JP2014028440A - Printing apparatus and printing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce, in printing on a continuous sheet having a splice portion, a change between print positions in portions preceding and succeeding the splice portion.SOLUTION: A splice portion in a sheet is detected, and a position in a width direction of the sheet is corrected before printing is performed on a portion succeeding the splice portion.

Description

  The present invention relates to a printing technique for printing on a continuous sheet having a splice portion.

  A roll-like continuous sheet is used for a large amount of prints such as lab prints. When manufacturing this roll-shaped continuous sheet, from the viewpoint of improving the manufacturing yield, the ends of a plurality of continuous sheets that are less than the required length are joined together with a fixing material (hereinafter referred to as a tape) such as a splicing tape. In some cases, the roll has a required length. Such a roll-like continuous sheet has one or more splice parts (joining parts) joined by tape at random positions.

  In the apparatus disclosed in Patent Document 1, the position of the splice part is detected by detecting the tape using an optical sensor, and the area including the splice part is controlled as a non-printable area.

  When a continuous sheet is used, another continuous sheet may be coupled to the trailing edge of the printed or printed continuous sheet to continue the printing operation. Similar control is required for the splice portion formed in this case.

JP 2001-239715 A

  In such a splice unit, there are cases where the subsequent sheets are connected in a state shifted in the width direction (direction intersecting the conveyance direction) or connected obliquely with respect to the traveling direction. Further, there is a possibility that a succeeding sheet having a width different from that of the preceding sheet may be connected. In such a case, since the position where printing is performed is shifted with respect to the sheet, the amount of margin or the amount of protrusion of the printed result differs before and after the splice portion. If the print position changes in the middle of a plurality of pages of a single printed matter such as a photo album, the viewer feels uncomfortable. Therefore, it is desired that a series of images sequentially printed on a continuous sheet maintain the same print position. Patent Document 1 does not disclose any technique for recognizing and solving such problems.

  Accordingly, an object of the present invention is to reduce a change in print position before and after a splice portion in printing on a continuous sheet having a splice portion.

  Therefore, the printing apparatus of the present invention is a printing apparatus capable of performing printing on a sheet including a price portion in which a preceding sheet and a succeeding sheet following the preceding sheet are connected. A print unit to be performed, and a detection unit that detects the splice unit. When the detection unit detects the splice unit, the print unit adjusts the print position before starting printing on the succeeding sheet. It is characterized by performing.

  According to the present invention, when the splice portion is detected, the print position is adjusted before printing is performed on subsequent sheets after the splice portion. As a result, in printing on a continuous sheet having a splice portion, it is possible to reduce the change in the print position before and after the splice portion.

FIG. 2 is a schematic cross-sectional view illustrating an internal configuration of the printing apparatus. It is a block diagram which shows the concept of a control part. (A)-(d) is the figure which showed the splice part of the continuous sheet. (A), (b) is the schematic which showed the cross section from the side of a printing apparatus. (A) to (c) is a configuration diagram showing the internal configuration of the print unit. 6 is a flowchart illustrating an entire sequence of a printing operation. 10 is a flowchart illustrating a sequence of a printing operation according to a fifth embodiment. FIG. 3 is a diagram illustrating an internal configuration of a print unit. 6 is a flowchart illustrating an entire sequence of a printing operation.

(First embodiment)
Hereinafter, an embodiment of a printing apparatus using an inkjet system according to a first embodiment of the present invention will be described with reference to the drawings. The printing apparatus according to the present embodiment uses a long and continuous sheet (a continuous sheet longer than the length of a repeated print unit (referred to as one page or unit image) in the conveyance direction), and is used for both simplex printing and duplex printing. It is a compatible high-speed line printer. For example, it is suitable for the field of printing a large number of sheets in a print laboratory or the like.

  FIG. 1 is a schematic cross-sectional view showing the internal configuration of the printing apparatus. The printing apparatus according to the present embodiment is capable of duplex printing on the first surface of the sheet and the second surface on the back side of the first surface, using the sheet wound in a roll shape. The printing apparatus includes a sheet supply unit 1, a paste unit 33, a buffer unit 34, a decurling unit 2, a printing unit 4, an inspection unit 5, a cutter unit 6, an information recording unit 7, a drying unit 8, a reversing unit 9, and a discharge conveyance unit 10. , A sorter unit 11, a discharge unit 12, and a control unit 13. The discharge unit 12 refers to a unit that includes the sorter unit 11 and performs discharge processing. A sheet is conveyed by a conveyance mechanism including a roller pair and a belt along a sheet conveyance path indicated by a solid line in the drawing, and is processed in each unit. Note that at an arbitrary position in the sheet conveyance path, the side close to the sheet supply unit 1 is referred to as “upstream”, and the opposite side is referred to as “downstream”.

  The sheet supply unit 1 is a unit for holding and supplying a continuous sheet wound in a roll shape. The sheet supply unit 1 can store two rolls R <b> 1 and R <b> 2, and is configured to selectively pull out and supply a sheet. The number of rolls that can be stored is not limited to two, and one or three or more rolls may be stored. Moreover, if it is a continuous sheet | seat, it will not be restricted to what was wound by roll shape. For example, the continuous sheet | seat provided with the perforation for every unit length may be return | folded and laminated | stacked for every perforation, and may be accommodated in the sheet | seat supply part 1. FIG.

  The continuous sheet used here has one or more splice parts (joining parts) joined by tape or glue at random positions. The splice portion is an inappropriate area that is not suitable for image printing. A detection unit 31 that detects a splice unit is provided in the vicinity of the outlet of the sheet supply unit 1, and detects a splice unit of a continuous sheet supplied from the sheet supply unit 1. Details of the detection unit 31 will be described later.

  The decurling unit 2 is a unit that reduces curling (warping) of the sheet supplied from the sheet supply unit 1. The decurling unit 2 uses two pinch rollers for one driving roller, and curls the sheet by curving and passing the sheet so as to give the curl in the opposite direction, thereby reducing the curl.

  The print unit 4 is a sheet processing unit that forms an image by performing a print process on the conveyed sheet from above with the print head unit 14. That is, the print unit 4 is a processing unit that performs a predetermined process on the sheet. The printing unit 4 also includes a plurality of pairs of conveyance rollers 41 and 42 that convey the sheet. The print head unit 14 includes a line type print head in which an inkjet nozzle row is formed in a range that covers the maximum width of a sheet that is assumed to be used. In the print head unit 14, a plurality of print heads are arranged in parallel along the transport direction. In this embodiment, there are three print heads corresponding to three colors of C (cyan), M (magenta), and Y (yellow). The number of colors and the number of print heads are not limited to three. As the inkjet method, a method using a heating element, a method using a piezo element, a method using an electrostatic element, a method using a MEMS element, or the like can be adopted. The ink of each color is supplied from the ink tank to the print head unit 14 via the ink tube.

  The inspection unit 5 optically reads the inspection pattern or image printed on the sheet by the printing unit 4 using a scanner, and inspects the nozzle state of the print head, the sheet conveyance state, the image position, etc., and the image is printed correctly. This is a unit for determining whether or not. The scanner has a CCD image sensor and a CMOS image sensor.

  The cutter unit 6 is a unit including a mechanical cutter 18 that cuts a printed sheet into a predetermined length. The cutter unit 6 further includes a cut mark sensor for optically detecting a cut mark recorded on the sheet and a plurality of conveying rollers for sending the sheet to the next process. A trash can 19 is provided in the vicinity of the cutter unit 6. The trash box 19 accommodates small sheet pieces that are cut off by the cutter unit 6 and discharged as trash. The cutter unit 6 is provided with a sorting mechanism for discharging the cut sheet to the trash box 19 or shifting it to the original conveyance path.

  The information recording unit 7 is a unit that records print information (unique information) such as a print serial number and date in a non-print area of the cut sheet. Recording is performed by printing characters and codes using an inkjet method, a thermal transfer method, or the like. A sensor 21 that detects the leading edge of the cut sheet is provided on the upstream side of the information recording unit 7 and the downstream side of the cutter unit 6. Based on the detection timing of the sensor 21, the timing at which information is recorded by the information recording unit 7 is controlled.

  The drying unit 8 is a unit for heating the sheet printed by the printing unit 4 and drying the applied ink in a short time. Inside the drying unit 8, hot air is applied at least from the lower surface side to the passing sheet to dry the ink application surface. The drying method is not limited to the method of applying hot air, and may be a method of irradiating the sheet surface with electromagnetic waves (such as ultraviolet rays and infrared rays).

  The sheet conveyance path from the sheet supply unit 1 to the drying unit 8 is referred to as a first path. The first path has a U-turn shape between the printing unit 4 and the drying unit 8, and the cutter unit 6 is located in the middle of the U-turn shape.

  The reversing unit 9 is a unit for temporarily winding a continuous sheet on which front surface printing has been completed when performing double-sided printing, and reversing the front and back. The reversing unit 9 is a path (loop path) (referred to as a second path) from the drying unit 8 through the decurling unit 2 to the printing unit 4 for supplying the sheet that has passed through the drying unit 8 to the printing unit 4 again. It is provided on the way. The reversing unit 9 includes a winding rotary body (drum) that rotates to wind the sheet. The continuous sheet that has been printed on the surface and has not been cut is temporarily wound around the winding rotary member. When the winding is completed, the winding rotary member rotates in the reverse direction, and the wound sheet is fed out in the reverse order to the winding and supplied to the decurling unit 2 and sent to the printing unit 4. Since this sheet is turned upside down, the printing unit 4 can print on the back side. If the sheet supply unit 1 is a first sheet supply unit, the reversing unit 9 can be regarded as a second sheet supply unit. More specific operation of duplex printing will be described later.

  The discharge conveyance unit 10 is a unit for conveying the sheet cut by the cutter unit 6 and dried by the drying unit 8 and delivering the sheet to the sorter unit 11. The discharge conveyance unit 10 is provided in a route (referred to as a third route) different from the second route in which the reversing unit 9 is provided. A path having a movable flapper at a branch position (hereinafter referred to as a discharge branch position) of the path in order to selectively guide the sheet conveyed on the first path to one of the second path and the third path. A switching mechanism is provided.

  The discharge unit 12 including the sorter unit 11 is provided on the side of the sheet supply unit 1 and at the end of the third path. The sorter unit 11 is a unit for sorting printed sheets for each group as necessary. The sorted sheets are discharged to a plurality of trays that the discharge unit 12 has. In this way, the third path has a layout that passes below the sheet supply unit 1 and discharges the sheet to the opposite side of the printing unit 4 and the drying unit 8 across the sheet supply unit 1.

  As described above, the sheet supply unit 1 to the drying unit 8 are sequentially provided in the first path. The tip of the drying unit 8 is branched into a second route and a third route, and the reversing unit 9 is provided in the middle of the second route, and the tip of the reversing unit 9 joins the first route. A discharge part 12 is provided at the end of the third path.

  The control unit 13 is a unit that controls each unit of the entire printing apparatus. The control unit 13 includes a CPU, a storage device, a controller including various control units, an external interface, and an operation unit 15 that is input and output by a user. The operation of the printing apparatus is controlled based on a command from a host device 16 such as a controller or a host computer connected to the controller via an external interface.

  FIG. 2 is a block diagram illustrating the concept of the control unit 13. A controller (range enclosed by a broken line) included in the control unit 13 includes a CPU 201, a ROM 202, a RAM 203, an HDD 204, an image processing unit 207, an engine control unit 208, and an individual unit control unit 209. A CPU 201 (central processing unit) controls the operation of each unit of the printing apparatus in an integrated manner. The ROM 202 stores programs to be executed by the CPU 201 and fixed data necessary for various operations of the printing apparatus. The RAM 203 is used as a work area for the CPU 201, used as a temporary storage area for various received data, and stores various setting data. The HDD 204 (hard disk) can store and read programs to be executed by the CPU 201, print data, and setting information necessary for various operations of the printing apparatus. The operation unit 15 is an input / output interface with a user, and includes an input unit such as a hard key and a touch panel, and an output unit such as a display for presenting information and a sound generator.

  For units that require high-speed data processing, a dedicated processing unit is provided. An image processing unit 207 performs image processing of print data handled by the printing apparatus. Converts the color space (for example, YCbCr) of the input image data into a standard RGB color space (for example, sRGB), and performs various image processing such as resolution conversion, image analysis, and image correction on the image data as necessary. Applied. Print data obtained by these image processes is stored in the RAM 203 or the HDD 204. The engine control unit 208 performs drive control of the print head unit 14 of the print unit 4 according to print data based on a control command received from the CPU 201 or the like. The engine control unit 208 also controls the transport mechanism of each unit in the printing apparatus. The individual unit control unit 209 includes a sheet supply unit 1, a decurling unit 2, a paste unit 33, a buffer unit, an inspection unit 5, a cutter unit 6, an information recording unit 7, a drying unit 8, a reversing unit 9, a discharge conveyance unit 10, and a sorter. It is a sub-controller which controls each unit of the unit 11 and the discharge unit 12 individually. The individual unit control unit 209 controls the operation of each unit based on a command from the CPU 201. The external interface 205 is an interface (I / F) for connecting the controller to the host device 16 and is a local I / F or a network I / F. The above components are connected by the system bus 210.

  The host device 16 is a device serving as a supply source of image data for causing the printing apparatus to perform printing. The host device 16 may be a general-purpose or dedicated computer, or a dedicated image device such as an image capture having an image reader unit, a digital camera, or a photo storage. When the host device 16 is a computer, an OS, application software for generating image data, and a printer driver for the printing device are installed in a storage device included in the computer. Note that it is not essential to implement all of the above processing by software, and a part or all of the processing may be realized by hardware.

  FIGS. 3A to 3D are views showing a splice portion (joint portion) of a continuous sheet used in this embodiment. The continuous sheet used in this embodiment has one or more splice parts (joining parts) joined with tape or glue at random positions. The continuous sheet has a splice portion in advance when the roll is manufactured. In addition, when a continuous sheet of one roll is used up, the leading edge of a new sheet may be connected to the trailing edge of the sheet to continue printing as a continuous sheet. Is formed.

  3A, 3B, and 3C are plan views of the splice portion. In the splice part, it is desirable that the end portions in the width direction of the preceding sheet 26 and the succeeding sheet 27 are connected so as to be in a straight line without being shifted, but they are shifted as shown in (a) or inclined as shown in (b). There is a case. Further, there may be a case where the widths of the sheets are different as in (c), and there are cases where (a), (b), and (c) are connected in a composite state. The present invention makes it possible to maintain a certain positional relationship between the sheet and the image before and after such a splice portion. FIG. 3D is a side view of the splice part, and the tape 25 of the splice part of the continuous sheet can be detected optically in a non-contact manner by the detection part 31 provided on the upper part of the conveyed sheet. .

  4A and 4B are schematic views illustrating a cross section from the side of the printing apparatus according to the present embodiment. The printing apparatus of the present embodiment has a paste unit 33 downstream of the sheet supply unit 1. A buffer unit 34 is provided between the paste unit 33 and the print unit 4. The roll is consumed during printing, and the trailing edge of the preceding sheet 26 stops at the paste portion 33 with a stopper (not shown). At this time, the buffer unit 34 is changed from the state shown in FIG. 4A to the state shown in FIG. 4B, the roller pair of the buffer unit 34 is raised, and the length of the paper path is changed. Continue supplying sheets to part 4. During this time, the next roll is set in the sheet supply unit 1, and the leading end of the succeeding sheet 27 is connected to the trailing end of the preceding sheet 26 stopped by the stopper by the splice tape 25 in the paste unit 33. The sheet is in a cross-sectional state as shown in FIG. The preceding continuous sheet (preceding sheet 26) and the succeeding continuous sheet (following sheet 27) are joined together at a splice portion to form a continuous continuous sheet S. In this example, the preceding sheet 26 and the succeeding sheet 27 are partially overlapped and glued together, and the tape 25 is further stuck thereon. The portion where the tape 25 is affixed is the splice portion. Due to the overlap between the sheets and the thickness of the tape 25, only that portion is thicker than the original sheet thickness, and a large step is formed. In many cases, the tape 25 uses PET as a base material, paper, a nonwoven fabric base material, or the like.

  FIGS. 5A to 5C are configuration diagrams showing the internal configuration of the print unit 4, wherein FIG. 5A is a top view, FIG. 5B is a front view, and FIG. 5C is a main view above the sheet. It is the bottom view which looked at the member from the lower part. The continuous sheet S supplied from the sheet supply unit 1 to the printing unit 4 is conveyed in the direction of arrow A in the printing unit 4 while its width direction position is regulated by the guide means 51. As a sheet conveyance mechanism in the printing unit 4, an upstream-side conveyance roller pair including a conveyance roller 42 and a rotation roller (pinch roller) 41 driven and rotated, and a downstream including a conveyance roller 44 and a conveyance roller (pinch roller) 43 driven and rotated. A pair of conveying rollers on the side is provided. The platen 53 guides and holds the lower surface of the continuous sheet at the printing position. The print unit 4 includes a plurality of ink jet type print heads 45, 46 and 47. Each print head has a line type print head in which an inkjet nozzle row is formed in a range that covers the maximum print width expected to be used. The nozzle array of the print head may be either one in which unit nozzle chips are formed over the entire width direction by a regular arrangement such as a staggered arrangement, or one line formed over the entire width direction. . As the inkjet method, a method using a heating element, a method using a piezo element, a method using an electrostatic element, a method using a MEMS element, or the like can be adopted. Each color ink is supplied from an ink tank to each print head via an ink tube. In the present embodiment, the print head unit 14 includes three parts, a cyan head 45 for cyan ink, a magenta head 46 for magenta ink, and a yellow head 47 for yellow color. As shown in FIG. 5C, the nozzle row 48 is formed on the discharge surface of the cyan head 45, the nozzle row 49 is formed on the discharge surface of the magenta head 46, and the nozzle row 50 is formed on the discharge surface of the yellow head 47. Has been. Note that the number of colors and the number of print heads are not limited to three, and may be larger or smaller. Each print head is connected to an ink tube, and ink is supplied from an ink tank (not shown). Each print head may be a unit integrated with an ink tank that stores the corresponding color ink. Each print head is integrally held by a head holder 40. The head holder 40 can be moved up and down in the direction of arrow B (see FIG. 5B) and moved in the direction of arrow C (see FIG. 5A) by a drive mechanism.

  The inspection unit 5 that performs inspection by reading is located further downstream of the pair of downstream conveyance rollers 43 and 44, and the conveyance amount adjustment image and the inspection image printed on the continuous sheet using the print head unit 14 are displayed. read. As shown in FIG. 5C, the inspection unit 5 includes a light emitting unit including the light emitting elements 20 of RGB three colors and a light receiving unit including the image sensor 52 (CCD image sensor or CMOS image sensor). The white reference plate 24 (see FIG. 5B) is disposed to face the reading position of the image sensor 52 with the sheet interposed therebetween. The white reference plate 24 is formed of a white plate and is used for color calibration of the image sensor 52. A discharge roller pair 23 for discharging continuous sheets is provided downstream of the inspection unit 5 and the white reference plate 24.

  The detection unit 31 that optically detects the splice unit (tape 25) in a non-contact manner includes a light emitting unit that irradiates light obliquely onto the sheet surface and an array sensor that detects reflected light. The preceding sheet 26 and the succeeding sheet 27 are both glossy white and have a high reflectance. On the other hand, the surface of the tape 25 is black and has been subjected to mat processing, and has low light reflectance. Using this difference in reflectance, the detection unit 31 detects that the tape 25 of the splice has passed through the detection position of the sensor. The detection unit 31 can also detect the height of the sheet surface depending on which element of the array sensor having two or more light receiving elements receives the reflected light centrally. Two guide roller pairs 29 are provided with the detection unit 31 sandwiched between the upstream and downstream sides, and the position in the height direction of the sheet at the detection position of the detection unit 31 is stabilized to stabilize the detection accuracy. The guide means 51 has a sensor capable of measuring the end position of the sheet, and can acquire both end positions in the width direction of the sheet.

  FIG. 6 is a flowchart showing the entire sequence of the printing operation controlled by the control unit 6. Hereinafter, processing in the printing operation will be described with reference to this flowchart. In step S101, sequential printing of a plurality of unit images is started on a continuous sheet. In step S102, the splicing part of the continuous sheet is detected by the detecting unit 31 during printing. If the splice part is detected (YES), the process proceeds to step S103. If not detected (NO), the process proceeds to step S108. In step S103, the unit image is continuously printed until the detected splice unit reaches the print position of the most upstream print head 47 of the print head unit 14, and as many unit images as possible are printed. The length of the conveyance path from the detection position of the detection unit 31 to the print position of the most upstream print head 47 is determined by design. Therefore, the number of unit images that can be printed in the area of the length can be calculated from the length of the unit image in the transport direction. In step S104, an area including the splice portion is set as a print prohibition area, and when the print prohibition area passes the print position, printing is skipped without performing printing. Therefore, the print prohibited area is blank without ink.

  In step S105, the shift amount measuring unit 54 measures the shift amount in the width direction (the direction of arrow C in FIG. 5A) following the splice portion. In step S106, the position correction in the width direction, which is a direction intersecting the continuous sheet S conveyance direction of the head holder 40, is performed after the splice portion passes the print position. As described above, the head holder 40 is movable in the width direction. By moving the head holder 40 to an appropriate position based on the result measured in step S105, the print position relative to the sheet width is between the preceding sheet and the succeeding sheet. Since it is kept equal, the user does not feel uncomfortable.

  Thereafter, in step S107, printing of the unit image is resumed after the carry amount adjustment process. In step S108, it is determined whether printing of a predetermined number of unit images has been completed (YES) or not (NO). If the determination is NO, the process returns to step S101 and the process is repeated. If the determination is YES, the sequence ends.

  In this manner, the splice portion is detected, and the position of the head holder 40 in the width direction of the sheet is corrected before printing after the splice portion is started. As a result, it was possible to realize a printing apparatus and a printing apparatus control method capable of reducing a change in print position before and after the splice portion.

(Second Embodiment)
Hereinafter, a second embodiment of the present invention will be described with reference to the drawings. Since the basic configuration of the present embodiment is the same as that of the first embodiment, only the characteristic configuration will be described below.

  In the first embodiment, the adjustment is performed by moving the head holder 40 that can be moved in the width direction in the width direction position adjustment in step S106 in FIG. Adjustment is performed by changing the nozzle used in the head.

  As described above, the printing apparatus according to the present invention is equipped with a line type print head in which an inkjet nozzle array is formed in a range that covers the maximum print width. However, since the nozzles near the end in the nozzle row are located outside the sheet, there are areas that are not used. Therefore, in the present embodiment, by using the nozzles that are not used at the end portions and shifting the nozzle region to be used based on the result measured in step S105 in FIG. To adjust the position in the width direction.

  Thus, before detecting the splice part and printing on the sheet after the splice part, the position of the sheet in the width direction is corrected by shifting the nozzle area to be used. As a result, it was possible to realize a printing apparatus and a printing apparatus control method capable of reducing a change in print position before and after the splice portion.

(Third embodiment)
Hereinafter, a third embodiment of the present invention will be described with reference to the drawings. Since the basic configuration of the present embodiment is the same as that of the first embodiment, only the characteristic configuration will be described below.

  In the print width direction position adjustment performed in step S106 in FIG. 6, in the first embodiment, the adjustment is performed by moving the head holder 40 that is movable in the width direction. In this embodiment, the position is adjusted by moving the sheet in the width direction and changing the positional relationship with the print head. As described above, the printing apparatus according to the present invention is provided with the guide means 51 that regulates the position in the width direction of the sheet in order to stably convey the sheet. Therefore, the guide means 51 is moved based on the result measured in step S105 in FIG. As a result, the position in the width direction of the sheet can be appropriately adjusted with respect to the print head position.

  In this way, the position of the sheet in the width direction is corrected by detecting the splice and adjusting the position by moving the sheet guide means before printing the splice and subsequent parts. As a result, it was possible to realize a printing apparatus and a printing apparatus control method capable of reducing a change in print position before and after the splice portion.

(Fourth embodiment)
The fourth embodiment of the present invention will be described below with reference to the drawings. Since the basic configuration of the present embodiment is the same as that of the first embodiment, only the characteristic configuration will be described below.

  In the first embodiment, the shift amount is measured by the shift amount measuring unit 54 (see FIG. 5) in the measurement of the shift amount in the width direction of the subsequent sheet performed in step S105 in FIG. In the present embodiment, the shift amount is detected by detecting the pressure applied to the guide unit 51 from the sheet side end (pressure measurement).

  The pressure applied from the guide means 51 to the contact surface of the sheet end changes depending on the relative positional relationship between the guide means 51 and the sheet. Therefore, if there is a shift in the succeeding sheet following the splice part, the pressure applied to the guide means 51 changes. The guide means 51 of the present embodiment has a function of measuring this pressure, a function of moving the guide means 51 by the driving means, and a means of measuring the position of the guide means 51 itself.

  After the splice portion passes through the guide means 51, the pressure applied to the guide means 51 is measured, and the guide means 51 is moved to a position where the pressure falls within a predetermined range based on the measurement result. Since the position of the moved guide means 51 indicates the position in the width direction of the sheet, by acquiring this, the shift amount in the width direction of the succeeding sheet can be detected. Then, the print position is adjusted based on the detected deviation amount.

  In this way, the splice portion is detected, the shift in the width direction of the succeeding sheet after the splice portion is detected by the guide means, and the print position is adjusted based on the detected shift amount. As a result, it was possible to realize a printing apparatus and a printing apparatus control method capable of reducing a change in print position before and after the splice portion.

(Fifth embodiment)
Hereinafter, a fifth embodiment of the present invention will be described with reference to the drawings. Since the basic configuration of the present embodiment is the same as that of the first embodiment, only the characteristic configuration will be described below.

  FIG. 7 is a flowchart showing the entire sequence of the printing operation controlled by the control unit 6 in this embodiment. Hereinafter, the print operation process according to the present embodiment will be described with reference to this flowchart.

  Steps S201 to S204 in the present embodiment perform the same processing as steps S101 to S104 described in FIG. Also, in step S205 of this embodiment, the amount of deviation of the subsequent sheet is measured in the same manner as in step S105 of FIG. 6, but in step S205, this measured value is set to Z1. Further, in step S206, the sheet is conveyed by a predetermined amount, and this conveyance amount is set to L. In step S207, the sheet shift amount is measured again, and this measured value is set to Z2. By measuring the deviation amount at two points in this way, the inclination amount D of the succeeding sheet in the splice portion is obtained as D = (Z2−Z1) / L in step S208. This amount of inclination is gradually eliminated as the sheet conveyance progresses. However, the influence is particularly great at the leading edge of the succeeding sheet, and it causes a print position shift as skewing or distortion of the sheet.

  Thereafter, in step S209, when the value of the inclination amount D is larger than the predetermined value X1, in step S214, the downstream conveying roller is once separated from the sheet, and the effect of the preceding sheet is removed by re-nipping. Returning to step S205, the operation is continued. If the absolute value of the tilt amount D is smaller than the predetermined value X1 in step S209, the width direction is the same as in the first to third embodiments according to the sheet displacement amount Z2 in step S210. Perform position adjustment processing. Thereafter, in step S211, the processing from step S205 to step S210 is repeated until the absolute value of the tilt amount D falls below a predetermined value X2 that is smaller than X1. The predetermined value X2 is set in advance to a value equal to or lower than a level at which the sheet inclination does not affect the print result.

  By repeating the above processing, the influence of the sheet inclination on printing is removed, so that the subsequent steps S212 and S213 perform the same processing as steps S107 and S108 in FIG.

  In the present embodiment, the configuration of the apparatus can be the same as that shown in the first to fourth embodiments. It has a wide range of applications.

  As described above, the shift amount is measured at two points on the sheet (multiple measurements are performed), and the operation of once separating the conveyance roller from the sheet and re-niping until the shift amount becomes a predetermined amount or less is repeated. As a result, it was possible to realize a printing apparatus and a printing apparatus control method capable of reducing a change in print position before and after the splice portion.

(Sixth embodiment)
The sixth embodiment of the present invention will be described below. Since the basic configuration of the present embodiment is the same as that of the first embodiment, only the characteristic configuration will be described below.

  When the splice unit is detected using the same configuration of the apparatus as in the third embodiment or the fourth embodiment described above, the guide unit is retracted from the sheet, and after the splice unit passes through the guide unit, an appropriate The guide means is moved to a proper position. According to this method, in addition to the effects of the third and fourth embodiments, when the shift of the splice portion is significant, the guide means and the corner of the leading end portion of the succeeding sheet collide with each other, causing trouble in conveyance. Can be prevented.

  Thus, the splicing part is detected, the guide means is retracted from the sheet, and the guide means is moved to an appropriate position after the splicing part has passed through the guide means. As a result, the change in the print position before and after the splice portion can be reduced, and a printing apparatus and a control method for the printing apparatus that do not stop the conveyance of the sheet can be realized.

(Seventh embodiment)
Hereinafter, a seventh embodiment of the present invention will be described with reference to the drawings. Since the basic configuration of the present embodiment is the same as that of the first embodiment, only the characteristic configuration will be described below.

  FIG. 8 is a diagram in which the shift amount measuring means 54 and the guide means 51 are removed from the internal configuration of the printing unit 4 in FIG. 5A, and a sheet positioning means is provided by the skew feeding roller 60 and the guide means 61. is there.

  In this embodiment, conveyance is performed while the oblique feeding roller 60 is pressed against the sheet at the leading edge of the sheet, and the widthwise positioning is performed at a position where the sheet gradually approaches the guide unit 61 and the sheet end surface is pressed against the guide unit 61. To do. However, for example, when a sheet with low stiffness is used, since the force from the skew feeding roller 60 may affect the conveyance during printing and deteriorate the print quality, the skew feeding roller 60 is not at the leading edge of the sheet. Release the pressure contact and remove the influence on the sheet conveyance.

  FIG. 9 is a flowchart showing the entire sequence of the printing operation in the present embodiment. When the printing operation is started, in step S300, the skew feeding roller 60 is driven at the leading edge of the sheet to position the sheet in the width direction. Subsequent steps S301 to S304 perform the same processing as steps S101 to S104 in FIG. In step S305, the skew feeding roller 60 is pressed against the sheet at the leading edge of the succeeding sheet to perform sheet positioning again, and then the skew feeding roller 60 is released. After step S306, processing similar to that after step S107 in FIG. 6 is performed.

  As a result, even if the sheet changes after passing through the splice portion, the sheet position equivalent to the preceding sheet can be maintained, and the change in the print position can be suppressed.

DESCRIPTION OF SYMBOLS 1 Sheet supply part 4 Print part 5 Inspection part 13 Control part 14 Print head part 31 Detection part 33 Paste part 34 Buffer part 51 Guide means 53 Platen 54 Deviation measuring means 60 Inclination feeding roller S Continuous sheet

Claims (9)

A printing apparatus capable of printing on a sheet including a price portion in which a preceding sheet and a succeeding sheet following the preceding sheet are connected,
A print unit that prints by discharging ink;
Detecting means for detecting the splice part,
When the detection unit detects the splice unit, the printing position of the printing unit is adjusted before printing on the succeeding sheet is started.   Measuring means for measuring a deviation amount between the preceding sheet and the succeeding sheet in a direction intersecting the conveyance direction, and adjusting a print position in a direction intersecting the conveyance direction based on the measured deviation amount. The printing apparatus according to claim 1, wherein:   The printing apparatus according to claim 1, wherein the adjustment of the print position is adjustment of a position of a print head included in the print unit.   The printing apparatus according to claim 1, wherein the adjustment of the print position is a change of a nozzle used by a print head included in the print unit.   The printing apparatus according to claim 1, wherein the adjustment of the print position is performed by shifting a position of the subsequent sheet.   The printing apparatus according to claim 1, wherein the adjustment of the printing position is a movement of a guide unit that regulates a width direction of the sheet.   The printing apparatus according to claim 2, wherein the measuring unit measures the shift amount by detecting an end portion of the sheet in the width direction of the sheet.   When the detecting means detects the splice portion, the measuring means measures the deviation amount a plurality of times across a predetermined conveyance amount of the sheet, and the print position is adjusted based on the plurality of measurements. The printing apparatus according to claim 2, wherein the printing apparatus is performed. A method for printing on a sheet including a splice portion in which a preceding sheet and a succeeding sheet following the preceding sheet are connected,
When the splice is detected, the print position is adjusted before printing on the succeeding sheet is started.

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