Recovery device, ink jet apparatus having recovery device and recovery method

Abstract: A recovery mechanism for ink ejection recovery of an ink jet device includes a wiping member (35) for wiping a surface having an ink ejection outlet by relative movement between the wiping member and the surface; and a rubbing member (40) for rubbing the wiping member by relative movement therebetween, the rubbing member being heated at a predetermined temperature.

Description: The present invention relates to a recovery device, an ink jet apparatus having the recovery device and recovery method. A known recording apparatus having the function of a printer, copying machine, facsimile machine or the like, or a known recording apparatus usable as an output device for a combined electronic machine or a work station including a computer and a word processor, is designed such that an image (including characters or the like) is recorded on a recording material in the form of a sheet of paper or plastics sheet or the like in accordance with image information (character information). Such recording machines are classified, on the basis of the recording systems, into an ink jet type, a wire dot type, a thermal type, a laser beam type or the like. In a serial type recording apparatus in which the main scan occurs in a direction crossing with the heat material feeding direction (sub-scan direction), the recording material is set at a recording position, and thereafter, the recording material is scanned in the main scan direction by recording means carried on a carriage movable along the recording material. After recording of one line has been completed, the sheet is fed through a predetermined distance, and stopped Then, recording of the next line (main scan) is carried out. By repeating these operations, recording is effected on all of the recording material. On the other hand in a line type recording apparatus in which only a sub-scan is effected during the recording operation, the recording material is set at the predetermined recording position, and recording of one line is effected simultaneously, and the recording material is continuously fed to effect the record on all of the recording material. In the ink jet type recording apparatus, ink is ejected onto the recording material from a recording means (recording head) in accordance with an image signal. This is advantageous in that the size of the recording means can be reduced, fine images can be recorded at high speed, plain paper is usable without special treatment, running costs are low, noise is low because it is non-impact type, and it is easy to effect color image recording using a number of different color inks. Among ink jet type recording apparatus, a full-multiple recording means having a large number of ejection outlets arranged in the direction of the width of the sheet is advantageous because the recording speed can be further increased. Particularly, an ink jet type recording means (recording head) which ejects ink using thermal energy can be easily manufactured with high density liquid passages (ejection outlets), because it can be manufactured using etching, evaporation, sputtering or another semiconductor manufacturing processes to form electrothermal transducers, electrodes, liquid passages and top plate, with the electrothermal transducers and electrodes being formed as films on a substrate. In addition, a high resolution image can be recorded at a high speed using a compact structure. On the other hand, various materials for the recording material are desired to be used. Recently, in addition to the usual plain paper or resin thin sheet (OHP sheet or the like), thin paper sheet or processed sheet sheet having perforations for filing, sheet with cutting perforations, or non-rectangular sheet), are desired to be used with printers. In an ink jet recording apparatus, liquid ink is ejected, and therefore an increase in the viscosity of the ink results from evaporation of the water content in the ink. When the viscosity increases, an ejection outlet may be clogged. This may result in improper ejection or ejection failure and therefore a degraded image quality. In order to prevent this inconvenience, the following measures are taken. Upon start up of the apparatus, high viscosity ink extends far into the ejection outlet, and the viscosity of the ink adjacent the ejection outlet is so high that proper ejection is not possible. Therefore, as a first measure, the viscosity increased ink is forcedly discharged by pressurizing or suction pump. In the case of on-demand type recording means, there may be an ejection outlet or outlets which does or do not eject ink for a certain period of time during the recording operation. Such an ejection outlet will become completely clogged sooner or later. Therefore, as a second measure, ink is ejected through all of the ejection outlets (idling or preliminary ejection) irrespective of the image information before the certain period elapses, thus preventing clogging of the ejection outlet. After the first measure is executed, ink discharged by the pressurizing or suction pump exists adjacent the ejection outlet and, therefore, a desired ejection performance is not maintained. Even if the second measure is carried out, ink mist accumulates on the ejection side surface of the recording means after several idle ejection operations, and may clog the ejection so that the ejection performance is not as desired. In view of the above, after the above-described measures have been carried out, a cleaning operation for removing ink deposited adjacent to the ejection outlet, is carried out. Conventional cleaning methods are classified into three types. In a first type, an ink absorbing material such as sponge is brought into contact with the ejection side surface of the recording means. However, this method involves a problem in that, with the aging of the sponge, removed small pieces of the sponge or dried ink deposited on the sponge may enter the ejection outlet resulting in clogging. In a second type, an air flow is produced from an air nozzle along the ejection side surface of the recording means, thus blowing deposited ink out into an ink sump. However, this method involves a problem in that it is difficult to completely remove the ink and costs are increased because of the increase of the number of parts which include an air pump or an air nozzle. In a third type, the ejection side surface of the recording means or head is rubbed by a wiping member such as rubber blade or the like, thus removing the ink. This method is advantageous in that the ink removing power is high, costs are low and the removing operation is quick. Therefore, this method is widely used. Recently, it has been proposed for an ink jet recording apparatus that an ink is used which is solid at normal temperature and such ink is liquefied by heating before being ejected through an ejection outlet. This is advantageous in that the image can be fixed quickly. In an ink jet recording apparatus using such solid ink, a cleaning operation is required, and the cleaning by the wiping member such as rubber blade or the like is similarly advantageous. However, in the ink jet recording apparatus of the type in which solid ink is liquefied at a temperature higher than room temperature before ejection, if a cleaning operation is carried out by a wiping member such as a rubber blade, the liquid ink deposited on a part of the wiping member surface solidifies with decrease in the temperature of the ink. If a cleaning operation is then carried out again, the wiping member does not completely contact the ejection side surface and cleaning is incomplete. In order to prevent this, it would be necessary for the wiping member such as a rubber blade or the like to be heated to a temperature higher than the fusing point of the solid ink. With such a heating method, however, the temperature increasing period is long because of the low thermal conductivity of rubber. The power consumption is also increased. US-A-4,935,753 discloses a recovery mechanism for carrying out ink ejection recovery in an ink jet device, comprising a wiping member for wiping an ink ejection outlet surface by relative movement between the wiping member and the surface and a rubbing member for rubbing the wiping member by relative movement therebetween. According to an aspect of the present invention, there is provided an ink jet recording apparatus in accordance with claim 1. In another aspect the present invention provides a recovery mechanism for use in an ink jet recording apparatus, said recovery mechanism having the features recited in claim 7. Further according to the invention there is provided a method having the steps set out in claim 10. By means of a recovery mechanism embodying the invention, solidified ink deposited on the wiping member is liquified and removed by the heated rubbing member, so that the ejection side surface can be always in a cleaned state, that is, free of deposited ink. In other words, even if solid ink is used, the ejection side surface can be completely cleaned by the rubber blade structure without the necessity of heating the wiping member such as rubber blade or the like. An embodiment of the present invention provides an ink jet recording apparatus in which the ink deposited on the surface of the wiping member can be easily removed even if the ink which is solidified at a temperature higher than the room temperature is used. An embodiment of the present invention provides an ink jet recording apparatus in which the ejection side surface of a recording means is cleaned by a wiping member at all times, thus preventing improper ejection or ejection failure due to incomplete cleaning. An embodiment of the present invention provides a recovery device or method with which the ejection side surface of an ink jet device can be properly cleaned. In the accompanying drawings:- Figure 1 is a schematic perspective view of an ink jet recording apparatus according to a first embodiment of the present invention. Figure 2 is a partial perspective view of an ink jet ejection portion of recording means of the apparatus of Figure 1. Figure 3 is a partial plan view of a major part of an ink jet recording apparatus according to the first embodiment. Figure 4 is a sectional view along a line 4-4 in Figure 3. Figure 5 is a flow chart of sequential operations of the ink jet recording apparatus of the first embodiment. Figure 6 is a partial plan view of a major part of an ink jet recording apparatus according to a second embodiment of the present invention. Figure 7 is a partial front view of a cap of an ink jet recording apparatus according to a third embodiment of the present invention. Figure 8 is a sectional view taken along a line 8-8 in Figure 7. Referring to the accompanying drawings, embodiments of the present invention will be described. Figure 1 is a schematic perspective view of a major part of an ink jet recording apparatus according to a first embodiment of the present invention. In Figure 1, four recording head (recording means) 1a, 1b, 1c and 1d are detachably mounted at predetermined intervals on a carriage 2 which is reciprocable along the surface of a recording material 14 in the form of a sheet of paper or plastic film. In the case of color printing, the recording heads contain cyan, magenta, yellow and black inks, respectively. In the following description, when any one or all of the recording heads are designated, it or they are called simply recording head 1 or recording means 1. The carriage 2 is guided and supported on guide rails 8 and 9, and is fixed to part of an endless belt 10 stretched between a motor pulley 11 and a tension pulley 12. By driving the motor pulley 11 using a carriage motor 13, the carriage 2 is scanned in the main scan direction (F) along the surface of the sheet of the recording material 14. At this time, the clearance between the ejection side surface of the recording head 1 and the recording material 14 surface is approximately 0.5 mm. The supplied recording material 14 is nipped between a feeding roller (sheet feeding roller 15 and a pinch roller (sheet pinching roller) 16, is fed to a position along the surface of a platen 19, and is nipped between a tension roller 17 and a tension pinching roller 18. Thereafter, the sheet is discharged. The platen 19 is disposed at a position facing the recording head 1. A recording operation is carried out on the recording material 14 at the position of the platen 19. The feeding roller 15 is driven by a feeding roller 20, and the driving force of the feeding motor 20 is also transmitted to the tension roller 17 through a motor gear 21, an idler gear 22 and a tension roller gear 23. The peripheral speed ratio between the feeding roller 15 and the tension roller 17 is approx. 1:1.05 for example. The friction force when the recording material 14 is nipped is smaller at the tension roller 17 side than at the feeding roller 15 side and therefore the tension roller 17 and the tension pinching roller 18 slide slightly on the recording material 14, so the recording material 14 is tensioned on the platen 19 to a predetermined degree. This enables contact between the recording material 14 and the recording head 1 to be prevented. The recording head 1 is an ink jet recording means for ejecting ink using thermal energy and is provided with an electrothermal transducer for producing thermal energy. The recording head 1 ejects ink using the pressure change caused by expansion and collapse of a bubble due to film boiling of ink caused by thermal energy applied by the electrothermal transducer. Recording is effected by the ejected ink. Figure 2 is a perspective view of an ink ejection outlet of the recording head 1. The surface having the ejection outlet 82 faces the recording material 14 with a predetermined clearance (approx. 0.5 - 2.0 mm, for example) therebetween. The surface 81 is provided with a plurality of ejection outlets 82 arranged at a predetermined pitch. An electrothermal transducer (heat generating resistor, for example) 85 for producing ink ejection energy is mounted on a wall of each of a plurality of liquid passages 84 communicating between a common liquid chamber 83 and the respective ejection outlets 52. The recording head 1 is carried on the carriage 2 so that the ejection outlets 82 are arranged in a direction crossing the direction (main scan direction) of movement of the carriage 2. The electrothermal transducers 85 are driven or energized in accordance with an image signal or ejection signal, by which ink in the passage 84 is film-boiled and then ejected through the ejection outlet 82 by the pressure produced thereby, in the recording mechanism (recording head) 1. In Figure 1, a cap 26 is disposed at a position outside the platen 19 and the recording region for hermetically capping the ejection outlets 82 of the recording head when a recording operation is not being carried out. The cap 26 defines four spaces 34 corresponding to the respective recording heads (four recording heads in the illustrated example). The spaces 34 are in communication with an air pump 31 through air tubes 27. Below the cap 26, there is a first discharged ink container 30 for receiving discharged ink. A rubber blade (wiping member) 35 is disposed between the cap 26 and the platen 19 to clean (wipe) the ejection side surface of the recording head 1. The rubber blade is mounted on a holder 36 which is rotatable in a direction indicated by arrow D in Figure 3. Adjacent the rubber blade 35, there is a projection (projected member) 40 for wiping a free end portion of the rubber blade 35. Figure 3 is a partial plan view of the wiping member 35 in the ink jet recording apparatus of Figure 1 when the recording head 1 is capped with the cap 26. Figure 4 is a sectional view taken along a line 4-4 in Figure 3. In Figures 1 - 4, the ejection side surface 81 of the recording head 1 has 128 ejection outlets 82 arranged at 16 outlets per mm, for example. By driving (electric power supply) the electrothermal transducers 85 in the ejection outlets 82 in response to image signals, ink is ejected through proper ejection outlets 82 to record an image on the recording material 14. As shown in Figure 4, the recording head 1 is integral with an ink container 3 containing solid ink. As shown in Figures 1 and 3, the recording heads 1a, 1b, 1c and 1d are provided with heaters 4a, 4b, 4c and 4d, respectively, for controlling the temperature of the heads. In the following descriptions, when any one or more of the head temperature controlling heaters 4a,4b,4c and 4d are referred to it or they are simply called head temperature control heater 4. In Figure 4, the fusing point of the solid ink in the ink container 3 is approx. 75 °C, for example, and the solid ink is fused or liquefied by the head temperature controlling heater 4, and is supplied to a common liquid chamber 83 of the recording head 1 through an ink supply pipe 5. Further, it is supplied into the liquid passage 84 connected with associated ejection outlet 82. The ink in the liquid passage 84 and the common chamber 83 is kept in the liquid state by the heat temperature controlling heater 4. Above the ink container 3, there is provided an ink supply port 6 and a cover 7 for hermetically closing it. When insufficiency of the ink is detected by ink amount sensor not shown, the cover is slid in the direction indicated by an arrow B to open the supply port 6, thus permitting supply of the ink through the supply port 6. In Figures 3 and 4, the entirety of the cap 26 is maintained at 80 °C for example, by the heater 24. The surface of the cap 26 facing the recording head 1 is provided with a capping rubber (sealing member) 25 for hermetically sealing the ejection outlet 82 when it contacts the ejection side surface 81 of the recording head 1. By movement in the direction indicated by an arrow E, the cap 26 is engageable with and disengageable from the ejection side surface 81 of the recording head 1. The space 34 of the cap 26 is in communication with a common air pump 31 through air ports 32 and air tubes 27. Below the cap 26, a discharge ink port 33 is formed communicating with the spaces 34 and the outlet part of the discharge ink port 28 is provided with a valve 28. The valve 28 is rotatable in a direction C in Figure 4. Normally, it is at an open position, where its weight brings it into contact with a stopper 29, at 45 degrees from the horizontal. The residual ink from the ink port 33 is discharged into the first discharge ink container 30. In Figures 1 and 3, the holder 36 having the wiping member (blade rubber) 35 mounted thereto is driven by an unshown motor through a pulley 39, wire 38 and a small pulley 37. The projection (projected member) 40 for wiping the end portion of the wiping member 35 is maintained at a temperature of approx. 80 °C by a heater 41. Below the projection 40, there is disposed a second residual ink container 42 for receiving the ink removed from the wiping member 35. Figure 5 is a flow chart illustrating the sequential operations of the ink jet recording apparatus described above. Referring to Figures 1 - 5, the operation of the ink jet recording apparatus will be described. When the main switch (S1) of the recording apparatus is actuated, the temperatures are increased (S2) until the temperature of the recording head 1 reaches 90 °C; the temperature of the cap 26 reaches 80 °C; and the temperature of the projection 40 reaches 80 °C. The temperatures are detected by unshown sensors. At this time, the carriage 2 is at the home position, and the cap 26 seals the ejection outlets 82 by contacting to the recording head 1. When the above-described predetermined temperature are reached, the valve 28 is closed, and the pump 31 is driven for a predetermined period of time (S3). This produces a vacuum in the spaces 34 of the cap 26, so that liquefied ink in the ink container 3 is sucked into the common liquid chamber 83 through the ink supply pipe 5. When liquefied ink is supplied to the common chamber 83, a small quantity of the ink is sucked out through the ejection outlets 82, and the ink is received at the bottom portion of the spaces 34 via the cap rubber 25. After the pump 31 has been stopped, the valve 28 is opened, so that the ink in the spaces 34 is discharged into the first residual ink container 30 (S4). Subsequently, a recording signal is supplied (S5) and then the cap 26 is spaced apart from the recording head 1 (S6), and the carriage 2 is moved toward the right (arrow F) in Figure 3 (S9). The wiping member 35 is placed at a position indicated in Figure 3 (S8). At the instance when the ejection side surface 81 of the first recording head 1a is contacted thereto, the wiping member 35 starts to rotate in the direction D (S10). By the rotation of the wiping member 35, the ejection side surface 81 of the recording head 1a is cleaned (wiped). The rotational speed of the wiping member 35 and this time are set such that when the wiping member returns to Figure 3 position after one full rotation, the right hand end of the ejection side surface 85 of the (second) recording head 1b reaches thereto. By the next one turn of the wiping member 35, the ejection side surface 81 of the second recording head 1b is cleaned. The ejection side surfaces 81 of the recording heads 1c and 1d are similarly rubbed or wiped by the wiping member 35, so that they are cleaned. The wiping member (rubber blade) 35 is contacted after cleaning by the projected member 40, after each cleaning operations for the recording heads, that is, for each rotation. This means that ink which was going to be solidified on the free end portion of the wiping member 35 is assured to be in the liquid state by the thermal energy from the projected member 40, for each rotation. In this manner, the ejection side surface 81 can be wiped by the wiping member 35 which is free from ink. Therefore, cleaning is assured without the possibility of the mixture of different color inks on the ejection side surface 81. After cleaning the recording head 1 (S11), the wiping member 35 is stopped at a position which is 270 degrees away from the Figure 3 position in the direction D. After the completion of the cleaning operation, the recording head 1 is moved into the recording region, thus starting the recording operation. On the other hand, the recording material 14 is retained on the platen 19 with a predetermined tension force applied thereto. After the recording head 1 completes one line recording (S12), the feeding roller 15 and the tension roller 17 are rotated through predetermined degree to feed the recording material 14 upwardly by one line (the distance corresponding to 128 ejection outlets, that is, 8 mm in this embodiment). The recording head 1 returns to a lateral end of the recording material 14 (S14), and the next line recording operation is carried out. In the similar manner, the movement of the recording head (main scan direction) and the feeding of the recording material 14 (sub-scan direction), are alternately repeated to effect the recording operation on the entire surface of the recording material 14. After the recording operation, the recording material 14 is discharged (S15). In order to prevent clogging due to the dried ink of ejection outlets 82 which are not used during the recording operation, the recording head 1 is returned to a position (home position, for example) where it faces the cap 26 (S16) at regular intervals (after each three line recording, for example), and ink is ejected through all of the ejection outlets 82 a predetermined number of times (50 idle ejections, for example). At the time of the idle ejection, the wiping member 35 is rotated to the cleaning position shown in Figure 3, and also after the completion of the idle ejection, ejection side surfaces 81 of the recording head 1 are cleaned (wiped). By so doing, possible improper ejection attributable to ink mist accumulated on the ejection side surface 81 can be prevented. After completion of the recording operation, the recording head is capped (s17) at the home position. According to this embodiment described above, for each cleaning operation for the ejection side surface 81, relative movement is imparted while the wiping member 35 is in contact with the projection 40 which has a temperature not less than the solid ink fusing point, ink deposited on the surface of the wiping member 35 can be easily and completely removed while maintaining the ink in a liquid state, even in an ink jet apparatus in which a solid ink which is liquefied at a temperature higher than the room temperature is used, and is liquefied and ejected by a recording head 1, and a wiping member 35 is provided to clean the ejection side surface 81 of the recording head 1. Therefore, it becomes possible to clean the ejection side surface 81 of the recording head by a wiping member which is always free from ink, and improper ejection, including ejection failure attributable to the incomplete cleaning can be assuredly avoided. Referring to Figure 6, there is shown a major part of an ink jet recording apparatus according to a second embodiment of the present invention. In this embodiment, the projections (projected member) 43a, 43b, 43c and 43d which are relatively movable with respect to the wiping member (rubber blade) 35 while being in contact therewith, are integrally formed or mounted on the recording head (recording means) 1. When any one or all of the projections 43a, 43b, 43c and 43d, are designated, it or they are called simply projection 43. In Figure 6, the wiping member (rubber blade) 35 is disposed between the recording region and the cap 26 and fixed on a holder 36. On the other hand, a carriage 2 reciprocable along guide rails 8 and 9, carries four recording heads 1a, 1b, 1c and 1d at predetermined intervals. The left side surfaces of these recording heads are provided with head temperature controlling heaters 4a, 4b, 4c and 4d. When any one or all of these heaters are designated, it or they are simply called heater 4. Each of the projections 43 is connected to the left side surfaces of the heaters 4 in the Figure. The heater 4 is fixed by being sandwiched between the recording head 1 and the projection 43, so that heat can be transferred to both of them. The projection (projected member) 43 is of aluminum or another material having high thermal conductivity. It is so disposed that the end portion rubs the end portion of the wiping member 35 during movement of the carriage 2, as indicated by chain lines in Figure 6. Below the wiping member 35, a second residual ink container 44 is disposed. The second residual ink container 44 is so disposed as to cover the wiping member 35 region and a recording region of the recording head 1 (recording scan stroke range). The second embodiment shown in Figure 6 is different from the first embodiment of Figures 1 - 5, in the above-described respects. In the other respects, they are substantially the same. More particularly, the recording mechanism, the recovery mechanism (for Preventing clogging of the ejection outlets 82) comprising the cap 26 and the air pump 31 (Figure 3), and the like, are substantially the same as in the case of the first embodiment. In the operation of the apparatus of this embodiment, the recording head 1 and the projection 43, are controlled to be at a temperature of 180°C approximately, for example by the respective heaters. Similarly to the first embodiment, the cap rubber 25 of the cap 26 contacts the ejection side surface 81 of the recording head 1 so as to hermetically seal the ejection outlets 82. Thereafter, the air pump 31 is operated to provide a sucking action. When the recording signal is produced, the cap 26 is retracted (separated), and the carriage 2 is moved into the recording region. During the movement, the wiping member (rubber blade) 35 is first brought into contact with the ejection side surface 81 of the recording head 1a at the end portion of the blade 35, so that the cleaning operation (wiping operation) is carried out. Immediately thereafter, the end portion of the wiping member 35 is brought into contact with the end portion of the first projection (the projection of the first recording head 1a) 43a, so that the ink (cyan ink in this embodiment) which is going to be solidified on the wiping member 35 is wiped out while being maintained in the liquid state, by the projection 43a. The removed ink falls into the second residual ink container 44. The ejection side surface 81 of the second recording head 1b is cleaned (wiped) by the wiping member 35. Immediately thereafter, the ink (magenta ink) which is going to be solidified on the wiping member 35 is removed by the second projection 43b while it is being liquefied. The removed ink falls into the second residual ink container 44. In a similar manner, the cleaning operation (wiping operation) for the third recording head 1, the wiping operation for the wiping member 35 by the third heated projection 43c, the cleaning of the fourth recording head 1d, and the cleaning of the wiping member 35 by the fourth heated projection 43d, are carried out. The operations of the second embodiment shown in Figure 6, other than the operations described above, are Substantially the same as with the first embodiment. Therefore, the same advantageous effects has in the first embodiment, can be provided by the second embodiment. In addition, the recording heads 1 and the projections 43 are heated by a common heater 4, and therefore, the number of temperature controlling circuits can be reduced as compared with the case of the first embodiment. With the structure of Figure 6, there is no need of a mechanism (Figure 3) for rotating the wiping member 35, and therefore, the structure of the apparatus can be correspondingly simplified. Referring to Figure 7, there is shown an ink jet recording apparatus according to a third embodiment of the present invention (cap 26). Figure 8 is a sectional view taken along a line 8-8 in Figure 7. In this embodiment, the wiping member for cleaning the ejection side surface 81 and the projection for wiping and cleaning the wiping member, are on capping means (cap) 26. In Figures 7 and 8, there are four spaces 34 in the cap 26, corresponding to the four recording heads 1. The spaces 34 are in communication with air ports 32 and discharge ink ports 33. In this embodiment, a cap plate 45 is mounted on a front side of the cap 26, and a hermetic sealing capping rubber 25 is mounted on the front side of the cap plate 45. The capping plate 45 and the capping rubber 25 are provided with openings for receiving the ink ejecting part of the recording head 1 and for communication with the spaces 34. Below the opening of the cap plate 45, a projection 46 is formed into the space 34. The cap plate 45 and the cap 26 are thermally connected, and they are temperature-controlled at approx. 80 °C by a cap temperature control heater 24. At an upper portion of the cap 26, blade shafts 47a, 47b, 47c and 47d extending into the spaces 34, are mounted for vertical movement in the sealed state. When any one or all of the blade shafts are designated, it or they are called blade shaft 47. The blade shaft 47 is substantially vertically movable simultaneously in a direction indicated by an arrow G by an unshown transmitting means such as a cam. To the end portions (the portions always in the spaces 34) of the four blade shafts 47, wiping members (rubber blades 48a, 48b, 48c and 48d) are mounted by screws 47. When any one or all of the wiping members is referred to hereinafter, it is or they are called simply wiping member 48. When the wiping member 48 moves substantially in the vertical direction, the end portion thereof rub the ejection side surface 81 which is in the cap state, so that they are cleaned, and in addition, the wiping members 48 are cleaned by the projections 46. The third embodiments shown in Figures 7 and 8, are different in these respects from the first embodiment shown in Figures 1 - 5, but they are substantially the same in the other respects, and therefore, the detailed descriptions thereof are omitted for simplicity by assigning the same reference numerals to the elements having the corresponding functions. In operation of the apparatus of this embodiment, similarly to the first embodiment, the recording heads are heated to a predetermined temperature higher than the fusing point of the ink by the heater 4 (Figure 3) or the like. The cap 26 and the cap plate 45 having the projections 46 are heated to approx. 80 °C by the cap temperature controlling heater 24. The caps 26 are contacted to the recording heads 1, and the suction pump 31 is operated. With the capped state maintained, the blade shafts 47 are lowered from the position shown in Figures 7 and 8. During the lowering movement, the wiping members 48 clean or wipe the ejection side surfaces 82 of the recording head 1. After the cleaning operation, the end portions of the wiping member 48 are rubbed by the projections 46, so that the ink deposited on the wiping member 48 is removed. The removed ink, similarly to the first embodiment, falls in the first residual ink container 30 through the residual ink port 33. Thereafter, the cap 26 is removed from the ejection side surface 82, and the blade shaft 47 are raised to the original position indicated in the Figure. Thereafter, the carriage 2 is moved into the recording region to start the recording operation. The operations of the apparatus of this embodiment other than those described above, are substantially the same as in the first embodiment. Therefore, according to the embodiment of Figures 7 and 8, the same advantageous effects as in the first embodiment can be provided. In addition, since the wiping member 48 and the projections 46 are in the cap 26, both the ink sucked out by the pump 31 and the ink wiped off the wiping member 48, can be received by a single residual ink container 30, so that the necessity for the second residual ink containers 42 and 44 is eliminated. Thus, the apparatus is simplified. In the foregoing embodiments, the ink jet recording apparatus has been described as having a plurality of recording head 1 containing different color inks. However, the present invention is applicable to an ink jet recording apparatus having a single recording head, or to an ink jet recording apparatus for tone reproducing using a plurality of recording head having the same color but different densities, that is, the present invention is applicable irrespective of the number of recording heads or the number of inks. In the foregoing embodiments, the ink jet recording apparatus is of a serial scanning type in which the recording head is carried on a carriage 2. However, the present invention is applicable to a line type ink jet recording apparatus in which a line type recording head having a length covering an entirety or a part of the width of the recording material is used, so that the recording operation is carried out by the sub-scan direction movement. In that case, the wiping member is heated, and the same advantageous effects can be provided. As for the recording head (recording means), it may be a cartridge type which is integral with an ink container, or a type in which the recording head is connectable with an ink container through an ink supply tube or the like. That is, the present invention is applicable with the same advantageous effect irrespective of the types of the recording heads. An ink jet recording apparatus to which the present invention applicable may comprise a recording head using electromechanical converters such as piezoelectric elements. However, an ink jet recording apparatus ejecting the ink using thermal energy is most applicable. In this case, a high density and fine image can be produced. The present invention is particularly suitably usable in an ink jet recording head and recording apparatus wherein thermal energy from an electrothermal transducer, laser beam or the like is used to cause a change of state of the ink to eject or discharge the ink. This is because the high density of the picture elements and the high resolution of the recording are possible. The ink jet recording apparatus may be used as an output terminal of an information processing apparatus such as computer or the like, as a copying apparatus combined with an image reader or the like, or as a facsimile machine having information sending and receiving functions. As described in the foregoing, according to the present invention, ink deposited on the surface of the wiping member can be easily and assuredly removed even when a solid ink fusable at a temperature higher than the room temperature is liquefied and then ejected. Therefore, the ejection side surface can be cleaned by an always clean wiping member, and ink ejection or ink ejection failure attributable to incomplete cleaning, can be avoided. The projection may be integral with the recording means, or the wiping member and the projection may be mounted on capping means for hermetically sealing the ejection outlet of the recording means, by which the above advantageous effects can be further assured.

Claims: An ink jet recording apparatus for recording an image on a recording medium by ejecting ink towards the recording medium from an ink ejection outlet (82) of a recording head (1) which uses ink which has been converted by heating from a solid state to a liquid state, comprising: a recovery mechanism for recovering ink ejection properties of the recording head, the recovery mechanism including heating means (41); a wiping member (35) for wiping an ink ejection outlet surface (82) of the recording head during relative movement between said wiping member (35) and the ink ejection outlet surface (82); and a rubbing member (40) for rubbing said wiping member (35) during relative movement between the said rubbing member (40) and said wiping member (35); said heating means (41) being arranged to heat said rubbing member (40) to a temperature higher than the fusing temperature of the solid ink, whereby rubbing of said wiping member by said rubbing member removes any ink deposited on said wiping member. A recording apparatus as claimed in claim 1, wherein said wiping member (35) is movable and is disposed so as to be adjacent the path of movement of said ink jet head. A recording apparatus as claimed in claim 1, wherein said rubbing member (40) is disposed so as to be adjacent said ink jet head and is arranged to be scanned with said ink jet head along a scanning path between a recording region and a non-recording region in use of the apparatus, said wiping member being disposed in the scanning path. A recording apparatus as claimed in claim 1, 2 or 3, wherein a capping member (26) is provided for capping said ink jet head, and said wiping member and said rubbing member are provided at a region of the apparatus in which said capping member is arranged to contact said ink jet head. A recording apparatus as claimed in any one of claims 1 to 4, wherein temperature control means are provided for controlling the temperature of said rubbing member. A recording apparatus as claimed in any one of claims 1 to 5, wherein a heating device (41) is mounted on said rubbing member to maintain said rubbing member at a predetermined temperature. A recovery mechanism for use in an ink jet recording apparatus for recording an image on a recording medium by ejecting ink towards the recording medium from an ink ejection outlet (82) of a recording head ink which uses ink which has been converted by heating from a solid state to a liquid state, said recovery mechanism comprising: a wiping member (35) for wiping an ink ejection outlet surface (82) of the recording head during relative movement between said wiping member and the ink ejection outlet surface (82); a rubbing member (40) for rubbing said wiping member during relative movement between said rubbing member and said wiping member; and heating means (41) for heating said rubbing member to a temperature higher than the fusing temperature of the solid ink, whereby rubbing of said wiping member by said rubbing member removes any ink deposited on said wiping member. A recovery mechanism according to claim 7, wherein temperature control means are provided for controlling the temperature of said rubbing member. A recovery mechanism according to claim 7 or 8, wherein a heating device (41) is mounted on said rubbing member to maintain the latter at a predetermined temperature. A recovery method for recovering ink ejection properties of an ink jet head for an ink jet recording apparatus for recording an image on a recording medium by ejecting ink from an ink ejection outlet of the recording head which uses ink which has been converted by heating from a solid state to a liquid state, which method comprises: wiping an ink ejection outlet surface (81) of said ink jet head by causing relative movement between a wiping member (35) and said surface (81); and rubbing said wiping member (35) after said wiping step by causing relative movement between said wiping member (35) and a rubbing member (40) heated to a temperature higher than the fusing temperature of the solid ink. A method as claimed in claim 10, which comprises disposing said wiping member (35) adjacent a path of movement of said ink jet head, said wiping member itself being moveable. A method as claimed in claim 11, which comprises disposing said rubbing member (40) adjacent said ink jet head and scanning said rubbing member with said ink jet head along a scanning path between a recording region and a non-recording region, disposing said wiping member in the scanning path and causing said wiping member to be rubbed by said rubbing member after wiping said ink jet head. A method according to claim 10, which further comprises capping said ink jet head when said wiping member and said rubbing member are disposed in a region of contact between the capping member and the ink jet head.

Inventors: OKAMURA YOSHITAKA, SUGIYAMA HIROSHI, YAMAMOTO KOSUKE, OKAMURA, YOSHITAKA, SUGIYAMA, HIROSHI, YAMAMOTO, KOSUKE, Okamura, Yoshitaka, c/o CANON KABUSHIKI KAISHA, SUGIYAMA, HIROSHI, C/O CANON KABUSHIKI KAISHA, Yamamoto, Kosuke, c/o Canon Kabushiki Kaisha
Applicants: CANON KK, CANON KABUSHIKI KAISHA
Application year: 1993
Main classification: B41J2
IPC codes: B41J2