An ink jet recording apparatus having a recovery mechanism

Abstract: An ink jet recording apparatus comprises a head for discharging ink corresponding to recording information and a carriage (6) which moves said head in a predetermined direction. A lead screw (2) serves to move said carriage by use of a plurality of lead grooves (3) provided in spiral shape at the peripheral surface as the delivering means, and a regulating member joined to the end of said lead screw and also, except for one lead groove of said plurality of lead grooves into which driving members for said carriage are fitted, having members for impeding egress and ingress of said driving members for said carriage facing the ends of other lead grooves.

Description: BACKGROUND OF THE INVENTION Field of the Invention This invention relates to an ink jet recording apparatus applicable to various printers, and printer portions to be applied to various instruments. Related Background Art This kind of apparatus is equipped with a constitution inherent in the system which performs recording by discharging ink other than the constitution concerned with direct recording. More specifically, corresponding to the recording data, when no discharging is performed at the discharge port or when the apparatus itself is not used for a long term, the ink at the discharge port or within the ink liquid chamber communicated to the discharge port may be sometimes increased in viscosity to cause non-discharging. Also, ink liquid droplets, water droplets or dust, etc. may be deposited on the discharge port surface where discharge port is arranged, whereby the ink liquid droplets may be sometimes drawn by these deposited to be deflected in the discharging direction. For this reason, the ink jet recording apparatus is equipped with various constitutions such as the so called discharging recovery system for preventing non-discharging or deflection of the discharging direction. As these recovery systems, for the constitution which prevents non-discharging, there are preliminarily discharging which removes ink which is increased in viscosity, etc. by discharging ink onto a predetermined ink receiving medium, ink suction which performs the above-mentioned removing operation by sucking ink from the discharge port or the ink liquid chamber, and further capping which prevents ink water evaporation from the discharge port by closing the discharge port surface. Also, for the constitution to prevent deflection of the discharging direction, there is a constitution which wipes the discharge port surface, thereby removing dust, ink liquid droplets, etc. deposited in the vicinity of the discharge port. On the other hand, in the ink jet recording apparatus, above all recording head in recent years, its preparation is now performed by film forming steps of semiconductors or microworking techniques, whereby smaller and less expensive recording heads are going to be realized. Also, recording heads of the disposable type, for example, integrated with an ink tank have been proposed. As the result, it has been desired to have an ink jet recording apparatus which can be used handily by users by making also the apparatus itself small in scale and low in cost. Whereas, for realizing the ink jet recording apparatus as described above, particularly the apparatus corresponding to the type of small scale and low cost, and further the disposable type, there are various tasks to be solved. These tasks exist primarily in the constitution for discharge recovery as descried above, and miniatuarization of the apparatus is hampered by preliminary discharging, ink suction, and further the space for arranging the apparatus for capping. Also, miniatuarization of the apparatus is also hampered by the space for the waste ink tank for storing waste ink by preliminary discharging or suction, and the suction pump, tube, etc. for leading waste ink thereto. Of the constitutions of the above-mentioned recovery systems, particularly in the constitution of performing capping, it has been practiced in the prior art to use the cap for preventing ink evaporation by closing the discharge port from the air also as the cap to be used for sucking ink from the discharge port for eliminating clogging, etc. For this reason, ink water is evaporated from the tube to be communicated to suction pump or these connecting portions, etc., whereby there was a problem that no sufficient effect by closing with the cap could be obtained. Of the constitutions of the above-mentioned recovery systems, particularly the constitution comprising storing waste ink absorbed proposed in the prior art include the constitution in which a waste ink tank is provided at a predetermined position of the apparatus and waste ink is discharged there, the constitution in which a plate-shaped ink absorbing member is plastered internally of the apparatus and waste ink is discharged there to promote evaporation, and further the constitution in which these ink absorbing members are made exchangeable. However, according to the constitutions as described above of the prior art, the space for waste ink tank or ink absorbing member must be ensured, whereby there was a problem that the apparatus became enlarged. Also, there has been known in the prior art a constitution in which waste ink is recovered into an absorber provided in a separate chamber of ink cartridge. However, since this constitution is a constitution in which ink is collected by inserting the needle at the tube tip end for guiding waste ink into the rubber cap of the cartridge, the absorbing ability of the whole absorber could not be made avail of, and consequently it could not be utilized except for the disposable type. Also, in the recovery system, since the connection tube from the cap to the pump, the drain tube from the pump to the waste ink tank are required, the constitutions of these apparatuss become complicated, and also there was involved the problem that the space for arrangement of the tubes was necessary. Also, due to the presence of the tubes, evaporation of ink water from the tubes became increased, whereby the ink within the tube or in the vicinity of the discharge port was increased in viscosity, until finally deposited. Further, since a one-directional valve is provided on the piston shaft, a certain extent of area is required for the piston shaft end for the arrangement portion thereof. For this reason, the diameter of the piston becomes greater, which led to the problem that the pump itself became greater. Also, in this pump, since the load of the solid rubber generally used for formation of the main piston is great relative to deformation, the actuation force of the piston became nonuniform, whereby no stable suction actuation could be performed in some cases. Also, the piston of solid rubber is poor in durability, having no tolerable ability to dust, etc. which can be brought in by suction, whereby the suction effect may be sometimes markedly lowered. Also, as shown in Japanese Laid-open Patent Applications No. 59-14964, No. 59-45161, there has been proposed a constitution of the system in which a blade portion such as rubber, etc. and a non-absorptive cap portion are provided in the circumferential direction and rotated while discharging ink. However, when the ink removed from the head with the blade is attached at the root in the vicinity of the blade, such ink, etc. cannot be removed even with the cleaning member arranged for cleaning the circumferential surface, which caused consequently capping itself to be unstable or the cleaning effect to be deteriorated. Anyway, none of the recovery means of the ink jet recording apparatus can be found to make their functions higher while accomplishing miniaturization. In one aspect, the present invention provides an ink jet recording apparatus comprising: a moving means for moving a recording head having a discharge port surface with a plurality of discharge ports to cause the recording head to scan a recording area and a non-recording area; a cleaning member for cleaning the discharge port surface of the recording head; a contact member for contacting the cleaning member after a cleaning operation, characterised by: control means for controlling the cleaning member to effect reciprocal movement in a direction in which the discharge ports are arranged, the control means being arranged, when said recording head is at said non-recording area, to cause the cleaning member to carry out a cleaning operation by causing the cleaning member to move from a first position to a second position to clean said discharge port surface and to allow ink adhering to the cleaning member to be removed by the contact member after the cleaning member has cleaned the discharge port surface, the control means also be arranged to cause the cleaning member to return from said second to said first position without cleaning the discharge port surface of said recording head after said recording head has been moved by said moving means from the non-recording area to the recording area. In another aspect, the present invention provides a method of operating an ink jet recording apparatus having: a moving means for moving a recording head having a discharge port surface with a plurality of discharge ports to cause the recording head to scan a recording area and a non-recording area; a cleaning member for cleaning the discharge port surface of the recording head; a contact member for contacting the cleaning member after a cleaning operation, the method being characterised by the recording apparatus controlling the cleaning member to effect reciprocal movement in a direction in which the discharge ports are arranged so that when said recording head is at said non-recording area, the cleaning member moves from a first position to a second position to clean said discharge port surface and to allow ink adhering to the cleaning member to be removed by the contact member after the cleaning member has cleaned the discharge port surface and after said recording head has been moved by said moving means from the non-recording area to the recording area the cleaning member returns from said second to said first position without cleaning the discharge port surface of said recording head. An ink jet recording apparatus embodying the invention accomplishes miniaturization and stabilization of its function by improving the means having at least one recovery function which accomplishes miniaturization of the recovery means, preferably further improve its effect by miniaturizing a plurality of recovery means. An ink jet recording apparatus embodying the present invention enables unification of the driving motor and miniaturization as a whole to be accomplished. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a perspective view showing an embodiment of the ink jet printer according to the present invention; Figs. 2A - 2C are partial perspective views showing a blade and ink carrier portion for the recording head; Fig. 3 and Fig. 4 are respecively an exploded perspective view and a sectional view showing an example of a suction recovery system for the recording head; Fig. 5 is a timing chart showing the actuation timings of the respective parts according to an embodiment; Figs. 6A - 6C are plan views for illustration of the positional relationships between the recording head during peliminary discharging, capping and suction recovery and the members provided for those treatments; Figs. 7A - 7D are side sectional views for illustration of the successive actuations of the ink carrier portion; Figs. 8A - 8C are side sectional views for illustration of the successive actuations of the cap portion; Figs. 9A and 9B are side sectional views for illustration of the actuations of performing suction recovery; Fig. 10 is a timing chart for illustration of the sequence during preliminary discharging or suction recovery treatment; Fig. 11 and Fig. 12 are perspective views showing two other forms of the blade and the ink carrier portion; Fig. 13 and Fig. 14 are sectional views showing two other forms of the piston arranged at the pump portion; Figs. 15 through 17 are diagrams for illustration of three other forms of the connecting portion in the suction recovery system behind the cap; Figs. 18 through 20 are perspective views showing three other forms of the waste ink absorbing portion arranged within the paper delivery roller; Figs. 21 through 23 are perspective views showing three other forms of the closed cap portion of the cap; Figs. 24A, 24B, 24C and Fig. 25 are perspective views for illustration of two other forms of the blade; Fig. 26 and 27 are perspective views of other forms of piston for an ink jet recording apparatus embodying the present invention; Fig. 28 is a side sectional view showing the engaged state of the piston and the piston presser of another embodiment of an ink jet recording apparatus in accordance with the present invention. BRIEF DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will hereinafter be described in detail with reference to the drawings. Figure 1 is a perspective view showing the whole of a liquid ejection recording apparatus (an ink jet printer) according to an embodiment of the present invention, Figures 2A - 2C are fragmentary perspective views for illustrating various portions of means for making the discharge opening forming surface of a recording head disposed in the printer good, Figure 3 is an exploded perspective view of a recovery system, and Figure 4 is a cross-sectional view of the pump unit thereof. Referring first to Figure 1, the reference numeral 1 designates a chassis, and a left side plate 1a and a right side plate 1b which serve also as guides for a recording medium such as paper are provided upright on the inner part of the chassis 1. Also, a front side plate 1c is provided upright on the right end portion of the chassis 1, and a carrier guide plate 1d is provided upright on this side of the chassis. The reference character 1e denotes an elongate slot for guiding a carrier, and a carrier guide roller which will be described later is slidably fitted in the slot 1e. Although not shown, a motor mounting hole for rotatably supporting a carrier motor which will be described later is formed in the chassis 1. The reference character 1h designates a lead arm for axially and radially supporting a lead screw which will be described later. The lead arm 1h is supported by a bearing portion (not shown). The reference numeral 2 denotes a lead screw formed with a lead groove 2a at a predetermined pitch relative to the recording range. On the carrier home position side of the lead screw 2, a cap position setting cap groove 3b and a recovery position setting pump groove 3c are formed along the periphery of a cross-section perpendicular to the axis of the lead screw, and these cap groove 3b and pump groove 3c are smoothly connected together by a connecting groove 3d. Further, the lead groove 2a and the cap groove 3b are also smoothly connected together by an introduction groove 3e. A shaft 2g is provided at the right end of the lead screw 2 and a shaft is also provided at the left end of the lead screw, and these shafts are fitted in bearing portions provided on the front side plate 1c and the lead arm 1b, respectively, and are rotatably supported relative thereto. The reference numeral 3 designates a lead pulley including said grooves 3b - 3e and provided on the shaft of the lead screw 2. The lead pulley 3 has a pulley 3a at one end thereof. A drive force is transmitted from a motor 11 to the pulley 3a through a timing belt 13. The right end shaft 2g of the lead screw 2 is urged in the thrust direction by a leaf spring or the like, not shown. The reference numeral 4 denotes a clutch gear supported for axial sliding movement on the lead pulley 3 and engaged by a key not shown, in the direction of rotation so that the rotational force of the lead screw 2 may be transmitted to the clutch gear. The reference numeral 5 designates a clutch spring which is a compression spring for biasing the clutch gear 4 toward the lead groove. Although not shown, a controlling member for permitting the clutch gear 4 moving only within a predetermined range is provided between the clutch gear 4 and the lead pulley 3. The reference numeral 6 denotes a carrier slidably mounted on the lead screw 2. The reference character 6a designates a pressing portion for pressing the end surface of the clutch gear 4. The pressing portion 6a is formed integrally with the carrier on the left side thereof. The reference character 6b denotes a detecting piece for detecting the home position of the carrier 6. The reference numeral 7 designates a lead pin engaged with the lead groove 2a of the lead screw 2 and adapted to be guided by a guide hole (not shown) in the carrier 6. The reference numeral 8 denotes a lead pin spring having one end thereof mounted on the carrier 6 and having the other end for pressing the lead pin 7. The reference numeral 9 designates a recording head carried on the carrier 6. In the present embodiment, the recording head 9 is in the form of a cartridge comprising, as a unit, a head element 9a for effecting ink discharge and an ink tank 9b as an ink supply source, and removably mountable on the carrier 6, and is of the disposable type which is interchangeable as when ink is consumed. As a discharge energy generating element disposed in the head element 9a for causing discharge energy to act on the ink, use may be made of an electro-thermal converting member or an electromechanical converting member, but the former is preferable because of its possibility of making ink discharge openings highly dense and its simplicity of manufacturing process. The reference numeral 10 denotes a carrier roller rotatably mounted on the rear end surface of the carrier 6 and rotatably engaged with the aforementioned elongate slot 1e in the chassis 1. The reference numeral 11 designates a carrier motor comprising, for example, a pulse motor, and having rotatable pins 11a provided in aligned relationship with each other on the lower portions of the front and rear surfaces thereof. These rotatable pins 11a (the one on the rear surface being not shown) are rotatably mounted in a motor mounting hole formed in the chassis 1. The carrier motor 11 is mounted for rotation about the rotatable pins 11a. The reference numeral 11b denotes a spring receiver formed integrally with the carrier motor 11 and provided upright and parallel to the motor shaft to receive a motor spring 14 which will be described later. The spring receiver is formed with a cylindrical projection to which is fixed one end of the coil-like motor spring 14. The reference numeral 12 designates a motor pulley secured to the motor shaft of the carrier motor 11. The reference numeral 13 denotes a timing belt passed over and between the motor pulley 12 and the pulley 3a provided on the shaft of the lead screw 2. In the construction of the present embodiment, the motor spring 14 is a compression spring mounted between one end of the lead arm 1h and the spring receiver 11b of the carrier motor 11, whereby tension is imparted to the timing belt 13 if the carrier motor 11 is biased by the motor spring so as to be rotated in the direction of arrow A in Figure 1. The reference numeral 15 denotes a set shaft provided upright on the left side plate 1a and the having mounted thereon means for making the discharge opening forming surface good, a cap and a mechanism concerned in discharge recovery. The means for making the discharge opening forming surface good will now be described with reference to Figures 1 and 2A - 2C. The reference numeral 16 designates a blade lever (see Figure 2A), and a boss portion 16a is rotatably mounted on the set shaft 15. The reference character 16b denotes an arm portion, and the reference character 16c designates a hook portion. The reference numeral 17 desigantes a blade for wiping the discharge opening forming surface. The blade 17 can be formed of an elastic material such as silicone rubber or chloroprene (CR) rubber. The reference numeral 18 denotes a blade shaft which clamps the blade 17 in the central portion thereof in parallelism to a rotary shaft and which is rotatably mounted on the blade lever 16. The reference 18a designates a pivotable piece formed integrally with the blade shaft 18. The reference numeral 19 denotes an ink carrier formed of a hydrophilic porous material (such as sintered plastic material or urethane foam) and fixed to the blade lever 16. The blade 17 and the ink carrier 19 are disposed at a position whereat they overlap a cap which will be described later. The reference numeral 20 designates a set lever pivotally mounted on the set shaft 15. The reference characters 20a and 20b denote stop teeth provided on the set lever 20, the reference character 20c denotes a start tooth, and the reference character 20d designates a pivotable tooth. The thickness of the start tooth 20c is about one half of the thickness of the other teeth. The reference character 20e denotes an arm portion having a part thereof cut away in the direction of plate thickness to thereby form a set surface 20f and a reset surface 20g to which the pivotable piece 18a of the blade shaft 18 mounted on the blade lever 16 may be fitted to drive the arm portion. The reference numeral 21 designates a timing gear rotatably mounted on the chassis 1. The timing gear 21, as shown in Figure 2B, is formed with a stop cam 21a on a portion of the outer periphery thereof for engaging the stop teeth 20a and 20b of the above-described set lever 20. The timing gear 21 is also formed with partly cut-away driving teeth 21b 1 , 21b 2 , ..., and is further formed with cap cams 21c - 21e at predetermined locations for pivotally moving a cap lever which will be described later. In addition, the timing gear 21 is formed with a piston set cam 21f as a face cam for pressing the piston of a pump which will be described later, and is also formed with a piston reset cam 21g at a predetermined interval correspondingly to the piston set cam 21f. The reference numeral 22 denotes an ink absorber spring fixed to the chassis 1 at a predetermined location thereon, and having an absorber holding portion 22a and a spring portion 22b for rotating the pump which will be described later, as shown in Figure 2C. The reference numeral 23 designates an ink absorber formed of a hydrophilic porous material, like the aforedescribed ink carrier 19. This ink absorber 23 is formed with a wiping portion 23a against which the aforedescribed blade 17 bears, and is further formed in the lower portion thereof with an absorbing surface 23b against which the aforedescribed ink carrier 19 bears to effect delivery of ink. The absorber holding portion of the ink absorber spring 22 is biased upwardly with some resilient force, and is restrained at a predetermined position by a stopper, not shown. Therefore, when the aforedescribed ink carrier 19 bears against the ink absorber 23, the ink absorber 23 flexes the ink absorber spring 22 and is displaced downwardly, whereby the bearing state may be secured. A recovery system unit will now be described with reference chiefly to Figures 3 and 4. In Figures 3 and 4, the reference numeral 24 designates a cylinder having a cylindrical cylinder portion 24a and a guide portion 24b for guiding a piston shaft which will be described later, the guide portion 24b being partly cut away axially thereof to thereby form an ink flow path 24c. The reference character 24d denotes a cap lever receiver formed so as to receive a lever seal which will be described later. The reference character 24e designates an ink flow path which opens at a predetermined location in the cylinder portion 24a. The reference character 24f denotes a pivotable lever formed integrally with the cylinder 24 and adapted to be given a pivoting force by the spring portion 22b of the aforedescribed ink absorber spring 22. The reference character 24g designates a waste ink tube formed integrally with the cylinder 24 and having its end portion cut an acute angle so that it may be readily inserted into a waste ink absorber which will be described later. The reference character 24b denotes an ink flow path formed in the waste ink tube 24g. The reference numeral 25 designates a cylinder cap which is forced into the end portion of the cylinder 24. The reference character 25a denotes a lever guide disposed at a location opposed to the cap lever receiver 24d of the aforedescribed cylinder 24. The reference numeral 26 designates a piston seal fitted in the cylinder 24 and having its inner diameter made somewhat small so that a predetermined pressure contact force may be provided with respect to a piston shaft which will be described later. Also, the surface of the piston seal may be lubricant-coated to as to reduce the sliding force of the piston shaft. The reference numeral 27 denotes a piston shaft formed with an operative shaft 27a, a piston keeper 27b, a piston receiver 27c, a connecting shaft 27d and a guide shaft 27e, and further formed with a groove 27f as an ink flow path along the connecting shaft 27d and the guide shaft 27e. The reference character 27g designates a key way formed as a groove in the operative shaft 27a. A bearing portion 27b is provided on the end surface of the operative shaft 27a. The reference numeral 28 denotes a piston. The body of the piston 28 which forms an inner layer as viewed from the cylinder sliding portion side is formed of an elastic porous material. As this material, mention may be made of a foamed material (such as sponge) having single-foamed pores or a porous material having continuous pores such as a continuous minute porous material, and preferably the latter, for example, urethane foam which is communication-foamed. Use may also be made of a material in which a plurality of continuous pores exist in a direction intersecting the direction of elastic deformation. The outer diameter of the piston is made larger by a predetermined amount than the inner diameter of the cylinder 24, and when the piston is inserted into the cylinder 24, the piston becomes moderately compressed. Also, the outer peripheral surface 28a of the piston 28 and the end surface 28b of the piston which bears against the piston keeper 27b of the piston shaft 27 are adapted to position a solid layer (a skin film) thereat during the foam formation of the piston. Here, even if the material forming the piston body is communication-foamed, the skin film does not liquid-communicate and air-tightness is kept and thus, the piston 28 performs that function. If use is made of a material having no skin film, a coating for keeping air-tightness may be provided separately. The reference numeral 42 designates a pump chamber. The reference numeral 29 denotes a piston pressing roller rotatably mounted on the end portion of the piston shaft 27. The reference numeral 30 designates a piston return roller also rotatably mounted on the end portion of the piston shaft 27. The reference numeral 31 denotes the shaft of these rollers. The reference numeral 32 designates a cap lever formed with a rotary shaft 32a, an ink guide 32b and a lever guide 32c. A convex spherically-shaped seal surface 32d is formed on the tip end portion of the cap lever. Also, engagement portions 32e adapted to be engaged by the pawl of a cap holder which will be described later are provided as a pair of upper and lower members. Further, an ink flow path 32f passes from the seal surface 32d through the interior of the lever, bends halfway at right angles, passes through the center of the ink guide 32b and opens to the end surface thereof. A cut-away 32g is formed in the lower portion of the ink guide 32b. The reference numeral 33 denotes a lever seal in which the ink guide 32b is fitted and which is forced into the cap lever receiver 24d. The reference character 33a designates a communication hole which communicates the cut-away 32g of the ink guide 32b with the ink flow path 24e. The reference numeral 34 designates a cap holder formed with a hook 34a at a location opposed to the engagement portion 32e of the cap lever 32 for engaging the engagement portions 32e. The reference character 34b denotes an opening for mounting a cap which will be described later. The reference numeral 35 denotes a cap formed with a hermetically sealing cap 35a for preventing the ordinary desiccation of ink, and also formed with a suction cap 35b adjacent thereto. A suction opening 35c is formed in the suction cap 35b, and bends the ink flow path in the cap and opens toward the cap holder 34 through the central portion thereof. The reference character 35d designates a flange portion which serves as slip-off preventing means when the cap is mounted on the cap holder 34. The flange portion 35d is formed with a concave spherically-shaped cap seal portion 35e having the same curvature as that of the seal surface 32d of the cap lever 32, and is designed such that when it is urged against the cap lever 32, only the central opening thereof communicates and the other portions thereof are sealed. The seal portions (32d, 35e) are spherically-shaped and therefore are excellent in the equalizing function for the cap member, and even where there is a level difference in the discharge opening forming surface (see Figures 24B and 24C), they can absorb the level difference on the spot to thereby keep a stable hermetically sealed state. Now, referring again to Figure 1, the reference numeral 36 designates a paper feeding roller for conveying a recording medium such as paper. The paper feeding roller 36 can be formed as by applying an elastic coating material (such as urethane resin) to the surface of a drawn tube of aluminum. Also, this roller 36 in its outer surface functions as a platen for controlling the recording surface of the recording medium, and the interior thereof is used as a reservoir for waste ink. The reference numeral 37 denotes a waste ink absorbing portion provided within the roller 36. The waste ink absorbing portion 37 is of a construction in which a thin tube formed of a plastic material such as vinyl chloride is filled with an absorbing material such as polyester cotton so as to ensure good axial absorption of ink. The waste ink tube 24g of the cylinder 24 is inserted in the waste ink absorbing portion 37 and fixed thereto. The fiber itself of the absorbing material may preferably be a non-liquid-absorbing material such as resin or a metal, but may slightly have a liquid-absorbing property. The reference numeral 38 designates a paper keep plate attached to the chassis 1. The reference numeral 39 denotes a paper feeding motor connected to the paper feeding roller 36 through a reduction gear mechanism of predetermined ratio. The reference numeral 40 designates a recording medium such as paper or film. The reference numeral 41 denotes a detector for detecting the home position of the carrier. In the present embodiment, the detector 41 is comprised of a transmission type photointerrupter. That is, the detecting piece 6b of the carrier 6 can interrupt the optical path to thereby detect the position of the carrier. The operation of the above-described construction will now be described. First, during the ordinary recording operation, the lead screw 2 is rotated by the rotation of the shaft of the carrier motor 11 through the timing belt 13 and therefore, the carrier 6 is scanned in the print column direction along the recording medium 40 by the lead pin 7 engaged with the lead groove 2a. Here, the carrier motor 11 is biased by the motor spring 14 and therefore, the timing belt 13 is always tensioned and good transmission is accomplished. An inertia force acts when the carrier 6 is started and stopped, but the weight of the carrier motor 11 provides inertia and therefore, the load of the motor spring 14 may be small and the load of the motor may also be small. Also, if an air damper, a hydraulic damper or the like is provided in connection with this spring, the noise by the vibration of the rotor of the motor 11 can be reduced when the carrier 6 is started and stopped. If the weight of this motor, the weight of the carrier portion and the coefficient of the motor spring damper are chosen appropriately, the overshoot of the rotor can be reduced and low noise can be accomplished. The operation of the present embodiment during non-recording will now be described with reference to Figures 5 to 9. Figure 5 is a timing chart showing the operation timing of each portion, and the operation timing of each portion as shown can be determined by a pulse number imparted to the motor 11. Figures 6A - 6C illustrate the successive operating conditions of each portion lying near the home position, Figures 7A - 7D illustrate the successive operating conditions of a mechanism concerned in the blade 17, etc., Figures 8A - 8C illustrate the successive operating conditions of a mechanism concerned in the cap 35, and Figures 9A and 9B illustrate the operation of a mechanism for introducing the waste ink into the waste ink containing portion 37 within the roller 36. The carrier 6 is first moved toward the home position (in the direction of arrow B), and detection is effected by the home position detector 41 (this position may be made coincident with the start position during the lap-up of recording). At this time, as shown in Figure 6A, the lead pin 7 is in engagement with the lead groove 2a and the discharge opening 9c of the head element 9a is in a position opposed to the ink carrier 19 (see Figure 7A). In this position, all of the discharge energy generating elements of the head element 9a are driven to effect the discharge operation (hereinafter referred to as the preliminary discharge), and the ink somewhat increased in viscosity is discharged by that discharging force, and the recovery operation by this preliminary discharge can be terminated. The preliminary discharge to be periodically effected to prevent the ink in the unused discharge opening from being increased in viscosity in the course of ordinary recording is also effected in this position. Figure 7A is a side view showing the vicinity of the same position. Further, when as shown in Figure 6B, the lead screw 2 is rotated to move the carrier 6 in the direction of arrow B, the clutch gear 4 is pressed by the pressing portion 6a and moved in the same direction B, and comes into meshing engagement with the driving tooth 21b of the timing gear 21. The clutch gear 4 is rotated in synchronism with the lead screw 2 and therefore, as the motor 11 is driven, the timing gear 21 is rotated in the direction of arrow D as shown in Figure 7B. On the other hand, the lead pin 7 comes from the introduction groove 3e into the cap groove 3c and therefore, the carrier 6 will not be moved even if the lead screw 2 is rotated. As the timing gear 21 is rotated in the direction of arrow D, the set lever 20 begins to pivot in the direction of arrow E because the gear portion of the timing gear is in meshing engagement with the gear portion of the set lever 20. Since until this time, the blade lever 16 has its hook portion 16c engaged with the pawl portion of the chassis, only the set lever 20 is rotated and the blade lever 16 is stopped, but soon the set surface 20f of the set lever 20 pivots in the direction of arrow F while depressing the pivotable piece 18a of the blade shaft 18 and therefore, the blade 17 is rotated in the direction of arrow G and set in a state in which it is engageable with the discharge opening forming surface. As the timing gear 21 is further rotated in the direction of arrow D, the set lever 20 and the blade lever 16 also are further rotated to thereby wipe the discharge opening forming surface of the head 9 as shown in Figure 7C. At this time, the ink liquid, etc. removed by the blade 17 are eliminated only in one direction, i.e., only downwardly in this case, and the ink liquid, etc. thus eliminated are absorbed or retained in the upper portion of the ink carrier 1a. Also at this time, the ink carrier 19 begins to contact with the ink absorber 23. When the set lever 20 is further rotated, as shown in Figure 7D, the ink carrier 19 and the blade 17 slide relative to the surface of the wiping portion 23a of the ink absorber 23 and therefore, the ink received by the ink carrier 19 during the preliminary discharge and dust or the like wiped off from the discharge opening forming surface by the blade 17 are received by the wiping portion 23a and ink droplets adhering to the discharge opening forming surface are also absorbed. Thus, the ink carrier 19 can maintain its ink absorbing ability for a long period of time. The timing gear 21 is further rotated in the direction of arrow D, but since the stop teeth 20a and 20b of the set lever 20 contact with the stop cam 21a of the timing gear 21 in opposed relationship with each other, the rotation of the timing gear is restricted and at the same time, any force rotating the timing gear does not act because the driving tooth of the timing gear 21 then corresponds to a cut-away portion. As described above, the blade and the absorber for retaining the ink liquid, etc. removed by the blade are identical to the ink receiver used during the preliminary discharge and therefore, the apparatus can be made compact and the time for the recovery operation can be shortened. When the timing gear 21 is further rotated, as shown in Figure 8A, the cap 35 is stopped at a position far from the discharge opening forming surface of the head element 9a because initially, the cap cam 21c controls the rotary shaft 32a of the cap lever 32c. Next, when the timing gear 21 is further rotated in the direction of arrow D, the cap comes off the cap cam 21c and therefore, the controlled state is released and thus, as shown in Figure 8B, the pivotable lever 24f of the cylinder 24 is biased by the spring portion 22b of the ink absorber spring 22 and the cylinder 24 is rotated in the direction of arrow F, and the hermetically sealing cap 35a of the cap 35 is urged against the discharge opening forming surface, thus terminating the capping operation. Figure 6B shows the then top plan view. At this time, the seal surface 32d and the cap seal portion 35e are also brought into intimate contact with each other by the pressing force of the cap and sealing is accomplished. Now, what has been described above is the wiping and capping operations for the nozzle surface and usually, the apparatus is stopped from operation here and the above-described operation is reversely performed in conformity with the inputting of the next recording signal, and the recording operation is entered. Description will now be made of the suction recovery operation performed as when the discharge condition does not become good even by the preliminary discharge. When this operation is to be started, the timing gear 21 is further rotated from the cap position, and the cap lever 32 is pressed by the cap cam 21b to thereby space the cap 35 apart from the discharge opening forming surface as shown in Figure 8C. The lead pin 7 then passes through the connecting groove 3d and shifts to the pump groove 3c and therefore, the carrier 6 is moved in the direction of arrow B by a predetermined amount (the distance between the cap groove and the pump groove). When the timing gear 21 is further rotated in the direction of arrow D, the cap again comes off the cap cam 21d and therefore, the cap 35 comes into pressure contact with the discharge opening forming surface. Since at this time, the recording head 9 has been moved, the discharge opening forming surface is capped by the suction cap 35b (see Figure 6C). In the present embodiment, as shown in Figure 6, the discharge opening 9c is biased toward the recording area side relative to the discharge opening forming surface, and during ordinary capping which does not involve suction, as shown in Figure 6B, the whole surface of the cap 35 is completely opposed to the discharge opening forming surface and therefore, the pressure against each rib portion of the cap decreases. At this time, however, the sealing property with respect to the outside air need only be kept and therefore, there is no hindrance to the prevention of desiccation, and the clearance can be hermetically sealed by a pressure force of the order of 10 g. Also, the collapse of the rib portions is little, and this leads to the advantage that the decrease in the volume in the cap may be slight and the retraction of ink meniscus during the capping does not occur. Further, as regards the capping during the recovery process, the cap portion usually comes off the discharge opening forming surface as shown in Figure 6C and therefore, pressure is applied to only the rib portion of the cap for recovery, and the sealing property is improved and thus, the prevention of leak by negative pressure becomes reliable. Even if at this time, meniscus is retracted by a decrease in the volume in the cap caused by the cap, meniscus is returned by the suction operation and therefore, no problem arises. Now, describing the pump operation, the suction operation is entered when the recovery operation is entered after the aforedescribed sealing cap is terminated. At this time, by the rotation of the timing gear 21, the piston set cam 21f first pushes the piston pressing roller 29 mounted on the piston shaft 27 and therefore, the piston shaft 27 is moved in the direction of arrow H as shown in Figure 9A. The piston 28 is pressed and moved in the direction of arrow H by the piston keeper 27b, and the pump chamber 42 assumes negative pressure. Since there is a skin layer on the surface of contact between the outer periphery of the piston 28 and the piston keeper 27b, ink does not leak through the communication hole in the foamed material. Also, since the ink flow path 24e in the cylinder 24 is closed by the piston 28, the negative pressure in the pump chamber 42 only becomes higher and the piston 28 remains movable. On the other hand, after the aforedescribed recapping, the ink flow path 24e opens as shown in Figure 9A and therefore, the ink in the head 9 is sucked from the suction port 35c of the cap 35 as shown in Figure 6C. The thus sucked ink passes through the ink flow path 32f formed within the cap lever 32, and through the communication hole in the lever seal 33 and further through the ink flow path 24e in the cylinder 24 into the pump chamber 42. When the timing gear 21 is further rotated, the cap 35 again becomes somewhat spaced apart from the discharge opening forming surface by the cap cam 21e, and the ink in the discharge opening forming surface and the suction cap 35b is sucked by the residual negative pressure in the pump chamber, whereby the remaining of the ink in these portions is eliminated. Next, when the timing gear 21 is rotated in the opposite direction (the direction indicated by arrow I in Figure 7D), the piston reset cam 21g pulls the piston return roller 30 and moves the piston shaft 27 in the direction of arrow J as'shown in Figure 9B. At this time, the piston 28 is moved after it is contacted by the piston receiver 27c of the piston shaft 27 and therefore, a gap Δℓ is creased between the end surface 28b of the piston 28 and the piston keeper 27b. Thus, by the movement of the piston shaft 27 and the piston 28, the waste ink sucked into the pump chamber 42 passes through the aforementioned gap Δℓ and through the groove 27f of the piston shaft and through the ink flow path 24c in the cylinder 24 and further through the waste ink tube 24g and is discharged to the vicinity of the center of the waste ink absorber 37. At this time, the waste ink does not flow back toward the cap because at the early stage of the operation of the piston 28, the ink flow path 24e in the cylinder 24 is closed by the piston 28. Figure 10 collectively shows the sequence of the above-described preliminary discharge to the suction recovery, and more particularly shows the sequence in which the blade 17 stands by in a state in which it is capable of wiping (the set state, see Figure 7B) and after the wiping, the blade 17 becomes inclined with respect to the absorber 23 (the reset state, see Figure 7A), whereafter the blade 17 is brought into a set state in which it is capable of wiping immediately before the set lever 20 is returned to its original position. The present invention is not restricted to the above-described construction, but can adopt various constructions, so other constructions or forms of various portions will be shown below by way of example. Figure 11 shows another form of the blade and ink carrier portion. This ink carrier body 119 is formed of an elastic material such as rubber, and an ink receiving portion 119a performing the same function as the above-described ink carrier 19 is formed with a number of grooves or concavo-convexities. The ink receiving portion 119a retains ink by the surface tension thereof and carries the ink to the ink absorber 23. The ink carrier body 119 has formed integrally therewith a blade 119b for wiping the discharge opening forming surface 9a of the head 9. According to this, the ink carrier body 119 can be provided directly on the set lever 20 and therefore, the blade lever 16 becomes unnecessary and thus, the number of parts can be reduced to make the apparatus inexpensive. Also, where the direction of discharge is made downward, the ink on the discharge opening forming surface when wiped by the blade 119b is received by the grooves or the concavo-convexities and does not flow out to other mechanism portions and thus, contamination or the like of the instrument can be prevented. Figure 12 shows still another form of the blade and ink carrier portion. In this case, an ink carrier 219 is elongated and made integral with an ink absorber 219c, and in this case, the material forming the ink carrier may preferably be bendable woven cloth or laminated paper. In the present case, the aforedescribed ink absorber 23 and the holding member therefor become unnecessary and moreover, it becomes possible to dispose the blade and ink carrier portion broadly in the lower portion of the chassis and therefore, this construction is also suitable for an instrument in which the amount of ink preliminarily discharged is great. Figure 13 shows another form of the piston portion. A piston 128 according to the present embodiment is designed such that a skin layer 150 is not present on the end surface thereof, and a piston keeper 127 is provided with a flange portion 151 as shown and the piston 128 is held in its squeezed state. Not only air-tightness can be kept by such a construction, but also the piston 128 can be manufactured by cutting a long piston blank and therefore, the cost thereof can be made lower. Figure 14 shows still another form of the piston portion. This piston 228 is formed by a plate-like member. Such a piston can be simply manufactured by being shielded in the direction of the thickness of a skin layer 253 and pressed and therefore, the cost of manufacture thereof can be made still lower. Figure 15 shows another form of the rear portion of the cap 35. This form is such that a rib 35e is provided on the seal surface 35d and air-tightness can be further secured by the deformation of the rib portion. Figure 16 shows still another form of the rear portion of the cap 35. This form is provided with a spherically-shaped seal portion 35d and a protective seal portion 35f covering it. This can prevent ink or dust from adhering to the aforedescribed spherically-shaped seal portion 35d when the latter is not capped, and deteriorating the sealing performance thereof. Figure 17 shows yet still another form of the rear portion of the cap 35. In this case, a spherically-shaped seal 350 is provided on the connecting portion between a cap lever 332 holding the cap 35 and the cylinder 24 of the pump, and all the seal portions of the ink flow path are pressed by the same spring force to thereby accomplish sealing. According to this, the operational force of the entire recovery system can be reduced. Figure 18 shows another form of the waste ink containing portion disposed within the roller 36 which is conveying means. In this case, a guide member 160 is mounted on the end portion of a waste ink absorber 137. According to this, the frictional force on the inner surface of the paper feeding roller 36 can be reduced to thereby reduce the load of the paper feeding motor 39. Figure 19 shows still another form of the waste ink absorbing portion wherein a hollow shaft 261 extends through the central portion of a waste ink absorber 237 and openings 262 and 263 are provided in the end portion and the central portion, respectively, of the hollow shaft 261. The reference numeral 264 designates a lid. In the present case, waste ink passes through the hollow shaft 261, and the hollow shaft 261 can be endowed with a function as the guide shaft of the paper feeding roller 36. In this case, there is no sliding portion in the paper feeding roller and the load of the paper feeding motor is further reduced. In the present case, a main ink discharging portion 263 is provided in the central area of the platen roller as viewed in the lengthwise direction thereof, but a second ink discharging portion and a third ink discharging portion may be provided upstream and downstream, respectively, of the discharging portion 263 with respect to the ink guide member. Also, a construction may be adopted in which the size of the former is smaller than that of the discharging portion in the central portion and the size of the latter is larger than that of the discharging portion in the central portion. Figure 20 shows yet still another form of the waste ink absorbing portion. In this case, when a waste ink absorber 337 is to be manufactured, a tube 365 for waste ink is put into the center of a blank 337' and is cut, whereafter this tube 365 is half drawn out and connected to a pump for recovery. This can eliminate the difficulty with which a member having no rigidity such as a flexible tube is inserted to the vicinity of the center. At this time, one half of the waste ink absorber 337 remains as the tube is drawn out, but where polyester cotton or the like is used, the waste ink absorber is sufficiently compressed and therefore the hole is closed. The waste ink absorbing portion is provided within the roller-like conveying means as described above, and besides, can be provided at a suitable region within the conveying means depending on the construction thereof. For example, where the conveying means is constituted by a plurality of rollers and a belt passed between the rollers, the waste ink absorbing portion may be provided in the space defined by the rollers and the belt. Figure 21 shows another form of the cap 35. In this case, a hermetically sealing cap portion 135a is a planar member so that the discharge opening forming surface may not be contacted by air, and the hermetically sealing effect is further enhanced. Also, ink flows out of the discharge opening due to the surface tension of the ink and around the cap, the ink is contacted by the outside air and therefore, an increase in the viscosity of the ink or the adherence of the ink occurs in this portion, that is, occurs in the other portion than the discharge opening and thus, it becomes difficult for any problem to arise in the recording operation after the cap is opened. Figure 22 shows still another form of the cap 35. In this case, a hermetically sealing cap 235a is formed of a single-foamed porous block such as urethane foam, and the intimacy of contact with the unevenness of the discharge opening forming surface is improved and the pressing force of the cap can be reduced. Figure 23 shows yet still another form of the cap 35. In this case, a skin layer 335b lying on the body of a hermetically sealing cap portion 335a in the form of continuously foamed urethane foam is formed on the surface which is in intimate contact with the nozzle, and the cap performance is ensured for a long period of time by the stability of the restitution coefficient which is the characteristic of continuously foamed urethane foam. Figure 24A shows another form of the blade. This form, as shown in Figure 24B or 24C, has a level difference on a surface 9d in which the discharge openings 9c are formed, and is also effective for wiping the surface at the inner side thereof. That is, in the present case, short fibers 117a of a high molecular material are electrostatically attracted and thereby planted onto the whole surface of the blade 117 or a portion thereof which contacts with the nozzle surface, and this embodiment not only can wipe by the planted hair touching the surface at the inner side, but also can effectively remove elongate dust such as threadlike dust. Figure 25 shows still another form of the blade. In the present case, a blade 217 is in the form of a brush which can be formed by bundling fibers 217b of a high molecular material such as plastic. This form has a great wiping effect even in a case as shown in Figure 24B or 24C wherein the groove in the discharge opening forming surface having a level difference as shown in Figure 24B or 24C is deep, and since each fiber contacts with the surface to be wiped, the pressure contact force as a blade for the discharge opening forming surface may be small, and it will never happen that the durability of a surface treating layer of a water repelling agent or the like which may sometimes be applied to the discharge opening forming surface is spoiled. Finally, modified forms of the piston 28 to be applied to Figs. 9A and 9B are shown in Fig. 26 to Fig. 28. The piston 28 of the pump means having the effects of miniaturization and ink thickening prevention effect as described with reference to Figs 9 A, B is made to have a constitution in which the annular contact portion, which blocks the route for discharging ink in the adulation according to suction through contact, and forms the route for said discharging in the actuation according to discharging through separation, is provided on either the end surface of the piston or the end surface of the pushing member which pushes the end surface in the suction actuation. In Fig. 26, 28c is a seal rib provided on one end surface 28b of the piston 28 concentrically with the same end surface, of which lateral cross-section is semispherical. The seal rib 28c is the site which contacts directly the piston presser 27b when the piston 28 and the piston presser 27b actuate with engagement, and its sealability becomes better through contact along a line as a whole, and also can be rapidly separated from the piston presser without influence from the viscosity of the ink. Fig. 27 is a perspective view of another form of the piston 28. As shown in the same Figure, in this case, in addition to the seal rib 28 at the end surface 28b, a seal rib 28f is provided at the peripheral portion thereof. In this way, sealability in valve action during ink suction is improved. Fig. 28 is a side sectional view showing the engaged state of another form of piston presser and piston. As shown in Figure 28, in this case, an annular seal rib 27c is provided on the end surface of the piston presser 27b, and the end surface of the piston 28 is made flat. Since the rib 27c contacts the end surface of the piston 28 when the piston 28 is pushed through the piston presser 27b, the amount of the rib 2c bitten onto the end surface can be small, whereby the positional relationship during piston actuation can be stabilized. In the suction pump constituting the valve function by use of the end surface of the piston, through contact between the end surface of the piston and the end surface of the pushing member at an annular line, sealability becomes better in blocking the exhausting route during suction, and also a exhausting route can be formed by rapid separation regardless of the viscosity of the ink during exhausting. As the result, suction and exhausting actuations of the pump can be done well. Also, defective phenomenon such as impairment of the actuation of pump through attachment of ink, grease or dust, etc. on the contact portion will occur with difficulty, and further no counterflow of ink toward the recording head side is generated during discharging, whereby a suction pump and an ink jet recording apparatus of high reliability can be obtained. The above constitutions of the respective parts can be combined adequately based on the technical contents as described above in giving rise to miniaturization, high precision, high effect of the present invention, and these are included within the scope of the present invention. The recording head may have the above-described structure wherein the flow passage is linear and the liquid is ejected in the direction from one edge of the heater to the other edge, in the structure where the liquid passage is bent at the position of the electrothermal transducer to eject the liquid in the direcion perpendicular to the surface of the electrothermal transducer element, or the structure wherein the passage is bent at an angle not 90 degrees as disclosed in U.S. Patents Nos. 4,558,333 and 4,459,600. Also, the present inventon is applicable to the structure disclosed in a Japanese Laid-Open Patent Application 59-123670 wherein a common slit is formed to provide the ejecting portions relative to the plural electrothermal transducers or to the structures disclosed in Japanese Laid-open Patent Application 59-138461 wherein the pressure wave produced by the thermal energy is absorbed by an opening provided for the ejecting outlet. The present invention is also applicable to the recording substrate, recording head or the recording apparatus for multi- or'full-color recording apparatus wherein plural recording heads are used in combination or as a unit.

Claims: An ink jet recording apparatus comprising: a moving means (2,11,6) for moving a recording head (9) having a discharge port surface with a plurality of discharge ports to cause the recording head to scan a recording area and a non-recording area; a cleaning member (17) for cleaning the discharge port surface of the recording head; a contact member (23) for contacting the cleaning member (17) after a cleaning operation, characterised by : control means (21,20,16) for controlling the cleaning member to effect reciprocal movement in a direction in which the discharge ports are arranged, the control means being arranged, when said recording head (9) is at said non-recording area, to cause the cleaning member (17) to carry out a cleaning operation by causing the cleaning member (17) to move from a first position to a second position to clean said discharge port surface and to allow ink adhering to the cleaning member (17) to be removed by the contact member (23) after the cleaning member has cleaned the discharge port surface, the control means also be arranged to cause the cleaning member (17) to return from said second to said first position without cleaning the discharge port surface of said recording head after said recording head has been moved by said moving means (11,16) from the non-recording area to the recording area. An ink jet recording apparatus according to claim 1, wherein said contact member (23) is an ink absorbing member. An ink jet recording apparatus according to claim 1 or 2, wherein said cleaning member (17) is arranged to clean a cleaning area corresponding to a returning area of the scan of said recording head (9) by said moving means (11,6). An ink jet recording apparatus according to claim 1, 2 or 3, wherein said cleaning member (17) is movably provided with respect to a member (20) for mounting said cleaning member. An ink jet recording apparatus according to claim 1, 2 or 3, wherein said cleaning member (17) is fixedly provided with respect to a member (20) for mounting said cleaning member. An ink jet recording apparatus according to any of the preceding claims, comprising the recording head (9) and wherein said recording head (9) has electrothermal converting members for generating thermal energy utilized for discharging ink from said discharge ports. A method of operating an ink jet recording apparatus having: a moving means (8,11,6) for moving a recording head (9) having a discharge port surface with a plurality of discharge ports to cause the recording head to scan a recording area and a non-recording area; a cleaning member (17) for cleaning the discharge port surface of the recording head; a contact member (23) for contacting the cleaning member after a cleaning operation, the method being characterised by comprising the recording apparatus controlling the cleaning member (17) to effect reciprocal movement in a direction in which the discharge ports are arranged so that when said recording head (9) is at said non-recording area, the cleaning member (17) moves from a first position to a second position to clean said discharge port surface and to allow ink adhering to the cleaning member (17) to be removed by the contact member after the cleaning member has cleaned the discharge port surface and after said recording head (9) has been moved by said moving means from the non-recording area to the recording area the cleaning member returns from said second to said first position without cleaning the discharge port surface of said recording head.

Inventors: HIRANO HIROFUMI, SUGIMOTO HITOSHI, HIRANO, HIROFUMI, SUGIMOTO, HITOSHI, HIRANO, HIROFUMI, CANON KABUSHIKI KAISHA, SUGIMOTO, HITOSHI, CANON KABUSHIKI KAISHA
Applicants: CANON KK, CANON KABUSHIKI KAISHA
Application year: 1989
Main classification: B41J2
IPC codes: B41J2