JP2011056873A - Recorder, control method, and program - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a recorder which permits a drift in printing to accurately be sensed. <P>SOLUTION: The recorder records adjustment patterns (101 and 102) comprising a forward adjustment pattern (101) printed during a forward movement and a backward adjustment pattern (102) printed during a backward movement on a recording medium (16) (S1 to S9). Sensing the adjustment patterns (101 and 102), the recorder outputs a sensing signal corresponding to the adjustment patterns (101 and 102) (S10 to S14). Subsequently, the recorder analyzes the sensing signal and obtains two-dimensional frequency characteristics of the sensing signal (S17). Subsequently, on the basis of the two-dimensional frequency characteristics, the recorder detects a drift between dots printed in the main scanning direction and a drift between dots printed in the subsidiary scanning direction (S18). <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a recording apparatus such as an ink jet printer.

  An ink jet recording apparatus ejects ink from a recording head during reciprocation in the main scanning direction, attaches ink onto the recording medium, and records an image (dot) on the recording medium. Then, the recording medium is conveyed in the sub-scanning direction using a conveyance roller or the like, and recording in the main scanning direction is repeated to form an image on the recording medium.

  However, if an image (dot) is recorded on the recording medium during the reciprocating movement in the main scanning direction, the image (dot) recorded during the forward movement is deviated from the image (dot) recorded during the backward movement ( Misalignment of printing) is likely to occur.

  For this reason, conventionally, the ink ejection timing during the forward movement and the backward movement is adjusted to eliminate the above-described printing positional deviation. The adjustment of the ink ejection timing is performed using a predetermined adjustment pattern.

  For example, as a technical document filed prior to the present invention, Patent Document 1 superimposes the return path pattern on the forward path pattern with reference to the forward path pattern. The forward path pattern is a reference adjustment pattern formed during the forward movement, and the backward path pattern is an adjustment pattern for adjustment formed during the backward movement. Next, the superimposed adjustment pattern is detected, and the user determines the optimum adjustment pattern by visual observation from the change in density and color of the detected adjustment pattern, and uses the determined adjustment pattern. The printing position deviation is adjusted.

  However, the visual determination requires extra work for the user. Further, since the method for determining the adjustment pattern for adjustment is different for each user, it is not possible to accurately detect a print position shift.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a recording apparatus, a control method, and a program capable of accurately detecting a printing positional deviation.

  In order to achieve this object, the present invention has the following features.

<Recording device>
The recording apparatus according to the present invention includes:
A carriage equipped with a recording head provided with a plurality of nozzle arrays in the sub-scanning direction in which a plurality of nozzles that eject ink is arranged in the main scanning direction is reciprocated in the main scanning direction. A recording device for recording an image on
A forward adjustment pattern in which dots printed on the recording medium from a plurality of nozzle rows are arranged at regular intervals in the sub-scanning direction, and is printed at regular intervals in the main scanning direction during forward movement,
A return path adjustment pattern in which dots printed on the recording medium from the nozzle row are arranged at regular intervals in the sub-scanning direction is printed when the forward path is moved with reference to the center position of the print interval in the main scanning direction of the forward path adjustment pattern. ,
Recording means for recording an adjustment pattern composed of the forward path adjustment pattern and the return path adjustment pattern on the recording medium;
A two-dimensional sensor that detects the adjustment pattern and outputs a detection signal according to the adjustment pattern;
Analyzing means for analyzing the detection signal and obtaining a two-dimensional frequency characteristic of the detection signal;
Based on the two-dimensional frequency characteristics, detection means for detecting a positional deviation between the dots printed in the main scanning direction and a positional deviation between the dots printed in the sub-scanning direction;
It is characterized by having.

<Control method>
The control method according to the present invention includes:
A carriage equipped with a recording head provided with a plurality of nozzle arrays in the sub-scanning direction in which a plurality of nozzles that eject ink is arranged in the main scanning direction is reciprocated in the main scanning direction. A control method performed by a recording apparatus for recording an image on
A forward adjustment pattern in which dots printed on the recording medium from a plurality of nozzle rows are arranged at regular intervals in the sub-scanning direction, and is printed at regular intervals in the main scanning direction during forward movement,
A return path adjustment pattern in which dots printed on the recording medium from the nozzle row are arranged at regular intervals in the sub-scanning direction is printed when the forward path is moved with reference to the center position of the print interval in the main scanning direction of the forward path adjustment pattern. ,
A recording step of recording an adjustment pattern composed of the forward path adjustment pattern and the return path adjustment pattern on the recording medium;
An output step of detecting the adjustment pattern and outputting a detection signal corresponding to the adjustment pattern;
Analyzing the detection signal and obtaining a two-dimensional frequency characteristic of the detection signal;
Based on the two-dimensional frequency characteristics, a detection step of detecting a positional deviation between the dots printed in the main scanning direction and a positional deviation between the dots printed in the sub-scanning direction;
It is characterized by having.

<Program>
The program according to the present invention is:
A carriage equipped with a recording head provided with a plurality of nozzle arrays in the sub-scanning direction in which a plurality of nozzles that eject ink is arranged in the main scanning direction is reciprocated in the main scanning direction. A program to be executed by a recording apparatus for recording an image on
A forward adjustment pattern in which dots printed on the recording medium from a plurality of nozzle rows are arranged at regular intervals in the sub-scanning direction, and is printed at regular intervals in the main scanning direction during forward movement,
A return path adjustment pattern in which dots printed on the recording medium from the nozzle row are arranged at regular intervals in the sub-scanning direction is printed when the forward path is moved with reference to the center position of the print interval in the main scanning direction of the forward path adjustment pattern. ,
A recording process for recording an adjustment pattern composed of the forward path adjustment pattern and the return path adjustment pattern on the recording medium;
An output process for detecting the adjustment pattern and outputting a detection signal corresponding to the adjustment pattern;
Analyzing the detection signal and obtaining a two-dimensional frequency characteristic of the detection signal;
Based on the two-dimensional frequency characteristics, a detection process for detecting a positional deviation between the dots printed in the main scanning direction and a positional deviation between the dots printed in the sub-scanning direction;
Is executed by a computer.

  According to the present invention, it is possible to accurately detect a printing misalignment.

FIG. 2 is a diagram illustrating a schematic configuration example of a mechanism unit of a recording apparatus according to an embodiment. 1 is a first diagram illustrating a schematic configuration example of a printing mechanism of a recording apparatus according to an embodiment. It is a 2nd figure which shows the schematic structural example of the printing mechanism of the recording device of this embodiment. 3 is a diagram illustrating a configuration example of a recording head 6. FIG. 2 is a diagram illustrating a configuration example of a two-dimensional sensor 30. FIG. It is a figure which shows the structural example of the control mechanism of the recording device of this embodiment. 5 is a diagram illustrating a configuration example of adjustment patterns 101 and 102. FIG. It is a 1st figure for demonstrating the reference frequency (H1) of a main scanning direction. It is a 2nd figure for demonstrating the reference frequency (H1) of the main scanning direction. FIG. 6 is a first diagram for explaining frequency components (A1, B1) in the main scanning direction when a positional deviation occurs. FIG. 6 is a second diagram for explaining frequency components (A1, B1) in the main scanning direction when a positional deviation occurs. It is a figure for demonstrating a reference frequency. It is a 1st figure for demonstrating the reference frequency (H2) of a subscanning direction. It is a 2nd figure for demonstrating the reference frequency (H2) of a subscanning direction. FIG. 6 is a first diagram for explaining frequency components (A2, B2) in the sub-scanning direction when a positional deviation occurs. It is a 2nd figure for demonstrating the frequency component (A2, B2) of the subscanning direction at the time of position shift generation | occurrence | production. FIG. 6 is a first diagram for explaining frequency components (A1, B1, A2, B2) in the main scanning and sub-scanning directions when a positional deviation occurs. FIG. 6 is a second diagram for explaining frequency components (A1, B1, A2, B2) in the sub-scanning direction when a positional deviation occurs. It is a figure which shows the processing operation example of the recording device of this embodiment. It is a figure for demonstrating 2nd Embodiment. 3 is a diagram illustrating an example of arrangement of two-dimensional sensors 30. FIG.

(Outline of the recording apparatus of the present embodiment)
First, the outline of the recording apparatus of the present embodiment will be described with reference to FIGS. 4, 7, and 19.

  As shown in FIG. 4, the recording apparatus according to the present embodiment includes a carriage 5 on which a recording head 6 having a plurality of nozzle rows arranged in the main scanning direction, in which a plurality of nozzles for ejecting ink are arranged in the sub scanning direction. This is a recording apparatus that reciprocates in the main scanning direction and records an image on the recording medium 16 when the carriage 5 reciprocates.

  The recording apparatus of the present embodiment prints the forward adjustment pattern 101 in which dots printed on the recording medium 16 from a plurality of nozzle rows are arranged at regular intervals in the sub-scanning direction, and is printed at regular intervals in the main scanning direction during forward movement. Further, the return path adjustment pattern 102 in which dots printed on the recording medium 16 from a plurality of nozzle rows are arranged at regular intervals in the sub-scanning direction is determined based on the center position of the print interval in the main scanning direction of the forward path adjustment pattern 101. Printing is performed at the time of movement, and as shown in FIG. 7, adjustment patterns 101 and 102 composed of the forward adjustment pattern 101 and the return adjustment pattern 102 are recorded on the recording medium 16 (S1 to S9 in FIG. 19).

  Next, the adjustment patterns 101 and 102 are detected, and detection signals corresponding to the adjustment patterns 101 and 102 are output (S10 to S14 in FIG. 19).

  Next, the detection signal is analyzed, and a two-dimensional frequency characteristic of the detection signal is acquired (S17 in FIG. 19).

  Next, based on the two-dimensional frequency characteristics, a positional deviation between dots printed in the main scanning direction and a positional deviation between dots printed in the sub-scanning direction are detected (S18 in FIG. 19).

  Thereby, the recording apparatus of the present embodiment can accurately detect the positional deviation of printing. Hereinafter, the recording apparatus of the present embodiment will be described in detail with reference to the accompanying drawings.

(First embodiment)
<Example of schematic configuration of mechanism of recording apparatus>
First, a schematic configuration example of a mechanism unit of the recording apparatus according to the present embodiment will be described with reference to FIG.

  In the recording apparatus of the present embodiment, the main support guide rod 3 and the sub support guide rod 4 are horizontally mounted between the side plates 1 and 2 on both sides in a substantially horizontal positional relationship, and the main support guide rod 3 and the sub support guide rod 4 The carriage 5 is configured to be slidably supported in the main scanning direction.

  The carriage 5 has four recording heads 6 that discharge yellow (Y) ink, magenta (M) ink, cyan (C) ink, and black (Bk) ink, with their discharge surfaces (nozzle surfaces) facing downward. It is installed. The carriage 5 has four ink cartridges 7 (symbol “7” indicates any of the ink cartridges) above the recording head 6 (symbol “6” means any of the recording heads or a generic name). Or a generic name). The ink cartridge 7 is an ink supply body for each color for supplying ink to the four recording heads 6. The carriage 5 is connected to a timing belt 11 stretched between a driving pulley (drive timing pulley) 9 and a driven pulley (idler pulley) 10 that are rotated by the main scanning motor 8, and drives and controls the main scanning motor 8. By doing so, it is configured to move in the main scanning direction. The movement in the main scanning direction is controlled based on an encoder value obtained by providing an encoder sensor 41 on the carriage 5 and detecting the mark on the encoder sheet 40 by the encoder sensor 41.

  Further, the recording apparatus of the present embodiment is configured such that the subframes 13 and 14 are erected on the bottom plate 12 that connects the side plates 1 and 2, and the transport roller 15 is rotatably held between the subframes 13 and 14. ing. A sub-scanning motor 17 is disposed on the sub-frame 14 side, and in order to transmit the rotation of the sub-scanning motor 17 to the conveying roller 15, a gear 18 fixed to the rotation shaft of the sub-scanning motor 17 and the conveying roller 15 And a gear 19 fixed to the shaft.

  Further, between the side plate 1 and the subframe 12, a reliability maintaining and recovering mechanism (hereinafter referred to as “subsystem”) 21 of the recording head 6 is disposed. The sub-system 21 is configured by holding four cap means 22 for capping the ejection surface of the recording head 6 by a holder 23 and holding the holder 23 by a link member 24 so as to be swingable. Then, when the carriage 5 moves in the main scanning direction and the carriage 5 comes into contact with the engaging portion 25 provided in the holder 23, the holder 23 lifts up, and the cap means 22 caps the ejection surface of the recording head 6. Like to do. Further, when the carriage 5 moves to the print area side, the holder 23 is lifted down so that the cap means 22 is separated from the ejection surface of the recording head 6.

  The cap means 22 is connected to the suction pump 27 via the suction tube 26, forms an atmosphere opening port, and communicates with the atmosphere via the atmosphere opening tube and the atmosphere opening valve. The suction pump 27 discharges the sucked waste liquid (waste ink) to a waste liquid storage tank.

  A wiper blade 30 for wiping the discharge surface of the recording head 6 is attached to the blade arm 31 at the side of the holder 23. The blade arm 31 is pivotally supported and rotated by a driving means (not shown). The cam is swung by the rotation of the cam.

<Configuration example of printing mechanism of recording apparatus>
Next, a configuration example of the printing mechanism of the recording apparatus according to the present embodiment will be described with reference to FIGS.

  As shown in FIGS. 2 and 3, the printing mechanism of the recording apparatus of the present embodiment includes a carriage 5, a main support guide rod 3, and an encoder sheet 40. The carriage 5 includes a recording head 6, a two-dimensional sensor 30, and an encoder sensor 41.

  As shown in FIG. 4, the recording head 6 includes a plurality of nozzle rows in the main scanning direction (eight in this embodiment). Each nozzle row has a plurality of nozzles arranged in the sub-scanning direction. The printing mechanism of the present embodiment moves the carriage 5 on which the recording head 6 shown in FIG. 4 is mounted in the main scanning direction, and applies the recording medium 16 from a plurality of nozzle rows mounted on the recording head 6 in accordance with a predetermined printing timing signal. Ink is ejected to print an image (dot) on the recording medium 16.

  As shown in FIG. 4, the recording head 6 of the present embodiment is configured to print the same color in the sub-scanning direction using different nozzle rows one dot at a time. For example, in the case of black (k), the first dot from the top prints an image (dot) with the right nozzle row in the sub-scanning direction, and the next second dot has an image (dot) printed with the left nozzle row. Is printed in the sub-scanning direction. Thereby, it is possible to print a higher density image (dot) than printing an image (dot) with one nozzle row. In the case of the configuration shown in FIG. 4, the nozzle density (nozzle interval) of each nozzle row is 150 dpi, but since the same color is printed by different nozzle rows one dot at a time, the image density is low. A 300 dpi image (dot) can be printed.

  When printing is performed in both directions when the carriage 5 is reciprocated, misalignment between dots printed in the main scanning direction during forward movement and backward movement occurs as printing misalignment in the main scanning direction. Will do. Further, as shown in FIG. 4, the recording apparatus of the present embodiment is configured to print the same color in the sub-scanning direction with different nozzle rows one dot at a time. This occurs as a printing misalignment in the sub-scanning direction.

  For this reason, the recording apparatus of the present embodiment forms on the recording medium 16 adjustment patterns 101 and 102 constituted by the forward path adjustment pattern 101 printed during the forward movement and the backward path adjustment pattern 102 printed during the backward movement. A method for forming the adjustment patterns 101 and 102 will be described later. Next, the adjustment patterns 101 and 102 formed on the recording medium 16 are detected by the two-dimensional sensor 30, and a detection signal is acquired. Then, frequency analysis such as two-dimensional Fourier transform is performed on the detection signal, and frequency characteristics in the main scanning and sub-scanning directions are acquired. Then, based on the acquired frequency characteristics in the main scanning / sub-scanning direction, a positional deviation of printing in the main scanning / sub-scanning direction is detected.

  The two-dimensional sensor 30 detects the adjustment patterns 101 and 102 formed on the recording medium 16 and outputs a detection signal. The printing mechanism of the present embodiment detects the adjustment patterns 101 and 102 formed on the recording medium 16 with the two-dimensional sensor 30 while moving the carriage 5 in the main scanning direction at a low speed, and a control unit (not shown) acquires the detection signal. . The detection signal is a signal that changes in accordance with a portion where the adjustment patterns 101 and 102 are present on the recording medium 16 and a portion where the adjustment pattern 101 is not present.

  The two-dimensional sensor 30 is configured by, for example, a reflective optical sensor, and includes a light emitting unit 301, a diffusion prism 302, an imaging lens 303, and a light receiving unit 304, as shown in FIG.

  The light emitting unit 301 emits light, and the light emitted from the light emitting unit 301 is adjusted by the diffusion prism 302, and the adjusted light is irradiated onto the recording medium 16. The diffusion prism 302 is for efficiently irradiating the adjustment patterns 101 and 102 with the light emitted from the light emitting unit 301.

  The reflected light reflected from the surface of the recording medium 16 is imaged by the imaging lens 303, and the imaged reflected light is received by the light receiving unit 304. The light receiving unit 304 detects the light amount (light intensity) of the received reflected light, converts the detected light amount into an electrical signal, and generates a detection signal.

  Since the amount of light (light intensity) varies depending on whether or not there is a dot (printing), the two-dimensional sensor 30 is formed on the recording medium 16 based on the amount of light (light intensity) detected by the light receiving unit 304. In addition, a portion with and without a dot (printing) constituting the adjustment patterns 101 and 102 is detected.

  The configuration of the two-dimensional sensor 30 and the detection method thereof are not particularly limited as long as the adjustment patterns 101 and 102 formed on the recording medium 16 can be detected, and any configuration and detection method can be applied. . Similarly, the arrangement position of the two-dimensional sensor 30 is not particularly limited as long as it can detect the adjustment patterns 101 and 102 formed on the recording medium 16, and can be arranged at an arbitrary position. is there. For example, as shown in FIGS. 2 and 3, the recording head 6 may be integrated with the recording head 6, or may be disposed separately from the recording head 6. When the two-dimensional sensor 30 is mounted on the carriage 5, it is preferable to mount it at the same position as the printing position where the adjustment patterns 101 and 102 are printed.

<Configuration example of control mechanism of recording apparatus>
Next, a configuration example of the control mechanism of the recording apparatus of the present embodiment will be described with reference to FIG.

  The control mechanism of the recording apparatus according to the present embodiment includes a control unit 107, a main storage unit 118, a sub storage unit 119, a carriage 5, a main scanning driver 109, a recording head 6, a recording head driver 111, an encoder sensor 41, and a two-dimensional sensor 30. The paper transport unit 112, the sub-scanning driver 113, the image processing unit 120, and the adjustment pattern generation unit 121 are included.

  The control unit 107 supplies recording data and a drive control signal (pulse signal) to the main storage unit 118 and each driver, and controls the entire recording apparatus. The control unit 107 controls driving of the carriage 5 in the main scanning direction via the main scanning driver 109. Further, the ink ejection timing by the recording head 6 is controlled via the recording head driver 111. Further, the driving of the paper conveyance unit 112 (conveyance belt or the like) in the sub scanning direction is controlled via the sub scanning driver 113.

  The encoder sensor 41 outputs an encoder value obtained by detecting the mark on the encoder sheet 40 to the control unit 107. The control unit 107 controls driving of the carriage 5 in the main scanning direction via the main scanning driver 109 based on the encoder value.

  The two-dimensional sensor 30 detects the adjustment patterns 101 and 102 formed on the recording medium 16 and outputs detection signals to the control unit 107. The control unit 107 stores the detection signal detected by the two-dimensional sensor 30 in association with the encoder value detected by the encoder sensor 41 when the detection signal is obtained in the main storage unit 118.

  The main storage unit 118 stores necessary information. For example, a program such as a processing procedure executed by the control unit 107 is stored. The main storage unit 118 can be rewritten from the outside. The secondary storage unit 119 is used as a working memory or the like.

  The control unit 107 according to the present embodiment reads image information from the image processing unit 120 according to the print mode, and converts the read image information into an image format for the recording head in the sub storage unit 119. Then, the image information converted in the secondary storage unit 119 is transferred to the recording head driver 111. The recording head driver 111 generates various timing signals for driving the head in accordance with the printing mode, and transfers the various timing signals for driving the head and image information to the recording head 6 to perform printing processing.

  Further, the control unit 107 controls driving of the carriage 5 in the main scanning direction via the main scanning driver 109 according to the print mode, and controls the paper conveying unit 112 (conveying belt or the like) via the sub scanning driver 113. Controls driving in the sub-scanning direction to perform printing operation.

  In addition, when performing the misregistration detection operation, the control unit 107 transmits parameters for generating the adjustment patterns 101 and 102 to the adjustment pattern generation unit 121. The adjustment pattern generation unit 121 uses the adjustment parameters 101 and 102 based on the parameters. Is generated. The control unit 107 converts the adjustment patterns 101 and 102 generated by the adjustment pattern generation unit 121 into an image format for the recording head in the sub storage unit 119 in the same manner as in normal printing. Then, the main scanning driver 109, the carriage 5, the recording head driver 111, the recording head 6, the sub-scanning driver 113, the paper transport unit 112, and the like are controlled in the same manner as in normal printing, and the adjustment patterns 101 and 102 are printed on the recording medium 16. After printing the adjustment patterns 101 and 102, the control unit 107 detects the adjustment patterns 101 and 102 with the two-dimensional sensor 30 while driving the carriage 5 with the main scanning driver 109, and the adjustment patterns 101 and 102 are obtained. The detection signals are sequentially stored in the secondary storage unit 119. The control unit 107 divides the detection signal stored in the sub storage unit 119 for each predetermined area, performs frequency analysis such as two-dimensional Fourier transform on the divided detection signal, and performs frequency analysis in the main scanning and sub scanning directions. Get characteristics. The control unit 107 determines the positional deviation of printing in the main scanning / sub-scanning direction from the difference between the acquired frequency characteristics in the main scanning / sub-scanning direction and a predetermined reference frequency characteristic in the main scanning / sub-scanning direction. Detect.

<Method for forming adjustment patterns 101 and 102>
Next, a method for forming the adjustment patterns 101 and 102 will be described with reference to FIG.

  The recording apparatus according to the present embodiment performs control so that the forward path adjustment pattern 101 is printed on the recording medium 16 at regular intervals in the main scanning direction according to a predetermined print timing signal stored in the main storage unit 118 during the forward movement. Then, without performing the conveyance control of the recording medium 16, control is performed so that the return path adjustment pattern 102 is printed according to the print timing signal based on the center position of the print interval in the main scanning direction of the forward path adjustment pattern 101 during the backward path movement. .

  Since the recording apparatus of the present embodiment performs printing processing in both directions when the carriage 5 is reciprocated, as shown in FIG. 7, the return path adjustment pattern 102 is placed at the center position of the print interval in the main scanning direction of the forward path adjustment pattern 101. Printing is performed to form the adjustment patterns 101 and 102, and the adjustment patterns 101 and 102 are used to detect the positional deviation of the printing in the main scanning direction.

  It should be noted that the print interval in the main scanning direction between the forward path adjustment pattern 101 and the backward path adjustment pattern 102 is preferably 1 dot or more. Thereby, it is possible to prevent the dot from being crushed due to ink bleeding.

  Further, as shown in FIG. 4, the recording apparatus according to the present embodiment is configured to print the same color in the sub-scanning direction with different nozzle rows by one dot, so that the same color is printed as shown in FIG. The plurality of nozzle rows to be printed alternately print dots in the sub-scanning direction. For example, when the same color is configured to print in the sub-scanning direction with two nozzle rows that differ by one dot, the odd-numbered dots in the sub-scanning direction print dots in one nozzle row, and the next sub-scanning direction In the even-numbered dots, dots are printed by the other nozzle row. For this reason, it is possible to detect the positional deviation of the printing in the sub-scanning direction between the plurality of nozzles used for printing by using the dots printed by the plurality of nozzle rows alternately in the sub-scanning direction.

  It should be noted that it is preferable that the printing interval in the sub-scanning direction of the dots constituting the adjustment patterns 101 and 102 be an even number of dots from the printed nozzle. Thereby, it is possible to prevent the dots printed in the sub-scanning direction from different nozzle rows from overlapping each other.

<Frequency characteristics analysis method>
Next, a method for analyzing the frequency characteristics of the detection signal will be described.

  The recording apparatus of the present embodiment detects the adjustment patterns 101 and 102 by the two-dimensional sensor 30 while moving the carriage 5 shown in FIGS. 2 and 3 at a low speed in the main scanning direction, and acquires detection signals of the adjustment patterns 101 and 102. Then, the detection signal detected by the two-dimensional sensor 30 and the encoder value acquired by the encoder sensor 41 when the detection signal is detected are stored in the main storage unit 118 in association with each other. The recording device divides the detection signal stored in the main storage unit 118 into predetermined areas based on the encoder values stored in the main storage unit 118, and the divided detection signal has a frequency such as two-dimensional Fourier transform. Analysis is performed to obtain frequency characteristics in the main scanning and sub-scanning directions. Then, based on the difference between the acquired frequency characteristic in the main scanning / sub-scanning direction and a predetermined reference frequency characteristic in the main scanning / sub-scanning direction, the positional deviation of printing in the main scanning / sub-scanning direction is detected.

  If the printing process is performed according to the optimum print timing signal during the reciprocating movement in the main scanning direction, the adjustment patterns 101 and 102 that are printed during the reciprocating movement are printed at regular intervals in the main scanning direction as shown in FIG. The When the two-dimensional sensor 30 detects the adjustment patterns 101 and 102 shown in FIG. 8 and two-dimensional Fourier transforms the detection signals, the reference frequency characteristic in the main scanning direction is obtained as shown in FIG.

  As shown in the adjustment patterns 101 and 102 shown in FIG. 8, when the backward adjustment pattern 102 exists at the center position of the forward adjustment pattern 101, the forward adjustment pattern 101 and the backward adjustment pattern 102 do not overlap and are arranged at a constant interval with a width of h1. Will be. The reference frequency (H1) in the main scanning direction is that the return path adjustment pattern 102 exists at the center position of the forward path adjustment pattern 101 as shown in FIG. 8, and the interval between the forward path adjustment pattern 101 and the return path adjustment pattern 102 is h1. This is the frequency of the detection signal obtained when Since the control unit 107 knows in advance the width h1 when the return path adjustment pattern 102 reaches the center position of the forward path adjustment pattern 101, the control unit 107 can previously know the reference frequency (H1) in the main scanning direction.

  If there is a printing misalignment in the main scanning direction due to the misalignment of the printing in the main scanning direction of the returning path adjustment pattern 102 printed during the backward movement, the adjustment pattern configured to be printed during the reciprocating movement 101 and 102 are not printed at regular intervals in the main scanning direction. As shown in FIG. 10, the forward path adjustment pattern 101 printed during the forward path and the backward path adjustment pattern 102 printed during the backward path approach or separate from each other. The printout is biased. For this reason, the interval between the forward path adjustment pattern 101 and the backward path adjustment pattern 102 is not a constant interval, but two intervals (b1, a1) appear. When the two-dimensional sensor 30 detects the adjustment patterns 101 and 102 shown in FIG. 10 and two-dimensional Fourier transforms the detection signals, two frequency components different from the reference frequency (H1) in the main scanning direction are obtained as shown in FIG. (A1, B1) is obtained. Therefore, the frequency components (A1, B1) in the main scanning direction and the reference frequency (H1) in the main scanning direction are compared, and the difference is calculated. Based on the difference, printing in the main scanning direction is performed. Misalignment can be detected. For example, when there is no print position misalignment in the main scanning direction, the reference frequency (H1) in the main scan direction is acquired and the difference becomes 0. Therefore, there is a print position misalignment in the main scanning direction. It can be detected that there is not. Also, if there is a print misalignment in the main scan direction, the frequency components (A1, B1) in the main scan direction are acquired and the difference is obtained, so the print misalignment occurs in the main scan direction. Can be detected.

  As shown in FIG. 7, the recording apparatus of the present embodiment prints the return path adjustment pattern 102 at the center position of the print interval in the main scanning direction of the forward path adjustment pattern 101, and the forward path adjustment pattern 101 and the backward path adjustment pattern 102 are printed. Are not overlapped in the main scanning direction. For this reason, frequency analysis in the main scanning direction can be facilitated.

  For example, as shown in FIG. 12A, in the case of the adjustment patterns 101 and 102 where the forward path adjustment pattern 101 and the backward path adjustment pattern 102 overlap in the main scanning direction, the detection signal obtained from the adjustment patterns 101 and 102 is as shown in FIG. The waveform has a constant period (frequency H) as shown in (a), and the output value of the Fourier transform is higher than the output value of the reference frequency H as shown in FIG.

  In addition, as shown in FIG. 12B, in the case of the adjustment patterns 101 and 102 in which the forward pass adjustment pattern 101 and the backward pass adjustment pattern 102 are shifted by half a dot in the main scanning direction, the phenomenon that the line (pattern) becomes fat as a result. Occurs. For this reason, the detection signal obtained from the adjustment patterns 101 and 102 has a wide waveform width as shown in FIG. When frequency analysis is performed on a detection signal having a wide waveform width, for example, the reference frequency is calculated based on the median value of the detection signal or the edge (start position, etc.) of the detection signal. As a result, since the waveform period is the same (frequency H) as that of the adjustment patterns 101 and 102 shown in FIG. 12A, the output value of the frequency characteristic is as shown in FIG. As shown, the output value of the reference frequency H becomes high.

  When the adjustment patterns 101 and 102 are formed by superimposing the forward path pattern 101 and the return path pattern 102, if the printing position shift is less than 1 dot, the line of the adjustment patterns 101 and 102 is displayed as shown in FIG. Will become fat. However, even if the lines of the adjustment patterns 101 and 102 are thick, the period of the adjustment patterns 101 and 102 itself does not change. As a result, the waveform period is the same as that of the adjustment patterns 101 and 102 shown in FIG. Become. For this reason, when the adjustment patterns 101 and 102 are formed by superimposing the forward path pattern 101 and the backward path pattern 102, it may not be possible to accurately detect the positional deviation of printing.

  In the above description, the case where the adjustment patterns 101 and 102 are formed with one dot has been described as an example. However, the same can be said when the adjustment patterns 101 and 102 are formed of a plurality of dots.

  For this reason, in this embodiment, as shown in FIG. 7, the backward adjustment pattern 102 is printed at the center position of the printing interval in the main scanning direction of the outward adjustment pattern 101, and the forward adjustment pattern 101 and the backward adjustment pattern 102 are mainly used. It is made not to overlap in the scanning direction. For this reason, the phenomenon that the lines of the adjustment patterns 101 and 102 become thick does not occur. As a result, the above-mentioned problem does not occur, and the printing position shift can be detected easily and accurately.

  As for the sub-scanning direction, if the assembly error of each recording head 6 is an interval equivalent to a predetermined resolution, even if dots are printed alternately in the sub-scanning direction with each nozzle row constituting one color, As shown in FIG. 13, dots printed in the sub-scanning direction are printed at regular intervals in the sub-scanning direction. When the two-dimensional sensor 30 detects the adjustment patterns 101 and 102 shown in FIG. 13 and two-dimensional Fourier transforms the detection signals, the reference frequency characteristic in the sub-scanning direction is obtained as shown in FIG.

  When dots are printed at regular intervals in the sub-scanning direction as in the adjustment patterns 101 and 102 shown in FIG. 13, the printed dots are arranged at regular intervals with a width of h2 without overlapping each other. The reference frequency (H2) in the sub-scanning direction is a frequency of a detection signal obtained when the interval between dots printed in the sub-scanning direction becomes h2, as shown in FIG. Since the control unit 107 knows in advance the width h2 when the dots printed in the sub-scanning direction are at regular intervals, the control unit 107 can grasp in advance the reference frequency (H2) in the sub-scanning direction.

  If there is a print misalignment in the sub-scanning direction due to factors such as the assembly error of each recording head 6 (the print misalignment in the sub-scanning direction of the dots constituting the forward pass adjustment pattern 101 has occurred) Or when the dots constituting the return path adjustment pattern 102 are misaligned in the sub-scanning direction), the dots constituting the adjustment patterns 101 and 102 are not printed at regular intervals in the sub-scanning direction. As shown in FIG. 15, the dots constituting the adjustment patterns 101 and 102 are printed in a biased manner by approaching or separating from each other. For this reason, the interval between dots printed in the sub-scanning direction is not a constant interval, but two intervals (b2, a2) appear. When the adjustment patterns 101 and 102 shown in FIG. 15 are detected by the two-dimensional sensor 30 and the detected signals are two-dimensionally Fourier transformed, as shown in FIG. 16, two frequencies different from the reference frequency characteristic (H2) in the sub-scanning direction are obtained. Ingredients (A2, B2) are obtained. Therefore, by comparing the frequency components (A2, B2) in the sub-scanning direction with the reference frequency (H2) in the sub-scanning direction and calculating the difference, it is possible to detect a print misalignment in the sub-scanning direction. Can do. For example, when there is no print misalignment in the sub-scanning direction, the reference frequency (H2) in the sub-scanning direction is acquired, and the difference becomes 0. Therefore, the print misalignment in the sub-scanning direction has occurred. It can be detected that there is not. Also, if there is a print misalignment in the sub-scanning direction, the frequency components (A2, B2) in the sub-scanning direction are acquired and the difference is obtained, so the print misalignment in the sub-scanning direction occurs. Can be detected.

  Further, when printing position shifts occur simultaneously in the main scanning and sub-scanning directions, dots are not printed at regular intervals in the main scanning direction and the sub-scanning direction as shown in FIG. Dots are printed in a biased manner as they approach or separate from the sub-scanning direction and the main scanning direction, respectively. When the adjustment patterns 101 and 102 shown in FIG. 17 are detected by the two-dimensional sensor 30 and the detection signals are two-dimensionally Fourier transformed, the reference frequency characteristics differ from each other in the main scanning and sub-scanning directions as shown in FIG. Two frequency components appear, and a total of four frequency components (A1, B1, A2, B2) are obtained. Therefore, by comparing the frequency components (A1, B1, A2, B2) in the main scanning / sub-scanning direction with the reference frequencies (H1, H2) in the main scanning / sub-scanning direction, and calculating the difference, It is possible to detect a positional deviation in printing in the main scanning / sub-scanning directions.

  In addition, the positional deviation adjustment of the printing in the main scanning direction is performed by two frequency components (A1, B1) in the main scanning direction acquired at the time of the occurrence of the positional deviation and a predetermined reference frequency (H1) in the main scanning direction. If the difference is obtained and the print timing signal at the time of backward printing is adjusted based on the difference, the positional deviation of the print in the main scanning direction can be adjusted.

  In addition, the positional deviation adjustment of the printing in the sub-scanning direction is made up of two frequency components (A2, B2) in the sub-scanning direction acquired when the positional deviation occurs and a predetermined reference frequency (H2) in the sub-scanning direction. If the difference is obtained and the nozzle for printing is adjusted based on the difference, the printing position deviation in the sub-scanning direction can be adjusted.

<Processing operation example of recording apparatus>
Next, an example of processing operation of the recording apparatus of the present embodiment will be described with reference to FIG. FIG. 19 is a diagram illustrating an example of a processing operation for detecting a printing misalignment.

  The control unit 107 moves the carriage 5 to the initial position (step S1). The initial position is a start position (outward scan start position) for printing an image (dot) on the recording medium 16 in the moving direction (main scanning direction) of the carriage 5. At this time, the recording medium 16 is conveyed to a position where an image can be formed.

  Next, the control unit 107 generates the forward path adjustment pattern 101 (step S2).

  Next, the control unit 107 moves the carriage 5 in the forward direction (step S3).

  At this time, the control unit 107 prints the forward path adjustment pattern 101 on the recording medium 16 in accordance with a predetermined print timing signal stored in the main storage unit 118 (step S4). As a result, the forward path adjustment pattern 101 shown in FIG. 7 is printed on the recording medium 16.

  When the movement of the carriage 5 in the forward direction is completed (step S5), the control unit 107 generates the return path adjustment pattern 102 (step S6). Next, the control unit 107 moves the carriage 5 in the backward direction (step S7).

  The control unit 107 prints the return path adjustment pattern 102 on the recording medium 16 in accordance with a predetermined print timing signal stored in the main storage unit 118 (step S8). As a result, the return path adjustment pattern 102 shown in FIG. 7 is printed on the recording medium 16. As a result, adjustment patterns 101 and 102 constituted by the forward path adjustment pattern 101 and the backward path adjustment pattern 102 are formed on the recording medium 16.

  When the movement of the carriage 5 in the backward direction is completed (step S9), the control unit 107 moves the carriage 5 to the initial position (step S10).

  The control unit 107 transports the recording medium 16 so that the adjustment patterns 101 and 102 are positioned directly below the two-dimensional sensor 30 (step S11).

  The control unit 107 moves the carriage 5 in the forward direction at a low speed (step S12), detects the adjustment patterns 101 and 102 with the two-dimensional sensor 30, and acquires a detection signal (step S13).

  The control unit 107 stores the detection signals of the adjustment patterns 101 and 102 detected by the two-dimensional sensor 30 and the encoder values acquired by the encoder sensor 41 when acquiring the detection signals of the adjustment patterns 101 and 102 in association with each other in the main storage unit 118. (Step S14).

  When the detection operation of the adjustment patterns 101 and 102 is completed (step S15), the control unit 107 moves the carriage 5 to the initial position (step S16).

  The control unit 107 divides the detection signal stored in the main storage unit 118 into predetermined regions, performs frequency analysis such as two-dimensional Fourier transform on the divided detection signal, and performs frequency analysis in the main scanning and sub-scanning directions. A characteristic is acquired (step S17). Then, the positional deviation of the printing in the main scanning / sub-scanning direction is detected from the difference between the acquired frequency characteristic in the main scanning / sub-scanning direction and a predetermined reference frequency characteristic in the main scanning / sub-scanning direction ( Step S18).

<Operation / Effect of Recording Apparatus of this Embodiment>
As described above, the recording apparatus of the present embodiment records on the recording medium 16 the adjustment patterns 101 and 102 configured by the forward path adjustment pattern 101 printed during the forward movement and the backward path adjustment pattern 102 printed during the backward movement. Then, the adjustment patterns 101 and 102 recorded on the recording medium 16 are detected by the two-dimensional sensor 30, and detection signals corresponding to the adjustment patterns 101 and 102 are acquired. Then, the detection signal is analyzed, and the two-dimensional frequency characteristic of the detection signal is acquired. Then, based on the two-dimensional frequency characteristics, a positional deviation between dots printed in the main scanning direction and a positional deviation between dots printed in the sub-scanning direction are detected.

  Thereby, the recording apparatus of the present embodiment can detect a positional deviation of printing in the main scanning / sub-scanning directions.

  Further, the recording apparatus of the present embodiment prints the return path adjustment pattern 102 at the center position of the printing interval in the main scanning direction of the forward path adjustment pattern 101 so that the forward path adjustment pattern 101 and the backward path adjustment pattern 102 do not overlap. . For this reason, the phenomenon that the lines of the adjustment patterns 101 and 102 become thick does not occur. As a result, it is possible to easily and accurately detect a printing misalignment.

(Second Embodiment)
Next, a second embodiment will be described.

  In the first embodiment, the adjustment patterns 101 and 102 shown in FIG. 7 are formed, and based on the detection signals of the formed adjustment patterns 101 and 102, the printing position deviation in the main scanning and sub-scanning directions is detected.

  In the second embodiment, as shown in FIG. 20, the main scanning direction is divided into a plurality of regions (for example, the left region, the center region, and the right region), and the adjustment patterns 101 and 102 shown in FIG. 7 are formed for each region. To do. Then, the adjustment patterns 101 and 102 formed for each area are detected for each area, and the positional deviation of printing in the main scanning and sub-scanning directions is detected for each area.

  If the amount of deviation of the print position is the same throughout the main scanning direction, the frequency characteristics obtained for each region are the same. However, in a device having a long scanning movement distance in the main scanning direction such as a wide-width machine, the positional deviation amount differs for each region, and the frequency characteristics obtained for each region are likely to be different.

  For this reason, as shown in FIG. 20, the printing apparatus according to the present embodiment divides the main scanning direction into a plurality of areas (for example, the left area, the central area, and the right area) and performs printing in the main scanning and sub-scanning directions. A positional shift is detected for each area. As a result, it is possible to detect the positional deviation of printing more accurately.

  The above-described embodiment is a preferred embodiment of the present invention, and the scope of the present invention is not limited to the above-described embodiment alone, and various modifications are made without departing from the gist of the present invention. Implementation is possible.

  For example, in the above embodiment, as shown in FIG. 19, the recording medium 16 is transported so that the adjustment patterns 101 and 102 are positioned directly below the two-dimensional sensor 30 (step S10). However, when the two-dimensional sensor 30 is mounted on the carriage 5 so as to be in the same position as the printing position of the adjustment patterns 101 and 102, it is possible not to perform the process of step S10.

  In the above embodiment, the two-dimensional sensor 30 is mounted on the carriage 5. However, as shown in FIG. 21, it is also possible to provide a carriage 38 dedicated to the two-dimensional sensor 30 and move the carriage 38 in the main scanning direction so as to detect the adjustment patterns 101 and 102.

  In the above embodiment, the detection process of the adjustment patterns 101 and 102 is performed during the forward movement. However, it is also possible to construct such that detection processing is performed even when moving in the return path. In this case, the detection signal detected during the forward movement and the detection signal detected during the backward movement are averaged. Thereby, it is possible to reduce the error of the detection signal.

  Further, the control operation of each unit constituting the recording apparatus of the present embodiment described above can be executed using hardware, software, or a combined configuration of both.

  In the case of executing processing using software, it is possible to install and execute a program in which a processing sequence is recorded in a memory in a computer incorporated in dedicated hardware. Alternatively, the program can be installed and executed on a general-purpose computer capable of executing various processes.

  For example, the program can be recorded in advance on a hard disk or ROM (Read Only Memory) as a recording medium. Alternatively, the program can be stored (recorded) temporarily or permanently in a removable recording medium. Such a removable recording medium can be provided as so-called package software. Examples of the removable recording medium include a floppy (registered trademark) disk, a CD-ROM (Compact Disc Read Only Memory), an MO (Magneto optical) disk, a DVD (Digital Versatile Disc), a magnetic disk, and a semiconductor memory.

  The program is installed on the computer from the removable recording medium as described above. In addition, it is wirelessly transferred from the download site to the computer. In addition, it is transferred to a computer via a network by wire.

  The recording apparatus according to the present embodiment is not only executed in time series according to the processing operation described in the above embodiment, but also the processing capability of the apparatus that executes the process, or in parallel or individually as required. It is also possible to build to run on

  The present invention is suitable for an ink jet recording apparatus.

DESCRIPTION OF SYMBOLS 5 Carriage 6 Recording head 16 Recording medium 30 Two-dimensional sensor 41 Encoder sensor 40 Encoder sheet 101 Forward path adjustment pattern 102 Return path adjustment pattern 107 Control part 109 Main scanning driver 111 Recording head driver 112 Paper conveyance part 113 Sub scanning driver 118 Main memory part 119 Sub storage unit 120 Image processing unit 121 Adjustment pattern generation unit

JP 2004-358759 A

Claims (6)

A carriage equipped with a recording head provided with a plurality of nozzle arrays in the sub-scanning direction in which a plurality of nozzles that eject ink is arranged in the main scanning direction is reciprocated in the main scanning direction. A recording device for recording an image on
A forward adjustment pattern in which dots printed on the recording medium from a plurality of nozzle rows are arranged at regular intervals in the sub-scanning direction, and is printed at regular intervals in the main scanning direction during forward movement,
A return path adjustment pattern in which dots printed on the recording medium from the nozzle row are arranged at regular intervals in the sub-scanning direction is printed when the forward path is moved with reference to the center position of the print interval in the main scanning direction of the forward path adjustment pattern. ,
Recording means for recording an adjustment pattern composed of the forward path adjustment pattern and the return path adjustment pattern on the recording medium;
A two-dimensional sensor that detects the adjustment pattern and outputs a detection signal according to the adjustment pattern;
Analyzing means for analyzing the detection signal and obtaining a two-dimensional frequency characteristic of the detection signal;
Based on the two-dimensional frequency characteristics, detection means for detecting a positional deviation between the dots printed in the main scanning direction and a positional deviation between the dots printed in the sub-scanning direction;
A recording apparatus comprising: The detection means includes
Comparing the two-dimensional frequency characteristic with a predetermined two-dimensional reference frequency characteristic, the positional deviation between the dots printed in the main scanning direction and the positional deviation between the dots printed in the sub-scanning direction The recording apparatus according to claim 1, wherein: The positional deviation between the dots printed in the main scanning direction is a positional deviation between the dots of the backward path adjustment pattern printed during the backward movement and the forward path adjustment pattern printed during the forward movement,
The positional deviation between the dots printed in the sub-scanning direction is a positional deviation in the sub-scanning direction between a plurality of nozzle rows that print the return path adjustment pattern and the forward path adjustment pattern. 2. The recording device according to 2.   The recording of the adjustment pattern performed by the recording unit and the detection of the positional deviation between the dots performed by the detection unit are performed for each predetermined region in the main scanning direction. The recording apparatus according to any one of the above. A carriage equipped with a recording head provided with a plurality of nozzle arrays in the sub-scanning direction in which a plurality of nozzles that eject ink is arranged in the main scanning direction is reciprocated in the main scanning direction. A control method performed by a recording apparatus for recording an image on
A forward adjustment pattern in which dots printed on the recording medium from a plurality of nozzle rows are arranged at regular intervals in the sub-scanning direction, and is printed at regular intervals in the main scanning direction during forward movement,
A return path adjustment pattern in which dots printed on the recording medium from the nozzle row are arranged at regular intervals in the sub-scanning direction is printed when the forward path is moved with reference to the center position of the print interval in the main scanning direction of the forward path adjustment pattern. ,
A recording step of recording an adjustment pattern composed of the forward path adjustment pattern and the return path adjustment pattern on the recording medium;
An output step of detecting the adjustment pattern and outputting a detection signal corresponding to the adjustment pattern;
Analyzing the detection signal and obtaining a two-dimensional frequency characteristic of the detection signal;
Based on the two-dimensional frequency characteristics, a detection step of detecting a positional deviation between the dots printed in the main scanning direction and a positional deviation between the dots printed in the sub-scanning direction;
A control method characterized by comprising: A carriage equipped with a recording head provided with a plurality of nozzle arrays in the sub-scanning direction in which a plurality of nozzles that eject ink is arranged in the main scanning direction is reciprocated in the main scanning direction. A program to be executed by a recording apparatus for recording an image on
A forward adjustment pattern in which dots printed on the recording medium from a plurality of nozzle rows are arranged at regular intervals in the sub-scanning direction, and is printed at regular intervals in the main scanning direction during forward movement,
A return path adjustment pattern in which dots printed on the recording medium from the nozzle row are arranged at regular intervals in the sub-scanning direction is printed when the forward path is moved with reference to the center position of the print interval in the main scanning direction of the forward path adjustment pattern. ,
A recording process for recording an adjustment pattern composed of the forward path adjustment pattern and the return path adjustment pattern on the recording medium;
An output process for detecting the adjustment pattern and outputting a detection signal corresponding to the adjustment pattern;
Analyzing the detection signal and obtaining a two-dimensional frequency characteristic of the detection signal;
Based on the two-dimensional frequency characteristics, a detection process for detecting a positional deviation between the dots printed in the main scanning direction and a positional deviation between the dots printed in the sub-scanning direction;
A program characterized by causing a computer to execute.

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