Recording apparatus and recording method

Abstract

To accurately calculate a correction value for correcting an impact position with respect to a fabric.SOLUTION: A control part 20 obtains an interval Pc of weaving yarns in a fabric (S110) and changes an interval Pk of ruled lines constituting a ruled line group in a test pattern on the basis of the obtained interval of the weaving yarns (S120). When the interval of the weaving yarns in the fabric and the interval of the ruled lines constituting the ruled line group in the test pattern coincide with each other or are equal to integral multiple, the ruled lines in the test pattern match the interval of the weaving yarns in the fabric. This makes it difficult to distinguish shadow of weaving yarns between in the test pattern and in the fabric. The control part 20 changes the interval of the ruled lines constituting the ruled line group in the test pattern on the basis of the interval of the weaving yarns, thereby avoiding the difficulty in cutting.SELECTED DRAWING: Figure 6

Description

Technical Field

[0001] The present invention relates to a recording apparatus such as a printing apparatus and a recording method.

Background Art

[0002] Patent Document 1 discloses a technique for adjusting the landing position of ink droplets ejected from a liquid ejection device. According to the same Document 1, after printing a test pattern including a predetermined grid line on a recording medium from the liquid ejection device, an image is acquired by an image acquisition means such as an RGB camera, and the acquired image is subjected to image processing to calculate information on the amount of landing deviation, and a correction value for correcting the landing position is calculated.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] The liquid ejection device may print on a fabric as a recording medium. When printing on a raw fabric where the recording medium is a fabric, if the interval between the warp threads of the fabric and the interval between the grid lines of the test pattern are the same or in an integer multiple relationship, it becomes difficult to distinguish the shadows of the grid lines of the test pattern and the warp threads of the fabric, and there is a problem that an appropriate correction value cannot be obtained. The present invention provides a recording apparatus and a recording method capable of accurately calculating a correction value for correcting the landing position with respect to a fabric.

Means for Solving the Problems

[0005] The present invention includes a recording unit capable of recording a test pattern having a group of ruled lines at a predetermined interval on a fabric, and a control unit that controls the recording in the recording unit. The control unit acquires the interval between the warp threads in the fabric and changes the interval between the ruled lines constituting the group of ruled lines in the test pattern based on the acquired interval between the warp threads. In the above configuration, the control unit acquires the interval between the warp threads in the fabric and changes the interval between the ruled lines constituting the group of ruled lines in the test pattern based on the acquired interval between the warp threads. When the interval between the warp threads in the fabric and the interval between the ruled lines constituting the group of ruled lines in the test pattern are the same or an integer multiple, the ruled lines of the test pattern will match the interval between the warp threads in the fabric. If the two match, it becomes difficult to distinguish the shadows of the warp threads in the test pattern and the fabric. By the control unit changing the interval between the ruled lines constituting the group of ruled lines in the test pattern based on the interval between the warp threads, it is also possible to prevent it from becoming difficult to distinguish.

Brief Description of the Drawings

[0006]

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Embodiments for Carrying Out the Invention

[0007] Hereinafter, embodiments of the present invention will be described based on the drawings. FIG. 1 shows a printing apparatus to which a recording apparatus according to an embodiment of the present invention is applied in a schematic block diagram. In the figure, the print head 11 of the printer (recording apparatus) 10 discharges four-color or six-color ink supplied from the ink tank T from nozzles (not shown). Dots are drawn when the color ink adheres to the recording medium G. The print head 11 faces a platen 13 that is rotationally driven by a platen motor 12, and the recording medium G is conveyed intersecting the print head 11. The print head 11 can reciprocate parallel to the platen 13 by a main scanning motor 14. By driving the print head 11 to reciprocate in the X-axis direction and driving the recording medium in the Y-axis direction, the nozzles of the print head 11 can discharge color ink at an arbitrary position with respect to the recording medium surface. The X-axis direction in which the print head 11 reciprocates is called the main scanning direction, and the Y-axis direction in which the recording medium G is driven is called the sub-scanning direction. These print head 11, platen motor 12, platen 13, main scanning motor 14, etc. correspond to the recording unit.

[0008] In this embodiment, a recording apparatus in which the recording medium G is driven by the platen 13 is adopted. However, it may be a flatbed type recording apparatus in which the recording medium G is fixed on a flat plate, the print head 11 is driven in the X-axis direction, and the flat plate is driven in the Y-axis direction. Alternatively, a recording apparatus may be adopted in which a long recording medium G wound in a roll shape around the surface of a hollow cylindrical roller is adhered to the roller surface and the roller rotates to convey the recording medium G while completing the recording process.

[0009] Incidentally, the trajectories of the color inks are affected by the ejection of the color inks while the print head 11 moves, the disturbance of the air flow accompanying the conveyance of the recording medium, and the formation direction of the nozzles, so the landing position may deviate from the original target position. The deviation of this landing position is detected by printing a test pattern including a grid line group on the recording medium and performing image analysis on the printed test pattern.

[0010] FIG. 2 shows a part of the test pattern. The grid lines of the test pattern are drawn by aligning dot-like color inks in a predetermined direction and attaching them. When the trajectories of the color inks ejected from each nozzle deviate, the dots that should be attached in alignment are attached without alignment. However, by acquiring the state as an image and performing image analysis, the deviation of the landing position can be detected. In the test pattern shown in the figure, seven straight lines are drawn in parallel as grid lines in the X-axis direction, and several straight lines are drawn as grid lines in the Y-axis direction. These seven straight grid lines in the X-axis direction and several straight grid lines in the Y-axis direction correspond to the grid line group. Also, the intervals between the seven straight grid lines in the X-axis direction are the same and are the grid line pitch Pk.

[0011] Next, the control unit 20 controls the driving of the platen motor 12, the main scanning motor 14, and the print head 11. The control unit 20 includes main components constituting a computer such as a CPU, ROM, RAM, and IF, and also includes a motor driving unit 21 that outputs driving power to the platen motor 12 and the main scanning motor 14, and a head driving unit 22 that outputs driving power to the driving elements corresponding to the nozzles of the print head 11. Furthermore, it includes a storage 23 that is a non-volatile storage area for storing data such as test patterns.

[0012] In this embodiment, the control unit 20 acquires image data from the outside and calculates a correction value for correcting the deviation of the landing position by analyzing the image data. The image data is acquired by the control unit 20 communicating with an external device via the IF. Of course, the control unit 20 itself may be provided with an imaging element, or an imaging element may be attached to the print head 11, and data may be acquired from the imaging element.

[0013] Figure 3 shows the storage. The storage 23 stores various data. In this embodiment, it stores a plurality of test patterns T1 to Tn (collectively referred to as test pattern T). Each test pattern T is created such that the pitch Pk between the ruled lines described above is different. Since the calculation of the correction value for the landing deviation will be different due to the different pitch Pk between the ruled lines, the details of the calculation method are omitted because they are well-known techniques.

[0014] Figure 4 shows an enlarged view of a part of the fabric. This figure explains the interval between the warp threads. In reality, various patterns where the warp and weft threads intersect can be adopted. Taking the weaving of threads as an example, the warp threads are arranged and set in a predetermined arrangement direction at a certain interval, and the weft threads are appropriately woven in. Here, the interval between the woven threads and the pitch of the woven threads are used in the same meaning. For example, it is the interval between the centers of the threads in the arrangement direction of each thread. Of course, it can also be said to be the interval between the weaves between the threads. At least, it is not the gap itself between the adjacent threads, nor does it indicate the width of the thread. The figure shows the woven thread pitch Pc (which has the same meaning as the weave pitch Pc).

[0015] Figure 5 shows the pitch Pk between the ruled lines and the woven thread pitch Pc when this embodiment is executed. As shown in the figure, by executing this embodiment, the pitch Pk between the ruled lines ≠ the woven thread pitch Pc.

[0016] Figure 6 is a flowchart showing the control program implemented by the control unit. The CPU of the control unit 20 executes a program according to the flowchart shown in the figure. First, in step S100, the CPU acquires image data. The image data is the image data obtained by photographing a fabric which is the recording medium G. In step S110, the CPU acquires the yarn pitch Pc based on the image data. There are various methods for acquiring the yarn pitch Pc. Pixel data in the arrangement direction of the yarns in the image data is acquired, subjected to a fast Fourier transform, and the frequency distribution is obtained. Although there are various frequency components in the fabric image, since the arrangement of the yarns is regular at a fixed interval, it is presumed that the frequency component will be large. Therefore, a frequency with a large frequency component value compared to a predetermined threshold is used as a candidate, and further, if it is narrowed down to a proper range as the yarn pitch of the fabric, the yarn pitch Pc can be determined.

[0017] On the other hand, the yarn pitch Pc is obvious from the fabric itself, and the user may input the yarn pitch Pc of the fabric as data. Thus, either the method calculated based on the image data or the method by manual input may be used.

[0018] In step S120, the CPU acquires a test pattern Tx that is optimal for the recording medium. The conditions for the test pattern Tx that is optimal for the recording medium are As the first condition, "not including a group of ruled lines with a ruled line pitch Pk that is an integer multiple of the yarn pitch Pc of the fabric".

[0019] Furthermore, if the target is expanded, As the second condition, "the least common multiple of the yarn pitch Pc of the fabric and the ruled line pitch Pk is a value larger than a predetermined threshold".

[0020] Under the above conditions, it is expected that multiple test patterns T will be candidates. In this case, it is also possible to select the first test pattern that does not match. Also, although the first condition is satisfied, there may be multiple test patterns T in which the multiple occurs below a predetermined threshold for the second condition. At this time, the grid line pitch Pk may be selected such that the test pattern has the interval with the least frequency of overlap between the grid lines and the weave. For example, when the yarn pitch Pc is 6, the grid line pitch Pk of the first test pattern T1 is 3, and the grid line pitch Pk of the second test pattern T2 is 4, the second test pattern T2 has a lower frequency of overlap between the grid lines and the weave. Therefore, the second test pattern T2 is selected.

[0021] Thus, it can be said that the first condition is a process of controlling so that the obtained interval Pc of the yarns does not match the interval Pk of the grid lines constituting the grid line group in the test pattern T. Also, when multiple test patterns remain as candidates under the second condition, the process of "selecting the test pattern in which the grid line pitch Pk is the interval with the least frequency of overlap between the grid lines and the weave" has multiple test patterns T, and the number of matches between the obtained interval Pc of the yarns and the interval of the grid lines Pk constituting the grid line group in each test pattern T is obtained, and it can be said that the process is to select the test pattern with fewer matches.

[0022] It can be said that in any condition, the control unit 20 obtains the interval Pc of the yarns in the fabric and changes the interval of the grid lines Pk constituting the grid line group in the test pattern T based on the obtained interval Pc of the yarns. The CPU obtains the selected test pattern Tx from the storage 23, and in step S130, performs printing on the fabric, which is a recording medium, using the same test pattern Tx. After printing the test pattern Tx, in step S140, an image of the fabric at the printed part is obtained, and in step S150, the image is subjected to a fast Fourier transform (FFT) operation.

[0023] FIG. 7 shows an image of the fabric when the process of changing the test pattern is not performed, and FIG. 8 shows the calculation result when fast Fourier transform calculation is performed based on the image data of this image. Specifically, pixel data between the broken lines shown in FIG. 7 is acquired as plot data and fast Fourier transform (FFT) calculation is performed. In this case, it was "including a group of ruled lines that is the ruled line pitch Pk which is an integer multiple of the yarn pitch Pc of the fabric". Therefore, frequency components based on the yarn pitch of the fabric cannot be removed without affecting the ruled line pitch Pk. Therefore, component values appear in many frequency components, making it difficult to perform calculations for landing position deviation.

[0024] FIG. 9 shows an image of the fabric when the process of changing the test pattern is performed, and FIG. 10 shows the calculation result when fast Fourier transform calculation is performed based on the image data of this image. Through the processes of steps S110 and S120, the test pattern Tx selected according to the first condition and the second condition is used. Therefore, it is possible to remove the component values of unnecessary frequency components based on the yarn pitch Pc of the fabric. Alternatively, by performing image processing through a band-pass filter that removes unnecessary frequency components based on the yarn pitch Pc of the fabric, the component values of the frequency components based on the yarn pitch Pc of the fabric do not appear in the calculation result after the fast Fourier transform calculation.

[0025] Therefore, in step S160, based on the calculation result after the fast Fourier transform calculation, the CPU acquires the landing position deviation, and in step S170, calculates a correction value to eliminate the acquired landing position deviation. Note that the specific calculations in steps S160 and S170 are appropriately obtained by known calculation methods according to the nozzle arrangement of the print head 11 and the nozzle position for printing the test pattern.

[0026] In the above-described embodiment, a plurality of test patterns T with different ruled line pitches Pk are prepared in the storage 23. However, it is also possible to generate a test pattern T with a predetermined grid line pitch Pk. In this case, in step S120, in the process of obtaining the test pattern Tx based on the first condition and the second condition, a new test pattern T is generated so that the grid line pitch Pk clears the first condition and the second condition. Then, in step S130, printing is performed on the fabric using the newly generated test pattern T.

[0027] Also in this case, since the test pattern T that clears the first condition and the second condition is generated, it is possible to remove the component values of unnecessary frequency components based on the yarn pitch Pc of the fabric. Alternatively, by performing image processing through a band-pass filter that removes unnecessary frequency components based on the yarn pitch Pc of the fabric, the component values of the frequency components based on the yarn pitch Pc of the fabric do not appear in the calculation result after the fast Fourier transform calculation.

[0028] In this way, the control unit 20 can generate a grid line group of the test pattern based on a predetermined parameter, and generates the test pattern T so that the interval between the grid lines constituting the grid line group in the test pattern does not match the obtained interval Pc of the yarns, using the interval Pc of the obtained yarns as a parameter. The present invention can be grasped not only as an invention of a shaped article but also as an invention of a method considering its processing steps, and the steps are also clear from the flowchart shown in FIG. 6.

[0029] Needless to say, the present invention is not limited to the above embodiments. As is obvious to those skilled in the art, · Appropriately change the combination of mutually replaceable members, configurations, etc. disclosed in the above embodiments and apply them · Although not disclosed in the above embodiments, appropriately replace members and configurations, etc. that are known technologies and mutually replaceable with the members and configurations, etc. disclosed in the above embodiments, and also change their combinations and apply them ·Although not disclosed in the above embodiments, members and configurations that can be appropriately substituted as substitutes for the members and configurations disclosed in the above embodiments by those skilled in the art based on known technologies, etc., and the combinations thereof can be changed and applied. is disclosed as one embodiment of the present invention.

Explanation of Signs

[0030] 10… Printer (recording device), 11… Print head, 12… Platen motor, 13… Platen, 14… Main scanning motor, 20… Control unit, 21… Motor drive unit, 22… Head drive unit, 23… Storage.

Claims

1. A recording unit capable of recording a test pattern having a grid line group at a predetermined interval on a fabric, and a control unit that controls the recording in the recording unit, characterized in that the control unit acquires the interval between the warp threads in the fabric, and changes the interval between the grid lines constituting the grid line group in the test pattern based on the acquired interval between the warp threads. A recording device

2. The recording device according to claim 1, characterized in that the control unit controls so that the acquired interval between the warp threads does not match the interval between the grid lines constituting the grid line group in the test pattern

3. The control unit forms a plurality of the test patterns, obtains the number of matches between the acquired interval between the warp threads and the interval between the grid lines constituting the grid line group in each test pattern, and selects a test pattern having the smallest number of matches from among the respective test patterns. The recording device according to claim 1

4. The control unit is capable of generating the grid line group of the test pattern based on a predetermined parameter, and generates the test pattern so that the interval between the grid lines constituting the grid line group in the test pattern does not match the acquired interval between the warp threads, using the acquired interval between the warp threads as the parameter. The recording device according to claim 1

5. The recording unit drives a print head in a main scanning direction, drives a recording medium in a sub-scanning direction, and performs recording by attaching dot-like color ink, the grid lines are formed by aligning the dot-like color ink in a predetermined direction, and the grid line group includes grid lines in a direction parallel to the arrangement direction of the warp threads. The recording device according to any one of claims 1 to 4

6. A recording method for a recording device including a recording unit capable of recording a test pattern having a grid line group at a predetermined interval on a fabric, and a control unit that controls the recording in the recording unit, the method comprising a step of acquiring the interval between the warp threads in the fabric, and a step of changing the interval between the grid lines constituting the grid line group in the test pattern based on the acquired interval between the warp threads. A recording method for a recording device

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