Recording device and control method

Abstract

To reduce deviations of a recording position caused by an inclination of a recording head.SOLUTION: A recording device comprises: a plurality of recording heads arranged in a first direction; reading means that reads out test patterns recorded on a recording medium; analyzing means that analyzes the test patterns read out by the reading means; and correcting means that corrects deviations of the recording position on the basis of the analyzed result. Each recording head has a plurality of chips arranged in the longitudinal direction of the head, where each chip has a plurality of nozzles arranged in the longitudinal direction. The test patterns include a plurality of determination patterns arranged in a second direction crossing the first direction. Each determination pattern includes a pattern recorded by each recording head. Positional deviations caused by an inclination in the longitudinal direction of each recording head are analyzed on the basis of the plurality of determination patterns and deviations of the recording position are corrected on the basis of the analyzed positional deviations.SELECTED DRAWING: Figure 5

Description

Technical Field

[0001] The present invention relates to a recording apparatus and a control method.

Background Art

[0002] A long recording head in which a plurality of head chips (head substrates) are connected and arranged in the nozzle array direction is known. A recording head called a full-line head is an example of this. In such a recording head, the mounting error affects the deviation of the recording position (for example, the deviation of the ink landing position). This deviation causes a decrease in recording quality. Patent Documents 1 to 3 disclose techniques for recording a test pattern and correcting the deviation of the recording position due to the mounting error from the reading result.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Patent Document 3

Summary of the Invention

Problems to be Solved by the Invention

[0004] In a long recording head in which a plurality of head chips are connected and arranged in the nozzle array direction, the influence of the inclination with respect to the main scanning direction on the deviation of the recording position becomes high. There is room for improvement in the conventional technology in terms of specifying the inclination of the recording head.

[0005] The present invention provides a technique capable of reducing the deviation of the recording position due to the inclination of the recording head.

Means for Solving the Problems

[0006] According to the present invention, A plurality of recording heads arranged in a first direction, Moving means for relatively moving the plurality of recording heads and a recording medium in the first direction, Reading means for reading a test pattern recorded on a recording medium by the plurality of recording heads, Analyzing means for analyzing the test pattern read by the reading means, Correction means for correcting a deviation in the recording position of the plurality of recording heads based on the result of the analysis by the analyzing means, and each recording head has a plurality of chips arranged in a longitudinal direction of the recording head intersecting the first direction, and each chip has a plurality of nozzles arranged in the longitudinal direction, and is a recording device, The test pattern includes a plurality of determination patterns arranged in a second direction intersecting the first direction, Each determination pattern includes a pattern recorded by each recording head, The analyzing means analyzes a positional deviation caused by an inclination in the longitudinal direction of each recording head based on the plurality of determination patterns, The correction means corrects a deviation in the recording position based on the positional deviation analyzed by the analyzing means, A recording device is provided, which is characterized by the above.

Advantages of the Invention

[0007] According to the present invention, it is possible to provide a technique capable of reducing a deviation in the recording position due to an inclination of a recording head.

Brief Description of the Drawings

[0008]

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Embodiments for Carrying Out the Invention

[0009] Hereinafter, embodiments will be described in detail with reference to the accompanying drawings. Note that the following embodiments do not limit the invention according to the claims. Although a plurality of features are described in the embodiments, not all of these plurality of features are essential to the invention, and the plurality of features may be arbitrarily combined. Furthermore, in the accompanying drawings, the same or similar configurations are denoted by the same reference numerals, and redundant descriptions are omitted.

[0010] Hereinafter, an embodiment of the present invention will be described in detail with reference to the accompanying drawings. In the following description, a recording apparatus using an inkjet recording method will be described as an example. As the recording apparatus, for example, a single-function printer having only a recording function may be used, or, for example, a multifunction printer having a plurality of functions such as a recording function, a FAX function, and a scanner function may also be used. Further, for example, a manufacturing apparatus for manufacturing a color filter, an electronic device, an optical device, a micro-structure, etc. by a predetermined recording method may also be used.

[0011] Note that "recording" includes not only the case of forming significant information such as characters and graphics, but also the case of forming an image, a pattern, a pattern, etc. on a recording medium widely regardless of whether it is significant or not, or performing processing on the medium, regardless of whether it is made manifest so that it can be perceived visually by humans. In addition, in the present embodiment, a sheet-like paper is assumed as the "recording medium", but it may be cloth, a plastic film, or the like. "Ink" includes a liquid that can be used for forming an image, a pattern, a pattern, etc., processing the recording medium, or processing the ink (for example, solidifying or insolubilizing a colorant in the ink applied to the recording medium) by being applied on the recording medium.

[0012] <First Embodiment> <Outline of the Recording Apparatus> FIG. 1 is a diagram showing an example of the internal configuration of a recording apparatus 20 according to an embodiment of the present invention. The recording apparatus 20 is a high-speed line printer that uses a continuous sheet wound in a roll shape and is compatible with both single-sided recording and double-sided recording. Such a recording apparatus 20 is suitable for, for example, the field of printing a large number of sheets in a print lab or the like.

[0013] Inside the recording apparatus 20, a sheet supply unit 1, a decal unit 2, a skew correction unit 3, a recording unit 4, an inspection unit 5, a cutter unit 6, an information recording unit 7, a drying unit 8, a sheet winding unit 9, and a discharge conveyance unit 10 are provided. In addition, inside the recording apparatus 20, a sorter unit 11, a discharge tray 12, a control unit 13, etc. are also provided.

[0014] The sheet S, which is a recording medium, is conveyed by a conveyance mechanism equipped with roller pairs and belts along the sheet conveyance path indicated by a solid line in the figure. On this conveyance path, each part provided in the recording apparatus 20 performs various processes on the sheet S.

[0015] The sheet supply unit 1 stores and supplies a continuous sheet wound in a roll. The sheet supply unit 1 is configured to be able to store two rolls R1 and R2, and selectively pulls out and supplies the sheet S. Note that the number of rolls that can be stored does not necessarily have to be two, and it may be configured to be able to store one or three or more rolls.

[0016] The decal unit 2 reduces the curl (warp) of the sheet S supplied from the sheet supply unit 1. In the decal unit 2, the sheet S is curved using two pinch rollers against one drive roller so as to give a reverse warp. Thereby, the curl of the sheet S is reduced.

[0017] The skew correction unit 3 corrects the skew (inclination with respect to the original traveling direction) of the sheet S that has passed through the decal unit 2. In the skew correction unit 3, the skew of the sheet S is corrected by pressing the sheet end on the reference side against the guide member.

[0018] The recording unit 4 forms an image on the conveyed sheet and performs recording. In addition to a plurality of conveyance rollers that convey the sheet, the recording unit 4 is provided with a plurality of inkjet recording heads (hereinafter simply referred to as recording heads) 14. Each recording head 14 is composed of a full-line type recording head and has a recording width corresponding to the maximum width of the sheet S assumed to be used.

[0019] The plurality of recording heads 14 are arranged in parallel along the conveyance direction of the sheet S. In the present embodiment, four recording heads 14 corresponding to four colors of K (black), C (cyan), M (magenta), and Y (yellow) are provided. The arrangement order of the recording heads 14 is, for example, K, C, M, Y from the downstream side in the conveyance direction of the sheet S, and each recording head 14 is arranged with its recording width aligned along the conveyance direction of the sheet S.

[0020] Note that the number of colors and the number of recording heads do not necessarily have to be four and can be changed as appropriate. The inkjet method can employ a method using a heating element, a method using a piezo element, a method using an electrostatic element, a method using a MEMS element, etc. The ink of each color is supplied from an ink tank to the recording head 14 via an ink tube respectively.

[0021] The inspection unit 5 is provided with a reading unit 17. In the case of the present embodiment, the reading unit 17 is a CCD line sensor. The CCD line sensor is composed of, for example, a two-dimensional image sensor, and a plurality of reading elements are arranged in a direction intersecting the conveyance direction of the sheet S. In addition, the inspection unit 5 is also provided with a light emitting element or the like. With such a configuration, in the inspection unit 5, the pattern or image recorded on the sheet by the recording unit 4 is optically read, and the state of the nozzles of the recording head 14, the conveyance state of the sheet, the position of the image, etc. are inspected.

[0022] The cutter unit 6 is a mechanism for cutting the sheet after image recording to a predetermined length. The cutter unit 6 is provided with a plurality of conveyance rollers for sending the sheet to the next process. The information recording unit 7 records information such as a serial number and a date on the back surface of the cut sheet. The drying unit 8 heats the sheet on which the image has been recorded by the recording unit 4 to dry the applied ink (in a short time). The drying unit 8 is provided with a conveyance belt and conveyance rollers for sending the sheet to the next process.

[0023] When performing double-sided recording, the sheet winding unit 9 temporarily winds up the sheet S on which the recording on the front surface has been completed. The sheet winding unit 9 is provided with a winding drum that rotates to wind up the sheet S. After the recording on the front surface is completed, the sheet S that has not been cut by the cutter unit 6 is temporarily wound up on the winding drum. When the winding is completed, the winding drum rotates in the reverse direction, and the wound sheet S is sent to the recording unit 4 via the decal unit 2. Since this sheet S is reversed front and back, the recording unit 4 can perform recording on the back surface. The specific operation for double-sided recording will be described later.

[0024] The discharge conveyance unit 10 conveys the sheet S dried by the drying unit 8 to the sorter unit 11 after being cut by the cutter unit 6. The sorter unit 11 discharges the sheet S on which the image has been recorded to the discharge tray 12. At this time, the sheet S may be sorted and discharged to different discharge trays 12.

[0025] The control unit 13 is an electronic circuit that controls each part in the recording apparatus 20. The control unit 13 includes, for example, a controller 15 equipped with a processor such as a CPU, a storage device such as a semiconductor memory, various I / O interfaces, etc., a power supply, a display device, an input device, etc. The operation of the recording apparatus 20 is controlled based on a command from the controller 15 or an external device 16 (such as a host computer) connected to the controller 15 via an I / O interface.

[0026] <Operation Example> Next, with reference to FIGS. 2(a) and 2(b), the basic operation flow during the recording process will be described. Since the operation is different between single-sided recording and double-sided recording, each will be described separately. Here, FIG. 2(a) is a diagram for explaining the operation during single-sided recording. In FIG. 2(a), the conveyance path of the sheet S from when an image is recorded on the sheet S supplied from the sheet S supply unit 1 until it is discharged to the discharge tray 12 is shown by a thick line.

[0027] When the sheet S is supplied from the sheet S supply unit 1, after being processed in the decal unit 2 and the skew correction unit 3 respectively, an image is recorded on the surface of the sheet S in the recording unit 4. The sheet S on which the image is recorded, after passing through the inspection unit 5, is cut at a predetermined length in the cutter unit 6. The cut sheet S has information such as a date recorded on its back surface in the information recording unit 7 as required. Thereafter, the sheet S is dried one by one in the drying unit 8 and then discharged to the discharge tray 12 of the sorter unit 11 via the discharge conveyance unit 10.

[0028] Figure 2(b) is a diagram for explaining the operation during double-sided recording. During double-sided recording, following the recording sequence for the front surface of the sheet S, a recording sequence for the back surface of the sheet S is implemented. Note that in Figure 2(b), the conveyance path when recording an image on the front surface of the sheet S during double-sided recording is shown by a thick line.

[0029] Here, the operations in each unit from the sheet S supply unit 1 to the inspection unit 5 are the same as those during single-sided recording described with reference to Figure 2(a). The difference lies in the processing after the cutter unit 6. Specifically, when the sheet S is conveyed to the cutter unit 6, in the cutter unit 6, instead of cutting the sheet S at a predetermined length, the rear end of the recording area of the continuous sheet S is cut. When the sheet S is conveyed to the drying unit 8, in the drying unit 8, after drying the ink on the surface of the sheet S, the sheet S is conveyed to the sheet S winding unit 9 instead of the discharge conveyance unit 10.

[0030] The conveyed sheet S is wound around the winding drum of the sheet winding unit 9 that rotates in the forward direction (counterclockwise in the case of Figure 2(b)). That is, the entire sheet S is wound up to the rear end (cut position) by the winding drum. Note that the continuous sheet S on the upstream side in the conveyance direction from the cut position in the sheet S cut by the cutter unit 6 is wound back to the sheet S supply unit 1 so that the front end (cut position) of the sheet S does not remain in the decal unit 2.

[0031] When the recording sequence for the surface of the sheet S ends in this way, the recording sequence for the back surface of the sheet S starts. When this sequence starts, the take-up drum rotates in the direction opposite to the take-up direction (clockwise in Fig. 2(b)). The end of the wound sheet S (the rear end of the sheet S during take-up becomes the front end of the sheet S during feeding) is conveyed to the decal portion 2. In the decal portion 2, the curl of the sheet S is corrected in the direction opposite to when the image is recorded on the surface. This is because the sheet S wound around the take-up drum is wound with the front and back reversed compared to the roll in the sheet S supply portion 1, resulting in an opposite curl.

[0032] After that, the sheet S is conveyed to the recording portion 4 after passing through the skew correction portion 3, and an image is recorded on the back surface of the sheet S. The sheet S on which the image has been recorded passes through the inspection portion 5 and is then cut at the cutter portion 6 at predetermined lengths. Since the image is recorded on both sides of the cut sheet S, information such as the date is not recorded in the information recording portion 7. After that, the sheet S is discharged to the discharge tray 12 of the sorter portion 11 via the drying portion 8 and the discharge conveyance portion 10.

[0033] <Control Unit> Next, with reference to Fig. 3, it is a functional block diagram showing an example of the functions realized by the control unit 13 shown in Fig. 1. Note that the functions shown in Fig. 3 are realized, for example, when the CPU reads and executes a program stored in a memory or the like.

[0034] The control unit 13 includes, as a functional configuration, a pattern formation control unit 21, a pattern reading result acquisition unit 22, an analysis unit 23, and a correction unit 24.

[0035] The pattern formation control unit 21 controls the recording of a test pattern (adjustment pattern) for measuring the deviation of the landing position (adhesion position) of the ink ejected from each nozzle row in each recording head 14. Details of the test pattern will be described later with reference to Fig. 5.

[0036] The pattern reading result acquisition unit 22 acquires the reading result of the test pattern recorded on the sheet S. In the case of this embodiment, the test pattern is read by the reading unit 17 provided in the inspection unit 5. The analysis unit 23 calculates the deviation amount caused by the components of the recording head 14 and manufacturing errors, mounting errors, etc. between the recording heads 14 based on the reading result of the test pattern. In other words, it calculates the deviation amount of the actual ink landing position with respect to the ideal ink landing position.

[0037] The correction unit 24 corrects the deviation of the ink landing position ejected from the nozzles in each recording head 14 based on the deviation amount calculated by the analysis unit 23. The correction unit 24 is provided with a discharge timing control unit 25 that controls the discharge timing of the ink from each nozzle and a shift processing unit 26 that shifts the area of the nozzles used for recording. The above is an explanation of an example of the functions realized by the control unit 13.

[0038] <Configuration of the recording head> Next, the configuration of each recording head 14 in this embodiment will be described with reference to FIG. 4. Since each of the plurality of recording heads 14 has the same configuration, one recording head will be described as an example. In each figure, X and Y indicate directions intersecting each other, and in the case of this embodiment, they are orthogonal. The X direction is the conveyance direction of the sheet S and is the sub-scanning direction. The Y direction is the nozzle array direction and is the main scanning direction.

[0039] In the case of this embodiment, four recording heads 14 are assumed, and each discharges a different type of ink. In the case of this embodiment, four colors, black (K), cyan (C), magenta (M), and yellow (Y), are assumed as the different types of ink.

[0040] Each recording head 14 has, for example, eight chips 31 to 38 made of silicon and having an effective ejection width formed therein, and the eight chips are arranged in the Y direction on a base substrate (support member). In the case of the present embodiment, the chips 31 to 38 are arranged in a staggered pattern. In other words, two chip rows each consisting of four chips arranged in the Y direction are spaced apart in the X direction and are arranged with a shift in the Y direction.

[0041] A plurality of nozzle rows are formed in each of the chips 31 to 38. More specifically, eight nozzle rows (nozzle rows A to H) are arranged in parallel. In each nozzle row, a plurality of nozzles are formed in the nozzle row direction (Y direction). Further, the eight nozzle rows are spaced apart in the X direction.

[0042] Among the chips 31 to 38, the chips adjacent to each other in the Y direction are configured such that they overlap by a predetermined number of nozzles. More specifically, a part of the nozzles in the nozzle rows of the chips adjacent to each other are arranged so as to overlap each other in the Y direction (nozzle arrangement direction). Each of the chips 31 to 38 is provided with, for example, a temperature sensor (not shown) for measuring the temperature of the chip. Each nozzle (ejection port) is provided with, for example, a recording element (heater) composed of a heating resistance element. The recording element is energized and heated to foam the liquid, and the liquid is ejected from the ejection port by the kinetic energy thereof.

[0043] Each recording head 14 has an effective ejection width having a length of about 8 inches, and is configured to have a length substantially matching the length in the short side direction of A4 recording paper. That is, the recording of an image can be completed by one-pass scanning.

[0044] <Test pattern> FIG. 5 shows an example of a test pattern. FIG. 5 also shows the positional relationship between the test pattern, the recording head 14, and the reading unit 17. Note that the test pattern in FIG. 5 is recorded by ink ejected from four recording heads 14, but in FIG. 5, only one recording head 14 is typically illustrated. The reading unit 17 includes a plurality of reading elements 17a arranged with the Y direction as the element array direction. The reading width by the plurality of reading elements 17a is configured to include the recording width of the recording head 14.

[0045] The test pattern includes a plurality of determination patterns 61 to 68. The determination patterns 61 to 68 are head individual analysis patterns for analyzing errors in the components of the recording head 14. Each determination pattern is recorded by a chip with the same lower digit number. For example, the determination pattern 61 is recorded using the nozzles of chip 31. Also, the determination pattern 68 is recorded using the nozzles of chip 38.

[0046] The determination patterns 501 to 504 are for different recording heads 14. The determination pattern 501 is recorded by the black (K) recording head 14, and the determination pattern 502 is recorded by the cyan (C) recording head 14. Similarly, the determination pattern 503 is recorded by the magenta (M) recording head 14, and the determination pattern 504 is recorded by the yellow (Y) recording head 14.

[0047] To summarize the above, for example, the determination pattern 501 / 61 is a pattern recorded using the nozzles of chip 31 of the black (K) recording head 14. The determination pattern 502 / 62 is a pattern recorded using the nozzles of chip 32 of the cyan (C) recording head 14. The determination pattern 503 / 66 is a pattern recorded using the nozzles of chip 36 of the magenta (M) recording head 14. The determination pattern 504 / 68 is a pattern recorded using the nozzles of chip 38 of the yellow (Y) recording head 14. From the reading results of the determination patterns 61 to 68, for each recording head 14, the shift between nozzle rows (X direction), the shift between chips (X direction and Y direction), and the inclination of the chip are measured.

[0048] The test pattern also includes a plurality of determination patterns 505 arranged in the Y direction. The determination pattern 505 is an inter-head analysis pattern for analyzing the error between the recording heads 14. In the case of this embodiment, two determination patterns 505 are provided spaced apart in the Y direction, one being recorded using the nozzles of the chip 31 of each recording head 14, and the other being recorded using the nozzles of the chip 38 of each recording head 14.

[0049] FIG. 6(a) is an enlarged view of the determination pattern 61 within the dotted frame 520 shown in FIG. 5. The determination patterns 62 to 68 have the same configuration.

[0050] The detection bar 506 is used to detect which color pattern it is when analyzing the image read by the reading unit 17. For example, the CPU detects that it is a K pattern if the value of the R channel in the RGB image constituting the detection bar 506 is 10 or less, and detects that it is a C pattern if it is 10 or more and 60 or less. Also, if the value of the G channel is 10 or more and 60 or less, it is detected as an M pattern, and if the value of the B channel is 10 or more and 60 or less, it is detected as a Y pattern.

[0051] The determination pattern 61 also includes a reference mark 507 and a tile pattern 508 used for pattern matching. The tile pattern 508 is detected with reference to the reference mark 507 and is formed at a position a predetermined number of pixels away from the reference mark 507. The tile patterns 508 are all formed of the same pattern and are recorded by different nozzle rows of the same chip. More specifically, it is recorded using a predetermined number of consecutive partial nozzles in each nozzle row arranged on the same chip. Note that these predetermined number of consecutive partial nozzles do not overlap each other in the nozzle arrangement direction in each nozzle row. Also, it is not always necessary to use all the nozzle rows arranged on the same chip for recording the tile pattern 508, and recording may be performed using at least one nozzle row.

[0052] The alphabet attached to the tile pattern 508 indicates the nozzle array used for recording. For example, "H" is a tile pattern recorded using the nozzle array H shown in FIG. 4. Similarly, "A" is a tile pattern recorded using the nozzle array A. The tile pattern 508 includes tile patterns for all nozzle arrays A to H, and includes two tile patterns for the nozzle array H. The two tile patterns of the nozzle array H are located at both ends in the Y direction.

[0053] FIG. 6(b) is an enlarged view of the determination pattern 505 indicated by the dotted frame 530 shown in FIG. 5. The determination pattern 505 includes a detection bar 506 and a reference mark 507, similar to the determination pattern 61 shown in FIG. 6(a). Further, this determination pattern 505 also includes tile patterns 509 to 512 used for pattern matching.

[0054] The tile pattern 509 is recorded using the black (K) recording head 14. The tile pattern 510 is recorded using the cyan (C) recording head 14. The tile pattern 511 is recorded using the magenta (M) recording head 14. The tile pattern 512 is recorded using the yellow (Y) recording head 14.

[0055] Of the two determination patterns 505, one is recorded using the nozzles of the chip 31 of each recording head 14, and the other is recorded using the nozzles of the chip 38 of each recording head 14. That is, among the chips 31 to 38, the chips 31 and 38 located at both ends in the Y direction are used. The tile patterns 509 to 512 are all formed in the same pattern and are recorded using the nozzles of the same nozzle array (in this embodiment, the nozzle array H). That is, the tile patterns 509 to 512 are recorded using the nozzle array arranged at a predetermined position in the chip arranged at the corresponding position within each recording head.

[0056] The tile patterns 508 to 512 are all rectangular patterns, and as an example, as shown in FIG. 7, they are recorded by a random dot pattern.

[0057] All of the tile patterns 508 are arranged in a direction (Y direction) parallel to the element arrangement direction of the reading element 17a in the reading unit 17, as shown in FIG. 5. In other words, they are recorded so as to be arranged in the Y direction. Similarly, the tile patterns 509 to 512 are also arranged in a direction (Y direction) parallel to the element arrangement direction of the reading element 17a in the reading unit 17, as shown in FIG. 5. In other words, they are recorded so as to be arranged in the Y direction.

[0058] The tile patterns 508 to 512 are arranged in a direction (Y direction) parallel to the arrangement of the reading elements 17a of the reading unit 17 of the inspection unit 5. Therefore, even if the size of the read image changes due to a conveyance error, all the tile patterns in the read image change in size in the same way, so the relative change in size between the tile patterns is small. Thereby, the distance between the tile patterns can be measured with high accuracy.

[0059] <Error of the components of the recording head> Next, with reference to FIG. 8, a method for analyzing the deviation amount as an error of the components of the recording head 14 will be described. This deviation amount is obtained based on the relative positional relationship of each tile pattern 508 of the determination patterns 61 to 68. The deviation amounts calculated in the present embodiment are (1) the deviation between nozzle rows (X direction), (2) the inclination of the chip, (3) the deviation between chips (X direction), and (4) the deviation between chips (Y direction).

[0060] All of the tile patterns 508 are recorded with the same pattern. Therefore, pattern matching is performed between the tile patterns within the tile pattern 508, and the distance (number of pixels) between the patterns with the highest correlation among the tile patterns is calculated. Various deviation amounts are calculated from the difference between the number of pixels between the tile patterns at the ideal position and the number of pixels between the calculated tile patterns. Note that a general method may be adopted as the pattern matching method.

[0061] The deviation (in the X direction) between nozzle rows is obtained by calculating the deviation amount of the tile patterns recorded by each of the other nozzle rows with respect to the tile pattern recorded by nozzle row H. The tile patterns 701 to 709 in FIG. 8 correspond to the tile pattern 508 recorded using the nozzles of the same chip, and the tile pattern 710 shows the tile pattern recorded using the nozzles of another adjacent chip.

[0062] When calculating the deviation amount (in the X direction) between the nozzle rows of nozzle row A with respect to nozzle row H, a perpendicular line is drawn from the tile pattern 702 recorded by nozzle row A with respect to the straight line 711 connecting the tile patterns 701 and 709 recorded by nozzle row H. Then, the distance of the perpendicular line is calculated, and the difference from the distance at the ideal position is calculated. Thereby, the deviation amount (in the X direction) between the nozzle rows of nozzle row A with respect to nozzle row H is calculated. Note that the deviation amounts between the nozzle rows of nozzle rows B to G with respect to nozzle row H can be calculated in the same manner. By using the line 711 connecting the tile patterns 701 and 709 recorded by nozzle row H as a reference, the influence of skew during recording pattern reading can be removed.

[0063] The inclination of the chip is obtained by calculating the inclination of the straight line 711 with respect to the element array direction (dashed line) of the reading unit 17. That is, the inclination of the chip is obtained by calculating the inclination of the straight line 711 with respect to the axes of the two-dimensional coordinates of the read image.

[0064] The deviation (in the X direction) between chips is obtained by drawing a perpendicular line from the tile pattern 710 recorded using the nozzles of the adjacent chip with respect to the straight line 711, calculating the distance of the perpendicular line, and calculating the difference from the distance at the ideal position. Thereby, the deviation amount in the X direction between adjacent chips can be calculated.

[0065] Regarding the deviation (in the Y direction) between chips, on the tile pattern 709, draw a straight line 712 perpendicular to the line 711, and connect a perpendicular line from the tile pattern 710 to the line 712. Then, calculate the distance of the perpendicular line and calculate the difference from the distance at the ideal position. Thereby, the deviation amount in the Y direction between adjacent chips can be calculated.

[0066] <Error between recording heads> An analysis of the error occurring between a plurality of recording heads 14 will be described. Here, the positional deviation caused by the inclination in the longitudinal direction of the recording head 14 will be described. The longitudinal direction of the recording head 14 is, in other words, the nozzle array direction and also the chip array direction.

[0067] In the analysis of this error, it is also conceivable to calculate the deviation amount of the position of other recording heads 14 with respect to a specific recording head 14 (for example, the recording head for black ink) as a reference. However, with this method, the error of the reference recording head itself can have an impact. Although it is possible to improve the mounting accuracy of the reference recording head, it becomes a cost factor. This point will be described with reference to FIGS. 9(a) to 9(c).

[0068] In FIGS. 9(a) to 9(c), a black (K) recording head 14K, a cyan (C) recording head 14C, a magenta (M) recording head 14M, a yellow (Y) recording head 14Y, and a reading unit 17 are illustrated.

[0069] FIG. 9(a) is an example where it may be determined that the recording head 14K is the most perpendicular to the conveyance direction of the sheet S. That is, the longitudinal direction of the recording head 14K is directed substantially in the Y direction. In this case, the recording position deviation caused by the inclination of each recording head 14C to 14Y may be corrected with the recording head 14K as a reference.

[0070] On the other hand, as shown in FIGS. 9(b) and 9(c), the recording head 14K may not be the most perpendicular to the conveyance direction of the sheet S. Even in this case, with the recording head 14K as a reference, although the deviation of the recording positions between different colors can be reduced, the entire recorded image with respect to the sheet S will be inclined. The quality of the output product may be lowered.

[0071] Therefore, in the present embodiment, by using two determination patterns 505, the error between the recording heads 14 is analyzed using a method that does not use a specific recording head 14 as a reference. More specifically, based on the relative positional relationship between the two determination patterns 505, the amount of deviation in the X direction between the recording heads 14 due to the inclination of the recording head 14 is calculated.

[0072] FIG. 10(a) shows the left determination pattern recorded using the nozzles of the chip 31 among the two determination patterns 505, and FIG. 10(b) shows the right determination pattern recorded using the nozzles of the chip 38. For the sake of convenience of explanation, for the left determination pattern, the tile patterns 509 to 512 in FIG. 6(b) are represented as tile patterns 509a to 512a, and for the right determination pattern, the tile patterns 509 to 512 in FIG. 6(b) are represented as tile patterns 509b to 512b.

[0073] In the present embodiment, the amount of deviation between the recording heads 14 is specified as the amount of deviation with respect to the reference direction. Therefore, first, the reference direction is set. In the present embodiment, as an example, the reference direction is determined by averaging the nozzle array directions obtained from the tile patterns 509 and 510 recorded by the black (K) recording head 14K and the cyan (C) recording head 14C. Since the recording patterns using black ink and cyan ink have relatively high densities, higher recognition accuracy can be obtained.

[0074] FIG. 11(a) and FIG. 11(b) are explanatory diagrams of a method for specifying the longitudinal direction of the recording heads 14K and 14C. As shown in FIG. 11(a), the longitudinal direction of the recording head 14K is specified by a straight line 509c connecting the tile patterns 509a and 509b. The straight line 509c is specified, for example, as a straight line passing through the centroids of the tile patterns 509a and 509b. Then, the intersection angle α between the straight line 513 indicating the element array direction of the reading unit 17 and the straight line 509c is calculated. Similarly, as shown in FIG. 11(b), the longitudinal direction of the recording head 14C is specified by a straight line 510c connecting the tile patterns 510a and 510b. Then, the intersection angle β between the straight line 513 and the straight line 510c is calculated. With respect to the straight line 513, a direction intersecting at the average value γ (= (α + (-β)) / 2) of the intersection angles α and β is determined as the reference direction. FIG. 11(c) illustrates a straight line Le indicating the reference direction. By determining the reference direction from the longitudinal directions of the plurality of recording heads 14 in this way, even if there is an attachment error in the reading unit 17, a more appropriate reference direction can be set.

[0075] Next, the displacement in the X direction due to the inclination of the longitudinal direction of each recording head 14 with respect to the reference direction is calculated. FIGS. 12(a) to 12(d) are explanatory diagrams thereof. In the present embodiment, for each recording head, the distance between a straight line in the reference direction passing through one of the two tile patterns and the other tile pattern is calculated, and this is taken as the displacement amount. This will be specifically described.

[0076] FIG. 12(a) shows an example of calculating the displacement of the recording head 14K. A straight line 509e is drawn from the tile pattern 509a in the reference direction. The straight line 509e is the straight line Le (corresponding to FIG. 11(c)) passing through the tile pattern 509a. A perpendicular line 509f is drawn from the tile pattern 509b to the straight line 509e, and the length thereof is taken as the displacement amount due to the inclination of the recording head 14K. The length of the perpendicular line 509f can be the length from the centroid of the tile pattern 509b to the straight line 509e.

[0077] The same applies to the other recording heads 14. FIG. 12(b) shows an example of calculating the displacement of the recording head 14C. A straight line 510e is drawn from the tile pattern 510a in the reference direction. A perpendicular line 510f is drawn from the tile pattern 510b to the straight line 510e, and the length thereof is taken as the displacement amount due to the inclination of the recording head 14C. FIG. 12(c) shows an example of calculating the displacement of the recording head 14M. A straight line 511e is drawn from the tile pattern 511a in the reference direction. A perpendicular line 511f is drawn from the tile pattern 511b to the straight line 511e, and the length thereof is taken as the displacement amount due to the inclination of the recording head 14M. FIG. 12(d) shows an example of calculating the displacement of the recording head 14Y. A straight line 512e is drawn from the tile pattern 512a in the reference direction. A perpendicular line 512f is drawn from the tile pattern 512b to the straight line 512e, and the length thereof is taken as the displacement amount due to the inclination of the recording head 14Y.

[0078] The displacement amount specified by the lengths of the perpendicular lines 509f to 512f corresponds to the displacement amount at the other end when the displacement amount at one end in the Y direction of the recording head 14 is set to 0. In the case of this embodiment, the correction amount is set for each chip (chip unit). Each recording head 14 has eight chips up to chips 31 to 38. It can be assumed that there is no displacement at chip 31 and there is a displacement corresponding to the lengths of the perpendicular lines 509f to 512f at chip 38. For the displacement amounts of chips 32 to 37, the displacement amount of chip 38 is proportionally distributed according to these positions in the Y direction. For example, if the displacement amount of chip 38 is Xd, then for chip 32: Xd·1 / 7, for chip 33: Xd·2 / 7, for chip 34: Xd·3 / 7, for chip 35: Xd·4 / 7, for chip 36: Xd·5 / 7, for chip 37: Xd·6 / 7. The correction is performed by adding these respective displacement amounts to the displacement (in the X direction) between the chips described above.

[0079] Next, with reference to FIG. 13, a method for calculating the displacement in the Y direction between a plurality of recording heads 14 due to the inclination of the recording heads 14 will be described. As an example, an example of obtaining this displacement based on the relative positional relationship of the tile patterns 509a to 512a shown in FIG. 10(a) will be described.

[0080] First, select a reference recording head 14. Here, the case where the recording head 14K is used as the reference will be described, but other recording heads 14C to 14Y may also be used. As shown in FIG. 13, draw a straight line 509e (the same as in FIG. 12(a)) that passes through the tile pattern 509a and points in the reference direction. All of these correspond to the recording head 14K. Draw a straight line 509e' that is orthogonal to the straight line 509e. The straight line 509e' may be a straight line that passes through the center of the tile pattern 509a.

[0081] Draw a perpendicular line 510g from the tile pattern 510a to the straight line 509e'. The difference between the ideal Y-direction distance between the recording head 14K and the recording head 14C and the length of the perpendicular line 510g is defined as the Y-direction displacement amount caused by the inclination of the recording head 14C.

[0082] Similarly, draw a perpendicular line 511g from the tile pattern 511a to the straight line 509e'. The difference between the ideal Y-direction distance between the recording head 14K and the recording head 14M and the length of the perpendicular line 511g is defined as the Y-direction displacement amount caused by the inclination of the recording head 14M. Also, draw a perpendicular line 512g from the tile pattern 512a to the straight line 509e'. The difference between the ideal Y-direction distance between the recording head 14K and the recording head 14Y and the length of the perpendicular line 512g is defined as the Y-direction displacement amount caused by the inclination of the recording head 14Y.

[0083] The correction amount is set for each head (in head units), and the correction is performed by adding these respective displacement amounts to the displacement (in the Y direction) between the chips described above. That is, the displacement amount calculated for the recording head 14C is added to the displacement (in the Y direction) between the chips of the recording head 14C. Similarly, the displacement amount calculated for the recording head 14M is added to the displacement (in the Y direction) between the chips of the recording head 14M, and the displacement amount calculated for the recording head 14Y is added to the displacement (in the Y direction) between the chips of the recording head 14Y.

[0084] In the example of FIG. 13, the tile patterns 509a to 512a shown in FIG. 10(a) are used. However, the tile patterns 509b to 512b shown in FIG. 10(b) may also be used. Further, the amount of misalignment may be obtained from each tile pattern in FIGS. 10(a) and 10(b), and the average value of the two may be used as the final amount of misalignment.

[0085] <Correction example> Next, a method for correcting the deviation of the recording position (landing position) of the ink ejected from the nozzles in each recording head 14 based on the calculated deviation amount will be described. The correction for the deviation between nozzle rows (in the X direction) is performed by changing the ejection timing of the ink from each nozzle based on the deviation amount with respect to the nozzle row H. Thereby, the deviation of the landing position of the ink from each nozzle row with respect to the nozzle row H is corrected.

[0086] The correction for the inclination of the chip is performed, for example, by shifting the recording data (dot data) in the conveyance direction according to the inclination.

[0087] The correction for the deviation between chips (in the X direction) is performed by changing the ejection timing of the other chips 32 to 38 with respect to the chip 31. Specifically, the ejection timing of all the nozzle rows of the chip 32 is uniformly corrected by an amount based on the deviation amount between the chips with respect to the chip 31. The chip 33 performs a correction by adding the correction amount for the deviation with respect to the chip 32 and the correction amount of the chip 32 with respect to the chip 31. The same correction is performed for the chips 33 to 38. As described above, the correction amount for the deviation between chips (in the X direction) includes the amount of positional deviation in the X direction between the recording heads 14.

[0088] Correction for the deviation between chips (in the Y direction) is performed by shifting the used nozzle area. Here, FIG. 14 shows an enlarged view of the overlapping portion between chips. In an 8-column nozzle array, for example, nozzles are arranged at a resolution of 1200 dpi each. Also, between column A / column C / column E / column G and column B / column D / column F / column H, the nozzle arrays are arranged with a 2400 dpi shift. Areas 901 and 902 are the arrangement areas for adjustment nozzles (spare nozzles) for nozzle shifting.

[0089] When the position of chip 32 relative to chip 31 is shifted by +2400 dpi, as shown in FIG. 15, the relationship between the ejection port and the recording data is changed. Specifically, the recording data for all columns of chip 32 is shifted by 1 nozzle (1200 dpi) to the - side, and further, the recording data of column A and column B, column C and column D, column E and column F, column G and column H are swapped respectively. Thereby, correction can be performed at 2400 dpi intervals.

[0090] Also, when the position of chip 32 relative to chip 31 is shifted by +1200 dpi, as shown in FIG. 16, the relationship between the ejection port and the recording data is changed. Specifically, the recording data for all columns of chip 32 is shifted by 1 nozzle (1200 dpi) to the - side. Thereby, correction can be performed at 1200 dpi intervals.

[0091] Correction for the deviation between chips (in the Y direction) is also the same as the correction for the deviation between chips (in the X direction), that is, all chips are aligned with respect to chip 31. Specifically, the deviation amount between each adjacent chip is calculated, and the used nozzles of chip 32 are shifted with respect to chip 31. Chip 33 performs correction by adding the correction amount of chip 32 with respect to chip 31 in addition to the correction for the deviation amount with respect to chip 32. Chips 33 to 38 are corrected in the same way. As described above, the correction amount for the deviation between chips (in the Y direction) includes the amount of positional deviation in the Y direction between the recording heads 14.

[0092] As described above, according to the present embodiment, it is possible to analyze the reading result of the test pattern and correct the components of the recording head 14 and the deviation occurring between the plurality of recording heads 14 based on the relative positional relationship of the plurality of tile patterns read. Regarding the correction of the inclination between the recording heads 14, the average of the inclinations of the recording head 14K and the recording head 14C was used to determine the reference direction. Since no specific recording head 14 is used as a reference, precise position adjustment is not required for any of the recording heads 14.

[0093] Generally, it is a well-known fact that physical position adjustment of the recording head is important in terms of recording quality. In addition, a recording apparatus in which the consumed recording head 14 can be replaced has also been proposed. For these reasons, a recording apparatus having a mechanism for correcting the mounting position of the recording head has also been proposed. However, even if a correction mechanism is provided, the recording head may be inclined, and as a result of the correction mechanism having the same accuracy, the inclination often occurs with a certain variation. Therefore, by using the average of the inclinations of the plurality of recording heads 14 as in the present embodiment, it is possible to more accurately correct the deviation of the recording position caused by the inclination.

[0094] In addition, when a specific recording head is used as a reference, if the physical inclination of the reference recording head is large, local image quality degradation may occur as a result of the correction. By using the average of the inclinations of the plurality of recording heads 14 as in the present embodiment, the occurrence of such local image quality degradation can also be suppressed.

[0095] <Second Embodiment> In the first embodiment, as shown in FIGS. 11(a) to 11(c), the average value of the intersection angles between the longitudinal directions of the recording heads 14K and 14C and the element array direction of the reading unit 17 was used to determine the reference direction. However, the nozzle array direction used to determine the reference direction is not limited to the combination of the recording heads 14K and 14C. For example, a combination of two recording heads 14 at the most upstream and the most downstream in the X direction (recording heads 14K and 14Y in the example of FIG. 9(a)) may be used. Also, a combination of recording heads 14 located in the middle in the X direction (recording heads 14C and 14M in the example of FIG. 9(a)) may be used.

[0096] Also, the number of recording heads 14 used to determine the reference direction is not limited to two, and may be three or more. Although the algorithm for calculating the reference becomes more complicated than when using two recording heads 14, the reliability of the reference direction can be improved.

[0097] Also, when determining the reference direction, after specifying the longitudinal directions of a plurality of recording heads 14, the ones with the largest and the smallest intersection angles with the element array direction of the reading unit 17 may be excluded and the average value of the intersection angles may be obtained. Specifically, for example, by the method illustrated in FIGS. 11(a) and 11(b), the longitudinal directions of the four recording heads 14K to 14Y are specified, and the intersection angles with the element array direction are specified. When the intersection angles (absolute values) between the longitudinal directions of the recording heads 14K and 14Y and the element array direction are the maximum value and the minimum value, the reference direction is determined by the average value of the intersection angles between the longitudinal directions of the recording heads 14C and 14M and the element array direction.

[0098] <Third Embodiment> In the first embodiment, the recording apparatus 20 including four recording heads 14 corresponding to four types of ink was exemplified, but the present invention is also applicable to a recording apparatus including five or more recording heads 14 corresponding to five or more types of ink. Also, depending on the type of ink, a transparent liquid, white ink, or light ink may be used. The transparent liquid is, for example, a reaction liquid that improves the fixing property of other inks.

[0099] In determining the reference direction shown in FIGS. 11(a) to 11(c), the longitudinal direction of the recording head for the transparent liquid may be excluded. That is, the reference direction is determined based on the longitudinal direction of the recording head other than the recording head for the transparent liquid. Also, for the recording head for the transparent liquid, correction of the recording position deviation may not be necessary. This is because the transparent liquid is not visualized on the sheet S.

[0100] Based on the same idea, when the sheet S is white, or when the background color of the image is white, in determining the reference direction shown in FIGS. 11(a) to 11(c), the longitudinal direction of the recording head for the white ink may be excluded. Also, correction of the recording position deviation may not be necessary.

[0101] Based on the same idea, in determining the reference direction shown in FIGS. 11(a) to 11(c), the longitudinal direction of the recording head for the light ink may be excluded. Also, correction of the recording position deviation may not be necessary. The light ink is considered to have an unobtrusive recording position deviation on the image.

[0102] <Fourth Embodiment> In the first embodiment, an example was described in which, out of the two determination patterns 505, one is recorded using the nozzles of the chip 31 of each recording head 14, and the other is recorded using the nozzles of the chip 38 of each recording head 14. Since these chips 31 and 38 are most separated in the Y direction, there is an advantage that the crossing angles described in FIGS. 11(a) and 11(b) are easy to analyze. On the other hand, the determination pattern 505 may be recorded using other chips 32 to 36.

[0103] Also, the test pattern may include three or more determination patterns 505. In this case, the straight line 509c illustrated in FIG. 11(a) may be an approximate straight line for three or more tile patterns 509.

[0104] <Fifth Embodiment> The reference direction may be the element array direction of the reading unit 17. Although it is affected by the mounting accuracy of the reading unit 17, it is possible to correct the positional deviation caused by the inclination of the recording head 14 relatively simply. FIGS. 17(a) to 17(d) are explanatory diagrams of the present embodiment, showing an example of calculating the positional deviation in the X direction caused by the inclination in the longitudinal direction of each recording head 14. The straight lines 513a to 513d indicate the element array direction of the reading unit 17, which is the same as the straight line 513 shown in FIGS. 11(a) and 11(b). In the present embodiment, the straight line 513 is a straight line indicating the reference direction.

[0105] FIG. 17(a) shows an example of calculating the positional deviation of the recording head 14K. A straight line 513a is drawn from the tile pattern 509a in the reference direction. A perpendicular line 509f' is drawn from the tile pattern 509b to the straight line 513a, and its length is taken as the amount of positional deviation caused by the inclination of the recording head 14K. The length of the perpendicular line 509f' can be the length from the centroid of the tile pattern 509b to the straight line 513a.

[0106] The same applies to the other recording heads 14. FIG. 17(b) shows an example of calculating the positional deviation of the recording head 14C. A straight line 513b is drawn from the tile pattern 510a in the reference direction. A perpendicular line 510f' is drawn from the tile pattern 510b to the straight line 513b, and its length is taken as the amount of positional deviation caused by the inclination of the recording head 14C. FIG. 17(c) shows an example of calculating the positional deviation of the recording head 14M. A straight line 513c is drawn from the tile pattern 511a in the reference direction. A perpendicular line 511f' is drawn from the tile pattern 511b to the straight line 513c, and its length is taken as the amount of positional deviation caused by the inclination of the recording head 14M. FIG. 17(d) shows an example of calculating the positional deviation of the recording head 14Y. A straight line 513d is drawn from the tile pattern 512a in the reference direction. A perpendicular line 512f' is drawn from the tile pattern 512b to the straight line 513d, and its length is taken as the amount of positional deviation caused by the inclination of the recording head 14Y.

[0107] The amount of displacement specified by the lengths of the perpendicular lines 509f’ to 512f’ corresponds to the amount of displacement at the other end of the recording head 14 when the amount of displacement at one end in the Y direction of the recording head 14 is set to zero. Similar to the first embodiment, the correction amount is set on a chip-by-chip basis. It can be assumed that there is no displacement in chip 31 and that there is a displacement corresponding to the lengths of the perpendicular lines 509f’ to 512f’ in chip 38. For the amounts of displacement of chips 32 to 37, the amount of displacement of chip 38 is proportionally distributed according to these positions in the Y direction.

[0108] Next, a method for calculating the displacement in the Y direction between a plurality of recording heads 14 due to the inclination of the recording head 14 is the same as that of the first embodiment illustrated in FIG. 13. Briefly described, instead of the straight line 509e pointing in the reference direction, a straight line 513a passing through the tile pattern 509a is drawn, and a straight line orthogonal to the straight line 513a is drawn (designated as the straight line 513a’). From the tile patterns 510a to 512a, perpendicular lines are respectively drawn to the straight line 513a’, and the difference between the length of the perpendicular line and the ideal distance in the Y direction between the recording head 14K and the other recording heads 14C to 14Y is defined as the amount of displacement in the Y direction. The setting of the correction amount is also the same as that of the first embodiment, which is performed on a head-by-head basis, and the correction is performed by adding these amounts of displacement to the displacement (in the Y direction) between the chips described above.

[0109] By setting the reference direction to the element array direction of the reading unit 17 in this way, it becomes necessary to finely adjust the physical inclination of the reading unit 17 during the manufacture of the recording apparatus 20. Also, generally speaking, compared with the recording head 14, the replacement frequency of the reading unit 17 is extremely low. By setting the element array direction as the reference direction, even when the recording head is replaced, it is considered that strict inclination adjustment is not required for the reinstallation of the recording head itself. Therefore, it is possible to reduce the labor of adjustment when the head is replaced by the user or the service technician.

[0110] It should be noted that the concept of this embodiment can also be applied to the analysis of the displacement (in the X direction) between chips with the element array direction as the reference. FIG. 18 shows an example thereof.

[0111] In FIG. 18, the tile patterns 501a to 501g correspond to one of the tile patterns 508 of the determination patterns 61 to 68 in FIG. 5. Specifically, the tile pattern 501a is included in the determination pattern 61, and the tile pattern 501b is included in the determination pattern 62. The same applies to the tile patterns 501c to 501g. Also, the tile patterns 501a to 501g respectively correspond to the tile pattern of the rightmost "H" among the tile patterns 508 shown in FIG. 6(a).

[0112] In the example of FIG. 18, the chip 38 is used as a reference, and a straight line 513 passing through the tile pattern 501h corresponding to the chip 38 is drawn. The straight line 513 is a straight line directed in the element array direction of the reading unit 17. The straight line 513 may be a straight line passing through the centroid of the tile pattern 501h.

[0113] Perpendicular lines 501i to 501o are drawn from each of the tile patterns 501a to 501g to the straight line 513, and the lengths of the perpendicular lines 501i to 501o are taken as the deviation amounts (X direction) of the corresponding chips. For example, the length of the perpendicular line 501i is taken as the deviation amount (X direction) between the chips of the chip 31.

[0114] By correcting the deviation (X direction) between the chips, it is directly connected to correcting the inclination of one recording head 14 as it is, and it is possible to further simplify the correction algorithm. In a recording apparatus that requires high-speed recording, it is also possible to do so.

[0115] <Sixth Embodiment> Whether to determine the reference direction from the longitudinal direction of the plurality of recording heads 14 as in the first embodiment (referred to as the head reference method) or to use the element array direction of the reading unit 17 as in the fifth embodiment (referred to as the element array reference method) may be selectable by the user. In either the head reference method or the element array reference method, the recorded image after correction may be inclined. By making the method of determining the reference direction selectable by the user, an image according to the user's preference can be provided.

[0116] FIG. 19 is a flowchart showing a processing example of the present embodiment, which is executed by the control unit 13 or the external device 16 (such as a host computer). This flowchart is executed, for example, when the recording head 14 is replaced or when the user gives an instruction.

[0117] In S1, the test pattern of FIG. 5 is recorded on the sheet S by the recording heads 14K to 14Y. In S2, the recorded test pattern is read by the reading unit 17. In S3, the reading result of S2 is analyzed by the head reference method, and in S4, the correction amount of the recording position deviation based on the analysis result of S3 is calculated. In S5, the reading result of S2 is analyzed by the element array reference method, and in S6, the correction amount of the recording position deviation based on the analysis result of S5 is calculated.

[0118] In S7, two types of sample images are recorded on the sheet S by the recording heads 14K to 14Y. The two types of sample images are the same image but have different correction amounts for the recording position deviation. One is the recorded image using the correction amount calculated in S4, and the other is the recorded image using the correction amount calculated in S6.

[0119] In S8, a selection by the user is received. This selection is a selection of which of the two types of images recorded in S7 to select, and is a user selection of whether to use the head reference method or the element array reference method for determining the reference direction. In S9, according to the selection in S8, either the correction amount calculated in S4 or S6 is set as the correction amount to be used for future recording.

[0120] According to the processing example of FIG. 19, the user of the recording apparatus 20 can compare two types of images with different ways of determining the reference direction and select one of them, so that the user's preference can be reflected in the correction. In the processing example of FIG. 19, after presenting two types of images to the user, the user can select whether to use the head reference method or the element array reference method for determining the reference direction. However, the presentation of the two types of images may be omitted, and the user may simply select one of the methods.

[0121] <Seventh Embodiment> In the above-described embodiment, the roll-shaped continuous sheet S was exemplified as the recording medium. However, a cut sheet may be used as the recording medium. Further, the roll-shaped continuous sheet S may be wound up as it is without being cut.

[0122] Further, in the above-described embodiment, the positions of the plurality of recording heads 14 are fixed positions, and the sheet S is moved relative to the plurality of recording heads 14 by the transport mechanism. However, an image may be recorded on the sheet S while the recording head 14 moves relative to the sheet S. That is, it is sufficient to provide a mechanism for relatively moving the plurality of recording heads and the recording medium in the X direction. <Other Embodiments> The present invention can also be realized by supplying a program that realizes one or more functions of the above-described embodiment to a system or device via a network or a storage medium, and causing one or more processors in the computer of the system or device to read and execute the program. Further, it can also be realized by a circuit (for example, ASIC) that realizes one or more functions.

[0123] <Summary of Embodiments> The above-described embodiment discloses the inventions of the following respective items.

[0124] Item 1. A plurality of recording heads arranged in a first direction, Moving means for relatively moving the plurality of recording heads and the recording medium in the first direction, Reading means for reading a test pattern recorded on the recording medium by the plurality of recording heads, Analyzing means for analyzing the test pattern read by the reading means, Correction means for correcting a deviation in the recording positions of the plurality of recording heads based on the result of the analysis by the analyzing means, and Each recording head has a plurality of chips arranged in the longitudinal direction of the recording head intersecting the first direction, and each chip is a recording device having a plurality of nozzles arranged in the longitudinal direction, The test pattern includes a plurality of determination patterns arranged in a second direction intersecting the first direction. Each determination pattern includes a pattern recorded by each recording head. Based on the plurality of determination patterns, the analysis means analyzes a positional shift caused by the inclination in the longitudinal direction of each recording head. Based on the positional shift analyzed by the analysis means, the correction means corrects a shift in the recording position. A recording apparatus characterized by the above.

[0125] Item 2. The recording apparatus according to Item 1, wherein the analysis means analyzes a positional shift between the longitudinal direction of each recording head specified from the plurality of determination patterns and a reference direction. A recording apparatus characterized by the above.

[0126] Item 3. The recording apparatus according to Item 2, wherein the reference direction is determined from the longitudinal directions of at least two recording heads specified from the plurality of determination patterns. A recording apparatus characterized by the above.

[0127] Item 4. The recording apparatus according to Item 3, wherein the plurality of recording heads include a first recording head that discharges black ink and a second recording head that discharges cyan ink. The reference direction is determined from the longitudinal directions of the first recording head and the second recording head specified from the plurality of determination patterns. A recording apparatus characterized by the above.

[0128] Item 5. The recording apparatus according to Item 3, wherein the reading means includes a plurality of reading elements arranged in an element array direction intersecting the first direction. At least two of the longitudinal directions used to determine the reference direction are longitudinal directions among the longitudinal directions of the plurality of recording heads specified from the plurality of determination patterns, excluding the longitudinal direction with the largest deviation from the element array direction and the longitudinal direction with the smallest deviation from the element array direction. A recording apparatus characterized by this.

[0129] Item 6. The recording apparatus according to item 3, The plurality of recording heads include a first recording head that discharges a transparent liquid, The reference direction is determined from the longitudinal directions of the recording heads other than the first recording head specified from the plurality of determination patterns. A recording apparatus characterized by this.

[0130] Item 7. The recording apparatus according to item 2, The reading means includes a plurality of reading elements arranged in an element array direction intersecting the first direction, The reference direction is the element array direction. A recording apparatus characterized by this.

[0131] Item 8. The recording apparatus according to item 2, The reading means includes a plurality of reading elements arranged in an element array direction intersecting the first direction, It is possible to select either the correction of the deviation of the recording position by the correction means when the reference direction is the first reference direction or the correction when the reference direction is the second reference direction. The first reference direction is determined from the longitudinal directions of at least two recording heads specified from the plurality of determination patterns. The second reference direction is the element array direction. A recording apparatus characterized by this.

[0132] Item 9. The recording apparatus according to any one of items 2 to 8, The plurality of determination patterns are two determination patterns recorded by nozzles of each chip located at both ends in the longitudinal direction of the plurality of recording heads. A recording apparatus characterized by the above.

[0133] Item 10. The recording apparatus according to Item 9, wherein the analysis means for each of the recording heads, calculates a distance between a straight line passing through one of the two patterns corresponding to the recording head and pointing in the reference direction and the other of the two patterns. A recording apparatus characterized by the above.

[0134] Item 11. The recording apparatus according to any one of Items 1 to 10, wherein each pattern of the determination patterns is a tile pattern, and in each determination pattern, the tile patterns corresponding to the respective recording heads are recorded so as to be arranged in the second direction. A recording apparatus characterized by the above.

[0135] Item 12. The recording apparatus according to any one of Items 1 to 11, wherein the plurality of chips are arranged in a staggered pattern. A recording apparatus characterized by the above.

[0136] Item 13. The recording apparatus according to any one of Items 1 to 12, wherein the correction means sets a correction amount for positional deviation caused by the inclination in the longitudinal direction of each recording head for each of the chips. A recording apparatus characterized by the above.

[0137] Item 14. The recording apparatus according to any one of Items 1 to 13, wherein each recording head is a full-line head. A recording apparatus characterized by the following.

[0138] Item 15. A plurality of recording heads arranged in a first direction, Moving means for relatively moving the plurality of recording heads and a recording medium in the first direction, Reading means for reading a test pattern recorded on a recording medium by the plurality of recording heads, comprising: Each recording head has a plurality of chips arranged in the longitudinal direction of the recording head intersecting the first direction, and each chip has a plurality of nozzles arranged in the longitudinal direction. A control method for a recording apparatus, An analysis step of analyzing a test pattern read by the reading means, Based on the result of the analysis in the analysis step, a correction step of correcting a deviation in the recording position of the plurality of recording heads, comprising: The test pattern includes a plurality of determination patterns arranged in a second direction intersecting the first direction, Each determination pattern includes a pattern recorded by each recording head, In the analysis step, based on the plurality of determination patterns, a positional deviation caused by the inclination of each recording head in the longitudinal direction is analyzed, In the correction step, the deviation in the recording position is corrected based on the positional deviation analyzed in the analysis step, A control method characterized by the following.

[0139] The invention is not limited to the above embodiments, and various changes and modifications are possible without departing from the spirit and scope of the invention. Therefore, claims are attached to publicly disclose the scope of the invention.

Explanation of Reference Numerals

[0140] 14 Recording head, 17 Reading unit, 20 Recording apparatus

Claims

1. A plurality of recording heads arranged in a first direction, Moving means for relatively moving the plurality of recording heads and a recording medium in the first direction, Reading means for reading a test pattern recorded on a recording medium by the plurality of recording heads, Analyzing means for analyzing the test pattern read by the reading means, Correction means for correcting a deviation in the recording position of the plurality of recording heads based on the result of analysis by the analysis means, comprising: Each recording head has a plurality of chips arranged in the longitudinal direction of the recording head intersecting the first direction, and each chip has a plurality of nozzles arranged in the longitudinal direction, and is a recording device, The test pattern includes a plurality of determination patterns arranged in a second direction intersecting the first direction, Each determination pattern includes a pattern recorded by each recording head, The analysis means analyzes a positional deviation caused by an inclination in the longitudinal direction of each recording head based on the plurality of determination patterns, The correction means corrects a deviation in the recording position based on the positional deviation analyzed by the analysis means, A recording device characterized by the above.

2. The recording device according to claim 1, The analysis means, Analyzes a positional deviation between the longitudinal direction of each recording head specified from the plurality of determination patterns and a reference direction, A recording device characterized by the above.

3. The recording device according to claim 2, The reference direction is, Determined from the longitudinal directions of at least two recording heads specified from the plurality of determination patterns, A recording device characterized by the above.

4. The recording device according to claim 3, The plurality of recording heads include a first recording head that discharges black ink and a second recording head that discharges cyan ink, The reference direction is determined from the longitudinal directions of the first recording head and the second recording head specified from the plurality of determination patterns, A recording device characterized by the above.

5. The recording device according to claim 3, The reading means includes a plurality of reading elements arranged in an element array direction intersecting the first direction, At least two of the longitudinal directions used to determine the reference direction are the longitudinal directions of the plurality of recording heads specified from the plurality of determination patterns, excluding the longitudinal direction with the largest deviation from the element array direction and the longitudinal direction with the smallest deviation from the element array direction. A recording apparatus characterized by the above.

6. The recording apparatus according to claim 3, wherein the plurality of recording heads includes a first recording head that discharges a transparent liquid, and the reference direction is determined from the longitudinal direction of the recording heads other than the first recording head, which is specified from the plurality of determination patterns. A recording apparatus characterized by the above.

7. The recording apparatus according to claim 2, wherein the reading means includes a plurality of reading elements arranged in an element array direction intersecting the first direction, and the reference direction is the element array direction. A recording apparatus characterized by the above.

8. The recording apparatus according to claim 2, wherein the reading means includes a plurality of reading elements arranged in an element array direction intersecting the first direction, and it is possible to select either the correction of the deviation of the recording position by the correction means when the reference direction is the first reference direction or the correction when the second reference direction is used, wherein the first reference direction is determined from the longitudinal directions of at least two recording heads specified from the plurality of determination patterns, and the second reference direction is the element array direction. A recording apparatus characterized by the above.

9. The recording apparatus according to claim 2, wherein the plurality of determination patterns are two determination patterns recorded by nozzles of respective chips located at both ends in the longitudinal direction of the plurality of recording heads. A recording apparatus characterized by the above.

10. The recording apparatus according to claim 9, wherein the analysis means calculates, for each recording head, the distance between a straight line passing through one of the two patterns corresponding to the recording head and pointing in the reference direction and the other of the two patterns. A recording apparatus characterized by the above.

11. The recording apparatus according to claim 1, wherein each pattern of the determination patterns is a tile pattern, and in each determination pattern, the tile patterns corresponding to the respective recording heads are recorded so as to be arranged in the second direction. A recording apparatus characterized by the above.

12. The recording apparatus according to claim 1, wherein the plurality of chips are arranged in a staggered pattern. A recording apparatus characterized by the above.

13. The recording apparatus according to claim 1, wherein the correction means sets, for each chip, a correction amount for the positional deviation caused by the inclination in the longitudinal direction of each recording head. A recording apparatus characterized by the above.

14. The recording apparatus according to claim 1, Each recording head is a full-line head. A recording apparatus characterized by this.

15. A plurality of recording heads arranged in a first direction, Moving means for relatively moving the plurality of recording heads and a recording medium in the first direction, Reading means for reading a test pattern recorded on the recording medium by the plurality of recording heads, and comprising: Each recording head has a plurality of chips arranged in the longitudinal direction of the recording head intersecting the first direction, and each chip has a plurality of nozzles arranged in the longitudinal direction. A control method for a recording apparatus, An analysis step of analyzing the test pattern read by the reading means, A correction step of correcting a deviation in the recording positions of the plurality of recording heads based on the result of the analysis in the analysis step, and comprising: The test pattern includes a plurality of determination patterns arranged in a second direction intersecting the first direction, Each determination pattern includes a pattern recorded by each recording head, In the analysis step, based on the plurality of determination patterns, a positional deviation caused by the inclination of each recording head in the longitudinal direction is analyzed, In the correction step, the deviation in the recording position is corrected based on the positional deviation analyzed in the analysis step. A control method characterized by this.

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