JP2015163454A - printer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a printer capable of starting printing onto a printing medium at a relatively early stage after detecting an end portion of the printing medium.SOLUTION: A detection end position x1 outside a sheet P is set from a detection start position x0 set to a proximity position inside the sheet P with respect to a side end position xe1 determined on the basis of size information of the sheet P, a carriage 22 is moved from the detection start position x0 to the detection end position x1, and the side end position xe1 is detected by a sheet width sensor 56 in the course of movement thereof. An acceleration start position p0 in a first pass executed subsequent to side end detection drive and the detection end position x1 are compared, and the acceleration start position p0 is set to the detection end position x1 when the acceleration start position p0 is positioned closer to a carriage travelling direction side at the time of the side end detection drive than the detection end position x1. On this account, the movement of the carriage 22 for printing in the first pass from a stop position where the side end detection drive is stopped can be started.

Description

  The present invention relates to a printing apparatus having a function of detecting an end portion of a print medium.

  In this type of printing apparatus, printing is performed on a print medium such as fed paper by a print head. For example, in a serial type printing apparatus, the print head moves in the scanning direction together with the carriage, and prints an image or the like by ejecting ink onto the surface of the paper during the movement.

  In addition, the edge of the fed paper in the scanning direction (width direction) so that an image or the like can be correctly printed on the paper even if the paper is misaligned in the scanning direction. A printing apparatus having a function of detecting (side end) with a sensor is known (for example, Patent Document 1). For example, in Patent Document 1, the scanning start position of a carriage equipped with a sensor is set to a position closer to the end of the sheet on the inner side in the sheet width direction determined from the sheet size information, and the scanning end position is determined based on the sheet size information. It is set at a position near the edge of the paper outside in the direction. The carriage is moved from the scanning start position to the scanning end position in the scanning direction toward the outside of the sheet, and the end of the sheet is detected by the sensor during the movement.

JP-A-2004-182361 (for example, paragraphs [0067] to [0069], FIG. 10, FIG. 12, etc.)

  By the way, in the carriage scan for printing performed after the end detection operation is completed, when the carriage has reached the necessary speed when the print start position determined from the print data is reached, the print start position is The run-up distance to reach is required. Then, it is necessary to start scanning of the carriage from an acceleration start position (carriage activation position) that can secure a running distance.

  If the acceleration start position is located closer to the carriage movement direction during the edge detection operation than the carriage detection end position, the carriage that has stopped after the edge detection operation has been stopped from the detection end position to the acceleration start position. Must be moved. Therefore, one operation for moving the carriage from the detection end position to the acceleration start position is required between the edge detection operation and the printing operation, and the acceleration and deceleration of the carriage when performing this one operation is wasted. It was broken. Therefore, after detecting the edge of the sheet, the waiting time until printing on the sheet is started is relatively long, which causes a decrease in printing throughput.

  SUMMARY An advantage of some aspects of the invention is that it provides a printing apparatus that can start printing on a print medium relatively early after detecting an end of the print medium. is there.

Hereinafter, means for solving the above-described problems and the effects thereof will be described.
A printing apparatus that solves the above problem includes a print head that prints on a print medium, and a detection unit that detects an end portion in a direction that intersects the conveyance direction of the print medium, and intersects the conveyance direction of the print medium. A carriage that is scanned in a scanning direction; a transport unit that transports the print medium to an area in which the carriage is scanned; and a control unit that controls the printing apparatus. Carriage for performing end detection from an inner detection start position to an outer detection end position and performing printing based on print data on the print medium after the end detection is performed The acceleration start position of the carriage is set as the detection end position when the acceleration start position is outside the detection end position.

  According to this configuration, after the detection of the edge of the print medium is performed, the acceleration of the carriage is performed when the acceleration start position of the carriage for performing printing based on the print data on the print medium is outside the detection end position. The start position is set as the detection end position. Therefore, when edge detection is performed from the detection start position inside the edge position of the print medium toward the detection end position outside, the acceleration of the carriage is started from the detection end position and printing based on the print data is performed. It can be carried out. Therefore, it is not necessary to move the carriage stopped at the detection end position from the detection end position to the acceleration start position when performing printing based on the print data. Therefore, after the end of the print medium is detected, printing on the print medium can be started relatively early.

  The printing apparatus is configured such that the longer the moving distance of the carriage, the higher the speed of the carriage. When the detection start position is the first detection start position, the first detection start position and the detection A first required time required for the carriage to move at a first speed determined from the first movement distance as a first movement distance to the end position, and a first detection start position longer than the first movement distance. The second required time required for the carriage to move from the second detection start position to the detection end position at a second speed determined from the second movement distance when the second detection start position is changed to two movement distances. And when the first required time is shorter than the second required time, the detection start position is held at the first detection start position, and the second required time is longer than the first required time. Is shorter than it is preferable to change the detection start position from the first detection start position to the second detection start position.

  According to this configuration, the first required time required for the carriage to move at the first speed determined from the first movement distance is obtained as the first movement distance from the first detection start position to the detection end position. In addition, when the first detection start position is changed to a second detection start position that can be a second movement distance that is longer than the first movement distance, the carriage is detected at a second speed determined from the second movement distance from the second detection start position. A second required time required to move to the end position is obtained. Then, the first required time and the second required time are compared. When the first required time is shorter than the second required time, the first detection start position is held. On the other hand, when the second required time is shorter than the first required time, the first detection start position is changed to the second detection start position. Therefore, when the first detection start position is changed to the second detection start position, the time required for the carriage to move to the detection end position for detecting the end portion can be shortened. For this reason, after detecting the edge, printing based on the print data can be started promptly.

  In the printing apparatus, before the carriage moves to the detection start position, the carriage is disposed at a standby position outside the print medium in the scanning direction, and the control unit is configured to transfer the print medium to the print start position. It is preferable that detection of the edge is executed, and the movement of the carriage to the detection start position is started before the print medium is transported to the print start position and stopped.

  According to this configuration, the carriage completes moving to the detection start position until the print medium has been transported to the print start position. For example, if the carriage reaches the detection start position after the conveyance of the print medium to the print start position is completed, the carriage moves from the detection start position after the conveyance of the print medium to the print start position is completed. There is a waiting time until the start, and this waiting time delays the start time of printing on the printing medium that is performed after the end portion is detected. However, since the carriage completes the movement to the detection start position by the time the print medium has been transported to the print start position, this type of waiting time can be reduced to zero or shorter, so that printing can be started relatively early.

  In the printing apparatus, the control unit causes the carriage to reach the detection start position during conveyance of the print medium being conveyed to the print start position, and finishes conveying the print medium to the print start position. It is preferable that the movement of the carriage from the detection start position is started before the end portion is detected during the movement of the carriage.

  According to this configuration, the carriage reaches the detection start position during the conveyance of the print medium to the print start position, and the carriage starts from the detection start position before the print medium is conveyed (that is, during the conveyance of the print medium). Start moving. For this reason, the conveyance of the print medium to the print start position and the movement of the carriage from the detection start position are performed by overlapping a part of the operation timing. Therefore, the waiting time from when the print medium stops at the print start position to when printing on the print medium is started by the carriage that has detected the end portion can be shortened.

  Further, in the printing apparatus, the control unit estimates a time required for the carriage to move from the detection start position to the end position, and when the carriage reaches the end position, the print medium is It is preferable that movement of the carriage from the detection start position is started at a timing when the print medium is stopped at the print start position, and the end portion of the print medium in the stop state is detected.

  According to this configuration, the time required for the carriage to reach the end position from the detection start position is estimated. When the carriage reaches the end position, movement of the carriage from the detection start position is started at a timing when the print medium is stopped at the print start position. Therefore, since the edge part of the printing medium in a stopped state can be detected, the edge position can be detected with high position detection accuracy. Therefore, the edge of the print medium can be detected with a relatively high position detection accuracy, and printing on the print medium can be started relatively early after the print medium is conveyed to the print start position.

  In the printing apparatus, the control unit may detect an end of a print medium having a minimum width in the scanning direction when the information on the print medium is indefinite. It is preferable to move to the third detection start position, and start the movement of the carriage from the third detection start position to detect the end portion.

  According to this configuration, when the information on the print medium is indefinite, the carriage is moved to the third detection start position where the end of the print medium having the minimum width in the scanning direction can be detected, and the third detection start position is The movement of the carriage is started and the end portion is detected. Therefore, it is possible to reduce the frequency of failure in which the edge portion is not detected due to indefinite information on the print medium.

  In the printing apparatus, when the print medium is in a non-detection state at the detection start position and the detection of the end of the print medium fails, the control unit moves the carriage in the scanning direction. It is preferable that the end of the print medium having the minimum size is moved to a detectable third detection start position, and the carriage is started to move from the third detection start position to detect the end.

  According to this configuration, when the print medium is not detected at the detection start position and the end of the print medium fails to be detected, the carriage is moved to the end of the print medium having the minimum width (minimum width) in the scanning direction. Is moved to a detectable third detection start position. Then, the movement of the carriage is started from the third detection start position, and the end portion is detected. Therefore, even if the edge detection fails, the carriage starts to move from the third detection start position because the edge cannot be detected by the movement from the initial detection start position. Since the edge is detected, the edge can be detected even for a print medium having a size that cannot be detected by the movement from the initial detection start position.

  Furthermore, in the printing apparatus, the control unit continues the state in which the detection unit detects the print medium while the carriage moves from the detection start position to the detection end position, and the end of the print medium is continued. When the detection of the part fails, it is preferable that the detection end position is changed to a position on the extension in the traveling direction of the carriage when the end part is detected.

  According to this configuration, the detection unit continues to detect the print medium while the carriage moves from the detection start position to the detection end position, and the detection end position is detected when the detection of the edge of the print medium fails. Is changed to a position on the extension in the traveling direction of the carriage for detecting the end. Therefore, even if the print medium has an excessive width that cannot be detected by moving the carriage to the initial detection end position, the carriage moves to the extended detection end position after the change, so that the end of the print medium can be detected. Part can be detected.

  In the printing apparatus, the control unit may move the carriage when the end is detected if the end position where the detection unit detects the end is past the acceleration start position. On the other hand, if the end position does not pass the acceleration start position, it is preferable to wait for the carriage to reach the acceleration start position before stopping the movement of the carriage.

  According to this configuration, if the end position where the detection unit detects the end is past the acceleration start position, the carriage stops when the end is detected. If the detected end position does not pass the acceleration start position, the carriage stops after reaching the acceleration start position. Therefore, compared to the configuration in which the carriage is always moved to the detection end position, when the acceleration start position is positioned before the detection end position, the carriage stops when the end portion is detected. Printing on the print medium by the carriage that starts moving can be started earlier.

1 is a perspective view illustrating a printer according to an embodiment. FIG. 3 is a block diagram illustrating an electrical configuration of the printer. The schematic plan view which shows a support stand and a carriage. The schematic diagram explaining the setting method of the detection start position in a side edge detection drive, and a detection end position. The schematic diagram explaining the method to change the detection start position in side edge detection drive. The block diagram which shows the function structure of a computer. The side edge detection drive when the paper is indefinite will be described, (a) is a detection preparation scan, and (b) is a schematic plan view showing the side edge detection drive. Side edge detection drive when the paper is not indefinite will be described, (a) is detection preparation scanning, (b) is side edge detection drive, (c) is side edge detection drive when the detection end position is changed, (d ) Is a side plan detection drive when the detection start position is changed, and (e) is a schematic plan view showing a first pass printing operation. (A), (b) is a schematic plan view explaining the side edge detection drive executed when the side edge detection fails due to the paper size being smaller than expected. (A), (b) is a schematic plan view explaining the side edge detection drive executed when the side edge detection fails due to the paper size being larger than expected. The flowchart which shows an edge part detection control program. Same flowchart.

Hereinafter, an embodiment embodied in a printer which is an example of a printing apparatus will be described with reference to the drawings.
The printer 11 shown in FIG. 1 is a multifunction machine having both a scan function, a print function, a copy function, and a facsimile function. The printer 11 includes an apparatus main body 12 having a substantially rectangular parallelepiped shape, and an operation panel 13 provided on the front surface of the apparatus main body 12 (the front surface of the right hand in FIG. 1). The operation panel 13 is provided with a display unit 14 and an operation unit 15 including a plurality of operation switches. The operation unit 15 includes a power switch 15a, a print start button 15b, a mode switching button 15c for switching various modes, and the like. Note that the display unit 14 of the present embodiment is a touch panel that can select and input the content corresponding to the button displayed on the screen, and this touch panel function also constitutes a part of the operation unit.

  As shown in FIG. 1, the lower part of the front surface of the apparatus main body 12 can accommodate a plurality of sheets (for example, values in the range of 100 to 1000 sheets) (two in the example of FIG. The feeding cassettes 16 and 17 are mounted in a detachable manner with respect to the respective accommodating recesses individually provided at corresponding positions of the apparatus main body 12. Further, a manual feed tray 19 disposed in an inclined posture is provided on the back side of the apparatus main body 12.

  The sheet P fed from one of the plurality of feeding cassettes 16, 17 is reversed along a sheet reversing path (not shown) disposed on the back side in the apparatus main body 12, and then the transport direction Y Are conveyed to the printing start position. In contrast, the paper P fed from the feed tray 19 is transported to the print start position via a relatively short feeding distance. Therefore, the sheet P fed from one of the feeding cassettes 16 and 17 is skewed slightly compared to the sheet fed from the feeding tray 19 and the scanning direction X intersecting the transport direction Y. Is more likely to occur.

  As shown in FIG. 1, a carriage 22 that is reciprocally moved by being guided by a guide shaft 21 that extends in the scanning direction X (the width direction in this example) is provided in the apparatus main body 12. The print head 23 disposed below the carriage 22 has a plurality of nozzles capable of ejecting ink droplets onto the conveyed paper P (indicated by a two-dot chain line in FIG. 1). While the carriage 22 reciprocates in the scanning direction X, ink droplets are ejected from the nozzles during the movement, whereby a document or image is printed on the surface of the paper P. The printed paper P is sent in the transport direction Y and discharged from a discharge port 24 that opens to the front middle position of the apparatus main body 12. For example, the printed paper P is stacked on a slide-type discharge stacker 25 (discharge tray) in an extended state. Is done.

  The printer 11 is a color printer as an example. The print head 23 stores ink of a plurality of colors (for example, the number of colors within a range of 4 to 10 colors) including cyan (C), magenta (M), yellow (Y), and black (K), for example. A plurality of nozzle rows are formed in the same number as the ink color that ejects ink supplied from an ink supply source (for example, an ink cartridge or an ink tank) for each color. The printer 11 may be a monochrome printer capable of printing only in gray scale.

  In the printer 11 shown in FIG. 1, the lower part of the apparatus main body 12 is an image forming unit 26 that forms an image on the paper P by the above-described printing, and a scanner unit 27 is disposed on the upper side. The scanner unit 27 includes a document table (not shown) having a document reading surface on the upper surface of the apparatus body 12 and a cover 28 provided on the upper side of the apparatus body 12 so as to be openable and closable with respect to the document table. An automatic document feeding unit 29 (auto document feeder) capable of setting a plurality of documents and feeding them one by one to the scanner unit 27 is provided on the upper portion of the cover 28.

  Next, the electrical configuration of the printer 11 will be described with reference to FIG. As shown in FIG. 2, the printer 11 includes a controller 30, an operation panel 13, a scan engine 31, a print engine 32, and the like as an example of a control unit that performs overall control. The printer 11 includes a communication interface (hereinafter referred to as “communication I / F 35”). The scan engine 31 includes a scanning head having a line sensor, an electric motor that is a power source of the scanning head, a lamp that illuminates a reading position of the line sensor, and the like.

  The print engine 32 shown in FIG. 2 includes a feed motor serving as a power source for feeding the paper P from the print head 23, a carriage motor 36 serving as a power source for the carriage 22, the feed cassettes 16 and 17, the feed tray 19, and the like. 37, a transport motor 38 serving as a power source for transporting the fed paper P, a cleaning device 39 for cleaning the print head 23, and the like. The controller 30 controls the print engine 32 based on the print job data PD to print on the paper P. Further, the controller 30 drives and controls the scan engine 31 and the print engine 32, and causes the print engine 32 to print an image based on the document data read by the scan engine 31, thereby “copying” the document.

  In addition, the controller 30 drives and controls the print engine 32 based on the print job data PD received from the host device 100 via the communication I / F 35 to print a document, an image, or the like. The host device 100 may be a personal computer, a personal digital assistant (PDA (Personal Digital Assistants)), a tablet PC, a smartphone, or the like.

  The controller 30 shown in FIG. 2 includes a computer 40 that constitutes an example of a control unit. The computer 40 includes a CPU 41 (central processing unit), an ASIC 42 (Application Specific IC), a nonvolatile memory 43 and a RAM 44 as an example of a storage unit. The nonvolatile memory 43 includes various programs including a control program shown in FIGS. 11 and 12 for performing a side edge detection process for detecting a side edge position (an example of an edge position) of the paper P, and a side edge detection. Various data including speed control data VD (see FIG. 6) used for processing is stored.

  As shown in FIG. 2, in the apparatus main body 12, a feeding drive unit 46 that feeds the paper P one by one from the feeding cassettes 16 and 17 using the feeding motor 37 as a power source is provided for each feeding cassette. ing. Each feeding drive unit 46 includes a feeding roller 48 (pickup roller) that feeds the uppermost one of the sheet groups set in the feeding cassettes 16 and 17 to the downstream side in the feeding direction. Further, the feeding roller 49 provided in the vicinity of the base end portion of the feeding tray 19 is rotationally driven by the power of the feeding motor 37, so that the uppermost sheet in the sheet group on the feeding tray 19 is driven. Is sent downstream in the feeding direction.

  As shown in FIG. 2, the input terminals of the controller 30 detect tray sensors 51 and 52 that can detect the removal and attachment of the feeding cassettes 16 and 17 and the presence or absence of the paper P on the feeding tray 19. A possible paper presence / absence sensor 53 is connected. In addition, a paper detection sensor 55, a paper width sensor 56, a linear encoder 57 and an encoder 58 are electrically connected to the input terminals of the controller 30.

  The paper detection sensor 55 is, for example, a contact type or non-contact type switch type sensor provided at a predetermined position on the feeding path, and detects the leading edge of the fed paper P in the transport direction Y. The paper width sensor 56 is a non-contact sensor provided in the carriage 22 and detects a side edge in the scanning direction X that intersects the transport direction Y of the paper P. The paper width sensor 56 of this example includes a reflective optical sensor having a light emitting unit capable of emitting light and a light receiving unit capable of receiving reflected light of light emitted from the light emitting unit. Of course, the paper width sensor 56 may be a transmissive optical sensor, and the side edge of the paper P may be detected by blocking the light passing between the light emitting unit and the light receiving unit on both sides of the conveyance path.

  The linear encoder 57 outputs a pulse signal having a number of pulses proportional to the amount of movement of the carriage 22, that is, the amount of rotation of the carriage motor 36. The encoder 58 outputs a pulse signal having a number of pulses proportional to the rotation amount of the transport motor 38.

  When the paper detection sensor 55 detects the leading edge of the paper P, the controller 30 causes the PF counter 76 (see FIG. 6) to count the number of edges of the pulses from the encoder 58. For this reason, the controller 30 acquires from the PF counter 76 a count value corresponding to the position (transport position) in the transport direction Y of the paper P with the position when the leading edge of the paper P is detected by the paper detection sensor 55 as the origin. To do.

  The controller 30 drives the carriage motor 36 to monitor the detection voltage input from the paper width sensor 56 when the carriage 22 is moving in the scanning direction, and the carriage when the detection voltage falls below a predetermined threshold value. The side edge position of the paper P is acquired from the position (that is, the count value of the CR counter 75 shown in FIG. 6). In the present embodiment, the position of the paper width sensor 56 in the scanning direction X is the carriage position.

  Next, the configuration of a printing unit that performs printing on the paper P will be described with reference to FIG. As shown in FIG. 3, a long support base 60 extending along the scanning direction X is provided at a position facing a region where the carriage 22 is scanned (also referred to as “scanning region”) in the printing unit. ing. The support base 60 includes an upstream support surface portion 61 positioned upstream in the transport direction Y, an intermediate support surface portion 62 positioned downstream of the upstream support surface portion 61 in the transport direction Y, and an intermediate support surface portion 62. On the other hand, it has a downstream support surface portion 63 located on the downstream side in the transport direction Y.

  As shown in FIG. 3, the support surface portions 61 to 63 project from the first rib 64, the second rib 65, and the third rib projecting upward in the vertical direction (front side in FIG. 3) and extending along the transport direction Y. A plurality of ribs 66 are formed at regular intervals in the scanning direction X. The sheet P (see FIG. 1) is transported in the transport direction Y with the back surface supported by the first to third ribs 64 to 66. In FIG. 3, a print area PA that is the maximum area in which the liquid (ink) is ejected by the print head 23 in the scanning direction X is set on the support base 60.

  The linear encoder 57 includes a code plate 57a having a large number of slits that open at a constant pitch along the scanning direction X, and a sensor 57b that receives light emitted from the light projecting unit and passed through the slit by the light receiving unit. The sensor 57b outputs a pulse signal having a number of pulses proportional to the amount of rotation of the carriage motor 36.

  As shown in FIG. 3, a transport roller pair 67 and a discharge roller pair 68 are provided on the upstream side and the downstream side of the support base 60 in the transport direction Y, respectively. The paper P is transported in the transport direction Y while being nipped (niped) between both roller pairs 67 and 68 that are rotated by the power of the transport motor 38. In the present embodiment, an example of the transport unit is configured by the components of the transport system such as the feed motor 37, the feed rollers 48 and 49, the transport motor 38, the transport roller pair 67, and the discharge roller pair 68. .

  During the feeding operation (cueing operation) for transporting the paper P to the printing start position in the transport direction Y, the computer 40 drives the carriage motor 36 to move the carriage 22 from the home position HP as an example of the standby position. Detection preparation scanning is performed to move to the detection start position of the side edge detection drive for detecting the side edge of P. Further, the computer 40 drives the carriage motor 36 to move the carriage 22 in the scanning direction X in the direction toward the home position HP before the completion of the feeding operation, so that the detection signal from the paper width sensor 56 in this moving process. The side edge detection driving for detecting the side edge position of the paper P is started based on the above.

  In the serial type printer 11, a printing operation in which ink is ejected from the nozzles of the print head 23 onto the paper P while the carriage 22 is reciprocated in the scanning direction X, and the transport amount of the paper P in the transport direction Y to the next print position. A document, an image, or the like is printed on the paper P by alternately repeating the feeding operation for conveying only the paper. The side of the paper P detected by the side edge detection drive is used to determine the print start position (ejection start position) at which ink ejection starts from the print head 23 for each pass in which the carriage 22 moves once in the scanning direction X. An end position is used. For this reason, it is possible to suppress the positional deviation in the scanning direction X of the print image with respect to the paper P.

  Next, with reference to FIG. 4, a method for determining the detection start position and the detection end position in the side edge detection drive will be described. Note that the side edge on the home position side (the right side in FIG. 4) among the side edges on both sides in the width direction (scanning direction X) of the paper P shown in FIG. 4 is referred to as a “first side edge SE1”. Further, the side end opposite to the first side end (left side in FIG. 4) is referred to as “second side end SE2”.

  The printer 11 of the present embodiment has a draft mode (high-speed print mode), a high quality mode (low-speed print mode), a double-sided print mode, and the like as print modes. The printer 11 employs two types of side edge detection methods as a method for detecting the side edge position of the paper P depending on the print mode. The first method is a method of determining the position of the first side end SE1 by detecting the first side end SE1 in the width direction of the paper P. In the second method, both the first side edge SE1 and the second side edge SE2 in the width direction of the paper P are detected, and the paper width (the length in the width direction of the paper) and the second side edge data are detected based on the data of both side edge positions. This is a method for determining the position of the one side end SE1.

  Information on which print mode of the plurality of print modes takes the first method and which other print mode takes the second method is stored in the nonvolatile memory 43 in advance. The computer 40 performs first side edge detection driving of the paper P performed at the time of feeding based on the print mode selected by the user through the operation unit 15 or specified by the print condition information in the print job data PD. Whether to execute by the method of (2) or the second method is determined.

  In the present embodiment, since the contents of the side edge detection driving for detecting the position of the first side edge SE1 are the same in the first method and the second method, the side edge detection driving by the first method will be described in detail below. .

  For the paper width sensor 56, the upstream support surface 61 is a dark area, and the paper P is a bright area. When the spot light of the paper width sensor 56 crosses the side edge of the paper P, the amount of reflected light of the paper width sensor 56 changes greatly, the amount of received light decreases, and the detection signal value of the paper width sensor 56 crosses the threshold value. The position of the first side edge SE1 of the paper P is detected based on the count value of the CR counter 75.

  Before the start of the side edge detection drive, the carriage 22 is located between the home position HP and the width center position xc (center position) of the paper P and the first side edge SE1 (hereinafter also simply referred to as “side edge SE1”). It moves to the detection start position x0. Then, the carriage 22 moves from the detection start position x0 to the detection end position x1. Here, the detection start position x0 and the detection end position x1 are obtained for each paper size by the computer 40. The computer 40 is assumed to be based on the paper width corresponding to the paper size determined from the printing condition information in the print job data PD or the paper size information in the printing condition information input by operating the operation unit 15 by the user. The position of the end SE1 (hereinafter also referred to as “side end position xe1”) is obtained. Then, the computer 40 sets the detection start position x0 at a predetermined distance (predetermined number of steps) from the side end position xe1 to the plus side in the scanning direction (on the opposite home position side on the left side in FIG. 4). In FIG. 4, the detection end position x1 is set at a predetermined distance on the right side (home position side). Here, the predetermined distance is set to a distance that is larger than the assumed maximum error between the assumed and actual side end positions xe1 and as short as possible. The predetermined distance is set to a predetermined value within a range of 5 to 20 mm as an example. For this reason, for example, in the paper P having a size of A5 or larger, the detection start position x0 is positioned closer to the side end SE1 than the width center position xc of the paper P.

  As shown in the upper part of FIG. 4, the speed profile when the carriage 22 moves includes an acceleration area, a constant speed area, and a deceleration area. In order for the carriage speed to reach the constant speed V1, an acceleration distance Sa1 is required as a running distance, and a deceleration distance Sd1 is required before the carriage speed decelerates and stops. For this reason, the maximum speed Vmax (constant speed V1 in the example of the figure) that can be set for the carriage 22 is determined by the first movement distance from the detection start position x0 to the detection end position x1.

  In this embodiment, a plurality of types of speed profiles of the carriage 22 are prepared with different maximum speeds Vmax. In this case, the minimum required moving distance (shortest moving distance) (sum of acceleration distance and deceleration distance) is determined for each maximum speed Vmax. When the moving distance of the carriage 22 is determined, the computer 40 selects the speed profile data in which the maximum speed Vmax corresponding to the longest shortest moving distance (the minimum number of drive steps) that is less than the moving distance is set, and the selected The carriage motor 36 is speed controlled according to the speed profile data.

  Next, as shown in the lower part of FIG. 4, the carriage 22 that has finished the side edge detection drive starts moving the carriage 22 for the first pass printing. In this example in which printing during acceleration in which printing is started at the printing start position p1 in the middle of the acceleration process of the carriage 22 is performed, it is necessary to reach a required target speed when the printing start position p1 is reached. In this case, the acceleration start position p0 of the carriage 22 is given by p0 = p1 + Snp−Sa2. Here, p1 is a printing start position, Snp is a printing distance during acceleration (number of steps), and Sa2 is an acceleration distance (number of steps) necessary to reach a constant speed Vc (maximum speed). In this example, printing is performed even during acceleration / deceleration, but printing may be performed only in a constant speed range.

  When the acceleration start position p0 shown in the lower part of FIG. 4 is located closer to the carriage traveling direction side (right side in FIG. 4) than the detection end position x1 shown in the upper part of the figure (p0 <x1), acceleration starts. The position p0 is set to the detection end position x1. For this reason, it is possible to start the movement (scanning operation) of the carriage 22 for the first pass printing from the stop position after the end of the side edge detection drive.

  The carriage speed V1 (first speed) at the time of side edge detection driving is driven by the computer 40 within the number of steps (x0-x1) that is the first movement distance from the speed control data VD (see FIG. 6). Set by selecting the maximum possible speed. Specifically, the nonvolatile memory 43 includes speed control data VD including a plurality of types of speed profile data groups in which the maximum speed of the carriage 22 and the shortest movement distance (number of steps) that can be driven at the maximum speed are associated with each other. (See FIG. 6) is stored. The computer 40 refers to the speed control data VD and selects the maximum speed that can be driven with the shortest moving distance within the number of steps (x0−x1) as the carriage speed V1. Then, the computer 40 drives the carriage motor 36 to move the carriage 22 from the detection start position x0 to the detection end position x1 at the first speed V1 (constant speed), thereby performing side edge detection drive.

  Next, a setting process for changing the detection start position x0 will be described with reference to FIG. The first movement distance (x0−x1) for moving the carriage from the detection start position x0 to the detection end position x1 is made longer, and the carriage speed V2 (second speed) is higher than the carriage speed V1 (first speed). By securing the second movable distance that can be moved, the time required for the side edge detection drive may be shortened.

  The computer 40 obtains the maximum carriage speed V1 (first speed) that can be driven with the shortest movement distance within the number of steps (x0−x1) of the first movement distance, and the carriage 22 performs the first movement at the first speed V1. A first required time T1 for moving the number of distance steps (x0−x1) is calculated. Specifically, the computer 40 acquires the acceleration time Ta1 and the deceleration time Td1 using the speed profile data corresponding to the first speed V1, and calculates the sum of the acceleration time Ta1, the deceleration time Td1, and the constant speed time Tc1. First required time T1 is obtained (T1 = Ta1 + Td1 + Tc1). The constant speed time Tc1 is given by Tc1 = ((x0−x1) −Sa1−Sd1) / V1. Here, Sa1 is an acceleration distance, and Sd1 is a deceleration distance.

  Further, the computer 40 refers to the speed control data VD, and determines the carriage speed V2 (second speed) higher than the carriage speed V1 and the shortest moving distance (minimum driving step number SB) corresponding to the second speed V2. select. The computer 40 calculates the second required time T2 when the carriage 22 moves at the second speed V2 and the minimum driving step number SB that is the second movement distance. That is, the computer 40 refers to the speed profile data of the minimum driving step number SB (= Sa3 + Sd3) corresponding to the second speed V2 shown in the lower part of FIG. 5, acquires the acceleration time Ta3 and the deceleration time Td3, The sum of Ta3 and Td3 is calculated to obtain the second required time T2 (T2 = Ta3 + Td3).

  If the second required time T2 is shorter than the first required time T1 (if T1> T2 is established), the computer 40 determines the movement distance to the set detection end position x1 as the second movement distance SB (minimum). The second detection start position x3 that can be made the number of drive steps) is calculated. When the detection end position x1 is the acceleration start position p0 shown in the example of FIG. 5, the second detection start position x3 is calculated by x3 = p0 + SB. When the detection end position x1 is the initial set value, the second detection start position x3 is calculated by x3 = x1 + SB. The second detection start position x3 is set as the detection start position x0 (x0 = x3), and the carriage speed is changed from the first speed V1 to the second speed V2.

  On the other hand, in the case of the second method, after performing the side edge detection driving for detecting the first side edge SE1 by the above method, the carriage 22 is moved to the detection start position x0 in the vicinity of the second side edge inside the paper P. Move. Then, the carriage 22 is moved to the plus side in the scanning direction X from the detection start position x0 to the detection end position x1 set in the area outside the paper P, so that the paper side sensor 56 causes the second side end to move in the middle of the movement. SE2 is detected. When the first pass printing operation is started from the non-home position side, the acceleration start position p0 is changed to the detection end position x1, and the second speed V2 higher than the first speed V1 is changed. If the required time is short, the second detection start position x3 corresponding to the second movement distance SB (minimum number of drive steps) with a longer movement distance is set as the detection start position in the same manner.

  FIG. 6 shows a functional configuration related to edge detection control constructed in the computer 40. The computer 40 includes a print control unit 71 that controls printing control and edge detection control, a setting unit 72 that sets a detection start position and a detection end position in the side edge detection drive, a paper P feeding operation, and a side edge detection drive. Are provided with a superposition calculation unit 73, a detection processing unit 74, a CR counter 75, a PF counter 76, and a storage unit 77 for calculating a condition for partially superimposing the operation timings. The storage unit 77 is composed of a part of the storage area of the nonvolatile memory 43, for example, and stores speed control data VD.

  The speed control data VD includes a data group including a plurality of types of speed profile data in which the shortest movement distance (minimum driving step number) and the maximum speed are associated with each other. The print control unit 71 of the computer 40 sets the first speed V1 corresponding to the longest shortest moving distance among the shortest moving distances within the first moving distance (number of steps (x0−x1)) from the speed control data VD. Select a speed profile. The speed profile data includes, for example, table data in which the movement distance of the carriage 22 from the acceleration start position p0 (origin) and the target speed are associated with each other. The computer 40 refers to the table data each time the carriage 22 advances the unit distance (number of unit steps) Δx, acquires the target speed corresponding to the moving distance at that time, and uses the acquired target speed to perform the carriage motor 36. Is controlled by feedback control or feedforward control.

  Further, the print control unit 71 can manage whether or not it is the first page in the print job based on the input print job data PD, or can replace the paper P by the user based on signals from the sensors 51 to 53. To detect specific operations. In this example, this operation is detected by detecting the removal and attachment of the feeding cassettes 16 and 17. Further, the computer 40 acquires at least information regarding the paper size (hereinafter referred to as “paper size information”) of the paper type and the paper size of the paper P as one of the print condition information together with a print job command. To do.

  In the present embodiment, the side edge detection driving for the paper P is performed only on the first paper P in one print job. This is because the paper type, paper size, and feeding source (feed cassette 16, 17 or feed tray 19) are the same in one print job, and between the sheets P fed by the same feed path. This is because the skew in feeding and the positional deviation in the width direction tend to be approximately the same. The print control unit 71 includes a paper flag for managing whether or not the paper P to be fed is the first paper in the print job. When the paper P is the first paper P in the print job, the paper flag Is turned on (“1”), and the paper flag is turned off (“0”) when the second and subsequent sheets P are in the print job. Then, the print control unit 71 performs side edge detection driving for the paper P fed at that time when the paper flag is on, and does not perform side edge detection driving when the paper flag is off.

  Further, when the computer 40 detects the removal and installation of the feeding cassettes 16 and 17 or detects that the paper is set again after the paper on the feeding tray 19 is removed, the detection is performed. Assume that the paper P that is fed first from the feeding source later is “undefined”. Here, “indefinite” means that there is a possibility that the paper size at the feeding source has been changed, the setting information regarding the paper size up to that time may be different from the actual paper P, and the paper size information The state that cannot be confirmed that is correct. The print control unit 71 of the computer 40 includes an indeterminate flag for managing whether or not the sheet P of the feeding source is undefined for each feeding source. When one of the sensors 51 to 53 detects an operation with the possibility of replacing the paper P at one of the sensors 51 to 53, the print controller 71 feeds the first paper P after the operation is detected. Until the detection driving is performed, the indefinite flag corresponding to the feeding source is turned on ("1"). On the other hand, when the print control unit 71 finds that the paper size information is correct from the position of the side edge detected by the side edge detection drive performed after detecting the operation, the print control unit 71 turns off the indefinite flag corresponding to the feeding source ( “0”).

  When the paper is indefinite, the setting unit 72 can detect the detection start position in the side edge detection drive as well as the side edge SE1 having the smallest width in the scanning direction X among the paper sizes assumed to be used in the printer 11. A center position xc in the width direction of the sheet P (hereinafter also referred to as “width center position xc”) is set, and the detection end position is set to the detection limit position xe. Here, the detection limit position xe is a detection end position at which the side edge SE1 of the maximum width paper that is expected to be used in the printer 11 can be detected. For example, the detection limit position xe is set to a position slightly on the plus side in the scanning direction X from the home position HP or to the home position HP.

  The computing unit 81 computes the detection start position x0 and the detection end position x1 based on the paper size information. When the paper P is not “indefinite”, the calculation unit 81 first sets the side edge position xe1 assumed from the paper width determined from the paper size information, for example, from the paper width center position xc to a half of the paper width Wp. Is calculated by subtracting the value of (xe1 = xc−Wp / 2). Then, the calculation unit 81 calculates a position a predetermined distance (predetermined number of steps) on the plus side in the scanning direction with respect to the side end position xe1 as the detection start position x0, and sets the position on the minus side in the scanning direction with respect to the side end position xe1. The position of the distance is calculated as the detection end position x1. Here, the predetermined distance is set to a value at which the detection start position x0 is closer to the side edge SE1 than the width center position xc of the paper P, for example, a predetermined value within a range of 5 to 30 mm. Then, the setting unit 72 sets the detection start position x0 and the detection end position x1 as setting values used in the side edge detection driving for the target paper P.

  Further, the calculation unit 81 analyzes print data for one pass used for print control for ejecting ink while the carriage 22 scans once, obtains a print start position p1 (first dot position), and starts printing. An acceleration start position p0 (carriage activation position) at which the carriage 22 can be accelerated to the speed required for the position p1 is calculated. The determination unit 82 determines whether or not the acceleration start position p0 is positioned closer to the carriage traveling direction during the side edge detection drive than the detection start position x0 (x0> p0 is satisfied). The setting unit 72 maintains the initial detection end position x1 when x0> p0 is not established, and sets the acceleration start position p0 as the detection end position x1 when x0> p0 is established (x1 = p0).

  Further, the calculation unit 81 refers to the speed control data VD, and the maximum carriage speed V1 that can be used for the movement of the first movement distance (x0−x1) (number of steps) determined from the detection start position x0 and the detection end position x1. (First speed) is acquired, and a first required time T1 required to move the carriage 22 at the first speed V1 by the first movement distance (x0-x1) is calculated. Further, the calculation unit 81 obtains the shortest moving distance SB (minimum number of driving steps) that can move the carriage 22 at a carriage speed V2 higher than the carriage speed V1, and sends the shortest distance to the carriage 22 up to the detection end position x1. A second detection start position x3 in the case of moving the movement distance SB is obtained (x3 = p0 + SB or x1 + SB). Further, the calculation unit 81 calculates a second required time T2 necessary for moving the carriage 22 at the second speed V2 by the second movement distance SB.

  The determination unit 82 determines whether the second required time T2 is shorter than the first required time T1 (whether T1> T2 is satisfied). The setting unit 72 maintains the initial detection start position x0 when T1> T2 is not established, and sets the second detection start position x3 as the detection start position x0 when T1> T2 is established ( x0 = x3).

  The superposition calculation unit 73 performs ASF / CR superposition control for superimposing at least part of the operation timing of the feeding operation of transporting (feeding) the paper P to the printing start position and the side edge detection drive of the carriage 22. Calculate the necessary control parameters. The printing control unit 71 starts driving the carriage motor 36 at the start timing according to the control parameters before stopping the driving of the feeding motors 37 and 38, thereby feeding the paper P and the side edge of the carriage 22. A part of the operation timing with the detection drive is overlapped.

  In particular, in this example, the detection preparation scan in which the carriage 22 moves from the home position HP to the detection start position x0 is completed in the middle of the feeding operation of the paper P, and from the detection start position x0 that is the stop position of the detection preparation scan. The side end detection driving performed when the carriage 22 starts moving to the minus side in the scanning direction X is started before the paper P finishes the feeding operation. The timing at which the feeding operation of the paper P is completed before the paper width sensor 56 that has started moving together with the carriage 22 before the feeding operation ends reaches the position of the assumed side edge SE1 of the paper P. In addition, a control parameter that defines the drive start timing of the carriage motor 36 is set. For this reason, when the paper width sensor 56 passes the side edge SE1 of the paper P, the paper P is in a stopped state. For example, in consideration of the positional deviation of the side edge SE due to the skew of the paper P, the width direction deviation, etc., the control parameter satisfying the condition that becomes the timing when the paper stops when the paper width sensor 56 detects the side edge SE1 is the overlap calculation. Calculated by the unit 73.

  Specifically, the overlap calculation unit 73 requires the time Tp necessary for the carriage 22 during the side edge detection drive to move from the detection start position x0 to a position immediately before the side edge position xe1 assumed from the sheet size information. Calculate In this example, in particular, a distance obtained by adding a small margin to the maximum deviation amount of the side edge position xe1 due to the skew of the paper P, etc., rather than the distance (number of steps) from the detection start position x0 to the assumed side edge position xe1. Only a short distance Sp is used. Then, the overlay calculation unit 73 calculates a required time Tp when the carriage 22 moves the distance Sp at a speed V1 or V2 determined from the moving distance (x0−x1) at that time. Further, the overlapping calculation unit 73 can specify the transport position that is a short time before the time point when the paper P reaches the print start position in the paper feeding operation, and the remaining transport until the paper P reaches the print start position. An amount ΔFp (hereinafter also referred to as “set value ΔFp”) is calculated as a control parameter.

  Then, the print controller 71 monitors the remaining transport amount ΔF of the paper P during the feeding operation, and when the remaining transport amount ΔF reaches the set value ΔFp, the carriage motor 36 is driven to start the side edge detection drive. To start. As a result, the carriage 22 that starts to move from the home position HP during the feeding operation of the paper P and arrives at the detection start position x0 starts to move from the detection start position x0 before the feeding operation is completed. The side edge detection drive is performed. Thus, the side edge detection driving is started before the feeding operation is finished, and the operation timing of the feeding operation and the side edge detection driving is overlapped during the period during which the carriage 22 moves the distance Sp from the detection start position x0. When the carriage 22 moves from the detection start position x0 by the distance Sp, the paper P feeding operation is completed, and the paper P reaches the print start position and stops. Immediately after the stop of the paper P, the paper width sensor 56 passes through a position facing the side edge SE1. For this reason, the detection of the side edge position xe1 by the paper width sensor 56 is performed on the paper P in the stopped state.

  The CR counter 75 is reset when the carriage 22 is at the origin position, and adds “1” to the count value every time the edge of the pulse signal from the linear encoder 57 is detected when the carriage 22 moves forward. Every time a pal signal edge from the linear encoder 57 is detected during the backward movement, “1” is subtracted from the count value. As a result, the CR counter 75 outputs a count value corresponding to the position (carriage position) of the carriage 22 in the scanning direction X.

  The PF counter 76 conveys the sheet with the first count value indicating the position of the sheet relative to the position (origin) when the leading edge of the sheet is detected by the sheet detection sensor 55 and the sheet conveyance start position as the origin. The second count value indicating the relative position is counted. The PF counter 76 is reset when the paper detection sensor 55 detects the leading edge of the paper P in the transport direction Y, and then counts, for example, the number of pulse edges based on the pulse signal from the encoder 58, thereby making the paper in the transport direction Y. A first count value indicating the position of P is counted. Further, the PF counter 76 is reset at the conveyance start position of the paper P, and then counts, for example, the number of pulse edges based on the pulse signal from the encoder 58, so that the PF counter 76 is moved from the conveyance start position (origin) of the paper being conveyed. A second count value indicating the transport distance is counted. Further, when performing the ASF / CR superposition control, the print control unit 71 grasps the remaining transport amount ΔF until the paper P being fed is transported to the print start position based on the second count value of the PF counter 76. When the remaining transport amount ΔF reaches a set value ΔFp determined from the control parameter, the carriage motor 36 is started to start the side edge detection drive.

  When the detection voltage from the paper width sensor 56 falls below the threshold value during the side edge detection drive, the detection processing unit 74 obtains the position of the side edge SE1 from the count value of the CR counter 75 at that time. Then, the detection processing unit 74 sends the obtained position data of the first side end SE1 to the print control unit 71.

  The print control unit 71 executes print processing based on the position data of the side end SE1. The position data of the side end SE1 is used to determine the actual print start position at which the print head 23 starts to eject ink in the scanning direction X. For example, when margins having a predetermined width are set on both sides in the width direction of the paper P, the print control unit 71 determines a print start position at which the set margin is secured from the position data of the side edge SE1. Further, when the ink is ejected from the paper P by the print head 23, the support base 60 is stained with ink. For this reason, the print control unit 71 specifies a part of the print data that will protrude outside the paper P based on the position data of the side edge SE1, and masks at least a part of the protruded part in an unprintable state. A mask process is performed. By this masking process, the contamination of the support table 60 due to the ink ejection to the outside of the paper P is reduced.

  In FIG. 6, the print control unit 71, the setting unit 72, the overlay calculation unit 73, and the detection processing unit 74 are constructed in the computer 40 by executing the edge detection control program shown in FIGS. Functional part. These functional parts may be configured by software, may be configured by cooperation of software and hardware, or may be configured by hardware.

  Next, a method for driving the carriage 22 when the side edge position of the paper P is detected by the first method will be briefly described with reference to FIGS. Here, FIG. 7 shows the side edge detection drive when the paper is “undefined”, and FIG. 8 shows the side edge detection drive when the paper is not “undefined”. First, the side edge detection drive when the paper is “undefined” will be described.

  As shown in FIG. 7A, the detection preparation scanning in which the carriage 22 is moved from the home position HP to the width center position xc (detection start position) where the sheet width sensor 56 faces the center position in the width direction of the sheet P is performed on the sheet. It ends in the middle of the feeding operation of P. That is, the carriage 22 arrives at the width center position xc before the completion of the sheet P feeding operation.

  Then, the carriage 22 stopped at the detection start position xc starts moving from the detection start position xc as shown in FIG. 7B before the paper P feeding operation is completed, and then the paper width sensor. 56 passes through a position facing the side edge SE1 of the paper P in the stopped state after the feeding operation is completed. That is, the side edge detection drive for moving the carriage 22 from the detection start position x0 on the paper P shown in FIG. 8B to the detection limit position xe located in the region outside the side edge SE1 of the paper P is performed. Is called. In the process of detecting the side edge, the side edge SE1 of the paper P is detected based on the detection signal of the paper width sensor 56. In this case, since the side edge SE1 is present between the width center position xc and the detection limit position xe in any size paper P, the side edge SE1 is necessarily detected by the paper width sensor 56.

  For example, when one of the feeding cassettes 16 and 17 is mounted after being removed by the user, there is a possibility that it has been replaced with a paper P different from the paper size so far. In addition, when an operation of taking out and installing any of the feeding cassettes 16 and 17 is detected, the user is requested to input printing medium information including the paper size of the paper P stored in the feeding cassette. A prompt message is displayed on the display unit 14. The printer 11 has a function for the user to input print medium information including a paper size corresponding to one of the feeding cassettes 16 and 17 by operating the operation unit 15. Since there is a possibility that the user makes a mistake in the paper size input setting or sets the paper P in the paper feeding cassettes 16 and 17 with the wrong size, the first paper P to be fed after detecting such an operation is “Undetermined”. Even in such an “undefined” case, the side edge SE1 of the paper P can be reliably detected. Further, when the paper width sensor 56 detects the side edge SE1 of the paper P, the paper P is in a stopped state, so that the position detection accuracy of the side edge SE1 is increased by the paper width sensor 56.

  Next, with reference to FIG. 8, the side edge detection drive when the paper is not “undefined” will be described. As shown in FIG. 8A, the detection preparation scan for moving the carriage 22 from the home position HP to the detection start position x0 ends during the paper P feeding operation. That is, the carriage 22 arrives at the detection start position x0 before the paper P feeding operation is completed.

  Then, as shown in FIG. 8B, the side edge detection drive for moving the carriage 22 from the detection start position x0 on the paper P to the detection end position x1 located in an area outside the side edge SE1 of the paper P. Is done. In the process of detecting the side edge, the side edge SE1 of the paper P is detected based on the detection signal of the paper width sensor 56. At this time, the carriage 22 stopped at the detection start position x0 by the detection preparation scan starts to move from the detection start position x0 before the paper P feeding operation is completed. Thereafter, immediately before the paper width sensor 56 reaches a position facing the side edge SE1 of the paper P, the feeding operation is completed and the paper P stops. Therefore, the paper width sensor 56 detects the side edge SE1 for the paper P in the stopped state. When the paper width sensor 56 detects the side edge SE1, since the paper P is in a stopped state, the position detection accuracy of the side edge SE1 is increased by the paper width sensor 56.

  Further, as shown in FIG. 8C, the acceleration start position p0 of the first pass of the carriage 22 is more in the traveling direction side of the carriage 22 during the side end detection driving than the detection end position x1 determined from the paper size information. (X1> p0), the side edge detection driving is performed in which the carriage 22 moves from the detection start position x0 to the acceleration start position p0 (detection end position x1 after change). In this case, the carriage 22 can start scanning for the first pass printing from the acceleration start position p0 that has been stopped after the side edge detection drive.

  In the example of FIG. 8D, the speed V1 is higher than the first required time T1 when the distance from the initial detection start position x0 to the detection end position x1 (or p0) is moved at the speed V1 corresponding to this distance. The second required time T2 for moving the shortest movement distance at the speed V2 from the detection start position x3 that can secure the shortest movement distance that can be driven at the higher speed V2 becomes shorter. In this case, the setting is changed from the detection start position x0 determined from the paper size information to the detection start position x3. Then, as shown in FIG. 8A, detection preparation scanning is performed in which the carriage 22 is moved from the home position HP to the detection start position x3. The detection preparation scan ends during the feeding operation of the paper P. That is, the carriage 22 arrives at the detection start position x3 before the paper P feeding operation is completed.

  Then, as shown in FIG. 8D, the carriage 22 that has stopped after the detection preparation scan has started moving from its detection start position x0 (= x3) before the completion of the feeding operation of the paper P, and the speed It moves toward the detection end position x1 (= p0) at a speed V2 that is faster than V1. In the process of detecting the side edge, the side edge SE1 of the paper P is detected based on the detection signal of the paper width sensor 56. At this time, immediately before the paper width sensor 56 reaches the position facing the side edge SE1 of the paper P, the feeding operation is completed and the paper P stops. Therefore, the paper width sensor 56 detects the side edge SE1 for the paper P in the stopped state. When the paper width sensor 56 detects the side edge SE1, since the paper P is in a stopped state, the position detection accuracy of the side edge SE1 is increased by the paper width sensor 56. In the example of FIG. 8D in which the setting is changed from the detection start position x0 determined from the paper size information to the detection start position x3, the first required time T1 when the movement is started from the detection start position x0 before the change is made. It can move to the detection end position x1 in a short second required time T2 (<T1). 8B and 8C show a case where the two required times T1 and T2 satisfy T1 ≦ T2 and the initial detection start position x0 is maintained.

  Then, as shown in FIGS. 8B to 8D, the carriage 22 that has stopped after the side edge detection driving is positioned at the acceleration start position p0 (= x1). Therefore, for example, in the example of FIGS. 8C and 8D, as shown in FIG. 8E, the carriage 22 starts moving to the plus side in the scanning direction from the stopped acceleration start position p0, and the paper P Is printed. For this reason, the waiting time from the completion of the feeding of the paper P to the start of the first pass printing is relatively short for the side edge detection driving for the paper P before the start of printing. .

  Next, with reference to FIG. 9 and FIG. 10, the side end detection drive that is performed as a coping process when the side end detection fails during the side end detection drive will be described. First, with reference to FIG. 9, a description will be given of side edge detection driving that is performed when the side edge detection fails because the actual paper width is narrower than the width assumed from the paper size information.

  As indicated by a solid line in FIG. 9A, when the carriage 22 reaches the initial detection start position x0, the sheet P is not detected (non-detection state), and the detection of the side edge fails. 22 is moved from the initial detection start position x0 to the width center position xc. At this time, the carriage 22 is directly moved from the detection start position x0 to the width center position xc without moving toward the original detection end position x1. Next, as shown in FIG. 9B, side edge detection driving is performed to move the carriage 22 from the width center position xc to the detection end position x1 (= p0). By this side edge detection drive, the side edge SE1 of the paper P is detected at a position before the initial detection start position x0 while the carriage 22 is moving. In the side edge detection drive in FIG. 9B, the carriage 22 may be moved to the detection limit position xe, or may be moved to the initial detection start position x0 (where x0 ≦ p0).

Next, with reference to FIG. 10, a description will be given of the side edge detection driving that is performed when the side edge detection fails because the actual width of the paper P is wider than the width assumed from the paper size information.
As shown in FIG. 10A, when the width of the paper P is wider than expected, when the side edge detection driving for moving the carriage 22 from the detection start position x0 indicated by the solid line to the detection end position x1 is performed. The detection state of the paper P by the paper width sensor 56 continues throughout the entire movement section of the carriage 22. As a result, the side end SE1 is not detected. In this case, the detection limit position xe on the extension of the traveling direction (minus direction of the scanning direction X) of the carriage 22 at the time of the side edge detection driving from the initial detection end position x1 is reset to the detection end position. Therefore, as shown in FIG. 10B, the initial detection end position x1 is set to the detection start position x0, and the side edge detection drive for moving the carriage 22 from the detection start position x0 to the detection limit position xe is performed. . In this case, the carriage 22 may be temporarily stopped at the initial detection end position x1, but if the side end SE1 is not detected, the carriage 22 continues to move even if it reaches the initial detection end position x1. It is preferable to adopt a method of changing the detection end position x1 to the detection limit position xe during the movement and moving the detection end position x1 to the detection limit position xe.

Next, the operation of the printer 11 will be described.
Paper edge detection control performed in the printer 11 when the computer 40 executes the edge detection control program shown in the flowcharts of FIGS. 11 and 12 will be described. When the computer 40 receives the print job data PD and receives a print execution command based on the command in the print job data PD, the computer 40 starts printing by the printer 11. The computer 40 acquires necessary information such as the print mode and the paper size based on the print condition data in the print job data PD. The computer 40 selects one speed control data corresponding to the moving distance from the speed control data VD of the carriage 22 corresponding to the acquired printing mode.

  Here, the sensor 51, 52 detects whether the feeding cassette 16 or 17 is removed and mounted, or the detection state of the sensor 53 is switched from a paper-out state to a paper-out state, and the user replaces the paper P. If there is a possibility, the paper type and paper size of the paper P may be different from those previously set. As described above, when the information regarding the paper P is “indefinite” which may be different from the setting, the computer 40 sets the paper flag to “1” indicating that it is indefinite. On the other hand, when the information regarding the paper P in the feeding cassettes 16 and 17 is as set from the result of the past side edge detection drive, the paper flag is “0”. For example, when the paper flag is “1”, the paper side edge detection drive is performed, and the side edge position detected at that time is assumed based on the paper information (assumed side edge position) and error range. If they match, the paper information at that time is recognized as correct, and the paper information is stored in the nonvolatile memory 43 thereafter. On the other hand, if the detected position of the side edge does not coincide with the estimated side edge position (assumed side edge position) based on the paper size information within the error range, the sheet defined from the detected side edge position The size is stored in a predetermined area in the nonvolatile memory 43. The computer 40 executes paper edge detection control according to the flowcharts shown in FIGS.

  First, in step S11, it is determined whether or not it is indefinite. In this example, it is determined whether or not the paper flag is “1” indicating that the paper flag is indefinite. If it is “1” indicating that the paper flag is indefinite, the process proceeds to step S12, and if it is not indefinite (if the paper flag is “0”), the process proceeds to step S16.

  In step S12, the carriage 22 is moved from the home position HP to the plus side in the scanning direction X and disposed at the width center position xc. That is, the computer 40 drives the carriage motor 36 to move the carriage 22 from the home position HP to the plus side in the scanning direction X and stop it at the width center position xc as shown in FIG.

  In step S13, cueing for transporting the paper P to the print start position is performed. In the present embodiment, both the operation timings of the sheet feeding operation and the movement operation of the carriage 22 to the detection start position x0 are partially overlapped by the ASF / CR overlay control. Before the paper P is completely positioned to the print start position, the carriage 22 is disposed at the width center position xc.

  In step S14, side edge detection driving for moving the carriage to the detection limit position is performed. That is, the carriage 22 is moved from the width center position xc (detection start position) to the detection limit position xe (detection end position) while detecting the side edge by the paper width sensor 56. In this example, the movement of the carriage 22 from the width center position xc is started before the cueing is completed. Then, after the paper P is cued and stopped at the printing start position, the paper width sensor 56 passes the side edge of the paper P in the scanning direction X.

  At this time, as shown in FIG. 7B, since the carriage 22 is moved from the width center position xc to the minus side in the scanning direction X to the detection limit position xe, it is limited to the sheet P having a size assumed from the sheet size information. In other words, the side edge SE1 can be detected for any size paper P including paper Ps whose width in the scanning direction X is smaller than its assumed size and paper P1 which is large.

  In step S15, it is determined whether the side edge has been detected. When the side end can be detected (in the case of affirmative determination), the routine ends. On the other hand, if the side end cannot be detected (in the case of negative determination), the process proceeds to step S26.

  In step S26, error processing is performed. For example, when a paper jam or the like occurs in the paper feeding process and there is no paper, or the paper width sensor 56 is stained with ink or paper dust, the side edge is not detected. In this case, the computer 40 displays an error message on the display unit 14. For example, a message indicating a paper jam error or a sensor detection error is displayed.

Next, processing when the paper is not indefinite will be described.
In step S16, a detection start position x0 and a detection end position x1 are set. The setting process of the positions x0 and x1 is performed by the computer 40 executing a setting routine shown in the flowchart of FIG. Details of the setting routine that is performed first when the paper is not indefinite will be described with reference to FIG.

First, in step S31, a detection start position x0 and a detection end position x1 are set from the paper size information.
In step S32, the maximum carriage speed V1 that can be driven within the number of steps (x0-x1) is selected. Specifically, the computer 40 refers to the data of the speed profile group in which the maximum speed of the carriage 22 and the shortest movement distance (number of steps) necessary for driving at the maximum speed are associated with each other from the nonvolatile memory 43. Thus, the maximum carriage speed V1 that can be driven with a moving distance within the number of steps (x0-x1) is selected.

  In step S33, a first required time T1 for calculating the number of steps (x0−x1) at the speed V1 is calculated. That is, the computer 40 calculates the sum of the acceleration time Ta1, the deceleration time Td1, and the constant speed time Tc1 in the speed profile corresponding to the speed V1 (T1 = Ta1 + Td1 + Tc1). Here, the constant speed time Tc1 is given by Tc1 = ((x0−x1) −Sa1−Sd1) / V1 using the acceleration distance Sa1 and the deceleration distance Sd1.

  In step S34, the print start position p1 is acquired from the print data. The print start position p1 is a position where the print head 23 starts to eject ink while the carriage 22 that has finished the side edge detection drive of the paper P is moving for the first pass scanning.

  In step S35, the acceleration start position p0 is acquired from the print start position p1 (p0 = p1-Snp). Here, Snp is the number of steps corresponding to the moving distance of the carriage 22 from the acceleration start position p0 to the print start position p1 (see FIG. 4). Snp is a value obtained by subtracting the number of steps Sap at which printing during acceleration is performed from the acceleration distance Sa2 (Snp = Sa2-Sap).

  In step S36, it is determined whether or not the acceleration start position p0 is positioned closer to the carriage traveling direction than the detection end position x1 during the side edge detection driving (whether p0 <x1 is satisfied). If p0 <x1 is established, the process proceeds to step S37, and if p0 <x1 is not established, the routine is terminated. When this routine is finished, the detection start position x0 and the detection end position x1 set in step S31 are adopted.

  In step S37, the acceleration start position p0 of the carriage is set to the detection end position x1 (x1 = p0). That is, the initial detection end position x1 is extended to the acceleration start position p0 in the carriage traveling direction during the side edge detection drive.

  In the next step S38, a carriage speed V2 higher than the carriage speed V1 and a minimum drive step number SB of the speed V2 are selected. That is, the computer 40 refers to the data of the speed profile group and acquires the minimum drive step number SB corresponding to the minimum movement distance associated with the maximum speed V2.

  In the next step S39, a second required time T2 for calculating the minimum driving step number SB at the speed V2 is calculated. That is, the computer 40 calculates the sum of the acceleration time Ta3 and the deceleration time Td3 acquired with reference to the speed profile data corresponding to the speed V2 (T2 = Ta3 + Td3).

  In step S40, it is determined whether or not the second required time T2 is shorter than the first required time T1 (whether T1> T2 is satisfied). If T1> T2 is satisfied, the process proceeds to step S41. If T1> T2 is not satisfied, the routine is ended. When this routine is ended, the detection start position x0 set in step S31 and the detection end position x1 (= p0) set in step S37 are adopted.

  In step S41, the carriage speed V2 and the detection start position x0 = p0 + SB are reset. That is, the computer 40 changes the carriage speed during the side edge detection drive from the speed V1 to the speed V2, and changes the detection start position x0 set so far to the detection start position (p0 + SB) or (x0 + SB). .

  Thus, when the detection start position and the detection end position are set by the execution of the program shown in FIG. 12 by the computer 40 (when the processing of S16 in FIG. 11 is completed), the processing from step S17 onward in FIG. 11 is performed.

  In step S17 shown in FIG. 11, the carriage 22 is moved from the home position HP to the plus side in the scanning direction X and arranged at the detection start position x0. That is, the computer 40 drives the carriage motor 36 to move the carriage 22 from the home position HP to the plus side in the scanning direction X and stop it at the detection start position x0 as shown in FIG. The detection start position at this time is a position at a predetermined distance on the plus side in the scanning direction X from the side end position determined from the assumed paper size (detection start position x0 in FIG. 8A), and FIG. There is a detection start position x0 set at a position x3 on the plus side in the scanning direction X from the detection start position x0.

In step S18, cueing is performed for transporting the paper P to the print start position.
In step S19, side edge detection driving is performed to move the carriage to the detection end position x1 at a set speed. That is, side edge detection driving is performed to move the carriage 22 from the detection start position x0 toward the minus side in the scanning direction X to the detection end position x1 while detecting the side edge by the paper width sensor 56.

  In step S20, it is determined whether or not the side edge has been detected. When the side end is detected (in the case of an affirmative determination), the routine ends. On the other hand, when the side end is not detected (in the case of negative determination), the process proceeds to step S21. Here, when the width of the sheet P is narrower than the assumed width (see FIG. 9), the sheet P is not detected at the stage of the detection start position x0 in the side edge detection drive of step S19, and therefore the stage of the detection start position x0. It can be seen that the side edge cannot be detected. On the other hand, when the width of the paper P is wider than the assumed width (see FIG. 10), the paper P is spread over the entire movement section from the detection start position x0 to the detection end position x1 in the side edge detection drive in step S19. It can be seen that the side edges cannot be detected when detected.

  In step S21, it is determined whether or not the sheet has been detected. If the paper P can be detected, the process proceeds to step S24. If the paper P cannot be detected, the process proceeds to step S22. If the width of the paper P is narrower than the expected width (see FIG. 9), the paper cannot be detected, and the process proceeds to step S22. On the other hand, if the width of the paper P is wider than the assumed width (see FIG. 10), the paper can be detected, and the process proceeds to step S24.

  In step S22, the carriage 22 is moved to the width center position xc. In other words, if the sheet cannot be detected in step S21, the actual sheet width is narrower than the sheet width determined from the sheet size information, and the side edge SE1 to be detected is in the scanning direction X from the initial detection start position x0. Will be on the plus side of Therefore, the carriage 22 is once moved to the width center position xc. At this time, the width center position xc is reset to a new detection start position x0 (= xc) after the failure of the side edge detection. In the case of failure due to the actual width of the paper P being narrower than expected, it can be seen that the paper P is not detected at the stage of the detection start position x0 in the side edge detection drive of step S19, so that it is a failure. The side edge detection drive is interrupted when the carriage 22 is at the detection start position x0. For this reason, the carriage 22 moves directly from the detection start position x0 to the width center position xc.

  In step S23, side edge detection driving for moving the carriage 22 to the detection end position x1 is performed. That is, side edge detection driving is performed to move the carriage 22 from the width center position xc toward the minus side in the scanning direction X to the detection end position x1 while detecting the side edge by the paper width sensor 56.

  Therefore, as shown in FIG. 9A, when the detection of the side edge of the paper P fails because the paper P is not detected at the initial detection start position x0, the carriage 22 moves from the initial detection start position x0. The paper of any size moves to the width center position xc, which is the detection start position where the side edge can be detected. Then, as shown in FIG. 9B, side edge detection driving for moving the carriage 22 from the width center position xc to the initial detection end position x1 is performed. During the movement of the carriage 22 in this side edge detection drive, the paper width sensor 56 passes through a position facing the side edge SE1, and the side edge SE1 of the paper P is detected.

  On the other hand, in step S24, side edge detection driving for moving the carriage 22 to the detection limit position xe is performed. That is, while detecting the side edge by the paper width sensor 56, side edge detection driving is performed to move the carriage 22 from the initial detection end position x1 toward the detection limit position xe toward the minus side in the scanning direction X.

  Therefore, as shown in FIG. 10A, when the actual width of the paper P is larger than the width of the paper assumed from the paper size information, the carriage 22 is initially moved from the initial detection start position x0 by the side edge detection drive. The detection state of the paper P continues throughout the entire moving section that moves to the detection end position x1, and the side edge SE1 cannot be detected. In this case, the detection limit position xe positioned on the extension of the traveling direction (minus direction of the scanning direction X) of the carriage 22 at the time of the side edge detection drive than the detection end position x1 at that time is reset as the detection end position. For this reason, as shown in FIG. 10B, side edge detection driving is performed to further move the carriage 22 from the detection start position x0 (= x1) to the detection limit position xe. In this case, for example, even if the carriage 22 reaches the initial detection end position x1, the movement of the carriage 22 continues as it is, and the detection end position x1 is changed to the detection limit position xe during the movement, and the carriage 22 is moved to the detection limit position x1. Move to xe and stop. Then, during the movement of the extended section of the carriage 22, the paper width sensor 56 passes through a position facing the side edge SE1, and the side edge SE1 of the paper P is detected.

  In step S25, it is determined whether or not the side edge has been detected. When the side end can be detected (in the case of affirmative determination), the routine ends. On the other hand, if the side end cannot be detected (in the case of negative determination), the process proceeds to step S26.

  In step S26, error processing is performed. For example, when a paper jam or the like occurs in the paper feeding process and there is no paper, or the paper width sensor 56 is stained with ink or paper dust, the side edge is not detected. In this case, the computer 40 displays an error message on the display unit 14.

According to the embodiment described in detail above, the following effects can be obtained.
(1) The detection start position x0 and the detection end position x1 of the side edge detection drive are set to positions near the side edge across the assumed side edge position based on the paper size information. When the acceleration start position p0 of the carriage 22 for performing the first pass printing obtained from the print data is outside the detection end position x1 (the carriage traveling direction side during the side edge detection drive) (p0 <x1). The acceleration start position p0 of the carriage 22 is set to the detection end position x1. For this reason, acceleration of the carriage 22 for performing the first pass printing can be started from the position (x1 = p0) where the side edge detection driving is stopped and stopped. Therefore, there is no need to move the carriage 22 from the stop position after the side edge detection drive to the acceleration start position p0, so that unnecessary acceleration and deceleration can be omitted. Therefore, the first pass printing can be started immediately after the side edge detection driving is completed.

  (2) The first speed V1 (first speed) in which the carriage 22 determines the first movement distance (x0-x1) from the detection start position x0 (an example of the first detection start position) to the detection end position x1 based on the first movement distance. ) To obtain the first required time T1 required for moving. Further, when the first detection start position x0 is changed to the second detection start position x3 (an example of the second detection start position) that can be set to the second movement distance SB longer than the first movement distance, the carriage 22 performs the second detection. A second required time required to move from the start position to the detection end position at a second speed determined from the second movement distance is obtained. Then, the first required time T1 and the second required time T2 are compared. When the first required time T1 is shorter than the second required time T2 (T1 <T2), the first detection start position x0 is held. On the other hand, when the second required time T2 is shorter than the first required time T1, the first detection start position x0 is changed to the second detection start position x3. Therefore, when the first detection start position x0 is changed to the second detection start position x3, the carriage 22 is required to move from the second detection start position x3 to the detection end position x1 in order to detect the side edge of the paper P. The time required is short. For this reason, after detecting the side edge, printing based on the print data can be started promptly.

  (3) The configuration is such that the detection of the side edge position of the paper P transported (cueed) to the printing start position is performed, and the carriage 22 is detected from the home position HP before the paper P is fed. The movement to the start position x0 is completed. That is, the operation timings of the sheet P feeding operation and the preparation scanning operation for moving the carriage 22 to the detection start position x0 of the side edge detection drive are partially overlapped. For example, if the carriage 22 reaches the detection start position x0 after the paper P feeding operation is finished, the carriage 22 starts moving from the detection start position x0 after the paper P feeding operation is finished. Waiting time occurs. However, in the present embodiment, the detection start position x0 of the carriage 22 has been reached before the completion of the paper P feeding operation, so the detection of the side edge position is quickly started and the next printing is performed relatively early. You can start.

  (4) During the feeding operation in which the paper P is transported to the print start position, the carriage 22 reaches the detection start position x0 and moves from the detection start position x0 before the completion of the paper P feeding operation. And the side end position xe1 is detected during the movement. For this reason, the feeding operation of the paper P and the side edge detection driving of the carriage 22 are performed in a state where a part of the operation timing is overlapped. Therefore, the waiting time from when the fed paper P is stopped until the first pass printing is started by the carriage 22 that has finished detecting the side edge SE1 can be shortened.

  (5) The required time Tp until the carriage 22 reaches the position immediately before the side end position xe1 from the detection start position x0 is estimated, and the remaining transport amount ΔF until the feeding operation ends is a value corresponding to the required time Tp. When ΔFp is reached, the drive of the carriage motor 36 is started, and the movement of the carriage 22 from the detection start position x0 is started. Accordingly, the side edge SE1 can be detected by the paper width sensor 56 under the stopped state of the paper P while partially overlapping the operation timings of the paper P feeding operation and the side edge detection driving. Therefore, the side edge position xe1 of the paper P can be detected with relatively high position detection accuracy, and the first pass printing can be started relatively early after the paper P is fed.

  (6) In the case of feeding the first paper P after the operation to replace the paper at the feeding source is detected and the paper size information is “indefinite” which may be wrong, the carriage 22 is The side edge SE1 of the minimum width paper P is moved to a width center position xc of the detectable paper P (an example of a third detection start position). Then, the movement of the carriage 22 is started from the width center position xc to perform side edge detection driving. Therefore, it is possible to reduce the frequency of failure in which the side edge position is not detected by the side edge detection driving due to the difference between the paper size information and the actual paper size because the paper size information is “undefined”.

  (7) When the sheet P is in the non-detection state at the detection start position and the detection of the side edge position xe1 of the sheet P has failed, the carriage 22 can detect the side edge SE1 of the minimum width sheet in the scanning direction X. Move to the center position xc (an example of a third detection start position). Then, the movement of the carriage 22 is started from the width center position xc, and the side end position xe1 is detected. Therefore, even if the paper P has an excessively small width that cannot be detected by the movement from the initial detection start position x0, the movement of the carriage 22 is started from the width center position xc to perform the side edge detection driving. The side edge position xe1 of the paper P can be detected.

  (8) While the carriage 22 moves from the detection start position x0 to the detection end position x1, the state in which the paper width sensor 56 continues to detect the paper P continues and the detection of the side edge SE1 of the paper P fails. The end position x1 is changed to a position on the extension in the traveling direction of the carriage 22 during the side edge detection drive. Therefore, even if the paper P has an excessive width that cannot be detected by the movement of the carriage 22 up to the initial detection end position x1, the carriage 22 is changed to a position on the extension of the carriage traveling direction during the side edge detection drive. The side end position xe1 of the paper P can be detected by moving to the detection end position (in this example, the detection limit position xe).

In addition, the said embodiment can also be changed into the following forms.
When the side edge is detected while moving the carriage 22 from the detection start position x0 to the detection end position x1 during the side edge detection drive, the detected side edge position xe1 is compared with the acceleration start position p0, and the detection is performed. If the determined side end position xe1 has passed the acceleration start position p0 (xe1 ≦ p0), the carriage 22 may be stopped at the time of detection. At this time, if the detected side end position xe1 does not pass the acceleration start position p0 (xe1> p0), it is preferable to continue the movement of the carriage 22 and stop the carriage 22 at the acceleration start position p0. . According to this configuration, compared to the configuration in which the carriage 22 is always moved to the detection end position x1, the side edge detection driving is stopped earlier, and the first pass of the carriage 22 is started from the stop position to perform one pass. Eye printing can be started earlier. The above control may be performed in the side edge detection drive (S14) when the paper size information is indefinite and the side edge detection drive (S23, S24) when the side edge detection fails. In these cases, the same effect can be obtained.

  The third detection start position that is changed when the detection of the side edge position fails because the actual width of the paper P is narrower than expected is not limited to the width center position xc of the paper P. A detection start position that can detect the side edge of a standard-size print medium (for example, a standard paper) having a minimum width assumed to be used by the printer 11 is sufficient. For example, the third detection start position may be set at a position on the home position HP side by a predetermined value within a range of 1 to 20 mm from the width center position xc. In addition, the side edge SE1 is detected by the paper width sensor 56 in the process of moving from the detection start position x0 toward the width center position xc in the case of failure, and a predetermined distance (for example, on the plus side in the scanning direction from the detected side edge position xe1). The position of 1 to 20 mm) may be set as the third detection start position. In this case, compared to the configuration in which the carriage 22 is always moved to the width center position xc, when the third detection start position is closer to the home position than the width center position xc, the carriage 22 is moved from the initial detection start position x0 to the third detection position. Since the time required to move to the start position is relatively short, the first pass printing can be started earlier.

  The detection end position that is changed when the detection of the side edge position fails because the paper width is narrower than expected is not limited to the initial detection start position x0. For example, the detection end position may be set to a position on the home position HP side by a predetermined value within a range of 1 to 20 mm from the detection start position x0. Further, the side edge SE1 may be detected by the paper width sensor 56 in the process of moving from the detection start position x0 toward the width center position xc in the case of failure. Further, based on the side end position xe1 detected at this time, the detection start position is reset to a position a predetermined distance on the plus side in the scanning direction from the side end position xe1, and the minus side in the scanning direction from the side end position xe1. Alternatively, the detection end position may be reset to a position at a predetermined distance. However, the detection end position and the acceleration start position are compared, and if the acceleration start position is located closer to the carriage traveling direction during detection driving than the detection end position, the acceleration start position is reset to the detection end position. . In this case, compared to the configuration in which the width center position xc is reset to the detection start position, the movement distance to the detection start position reset in many cases and the movement distance from the reset detection start position to the detection end position are relative. Therefore, the first pass printing can be started earlier.

  The detection end position that is changed when the side edge detection fails because the actual paper width is wider than expected is not limited to the detection limit position xe. A detection end position that can detect the side edge of a standard-size print medium (for example, a standard paper) having the maximum width expected to be used in the printer 11 is sufficient. For example, the detection limit position may be set at a position close to the print area PA by a predetermined value within a range of 1 to 20 mm from the home position HP.

  In the embodiment, the overlay control for partially overlapping the operation timings of the sheet P feeding operation and the side edge detection drive may not be performed. However, it is preferable that the carriage 22 completes the arrival from the home position HP to the detection start position x0 before the paper feeding operation is completed. For example, when the feeding operation of the paper P is completed, a sequence for starting the movement of the carriage 22 from the detection start position x0 may be executed almost simultaneously. The arrival of the carriage 22 that has started to move from the home position HP to the detection start position x0 may be slightly delayed from the time when the paper P feeding operation is completed.

  In the embodiment, the timing at which the operation timings of the side edge detection drive and the feeding operation are partially overlapped is not limited to the timing at which the feeding operation is completed immediately before the paper width sensor 56 reaches the side edge position. For example, the timing at which the paper width sensor 56 detects the side edge SE1 for the paper P during the feeding operation may be used.

In the above-described embodiment, the side edge detection driving may be performed for all pages or every predetermined number of pages instead of the configuration in which the side edge detection driving is performed only for the first page in one print job.
Only the first method of detecting only the first side end position of the carriage on the standby position side of the paper may be employed, or the first and second side end positions of the paper on both sides in the scanning direction of the carriage are detected. Only the second method may be adopted.

  Although the detection start position and the detection end position corresponding to the paper size are set based on the paper size information, the detection start position and the detection end position may be fixed values. Even with such a fixed value, by resetting the acceleration start position p0 to the detection end position x1, the movement of the carriage 22 is started from the end position of the side edge detection drive, and the first pass printing is performed early. Can start. Even with such a fixed value, the time required for the side edge detection drive can be shortened by resetting the detection start position x0 to the detection start position x3 and moving the carriage at the speed V2.

  A sensor for detecting the width of the set paper P is provided in a paper feeding source such as a feeding cassette or a feeding tray, and a detection start position and a detection end position based on the width information detected by the sensor And may be set.

  The printing apparatus is not limited to an ink jet printer as long as it can print on a printing medium such as paper P, and may be a dot impact printer. Further, the printing apparatus is not limited to a multifunction machine, and may be a printer having only a printing function.

  -The print medium is not limited to cut paper, but may be roll paper. The printing medium is not limited to paper, and may be a resin film, a metal foil, a metal film, a resin-metal composite film (laminate film), a woven fabric, a nonwoven fabric, a ceramic sheet, or the like.

  DESCRIPTION OF SYMBOLS 11 ... Printer as an example of printing apparatus, 12 ... Apparatus main body, 14 ... Display part, 15 ... Operation part, 22 ... Carriage, 23 ... Print head, 30 ... Controller as an example of control part, 36 ... Carriage motor, 37 A feeding motor constituting an example of the conveying unit, 38 a conveying motor constituting an example of the conveying unit, 40 a computer constituting an example of the control unit, 43 a non-volatile memory constituting an example of the storage unit, 48, DESCRIPTION OF SYMBOLS 49 ... Feed roller which comprises an example of a conveyance part, 55 ... Paper detection sensor, 56 ... Paper width sensor as an example of a detection part, 57 ... Linear encoder, 58 ... Encoder, 67 ... Conveyance roller which comprises an example of a conveyance part Pair, 68... Discharge roller pair constituting an example of the transport unit, 71... Print control unit, 72... Setting unit, 73. Detection processing unit, 75 ... CR counter, 76 ... PF counter, 77 ... storage unit, 81 ... calculation unit, 82 ... determination unit, P ... paper as an example of print medium, X ... scanning direction (width direction), Y ... Transport direction, HP ... home position as an example of a standby position, SE1 ... side edge as an example of an end, x0 ... detection start position as an example of a first detection start position, x1 ... detection end position, x3 ... second Detection start position as an example of detection start position, xe ... detection limit position, xe1 ... side end position, V1 ... carriage speed as an example of first speed, V2 ... carriage speed as an example of second speed, SB ... th 2 Shortest travel distance (minimum number of drive steps) as an example of travel distance, VD: speed control data, T1: first required time, T2: second required time, Tp: required time.

Claims (9)

A printing device,
A carriage that scans in a scanning direction that intersects the transport direction of the print medium, and includes a print head that performs printing on the print medium, and a detection unit that detects an end portion in a direction that intersects the transport direction of the print medium;
A transport unit that transports the print medium to an area in which the carriage is scanned;
A control unit for controlling the printing apparatus;
Have
The controller is
Detecting the edge from the detection start position inside the edge position of the print medium toward the detection end position outside,
When the acceleration start position of the carriage for performing printing based on print data on the print medium after executing the detection of the edge is outside the detection end position, the acceleration start position of the carriage is A printing apparatus, characterized by being set to a detection end position. The longer the moving distance of the carriage, the higher the speed of the carriage.
When the detection start position is the first detection start position, the carriage moves at a first speed determined from the first movement distance at a first movement distance between the first detection start position and the detection end position. When the first required time required and the first detection start position are changed to a second detection start position that is a second movement distance longer than the first movement distance, the carriage is moved from the second detection start position to the first detection time. The second required time required to move to the detection end position at a second speed determined from two moving distances is compared, and if the first required time is shorter than the second required time, the detection start position Is held at the first detection start position, and when the second required time is shorter than the first required time, the detection start position is changed from the first detection start position to the second detection start position. That features The printing apparatus according to claim 1. Before the carriage moves to the detection start position, the carriage is disposed at a standby position outside the print medium in the scanning direction,
The control unit is configured to detect the edge of the print medium conveyed to a print start position;
3. The printing apparatus according to claim 1, wherein movement of the carriage to the detection start position is started before the print medium is transported to the print start position and stopped. 4. The control unit causes the carriage to reach the detection start position while the print medium is being transported to the print start position.
4. The movement of the carriage from the detection start position is started before the print medium has been transported to the print start position, and the end portion is detected during the movement of the carriage. 5. The printing apparatus as described.   The controller estimates a time required for the carriage to move from the detection start position to the end position, and when the carriage reaches the end position, the print medium stops at the print start position. 5. The printing apparatus according to claim 4, wherein movement of the carriage from the detection start position is started at a timing when the printing medium is in a stopped state, and the end portion of the print medium in a stopped state is detected. .   A third detection start position at which the control unit can detect an end portion of the print medium having a minimum width in the scanning direction when the information on the print medium is indefinite. 6. The printing apparatus according to claim 1, wherein the end of the carriage is detected by starting movement of the carriage from the third detection start position.   When the print medium is in a non-detection state at the detection start position and fails to detect the end of the print medium, the control unit moves the carriage to a print medium having a minimum width in the scanning direction. The end portion is moved to a detectable third detection start position, and the carriage is moved from the third detection start position to detect the end portion. The printing apparatus according to one item.   The control unit has failed to detect the edge of the print medium because the detection unit continues to detect the print medium while the carriage moves from the detection start position to the detection end position. 8. The printing apparatus according to claim 1, wherein the detection end position is changed to a position on an extension in a traveling direction of the carriage when the end portion is detected. .   The control unit stops the movement of the carriage when the end is detected if the end position where the detection unit detects the end is past the acceleration start position. 9. The movement of the carriage is stopped after waiting for the carriage to reach the acceleration start position if the part position does not pass the acceleration start position. The printing apparatus according to item.