JP6303524B2 - Inkjet recording apparatus and inkjet recording method - Google Patents

Description

  The present invention relates to an ink jet recording apparatus that records an image on a sheet formed into a wave shape in a main scanning direction.

  2. Description of the Related Art Conventionally, an ink jet recording apparatus that records an image by discharging ink onto a sheet is known. Some ink jet recording apparatuses include a waveform forming mechanism that forms a sheet into a wave shape in a main scanning direction that intersects the conveyance direction of the sheet. For example, in Patent Document 1, a sheet is sandwiched between a platen on which irregularities are formed and a paper pressing plate disposed so as to face the platen, thereby forming the sheet into a wave shape.

JP-A-9-48161

  The shape of the paper formed into a wave shape by the waveform forming mechanism varies depending on the direction of the fibers constituting the paper. Therefore, when the fiber direction assumed by the ink jet recording apparatus is different from the fiber direction of the paper actually set in the ink jet recording apparatus, the image recording quality may be deteriorated.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an ink jet recording apparatus that suppresses a decrease in image recording quality caused by the direction of fibers constituting a sheet.

  (1) An ink jet recording apparatus according to the present invention includes a transport unit that transports paper in a transport direction and a recording head that ejects ink onto the paper transported by the transport unit, and performs main scanning that intersects the transport direction. A carriage that reciprocates in the direction, a carriage sensor that outputs a detection signal corresponding to the position of the carriage in the main scanning direction, and a peak that protrudes toward the recording head in the shape of the sheet facing the recording head. A waveform forming mechanism for forming a wave shape in which a plurality of positions and valley bottom positions protruding in a direction away from the recording head are alternately arranged in the main scanning direction, and a plurality of which is assumed that the carriage faces the peak position of the sheet The information indicating the detection signal at the assumed peak position and the carriage assumed to face the valley position of the paper. Comprising of the assumed root storage unit in which information indicating the detection signal is stored in the position, and a control unit. The control unit generates a pattern image in which the distance in the main scanning direction between the first image recorded by the forward scanning of the carriage and the second image recorded by the backward scanning of the carriage differs in the transport direction. The pattern recording process for recording on the first sheet in the summit section including the assumed peak position and the valley section including the assumed valley position, and the position on the first sheet where the first image and the second image overlap. A first distance between the recording head and the first sheet at the assumed peak position, and a second distance between the recording head and the first sheet at the assumed valley position. An acquisition process for acquiring information indicating an image, a reception process for receiving a recording instruction including image data, and ink discharge to the recording head in the course of moving the carriage in the main scanning direction. The recording process for recording the image indicated by the image data on the second sheet is performed by alternately repeating the ejection process to be performed and the conveying process for conveying the second sheet to the conveying unit by a predetermined line feed width. . Then, in the recording process, the control unit operates the recording head and the transport unit under a first condition in response to a difference between the first distance and the second distance being equal to or greater than a threshold value. In response to the difference between the one distance and the second distance being less than the threshold value, the recording head and the transport unit are operated under a second condition different from the first condition.

  (2) An ink jet recording method according to the present invention includes a transport unit that transports a sheet in a transport direction, and a recording head that ejects ink onto the sheet transported by the transport unit, and performs main scanning that intersects the transport direction. A carriage that reciprocates in the direction, a carriage sensor that outputs a detection signal corresponding to the position of the carriage in the main scanning direction, and a peak that protrudes toward the recording head in the shape of the sheet facing the recording head. A waveform forming mechanism for forming a wave shape in which a plurality of positions and valley bottom positions protruding in a direction away from the recording head are alternately arranged in the main scanning direction, and a plurality of which is assumed that the carriage faces the peak position of the sheet The information indicating the detection signal at the assumed peak position and the carriage assumed to face the valley position of the paper. And assuming root position storage unit in which information indicating the detection signal is stored in a method for recording an image on a sheet by the inkjet recording apparatus comprising: a control unit. In the inkjet recording method, a pattern image in which a distance in the main scanning direction between the first image recorded by the forward scanning of the carriage and the second image recorded by the backward scanning of the carriage is different in the transport direction. A pattern recording step in which the first image and the second image overlap each other in a peak section including the assumed peak position and a valley section including the assumed valley position, and the position on the first sheet where the first image and the second image overlap. And a second distance between the recording head and the first sheet at the assumed valley bottom position, and a first distance between the recording head and the first sheet at the assumed peak position. An acquisition step of acquiring information indicating distance, a reception step of receiving a recording instruction including image data, and a process of moving the carriage in the main scanning direction The image indicated by the image data is recorded on the second sheet by alternately repeating an ejection step for ejecting ink to the recording head and a conveyance step for conveying the second sheet to the conveyance unit by a predetermined line feed width. Recording step. Then, in the ink jet recording method, in the recording step, the recording head and the transport unit are operated under a first condition according to a difference between the first distance and the second distance being equal to or greater than a threshold value, In response to the difference between the first distance and the second distance being less than the threshold value, the recording head and the transport unit are operated under a second condition different from the first condition.

  According to the present invention, according to the difference between the first distance and the second distance specified by the position where the pattern images overlap, the first condition suitable for the vertically conveyed paper and the horizontally conveyed paper The recording process is executed by switching to a suitable second condition. Thereby, it is possible to obtain an ink jet recording apparatus that suppresses a decrease in image recording quality due to the direction of fibers constituting the paper.

FIG. 1 is an external perspective view of the multifunction machine 10. FIG. 2 is a longitudinal sectional view schematically showing the internal structure of the printer unit 11. FIG. 3 is a plan view of the carriage 23 and the guide rails 43 and 44. FIG. 4 is a cross-sectional view showing the positional relationship between the support rib 52 of the platen 42 and the contact rib 85 of the contact member 80. FIG. 5 is a block diagram of the printer unit 11. FIG. 6 is an example of information stored in the EEPROM 134. FIG. 7 is a flowchart of the paper type setting process. FIG. 8 is an example of a pattern image 90 recorded on the paper 12. FIG. 9 is a flowchart of the image recording process. FIG. 10 is a flowchart of the discharge process. FIG. 11 is a flowchart of the conveyance process. FIG. 12 is an example of a pattern image 110 recorded on the paper 12.

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

[Overall configuration of MFP 10]
As shown in FIG. 1, the multifunction machine 10 is formed in a substantially rectangular parallelepiped. The multifunction machine 10 includes a printer unit 11 that records an image on a sheet 12 (see FIG. 2) by an inkjet recording method. The multifunction machine 10 may include a scanner unit (an example of a reading unit) that reads an image recorded on a sheet and generates image data. Further, the multifunction machine 10 has various functions such as a facsimile function and a print function. As shown in FIG. 2, the printer unit 11 includes a feeding unit 15, a feeding tray 20, a discharge tray 21, a transport roller unit 54, a recording unit 24, a discharge roller unit 55, and a platen 42. The contact member 80 is provided. The multifunction machine 10 is an example of an ink jet recording apparatus. The feeding unit 15, the conveyance roller unit 54, and the discharge roller unit 55 are examples of the conveyance unit.

[Feed tray 20, discharge tray 21]
The feeding tray 20 is inserted and removed in the front-rear direction 8 through an opening 13 (see FIG. 1) formed on the front surface of the printer unit 11. A plurality of sheets of paper 12 fed to the transport path 65 by the feeding unit 15 can be supported on the feeding tray 20. The discharge tray 21 is disposed on the upper side of the feeding tray 20. The discharge tray 21 supports the paper 12 discharged by the discharge roller unit 55 through the opening 13 formed on the front surface.

[Feeding unit 15]
As shown in FIG. 2, the feeding unit 15 includes a feeding roller 25, a feeding arm 26, and a shaft 27. The feeding roller 25 is rotatably supported on the leading end side of the feeding arm 26. The feed roller 25 rotates in a direction (that is, normal rotation) in which the paper 12 is conveyed in the conveyance direction 16 by reverse rotation driving of the conveyance motor 102 (see FIG. 5). The feeding arm 26 is rotatably supported on a shaft 27 supported by the frame of the printer unit 11. The feeding arm 26 is urged to rotate toward the feeding tray 20 by its own weight or an elastic force by a spring or the like.

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

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

[Discharge roller section 55]
As shown in FIG. 2, the discharge roller portion 55 is disposed downstream of the recording portion 24 in the transport direction 16. The discharge roller portion 55 includes a discharge roller 62 and a spur 63 that face each other. The discharge roller 62 is driven by the transport motor 102. The spur 63 is rotated along with the rotation of the discharge roller 62. The paper 12 is nipped by the discharge roller 62 and the spur 63 that are rotated forward by the normal driving of the conveyance motor 102 and is conveyed in the conveyance direction 16. The discharge roller unit 55 is an example of a second transport roller unit.

[Registration sensor 120]
As shown in FIG. 2, the printer unit 11 includes a registration sensor 120 on the upstream side in the transport direction 16 from the transport roller unit 54. The registration sensor 120 is a sensor for detecting that the paper 12 exists at the installation position of the registration sensor 120. The registration sensor 120 outputs a low level signal that is a detection signal (that is, a “signal whose signal level is less than the threshold”) to the control unit 130 described later in response to the presence of the sheet 12 at the installation position. On the other hand, the registration sensor 120 outputs a high level signal that is a detection signal (that is, a “signal level equal to or higher than a threshold value”) to the control unit 130 in response to the fact that the sheet 12 is not present at the installation position.

[Rotary encoder 121]
Further, as shown in FIG. 5, the printer unit 11 includes a known rotary encoder 121 that generates a pulse signal in accordance with the rotation of the transport roller 60 (in other words, the rotational drive of the transport motor 102). The rotary encoder 121 includes an encoder disk and an optical sensor. The encoder disk rotates with the rotation of the transport roller 60. The optical sensor reads the rotating encoder disk to generate a pulse signal, and outputs the generated pulse signal to the control unit 130.

[Recording unit 24]
As shown in FIG. 2, the recording unit 24 is disposed between the conveyance roller unit 54 and the discharge roller unit 55 in the conveyance direction 16. The recording unit 24 is disposed so as to face the platen 42 in the vertical direction 7. The recording unit 24 includes a carriage 23, a recording head 39, an encoder sensor 38 </ b> A, and a media sensor 122. Further, as shown in FIG. 3, an ink tube 32 and a flexible flat cable 33 are extended from the carriage 23. The ink tube 32 supplies ink from the ink cartridge to the recording head 39. The flexible flat cable 33 electrically connects the control board on which the control unit 130 is mounted and the recording head 39.

  As shown in FIG. 3, the carriage 23 is supported by guide rails 43 and 44 that extend in the left-right direction 9 at positions spaced in the front-rear direction 8. The carriage 23 is moved by a known belt mechanism provided on the guide rail 44. The belt mechanism is wound around the drive pulley 47 provided at one end of the guide rail 44 in the left-right direction 9, the driven pulley 48 provided at the other end, the drive pulley 47 and the driven pulley 48, and coupled to the carriage 23. And an endless annular belt 49. As the driving pulley 47 rotated by the driving force of the carriage motor 103 (see FIG. 5) causes the belt 49 to move around, the carriage 23 reciprocates in the left-right direction 9 (an example of the main scanning direction). The carriage 23 moves in the FWD direction from the right end toward the left end when the carriage motor 103 rotates forward, and moves in the RVS direction from the left end toward the right end when the carriage motor 103 rotates in the reverse direction.

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

  Further, as shown in FIG. 3, a belt-like encoder strip 38 </ b> B extending in the left-right direction 9 is disposed on the guide rail 44. The encoder sensor 38A is mounted on the lower portion of the carriage 23 at a position facing the encoder strip 38B. In the process of moving the carriage 23, the encoder sensor 38 </ b> A reads the encoder strip 38 </ b> B to generate a pulse signal, and outputs the generated pulse signal to the control unit 130. The encoder sensor 38A and the encoder strip 38B constitute the carriage sensor 38 shown in FIG. The pulse signal output from the carriage sensor 38 is an example of a detection signal corresponding to the position of the carriage 23.

[Platen 42]
As illustrated in FIG. 2, the platen 42 is disposed between the transport roller unit 54 and the discharge roller unit 55 in the transport direction 16. The platen 42 is disposed so as to face the recording unit 24 in the vertical direction 7. As shown in FIG. 4, a plurality of support ribs 52 that protrude upward and extend in the front-rear direction 8 are formed on the upper surface of the platen 42. The plurality of support ribs 52 are arranged at predetermined intervals in the left-right direction 9. The sheet 12 is supported by the platen 42, specifically, a plurality of support ribs 52 formed on the upper surface of the platen 42. Further, the light reflectance of the platen 42 in the present embodiment is set lower than that of the paper 12.

[Abutting member 80]
As shown in FIG. 2, the contact member 80 is provided on the upstream side in the transport direction 16 with respect to the recording head 39 in the transport path 65. As shown in FIG. 4, the contact member 80 is provided at a plurality of locations separated in the left-right direction 9. The distance between the lower surface of the contact member 80 and the platen 42 is narrower than the distance between the lower surface of the recording head 39 and the platen 42. In addition, on the lower surface of each contact member 80, a contact rib 85 protruding downward is provided. The contact rib 85 contacts the upper surface of the paper 12 supported by the platen 42. Accordingly, the sheet 12 is pressed toward the lower side (that is, the platen 42) by the contact member 80. The position of the contact rib 85 in the transport direction 16 corresponds to the waveform forming position B shown in FIG.

  Here, as shown in FIG. 4, each contact member 80 is positioned between the plurality of support ribs 52 adjacent in the left-right direction 9. In other words, each support rib 52 is located between the adjacent contact members 80 in the left-right direction 9. That is, the contact ribs 85 and the support ribs 52 are alternately arranged in the left-right direction 9. Each support rib 52 protrudes to the upper side of the lower end of the contact rib 85. More specifically, each support rib 52 comes into contact with the paper 12 at a position closer to the recording head 39 than the contact position between the contact rib 85 and the paper 12.

  As a result, the paper 12 between the platen 42 and the contact member 80 (that is, the paper 12 at a position facing the recording head 39) is in a undulated state as viewed from the upstream side or the downstream side in the transport direction 16. Specifically, the shape of the sheet 12 facing the recording head 39 is such that the peak position 12A protruding in a direction approaching the recording head 39 and the valley bottom position 12B protruding in a direction away from the recording head 39 alternate in the left-right direction 9. Are formed in a plurality of wave shapes. More specifically, the peak position 12A is a boundary where the distance between the recording head 39 and the paper 12 starts to decrease and increases. Further, the valley bottom position 12B is a boundary where the interval between the recording head 39 and the paper 12 turns from increasing to decreasing.

  The tip of the abutment rib 85 (the end on the downstream side in the transport direction 16) is an example of the waveform forming position of the present invention, and is positioned between the transport roller unit 54 and the recording head 39 in the transport direction 16. ing. Further, the contact member 80 and the support rib 52 constitute an example of the waveform forming mechanism of the present invention. That is, the waveform forming mechanism forms the paper 12 into a wave shape at the waveform forming position B.

[Media sensor 122]
The media sensor 122 is mounted on the lower portion of the carriage 23 as shown in FIG. The media sensor 122 is a reflective sensor that outputs a detection signal corresponding to the amount of received reflected light. Specifically, the media sensor 122 includes a light emitting unit and a light receiving unit. The light emitting unit irradiates the platen 42 with the amount of light instructed by the control unit 130. The light emitted from the light emitting unit is reflected by the platen 42 or the paper 12 supported by the platen 42, and the reflected light is received by the light receiving unit. The media sensor 122 outputs a detection signal corresponding to the amount of light received by the light receiving unit to the control unit 130. For example, the media sensor 122 outputs a detection signal having a higher level to the control unit 130 as the amount of received light is larger.

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

[Operation unit 17]
The operation unit 17 is an input interface that receives an instruction input to the multifunction machine 10 from a user. Although the specific structure of the operation part 17 is not specifically limited, For example, you may have the touch sensor superimposed on the display screen of the display part 14. FIG. That is, the display unit 14 may be configured as a touch panel display. For the touch sensor, a known method such as a capacitance method or a resistance film method can be adopted. And the operation part 17 may detect selection of the option displayed on the tap position among the options (for example, button etc.) displayed on the display part 14. FIG. The operation unit 17 may have a plurality of push buttons.

[Control unit 130]
As shown in FIG. 5, the control unit 130 includes a CPU 131, a ROM 132, a RAM 133, an EEPROM 134, and an ASIC 135, which are connected by an internal bus 137. The ROM 132 stores a program for the CPU 131 to control various operations. The RAM 133 is used as a storage area for temporarily recording data and signals used when the CPU 131 executes the program, or as a work area for data processing. The EEPROM 134 stores settings, flags, and the like that should be retained even after the power is turned off.

  A transport motor 102 and a carriage motor 103 are connected to the ASIC 135. The ASIC 135 acquires a drive signal for rotating each motor from the CPU 131, and outputs a drive current corresponding to the drive signal to each motor. Each motor is driven forward or reversely by a drive current from the ASIC 135. For example, the control unit 130 controls the driving of the transport motor 102 to drive each roller. Further, the control unit 130 controls the drive of the carriage motor 103 to reciprocate the carriage 23. The control unit 130 controls the recording head 39 to eject ink from the nozzles 40.

  In addition, a carriage sensor 38, a registration sensor 120, a rotary encoder 121, and a media sensor 122 are connected to the ASIC 135. The control unit 130 detects the position of the carriage 23 based on the pulse signal output from the carriage sensor 38. Further, the control unit 130 detects the position of the paper 12 based on the detection signal output from the registration sensor 120 and the pulse signal output from the rotary encoder 121. Further, the control unit 130 detects the end position of the sheet 12 in the left-right direction 9 based on the detection signal output from the media sensor 122.

  For example, as shown in FIG. 6, the EEPROM 134 stores a carriage sensor value, a first discharge timing correction value, and a second discharge timing correction value for each of a plurality of assumed peak positions and a plurality of assumed valley positions. ing. In addition, among the symbols (P, E, X, Y) shown in FIG. 6, a symbol with an odd number added at the end indicates that it is a value associated with an assumed valley bottom position or a valley bottom position, A symbol with an even number at the end indicates that it is an assumed peak position or a value associated with the peak position. The EEPROM 134 is an example of a storage unit.

  The assumed peak position is, for example, the position in the left-right direction 9 of the media sensor 122 assumed to face the peak position of the corrugated paper 12. In other words, the assumed peak position is a position corresponding to the support rib 52 in the left-right direction 9. The assumed valley bottom position is, for example, the position in the left-right direction 9 of the media sensor 122 that is assumed to face the valley position of the corrugated paper 12. In other words, the assumed valley bottom position is a position corresponding to the contact rib 85 in the left-right direction 9. Each assumed peak position and each assumed valley position are stored in the EEPROM 134 as the carriage sensor value E (enc). The carriage sensor value E (enc) is, for example, an encoder value (for example, the number of pulse signals based on one end in the left-right direction 9) output from the carriage sensor 38 at the assumed peak position or the assumed valley position. is there.

  The first ejection timing correction value X is a value for calculating the ejection timing at which the recording head 39 ejects ink to land on each peak position and each valley bottom position of the sheet 12 conveyed in the vertical direction. The second ejection timing correction value Y is a value for calculating the ejection timing at which the recording head 39 ejects ink landed on each peak position and each valley bottom position of the sheet 12 conveyed in the horizontal direction. The first ejection timing correction value X and the second ejection timing correction value Y represent a deviation amount with respect to the reference value D0 of the ejection timing. The first ejection timing correction value X and the second ejection timing correction value Y in the present embodiment are both numerical values of 0 or more representing time. Note that longitudinal conveyance refers to conveying the paper 12 in a state where the direction of the fibers is along the conveyance direction 16. Transverse transport refers to transporting the paper 12 in a state where the fiber direction intersects the transport direction 16.

  The reference value D0 is, for example, an ejection timing for causing ink to land at an intermediate position between the adjacent peak position 12A and valley position 12B in the vertical direction 7 (that is, the facing direction of the recording head 39 and the paper 12). This is the value shown. The reference value D0 indicates, for example, that the ink landed at the intermediate position should be ejected D0 seconds before the recording head 39 reaches just above the intermediate position. The reference value D0 is stored in the EEPROM 134, for example.

  In addition, as shown in FIG. 6, the EEPROM 134 has areas for storing superimposed pattern identifiers at each assumed peak position and each assumed valley position. In this area, an identifier obtained by a paper type setting process described later is stored.

[Paper type setting process]
With reference to FIGS. 7 and 8, the paper type setting process by the multifunction machine 10 will be described. This image recording process is executed by the CPU 131 of the control unit 130. The following processes may be executed by the CPU 131 reading out and executing a program stored in the ROM 132, or may be realized by a hardware circuit mounted on the control unit 130. The paper setting process shown in FIG. 7 is started in response to a setting instruction input by the user.

  First, the control unit 130 acquires size information indicating the size of the paper 12 supported on the feeding tray 20 (S11). A specific method for acquiring the size information is not particularly limited. For example, the size information may be input by a user together with a setting instruction. Alternatively, a sensor that detects the position of the side guide that positions the end of the sheet 12 in the left-right direction 9 may be provided in the feeding tray 20. And the control part 130 may acquire the signal output from the said sensor as size information.

  Further, the control unit 130 conveys the paper 12 supported by the feeding tray 20 to the position facing the media sensor 122 to the feeding unit 15 and the conveyance roller unit 54, and emits light from the light emitting unit of the media sensor 122. The carriage 23 may be moved in the left-right direction 9 in the irradiated state. Then, the control unit 130 is in a state where the detection signal output from the media sensor 122 has changed from a state in which the detection threshold value indicating the boundary between the paper 12 and the platen 42 has been exceeded to a state in which the detection signal has been reduced, and in a state in which the detection signal has been reduced The carriage sensor value E at the position where the position has been changed from the position to the position above the position of the sheet 12 may be acquired as the edge position of the sheet 12. This process is an example of an end position acquisition process.

  Next, the control unit 130 records, for example, the pattern image 90 shown in FIG. 8 on the paper 12 (S12). Specifically, the control unit 130 causes the feeding unit 15 and the conveyance roller unit 54 to convey the paper 12 supported by the feeding tray 20 to a position facing the recording head 39. Then, the control unit 130 causes the recording head 39 to eject ink at a predetermined timing in the process of moving the carriage 23 in the left-right direction 9. Step S12 is an example of a pattern recording process. The paper 12 on which the pattern image 90 is recorded is an example of a first paper. With reference to FIG. 8, the pattern image 90 of this embodiment is demonstrated in detail.

  The pattern image 90 shown in FIG. 8 includes a plurality of summit sections including each assumed peak position (P2, P4,..., P16) and each assumed valley position (P1, P3,..., P17). It is recorded at a position on the paper 12 corresponding to each of a plurality of valley bottom sections. A plurality of pattern images 90 (six in the example of FIG. 8) arranged in the transport direction 16 are recorded in each mountain peak section and each valley bottom section. Further, identifiers (numbers “1” to “6” in the example of FIG. 8) for identifying each of the six pattern images 90 arranged in the transport direction 16 are recorded on the paper 12 next to each pattern image 90. Has been.

  The pattern image 90 is composed of three rectangular images 91, 92 and 93. The rectangular images 91 and 92 are images recorded on the recording head 39 (hereinafter referred to as “forward scanning”) in the process of moving the carriage 23 in the FWD direction. The rectangular images 91 and 92 are recorded separately in the left-right direction 9. The separation distance between the rectangular images 91 and 92 coincides with the length of the rectangular image 93 in the left-right direction 9. On the other hand, the rectangular image 93 is an image recorded on the recording head 39 (hereinafter referred to as “reverse scanning”) in the process of moving the carriage 23 in the RVS direction. A method for recording the rectangular images 91 to 93 using the pattern image 90 recorded in the valley section including the assumed valley bottom position P3 will be described in detail.

  First, the control unit 130 records six sets of rectangular images 91 and 92 arranged in the transport direction 16 at the same ejection timing by the forward scanning of the carriage 23. That is, the six sets of rectangular images 91 and 92 are recorded so that the distances in the left-right direction 9 are equal. Six sets of rectangular images 91 and 92 are recorded at each position Pn (n = 1, 2,... 17). That is, a total of 6 × 17 rectangular images 91 and 92 are recorded. Next, the control unit 130 records six rectangular images 93 between the six sets of rectangular images 91 and 92 by backward scanning of the carriage 23. The rectangular image 93 is located between the rectangular images 91 and 92 to which at least a part thereof corresponds. The six rectangular images 93 are recorded at each position Pn (n = 1, 2,... 17). That is, a total of 6 × 17 rectangular images 93 are recorded.

  Each of the six rectangular images 93 is different in the overlapping state with the set of rectangular images 91 and 92. That is, the ink ejection timings when recording each of the six rectangular images 93 are different from each other. In this embodiment, the rectangular image 93 positioned upstream in the transport direction 16 is recorded with a shift to the left. Specifically, with respect to the discharge timing of the first rectangular image 93 (that is, identified by an identifier “1” described later), the left gradually becomes the second, third,... Is recorded with a gap. That is, the ink discharge timing for recording the rectangular image 93 of the pattern image 90 identified by the identifier “1” is the latest, and the larger the identifier (that is, the rectangular image 93 positioned on the upstream side in the transport direction 16). ) The discharge timing is gradually getting faster. The rectangular images 91 and 92 are examples of the first image, and the rectangular image 93 is an example of the second image.

  As a result, the six rectangular images 93 arranged in the transport direction 16 are recorded at positions shifted from each other in the left-right direction 9. In other words, the six pattern images 90 arranged in the transport direction 16 are different from each other in the overlapping manner of the rectangular images 91 to 93. Specifically, among the six pattern images 90 recorded in the valley section including the assumed valley bottom position P3, the pattern image 90 identified by the identifier “5” is the right end of the rectangular image 91 and the left end of the rectangular image 93. And the left end of the rectangular image 92 and the right end of the rectangular image 93 overlap. On the other hand, in each pattern image 90 identified by the identifiers “1” to “4” and “6”, one of the rectangular images 91 and 92 and the rectangular image 93 overlap, and the other of the rectangular images 91 and 92 and the rectangular image 93 are overlapped. Are separated from each other.

  That is, the pattern image 90 identified by the identifier “5” is an image in which the left and right contour lines of the rectangular images 91 to 93 overlap each other at the separation distance between the sheet 12 and the recording head 39 in the valley section including the assumed valley bottom position P3. It can be expressed as Hereinafter, the pattern image 90 in which the left and right contour lines of the rectangular images 91 to 93 overlap each other is referred to as a “superimposition pattern image”, and an identifier for identifying the superposition pattern image is referred to as a “superimposition pattern identifier”.

  Similarly, the superimposition pattern identifier at the position corresponding to the assumed valley bottom position P1 is “6”, the superposition pattern identifier at the position corresponding to the assumed peak position P2 is “2”, and the position corresponding to the assumed peak position P16 is The superposition pattern identifier is “1”, and the superposition pattern identifier at the position corresponding to the assumed valley bottom position P17 is “6”. That is, the six pattern images 90 arranged in the transport direction 16 have different distances between the recording head 39 and the paper 12 when the left and right contour lines of the rectangular images 91 to 93 overlap each other. In the pattern image 90 according to the present embodiment, the smaller the identifier number, the more the left and right contour lines of the rectangular images 91 to 93 overlap each other when the distance between the recording head 39 and the paper 12 is shorter, and the larger the identifier number. When the distance between the recording head 39 and the paper 12 is long, the left and right contour lines of the rectangular images 91 to 93 overlap each other.

  Next, the control unit 130 acquires information indicating the first distance between the recording head 39 and the sheet 12 at the assumed peak position and the distance between the recording head 39 and the sheet 12 at the assumed valley position (S13). ). Specifically, the control unit 130 acquires the identifier of the superimposed pattern image at each assumed peak position and each assumed valley position (hereinafter, referred to as “superimposed pattern identifier”) from the user through the operation unit 17 and acquires it. The recorded identifier is stored in the EEPROM 134. Next, the control unit 130 acquires an average value, a maximum value, a minimum value, a median value, or the like of a plurality of superimposed pattern identifiers corresponding to each assumed peak position as information indicating the first distance. In addition, the control unit 130 acquires an average value, a maximum value, a minimum value, a median value, or the like of the superposition pattern identifier corresponding to each assumed valley position as information indicating the second distance. Step S13 is an example of an acquisition process.

  Next, in response to the difference between the first distance and the second distance being equal to or greater than the threshold (S14: Yes), the control unit 130 associates the paper type “vertical eye” with the size information acquired in step S11. Is stored in the EEPROM 134 (S15), and the paper type setting process is terminated. On the other hand, in response to the difference between the first distance and the second distance being less than the threshold (S14: No), the control unit 130 associates the paper type “landscape” with the size information acquired in step S11, and the EEPROM 134. (S16), and the paper type setting process is terminated.

[Image recording processing]
With reference to FIGS. 9 to 11, image recording processing by the multifunction machine 10 will be described. This image recording process is executed by the CPU 131 of the control unit 130. The following processes may be executed by the CPU 131 reading out and executing a program stored in the ROM 132, or may be realized by a hardware circuit mounted on the control unit 130. The image recording process shown in FIG. 9 is started in response to a recording instruction input to the multifunction device 10. The process for accepting the recording instruction is an example of the accepting process.

  The recording instruction is an instruction for causing the multi-function peripheral 10 to execute the process of recording the image indicated by the image data on the paper 12. The acquisition destination of the recording instruction is not particularly limited. For example, the recording instruction may be acquired through the operation unit 17 provided in the multifunction machine 10 or may be acquired from an external device through a communication network. The recording instruction includes, for example, image data and size information indicating the size of the paper 12 on which the image indicated by the image data is to be recorded.

  First, the control unit 130 acquires a paper type corresponding to the size of the paper 12 on which the image indicated by the image data is recorded from the EEPROM 134 (S21). The size of the paper 12 is specified by size information included in the recording instruction, for example. The sheet 12 on which the image indicated by the image data is recorded is an example of a second sheet.

  Next, the control unit 130 performs cueing processing (S22). In the cueing process, the paper 12 supported on the feeding tray 20 is fed to the feeding roller 25, the conveying roller unit 54, and the discharge until the area where the image is recorded first reaches the position facing the recording head 39. This is a process of transporting to the roller unit 55. Specifically, the control unit 130 drives the conveyance motor 102 in the reverse direction until the leading end of the paper 12 (refers to “the end on the downstream side in the conveyance direction 16”) reaches the conveyance roller unit 54. The feeding roller 25 is rotated forward. Next, the control unit 130 rotates the conveyance motor 102 in the normal direction to rotate the conveyance roller 60 and the discharge roller 62 in the normal direction until the area where the image is recorded first reaches the position facing the recording head 39. Let The leading end position of the paper 12 is specified by a combination of a change in signal from the registration sensor 120 and a pulse signal from the rotary encoder 121.

  Next, in response to the paper type acquired in step S21 being “longitudinal” (S23: Yes), the control unit 130 executes the first ejection process (S24). On the other hand, the control unit 130 executes the second ejection process in response to the paper type being “horizontal” (S23: No) (S25). The first discharge process is an example of a discharge process executed under the first condition. The second discharge process is an example of a discharge process executed under a second condition different from the first condition. The discharge process will be described in detail with reference to FIG.

  First, the control unit 130 uses the first discharge timing correction value X (m) according to the first discharge process (S41: Yes), and discharges ink (hereinafter, referred to as ink discharge timing) And the discharge timing of the ink landed on each valley bottom position (hereinafter referred to as “valley bottom discharge timing”) is calculated (S42, S43). On the other hand, the control unit 130 calculates the peak discharge timing and the valley discharge timing by using the second discharge timing correction value Y (m) according to the second discharge process (S41: No) (S44, S45). The reason for changing the discharge timing for each discharge process will be described later.

  Specifically, in step S42, the control unit 130 subtracts the first discharge timing correction value X (m) corresponding to each peak position from the reference value D0, thereby setting the discharge timing D1 (m) at each peak position. calculate. On the other hand, in step S44, the control unit 130 calculates the discharge timing D1 (m) at each peak position by subtracting the second discharge timing correction value Y (m) corresponding to each peak position from the reference value D0. Note that the first discharge timing correction value X (m) in the present embodiment is larger than the corresponding second discharge timing correction value Y (m) (that is, the value of m is the same). That is, the discharge timing at each peak position in the first discharge process is later than the discharge timing at each peak position in the second discharge process. In steps S42 and S44, m = 2, 4,.

  In step S43, the controller 130 calculates the discharge timing D1 (m) at each valley position by adding the first discharge timing correction value X (m) corresponding to each valley position to the reference value D0. On the other hand, in step S45, the controller 130 calculates the discharge timing D1 (m) at each valley position by adding the second discharge timing correction value Y (m) corresponding to each valley position to the reference value D0. That is, the discharge timing at each valley bottom position in the first discharge process is earlier than the discharge timing at each valley bottom position in the second discharge process. In steps S43 and S45, m = 1, 3,.

  Next, the control unit 130 further adjusts the peak discharge timing and the valley discharge timing according to the rear end position of the sheet 12 (refers to the “upstream end of the conveyance direction 16”) (S46) (S47). To S52). The rear end position of the sheet 12 is specified by a combination of a change in signal from the registration sensor 120 and a pulse signal from the rotary encoder 121. Moreover, the process of step S46-S52 is performed in common with a 1st discharge process and a 2nd discharge process. Furthermore, discharge timing adjustment values α and β, which will be described later, are both numerical values of 0 or more representing time, and are stored in the EEPROM 134. The reason why the ejection timing is varied in accordance with the rear end position of the sheet 12 will be described later.

  First, the control unit 130 determines that the rear end position of the sheet 12 is upstream in the conveying direction 16 from the nipping position A (see FIG. 2) of the conveying roller unit 54 (that is, the sheet 12 is moved to the conveying roller 60 and the pinch roller 61. (S46: rear end position ≦ A, hereinafter referred to as “case 1”), the peak discharge timing and the valley discharge timing are not adjusted (S47, S48). Further, the control unit 130 responds that the rear end position of the sheet 12 is downstream in the transport direction 16 from the sandwiching position A and upstream in the transport direction 16 from the waveform forming position B (S46: A <rear) End position ≦ B, hereinafter referred to as “Case 2”), the peak discharge timing and the valley discharge timing are adjusted using the discharge timing adjustment value α (S49, S50). Further, the control unit 130 responds to the fact that the rear end position of the sheet 12 is downstream in the transport direction 16 from the waveform forming position B (S46: B <rear end position, hereinafter referred to as “Case 3”). The peak discharge timing and valley discharge timing are adjusted using the discharge timing adjustment value β (S51, S52). Α and β are both values representing time, α is a positive value, and β is a negative value.

  Specifically, in step S49, the control unit 130 calculates the adjusted peak discharge timing D (m) by subtracting the discharge timing adjustment value α from each peak discharge timing D1 (m). In step S50, the controller 130 calculates the adjusted valley bottom discharge timing D (m) by adding the discharge timing adjustment value α to each valley bottom discharge timing D1 (m). That is, the adjusted peak discharge timing D (m) (= D1 (m) −α) is later than the peak discharge timing D1 (m) before adjustment. On the other hand, the adjusted valley bottom discharge timing D (m) (= D1 (m) + α) is earlier than the valley bottom discharge timing D1 (m) before adjustment. That is, the peak discharge timing of the case 2 onto the paper 12 is later than the peak discharge timing of the case 1 onto the paper 12. On the other hand, the bottom discharge timing of the case 2 onto the paper 12 is earlier than the bottom discharge timing of the case 1 onto the paper 12.

  On the other hand, in step S51, the controller 130 calculates the adjusted peak discharge timing D (m) by subtracting the discharge timing adjustment value β from each peak discharge timing D1 (m). In step S52, the controller 130 calculates the adjusted valley bottom discharge timing D (m) by adding the discharge timing adjustment value β to each valley bottom discharge timing D1 (m). That is, the adjusted peak discharge timing D (m) (= D1 (m) −β, β is a negative number) is earlier than the peak discharge timing D1 (m) before adjustment. On the other hand, the adjusted valley bottom discharge timing D (m) (= D1 (m) + β) is later than the valley bottom discharge timing D1 (m) before adjustment. That is, the peak discharge timing of the case 3 onto the paper 12 is earlier than the peak discharge timing of the case 1 onto the paper 12. On the other hand, the bottom discharge timing of the case 3 onto the paper 12 is later than the bottom discharge timing of the case 1 onto the paper 12.

  The following is derived from the relationship between the case 2 and the case 1 and the relationship between the case 3 and the case 1. That is, the peak discharge timing after the rear end position of the sheet 12 passes the waveform forming position B (that is, in the case of the case 3) is the time before the rear end position of the sheet 12 passes the waveform forming position B (that is, the case). 1 and Case 2). On the other hand, the valley discharge timing after the rear end position of the sheet 12 passes the waveform forming position B (that is, in the case of the case 3) is the time before the rear end position of the sheet 12 passes the waveform forming position B (that is, the case). 1 and case 2). In steps S49 and S51, m = 2, 4,. In steps S50 and S52, m = 1, 3,...

  Next, the control unit 130 calculates an ink ejection timing D to be landed at a midway position between the peak position 12A and the valley position 12B (S53). Specifically, the control unit 130 determines in advance the discharge timing D of the peak position 12A and the valley position 12B adjacent to the midway position, and information indicating the distance from the peak position 12A and the valley position 12B to the midway position. By substituting into the obtained interpolation function, the ejection timing D at each halfway position is calculated. Although the specific example of an interpolation function is not specifically limited, For example, a cubic function can be used.

  Then, in the process of moving the carriage 23 in the left-right direction 9, the control unit 130 causes the recording head 39 to eject ink to land at each peak position, each valley bottom position, and each midway position at the discharge timing D (S 54). Then, the discharge process ends. As a result, an image is recorded in the area of the paper 12 facing the recording head 39. The process of steps S41 to S52 is an example of a correction process.

  Returning to FIG. 9, in response to the fact that the image recording on the paper 12 has not been completed yet (S26: No), the control unit 130 executes the carrying process (S28, S29). Specifically, the control unit 130 executes the first conveyance process in response to the sheet type acquired in step S21 being “longitudinal” (S27: Yes) (S28). On the other hand, the control unit 130 executes the second transport process (S29) in response to the paper type being “horizontal” (S27: No). The carrying process is a process of carrying the paper 12 in the carrying direction 16 by a predetermined line feed width (hereinafter referred to as “carrying amount”). The first transport process is an example of a transport process executed under the first condition. The second transport process is an example of a transport process executed under the second condition. The first transport process and the second transport process differ in the transport amount per time. The conveyance process will be described in detail with reference to FIG.

  First, the control unit 130 uses the reference transport amount L0 as the transport amount L1 according to the first transport process (S61: Yes) (S62). On the other hand, the control unit 130 calculates the transport amount L1 by adding the transport amount correction value γ to the reference transport amount L0 in response to the second transport process (S61: No) (S63). The reference carry amount L0 and the carry amount correction value γ are both numerical values of 0 or more indicating the distance, and are stored in the EEPROM 134. That is, the transport amount in the second transport process is larger than the transport amount in the first transport amount. In addition, the reason why the transport amount is varied for each transport process will be described later.

  Next, the control unit 130 further adjusts the carry amount L1 according to the rear end position of the sheet 12 (S64) (S65, S66). Note that the processes in steps S65 to S66 are executed in common with the first transport process and the second transport process. First, the control unit 130 does not adjust the transport amount L1 in response to the rear end position of the paper 12 being upstream of the transport direction 16 from the waveform forming position B (S64: rear end position ≦ B) (S65). . On the other hand, in response to the rear end position of the sheet 12 being downstream in the transport direction 16 from the waveform forming position B (S64: B <rear end position), the control unit 130 adjusts the transport amount L1 to the transport amount adjustment value θ. Is added to calculate the adjusted transport amount L (S66).

  The carry amount adjustment value θ is a numerical value of 0 or more indicating the distance, and is stored in the EEPROM 134. That is, the conveyance amount after the rear end position of the paper 12 passes the waveform forming position B is larger than that before the rear end position of the paper 12 passes the waveform forming position B. In addition, the reason why the transport amount varies according to the rear end position of the paper 12 will be described later. Then, the control unit 130 drives the transport motor 102 to rotate forward, thereby causing the transport roller unit 54 and the discharge roller unit 55 to rotate forward until the sheet 12 is transported by the transport amount L in the transport direction 16 (S67). Then, the conveyance process is terminated.

  Returning to FIG. 9, the control unit 130 repeatedly executes the processing of steps S <b> 23 to S <b> 29 until image recording on the paper 12 is completed (S <b> 26: No). Steps S23 to S29 that are repeatedly executed are an example of a recording process. Then, in response to the end of image recording on the sheet 12 (S26: Yes), the control unit 130 executes a discharge process for discharging the sheet 12 on which image recording has ended to the discharge tray 21 (S30). Specifically, the control unit 130 drives the conveyance motor 102 to rotate forward until the rear end of the sheet 12 passes through the discharge roller unit 55. The control unit 130 repeatedly executes steps S22 to S30 until all images included in the recording instruction are recorded (S31: Yes). And the control part 130 complete | finishes an image recording process according to having recorded all the images included in a recording instruction (S31: No).

[Operational effects of this embodiment]
According to the present embodiment, the first condition suitable for the vertically conveyed paper 12 and the horizontally conveyed paper are compared by comparing the difference between the first distance and the second distance specified from the pattern image 90 and the threshold value. The recording process can be executed by switching the second condition suitable for Twelve. As a result, it is possible to suppress a decrease in image recording quality due to the direction of the fibers constituting the paper 12. The paper type “longitudinal” indicates that the paper 12 has been transported in the vertical direction. On the other hand, the paper type “horizontal” indicates that the paper 12 is conveyed in the horizontal direction.

  Further, by storing the paper type in the EEPROM 134, it is possible to prevent the paper type setting process from being executed every time the image recording process is performed. The paper type setting process may be executed before shipment at the assembly factory of the multifunction machine 10 or may be executed by the user before the start of use. Further, the paper type setting process may be re-executed by the user when using different types of paper.

  Note that the wave shape at the end position of the paper 12 in the left-right direction 9 tends to be unstable as compared with the central portion of the paper 12. Therefore, the control unit 130 does not have to record the pattern image 90 at the position corresponding to the assumed peak position or the assumed valley position adjacent to the end position of the paper 12 in step S12 of FIG. Accordingly, the first distance and the second distance are calculated based on the pattern image 90 recorded at the position corresponding to the assumed peak position and the assumed valley position that are not adjacent to the end position of the paper 12. As a result, it is possible to suppress a decrease in the identification accuracy of the first distance and the second distance. Note that the end position of the sheet 12 can be specified based on the sheet size acquired in step S11, for example.

  Further, the wave shape of the paper 12 in the left-right direction 9 may not be uniform. Therefore, as in the present embodiment, the first distance is specified from the average value, maximum value, minimum value, or median value of a plurality of superimposed pattern identifiers corresponding to each assumed peak position, and corresponds to each assumed valley position. The second distance is specified from the average value, maximum value, minimum value, or median value of the superimposition pattern identifier. Thereby, it is possible to suppress a decrease in the accuracy of specifying the first distance and the second distance due to the variation in the wave shape of the paper 12 in the left-right direction 9.

  Further, the waveform of the paper 12 is more stable as the position is closer to the waveform forming position B. Therefore, the control unit 130 may record the pattern image 90 on the nozzle 40 in the upstream portion in the transport direction 16 in step S12. More specifically, the control unit 130 applies the pattern image 90 to the nozzles 40 arranged in the upstream portion of the transport direction 16 from the center of the recording head 39 among the plurality of nozzles 40 arranged in the transport direction 16. It is desirable to record. Thereby, the fall of the specific precision of a 1st distance and a 2nd distance can be suppressed.

  Further, the wave shape of the paper 12 sandwiched between both the transport roller portion 54 and the discharge roller portion 55 is more stable than the wave shape of the paper 12 sandwiched between only the discharge roller portion 55. Therefore, it is desirable that the control unit 130 records the pattern image 90 on the sheet 12 sandwiched between both the transport roller unit 54 and the discharge roller unit 55 in step S12. Thereby, the fall of the specific precision of a 1st distance and a 2nd distance can be suppressed.

  In the present embodiment, an example of the method for recording the pattern image 90 has been described. However, the present invention is not limited to this. For example, the ejection timing of the ink for recording the rectangular images 91 and 92 may be varied, and the ejection timing of the ink for recording the rectangular image 93 may be constant. Furthermore, the ejection timing of ink for recording the rectangular images 91 to 93 may be varied. In other words, the plurality of pattern images 90 arranged in the transport direction 16 are specific as long as the distance between the recording head 39 and the paper 12 when the left and right contour lines of the rectangular images 91 to 93 overlap each other is different. The recording method is not limited.

  In this embodiment, the example in which the user finds the superimposed pattern identifier from the paper 12 on which the pattern image 90 is recorded has been described. However, the present invention is not limited to this. For example, the control unit 130 may record the pattern image 110 as shown in FIG. Then, the control unit 130 may cause the scanner unit to read the paper 12 on which the pattern image 110 is recorded, and acquire information indicating the first distance and the second distance from the image data generated by the scanner unit. With reference to FIG. 12, the pattern image 110 which concerns on a modification is demonstrated in detail.

  The pattern image 110 shown in FIG. 12 includes a plurality of summit sections including each assumed peak position (P2, P4,..., P16) and each assumed valley position (P1, P3,..., P17). It is recorded at a position on the paper 12 corresponding to each of a plurality of valley bottom sections. The pattern image 110 includes a long line 111 extending in the transport direction 16 and a plurality of short lines 112 </ b> A to 112 </ b> F shorter than the long line 111. A long line 111 is an image recorded by the forward scanning of the carriage 23. The short lines 112 </ b> A to 112 </ b> F are images recorded by backward scanning of the carriage 23. The long line 111 is an example of the first image, and the short lines 112A to 112F are examples of the second image. Note that the pattern image 110 recording method and the pattern image 90 recording method differ only in the images constituting each pattern image. For example, the long lines 111 may be recorded instead of the six sets of rectangular images 91 and 92, and the short lines 112 </ b> A to 112 </ b> F may be recorded instead of the six rectangular images 93. Also from the pattern image 110 shown in FIG. 12, as with the pattern image 90, it is possible to acquire information indicating the distance between the recording head 39 and the paper 12.

  Next, the control unit 130 acquires the image data by causing the scanner unit to read the paper 12 on which the pattern image 110 is recorded. And the control part 130 divides | segments the pattern image 110 into several area | region 113A-113F adjacent to the conveyance direction 16, like the pattern image 110 recorded on the valley bottom area containing the assumption valley bottom position P3. Each of the regions 113A to 113F includes one of the short lines 112A to 112F. Then, the control unit 130 integrates the luminance values of the pixels included in each of the regions 113A to 113F, and determines the region having the highest integrated luminance value as a position where the long line 111 and one of the short lines 112A to 112F overlap. .

  In the example of FIG. 12, the long line 111 and the short line 112E overlap at a position corresponding to the assumed valley bottom position P1, the long line 111 and the short line 112A overlap at a position corresponding to the assumed mountain peak position P2, and the position corresponding to the assumed valley bottom position P3. In FIG. 5, it is determined that the long line 111 and the short line 112F overlap, the long line 111 and the short line 112B overlap at a position corresponding to the assumed peak position P16, and the long line 111 and the short line 112F overlap at a position corresponding to the assumed valley position P17. The

  The control unit 130 acquires the positions of the short lines 112A to 112F overlapping the long line 111 as information indicating the first distance in the pattern image 110 recorded at the position corresponding to each assumed peak position. Moreover, the control part 130 acquires the position of short line 112A-112F which overlaps with the long line 111 among the pattern images 110 recorded on the position corresponding to each assumption valley bottom position as information which shows 2nd distance. The distance between the recording head 39 and the paper 12 is farther as the short lines 112A to 112F located on the upstream side in the conveying direction 16 overlap the long line 111, and the short lines 112A to 112F located on the downstream side in the conveying direction 16 become the long line 111. The closer you are, the closer you are.

  The control unit 130 then positions the short lines 112A to 112F overlapping the long line 111 in the pattern image 110 corresponding to the assumed peak position, and positions of the short lines 112A to 112F overlapping the long line 111 in the pattern image 110 corresponding to the assumed valley bottom position. The sheet type may be set to “longitudinal” when the distance in the transport direction 16 is equal to or greater than the threshold, and the sheet type may be set to “horizontal” when the distance is less than the threshold.

  In addition, the amplitude of the waveform of the sheet 12 conveyed in the vertical direction tends to be larger than the amplitude of the waveform of the sheet 12 conveyed in the horizontal direction. In other words, as compared with the sheet 12 transported in the horizontal direction, the sheet 12 transported in the vertical direction has the peak positions closer to the recording head 39 in the vertical direction 7 and the valley bottom positions further away from the recording head 39. Therefore, it is necessary to eject ink to land on each peak position of the paper 12 transported in the vertical direction at a later timing and eject ink to land on each valley position at an earlier timing than the paper 12 transported in the horizontal direction. There is. Therefore, as in the discharge processing of the present embodiment, the correction amount of the discharge timing for the sheet 12 conveyed in the vertical direction (that is, the first discharge timing correction value X) is the correction amount of the discharge timing for the sheet 12 conveyed in the horizontal direction. It is desirable to make it larger than (that is, the second ejection timing correction value Y). In addition, in FIG. 6, although the example which provided the 1st discharge timing correction value X and the 2nd discharge timing correction value Y for every assumption peak position and assumption valley position was demonstrated, it does not restrict to this but all assumption peak positions And it may be a value common to the assumed valley bottom position.

  Further, when the rear end position of the paper 12 is upstream of the conveyance direction 16 from the clamping position A (case 1), and when the rear end position of the paper 12 is between the clamping position A and the waveform forming position B ( It is necessary to make the ink ejection timing different between the case 2) and the case where the rear end position of the paper 12 is on the downstream side of the conveyance direction 16 from the waveform forming position B (case 3). In addition to the wave forming mechanism (specifically, at least the support rib 52 and the contact rib 85 are provided), the paper 12 of the case 1 is subjected to a holding force by the transport roller unit 54. Further, the wave forming mechanism is applied to the paper 12 of the case 2. Therefore, since the paper 12 of the case 2 is released from the correction force of the paper 12 by the conveyance roller unit 54 being sandwiched, the amplitude of the paper 12 tends to be larger than that of the case 1. Further, a force from the support rib 52 of the wave forming mechanism is applied to the paper 12 of the case 3. Therefore, since the paper 12 of the case 3 is released from the force by the contact rib 85 of the waveform forming mechanism, the amplitude of the paper 12 tends to be smaller than that of the case 1 and the case 2.

  Further, the amplitude of the sheet 12 (that is, the case 3) after passing through the waveform forming position B is smaller than the amplitude of the sheet 12 (that is, the above cases 1 and 2) before passing through the waveform forming position B. Tend. Therefore, as compared with the paper 12 before passing through the waveform forming position B, the ink for landing on each peak position of the paper 12 after passing through the waveform forming position B is ejected at an early timing and landed at each valley bottom position. It is necessary to eject the ink to be discharged at a late timing. Therefore, as in the above configuration, it is desirable that the correction amount of the discharge timing before passing through the waveform forming position B is larger than the correction amount of the discharge timing after passing through the waveform forming position B. The discharge timing adjustment values α and β may be values set individually for each assumed peak position and each assumed valley position, such as the first discharge timing correction value X and the second discharge timing correction value Y. .

  Further, the sheet 12 conveyed in the horizontal direction tends to have a larger elongation amount in the conveying direction 16 due to the absorption of the ink than the sheet 12 conveyed in the vertical direction. Therefore, in the transport process in the present embodiment, the transport amount of the paper 12 transported in the horizontal direction (that is, the transport amount in the second transport process) is changed to the transport amount of the paper that has been transported in the vertical direction (that is, transport in the first transport process). It is desirable to make it larger than (amount).

  Further, the sheet 12 after passing through the waveform forming position B tends to have a larger amount of elongation in the transport direction 16 due to the ink absorption than before passing through the waveform forming position B. Therefore, it is desirable that the transport amount after passing through the waveform forming position B is larger than the transport amount before passing through the waveform forming position B as in the transport processing of the present embodiment.

DESCRIPTION OF SYMBOLS 10 ... Multifunction machine 15 ... Feeding part 23 ... Carriage 39 ... Recording head 54 ... Conveying roller part 55 ... Discharge roller part 122 ... Media sensor 130 ... Control part 134 ・ ・ ・ EEPROM

Claims (11)

A transport unit for transporting paper in the transport direction;
A carriage mounted with a recording head for ejecting ink on the paper conveyed by the conveyance unit, and reciprocating in the main scanning direction intersecting the conveyance direction;
A carriage sensor that outputs a detection signal corresponding to the position of the carriage in the main scanning direction;
The shape of the sheet facing the recording head is formed into a wave shape in which a peak position protruding toward the recording head and a valley position protruding away from the recording head are alternately arranged in the main scanning direction. A waveform forming mechanism,
Information indicating the detection signals at a plurality of assumed peak positions where the carriage is assumed to face the peak position of the paper, and the detection at a plurality of assumed valley positions where the carriage is assumed to face the valley position of the paper. A storage unit storing information indicating a signal;
A control unit, and
The control unit
A pattern image in which the distance in the main scanning direction between the first image recorded in the forward scanning of the carriage and the second image recorded in the backward scanning of the carriage differs in the transport direction is the assumed peak position Pattern recording processing for recording on the first sheet in the summit section including the above and the valley section including the assumed valley position,
Information specified by a position on the first sheet where the first image and the second image overlap, a first distance between the recording head and the first sheet at the assumed peak position, and An acquisition process for acquiring information indicating a second distance between the recording head and the first sheet at the assumed valley bottom position;
A reception process for receiving a recording instruction including image data;
By alternately repeating discharge processing for discharging ink to the recording head in the process of moving the carriage in the main scanning direction and transport processing for transporting the second sheet to the transport unit by a predetermined line feed width, Recording processing for recording the image indicated by the data on the second sheet,
In the above recording process,
In response to the difference between the first distance and the second distance being greater than or equal to a threshold value, the recording head is operated so that ink is ejected at the first ejection timing, and the second sheet is ejected with the first transport amount. Operate the transport unit to transport,
In response to the difference between the first distance and the second distance being less than a threshold value, the discharge timing at the peak position is earlier and the discharge timing at the valley position is slower than the first discharge timing. An ink jet recording apparatus that operates the recording head to discharge ink at an ejection timing and operates the transport unit to transport the second sheet by a second transport amount that is larger than the first transport amount . The control unit
In the pattern recording process, the distance between the recording head and the paper is different when the first image and the second image overlap at positions on the first paper corresponding to the peak section and the valley section, respectively. A plurality of the pattern images are recorded side by side in the transport direction together with an identifier for identifying the pattern image,
In the above acquisition process,
The user selects the identifier for identifying the pattern image in which the first image and the second image are closest to each other among the plurality of pattern images recorded at positions corresponding to the mountain peak section and the valley bottom section, respectively. Let
The inkjet recording apparatus according to claim 1, wherein the identifier selected in the peak section is acquired as information indicating the first distance, and the identifier selected in the valley section is acquired as information indicating the second distance. . The inkjet recording apparatus includes a reading unit that reads an image recorded on paper,
The control unit
In the pattern recording process, the distance in the main scanning direction between the first image and the second image is gradually increased in the transport direction at the position on the first sheet corresponding to each of the peak section and the valley section. Record the different pattern images,
In the above acquisition process,
Causing the reading unit to read the pattern image recorded on the first sheet;
In the pattern image at a position corresponding to the mountain peak section, a position where the first image and the second image overlap is acquired as information indicating the first distance,
The inkjet recording apparatus according to claim 1, wherein a position where the first image and the second image overlap in the pattern image at a position corresponding to the valley section is acquired as information indicating the second distance.   In the acquisition process, the control unit integrates the luminance values of the pixels included in each of a plurality of regions obtained by dividing the pattern image in the conveyance direction, and the integrated luminance value is the highest. The inkjet recording apparatus according to claim 3, wherein the position is acquired as information indicating the first distance or the second distance. The waveform forming mechanism forms the paper into the waveform at the waveform forming position on the upstream side in the transport direction from the recording head,
The recording head has a plurality of nozzles arranged in the transport direction,
5. The inkjet recording according to claim 1, wherein, in the pattern recording process, the control unit records the pattern image on the nozzle disposed on the upstream side in the transport direction from the center of the recording head. apparatus. The transport unit is
A first conveying roller unit that is disposed upstream of a waveform forming position where the waveform forming mechanism forms the paper into the wave shape in the transport direction, and sandwiches and transports the paper;
A second transport roller unit disposed downstream of the carriage in the transport direction and configured to sandwich and transport the paper,
The said control part records the said pattern image on the said 1st paper pinched | interposed into both the said 1st conveyance roller part and the said 2nd conveyance roller part in the said pattern recording process. 2. An ink jet recording apparatus according to 1. The control unit
An edge position acquisition process for acquiring the edge position of the sheet in the main scanning direction is executed,
In the pattern recording process, the pattern image is recorded in the peak section including the estimated peak position that is not adjacent to the end position, and in the valley section including the estimated valley position that is not adjacent to the end position. The ink jet recording apparatus according to claim 1, wherein recording is performed. The waveform forming mechanism forms the paper into the waveform at the waveform forming position on the upstream side in the transport direction from the recording head,
In the transport process, the control unit determines the width of the line feed after the trailing end position, which is the upstream end of the sheet in the transport direction, passes the waveform forming position, and the trailing end position is the waveform forming position. the ink-jet recording apparatus according to any one of 7 to claim 1, greater than the line feed before passing. The storage unit includes: a summit ejection timing for causing the recording head to eject ink landed on each of the plurality of peak positions; and a valley bottom ejection timing for causing the recording head to eject ink to land on each of the plurality of valley bottom positions. Remember,
The discharge process includes a correction process for correcting the peak discharge timing and the valley discharge timing,
In the correction process, the control unit
The summit discharge timing when the difference between the first distance and the second distance is greater than or equal to a threshold is made slower than the summit discharge timing when the difference between the first distance and the second distance is less than a threshold ,
The valley discharge timing when the difference between the first distance and the second distance is greater than or equal to a threshold is made earlier than the valley discharge timing when the difference between the first distance and the second distance is less than a threshold. Item 9. The ink jet recording apparatus according to any one of Items 1 to 8 . The waveform forming mechanism forms the paper into the waveform at the waveform forming position on the upstream side in the transport direction from the recording head,
In the correction process, the control unit
The summit discharge timing before the rear end position, which is the upstream end of the sheet in the conveyance direction, passes the corrugated position, and the summit discharge timing after the rear end position passes the corrugated position. Slower,
The ink jet recording apparatus according to claim 9 , wherein the valley discharge timing before the rear end position passes the waveform forming position is set earlier than the valley discharge timing after the rear end position passes the waveform forming position. . A transport unit that transports the paper in the transport direction; a carriage that includes a recording head that ejects ink on the paper transported by the transport unit; and that reciprocates in the main scanning direction that intersects the transport direction; and the main scanning direction A carriage sensor that outputs a detection signal according to the position of the carriage, and a peak position that protrudes toward the recording head and a valley bottom that protrudes away from the recording head. A waveform forming mechanism for forming a waveform having a plurality of positions alternately arranged in the main scanning direction, and information indicating the detection signals at a plurality of assumed peak positions where the carriage is assumed to face the peak position of the paper; And the detection signals at a plurality of assumed valley positions where the carriage is assumed to face the valley position of the sheet. A storage unit that broadcast is stored, an ink jet recording method for recording an image on a sheet by the inkjet recording apparatus comprising: a control unit, a
The inkjet recording method is
A pattern image in which the distance in the main scanning direction between the first image recorded in the forward scanning of the carriage and the second image recorded in the backward scanning of the carriage differs in the transport direction is the assumed peak position A pattern recording step for recording on the first sheet in the summit section including the above and the valley section including the assumed valley position,
Information specified by a position on the first sheet where the first image and the second image overlap, a first distance between the recording head and the first sheet at the assumed peak position, and An acquisition step of acquiring information indicating a second distance between the recording head and the first sheet at the assumed valley bottom position;
A reception step for receiving a recording instruction including image data;
By alternately repeating an ejection step for ejecting ink to the recording head in the process of moving the carriage in the main scanning direction and a transport step for transporting the second sheet to the transport unit by a predetermined line feed width, Recording the image indicated by the data on the second sheet,
In the above recording step,
In response to the difference between the first distance and the second distance being greater than or equal to a threshold value, the recording head is operated so that ink is ejected at the first ejection timing, and the second sheet is ejected with the first transport amount. Operate the transport unit to transport,
In response to the difference between the first distance and the second distance being less than a threshold value, the discharge timing at the peak position is earlier and the discharge timing at the valley position is slower than the first discharge timing. An ink jet recording method in which the recording head is operated so as to eject ink at an ejection timing, and the transport unit is operated so that the second paper is transported by a second transport amount larger than the first transport amount .

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