Source: https://patents.google.com/patent/EP0684139A1/en
Timestamp: 2018-10-17 03:30:27
Document Index: 200593793

Matched Legal Cases: ['Application No. 56', 'Application No. 60', 'Application No. 56', 'Application No. 59', 'Application No. 59', 'Application No. 54', 'Application No. 60', 'art.\n1']

EP0684139A1 - Ink supplying device and ink jet recording apparatus using the same - Google Patents
Ink supplying device and ink jet recording apparatus using the same Download PDF
EP0684139A1
EP0684139A1 EP19950110640 EP95110640A EP0684139A1 EP 0684139 A1 EP0684139 A1 EP 0684139A1 EP 19950110640 EP19950110640 EP 19950110640 EP 95110640 A EP95110640 A EP 95110640A EP 0684139 A1 EP0684139 A1 EP 0684139A1
EP19950110640
EP0684139B1 (en )
Atsushi C/O Canon K.K. Saito
Akio C/O Canon K.K. Ohkubo
Fumihiko C/O Canon K.K. Watanabe
Yasuyuki C/O Canon K.K. Shinada
An ink cartridge adapted to be loaded detachably to an ink jet recording apparatus for preforming a recording on a recording medium by discharging ink comprises an ink tank for accommodating ink therein, leading-out means for leading out ink within said ink tank to the outside, said leading-out means being provided on said ink tank, and a frame for supporting displaceably said ink tank on which said leading-out means is provided. Also, an ink jet recording apparatus for preforming a recording on a recording medium (1) comprises a recording head (38) for discharging ink from a discharge port to carry out the recording on the recording medium (1), a loading part for loading therein an ink cartridge, said loading part having an ink tank for accommodating ink therein, leading-out means for leading out ink within said ink tank to the outside, said leading-out means being provided on said ink tank and a frame for supporting displaceably said ink tank on which said leading-out means is provided, and ink supplying means (G) for supplying ink to said recording head (38) by coupling to the lead-out means of said ink cartridge which is loaded in said loading part.
The present invention relates to an ink supplying device and an ink jet recording apparatus having such ink supplying device.
Recently, it has been recognized that an ink jet recording apparatus is excellent in that it can perform a high speed recording since a noise during the recording is very small and it can be easily constructed as a high density multiple discharge port type ink jet printer. Further, it has been interested in that the ink jet printer has good color reproducibility for a color image. In general, an ink jet recording system (ink jet recording apparatus) is so constructed that ink droplets are caused to be discharged and fly from a discharge port of a recording head, and recording is carried out with their sticking on a recording sheet. So, in the ink jet recording apparatus, it is needed to supply surely ink to the ink jet recording head. In the past, various contrivances have been made for this purpose.
Hereinafter, its several examples and related problems will be explained. First, an example which employs an exchangeable ink tank is described. In the past, there have been developed many arrangements which are provided with a cartridge type ink tank in the ink jet recording apparatus permitting easy supplement of ink by exchanging the ink tank by a user when ink has been lost. As for the cartridge, type ink tanks, an arrangement is widely known wherein it is provided with a flexible bag which accommodates ink therein and which is caused to have both of opening to the air pressure and evaporation preventing at the same time, as shown in Japanese Laid-Open Patent Application No. 56-41148, for example. This arrangement is very effective as means for forming a low-priced and compact ink tank since it need no additional complicated mechanism for communicating to the air.
Also, as for positioning and alignment means for a joint part for conducting out ink from the ink tank, a method is known of obtaining a sure connection of the flow path with the connecting portion of the ink cartridge side by causing the member of the device side to have a degree of freedom, as shown in Japanese Patent Laid-Open Application No. 60-137658.
However, in the above-mentioned prior art connecting arrangement, it can be easily constructed in a case where the flow path to be connected is one, but in an arrangement having a plurality of flow paths or connecting portions, moving parts at the device side must be large in size, or its construction becomes very intricate, and thus, in a case where a plurality of ink paths are used, for example, seal portions for connecting portions between the joint portions of the device body which are movable and the ink paths to the recording head must be increased in number, or distribution of tubes forming the ink paths would become complex.
On the other hand, the above-mentioned cartridge type ink tank arrangement is weak in vibration and shock because it holds ink with a soft bag, and if the manners in which the bags collapse are nonuniform, then the pressure with which ink is let to flow would be often caused to change. Accordingly, this arrangement is not suitable to a large volume ink tank, and in fact it is realized as a relatively small ink tank.
In order to overcome the above problems, an ink tank shown in Japanese Laid-Open Patent Application No. 56-13456, for example has been developed, which has a construction which is strong in vibration and shock and permits it to be voluminous by holding ink between the outside of the bag which communicates to the air and a frame. However, the problem relating to the change of the pressure with which ink flows out, which is due to a difference between the manners in which the bags collapse (or swell) is not solved entirely, and it is needed to cause ink to flow out compulsively with an ink pump, store ink temporarily in a sub-tank which is provided with special means communicating to the air and then supply it to the head, so as thereby to carry out stabilized ink supplying.
Moreover, an ink cartridge is also known having its construction wherein a waste liquid absorbing body is added to the ink tank of the above-mentioned arrangement and the ink tank and a waste liquid tank are made to be in a body by enclosing them with a frame, between which a member intervened. In the ink cartridge of this type, as the waste liquid absorbing body, in general, felt or foaming resin, etc. is used to hold therein waste ink for the collection thereof. However, in this prior art, such a problem would be produced that in the case where, for example, the weight of the ink tank with ink filled up is larger than that of the waste liquid tank, rubbing is produced between the ink tank and the frame enclosing it, and specially, if the tank is made in the form of a rigid container having the means communicating to the air rather than the bag, then because of backlash between the tank and the frame, a noise would be generated at the time of the application of vibration and a damage would occur at the time of the application of shock.
Accordingly, an object of the present invention is to provide an ink supplying device wherein recording can be continued suitably, and an ink jet recording apparatus using this ink supplying device.
A further object of the present invention is to provide an ink supplying device wherein ink can be supplyed suitably, and an ink jet printing apparatus using this ink supplying device.
Another object of the present invention is to provide an ink supplying device wherein connection between an ink cartridge and the device body can be carried out easily and reliably, and an ink jet printing apparatus using this ink supplying device.
Still another object of the present invention is to provide an ink supplying device wherein the protection for an ink cartridge is made surely, and an ink jet recording apparatus using this ink supplying device.
Figs. 11 A and 11B are views showing the state where the head and the cap are apart from each other.
Figs. 13A - 13C are views showing the state where a projection presses a nozzle to be tightly closed while a spring resiliently deformed.
Research was made by the inventors of this invention to resolve the above-mentioned problems raised in the prior art, and as a result thereof, it could be found that with such a construction that connecting portions of the device side are stationary and the corresponding connecting portions of the ink cartridge side are movable, the connection therebetween can be carried out suitably. The present invention which will be explained hereinafter was made on the bases thereof, and relates to a ink jet recording apparatus comprising ink supplying means for permitting the supply of ink to an ink jet recording head and an ink cartridge detachably mounted on said ink supplying means and providing with an ink tank accommodating therewithin ink to be supplied, said ink supplying means having a stationary ink supplying side joint portion adapted to be connected to said ink tank, said ink tank within said cartridge having an ink tank side joint portion connected to said ink supplying side joint portion and supplying ink, and said ink tank having a freedom of motion in the rotation direction with respect to the central axis of its joint portion to permit said ink tank to displace when said ink supply side joint portion and said ink tank side joint portion are connected to each other.
In accordance with this invention, the ink container is retained movably within the frame enclosing it, specially in the direction of its rotation with respect to the central axis of the connecting portion (joint portion), and thus, a freedom in connection of the connecting portion of the device side and the corresponding connecting portion of the ink cartridge side is easily secured, and even though there are provided a plurality of flow paths to be connected, the positioning of the device side joint portions to the ink container side joint portion is made easily and surely.
Also, since the joint portion of the device side (ink supplying means side) is made to be stationary, the distribution of the ink tube form here to the recording head can be made to be compact and simple.
Further, the inventors of this invention studied a construction with which ink is supplied suitably from a voluminous ink tank to the recording head directly without the use of any sub-tank, and as a result thereof, obtained a construction defined by the following. That is, this invention relates to in an ink supplying device having a plurality of ink paths adapted to be connected to an ink jet recording head, joint means comprising a first ink coupling portion connected to said ink jet recording head through an ink pump, a second ink coupling portion different from said first ink coupling portion and connected to said ink jet recording head, and a connecting portion for performing communication to the air, whereby an ink tank with said portions is detachably mounted to said ink jet recording head.
Therefore, in accordance with the above mentioned construction, the ink supply can be carried out very suitably without the use of not only the ink bag but also the sub-tank since the ink supporting port is jointed directly to the member constituting the ink supplying path. Also, since the port of the ink tank opening to the air is joined to the connecting portion for performing the communication to the air so that the ink tank can be caused to communicate to the air, it is possible to provide the ink tank which does not request that it be in the form of the above-mentioned bag arrangement, which is strong in vibration and shock and which is voluminous. avoidable that the recording becomes inactive under a predetermined number of recording papers.
Fig. 1A is a central sectional view showing an embodiment of facsimile apparatus characteristically representing the present invention. Fig. 1 B is a top plan view thereof, and Fig. 2 is a cross-sectional view showing the apparatus in an open state. The facsimile apparatus of the present embodiment roughly comprises original conveying system A, optical system B, power source unit C, electric circuit board D, recording sheet conveying system E, decurling system F, ink supply system G, and recovery system H. Here, aforesaid original conveying system A and optical system B constitute an original reading unit for reading original images. Then, as the basic action of a facsimile apparatus, when an original 2 is set for transmitting or copying, original coveying system A conveys the aforesaid original 2 sequentially by a roller train (rollers R1, R2, R3, and R4) driven by driving means (not shown) in order to read the original image of original 2. Thus, the original line information is transferred by condenser lens Le to line CCD 100 through the reflective optical path of optical system B (lamp L1, mirrors M1 and M2) from a given position for reading the original line (main scanning line) in the course of its conveyance, and is converted into electrical signals for the reading of the original information. At the time of receiving or copying, recording sheet conveying system E sequentially conveys recording sheet, which is wound in roll, by a roller train driven by driving means (not shown) to a passage shown in Fig. 1, and recording is performed in the course thereof by discharging ink from discharging ports of recording head 38 onto a given recording line of the recording sheet. Ink is discharged from the discharging ports of recording head 38 with the utilization of heat energy. This heat energy is generated by an electric heat converter provided in recording head 38. In this respect, power source unit C received a normal AC to convert it into all the necessary voltage currents and supplies them respectively to each of the units of the apparatus. The electric circuits with electric circuit board D at its center controls the functional operation of each unit of this apparatus mainly with a cimcrocom- puter system provided. It also performs the connection and disconnection with transmission line as well as the input and output of image information signals. Ink supply system G supplies ink to the recording head, and recovery system H performs the cleaning and capping of the face of discharging ports, which are needed for the maintenance of the head.
In this respect, as shown in Fig. 1 B, rolled recording sheet 1 is positioned almost in the center of the apparatus, and on the left-hand side thereof, original conveying system A, optical system B, and power source unit C are arranged in the vertical direction, and on the right-hand side thereof, recording head 38, record head recovery system H, and ink supply system G with ink tank 86 are arranged sequentially in that order from the above. Since recording head 38, recording head recovery system H, and ink supply system G are thus arranged sequentially from the above, the ratio of pressure variation of ink tank 86 against the orifice face of recording head 38 is reduced (i.e., the pressure against each of the discharging ports is equalized) even if the apparatus is inclined according to the present embodiment, and an excellent recording can be performed. This is due to an arrangement such that despite the miniaturization of the apparatus, the space between the orifice face of recording head and the ink tank 86 is made greater.
Here, Fig. 3 is a perspective view showing parts arranged in the longitudinal direction in the vicinity of free roller 8 (platen roller). A first platen side plate 13a and a second platen side plate 13b fixed to or integrally formed with recording frame 19 support free roller 8 with a play in such a manner that the shaft of the free roller is penetrated through the opening 13c provided each of the side plates, having a larger diameter than that of the shaft. The E rings 29 and 30 are fixed respectively at both ends of the shaft of free roller 8 as locks and further, on both shaft parts of free roller 8, bearings 10a and 10b, the inner and outer diameters of which are accurately regulated to provide an equal coaxiality, are fittedly mounted on the shaft of free roller 8 to enable it to be freely rotated. In the meantime, the aforesaid first platen side plate 13a and second platen side plate 13b are slidably arranged each with the respective platen pressure shaft 12a and 12b mounted on the inner side thereof as shown in Fig. 3. Then, by the functions of springs 11 a and 11 b, the aforesaid platen pressure shafts 12a and 12b are in contact with bearings 10a and 10b of the aforesaid free roller 8 respectively to exert pressure against each of them.
Next, recording sheet 1 is pinched by first exhaust sheet roller 21 and the roller train 17a - 17g and roller train 18a - 18g which are in contact with the aforesaid first exhaust sheet roller 21 to be conveyed while being guided by first curvature guide 15 and first exhaust sheet guide 20.
Here, Fig. 4 is a perspective view showing the parts arranged in the longitudinal direction in the vicinity of first exhaust sheet roller 21. Rollers 17a - 17g and roller 18a - 18g are arranged alternatively with first curvature guides 15a - 15f. Each of them is rotatably supported by shaft 31 and shaft 32 and both ends of the shafts are locked by E rings, etc. Also, at both ends, shaft 32 is regulated by receiving side 9a of the first exhaust sheet rollers, which is fixed to or integrally formed with recording frame 19 and receiving side 19b of the second exhaust sheet rollers, and also in the horizontal direction, the shaft is regulated at both ends thereof by the vertically elongated through holes having the diameter fitted to that of shaft 32, through which the shaft is penetrated. The both ends of the shaft are also locked by E rings (not shown), etc. In this respect, compression is generated by springs 16a - 16f represented only by a reference numeral 16a in Fig. 4 for recording chassis 19 and first curvature guides 15a - 15f (refer to Fig. 1) to cause rollers 17a - 17g and roller 18a - 18g to be in contact with exhaust sheet roller 21 by pressure. As a result, when recording sheet 1 is pinched thereby, the power to convey the recording sheet is generated. Then, recording sheet 1 is guided to upper exhaust sheet guide 23 and trailing exhaust sheet guide 24 through the space between both edges 22a and 22b which cut the recording sheet into each of the receiving one pages and is further guided and conveyed by second exhaust sheet roller 25 and the rollers 27a - 27g and rollers 28a - 28g which are in contact therewith. In this respect, second exhaust sheet roller 25 is also driven by the driving system in such a manner that the peripheral speed thereof is set at a speed slightly faster than that of the aforesaid first roller 21. Here, too, as in the vicinity of the aforesaid first exhaust sheet roller 21, rollers 27a - 27g and rollers 28a - 28g are arranged alternately with second curvature guides 26a - 26f and are rotatably supported respectively by shaft 33 and shaft 34. Then, both ends of shaft 34 are locked with E rings, etc. Shaft 33 is regulated at both ends thereof by exhaust sheet roller receiving sides 19c and 19d fixed to or integrally formed with recording frame 19, having vertically elongated holes fitted respectively to the diameter of shaft 33, through which both ends of the shaft are penetrated horizontally. The ends thereof are also locked by E rings, etc. With springs 35a - 35f, compression is generated between recording frame 19 and second curvature guides 26a - 26f (refer to Fig. 1) to cause rollers 27a - 27g and rollers 28a - 28g to be in contact with second exhaust sheet roller 25 by pressure, so that when recording sheet 1 is pinched thereby, the conveying power is generated. In this way, the recording sheet is exhausted after recording has been completed, and is further conveyed by exhaust sheet roller 39 in the form of being cut into the unit of one page while the leading and thereof is being held smoothly by stacker 40. As a result, an operator can take out the recording sheet thus stacked on stacker 40.
First, Fig. 6 illustrates the state of parts in the vicinity of free roller 8 when the main body of the apparatus is in standby. Recording guide 14 is not allowed to be in contact with free roller 8 unless there is external force to be exerted thereon. Accordingly, the contacting angle of recording sheet 1 to the periphery of free roller 8 is less in the standby state than in the printing state. At this juncture, the position of free roller 8 is established by the fact that the periphery of free roller 8 is pressed by platen pressing shafts 12a and 12b to be in contact with feed roller 7, and that the shaft of free roller 8 is in contact with through hole 13c, which is larger than the periphery of the aforesaid shaft by 0.1 mm - several mm, provided on each of platen side plates 13a and 13b. Here, the aforesaid feed roller 7 and free roller 8 are made of plastic material such as rubber, etc. rolled around rigid shaft made of iron, etc.
Next, Fig. 7 illustrates recording head 38 being rotated clockwide with head shaft as its rotating center in order to shift itself from the standby state to recording state. When head 38 is first rotated as described earlier by the driving power generated by motor KM, a plurality of projections provided on the recording face of head 38 are in contact with the top of recording guide 14 to cause recording guide 14 to begin resiliently deforming it. Here, projection 38c provided on the recording face of head 38 is made to be increasingly higher towards the corner. Thus, recording guide 14 is deformed apart from recording head 38 by the height (8 in Fig. 7) of the aforesaid projection.
The reason why the aforesaid projection 38c is arranged to be increasingly higher towards the coner is to make it easier to remove ink when the recording face of the head is wiped as described later.
Recording head 38 is further rotated clockwise, and when recording head 38 is moved to be in the recording state as shown in Fig. 1, both ends of the recording face of recording head 38 are in contact with bearings 10a and 10b. Hence, the space between the recording face of recording head 38 and platen roller (free roller) 8 is established. In the present embodiment, the periphery of bearings 10a and 10b is made larger than that of free roller 8, and the volume thereof is set to be less than the height 6 of the aforesaid projection of recording head 38 by a 1/several mm thereof. Thus, guide 14 is reliably in contact with the periphery of platen roller 8 to convey the recording sheet. Here, at the time of recording, the aforesaid feed roller 7 is rotated clockwise, and platen roller 8 is rotated counterclockwise by the external force generated by the feed roller, at the same time, being moved in the direction towards the recording head 38. Hence, with the structure described earlier, the aforesaid platen roller 8 is brought to contact with guide 14 through recording sheet. Therefore, the aforesaid springs 11 a and 11 are not necessarily needed here, and platen roller 8 can also be incon- tact with the guide only by its own weight.
Next, using the perspective view shown in Fig. 8, the structures of peripheral parts of recording head 38 will be described. Recording head 38 mainly comprises head main body 38f including a heat generating section, electrical part section, and glass chamber section for containing liquid ink, front filter 38d and rear filter 38e arranged respectively at the outside of the head main body, and head front plate 38c. Also, front head ink connection 38d, and rear head ink connection 38e, are respectively provided for front filter 38d and rear filter 38e. These are tightly closed and connected respectively by front ink supply 71 and ink supply tube threading with sealing members (not shown) provided therebetween. A reference numeral 38a designates an imaginary two-dot chain line in Fig. 8 to represent the straight line formed by connecting the center lines of the nozzles aligned. A plurality of nozzles are aligned in order to form image on a recording material across the entire width thereof in the direction of main scanning. Hereinafter, these are referred to as nozzle 38a. In practice, however, holes of several ten microns in diameter are provided, and the aforesaid holes are connected to ink supply tubes 71 and 72. Here, the opposite ends of ink supply tubes 71 and 72 are respectively connected to front supply tube joint 84 and rear supply tube joint 85. Now, in Fig. 8, a reference numeral 38b designates the face where nozzle 38 is open, which is called orifice face. In this respect, front head plate 38g is formed by metal or molding material, and the space between orifice face 38b and front head plate 38g is filled with silicon rubber, etc. to close them completely. Filters 38d and 38e are arranged to prevent dusts in ink from being flown into the nozzle section. Reference numerals 37a and 38b designate front and rear head arms made of engineering plastic, sintered metal, diecast metal, or the like, which has rigidity and resistivity against thermal deformation at high temperatures, and each of them is fixedly mounted on BJ head 38 by means of screw, etc. Front head arm 37a and rear head arm 37b are fixedly mounted on head shaft 36 by means of screw, etc., and with the structure as described earlier, head shaft 36 and BJ head 38 are fixed arranged. Head shaft 36 is rotatably supported by main body frame 56 through bearings (not shown). Head shaft 36 is connected to driving system comprising gears, belts KB, etc., and is further connected to stepping motor KM.
Next, using the perspective view shown in Fig. 9, the structure of peripheral parts of cap 41 will be described. Although the shape of cap 41 will be described later in detail later, cap 41 is formed by plastic material such as silicon rubber, etc. which has a high resistivity against mechanical creep as well as a high ratio of permeability for water vapor, etc. A reference numeral 42 designates a cap keel made of rigid material such as aluminum, stainless steel, etc., and as shown in a cross-sectional view in Fig. 10, short shafts 46a, 46b, 46c, 46d, and 46e are fixedly mounted on cap keel 42 by means of screws. Short shafts 46a - 46e should desirably be made of a corrosion-inhibiting and rigid material such as stainless steel, etc. In the present embodiment, although short shafts 46a - 46e are fixed by screws, these can also be coupled by means of press fitting, bonding, or the like. Also, cap keel 42 and shafts 46a - 46e can be formed integrally by means of molding, etc.
Here, the formation of cap 41 is first made by coupling cap keel 42 and short shafts 46a - 46e as described above. Then, the coupled cap keel 42 and short shafts 46a - 46e are buried into an open forming die, and by putting silicon rubber, which is also the original material of cap 41, into the die or sandwiching silicon rubber between cap 41 and cap keel 42, these are integrally formed by burning into a one body. Here, the shape of the aforesaid forming die should match the external contour of cap 41 as a matter of course. Now, a reference numeral 60 designates a recovery frame made of a corrosion-inhibiting rigid material such as stainless steel, and the four sides of recovery frame are bent to rise (60a - 60d) in order to enhance the rigidity. To recovery frame 60, short shaft bearings 61a, 61 b, 61c, 61d, and 61 are fixed by screws, etc. (not shown) to receive short shafts 46a - 46e. In this respect, the method for coupling bearings 61 a - 61 e with frame 60 may also be either welding or bonding. Also, as described later, short shaft 46a is fitted into an elongated hole while short shafts 46b - 46d are fitted into the so-called loose holes, and short shaft 46e is fitted to perform positioning. In other words, each of the short shafts 46a - 46e has a same outer diameter, and the inner diameter 61e1, of short shaft bearing 61 e and the outer diameter of short shaft 46e are made to just fit each other. Short shaft bearings 61a - 61 are made of polyacetal resin having excellent slidability against stainless steel short shaft 46e.
As shown in Fig. 9, an elongated hole 61 a, is formed for short shaft bearing 61 a against short shaft bearing 61 e in the longitudinal direction of cap 41. Then, the dimension of elongated hole 61a1 in the transverse direction is formed to fit short shaft 46a. The diameters of holes 61b1, 61c1 and 61d1 opened in short shaft bearings 61 b, 61c, and 61 are respectively formed larger than the outer diameters of short shafts 46b - 46d within a rage of 0.1 mm - 1 mm. Then, at the outside of short shafts 46a - 46e, compression springs 47a - 47e are respectively held by screws from the reverse side of recording frame 60 with short shaft stoppers 56a - 56e sandwiched as shown in Fig. 9.
Compression springs 47a - 47e are pressed between the cap keel and short shaft bearings 61 a - 61 e because the springs are held by screws. The movement of cap 41 at this juncture will be described later.
Further, as shown in Fig. 9, first wiper stay 49 and second wiper stay 51 are held on recovery frame 60 by screws, and the projection 41 a of cap 41, which will be described later, and the wiper leading ends 50a and 52a are arranged to accurately parallel themselves at this juncture. Also the aforesaid projection 41a, wiper leading ends 50a and 52a, and the mounting face of recovery frame 60 for wiper stays 49 and 51, and the imaginary two-dot chain line a in Fig. 9 connecting the center lines of boss sections 59a, and 59b, of front cam gear 59a and rear cam gear 59b are arranged to be in parallel accurately as described later. Also, as shown in Fig. 9, the structure is formed to enable the height of the leading end 52a of second wiper against recovery frame 60 to be higher than that of the leading end 50a of first wiper against recovery frame 60. In order to provide this structure, it is possible to change either the heights of the aforesaid plastic portions made of rubber, etc. of first and second wipers 50 and 52 or the height of rigid portions of first and second wiper stays 49 and 51. Now, a reference numeral 54 designates a recovery frame bearing, and recovery frame shaft 55 shown in Fig. 1C (control cross-sectional view) is allowed to fit the elongated hole 54a of recovery frame bearing 54 in the transverse direction. Here, in this respect, recovery shaft 55 is fixed to main body frame 63, but recovery frame shaft 55 may also be supported rotatably by main body frame 63. Recovery frame shaft bearing 54 is made of polyacetal resin having a good slidableness and is fixedly screwed to recovery frame 60. Recovery frame bearing 54 is fixed against recovery frame 60 in the direction indicated by arrow in Fig. 9 at a position which enables the center of the depth of elongated hole 54a to be in the central part of recovery frame 60. Also, here, the center of hole 61 ci of short shaft bearing 61 c is positioned in the central part of recovery frame 60 in the direction indicated by arrow β as shown in Fig. 9. Further, the center of hole 61b1 of short shaft bearing 61 b and that of hole 61d1 of short shaft bearing 61 are symmetrically positioned in the direction indicated by arrow with short shaft bearing hole 61 ci as the center. Also, the center of elongated hole 61a1 of short shaft bearing 61 a in the direction indicated by arrow and the center of hole 61e1 of short shaft bearing 61 are likewise positioned symmetrically in the direction indicated by arrow with the hole 61 c1 as the center. Now, it is desirable to equalize four distances between the centers of holes, i.e. the distance between the centers of holes 61a1 and 61b1, 61b1, and 61c1, 61c1 and 61d1, and 61d1 and 61e1. Next, a reference numeral 62 designates a recovery frame shaft which is arranged across both of the side plates of main body frame 63. This recovery frame shaft 62 is rotatably supported around a bearing (not shown) provided in main body frame 63. Further, to this recovery frame shaft 62, idler gears 57a and 57b are fixedly mounted respectively at positions inside the main body frame 63 and outside the front cap guide 48a and rear cap guide 48b which will be described later. In view of assembling recovery frame 62 in main body frame 63, parallel pins or spring pins (both not shown) and E ring stopper are used as means to fix idler gears 57a and 57b to recovery frame shaft 62. Further, to recovery frame shaft 62, outer idler gear 58 is fixed with D cut portion formed at an end of recovery frame shaft 62 as its rotation stopper, with main body frame 63 being sandwiched as shown in Fig. 9. Then, to idler gear 57a and 57b, cam gears 59a and 59b are arranged to engage with each other. Cam gears 59a and 59b are rotatably supported on cam gear shafts 70a and 70b fixed to main body frame 63 respectively at positions outside the cap guides 48a and 48b and inside the main body frame 63. Here, the modules and number of teeth of gears 57a, 57b, 59a, and 59b are the same. Furthermore, gear 58 and gears 57a, 57b, 59a, and 59b are of the same number of teeth. Then, gear 58 is connected to stepping motor CM.
As above describes, the number of teeth thus arranged enables the gears engaged with cam gears 59a and 59b to rotate one round exactly the same as the cam gears completing one round, so that the rotational angles and positions of these gears are detected by a microswitch slit type sensor (not shown), etc. to detect the position of the boss section 59a, of cam gear 59a and the boss section 59b1 of cam gear 59b. Therefore, if only a gear, a timing pulley, or the like, which should complete one round in synchronism with the one rotation of cam gears 59a and 59b, is arranged in the driving system for detecting the position of such gear, timing pulley, or the like, it is not necessary to make the number of teeth identical to each of the gears 57a, 57b, 59a and 59b as in the present embodiment. To recovery frame 60, cap guides 48a and 48b are fixedly mounted in addition to these gears. Cap guides 48a and 48b are made of polyacetal resin having a good slidableness. Then, grooves 48a, and 48b1 are formed on cap guides 48a and 48b to fit the boss sections 59a, and 59b1 of cam gears 59a and 59b in the transverse direction as shown in Fig. 10. Here boss section 59a, and boss section 59b1 are arranged at positions just opposite to each other.
Since the structure is of such as described above, recovery frame 60 performs rocking motion in the direction indicated by arrow X in Fig. 10 (central cross-sectional view) with recovery frame shaft 55 as the center when outer idler gear 58 is rotated. Now, since the vicinity of recovery frame 60 is constructed with the parts described as above, recovery frame 60 is positioned by the plane formed by two-dot chain line a and recovery frame shaft 55 as shown in Fig. 9. Here, two-dot chain line a and head shaft 36 are arranged to be accurately in parallel. Although recovery frame 60 is positioned by the plane formed by the aforesaid two-dot chain line a and recovery frame shaft 55, it is not fixed by the aforesaid structural members. Recovery frame 60 is structured to be flexible in the direction indicated by arrow θ and by curbed arrow γ in Fig. 9.
Next, using Fig. 11, the arranging position of first recovery cap guide 48a and second cap guide 48b is the direction indicated by arrow θ in Fig. 9 towards recovery frame 60 will be described in detail. On both first and second cap guides 48a and 48b, U letter type holes 48a, and 48b1 are formed, and the space of U letter hole is precisely defined. The space of the aforesaid U letter holes 48a, and 48b1 is indicated by arrow in Fig. 11. Then, first and second cap guides 48c and 48b are arranged on recovery frame 60 to allow the center of the shorter width of projection 41 a (indicated by arrow in Fig. 11) of cap 41 to be placed in the center of the aforesaid space of U letter holes 48a, and 48b1.
Next, on first head arm 37a and second head arm 37b, circular projections 37a, and 37b1 are formed respectively on front head arm 37a and rear head arm 37b. Then, the arranging positions of the aforesaid circular projection 37a, and 37b1 are defined to allow the ink discharging ports of nozzle section 38a to be placed in the central position of the circular projection. Also, the diameter of the aforesaid circular projections 37a, and 37b1 is formed to fit exactly the spaces of U letter holes on cap guides 48a and 48b.
Now, since the structure is arranged as described above, when recovery frame 60 is raised by the rotation of cam gears 59a and 59b at the time of capping, circular projections 37a, and 37b1 of head arms 37a and 37b are respectively guided to U letter holes 48a, and 48b1 of cap guides 48a and 48b, and nozzle section 38a and projection 41 a of cap 41 are just oppositely placed.
Here, in the present embodiment, recovery frame 60 can be displaced in the direction indicated by arrows θ and γ (in Fig. 9) by the construction as described earier. Therefore, according to the present embodiment, even when there is a slight difference in the positions of the aforesaid U letter holes 48a, and 48b1 and projection 37a, and 37b1 at the time of fitting, recovery frame can fit them reliably while being guided by slant 48c and holes 48a, and 48b1 to displace itself in the horizontal direction if only projections 37a, and 37b1 are in contact with slant 48c of U letter holes 48a1 and 48b1.
Further, the positioning of cap 41 and front head plate 38c, which will be described later, is performed naturally in this course of event. Also, even if recovery frame 60 approaches nozzle orifice face 38b with some inclination, projection 41 a and nozzle section 38a can approach each other with the face to face positional relationship.
Fig. 10 illustrates the state immediately after head 38 and cap 41 are in contact with each other. Fig. 11 illustrates the state when head 38 and cap 41 are parted. Fig. 12 illustrates the state when cap 41 is moved forwards head 38. Fig. 13 illustrates the state where projection 41 a closes nozzle 38a by pressure, and spring 47 is resiliently deformed. Fig. 14 illustrates the state where cap 41 is parted from head 38, and Fig. 15 illustrates the standby state. In each of the figures, A is a side view observed from the location of side plate; B is a cross-sectional view in the transverse direction; and C is a cross-sectional view in the longitudinal direction. In Fig. 11, however, A is also a side view but B is a cross-sectional view in the longitudinal direction.
At first, Figs. 10A through 10C illustrate the state representing the moment cap 41 has come into contact with front head plate 38c. Cap 41 has not been deformed as yet. In conjunction with Fig. 10B, the cross-sectional shape of cap 41 is described in detail. The side portions of cap 41 are formed with inclination so as to widen the distance between them as the cap is raised upwards as shown in Fig. 10B. The inclined side portions are connected to the curbed portions indicated by mark a in Fig. 10B, and the thickness of the portions a are made thinner than the other portions as illustrated in Fig. 10B. Although, in the present embodiment, the portions a are formed with a smooth curvature, these portions may also be formed in an abrupt edge. In the case of an abrupt edge in which these should be formed, the thickness of such edge portions could be made thinner. Likewise, in Fig. 10C, the cross-sectional shape of cap 41 in the transverse direction is formed to open itself towards the outside as it is raised upwards as in Fig. 10C.
The cross-sectional shape of cap 41 in the transverse direction is formed in such a manner that the thickness of cap 41 contacting with front head plate 38c is made thicker than that of the cross-sectional shape of cap 41 in the longitudinal direction shown in Fig. 10B also contacting the aforesaid front head plate 38c. This is due to the fact that although the positioning of cap 41 against head 38 in the transverse direction is accurately performed, the positioning in the longitudinal direction is not performed accurately. Therefore, such construction as is the present embodiment may not be needed if only the positioning of cap 41 against head 38 is accurately performed in the longitudinal direction. Now, reverting to Fig. 10C, the side portions of cap 41 are connected to curbed portions b which change its shape smoothly as in Fig. 10B, and the thickness of portions b is made thicker. In the present embodiment, the shape of cap 41 in Figs. 10B and 10C is such that the thickness thereof becomes increasingly thinner smoothly towards as illustrated in these two figures. Now, reverting to Fig. 10B, in the closed space in cap 41, projection 41 a integrally formed with cap 41 is provided. The arranging position of projection 41 a is defined so as to allow the top of R shaped portion 41 c of projection 41 a to be located at a position against nozzle section 38a. The length of projection 41 a in the longitudinal direction at both ends is made longer than the entire length in which nozzle section 38a is arranged. Next, through hole 41 b is provided on cap 41. The through hole 41 b in cap 41 is provided with through hole 41 provided on cap keel 42. Then, the aforesaid through hole 41 b, valve 43 is fitted. The aforesaid valve 43 being formed with plastic material, it can produce a state which is closed from the atmosphere without any pressure exerted on valve 43. Here, the reason why valve 43 can properly function as a valve is that while cap keel 42 is formed with rigid material as described earlier, the contact face between valve 43 and cap keel 42 is formed excellent precision.
In this respect, when cam gears 59a and 59b are further rotated in the direction indicated by arrow d, cap 41 further approaches head 38 and the projection 41 a of cap 41 contacts nozzle 38a. Here, there is almost no deformation of cap 41 with the exception of projection 41a. Also, when cam gears 59a and 59b are still further rotated in the direction indicated by arrow d, compression spring 47a begins to deform, and the reaction generated by the aforesaid compression spring 47a causes projection 41 a of cap 41 to press nozzle section 38a. In this respect, only compression spring 47a is illustrated in Fig. 10 through Fig. 15, but the other compression springs 47b, 47c, 47d, and 47e function in the same way as compression spring 47a. Here, the time needed for the aforesaid projection 41 a to press nozzle 38a is approximately several seconds which are required for liquid ink to circulate in head 38. At this juncture, a pump is actuated to circulate liquid ink.
In the above-mentioned embodiment the cap 41 and the projection 41 a are integrally formed of an elastic material such as rubber. However, the cap 41 may be a member separate from the projection 41 a and the whole body of the cap 41 does not have elasticity. At least the head discharge port surface 38c and the contact section may be elastic and in this case a remaining upper part thereof may be of steel.
Now, Fig. 13 illustrates the state where compression spring 47a is deformed as the above describes, and boss sections 59a, and 59b, of cam gears 59a and 59b are positioned at the top. In Fig. 13, there is almost no volume change in the closed space formed by the cap 41, and valve 43 only shows the state to close air. Therefore, the pressure in the closed space is equal to the atmospheric pressure. Hereinafter, the state of each part, when cam gears 59a and 59b are rotated from the state shown in Fig. 13 in the direction indicated by arrow e, will be described. Now, the rotational direction of cam gears 59a and 59b means the required movement of boss sections 50a, and 59b, from the top to the bottom or from the bottom to the top as shown in Fig. 13, and even if, for example, cam gears 59a and 59b are rotated in the direction reverse to that indicated by arrow e in Fig. 13, the movements described below should take place in the same manner. In Fig. 14, the volume in the closed space in cap 41 is again increased and the pressure in the closed space becomes negative against the atmosphere, and valve 43 is closed as shown in Fig. 14. Therefore, in order to supplement the reduced volume in the closed space in cap 41, ink is discharged from nozzle section 38a of recording head 38. Ink remaining in nozzle section 38a is refleshed.
With a structure such as this, even if there is a slight difference in the positions of the aforesaid V letter holes 48a2 and 48b2 and the aforesaid square projections 37a3 and 37b3, recovery frame 60 enables the holes 48a2 and projection 37a3 and the hole 48b2 and projection 37b3 to be mated reliably because the frame can displace itself in the directions indicated by 0 and y in Fig. 9.
With a structure such as this, even if there is a slight difference in the positions of the aforesaid circular projections 48a3 and 48b3 and the aforesaid U letter holes 37a5 and 37bs, recovery frame 60 enables the projection 48a3 and hole 37a5 and the projection 48b3 and hole 37b5 to be mated reliably because the frame can displace itself in the directions indicated by arrows 0 and y in Fig. 9.
Fig. 16 is a view illustrating the concept of an embodiment according to the present invention. In Fig. 16, an ink cartridge cam prises recording head 38, ink pump 76, ink tank 86, wast ink absorber 96, and air duct 87 which is called breezer.
The initial ink supply to recording head 38 is carried out in a manner given below. In other words, ink pump 76 is actuated in a state where cap 41 is closely contacted with the recording head (a state shown in Fig. 13 where projection 41 a in cap 41 is in contact with nozzle section 38a of recording head 38) to circulate ink from ink cartridge 86 in the direction indicated by arrow E, so that the inside of the tubes including the inside of the recording head is filled with ink. At this time, some ink is flown out to cap 41, but it is returned to ink cartridge 86 through waste ink tube 45 and collected to built-in ink absorber 96.
A reference numeral 92 designates a no-ink detector for detecting no-ink condition in tank 94. The detection is carried out in a manner given below. In other words, since float chamber 90 is open to the atmosphere through breezer 87 which is commonly provided for ink tank 94, the liquid level therein and float 89 which floats thereon indicate the same water level 91 a as liquid ink level 91 in ink tank 94. Therefore, at an appropriate location in the lower part of float chamber 90, sensor 88 is arranged for detecting a light interruption. Thus, when liquid level 91 is lowered, i.e., float 89 is lowered following the lowering of water level 91 a in the area for detection, the emitting light from the sensor 88 is interrupted, thereby detecting the no-ink condition.
Next, the recovery operation is described. The recovery operation is an action to remove bubbles and cloggings which bender the normal discharging, and is performed in accordance with the recovery sequence, which will be described later, controlled by the recovery system. The recovery operation, however, is exactly the same as the initial ink supply operation. In other words, ink pump 76 is actuated while cap 41 is in contact with recording head 38 (the current state is illustrated in Fig. 13) to circulate ink in the direction indicated by arrow A, so that bubbles are collected into the ink tank to release them to the outside through the breezer. Also, the contacting condition between projection in cap 41 and nozzle 38a is released to drive the pump for the removal of any clogging in the nozzle. At this time, pressurized ink is flown into float chamber 90. Then, float 89 is raised to closely contact with upper face of float chamber 90 to cover the passage to breezer 87. Therefor, no ink is flown into breezer 87.
Fig. 17 is a perspective view showing the construction of supply and recovery systems, in which the structure of the present embodiment is actually employed. In Fig. 17, a reference numeral 73 designates the base of this unit which also functions as a base for installing ink cartridge 86, which will be described later. Also, a reference numeral 74 designates a member called joint plate which is formed by fixing each of various passage couplers. To this joint plate 74, there are coupled cartridge guide 78 for positioning ink cartridge 86, cartridge joints 79a, 79b, and 79c for connecting tubes to release air, waste ink joint 81 for guiding waste ink produced at the time of recording to waste ink absorber 96 built in ink cartridge 86 through waste ink tank, air joint 80 for connecting the breezer for releasing air with air tube 83, first and second supply tube joints 84 and 85 for connecting first and second ink supply tubes 71 and 72 with ink pump 76 which is driven by pump motor 77. Thus, ink joint 79 connected to ink tank 94 accommodated in ink cartridge 79a provides three functional sections intensively, first ink supply section 79a, second ink supply section 79b, and air passage connecting section 79c, and with its structure, enables first ink supply inlet 95a, second ink supply inlet 75b and air inlet 95c to be coupled altogether, which are operationally related to the function of ink tank 94.
For this purpose, the air passage section leading to the ink tank is formed by joints, thereby making it possible to construct the ink tank with hard resin material, to reserve a large quantity of ink without employing ink bags.
Especially, it is necessary to provide flexibility not only vertically and horizontally but rotatably when a plurality of joints should be connected. In the present embodiment, a slight rotatability is maintained to obtain a rotatable flexibility against the central axis of joint section 95 by supporting ink tank 94 with spaces 97 (in this embodiment, for example about 1.0 mm) and spaces 97a (for example, about 1.0 - 2.0 mm) provided for both ends of ink tank 94 and by waste ink absorber 96 which is soft like felt. A projection 93d supports a front bottom of the ink tank 94. Hence it is possible to make connections reliably without any deviations in positioning. In this embodiment the joints 95a, 95b and 95c of the ink tank are provided about 0.5 mm lower with respect to the body joints 79a, 79b and 79c so that the ink tank 94 is connected to the body joints in a state which it floats about 0.5 mm to the body joints. Furthermore, in order to prevent any abnormal sound generated by the movement of ink tank 94 by vibrating impact, etc. or breakage of housing as well as to effectively utilize space, the central part of waste ink absorber 96 is removed as shown in Fig. 18 to allow the lowest bottom ink tank 94 to be fitted into the removed part, so that the ink tank is held by the remaining portion of circumference. With this structure, impact can be absorbed by the softness of waste ink absorber 96 and the required flexibility is maintained. In this way, the ink tank is protected from the external impact and the clattering of ink tank is also prevented because in this structure the waste ink absorber is fitted at the lowest bottom of the ink tank and at the same time, the ink tank is held by soft material such as felt of the circumferential portion of the waste ink absorber.
Next the recovery sequence will be described. The recovery operation is needed to maintain a normal recording. With this operation which is performed by the linkage of recovery system and ink supply system, bubbles and cloggings in the flow passage are removed. Fig. 22 is a flowchart showing this operation. Figs. 23A through 23D are schematic views showing the system in operation. In Figs. 23A through 23D, for the purpose of simplifying description, a unit comprising recording head 38, head arms, etc. is defined as head unit 65, another unit comprising cap 41, wipers 50 and 52, recovery frame 60, etc. is defined as cap unit 65. Head unit 65 is rotatable with head shaft 36 as its rotating center while cap unit 64 is rotatable with recovery frame shaft 55 as its rotating center. Hereinafter, the sequence of recovery operation will be described.
In the normal standby state, the relationship between recording head 38 and cap 41 is, as has been already described, that the closed state is maintained as shown in Fig. 15 by slightly bending the periphery of the cap. The recovery operation begins as shown in Fig. 12 with pressing projection 41 a in cap 41 against nozzle 38a arranged on the top of recording head by rotating cam gears 59a and 59b (the cap unit position at this juncture is referred to as press position) (S22-1). Next, in this state, ink pump 76 is actuated to circulate ink in the supply passage (S22-2) and remove bubbles in the tube. Projection 41 a is pressed against nozzle 38a in order to prevent ink from being flown out from the nozzle because otherwise a part of ink is not circulated by the pressure generated by the ink pump and flown out of the nozzle as useless waste ink.
Particularly, at the time of cleaning, it is important for the two blades to contact with the discharging port face of recording head each individually to perform cleanings, so that the effect of double- wiping should be obtained. With a sequential arrangement of two blades such as this, the cleaning time can be shortened as compared with the case where a cleaning action is taken twice with one blade. Also, in the present embodiment, the size of blade 50 which contacts the recording head first differs from the size of blade 52 which contacts it subsequently. The recording head rotates with head shaft 36 as its rotating center, and in order to place the leading end of the blade to be in contact with the discharging port face within the path of the recording head to move, it is necessary to define the length of each blade accordingly. Therefore, it is also possible to perform the required cleaning by driving the cap unit following the rotational movement of the recording head while making the length of each blades 50 and 52 the same or making the relational length of each of them reversed.
Also, by making the length of each of plural blades contacting the rotating head 38 different, it is possible to vary the length I of the leading end of the blade contacting the discharging port face 38c of the head and/or the contacting degree 80 of each blade (Fig. 23E). Hence, it is possible to vary the force and area of each blade with which to contact discharging port face 38c to control possible splashing of adhered ink and dust on discharging port face 38c to the surrounding area at the time of cleaning off. Also, by making the contacting amount and/or contacting angle 80 of each blade against discharging port face 38c greater sequentially following the order in which each of the blades are in contact with discharging port face 38c of the head, it becomes possible to allow the first blades to contact discharging port face 38c lightly when there are more ink or dusts adhered thereto, which should be cleaned off and the later blades to contact it sufficiently to clean off the remaining ink and dusts. Consequently, while controlling the possible splashing of ink and dusts adhered to discharging port face 38c to the surrounding area, it is possible to remove them completely.
Furthermore, when the first blade wipes discharging port face 38c, the rest of blades function as protective wall (Fig. 23C) to prevent the ink and dusts removed by the first blade from being splashed to surrounding area of the recovery system and eliminate the causes to stain the recording sheet or to electrically short circuit electronic circuit board.
Next, the recovery operation which is executed by circulating ink will be described further in detail. In the present embodiment, as shown in Fig. 16, bubble sensor 103 (for example, a transmitting sensor, etc.) is provided to enable detecting bubbles in ink supply tubes. Accordingly, it is possible to perform two different types of recovery operations, i.e., an automatic recovery to be carried out periodically each at a predetermined time, and an occasional recovery to be performed when bubble sensor 103 detects any incidental bubble or bubbles. The occasional recovery becomes possible with the installation of bubble sensor 103, and with this, the incidental non-discharging hitherto experienced can be reduced, thereby making it possible to improve the reliability of the apparatus. Particularly, in consideration of the safety with which all bubbles are removed irrespective of the presence of bubbles, the amount and location thereof, a considerably excessive circulation time and number has been given to perform a sufficient removal of bubbles. In the present embodiment, however, bubble sensors 103a and 103b are provided at either sides of up and down streams of ink flow towards the recording head at the time of circulation. Therefore, if no bubbles are detected by both of the bubble sensors, the recovery action is immediately suspended. Particularly when bubble sensor 103b arranged at the down stream of ink flow at the time of circulation should detect a signal indicating that bubbles have been removed (no bubble presence), the ink pump is stopped after a while (a period required for the detected bubble exhausted to the tank from the current position of the sensor). Consequently, there is no need for providing any excessive circulation time as has been required conventionally, resulting in the termination of the recovery sequence in a shorter period of time. Also, there is an advantage that the reliability of bubble removal improves because the recovery action is terminated after no bubble presence has been detected. In this way, the amount of ink consumed for recovery becomes small, which leads to the prevention of no ink condition at the time of receiving facsimile or of no reception state during the recovery operation.
While the apparatus is in the standby state, CPU examines timer ti in the CPU as well as the bubble sensor. If timer ti indicates a predetermined time T1 (24 hours, for example), the recovery operation is started (S27-2).
Also, even when the timing is not t1 = T1, the recovery operation is started if bubble sensor 111 is on (the presence of bubble indicated) (S27-3).
For the typical structure and principle of an invention of the kind, it is preferable to employ the fundamental principle disclosed in the specifications of, for example, U.S. Patents 4723129 and 4740796. This method disclosed in applicable to the so-called on-demand type as well as to the continuous type. Particularly in the case of the on-demand type, by applying at least one driving signal, corresponding to recording information and providing a rapid temperature rise which exceeds nuclear boiling, to an electrothermal converter arranged for sheet or liquid passage holding liquid (ink), heat energy is generated in the electrothermal converter, and film boiling is accordingly generated on the thermal active face of recording head. As a result, bubbles are formed in the liquid (ink) one to one by this driving signal effectively. By the growth and contraction of this bubble, the liquid (ink) is discharged through the discharging port to form at least one droplet. If this driving signal is made to be a pulse type, the growth and contraction of bubble can be effectuated instantaneously and appropriately, and it should be more preferable to employ such system because with it, a discharging of liquid (ink) having an excellent responsibility can be attained. For a driving signal of the pulse type, those disclosed in the specifications of, for example, U.S. Patents 4463359 and 4345262 should be suitable. In this respect, if conditions disclosed in the specification of U.S. Patent 4313124 concerning an invention of the ratio of temperature rise on the aforesaid thermal active face are employed, a further excellent recording can be performed.
For the structure of recording head, those structures, in which a thermal active unit is arranged in a bending region, disclosed in the specifications of U.S. Patents 4558333 and 4459600 are included in the present invention in addition to a combination structure (linear liquid flow passage or right angled liquid flow passage) of discharging ports, liquid passage, and electrothermal converter such as disclosed in each of the above mentioned specifications. Besides, the present invention is still effective for the structures based on the structure disclosed in Japanese Laid-Open Patent Application No. 59-123670 in which common slits against a plurality of electrothermal converters function as discharging ports of the electrothermal converter, and the structure disclosed in Japanese Laid-Open Patent Application No. 59-138461 in which an opening for absorbing the pressure wave of heat energy is used for the discharging port.
In the embodiment set forth above according to the present invention, the description has been made of the case where liquid ink is used, but the present invention is also applicable to solid ink at room temperature as well as to ink becoming soft at room temperature. In the above-mentioned ink jet apparatus, it is usual to perform temperature control to make viscosity of ink to be in the range of stable discharging by adjusting the temperature of ink itself more to be than 30 ° C but less than 70 °C. Therefore, if only ink becomes fluid at the time of applying recording signals in use, those kinds of ink are also usable. Furthermore, the present invention is applicable to the use of ink having the property that the ink becomes fluid only by heat energy such as the one which can be discharged as liquid ink when it becomes fluid by the application of heat energy in response to recording signals or ink already becoming solidified at the time of reaching recording medium by utilizing positively the temperature rise caused by heat energy as energy to change the state of ink from solid to fluid for prevention or by using ink which is solidified when it is left for the purpose of preventing evaporation. In such case, ink can be held as liquid or solid state in a concave of porous sheet or through holes as described in Japanese Laid-Open Patent Application No. 54-56847 or Japanese Laid-Open Patent Application No. 60-71260, and is placed against the electrothermal converter in such mode. In the present invention, the performance of the above-mentioned film boiling method is most effective when each of the above-mentioned kinds of ink is employed.
In the above-mentioned embodiment, the ink container relating to three flow paths was explained as a sample, but it is possible to remove any extra backlash, by limiting the degree of freedom in a certain direction depending on the construction or number of the flow paths.
In the above-mentioned embodiment, specially, the engagement of the container with the device is made only with the cylindrical portion at the periphery of the joint portions, but if such cylindrical portion for the engagement is changed in number or shape (for example to a polygonal or elliptic cylinder shape), then it is possible to reduce an extra degree of freedom after the mounting, and improve the stability of the seal for the connecting portion. The above-mentioned embodiment is so constructed that three connections relating to the communicating port to the air, the supplying side to the recording head at the time of the ink circulation and the returning side, respectively are made, but in order to achieve more effectively the removal of the babbles due to the ink circulation by decreasing the flow path resistance, correspondingly to the structure of the recording head, more supplying tubes may be used. At that time, it is possible to divide the supplying side and the returning side to plural ones, respectively, by applying thereto the above-mentioned embodiment.
Further, in the above-mentioned embodiment, the structure in which the waste ink absorbing body is positioned on the bottom of the ink tank was explained. However, it is also possible to attain a more certain shock absorbing effect by adding it to the sides and top of the ink tank as well as the bottom. Also, it is possible to use a waste ink absorbing body with appropriate elasticity to prevent waste ink which has been absorbed from being squeezed out by the weight of the ink tank.
Further, in the above-mentioned embodiment, the soft member positioned at the bottom of the ink tank are used to have the waste ink and mechanical shock absorbing functions, but it is possible to achieve the similar effect to the above even when an additional member with a superior shock absorbing capability, etc. is provided separately to said soft member, or the frame itself is formed with a soft material.
Furthermore, in the above-mentioned embodiment, the recording head having at its both ends the supplying tubes and carrying out the recovery operation by the circulation is used, but this invention may be applied to a recording head having one supplying tube and of which recovery operation is carried out by suction from the front face of the nozzle. Also, it is possible to decrease the cost by forming both of the babble sensor and the recording head in a body.
As explained above, in accordance with the embodiments according to the present invention, the ink jet recording apparatus is provided in which easy registration in position of the joint portion of the ink supplying side to the joint portion of the cartridge side is accomplished so that the ink cartridge is surely mounted.
Also, since the joint portion of the ink supplying side is stationary, the complicated distribution of the ink supplying path from this joint portion to the recording head can be avoided and the sealing security after the connection can be improved. Therefore, the ink jet recording apparatus is provided which has the reliable joint portions from which any ink leakage due to vibration or shock does not occurred. Further, in accordance with the embodiments according to the present invention, three connections for the paths for supplying ink at the time of the circulation, the returning path and the communicating port to the air are used detachably between the ink tank side and the joint sides, and thus, it is possible to provide the ink supplying device which is voluminous, and strong in vibration and shock and which has no use for the sub-tank. Accordingly, it is possible to provide the ink jet recording apparatus having the ink supplying device which is low-priced, compact and moreover highly reliable. Also, in the above-mentioned embodiments, by not only holding the ink tank at its periphery with a soft member and but also using such soft member as the waste ink absorbing body, it is possible to, achieve an ink cartridge which is strong in vibration and shock, which can use effectively the space and which is compact and low-priced. In this connection, it is also possible to provide the ink jet recording apparatus which is miniaturized and has its decreased running cost and improved reliability. Further, in accordance with the above-mentioned embodiments, it is possible to provide an ink jet recording apparatus in which by controlling the operation of the ink pump using the means for sensing a babble in the ink supplying paths, the recovery operation can be reduced in frequency and time to minimum necessary values, the volume of waste ink can be decreased and the number of the recording papers which are recorded with a predetermined amount of ink can be increased, and, thus, its running cost can be reduced. Also, in a case where the above-mentioned embodiments are applied to a facsimile machine, since the time necessary to carry out the recovery process is shortened, a long recording enabling time can be achieved, and a probability of disabling facsimile signal reception because the facsimile machine is subject to the recovery process can be made to be small. An ink cartridge adapted to be loaded detachably to an ink jet recording apparatus for preforming a recording on a recording medium by discharging ink comprises an ink tank for accommodating ink therein, leading-out means for leading out ink within said ink tank to the outside, said leading-out means being provided on said ink tank, and a frame for supporting displaceably said ink tank on which said leading-out means is provided. Also, an ink jet recording apparatus for preforming a recording on a recording medium comprises a recording head for discharging ink from a discharge port to carry out the recording on the recording medium, a lording part for loading therein an ink cartridge, said loading part having an ink tank for accommodating ink, therein, leading-out means for leading out ink within said ink tank to the outside, said leading-out means being provided on said ink tank and a frame for supporting displaceably said ink tank on which said leading-out means is provided, and ink supplying means for supplying ink to said recording head by coupling to the lead-out means of said ink cartridge which is loaded in said loading part.
1. An ink jet recording apparatus, wherein at the time of recording ink is supplied from first and second ink supplying paths (71, 72) to an ink jet recording head (38), and at the time of initial filling or recovery ink is circulated through the first ink supplying path (71), the recording head and the second ink supplying path, in turn, by a pump driving (76), characterized in that first and second bubble sensing means (103a, 103b) are provided in respective portions of said first and second ink supplying paths, respectively, to sense a bubble in the respective supplying paths, and when the bubble is sensed by said first or second bubble sensing means, said pump (76) is actuated so that the recovery operation is carried out, said pump being driven until the second bubble sensing means (103b) positioned downstream in the ink circulating direction at the time of said recovery terminates the sensing of the presence of the bubble.
2. An ink jet recording apparatus according to claim 1, characterized in that said first and second bubble sensing means (103a, 103b) are of a type optically sensing the bubble in the respective ink supplying path (71, 72).
3. An ink jet recording apparatus according to claim 1 or 2, characterized in that said ink jet recording head is of a full-line type having discharging ports formed across the whole width of the recording area of the recording medium.
4. An ink jet recording apparatus according to one of claims 1 to 3, characterized in that said recording head is of a type of discharging ink by the use of heat energy, and that an electrothermal converter for generating said heat energy is provided.
5. An ink jet recording apparatus according to claims 1 to 4, characterized in that said ink jet recording apparatus is a facsimile machine having a manuscript reading part.
EP19950110640 1990-02-13 1991-02-13 Ink supplying device and ink jet recording apparatus using the same Expired - Lifetime EP0684139B1 (en)
JP31704/90 1990-02-13
JP3173190A JPH03234658A (en) 1990-02-13 1990-02-13 Ink jet recording device
JP31731/90 1990-02-13
JP3171590A JPH03234655A (en) 1990-02-13 1990-02-13 Ink feeding device and ink jet recording device loaded with same ink feeding device
JP31715/90 1990-02-13
JP3173590A JPH03234665A (en) 1990-02-13 1990-02-13 Ink cartridge and ink jet recording device loaded by same cartridge
JP31735/90 1990-02-13
JP3170490A JPH03234653A (en) 1990-02-13 1990-02-13 Ink jet recorder
EP19910102045 EP0442485B1 (en) 1990-02-13 1991-02-13 Ink supplying device and ink jet recording apparatus using the same
EP91102045.1 Division 1991-02-13
EP19910102045 Division EP0442485B1 (en) 1990-02-13 1991-02-13 Ink supplying device and ink jet recording apparatus using the same
EP0684139A1 true true EP0684139A1 (en) 1995-11-29
EP0684139B1 EP0684139B1 (en) 1998-10-28
ID=27520185
EP19910102045 Expired - Lifetime EP0442485B1 (en) 1990-02-13 1991-02-13 Ink supplying device and ink jet recording apparatus using the same
EP19950110640 Expired - Lifetime EP0684139B1 (en) 1990-02-13 1991-02-13 Ink supplying device and ink jet recording apparatus using the same
EP (2) EP0442485B1 (en)
DE (4) DE69130429T2 (en)
EP0778141A1 (en) * 1995-12-04 1997-06-11 Hewlett-Packard Company Out-of-ink sensing system for an ink-jet printer
EP0860283A1 (en) * 1997-02-19 1998-08-26 Canon Kabushiki Kaisha Ink jet recording apparatus, and method for recovering an ink jet recording head
EP0997286A1 (en) * 1996-12-24 2000-05-03 Seiko Epson Corporation Ink-jet recording apparatus
JPS5613456A (en) 1979-07-16 1981-02-09 Mitsubishi Alum Co Ltd Aluminum alloy for brazing filler metal of brazing sheet
JPS5641148A (en) 1979-09-12 1981-04-17 Canon Kk Vessel for recording liquid
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PATENT ABSTRACTS OF JAPAN vol. 3, no. 159 (E - 162) 27 December 1979 (1979-12-27) *
US6305778B1 (en) 1996-12-24 2001-10-23 Seiko Epson Corporation Ink-jet recording apparatus
DE69122523D1 (en) 1996-11-14 grant
EP0442485B1 (en) 1996-10-09 grant
DE69122523T2 (en) 1997-02-27 grant
EP0684139B1 (en) 1998-10-28 grant
DE69130429D1 (en) 1998-12-03 grant
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