JP2015186886A - Ink jet recorder - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ink jet recorder capable of keeping a meniscus in a nozzle in a proper state, and properly recording an image on a sheet.SOLUTION: An ink jet recorder executes idly discharge processing S15 for moving a carriage to a position where a recording head faces a cap, and idly discharging an ink to the recording head, during a plurality of single actions for recording an image in an area with the predetermined line-feed width of a sheet (S13:No, and S14:Yes); an idly suction processing S17 for sucking the ink in the cap by a pump, while a driving state switching portion is in a second driving state; and reversing processing S18 for reversing a motor only by the total rotation amount of the motor rotated in the idly suction processing.

Description

  The present invention relates to an ink jet recording apparatus in which a transport unit and a maintenance unit are driven by a single motor.

  Conventionally, a conveyance unit that conveys a sheet, a recording unit that records an image on a sheet by discharging ink from nozzles, a maintenance unit that maintains nozzles, a motor that drives the conveyance unit and the maintenance unit, There is known an ink jet recording apparatus that includes a switching unit that switches whether or not to transmit a driving force to a maintenance unit. For example, Patent Document 1 discloses an ink jet recording apparatus configured to transmit the driving force of a motor to a maintenance unit by moving the recording unit to a position facing the maintenance unit. On the other hand, the driving force of the motor is always transmitted to the transport unit.

JP2013-208772A

  In the ink jet recording apparatus configured as described above, for example, in order to maintain the ink discharge performance of the nozzles, it is conceivable that ink is discharged from the nozzles to the cap of the maintenance unit during image recording. However, when the maintenance unit is driven in order to discharge the ink ejected in the cap, the sheet is conveyed by the conveyance unit. As a result, the sheet is discharged by a series of operations of the maintenance unit during image recording, and image recording on the sheet may not be completed.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an ink jet recording apparatus capable of appropriately recording an image on a sheet while maintaining ink ejection performance.

  (1) An inkjet recording apparatus according to the present invention is mounted on a conveyance unit that conveys a sheet in a conveyance direction, a carriage that moves in a main scanning direction that intersects the conveyance direction, and ink from a nozzle. A recording head for discharging, a cap facing the recording head at a position deviating from one end side in the main scanning direction from a passage region of the sheet conveyed by the conveying unit, and a pump for sucking ink in the cap. A maintenance unit, a motor for driving the conveyance unit and the maintenance unit, a first driving state in which the driving force of the motor is not transmitted to the maintenance unit, and a second driving state in which the driving force is transmitted to the maintenance unit can be switched. A drive state switching unit and a control unit are provided. The control unit executes a recording process including a plurality of unit operations for causing the sheet to be conveyed to the conveyance unit by a predetermined line feed width in the conveyance direction and ejecting ink to the recording head with respect to the sheet. Between the plurality of unit operations, the recording head moves the carriage to a position facing the cap, and the recording head performs idle discharge processing, and the driving state switching unit includes the second driving state switching unit. In the driven state, an empty suction process for sucking ink in the cap by the pump and an inversion process for reversing the motor by the total rotation amount of the motor rotated in the empty suction process are executed.

  According to the above configuration, the sheet conveyed by driving the motor in the idle suction process can be returned to the original position by the reversing process. Thereby, even if the idle ejection process and the idle suction process are executed during image recording, the positional deviation of the sheet can be suppressed. As a result, the meniscus in the nozzle can be maintained in an appropriate state, and an image can be appropriately recorded on the sheet.

  (2) Preferably, the recording head includes a first nozzle that ejects a first color ink and a second nozzle that ejects a second color ink different from the first color. The maintenance unit is configured to remove ink in the cap by reversing the motor, a first cap that is the cap that can face the first nozzle, a second cap that is the cap that can face the second nozzle, and the motor. The pump for suction, the first communication state for communicating the pump and the first cap, and the second communication state for communicating the pump and the second cap can be switched alternately by forward rotation of the motor. A communication state switching unit. The conveyance unit conveys the sheet in the conveyance direction by forward rotation of the motor, and conveys the sheet in the direction opposite to the conveyance direction by reverse rotation of the motor. In the idle suction process, the control unit includes a first switching process for switching the communication state switching unit to the first communication state, a first suction process for causing the pump to suck ink from the first cap, and the communication. A second switching process for switching the state switching unit to the second communication state and a second suction process for causing the pump to suck ink from the second cap are executed. The total rotation amount corresponds to the sum of the forward rotation amount of the motor in the first switching process and the second switching process and the reverse rotation amount of the motor in the first suction process and the second suction process. To do.

  As described above, the switching process for rotating the motor in the forward direction and the suction process for rotating the motor in the reverse direction can be alternately performed, so that the sheet can be prevented from moving to one side during the idle suction process. . As a result, the positional deviation of the sheet before and after the idle suction process and the reversal process is reduced, so that deterioration in image recording quality can be more effectively suppressed.

  (3) Preferably, the control unit repeats the cycle of the first switching process, the first suction process, the second switching process, and the second suction process a plurality of times in the idle suction process.

  (4) Preferably, the control unit switches the communication state switching by alternately repeating forward rotation and reverse rotation of the motor in the first switching process in which the forward rotation amount of the motor is larger than that in the second switching process. The unit is switched to the first communication state.

  If the motor is continuously rotated in one direction, the sheet may pass through the conveyance unit. Therefore, as in each of the above-described configurations, it is desirable to repeat the cycle of the switching process and the suction process a plurality of times, or alternately repeat the forward rotation and the reverse rotation of the motor in the switching process.

  (5) Preferably, during the recording process, the control unit performs the idle ejection process in response to a lapse of a threshold time and completion of one of the plurality of unit operations.

  As in the above configuration, by periodically performing the idle ejection process, it is possible to suppress a decrease in image recording quality.

  (6) Preferably, the control unit performs the idle suction process and the inversion process in response to the ink ejection amount in the idle ejection process reaching a threshold amount.

  According to the above configuration, it is possible to reduce the number of executions of the idle suction process and the reversal process, and thus it is possible to more effectively suppress the deterioration of the image recording quality.

  According to the present invention, by reversing the motor by the total rotation amount of the motor in the idle suction process, the sheet can be positioned at the same position before and after the idle suction process is performed. It is possible to obtain an ink jet recording apparatus that can maintain an image and appropriately record an image on a sheet.

FIG. 1 is an external perspective view of the multifunction machine 10. FIG. 2 is a longitudinal sectional view schematically showing the internal structure of the printer unit 11. 3A is a plan view of the carriage 23 and the guide rails 43 and 44, and FIG. 3B is a perspective view showing the internal structure of the printer unit 11. FIG. 4A and 4B are cross-sectional views of the maintenance mechanism 70, where FIG. 4A shows a state in which the cap 71 is arranged at the uncapped position, and FIG. 4B shows a state in which the cap 71 is arranged at the cap position. FIG. 5 is a schematic diagram of the maintenance mechanism 70. 6A and 6B are schematic views of the port switching mechanism 90 as viewed from the bottom, where FIG. 6A shows a Bk suction state, FIG. 6B shows a Co suction state, and FIG. 6C shows an unlock state. 7A and 7B are perspective views of the switching mechanism 170, in which FIG. 7A shows a state where the switching lever 176 is disposed at the first position, FIG. 7B shows a state where the switching lever 176 is disposed at the second position, and FIG. ) Shows a state in which the switching lever 176 is arranged at the third position. FIG. 8 is a block diagram of the printer unit 11. FIG. 9 is a flowchart of the image recording process. FIG. 10 is a flowchart of the idle suction process.

  Hereinafter, embodiments of the present invention will be described. The embodiment described below is merely an example of the present invention, and it is needless to say that the embodiment of the present invention can be changed as appropriate without departing from the gist of the present invention. Further, in the following description, the advance from the starting point of the arrow to the ending point is expressed as the direction, and the traffic on the line connecting the starting point and the ending point of the arrow is expressed as the direction. Further, the vertical direction 7 is defined with reference to the state where the multifunction machine 10 is installed (the state shown in FIG. 1), and the front / rear direction 8 is defined with the side where the opening 13 is provided as the front side (front). A left-right direction 9 is defined when the multifunction machine 10 is viewed from the front side (front side).

[Overall configuration of MFP 10]
As shown in FIG. 1, the multifunction machine 10 is formed in a substantially rectangular parallelepiped. The multifunction device 10 includes a printer unit 11 that records an image on a sheet 12 (see FIG. 2) by an inkjet recording method, a display unit 14, and an operation unit 17 at the bottom. As shown in FIG. 2, the printer unit 11 includes a feeding unit 15, a feeding tray 20, a discharge tray 21, a transport roller unit 54, a recording unit 24, a discharge roller unit 55, and a platen 42. It has. The multifunction machine 10 has various functions such as a facsimile function and a print function. The multifunction machine 10 is an example of an ink jet recording apparatus. Further, the transport roller unit 54 and the discharge roller unit 55 constitute an example of a transport unit.

[Feed tray 20, discharge tray 21]
As shown in FIG. 1, the feeding tray 20 is inserted and removed by the user in the front-rear direction 8 through an opening 13 formed in the front surface of the printer unit 11. The feeding tray 20 can support a plurality of stacked sheets 12. The discharge tray 21 is disposed on the upper side of the feeding tray 20. The discharge tray 21 supports the paper 12 discharged by the discharge roller unit 55 through the opening 13 formed on the front surface.

[Feeding unit 15]
As shown in FIG. 2, the feeding unit 15 includes a feeding roller 25, a feeding arm 26, and a shaft 27. The feeding roller 25 is rotatably supported on the leading end side of the feeding arm 26. The feed roller 25 rotates (hereinafter referred to as “forward rotation”) in a direction in which the paper 12 is transported in the first transport direction 16A by reverse rotation of the transport motor 102 (an example of a motor, see FIG. 8). The feeding arm 26 is rotatably supported on a shaft 27 supported by the frame of the printer unit 11. The feeding arm 26 is urged to rotate toward the feeding tray 20 by its own weight or an elastic force by a spring or the like.

[Conveyance path 65]
As shown in FIG. 2, the conveyance path 65 indicates a space formed by an outer guide member 18 and an inner guide member 19 that are partially opposed to each other at a predetermined interval inside the printer unit 11. The conveyance path 65 is a path extending from the rear end portion of the feeding tray 20 to the rear side of the printer unit 11. The conveyance path 65 is a path that makes a U-turn while extending upward from below on the rear side of the printer unit 11 and reaches the discharge tray 21 through the recording unit 24. In the transport path 65, the transport direction of the paper 12 from the feed tray 20 side to the discharge tray 21 side is defined as a first transport direction 16A, and the transport of the paper 12 from the discharge tray 21 side to the feed tray 20 side is defined. The transport direction is defined as the second transport direction 16B. That is, the first transport direction 16A and the second transport direction 16B are opposite to each other, as indicated by a dashed line arrow in FIG.

[Conveying roller unit 54]
As shown in FIG. 2, the transport roller unit 54 is disposed upstream of the recording unit 24 in the first transport direction 16A. The conveyance roller unit 54 includes a conveyance roller 60 and a pinch roller 61 that face each other. The conveyance roller 60 is driven by the conveyance motor 102. The pinch roller 61 is rotated along with the rotation of the conveyance roller 60. The sheet 12 is nipped by a conveyance roller 60 and a pinch roller 61 that are normally rotated by the normal rotation of the conveyance motor 102 and conveyed in the first conveyance direction 16A. In addition, the sheet 12 is nipped by the conveyance roller 60 and the pinch roller 61 that are rotated in reverse by the reverse rotation of the conveyance motor 102 and is conveyed in the second conveyance direction 16B.

[Discharge roller section 55]
As shown in FIG. 2, the discharge roller unit 55 is disposed downstream of the recording unit 24 in the first transport direction 16 </ b> A. The discharge roller unit 55 includes a discharge roller 62 and a spur 63 that face each other. The discharge roller 62 is driven by the transport motor 102. The spur 63 is rotated along with the rotation of the discharge roller 62. The sheet 12 is nipped between the discharge roller 62 and the spur 63 that are rotated forward by the normal rotation of the conveyance motor 102 and is conveyed in the first conveyance direction 16A. Further, the paper 12 is sandwiched between the discharge roller 62 and the spur 63 that are rotated in reverse by the reverse rotation of the transport motor 102 and is transported in the second transport direction 16B.

[Platen 42]
As shown in FIGS. 2 and 3A, the platen 42 is disposed between the transport roller portion 54 and the discharge roller portion 55 in the first transport direction 16A. The platen 42 is disposed so as to face the recording unit 24 in the vertical direction 7 and supports the paper 12 conveyed by the conveyance roller unit 54 from below.

[Recording unit 24]
As shown in FIG. 2, the recording unit 24 is disposed between the conveyance roller unit 54 and the discharge roller unit 55 in the first conveyance direction 16 </ b> A. The recording unit 24 is disposed so as to face the platen 42 in the vertical direction 7. The recording unit 24 includes a carriage 23, a recording head 39, and an encoder sensor 38A. Further, as shown in FIG. 3A, an ink tube 32 and a flexible flat cable 33 are extended from the carriage 23. The ink tube 32 supplies ink of the ink cartridge mounted on the cartridge mounting portion to the recording head 39. The flexible flat cable 33 connects the control board on which the control unit 130 is mounted and the recording head 39.

  As shown in FIG. 3A, the carriage 23 is supported by guide rails 43 and 44 that extend in the left-right direction 9 at positions separated in the front-rear direction 8. The guide rails 43 and 44 are supported by the frame of the printer unit 11 as shown in FIG. The carriage 23 is connected to a known belt mechanism provided on the guide rail 44. This belt mechanism is driven by a carriage motor 103 (see FIG. 8). That is, the carriage 23 reciprocates in the main scanning direction along the left-right direction 9 via the belt mechanism that moves circumferentially by driving the carriage motor 103.

  The recording head 39 is mounted on the carriage 23 as shown in FIG. A plurality of nozzles 40 are formed on the lower surface of the recording head 39. The recording head 39 ejects ink from the nozzle 40 as fine ink droplets. In the process of moving the carriage 23, the recording head 39 ejects ink droplets toward the paper 12 supported by the platen 42. As a result, an image is recorded on the paper 12.

  Further, as shown in FIG. 3, the guide rail 44 is provided with a strip-shaped encoder strip 38 </ b> B extending in the left-right direction 9. The encoder sensor 38A is mounted on the carriage 23. The encoder sensor 38 </ b> A and the encoder strip 38 </ b> B are provided at positions facing each other in the vertical direction 7. In the process of moving the carriage 23, the encoder sensor 38 </ b> A reads the encoder strip 38 </ b> B to generate a pulse signal, and outputs the generated pulse signal to the control unit 130. The encoder sensor 38A and the encoder strip 38B constitute the carriage sensor 38 shown in FIG.

[Display unit 14]
The display unit 14 includes a display screen that displays information to be notified to the user as a message or an animation. Although the specific configuration of the display unit 14 is not particularly limited, for example, a liquid crystal display (abbreviation of Liquid Crystal Display), an organic EL display (abbreviation of Organic Electro-Luminescence Display), or the like can be employed.

[Operation unit 17]
The operation unit 17 is an input interface that receives an instruction input to the multifunction machine 10 from a user. The specific configuration of the operation unit 17 is not particularly limited. For example, the operation unit 17 may include a plurality of push buttons, or may include a touch sensor superimposed on the display screen of the display unit 14 as illustrated in FIG. You may do it.

[Maintenance mechanism 70]
The multifunction machine 10 further includes a maintenance mechanism 70 (an example of a maintenance unit) shown in FIGS. 4 and 5. As shown in FIG. 3A, the maintenance mechanism 70 is located on the right side from a range (hereinafter, referred to as “passing area”) through which the paper 12 conveyed by the conveyance roller unit 54 and the discharge roller unit 55 passes. It is placed at a position that is off. The passing area is an area where the recording head 39 and the paper 12 on the platen 42 can face each other.

  The maintenance mechanism 70 includes a cap 71, a lift-up mechanism 73, a contact lever 76, a pump 77 (see FIGS. 5 and 8), and a port switching mechanism 90 (an example of a communication state switching unit). . The maintenance mechanism 70 performs a purge operation for sucking ink and air in the nozzles 40 and foreign matters adhering to the nozzle surface (hereinafter collectively referred to as “ink etc.”), and the recording head 39 to the cap 71. An empty suction operation (see FIG. 10) for sucking ink or the like that has been discharged in an empty manner is executed. The ink and the like removed by suction by the maintenance mechanism 70 is stored in the drainage tank 110 (see FIGS. 3B and 5).

  The cap 71 is made of rubber. The cap 71 is provided to face the carriage 23 located on the right side of the passage area. The cap 71 faces the recording head 39 of the carriage 23 that is in contact with the switching lever 176 (described later) at the second position and the third position shown in FIG. The cap 71 is configured to be movable between a cap position that covers the nozzle surface (“the surface on which the nozzle 40 of the recording head 39 is formed”) and an uncap position that is separated from the nozzle surface.

  The inside of the cap 71 is partitioned into a Bk cap (an example of a first cap) and a Co cap (an example of a second cap). The Bk cap covers a region where a nozzle (an example of a first nozzle) that discharges black ink is formed, and forms a sealed space between the region. The Co cap covers a region where a nozzle (an example of a second nozzle) that discharges color ink is formed, and forms a sealed space between the region. The Bk cap is connected to a Bk port 95 described later, and the Co cap is connected to a Co port 96 described later.

  The pump 77 is, for example, a rotary tube pump. The pump 77 forms a flow of fluid (such as ink or air) from the suction port 77A to the discharge port 77B shown in FIG. On the other hand, the forward driving force of the transport motor 102 is not transmitted to the pump 77. A port switching mechanism 90 is connected to the distal end of the tube 91A extending from the suction port 77A. A cap 71 is connected to the distal end of the tube 91 </ b> B extended from the port switching mechanism 90. That is, the cap 71 and the suction port 77A communicate with each other through the tubes 91A and 91B and the port switching mechanism 90. On the other hand, the drainage tank 110 is attached to the tip of the tube 91C extended from the discharge port 77B.

  The lift-up mechanism 73 includes a link 74 as shown in FIG. By rotating the link 74 in conjunction with the movement of the carriage 23, the holder 75 is moved between the position shown in FIG. 4A and the position shown in FIG. The holder 75 holds a cap 71 and a contact lever 76 protruding vertically upward. The contact lever 76 extends to the movement range of the carriage 23.

  The carriage 23 that moves to the right presses the contact lever 76 and moves it to the right. The holder 75 that holds the contact lever 76 rises in conjunction with the rightward movement of the contact lever 76 and moves the cap 71 to the cap position. On the other hand, the carriage 23 moved to the left moves away from the contact lever 76. The contact lever 76 separated from the carriage 23 moves to the left. Then, the holder 75 descends in conjunction with the leftward movement of the contact lever 76, and moves the cap 71 to the uncapped position.

[Port switching mechanism 90]
The port switching mechanism 90 switches the communication state between the cap 71 and the pump 77. As shown in FIG. 6, the port switching mechanism 90 includes a cylinder 99 having a bottomed cylindrical body and a columnar rotating body 92 disposed inside the cylinder 99. An intake port 93, a Bk port 95, a Co port 96, and atmospheric ports 97 and 98 are formed in the cylinder 99. Specifically, the port switching mechanism 90 includes a Bk suction state (an example of a first communication state) shown in FIG. 6A and a Co suction state (a second communication state) shown in FIG. It is possible to switch to the unlocked state shown in FIG.

  The intake port 93 is formed on the bottom wall of the cylinder 99. The other four ports 95 to 98 are formed on the side wall of the cylinder 99 at predetermined intervals in the circumferential direction. The Bk port 95 communicates with the internal space of the Bk cap via the tube 91B. The Co port 96 communicates with the internal space of the Co cap via the tube 91B. Atmospheric ports 97 and 98 are open to the atmosphere. One end of the tube 91 </ b> A is connected to the intake port 93, and the other end is connected to the suction port 77 </ b> A of the pump 77.

  The rotating body 92 rotates inside the cylinder 99 by the forward rotation of the transport motor 102 (in this embodiment, rotates counterclockwise in FIG. 6). As the rotating body 92 rotates inside the cylinder 99, the communication states of the ports 93 and 95 to 98 formed in the cylinder 99 are alternately changed. On the other hand, the reverse driving force of the conveyance motor 102 is not transmitted to the rotating body 92. The Bk suction state shown in FIG. 6A is a state where the intake port 93 communicates with the Bk port 95. The Co suction state shown in FIG. 6B is a state where the intake port 93 communicates with the Co port 96. The unlocked state shown in FIG. 6C is a state where the intake port 93 is not in communication with any of the Bk port 95, the Co port 96, and the atmospheric ports 97 and 98.

  Further, the maintenance mechanism 70 includes a lock portion that fixes the carriage 23 at a position facing the cap 71. The lock portion has a lock pin that can move in the vertical direction 7 as the rotating body 92 rotates. The lock pin enters a recess provided in the carriage 23 to restrict the movement of the carriage 23 in the left-right direction 9 (ie, the raised position), and is separated from the carriage 23 in the left-right direction of the carriage 23. 9 is configured to be movable to an unlock position that permits movement to the position 9 (that is, a lowered position).

  When the pump 77 is driven in the Bk suction state shown in FIG. 6A, the ink or the like in the Bk cap is discharged to the drainage tank 110 through the tubes 91 </ b> A to 91 </ b> C, the port switching mechanism 90, and the pump 77. Further, when the pump 77 is driven in the Co suction state shown in FIG. 6B, the ink and the like in the Co cap are discharged to the drainage tank 110 through the tubes 91 </ b> A to 91 </ b> C, the port switching mechanism 90, and the pump 77. Furthermore, the unlocked state shown in FIG. 6C is a state in which the above-described lock pin is disposed at the unlocked position.

  In the present embodiment, the following rotation angle α and rotation angle γ are larger than the rotation angle β and the rotation angle θ. Here, the rotation angle α can be rephrased as the rotation angle of the rotating body 92 (“forward rotation amount of the transport motor 102”) required for switching the port switching mechanism 90 from the unlocked state to the Bk suction state. .) The rotation angle γ indicates the rotation angle of the rotating body 92 necessary for switching the port switching mechanism 90 from the Co suction state to the Bk suction state. The rotation angle β indicates the rotation angle of the rotating body 92 necessary for switching the port switching mechanism 90 from the Bk suction state to the Co suction state. The rotation angle θ indicates the rotation angle of the rotating body 92 necessary for switching the port switching mechanism 90 from the Co suction state to the unlocked state.

[Driving force transmission mechanism 104]
A driving force transmission mechanism 104 shown in FIG. 8 transmits the driving force of the conveyance motor 102 to the feeding roller 25, the conveyance roller 60, the discharge roller 62, and the maintenance mechanism 70. The driving force transmission mechanism 104 is configured by combining all or part of a gear, a pulley, an endless annular belt, a planetary gear mechanism (pendulum gear mechanism), a one-way clutch, and the like. Further, the driving force transmission mechanism 104 includes a switching mechanism 170 (an example of a driving state switching unit) that switches a transmission destination of the driving force of the transport motor 102.

[Switching mechanism 170]
The switching mechanism 170 is configured to be switchable between a first drive state and a second drive state. The first driving state is a state in which the driving force of the conveying motor 102 transmitted through the conveying roller 60 is transmitted to the feeding roller 25 and not transmitted to the maintenance mechanism 70. The second driving state is a state in which the driving force of the transport motor 102 transmitted through the transport roller 60 is transmitted to the maintenance mechanism 70 without being transmitted to the feeding roller 25. As shown in FIG. 3A, the switching mechanism 170 is provided on the right side of the platen 42 (that is, the position deviated to the right from the passage region). As shown in FIG. 7, the switching mechanism 170 includes a switching gear 171, two receiving gears 172 </ b> A and 172 </ b> D, a holding portion 173, a pressing member 175, a switching lever 176, and a guide portion 177.

  The switching gear 171 can rotate about the support shaft 174 and can move along the axial direction of the support shaft 174 (that is, the left-right direction 9). The support shaft 174 is held by the maintenance mechanism 70. The driving force of the conveyance motor 102 is transmitted to the switching gear 171 through the conveyance roller 60. The receiving gears 172A and 172D can rotate coaxially along the left-right direction 9 on the lower side of the support shaft 174, and can be engaged with the switching gear 171. That is, the switching gear 171 meshes with one of the receiving gears 172A and 172D by moving in the left-right direction 9. The receiving gear 172 </ b> A is a gear that transmits the driving force of the transport motor 102 to the feeding roller 25. On the other hand, the receiving gear 172 </ b> D is a gear that transmits the driving force of the transport motor 102 to the maintenance mechanism 70.

  The pressing member 175 is disposed on the right side of the switching gear 171 and is inserted through the support shaft 174 so as to be slidable in the left-right direction 9. The switching lever 176 protrudes upward from the pressing member 175 and extends to the movement path of the carriage 23 through the holding portion 173. The switching gear 171 is urged to the right by the first spring, and the pressing member 175 is urged to the left by the second spring. Further, the biasing force of the second spring is larger than the biasing force of the first spring. As a result, the switching gear 171 and the pressing member 175 shown in FIG. 7 are urged to the left.

  When the switching lever 176 is held by the holding portion 173 at the first position shown in FIG. 7A, the switching gear 171 meshes with the receiving gear 172A. The switching lever 176 in contact with the carriage 23 that moves to the right moves the pressing member 175 to the right. At this time, the switching gear 171 moves to the right along with the movement of the pressing member 175 by the biasing force of the first spring. When the switching lever 176 is located at the second position shown in FIG. 7B, the switching gear 171 meshes with the receiving gear 172D.

  Further, the switching lever 176 moved to the third position shown in FIG. 7C by the carriage 23 and separated from the carriage 23 is moved to the first position shown in FIG. 7A by the urging force of the second spring. Return. In addition, since the switching lever 176 that moves from the third position to the first position is guided by the guide portion 177, the holding portion 173 does not prevent the return to the first position. The second position is a position farther from the passage area than the first position, and the third position is a position farther from the passage area than the first position and the second position.

  Further, when the switching gear 171 is engaged with the receiving gear 172D, the first spring has a natural length. Therefore, the switching gear 171 does not move to the right from the meshing position with the receiving gear 172D shown in FIG. That is, when the switching lever 176 is disposed at the second position and the third position, the switching gear 171 and the pressing member 175 are separated from each other. Further, the switching gear 171 is pressed by the pressing member 175 returning from the third position to the first position together with the switching lever 176, and moves to the meshing position with the receiving gear 172A shown in FIG.

  In a state where the switching gear 171 and the receiving gear 172A are engaged with each other (that is, in the first driving state shown in FIG. 7A), the driving force transmission mechanism 104 applies the driving force of the transport motor 102 to the feeding roller 25. And not to the maintenance mechanism 70. On the other hand, in a state where the switching gear 171 and the receiving gear 172D are meshed (that is, in the second driving state shown in FIG. 7B), the driving force transmission mechanism 104 uses the driving force of the transport motor 102 as a maintenance mechanism. 70 and not to the feeding roller 25.

  In addition, the driving force transmission mechanism 104 in which the switching mechanism 170 is in the first driving state does not transmit the forward driving force of the transport motor 102 to the feed roller 25, but rotates the feed roller 25 forward by the reverse rotation of the transport motor 102. Let In addition, the driving force transmission mechanism 104 in which the switching mechanism 170 is in the second driving state rotates the rotating body 92 by the normal rotation of the transport motor 102 and drives the pump 77 by the reverse rotation of the transport motor 102. These can be realized by a one-way clutch, a pendulum gear mechanism, an electromagnetic clutch mechanism, or the like provided in a driving force transmission path between the conveyance motor 102, the feeding roller 25, the rotating body 92, and the pump 77. Further, the discharge roller 62 is connected to the transport roller 60 via a belt or the like. That is, the transport roller 60 and the discharge roller 62 in the present embodiment rotate forward by the forward rotation of the transport motor 102 and reversely rotate by the reverse rotation of the transport motor 102 regardless of the state of the switching mechanism 170.

  Both the contact lever 76 of the maintenance mechanism 70 and the switching lever 176 of the switching mechanism 170 are moved by being pressed by the carriage 23 located to the right of the passage region. When the switching lever 176 is located at the first position shown in FIG. 7A (in other words, when the carriage 23 is separated from the switching lever 176 and the contact lever 76), the contact lever 76 is 4 (A). At this time, the cap 71 is located at the uncapping position. Further, the carriage 23 that contacts the switching lever 176 at the third position shown in FIG. 7C moves the contact lever 76 to the position shown in FIG. 4B. The cap 71 at this time is located at the cap position. Furthermore, the carriage 23 that contacts the switching lever 176 in the second position shown in FIG. 7B moves the contact lever 76 to a position between FIG. 4A and FIG. 4B. At this time, the cap 71 is located at the uncapping position.

[Control unit 130]
As shown in FIG. 8, the control unit 130 includes a CPU 131, a ROM 132, a RAM 133, an EEPROM 134, and an ASIC 135, which are connected by an internal bus 137. The ROM 132 stores a program for the CPU 131 to control various operations. The RAM 133 is used as a storage area for temporarily recording data and signals used when the CPU 131 executes the program, or as a work area for data processing. The EEPROM 134 stores settings, flags, and the like that should be retained even after the power is turned off.

  A transport motor 102 and a carriage motor 103 are connected to the ASIC 135. The ASIC 135 generates a drive signal for rotating each motor, and controls each motor based on this drive signal. Each motor rotates normally or reversely according to a drive signal from the ASIC 135. For example, the control unit 130 controls the driving of the conveyance motor 102 to drive each roller or the maintenance mechanism 70. The control unit 130 controls the recording head 39 to eject ink from the nozzles 40. In addition, the control unit 130 displays a message or animation on the display unit 14.

  In addition, a carriage sensor 38 is connected to the ASIC 135. The control unit 130 detects the position of the carriage 23 based on the pulse signal output from the carriage sensor 38. In addition, the control unit 130 acquires various instructions from the user through the operation unit 17.

  Further, the control unit 130 controls the drive of the carriage motor 103 to reciprocate the carriage 23. Specifically, the control unit 130 moves the carriage 23 at the first speed in the passage area. On the other hand, the control unit 130 moves the carriage 23 at a second speed that is lower than the first speed in a region deviated to the right side from the passage region (more specifically, a region that contacts the contact lever 76 or the switching lever 176). Move. As a result, it is possible to suppress the destruction of the meniscus of the ink droplets formed on the nozzles 40 of the recording head 39, and it is possible to suppress a decrease in throughput of the recording process described later.

[Image recording processing]
With reference to FIG. 9, the image recording process in the present embodiment will be described. This image recording process is executed by the CPU 131 of the control unit 130. The following processes may be executed by the CPU 131 reading out and executing a program stored in the ROM 132, or may be realized by a hardware circuit mounted on the control unit 130. The image recording process will be described by paying attention to the rotation of the feeding roller 25, the transport roller 60, and the discharge roller 62, the movement of the carriage 23, or the driving of the maintenance mechanism 70. These operations are realized by driving the transport motor 102 and the carriage motor 103 as described above.

  The control unit 130 executes the image recording process shown in FIG. 9 in response to obtaining a recording instruction from the user. The acquisition destination of the recording instruction is not particularly limited. For example, the recording instruction may be acquired through the operation unit 17 provided in the multifunction machine 10 or may be acquired from an external device through a communication network. The control unit 130 controls the operations of the rollers, the carriage 23, and the recording head 39 according to the acquired recording instruction, and executes image recording on the paper 12. In the present embodiment, while waiting for acquisition of a recording instruction, the cap 71 covers the recording head 39 in order to suppress drying of the ink of the nozzles 40. That is, the carriage 23 is disposed at a position where it abuts on the switching lever 176 at the third position. Further, the port switching mechanism 90 at this time is in an unlocked state shown in FIG.

  First, the control unit 130 moves the carriage 23 away from the switching lever 176. Thereby, the switching lever 176 returns to the first position, and the switching mechanism 170 switches from the second driving state to the first driving state. Next, the control unit 130 executes a feeding process for causing the paper 12 to reach the transport roller unit 54 by rotating the feeding roller 25 forward (S11). Next, the control unit 130 transfers the paper 12 that has reached the conveyance roller unit 54 to the conveyance roller 60 and the discharge roller 62 (hereinafter referred to as “conveyance unit”) by a predetermined line feed width in the first conveyance direction 16A. A recording process is performed in which the recording unit 24 records an image on the sheet 12 conveyed and conveyed by a predetermined line feed width (S12). Step S12 is an example of a unit operation, and is repeatedly executed until image recording on the sheet 12 is completed (S13: Yes).

  Further, the control unit 130 finishes one of the unit operations (S12) that is repeatedly executed (S13: No), and when the threshold time has elapsed since the immediately preceding empty discharge process (S14: Yes) ), An idle ejection process for idly ejecting ink to the recording head 39 toward the cap 71 is executed (S15). That is, each time the idle discharge process is executed, the control unit 130 measures the elapsed time from the point in time when the idle discharge process ends. The idle ejection process is not limited to the timing of step S15, and can be executed at the timing when the multifunction device 10 is turned on.

  Further, the control unit 130 counts the amount of ink ejected from the recording head 39 by the idle ejection process, and stores it in the EEPROM 134 or the like as the idle ejection amount. The idle discharge amount is accumulated every time the idle discharge process is executed, and is initialized by executing an idle suction process (S17) described later. On the other hand, the control unit 130 performs the process of step S12 without executing the processes of steps S15 to S18 in response to the fact that the threshold time has not elapsed since the idle discharge process executed immediately before (S14: No). Transition.

  In step S <b> 15, the control unit 130 moves the carriage 23 to the right until it comes into contact with the switching lever 176 at the second position. Typically, the control unit 130 moves the carriage 23 in contact with the switching lever 176 to the right until the switching lever 176 reaches the second position. As a result, the switching mechanism 170 is switched from the first drive state to the second drive state. Further, the cap 71 facing the recording head 39 rises halfway in conjunction with the contact lever 76 that is pressed by the carriage 23 and moves to the right, but is still in the uncapped position. Then, the control unit 130 causes the recording head 39 to eject ink idly toward the cap 71. As a result, the ink is discharged from the recording head 39 to the cap 71. It is assumed that the port switching mechanism 90 is in the unlocked state in FIG.

  Next, the control unit 130 executes the idle suction process (S17) in response to the idle discharge amount stored in the EEPROM 134 being equal to or greater than the threshold amount (S16: Yes). On the other hand, the control unit 130 proceeds to the process of step S12 without executing steps S17 and S18 in response to the idle discharge amount being less than the threshold amount (S16: No). The idle suction process is a process for discharging the ink stored in the cap 71 to the drainage tank 110 by driving the pump 77. Since the switching lever 176 is moved to the second position in step S15, the idle suction process is executed in a state where the switching mechanism 170 is switched to the second driving state. With reference to FIG. 10, the procedure of the idle suction process will be described.

  First, the control unit 130 switches the switching mechanism 170 to the Bk suction state (S21). Specifically, the control unit 130 switches the switching mechanism 170 from the unlocked state to the Bk suction state in the first step S21 in the idle suction process. That is, the control unit 130 rotates the rotating body 92 by the rotation angle α. The process of step S21 is an example of a first switching process. Note that, in step S21, the control unit 130 gradually rotates the rotating body 92 by switching the forward rotation and the reverse rotation of the transport motor 102 alternately instead of continuously rotating the transport motor 102 forward.

  Next, the control unit 130 drives the pump 77 to discharge the ink and the like in the Bk cap to the drainage tank 110 through the tubes 91A to 91C, the port switching mechanism 90, and the pump 77 (S22). The process of step S22 is an example of a first suction process. The controller 130 drives the pump 77 by 1 / N (N is a natural number) of the required drive amount of the pump 77 in one step S22. The required drive amount of the pump 77 indicates, for example, the drive amount necessary for sucking from the Bk cap an amount of ink or the like corresponding to the idle discharge amount stored in the EEPROM 134. Further, the control unit 130 counts the driving amount of the pump 77 in step S22 and stores it in the EEPROM 134 or the like. This drive amount is accumulated every time step S22 is executed, and is initialized when the idle suction process is started.

  Next, the control unit 130 switches the port switching mechanism 90 to the Co suction state (S23). Specifically, the control unit 130 switches the port switching mechanism 90 from the Bk suction state to the Co suction state. That is, the control unit 130 rotates the rotating body 92 by the rotation angle β. The process of step S23 is an example of a second switching process. In step S23, the control unit 130 may continue to rotate the conveyance motor 102 in order to rotate the rotating body 92 by the rotation angle β. Alternatively, the control unit 130 may alternately switch between normal rotation and reverse rotation of the conveyance motor 102. Also good.

  Next, the control unit 130 drives the pump 77 to discharge the ink or the like in the Co cap to the drainage tank 110 through the tubes 91A to 91C, the port switching mechanism 90, and the pump 77 (S24). The process of step S24 is an example of a second suction process. The controller 130 drives the pump 77 by 1 / N of the required drive amount of the pump 77 in one step S24. The driving amount of the pump 77 may be counted in step S22, may be counted in step S24, or may be counted independently in steps S22 and S24.

  Next, in response to the fact that the drive amount of the pump 77 stored in the EEPROM 134 has not reached the required drive amount (S25: No), the control unit 130 executes the processes of steps S21 to S24 again. That is, in the present embodiment, the cycle of steps S21 to S24 is executed N times. Note that the controller 130 switches the port switching mechanism 90 from the Co suction state to the Bk suction state in the second and subsequent steps S21 in the idle suction processing. That is, the control unit 130 rotates the rotating body 92 by the rotation angle γ. Other processes are the same as those described above, and a description thereof will be omitted.

  Then, in response to the drive amount of the pump 77 reaching the required drive amount (S25: Yes), the control unit 130 switches the port switching mechanism 90 from the Co suction state to the unlocked state (S26). That is, the control unit 130 rotates the rotating body 92 by the rotation angle θ. In step S26, the control unit 130 may continue to rotate the conveyance motor 102 in order to rotate the rotating body 92 by the rotation angle θ, or alternately switch between normal rotation and reverse rotation of the conveyance motor 102. Also good.

  Returning to FIG. 9, the control unit 130 executes the inversion process (S18), and executes the processes after step S12 again. The reversing process is a process of returning the sheet 12 conveyed by the conveying unit when the conveyance motor 102 is driven in the idle suction process to a position before the idle suction process is executed. That is, in step S18, the control unit 130 reverses the carry motor 102 by the total rotation amount R of the carry motor 102 in the idle suction process.

  Specifically, the total rotation amount R of the conveyance motor 102 in the idle suction processing corresponds to the sum of the normal rotation amount R1 and the reverse rotation amount R2 of the conveyance motor 102 in steps S21 to S24 and S26. The total rotation amount R is, for example, the sum of the conveyance motor 102 with the normal rotation amount R1 as a positive value and the reverse rotation amount R2 as a negative value. When the total rotation amount R in the idle suction process is a positive value (that is, the forward rotation is greater than the reverse rotation), the control unit 130 reverses the transport motor 102 by the total rotation amount R in step S18. On the other hand, when the total rotation amount R in the idle suction process is a negative value (that is, the reverse rotation is greater than the normal rotation), the control unit 130 causes the transport motor 102 to rotate forward by the total rotation amount R in step S18. .

  Then, in response to the end of image recording on the sheet 12 (S13: Yes), the control unit 130 executes a discharge process for discharging the sheet 12 to the discharge tray 21 (S19). Specifically, the control unit 130 rotates the transport unit in a forward direction until the rear end of the sheet 12 (refers to the “upstream end of the first transport direction 16 </ b> A”) passes the discharge roller unit 55. And the control part 130 repeatedly performs the process of step S11-S22 until all the image recording contained in a recording instruction is complete | finished (S20: No).

[Operational effects of this embodiment]
In the MFP 10 configured as described above, when the transport motor 102 is rotated forward in the idle suction process, the paper 12 sandwiched between at least one of the transport roller unit 54 and the discharge roller unit 55 is transported in the first transport direction 16A. . On the other hand, when the transport motor 102 is reversed in the idle suction process, the paper 12 is transported in the second transport direction 16B. That is, when the forward rotation amount and the reverse rotation amount of the transport motor 102 in the idle suction process do not match, the paper 12 during the image recording process is arranged at different positions before and after the idle suction process.

  Therefore, according to the reversing process of the above embodiment, the sheet 12 conveyed by the driving of the conveyance motor 102 during the idle suction process can be returned to the position before the idle suction process is executed. Thereby, even if the idle ejection process and the idle suction process are executed during the image recording process, the positional deviation of the paper 12 can be suppressed. As a result, the meniscus in the nozzle 40 can be maintained in an appropriate state, and an image can be appropriately recorded on the paper 12.

  Note that if the conveyance motor 102 continues to rotate normally in the idle suction process, the sheet 12 may pass through the nipping position of the conveyance roller unit 54 or the discharge roller unit 55. In this case, it is difficult to return the paper 12 to the original position only by matching the forward rotation amount and the reverse rotation amount of the transport motor 102. Therefore, in the first switching process in the above embodiment, the rotating body 92 is rotated while alternately switching the forward rotation and the reverse rotation of the transport motor 102, whereby the sheet is placed in one of the first transport direction 16A or the second transport direction 16B. It is suppressed that 12 moves large. Here, when the transport motor 102 is reversed in the first switching process, the pump 77 is driven, but there is no particular problem because the cap 71 and the pump 77 are not in communication. The same applies to steps S23 and S26.

  However, the process of switching the forward / reverse rotation of the transport motor 102 in the first switching process or the like is not essential. Even in this case, the first switching process and the second switching process in which the transport motor 102 is normally rotated, and the first suction process and the second suction process in which the transport motor 102 is reversed are executed alternately. An effect of suppressing the sheet 12 from moving greatly in one of the transport direction 16A or the second transport direction 16B can be expected.

  In addition, the above-described problem may occur even when the conveyance motor 102 is continuously reversed in the idle suction process. However, when the transport motor 102 is rotated forward in the first suction process and the second suction process, the communication state of the port switching mechanism 90 is switched. Therefore, as in the above embodiment, the drive amount of the pump 77 per first suction process and second suction process is set to 1 / N of the required drive amount, and the cycle of steps S21 to S24 is repeated N times. , The paper 12 is prevented from greatly moving to one side.

DESCRIPTION OF SYMBOLS 10 ... Multifunction machine 23 ... Carriage 39 ... Recording head 40 ... Nozzle 54 ... Conveyance roller part 55 ... Discharge roller part 70 ... Maintenance mechanism 71 ... Cap 76 ... Pump 90 ... Port switching mechanism 102 ... Conveyance motor 130 ... Control unit 176 ... Switching lever

Claims (6)

A transport unit that transports the sheet in the transport direction;
A carriage that moves in the main scanning direction intersecting the transport direction;
A recording head mounted on the carriage and ejecting ink from nozzles;
A maintenance unit having a cap facing the recording head at a position deviated from the passage region of the sheet conveyed by the conveyance unit to one end side in the main scanning direction, and a pump for sucking ink in the cap;
A motor for driving the transport unit and the maintenance unit;
A driving state switching unit capable of switching between a first driving state in which the driving force of the motor is not transmitted to the maintenance unit and a second driving state in which the driving force is transmitted to the maintenance unit;
A control unit, and
The control unit
Performing a recording process including a plurality of unit operations for causing the sheet to be conveyed to the conveying unit by a predetermined line feed width in the conveying direction and ejecting ink to the recording head with respect to the sheet;
Among the above unit operations,
An idle ejection process for causing the carriage to move to a position where the recording head faces the cap and ejecting ink to the recording head idle;
In the state where the drive state switching unit is in the second drive state, an empty suction process for sucking ink in the cap by the pump;
An ink jet recording apparatus that performs a reversing process of reversing the motor by a total rotation amount of the motor rotated in the idle suction process. The recording head is
A first nozzle for discharging a first color ink;
A second nozzle that ejects ink of a second color different from the first color,
The maintenance department
A first cap that is the cap that can face the first nozzle;
A second cap that is the cap that can face the second nozzle;
The pump for sucking ink in the cap by reversing the motor;
A communication state switching unit capable of alternately switching a first communication state in which the pump and the first cap are in communication and a second communication state in which the pump and the second cap are in communication with each other by forward rotation of the motor; , And
The transport unit is
The sheet is conveyed in the conveying direction by forward rotation of the motor,
The sheet is conveyed in the opposite direction to the conveying direction by the reverse rotation of the motor,
In the idle suction process, the control unit
A first switching process for switching the communication state switching unit to the first communication state;
A first suction process for sucking ink from the first cap to the pump;
A second switching process for switching the communication state switching unit to the second communication state;
A second suction process for causing the pump to suck ink from the second cap,
The total rotation amount corresponds to a sum of a forward rotation amount of the motor in the first switching process and the second switching process and a reverse rotation amount of the motor in the first suction process and the second suction process. Item 10. The ink jet recording apparatus according to Item 1.   The inkjet recording apparatus according to claim 2, wherein the controller repeats a cycle of the first switching process, the first suction process, the second switching process, and the second suction process a plurality of times in the idle suction process. .   In the first switching process in which the amount of normal rotation of the motor is larger than that in the second switching process, the control unit alternately repeats normal rotation and reverse rotation of the motor, thereby setting the communication state switching unit to the first communication process. The ink jet recording apparatus according to claim 2 or 3, wherein the ink jet recording apparatus is switched to a state.   5. The control unit according to claim 1, wherein the control unit executes the idle ejection process in response to a threshold time having elapsed and one of the plurality of unit operations being completed during the recording process. Inkjet recording device.   The ink jet recording apparatus according to claim 1, wherein the control unit executes the idle suction process and the inversion process in response to an ink discharge amount in the idle discharge process reaching a threshold amount. .

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