric member"), a powder layer (also referred to as a "powder layer"), an organ model, or a test cell, etc.

[0136] Thus, the material of the recording medium may be any material to which paint can be attached, such as paper, thread, fiber, cloth, leather, metal, plastic, glass, wood, ceramics, or a combination of these.

[0137] Furthermore, the liquid is not limited to ink, and may be any material other than ink as long as it adheres to the recording medium.

[0138] The present invention is not limited to the above-described embodiments, and various modifications are possible without departing from the technical gist of the present invention. The present invention covers all technical matters included in the technical ideas described in the claims. The above-described embodiments are preferred examples, but a person skilled in the art can realize various modifications from the disclosed contents. Such modifications are also included in the technical scope described in the claims. [Explanation of symbols]

[0139] 10: Image forming device 10F1:Discharge part 10F2: Control section 10F3: Input section 10F4: Acquisition section 10F5: Reading section 10F6: Comparison section 10F7: Selection section 20: Liquid ejection system 100: Drive waveform 101: Resolution 102: Test pattern 210: Head 304: Threshold 401: Blank area 402: Application area [Prior art documents] [Patent documents]

[0140] [Patent Document 1] JP 2007-152670 A

Claims

1. a discharge unit that discharges liquid onto a recording medium to form a test pattern; A control unit that causes the ejection unit to eject the liquid in response to a drive waveform; an input unit for inputting a plurality of the driving waveforms; an acquisition unit that acquires first data that corresponds to the drive waveform and indicates a reference pattern that is formed when the drive waveform is used, or that indicates a parameter of the reference pattern; a reading unit that reads the test pattern and generates second data; a comparison unit that compares the second data with the first data; a selection unit that selects the driving waveform that minimizes a difference between the second data and the first data based on a comparison result by the comparison unit; Equipped with The second data is A statistical value including an average value, a median value, or a maximum value obtained by statistically processing a plurality of second dot diameters is shown. Liquid discharge device.

2. The comparison unit is The first data, which is a first dot diameter of a first dot constituting the reference pattern, is input, and the second data, which is a measurement result of a second dot diameter of a second dot constituting the test pattern, is compared with the first data. The liquid ejection device according to claim 1 .

3. The reading unit is generating image data representing the second dots; binarizing the image data to recognize the area where the liquid is applied; The second data is generated based on a count value obtained by counting the pixels constituting the region, a result of measuring the second dot diameter, and a resolution of the image data. The liquid ejection device according to claim 2 .

4. The reading unit is A third dot diameter, which is a dot diameter when the second dot is a perfect circle, is calculated based on the count value to generate the second data. The liquid ejection device according to claim 3 .

5. The circularity of every second dot is calculated; The second data is the statistical value is calculated excluding the second dot determined to be excluded based on the circularity. The liquid ejection device according to claim 1 .

6. A liquid ejection method performed by a liquid ejection device, comprising: a discharge procedure in which a liquid discharge device discharges liquid onto a recording medium to form a test pattern; a control procedure in which the liquid ejection device ejects the liquid in the ejection procedure in response to a drive waveform; an input step of inputting a plurality of the driving waveforms by the liquid ejection device; an acquisition step in which a liquid ejection device acquires first data that corresponds to the drive waveform and indicates a reference pattern that is formed when the drive waveform is used, or that indicates parameters of the reference pattern; a reading step in which the liquid ejection device reads the test pattern to generate second data; a comparison step in which the liquid ejection device compares the second data with the first data; a selection step in which the liquid ejection device selects the drive waveform that minimizes a difference between the second data and the first data based on a comparison result of the comparison step; having The second data is A statistical value including an average value, a median value, or a maximum value obtained by statistically processing a plurality of second dot diameters is shown. Liquid dispensing method.

7. A program for causing a computer to execute the liquid ejection method according to claim 6.

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