1. Technical Field
This disclosure relates to an inkjet recording device for printing images on a printing medium by ejecting ink, and more particularly to a wiping device for eliminating fluid attached to the nozzle of the inkjet printer.
2. Description of the Related Art
An inkjet recording device is generally required to have a mechanism for maintaining the performance of the recording head that ejects ink droplets. As the functions of the mechanism, there are, for example, a capping function to prevent the nozzles ejecting ink droplets from dehydrating, a pumping function to fill the recording head with ink, and a nozzle cleaning function to clean the surface of the nozzle array of the recording head. Among those functions, the nozzle cleaning function is important, because when ejected ink droplets remain on the nozzle surface or foreign matter adheres to the nozzle surface, ink droplets may be ejected in the undesired direction or may become unable to be ejected, thereby seriously degrading the printing quality and image forming performance.
Furthermore, the speed of image forming processing has been increased in recent inkjet recording devices. To that end, throughputs improved by increasing the number of nozzles of the recording head so that more ink droplets can be ejected in a single scan. As a result, more ink droplets may be left behind on the nozzle surface and the remaining ink droplets are wiped off with a wiper blade. However, when the nozzle surface is wiped off by the wiper blade as described, there is a problem that the ink droplets wiped off from the nozzle surface and adhered to the wiper blade may be flicked off at the moment when the wiper blade is separated from the recording head after wiping the nozzle surface due to the elastic reaction of the wiper blade, thereby contaminating the inside of the printer body with the spattered ink droplets and degrading the printing quality.
To prevent the ink droplets adhered to the wiper blade from flicking off from the wiper blade, according to an inkjet recording device disclosed in the Patent Document 1 below, the wiper blade separates from the nozzle surface after passing the middle of the nozzle surface but before passing the end of the nozzle surface so that the wiper blade and the recording head are no longer in contact after the elastically deformed condition of the wiper blade is released.
Further, according to an inkjet recording device disclosed in the Patent Document 2 below, when the ink droplets left behind on the nozzle surface of the recording head are wiped with a wiper blade capable of moving in the direction vertical to the height direction of the nozzle surface of the recording head, a carriage on which the recording head is mounted while performing a round-trip scanning movement is stopped in the middle of wiping operations while the wiper blade is bent. Then the wiper blade is moved to wipe the remaining nozzle surface while the wiper blade is gradually being lowered so as to reduce the elastic deformation of the wiper bade, thereby reducing the amount of flicked ink droplets.
According to an inkjet recording device disclosed in the Patent Document 3 below, the wiper member for wiping off the nozzle surface of a recording head includes an ink absorbing section having elastic and superior water-absorbing characteristics and a wiping section provided adjacent to the ink absorbing section, closer to the nozzle surface than the ink absorbing section, and having lower water-absorbing characteristics. As a result, the wiping section wipes the ink droplets and the paper dust on the nozzle surface and then the wiped ink droplets and the like are absorbed into the ink absorbing section, thereby preventing the ink droplets from scattering.
Further, according to an inkjet recording device disclosed in the Patent Document 4 below, there is provided an escape surface on the downstream side of the recording head (on the side where the wiper blade separates from the recording head) such that the height direction of the recording head vertical to the nozzle surface is gradually reduced as the wiper blade approaches the end of the downstream side of the recording head. Because of this structure, when the wiper blade wiping the nozzle surface proceeds to wipe the escape surface, the elastic deformation of the wiper blade is gradually reduced, thereby preventing the remaining ink droplets on the header of the wiper blade from flicking off caused by the reaction force due to suddenly eliminating the elastic deformation of the wiper blade.
Patent Document 1: Japanese Patent Publication No: 3234087
Patent Document 2: Japanese Patent Application Publication No: 2006-192693
Patent Document 3: Japanese Patent Application Publication No: 2003-1833
Patent Document 4: Japanese Patent Application Publication No: 2002-79680
However, when the wiper blade separates from the nozzle surface after passing the middle of the nozzle surface but before passing the end of the nozzle surface as described in the Patent Document 1, or when the wiper blade gradually recedes from the nozzle surface during the wiping operations as described in the Patent Document 2, the portion between the middle to the end of the nozzle surface cannot be sufficiently wiped due to insufficient contacting pressure exerted by the wiper blade. As a result, the nozzle surface cannot be cleaned sufficiently and, disadvantageously, the ink droplets remaining on the nozzle surface due to the insufficient cleaning may contaminate recording paper.
Further, even when the wiper blade is arranged so that the wiping section having lower water-absorbing characteristics wipes the ink droplets and the paper dust on the nozzle surface, and then the wiped ink droplets and the like are absorbed into the ink absorbing section having superior water-absorbing characteristics as described in the Patent Document 3, the ink droplets may not be sufficiently absorbed into the ink absorbing section in a case where the paper dust adheres to the surface of the ink absorbing section.
Still further, the ink absorbing section is usually formed of an interconnected porous material so as to have water-absorbing characteristics. Since the holes of the porous material are likely to be sealed with a material such as the pigment of ink, the ink absorbing section may not stably absorb ink droplets for the long term. As a result, unfortunately, the scattering of ink droplets cannot be sufficiently prevented.
Further, since the wiper member includes an ink absorbing section having elastic and superior water-absorbing characteristics and a wiping section having lower water-absorbing characteristics, the structure of the wiper member is complicated, thereby complicating the forming process and increasing the cost of the wiper member.
Further, since the escape surface is formed on the downstream side of the nozzle surface to be wiped with the wiper blade as described in the Patent Document 4, the wiper blade cannot contact the escape surface with sufficient contact pressure. As a result, more ink droplets are likely to be left behind on the escape surface. In addition, if the left ink droplets are accumulated on the escape surface, the accumulated ink droplets may contaminate recording paper.
In an aspect of this disclosure, there is provided an inkjet recording device capable of wiping the nozzle surface to the end of the nozzle surface with sufficient contact pressure so as to wipe off the remaining ink droplets on the nozzle surface, thereby preventing the wiped ink droplets from scattering to stably form good quality images.
According to another aspect, there is provide an inkjet recording device including a recording head ejecting ink droplets to record a character and an image onto a recording medium, a carriage with the recording head mounted thereon performing a round-trip scanning movement, a wiping unit, and a blade elevating unit disposed within a scanning range of the carriage and moving the wiping unit upward and downward in the height direction of the nozzle surface of the recording head. The wiping unit includes a wiper blade made of an elastic body and formed in a flat plate shape for wiping a nozzle surface of the recording head, and a reaction force eliminating member reducing a reaction force of the wiper blade generated when a wiping operations of the wiper blade is terminated.
According to another aspect, the reaction force eliminating member has a spring characteristic, is made of a material having a Young's modulus higher than that of the wiper blade, and has a flat plate shape.
According to still another aspect, a supporting unit supports the wiper blade and the reaction force eliminating member has convex parts provided one on each upper end part thereof, the convex parts face the wiper blade, and the wiper blade and the reaction force eliminating member stand substantially upright on the supporting unit.
According to still another aspect, the supporting unit is removably attached to the blade elevating unit.
According to another aspect, the header of the wiper blade wipes the nozzle surface of the recording head to wipe off the ink droplets and the like on the nozzle surface. When the header of the nozzle surface separates from the nozzle surface, the reacting force eliminating member absorbs the reaction force of the wiper blade so that the bent wiper blade is restored to its upright original position. As a result, the reaction force that would be otherwise generated by suddenly restoring the bent blade can be controlled, the scattering of the ink droplets and the foreign matter on the header of the wiper blade can be effectively prevented, and the contamination inside the inkjet recording device can be avoided accordingly.
Further, the reaction force generated when the bent wiper blade is restored can be stably absorbed when the reaction force elimination member is formed so as to have a spring characteristic, made of a material having a Young's modulus higher than that of the wiper blade, and has a flat plate shape.
Further, convex parts are provided one each on surfaces of the upper portion of the reaction force eliminating member such that the convex parts face the wiper blade. Then the supporting unit supports the reaction force eliminating member and the wiper blade so that the reaction force eliminating member and the wiper blade stand upright to secure the position accuracy of the wiper blade and the reaction force eliminating member, thereby enabling the secure absorption of the reaction force when the bent wiper blade is restored.
Further, the wiper blade can be easily replaced when the supporting unit is provided so as to be attached to and detached from the blade elevating unit.
In addition, in the carriage 13, there are sub tanks 15 that are fluid containers for supplying each ink to the corresponding recording head 14. Each ink is supplied from the corresponding ink cartridge 9 to the corresponding sub tank 15 via the corresponding ink supply tube 16. The ink cartridges 9 store the corresponding inks of yellow (Y), cyan (C), magenta (M), and black (B) as the color components of the inkjet recording device. The sub tanks 15 supply the ink to the recording heads 14 and the ink cartridges 9 supply the ink to the sub tanks 15. The sub tanks 15 and the ink cartridges 9 constitute an ink supplying device.
In the inkjet recording device, there is a paper feeding section for feeding the recording papers 18 accumulated on the paper accumulating section (thick plate) 17 of the paper feeding tray 2. The paper feeding section includes a half-moon roller (paper feeding roller) 19 and a separation pad 20. The half-moon roller (paper feeding roller) 19 separates and feeds one sheet of recording papers 18 at a time from the paper accumulating section 17. The separation pad 20 faces the paper feeding roller 19. The separation pad 20 is pressed toward the side of the paper feeding roller 19.
Further, in the inkjet recording device, there is a feeding section for feeding the recording papers 18 from the paper feeding tray 2 to a position below the recording heads 14 through a guide 21. The feeding section includes a conveying belt 22, a counter roller 23, a conveying guide 24, a pressing member 25, a head pressure roller 26, a charge roller 27, a conveying roller 28, a tension roller 29, and a guide member 30. The conveying belt 22 electrostatically attracts and conveys the recording paper 18. The counter roller 23 sandwiches the recording paper 18 from the paper feeding section through the guide 21 with the conveying belt 22 to convey the sandwiched recording paper 18. The conveying guide 24 changes the feeding direction of the recording paper 18 fed substantially vertically upward by substantially 90 degrees so that the recording paper 18 is placed on the conveying belt 22. The head pressure roller 26 is pressed toward the conveying belt 22 by the pressing member 25. The charge roller 27 is a charging unit for charging the surface of the conveying belt 22. Herein, the conveying belt 22 is an endless belt suspended between the conveying roller 28 and the tension roller 29 so as to rotate in the belt conveying direction as shown in
At the rear side of the conveying belt 22, there is the guide member 30 disposed corresponding to the printing area defined by the recording heads 14. The upper surface of the guide member 30 protrudes to the side of the recording heads 14 beyond the upper tangent line between the conveying roller 28 and the tension roller 29 each roller supporting the conveying belt 22. Because of this structure, the conveying belt 22 is pressed upward and guided by the upper surface of the guide member 30, thereby maintaining the high-precision flatness of the conveying belt 22.
Further, in the inkjet recording device, there is a discharging section for discharging the recording paper 18 recorded on by the recording heads 14. The discharging section includes a separating click 31 and paper discharging rollers 32 and 33. The separating click 31 separates the recording paper 18 from the conveying belt 22. The paper discharging tray 3 is disposed below the paper discharging roller 32. The position between the paper discharging rollers 32 and 33 is set higher to some extent than the paper discharging tray 3 so that as many recording papers 18 as possible can be stored in the paper discharging tray 3.
Further, a double-sided paper feeding unit 34 is removably attached to the rear side of the device main body 1. The double-sided paper feeding unit 24 receives the recording paper 18 returned by the reverse rotation of the conveying belt 22, turns the recording paper 18 over, and feeds the recording paper 18 to a position between the counter roller 28 and the conveying belt 22 again. On the double-sided paper feeding unit 34, there is a manual paper feeding unit 35.
Further, as shown in
As shown in
The wiping unit 41 includes a wiper blade 43, a reaction force eliminating member 44, a supporting member 45, and a blade elevating mechanical section 46. The wiper blade 43 is made of an elastic material such a rubber elastic material and formed in a tabular shape as shown in
As shown in
To configure the wiping unit 40, first, the axle cam 55 of the blade elevating mechanical section 46 is positioned so that the cut-out section 57 of the plate cam 54 is positioned at the top of the plate cam 54. Next, the guide rollers 53 of the supporting member 45 with the wiper blade 43 and the reaction force eliminating member 44 attached to the supporting member 45 are inserted into the guide grooves 53. Then, the boss 51 for elevating the supporting member 54 is inserted into the cut-out section 54 so that the boss 51 is engaged into the cam groove 56. In this manner, the supporting member 45 is attached to the blade elevating mechanical section 46 to configure the wiping unit 40. According to this mechanism where the supporting member 45 with the wiper blade 43 and the reaction force eliminating member 44 fixed to the supporting member 45 is attached to the blade elevating mechanical section 46, the wiper blade 43 and the reaction force eliminating member 44 are raised and lowered according to the movement of the supporting member 45 up and down by rotating the axle cam 55 so as to move the boss 51 upward and downward along the cam groove 56 of the plate cam 54.
The operation of wiping off the ink droplets and foreign matter attached to the nozzle surface of the recording heads 14 using the wiper blade 43 being moved upward and downward by the blade elevating mechanical section 46 is described with reference to
When the recording heads 14 moving at a constant speed of the carriage 13 approach the maintaining and restoring mechanical section 36, the supporting member 45 with the wiper blade 43 and the reaction force eliminating member 44 fixed to the supporting member 45 is raised by rotating the axle cam 55 of the blade elevating mechanical section 46 to the position where the reaction force eliminating member 44 does not contact the nozzle surface but the header portion of the wiper blade 43 protrudes by a prescribed length beyond the nozzle surface 141 of the recording heads 14 as shown in
When the recording heads 14 passed beyond the maintaining and restoring mechanical section 36, the supporting member 45 with the wiper blade 43 and reaction force eliminating member 44 fixed to the supporting member 45 is lifted down to a prescribed position by rotating the axle cam 55 of the blade elevating mechanical section 46.
To remove and replace the wiper blade 43 of the maintaining and restoring mechanical section 36, the axle cam 55 of the blade elevating mechanical section 46 is rotated so that the cut-out section 57 of the plate cam 54 is positioned at the boss 51 for elevating the supporting member 45 and the supporting member 45 is pulled out of the blade elevating mechanical section 46. Then the wiper blade 43 and the reaction force eliminating member 44 are removed from the supporting member 45 and replaced by a new wiper blade 43 and a new reaction force eliminating member 44. In this manner, wiper blade 43 can be replaced easily and the maintenance operation can be performed easily.
The present invention is not limited to the above-mentioned embodiments, and variations and modifications may be made without departing from the scope of the present invention.
The present application is based on and claims the benefit of priority of Japanese Patent Application No. 2007-059388, filed on Mar. 9, 2007 the entire contents of which are hereby incorporated by reference.
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