JP5527996B2 - Recording method and recording apparatus - Google Patents

Description

  The present invention relates to a recording method and a recording apparatus, and more particularly to formation of a recording density detection pattern by a recording head.

  Conventionally, it is known to record a density detection pattern in order to know the recording density characteristics in a recording apparatus. For example, in an ink jet recording apparatus, the amount of ink ejected from nozzles may vary from recording head to recording head or from nozzle to nozzle due to individual differences in recording heads. For this reason, a predetermined pattern is recorded by ejecting ink from the recording head in advance, and the ejection amount for each recording head or each nozzle is detected based on the density measured for the pattern.

  Japanese Patent Application Laid-Open No. H10-228707 describes that a dot density pattern of 25% is recorded on a recording head of each color ink in an ink jet recording apparatus. Then, a γ correction table is selected on the basis of the density measurement result of the pattern recorded in this way, and γ correction is performed on the ink data of each color, thereby suppressing variations in ejection amount for each recording head.

  Thus, conventionally, a recording characteristic of a recording head or the like related to the recording is corrected by recording a predetermined pattern and measuring its density.

Japanese Patent Laid-Open No. 10-278360

  However, in the pattern formed by arranging dots as described in Patent Document 1, when the dots are recorded out of their original positions for some reason, the measured density may be lowered. That is, the measured density of the pattern as a whole decreases regardless of the difference in recording characteristics such as the ejection amount that is to be detected based on the measured density. If the density measured as a whole decreases as described above, it is impossible to accurately know the recording characteristics when the pattern is recorded.

  For example, when recording a single pattern by carrying the recording medium a plurality of times, if the carry amount is different from the regular carry amount, the dot recording position is shifted as described above. Specifically, the pattern for measurement is recorded by a so-called multi-pass method in which a recording medium is transported between a plurality of scans (passes) of the recording head and the recording medium is conveyed between these scans to complete recording of a predetermined area. There is. In this case, when the dot recorded in the first pass is used as a reference, dots recorded in a pass further away from the reference pass are recorded in positions separated in the transport direction. As a result, a gap in the transport direction between dots corresponding to how many passes is generated, and the measured density is lowered overall.

  Also, when performing the multi-pass printing described above, even when the nozzle row is tilted, such as when the print head is mounted tilted, the dots are similarly recorded with a deviation from the normal position. Specifically, when the dot recorded in the first pass is used as a reference, the dot recorded in a further distant pass is recorded in a position separated in the scanning direction of the recording head. As a result, a gap in the scanning direction between the dots corresponding to how many passes is similarly generated, and the measured density is lowered as a whole.

  The present invention provides a recording method and a recording apparatus capable of recording a pattern that suppresses a change in density measured for a pattern even when the above-described shift in the recording position of dots occurs. For the purpose.

Therefore, in the present invention, the sub-scan that intersects the main scanning direction during a plurality of scans in the main scanning direction of the recording medium of the recording head in which a plurality of recording elements for forming dots on the recording medium are arranged. by performing the conveyance of the recording medium in a direction, a recording method for recording a pattern for detecting the recording density on the recording medium, said pattern, the recording head N (N is an integer of 3 or more ) Recording is performed using different recording elements for each scan, dots adjacent in the sub-scanning direction are recorded by the same scan, and dots adjacent in the main scanning direction are the same scan or two consecutive scans in recorded characterized Rukoto.

Further, during a plurality of scans in the main scanning direction with respect to the recording medium of the recording head in which a plurality of recording elements for forming dots on the recording medium are arranged, the sub scanning direction intersecting the main scanning direction is by performing the conveyance of the recording medium, a recording apparatus for recording a pattern for detecting the recording density on the recording medium, said pattern, the recording head N (N is an integer of 3 or more) scans are recorded using different recording elements for each said sub-scanning direction to adjacent dots are recorded in the same scan, the main scan adjacent in the direction dot Ru are recorded in the same scan or successive two scans It is characterized by that.

  According to the above configuration, when recording a pattern, it is possible to suppress, for example, a density variation of the recorded pattern due to a change in the conveyance state of the recording apparatus and the influence of the mounting accuracy of the recording head. As a result, a pattern that reflects the recording density characteristics of the recording head can be recorded more accurately.

1 is a perspective view showing an ink jet printer according to an embodiment of a recording apparatus to which the present invention is applied. It is a figure which shows typically the nozzle arrangement of the recording head used with the printer of the said embodiment. FIG. 2 is a block diagram illustrating mainly hardware and software configurations of a personal computer that functions as a host device that supplies recording data to the printer illustrated in FIG. 1. FIG. 4 is a block diagram for explaining main data processing steps in the PC 100 and the printer 104 when recording is performed by the printer 104 in the configuration shown in FIG. 3. FIG. 3 is a diagram schematically illustrating a pattern for measuring an ink discharge amount of the recording head according to the first embodiment of the present invention. (A) is a diagram showing how to record one patch in the recording density measurement pattern of the present embodiment shown in FIG. 5, showing the arrangement of dots recorded in each scan of the recording head, (b) (E) is a figure which shows the change of dot arrangement | positioning. (A) is a figure which shows the dot arrangement | positioning by a prior art example for a comparison, (b) and (c) are respectively when the conveyance amount becomes larger than prescription | regulation and when a nozzle row inclines ( It is a figure which shows how the dot arrangement shown to a) changes. (A)-(d) is a figure explaining the dot recording in the state in which the recording head was attached to the recording device at an ideal specified angle. (A)-(d) is a figure explaining the dot recording in the state attached with the recording head inclined. FIG. 5 is a diagram for explaining a mask in particular in multi-pass printing for printing a patch with a dot arrangement according to an embodiment of the present invention. It is a figure which shows the mask pattern used when printing the discharge amount rank measurement pattern of embodiment. It is a figure which shows the relationship between the discharge amount rank and colorimetric value of embodiment. It is a figure which shows the relationship between the colorimetric value and ink discharge amount of embodiment. (A) And (b) is a figure which shows the EEPROM map of the recording head of embodiment. FIG. 2 is a block diagram illustrating a configuration of image processing by a printer driver according to an embodiment. It is a conceptual diagram of the database file structure applied in embodiment. It is a figure which shows the gradation correction table and head calibration table of embodiment. It is a conceptual diagram of the structure of the head calibration table applied in embodiment.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a perspective view showing an ink jet printer according to an embodiment of a recording apparatus to which the present invention is applied. In FIG. 1, a recording head (not shown) and an ink tank H1900 are detachably mounted on a carriage M4000. The carriage M4000 is supported by a guide shaft M4020 and a guide rail M1011. Accordingly, the carriage M4000 can be moved along the guide shaft M4020 and the like by a carriage driving mechanism such as a drive motor (not shown), a pulley M4042, and a belt M4041. Then, scanning by the recording head can be performed by the movement of the carriage.

  In this embodiment, cyan (C), light cyan (LC), magenta (M), light magenta (LM), yellow (Y), red (R), green (G), first black (PBk), second Recording is performed with 10 color inks of black (MBk) and gray (GY). For this purpose, a recording head that discharges these 10 colors of ink is used. In addition, each ink tank H1900 that stores these ten colors of ink is used.

  A plurality of driven pinch rollers M3070 are provided in contact with the transport roller M3060. The pinch roller M3070 is urged by a pinch roller spring (not shown) to be brought into pressure contact with the conveyance roller M3060, thereby generating a conveyance force for the recording medium. A paper guide flapper M3030 and a platen M3040 for guiding the recording medium are disposed at the entrance where the recording medium is conveyed.

  By the above-described scanning of the recording head and conveyance of the recording medium, it is possible to perform so-called multi-pass recording method recording described later.

  A recording head cleaning section is provided at one end of the carriage movement range. The cleaning unit includes a pump M5000, a cap (not shown) for suppressing the drying of the recording head H1001, a blade (not shown) for cleaning the discharge port forming surface of the recording head H1001, and the like. The paper feeding unit that feeds the recording medium to the recording unit by scanning the recording head includes a pressure plate M2010 on which the recording medium is stacked, a paper feeding roller (not shown) that feeds the recording medium one by one. Yes.

  FIG. 2 is a diagram schematically showing the nozzle arrangement of the recording head described above. As shown in the figure, the recording head of the present embodiment is composed of a first recording element substrate H1100 and a second recording element substrate H1101. C, LC, M, LM, Y, R, G, PBk, MBk, GY each ink color nozzle row is composed of two rows, an even (even) row and an odd (odd) row. Each nozzle row is composed of 384 nozzles (recording elements) arranged at an interval of 600 dpi. The even row and odd row are shifted by a half pitch of 600 dpi in the sub-scanning direction, and as a result, 768 nozzles are arranged at a pitch of 1200 dpi for each color in the combination of the even row and odd row. The nozzle row is equivalent to That is, each of the two nozzle rows constitutes a recording head of each ink color. Further, in this embodiment, nozzle rows for five colors are formed by one printing element substrate, and two printing element substrates are provided to form a nozzle row for ten colors in total.

  FIG. 3 is a block diagram showing mainly hardware and software configurations of a personal computer (hereinafter also simply referred to as a PC) functioning as a host device that supplies recording data to the printer shown in FIG. . In FIG. 3, a PC 100 that is a host computer operates software such as an application software 101, a printer driver 103, and a monitor driver 105 by an operating system (OS) 102. The application software 101 performs processing related to a word processor, spreadsheet, internet browser, and the like. The monitor driver 105 executes processing such as creating image data to be displayed on the monitor 106.

  The printer driver 103 draws various drawing command groups (image drawing command, text drawing command, graphics drawing command, etc.) issued from the application software 101 to the OS 102, and finally outputs binary image data used by the printer 104. Generate. Specifically, binary print data for each of a plurality of ink colors used in the printer 104 is generated by executing image processing described later with reference to FIG. Moreover, the process demonstrated by each embodiment mentioned later is performed.

  The host computer 100 includes a CPU 108, a hard disk (HD) 107, a RAM 109, a ROM 110, and the like as various hardware for operating the above software. That is, the CPU 108 executes the process according to the software program stored in the hard disk 107 or the ROM 110, and the RAM 109 is used as a work area when the process is executed.

  The printer 104 according to the present embodiment is a so-called serial printer that performs recording by scanning a recording medium that ejects ink with respect to a recording medium and ejecting ink during that time. As described above, the recording head is prepared corresponding to each of the 10 color inks of C, LC, M, LM, Y, R, G, PBk, MBk, and GY, and when these are mounted on the carriage, A recording medium such as a recording sheet can be scanned. Each recording head has an ejection port (nozzle) arrangement density of 1200 dpi, and ejects 3.0 picoliter of ink droplets from each ejection port. Further, the number of ejection ports of each recording head is 768.

  The printer 104 is a recording device that can execute multi-pass recording. For this purpose, a mask described in each embodiment described later is stored in a predetermined memory, and at the time of printing, binary divided image data is generated using a mask determined for each scanning and ink color. I do.

  FIG. 4 is a block diagram for explaining main data processing steps in the PC 100 and the printer 104 when recording is performed by the printer 104 in the configuration shown in FIG. As described above, the ink jet printer 104 according to the present embodiment performs recording with 10 colors of inks of C, LC, M, LM, Y, R, G, PBk, MBk, and GY. A recording head J0010 for discharging the ink. A user can create recording data to be recorded by the printer 104 via the application 101 of the host PC 100. When recording, the image data created by the application 101 is transferred to the printer driver 103.

  As the processing, the printer driver 103 executes a pre-stage process J0002, a post-stage process J0003, a γ correction J0004, a binarization process J0005, and a print data creation J0006. In the pre-stage process J0002, color gamut conversion is performed to convert the color gamut of the display device that displays the screen by the application into the color gamut of the printer 104. Specifically, image data R, G, and B in which R, G, and B are each expressed by 8 bits are converted into 8-bit data R, G, and B in the printer color gamut by a three-dimensional LUT. Next, in post-processing J0003, the color that reproduces the converted color gamut is separated into ink colors. Specifically, 8-bit data C, LC, M, LM, Y, R, corresponding to the combination of inks for reproducing the colors represented by the 8-bit data R, G, B obtained in the pre-processing J0002 Processing for obtaining G, PBk, MBk, and GY is performed. In γ correction J0004, γ correction is performed for each of C, LC, M, LM, Y, R, G, PBk, MBk, and GY data obtained by color separation. Specifically, the conversion is such that 8-bit data C, LC, M, LM, Y, R, G, PBk, MBk, and GY obtained by color separation are linearly associated with the gradation characteristics of the printer. I do. Next, in the binarization process J0005, the 8-bit data C, LC, M, LM, Y, R, G, PBk, MBk, and GY that have been γ-corrected are converted into 1-bit data C, LC, M, LM, Y, respectively. , R, G, PBk, MBk, and GY are converted into quantization processing. Finally, in the recording data creation process J0006, recording data is created by attaching recording control data or the like to binary recording data containing binary 1-bit data C, M, K, and Y. Here, the binary recording data includes dot recording data indicating dot recording and dot non-recording data indicating non-recording of dots. The recording control data includes “recording medium information”, “recording quality information”, and “other control information” such as a paper feeding method. The recording data generated as described above is supplied to the printer 104.

  On the other hand, the printer 104 performs a mask data conversion process J0008 on the binary recording data included in the input recording data. In the mask data conversion process J0008, an AND process is applied to the input binary image data using a mask pattern which is stored in advance in a predetermined memory of the printer and described in each embodiment described later. As a result, binary divided image data used in each scan in multipass printing is generated, and the timing at which ink is actually ejected is determined. The binary divided recording data includes dot recording data and dot non-recording data.

  Several embodiments relating to the structure for determining the recording density characteristics by the printer described above by recording a pattern and measuring the density of the pattern will be described below.

(First embodiment)
FIG. 5 is a diagram schematically showing a pattern for measuring the ink discharge amount of the recording head according to the first embodiment of the present invention. The present embodiment relates to a configuration in which pattern formation is performed at the time of manufacturing a print head, and the discharge amount rank of the print head is set based on the density measurement result of the pattern.

  As shown in FIG. 5, the ink discharge amount measurement pattern of the present embodiment is composed of four patches. That is, four patches are recorded for two ink colors, and two of these patches are recorded using a light cyan (LC) nozzle array in which the nozzle array is provided on the recording element substrate H1100. One of the two patches recorded by the LC nozzle array is recorded by the even nozzle array, and the other is recorded by the odd nozzle array. The remaining two patches are recorded using a green (G) nozzle array in which the nozzle array is provided on the recording element substrate H1101. Similarly, one of the two patches is recorded with the even nozzle array, and the other patch is recorded with the odd nozzle array.

  As described above, the pattern is recorded using the respective nozzle arrays formed on the two substrates H1100 and H1101 constituting the recording head. Thus, the discharge amount characteristic for each substrate on which a plurality of nozzle rows are integrally formed can be known by using a single ink color nozzle row. In the present embodiment, the Geven and Godd patches shown in FIG. 5 are recorded with the even nozzle row and odd nozzle row of the G nozzle row, respectively, as described above, but the ink used is a specific color LC ink. Is used. That is, at the time of pattern recording in the recording head manufacturing process, a pattern is recorded by mounting a light cyan ink tank on a portion of the printer shown in FIG. Therefore, the four patches shown in FIG. 5 are all light cyan patches. The reason why patches are recorded in light cyan in this way is that the color of light cyan has a sufficient dynamic range for the color of the patch with respect to the difference in ejection amount. Therefore, any ink of a color that can appropriately detect the difference in recording density need not be limited to the light cyan color, and can be selected according to the ink system to be used. Further, by discharging light cyan ink from the green nozzle row, the colorimetric values of the four patches can be measured with the same index. However, it is not always necessary to match the colors of the patches.

  The recording of the above pattern is performed in the manufacturing process by mounting the manufactured recording head on a test printer capable of recording by mounting the recording head. The printer and the host device that supplies the pattern recording data to the printer can be the ones described with reference to FIGS.

  FIG. 6A is a diagram showing how one patch is recorded in the recording density measurement pattern of the present embodiment shown in FIG. 5, and shows a dot arrangement recorded in each scan of the recording head. 6 (b) and 6 (c) show how the dot arrangement shown in FIG. 6 (a) changes when the transport amount becomes larger than specified and when the nozzle row is inclined. FIG.

  The patch shown in FIG. 6A is recorded by an 8-pass multi-pass recording method. In other words, the scanning of the recording head and the conveyance of the recording medium are alternately repeated, and in this case, the dots corresponding to the different nozzles are scanned 8 times (generally N times; N ≧ 3) in the scanning area where the patch is to be recorded. Record. In FIG. 6A, each circle with a number represents a dot, and the number in the circle indicates the number of scans (passes) in which the scan for recording the dots is performed.

  As shown in FIG. 6A, the dot arrangement is such that dots adjacent in the main scanning direction (horizontal direction in the figure; scanning direction of the recording head) are recorded by the same scanning or two consecutive scannings. . This is to reduce the deviation of the dot position even when recording is performed in a state where the nozzle row is tilted from the specified position. Similarly, as shown in FIG. 6A, the dot arrangement is such that dots adjacent in the sub-scanning direction (vertical direction in the figure; the conveyance direction of the recording medium) are recorded by the same scanning. This is to reduce the deviation of the dot position even when the conveyance amount of the recording medium is deviated from the specified amount.

  FIG. 7A is a diagram showing a dot arrangement according to a conventional example for comparison. 7 (b) and 7 (c) show how the dot arrangement shown in FIG. 7 (a) changes when the transport amount becomes larger than specified and when the nozzle row is inclined. FIG. As shown in these drawings, in the dot arrangement of the conventional example shown in FIG. 7A, the number of scans for recording dots is randomly determined. In this case, when the mounting state of the recording head is changed and the nozzle row is tilted from the specified position, the dot position is relatively largely shifted from the specified position as shown in FIG.

  8A to 8D are diagrams illustrating dot recording in a state where the recording head is attached to the recording apparatus at an ideal specified angle. On the other hand, FIGS. 9A to 9D are diagrams for explaining dot recording in a state where the recording head is mounted in an inclined state. In these drawings, as an example, a recording head of 16 nozzles is used for four passes (scanning), and each dot is placed at each of four dot positions indicated by light circles in FIG. This shows a case where recording is performed with the path indicated by the number. As shown in FIGS. 8A to 8D, if the angle of the nozzle row is ideal, even if the four-nozzle conveyance is repeated and printing is performed for each scan, as shown in FIG. All dots can be recorded at the specified positions. However, as shown in FIGS. 9A to 9D, when recording is performed in a state where the nozzle row is tilted from the specified position, the more the pass is separated, the greater the distance between the passes, based on the dots recorded in the first pass. Recording is performed with deviation from the ideal dot position in the main scanning direction. That is, in the patch that should be recorded with the dot arrangement as shown in FIG. 7A, the dots recorded in the pass farther from the pass for recording the dot recorded in the first pass are in the main scanning direction. Are recorded at a position distant from each other. As a result, as shown in FIG. 7C, blank portions where dots do not exist increase and the entire patch is thinner than the original, that is, the density is measured low. As a result, the density measured for the patch does not accurately reflect the discharge amount of the nozzle, that is, the size of the dot, and the discharge amount characteristic (recording density characteristic) of the recording head cannot be accurately known. . Such a tilt of the recording head can occur due to various factors such as an error in mounting accuracy, a manufacturing variation of the recording head, and a manufacturing variation of the recording apparatus.

  In contrast, the dot arrangement of the present embodiment makes it difficult to form a gap between dots as shown in FIG. As described above, this is because the recording position in the main scanning direction is more greatly shifted as the set of dots is recorded in a more distant pass (scanning), but the dot arrangement of the present embodiment is the dot arrangement of adjacent dots in the main scanning direction. This is because the set prevents the adjacent dots from being recorded in a further separated pass. For example, in FIG. 6A, the set of dot d1 and dot d2 and the set of dot d4 and dot d5 are adjacent to each other in the main scanning direction, but these are the same scans (first pass and 8 pass respectively). Eyes). A pair of dots d2 and d3 and a pair of dots d5 and d6 are also adjacent to each other in the main scanning direction, and these are recorded by two consecutive scans.

  Further, when a patch is printed with a random dot arrangement as in the conventional example shown in FIG. 7A, if the transport amount of the recording medium deviates from the specified amount, each scan is performed as shown in FIG. 7B. There is a gap between the recorded dots. FIG. 7B shows a case where the carry amount has deviated more than the standard, and when the dot recorded in the first pass is used as a reference, the dot recorded in a more distant pass deviates in the sub-scanning direction. Is recorded at the specified position. As a result, overlapping of dots occurs, and blank portions where dots do not exist increase and the entire patch becomes thinner than originally intended. As a result, also in this case, the density measured for the patch does not accurately reflect the ejection amount of the nozzle, that is, the size of the dot, and the ejection amount characteristic (recording density characteristic) of the recording head is accurately known. I can't. Such a change in the conveyance amount may occur due to various factors such as manufacturing variations of the recording apparatus, changes with time of the recording apparatus, the influence of the environment of the recording apparatus, and the influence of repeated conveyance.

  On the other hand, as shown in FIG. 6B, the dot arrangement when recording the patch of the present embodiment makes it difficult to form a gap between the dots even if the carry amount changes. This is because the landing position in the sub-scanning direction shifts more greatly as the set of dots is recorded in a more distant pass. However, according to the dot arrangement of this embodiment, the set of dots adjacent in the sub-scanning direction is recorded in the same pass. It is. For example, in FIG. 6A, the set of dot d1 and dot d7 and the set of dot d3 and dot d8 are adjacent to each other in the sub-scanning direction, but these are the same scans (first pass and second pass, respectively). Eye) is recorded.

  By the way, in the present embodiment, a patch for recording with the nozzles in the odd row and a patch for recording with the nozzles in the even row are prepared. This is because when there are a plurality of nozzle rows, the print position may be shifted in the main scanning direction between the nozzle rows. In the case of the present embodiment, when the recording position is shifted in the main scanning direction between the odd nozzle row and the even nozzle row, dots adjacent in the sub-scanning direction are recorded in a pass as shown in FIG. This is because it may become a dot. If the dots adjacent in the sub-scanning direction are recorded in a separated path, a gap is easily formed when the transport state is recorded as not ideal as described above.

  In the present embodiment, scanning in the main scanning direction for recording dots is performed only in either forward scanning or backward scanning. This is because, when printing is performed by bidirectional scanning, if the positions of the recording dots in the forward path and the dots recorded in the backward path are shifted, dots adjacent in the main scanning direction are formed as shown in FIG. It is easy to overlap, and it becomes easy to make a gap.

  In addition, in this embodiment, the number of dots recorded in each pass is not biased. This is because if the number of dots recorded in a specific pass is large or small, the nozzle used for recording the patch is biased, and the average discharge amount of the entire nozzle cannot be measured. That is, as will be apparent from the mask shown in FIG. 10 to be described later, when printing a predetermined area of a patch, the first group of nozzles in the nozzle row is used twice in the first scan, and the same applies to each scan thereafter. The nozzle of the group to be used is used twice. As a result, each nozzle is used an equal number of times in four scans. The present invention includes cases other than the case where the number of dots printed in each pass or the number of times the nozzle is used is strictly equal. That is, the number of dots or the number of nozzles used may not be equal depending on the size and shape of the patch to be recorded. However, even in such a case, it is within the scope of the present invention to configure the dot arrangement or mask so as to be as equal as possible.

  FIG. 10 is a diagram for explaining a mask in particular in the multi-pass printing for printing the dot arrangement patch of the present embodiment described above. FIG. 10 shows an example in which the nozzle row is composed of 16 nozzles and printing is performed in four passes for the sake of simplicity. In the figure, the portion of the mask pattern indicated by “black” indicates a mask pixel that allows recording. In each of the four nozzle widths for completing patch recording, mask patterns P0002 (a) to P0002 (d) shown in FIG. 10 are used in the order of the first to fourth scans. Specifically, as is apparent when referring to the dot arrangement of the present embodiment shown in FIG. 6A, in the first pass (first scan), the entire pixels at both ends of a predetermined region where the patch is formed. It is assumed that the mask has a printable pixel arrangement in which dots are printed. Thereafter, a mask print permitting pixel arrangement is formed such that dots are printed such that the entire inner pixels are formed in the second pass, and the entire inner pixels are formed in the third pass. By using the above mask, dots adjacent in the main scanning direction can be recorded by the same scanning or scanning in which the order is continuous, and dots adjacent in the sub-scanning direction can be recorded by the same scanning. Is possible. When performing 8-pass printing using a nozzle array of 768 nozzles as in this embodiment, a mask pattern as shown in FIG. 11 can be used. That is, in FIG. 11, in the mask pattern divided into eight, the pattern indicated by “vertical line” indicates the mask pixel that allows printing. Specifically, a plurality of mask patterns as shown in FIG. 10 corresponding to the first to eighth nozzle groups are arranged in the main scanning direction. By using such a mask pattern, dots adjacent in the main scanning direction can be recorded by the same scanning or scanning before and after that. Further, dots adjacent in the sub-scanning direction can be recorded by the same scanning.

  The density of the discharge amount measurement pattern recorded as described above is measured using a measuring device. A high-precision spectrocolorimeter is preferably used for the measuring device, but a reflection density measuring machine or a simple optical sensor may be used as long as the accuracy required for ranking can be obtained. In the present embodiment, measurement is performed using a spectrocolorimeter. Specifically, first, colorimetric values for four patches of the pattern shown in FIG. 5 are obtained. Next, the colorimetric values of the LC and G odd nozzle arrays and the even nozzle array patches are averaged to calculate representative colorimetric values for the LC and G, respectively.

Next, by comparing with the colorimetric value range for each rank of the ink discharge amount shown in FIG. 12, it is checked which rank each color nozzle row (recording head) belongs to. Note that the ink discharge amount rank and colorimetric values shown in FIG. 12 are used to classify the ink discharge amounts into five ranks based on the relationship between the color measurement results shown in FIG. 13 and the ink discharge amounts obtained in advance. The delimiter is determined. In this embodiment, c ^* obtained from the CIELab value is defined and used as a colorimetric value (c ^* = √a ^{* ^ 2} + b ^{* ^ 2} ). Any value can be used as long as the value is obtained.

  When the rank is determined, the ejection amount rank is written in the EEPROM memory attached to the recording head. Specifically, writing of the discharge amount rank obtained for each of the two substrates H1100 and H1101 constituting the recording head is performed. FIG. 14A is a diagram showing a memory map of the EEPROM attached to the recording head in this embodiment, and FIG. 14B is a diagram showing a specific example of the value. As shown in FIG. 14A, the EEPROM is mapped with 1 word = 16 bits wide, and the data length is variably assigned depending on the type of information. The head identification information 201 is 32-bit (2 words) long data, and information that can be expressed by the data length is stored as information unique to each recording head. In the example shown in FIG. 14B, head specific identification information “0FFFFFFFFh” (h indicates a hexadecimal number) is stored in the EEPROM. Reference numeral 202 denotes discharge amount rank information for each color, which is 8-bit data. The discharge amount rank is stored in five levels: -2 (FEh), -1 (FFh), 0 (00h), +1 (01h), and +2 (02h). In this embodiment, the rank is divided into five ranks, but the number of ranks is not limited to this, and may be divided into any rank. In the present embodiment, patches are formed from two printing element substrates with representative colors, respectively, and the nozzle array on the same printing element substrate has a relatively small variation in the discharge amount rank. For this reason, the discharge amount rank obtained for the representative color patch is also set for the color belonging to the same recording tissue plate, but each color patch can be recorded and measured to set the rank independently for each color. good.

  The recording head in which the discharge amount rank is written in the head manufacturing process as described above is mounted on the recording apparatus under the user, and by performing correction according to the discharge amount rank in the apparatus, An appropriate discharge amount according to the discharge amount rank is possible.

  In the present embodiment, the printer driver 103 of the host apparatus 100 shown in FIG. 3 sets a gradation correction table corresponding to the discharge amount rank, and performs gradation correction. FIG. 15 is a block diagram showing a configuration of image processing by the printer driver described with reference to FIGS. 3 and 4. In particular, the image processing is shown by various software modules. As shown in FIG. 15, the printer driver module main body C0001 acquires head discharge amount rank information C0002 from the printer, and acquires a database file name from a function C0003 that returns a database file name used by the printer driver. Then, color correction / color conversion processing is performed by the module C0005 using the database file C0004. Further, the module C0006 causes the gradation correction process and the quantization process to be described in detail below based on the ejection amount rank information C0002 of the recording head. Then, the recording data obtained by the quantization process is transmitted to the printer.

  The structure of the database file C0004 of the present embodiment is one binary database file C0010 as shown in FIG. This database file includes UI information C0011 (support recording medium information, recording position information), recording mode information C0012 (image processing information corresponding to each recording mode), command and margin information C0013, which are model information. Further, it has an LUT (color correction table C0014, color conversion table C0015) necessary for color correction / color conversion, and a dither matrix C0016 required for quantization processing. Furthermore, it has an LUT (tone correction table) C0017 required for the tone correction processing and a simplified head calibration LUTC0018 based on this tone correction table. That is, the database file C0004 constitutes a table holding mechanism that holds a table such as a gradation correction table.

  The head calibration LUT is a gradation correction table adapted to the ejection amount rank of the recording head, and the head calibration table C0018 (gradation correction table C1007 or) is used according to the ejection amount rank. When the discharge amount rank is the center, the gradation correction table C0017 is used for gradation correction processing. In addition, the method of loading a table from the image processing module incorporates a method of searching from a database file using table type information (TAG) and a table ID, adding a table type, adding a table. -The configuration is easy to delete.

  The database file combines such various information into one file, and each file before the combination has a unique file name. For example, a file name such as “BOOt tΔΔΔ.tbl” is assigned to the gradation correction table, and “BOOt” means the gradation correction table (TAG = 4). “ΔΔΔ” means a table ID. That is, the image processing module can acquire the gradation correction table ID from the driver setting (recording mode information) passed from the driver, and can load the actual table from the TAG information and the table ID.

  In the present embodiment, the gradation correction table C0017 includes all the gradation correction tables 1, 2,... (C0019) that can be used in the printer. One of the gradation correction tables is configured by a table C0020 for each ink color (C, Lc, M, Lm, Y, K1, K2, R, G, Gray) as shown in FIG. . These gradation correction tables can be selected and set according to the recording mode. In other words, the gradation correction table corresponding to a certain recording mode contains correction data that can express a good gradation using a recording head whose ejection amount rank is the central rank in that recording mode. The correction is high.

  On the other hand, the head calibration table C0018 is created based on the gradation correction table C0017 corresponding to the central discharge amount rank, as will be described later with reference to FIG. 17, and is a simplified table. As shown in FIG. 18, these tables include a plurality of tables 1, 2,... (C0021) corresponding to each of the discharge amount ranks −2, −1, +1, and +2 other than the center for each gradation correction table. ) Is held. These tables can be selected and set according to the recording mode, like the gradation correction table. In addition, one of these tables is configured by a table C0022 for each ink color, similar to the gradation correction table.

  FIG. 17 is a diagram showing a gradation correction table for a certain ink color and head calibration tables for ranks +2 and −2, respectively, used in a certain recording mode. The dotted line in the graph is a gradation correction table in the case where the discharge amount rank is the center, the line located above the head correction table indicates the discharge amount rank-2, and the other line is the discharge amount rank + 2. The head calibration table is shown. As can be seen from this graph, when the discharge amount is small, the output value is increased with respect to the input value to correct the image density, and when the discharge amount is large, the input value is corrected. Correction is performed in the direction of decreasing the image density by decreasing the output value. The calibration table for each discharge amount rank is created so that the image density outputted from the head at the center of the discharge amount rank using the central gradation correction table is the same in all gradations.

(Second Embodiment)
The first embodiment relates to a mode for measuring the ink discharge amount of the recording head in the head production process, but the second embodiment of the present invention relates to a configuration in which the user can measure the ink discharge amount of the recording head. Is. The description of the same configuration as that of the first embodiment is omitted.

  In the present embodiment, recording of the ejection amount pattern is permitted only for a specific recording medium. That is, an execution command is provided so that the user can measure the ink discharge amount by an operation via the host PC or the front panel of the printer. When the recording device detects the execution command, the recording of the ink discharge amount measurement pattern is executed by the same recording method as in the first embodiment. However, in this embodiment, since it is necessary to specify the recording medium to be recorded, the type of the recording medium that can be used on the host PC, the front panel, the user manual or the like is shown and the user uses the recording medium. Let them record. When it is possible to support a plurality of recording media, the type of the recording medium is specified by providing a command that tells the recording apparatus what the recording medium the user uses.

  The recording medium on which the ink discharge amount measurement pattern recorded by the user's operation is recorded is set on the paper feed mechanism of the recording apparatus and conveyed to the scanning range of the recording head. Then, the optical sensor unit attached to the carriage is scanned with respect to each patch, and each density is optically detected. The optical sensor unit in this embodiment is composed of a light emitting unit using an LED emitting element and a light receiving unit using a phototransistor, and irradiates light from the light emitting unit to the opposing patch and receives the intensity of the reflected light. Detect in part.

  Then, the discharge amount rank is determined as described above according to the detected reflected light density. That is, the relationship between the detection value (A / D value) of the reflected light intensity of the obtained patch and the discharge amount rank is the same as the relationship between the colorimetric value and the discharge amount rank described in the first embodiment (FIG. 12). An A / D value and a discharge amount rank are obtained and created. Then, the discharge amount rank of each print head is determined according to the rank classification.

  The ejection amount rank obtained as described above is stored in the EEPROM of the recording head. The area of the EEPROM memory map of FIG. 14A shown in the first embodiment may be overwritten on the discharge amount rank previously written at the time of manufacturing the recording head. However, it is preferable that the storage area for user measurement is provided in the EEPROM separately from the area to be written during head production. Further, an EEPROM may be provided in the recording apparatus main body, and the user measurement result may be provided in the EEPROM on the main body side, or may be stored in the printer driver. When the discharge amount rank is written in the user measurement storage area separately from the discharge amount rank written at the time of manufacturing the recording head, the discharge amount rank written in the user measurement area is set when the recording data is generated. Reference may be made to appropriate calibration.

(Other embodiments)
In each of the above-described embodiments, the example in which the pattern for detecting the difference in the recording density caused by the ejection amount of the nozzle in the recording head has been described. However, the application of the present invention is not limited to such an example. Of course. For example, a pattern similar to the above is recorded for a recording head in which the size of dots recorded by a thermal transfer method or the like changes due to the characteristics of the thermal recording element, and the inclination of the thermal recording element array or the conveyance of the recording medium Recording density measurement may be performed while reducing the influence of the amount deviation.

100 Host device (PC)
103 Printer Driver 104 Printer 108 CPU
109 RAM
110 ROM
H1100, H1101 Recording element substrate J0008 Mask data conversion processing

Claims (6)

The recording medium in the sub-scanning direction intersecting the main scanning direction during a plurality of scans in the main scanning direction of the recording medium of the recording head in which a plurality of recording elements for forming dots on the recording medium are arranged by performing the conveying, a recording method for recording a pattern for detecting the recording density on the recording medium,
The pattern is recorded using a different recording element every N (N is an integer of 3 or more) scanning of the recording head, and dots adjacent in the sub-scanning direction are recorded by the same scanning, and the main scanning direction is recorded. recording method, comprising Rukoto adjacent dots are recorded in the same scan or two consecutive scans. The recording method according to claim 1 , wherein the pattern is recorded by only one of forward scanning and backward scanning among scanning of the recording head in the main scanning direction. The recording head can record a plurality of colors, and includes a plurality of recording element arrays corresponding to each color,
The pattern includes a pattern of the specific color recorded by the recording material of the specific color using a recording element array corresponding to a dot of a specific color among the plurality of recording element arrays, and a dot of a color other than the specific color. 3. The recording method according to claim 1, further comprising: a pattern of the specific color recorded by the recording material of the specific color using a recording element array corresponding to the recording element array. The recording method according to any one of claims 1 to 3, wherein the number of dots printed in each scan of the N times are equal. An acquisition method for acquiring information relating to the ejection amount of the recording head based on a result of measuring a pattern recorded using the recording method according to claim 1. The recording medium in the sub-scanning direction intersecting the main scanning direction during a plurality of scans in the main scanning direction of the recording medium of the recording head in which a plurality of recording elements for forming dots on the recording medium are arranged by performing the conveying, a recording apparatus for recording a pattern for detecting the recording density on the recording medium,
The pattern is recorded using a different recording element every N (N is an integer of 3 or more) scanning of the recording head, and dots adjacent in the sub-scanning direction are recorded by the same scanning, and the main scanning direction is recorded. recording apparatus adjacent dots, characterized in Rukoto recorded in the same scan or two consecutive scans.

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