Patent Grant
10836170
This patent application is based on and claims priority pursuant to 35 U.S.C. § 119(a) to Japanese Patent Application No. 2018-142364, filed on Jul. 30, 2018 in the Japan Patent Office, the entire disclosure of which is hereby incorporated by reference herein.
The present disclosure relates to a head protector, a liquid discharge head, and a liquid discharge apparatus.
A recording apparatus of an ink discharge type (inkjet recording apparatus or liquid discharge apparatus) includes a liquid discharge head (droplet discharge head) and is used as an image forming apparatus such as a printer, a facsimile, a copier, a plotter, and a multifunction peripheral, for example. Hereinafter, the “liquid discharge head” is simply referred to as the “head”. The head includes nozzle surface on which a plurality of nozzles are formed. The head discharges a liquid from the plurality of nozzles onto a recording medium to form an image on the recording medium.
When an image is continuously formed by the liquid discharge apparatus that includes the head, the nozzles from which the liquid is discharged may be clogged with the hardened ink. Further, liquid droplets or foreign matter may adhere to the nozzle surface, and may be deposited and solidified on the nozzle surface. The liquid droplets or foreign matter adhered, deposited, or solidified on the nozzle surface may cause non-discharge of liquid from the nozzles, bending of discharge direction of the liquid, and the like. Thus, it is necessary to periodically remove the liquid droplets and the foreign matter adhered to the nozzle surface with a wiper or the like to prevent the occurrence of the discharge failure of the liquid droplets.
The head includes a head protector (hereinafter, also referred to as a “nozzle cover”) that covers a peripheral edge of a nozzle surface to prevent a wiper that cleans the nozzle surface from being damaged by the edge of the nozzle surface.
The nozzle cover may cover all sides of periphery of the nozzle surface that includes four edges of the nozzle surface. However, if entire periphery of the nozzle surface is covered with the nozzle cover, each ends of the wiper contacts the nozzle cover, and a central portion of the wiper is separated from the nozzle surface. Thus, the wiper cannot wipe the nozzle surface.
Therefore, the wiper is pressed against the nozzle surface and is elastically deformed to contact the nozzle surface. Then, the wiper may not sufficiently wipe the residual ink (liquid droplets) adhered on a region of the nozzle surface closed to the nozzle cover.
In an aspect of this disclosure, a head protector to be mounted to a liquid discharge head including a nozzle surface on which nozzles to discharge a liquid is formed is disclosed. The head protector includes a cover surface to cover a part of the nozzle surface of the liquid discharge head, a fitting surface to be fitted to an attachment portion on a first side surface of the liquid discharge head, the first side surface intersecting the nozzle surface, and a biasing surface including a biasing part to bias the head protector against a second side surface of the liquid discharge head in a direction parallel to the nozzle surface, the second side surface intersecting the first side surface and the nozzle surface.
The aforementioned and other aspects, features, and advantages of the present disclosure will be better understood by reference to the following detailed description when considered in connection with the accompanying drawings, wherein:
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.
In describing embodiments illustrated in the drawings, specific terminology is employed for the sake of clarity. However, the disclosure of this patent 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 the same function, operate in an analogous manner, and achieve similar results.
Although the embodiments are described with technical limitations with reference to the attached drawings, such description is not intended to limit the scope of the disclosure and all the components or elements described in the embodiments of this disclosure are not necessarily indispensable. 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.
Hereinafter, a liquid discharge head protector, a liquid discharge head, and a liquid discharge apparatus according to the present disclosure is described with reference to the drawings. Note that the present disclosure is not limited to the following embodiments and may be other embodiments. The following embodiments may be modified by, e.g., addition, modification, or omission within the scope that would be obvious to one skilled in the art. Any aspects having advantages as described for the following embodiments according to the present disclosure are included within the scope of the present disclosure.
The liquid discharge head protector according to the present disclosure is a protector mounted on a liquid discharge head that has a nozzle surface on which a plurality of nozzles are formed. Hereinafter, the “liquid discharge head protector” is simply referred to as the “head protector”.
[Liquid Discharge Head]
In the present application, the “liquid discharge head” is a functional component that discharges a liquid from a nozzle. The nozzle is also referred to as a nozzle-hole. Hereinafter, the “liquid discharge head” is simply referred to as the “head”.
Liquid to be discharged from the nozzles of the head is not limited to a particular liquid as long as the liquid has a viscosity or surface tension to be discharged from the liquid discharge head. However, preferably, the viscosity of the liquid is not greater than 30 mPa·s under ordinary temperature and ordinary pressure or by heating or cooling.
Examples of the liquid include a solution, a suspension, or an emulsion that contains, for example, a solvent, such as water or an organic solvent, a colorant, such as dye or pigment, a functional material, such as a polymerizable compound, a resin, or a surfactant, a biocompatible material, such as DNA, amino acid, protein, or calcium, or an edible material, such as a natural colorant.
Such a solution, a suspension, or an emulsion can be used for, e.g., inkjet ink, surface treatment solution, a liquid for forming components of electronic element or light-emitting element or a resist pattern of electronic circuit, or a material solution for three-dimensional fabrication.
Examples of an energy source to generate energy to discharge liquid include a piezoelectric actuator (a laminated piezoelectric element or a thin-film piezoelectric element), a thermal actuator that employs a thermoelectric conversion element, such as a heating resistor, and an electrostatic actuator including a diaphragm and opposed electrodes.
The terms “image formation”, “recording”, “printing”, “image printing”, and “fabricating” used herein may be used synonymously with each other.
The head to which the head protector according to the present disclosure is fitted is described according to
The head 404 according to the present embodiment has a head body 7 and a cable portion 8 as illustrated in
The head body 7 includes a chamber part 11, a drive controller 3, a heat radiation member 1, and a cover 4. The chamber part 11 drives a pressure generation element 10 to apply pressure to a liquid in a pressure chamber and discharges the liquid from the nozzle. The drive controller 3 controls to drive the pressure generating element 10. The heat radiation member 1 is in contact with the drive controller 3.
Further, the head 404 includes a wiring to transmit a signal to the drive controller 3. The wiring is separable from the head body 7 including the heat radiation member 1. Specifically, as illustrated in
The cable 8 as the wiring includes the higher-order device transmission wiring 2b and a relay wiring 2a. The higher-order device transmission wiring 2b is bendable and is connected to a connector board 5. The higher-order device transmission wiring 2b transmits electrical signal from the higher-order device via a connector 6. The relay wiring 2a electrically connects the higher-order device transmission wiring 2b and the pressure generating element 10.
The drive controller 3 is mounted on the relay wiring 2a and controls to drive the pressure generation element 10 based on the electric signal from the higher-order device.
The cover 4 accommodates and protects the relay wiring 2a and the drive controller 3.
The heat radiation member 1 (heat sink) radiates heat generated from the drive controller 3 outside the head body 7.
In an example of a configuration illustrated in
A configuration example of the chamber part 11 is described with reference to
The chamber part 11 includes the frame member 20, a filter plate 13, a manifold 14, a diaphragm 15, a restrictor plate 16, and a nozzle plate 17 (orifice plate). Lamination from the filter plate 13 to the nozzle plate 17 forms the channel member 12.
The diaphragm 15 is bonded to the pressure generating element 10.
When a voltage is applied to the pressure generation element 10 bonded to a stainless steel (SUS) base, the pressure generation element 10 distorts to compress the individual chamber formed of the restrictor plate 16 through the diaphragm 15, and the liquid (ink) is thus discharged from the nozzles in the nozzle plate 17. Heat is generated in the drive controller 3 during the liquid discharge. The heat radiation member 1 bonded to the drive controller 3 release the heat generated at the drive controller 3 outside the head body 7.
In the following description, the frame member 20 holding the channel member 12 is described as a member holding the nozzle plate 17. The channel member 12 is, specifically, a member from the filter plate 13 to the restrictor plate 16. The member holding the nozzle plate 17 is described as a chamber forming member.
The chamber part 11 includes at least the nozzle plate 17, the channel member 12, and the frame member 20.
The head 404 according to the present embodiment includes a nozzle plate 17, a restrictor plate 16, a frame member 20, ad diaphragm 15, a pressure generating element 10, and a drive integrated circuit (IC). The nozzle plate 17 includes a plurality of nozzles 44 arranged in the nozzle array direction to discharge liquid droplets. The restrictor plate 16 is bonded to the nozzle plate 17 to form a plurality of individual chambers 41 communicating with the nozzles 44, respectively.
The frame member 20 as a common chamber forms a common chamber 40 to supply liquid to the plurality of individual chambers 41. The diaphragm 15 disposed on a surface opposite to a surface of the restrictor plate 16 on which the nozzle plate 17 is bonded. The pressure generation element 10 is formed on the diaphragm 15. The drive IC applies a voltage to the pressure generation element 10.
The liquid in the common chamber 40 is supplied to the individual chamber 41 from an opening 43 of the diaphragm 15 through a fluid restrictor 42. The liquid is supplied to the common chamber 40 from a liquid storage through the supply channel.
The common chamber 40 is always kept being filled with the liquid.
The diaphragm 15 forms a part of a wall of the individual chamber 41. Expansion and contraction of the pressure generation element 10 deforms the diaphragm 15 to generate volume change in the individual chamber 41 a pressure change of the liquid in the individual chamber 41. Thus, the head 404 discharges the liquid in the individual chamber 41 from the nozzle 44.
[Head Protector]
The head protector 30 prevents a wiper 50 to be damaged by an end of the nozzle surface 17a when the nozzle surface 17a is wiped by the wiper in the above-described head. Further, the head protector 30 prevents the nozzle plate 17 to be peeled off by the wiper 50 contacting the nozzle plate 17.
The head protectors 30 are mounted to the frame member 20 so that the head protectors 30 cover each ends of the nozzle surface 17a and a part of the frame member in a longitudinal direction of the frame member 20. Specifically, each of the head protectors 30 is attached to the frame member 20 such that the head protector 30 covers one end of the nozzle surface 17a in a wiping direction Dw of the wiper 50.
As illustrated in
Note that a part of the side surface of the frame member 20 at the transverse direction side is also covered with the head protector 30.
The head protectors 30 have a configuration to individually cover each ends of the nozzle surface 17a and the frame member 20 in the wiping direction Dw with separate members.
Each of the head protectors 30 includes a fitting structure 31 that can be respectively fitted to the attachment portions 21 formed on the frame member 20. The attachment portion 21 and the fitting structure 31 constitute a fitting portion F indicated by a broken circle in the
The attachment portion 21 formed on the frame member 20 preferably includes a projection or a claw-like convex portion. The fitting structure 31 preferably includes a recess or an opening that can be fitted to the projection or the claw-like convex portion of the attachment portion 21.
If the recess is formed on the frame member 20 side, the recess has to be formed so that the recess does not interfere the channels, etc., inside the chamber part 11 that may increase the size of the frame member 20.
Conversely, if the head protector 30 includes a projection, the head protector 30 may not be reliably fitted to the frame member 20 by the projection of the head protector 30 because the head protector 30 is preferably formed of a thin plate-like member with an elastically deformable material.
Further, a fitting hole formed in the head protector 30 has to have a shape not to be deformed by a force concentratedly received by the wiping operation of the wiper. The deformation of the fitting hole may increase the displacement of the head protector 30.
It is described below a configuration in which the attachment portion 21 includes a fitting projection 23 and the fitting structure 31 includes a fitting hole 38. The configuration of the fitting portion F is not limited to the above-described configurations.
In
When the head protector 30 is fixed at a position to increase the clearance (a left end of the fitting projection 23 contacts a left end of the fitting hole 38 in
As described above, the attachment portion 21 includes a projection, and the fitting surface 30b includes a hole to which the projection of the attachment portion 21 is fittable. The hole has a size larger than the projection in the direction parallel to the nozzle surface 17a to form a gap “G”.
As illustrated in
To prevent the displacement of the head protector 30 as illustrated in
Peeling off of the head protector 30 may damage the nozzle surface 17a or may affect image quality of the image forming apparatus.
Conversely, the head protector 30 according to the present disclosure includes a biasing part 32 to reduce the displacement of the head protector 30 with a bias force of the biasing part 32. That is, the head protector 30 according to the present disclosure can prevent the movement of the head protector 30 accompanied with the operation of the wiper 50 by the bias force of the biasing part 32. Thus, the head protector 30 can prevent abrasion of a water-repellent film on the nozzle surface 17a due to rubbing of the nozzle surface 17a by the head protector 30.
The head protector 30 according to the present disclosure includes a cover surface 30c that covers a part of the nozzle surface 17a, a fitting surface 30b that fits on the attachment portion 21 on the head 404, and a biasing surface 30a including a biasing part 32 that intersects the fitting surface 30b. A bias direction of the head protector 30 by the biasing part 32 is substantially parallel to the wiping direction Dw of the wiper 50 to wipe the nozzle surface 17a. Further, the fitting surface 30b is substantially parallel to the wiping direction Dw.
In other words, a biasing surface 30a of the head protector 30 includes a biasing part 32 to bias the head protector 30 against a second side surface (a surface of the frame member 20 facing the biasing surface 30a) of the head 404 in a direction parallel to the nozzle surface 17a. The second side surface intersects (perpendicular to) the first side surface (a surface of the frame member 20 facing the fitting surface 30b) and the nozzle surface 17a.
The biasing part 32 is preferably provided at a position that can effectively prevent the rotational movement of the fitting portion “F” which receives the moment force M as the wiper 50 moves.
Specifically, a center of the biasing part 32 is preferably disposed above a center of the attachment portion 21 in a vertical direction perpendicular to the wiping direction Dw of the wiper 50 in which the nozzle surface 17a is positioned downward in the vertical direction. The attachment portion 21 fits to the fitting surface of the head protector 30.
Thus, a center of the biasing part 32 is disposed above a center of the attachment portion 21 to which the fitting surface 30b is fitted in a vertical direction perpendicular to the nozzle surface 17a, and the nozzle surface 17a is disposed below the center of the attachment portion 21 in the vertical direction.
The head protector 30 according to the present disclosure is attached and fitted to the head 404. The head 404 includes a nozzle plate 17 having a nozzle surface 17a in which a plurality of nozzles 44 are formed, a channel member 12 formed of a plurality of laminated plate members, and the chamber part 11 formed of the frame member 20.
The head protector 30 includes a cover surface 30c, a pair of fitting surfaces 30b, and a biasing surface 30a. The cover surface 30c covers at least one end of the nozzle surface 17a in the wiping direction Dw of the wiper 50. The pair of fitting surfaces 30b is fittable to the attachment portions 21 provided on both sides in the longitudinal direction of the frame member 20. The biasing surface 30a contacts a surface of the frame member 20 in the transverse side of the frame member 20. The biasing surface 30a includes a biasing part 32 to press the frame member 20 when the head protector 30 is fitted to the frame member 20.
The bias direction of the biasing part 32 is substantially parallel to the wiping direction Dw, and the biasing part 32 biases the head protector 30 in a direction away from the frame member 20. The fitting surface 30b is substantially parallel to the wiping direction Dw.
In other words, a biasing surface 30a of the head protector 30 includes a biasing part 32 to bias the head protector 30 against a second side surface (a surface of the frame member 20 facing the biasing surface 30a) of the head 404 in a direction parallel to the nozzle surface 17a. The second side surface intersects (perpendicular to) the first side surface (a surface of the frame member 20 facing the fitting surface 30b) and the nozzle surface 17a.
Further, the fitting structure 31 of the fitting surface 30b is a structure that fits to the attachment portion 21 of the frame member 20 with a clearance. The displacement generated in a range of the clearance of the fitting structure 31 is preferably reduced by the bias force of the biasing part 32.
Thus, a pair of fitting surfaces 30b is opposed to each other, and the pair of fitting surfaces 30b is perpendicular to the biasing surface 30a.
In the present embodiment, the attachment portion 21 formed on the frame member 20 is a fitting projection, and the fitting structure 31 of the fitting surface 30b is a fitting hole that is fittable to the fitting projection with a clearance with the fitting projection.
As illustrated in
The plate thickness of the head protector 30 is preferably small, for example, preferably 0.1 mm or less. With an increase in the plate thickness of the head protector 30, a resistance occurred between the wiper 50 and the head protector 30 increases when the wiper 50 passes an edge of the cover surface 30c of the head protector 30. Thus, the wiper 50 may be damaged by the edge of the cover surface 30c of the head protector 30.
Further, the head protector 30 is preferably applied with a water repelling treatment. The water-repellent treatment may be applied on all or part of the surface of the head protector 30. The water-repellent treatment is preferably applied at least to the cover surface 30c of the head protector 30 because the cover surface 30c contacts the nozzle surface 17a and the liquid (ink).
A well-known water repelling treatment may be applied to the head protector 30. For example, the head protector 30 may be coated with a water-repellent material to form a water-repellent film etc. on the head protector 30.
As illustrated in
In
When the head protector 30 is fitted to the frame member 20, there is a gap G existed between the head protector 30 and the frame member 20 because of the clearance of the fitting portion F. However, the head protector 30 can be fixed to the frame member 20 at a position where the gap G is increased to the maximum value by the biasing part 32. Thus, the head protector 30 according to the present disclosure can reduce the displacement occurred by the clearance.
The head protector 30 is preferably formed of an elastic member.
As the elastic member for the head protector 30, a hard metal material such as a stainless steel (SUS) material may be used. The head protector 30 is preferably formed of a thin material that can obtain a sufficient bias force. For example, it is preferable to use a SUS304-CSP-H-TA material having a thickness of 0.1 mm or less.
The head protector 30 according to the present disclosure elastically deforms the biasing part 32 and presses the frame member 20. The biasing part 32 formed by an elastic member can quantify a state of close contact between the head protector 30 and the frame member 20 in mechanical design.
Further, controlling an amount of deformation of the head protector 30 at the time of attachment of the head protector 30 to the frame member 20 enable a state of close contact between the head protector 30 and the frame member 20 according to the clearance (gap G) as described-above. Thus, the present disclosure can reliably reduce the displacement of the head protector 30.
A shape of the biasing part 32 is not limited to the above-described embodiments as long as the biasing part 32 can be elastically deformed and has a convex shape projected toward the frame member 20.
An embodiment of the head protector 30 including the biasing part 32 having another shape is described below.
A second embodiment of the head protector 30 according to the present disclosure is described with referring to
The head protector 30 in
A third embodiment of the head protector 30 according to the present disclosure is described with referring to
The head protector 30 in
The head protector 30 in the present disclosure includes two slits 36 extending in the transverse direction (height direction in
A fourth embodiment of the head protector 30 according to the present disclosure is described with referring to
As illustrated in
Each of the head protectors 30 includes the biasing part 34 so that the head protector 30 according to the present disclosure can prevent the movement of the head protector 30 accompanied with the operation of the wiper 50 by the bias force of the biasing part 32. Thus, the head protector 30 can prevent abrasion of a water-repellent film on the nozzle surface 17a due to rubbing of the nozzle surface 17a by the head protector 30.
[Liquid Discharge Apparatus]
The liquid discharge apparatus 500 according to the present disclosure is an apparatus to drive the liquid discharge head to discharge a liquid. The liquid discharge apparatus 500 includes a liquid discharge head having a head protector according to the present disclosure or a liquid discharge device including the liquid discharge head.
The durability of the head 404 is improved by the head protector 30 according to the present disclosure, so the number of head replacements can be reduced.
The liquid discharge apparatus may be, for example, an apparatus capable of discharging liquid to a material to which liquid can adhere and an apparatus to discharge liquid toward gas or into liquid.
The “liquid discharge apparatus” may include devices to feed, convey, and eject the material on which liquid can adhere. The liquid discharge apparatus may further include a pretreatment apparatus to coat a treatment liquid onto the material, and a post-treatment apparatus to coat a treatment liquid onto the material, onto which the liquid has been discharged.
The “liquid discharge apparatus” may be, for example, an image forming apparatus to form an image on a sheet by discharging ink, or a three-dimensional fabrication apparatus to discharge a fabrication liquid to a powder layer in which powder material is formed in layers to form a three-dimensional fabrication object.
The “liquid discharge apparatus” is not limited to an apparatus to discharge liquid to visualize meaningful images, such as letters or figures. For example, the liquid discharge apparatus may be an apparatus to form arbitrary images, such as arbitrary patterns, or fabricate three-dimensional images.
The above-described term “material on which liquid can be adhered” represents a material on which liquid is at least temporarily adhered, a material on which liquid is adhered and fixed, or a material into which liquid is adhered to permeate.
Examples of the “material on which liquid can be adhered” include recording media, such as paper sheet, recording paper, recording sheet of paper, film, and cloth, electronic part, such as electronic substrate and piezoelectric element, and media, such as powder layer, organ model, and testing cell. The “material on which liquid can be adhered” includes any material on which liquid is adhered, unless particularly limited.
Examples of the “material on which liquid can be adhered” include any materials on which liquid can be adhered even temporarily, such as paper, thread, fiber, fabric, leather, metal, plastic, glass, wood, and ceramic.
Further, the term “liquid” includes any liquid having a viscosity or a surface tension that can be discharged from the liquid discharge head. However, preferably, the viscosity of the liquid is not greater than 30 mPa·s under ordinary temperature and ordinary pressure or by heating or cooling.
Examples of the liquid include a solution, a suspension, or an emulsion that contains, for example, a solvent, such as water or an organic solvent, a colorant, such as dye or pigment, a functional material, such as a polymerizable compound, a resin, or a surfactant, a biocompatible material, such as DNA, amino acid, protein, or calcium, or an edible material, such as a natural colorant. Such a solution, a suspension, or an emulsion can be used for, e.g., inkjet ink, surface treatment solution, a liquid for forming components of electronic element or light-emitting element or a resist pattern of electronic circuit, or a material solution for three-dimensional fabrication.
The “liquid discharge apparatus” may be an apparatus to relatively move the head and a material on which liquid can be adhered. However, the liquid discharge apparatus is not limited to such an apparatus. For example, the liquid discharge apparatus may be a serial head apparatus that moves the head or a line head apparatus that does not move the head.
Examples of the “liquid discharge apparatus” further include a treatment liquid coating apparatus to discharge a treatment liquid to a sheet to coat the treatment liquid on the surface of the sheet to reform the sheet surface and an injection granulation apparatus in which a composition liquid including raw materials dispersed in a solution is injected through nozzles to granulate fine particles of the raw materials.
The term “liquid discharge device” represents a unit in which the head and other functional parts or mechanisms are combined, in other words, an assembly of parts relating to the liquid discharge function. For example, the “liquid discharge device” includes a combination of the head with at least one of a head tank, a carriage, a supply unit, a recovery device, and a main scan moving unit.
Examples of the “single unit” include a combination in which the head and one or more functional parts and units are secured to each other through, e.g., fastening, bonding, or engaging, and a combination in which one of the head and the functional parts and units is movably held by another. The head may be detachably attached to the functional part(s) or unit(s) s each other.
Further, the liquid discharge device 440 includes the head 404 mounted on the carriage 403 in
As illustrated in
Alternatively, the head 404 and the head tank 441 coupled (connected) with a tube or the like may form the liquid discharge device 440 as a single unit. Here, a unit including a filter may further be added to a part between the head tank 441 and the head 404.
In another example, the liquid discharge device 440 may include the head 404 and the carriage 403 to form a single unit.
In still another example, the liquid discharge device 440 includes the head 404 movably held by the guide 401 that forms part of a main scan moving unit 493, so that the head 404 and the main scan moving unit 493 form a single unit. As illustrated in
The main scan moving unit 493 includes a guide 401, a main scanning motor 405, a timing belt 408, and the like. The main scan moving unit 493 functions as a drive device to move the carriage 403 in the main scanning direction MSD. The guide 401 is bridged between the left-side plate 491A and right-side plate 491B to moveably hold the carriage 403. The main scanning motor 405 reciprocally moves the carriage 403 in the main scanning direction MSD via the timing belt 408 bridged between a driving pulley 406 and a driven pulley 407.
In
In still another example, a cap that forms part of a recovery device 337 is secured to the carriage 403 mounting the head 404 so that the head 404, the carriage 403, and the recovery device 337 form a single unit to form the liquid discharge device 440.
Further, in still another example, the liquid discharge device 440 includes tubes 456 connected to the head 404 mounting a channel part 444 so that the head 404 and a supply unit form a single unit as illustrated in
Further, the channel part 444 is disposed inside a cover 442. Instead of the channel part 444, the liquid discharge device 440 may include the head tank 441. A connector 443 electrically connected with the head 404 is provided on an upper part of the channel part 444.
The main scan moving unit 493 may be a guide only. The supply unit may be a tube(s) only or a loading unit only.
The inkjet image forming apparatus 301 includes the liquid discharge device 440 in the printing assembly 302. The liquid discharge device 440 includes a carriage 313 movable in a main scanning direction MSD inside an apparatus body, recording heads 314 including the heads 404 according to the above-described embodiments mounted on the carriage 313, and ink cartridges 315 to supply ink to the recording heads 314 in an apparatus body.
The main scanning direction is indicated by arrow MSD in
Further, the inkjet image forming apparatus 301 (liquid discharge apparatus 500) includes a manual feed tray 305 to manually feed the recording sheets 303. When the recording sheet 303 fed from the sheet feeding cassette 304 or the manual feed tray 305 is conveyed to the printing assembly 302, the printing assembly 302 records a desired image onto the recording sheet 303. The recording sheet 303 is ejected to a sheet ejection tray 306 mounted on a rear side of the apparatus body.
The printing assembly 302 holds the carriage 313 with a main guide rod 311 and a sub-guide rod 312 so that the carriage 313 is slidably movable in the main scanning direction MSD. The main guide rod 311 and the sub-guide rod 312 are guides laterally bridged between left and right-side plates. The main scanning direciton MSD is parallel to a surface of the recording sheet 303.
The carriage 313 mounts a recording head 314 that includes four inkjet heads (heads 404) to discharge droplets of yellow (Y), cyan (C), magenta (M), and black (B) inks, respectively. Each of the heads 404 includes multiple of nozzles arrayed in a nozzle array direction.
The recording heads 314 is mounted on the carriage 313 so that the nozzle array direction intersecting the main scanning direction MSD. The recording head 314 is mounted on the carriage 313 so that the liquid is discharged downward Further, the ink cartridges 315 to supply ink of each color to the recording head 314 are exchangeably mounted on the carriage 313.
Each of the ink cartridges 315 has an atmosphere communication port, a supply port, and a porous body. The atmosphere communication port is disposed at an upper portion of each ink cartridges 315 to communicate with the atmosphere. The supply port is disposed at a lower portion of each ink cartridges 315 to supply ink to the recording heads 314. The porous body is disposed inside each ink cartridges 315 to be filled with ink. Ink to be supplied to the recording heads 314 is kept at a slight negative pressure in the ink cartridges 315 by capillary force of the porous body.
Although the recording heads 314 of each color are used in
Further, the inkjet head (head 404) used as the recording head 314 may be a piezo-type that applies pressure to the ink through a diaphragm 15 that forms a wall of the liquid chamber with an electromechanical transducer element such as a piezoelectric element, or a bubble-type that generates air bubbles with a heating resistor to pressurize the ink, or an electrostatic-type in which the diaphragm 15 is displaced by the electrostatic force generated between the diaphragm 15 and an electrode facing the diaphragm 15 to pressurize the ink. An inkjet head of an electrostatic type is used in the present disclosure.
A rear side (a downstream side in a sheet conveyance direction) of the carriage 313 is slidably fitted to the main guide rod 311, and a front side (an upstream side in a sheet conveyance direction) of the carriage 313 is slidably mounted to the sub-guide rod 312. The sheet conveyance direction along which the recording sheet 303 is conveyed is indicated by “SCD” in
To scan the carriage 313 in the main scanning direction MSD, a timing belt 320 is stretched between a driving pulley 318 driven and rotated by a main scanning motor 317 and a driven pulley 319. The timing belt 320 is secured to the carriage 313. The carriage 313 is reciprocally moved (scanned) by forward and reverse rotations of the main scanning motor 317.
The inkjet image forming apparatus 301 (liquid discharge apparatus 500) further includes a sheet feed roller 321, a friction pad 322, a sheet guide 323, conveyance rollers 324 and 325, and a leading end roller 326 to convey the recording sheet 303, which is set in the sheet feeding cassette 304, to a portion below the recording heads 314. The sheet feed roller 321 and the friction pad 322 separates and feeds the recording sheets 303 sheet by sheet from the sheet feeding cassette 304.
The sheet guide 323 guides the recording sheets 303. The conveyance roller 324 reverses and conveys the recording sheet 303 fed from the sheet feed roller 321. The conveyance roller 325 is pressed against a circumferential surface of the conveyance roller 324. The leading end roller 326 defines an angle at which the recording sheet 303 is fed from the conveyance rollers 324 and 325. The conveyance roller 324 is rotationally driven by a sub-scanning motor 327 via a gear train.
The inkjet image forming apparatus 301 (liquid discharge apparatus 500) further includes a print receiver 329 disposed below the recording heads 314. The print receiver 329 is a sheet guide to guide the recording sheet 303, which is fed from the conveyance roller 324, in a range corresponding to a range of movement of the carriage 313 in the main scanning direction MSD.
On a downstream side of the print receiver 329 in the sheet conveyance direction SCD, the inkjet image forming apparatus 301 (liquid discharge apparatus 500) includes a conveyance roller 331, a spur roller 332, a sheet ejection roller 333, a spur roller 334, and guides 335 and 336.
The conveyance roller 331 is driven to rotate with the spur roller 332 to feed the recording sheet 303 in a sheet ejection direction (sheet conveyance direction SCD). The sheet ejection roller 333 and the spur roller 334 further feed the recording sheet 303 to the sheet ejection tray 306. The guides 335 and 336 form a sheet ejection path.
In recording, the inkjet image forming apparatus 301 (liquid discharge apparatus 500) drives the recording heads 314 according to image signals while moving the carriage 313, to discharge ink onto the recording sheet 303, which is stopped below the recording heads 314, by one line of a desired image.
Then, the recording sheet 303 is fed by a predetermined amount and another line is recorded. When a recording end signal or a signal indicating that a rear end of the recording sheet 303 arrives at a recording area is received, a recording operation is terminated and the recording sheet 303 is ejected.
Further, a recovery device 337 to recover a discharge failure of the recording head 314 is disposed at a position out of the recording area on a right side in the moving direction of the carriage 313. The recovery device 337 includes a cap, a suction unit, and a cleaning unit.
In a print standby state, the carriage 313 is moved to a side at which the recovery device 337 is disposed, and the recording heads 314 are capped with the cap.
Accordingly, the nozzles 44 (discharge ports) are kept in a wet state, thus preventing discharge failure due to the drying of ink. The inkjet image forming apparatus 301 (liquid discharge apparatus 500) discharges ink not relating to the recording in the middle of the recording, for example, to maintain the viscosity of ink in all of the nozzles 44 constant, thus maintaining the head 404 to stably discharge the liquid (ink).
When a discharge failure has occurred, the nozzles 44 of the recording heads 314 are tightly sealed with the cap, the suction unit sucks ink and bubbles, for example, from the nozzles 44 via tubes, and the cleaning unit removes ink and dust adhered to the surfaces of the nozzles 44, thus recovering the recording head 314 from the discharge failure. The sucked ink is discharged to a waste ink container disposed on a lower portion of the apparatus body and is absorbed into and held in an ink absorber in the waste ink container.
Numerous additional modifications and variations are possible in light of the above teachings. Such modifications and variations are not to be regarded as a departure from the scope of the present disclosure and appended claims, and all such modifications are intended to be included within the scope of the present disclosure and appended claims.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2018-142364 | Jul 2018 | JP | national |
| Number | Name | Date | Kind |
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