JP4539182B2 - Printing apparatus, computer program, printing system, and printing method - Google Patents

Description

  The present invention relates to a printing apparatus, a computer program, a printing system, and a printing method having a plurality of ink ejection unit groups.

2. Description of the Related Art Conventionally, as a printing apparatus having a plurality of ink ejection unit groups, an inkjet printer that includes a print head that ejects ink and performs printing by forming dots on a medium using the ejected ink is known (for example, Patent Document 1). reference). In such an ink jet printer, an image is printed at high speed on a large format printing paper (for example, JIS standard A row 0 paper, B row 0 paper or roll paper) using a plurality of print heads. Large inkjet printers are being considered. In such a large-scale ink jet printer, a plurality of print heads have carriages arranged at appropriate intervals in the paper transport direction so as to correspond to the size of paper to be printed. Then, the operation of ejecting ink from the print head while the carriage is moved by a predetermined moving mechanism and the operation of transporting the paper are alternately repeated, and each ink is ejected from the print head facing the transported paper. The image is printed. That is, first, a part of the image is printed by ejecting ink from the print head arranged on the upstream side in the transport direction, and the other part of the same image is printed from the print head arranged on the downstream side in the transport direction. By ejecting ink, it is possible to print one image using a plurality of different print heads.
Japanese Patent Laid-Open No. 2001-1510

  However, when one image is printed using a plurality of different print heads, dots formed by different print heads are mixed in one image. In particular, since the image is printed by alternately repeating the operation of ejecting ink from the print head while the carriage is moved by a predetermined moving mechanism and the operation of transporting the paper, the target position in the transport direction is the same as that of the dot. If the position to be formed varies for each print head, there is a problem that a good image may not be obtained.

  The present invention has been made in view of such a problem, and a printing apparatus capable of easily and accurately adjusting the formation position in the transport direction of dots formed by a plurality of print heads, It is an object to provide a computer program, a printing system, and a printing method.

The main invention includes: (a) a transport unit for transporting a print medium along a predetermined direction; and (b) a plurality of ink discharge units for forming dots by discharging ink droplets onto the print medium. A first ink ejection unit group and a second ink ejection unit group provided downstream in the predetermined direction from the first ink ejection unit group, and ejects ink droplets onto the printing medium to form dots. An ink discharge unit group unit including a second ink discharge unit group including a plurality of ink discharge units, and (c) for moving the ink discharge unit group unit along a moving direction intersecting the predetermined direction. And (d) controlling the moving unit and the transport unit to eject ink droplets from each of the ink ejecting units to cause the first ink ejecting unit group and the second ink ejecting unit group to Print one image A print pattern for controlling the transport amount of the print medium by the transport unit, and ejecting ink droplets from a predetermined ink discharge unit of the first ink discharge unit group Forming a dot row, transporting the print medium so that a predetermined ink discharge portion of the second ink discharge portion group faces an area where the first dot row is formed, and And a control unit that prints a print pattern configured by discharging ink from the predetermined ink discharge unit to form a second dot row .

  Other features of the present invention will be clarified by the description of the present specification and the accompanying drawings.

  At least the following will be made clear by the description of the present specification and the accompanying drawings.

(A) It has at least two ink ejection unit groups each including a plurality of ink ejection units for ejecting ink droplets to form dots on a print medium, and at least two of the ink ejection unit groups are arranged along a predetermined direction. An ink discharge unit group unit arranged side by side; (b) a moving unit for moving the ink discharge unit group unit along a moving direction intersecting the predetermined direction; and (c) the moving unit along the predetermined direction. A transport unit for transporting the print medium; and (d) controlling the moving unit and the transport unit to eject ink droplets from each of the ink ejecting units to at least two ink ejecting unit groups. A printing pattern for controlling the transport amount of the print medium by the transport unit, the ink ejection unit group unit being moved in the moving direction. Printing configured by dot rows along the moving direction corresponding to each ink ejection unit group by ejecting ink droplets from the ink ejection units provided in the different ink ejection unit groups while moving A printing apparatus comprising: a control unit capable of printing a pattern; and (e).
According to such a printing apparatus, the direction in which at least two ink ejection unit groups of the printing apparatus are arranged side by side coincides with the conveyance direction of the printing medium. For this reason, when printing one image with at least two ink ejection unit groups, dots formed on the print medium with ink ejected from the ink ejection units provided in each ink ejection unit group Can be adjusted by controlling the transport amount of the print medium.

In such a printing apparatus, it is preferable to print the print pattern by ejecting ink droplets from ink ejection units which are provided in different ink ejection unit groups and form a predetermined dot row included in the one image. .
According to such a printing apparatus, a print pattern for controlling the conveyance amount of the print medium by the conveyance unit is printed by ejecting ink droplets from the ink ejection units provided in different ink ejection unit groups. For this reason, the relative positions of the respective dot rows formed by different ink ejection unit groups are actually ejected by the ink ejection units provided in the respective ink ejection unit groups, and are printed by the conveyance unit. A print pattern is printed on the medium. That is, since it is possible to control the transport amount of the print medium based on the print pattern actually printed using the ink ejection unit group that forms the dot row whose relative position should be adjusted, the relative position of the dot row can be accurately determined. Can be adjusted.

In such a printing apparatus, the dot row formed in any one of the different ink discharge portion groups is used as a reference, and the reference dot row and other ink discharge portion groups are used. A measuring unit that measures a distance from the dot row in the predetermined direction, and the control unit controls a transport amount of the print medium by the transport unit based on the distance measured by the measuring unit; Is desirable.
According to such a printing apparatus, since it has the measurement part which measures the distance in the predetermined direction (conveyance direction) of the dot row formed in the different ink discharge part groups, the different ink discharge part groups It is possible to easily and accurately measure the distance in the transport direction of the dot row formed in this way. Further, since the conveyance amount of the print medium by the conveyance unit is controlled based on the distance measured by the measurement unit, the relative position of the dot row can be adjusted with high accuracy.

In such a printing apparatus, when there are two different ink ejection unit groups, the conveyance amount of the print medium by the conveyance unit is a sum of a preset conveyance amount and a measured distance, or It is desirable to make a difference.
Since the print pattern is printed on the print medium transported by the predetermined transport amount, the distance in the transport direction between the two dot rows formed by the two different ink ejection unit groups is the two formed The shift amount in the conveyance direction of the dot row is shown. According to the printing apparatus, since the carry amount is the sum or difference between the predetermined carry amount and the measured distance, the deviation amount is added to the default carry amount, or the deviation amount is added to the default carry amount. An image is printed with the removed conveyance amount. For this reason, since dot rows formed by different ink ejection unit groups are adjusted to appropriate relative positions, a good image can be printed even if one image is printed using a plurality of ink ejection unit groups. It is possible.

In such a printing apparatus, when there are three or more different ink discharge unit groups, the dot row formed by any one of the ink discharge unit groups is used as a reference, and the reference dot row and other ink discharge units The distance between the dot row formed in the group and the predetermined direction is measured by the measuring unit, and the sum of the measured distance and the preset predetermined transport amount, or It is desirable to make a difference.
Since the print pattern is printed on the print medium transported by the predetermined transport amount, the distance in the predetermined direction of the three or more dot rows formed by the three or more different ink ejection unit groups is formed. The shift amount in the transport direction of the three dot rows is shown. Then, according to the printing apparatus, with reference to the dot row formed in one of the ink ejection unit groups, the conveyance between the dot row serving as a reference and the dot row formed in the other ink ejection unit group Since the distance in the direction is measured, the shift amount of the other dot rows with respect to the reference dot row is measured. However, when an image is printed by a printing apparatus having three or more ink ejection unit groups, ink is ejected simultaneously from each ink ejection unit group onto the print medium. For this reason, when the measured shift amount of the dot row differs depending on the dot row, the transport amount of the print medium cannot be controlled for each. For this reason, an average value of the measured values is obtained, and the dot amount formed in any of the ink ejection unit groups is determined by setting the carry amount as the sum or difference of the average value and the predetermined carry amount. The position can also be adjusted in a well-balanced manner. Therefore, a good image can be printed even if one image is printed using three or more different ink ejection unit groups.

In such a printing apparatus, when the ink discharge unit group unit is moved in the movement direction, the reference dot row is transferred to the ink discharge unit group other than the ink discharge unit group that is most susceptible to vibration caused by the movement. It is desirable that ink droplets be ejected from the ink ejection part provided.
According to such a printing apparatus, since the reference dot row is formed by an ink ejection unit group other than the ink ejection unit group that is most susceptible to vibration due to movement, the reference dot row is substantially at the target position. It is formed. When printing a print pattern to control the transport amount of the print medium, the ink ejection unit group that ejects ink to form a reference dot row is other than the ink ejection unit group that is most susceptible to vibration due to movement. By using this ink ejection unit group, it is possible to more accurately form the reference dot row at the target position.

In such a printing apparatus, it is desirable that the ink ejection unit group that forms the reference dot row is an ink ejection unit group that is less susceptible to vibration due to the movement than the other ink ejection unit groups.
According to such a printing apparatus, the reference dot row is formed by the ink ejection unit group that is less susceptible to vibration due to movement, and is thus formed almost at the target position. When printing a print pattern for controlling the transport amount of the printing medium, the ink ejection unit group that ejects ink to form a reference dot row is subjected to vibration caused by movement from other ink ejection unit groups. By making the ink ejection unit group difficult to receive, it is possible to form the reference dot row at a more accurate position according to the target position, and to accurately set the distance from the dot row formed by other ink ejection unit groups. Can be measured.

In such a printing apparatus, the ink discharge unit group unit is moved by an external force, and the ink discharge unit group that forms the reference dot row is located at a position farthest from the site where the external force acts in the predetermined direction. It is desirable to be an ink ejection unit group other than the existing ink ejection unit group.
Since the size of the ink ejection unit having at least two ink ejection unit groups is larger than that of each ink ejection unit group, it is separated from the ink ejection unit group located near the portion where the external force acts on the ink ejection unit. Ink ejection unit groups located at the The behavior when the ink ejection unit is moved is likely to vibrate because the ink ejection unit group existing at the position farthest from the site where the external force acts is most unstable in the direction intersecting the movement direction. For this reason, by setting the ink ejection unit group that forms the reference dot row as an ink ejection unit group other than the ink ejection unit group that is located farthest from the site where the external force acts, the reference dot row Can be formed at a target position with higher accuracy.

In such a printing apparatus, it is desirable that the ink ejection unit group that forms the reference dot row is present in the predetermined direction at a position closest to the site where the external force acts.
According to such a printing apparatus, the dot row formed in the other ink ejection unit group is located at the position of the dot row formed in the ink ejection unit group that is present at the position closest to the site where the external force acts. It will be aligned. For this reason, on the basis of the dots formed in the ink ejection unit group that moves with more stable behavior, the conveyance amount of the print medium is set so that the positions of the dot rows formed in the other ink ejection units match. It is possible to print a better image because it is controlled.

In such a printing apparatus, it is preferable that the ink ejection unit group that forms the reference dot row is located closer to the center of the portion to which the external force acts than the other ink ejection unit group.
According to such a printing apparatus, the behavior of the center of the portion where the external force acts is most stable. For this reason, it is possible to more appropriately control the conveyance amount of the printing medium by using the position of the dot row formed by the ink ejection unit group located on the side closer to the center of the part where the external force acts as a reference. It is possible to print a better image.

In such a printing apparatus, it is desirable that the image can be printed on a plurality of types of print media, and the print pattern is printed according to the type of the print medium.
Even if the print medium is transported by the same processing due to the difference in friction coefficient depending on the type, the transport amount may be different. For this reason, a print pattern for controlling the transport amount of the print medium is printed according to the type of the print medium, and the transport amount of the print medium is controlled based on the printed print pattern. It is possible to transport the print medium with a transport amount suitable for the print medium. Therefore, it is possible to print a good image on any type of print medium.

In such a printing apparatus, it is preferable that the image can be printed in a plurality of types of print modes, and the print pattern is printed according to the type of the print mode.
The default transport amount of the print medium when printing an image may differ depending on the print mode. If the default transport amount is different, for example, the print mode with a small default transport amount may have higher transport accuracy than the print mode with a large default transport amount. For this reason, when printing in different print modes, there is a possibility that a good image cannot be printed even if the carry amount is similarly controlled. For this reason, printing patterns for controlling the transport amount of the print medium are printed in accordance with the print mode, and each type of print mode is controlled by controlling the transport amount of the print medium based on the printed print pattern. It is possible to transport the print medium with a transport amount suitable for the above. Therefore, it is possible to print a good image in any type of printing mode.

(A) having at least two ink ejection unit groups each including a plurality of ink ejection units for ejecting ink droplets to form dots on a print medium, and at least two of the ink ejection unit groups are arranged in a predetermined direction; An ink discharge unit group unit arranged side by side, (b) a moving unit for moving the ink discharge unit group unit by an external force along a moving direction intersecting the predetermined direction, and (c) the predetermined direction And (d) controlling the moving unit and the conveying unit to eject ink droplets from each of the ink ejecting units, so that at least two of the inks are conveyed. In the ejection unit group, it is possible to print one image on a plurality of types of print media in a plurality of types of print modes, and to control the transport amount of the print medium by the transport unit. A printing pattern comprising: a plurality of different ink ejection unit groups while moving the ink ejection unit group unit in the movement direction, and an ink ejection unit that forms a predetermined dot row included in the one image. By ejecting each ink droplet, a print pattern composed of dot rows along the moving direction corresponding to each ink ejection unit group is printed according to the type of print medium and the print mode, respectively. And (e) one of the different ink ejection unit groups among the different ink ejection unit groups so that the control unit controls the conveyance amount of the print medium by the conveyance unit. Measurement that measures the distance in the predetermined direction between the reference dot row and the dot row formed by another ink ejection unit group with the dot row formed in And (f), in which there are two different ink ejection unit groups, the conveyance amount of the print medium by the conveyance unit is measured as a preset default conveyance amount. When there are three or more different ink ejection unit groups, the ink ejection unit group is located at a position closest to the center of the site where the external force acts. The distance between the reference dot row and the dot row formed in another ink ejection unit group in the predetermined direction is measured by the measurement unit, and the measured distance The printing apparatus is characterized in that an average value is a sum or a difference between a predetermined conveyance amount set in advance.
According to such a printing apparatus, since all the effects described above are exhibited, the object of the present invention is achieved most effectively.

  (A) having at least two ink ejection unit groups each including a plurality of ink ejection units for ejecting ink droplets to form dots on a print medium, and at least two of the ink ejection unit groups are arranged in a predetermined direction; An ink discharge section group unit arranged side by side, (b) a moving section for moving the ink discharge section group unit along a moving direction intersecting the predetermined direction, and (c) along the predetermined direction. A transport unit for transporting the print medium, and (d) at least two ink ejecting units that control the moving unit and the transport unit to eject ink droplets from each of the ink ejecting units. In the group, the control unit capable of printing one image, and the printing apparatus having (e), the ink discharge unit group unit is moved in the moving direction, and the different inks are mutually different. By ejecting ink droplets from the ink ejection units included in the output unit group, the print medium is configured by dot rows along the moving direction corresponding to the respective ink ejection unit groups, and the transport unit transports the print medium. A computer program for realizing a function of printing a print pattern for controlling the amount can also be realized.

  Also, (A) a computer main body, (B) a printing apparatus connected to the computer main body having the following (a) to (d), and (a) ejecting ink droplets to form dots on the printing medium An ink discharge unit group unit having at least two ink discharge unit groups each including a plurality of ink discharge units for arranging the ink discharge units, the at least two ink discharge unit groups being arranged in a predetermined direction; and (b) the ink. A moving unit for moving the ejection unit group unit along a moving direction intersecting the predetermined direction; (c) a conveying unit for conveying the print medium along the predetermined direction; (d) the moving unit; By controlling the transport unit, it is possible to eject ink droplets from each of the ink discharge units and print one image in at least two of the ink discharge unit groups. And a printing pattern for controlling the transport amount of the printing medium, wherein ink droplets are respectively ejected from the ink ejection units included in the different ink ejection unit groups while moving the ink ejection unit group unit in the movement direction. And (C) having a control unit capable of printing a print pattern composed of dot rows along the moving direction corresponding to each ink discharge unit group. A printing system is also feasible.

  In addition, the ink discharge unit group includes at least two ink discharge unit groups each including a plurality of ink discharge units for discharging ink droplets to form dots on the print medium, and the at least two ink discharge unit groups are arranged in a predetermined direction. Each of the ink ejection unit groups is ejected from each of the ink ejection units of the different ink ejection unit groups while the arranged ink ejection unit group unit is moved along a moving direction that intersects the predetermined direction. A step of printing a print pattern composed of dot rows along the moving direction corresponding to each set of groups, and transporting the print medium along the predetermined direction based on the printed print pattern And a step of printing one image with at least two of the ink ejection unit groups by controlling the carry amount. It is.

=== Example of Printing Apparatus ===
FIG. 1 is a perspective view showing an outline of a color ink jet printer (hereinafter referred to as a color printer) 20 as a printing apparatus that prints by ejecting ink from a nozzle row serving as an ink ejection unit as an embodiment of the present invention. The color printer 20 is an inkjet printer capable of outputting a color image. For example, cyan ink (C) and light cyan ink (light cyan ink, LC) as cyan ink, and magenta ink (M) as magenta ink. ) And light magenta ink (light magenta ink, LM), yellow ink (Y), and black ink (K) are ejected onto various media such as printing paper to form dots. Is an ink jet type printer that prints the image The color ink is not limited to the above six colors, and for example, dark yellow (dark yellow, DY) may be used. Further, the color printer 20 is, for example, a roll paper in which a printing paper as a printing medium is wound in a roll shape, or a relatively large single-sheet printing paper such as JIS standard A row 0 paper or B row 0 paper. Is also supported. In the example of FIG. 1, the color printer 20 is provided with roll paper (hereinafter referred to as printing paper). The carriage 28 will be described later.

As shown in the figure, the color printer 20 includes a printing unit 3 that discharges ink and prints on the printing paper P, and a printing paper transport unit 5 that transports the printing paper along a predetermined transport direction. .
The printing unit 3 includes a carriage 28 as an ink discharge unit group that holds at least two print heads 36 as an ink discharge unit group having nozzle rows as a plurality of ink discharge units, and the carriage 28 is used as a printing paper. The carriage motor 30 is moved in a direction substantially orthogonal to the conveyance direction of P (hereinafter referred to as the carriage movement direction) and reciprocally moved. The carriage motor 30 and the carriage motor 30 constitute a moving mechanism and are driven by the carriage motor 30 to move the carriage 28. A metal traction belt 32 to be moved, two guide rails 34 for guiding the carriage 28, a linear encoder 17 fixed to the carriage 28, and a linear encoder having slits formed at predetermined intervals. And a code plate 19.

  Two guide rails 34 are provided along the carriage movement direction, and are vertically arranged at intervals in the transport direction, and are supported by frames (not shown) serving as bases at both left and right ends. Yes. At this time, in the two guide rails 34, the lower guide rail 341 is disposed in front of the upper guide rail 342. For this reason, the carriage 28 arranged so as to be bridged between the two guide rails 341 and 342 moves in an inclined state so that the upper part is positioned rearward and the lower part is positioned forward.

  A linear encoder code plate 19 is provided along the guide rail 342 on the upper guide rail 342 on which the carriage 28 is guided. The linear encoder code plate 19 is disposed so as to face the detection portion of the linear encoder 17 fixed to the carriage 28 that moves along the guide rail 34.

  The traction belt 32 is fixed to the left and right ends of the carriage 28 and formed in an annular shape, and is disposed at an intermediate position between the upper and lower guide rails 341 and 342 with an interval substantially equal to the length of the guide rails 341 and 342. The two pulleys 44 and 45 are stretched over. One of the pulleys 44 and 45 is fixed to the shaft of the carriage motor 30.

  In the carriage 28 arranged so as to be bridged between the two guide rails 341 and 342, the traction belt 32 is fixed at substantially the center in the vertical direction at the left and right end portions. In the color printer 20, the power of the carriage motor 30 is transmitted by the traction belt 32, and the carriage 28 is pulled by the traction belt 32 by the transmitted power and moves in the carriage movement direction along the guide rail 34. When the carriage 28 moves, ink is ejected from the eight print heads 36 provided on the carriage 28, thereby printing an image on the printing paper P conveyed by the printing paper conveyance unit 5.

  In the present embodiment, eight print heads 36 are provided on the carriage 28, and these print heads 36 have a plurality of nozzles n for ejecting ink, and are controlled by a head control unit 63 (see FIG. 6) to be described later. Ink is ejected from the nozzle n. The surface of the print head 36 facing the printing paper P has a plurality of nozzle rows N as an ink discharge section in which a plurality of nozzles n are arranged in a row along the transport direction. It is arranged along the direction. The arrangement of the print head 36 and the nozzles n will be described later.

  The printing paper transport unit 5 is provided on the back side of the two guide rails 34. The printing paper transport unit 5 transports the printing paper P below the lower guide rail 341 and the roll paper holding unit 35 that rotatably holds the printing paper P together with the holder 27, and above the upper guide rail 342. A roll paper transport unit 37 and a platen 26 along which the print paper P transported between the roll paper holding unit 35 and the roll paper transport unit 37 are arranged. The platen 26 has a flat surface extending over the entire width of the printing paper P to be conveyed, and this flat surface is inclined so as to face each print head 36 mounted on the carriage 28 that moves in an inclined state at equal intervals. It is provided in the state.

  The holder 27 has a shaft body 27a serving as a rotating shaft in a state where the printing paper P is held, and a guide disk 27b for preventing meandering of the printing paper P to be supplied on both ends of the shaft body 27a. Are provided.

  The roll paper transport unit 37 includes a paper transport roller 24 for transporting the print paper P, a sandwiching roller 29 that is disposed opposite the paper transport roller 24 and sandwiches the print paper P, and a paper transport roller. And a conveyance motor 31 for rotating 24. A drive gear 40 is provided on the shaft of the transport motor 31, and a relay gear 41 that meshes with the drive gear 40 is provided on the shaft of the paper transport roller 24. The power of the transport motor 31 is provided via the drive gear 40 and the relay gear 41. Is transmitted to the paper transport roller 24. That is, the printing paper P held by the holder 27 is nipped between the paper conveyance roller 24 and the nipping roller 29 and conveyed along the platen 26 by the conveyance motor 31. A rotary encoder 16 having a disk-shaped encoder code board 18 (FIG. 2) having a plurality of radial slits is provided on the shaft of the transport motor 31. The conveyance amount of the printing paper is controlled based on an output signal from the rotary encoder 16.

=== Encoder ===
Next, the rotary encoder 16 will be described. FIG. 2 is an explanatory diagram schematically showing the configuration of the rotary encoder 16.
The rotary encoder 16 shown in FIG. 2 includes a light emitting diode 16a, a collimator lens 16b, and a detection processing unit 16c. The detection processing unit 16c includes a plurality of (for example, four) photodiodes 16d, a signal processing circuit 16e, and, for example, two comparators 16fA and 16fB.

  When the voltage VCC is applied across the light emitting diode 16a via a resistor, light is emitted from the light emitting diode 16a. This light is condensed into parallel light by the collimator lens 16 b and passes through the rotary encoder code board 18. At this time, every time the printing paper is conveyed a predetermined distance (for example, 1/180 inch (1 inch = 2.54 cm)) at the irradiation position of the light emitted from the light emitting diode 16a, the encoder code board 18 is used. A slit is provided to detect the output.

  The parallel light that has passed through the rotary encoder code board 18 enters each photodiode 16d through a fixed slit (not shown) and is converted into an electrical signal. The electric signals output from the four photodiodes 16d are processed in the signal processing circuit 16e, the signals output from the signal processing circuit 16e are compared in the comparators 16fA and 16fB, and the comparison result is output as a pulse. Pulses ENC-A and ENC-B output from the comparators 16fA and 16fB are output from the rotary encoder 16.

  FIG. 3A is a timing chart showing the waveforms of two output signals of the rotary encoder 16 during forward rotation of the transport motor, and FIG. 3B shows the waveforms of the two output signals of the rotary encoder 16 during reverse rotation of the transport motor. It is a timing chart.

  As shown in FIGS. 3A and 3B, the phase of the pulse ENC-A and the pulse ENC-B differ by 90 degrees in both cases of the forward rotation and the reverse rotation of the transport motor. When the transport motor 31 is rotating forward and the paper is transported from the bottom to the top along the transport direction, the pulse ENC-A is 90 degrees out of phase with the pulse ENC-B, as shown in FIG. 3A. When the conveyance motor 31 is reversely rotated, the phase of the pulse ENC-A is delayed by 90 degrees from the pulse ENC-B as shown in FIG. 3B. One cycle T of the pulse ENC-A and the pulse ENC-B is equal to the time during which the transport motor 31 moves the slit interval of the rotary encoder code board 18.

  By counting the output pulses of the pulses ENC-A and ENC-B and transporting the printing paper, the printing paper P can be moved to a predetermined position. Further, it is possible to control the transport distance of the printing paper P that is actually transported based on the transport amount data of the command data input from the host computer 90 and the slit interval of the encoder code board 18.

  Further, by equally dividing the pulse output from the rotary encoder 16, it is possible to control the amount of paper transport with a higher resolution than the slit of the rotary encoder code board 18. For example, when the pulse output from the rotary encoder 16 is divided into four, the conveyance motor can be controlled with an accuracy of 1440 dpi, and the conveyance amount of the printing paper can be controlled.

=== Configuration of Print Head ===
The configuration of the print head 36 will be described with reference to FIGS. FIG. 4 is an explanatory diagram for explaining an arrangement of nozzles included in the print head 36, and FIG. 5 is a diagram illustrating an arrangement of a plurality of adjacent print heads 36 and a positional relationship between nozzle rows included in the print heads 36. is there.

  As shown in FIG. 4, the print head 36 has six nozzle rows N in which a plurality of nozzles n are arranged in a straight line along the transport direction. In this embodiment, the nozzle row N is for each ink color to be ejected, such as a black nozzle row Nk, a cyan nozzle row Nc, a light cyan nozzle row Nlc, a magenta nozzle row Nm, a light magenta nozzle row Nlm, and a yellow nozzle row Ny. There is a line, but it is not limited to this.

  The black nozzle row Nk has 180 nozzles n1 to n180, and each nozzle n is provided with a piezo element (not shown) as a driving element for driving each nozzle n to eject ink droplets. Yes. The nozzles n1,..., N180 of the black nozzle row Nk are arranged at a constant nozzle pitch k · D along the transport direction. Here, D is a dot pitch in the transport direction, and k is an integer of 1 or more. The dot pitch D in the transport direction is equal to the pitch of horizontal dot lines (hereinafter referred to as raster lines) in which dots are arranged in the carriage movement direction. Hereinafter, the integer k representing the nozzle pitch k · D is simply referred to as “nozzle pitch k”. In the example of FIG. 4, the nozzle pitch k is 4 dots. However, the nozzle pitch k can be set to an arbitrary integer.

  The same applies to the cyan nozzle row Nc, the light cyan nozzle row Nlc, the magenta nozzle row Nm, the light magenta nozzle row Nlm, and the yellow nozzle row Ny. That is, each nozzle row N has 180 nozzles n1 to n180, and is arranged at a constant nozzle pitch k · D along the transport direction.

  At the time of printing, the printing paper P is intermittently transported by a predetermined transporting amount by the printing paper transporting unit 5, and the carriage 28 moves in the carriage moving direction during the intermittent transporting, and ink droplets are ejected from each nozzle n. Is discharged. However, when printing by an interlace method for printing a natural image or the like depending on the printing method, not all nozzles n are always used, and only some nozzles n are used. There is also.

  Of the eight print heads 36a to 36h provided on the carriage 28, four print heads 36 are arranged along the transport direction and arranged in two rows at intervals. Two print head arrays composed of four print heads 36 are arranged side by side in the carriage movement direction. In the print head row arranged in two rows, one print head row 36b, 36d, 36f, 36h is upstream of the other print head row 36a, 36c, 36e, 36g by a distance of about one print head in the transport direction. Arranged on the side. That is, the eight print heads 36a located first from the downstream side of the one print head row and the second print head 36c located so as not to line up in the carriage movement direction. In between, the print head 36b located in the most downstream side of the other print head row | line | column is arrange | positioned. The 180th nozzle of the print head 36a located on the most downstream side of one print head row and the first nozzle of the print head 36b located on the most downstream side of the other print head row are nozzles in the transport direction. They are arranged so as to be separated by the pitch k · D. The 180th nozzle of the print head 36b located on the most downstream side of the other print head row and the first nozzle of the print head 36c located second from the downstream side of the one print head row are transported. The nozzles are arranged so as to be separated by a nozzle pitch k · D in the direction. As described above, the print heads 36 arranged in two rows are arranged such that the first nozzle and the 180th nozzle of the print heads adjacent to each other in the transport direction are separated by the nozzle pitch k · D, respectively. . That is, from the first nozzle of the print head 36a located on the most downstream side in the two print head rows to the 180th nozzle of the print head 36h located on the most upstream side, both are the nozzle pitch k · D in the transport direction. Just placed away. Therefore, in one movement of the carriage 28, for example, when dots are formed at the same position in the carriage movement direction with respect to the printing paper P in each nozzle row N having eight print heads, the nozzle rows of the eight print heads 36 are formed. The dots formed by N are continuously formed at an equal pitch.

  Of the eight print heads 36 provided on the carriage 28, the four print heads 36 a to 36 d are disposed above the traction belt 32, and the remaining four print heads 36 e to 36 h are disposed below the traction belt 32. Has been. Since the positional relationship between the four print heads 36 is the same, the positional relationship between the upper four print heads 36a to 36d will be described as an example here.

  By the way, the power (traction force) of the carriage motor 30 as an external force for moving the carriage 28 acts on the portion where the traction belt 32 is fixed to the carriage 28, that is, the engaging portions S1 and S2. In the carriage 28, the portion close to the action line SL connecting the engaging portions S1 and S2 transmits the traction force more directly, so that vibration during movement of the carriage 28 is small and vibration occurs as the distance from the action line SL increases. Becomes larger. That is, the print heads 36 that are most susceptible to vibration due to the movement of the carriage 28 are the print heads 36a and 36h that are disposed at the positions farthest from the action line SL. The center of the action line SL, that is, the print head closest to the midpoint 46 of the engaging portions S1 and S2, and the nozzle row N closest to the midpoint 46 are least susceptible to vibration due to the movement of the carriage 28. It will be. Further, between two different print heads 36, one of the two print heads 36 on the side closer to the action line SL is less susceptible to vibration due to movement of the carriage 28 than the other print head 36. Become.

  In FIG. 4, the ink colors of each nozzle row are black nozzle row Nk, cyan nozzle row Nc, light cyan nozzle row Nlc, magenta nozzle row Nm, light magenta nozzle row Nlm, and yellow nozzle row Ny from the left side of the drawing. However, the present invention is not limited to this, and the ink colors of the nozzle arrays N may be arranged in other arrangement orders.

  Further, on the upper side of the carriage 28, a reading unit 11 (FIG. 6) capable of reading a print pattern to be described later and converting it into an electric signal, and a signal processing unit 12 (FIG. 6) for performing a predetermined process on the converted electric signal. ) Is provided. The reading unit 11 is an image reading device having a CCD sensor or the like, for example. The signal processing unit 12 performs various kinds of signal processing on the electrical signal output from the reading unit 11 to detect, for example, the density or edge of the image, or measure the distance between a plurality of edges included in the image. Is possible. That is, the print pattern information acquisition unit 13 corresponds to the measurement unit according to the claims.

=== Example of Overall Configuration of Printing System ===
Next, an example of the overall configuration of the printing system will be described with reference to FIGS. FIG. 6 is a block diagram illustrating a configuration of a printing system including the color printer 20 described above. FIG. 7 is a block diagram showing a configuration of the image processing unit 38.

  This printing system includes a computer 90 and a color printer 20 as an example of a printing apparatus. The printing system including the color printer 20 and the computer 90 can also be called a “printing apparatus” in a broad sense. The system includes the computer 90, the color printer 20, the CRT 21, a display device (not shown) such as a liquid crystal display device, an input device such as a keyboard and a mouse, a drive device such as a flexible drive device and a CD-ROM drive device. It is constructed from etc.

  In the computer 90, an application program 95 operates under a predetermined operating system. The operating system incorporates a video driver 91, and an application program 95 that performs image retouching or the like performs desired processing on the image to be processed, and also sends an image to the CRT 21 via the video driver 91. it's shown.

  The color printer 20 includes print data and the like from the application program 95, and includes an image processing unit 38, a system controller 54 as a control unit that controls the operation of the entire color printer 20, a main memory 56, and an EEPROM 58. ing. The system controller 54 further includes a carriage motor drive circuit 61 for driving the carriage motor 30, a transport motor drive circuit 62 for driving the transport motor 31, a head control unit 63 for controlling the print head 36, A rotary encoder 16 for controlling the carry amount and a print pattern information acquisition unit 13 are connected.

  As shown in FIGS. 1 and 6, the color printer 20 described above has a plurality of print heads 36. In the present embodiment, eight print heads 36 are arranged on the carriage 28 at intervals in the vertical direction and the horizontal direction, and each print head 36 is configured to be detachable from the printer body. Yes.

  Further, each print head 36 includes an ink tank 67 for containing ink supplied to the print head 36 provided in the print head 36. The print head 36 includes the head control unit 63 and the image processing unit 38 described above, and each print head 36 can be controlled based on a reference drive signal.

  When the application program 95 issues a print command, the image processing unit 38 provided in the color printer 20 receives the image data from the application program 95 and converts it into print data PD. As shown in FIG. 7, the image processing unit 38 includes a resolution conversion module 97, a color conversion module 98, a halftone module 99, a rasterizer 100, a UI printer interface module 102, and a raster data storage unit 103. A color conversion lookup table LUT, a buffer memory 50, and an image buffer 52.

  The resolution conversion module 97 plays a role of converting the resolution of the color image data formed by the application program 95 into a corresponding print resolution based on information such as the print mode received together with the image data. The image data thus converted in resolution is still image information composed of three color components of RGB. The color conversion module 98 converts RGB image data for each pixel into multi-tone data of a plurality of ink colors that can be used by the color printer 20 while referring to the color conversion lookup table LUT.

  The color-converted multi-gradation data has, for example, 256 gradation values. The halftone module 99 performs so-called halftone processing to generate halftone image data. Here, for example, halftone is an image that is divided into predetermined regions composed of a plurality of regions where pixels can be formed, and the density in each region is divided into large dots, medium dots at a plurality of regions constituting the region. The density of each area is expressed by whether or not to form either a dot or a small dot.

  The halftone image data is rearranged in the desired data order by the rasterizer 100 and output to the raster data storage unit 103 as final print data PD. At this time, a signal for forming dots for printing a halftone portion of the image is assigned to the print head 36 located on the side closer to the pulling belt 32 described above.

  On the other hand, the user interface display module 101 provided in the computer 90 has a function of displaying various user interface windows related to printing and a function of receiving user input in these windows. For example, the user can instruct the user interface display module 101 about the type, size, print mode, and the like of the print paper.

  The UI printer interface module 102 has a function as an interface between the user interface display module 101 and the color printer 20. Interpret the command instructed by the user through the user interface and send various commands COM to the system controller 54 etc. Conversely, interpret the command COM received from the system controller 54 etc. and perform various displays on the user interface Or For example, the instruction related to the type, size, etc. of the printing paper received by the user interface display module 101 is sent to the UI printer interface module 102. The UI printer interface module 102 interprets the instructed instruction, and the system controller The command COM is transmitted to 54.

  The UI printer interface module 102 also has a function as a print mode setting unit. That is, the UI printer interface module 102 is based on the print information received by the user interface display module 101, that is, the resolution of the image to be printed, the information on the nozzle used for printing, the information on the data indicating the transport direction feed amount, and the like. Then, the print mode as the recording mode is determined, print data PD corresponding to this print mode is generated by the halftone module 99 or the rasterizer 100, and is output to the raster data storage unit 103. The print data PD output to the raster data storage unit 103 is temporarily stored in the buffer memory 50, converted into data corresponding to the nozzles, and stored in the image buffer 52. The system controller 54 of the color printer 20 controls the carriage motor drive circuit 61, the carry motor drive circuit 62, the head control unit 63, and the like based on the information of the command COM output from the UI printer interface module 102, and Printing is performed by driving the nozzles of the respective colors provided in the print head 36 based on the data. Here, as the printing mode, for example, a high image quality mode in which dots are recorded using various interlace methods in which the number of nozzles forming one raster line, the conveyance amount of printing paper that is intermittently conveyed, and the like are different, There is a high-speed mode that records dots without using a method.

=== Drive of print head ===
Next, driving of the print head 36 will be described with reference to FIG.
FIG. 8 is a block diagram showing the configuration of the drive signal generator provided in the head control unit 63 (FIG. 6), and FIG. 9 shows the original drive signal ODRV and print signal PRT showing the operation of the drive signal generator. (I) It is a timing chart of drive signal DRV (i). In FIG. 8, the drive signal generation unit 200 includes a plurality of mask circuits 204, an original drive signal generation unit 206, and a drive signal correction unit 230. The mask circuit 204 is provided corresponding to a plurality of piezo elements for driving the nozzles n1 to n180 of the print head 36, respectively. In FIG. 8, the number in parentheses at the end of each signal name indicates the number of the nozzle to which the signal is supplied.

The original drive signal generator 206 generates an original drive signal ODRV that is commonly used for the nozzles n1 to n180. The original drive signal ODRV is a signal that includes two pulses of a first pulse W1 and a second pulse W2 within a carriage movement period for one pixel, and is a reference discharge signal for discharging ink from each nozzle. . That is, all the nozzles of each print head 36 eject ink based on the same original drive signal ODRV. When it is detected by the output of the linear encoder 17 that the carriage 28 has reached a predetermined position, the output of the original drive signal ODRV is started. For this reason, when ink is ejected from each nozzle row of each print head 36 and dot rows are formed at the same target position on the printing paper, the original drive is performed so that the positions of the dot rows in the carriage movement direction match. The output timing of the signal ODRV is adjusted. That is, before this adjustment is made, a theoretical value for ejecting ink from the predetermined position to the target position of the printing paper is set as an initial value, the relative position between the carriage 28 and the printing paper, and each print head. The interval is set based on the interval in the carriage movement direction, the interval in the carriage movement direction of the nozzle row of each print head, and the set value is stored in the EEPROM.
The drive signal correction unit 230 can change the position where each dot is formed by shifting the timing of the drive signal waveform shaped by the mask circuit 204 back and forth.

  As shown in FIG. 8, the input serial print signal PRT (i) is input to the mask circuit 204 together with the original drive signal ODRV output from the original drive signal generator 206. The serial print signal PRT (i) is a 2-bit serial signal per pixel, and each bit corresponds to the first pulse W1 and the second pulse W2. The mask circuit 204 is a gate for masking the original drive signal ODRV in accordance with the level of the serial print signal PRT (i). That is, when the serial print signal PRT (i) is 1 level, the mask circuit 204 passes the corresponding pulse of the original drive signal ODRV as it is and supplies it as the drive signal DRV to the piezo element, while the serial print signal PRT (i ) Is 0 level, the corresponding pulse of the original drive signal ODRV is cut off.

  As shown in FIG. 9, the original drive signal ODRV sequentially generates a first pulse W1 and a second pulse W2 in each pixel period T1, T2, and T3. The pixel section has the same meaning as the carriage movement period for one pixel.

  As shown in FIG. 9, when the print signal PRT (i) corresponds to 2-bit pixel data “1, 0”, only the first pulse W1 is output in the first half of one pixel interval. Thereby, a small ink droplet is discharged from a nozzle and a small dot (small dot) is formed in a to-be-printed body. When the print signal PRT (i) corresponds to the 2-bit pixel data “0, 1”, only the second pulse W2 is output in the second half of one pixel interval. As a result, medium-sized ink droplets are ejected from the nozzles, and medium-sized dots (medium dots) are formed on the printing medium. When the print signal PRT (i) corresponds to 2-bit pixel data “1, 1”, the first pulse W1 and the second pulse W2 are output in one pixel section. Thereby, a large ink droplet is ejected from the nozzle, and a large dot (large dot) is formed on the printing medium. As described above, the drive signal DRV (i) in one pixel section is shaped to have three different waveforms according to three different values of the print signal PRT (i), and based on these signals. The print head 36 can form dots of three types.

=== Position adjustment in transport direction of dots formed by different print heads ===
The color printer 20 described above has eight print heads 36a to 36h, and each print head 36 prints a separate image, and of course, a plurality of print heads 36 are used to print one image. It is also possible to print. When printing one image using a plurality of print heads 36, dots formed by ink ejected from nozzles of different print heads 36 are mixed in the printed image. For this reason, it is necessary to adjust the positions of the dots formed by the ink ejected from the nozzles of the different print heads 36. In particular, when printing one image using a plurality of print heads 36 arranged side by side in the transport direction, dots are formed by the print head 36 provided on the upstream side in the transport direction, and then on the downstream side. The printing paper is conveyed to a position facing the provided print head 36, and dots are formed by the print head 36 provided on the downstream side. For this reason, each raster line constituting one image formed using a plurality of different print heads 36 is constituted by dots formed by different print heads. Thus, when one raster line is composed of dots formed by different print heads, dots formed by different print heads must be printed unless the printing paper is conveyed by an appropriate conveyance amount. There may be a shift in the relative position between them, and a good image may not be printed. For this reason, the color printer 20 of the present embodiment adjusts the positional deviation in the transport direction of the dots formed by the different print heads 36 when printing one image using the different print heads 36. Therefore, a predetermined print pattern is printed using the print head 36 that forms one image, and the conveyance amount of the paper is controlled based on the printed print pattern.

<Print pattern used for position adjustment in dot conveyance direction>
A print pattern for adjusting the position in the transport direction of dots formed by each print head 36 used when printing one image using different print heads 36 will be described.

  Since the transport amount of paper varies depending on the type of print medium on which an image is printed, the print mode, and the like, the print pattern is printed for each type of print medium and print mode. Then, based on each printed print pattern, a transport amount for printing on a predetermined print sheet in a predetermined print mode is set, and the system controller 54 transports the print sheet based on the set transport amount. To control. The print pattern is printed using nozzles provided on different print heads 36, which are used to form dots constituting the same raster line when an image is actually printed in each print mode. The Here, for example, printing is performed in a printing mode (hereinafter referred to as a 4-pass overlap printing mode) in which ink is ejected from nozzles of each of the four print heads 36 and one raster line is formed by the formed dots. A description will be given of the setting of the conveyance amount when performing the process.

  FIG. 10 is a diagram for explaining the relative positions of the nozzle and the printing paper when printing an image in the 4-pass overlap printing mode. In FIG. 10, for convenience, it is assumed that each print head has seven nozzle rows, and one nozzle row among the nozzle rows of each print head is arranged linearly along the transport direction. It is assumed that In FIG. 10, the print paper P is stopped and the print head 36 is moved. However, in the actual printing operation, the print paper P is transported and the print paper P and the print paper P are transported. The relative position changes. In the following description, the first print head to the fourth print head are referred to in order from the print head 36 located on the downstream side in the transport direction, and the first print head is connected to the print head 36a on the most downstream side of the color printer 20 described above. The fourth print head corresponds to the fourth print head 36d from the most downstream side. The nozzles of each print head 36 are referred to as a first nozzle to a seventh nozzle in order from the nozzle located on the downstream side in the transport direction.

  When printing in the 4-pass overlap printing mode, a plurality of dots are formed by ejecting ink from all nozzles in the first forward path (first pass) when the carriage 28 reciprocates in the carriage movement direction. To do. At this time, the dot to be formed is the first dot in the carriage movement direction. The first dots are formed along the carriage movement direction, and are spaced apart from each other by 3 dots.

  Next, the printing paper P is conveyed by 7 dots, the carriage 28 is moved in the backward direction (second pass), and ink is ejected from all nozzles to form dots. In the raster line formed at this time, adjacent dots in the carriage movement direction are spaced apart from each other by 3 dots. The raster lines formed on the return path are formed at positions adjacent to the raster lines formed on the forward path in the transport direction. Further, the dots constituting the raster line formed in the return path are located between the dots formed in the forward path in the carriage movement direction.

  Next, the printing paper P is again conveyed by 7 dots, the carriage 28 is moved in the forward direction (third pass), and ink is ejected from all nozzles to form dots. In the raster line formed at this time, adjacent dots in the carriage movement direction are spaced apart from each other by 3 dots. The raster lines formed in the second forward pass are formed at positions adjacent to the raster lines formed in the return pass in the transport direction. Further, the dots constituting the raster line formed in the second forward pass are formed between the dots formed in the first forward pass and the dots formed in the return pass in the carriage movement direction. . In this way, after the printing paper P is conveyed by 7 dots, the carriage 28 is moved and ink is ejected from each nozzle to form a raster line in which the dot interval is 3 dots apart. repeat. When such a printing operation is executed, as shown in the drawing, the first nozzle of the fourth print head in the first pass, the first nozzle of the third print head in the fifth pass, and the second print head in the ninth pass. The first nozzle and the first nozzle of the 13th pass first print head are aligned in the carriage movement direction. That is, the images printed in such a printing mode are the first nozzles of each print head, the second nozzles, the third nozzles, the fourth nozzles, the fifth nozzles, the sixth nozzles, The same raster line is composed of dots formed by 7 nozzles.

  That is, it is only necessary to set the carry amount and control based on the set carry amount so as to match the formation positions in the carrying direction of the dots formed by the nozzles of the same number provided in each print head 36.

  FIG. 11 is a diagram illustrating an example of a print pattern used for setting the carry amount. This print pattern 10 is a print pattern 10 for setting a transport amount for a 4-pass overlap print mode composed of four raster lines formed along the moving direction of the carriage 28. Each raster line is printed by the nozzle of the same number provided in the first print head to the fourth print head. Here, the first nozzle provided in each print head is used.

  In the printing method of the printing pattern 10, the printing paper P is first transported to a position where the leading end is located sufficiently downstream of the first nozzle of the fourth printing head (FIG. 10). At this time, when the roll paper is arranged over the entire area facing the carriage, this operation is not necessary. Here, the printing paper P on which the printing pattern 10 is printed is preferably a printing paper used when an image is actually printed. In this example, since the 4-pass overlap printing mode is a printing mode for printing a so-called high-quality image, for example, photographic paper is used as the printing paper.

  When the printing paper P is transported, the first movement (first pass) of the carriage 28 is executed, and ink is ejected from only the first nozzle of the fourth print head 36d, along the carriage movement direction by a predetermined length. A raster line (hereinafter referred to as a first raster line) is printed. At this time, the first raster line to be printed is a solid line.

  Next, when the carriage 28 is moved, the first nozzle of the third print head 36c is based on a preset conveyance amount (predetermined conveyance amount) so as to face the area where the first raster line is formed. The printing paper P is conveyed. That is, the printing paper P is intermittently moved four times by a distance corresponding to seven dots with a preset conveyance amount. At this time, the distance of 28 dots at a time is not conveyed because it is the same as the conveying method in the case of actually printing an image. That is, even if the transport motor 31 is driven in the same manner, if the transport amount at one time is large, an error is likely to occur, and the smaller the transport amount at one time tends to be transported with high accuracy. The transport method is the same as when printing an image. At the same time as the printing paper P is transported, the carriage 28 is moved in the backward direction without ejecting ink from all the nozzles. The movement of the carriage 28 is also executed in order to match the operation when forming the print pattern 10 with the operation when actually printing an image. That is, when an image is actually printed, the operation of forming dots with the first nozzles of the third head 36c is aligned with the dots already formed with the first nozzles of the fourth print head 36d. Done in That is, when the image is printed by reciprocating the carriage 28, the fifth pass moves in the forward direction, and therefore the operation for forming the print pattern 10 and the operation for actual printing are combined. Yes. Thus, by combining the operation for actually printing an image and the operation for printing the print pattern 10, it is possible to set a more accurate transport amount.

  Then, the printing paper P is intermittently moved four times by a distance of 7 dots, and the carriage 28 is moved in the backward direction, and then the carriage 28 is moved in the forward direction, while the first print head 36c is moved in the first direction. Ink is ejected from only the nozzles to print a second raster line having a predetermined length along the carriage movement direction. The second raster line printed at this time is a broken line.

  Next, the printing paper P is moved intermittently four times by a distance of 7 dots by a preset conveyance amount, and the carriage 28 is moved in the backward direction without discharging ink from all the nozzles. . Thereafter, while moving the carriage 28 in the forward direction, ink is ejected only from the first nozzles of the second print head 36b to print a third raster line having a predetermined length along the carriage movement direction. The third raster line printed at this time is a one-dot chain line.

  Further, the printing paper is intermittently moved four times by a distance of 7 dots by a preset conveyance amount, and the carriage is moved in the backward direction without discharging ink from all the nozzles. Thereafter, while moving the carriage 28 in the forward direction, ink is ejected only from the first nozzles of the first print head 36a to print a fourth raster line having a predetermined length along the carriage movement direction. The fourth raster line printed at this time is a two-dot chain line.

  The four raster lines constituting the printed pattern 10 printed in this way are printed in a superimposed manner when the positions of the dots formed by the print heads in the transport direction coincide with the target position. Therefore, it becomes one. Further, when the positions of the dots formed by each print head in the transport direction are deviated from the target position, as shown in FIG. 11, two or more lines separated in the transport direction are formed.

=== Method of setting the carry amount based on the print pattern ===
A method of setting the carry amount to match the formation positions in the carrying direction of dots formed by the nozzles of the same number provided in each print head will be described using the print pattern shown in FIG.

  The printed print pattern 10 indicates the amount of positional deviation between the raster lines formed by the four print heads 36a to 36d in the transport direction. For this reason, using one of the raster lines as a reference, the deviation amount between the reference raster line and another raster line is measured, and the conveyance amount when conveying the printing paper P is corrected by the deviation amount. That's fine. However, the proper transport amount for each print head does not always match. In the present embodiment, since one image is printed by the four print heads, ink is ejected from the nozzles provided in the four print heads to the conveyed printing paper P. That is, the printing paper P is transported by the same transport amount with respect to the four print heads, and the single printing paper P cannot be transported by the transport amount corresponding to each print head. . For this reason, in this embodiment, the shift amount of each of the other raster lines with respect to the reference raster line is measured, and the average value of the measured shift amounts is obtained and used as the correction amount when transporting the printing paper.

  The reference raster line is desirably formed of ink ejected from nozzles of a print head that can eject ink in the most stable state when the carriage 28 moves. The print head 36 that can eject ink in the most stable state is, for example, a print head 36 that is less susceptible to vibration due to movement of the carriage 28. In the present embodiment, as described above, the midpoint 46 in the line of action SL of the traction force F of the carriage 28 is the least susceptible to vibration, and among the four print heads 36 a to 36 d located on the upper side of the carriage 28. The fourth print head 36d closest to the midpoint 46 of the action line SL is least susceptible to vibration. Therefore, the first raster line formed by the fourth print head 36d is used as a reference. In the present embodiment, since the positions of the dots formed by the four print heads in the transport direction are aligned, the first raster formed by the fourth print head 36d closest to the midpoint 46 of the action line SL. Although the line is used as a reference, the print head that forms the reference raster line is not limited to the fourth print head 36d. For example, when printing one image with the first print head 36a and the third print head 36c, and with the second print head 36b and the third print head 36c, of the two print heads, It is desirable to use the raster line formed by the third print head 36c located on the side closer to the action line SL as a reference. At this time, since there are two raster lines constituting the print pattern, the measured shift amount becomes the correction amount as it is.

  Further, when one image is printed using eight print heads provided on the carriage 28, a raster line formed by either the fourth print head or the fifth print head may be used as a reference. In other words, the print head 36 that forms the reference raster line is disposed at the position farthest from the action line SL, and the print heads excluding the first print head 36a and the eighth print head 36h that are susceptible to vibration due to the movement of the carriage. Any raster line formed at 36 may be used.

  Then, the conveyance amount setting method based on the print pattern 10 is continuously executed from the print operation of the print pattern 10. FIG. 12 is a diagram for explaining a method for setting the carry amount.

  First, when a user inputs a command signal for setting a conveyance amount together with information on printing paper and printing mode from, for example, a connected computer (S101), the printer 20 is controlled by the system controller 54. The print pattern 10 composed of four raster lines is printed by the above-described method (S102). When the four raster lines are formed, the printing paper P is transported to the position where the reading unit 11 of the printing pattern information acquisition unit 13 can read the printing pattern 10 under the control of the system controller 54 (S103).

  When the printing paper P is conveyed to a predetermined position, the system controller 54 reads the printing pattern 10 by the reading unit 11 of the printing pattern information acquisition unit 13 (S104), and the signal processing unit 12 based on the read information. The distance between each raster line is measured (S105). The reading unit 11 is a camera using, for example, a CCD sensor, acquires density information for each photodiode constituting the CCD sensor at a resolution according to the resolution of the CCD sensor, and converts each density information into an electrical signal. Reading by doing. Therefore, the signal processing unit 12 recognizes the position corresponding to the photodiode from which the electrical signal indicating high density is output as a raster line, and exists between the plurality of photodiodes from which the electrical signal indicating high density is output. By converting the distance from the number of photodiodes, it is possible to measure the amount of deviation between raster lines.

  When the distance between the raster lines is measured, the number of raster lines constituting the print pattern 10 is detected, and the signal processing unit 12 determines whether there are three or more raster lines (S106). If it is determined that there are three or more raster lines, the signal processing unit 12 calculates an average value thereof (S107). At this time, each raster line is identified by the signal processing unit 12 in association with the formed print head 36. Then, the amount of deviation between the reference raster line and the other raster lines is measured, and the sum of them is obtained. Here, the sum of the deviation amounts is obtained as a deviation amount to be measured, with one of the two directions in the conveyance direction being a positive value and the other being a negative value depending on the deviation direction. Next, when the print pattern is printed, the obtained sum is divided by the number of times the paper is intermittently conveyed after the first raster line is formed until the last raster line is formed. The Thereby, the average value of the shift amount in each intermittent conveyance is calculated.

  The calculated average value is associated with the input information such as print paper and print mode as correction information, and is stored in the EEPROM 58 by the system controller 54. On the other hand, when it is determined that the number of raster lines constituting the print pattern 10 is less than 3, the measured shift amount is stored in the EEPROM 58 as correction information as it is (S108).

  By the way, since the conveyance amount of the printing paper P is controlled by the rotary encoder 16, the rotation amount of the conveyance motor 31 to be rotated is the rotary amount that is already set for conveying the printing paper P. The number of pulses of the encoder 16 is set. For this reason, the average value stored in the EEPROM 58 is the number of pulses corresponding to the resolution of the rotary encoder 16. That is, the number of pulses corresponding to the average value of the calculated deviation amounts is stored in the EEPROM 58, and when printing an image, the stored number of pulses is added to the number of pulses indicating the predetermined carry amount. Alternatively, the carry amount is corrected by subtracting the stored pulse number from the pulse number indicating the predetermined carry amount.

FIG. 13 is a diagram for explaining processing when an image is printed.
When a print command signal is input to the color printer 20 (S201), the system controller 54 acquires information indicating the print mode and the type of print medium to be printed from the information included in the print command signal (S202). The system controller 54 acquires correction information indicating the correction amount of the conveyance amount stored in the EEPROM 58 based on the acquired information such as the print mode and the type of print medium (S203). The system controller 54 adds the obtained correction amount to the predetermined transport amount or subtracts it from the default transport amount to calculate a transport amount suitable for the print mode, the type of print medium, and the like (S204). Thereafter, under the control of the system controller 54, the color printer 20 executes a printing process while conveying the printing paper based on the calculated conveyance amount (S205).

  In the present embodiment, the print pattern formed by the nozzles that form the same raster line has been described. However, the nozzles that form the print pattern are not necessarily nozzles that form the same raster line. For example, the print pattern is printed by the first nozzle of the fourth print head, the second nozzle of the third print head, the third nozzle of the second print head, and the fourth nozzle of the first print head. In this case, the amount of deviation is calculated based on the physical distance (for example, design value) of each nozzle used at the time of printing.

=== Print pattern example for setting the transport amount of different print modes ===
FIG. 14 is a diagram for explaining the relative positions of the nozzle and the paper when printing an image in the two-pass overlap printing mode. In this example, the amount of conveyance in a printing mode (hereinafter referred to as a two-pass overlap printing mode) in which ink is ejected from the nozzles of each of the two print heads and one raster line is formed by the formed dots. The setting will be described. Similarly to the example described above, each nozzle array of each print head has seven nozzles, and one nozzle array among the nozzle arrays of each print head is arranged linearly along the transport direction. Explain that it is.

  In the two-pass overlap printing mode, the first nozzle of the first print head 36a and the seventh nozzle of the fourth print head 36d in the first forward path (first pass) when the carriage 28 reciprocates in the carriage movement direction. A plurality of dots are formed by ejecting ink from the nozzles except for. At this time, the dot to be formed is the first dot in the carriage movement direction. The first dots are formed along the carriage movement direction, and are spaced apart from each other by one dot.

  Next, the printing paper P is conveyed by 13 dots, the carriage 28 is moved in the backward direction (second pass), and the nozzles excluding the first nozzle of the first print head 36a and the seventh nozzle of the fourth print head 36d. Ink is ejected from dots to form dots. The formed raster lines are also separated by one dot. The raster line formed in the return path is formed at a position adjacent to the raster line formed in the forward path in the transport direction. Further, the dots constituting the raster line formed in the return path are formed in the middle of the dots formed in the forward path in the carriage movement direction.

  In this way, after transporting the printing paper P by 13 dots, the carriage 28 is moved and ink is ejected from the nozzles excluding the first nozzle of the first printing head 36a and the seventh nozzle of the fourth printing head 36d. Then, the operation of forming raster lines in which the dot intervals are separated by one dot is repeated. When such a printing operation is executed, as shown in FIG. 14, the first nozzle of the third print head 36c in the first pass, the second nozzle of the first print head 36a in the fifth pass, and 1 The first nozzles of the fourth print head 36d in the pass and the second nozzles of the second print head 36b in the fifth pass are aligned in the carriage movement direction. That is, an image printed in such a print mode includes the first nozzle of the third print head 36c, the second nozzle of the first print head 36a, and the first nozzle of the fourth print head 36d. The same raster line is formed by dots formed by the second nozzles of the second print head 36b.

  That is, the first nozzle of the third print head 36c and the second nozzle of the first print head 36a, the first nozzle of the fourth print head 36d, and the second nozzle of the second print head 36b. In order to match the formation position of the dots formed in the transport direction, the transport amount may be set and controlled based on the set transport amount.

  According to such a printing apparatus, the direction in which the eight print heads 36 of the color printer 20 are arranged side by side coincides with the conveyance direction of the printing paper P. For this reason, when one image is printed by the plurality of print heads 36, the relative positions of the dots formed on the print paper P by the ink ejected from the nozzles provided in the respective print heads 36 are determined. It can be adjusted by controlling the transport amount of the printing paper P.

  Further, a print pattern for controlling the transport amount of the print paper P by the print paper transport unit 5 is printed by ejecting ink droplets from nozzles provided in different print heads 36. For this reason, the printing paper conveyed by the printing paper conveyance unit 5 by actually ejecting ink from the nozzles of each printing head 36 at the relative positions of the raster lines formed by the different printing heads 36. A print pattern is printed on P. That is, since it is possible to control the transport amount of the printing paper based on the print pattern actually printed using the print head 36 that forms the raster line whose relative position is to be adjusted, the relative position of the raster line can be accurately determined. It is possible to adjust.

  Further, since the print pattern information acquisition unit 13 for measuring the distance in the transport direction of raster lines formed by different print heads 36 is provided, the transport of raster lines formed by different print heads is provided. It is possible to measure the distance in the direction easily and accurately. Further, since the transport amount of the print paper P by the print paper transport unit 5 is controlled based on the distance measured by the print pattern information acquisition unit 13, the relative position of the raster line can be adjusted with high accuracy. Is possible.

  In addition, since the print pattern is printed on the printing paper P that has been transported by the predetermined transport amount, the distance in the transport direction between the two raster lines formed by the two different print heads 36 is 2 The amount of misalignment in the transport direction of the book raster line is shown. According to the color printer 20, since the carry amount is the sum or difference between the predetermined carry amount and the measured distance, the deviation amount is added to the default carry amount or the deviation amount is added to the default carry amount. The image is printed with the transport amount from which the is removed. For this reason, since raster lines formed by different print heads 36 are adjusted to appropriate relative positions, even if one image is printed using a plurality of print heads 36, a good image can be printed. Is possible.

  On the other hand, the distance in the transport direction of three or more raster lines formed by three or more different print heads 36 indicates the amount of misalignment in the transport direction of the three raster lines formed. According to the color printer 20, with reference to the raster line formed by one of the print heads 36, the conveyance direction between the reference raster line and the raster line formed by another print head 36. Since the distance at is measured, the amount of misalignment of the other raster lines with respect to the reference raster line is measured. However, when an image is printed by the color printer 20 having three or more print heads 36, ink is simultaneously ejected from each print head 36 onto the printing paper. For this reason, when the measured shift amount of the raster line differs depending on the raster line, the transport amount of the printing paper P cannot be controlled for each. For this reason, the position of the raster line formed by any print head 36 is obtained by calculating the average value of the measured values and setting the transport amount as the sum or difference of the average value and the predetermined transport amount. Can be adjusted in a well-balanced manner. Therefore, even if one image is printed using three or more different print heads 36, a good image can be printed.

  Furthermore, since the reference raster line is formed by the print head 36 other than the print head 36 that is most susceptible to vibration due to the movement of the carriage 28, that is, the print head 36 that is less susceptible to vibration, the reference raster line is almost the same. Formed at the target position. At this time, by setting the print head 36 that forms the reference raster line as a print head other than the print heads 36a and 36h that are located farthest from the action line SL on which the external force acts, the reference raster line Can be formed at a target position with higher accuracy. Further, the positions of the raster lines formed by the other print heads 36 coincide with each other based on the raster line formed by the print heads 36d and 36e existing closest to the action line SL on which the external force acts. If the transport amount of the printing paper is controlled, a better image can be printed. Furthermore, by using the position of the raster line formed by the print head 36 located on the side closer to the midpoint 46 of the action line SL on which the external force is applied as the most stable behavior, the printing paper P It is possible to more appropriately control the transport amount of the image, and it is possible to print a better image.

  Further, even if the printing medium is conveyed by the same processing due to a difference in friction coefficient depending on the type, the actual conveyance amount may be different. For this reason, a print pattern for controlling the transport amount of the print medium is printed according to the type of the print medium, and the transport amount of the print medium is controlled based on the printed print pattern. It is possible to transport the print medium with a transport amount suitable for the print medium. Therefore, it is possible to print a good image on any type of print medium.

  The default transport amount of printing paper when printing an image may differ depending on the printing mode. If the default transport amount is different, for example, the print mode with a small default transport amount may have higher transport accuracy than the print mode with a large default transport amount. Even if the amount is controlled, a good image may not be printed. For this reason, a print pattern for controlling the transport amount of the print paper P is printed according to the print mode, and the transport amount of the print paper P is controlled based on the printed print pattern. It is possible to transport the printing paper P with a transport amount suitable for the print mode. Therefore, it is possible to print a good image in any type of printing mode.

=== Other Embodiments ===
The present invention is not limited to the above-described embodiment, and can be implemented in various modes without departing from the gist thereof. For example, the following modifications are possible.

  (1) 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 with hardware. Also good.

  (2) The present invention is generally applicable to printing apparatuses that eject ink droplets, and can be applied to various printing apparatuses other than color inkjet printers. For example, the present invention can be applied to an ink jet facsimile machine and a copying machine.

  (3) In the above embodiment, the example in which the printing system is configured by the color printer 20, the computer 90, the display device, the input device, the drive device, and the like has been described, but the present invention is not limited to this. For example, the printing system may be configured by the computer 90 and the color printer 20, and the printing system may not include any of the display device, the input device, and the drive device.

  For example, the color printer 20 may have a part of the functions or mechanisms of the computer 90, the display device, the input device, and the drive device. As an example, the color printer 20 includes an image processing unit that performs image processing, a display unit that performs various displays, and a recording medium attachment / detachment unit for attaching / detaching a recording medium that records image data captured by a digital camera or the like. It is good also as a structure which has.

  In addition, the computer program for controlling the printer in the above-described embodiment is stored in the memory of the printer controller, and the printer controller executes the computer program to achieve the printer operation of the above-described embodiment. Good.

  The printing system realized in this way is a system superior to the conventional system as a whole system.

1 is a perspective view illustrating an example of a configuration of a color printer according to the present invention. An explanatory view schematically showing the configuration of the rotary encoder 16. FIG. 3A is a timing chart showing the waveforms of two output signals of the rotary encoder 16 during forward rotation of the transport motor, and FIG. 3B shows the waveforms of the two output signals of the rotary encoder 16 during reverse rotation of the transport motor. Timing chart. Explanatory drawing for demonstrating the arrangement | sequence of the nozzle which a print head has. The figure which shows the positional relationship of arrangement | positioning of several adjacent print heads, and the nozzle row which these print heads have. 1 is a block diagram illustrating a configuration of a printing system including a color printer. The block diagram which shows the structure of an image processing unit. The block diagram which shows the structure of the drive signal generation | occurrence | production part provided in the head control unit (FIG. 6). 4 is a timing chart of an original drive signal ODRV, a print signal PRT (i), and a drive signal DRV (i) showing operations of the drive signal generator. The figure for demonstrating the relative position of the nozzle and printing paper at the time of printing an image in 4 pass overlap printing mode. The figure which shows an example of the printing pattern used in order to set conveyance amount. The figure for demonstrating the setting method of conveyance amount. The figure for demonstrating the process at the time of printing an image. The figure for demonstrating the relative position of the nozzle and printing paper at the time of printing an image in 2 pass overlap printing mode.

Explanation of symbols

3 printing section, 5 printing paper transport section, 10 printing pattern, 11 reading section, 12 signal processing section, 13 printing pattern information acquisition section, 16 rotary encoder, 16a diode, 16b collimator lens, 16c detection processing section, 16d photodiode , 16e signal processing circuit, 16fA comparator, 16fB comparator, 17 linear encoder, 18 encoder code board, 19 linear encoder code board, 20 color printer, 21 CRT, 24 paper transport roller, 26 platen, 27 holder, 27a Shaft body, 27b disk, 28 carriage, 29 clamping roller, 30 carriage motor, 31 transport motor, 32 traction belt, 34 guide rail, 341 lower guide rail, 342 upper guide rail, 35 low Paper holding unit, 36 print head, 36a to 36h print head, 37 roll paper transport unit, 38 image processing unit, 40 drive gear, 41 relay gear, 44 pulley, 45 pulley, 46 midpoint of action line, 50 buffer memory, 52 Image buffer, 54 System controller, 56 Main memory, 58 EEPROM, 61 Carriage motor drive circuit, 62 Carriage motor drive circuit, 63 Head control unit, 67 Ink tank, 90 Computer, 91 Video driver, 95 Application program, 97 Resolution conversion Module, 98 color conversion module, 99 halftone module, 100 rasterizer, 101 user interface display module, 102 UI printer interface module, 103 Star data storage unit, 200 drive signal generation unit, 204 mask circuit, 206 original drive signal generation unit, 230 drive signal correction unit, Nc cyan nozzle row, Nk black nozzle row, Nlc light cyan nozzle row, Nlm light magenta nozzle row, Nm Magenta nozzle row, Ny yellow nozzle row, P printing paper, T1 pixel section, W1 pulse, W2 pulse, n nozzle, LUT lookup table, ODRV original drive signal, S1 engagement portion, S2 engagement portion, SL action line

Claims (15)

(A) a transport unit for transporting the print medium along a predetermined direction;
(B) a first ink ejection unit group including a plurality of ink ejection units for ejecting ink droplets onto the print medium to form dots, and a downstream side in the predetermined direction from the first ink ejection unit group A second ink ejection unit group provided, the second ink ejection unit group including a plurality of ink ejection units for ejecting ink droplets onto the printing medium to form dots. Unit,
(C) a moving unit for moving the ink discharge unit group unit along a moving direction crossing the predetermined direction;
(D) By controlling the moving unit and the transport unit, ink droplets are ejected from each of the ink ejection units , and one image is generated by the first ink ejection unit group and the second ink ejection unit group. Can be printed,
A printing pattern for controlling the conveyance amount of the print medium by the conveyance unit, and ejecting ink droplets from a predetermined ink ejection unit of the first ink ejection unit group to form a first dot row, The print medium is transported so that a predetermined ink discharge portion of the second ink discharge portion group faces an area where the first dot row is formed, and the predetermined ink discharge portion of the second ink discharge portion group A control unit that prints a print pattern configured by discharging ink from the second dot row to form a second dot row;
A printing apparatus comprising: The printing apparatus according to claim 1,
A printing apparatus that prints the print pattern by ejecting ink droplets from ink ejection units that are provided in different ink ejection unit groups and that form predetermined dot rows included in the one image. The printing apparatus according to claim 2,
Among the different ink discharge unit groups, the dot row formed in any one of the ink discharge unit groups is used as a reference, and the dot row used as a reference and the dot row formed in another ink discharge unit group It has a measuring unit that measures the distance in a predetermined direction,
The printing apparatus, wherein the control unit controls a conveyance amount of the print medium by the conveyance unit based on a distance measured by the measurement unit. The printing apparatus according to claim 3.
When there are two different ink ejection unit groups, the transport amount of the print medium by the transport unit is the sum or difference of a preset default transport amount and the measured distance. Characteristic printing device. The printing apparatus according to claim 3.
When there are three or more different ink discharge unit groups, the dot row formed by any one of the ink discharge unit groups is used as a reference, and the reference dot row is formed by another ink discharge unit group. The distance in the predetermined direction with respect to each dot row is measured by the measuring unit, and the sum or difference between the average value of the measured distances and a preset transport amount set in advance is used. Characteristic printing device. The printing apparatus according to any one of claims 3 to 5,
The reference dot row is an ink ejection provided in the ink ejection unit group other than the ink ejection unit group that is most susceptible to vibration caused by the movement of the ink ejection unit group unit in the movement direction. A printing apparatus, wherein ink drops are ejected from a portion. The printing apparatus according to claim 6.
The printing apparatus according to claim 1, wherein the ink ejection unit group that forms the reference dot row is an ink ejection unit group that is less susceptible to vibration due to the movement than the other ink ejection unit groups. The printing apparatus according to claim 6 or 7,
The ink discharge unit group unit is moved by an external force, and the ink discharge unit group that forms the reference dot row is located in the predetermined direction at a position farthest from the site to which the external force acts. A printing apparatus comprising an ink ejection unit group other than the group. The printing apparatus according to claim 7.
The printing apparatus according to claim 1, wherein the ink discharge unit group that forms the reference dot row is located in a position closest to a portion to which the external force acts in the predetermined direction. The printing apparatus according to claim 8 or 9, wherein
The printing apparatus according to claim 1, wherein an ink ejection unit group that forms the reference dot row is located closer to a center of a portion to which the external force acts than the other ink ejection unit group. The printing apparatus according to any one of claims 1 to 10,
The image can be printed on a plurality of types of the print media,
The printing apparatus is characterized in that the printing pattern is printed according to the type of the printing medium. The printing apparatus according to any one of claims 1 to 11,
The image can be printed in a plurality of printing modes,
The printing apparatus is characterized in that the printing pattern is printed according to the type of the printing mode. (A) a transport unit for transporting the print medium along a predetermined direction;
(B) a first ink ejection unit group including a plurality of ink ejection units for ejecting ink droplets onto the print medium to form dots, and a downstream side in the predetermined direction from the first ink ejection unit group A second ink ejection unit group provided, the second ink ejection unit group including a plurality of ink ejection units for ejecting ink droplets onto the printing medium to form dots. Unit,
(C) a moving unit for moving the ink discharge unit group unit along a moving direction crossing the predetermined direction;
And controlling the moving unit and the conveying unit to cause ink droplets to be ejected from each of the ink ejection units, so that one image is generated by the first ink ejection unit group and the second ink ejection unit group. To a printing device that can print
Forming ink droplets from predetermined ink ejection portions of the first ink ejection portion group to form first dot rows;
Transporting the print medium such that a predetermined ink discharge portion of the second ink discharge portion group is opposed to a region where the first dot row is formed;
Printing a print pattern configured by discharging ink from the predetermined ink discharge portion of the second ink discharge portion group to form a second dot row;
And a computer program for realizing a function of printing a print pattern for controlling the transport amount of the print medium by the transport unit. (A) a computer body;
(B) a printing apparatus connected to the computer body and having the following (a) to (d);
(A) a transport unit for transporting the print medium along a predetermined direction;
(B) a first ink ejection unit group including a plurality of ink ejection units for ejecting ink droplets onto the print medium to form dots, and a downstream side in the predetermined direction from the first ink ejection unit group A second ink ejection unit group provided, the second ink ejection unit group including a plurality of ink ejection units for ejecting ink droplets onto the printing medium to form dots. unit,
(C) a moving unit for moving the ink discharge unit group unit along a moving direction intersecting the predetermined direction;
(D) By controlling the moving unit and the transport unit, ink droplets are ejected from each of the ink ejection units , and one image is generated by the first ink ejection unit group and the second ink ejection unit group. Can be printed,
A printing pattern for controlling the conveyance amount of the print medium by the conveyance unit, and ejecting ink droplets from a predetermined ink ejection unit of the first ink ejection unit group to form a first dot row, The print medium is transported so that a predetermined ink discharge portion of the second ink discharge portion group faces an area where the first dot row is formed, and the predetermined ink discharge portion of the second ink discharge portion group A control unit that prints a print pattern that is formed by ejecting ink from the second dot row,
A printing system comprising: (A) a transport unit for transporting the print medium along a predetermined direction;
(B) a first ink ejection unit group including a plurality of ink ejection units for ejecting ink droplets onto the print medium to form dots, and a downstream side in the predetermined direction from the first ink ejection unit group A second ink ejection unit group provided, the second ink ejection unit group including a plurality of ink ejection units for ejecting ink droplets onto the printing medium to form dots. Unit,
(C) a moving unit for moving the ink discharge unit group unit along a moving direction crossing the predetermined direction;
And controlling the moving unit and the conveying unit to cause ink droplets to be ejected from each of the ink ejection units, so that one image is generated by the first ink ejection unit group and the second ink ejection unit group. In a printing apparatus that enables printing, it is a method of printing a print pattern for controlling the conveyance amount of the print medium by the conveyance unit,
Forming ink droplets from predetermined ink ejection portions of the first ink ejection portion group to form first dot rows;
Transporting the print medium such that a predetermined ink discharge portion of the second ink discharge portion group is opposed to a region where the first dot row is formed;
Printing a print pattern configured by discharging ink from the predetermined ink discharge portion of the second ink discharge portion group to form a second dot row;
Including printing method.

Images