JP7103735B2 - Image recorder - Google Patents

Description

The present invention relates to an image recording apparatus including an inkjet head.

Conventionally, an ink pan is inserted between an inkjet head that records an image on a recording medium and a transport mechanism that is arranged below the inkjet and conveys the recording medium, and the ink ejected from the inkjet head during the purge process is ejected. An image recording device that receives an ink pan has been proposed (see, for example, Patent Documents 1 and 2).

In such an image recording device, for example, when the image recording process is performed, the transport mechanism is lifted so as to approach the inkjet head, and when the purge process is performed, the transport mechanism is lifted so as to be separated from the inkjet head. Can be lowered. Then, the ink pan is retracted to the storage position when the image recording process is performed, and is inserted between the inkjet and the transport mechanism during the purge process as described above. The ink received by the ink pan is tilted when the ink pan is retracted to the storage position, so that the ink flows into the waste liquid tank through the waste liquid pipe connected to the discharge port of the ink pan and is stored in the waste liquid tank.

Japanese Unexamined Patent Publication No. 2013-203065 Japanese Unexamined Patent Publication No. 2012-20523

However, when the ink pan is retracted to the storage position as described above with a large amount of waste liquid accumulated in the ink pan at the time of initial ink filling or maintenance (particularly maintenance with a large amount of waste liquid), the ink is discharged from the discharge port to the waste liquid pipe. It flows into at once.

The air in the waste liquid pipe travels to the ink pan discharge port in the opposite direction to the ink and is discharged into the atmosphere. Especially when the ink flows into the waste liquid pipe at once as described above, the ink pan discharge port is affected by the ink. It becomes covered (blocked), air bubbles released may burst, and ink covering the discharge port may scatter. Such ink scattering is likely to occur when the amount of ink covering the discharge port is small, especially in the last case where the ink flows out from the discharge port.

When the ink scatters and adheres to the transfer roller in the image recording device, the ink also adheres to the recording medium conveyed by the transfer roller. Further, if the ink scatters and adheres to the terminals of the sensor or the like, the sensor or the like may be damaged.

In addition, in order to suppress ink scattering, the ink pan is moved with a waiting time while moving from the position where the ink is received from the inkjet head to the storage position, or the ink pan is slowly moved to the storage position. By doing so, it is conceivable to prevent the ink from covering the discharge port of the ink pan.

However, if it takes time to move the ink pan in this way, the transport mechanism cannot be lifted and brought close to the inkjet head until the ink pan is retracted to the storage position. Therefore, the recording medium cannot be conveyed by the conveying mechanism, which causes a problem that the restart of the image recording operation is delayed.

Further, when a configuration is adopted in which pressure is applied to the waste liquid pipe to forcibly send the ink in the waste liquid pipe to the waste liquid tank in order to suppress the scattering of ink, the structure of the image recording device becomes complicated.

An object of the present invention is to provide an image recording apparatus capable of suppressing scattering of ink in an ink pan ejected from an inkjet head without delaying the restart of an image recording operation and with a simple configuration.

In one embodiment, the image recording apparatus includes an inkjet head that records an image on a recording medium by ejecting ink, a first position for receiving waste ink ejected from the inkjet head, and the first position. An ink pan that can be moved from the position of The waste liquid pipe is provided with a waste liquid pipe to be sent to the waste liquid pipe, and has an air vent portion for letting air in the waste liquid pipe escape.

According to the above aspect, the scattering of ink in the ink pan ejected from the inkjet head can be suppressed without delaying the restart of the image recording operation and with a simple configuration.

It is a block diagram which shows the image recording apparatus. It is explanatory drawing for demonstrating the 1st position of an ink pan. It is a top view which shows the ink pan in a 1st position. FIG. 3 is a sectional view taken along line IV-IV of FIG. It is a right side view which shows the waste liquid recovery device (the ink pan is a 1st position). It is a right side view which shows the waste liquid recovery device (the ink pan is a 2nd position). It is a right side view which shows the waste liquid recovery device (ink pan is a 2nd position) in the modification.

Hereinafter, the image recording apparatus according to the embodiment of the present invention will be described with reference to the drawings.

FIG. 1 is a configuration diagram showing an image recording device 1.
In the following description, the vertical and horizontal directions of the paper surface in FIG. 1 are defined as the vertical and horizontal directions, and the direction orthogonal to the paper surface of FIG. 1 is defined as the front-rear direction. In addition, upstream and downstream in the following description mean upstream and downstream in the transport path.

In FIG. 1, the transport path for transporting the paper S, which is an example of the recording medium, is shown by a thick line. Of the transport routes, the print route (image recording) RP is indicated by a solid line, the circulation route RC is indicated by a dashed line, the first paper discharge route RD1 and the second paper discharge route RD2 are indicated by broken lines, and the external paper feed route is shown. RS1 and the internal paper feed path RS2 are indicated by alternate long and short dash lines. The recording medium is not limited to the paper S, and may be a recording medium made of a material other than paper, a recording medium having a folded portion such as an envelope, or the like.

As shown in FIGS. 1 and 2, the image recording device 1 includes a housing 2, a paper feeding unit 3, a belt platen transport unit 4, an image recording unit 5, a circulation transport unit 6, and a paper discharge unit 7. The operation panel 15, the control unit 16, and the waste liquid recovery device 10 are provided. The paper feed unit 3, the belt platen transfer unit 4, the circulation transfer unit 6, and the paper discharge unit 7 function as an example of a transfer unit that conveys the paper S (recording medium).

The housing 2 accommodates or holds each part of the image recording device 1. The housing 2 has a front door 17 shown by a broken line. The front door 17 opens and closes the front surface of the housing 2. By opening the front door 17, the user can access the inside of the image recording device 1.

The paper feed unit 3 feeds unprinted paper S, that is, paper S on which no image recording has been performed, to the belt platen transport unit 4. Further, the paper feed unit 3 refeeds the paper S after single-sided printing to the belt platen transport unit 4 at the time of double-sided printing. The paper feed unit 3 includes an external paper feed tray 21, an external paper feed roller 22, first and second internal paper feed trays 23 and 24, first and second internal paper feed rollers 25 and 26, and first. It has a third internal paper feed transfer roller pair 29 to 31, a vertical transfer roller pair 33, a resist roller pair 35, and a paper sensor 37 to 40.

Paper S used for printing is loaded on the external paper feed tray 21. A part of the external paper feed tray 21 is exposed to the outside of the housing 2.

The external paper feed roller 22 feeds out the paper S stacked on the external paper feed table 21 one by one and conveys the paper S along the external paper feed path RS1 toward the resist roller pair 35.

Paper S used for printing is loaded on the first and second internal paper feed trays 23 and 24. The second internal paper feed tray 24 is arranged below the first internal paper feed tray 23. The first and second internal paper feed trays 23 and 24 are arranged inside the housing 2.

The first internal paper feed roller 25 feeds out the paper S stacked on the first internal paper feed table 23 one by one and conveys the paper S to the first internal paper feed transfer roller pair 29. The second internal paper feed roller 26 feeds out the paper S stacked on the second internal paper feed table 24 one by one and conveys it to the second internal paper feed transfer roller pair 30.

The first internal paper feed transfer roller pair 29 and the second internal paper feed transfer roller pair 30 are respectively provided by the first internal paper feed roller 25 or the second internal paper feed roller 26 to form the first internal paper feed table 23 or the second internal paper feed roller 26. The paper S fed from the paper base 24 is conveyed to the third internal paper feed transfer roller pair 31. The third internal paper feed transfer roller pair 31 conveys the paper S conveyed by the first internal paper feed transfer roller pair 29 or the second internal paper feed transfer roller pair 30 to the vertical transfer roller pair 33. The third internal paper feed transfer roller pair 31 is arranged near the downstream side of the confluence of the portion extending from the first internal paper feed roller 25 and the portion extending from the second internal paper feed roller 26 of the internal paper feed path RS2. There is.

The first internal paper feed transport roller pair 29, the second internal paper feed transport roller pair 30, and the third internal paper feed transport roller pair 31 carry the paper S while niping it.

The vertical transfer roller pair 33 conveys the paper S conveyed by the first to third internal feed transfer rollers pairs 29 to 31 along the internal paper feed path RS2 to the resist roller pair 35. Further, the vertical transfer roller pair 33 transfers the single-sided printed paper S conveyed along the circulation path RC during double-sided printing to the resist roller pair 35. The vertical transport roller pair 33 is arranged along the internal paper feed path RS2 on the downstream side of the point where the circulation path RC joins the internal paper feed path RS2. The vertical transport roller pair 33 transports the paper S while niping it.

The resist roller pair 35 temporarily stops the paper S transported by the external paper feed roller 22 or the vertical transport roller pair 33, corrects the skew, and then transports the paper S to the belt platen transport unit 4. The resist roller pair 35 is arranged on the print path RP near the downstream side of the confluence of the external paper feed path RS1 and the internal paper feed path RS2. The resist roller pair 35 conveys the paper S while niping it.

The paper sensor 37 detects the paper S that is fed out from the first internal paper feed tray 23 and transported to the third internal paper feed transport roller pair 31. The paper sensor 37 is arranged near the downstream side of the first internal paper feed transfer roller pair 29. The paper sensor 38 detects the paper S that is fed from the second internal paper feed tray 24 and is fed to the third internal paper feed transport roller pair 31. The paper sensor 38 is arranged near the downstream side of the second internal paper feed transfer roller pair 30. The paper sensor 39 detects the paper S transported from the third internal paper feed transport roller pair 31 to the vertical transport roller pair 33. The paper sensor 39 is arranged near the downstream side of the third internal paper feed transfer roller pair 31.

The paper sensor 40 detects the paper S transported from the vertical transport roller pair 33 to the resist roller pair 35. The paper sensor 40 is arranged near the downstream side of the vertical transport roller pair 33. The paper sensor 41 detects the paper S that is conveyed by the external paper feed roller 22 or the vertical transfer roller pair 33 and enters the resist roller pair 35. The paper sensor 41 is arranged near the upstream side of the resist roller pair 35.

The belt platen transport unit 4 conveys the paper S conveyed from the paper feed unit 3 to the circulation transfer unit 6 or the paper discharge unit 7. The belt platen transport unit 4 is arranged on the downstream side of the paper feed unit 3. The belt platen transport unit 4 has a belt platen 46 and a paper sensor 48.

The belt platen 46 sucks and holds the paper S conveyed by the resist roller pair 35 on the belt and conveys the paper S. The belt platen 46 can be raised and lowered by an elevating drive unit 52, which will be described later.

The paper sensor 48 detects the paper S conveyed from the resist roller pair 35 to the belt platen 46. The paper sensor 48 is arranged between the resist roller pair 35 and the upstream end of the belt platen 46.

The image recording unit 5 records (prints) an image on the paper S.
The image recording unit 5 is arranged above the belt platen 46. The image recording unit 5 includes a head unit 51 and an elevating drive unit 52.

The head unit 51 has a plurality of inkjet heads 53 and a head holder 54.

The inkjet head 53 has a plurality of nozzles arranged along the front-rear direction (main scanning direction), and ejects ink from the nozzles to record an image on the paper S. The plurality of inkjet heads 53 are arranged in parallel along the transport direction (left-right direction) of the paper S.

The head holder 54 holds the inkjet head 53. The head holder 54 is fixed at a predetermined position in the housing 2.

The elevating drive unit 52 raises and lowers the belt platen 46. The elevating drive unit 52 is arranged in the head holder 54. The elevating drive unit 52 has a wire, a pulley, a motor, and the like, and suspends and supports the belt platen 46 by the wire. The elevating drive unit 52 raises and lowers the belt platen 46 by rotating the pulley with a motor to wind and unwind the wire. During the purging process, the elevating drive unit 52 lowers the belt platen 46 as shown in FIG. 2, and the ink pan 11 is interposed between the inkjet head 53 and the belt platen 46 (belt platen transport unit 4). Secure space to do.

At the time of double-sided printing, the circulation transport unit 6 transports the paper S after single-sided printing from the downstream end of the belt platen 46 to the vertical transport roller pair 33 along the circulation path RC. The circulation transfer unit 6 includes first and second intermediate transfer rollers 56, 57, switchback rollers 59, first to third horizontal transfer rollers 61 to 63, ascending transfer rollers 65, and a paper sensor. It has 67 to 70.

The first and second intermediate transfer rollers 56 and 57 convey the paper S after surface printing to the switchback roller pair 59 during double-sided printing. The first and second intermediate transfer rollers 56, 57 are arranged along the circulation path RC between the belt platen 46 and the switchback roller pair 59.

The first intermediate transfer roller pair 56 is composed of a pair of rollers 56a and 56b, and conveys the paper S while niping it. The second intermediate transfer roller pair 57 is composed of a pair of rollers 57a and 57b, and conveys the paper S while niping it. The second intermediate transfer roller pair 57 is arranged on the downstream side of the first intermediate transfer roller pair 56.

The switchback roller pair 59 is arranged on the downstream side of the second intermediate transfer roller pair 57 along the circulation path RC. The switchback roller pair 59 conveys the paper S while niping it.

The switchback roller pair 59 switches back the paper S transported by the second intermediate transport roller pair 57 in the switchback path of the circulation path RC, and transports the paper S to the first horizontal transport roller pair 61.

The first to third horizontal transfer rollers 61 to 63 transfer the paper S switched back by the switchback roller pair 59 to the ascending transfer roller pair 65. The first to third horizontal transfer rollers 61 to 63 are arranged along the upstream portion of the circulation path RC between the switchback roller pair 59 and the confluence point of the circulation path RC with the internal paper feed path RS2. ..

The first horizontal transfer roller pair 61, the second horizontal transfer roller pair 62, and the third horizontal transfer roller pair 63 convey the paper S while niping it. The second horizontal transfer roller pair 62 is arranged on the downstream side of the first horizontal transfer roller pair 61. The third horizontal transfer roller pair 63 is arranged on the downstream side of the second horizontal transfer roller pair 62.

The ascending transfer roller pair 65 conveys the paper S conveyed by the first to third horizontal transfer rollers pairs 61 to 63 to the vertical transfer roller pair 33. The ascending transfer roller pair 65 is arranged along the downstream portion of the circulation path RC between the switchback roller pair 59 and the confluence point of the circulation path RC with the internal paper feed path RS2. The ascending transfer roller pair 65 conveys the paper S while niping it.

The paper sensors 67 and 68 detect the paper S transported to the switchback roller pair 59 by the first and second intermediate transport roller pairs 56 and 57. The paper sensors 67 and 68 are arranged in the vicinity of the downstream side of the first intermediate transfer roller pair 56 and the second intermediate transfer roller pair 57, respectively. The paper sensors 68 and 69 detect the paper S to be conveyed to the vertical transfer roller pair 33 along the circulation path RC after the switchback by the switchback roller pair 59. The paper sensors 68 and 69 are arranged in the vicinity of the downstream side of the first horizontal transfer roller pair 61 and the ascending transfer roller pair 65, respectively.

The paper ejection unit 7 ejects the printed paper S. The paper ejection units 7 include switching portions 71 and 72, first and second post-processing paper ejection rollers pairs 75 and 76, first to third paper ejection base paper ejection rollers pairs 78 to 80, and paper sensors 82 to. It has 85 and a paper ejection table 86.

The switching unit 71 switches the transport path of the paper S between the first paper discharge path RD1 and the circulation path RC. The first paper discharge path RD1 is a path extending from the downstream end of the print path RP toward the post-processing device (not shown) arranged on the right side of the image recording device 1. The switching unit 71 is arranged at a branch point between the first paper discharge path RD1 and the circulation path RC.

The switching unit 72 switches the transport path of the paper S between the first paper discharge path RD1 and the second paper discharge path RD2. The second paper ejection route RD2 is a route that branches from the first paper ejection route RD1 and heads for the paper ejection table 86 on the downstream side of the branch point between the first paper ejection route RD1 and the circulation path RC. The switching unit 72 is arranged at a branch point where the second paper discharge path RD2 branches from the first paper discharge path RD1.

The first and second post-treatment paper ejection rollers pairs 75 and 76 discharge the paper S conveyed from the belt platen 46 to the post-processing apparatus. The first and second post-treatment paper ejection rollers pairs 75 and 76 are arranged along the first paper ejection path RD1.

The first post-treatment paper discharge roller pair 75 and the second post-treatment paper discharge roller pair 76 convey the paper S while niping it. The second post-treatment paper ejection roller pair 76 is arranged on the downstream side of the first post-treatment paper ejection roller pair 75.

The first to third paper ejection stands, the paper ejection rollers pairs 78 to 80, eject the paper S conveyed from the belt platen 46 to the paper ejection table 86. The first to third paper ejection tables, paper ejection rollers, pairs 78 to 80, are arranged along the second paper ejection path RD2.

The first paper ejection board output roller pair 78, the second paper ejection board output roller pair 79, and the third paper ejection board output roller pair 80 convey the paper S while niping it. The second paper ejection board output roller pair 79 is arranged on the downstream side of the first paper ejection board output roller pair 78. The third paper ejection board output roller pair 80 is arranged on the downstream side of the second paper ejection board output roller pair 79.

The paper sensor 82 detects the paper S conveyed along the first paper discharge path RD1. The paper sensor 82 is arranged near the downstream side of the first post-processing paper ejection roller pair 75. The paper sensors 83 to 85 detect the paper S conveyed along the second paper discharge path RD2. The paper sensor 83 is arranged between the branch point of the second output path RD2 from the first output path RD1 and the first output stand output roller pair 78. The paper sensor 84 is arranged near the downstream side of the second paper discharge table paper discharge roller pair 79. The paper sensor 85 is arranged near the upstream side of the third paper ejection table paper ejection roller pair 80.

The paper S discharged by the first to third paper ejection tables ejecting rollers pairs 78 to 80 is loaded on the paper ejection table 86. The output table 86 is arranged at the downstream end of the second output path RD2.

The operation panel 15 functions as a display unit by displaying various input screens and the like, and also functions as an input unit by having an operation key for receiving an input operation by the user. When the operation panel 15 has a display with a touch panel, the display functions as an input unit and a display unit.

The control unit 16 has a processor (for example, a CPU: Central Processing Unit) that functions as an arithmetic processing unit, and a storage unit such as a ROM (Read Only Memory) and a RAM (Random Access Memory). Control the operation.

The waste liquid recovery device 10 shown in FIGS. 1, 5 and 6 includes an ink pan 11, a waste liquid tank 12, and a waste liquid pipe 13.

The ink pan 11 has a first position P1 (see FIGS. 2, 3, and 5) that receives the ink IK that becomes waste liquid discharged from the inkjet head 53 during a purging process or the like by the inkjet head 53. It is possible to move to a second position P2 (see FIGS. 1 and 6), which is a storage position retracted from the first position P1. The ink pan 11 moves to the first position P1 and the second position P2 by driving an ink pan driving device having a motor (actuator) or the like (not shown).

As shown in FIG. 3, the ink pan 11 has an ink pan main body 11a and an discharge port 11b.

The upper surface of the ink pan body 11a is centered in the front-rear direction and right side so that the ink IK ejected from the inkjet head 53 is poured into the discharge port 11b provided at the center in the front-rear direction and at the right end of the ink pan body 11a. It is inclined or curved downward toward.

The discharge port 11b projects to the right from the ink pan main body 11a and bends forward from the middle.
As shown in FIG. 4 (the IV-IV cross-sectional view of FIG. 3), the discharge port 11b is provided with a partition wall 11c for forming an air bleeding path communicating with the air bleeding path 13a of the waste liquid pipe 13.

The partition wall 11c is provided at the right end of the ink pan 11 so that the air A escaped from the air vent path 13a of the waste liquid pipe 13 is discharged upward from the root portion of the discharge port 11b on the ink pan body 11a side. ing. The partition wall 11c may have a semi-cylindrical shape, for example, extend horizontally in the discharge port 11b, and bend so as to rise at a right angle at the root portion of the discharge port 11b.

The upper end of the partition wall 11c is higher than the upper end of the ink pan main body 11a by a height h. In this way, even if the partition wall 11c is tilted when the ink pan 11 moves from the first position P1 to the second position P2, the ink IK in the ink pan main body 11a enters the path through which the air A escapes. It is desirable that the height and angle are such that they can be prevented.

The waste liquid tank 12 is arranged in the housing 2 of the image recording device 1 shown in FIG. 1 and stores the ink IK received by the ink pan 11.

As shown in FIGS. 5 and 6, the waste liquid pipe 13 sends the ink IK received by the ink pan 11 to the waste liquid pipe 13 through the discharge port 11b of the ink pan 11, so that the discharge port 11b of the ink pan 11 and the waste liquid tank A pipe (eg, a tube, a hose, a pipe) connected to the inflow port 12a of the twelve. An example of routing the waste liquid pipe 13 when the ink pan 11 is at the second position P2 differs between FIGS. 1 and 6, but the routing of FIG. 6 will be described below as an example.

The waste liquid pipe 13 is provided with an air bleeding path 13a (shown by a broken line), which is an example of an air bleeding portion that allows air A in the waste liquid pipe 13 to escape with the inflow of ink IK from the ink pan 11 into the waste liquid pipe 13. ..

The air vent path 13a is connected to the discharge port 11b of the ink pan 11 discharge port 11b so as to communicate only with the air vent path partitioned by the partition wall 11c and not to communicate with the ink IK discharge port. It is good.

The air vent path 13a may be a waste pipe 13 in which the inside is divided by a partition wall, or a separate pipe (for example, a tube, a hose, a pipe) is inserted in the waste pipe 13. It may be. Further, the air vent path 13a may be a pipe (for example, a tube, a hose, a pipe) connected in the middle of the waste liquid pipe 13 in the length direction so as to extend from the inside of the waste liquid pipe 13 to the outside of the waste liquid pipe 13. .. Further, the air bleeding portion using the air bleeding path 13a as an example may be a portion provided in a part of the waste liquid pipe 13 and made of a material that discharges air A from the waste liquid pipe 13 but does not discharge ink IK.

Here, as shown in FIG. 6, when the ink pan 11 is at least at the second position P2, the waste liquid tank 12 closes the waste liquid pipe 13 by bending downward from the ink pan 11 toward the waste liquid tank 12. A effluent pool is formed. As shown in FIG. 6, this waste liquid pool closes the waste liquid pipe 13 below the horizontal virtual plane V1 passing through the lower end of the inflow port 12a of the waste liquid tank 12.

Alternatively, as in the waste liquid pipe 13-1 of the waste liquid recovery device 10-1 in the modified example shown in FIG. 7, the waste liquid pipe 13-1 is moved from the ink pan 11 to the waste liquid tank 12 above the inflow port 12a of the waste liquid tank 12. By curving downward toward, in this curved portion, the waste liquid that closes the waste liquid pipe 13 below the horizontal virtual plane V2 that passes through the inner bottom surface of the bent apex (curved apex) 13b of the portion that curves downward thereafter. A puddle is formed.

Therefore, it is preferable that the air vent path 13a is provided between the discharge port 11b of the ink pan 11 and the above-mentioned waste liquid pool. As a result, when the ink pan 11 is retracted from the first position P1 to the second position P2 as described above, the amount of ink IK flowing from the ink pan 11 to the waste liquid pipe 13 increases and the ink IK is discharged. Even if the outlet 11b is covered, the air A in the waste liquid pipe 13 can be more reliably released from the air vent path 13a.

Hereinafter, the operation of the image recording process in the image recording device 1 will be described.
When a print job is input, the control unit 16 controls the paper feed unit 3, the belt platen transfer unit 4, the circulation transfer unit 6, and the paper discharge unit 7 so as to feed, convey, and eject the paper S. .. Further, the control unit 16 performs predetermined image processing on the image data included in the print job, and then ejects ink IK onto the paper S conveyed by the belt platen 46 based on the image data subjected to the image processing. The inkjet head 53 of the head unit 51 is controlled so as to record an image.

Here, in the case of single-sided printing, unprinted paper S is sequentially fed from any of the external paper feed tray 21, the first and second internal paper feed trays 23, 24 in the paper feed unit 3, and the belt platen 46 Paper is sequentially fed at a timing such that each paper S is conveyed between predetermined papers. The fed paper S is conveyed by the belt platen 46 at a predetermined printing transfer speed, and image recording is performed by the ink IK ejected from the inkjet head 53. The printed paper S is discharged by the paper ejection unit 7.

When the output destination is a post-processing device, the printed paper S is guided to the first output path RD1 by the switching units 71 and 72. Then, the paper S is discharged to the post-processing apparatus by the first and second post-processing paper ejection rollers pairs 75 and 76. When the output destination is the output table 86, the printed paper S is guided to the second output path RD2 by the switching units 71 and 72. Then, the paper S is ejected to the output table 86 by the first to third output table output rollers pairs 78 to 80.

In the case of double-sided printing, the paper feed unit 3 sequentially feeds the unprinted paper S at a timing when the time between the paper feed timings of each paper S is doubled with respect to the paper feed timing at the time of single-sided printing. .. The paper S that has been fed is subjected to image recording while being conveyed by the belt platen 46, as in the case of single-sided printing.

The paper S after single-sided printing is guided to the circulation path RC by the switching unit 71, and is conveyed to the switchback roller pair 59 by the first and second intermediate transfer rollers pairs 56 and 57. When the switchback roller pair 59 is reached, the paper S is switched back by the switchback roller pair 59. Next, the paper S is conveyed to the vertical transfer rollers 33 by the first to third horizontal transfer rollers 61 to 63 and the ascending transfer rollers 65. Then, the paper S is re-fed to the belt platen 46 by the vertical transport roller pair 33 and the resist roller pair 35.

Here, the paper S after single-sided printing is re-fed at a timing such that it is alternately fed to the belt platen 46 with the unprinted paper S that is sequentially fed. As described above, in double-sided printing, the time between the paper feed timings of each paper S is twice as long as the paper feed timing in the case of single-sided printing. Therefore, it is possible to insert the paper S after single-sided printing between the unprinted paper S and re-feed the paper S after single-sided printing alternately with the feeding of the unprinted paper S. ..

The paper S after single-sided printing is switched back by the switchback roller pair 59 and then sent to the belt platen 46 with the unprinted side facing up. The paper S after single-sided printing is printed on the unprinted side while being conveyed by the belt platen 46. Then, the double-sided printed paper S is discharged to the post-processing device or the paper ejection table 86 by the paper ejection unit 7.

As described above, in double-sided printing, the unprinted paper S is fed and the paper S after single-sided printing is alternately fed, so that one of the unprinted paper S is fed on the belt platen 46. Printing on the front side and printing on the unprinted side of the paper S after single-sided printing are alternately performed. As a result, double-sided printing is performed with the same productivity per single side as in single-sided printing.

The occurrence of paper S jam in the transport path means that the error between the paper S detection timing and its theoretical value is equal to or greater than the threshold value in at least one of the paper sensors 37-40, 48, 67-70, 82-85. If this happens, the control unit 16 determines that a jam has occurred.

Then, when the control unit 16 determines that a jam has occurred, the control unit 16 stops the operations of the paper feeding unit 3, the belt platen transport unit 4, the circulation transport unit 6, and the paper discharge unit 7, and stops the transport of the paper S.

Further, in order for the ink pan 11 to receive the ink IK ejected by the inkjet head 53 during the purging process or the like, the control unit 16 uses the elevating drive unit 52 to move the belt platen as shown in FIG. The 46 is lowered to secure a space for the ink pan 11 to intervene between the inkjet head 53 and the belt platen 46. Then, the control unit 16 moves the ink pan 11 at the second position P1 shown in FIG. 1 to the first position P1 as shown in FIG.

When the control unit 16 returns the ink pan 11 to the second position P2, the ink IK in the ink pan 11 flows into the waste liquid pipe 13 and the waste liquid tank 12 from the discharge port 11b. When the ink IK flows into the waste liquid pipe 13 and the waste liquid tank 12, the air A in the waste liquid pipe 13 is released from the air vent path 13a as described above.

In the present embodiment described above, the image recording device 1 includes an inkjet head 53 that records an image on paper S, which is an example of a recording medium, by ejecting ink IK, and a waste liquid discharged from the inkjet head 53. An ink pan 11 that can be moved to a first position P1 that receives the ink IK, a second position P2 that is retracted from the first position P1, and a waste liquid that stores the ink IK received by the ink pan 11. A tank 12 and a waste liquid pipe 13 that sends the ink IK received by the ink pan 11 to the waste liquid tank 12 through the discharge port 11b of the ink pan 11 are provided, and the waste liquid pipe 13 is an air vent portion that allows air A in the waste liquid pipe 13 to escape. It has an air vent path 13a, which is an example.

Therefore, especially when a large amount of ink IK is accumulated in the ink pan 11, the ink IK flows into the waste liquid pipe 13, and even if the discharge port 11b of the ink pan 11 is blocked by the ink IK, the waste liquid pipe 13 is filled with the ink IK. With a simple configuration provided with the air vent path 13a, the air A in the waste liquid pipe 13 can be released from the air vent path 13a. Since the air A in the waste liquid pipe 13 can be released from the air vent path 13a in this way, the air A in the waste liquid pipe 13 advances to the discharge port 11b of the ink pan 11 in the direction opposite to the ink IK, and thus enters the atmosphere. Compared with the case where the ink is discharged, it is possible to prevent the bubbles of the discharged air A from popping and the ink IK in the ink pan 11 from scattering. Further, since the ink IK can be prevented from scattering by letting the air A in the waste liquid pipe 13 escape from the air vent path 13a, the ink IK in the ink pan 11 flows into the waste liquid pipe 13 at once and closes the discharge port 11b. In order to prevent the ink pan 11, the ink pan 11 is moved from the first position P1 to the second position P2 with a waiting time, or the ink pan 11 is slowly moved to the second position P2. It is possible to omit the operation of moving. As a result, it is possible to avoid delaying the restart of the image recording operation. Therefore, according to the present embodiment, the scattering of the ink IK in the ink pan 11 ejected from the inkjet head 53 can be suppressed without delaying the restart of the image recording operation and with a simple configuration.

Further, in the present embodiment, when the ink pan 11 is at least at the second position P2, the waste liquid pipe 13 is closed by bending downward from the ink pan 11 toward the waste liquid tank 12. A waste liquid pool (for example, below the virtual planes V1 and V2) is formed, and an air vent path 13a is provided between the discharge port 11b of the ink pan 11 and the waste liquid pool of the waste liquid pipe 13. Therefore, even if a waste liquid pool is formed in the waste liquid pipe 13, the waste liquid pool is collected even if the ink IK covers the discharge port 11b by removing the air A from between the waste liquid pool of the waste liquid pipe 13 and the discharge port 11b. Since the air A on the ink pan 11 side can be released more reliably, the scattering of ink IK can be reliably suppressed.

The present invention is not limited to the above-described embodiment as it is, and the components can be modified and embodied within a range that does not deviate from the gist at the implementation stage. In addition, various inventions can be formed by an appropriate combination of the plurality of components disclosed in the above-described embodiment. For example, all the components shown in the embodiments may be combined as appropriate. It goes without saying that various modifications and applications are possible within the range that does not deviate from the gist of the invention. Hereinafter, the inventions described in the claims at the time of filing the application of the present application will be added.

[Appendix 1]
An inkjet head that records images on a recording medium by ejecting ink,
An ink pan that can be moved to a first position that receives the waste ink discharged from the inkjet head and a second position that is retracted from the first position.
A waste liquid tank that stores the ink received by the ink pan, and
A waste liquid pipe for sending the ink received by the ink pan to the waste liquid tank through the discharge port of the ink pan is provided.
The waste liquid pipe is an image recording apparatus characterized by having an air vent portion for letting air in the waste liquid pipe escape.
[Appendix 2]
When the ink pan is at least in the second position, the waste liquid pipe is curved downward from the ink pan toward the waste liquid tank to form a waste liquid pool that closes the waste liquid pipe.
The image recording device according to Appendix 1, wherein the air vent portion is provided between the discharge port and the waste liquid pool.

1 Image recording device 10 Waste liquid recovery device 11 Ink pan 11a Ink pan body 11b Outlet 11c Partition wall 12 Waste liquid tank 12a Inlet 13 Waste liquid pipe 13a Air vent path 13b Bending apex 46 Belt platen 53 Inkjet head A Air IK ink S V2 virtual plane

Claims (2)

An inkjet head that records images on a recording medium by ejecting ink,
An ink pan that can be moved to a first position that receives the waste ink discharged from the inkjet head and a second position that is retracted from the first position.
A waste liquid tank that stores the ink received by the ink pan, and
A waste liquid pipe for sending the ink received by the ink pan to the waste liquid tank through the discharge port of the ink pan is provided.
The waste liquid pipe is provided inside the waste liquid pipe and has an air vent portion for allowing air in the waste liquid pipe to escape.
The outlet of the ink pan is provided with an air vent path communicating with the air vent portion.
An image recording device characterized by the fact that. When the ink pan is at least in the second position, the waste liquid pipe is curved downward from the ink pan toward the waste liquid tank to form a waste liquid pool that closes the waste liquid pipe.
The image recording apparatus according to claim 1, wherein the air vent portion is provided between the discharge port and the waste liquid pool.

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