JP4306448B2 - Inkjet printer - Google Patents

Description

  The present invention relates to an ink jet printer, and more particularly to an ink jet printer having a line head.

  In general, many ink jet printers are used because noise during printing is relatively small and printing quality is good. The ink jet printer has, for example, a fixed line head in which nozzles are arranged over the entire width of the recording medium, and images are transferred while the recording medium is conveyed in a conveying direction orthogonal to the width direction. There is a line system to be formed.

  In the line-type inkjet printer as described above, for example, the ink ejected from each nozzle of a long line head must land on the recording medium so that it is aligned on a straight line that matches the width direction of the recording medium. I must. For this reason, the arrangement direction of the nozzles arranged in the line head must exactly coincide with the width direction of the recording medium, in other words, the arrangement direction of the nozzles needs to be exactly orthogonal to the conveyance direction of the recording medium. .

The line head may be composed of a plurality of short head blocks arranged in two staggered rows. In the case of such a line head, the ink ejected from the nozzles of each of the plurality of head blocks must land on the recording medium so as to be aligned on a straight line that coincides with the width direction of the recording medium as a result. Don't be.
For this reason, the arrangement direction of the nozzles of each of the plurality of head blocks is aligned with the width direction of the recording medium, and the ink landing positions are aligned on a straight line between the head blocks in the same row and the width direction of the recording medium. It is necessary to adjust to.
If these alignments are insufficient, ink cannot be ejected to an accurate landing position on the recording medium, and a good image may not be formed.

Therefore, conventionally, an inclination measurement is performed to measure whether or not the recording head is arranged in an appropriate position and direction for alignment of the recording head.
As such a method, for example, there is a method in which two or more nozzle positions in the recording head are detected by a CCD camera, and the inclination of the recording head is measured based on the positional relationship (for example, see Patent Document 1).
There is also a method in which ink dots ejected from two or more nozzles are detected by a CCD camera to calculate position coordinates, and the inclination of the recording head is measured based on the positional relationship (for example, see Patent Document 2).
Further, a recording medium having an inclination measurement pattern in which lines parallel to the width direction of the recording medium are previously described at predetermined equal intervals is used, and ink is ejected from the nozzles of the line head to the recording medium at the same intervals as the pattern. There is also a method for measuring the inclination of the line head by comparing the inclination measurement pattern with a line formed on the recording medium by the line head (see, for example, Patent Document 3).
JP 2001-286813 A JP 2001-286812 A JP 2003-170645 A

However, the method of calculating the positional relationship by detecting the positions of two or more nozzles or two or more ink dots with the CCD camera has a problem that the cost is increased because the CCD camera is expensive.
In addition, in the method of measuring the inclination of the line head by ejecting ink in a predetermined pattern onto a recording medium preliminarily printed with a parallel inclination measurement pattern, it is necessary to produce a detailed chart (an inclination measurement pattern). There was a problem that it took time and cost.

  SUMMARY OF THE INVENTION An object of the present invention is to provide an ink jet printer that can suppress the cost without increasing the hardware and mechanical structure and can easily perform the inclination measurement for the alignment of the line head. To do.

The invention described in claim 1
A line head in which nozzles for ejecting ink are arranged over the entire width of the recording medium;
A head holder on which one or a plurality of the line heads are mounted;
A recording medium transport mechanism for transporting the recording medium in a transport direction orthogonal to the width direction of the recording medium so as to face the line head;
In an inkjet printer comprising:
The position of the head holder can be changed so that the arrangement direction of the nozzles of the line head changes from the width direction of the recording medium to the conveyance direction of the recording medium,
And it is possible to eject ink even in a state where the arrangement direction of the nozzles is changed to the conveyance direction of the recording medium,
When aligning the line head,
Change the position of the head holder so that the arrangement direction of the nozzles of the line head is the conveyance direction of the recording medium,
In that state, the ink is ejected from the nozzles while transporting the recording medium,
It is characterized in that the inclination of the line head is measured by a recording pattern formed on the recording medium.

  Thus, according to the first aspect of the present invention, the position of the head holder can be changed so that the arrangement direction of the nozzles of the line head is changed from the width direction of the recording medium to the conveyance direction of the recording medium, and the nozzle Ink can be ejected even when the arrangement direction of the recording medium is changed to the conveyance direction of the recording medium. When aligning the line head, the head is arranged so that the arrangement direction of the nozzles of the line head is the conveyance direction of the recording medium. The position of the holder is changed, the ink is ejected from the nozzle while the recording medium is conveyed in that state, and the inclination of the line head is measured by the recording pattern formed on the recording medium. If it is disposed at a proper position, a linear recording pattern parallel to the conveyance direction of the recording medium is formed on the recording medium in the tilt measurement.

The invention according to claim 2 is the inkjet printer according to claim 1,
The line head includes a plurality of head blocks in which nozzles are arranged in the width direction of the recording medium.

  Thus, according to the second aspect of the present invention, the line head is composed of a plurality of head blocks in which nozzles are arranged in the width direction of the recording medium. When the head block is combined into a line head, it is necessary to measure whether or not the ink is discharged in a straight line. Here, since the inclination measurement is performed so that the nozzle arrangement direction in each head block of the line head is the conveyance direction of the recording medium, if each head block is disposed at an appropriate position, the recording is performed in the inclination measurement. At least two linear recording patterns parallel to the conveyance direction of the recording medium are formed on the medium.

The invention according to claim 3 is the inkjet printer according to claim 2,
When aligning the line head,
Ink is ejected from at least two nozzles near both ends of the nozzles arranged in each head block.

  As described above, according to the third aspect of the present invention, when the line heads are aligned, the ink is ejected from at least two nozzles in the vicinity of both ends of the nozzles arranged in each head block. Therefore, when the head block is deviated from an appropriate position, the state can be easily understood by looking at the ink discharge position of the nozzle at a distant position.

The invention according to claim 4 is the inkjet printer according to any one of claims 1 to 3,
A rotation mechanism is provided that rotates the head holder so that the arrangement direction of the nozzles of the line head can be changed in both the width direction of the recording medium and the conveyance direction of the recording medium.

  Thus, according to the fourth aspect of the invention, the rotation mechanism that rotates the head holder so that the arrangement direction of the nozzles of the line head can be changed in both the width direction of the recording medium and the conveyance direction of the recording medium. Therefore, the position of the head holder can be changed easily and reliably.

Invention of Claim 5 is the inkjet printer as described in any one of Claims 1-4,
When aligning the line head,
Ink is continuously ejected from the nozzles to form a solid line-shaped recording pattern on a recording medium.

  Thus, according to the fifth aspect of the present invention, when the alignment of the line head is performed, ink is continuously ejected from the nozzles to form a solid line-shaped recording pattern on the recording medium. Therefore, it is possible to form the recording pattern in a state in which the inclination measurement result can be easily understood.

  According to the first aspect of the present invention, if the line head is disposed at an appropriate position, a linear recording pattern parallel to the conveyance direction of the recording medium is formed on the recording medium in the inclination measurement. Therefore, it is possible to visually confirm information on whether or not there is a deviation in the nozzle arrangement direction of the line head, and it is possible to easily measure the inclination of the line head. Furthermore, since no special device is required for the measurement, the tilt measurement can be performed at a reduced cost.

  According to the second aspect of the invention, if each head block is disposed at an appropriate position, at least two linear recording patterns parallel to the conveyance direction of the recording medium are measured on the recording medium in the inclination measurement. If there is a head block that is misaligned, it is possible to know which head block is displaced from the recording pattern writing position. Information on whether or not there is a deviation in the arrangement direction can be confirmed by visual observation, and the inclination of a line head composed of a plurality of head blocks can be easily measured. Furthermore, since no special device is required for the measurement, the tilt measurement can be performed at a reduced cost.

  According to the third aspect of the present invention, when the head block is deviated from an appropriate position, the state can be easily understood by looking at the ink discharge position of the nozzle at a distant position. Can be measured.

  According to the fourth aspect of the present invention, the position of the head holder can be changed easily and reliably, and as a result, the tilt measurement operation can be performed easily and reliably.

  According to the fifth aspect of the present invention, since the recording pattern can be formed in a state in which the result of the tilt measurement is easier to understand, the work of the tilt measurement can be easily and reliably performed as a result.

  Hereinafter, embodiments of an inkjet printer according to the present invention will be described with reference to the drawings. However, the present invention is not limited to the illustrated example.

  FIG. 1 is a diagram showing a schematic configuration of an ink jet printer according to an embodiment of the present invention, and FIG. 2 is a diagram showing a state where a head holder of the ink jet printer of FIG. 1 is rotated by 90 °. FIG. 3 is a control block diagram showing the main control configuration of the ink jet printer according to the present embodiment, and FIG. 4 is a recording of ink ejection from the nozzles of each head block in the tilt measurement performed when the line head is aligned. It is a figure which shows a pattern.

  As shown in FIG. 1, the ink jet printer 1 is a line type ink jet printer, and includes a flat platen 2 that supports a non-recording surface on the back side of a recording surface of a recording medium 99. Conveying rollers 3a and 3b of the recording medium conveying mechanism 3 are disposed before and after the platen 2, respectively. The conveying rollers 3a and 3b are coupled by a conveying belt 3c and rotate in a predetermined direction around the axis before and after the platen 2, and the recording medium 99 is conveyed along with the rotation of the conveying rollers 3a and 3b. It is conveyed along the direction A.

  Above the platen 2, a head holder 4 having a line head for forming an image on the recording surface of the recording medium 99 is disposed. The head holder 4 of the present embodiment ejects yellow (Y), magenta (M), cyan (C), and black (K) process color inks 4 toward the recording surface of the recording medium 99, respectively. Two line heads 5, 6, 7, and 8 are arranged from the upstream side to the downstream side in the conveyance direction A of the recording medium 99. Each of the line heads 5, 6, 7, and 8 is a recording head that extends over the entire width in the width direction B of the recording medium 99 orthogonal to the transport direction A. Each of the line heads 5, 6, 7, and 8 is arranged with a plurality of nozzles that eject ink as droplets over the entire width of the recording medium 99 in the width direction B. It can be discharged.

Each of the line heads 5, 6, 7, and 8 according to the present embodiment has a configuration in which a plurality of head blocks in which nozzles are arranged in the same arrangement direction C as the width direction B of the recording medium 99 are arranged in two staggered rows. It has become. Specifically, the yellow line head 5 includes six head blocks 51, 52, 53, 54, 55, and 56 arranged in two rows in a zigzag pattern. Nozzles are arranged in the same arrangement direction C to form nozzle rows 51a, 52a, 53a, 54a, 55a, 56a.
Similarly, the magenta line head 6, the cyan line head 7, and the black line head 8 are also composed of six head blocks arranged in a staggered manner, and are the same as the width direction B of the recording medium 99 in each head block. Nozzles are arranged in the arrangement direction C to form a nozzle row.
Each of these head blocks can be adjusted in position with respect to the head holder 4.

  The head holder 4 of the present embodiment has a substantially square shape in plan view, and the four corners thereof are fixed to the casing of the inkjet printer 1 by positioning pins P. Further, the head holder 4 can be detached from the housing and the like, and once removed, the head holder 4 is rotated by 90 °, that is, the nozzles of the line heads 5, 6, 7, and 8 as shown in FIG. The position can be changed to a state in which the arrangement direction C is the conveyance direction A of the recording medium 99, and it can be attached to the housing or the like again by the positioning pins P. As described above, an ink supply pipe or the like is formed so that ink can be ejected from the nozzles in the head blocks of the line heads 5, 6, 7, and 8 even when the head holder 4 is rotated by 90 °. ing.

In the present embodiment, the positioning pins P are used for fixing and positioning the head holder 4, but the present invention is not limited to this, and the head holder 4 may be fixed and positioned by other methods. For example, at least two abutting pins are provided so as to abut against two adjacent side surfaces of the head holder 4 at a predetermined position, and a spring that presses two side surfaces other than the two side surfaces abutting on these abutting pins, etc. The head holder 4 may be fixed in position by providing a pressing member made of and pressing the head holder 4 against the abutment pin with the pressing member.
Further, in the present embodiment, the position of the head holder 4 is changed by manually removing and attaching it. However, the present invention is not limited to this, and the position of the head holder 4 is mechanically changed to 90 °. A rotating mechanism for rotating is provided so that the arrangement direction C of the nozzles of the line heads 5, 6, 7, and 8 can be automatically changed to both the width direction B and the conveyance direction A of the recording medium 99. May be.

Next, the control configuration in the present embodiment will be described with reference to FIG.
In the present embodiment, the inkjet printer 1 is provided with a control unit 20 that controls each drive unit as shown in FIG. The control unit 20 includes a CPU 21, a RAM 22, a ROM 23, and the like. The control unit 20 is connected to the recording medium transport mechanism 3, the line heads 5, 6, 7, 8 and the recording medium via an interface (not shown). It is electrically connected to an input unit 9 and the like for inputting instructions at the time of image recording such as 99 types. In addition to the above, each drive unit of the inkjet printer 1 is connected to the control unit 20.

The control unit 20 controls the operation of the transport rollers 3a and 3b of the recording medium transport mechanism 3 so that the recording medium 99 is transported in the transport direction A.
The control unit 20 is connected to an input unit 9 and line heads 5, 6, 7, 8 including a host computer and a scanner for inputting image information, a keyboard for inputting image recording conditions, and the like. Is configured to operate the line heads 5, 6, 7 and 8 based on a predetermined signal input from the input unit 9 to discharge ink onto the recording medium 99 to record a predetermined image.

  Further, in the ink jet printer 1 of the present embodiment, the head holder 4 is rotated 90 ° so that the nozzle arrangement direction C of the line heads 5, 6, 7, 8 is positioned from the width direction B of the recording medium 99 to the conveyance direction A. After the change, a recording pattern necessary for measuring the inclination of the line heads 5, 6, 7, and 8 for aligning the line heads 5, 6, 7, and 8 to be described later is formed. . At that time, the control unit 20 controls the recording medium conveyance mechanism 3 to convey the recording medium 99 at a constant speed, and ejects ink from predetermined nozzles to the line heads 5, 6, 7, and 8. To control. In this embodiment, in particular, control is performed so that ink is ejected from at least two nozzles in the vicinity of both ends of the nozzles arranged in the head blocks of the line heads 5, 6, 7, and 8. In addition, when ink is ejected from the nozzles, the ink may be ejected intermittently at a low frequency to form a dotted line-shaped recording pattern on the recording medium 99. In order to obtain a recording pattern in which the tilt state of 6, 7, and 8 is easy to understand, control is performed so that ink is continuously ejected at a high frequency to form a solid line-shaped recording pattern on the recording medium 99.

Next, the operation of the ink jet printer 1 in the present embodiment will be described.
First, the operator sets the recording medium 99 in the ink jet printer 1 and turns on the power of the ink jet printer 1. When image information is sent from the input unit 9 to the control unit 20 of the inkjet printer 1 and setting information for various image recording conditions is sent, the control unit 20 starts image recording.
During the operation of the ink jet printer 1, the transport rollers 3 a and 3 b are operated and rotated, and the recording medium 99 is supported along the transport direction A from the rear to the front with the non-recording surface supported by the platen 2. Conveyed continuously.

  In this state, the four line heads 5, 6, 7, 8 respectively discharge ink as fine droplets from the nozzles toward the recording surface of the recording medium 99, so that the recording medium 99 has each line head 5. , 6, 7 and 8, Y, M, C and K inks land on the recording surface of the recording medium 99.

  Thereafter, the inkjet printer 1 repeats the above operations, and a desired image composed of a plurality of dots of each process color is sequentially recorded on the recording surface of the recording medium 99.

Here, the alignment of the line heads 5, 6, 7, and 8 in the inkjet printer 1 will be described.
In the ink jet printer 1, the ink ejected at a time from the plurality of nozzles in each of the line heads 5, 6, 7, and 8 eventually coincides with the width direction B of the recording medium 99 when the recording medium 99 is conveyed. It is necessary to land on a straight line. For this reason, in the present embodiment, the ink ejected at a time from the nozzles of the head blocks in the same row among the plurality of head blocks arranged in the staggered two rows with the recording medium 99 stopped. Therefore, it is necessary to perform alignment so that all the inks land on two parallel lines that coincide with the width direction B of the recording medium 99 as a result.
In order to align the line heads 5, 6, 7, and 8, are the line heads 5, 6, 7, and 8 disposed at positions where appropriate ink ejection can be performed as described above. It is necessary to measure whether or not. For example, the ink ejected from the nozzles of the line heads 5, 6, 7, and 8 has landed on two parallel lines that coincide with the width direction B of the recording medium 99, or the width direction B Inclination measurement is performed to determine whether or not it has landed at a position deviated from two parallel lines that coincide with each other.
In order to perform the inclination measurement, it is necessary to form an ink ejection recording pattern.

Hereinafter, a procedure for forming the recording pattern of the ink discharge will be described.
In the ink jet printer 1 of the present embodiment, first, the head holder 4 fixed by the positioning pins P is rotated 90 ° to change the nozzle arrangement direction C of the line heads 5, 6, 7, 8 to the recording medium 99. The position is changed from the width direction B to the conveyance direction A, and the position is fixed with the positioning pins P again. The recording medium transport mechanism 3 transports the recording medium 99 at a constant speed and ejects ink from predetermined nozzles of the line heads 5, 6, 7, and 8. In the present embodiment, in particular, ink is ejected from at least two nozzles in the vicinity of both ends of the nozzles arranged in the head blocks of the line heads 5, 6, 7, and 8. In this embodiment, when ink is ejected from the nozzles, the ink is continuously ejected at a high frequency in order to obtain a recording pattern in which the inclination of the line heads 5, 6, 7, and 8 can be easily understood. A solid line-shaped recording pattern is formed on the recording medium 99.

  Hereinafter, a specific example of measuring the inclination of the line head will be described with reference to FIGS. 2 and 4. Here, the yellow line head 5 among the line heads will be described. However, the configuration, control, operation, and the like described for the yellow line head 5 are also applied to the other line heads 6, 7, and 8. Shall.

  As described above, first, the nozzle arrangement direction C arranged in each of the head blocks 51, 52, 53, 54, 55, 56 of the line head 5, that is, the nozzle rows 51a, 52a, 53a, 54a, 55a, 56a. The head holder 4 is rotated and fixed with the positioning pins P so that the row direction is the conveyance direction A of the recording medium 99. And while conveying the recording medium 99 at a constant speed, two or more of the nozzle rows 51a, 52a, 53a, 54a, 55a, 56a of each head block 51, 52, 53, 54, 55, 56 are near or at both ends. Ink is continuously ejected from the nozzles. In the present embodiment, ink is continuously ejected from the two nozzles at both ends of the nozzle rows 51a, 52a, 53a, 54a, 55a, and 56a of the head blocks 51, 52, 53, 54, 55, and 56. Thus, the recording medium 99 is conveyed by a length longer than the nozzle row of each head block.

Here, the recording pattern of ink ejected from the nozzle 51b on the front end side in the transport direction A in the nozzle row 51a of the head block 51 is denoted by D, and the nozzle on the rear end side in the transport direction A in the nozzle row 51a of the head block 51 The recording pattern of the ink ejected from 51c is represented by E.
In addition, a recording pattern of ink ejected from the nozzle 52b on the front end side in the transport direction A in the nozzle row 52a of the head block 52 is denoted by F, and the nozzle 52c on the rear end side in the transport direction A in the nozzle row 52a of the head block 52. The recording pattern of the ink ejected from is represented by G.
In addition, the recording pattern of ink ejected from the nozzle 53b on the front end side in the transport direction A in the nozzle row 53a of the head block 53 is denoted by H, and the nozzle 53c on the rear end side in the transport direction A in the nozzle row 53a of the head block 53. The recording pattern of the ink ejected from is denoted by I.
Also, J represents the recording pattern of the ink ejected from the nozzle 54b on the front end side in the transport direction A in the nozzle row 54a of the head block 54, and the nozzle 54c on the rear end side in the transport direction A in the nozzle row 54a of the head block 54. The recording pattern of the ink ejected from is represented by K.
In addition, the recording pattern of ink ejected from the nozzle 55b on the front end side in the transport direction A in the nozzle row 55a of the head block 55 is denoted by L, and the nozzle 55c on the rear end side in the transport direction A in the nozzle row 55a of the head block 55. The recording pattern of the ink ejected from is represented by M.
The recording pattern of the ink ejected from the nozzle 56b on the front end side in the transport direction A in the nozzle row 56a of the head block 56 is represented by N, and the nozzle 56c on the rear end side in the transport direction A in the nozzle row 56a of the head block 56. The recording pattern of the ink ejected from is represented by O.

  When the recording pattern is formed on the recording medium 99 as described above, the positions of the head blocks 51, 52, 53, 54, 55, 56 and the position of the line head 5 as a whole are in an appropriate state. The recording pattern is formed as shown in FIG. That is, the recording patterns D, E, H, I, L, and M by the nozzles of the head blocks 51, 53, and 55 in one row of the head blocks arranged in two rows in a staggered pattern are the conveyance directions of the recording medium 99. A, and the recording patterns F, G, J, K, N, and O by the nozzles of the head blocks 52, 54, and 56 in the other row also coincide with the conveyance direction A of the recording medium 99. Thus, two solid straight lines parallel to both edges of the recording medium 99 are recorded on the recording medium 99. Note that the black dots on the straight line in FIG. 4 are described for convenience in displaying each recording pattern in an easy-to-understand manner, and do not appear in the actual recording pattern.

On the other hand, when at least one of the head blocks 51, 52, 53, 54, 55, and 56 is in an inappropriate state, the recording pattern is recorded out of the two parallel lines. Something happens.
For example, when the position on the tip side of the nozzle row 52a of the head block 52 is inclined from an appropriate position, the nozzle on the tip side of the nozzle row 52a of the head block 52 is shown in FIG. The recording pattern F of ink ejected from 52b is recorded at a position different from the two parallel lines on which other recording patterns are recorded. In this case, the alignment is performed by calculating the inclination of the head block 52 from the deviation width of the recording pattern F of the nozzle 52b with respect to another recording pattern.

Further, when the position of the entire line head 5 is in an inappropriate state, the recording pattern does not become a straight line parallel to both edges of the recording medium 99.
For example, when the position of the line head 5 as a whole is tilted with respect to the conveyance direction A of the recording medium 99, as shown in FIG. The image is recorded diagonally. In this case, the entire line head 5 is aligned by calculating the inclination angle of the recording pattern with respect to the conveyance direction A.

  As described above, the position adjustment of the head block and the adjustment of the inclination of the entire line head are performed based on the recording pattern, and the two recording patterns match the transport direction as shown in FIG. The alignment is performed so as to form a line.

Note that the ink ejection method in the inclination measurement is not limited to the above-described method of ejecting ink beyond the length of the nozzle row of each head block, and other methods are also conceivable.
For example, as shown in FIG. 4D, there is a case where a recording pattern is formed in a fine dotted line shape by ejecting ink at a length equal to or less than the length of the nozzle row.
Further, in the present embodiment, the recording pattern is formed by ejecting ink from only two nozzles in the vicinity of both ends of the nozzle row for one head block, but the present invention is not limited to this. For example, the recording pattern is formed by ejecting ink from three nozzles in the vicinity of both ends and the center of the nozzle row, or the recording pattern is formed by ejecting ink from all nozzles. You may do it.

  Further, the inclination measurement of the line heads 5, 6, 7, and 8 is not limited to the case of performing the measurement for each line head of each color as described above. For example, if ink is ejected simultaneously from all the line heads 5, 6, 7, and 8 while transporting the recording medium 99, the inclination of all the line heads 5, 6, 7, and 8 can be measured simultaneously. It can be said that it is excellent in work efficiency and cost. Further, by simultaneously forming a recording pattern of a plurality of line heads, there is also an effect that the distance between the line heads can be measured.

  Furthermore, in this embodiment, the recording pattern is visually observed and its inclination is measured. However, the present invention is not limited to this. For example, a sensor may be provided and the recording pattern may be read by the sensor. If it is read by a sensor, the measurement data can be digitized as it is, and work efficiency is improved.

  In this embodiment, four line heads are mounted on the head holder. However, the present invention is not limited to this, and a plurality of line heads other than one or four are mounted. It may be.

  Furthermore, the head holder of the present embodiment has a substantially square shape in plan view, but the shape of the head holder is not limited to this, and the arrangement direction of the nozzles of the line head is changed from the width direction of the recording medium to the transport direction. As long as the position can be changed, an appropriate shape may be used.

  Furthermore, in this embodiment, the line head is composed of six head blocks, but the present invention is not limited to this, and the line head may be composed of a plurality of head blocks other than six. The present invention can also be applied to a long line head composed of one head block.

As described above, according to the ink jet printer of the present embodiment, the position of the head holder can be changed so that the arrangement direction of the nozzles of the line head changes from the width direction of the recording medium to the conveyance direction of the recording medium, and Ink discharge is possible even when the nozzle arrangement direction is changed to the recording medium conveyance direction, and when the line head is aligned, the line head nozzle arrangement direction becomes the recording medium conveyance direction. The position of the head holder is changed, the ink is ejected from the nozzle while the recording medium is conveyed in this state, and the inclination of the line head is measured by the recording pattern formed on the recording medium. Is arranged at an appropriate position, a linear recording pattern parallel to the conveyance direction of the recording medium is formed on the recording medium in the tilt measurement. It is is will be.
As a result, information on whether or not there is a deviation in the arrangement direction of the nozzles of the line head can be confirmed visually, and the inclination of the line head can be easily measured. Furthermore, since no special device is required for the measurement, the tilt measurement can be performed at a reduced cost.

In this embodiment, since the line head is composed of a plurality of head blocks in which nozzles are arranged in the width direction of the recording medium, the tilt measurement of each head block and the head are performed when the line head is aligned. When the blocks are combined into a line head, it is necessary to measure whether the ink is eventually ejected in a straight line. Here, since the inclination measurement is performed so that the nozzle arrangement direction in each head block of the line head is the conveyance direction of the recording medium, if each head block is disposed at an appropriate position, the recording is performed in the inclination measurement. At least two linear recording patterns parallel to the conveyance direction of the recording medium are formed on the medium.
As a result, if there is a head block that is misaligned, it can be seen which head block is misaligned from the recording pattern writing position. It is possible to visually confirm whether or not there is a line, and it is possible to easily measure the inclination of a line head composed of a plurality of head blocks. Furthermore, since no special device is required for the measurement, the tilt measurement can be performed at a reduced cost.

Furthermore, in the present embodiment, when the alignment of the line head is performed, the ink is ejected from at least two nozzles in the vicinity of both ends among the nozzles arranged in each head block. When the head block is displaced from an appropriate position, the state can be easily understood by looking at the ink discharge position of the nozzle at a distant position.
As a result, it is possible to reliably measure the inclination of each head block.

Furthermore, the present embodiment includes a rotation mechanism that rotates the head holder so that the arrangement direction of the nozzles of the line head can be changed to both the width direction of the recording medium and the conveyance direction of the recording medium. The position of the head holder can be changed easily and reliably.
As a result, the work of measuring the inclination can be performed easily and reliably.

In this embodiment, when the line head is aligned, ink is continuously ejected from the nozzles to form a solid line-shaped recording pattern on the recording medium. The recording pattern can be formed in a state where the result is easily understood.
As a result, the work of measuring the inclination can be performed easily and reliably. In addition, by ejecting ink continuously, it is possible to avoid the influence of temporary emission bending due to decap and the like.

Furthermore, in this embodiment, when aligning the line head, since the ink is ejected so as to be longer than the nozzle row, recording is performed so that the dots of ink ejected from each nozzle partially overlap each other. A pattern can be formed, and the effect that position detection is easy is also produced.
In addition, the ink landing timing may be adjusted in order to adjust the ink discharge position from the line head. In this case as well, it is possible to obtain the difference in the landing timing of each nozzle by looking at the recording pattern. Thus, the landing timing can be accurately adjusted based on the recording pattern.

  The present invention is not limited to the above-described embodiment, and various improvements and design changes may be made without departing from the spirit of the present invention.

1 is a diagram illustrating a schematic configuration of an inkjet printer according to an embodiment of the present invention. It is a figure which shows the state which rotated 90 degrees of the head holder of the inkjet printer of FIG. It is a control block diagram which shows the main control structures of the inkjet printer in this Embodiment. It is a figure which shows the recording pattern of the ink discharge of the nozzle of each head block in the inclination measurement performed in the case of alignment of a line head.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Inkjet printer 2 Platen 3 Recording medium conveyance mechanism 4 Head holder 5, 6, 7, 8 Line head 20 Control part 51, 52, 53, 54, 55, 56 Head block 51a, 52a, 53a, 54a, 55a, 56a Nozzle Rows 51b, 51c, 52b, 52c, 53b, 53c, 54b, 54c, 55b, 55c, 56b, 56c Nozzle 99 Recording medium A Recording medium transport direction B Recording medium width direction C Nozzle arrangement directions D, E, F , G, H, I, J, K, L, M, N, O Recording pattern P Positioning pin

Claims (5)

A line head in which nozzles for ejecting ink are arranged over the entire width of the recording medium;
A head holder on which one or a plurality of the line heads are mounted;
A recording medium transport mechanism for transporting the recording medium in a transport direction orthogonal to the width direction of the recording medium so as to face the line head;
In an inkjet printer comprising:
The position of the head holder can be changed so that the arrangement direction of the nozzles of the line head changes from the width direction of the recording medium to the conveyance direction of the recording medium,
And it is possible to eject ink even in a state where the arrangement direction of the nozzles is changed to the conveyance direction of the recording medium,
When aligning the line head,
Change the position of the head holder so that the arrangement direction of the nozzles of the line head is the conveyance direction of the recording medium,
In that state, the ink is ejected from the nozzles while transporting the recording medium,
An inkjet printer, wherein the inclination of the line head is measured by a recording pattern formed on the recording medium. The inkjet printer according to claim 1, wherein
The inkjet printer according to claim 1, wherein the line head includes a plurality of head blocks in which nozzles are arranged in a width direction of the recording medium. The inkjet printer according to claim 2, wherein
When aligning the line head,
An ink jet printer wherein ink is ejected from at least two nozzles in the vicinity of both ends of the nozzles arranged in each head block. In the inkjet printer as described in any one of Claims 1-3,
An inkjet comprising: a rotation mechanism that rotates the head holder so that an arrangement direction of nozzles of the line head can be changed in both a width direction of the recording medium and a conveyance direction of the recording medium. Printer. In the ink jet printer according to any one of claims 1 to 4,
When aligning the line head,
An ink jet printer, wherein ink is continuously ejected from the nozzles to form a solid line recording pattern on a recording medium.

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