JP2009166359A - Liquid supplier and liquid injector - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a liquid supplier which supplies a liquid in a liquid supply source to the last without wasting the liquid, when supplying the liquid from an upstream side being the liquid supply source for a downstream side. <P>SOLUTION: The liquid supplier is provided with: an ink passage 16 for supplying ink from an upstream side being an ink cartridge 13 side to a downstream side: a pump 31 for pump driving by a displacement of a diaphragm 33 which increases and decreases a volume of part of the ink passage 16 as a pump chamber; and a controller 44 for detecting an ink residual amount of the ink cartridge 13. In the ink cartridge 13, a volume of an ink pack 26 containing ink is changed according to the ink residual amount. The pump 31 has a negative pressure chamber 43 separated from the pump chamber by the diaphragm 33. The controller 44 detects the ink residual amount in the ink pack 26 from a pressure change in the negative pressure chamber 43 at the time of the suction drive for sucking the ink into the pump chamber, caused in such a way that the pump 31 displaces diaphragm 33 in a direction to increase the volume of the pump chamber. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a liquid supply apparatus and a liquid ejection apparatus that supply liquid from an upstream side that is a liquid supply source side toward a downstream side where the liquid is consumed.

  Conventionally, an ink jet recording apparatus (hereinafter referred to as a “printer”) is widely known as one of liquid ejecting apparatuses. In this printer, printing is performed by ejecting ink supplied from a liquid supply source such as an ink pack accommodated in an ink cartridge (hereinafter referred to as “cartridge”) from a liquid ejecting head to a target.

Conventionally, such a printer has an ink remaining amount detecting means for detecting the remaining amount of ink in the ink pack. As the ink remaining amount detecting means, for example, the ink consumption amount is calculated by counting the number of ink ejections (number of dots) from the liquid ejecting head, and the calculated ink consumption amount is used as the full filling ink amount (initial value). There has been proposed a method for detecting the remaining amount of ink by subtracting from (see Patent Document 1).
JP-A-5-88552

  By the way, as shown in Patent Document 1, the conventional printer detects the remaining amount of ink in the ink pack by calculation based on the number of ink ejections. However, the remaining amount of ink detected by such calculation is only an estimated value and is not necessarily an accurate remaining amount of ink. That is, the remaining amount of ink remains sufficient for printing even though the remaining amount of ink is zero (that is, the ink end state) or close to zero (that is, the near end state). May be erroneously detected.

  Therefore, conventionally, in a printer in which the remaining amount of ink is detected by such a calculation, when the value of the remaining amount of ink detected by the calculation falls below a predetermined threshold value sufficiently larger than zero, the ink end (or It is estimated that the cartridge is in a near-end state, and a message indicating the necessity of replacing a cartridge containing an ink pack having a remaining amount of ink that can still be used is informed. Therefore, in such a case, there is a problem that the ink remaining in the ink pack of the cartridge to be replaced is not used and is wasted.

  The present invention has been made in view of such circumstances, and an object of the present invention is to efficiently use the liquid in the liquid supply source to the end when supplying the liquid from the upstream side serving as the liquid supply source toward the downstream side. An object of the present invention is to provide a liquid supply apparatus that can supply liquid. It is another object of the present invention to provide a liquid ejecting apparatus including such a liquid supply apparatus.

  In order to achieve the above object, a liquid supply apparatus of the present invention includes a liquid supply channel that supplies liquid from an upstream side that is a liquid supply source side toward a downstream side where the liquid is consumed, and the liquid supply channel. A pump driven by displacement of a displacement member constituting at least a part of the inner surface of the pump chamber so as to increase or decrease the volume of the pump chamber with a part of the pump chamber as a pump chamber, and a remaining amount of liquid in the liquid supply source The liquid supply device includes a liquid remaining amount detecting means for detecting the liquid, wherein the liquid supply source is configured such that the volume of the liquid storage portion in the closed space for storing the liquid changes according to the liquid remaining amount. In addition, the pump has a working fluid introduction chamber partitioned from the pump chamber by the displacement member, and the liquid remaining amount detecting means has the displacement of the pump by the pump. Increasing direction By displacing detecting the liquid remaining amount in the liquid containing portion based on the pressure change of the working fluid introduced chamber of the working fluid at the time of suction drive for sucking the liquid into the pump chamber.

  According to the above-described configuration, the liquid in the liquid storage section is sucked when the pump displaces the displacement member in the direction in which the volume of the pump chamber increases and sucks the liquid from the upstream side which is the liquid supply source side into the pump chamber. When the remaining amount becomes zero, the displacement amount of the displacement member is different from the displacement amount when the remaining amount of liquid in the liquid storage portion is necessary and sufficient. Therefore, the volume of the working fluid introduction chamber partitioned from the pump chamber by the displacement member changes, and the time required for the working fluid introduction chamber to reach a predetermined pressure by the pump operation changes. Therefore, the liquid remaining amount detecting means accurately determines the liquid remaining amount in the liquid storage portion based on a change in pressure in the working fluid introduction chamber during the suction driving of the pump without using a calculation that may cause erroneous detection. It can be detected as an end state. Therefore, when the liquid is supplied from the upstream side serving as the liquid supply source toward the downstream side, the liquid in the liquid supply source can be supplied to the end without waste.

  Further, in the liquid supply apparatus of the present invention, the remaining liquid amount detecting means detects the pressure of the working fluid in the working fluid introduction chamber at the time of the suction driving of the pump, and When the required time until the pressure of the working fluid in the working fluid introduction chamber reaches a predetermined pressure is longer than the required time in the case where the remaining amount of liquid in the liquid storage portion is necessary and sufficient, The liquid storage part detects that the liquid end state is such that the liquid remaining amount is zero.

  That is, when the remaining amount of liquid in the liquid storage part of the closed space in the liquid supply source is completely sucked out by the suction drive of the pump, the liquid can no longer be sucked from the liquid storage part. Is smaller than the displacement when the remaining amount of liquid in the liquid storage portion is necessary and sufficient. For this reason, since the volume in the working fluid introduction chamber does not become small when the pump is driven to suck, the time required until the working fluid introduction chamber reaches a predetermined pressure by the pump operation is lengthened. Therefore, according to the above configuration, the time required for the pressure of the working fluid in the working fluid introduction chamber to reach a predetermined pressure after the start of suction of the pump is required when the remaining amount of liquid in the liquid container is necessary and sufficient. By detecting that the time is longer than the time, the liquid end state can be reliably detected.

In the liquid supply apparatus of the present invention, the working fluid is air.
According to the above configuration, since the working fluid is air, unlike the case where the working fluid is a liquid such as silicon oil, the response of the pump drive can be improved by the low viscosity. Further, when the working fluid supply path is formed of a tube, the tube weight is reduced.

In the liquid supply apparatus of the present invention, the liquid supply source is a flexible liquid storage bag, and the inside of the closed space of the liquid storage bag is the liquid storage portion.
According to the above configuration, it is possible to obtain a liquid supply source in which the volume of the liquid storage unit in the closed space for storing the liquid changes according to the remaining amount of the liquid with a simple configuration.

In the liquid supply apparatus according to the present invention, when the liquid remaining amount detecting means detects that the liquid remaining amount in the liquid storage portion is in a liquid end state, the driving of the pump is stopped.
According to the above configuration, when the liquid cannot be sucked even if the pump is driven and the pump is continuously driven, the unnecessary driving of the pump is stopped to increase the pump driving load. Can be suppressed.

The liquid ejecting apparatus of the present invention includes a liquid ejecting head that ejects liquid and the liquid supply apparatus having the above-described configuration.
According to the said structure, the effect similar to invention of the said liquid supply apparatus is acquired.

Hereinafter, an embodiment in which the present invention is embodied in an ink jet printer (hereinafter referred to as “printer”) will be described with reference to the drawings.
As shown in FIG. 1, a printer 11 as a liquid ejecting apparatus in this embodiment includes a recording head 12 as a liquid ejecting head that ejects ink (liquid) to a target (not shown), and a recording head 12. An ink supply device 14 is provided as a liquid supply device for supplying ink contained in the ink cartridge 13. The ink cartridge 13 and the ink supply device 14 constitute an ink supply system 15 as a liquid supply system. In the ink supply device 14, the upstream end is connected to the ink cartridge 13 and the downstream end is connected to the recording head 12, and the upstream side that is the ink cartridge 13 side is changed to the downstream side that is the recording head 12 side. An ink flow path 16 (liquid supply flow path) for supplying ink is provided.

  The printer 11 is provided with a plurality of ink supply devices 14 corresponding to the number of colors (types) of ink used in the printer 11. However, since the configurations are the same, FIG. 1 illustrates one ink supply device 14 that supplies ink of any one color together with the recording head 12 and one ink cartridge 13. In the following, as an example, ink is supplied from the upstream ink cartridge 13 toward the downstream recording head 12 via the ink flow path 16 of one ink supply device 14 shown in FIG. I will explain.

  As shown in FIG. 1, in the recording head 12, a plurality (four in this embodiment) of nozzles 17 corresponding to the number of ink supply devices 14 are opened in a nozzle forming surface 12 a facing a platen (not shown). Is formed. Ink is supplied to the nozzles 17 from the ink flow paths 16 of the corresponding ink supply devices 14 via the valve units 18. That is, the valve unit 18 is provided with a pressure chamber (not shown) for temporarily storing ink flowing from the ink flow path 16 so as to communicate with the nozzle 17, and ink is ejected from the nozzle 17 into the pressure chamber. In this case, an amount of ink corresponding to the amount of ink consumed by the ink jetting appropriately flows from the ink flow path 16 based on a valve opening / closing operation (not shown).

  In addition, a maintenance unit 19 for cleaning the recording head 12 is provided at a home position where the recording head 12 is not printed in the printer 11 so as to eliminate clogging of the nozzles 17 of the recording head 12. The maintenance unit 19 includes a cap 20 that can come into contact with the nozzle forming surface 12a of the recording head 12 so as to surround the nozzle 17, a suction pump 21 that is driven when sucking ink from the cap 20, and the suction unit 21. A waste liquid tank 22 is provided in which ink sucked from the cap 20 as the pump 21 is driven is discharged as waste ink. During cleaning, the suction pump 21 is driven in a state where the cap 20 is moved and brought into contact with the nozzle formation surface 12 a of the recording head 12, thereby generating a negative pressure in the internal space of the cap 20, thereby generating the inside of the recording head 12. The ink thickened from the ink or the ink mixed with bubbles is sucked and discharged toward the waste liquid tank 22.

  On the other hand, the ink cartridge 13 includes a case 23 formed of a synthetic resin material in a substantially box shape. An ink outlet 24 as a liquid outlet for leading ink to the outside is formed on the side wall of the case 23, and a communication portion 25 that communicates with the case 23 with the ink outlet 24 serving as a base end. A through-hole is formed so as to function as a path. In addition, the case 23 is made of a flexible liquid storage bag, and stores an ink pack 26 in which ink is enclosed (stored) in a closed space serving as a liquid storage portion. In addition, a cylindrical ink lead-out member 27 is provided at one end of the ink pack 26 to lead the ink sealed inside to the outside. The ink lead-out member 27 is fitted into the communication portion 25 of the case 23. By combining, the ink pack 26 is fixed at the storage position in the ink cartridge 13. When the ink cartridge 13 is connected to the ink supply device 14, an ink supply needle 28 that protrudes from the ink supply device 14 to form the upstream end of the ink flow path 16 with respect to the ink outlet port 24 is inserted. It has come to be. At this time, the periphery of the ink supply needle 28 is sealed by a seal member (not shown) in the ink outlet port 24. In addition, a second one-way valve 29 for suction that allows only passage of ink from the upstream side that is the ink pack 26 side to the downstream side that is the ink outlet port 24 side is provided inside the ink lead-out member 27. It has been. The second one-way valve 29 includes a valve body 29a capable of reciprocating in the left-right direction between a valve opening position and a valve closing position in accordance with a change in ink pressure or ink flow, and a valve movable in the valve opening direction. It is comprised by the latching | locking part 29b which latches the body 29a. The upper wall of the case 23 is formed with an air communication hole 30 that allows the inside of the case 23 to communicate with the atmosphere, so that atmospheric pressure acts on the outer surface of the ink pack 26 that contains ink. Yes.

Next, the configuration of the ink supply device 14 will be described in detail.
As shown in FIG. 1, the ink supply device 14 includes a pump 31 that pressurizes and supplies ink sucked from the ink cartridge 13 side via the ink flow path 16 toward the recording head 12 side. The pump 31 has a pump case 32 having a substantially box shape, and the inside of the pump case 32 is divided into two chambers, left and right, by a diaphragm 33 as a displacement member. The diaphragm 33 is biased toward the left wall surface of the pump case 32 by the biasing force of the coil spring 34 sandwiched between the right wall surface of the pump case 32. In this embodiment, the pump case 32, the diaphragm 33, and the coil spring 34 constitute a pulsating pump 31, and a volume-variable space region surrounded by the diaphragm 33 and the left wall surface of the pump case 32. Functions as a pump chamber 35 in the pump 31. At this time, the diaphragm 33 constitutes a part of the inner surface of the pump chamber 35. A flow path opening / closing valve 36 that can open and close the ink flow path 16 is provided at a position upstream of the pump chamber 35 in the ink flow path 16.

  Further, one end (upstream end) of an ink supply tube 37 constituting a part of the ink flow path 16 in the ink supply device 14 is connected to the pump chamber 35, and the other end (downstream end) of the ink supply tube 37. ) Is connected to the valve unit 18 on the recording head 12 side. Then, a first discharge unit that allows only ink to pass from the upstream side, which is the pump chamber 35 side, to the downstream side, which is the recording head 12 side, is located at a position where the pump 31 is connected to the ink supply tube 37. A one-way valve 38 is provided. As in the case of the second one-way valve 38, the first one-way valve 38 reciprocates in the left-right direction between the valve opening position and the valve closing position as the ink pressure changes or the ink flows. It comprises a possible valve body 38a and a locking portion 38b for locking the valve body 38a movable in the valve opening direction.

  In addition, a decompression pump 40, a pressure detector 41, and an atmosphere release valve 42 are connected to the bottom wall of the pump case 32 via an air flow path 39. That is, the decompression pump 40 is connected to a space region functioning as a variable volume negative pressure chamber 43 formed by being surrounded by the diaphragm 33 and the right wall surface of the pump case 32 via the air flow path 39. The decompression pump 40 generates a negative pressure by its driving, and similarly generates a negative pressure in the negative pressure chamber 43 connected via the air flow path 39. In addition, the pressure detector 41 detects the pressure in the negative pressure chamber 43 connected via the air flow path 39 and outputs the detection result to the control device 44. Then, when the pressure in the negative pressure chamber 43 falls below a predetermined threshold by driving the decompression pump 40, the control device 44 stops driving the decompression pump 40 and opens the atmosphere release valve 42. As a result, the inside of the negative pressure chamber 43 is opened to the atmosphere to eliminate the negative pressure state.

  FIG. 1 illustrates a configuration in which one decompression pump 40, a pressure detector 41, and an air release valve 42 are provided for each of a plurality of ink supply devices 14 corresponding to each ink color. However, this may be configured as follows. That is, the connection end side of the air flow path 39 connected to the negative pressure chamber 43 of the pump 31 of the ink supply device 14 branches to correspond to the number of installed ink supply devices 14 corresponding to each ink color. In addition, each connection end of the branched air flow path 39 may be connected to the negative pressure chamber 43 of the pump 31 of the corresponding ink supply device 14. If comprised in this way, the ink supply apparatus 14 of each color can be driven only by providing the decompression pump 40, the pressure detector 41, and the air release valve 42 with respect to the some ink supply apparatus 14, The printer 11 can be downsized.

Therefore, the operation of the printer 11 configured as described above will be described below with particular attention paid to the operation of the ink supply device 14.
First, as a premise, the state shown in FIG. 1 is immediately after replacement of the old and new ink cartridges 13, and the diaphragm 33 of the pump 31 is displaced to the left wall surface side of the pump case 32 by the urging force of the coil spring 34. The air release valve 42 is assumed to be in a closed state.

  When the ink supply device 14 supplies ink from the ink cartridge 13 to the recording head 12 side from the state shown in FIG. 1, first, the decompression pump 40 is driven to drive the pump 31. Then, the decompression pump 40 generates a negative pressure, and the negative pressure chamber 43 of the pump 31 connected to the decompression pump 40 via the air flow path 39 enters a negative pressure state. Therefore, the diaphragm 33 is elastically deformed (displaced) toward the negative pressure chamber 43 against the biasing force of the coil spring 34, and the volume of the negative pressure chamber 43 is reduced. Then, as the volume of the negative pressure chamber 43 decreases, the volume of the pump chamber 35 of the pump 31 that is partitioned from the negative pressure chamber 43 via the diaphragm 33 increases (see FIG. 2).

  As the volume of the pump chamber 35 increases, the inside of the pump chamber 35 becomes in a negative pressure state, and the negative pressure is downstream of the valve body 29a constituting the second one-way valve 29 via the supply needle 28. Acts from. Then, the valve body 29a is displaced to the right (the valve opening direction) based on the pressure difference with the ink pressure acting from the ink pack 26 side, which is the upstream side of the second one-way valve 29. As a result, the ink pack 26 and the pump chamber 35 communicate with each other, and the ink stored in the ink pack 26 is sucked into the pump chamber 35 through the ink flow path 16. That is, the pump 31 is driven for suction.

  On the other hand, during the suction driving of the pump 31, the negative pressure in the pump chamber 35 also acts on the upstream side of the first one-way valve 38. Here, the pressure in the pump chamber 35 is lower than that in the ink supply tube 37, and the one-way valve 38 is closed by the valve body 38 a moving to the right side based on the pressure difference between the pump chamber 35 and the ink supply tube 37. It becomes a state.

  Then, in the state shown in FIG. 2, in order to determine whether or not the pump 31 is shifted to the discharge drive, the pressure accumulated in the negative pressure chamber 43 by the drive of the decompression pump 40 is detected by the pressure detector 41. To detect. Then, the control device 44 determines that the volume of the pump chamber 35 is maximized when the detection result reaches a preset threshold value, and stops the drive of the decompression pump 40 to shift the pump 31 to the discharge drive. At the same time, the negative pressure chamber 43 in the negative pressure state is opened to the atmosphere by opening the atmospheric release valve 42. Then, the diaphragm 33 of the pump 31 is urged toward the pump chamber 35 by the coil spring 34.

  That is, the pump 31 urges the diaphragm 33 in the direction of decreasing the volume of the pump chamber 35. Therefore, the inside of the pump chamber 35 is pressurized, and the pressure is upstream of the pump chamber 35 with respect to the valve body 29a constituting the second one-way valve 29 via the ink flow path 16. By acting from the downstream side, the valve body 29a is displaced in the valve closing direction. As a result, the ink pack 26 and the ink flow path 16 are disconnected from each other by the closing operation of the second one-way valve 29, and the ink from the ink cartridge 13 to the pump chamber 35 is passed through the second one-way valve 29. Is stopped, and the ink discharged from the pump chamber 35 along with the discharge drive of the pump 31 is restricted from flowing back to the ink cartridge 13 through the second one-way valve 29.

  On the other hand, when the pump 31 is pressurized, the ink pressure in the pump chamber 35 also acts on the upstream side of the first one-way valve 38. Therefore, the valve body 38a in which the discharge pressure of the pump 31 is in the closed state is opened, and the pump chamber 35 and the ink supply tube 37 communicate with each other through the first one-way valve 38. As a result, ink is supplied from the pump chamber 35 to the valve unit 18 through the ink supply tube 37 in a pressurized state.

  After that, there is a state in which the discharge pressure of the ink pressurized by the diaphragm 33 and discharged from the pump chamber 35 is balanced in each flow path area downstream of the second one-way valve 29 in the ink flow path 16. Maintained. Thereafter, when ink is ejected from the recording head 12 toward the target, an amount of ink corresponding to the amount of ink consumed by the ink ejection is from the ink flow path 16 through the valve unit 18 to the recording head 12 side. To be supplied. Therefore, as the ink is consumed on the downstream side (recording head 12 side), the volume of the pump chamber 35 is increased by the biasing force of the coil spring 34 on the downstream side where the ink amount corresponding to the consumed amount becomes the recording head 12 side. Is supplied in a pressurized state based on the pressing force of the diaphragm 33 biased in the direction in which the pressure decreases. Since the pressurized state in the pump chamber 35 is generated by the biasing force of the coil spring 34, the pressurized state can be maintained without separately providing a device for pressurizing the pump chamber 35. . Further, when a device having the functions of a pressurization generator and a negative pressure generator is applied as a drive source of the pump 31, a complicated control configuration is required to maintain the pressurization state in the pump chamber 35. However, when the coil spring 34 is applied as the drive source of the pump 31, the pressurized state in the pump chamber 35 can be more easily maintained.

  As a result of the consumption of ink, the volume in the pump chamber 35 gradually decreases, and finally the diaphragm 33 is displaced to the vicinity of the contact position with the left wall surface of the pump case 32 that minimizes the volume of the pump chamber 35. (Figure 3). In this state, since the ink cannot be supplied to the recording head 12 side, the controller 44 drives the decompression pump 40 again after closing the atmosphere release valve 42, so that the decompression pump 40 generates a negative pressure. Thus, the negative pressure chamber 43 is in a negative pressure state, and the diaphragm 33 is elastically deformed (displaced) toward the negative pressure chamber 43 against the urging force of the coil spring 34. That is, the pump 31 starts suction driving again.

  As a result, the diaphragm 33 is displaced in the direction in which the volume of the pump chamber 35 is increased, so that the inside of the pump chamber 35 is in a negative pressure state. Therefore, the valve body constituting the second one-way valve 29 by the action of the negative pressure. 29a moves in the valve opening direction. Accordingly, the ink pack 26 and the ink flow path 16 communicate with each other via the second one-way valve 29, and the ink is again sucked into the pump chamber 35 from the ink pack 26. Thereafter, the discharge drive of the pump 31 similar to the above is executed, and ink is pressurized and supplied from the pump chamber 35 to the recording head 12 via the ink supply tube 37.

  By the way, in the printer 11, the volume of the ink pack 26 in the ink cartridge 13 corresponds to the decrease in the remaining amount of ink as the ink is consumed on the downstream side of the ink flow path 16 such as ink ejection from the recording head 12. Will decrease and will wither. When the remaining amount of ink in the ink pack 26 becomes less than the amount of ink required for printing by ejecting ink from the recording head 12, the ink cartridge 13 is used for subsequent printing. New and old replacement is required. Therefore, in the present embodiment, the remaining amount of ink in the ink pack 26 is detected as follows.

  In other words, when the pump 31 is driven by suction and the second one-way valve 29 is opened as the decompression pump 40 is driven, the ink pack 26 is deflated so that the amount of ink corresponding to the amount of decrease in the volume of ink is reduced. Is sucked into the pump chamber 35 from the ink pack 26 side. Further, since the pressure in the negative pressure chamber 43 decreases as the pump 31 is driven to suck, the pressure detector 41 connected to the negative pressure chamber 43 via the air flow path 39 starts detecting the pressure. When this detection result is output to the control device 44, the control device 44 reaches the predetermined pressure (that is, the pressure at the time when the suction drive of the pump 31 is normally completed). The time required for the measurement is measured, and the value of the measured time required is set and stored in advance as the value of the time required corresponding to the displacement of the diaphragm 33 to the position where the volume of the negative pressure chamber 43 is minimized. It is determined whether the threshold value for use is exceeded. Based on the determination result, the presence / absence of the remaining amount of ink in the ink pack 26 is detected.

  Here, when the ink remaining amount in the ink pack 26 is a necessary and sufficient amount for ink ejection from the recording head 12 at the time of printing, the diaphragm 33 is moved to the negative pressure chamber 43 in accordance with the suction drive of the pump 31. It will be displaced to a position that minimizes the volume. Therefore, the control device 44 determines that the value of the required time measured based on the detection signal of the pressure detector 41 is within the determination threshold value, so that the remaining ink amount in the ink pack 26 is in the ink end state. Detect not.

  On the other hand, when the ink near-end state in which the remaining amount of ink in the ink pack 26 is very small, the remaining little ink remaining in the ink pack 26 from the ink pack 26 side as the pump 31 is driven by suction. When the ink is exhausted into the pump chamber 35, the ink remaining amount becomes zero, and the ink pack 26 cannot be deflated so as to further reduce the volume. Then, since the diaphragm 33 of the pump 31 ends with a small amount of ink flowing into the pump chamber 35 from the ink pack 26 side, the diaphragm 33 cannot be displaced further to the negative pressure chamber 43 side. The volume of the negative pressure chamber 43 remains larger than the minimum value of the volume of the negative pressure chamber 43 in a normal state and does not change.

  The pressure detector 41 detects a predetermined pressure value when the decompression pump 40 further sucks air by the volume difference, and outputs a detection signal to the control device 44. Then, the control device 44 detects that the remaining amount of ink in the ink pack 26 is in the ink end state by determining that the value of the required time measured based on the detection signal is larger than the determination threshold value. .

  As described above, when the control device 44 detects that the ink remaining amount in the ink pack 26 is in the ink end state, the control device 44 replaces the ink cartridge 13 containing the ink pack 26 in such an ink end state. A control signal for notifying the necessity is output, and a message to that effect is displayed on a display panel (not shown). Further, since the ink cannot be sucked from the ink pack 26 even if the pump 31 is driven for suction, the decompression pump 40 is stopped to stop unnecessary suction driving of the pump 31.

According to the present embodiment, the following effects can be obtained.
(1) In the above-described embodiment, the pump 31 displaces the diaphragm 33 in the direction in which the volume of the pump chamber 35 increases, and sucks ink into the pump chamber 35 from the upstream side on the ink cartridge 13 side. When the ink remaining amount in the ink pack 26 becomes zero, the displacement amount of the diaphragm 33 is different from the displacement amount when the ink remaining amount in the ink pack 26 is necessary and sufficient. Therefore, the volume of the negative pressure chamber 43 partitioned from the pump chamber 35 by the diaphragm 33 changes, and the time required for the inside of the negative pressure chamber 43 to reach a predetermined pressure by the pump operation changes. Therefore, the control device 44 accurately does not depend on a calculation that may erroneously detect the remaining amount of ink in the ink pack 26 based on the pressure change in the negative pressure chamber 43 during the suction drive of the pump 31. It can be detected that the ink is in an end state. Therefore, when ink is supplied from the upstream side, which is the ink cartridge 13 side, toward the downstream side, the ink in the ink pack 26 can be supplied to the end without waste.

  (2) Further, the control device 44 sets the remaining amount of ink in the ink pack 26 for which the time required until the air pressure in the negative pressure chamber 43 reaches a predetermined pressure after the suction drive of the pump 31 is started is set. Is longer than the required time when it is necessary and sufficient, it is determined that the remaining amount of ink in the ink pack 26 is in the ink end state. That is, when the ink remaining amount in the ink pack 26 in the closed space in the ink cartridge 13 is completely sucked by the suction drive of the pump 31, the ink cannot be sucked further from the ink pack 26. The displacement amount of the diaphragm 33 is smaller than the displacement amount when the remaining amount of ink in the ink pack 26 is necessary and sufficient. For this reason, the volume in the negative pressure chamber 43 at the time of suction driving of the pump 31 remains large and does not change, so the time required for the pump operation to reach the predetermined pressure in the negative pressure chamber 43 becomes longer. Therefore, the control device 44 is required when the time required for the air pressure in the negative pressure chamber 43 to reach a predetermined value after the suction of the pump 31 reaches the predetermined value is sufficient for the remaining amount of ink in the ink pack 26. By detecting that the time is longer than the required time, it is possible to reliably detect the ink end state.

  (3) In the above embodiment, air is used as the working fluid for driving the pump 31. Therefore, unlike the case where a liquid such as silicon oil is used as the working fluid, the response of the pump drive can be improved by the low viscosity. Further, when the working fluid supply path is formed of a tube, the tube weight is reduced.

  (4) In the above embodiment, the ink cartridge 13 stores the flexible ink pack 26 therein, and stores the ink in the ink pack 26 (liquid storage portion in the closed space). Therefore, a liquid supply source (ink pack 26) in which the volume of the liquid storage part in the closed space for storing the liquid (ink) changes according to the remaining amount of the liquid (ink) can be obtained with a simple configuration.

  (5) In the above embodiment, when the control device 44 detects that the ink remaining amount in the ink pack 26 is in the ink end state, the ink supply device 14 stops driving the decompression pump 40. Therefore, if ink cannot be sucked even if the suction drive of the pump 31 is continued due to the ink end state, the driving load of the decompression pump 40 is reduced by stopping the further unnecessary decompression pump 40 drive. It can suppress becoming excessive.

In addition, you may change the said embodiment as follows.
In the above embodiment, the liquid supply source having the liquid storage portion in the closed space inside is not limited to the ink pack 26 as a flexible liquid storage bag. For example, an ink storage chamber as a liquid storage portion is formed in the ink cartridge 13, and a sealing member for sealing the ink is floated on the liquid surface of the ink in the ink storage chamber. It is good also as a structure made into the liquid storage part from which volume changes in closed space. In this case, the ink cartridge 13 is a liquid supply source. In short, it is only necessary to have a liquid storage section in a closed space whose volume changes according to the remaining amount of liquid.

In the above embodiment, air is used as the working fluid for pressurizing or depressurizing the inside of the ink cartridge 13, but a liquid such as silicon oil may be used as the working fluid.
In addition, “liquid” in this specification includes liquids other than ink (including inorganic solvents, organic solvents, solutions, liquid resins, liquid metals (metal melts), etc.) and functional material particles. It also includes fluids that are dispersed or mixed, and fluids such as gels. Examples of the liquid ejecting apparatus that ejects or discharges such “liquid” include, for example, electrode materials and color materials (pixel materials) used for manufacturing liquid crystal displays, EL (electroluminescence) displays, and surface-emitting displays. Liquid ejecting device that ejects a liquid material that contains materials such as dispersed or dissolved materials, liquid ejecting device that ejects bio-organic materials used in biochip manufacturing, and liquid ejecting that ejects liquid as a sample used as a precision pipette It may be a device. In addition, transparent resin liquids such as UV curable resin to form liquid injection devices that pinpoint lubricant oil onto precision machines such as watches and cameras, and micro hemispherical lenses (optical lenses) used in optical communication elements. A liquid ejecting apparatus that ejects liquid onto the substrate, a liquid ejecting apparatus that ejects an etching solution such as acid or alkali to etch the substrate, and a fluid ejecting apparatus that ejects a fluid such as a gel (eg, physical gel) It may be.

FIG. 2 is a schematic diagram of a liquid ejecting apparatus in the present embodiment. FIG. 3 is a schematic diagram of a liquid ejecting apparatus when a pump is driven for suction. FIG. 3 is a schematic diagram of a liquid ejecting apparatus when a pump is driven to discharge.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 12 ... Recording head as a liquid ejecting head, 14 ... Ink supply apparatus as a liquid supply apparatus, 16 ... Ink flow path as a liquid supply flow path, 26 ... Ink pack as a liquid supply source, 31 ... Pump, 33 ... Displacement A diaphragm as a member, 35... A pump chamber, 43... A negative pressure chamber as a working fluid introduction chamber, and 44.

Claims (6)

A liquid supply flow path for supplying liquid from the upstream side which is the liquid supply source side toward the downstream side where the liquid is consumed;
A pump that drives the pump by displacing a displacement member that constitutes at least a part of the inner surface of the pump chamber so as to increase or decrease the volume of the pump chamber using a part of the liquid supply flow path as a pump chamber;
A liquid supply device comprising a liquid remaining amount detecting means for detecting a remaining amount of liquid in the liquid supply source,
The liquid supply source is configured such that the volume of the liquid storage portion of the closed space that stores the liquid changes according to the remaining amount of liquid,
The pump has a working fluid introduction chamber partitioned from the pump chamber by the displacement member,
The liquid remaining amount detecting means detects the amount of working fluid in the working fluid introduction chamber when the pump displaces the displacement member in a direction in which the volume of the pump chamber increases and sucks the liquid into the pump chamber. A liquid supply apparatus that detects a remaining amount of liquid in the liquid container based on a pressure change. The liquid supply apparatus according to claim 1,
The liquid remaining amount detecting means detects the pressure of the working fluid in the working fluid introduction chamber during the suction driving of the pump, and the pressure of the working fluid in the working fluid introduction chamber after the start of suction. When the required time until the pressure reaches a predetermined pressure is longer than the required time in the case where the remaining amount of liquid in the liquid storage unit is necessary and sufficient, the liquid storage unit has zero liquid remaining. A liquid supply device that detects that the liquid end state is. The liquid supply apparatus according to claim 1 or 2,
The liquid supply apparatus, wherein the working fluid is air. In the liquid supply apparatus according to any one of claims 1 to 3,
The liquid supply device is a liquid supply bag having flexibility, and the inside of a closed space of the liquid storage bag is the liquid storage unit. In the liquid supply apparatus according to any one of claims 1 to 4,
The liquid supply device according to claim 1, wherein when the liquid remaining amount detecting means detects that the liquid remaining amount in the liquid storage portion is in a liquid end state, the driving of the pump is stopped. A liquid ejecting apparatus comprising: a liquid ejecting head that ejects liquid; and the liquid supply apparatus according to claim 1 that supplies the liquid to the liquid ejecting head. .

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