EP4155445A1

EP4155445A1 - Liquid discharge apparatus and embroidery system

Info

Publication number: EP4155445A1
Application number: EP22197334.0A
Authority: EP
Inventors: Taito Omura
Original assignee: Ricoh Co Ltd
Current assignee: Ricoh Co Ltd
Priority date: 2021-09-27
Filing date: 2022-09-23
Publication date: 2023-03-29
Anticipated expiration: 2042-09-23
Also published as: EP4155445B1; JP2023047540A

Abstract

A liquid discharge apparatus (2) includes a head (21) and an adjuster (22). The head (21) discharges liquid onto a linear medium based on image data. The adjuster (22) is disposed downstream from the head (21) in a feed direction of the linear medium and adjusts a feed speed of the linear medium. The adjuster (22) increases a feed distance of the linear medium in a case where the feed speed is lower than a predetermined value.

Description

BACKGROUND

Technical Field

Embodiments of the present invention relate to a liquid discharge apparatus and an embroidery system.

Related Art

In the related art, a liquid discharge apparatus is known that discharges liquid onto a linear medium such as a thread.
As a liquid discharge apparatus, there is known a technique of maintaining tension of a thread constant by a tension sensor (for example, see Japanese Unexamined Patent Application Publication No. H07-000661 ).
There is a demand for stabilizing image quality in liquid discharge apparatuses.

SUMMARY

An object of the present invention is to stabilize image quality.
According to one aspect of the present invention, a liquid discharge apparatus includes a head and an adjuster. The head discharges liquid onto a linear medium based on image data. The adjuster is disposed downstream from the head in a feed direction of the linear medium and adjusts a feed speed of the linear medium. The adjuster increases a feed distance of the linear medium in a case where the feed speed is lower than a predetermined value.
According to another aspect of the present invention, there is provided an embroidery system includes the liquid discharge apparatus and an embroidery apparatus. The embroidery apparatus performs embroidery using the linear medium to which the liquid is applied by the liquid discharge apparatus.
According to the present invention, image quality can be stabilized in a liquid discharge apparatus and an embroidery system.

BRIEF DESCRIPTION OF SEVERAL VIEWS OF THE DRAWINGS

A more complete appreciation of the disclosure and many of the attendant advantages and features thereof can be readily obtained and understood from the following detailed description with reference to the accompanying drawings, wherein:

FIG. 1 is a diagram illustrating an overall configuration of an embroidery system according to an embodiment of the present disclosure;
FIG. 2 is a diagram illustrating a functional configuration of a controller in the embroidery system of FIG. 1;
FIG. 3 is a diagram illustrating an operation of an adjuster in the embroidery system of FIG. 1;
FIG. 4 is a flowchart of a feed-speed adjusting operation of the embroidery system of FIG. 1; and
FIG. 5 is a diagram illustrating a result of adjustment of a feed speed by the embroidery system of FIG. 1.

The accompanying drawings are intended to depict embodiments of the present disclosure and should not be interpreted to limit the scope thereof. The accompanying drawings are not to be considered as drawn to scale unless explicitly noted.

DESCRIPTIONS OF EMBODIMENTS

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the present disclosure. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise.
In describing embodiments illustrated in the drawings, specific terminology is employed for the sake of clarity. However, the disclosure of this specification is not intended to be limited to the specific terminology so selected and it is to be understood that each specific element includes all technical equivalents that have a similar function, operate in a similar manner, and achieve a similar result.
Embodiments of the present invention are described below in detail with reference to the drawings. In the drawings, the same components are denoted by the same reference numerals, and redundant description will be appropriately omitted.
A description is given below of an embroidery system, including a liquid discharge apparatus and an embroidery apparatus, according to an embodiment of the present disclosure.
Below, a description is given of an embodiment of the present disclosure.

FIG. 1 is a diagram illustrating an overall configuration of an embroidery system 1. The embroidery system 1 includes a liquid discharge apparatus 2 and an embroidery apparatus 3. The liquid discharge apparatus 2 is connected to the embroidery apparatus 3 in a wired or wireless manner to communicate with the embroidery apparatus 3. The liquid discharge apparatus 2 discharges liquid to a thread M to dye the thread M. The embroidery apparatus 3 performs embroidery using the thread M dyed by the liquid discharge apparatus 2.
The thread M is an example of a linear medium. The thread M is glass fiber thread, wool thread, cotton thread, synthetic thread, metal thread, mixed thread of wool, cotton, polymer, or metal, yarn, filament, or a linear member (continuous base material) to which liquid can be applied. Examples of the thread M include a braid and a flat cord.
The liquid discharge apparatus 2 includes a head 21 and an adjuster 22. The liquid discharge apparatus 2 discharges liquid from the head 21 to the thread M supplied from a spool 11 and fed along a feed direction 10, to apply the liquid to the thread M to dye the thread M.
The embroidery apparatus 3 has a needle 31 connected to the thread M. The embroidery apparatus 3 performs embroidery on a cloth C with the needle 31 using the dyed thread M supplied from the liquid discharge apparatus 2 through a through-hole 33 of a housing 32, to form an embroidery pattern on the cloth C. The thread M is pulled out from the spool 11 and fed along the feed direction 10 in response to embroidering of the thread M on the cloth C by the embroidery apparatus 3.
The head 21 discharges the liquid onto the fed thread M based on image data that is a source of an image to be formed on the thread M with the liquid.
The adjuster 22 includes a first nip roller pair 221, a second nip roller pair 222, a dancer roller 223, and a support roller 224. The adjuster 22 is disposed downstream from the head 21 in the feed direction 10.
Each of the first nip roller pair 221 and the second nip roller pair 222 includes a pair of rotatable rollers to nip the thread M between the pair of rollers to feed the thread M. The dancer roller 223 is disposed between the first nip roller pair 221 and the second nip roller pair 222, and is movable along a movement direction 20 indicated by an arrow while rotating. The support roller 224 is disposed downstream from the second nip roller pair 222 in the feed direction 10 and supports the thread M.
The adjuster 22 moves the dancer roller 223 along the movement direction 20 to change the feed distance of the thread M fed in the adjuster 22, thus allowing adjustment of the feed speed V of the thread M.
The liquid discharge apparatus 2 includes a controller 23, a rotary encoder 24, a guide roller pair 25, a first sensor 26, and a second sensor 27.
The controller 23 controls the operations of the head 21 and the adjuster 22. The rotary encoder 24 is disposed upstream from the head 21 in the feed direction 10, and outputs a signal obtained by detecting the feeding condition of the thread M to the controller 23.
The feeding condition of the thread M is, for example, a supply speed of the thread M supplied from the spool 11 or a condition in which the thread M is stretched by tension. The controller 23 causes the head 21 to discharge liquid in accordance with the signal from the rotary encoder 24 based on the image data.
The guide roller pair 25 is a pair of rollers between which the thread M is interposed, and guides the thread M dyed with the liquid toward the adjuster 22.
The first sensor 26 is disposed upstream from the adjuster 22 in the feed direction 10, and outputs a detection signal of the thread M to the controller 23. The second sensor 27 is an example of a detector that is disposed downstream from the adjuster 22 in the feed direction 10 and outputs a detection signal of the thread M to the controller 23.
The second sensor 27 includes, for example, a rotary encoder disposed on a rotating body in contact with the thread M. The rotary encoder outputs a detection signal of a rotation angle at which the rotating body rotates per unit time. The rotating body is, for example, a roller that can rotate while contacting the thread M to support the thread M. However, the configuration of the second sensor 27 is not limited to such a configuration. The second sensor 27 may also include, for example, a camera that outputs a detection signal of an image formed on the thread M by the liquid discharged from the head 21.
The controller 23 acquires data on the feed speed V of the thread M downstream from the adjuster 22 in the feed direction 10 by calculation, based on the detection signal from the second sensor 27, and outputs the data to the adjuster 22. The adjuster 22 can acquire the information on the feed speed V of the thread M from the controller 23.

FIG. 2 is a block diagram illustrating a functional configuration of the controller 23 according to an embodiment of the present disclosure. The controller 23 includes an input-and-output unit 231, a determination unit 232, a feed-speed acquisition unit 233, an adjustment control unit 234, a discharge control unit 235, and a stop control unit 236.
The controller 23 may implement the above-described functions with an electric circuit and may also implement some or all of the above-described functions with software executed by a central processing unit (CPU). The controller 23 may implement the above-described functions with a plurality of circuits or a plurality of pieces of software.
The input-and-output unit 231 controls input and output of signals or data to and from the controller 23.
The determination unit 232 determines a lower limit value Lt of the feed speed V of the thread M based on image data Im input from an external device such as a personal computer (PC) via the input-and-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 feed speed V of the thread M into the discharge frequency.
As a result of intensive studies by the inventor, it has been found that liquid discharge becomes unstable in the vicinity of 10 hertz (Hz). For this reason, it is preferable that the lower limit value Lt is set to 10 Hz or 10 Hz or more.
The feed-speed acquisition unit 233 acquires data on the feed speed V of the thread M by calculation based on the detection signals from the first sensor 26 and the second sensor 27.
The adjustment control unit 234 adjusts the feed speed V with the adjuster 22 based on the data on the feed speed V of the thread M acquired by the feed-speed acquisition unit 233.
Particularly in the present embodiment, when the feed speed V of the thread M is lower than the lower limit value Lt, the adjustment control unit 234 increases the feed distance of the thread M with the adjuster 22 to adjust the feed speed V of the thread M.
For example, when the feed speed Vd of the thread M downstream from the adjuster 22 in the feed direction 10 falls below the lower limit value Lt, the adjustment control unit 234 increases the feed distance of the thread M with the adjuster 22 to adjust the feed speed Vu of the thread M upstream from the adjuster 22 in the feed direction 10 so as not to be lower than the lower limit value Lt. For example, when the value obtained by converting the feed speed V of the thread M into the discharge frequency is lower than 10 Hz, the adjustment control unit 234 causes the adjuster 22 to move the dancer roller 223 along the movement direction 20 to increase the feed distance or length of the thread M.
The discharge control unit 235 causes the head 21 to discharge the liquid according to the signal from the rotary encoder 24 based on the image data Im.
When the feed speed V of the thread M cannot be adjusted with the adjuster 22, the stop control unit 236 causes the head 21 to stop discharging the liquid. For example, the stop control unit 236 can determine whether the feed speed V of the thread M can be adjusted with the adjuster 22 based on the detection signal of at least one of the first sensor 26 and the second sensor 27.

FIG. 3 is a diagram illustrating an operation of the adjuster 22 in the embroidery system 1. When the feed speed V of the thread M is lower than the lower limit value Lt under the control of the controller 23, the adjuster 22 moves the dancer roller 223 in the direction indicated by the arrow of the movement direction 20 to increase the feed distance of the thread M, thus adjusting the feed speed V of the thread M.
For example, when the feed speed Vd of the thread M downstream from the adjuster 22 in the feed direction 10 is lower than the lower limit value Lt, the adjuster 22 increases the feed distance of the thread M to adjust the feed speed Vu of the thread M upstream from the adjuster 22 in the feed direction 10 so as not to be lower than the lower limit value Lt. When the value obtained by converting the feed speed V of the thread M into the discharge frequency by the determination unit 232 is lower than 10 Hz, the adjuster 22 increases the feed distance of the thread M.
When the dancer roller 223 has completely moved in the movable range along the movement direction 20, the head 21 may stop discharging the liquid under the control of the controller 23. When the head 21 stops the discharge, the adjuster 22 moves the dancer roller 223 in a direction opposite to the direction indicated by the arrow of the movement direction 20, to reduce the feed distance of the thread M. As a result, after the dancer roller 223 becomes movable along the movement direction 20, the head 21 resumes discharging the liquid.
FIG. 4 is a flowchart of an operation of adjusting the feed speed in the embroidery system 1. After an embroidery design is determined by the user of the embroidery system 1, the image data Im corresponding to the embroidery design is input to the embroidery system 1 and the embroidery system 1 starts the operation of FIG. 4.
First, in step S41, the embroidery system 1 determines, with the determination unit 232, the lower limit value Lt of the feed speed V of the thread M based on the image data Im. The determination unit 232 determines the liquid application amount (gradation) per unit length of the thread M based on the image data Im to determine the feed speed V of the thread M, and then converts the feed speed V into the discharge frequency, thus allowing the lower limit value Lt to be determined.
Subsequently, in step S42, the embroidery system 1 calculates, with the feed-speed acquisition unit 233, data on the feed speed V of the thread M based on the detection signals from the first sensor 26 and the second sensor 27 to acquire the data on the feed speed V of the thread M.
Subsequently, in step S43, the embroidery system1 causes the adjustment control unit 234 to determine whether the feed speed V is lower than the lower limit value Lt.
In step S43, when the adjustment control unit 234 determines that the difference is not less than the predetermined value (No in step S43), the embroidery system 1 ends the operation.
On the other hand, when the adjustment control unit 234 determines in step S43 that the feed speed V of the thread M is lower than the predetermined value (Yes in step S43), the embroidery system 1 increases, with the adjuster 22, the feed distance of the thread M based on the data on the feed speed V of the thread M to adjust the feed speed V.
In this manner, the embroidery system 1 can adjust the feed speed V of the thread M.

FIG. 5 is a diagram illustrating an adjustment result of the feed speed V by the embroidery system 1. In FIG. 5, the horizontal axis represents time t, and the vertical axis represents the feed speed V. In FIG. 5, the solid-line graph represents the feed speed Vd of the thread M downstream from the adjuster 22 in the feed direction 10. The dot-dash line graph represents the feed speed Vu of the thread M upstream from the adjuster 22 in the feed direction 10.
As illustrated in FIG. 5, when the feed speed Vd changes, the embroidery system 1 adjusts the feed speed V of the thread M with the adjuster 22 in accordance with the lower limit value Lt determined by the determination unit 232 such that the feed speed Vu of the thread M upstream from the adjuster 22 in the feed direction 10 does not fall below the lower limit value Lt.
A hatched region 51 in FIG. 5 corresponds to a difference between the feed speeds V of the thread M upstream and downstream from the adjuster 22 in the feed direction 10, and represents an adjustment amount of the feed speed V with the adjuster 22.

Advantageous Effects of Liquid Discharge Apparatus 2

Effects of the liquid discharge apparatus 2 in the embroidery system 1 are described below.
In the related art, in an embroidery system including a liquid discharge apparatus and an embroidery apparatus, a user pulls a thread with a hand immediately before starting embroidery to perform an operation of aligning a head of an embroidery pattern formed on a cloth with a tip of a needle to which the thread is connected. At this time, the feed speed of the thread may suddenly change.
Further, when the sewing manner is largely changed in relation to an embroidery design or when the sewing position is jumped, the feed speed of the thread may be rapidly changed.
A liquid discharge apparatus in an embroidery system discharges liquid while changing the discharge frequency in accordance with the feed speed of the thread, to dye the thread. Accordingly, when the discharge frequency is rapidly changed in accordance with the feed speed of the thread, the discharge may become unstable, or the image quality may be deteriorated at a color change or a position of superimposition due to a positional deviation of the liquid applied to the thread.
When the tension of the thread fed in the embroidery system becomes too high, a burden is put on the needle and the embroidery apparatus. The tension of the thread may be high in an embroidery system including a liquid discharge apparatus, a configuration that can maintain a predetermined tension is preferable.
The liquid discharge apparatus 2 according to the present embodiment includes the head 21 and the adjuster 22. The head 21 discharges liquid onto the fed thread M (serving as a linear medium) based on image data. The adjuster 22 is disposed downstream from the head 21 in the feed direction 10 of the thread M and adjusts the feed speed V of the thread M. The adjuster 22 increases the feed distance of the thread M when the feed speed V is lower than the lower limit value Lt (predetermined value). Such a configuration allows the liquid discharge apparatus 2 to reduce a rapid change in the feed speed of the thread M, reduce a rapid change in the discharge frequency corresponding to the feed speed of the thread M, and stabilize the discharge of the liquid with the head 21. Thus, the image quality can be stabilized. The liquid discharge apparatus 2 can adjust the feed speed of the thread M to maintain the tension of the fed thread M at a predetermined tension, thus allowing reduction the burden on the needle or the embroidery apparatus itself.
In the present embodiment, when the feed speed Vd downstream from the adjuster 22 in the feed direction 10 is lower than the lower limit value Lt, the adjuster 22 increases the feed distance of the thread M to adjust the feed speed Vu upstream from the adjuster 22 in the feed direction 10 so as not to be lower than the lower limit value Lt. Such a configuration allows the liquid discharge apparatus 2 to reduce a rapid change in the feed speed of the thread M, reduce a rapid change in the discharge frequency corresponding to the feed speed of the thread M, and stabilize the discharge of the liquid with the head 21. Thus, the image quality can be stabilized.
As a result of intensive studies by the inventor, it has been found that the discharge by the head 21 becomes unstable when the value obtained by converting the feed speed V of the thread M into the discharge frequency is close to 10 Hz. For this reason, the lower limit value Lt is set to, preferably, 10 Hz or 10 Hz or more. For example, it is preferable that the adjuster 22 increases the feed distance when the value obtained by converting the feed speed V into the discharge frequency is lower than 10 Hz. Such a configuration can stabilize discharge by the head 21 and stabilize image quality of the liquid discharge apparatus 2.
In the present embodiment, the adjuster 22 moves the dancer roller 223 to increase the feed distance of the thread M. However, when the dancer roller 223 moves to the limit, the feed speed V cannot be adjusted. For this reason, in a case where the feed speed V cannot be adjusted by the adjuster 22, it is preferable that the head 21 stops the discharge of the liquid under the control of the stop control unit 236. Such a configuration can prevent degradation in image quality due to the fact that the feed speed V is not adjusted. The liquid discharge apparatus 2 returns the position of the dancer roller 223, while the discharge of the liquid by the head 21 is stopped, to allow adjustment of the feed speed V again. Thus, the liquid discharge apparatus 2 can restart the discharge of the liquid by the head 21 after the adjustment of the feed speed V becomes adjustable again.
In the present embodiment, the liquid discharge apparatus 2 includes the second sensor 27 (serving as a detector) disposed downstream from the adjuster 22 in the feed direction 10. The second sensor 27 outputs a detection signal of the thread M. The adjuster 22 acquires data on the feed speed V based on the detection signal from the second sensor 27. For example, the second sensor 27 includes a rotary encoder disposed on a rotating body in contact with the thread M. The rotary encoder outputs a detection signal of a rotation angle at which the rotating body rotates per unit time. The liquid discharge apparatus 2 adjusts the feed speed V based on the acquired data on the feed speed V, thus allowing accurate adjustment of the feed speed V.
The second sensor 27 may include a camera that outputs a detection signal of an image formed on the thread M by the liquid discharged from the head 21, instead of the rotary encoder.

Other Embodiments

Although some embodiments and variations have been described above, embodiments of the present disclosure are not limited to the above-described embodiments and variations. Various modifications and substitutions may be made to the above-described embodiments without departing from the scope described in the appended claims.
The term "liquid" includes any liquid having a viscosity or a surface tension that can be discharged from the head. The "liquid" is not limited to a particular liquid and may be any liquid having a viscosity or a surface tension to be discharged from a head. However, preferably, the viscosity of the liquid is not greater than 30 mPa·s under ordinary temperature and ordinary pressure or by heating or cooling. Examples of the liquid include a solution, a suspension, or an emulsion that contains, for example, a solvent, such as water or an organic solvent, a colorant, such as dye or pigment, a functional material, such as a polymerizable compound, a resin, or a surfactant, a biocompatible material, such as deoxyribonucleic acid (DNA), amino acid, protein, or calcium, or an edible material, such as a natural colorant.
Examples of an energy source for generating energy to discharge liquid include a piezoelectric actuator (a laminated piezoelectric element or a thin-film piezoelectric element), a thermal actuator that employs a thermoelectric conversion element, such as a thermal resistor (element), and an electrostatic actuator including a diaphragm and opposed electrodes.
The terms "image formation", "recording", "printing", "image printing", and "molding" used in the above-described embodiments of the present disclosure may be used synonymously with each other.
The numbers such as ordinal numbers and quantities used in the descriptions of the above-described embodiments are all examples for specifically describing the technology of the present invention, and embodiments of the present invention are not limited to the exemplified numbers. In addition, the above-describe connections among the components are examples for specifically describing the technology of the present invention, and connections for implementing functions of the present invention are not limited to the above-described examples.
The functions of the above-described embodiments can be implemented with one or a plurality of processing circuits. The term "processing circuit" or "circuitry" in the present specification includes a programmed processor to execute each function by software, such as a processor implemented by an electronic circuit, and devices, such as an application specific integrated circuit (ASIC), a digital signal processor (DSP), and a field programmable gate array (FPGA), and conventional circuit modules arranged to perform the recited functions.

Claims

A liquid discharge apparatus (2), comprising:
a head (21) configured to discharge liquid onto a linear medium based on image data; and

an adjuster (22) disposed downstream from the head (21) in a feed direction of the linear medium and configured to adjust a feed speed of the linear medium,

wherein the adjuster (22) increases a feed distance of the linear medium in a case where the feed speed is lower than a predetermined value.
The liquid discharge apparatus according to claim 1,
wherein in a case where the feed speed of the linear medium downstream from the adjuster in the feed direction is lower than the predetermined value, the adjuster increases the feed distance of the linear medium to adjust the feed speed of the linear medium upstream from the adjuster in the feed direction so as not to be lower than the predetermined value.
The liquid discharge apparatus according to claim 1 or 2,
wherein the adjuster increases the feed distance in a case where a value obtained by converting the feed speed into a discharge frequency is lower than 10 hertz.
The liquid discharge apparatus according to any one of claims 1 to 3,
wherein the head stops discharging the liquid in a case where the feed speed cannot be adjusted by the adjuster.
The liquid discharge apparatus according to any one of claims 1 to 4, further comprising a detector (27) disposed downstream from the adjuster in the feed direction and configured to output a detection signal of the linear medium,
wherein the adjuster acquires data on the feed speed based on the detection signal from the detector.
The liquid discharge apparatus according to claim 5,
wherein the detector (27) is disposed on a rotating body in contact with the linear medium and configured to output a detection signal of a rotation angle of the rotating body rotated per unit time.
The liquid discharge apparatus according to claim 5,
wherein the detector (27) outputs a detection signal of an image formed on the linear medium by the liquid discharged from the head.
An embroidery system (1), comprising:
the liquid discharge apparatus (2) according to any one of claims 1 to 7; and

an embroidery apparatus (3) configured to perform embroidery using the linear medium to which the liquid is applied by the liquid discharge apparatus.