JP2013180565A - Inkjet recorder - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an inkjet recorder of which the throughput related to printing can be improved, the inkjet recorder having a constitution in which a recording head is moved to a retreat position after finishing recording on one surface of recording paper.SOLUTION: In a case where it is determined that a recording medium is held between a first conveying part and a second conveying part when finishing recording on the recording medium, a retreat controller moves a recording part to the predetermined retreat position, while the first conveying part and the second conveying part are allowed to convey the recording medium to a downstream side in a conveying direction. In a case where the recording medium is held between the first conveying part and the second conveying part, there are few possibilities that the recording medium rises between the first conveying part and the second conveying part. As a result, even if the recording part is moved to the predetermined retreat position while conveying the recording medium to the downstream side in the conveying direction, the recording medium does not come into contact with a nozzle, and the throughput related to printing can be improved.

Description

  The present invention relates to an ink jet recording apparatus.

  2. Description of the Related Art An ink jet recording apparatus is known that records an image or the like by ejecting ink from nozzles while reciprocally scanning a recording head having a plurality of nozzles in a main scanning direction orthogonal to the conveyance direction of recording paper (recording medium). . In the ink jet recording apparatus, a pair of transport rollers and a pair of paper discharge rollers that are transported while sandwiching a recording sheet are provided on the upstream side and the downstream side in the transport direction via the recording head, respectively. Since the recording head is interposed between the conveying roller pair and the paper discharge roller pair, the distance between these roller pairs is relatively long. For this reason, in a state where the recording sheet is sandwiched between one of the conveying roller pair and the discharging roller pair, the end of the recording sheet may float between the conveying roller pair and the discharging roller pair. When the end of the recording paper floats between the pair of conveyance rollers and the discharge roller pair, depending on the position of the recording head at that time, the floating end and the recording head (for example, a nozzle) come into contact with each other. The recording paper may become dirty or the nozzles may be damaged.

  In order to prevent such contact, in the conventional inkjet recording apparatus, for example, as described in Patent Document 1, after recording on the recording paper is finished, the transport of the recorded recording paper is temporarily stopped and the recording head is recorded. The paper was moved to a standby position (retracted position) provided outside the paper passage range, and transporting was resumed on the condition that the recording head reached the standby position to discharge the recording paper.

JP-A-8-169125

  However, since the above-described conventional inkjet recording apparatus stops the conveyance of the recording paper while moving the recording head to the standby position, the processing time required for recording on one page of recording paper becomes longer, and printing is performed accordingly. As a result, the throughput is reduced.

  The present invention has been made in view of the above-described circumstances, and an inkjet recording apparatus capable of improving the throughput of printing in a configuration in which a recording head is moved to a retracted position after recording on one surface of a recording sheet is completed. The purpose is to provide.

  In order to achieve this object, the inkjet recording apparatus of the present invention is provided on the downstream side of the first transport unit in the transport direction, the first transport unit transporting in the transport direction while sandwiching the recording medium, A recording unit having a plurality of nozzles for discharging ink while moving in a main scanning direction orthogonal to the conveyance direction on the recording medium conveyed to the first conveyance unit, and downstream from the recording unit in the conveyance direction And a second transport unit that transports the recording medium in the transport direction while sandwiching the recording medium, and when the recording by the recording unit with respect to the recording medium is completed, the recording medium is the first transport unit A determination unit that determines whether the recording medium is sandwiched between the first transport unit and the second transport unit, and a determination unit that determines whether the recording medium is sandwiched between the first transport unit and the second transport unit. First transfer And a retraction control unit that moves the recording unit to a predetermined retraction position in the main scanning direction while conveying the recording medium downstream in the conveyance direction to the second conveyance unit, and the predetermined retraction The position is a position where the nozzle is arranged in an area outside the area where the recording medium is conveyed by the first conveyance unit and the second conveyance unit in the main scanning direction.

  The present invention can be realized in various modes such as a control device that controls an ink jet recording apparatus, an ink jet recording system, a recording method, and a recording medium that records a control program.

  According to the ink jet recording apparatus of claim 1, when recording by the recording unit is completed on the recording medium, the determination unit determines that the recording medium is sandwiched between the first transport unit and the second transport unit. In this case, there is almost no possibility that the recording medium is lifted between the first conveyance section and the second conveyance section, so that the recording section is evacuated to a predetermined extent while conveying the recording medium downstream in the conveyance direction. Even if moved to the position, contact between the recording medium and the nozzle can be prevented. Since the recording unit is moved to the retracted position while transporting the recording medium, it is possible to improve the printing throughput as compared with the case where the recording medium is stopped while the recording unit is moved to the retracting position.

  According to the ink jet recording apparatus of the second aspect, the following effect is obtained in addition to the effect of the first aspect. The determination as to whether the recording medium is sandwiched between the first conveyance unit and the second conveyance unit is performed by the detection unit provided on the upstream side of the first conveyance unit in the conveyance direction at the downstream end in the conveyance direction of the recording medium. This is performed based on the transport amount of the recording medium after the signal is output based on the transport. Therefore, the determination can be realized.

  According to the ink jet recording apparatus of the third aspect, in addition to the effect produced by the first or second aspect, the following effect is produced. The determination as to whether the recording medium is sandwiched between the first conveyance unit and the second conveyance unit is performed by the detection unit provided on the upstream side of the first conveyance unit in the conveyance direction at the upstream end in the conveyance direction of the recording medium. This is performed based on the transport amount of the recording medium after the signal is output based on the transport. Therefore, the determination can be realized. In addition, since the position of the upstream end in the transport direction of the recording medium can be obtained without using the set value of the size of the recording medium, even if the actual size of the recording medium is different from the set value, It is possible to appropriately determine whether the recording medium is pinched by the first transport unit or not by the first transport unit.

  According to the ink jet recording apparatus of claim 4, in addition to the effect of claim 2 or 3, the following effect is obtained. The first time (the time until the upstream end in the conveyance direction of the recording medium is not clamped by the first conveyance unit) is the second time (the recording unit is determined from the position of the recording unit when the recording is completed). If the recording time is equal to or longer than the retreat position, the upstream end in the transport direction of the recording medium does not leave the first transport section before the recording section reaches the predetermined retract position. Therefore, even if the recording unit is moved to a predetermined retracted position while conveying the recording medium downstream in the conveying direction, contact between the recording medium and the nozzle can be reliably prevented.

  According to the ink jet recording apparatus of the fifth aspect, in addition to the effect exhibited by any one of the second to fourth aspects, the following effect is exhibited. Even when the first time is not equal to or longer than the second time (when the first time is less than the second time), recording is started after the movement of the recording unit is started (second time-first time). Since the conveyance of the medium is started, the upstream end in the conveyance direction of the recording medium does not come out of the first conveyance unit before the recording unit reaches the predetermined retraction position, and contact between the recording medium and the nozzle is prevented. It can be surely prevented.

  According to the ink jet recording apparatus of the sixth aspect, in addition to the effect produced by any one of the first to fifth aspects, the following effect is obtained. When the recording is completed, the recording unit is moved to the retracted position closest to the position of the recording unit. Therefore, the time for the recording unit to move to the retracted position can be minimized, and the printing throughput can be improved.

  According to the ink jet recording apparatus of the seventh aspect, in addition to the effect exhibited by any one of the first to fifth aspects, the following effect is exhibited. When recording on the next recording medium after recording on the recording medium is completed, the recording unit is moved to the retreat position provided on the side where recording on the next recording medium is started. Recording on the next recording medium can be started without moving the recording unit wastefully. Therefore, the throughput related to printing can be improved.

  According to the ink jet recording apparatus of the eighth aspect, in addition to the effect produced by any one of the first to fifth aspects, the following effect is obtained. When recording on the first surface of the recording medium is completed in double-sided printing, the recording unit is moved to the retracted position on the side where the first position is to switch the passage path of the recording medium for which recording has been completed to the reverse path. Since it is moved, it is possible to improve the throughput related to printing without moving the recording unit unnecessarily to reverse the recording surface.

  According to the ink jet recording apparatus of the ninth aspect, in addition to the effect of the eighth aspect, the retracted position is a position when the recording unit is at the first position, and thus serves as both the retracted position and the first position. Therefore, the throughput related to printing can be improved more suitably.

  According to the ink jet recording apparatus of the tenth aspect, in addition to the effect exhibited by any one of the first to seventh aspects, the following effect is exhibited. When the type of the recording medium is a type other than the type designated in advance as being easy to float during conveyance (that is, the type that is difficult to float during conveyance), the recording unit does not have to be moved to the retracted position. There is almost no possibility of contact between the recording medium and the nozzle. Therefore, in such a case, when recording on the recording medium is completed, the printing-related throughput can be improved by discharging the recording unit without moving the recording unit to the retracted position.

  According to the ink jet recording apparatus of the eleventh aspect, in addition to the effect exhibited by any one of the first to tenth aspects, the following effect is exhibited. Since the retraction position candidates are determined according to the positions of both ends of the recording medium in the main scanning direction, the retraction positions can be variably set according to the positions of both ends. Therefore, the retracted position can be prevented from being unnecessarily separated from the end of the recording medium in the main scanning direction, and the printing throughput can be improved. In addition, each time the storage unit for storing the recording medium is opened, the candidate for the retreat position is determined. Therefore, even if the size of the recording medium stored in the storage unit changes, it is suitable for the changed size. Retreat position candidates can be determined.

  According to the ink jet recording apparatus of the twelfth aspect, the same effect as that of the ink jet recording apparatus of the first aspect is obtained.

1 is a block diagram illustrating an electrical configuration of an MFP that is an embodiment of inkjet recording of the present invention. FIG. FIG. 2 is a diagram illustrating an ink jet printer installed in an MFP. FIG. 2 is a diagram illustrating an ink jet printer installed in an MFP. 6 is a flowchart illustrating print control processing. (A) And (b) is a flowchart which respectively shows a evacuation position candidate acquisition process and a paper center position acquisition process. It is a flowchart which shows the save process at the time of the next page printing. It is a flowchart which shows the save process at the time of the last page printing. It is a flowchart which shows the evacuation process at the time of duplex printing.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings. FIG. 1 is a block diagram showing an electrical configuration of a multifunction peripheral device (hereinafter referred to as “MFP”) 1 which is an embodiment of the ink jet recording apparatus of the present invention. The MFP 1 is a multifunction device having a plurality of functions such as a print function, a scan function, and a copy function. When printing on one side of the recording paper is completed, the MFP 1 of the present embodiment moves the recording head 21c to a predetermined retreat position while conveying the recording paper under a predetermined condition, thereby printing. To improve the throughput.

  The MFP 1 is provided with a CPU 10, a flash memory 11, a RAM 12, an operation key 15, an LCD 16, a touch panel 17, a scanner 20, a printer 21, and a USB_I / F (USB interface) 22. The CPU 10, flash memory 11, and RAM 12 are connected to each other via a bus line 23. The operation key 15, LCD 16, touch panel 17, scanner 20, printer 21, USB_I / F 22, and bus line 23 are connected to each other via an ASIC (Application Specific Integrated Circuit) 24.

  The CPU 10 controls each function of the MFP 1 and each unit connected to the ASIC 24 according to fixed values and programs stored in the flash memory 11 and data stored in the RAM 12. The flash memory 11 is a non-volatile memory, and stores a control program 11a for controlling the operation of the MFP 1. Each process shown in the flowcharts of FIGS. 4 to 8 described later is executed by the CPU 10 in accordance with the control program 11a.

  The RAM 12 is a rewritable volatile memory that temporarily stores information necessary for the processing of the CPU 10. The RAM 12 is provided with a retreat position memory 12a and a sheet center position memory 12b. The retreat position memory 12a is an area for storing a retreat position candidate for retreating the recording head 21c after printing on one surface of the recording paper is completed. The “retreat position” is a position at which the recording head 21c is retracted so that the recorded recording sheet and the nozzles of the recording head 21c do not come into contact after printing on one surface of the recording sheet. The sheet center position memory 12c is an area for storing the center position of the recording sheet.

  The operation key 15 is a mechanical key and accepts input of various setting values and instructions from the user. The LCD 16 is a liquid crystal display device. The touch panel 17 is provided so as to overlap the LCD 16 and accepts input of various setting values and instructions from the user. The USB_I / F 24 is a device for connecting other devices (for example, a personal computer) via a USB cable so as to communicate with each other, and is configured by a known device. In this embodiment, a personal computer (PC) 500 is connected via the USB_I / F 24. The scanner 20 is a device that reads an original and outputs image data of the read original to the CPU 10.

  The printer 21 is an ink jet printer that prints (records) an image on a recording sheet by ejecting ink. The printer 21 includes a first drive motor 21a, a second drive motor 21b, a recording head 21c, a media sensor 21d, a registration sensor 21e, and an encoder 21f. Each part 21a-21f is connected to ASIC24. The first drive motor 21a applies driving force to the transport roller 41, the paper discharge roller 43, and the SB roller 45 (see FIG. 2 above). The second drive motor 21b applies a driving force to the paper feed roller 34, the reverse feed roller 47 (see FIG. 2 above), and the cap 213 (see FIG. 3A). The transmission destination of the driving force of the second drive motor 21b is switched by the drive transmission switching mechanism 214 (see FIG. 3A). Further, the printer 21 is provided with a carriage motor that provides a driving force for moving the carriage 211 (see FIGS. 2 and 3) in the main scanning direction. A drive circuit for controlling each drive motor 21a, 21b and carriage motor (not shown) is incorporated in the ASIC 24 for each motor, and the motor corresponding to the drive signal is based on the drive signal from the CPU 10. Forward rotation or reverse rotation at a rotation speed according to the drive signal. Hereinafter, when the CPU 10 sends the drive signal and controls the rotation of the motor to convey the recording paper, the CPU 10 simply describes that the CPU 10 conveys the recording paper. The recording head 21c is mounted on the carriage 211 and has a large number of nozzles formed on the surface facing the platen 212 (see FIGS. 2 and 3), and discharges ink as fine ink droplets from these nozzles. .

  The media sensor 21d is a well-known sensor that detects the positions of both ends of the recording paper in the main scanning direction, and includes a light emitter (not shown) made up of an LED and the like, and an optical sensor (not shown). . The media sensor 21d is provided on the lower surface of the carriage 211 (the surface on the side facing the platen 212).

  The registration sensor 21e is a known sensor that detects the leading edge and the trailing edge of a recording sheet to be printed. Note that the “tip” of the recording paper is an end of the recording paper on the printing start side, and is an end of the recording paper on the downstream side in the transport direction. On the other hand, the “rear end” of the recording paper is an end on the recording paper where printing is finished, and is an upstream end of the recording paper in the transport direction. The registration sensor 21e includes a light emitter (not shown) such as an LED and an optical sensor (not shown). The registration sensor 21e is installed at a predetermined position on the upstream side in the transport direction from the recording head 21c in the main transport path 35 (see FIG. 2). The registration sensor 21e detects the leading edge and the trailing edge of the recording paper passing through the predetermined position, and outputs the detection result to the CPU 10.

  The rotary encoder 21f detects the rotation amount of the transport roller 41 driven by the LF motor 21b, and outputs an encoder signal corresponding to the detected rotation amount to the CPU 10. The CPU 10 calculates the transport amount of the recording paper based on the encoder signal output from the rotary encoder 21f.

  Here, the printer 21 will be described in more detail with reference to FIGS. 2 and 3. FIG. 2 is a schematic side sectional view schematically showing the internal structure of the printer 21. An arrow U direction and a Bo direction in FIG. 2 indicate the upper side and the lower side of the printer 21 (MFP 1), respectively.

  A paper feed tray 31 is detachably mounted below the printer 21. The paper feed tray 31 has a container shape with an opening formed on the upper surface, and the recording paper S is stored in a stacked state in the internal space. For example, various recording papers such as plain paper, glossy paper, and envelopes of various sizes can be stored in the paper feed tray 20 as the recording paper S. In the present embodiment, a sensor (not shown) for detecting attachment / detachment of the paper feed tray 31 is provided in the printer 21, and the CPU 10 detects attachment / detachment of the paper feed tray 31 according to the output of the sensor. it can.

  A base end side of the support arm 33 is rotatably supported on a shaft 32 installed above the paper feed tray 31. A paper feed roller 34 is rotatably supported at the tip of the support arm 33. The support arm 33 is biased by the weight of the paper feed roller 34, a spring, and the like, and is rotated downward, whereby the paper feed roller 34 contacts the upper surface of the recording paper S accommodated in the paper feed tray 31. . The paper feed roller 34 rotates when the driving force (rotational force) of the second drive motor 21b is transmitted through a known drive transmission mechanism (not shown). When the second drive motor 21b rotates forward and the paper feed roller 34 rotates forward, the recording paper S in the paper feed tray 31 is mainly conveyed by the frictional force between the roller surface of the paper feed roller 34 and the recording paper S. Guided to road 35. The main transport path 35 passes between the carriage 211 and the platen 212 and leads to the paper discharge tray 36.

  A transport roller 41 is rotatably provided upstream of the carriage 211 in the transport direction. The conveyance roller 41 and the pinch roller 42 arranged in pressure contact with the conveyance roller 41 constitute a conveyance roller pair. When the recording sheet S enters between the conveying roller 41 and the pinch roller 42, the recording sheet S is conveyed in a direction corresponding to the rotation direction of the conveying roller 41 while being sandwiched between these rollers 41 and 42. On the other hand, a discharge roller 43 is rotatably provided downstream of the carriage 211 in the transport direction. The paper discharge roller 43 and the spur roller 44 arranged in pressure contact with the paper discharge roller 43 constitute a paper discharge roller pair. When the recording paper S enters between the paper discharge roller 43 and the spur roller 44, the recording paper S is conveyed in a direction corresponding to the rotation direction of the paper discharge roller 43 while being sandwiched between these rollers 43 and 44. .

  The transport roller 41 and the paper discharge roller 43 rotate continuously or intermittently in synchronization with a driving force (rotational force) transmitted from the first drive motor 21a via a drive transmission mechanism (not shown). More specifically, when the first drive motor 21a rotates forward, the transport roller 41 and the paper discharge roller 43 rotate forward to transport the recording paper S from the upstream side to the downstream side in the transport direction. When the first drive motor 21a rotates in the reverse direction, the transport roller 41 and the paper discharge roller 43 rotate in reverse to transport the recording paper S from the downstream side to the upstream side in the transport direction (reverse transport).

  A switchback roller (hereinafter referred to as “SB roller”) 45 is provided downstream of the paper discharge roller 43 in the transport direction. The SB roller 45 and the spur roller 46 disposed in pressure contact with the SB roller 45 constitute a SB roller pair. The SB roller 45 is also rotated by the driving force of the first drive motor 21a, like the transport roller 41 and the paper discharge roller 43. Therefore, when the first drive motor 21a rotates in the forward direction, the SB roller 45 rotates in the forward direction and transports the recording paper S from the upstream side to the downstream side in the transport direction. On the other hand, when the first drive motor 21a rotates in the reverse direction, the SB roller 43 rotates in the reverse direction and transports the recording paper S from the downstream side to the upstream side in the transport direction.

  A paper discharge tray 36 is provided downstream of the SB roller 45 in the transport direction. Therefore, when the SB roller 45 is rotated forward, the recording paper S is conveyed toward the paper discharge tray 36. On the other hand, a branch port 37 is provided between the SB roller 45 and the paper discharge roller 43 to guide the recording paper S to the reverse conveyance path 38 that reverses the printing surface (recording surface). Therefore, when the rotation of the SB roller 45 is switched from the normal rotation to the reverse rotation in a state where the SB roller 45 and the spur roller 45 sandwich the rear end of the recorded recording paper S, the recording paper S is brought into the branch port 37. Then, it is guided to the reverse conveyance path 38. The reverse conveyance path 38 is a conveyance path that passes between the platen 212 and the paper feed tray 31 and is connected to the upstream side of the conveyance roller 41 in the main conveyance path 35. When performing double-sided printing, after printing on the first surface (for example, the front surface) of the recording paper S, the SB roller 45 holds the rear end of the first surface of the recording paper S. The printing surface can be changed to the second surface, which is the back surface of the first surface, by rotating 24 in the reverse direction and guiding the rear end from the branch port 37 to the reversing path 38.

  A reverse feed roller 47 is provided in the reverse conveyance path 38. The counter feed roller 47 and the pinch roller 48 arranged in pressure contact with the counter feed roller 47 constitute a counter feed roller pair. The counter-feed roller 47 is rotated by a driving force (rotational force) transmitted from the second drive motor 21b via a drive transmission mechanism (not shown). When the second drive motor 21b rotates forward and the reverse feed roller 47 rotates forward, the recording paper S is transported toward the main transport path 35.

  3A is a schematic plan view of the vicinity of the carriage 211 in the printer 21, and FIG. 3B is a schematic side sectional view taken along line IIIb-IIIb in FIG. 3A. The carriage 211 is reciprocated in the main scanning direction by forward or reverse rotation of a carriage motor (not shown). Specifically, the carriage 211 is alternately moved in a forward direction that is a direction away from the home position in the main scanning direction and a reverse direction that is the opposite direction. Hereinafter, the forward direction and the reverse direction may be simply referred to as “left side” and “right side”, respectively. On the upstream side of the carriage 211 in the transport direction, a protrusion 211a is provided continuously. The protrusion 211a is reciprocated in the main scanning direction together with the carriage 211.

  The recording head 21c is scanned in the main scanning direction (forward direction or reverse direction) by the movement of the carriage 211, and ejects ink onto the recording sheet S conveyed on the platen 212 to print images, characters, and the like ( Record. The printer 21 of this embodiment has nozzles C, M, Y, and K that can eject a plurality of colors (cyan, magenta, yellow, and black), respectively, so that the recording head 21d can form an image with a plurality of colors. The The nozzles C, M, Y, and K of each color constitute a nozzle group that includes one or a plurality of nozzle rows arranged in the transport direction. In FIG. 3A, the nozzles C, M, Y, and K of the respective colors are shown as large circles in an easy-to-understand manner, but actually, a large number of nozzles with small openings are formed for any color.

  The cap 213 is provided on the home position side of the carriage 211 in the platen 212. The cap 213 is moved between a contact position that covers the discharge port of the nozzle of the recording head 21c and a position that is separated from the discharge port by a moving mechanism (not shown). A moving mechanism (not shown) is operated by the driving force transmitted from the second drive motor 21b. If necessary, the MFP 1 moves the recording head 21c to a position facing the cap 213, and then moves the cap 213 upward to the contact position, thereby bringing the cap 213 into close contact with the nozzle formation surface of the recording head 21c. When the inside of the cap 213 is depressurized by a suction pump (not shown) in this tight contact state, dust, bubbles, thickened ink, etc. present in each ink flow path are ejected from the discharge ports of the nozzles C, M, Y, and K. Are sucked and discharged together with ink (suction purge).

  A drive transmission switching mechanism 214 is provided on the right side (reverse direction side) of the platen 212 on the upstream side in the transport direction. The drive transmission switching mechanism 214 includes a drive gear (not shown) that is rotationally driven by the second drive motor 21b, a receiving gear (not shown) corresponding to the transmission destination of the driving force, and a driving gear and a receiving gear. And a switching gear (not shown) interposed therebetween. The drive transmission switching mechanism 214 switches the transmission destination of the rotational driving force of the second drive motor 21b by switching the receiving gear connected to the switching gear. As the drive transmission switching mechanism 214, for example, a power transmission switching unit or a drive transmission switching mechanism described in Japanese Patent Application Laid-Open No. 2007-90761, Japanese Patent Application Laid-Open No. 2012-878, or the like can be employed.

  The switching gear of the drive transmission switching mechanism 214 is connected to a receiving gear corresponding to the position of a lever 214a that protrudes on the upper side (front side of the sheet) of the printer 21. In the present embodiment, since the paper feed roller 34, the reverse feed roller 47, and the cap 213 are the transmission destinations of the rotational driving force of the second drive motor 21b, three receiving gears are provided. The lever 214a is provided at a position where the protrusion 211a of the carriage 211 can contact. Therefore, as the carriage 211 moves, the protrusion 211a abuts on the lever 214a, and the position of the lever 214a can be changed. Therefore, by controlling the position of the protrusion 211a, the position of the lever 214a can be changed, and the transmission destination of the driving force for rotation of the second drive motor 21b can be switched.

  When the lever 214a is disposed at the first position P1 on the leftmost side (forward direction side), the switching gear is connected to a receiving gear whose driving force is transmitted to the paper feed roller 34. Therefore, when the recording paper S is fed from the paper feed tray 31, the lever 214a is disposed at the first position P1, and the paper feed roller 34 is driven by the second drive motor 21b. FIG. 3A shows a state where the lever 214a is at the first position P1. When the lever 214a is disposed at the second position P2 on the right side of the first position P1, the switching gear is connected to a receiving gear whose driving force is transmitted to the counter-feed roller 47. Therefore, when performing double-sided printing, the lever 214a is positioned at the second position, the reverse feed roller 47 is driven by the second drive motor 21b, and the recorded data is recorded on the first surface guided by the reverse conveyance path 38. The sheet S is conveyed and the recording surface of the recording sheet S is reversed.

  When the lever 214a is disposed at the third position P3 on the right side of the second position P2, the switching gear is connected to a receiving gear whose driving force is transmitted to the cap 213. At this time, the recording head 21 c is located at a position where the nozzle can be capped by the cap 213. Therefore, when performing the suction purge of the nozzle, the lever 214a is positioned at the third position, and the cap 213 is driven by the second drive motor 21b. The position of the lever 214a is configured to be positionable at each of the positions P1 to P3. When the lever 214a is positioned, the lever 214a stays at that position unless the lever 214a is further moved to the right side by the protrusion 211a. The switching gear is urged to the left side by a spring or the like. When the lever 211a is moved to the right side from the third position P3 and then the carriage 211 is moved to the left side, the switching gear is moved to the first position P1. Configured to go back.

  As shown in FIG. 3B, the media sensor 21d is provided upstream of the recording head 21c on the lower surface of the carriage 211 (the surface facing the platen 212). The media sensor 21d emits light from the light emitting unit (not shown) toward the platen 212, and the reflected light reflected by the platen 212 or the recording paper S thereon is received by the light receiving unit (not shown). The amount of light (the amount of reflected light) is detected by the light receiving unit. The media sensor 21e outputs a detection value (AD value) of the amount of reflected light detected by the light receiving unit to the CPU 10. These operations by the media sensor 21d are executed based on control from the CPU 10. When the surface of the platen 212 is a color having a low reflectance such as black, the detected value by the reflected light of the recording sheet S and the detected value by the reflected light from the platen 212 are different from each other. The edge of the recording paper S can be detected based on the detection value supplied from 21d.

  FIG. 4 is a flowchart showing print control processing executed by the CPU 10 of the MFP 1. In the print control process of the present embodiment, when printing on one surface of a recording sheet is completed, the carriage 211 (recording head 21c) is moved to a predetermined retreat position while conveying the recording sheet under a predetermined condition. Let This process is started when the MFP 1 receives pass data from the PC 500 when a predetermined print instruction is input to the PC 500. Note that “pass” means main scanning of the recording head 21c, and “1 pass” means one pass (that is, one main scanning). “Pass data” means print data in pass units. Note that the MFP 1 receives from the PC 500, along with the pass data, information on single-sided printing or double-sided printing, and information on the type and size of the recording paper to be printed. In the present embodiment, the types of recording paper that can be printed are three types: plain paper, envelope, and glossy paper. Of these types, plain paper and envelopes are classified as recording papers that tend to float, and glossy papers are classified as recording papers that tend to float.

  First, in step S401 (hereinafter, step is omitted), the CPU 10 rotates the paper feed roller 34 to feed one recording sheet from the paper feed tray 31 (S401). Next, when the CPU 10 determines that the type of recording paper to be printed is a recording paper that tends to be lifted (in this embodiment, plain paper or envelope) (S402: Yes), the MFP 1 is turned on. If it is the subsequent first page (S403: Yes), the CPU 10 executes a save position candidate acquisition process for acquiring a save position candidate and storing it in the save position memory 12a (S405). Details of the evacuation position candidate acquisition process (S405) will be described later with reference to FIG.

  In the case where it is not the first page after the MFP 1 is turned on but the first page after the paper feed tray 31 is detached (S403: No, S404: Yes), the CPU 10 performs the evacuation position candidate acquisition process. Execute (S405). That is, the retreat position candidate acquisition process (S405) is executed every time the paper feed tray 31 is detached. After executing the evacuation position candidate acquisition process (S405), the CPU 10 executes the paper center position acquisition process of acquiring the central position of the recording paper and storing it in the paper center position memory 12b (S406), and the process proceeds to S407. . Details of the sheet center position acquisition process (S406) will be described later with reference to FIG.

  On the other hand, if it is not the first page after the MFP 1 is turned on and the first page after the paper feed tray 31 is detached (S403: No, S404: No), the retraction position memory 12a and the paper center position Since the evacuation position candidates and the sheet center position respectively stored in the memory 12b are used, the CPU 10 shifts the processing to S407. In S402, when the CPU 10 determines that the type of recording paper to be printed is a recording paper that tends to be difficult to lift (in this embodiment, glossy paper) (S402: No), the recording head 21c Since there is no need to perform saving, the CPU 10 shifts the processing to S407.

  In S407, the CPU 10 rotates the transport roller 41 and the paper discharge roller 43 to transport the recording paper to the printing position (S407). Next, the CPU 10 causes the printer 21 to execute printing for one pass based on the pass data (S408). If the pass printed in S408 is not the final pass (S409: No), the CPU 10 shifts the process to S407.

  If the pass printed in S408 is the final pass (S409: Yes), the CPU 10 shifts the process to S410. When the CPU 10 determines that the type of recording paper to be printed is plain paper or an envelope (S410: Yes), the CPU 10 executes the processes of S411 to S415 in order to retract the recording head 21c to the retracted position. . Specifically, in the case of duplex printing and printing of the back side (S411: Yes), the CPU 10 executes a saving process at the time of printing on the back side (S415), shifts the process to S402, and prints on the back side. I do.

  On the other hand, when there is a next page after executing single-sided printing or after printing the back side in double-sided printing (S411: No, S412: Yes), the CPU 10 executes a saving process at the time of printing the next page (S413). In step S401, the next page is printed on the recording sheet. If there is no next page (S411: No, S412: No), the CPU 10 executes a saving process at the time of printing the last page (S414), and ends this process. Details of the saving process at the time of printing the next page (S413), the saving process at the time of printing the last page (S414), and the saving process at the time of printing the back side (S415) will be described later with reference to FIGS. To do.

  In S410, when the CPU 10 determines that the type of the recording paper to be printed is glossy paper (S410: No), the CPU 10 does not need to retract the recording head 21c, so the CPU 10 uses the recorded recording paper. The paper is discharged onto the paper discharge tray 36 (S416), and this process is terminated. If the back side is to be printed next by double-sided printing after the execution of step S416, the CPU 10 reverses and feeds the recording paper, and then the process proceeds to S402, where the recording paper is printed on the next page. In the case of performing printing, the CPU 10 may shift the process to S401.

  FIG. 5A is a flowchart showing the above-described retreat position candidate acquisition process (S405). First, the CPU 10 conveys the recording paper to the detection position by the media sensor 21d (S501). Specifically, in S501, after the leading edge of the recording sheet is detected by the registration sensor 21e, the CPU 10 moves the recording sheet by “(distance from the detection position by the registration sensor 21e to the detection position by the media sensor 21d) + α”. Transport. Note that α is the distance from the leading edge of the recording paper to the position where the media sensor 21d is scanned. Therefore, when the position where the media sensor 21d is scanned is, for example, the leading edge of the recording paper, the value of α is zero. The position where the media sensor 21d is scanned can be set as appropriate. Next, the CPU 10 scans the media sensor 21d while moving the carriage 211, and detects the positions of the left and right edges of the recording sheet in the main scanning direction (specifically, the coordinates of the left and right edges of the sheet in the main scanning direction). (S502).

  Next, the CPU 10 obtains the retracted position on the left side (forward direction side) in the main scanning direction (S503). In the present embodiment, the CPU 10 moves the reference position (for example, the center) in the main scanning direction of the carriage 211 to the left side in the main scanning direction by a predetermined required retraction distance from the position of the left edge of the sheet acquired in S502. Is obtained as the left retracted position. Next, the CPU 10 acquires a retreat position on the right side (reverse direction) in the main scanning direction (S504). In the present embodiment, the CPU 10 moves the reference position (for example, the center) in the main scanning direction of the carriage 211 to the right side in the main scanning direction by a predetermined required retraction distance from the right edge position of the sheet acquired in S502. Is acquired as the right-side retraction position.

  As for the “required distance”, at least the nozzles of the recording head 21c are arranged in an area that is out of the conveyance area of the recording paper in the main scanning direction (that is, an area having the paper left end and the paper right end as both ends in the main scanning direction). It is the distance necessary for this. In the present embodiment, it is assumed that the CPU 10 acquires one retreat position each in S503 and S504. That is, in this embodiment, one retreat position is provided on each of the left and right sides. Next, the CPU 10 stores the left and right retreat positions acquired in S503 and S504 as retreat position candidates in the retreat position memory 12a (S505), and ends this process.

  FIG. 5B is a flowchart showing the above-described sheet center position acquisition process (S406). First, the CPU 10 calculates the sheet center position based on the positions of the left and right edges of the sheet acquired in S502 (S521). Specifically, the CPU 10 calculates the paper center position as (paper left edge position + paper right edge position) / 2. Next, the CPU 10 stores the calculated sheet center position in the sheet center position memory 12b (S522), and ends this process.

  FIG. 6 is a flowchart showing the save process (S413) when printing the next page described above. In this process, the CPU 10 first determines whether the print start position of the next page is closer to the left or right retreat position (S601). Specifically, when the print start position of the next page is on the right side, the CPU 10 determines in S601 that the print start position is close to the right side retraction position. On the other hand, if the print start position of the next page is on the left side, the CPU 10 determines in S601 that the print start position is close to the left retraction position.

  When the CPU 10 determines that the printing start position of the next page is close to the right side (S601: right side), the CPU 10 selects the right side saving position stored in the saving position memory 12a as the saving position (S602), and performs the processing. The process proceeds to S603. On the other hand, when the CPU 10 determines that the printing start position of the next page is close to the left side (S601: left side), the CPU 10 selects the left side saving position stored in the saving position memory 12a as the saving position (S617). The process proceeds to S603. Therefore, when there is a next page after executing single-sided printing or after printing the back side in double-sided printing, the retreat position closest to the print start position of the next page is selected as the retreat position by the processing of S601, S602, and S617. .

  In S603, the CPU 10 acquires the position of the recording paper (S603). In the present embodiment, the CPU 10 acquires the conveyance amount after the leading edge of the recording paper is detected by the registration sensor 21e as the position of the recording paper. Next, the CPU 10 determines whether both the transport roller 41 and the paper discharge roller 43 are holding the recording sheet based on the position of the recording sheet acquired in S603 (S604). Whether or not the conveyance roller 41 holds the recording sheet is detected by, for example, the distance obtained by subtracting the length in the conveyance direction of the recording sheet from the conveyance amount after the leading edge of the recording sheet is detected by the registration sensor 21e and the registration sensor 21e. This can be determined by comparison with the distance from the position to the nip position of the conveying roller 41. Note that “the length in the conveyance direction of the recording paper” is based on the size of the recording paper received from the PC 500. In the case of the above example, if the former distance is less than or equal to the latter distance, the trailing edge of the recording paper has not come off from the conveyance roller 41, so the CPU 10 determines that the conveyance roller 41 is pinching the recording paper. On the other hand, if the former distance is longer than the latter distance, the trailing edge of the recording sheet is removed from the conveyance roller 41, so the CPU 10 determines that the conveyance roller 41 does not pinch the recording sheet. Whether or not the paper discharge roller 43 holds the recording paper is determined, for example, by the conveyance amount after the leading edge of the recording paper is detected by the registration sensor 21e and the detection position by the registration sensor 21e and the nip position of the paper discharge roller 43. It can be judged by comparison with the distance. In this example, if the former distance is greater than or equal to the latter distance, the leading edge of the recording paper has not come off from the paper discharge roller 43, so the CPU 10 determines that the paper discharge roller 43 holds the recording paper. . On the other hand, if the former distance is shorter than the latter distance, the leading edge of the recording paper has come off from the paper discharge roller 43, so the CPU 10 determines that the paper discharge roller 43 does not pinch the recording paper.

  In S604, when the CPU 10 determines that both the conveyance roller 41 and the paper discharge roller 43 do not hold the recording paper (S604: No), the end of the recording paper comes out of the conveyance roller 41 or the paper discharge roller 43. Therefore, there is a high possibility that the recording paper whose end is lifted and the recording head 21c (particularly, the nozzle) come into contact. Therefore, in this case, the CPU 10 moves (retreats) the carriage 211 to the retreat position selected in S602 or S617 as in the conventional case (S615), and starts discharging the recording paper after the carriage 211 has been retreated. (S616), and this process ends.

  On the other hand, when the CPU 10 determines in S604 that both the transport roller 41 and the paper discharge roller 43 hold the recording sheet (S604: Yes), the CPU 10 determines the position of the carriage 211 at the end of printing (specifically, Obtains the coordinates in the main scanning direction (S605). In the present embodiment, the CPU 10 acquires the reference position (for example, the center) of the carriage 211 at the end of printing in the main scanning direction as the position of the carriage 211 at the end of printing. The position of the carriage 211 is acquired based on the encoder amount of a linear encoder (not shown).

  Next, based on the position acquired in S605 (the position of the carriage 211 at the end of printing), the CPU 10 determines the retraction position movement distance L1 of the carriage 211, that is, the distance that the carriage 211 moves until it reaches the selected retraction position. Calculate (S606). Specifically, the CPU 10 calculates the absolute value of (the position of the carriage 211 at the end of printing−the selected retracted position) as the retracted position moving distance L1. Next, the CPU 10 calculates the retracted position moving time T1 of the carriage 211, that is, the time required for the carriage 211 to reach the selected retracted position (S607). Specifically, the CPU 10 calculates (distance L1 calculated in S606) / (movement speed of the carriage 211) as the retracted position movement time T1 of the carriage 211. In the present embodiment, the “moving speed of the carriage 211” is a fixed value specified in advance, but may be a variable value (for example, a variable value corresponding to the distance L1).

  Next, the CPU 10 calculates the distance L2 until the trailing edge of the sheet is removed, that is, the distance until the trailing edge of the recording sheet is removed from the conveying roller 41 (S608). Specifically, the CPU 10 calculates the absolute value of (recording paper trailing edge position−conveying roller position) as a distance L2 until the trailing edge of the sheet is lost. In this embodiment, the distance obtained by subtracting the length in the conveyance direction of the recording sheet from the conveyance amount after the leading edge of the recording sheet is detected by the registration sensor 21e is referred to as a “recording sheet rear end position”. The distance to the nip position of the transport roller 41 is defined as “transport roller position”. Next, the CPU 10 calculates a time T2 until the trailing edge of the sheet is removed, that is, a time required until the trailing edge of the recording sheet is removed from the conveying roller 41 (S609). Specifically, the CPU 10 calculates (distance L2 calculated in S608) / (recording paper conveyance speed) as the time T2 until the trailing edge of the paper is removed. In this embodiment, the “recording paper conveyance speed” is a fixed value specified in advance, but may be a variable value (for example, a variable value corresponding to the distance L2).

  If (time T2 until the trailing edge of the sheet is removed) ≧ (retraction position moving time T1 of the carriage 211) (S610: Yes), the carriage 211 can be moved to the retracted position while discharging the recording sheet. Before the retreat of 211 is completed, the trailing edge of the recording sheet does not come off from the conveying roller 41, and the recording sheet and the recording head 21c (particularly, the nozzle) do not contact. Therefore, in such a case, the CPU 10 moves the carriage to the selected retraction position while discharging the paper (S611), and ends this processing.

  On the other hand, if (time T2 until the trailing edge of the sheet is removed) <(retraction position moving time T1 of the carriage 211) (S610: No), the CPU 10 calculates (time T1-time T2) as the standby time T3. (S612). Next, the CPU 10 starts to move the carriage 211 to the selected retraction position (S613), and after the waiting time T3 has elapsed from the start of movement of the carriage 211, starts to discharge the recording paper (S614). This process ends. If the time T2 until the trailing edge of the sheet is shorter than the retreat position movement time T1 of the carriage 211, the recording paper discharge start is delayed by (time T1−time T2) from the start of movement of the carriage 211. It is possible to prevent the trailing edge of the recording sheet from coming off from the conveying roller 41 before the carriage 211 is retracted.

  FIG. 7 is a flowchart showing the saving process (S414) at the time of printing the last page described above. In this process, the CPU 10 first determines whether the carriage position at the end of printing is on the right side (reverse direction side) from the paper center position stored in the paper center position memory 12b (S701). In S701, “carriage position at the end of printing” is set as a reference position in the main scanning direction of the carriage 211 at the end of printing, as in S605 described above. In S701, when the CPU 10 determines that the carriage position at the end of printing is on the right side of the paper center position (S701: Yes), the CPU 10 selects the right side retraction position stored in the retraction position memory 12a as the retraction position. (S702). On the other hand, when the CPU 10 determines that the carriage position at the end of printing is on the left side of the paper center position (S701: No), the CPU 10 selects the left retracted position stored in the retracted position memory 12a as the retracted position. (S703). Therefore, after printing the last page on the recording paper, the retracted position closest to the carriage position at the end of printing in S701 to S703 is selected as the retracted position. After the processing of S702 or S703, the CPU 10 executes the processing of S603 to S616 similarly to the above-described saving processing at the time of printing the next page in FIG. 6 and ends this processing.

  FIG. 8 is a flowchart showing the save process (S415) during the above-described back side printing. In this process, the retreat position stored in the retreat position memory 12a is not used, and a retreat position for backside printing provided on the right side (reverse direction side) in the main scanning direction (hereinafter referred to as “dedicated retreat position”). Is used. In this process, the CPU 10 performs the process of S801 instead of the process of S606, performs the process of S802 instead of the process of S611, performs the process of S803 instead of the process of S613, and replaces the process of S615 with S804. Except for performing the above process, the processes of S603 to S616 are executed as in the case of the save process at the time of printing the next page in FIG. Then, after executing S802, S614, or S616, the CPU 10 reverses and feeds the recording sheet by conveying it through the reverse conveying path 37 (S805), and ends this process.

  Specifically, in S801, the CPU 10 calculates the absolute value of (the position of the carriage 211 at the end of printing acquired in S605−the dedicated retract position on the right side) as the retract position movement distance L1 (S801). In the present embodiment, the reference position (for example, the center) of the carriage 211 when the carriage 211 arranges the lever 214a (drive transmission switching mechanism 214) at the second position P2 is referred to as a “dedicated retreat position”. Therefore, the time T1 calculated in S607 is the time required for the carriage 211 at the end of printing to reach the position where the lever 214a is arranged at the second position P2 during the back side printing.

  In S802, the CPU 10 moves the carriage to the right dedicated retract position (that is, the position where the carriage 211 places the lever 214a at the second position P2) while discharging paper (S802). In S803, the CPU 10 starts to move the carriage 211 to the right dedicated retract position (S803). In S804, the CPU 10 moves (retreats) the carriage 211 to the right-side dedicated retreat position (S804). When the lever 214a is disposed at the second position P2, the driving force of the second drive motor 21b is transmitted to the rebound roller 47, whereby the recording sheet is conveyed through the reverse conveyance path 38 by the rotation of the reversal roller 47. Is done. When the recording paper passes through the reverse conveyance path 37, the second surface, which is the back surface of the recorded first surface, becomes the recording surface, and printing on the second surface becomes possible.

  According to the MFP 1 (printer 21) of the present embodiment, when printing on one side of a recording sheet is completed, the recorded recording sheet is sandwiched between both the transport roller 41 and the discharge roller 43. Moves the carriage 211 to a predetermined retreat position while transporting the recorded recording paper. When the recording paper is sandwiched between both the transport roller 41 and the paper discharge roller 43, there is almost no possibility that the recording paper will float between the transport roller 41 and the paper discharge roller 42. Therefore, even if the recording paper is conveyed and the carriage 211 is retracted at the same time, the contact between the recording paper and the recording head 21c (particularly the nozzle) can be prevented. Therefore, since the carriage 211 (recording head 21c) is moved to the retracted position while transporting the recording paper, the recording paper transport is stopped while the carriage 211 is moved to the retracted position as in the prior art. Throughput for printing can be improved. In particular, based on a comparison between (retraction position moving time T1 of carriage 211) and (time T2 until the trailing edge of the sheet is removed), the trailing edge of the recording sheet is moved from the transport roller 41 before the carriage 211 is retracted. Since the timing of starting the movement of the carriage to the retracted position and the timing of starting the discharge of the recorded recording paper are controlled so as not to come off, the throughput related to printing is prevented while preventing contact between the recording paper and the recording head 21c. Can be improved.

  If there is a recording sheet for the next page to be recorded, the retreat position closest to the printing start position for the next page is selected, so printing on the recording sheet for the next page is performed without moving the carriage 211 unnecessarily. Can start. On the other hand, in double-sided printing, the retracted position of the carriage 211 after printing on the first surface is the position at which the carriage 211 places the lever 214a at the second position P2, so that the recording paper can be used without wastefully moving the carriage 211. Can be conveyed in the reverse conveyance path 38 to change the recording surface to the second surface. By preventing unnecessary movement of the carriage 211 in continuous printing or double-sided printing on a plurality of recording papers, the printing throughput can also be improved in this respect. In addition, after the recording paper of the last page is printed, the retract position closest to the position of the carriage 211 at the end of printing is selected, so that the time required for the retract operation of the carriage 211 can be minimized. In this case, it is possible to improve the throughput related to printing.

  In the retreat position candidate acquisition process (S405), the retreat position candidates are determined based on the positions of both ends of the recording sheet detected by the media sensor 21d. Therefore, the retreat position is variable according to the positions of both ends. Can be set appropriately. Therefore, it is possible to prevent the retracted position from being unnecessarily separated from the end of the recording paper in the main scanning direction. Further, since the process of S405 is executed every time the paper feed tray 31 is detached, even if the size of the recording paper stored in the paper feed tray 31 changes, a retreat position suitable for the changed size can be acquired. .

  In addition, when the type of recording paper to be printed is a recording paper (for example, glossy paper) that tends not to be lifted, the carriage 211 is not retracted. Can be improved.

  In each of the above embodiments, the MFP 1 is an example of an ink jet recording apparatus. The conveyance roller 41 is an example of a first conveyance unit and a first conveyance roller. The recording head 21c is an example of a recording unit and a recording head. The paper discharge roller 43 is an example of a second transport unit and a second transport roller. The CPU 10 that executes the process of S604 is an example of a determination unit. The CPU 10 that executes the processes of S611, S614, and S802 is an example of the save control unit. The registration sensor 21e is an example of a detection unit. CPU10 which performs S603 is an example of a conveyance amount acquisition part. The CPU 10 that executes the process of S605 is an example of a recording unit position acquisition unit. The CPU 10 that executes the process of S610 is an example of a second determination unit. The reverse conveyance path 38 is an example of the reverse path. The drive transmission switching mechanism 214 is an example of a switching mechanism. CPU10 which performs the process of S410 is an example of a kind specific | specification part. The CPU 10 that executes the process of S416 is an example of a paper discharge control unit. The CPU 10 that executes the processes of S503 and S504 is an example of a retreat position candidate acquisition unit. The RAM 12 is an example of a storage unit. The CPU 10 that executes the process of S505 is an example of a storage control unit. The CPU 10 is an example of a control unit.

  Although the present invention has been described based on the embodiments, 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 the above-described embodiment, the MFP 1 having functions other than the printing function has been described as an example of the inkjet recording apparatus. However, an inkjet printer specialized for the printing function can also be an example of the inkjet recording apparatus. In the above embodiment, the present invention is applied when the MFP 1 performs printing based on the pass data received from the PC 500. However, the present invention can be applied if the printer 21 performs printing. For example, the present invention may be applied to a case where scan data from the scanner 20 is printed by the printer 21 (that is, a copy function is executed). In such a case, values set as print settings in the flash memory 11 may be used for the size and type of the recording paper.

  In the above embodiment, the registration sensor 21e detects the leading edge of the recording paper (the downstream edge in the recording paper conveyance direction) to determine whether both the conveyance roller 41 and the paper discharge roller 43 are holding the recording paper. And the length of the recording paper in the conveyance direction. Instead, whether or not both the conveyance roller 41 and the paper discharge roller 43 sandwich the recording sheet based on the conveyance amount from the rear end of the recording sheet (upstream end in the recording sheet conveyance direction) by the registration sensor 21e. It is good also as a structure which judges whether. Specifically, when the conveyance amount after the registration sensor 21e detects the trailing edge of the recording sheet is shorter than the distance from the detection position by the registration sensor 21e to the nip position of the conveyance roller 41, the CPU 10 determines that the conveyance roller 41 is the recording sheet. Is determined to be sandwiched. On the other hand, if the former transport amount is longer than the latter distance, the CPU 10 determines that the transport roller 41 does not pinch the recording paper. Further, the distance obtained by adding the length in the conveyance direction of the recording paper to the conveyance amount after the trailing edge of the recording paper is detected by the registration sensor 21e is based on the distance from the detection position by the registration sensor 21e to the nip position of the paper discharge roller 43. If it is long, the CPU 10 determines that the paper discharge roller 43 holds the recording paper. On the other hand, if the former transport amount is shorter than the latter distance, the CPU 10 determines that the paper discharge roller 43 does not pinch the recording paper.

  Further, based on the transport amount after the registration sensor 21e detects the leading edge of the recording paper, it is determined whether or not the leading edge of the recording paper is pinched by the paper discharge roller 43, and the registration sensor 21e detects the trailing edge of the recording paper. Based on the detected conveyance amount, it is determined whether or not the trailing edge of the recording sheet is nipped by the conveyance roller 41. Based on these determinations, both the conveyance roller 41 and the discharge roller 43 perform recording. It may be configured to determine whether or not a sheet is sandwiched. In such a modification, the determination is made without using the length in the conveyance direction of the recording paper, so even if the size of the recording paper received from the PC 500 is different from the actual size of the recording paper, the conveyance roller 41 and It is possible to appropriately determine whether or not both of the paper discharge rollers 43 are holding the recording paper.

  In the above embodiment, the CPU 10 determines whether or not the leading edge of the recording paper is pinched by the paper discharge roller 43 and whether or not the trailing edge of the recording paper is pinched by the transport roller 41. Based on this, it is determined whether or not both the conveyance roller 41 and the paper discharge roller 43 are holding the recording paper. Instead, the CPU 10 determines whether both the conveyance roller 41 and the paper discharge roller 43 are nipping the recording sheet based on the determination result of whether the trailing edge of the recording sheet is nipped by the conveyance roller 41. It may be judged. Specifically, when the CPU 10 determines that the trailing edge of the recording sheet is nipped by the conveying roller 41, the CPU 10 determines that both the conveying roller 41 and the paper discharge roller 43 are nipping the recording sheet, When it is determined that the trailing edge of the recording sheet is not sandwiched between the conveyance rollers 41, it may be determined that both the conveyance roller 41 and the discharge roller 43 are not sandwiching the recording sheet. For example, in an apparatus configured such that a recording sheet is always held between the discharge rollers 43 when recording on one surface is completed when the distance between the recording head 21c and the discharge rollers 43 in the transport direction is short. ,It is valid.

  In the above-described embodiment, one retreat position candidate is provided on the left and right sides of the recording paper passage area, but one or more candidates may be provided on each side. When a plurality of retreat position candidates are provided on each side, the retreat position closest to the recording paper passage area is first selected, and then, for example, the retreat position selected during retraction of the carriage 211 is inappropriate. If it is determined that there is, the retreat destination may be switched to a retreat position next to the recording paper passage area. Moreover, it is good also as a structure which provides the candidate of one or several retraction positions in any one of the right.

  In the above embodiment, in the retreat position candidate acquisition process (S405), the retreat position candidates are acquired based on the positions of both ends of the recording paper. However, the retreat position candidates are set in advance according to the size of the recording paper. Therefore, the retreat position may be selected from candidates corresponding to the size of the recording sheet received from the PC 500. However, it is preferable to acquire the retreat position candidates based on the positions of both ends of the recording paper because a retreat position suitable for the actual size of the recording paper can be set.

  In the above embodiment, even when time T1 = time T2, the CPU 10 is configured to execute S611 or S802. However, the condition for causing the CPU 10 to execute S611 or S802 may be at least time T1> time T2.

  In the above embodiment, the “dedicated retreat position” is the reference position of the carriage 211 when the carriage 211 places the lever 214a at the second position P2, but the position at which the lever 214a is moved to the second position P2. Therefore, the reference position of the carriage 211 at the position on the recording paper passing area side may be set as the “dedicated retraction position”. However, when the carriage 211 places the lever 214a at the second position P2, the position of the carriage 211 that places the lever 214a at the second position P2 is the reference position of the carriage 211 that is the “dedicated retraction position”. And the retracted position of the carriage 211, which is preferable.

  In the above embodiment, when there is a next page, the save process (S413) at the time of printing the next page is executed. However, in this case, the save process (S414) at the time of printing the final page may be executed. . In the above-described embodiment, the back-end printing save process (S415) is executed when double-sided printing is followed by back-side printing. In such a case, the save process at the time of final page printing (S414) is performed. ) May be executed.

  In the above-described embodiment, the CPU 10 has been described as a configuration that executes each process of FIGS. 4 to 8. However, instead of the CPU 10, the ASIC 24 may execute each process of FIGS. 4 to 8. Moreover, it is good also as a structure which CPU10 and ASIC24 cooperate and perform each process of FIGS.

1 MFP
11a Control program

Claims (12)

A first transport unit that transports the recording medium in the transport direction while sandwiching the recording medium;
A plurality of inks that are provided on the downstream side of the first transport unit in the transport direction and eject ink onto the recording medium transported to the first transport unit while moving in a main scanning direction orthogonal to the transport direction. A recording unit having a nozzle;
A second transport unit that is provided downstream of the recording unit in the transport direction and transports the recording medium in the transport direction while sandwiching a recording medium;
A determination unit that determines whether the recording medium is sandwiched between the first transport unit and the second transport unit when recording by the recording unit on the recording medium is completed;
When the determination unit determines that the recording medium is sandwiched between the first conveyance unit and the second conveyance unit, the recording medium is conveyed to the first conveyance unit and the second conveyance unit. A retraction control unit that moves the recording unit to a predetermined retraction position in the main scanning direction, while transporting it downstream in the direction;
With
The predetermined evacuation position is a position where the nozzle is disposed in an area outside the area where the recording medium is conveyed by the first conveyance unit and the second conveyance unit in the main scanning direction. An ink jet recording apparatus. A detection unit that is provided upstream of the first conveyance unit in the conveyance direction and outputs a signal based on conveyance of an end of the recording medium in the conveyance direction;
A conveyance amount acquisition unit for acquiring a conveyance amount of a recording medium;
With
The determination unit, based on the transport amount of the recording medium acquired by the transport amount acquisition unit after the detection unit outputs a signal based on the transport of the downstream end of the recording medium in the transport direction, Determining whether the recording medium is sandwiched between the first transport unit and the second transport unit;
The evacuation control unit determines that the recording medium is not sandwiched between the first transport unit and the second transport unit when the recording unit completes recording on the recording medium. The recording unit is moved to a predetermined retraction position in the main scanning direction while waiting for conveyance of the recording medium to the downstream side in the conveyance direction, and the recording unit has reached the retraction position. 2. The ink jet recording apparatus according to claim 1, wherein the recording medium is transported downstream in the transport direction by the second transport unit as a condition. A detection unit that is provided upstream of the first conveyance unit in the conveyance direction and outputs a signal based on conveyance of an end of the recording medium in the conveyance direction;
A conveyance amount acquisition unit for acquiring a conveyance amount of a recording medium;
With
The determination unit is based on the conveyance amount of the recording medium acquired by the conveyance amount acquisition unit after the detection unit outputs a signal based on the conveyance of the upstream end in the conveyance direction of the recording medium. The inkjet recording apparatus according to claim 1, wherein it is determined whether the recording medium is sandwiched between the first transport unit and the second transport unit. A recording unit position acquisition unit that acquires the position of the recording unit in the main scanning direction when recording by the recording unit on the recording medium is completed;
When the determination unit determines that the recording medium is sandwiched between the first conveyance unit and the second conveyance unit, the detection unit outputs a signal and is acquired by the conveyance amount acquisition unit. Based on the transport amount of the recording medium and the position of the recording unit acquired by the recording unit position acquisition unit, the upstream end in the transport direction of the recording medium is not sandwiched by the first transport unit A second determination unit that determines whether a first time that is a time until the second recording time is equal to or longer than a second time that is a time for moving the recording unit from the acquired position to the predetermined retraction position; Prepared,
The evacuation control unit
When the second determination unit determines that the first time is equal to or longer than the second time, the recording medium is transported downstream in the transport direction by the first transport unit and the second transport unit. The inkjet recording apparatus according to claim 2, wherein the recording unit is moved to the predetermined retreat position. A recording unit position acquisition unit that acquires the position of the recording unit in the main scanning direction when recording by the recording unit on the recording medium is completed;
When the determination unit determines that the recording medium is sandwiched between the first conveyance unit and the second conveyance unit, the detection unit outputs a signal and is acquired by the conveyance amount acquisition unit. Based on the transport amount of the recording medium and the position of the recording unit acquired by the recording unit position acquisition unit, the upstream end in the transport direction of the recording medium is not sandwiched by the first transport unit A second determination unit that determines whether a first time that is a time until the second recording time is equal to or longer than a second time that is a time for moving the recording unit from the acquired position to the predetermined retraction position; Prepared,
The evacuation control unit
When the second determination unit determines that the first time is not equal to or longer than the second time, the recording unit starts to move to the predetermined retraction position, and from the start (the second time-the second time) After the first time period has elapsed, the recording medium is transported downstream in the transport direction by the first transport section and the second transport section while moving the recording section to the predetermined retreat position. The ink jet recording apparatus according to claim 2, wherein the ink jet recording apparatus is provided. In the main scanning direction, at least one retreat position is provided on each of the one side and the other side across an area where the recording medium is transported by the first or second transport unit.
Based on the position of the recording unit acquired by the recording unit position acquisition unit, the retraction position closest to the position of the recording unit among the retraction positions provided on the one side and the other side is the predetermined position. The inkjet recording apparatus according to claim 1, wherein the inkjet recording apparatus is a retracted position.   After recording on the recording medium by the recording unit, when recording on the next recording medium by the recording unit is performed, the recording medium is transported by the first or second transport unit. A position at which the nozzle is disposed in a region deviated from the region to be recorded, and a retraction position provided on the side where recording on the next recording medium is started by the recording unit in the main scanning direction, 6. The ink jet recording apparatus according to claim 1, wherein the ink jet recording apparatus has a predetermined retreat position. When performing double-sided printing, after recording on the first surface of the recording medium by the recording unit, the recording surface of the recording medium is set so that the recording surface becomes the second surface which is the back surface of the first surface. An inversion path to invert,
A switching mechanism capable of switching a passage path of a recording medium according to the position of the recording unit on one end side of the moving range of the recording unit in the main scanning direction, wherein the recording unit is set to a first position on the one end side. A switching mechanism that, when disposed, has a reversing path as a passing path of a recording medium on which recording by the recording unit has been completed,
When recording by the recording unit is completed on the first surface of the recording medium in double-sided printing, the nozzle is located in a region outside the region where the recording medium is transported by the first or second transport unit. The retreat position provided on the side where the first position in the main scanning direction is located is set as the predetermined retreat position. Inkjet recording apparatus.   9. The ink jet recording apparatus according to claim 8, wherein the retracted position is a position when the recording unit is in the first position. A type identifying unit for identifying the type of recording medium;
When the type specified by the type specifying unit is a type other than the type specified in advance as being easy to float during conveyance, when the recording by the recording unit is completed on the recording medium, the recording unit is A paper discharge control unit that discharges paper without moving it to a predetermined retraction position,
The evacuation control unit is a type that is specified in advance as the type specified by the type specifying unit as being easily lifted during transport, and the recording unit determines that the recording medium is the first transport unit and When it is determined that the recording medium is sandwiched between the second transport section, the recording section is moved to the downstream side in the transport direction by the first transport section and the second transport section while the recording section is The inkjet recording apparatus according to claim 1, wherein the inkjet recording apparatus is moved to a retracted position. Each time the storage section for storing the recording medium for recording by the recording section is opened, the position of both ends in the main scanning direction of the area of the recording medium transported by the first or second transport section is determined. A retreat position candidate determining unit for determining the retreat position candidate;
11. The inkjet recording apparatus according to claim 1, further comprising: a storage control unit configured to store a storage position candidate determined by the storage position candidate determination unit in a storage unit. A first transport roller for transporting the recording medium in the transport direction while sandwiching the recording medium;
A recording head provided on the downstream side of the first transport roller in the transport direction and having a plurality of nozzles for discharging ink;
A second transport roller provided downstream of the recording head in the transport direction, for transporting in the transport direction while sandwiching a recording medium;
A control unit,
The controller is
Causing the recording medium to be transported in the transport direction by at least one of the first transport roller or the second transport roller;
While moving the recording head in the main scanning direction orthogonal to the transport direction, ink is ejected from the nozzles to the recording medium, and an image is recorded.
When recording by the recording head on the recording medium is completed, it is determined whether the recording medium is sandwiched between the first transport roller and the second transport roller;
When it is determined that the recording medium is sandwiched between the first conveyance roller and the second conveyance roller, the recording medium is conveyed downstream in the conveyance direction by the first conveyance roller and the second conveyance roller. While moving the recording head to a predetermined retracted position in the main scanning direction,
The predetermined evacuation position is a position where the nozzle is disposed in an area outside the area where the recording medium is conveyed by the first conveyance roller and the second conveyance roller in the main scanning direction. An ink jet recording apparatus.

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