JP4710587B2 - Inkjet printer - Google Patents

Description

  The present invention relates to an ink jet printer, and more particularly to an ink jet printer capable of suppressing a recording medium from remaining in a conveyance path when ink shortage occurs.

  2. Related Art Ink jet printers that print on recording paper by ejecting ink from a print head in which a plurality of ink ejection openings are formed have been put into practical use. In such an ink jet printer, recording paper fed from a paper feed cassette is conveyed by a conveyance roller, and an image is printed by reciprocating a print head in a direction orthogonal to the conveyance direction. Conventionally, after a series of operations of paper feeding, printing, and paper ejection are completed, the next recording paper is sequentially sent out from the paper feeding cassette.

  For example, as disclosed in Patent Document 1, a printing method has been proposed in which the next recording sheet is fed from a sheet feeding cassette during printing on one recording sheet. In this way, after the printing on one recording sheet is completed, the time until the leading edge of the next recording sheet reaches the printing position is shortened, so that the printing speed is improved.

In addition, the normal recording mode that does not feed the next recording sheet during printing of the preceding recording sheet with emphasis on image quality, and the feeding of the next recording sheet during printing of the preceding recording sheet with emphasis on high-speed printing. Ink jet printers that can be switched to paper feeding and transport operations according to each mode are conceivable so that the user can appropriately select a continuous paper feeding mode for starting paper.
JP 2001-301282 A

  However, if printing is stopped for some reason during printing in which the continuous paper feed mode is set, the recording paper sent out from the paper feed cassette to the transport path remains stopped in the transport path. If such a residual state continues for a long time, especially in a U-turn-shaped conveyance path, a curved wrinkle along the curved path is left on the recording medium, so if it is conveyed as it is at the next printing opportunity, it enters the lower part of the print head. Occasionally, paper jams occur, the gap between the print head and the surface of the recording paper is too small, or contact occurs. In particular, when printing is interrupted due to insufficient ink in the ink tank, printing does not resume until the ink tank is replaced. Therefore, if the user leaves the ink tank for a long time without replacing it, the conveyance path The recording paper remaining on the recording medium also has a long standby time, which causes the above-described disadvantage.

  When the ink shortage occurs, the user who notices the ink shortage replaces the ink tank. After the ink tank replacement, a purge process is usually performed. The purge process is a process in which a print head is covered with a cap and sealed, and ink is sucked from the print head by a pump. By performing the purge process when a new ink tank is mounted, it is possible to remove air bubbles that have entered during ink tank replacement.

  Here, for the purpose of reducing the number of parts, the pump for the purge process and the conveyance roller for conveying the recording paper may be driven by a common drive motor. Therefore, when the drive motor is rotated to perform the purge process, the transport roller vibrates slightly due to the influence. Therefore, if the recording paper remains in the transport path when the ink tank is replaced, the recording paper remaining in the transport path is displaced due to the influence of the vibration of the transport roller due to the purge process after the ink replacement. There is a fear. If the position in the transport path is shifted and transported as it is at the next printing opportunity, it is not transported accurately to the print position by the print head, and the image quality deteriorates.

  In order to solve the above-mentioned inconvenience, it may be possible to provide a separate mechanism for reversely feeding a recording sheet that has been once sent to the conveyance path but not used for printing, but the manufacturing cost of the apparatus increases. New inconvenience arises.

  SUMMARY An advantage of some aspects of the invention is that it provides an ink jet printer capable of suppressing a recording medium from remaining in a conveyance path when ink shortage occurs.

In order to achieve this object, an ink jet printer according to claim 1 is provided with an ink discharge port for discharging ink supplied from an ink tank and capable of printing an image on a recording medium, and an ink of the print head. Maintenance means for performing maintenance for sucking ink from the discharge port, ink tank replacement determining means for determining whether the ink tank has been replaced, and feeding the recording medium accumulated in the paper feed cassette one by one to the transport path. And an ink for obtaining a value relating to a remaining amount of ink in the ink tank, and a conveying means for discharging the recording medium after the printing by the print head is finished. A tank remaining amount acquisition unit, wherein the conveyance unit conveys the recording medium conveyed via the conveyance path more than the image recording unit. A pair of clamping means for clamping at the upstream, in the conveying path, said conveying means as the sheet feeding to the conveying path of the subsequent recording medium during printing of a recording medium conveyed earlier is started It is determined whether or not the succeeding recording medium can be printed during execution of the continuous paper feeding mode to be operated based on a value relating to the remaining ink amount acquired by the remaining ink amount acquiring unit , and the succeeding recording medium Is determined to be unable to be printed, the transport path of the subsequent recording medium during recording on the previously transported recording medium before the subsequent recording medium is sandwiched by the sandwiching means. Switch to the normal paper feed mode to operate the transport means so as to suppress the paper feed, and after the printing on the previously transported recording medium, the transport by the transport means is stopped and the ink tank is replaced Octopus Wherein the ink tank exchanging means to determine the maintenance unit performs maintenance, and the maintenance unit, wherein the conveying means is a drive source of the same drive motor.

3. The ink jet printer according to claim 1, wherein the transport means feeds the recording medium deposited on the paper feed cassette one by one to the transport path, and the printing. And a drive roller for transporting the recording medium being printed by the head in the transport direction, and when the normal paper feeding mode is selected, the recording medium being printed is transported in the transport direction by the forward rotation of the drive roller. At this time, the paper feed roller is rotationally driven in a direction opposite to the paper feed direction, and suppresses the feeding of the subsequent recording medium to the transport path .

An ink jet printer according to a third aspect of the present invention is the ink jet printer according to the second aspect, wherein the clamping means includes the drive roller.

According to the ink jet printer according to claim 1, when the continuous paper feeding mode is selected, whether or not the subsequent recording medium can be printed is based on the value related to the remaining ink amount acquired by the remaining ink amount acquiring unit. Is judged. When it is determined that the subsequent recording medium cannot be printed, the continuous paper supply mode is switched to the normal paper supply mode. In the normal paper feeding mode, the feeding of the subsequent recording medium to the conveyance path is suppressed during printing on the recording medium conveyed first in the conveyance path. Therefore, by switching from the continuous paper feed mode to the normal paper feed mode during printing on the last recording medium that can be printed with the remaining ink amount in the ink tank, the subsequent recording medium (that is, the remaining ink amount in the ink tank). Thus, the feeding of the recording medium that cannot be printed to the conveyance path is suppressed. Then, after the printing on the last recording medium that can be printed with the remaining amount of ink in the ink tank is completed, the conveyance by the conveying means is stopped, so that when the ink shortage occurs, the recording medium remains in the conveying path. There is an effect that can be suppressed.
In addition, when the ink tank is replaced, there is no recording medium that cannot be printed remaining in the transport path, so that the displacement of the recording medium due to the ink ejection state recovery operation that is performed when the ink tank is replaced is suppressed, and recording is performed in the image recording unit. There is an effect that the medium can be accurately conveyed. That is, when the maintenance unit and the transport unit use the same drive motor as the drive source, if the recording medium remains in the transport path when the ink tank is replaced, the ink discharge state recovery operation is performed when the ink tank is replaced. In this case, the conveying means slightly vibrates, the position of the recording medium in the conveying path is shifted, and there is a possibility that the conveying means is not accurately conveyed to the image recording unit.

According to the ink jet printer according to claim 2, in addition to the effect of the ink jet printer according to claim 1, when the continuous paper feed mode is switched to the normal paper feed mode during printing on the last printable recording medium, When the last printable recording medium is transported in the transport direction by forward rotation of the drive roller, the paper feed roller is rotationally driven in the direction opposite to the paper feed direction. Therefore, even if the feeding of the recording medium from the paper feeding cassette is started by the paper feeding roller before the continuous paper feeding mode is switched to the normal paper feeding mode, the continuous paper feeding mode is changed to the normal paper feeding mode. After the switching, the sheet feeding roller is driven to rotate in the direction opposite to the sheet feeding direction, so that the recording medium that has started feeding is returned to the sheet feeding cassette. Therefore, there is an effect that it is possible to prevent the recording medium from remaining in the transport path when ink shortage occurs without separately providing a mechanism for reversely feeding the recording medium.
In addition, since the continuous paper feeding mode is switched to the normal paper feeding mode before the leading edge of the subsequent recording medium is sandwiched by the pair of clamping means, the paper feeding roller rotates in the direction opposite to the paper feeding direction. By driving, the recording medium can be reliably returned to the paper feed cassette.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings. 1 is an overall perspective view of a multifunctional image recording apparatus 1 according to an embodiment of the ink jet printer of the present invention, FIG. 2 is a perspective view of a main body case with an upper case removed, and FIG. 3 is a main body with an upper case removed. FIG. 4 is a side sectional view of the main part of the image recording unit, the paper feeding cassette, and the paper feeding unit, FIG. 5 is a side sectional view of the main part of the recording unit, and FIG. 6 is a side view of the paper feeding unit. 7 is a partially cutaway plan view of the recording unit with the paper feed cassette mounted thereon, FIG. 8 is a perspective view of the recording unit unit with the downstream guide plate and platen removed, and FIG. 9 is an IX of FIG. -IX line side view, FIG. 10 is an explanatory diagram of the power transmission switching means, FIG. 11 is an explanatory diagram of the action in each work mode, FIGS. 12 (a) to 12 (b) are an explanatory diagram of the action in the normal mode, FIG. 13 (a) to 13 (c) are diagrams for explaining the operation in the continuous feeding mode, and FIG. FIG. 15 is a flowchart of control.

  A multifunction image recording apparatus 1 shown in FIG. 1 has a facsimile function, a printer function, a copying function, a scanner function, and the like. An image recording apparatus 1 which is a multi-function device includes a substantially box-shaped main body case 2 having an open top surface and a hinge, a side of the main body case 2 (left side in the embodiment of FIG. 1), And an upper case 3 pivotally attached so as to be pivotable up and down via a pivot axis portion (not shown) such as a hinge portion. In the following description, the front side of the image recording apparatus 1 in FIG. 1 is the front side, and the horizontal direction (main scanning direction, Y-axis direction), the front-rear direction (sub-scanning direction, X-axis direction), and the vertical direction are also described. Description will be made with reference to the orientation of the image recording apparatus 1 in FIG. The main body case 2 and the upper case 3 are synthetic resin injection molded products.

  An operation panel 30 is disposed on the upper front portion of the upper case 3. The operation panel 30 is provided with various buttons such as a numeric button, a start button, and a function operation button, and various operations are performed by pressing these buttons. The operation panel 30 is provided with a display unit 31 such as a liquid crystal (LCD), and the setting state of the image recording apparatus 1 and various operation messages are displayed as necessary.

  In the upper case 3, a scanner device (image reading unit) 33 is disposed on the rear side of the operation panel 30. That is, the scanner 33 for reading a facsimile original to be transmitted to the other facsimile apparatus during the facsimile function and an image of the original to be copied during the copying function includes a flat bed reading unit that reads an image of the original on a large glass plate. , And a rotatable cover body 34 covering the upper surface of the flat bed reading unit.

  Although not shown, a line-type contact image sensor (CIS: Contact Image) as an example of a photoelectric conversion element for reading an image surface of a document in contact with the glass plate is provided directly below the glass plate in the flat bed reading unit. Sensor) is provided so as to be capable of reciprocating along a guide shaft extending in a direction parallel to a carriage movement direction (main scanning direction, Y-axis direction) described later.

  Note that the cover body 34 is configured to be openable and closable via a hinge around the back side (the back side in FIG. 1) of the image recording apparatus 1.

  The upper case 3 can be greatly opened upward with respect to the main body case 2 with the left end portion in FIG. 1 as the center, and the lower surface of the upper case 3 serves as an open posture holding means for holding the opened posture. A guide rail (not shown) having a guide groove hole is fixed to one side (portion close to the back side of the image recording apparatus 1) so as to extend in the direction parallel to the moving direction of the image sensor. Then, a guide pin at the tip (upper end) of a support rod (not shown) whose base end is pivotally mounted on the side farther from the pivot axis portion in the main body case 2 is movably inserted into the guide rail. To do. Then, the upper case 3 is attached to the main body case 2 in a state in which the guide pin is fitted in an engaging portion (not shown) formed by notching upward in the guide groove hole on the side far from the rotation axis portion. On the other hand, it is configured so that it can be held at a predetermined large opening angle.

  Next, the configuration of the printer device (recording unit) will be described. As shown in FIG. 1, a paper feed cassette 5 for placing a plurality of sheets of recording media P as a recording medium in a substantially horizontal state in a stacked state is arranged at the bottom in the center in the left-right direction in the main body case 2. The paper feed cassette 5 is configured to be able to be pulled out with respect to the opening 2 a on the front surface of the main body case 2. A separation member (not shown) having a large friction coefficient is arranged on the separation inclined surface 8 (see FIG. 4) provided at the front end of the paper feed cassette 5.

  Further, in the main body case 2, a feeding unit 6 as a feeding means provided with a paper feeding roller 7 above the paper feeding cassette 5, and an upward U-shaped U-turn at the rear end portion in the main body case 2. Ink is applied to the surface of the sheet P (recording medium) on the platen 11 serving as a flat sheet support portion disposed in the conveyance path, and a conveyance path that conveys the sheet P in a generally horizontal direction forward via the conveyance path 9. And a recording unit 10 including an ink jet recording head 12 that records an image by ejecting the ink (see FIGS. 2, 3, and 4).

  An ink tank 26 for supplying ink to the recording head 12 for color recording is provided on the inner surface of the side plate in the main body case 2 at a position farthest from the side plate having the rotation axis portion. It is configured to be detachable from above with respect to the accommodating portion 27 (see FIG. 3) at a close position. The ink tank 26 stores ink for each of a plurality of colors. In the embodiment, the ink tank 26 has four colors of black, cyan, magenta, and yellow. However, inks of more colors may be stored. Ink is supplied from each ink tank 26 to the recording head 12 by connecting a flexible ink tube 28.

  2 to 5, the recording unit 10 includes a carriage 13 having a recording head 12, a plate-like platen 11 made of synthetic resin, a CR (carriage) motor 24 for reciprocating the carriage 13, and the CR. The timing belt 25 connected to the motor 24 and an engine frame 39 made of a metal plate for supporting them are mainly configured. The engine frame 39 is disposed on the rear side of the main body case 2 and above the paper feed cassette 5. The engine frame 39 as a support frame is made of metal, and as shown in FIGS. 2 to 5, on the upper side of the box-shaped main body 39 a in the left-right direction (main scanning direction, Y-axis direction) of the main body case 2. A pair of guide plates 40 and 41 that extend and slidably support the carriage 13 are mounted.

  A timing belt 25 disposed so as to extend in the main scanning direction (Y-axis direction) is provided on the upper surface of the guide plate 41 disposed on the downstream side in the sheet feeding direction (see the arrow A direction in FIG. 4). It is wound around 25b. A carriage 13 on which the recording head 12 is mounted is connected to a part of the timing belt 25.

  A linear encoder (encoder strip) 37 (see FIG. 7) is arranged on the upper surface of the guide plate 41 so as to extend along the longitudinal direction (main scanning direction), and the Y axis direction (main scanning direction) of the carriage 13 is arranged. Detecting the position and direction of movement. The strip-shaped linear encoder (encoder strip) 37 is arranged such that the inspection surface (the surface on which slits are arranged at regular intervals in the Y-axis direction) is along the vertical direction.

  A driving shaft 14 and a paper feeding arm 6a of the feeding unit 6 are pivotally fixed to the main body 39a of the engine frame 39, and a flat plate for supporting the paper P facing the lower surface of the recording head 12. A platen 11 is disposed (see FIG. 4). Here, an area between the lower surface of the recording head 12 and the platen 11 is referred to as an image recording unit described in the claims. The paper feed arm 6a is constantly urged in the downward rotation direction by a torsion spring 38 (see FIG. 6) as urging means. As shown in FIG. 4, a gear transmission mechanism 50 including a plurality of meshing gears for transmitting a rotational force from the drive shaft 14 to the sheet feeding roller 7 is disposed on the sheet feeding arm 6 a of the feeding unit 6. .

  Further, of the registration roller (conveyance roller) pair 20 that is disposed on the upstream side in the conveyance direction across the platen 11 and sends the paper P to the image recording unit that is the lower surface of the recording head 12, both ends of the drive roller 20a The paper discharge roller pair 21 is disposed downstream of the platen 11 in the transport direction and transports the recorded paper P toward the paper discharge unit (see the arrow B direction in FIGS. 1 and 4). Both ends of the driven paper discharge roller 21a are rotatably supported by shaft support portions provided on the pair of side plates 39b and 39c in the engine frame 39. The conveyed paper P is nipped between the drive roller 20a located on the upper surface side and the driven roller 20b located on the lower surface side. Further, the driven paper discharge roller 21a in the paper discharge roller pair 21 comes into contact with the lower surface of the paper P to be discharged, and the spur 21b is nipped so as to contact the upper surface of the paper P.

  On the outside of the width of the paper P to be conveyed (short side of the paper P), one end side (in the embodiment, the main body 39a of the engine frame 39 is placed on the left side plate 39b when viewed from the paper P feeding direction. An ink receiving portion 35 is disposed in the vicinity (a portion near), and a maintenance portion 36 including a maintenance unit is disposed on the other end (a portion close to the right side plate 39c) (see FIG. 3). As a result, the recording head 12 periodically discharges ink to prevent nozzle clogging during the recording operation at the flushing position provided in the ink receiving portion 35, and receives ink at the ink receiving portion 35.

  The drive roller 20a, the discharge roller 21a, and the maintenance unit 36 receive power from one common drive motor (LF motor) 42 disposed in the vicinity of the side plate 39b on the opposite side of the maintenance unit 36. It is transmitted via a predetermined gear transmission mechanism 43 (see FIGS. 7, 9 and 10). As shown in FIGS. 9 and 10, the gear transmission mechanism 43 includes a pinion 43a attached to a drive shaft of a LF motor 42 that can rotate forward and backward (for paper conveyance), and a transmission gear 43b that meshes with the pinion 43a on the left and right. The intermediate gear 43c includes a transmission gear 43d that meshes with the intermediate gear 43c, and the transmission gear 43b is attached to one side (left end portion) of the drive roller 20a in the registration roller pair 20. The other transmission gear 43 d is attached to one end (left end portion) of the paper discharge roller 21 a in the paper discharge roller pair 21. When the sheet P is fed closer to the image recording unit via the U-turn conveyance path 9 on the upstream side of the conveyance position than the arrangement position of the registration roller pair 20, the leading end position and the end position of the sheet P are set. A paper detection body 116 for detection is provided (see FIG. 5), and a registration sensor 117 as a paper sensor is provided in association therewith (see FIGS. 12 and 13).

  In the embodiment, the rotational force from the LF motor 42, which is a DC motor, is transmitted from the other end of the drive roller 20a in the registration roller pair 20 via the power transmission switching means 100 disposed on the maintenance unit 36 described later. Then, power is selectively transmitted to the sheet feed roller 7 of the feeding unit 6 and the maintenance mechanism (not shown in detail) of the maintenance unit 36.

  As described above, since the driving roller 20a and the paper discharge roller 21a are positioned above and below the paper conveyance path, the driving roller 20a and the paper discharge roller 21a are driven by the rotational drive of the LF motor 42 in a predetermined direction. Will rotate in opposite directions.

  A part of the gear transmission mechanism 43 is provided with a rotary encoder 44 for detecting the transport amount of the paper P by the transport roller pair 20a (see FIG. 8). Both the CR motor 24 and the LF motor 42 are configured to be able to rotate forward and reverse.

  Note that a spur 51 is arranged at a position downstream of the image recording area by the nozzle surface of the recording head 12 and between the discharge roller pair 21 and close to the upper surface of the platen 11 (see FIG. 5). As a result, the image-recorded paper P is lifted and does not slide on the nozzle surface, so that the image quality is not deteriorated due to ink stains.

  Next, the configuration of the power transmission unit and the power transmission switching unit 100 for the driving force for the feeding unit 6 and the maintenance unit 36 will be described with reference to FIGS. The power transmission switching means 100 switches the driving mode of the paper feeding roller 7 in the feeding unit 6 between the normal paper feeding mode and the continuous paper feeding mode. In the present embodiment, the “mode” refers to a continuous operating state unless switched by the power transmission switching means 100.

  As described above, the rotational force from the LF motor 42 capable of forward and reverse rotation is transmitted to the drive roller 20a in the registration roller pair 20 via the reduction gear 43b. One long drive gear 101 in the power transmission switching means 100 is provided at the right end portion (maintenance portion 36) of the drive roller 20a so as to rotate integrally. One switching gear 102 that always meshes with the drive gear 101 is configured to be slidable with respect to a support shaft 103 arranged in parallel with the axis of the drive roller 20a. A first block 104 having a contact piece 104a extending upward is fitted on the support shaft 103 so as to be slidable and rotatable. The second block 105 adjacent to the first block 104 is slidably fitted to the support shaft 103. The first block 104 can be separated from one side of the switching gear 102.

  The first urging spring 106a fitted on the support shaft 103 presses the second block 105 in the direction of arrow C in FIG. 10, and the second urging spring 106b moves the switching gear 102 in the direction of arrow E in FIG. Press. In this case, the biasing force of the first biasing spring 106a is set to be larger than the force of the second biasing spring 106b. Then, the contact piece 104a can be received by the first engagement step portion 13a or the second engagement step portion 13b of the carriage 13, and the switching is performed according to the movement of the carriage 13 in the arrow C direction or the arrow E direction. The gear 102, the first block 104, and the second block 105 are slid along the support shaft 103 and moved in the direction of arrow C or arrow E. An end face cam portion (not shown) that is inclined with respect to the axis of the support shaft 103 is formed at a facing portion between the first block 104 and the second block 105. When pushing 104 in the direction of arrow C, the contact piece 104a rotates in the direction of arrow D in FIG. 10 (the front side of the paper in FIG. 11).

  As shown in FIG. 11 (a), a plate-like guide block 107 having a guide groove 109 in which the tip end portion of the contact piece 104a can slide up and down is located above the first block 104. Has been placed. As shown in FIG. 11B in plan view, the guide groove 109 includes a straight groove 109a that is long in the directions of arrows C and E, and a clockwise annular groove 109b that communicates with the left end of the straight groove 109a. Prepare. In the embodiment, the restricting piece 110 extending downward from above the guide block 107 is made to face the central portion of the annular groove 109b. The restriction piece 110 is along the straight groove 109a. A stepped first set portion 111 and a second set portion 112 are provided on one side of the annular groove 109b.

  As shown in FIG. 11B, when the carriage 13 is greatly moved in the arrow C direction from the maintenance unit 36 and is in the recording area for the paper P, the first biasing spring 106a is pushed in the arrow C direction. The first block 104 and the switching gear 102 move along the support shaft 103 via the two blocks 105. The contact piece 104 a in the first block 104 is located in the first set portion 111. This position is referred to as position 1 (Po1). At this time, the switching gear 102 meshes with the intermittent sheet feeding transmission gear 113. Next, when the carriage 13 moves in the arrow E direction by the maintenance unit 36, the contact piece 104 a is pushed by the first engagement step portion 13 a in the carriage 13. When the contact piece 104a is positioned at the second set portion 112 (position 2, Po2), the switching gear 102 is engaged with the continuous paper feed transmission gear 114. When the carriage 13 further moves in the direction of arrow E, the contact piece 104a pushed by the first engagement step portion 13a moves along the connecting inclined surface to the linear groove portion 109a in the annular groove portion 109b. At an initial position where the contact piece 104a enters the linear groove 109a (this position is referred to as position 3 (Po3)), the contact piece 104a is engaged with the second engagement step portion 13b of the carriage 13. At this time, the switching gear 102 meshes with the maintenance transmission gear 115. The switching gear 102, the intermittent paper feed transmission gear 113, the continuous paper feed transmission gear 114, and the maintenance transmission gear 115 are spur gears. A large-diameter bevel gear 115a is integrally formed on the side surface of the maintenance transmission gear 115. It is provided to rotate. When the carriage 13 further moves in the direction of arrow E from position 3 (Po3), the side surface of the switching gear 102 abuts against the bevel gear 115a and is prevented from moving in the direction of arrow E and is separated from the first block 104. The switching gear 102 is kept in mesh with the maintenance transmission gear 115. The contact piece 104a is pushed by the second engagement step portion 13b in the carriage 13 and is positioned at the end portion (the right end portion in FIG. 12B) of the linear groove portion 109a. This position is called position 4 (Po4) and is usually the home position (origin position).

  Contrary to the above, when the carriage 13 moves from the position 4 (Po4) in the direction of arrow C and the contact piece 104a moves from the linear groove 109a to the annular groove 109b, the contact piece 104a at the first engagement step portion 13a. Since the contact piece 104a does not enter the connecting inclined surface, the contact piece 104a is slidably contacted with the regulating piece 110 at the left end portion along the left inclined surface of the annular groove 109b in FIG. Thus, the contact piece 104a is engaged with the first set part 111 so that it can move cyclically.

  The position 3 (Po3) is a maintenance position that also serves as a standby position. At the maintenance position also serving as the standby position, the cap portion 36a in the maintenance portion 36 covers the nozzle surface of the recording head 12 from below. The LF motor 42 is driven, and a suction pump (not shown) is operated to selectively suck ink from the nozzles, or a recovery process for removing bubbles in a buffer tank (not shown) on the recording head 12. Do. When the carriage 13 moves laterally from the maintenance unit 36 to the image recording area (left direction in FIG. 7), cleaning is performed by wiping the nozzle surface with a cleaner (wiper blade) 36b. In a state where the image recording apparatus 1 is not turned on, the carriage 13 is stopped at the upper surface position of the maintenance unit 36 (position 3 (Po3)), and the nozzle portion of the recording head 12 in the carriage 13 is the maintenance unit. It is closely attached and covered by a cap portion 36a on the upper surface of 36 (see FIG. 7). Even at the home position (origin position), the nozzle portion is covered and covered with the cap portion 36a.

  At position 1 (Po1) where the switching gear 102 meshes with the intermittent paper feed transmission gear 113, as shown in FIGS. 12 (a) and 12 (b), the paper feed arm 6a is connected via two intermediate gears 119a and 119b. Power is transmitted to the drive shaft 14 at the base end, and the paper feed roller 7 is rotated via the gear transmission mechanism 50.

  On the other hand, at the position 2 (Po2) where the switching gear 102 meshes with the continuous paper feed transmission gear 114, the paper feed arm 6a is interposed via one intermediate gear 120 as shown in FIGS. Power is transmitted to the drive shaft 14 at the base end, and the paper feed roller 7 is rotated via the gear transmission mechanism 50.

  Next, the control unit of the image recording apparatus 1 will be described with reference to FIG. This control unit controls the overall operation of the image recording apparatus 1.

  This control unit is configured as a microcomputer centering on the CPU 300, ROM 301, RAM 302, and EEPROM 303, and is connected to an ASIC (Application Specific Integrated Circuit) 306 via a bus 305.

  The CPU 300 is a central processing process that comprehensively controls the image recording apparatus 1, and executes various programs such as a program that executes the process shown in the flowchart of FIG. The ROM 301 is a non-rewritable memory that stores various control programs executed by the CPU 300 and data necessary for the CPU 300 to execute these control programs. Note that a program for executing the processing shown in the flowchart of FIG. 15 is stored in the ROM 301.

  The RAM 302 is a memory for temporarily storing data and programs necessary for various processes executed by the CPU 300. The RAM 302 includes a normal paper feed mode switching flag 302a. The normal paper feed mode switching flag 302a is a flag that is turned on when the number of sheets of paper P that can be printed with the remaining ink amount in the ink tank becomes one during printing in the continuous paper feed mode. . When the normal paper feed mode switching flag 302a is turned on, the continuous paper feed mode is changed to the normal paper feed mode during printing on the next paper P (that is, the last paper P that can be printed with the remaining ink amount). Switching to is performed.

  The EEPROM 13 is a rewritable nonvolatile memory, and includes a dot count memory 303a. The dot count memory 303a is a memory for storing the amount of ink used since the previous ink tank replacement as the number of printed dots. The value in the dot count memory 303a is reset to “0” when the ink tank is replaced. Each time printing is performed on one sheet of paper P, the number of dots printed for that single sheet P is added and the value is updated. The dot count memory 303a counts the number of dots for each color of the ink tank 26 (in this embodiment, every four colors of black, cyan, magenta, and yellow).

  A network control unit (NCU) 317 is connected to the ASIC 306, and a communication signal input from the public line via the NCU 317 is demodulated by the MODEM 318 and then input to the ASIC 306. When the ASIC 306 transmits image data to the outside by facsimile transmission or the like, the image data is modulated into a communication signal by the MODEM 318, and the communication signal is output to the public line via the NCU 317.

  The ASIC 306 generates, for example, a phase excitation signal for energizing the LF motor 42 in accordance with a command from the CPU 300, and supplies these signals to the drive circuit 311 of the LF motor 42 and the drive circuit 312 of the CR motor 24 for driving. A drive signal is supplied to the LF motor 42 and the CR motor 24 via the circuit 311 and the drive circuit 312 and the like, and the forward / reverse rotation and stop of the LF motor 42 and the CR motor 24 are controlled.

  Further, the ASIC 306 includes a scanner device 33 (for example, CIS) for reading a document image and characters, a panel interface 313 including a keyboard 30a of an operation panel 30 for transmission / reception operation and a liquid crystal display (LCD) 31. A parallel interface 315, a USB interface 316, and the like for transmitting / receiving data to / from an external device such as a personal computer via a parallel cable or a USB cable are connected.

  Further, the leaf switch 118 for detecting the rotational position of the cam (not shown) of the maintenance unit 36 and the paper P are fed to the ASIC 306 through the U-turn conveyance path 9 so as to approach the image recording unit. Sometimes, the rotation amount of the registration sensor 117 and the driving roller 20a provided in association with the paper detection body 116 located on the downstream side of the U-turn conveyance path 9 in order to detect the leading end position and the end position of the paper P is determined. A rotary encoder 44 for detection, a linear encoder 37 for detecting a movement amount and a movement position (current position) of the carriage 13 in the main scanning direction, and the like are connected.

  The drive circuit 314 is for selectively ejecting ink from the recording head 12 to the paper P at a predetermined timing. The drive circuit 314 generates a signal generated and output by the ASIC 306 based on a drive control procedure output from the CPU 300. In response, the recording head 12 is driven and controlled.

  Next, with reference to a flowchart of FIG. 15, control of paper feeding and image recording in the image recording apparatus 1 of the present embodiment will be described. FIG. 15 is a flowchart showing the continuous paper feed printing process. The continuous paper feed printing process is a process that is started when a user issues a print instruction in a state where the continuous paper feed mode is selected by pressing a mode setting button (not shown) on the operation panel 30.

  As shown in FIG. 15, first, the normal paper feed mode switching flag 302a is turned off (S2). Next, it is determined whether or not the remaining ink amount in the ink tank can be printed only on one page of paper P (S4). When a sufficient amount of ink remains in the ink tank and printing is possible on a plurality of sheets P with the remaining amount of ink (S4: No), the power transmission switching means 100 is set to the continuous paper feed mode ( S6). A case where the remaining amount of ink in the ink tank is small and only one sheet can be printed due to insufficient ink (S4: Yes) will be described later.

  With reference to FIG. 11, the setting of the continuous paper feed mode in the power transmission switching means 100 will be described. As shown in FIG. 11B, first, the carriage 13 is moved in the direction of arrow E. As a result, the contact piece 104 a is pushed by the first engagement step portion 13 a of the carriage 13. When the contact piece 104a is positioned at the second set portion 112 (Po2), the switching gear 102 and the continuous paper feed transmission gear 114 are engaged with each other to set the continuous paper feed mode. When the continuous paper feed mode is set, power is transmitted to the gear of the drive shaft 14 at the base end of the paper feed arm 6a via one intermediate gear 120 (see FIG. 13).

  When the LF motor 42 is rotated forward to start feeding the paper P in S10, the drive roller 20a and the switching gear 102 are rotated forward (see FIG. 13A), and the paper feed roller 7 is also fed. Rotate forward in the paper direction. Therefore, only the uppermost sheet P of the sheet feeding cassette 5 can be separated and fed to the U-turn conveyance path 9. Next, when the leading end of the paper P reaches the nip portion between the driving roller 20a and the driven roller 20b, the paper P is nipped by the nip portion and conveyed above the paper feed cassette 5 (FIG. 13B). Printing on the paper P is started (S12).

  In the printing process in S12, an image is printed by ejecting ink from the nozzles of the recording head 12 to the surface of the paper P while reciprocating the carriage 13 in the main scanning direction while the paper P is moved forward intermittently. Is done. As shown in FIG. 12C, when the continuous paper feed mode is set, when the paper P is transported in the transport direction by the forward rotation of the drive roller 20a, the paper feed roller 7 is rotated forward in the paper feed direction. To do. Therefore, in the printing process (S12), when the paper P sandwiched between the pair of registration rollers 20 is intermittently advanced, and the trailing edge of the paper P is removed from the feeding of the paper feed roller 7, the paper feed roller 7 starts feeding the succeeding paper P.

  Next, whether or not the trailing edge of the sheet P that is nipped by the registration roller pair 20 and intermittently advanced has reached a switching determination position that is a predetermined amount before the position where the nipping of the registration roller pair 20 is released is determined. A determination is made based on the carry amount detected by the encoder 44 (S14). The switching determination position will be described later in detail.

  If the trailing edge of the paper P has not yet been advanced to the switching determination position (S14: No), the printing process (S12) is repeated. On the other hand, when the trailing edge of the paper P is advanced to the switching determination position (S14: Yes), whether there is print data (next page) for the subsequent paper P (S16) and the normal paper feed mode switching. It is determined whether the flag 302a is turned on (S18).

  If there is a next page (S16: Yes) and the normal paper feed mode switching flag 302a is off (S18: No), the printing process is started again (S20). When printing for one page is completed, the printed paper P is discharged (S24). In that case, the LF motor 42 is rotated forward, and the drive roller 20a, paper discharge roller 21a, and paper feed roller 7 are rotated forward (see FIG. 13). As a result, the preceding sheet P (previous page) is discharged and the next sheet (following sheet) is conveyed to the print start position.

  Next, the number of dots printed on one discharged sheet P is added to the value of the dot count memory 303a (S26). Since the value of the dot count memory 303a is cleared at the time of ink tank replacement, thereafter, every time printing on one sheet P is completed, the number of dots used for printing is cumulatively added, so that the previous ink tank replacement is performed. The amount of ink used from the time can be counted. In this embodiment, the number of dots is cumulatively added for each color for each color of black, cyan, magenta, and yellow. The value of the dot count memory 303a corresponds to the “value relating to the remaining amount of ink in the ink tank” in the claims.

  Next, based on the value of the dot count memory 303a, it is determined whether or not there is one more printable sheet with the remaining amount of ink in the ink tank (S28). As described above, since the value of the dot count memory 303a corresponds to the ink usage amount from the previous ink tank replacement, the value of the dot count memory 303a (that is, the ink usage amount) is based on the predetermined value or more. Whether or not there is one more printable sheet with the remaining ink remaining amount, that is, one sheet P to be printed next is the last sheet P that can be printed with the remaining ink amount in the ink tank. It can be determined whether or not there is. As described above, in this embodiment, since the number of dots is counted for each color of black, cyan, magenta, and yellow, a predetermined value prepared in advance for each color and a value counted for each color And the number of printable sheets with the remaining amount of ink in the ink tank is determined to be one more based on the fact that the number of dots of any one color exceeds a predetermined value to be compared.

  If it is determined that there is sufficient ink remaining in the ink tank and printing is possible on a plurality of sheets of paper P (S28: No), the normal paper feed mode switching flag 302a is turned off (S32). On the other hand, if it is determined that there is one more printable sheet with the remaining amount of ink in the ink tank (S28: Yes), that is, the succeeding paper P that starts printing next is the ink in the ink tank. If it is determined that it is the last sheet P that can be printed with the remaining amount, the normal sheet feeding mode switching flag 302a is turned on (S30).

  As described above, the normal paper feed mode switching flag 302a is set according to whether or not the subsequent paper P to be printed next is the last paper P that can be printed with the remaining amount of ink in the ink tank. After (S30, S32), printing on the subsequent paper P is started (S12).

  Then, when it is determined that the trailing edge of the sheet P has reached the switching determination position a predetermined amount before the position where the pair of registration rollers 20 is unpinned (S14), and it is determined that there is a next page (S14). S16: Yes), it is determined whether or not the normal paper feed mode switching flag 302a is on (S18). Here, if the normal paper feed mode switching flag 302a is on (S18: Yes), that is, if the paper P being printed is the last paper P that can be printed with the remaining amount of ink in the ink tank, The transmission switching unit 100 switches the paper feed mode from the continuous paper feed mode to the normal paper feed mode (S34).

  With reference to FIG. 11, switching from the continuous paper feed mode to the normal paper feed mode will be described. First, the carriage is once moved to position P3 (Po3). Accordingly, the first block 104 that has been received by the second set unit 112 moves in the direction of arrow E and moves to position P3 (Po3). Next, the carriage 13 stopped at the position P3 (Po3) is largely moved in the direction of the arrow C and toward the printing area as shown in FIG. 11B. As a result, the first block 104 pushed by the urging spring 106 (see FIG. 10) moves in the direction of arrow C along the regulating piece 110 of the annular groove 109b, and when the carriage 13 is disengaged from the annular groove 109b, The position is received by the one set unit 111 (position P1 (Po1)). In this state, the switching gear 102 meshes with the paper feed side gear 113 and is connected so that power is transmitted to the gear of the drive shaft 14 of the feeding unit 6 via the intermediate gears 119a and 119b shown in FIG. is doing. In this state, when the LF motor 42 is rotated forward, the drive roller 20a of the registration roller pair 20 is rotated forward (clockwise rotation in FIG. 12B), and the paper feed roller 7 is in a direction opposite to the paper feed direction. Reverse rotation (clockwise rotation in FIG. 12B).

  Returning to FIG. When the paper feed mode is switched to the normal paper feed mode (S34), the normal paper feed mode switching flag 302a is then turned off (S36), and the printing process is resumed (S38). In this printing process, while the paper P is intermittently advanced by the forward rotation of the drive roller 20a, the paper feed roller 7 is rotationally driven in the direction opposite to the paper feed direction. Paper feeding of the paper P is suppressed. Therefore, even if the paper P is fed out from the paper feed cassette 5 before the paper feed mode is switched, if the paper feed mode is switched to the normal paper feed mode, the paper feed is performed while the preceding paper P is printed. The sheet is returned to the sheet feeding cassette 5 by the sheet feeding roller 7 that is reversed in the opposite direction.

  In this embodiment, switching from the continuous paper feed mode to the normal paper feed mode is during printing of the last paper P that can be printed with the remaining amount of ink in the ink tank, and the trailing edge of the paper P This is performed when the switching determination position is reached a predetermined amount before the position where the pair of rollers 20 is unpinned. Here, the switching determination position is a position where the leading edge of the succeeding paper P has not yet reached the paper detection body 116 when the trailing edge of the paper P sandwiched between the registration roller pair 20 has reached the switching determination position. As a predetermined position. Therefore, by switching the paper feeding mode at the timing when the trailing edge of the paper P being printed reaches the switching determination position, the paper feeding mode is changed before the leading edge of the succeeding paper P reaches the paper detector 116. It is possible to switch to the normal paper feed mode. After the paper feed mode is switched, the paper feed roller 7 is driven to rotate in the direction opposite to the paper feed direction while the preceding paper P is moved forward intermittently, so that it is fed to the U-turn conveyance path 9. The paper P is conveyed in the direction opposite to the paper feeding direction, and the paper P can be reliably returned to the accumulation position of the paper feeding cassette 5.

  In contrast, when the continuous paper feed mode is switched to the normal paper feed mode after the leading edge of the succeeding paper P passes through the paper detector 116, the paper detector 116 comes into contact with the paper P, and the paper Since a load is applied to P, when the frictional force and torque of the paper feed roller 7 are small, there is a possibility that the paper P cannot be returned to the paper feed cassette 5 by the reverse rotation of the paper feed roller 7. In particular, the frictional force and torque of the paper feed roller 7 are kept relatively small in order to prevent the paper P at the accumulation position in the paper feed cassette 5 from being bent by the reverse rotation of the paper feed roller 7. For this reason, if the load applied to the paper P increases even slightly, there is a possibility that the paper P cannot be reversely fed by the reverse rotation of the paper feed roller 7.

  Then, the printing process is continued (S38), and when printing of one page on the paper P is completed, the printed paper P is discharged (S40). In that case, in order to continuously rotate the registration roller pair 20 and the discharge roller pair 21 continuously in the forward direction, the LF motor 42 is rotated forward in appropriate steps (S40). Since the paper feed roller 7 is rotationally driven in the direction opposite to the paper feed direction by the normal rotation of the LF motor 42, the suppression of paper feed of the subsequent paper is continued. Then, after the printed paper P is discharged, the LF motor 42 is stopped (S41). Thereby, the rotation of the drive roller 20a and the paper feed roller 7 is stopped.

  In this way, when the paper feed mode is switched during printing of the last paper P that can be printed with the remaining amount of ink in the ink tank, the feeding of the subsequent paper P to the U-turn conveyance path 9 is suppressed thereafter. Therefore, the paper P that cannot be printed due to the remaining amount of ink in the ink tank is suppressed from being fed to the U-turn conveyance path 9. After the printing on the last paper P that can be printed with the remaining amount of ink in the ink tank, the rotation of the drive roller 20a and the paper feed roller 7 is stopped. It can suppress remaining in the turn conveyance path 9.

  Next, the type of ink tank whose ink remaining amount is insufficient is displayed on the display unit 31 (see FIG. 1), and the user is notified that it is time to replace the ink tank (S42). The display is continued until the ink tank with insufficient ink remaining is replaced by the user (S44).

  When the user replaces the ink tank (S44: Yes), a purge process is executed (S46). As shown in FIG. 11, when the purge process is executed, the carriage 13 is moved to the position P3 (Po3), and the switching gear 102 is engaged with the maintenance transmission gear 115. When the LF motor 42 is driven in this state, a suction pump (not shown) is operated to suck ink from the nozzles. As a result, it is possible to remove bubbles that have entered during ink tank replacement. When the LF motor 42 is driven for the purge process, the vibration may be transmitted to the registration roller pair 20 via the power transmission switching means 100 (see FIG. 10). However, as described above, when the ink tank is replaced. Since the paper P does not remain in the U-turn conveyance path 9, the positional deviation of the paper P due to the vibration of the registration roller pair 20 does not occur. On the other hand, when the ink tank is replaced, the paper P remains in the U-turn conveyance path 9, and particularly when the leading end of the paper P is in contact with or sandwiched by the registration roller pair 20, Due to the vibration of the registration roller pair 20 during the purge process, a positional shift occurs and the recording head 12 is not conveyed to an accurate position, so that the image quality deteriorates.

  Returning to FIG. After the purge process, it is determined whether there is print data (next page) for the next sheet P (S48). If there is no next page (S48: No), the process is terminated. On the other hand, if there is a next page (S48: Yes), the process returns to S6, the continuous paper feed mode is set (S6), and the process is repeated. In this way, after the ink tank is replaced, printing in the continuous paper feed mode is automatically resumed, so that an operation burden on the user is suppressed.

  Next, a case will be described in which printing of all pages of input print data is completed without the ink remaining in the ink tank being insufficient. Even in such a case, it is not desirable that the paper P remains in the U-turn conveyance path 9 at the end of printing of all pages. Therefore, during printing of the last page, the paper feed mode is changed from the continuous paper feed mode to the normal paper feed mode. Switch to mode.

  Specifically, printing is performed (S12), and when the trailing edge of the paper P reaches the switching determination position (S14), it is determined whether there is a next page (S16). If there is no next page (S16: No), the continuous paper feed mode is switched to the normal paper feed mode (S50), and the normal paper feed mode switching flag 302a is turned off (S52). As described above, by switching the paper feed mode at the timing when the trailing edge of the paper P being printed has reached the switching determination position, the paper is fed before the leading edge of the subsequent paper P reaches the paper detector 116. The paper mode can be switched to the normal paper feed mode.

  After the paper feed mode is switched, the printing process for the paper P being printed is resumed (S53). At this time, the paper feed roller 7 is rotationally driven in the direction opposite to the paper feed direction while the paper P being printed is intermittently advanced, so that the paper P fed to the U-turn conveyance path 9 is moved in the paper feed direction. The sheet is conveyed in the reverse direction and reliably returned to the accumulation position of the sheet feeding cassette 5.

  When printing on the paper P is completed, the printed paper P begins to be discharged (S54). In that case, the LF motor 42 is rotated forward by an appropriate number of steps so as to continuously rotate the registration roller pair 20 and the paper discharge roller pair 21 continuously, and then the LF motor 42 is stopped (S56), and the process is terminated. As described above, while printing is performed on the last paper P, feeding of the subsequent paper P is suppressed, so that the paper P is prevented from remaining in the U-turn conveyance path 9 after the printing is completed. .

  Next, a case where the remaining amount of ink in the ink tank has already been small at the start of the continuous paper feed printing process will be described. In that case, in the process of S4, it is determined that only one more sheet can be printed with the remaining amount of ink in the ink tank (S4: Yes), and the normal paper feed mode switching flag 302a is turned on (S8).

  Then, the first sheet P is fed (S10), and printing is performed on the sheet P (S12). When the trailing edge of the paper P reaches the switching determination position (S14), since the normal paper feed mode switching flag 302a is on (S18: Yes), the continuous paper feed mode is switched to the normal paper feed mode (S34). Thereafter, the processing from S36 described above is executed. Therefore, even when the remaining amount of ink in the ink tank is already small at the start of the continuous paper feed printing process, the paper P is suppressed from remaining in the U-turn conveyance path 9.

  The present invention has been described above based on the embodiments. However, the present invention is not limited to the above-described embodiments, and various improvements and modifications can be easily made without departing from the spirit of the present invention. Can be inferred.

  For example, in this embodiment, the continuous paper supply mode is switched to the normal paper supply mode before the leading edge of the succeeding paper P comes into contact with the paper detection body 116. Even after contact with the detection body 116, if the paper P can be reversely fed to the paper feed cassette 5 by the reverse rotation of the paper feed roller 7, the leading edge of the subsequent paper P moves to the paper detection body 116. After the contact, the continuous paper feed mode may be switched to the normal paper feed mode. However, even in this case, it is desirable that the continuous paper supply mode is switched to the normal paper supply mode before the leading edge of the succeeding paper P is sandwiched between the registration roller pairs 20a and 20b. . This is because if the leading edge of the succeeding paper P is sandwiched between the registration roller pairs 20a and 20b, the paper P may not be fed back to the paper feed cassette 5 by the reverse rotation of the paper feed roller 7.

1 is an overall perspective view of an image recording apparatus. It is the perspective view which looked at the main body case from the back except for the upper case. FIG. 3 is a top view of FIG. 2. FIG. 4 is a side cross-sectional view of a main part in a state where a paper feed cassette is attached to the recording unit. It is a principal part expanded side sectional view of only an image recording part. It is a side view of a paper feed cassette and a paper feed unit. FIG. 4 is a partially cutaway plan view of a state where a paper feed cassette is attached to the recording unit. FIG. 6 is a perspective view of the recording unit in a state where a downstream guide plate and a platen are removed. It is the IX-IX line arrow expanded sectional view of FIG. It is a schematic diagram of a power transmission switching means. (A) is a front view (b) which shows the switching state to each mode by a power transmission switching means. (A) is a figure which shows the power transmission in the paper feeding state in a normal paper feeding mode, (b) is a figure which shows the power transmission at the time of image recording. (A) is a diagram showing power transmission in the paper feeding state in the continuous paper feeding mode, (b) is a diagram showing power transmission during image recording, and (c) is a power transmission during feeding of the subsequent paper P. FIG. It is a functional block diagram of a control device. 6 is a flowchart illustrating continuous paper feed printing processing.

Explanation of symbols

1 Image recording device (inkjet printer)
5 Paper cassette 7 Paper feed roller (part of transport means)
9 U-turn conveyance path (conveyance path)
12 Recording head (printing head)
20 Registration roller pair (clamping means)
20a Drive roller (part of the conveying means)
21a Paper discharge roller (part of transport means)
26 Ink tank 36 Maintenance section (maintenance means)
42 LF motor (drive motor)
100 Power transmission switching means 116 Paper detection body (part of paper detection means)
117 Registration sensor (part of paper detection means)
P paper (recording medium)
S26 Ink remaining amount acquisition means S34 Switching control means S41 Conveyance stop means S44 Ink tank replacement determination

Claims (3)

A print head having an ink discharge port for discharging ink supplied from an ink tank and capable of printing an image on a recording medium;
Maintenance means for performing maintenance for sucking ink from the ink discharge port of the print head;
Ink tank replacement determination means for determining whether the ink tank has been replaced;
The recording media accumulated in the paper feed cassette are fed one by one to the transport path, transported to the image recording unit where printing by the print head is performed, and after the printing by the print head is finished, the recording medium is discharged. Conveying means for
In an ink jet printer comprising: an ink tank remaining amount acquisition unit that acquires a value relating to the ink remaining amount in the ink tank;
The transport means includes a pair of sandwiching means for sandwiching the recording medium transported via the transport path upstream of the image recording unit in the transport direction,
In the transport path, while running the continuous sheet feeding mode for operating the conveying means so feeding of the conveyance path of the subsequent recording medium during printing of a recording medium conveyed above is started, the subsequent Whether the recording medium can be printed based on the value relating to the remaining ink amount acquired by the remaining ink amount acquiring means ,
If it is determined that the succeeding recording medium cannot be printed, the succeeding recording is performed during the recording on the previously transported recording medium before the succeeding recording medium is sandwiched by the sandwiching means. Switching to a normal paper feed mode in which the transport means is operated to suppress the paper feed to the transport path;
After completion of printing on the previously conveyed recording medium, the conveyance by the conveyance unit is stopped, and when the ink tank replacement unit determines that the ink tank has been replaced, the maintenance unit performs maintenance,
An ink jet printer characterized in that the maintenance means and the transport means use the same drive motor as a drive source. The transport means includes a paper feed roller that feeds the recording medium deposited in the paper feed cassette to the transport path one by one, and a drive roller that transports the recording medium being printed by the print head in the transport direction. ,
When the normal paper feeding mode is selected, when the recording medium being printed is transported in the transport direction by forward rotation of the drive roller, the paper feed roller is rotationally driven in a direction opposite to the paper feed direction , The inkjet printer according to claim 1, wherein feeding of a subsequent recording medium to the conveyance path is suppressed . The inkjet printer according to claim 2, wherein the clamping unit includes the drive roller.

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