Patent Application
20080062222
Embodiments of a liquid container, a recording device and a liquid collection system according to the present invention will hereinafter be described with reference to the drawings.
An ink tank of the present embodiment is a so-called main ink tank. In the tank, ink as a liquid to be supplied to a sub ink tank is stored. The sub ink tank is to be moved integrally with a recording head which discharges a liquid in the recording device. The ink is supplied from the ink tank to the recording head via this sub ink tank.
The first storage section 11 has a plurality of storage chambers in which a plurality of colors of ink to be supplied to the recording head are stored independently of one another. The first storage section 11 is provided with a plurality of joint portions 18 for ink supply which are connected to an ink supply system on the side of the ink jet recording device. From the joint portions, the plurality of colors of ink are supplied to the recording head. As one example, the ink tank 5 of the present embodiment includes the joint portions 18 for supplying the ink of four colors of yellow (Y), magenta (M), cyan (C) and black (K).
Moreover, in the ink jet recording head on which the ink tank 5 is mounted, after the ink jet recording head is left to stand for a short time, the ink is preliminarily discharged in order to prevent an initial discharge defect. In this ink jet recording device, when the ink jet recording head is left to stand for a long time, the ink is periodically sucked. This is performed in order to prevent that the ink jet recording head does not discharge any ink owing to bubbles mixed in the ink jet recording head which has been left to stand for the long time.
To perform this operation, the second storage section 12 includes a waste ink absorption member 16 in which the waste ink generated by the preliminary discharge and the periodic ink suction is collected from the recording head and stored. The waste ink does not contribute to image formation. The second storage section 12 also includes a joint portion 19 for ink collection into which the waste ink collected from the ink jet recording head is introduced.
Moreover, the information holding portion 13 of the ink tank 5 includes an information recording medium 17 in which information can be recorded. In this information recording medium 17, information on a total amount of waste ink absorption is recorded as a total amount of the waste ink absorbed by the waste ink absorption member 16. As this total waste ink absorption, an initial value of “0” is recorded, when the ink tank is a new tank. In the information recording medium 17, a waste ink collection time (a collection period) of one past time close to the present time, that is, the previous time is recorded. Any waste ink collection time is not recorded, when the ink tank 5 is the new tank.
Furthermore, in the information recording medium 17, information on the shortest time period from a time when the collection of the waste ink into the ink tank 5 is completed until the next waste ink collection can be performed is stored.
The next waste ink collection cannot be performed until the waste ink fed to the second storage section 12 by the previous waste ink collection is sufficiently absorbed by the waste ink absorption member 16. If the next waste ink collection is performed with the non-absorbed waste ink left in the waste ink absorption member 16, the waste ink cannot be absorbed by the waste ink absorption member 16, and leaks from the second storage section 12.
The shortest time period X of the waste ink absorption is a waiting time required until the amount of the waste ink which is not absorbed by the waste ink absorption member 16 from the previous waste ink collection decreases to a predetermined amount or less and newly collected waste ink can sufficiently be absorbed by the waste ink absorption member 16.
It is to be noted that the shortest time period X of the waste ink absorption is a value which changes with the total amount of the waste ink absorption. When the total amount of the waste ink absorption increases, the shortest time period X of the waste ink absorption gradually increases.
That is, information to be recorded in the information recording medium 17 includes the total amount of the waste ink absorption by the waste ink absorption member 16 including an initial value of zero, the shortest time period X of the waste ink absorption having a value which continuously changes with the total amount of the waste ink absorption, and the previous collection time of the waste ink.
Table 1 shows one example of the shortest time period X of the waste ink absorption. The shortest time period X of the waste ink absorption differs with a type of the ink. When the ink is permeable ink (hereinafter referred to as the first ink) such as color ink including a surface active agent, a value of the period is comparatively small. When the ink is impermeable ink (hereinafter referred to as the second ink) such as black pigment ink, the value of the period comparatively increases. Table 1 shows first ink 3A and second ink 3B as typified ink.
Moreover, in actual, the waiting time from the previous waste ink absorption until the next waste ink absorption can be performed also changes with the amount of the previously collected waste ink. The amount of the waste ink to be collected differs between the preliminary discharge and restorative suction. Each of the preliminary discharge and the restorative suction has a plurality of modes, and the amount of the waste ink to be collected differs with the mode. Therefore, as shown in Table 1, the shortest time period X of the absorption extracted from the table for use in a case where a standard amount of the waste ink is collected is sometimes corrected in accordance with an actual amount of the waste ink absorption.
Furthermore, as the total amount of the waste ink absorption by the waste ink absorption member 16 increases, an ink absorption capability of the waste ink absorption member 16 gradually deteriorates. Therefore, the amount of the waste ink absorption per unit time gradually decreases. Table 1 shows one example in which the shortest time period X of the waste ink absorption changes with the total amount of the waste ink absorption, in a case where it is assumed that the waste ink can sufficiently be absorbed by the waste ink absorption member 16 within this period and any floating ink does not exist. It is to be noted that this value of the shortest time period X of the waste ink absorption is determined by the type of the ink as described above. In addition, the value is determined by a structure of the ink tank, and a material and a shape of the waste ink absorption member 16.
As one example, the inside of the sub ink tank 7 is divided into ink chambers of four colors of yellow (Y), magenta (M), cyan (C) and black (K). The ink jet recording head 6 is constituted integrally with the sub ink tank 7. When the recording material is scanned and the ink jet recording head 6 discharges a plurality of colors of ink droplets, an image is formed on the recording material.
The ink tank 5 of the present embodiment is connected to the sub ink tank 7 via ink supply tubes 21, and the ink is supplied from the ink tank 5 to the sub ink tank 7 via the ink supply tubes 21. Instead of the ink supply tubes 21, a joint mechanism (not shown) via which the sub ink tank 7 is disconnectably connected to the ink tank 5 may be provided, and the present invention is applicable to such a constitution.
The ink jet recording head 6 causes an initial discharge defect even after the head is left to stand for a comparatively short period. Therefore, when the head is left to stand even for a short period, the preliminary discharge is performed in order to prevent the initial discharge defect before the image is recorded in the recording material. Moreover, bubbles are sometimes mixed in the ink jet recording head 6 after the head is left to stand for a long period. In this case, an operation of sucking the bubbles from the ink jet recording head 6 is performed. Furthermore, the ink is sucked. This ink sucking operation is usually performed periodically after the ink jet recording head 6 is left to stand for the long period.
As shown in
Moreover, in the ink sucking operation of removing the bubbles after the ink jet recording head 6 is left to stand for the long period as described above, the ink jet recording head 6 is moved to and fixed at such a position as to face the suction cap 23. Subsequently, after the suction cap 23 is brought into close contact with the ink jet recording head 6 on the discharge port side, the suction pump 24 is operated, thereby performing the ink sucking operation. The waste ink generated by this restorative suction operation is circulated through the ink tank 5 via the waste ink discharge tube 22, absorbed by the waste ink absorption member 16 and stored in the ink tank 5. The amount of the waste ink to be generated by the restorative suction operation sometimes differs with the mode of the restorative suction.
An ink jet recording device main body 300 includes a CPU 310, an ROM 311 in which a control program and data are stored and an RAM 312 in which data of control, image processing and the like is temporarily stored and from which the data is read.
When the ink tank 5 is mounted on the recording device 300, the information holding portion 13 is connected to the CPU 310 via an electric contact, so that the information can be recorded in the information recording medium 17 of the information holding portion 13 and can be read from the information recording medium 17.
Alternatively, the information holding portion 13 and the CPU 310 may exchange the information by radio.
Moreover, when the waste ink is continuously discharged to the waste ink absorption member 16, the shortest time period X of the waste ink absorption corresponding to the total amount of the waste ink absorption is read from the information recording medium 17 of the ink tank 5 by the control section of the ink jet recording device. This shortest time period X of the waste ink absorption is the shortest time period when the waste ink can sufficiently be absorbed by the waste ink absorption member 16 and any floating ink does not exist in the second storage section 12 of the ink tank 5. The previous collection time of the waste ink is read from the information recording medium 17 by the control section of the ink jet recording device. However, the time is not read, when the ink tank 5 is the new tank.
Subsequently, when the suction pump 24 needs to be operated, as shown in step 103, a command for operating the suction pump 24 is generated in the ink jet recording device. When the command for operating the suction pump 24 is generated, first as shown in step 104, a lapse time Y from the previous collection time of the waste ink up to now is calculated. Subsequently, as shown in step 105, this lapse time Y from the previous collection time of the waste ink is compared with a value of the shortest time period X of the waste ink absorption.
When Y≧X, a sufficient time elapses from the previous time when the waste ink is discharged into the ink tank 5 and absorbed by the waste ink absorption member 16. Therefore, in a case where the waste ink is absorbed by the waste ink absorption member 16, any floating ink does not exist in the ink tank 5 and the waste ink is newly discharged into the tank, it is judged that the waste ink can be absorbed by the waste ink absorption member 16. The step advances to step 106 to operate the suction pump 24. In consequence, the waste ink is discharged into the second storage section 12 of the ink tank 5, and absorbed by the waste ink absorption member 16.
When Y<X, as shown in step 107, the suction pump is stopped for a predetermined time period, and waits until Y≧X is satisfied. Subsequently, when Y≧X is satisfied, the suction pump 24 operates. During this stop, a sufficient time elapses from the previous time when the waste ink is discharged into the ink tank 5 and absorbed by the waste ink absorption member 16. Therefore, the existence of the floating ink in the second storage section 12 of the ink tank 5 is eliminated. Therefore, even when the waste ink is newly discharged to the second storage section 12, the waste ink can satisfactorily be absorbed by the waste ink absorption member 16. The ink leakage due to overflow of the waste ink can be prevented. Finally, after the operation of the suction pump 24 ends, as shown in step 108, the total amount of the waste ink absorption and the collection time of the waste ink are recorded in the information recording medium 17 of the ink tank 5, respectively. In consequence, a series of operations of discharging the waste ink are completed.
The total amount of the waste ink absorption is obtained by adding the amount of the ink presently fed by the suction pump 24 to the total amount of the waste ink absorption read from the information recording medium 17 in the step 102 before operating the suction pump 24. The amount of the waste ink to be generated by the restorative suction and the preliminary discharge differs with the mode. In the ROM 311 or the RAM 312, information on the amount of the waste ink to be generated by each mode of restorative suction and each mode of preliminary discharge is stored. The amount of the ink fed into the second storage section 12 by the suction pump 24 is calculated based on the information. The calculation result is added to the total amount of the waste ink absorption read from the information recording medium 17. When the preliminary discharge is performed a plurality of times, the waste ink is collected from the cap 23 in some case. In this case, the amount of the waste ink preliminarily discharged the plurality of times is added. This value is newly stored in the information recording medium 17.
A value obtained by further subtracting the amount of the ink evaporated from the second storage section 12 may be stored according to the lapse time from the previous collection time of the waste ink.
As the collection time of the waste ink, a pump operating time such as a time when the operation of the suction pump 24 is started or stopped is used.
As described above, according to the ink tank 5 of the embodiment including the information holding portion 13, it can be prevented that the waste ink is discharged into the second storage section 12 in a case where the floating ink which is not absorbed by the waste ink absorption member 16 of the second storage section 12 exists. Therefore, according to this ink tank 5, when the waste ink is discharged into the second storage section 12, the ink leakage from the ink tank 5 can be prevented.
Furthermore, according to this ink tank 5, the joint portion 19 for ink collection does not have to employ a special sealed structure. Therefore, with a comparatively simple constitution and low manufacturing cost, the first ink is securely collected by the waste ink absorption member 16, and drop of reliability due to the ink leakage can be prevented.
An ink tank according to another embodiment will be described with reference to the drawings. The tank includes a light emitting portion which emits light to indicate that the waste ink collecting operation is stopped for the predetermined time period. Since the present embodiment has substantially the same constitution as that of the ink tank 5 of the above embodiment, the same members are denoted with the same reference numerals for description.
Moreover, the second storage section 12 of the ink tank 15 includes a waste ink absorption member 16 in which waste ink is collected and stored in the same manner as in the constitution shown in
As shown in
Moreover, when the waste ink is continuously discharged to the waste ink absorption member 16, the shortest time period X of the waste ink absorption corresponding to the total amount of the waste ink absorption is read from the information recording medium 17 of the ink tank 15 by the control section of the ink jet recording device. This shortest time period X of the waste ink absorption is the shortest time period when the waste ink can sufficiently be absorbed by the waste ink absorption member 16 and any floating ink does not exist in the second storage section 12 of the ink tank 15. The previous collection time of the waste ink is read from the information recording medium 17 by the control section of the ink jet recording device. However, the time is not read, when the ink tank 15 is the new tank.
Subsequently, when the suction pump 24 needs to be operated, as shown in step 103, a command for operating the suction pump 24 is generated in the ink jet recording device in the same manner as described above. When the command is generated, first as shown in step 104, a lapse time Y from the previous collection time of the waste ink up to now is calculated. Subsequently, as shown in step 105, this lapse time Y from the previous collection time of the waste ink is compared with a value of the shortest time period X of the waste ink absorption.
When Y≧X, a sufficient time elapses from the previous time when the waste ink is discharged into the ink tank 15 and absorbed by the waste ink absorption member 16. Therefore, in a case where the waste ink is absorbed by the waste ink absorption member 16, any floating ink does not exist in the ink tank 15 and the waste ink is newly discharged into the tank, it is judged that the waste ink can be absorbed by the waste ink absorption member 16. The step advances to step 106 to operate the suction pump 24. In consequence, the waste ink is discharged into the waste ink absorption member 16 of the second storage section 12 of the ink tank 5.
When Y<X, as shown in step 109, the suction pump is stopped for a predetermined time period, and waits until Y≧X is satisfied. Subsequently, the suction pump 24 operates. To allow a user to recognize that the pump is stopped for the predetermined time period, the light emitting portion 26 of the ink tank 15 emits light. When an emitted state of the light emitting portion 26 is visually recognized by the user, the user is informed that the pump is stopped. In the same manner as described above, during this stop, a sufficient time elapses from the previous time when the waste ink is discharged into the ink tank 15 and absorbed by the waste ink absorption member 16. Therefore, the existence of the floating ink in the second storage section 12 of the ink tank 15 is eliminated. Therefore, even when the waste ink is newly discharged to the second storage section 12, the waste ink can satisfactorily be absorbed by the waste ink absorption member 16. The ink leakage due to overflow of the waste ink can be prevented. Finally, after the operation of the suction pump 24 ends, as shown in step 108, the total amount of the waste ink absorption and the collection time of the waste ink are recorded in the information recording medium 17 of the ink tank 15. In consequence, a series of operations of discharging the waste ink are completed.
According to the ink tank 15 of the present embodiment, since the ink tank includes the light emitting portion 26, the user can visually easily confirm that an ink sucking operation is stopped for the predetermined time period. It is to be noted that, in addition to the light emitting portion 26, the ink tank of the embodiment may include an alarming portion (not shown) which emits warning sound, if necessary, so that the user can confirm that the ink sucking operation is stopped fro the predetermined time period owing to the warning sound.
While the present invention has been described with reference to exemplary embodiments, it is to be understood that the invention is not limited to the disclosed exemplary embodiments. The scope of the following claims is to be accorded the broadest interpretation so as to encompass all such modifications and equivalent structures and functions.
This application claims the benefit of Japanese Patent Application No. 2006-244148, filed Sep. 8, 2006, which is hereby incorporated by reference herein in its entirety.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2006-244148 | Sep 2006 | JP | national |
