JP3915185B2 - Inkjet recording device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an ink jet recording apparatus that performs recording operation by ejecting ink onto a recording medium.
[0002]
[Prior art]
Conventionally, as described in, for example, JP-A-8-72266, in a suction pump of an ink jet recording apparatus, a pair of piston members are connected to each other in a cylindrical casing in order to enable various controls. It is known that a pump chamber having a variable volume is provided between the piston members.
[0003]
[Problems to be solved by the invention]
However, at the time of capping when the suction cap is in close contact with the nozzle surface of the recording head, the suction port of the suction pump is closed by the piston member, so that when the suction cap is in close contact with the nozzle surface, the suction cap is elastically deformed. Then, the air inside is compressed and acts on the nozzle hole, so that a so-called meniscus is broken and air bubbles may enter the recording head.
[0004]
In view of this, for example, as disclosed in Japanese Patent Application Laid-Open No. 5-169680, an ink discharge port also functions as an air communication hole, and when the suction cap is capped, the inside of the suction cap is opened to the atmosphere. This suction pump has a structure having only one piston member, and cannot be applied to a suction pump having two piston members as described above.
[0005]
SUMMARY An advantage of some aspects of the invention is that it provides an ink jet recording apparatus that can open the inside of a suction cap to the atmosphere when the suction cap is capped.
[0006]
[Means for Solving the Problems]
The present invention provides a recording head that performs a recording operation by discharging ink onto a recording medium, a suction cap that can be brought into contact with and separated from the nozzle surface so as to cover the nozzle surface of the recording head so as to be openable and closable, and the recording through the suction cap. It is assumed that the ink jet recording apparatus includes a suction pump that sucks ink from the nozzle holes of the head, and a pump control unit that controls the operation of the suction pump in conjunction with the contact and separation operation of the suction cap.
[0007]
In the ink jet recording apparatus according to the first aspect of the present invention, in the ink jet recording apparatus, the suction pump has a suction port connected to the suction cap and a discharge port for discharging the sucked ink at an interval in the axial direction. A cylindrical pump casing, and first and second piston members slidably fitted inside the pump casing; The suction port and the discharge port are provided in this order from one end side of the pump casing, A first piston member is disposed on one end side of the pump casing, and a variable-volume pump chamber is formed between the first and second piston members. In a state where the cap covers the nozzle surface of the recording head, the pump chamber is connected to the suction port and the piston member is relatively moved so as to expand, and the pump chamber is connected to the discharge port. A second control for moving both piston members relative to each other so as to compress the first piston member and the second piston member until the suction cap covers the nozzle surface of the recording head; And a third control for placing the suction port in a state where the suction port is opened and opened to the atmosphere through the pump chamber and the discharge port, and performing the third control. After the suction cap covers the nozzle surface of the recording head, the first piston member holds the suction port with respect to the pump chamber while maintaining the volume of the pump chamber between the first and second piston members. The first and second piston members are moved to a closing position, and then the two piston members are relatively moved so that the pump chamber has a minimum volume with the pump chamber connected to the discharge port. To do.
[0008]
Therefore, according to the first aspect of the present invention, in the state where the suction cap covers the nozzle surface of the recording head, the pump control means connects both the pump chambers of the suction pump to the suction port and expands both of the suction pumps. The piston member is relatively moved to perform a suction operation. Further, the pump control means moves the piston members relative to each other so as to connect and compress the pump chamber to the discharge port, and the discharge operation is performed. Further, until the suction cap covers the nozzle surface of the recording head, the pump control means positions the first and second piston members at an interval across the suction port and the discharge port, and the suction port Is opened to the atmosphere through the pump chamber and the discharge port, so that when the suction cap covers the nozzle surface of the recording head, even if the suction cap is elastically deformed, the air inside thereof is not compressed, Therefore, there is no possibility that the so-called meniscus is broken by acting on the nozzle holes of the recording head and bubbles are allowed to enter the recording head. Then, after the suction cap covers the nozzle surface, the first piston member closes the suction port with respect to the pump chamber while maintaining the volume of the pump chamber between the first and second piston members. Since the first and second piston members are moved to the positions, the pump chamber is not compressed, so that there is no possibility that air acts on the nozzle hole and breaks the meniscus. Then, the two piston members are moved relative to each other so as to have a minimum volume in a state in which the pump chamber is connected to the discharge port, so that suction is possible. Suction is performed with a small negative pressure, and ink bubbling is suppressed. As a result, when the suction cap covers the nozzle surface of the recording head, even if the suction cap is elastically deformed, the air inside the suction cap is not compressed. There is no risk of breaking and allowing bubbles to enter the recording head.
[0009]
The invention of claim 2 is the inkjet recording apparatus of claim 1, Said The pump control means positions the first piston member closer to one end of the pump casing than the suction port until the suction cap covers the nozzle surface of the recording head, and the second piston member from the discharge port. Is also located on the other end side of the pump casing.
[0010]
Therefore, according to the invention of claim 2, the first piston member is positioned closer to one end side of the pump casing than the suction port until the suction cap covers the nozzle surface of the recording head, and the second piston Since the member is positioned on the other end side of the pump casing from the discharge port, both the suction port and the discharge port are opened in the pump chamber, and the suction port is opened to the atmosphere. As a result, when the suction cap covers the nozzle surface of the recording head, the air inside the suction cap is released to the atmosphere through the suction port.
[0011]
According to a third aspect of the invention, in the ink jet recording apparatus of the second aspect, the pump control means moves the piston members to the suction port side while the pump chamber is in a minimum volume state, and then 1 is performed.
[0012]
Therefore, according to the invention of claim 3, both piston members are moved to the suction port side while the pump chamber is in a minimum volume state, and then the first control is performed to perform the suction operation. it can.
[0013]
According to a fourth aspect of the present invention, in the ink jet recording apparatus according to any one of the first to third aspects, the pump control means is the third control, Second control, A series of operations including the first control and the second control are performed in this order, and after performing the series of operations, the operation is stopped in a state where the third control is performed.
Therefore, according to the invention of claim 4, after the discharging operation, both piston members are returned to the state where the third control which is the initial state (standby state) is performed and stopped.
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0014]
FIG. 1 is a schematic perspective view showing the overall configuration of the ink jet recording apparatus. In FIG. 1, an ink jet recording apparatus 1 includes a cylindrical platen roller 3 rotatably supported on a printer frame 2 by a rotation shaft (not shown) extending in the left-right direction. The platen roller 3 conveys printing paper 4 (recording medium) supplied from a paper feeding cassette or a manual paper feeding unit while facing the recording head 5, and constitutes a part of a so-called paper feeding mechanism LM. ing. The recording head 5 is an ink jet type that has a nozzle hole for ejecting ink droplets on the printing paper 4 and performs a recording operation on the printing paper 4. The paper feeding mechanism LM drives the paper feeding mechanism LM. An LF motor 14 (see FIG. 5) is provided as a paper feed motor for transporting the printing paper 4.
[0015]
The printing paper 4 is supplied in the direction of arrow A from a paper supply port (not shown) at the back of the printer frame 2, and is fed in the direction of arrow B by the rotation of the platen roller 3, and a paper discharge port (not shown). Is discharged in the direction of arrow C. A carriage 6 is provided in front of the platen roller 3 so as to be movable in the direction of arrow D along the axis of the platen roller 3.
[0016]
The carriage 6 is detachably mounted with a recording head 5 and an ink cartridge 7 containing ink supplied to the recording head 5. As shown in detail in FIG. 2, the connection portion between the recording head 5 and the ink cartridge 7 is supported by the cartridge mounting portion 6 a of the carriage 6 via the manifold member 17. The rear end portion passes through the vertical wall portion 6b of the cartridge mounting portion 6a and is connected to the ink supply hole 7a of the ink cartridge 7 through the joint member 19. The ink cartridge 7 is provided with a net-like filter member 21 together with the adapter 20 in the ink supply hole 7a. The upper and lower sides of the recording head 5 are covered with an upper cover 22 and a lower cover 23, respectively. The recording head 5 has a left end face in FIG. 2 as a nozzle face in which nozzle holes are opened. In this example, a recording head 5 having head portions for four colors of yellow, black, cyan, and magenta and an ink cartridge 7 for storing these inks are mounted on a carriage 6.
[0017]
A carriage shaft 8 is provided in parallel with the axis of the platen roller 3, and a carriage 6 is slidably fitted on the carriage shaft 8. Further, the engaging portion 6 c of the carriage 6 is guided by a guide rail 9 extending in parallel with the carriage shaft 8. As a result, the recording head 5 mounted on the carriage 6 can reciprocate by sliding along the axis of the platen roller 3. The carriage 6 is fixed to a part of a timing belt 11, and the timing belt 11 is wound around timing pulleys 12 and 13 to form a carriage mechanism CM. A CR motor 10 (carriage drive) is mounted on the one timing pulley 12. Motor) is connected. Therefore, when the CR motor 10 is driven to rotate, the carriage 6 reciprocates in the recording area for recording on the printing paper 4 via the carriage mechanism CM. Further, the carriage mechanism CM and the CR motor 10 constitute moving means for moving the carriage 6 between the recording area and a recovery area in which a recovery operation by a suction cap 41, a suction pump 42 and a wiper member 32, which will be described later, is performed. Has been. As the CR motor 10, a step motor or a DC motor is used.
[0018]
Further, a flushing area in which a waste ink receiving member 24 is disposed is on the left side of the recording area corresponding to the platen roller 3, and the non-ejection of the recording head 5 is on the right side of the recording area corresponding to the platen roller 3. Alternatively, a recovery area in which a purge mechanism RM for recovering a discharge failure is provided. Such a waste ink receiving member 24 is provided in order to eliminate clogging of the nozzle holes of the recording head 5 or to remove bubbles mixed in the ink in the nozzle holes of the recording head 5. This is because the ink is preliminarily ejected immediately before the recording operation by the recording head 5, and the purge mechanism RM is provided in the ink jet recording head 5. This is to cause a discharge failure due to dryness or the like, and to recover this to a good discharge state.
[0019]
The purge mechanism RM can move between a protruding position protruding into the moving path of the recording head 5 and a standby position retracted from the moving path of the recording head 5, and is in close contact with the nozzle surface of the recording head 5 at the protruding position. The suction cap 41 and the suction position for sucking ink in the recording head 5 through the suction cap 41 by generating a negative pressure when the nozzle face of the recording head 5 is covered with the suction cap 41 at the protruding position. A suction means 31 having a pump 42 is provided.
[0020]
A wiper member 32 that can move relative to the recording head 5 so as to wipe the nozzle surface of the recording head 5 on the recording area side adjacent to the suction means 31 does not perform recording on the opposite side. A storage cap device 33 is provided for covering the nozzle surface 5 and preventing the ink surface from evaporating to prevent the nozzle surface from drying.
[0021]
The wiper member 32, the suction cap 41, and the suction pump 42 are associated with driving means having a cam member 43 that is rotationally driven. The advancement / retraction of the wiper member 32, the advance / retreat of the suction cap 41, and the operation of the suction pump 42 are performed. It is configured to be controlled by the rotation of the common cam member 43.
[0022]
As shown in FIG. 3, the cam member 43 has a drive gear 46 provided integrally. When the carriage 6 is in the recovery area by the switching mechanism 121 described later, The cam member 43 is configured to detachably engage with a drive gear (not shown) that is rotationally driven by the LF motor 14 of the feed mechanism LM, and the cam member 43 is rotationally driven using the LF motor 14 as a driving means. Yes.
[0023]
In addition, the rear end portion (cam follower portion) of the wiper holder 34 that supports the wiper member 32 is movably engaged with the first cam groove 43a of the cam member 43, whereby the cam member 43 rotates. The wiper member 32 extends in a direction orthogonal to the moving path of the recording head 5 between a protruding position where the wiper member 32 protrudes into the moving path of the recording head 5 and a standby position retracted from the moving path of the recording head 5. The reciprocation is possible, and the nozzle surface of the recording head 5 is controlled to be wiped at the protruding position.
[0024]
The suction cap 41 is supported by a support portion 44a of the cap holder 44, and a cam follower portion 44b, which is a rear end portion of the cap holder 44, is formed on the same side of the cam member 43 as the first cam groove 43a. The second cam groove 43b is movably engaged, whereby the cam member 43 rotates, whereby the suction cap 41 protrudes into the movement path of the recording head 5, and the recording head 5 It can be reciprocated in a direction orthogonal to the movement path of the recording head 5 between the standby position retracted from the movement path, and is controlled so as to cover the nozzle surface of the recording head 5 at the protruding position. The support portion 44a of the cap holder 44 is movably supported by a guide member 45 provided on the frame member 51, and a spring member 47 interposed between the guide member 45 and the support portion 44a. The cap holder 44 (suction cap 41) is always urged in the protruding direction.
[0025]
In the suction pump 42, first and second piston members 53 and 54 are inserted into a cylindrical pump casing 52 attached and fixed to a frame member 51 so as to be independently movable. In the pump casing 52, a suction port 52a and a discharge port 52b are provided at regular intervals in the axial direction. The suction cap 41 is connected to the suction port 52a via a suction pipe 55, and the discharge port 52b. Are open to the atmosphere and open above a waste ink tank 58 containing an adsorbent 57 (see FIG. 1). Moreover, the one end part side of the pump casing 52 becomes the air release part 52c open | released by air | atmosphere. The piston member 53 is provided with a second piston member 54 on the other end side.
[0026]
The first and second piston members 53 and 54 are connected to one end portions of the first and second drive shaft members 61 and 62, respectively, and are driven by the drive shaft members 61 and 62. A pump chamber 52e is formed between the piston members 53 and 54.
[0027]
The first drive shaft member 61 is slidably fitted into the second drive shaft member 62, and the first and second engagement members 63, 64 at the other ends of the drive shaft members 61, 62 are inserted. However, it is movably engaged with the third and fourth cam grooves 43c and 43d of the cam member 43 on the side opposite to the cam grooves 43a and 43b.
[0028]
Accordingly, when the cam member 43 is rotationally driven at a constant timing, the capping of the suction cap 41, the suction of ink by the suction pump 42, and the wiping of the nozzle surface of the recording head 5 by the wiper member 32 are sequentially performed. The ink sucked by the suction pump 42 is discharged to the waste ink tank 58 through the suction pump 42 and is adsorbed by the adsorbent 57 in the waste ink tank 58.
[0029]
The cam member 43 controls the first and second piston members 53, 54, and the suction port 52 a from the standby state before the suction start until the suction cap 41 covers the nozzle surface of the recording head 5. Are operated to be opened to the atmosphere through the pump chamber 52e and the discharge port 52b, and two or more suction operations with different suction forces are performed to suck the ink of the recording head 5. Here, the suction port 52a is opened to the atmosphere from the standby state before the start of suction until the suction cap 41 covers the nozzle surface of the recording head 5. Even if the suction cap 41 is elastically deformed when the surface is covered, the air inside the suction cap 41 is not compressed. Therefore, it acts on the nozzle hole of the recording head 5 to break the so-called meniscus, and the bubbles in the recording head 5 This is so that there is no risk of intrusion. Further, the two or more suction operations having different suction forces are a first suction operation having a small suction force and a second suction operation having a suction force larger than that of the first suction operation and a longer suction time. The suction operation is performed when the suction operation is performed by the suction pump 42 in a state where ink is not contained in the recording head 5 and the ink passage thereof is filled with air. When a large negative pressure is applied through the suction cap 41 so that the ink of the recording head 5 is sucked at once, the ink cartridge 7 rapidly increases in a state where the ink is mixed with air into a large number of channels (ink passages) of the recording head 5. This is because the ink is bubbled and the ink in the recording head 5 contains bubbles.
[0030]
As shown in FIG. 1, the storage cap device 33 has a storage cap 71, and a casing 72 that supports the storage cap 71 slides and rotates on a guide rod 73 that extends parallel to the moving direction of the carriage 6. Is supported to be possible.
[0031]
The casing 72 has an engaging protrusion 72a protruding forward, and the engaging protrusion 72a engages with the carriage 6 when the carriage 6 moves to the recovery area side. It is designed to slide together. Therefore, when the carriage 6 moves from the recording area to the recovery area side, the carriage 6 engages with the engagement convex portion 72 a of the casing 72, so that the storage cap 71 slides following the movement of the carriage 6. (Right direction in FIG. 1). During this sliding movement, the casing 72 is rotated around the guide rod 73 by the action of an inclined cam means (not shown). As a result, the storage cap 71 rotates in a direction approaching the recording head 5, and the storage cap 71 Will contact the nozzle surface of the recording head 5 to perform capping. Thereafter, when the carriage 6 moves again in the direction of the recording area, the storage cap 71 moves away from the recording head 5 while moving toward the recording area. When the carriage 5 leaves the recovery area, the initial state is restored.
[0032]
Next, the control unit of the inkjet recording apparatus 1 according to the embodiment will be described with reference to the block diagram of FIG. This control unit is configured around a CPU 100 that is a known arithmetic processing unit.
[0033]
The CPU 100 is connected to a host computer 102 such as a personal computer via an interface 101, receives a print command from the host computer 102, and executes various printings according to the command.
[0034]
A typical functional configuration of the host computer 102 is a window system. Various applications (A), (B),... (N) are provided on the window system, and font drivers, CRT drivers, keyboard drivers, mouse drivers, printer drivers, and the like are incorporated. When printing using the inkjet recording apparatus 1 during execution of various applications, output data relating to an image suitable for the printing function of the inkjet recording apparatus 1 is created by the printer driver.
[0035]
An operation panel 103, ROM 104, and RAM 105 are connected to the CPU 100. The operation panel 103 sets various parameters such as paper size and displays them. The ROM 104 stores various programs necessary for controlling the inkjet recording apparatus 1. The RAM 105 temporarily stores print data transferred from the host computer 102 and various numerical values necessary for controlling the inkjet recording apparatus 1, and includes a buffer memory 105a.
[0036]
The CPU 100 drives and controls the LF motor 14, the CR motor 10, and the recording head 5 via an LF driving circuit 111, a CR driving circuit 112, and a head driving circuit 113.
[0037]
The LF motor 14 is configured to drive either the purge mechanism RM or the paper feed mechanism LM via the switching mechanism 121. That is, the purge mechanism RM is configured to be driven using the LF motor 14 as a paper feeding means, and the driving force is transmitted via the switching mechanism 121.
[0038]
The suction pump is constituted by the CPU 100, the switching mechanism 121 that switches the driving force from the LF motor 14 to the purge mechanism RM only during the purge operation, and the cam member 43 that is rotationally driven at a predetermined timing. The pump control means is configured to control the operation of 42 to perform the purge operation. With the pump control means, with the suction cap 41 covering the nozzle surface of the recording head 5, the pump chamber 52e is connected to the suction port 52a. The piston members 53 and 54 are relatively moved so as to be connected and enlarged, and the piston members 53 and 54 are relatively moved so that the pump chamber 52e is connected to the discharge port 52b and compressed. The piston members 53 are controlled until the suction cap 41 covers the nozzle surface of the recording head 5. 54, and performs a control to position so as to be in a state of being open to the atmosphere through the suction port 52a is the pump chamber 52e and the discharge port 52b.
[0039]
The CR motor 10 drives the carriage mechanism CM, and the switching mechanism 121 is switched by the movement of the carriage 6 of the carriage mechanism CM.
[0040]
The purge mechanism RM, the paper feed mechanism LM, and the carriage mechanism CM are provided with respective sensors, and detection signals from the sensors are input to the CPU 100 via the counter group 122. The purge mechanism RM has a purge HP sensor 131, and the purge HP sensor 131 notifies the purge position counter 122a of the counter group 122 when the suction pump 42 is at the origin position. This signal is used as a reference for the purge operation by the purge mechanism.
[0041]
The paper feed mechanism LM has a PE sensor 132. The PE sensor 132 generates a signal by the leading edge of the newly supplied printing paper 4, and notifies the LF position counter 122b of the counter group 122. This signal becomes the reference for the recording position control in the vertical direction.
[0042]
The carriage mechanism CM includes a CR position sensor 133. The CR position sensor 133 counts the drive pulses of the CR motor 10 to detect the position of the carriage, and notifies the CR position counter 122c of the counter group 122. This position information serves as a reference for the maintenance position control in the horizontal direction, and also serves as a reference for determining whether or not a new supply operation for the printing paper 4 and a discharge operation for the printed paper are possible.
[0043]
The operation of the inkjet recording apparatus 1 configured as described above will be described.
[0044]
First, in the inkjet recording apparatus 1, the recording head 5 is normally in a standby position in a recovery area covered with the storage cap 71. When the recording data is input, the recording operation by the recording head 5 is started.
[0045]
The printing paper 4 for recording is supplied between the platen roller 3 and the recording head 5, and the recording head 5 is moved from the standby position to the recording start position by the operation of the CR motor 10. At this time, the storage cap 71 is retracted. As a result, the recording head 5 is reciprocated in the recording area while ejecting ink based on the recording data, whereby printing is performed on the printing paper 4 based on the recording data.
[0046]
Then, when there is no recording data to be recorded in the recording data memory of the RAM 105 and recording is completed, the recording head 5 is moved from the recording end position to the standby position, covered with the advanced storage cap 71, and not used. Drying of the nozzle surface of the recording head 5 is prevented.
[0047]
Further, when the purge switch on the operation panel 103 is operated and a purge command is input according to the judgment of the user, the operation shifts to a purge mode for operating the purge mechanism RM, and the suction operation program is executed. That is, by driving the carriage mechanism CM by the CR motor 10, the recording head 5 is moved from the standby position to a purgeable position facing the suction cap 41. When the recording head 5 is in the standby position, the switching mechanism 121 has already switched the LF motor 14 to a state in which the driving force can be transmitted to the purge mechanism RM, so that the cam member 43 is driven by the driving force from the LF motor 14. Is rotated once, the suction cap 41 and the wiper member 32 are brought into contact with and separated from the recording head 5 at a predetermined purge position, and the suction pump 42 performs suction and discharge operations.
[0048]
Here, in the suction operation, the suction cap 41 is brought into close contact with the nozzle surface of the recording head 5, and the suction pump 42 sucks ink from the recording head 5. This includes a so-called idle suction operation in which ink is sucked from the suction cap 41 by the suction pump 42 away from the surface.
[0049]
The purge switch is operated when it is necessary to suck ink, such as when an ink discharge failure occurs, the ink cartridge is replaced, or maintenance is performed.
[0050]
Next, the purge operation in the ink jet recording apparatus 1 will be described with reference to FIGS. 6 to 12 and FIG.
[0051]
When a purge operation is performed on the inkjet recording apparatus 1, the CR motor 10 is driven by the CPU 100 via the CR drive circuit 112, and the recording head 5 is moved to a purgeable position facing the suction cap 41 as described above. Then, the operations of the suction cap 41, the suction pump 42, and the like are controlled by the control of the cam member 43, thereby performing a series of purge operations for recovering a good ink discharge state.
[0052]
First, in the standby state before the rotation of the cam member 43, as shown in FIG. 6, the first piston member 53 of the suction pump 42 is positioned closer to one end of the pump casing than the suction port 52a, and the second The piston member 54 is located on the other end side of the pump casing with respect to the discharge port 52b, thereby allowing the suction port 52a and the discharge port 52b to communicate with each other via the pump chamber 52e therebetween. The suction cap 41 is at a standby position away from the nozzle surface of the recording head 5.
[0053]
Then, when the cam member 43 is rotationally driven, the suction cap 41 is gradually advanced from the standby position toward the movement path side of the recording head 5 (see the vicinity of P1 in FIG. 13), and the suction cap 41 is the nozzle of the recording head 5. Capping to cover the surface will be performed.
[0054]
Until the capping is completed, the first and second piston members 53 and 54 do not move and remain in the standby state described above, and the suction port 52a is opened to the atmosphere through the pump chamber 52e and the discharge port 52b. Has been. Therefore, when capping by the suction cap 41 is performed, the inside of the suction port 52a, the suction tube 55, and the suction cap 41 is in communication with each other through the pump chamber 52e and the discharge port 52b of the pump casing 52. Since they are released to the atmosphere through the pump chamber 52e and the discharge port 52b, even when the suction cap 41 covers the nozzle surface of the recording head 5, the air inside the suction cap 41 is elastically deformed. There is no possibility that the so-called meniscus is broken by acting on the nozzle holes of the recording head 5 without being compressed.
[0055]
Then, after the suction cap 41 completely covers the nozzle surface of the recording head 5 and comes into close contact, the first and second piston members 53 and 54 start moving toward the other end side while maintaining the distance therebetween. (Refer to the vicinity of P2 in FIGS. 7 and 13), the first piston member 53 closes the suction port 52a. At this time, since the pump chamber 52a is not compressed, air does not act on the nozzle hole and break the meniscus as described above. Thereafter, the second piston member 54 moves forward to the side edge position of the discharge port 52b, and the first piston member 53 blocks the suction port 52a from communicating with the discharge port 52b through the pump chamber 52e. As shown in FIG. 8, it continues until the pump chamber 52e becomes the minimum volume (see P3 in FIG. 13).
[0056]
Then, the first and second piston members 53, 54 move together to one end side while keeping the volume of the pump chamber 52e to a minimum, and as shown in FIG. 9, the pump chamber 52e with the minimum volume is moved. Is communicated with the suction port 52a (see the vicinity of P4 in FIG. 13). Then, as shown in FIG. 10, the first piston member 53 remains stationary and the second piston member 54 is moved in the direction of expanding the pump chamber 52e between the first piston member 53 (FIG. 13). (Refer to the vicinity of P5). At this time, since the pump chamber 52e is connected to the suction port 52a, the first suction operation is started. By this first suction operation, suction is performed with a small negative pressure, and when air is contained in the recording head 5, ink is sucked together with the air, and the ink in the ink cartridge 7 passes through the filter 21. It passes slowly and fills the manifold member 17. In this way, when ink passes through the filter 21, suction is performed with a small negative pressure, so that ink is prevented from foaming, and bubbles are prevented from entering the recording head 5.
[0057]
Then, for a while, the first and second piston members 53 and 54 maintain the volume of the pump chamber 52e constant, and after the first suction operation is continued, as shown in FIG. The first and second piston members 53 and 54 are moved in a direction to close the suction port 52a while maintaining the volume of the pump chamber 52e (see the vicinity of P6 in FIG. 13), and the first suction operation is completed. At this time, the second piston member 54 closes the discharge port 52b.
[0058]
Thereafter, the state is maintained for a while, the first piston member 53 is moved in a direction to open the suction port 52a in a state where the discharge port 52b is closed by the second piston member 54, and the pump chamber 52e is moved. The negative pressure is gradually increased to gradually increase, and finally the suction port 52a is opened as shown in FIG. 12 (see the vicinity of P7 in FIG. 13), and this state is maintained for a while. Therefore, until the capping by the suction cap 41 is released, the second suction operation having a suction force larger than that of the first suction operation and having a longer suction time is performed. By this second suction operation, the ink in the recording head 5 is sucked at once and recovered to a good ejection state.
[0059]
When the suction cap 41 is gradually retracted and separated from the recording head 5, since the pump chamber 52 e is in a negative pressure state, ink is not sucked from the recording head 5, and residual ink in the suction cap 41 is not collected. A so-called idle suction operation is started.
[0060]
Then, the first piston member 53 is moved while the suction port 52a is opened, as shown in FIG. 6, until the second piston member 54 opens the discharge port 52b (see the vicinity of P8 in FIG. 13). ), The suction operation is performed while further expanding the pump chamber 52e.
[0061]
Then, as shown in FIG. 7, the first and second piston members 53, 54 move together while maintaining the distance therebetween, opening the discharge port 52b and closing the suction port 52a (see FIG. 13). P9), the idle suction operation is terminated.
[0062]
Then, as shown in FIG. 8, the second piston member 54 advances to the side edge position of the discharge port 52b and stops, while the first piston member 53 continues the movement and compresses the pump chamber 52e. Then, the discharging operation is positively performed (see P10 in FIG. 13). As a result, the ink in the pump chamber 52e is discharged to the waste ink tank 58. After the discharging operation, both piston members 53 and 54 are returned to the same state as the initial state (standby state) shown in FIG.
[0063]
The above embodiment is applied to the case where the filter member 21 is provided only in the ink supply hole 7a of the ink cartridge 7. However, the recording head (manifold) at the connection portion between the ink cartridge 7 and the recording head 5 is used. ) Side may also be provided with a filter member 21A (see FIG. 2). In such a case, the suction operation performed by the suction pump 42 is the first and second suction operations with a small suction force, By adopting the third suction operation having a larger suction force and a longer suction time than the first and second suction operations, the same effects as the above-described embodiment can be obtained.
[0064]
That is, the first suction operation by the suction pump 42 is performed with the suction force necessary for the ink to pass through the first filter member 21, and the second suction operation is performed by the ink further passing through the next filter member 21A. The third suction is performed by the suction force necessary to pass through and fill the ink passage in the recording head 5, and thereafter, the suction force is larger and the suction time is longer than those of the first and second suction operations. Even if the operation is performed, the ink can be prevented from foaming.
[0065]
【The invention's effect】
The present invention is implemented in the form as described above, and has the following effects.
[0066]
According to the first aspect of the present invention, as described above, the pump control means is configured so that the pump chamber connects the pump chamber to the suction port and expands with the suction cap covering the nozzle surface of the recording head. A second control for relatively moving the piston members so as to compress and connect the pump chamber to the discharge port, and the suction cap covers the nozzle surface of the recording head. Until the first and second piston members are positioned with an interval between the suction port and the discharge port, and both the piston members are opened to the atmosphere through the pump chamber and the discharge port. A pump between the first and second piston members after the third control is performed and the suction cap covers the nozzle surface of the recording head. The first piston member is moved to a position where the first piston member closes the suction port with respect to the pump chamber while the volume of the first piston member is closed, and then both the piston members are moved to the pump chamber. Are moved relative to each other so as to have a minimum volume when connected to the discharge port. In addition to being able to perform ink suction / discharge operations from the recording head, the suction cap is connected to the recording head. Until the nozzle surface is covered, the pump control means positions the first and second piston members at an interval across the suction port and the discharge port, and the suction port passes through the pump chamber and the discharge port. When the suction cap covers the nozzle surface of the recording head, the air inside the suction cap is not compressed even if it is elastically deformed. Break called meniscus acts on the nozzle hole of the recording head I, there is no possibility to penetrate the bubbles in the recording head. Then, after the suction cap covers the nozzle surface, the first piston member closes the suction port with respect to the pump chamber while maintaining the volume of the pump chamber between the first and second piston members. Since the first and second piston members are moved to the positions, the pump chamber is not compressed, so that there is no possibility that air acts on the nozzle hole and breaks the meniscus. And it will be in the state which can be attracted | sucked by moving the both piston members relatively so that the said pump chamber may become the minimum volume in the state connected to the said discharge port. Since suction is performed with a small negative pressure, it is possible to suppress bubbling of ink. Thus, until the suction cap covers the nozzle surface of the recording head, both piston members are positioned so that the suction port is opened to the atmosphere through the pump chamber and the discharge port, and the suction cap is moved to the recording head. When covering the nozzle surface, even if the suction cap is elastically deformed, the air inside the suction cap is not compressed, so that it acts on the nozzle hole to break the so-called meniscus and prevent bubbles from entering the recording head. be able to.
[0067]
According to the second aspect of the present invention, the first piston member is placed closer to one end of the pump casing than the suction port and the second piston member is pumped from the discharge port until the suction cap covers the nozzle surface of the recording head. Since it is positioned on the other end side of the casing, when the suction cap covers the nozzle surface of the recording head, the air inside the suction cap is released to the atmosphere through the pump chamber and the discharge port with simple control. can do.
[0068]
In the invention of claim 3, since both the piston members are moved to the suction port side while the pump chamber is in the minimum volume state, and thereafter the first control is performed, the suction operation can be performed. By performing suction with a small negative pressure, it is possible to suppress ink from foaming and to prevent bubbles from entering the recording head.
The invention of claim 4 can be stopped in the initial state (standby state) by returning both piston members to the state in which the third control is performed after the discharging operation.
[Brief description of the drawings]
FIG. 1 is a perspective view showing a schematic configuration of an ink jet recording apparatus according to the present invention.
FIG. 2 is an explanatory diagram of a connection portion between a recording head and an ink cartridge.
FIG. 3 is a cross-sectional view showing a relationship among a wiper member, a suction cap, a suction pump, and a cam member according to the present invention.
4 is a cross-sectional view taken along line III-III in FIG.
FIG. 5 is a block diagram of a control unit of the ink jet recording apparatus.
FIG. 6 is an operation explanatory diagram of a suction pump.
FIG. 7 is an operation explanatory diagram of a suction pump.
FIG. 8 is an operation explanatory diagram of a suction pump.
FIG. 9 is an operation explanatory diagram of a suction pump.
FIG. 10 is an operation explanatory diagram of a suction pump.
FIG. 11 is an operation explanatory diagram of a suction pump.
FIG. 12 is an operation explanatory diagram of the suction pump.
FIG. 13 is an explanatory diagram of the rotation angle of the cam member and the operation of the suction cap, the wiper member, and the suction pump (first and second piston members).
[Explanation of symbols]
1 Inkjet recording device
5 Recording head
14 LF motor
31 Suction means
32 Wiper members
41 Suction cap
42 Suction pump
43 Cam member
52 Pump casing
52a Suction port
52b outlet
52e Pump room
53 First piston member
54 Second piston member
100 CPU

Claims (4)

A recording head that performs a recording operation by discharging ink onto a recording medium, a suction cap that can be contacted with and separated from the nozzle surface so as to cover the nozzle surface of the recording head so as to be openable and closable, In an ink jet recording apparatus comprising: a suction pump for sucking ink from the pump; and a pump control means for controlling the operation of the suction pump in conjunction with the contact and separation operation of the suction cap.
The suction pump includes a cylindrical pump casing having a suction port connected to the suction cap and a discharge port for discharging the sucked ink at an interval in the axial direction, and slides inside the pump casing. First and second piston members fitted to each other, the suction port and the discharge port are provided in this order from the one end portion side of the pump casing, and the first piston is disposed on the one end portion side of the pump casing. A member is disposed and a variable volume pump chamber is formed between the first and second piston members,
The pump control means includes a first control for moving the piston members relative to each other so as to expand and connect the pump chamber to the suction port in a state where the suction cap covers the nozzle surface of the recording head; A second control for moving the piston members relative to each other to connect and compress the pump chamber to the discharge port; and the first piston member and the second piston until the suction cap covers the nozzle surface of the recording head. A piston member is positioned at an interval across the suction port and the discharge port, and the third control is configured to open the suction port to the atmosphere through the pump chamber and the discharge port,
After the third control is performed and the suction cap covers the nozzle surface of the recording head, the first piston member holds the suction chamber while maintaining the volume of the pump chamber between the first and second piston members. Moving the first and second piston members to a position where the mouth is closed relative to the pump chamber;
Then, the two piston members are moved relative to each other so as to have a minimum volume in a state where the pump chamber is connected to the discharge port. The pump control means positions the first piston member closer to one end of the pump casing than the suction port until the suction cap covers the nozzle surface of the recording head, and moves the second piston member to the discharge port. 2. The ink jet recording apparatus according to claim 1, wherein the ink jet recording apparatus is positioned on the other end side of the pump casing.   The said pump control means moves the said both piston members to the said suction port side with the said pump chamber in the state of the minimum volume, Then, the said 1st control is performed. Inkjet recording apparatus. The pump control means performs a series of operations including the third control, the second control, the first control, and the second control in this order, and after performing the series of operations, the third control The ink jet recording apparatus according to claim 1, wherein the ink jet recording apparatus stops in a state where control is performed.

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