JP2010234773A - Line type inkjet recorder, method for adjusting line type inkjet recorder, and inkjet recording method by line type inkjet recorder - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a new technique capable of obtaining the same excellent recording quality in the overlapped part of nozzles formed at the end of a recording head as that in the other parts. <P>SOLUTION: A test image based on a plurality of test pattern information pieces is recorded on a roll sheet of paper by one recording operation (S102) and read by a CCD camera (S104). Each test pattern image included in the test image read by the CCD camera is analyzed to select specific test pattern information suitable for each nozzle overlapped part (S106 and S108: No) and pattern constituting information coincident with the selected specific test pattern information is stored in a non-volatile memory (S110). <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a line type ink jet recording apparatus.

  In recent years, an ink jet recording apparatus is known as an apparatus for recording on a recording medium. The ink jet recording apparatus performs recording by ejecting ink from nozzles formed on a recording head, and has an advantage that a high-precision image can be easily recorded at a high speed. There is a type of ink jet recording apparatus called a line type ink jet recording apparatus. Various technologies have been proposed for line-type inkjet recording apparatuses. For example, a recording head unit arranged so as to have an overlapping area between the heads, a predetermined test chart is printed using the recording head unit, and the overlapping area of each of the plurality of recording heads is printed from the printed test chart. Image formation having an arrangement angle / overlap area detection unit for detecting the width and an image data distribution unit for distributing image data input to each of the plurality of recording heads according to the width of the overlap area between the detected heads A device has been proposed. According to this image forming apparatus, it is said that there is an effect that density unevenness in the overlapping region of the heads can be eliminated only by rough head alignment (for example, Patent Document 1).

  In addition to the line type, the inkjet recording apparatus includes a scanning type inkjet recording apparatus different from this, and various techniques have been proposed for this (for example, Patent Document 2).

Table 2002/062581 JP 2001-1510 A

  By the way, when a line type recording head unit is configured by combining a plurality of recording heads, more specifically, a plurality of recording heads are arranged so that the nozzles formed at the ends of the recording heads overlap on the same line. In this case, the position of each recording head needs to be adjusted appropriately. However, it is difficult to completely adjust the position of each recording head. Even if high-precision alignment can be realized, if the dimensional accuracy of the recording head manufactured by a predetermined processing method is poor, for example, with respect to the nozzle formation position, the overlapping nozzles are on the same straight line. It is never placed. It is practically impossible to produce a plurality of completely identical recording heads. Therefore, it is necessary to compensate for the positional deviation of the recording head by any method.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a new technique that can make the recording quality in an overlapping portion of nozzles formed at the end of a recording head excellent in recording quality similar to other portions.

  The present invention has been made in view of the above problems, and each recording head in which a nozzle row in which a plurality of nozzles are arranged is formed in a direction orthogonal to a conveyance direction of a recording medium on which a recording image indicated by image data is recorded. In connection with a line-type inkjet recording apparatus comprising a recording head unit arranged such that a nozzle at one end of the recording head and a nozzle at the other end of the recording head overlap in the transport direction, The test image including the test pattern image is recorded, each test pattern image included in the recorded test image is analyzed, test pattern information of the test pattern image satisfying a predetermined condition is selected, and input from an external device When the recorded image data is recorded, the ejection of ink droplets corresponding to the selected test pattern information is controlled.

  The first problem-solving means that reflects the present invention includes a plurality of nozzles in a direction orthogonal to a conveyance direction in which a recording medium on which a recording image indicated by image data input from an external device is recorded is conveyed. A recording head in which each recording head formed with an array of arranged nozzle rows is arranged such that a nozzle at one end of the recording head and a nozzle at the other end of the recording head overlap in the transport direction. A line-type inkjet recording apparatus comprising a unit, wherein when ink droplets are ejected from the nozzle row to record a test pattern image, whether or not ink droplets are ejected from the nozzles on the one side end, and A storage unit for storing a plurality of test pattern information including information on whether or not ink droplets are ejected from the nozzles on the other side end, and nozzles on the one side end For the ejection of ink droplets and the ejection of ink droplets from the nozzles on the other side end, ejection is performed according to each of the plurality of test pattern information stored in the storage unit, and the nozzles on the one side end and the other side For the ejection of ink droplets from nozzles other than the nozzles at the end, the test pattern is ejected together with the ejection of ink droplets from the nozzle at the one side end or the ink droplets from the nozzle at the other end. A test pattern recording unit for controlling recording of a single test image including each test pattern image corresponding to each piece of information, a reading unit for reading the test image, and each test included in the test image read by the reading unit An analysis unit that analyzes the pattern image and a specific test that satisfies a predetermined condition based on the analysis result of each test pattern image by the analysis unit. A selection unit that selects test pattern information of a pattern image as specific test pattern information, and the one side corresponding to the specific test pattern information selected by the selection unit when the recording image is recorded on the recording medium An ink jet recording apparatus comprising: an image data recording unit that controls ejection of ink droplets from a nozzle at an end and ejection of ink droplets from a nozzle at the other end.

  According to this, a single test image including each test pattern image corresponding to each of the plurality of test pattern information stored in the storage unit is recorded, and by analyzing the test image, in the conveyance direction of the recording medium One specific test pattern information can be selected for the ejection of ink droplets from the nozzles at one end and the other end arranged so as to overlap. In addition, when recording image data, it is possible to realize suitable ink droplet ejection corresponding to the selected specific test pattern information.

  A second problem solving means is the ink jet recording apparatus according to the first problem solving means, wherein the test pattern image includes dots formed by ink droplets ejected from the nozzles of the nozzle row in a predetermined direction in the transport direction. It is an image formed by several consecutive dot rows, and the analysis unit includes a nozzle at the one side end for a nozzle row including the nozzle at the one side end for each test pattern image included in the test image. First dot row analysis information corresponding to each of the dot rows by each of the other nozzles and each of the dot rows by each of the nozzles other than the nozzles at the other end of the nozzle row including the nozzles at the other end. And the second dot row analysis information is obtained using each of the obtained first dot row analysis information, and the test included in the test image is further acquired. For each pattern image, third dot row analysis information corresponding to a dot row by the nozzle at the one side end and the nozzle at the other end is acquired, and the selection unit includes a test pattern included in the test image. For each image, the second dot row analysis information and the third dot row analysis information are compared, and the test pattern of the test pattern image in which the second dot row analysis information and the third dot row analysis information are closest to each other Information is selected as the specific test pattern information.

  According to this, it is possible to select suitable specific test pattern information in consideration of the entire test pattern image.

  The third problem solving means is the ink jet recording apparatus of the second problem solving means, wherein each of the plurality of test pattern information stored in the storage unit is given a priority, and the selection unit is When a plurality of test pattern information of the closest test pattern image is extracted as a result of comparing the second dot row analysis information and the third dot row analysis information for each test pattern image included in the test image The specific test pattern information is selected according to the priority order.

  According to this, one suitable specific test pattern information can be selected according to the priority order.

  The fourth problem solving means is an ink jet recording apparatus according to any one of the first to third problem solving means, wherein a maintenance station for recording the test image, the recording head unit, and the maintenance station The test pattern recording unit controls the movement of the recording head to the maintenance station by the moving unit, and the recording head unit is moved to the maintenance station, In addition to controlling the recording of the test image, the reading unit is installed in the maintenance station and reads the test image recorded in a state where the recording head unit is moved to the maintenance station.

  According to this, a test image can be recorded at the maintenance station.

  According to a fifth problem solving means, a nozzle array in which a plurality of nozzles are arranged in a direction orthogonal to a conveyance direction in which a recording medium on which a recording image indicated by image data input from an external device is recorded is conveyed. A recording head unit in which each formed recording head is arranged so that a nozzle at one end of the recording head and a nozzle at the other end of the recording head overlap in the transport direction, In the case of recording a test pattern image by ejecting ink droplets from a nozzle row, whether or not ink droplets are ejected from the nozzles on the one side end portion and whether or not ink droplets are ejected from the nozzles on the other side end portion A plurality of test pattern information including information related to the ink droplets, and ejection of ink droplets from the nozzles on the one side end and nozzles on the other side end corresponding to the specific test pattern information. A line-type ink jet recording apparatus capable of controlling the discharge of ink droplets from a recording medium and recording the recorded image on the recording medium, wherein the ink droplets are discharged from the nozzles at the one end. For ejection of ink droplets from the nozzle on the other side end, ejection is performed in accordance with each of a plurality of test pattern information stored in the storage unit, and the nozzles other than the nozzle on the one side end and the nozzle on the other side end For the ejection of ink droplets from the nozzles of the nozzles, the ink droplets are ejected from the nozzles at the one side end portions or the ink droplets from the nozzles at the other side end portions. A test pattern recording process for controlling the recording of a single test image including each pattern image, a reading process for reading the test image, and the reading process. From the analysis step of analyzing each test pattern image included in the test image read in the above, and the analysis result of each test pattern image by the analysis step, the test pattern information of the test pattern image that satisfies a predetermined condition, And a selection step of selecting as specific test pattern information.

  According to this, a single test image including each test pattern image corresponding to each of the plurality of test pattern information stored in the storage unit is recorded, and by analyzing the test image, in the conveyance direction of the recording medium Suitable specific test pattern information can be selected for the ejection of ink droplets from the nozzles at one end and the other end arranged so as to overlap.

  According to a sixth problem solving means, a nozzle array in which a plurality of nozzles are arranged in a direction orthogonal to a conveyance direction in which a recording medium on which a recording image indicated by image data input from an external device is recorded is conveyed. A recording head unit in which each formed recording head is arranged so that a nozzle at one end of the recording head and a nozzle at the other end of the recording head overlap in the transport direction; and the nozzle In the case of recording a test pattern image by ejecting ink droplets from a row, whether or not ink droplets are ejected from the nozzles on the one side end, and whether or not ink droplets are ejected from the nozzles on the other end And a storage unit that stores a plurality of test pattern information including information on the ink jet recording method using a line type ink jet recording apparatus, The ink droplets discharged from the nozzles and the ink droplets discharged from the nozzles on the other side end according to each of a plurality of test pattern information stored in the storage unit, And discharging ink droplets from nozzles other than the nozzles on the other side end, together with discharging ink droplets from the nozzle on the one side end or discharging ink droplets from the nozzle on the other side end, Included in the test pattern recording step for controlling the recording of a single test image including each test pattern image corresponding to each of the test pattern information, the reading step for reading the test image, and the test image read by the reading step From the analysis step of analyzing each test pattern image to be analyzed and the analysis result of each test pattern image in the analysis step, A selection step of selecting test pattern information of the test pattern image satisfying the condition as specific test pattern information, and ink from the nozzle on the one side end corresponding to the specific test pattern information selected by the selection step An ink-jet recording method comprising: an image data recording step of controlling droplet ejection and ejection of an ink droplet from a nozzle at the other end, and recording the recorded image on the recording medium. .

  According to this, a single test image including each test pattern image corresponding to each of the plurality of test pattern information stored in the storage unit is recorded, and by analyzing the test image, in the conveyance direction of the recording medium One specific test pattern information can be selected for the ejection of ink droplets from the nozzles at one end and the other end arranged so as to overlap. In addition, when recording image data, it is possible to realize suitable ink droplet ejection corresponding to the selected specific test pattern information.

  According to the present invention, it is possible to obtain a new technique capable of making the recording quality in the overlapping portion of the nozzles formed at the end of the recording head the same as the other recording portions.

Diagram showing inkjet recording apparatus Diagram showing recording head unit Diagram showing test pattern information The figure which shows the test pattern image based on the test pattern information by the pattern A Figure showing a test image The figure which shows the flow of test pattern information selection processing Diagram explaining the maximum width of a dot row Diagram showing the relationship between the recording head mounting position and the test image Diagram showing the relationship between the recording head mounting position and the test image Diagram showing the relationship between the recording head mounting position and the test image Diagram showing the relationship between the recording head mounting position and the test image Diagram explaining adjustment of maximum width of dot row

  Embodiments for implementing the above problem solving means reflecting the present invention will be described below in detail with reference to the drawings. The above-mentioned problem solving means is not limited to the configuration described below, and various configurations can be adopted in the same technical idea. For example, in each configuration described below, a predetermined configuration can be omitted.

(Outline of inkjet recording apparatus)
The ink jet recording apparatus 100 will be described with reference to FIG. The ink jet recording apparatus 100 is a line type ink jet recording apparatus. The ink jet recording apparatus 100 includes an electrical box 200, a belt conveyor 300, a carriage 400, and a maintenance station 500. The ink jet recording apparatus 100 includes a main tank that stores ink used for image recording (not shown in FIG. 1). The ink jet recording apparatus 100 is provided with a main tank that stores predetermined ink for the ink colors used in the ink jet recording apparatus 100. For example, the inkjet recording apparatus 100 includes a main tank that stores inks of cyan, magenta, yellow, and black (blacK). The ink jet recording apparatus 100 can record a color image on a cloth or other recording medium conveyed by a belt conveyor 300 described later using each color ink.

  The electrical box 200 is a device (box) in which a circuit board on which various electrical components or electronic components are placed is stored. The electrical box 200 includes, for example, a control unit, a nonvolatile memory (EEPROM), and an external device interface. The control unit controls the inkjet recording apparatus 100. The control unit includes, for example, a CPU, a ROM, and a RAM. The CPU executes various arithmetic processes. The ROM stores a program for each process executed in the inkjet recording apparatus 100. The RAM is a work area when the CPU executes a program stored in the ROM.

  The control unit executes a test pattern information selection process (see FIG. 5) described later. The control unit controls reception of image data transmitted from an external device such as a personal computer connected via the external device interface. Then, the control unit performs a thinning process (mask process) on the raster image generated from the received image data. At this time, the control unit executes the thinning process according to the pattern configuration information registered (stored) in the nonvolatile memory in S110 (see FIG. 6) of the test pattern selection process described later. The nonvolatile memory stores a plurality of test pattern information described later (see FIG. 3).

  The electrical box 200 also includes devices provided in the inkjet recording apparatus 100, such as a belt conveyor 300, a CCD camera 540, and a connection interface with each moving mechanism. The control unit also controls each of these devices connected via this connection interface.

  The belt conveyor 300 is a device that conveys a recording medium 320 on which a recorded image indicated by image data transmitted from an external device is recorded. Specifically, the recording medium 320 stacked on the belt conveyor 300 is transported directly below the carriage 400, and then the recording medium 320 is transported to a predetermined position where the recording medium 320 on which the recorded image is recorded is removed.

  The carriage 400 includes a recording head unit 420 that discharges ink supplied from a main tank (not shown in FIG. 1). The recording head unit 420 discharges the ink supplied from the main tank to the recording medium 320 conveyed just below the carriage 400. The recording head unit 420 will be described with reference to FIG. The recording head unit 420 includes a plurality of recording heads 422-1 to 422-4. Hereinafter, the recording heads 422-1 to 422-4 are collectively referred to as the recording head 422.

  The recording head 422 includes a first nozzle row 426A in which nozzles 424A at one end of the recording head 422 are arranged in a direction perpendicular to the conveyance direction of the recording medium 320, and the other end of the recording head 422. A second nozzle row 426B in which nozzles 424B are arranged is formed. Hereinafter, the first nozzle row 426A and the second nozzle row 426B are also collectively referred to as a nozzle row 426.

  As is clear from FIG. 2, the nozzles 424 forming the first nozzle row 426A and the nozzles 424 forming the second nozzle row 426B are arranged in a staggered manner. Further, in the recording heads 422-1 and 422-2, the nozzle 424B at the other end of the recording head 422-1 and the nozzle 424A at the one end of the recording head 422-2 overlap in the transport direction. Is arranged. The recording head 422-2 is further arranged so that the nozzle 424B at the other end of the recording head 422-2 and the nozzle 424A at the one end of the recording head 422-3 overlap in the transport direction. Yes. Similarly, the position of the recording head 422-3 is adjusted with the recording head 422-4.

  In the recording head 422 shown in FIG. 2, two nozzle rows 426 are formed by four nozzles 424. However, actually, each nozzle row 426 is formed by a larger number (for example, 48) of nozzles 424. Further, the recording head unit 420 shown in FIG. 2 includes four recording heads 422, but actually, a plurality of recording heads 422 are arranged in the manner shown in FIG.

  Returning to FIG. 1, for example, the maintenance station 500 mounts the recording head unit 420 on the carriage 400 or replaces the recording head unit 420 already mounted with another recording head unit 420 (recording head 422). And an area for recording a test image including a plurality of test pattern images (patterns X, A to H / see FIG. 3) to be described later. The maintenance station 500 includes a roll paper 520 and a CCD camera 540. A test image is recorded on the roll paper 520. The CCD camera 540 is a line type CCD camera.

  When recording a test image, each unit operates (moves) as follows. First, the carriage 400 moves to the maintenance station 500 by a predetermined moving mechanism (see arrow “1” in FIG. 1). Next, roll paper 520 is supplied (conveyed) (see arrow “2” in FIG. 1). When the roll paper 520 is supplied directly under the carriage 400, a test image including a plurality of test pattern images is recorded. Thereafter, the roll paper 520 is further conveyed to the CCD camera 540 side. Then, the test image recorded on the conveyed roll paper 520 is read by the CCD camera 540. When reading the test image, the CCD camera 540 scans in the width direction of the roll paper 520 (see arrow “3” in FIG. 1). After the test image is read by the CCD camera 540, the roll paper 520 is wound by a winding mechanism not shown in FIG. Further, after recording the test image, the carriage 400 moves to an image recording position (a position in FIG. 1 where the carriage 400 is shown) (see arrow “1” in FIG. 1).

  The test image is recorded when the recording head unit 420 (recording head 422) is replaced in the carriage 400 or the like (for example, adjustment between the recording heads 422-1 and 422-2). To be implemented. Details of this will be described in a test pattern information selection process (see FIG. 6) described later.

(Test pattern information)
A plurality of pieces of test pattern information used for recording a test image will be described with reference to FIG. 3 corresponds to the recording head 422-1. Hereinafter, the “recording head 2” is the recording head 422-2, the “recording head 3” is the recording head 422-3, and the “recording head 422-3”. The recording head 4 ”corresponds to the recording head 422-4. The test pattern information includes whether or not ink droplets are ejected from the nozzle 424A at one end of the recording head 422 and the nozzle 424B at the other end when recording each test pattern image included in the test image. Information including whether or not ink droplets are ejected.

  The test pattern information will be described by taking the pattern A based on the recording heads 422-1 and 422-2 as an example. First, the recording head 422-1 (the nozzle 424B at the other end of the recording head 422-1; hereinafter the same) ejects ink to the pixels in the first row in the transport direction (pattern A in FIG. 3). Is registered in the left field of the recording head 1). In contrast, the recording head 422-2 (nozzle 424A at one end of the recording head 422-2, hereinafter the same) does not eject ink (the pattern A in FIG. × ”is registered).

  For the pixels in the second row, the recording head 422-1 does not eject ink (“X” is registered in the second field on the left side of the recording head 1 for the pattern A in FIG. 3). On the other hand, the recording head 422-2 discharges ink (“◯” is registered in the second field on the left side of the recording head 2 for the pattern A in FIG. 3).

  For the pixels in the third row, the recording head 422-1 ejects ink (“O” is registered in the third field on the left side of the recording head 1 for pattern A in FIG. 3), and the recording head 422-2. Does not eject ink (“X” is registered in the second field on the left side of the recording head 2 for the pattern A in FIG. 3).

  For the pixels in the fourth row, the recording head 422-1 does not eject ink (“X” is registered in the right field of the recording head 1 for the pattern A in FIG. 3), while the recording head 422-2 is Ink is ejected (“O” is registered in the right field of the recording head 2 for the pattern A in FIG. 3). Note that such ink ejection is realized when the control unit executes a thinning process based on the test pattern information on the raster image indicating the test image including the test pattern image.

  No test pattern information is registered for nozzles 424 that do not overlap. Therefore, ink is ejected to all corresponding pixels in accordance with raster data (data indicating a test image) developed on the RAM.

  FIG. 4 shows a test pattern image based on the pattern A thus formed. 4 shows an upper side of the test pattern image formed by the recording heads 422-1 and 422-2 from the nozzle 424B at the other end of the recording head 422-1 (the upper side when FIG. 2 is viewed from the front). ) A test pattern image in a range recorded by two nozzles 424 and two nozzles 424 below the nozzle 424A at the one end portion of the recording head 422-2 (lower side when FIG. 2 is faced). Indicates. Also, “first line” to “fourth line” shown in FIG. 4 correspond to “first line” to “fourth line” shown in FIG.

  The test pattern image is formed by a dot row in which four dots are arranged in the transport direction. The nozzle 424B at the other end of the recording head 422-1 and the nozzle 424A at one end of the recording head 422-2 (hereinafter, the combination of the nozzle 424A at one end and the nozzle 424B at the other end is referred to as “nozzle”). The dot row (also referred to as “overlap portion dot row” in FIG. 4) of both nozzles of “overlapping portion”) is an array of dots corresponding to the test pattern information of the pattern A in FIG. In the following, a dot row formed by overlapping nozzle portions is referred to as an “overlapping portion dot row”, and other dot rows are also referred to as “single portion dot rows”.

  Returning to FIG. 3, a priority is assigned to each test pattern information. The priority order is determined according to a predetermined rule. In other words, the same nozzle 424, specifically, a pattern in which dots by the nozzle 424A at the one side end are continuous or a pattern in which the dots by the nozzle 424B at the other end are continuous, has a lower priority. ing. In other words, the pattern in which the dots formed by the nozzle 424A at the one end and the dots formed by the nozzle 424B at the other end are mixed has a high priority. This is based on the fact that the quality of the dots becomes obvious when dots due to ink droplets ejected from the same nozzle are continuous. According to the pattern X, ink droplets are ejected from both the nozzle 424A at one end and the nozzle 424B at the other end with respect to one pixel. Therefore, the priority order of the pattern X is set to the lowest.

  The configuration ratio shown in FIG. 3 indicates the ratio of ejection from the nozzle 424A at one end and the nozzle 424B at the other end. In the above-mentioned pattern A, two dots are formed by the ink droplets ejected from the nozzle 424B at the other end of the recording head 422-1 in the dot row formed by four dots, and the recording head 422- Since there are also two dots formed by the ink droplets ejected from the nozzle 424A at the one end on the two sides, the composition ratio is “50% (2/4)” and {50% (2/4) " The composition ratio does not particularly constitute test pattern information.

(Test pattern information selection process)
Test pattern information selection processing executed by the control unit in the electrical box 200 will be described with reference to FIG. This process is executed when the recording head unit 420 included in the carriage 400 is replaced. When executing this process, the user operates the operation unit of the inkjet recording apparatus 100 and inputs an instruction to start this process. The control unit that has acquired the start instruction reads the program for this processing from the ROM that constitutes the control unit, and executes this program on the RAM.

  The control unit that has started this process first controls a predetermined moving mechanism (moving unit) to move the carriage 400 to the maintenance station 500 (see S100 / arrow “1” in FIG. 1). The control unit that has acquired a signal indicating that the carriage 400 has moved to the maintenance station 500 from a sensor (not shown in FIG. 1) installed in the maintenance station 500 starts supplying the roll paper 520 to the carriage 400 side. (See arrow “2” in FIG. 1). Then, the control unit records a test image on the roll paper 520 supplied immediately below the carriage 400 (S102).

  In S102, the control unit generates raster data indicating a test image including a plurality of test pattern images based on predetermined data stored in, for example, a nonvolatile memory, and develops the raster data on the RAM. Subsequently, the control unit performs a thinning process based on the test pattern information (see FIG. 3) of each pattern on the raster data developed on the RAM, and records a test image on the roll paper 520. Ink is ejected from each nozzle 424 of the recording head 422 at a timing based on the thinning process. That is, ejection and non-ejection of ink droplets are controlled according to each test pattern information at the nozzle 424A at the one end of the recording head 422 or the nozzle 424B at the other end. Further, the ejection of continuous ink droplets is controlled by the nozzles 424 other than the nozzle 424A at one end or the nozzle 424B at the other end.

  The test image recorded on the roll paper 520 in S102 includes all the test pattern images for the pattern X and the patterns A to H recorded by the recording heads 422-1 to 422-4. That is, the control unit records a test image including all test pattern images based on the test pattern information stored in the nonvolatile memory on the roll paper 520 by recording the test image once. In FIG. 6, illustration of dots forming each test pattern image is omitted.

  The control unit that executed S102 reads the test image recorded on the roll paper 520 with the CCD camera 540 (S104). When reading a test image, the control unit controls a predetermined moving mechanism to move the CCD camera 540 (see arrow “3” in FIG. 1). Then, the control unit analyzes each test pattern image included in the test image read by the CCD camera 540 in S102, and selects suitable specific test pattern information (S106).

  In S106, the control unit first calculates the occupation area for each dot row by a single nozzle and each dot row by an overlapping portion. Specifically, the number of pixels occupied by each dot row in the image read by the CCD camera 540 is counted, and the counted value is defined as the area. Next, the control unit calculates the maximum width of each dot row. Here, the maximum width is as shown in FIG. That is, in a dot row in which dots are formed on a straight line, the maximum width is approximately equal to the dot diameter (see FIG. 7A). On the other hand, when the dots formed by the nozzle 424A on the one side end and the dots formed by the nozzle 424B on the other side end are formed on different straight lines in the overlapping dot row, the maximum width is shifted to the dot diameter. It is approximately equal to the width obtained by adding the quantities (see FIG. 7B).

  The control unit calculates an average value of the area occupied by the single-part dot row for each test pattern image included in the test image, with two adjacent recording heads 422 as one unit. For example, the control unit obtains the total occupied area of the single-part dot rows of the recording heads 422-1 and 422-2 for each test pattern image, and the total number of single-part dot rows of the recording heads 422-1 and 422-2. (For example, “7 (column)” based on the recording head 422 shown in FIG. 2. The same applies hereinafter).

  Note that when the target of S106 is the recording heads 422-2 and 422-3 (see S108, which will be described later), the control unit performs the single part dot of the recording heads 422-2 and 422-3 for each test pattern image. The total occupied area of the columns is obtained and divided by the total number of single dot rows of the recording heads 422-2 and 422-3. Further, when the target of S106 is the recording heads 422-3 and 422-4, the control unit obtains the total occupied area of the single dot rows of the recording heads 422-3 and 422-4 for each test pattern image. Divide by the total number of individual dot rows of the recording heads 422-3 and 422-4.

  Further, the control unit calculates the average value of the maximum widths of the single-part dot rows for each adjacent recording head 422. The average value calculation of the maximum width is performed by a method similar to the calculation of the average value of the occupied area described above. Details are omitted.

  Then, the control unit uses the two adjacent recording heads 422 as one unit, and compares the average value of the occupied area and the occupied area of the overlapping dot row for each test pattern image included in the test image, The average value of the maximum width is compared with the maximum width of the overlapping dot row. For example, the absolute value of the difference between the occupied areas and the absolute value of the difference between the maximum widths are calculated. Then, as a result of the comparison, the control unit specifies a test pattern image in which the overlapping portion dot row that is closest to the average value of the occupied area and the maximum width is identified, and extracts the test pattern information of the specified test pattern image . Here, when a plurality of test pattern images that form the closest overlapping portion dot row are identified and a plurality of test pattern information are extracted along with this, the control unit extracts test pattern information having a higher priority ( (See FIG. 3 for priorities). And a control part selects the extracted test pattern information as suitable specific test pattern information regarding the nozzle overlap part of analysis object, for example, the nozzle overlap part of the recording heads 422-1 and 422-2.

  Subsequently, the control unit that has executed S106 determines whether or not the process of S106 has been completed for all nozzle overlapping portions (S108). For example, when the process of S106 is performed for the nozzle overlapping portions of the recording heads 422-1 and 422-2, the combination of the recording heads 422-2 and 422-3, the recording heads 422-3 and 422-4 S106 is sequentially executed for the combinations.

  When the determination in S108 is negative (S108: No), the control unit returns the process to S106 and executes the same process as described above. On the other hand, if the determination in S108 is affirmative (S108: Yes), the control unit shifts the process to S110. In S110, the control unit registers (stores) the pattern configuration information that matches the specific test pattern information selected in S106 in association with the corresponding nozzle overlap portion. The pattern configuration information registered in S110 is used when image data transmitted from an external device is received and thinning processing (mask processing) is performed on a raster image generated from the received image data. .

  For example, the control unit registers pattern configuration information that matches the specific test pattern information based on the pattern A in the nonvolatile memory for the combination with the recording heads 422-1 and 422-2. In addition, the control unit registers pattern configuration information that matches the specific test pattern information based on the pattern B for the combination of the recording heads 422-2 and 422-3. Further, the control unit registers pattern configuration information that matches the specific test pattern information based on the pattern C for the combination of the recording heads 422-3 and 422-4.

(Relationship between mounting position of recording head and test image)
The relationship between the mounting position of the recording head 422 and the test image will be described with reference to FIGS. In the following description, the recording heads 422-1 and 422-2 will be described as an example as described above. The two-dot chain lines shown in FIGS. 8 to 11 are virtual straight lines, and the width between the two two-dot chain lines corresponds to the maximum width.

  First, when the positional relationship between the nozzle 424B at the other end of the recording head 422-1 and the nozzle 424A at the one end of the recording head 422-2 is set appropriately (see FIG. 8), the one end The dots are formed so as to coincide with the positions of the nozzle 424A and the nozzle 424B at the other end. In this case, in all patterns including the pattern A and the pattern B, the same overlapping dot row is formed in appearance. In S106 of the test pattern selection process shown in FIG. 6, the control unit selects the test pattern information of pattern A as the specific test pattern information according to the priority order of the test pattern information.

  On the other hand, when the recording head 422-1 is attached to the recording head 422-1 side (the nozzle 424A side at one end of the recording head 422-1) with reference to the recording head 422-1 (FIG. 9). Reference), dots formed by ink droplets ejected from the nozzle 424A at one end of the recording head 422-2 are formed shifted to the recording head 422-1 side. In this case, overlapping portion dot rows by the pattern A are recorded in a discontinuous state, in other words, in a staggered manner. In addition, the overlapping dot row by the pattern B is formed shifted to the recording head 422-1 side in the third row.

  Similarly, when the recording head 422-2 is attached to the recording head 422-3 side (see FIG. 2 for the recording head 422-3) with reference to the recording head 422-1 (see FIG. 10), the recording head 422 is used. -2 dots formed by the ink droplets ejected from the nozzle 424A at one side end are shifted to the recording head 422-3 side. Also in this case, the overlapping dot rows by the pattern A are recorded in a discontinuous staggered pattern. However, as compared with the case of FIG. 9, the shape is shifted to the opposite side with respect to the arrangement direction of the overlapping dot rows. In addition, the overlapping dot row by the pattern B is formed shifted to the recording head 422-3 side in the third row.

  In the example shown in FIG. 11, the recording head 422-2 is attached to the recording head 422-3 side (see FIG. 2 for the recording head 422-3) with a considerable amount of displacement with respect to the recording head 422-1. Is based. The dots recorded on the roll paper 520 in such a state form a streamline extending toward the subsequent dots.

  By the way, when the ink droplets ejected from the nozzle 424 are recorded (landed) on the roll paper 520, the roll paper 520 supplied immediately below the carriage 400 is in a moving state. Ink droplets that have landed on the recording surface of the roll paper 520 in such a state are recorded at the landing position, while a portion of the ink that forms the ink droplets is recorded on the side opposite to the moving direction. For example, any dot such as each dot in the overlapping part dot row shown in FIG. 8 or each dot in the single part dot row has a streamline shape as shown in FIG. When the ink droplet lands on the subsequent position, the new ink droplet lands on the streamline portion of the dot that has landed immediately before. Therefore, the streamlined portion overlaps the dot by the next ink droplet, and the streamlined portion is canceled.

  However, as shown in FIG. 11, when the positions of the recording heads 422-1 and 422-2 are shifted by a considerable amount, the landing positions of the ink droplets that land in sequence are changed from the streamline portion of the ink droplets that landed immediately before. Misaligned and streamlined dots are recorded discontinuously on the roll paper 520. Regarding S106 of the test pattern information selection process shown in FIG. 6, in the case of FIG. 11, the maximum width is substantially the same for all patterns including patterns A and B. However, the occupied area is smaller in the pattern in which the ratio of ejection from the same nozzle is high, in other words, in the pattern in which the composition ratio is biased in one of the nozzles. When pattern A and pattern B are compared, the area occupied by overlapping dot rows by pattern B is small.

  Here, based on the above, the relationship between the overlapping area and the maximum width of the overlapped dot row will be described. There is a fixed relationship between the two, and the wider the maximum width, the larger the occupied area (the smaller the maximum width, the smaller the occupied area. Narrowed). In other words, when the occupied area is wide, the maximum width is also widened (when the occupied area is small, the maximum width is also narrowed). This is based on whether the streamlined part is canceled.

  Note that the streamlined portion is recorded on the recording surface of the roll paper 520 for the dots in the overlapping portion dot row described in FIGS. However, illustration of this is omitted in FIGS. 9 and 10.

(Advantageous effects based on the configuration of the present embodiment)
According to the ink jet recording apparatus 100 of the present embodiment, the following advantageous effects can be obtained.

  (1) In the inkjet recording apparatus 100, in the maintenance station 500 for mounting the recording head unit 420 on the carriage 400 or replacing the already mounted recording head unit 420 with another recording head unit 420 (recording head 422). The test image was recorded. According to this, it is not necessary to move the carriage 400 to which the recording head unit 420 is newly attached onto the belt conveyor 300 during the mounting operation of the recording head unit 420 to record a test image. And the subsequent adjustment (test pattern information selection process) can be performed efficiently.

  (2) In the inkjet recording apparatus 100, a test image based on a plurality of test pattern information is recorded on the roll paper 520 by one recording operation (see S102 in FIG. 6), and is read by the CCD camera 540 (FIG. 6). S104), analysis is performed, and suitable specific test pattern information is selected for each nozzle overlapping portion (S106, S108: No in FIG. 6). According to this, when selecting suitable specific test pattern information for each nozzle overlapping portion, it is not necessary to sequentially record test pattern images based on each test pattern information, and the processing efficiency can be improved.

  (3) In the inkjet recording apparatus 100, when selecting suitable specific test pattern information for each nozzle overlapping portion (see S106 in FIG. 6), the average value of the area occupied by the single portion dot row and the average value of the maximum width, The specific test pattern information is selected in comparison with the occupied area and the maximum width of the overlapping portion dot row. According to this, the inkjet recording apparatus 100 can be set so that the overlapping part dot row approximate to the state of the single part dot row is recorded.

  In addition, when forming the dots of the overlapping portion dot line on a straight line, it is possible to adopt a configuration in which only the overlapping dot line is focused and test pattern information having a minimum value such as the maximum width is selected. However, if there is a shift amount (see FIG. 7B) in the single dot row for some reason, there is a shift in the overlapping dot row portion formed on a straight line in the entire recorded image. It is visually recognized. In this respect, the configuration of S106 (see FIG. 6) of the present embodiment is preferable in this respect.

(Modification)
(1) In the above description, the configuration in which the belt conveyor 300 is employed for transporting the recording medium 320 has been described as an example. However, other configurations are possible. For example, it can also be set as the structure by a roller conveyor.

  (2) In the above description, the configuration in which the test image is recorded on the roll paper 520 has been described as an example. In addition to the roll paper 520, a test image may be recorded on a material such as glass or plastic. In this case, after the test image is read by the CCD camera 540, a wiping mechanism that can wipe off the test image recorded on the glass or the like can be newly adopted in the maintenance station 500.

  (3) In the above, the configuration in which the dot pattern of the test pattern image included in the test image is 4 dots has been described as an example. However, other configurations are possible, and the number of dots can be determined in consideration of various points.

  (4) In the configuration of S106 of the test pattern selection process shown in FIG. 6, when the maximum width of the overlapping part dot row is considerably larger than the average value of the single part dot row, for example, when it is twice or more, A configuration as shown in FIG. 12 can also be adopted. That is, the control unit of the inkjet recording apparatus 100 adjusts, specifically, reduces the amount of ink droplets ejected from the nozzle 424A at the one end and the nozzle 424B at the other end. Thereby, a dot diameter can be made small. The maximum width can be reduced as the dot diameter is reduced.

  (5) In the configuration of S106 of the test pattern selection process shown in FIG. 6, suitable specific test pattern information is selected based on the occupied area and maximum width of each dot row. However, since both have a certain relationship as described above, a configuration may be adopted in which a specific pattern is selected based on at least one of them. In addition to the configuration based on the average value of the occupied area and the maximum width, for example, a configuration for selecting suitable specific test pattern information such as a configuration based on the intermediate value in consideration of variations in the occupied area and the maximum width. You can also

  (6) In the above, if the determination in S108 is affirmative (see S108 in FIG. 6: Yes), the nonvolatile memory stores the appropriate specific test pattern information selected in S106 of the test pattern selection process shown in FIG. The matching pattern configuration information is registered (stored) in association with the corresponding nozzle overlap portion, and the control unit of the ink jet recording apparatus 100 generates a raster image generated from image data received from an external device such as a personal computer. In the above description, a configuration using this pattern configuration information when performing thinning processing (mask processing) has been described.

  As other configurations, the following configurations may be employed. That is, as a process corresponding to S110 in FIG. 6, the control unit of the inkjet recording apparatus 100 transmits the pattern configuration information to an external apparatus that transmits image data to the own apparatus. The external device (control unit of the external device) that has received this registers (stores) the pattern configuration information in the storage area within the own device. When the external apparatus transmits image data to the inkjet recording apparatus 100, a thinning process using pattern configuration information is executed in advance to create a raster image. The control unit of the inkjet recording apparatus 100 executes the printing process according to the received raster image without executing the thinning process. It is also possible to use means.

  (7) In the above description, the recording heads 422-1, 422-2, 422-3, and 422-4 in which the first nozzle row 426A and the second nozzle row 426B are arranged in a staggered manner have been described as an example (FIG. 2). However, each of the recording heads in which a different number of nozzle rows, that is, a single row or three or more nozzle rows are formed, can also be used as a recording head unit arranged so that a nozzle overlap portion is formed. . Also in this case, by executing the test pattern information selection process shown in FIG. 6 in the same manner as described above, it is possible to select suitable specific test pattern information for each nozzle overlap portion (S106 in FIG. 6), and to specify each nozzle overlap portion. Pattern configuration information that matches the test pattern information can be registered (S110 in FIG. 6).

  In addition, the nozzle overlapping portion has been described by taking as an example a configuration in which one nozzle 424A at one end and one nozzle 424B at the other end are combined (two in total). However, it is also possible to adopt a configuration in which more than two nozzles 424A on one side end and nozzles 424B on the other side end are combined. Also in this case, the test pattern information selection process shown in FIG. 6 can be executed in the same manner as described above by defining each test pattern information that defines whether or not ink droplets are ejected from each nozzle as shown in FIG. .

  In addition, the configuration in which the dot row by the nozzle overlap portion becomes one row in the test pattern image, that is, the configuration in which one nozzle at the end of each nozzle row is overlapped is described as an example. It can also be set as the structure arrange | positioned. In this case, in S106 of the test pattern selection process shown in FIG. 6, the control unit calculates each average value for the occupied area and the maximum width of the overlapping part dot row by the nozzle overlapping part (see the calculation method using the single part dot row). ). Then, the control unit compares the average value of the occupied area and the maximum width of the overlapping part dot row with the average value of the occupied area and the maximum width of the single part dot row, and a suitable specific test pattern by the same method as described above. Select information.

DESCRIPTION OF SYMBOLS 100 Inkjet recording apparatus 200 Electrical box 300 Belt conveyor 320 Recording medium 400 Carriage 420 Recording head unit 422 Recording head 424 Nozzle 424A Nozzle at one end 424B Nozzle at the other end 426 Nozzle row 426A First nozzle row 426B Second nozzle Row 500 Maintenance station 520 Roll paper 540 CCD camera

Claims (6)

Each recording head in which a nozzle row in which a plurality of nozzles are arranged is formed in a direction orthogonal to a conveyance direction in which a recording medium on which a recording image indicated by image data input from an external device is recorded, A line-type inkjet recording apparatus comprising a recording head unit arranged such that a nozzle at one end of the recording head and a nozzle at the other end of the recording head overlap in the transport direction,
In the case where a test pattern image is recorded by ejecting ink droplets from the nozzle row, whether or not ink droplets are ejected from the nozzles on the one side end and ejection of ink droplets from the nozzles on the other side end A storage unit for storing a plurality of test pattern information including information on presence / absence, and
About discharge of the ink droplet from the nozzle of the said one side edge part, and discharge of the ink drop from the nozzle of the said other side edge part, it discharges according to each of several test pattern information memorize | stored in the said memory | storage part, Regarding the ejection of ink droplets from nozzles other than the nozzle at the side end and the nozzle at the other end, the ejection of the ink droplet from the nozzle at the one end or the ink droplet from the nozzle at the other end A test pattern recording unit that controls the recording of a single test image that includes each test pattern image corresponding to each of the test pattern information.
A reading unit for reading the test image;
An analysis unit for analyzing each test pattern image included in the test image read by the reading unit;
From the analysis result of each test pattern image by the analysis unit, a selection unit that selects test pattern information of a specific test pattern image that satisfies a predetermined condition as specific test pattern information,
In the case of recording the recording image on the recording medium, ink droplet ejection from the nozzle on the one side end and nozzle on the other side end corresponding to the specific test pattern information selected by the selection unit An ink jet recording apparatus comprising: an image data recording unit that controls ejection of the ink droplets. The test pattern image is an image in which dots by ink droplets ejected from each nozzle of the nozzle row are formed by a predetermined number of dot rows in the transport direction,
The analysis unit, for each test pattern image included in the test image, for each nozzle row including the nozzle on the one side end, each dot row by each nozzle other than the nozzle on the one side end, and the other side end First dot row analysis information corresponding to each of the dot rows by the nozzles other than the nozzles at the other end of the nozzle row including the nozzles of the other part, and the acquired first dot row analysis information The second dot row analysis information is acquired using each, and further, for each test pattern image included in the test image, corresponds to the dot row by the nozzle on the one side end and the nozzle on the other side end. Acquire third dot row analysis information,
The selection unit compares the second dot row analysis information and the third dot row analysis information for each test pattern image included in the test image, and compares the second dot row analysis information and the third dot row. 2. The ink jet recording apparatus according to claim 1, wherein test pattern information of a test pattern image that is closest to analysis information is selected as the specific test pattern information. Each of the plurality of test pattern information stored in the storage unit is given a priority,
As a result of comparing the second dot row analysis information and the third dot row analysis information for each test pattern image included in the test image, the selection unit has a plurality of test pattern information of the closest test pattern image. 3. The ink jet recording apparatus according to claim 2, wherein, when extracted, the specific test pattern information is selected according to the priority order. The ink jet recording apparatus comprises:
A maintenance station for recording the test image;
A moving unit that moves the recording head unit to the maintenance station;
The test pattern recording unit controls the movement of the recording head to the maintenance station by the moving unit, and controls the recording of the test image while the recording head unit is moved to the maintenance station.
4. The apparatus according to claim 1, wherein the reading unit is installed in the maintenance station and reads a test image recorded in a state where the recording head unit is moved to the maintenance station. 5. The ink jet recording apparatus described. Each recording head in which a nozzle row in which a plurality of nozzles are arranged is formed in a direction orthogonal to a conveyance direction in which a recording medium on which a recording image indicated by image data input from an external device is recorded, A recording head unit arranged such that a nozzle at one end of the recording head and a nozzle at the other end of the recording head overlap in the transport direction, and ejects ink droplets from the nozzle row; In the case of recording a test pattern image, a test pattern including information on whether or not ink droplets are ejected from the nozzle on the one side end and whether or not ink droplets are ejected from the nozzle on the other side end A plurality of information is stored, and ink droplets are ejected from the nozzles at the one side end and ink droplets are ejected from the nozzle at the other side end corresponding to the specific test pattern information. Controlling the door, a method of adjusting an ink jet recording apparatus capable of recording line-type in the recorded image the recording medium,
About discharge of the ink droplet from the nozzle of the said one side edge part, and discharge of the ink drop from the nozzle of the said other side edge part, it discharges according to each of several test pattern information memorize | stored in the said memory | storage part, Regarding the ejection of ink droplets from nozzles other than the nozzle at the side end and the nozzle at the other end, the ejection of the ink droplet from the nozzle at the one end or the ink droplet from the nozzle at the other end A test pattern recording step for controlling the recording of a single test image including each test pattern image corresponding to each of the test pattern information.
A reading step of reading the test image;
An analysis step of analyzing each test pattern image included in the test image read by the reading step;
A selection step of selecting, as the specific test pattern information, test pattern information of the test pattern image satisfying a predetermined condition from the analysis result of each test pattern image in the analysis step . Each recording head in which a nozzle row in which a plurality of nozzles are arranged is formed in a direction orthogonal to a conveyance direction in which a recording medium on which a recording image indicated by image data input from an external device is recorded, A recording head unit arranged such that a nozzle at one end of the recording head and a nozzle at the other end of the recording head overlap in the transport direction; and ejecting ink droplets from the nozzle row In the case of recording a test pattern image, test pattern information including information on whether or not ink droplets are ejected from the nozzles on the one side end and whether or not ink droplets are ejected from the nozzles on the other side end An ink jet recording method using a line type ink jet recording apparatus comprising:
About discharge of the ink droplet from the nozzle of the said one side edge part, and discharge of the ink drop from the nozzle of the said other side edge part, it discharges according to each of several test pattern information memorize | stored in the said memory | storage part, Regarding the ejection of ink droplets from nozzles other than the nozzle at the side end and the nozzle at the other end, the ejection of the ink droplet from the nozzle at the one end or the ink droplet from the nozzle at the other end A test pattern recording step for controlling the recording of a single test image including each test pattern image corresponding to each of the test pattern information.
A reading step of reading the test image;
An analysis step of analyzing each test pattern image included in the test image read by the reading step;
From the analysis result of each test pattern image by the analysis step, a selection step of selecting test pattern information of the test pattern image satisfying a predetermined condition as specific test pattern information,
Controlling the ejection of ink droplets from the nozzles at one end and the ejection of ink droplets from the nozzle at the other end corresponding to the specific test pattern information selected in the selection step, And an image data recording step of recording the image on the recording medium.

Images