JP2004136555A - Printer having adjustable securing position of print head to carriage - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To eliminate positional shift in the subscanning direction of each dot being formed of a plurality of dot forming elements. <P>SOLUTION: The carriage 1 of the printer comprises first adjusting parts 83, 86 and 87 to secure a print head onto the carriage at different positions in a direction intersecting the main scanning direction, and second adjusting parts 82, 84 and 85 to secure the print head onto the carriage at different rotational angles about an axis extending in the direction intersecting a plane defined by a part of the recording medium facing the print head. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a printing apparatus that forms an image by forming dots on printing paper using a plurality of dot forming elements, and in particular, relates to a technique for eliminating positional displacement of dots formed by each dot forming element in the sub-scanning direction. .
[0002]
[Prior art]
2. Description of the Related Art In recent years, inkjet printers have become widespread as image printing apparatuses. In an ink jet printer, a print head having a large number of nozzles is fixed on a carriage. Then, the carriage is reciprocated at a position facing the printing paper, and while main scanning is performed, ink droplets are ejected from nozzles to form dots on the printing paper. When the formation of dots in the main scanning direction is completed at a certain position on the printing paper, the printing paper is fed to form dots at another position. In such a printing apparatus, when the dot formation position is shifted from the assumed position at the time of design, the shift can be resolved by shifting the dot formation timing in the main scanning direction (for example, Patent Document 1).
[Patent Document 1]
JP 2000-296648 A
[0003]
[Problems to be solved by the invention]
However, the deviation of the dot formation position in the printing paper feed direction (sub-scanning direction) cannot be solved by shifting the dot formation timing. Conventionally, there has not been enough devised to eliminate such a shift in the dot formation position in the sub-scanning direction.
[0004]
The present invention has been made in order to solve the above-described problems in the related art, and in a printing apparatus that forms an image by forming dots on printing paper with a plurality of dot forming elements, The purpose is to eliminate the displacement.
[0005]
[Means for Solving the Problems and Their Functions and Effects]
In order to solve at least a part of the above problems, in the present invention, a predetermined process is performed on a printing apparatus that prints an image by forming dots on a print medium. This printing apparatus moves a dot recording head provided with a plurality of dot forming elements for forming dots on a printing medium, a carriage provided with the dot recording head, and at least one of the carriage and the printing medium. A main scanning drive section for performing main scanning, and a control section for controlling the dot recording head and the main scanning drive section.
[0006]
The carriage of the printing apparatus includes a first adjustment unit that can fix the print head on the carriage at a different position in a direction intersecting with the main scanning direction, and a print head on the carriage and a print head of the print medium. A second adjustment unit that can be fixed at a different rotation angle about a direction intersecting a plane formed by the facing parts as an axis. With such an embodiment, it is possible to adjust the dot formation position shift in a direction different from the main scanning direction.
[0007]
It is preferable that the carriage further includes a third adjustment unit that can fix the print head on the carriage by changing a distance between a portion of the print medium facing the print head and the print head. With such an embodiment, the distance between the print head and the print medium can be adjusted.
[0008]
Further, when the carriage has a plurality of print heads, and the first and second adjustment units are provided at least one each for one print head, the printing apparatus is configured as follows. It is preferable to adopt a mode. That is, it is preferable that the printing apparatus is provided so as to be relatively movable with respect to the plurality of print heads, and is provided with an adjustment drive unit that can drive the first and second adjustment units. Further, it is preferable that the number of the adjustment drive units is smaller than the number of the print heads. In such an aspect, the adjustment drive unit can move relatively to the plurality of print heads, so that a relatively large number of print heads can be adjusted with a relatively small number of adjustment drive units.
[0009]
It is preferable that the adjustment drive unit can move in a direction intersecting with the main scanning direction independently of the carriage. With such an embodiment, the adjustment drive unit can be moved two-dimensionally relative to the carriage by a simple mechanism.
[0010]
Preferably, the first adjusting section includes a first shaft section which can be rotated to change the position of the print head in a direction intersecting with the main scanning direction, and the second adjusting section. Preferably has a second shaft portion that can change the rotation angle of the print head by being rotated. Preferably, the directions of the rotation axes of the first and second shaft portions are both perpendicular to the main scanning direction and the moving direction of the adjustment drive unit. With such an embodiment, the adjustment drive unit can easily drive each adjustment unit without interfering with the carriage and the print head.
[0011]
Further, when the plurality of dot forming elements include two or more dot forming elements provided at different positions in a direction intersecting with the main scanning direction, it is preferable to adopt the following mode. That is, the printing apparatus preferably includes a sensor that can read an image recorded on a print medium. In such a printing apparatus, while performing main scanning, dots are formed on the printing medium by the two or more dot forming elements, and are located at different positions in a direction intersecting with the main scanning direction. The two or more inspection patterns extending in the direction of are printed.
[0012]
After that, two or more inspection patterns are read by the sensor. Then, based on the data of the two or more inspection patterns read by the sensor, at least one of the set value of the position in the direction intersecting with the main scanning direction of the print head and the set value of the rotation angle is determined. The adjustment driving unit drives the adjustment unit according to the set value. With such an embodiment, the print head can be adjusted according to the actual printing result.
[0013]
Further, when the plurality of dot forming elements include two or more dot forming element rows provided along a direction intersecting with the main scanning direction, the following mode can be adopted. That is, dots are formed on the print medium at the same timing using the dot forming elements included in each dot forming element row, and the inspection pattern is printed for each dot forming element row. Then, the inspection pattern is read by the sensor. Thereafter, based on the data of the inspection pattern read by the sensor, at least one of a set value of a position in a direction intersecting with a main scanning direction of the print head and a set value of a rotation angle are determined. Even in such an embodiment, the print head can be adjusted according to the actual printing result.
[0014]
The adjustment of the print head is preferably performed in the following order. That is, first, the mounting angle of the print head on the carriage is adjusted with the direction intersecting the plane intersecting with the plane formed by the portion of the print medium facing the print head as an axis. Then, the mounting position of the print head on the carriage in the direction intersecting with the main scanning direction is adjusted. After that, the dot forming timing by each dot forming element is adjusted. With such an embodiment, it is possible to efficiently eliminate the intervals and positions in the sub-scanning direction and the positional deviation in the main scanning direction of the dots formed by the dot forming elements.
[0015]
The present invention can be realized in various forms. For example, a printing method and a printing apparatus, a printing control method and a printing control apparatus, a computer program for realizing the functions of these methods or apparatuses, The present invention can be realized in the form of a recording medium on which a computer program is recorded, a data signal including the computer program, and embodied in a carrier wave.
[0016]
BEST MODE FOR CARRYING OUT THE INVENTION
Next, embodiments of the present invention will be described in the following order based on examples.
A. Equipment configuration:
A1. Configuration of the whole printer:
A2. Configuration of head base unit and head adjustment drive unit:
A3. Configuration of control unit:
B. Adjusting the print head:
B1. Refilling ink during print processing:
B2. Refilling ink between printing images:
C. Second embodiment:
D. Third embodiment:
E. FIG. Modification:
E1. Modification 1
E2. Modified example 2:
E3. Modification 3:
E4. Modification 4:
E5. Modification 5:
E6. Modification 6:
[0017]
A. Equipment configuration:
A1. Configuration of the whole printer:
FIG. 1 is a perspective view schematically showing the configuration of a printer 200 as one embodiment of the present invention. The printer 200 is a printer corresponding to relatively large printing paper P such as, for example, JIS-standard A row 0 paper, B row 0 paper, or roll paper. The printing paper P is supplied from the paper supply unit 210 to the printing unit 220. The printing unit 220 performs printing by discharging ink onto the supplied printing paper P. The printing paper P printed by the printing unit 220 is discharged to the paper discharge unit 230.
[0018]
The paper feeding unit 210 includes a roll paper holder 211 on which roll paper as the printing paper P can be set. The roll paper holder 211 includes a spindle 212 for holding roll paper, and a first spindle receiver 213 and a second spindle receiver 214 on which the spindle 212 can be attached and detached and suspended. The two spindle receivers 213 and 214 are respectively provided on two support columns 215 provided on the upper part of the printer 200. After the roll paper is mounted at the center of the spindle 212, both ends are mounted on the first spindle receiver 213 and the second spindle receiver 214.
[0019]
The paper discharge unit 230 includes a take-up holder 231 that can take up roll paper. The winding holder 231 includes a spindle 232 for winding the roll paper printed by the printing unit 220, and a first spindle receiver 233 and a second spindle receiver 234 on which the spindle 232 can be attached and detached and suspended. The two spindle receivers 233 and 234 are provided on two support columns 235 provided at the lower part of the printer 200, respectively. The spindle 232 has both ends mounted on a first spindle receiver 233 and a second spindle receiver 234, and is rotatable by driving means (not shown). Note that a configuration in which the spindle 212 is rotated by a driving unit to wind up the printing paper P may be adopted. Further, as described later, a paper feeding unit such as a paper discharging roller may be provided in the printing unit 220, and the printing paper P may be discharged by driving the paper feeding unit.
[0020]
On the upper surface of the printing unit 220, an input / output unit 240 is provided as an input unit capable of inputting a print mode or the like.
[0021]
FIG. 2 is an explanatory diagram illustrating the configuration of the printing unit 220. The printing unit 220 has the carriage 1 on which a plurality of print heads (described later) are installed. The carriage 1 has a plurality of sub-tank sets 3S for temporarily storing ink used by the print head. The carriage 1 is connected to a drive belt 101 driven by a carriage motor 100, and is guided by a main scanning guide member 102 and can move in the main scanning direction MS. The carriage motor 100, the driving belt 101, and the main scanning guide member 102 correspond to a "main scanning driving unit" in the claims.
[0022]
A first inspection unit 10A and a second inspection unit 10B for performing a nozzle ejection inspection are provided at both ends of the printing paper P in the movement range of the carriage 1 in the main scanning direction. A wiper unit 30 for wiping the nozzles, a cap unit 20 for sealing and cleaning the nozzle group, and a main tank 9 for supplying ink to the sub tank set 3S are provided beside the second inspection unit 10B. Have been.
[0023]
Further, a head adjustment drive unit 70 is provided between the wiper unit 30 and the cap unit 20. The head adjustment drive unit 70 is a shaft member provided at a position farther from the printing paper than the space through which the carriage 1 passes, and is slidable on a slide shaft 71 provided in the transport direction of the printing paper P. It is provided in. A transport motor 72 is provided near one end of the slide shaft 71, and a pulley 73 is provided near the other end of the slide shaft 71. An endless drive belt 74 is stretched parallel to the slide shaft 71 between the transport motor 72 and the pulley 73, and the head adjustment drive unit 70 is attached to the drive belt 74. As a result, when the transport motor 72 moves the drive belt 74, the head adjustment drive unit 70 moves on the slide shaft 71 in the transport direction of the printing paper P. The detailed configuration of the head adjustment drive unit 70 will be described later.
[0024]
When printing is performed, the carriage 1 performs printing by discharging ink from the nozzles onto the printing paper P while moving in the main scanning direction at a position facing the printing paper P. When printing is not performed, the carriage 1 moves to a position facing the cap unit 20.
[0025]
The sub tank set 3S and the main tank 9 are connected by an ink supply path 103. In this embodiment, there are six types of sub-tanks 3a to 3f of black K, cyan C, light cyan LC, magenta M, light magenta LM, and yellow Y, which are respectively connected to the corresponding six main tanks 9a to 9f. Have been. In the following, each configuration and function of the printer will be described using the sub tanks 3a to 3f and the main tanks 9a to 9f. In the case where it is not necessary to distinguish the ink colors, the sub tank is described as the sub tank 3. The main tank will be described as a main tank 9.
[0026]
The available inks are not limited to six types, but four types of inks (for example, black K, cyan C, magenta M, and yellow Y) and seven types of inks (for example, black K, light black LK, and cyan C). , Light cyan LC, magenta M, light magenta LM, yellow Y) can also be used. The types of ink that can be used can be determined according to the needs of the user.
[0027]
FIG. 3 is an explanatory diagram showing the arrangement of nozzles on the lower surface of one print head 6. The print head 6 has three nozzle plates 2a, 2b, 2c. Two nozzle groups capable of discharging different inks are provided on the lower surface of one nozzle plate, and the print head 6 as a whole has six nozzle groups. In this embodiment, different inks are assigned to the respective nozzle groups. However, the same ink may be ejected from a plurality of nozzle groups.
[0028]
FIG. 4 is an explanatory diagram illustrating a schematic configuration of the carriage 1. In this embodiment, a total of 17 print heads 6 are arranged on the carriage 1. Each print head is provided at a different position in the sub-scanning direction SS. The nozzles of black K, cyan C, light cyan LC, magenta M, light magenta LM, and yellow Y provided on the 17 print heads 6 (see FIG. 3) are within the range indicated by the arrow Ap. Are arranged at equal intervals in the sub-scanning direction SS. Therefore, this printer can print a relatively large area at a time, and can print at a high speed even when a relatively large printing paper is used.
[0029]
A2. Configuration of head base unit and head adjustment drive unit 70:
FIG. 5 is a plan view showing the head base unit 80. The head base unit 80 is a component to which one print head 6 is mounted and which is mounted on the carriage 1. That is, the 17 print heads 6 provided on the carriage 1 are respectively attached to the carriage 1 via the head base unit 80. The head base unit 80 has a fixed base unit 81, a rotating base unit 82, and a slide base unit 83.
[0030]
The fixed base unit 81 has four corners fixed to the carriage 1 by screws 81a, and is attached to the carriage 1. The rotating base unit 82 is mounted on the fixed base unit 81 so as to be rotatable about a shaft 82a.
The shaft 82a is provided in a direction perpendicular to the plane of the printing paper at a position facing the print head. The rotation base unit 82 is rotatable by 5 degrees left and right about the axis 82a as indicated by an arrow A2.
[0031]
A cam 84 is provided on the fixed base unit 81. The cam 84 is rotatable about a shaft 84a provided in parallel with the shaft 82a. One end of the cam 84 is in contact with the rotation base unit 82, and as shown by broken lines and arrows A4 and A2 in FIG. change. The shaft 84a corresponds to a “second shaft” in the claims.
[0032]
A projection 81b is provided on the fixed base unit 81, and a spring 85 is attached to the projection 81b. The spring 85 is in contact with the rotation base unit 82 on the side opposite to the side where the cam 84 is in contact, and presses the rotation base unit 82 against the cam 84. In order to rotate the cam 84, a force larger than the force of the spring 85 is required. Therefore, the cam 84 is pressed by the spring 85 via the rotation base unit 82, but is not rotated by the force of the spring 85. The rotation base unit 82, the shaft 82a, the cam 84, and the spring 85 correspond to a "second adjustment unit" in the claims.
[0033]
On the rotation base unit 82, slide pins 82b and 82c are provided. The slide pins 82b and 82c are arranged in a direction substantially perpendicular to the transport direction of the carriage 1 with the fixed base unit 81 attached to the carriage 1.
[0034]
The slide base unit 83 has slide grooves 83b and 83c. The slide grooves 83b and 83c are rectangular holes, and are penetrated by the slide pins 82b and 82c, respectively, in a state where the slide base unit 83 is attached to the rotation base unit 82. The slide base unit 83 is slidably mounted on the rotation base unit 82 by the slide grooves 83b and 83c and the slide pins 82b and 82c. The sliding direction of the slide base unit 83 is substantially perpendicular to the transport direction of the carriage 1 in a state where the fixed base unit 81 is attached to the carriage 1.
[0035]
A cam 86 is provided on the rotation base unit 82. As shown in FIG. 5, the shaft 86a is provided on the same line as the line on which the slide grooves 83b and 83c are arranged. The cam 86 is rotatable about a shaft 86a provided in parallel with the shaft 82a. The shaft 86a corresponds to a "first shaft" in the claims. One end of the cam 84 is in contact with the slide base unit 83, and the slide base unit 83 moves on the rotation base unit 82 in accordance with the rotation angle of the cam 86, as shown by a dashed line and arrows A 6 and A 3 in FIG. Slide.
[0036]
A projection 82d is provided on the fixed base unit 81, and a spring 87 is attached to the projection 82d. The spring 87 is in contact with the slide base unit 83 on the side opposite to the side where the cam 86 is in contact, and presses the slide base unit 83 against the cam 86. In order to rotate the cam 86, a force larger than the force of the spring 87 is required. For this reason, the cam 86 is pushed by the spring 87 via the slide base unit 83, but is not rotated by the force of the spring 87. The slide base unit 83, the slide pins 82b and 82c, the cam 86, and the spring 87 correspond to a “first adjustment unit” in the claims.
[0037]
The slide base unit 83 has a through hole 83a. The print head 6 is attached to the through hole 83a of the slide base unit 83. Although not shown, the fixed base unit 81 and the rotary base unit 82 are also provided with through holes at positions overlapping the through holes 83a in FIG. The through hole provided in the rotating base unit 82 is larger than the through hole 83a, and the through hole provided in the fixed base unit 81 is larger than the through hole provided in the rotating base unit 82. As a result, in a state where the print head is attached to the through hole 83a, the surface of the print head 6 where the nozzle row is provided directly faces the printing paper through these through holes.
[0038]
With the above configuration, the print head 6 attached to the through hole 83a of the slide base unit 83 can slide on the carriage 1 along the slide grooves 83b and 83c, and can rotate about the shaft 82a. It is.
[0039]
FIG. 6 is an explanatory view of the carriage 1 as viewed from the rear side. FIG. 6 also shows the head adjustment drive unit 70 and the slide shaft 71. As shown in FIG. 6, a total of 17 print heads 6 mounted on the head base unit 80 (see FIG. 5) are mounted on the carriage 1. Note that an optical sensor 1a is provided on the carriage 1. The optical sensor 1a can read an image printed on printing paper.
[0040]
FIG. 7 is an explanatory diagram showing the head adjustment drive unit 70, the head base unit 80, and the print head 6. The head adjustment drive unit 70 includes an adjustment motor 70b connected to a rotation shaft 70a, and an adjustment motor 70d connected to a rotation shaft 70c. The rotating shaft 70a is provided so as to be able to expand and contract in the axial direction, as shown by an arrow A7, and has a tip provided in a convex curved shape. On the other hand, the shaft 84a of the cam 84 has a concave curved surface on the end face facing the head adjustment drive unit 70. Similarly, the rotating shaft 70c is also provided so as to be able to expand and contract in the axial direction, as shown by an arrow A8, and has a tip provided in a convex curved shape. The shaft 86a of the cam 86 has a concave end surface on the side facing the head adjustment driving unit 70.
[0041]
When the position of the carriage 1 in the main scanning direction is adjusted and the position of the head adjustment driving unit 70 in the sub-scanning direction is adjusted, a certain head base unit 80 and the head adjustment driving unit 70 on the carriage 1 are moved as shown in FIG. They can be arranged at positions substantially overlapping each other. At this time, the center axis of the axis 84a of the head base unit 80 and the center axis of the rotation axis 70a of the head adjustment drive unit 70 substantially coincide with each other, and the center axis of the axis 86a of the head base unit 80 and the center axis of the rotation axis 70c of the head adjustment drive unit 70 substantially match. Matches.
[0042]
In the state of FIGS. 6 and 7, the rotating shaft 70a extends, and its tip comes into contact with the end of the shaft 84a. Then, when the rotating shaft 70a is rotated by the adjustment motor 70b, the shaft 84a is rotated by the frictional force, and the rotation angle of the cam 84 is set to an appropriate angle. Similarly, the rotating shaft 70c extends and its tip comes into contact with the end of the shaft 86a. When the rotating shaft 70c is rotated by the adjusting motor 70d, the shaft 86a is rotated by the frictional force, and the rotation angle of the cam 86 is set to an appropriate angle.
[0043]
As described above, the rotation angle and the position in the sub-scanning direction of the print head 6 on each head base unit 80 are adjusted. The relative position between each head base unit 80 and the head adjustment drive unit 70 is determined by adjusting the position of the carriage 1 in the main scanning direction by driving the carriage motor 100, The position is adjusted in the scanning direction (the direction in which the printing paper is fed) so that they match. In this embodiment, the head adjustment drive unit 70 is provided so as to move in the sub-scanning direction SS independently of the carriage 1. Therefore, the position of each head base unit 80 and the head adjustment drive unit 70 can be adjusted with a simple mechanism in conjunction with the main scanning by the carriage 1.
[0044]
Further, the tips of the rotating shafts 70a and 70c are provided in a convex curved shape, and the end faces of the shafts 84a and 86a are provided in a concave curved shape. The shafts 84a, 86a do not rotate when pressed against the shaft. In addition, the ends of the rotating shafts 70a and 70c are provided in a convex curved shape, and the end surfaces of the shafts 84a and 86a are provided in a concave curved shape. Even if the central axes are slightly displaced, the rotational force of the rotating shafts 70a, 70c can be transmitted to the shafts 84a, 86a.
[0045]
A3. Configuration of control unit:
FIG. 8 is a block diagram illustrating a configuration of the printer 200 centering on the control circuit 40 as a control unit. This printing system includes a computer 90 as a print control device. Note that the printer 200 and the computer 90 can be called a “printing device” in a broad sense.
[0046]
The control circuit 40 is configured as an arithmetic logic operation circuit including a CPU 41, a programmable ROM (PROM) 43, a RAM 44, and a character generator (CG) 45 storing a dot matrix of characters. The control circuit 40 further includes an I / F dedicated circuit 50 for exclusively interfacing with an external motor or the like, and is connected to the I / F dedicated circuit 50. , A motor drive circuit 62 for driving the paper feed motor, the carriage motor 100, the transport motor 72, the adjustment motors 70b and 70d, a valve drive circuit 65 for driving each valve, and an input unit An input / output unit 240.
[0047]
B. Adjusting the print head:
FIG. 9 is a flowchart illustrating a procedure for adjusting the print head. When adjusting the print head, the CPU 41 first drives the motor 70b to adjust the rotation angles of the 17 print heads 6 on the carriage in step S10. By the adjustment in step S10, the relative position in the sub-scanning direction between the dots formed by the nozzles provided on the same print head is appropriately set. When the print head is inclined, the interval between the nozzles in the print head in the sub-scanning direction is narrowed, so that the interval between dots formed by each nozzle in the sub-scanning direction is also narrowed. However, by performing the adjustment in step S10, it is possible to appropriately adjust the intervals in the sub-scanning direction of the dots formed by the nozzles in the print head.
[0048]
Then, in step S20, the CPU 41 drives the motor 70d to adjust the position of each print head in the sub-scanning direction. By the adjustment in step S20, the relative positions of the dots formed by the nozzles included in the different print heads are appropriately set. Thereafter, in step S30, the ejection timing of the ink droplets from each print head is adjusted to adjust the dot formation position in the main scanning direction.
[0049]
By adjusting the dot formation positions in this order, it is possible to reduce the possibility that the adjustment performed later must be performed again by the adjustment performed earlier. In other words, the dot formation position formed by each nozzle can be efficiently adjusted in the main scanning direction and the sub-scanning direction. Hereinafter, a method of setting the adjustment value in each step will be described.
[0050]
B1. Adjust the angle of each printhead:
FIG. 10 is an explanatory diagram showing an inspection pattern used when adjusting the angle of each print head. When adjusting the angle of each print head, the CPU 41 first prints the test pattern T10 on print paper. One inspection pattern T10 is printed for each print head in one main scan. However, for the sake of simplicity, one print head and its test pattern T10 will be described below. The CPU 41 that prints the inspection pattern T10 corresponds to a “pattern printing unit” in the claims. FIG. 8 shows a “pattern printing unit” as a functional unit of the CPU 41.
[0051]
The inspection sub-pattern T11 which is the left half of the inspection pattern T10 is formed by the upper nozzles of the black nozzle row K. The inspection sub-pattern T12, which is the right half of T10, is formed by the upper nozzles of the yellow nozzle row Y. As shown in FIG. 10A, if the print head 6 is not inclined, the inspection sub-patterns T11 and T12 are formed on a straight line along the main scanning direction MS. However, as shown in FIG. 10B, if the print head 6 is inclined, the inspection sub-patterns T11 and T12 are formed shifted in the sub-scanning direction.
[0052]
After printing the test pattern T10, the CPU 41 reads the test pattern T10 with the optical sensor 1a on the carriage 1. Note that the CPU 41 corresponds to a “pattern reading unit” in the claims. If the entire inspection pattern T10 cannot be read in one sub-scan, the entire inspection pattern T10 may be read in a plurality of sub-scans, or the connection of the inspection sub-patterns T11 and T12 in one sub-scan. Only the part may be read.
[0053]
The CPU 41 calculates the inclination of the print head 6 based on the shift amount d11 between the inspection sub-patterns T11 and T12 in the sub-scanning direction. That is, the CPU 41 also corresponds to a “setting value determining unit” described in the claims. FIG. 8 shows a “pattern reading unit” and a “set value determining unit” as functional units of the CPU 41. Assuming that the interval between the black nozzle row and the yellow nozzle row is Ln, the inclination θ of the print head 6 is obtained by the following equation.
[0054]
θ = arcsin (d11 / Ln) (1)
[0055]
The CPU 41 controls the adjustment motor 70b based on θ obtained by the above equation (1) to adjust the inclination of the print head 6 (see FIGS. 7 and 5). That is, the CPU 41 corresponds to a “head adjustment unit” in the claims. FIG. 8 shows a “head adjustment unit” as a functional unit of the CPU 41.
[0056]
B2. Adjusting the relative position between different print heads:
FIG. 11 is an explanatory diagram showing an inspection pattern used when adjusting the relative position between different print heads. When adjusting the relative position between different print heads, the CPU 41 first prints the inspection pattern T20 on the printing paper. One inspection pattern T20 is printed for each print head in one main scan. However, in the following, for the sake of simplicity, the description will be made by taking the two print heads 6a and 6b and their inspection sub-patterns T20a and T20b. The CPU 41 that prints the test pattern T20 corresponds to a “pattern printing unit” in the claims.
[0057]
Each of the inspection sub-patterns T20a and T20b is formed by the upper nozzles of the black nozzle row K of the print heads 6a and 6b. The design value of the interval in the sub-scanning direction SS between the upper end nozzles of the black nozzle row K of the print heads 6a and 6b is L20. As shown in FIG. 11A, if the print head 6b is not displaced from the print head 6a, the interval between the inspection sub-patterns T20a and T20b becomes equal to L20. However, as shown in FIG. 11B, if the print head 6b is displaced from the print head 6a, the inspection sub-patterns T20a and T20b are formed displaced in the sub-scanning direction. In FIG. 11B, the position of the print head 6b and the inspection pattern T20b when there is no displacement are indicated by broken lines.
[0058]
After printing the inspection sub-patterns T20a and T20b, the CPU 41 reads the inspection sub-patterns T20a and T20b with the optical sensor 1a on the carriage 1. That is, the CPU 41 corresponds to a “pattern reading unit” described in the claims. The CPU 41 measures a distance L21 between the inspection sub-patterns T20a and T20b in the sub-scanning direction, and calculates a displacement d21 of the print head 6b. The displacement d21 of the relative position of the print head 6b with respect to the print head 6a is obtained by the following equation.
[0059]
d21 = L21−L20 (2)
[0060]
The control unit controls the adjustment motor 70d based on d21 obtained by the above equation (2) to adjust the position of the print head 6b in the sub-scanning direction (see FIGS. 7 and 5). That is, the CPU 41 corresponds to a “setting value determining unit” and a “head adjusting unit” in the claims. It is assumed that the relative positions of the 17 print heads are adjusted with respect to the print head that is the most downstream in the sub-scanning direction.
[0061]
B3. Adjustment of ink droplet ejection timing:
FIG. 12 is an explanatory diagram illustrating an example of the inspection pattern T30. When adjusting the dot formation position in the main scanning direction by adjusting the ejection timing of the ink droplet, the inspection pattern T30 is printed. The inspection pattern T30 is composed of a plurality of vertical ruled lines printed by nozzles of two nozzle rows of a nozzle row for adjusting a dot forming position in the main scanning direction and a nozzle row serving as a reference. . Here, a case will be described where the formation position of the dots of the cyan nozzle row C of the print head in the main scanning direction is adjusted based on the black nozzle row K of the print head.
[0062]
Ruled lines T31 formed by the black nozzle rows K are recorded at regular intervals in the main scanning direction MS. On the other hand, the ruled line T32 formed by the cyan nozzle row C is formed by sequentially shifting the position in the main scanning direction in units of 1/1440 inches. As a result, a plurality of pairs of vertical ruled line pairs T33 are printed on the printing paper such that the relative positions of the black vertical ruled line T31 and the cyan vertical ruled line T32 are shifted by 1/1440 inch each. Below the plurality of pairs of vertical ruled lines T33, numbers of the shift adjustment numbers are printed. The shift adjustment number has a function as correction information indicating a preferable correction state. Here, the “preferred correction state” means that the dot recording position (or recording timing) of the nozzle row for adjusting the dot formation position in the main scanning direction is corrected by an appropriate adjustment value and is formed by the reference nozzle row. It means a state in which the position of the dot substantially coincides with the position in the main scanning direction. In the example of FIG. 12, a vertical ruled line pair having a deviation adjustment number of 4 indicates a preferable correction state. The user observes the inspection pattern T30 and inputs the shift adjustment number 4 from the input / output unit 240.
[0063]
When performing image printing, the CPU 41 adjusts the ejection timing of the ink droplets from the cyan nozzle row based on the adjustment value when the shift adjustment number is 4 in the inspection pattern T30 in FIG. As a result, the cyan dots formed by the cyan nozzle row are formed at appropriate positions with respect to the black dots formed by the reference black nozzle row. In this way, the positions where dots are formed in the main scanning direction by the nozzle rows are adjusted. In the present embodiment, it is assumed that the dot formation position of each nozzle row of the 17 print heads is adjusted based on the black nozzle row of the print head that is the most downstream in the sub-scanning direction.
[0064]
By performing the three adjustments as described above (FIG. 9), the positions of the dots formed on the printing paper can be changed in the main scanning direction (the moving direction of the carriage 1) and the sub-scanning direction (the feeding direction of the printing paper). Can be adjusted appropriately.
[0065]
C. Second embodiment:
FIG. 13 is an explanatory diagram illustrating the head adjustment drive unit 70p, the head base unit 80p, and the print head 6 according to the second embodiment. In the head base unit 80p of the second embodiment, as shown by an arrow A10, a print head can be attached to a different position in a direction perpendicular to the print paper located at a position facing the print head 6. That is, the distance between the surface of the print head 6 where the nozzles are provided and the printing paper can be adjusted. Other points are the same as those of the printing apparatus of the first embodiment.
[0066]
The head base unit 80p has four corners fixed to the carriage 1 with screws 81c instead of the screws 81a (see FIGS. 5 and 7) of the first embodiment. The four screws 81c fix the head base unit 80p to the carriage 1 with a gap therebetween. The four screws 81c are provided so that the axis is in a direction perpendicular to the print paper facing the print head. When the screw 81c is rotated, the distance between the carriage 1 and the head base unit 80p changes as shown by an arrow A10. The screw 81c has a concave curved end surface on the side facing the head adjustment drive unit 70p.
[0067]
Further, in addition to the configuration of the first embodiment, the head adjustment driving unit 70p of the second embodiment further includes an adjustment motor 70f connected to a rotation shaft 70e, an adjustment motor 70h connected to a rotation shaft 70g, An adjustment motor 70j connected to the shaft 70i and an adjustment motor 701 connected to the rotating shaft 70k are provided. Each of the rotating shafts 70e, 70g, 70i, and 70k is provided so as to be able to expand and contract in the axial direction, and has a tip provided in a convex curved shape. Note that, since FIG. 13 is a side view, the rotating shaft 70i, the adjusting motor 70j, the rotating shaft 70k, and the adjusting motor 701 at positions overlapping with other adjusting motors and rotating shafts are not shown.
[0068]
When the position of the carriage 1 in the main scanning direction is adjusted and the position of the head adjustment driving unit 70 in the sub-scanning direction is adjusted, a certain head base unit 80 and the head adjustment driving unit 70 on the carriage 1 are arranged at positions substantially overlapping each other. (See FIG. 6). At this time, the four screws 81c of the head base unit 80p and the central axes of the rotation shafts 70e, 70g, 70i, and 70k of the head adjustment drive unit 70p substantially coincide with each other.
[0069]
In such a state, each of the rotating shafts 70e, 70g, 70i, and 70k is extended, and its tip comes into contact with the end of each screw 81c. When the rotation shafts 70e, 70g, 70i, and 70k are rotated by the respective adjustment motors, the screws 81c are rotated by the frictional force, and the distance between the head base unit 80p and the carriage 1 is adjusted. As a result, the distance between the surface of the print head 6 where the nozzles are provided and the printing paper is adjusted.
[0070]
With such an embodiment, it is possible to adjust the interval between the surface of the print head 6 where the nozzles are provided and the printing paper. Note that the screw 81c corresponds to a “third adjusting unit” in the claims.
[0071]
In the second embodiment, the four screws 81c, the shaft 84a, and the shaft 86a are provided so as to rotate about directions parallel to each other. Therefore, the head adjustment drive unit 70 can easily operate these adjustment members. In addition, since the axial directions of the four screws 81c, the shaft 84a, and the shaft 86a are perpendicular to the moving direction (main scanning direction) of the carriage 1 and the moving direction of the head adjustment driving unit 70, the carriage 1 and the head adjustment drive are controlled. The rotating shafts 70a, 70c, 70e, 70g, 70i, 70k can be connected to the four screws 81c, the shaft 84a, and the shaft 86a from a direction that does not interfere with the structure of the portion 70. It should be noted that the direction of the axis is “perpendicular” to the moving direction of the carriage 1 and the moving direction of the head adjustment driving unit 70 when the direction of the shaft is And 90 degrees plus or minus 10 degrees with respect to the plane defined by
[0072]
D. Third embodiment:
FIG. 14 is an explanatory diagram showing another inspection pattern used when adjusting the angle of each print head. When the angle of each print head is adjusted (see step S10 in FIG. 9), a pattern such as the inspection patterns T40a and T40b may be printed on the printing paper to determine the adjustment amount. The inspection patterns T40a and T40b are printed one for each print head in one main scan. However, in the following, for the sake of simplicity, two print heads 6a and 6b and their test patterns T40a and T40b will be described.
[0073]
The inspection patterns T40a and T40b are formed by simultaneously ejecting ink droplets from a plurality of nozzles of the black nozzle row K of the print heads 6a and 6b. Since each nozzle row should be arranged along the sub-scanning direction as shown in FIG. 3, if the print heads 6a and 6b are mounted on the carriage 1 at an appropriate angle, the inspection pattern T40a , T40b should be parallel to each other, and their directions should be parallel to the sub-scanning direction. However, as shown in FIG. 14, when the print head 6b is inclined with respect to the print head 6a, the inspection patterns T40a and T40b form a predetermined angle θ.
[0074]
After printing the test patterns T40a and T40b, the CPU 41 reads the test patterns T40a and T40b with the optical sensor 1a on the carriage 1. Thereafter, the CPU 41 calculates an angle θ formed by the inspection patterns T40a and T40b.
[0075]
The CPU 41 controls the adjustment motor 70b based on the above θ to adjust the inclination of the print head 6 (see FIGS. 7 and 5). It is assumed that the relative positions of the 17 print heads are adjusted in rotation angle with respect to the black nozzle row of the print head located most downstream in the sub-scanning direction. Even in such an embodiment, the rotation angle of each print head can be adjusted.
[0076]
E. FIG. Modification:
The present invention is not limited to the above embodiment, but can be implemented in various forms without departing from the gist of the invention. For example, the following modifications are possible.
[0077]
E1. Modification 1
In the above embodiment, the inclination of the print head is adjusted using a cam and a spring, and the position of the print head in the sub-scanning direction is adjusted (see FIG. 5). However, other means such as a screw and a worm gear can be used to adjust the tilt of the print head and the position in the sub-scanning direction. Further, in the above embodiment, the interval between the print head and the printing paper was adjusted using a screw (see FIG. 13). However, other means such as a worm gear and a cam can be used to adjust the distance between the print head and the printing paper.
[0078]
Further, the head adjustment drive unit 70 does not necessarily have to directly operate a member that changes the inclination or the position of the print head as in the above embodiments (see FIGS. 5 and 13). That is, another member for transmitting the operation may be provided between the member that changes the inclination and the position of the print head and the member that the head adjustment driving unit 70 scans. However, the member operated by the head adjustment drive unit 70 is preferably a member operated by being rotated about a direction from the member toward the head adjustment drive unit 70 as an axis. With such an embodiment, the head adjustment drive unit 70 can easily operate the members.
[0079]
Further, in the above embodiment, the slide base unit 83 is provided so that the print head 6 can be fixed at a different position in the feeding direction of the printing paper (see FIG. 5). However, the slide base unit 83 may be configured so that it can be fixed at a different position in a direction different from the direction of feeding the printing paper. That is, the printing apparatus only needs to include an adjusting unit that can fix the print head on the carriage at a different position in a direction intersecting with the main scanning direction. For example, if the print head is provided so as to be slidable in a direction intersecting with the sub-scanning direction, there are the following advantages. That is, as compared with a mode in which the print head is provided so as to be slidable in the sub-scanning direction, it is possible to finely adjust the position in the sub-scanning direction by moving the print head largely.
[0080]
In the above-described embodiment, the rotation base unit 82 is provided so that the print head 6 can be fixed at different rotation angles about a direction perpendicular to the printing paper positioned at a position facing the print head 6. (See FIG. 5). However, the rotation base unit 82 may be configured so that the rotation base unit 82 can be fixed at a different rotation angle around an axis different from the direction perpendicular to the printing paper. That is, the printing apparatus only needs to include an adjustment unit that can fix the print head on the carriage at a different rotation angle with respect to a direction intersecting a plane formed by a portion of the print medium facing the print head as an axis. The “plane formed by a portion of the print medium facing the print head” is a portion of the print medium conveyed by a conveyance unit such as a roll, which is located at a position facing the print head and in which dots are formed. Is the plane of the print medium. If a planar platen is provided, this plane is equal to the plane of the platen. Note that the angle at which the plane formed by the print medium and the rotation axis intersect may be an angle other than perpendicular.
[0081]
E2. Modified example 2:
In the above-described embodiment, the relative position of each print head is adjusted based on the print head that is the most downstream in the sub-scanning direction. However, the reference print head can be any print head. Further, the dot formation position of each nozzle row has been adjusted with reference to the black nozzle row of the print head that is the most downstream in the sub-scanning direction. However, the reference nozzle row can be any nozzle row. However, it is preferable that the nozzle row be an ink color that is easily visible.
[0082]
E3. Modification 3:
In the above embodiment, the carriage 1 was provided with a mechanism capable of adjusting the rotation angles and the positions in the sub-scanning direction of all the print heads. However, the carriage 1 may have a print head without such an adjustment mechanism. That is, at least a part of the print heads may be provided with a mechanism capable of adjusting the rotation angle and the position in the sub-scanning direction.
[0083]
E4. Modification 4:
In the above embodiment, the head adjustment driving unit 70 moves independently of the carriage 1 (see FIG. 2). However, the slide shaft 71 may be provided on the carriage 1 so that the head adjustment driving unit 70 is provided so as to move integrally with the carriage 1. That is, the head adjustment drive unit 70 can be provided so as to be movable with respect to each print head on the carriage 1. However, it is preferable that the number of head adjustment drive units 70 be smaller than the number of print heads. By doing so, the weight of the printing apparatus can be reduced, and the manufacturing cost of the printing apparatus can be reduced.
[0084]
In a mode in which the head adjustment drive unit 70 is provided so as to move integrally with the carriage 1, when the print head 6 is two-dimensionally arranged on the carriage, the head adjustment drive unit 70 is also mounted on the carriage. It is preferable to provide it so that it can be moved three-dimensionally. For example, it is preferable to provide a slide mechanism (slide shaft or slide guide) on the carriage 1 that can move in the main scanning direction and the sub-scanning direction.
[0085]
E5. Modification 5:
The present invention is also applicable to a drum scan printer. INDUSTRIAL APPLICABILITY The present invention can be applied not only to a so-called inkjet printer but also to a printing apparatus that prints an image by discharging ink from a print head. Such printing apparatuses include, for example, a facsimile apparatus and a copying apparatus.
[0086]
E6. Modification 6:
In the above embodiment, a part of the configuration realized by hardware may be replaced by software, and conversely, a part of the configuration realized by software may be replaced by hardware. For example, a part of the functions of the control circuit 40 (see FIG. 8) in the printer 200 may be executed by the computer 90.
[Brief description of the drawings]
FIG. 1 is a perspective view schematically showing the configuration of a printer as one embodiment of the present invention.
FIG. 2 is an explanatory diagram illustrating a configuration of a printing unit.
FIG. 3 is an explanatory diagram showing an arrangement of nozzles on a lower surface of one print head.
FIG. 4 is an explanatory diagram showing a schematic configuration of a carriage.
FIG. 5 is a plan view showing a head base unit.
FIG. 6 is an explanatory view of the carriage as viewed from the rear side.
FIG. 7 is an explanatory diagram showing a head adjustment drive unit, a head base unit, and a print head.
FIG. 8 is a block diagram showing a configuration of a printer centering on a control circuit as a control unit.
FIG. 9 is a flowchart illustrating a procedure for adjusting a print head.
FIG. 10 is an explanatory diagram showing an inspection pattern used when adjusting the angle of each print head.
FIG. 11 is an explanatory diagram showing an inspection pattern used when adjusting a relative position between different print heads.
FIG. 12 is an explanatory diagram showing an example of an inspection pattern.
FIG. 13 is an explanatory diagram illustrating a head adjustment drive unit, a head base unit, and a print head according to a second embodiment.
FIG. 14 is an explanatory diagram showing another inspection pattern used when adjusting the angle of each print head.
[Explanation of symbols]
1 ... carriage
1a: Optical sensor
2 ... Nozzle plate
2a ... Nozzle plate
3… Sub tank
3S… Sub tank set
3a to 3f: Sub tank
6, 6a, 6b ... print head
9, 9a to 9f ... Main tank
10A: First inspection unit
10B: Second inspection unit
20 ... Cap part
30 ... Wiper part
40 ... Control circuit
41 ... CPU
44 ... RAM
50 ... I / F dedicated circuit
61 ... Head drive circuit
62 ... Motor drive circuit
64 Pump drive circuit
65 ... Valve drive circuit
70, 70p: Head adjustment drive unit
70a, 70c, 70e, 70g, 70i, 70k ... Rotary axis
70b, 70d, 70f, 70h, 70j, 70l ... Adjustment motor
71 ... Slide axis
72 ... Transport motor
73 ... Pulley
74 ... drive belt
80,80p ... Head base unit
81: Fixed base unit
81a, 81c ... screws
81b ... convex part
82 ... Rotating base unit
82a ... axis
82b, 82c: slide pins
82d ... convex part
83 ... Slide base unit
83a ... Through-hole
83b ... Slide groove
84 ... Cam
84a ... shaft
85 ... Spring
86 ... Cam
86a ... shaft
87 ... Spring
90 ... Computer
100 ... carriage motor
101 ... drive belt
102: Main scanning guide member
103: ink supply path
200 ... Printer
210 ... paper feeding unit
211 ... Roll paper holder
212 ... spindle
215 ... Support column
220 printing section
230: paper discharge unit
231 Holder
232 ... Spindle
235 ... Support column
240 input / output unit
A2: Arrow indicating movement of the rotation base unit 82
A3: Arrow indicating movement of slide base unit 83
Ap: arrow indicating the range in the sub-scanning direction where nozzles are provided
C: Cyan nozzle row
K: Black nozzle row
Ln: Interval between black nozzle row and yellow nozzle row
L20: Design value of the interval between the nozzles at the upper end of the black nozzle row
L21: interval between inspection sub-patterns T20a and T20b
LC: Light cyan nozzle row
LK: Light black nozzle row
LM: Light magenta nozzle row
M: Magenta nozzle row
MS: Main scanning direction
P… Printing paper
SS: Sub-scanning direction
T10: Inspection pattern for adjusting the rotation angle of the print head
T11, T12 ... inspection sub-pattern
T20, T20a, 20b: Inspection pattern for adjusting the displacement of the print head in the sub-scanning direction
T30: Inspection pattern for adjusting the ink droplet ejection timing
T31: Vertical ruled line formed by the reference nozzle row
T32: Vertical ruled line formed by the nozzle row to be adjusted
T33: Vertical ruled line pair
T40, T40a, 40b: Inspection pattern for adjusting the rotation angle of the print head
Y: Yellow nozzle row
d11: deviation amount of the inspection sub-pattern in the sub-scanning direction
d21: shift amount of the inspection sub-pattern in the sub-scanning direction
θ: Deviation angle of inspection sub-pattern

Claims (8)

A printing device that prints an image by forming dots on a print medium,
A dot recording head provided with a plurality of dot forming elements for forming dots on the print medium,
A carriage provided with the dot recording head;
A main scanning drive unit that performs main scanning by moving at least one of the carriage and the print medium;
A control unit for controlling the dot recording head and a main scanning drive unit,
The carriage,
A first adjustment unit that can fix the print head on the carriage at a different position in a direction intersecting with the main scanning direction;
A printing apparatus comprising: a second adjustment unit configured to fix the print head on the carriage at a different rotation angle around a direction intersecting with a plane formed by a portion of the print medium facing the print head as an axis. The printing device according to claim 1,
The printing apparatus further comprising a third adjustment unit that can fix the print head on the carriage by changing a distance between a portion of the print medium facing the print head and the print head. The printing device according to claim 1,
The carriage has a plurality of the print heads,
The first and second adjustment units are provided at least one each for one print head,
The printing apparatus further includes an adjustment drive unit that is provided so as to be relatively movable with respect to the plurality of print heads, and that can drive the first and second adjustment units.
A printing device, wherein the number of the adjustment drive units is smaller than the number of the print heads. The printing device according to claim 3,
The printing apparatus, wherein the adjustment drive unit can move in a direction intersecting with the main scanning direction independently of the carriage. The printing device according to claim 3,
The first adjusting unit includes a first shaft unit that can rotate to change a position of the print head in a direction intersecting with the main scanning direction,
The second adjustment unit includes a second shaft unit that can change the rotation angle of the print head by being rotated,
The printing apparatus, wherein the directions of the rotation axes of the first and second shaft portions are both perpendicular to the main scanning direction and the moving direction of the adjustment driving unit. The printing device according to claim 3, further comprising:
With a sensor that can read the image recorded on the print medium,
The plurality of dot forming elements include two or more dot forming elements provided at different positions in a direction intersecting with the main scanning direction,
The control unit includes:
While performing the main scanning, dots are formed on the printing medium by the two or more dot forming elements, respectively, at different positions in a direction intersecting with the main scanning direction, and two or more extending in the main scanning direction. A pattern printing unit for printing the inspection pattern of
A pattern reading unit that reads the two or more inspection patterns with the sensor;
Based on the data of the two or more inspection patterns read by the sensor, at least one of a set value of a position in a direction intersecting with the main scanning direction of the print head and a set value of the rotation angle. A setting value determining unit to determine,
A printing apparatus comprising: a head adjustment unit that drives the adjustment unit to the adjustment drive unit according to the set value. The printing device according to claim 3, further comprising:
With a sensor that can read the image recorded on the print medium,
The plurality of dot forming elements include two or more dot forming element rows provided along a direction intersecting with the main scanning direction,
The control unit includes:
A pattern printing unit that forms dots on the print medium at the same timing using the dot forming elements included in each of the dot forming element rows, and prints an inspection pattern for each of the dot forming element rows,
A pattern reading unit that reads the inspection pattern with the sensor,
A setting for determining at least one of a set value of a position in a direction intersecting with the main scanning direction of the print head and a set value of the rotation angle based on the data of the inspection pattern read by the sensor. A value determining unit;
A printing apparatus comprising: a head adjustment unit that drives the adjustment unit to the adjustment drive unit according to the set value. A method of adjusting a printing apparatus for printing an image by forming dots on a print medium,
(A) a carriage including a dot recording head having a plurality of dot forming elements for forming dots on the print medium, wherein at least one of the carriage and the print medium is moved to perform main scanning and perform dot scanning. Preparing a printing device that forms
(B) adjusting a mounting angle of the print head on the carriage, the mounting angle being set to an axis intersecting a plane intersecting a plane formed by a portion of the print medium facing the print head;
(C) adjusting a mounting position of the print head on the carriage in a direction intersecting with the main scanning direction;
(D) adjusting the dot formation timing by each of the dot formation elements.

Images