JPH11192691A - Ink jet printer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To execute detecting of a joint part by corresponding to cloths having various widths without replacing a detection sensor in terms of the detection of the joint part of the cloth in an ink jet textile printer. SOLUTION: A pair of joint part detection sensors 21, 22 are provided on the upstream side of a conveying passage for a cloth 1 conveyed to an ink jet head corresponding to a side of a reference position for starting of printing on the cloth 1. As a result, the joint part detection sensors 21, 22 can be always positioned on the cloth 1 and detects a joint part 20 even when the cloths 1 have different widths.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink-jet printing apparatus, and more particularly, to an ink-jet printing apparatus which performs printing by discharging ink onto a cloth or the like.

[0002]

2. Description of the Related Art As one mode of an ink jet printing apparatus, there is known an apparatus which performs printing by discharging ink from an ink jet head onto a cloth or the like.

[0003] The fabric used for this printing is usually used as a continuous fabric obtained by joining several fabrics, and in this case, the seam portion of the continuous fabric is thicker than the other portions of the fabric. Has become. Therefore, when the seam portion passes through the portion of the ink jet head as the fabric is conveyed, the seam portion may come into contact with the ejection opening surface of the ink jet head and the ink jet head may be damaged.

On the other hand, for example, Japanese Patent Application Laid-Open No.
In Japanese Patent No. 1, as shown in FIG. 6, a pair of seam detection sensors 124a and 124b
On the upstream side of the print unit, the print medium is arranged at intervals in the width direction of the print medium. When these sensors detect the seam 119, the carriage is retracted to a predetermined position so that a predetermined amount of cloth can be fed at an idle speed. The possibility of interference between the connecting seam and the ink jet head was prevented beforehand. More specifically, these sensors 124a, 124b
Is a sensor of an optical reflection type, which detects a seam by detecting a black thread of the seam when conveying a white cloth, for example. Each sensor is configured to detect a seam with a delay of a predetermined amount or less in response to skew of cloth or the like.

[0005]

However, in the above-mentioned conventional example, a pair of seam detection sensors are arranged in the width direction of the conveyed print medium. The setup had to be changed and the position of the detection sensor had to be changed.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problem, and an object of the present invention is to detect a seam and to cope with a print medium of any width without performing the above-described setup change. Another object of the present invention is to provide an ink jet printing apparatus which does not reduce the operation rate of the apparatus due to the setup change and does not complicate the apparatus such as a mechanism required for the setup change.

[0007]

According to the present invention, there is provided:
An inkjet printing apparatus that performs printing by ejecting ink onto a print medium by using an inkjet head, and detects a seam of the print medium in a transport unit that transports the print medium and a transport path of the print medium by the transport unit. Detection means having a seam detection sensor disposed upstream of the inkjet head and corresponding to a position deviated to the printing start reference position side of the inkjet head in the transport path. It is characterized by having.

According to the above arrangement, the seam detection sensor for detecting the seam of the print medium is arranged corresponding to the position deviated to the print start reference position side in the print medium conveyance path. The sensor will be arranged at least on the side of the transport path where the print medium is present, so that the seam can always be detected regardless of the width of the print medium.

[0009]

Embodiments of the present invention will be described below in detail with reference to the drawings.

FIG. 1 is a schematic sectional view showing a schematic configuration of an ink jet printing apparatus according to an embodiment of the present invention.

Here, reference numeral 1 denotes a cloth as a print medium, and the cloth 1 is unwound in accordance with the rotation of the unwinding roller 2 of the unwinding section B, and includes a roller 3a and dust removing rollers 3b, 3b.
c, after being conveyed substantially horizontally by a conveyance section A provided at a portion facing the recording unit 4 via the wrinkle removing roller 3d and the intermediate rollers 3e and 3f, and then via the intermediate rollers 3g and 3h. To be taken up by the take-up roller 5.

The fabric 1 used in the present embodiment is:
As described above, some of the fabrics 1 are sewn and stitched together, and are unwound from the unwind roller 2. For this reason, the seam portion of the fabric 1 is thicker than other portions.

The transport section A is provided with an endless belt 9 between a drive roller 7 which can be driven and rotated in connection with a servomotor 6 and a rotatable driven roller 8, and the drive roller 7 is driven and rotated. The cloth 1 is conveyed by rotating the endless belt 9 counterclockwise in FIG. That is, an adhesive layer is formed on the surface of the endless belt 9, and the fabric 1 unwound from the unwinding roller 2 is applied to the endless belt 9 by the attaching roller 14.
And is conveyed without floating from the endless belt 9.

The endless belt 9 is disposed within a predetermined range facing the recording unit 4 so that the platen roller 1
The belt 9 is guided by Oa and 10b, and a suitable tension is applied to the belt 9 at that portion to convey the fabric 1 in the horizontal direction.

A pair of joint detection sensors 21 and 22 are provided on the upstream side of the two heads 4b in the transport path of the transport section in a positional relationship described later.

The recording unit 4 employs an ink jet recording method for recording by discharging ink from a recording head. In the recording unit 4, a carriage 4a is provided so as to be movable in a direction perpendicular to the plane of FIG. 1, and during this movement, printing is performed by two ink jet heads 4b attached to the carriage 4a. These ink jet heads are provided along the transport path of the fabric 1 as shown in the figure, whereby the same region of the fabric 1 is scanned in a superimposed manner, and complementary printing can be performed. The amount of one transport of the fabric 1 (hereinafter, also referred to as “transport pitch”) is determined by the two heads 4a according to the width of the scanning area and the pitch between the heads.

As described above, the cloth 1 conveyed in a state where the flatness is secured is applied with ink by the above-described head 4b of the recording unit 4 in the area between the platen rollers 10a and 10b, At the site, the film is peeled off from the conveyor belt 9 or the adhesive layer, and is wound up by the winding roller 5, and a drying process is performed by the drying heater 12 on the way. This drying heater 12
Is particularly effective when ink is used as a printing agent. The drying heater 12 may be of any suitable type, such as a type that blows warm air onto the cloth 1 and a type that irradiates infrared rays. At a position where the recording unit 4 can slide, an HS station 11 for correcting uneven density of the inkjet head 4b is provided.

In the above configuration, the unwind roller 2, the take-up roller 5, the drive roller 7, the driven roller 8, and the like are supported by a stand 15 integrated with a frame welding structure, which is the structure of the printing apparatus main body. I have. At a plurality of predetermined locations of the gantry 15, level pads 16 that enable the apparatus to be adjusted horizontally and vertically with respect to the installation floor are attached. Further, the recording unit 4 is provided so as to be movable in the horizontal direction, so that operability such as maintenance work such as belt replacement can be improved.

The unwinding roller 2 is configured to receive a tension by a clutch or the like (not shown) in a direction opposite to the unwinding of the fabric 1. Thereby, wrinkles can be extended by the wrinkle removing roller 3d without causing sagging of the cloth 1. On the other hand, the winding roller 5 is configured such that the cloth 1 receives tension in the winding direction by a clutch or the like (not shown). As a result, when the tension is reduced by feeding the fabric 1 by the belt 9, the fabric 1 is peeled off from the belt, and the fabric 1 is wound by the winding roller 5.

FIG. 2 shows the seam 20 of the fabric 1.
FIG. 4 is a diagram showing a positional relationship between the sensor and seam detection sensors 21 and 22.

The seam detection sensor 21 is provided on the upstream side with respect to the conveying direction, and the seam detection sensor 2 is provided on the downstream side thereof.
2 are provided. The interval is provided with a distance of the transport pitch P of the fabric 1. Here, the two seam detecting sensors 21 and 22 are provided on the left side in the transport direction of the fabric. This is because the print start reference position is the position on the left side, and even if the width of the
This is because the cloth 1 is always conveyed while the left side is aligned. Thus, even if the width of the fabric 1 changes, the position of the seam detection sensor does not need to be changed, and the seam can be detected satisfactorily regardless of the width of the fabric.

In the above configuration, while the cloth 1 is being conveyed,
A seam detection process is performed, and it is determined whether the seam detection sensor 21 detects the seam 20 or not. Then, when the seam 20 is detected, next, it is determined whether or not the seam detection sensor 22 detects the seam 20 when the fabric 1 is conveyed at a distance of the conveyance pitch P. Thus 2
When the two sensors detect the seam 20 at intervals at which the cloth 1 is intermittently fed, it is determined that the seam 20 has been correctly detected. Then, as described above, the control device 1
7 (see FIG. 1) correctly detects the seam 20,
The carriage 4a is retracted to a predetermined standby position such as a home position, and the cloth 1 is idle-fed N times a predetermined number of times. By appropriately setting the number N, the seam 20 is conveyed to a position beyond the two heads 4b by the N times of conveyance.

In the case described above, the seam detection sensor 21
If the second seam detection sensor 22 does not detect the seam 20 even if the seam 20 is detected and the cloth 1 is further conveyed with a distance of the conveyance pitch P, it is considered that the seam detection sensor 22 is abnormal. Stop printing operation such as conveyance. Similarly, if the seam detection sensor 21 does not detect the seam 20 and the second seam detection sensor 22 detects the seam 20, it is considered that the seam detection sensor 21 is abnormal. Stop.

It should be noted that the seam 20 is often formed obliquely at an angle θ as shown in FIG.
FIG. 3 shows a case where the cloth 1 is inclined toward the downstream side in the transport direction with reference to the left side.

In this case, even if the seam detection sensor 21 detects the seam 20 and the cloth 1 is conveyed at a distance of the conveyance pitch P and the seam detection sensor 22 detects the seam 20 correctly, The seam 20 precedes by a distance H on the downstream side in the transport direction.
Therefore, the distance between the downstream seam detection sensor 22 and the upstream head needs to be as shown in FIG. Seam 20
A value of -1 indicates a state of stopping immediately before the joint detection sensor 21. Next, when transported with a distance of the transport pitch P,
The seam stops at position 20-2. At this time, it passes through the seam detection sensor 21, and the seam is detected by the seam detection sensor 21. When the sheet is further conveyed with a distance of the conveying pitch P, the seam is detected by the seam detection sensor 22 and the seam stops at the position 20-3. When this state correctly detects the seam, the seam is most likely to be the head 4b.
When approaching. At this time, the downstream side of the seam is the head 4
In order not to interfere with b, it is necessary to set l ₁ as follows.

[0026]

## EQU1 ## l ₁ > H + P (1) Therefore, the number N of times of idle feeding needs to be set as follows.

[0027]

N ≧ (l ₁ + l ₂ ) / P (2) Further, when the joint 20 is inclined to the upstream side in the transport direction with reference to the left side of the cloth 1, the result is as shown in FIG. The joint 20-1 shows a state where the joint 20-1 is stopped immediately before the joint detection sensor 21. Next, when the sheet is conveyed with a distance of the conveyance pitch P, the joint stops at the position of 20-2. At this time, it passes through the seam detection sensor 21, and the seam is detected by the seam detection sensor 21. When the sheet is further conveyed with a distance of the conveying pitch P, the seam is detected by the seam detection sensor 22 and the seam stops at the position 20-3.
This state is a case where the seam is closest to the head 4b when the seam is correctly detected. To the downstream side of the case seam does not interfere with the head 4b, it is necessary to set a l ₁ as follows.

[0028]

L ₃ > H (3) Therefore, the number N of times of idle feeding needs to be set as follows.

[0029]

N ≧ (l ₁ + l ₃ ) / P (4) Normally, it is not known whether the seam 20 is skewed downstream or upstream in the transport direction. It is desirable to set according to the formula.

(Others) It should be noted that the present invention includes a means (for example, an electrothermal converter or a laser beam) for generating thermal energy as energy used for performing ink ejection, particularly in an ink jet recording system. An excellent effect is obtained in a recording head and a recording apparatus of a type in which the state of ink is changed by the thermal energy. This is because according to such a method, it is possible to achieve higher density and higher definition of recording.

The typical configuration and principle are described in, for example, US Pat. Nos. 4,723,129 and 4,740.
It is preferable to use the basic principle disclosed in the specification of Japanese Patent No. 796. This method is a so-called on-demand type,
Although it can be applied to any type of continuous type, in particular, in the case of the on-demand type, it can be applied to a sheet holding liquid (ink) or an electrothermal converter arranged corresponding to the liquid path. By applying at least one drive signal corresponding to the recorded information and providing a rapid temperature rise exceeding nucleate boiling, heat energy is generated in the electrothermal transducer, and film boiling occurs on the heat acting surface of the recording head. Liquid (ink) corresponding to this drive signal on a one-to-one basis.
This is effective because air bubbles inside can be formed. The liquid (ink) is ejected through the ejection opening by the growth and contraction of the bubble to form at least one droplet. When the drive signal is formed into a pulse shape, the growth and shrinkage of the bubble are performed immediately and appropriately, so that the ejection of a liquid (ink) having particularly excellent responsiveness can be achieved, which is more preferable. As the pulse-shaped drive signal, those described in US Pat. Nos. 4,463,359 and 4,345,262 are suitable. Further, if the conditions described in US Pat. No. 4,313,124 relating to the temperature rise rate of the heat acting surface are adopted, more excellent recording can be performed.

As the configuration of the recording head, in addition to the combination of the discharge port, the liquid path, and the electrothermal converter (linear liquid flow path or right-angle liquid flow path) as disclosed in the above-mentioned respective specifications, U.S. Pat. No. 4,558,333 and U.S. Pat. No. 44,558 which disclose a configuration in which a heat acting portion is arranged in a bending region.
A configuration using the specification of Japanese Patent No. 59600 is also included in the present invention. In addition, Japanese Unexamined Patent Application Publication No. 59-123670 discloses a configuration in which a common slit is used as a discharge portion of an electrothermal converter for a plurality of electrothermal converters, and an aperture for absorbing a pressure wave of thermal energy is provided. The effect of the present invention is effective even if the configuration is based on JP-A-59-138461, which discloses a configuration corresponding to a discharge unit. That is, according to the present invention, recording can be reliably and efficiently performed regardless of the form of the recording head.

Further, the present invention can be effectively applied to a full-line type recording head having a length corresponding to the maximum width of a recording medium on which a recording apparatus can record. Such a recording head may have a configuration that satisfies the length by a combination of a plurality of recording heads, or a configuration as one integrally formed recording head.

In addition, even in the case of the serial type as described above, a recording head fixed to the apparatus main body or an electric connection with the apparatus main body or ink from the apparatus main body by being mounted on the apparatus main body. The present invention is also effective when a replaceable chip-type recording head that can be supplied or a cartridge-type recording head in which an ink tank is provided integrally with the recording head itself is used.

It is preferable to add a discharge recovery means for the print head, a preliminary auxiliary means, and the like as the structure of the printing apparatus of the present invention since the effects of the present invention can be further stabilized. If these are specifically mentioned, the recording head is heated using capping means, cleaning means, pressurizing or suction means, an electrothermal transducer, another heating element or a combination thereof. Pre-heating means for performing the pre-heating and pre-discharging means for performing the discharging other than the recording can be used.

The type and number of recording heads to be mounted are not limited to those provided only for one color ink, for example, and for a plurality of inks having different recording colors and densities. A plurality may be provided. That is, for example, the printing mode of the printing apparatus is not limited to a printing mode of only a mainstream color such as black, but may be any of integrally forming a printing head or a combination of a plurality of printing heads. The present invention is also very effective for an apparatus provided with at least one of the recording modes of full color by color mixture.

In addition, in the embodiments of the present invention described above, the ink is described as a liquid. However, an ink which solidifies at room temperature or lower and which softens or liquefies at room temperature may be used. In general, the ink jet method generally controls the temperature of the ink itself within a range of 30 ° C. or more and 70 ° C. or less to control the temperature so that the viscosity of the ink is in a stable ejection range. Sometimes, the ink may be in a liquid state. In addition, in order to positively prevent temperature rise due to thermal energy by using it as energy for changing the state of the ink from a solid state to a liquid state, or to prevent evaporation of the ink, the ink is solidified in a standing state and heated. May be used. In any case, the application of heat energy causes the ink to be liquefied by the application of the heat energy according to the recording signal and the liquid ink to be ejected, or to start solidifying when it reaches the recording medium. The present invention is also applicable to a case where an ink having a property of liquefying for the first time is used. In such a case, the ink
JP-A-54-56847 or JP-A-60-7
As described in Japanese Patent Publication No. 1260, it is also possible to adopt a form in which the sheet is opposed to the electrothermal converter in a state where it is held as a liquid or solid substance in the concave portion or through hole of the porous sheet. In the present invention, the most effective one for each of the above-mentioned inks is to execute the above-mentioned film boiling method.

In addition, the form of the ink jet recording apparatus of the present invention is not only used as an image output terminal of an information processing apparatus such as a computer, but also for a copying apparatus combined with a reader or the like, and a facsimile apparatus having a transmission / reception function. It may take a form.

[0039]

As described above, according to the present invention,
Since the seam detection sensor for detecting the seam of the print medium is arranged corresponding to the position deviated to the print start reference position side in the print medium conveyance path, the seam detection sensor has at least the print medium in the conveyance path. This makes it possible to always detect the seam regardless of the width of the print medium.

As a result, it is possible to omit operations such as changing the position of the sensor according to the width of the print medium to be used, and a mechanism therefor.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view schematically illustrating a schematic configuration of an inkjet printing apparatus according to an embodiment of the present invention.

FIG. 2 is a diagram showing a relationship between a seam of a fabric and a seam detection sensor according to the embodiment of the present invention.

FIG. 3 is a diagram for explaining control related to seam detection in the above embodiment in which skew of a seam is considered.

FIG. 4 is a diagram illustrating a positional relationship between a head and a sensor when a seam is skewed downstream.

FIG. 5 is a diagram illustrating a positional relationship between a head and a sensor when a seam is skewed upstream.

FIG. 6 is a diagram showing a configuration of a conventional example using a seam detection sensor.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 cloth 2 unwind roller 3 roller 4 recording unit 4a carriage 4b inkjet head 5 take-up roller 6 drive motor 7 drive-side transfer roller 8 driven-side transfer roller 9 transfer belt 10a, 10b platen roller 11 HS station 12 drying heater 13 brake 14 Sticking roller 15 Mount 16 Level pad 17 Controller 20 Seam 21 Seam detection sensor 22 Seam detection sensor

Claims (6)

[Claims] 1. An ink jet printing apparatus which performs printing by discharging ink onto a print medium using an ink jet head, comprising: transport means for transporting the print medium; A sensor for detecting a seam of the medium,
A detection means having a seam detection sensor disposed at an upstream side of the ink jet head and corresponding to a position deviated to a printing start reference position side of the ink jet head in the transport path. Printing device. 2. The printing apparatus according to claim 1, further comprising control means for retreating the ink jet head from the print position when the detection means detects a seam of the print medium, and for carrying the print medium by a predetermined amount by the transfer means. The inkjet printing apparatus according to claim 1, wherein: 3. The ink jet printing apparatus according to claim 1, wherein a pair of the seam detection sensors are arranged in a conveying direction of the print medium. 4. The printing apparatus according to claim 3, wherein the pair of joint detection sensors has an interval of a distance equal to a single transport amount during a printing operation by the transport unit.
5. The inkjet printing apparatus according to claim 1. 5. The ink jet printing apparatus according to claim 1, wherein the print medium is a cloth. 6. The ink-jet printing apparatus according to claim 1, wherein the ink-jet head generates bubbles in the ink using thermal energy and discharges the ink by the pressure of the bubbles. .