JP2003165210A - Ink jet printer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an ink jet printer in which print quality can be sustained appropriately even when a plurality of ink nozzle arrays constituting a line are arranged while being shifted from each other in the main scanning direction. <P>SOLUTION: An ink nozzle array group 46 having a plurality of ink nozzle arrays 47a for respective ink colors being used for printing a line is divided, in the line direction, into a plurality of divided ink nozzle array groups 47 for respective ink colors and the plurality of divided ink nozzle array groups 47 are arranged while being shifted in the main scanning direction to constitute an ink jet head 26. In the ink jet printer comprising a plurality of such ink jet heads 26, a plurality of linear sensors 133 provided in a head unit 24 in correspondence with the plurality of divided ink nozzle array groups 47 while facing the linear scale 131 are arranged while being shifted in the main scanning direction by an amount corresponding to positional shift of the plurality of divided ink nozzle array groups 47. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink jet printer in which an ink nozzle row used for printing one line (a row of ink nozzles in one head unit in the sub-scanning direction) is composed of a plurality of ink jet heads. is there.

[0002]

2. Description of the Related Art In a conventional ink jet printer, a carriage carrying an ink jet head is moved in the main scanning direction, and ink is ejected from an ink nozzle row of the ink jet head to print on an object to be printed. Ink ejection control to the print target is performed by using a linear encoder provided in the main scanning direction on the printer main body side and a linear encoder made up of a linear sensor provided on the carriage facing the movement position information of the inkjet head in the main scanning direction. It is based on. By the way, in a large-scale inkjet printer for business use, a plurality of ink nozzle rows used for printing one line are composed of a plurality of inkjet heads that are displaced in the main scanning direction. A method of artificially increasing the number is adopted. In this case, the ink ejection control of each inkjet head is performed by detecting the moving position of each inkjet head via one linear sensor.

[0003]

Therefore, in such a conventional large-sized ink jet printer, when printing on one line, for example, the linear scale detection points (total slits) detected by the linear sensor are arranged between the ink nozzle rows. The number of counts) is different. Therefore, the print quality may be affected. That is, since the linear sensor detects each ink nozzle row at different positions deviated by the distance between the nozzle rows, if the accuracy of the linear scale is poor between the positional deviations (for example, slits with unequal pitch or , If the linear scale is provided in an inappropriate form, etc.)
However, depending on this, an error may occur in the ink ejection timing between the ink nozzle rows, and as a result, a portion of one printed line may be displaced from the line in the main scanning direction. .

The present invention provides an ink jet printer capable of maintaining an appropriate print quality even if a plurality of ink nozzle rows forming one line are displaced from each other in the main scanning direction. Is the purpose.

[0005]

The ink jet printer of the present invention is an ink jet printer comprising a plurality of ink jet heads in which a plurality of ink nozzle rows used for printing one line are displaced in the main scanning direction. A head unit in which a plurality of inkjet heads are mounted on a carriage, a moving mechanism that moves the head units in the main scanning direction, and a linear encoder that detects a moving position of the inkjet head in the main scanning direction,
The linear encoder includes a control unit that controls the drive of the moving mechanism and the ink ejection drive of each inkjet head based on the position information of the linear encoder. The linear encoder includes a single linear scale extending in the main scanning direction and a linear scale. And a plurality of linear sensors provided in the head unit corresponding to the plurality of ink nozzle rows, and the plurality of linear sensors are arranged with a positional deviation in the main scanning direction corresponding to the positional deviation of the plurality of ink nozzle rows. It is characterized by being installed.

According to this structure, the plurality of linear sensors are separated from each other by an amount corresponding to the positional deviation of the ink nozzle rows, corresponding to the plurality of ink nozzle rows used for printing one line which is displaced in the main scanning direction. It is provided on the head unit. That is, the nozzle row distance between adjacent ink nozzle rows in the main scanning direction and the linear sensor distance between the corresponding linear sensors are configured to be the same, and the movement position of each ink nozzle row in the main scanning direction is It can be detected individually by each corresponding linear sensor. As a result, the detection points of the linear sensors on the linear scales are completely the same between the ink nozzle rows, regardless of the malfunction of the linear scales, so that one line can be printed appropriately. In other words, in a certain one-line printing, the ink ejection drive of each ink nozzle row can be based on the same detection point on the linear scale. Therefore, the respective linear sensors can individually manage the respective ink nozzle rows, so that appropriate printing can be performed. In addition, "1 line" said here
Means the arrangement of all the ink nozzles in one head unit in the sub-scanning direction, not the width of the print target.

Another ink jet printer of the present invention is
An ink nozzle row group having a plurality of ink nozzle rows used for printing one line for each ink color is divided in a line direction into a plurality of divided ink nozzle row groups for each ink color,
In an inkjet printer configured by a plurality of inkjet heads in which the plurality of divided ink nozzle row groups are displaced in the main scanning direction, a head unit in which a plurality of inkjet heads are mounted on a carriage,
A moving mechanism for moving the head unit in the main scanning direction,
The linear encoder includes a linear encoder that detects a moving position of the inkjet head in the main scanning direction, and a control unit that controls the driving of the moving mechanism and the ink ejection driving of each inkjet head based on the position information of the linear encoder. It is composed of a single linear scale extending in the main scanning direction and a plurality of linear sensors provided on the head unit so as to correspond to the plurality of divided ink nozzle row groups while facing the linear scale. Is arranged so as to be displaced in the main scanning direction by the amount of displacement of the divided ink nozzle row group.

According to this structure, the ink nozzle row group used for printing one line and composed of a plurality of color ink nozzle rows is divided into a plurality of divided ink nozzle row groups in the line direction. The group has ink nozzle rows of each color and is displaced in the main scanning direction. Then, a plurality of linear sensors are provided in the head unit in correspondence with the respective displaced ink nozzle row groups, and are separated by the positional displacement. That is, the linear sensor is provided for each divided ink nozzle row group, and the distance between the linear sensors adjacent to each other in the main scanning direction is equal to the distance between the nozzle rows of each color ink nozzle row adjacent to each other in the main scanning direction. Since it is configured, the moving position of each ink nozzle row of each divided ink nozzle row group in the main scanning direction can be individually detected by each corresponding linear sensor. As a result, the detection points of the respective linear sensors with respect to the linear scale completely match between the divided ink nozzle row groups (between the respective color ink nozzle rows) regardless of the problem of the linear scale.
The line can be printed properly. In other words, in a certain one-line printing, the ink ejection drive of each ink nozzle row can be based on the same detection point on the linear scale. Therefore, each linear sensor can individually manage each of the divided ink nozzle row groups (each of the ink nozzle rows), and can be used for appropriate printing.

In this case, it is preferable that the plurality of divided ink nozzle row groups are mounted on the carriage in a staggered manner, and that the ink nozzle rows adjacent in the line direction are formed on the same line.

According to this structure, since a plurality of divided ink nozzle row groups can be collectively arranged on the carriage, the carriage can be made compact and a plurality of ink jet heads can be collectively arranged. can do. Further, even when a plurality of divided ink nozzle groups are collectively arranged, each ink nozzle row between the divided ink nozzle row groups on the line direction is formed on the same line, and thus each divided ink line on the line direction is divided. One linear sensor can also serve as the moving position detection of the ink nozzle row group. That is, since the moving positions of the divided ink nozzle groups that are adjacent to each other in the line direction are the same, it is possible to easily and appropriately manage each ink nozzle row that also serves as one linear sensor.

In these cases, the moving mechanism mounts the head unit and moves X in the main scanning direction.
It is preferable that the linear scale is provided on the frame of the X-axis table, including the axis table and the Y-axis table that moves the head unit in the line direction via the X-axis table.

According to this structure, even if the head unit mounting a plurality of ink jet heads becomes large, it can be easily moved by the X-axis table and the Y-axis table (X / Y robot). Further, since the movement operation of the head unit can be suppressed to the necessary minimum, the printing speed can be increased. Further, a linear scale can be provided by effectively utilizing the frame of the X-axis table. The linear scale is preferably made of a thin film and is attached along the frame surface of the frame of the X-axis table.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention will be described below with reference to the accompanying drawings. The inkjet printer of the embodiment is a personal computer (hereinafter,
It is a large-scale business-use color printer connected to an external device such as a personal computer), and prints a desired image by an inkjet method based on image data created by the external device. Specifically, an inkjet printer is a printer that continuously prints a number of unit images, which are cut out and used as labels, on a printing tape that is continuous paper. For example, a label that is attached to a wrap film of fresh food. It is possible to print in a small lot.

FIG. 1 is an external perspective view showing the overall structure of an inkjet printer, and FIG. 2 is an external perspective view from the back side of the inkjet printer with a part of the structure omitted.

As shown in both figures, the ink jet printer 1 is composed of a large machine base 2 and a small finisher 3 connected to the machine base 2, and is installed on the machine base 2 on the machine base 2 side. Along the printing means 5 for printing on the printing tape A, the tape feeding means 6 for feeding and feeding the roll-shaped printing tape A which is pushed out from the machine base 2 to the right side, and the tape feeding path 4 for longitudinally cutting the machine base 2. A tape feeding means 7 for feeding the supplied printing tape A is provided, and a tape winding means 8 for winding the printed printing tape A received from the tape feeding means 7 in a roll shape is incorporated in the finisher 3 side. There is.

In addition, on the machine base 2, an ink supply means 9 for supplying ink to the head unit 24 (inkjet head 26) of the printing means 5, and a maintenance means 1 for receiving the ink jet head 26 and performing maintenance processing for the ink jet head 26.
0, and a controller 11 for individually and associatedly controlling each of these main components.

The ink jet printer 1 horizontally adsorbs the printing tape A fed from a roll via the adsorption table 70 of the tape feeding means 7, and drives the printing means 5 in this state to produce a large number of images. While the (unit image B) is continuously printed, the printed portion (unit printing area C) is sent out from the suction table 70 at any time to perform the next continuous printing, and finally after the tape winding means 8 prints the printed image. The printing tape A is wound up (see FIGS. 1 and 9). As shown in FIG. 9, in the unit printing area C of the printing tape A, a large number of unit images B, an image position mark D for detecting the position of each unit image B, and a tape feeding for each unit printing area C are carried out. The detection mark E for performing the printing is printed.

The printing tape A is a roll paper with so-called release paper, and has a tape width of 50 mm minimum to 1 maximum.
Plural kinds (11 kinds) having different widths with 10 mm pitch up to 50 mm are prepared. In printing, unit images B to be labels are continuously printed in the extending direction of the printing tape A, and each unit image B is recognized through an image position mark D by another cutting device which is an outside process. It is then half-cut and becomes a label with adhesive.

The ink used for this printing, that is, the ink used for color printing of one line is cyan (C), magenta (M), yellow (Y) and black (K), and light cyan (LC) and light. The ink is composed of a total of 6 reference colors including magenta (LM), and each color ink is supplied from the main tank 61 of each color to each inkjet head 26 (head unit 24) via the ink tube 63 (FIG. 2).

The machine base 2 is constructed by assembling the angle members 12 into a rectangular parallelepiped shape, and fixing the base plate 13 (device base) to the upper part and the shelf plate 14 to the lower part, and to the lower part of the shelf plate 14. Four casters 15 and six support legs 16 with adjusting bolts are attached. On the base plate 13, in addition to the printing means 5, the maintenance means 10 is provided at the center.
The sub-tank 62 side of the ink supply means 9 is arranged on the back side, and the main part of the tape feeding means 7 is arranged on the front side. In addition, at one end in the longitudinal direction of the base plate 13,
The tape supply means 6 is attached via an angle member 12 in the front-rear direction.

The base plate 13 has a substantially rectangular opening on the tape winding means 8 side and on the front side (two places). The base plate 13 and the shelf plate 14 face the openings 17, 17. A tape feeding path 4 is formed between the and, so as to make a large detour downward. Further, on the inner side of the shelf plate 14, the main tank 61 side of the ink supply means 9 is arranged and a large waste ink tank 18 for storing unnecessary waste ink after maintenance is arranged. Further, a controller 11 is arranged between the base plate 13 and the shelf plate 14 on the right front side with the partition plate 19 interposed therebetween.

Although not shown in the drawing, a safety cover is provided on the base plate 13 of the machine base 2 to integrally cover the above-mentioned means and the like, and an opening / closing door is provided in front of the safety cover. Warning lights are provided on the upper surface. A detection switch (detection sensor) for detecting the closing of the opening / closing door is attached to the safety cover. Only when the detection switch detects the closing of the opening / closing door, the main power supply (not shown) turns off.
You can do N. Further, if the opening / closing door is opened while the main power source is on, the main power source is automatically turned off via the detection switch. Note that the warning light has a tape display light unit for displaying the tape end, as well as an operation display light unit for displaying the printing operation.

On the other hand, the finisher 3 comprises a finisher main body 20 and four support legs 21 with adjusting bolts attached to the lower portion of the finisher main body 20. There is. An operation panel 22 for adjusting the winding torque of the printing tape A and the like is provided at the upper left portion of the front surface of the finisher body 20. As with the safety cover,
The main power of the inkjet printer 1 can be turned on only when the finisher 3 is connected to the machine base 2.

Next, each means of the ink jet printer 1 will be described in order. As shown in FIGS. 1 to 3, the printing unit 5 includes a head unit 24 having a large number of inkjet heads 26 mounted thereon, and X and Y for freely moving the head unit 24 in the main scanning direction and the sub scanning direction.
And a moving mechanism 25. The XY movement mechanism 25
An X-axis table 27, which is a so-called XY robot mounted on the base plate 13, which moves the head unit 24 in the X-axis direction (main scanning direction, longitudinal direction of the printing tape A or extending direction), A Y-axis table 28 that moves the axis table 27 in the Y-axis direction (sub-scanning direction, width direction of the printing tape A), and a Y-axis guide that is arranged in parallel with the Y-axis table 28 and that guides the movement of the X-axis table 27. And 29.

Although not shown in the drawing, the X-axis table 27 is provided inside the X-axis table frame 31 constituting the outer shell, but the main scanning ball screw for reciprocating the head unit 24 in the main scanning direction and the main scanning ball. A main scanning motor for rotating the screw forward and backward is housed. Similarly, the Y-axis table 28 includes a Y-axis table frame 32 that constitutes an outer shell.
Inside, a sub-scanning ball screw that reciprocates an X-axis table 27 (not shown) in the sub-scanning direction and a sub-scanning motor that rotates the sub-scanning ball screw forward and backward are housed. The X-axis table frame 31 is provided with a flushing box 121 that is located almost directly above the Y-axis table 28 and that moves with the reciprocating movement of the X-axis table 27.

The Y-axis guides 29 are parallel to the guide plates 35, and three guide columns 34 erected on the base plate 13 so as to straddle the tape feed path 4, and a guide plate 35 passed between the guide columns 34. And a guide rod 36 in the shape of a round bar attached to the X-axis table 27, and supports the X-axis table 27 together with the Y-axis table 28 and guides the reciprocating movement of the X-axis table 27. The guide rail 36 extends partway from the back side to the labor side, and two guide rollers 37 attached to one end of the X-axis table frame 31.
Rolls around.

Reference numerals 38 and 39 in the figure denote an X-axis cable bear (registered trademark) 38 and a Y-axis cable bear 39, respectively, which flexibly protect the piping and wiring leading to the head unit 24. The Y-axis cable bear 39 is a piping plate 6 whose base end is fixed to the X-axis table frame 31.
5 and the tip is fixed to the pipe support plate 66. Further, the X-axis cable carrier 38 has a base end with the base plate 1
3 and the tip is fixed to the piping plate 65.

Although not particularly shown, an X-direction detecting sensor for detecting a reference position (home position, left side in the figure: origin of the X-axis) of the head unit 24, and an X-axis table 27.
And a Y-direction detection sensor for detecting a reference position (home position, rear side in the drawing: origin of the Y-axis) of the head unit 24 via. When the main power supply of the inkjet printer 1 is turned on, the X / Y moving mechanism 25 is always reset to this reference position.

Although not shown, the head unit 24 is provided with a female screw block extending from the horizontal slit formed in the X-axis table frame 31 into the X-axis table frame 31, and this female screw block is used as a main scanning ball screw. It is screwed. Similarly, the Y-axis table frame 3 is attached to one lower end of the X-axis table frame 31.
From the horizontal slit formed in 2 to the Y-axis table frame 3
A female screw block extending inside 2 is attached, and this female screw block is screwed to the sub-scanning ball screw.

The main scanning motor and the sub-scanning motor are connected to the controller 11, and by rotating the main scanning motor forward and backward, the head unit 24 reciprocates in the main scanning direction, and the sub-scanning motor moves forward. By rotating in the reverse direction, the head unit 24 is moved through the X-axis table 27.
Reciprocates in the sub-scanning direction. Then, one line is printed by the movement of the head unit 24 in the main scanning direction, and the head unit 24 is moved to the next line by the movement in the sub scanning direction.

Specifically, with reference to FIGS. 1 and 4, for the printing tape A on the suction table 70,
For example, when printing is started with the upper left position as the print start position P1, 1 is obtained by moving the head unit 24 from this position in the right direction (forward direction in main scanning) by a predetermined distance.
Line printing (main scanning) is performed, and the head unit 24 is moved to the second line (sub scanning) by moving the head unit 24 to the front at the right end, and from there, the head unit 24 is further moved to the left (main scanning). The second line is printed (main scanning) by moving in the backward movement direction in scanning. In this way, the operation is repeated to print all lines (see FIG. 4B).

Further, for example, when printing is completed at the lower right position, the next printing after feeding the tape is performed at this printing end position P.
From 2 to the print start position P1, the head unit 24 is moved in the reverse operation to print all lines (see FIG. 4C). This reduces the movement loss of the head unit 24.
The flushing of the inkjet head 26 is performed on the flushing box 121 at the left end during one reciprocation (printing of two lines).

The head unit 24 is attached to the left and right sides of the support bracket 41, the support bracket 41 having the above-mentioned female screw block attached to the rear surface thereof, the unified carriage 42 (see FIG. 5) horizontally attached to the lower portion of the support bracket 41. Paper dust removing mechanism 43 including a plurality of paper dust removing fans
A plurality of inkjet heads 26 having a plurality of ink nozzles (nozzle rows) formed on the lower surface are mounted on the unified carriage 42. Specifically, the unified carriage 42 is detachably mounted with four partial carriages 44, and each of the partial carriages 44 has three inkjet heads 26 arranged side by side, that is, a total of 12 inkjet heads 26 in all the partial carriages 44. It is installed.

In this case, each ink jet head 26 is screwed and fixed to the partial carriage 44, and each partial carriage 44 has a positioning mounting means 45 composed of a plurality of pins.
Therefore, it is detachably attached to the unified carriage 42. Further, in each of the inkjet heads 26 mounted on each of the partial carriages 44, a nozzle forming portion 26a having ink nozzles is projected downward from the unified carriage 42,
In addition, the nozzle forming portions 26a are arranged so as to face each other, and the ink nozzle row group 46 is centrally arranged (see FIG. 6). On the back side of the nozzle forming portion 26a, an ink supply portion 49 is formed to connect the ink tubes 63 from the sub-tanks 62 of the respective colors to supply the ink of the respective colors.

As schematically shown in FIG. 6, the ink nozzle row group 46 of six colors forming one line of the reference color is divided into four in the line direction, and the divided ink nozzle row group of the divided six colors is formed. 47 has three inkjet heads 2
6 and is mounted on each partial carriage 44. Specifically, the first head 26-1 of the three inkjet heads 26 mounted on each partial carriage 44 is used.
Includes two divided ink nozzle rows 47a for black (K) and cyan (C), and the second head 26-
Two divided ink nozzle rows 47a of light cyan (LC) and light magenta (LM) are incorporated in No. 2, and two divided ink nozzles of magenta (M) and yellow (Y) are included in the third head 26-3. Row 47a is incorporated.

A portion (48-1, 48-2) of the plurality of divided ink nozzle row groups 47 is disposed with a position shift in (the forward direction of) the main scanning direction, and a portion (48).
-3, 48-4) are arranged in the sub-scanning direction so as to correspond to the divided ink nozzle row group 47 arranged in the main scanning direction, and form a 4-inch (1-line) color ink nozzle row group 46 as a whole. ing. That is, the plurality of divided ink nozzle row groups 47 are arranged in a zigzag pattern so that (a portion of the ink nozzles of) the ink nozzle rows 47a of the same color that are adjacent to each other in the sub-scanning direction are on the same line. Make up above.

As described above, since the ink nozzle row group 46 for one line is divided into four and the ink jet head 26 is constructed by incorporating the same, the defective ink jet head 26 is appropriately replaced, so that the head unit 24 is appropriately replaced. The yield can be improved.

By the way, the ink ejection timing of the ink jet head 26 is controlled by using the linear encoder 130. The linear encoder 130 may be a magnetic encoder, but an optical encoder is used here. The linear encoder 130 extends in the main scanning direction to form a plurality of slits 132 at predetermined intervals, and the linear scale 13 provided on the X-axis table frame 31.
1 and the head unit 2 facing the linear scale 131
4 and a linear sensor 133 provided in FIG. 4 to detect the moving position of the inkjet head 26 in the main scanning direction (see FIGS. 12 and 13).

As shown in FIG. 3, the linear scale 131 is made of a thin transparent film, and is attached to a thin scale support plate 135 mounted along the inner (front side) frame surface of the X-axis table frame 31, The back half is attached. The linear scale 131 has one end in the extending direction adhered, supported and fixed, and the other end pulled by a spring 136 to maintain its horizontal form. In addition, the plurality of slits 132 are provided in the front half portion that does not overlap with the adhered portion of the linear scale 131.
The light-transmitting portions and the light-shielding portions are arranged alternately at a predetermined interval along the main scanning direction.

The linear sensor 133 comprises a photo interrupter and is connected to the controller 11. That is, the linear sensor 133 has a light emitting element and a light receiving element facing each other, and the linear scale 131 (the plural slit 132 side portions thereof) is sandwiched between them with a predetermined gap (FIG. 13). reference). In this case, the linear scale 131 consists of a single unit, and the linear sensor 133
Are provided in the head unit 24.

Specifically, a plurality of linear sensors 133
Are provided in the head unit 24 so as to correspond to the plurality of divided ink nozzle row groups 47 displaced in the main scanning direction. That is, as shown in the schematic diagram of FIG. 6, since the number of divided ink nozzle row groups 47 arranged in the main scanning direction is two, two linear sensors 133 are provided separately. Then, the linear sensor 133 on the left side (backward side in the main scanning direction) detects the moving position of the two divided ink nozzle row groups 47 on the left side in the main scanning direction, and the linear sensor 133 on the right side (forward side in the main scanning direction). The linear sensor 133 detects the moving position of the two divided ink nozzle row groups 47 on the right side in the main scanning direction.

That is, a plurality of divided ink nozzle row groups 4
7 is individually managed by the corresponding linear sensor 133, and one linear sensor 133 also serves to detect the moving position of each divided ink nozzle row group 47 in the sub-scanning direction.
Each linear sensor 133 sequentially detects a plurality of slits 132 of the linear scale 131 as the head unit 24 moves in the main scanning direction, and outputs a pulsed detection signal corresponding to the pitch of the slits 132, respectively.
The positions of the left and right divided ink nozzle row groups 47 in the main scanning direction are detected based on these detection signals.

Further, each linear sensor 133 is arranged so as to be displaced in the main scanning direction by the amount of the displacement of each divided ink nozzle row group 47 in the main scanning direction. That is, each linear sensor 133 is disposed at an intermediate position of each corresponding divided ink nozzle row group 47, and the distance between the centers of the divided ink nozzle row groups 47 and the distance between the linear sensors 133 are the same. There is. Therefore, the distance between the linear sensors 133 is equal to the distance between the color ink nozzle rows 47 adjacent in the main scanning direction.
It matches the distance between the nozzle rows of a.

The two linear sensors 1 will be described in detail later.
By configuring 33 as described above, in printing one line on the printing tape A, the ink ejection drive of each ink nozzle row 47a of the divided ink nozzle row group 47 is set to the same detection point of the linear scale 131. It can be based on. As a result, it becomes possible to print an appropriate one line.

As shown in FIGS. 1 and 3, the support bracket 41 is located inside the lower end of the back plate 51 and the back plate 51 to which the above-mentioned female screw block is attached, and has a large opening for positioning and fixing the unified carriage 42. Horizontal plate 52
And a vertical plate 53, which is fixed by sandwiching the back plate 51 and the horizontal plate 52 from both left and right sides. That is, the back plate 51, the horizontal plate 52, both vertical plates 53, and the unified carriage 42 constitute a generally-known carriage.

A paper dust removing mechanism 43 is provided on the outer surface of each vertical plate 53, and the lower end outside (back side) of the back plate 51 is provided.
The pair of linear sensors 133 are attached to the lower end portion of the above so as to be separated from each other (see FIG. 13). In addition, a plurality of ink tubes 63 are provided on the back surface of the upper end of the support bracket 41.
A pipe support plate 66 for supporting the above is attached, and the Y-axis cable bear 39 is attached to the pipe support plate 66. It should be noted that reference numeral 59 in FIG. 1 denotes a cover attached from the front surface to the upper surface of the support bracket 41, and the upper surface of the cover 59 is opened corresponding to the plurality of ink tubes 63.

Next, the ink supply means 9 will be described. The ink supply unit 9 is provided on the shelf plate 14 and stores a large amount of each color ink, and the sub tank 62 that is provided on the base plate 13 and supplies each color ink from the main tank 61 to each inkjet head 26. And an ink tube 63 that connects the main tank 61, the sub tank 62, and the inkjet head 26. The main tank 61 pressurizes and supplies the ink to the sub tank 62, and the ink stored in the sub tank 62 receives the pump action (ink ejection) of the inkjet head 26 and is supplied thereto.

That is, the ink pressure-supplied from the main tank 61 is pressure-limbed in the sub-tank 62 and supplied to the ink jet head 26. In this case, the main tank 61 consists of one for each color,
The sub tank 62 is composed of two pieces of each color,
The ink in the main tank 61 repeats two-branching once before and after the sub-tank 62 by a two-branch joint provided in the ink tube 63, and the inkjet head 26
Of the ink nozzle row 47a.

More specifically with reference to FIG. 7, divided ink nozzle row groups 47 of six colors (K, C, LC, LM, M, and Y) are arranged side by side to form three ink jet heads 26.
In order to correspond to the four head groups 48 incorporated in the above, that is, two inkjet heads 26 each having a total of 12
In order to correspond to the four ink nozzle rows 47a, the main tank 61 is made up of a total of six, one for each color.
Consists of a total of 12 of each color. Although details will be described later, the piping for each color ink corresponds to the cleaning unit 123.

Next, the maintenance means 10 will be described. The maintenance means 10 includes a flushing box 121 for receiving the flushing ink, a storage unit 122 for storing the inkjet head 26 when it is not driven, and a cleaning for cleaning the inkjet head 26 by a manual operation or the like to eliminate nozzle clogging. It has a unit 123 and a wiping unit 124 for wiping the inkjet head 26 by a manual operation or the like.
In the upper part, it is provided in the vicinity of the X-axis table 27, which is separated from the tape feeding path 4 on the far side.

As shown in FIGS. 1 and 3, the flushing box 121 has its mounting position aligned with the origin (reference position) in the X-axis direction, and the back side thereof is located on the X-axis table 27.
Supported by. The flushing box 121 includes a box body 126 in the shape of a quadrangular frame having a bottom portion, an ink absorber 127 laid on the bottom portion of the box body 126, and an upper edge of the box body 126 to hold the four peripheral edge portions of the ink absorber 127. It has a frame-shaped pressing plate 128 fixed to the portion and faces the head unit 24 at the origin position in the X-axis direction so as to cover it from below. That is, all of the inkjet heads 26 that are located outside the printing area G and that face the origin position are included in the ink absorber 127.

The box body 126 is supported by the X-axis table frame 31 on the back side with a predetermined gap from the Y-axis table frame 32, and the right half portion is positioned so as to overlap with the Y-axis table 28. ing. Further, an ink storage portion 129 protruding downward from the box body 126 is provided in the left half portion of the box body 126, which is located on the left side of the Y-axis table 28. Then, the flushing ink ejected by the flushing is the ink absorber 12
When the ink is absorbed by 7 and becomes saturated, the ink reservoir 1
It flows down to 29.

The storage processing by the storage unit 122 is performed by sealing the nozzle forming surface of all ink jet heads 26,
Prevents ink evaporation. Similarly, in the storage process by the cleaning unit 123, the nozzle forming surface of each inkjet head 26 is sealed, and in this state, the ink is pumped from all the ink nozzles and the sucked ink is sucked through the tube to the waste ink tank 18. Leading to. The wiping process performed by the wiping unit 124 is performed by wiping off ink droplets attached around the ink nozzles of each inkjet head 26. By such a maintenance process, an appropriate meniscus of the ink nozzle can be held.

As shown in FIGS. 1 and 6, the cleaning operation and the wiping operation are performed by the third head after the processing of the first head group 48-1 and the second head group 48-2 is completed. Group 48-3 and fourth head group 4
The process 8-4 is performed. That is, cleaning and wiping of all the inkjet heads 26 are performed twice.

In this case, as shown in FIG. 7, each of the two head groups 48-1 and 48-2 facing one cleaning operation.
Ink of each color is connected to the group (48-3, 48-4). That is, the ink branched from one sub tank 62 is the first head group 48-1 and the second head group 48-2 (or the third head group 48-3).
And to the inkjet head 26 (ink nozzle row 47a) of the fourth head group 48-4).

As a result, the cleaning unit 123
In the suction operation (cleaning) from each inkjet head 26, the back flow of ink in the ink tube 63 can be prevented. For example, the first head group 48-1 and the third head group 4
When 8-3 and ink are sucked (cleaned) at the same time,
The ink of the second head group 48-2 is in the first head group 48-1, and the fourth head group 48-4 is in the third head group 48-3.
The ink will flow back.

Next, regarding tape feeding, the tape feeding means 7, the tape feeding means 6 and the tape winding means 8 will be described. FIG. 8 is a diagram schematically showing the tape feeding means 7, and as shown in FIG. 1 and FIG. 1, the tape feeding means 7 is a base plate 1 arranged at substantially the center of the tape feeding path 4.
3 is provided with a suction table 70, and a tape feeding mechanism 71 which is arranged with the suction table 70 interposed therebetween and which feeds the printing tape A along the tape feeding path 4.

The suction table 70 includes a housing 73 fixed to the base plate 13, a suction plate 74 attached to the upper surface of the housing 73, and three (a plurality) suction chambers formed below the suction plate 74. 75, and three suction fans (not shown) that face the lower part of each suction chamber 75, and suck the printing tape A by air. The suction plate 74 is formed to have a length (printing area) of 30 inches in the extending direction of the tape feed path 4 in accordance with the length of the X-axis table 27, and has the maximum width of the printing tape A.
It has a width corresponding to (tape width of 150 mm).

A large number of suction holes 76 communicating with the respective suction chambers 75 are formed on the upper surface of the suction plate 74, and the suction plate 74 does not float the printing tape A through the large number of suction holes 76. It is placed on the upper surface with a certain degree of attraction and a predetermined flatness. Also suction plate 7
Reference numeral 4 denotes a head unit 24 (inkjet head 26) that is horizontally arranged and moves immediately above it in the X and Y directions.
Parallel to. That is, the printing tape A adsorbed on the upper surface of the suction plate 74 faces the inkjet head 26 in parallel with a predetermined gap for ejecting ink.

As shown in FIGS. 1 and 8, the tape feeding mechanism 71 includes a tape feeding roller 81 disposed on the base plate 13 on the downstream side of the tape feeding path 4 and a tape feeding roller 8.
1, a tape feed motor 82 for rotationally driving the feed roller 1, a feed roller 83 arranged downstream of the tape feed roller 81 in the feed direction and feeding out to the tape winding means 8, and a suction table 70 at the immediate downstream side and upstream side in the feed direction. The guide roller 84 and the feeding roller 85 arranged in the immediate vicinity, the guide roller 86 arranged on the upstream side in the feeding direction of the feeding roller 85, and the width guide portion 8 arranged on the upstream side in the feeding direction of the guide roller 86.
7 and 7.

Further, the tape feeding mechanism 71 includes an intermediate roller 88 and an intermediate roller 88 on the downstream side in the feeding direction of the guide roller 84 between the base plate 13 and the shelf plate 14 between the tape feeding roller 81 and the guide roller 84. And a lower roller 89 disposed below. A space between the lower roller 89 and the guide roller 84 is a drying area which has a length substantially the same as the printing area G and in which the printed portion of the printing tape A is naturally dried.

The tape feed roller 81 is the controller 1
The rotation of the head unit 24 is controlled by 1 so as to rotate in synchronization with the head unit 24 so that the entire tape feeding and stopping of the machine base 2 including the feeding on the suction table 70 can be performed with high accuracy. Specifically, printing tape A
The detection mark E printed together with the unit image B is detected, the tape feed roller 81 is rotated based on the calculated step number, and the feeding of the print tape A is stopped.

A tape feed sensor 92 is disposed on the intermediate support plate 91 that supports the intermediate roller 88 at a position facing the tape feed path 4 (printing tape A) and parallel to the intermediate roller 88. The tape feed sensor 92 is connected to the controller 11, and the tape feed sensor 92 detects the detection mark E of the printing tape A.
The drive operation of the tape feed motor 82 is controlled based on the detection result. Thereby, the feeding of the printing tape A, that is, the intermittent feeding in units of the unit printing area C where printing is performed by the printing operation of one tact is performed with high accuracy.

In this case, the tape feed sensor 92 is located at a predetermined distance (specified distance: M) from the tip of the printing area G. Then, one detection mark E printed on the unit print area C is printed at a position that is lower than the specified distance from the rear end of the unit print area C to the downstream side in the tape feeding direction. That is, the distance from the rear end of the unit print area C to the printing position of the detection mark E and the distance from the front end of the unit print area C to the position of the tape feed sensor 92 are set to be the same, and thus the high accuracy described above is achieved. Achieves excellent tape feeding.

The width guide portion 87 is provided with five feed members for guiding the feeding of the printing tape A, and the printing tape A fed through the width guide portion 87 is subjected to a corrugated route change to the guide roller 86. Will be sent. Further, the width guide portion 87 is configured such that the width of the feeding path can be changed with the end on the back side as a fixed position, corresponding to the printing tape A of each width.
As a result, each printing tape A is fed at the end on the back side in the width direction as a fixed position (reference to the end face) and faces the suction table 70.

The tape supply means 6 is, as shown in FIG.
A pair of front and rear supply support frames 101 fixed to the base plate 13 facing the width guide portion 87, and a bracket 1 fixed to the angle member 12 of the machine base 2 below the supply support frame 101.
And 02 together form a supporting portion, and a predetermined amount of slack is given to the printing tape A that is fed and supplied to the tape feeding means 7 (width guide portion 87). The bracket 102 is provided with a feeding reel 103 which is wound in a roll shape and rotatably supports the printing tape A, and a torque limiter 104 axially attached to the feeding reel 103.

On the other hand, the tape take-up means 8 includes a tape take-up reel 105 which is rotatably supported by the finisher main body 20, a take-up roller 106 located immediately above the tape take-up reel 105, and a take-up roller 106. A winding motor 107 for rotating the roller, a winding guide roller 108 that is close to the winding roller 106 and faces the winding roller 106, a width restricting portion 109 that restricts the width direction of the printed printing tape A, a finisher 3 and a machine. The pressing roller 110 is located between the table 2 and the table 2.

Then, the printed printing tape A fed from the tape feeding means 7 is guided to the width regulating portion 109 via the pressing roller 110, and here, the width guide at the time of winding the tape is performed. , Tape take-up reel 105
It is rolled into a roll.

Image printing will be described with reference to FIGS. 1 and 9. In the inkjet printer 1, the tape feeding means 7 is driven after the tape feeding means 6 to feed the portion of the printing tape A to be printed, that is, the unit printing area C onto the suction table 70 which is the printing area G. In this state, the suction table 70 is driven, and the unit print area C of the printing tape A, which has stopped feeding, is sucked by the suction table 70 and is held immovably. Subsequently, the X / Y moving mechanism 25 is driven to move the head unit 24 in the main scanning direction and the sub scanning direction, and ink is ejected from each inkjet head 26 of the head unit 24 to print an image. .

During this printing operation, the paper dust removing mechanism 43 is in a driving state and flushing is appropriately performed. Further, the ink ejection drive from the inkjet head 26 is performed based on the movement position information of the inkjet head 26 by the linear encoder 130, but is appropriately performed by detecting the movement position of the divided ink nozzle row group 47 unit. (Described later).

In printing an image, a plurality of label portions as the unit image B are separated from each other with a gap (non-printed portion Ab),
Printing is performed continuously, and a desired number of unit images B are printed on the printing tape A by repeating printing and feeding of the printing tape A. Also, with this unit image B,
A detection mark E for indicating the feed amount of the unit print area C,
An image position mark D for indicating the position of each unit image B is printed.

The unit print area C is a portion where the unit image B is printed (image print area AB) and a portion which is located outside the image print area AB and where the detection mark E and the image position mark D are printed (mark print area). AC) and are set.
The detection mark E is printed at a position of a specified distance M from the rear end of the unit print area C in the mark print area AC. Further, the image position mark D is a mark in the mark print area AC.
Corresponding to each unit image B, it is printed in the vicinity immediately above.

The length of the unit print area C can be changed to any length according to the print contents such as the size of the image to be printed, but the maximum length is 30 inches corresponding to the print area G. Specifically, when the print content is determined, the print tape A
The length of the unit print area C in the 1-tact printing operation is determined, and then the print position of the detection mark E in the unit print area C becomes the specified distance M from the rear end of the unit print area C. Is set to.

Then, the unit image B in the unit print area C,
When the printing of the detection mark E and the image position mark D is completed, the X / Y moving mechanism 25 is stopped, and then the tape feeding means 7 is driven to feed the printed unit printing area C, and the tape feeding sensor 92 is used. This feeding is controlled based on the detection result of the detection mark E, and the next unit printing area C is introduced onto the suction table 70. Here, the XY moving mechanism 25 is driven again to move the head unit 24 in the main scanning direction and the sub-scanning direction toward the original print start position P1 (see FIG. 4), and ink is ejected to form an image. (Unit image B, detection mark E and image position mark D)
Is printed.

As described above, the print tape A is held on the suction table 70, and the printing of one unit printing area C and the next unit printing area C are performed by the main scanning and the sub scanning of the head unit 24. Since the feeding to the suction table 70 is repeated to print an arbitrary number of labels on the long printing tape A, it is possible to perform printing at the dot level with high accuracy.

In the above embodiment, the head unit 24 is moved to the original print start position by the XY moving mechanism 25 while the print tape A is being fed, and printing is always started from the print start position P1. You may do it.
Further, the printing may be performed on the printing tape A only when the head unit 24 is moved rightward in the main scanning direction, that is, only when the head unit 24 is moved in the forward direction.

Next, the main control system constituted by the controller 11 will be described. As shown in the block diagram of FIG. 10, the control system of the inkjet printer 1 has an input unit 141 that reads image data created by an external device such as a personal computer by the operation and a printing unit 5, and prints on the printing tape A. A printing unit 142 that prints an image, a maintenance unit 143 that includes the maintenance unit 10 that performs a maintenance process for the inkjet head 26, and an ink supply unit 144 that includes the ink supply unit 9 and supplies ink to the inkjet head 26. And tape supply means 6 and tape winding means 8
Also, a transport unit 145 that has the tape feeding unit 7 (tape feeding motor 82) to feed the printing tape A, a driving unit 146 that has various drivers for driving each unit, a tape feeding sensor 92 of the tape feeding unit 7, and two The linear sensor 133 includes a detection unit 147 that performs various detections, and a control unit 148 (controller 11) that controls each unit of the inkjet printer 1.

The control unit 148 includes a CPU 151 and a ROM 1
52, RAM 153 and P-CON 154, which are connected to each other via a bus 155. The ROM 152 has a control data area for storing various control data such as a character table and a color conversion table, as well as a control program area for storing a control program processed by the CPU 151. The RAM 153 is an image data area for storing image data input from the outside,
In addition to a print image data area that stores image data for printing, a feed amount data area that stores feed amount data for tape feed, a color conversion buffer area and various register groups corresponding to each color, and control processing Used as a work area for.

The P-CON 154 has a logic circuit for complementing the function of the CPU 151 and for handling interface signals with peripheral circuits, including a gate array and a custom LS.
It is configured and incorporated by I or the like. For this reason,
The P-CON 154 is connected to a keyboard of a personal computer and the like, and various commands and image data from the input unit 141 are directly or processed and taken into the bus 155.
In conjunction with the CPU 151, the CPU 151 etc.
The data and the control signal output to 5 are directly or processed and output to the drive unit 146.

Then, the CPU 151 has the above-described configuration and operates in accordance with the control program stored in the ROM 152.
After inputting various detection signals, various commands, various data and the like through the ON 154 and processing various data and the like in the RAM 153, the control signal is output to the drive unit 146 through the P-CON 154. As a result, the printing unit 5, the tape feed motor 82, etc. are controlled, and the inkjet printer 1 as a whole is controlled by performing image printing and tape feed on the printing tape A under predetermined printing conditions and tape feeding conditions.

For example, in the CPU 151, when the head unit 24 moves, it receives a pulse (detection signal) output from the two linear sensors 133 that move with it, and counts up each time the pulse is received. Each count value becomes a movement position of each divided ink nozzle row group 47 mounted on the head unit 24 in the main scanning direction, that is, a movement position of each ink nozzle row 47a of each divided ink nozzle row group 47. And CPU
151 drives the inkjet head 26 based on the movement position information, and ejects ink from a predetermined nozzle of the ink nozzle row 47a to a predetermined position of the printing tape A. The two linear sensors 133 can appropriately print one line.

11 and 12 schematically show the ejection principle of the ink jet head 26 of the prior art and this embodiment. A broken line LL extending in the front-rear direction shown in both figures
Indicates a certain line to be printed on the printing tape A. Further, the head unit 24 shown by the phantom line shows a state in which the head unit 24 shown by the solid line has moved a predetermined distance to the forward direction side in the main scanning direction. For the sake of explanation, the phantom line head unit is shown on the front side.

In the conventional device shown in FIG. 11, one linear sensor 13 arranged at an intermediate position of the head unit 24 is used.
3, the ink jet heads 26 of all the divided ink nozzle row groups 47 are driven to be ejected. Therefore,
For example, when ejecting yellow (Y) ink on the broken line LL, the right divided ink nozzle row group 47 (48-
2, 48-4) yellow (Y) ink nozzle rows 4
7a, based on the count value until the linear sensor 133 reaches the detection point P1 on the left side in the drawing, on the other hand, the left divided ink nozzle row group 47 (48-1, 48)
For each yellow (Y) ink nozzle row 47a of -3), the linear sensor 133 performs the count based on the count value from the detection point P1 to the detection point P2 on the right side in the drawing.

Therefore, when the accuracy of the linear scale 131 between the detection point P1 and the detection point P2 is poor, that is, because the linear scale 131 is attached in an improper posture, the detection point (P1
-P2) slit 1 of linear scale 131
When the 32 intervals have unequal pitches, an error occurs in the count value between the left and right depending on this.
Therefore, as described above, an error occurs in the ink ejection timing in the left and right divided ink nozzle row groups 47, and one printed line is misaligned stepwise.

On the other hand, in the present embodiment shown in FIG. 12, two linear sensors 133 are provided in the head unit 24.
Are arranged so as to be separated from each other by the distance between the left and right ink nozzle rows 47a of the same color (see FIG. 6), and the ejection drive of the inkjet head 26 is independently performed by the left and right divided ink nozzle row groups 47. Therefore, for example, when ejecting yellow (Y) ink on the broken line LL, the yellow (Y) ink nozzle rows 47a of the divided ink nozzle row group 47 (48-2, 48-4) on the right side are ejected. If so, based on the count value until the right linear sensor 133 reaches the detection point P3, similarly, the yellow (Y) color of the left divided ink nozzle row group 47 (48-1, 48-3)
In each of the ink nozzle rows 47a, it can be performed based on the count value until the left linear sensor 133 reaches the detection point P3.

Therefore, in the printing of one line on the broken line LL, since the ink ejection drive of the left and right divided ink nozzle row groups 47 can be based on the count value up to the same detection point P3, the accuracy of the linear scale 131 can be improved. Regardless of this, even if the plurality of ink nozzle rows 47a forming one line are displaced in the main scanning direction, one line can be appropriately printed.

The ink ejection timing of each color ink nozzle row 47a in one divided ink nozzle row group 47 is determined by the ink jet heads 26 (26-1, 26-2, 26-3) forming the ink nozzle row 47a. Is properly assembled to the partial carriage 44, the nozzle row distance of each color ink nozzle row 47a is taken into consideration.
This can be easily performed by adjusting the ejection timing counter and the timer control process.

Further, in this embodiment, the divided 4
The divided ink nozzle row groups 47 are arranged in a zigzag pattern to
Although the line ink nozzle row group 46 is formed, the arrangement is not limited to this arrangement. For example, the divided ink nozzle row group 47
May be arranged side by side in the main scanning direction in a stepwise manner to form an ink nozzle row group 46 of one line. In this case,
By the number of divided ink nozzle row groups 46 arranged side by side in the main scanning direction,
The linear sensor 133 is arranged corresponding to this.

The number of divided ink nozzle row groups 47, the number of partial carriages 44, and the number of ink jet heads 26 mounted on one partial carriage 44 are not limited to those in the embodiment and can be changed as appropriate. . Therefore, for example, when a plurality of ink jet heads 26 in which a plurality of ink nozzle rows 47a of one color used for printing one line are displaced in the main scanning direction are arranged in the head unit 24, the plurality of ink jet heads Ink nozzle row 4
7a may be provided with a plurality of linear sensors 133, and the plurality of linear sensors 133 may be arranged with a positional deviation in the main scanning direction by an amount corresponding to the positional deviation of the ink nozzle rows 47a.

[0090]

According to the ink jet printer of the present invention, a plurality of linear sensors are provided in the head unit, and the nozzle row distance between the ink nozzle rows that are adjacent in the main scanning direction,
The linear sensor distances of the corresponding linear sensors are configured to be the same, and the moving position of each ink nozzle row in the main scanning direction is individually detected by each corresponding linear sensor. Therefore, in one-line printing, the ink ejection drive of each ink nozzle row can be based on the same detection point on the linear scale, so that the print quality can be appropriately maintained.

[Brief description of drawings]

FIG. 1 is an external perspective view of an inkjet printer according to an embodiment of the present invention.

FIG. 2 is an external perspective view from the back side showing the inkjet printer according to the embodiment with a part thereof omitted.

FIG. 3 is a plan view showing an area around a printing unit.

FIG. 4 is an explanatory diagram showing a movement operation of a head unit.

FIG. 5 is an external perspective view of a head unit.

FIG. 6 is a schematic view of a head unit structure.

FIG. 7 is a piping system diagram of an ink supply system.

FIG. 8 is a cross-sectional view of tape feeding means.

FIG. 9 is an explanatory diagram of a printing result on a printing tape.

FIG. 10 is a block diagram of a control system of the inkjet printer according to the embodiment.

FIG. 11 is an explanatory diagram schematically showing the ejection principle of a conventional inkjet head.

FIG. 12 is an explanatory diagram schematically showing the ejection principle of the inkjet head of the present embodiment.

FIG. 13 is a side view showing the periphery of the head unit.

[Explanation of symbols]

1 inkjet printer 2 units 3 finisher 4 Tape feed route 5 Printing means 6 Tape supply means 7 Tape feeding means 8 Tape winding means 9 Ink supply means 10 Maintenance means 24 head units 25 XY movement mechanism 26 inkjet head 42 Unified carriage 44 partial carriage 46 ink nozzle row group 47 division ink nozzle row group 47a ink nozzle row 130 linear encoder 131 Linear scale 133 linear sensor

   ─────────────────────────────────────────────────── ─── Continued front page    F term (reference) 2C056 EA07 EB07 EB36 EC35 EC37                       FA11                 2C480 CA36 CB35

Claims (4)

[Claims] 1. An ink jet printer comprising a plurality of ink jet heads in which a plurality of ink nozzle rows used for printing one line are displaced in the main scanning direction, the plurality of ink jet heads being mounted on a carriage. A head unit; a moving mechanism that moves the head unit in the main scanning direction; a linear encoder that detects a moving position of the inkjet head in the main scanning direction; and a moving mechanism based on position information of the linear encoder. And a control unit for controlling the ink ejection drive of each of the inkjet heads, wherein the linear encoder is a single linear scale extending in the main scanning direction, and the plurality of inks facing the linear scale. The head unit corresponding to the nozzle row Consists of a plurality of linear sensors provided, the plurality of linear sensors, ink jet printer, characterized in that the positional shift amount of a plurality of ink nozzle arrays are arranged at a position displaced in the main scanning direction. 2. An ink nozzle row group having a plurality of ink nozzle rows used for printing one line for each ink color is divided into a plurality of divided ink nozzle row groups for each ink color in the line direction, and the plurality of divided ink nozzle row groups are divided. An ink jet printer comprising a plurality of ink jet heads in which a group of divided ink nozzle rows is displaced in the main scanning direction, wherein a head unit in which the plurality of ink jet heads are mounted on a carriage, and the head unit is arranged in the main scanning direction. A moving mechanism for moving the inkjet head, a linear encoder for detecting a moving position of the inkjet head in the main scanning direction, and drive of the moving mechanism and ink ejection driving of each inkjet head based on position information of the linear encoder. And a control means for controlling the linear encoder, A single linear scale extending in the main scanning direction, and a plurality of linear sensors facing the linear scale and provided in the head unit corresponding to the plurality of divided ink nozzle row groups, The inkjet printer is arranged such that the linear sensor is displaced in the main scanning direction by a displacement of the plurality of divided ink nozzle row groups. 3. The plurality of divided ink nozzle row groups are mounted on the carriage in a staggered manner, and the ink nozzle rows adjacent to each other in the line direction are each formed on the same line. The inkjet printer according to claim 2. 4. The moving mechanism mounts the head unit and moves the head unit in the main scanning direction, and an X-axis table that moves the head unit in the line direction via the X-axis table. An axis table, and the linear scale is provided on a frame of the X-axis table.
The inkjet printer described in 1.