JP2006326993A - Liquid droplet delivering and recording apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a liquid droplet delivering and recording apparatus capable of suppressing deformation in the carrying direction of an image recorded on a recording paper caused by expansion and contraction of a carrying belt. <P>SOLUTION: An image pick-up is performed by a line sensor 36 on every prescribed period, and mark positional information indicating a position of a mark 38 in an image picking-up region of the line sensor 36 is acquired. Whenever the position of the mark 38 indicated by the acquired mark positional information is moved by a prescribed amount, a timing signal to be used as a timing for delivering liquid droplets from a liquid droplet delivering head is formed. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a droplet discharge recording apparatus that records an image by discharging droplets from a droplet discharge head onto a recording medium conveyed by a conveyance belt.

  Conventionally, ink images of a plurality of colors (for example, black (K), cyan (C), magenta (M), and yellow (Y)) are ejected from a droplet ejection head to form a color image on a recording medium such as recording paper. 2. Related Art An ink jet recording apparatus (so-called ink jet printer) for recording is known. Inkjet recording devices have a growing tendency to increase the recording speed, and the droplet discharge head is made longer than the recording paper width to record lines in the entire width direction of the recording paper. There is a type of recording an image on a recording sheet by recording line by line from the droplet discharge head while conveying the sheet by a conveying belt.

  By the way, in this type of ink jet recording apparatus, each line is recorded at a constant interval according to the resolution of the image to be recorded. Is being discharged.

As a technique for generating the timing at which ink liquid is ejected from this droplet ejection head, Patent Document 1 discloses that marks are provided on the transport belt at predetermined intervals along the transport direction, and each mark is read by an encoder. Thus, a technique for outputting a timing signal indicating the ejection timing of the ink liquid has been proposed. Patent Documents 2 and 3 propose a technique in which slits are provided in the conveyance belt at predetermined intervals, and a timing signal indicating the ink liquid discharge timing is output by detecting the slits with a sensor. .
JP 2004-155563 A JP 2004-17458 A JP-A-11-170623

  By the way, the conveyance belt may slightly expand and contract in the conveyance direction due to the magnitude of tension applied to stretch the conveyance belt, waviness, wrinkles, and the like.

  For this reason, when a mark or a slit is provided on the conveyor belt as in Patent Documents 1 to 3, the interval between the mark and the slit expands and contracts according to the expansion and contraction of the conveyor belt. The interval of the recorded lines will also be expanded and contracted.

  However, even when the transport belt expands and contracts, the recording paper to be transported does not expand and contract. Therefore, when the transport belt expands and contracts, an image recorded on the recording paper is deformed in the transport direction. There was a problem that there were cases.

  The present invention has been made to solve the above-described problems, and provides a droplet discharge recording apparatus that can suppress deformation of an image recorded on a recording sheet due to expansion and contraction of a conveyance belt in the conveyance direction. Objective.

  The invention of claim 1 is a droplet discharge recording apparatus for recording an image by discharging droplets from a droplet discharge head to a recording medium being transported, in the transport direction with the recording medium adsorbed. An endless conveyance belt in which a mark is attached to a non-adsorption area of the recording medium, and the conveyance direction in the longitudinal direction of the imaging area. A line sensor arranged so that the mark is imaged over the entire area in the longitudinal direction of the imaging area when the conveyor belt is driven in a circular manner, and the line sensor by a predetermined period An acquisition unit that performs imaging and acquires mark position information indicating the position of the mark in the imaging region of the line sensor, and the mark position information acquired by the acquisition unit Each time the position of the mark to be to move a predetermined amount, and a, a generation unit for generating a timing signal used as a timing of ejecting liquid droplets from the droplet discharge head.

  According to the first aspect of the present invention, there is provided a conveyance belt that adsorbs a recording medium and has a mark on a non-adsorption area of the recording medium, and a longitudinal direction of an imaging area coincides with a conveyance direction of the recording medium and the conveyance belt And a line sensor arranged so that the mark is imaged over the entire area in the longitudinal direction of the imaging area when driven in a circle, and the conveyance belt conveys the recording medium while adsorbing the recording medium. And the recording medium is passed through the image recording position by the droplet discharge head.

  At this time, the acquisition unit performs imaging by the line sensor at predetermined intervals, acquires mark position information indicating the position of the mark in the imaging region of the line sensor, and the generation unit acquires by the acquisition unit Each time the position of the mark indicated by the mark position information is moved by a predetermined amount, a timing signal used as a timing for ejecting droplets from the droplet ejection head is generated. Note that a timing that is N times or 1 / N times (N is a positive integer) the timing indicated by the timing signal may be used as the timing at which droplets are ejected from the droplet ejection head.

  As described above, according to the first aspect of the present invention, imaging by the line sensor is performed every predetermined period, mark position information indicating the position of the mark in the imaging area of the line sensor is acquired, and the acquired mark position information Each time the position of the mark indicated by is moved by a predetermined amount, a timing signal used as a timing for ejecting droplets from the droplet ejection head is generated. Deformation in the direction can be suppressed.

  According to the present invention, as in the invention described in claim 2, the line sensor has the same resolution as that of an image recorded on the recording medium, and the generation means is indicated by the mark position information. It is also possible to generate a timing signal with the timing at which the position of the mark to be shifted is one dot as the timing at which the droplet is ejected from the droplet ejection head.

  In the invention according to claim 1 or 2, as in the invention according to claim 3, the length of the imaging region of the line sensor in the transport direction is longer than the length of the recording medium in the transport direction. The transport belt may be configured such that the mark is attached to the transport belt at an interval longer than the length of the imaging area of the line sensor in the transport direction.

  In the invention according to claim 1 or 2, as in the invention according to claim 4, the length of the imaging region of the line sensor in the transport direction is shorter than the length of the recording medium in the transport direction. In addition, a plurality of the line sensors are provided in parallel along the conveyance direction, and the conveyance belt is arranged at predetermined intervals with respect to the conveyance direction, and with the circumferential driving of the conveyance belt, When the image is picked up by any one of the line sensors and the position of the mark passes through a predetermined range on the downstream side in the transport direction of the pick-up area of the one line sensor, the mark of the pick-up area of any one of the other line sensors It is assumed that a plurality of marks are added so that the next mark is picked up in a predetermined range on the upstream side in the transport direction, and the acquisition unit picks up images by each line sensor every predetermined period. And obtaining the mark position information in the imaging area of each line sensor, and the generating means obtains each line sensor from the mark position information in the imaging area of each line sensor obtained by the obtaining means. Generating the timing signal for each line sensor, and, from the timing signal for each of the line sensors generated by the generation unit, imaging the mark in a predetermined range on the upstream side in the transport direction of the imaging region. When the timing signal is applied and the position of the mark becomes a predetermined range on the downstream side in the transport direction of the imaging area of the line sensor as the conveyor belt rotates, the transport of the next mark in the imaging area is performed. Select to apply the timing signal of the line sensor imaged in a predetermined range upstream in the direction. Selection means for, may further include a.

  According to a fourth aspect of the present invention, as in the fifth aspect of the present invention, the next signal is obtained with reference to the timing signal of the line sensor that images the mark in a predetermined range on the upstream side in the transport direction of the imaging region. A calculating means for calculating a delay time based on a phase difference from the timing signal of the line sensor in which the mark is imaged in a predetermined range on the upstream side in the conveyance direction of the imaging area; and the timing signal of the next mark is calculated by the selecting means. When selected, it is preferable to further include delay means for performing a delay process for delaying the timing for ejecting the droplet indicated by the timing signal by the delay time calculated by the calculation means.

  In the invention according to claim 1 or 2, as in the invention according to claim 6, the length of the imaging region of the line sensor in the transport direction is shorter than the length of the recording medium in the transport direction. In addition, one line sensor is provided, and the conveyor belt is configured such that the mark is imaged at predetermined intervals in the conveyance direction, and the mark imaged by the line sensor is used to drive the conveyor belt. Accordingly, when passing through a predetermined range on the downstream side in the transport direction of the imaging area of the line sensor, a plurality of marks are attached so that the next mark is captured in a predetermined range on the upstream side in the transport direction of the imaging area of the line sensor. An upstream masked position obtained by masking a predetermined range of data upstream of the imaging region in the transport direction from the mark position information acquired by the acquisition unit And a creation means for creating downstream masked position information obtained by masking a predetermined range of data downstream of the imaging region in the transport direction, and the creation means are each created by the creation means. Each time the mark position indicated by the upstream masked position information and the downstream masked position information moves by the predetermined amount, two timing signals are generated to indicate the timing at which the droplet is ejected from the droplet ejection head. The timing signal generated from the downstream-side masked position information is applied from the two timing signals generated by the generating means, and the mark position is determined by the line sensor as the conveyor belt rotates. Apply the timing signal generated from the upstream masked position information when it becomes the center of the imaging area When the position of the mark falls within a predetermined range on the downstream side in the transport direction of the line sensor as the transport belt is driven, it is generated from the downstream masked position information created by imaging the next mark. Selection means for selecting to apply the timing signal may be further provided.

  According to a sixth aspect of the invention, as in the seventh aspect of the invention, the downstream side created by imaging the next mark with reference to the timing signal generated from the upstream masked position information. A calculation unit that calculates a delay time based on a phase difference from the timing signal generated from the masked position information, and when the timing signal of the next mark is selected by the selection unit, is indicated by the timing signal. It is preferable that the apparatus further includes a delay unit that performs a delay process for delaying a timing at which the droplet is ejected by a delay time calculated by the calculation unit.

  Further, according to the present invention, as in the invention according to claim 8, the conveying belt is attached to a back surface which is the back side of the side where the mark faces the droplet discharge head with respect to the conveying belt. The line sensor may be arranged on the back surface side so as to image the mark attached to the back surface.

  As described above, according to the present invention, imaging by a line sensor is performed every predetermined period, mark position information indicating the position of a mark in the imaging area of the line sensor is acquired, and the acquired mark position information is used. Each time the indicated mark moves by a predetermined amount, a timing signal is generated that is used as a timing for ejecting droplets from the droplet ejection head, so the conveyance direction of the image recorded on the recording paper due to the expansion and contraction of the conveyance belt It has an excellent effect of being able to suppress deformation into a.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
[First Embodiment]
FIG. 1 shows the overall configuration of an ink jet recording apparatus 10 according to the present embodiment.

  The ink jet recording apparatus 10 includes a recording head array 12 that records an image by discharging ink liquid. The recording head array 12 includes four droplet discharge heads 14C, 14M, 14Y, and 14K corresponding to the colors C (cyan), M (magenta), Y (yellow), and K (black). . In the following description, an initial letter corresponding to each color is added to the code when distinguishing each color, and an initial letter corresponding to each color is omitted unless otherwise distinguished.

  Each droplet discharge head 14 is a long head having a recording area equal to or larger than the width of the recording paper P, and a large number of nozzles are arranged along the width direction of the recording paper P, and discharges ink liquid from each nozzle. Thus, the entire width of the recording paper P is recorded at once.

  Ink tanks 16 </ b> C, 16 </ b> M, 16 </ b> Y, and 16 </ b> K are provided corresponding to the respective droplet discharge heads 14. The ink liquid stored in the ink tank 16 is supplied to the droplet discharge head 14 corresponding to each color through a pipe (not shown).

  In the vicinity of the recording head array 12, a maintenance unit 15 that performs cleaning for preventing ink clogging of each droplet discharge head 14 and a suction recovery operation when ink clogging occurs is provided for each droplet discharge. It is provided corresponding to the head 14.

  The maintenance unit 15 is positioned on both sides of the recording head array 12 as shown in FIG. 1 during image recording, and moves to a position facing each nozzle of the recording head array 12 as shown in FIG. 2 during maintenance. It is configured as follows. Note that the configuration of the maintenance unit 15 is not limited to this, and any configuration may be used as long as it can be disposed so as to be able to face each nozzle of the recording head array 12 during maintenance.

  In addition, the inkjet recording apparatus 10 includes a paper feed tray 18 that stores the recording paper P. The recording paper P supplied from the paper feed tray 18 is conveyed by a plurality of roller pairs 20 to be recorded in the recording head array 12. Supplied to. An endless conveyance belt 24 wound around rollers 22A and 22B and a tension roller 23 is provided at a position facing the recording head array 12, and the tension belt 23 pulls the conveyance belt 24 downward. A constant tension is applied to the conveyor belt 24. The conveyance belt 24 is wider than the width in the direction orthogonal to the conveyance direction of the recording paper P, and is driven to rotate by the rotation of the rollers 22A and 22B and the tension roller 23, and the recording paper P conveyed by the plurality of roller pairs 20 is conveyed. The sheet is conveyed to a position facing the recording head array 12.

  A suction roller 26 is provided at a position facing the roller 22B. The recording paper P transported by the plurality of roller pairs 20 is attracted to the transport belt 24 by being charged by the suction roller 26 and being pressed by the transport belt 24.

  A plurality of roller pairs 28 and a transport roller 30 are provided on the downstream side of the transport belt 24 in the transport direction of the recording paper P. The recording sheet P on which an image is recorded by the recording head array 12 is conveyed by the plurality of roller pairs 28 and the conveying roller 30 and is discharged to the sheet discharge tray 32.

  Further, the inkjet recording apparatus 10 includes a reversing path 33 for double-sided recording. The reversing path 33 is composed of a plurality of roller pairs 35, and the recording paper P on which an image is recorded on one side by the recording head array 12 is reversed by the reversing path 33 to a position again facing the recording head array 12. Be transported. This makes it possible to record images on both sides of the recording paper P.

  FIG. 3 is a perspective view showing a detailed configuration of the recording head array 12 and the conveyance belt 24 according to the present embodiment.

  In the recording head array 12, one CCD (Charge Coupled Devices) line sensor 36 is arranged alongside the recording head array 12 in the width direction of the recording paper P of the conveyance belt 24.

  The CCD line sensor 36 is longer than the length of the largest recording paper P that can be recorded in the inkjet recording apparatus 10 in the transport direction, and has a predetermined resolution (in this embodiment, the same as the resolution that can be recorded in the inkjet recording apparatus 10). 1200 dpi).

  Further, as shown in FIGS. 4A and 4B, the conveyor belt 24 is fixed at a position corresponding to the CCD line sensor 36 and longer than the length of the CCD line sensor 36 along the conveyance direction of the recording paper P. A mark 38 is provided for each interval. In the present embodiment, marks 38 are attached at regular intervals. However, if the intervals are longer than the length of the CCD line sensor 36, the intervals need not be constant, and only one mark 38 is provided. It is good.

  The CCD line sensor 36 faces the conveyor belt 24, aligns the longitudinal direction of an imaging area (not shown) with the conveyance direction, and marks 36 extend over the entire longitudinal area of the imaging area when the conveyor belt 24 is driven to rotate. It arrange | positions so that it may image.

  In the present embodiment, imaging by the CCD line sensor 36 is performed at predetermined intervals, and the nozzles of the droplet discharge heads 14 of the recording head array 12 are based on the positions of the marks 38 in the imaging area of the CCD line sensor 36. A discharge timing signal indicating the timing at which the ink liquid is discharged is generated.

  FIG. 5 shows a schematic configuration of the electrical system of the inkjet recording apparatus 10 according to the present embodiment.

  The inkjet recording apparatus 10 includes a CPU (central processing unit) 40 that controls the entire operation, a ROM 42 that stores various programs including various control programs for controlling the entire apparatus, various parameters, and the like, and a communication medium such as a network (not shown). A communication interface 44 that receives image data recorded on the recording paper P from the terminal device 80, a data conversion unit 46 that converts the received image data into CMYK color image data, An image processing unit 48 that creates dot data of a predetermined number of gradations for each dot constituting a pixel of CMYK color, for example, data of relatively high gradations such as 256 gradations by halftone processing or the like. Yes.

  The data conversion unit 46 stores a color correction LUT (Look Up Table), converts image data into CMYK color image data, and performs color correction and density correction according to ink characteristics. Perform color correction processing.

  Further, since the image processing unit 48 records the dots constituting the pixel, for example, a dither method or an error diffusion method can be used as a halftone processing method, and the halftone processing is performed for each color of YMCK. Is called.

  On the other hand, the ink jet recording apparatus 10 converts the nozzle structure of each droplet discharge head 14 into a data structure that can be read by the head controller 54 based on the dot data created by the image processing unit 48, A recording data creation unit 50 that creates recording data in which data is rearranged in the recording order read from the head control unit 54, a RAM 52 that temporarily stores the created recording data and various data, and the like, and each roller is driven to rotate. The conveyance control unit 56 that controls the conveyance of the recording paper P by controlling a motor (not shown) and the CCD line sensor 36 perform imaging at a predetermined cycle, and the position of the mark 38 is a predetermined amount (in this embodiment, A discharge timing generation unit 58 that generates a discharge timing signal indicating the timing at which the ink liquid is discharged each time it moves. And a head control unit 54 that reads the recording data stored in the RAM 52 based on the timing indicated by the ejection timing signal and controls the output of the drive signal to the piezoelectric element corresponding to each nozzle of each droplet ejection head 14; It is equipped with.

  The CPU 40, ROM 42, RAM 52, data converter 46, image processor 48, communication interface 44, head controller 54, transport controller 56, print data generator 50, and ejection timing generator 58 are connected via the system bus BUS. Are connected to each other. Therefore, the CPU 40 controls the access to the ROM 42 and the RAM 52, the data processing by the data conversion unit 46, the image processing unit 48, and the recording data creation unit 50, and the conveyance of the recording paper P by controlling the conveyance control unit 56. The control and the control of the recording process on the recording paper P by controlling the head control unit 54 at the timing based on the ejection timing signal output from the ejection timing generation unit 58 can be performed.

  FIG. 6 shows a detailed configuration of the discharge timing generation unit 58 according to the present embodiment.

  The ejection timing generation unit 58 stores the line sensor control unit 60 that controls the CCD line sensor 36 to capture images at predetermined intervals, and the latest two times of data captured by the line sensor control unit 60. The memory 62 to be compared with the data for two times stored in the memory 62, and the comparison result by the data comparison unit 64 that outputs the comparison result and the comparison result by the data comparison unit 64, indicating that the position of the mark 38 has moved in the imaging region. When detected, a pulse signal generation unit 66 that outputs a pulse as an ejection timing signal is provided.

  Next, an operation flow of the inkjet recording apparatus 10 when an image is recorded on a recording medium by the inkjet recording apparatus 10 according to the present embodiment will be described.

  When the user instructs recording of image data from the terminal device 80, the inkjet recording device 10 receives the image data from the terminal device 80 via the communication medium via the communication interface 44.

  The received image data is converted into CMYK color image data by the data conversion unit 46, and color correction processing such as color correction and density correction according to the ink characteristics of each color is performed using the color correction LUT. . The image processing unit 48 performs halftone processing based on the image data converted into CMYK colors, and creates dot data for each dot according to the gradation value of each pixel. The recording data creation unit 50 converts the dot data into recording data that takes into account the arrangement of the nozzles of the droplet discharge heads 14 and stores the data in the RAM 52.

  When the recording data is stored in the RAM 52, the conveyance control unit 56 controls a motor (not shown) to start the rotation of the conveyance belt 24 and to start conveyance of the recording paper P stored in the paper feed tray 18. The rollers are driven to supply the recording paper P onto the conveying belt 24 so that the leading position of the recording paper P is aligned with the position of the mark 38 on the conveying belt 24. The recording paper P supplied onto the conveying belt 24 is conveyed to an image recording position facing the recording head array 12 together with the circumferential driving of the conveying belt 24.

  In the ejection timing generation unit 58, the CCD line sensor 36 images the mark 38 on the conveyor belt 24 at predetermined intervals, and outputs an ejection timing signal.

  The head controller 54 reads the recording data stored in the RAM 52 based on the timing of the ejection timing signal, and outputs a drive signal to each droplet ejection head 14 based on the recording data. As a result, the ink liquid is ejected from the nozzles of the respective droplet ejection heads 14 and an image is recorded on the recording paper P.

  FIG. 7 shows an example of data obtained by imaging at predetermined intervals by the line sensor control unit 60.

  When the CCD line sensor 36 is controlled and imaging is performed at predetermined intervals, the memory 62 stores the newest two times of the captured data. That is, the memory 62 stores only twice of the data obtained by the imaging of FIG.

  The data comparison unit 64 compares the data for two times stored in the memory 62, and the pulse signal generation unit 66 compares the comparison result by the data comparison unit 64 with the timing at which the two data do not match (arrow t1 in FIG. 7). And t2), a pulse is generated and an ejection timing signal is output.

  In the present embodiment, the CCD line sensor 36 has a predetermined resolution that is the same as the resolution that can be recorded by the ink jet recording apparatus 10, so the mark 38 moves one dot in the transport direction when the data does not match twice. It will be the timing. Therefore, by generating a pulse at the timing when the mark 38 has moved by one dot, the ejection timing can be appropriately generated.

  For example, in the ink jet recording apparatus 10 according to the present embodiment, the ejection timing signal required for ejecting ink from each nozzle of the droplet ejection head 14 and recording an image on the recording paper P being conveyed at 1200 dpi. When the frequency is 10 kHz, the mark 38 is imaged by the CCD line sensor 36 at, for example, 100 kHz, which is 10 times 10 kHz (the predetermined period of imaging is set to 1 / 100,000 seconds), so that the discharge timing signal is used. With respect to the timing of ink liquid ejection, the ink liquid can be ejected with an error of 10% with respect to the logically most suitable recording position, and dots can be recorded. When recording an image at 1200 dpi, the inkjet recording apparatus 10 records each line on the recording paper P at intervals of 21.16 μm, but each line has a recording position error of 10% (10% ( 2 μm) can be recorded. Generally, the error that can be recognized by human vision is 10 μm or more, so this error of 2 μm is a level that does not affect the image quality.

  As described above, according to the first embodiment, the recording medium (here, the recording paper P) is sucked and the non-sucking area of the recording medium is marked, and the longitudinal direction of the imaging area is set. A line sensor (here, a CCD line) arranged so that the mark is imaged over the entire area in the longitudinal direction of the imaging area when the conveyance belt is driven to rotate around the conveyance direction of the recording medium. The conveyance belt is driven to rotate in the conveyance direction while adsorbing the recording medium, and passes the recording medium through the image recording position by the droplet discharge head. At this time, the acquisition unit (here, the line sensor control unit 60) causes the line sensor to perform imaging at predetermined intervals, and acquires mark position information indicating the position of the mark in the imaging area of the line sensor. The generation unit (here, the pulse signal generation unit 66) discharges a droplet from the droplet discharge head every time the mark position indicated by the mark position information acquired by the acquisition unit moves by a predetermined amount. Since a timing signal (here, an ejection timing signal) used as the timing for generating the image is generated, it is possible to suppress deformation of the image recorded on the recording paper due to expansion and contraction of the conveyance belt in the conveyance direction.

  According to the first embodiment, the line sensor has the same resolution as the resolution of the image recorded on the recording medium, and the generation means is the mark position indicated by the mark position information. Since the timing signal is generated with the timing at which one dot is shifted by one dot as the timing at which droplets are ejected from the droplet ejection head, it is possible to generate the timing at which appropriate ink liquid is ejected according to the resolution.

  According to the first embodiment, the length of the imaging area of the line sensor in the transport direction is longer than the length of the recording medium in the transport direction, and the transport belt is connected to the mark by the mark. Since it is attached to the conveyor belt at an interval longer than the length of the imaging area of the line sensor with respect to the direction, it is possible to generate a necessary ejection timing signal while recording one recording medium.

[Second Embodiment]
In the second embodiment, an example in which two CCD line sensors are arranged in parallel in the recording head array 12 and a timing signal is generated by the two CCD line sensors will be described. The configuration of the ink jet recording apparatus 10 according to the second embodiment is the same as that shown in FIGS.

  FIG. 8 is a perspective view showing a detailed configuration of the recording head array 12 and the conveyance belt 24 according to the second embodiment.

  The recording head array 12 according to the second embodiment is provided with two CCD line sensors 36A and 36B having the same configuration along the recording head array 12 in the width direction of the recording paper P of the transport belt 24. The two CCD line sensors 36A and 36B are arranged in parallel along the conveyance direction of the recording paper P. Although the number of CCD line sensors is two in the second embodiment, the number of CCD line sensors is not limited to this, and may be two or more.

  The CCD line sensors 36A and 36B according to the second embodiment have a predetermined length (148 mm in this embodiment) shorter than the length of the maximum recording paper P that can be recorded by the inkjet recording apparatus 10 in the transport direction. Further, it has a predetermined resolution (1200 dpi in the present embodiment) that is the same as the resolution that can be recorded by the inkjet recording apparatus 10, and is positioned at 7000 locations by 7000 light receiving elements each along the transport direction. The mark 38 can be imaged with (dot).

  In addition, as shown in FIG. 9, the transport belt 24 according to the second embodiment is alternately arranged at positions corresponding to the CCD line sensor 36A and the CCD line sensor 36B along the transport direction of the recording paper P. Marks 38 are provided at equal intervals. The interval between the marks 38 in the conveyance direction is a predetermined interval shorter than the length of the CCD line sensors 36A and 36B in the conveyance direction by a predetermined value (in this embodiment, 140 mm, 6600 dots). In the present embodiment, the mark 38 is imaged in the imaging area of one of the CCD line sensors 36A and 36B, and the mark 38 is captured in the imaging area of one CCD line sensor as the conveyor belt 24 moves. When a predetermined range on the downstream side in the transport direction (in this embodiment, a range of 6500 to 6999 dots) is reached, a predetermined range on the upstream side in the transport direction of the imaging region of the other CCD line sensor (in this embodiment, In the range of 0 to 499 dots), the next mark 38 is imaged.

  In addition, in the inkjet recording apparatus 10 according to the second embodiment, a predetermined position (this book) upstream of the imaging area of the CCD line sensors 36A and 36B in parallel with the CCD line sensor 36B in the transport direction. In the embodiment, the home position sensor 37 is disposed at a position corresponding to the position in the vicinity of the 100th dot) and the conveyance direction. On the conveyor belt 24, one home position mark 39 is positioned in parallel with any one mark 38 imaged by the CCD line sensor 36A and can be detected by the home position sensor 37 as the conveyor belt 24 rotates. Is provided.

  The home position sensor 37 outputs a home position signal when it detects that the home position mark 39 has passed the opposite position as the conveyor belt 24 rotates.

  FIG. 10 shows a schematic configuration of an electric system of the ink jet recording apparatus 10 according to the second embodiment. In addition, about the same component as FIG. 5 of the same figure, the same code | symbol location as FIG. 5 is attached | subjected, and the description is abbreviate | omitted.

The discharge timing generation unit 58 is connected to the CCD line sensors 36A and 36B and the home position sensor 37, and based on the position of the mark 38 in the imaging area imaged by the CCD line sensors 36A and 36B at predetermined intervals. FIG. 11 shows a detailed configuration of the discharge timing generation unit 58 according to the second embodiment.

  The discharge timing generation unit 58 corresponds to each of the CCD line sensor 36A and the CCD line sensor 36B, line sensor control units 60A and 60B, memories 62A and 62B, and data comparison units 64A and 64B that perform the same processing as in FIG. And pulse signal generators 66A and 66B. In addition, "A" is attached to the code corresponding to the CCD line sensor 36A, and "B" is added to the code corresponding to the CCD line sensor 36B.

  The pulse signal generation unit 66A outputs a discharge timing signal to a selector 70, a delay time calculation unit 72, and a counter 76A, which will be described later, and the pulse signal generation unit 66B outputs a discharge timing signal to a selector 70, a delay time calculation unit, which will be described later. 72 and the counter 76B.

  The ejection timing generation unit 58 according to the second embodiment counts the number of pulses of the ejection timing signal input from the pulse signal generation unit 66A, and outputs a delay time calculation instruction signal and a switching instruction signal according to the number of pulses. The counter 76A counts the number of pulses of the ejection timing signal input from the pulse signal generator 66B, and outputs a delay time calculation instruction signal and a switching instruction signal according to the number of pulses, and the delay time from the counters 76A and 76B. When the calculation instruction signal is input, a delay for calculating a delay time corresponding to a time difference from the pulse of the other discharge timing signal with one of the pulses of the discharge timing signal input from the pulse signal generators 66A and 66B as a reference. When a switching instruction signal is input from the time calculator 72 and the counter 76A, a pulse signal is generated. The discharge timing signal input from the unit 66B is output, and when the switching instruction signal is input from the counter 76B, the selector 70 outputs the discharge timing signal input from the pulse signal generation unit 66A, and the discharge timing input from the selector 70 The apparatus further includes a delay processing unit 74 that performs a delay process on the delay time calculated by the delay time calculation unit 72 and outputs a discharge timing signal after the delay process.

  Note that the counter 76A counts the number of pulses of the ejection timing signal input from the pulse signal generation unit 66A, and the number of pulses becomes a first count value (6800 in the present embodiment) corresponding to the interval of the marks 38. The switching instruction signal is output to the selector 70, the delay processing unit 74, and the counter 76B, and the delay time calculation instruction signal is delayed when the second count value (6798 in the present embodiment) is smaller than the first count value. It outputs to the time calculation part 72. Further, when the home position signal is input from the home position sensor 37 and when the switching instruction signal is input from the counter 76B described later, the counter 76A initializes the number of pulses to zero and starts counting again.

  The counter 76B counts the number of pulses of the switching instruction signal input from the pulse signal generation unit 66B. When the number of pulses reaches the first count value, the counter 76B sends the switching instruction signal to the counter 76A, the delay processing unit 74, and the selector 70. When the second count value is reached, a delay time calculation instruction signal is output to the delay time calculation unit 72. In addition, when the home position signal is input from the home position sensor 37 and when the switching instruction signal is input from the counter 76A, the counter 76B initializes the number of pulses to zero and starts counting again.

  Further, when the delay time calculation instruction signal is input from the counter 76A, the delay time calculation unit 72 uses the pulse of the discharge timing signal input from the pulse signal generation unit 66A as a reference, and outputs the discharge timing signal input from the pulse signal generation unit 66B. The delay time is calculated by obtaining the time difference from the pulse. In addition, when the delay time calculation instruction signal is input from the counter 76B, the delay time calculation unit 72 uses the pulse of the discharge timing signal input from the pulse signal generation unit 66B as a reference for the discharge timing signal input from the pulse signal generation unit 66A. The delay time is calculated by obtaining the time difference from the pulse.

  Next, an operation flow of the discharge timing generation unit 58 when the discharge timing signal is output by the discharge timing generation unit 58 according to the second embodiment will be described.

  The line sensor control unit 60A controls the CCD line sensor 36A, and the line sensor control unit 60B controls the CCD line sensor 36B and images the mark 38 on the transport belt 24 at predetermined intervals.

  The pulse signal generation unit 66A outputs an ejection timing signal when the mark 38 faces the imaging region of the CCD line sensor 36A as the conveyance belt 24 rotates, and the pulse signal generation unit 66B outputs the imaging region of the CCD line sensor 36B. When the mark 38 opposes, a discharge timing signal is output.

  Further, when the home position sensor 37 detects the above-described home position mark 39, the home position sensor 37 outputs a home position signal as shown in FIG.

  In the counter 76A and the counter 76B, when the home position signal is input, the number of pulses is initialized to zero.

  The counter 76A counts the number of pulses of the ejection timing signal input from the pulse signal generator 66A. At this time, it is assumed that the selector 70 outputs the ejection timing signal input from the pulse signal generation unit 66A.

  In the counter 76A, the mark 38 imaged by the CCD line sensor 36A becomes the predetermined range on the downstream side in the conveyance direction of the imaging area of the line sensor 36A as the conveyance belt 24 is driven to rotate, and is counted by the counter 76A. When the number of pulses that have reached the second count value (6798 in this embodiment), a delay time calculation instruction signal is output to the delay time calculation unit 72. At this time, the next mark 38 is imaged in the predetermined range on the upstream side in the conveyance direction of the imaging area of the CCD line sensor 36B along with the circumferential driving on the conveyance belt 24, and the pulse signal generation unit 66B A discharge timing signal is output.

  When the delay time calculation instruction signal is input from the counter 76A, the delay time calculation unit 72 uses the pulse of the discharge timing signal input from the pulse signal generation unit 66A as a reference and the pulse of the discharge timing signal input from the pulse signal generation unit 66B. The delay time t3 is calculated by comparing the rising timing.

  When the counted number of pulses reaches the first count value (6800 in this embodiment), the counter 76A outputs a switching instruction signal to the selector 70, the delay processing unit 74, and the counter 76B.

  When the switching instruction signal is input from the counter 76A, the selector 70 switches the output discharge timing signal to output the discharge timing signal input from the pulse signal generation unit 66B.

  When the switching instruction signal is input from the counter 76A, the delay processing unit 74 performs a delay process of the delay time t3 calculated by the delay time calculating unit 72 on each pulse of the discharge timing signal input from the selector 70, and discharges the discharge. A timing signal is output to the system bus BUS.

  As described above, in the ejection timing generation unit 58 according to the second embodiment, the mark 38 imaged in the imaging region of the CCD line sensor 36A is imaged by the CCD line sensor 36A in accordance with the circumferential driving on the transport belt 24. When the predetermined range is reached downstream in the conveyance direction of the region, an ejection timing signal from the pulse signal generation unit 66B generated by imaging the mark 38 in the CCD line sensor 36B is output.

  12A, when the ejection timing signal output by the selector 70 is switched, the phase of the ejection timing signal output from the delay processing unit 74 is the same as the phase of the ejection timing signal before switching. Therefore, it is possible to prevent the image recorded at the time of switching from being deteriorated.

  The counter 76B initializes the number of pulses to zero when the switching instruction signal is input from the counter 76A, and counts the number of pulses of the ejection timing signal input from the pulse signal generation unit 66B.

  Then, as shown in FIG. 12B, the counter 76B is configured so that the mark 38 imaged in the imaging area of the CCD line sensor 36B moves in the imaging area of the CCD line sensor 36B as it is driven around the conveyor belt 24. When the predetermined range on the downstream side in the transport direction is reached and the number of pulses reaches the second count value (6798 in this embodiment), a delay time calculation instruction signal is output to the delay time calculation unit 72. When the delay time calculation instruction signal is input from the counter 76B, the delay time calculation unit 72 receives the discharge timing input from the pulse signal generation unit 66A with reference to the rising timing of the pulse of the discharge timing signal input from the pulse signal generation unit 66B. The delay time t4 is calculated by comparing the rising timings of the signal pulses. At this time, the mark 38 is also imaged in the predetermined range on the upstream side in the conveyance direction of the imaging area of the CCD line sensor 36A along with the circumferential driving on the conveyance belt 24, and the ejection timing signal is also output from the pulse signal generation unit 66A. Will be output.

  When the counted number of pulses reaches the first count value (6800 in this embodiment), the counter 76B outputs a switching instruction signal to the selector 70, the counter 76A, and the delay processing unit 74. As a result, the timing generation unit 58 switches the ejection timing signal to be output from the ejection timing signal generated by the pulse signal generation unit 66B to the ejection timing signal generated by the pulse signal generation unit 66A. Accordingly, the ejection timing signal subjected to the delay process by the delay time calculation unit 72 is output to the system bus BUS. In addition, the counter 76A initializes the number of pulses to zero and starts counting again.

  Note that the delay processing unit 74 performs a delay process on each pulse of the input ejection timing signal for a time obtained by accumulating the delay times calculated by the delay time calculating unit 72. The delay processing unit 74 calculates the average period T of the pulses of the input ejection timing signal. When the time (t3 + t4) is greater than the average period T by accumulating the delay time t, the average is calculated (t3 + t4> T). The period T is delayed by a time minus (t3 + t4-T).

  As described above, according to the second embodiment, the length of the imaging region of the line sensor in the transport direction is shorter than the length of the recording medium in the transport direction, and the line sensor is moved in the transport direction. A plurality of conveying belts are provided in parallel along the conveying direction, and the marks are imaged by any one of the line sensors at predetermined intervals with respect to the conveying direction and with the circumferential driving of the conveying belt. When the position of the first mark passes through a predetermined range on the downstream side in the conveyance direction of the imaging region of the one line sensor, the next mark is imaged in the predetermined range on the upstream side in the conveyance direction of the imaging region of any one of the other line sensors. The acquisition means (here, the line sensor control units 60A and 60B) performs imaging by each of the line sensors at predetermined intervals. The mark position information in the imaging area of each line sensor is acquired, and the generation means (here, the pulse signal generation units 66A and 66B) acquires the mark in the imaging area of each line sensor acquired by the acquisition means. The timing signal for each of the line sensors is generated from the position information, and the selection unit (here, the selector 70), from the timing signal for each of the line sensors generated by the generation unit, Applying the timing signal of the line sensor obtained by imaging the mark in a predetermined range upstream of the imaging region in the conveyance direction, the position of the mark is downstream in the conveyance direction of the imaging region of the line sensor as the conveyor belt rotates. The next mark on the upstream side in the transport direction of the imaging area. Since the timing signal of the line sensor imaged in the range is selected to be applied, an image is recorded on the recording medium even if the length of the line sensor in the conveyance direction is shorter than the length of the recording medium in the conveyance direction. Therefore, a discharge timing signal can be generated.

  Further, according to the second embodiment, the calculating means (here, the delay time calculating unit 72) calculates the timing signal of the line sensor that images the mark in the predetermined range on the upstream side in the transport direction of the imaging region. As a reference, a delay time based on a phase difference with the timing signal of the line sensor obtained by imaging the next mark in a predetermined range upstream of the imaging region in the transport direction is calculated, and a delay unit (here, a delay processing unit 74) is calculated. ) Is a delay process for delaying the timing for ejecting the droplet indicated by the timing signal by the delay time calculated by the calculation means when the timing signal of the next mark is selected by the selection means. Therefore, the phase of the output discharge timing signal is the same as the phase of the discharge timing signal before switching, Image can be prevented from being deteriorated that.

  In the second embodiment, the case where the home position signal is output from the home position sensor 37 has been described. However, the present invention is not limited to this, and for example, the line sensor control unit 60A may include a CCD line. At the timing when the mark 38 is detected at the position of the 6798th dot on the downstream side in the transport direction of the imaging area of the sensor 36A, a time calculation instruction signal is output to the delay time calculation unit 72, and the mark 38 is detected at the position of the 6800th dot. At this timing, a switching instruction signal is output to the selector 70 and the delay processing unit 74, and the line sensor control unit 60B detects the mark 38 at the 6798th dot position on the downstream side in the transport direction of the imaging area of the CCD line sensor 36B. The time calculation instruction signal is output to the delay time calculation unit 72 at the same timing. 6800 at the timing of detection of the mark 38 at the position of th dot may output a switching instruction signal to the selector 70 and the delay processing section 74. Also in this case, the same effects as in the present embodiment can be obtained.

[Third Embodiment]
In the third embodiment, the recording head array 12 is provided with one CCD line sensor shorter than the length along the conveyance direction of the maximum recording paper P that can be recorded by the ink jet recording apparatus 10, and the ink liquid is supplied. An example of generating a timing signal indicating the discharge timing will be described. The configuration of the ink jet recording apparatus 10 according to the third embodiment is the same as that shown in FIGS.

  FIG. 13 is a perspective view showing a detailed configuration of the recording head array 12 and the transport belt 24 according to the third embodiment.

  In the recording head array 12 according to the third embodiment, one CCD line sensor 36 is arranged alongside the recording head array 12 in the width direction of the recording paper P of the transport belt 24. The CCD line sensor 36 has a predetermined length (148 mm in the present embodiment) and a predetermined resolution (in the present embodiment, in the same manner as the CCD line sensors 36A and 36B according to the second embodiment). 1200 dpi).

  Further, as shown in FIG. 14, the conveyance belt 24 according to the third embodiment is provided with a mark 38 at a position corresponding to the CCD line sensor 36 along the conveyance direction of the recording paper P. The interval of the mark 38 in the conveyance direction is a predetermined interval (140 mm in the present embodiment) shorter than the length of the CCD line sensor 36 in the conveyance direction by a predetermined value. That is, in this embodiment, when a mark is detected by the CCD line sensor 36 and the mark 38 becomes an end portion of the detection target area of the CCD line sensor 36 as the transport belt 24 moves, the CCD line sensor 36 The mark 38 is detected.

  Further, in the inkjet recording apparatus 10 according to the third embodiment, a predetermined position (in the present embodiment) on the upstream side in the transport direction of the imaging region of the CCD line sensor 36 in parallel with the CCD line sensor 36 in the transport direction. In the embodiment, the home position sensor 37 is disposed at a position corresponding to the position in the vicinity of the 200th dot) and the conveyance direction. In addition, a single home position mark 39 is provided on the transport belt 24 in parallel with the mark 38 and at a position that can be detected by the home position sensor 37 as the transport belt 24 rotates.

  FIG. 19 shows a schematic configuration of an electrical system of the inkjet recording apparatus 10 according to the third embodiment. In addition, about the same component as FIG. 5 of the same figure, the same code | symbol location as FIG. 5 is attached | subjected, and the description is abbreviate | omitted.

  The ejection timing generation unit 58 is connected to the CCD line sensor 36 and the home position sensor 37, and is a timing for ejecting ink liquid based on the position of the mark 38 in the imaging area imaged by the CCD line sensor 36 at predetermined intervals. Output a signal.

  FIG. 15 shows a detailed configuration of the discharge timing generation unit 58 according to the third embodiment. In addition, about the same component as FIG. 11 of the same figure, the same code | symbol location as FIG. 11 is attached | subjected, and the description is abbreviate | omitted.

  The ejection timing generation unit 58 controls the CCD line sensor 36 to perform imaging at predetermined intervals, and the imaging area of the CCD line sensor 36 from data obtained by imaging by the line sensor control unit 60. A first mask processing unit 90A that masks data within a predetermined range (in the present embodiment, a range of 0 to 499 dots) on the upstream side in the transport direction, and outputs the masked data to the memory 62A, and a line sensor control unit 60, data in a predetermined range (in the present embodiment, a range of 6500 to 6999 dots) on the downstream side in the transport direction of the imaging area of the CCD line sensor 36 is masked from the data obtained by imaging by the image sensor 60, and the masked data is stored in the memory 62B. And a second mask processing unit 90B that outputs to

  When the delay time calculation instruction signal is input from the counter 76, the delay time calculation unit 72 uses the discharge timing signal input from the pulse signal generation unit 66A as a reference and the pulse of the discharge timing signal input from the pulse signal generation unit 66B. A delay time corresponding to the time difference is calculated.

  The counter 76 counts the number of pulses of the ejection timing signal input from the delay processing unit 74, and the first count value (6600 in the present embodiment) corresponding to the interval between the marks 38 and the central part are counted. When a third count value (3300 in the present embodiment) is reached, a switching instruction signal is output, and when the second count value (6598 in the present embodiment) is smaller than the first count value, the switching instruction signal is output. Outputs a delay time calculation instruction signal.

  The counter 76 starts counting after initializing the number of pulses to zero at the timing when the home position signal is input from the home position sensor 37. When the counted number of pulses reaches the first count value, the number of pulses is reduced to zero. Initialize and repeat counting again.

  Next, an operation flow of the discharge timing generation unit 58 when a timing signal is output by the discharge timing generation unit 58 according to the third embodiment will be described.

  The line sensor control unit 60 controls the CCD line sensor 36 and performs imaging at predetermined intervals. When the home position sensor 37 detects the above-described home position mark 39, it outputs a home position signal. The counter 76 initializes the number of pulses to zero at the timing when the home position signal is input.

  Here, as shown in FIG. 16, it is assumed that the marks exist at the positions of 200 dots and 6800 dots.

  As shown in (2) of FIG. 16, the first mask processing unit 90A masks data obtained by masking data in a predetermined range (0 to 499 dots) on the upstream side in the transport direction from the data captured by the line sensor control unit 60. Output to the memory 62A. Further, as shown in FIG. 16A, the second mask processing unit 90B masks data in a predetermined range (6500 to 6999 dots) on the downstream side in the transport direction from the data imaged by the line sensor control unit 60. The processed data is output to the memory 62B. That is, two data are created from the data imaged by the CCD line sensor 36.

  The data comparison unit 64A compares the data for two times stored in the memory 62A, and the pulse signal generation unit 66A generates a pulse at a timing at which the comparison result by the data comparison unit 64A does not match the two data. To output a discharge timing signal.

  On the other hand, the data comparison unit 64B compares the data for two times stored in the memory 62B, and the pulse signal generation unit 66B outputs a pulse at a timing at which the comparison result by the data comparison unit 64B does not match the two data. Generate a discharge timing signal.

  In the case of FIG. 16, the selector 70 selects the discharge timing signal input from the pulse signal generation unit 66B and outputs it to the delay processing unit 74, and the delay processing unit 74 outputs each pulse of the input discharge timing signal. Then, the delay time calculated by the delay time calculation unit 72 is delayed, and a discharge timing signal is output to the system bus BUS and the counter 76.

  The counter 76 counts the number of pulses of the ejection timing signal after the home position signal is input, and the mark 38 picked up by the CCD line sensor 36 is rotated in accordance with the circumferential driving on the transport belt 24, and FIG. ), When the number of pulses reaches the third count value (3300 in the present embodiment), the switching instruction signal is output to the selector 70.

  When the switching instruction signal is input from the counter 76, the selector 70 selects the ejection timing signal input from the pulse signal generation unit 66 </ b> A and outputs it to the delay processing unit 74. The delay processing unit 74 performs the same delay processing on each pulse of the input ejection timing signal as before, and outputs the ejection timing signal to the system bus BUS and the counter 76. When the number of pulses is counted for 3300 dots, the data masked by the first mask processing unit 90B (see (3) in FIG. 17A) and the second mask processing unit 90A are used for masking. In the data (see (4) in FIG. 17A), the position of the mark 38 is not misaligned, and the pulse signal generators 66A and 66B each output the ejection timing signal based on the same mark 38. Since it is output, no deviation occurs in the pulse phase of the ejection timing signal. Therefore, it is not necessary to calculate the delay time for switching when the number of pulses is counted for 3300 dots.

  As the counter 76 is driven around the conveyor belt 24, as shown in FIG. 17B, the mark 38 imaged by the CCD line sensor 36 becomes the predetermined range on the downstream side in the conveyance direction of the imaging area, and the next When the mark 38 is imaged in the predetermined range on the upstream side in the conveyance direction of the imaging area and the number of pulses reaches the second count value (6598 in the present embodiment), a delay time calculation instruction signal is output. Thereby, the delay time calculation unit 72 calculates a delay time corresponding to the time difference between pulses of the ejection timing signal input from the pulse signal generation unit 66B with reference to the ejection timing signal input from the pulse signal generation unit 66A.

  Then, as shown in FIG. 16, when the counted number of pulses reaches the first count value (6600 in the present embodiment), the counter 76 outputs a switching instruction signal to the selector 70 and the delay processing unit 74, Initialize the number of pulses.

  When the switching instruction signal is input from the counter 76, the selector 70 switches the output discharge timing signal to output the discharge timing signal input from the pulse signal generation unit 66B.

  When the switching instruction signal is input from the counter 76, the delay processing unit 74 performs a delay process of the delay time t calculated by the delay time calculating unit 72 on each pulse of the discharge timing signal input from the selector 70, and discharges. A timing signal is output to the system bus BUS.

  Note that, as in the second embodiment, the delay processing unit 74 performs the delay processing for the time obtained by accumulating the delay time t calculated by the delay time calculation unit 72, and the pulse of the ejection timing signal When it is longer than the average period T, the same correction is performed.

  As described above, according to the third embodiment, the length of the imaging region of the line sensor with respect to the transport direction is shorter than the length of the recording medium in the transport direction, and one line sensor is provided. The mark is picked up by the line sensor at a predetermined interval with respect to the transport direction and the mark is picked up by the line sensor in the transport direction downstream of the image pickup area of the line sensor. A plurality of markings are added so that the next mark is imaged in a predetermined range on the upstream side in the conveyance direction of the imaging area of the line sensor when passing through a predetermined range on the side, The mask processing unit 90A and the second mask processing unit 90B) obtain data in a predetermined range on the upstream side in the transport direction of the imaging region from the mark position information acquired by the acquisition unit. The generated upstream masked position information and the downstream masked position information obtained by masking a predetermined range of data downstream of the imaging region in the transport direction are generated and generated by a generating unit (here, the pulse signal generating unit 66A). 66B) each time the position of the mark indicated by the upstream masked position information and the downstream masked position information created by the creating means moves by the predetermined amount, the droplet is ejected from the droplet ejection head. Two timing signals indicating the timing of discharging the gas are generated, and the selection unit (here, the selector 70) generates the timing signal generated from the downstream masked position information from the two timing signals generated by the generation unit. Applying a timing signal, the mark position is in the center of the imaging area of the line sensor as the conveyor belt is driven around The timing signal generated from the upstream-side masked position information is applied, and the mark position is set to a predetermined range on the downstream side of the line sensor with respect to the conveyance direction as the conveyance belt rotates. In this case, since the timing signal generated from the downstream-side masked position information generated by imaging the next mark is selected to be applied, the length with respect to the transport direction is the transport direction of the recording medium. The discharge timing signal for recording the image on the recording medium can be generated by one line sensor shorter than the length of the line sensor.

  Further, according to the third embodiment, the calculation means (here, the delay time calculation unit 72) performs imaging of the next mark with reference to the timing signal generated from the upstream masked position information. The delay unit (here, the delay processing unit 74) calculates a delay time based on the phase difference with the timing signal generated from the created downstream masked position information. When a timing signal is selected, delay processing is performed to delay the droplet discharge timing indicated by the timing signal by the delay time calculated by the calculation means. The phase of the discharge timing signal is corrected and becomes the same as the phase of the discharge timing signal before switching, so the recorded image deteriorates. It is possible to prevent that.

  In the first to third embodiments, as shown in FIGS. 17A and 17B, a case where the line sensor is arranged on the same surface as the droplet discharge head with respect to the transport belt will be described. However, the present invention is not limited to this, and for example, marks are provided at predetermined intervals along the transport direction on the back surface, which is the back side of the transport belt facing the droplet discharge head, As shown in FIG. 17C, the line sensor may be arranged on the back surface so as to face the marks on the back surface. Thereby, it is possible to prevent the line sensor from being soiled by the splash of the ink liquid ejected from the droplet ejection head.

  In the first to third embodiments, the case where the mark 38 is attached to the end of the conveyance belt 24 in the width direction has been described. However, the present invention is not limited to this, and the recording paper is attached. Any position may be used as long as it is not to be performed.

  In the first to third embodiments, the case where the CCD line sensor 36 is arranged in parallel with the recording head array 12 in the width direction of the recording paper P of the conveying belt 24 has been described. However, the present invention is not limited to this. However, when the image is recorded on the recording paper, the mark 38 may be arranged at any position as long as it can be imaged. When the extension occurs, the entire length of the conveyor belt 24 becomes longer. By capturing an image of the mark 38, the timing at which the conveyor belt 24 moves by one dot by the circular drive can be detected. You may arrange so that it may line up.

In the second and third embodiments, the predetermined range on the downstream side in the transport direction of the imaging area of the CCD line sensor is 6500 to 6999 dots, and the predetermined range on the upstream side in the transport direction is 0 to 499 dots. However, the present invention is not limited to this, and an appropriate range may be appropriately determined according to the size and interval of the mark 38. In addition, the first to third embodiments The configuration of the ink jet recording apparatus 10 described in the embodiment (see FIGS. 1 to 6, FIGS. 8 to 11, FIGS. 13 to 15, and FIG. 18) is an example, and within the scope not departing from the gist of the present invention. Needless to say, it can be changed as appropriate.

  The inkjet recording apparatus 10 described in the first to third embodiments records an image (including characters) on a recording medium. However, the inkjet recording apparatus 10 of the present invention is limited to this. Is not to be done. That is, the recording medium is not limited to recording paper, and the liquid to be ejected is not limited to ink. For example, the present invention can also be applied to other liquid droplet ejection recording apparatuses such as a pattern forming apparatus that ejects liquid droplets onto a sheet-like substrate for pattern formation of a semiconductor or a liquid crystal display.

1 is a schematic diagram illustrating a configuration of an ink jet recording apparatus according to a first embodiment. It is the schematic which shows the arrangement structure at the time of the maintenance of the inkjet recording device which concerns on 1st Embodiment. FIG. 3 is a perspective view illustrating a detailed configuration of a recording head array and a conveyance belt according to the first embodiment. (A) is a top view of a conveyance belt, (B) is a side view of a conveyance belt. 1 is a block diagram illustrating a configuration of an electrical system of an ink jet recording apparatus according to a first embodiment. It is a block diagram which shows the detailed structure of the discharge timing production | generation part which concerns on 1st Embodiment. It is a figure which shows an example of the data detected by the line sensor which concerns on 1st Embodiment, and a discharge timing signal. FIG. 6 is a perspective view illustrating a detailed configuration of a recording head array and a conveyance belt according to a second embodiment. It is a top view of the conveyance belt which concerns on 2nd Embodiment. It is a block diagram which shows the structure of the electric system of the inkjet recording device which concerns on 2nd Embodiment. It is a block diagram which shows the detailed structure of the discharge timing production | generation part which concerns on 2nd Embodiment. It is a figure which shows the discharge timing pulse signal produced | generated in each process part of the discharge timing production | generation part which concerns on 2nd Embodiment. FIG. 10 is a perspective view illustrating a detailed configuration of a recording head array and a conveyance belt according to a third embodiment. It is a top view of the conveyance belt which concerns on 3rd Embodiment. It is a block diagram which shows the detailed structure of the discharge timing production | generation part which concerns on 3rd Embodiment. It is a schematic diagram which shows an example of the data produced | generated by the line sensor control part 60 which concerns on 3rd Embodiment, a 1st mask process part, and a 2nd mask process part. It is a schematic diagram which shows an example of the data produced | generated by the line sensor control part which concerns on 3rd Embodiment, a 1st mask process part, and a 2nd mask process part. It is a figure which shows the modification of the arrangement position of a line sensor. It is a block diagram which shows the structure of the electric system of the inkjet recording device which concerns on 3rd Embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Inkjet recording device 36 CCD line sensor 58 Discharge timing production | generation part 66, 66A, 66B Pulse signal generation part 70 Selector 72 Delay time calculation part 74 Delay processing part 90A 1st mask processing part 90B 2nd mask processing part P Recording paper

Claims (8)

A droplet discharge recording apparatus for recording an image by discharging droplets from a droplet discharge head to a recording medium being conveyed,
An endless conveyance belt with marks on the non-adsorption region of the recording medium, which is driven in a circle in the conveyance direction with the recording medium adsorbed, and passes the recording medium through an image recording position by the droplet discharge head. When,
A line sensor disposed so that the longitudinal direction of the imaging region coincides with the transport direction and the mark is imaged over the entire longitudinal direction of the imaging region when the transport belt is driven in a circular manner;
Acquisition means for performing imaging by the line sensor every predetermined period, and acquiring mark position information indicating a position of the mark in an imaging region of the line sensor;
Generating means for generating a timing signal used as a timing for discharging a droplet from the droplet discharge head each time the position of the mark indicated by the mark position information acquired by the acquiring means moves by a predetermined amount;
A droplet discharge recording apparatus comprising: The line sensor has the same resolution as the resolution of the image recorded on the recording medium,
The droplet discharge according to claim 1, wherein the generation unit generates a timing signal having a timing at which the position of the mark indicated by the mark position information is shifted by one dot as a timing at which a droplet is discharged from the droplet discharge head. Recording device. The length of the imaging area of the line sensor in the transport direction is longer than the length of the recording medium in the transport direction,
3. The droplet discharge recording apparatus according to claim 1, wherein the conveyance belt is attached to the conveyance belt at an interval in which the mark is longer than the length of the imaging region of the line sensor with respect to the conveyance direction. The length of the imaging area of the line sensor in the transport direction is shorter than the length of the recording medium in the transport direction, and a plurality of the line sensors are provided in parallel along the transport direction.
The conveyor belt is imaged by any one of the line sensors at predetermined intervals with respect to the conveyance direction and with the circumferential driving of the conveyor belt, and the position of the mark is the one of the ones. When passing through a predetermined range on the downstream side in the conveyance direction of the imaging area of the line sensor, a plurality of marks are added so that the next mark is imaged in a predetermined range on the upstream side in the conveyance direction of the imaging area of any one of the other line sensors. And
The acquisition means causes each line sensor to perform imaging at a predetermined cycle, acquires mark position information in the imaging area of each line sensor,
The generation means generates the timing signal for each of the line sensors from the mark position information in the imaging area of each of the line sensors acquired by the acquisition means,
Applying the timing signal of the line sensor obtained by imaging the mark in a predetermined range on the upstream side in the conveying direction of the imaging region from the timing signal for each of the line sensors generated by the generating unit; When the position of the mark becomes a predetermined range on the downstream side in the transport direction of the imaging area of the line sensor in accordance with the rotation driving of the line sensor, the next mark is imaged in the predetermined range on the upstream side in the transport direction of the imaging area. Selection means for selecting to apply the timing signal of the line sensor;
The droplet discharge recording apparatus according to claim 1 or 2, further comprising: Based on the timing signal of the line sensor that images the mark in the predetermined range upstream of the imaging region in the transport direction, the line sensor of the line sensor that images the next mark in the predetermined range upstream of the imaging region in the transport direction Calculating means for calculating a delay time based on the phase difference with the timing signal;
When the timing signal of the next mark is selected by the selection unit, a delay for performing a delay process that delays the timing of ejecting the droplet indicated by the timing signal by the delay time calculated by the calculation unit Means,
The droplet discharge recording apparatus according to claim 4, further comprising: The length of the imaging area of the line sensor in the transport direction is shorter than the length of the recording medium in the transport direction, and one line sensor is provided.
When the mark is imaged by the line sensor at a predetermined interval with respect to the conveyance direction and the mark is imaged by the line sensor, the mark is captured downstream of the imaging area of the line sensor in the conveyance direction. When passing through a predetermined range on the side, a plurality of marks are attached so that the next mark is imaged in a predetermined range on the upstream side in the transport direction of the imaging region of the line sensor,
Upstream masked position information obtained by masking data in a predetermined range on the upstream side in the transport direction of the imaging region from the mark position information acquired by the acquisition unit, and data on a predetermined range on the downstream side in the transport direction of the imaging region Further comprising a creation means for creating downstream masked position information masked with
Each time the generating unit moves the predetermined position indicated by the upstream masked position information and the downstream masked position information created by the creating unit from the droplet discharge head, Generating two timing signals indicating the timing of discharging
The timing signal generated from the downstream-side masked position information is applied from the two timing signals generated by the generation unit, and the position of the mark is imaged by the line sensor as the conveyor belt rotates. The timing signal generated from the upstream-side masked position information is applied when the area becomes the central portion of the area, and the mark position is downstream in the conveyance direction of the line sensor as the conveyance belt rotates. A selection means for selecting to apply the timing signal generated from the downstream masked position information generated by imaging the next mark when the predetermined range is reached,
The droplet discharge recording apparatus according to claim 1. Based on the timing signal generated from the upstream masked position information as a reference, a delay time based on the phase difference from the timing signal generated from the downstream masked position information generated by imaging the next mark A calculating means for calculating;
When the timing signal of the next mark is selected by the selection unit, a delay for performing a delay process that delays the timing of ejecting the droplet indicated by the timing signal by the delay time calculated by the calculation unit Means,
The droplet discharge recording apparatus according to claim 6, further comprising: The transport belt is attached to the back surface, which is the back side of the mark facing the droplet discharge head with respect to the transport belt,
The liquid droplet ejection recording apparatus according to claim 1, wherein the line sensor is disposed on the back surface side so as to image the mark attached to the back surface.

Images