JP2005131791A - Ink jet head and ink jet recorder - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain an ink jet head incorporating a filter in which a foreign matter mixed into the ink jet head under a state equipped with the filter is removed from a liquid drain outlet which is closed using the sealing member of an ink supply tube in the ink jet head. <P>SOLUTION: The frame member 10 of an ink jet head 44 is provided with a filter 13 and ink is supplied from an internal common ink channel 11 to each liquid chamber formed in the channel plate 1. Since a recess 14 is formed and a liquid drain outlet 15 is provided in the outer circumference of an ink supply tube 12 on the downstream side of the filter 13, the filter 13 can be cleaned from both the upstream side and downstream side, and a foreign matter 16 can be removed from the liquid drain outlet 15 without being blocked by the filter 13. When the ink jet head 44 and the ink supply member of an ink cartridge are coupled, the liquid drain outlet 15 is closed by a sealing member, e.g. an O-ring, being inserted into the recess 14. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an ink jet head and an ink jet recording apparatus, and more particularly, when removing foreign matter from the inside of an ink jet head having a filter therein, the ink jet head is cleaned in a state of being equipped with a filter, thereby improving the reliability of the ink jet head. The present invention relates to an ink-jet head and an ink-jet recording apparatus that maintain the above.

In general, an ink jet head used in an ink jet recording apparatus includes a large number of nozzles having a diameter of 10 μm and a liquid chamber. In such an ink jet recording apparatus, if foreign matter mixed in the ink jet head manufacturing process or foreign matter mixed in the ink cartridge flows into the ink jet head and enters the ink jet head, the nozzle is clogged with foreign matter, resulting in ejection failure. Caused recording quality to deteriorate.
In recent years, the processing capability of personal computers (PCs) has improved, and the speed of output devices has progressed. In the case of inkjet heads, an increase in the number of nozzles has been demanded as a response to speeding up, resulting in further ejection defects. There is a need to improve foreign matter removal means.

In an ink jet recording apparatus, in order to prevent the nozzles of the ink jet head from being blocked by foreign matters, it is necessary to provide a filter for removing foreign matters and bubbles in an ink supply system that supplies ink from the ink cartridge to the nozzles. Yes. However, it is difficult to remove foreign matter with the filter attached. Therefore, it is necessary to attach a filter after removing the foreign matter in the ink jet head. However, it requires a lot of labor and is not sufficient in the reliability of removing the foreign matter.
Therefore, many inventions characterized by removing foreign substances from the ink jet head are known, but the following inventions are known for the invention of the present application.

  In the “inkjet recording apparatus” of Patent Document 1, the ink inlet is arranged at the center and the ink outlet is arranged at the uppermost part to smooth the ink flow and eliminate the portion where the bubbles stay. This is an example in which the dust removing device is used, and the filter is washed alone.

  In the “inkjet head cleaning method” of Patent Document 2, a liquid feed pump is connected to an ink supply port side of an inkjet head in a cleaning container containing a cleaning liquid, and the cleaning container is placed in an ultrasonic cleaning machine. In this example, the cleaning liquid in the cleaning container is passed through the ink chamber inside the inkjet head from the nozzle by the liquid feeding pump while being applied, and is fed through the liquid feeding pump. is there.

  In the “inkjet recording apparatus” of Patent Document 3, a filter housing having a filter built in an inkjet head is connected via a flexible tube, and when the nozzle clogging due to foreign matter occurs in the inkjet head, the flexible tube or the filter housing is removed. If the ink flow path of the ink jet head is sucked and washed from the removed part, the foreign matter can be removed without being disturbed by the filter, and this is an example of washing with the filter removed from the ink jet head.

  Patent Document 4 “Inkjet Head Cleaning Method and Apparatus” applies a cleaning liquid and air to the common ink chamber from the tip of a nozzle (orifice) through the pressure chamber while applying a suction pressure to the common ink chamber of the inkjet head. In this example, the liquid discharge port is provided in the ink jet common liquid chamber.

Patent Document 5 discloses an “inkjet recording apparatus” in which an ink supply unit and a cleaning liquid introduction unit are connected to an inkjet head via valves, respectively, and when printing using ink is completed, the inkjet head is used by using the cleaning liquid introduction unit. This is an example in which clogging of nozzles and the like is prevented by replacing the ink inside with a cleaning liquid.
Japanese Patent Application No. 7-314705 Japanese Patent No. 3179332 Japanese Patent Application No. 11-34350 Japanese Patent No. 3108788 Japanese Patent Application No. 11-58776

  As described above, a conventional cleaning apparatus such as the method of cleaning the filter of Patent Document 1 alone, the method of ultrasonic cleaning of the inkjet head unit of Patent Document 2, and the method of removing and cleaning the filter of Patent Document 3 In the cleaning method, there is a possibility that dust may be generated when the filter unit is set, and it is necessary to clean the filter unit independently, which is expected to increase the cost. Therefore, as in the method for cleaning an inkjet head in Patent Document 4, a cleaning liquid discharge port is provided in the common ink chamber so that the inkjet head is cleaned with the filter unit mounted, but the cleaning liquid discharge port is blocked. A stopper is required separately.

  Therefore, the present invention reliably removes the filter generated during the manufacturing process and foreign matter in the inkjet head with the filter attached, even if the number of nozzles provided in the inkjet head is increased, and provides an ink supply means from the ink cartridge. It is an object of the present invention to provide an ink jet head that eliminates the possibility of foreign matter mixing at the time of mounting, and an ink jet recording apparatus equipped with the ink jet head.

  According to the first and second aspects of the present invention, the ink jet head provided with the filter is provided with the liquid discharge port at a predetermined position, so that the foreign matter in the ink jet head can be surely removed, and the ink does not cause ejection failure due to the foreign matter. An object of the present invention is to provide an inkjet head capable of discharging and capable of forming a high-quality image.

  A third object of the present invention is to remove foreign matters without obstructing the flow of fluid by making the opening area of the liquid discharge port larger than the opening area of the total number of nozzles.

  The invention of claim 4 is to use a member that seals between the ink supply means and the inkjet head without using a member only for closing the liquid discharge port, and to reduce the number of members. Objective.

  The object of the present invention is to reliably seal the liquid discharge port and prevent ink leakage due to deformation of the seal member.

  An object of the invention of claim 6 is to seal the liquid discharge port inexpensively and reliably.

  The invention of claim 7 is to obtain an ink jet recording apparatus capable of forming a high quality image without defective ejection by forming an ink jet recording apparatus using the ink jet head obtained by the invention of claims 1 to 6. And

  The invention of claim 1 comprises an ink common liquid chamber, a plurality of pressure liquid chambers, a nozzle communicating with the pressure liquid chamber, and a drive element formed corresponding to the pressure liquid chamber. In an ink jet head having a filter in an ink supply path for supplying ink from a cartridge, a liquid discharge port is provided in a downstream region in the vicinity of the filter.

  According to a second aspect of the present invention, in the ink jet head according to the first aspect, the liquid discharge port is disposed at a position of 10 mm or less from the filter.

  According to a third aspect of the present invention, in the ink jet head according to the first or second aspect, an opening area of the liquid discharge port is larger than a total opening area of the nozzles.

  According to a fourth aspect of the present invention, in the ink jet head according to any one of the first to third aspects, the liquid discharge port is sealed by a seal member when an ink supply member from the ink cartridge is mounted. .

  According to a fifth aspect of the present invention, in the ink jet head according to any one of the first to fourth aspects, the ink supply conduit of the ink jet head has a ring-shaped concave groove on the outer periphery, and the liquid discharge port is in the concave groove. It is formed.

  According to a sixth aspect of the present invention, in the ink jet head according to the fourth or fifth aspect, the seal member is an O-ring.

  A seventh aspect of the invention is an ink jet recording apparatus that forms an image on a recording medium by ejecting ink droplets from nozzles in accordance with driving energy generated by an actuator driven in response to a recording signal. A carriage including at least one of the inkjet heads according to any one of 6 to 6 and an ink chamber forming member that supplies at least one color of ink to the inkjet head.

  Since the ink jet head according to the first aspect includes the liquid discharge path downstream of the filter, foreign matters mixed in the ink jet head can be washed in a state where the filter is provided.

  In the ink jet head according to the second aspect, by arranging the liquid discharge path within 10 mm from the filter, it is possible to eliminate the stagnation of the flow in the vicinity of the filter and to efficiently remove the foreign matter in the vicinity of the filter.

  In the ink jet head according to the third aspect, the total opening area of the liquid discharge ports is larger than the total opening area of the total number of nozzles, so that foreign matters mixed in the ink jet head can be cleaned without hindering the flow of the cleaning liquid.

  The ink jet head according to claim 4 has a configuration in which the liquid discharge port is sealed by a seal member interposed at a joint portion between the ink supply member that guides ink from the ink cartridge to the ink jet head and the ink jet head. It is possible to close the liquid discharge port without adding.

  In the ink jet head according to the fifth aspect, since the liquid discharge port is formed in the concave groove of the ink supply pipe formed in a pipe shape, the seal member surely fits into the concave groove, and the liquid leakage is surely prevented. Can be prevented.

  In the ink jet head according to the sixth aspect of the present invention, since the seal member is an O-ring, liquid leakage can be prevented reliably and inexpensively.

  The ink jet recording apparatus according to claim 7 is equipped with an ink jet head having good cleaning properties, so that there is no ejection failure, and it can be easily removed even if a nozzle is clogged with foreign matter. Print quality can be achieved.

  According to the present invention, even when the number of nozzles provided in the ink jet head is increased, a filter generated during the manufacturing process and foreign matter in the ink jet head can be reliably removed in a state where the filter is mounted, and an ink supply means from an ink cartridge To provide an ink jet head that eliminates the possibility of foreign matter mixing at the time of mounting, and an ink jet recording apparatus equipped with the ink jet head, an ink common liquid chamber, a plurality of pressure liquid chambers, and the pressurization An ink supply line for an ink jet head in an ink jet head comprising a nozzle communicating with the liquid chamber and a drive element formed corresponding to the pressurized liquid chamber and having a filter in an ink supply path for supplying ink from the ink cartridge Has a ring-shaped groove on the outer periphery, and a liquid outlet is in the groove. It is those that have been made.

Embodiments of the present invention will be described below with reference to the accompanying drawings.
FIG. 6 is a perspective view showing a main configuration of an ink jet recording apparatus to which the ink jet head of the present invention is applied, and FIG. 7 is a side sectional view of the same configuration.
The ink jet recording apparatus of the present invention includes a carriage 43 movable in the main scanning direction inside the recording apparatus main body 31, a recording head including an ink jet head 44 mounted on the carriage 43, an ink cartridge 45 for supplying ink to the recording head, and the like. A configured printing mechanism 32 and the like are housed, and a paper feed cassette (or a paper feed tray) 34 on which a large number of sheets 33 can be stacked from the front side is detachably attached to the lower part of the apparatus main body 31. In addition, the manual feed tray 35 for manually feeding the paper 33 can be opened, the paper 33 fed from the paper feed cassette 34 or the manual feed tray 35 is taken in, and is required by the printing mechanism 32. After the image is recorded, it is discharged to a discharge tray 36 mounted on the rear side.

  The printing mechanism 32 holds the carriage 43 slidably in the main scanning direction (in the direction perpendicular to the paper in FIG. 7) with a main guide rod 41 and a sub guide rod 42, which are guide members horizontally mounted on left and right side plates (not shown). The carriage 43 has a recording head composed of an inkjet head 44 that ejects ink droplets of each color of yellow (Y), cyan (C), magenta (M), and black (Bk), and has a plurality of nozzle holes (ink ejection ports). Are arranged in a direction crossing the main scanning direction, and the ink droplet ejection direction is directed downward. The carriage 43 is mounted with replaceable ink cartridges 45 for supplying ink of each color to the recording head. The ink cartridge 45 has an air port that communicates with the atmosphere upward, a supply port that supplies ink to the inkjet head below, and a porous body filled with ink inside, and the capillary force of the porous body. Thus, the ink supplied to the inkjet head 44 is maintained at a slight negative pressure.

  Moreover, although the head of each color is used here as the ink jet head 44, it may be one ink jet head having nozzle holes for ejecting ink droplets of each color. Further, the ink jet head 44 used as a recording head is a piezoelectric type that pressurizes ink through a vibration plate that forms a liquid chamber wall surface by an electromechanical conversion element such as a piezoelectric element, or a bubble is generated by a heating resistor to generate ink. A bubble type that pressurizes, or an electrostatic type that pressurizes ink by displacing the diaphragm with an electrostatic force between the diaphragm that forms the wall surface of the ink flow path and the electrode facing it can be used. In this embodiment, a piezo ink jet head is used.

  Here, the carriage 43 is slidably fitted to the main guide rod 41 on the rear side (downstream side in the paper conveyance direction) and is slidably mounted on the sub guide rod 42 on the front side (downstream side in the paper conveyance direction). doing. In order to move and scan the carriage 43 in the main scanning direction, a timing belt 50 is stretched between a driving pulley 48 and a driven pulley 49 that are rotationally driven by a main scanning motor 47, and the timing belt 50 is attached to the carriage 43. The carriage 43 is reciprocated by the forward and reverse rotations of the main scanning motor 47.

  On the other hand, in order to convey the paper 33 set in the paper feed cassette 34 to the lower side of the ink jet head 44, the paper feed roller 51 and the friction pad 52 for separating and feeding the paper 33 from the paper feed cassette 34 and the paper 33 are guided. A guide member 53 for conveying, a conveyance roller 54 for reversing and conveying the fed paper 33, a conveyance roller 55 pressed against the peripheral surface of the conveyance roller 54, and a feeding angle of the sheet 33 from the conveyance roller 54 are defined. A tip roller 56 is provided. The conveyance roller 54 is rotationally driven by a sub-scanning motor 57 via a gear train.

  A printing receiving member 59 is provided as a paper guide member that guides the paper 33 fed from the transport roller 54 below the ink jet head 44 in accordance with the range of movement of the carriage 43 in the main scanning direction. A conveyance roller 61 and a spur 62 that are rotationally driven to send out the paper 33 in the paper discharge direction are provided on the downstream side of the printing receiving member 59 in the paper conveyance direction, and paper discharge that further feeds the paper 33 to the paper discharge tray 36. A roller 63 and a spur 64 and guide members 65 and 66 that form a paper discharge path are disposed.

  During recording, the inkjet head 44 is driven in accordance with the image signal while moving the carriage 43, thereby ejecting ink onto the stopped paper 33 to record one line. Record the line. Upon receiving a recording end signal or a signal that the trailing edge of the paper 33 has reached the recording area, the recording operation is terminated and the paper 33 is discharged.

  Further, a recovery device 67 for recovering the ejection failure of the inkjet head 44 is disposed at a position outside the recording area on the right end side in the movement direction of the carriage 43. The recovery device 67 has a cap unit, a suction unit, and a cleaning unit. While waiting for printing, the carriage 43 is moved to the recovery device 67 side and the inkjet head 44 is capped by the capping means, and the nozzle hole (ejection port) is kept in a wet state to prevent ejection failure due to ink drying. Further, by ejecting ink not related to recording during recording or the like, the ink viscosity of all the nozzle holes is made constant, and stable ejection performance is maintained.

  When a discharge failure occurs, the nozzle hole of the inkjet head 44 is sealed with a capping unit, and bubbles and the like are sucked out from the nozzle hole with the suction unit through the tube. The ink and dust adhering to the nozzle surface are cleaned by the cleaning unit. And the defective discharge is recovered. Further, the sucked ink is discharged to a waste ink reservoir (not shown) installed at the lower part of the main body and absorbed and held by an ink absorber inside the waste ink reservoir.

Next, an inkjet head according to an embodiment of the present invention will be described.
FIG. 1 is a sectional view showing an ink jet head to which the present invention is applied, and FIG. 2 is an exploded perspective view showing the ink jet head shown in FIG.
The inkjet head 44 includes a plurality of communication holes 2, a flow channel plate 1 made of a silicon substrate or the like in which each liquid chamber 3 serving as an ink flow channel is formed, and Ni electroforming or the like on the upper surface of the flow channel plate 1. A nozzle plate 5 having a plurality of nozzle holes 6 is joined, and a vibration plate 7 formed by Ni electroforming or the like is joined to the lower surface of the flow path plate 1 to constitute a liquid chamber portion. The liquid chamber 3 is separated into a common flow path side and an individual flow path side by a fluid resistance section 4, and an actuator section in which two rows of stacked piezoelectric elements 9 are provided on a base member 8 formed of metal on the lower surface of the diaphragm 7. Are joined. A frame member 10 having a common ink flow path 11 formed outside the piezoelectric element 9 is joined to the diaphragm 7 to supply ink to the individual liquid chambers 3.

  The ink jet head 44 configured as described above is displaced in the stacking direction of the piezoelectric elements 9 (vertical direction in FIG. 1) by applying a driving voltage to the piezoelectric elements 9, and the diaphragm 7 is moved to each individual liquid chamber side. Due to deformation and displacement, the volume of the liquid chamber 3 decreases, the pressure in the liquid chamber increases, and ink droplets are ejected from the nozzle holes 6 of the nozzle plate 5 through the communication holes 2.

FIG. 3 is a perspective view showing a frame member of the inkjet head.
The frame member 10, which is a constituent element of the inkjet head 44, has a common ink flow path 11 formed therein and is joined to the flow path plate 1 via the vibration plate 7, and the common ink flow path 11 is formed in the vibration plate 7. The ink is communicated with the common flow path of the liquid chamber 3 through the through-hole, and ink is supplied to each individual liquid chamber 3. The ink supply conduit 12 of the frame member 10 is in the shape of a circular pipe, and a filter 13 is attached to the inlet end by appropriate means such as welding.

  In the ink supply pipe 12, a concave groove 14 made of a ring-shaped V groove or the like is formed in the vicinity of the filter 13 and on the outer periphery of the downstream area, and an appropriate number of liquid discharge ports 15 are formed in the concave groove 14. Is provided. The position of the liquid discharge port 15 is preferably 10 mm or less from the filter 13 in order to eliminate the stagnation of the flow of the fluid when removing the foreign matter 16, and is actually determined each time by experiment.

FIG. 4 is a partial cross-sectional view of the ink jet head incorporating the frame member of FIG. 3, and shows an example in which the ink jet head is cleaned.
By providing the liquid discharge port 15 in the downstream portion of the filter 13, cleaning can be performed from both the upstream side of the filter 13 and the common ink flow path 11 side, and the foreign matter 16 is removed without being obstructed by the filter 13. be able to. Further, even if dust is generated when the ink supply means is mounted, which has been a problem in the past, there is no possibility that foreign matter is mixed into the inkjet head because the filter 13 is mounted.

FIG. 5 is a partial cross-sectional view illustrating a state where an ink supply member that couples the ink cartridge and the frame member is mounted on the inkjet head.
By disposing the liquid discharge port 15 in the concave groove 14 of the ink supply conduit 12 of the ink jet head 44, the seal member 22 can be sealed between the inner surface of the ink cartridge coupling port of the ink supply member 21 and the concave groove 14. The ink cartridge can be sealed without leakage. In addition, since the sealing member 22 is an O-ring, it can be reliably sealed at a low cost, and a member only for closing the liquid discharge port 15 is not required. Even if the ink supply member 21 is the ink cartridge itself, the same effect can be achieved.

It is sectional drawing which shows the inkjet head to which this invention is applied. It is a perspective view which decomposes | disassembles and shows the inkjet head shown in FIG. It is a perspective view which shows the frame member of an inkjet head. It is a figure which shows the inkjet head incorporating the frame member of FIG. 3 partially in cross section. FIG. 4 is a partial cross-sectional view illustrating a state where an ink supply member that couples an ink cartridge and a frame member is mounted on an inkjet head. 1 is a perspective view illustrating a configuration of a main part of an ink jet recording apparatus to which an ink jet head of the present invention is applied. It is a sectional side view of the inkjet recording device shown in FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Flow path plate, 2 ... Communication hole, 3 ... Liquid chamber, 4 ... Fluid resistance part, 5 ... Nozzle plate, 6 ... Nozzle hole, 7 ... Vibrating plate, 8 ... Base member, 9 ... Piezoelectric element, 10 ... Frame 11: Common ink flow path, 12: Ink supply conduit, 13: Filter, 14: Concave groove, 15: Liquid discharge port, 16: Foreign matter, 21 ... Ink supply member, 22 ... Seal member, 31 ... Recording device Main body 32 ... Printing mechanism section 33 ... Paper 34 ... Paper feeding cassette 35 ... Bypass tray 36 ... Discharge tray 41 ... Main guide rod 42 ... Sub guide rod 43 ... Carriage 44 ... Inkjet head 45 ... ink cartridge, 47 ... main scanning motor, 48 ... drive pulley, 49 ... driven pulley, 50 ... timing belt, 51 ... paper feed roller, 52 ... friction pad, 53 ... guide member, 54 ... transport roller, 5 ... conveying roller, 56 ... tip roller, 57 ... sub-scanning motor, 59 ... printing receiving member, 61 ... conveying roller, 62 ... spur, 63 ... discharge roller, 64 ... spur, 65, 66 ... guide member, 67 ... Recovery device.

Claims (7)

  Ink that supplies ink from an ink cartridge, comprising an ink common liquid chamber, a plurality of pressure liquid chambers, a nozzle communicating with the pressure liquid chamber, and a drive element formed corresponding to the pressure liquid chamber An ink jet head having a filter in a supply path, wherein a liquid discharge port is provided in a downstream region in the vicinity of the filter.   The inkjet head according to claim 1, wherein the liquid discharge port is disposed at a position of 10 mm or less from the filter.   The ink jet head according to claim 1, wherein an opening area of the liquid discharge port is larger than a total opening area of the nozzles.   The inkjet head according to claim 1, wherein the liquid discharge port is sealed by a seal member when an ink supply member from the ink cartridge is mounted.   The inkjet head according to any one of claims 1 to 4, wherein an ink supply conduit of the inkjet head has a ring-shaped concave groove on an outer periphery, and the liquid discharge port is formed in the concave groove. .   6. The ink jet head according to claim 4, wherein the seal member is an O-ring.   An inkjet recording apparatus that forms an image on a recording medium by ejecting ink droplets from nozzles in accordance with driving energy generated by an actuator that is driven in accordance with a recording signal. An ink jet recording apparatus comprising: a carriage including at least one head; and an ink chamber forming member that supplies at least one color of ink to the ink jet head.

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