JP2016049653A - Ink jet recording device, program, and image recording method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ink jet recording device that reduces the amount of ink impacted not on a sheet.SOLUTION: An ink jet recording device performs a detecting process (S13) of detecting a sheet end part position based upon a detection signal; a determining process (S12) of determining a width-directional length of an impact region where ink ejected to a recording part is impacted; a carrying process (S11, S15) of carrying the sheet to a carrying part; and an ejecting process (S13) of ejecting the ink to the recording part toward the impact region of the sheet carried in the carrying process, a plurality of times respectively. In up to an (n-1)th determining process, the impact region is determined to have a first width, and in (n)th and succeeding determining processes, the impact region is determined to have a second width shorter than the first width on condition that an amount of deviation in end part position detected in the first and (n)th detecting processes is less than a threshold in the (n)th and succeeding determining processes.SELECTED DRAWING: Figure 5

Description

  The present invention relates to an ink jet recording apparatus capable of so-called borderless printing.

  2. Description of the Related Art Conventionally, an ink jet recording apparatus capable of so-called borderless printing for recording an image on the entire sheet is known. For example, Patent Document 1 discloses an ink jet recording apparatus that discharges ink to an extended region that protrudes from an ideal sheet position in consideration of the possibility that the conveyed sheet is skewed.

JP 2008-188784 A

  However, according to the ink jet recording apparatus having the above configuration, when an image is recorded on a sheet having a small skew, there is a problem that the ink ejected toward the protruding area is wasted. Another problem is that the ink jet recording apparatus is contaminated by ink that has landed outside the sheet.

  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 reduces the amount of ink that lands outside a sheet in so-called borderless printing.

  An ink jet recording apparatus according to the present invention intersects with a transport unit that transports a sheet in a transport direction, a recording unit that records an image on the sheet by ejecting ink, and the transport direction of the sheet transported by the transport unit. A sensor that outputs a detection signal corresponding to the position of the end in the width direction, and a control unit that executes a recording process for recording an image on the sheet. In the recording process, the control unit is a detection process that detects the end position based on the detection signal, and an area where ink discharged to the recording unit lands, and includes an area in the sheet and an area outside the sheet. A determination process for determining the length in the width direction of the landing area including the sheet, a conveyance process for conveying the sheet to the conveyance unit, and an ink in the recording unit toward the landing area of the sheet conveyed in the conveyance process. And the discharge process for discharging each of the plurality of times, and in the determination process up to n-1 (where n> 1 is a natural number) times, the landing area is determined to be the first width, and the determination after the nth time is determined. In the process, the landing area is determined to be a second width shorter than the first width in response to the deviation amount of the end position detected in the first and n-th detection processes being less than the threshold value.

  According to the above configuration, it is possible to estimate the degree of skew of the sheet based on the amount of shift in the width direction of the end positions separated in the conveyance direction. Then, when the amount of deviation is small (that is, when skewing is small), the amount of ink that lands outside the sheet can be reduced by reducing the width of the area outside the sheet.

  The program according to the present invention includes a conveyance unit that conveys a sheet in the conveyance direction, a recording unit that records an image on the sheet by discharging ink, and a width that intersects the conveyance direction of the sheet conveyed by the conveyance unit. This can be executed by a computer connected to an ink jet recording apparatus that includes a sensor that outputs a detection signal corresponding to the position of the end of the direction and a control unit that executes a recording process for recording an image on a sheet. In the recording process for recording an image on a sheet, the program includes a detection process for detecting the end position based on the detection signal, an area on which ink ejected to the recording unit lands, A determination process for determining the length in the width direction of the landing area including the area outside the sheet, a conveyance process for conveying the sheet to the conveyance unit, and the landing area of the sheet conveyed in the conveyance process, In the determination process up to n−1 (where n> 1 is a natural number) times, the landing area is determined to be the first width. In the determination process after the nth time, the landing area is set to the first width according to the amount of deviation of the end position detected in the first detection process and the nth detection process being less than the threshold value. It is determined to be short the second width.

  The image recording method according to the present invention includes a conveyance unit that conveys a sheet in a conveyance direction, a recording unit that records an image on the sheet by discharging ink, and the conveyance direction of the sheet conveyed by the conveyance unit. This is executed by an ink jet recording apparatus that includes a sensor that outputs a detection signal corresponding to an end position in the width direction and a control unit that executes a recording process for recording an image on a sheet. The image recording method includes a detection process for detecting the end position based on the detection signal, an area where ink ejected to the recording unit is landed, and a landing area including an in-sheet area and an out-sheet area. Determination processing for determining the length in the width direction, transport processing for transporting the sheet to the transport unit, and ejection for ejecting ink to the recording unit toward the landing area of the sheet transported by the transport processing Each of the processes is executed a plurality of times, and in the determination process up to n-1 (where n> 1 is a natural number), the landing area is determined to be the first width, and in the determination process after the nth, The landing area is determined to be a second width shorter than the first width in response to the deviation amount of the end position detected in the first and n-th detection processes being less than the threshold value.

  According to the present invention, by reducing the width of the landing area when the shift amount in the width direction of the plurality of end positions detected at positions separated in the conveyance direction is small (that is, the skew is small), The amount of ink that lands outside can be reduced.

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 block diagram of the printer unit 11. FIG. 5 is a flowchart of the image recording process. FIG. 6 is a flowchart of the landing area determination process. 7A and 7B are diagrams showing a landing area 70, where FIG. 7A shows a landing area 70 of the first width, FIG. 7B shows a landing area 70 of the second width, and FIG. 7C shows a landing area of the third width. 70 is shown. FIG. 8 is an example of the images 81 to 83 before and after the image generation processing. (A) shows the image 81 before the image generation processing, (B) shows the image 82 after enlargement, and (C) shows the image after cropping. The image 83 is shown. FIG. 9 shows an example of the relationship between the paper 12 and the landing area 70, where (A) shows the case where the first deviation amount and the second deviation amount are less than the threshold value, and (B) shows the first deviation amount and the second deviation amount. The case where the amount of deviation is greater than or equal to the threshold is shown. FIG. 10 shows another example of the landing area determination process. FIG. 11 shows an example in which an image recording process is applied to a layout image. (A) shows an image 91 before image generation processing, (B) shows an image 92 after cropping, and (C) shows a first image. The landing area 70 in the case where the deviation amount and the second deviation amount are less than the threshold value is shown.

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

[Overall configuration of MFP 10]
As shown in FIG. 1, the multifunction machine 10 is formed in a substantially rectangular parallelepiped. The multifunction machine 10 includes a printer unit 11 that records an image on a sheet 12 (an example of a sheet, see FIG. 2) using an inkjet recording method at the bottom. 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. It has. 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 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 feeding roller 25 rotates in the direction in which the paper 12 is conveyed in the conveyance direction 16 (hereinafter referred to as “forward rotation”) by the reverse rotation of the conveyance motor 102 (see FIG. 4). The feeding arm 26 is rotatably supported by a shaft 27 supported by the frame of the printer unit 11.

[Conveyance path 65]
As shown in FIG. 2, the conveyance path 65 indicates a space formed by guide members 18, 19 and the like facing each other at a predetermined interval inside the printer unit 11. The conveyance path 65 is a path that makes a U-turn from the rear end portion of the feeding tray 20 to the rear side of the printer unit 11 while extending upward from below and reaches the discharge tray 21 via 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 paper 12 is sandwiched between a transport roller 60 and a pinch roller 61 that are rotated forward by the forward rotation of the transport motor 102 and is transported in the transport direction 16.

[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 sheet 12 is nipped between the discharge roller 62 and the spur 63 that are rotated forward by the normal rotation of the conveyance motor 102, and is conveyed in the conveyance direction 16.

[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 the presence of the sheet 12 at the installation position of the registration sensor 120. The registration sensor 120 outputs a low level signal, which is an example of a detection signal, to the control unit 130 (see FIG. 4), which will be described later, in response to the presence of the paper 12 at the installation position. On the other hand, the registration sensor 120 outputs a high level signal, which is an example of a detection signal, to the control unit 130 in response to the fact that the paper 12 is not present at the installation position.

[Rotary encoder 121]
Further, as shown in FIG. 4, the printer unit 11 includes a known rotary encoder 121 that generates a pulse signal according to the rotation of the conveyance roller 60 (in other words, the rotation drive of the conveyance 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 38A, and a media sensor 122 (an example of a sensor). 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 connected to a known belt mechanism provided on the guide rail 44. This belt mechanism is driven by a carriage motor 103 (see FIG. 4). That is, the carriage 23 connected to the belt mechanism that moves circumferentially by driving the carriage motor 103 can reciprocate in the main scanning direction along the left-right direction 9.

  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.

  Note that the recording unit 24 in the present embodiment repeats the ejection process for ejecting ink to the recording head 39 during the process in which the carriage 23 moves in one or the other of the left and right directions 9 at least once, typically a plurality of times. Thus, an image is recorded on the paper 12. In this specification, as shown in FIG. 9, an area where ink is ejected by one ejection process is defined as an nth landing area. That is, the landing area 70 shown in FIG. 9 is partitioned into first to fourth landing areas 70 </ b> A to 70 </ b> D adjacent to the transport direction 16. Further, in this specification, an area of the paper 12 on which an image is recorded by ink ejected to the nth landing area is defined as an nth unit area. That is, the paper 12 is divided into a plurality of unit areas adjacent to the transport direction 16.

  The guide rail 44 is provided with a belt-like encoder strip 38 </ b> B extending in the left-right direction 9. The encoder sensor 38A is mounted on the lower surface 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.

[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 and supports the paper 12 conveyed by the conveyance roller unit 54 from below. The light reflectance of the platen 42 in this embodiment is set lower than that of the paper 12.

[Media sensor 122]
As shown in FIG. 2, the media sensor 122 is mounted on the carriage 23 on the lower surface of the carriage 23 (the surface facing the platen 42). The media sensor 122 includes a light emitting unit composed of a light emitting diode or the like, and a light receiving unit composed of an optical sensor or the like. 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 signal level to the control unit 130 as the received light amount is larger.

[Communication unit 14]
As illustrated in FIG. 4, the multifunction machine 10 includes a communication unit 14. The communication unit 14 is an interface for communicating with an external device through a communication network. Although the specific example of an external device is not specifically limited, For example, they are PC (Personal Computer), a smart phone, a tablet terminal, etc. Specific examples of the communication network are not particularly limited. For example, a wired LAN (abbreviation for local area network), a wireless LAN, a WAN (abbreviation for wide area network), or a combination thereof may be used. The communication unit 14 may be an interface for connecting a cable such as a USB (Universal Serial Bus) directly connected to an external device.

[Control unit 130]
As shown in FIG. 4, the control unit 130 includes a CPU 131, a ROM 132, a RAM 133, an EEPROM 134, and an ASIC 135, which are connected by an internal bus 137. The ROM 132 stores a program for the CPU 131 to control various operations. The RAM 133 is used as a storage area for temporarily recording data and signals used when the CPU 131 executes the program, or as a work area for data processing. The EEPROM 134 stores settings, flags, and the like that should be retained even after the power is turned off.

  A transport motor 102 and a carriage motor 103 are connected to the ASIC 135. The ASIC 135 generates a drive signal for rotating each motor, and controls each motor based on the drive signal. Each motor rotates normally or reversely according to a drive signal from the ASIC 135. For example, the control unit 130 controls the driving of the 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. Furthermore, the control unit 130 acquires a recording instruction or the like from an external device through the communication unit 14.

  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 (an example of the width direction intersecting the transport direction 16) based on the detection signal output from the media sensor 122.

[Image recording processing]
An image recording process (an example of a recording process) by the multifunction machine 10 will be described with reference to FIGS. 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 control unit 130 according to the present embodiment executes the image recording process shown in FIG. 5 in response to a recording instruction being input to the multifunction machine 10.

  The recording instruction is an instruction for causing the multi-function peripheral 10 to execute an image recording process for recording the image indicated by the image data on the paper 12. The recording instruction includes, for example, image data indicating an image to be recorded on the paper 12, size information indicating the size (for example, A4, B4, etc.) of the paper 12 on which the image is recorded, and a borderless printing flag. . The borderless printing flag is information indicating that the image recording process according to the recording instruction is so-called borderless printing. The acquisition destination of the recording instruction is not particularly limited. For example, the recording instruction may be acquired from an external device through the communication unit 14 or may be acquired through an operation unit provided in the multifunction machine 10. The process of acquiring a recording process including image data is an example of an acquisition process.

  First, the control unit 130 performs a cueing process (S10). The cueing process is a process of causing the recording head 39 to face the unit area of the paper 12 on which an image is first recorded. Specifically, the control unit 130 rotates the feeding roller 25 in the forward direction by driving the transport motor 102 in the reverse direction. Next, the control unit 130 drives the conveyance motor 102 to rotate forward in response to the leading end of the paper 12 (referring to the “end on the downstream side of the conveyance direction 16”) reaching the conveyance roller unit 54. Thus, the transport roller 60 and the discharge roller 62 are rotated forward. Note that the position of the leading edge of the paper 12 is specified by a combination of a change in the signal from the registration sensor 120 and a pulse signal from the rotary encoder 121.

  Next, the control unit 130 performs detection processing (S11). The detection process is a process of detecting the end position in the left-right direction 9 of the paper 12 facing the recording head 39. Specifically, the control unit 130 irradiates light from the light emitting unit of the media sensor 122 in the process of driving the carriage motor 103 to move the carriage 23 in the left-right direction 9. Further, the control unit 130 detects a position where the change amount of the detection signal output from the media sensor 122 is equal to or greater than the threshold change amount as the end position of the paper 12. The end position may be specified by the encoder value of the carriage sensor 38, for example.

  Next, the control unit 130 executes a landing area determination process (S12). The landing area determination process is a process of determining the size (particularly the length in the left-right direction 9) of the landing area 70 on which the ink droplets ejected to the recording head 39 can land. The process of step S12 is an example of a determination process. The details of the landing area determination process (S12) will be described later. Then, according to the size of the landing area 70 determined in step S12, the control unit 130 executes the discharge process and the detection process in parallel (S13). The ejection process is a process of ejecting ink to the recording head 39 toward the paper 12 facing the recording head 39 in a cueing process (S11) or a conveyance process (S15) described later.

  Next, in response to the fact that the image recording on the paper 12 has not yet been completed (S14: No), the control unit 130 executes a conveyance process (S15). The transport process is a process of transporting the paper 12 in the transport direction 16 by a predetermined line feed width. In other words, the control unit 130 causes the unit area of the paper 12 on which an image is to be recorded next to face the recording head 39 in the conveyance process. Specifically, the control unit 130 rotates the conveyance motor 102 in the normal direction to rotate the conveyance roller unit 54 and the discharge roller unit 55 in the normal direction. Then, the control unit 130 repeatedly executes the processes of steps S12 to S15 until the image recording on the paper 12 is completed (S16: Yes).

  Then, in response to the end of image recording on the paper 12 (S14: Yes), the control unit 130 executes a discharge process for discharging the paper 12 to the discharge tray 21 (S16). Specifically, the control unit 130 rotates the conveyance motor 102 in the normal direction to rotate the conveyance roller unit 54 and the discharge roller unit 55 in the normal direction. Furthermore, the control unit 130 repeatedly executes steps S10 to S16 until all images included in the recording instruction are recorded (S17: Yes). Then, the control unit 130 ends the image recording process in response to recording all the images included in the recording instruction (S17: No).

[Attack area determination processing]
Next, the landing area determination process will be described in detail with reference to FIGS. 7 and 8, the entire image recorded on the paper 12 is illustrated and described. However, what is processed in one landing area determination process is that ink is ejected in the next ejection process (S13). This is for an image recorded in the nth landing area.

  First, in response to the number of detection processing executions being less than n times (S30: No), the control unit 130, as shown in FIG. "Length" is determined as the first width (S32). Moreover, the control part 130 is the width | variety of the landing area | region 70 according to the frequency | count of execution of a detection process (S11) being n times or more (S30: Yes) and the 1st deviation | shift amount being more than a threshold value (S31: No). Is determined to be the first width (S32). The first misalignment amount is detected, for example, in the first end position of the paper 12 detected in the detection process in step S10 and in the nth detection process (n is a natural number of 2 or more, for example, n = 2). The length in the left-right direction 9 with respect to the n-th end position of the paper 12 is indicated.

  Further, the control unit 130 lands according to the fact that the first deviation amount is less than the threshold value and the second deviation amount is equal to or more than the threshold value (S31: Yes & S33: No), as shown in FIG. The width of the region 70 is determined as the second width (S34). For example, the second misalignment amount is detected by the n-th end position of the paper 12 detected in the n-th detection process and the n + k (k is a natural number of 1 or more, for example, k = 1) detection process. The length in the left-right direction 9 with respect to the position of the (n + k) end portion of the paper 12 is indicated. Further, in the landing area determination process when the number of detection processing executions is less than (n + k) times, the control unit 130 assumes that the second deviation amount is equal to or larger than the threshold (S33: No), and sets the width of the landing area 70. The second width is determined.

  Furthermore, in response to both the first deviation amount and the second deviation amount being less than the threshold (S31: Yes & S33: Yes), the control unit 130, as shown in FIG. The width is determined to be the third width (S35). In the present embodiment, the second width is smaller than the first width, and the third width is smaller than the first width and the second width. In the present embodiment, the following processing will be described assuming that n = 2 and k = 1.

  As shown in FIG. 7, the landing area 70 includes an in-sheet area 71 and an out-sheet area 72. The in-sheet area 71 is an area corresponding to the size of the paper 12 indicated by the size information. In other words, the in-sheet area 71 is an area that coincides with the area of the sheet 12 conveyed without being skewed to the position facing the recording head 39. The sheet outer area 72 is a frame-shaped area adjacent to the outer edge of the sheet inner area 71. That is, the outside-sheet region 72 is a region adjacent to the inside-sheet region 71 on the upstream side and downstream side in the conveyance direction 16 and on both sides in the left-right direction 9.

  The first width, the second width, and the third width described above indicate the sum of the length in the left-right direction 9 of the in-sheet region 71 and the length in the left-right direction 9 of the outer region 72 adjacent to the in-sheet region 71. . As shown in FIG. 7, the length in the left-right direction 9 of the outer region 72 in the present embodiment is 3 mm when the landing region 70 has the first width, and 2 mm when the landing region 70 has the second width. When the landing area 70 has the third width, it becomes 1 mm.

  Next, the control unit 130 executes image generation processing (S36). The image generation processing uses the first image data indicating the image 81 to be recorded in the in-sheet area 71 (see FIG. 8A), and the second image data indicating the image 83 to be recorded in the landing area 70. (See FIG. 8C). The first image data includes a plurality of pixel values constituting the image 81. The second image data includes a plurality of pixel values constituting the image 82.

  First, the control unit 130 generates image data indicating the image 82 shown in FIG. 8B by enlarging the image 81 shown in FIG. 8A at a predetermined magnification. Next, the control unit 130 generates image data indicating the image 83 shown in FIG. 8C by cropping the outer edge of the image 82 shown in FIG. 8B. Here, the size of the image 81 indicated by the broken line in FIG. 8 corresponds to the size of the paper 12 indicated by the size information. Further, the size of the image 83 indicated by the alternate long and short dash line in FIG. 8 corresponds to the size of the landing area 70 determined in steps S31 to S35. That is, the size of the portion to be deleted by cropping (that is, the region surrounded by the solid line and the alternate long and short dash line in FIG. 8C) varies depending on the size of the landing region 70 determined in steps S31 to S35. .

  In the example of FIG. 9, ink is ejected toward the first landing area 70A in the first ejection process, and ink is directed toward the second landing area 70B in the second ejection process among the repeatedly executed ejection processes. In the third ejection area 70C, ink is ejected in the third ejection process, and in the fourth ejection area 70D, ink is ejected in the fourth ejection process. As a result, an image 83 (more specifically, a part of the image 83) is recorded in the unit area of the paper 12 corresponding to each of the landing areas 70A to 70D. Of the detection processes that are repeatedly executed, the first end position is detected by the first detection process, the second end position is detected by the second detection process, and the third end position is detected by the third detection process. The part position is detected.

  Here, FIG. 9A is a diagram illustrating an example of the relationship between the sheet 12 and the landing area 70 when both the first deviation amount and the second deviation amount are less than the threshold value. In this case, the first landing area 70A and the second landing area 70B are determined to have the first width in the first and second landing area determination processing, and the third landing area 70C is set to the second width in the third landing area determination processing. In the fourth landing area determination process, the fourth landing area 70D is determined to have the third width. On the other hand, FIG. 9B is a diagram illustrating an example of the relationship between the paper 12 and the landing area 70 when both the first deviation amount and the second deviation amount are equal to or greater than the threshold value. In this case, in the landing area determination process that is repeatedly executed, all of the first to fourth landing areas 70A to 70D are determined to have the first width.

[Operational effects of this embodiment]
According to the above-described embodiment, the degree of skew of the paper 12 can be estimated from the amount of deviation in the left-right direction 9 between the two end positions separated in the transport direction 16. Then, when the amount of deviation is small (that is, when the skew is small), the amount of ink that lands outside the paper 12 can be reduced by reducing the width of the landing region 70. Further, by comparing each of the first deviation amount and the second deviation amount calculated at different positions in the transport direction 16 with a threshold value, the estimation accuracy of the degree of skew of the paper 12 is improved. Then, by reducing the width of the landing area 70 in a stepwise manner in accordance with the comparison result, the paper 12 is prevented from forming an edge (referring to a portion where “ink does not land”) on the paper 12. It is possible to reduce the amount of ink that is landed outside.

  In the above embodiment, the example in which the detection process is executed in parallel with all the discharge processes that are repeatedly executed has been described. However, the execution timing of the detection process is not limited to the above example. For example, the control unit 130 may execute the detection process in response to the arrival of a predetermined detection timing (for example, the timing for executing the first, third,... Ejection process). Further, the detection process is not limited to being executed in parallel with the ejection process, and may be executed independently. Further, the first detection process (S11) may be omitted. In this case, a default value is used for the first end position.

  In the above-described embodiment, the example in which the distance in the left-right direction 9 between the two end positions adjacent to the conveyance direction 16 is used as the amount of deviation has been described, but the method of calculating the amount of deviation is not limited to this. For example, the first detection process is performed by setting the distance in the left-right direction 9 between the first end position detected in the first detection process and the nth end position detected in the n-th detection process as the first deviation amount. The distance in the left-right direction 9 between the first end position detected in step (b) and the (n + k) end position detected in the (n + k) th detection process may be used as the second shift amount. That is, the two end positions for calculating the deviation amount may be those detected by two detection processes executed before and after at least one conveyance process.

  However, when the first deviation amount and the second deviation amount having different distances in the conveyance direction 16 (hereinafter referred to as “separation distance”) of the two end positions for calculating the deviation amount are compared with the same threshold value. There is a possibility that the degree of skew of the paper 12 cannot be estimated appropriately. Therefore, in such a case, it is desirable to compare the deviation amount and the threshold value in consideration of the separation distance. For example, before comparing the deviation amount with the threshold value, the deviation amount may be divided by the corresponding separation distance, or the corresponding separation distance may be multiplied by the threshold value.

  In the above-described embodiment, an example in which the threshold value to be compared with the deviation amount is one is described. However, the number of threshold values is not limited to this, and a plurality of threshold values may be used. Another example of the landing area determination process will be described with reference to FIG. However, a detailed description of points common to the landing area determination process shown in FIG. 6 is omitted, and the differences will be mainly described.

  First, the control unit 130 determines the landing area 70 as the first width in response to the amount of deviation being equal to or greater than the first threshold (S41: No) (S42). Further, the control unit 130 determines the landing area 70 to be the second width in response to the amount of deviation being less than the first threshold and greater than or equal to the second threshold (S41: Yes & S43: No) (S44). Furthermore, the control unit 130 determines the landing area 70 to be the third width in response to the amount of deviation being less than the first threshold and less than the second threshold (S41: Yes & S43: Yes) (S45). Note that the second threshold value in the example of FIG. 10 is a value smaller than the first threshold value. As a result, the width of the landing area 70 can be appropriately determined according to the degree of skew of the paper 12. As a result, the amount of ink that lands outside the paper 12 can be further reduced.

  Furthermore, in the above embodiment, the image recording process for recording one image on the entire area of the paper 12 has been described. However, the image recording process shown in FIG. 5 is a so-called layout printing in which a plurality of images A to I arranged in the transport direction 16 and the left-right direction 9 are recorded on the paper 12 as shown in FIG. It can also be applied to. Hereinafter, detailed description of points common to the above embodiment will be omitted, and points unique to layout printing will be described in detail.

  For example, the control unit 130 acquires image data indicating the image 91 shown in FIG. 11A from the recording instruction. The size of the image 91 corresponds to the size of the paper 12 indicated by the size information (that is, the size of the in-sheet area 71). Next, in the image generation process, the control unit 130 enlarges the image 91 shown in FIG. 11A at a predetermined magnification, and further crops the image 91 to the size of the landing area 70, thereby FIG. The image data indicating the image 92 shown in FIG. At this time, the control unit 130 may interpolate the pixel value of the image in the outside-sheet region 72 adjacent to the image using the pixel value of the image in contact with the outer edge of the in-sheet region 71. Specifically, the control unit 130 may interpolate the pixel values constituting the images A1 and A2 of the outside-sheet region 72 adjacent to the image A using the pixel values of the image A.

  Next, the control unit 130 records the image 92 on the paper 12 by repeatedly executing the ejection process based on the image data generated by the above-described image generation process. Here, the images A to C (an example of the first image) are recorded on the paper 12 by a plurality of ejection processes. That is, in the ejection process for recording the images A to C on the paper 12, the detection process is executed a plurality of times. Images D to F (an example of a second image) recorded on the paper 12 on the upstream side in the transport direction 16 from the images A to C and an image G recorded on the paper 12 on the upstream side in the transport direction 16 from the images D to F. The same applies to ˜I (an example of the third image).

  Then, as illustrated in FIG. 11C, the control unit 130 determines the landing area 70 as the first width in the landing area determination process for the images A to C. Further, in the landing area determination process for the images D to F, the control unit 130 has an amount of deviation obtained from the two end positions detected by the detection process executed when the images A to C are recorded being less than the threshold value. Accordingly, the landing area 70 is determined to be the second width. Furthermore, in response to the landing area determination processing for the images G to I, the control unit 130 responds that the amount of deviation obtained from the two end positions detected by the detection processing at the time of recording the images A to F is less than the threshold value. Thus, the landing area 70 is determined to be the third width.

  Further, instead of the landing area determination process shown in FIG. 6, the landing area determination process shown in FIG. 10 may be executed during layout printing. That is, in the landing area determination process for the images D to F, the control unit 130 has an amount of deviation obtained from the two end positions detected by the detection process at the time of recording the images A to C equal to or greater than the first threshold value. The landing area 70 is determined to be the first width according to the difference, the landing area 70 is determined to be the second width according to the amount of deviation being less than the first threshold and greater than or equal to the second threshold, and the amount of deviation is the first threshold. The landing area 70 may be determined to be the third width in response to being less than the second threshold value.

  Accordingly, in so-called layout printing in which a plurality of images A to I are recorded side by side on one sheet 12, a landing area 70 having an appropriate size corresponding to the degree of skew of the sheet 12 is set for each of the images A to I. be able to. In the example of FIG. 11, the example of the image 91 in which the images A to C, D to F, and G to I are arranged in the left-right direction 9 has been described, but a plurality of images may be arranged at least in the transport direction 16. That's fine.

  In the above-described embodiment, the example in which the landing area determination process (S12) is executed by the multifunction machine 10 has been described. However, the execution subject of the landing area determination process is not limited to the multifunction machine 10. For example, the landing area determination process (S12) may be executed by an external device connected to the multifunction machine 10 via a communication line or the like. In this case, the external device receives the result of the detection process executed by the multifunction device 10 (that is, position information indicating the end position) from the multifunction device 10 through the communication line. And an external device should just perform a landing area | region determination process (S12) based on the deviation | shift amount calculated by the received positional information.

DESCRIPTION OF SYMBOLS 10 ... MFP 24 ... Recording part 54 ... Conveying roller part 55 ... Discharge roller part 70 ... Landing area 71 ... In-sheet area 72 ... Out-of-sheet area 122 ... Media sensor 130 ... control unit

Claims (9)

A transport unit that transports the sheet in the transport direction;
A recording unit that records an image on a sheet by discharging ink;
A sensor that outputs a detection signal corresponding to an end position in a width direction intersecting the conveyance direction of the sheet conveyed by the conveyance unit;
A control unit that executes a recording process for recording an image on a sheet,
In the recording process, the control unit
A detection process for detecting the end position based on the detection signal;
A determination process for determining the length in the width direction of the landing area, which is an area where the ink ejected to the recording unit is landed, and includes an in-sheet area and an out-sheet area;
A conveying process for conveying the sheet to the conveying unit;
A discharge process for discharging the ink to the recording unit is performed a plurality of times toward the landing area of the sheet conveyed in the conveyance process,
In the determination process up to n-1 (where n> 1 natural number) times, the landing area is determined to be the first width,
In the n-th and subsequent determination processes, the landing area is set to a second shorter than the first width in response to the amount of deviation of the end position detected in the first and n-th detection processes being less than a threshold value. An ink jet recording apparatus that determines the width.   In the determination process after the n + k (where k ≧ 1 natural number) times, the control unit shifts the first and nth end positions, and the first and n + k end positions or n 2. The ink jet recording apparatus according to claim 1, wherein the landing area is determined to be a third width shorter than the second width in accordance with both the shift amount of the end position and the n + k-th end position being less than the threshold value. In the determination process, the control unit
In response to the deviation amount being equal to or greater than the first threshold, the landing area is determined to be the first width,
In response to the amount of deviation being less than the first threshold, the landing area is determined to be the second width,
2. The ink jet recording apparatus according to claim 1, wherein the landing area is determined to be a third width shorter than the second width in response to the amount of deviation being less than the second threshold smaller than the first threshold. The control unit
An acquisition process for acquiring image data including a first image recorded on the sheet and a second image recorded on the sheet on the upstream side in the transport direction from the first image;
In the determination process for the first image, the landing area is determined to be the first width,
In the recording process for the first image, the detection process is executed a plurality of times,
In the determination process for the second image,
In response to the deviation amount being equal to or greater than the threshold value, the landing area is determined as the first width,
The inkjet recording apparatus according to claim 1, wherein the landing area is determined to be the second width in response to the amount of deviation being less than the threshold value. The control unit
In the acquisition process, the image data further including a third image recorded on the sheet on the upstream side in the transport direction from the second image is acquired;
In the recording process for the first image and the second image, the detection process is executed n + k (where k ≧ 1 is a natural number) times or more,
In the determination process for the third image,
The first shift amount at the first and n-th end positions is less than the above threshold, and the second shift amount at the first and n + k end positions or the second shift amount at the n-th and n + k end positions. Is determined to be the second width in response to being equal to or greater than the threshold value,
The inkjet recording apparatus according to claim 4, wherein the landing area is determined to be a third width shorter than the second width in response to both the first deviation amount and the second deviation amount being less than the threshold value. The control unit
In the determination process for the second image,
In response to the deviation amount being equal to or greater than the first threshold, the landing area is determined to be the first width,
In response to the amount of deviation being less than the first threshold, the landing area is determined to be the second width,
5. The ink jet recording apparatus according to claim 4, wherein the landing area is determined to be a third width shorter than the second width in response to the amount of deviation being less than the second threshold smaller than the first threshold. The control unit
In the acquisition process, first image data including a plurality of pixel values constituting an image to be recorded in the in-sheet area is acquired;
In the determination process, an image generation process for generating, using the first image data, second image data including a plurality of pixel values constituting an image to be recorded in the landing area,
In the image generation process,
In response to the amount of deviation being equal to or greater than the threshold value, the second image data having the first width is generated,
The inkjet recording apparatus according to claim 4, wherein the second image data having the second width is generated in response to the deviation amount being less than the threshold value. According to a conveyance unit that conveys the sheet in the conveyance direction, a recording unit that records an image on the sheet by discharging ink, and an end position in the width direction that intersects the conveyance direction of the sheet conveyed by the conveyance unit A program that can be executed by a computer connected to an inkjet recording apparatus that includes a sensor that outputs a detection signal and a control unit that executes a recording process for recording an image on a sheet,
In the recording process for recording an image on a sheet,
A detection process for detecting the end position based on the detection signal;
A determination process for determining the length in the width direction of the landing area, which is an area where the ink ejected to the recording unit is landed, and includes an in-sheet area and an out-sheet area;
A conveying process for conveying the sheet to the conveying unit;
Causing the computer to execute a discharge process for causing the recording unit to discharge ink toward the landing area of the sheet conveyed in the conveyance process, a plurality of times,
In the determination process up to n-1 (where n> 1 natural number) times, the landing area is determined to be the first width,
In the n-th and subsequent determination processes, the landing area is set to a second shorter than the first width in response to the amount of deviation of the end position detected in the first and n-th detection processes being less than a threshold value. A program that determines the width. According to a conveyance unit that conveys the sheet in the conveyance direction, a recording unit that records an image on the sheet by discharging ink, and an end position in the width direction that intersects the conveyance direction of the sheet conveyed by the conveyance unit An image recording method executed by an inkjet recording apparatus including a sensor that outputs a detected signal and a control unit that executes a recording process for recording an image on a sheet,
A detection process for detecting the end position based on the detection signal;
A determination process for determining the length in the width direction of the landing area, which is an area where the ink ejected to the recording unit is landed, and includes an in-sheet area and an out-sheet area;
A conveying process for conveying the sheet to the conveying unit;
A discharge process for discharging the ink to the recording unit is performed a plurality of times toward the landing area of the sheet conveyed in the conveyance process,
In the determination process up to n-1 (where n> 1 natural number) times, the landing area is determined to be the first width,
In the n-th and subsequent determination processes, the landing area is set to a second shorter than the first width in response to the amount of deviation of the end position detected in the first and n-th detection processes being less than a threshold value. An image recording method that determines the width.

Images