JP2011104776A - Ink jet recording device and method of adjusting dot formation position for the device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To perform appropriate adjusting processing even when recording media with various thickness are used while suppressing consumption of the recording media and ink and shortening time required for the adjustment as much as possible, in an ink jet recording device capable of changing an interval between a recording head and the recording media and performing processing to adjust a dot formation position condition. <P>SOLUTION: The ink jet recording device includes a means for making the recording media record an adjustment pattern used to perform the adjusting processing and performing the adjusting processing in accordance with a distance between the recording head and the recording media based on the recorded adjustment pattern. Two different intervals are set with respect to the recording media, and discharge speed of ink from a discharge port is detected with respect to each of the two intervals. In accordance with determination of whether or not a difference of the discharge speeds detected with respect to the two intervals is within a specified range, the means records the adjustment pattern of either one or both of the two intervals and performs the adjusting processing based on the adjustment pattern. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a dot formation position adjusting method in dot matrix recording using an ink jet recording head and a recording apparatus using the method.

  As a recording apparatus that performs recording by forming dots on a recording medium, an ink ejection port array (ejection port) is moved in a predetermined direction relative to the recording medium, and in a direction different from that direction (for example, the recording medium conveyance direction). Some use a recording head provided with a plurality of ejection portions having a row. Such a recording head is detachably attached to the recording apparatus, or is assembled so as not to be removable.In the former case, due to a positional error that occurs at the time of attachment and in the latter case at the time of assembling, In some cases, the dot formation position between the discharge units may be shifted.

  For this reason, in order to prevent the occurrence of such a shift and maintain high-quality image recording, a technique for performing a process (hereinafter also referred to as a registration process) for adjusting the dot formation position between the ejection units is known. . In these processes, a plurality of patterns are formed on the recording medium while shifting the discharge timing between the discharge units (hereinafter, these patterns are referred to as adjustment patterns). Then, the user who viewed the adjustment pattern selects the optimum one and inputs the information, reads the adjustment pattern with an optical sensor, and calculates the adjustment value from the read value, thereby adjusting the recording device. It is common to set a value.

  On the other hand, there are various types of recording media used for recording an image in an inkjet recording apparatus, and there are various thicknesses. In ink jet recording, in which ink is ejected to a recording medium and recording is performed in a non-contact manner, the ink ejection speed, the movement speed of the recording head, and the distance between the recording head and the recording medium greatly affect the accuracy of the dot formation position. . Therefore, even if an adjustment value for registration processing is obtained for a recording medium having a certain thickness, the adjustment value may not be appropriate for a recording medium having a different thickness. For this reason, in Patent Document 1, the thickness of the recording medium set to perform image recording is detected, and the detected thickness is adjusted according to the amount of change with respect to the thickness of the recording medium from which the adjustment value is obtained. A technique for obtaining a correction value is disclosed. It is described that this configuration eliminates the need to perform processing (adjustment processing) for obtaining an adjustment value for registration each time the thickness of the recording medium changes.

  However, in recent years, the types or thicknesses of the recording media to be subjected to ink jet recording are further diversified. To cope with this, the height of the recording head or the interval between the recording head and the recording medium (head-medium interval). Some recording devices have a function to change the setting. In such a configuration, the head-medium interval changes more greatly, but the ink discharge state changes when the head-medium interval changes due to the influence of the surrounding environment (temperature / humidity environment) and the state of the recording head. There is a case. In order to cope with this, there is a possibility that the adjustment disclosed in Patent Document 1 may be insufficiently adjusted. Therefore, it is conceivable to perform adjustment processing for a plurality of head-medium intervals. However, since a large amount of adjustment patterns have to be recorded, the consumption of the recording medium and ink increases, and the time required for the adjustment process also increases.

Japanese Patent Laid-Open No. 06-143724

  Therefore, the present invention suppresses the consumption of the recording medium and the ink as much as possible, and shortens the time required for adjustment as much as possible, so that an appropriate registration process can be performed even when recording media of various thicknesses are used. The purpose is to do.

Therefore, the present invention provides an inkjet recording apparatus that forms dots by ejecting ink from a recording head having ejection openings and records an image on a recording medium.
An adjustment pattern used for performing an adjustment process for adjusting the dot formation position is recorded on the recording medium by the recording head, and based on the recorded adjustment pattern, the recording head, the recording medium, Adjustment processing means for performing the adjustment processing according to the distance, a changing means capable of changing an interval between the recording head and the recording medium, and an ejection speed detecting means for detecting an ink ejection speed from the ejection port; With
The adjustment processing unit causes the change unit to set at least two different intervals for the recording medium on which the adjustment pattern is recorded, and the discharge rate detection unit sets the discharge speed for each of the two intervals. Recording the adjustment pattern for one or both of the two intervals according to whether or not the difference between the ejection speeds detected for the two intervals is within a specified range. The adjustment process based on the adjustment pattern is performed.

The present invention also provides a dot formation position adjustment method for an ink jet recording apparatus that forms an image by ejecting ink from a recording head having an ejection port and records an image on a recording medium.
An adjustment pattern used for performing an adjustment process for adjusting the dot formation position is recorded on the recording medium by the recording head, and based on the recorded adjustment pattern, the recording head, the recording medium, An adjustment processing step for performing the adjustment processing according to the distance of
The adjustment processing step includes a step of setting at least two different intervals with respect to the recording medium on which the adjustment pattern is recorded, and a step of detecting an ink discharge speed from the discharge port for each of the two intervals. And the recording of the adjustment pattern for one or both of the two intervals and the determination of whether or not the difference between the discharge speeds detected for the two intervals is within a specified range. The adjustment processing based on the adjustment pattern is performed.

  According to the present invention, an ink discharge speed is detected in correspondence with the interval, and an adjustment pattern corresponding to one or both of which is necessary and sufficient to maintain the recording quality is recorded according to the comparison result. The As a result, the consumption amount of the recording medium and the ink is suppressed as much as possible, and the time required for the adjustment is shortened as much as possible, and an appropriate registration process is performed even when recording media having various thicknesses are used.

1 is a perspective view of an ink jet recording apparatus according to an embodiment of the present invention. FIG. 2 is a schematic perspective view showing a recording head applied to the apparatus of FIG. 1 from a direction in which ink is ejected. FIG. 2 is a block diagram illustrating a configuration example of a control system of the recording apparatus in FIG. 1. It is a conceptual diagram which shows the example of the adjustment pattern recorded according to adjustment pattern data. It is a flowchart which shows an example of the adjustment value acquisition process procedure implemented by the control system of FIG. 5A is a flowchart showing an example of an adjustment value acquisition processing procedure performed when it is determined in the procedure of FIG. 5 that the difference in discharge speed is within a specified range, and FIG. 5B is a linear expression obtained by the procedure. It is explanatory drawing which shows the example of. FIG. 5A is a flowchart illustrating an example of an adjustment value acquisition processing procedure performed when it is determined in the procedure of FIG. 5 that the difference in discharge speed is outside the specified range, and FIG. 5B is a linear expression obtained in the procedure. It is explanatory drawing which shows the example of. 6 is a flowchart illustrating an example of a recording processing procedure including correction value determination processing applied when image recording is actually performed by the apparatus according to the embodiment.

  Hereinafter, embodiments of an inkjet recording apparatus and a dot formation position adjusting method for the apparatus according to the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a perspective view of an ink jet recording apparatus according to an embodiment of the present invention. In this apparatus, a recording medium 9 is conveyed in the direction of arrow A by a conveyance roller 7 driven by a conveyance motor 2. In the middle of the conveyance path, a platen 1 that supports the recording medium 9 is provided to keep the recording surface of the recording medium 9 flat. Above the platen 1, two scanning rails (not shown) extend in parallel to the platen 1. In these scanning rails, a carriage 5 that reciprocates in the directions of arrows B and C (directions intersecting the direction of arrow A) by a carriage motor 3 and a belt 4 connected thereto is provided with a slide bearing (not shown). Is attached through.

  A linear scale 6 is disposed along the movement path of the carriage 5. The linear scale 6 is provided with regular slits for detecting the position of the carriage 5 and determining the ink discharge timing. Further, an optical linear scale sensor (not shown) is mounted on the carriage 5 in order to read the slit of the linear scale 6. The optical linear scale sensor counts pulses output by detecting the slit of the linear scale 6, thereby determining the position of the carriage 5 in the directions of arrows B and C. The pulse count is initialized by moving the carriage 5 to the position of a home position (HP) sensor (not shown) at the end of the scanning rail when the power is turned on. For example, a recording head having a number of ejection units corresponding to the ink color to be used is mounted on the carriage 5.

  FIG. 2 is a schematic perspective view showing the recording head mounted on the carriage 5 from the direction in which ink is ejected. The recording head 509 includes inks of different color tones (including color and density), such as black (Bk), light cyan (Lc), cyan (C), light magenta (Lm), magenta (M), and yellow (Y). Discharge portions 511 to 516 for discharging the inks are juxtaposed. Ink is supplied from the ink introduction unit 523 to each ejection unit via an ink flow path inside the recording head. In the illustrated example, each discharge unit has an array of two discharge ports (discharge port array). In addition, an element (electrothermal conversion element) that generates thermal energy that causes film boiling in the ink in response to energization, for example, is provided as energy used for ejecting the ink inside each ejection port.

  Referring again to FIG. 1, a reflective optical sensor 10 is mounted on the carriage 5. This sensor projects light from a light emitting unit toward a recording medium and receives the reflected light by a light receiving unit having a light receiving element. Based on the amount of received light, the end of the recording medium can be detected, the interval between the ejection port forming surface of the recording head and the recording medium (head-medium interval) can be detected, and the adjustment pattern can be read.

  An ink discharge speed detection sensor 8 is provided near one end of the carriage 5 movement range (near the right end in the illustrated example). The sensor 8 may be of any form as long as it can preferably detect the speed of ink ejected from the ejection port. For example, a receiving unit that receives ejected ink, a light emitting unit that projects light in a direction intersecting the path of the ejected ink, and a light receiving unit that opposes the light receiving unit. By detecting ink droplets passing between them, the speed can be detected.

  Further, although not shown in FIG. 1, in order to adjust the head-medium distance, an elevating mechanism for elevating the carriage 5 to change and set the height from the platen 1, for example, is provided. Such a lifting mechanism may be of any form as long as the height of the carriage 5 and thus the head-medium distance can be adjusted. For example, a cam that engages with a scanning rail that supports and guides the carriage 5 and can be rotated to adjust the height of the scanning rail or the carriage 5 in two levels, and an operating mechanism for causing the cam to rotate. It can have. The operating mechanism for rotating the cam may have an operation lever that is connected to the cam and receives an operation by the user. Alternatively, a motor that is driven in accordance with an instruction from a control unit (CPU), which will be described later with reference to FIG. 3, and a transmission mechanism that transmits the driving force to the cam according to the type of recording medium that is instructed to be used for recording. It can also have.

  As a recording medium applicable to the recording apparatus of FIG. 1, a cut sheet type or a continuous paper type can be used. In consideration of the use of roll paper, the recording apparatus of FIG. 1 is equipped with a cutter (not shown) for cutting the recorded portion by moving on the platen in the direction of arrow C. ing.

  FIG. 3 is a block diagram illustrating a configuration example of a control system of the recording apparatus of FIG. The overall control of the apparatus is executed by the CPU 20 based on a control program (such as a program corresponding to a processing procedure described later) stored in the ROM 12 and required fixed data. The RAM 13 provides a storage area for storing data (various parameters and tables) and a work area for the CPU 20. The internal pattern generation unit 11 stores or generates data for recording an adjustment pattern used for performing the registration process. Based on the output of the light receiving element when the reflective optical sensor 10 reads the adjustment pattern on the recording medium, the sensor control unit 14 detects a portion where the density of the adjustment pattern changes. As described above, the sensor 8 is also used for detecting the head-medium spacing and for detecting the edge of the recording medium on the platen 1.

  The CPU 20 calculates various adjustment values for registration based on the detection result of the sensor control unit 14 and stores them in a storage area such as a RAM 13 or a nonvolatile memory (not shown) such as an EEPROM. Further, the CPU 20 switches data for forming an adjustment pattern to be used for the registration process based on the output of the discharge speed detection unit 16 connected to the discharge speed detection sensor 8. Further, when recording an image, the CPU 20 refers to the adjustment value stored in the RAM 13 and the head-medium interval detected by the sensor 10 via the discharge control circuit 19, and between the discharge sections or the discharge port array. The ink ejection timing is controlled so that the dot formation positions coincide with each other.

  FIG. 4 is a conceptual diagram illustrating an example of an adjustment pattern recorded in accordance with the adjustment pattern data generated by the internal pattern generation unit 11. This adjustment pattern includes six types of adjustment patterns, and the adjustment pattern portion 21 recorded with the height of the carriage 5 or the recording head 509 set at a high position (High position) and the adjustment pattern portion 21 at a low position (Low position). The adjustment pattern unit 22 is set and recorded.

  The adjustment pattern shown in FIG. 4 is merely an example. The adjustment pattern can include, for example, a pattern that is subjected to a registration process for adjusting the dot formation position of each color ink discharge port array between forward movement and backward movement during bidirectional printing. . In addition, when a plurality of (two rows in FIG. 2) ejection port arrays are provided for each color ejection unit as shown in FIG. 2, an adjustment pattern for performing registration processing on the relationship between these ejection port arrays Can be included. Further, it is possible to include an adjustment pattern for performing a registration process on the relationship between the ejection portions or ejection port arrays of different color inks. In addition, each adjustment pattern is recorded while the ejection timing is relatively shifted in the relationship between the ejection port arrays to be adjusted, and the density when the dot formation positions are the best matches (or becomes the highest). ) Can be formed.

  As described above, there is a recording apparatus in which the height of the recording head can be adjusted in a plurality of stages corresponding to the thickness of the recording medium to be used. In this embodiment, two-stage adjustment of the high position and the low position is performed. It is possible. Here, the recording head 509 is set to one of the heights to record the adjustment pattern, the adjustment value is obtained based on the read value, and the adjustment value is set according to the other height from the height ratio. It is possible to correct. However, the ink discharge state may vary depending on the height of the recording head due to the influence of environmental conditions such as temperature and humidity and the state of the recording head. Then, when an image set to the other height is recorded based on the correction value of the adjustment value corresponding to one height, image quality such as density unevenness may be deteriorated. Therefore, as shown in FIG. 4, it can be said that it is desirable to record a plurality of adjustment patterns corresponding to the heights of the plurality of recording heads and acquire adjustment values for each. However, the amount of consumption of the recording medium and the ink increases correspondingly, and time is required.

  Therefore, in the present embodiment, these problems are solved by switching the adjustment process according to the ejection state of the recording head 509, in particular, the ink ejection speed that affects the change in the dot formation position. Specifically, when the registration process is activated, the ink ejection speed is detected at both the High position and the Low position before recording the adjustment pattern. Then, these discharge speeds are compared, and it is determined whether or not these differences are within a specified range.

  Here, even if the heights of the recording heads are different, if the ink ejection speed is constant, an adjustment value corresponding to the other height is calculated from the adjustment value corresponding to one of the heights. It is known that there are few errors. Therefore, if the comparison result of the ejection speed is within the specified range, the recording head 509 is set to one of the Low position and the High position to record the adjustment pattern, and the adjustment value is obtained based on this. At the time of image recording, the distance (distance) between the recording medium actually used for the image recording and the ejection port forming surface of the recording head 509 is expressed by a linear expression obtained from one adjustment value and the theoretical origin value. Is substituted to adjust the discharge timing.

  On the other hand, if there is a large variation in the ejection speed depending on the height of the recording head, the adjustment value during actual image recording using a linear expression obtained from the adjustment value corresponding to either the height or the height There is a possibility that the error becomes large when calculating. Therefore, when the comparison result of the discharge speed is outside the specified range, the adjustment pattern is recorded or the adjustment value is acquired at both the Low position and the High position, and linear interpolation is performed from these two adjustment values. Determine the primary equation to use.

This embodiment will be described more specifically.
FIG. 5 shows an example of the adjustment value acquisition processing procedure of this embodiment. This procedure may be started based on a user instruction when a timing for performing an adjustment occurs. The user's instruction can be given via, for example, a setting screen of a printer driver or the like that is connected to the recording apparatus of the present embodiment and operates on an external apparatus such as a computer that supplies image data to be recorded. Alternatively, it can be activated from an operation panel provided in the recording apparatus.

  When this procedure is started, first, the recording head 509 is set to the Low position and set to a position corresponding to the ejection speed detection sensor 8, and each color ink is appropriately ejected to detect the ink ejection speed (VL) of each color. (Step S11). Next, the recording head 509 is set to the high position, and the ink ejection speed (VH) is detected in the same manner (step S12). Note that the processing of these steps S11 and S12 may be reversed.

  Next, the difference between these two discharge velocities VL and VH is calculated, and it is determined whether or not it is within the specified range (step S13). As a result, if it is determined that it is within the specified range, an adjustment pattern is recorded corresponding to only one of the high and low positions, and an adjustment value is acquired (step S14). At this time, if the adjustment pattern is recorded corresponding to the high position, it is advantageous because it is not necessary to change the height of the recording head. If it is determined that it is out of the specified standard range, the adjustment pattern is recorded corresponding to both the high position and the low position, and the respective adjustment values are acquired (step S15). Further, a linear linear expression is determined based on the adjustment value acquired in step S14 or S15, and the slope A and constant B of the linear interpolation linear expression are stored in a storage area such as the RAM 13 or the EEPROM (step S16). .

  FIG. 6A is a flowchart illustrating details of the adjustment value acquisition process (step S14) corresponding to only the high position, which is performed when it is determined that the difference in discharge speed is within the specified range. Here, first, the sensor 10 is used to measure the actual gap (GapH) between the ejection port forming surface of the recording head at the High position and the recording medium used for recording the adjustment pattern (S101). Next, the adjustment pattern portion 21 corresponding to the High position is recorded (S102), and the pattern is read by the sensor 10 (S103). Then, an adjustment value (ValueH) is calculated from the read result (S104), and a linear linear expression is determined from the adjustment value (ValueH) and the theoretical origin (S105).

  FIG. 6B shows an example of the linear expression obtained above. Here, the horizontal axis represents the distance between the head and the medium, and the vertical axis represents the correction value of the adjustment value. A straight line having a slope A (constant B = 0) connecting the point (GapH, ValueH) and the origin. It has become. In this case, the ink discharge speed is constant regardless of the height of the recording head. Therefore, regardless of the height of the recording head, the correction value ValueP is obtained by substituting the actual head-medium distance, that is, the distance (GapP) into this linear expression, and the ejection timing is adjusted appropriately. be able to.

  FIG. 7A is a flowchart showing details of the adjustment value acquisition process (step S15) corresponding to the high position and the low position, which is performed when it is determined that the difference in discharge speed is outside the specified range. Here, first, Steps S201 to S204 similar to Steps S101 to S104 in FIG. 6A are executed, and an adjustment value (ValueH) corresponding to the High position is acquired. Next, the height of the recording head is changed to the Low position, and the head-medium interval (GapL) is measured (step S205). Then, the adjustment pattern portion 22 corresponding to the Low position is recorded as it is (step S206), the pattern is read by the sensor 10 (step S207), and an adjustment value (ValueL) is calculated from the read result (step S208). Further, a linear expression is determined from these two adjustment values ValueH and ValueL (step S209).

  FIG. 7B shows an example of the linear expression obtained as described above, and is a straight line having a slope A and a constant B connecting a point of (GapH, ValueH) and a point of (GapL, ValueL). . In this case, the ink ejection speed differs depending on the height of the recording head, and the correction value ValueP is obtained by substituting the actual head-medium spacing (GapP) into this linear expression, and the ejection timing is adjusted appropriately. can do.

FIG. 8 is a flowchart illustrating an example of a recording processing procedure including correction value determination processing applied when actually recording an image. When the start of recording is instructed, the sensor 10 measures the gap GapP between the recording medium actually used for image recording and the ejection port forming surface of the recording head (step S31). Then, as shown in FIG. 6 (a) or FIG. 6 (b), the measurement result GapP is substituted into the linear expression of the stored slope A and constant B, that is, ValueP = GapP × A + B.
The correction value ValueP is calculated based on the equation (S32). Then, using this correction value ValueP, ink ejection timing at the time of image recording on the recording medium is controlled (step S33).

  As described above, in the present embodiment, the ink ejection speed is detected in correspondence with the height of the recording head in two steps, high and low, and depending on the comparison result, it is necessary and sufficient to maintain the recording quality. An adjustment pattern portion corresponding to one or both is recorded. For this reason, when it is determined that the ejection speed is substantially constant regardless of the height of the recording head, it is sufficient to record only the adjustment pattern portion corresponding to one of the recording head and the recording medium. Waste can be prevented. In addition, although ink is consumed to detect the ejection speed, this amount is smaller than that in the case of recording two adjustment pattern portions corresponding to the height of the recording head in two steps, high and low. Therefore, it is possible to suppress the ink consumption.

  In addition, the detected value of the head-medium distance for the recording medium used for recording of the adjustment pattern portion is applied to the ejection speed obtained corresponding to the recording head height in two steps, high and low, to actually record the image. A linear expression for performing correction according to the thickness of the recording medium used is obtained. Here, on the premise that the height of the recording head is not adjusted, or on the premise of a recording apparatus in which such an adjustment cannot be made, two types of thickness recording media are prepared for obtaining adjustment values, and the heads for each It is also conceivable to detect the distance between the media and the discharge speed. However, taking into account the decrease in accuracy due to the time required for replacing the recording medium and the fact that the distance between the two points for obtaining the linear expression as shown in FIG. In addition, it is advantageous to perform adjustment processing by changing the height of the recording head for the same recording medium.

  In the above embodiment, the example in which the adjustment process is performed on the two points of the high position and the low position has been described. However, if the comparison results of the discharge speeds are significantly different, adjustment processing corresponding to three points (for example, the middle position between them in addition to the low position and the high position) can be performed. At the time of actual image recording, according to the head-medium distance depending on the recording medium used, a linear expression obtained for two points of the Low position and the Middle position, or two points of the Middle position and the High position were obtained. A correction value may be obtained by selecting a linear expression.

  Further, the specified range or threshold value used for comparing the ejection speeds may not be fixed for all ink colors, but may be changed according to the color, the characteristics of the recording apparatus, the recorded image, or the like. For example, when graphic printing is performed, the above-mentioned light magenta and light cyan, light gray, and gray, which are light colors, are considered not to have a large effect on the image, so the specified range is widened compared to other primary colors. be able to. On the other hand, when a CAD drawing is printed, the fine line is also important, so that it is possible to define a specified range for gray equivalent to that for black. Furthermore, in consideration of these, for example, the setting of the image type or the specified range is set via a setting screen of a printer driver or the like that operates on a computer that is an image data supply source, or via an operation panel provided in the recording apparatus. You can also do it.

  Furthermore, it is needless to say that the configuration and number of the above-described ejection units or recording heads, and the type and number of ink color tones are merely examples, and appropriate ones can be employed. Also, the number of ejection port arrays provided in one ejection unit can be determined as appropriate. Further, in the above example, the recording medium is in the form of continuous paper, but the present invention is also effective when using a cut sheet.

1 Platen 5 Carriage 8 Discharge speed detection sensor 9 Recording medium (roll paper)
10 reflective optical sensor 11 internal pattern generation unit 20 CPU
21 and 22 Adjustment pattern portion 509 Recording head 511 to 516 Discharge portion

Claims (3)

In an inkjet recording apparatus for recording an image on a recording medium by forming dots by ejecting ink from a recording head having an ejection port,
An adjustment pattern used for performing an adjustment process for adjusting the dot formation position is recorded on the recording medium by the recording head, and based on the recorded adjustment pattern, the recording head, the recording medium, Adjustment processing means for performing the adjustment processing according to the distance of,
Changing means for changing an interval between the recording head and the recording medium;
A discharge speed detecting means for detecting a discharge speed of ink from the discharge port;
With
The adjustment processing unit causes the change unit to set at least two different intervals for the recording medium on which the adjustment pattern is recorded, and the discharge rate detection unit sets the discharge speed for each of the two intervals. Recording the adjustment pattern for one or both of the two intervals according to whether or not the difference between the ejection speeds detected for the two intervals is within a specified range. An inkjet recording apparatus that performs the adjustment process based on the adjustment pattern.   2. The ink jet recording apparatus according to claim 1, wherein the adjustment processing unit can change a size of the specified range used for the adjustment processing unit. In a dot formation position adjusting method for an ink jet recording apparatus that forms dots by discharging ink from a recording head having an ejection port and records an image on a recording medium.
An adjustment pattern used for performing an adjustment process for adjusting the dot formation position is recorded on the recording medium by the recording head, and based on the recorded adjustment pattern, the recording head, the recording medium, An adjustment processing step for performing the adjustment processing according to the distance of
The adjustment processing step includes a step of setting at least two different intervals with respect to the recording medium on which the adjustment pattern is recorded, and a step of detecting an ink discharge speed from the discharge port for each of the two intervals. And the recording of the adjustment pattern for one or both of the two intervals and the determination of whether or not the difference between the discharge speeds detected for the two intervals is within a specified range. A dot formation position adjustment method, wherein the adjustment process is performed based on an adjustment pattern.

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