JP2008132795A - Printing apparatus capable of adjusting attaching position of print head to carriage - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To eliminate positional misalignment in the subscanning direction of dots formed by a plurality of dot formation elements. <P>SOLUTION: A carriage 1 of a printing apparatus has first adjustment parts 83, 86, and 87 for fixing the print head on the carriage at the positions different in the direction intersecting a main scanning direction; and second adjustment parts 82, 84, and 85 for fixing the print head on the carriage at different rotation angles wherein the direction intersecting the plane constituting the part opposed to the print head in a print medium is used as an axis. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a printing apparatus for forming an image by forming dots on a printing paper with a plurality of dot forming elements, and more particularly to a technique for eliminating a positional deviation in the sub-scanning direction of dots formed by each dot forming element.

In recent years, inkjet printers have been widely used as image printing apparatuses.
In an ink jet printer, a print head having a large number of nozzles is fixed on a carriage. Then, while the carriage is reciprocated at a position facing the printing paper and main scanning is performed, ink droplets are ejected from the nozzles to form dots on the printing paper. When dot formation is completed in the main scanning direction at a certain position on the printing paper, the printing paper is sent to form dots at another position. In such a printing apparatus, when the dot formation position is deviated from the assumed position at the time of design, the deviation can be eliminated by shifting the dot formation timing in the main scanning direction (for example, Patent Document 1).

JP 2000-296648 A

  However, the dot formation position deviation in the printing paper feed direction (sub-scanning direction) cannot be resolved by shifting the dot formation timing. Conventionally, a device for eliminating such a shift in the dot formation position in the sub-scanning direction has not been made sufficiently.

  The present invention has been made to solve the above-described problems in the prior art, and in a printing apparatus for forming an image by forming dots on a printing paper with a plurality of dot forming elements, the dot in the sub-scanning direction is formed. The purpose is to eliminate misalignment.

  In order to solve at least a part of the above problems, in the present invention, a predetermined process is performed for 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 unit that performs main scanning, and a control unit that controls the dot recording head and the main scanning drive unit.

  The carriage of the printing apparatus includes a first adjustment unit that can fix the print head on the carriage at different positions in the direction intersecting the main scanning direction, and the print head on the carriage. And a second adjustment unit that can be fixed at different rotation angles with a direction intersecting a plane formed by the facing portions as an axis. With such an aspect, it is possible to adjust the dot formation position shift in a direction different from the main scanning direction.

  The carriage preferably 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. With such an aspect, the interval between the print head and the print medium can be adjusted.

  In the case where the carriage has a plurality of print heads and at least one first and second adjustment unit is provided for each print head, the printing apparatus is as follows. It is preferable to use such a mode. That is, it is preferable that the printing apparatus includes an adjustment driving 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. The number of adjustment driving units is preferably smaller than the number of print heads. In such an aspect, since the adjustment driving unit can move relative to the plurality of print heads, a relatively large number of print heads can be adjusted with a relatively small number of adjustment driving units.

  Note that the adjustment driving unit is preferably capable of moving in a direction crossing the main scanning direction independently of the carriage. With such an aspect, the adjustment drive unit can be two-dimensionally moved relative to the carriage with a simple mechanism.

  In addition, the first adjustment unit preferably includes a first shaft unit that can be rotated to change the position of the print head in a direction intersecting with the main scanning direction. Is preferably provided with a second shaft portion that can be rotated to change the rotation angle of the print head. The directions of the rotation axes of the first and second shaft parts are preferably perpendicular to the main scanning direction and the moving direction of the adjustment drive unit. With such an aspect, the adjustment drive unit can easily drive each adjustment unit without interfering with the carriage and the print head.

  Further, when the plurality of dot forming elements include two or more dot forming elements provided at different positions in the direction intersecting with the main scanning direction, the following aspect is preferable. 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, each of the two or more dot forming elements forms dots on the print medium, and is in a different position in the direction intersecting with the main scanning direction. Two or more test patterns that extend in the direction of are printed.

  Thereafter, two or more inspection patterns are read by the sensor. Then, based on data of two or more inspection patterns read by the sensor, at least one of a position setting value and a rotation angle setting value in a direction intersecting with the main scanning direction of the print head is determined. In accordance with the set value, the adjustment drive unit drives the adjustment unit. With this aspect, the print head can be adjusted according to the actual printing result.

  Further, when the plurality of dot forming elements include two or more dot forming element rows respectively provided along the direction intersecting with the main scanning direction, the following aspect may 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 array, and the inspection pattern is printed for each dot forming element array. Then, the inspection pattern is read by the sensor. Thereafter, based on the inspection pattern data read by the sensor, at least one of a position setting value and a rotation angle setting value in a direction crossing the main scanning direction of the print head is determined. Even in such an aspect, the print head can be adjusted according to the actual printing result.

  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, which is the axis that intersects with the plane formed by the portion of the print medium facing the print head, is adjusted. Then, the mounting position of the print head on the carriage, which is in the direction intersecting with the main scanning direction, is adjusted. Thereafter, the dot formation timing by each dot formation element is adjusted. With such an aspect, it is possible to efficiently eliminate the interval in the sub-scanning direction, the position, and the positional deviation in the main scanning direction of the dots formed by each dot forming element.

  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 that records a computer program, a data signal that includes the computer program and is embodied in a carrier wave, and the like.

Next, embodiments of the present invention will be described in the following order based on examples.
A. Device configuration:
A1. Overall printer configuration:
A2. Configuration of head base unit and head adjustment drive:
A3. Configuration of control unit:
B. Print head adjustment:
B1. Refilling ink during printing:
B2. Ink replenishment between image prints:
C. Second embodiment:
D. Third embodiment:
E. Variation:
E1. Modification 1:
E2. Modification 2:
E3. Modification 3:
E4. Modification 4:
E5. Modification 5:
E6. Modification 6:

A. Device configuration:
A1. Overall printer configuration:
FIG. 1 is a perspective view schematically showing a configuration of a printer 200 as an embodiment of the present invention. The printer 200 is a printer corresponding to a relatively large printing paper P such as JIS standard A row 0 paper, B row 0 paper, or roll paper. The printing paper P is supplied from the paper feeding unit 210 to the printing unit 220. The printing unit 220 performs printing by ejecting 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.

  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 that holds the roll paper, and a first spindle receiver 213 and a second spindle receiver 214 on which the spindle 212 can be attached / detached and suspended. The two spindle receivers 213 and 214 are respectively provided on two support pillars 215 provided on the upper part of the printer 200. Both ends of the spindle 212 are mounted on the first spindle receiver 213 and the second spindle receiver 214 after the roll paper is mounted in the center.

  The paper discharge unit 230 includes a take-up holder 231 capable of taking up roll paper. The take-up holder 231 includes a spindle 232 that takes up the roll paper printed by the printing unit 220, and a first spindle receiver 233 and a second spindle receiver 234 that allow the spindle 232 to be attached and detached and suspended. The two spindle receivers 233 and 234 are respectively provided on two support columns 235 provided at the lower part of the printer 200. Both ends of the spindle 232 are mounted on the first spindle receiver 233 and the second spindle receiver 234, and can be rotated by a driving means (not shown). The spindle 212 may be rotated by driving means to wind up the printing paper P. Further, as will be described later, a paper feeding unit such as a paper discharge roller may be provided in the printing unit 220, and the printing paper P may be discharged by driving the paper feeding unit.

  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.

  FIG. 2 is an explanatory diagram illustrating the configuration of the printing unit 220. The printing unit 220 includes a carriage 1 on which a plurality of print heads (described later) are installed. A plurality of sub-tank sets 3S for temporarily storing ink used by the print head are mounted on the carriage 1. The carriage 1 is connected to a drive belt 101 driven by a carriage motor 100, and can be moved along the main scanning direction MS by being guided by a main scanning guide member 102. 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.

A first inspection unit 10A and a second inspection unit 10B that perform nozzle discharge inspection are provided at both ends of the printing paper P in the movement range of the carriage 1 in the main scanning direction.
Next to the second inspection unit 10B, there are provided a wiper unit 30 for wiping the nozzles, a cap unit 20 for sealing the nozzle group for cleaning, and a main tank 9 for supplying ink to the sub tank set 3S. It has been.

  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 installed 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 installed in the conveyance direction of the printing paper P. Is provided. 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 between the conveyance motor 72 and the pulley 73 in parallel with the slide shaft 71, 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 along the transport direction of the printing paper P on the slide shaft 71. The detailed configuration of the head adjustment driving unit 70 will be described later.

  When performing printing, the carriage 1 performs printing by ejecting 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.

  The sub tank set 3 </ b> S and the main tank 9 are connected by an ink supply path 103. In this embodiment, there are six types of ink sub-tanks 3a to 3f of black K, cyan C, light cyan LC, magenta M, light magenta LM, and yellow Y, which are connected to the corresponding six main tanks 9a to 9f, respectively. Has been. In the following description, when it is not necessary to distinguish the ink colors when the configuration and function of the printer are described using the sub tanks 3a to 3f and the main tanks 9a to 9f, the sub tank is described as the sub tank 3. The main tank will be described as the main tank 9.

  The usable ink is not limited to six types, but four types of ink (for example, black K, cyan C, magenta M, yellow Y) and seven types of ink (for example, black K, light black LK, cyan C). , Light cyan LC, magenta M, light magenta LM, yellow Y) can also be used. The type of ink that can be used can be determined according to the user's request.

  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 and 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 ink is assigned to each nozzle group, but the same ink may be ejected from a plurality of nozzle groups.

  FIG. 4 is an explanatory diagram showing 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 (see FIG. 3) of black K, cyan C, light cyan LC, magenta M, light magenta LM, and yellow Y provided on the 17 print heads 6 are within the range indicated by the arrow Ap. Are arranged at equal intervals in the sub-scanning direction SS. Therefore, this printer can perform printing of a relatively large area at a time, and can perform printing at high speed even when using a relatively large printing paper.

A2. Configuration of the head base unit and the 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 attached to the carriage 1 with one print head 6 attached thereto. That is, the 17 print heads 6 provided on the carriage 1 are attached to the carriage 1 via the head base unit 80, respectively. The head base unit 80 includes a fixed base unit 81, a rotation base unit 82, and a slide base unit 83.

The fixed base unit 81 is fixed to the carriage 1 at the four corners by screws 81 a and attached to the carriage 1. On the fixed base unit 81, a rotation base unit 82 is attached 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. As shown by the arrow A2, the rotation base unit 82 can be rotated by 5 degrees left and right around the shaft 82a.

  A cam 84 is provided on the fixed base unit 81. The cam 84 is rotatable around 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 a broken line and arrows A4 and A2 in FIG. 5, the rotation base unit 82 has a rotation angle about the shaft 82a according to the rotation angle of the cam 84. change. The shaft 84a corresponds to a “second shaft portion” in the claims.

  Further, a convex portion 81b is provided on the fixed base unit 81, and a spring 85 is attached to the convex portion 81b. The spring 85 is in contact with the rotation base unit 82 on the side surface opposite to the side surface with which 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. For this reason, the cam 84 is pushed by the spring 85 via the rotary 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 adjusting portion” in the claims.

  On the rotation base unit 82, slide pins 82b and 82c are provided. The slide pins 82 b and 82 c are arranged in a direction substantially perpendicular to the conveyance direction of the carriage 1 with the fixed base unit 81 attached to the carriage 1.

  The slide base unit 83 has slide grooves 83b and 83c. The slide grooves 83b and 83c are rectangular holes, and penetrate the slide pins 82b and 82c, respectively, in a state where the slide base unit 83 is attached to the rotary base unit 82. The slide base unit 83 is slidably mounted on the rotary base unit 82 by the slide grooves 83b and 83c and the slide pins 82b and 82c. The slide direction of the slide base unit 83 is substantially perpendicular to the carriage 1 conveyance direction in a state where the fixed base unit 81 is attached to the carriage 1.

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 in which the slide grooves 83b and 83c are arranged.
The cam 86 is rotatable around a shaft 86a provided in parallel with the shaft 82a. The shaft 86a corresponds to a “first shaft portion” in the claims. One end of the cam 84 is in contact with the slide base unit 83, and the slide base unit 83 is moved on the rotation base unit 82 in accordance with the rotation angle of the cam 86, as shown by a one-dot chain line and arrows A 6 and A 3 in FIG. Slide.

  Further, a convex portion 82d is provided on the fixed base unit 81, and a spring 87 is attached to the convex portion 82d. The spring 87 is in contact with the slide base unit 83 on the side surface opposite to the side surface with which the cam 86 is in contact, and presses the slide base unit 83 against the cam 86. Note that 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 adjusting portion” in the claims.

  The slide base unit 83 is provided with a through hole 83a. The print head 6 is attached to the through hole 83 a 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 rotation 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 rotation base unit 82. As a result, in a state in which the print head is attached to the through hole 83a, the surface of the print head 6 on which the nozzle row is provided directly faces the printing paper through these through holes.

  With the configuration described above, 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.

  FIG. 6 is an explanatory view of the carriage 1 as seen from the back side. FIG. 6 also shows a head adjustment drive unit 70 and a 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. An optical sensor 1 a is provided on the carriage 1. The optical sensor 1a can read an image printed on printing paper.

  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 to which the rotation shaft 70a is connected and an adjustment motor 70d to which the rotation shaft 70c is connected. As shown by an arrow A7, the rotation shaft 70a is provided so as to be extendable and contractible in the axial direction, and the tip is provided in a convex curved shape. On the other hand, the shaft 84a of the cam 84 is provided with a concave curved end surface on the side facing the head adjustment driving unit 70. Similarly, the rotation shaft 70c is also provided so as to be extendable and contractible in the axial direction as indicated by an arrow A8, and the tip thereof is provided in a convex curved surface shape. The shaft 86a of the cam 86 has a concave curved end surface on the side facing the head adjustment driving unit 70.

  When the position of the carriage 1 in the main scanning direction is adjusted and the position of the head adjustment drive unit 70 in the sub-scanning direction is adjusted, as shown in FIG. 6, a certain head base unit 80 and the head adjustment drive unit 70 on the carriage 1 are moved. It can arrange | position in the position which mutually overlaps. At this time, the axis 84a of the head base unit 80 and the central axis of the rotation shaft 70a of the head adjustment drive unit 70 substantially coincide with each other, and the axis 86a of the head base unit 80 and the central axis of the rotation shaft 70c of the head adjustment drive unit 70 are substantially the same. Match.

  6 and 7, the rotary shaft 70a extends and the tip thereof contacts the end of the shaft 84a. Then, when the rotation 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. Then, when the rotation shaft 70c is rotated by the adjustment 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.

  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 driving unit 70 is adjusted by driving the carriage motor 100 to adjust the position of the carriage 1 in the main scanning direction, and driving the conveyance motor 72 to adjust the position of the head adjustment driving unit 70. The position is matched by adjusting the position in the scanning direction (printing paper feeding direction). In the present embodiment, the head adjustment driving unit 70 is provided so as to move independently of the carriage 1 in the sub-scanning direction SS. Therefore, the head base unit 80 and the head adjustment drive unit 70 can be aligned with a simple mechanism in conjunction with the main scanning by the carriage 1.

  Further, the distal ends of the rotation shafts 70a and 70c are provided in a convex curved surface shape, and the end surfaces of the shafts 84a and 86a are provided in a concave curved surface shape, so that the distal ends of the rotation shafts 70a and 70c are the end surfaces of the shafts 84a and 86a. The shafts 84a and 86a are not rotated even when pressed against the shaft. Further, the tips 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, so that the central axes of the rotating shafts 70a and 70c and the shafts 84a and 86a Even if the central axis is slightly deviated, the rotational force of the rotary shafts 70a and 70c can be transmitted to the shafts 84a and 86a.

A3. Configuration of control unit:
FIG. 8 is a block diagram showing the 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 apparatus. The printer 200 and the computer 90 can be called “printing apparatuses” in a broad sense.

  The control circuit 40 is configured as an arithmetic and logic circuit including a CPU 41, a programmable ROM (PROM) 43, a RAM 44, and a character generator (CG) 45 that stores a dot matrix of characters. The control circuit 40 is further connected to an I / F dedicated circuit 50 dedicated to interface with an external motor and the like, and is connected to the I / F dedicated circuit 50, and drives the print head 6 to drive ink from the nozzle plate 2. A head driving circuit 61 for discharging the paper, a paper driving motor, a carriage motor 100, a conveying motor 72, a motor driving circuit 62 for driving the adjusting motors 70b and 70d, a valve driving circuit 65 for driving each valve, and an input unit Input / output unit 240.

B. Print head adjustment:
FIG. 9 is a flowchart showing the procedure for adjusting the print head. When adjusting the print heads, the CPU 41 first adjusts the rotation angles of the 17 print heads 6 on the carriage by driving the motor 70b in step S10.
By adjusting in step S10, the relative position in the sub-scanning direction of the dots formed by the nozzles provided in the same print head is appropriately set. When the print head is tilted, the interval in the sub-scanning direction of each nozzle in the print head is narrowed, so the interval in the sub-scanning direction of the dots formed by each nozzle is also narrowed. However, by performing the adjustment in step S10, it is possible to appropriately adjust the interval in the sub-scanning direction of the dots formed by each nozzle in the print head.

  In step S20, the CPU 41 drives the motor 70d to adjust the position of the print heads in the sub-scanning direction. By adjusting in step S20, the relative positions of dots formed by nozzles included in different print heads are appropriately set. Thereafter, in step S30, the ink droplet ejection timing from each print head is adjusted to adjust the dot formation position in the main scanning direction.

  By adjusting the dot formation position in this order, it is possible to reduce the possibility of having to redo the adjustments made earlier by the adjustments made later. That is, the dot formation position formed by each nozzle can be adjusted efficiently in the main scanning direction and the sub-scanning direction. Below, the adjustment value setting method in each step will be described.

B1. Adjust the angle of each print head:
FIG. 10 is an explanatory diagram showing inspection patterns 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 the printing paper. One inspection pattern T10 is printed for each print head in one main scan. However, in order to simplify the description, one print head and its inspection pattern T10 will be described below. The CPU 41 that prints the test pattern T10 corresponds to a “pattern printing unit” in the claims. A “pattern printing unit” as a functional unit of the CPU 41 is shown in FIG.

  The inspection sub-pattern T11 which is the left half portion of the inspection pattern T10 is formed by the nozzles at the upper end of the black nozzle row K. The inspection sub-pattern T12, which is the right half of T10, is formed by the nozzles at the upper end of the yellow nozzle row Y. As shown in FIG. 10A, if the print head 6 is not inclined, the inspection subpatterns 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 so as to be shifted in the sub-scanning direction.

  After printing the inspection pattern T10, the CPU 41 reads the inspection pattern T10 with the optical sensor 1a on the carriage 1. The CPU 41 corresponds to a “pattern reading unit” in the claims. When 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 inspection sub-patterns T11 and T12 are connected in one sub-scan. It is good also as reading only a part.

  The CPU 41 calculates the inclination of the print head 6 based on the deviation d11 in the sub-scanning direction between the inspection sub-patterns T11 and T12. That is, the CPU 41 corresponds to a “set value determination unit” in the claims. A “pattern reading unit” and a “setting value determination unit” as functional units of the CPU 41 are shown in FIG. When 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.

  θ = arcsin (d11 / Ln) (1)

  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 adjusting unit” in the claims. A “head adjusting unit” as a functional unit of the CPU 41 is shown in FIG.

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 test 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 two print heads 6a and 6b and their inspection sub-patterns T20a and T20b will be described. The CPU 41 that prints the inspection pattern T20 corresponds to a “pattern printing unit” in the claims.

  Each inspection sub-pattern T20a, T20b is formed by the nozzles at the upper end of the black nozzle row K of the print heads 6a, 6b. The design value of the interval between the nozzles at the upper end of the black nozzle row K of the print heads 6a and 6b in the sub-scanning direction SS 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 is 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 to be 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 deviation are indicated by broken lines.

  After printing the inspection subpatterns T20a and T20b, the CPU 41 reads the inspection subpatterns T20a and T20b with the optical sensor 1a on the carriage 1. That is, the CPU 41 corresponds to a “pattern reading unit” in the claims. The CPU 41 measures the interval L21 in the sub-scanning direction of the inspection sub-patterns T20a and T20b, and calculates the shift amount d21 of the print head 6b. A displacement d21 of the relative position of the print head 6b with respect to the print head 6a is obtained by the following equation.

  d21 = L21−L20 (2)

  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 “set 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 based on the print head that is most downstream in the sub-scanning direction.

B3. Adjustment of ink drop ejection timing:
FIG. 12 is an explanatory diagram illustrating an example of the inspection pattern T30. When adjusting the ink droplet ejection timing and adjusting the dot formation position in the main scanning direction, the test pattern T30 is printed. This inspection pattern T30 is composed of a plurality of vertical ruled lines each printed by nozzles of two nozzle rows, a nozzle row for adjusting the dot formation position in the main scanning direction and a reference nozzle row. . Here, a case will be described in which the formation position of the dots in the cyan nozzle row C of the print head in the main scanning direction is adjusted with reference to the black nozzle row K of the print head.

  Ruled lines T31 formed by the black nozzle row 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 inch. As a result, a plurality of sets of vertical ruled line pairs T33 are printed on the printing paper so that the relative positions of the black vertical ruled line T31 and the cyan vertical ruled line T32 are shifted by 1/1440 inches. Below the plurality of sets of vertical ruled line pairs T33, a number of a shift adjustment number is printed. The deviation 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) by the nozzle row that adjusts the dot formation position in the main scanning direction is corrected with an appropriate adjustment value, and is formed by the reference nozzle row. A state in which the dots substantially coincide with the positions in the main scanning direction. In the example of FIG. 12, a pair of vertical ruled lines having a shift adjustment number of 4 indicates a preferable correction state. The user observes the inspection pattern T30 and inputs the deviation adjustment number 4 from the input / output unit 240.

  When printing an image, the CPU 41 adjusts the ejection timing of the ink droplets from the cyan nozzle row based on the adjustment value when the misalignment adjustment number is 4 in the inspection pattern T30 of 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 dot formation position in the main scanning direction by each nozzle row is adjusted. In this embodiment, it is assumed that the dot formation positions of the nozzle rows of the 17 print heads are respectively adjusted with reference to the black nozzle row of the print head that is the most downstream in the sub-scanning direction.

  By performing the three adjustments as described above (FIG. 9), the positions of dots formed on the printing paper are changed in the main scanning direction (movement direction of the carriage 1) and the sub-scanning direction (printing paper feed direction). Can be adjusted appropriately.

C. Second embodiment:
FIG. 13 is an explanatory diagram illustrating the head adjustment driving 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, the print head can be attached at different positions in the direction perpendicular to the print paper at the position facing the print head 6, as indicated by an arrow A10. That is, the distance between the surface of the print head 6 on which 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.

  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 with a gap between the head base unit 80p and the carriage 1. The four screws 81c are provided with the direction perpendicular to the printing paper facing the print head as an axis. When the screw 81c is rotated, the distance between the carriage 1 and the head base unit 80p changes as indicated by an arrow A10. The end surface of the screw 81c facing the head adjustment drive unit 70p is provided with a concave curved surface.

  In addition to the configuration of the first embodiment, the head adjustment drive unit 70p of the second embodiment further includes an adjustment motor 70f to which the rotation shaft 70e is connected, an adjustment motor 70h to which the rotation shaft 70g is connected, and a rotation. An adjustment motor 70j to which the shaft 70i is connected and an adjustment motor 70l to which the rotation shaft 70k is connected are provided. Each of the rotating shafts 70e, 70g, 70i, and 70k is provided so as to be extendable and contractible in the axial direction, and the tip is provided in a convex curved shape. Since FIG. 13 is a side view, the rotation shaft 70i, the adjustment motor 70j, the rotation shaft 70k, and the adjustment motor 701 at positions overlapping with other adjustment motors and the rotation shaft are not shown.

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 almost 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 rotary shafts 70e, 70g, 70i, and 70k of the head adjustment drive unit 70p substantially coincide with each other.

  In such a state, each rotating shaft 70e, 70g, 70i, 70k extends and its tip comes into contact with the end of each screw 81c. The rotating shafts 70e, 70g, 70i, and 70k are rotated by the respective adjustment motors, whereby the screw 81c is 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.

  With such an embodiment, the distance between the surface of the print head 6 on which the nozzles are provided and the printing paper can be adjusted. The screw 81c corresponds to a “third adjusting portion” in the claims.

  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 driving unit 70 can easily operate these adjustment members. Further, 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 driving are performed. The rotating shafts 70a, 70c, 70e, 70g, 70i, and 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. 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. The axial direction is the moving direction of the carriage 1 and the moving direction of the adjustment driving unit 70. It intersects at 90 degrees plus or minus 10 degrees with respect to the plane defined by.

D. Third embodiment:
FIG. 14 is an explanatory diagram showing another test pattern used when adjusting the angle of each print head. When adjusting the angle of each print head (see step S10 in FIG. 9), patterns such as inspection patterns T40a and T40b can 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 of explanation, the two print heads 6a and 6b and their inspection patterns T40a and T40b will be described.

  Each of the test patterns T40a and T40b is 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 is to be arranged along the sub-scanning direction as shown in FIG. 3, if the print heads 6a and 6b are attached to the carriage 1 at an appropriate angle, the test pattern T40a. , T40b should be parallel to each other and their orientation should be parallel to the sub-scanning direction. However, as shown in FIG. 14, if the print head 6b is inclined with respect to the print head 6a, the test patterns T40a and T40b form a predetermined angle θ.

  After printing the inspection patterns T40a and T40b, the CPU 41 reads the inspection 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.

  Based on the above θ, the CPU 41 controls the adjustment motor 70b to adjust the inclination of the print head 6 (see FIGS. 7 and 5). It is assumed that the rotation angles of the 17 print heads are adjusted relative to the black nozzle row of the print head that is most downstream in the sub-scanning direction. Even in such an aspect, the rotation angle of each print head can be adjusted.

E. Variation:
The present invention is not limited to the above-described embodiments, and can be implemented in various forms without departing from the gist thereof. For example, the following modifications are possible.

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, it is also possible to adjust the tilt of the print head and the position in the sub-scanning direction using other means such as screws and worm gears. In the above embodiment, the distance between the print head and the printing paper is adjusted using screws (see FIG. 13). However, the distance between the print head and the printing paper can be adjusted using other means such as a worm gear or a cam.

  Further, the head adjustment driving unit 70 does not necessarily have to directly operate a member that changes the inclination or position of the print head as in the above embodiments (see FIGS. 5 and 13). That is, another member that transmits an operation may be provided between a member that changes the tilt or position of the print head and a member that the head adjustment driving unit 70 scans. However, the member operated by the head adjustment driving unit 70 is preferably a member operated by being rotated about the direction from the member toward the head adjustment driving unit 70 as an axis. If it is set as such an aspect, the head adjustment drive part 70 can operate the member easily.

In the above embodiment, the slide base unit 83 is provided so that the print head 6 can be fixed at different positions in the direction of feeding 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 feeding direction of 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 different positions in the direction crossing the main scanning direction. For example, if the print head is provided so as to be slidable in the direction crossing the sub-scanning direction, the following advantages are obtained. That is, as compared with the aspect in which the print head is provided so as to be slidable along the sub-scanning direction, the position in the sub-scanning direction can be finely adjusted by largely moving the print head.

  In the above embodiment, the rotation base unit 82 is provided so that the print head 6 can be fixed at different rotation angles with the direction perpendicular to the print paper at the position facing the print head 6 as an axis. (See FIG. 5). However, the rotation base unit 82 may be configured to be fixed at different rotation angles with a direction different from the direction perpendicular to the printing paper as an axis. That is, the printing apparatus only needs to include an adjustment unit that can fix the print head on the carriage at different rotation angles about a direction intersecting with a plane formed by a portion of the print medium facing the print head. “The plane formed by the portion of the print medium facing the print head” is the portion of the print medium transported by a transport means such as a roll that is in a state where dots are formed at a position facing the print head. 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 vertical.

E2. Modification 2:
In the above embodiment, the relative position of each print head is adjusted with reference to the print head that is 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 is adjusted with reference to the black nozzle row of the print head that is 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 is an ink color that is easily visible.

E3. Modification 3:
In the above embodiment, the carriage 1 is provided with a mechanism that can adjust the rotation angle of all the print heads and the position in the sub-scanning direction. However, the carriage 1 may have a print head that does not include such an adjustment mechanism. That is, it is only necessary to provide a mechanism that can adjust the rotation angle and the position in the sub-scanning direction for at least some of the print heads.

E4. Modification 4:
In the above embodiment, the head adjustment drive unit 70 moves independently of the carriage 1 (see FIG. 2). However, the slide shaft 71 may be provided on the carriage 1 and the head adjustment drive unit 70 may be provided so as to move integrally with the carriage 1. That is, the head adjustment driving unit 70 can be provided so as to be movable with respect to each print head on the carriage 1. However, the number of head adjustment driving units 70 is preferably 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.

  In the aspect in which the head adjustment driving 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 driving unit 70 is also two on the carriage. It is preferable to provide it so that it can move dimensionally. For example, it is preferable to provide a slide mechanism (slide shaft or slide guide) that can move on the carriage 1 in the main scanning direction and the sub-scanning direction.

E5. Modification 5:
The present invention is also applicable to a drum scan printer. The present invention can be applied not only to a so-called ink jet printer but also to a printing apparatus that prints an image by ejecting ink from a print head. Examples of such a printing apparatus include a facsimile machine and a copying machine.

E6. Modification 6:
In the above embodiment, a part of the configuration realized by hardware may be replaced with software, and conversely, a part of the configuration realized by software may be replaced by hardware. For example, a part of the function of the control circuit 40 (see FIG. 8) in the printer 200 can be executed by the computer 90.

1 is a perspective view illustrating an outline of a configuration of a printer as an embodiment of the present invention. Explanatory drawing explaining the structure of a printing part. FIG. 3 is an explanatory diagram showing an arrangement of nozzles on the lower surface of one print head. 2 is an explanatory diagram illustrating a schematic configuration of a carriage. FIG. The top view which shows a head base unit. Explanatory drawing which looked at the carriage from the back side. FIG. 3 is an explanatory diagram illustrating a head adjustment driving unit, a head base unit, and a print head. FIG. 2 is a block diagram illustrating a configuration of a printer centering on a control circuit as a control unit. 6 is a flowchart illustrating a procedure for adjusting a print head. FIG. 3 is an explanatory diagram showing an inspection pattern used when adjusting the angle of each print head. FIG. 5 is an explanatory diagram showing an inspection pattern used when adjusting the relative position between different print heads. Explanatory drawing which shows the example of the pattern for a test | inspection. Explanatory drawing which shows the head adjustment drive part, head base unit, and print head of 2nd Example. Explanatory drawing which shows the other pattern for a test | inspection used when adjusting the angle of each print head.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Carriage, 1a ... Optical sensor, 2 ... Nozzle plate, 2a ... Nozzle plate, 3 ... Sub tank, 3S ... Sub tank set, 3a-3f ... Sub tank, 6, 6a, 6b ... Print head, 9, 9a-9f ... Main Tank, 10A ... first inspection section, 10B ... second inspection section, 20 ... cap section, 30 ... wiper section, 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 shaft, 70b, 70d, 70f , 70h, 70j, 701 ... adjustment motor, 71 ... slide shaft, 72 ... transport motor, 73 ... pulley, 74 ... drive belt, 80, 80p ... head base Unit: 81 ... Fixed base unit, 81a, 81c ... Screw, 81b ... Projection, 82 ... Rotation base unit, 82a ... Shaft, 82b, 82c ... Slide pin, 82d ... Projection, 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 103, ink supply path, 200, printer, 210, paper supply unit, 211, roll paper holder, 212, spindle, 215, support pillar, 220, printing unit, 230, paper discharge unit, 231, holder, 232, etc. Spindle, 235, support pillar, 240, input / output unit, A2, arrow indicating the movement of the rotary base unit 82, A3, slide base Arrow indicating the movement of the unit 83, Ap... Indicating the range in the sub-scanning direction in which the nozzles are provided, C... Cyan nozzle row, K... Black nozzle row, Ln. ... Design value of the interval between the nozzles at the upper end of the black nozzle row, L21 ... Space between the 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 ejection timing of the ink droplets Inspection pattern, T31: Vertical ruled line formed by the reference nozzle row, T32: Vertical ruled line formed by the adjustment target nozzle row, T33: Vertical ruled line pair, T40, T40a, 40b ... Inspection for adjusting the rotation angle of the print head Y: Yellow nozzle row, d11: Deviation amount in the sub-scanning direction of the inspection sub-pattern, d21: Deviation amount in the sub-scanning direction of the inspection sub-pattern, θ: Deviation angle of the inspection sub-pattern.

Claims (8)

A printing apparatus 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 printing medium;
A control unit for controlling the dot recording head and a main scanning drive unit;
The carriage is
A first adjusting unit capable of fixing the print head on the carriage at different positions in a direction intersecting the main scanning direction;
A printing apparatus comprising: a second adjustment unit capable of fixing the print head on the carriage at different rotation angles with a direction intersecting with a plane formed by a portion of the print medium facing the print head as an axis. The printing apparatus according to claim 1,
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. The printing apparatus according to claim 1,
The carriage has a plurality of the print heads,
The first and second adjustment units are provided at least one for each print head, respectively.
The printing apparatus further includes an adjustment driving 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.
The number of the adjustment drive units is less than the number of the print heads. The printing apparatus according to claim 3,
The printing apparatus, wherein the adjustment driving unit can move in a direction crossing the main scanning direction independently of the carriage. The printing apparatus according to claim 3,
The first adjustment unit includes a first shaft portion that can be rotated to change the position of the print head in a direction intersecting with the main scanning direction.
The second adjustment unit includes a second shaft portion that can be rotated to change the rotation angle of the print head,
The direction of the rotation axis of each of the first and second shaft portions is a printing apparatus that is perpendicular to the main scanning direction and the moving direction of the adjustment driving unit. The printing apparatus according to claim 3, further comprising:
A sensor capable of reading an image recorded on a 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 controller is
While performing the main scanning, the two or more dot forming elements respectively form dots on the print medium, and are at different positions in the direction intersecting the main scanning direction, and two or more extending in the main scanning direction A pattern printing section for printing a pattern for inspection,
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 setting value of a position of the print head in a direction crossing the main scanning direction and a setting value of the rotation angle A set value determining unit to be determined;
A printing apparatus comprising: a head adjustment unit that causes the adjustment drive unit to drive the adjustment unit according to the set value. The printing apparatus according to claim 3, further comprising:
A sensor capable of reading an image recorded on a print medium;
The plurality of dot formation elements include two or more dot formation element rows respectively provided along a direction intersecting with the main scanning direction;
The controller is
A pattern printing unit that forms dots on the print medium at the same timing using the dot forming elements included in each dot forming element row, and prints a test pattern for each dot forming element row;
A pattern reading unit that reads the inspection pattern with the sensor;
Setting that determines at least one of a setting value of a position of the print head in a direction crossing the main scanning direction and a setting value of the rotation angle based on the inspection pattern data read by the sensor A value determining unit;
A printing apparatus comprising: a head adjustment unit that causes the adjustment drive unit to drive the adjustment unit according to the set value.   A method for adjusting a printing apparatus that prints an image by forming dots on a print medium, comprising: (a) a dot recording head having a plurality of dot forming elements for forming dots on the print medium; A step of preparing a printing apparatus for forming dots while performing main scanning by moving at least one of the carriage and the printing medium, and (b) an angle at which the print head is mounted on the carriage A step of adjusting an attachment angle with a direction intersecting a plane formed by a portion of the print medium facing the print head as an axis, and (c) an attachment position of the print head on the carriage. Adjusting a mounting position in a direction crossing the main scanning direction, and (d) a dot formation pattern by each dot forming element. And a step of adjusting the timing, the method of adjusting the printing apparatus.

Images