JP2017144656A - Printing device and printing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enhance detection accuracy of a sensor unit provided in a carriage more than before to provide high-grade print.SOLUTION: A printing device includes: the carriage mounting a print head and reciprocating; and the sensor unit mounted to the carriage and detecting a pattern formed on a sheet end or a sheet. The printing device corrects the detection of the sensor unit when the carriage accelerates or decelerates.SELECTED DRAWING: Figure 8

Description

  The present invention relates to a printing apparatus in which a unit is mounted on a carriage.

  Patent Document 1 discloses a printing apparatus that includes a sensor unit in a carriage on which a print head that ejects ink is mounted, and that can detect an end portion and a pattern of a sheet using the sensor unit.

JP 2008-068952 A

  In the apparatus of Patent Document 1, when the carriage posture slightly changes due to the acceleration or deceleration of the carriage, the sensor unit posture also changes accordingly. The change in the attitude of the sensor unit due to the acceleration / deceleration of the carriage is a slight error factor in sensor detection, and may become a new problem when aiming to further improve printing accuracy.

  The present invention has been made in view of the above conventional example, and an object thereof is to provide a printing apparatus and a printing method capable of performing high-quality printing by increasing detection accuracy of a sensor unit provided in a carriage more than ever.

  In order to achieve the above object, the printing apparatus of the present invention includes the following configuration.

  That is, a carriage that has a print head mounted thereon and reciprocates, a sensor unit that is mounted on the carriage and detects a pattern formed on an end portion or a sheet of the sheet, and the carriage accelerates detection by the sensor unit. Or it has the correction means which correct | amends when decelerating, It is characterized by the above-mentioned.

  According to another aspect of the present invention, there is provided a method of performing printing by reciprocating a carriage having a print head and a sensor unit mounted thereon. A printing method is provided, wherein a pattern formed on a sheet is detected, and the detection by the sensor unit is corrected when the carriage is accelerated or decelerated.

  Therefore, according to the present invention, sensor detection with higher accuracy than before can be performed by correcting the detection error of the sensor unit accompanying the change in the posture of the carriage. Thereby, high-quality printing can be realized.

1 is an external perspective view showing an outline of a configuration of an inkjet printing apparatus that is an embodiment of the present invention. It is sectional drawing which shows the structure of a sensor unit. FIG. 2 is a block diagram illustrating a control configuration of the printing apparatus illustrated in FIG. 1. It is the schematic which shows the pattern for identification of a correction value. It is a flowchart which shows the sequence which identifies a correction value. It is the schematic which showed a mode that the edge part of a sheet | seat was detected, performing printing. It is a flowchart which shows the sequence which detects a printing edge part, performing printing. It is a figure which shows the table of the correction value to which the drive profile of a carriage at the time of printing of a predetermined print width, and the speed and acceleration in each carriage position contribute, respectively. FIG. 6 is a schematic diagram showing an internal structure of a carriage according to a second embodiment. It is a figure which shows the attitude | position change of a carriage, and an acceleration correction value. It is a flowchart which shows the sequence which calculates the correction value for every acceleration. It is a graph which shows the correction value obtained when scanning with a predetermined acceleration. It is the schematic explaining the motion of the edge part sensor which detects a correction value identification pattern. It is a flowchart which shows the sequence which identifies a correction value. It is a figure which shows the acceleration correction value in reciprocating printing. FIG. 6 is a schematic diagram illustrating a configuration of a print head 5 according to a fourth embodiment. It is the schematic shown about the registration adjustment pattern and its reading method. It is a flowchart which shows the execution sequence of registration adjustment.

  Hereinafter, embodiments of the present invention will be described more specifically and in detail with reference to the accompanying drawings. However, the relative arrangement and the like of the constituent elements described in this embodiment are not intended to limit the scope of the present invention only to those unless otherwise specified.

  The “sheet” includes not only paper used as a print medium but also a medium capable of receiving ink, such as cloth, plastic film, metal plate, glass, ceramics, wood, and leather.

  Further, “ink” (sometimes referred to as “liquid”) should be interpreted widely as the definition of “print”. Therefore, by being applied on the sheet, it can be used for forming an image, a pattern, a pattern, or the like, processing the sheet, or processing the ink (for example, solidification or insolubilization of the colorant in the ink applied to the sheet). It shall represent a liquid.

<Outline of printing apparatus (FIGS. 1 to 3)>
FIG. 1 is a schematic perspective view of an ink jet printing apparatus (hereinafter referred to as a printing apparatus) which is a typical embodiment of the present invention.

  As shown in FIG. 1, for example, a sheet M such as print paper is sandwiched between a conveyance roller 1 and a pinch roller 2, held on the platen 3, and conveyed in the conveyance direction (sub-scanning direction) Y. A print head 5 that discharges ink is mounted on the carriage 4, and ink is discharged from the print head 5 onto the sheet M while reciprocating in the main scanning direction X along the carriage rail 6. Form an image.

  A sensor unit 7 is provided on the side surface of the carriage 4 so as to face the sheet M, and the sensor unit 7 detects the sheet M and the platen 3. Then, the edge of the sheet M is detected using the average value of the detected values as a threshold for detecting the edge of the sheet M in the main scanning direction X. The sensor unit 7 is a multi-sensor capable of detecting the position of a prescribed pattern formed on the sheet and reading the density of the pattern in addition to the function as an end sensor.

  FIG. 2 is a side sectional view showing the configuration of the sensor unit 7. This sectional view is a view of the sensor unit 7 as viewed from the main scanning direction X, and is along the sub-scanning direction Y.

  As shown in FIG. An LED 8 and a photodiode (PD) 9 are mounted on the substrate inside the sensor unit 7, and the light emitted from the LED 8 irradiates the sheet M or the platen 3, and the reflected light is received by the photodiode 9. The sheet M or the platen 3 is detected.

  FIG. 3 is a block diagram showing a control configuration of the printing apparatus shown in FIG.

  As shown in FIG. 3, the LED 8 mounted on the sensor unit 7 is controlled by the LED control unit 10, and the photodiode (PD) 9 is controlled by the photodiode (PD) control unit 11. The end position correction value (described later) is stored in the storage unit 12 such as a DRAM.

  The transport roller 1 is driven by the transport motor 13, and the transport motor 13 is further controlled by the transport motor control unit 15. On the other hand, the carriage 4 is driven by a carriage motor 14 and further controlled by a carriage motor control unit 16. Then, the printer control unit 19 controls the printing apparatus to execute a printing operation.

  The display unit 17 is configured by an LED, an LCD, and the like, and displays settings of the printing apparatus, operation status, and the like to notify the user of the current apparatus state. The LED control unit 10 and the PD control unit 11 are included in the paper end sensor control unit 20, and the CPU 18 controls the printer control unit 19 and the paper end sensor control unit 20.

  In addition to the DRAM, the storage unit 12 includes a ROM that stores a control program and a nonvolatile memory such as an EEPROM that can retain the memory even when power supply to the apparatus is stopped.

  Next, several examples of correction of the detection result (detection position) of the end sensor using the sensor unit of the printing apparatus having the above configuration will be described.

  Here, a printing apparatus is provided that performs borderless printing by appropriately setting the end of a sheet (for example, cut paper or roll paper) that is a print medium based on the position detected by the sensor. Is made for the purpose. In this embodiment, the carriage position correction value to which the carriage speed and acceleration according to the carriage position contribute in the carriage movement is stored as a table, and print control is performed using this correction value. In particular, when acceleration is applied to the carriage, a moment is generated in the carriage due to a shift in the mass balance of the carriage, and the attitude of the end sensor changes, so that the carriage position is corrected according to the acceleration.

Correction Value Identification Flow FIG. 4 is a schematic diagram of a correction pattern to be printed on the sheet M when identifying the correction value of the detection position of the sensor unit 7, and FIG. 5 shows the correction value of the detection position of the sensor unit 7. It is a flowchart which shows the sequence to identify.

  The correction value identification flow of the printing apparatus will be described with reference to FIGS. The correction value identification flow is performed according to a user instruction before the printing apparatus is operated or when the print position is shifted.

  When the correction value identification flow is started, first, in step S100, a square correction pattern is printed on the sheet M with black ink as shown in FIG. 4 (pattern printing).

  Next, in step S101, the sensor unit 7 detects the (left end) boundary of the correction pattern by scanning the carriage 4 again in the arrow direction shown in FIG. Further, in step S102, it is checked whether the scan has been completed at all speeds used in the actual print mode. If it is determined that scanning at all speeds has not been completed, the process returns to step S101, the carriage 4 is returned to the original position, the scan speed is changed, and the carriage 4 is rescanned. On the other hand, if it is determined that scanning at all speeds has been completed, the process proceeds to step S103.

  In step S103, a correction value is calculated for each speed acquired in the processes in steps S101 to S102. When the carriage speed changes, the detection position of the boundary of the correction pattern by the sensor unit 7 is shifted according to the change. Therefore, a certain speed is set as a reference speed, a detection position obtained at the reference speed is set as a reference position, and a deviation from the reference position at each speed is calculated as a correction value. In addition, in the calculation, an average of detection positions obtained from all speeds may be used as a reference, or a detection position obtained from a speed selected by the user may be used as a reference. In any case, the deviation from the reference is used as the correction value.

In step S104, the sensor unit 7 detects the boundary of the correction pattern by scanning the carriage 4 in the arrow direction shown in FIG. Further, in step S105, it is checked whether the scan has been completed for all accelerations used in the actual print mode. For example, if the carriage moves with a speed profile shown in FIG. 8A described later, five different accelerations (A ₁ , A ₂ , 0, −A ₂ , −A ₁ ) are assumed.

  If it is determined that scanning with all accelerations is not completed, the process returns to step S104, the carriage 4 is returned to the original position, the scan acceleration is changed, and the carriage 4 is rescanned. On the other hand, if it is determined that scanning with all accelerations has been completed, the process proceeds to step S106.

  In step S106, a correction value for each acceleration is calculated for each acceleration acquired in the processes in steps S104 to S105. When the carriage acceleration changes, the detection position of the boundary of the correction pattern by the sensor unit 7 is shifted according to the change. Therefore, a certain acceleration is set as a reference acceleration, a detection position obtained with the reference acceleration is set as a reference position, and a deviation from the reference position at each acceleration is calculated as a correction value. In addition, in the calculation, an average of detection positions obtained from all accelerations may be used as a reference, or a detection position obtained from an acceleration selected by the user may be used as a reference. In any case, the deviation from the reference is used as the correction value.

  The speed correction value and the acceleration correction value calculated as described above are stored in the storage unit 12 in a table format.

Printing Operation FIG. 6 is a schematic view showing a state where the end of the sheet is detected while the carriage of the printing apparatus reciprocates and performs printing. 6A shows a state in which the end portion is detected while performing the forward pass printing, and FIG. 6B shows a state in which the end portion is detected while performing the return pass printing. In FIGS. 6A and 6B, shaded portions indicate portions that have already been printed by the print head 5, and the left end of the sheet M is a reference end for correction, and the right end is a non-reference. It becomes the end.

  FIG. 7 is a flowchart showing a sequence for detecting the edge of the sheet while printing.

  Next, the printing operation of the printing apparatus according to the first embodiment will be described with reference to FIGS.

  First, when a print command is transmitted to the printing apparatus, in step S200, the carriage 4 is scanned, and the position of the reference end and the position of the non-reference end are detected by the sensor unit 7.

  Next, in step S201, a print area is determined based on the end position detected in step S200, and printing in the forward direction (outward path printing) is executed. In the forward printing, in step S202, the position of the reference end is measured when the sensor unit 7 passes the reference end, and in step S203, the non-reference end of the non-reference end is measured when the sensor unit 7 passes the non-reference end. Measure the position.

  Further, after the forward printing is completed, the sheet M is conveyed by the conveying roller 1, and in step S204, a printing area is determined based on the end position detected in steps S202 to S203, and printing in the backward direction (return printing) is performed. Run.

  In step S205, it is checked whether all printing has been completed. If it is determined that printing has not been completed, the process returns to step S201, the print area is determined based on the edge position measured during the previous printing, and the above-described process is repeated. On the other hand, if it is determined that the printing is finished, the printing operation is finished.

Correction Value Application Method FIG. 8 is a diagram showing a carriage speed profile in the forward movement or backward movement of the carriage.

  8A shows a profile of the moving speed of the carriage 4 when the printing apparatus moves the carriage 4 to print a predetermined width. (B) is a table showing the approximate speed of the carriage 4 at each carriage position and the end position correction value of the speed component when the end is detected at that position. Further, (c) is a table showing the approximate acceleration of the carriage at each carriage position and the end position correction value of the acceleration component when the end is detected at that position.

  Here, a method of applying the correction value of the edge detection position of the printing apparatus according to the first embodiment will be described with reference to FIG.

  As shown in FIG. 8A, when the print width in the main scanning direction is determined, the speed profile of the carriage 4 is determined. When the approximate position of the end position is known by the sensor unit 7, it is detected in which region of the speed profile shown in FIG. When the region is detected, the speed correction value shown in FIG. 8B and the acceleration correction value shown in FIG. 8C corresponding to the region are added to correct the end position.

For example, if the end position (carriage position) detected by the sensor unit 7 is a ₁ , the speed correction value R _v1 is obtained with reference to the table of FIG. Similarly, the end position (carriage position) if a _1, the acceleration correction value R _A1 with reference to the table shown in FIG. 8 (c) is obtained. In this case, as seen with reference to FIG. 8 (a), the region of the carriage position a ₁ is therefore included in the area of the b _1, b ₁ is determined from the carriage position a _1.

  The correction value is calculated as follows.

If the total position correction value is R, the position correction value due to mechanical deviation is R _m , the correction value contributed by speed is R _V , and the correction value contributed by acceleration is R _A ,
_{R = R m + R V +} R A ...... (1)
It becomes.

As can be seen from FIGS. 8A and 8C, since the acceleration is “0” in the region where the carriage is moving at a constant speed (region where the carriage position is b ₃ ), the acceleration correction value is also “0” means no correction. On the other hand, at the end of the sheet (the carriage positions are b ₁ , b ₂ , b ₄ , and b ₅ ), the carriage accelerates and decelerates so that acceleration is applied. In this case, correction according to the acceleration is performed. In particular, when borderless printing is performed, the print area extends to the edge of the sheet (for example, the areas where the carriage positions are b ₂ and b ₄ ). Therefore, correcting the carriage position according to the acceleration of the carriage at the end of the print medium contributes to more accurately determining the print area of the borderless print.

  Therefore, according to the embodiment described above, the speed correction value and the acceleration correction value are obtained based on the carriage speed correction value, the acceleration correction value, and the carriage position which are calculated and stored in the table format. Since the correction is performed, the print area can be accurately determined.

  Here, an example will be described in which the carriage speed and acceleration are actually measured by a sensor, and a correction value is calculated from the actually measured values. In particular, in this embodiment, an example in which the contribution from each component of acceleration is considered will be described.

FIG. 9 is a schematic diagram showing the internal structure of the carriage 4 of the printing apparatus according to the second embodiment.

  As shown in FIG. 9, the carriage 4 includes a substrate 21 that controls the carriage 4, and an acceleration sensor 22 is mounted on the substrate 21. The acceleration sensor 22 can detect the acceleration of the carriage 4. Further, an encoder sensor 23 that detects a speed when the carriage 4 is driven is installed on a side surface of the carriage 4, and an encoder scale 24 is provided along the carriage rail 6 described in FIG. 1.

Correction Value Identification Flow FIG. 10 is a diagram for explaining the rotation of the carriage 4 according to the second embodiment. 10A is a diagram showing a shift of the end detection position due to the rotation of the carriage 4 in the pitch direction, and FIG. 10B is a diagram showing a shift of the end detection position due to the rotation of the carriage 4 in the yaw direction. Yes, (c) is a table showing acceleration correction values for each rotation direction. Here, the rotation in the pitch direction is rotation around the Y axis indicated by the dashed arrow in FIG. 10A, while the rotation in the yaw direction is the X axis and Y axis indicated by the broken arrow in FIG. 10B. And a rotation around the axis in the vertical direction. These rotations change the attitude of the sensor unit 7 with respect to the sheet M.

  Next, a sequence for identifying a correction value corresponding to the acceleration according to the acceleration of the printing apparatus according to the second embodiment will be described with reference to FIG.

As shown in FIG. 10A, when the carriage 4 decelerates while moving in the main scanning direction X indicated by the arrow, rotation in the pitch direction occurs. That is, due to the deceleration, a force acts in the left direction with respect to the carriage 4 and the sensor unit 7 in the X direction. Here, if the mass distribution of the carriage 4 and the sensor unit 7 is not uniform (usually not uniform), a moment acts around the Y axis and a rotational force in the pitch direction is generated. If the distance between the sheet M and the carriage 4 at that time is h and the acceleration of the carriage 4 is A, the acceleration correction value R _Ap uses an inclination coefficient m proportional to the carriage mass, and R _Ap = h × tan (A × m) ...... (2)
It becomes.

As shown in FIG. 10B, when the carriage 4 decelerates while moving in the main scanning direction X indicated by the arrow, rotation in the yaw direction also occurs. Similarly to the case shown in FIG. 10A, a force acts in the left direction with respect to the carriage 4 and the sensor unit 7 in the X direction by the deceleration. Here, if the mass distribution of the carriage 4 and the sensor unit 7 is not uniform (usually not uniform), a moment acts around an axis perpendicular to the X axis and the Y axis, and a rotational force in the pitch direction. Will occur. If the length of the carriage 4 in the main scanning direction X at that time is L, the acceleration correction value R _Ay is calculated using a slope coefficient m proportional to the carriage mass. R _Ay = L × {1−cos (A × m)} ...... (3)
It becomes. The sum of the correction values in the pitch direction and the yaw direction is a correction value _{RA for} the total acceleration, that is,
R _A = R _Ap + R _Ay (4)
It becomes.

Further, the speed correction value corresponding to the speed is generated by the influence of the electrical delay of the LED 8 and the photodiode 9 of the sensor unit 7, and when the delay time is T, the correction value (speed correction value) R _V to which the speed contributes is ,
R _V = V × T (5)
It becomes.

  FIG. 11 is a flowchart showing a detailed sequence for calculating a correction value for each acceleration in step S106 of FIG. 5, and FIG. 12 is a diagram showing correction values obtained when scanning is performed at a predetermined acceleration.

  Here, with reference to FIGS. 11 to 12, a correction value calculation process of the printing apparatus according to the second embodiment will be described.

  In the correction value identification flow, when processing for calculating a correction value for each acceleration in step S106 is entered, in step S300, the sensor unit 7 scans the carriage in the direction shown in FIG. Detect boundary of.

  Next, in step S301, it is checked whether or not scanning has been completed for all possible accelerations. If it is determined that scanning with all accelerations is not completed, the process returns to step S300, the carriage 4 is returned to the original position, the acceleration is changed, and the carriage 4 is rescanned. On the other hand, if it is determined that scanning with all accelerations has been completed, the process proceeds to step S302.

In step S302, the correction value for each acceleration is acquired as shown in FIG. 12, and the slope coefficient m is calculated by calculating back the equations (2) and (3) relating to R _Ap and R _Ay . In step S303, a correction value R _A corresponding to the acceleration obtained from the slope coefficient m is calculated.

Correction Value Application Method The speed when the carriage 4 is moved to pass the end portion of the sheet M and the end position is detected is detected by the encoder sensor 23 and the acceleration sensor 22 is detected by the acceleration sensor 22. Then, the speed correction value R _V corresponding to each is determined from the equation (5), and the acceleration correction value R _A is determined from the equations (2) to (4) to correct the end position. As in the first embodiment, if the position correction value due to mechanical deviation is R _m , the total position correction value R is calculated as R = R _m + R _V + R _A from the following relationship expressed by the equation (1).
Can be obtained as follows.

  Since other operations and configurations are the same as those of the first embodiment, description thereof is omitted.

  According to the embodiment described above, it is possible to detect the end portion of the sheet during the reciprocating movement of the carriage and calculate the correction amount by calculating the correction value of the velocity and each acceleration component from the position of the end portion. Become. In particular, in this embodiment, even if the attitude of the end sensor is tilted, acceleration correction values for the pitch direction and the yaw direction are obtained using the acceleration sensor, so that measurement errors due to changes in the sensor attitude can be corrected appropriately. It becomes possible.

  In the first embodiment, the example in which the end sensor detects the left end of the correction pattern has been described. Here, an example in which both the left end and the right end of the correction pattern are detected will be described.

Correction Value Identification Flow FIG. 13 is a diagram showing how the end sensor detects the correction pattern.

  13A shows a state in which the sensor unit 7 moves in the main scanning direction X and detects the right end of the correction pattern printed on the sheet M. FIG. (B) shows how the sensor unit 7 moves in the main scanning direction X and detects the left end of the correction pattern printed on the sheet M.

  FIG. 14 is a flowchart showing a sequence for identifying the correction value of the detection position of the sensor unit 7.

  Next, a correction value identification flow according to the third embodiment will be described with reference to FIGS.

  In the correction value identification flow, when processing for calculating a correction value for each acceleration in step S106 is entered, in step S400, the right end of the correction pattern is detected at a predetermined acceleration (acceleration) as shown in FIG. . In step S401, a reference end correction value (that is, the left side) is calculated.

  In step S402, the left end of the correction pattern is detected at a predetermined acceleration (deceleration) as shown in FIG. In step S403, a non-reference end correction value (that is, the right side) is calculated.

Correction Value Application Method FIG. 15 is a table showing acceleration end position correction values when a predetermined end is detected.

As shown in FIG. 15, the end position is corrected using the acceleration correction value as the R _{reference end at} the reference end and the R _{non-reference end at the non-reference end} .

  During forward printing, the carriage is accelerated at the reference end and decelerated at the non-reference end, and during return printing, the carriage is decelerated at the reference end and accelerated at the non-reference end. It is provided.

  The correction value is calculated as follows.

As in the first and second embodiments, assuming that the total position correction value is R, the position correction value due to mechanical deviation is R _m , the speed correction value is R _V , and the acceleration correction value is _RA ,
R = R _m + R _V + R _A
It becomes.

  Since other operations and configurations are the same as those of the first embodiment, description thereof is omitted.

  Therefore, in the embodiment described above, it is possible to appropriately correct the reference end portion and the non-reference end portion in each of the forward pass and the return pass of the reciprocating print, so that more accurate position detection is performed in the reciprocating print. It becomes possible.

  In any of the above-described embodiments, the print area for printing with the print head is determined based on the result of detecting the edge of the sheet by the sensor unit while moving the carriage. The sensor unit can also be used for other purposes, specifically for registration adjustment. Examples thereof will be described below.

  Here, the edge of the adjustment pattern printed by each nozzle row is detected by a sensor with a print head having a plurality of nozzle rows on the sheet, and the deviation for each nozzle row is calculated based on the detected position. An example in which printing is performed by correcting the ejection timing for each nozzle row will be described. In particular, the correction value of the end position corresponding to the position of the end of the pattern and the acceleration when the end sensor passes through the end is stored.

Head Configuration FIG. 16 is a schematic diagram showing the configuration of the print head 5 according to the fourth embodiment.

  As shown in FIG. 16, a plurality of nozzles 25 that eject ink of the same color are arranged in the sub-scanning direction Y on the print head 5 to form a nozzle row. In addition, nozzle rows that eject inks of different colors in the main scanning direction X are arranged as Line1, Line2, Line3,. Since the interval between the nozzle rows is set to a predetermined distance, when printing at the same position, the print positions can be overlapped by shifting the ink ejection timing by a predetermined distance.

  However, if there is an error in the spacing between the nozzle rows, the print position will be shifted. Therefore, an error in the spacing between the nozzle rows is calculated based on the reference nozzle row Line 1 in the registration adjustment described later, Correct the timing.

Registration Adjustment Execution Flow FIG. 17 is a schematic diagram showing a print head registration adjustment pattern and its reading method, and FIG. 18 is a flowchart showing a registration adjustment execution sequence. In FIG. 17, X and Y indicate the main scanning direction and the sub-scanning direction, respectively, and the small rectangular patches drawn on the sheet M are registration adjustment patterns (hereinafter referred to as adjustment patterns). These patches are printed by each of a plurality of nozzle rows. That is, the first row patch is the Line 1 nozzle row, the second row patch is the Line 2 nozzle row, the third row patch is the Line 3 nozzle row, and the fourth row patch is the Line 4 nozzle. Printed by the nozzle row.

  A registration adjustment execution flow according to the fourth embodiment will be described with reference to FIGS. 17 to 18. Registration adjustment is a calibration process for finely adjusting the ink discharge timing when printing is performed by the print head to form a correct image.

  When the registration adjustment is started, the adjustment pattern is printed as shown in FIG. 17 in step S501. At this time, the reference pattern is an adjustment pattern printed by the reference nozzle row Line1. In step S502, the end of each adjustment pattern is measured by scanning the sensor unit 7.

  In step S503, the difference in position in the main scanning direction X between the reference pattern Line1 and the adjustment pattern printed by each nozzle row is calculated. In step S504, an error in the interval between the nozzle rows is specified from the calculated position difference, and a discharge timing correction value for each nozzle row is determined.

  As described above, the adjustment pattern is formed in advance on the sheet by the print head. Then, based on the result of reading the adjustment pattern by the sensor unit while moving the carriage, registration adjustment when performing printing with the print head is performed. After correcting the ejection timing for each nozzle row using the ejection timing correction value determined by the registration adjustment performed as described above, the actual image is printed.

  According to the embodiment described above, even when printing is performed using a print head provided with a plurality of nozzle rows, high-quality printing can be performed with accurate correction.

  According to some embodiments described above, the position of the end of the sheet can be detected more accurately in the main scanning direction in which the carriage moves. Thereby, the position of the print area printed by the print head can also be accurately determined. In particular, even when performing printing such as borderless printing, it is possible to prevent the print area from protruding outside the sheet, and to realize high-quality borderless printing.

  In the above-described embodiments, a single-function printing apparatus has been described as an example, but the present invention is not limited thereto. For example, the printer described above may be a multi-function printer (copier) provided with an image reading device (scanner device), or may be a multi-function device in which a facsimile function is added to the copier.

4 Carriage, 5 Print head, 7 Sensor unit, 22 Acceleration sensor

Claims (12)

A carriage mounted with a print head and reciprocating;
A sensor unit that is mounted on the carriage and detects a pattern formed on an end of the sheet or on the sheet;
A printing apparatus comprising: correction means for correcting detection by the sensor unit when the carriage is accelerated or decelerated.   The printing apparatus according to claim 1, wherein the correction unit performs different corrections when the carriage is accelerated and decelerated.   The printing apparatus according to claim 1, wherein the correction unit does not perform correction when the carriage moves at a constant speed.   4. The printing apparatus according to claim 1, wherein the correction unit performs different corrections when the carriage moves in a reciprocating manner and when the carriage moves in a backward direction. 5.   5. The printing apparatus according to claim 1, wherein the correction unit performs correction using a profile for controlling movement of the carriage. 6. The carriage is equipped with an acceleration sensor,
The printing apparatus according to claim 1, wherein the correction unit corrects detection of the acceleration sensor when the carriage moves.   The printing apparatus according to claim 6, wherein the correction unit performs correction using the acceleration in the pitch direction and the acceleration in the yaw direction obtained by the acceleration sensor.   8. The apparatus according to claim 1, further comprising storage means for storing a correction value calculated by reading a correction pattern formed in advance on the sheet by the sensor unit while moving the carriage. The printing apparatus as described in.   9. The apparatus according to claim 1, further comprising control means for controlling the carriage and the print head based on the value corrected by the correction means to perform serial printing on the sheet. The printing apparatus according to item. A method of performing printing by reciprocating a carriage mounted with a print head and a sensor unit,
While moving the carriage, the sensor unit detects a pattern formed on the end of the sheet or on the sheet,
When the carriage is accelerated or decelerated, detection by the sensor unit is corrected.   The printing method according to claim 10, further comprising: determining a print area when printing is performed by the print head based on a result of detecting an end portion of a sheet by the sensor unit while moving the carriage.   Based on the result of reading the adjustment pattern by the sensor unit while forming the adjustment pattern on the sheet with the print head and moving the carriage, the registration adjustment when performing printing with the print head is performed. The printing method according to claim 10, wherein the printing is performed.

Images