Patent Grant
7918531
The present application is based on Japanese Patent Application No. 2005-016987 filed on Jan. 25, 2005, the contents of which are incorporated herein by reference.
1. Field of the Invention
The present invention relates in general to an ink-jet recording apparatus including a recording head which is moved in a predetermined direction for performing recording of images, characters and the like on a recording medium by ejecting inks having mutually different colors from corresponding nozzles. The present invention also relates to a method of cleaning the recording head of the ink-jet recording apparatus.
2. Discussion of Related Art
As an ink-jet recording apparatus which performs recording of images, characters and the like on a recording medium by ejecting inks based on input signals, there is conventionally known one which introduces the inks into the actuator of a recording head and ejects the inks pressurized by utilizing deflection or flexure of piezoelectric elements, electrostrictive elements and so on caused based on the input signals or utilizing local or partial boiling of the inks by heat-generating elements.
In general, the ink-jet recording apparatus is subjected to a recording operation in factories prior to shipment thereof for the purpose of confirming or checking ink ejecting performance of the apparatus. In the recording operation, the ink tanks are actually installed on the apparatus for supplying the inks therefrom to the recording head 90 to perform the recording operation of recording test patterns, for instance. For shipment of the apparatus after the checking of the recording operation, the ink tanks are removed from tubes for supplying the inks from the ink tanks to the recording head 90, and the openings of the ink tanks and the tubes are respectively sealed by caps or the like. Further, there is attached a cap 96 to the recording head 90 for preventing contamination due to leakage of the inks and drying of the inks in the nozzles 91 during transportation, storage, etc., of the apparatus. The cap 96 is for removing air bubbles and foreign substances from the recording head 90. As shown in
After shipment of the ink-jet recording apparatus in the state described above, the inks may leak out of the ink ejection openings of the nozzles 91 of the recording head 90 influenced by changes in the temperature and atmospheric pressure, vibration, etc., in the transportation or storage period of the apparatus before a user who has purchased the apparatus initially uses the apparatus. For instance, when the ink tanks are removed from the tubes and the caps are attached to respective ends of the tubes after checking of the ink ejecting performance as described above, the air tends to enter the tubes from the respective ends thereof and stay therein. In the meantime, because valves provided in ink passages from the ends of the tubes to the recording head 90 and a valve of the suction pump connected to the cap 96 are kept open, the inks may leak from the nozzles 91 of the recording head 90 and be drawn into the same 91 when the volume of the staying air varies due to changes in the temperature and atmospheric pressure. The inks which leak from the nozzles 91 gather or collect around the ink ejection openings of the nozzles 91 and mix with one another in the vicinity of the ink ejection openings of the adjacent nozzles 91, so that the mixed ink I enters insides of the nozzles 91 from the ink ejection openings thereof due to the change in the volume of the staying air, the surface tension, etc. Consequently, the insides of the nozzles 91, the manifolds 92, and the buffer tanks 94 may be contaminated with the mixed ink I.
In a case where the recording head 90 performs the recording operation with the nozzles 91 and so on contaminated with the mixed ink I, the mixed ink I is ejected from the nozzles 91 on a recording sheet, so that the recording operation is performed with the inks whose colors are different from original ones. To prevent this, JP-A-59-209877, for instance, discloses the following technique: The above-mentioned ink sucking action called purging by the cap 96 is performed for sucking the mixed ink I from the nozzles 91 and drawing new fresh inks from the ink tanks. Further, the mixed ink I is removed from the nozzles 91 and the manifolds 92 by so-called flushing, i.e., ejecting the inks from the nozzles 91 toward a waste-ink tray.
In the ink flow within the recording head 90, while the nozzles 91 and throttles not shown mainly cause resistance to the ink flow, the wall of each manifold 92 also causes the resistance to the ink flow. Described more specifically, in the manifold chamber 93 of each manifold 92, the resistance to the ink flow is small at its upstream portion connected to the ink supply path 95 and the resistance to the ink flow is large at its downstream portion remote from the ink supply path 95. Accordingly, in the above-mentioned ink sucking action, the ink flows fast at the upstream portion of the manifold chamber 93 and the ink flows slowly at the downstream portion of the same 93. Therefore, the new fresh ink is likely to be supplied to the upstream portion of the manifold chamber 93 so that the mixed ink is readily replaced with the new fresh ink whereas the mixed ink is not likely to be replaced with the new fresh ink at the downstream portion of the manifold chamber 93.
Further, where each manifold chamber 93 is constituted, as shown in
The mixed ink I which is difficult to be removed by the sucking action is removed by flushing, i.e., ejecting the mixed ink I from the nozzles 91. For completely removing the mixed ink I, however, the ink is inevitably ejected from each of the nozzles 91 from which the mixed ink I can be removed by the sucking action. Namely, the ink is inevitably ejected from each nozzle 91 for which the removal of the mixed ink I by flushing need not be conducted. Accordingly, the total ink amount consumed by flushing undesirably becomes much larger than the minimum ink amount required for removing the mixed ink I.
Incidentally, when the ink-jet recording apparatus described above is transported by shipping or the like for exporting abroad, for instance, a plurality of the ink-jet apparatus each packed in a cardboard box together with cushioning materials are stacked on a palette. When considering a load to be applied to the apparatus located at the bottom part of the stack on the palette, there is inevitably an upper limit in the number of the apparatus that can be stacked on the palette. To enhance the carrying or loading efficiency in the transportation, if the ink-jet recording apparatus of wide and slim type is packed with its front or rear facing downward, it is possible to reduce the floor space when the packed apparatus are stacked on the palette. Thus, the loading efficiency can be enhanced.
In a case where the ink-jet apparatus is packed as mentioned above, the recording head 90 wherein the ink ejection openings of the nozzles 91 are formed in its nozzle surface which is to face downward in the recording operation for ejecting the ink droplets downwardly in the recording operation assumes, upon packing, a posture in which the ink ejection openings of the nozzles 91 face sideways and the rows of the nozzles extend in the vertical direction. With the recording head 90 kept in the posture, the inks which leak from the nozzles 91 drop therefrom and mix with each other in the cap 96. In this case, too, the thus mixed ink I enters the insides of the nozzles 91 from the ink ejection openings thereof. Further, because the nozzles 91 face sideways, namely, extend horizontally, the mixed ink I which have flowed into the nozzles 91 tend to diffuse into the buffer tanks 94, thereby contaminating the buffer tanks 94. As the contamination by the mixed ink I spreads in the recording head 90, the ink amount to be consumed by purging and flushing for removing the mixed ink I undesirably increases.
It is therefore an object of the present invention to provide an ink-jet recording apparatus and a method of cleaning a recording head of an ink-jet recording apparatus, which apparatus and method are capable of completely removing, with a reduced ink consumption amount upon initial working of the apparatus, a mixed ink entered nozzles, ink chambers and buffer tanks during transportation, storage, and so on before the initial working.
The inventor of the present invention has made an extensive study on diffusion region of the mixed ink within the recording head, the resistance to the ink flow in the recording head, the transportation and storage conditions, and so on. As a result of the study, the inventor has developed a technique of reliably removing, with a reduced ink consumption amount upon initial working of the ink-jet recording apparatus, the mixed ink entered the recording head during transportation, storage, and so on, thereby preventing contamination due to the mixed ink.
To achieve the above-indicated object of the present invention, the invention provides an ink-jet recording apparatus, comprising: a recording head including a plurality of ink chambers each provided for each of plurality of inks of mutually different colors and a plurality of nozzles each of which communicates with either of the ink chambers, the recording head performing recording by ejecting, from each of the nozzles, a corresponding one of the inks which corresponds to said each of the nozzles; an ink suction device including a cap arranged to fluid-tightly cover a nozzle surface of the recording head in which the nozzles are formed, the ink suction device sucking the inks from the nozzles utilizing the cap; and a control device for controlling the ink-jet recording apparatus, the control device including an initial-cleaning-operation executing portion which executes, upon initial working of the ink-jet recording apparatus, an initial cleaning operation including: controlling the ink suction device to execute an initial ink sucking action wherein the inks are sucked from the nozzles; and controlling the recording head to execute (a) an all-nozzle-ink-ejecting action for all of the nozzles to eject the corresponding one of the inks from each of all of the nozzles at a plurality of shots and (b) a partial-nozzle-ink-ejecting action for at least one specific nozzle among the plurality of nozzles to eject the corresponding one of the inks from each of the at least one specific nozzle at a plurality of shots.
Here, “initial working” of the ink-jet recording apparatus means that the ink-jet recording apparatus is initially used by a user after its manufacture or a quality inspection conducted thereon. Upon the initial working of the apparatus, the initial-cleaning-operation executing portion of the control device controls the ink sucking device to execute the initial ink sucking action in which the inks in the respective ink chambers are sucked from the corresponding nozzles of the recording head, whereby the mixed ink entered the nozzles and the ink chambers during transportation, storage, etc., of the apparatus before the initial working can be removed by sucking. Further, the initial-cleaning-operation executing portion controls the recording head to execute, as an initial ink ejecting action, the all-nozzle-ink-ejecting action and the partial-nozzle-ink-ejecting action. Described in detail, by execution of the all-nozzle-ink-ejecting action for all of the nozzles to eject corresponding one of the inks from each of all of the nozzles at a plurality of shots, the mixed ink remaining in the nozzles, etc., after the initial ink sucking action is ejected. Further, by execution of the partial-ink-ejecting action for the at least one specific nozzle to eject the corresponding one of the inks from each of the at least one specific nozzle at a plurality of shots, the mixed ink remaining in each of the at least one specific nozzle can be removed therefrom while reducing the entire ink consumption amount because the other inks corresponding to the nozzles other than the at least one specific nozzle are not ejected in the partial-nozzle-ink-ejecting action.
To achieve the above-indicated object of the present invention, the invention also provides a method of cleaning a recording head of an ink-jet recording apparatus upon initial working thereof, the recording head including: a plurality of ink chambers each provided for each of plurality of inks of mutually different colors; and a plurality of nozzles each of which communicates with either of the ink chambers, the recording head performing recording by ejecting, from each of the nozzles, a corresponding one of the inks which corresponds to said each of the nozzles, the method comprising: sucking the inks from the nozzles; ejecting the corresponding one of the inks from each of all of the nozzles at a plurality of shots; and ejecting the corresponding one of the inks from each of at least one specific nozzle among the plurality of nozzles at a plurality of shots.
The present method described above enjoys effects similar to those described with respect to the above-indicated ink-jet recording apparatus.
The above and other objects, features, advantages and technical and industrial significance of the present invention will be better understood by reading a following detailed description of preferred embodiments of the invention, when considered in connection with the accompanying drawings, in which:
Referring to the drawings, there will be explained a composite machine 1 (an ink-jet recording apparatus) according to a first embodiment of the present invention. As shown in
Where the ink-jet recording apparatus of the invention is used in the form of a composite machine, the composite machine, may be a small-size machine shown in
As shown in
The scanning portion 3 positioned at the upper part of the composite machine 1 is constituted as a so-called flat-bed scanner. As shown in
On a front side of the upper part of the composite machine 1, there is provided an operation panel 4 for controlling operations of the printing portion 2 and the scanning portion 3. The operation panel 4 is constituted by including various control buttons and keys, a liquid crystal display, etc. The composite machine 1 is arranged to be operated in accordance with commands inputted through the operation panel 4 and commands transmitted, via a printer driver, from the computer connected thereto. For instance, at an upper left portion on the front side of the composite machine 1, there is provided a slot 5 into which is insertable a small-size memory card of various types as the memory device. The image data recorded in the small-size memory card which is inserted in the slot 5 is read out therefrom so as to be displayed on the crystal liquid display portion, and there is made an input, through the operation panel 4, that permits the printing portion 2 to record an arbitrary image on the recording sheet.
By referring next to
As shown in
The roller support arm 26 is pivotable at its proximal end upward and downward. In a standby condition, the roller support arm 26 is lifted upward as shown in
The sheet-feed path 23 is constituted by an outer guide surface and an inner guide surface facing each other with a predetermined distance interposed therebetween, except a portion thereof where the image recording portion 24 is disposed. For instance, on the rear side of the composite machine 1, the sheet-feed path 23 is constituted by the outer guide surface formed integrally with the frame of the composite machine 1 and the inner guide surface given by a guide member 28 fixed to the frame. At portions of the sheet-feed path 23 where the path 23 is curved, there are provided rolling bodies 29 such as rollers, such that each rolling body 29 is rotatable about its axis that coincides with the width direction of the sheet-deed path 23, with its roller surface exposed to the outer guide surface or the inner guide surface. The rolling bodies 29 assure smooth feeding of the recording sheet contacting the guide surfaces at portions of the sheet-feed path 23 where the path 23 is curved.
As shown in
Described more specifically referring to
The platen 41 is disposed under the sheet-feed path 23 and at a central portion of the image recording portion 24 as seen in the moving direction of the recording head 40 in which the recording sheet passes. At one and the other of the opposite sides of the central portion of the image recording portion 24 where the recording sheet does not pass, namely, outside a recording range W1 by the recording head 40, there are provided a purge mechanism 47 as the ink sucking device (at the right side in
The purge mechanism 47 includes: a cap 49 for covering a nozzle surface of the recording head 40 in which nozzles 50 are formed; a pump mechanism (not shown in
The cap 49 includes: a first cap portion 49a for fluid-tightly covering ink-ejection nozzles 50a of the nozzles 50 from which is ejected the black (K) ink; and a second cap portion 49b for fluid-tightly covering ink-ejection openings 50a of the nozzles 50 from which are ejected color inks, i.e., the cyan (C) ink, the magenta (M) ink and the yellow (Y) ink. Thus, the black ink and the color inks are prevented from mixing in the cap 49 when the cap 49 sucks the inks while fluid-tightly covering the nozzle surface of the recording head 40.
Although the pump mechanism and the moving mechanism of the purge mechanism 47 are not described in detail, there may be employed as the pump mechanism a system in which flexible tubes are successively compressed and squeezed by rollers and the like for flowing the air in the tubes, or other known pump mechanisms, and there may be employed as the moving mechanism any known mechanisms. The waste ink tray 48 is open upward corresponding to the nozzle surface of the recording head 40 for receiving and storing the inks to be ejected from the recording head 40 upon flushing which is not an actual printing operation performed on the recording sheet.
As shown in
As shown in
Each manifold chamber 53 is defined by a lower wall surface in which are formed the nozzles 50 of the corresponding group and an upper wall surface confronting the lower surface. The upper wall surface is inclined such that a distance between the upper wall surface and the lower wall surface gradually decreases in a direction away from the corresponding ink supply path 52 toward a downstream end portion of the manifold chamber 53 as seen in a direction of the flow of the ink. Accordingly, the manifold chamber 53 has a cross sectional area that gradually decreases in the direction away from the ink supply path 52 toward the downstream end portion thereof. As a mechanism of ejecting, from the ink ejection openings 50a as ink droplets, the ink distributed into the nozzles 50 via the corresponding manifold 51, there may be employed one in which each nozzle 50 is defined by side walls made of a piezoelectric material and the ink droplets are ejected by deformation of the side walls made of the piezoelectric material, for instance. Any other known mechanism may be similarly employed.
Above the manifolds 51, there are disposed buffer tanks 54 which are provided for the respective inks of the four different colors (C, M, Y and K), like the nozzles 50 of the four groups and the manifolds 51. The inks of the four different colors are fed from the respective ink tanks not shown in
The buffer tanks 54 communicate with the respective manifold chambers 53 through the respective ink supply paths 52. Accordingly, there is formed an ink supply route in which the inks supplied from the respective ink tanks are fed to the nozzles 50 of the corresponding groups via the corresponding buffer tanks 54 and manifolds 51. Thus, the recording head 40 is arranged to eject the inks of the four different colors (C, M, Y and K) as ink droplets from the corresponding ink ejection openings 50a.
As shown in
The press roller 56 is rotatably disposed while being biased toward the drive roller 55 with a suitable pressing force. Upon entering of the recording sheet between the drive roller 55 and the press roller 56, the press roller 56 is retracted from the drive roller 55 by an amount corresponding to the thickness of the recording sheet and cooperates with the drive roller 55 to hold the recording sheet therebetween, so that the rotary force of the drive roller 55 can be surely transmitted to the recording sheet. Though the spur roller 58 functions in a way similar to the press roller 56, the spur roller 58 has a rough surface with convexity and concavity for preventing deterioration of the images recorded on the recording sheet since the spur roller 58 contacts the recording sheet on which the images have been recorded.
The recording sheet held by and between the drive roller 55 and the press roller 56 is intermittently fed on the platen 41 at a suitable line feed pitch. The recording head 40 is moved during line feed movements, thereby recording images on the recording sheet starting from its leading end portion. The leading end portion of the recording sheet on which the images have been recorded is then held by and between the sheet-discharge roller 57 and the spur roller 58. Accordingly, the recording sheet is held by the sheet-discharge roller 57 and the spur roller 58 at its leading end portion and by the drive roller 55 and the press roller 56 at its trailing end portion. In this state, the recording sheet is intermittently fed at the suitable line feed pitch for recording performed by the recording head 40. As the recording sheet is further fed, the trailing end portion of the recording sheet passes through the drive roller 55 and the press roller 56 so as to be released from the two rollers 55, 56, and the recording sheet is fed by the sheet-discharge roller 57 and the spur roller 58 at the suitable line feed pitch for recording performed by the recording head 40. After the images have been recorded in a prescribed range of the recording sheet, the sheet-discharge roller 57 is continuously rotated, whereby the recording sheet held by the sheet-discharge roller 57 and the spur roller 58 is discharged to the sheet-discharge tray 21.
The central processing portion 60 performs, in accordance with information of various sensors, the control of rotation of an LF motor 63 for driving the drive roller 55 and a CR motor 64 for moving the recording head 40, the control of the purge mechanism 47, the scanning portion 3 and so on. As shown in
As mentioned above, the present composite machine 1 can perform recording of images and characters on the recording sheets on the basis of image data and character data transmitted from the computer (PC) 65 connected thereto, as well as on the basis of input made through the operation panel 4. For this end, there is provided an interface (I/F) for data communication with the computer 65. While one example of the structure of the control portion 6 is described, it is to be understood that the structure of the control portion 6 is not limited to that of the present embodiment.
As shown in
The waste ink tray 48 is for receiving the inks ejected from the recording head 40 in so-called flushing. In operation, the recording head 40 is moved to the left-side end of the head-moving region W2 (as seen in
In general, the composite machine 1 has been subjected to a recording operation performed in factories prior to shipping thereof for checking the ink ejecting performance of the composite machine 1. In the recording operation, the ink tanks are actually installed and test patterns or the like are recorded. Accordingly, the inks are filled in the nozzles 50, the manifolds 51 and the buffer tanks 54 of the recording head 40. The composite machine 1 is shipped with the recording head 40 covered with the cap 49 for preventing contamination due to ink leakage and drying of the inks in the nozzles 50.
The ink which has leaked from the ink ejection openings 50a of the corresponding nozzles 50 during transportation or storage after shipment gather or collect around the ink ejection openings 50a and mix with another ink which has similarly leaked from the adjacent ink ejection openings 50a, so that the mixed ink enters insides of the nozzles 91 from the ink ejection openings 50a thereof. The mixed ink entered the nozzles 50 may be diffused into the buffer tanks 54. To avoid the contamination with the mixed ink during the transportation period or the storage period, there are conducted an initial ink sucking action and an initial ink ejecting action upon initial working of the composite machine 1, namely, upon initial use of the composite machine 1 by a user after the manufacture thereof or the quality inspection conducted thereon through the transportation period or the storage period.
Hereinafter, by referring to the flow chart of
The flow chart of
When it is judged that the power is initially turned on, namely, the composite machine 1 is about to be subjected to the initial working, the cleaning operation of cleaning the recording head 40 (hereinafter may be referred to as “head cleaning operation”) is performed by executing the initial ink sucking action and the initial ink ejecting action. When it is judged that the power is not initially turned on, the composite machine 1 is placed into a wait state for performing recording (S8). Accordingly, when the turning on of the power is not initial one, the composite machine 1 is ready to perform recording without executing the cleaning operation of the recording head 40.
The head cleaning operation does not start at the same time when the power is turned on. Where the composite machine 1 is connected to the computer, for instance, an electric signal indicative of the initial working of the composite machine 1 is transmitted from the same 1 to the computer, whereby an indication is made on a display of the computer by a software such as a printer driver installed on the computer, which indication encourages execution of the head cleaning operation by the initial ink sucking action and the initial ink ejecting action. When the user acknowledges the execution of the head cleaning operation by clicking “OK” on the display, for instance, the computer sends the control portion 6 an electric signal indicative of the initiation of the head cleaning operation. In response to the electric signal, the control portion 6 starts execution of the head cleaning operation. During the head cleaning operation, there is suitably made, on the display, an indication which indicates that the head cleaning operation is now in progress or an indication which indicates a state of progress of the head cleaning operation. Thus, the head cleaning operation is not initiated at the same time when the power is initially turned on. Instead, the user first recognizes the execution of the head cleaning operation and the head cleaning operation is then executed after acknowledgement by the user, so that the user is allowed to make preparations necessary for the head cleaning operation such as releasing of fixation of the recording head 40, connecting of ink cartridges. The settings such as indication on the display by the software such as the printer driver are design matters and are suitably determined by considering the operating environment of the composite machine 1, etc. In the present embodiment, the display of the computer functions as a display device and the input members such as a mouse and a keyboard of the computer function as an input device. The head cleaning operation may be performed only by the composite device 1 without being connected to the computer, using the liquid crystal display portion and the control keys of the operation panel 4 as the display device and the input device, respectively.
As the head cleaning operation performed upon the initial working of the composite machine 1, the purge mechanism 47 executes the initial ink sucking action (S2) in which the inks in the manifold chambers 53 and the buffer tanks 54 are sucked through the nozzles 50. Described in detail with reference to
The ink sucking action is carried out in the following manner: Initially, the ink sucking action is performed by the pump in the first cap portion 49a which covers the black-ink ejection openings 50a for ejecting the black ink, so that a predetermined amount of the black ink is sucked through the corresponding nozzles 50 from the corresponding manifold chamber 53 and buffer tank 54 which are filled with the black ink. Thereafter, the ink sucking action is performed by the pump in the second cap portion 49b which covers other ink ejection openings 50a except the black-ink ejection openings 50a, which other ink ejection openings 50a are for ejecting the color inks C, M and Y. As a result, a predetermined amount of each of the color inks C, M and Y is sucked through the corresponding nozzles 50 from the corresponding manifold chamber 53 and buffer tank 54 which are filled with the corresponding color ink. By sucking the color inks C, M and Y at one time as described above, the ink sucking action can be promptly performed.
The suction of the black ink and the suction of the color inks C, M and Y are performed independently of each other for the purpose of preventing mixing of the black ink and the color inks C, M and Y within the cap 49. Where there is a little fear of mixing, the suction of the black ink and the suction of the color inks C, M and Y may be performed concurrently. Further, the suction of the black ink and the suction of the color inks C, M and Y may be alternately performed. Moreover, the initial ink sucking action may be constituted by suitably combining the independent suction and the concurrent suction. Namely, the initial ink sucking action is not limited to that according to the present embodiment. By performing the initial ink sucking action described above, the mixed ink entered the manifold chambers 53 and the buffer tanks 54 through the nozzles 50 during the transportation period or the storage period can be removed by sucking.
After the initial ink sucking action, the all-nozzle-ink-ejecting action (S3) is executed for all nozzles 50 to eject a corresponding one of the inks (C, M, Y and K) from each of all nozzles 50. Described in detail with reference to
The amount of the ink droplet for each shot and the number of total shots in the all-nozzle-ink-ejecting action are determined by taking into account an amount which is normally required to discharge the mixed ink. Since the partial-nozzle-ink-ejecting action (that will be explained later) is subsequently executed, the amount to be ejected in the all-nozzle-ink-ejecting action need not be equal to the amount required for completely discharging the mixed ink from all manifold chambers 53 and all nozzles 50. Therefore, in the all-nozzle-ink-ejecting action, the ink ejection of 48000 shots is performed with an amount of the ink droplet for each shot from each nozzle 50 being set at 35 pl, for instance.
Where the ink ejection of a prescribed number of shots is executed in the all-nozzle-ink-ejecting action, the total shots may be suitably divided into a plural sets and the ink ejection with each set of shots may be repeatedly executed with a prescribed time interval between any two successive executions of the ink ejection with each set of shots. When the ink ejection from the nozzles 50 of the recording head 40 is continuously executed, the air bubbles generated in each ink undesirably grow, thereby causing ink ejection failure from the nozzles 50. Where the ink ejection is executed as described above, however, it is possible to inhibit the growth of the air bubbles in each ink due to the continuous ink ejection. In this connection, the number of shots in each set is desirably made equal to a maximum number of shots with which one ink is ejected from one nozzle per unit amount of the movement of the recording head 40, from the standpoint of easiness of control. The time interval during which the ink ejection is not executed is about several tens of fractions of a second. Accordingly, where the all-nozzle-ink-ejecting action of 48000 shots is executed with the amount of the ink droplet for each shot from each nozzle 50 being set at 35 pl as described above, the ink ejection is executed 12 times if the maximum number of shots with which one ink is ejected from one nozzle per unit amount of the movement of the recording head 40 is equal to 4000. Further, the above-mentioned time interval may conform to a line feed time of the recording head 40.
After the all-nozzle-ink-ejecting action, the partial-nozzle-ink-ejecting action (S4) is executed for at least one specific nozzle to eject a corresponding one of the inks from each specific nozzle at a plurality of shots. The at least one specific nozzle is one from which the corresponding ink is less likely to be sucked in the initial ink sucking action described above. For instance, in the present embodiment, the at least one specific nozzle includes nozzles that communicate with an end portion of each manifold chamber 53, which end portion is remote from a corresponding ink inlet 52a through which the corresponding ink is supplied from the corresponding buffer tank 54. The end portion may be interpreted as including an endmost portion of each manifold chamber 53 and its vicinity.
More specifically explained with reference to
In the present embodiment, therefore, the partial-nozzle-ink-ejecting action is executed for the nozzles 50 communicating with the downstream portion of each manifold chamber 53 remote from the corresponding ink inlet 52a, preferably, four nozzles 50T (
As in the above-mentioned all-nozzle-ink-ejecting action, in the partial-nozzle-ink-ejecting action, each ink is ejected at prescribed shots such that an amount of the ink droplet for each shot to be ejected from each specific nozzle 50T is set to be a predetermined amount. The amount of the ink droplet for each shot and the number of total shots in the partial-nozzle-ink-ejecting action are determined by taking into account the amount which is normally required to discharge the mixed ink. Since, in the partial-nozzle-ink-ejecting action, each ink is not ejected from the nozzles except the specific nozzles 50T communicating with the downstream portion of each manifold chamber 53, the entire ink consumption amount in the head cleaning operation conducted upon the initial working does not considerably increase even if each ink is ejected from the corresponding specific nozzles 50T in an amount sufficient for discharging the mixed ink. Therefore, in the partial-nozzle-ink-ejecting action, the ink ejection of 112000 shots is performed with an amount of the ink droplet for each shot from each specific nozzle 50T being set at 35 pl, for instance.
As in the above-mentioned all-nozzle-ink-ejecting action, in this initial-nozzle-ink-ejecting action, where the total shots are suitably divided into a plural sets and the ink ejection with each set of shots is repeatedly executed with a prescribed time interval between any two successive executions of the ink ejection with each set of shots, the growth of the air bubbles in each ink due to continuous execution of the ink ejection can be inhibited. In this connection, the number of shots in each set is desirably made equal to the maximum number of shots with which one ink is ejected from one nozzle per unit amount of the movement of the recording head 40, from the standpoint of easiness of control. Accordingly, where the partial-ink-ejecting action of 112000 shots is executed with the amount of the ink droplet for each shot from each specific nozzle 50T being set at 35 pl, the ink ejection is executed 28 times if the maximum number of shots with which one ink is ejected from one nozzle per unit amount of the movement of the recording head 40 is equal to 4000. Further, the above-mentioned time interval may conform to the line feed time of the recording head 40.
Upon termination of the partial-nozzle-ink-ejecting action, an electric signal indicative of the termination of the head cleaning operation is transmitted from the composite machine 1 to the computer, whereby an indication is made on the display of the computer by the software such as the printer driver, which indication indicates the termination of the head cleaning operation and which encourages execution of test recording. When the user acknowledges by clicking “OK” on the display, for instance, the computer sends the control portion 6 an electric signal indicative of the execution of the test recording. In response to the electric signal, the control portion 6 controls the recording head 40 to execute the test recording (S5). There may be employed, as test patterns to be used in the test recording, any suitable one conventionally used for color ink-jet recording apparatus and the like. Thus, the user first recognizes the execution of the test recording after the head cleaning operation and the test recording is then executed after acknowledgement by the user, so that the user is allowed to make preparations necessary for the test recording such as setting of the recording sheets. It is desirable to execute, if possible, the test recording, in order to judge the result of the head cleaning operation. However, the test recording may be omitted when the user judges that the execution of the test recording is not necessary. In this case, the composite machine 1 is placed into the wait state upon the termination of the head cleaning operation. As noted above, the indication which indicates the termination of the head cleaning operation and which encourages the test recording may be made on the liquid crystal display portion of the operation panel 4 of the composite machine 1, in place of the display of the computer. Similarly, the input for allowing the test recording may be made through the control buttons of the operation panel 4, in place of the input members. Where the test recording is executed by the composite machine 1 per se without being connected to the computer, the patterns for the test recording may be stored in advance in the ROM of the central processing portion 60, etc.
Upon termination of the test recording, an electric signal indicative of the termination of the test recording is transmitted from the composite machine 1 to the computer, whereby an indication is made on the display of the computer by the software such as the printer driver, which indication indicates the termination of the test recording. Through the indication, it is inputted whether the result of the test recording is good or bad (S6). The user checks the recording sheet on which the test recording has been performed and inputs, into the computer, the result of the test recording by clicking, for instance. Where there is made an input that the result of the test recording is bad, an indication is made on the display of the computer by the software, which indication encourages execution of an additional cleaning operation explained below. When the user acknowledges the execution of the additional cleaning operation by clicking “OK” on the display, an electric signal indicative of initiation of the additional cleaning operation is transmitted from the computer to the control portion 6 of the composite machine 1. In response to the electric signal, the control portion 6 controls the recording head 40 to start the additional cleaning operation (S7).
The additional cleaning operation may be the same as the head cleaning operation described above that includes the initial ink sucking action and the initial ink ejecting action including the all-nozzle-ink-ejecting action and the partial-nozzle-ink-ejecting action. Alternatively, the additional cleaning operation may be different from the head cleaning operation described above. For instance, the additional cleaning operation may include only the initial ink sucking action without the initial ink ejecting action or only the all-nozzle-ink-ejecting action without the partial-nozzle-ink-ejecting action. During the additional cleaning operation, there is suitably made, on the display, an indication which indicates that the additional cleaning operation is now in progress or an indication which indicates a state of progress of the additional cleaning operation. Thus, even when the result of the test recording is bad, the additional cleaning operation is not immediately executed. Instead, the user first recognizes the execution of the additional cleaning operation and the additional cleaning operation is then executed after acknowledgement by the user, so that the user is allowed to make preparations necessary for the additional cleaning operation. It is desirable to execute, if possible, the additional cleaning operation, in order to completely remove the mixed ink from the recording head 40. However, the additional cleaning operation may be omitted if the user accepts somewhat lowered quality level judged based on the results of the test recording and the mixed ink is removed by use of the inks in image recording. In this case, the composite machine 1 is placed into the wait state upon the termination of the test recording. As noted above, the indication which encourages the additional cleaning operation may be made on the liquid crystal display portion of the operation panel 4 of the composite machine 1, in place of the display of the computer. Similarly, the input for allowing the additional cleaning operation may be made through the control buttons of the operation panel 4, in place of the input members.
After the additional cleaning operation, the test recording is encouraged to be executed again, and the test recording is executed. When there is made an input that the result of the test recording is good, the composite machine 1 is placed into the wait state for image recording (S8), whereby the cleaning operation of the recording head 40 upon the initial working of the composite machine 1 is completed. Where there is made an input that the result of the test recording performed after the first execution of the head cleaning operation is good, the composite machine 1 is placed into the wait state (S8) without executing the additional cleaning operation, whereby the cleaning operation of the recording head 40 upon the initial working of the composite machine 1 is completed and the composite machine 1 is ready to perform recording immediately after the head cleaning operation.
In the present composite machine 1 constructed as described above, the mixed ink which have entered the nozzles 50, the manifold chambers 53 and the buffer tanks 54 during its transportation or storage before the initial working thereof can be removed by the initial ink sucking action. Further, the mixed ink that cannot be removed by the initial ink sucking action can be completely removed by the all-nozzle-ink-ejecting action and the partial-nozzle-ink-ejecting action which is executed for the specific nozzles 50T described above while reducing the entire ink consumption amount in the initial ink ejecting action.
Referring next to the block diagram of
Referring next to
Where the composite machine 1 is packed as described above, the recording head 40 assumes a posture shown in
With the recording head 40 kept in the condition, the inks which leak from the ink ejection nozzles 50a of the nozzles 50 during transportation or storage after shipment drop and mix with each other in the cap 49. In this case, the thus mixed ink I enters the insides of the nozzles 50 from the ink ejection openings 50a. Further, the mixed ink I flowed into the nozzles 50 may diffuse into the buffer tanks 54. This second embodiment relates to a head cleaning method to be practiced when the composite machine 1 is initially used by users after the manufacture thereof or the quality inspection conducted thereon through the transportation or storage period, for the purpose of avoiding contamination due to the mixed ink during the transportation or storage period.
Because the second embodiment differs from the illustrated first embodiment only in the at least one specific nozzle 50T in the partial-nozzle-ink-ejecting action (S4), and other processing such as the initial ink sucking action and the all-nozzle-ink-ejecting action and the structure of the composite machine 1 are the same as those in the first embodiment, the following explanation is limited to that different portion.
In the second embodiment, the at least one specific nozzle 50T is constituted by the nozzles 50 located at a lower portion of the recording head 40 which assumes the posture shown in
In the second embodiment, the composite machine 1 is accommodated in the box 107 with its front and rear extending in the vertical direction. The arrangement according to the second embodiment is true of a case in which the composite machine 1 is accommodated in the box 107 with its two sides extending in the vertical direction.
Next, there will be explained a third embodiment of the invention. Because the third embodiment differs from the illustrated first or second embodiment only in the at least one specific nozzle 50T in the partial-nozzle-ink-ejecting action (S4), and other processing such as the initial ink sucking action and the all-nozzle-ink-ejecting action and the structure of the composite machine 1 are the same as those in the first or second embodiment, the following explanation is limited to that different portion.
In this third embodiment, the at least one specific nozzle 50T is constituted by the nozzles 50 for ejecting the magenta ink (M) and the yellow ink (Y) except the nozzles 50 for ejecting the cyan ink (C) which is the darkest among the three color inks (C, M and Y), among the nozzles 50 located in the vicinity of the downstream portion of each manifold chamber 53 remote from the corresponding ink inlet 52a as shown in
As noted above, the cap 49 has the first cap portion 49a for fluid-tightly covering the black-ink ejection openings 50a from which is ejected the black ink and the second cap portion 49b for fluid-tightly covering the color-ink ejection openings 50a from which are ejected the color inks, i.e., the cyan ink (C), the magenta ink (M) and the yellow ink (Y). Accordingly, the black ink and the color inks (C, M and Y) are prevented from mixing with each other in the cap 49 when the cap 49 fluid-tightly covers the nozzle surface of the recording head 40. It is noted that, among the color inks ejected from the color-ink ejection openings 50a arranged to be fluid-tightly covered with the second cap portion 49b, one of the color inks which is the darkest relative to the other color inks is less likely to be influenced by the contamination with the mixed ink in the recorded image.
Therefore, the at least one specific nozzle 50T is constituted without including the nozzles 50 for ejecting the cyan ink (C) which is the darkest relative to the other color inks, whereby the partial-ink-ejecting action (S4) is not executed for the nozzles which eject the cyan ink (C). This arrangement is effective to reduce, in the initial ink ejecting action, the consumption amount of the dark color ink which is less likely to be influenced by the mixed ink while executing the partial-ink-ejecting action only for the nozzles for ejecting the other color inks which are likely to be influenced by the mixed ink. In this third embodiment, among the three color inks, C, M and Y ejected from the ink-ejection openings 50a of the nozzles 50 which are arranged to be fluid-tightly covered by the second cap portion 49b of the cap 49, the darkest color ink is determined to be the cyan ink (C). It is noted, however, that the darkest color ink is determined relatively depending upon the shade or tone, among the color inks ejected from the ink-ejection openings 50a that are arranged to be fluid-tightly covered by the second cap portion 49b of the cap 49. Therefore, the darkest color ink is not limited to the cyan ink (C).
Next, there will be explained a fourth embodiment of the invention. Like the illustrated third embodiment, the fourth embodiment differs from the illustrated first or second embodiment only in the at least one specific nozzle 50T in the partial-nozzle-ink-ejecting action (S4) and other processing such as the initial ink sucking action and the all-nozzle-ink-ejecting action and the structure of the composite machine 1 are the same as those in the first or second embodiment. Therefore, the following explanation is limited to that different portion.
In this fourth embodiment, the at least one specific nozzle 50T is constituted by the nozzles 50 for ejecting the yellow ink (Y) which is the lightest among the three color inks (C, M and Y), among the nozzles 50 located in the vicinity of the downstream portion of each manifold chamber 53 remote from the corresponding ink inlet 52a as shown in
As noted above, the cap 49 has the first cap portion 49a for fluid-tightly covering the black-ink ejection openings 50a from which is ejected the black ink and the second cap portion 49b for fluid-tightly covering the color-ink ejection openings 50a from which are ejected the color inks, i.e., the cyan ink (C), the magenta ink (M) and the yellow ink (Y). Accordingly, the black ink and the color inks (C, M and Y) are prevented from mixing with each other in the cap 49 when the cap 49 fluid-tightly covers the nozzle surface of the recording head 40. It is noted that, among the color inks ejected from the color-ink ejection openings 50a which are arranged to be fluid-tightly covered with the second cap portion 49b, one of the color inks which is the lightest relative to the other color inks tends to be influenced by the contamination with the mixed ink in the recorded image.
Therefore, the nozzles 50 for ejecting the yellow ink (Y) which is the lightest relative to the other color inks are determined as the at least one specific nozzle 50T, whereby the partial-ink-ejecting action (S4) is executed only for the nozzles which eject the yellow ink (Y). This arrangement is effective to reduce, in the initial ink ejecting action, the consumption amount of the other color inks which are less likely to be influenced by the mixed ink. In this fourth embodiment, among the three color inks, C, M and Y ejected from the ink-ejection openings 50a of the nozzles 50 which are arranged to be fluid-tightly covered by the second cap portion 49b of the cap 49, the lightest color ink is determined to be the yellow ink (Y). It is noted, however, that the lightest color ink is determined relatively depending upon the shade or tone, among the color inks ejected from the ink-ejection openings 50a that are arranged to be fluid-tightly covered by the second cap portion 49b of the cap 49. Therefore, the lightest color ink is not limited to the yellow ink (Y).
It is to be understood that the present invention may be embodied with various changes and modifications, which may occur to those skilled in the art, without departing from the spirit and scope of the invention defined in the attached claims.
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