BACKGROUND OF THE INVENTION
Field of the Invention
The present invention relates to a print device having a supply unit that supplies liquid stored in a liquid tank.
Description of the Related Art
A print device that ejects liquid from an ejection port and that performs printing maintains a proper ejection state by periodically cleaning (recovery processing of) a surface of the ejection port of an ejecting head that ejects the liquid. Furthermore, at the time of cleaning, a solvent (hereinafter, also referred to as wet liquid) having low volatility such as glycerin or polyethylene glycol is caused to adhere to a wiper (cleaning member) that wipes the surface of the ejection port, and the wiper also wipes the surface of the ejection port.
In addition, Japanese Patent Laid-Open No. 2007-076004 proposes a recovery device that prevents the hygroscopicity of wet liquid or the leakage of the wet liquid due to change in attitude of a print device, with a simple and inexpensive configuration.
However, the wet liquid sent out of the tank is exposed to an external environment, and thus the wet liquid may be influenced by an environmental change. In particular, the wet liquid having high viscosity at low temperature has large loss of pressure in a case where the wet liquid is moved from the tank, and thus cannot be moved.
SUMMARY OF THE INVENTION
Accordingly, in the present invention, there is provided a print device having a wet liquid supply unit corresponding to a wider environmental range, by a simple and inexpensive configuration.
Therefore, the print device according to the present invention includes: a first liquid storing unit that can store liquid; a second liquid storing unit that can store the liquid supplied from the first liquid storing unit via a liquid flow passage and can supply air to the first liquid storing unit via an air flow passage; a reverse-flow suppressing unit that suppresses a flow of the liquid from the second liquid storing unit to the first liquid storing unit in the liquid flow passage; an air flow passage valve that is provided in the air flow passage and can shut off the air flow passage; and a pressurizing unit that can pressurize the liquid in the first liquid storing unit in a state where the air flow passage is shut off by the air flow passage valve.
According to the present invention, it is possible to realize a print device having a wet liquid supply unit corresponding to a wider environmental range, by a simple and inexpensive configuration.
Further features of the present invention will become apparent from the following description of exemplary embodiments (with reference to the attached drawings).
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view showing a print device;
FIG. 2 is a diagram showing a recovery device included in the print device;
FIG. 3 is a diagram showing the recovery device included in the print device;
FIG. 4 is a longitudinal side-view showing a wet liquid supply mechanism;
FIG. 5 is a diagram showing a first processing liquid storing unit and a second processing liquid storing unit;
FIG. 6A is a diagram showing an operational mechanism of a wet liquid flow passage valve and wipers;
FIG. 6B is a diagram showing the operational mechanism of the wet liquid flow passage valve and the wipers;
FIG. 7A is a diagram showing the first processing liquid storing unit and the second processing liquid storing unit;
FIG. 7B is a diagram showing the first processing liquid storing unit and the second processing liquid storing unit;
FIG. 8A is a diagram showing the first processing liquid storing unit and the second processing liquid storing unit;
FIG. 8B is a diagram showing the first processing liquid storing unit and the second processing liquid storing unit;
FIG. 9A is a diagram showing the first processing liquid storing unit and the second processing liquid storing unit;
FIG. 9B is a diagram showing the first processing liquid storing unit and the second processing liquid storing unit;
FIG. 10A is a diagram showing the first processing liquid storing unit and the second processing liquid storing unit;
FIG. 10B is a diagram showing the first processing liquid storing unit and the second processing liquid storing unit;
FIG. 11 is a diagram showing a modification;
FIG. 12A is a diagram showing the first processing liquid storing unit and the second processing liquid storing unit;
FIG. 12B is a diagram showing the first processing liquid storing unit and the second processing liquid storing unit;
FIG. 13A is a diagram showing the first processing liquid storing unit and the second processing liquid storing unit;
FIG. 13B is a diagram showing the first processing liquid storing unit and the second processing liquid storing unit;
FIG. 14A is a diagram showing the first processing liquid storing unit and the second processing liquid storing unit;
FIG. 14B is a diagram showing the first processing liquid storing unit and the second processing liquid storing unit;
FIG. 14C is a diagram showing the first processing liquid storing unit and the second processing liquid storing unit;
FIG. 15 is a flowchart of a wiping operation by using a wiper including an opening/closing operation of a valve;
FIG. 16 is a flowchart of the opening/closing operation of the valve and contact between the wiper and a transfer member; and
FIG. 17 is a flowchart of the wiping operation by the wiper.
DESCRIPTION OF THE EMBODIMENTS
First Embodiment
Hereinafter, a description of a first embodiment of the present invention will be given with reference to the drawings. Note that the same reference numeral denotes the same or corresponding part in the respective drawings.
FIG. 1 is a perspective view showing a print device to which the present embodiment can be applied. A print device 50 is fixed so as to stride over two leg portions 55. The print device 50 includes a carriage, and a print head 1 that ejects liquid from an ejection port is mounted on the carriage 60. At print time, a print medium set to a conveyance roll holder unit 52 is fed to a print position, and the carriage 60 ejects the liquid to the print medium by using a carriage motor (not shown) and a belt transmitting unit 62 while being reciprocated in a main scanning direction shown by an arrow B.
In a case where the carriage 60 is moved to one end of the print medium, a conveyance roller 51 conveys the print medium in a sub-scanning direction shown by an arrow A by a predetermined amount. As mentioned above, an image is formed on the whole print medium by alternately repeating the print operation by the print head 1 and the conveyance operation by the conveyance roller 51. After forming the image, the print medium is cut with a cutter (not shown) and the cut print medium is mounted on a stacker 53.
A liquid supply unit 63 includes liquid tanks 5 that are detachable to the device and are separated for colors such as black, cyan, magenta, and yellow. Each liquid tank 5 is connected to a supply tube 2, and supplies and receives the liquid to/from the carriage 60 via the supply tube 2. Furthermore, the supply tube 2 connected to the carriage 60 is bent and moved corresponding to reciprocating movement of the carriage 60.
An array (ejection port array) of a plurality of ejection ports is provided on a surface (surface of the ejection port) facing the print medium in the print head 1 in a direction substantially perpendicular to the main scanning direction and is connected to the supply tube 2 in the unit of the ejection port arrays. Furthermore, a recovery device 70 is provided outside the range of the print medium range in the main scanning direction and at a position facing the surface of the ejection port of the print head 1.
FIG. 2 is a diagram showing the recovery device 70 included in the print device 50. The recovery device 70 includes a suction recovery mechanism that performs a suction recovery operation of the print head 1, and a cleaning mechanism that removes (can wipe), with the wiper, the liquid adhering to the surface of the ejection port of the print head 1. Between these, the suction recovery mechanism includes capping units having caps 4A and 4B made of rubber elastic members that adhere to the surfaces of the ejection ports of print heads 1A and 1B and that can shield the ejection ports. Moreover, the suction recovery mechanism includes the caps 4A and 4B, suction pumps 5A and 5B connected to the caps 4A and 4B via tubes 6A and 6B, and a waste ink processing member 8 connected to the suction pumps 5A and 5B via second tubes 7A and 7B.
At the time of the suction recovery operation, negative pressure is generated in a caps 4A and 4B by using the pumps 5A and 5B in a state where the caps 4A and 4B are caused to adhere (a state of being capped), respectively, to the surfaces of the ejection ports of the respective print heads. Foreign substances such as ink adhering to the ejection port by using the negative pressure, thickening ink, air bubbles, fixed ink, and dusts are sucked and are discharged to the waste ink processing member 8. Note that the suction recovery operation is executed in consideration of necessity, just before starting the printing, every predetermined print time or every print operation during the printing, or in a case where it is detected that the recovery processing of the print head is required.
FIG. 3 is a diagram showing the recovery device 70 included in the print device 50. A cleaning mechanism of the recovery device 70 includes a wiper mechanism that scrapes out (wipes) the foreign substances such as liquid or dusts adhering to the respective surfaces of the ejection ports of the print heads 1A and 1B. The wiper mechanism includes wipers 10A and 10B slidable to the respective print heads, and moving units moving the wipers 10A and 10B in the direction perpendicular to the main-scanning direction. Furthermore, the wipers 10A and 10B can suck the liquid, and the cleaning mechanism includes a wet liquid supply mechanism that can supply, to the wipers 10A and 10B, wet liquid (processing liquid) for reducing the change in wetness property of the surfaces of the ejection ports. The wet liquid supply mechanism supplies the wet liquid to the wipers 10A and 10B by bringing the wet liquid transfer member 101 into contact with the wipers 10A and 10B.
FIG. 4 is a longitudinal side-view showing the wet liquid supply mechanism according to the present embodiment. Herein, a description will be given of a configuration and an operation of the wet liquid supply mechanism. First, a description will be given of a configuration for supplying the wet liquid from a first processing liquid storing unit 102 (intermediate tank) to the wipers 10A and 10B. The first processing liquid storing unit 102 includes a wet liquid transfer member 101, and the wet liquid is transferred to the wipers 10A and 10B and is then supplied by bringing the wipers 10A and 10B into contact with a part of the wet liquid transfer member 101. The wet liquid transfer member 101 is formed of a porous body having air permeability, and can hold the wet liquid by the porous body. Furthermore, the first processing liquid storing unit (liquid storing unit) 102 includes a wet liquid holding member (liquid holding member) 102a that can hold the liquid so as to be adjacent to a wet liquid supply passage coupling unit (connecting unit) 103a.
Next, a description will be given of a configuration for replenishing the wet liquid to the first processing liquid storing unit 102 from the second processing liquid storing unit 105 that stores (can store) the wet liquid. The second processing liquid storing unit 105 is connected to a wet liquid flow passage 103 that is coupled to the wet liquid supply passage coupling unit 103a in the first processing liquid storing unit 102 and supplies the wet liquid, and is connected to an air flow passage 104 that is coupled to an air flow passage coupling unit 104a in the first processing liquid storing unit 102 and that introduces air. The wet liquid flow passage 103 includes a wet liquid flow passage valve 103b (pressurizing unit) that can shut off the flow passage, and the air flow passage 104 includes an air flow passage valve 104b that can shut off the flow passage.
The valves provided in both of the flow passages maintain a closing state in a case where the wet liquid is not supplied. The wet liquid flow passage valve 103b can change the volume while housing the liquid in addition to including a valve function, and can temporarily stores the wet liquid therein. At the time of supplying the wet liquid, the wet liquid flow passage valve 103b changes the volume along with the opening/closing operation of the valve by using a driving system which will be described later, and supplies the wet liquid from the second processing liquid storing unit 105 to the first processing liquid storing unit 102. Referring to FIG. 4, the air flow passage coupling unit 104a is arranged above the first processing liquid storing unit 102, and the wet liquid supply passage coupling unit 103a is arranged under the first processing liquid storing unit 102. However, the present invention is not limited to this. The wet liquid supply passage coupling unit 103a may be arranged so as to have the same height as that of the air flow passage coupling unit 104a, or may be arranged above the air flow passage coupling unit 104a.
FIG. 5 is a diagram showing the first processing liquid storing unit 102 with arrangement of the air flow passage coupling unit 104a above the wet liquid supply passage coupling unit 103a, and the second processing liquid storing unit 105. In a case where the air flow passage coupling unit 104a is arranged above the wet liquid supply passage coupling unit 103a, the second processing liquid storing unit 105 is arranged above the first processing liquid storing unit 102. With the configuration as mentioned above, it becomes possible, by opening both of the valves 103b and 104b, to supply the wet liquid to the first processing liquid storing unit 102 from the second processing liquid storing unit 105, due to a water head difference. The supply of the wet liquid automatically stops in a case where the air flow passage valve 104b is covered with the wet liquid. Furthermore, in a case where the wet liquid supply passage coupling unit 103a is arranged above the air flow passage coupling unit 104a, the supply of the wet liquid by a the water head difference does not become possible because of an arrangement relationship. However, the wet liquid is supplied by forced conveyance thereof by using the wet liquid flow passage valve 103b that can change the volume and the wet liquid holding member. Subsequently, a description of a configuration is given in a case where the air flow passage coupling unit 104a is arranged above the wet liquid supply passage coupling unit 103a.
FIGS. 6A and 6B are diagrams showing operational mechanisms of the wet liquid flow passage valve 103b and the wipers. FIG. 6A shows a closing state of the wet liquid flow passage valve 103b, and a configuration in which the wet liquid flow passage valve 103b shuts off the wet liquid flow passage (liquid flow passage) 103 by using a valve spring 205. Furthermore, the wet liquid flow passage valve 103b and the air flow passage valve 104b are configured to be almost simultaneously operated, and in a case where the wet liquid flow passage 103 is shut off, the air flow passage 104 is also simultaneously shut off. FIG. 6B shows an opening state of the wet liquid flow passage valve 103b. The wet liquid flow passage valve 103b performs the opening/closing operation in conjunction with operations of the wipers 10A and 10B.
The wipers 10A and 10B are held to the wiper holding member 200, and the wiper holding member 200 is reciprocated in an arrow direction by driving a motor 206 and rotating a lead screw 201 via a gear. In a case where the wiper holding member 200 is moved and comes into contact with a shaft 202 as shown in FIG. 6B, the shaft 202 is pressed and is moved by the wiper holding member 200, thereby rotating a valve opening member 203. Along with rotation of the valve opening member 203, the wet liquid flow passage valve 103b (and the air flow passage valve 104b) are opened. At this time, the wipers 10A and 10B come into contact with the wet liquid transfer member 101, thereby transferring and supplying the wet liquid. The wet liquid flow passage valve 103b is configured to change the volume by the opening/closing operation, and the volume is increased by the opening of the valve and is reduced by the closing of the valve.
FIGS. 7A and 7B are diagrams showing the second processing liquid storing unit 105 that supplies the wet liquid to the first processing liquid storing unit 102. The first processing liquid storing unit 102 does not have the wet liquid holding member, and the wet liquid flow passage valve 103c does not change the volume. Here, a description of a behavior of the wet liquid at the time of the supply is given in the configurations of the first and second processing liquid storing units shown in FIGS. 7A and 7B. As shown in FIG. 7B, in a case of opening the wet liquid flow passage valve 103c, the wet liquid having low viscosity is supplied by a water head difference because of a positional relationship between the first processing liquid storing unit 102 and the second processing liquid storing unit 105. However, in a case where the viscosity of the wet liquid becomes high, as shown in FIG. 7A, the pressure loss of the wet liquid is increased in the wet liquid flow passage 103, and the wet liquid stops in the middle of the wet liquid flow passage 103, without being supplied to the first processing liquid storing unit 102.
FIGS. 8A and 8B are diagrams showing the second processing liquid storing unit 105 that supplies the wet liquid to the first processing liquid storing unit 102. The first processing liquid storing unit 102 does not have a wet liquid holding member, and the volume is changed with the wet liquid flow passage valve 103c. Here, a description will be given of a behavior of the wet liquid at the time of supply, in the configurations of the first and second processing liquid storing units shown in FIGS. 8A and 8B. First, as shown in FIG. 8A, in a case where the wet liquid flow passage valve 103b enlarges the volume, the wet liquid having high viscosity is pulled inside the valve from both the second processing liquid storing unit 105 and the first processing liquid storing unit 102. At this time, X denotes a position on the liquid surface of the wet liquid in the wet liquid flow passage 103. Next, as shown in FIG. 8B, in a case where the wet liquid flow passage valve 103b reduces the volume, the wet liquid in the valve is pressed to both the second processing liquid storing unit 105 and the first processing liquid storing unit 102. At this time, Y denotes a position on the liquid surface of the wet liquid in the wet liquid flow passage 103.
As mentioned above, in the configurations of the first processing liquid storing unit 102 and the second processing liquid storing unit 105 as shown in FIGS. 8A and 8B, even in a case where the wet liquid flow passage valve 103b enlarges or reduces the volume, the positions X and Y on the liquid surface are only alternatively moved and the wet liquid is not supplied to the first processing liquid storing unit 102.
FIGS. 9A and 9B are diagrams showing the second processing liquid storing unit 105 that supplies the wet liquid to the first processing liquid storing unit 102. The first processing liquid storing unit 102 includes a wet liquid holding member, and the wet liquid flow passage valve 103c changes the volume. According to the present embodiment, the first processing liquid storing unit 102 and the second processing liquid storing unit 105 include configurations shown in FIGS. 9A and 9B. Here, a description will be given of the behavior of the wet liquid at the time of supplying the wet liquid in the configurations of the first and second processing liquid storing units shown in FIGS. 9A and 9B. In a case where the wet liquid flow passage valve 103b enlarges the volume as shown in FIG. 9A, the wet liquid is pulled in from both the first and second processing liquid storing units.
However, holding force of the liquid by the wet liquid holding member (reverse-flow suppressing member) 102a arranged near the wet liquid supply coupling unit 103a in the first processing liquid storing unit 102 becomes resistance, and thus the wet liquid pulled from the first processing liquid storing unit 102 side is not pulled in. The wet liquid holding member 102a functions as a member for suppressing the reverse flow, and only the wet liquid from the second processing liquid storing unit 105 side having low resistance is pulled inside wet liquid flow passage valve 103b. Then, the wet liquid in the second processing liquid storing unit 105 is moved to the wet liquid flow passage 103, and thus air is introduced from the air flow passage coupling unit 104a via the air flow passage 104. At this time, the wet liquid holding member 102a is arranged apart from the air flow passage coupling unit 104a, and thus the air is easily pulled in with low resistance.
Subsequently, as shown in FIG. 9B, in a case where the volume of the wet liquid flow passage valve 103b is reduced, the wet liquid moved inside the valve at the time of volume enlargement is pushed out to both the first processing liquid storing unit 102 and the second processing liquid storing unit 105. In a case where the wet liquid is pushed out inside the wet liquid flow passage valve 103b, the holding force of the liquid by the wet liquid holding member 102a does not work, and thus the wet liquid is pushed out to both the first processing liquid storing unit 102 and the second processing liquid storing unit 105. As mentioned above, it is possible to supply the wet liquid in the second processing liquid storing unit 105 to the first processing liquid storing unit 102 by a pumping effect of the wet liquid flow passage valve 103b, by repeating the opening/closing operation of the wet liquid flow passage valve 103b.
FIGS. 10A and 10B are diagrams showing the second processing liquid storing unit 105 that supplies the wet liquid to the first processing liquid storing unit 102. In a case where the wet liquid is gradually consumed, by the wipers 10A and 10B, from the first processing liquid storing unit 102 via the wet liquid transfer member 101, the amount of supply from the second processing liquid storing unit 105 is increased and the amount of supply may be larger than the amount of consumption. In this case, as shown in FIG. 10A, in a case where the liquid surface inside the first processing liquid storing unit 102 rises and reaches the air flow passage coupling unit 104a, an inside of the air flow passage 104 is brought into a striping state where the wet liquid and the air are alternatively introduced as shown in FIGS. 10A and 10B.
Furthermore, after sufficient passage of time, as shown in FIG. 10B, the amount of the wet liquid in the air flow passage 104 is brought into a state of being increased. As mentioned above, the wet liquid enters the air flow passage 104 and the wet liquid serves as resistance in a case of introducing the air. However, since the change in volume of the wet liquid flow passage valve 103b is substantially large, the air introduction is carried out from the air flow passage 104, and he wet liquid is supplied to the first processing liquid storing unit 102 from the second processing liquid storing unit 105.
Note that the wet liquid holding member 102a mentioned here includes sponge-like polypropylene fibers (hereinafter, referred to as PP sponge). As shown in FIGS. 9A and 9B, in a case where the wet liquid transfer member 101 and the wet liquid holding member 102a are arranged in contact with each other, the wet liquid holding member 102a is required to have capillary force lower than that of the wet liquid transfer member 101 in order to ensure the absorption of the wet liquid by the wet liquid transfer member 101. Therefore, the average pore diameter, the apparent density of the wet liquid holding member 102a and the like may be properly selected so as to maintain the above-mentioned relationship of the capillary force.
(Modification)
FIG. 11 is a diagram showing a modification of the present embodiment. In place of the wet liquid holding member 102a, there may be provided a one-directional valve 500 for preventing the reverse flow of the wet liquid in the wet liquid flow passage 103 as shown in FIG. 11.
Note that, according to the present embodiment, the wet liquid has been supplied to the first processing liquid storing unit from the second processing liquid storing unit through the use of the wet liquid flow passage valve that can change the volume, but the present invention is not limited to this, and the wet liquid may be supplied through the use of an inexpensive pump or the like.
As mentioned above, the valve that can change the volume is provided in the flow passage between the intermediate tank and the storing unit that stores the liquid and that supplies the liquid to the intermediate tank. Accordingly, it is possible to realize the print device including the wet liquid supply unit corresponding to a wider environmental range, with a simple and inexpensive configuration.
Second Embodiment
Hereinafter, there will be given a description of a second embodiment of the present invention with reference to the drawings. Note that, since the basic configuration according to the present embodiment is similar to that according to the first embodiment, only a characteristic configuration will be described below.
FIGS. 12A and 12B are diagrams showing a first processing liquid storing unit 102 and a second processing liquid storing unit 105 according to the present embodiment. According to the present embodiment, a part of the wet liquid transfer member 201 is configured to be used as a substitute for the function of the wet liquid holding member 102a. The part of the wet liquid transfer member 201 according to the present embodiment is adjacent to the wet liquid supply passage coupling unit 103a, is formed apart from the air flow passage coupling unit 104a, and is arranged in the first processing liquid storing unit 102. The supply mechanism can supply even the wet liquid having high viscosity by substituting a part of the wet liquid transfer member 201 for the function of the wet liquid holding member 102a according to the first embodiment.
FIG. 12B is an enlarged view showing the vicinity of the wet liquid supply passage coupling unit 103a. Flow resistance is generated by making a distance G between the wet liquid transfer member 201 and the wet liquid supply passage coupling unit 103a close to approximately 0 to 1 mm, thereby exhibiting a function of a member for suppressing the reverse flow at the time of pulling-in by the wet liquid flow passage valve 103b.
As mentioned above, the valve that can change the volume is provided between the intermediate tank and the storing unit that stores the wet liquid and that supplies the wet liquid to the intermediate tank. Resistance in pulling-in by the wet liquid flow passage valve 103b is generated by a part of the wet liquid transfer member 201. Accordingly, it is possible to realize the print device having the wet liquid supply unit corresponding to a wider environmental range, with a simple and inexpensive configuration.
Third Embodiment
Hereinafter, there will be given a description of a third embodiment of the present invention with reference to the drawings. Note that, since the basic configuration according to the present embodiment is similar to that according to the first embodiment, only a characteristic configuration will be described below. According to the present embodiment, in a case where the viscosity of the wet liquid becomes high at low temperature, the wet liquid is supplied by changing the opening/closing operation timing of the valve by using the configuration according to the first embodiment.
FIGS. 13A and 13B are diagrams showing a state where the viscosity of the wet liquid becomes high at low temperature by the configuration according to the first embodiment. Even in the state of low temperature, the wet liquid in the second processing liquid storing unit 105 can be supplied to the first processing liquid storing unit 102 due to the pumping effect of the wet liquid flow passage valve 103b. However, in a case where the viscosity of wet liquid 401 in the air flow passage 104 becomes high, the air sometimes cannot be introduced into a space 400.
Namely, in a case where the viscosity of the wet liquid 401 in the air flow passage 104 is high and the pressure loss is increased, as shown in FIG. 13A, the wet liquid 401 in the air flow passage 104 is not moved and shuts off the air flow passage 104, and the air cannot be introduced into the space 400. In this case, since the air is not introduced into the space 400 via the air flow passage 104, negative pressure is brought into a state of being maintained in the space 400 in a case where the wet liquid flow passage valve 103b is opened to enlarge the volume.
In a case where the viscosity of the wet liquid is low, the air having the same volume as that of the wet liquid flown out from the second processing liquid storing unit 105 by the valve flows into the space 400 of the second processing liquid storing unit 105 via the air flow passage 104. Furthermore, the wet liquid that is increased too much in the first processing liquid storing unit 102 is also returned to the second processing liquid storing unit 105 through the air flow passage 104. Therefore, a water surface 403 of the first processing liquid storing unit 102 is usually maintained so as to be almost the same height as that of the air flow passage coupling unit 104a. However, in a case where the viscosity of the wet liquid becomes high and the flow of the air flow passage 104 is shut off, the air does not flow into the second processing liquid storing unit 105, and thus the supply to the first processing liquid storing unit 102 becomes excessive. As a result, as shown in FIG. 13B, in a case where the water surface 403 in the first processing liquid storing unit 102 is increased and is over a wall of a container of the first processing liquid storing unit 102, the wet liquid is leaked outside.
Accordingly, in the present embodiment, the wet liquid is prevented from leaking out from the first processing liquid storing unit 102, depending on the opening/closing timing of the valve. Hereinafter, a description will be given of a supply method of maintaining the water level at a stable position without leakage of the wet liquid from the first processing liquid storing unit 102 even in a case where the viscosity of the wet liquid becomes high at low temperature.
FIGS. 14A to 14C are diagrams showing the first processing liquid storing unit 102 and the second processing liquid storing unit 105 according to the present embodiment. FIG. 14A shows a state where the wet liquid flow passage valve 103b is opened and the air cannot be guided with high viscosity of the wet liquid 401 and increase of pressure loss. FIG. 14B shows an opening state of the wet liquid flow passage valve 103b in a case where the state is maintained for a predetermined time. Negative pressure of the space 400 starts to gradually move the wet liquid having high viscosity in the air flow passage 104, and the negative pressure of the space 400 in the second processing liquid storing unit 105 is gradually released. The time until the negative pressure of the space 400 is released is different depending on the temperature or the like at that time.
FIG. 14C shows an opening state of the wet liquid flow passage valve 103b in a case of being maintained from the state in FIG. 14B. In this state, the wet liquid 401 in the air flow passage 104 is moved to a space 402 having a cross-sectional shape capable of carrying out gas-liquid exchange and formed in the second processing liquid storing unit 105, and thus the air can be introduced into the space 400 via the air flow passage 104. The negative pressure of the space 400 is reset by introduction of the air into the space 400. As mentioned above, since the operation is waited for a predetermined time after opening the valve, the air having the same volume as that of the wet liquid flowing out from the second processing liquid storing unit 105 flows in. Thereby, the balance between the flow-in and flow-out has been achieved, and thus the water surface 403 in the first processing liquid storing unit 102 is maintained at a stable position.
FIG. 15 is a flowchart of a wiping operation by the wipers including the opening/closing operation of the wet liquid flow passage valve 103b. Hereinafter, a description will be given of the wiping operation by the wiper including the opening/closing timing of the wet liquid flow passage valve 103b with reference to the flowchart. In step S1, the wiper is arranged at a home position. After that, in step S2, the print head is wiped by the wipers 10A and 10B. Next, in step S3, the wipers 10A and 10B come into contact with the wet liquid transfer member 101.
Then, in step S4, the wipers 10A and 10B are operated and the wet liquid flow passage valve 103b is opened by pressing a shaft 202. After the wiping by the wipers, in order to solve the problem, as soon as possible, of the reverse flow into the ejection port of the remaining ink without being wiped by wiping, near the ejection port of the print head, it is necessary to perform an operation for ejecting the ink on a cap (not shown) arranged under the wiper. Therefore, the wiper needs to be returned to the home position immediately, and thus, after movement of the print head from above the wiper, the wet liquid flow passage valve 103b is closed in step S5, and the wiper is returned to the home position in step S6.
FIG. 16 is a flowchart in a case where the wiper comes into contact with the wet liquid transfer member 101 and performs the opening/closing operation of the wet liquid flow passage valve 103b. Hereinafter, with reference to the flowchart, a description will be given of the contact of the wiper with the wet liquid transfer member 101 and the opening/closing operation of the wet liquid flow passage valve 103b. Here, control order is shown at the time of opening/closing operation of the valve without the wiping operation. In step S10, the wiper is arranged at the home position. Subsequently, in step S11, the wipers 10A and 10B comes into contact with the wet liquid transfer member 101. In addition, in step S12, the wipers 10A and 10B are operated to press the shaft 202, thereby opening the wet liquid flow passage valve 103b.
After opening the wet liquid flow passage valve 103b, in step S13, the operation is waited in order to maintain the opening state for a predetermined time. The waiting time is determined corresponding to a required time for supplying the wet liquid in a low-temperature state. After that, in step S14, the wet liquid flow passage valve 103b is closed, and in step S15, the wiper is returned to the home position. Note that the opening/closing operation of the valve without the wiping operation may be performed at any timing other than the wiping operation.
In the flowchart shown in FIG. 15, in order to suppress the reverse flow to the ejection port of the ink without being wiped, the control for closing the wet liquid supply valve is performed without setting the waiting time after opening the wet liquid supply valve. However, this does not apply in a case where the influence of reverse-flowed ink on image formation is small. Namely, the waiting time maybe set after the wiping operation. Hereinafter, a description will be given of the wiping operation by the wiper including the opening/closing operation of the wet liquid flow passage valve 103b in a case where influence of the reverse-flowed ink on the image formation is small and ignorable.
FIG. 17 is a flowchart of a wiping operation by the wiper in a case where the influence of the reverse-flowed ink on the image formation is small. In step S20, the wiper is arranged at the home position. After that, in step S21, the wipers 10A and 10B wipe the print head. Next, in step S22, the wipers 10A and 10B make contact with the wet liquid transfer member 101. Then, in step S23, the wipers 10A and 10B are operated and the shaft 202 is pressed, thereby opening the wet liquid flow passage valve 103b. After opening the wet liquid flow passage valve 103b, in step S24, the operation is waited in order to maintain the opening state for a predetermined time. Subsequently, in step S25, the wet liquid flow passage valve 103b is closed, and in step S26, the wiper is returned to the home position.
As mentioned above, the valve that can change the volume is provided between the intermediate tank and the storing unit that stores the wet liquid and supplies the wet liquid to the intermediate tank, and the operation is waited for a predetermined time after opening the valve. Therefore, it has been possible to realize the print device including the wet liquid supply unit corresponding to a wider environmental range with a simple and inexpensive configuration.
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. 2015-194153 filed Sep. 30, 2015, which is hereby incorporated by reference wherein in its entirety.
Patent Application
20170087851
