Patent Application
20190039378
This application claims the benefit of priority to Japanese Patent Application No. 2017-150156 filed on Aug. 2, 2017 and Japanese Patent Application No. 2018-107668 filed on Jun. 5, 2018. The entire contents of these applications are hereby incorporated herein by reference.
The present invention relates to inkjet printers.
An inkjet printer known in the related art includes an ink head provided at its nozzle surface with a plurality of nozzles and is configured to effect predetermined printing on a recording medium in an inkjet mode. Such an inkjet printer is provided with a cap unit in order to maintain discharge performance of the nozzles at a suitable level. The cap unit includes a cap to cover the nozzle surface when no printing is being effected.
The cap unit covers the nozzle surface with the cap so as to define an enclosed space between the nozzle surface and the cap. The cap unit includes a suction pump connected to the cap. The suction pump is driven, with the enclosed space defined, so that ink remaining in the nozzles is forcedly discharged to the cap. This prevents ink from solidifying in the nozzles and thus precludes clogging of the nozzles. A suction operation to discharge ink remaining in the ink head is generally referred to as “main suction”.
After main suction, the suction pump is driven again, with the enclosed space exposed to atmospheric pressure, in order to discharge ink remaining in the cap unit, such as ink remaining in the cap or suction path. This makes it possible to discharge ink remaining in the cap unit without applying any excessive negative pressure to the ink head. A suction operation to discharge ink in the cap unit is generally referred to as “idle suction”. A combination of main suction and idle suction may be referred to as “suction cleaning”. Japanese Patent No. 3981502, for example, discloses a technique involving performing idle suction, with the cap detached from the nozzle surface, or performing idle suction after the enclosed space is exposed to atmospheric pressure through an atmospheric pressure exposure element, with the cap in intimate contact with the nozzle surface.
To meet recent demands for printers that are able to effect colorful, high-resolution printing, the number of types of ink used in each printer and the number of ink heads of each printer tend to increase. A cap unit, such as one described above, is usually provided for each ink head. Thus, an increase in the number of ink heads unfortunately increases the number of components of ink supply paths leading to the ink heads. In addition, the number of components of the cap unit also increases, resulting in an increase in size of a printer.
When a cap is detached from a nozzle surface so as to perform idle suction described above, ink discharged toward the cap may keep adhering to the nozzle surface. The ink adhering to the nozzle surface is naturally sucked into a nozzle owing to the negative pressure of an ink supply path. This may make it impossible to prevent nozzle clogging. When two or more types of ink are supplied to a single ink head, ink adhering to the nozzle surface becomes ink of mixed colors that unfavorably contaminates the nozzle. To solve such a problem, an atmospheric pressure exposure element is desirably provided for each cap. An inexpensive atmospheric pressure exposure element, however, is likely to take up space, making it difficult to design a layout of the atmospheric pressure exposure element.
Accordingly, preferred embodiments of the present invention provide inkjet printers each including a cap unit including an atmospheric pressure exposure element without any excessive increase in overall size of the inkjet printer and that is readily adaptable to an increase in the number of ink heads.
An inkjet printer according to a preferred embodiment of the present invention includes a plurality of ink heads, an ink head conveyor, a plurality of caps, a cap conveyor, a plurality of suction devices, a plurality of cap valves, a plurality of first passages, and a plurality of second passages. The ink head conveyor moves the ink heads in a main scanning direction. The main scanning direction includes a first direction and a second direction opposite to the first direction. The caps are each detachably attachable to an associated one of the ink heads. The cap conveyor supports the caps. The cap conveyor moves the caps between a cap attaching position at which the caps are attached to the ink heads and a retracted position at which the caps are detached from the ink heads. The suction devices are each provided for an associated one of the caps. The first passages each connect an associated one of the caps to an associated one of the cap valves. The second passages each connect an associated one of the caps to an associated one of the suction devices. The cap conveyor includes a base, a movable table, a support wall, and a table urging member. The movable table supports the caps. The support wall stands vertically or substantially vertically on the base. The support wall supports the movable table such that the movable table is movable between the cap attaching position and the retracted position. The table urging member urges the movable table to the retracted position. The movable table includes a table wall extending upward from an end of the movable table facing in the first direction. The first direction is a direction extending to the cap attaching position in the main scanning direction. The cap valves are disposed on a surface of the table wall facing in the first direction.
In this preferred embodiment, the movable table of the cap conveyor includes the table wall on which the cap valves functioning as atmospheric pressure exposure elements are disposed such that the cap valves are located above the movable table supporting the caps and do not interfere with movement of the ink heads. Thus, if the ink heads and the cap valves are increased in number, this preferred embodiment would make it possible to dispose the cap valves without increasing the area occupied by the cap valves in a plan view. Consequently, this preferred embodiment provides a cap unit including the cap valves without entailing an increase in overall size of the inkjet printer.
Various preferred embodiments of the present invention provide inkjet printers each including a cap unit including an atmospheric pressure exposure element without any excessive increase in overall size of the inkjet printer and that is readily adaptable to an increase in the number of ink heads.
The above and other elements, features, steps, characteristics and advantages of the present invention will become more apparent from the following detailed description of the preferred embodiments with reference to the attached drawings.
Inkjet printers according to preferred embodiments of the present invention will be described below with reference to the drawings. The preferred embodiments described below are naturally not intended to limit the present invention in any way. Components or elements having the same functions are identified by the same reference signs, and description thereof will be omitted or simplified if deemed redundant.
As illustrated in
In the present preferred embodiment, the recording medium 8 is rolled recording paper or “rolled paper”. The recording medium 8, however, is not limited to rolled recording paper. The recording medium 8 may be any medium other than paper (e.g., plain paper and inkjet printing paper). Examples of the recording medium 8 include: a resin sheet or film made of polyvinyl chloride or polyester, for example; a plate material; and a fabric, such as a woven fabric or a nonwoven fabric. The recording medium 8 may be any other suitable medium. In the present preferred embodiment, a material for the recording medium 8 is not limited to any particular material.
The printer 1 includes the platen 6 on which the recording medium 8 is to be placed. The platen 6 is provided with cylindrical grit rollers 16 that define and function as components of a recording medium conveyor. The grit rollers 16 are embedded in the platen 6, with the upper surfaces of the grit rollers 16 exposed. The grit rollers 16 are driven by a feed motor (not illustrated).
The guide rail 10 is disposed above the platen 6. The guide rail 10 is disposed in parallel or substantially in parallel with the platen 6. The guide rail 10 extends in the main scanning direction Y. The printer 1 further includes a plurality of pinch rollers 18 disposed below the guide rail 10. The pinch rollers 18 are located at equal or substantially equal intervals. The pinch rollers 18 each face an associated one of the grit rollers 16. The position of each pinch roller 18 in the up-down direction Z is adjustable in accordance with the thickness of the recording medium 8. The recording medium 8 is sandwiched between each pinch roller 18 and the associated grit roller 16. Rotating the grit rollers 16 by the feed motor enables the grit rollers 16 and the pinch rollers 18 to convey the recording medium 8 in the sub-scanning direction X, with the recording medium 8 sandwiched between each grit roller 16 and the associated pinch roller 18. The grit rollers 16, the pinch rollers 18, and the feed motor are an example of the recording medium conveyor to move the recording medium 8 and the ink head unit 30 (which will be described below) relative to each other in the sub-scanning direction X.
The printer 1 includes the ink head unit 30. As illustrated in
As illustrated in
As illustrated in
The printer 1 includes an ink feeder (not illustrated). The ink feeder feeds ink from ink tanks 21 to the nozzles arranged in the ink heads 32. Each ink tank 21 stores ink. The ink stored in the ink tanks 21 is fed to the ink heads 32 through ink passages (not illustrated). Each ink passage is not limited to any particular type or material. In one example, each ink passage is a flexible silicon tube. In the present preferred embodiment, the number of ink tanks 21 is equal to the number of ink heads 32. The ink tanks 21 according to the present preferred embodiment are each connected to two of the ink heads 32. A single passage connected to each ink tank 21 is split into two passages at some point. Ink stored in two of the ink tanks 21 is fed to four different nozzle rows provided in an associated pair of the ink heads 32. Thus, two different types of ink are fed to each ink head 32 from the associated two ink tanks 21. The ink tanks 21 normally store ink of different colors. Alternatively, some of the ink tanks 21 may store ink of the same color. The ink stored in each ink tank 21 is not limited to any particular color. In one example, the ink stored in each ink tank 21 may be any one of: process color ink, such as cyan ink, magenta ink, yellow ink, black ink, light cyan ink, light magenta ink, and light black ink; and spot color ink, such as white ink, metallic ink, and clear ink.
A feed pump (not illustrated) is provided at a location somewhere along each ink passage connected to the associated ink tank 21. Each feed pump sends a fluid (e.g., ink) in the ink passage from the upstream side to the downstream side. Each feed pump is provided on a portion of the associated ink passage located upstream of the point where the ink passage is split into two passages. During operation, the feed pumps send ink from the ink tanks 21 to the ink heads 32. Each feed pump is not limited to any particular type. In one example, each feed pump is a tube pump. The tube pump internally includes an inner tube and a roller. The tube pump rotates the roller in a planetary manner while the roller crushes the inner tube, so that ink is sent in the direction of travel of the roller. The tube pump may send ink from the downstream side to the upstream side by rotating the roller in a planetary manner in a reverse direction.
A portion of the ink passage located between each ink tank 21 and the feed pump is provided with a pressure control valve (not illustrated). Each pressure control valve maintains the inside of the nozzles of the associated ink heads 32 at a negative pressure when no ink is being discharged. As used herein, the term “negative pressure” refers to a pressure lower than an external pressure (which is typically atmospheric pressure). Maintaining the inside of the ink heads 32 at a negative pressure prevents ink in the ink heads 32 from trickling down to the outside through the nozzles. Each pressure control valve maintains ink in the nozzles of the ink heads 32 at about −1 kPa. Each pressure control valve includes: a passage through which ink flows; and a valve operating mechanism to open and close the passage. The valve operating mechanism opens and closes in accordance with the fluid pressure in a region downstream of the valve operating mechanism. The valve operating mechanism receives the pressure of ink upstream of the valve operating mechanism, the pressure of ink downstream of the valve operating mechanism, a mechanical force that will close the valve operating mechanism, and a mechanical force that will open the valve operating mechanism. When the printer 1 is not in use, these pressures and forces keep their balance. In such a balanced state, the valve operating mechanism seals the passage. The pressure of ink in this state is the pressure of ink at rest, which is maintained at about −1 kPa. The mechanical force that will close or open the valve operating mechanism is, for example, a restoring force of a spring. Activating a suction pump 46 sucks out ink from a region downstream of the valve operating mechanism. This reduces the pressure of ink on the downstream side so as to disturb the balance, causing the valve operating mechanism to open. Once the valve operating mechanism opens, the passage is opened so as to feed ink in the downstream direction. With such a mechanism, each pressure control valve maintains ink at a negative pressure when the printer 1 is not in use, and sends ink to the associated ink heads 32 when the printer 1 is in use.
A damper (not illustrated) is provided at a location somewhere along each ink passage connected to the associated ink tank 21. The dampers are provided immediately upstream of the ink heads 32. The dampers store ink to be sent to the ink heads so as to reduce variations in ink pressure and stabilize discharge operation of the ink heads 32. Each of the dampers according to the present preferred embodiment includes: a storage chamber to store ink; and a sensor to detect the pressure of ink stored in the storage chamber. The pressure of ink stored in the storage chamber is equal or substantially equal to the pressure inside the nozzles. The sensor is an example of a detector to detect the pressure inside the nozzles. During printing, each damper keeps the pressure of ink stored in the storage chamber within a predetermined range so as to reduce variations in ink pressure. In one example, the sensor of each damper is a photosensor for position detection. One of wall surfaces of the storage chamber of each damper is a film that expands and contracts so as to deform in a concavo-convex manner in response to the pressure of ink stored in the storage chamber. The sensor of each damper detects the pressure of ink inside the storage chamber in accordance with the concavo-convex deformation of the film. When the film expands beyond a first reference position, the sensor transmits an upper limit signal to the controller 100. When the film contracts to a second reference position, the sensor transmits a lower limit signal to the controller 100. Upon receiving the upper limit signal or the lower limit signal, the controller 100 rotates the feed pump in a forward direction or a reverse direction so as to start or stop feeding ink. The pressure detector of each damper may naturally be any detector other than the sensor described above.
As illustrated in
As illustrated in
Each cap 42 is detachably attachable to the associated ink head 32 so as to cover the nozzle surface of the associated ink head 32. As used herein, the phrase “to cover the nozzle surface” refers to not only covering an entirety of the nozzle surface but also covering at least the nozzle rows of the nozzle surface. The caps 42 are disposed in the movable table 41. The caps 42 are each fitted into an associated one of openings 41a provided in the movable table 41. The movable table 41 is made of a single steel plate. The openings 41a are provided by punching. The openings 41a of the movable table 41 are provided at predetermined locations such that the arrangement of the caps 42 corresponds to the arrangement of the ink heads 32 disposed in the head plate 36. Specifically, four of the eight caps 42 are arranged at equal or substantially equal intervals in the main scanning direction Y and disposed in a relatively forward portion of the movable table 41. The other four of the eight caps 42 are arranged at equal or substantially equal intervals in the main scanning direction Y and disposed in a relatively rearward portion of the movable table 41. Each of the relatively forwardly disposed caps 42 pairs up with an adjacent one of the relatively rearwardly disposed caps 42. An end of the movable table 41 facing in the first direction Y1 includes a table wall 41b. The table wall 41b is provided by sheet metal processing. In one example, the table wall 41b is provided by bending, in the upward direction U, the right end of the steel plate that defines the movable table 41. An end of the movable table 41 facing in the first direction Y1 and located on the rear side Rr includes a movement stopper 41c. The movement stopper 41c comes into engagement with the engagement portion 31A (see
As illustrated in
The body case 43a includes a bottom and a side wall. The body case 43a has a box shape having an upwardly facing opening. The side wall of the body case 43a has a shape conforming to the nozzle surface of the associated ink head 32. In one example, the side wall of the body case 43a has an oval shape in the plan view. The side wall of the body case 43a is structured such that the nozzle surface of the associated ink head 32 is fitted into the body case 43a. The bottom of the body case 43a is provided with a protrusive hole 43b protruding upward, and a through hole 43c. The lower ends of the protrusive hole 43b and the through hole 43c are each provided with a protrusion protruded in the downward direction D from the bottom of the body case 43a such that the protrusive hole 43b and the through hole 43c are connectable to the associated passage 44. The lower ends of the protrusive hole 43b and the through hole 43c are protruded in the downward direction D from the movable table 41. The protrusive hole 43b is connected with an associated one of opening passages 44a (which will be described below). The upper end of the protrusive hole 43b is located at the same height as the upper surface of the absorber 43h or above the upper surface of the absorber 43h. The upper end of the protrusive hole 43b is located below the upper end of the lip 43d. The lower end of the through hole 43c is connected with an associated one of suction passages 44b (which will be described below). The protrusive hole 43b defines and functions as a portion of a first passage. The through hole 43c defines and functions as a portion of a second passage.
The lip 43d is held in the opening of the body case 43a. The lip 43d includes a bottom and a side wall. The lip 43d is provided with an opening facing upward. The upper end of the side wall of the lip 43d decreases in thickness (or width) as it extends upward. The lip 43d is made of an elastically deformable material. In one example, the lip 43d is made of rubber. The lip 43d is provided in the body case 43a such that the lip 43d elastically comes into contact with the nozzle surface of the associated ink head 32. Bringing the lip 43d into contact with the nozzle surface of the associated ink head 32 defines the enclosed space S. The bottom of the lip 43d is provided with a through hole 43g and a through hole 43f. The protrusive hole 43b passes through the through hole 43g. The through hole 43f is in communication with the through hole 43c and the suction passage 44b. The upper surface of the bottom of the lip 43d is provided with a groove 43e recessed in the downward direction D. The groove 43e is in communication with the through hole 43f. The groove 43e extends across the entire or substantially the entire surface of the bottom of the lip 43d.
The absorber 43h is held in the opening of the lip 43d. The absorber 43h is made of an air-permeable porous material capable of absorbing ink. Examples of the porous material include a sponge, a woven fabric, and a nonwoven fabric. The absorber 43h includes a through hole 43i. The protrusive hole 43b passes through the through hole 43i. The upper surface of the absorber 43h is located below the upper end of the lip 43d. The upper surface of the absorber 43h is located at the same height as the upper end of the protrusive hole 43b or below the upper end of the protrusive hole 43b.
As illustrated in
Each cap valve 45 is provided at a location somewhere along the associated opening passage 44a or on an end of the associated opening passage 44a. Each cap valve 45 performs switching between an open state where the inside of the associated opening passage 44a is in communication with the outside of the associated opening passage 44a and a closed state where the inside of the associated opening passage 44a is out of communication with the outside of the associated opening passage 44a. Each cap valve 45 is not limited to any particular configuration or operating mechanism. Each cap valve 45 may be a “control valve” that switches between the open state and the closed state using at least one of water (i.e., vapor), air, electricity, magnetism, and hydraulic pressure to be supplied separately. Each cap valve 45 may be a valve that switches between the open state and the closed state by a mechanical operation. Each cap valve 45 according to the present preferred embodiment is, for example, a piston valve openable and closable by a small actuating force. The cap unit 40 includes a plurality of composite cap valves 47. Each of the composite cap valves 47 includes two of the cap valves 45 integral with each other. One of the two cap valves 45 included in each composite cap valve 47 may hereinafter be referred to as a “first cap valve 45”. The other one of the two cap valves 45 included in each composite cap valve 47 may hereinafter be referred to as a “second cap valve 45”. The number of composite cap valves 47 included in the cap unit 40 is four, for example.
A large portion of each of the piston valve elements 45f and 47f is held in the composite valve case 47a. The piston valve elements 45f and 47f are movable in the up-down direction Z inside the composite valve case 47a. When the piston valve elements 45f and 47f are located at closing positions (i.e., lowermost positions), the piston valve elements 45f and 47f respectively close the inner passages 45b and 47b (see
The piston valve element 45f includes a rod 45h (which may hereinafter be referred to as a “first rod 45h”) protruding in the main scanning direction Y. The piston valve element 47f includes a rod 47h (which may hereinafter be referred to as a “second rod 47h”) protruding in the main scanning direction Y. A first end of the rod 45h is secured to the piston valve element 45f. A first end of the rod 47h is secured to the piston valve element 47f. The rod 45h is secured to the lower portion of the piston valve element 45f. The rod 47h is secured to the lower portion of the piston valve element 47f. A second end of the rod 45h extends out of the composite valve case 47a through the opening 45e. A second end of the rod 47h extends out of the composite valve case 47a through the opening 47e. The second end of the rod 45h includes an inclined surface 45i extending obliquely upward to the right such that the second end of the rod 45h tapers to its upper tip. The second end of the rod 47h includes an inclined surface 47i extending obliquely upward to the right such that the second end of the rod 47h tapers to its upper tip. At normal times, the piston valve element 45f is urged to the closing position by the spring 45j, so that the rod 45h of the piston valve element 45f passes through a lower region of the opening 45e. At normal times, the piston valve element 47f is urged to the closing position by the spring 47j, so that the rod 47h of the piston valve element 47f passes through a lower region of the opening 47e. Lifting the rod 45h in the upward direction U moves the rod 45h in the upward direction U through the opening 45e. Lifting the rod 47h in the upward direction U moves the rod 47h in the upward direction U through the opening 47e. In accordance with the movement of the rod 45h in the upward direction U, the piston valve element 45f moves in the upward direction U against the elastic force of the spring 45j. In accordance with the movement of the rod 47h in the upward direction U, the piston valve element 47f moves in the upward direction U against the elastic force of the spring 47j. The movement of the piston valve elements 45f and 47f in the upward direction U opens the composite cap valve 47. The rods 45h and 47h are liftable independently or in conjunction with each other. Thus, the two cap valves 45 of each composite cap valve 47 are openable and closable independently or in conjunction with each other.
The composite valve case 47a may be divided into: a first cap valve area A including the inner passage 45b, the piston valve element 45f, the rod 45h, and the spring 45j; and a second cap valve area B including the inner passage 47b, the piston valve element 47f, the rod 47h, and the spring 47j. The first cap valve area A defines and functions as one of the two cap valves 45 of the composite cap valve 47. The second cap valve area B defines and functions as the other one of the two cap valves 45 of the composite cap valve 47. The composite valve case 47a includes a through hole 47k between the first cap valve area A and the second cap valve area B. The through hole 47k passes through the composite valve case 47a in the up-down direction Z.
As illustrated in
Each opening passage 44a connected to the associated cap 42 extends in the rightward direction R (i.e., the first direction Y1) from a location below the movable table 41. The opening passages 44a extending from an associated pair of the caps are connected to the inlets 45c and 47c of the associated composite cap valve 47. As illustrated in
Each suction pump 46 includes an inlet on the upstream side, and an outlet on the downstream side. Each suction pump 46 sucks, through the inlet, a fluid (e.g., gas such as air or liquid such as ink) in a portion of the associated suction passage 44b connected to the upstream inlet of the suction pump 46, and sends the fluid to the outlet. This reduces the pressure inside the portion of the associated suction passage 44b connected to the upstream inlet of the suction pump 46. Thus, with each cap 42 attached to the associated ink head 32, driving each suction pump 46 reduces the pressure inside the associated enclosed space S and sucks the fluid inside the associated enclosed space S. Each suction pump 46 sends the sucked fluid to a downstream portion of the associated suction passage 44b. Each suction pump 46 is not limited to any particular configuration. In one example, each suction pump 46 is a cylinder type suction pump. Each suction pump 46 is an example of a suction device. The waste liquid bottle 49 is a container to contain liquid (such as ink) discharged to the downstream side from each suction pump 46. The waste liquid bottle 49 may be attachable to and detachable from the lower portion of the side cover 15, for example.
As illustrated in
The base 51 defines and functions as a base for an entirety of the conveyor 50. The right side wall 52 stands vertically or substantially vertically in the up-down direction Z on an end of the base 51 facing in the first direction Y1. The upper end of the right side wall 52 includes lifters 52A each extending obliquely downward to the left. In other words, each lifter 52A includes an inclined surface extending obliquely upward to the right. Each lifter 52A is a member to lift the rod 45h or 47h of the associated cap valve 45. Each lifter 52A is provided by sheet metal processing. In one example, each lifter 52A is provided by bending the upper end of the right side wall 52.
In the present preferred embodiment, each lifter 52A is disposed on a portion of the right side wall 52 that faces the rod 45h or 47h in the second direction Y2. Because the four composite cap valves 47 are disposed in a hound's tooth pattern, the rods 45h and 47h are also disposed in a hound's tooth pattern. Thus, the lifters 52A according to the present preferred embodiment are also disposed in a hound's tooth pattern. Specifically, the right side wall 52 includes a first right side wall 52d and a second right side wall 52u. With the composite cap valves 47 in the closed state, the first right side wall 52d is located below the rods 45h and 47h of the two composite cap valves 47 disposed on the relatively lower portion of the table wall 41b. With the composite cap valves 47 in the closed state, the second right side wall 52u is located above the rods 45h and 47h of the two composite cap valves 47 disposed on the relatively lower portion of the table wall 41b.
The first right side wall 52d is made of a sheet of steel connected to the base 51. The lifters 52A include first lifters 52A1. The first lifters 52A1 are provided on the upper end of the first right side wall 52d by sheet metal processing. Specifically, the first lifters 52A1 are provided by bending the upper end of the first right side wall 52d such that the first lifters 52A1 extend toward the composite cap valves 47 (i.e., substantially in the second direction Y2). Each first lifter 52A1 is provided on a portion of the first right side wall 52d that faces the rod 45h or 47h, but no lifter 52A1 is provided on a portion of the first right side wall 52d that does not face the rod 45h or 47h. Whether a portion of the first right side wall 52d faces the rod 45h or 47h does not necessarily have to be determined based on whether the portion of the first right side wall 52d faces the rod 45h or 47h in the main scanning direction Y in a strict sense. For example, suppose that distances are measured between each rod 45h or 47h and points on an imaginary line extending in the front-rear direction X on the first right side wall 52d (which may be the second side wall 52u) at a height at which the first right side wall 52d faces the rods 45h and 47h. In this case, the present preferred embodiment involves defining, in accordance with the distances measured, first points Q1 each located closest to the associated rod 45h or 47h and second points Q2 each located farthest away from the associated rod 45h or 47h. An intermediate point Qm is located between each first point Q1 and the associated second point Q2, for example in the center. Thus, a portion of the first right side wall 52d located closer to the first point Q1 relative to the intermediate point Qm may be determined as a “portion of the first right side wall 52d that faces the rod 45h or 47h”, and a portion of the first right side wall 52d located closer to the second point Q2 relative to the intermediate point Qm may be determined as a “portion of the first right side wall 52d that does not face the rod 45h or 47h”. Accordingly, the first right side wall 52d has a saw-toothed shape having projections and recesses arranged alternately in the plan view, with the first lifters 52A1 defining the projections.
The second right side wall 52u made of a sheet of steel is connected to the upper portion of the first right side wall 52d. A portion of the first right side wall 52d and a portion of the second right side wall 52u are flush or substantially flush with each other in the up-down direction Z. The lifters 52A include second lifters 52A2. The second lifters 52A2 are provided on the upper end of the second right side wall 52u by sheet metal processing. Specifically, the second lifters 52A2 are provided by bending the upper end of the second right side wall 52u such that the second lifters 52A2 extend toward the composite cap valves 47 (i.e., substantially in the second direction Y2). Each second lifter 52A2 is provided on a portion of the second right side wall 52u that faces the rod 45h or 47h, but no second lifter 52A2 is provided on a portion of the second right side wall 52u that does not face the rod 45h or 47h. A portion of the second right side wall 52u that faces the rod 45h or 47h and a portion of the second right side wall 52u that does not face the rod 45h or 47h may be determined in a manner similar to that used for the first right side wall 52d. Accordingly, the second right side wall 52u has a saw-toothed shape having projections and recesses arranged alternately in the plan view, with the second lifters 52A2 defining the projections.
As previously described, the rods 45h and 47h are arranged in a hound's tooth pattern. Thus, the first and second lifters 52A1 and 52A2 are also arranged in a hound's tooth pattern. In one example, the first and second lifters 52A1 and 52A2 are arranged such that each first lifter 52A1 is located between the second lifters 52A2 in the plan view. In the plan view, the rods 45h and 47h of the two composite cap valves 47 disposed on the relatively lower portion of the table wall 41b are each located between the second lifters 52A2 protruding from the right side wall 52.
The guide wall 53 stands vertically or substantially vertically on the base 51 and extends in the main scanning direction Y. The guide wall 53 includes: a guide wall 53a disposed on the front portion of the base 51; a guide wall 53b disposed on the front portion of the base 51; a guide wall 53c disposed on the rear portion of the base 51; and a guide wall 53d disposed on the rear portion of the base 51. The guide walls 53a and 53c face each other in the front-rear direction X on the base 51. The guide walls 53b and 53d face each other in the front-rear direction X on the base 51. The four guide walls 53a, 53b, 53c, and 53d are identical or substantially identical in shape. The four guide walls 53a, 53b, 53c, and 53d are provided with guide holes 54. As illustrated in
The spring 55 is connected to the upper surface of the base 51 and the lower surface of the movable table 41. The connection between the spring 55 and the movable table 41 is located obliquely above and rightward of the connection between the spring 55 and the base 51. In one example, a helical tension spring is usable as the spring 55. The spring 55 is connected, under predetermined tension, to the base 51 and the movable table 41. The spring 55 urges the movable table 41 downward to the left at all times.
The conveyor 50 moves the movable table 41 in conjunction with movement of the ink head unit 30. In other words, the conveyor 50 moves the cap unit 40 in conjunction with movement of the ink heads 32. The conveyor 50 is an example of a cap conveyor to move the cap unit 40 between a cap attaching position and a retracted position.
As illustrated in
Once the printer 1 has stopped printing, the ink head unit 30 is held in the side cover 15. After printing, the ink head unit 30 placed on the carriage 31 is moved along the guide rail 10 to the “cap attaching position” defined in the side cover 15. In the course of this movement, the engagement portion 31A (see
As illustrated in
Movement of the carriage 31 in the second direction Y2 toward a position leftward of the “valve opening position” or the “cap attaching position” causes the engagement portion 31A of the carriage 31 to stop applying a pressing force to the movement stopper 41c of the movable table 41 or reduce the pressing force applied to the movement stopper 41c. The movable table 41 is urged downward to the left by the spring 55. Thus, the movable table 41 is moved to the “retracted position” from the “valve opening position” or the “cap attaching position”.
The controller 100 is configured or programmed to comprehensively control operations of the components of the printer 1. The controller 100 is not limited to any particular configuration. In one example, the controller 100 is a microcomputer. The microcomputer is not limited to any particular hardware configuration. In one example, the microcomputer includes: an interface (I/F) to transmit and receive information, such as print data, to and from an external device, such as a host computer; a central processing unit (CPU) to execute commands included in a printing control program; a read-only memory (ROM) storing programs to be executed by the CPU; a random-access memory (RAM) to be used as a working area where the programs are to be expanded; and a memory storing various data, such as the printing control program. The controller 100 may include a rewritable programmable logic device, such as a field-programmable gate array (FPGA). In one example, the FPGA may include a CPU core provided by an integrated circuit, a multiplier, a RAM, and related peripheral circuitry.
The printing controller 106 is electrically connected to the ink heads 32, the feed motor, and the scan motor. In accordance with the printing control program and the print data stored in the memory, the printing controller 106 causes the scan motor to move the carriage 31 in the main scanning direction Y at a predetermined speed. The printing controller 106 then causes the ink heads 32 mounted on the carriage 31 to discharge ink from predetermined positions based on the print data. This operation and movement of the recording medium 8 in the sub-scanning direction X caused by the feed motor are repeatedly carried out in an alternating manner. Thus, the printer 1 effects printing in accordance with the print data.
The first controller 101 performs capping (S1 in
The second controller 102 performs main suction (S2 in
The third controller 103 makes a pressure equalizing adjustment (S3 in
The fourth controller 104 performs idle suction (S4 in
The fifth controller 105 performs de-capping (S5 in
In the present preferred embodiment, the cap unit 40 includes the table wall 41b standing vertically or substantially vertically on the end of the movable table 41 facing in the first direction Y1. The composite cap valves 47 are disposed on the table wall 41b. The number of composite cap valves 47 increases in accordance with an increase in the number of ink heads 32. The table wall 41b is disposed such that the table wall 41b does not interfere with movement of the ink head unit 30. The composite cap valves 47 are disposed on the table wall 41b such that the composite cap valves 47 are arranged not only in a horizontal or substantially horizontal direction but also in a vertical or substantially vertical direction. Accordingly, if the number of ink heads 32 is increased, disposing the composite cap valves 47 on the table wall 41b standing vertically or substantially vertically in the up-down direction Z would provide the cap unit 40 without excessively increasing the area where the printer 1 is to be installed. Consequently, the present preferred embodiment provides the printer 1 that is readily adaptable to an increase in the number of ink heads 32.
In the present preferred embodiment, the table wall 41b of the movable table 41 is provided by bending a single steel plate that defines the movable table 41. Providing the table wall 41b in this manner enables the table wall 41b to be securely disposed on the movable table 41. Providing the table wall 41b in this manner reduces the number of components of the cap unit 40. This is advantageous in terms of manufacturing the printer 1 and keeping the printer 1 in a good condition.
In the present preferred embodiment, the movable table 41 includes the movement stopper 41c protruding upward. The ink head conveyor includes: the carriage 31 supporting the ink heads 32; the carriage conveyor to move the carriage 31 in the main scanning direction Y; and the engagement portion 31A disposed on the carriage 31 to come into engagement with the movement stopper 41c. With the engagement portion 31A in engagement with the movement stopper 41c, the carriage conveyor moves the carriage 31 from the first location R1 to the second location R2 (which is located in the first direction Y1 relative to the first location R1) in the first direction Y1. This moves the movable table 41 from the retracted position to the cap attaching position. With the engagement portion 31A in engagement with the movement stopper 41c, the carriage conveyor moves the carriage 31 from the second location R2 to the first location R1 in the second direction Y2. This moves the movable table 41 from the cap attaching position to the retracted position. Thus, the carriage conveyor to move the carriage 31 in the main scanning direction Y enables movement of the movable table 41 between the retracted position and the cap attaching position. Consequently, the present preferred embodiment makes it possible to move the cap unit 40 without providing power to be used exclusively for the cap unit 40.
In the present preferred embodiment, the cap unit 40 includes the composite cap valves 47 each including the first cap valve 45 and the second cap valve 45 integral with each other. Each composite cap valve 47 includes the composite valve case 47a, the first piston valve element 45f, the first rod 45h, the spring 45j, the second piston valve element 47f, the second rod 47h, and the spring 47j. The composite valve case 47a includes the first inner passage 45b and the second inner passage 47b. The first piston valve element 45f is held in the composite valve case 47a to move in the up-down direction Z so as to switch the first inner passage 45b between the open state and the closed state. The first rod 45h protrudes from the first piston valve element 45f in the main scanning direction Y and at least partially extends out of the composite valve case 47a. The spring 45j is held in the composite valve case 47a and defines and functions as a first elastic member to urge the first piston valve element 45f upward or downward so as to close the first inner passage 45b. The second piston valve element 47f is held in the composite valve case 47a to move in the up-down direction Z so as to switch the second inner passage 47b between the open state and the closed state. The second rod 47h protrudes from the second piston valve element 47f in the main scanning direction Y and at least partially extends out of the composite valve case 47a. The spring 47j is held in the composite valve case 47a and defines and functions as a second elastic member to urge the second piston valve element 47f upward or downward so as to close the second inner passage 47b. Thus, the two cap valves 45 included in each composite cap valve 47 and in communication with associated two of the caps 42 to be attached to the ink heads 32 are integral with each other. Accordingly, when the ink heads 32 are arranged in pairs in the sub-scanning direction X so as to effect printing with a print span doubled for each round of scanning, two of the opening passages 44a are connected to an associated one of the composite cap valves 47, so that the opening passages 44a connect the associated pair of caps 42 to the associated pair of cap valves 45. This simplifies the arrangement of the passages. Such an arrangement makes it possible to reduce the number of components. Consequently, the present preferred embodiment provides the printer 1 that is readily adaptable to an increase in the number of ink heads 32.
In the present preferred embodiment, the composite valve case 47a includes the through hole 47k passing through the composite valve case 47a in the up-down direction Z. The through hole 47k is located between the first cap valve area A and the second cap valve area B. The first cap valve area A includes the first inner passage 45b, the first piston valve element 45f, the first rod 45h, and the spring 45j (i.e., the first elastic member). The second cap valve area B includes the second inner passage 47b, the second piston valve element 47f, the second rod 47h, and the spring 47j (i.e., the second elastic member). The composite cap valves 47 include at least first composite cap valves 47 and second composite cap valves 47. The first composite cap valves 47 are disposed on the table wall 41b such that the first composite cap valves 47 are located above the second composite cap valves 47 and out of alignment with the second composite cap valves 47 in a direction perpendicular to the up-down direction Z. The opening passages 44a (i.e., the first passages) each connected to at least one of the first inlet 45c and the second inlet 47c of the associated first composite cap valve 47 is inserted through the through hole 47k of the associated second composite cap valve 47. Thus, when the composite valve cases 47a are arranged on the table wall 41b in a vertical or substantially vertical direction, for example, the passages (or tubes) connected to the upper composite valve cases 47a are allowed to extend to a region below the movable table 41 through the through holes 47k of the lower composite valve cases 47a. This saves space occupied by the cap unit 40. The present preferred embodiment prevents the passages connected to the composite valve cases 47a from interfering with the opening and closing of the composite cap valves 47 during movement of the movable table 41 between the cap attaching position and the valve opening position.
In the present preferred embodiment, the base 51 of the conveyor 50 includes the right side wall 52. The right side wall 52 is a side wall standing vertically or substantially vertically on the end of the base 51 facing in the first direction Y1. The right side wall 52 includes the lifters 52A at locations where the right side wall 52 faces the first and second rods 45h and 47h of the first composite cap valve 47 and the first and second rods 45h and 47h of the second composite cap valve 47. Each lifter 52A defines and functions as a valve opening surface that extends between a height corresponding to the height of the rods 45h and 47h of the associated composite cap valve 47 including inner passages 45b and 47b that are respectively closable by the piston valve elements 45f and 47f and a height corresponding to the height of the rods 45h and 47h of the associated composite cap valve 47 including inner passages 45b and 47b respectively opened by the piston valve elements 45f and 47f, such that the valve opening surface inclines upward as it extends in the first direction Y1 and intersects the main scanning direction Y and the up-down direction Z. The valve opening surfaces are not located over the first rods 45h or the second rods 47h. For example, suppose that the first and second composite cap valves 47 are detached, together with the movable table 41, from the conveyor 50 for maintenance of the cap unit 40. In such a case, the first and second rods 45h and 47h protruding from the first and second composite cap valves 47 are prevented from being caught by the valve opening surfaces. Thus, the present preferred embodiment facilitates detachment of the movable table 41 from the conveyor 50 and prevents the first and second rods 45h and 47h from being damaged during detachment of the movable table 41.
Although the preferred embodiments of the present invention have been described thus far, the foregoing preferred embodiments are only illustrative and the present invention may be embodied in various other forms.
In the foregoing preferred embodiments, the printer 1 includes the composite cap valves 47 each including the first and second cap valves 45 that are preferably integral with each other, for example. The printer 1, however, does not necessarily have to include the composite cap valves 47. When the printer 1 includes no composite cap valves 47, each of the cap valves 45 may include: a valve case (not illustrated) including the inner passage 45b; the piston valve element 45f held in the valve case and movable in the up-down direction Z so as to switch the inner passage 45b between the open state and the closed state; the rod 45h protruding from the piston valve element 45f in the main scanning direction Y and at least partially extending out of the valve case; and the spring 45j held in the valve case and defining and functioning as an elastic member to urge the piston valve element 45f upward or downward so as to close the inner passage 45b. In other words, each of the cap valves 45 may be a valve to switch a single passage between the open state and the closed state. The base 51 may include the right side wall 52 that is a side wall standing vertically or substantially vertically on the end of the base 51 facing in the first direction Y1. The right side wall 52 includes the lifters 52A at locations where the right side wall 52 faces the cap valves 45. Each lifter 52A defines and functions as a valve opening surface that extends between a height corresponding to the height of the rod 45h of the associated cap valve 45 including an inner passage 45b closable by the piston valve element 45f and a height corresponding to the height of the rod 45h of the associated cap valve 45 including an inner passage 45b opened by the piston valve element 45f, such that the valve opening surface inclines upward as it extends in the first direction Y1 and intersects the main scanning direction Y and the up-down direction Z. With the engagement portion 31A in engagement with the movement stopper 41c, the carriage conveyor may move the carriage 31 from the second location R2 to the third location R3 (which is located in the first direction Y1 relative to the second location R2) in the first direction Y1. This causes the rods 45h to abut against the valve opening surfaces and lifts the rods 45h along the valve opening surfaces so as to open the cap valves 45. With the engagement portion 31A in engagement with the movement stopper 41c, the carriage conveyor may move the carriage 31 from the third location R3 to the second location R2 in the second direction Y2. This lowers the rods 45h along the valve opening surfaces so as to close the cap valves 45. Similarly to the preferred embodiments described above, such an arrangement enables movement of the movable table 41 and opening and closing of the cap valves 45 without providing power to be used exclusively for the cap unit 40.
In the foregoing preferred embodiments, the conveyor 50 moves the movable table 41 in the main scanning direction Y and the up-down direction Z. The conveyor 50, however, may move the movable table 41 in any suitable direction(s). In one example, the conveyor 50 may move the movable table 41 only in the up-down direction Z. In another example, the conveyor 50 may move the movable table 41 in the main scanning direction Y, the up-down direction Z, and the sub-scanning direction X.
In the foregoing preferred embodiments, the right side wall 52 includes the first right side wall 52d and the second right side wall 52u. The second right side wall 52u is connected to the upper portion of the first right side wall 52d. The first lifters 52A1 are provided on the first right side wall 52d by bending the upper end of the first right side wall 52d. The second lifters 52A2 are provided on the second right side wall 52u by bending the upper end of the second right side wall 52u. The first and second lifters 52A1 and 52A2, however, may be provided in any other manner. In one example, the second lifters 52A2 may be provided by bending the upper end of the right side wall 52 that extends to a height corresponding to the height of the rods 45h and 47h of the upper composite cap valves 47 in the closed state. In such an example, the first lifters 52A1 may be separate from the right side wall 52 and connected to the right side wall 52 at a height corresponding to the height of the rods 45h and 47h of the lower composite cap valves 47 in the closed state. Such an arrangement makes it possible to strengthen the right side wall 52 and provide the right side wall 52 and the lifters 52A without increasing the number of components.
The printer 1 may include a cleaner (not illustrated) to wipe the nozzle surfaces of the ink heads 32 and/or clean a member used to wipe the nozzle surfaces. The cleaner may be disposed inside the side cover 15 and leftward of the cap unit 40 such that the cleaner is located side by side with the cap unit 40. Thus, the cleaner performs additional cleaning after suction cleaning. Specifically, the cleaner wipes the nozzle surfaces of the ink heads 32 that have undergone suction cleaning.
In the foregoing preferred embodiments, the printer 1 includes the platen 6, on which the recording medium 8 is to be placed, such that the recording medium 8 is conveyed in the sub-scanning direction X by the grit rollers 16. The printer 1, however, is not limited to such a configuration. In one example, the printer 1 may be a “flatbed printer”. The printer 1 may include a table to move the recording medium 8 in the main scanning direction Y and the sub-scanning direction X.
The terms and expressions used herein are for description only and are not to be interpreted in a limited sense. These terms and expressions should be recognized as not excluding any equivalents to the elements shown and described herein and as allowing any modification encompassed in the scope of the claims. The present invention may be embodied in many various forms. This disclosure should be regarded as providing preferred embodiments of the principles of the present invention. These preferred embodiments are provided with the understanding that they are not intended to limit the present invention to the preferred embodiments described in the specification and/or shown in the drawings. The present invention encompasses any of preferred embodiments including equivalent elements, modifications, deletions, combinations, improvements and/or alterations which can be recognized by a person of ordinary skill in the art based on the disclosure. The elements of each claim should be interpreted broadly based on the terms used in the claim, and should not be limited to any of the preferred embodiments described in this specification or referred to during the prosecution of the present application.
While preferred embodiments of the present invention have been described above, it is to be understood that variations and modifications will be apparent to those skilled in the art without departing from the scope and spirit of the present invention. The scope of the present invention, therefore, is to be determined solely by the following claims.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2017-150156 | Aug 2017 | JP | national |
| 2018-107668 | Jun 2018 | JP | national |
