EP4620688A1

EP4620688A1 - Printing apparatus and printing system

Info

Publication number: EP4620688A1
Application number: EP25162926.7A
Authority: EP
Inventors: Masanori Hirano
Original assignee: Ricoh Co Ltd
Current assignee: Ricoh Co Ltd
Priority date: 2024-03-22
Filing date: 2025-03-11
Publication date: 2025-09-24
Also published as: JP2025146278A

Abstract

A printing apparatus (100) includes a head (30), a carriage (20), a conveyor (50), and a controller (500). The head (30) discharges liquid on a medium held by a medium holder (10). The carriage (20) is mounted with the head (30). The conveyor (50) rotates in forward and reverse directions to convey the medium holder (10). The controller (500) performs a front operation mode and a continuous printing mode. The medium holder (10) is attachable to and detachable from the conveyor (50). In the front operation mode, the controller (500) causes the conveyor (50) to move a single medium holder (10) inserted from a front side of the printing apparatus (100) back and forth. In the continuous printing mode, the controller (500) causes the conveyor (50) to move a plurality of medium holders sequentially inserted from a back side of the printing apparatus (100) in one direction.

Description

BACKGROUND

Technical Field

Embodiments of the present disclosure relate to a printing apparatus and a printing system.

Related Art

Direct to garment (DTG) printers perform printing directly on clothes such as T-shirts and on fabrics such as tote bags, hats, and shoes by an inkjet method.
In printing using a stand-alone type DTG printer, the process of mounting a medium such as a T-shirt on a platen stage from a front side of an apparatus, performing application of ink by repeating reloading a plurality of times, and taking out the medium on which printing is completed from the front side of the apparatus is performed. In a case where a plurality of media are printed, the printing of a subsequent medium can be performed only after the printing of a preceding medium is completed, which causes an inconvenience that the productivity in performing a large amount of printing.
In order to solve this problem, a system has been proposed that includes a plurality of printers and a platen conveying mechanism. In the system, a central processing unit (CPU) executes a determination step of determining to which of the plurality of printers the platen is to be conveyed, avoids the conveyance of the platen only to a specified printer, and increases the number of print processes in a certain period of time (e.g., see Japanese Unexamined Patent Application Publication 2021-102505 ).
According to the system of Japanese Unexamined Patent Application Publication 2021-102505 , it is expected that the productivity is enhanced and the work load of an operator is reduced by automatically controlling the conveyance of the platen. However, the system is an automatically controllable system in which a plurality of printers are connected. Thus, a high introduction cost is required, and a wide installation space is required. On the other hand, when the number of print processes is small, some printers are not operated, and thus an inconvenience that performing a flexible operation suitable for the scale is difficult may occur.

SUMMARY

The present disclosure is made to solve the above-described disadvantage. An object of the present disclosure is to provide a printing apparatus that can enhance productivity without increasing cost and installation space and can be flexibly operated.
In an embodiment of the present disclosure, a printing apparatus includes a head, a carriage, a conveyor, and a controller. The head discharges liquid on a medium held by a medium holder. The carriage is mounted with the head to move back and forth in a main scanning direction. The conveyor rotates in forward and reverse directions to convey the medium holder in a sub-scanning direction in response to scanning of the head. The controller performs a front operation mode and a continuous printing mode. The medium holder is attachable to and detachable from the conveyor in a state the medium is held on the medium holder. In the front operation mode, the controller causes the conveyor to move a single medium holder inserted from a front side of the printing apparatus back and forth. In the continuous printing mode, the controller causes the conveyor to move a plurality of medium holders sequentially inserted from a back side of the printing apparatus in one direction.
In another embodiment of the present disclosure, a printing system includes the printing apparatus that prints the medium and a conveyor drying apparatus that dries the medium printed by the printing apparatus.
According to the present disclosure, it is possible to provide a printing apparatus that can enhance productivity without increasing cost and installation space and can be flexibly operated.

BRIEF DESCRIPTION OF THE DRAWINGS

A more complete appreciation of embodiments of the present 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 schematic diagram illustrating a configuration of a DTG printer according to a comparative example;
FIG. 2 is a schematic diagram illustrating a configuration of a printing apparatus according to an embodiment of the present disclosure;
FIG. 3 is a schematic diagram illustrating another configuration of a printing apparatus according to an embodiment of the present disclosure;
FIG. 4 is a schematic view of a printing system in which a printing apparatus according to an embodiment of the present disclosure and a conveyor heater are combined;
FIGS. 5A and 5B are perspective views illustrating an example of a medium holder;
FIG. 5C is a perspective view of a medium holder on which a medium is mounted;
FIG. 6A is a schematic view of an operation panel;
FIG. 6B is a schematic view of an operation panel;
FIGS. 7A to 7D are diagrams illustrating a relation between the position of a medium holder on a conveyance surface and the amount of line feed;
FIGS. 8A to 8D are diagrams illustrating another relation between the position of a medium holder on a conveyance surface and the amount of line feed;
FIG. 9 is a diagram illustrating an example of a guide;
FIGS. 10A and 10B are diagrams illustrating an example of a guide and a surface of a medium holder which faces a conveyance surface;
FIGS. 11A to 11C are diagrams illustrating another example of a guide and a surface of a medium holder which faces a conveyance surface;
FIG. 12A to 12C are diagrams illustrating another example of a guide and a surface of a medium holder which faces a conveyance surface;
FIG. 13 is a diagram illustrating a configuration of a printing apparatus according to an embodiment of the present disclosure;
FIG. 14 is a diagram illustrating an example of a guide;
FIG. 15 is a diagram illustrating a configuration of a printing apparatus according to an embodiment of the present disclosure;
FIG. 16 is a flowchart of a procedure of determination of a print mode;
FIG. 17 is a block diagram illustrating an outline of a controller of a printing apparatus according to an embodiment of the present disclosure;
FIG. 18A is a perspective view of a printing unit included in a printing apparatus according to an embodiment of the present disclosure; and
FIG. 18B is a diagram illustrating a configuration example of a head.

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. Also, identical or similar reference numerals designate identical or similar components throughout the several views.

DETAILED DESCRIPTION

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.
Referring now to the drawings, embodiments of the present disclosure are described below. Like reference signs are assigned to like elements or components and descriptions of those elements or components may be simplified or omitted. 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.
A description is given below of a printing apparatus 100 according to an embodiment of the present disclosure with reference to drawings. The present disclosure is not limited to the following embodiments, but can be changed within the range that can be conceived of by those skilled in the art, such as other embodiments, additions, modifications, deletions, and the scope of the present disclosure encompasses any aspect as long as the aspect achieves the operation and advantageous effect of the present disclosure. In the present specification, the terms "image formation," "recording," "printing," and "image printing," used herein may be used synonymously with each other.
The printing apparatus 100 according to the present embodiment is a serial type inkjet printer, for example, a DTG printer that forms an image on a fabric medium such as a T-shirt. In the following description, the printing apparatus 100 according to the present embodiment is also referred to as a "DTG printer."
A description is given of an example of a printing unit included in the printing apparatus 100 according to the present embodiment. FIG. 18A is a perspective diagram illustrating an example of the printing unit of the present embodiment. In FIG. 18A, X indicates a main scanning direction, Y indicates a sub-scanning direction, and Z indicates an up-and-down direction (a vertical direction or a height direction).
The printing apparatus 100 according to the present embodiment includes a head 30 that discharges liquid onto a medium held by a medium holder 10, a carriage 20 that mounts the head 30 and moves back and forth in the main scanning direction X, and a conveyor that conveys the medium holder 10 in a sub-scanning direction Y in response to the scanning of the head 30. The medium holder 10 is attachable to and detachable from the conveyor in a state of holding the medium. FIG. 18A illustrates an example of the printing apparatus 100 including the two carriages 20 (a first carriage 20a and a second carriage 20b). However, the number of carriages is not limited to two, and may be one, or three or more.
Guide rods (a main guide rod 21 and a sub guide rod 22) hold the carriage 20 such that the carriage 20 is movable back and forth in the main scanning direction X. FIG. 18A illustrates an example of the printing apparatus 100 in which the carriage 20 is held by the main guide rod 21 and the sub guide rod 22. However, the configuration of the guide rods is not limited thereto, and the carriage 20 may be held by one guide rod.
The carriage 20 is coupled to a timing belt 27 looped around a drive pulley and a driven pulley. The drive pulley is rotated by a main scanning motor rotatable in forward and reverse directions. The main scanning motor is driven to move the carriage 20 back and forth in the main scanning direction X.
An encoder sheet 25 is disposed along the main scanning direction X. The encoder sheet 25 has periodic slits, and the carriage 20 includes a reading sensor for reading the slits of the encoder sheet 25. Thus, the DTG printer can detect the position of the carriage 20 in the main scanning direction X from a reading result of the reading sensor.
A controller board 7 processes and controls, for example, the operation (output) of a motor and a solenoid, and an input signal of a sensor to control liquid discharge. For example, the controller board 7 performs print control of print data transmitted from a personal computer (PC) and reads print data recorded in a universal serial bus (USB) memory to perform print control processing.
A plurality of heads 30 are mounted on the carriage 20. Each head 30 has nozzles arranged in the sub-scanning direction. The carriage 20 also includes a head tank that temporarily stores ink as a liquid to be supplied to the head 30. The head tank is coupled to an ink cartridge 8 via a supply tube and a supply pump.
The printing apparatus 100 may include an unevenness detector 67 that detects unevenness on the surface of the medium mounted on the medium holder 10 to be conveyed. The unevenness detector 67 is, for example, a position sensor that detects the position of the medium in the Z direction. For example, when the position sensor detects that the surface of the medium is at a height at which the surface of the medium contacts the nozzle face of the head 30, a controller 500 performs control to stop the conveyance of the medium holder 10 as an error.
A maintenance unit 23 (maintenance recovery mechanism) is disposed on one end of the range of movement of the carriage 20 in the main scanning direction X to maintain and recover the head 30. The maintenance unit 23 includes a moisture-retentive cap and a suction cap for protecting the head 30 from drying when the printing apparatus 100 is not operating (not forming an image). The suction cap is coupled to a suction pump. The maintenance unit 23 includes a wiper for removing excess ink remaining on the nozzle face of the head 30 to recover the condition of the nozzle face of the head 30. A discharge receptacle 26 is disposed on the other end of the range of movement of the carriage 20 in the main scanning direction X.
When the image formation starts, the printing apparatus 100 moves the medium holder 10 to a start position of the image formation. Then, the head 30 discharges liquid while the carriage 20 moves once in the main scanning direction X. The controller 500 causes the conveyor to move in the sub-scanning direction Y by a specified amount for the next image formation at a timing at which one movement of the carriage 20 is completed.
The conveyor is a conveyor that can be driven to rotate in forward and reverse directions. The conveyor may be a belt conveyor including an endless belt stretched over a driver that can be driven to rotate in forward and reverse directions, or may be a chain conveyor or a roller conveyor. An operation in which the conveyor (e.g., the conveyor belt 50) conveys the medium in the sub-scanning direction Y in response to the scanning of the head 30 is referred to as a "line feed operation." The distance of movement of the medium in the sub-scanning direction Y in one line feed operation (i.e., a movement distance per operation) is referred to as an "amount of line feed."
A front operation panel 40 (front scanning panel) is disposed on a front face of a body of the printing apparatus 100. The front operation panel 40 includes an operation unit for inputting various settings and a display unit for displaying information. The operation unit and the display unit may be separately disposed on the front face. Alternatively, the operation unit such as a pressure-sensitive or electrostatic capacitance transparent film switch is overlaid on the display unit such as a liquid crystal display to form a touch panel.
FIG. 18B is a diagram illustrating a configuration of the plurality of heads 30 mounted on the carriage 20. In FIG. 18B, X indicates the main scanning direction, and Y indicates the sub-scanning direction.
As illustrated in FIG. 18B, the first carriage 20a is held by a guide rod 21a, and the second carriage 20b is held by a guide rod 21b, to be movable back and forth in the main scanning direction X. In the following description, multiple carriages are collectively referred to as "carriages 20," and multiple guide rods are collectively referred to as "guide rods 21". The head 30 mounted on the carriage 20 moves in the main scanning direction X along with the movement of the carriage 20.
In the configuration example of the head 30 illustrated in FIG. 18B, the head 30 mounted on the first carriage 20a is a head that discharges colored ink (in the following description, referred to as "color ink 32") other than white from nozzles. The head 30 mounted on the second carriage 20b is a head that discharges white ink 31 from nozzles.
The term "color ink" means a combination of any colored inks other than white. The configuration described above includes a combination of heads that discharge ink for color printing. Specifically, a head for cyan (C) ink, a head for magenta (M) ink, a head for yellow (Y) ink, and a head for black (K) ink are mounted on the carriage 20. The order of arrangement of the heads is not limited to this configuration. The types of colors are not limited to the example of FIG. 13B, and five or more colors including a special color ink may be used.
A certain DTG printer performs color printing after forming a foundation with white ink on a medium other than white media to form vivid color images.
Aspects of the head 30 include an integrated head unit that discharges liquids of different colors from the respective nozzle rows. The aspects of the head 30 also include a head that discharges pretreatment liquid from nozzles.
FIG. 1 illustrates an example of a configuration of a DTG printer according to a comparative example. FIG. 1 illustrates a typical desktop type DTG printer, which includes a serial-scanning-type inkjet head 30 and performs printing by scanning the inkjet head 30 in a direction (main scanning direction) orthogonal to a conveyance direction (sub-scanning direction) of a medium M, similarly to an inkjet printer for consumers and a wide format printer for sign graphics.
A platen 80 that holds the medium M (for example, a T-shirt) is fixed to a stage 81. The stage 81 moves back and forth on a rail 82 in the directions of an arrow D1 by the movement of a stage feed belt in the directions of an arrow D2. The aspect of conveyance of the medium M is different from the aspect in the inkjet printer described above. The platen 80 on which the medium M1 is mounted on the front side of the body of the DTG printer moves to the back side of the body of the DTG printer, and printing is performed while the platen 80 moves back and forth to the front side of the body of the DTG printer again. When white ink is mounted, the conveyance (back and forth movement) of the medium and the printing operation are repeated in each of the white ink printing and the color printing. A medium M2 on which printing is completed is removed from the platen 80 on the front side of the body of the DTG printer.
The medium M which is a fabric has various thicknesses and shapes depending on the tailoring, and the shape may be distorted during conveyance. Thus, an operator manually mounts the medium M on the platen 80 each time. As described above, the DTG printer according to a comparative example is a "front operation" type printing apparatus in which the mounting of the medium M on the platen 80 and the operation of the printing apparatus are performed only on the front side of the printing apparatus.
On the other hand, the printing apparatus (DTG printer) 100 according to the present embodiment uses a medium holder which is attachable to and detachable from the conveyor in a state of holding the medium M, and includes the conveyor which can be driven to rotate in forward and reverse directions as the conveyor of the medium holder. A description is given below of the printing apparatus 100 according to the present embodiment.
Examples of the printing apparatus 100 according to the present embodiment are illustrated in FIGS. 2 and 3. The printing apparatus 100 according to the present embodiment includes the head 30, the carriage 20, and the conveyor. The head 30 discharges liquid onto the medium M held by the medium holder 10. The carriage 20 mounts the head 30 and moves back and forth in the main scanning direction. The conveyor conveys the medium holder 10 in the sub-scanning direction in response to the scanning of the head 30. The medium holder 10 is attachable to and detachable from the conveyor in a state of holding the medium M. The conveyor is a conveyor that can be driven to rotate in forward and reverse directions. A description is given below of an example of a belt conveyor including an endless belt stretched over a driver that can be driven to rotate in forward and reverse directions, but the conveyor is not limited thereto, and may be a chain conveyor or a roller conveyor.
The printing apparatus 100 according to the present embodiment can also operate in a front operation mode and a continuous printing mode. In the front operation mode, a single medium holder 10 is inserted from the front side of the printing apparatus 100 and the medium holder 10 is moved back and forth by the conveyor. In the continuous printing mode, a plurality of medium holders 10 (10a and 10b) are inserted sequentially from the back side of the printing apparatus 100 and each of the plurality of medium holders 10 is moved in one direction by the conveyor.
FIG. 2 is a diagram illustrating an example of the front operation mode. The printing apparatus 100 according to the present embodiment includes a rear cover 12 which is attachable to and detachable from a body portion 11 of the printing apparatus 100 on the back side of the printing apparatus 100. When the rear cover 12 is attached, only the front operation mode can be executed. The conveyor as a conveying means is rotatable in forward and reverse directions indicated by an arrow D4, and the medium holder 10 is also movable back and forth in the directions of an arrow D3.
When the printing apparatus 100 according to the present embodiment is used in a stand-alone manner, it is assumed that the front operation mode is typically performed. An opening on the back side is closed by mounting the rear cover 12, and the medium holder 10 cannot be inserted. Thus, the occurrence of an operation error can be prevented. The rear cover 12 is attached to the printing apparatus 100 so that intrusion of dust, dirt, and foreign matter from the back side can be prevented. Further, the effect of preventing an accident due to insertion of a finger can be obtained.
The attachment and detachment of the rear cover 12 and the selection of the printing mode can be interlocked. The rear cover 12 is attached to the printing apparatus 100 so that the continuous conveyor printing mode cannot be executed. The setting for executing only the front operation mode is made when the rear cover 12 is attached to the printing apparatus 100cover 12 is attached to the printing apparatus 100 so that the work load of mode selection and setting by an operator can be reduced.
FIG. 3 is a diagram illustrating an example of a continuous printing mode (continuous conveyor printing mode). The conveyor serving as a conveying means rotates in the direction indicated by an arrow D6 in FIG. 3, and the medium holder 10 moves only in the direction indicated by an arrow D5. In the example illustrated in FIG. 3, the conveyor is a belt conveyor including a guide 51 for positioning the medium holder 10 on the conveyance surface, and the conveyor belt 50 (an endless belt) stretched around a conveyor motor 16 (a driver) that can drive in the forward and reverse directions.
The medium holder 10 holding the medium M1 is inserted from the back side, and the medium holder 10 holding the printed media M2 is ejected from the front side of the printing apparatus 100. The medium holder 10 is used repeatedly after the medium M2 is taken out from the medium holder 10.
In the continuous printing mode, when a line feed amount per line feed operation in which the conveyor moves the medium holder 10 in the sub-scanning direction in response to the scanning of the head 30 is p, a conveyance amount W by which a subsequent medium holder 10b is conveyed in the sub-scanning direction from the last scanning of the head 30 for one medium M held by a preceding medium holder 10a to the first scanning of the head 30 for another medium M held by the subsequent medium holder 10b satisfies a relation of W = p × n (n is an integer of one or more).
It is preferable that the conveyance interval of the plurality of medium holders 10 (10a and 10b) on the conveyance surface is n times (n is an integer of one or more) of the line feed amount p. For example, when the medium holder 10 is set on the conveyance surface, the medium holder 10 is positioned by the guides 51 disposed at intervals of n times the line feed amount. Thus, the conveyance condition satisfying the relation of W = p × n can be achieved.
From the viewpoint of convenience of operation in the continuous printing mode, it is preferable that an operation panel (a rear operation panel 41) is disposed on the back side of the printing apparatus 100.
FIG. 4 is a diagram illustrating an example of the printing system including the printing apparatus 100 according to the present embodiment, and a conveyor drying apparatus that is disposed downstream from the printing apparatus 100 to heat and dry a medium after printing. The conveyor drying apparatus is not limited to any particular type and may be, for example, an apparatus including a heating-and-drying device 61 and a heater conveyor 60 that can convey the medium holder 10 as illustrated in FIG. 4. Alternatively, the printing apparatus 100 may be combined with a commercially available device (for example, Big Buddy III manufactured by BBC Industries, Inc.). In the printing apparatus 100 according to the present embodiment, the continuous printing mode is selected, and the conveyance surface of the conveyor drying apparatus and the conveyance surface of the conveyor of the printing apparatus 100 according to the present embodiment are adjusted to be at the same height, thus allowing printing and drying to be continuously and smoothly performed on a plurality of media M.
FIGS. 5A and 5B are perspective views illustrating an example of the medium holder 10. The medium holder 10 includes a platen 5 that holds, in a flat state, a portion of a medium M on which printing is performed, and an outer peripheral cover 6 that is openable and closable. The outer peripheral cover 6 has an opening portion at a portion corresponding to the platen 5, and has a structure in which the medium M is sandwiched and fixed by the peripheral edge of the platen 5 and the outer peripheral cover 6. FIG. 5C illustrates a state in which a medium M is set on the medium holder 10. A surplus portion Ma is a portion of the medium M that is not a printing target, and corresponds to, for example, a sleeve, a neck, or a hem in a case where recording is performed on a front surface of a T-shirt.
The medium holder 10 is heated by a conveyor drying apparatus in, for example, the printing system illustrated in FIG. 4, and thus, preferably has heat resistance of about 200°C.
FIG. 6 is a diagram illustrating an example of the operation panel. The printing apparatus 100 according to the present embodiment includes the front operation panel 40 disposed on the front side of the printing apparatus 100 and/or the rear operation panel 41 disposed on the back side of the printing apparatus 100. When the DTG printer is operated, there are a case where the DTG printer is connected to an external device such as a PC to perform control and a case where print data is acquired via a network or using an external storage such as a USB memory and an operation is performed using an operation panel disposed in a body of the DTG printer. In the latter case, it is preferable that the operation panel is a highly functional operation panel that can perform, for example, the setting of a printing mode and the setting for performing a maintenance operation (maintenance-and-recovery operation). The printing apparatus 100 according to the present embodiment includes such a highly functional operation panel.
FIG. 6A is a diagram illustrating an example of the front operation panel 40 disposed on the body of the printing apparatus 100, and FIG. 6B is a diagram illustrating an example of the operation panel that is attachable and detachable and applicable as the rear operation panel 41. For example, the attachable-and-detachable operation panel illustrated in FIG. 6B can be attached on the front side of the printing apparatus 100 in the front operation mode and can be attached on the back side of the printing apparatus 100 in the continuous printing mode. In this case, the print mode can be switched (one print mode can be locked) according to the installation position of the operation panel.
In the aspect in which the front operation panel 40 and the rear operation panel 41 are disposed in a non-attachable-and-detachable manner, when one of the operation panels is enabled, flip-flop control may be performed such that the other operation panel is locked. The front operation mode is performed in response to an input from the front operation panel 40, and the continuous printing mode is performed in response to an input from the rear operation panel 41. Thus, an operation error can be prevented.
FIGS. 7A to 7D are diagrams illustrating a relation between the position of the medium holder 10 on the conveyance surface and the line feed amount p when the head 30 performs multi-pass recording in which scanning is performed a plurality of times. In FIGS. 7A to 7D, the line feed amount p is indicated by dashed lines. As an example of completing printing on a medium by eight times of scanning of the head 30, FIG. 7A illustrates the position of the medium holder 10 in the first scanning, FIG. 7B illustrates the position of the medium holder 10 in the second scanning, FIG. 7C illustrates the position of the medium holder 10 in the eighth scanning, and FIG. 7D illustrates the position of the medium holder 10 in the ninth scanning. In the multi-pass recording in the printing apparatus 100 according to the present embodiment, the conveyance (sub-scanning) of the medium holder 10 is performed by the uniform line feed amount p.
FIGS. 8A to 8D are diagrams illustrating the positions of a plurality of medium holders 10 (10a and 10b) in the sub-scanning direction when the medium holders 10 (10a and 10b) are set on the conveyance surface in the continuous printing mode. In FIGS. 7A to 7D, the line feed amount p is indicated by dashed lines. FIGS. 8A to 8D are diagrams illustrating an example in which printing on a medium is completed by eight times of the scanning of the head 30 as the multi-pass recording.
FIGS. 8A and 8B are diagrams illustrating an example in which two medium holders 10 (10a and 10b) are set at a conveyance interval of an integer multiple of the line feed amount p, and the conveyance (sub-scanning) of the medium holders 10 is performed at the equal line feed amount p. FIG. 8A is a diagram illustrating a state in which the eighth scanning is performed on a medium on the preceding medium holder 10a and printing is completed, and FIG. 8B is a diagram illustrating a state in which the tenth scanning is performed on a medium on the preceding medium holder 10a and the subsequent medium holder 10b has reached the print start position.
FIGS. 8A and 8B illustrates an example in which the distance between the rear end of the preceding medium holder 10a and the front end of the subsequent medium holder 10b is 4p. When the length of the medium holder 10 is L, the length L is an integer multiple of the line feed amount p, and the conveyance interval of L + 4p is an integer multiple of the line feed amount p. The timing at which the subsequent medium holder 10b set at an interval of an integer multiple of the line feed amount p reaches the print start position is the same as the timing of the preceding medium holder 10a. Thus, printing can be performed using the same print data without adjusting the print start timing each time.
On the other hand, FIGS. 8C and 8D are comparative examples, and illustrate an example in which two medium holders 10 (10a and 10b) are set at a conveyance interval which is not an integer multiple of the line feed amount p, and the conveyance (sub-scanning) of the medium holders 10 is performed at the equal line feed amount p. As illustrated in FIGS. 8C and 8D, the leading end T of the subsequent medium holder 10b is deviated from a position at which the distance from the rear end of the preceding medium holder 10a is an integer multiple of the line feed amount p. FIG. 8C is a diagram illustrating a state in which the eighth scanning is performed on the medium of the preceding medium holder 10a and printing is completed. FIG. 8D is a diagram illustrating a state in which the tenth scanning is performed on the medium of the preceding medium holder 10a.
The timing at which the subsequent medium holder 10b set at a conveyance interval that is not an integer multiple of the line feed amount p reaches the print start position differs from the timing of the preceding medium holder 10a. Thus, print data needs to be regenerated. This is because, in the serial type printing apparatus, print data is generated by associating the nozzle position with the position of the print image for each scanning of the head.
In the printing apparatus 100 according to the present embodiment, when the medium holder 10 is set on the conveyance surface in the continuous printing mode, the medium holder 10 is positioned by the guides 51 disposed at the intervals of the integer multiple of the line feed amount p. Thus, the conveyance interval of the plurality of medium holders 10 on the conveyance surface can be set to the integer multiple of the line feed amount p per line feed operation in which the conveyor moves the medium holder 10 in the sub-scanning direction in response to the scanning of the head 30. Examples of the guides 51 are illustrated in FIGS. 9, 10A, 10B, 11A, 11B, 11C, 12A, 12B, and 12C.
A guide 51a illustrated in FIG. 9 has a visible pattern formed on the conveyance surface of the conveyor belt 50. The pattern is not limited to the linear pattern illustrated in FIG. 9, and may be any pattern that can be visually recognized to appropriately arrange the leading end of the medium holder 10. The method of forming the pattern on the conveyor belt 50 is not particularly limited, and any method capable of marking may be used. Examples thereof include line printing.
When the medium holder 10 is visually aligned with the guide 51a, the positional accuracy of the medium holder 10 may be lessened. However, in DTG printing, a deviation of about several millimeters to several tens of millimeters may be allowed.
A guide 51b illustrated in FIG. 10A is a convex portion or a concave portion formed on the conveyance surface of the conveyor belt 50. As illustrated in FIG. 10B, the corresponding medium holder 10 has a concave portion or a convex portion (reference sign 13) that fits with the guide 51b on the surface facing the conveyance surface. In particular, when the guide 51b is a convex portion, the medium holder 10 has a concave portion at the corresponding position. On the other hand, when the guide 51b is a concave portion, the medium holder 10 has a convex portion at the corresponding position. The shape of the convex portion or the concave portion is not limited to that illustrated in FIGS. 10A and 10B, and any shape may be used as long as it can be easily fitted.
In the aspect of FIGS. 10A and 10B in which the guide 51b is provided, the positional accuracy is maintained by fitting the convex portion and the concave portion. In addition, when a work in which the medium holder 10 is aligned to the guide 51a, an operator can confirm that the medium holder 10 is appropriately fitted to the guide 51a by the feeling at the time of fitting. Thus, the work load of an operator can be reduced.
Guides 51c illustrated in FIG. 11A are magnetic bodies or magnets disposed on the conveyance surface of the conveyor belt 50. As illustrated in FIG. 11B, the medium holder 10 corresponding to the guides 51c has magnets or magnetic bodies (reference sign 14) that are attracted to the guides 51c on the surface that faces the conveyance surface. The combination of the guide 51c and a member included in the medium holder 10 may be a combination of magnets and magnetic bodies, or both may be magnets. The Curie temperature point indicating the demagnetization performance is higher than the thermal fixing temperature of the DTG print, so that the attraction performance is not affected even in the aspect in which the medium holder 10 includes the magnets. The shape of the magnetic body or the magnet is not limited to that illustrated in FIGS. 11A to 11C.
FIG. 11C illustrates an example in which the guide 51c is a magnet and the medium holder 10 also includes magnets 14. As illustrated in FIG. 11C, the guide 51c is formed of an S-pole magnet, and the medium holder 10 includes magnets 14 arranged in the order of the S-pole, an N-pole, and the S-pole, so that the attraction is induced by repulsion between the S-poles. Note that FIG. 11C is an example, and the combination of poles is not limited thereto.
In the aspect of FIGS. 11A to 11C in which the guide 51c is provided, the positional accuracy is maintained by the attraction by the magnetic force. In the operation of aligning the medium holder 10 with the guide 51a, the medium holder 10 is appropriately disposed by the attraction of the magnetic force, which leads to a reduction in the work load of an operator.
Guides 51d illustrated in FIG. 12A are plate-shaped members disposed on the conveyance surface of the conveyor belt 50. As illustrated in FIG. 12B, the medium holder 10 corresponding to the guides 51d has projections 15 that are engaged with the guides 51d on the surface facing the conveyance surface. The conveyance surface may be formed by an endless track formed by connecting plate-shaped members serving as the guides 51d in an endless annular shape. The plate-shaped member has hardness, which is advantageous in that the plate-shaped member is less likely to bend when the medium holder 10 is pressed against the plate-shaped member.
The projections 15 of the medium holder 10 are disposed on the front end and the rear end as illustrated in FIG. 12B, thus preventing deviation after positioning. On the other hand, when the interval between the plate-shaped members as the guide 51d is small enough to fit with and fix the projection 15, the projection 15 may be disposed only on the leading end of the medium holder 10 in the conveyance direction. In the latter case, the sum of the length of the plate-shaped member in the sub-scanning direction and the arrangement interval is preferably an integer multiple of the line feed amount p.
In the aspect including the guide 51d illustrated in FIGS. 12A to 12C, the positional accuracy is maintained by engaging the projection 15 with the lateral surface of the plate-shaped member in the thickness direction. In the operation of aligning the medium holder 10 with the guide 51d, the medium holder 10 is appropriately disposed by the attraction of the magnetic force, which leads to a reduction in the work load of an operator.
Next, a description is given of a mechanism that detects that the medium holder 10 is set on the conveyor belt 50 and that starts printing based on the detection result.
FIG. 13 is a diagram illustrating an example of the printing apparatus 100 including a leading end detector 68 that detects the leading end of the medium holder 10 on the back side of the printing apparatus 100. The continuous printing mode can be controlled to be executed in response to the detection by the leading end detector 68. FIG. 13 illustrates an aspect in which an optical sensor is provided as the leading end detector 68. However, the leading end detector 68 is not limited to the optical sensor, and may be a mechanical sensor or an electrical sensor.
FIG. 14 is a diagram illustrating an example in which a contact detector 69 is disposed on the conveyance surface of the conveyor belt 50. The contact detector 69 may be disposed at the same position as a guide and may have a function as a guide 51e. The contact detector 69 may be an electrical sensor. The print timing is adjusted and/or the continuous print mode is selected according to the detection result by the contact detector 69, and the continuous print mode can be controlled to be executed.
The contact detector 69 detects the installation of the medium holder 10 on the conveyance surface, and the direction in which the medium holder 10 is inserted is determined according to the detection result. Whether printing can start is automatically determined, so that the manual input of setting via the operation panel can be omitted.
Using the contact detector 69 as the guide 51e allows accurate determination of the time required for the medium holder 10 to be conveyed to the printing start position. For example, when it is determined that the interval between the preceding medium holder 10a and the subsequent medium holder 10b is sufficiently large and there is a sufficient time before the start of printing on a medium held by the subsequent medium holder 10b, control can be executed to perform maintenance operation during that time.
A description is given below of an example of performing pre-processing in the printing apparatus 100 according to the present embodiment. In inkjet printing, pretreatment liquid may be applied to a medium in advance to form less bleeding and more robust images. FIG. 15 is a diagram illustrating an example of the printing apparatus 100 including a head 30 that discharges pretreatment liquid 33 in addition to a head 30 that discharges white ink 31 and a head 30 that discharges color inks 32.
The heads 30 are arranged to discharge the pretreatment liquid 33, the white ink 31, and the color inks 32 in this order onto a medium M. Thus, the printing apparatus 100 can sequentially perform the printing of the pretreatment liquid 33, the printing of the white ink 31, and the printing of the color inks 32 in accordance with the conveyance of the medium 10. The arrangement interval of the heads 30 in the sub-scanning direction is preferably an integer multiple of the line feed amount p.
As a unit for applying the pretreatment liquid 33 to the medium M, a unit other than the head 30 can also be applied. Examples of the unit for applying the pretreatment liquid 33 include a sprayer, an application roller, and a brush.
FIG. 16 is a flowchart of an example of a procedure of determination of the front operation mode and the continuous printing mode. The start of the printing preparation corresponds to the start of an operation of setting the medium holder 10 (denoted as a "tray" in FIG. 16) on the conveyance surface of the conveyor belt 50.
First, it is determined whether the rear cover 12 is attached to the printing apparatus 100 (in step S01). When the rear cover 12 is not attached to the printing apparatus 100, it is determined whether the rear operation panel 41 disposed on the back side of the printing apparatus 100 is enabled (in step S02). When the rear operation panel 41 is enabled, it is determined whether the medium holder (tray) 10 is inserted from the back side and set (in step S03). When the medium holder (tray) 10 is set on the back side, printing in the continuous printing mode is started.
When the rear cover 12 is attached to the printing apparatus 100 in step S01, it is determined whether the medium holder (tray) 10 is inserted from the front side and set (in step S05). When the rear operation panel 41 is not enabled in step S02, the front operation panel 40 is used (in step S04), and it is determined whether the medium holder (tray) 10 is inserted from the front side and set (in step S05). When the medium holder (tray) 10 is set on the front side, printing in the front operation mode is started.
In step S03, when the medium holder (tray) 10 is inserted from the front side and set, a tray-insertion-opening error occurs, and printing is not performed. Similarly, in step S05, when the medium holder (tray) 10 is inserted from the back side and set, the tray-insertion-opening error occurs, and printing is not performed.
The printing preparation is performed based on a procedure illustrated in the flowchart of FIG. 16, so that an appropriate printing mode is selected. Thus, the occurrence of an error in the insertion direction of the medium holder 10 or an accident can be prevented.
A description is given of an example of the outline of a controller 500 of the printing apparatus 100 according to the present embodiment with reference to the block diagram illustrated in FIG. 17.
The controller 500 includes a main controller 500A including a central processing unit (CPU) 501, a read-only memory (ROM) 502, a random-access memory (RAM) 503, and a nonvolatile random-access memory (NVRAM) 504. The CPU 501 controls the entire system of the printing apparatus 100 according to the present embodiment. The ROM 502 stores programs executed by the CPU 501 and other fixed data. The RAM 503 temporarily stores, for example, image data. The NVRAM 504 stores various kinds of data such as a program and holds various kinds of data even while the power of the printing apparatus 100 is shut off.
The controller 500 includes a host interface (I/F) 506 for data transmission with a host device (information processing device) 600 such as a personal computer (PC), a print controller 511 for controlling the head 30, a main scanning driver 512, a sub-scanning driver 513 for driving the conveyor motor 16 of the conveyor, an analyzer 515 for analyzing inputs from tray sensors (e.g., the leading end detector 68 and the contact detector 69), and an input/output (I/O) 507 for various sensors and actuators (e.g., the unevenness detector 67).
The print controller 511 generates print data, generates a drive waveform for controlling the driving of the head 30, and transmits a head control signal for selecting a desired drive signal from the drive waveform and the print data. As a result, ink corresponding to the print data is discharged from the nozzles of the head 30.
The controller 500 controls the movement of the carriage 20 by controlling the driving of the main scanning motor via the main scanning driver 512. The controller 500 also controls the driving of the conveyor motor 16 via the sub-scanning driver 513 to control the conveyance of the medium holder 10.
The controller 500 further includes a maintenance controller 518 that controls the maintenance unit 23 that maintains the head 30.
The DTG printer has been described as an example of an embodiment of the present disclosure. However, the medium on which printing can be performed by the printing apparatus 100 according to the present embodiment is not limited to a fabric such as clothes, and a medium made of another material can be selected as long as liquid can be attached to the medium.
The printing apparatus according to the present embodiment can enhance productivity without increasing cost and installation space, and can be flexibly operated. For example, in a small-scale business or in small-lot production, the front operation mode can be executed and used in the same manner as a DTG printer according to a comparative example. On the other hand, when the scale is enlarged or the production demand is increased, the continuous printing mode is executed, and a large amount of printing can be efficiently performed without increasing the number of apparatuses.
A description is given below of some aspects according to the present disclosure.

First Aspect

A printing apparatus (e.g., the printing apparatus 100) includes a head (e.g., the head 30), a carriage (e.g., the carriage 20), and a conveyor (e.g., the conveyor belt 50). The head discharges liquid on a medium held by a medium holder (e.g., the medium holder 10). The carriage mounts the head and moves back and forth in a main scanning direction. The conveyor conveys the medium holder in a sub-scanning direction in response to the scanning of the head. The medium holder is attachable to and detachable from the conveyor in a state of holding the medium. The conveyor is a conveyor that can be driven to rotate in forward and reverse directions. The printing apparatus can perform a front operation mode and a continuous printing mode. In the front operation mode, a single medium holder is inserted from the front side of the printing apparatus, and the medium holder is moved back and forth by the conveyor. In the continuous printing mode, a plurality of medium holders are sequentially inserted from the back side of the printing apparatus, and the medium holders are moved in one direction by the conveyor.

Second Aspect

In the printing apparatus (e.g., the printing apparatus 100) according to the first aspect, when a line feed amount per line feed operation in which the conveyor (e.g., the conveyor belt 50) moves the medium holder (e.g., the medium holder 10) in the sub-scanning direction in response to scanning of the head (e.g., the head 30) is p, in the continuous printing mode, a conveyance amount W by which the subsequent medium holder is conveyed in the sub-scanning direction from the last scanning of a medium held by the preceding medium holder by the head to the first scanning of another medium held by the subsequent medium holder satisfies a relation of W = p × n, where n is an integer of one or more.

Third Aspect

The printing apparatus (e.g., the printing apparatus 100) according to the first or second aspect further includes a rear cover (e.g., the rear cover 12) disposed on the back side of the printing apparatus and is attachable to and detachable from a body of the printing apparatus. When the rear cover is attached to the body of the printing apparatus, only the front operation mode is performed.

Fourth Aspect

In the printing apparatus (e.g., the printing apparatus 100) according to any one of the first to third aspects, the conveyor (e.g., the conveyor belt 50) includes a guide (e.g., the guide 51) that positions the medium holder (e.g., the medium holder 10) on a conveyance surface of the conveyor. A plurality of guides (e.g., the guide 51) are arranged on the conveyance surface of the conveyor. An arrangement interval of the plurality of guides in the sub-scanning direction is n times (n is an integer of one or more) of a line feed amount per line feed operation in which the conveyor moves the medium holder in the sub-scanning direction in response to the scanning of the head (e.g., the head 30).

Fifth Aspect

In the printing apparatus (e.g., the printing apparatus 100) according to the fourth aspect, the guide (e.g., the guide 51) has a visible pattern formed on the conveyance surface.

Sixth Aspect

In the printing apparatus (e.g., the printing apparatus 100) according to the fourth aspect, the guide (e.g., the guide 51) is a convex portion or a concave portion formed on the conveyance surface, and the medium holder (e.g., the medium holder 10) has a concave portion or a convex portion that is fitted to the guide on a surface facing the conveyance surface.

Seventh Aspect

In the printing apparatus (e.g., the printing apparatus 100) according to the fourth aspect, the guide (e.g., the guide 51) is a magnetic body or a magnet disposed on the conveyance surface, and the medium holder (e.g., the medium holder 10) has a magnet or a magnetic body that is attracted to the guide on a surface facing the conveyance surface.

Eighth Aspect

In the printing apparatus (e.g., the printing apparatus 100) according to the fourth aspect, the guide (e.g., the guide 51) is a plate-shaped member disposed on the conveyance surface, and the medium holder (e.g., the medium holder 10) includes a projection that is engaged with the guide on a surface facing the conveyance surface.

Ninth Aspect

In the printing apparatus (e.g., the printing apparatus 100) according to the fourth aspect, the guide (e.g., the guide 51) is a contact detector (e.g., the contact detector 69) disposed on the conveyance surface. An adjustment of the printing timing and/or a selection of the continuous printing mode is performed according to a detection result by the contact detector.

Tenth Aspect

The printing apparatus (e.g., the printing apparatus 100) according to any one of the first to ninth aspects further includes a leading end detector (e.g., the leading end detector 68) that detects a leading end of the medium holder (e.g., the medium holder 10) on the back side of the printing apparatus. The continuous printing mode is performed in response to detection by the leading end detector.

Eleventh Aspect

The printing apparatus (e.g., the printing apparatus 100) according to any one of the first to tenth aspects further includes a front operation panel (e.g., the front operation panel 40) disposed on the front side of the printing apparatus and/or a rear operation panel (e.g., the rear operation panel 41) disposed on the back side of the printing apparatus. The printing apparatus performs the front operation mode in response to an input from the front operation panel and performs the continuous printing mode in response to an input from the rear operation panel.

Twelfth Aspect

A printing system includes the printing apparatus (e.g., the printing apparatus 100) according to any one of the first to eleventh aspects and a conveyor drying apparatus that dries the medium printed by the printing apparatus.
Any one of the above-described operations may be performed in various other ways, for example, in an order different from the one described above.

Claims

A printing apparatus (100) comprising:
a head (30) to discharge liquid on a medium held by a medium holder (10);

a carriage (20) mounted with the head (30) to move back and forth in a main scanning direction;

a conveyor (50) to rotate in forward and reverse directions to convey the medium holder (10) in a sub-scanning direction in response to scanning of the head (30); and

a controller (500) to perform a front operation mode and a continuous printing mode,

wherein the medium holder (10) is attachable to and detachable from the conveyor (50) in a state the medium is held on the medium holder (10),

wherein, in the front operation mode, the controller (500) causes the conveyor (50) to move a single medium holder (10) inserted from a front side of the printing apparatus (100) back and forth, and

wherein, in the continuous printing mode, the controller (500) causes the conveyor (50) to move a plurality of medium holders sequentially inserted from a back side of the printing apparatus (100) in one direction.
The printing apparatus (100) according to claim 1,
wherein in the continuous printing mode, the plurality of medium holders includes a preceding medium holder and a subsequent medium holder subsequent to the preceding medium holder,

wherein, when a line feed amount per line feed operation in which the conveyor (50) moves the medium holder (10) in the sub-scanning direction in response to the scanning of the head (30) is p, in the continuous printing mode, a conveyance amount W by which the subsequent medium holder (10) is conveyed in the sub-scanning direction from last scanning of a medium held on the preceding medium holder by the head (30) to first scanning of another medium held on the subsequent medium holder by the head (30) satisfies a relation of W = p × n, where n is an integer of one or more.
The printing apparatus (100) according to claim 1 or 2, further comprising a rear cover (12) disposed on the back side of the printing apparatus (100), the rear cover (12) attachable to and detachable from a body of the printing apparatus (100),
wherein, when the rear cover (12) is attached to the body of the printing apparatus (100), the controller (500) performs only the front operation mode.
The printing apparatus (100) according to any one of claims 1 to 3, wherein the conveyor (50) includes a guide (51) to position the medium holder (10) on a conveyance surface of the conveyor (50),
wherein a plurality of guides including the guide (51) are arranged on the conveyance surface of the conveyor (50), and

wherein an arrangement interval of the plurality of guides in the sub-scanning direction is n times, where n is an integer of one or more, of a line feed amount per line feed operation in which the conveyor (50) moves the medium holder (10) in the sub-scanning direction in response to the scanning of the head (30).
The printing apparatus (100) according to claim 4,
wherein the guide (51) has a visible pattern on the conveyance surface of the conveyor (50).
The printing apparatus (100) according to claim 4,
wherein the guide (51) is a convex portion or a concave portion on the conveyance surface of the conveyor (50), and

wherein the medium holder (10) has a concave portion or a convex portion to fit with the guide (51) on a surface facing the conveyance surface of the conveyor (50).
The printing apparatus (100) according to claim 4,
wherein the guide (51) is a magnetic body or a magnet on the conveyance surface of the conveyor (50), and

wherein the medium holder (10) has a magnet or a magnetic body to be attracted to the guide (51) on a surface facing the conveyance surface of the conveyor (50).
The printing apparatus (100) according to claim 4,
wherein the guide (51) is a plate on the conveyance surface of the conveyor (50), and

wherein the medium holder (10) includes a projection to be engaged with the guide (51) on a surface facing the conveyance surface of the conveyor (50).
The printing apparatus (100) according to claim 4,
wherein the guide (51) is a contact detector (69) disposed on the conveyance surface of the conveyor (50), and

wherein the controller (500) performs at least one of an adjustment of a printing timing and a selection of the continuous printing mode according to a detection result by the contact detector (69).
The printing apparatus (100) according to any one of claims 1 to 9, further comprising a leading end detector (68) to detect a leading end of the medium holder (10) on the back side of the printing apparatus (100),
wherein the controller (500) performs the continuous printing mode in response to detection of the leading end detector (68) by the leading end detector (68).
The printing apparatus (100) according to any one of claims 1 to 10, further comprising at least one of a front operation panel (40) on the front side of the printing apparatus (100) and a rear operation panel (41) on the back side of the printing apparatus (100),
wherein the controller (500) performs the front operation mode in response to an input from the front operation panel (40) and performs the continuous printing mode in response to an input from the rear operation panel (41).
A printing system, comprising:
the printing apparatus (100) according to any one of claims 1 to 11 to print the medium; and

a conveyor drying apparatus to dry the medium printed by the printing apparatus (100).