Liquid ejection device and embroidery system

Abstract

To stabilize image quality.SOLUTION: A liquid discharge device includes: a head for discharging liquid on the basis of image data to a transported linear medium; and regulating means installed downstream from the head in a transportation direction of the linear medium and regulating a transportation speed of the linear medium. The regulating means increases a transportation distance of the linear medium when the transportation speed falls below a specified value.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to a liquid ejection device and an embroidery system.

Background Art

[0002] Conventionally, a liquid ejection device that ejects liquid onto a linear medium such as a thread has been known.

[0003] As a liquid ejection device, a technique for maintaining a constant tension of a thread by a tension sensor has been disclosed (see, for example, Patent Document 1).

Summary of the Invention

Problems to be Solved by the Invention

[0004] In a liquid ejection device, it is required to stabilize the image quality.

[0005] An object of the present invention is to stabilize the image quality.

Means for Solving the Problems

[0006] A liquid ejection device according to an aspect of the present invention includes a head that ejects liquid onto a conveyed linear medium based on image data, and an adjustment unit that is provided downstream of the head in the conveyance direction of the linear medium and adjusts the conveyance speed of the linear medium. When the conveyance speed is lower than a predetermined value, the adjustment unit increases the conveyance distance of the linear medium. When the head cannot adjust the conveyance speed by the adjustment means, the discharge of the liquid is stopped. to.

Effects of the Invention

[0007] According to the present invention, the image quality can be stabilized.

Brief Description of the Drawings

[0008]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Embodiments for Carrying Out the Invention

[0009] Hereinafter, embodiments for carrying out the invention will be described in detail with reference to the drawings. In each drawing, the same components are denoted by the same reference numerals, and duplicate descriptions will be omitted as appropriate.

[0010] Hereinafter, embodiments will be described taking an embroidery system including a liquid ejection device and an embroidery device as an example.

[0011] [Embodiment] [Example of the Overall Configuration of Embroidery System 1] FIG. 1 is a diagram illustrating the overall configuration of the embroidery system 1. The embroidery system 1 includes a liquid ejection device 2 and an embroidery device 3. The liquid ejection device 2 is communicably connected to the embroidery device 3 by wire or wirelessly. The liquid ejection device 2 dyes the thread M by ejecting liquid onto the thread M from the head 21. The embroidery device 3 performs embroidery using the thread M dyed by the liquid ejection device 2.

[0012] The thread M is an example of a linear medium. The thread M is a glass fiber thread, wool thread, cotton thread, synthetic thread, metal thread, a mixed thread of wool, cotton, polymer, or metal, yarn, filament, or a linear member (continuous base material) to which liquid can be applied. The thread M includes twisted cords, flat cords, etc.

[0013] The liquid ejection device 2 has a head 21 and an adjustment means 22. The liquid ejection device 2 dyes the thread M by ejecting liquid from the head 21 onto the thread M supplied from the thread reel 11 and conveyed along the conveyance direction 10.

[0014] The embroidery device 3 has a needle 31 connected to the thread M. The embroidery device 3 uses the dyed thread M supplied from the liquid ejection device 2 through a through hole 33 provided in the housing 32 to embroider the cloth C with the needle 31, and forms an embroidery pattern (embroidery design) on the cloth C. The thread M is drawn out from the thread spool 11 and conveyed along the conveyance direction 10 as the thread M is embroidered on the cloth C by the embroidery device 3.

[0015] The head 21 ejects liquid onto the conveyed thread M based on image data that is the basis of the image to be formed on the thread M by the liquid.

[0016] The adjustment means 22 includes a first nip roller 221, a second nip roller 222, a dancer roller 223, and a support roller 224. The adjustment means 22 is provided on the downstream side of the head 21 in the conveyance direction 10.

[0017] Each of the first nip roller 221 and the second nip roller 222 includes a pair of rotatable rollers, and conveys the thread M while sandwiching it between the pair of rollers. The dancer roller 223 is provided between the first nip roller 221 and the second nip roller 222, and is a roller that can move along the moving direction 20 indicated by the arrow while rotating. The support roller 224 is provided on the downstream side of the second nip roller 222 in the conveyance direction 10, and is a roller that supports the thread M.

[0018] The adjustment means 22 can adjust the conveyance speed V of the thread M by moving the dancer roller 223 along the moving direction 20 and changing the conveyance distance of the thread M conveyed in the adjustment means 22.

[0019] Further, the liquid ejection device 2 includes a control means 23, a rotary encoder 24, a guide roller 25, a first sensor 26, and a second sensor 27.

[0020] The control means 23 controls the operations of the head 21 and the adjustment means 22 respectively. The rotary encoder 24 is provided upstream of the head 21 in the conveying direction 10 and outputs a signal detecting the conveying state of the yarn M to the control means 23. The conveying state of the yarn M is, for example, the supply speed of the yarn M supplied from the yarn bobbin 11, the state in which the yarn M is stretched by tension, and the like. The control means 23 discharges liquid to the head 21 according to the signal from the rotary encoder 24 based on the image data.

[0021] The guide roller 25 is composed of a pair of rollers provided so as to interpose the yarn M, and guides the yarn M dyed with liquid toward the adjustment means 22.

[0022] The first sensor 26 is provided upstream of the adjustment means 22 in the conveying direction 10 and outputs a detection signal of the yarn M to the control means 23. The second sensor 27 is provided downstream of the adjustment means 22 in the conveying direction 10 and is an example of a detection means that outputs a detection signal of the yarn M to the control means 23.

[0023] The second sensor 27 includes, for example, a rotary encoder provided on a rotating body in contact with the yarn M, and outputs a detection signal of the rotation angle of the rotating body per unit time. The rotating body is a roller or the like that can rotate while supporting the yarn M by contacting the yarn M. However, the configuration of the second sensor 27 is not limited thereto. For example, the second sensor 27 can also include a camera or the like that outputs a detection signal of an image formed on the yarn M by the liquid discharged from the head 21.

[0024] The control means 23 obtains information on the conveying speed V of the yarn M downstream of the adjustment means 22 in the conveying direction 10 by calculation based on the detection signal from the second sensor 27 and outputs it to the adjustment means 22. The adjustment means 22 can obtain information on the conveying speed V of the yarn M from the control means 23.

[0025] <Functional configuration example of the control means 23> FIG. 2 is a block diagram showing an example of the functional configuration of the control means 23. The control means 23 includes an input / output unit 231, a determination unit 232, a conveyance speed acquisition unit 233, an adjustment control unit 234, a discharge control unit 235, and a stop control unit 236.

[0026] The control means 23 can realize these functions by an electric circuit, or can also realize some or all of these functions by software (CPU; Central Processing Unit). The control means 23 may realize these functions by a plurality of circuits or a plurality of software.

[0027] The input / output unit 231 controls the input / output of signals or data to / from the control means 23.

[0028] The determination unit 232 determines a lower limit value Lt of the conveyance speed V of the yarn M based on the image data Im input from an external device such as a PC (Personal Computer) via the input / output unit 231. The lower limit value Lt is an example of a predetermined value. For example, the determination unit 232 determines the lower limit value Lt based on a value obtained by converting the conveyance speed V of the yarn M into a discharge frequency.

[0029] As a result of the inventors' intensive studies, it has been found that the discharge becomes unstable around 10 Hz. Therefore, the lower limit value Lt is preferably set to 10 Hz or higher.

[0030] The conveyance speed acquisition unit 233 acquires information on the conveyance speed V of the yarn M by calculation based on the detection signals from the first sensor 26 and the second sensor 27 respectively.

[0031] The adjustment control unit 234 adjusts the conveyance speed V by the adjustment means 22 based on the information on the conveyance speed V of the yarn M acquired by the conveyance speed acquisition unit 233.

[0032] In particular, in this embodiment, when the conveyance speed V of the yarn M is lower than the lower limit value Lt, the adjustment control unit 234 adjusts the conveyance speed V of the yarn M by increasing the conveyance distance of the yarn M by the adjustment means 22.

[0033] For example, when the conveyance speed Vd of the yarn M on the downstream side of the adjusting means 22 in the conveyance direction 10 is lower than the lower limit value Lt, the adjusting means 22 increases the conveyance distance of the yarn M, so that the conveyance speed Vu of the yarn M on the upstream side of the adjusting means 22 in the conveyance direction 10 does not fall below the lower limit value Lt. For example, when the value obtained by converting the conveyance speed V of the yarn M into the discharge frequency is lower than 10 Hz, the adjustment control unit 234 increases the conveyance distance of the yarn M by moving the dancer roller 223 along the moving direction 20 by the adjusting means 22.

[0034] Based on the image data Im, the discharge control unit 235 discharges the liquid to the head 21 according to the signal from the rotary encoder 24.

[0035] When the adjustment means 22 cannot adjust the conveyance speed V of the yarn M, the stop control unit 236 stops the discharge of the liquid to the head 21. For example, based on the detection signal of at least one of the first sensor 26 or the second sensor 27, the stop control unit 236 can determine whether the adjustment means 22 can adjust the conveyance speed V of the yarn M.

[0036] <Operation example of the embroidery system 1> FIG. 3 is a diagram illustrating the operation of the adjusting means 22 in the embroidery system 1. Under the control of the control means 23, when the conveyance speed V of the yarn M is lower than the lower limit value Lt, the adjusting means 22 moves the dancer roller 223 in the direction indicated by the arrow in the moving direction 20 and increases the conveyance distance of the yarn M to adjust the conveyance speed V of the yarn M.

[0037] For example, when the conveyance speed Vd of the yarn M on the downstream side of the adjusting means 22 in the conveyance direction 10 is lower than the lower limit value Lt, the adjusting means 22 increases the conveyance distance of the yarn M so that the conveyance speed Vu of the yarn M on the upstream side of the adjusting means 22 in the conveyance direction 10 does not fall below the lower limit value Lt. When the value obtained by converting the conveyance speed V of the yarn M into the discharge frequency by the determination unit 232 is lower than 10 Hz, the adjusting means 22 increases the conveyance distance of the yarn M.

[0038] Here, when the dancer roller 223 has completely moved within the movable range along the moving direction 20, the head 21 may stop discharging the liquid under the control of the control means 23. When the head 21 stops discharging, the adjusting means 22 moves the dancer roller 223 in the direction opposite to the direction in which the arrow of the moving direction 20 points, reducing the conveying distance of the yarn M. Thereby, after the dancer roller 223 becomes movable along the moving direction 20, the head 21 resumes discharging the liquid.

[0039] FIG. 4 is a flowchart illustrating the adjustment operation of the conveying speed in the embroidery system 1. After the embroidery design is determined by the user of the embroidery system 1, the embroidery system 1 starts the operation of FIG. 4 by inputting the image data Im corresponding to the embroidery design.

[0040] First, in step S41, the embroidery system 1 determines the lower limit value Lt of the conveying speed V of the yarn M by the determination unit 232 based on the image data Im. The determination unit 232 determines the conveying speed V of the yarn M by determining the liquid application amount (tone) per unit length of the yarn M based on the image data Im, and then can determine the lower limit value Lt by converting the conveying speed V into the discharge frequency.

[0041] Subsequently, in step S42, the embroidery system 1 obtains information on the conveying speed V of the yarn M by calculation based on the detection signals from the first sensor 26 and the second sensor 27 by the conveying speed acquisition unit 233.

[0042] Subsequently, in step S43, the embroidery system 1 determines whether the conveying speed V is lower than the lower limit value Lt by the adjustment control unit 234.

[0043] If it is determined in step S43 that it does not fall below (step S43, No), the embroidery system 1 ends the operation.

[0044] On the other hand, in step S43, when it is determined that it is below (step S43, Yes), the embroidery system 1 adjusts the conveying speed V of the thread M by increasing the conveying distance of the thread M based on the information of the conveying speed V of the thread M by the adjusting means 22.

[0045] In this way, the embroidery system 1 can adjust the conveying speed V of the thread M.

[0046] <Example of adjustment result of conveying speed V> FIG. 5 is a diagram illustrating the adjustment result of the conveying speed V by the embroidery system 1. The horizontal axis of FIG. 5 indicates time t, and the vertical axis indicates the conveying speed V. In FIG. 5, the solid line graph indicates the conveying speed Vd of the thread M on the downstream side of the adjusting means 22 in the conveying direction 10. The dashed-dotted line graph indicates the conveying speed Vu of the thread M on the upstream side of the adjusting means 22 in the conveying direction 10.

[0047] As shown in FIG. 5, when the conveying speed Vd changes, the embroidery system 1 adjusts the conveying speed V of the thread M by the adjusting means 22 so that the conveying speed Vu of the thread M on the upstream side of the adjusting means 22 in the conveying direction 10 does not fall below the lower limit value Lt determined by the determination unit 232.

[0048] The region 51 indicated by the diagonal hatching in FIG. 5 corresponds to the difference in the conveying speed V on the upstream side and the downstream side of the adjusting means 22 in the conveying direction 10, and represents the adjustment amount of the conveying speed V by the adjusting means 22.

[0049] <Function and effect of the liquid ejection device 2> The function and effect of the liquid ejection device 2 in the embroidery system 1 will be described.

[0050] Conventionally, in an embroidery system having a liquid ejection device and an embroidery device, before starting embroidery, the user manually pulls the thread, so that an operation is required to align the head of the embroidery pattern formed on the cloth with the tip of the needle to which the thread is connected. At this time, the conveying speed of the thread may change suddenly.

[0051] Also, even when the sewing method changes significantly due to the embroidery design or when the sewing position jumps, the conveying speed of the thread changes rapidly.

[0052] In the embroidery system, the liquid ejection device ejects liquid while changing the ejection frequency in accordance with the conveying speed of the thread to dye the thread M. Therefore, if the ejection frequency changes rapidly in accordance with the conveying speed of the thread, the ejection may become unstable, or the image quality may deteriorate at the color change or the overlapping position due to the displacement of the position of the liquid applied to the thread.

[0053] Also, in the embroidery system, if the tension of the thread being conveyed becomes too high, it places a burden on the needle and the embroidery device itself. In an embroidery system having a liquid ejection device, since the tension of the thread may increase, a configuration that can maintain a predetermined tension is required.

[0054] The liquid ejection device 2 according to the present embodiment includes a head 21 that ejects liquid onto a conveyed thread M (linear medium) based on image data, and an adjustment means 22 provided on the downstream side of the head 21 in the conveying direction 10 of the thread M to adjust the conveying speed V of the thread M. When the conveying speed V is lower than the lower limit value Lt (predetermined value), the adjustment means 22 increases the conveying distance of the thread M. With this configuration, the liquid ejection device 2 can suppress a rapid change in the conveying speed of the thread M and can suppress a rapid change in the ejection frequency in accordance with the conveying speed of the thread M, and as a result, the ejection of the liquid by the head 21 becomes stable, and the image quality can be stabilized. Further, the liquid ejection device 2 can maintain the tension of the conveyed thread M at a predetermined tension by adjusting the conveying speed of the thread M, so that the burden on the needle and the embroidery device itself can be reduced.

[0055] Also, in the present embodiment, when the conveyance speed Vd on the downstream side of the adjustment means 22 in the conveyance direction 10 is lower than the lower limit value Lt, the adjustment means 22 increases the conveyance distance of the yarn M, so that the conveyance speed Vu on the upstream side of the adjustment means 22 in the conveyance direction 10 does not fall below the lower limit value Lt. Thereby, the liquid discharge device 2 can suppress a sudden change in the conveyance speed of the yarn M and can suppress a sudden change in the discharge frequency adjusted to the conveyance speed of the yarn M, and as a result, the discharge of the liquid by the head 21 is stabilized, and the image quality can be stabilized.

[0056] Further, as a result of the inventor's intensive study, it has been found that when the value obtained by converting the conveyance speed V of the yarn M into the discharge frequency is around 10 Hz, the discharge by the head 21 becomes unstable. Therefore, it is preferable that the lower limit value Lt is set to 10 Hz or more. For example, when the value obtained by converting the conveyance speed V into the discharge frequency is less than 10 Hz, the adjustment means 22 preferably increases the conveyance distance. Thereby, the discharge by the head 21 can be stabilized, and the image quality by the liquid discharge device 2 can be stabilized.

[0057] Also, in the present embodiment, the adjustment means 22 increases the conveyance distance of the yarn M by moving the dancer roller 223. However, when the dancer roller 223 moves to the limit, the conveyance speed V cannot be adjusted. Therefore, when the conveyance speed V cannot be adjusted by the adjustment means 22, it is preferable that the head 21 stops the discharge of the liquid under the control of the stop control unit 236. Thereby, it is possible to prevent a deterioration in image quality due to the inability to adjust the conveyance speed V. While the liquid discharge device 2 stops the discharge of the liquid by the head 21, it can return the position of the dancer roller 223 to make the conveyance speed V adjustable again, and after becoming adjustable, the liquid discharge by the head 21 can be restarted.

[0058] In this embodiment, the liquid ejection device 2 is provided on the downstream side of the adjusting means 22 in the conveying direction 10 and has a second sensor 27 (detection means) that outputs a detection signal of the yarn M. The adjusting means 22 acquires information on the conveying speed V based on the detection signal from the second sensor 27. For example, the second sensor 27 includes a rotary encoder provided on a rotating body in contact with the yarn M and outputs a detection signal of the rotation angle by which the rotating body rotates per unit time. The liquid ejection device 2 can accurately adjust the conveying speed V by adjusting the conveying speed V based on the acquired information on the conveying speed V.

[0059] Instead of the rotary encoder, the second sensor 27 may include a camera that outputs a detection signal of an image formed on the yarn M by the liquid ejected from the head 21.

[0060] [Other Preferred Embodiments] Although the preferred embodiments have been described in detail above, the present invention is not limited to the above-described embodiments, and various modifications and substitutions can be made to the above-described embodiments without departing from the scope described in the claims.

[0061] The "liquid" may be any substance having a viscosity and surface tension that can be ejected from the head and is not particularly limited, but preferably has a viscosity of 30 mPa·s or less at normal temperature and pressure or by heating or cooling. More specifically, it includes solutions, suspensions, emulsions, etc. containing solvents such as water and organic solvents, colorants such as dyes and pigments, polymerizable compounds, resins, functional imparting materials such as surfactants, biocompatible materials such as DNA, amino acids, proteins, and calcium, and edible materials such as natural pigments.

[0062] As an energy generation source for ejecting the liquid, those using a piezoelectric actuator (laminated piezoelectric element and thin film piezoelectric element), a thermal actuator using an electrothermal conversion element such as a heating resistor, an electrostatic actuator composed of a diaphragm and a counter electrode, etc. are included.

[0063] Also, in the terms of the embodiments, imaging, recording, printing, copying, and shaping are all regarded as synonyms.

[0064] The numbers such as ordinal numbers and quantities used in the description of the embodiments are all exemplified for specifically describing the technology of the present invention, and the present invention is not limited to the exemplified numbers. Also, the connection relationships between components are exemplified for specifically describing the technology of the present invention, and the connection relationships for realizing the functions of the present invention are not limited thereto.

[0065] Each function of the embodiments can be realized by one or more processing circuits. Here, the "processing circuit" in this specification refers to a processor programmed to execute each function by software like a processor implemented by an electronic circuit, an ASIC (Application Specific Integrated Circuit) designed to execute each function described above, a DSP (digital signal processor), an FPGA (field programmable gate array), and devices such as conventional circuit modules.

Description of Reference Numerals

[0066] 1 Embroidery system 11 Bobbin 2 Liquid ejection device 21 Head 22 Adjusting means 221 First nip roller 222 Second nip roller 223 Dancer roller 224 Support roller 23 Control means 231 Input / output unit 232 Determination unit 233 Conveying speed acquisition unit 234 Adjustment control unit 235 Ejection control unit 236 Stop control unit 24 Rotary encoder 25 Guide roller 26 First sensor 27 Second sensor (an example of detection means) 3 Embroidery device 10 Conveying direction 20 Moving direction 31 Needle 32 Housing 33 Through-hole C Cloth Im Image data Lt Lower limit value (an example of a predetermined value) M Thread (an example of a linear medium) V, Vd, Vu Conveying speed

Prior art documents

Patent documents

[0067]

Patent Document 1

Claims

1. A liquid ejection device having a head that ejects a liquid onto a linear medium to be conveyed based on image data, and adjusting means provided downstream of the head in the conveyance direction of the linear medium for adjusting the conveyance speed of the linear medium, wherein when the conveyance speed is less than a predetermined value, the adjusting means increases the conveyance distance of the linear medium, and when the conveyance speed cannot be adjusted by the adjusting means, the head stops ejecting the liquid.

2. A liquid ejection device having a head that ejects a liquid onto a linear medium to be conveyed based on image data, adjusting means provided downstream of the head in the conveyance direction of the linear medium for adjusting the conveyance speed of the linear medium, and detection means provided downstream of the adjusting means in the conveyance direction for outputting a detection signal of the linear medium, wherein the adjusting means obtains information on the conveyance speed based on the detection signal from the detection means, and when the conveyance speed is less than a predetermined value, increases the conveyance distance of the linear medium.

3. The liquid ejection device according to claim 1 or 2, wherein when the conveyance speed downstream of the adjusting means in the conveyance direction is less than the predetermined value, the adjusting means increases the conveyance distance of the linear medium so that the conveyance speed upstream of the adjusting means in the conveyance direction is not less than the predetermined value.

4. The liquid ejection device according to claim 1 or 2, wherein the adjusting means increases the conveyance distance when the value obtained by converting the conveyance speed into a discharge frequency is less than 10 Hz.

5. The liquid ejection device according to claim 2, wherein the detection means is provided on a rotating body in contact with the linear medium and outputs a detection signal of the rotation angle by which the rotating body rotates per unit time.

6. The liquid ejection device according to claim 2, wherein the detection means outputs a detection signal of an image formed on the linear medium by the liquid ejected from the head.

7. The liquid ejection device according to claim 5 or 6, wherein when the conveyance speed downstream of the adjusting means in the conveyance direction is less than the predetermined value, the adjusting means increases the conveyance distance of the linear medium so that the conveyance speed upstream of the adjusting means in the conveyance direction is not less than the predetermined value.

8. The adjustment means increases the conveyance distance when the value obtained by converting the conveyance speed into a discharge frequency is less than 10 Hz, in the liquid discharge device according to Claim 5 or 6.

9. A liquid discharge device according to any one of Claims 1 to 8, and an embroidery device that performs embroidery using the linear medium to which the liquid has been applied by the liquid discharge device. An embroidery system having the same.

Images